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ANATOMICAL TECHNOLOGY

AS APPLIED TO

THE. DOMESTIC CAT:

AN INTRODUCTION

TO HUMAN, VETERINARY. AND COMPARATIVE ANATOMV
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In preparation by the same authors :

‘‘Microscopical Technology, as applied to the

domestic cat, the frog and the Meno-branchus.”

“Physiological Technology, the methods of pain-
less experimentation (callisection) upon the frog and

the domestic cat.”

NEW YORK AND CHICAGO:

A. S. BARNES AND COMPANY.
1882.

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ANATOMICAL TECHNOLOGY

AS APPLIED TO

THE DOMESTIC CAT:

AN INTRODUCTION

TO HUMAN, VETERINARY, AND COMPARATIVE ANATOMY.

WITH ILLUSTRATIONS.

BY

BURT G. WILDER, BS. M.D,

PRCFESSOR OF PHYSIOLOGY, COMPARATIVE ANATOMY, AND ZOOLOGY IN CORNELL UNIVERSITY, AND
OF PHYSIOLOGY IN THE MEDICAL SCHOOL OF MAINE, MEMBER OF THE AMERICAN
NEUROLOGICAL ASSOCIATION, FELLOW OF THE AMERICAN ASSOCIATION
FOR THE ADVANCEMENT OF SCIENCE, ETC.

AND

SIMON H. GAGE, BS,

ASSISTANT PROFESSOR OF PHYSIOLOGY AND LECTURER ON MICROSCOPICAL TECHNOLOGY IN
CORNELL UNIVERSITY, FELLOW OF THE AMERICAN ASSOCIATION FOR THE
ADVANCEMENT OF SCIENCE, ETC.

aS

|

NEW YORK AND CHICAGO:

A. S. BARNES AND COMPANY.
1882.

re 2

“Copyright, 1882, by A, s Seven & Co.

ALL RIGHTS RESERVED.

| ly

PREPAC E.

TuHIs work has grown out of our needs as instructors of students pre-
paring for practical work in Human, Veterinary, or Comparative Anatomy.
Most of it has been employed in the anatomical laboratory of Cornell Uni-
versity for from one to four years, and we have been led to believe that it
may prove useful elsewhere. |

Some of our laboratory students aim to be professional naturalists, agri-
culturists, or veterinarians, but most of them mtend to study Medicine or to
teach Physiology with other branches in schools and colleges. The latter
desire to gain a personal acquaintance with the organs whose functions they
are to discuss, and the former require, in addition, a familiarity with
anatomical methods and literature; few of them have had any practical
training in Biology.

The guides to vertebrate dissection by Straus-Durckheim, Morrell, Rol-
leston, Krause, Huxley and Martin, Foster and Langley, Bernard, Martin
and Moale, and Mojsisovics, present many admirable features, but four of
them are in French or German, and none have fully answered our require-
ments.

Of the works above named, several imply that either the frog or the
human body has been previously dissected ; hence, presumably, the brevity
of the directions, the lack of descriptions of instruments and methods, and
the fewness or absence of illustrations. They are based upon the frog,
turtle, dog, rat or rabbit, or on animals in general, and the ordinary anthro-
potomical terms of description, upper, lower, etc., are almost uniformly
employed. Some dwell only upon points of physiological importance, and
in nearly all the references to other publications are few and general.

iv PREFACE.

So far as we are aware, this work differs from the manuals above men-
tioned in one or more of the following particulars :—

It assumes no previous anatomical knowledge or experience, yet is rapidly
progressive, introducing in succession bones, muscles, viscera, vessels, nerves,
brain and organs of sense.

It is based upon the domestic cat (see § 124). The terms of description
and designation apply to all vertebrates (§ 38); they are technical (§ 29),
and precision and brevity have been especially regarded in their selection.

The purely descriptive portions are subordinated to the practical and
directive. There is a General List of the instruments and materials
required for ordinary anatomical work (§ 130), and directions are given
for their care. All directions for dissection and manipulation begin with
special lists of the instruments and materials required (§ 235). Explicit
instructions are given for coarse injections, for the preparation of bones, and
for the use of alcohol as a preservative.

Certain regions and organs are quite fully discussed, while others are
briefly mentioned or omitted altogether (§ 128). Unusual space is given to
the viscera (§ 129). The study of the brain includes a consideration of the
typical vertebrate brain, descriptions and dissections of the brains of the
frog and the Menobranchus, and an approximately complete Descriptive
List of the encephalic parts, with References and Synonyms.

There are illustrations, and the methods of making the preparations
figured are fully described. The abbreviations are of the technical names
only, and they are nearly uniform throughout. As far as possible, the
technical names are written in full upon the figures. In the explanations
of the figures, the technical names and the abbreviations.are alphabetically
arranged (§33).

There are numerous Alphabetical Lists, Tables of Synonyms and Tabular
Arrangements of names according to the relations of parts (p. xxvi).

Attention is called to the incompleteness of our information upon cer-
tain points.

There are frequent cross references and numerous definite references to
other publications (§ 2); the titles of the works and papers cited (three hun-

PREFACEH. Vv

dred and thirty in number) are given in an Alphabetical List of Authors
at the end.

While, therefore, the book is designed primarily as a guide for beginners,
certain features—the references and the suggestions as to lines of inquiry—
may prove useful to teachers and others who may undertake to add to
existing knowledge.

Histological facts and methods do not come within the scope of the work,
but at the close of the discussion of most of the organs is given a summary
of (A) the obvious or macroscopic structure—that which may be determined
with the unaided eye, and (B) the fine or microscopic structure. The latter
is in no sense complete. It embraces only the points upon which most
standard authors are agreed and which may be demonstrated without a
great expenditure of time. Only the structure of the given tissue is con-
sidered ; hence the presence of vessels and nerves is not mentioned. If it
be desired to carry the histological mquiry farther, the works of Quain,
Stricker, Ranvier, Beale, Frey, and the special papers therein, referred to, are
recommended.

Among the many friends who have aided or encouraged us, our thanks
are especially due to Professor Oliver Wendell Holmes for helpful criticism
of the terminology and for suggesting the preparation of a manual in which
it should be incorporated ; to our colleague, Professor J. H. Comstock, and to
Professors E. C. Spitzka and T. B. Stowell for valuable suggestions and
for the adoption in their writings of the descriptive terms herein employed ;
also to the last named for a critical revision of the early manuscript of the
muscles, and for the important additions to knowledge contained in his
recent paper on the vagus nerve of the cat. To all of our laboratory stu-
dents we are indebted for aid, suggestions and criticisms, and especially to
those (see end of Bibliography) who have selected parts of the cat as subjects
of their graduation theses.

Our acknowledgments are here made to the American Philosophical
Society for the use of the four lithographic plates, and to the firms named.
in the List of Illustrations for the courteous loan of electrotypes of instru-
ments manufactured by them.

The original figures were drawn by the persons named in the Note pre-
ceding the List of Illustrations. The three ladies have also been our stu-

vi PREFACE.

dents, and have shown more than ordinary interest in their work. Most of
the original drawings were made by our colleague, Professor E, C. Cleaves,
whose skill, patience, and accuracy only artists and anatomists can fully
appreciate.

There has been constant codperation throughout, but, it may be proper
to state, the senior author holds himself particularly responsible for the
Introduction, the Preservation of Soft Parts, the Bones of the Limbs, the
Muscles, the Heart, the Central Nervous System and the Cranial Nerves;
and the junior author for the Preparation of Bones, Coarse Injections, the
Skeleton excepting the limbs, the Viscera, the Peripheral Vascular and Ner-
vous Systems and the Organs of Sense.

Notwithstanding our efforts for accuracy, there are doubtless errors of
observation and interpretation. Corrections or suggestions will be gladly
received.

-
Vit
—
C-O;R OTE N: E's.
INTRODUCTION

PAGE
References to Publications.........-..-s.+++++ wie batts? lume ug pe teee Ale aieles 1-3
Method of reference to authors. .......... ccs c cece reece cece enncerece 2
Catalogue of scientific papers published by the Royal Society of London .. 3
Decimal Systems: os... 0055 505 vniey tins sone scvesiee wi sielee beeen s omsing sacbaweedes 3-8
Centigrade Thermometer—Fahrenheit’s Thermometer... 1... .0eeeeseveceeeeees 3
Comparison and reduction of the two thermometric seales................ 3

Table of equivalent temperatures according to the Fahrenheit and Centi-
gerade thermometers 6. 45s asa 3s wea hn se As amie, 214 Fa ae hens aie 5. 4

Formule for the reduction of the Fahrenheit and Centigrade scales and vice
ee PEE Oe Pe Te Pee Oe Ot EEN eer CN PY EE: oF
RE MARNE EON a Sat dee en phas. «0 62.0 Paid Kaede kas « COR aca neys Oe OER 4-8
Meter, liter and gram—definitions and common equivalents.............. 4
Comparison of the metric and English systems of weights and measures... 5
Table Of the Metrie-mGeQUaree 5 6515 hina sacs w«r pss eins Mena nid Bp one vaeey ain. s 5
How to learn the metric system..........0 Desc cevecesecccsncccececceedes 6
Table of equivalents of metric and English measures. ...............0+-5- e
The metric system in medicine, .... 0.0.02 ccc cece es cence scesccens 8
moologicel Claanifcation sae < aids daa Pls ape aah s wnieneon Ks mote nidveae Sepals 8
Table Hiustrating. claseifieation ~ 7:7 O020) Ge ke dS Ss ew te cedeaeias 9
ERENT Nina's 82.5, = swint anaeine Rain a os’a net kita Muah we Stan Ra ain. tgre ss Bik o-nck os 10
Character of the terminology here used... ........2. ceeeeeeeecceeeeeees 10
General considerations upon anatomical terminology...............++.++- 11
Aphorisms upon terminology from various sources .............+-22:e0+> 12

Brief statement of the objects and methods of the terminological changes
TGP IED 6 Ln ore ae DEC cae aad aha dab ciate Sub ele w Lk AS Bsn ZA ge 9 Ts 13
Designation of Orgauns—Organonomy ....... 2. cece ccc ecce eee cee seceewereene 14
General considerations by various authors... ..........-..2eeeeeee eee eee 14
Suaporcaner OF WEOViby con ues an wile SCE I canes acd cheb eee otaen e's 15
Comparison of technical and vernacular terms BEE SOLEMCO NS cig le viola, oe elas 2» 15-17
Fase in acquiring technical terme: soc. 558 665 esi sitters y censceesccnsees 17
Names indicative of relative position............0..eeeeeeeeeceeccneeess 17
The limits of terminological change. .............-20ceeees cesses eeceses dS
Priority and etymological appropriateness of technical terms........-..-- 18
Some inconsistencies in the nomenclature here adopted..........++.+++.- 19

Names and abbreviations on the figures .........00.cceeeeeeeee cer eees 20

Vili CONTENTS.

PAGE
Terms of Position and Direction—Toponomy ......00.--eeeeerecceeeeccceees 20
The normal position of the body... 2.2 ..ccccccscessececccnceccs Pegs 21
Designation of the aspects of animals. .........0....00scceseccceseececs 21
WiGWH OF SSGRGHNy MBC AIGUEES oh ooo 5 sa.0i6lap oo uasin's hens Coos Raw Rave eens e 21-22
PASUDTUIGY OF GOLTOR v5 50's 1c 3 cis ease See Wviks os € beige me pinipe ip pases ees &i'o'sd 22
ag i ae ea eee PPE Tee gery Pe eee Ee See pe a fi ee eee 23
Cephalic and caudal, dorsal, ventral, dextral, sinistral, lateral and mesal—
signification and use by various authors ..............222 0 eee eee eee 23-24
Ventrimeson, dorsimeson, intermediate and medial..................006- 25
‘Designation of the Regions of the Limbs......... 0 cccccesecscveceeeccccencees 25
POLL AUG CAAA OXLTOMICION, oie piccs's, assim = o> bap ting a aicion slays Sd cele Ae kis 25
Cephalic and caudal, dorsal and ventral aspects. ........6.-04---eeeeeeee 25-26
Other names for the extremities and aspects. ..........2..-02+2202 seuss 26
Terms of General Application to the Whole Body... ......000.00enceneccccnees 26
Central and peripheral, ectal and ental... 2... 0.65 c.ieeeesccsioescdeviees 26-27
BRIO LE cade Pans cid Taste is 6056 cursed Vane ee ebiccee iddGneee ct 27
Adjective endings.......... EMA COAL SE eee heehee. 27
Use of the prepositions of and from. ...... cccececccececcceccscecsesees 7
Haimitations OF ACCUTACY: iia cles scales Fok ses ss beets Deitaettn tas meee mone 7
Derivatives, connecting vowels Of. 50: . 8... os Se eae eee eee see ess 28
Compound words—Hybrid words. ............ 0c cee cece ce eee cece een eee 28
Primary Divisions of the Body—Soma and Membra...................-..00 29
Axial portion, soma—Appendicular portion, membra—Truncus or trunk.. 29
Comparison of right and left (dextral and areca in the object and the
IEE VOR oo. ors isn h a ack See Eas alee Tateie ei eeecle ne aie > oases owe 29-31
Position and direction onthe soma. 2.5 .6c cw is cases c cee c ees ascsees cess 31
Columna vertebralis, its constitution and location ....................-.. e
Canalis neuralis and ccelum or general body cavity...................... 33
Essential characteristic of all vertebrates. ................. cece eceeeeees 3e
MN Sr CORED, Ss sins Osean eae asd Pee Tae SOUS eae gee toe aie te sacs} oe 33-34
OT EO icin tarry oe wt ene’ Say crt Se re eee ae 33
Paired or Lateral Organs—Azygous or Mesal Organs ...... 0.0... c cece eee eee 33, 48
SPEeMPURtION Of -FORitiOn AN DiTPCtiODs-.% occas <00c¥onckses ccabecsavvatyeees 34
Ditect tines —Obliqne Nace sic sos 5 eases det akewecchbceens de> sees 24
Designation of direct and oblique lines. .......... 02... .0c eee eee ee eens 34-35
Designation of position on oblique and direct lines ..................44. 30
Designation of diagonal lines..................04. in aii atatiess Sis son ark eee 35
Designation of the relative position of points on diagonal lines............ 36
Designation of Direction and Relative Position on the Limbs........... ..00-- 36
Ental and ectal and their derivatives... .. AER GR eo NNn Pee re ee 36
The soma and its divisions—Head, neck, trunk and tail....... .......... 36
The trunk and its divisions—Thorax, abdomen and pelvis ..........+.-- 36-37
Partition between the abdomen and thorax.............2.-2-0e2 ee ee eee 37
RAR OU WRN ORVIRY CS cds 5 Aadveea maces 45.020 bok 4 oehing races Canal 37
LWIG-O8 4HO CiVImODS Of the body’). oie ccs 6 <5 seen ssaee ven scadbessheuss 39
Normal RIS EE MAE RENO DRI yin ks 5 oS £5 pA ies 10 ald Sie tis'b as nn doe SS SENG 37
Limb Segments and the Arthra or Joints...... 2... .cc ccc cccccccccccccucceece 40
REINS 9 555s SS kaleho lars Gb 4g oS 4d AO EN a O25 ns tee ature pasaien ssa ade 40

REMMI CAIN ess ca tue ciara ce rik LON TES a9 < Piclane ons oO a8 eOF PRE 41

CONTENTS. ix

PAGE
Frtecmembral Fromagerie 5558 sy PRINS CARS i ole Fels Bet ay wg Seeds 42
Byntropy and antiteopys oss is ccs n cee e tes cee eens bi adg tae are eid waceaes 42
Enumeration of Parts in a Series....... ..... PETE CLER TIVE Re ee 42
Use of Terms of Relative Position in a Physiological Sense................. 44
Blin Gretent Of Notes. feces ck 653 spas TOES SIRE Te LAE eaves segs 45-52
Slips—Size, etc.—Making notes on. .......... eee ceec ence eee e eee eeeeees 45
Library catalogues and catalogue data for specimens..................4. 46
References, extracts, clippings and notes proper.............. 0. .c cece ees 47
Accumulation and elimination of slips ............ 0... ccc cc ecc cece eeeee AY
Arrangement and storage of notes. ........ 6. ec cece cece ete e aceon ceeeees » 48
Subdivision of notes, with Table. ......... 0.6 ie cece cee Cepulee eles 48-49
Distribution of- Slips 5. cae vs sees cee eee lubae Ana oahgereetete rede BON Seen ke OCs 50
Mothod of asinot slipatlitos Joye clk FSA ors Hee Ne iT aoe tacteece saat ce ahs 50
Portfolios for slips: and Sheets o.oo ie olse.e. 5 oe ivi kW bier nal we’ eden wale el ovapelblevslare 48-51
Miscellaneous suggestions as to the use of slipS...........0. cece eee eee 51
Oricin-of the:slip «system s' sie oe see Ue ion te litle Melee PEE aeons 52
Rules and Aphorisms of General Application in Biology..................065 52-53
Anatomical Technology—Introductory............. cc csc ccc cseeeeenececcuns 55
Reasons for Selection of the Cat for Anatomical Study. .......c00cccceeeueeeee 55
Importance ofmothodas s2 2 se Seb OE rae Galea ee SUS CI ROE 55
Comparison of the cat-as an anatomical subject with adult human beings,
still-born children, horse, rabbit, dog, rat, opossum. ..........-.++-0 55-57
Needs of a standard of comparison for comparative anatomists............ 56
Reasons for treating of only a Part of the Body. .. 1.00. ccc ccc eeecneeeeeeeeees 57
Reusons for giving unusual Prominence to the Viscerd.......600.sceeevececees 58
CHAPTER TI.
INSTRUMENTS AND MATERIAL FOR ANATOMICAL TECHNOLOGY,
Alphabetical list of instruments and materials needed for anatomical technology,

BURN EOS ica a/v sks «als eataaw bkq The ty diate dean PUL ae PRE Ae tM NS aie Ree 59-62
Dealers’ catalogues of instruments and materials. ............-0-++ c+ tee eeeeees 59
General Characteriot Instinments yi 65 jc5 fv kie a sis sieve sin wv 5 ng es Tee Ras cina rare 62

Description of Instruments and Material. 0.1... cc cece cece cent eeee ne eeeeees 62-73

Arthrotome and beaded bristles. .........cc.eceesnrecneecereceseceesincs 62-68
Supporting blocks, flexible DLOMaPIPAs, rede aered a wrke Was Ben eae Werewie wine ee 2 64
Cats-=P rite; Are, StOrAgo COG. oe nos bi diac viccere ane. e0bn. bts ee sabe pam 64-65
Chain-hooks, small compressor and dissecting gown. .......++++ee++esee: 65
Drawing materials, foot lathe and drills, forcers (coarse and fine), nippers
PEPE UN 5 chad cs eRe ete nev Ned akbaee tneiinrer een 67
Dropping-bottle oiler, parchment labels, rubber gloves and tubing, saw... 68
Scales and special weighing pan, scalpels.............000eeeceeee eee eees 69
RPUASTRE ANG: BEVIN D OG are cs «.c hd ss od A Kee Niece MORN Gare Se ee vie aie 70
Syringotome, tags for labels, tools, towels, tracer (seeker or finder), sharp
BOO DUDS 1401s bataa SASae aco sie CRE RT ya eee VERES Hehe we 71

x. CONTENTS.

PAGE
Wetting bottle for 15 per cent. glycerin, waste paper for particles made
Ah IRNOCT asks eee eig ons caine eh 5.04 (has 2e3 eae dee 73
Cereot Instriments....<a.s s.,s<.ss 2e,scbescd ve been cena aE ee hele 73-74
Special directions for blow-pipe, tray, forceps, nippers, saw, scissors, scal-
rel, and cutting instruments generally...............-...... Saath 74
Cases. and Trays for Instruments... ¢.0cc. 0): tosses ip peabic-ss Grd e¥eléavces ee 74
Packing Instruments for Transportation. ......000cccceesccecccceecececces 75
Peushing Instruments. 1... <1. ich cise View ese SOE G Oa olde ORES NWS ey ees 75-76
~uarpening ‘lnstrumients.... .. .....55... 5 sso ls Mi sdeube ri eeW seh badaiesk aes 76-79
Honing snd BrOppin gy. 65.2 vii 2) 2n'biaj0,) slew lets a seas APE oie Sr rateiewiac b 76
Detarmination Of Bharpwess 5. -5.'5 5\<% 3-2 icic ls Was sdetstohe pie wiewh miata sheng blots ius 78
Milling Aninigis for Dissection... os. <0 \.s0ide's sess soe <3 es debe Vee pyeed euleld's 79-81
Drowning, killing with chloroform or ether in a box... ............+--- 80
Anesthetic box..........-.5+- waussle sie aioe ESS Weyer Bia) mb lame ioe ae ae pisle sie 81
Melting tease wath Benzine. . vis ls ik 0s Von is bina oa eons a mp ayeanabonents 80
Precautions for Cleanliness, Comfort and Health..............-.....200-0. - 81-86
Waste paper, waste pail and waste pit............0... cee cewee eee eeee 81-82
WY MBN WI Sak de ais Susie Sole « He eds NN vissvd be oe Daas. vdeo wt ReuERES 82
Deodorizers — Animal charcoal, alcohol, potassium permanganas, sul-
BUBGS OF IEDR, 5 p< lei teow ie OW clentale yee ie ele SAS bab Re Os eb Ey 83
Malodorous parts to be promptly removed............0.2..eeeeeeeeeee 84
Dissection Wounds—Precautions and Treatment...........ceeceeeeeeecees 85

CHAPTER II.

GENERAL DESCRIPTION OF THE SKELETON, ANATOMICAL LANDMARKS
AND ABDOMINAL TRANSECTION.

General Description of the Skeleton... fs. cece edo sw es cecsnaes 25 SBIFOb
Components Of the skoletom jos idl ye casio wie iw pg ome aS oe spn ores Biel ea Sie 87

Somatic or Azial Parts of the Sheeleton... 2.00.0 csecccsoseccessccesecs oss 87
Patt) MU VOXPGUTID, «ocd ent occa es te ces psp scacrAcceau’s bas ecvep a 89

Coste or ribs, sternum, scapula and clavicle.........-. .e.seeeeeeeeaess 90

Pelvis, Shoulder and Hip Joints, Wrist and Ankle...... ccc. cece e eee ceeeee 91
Membra or Appendicular Parts of the Skeleton. .... 2.2000 ccccceeeeceaeeee 91
PSOUE IT ILO MINUS co Pe see ban eine ses Pa eis we's smile a Coie clsiw's owne.s overs 91

Normal position of the limbs.............. PEs, na cere w eters Peete cele 92
Position of the arthra or joints in the limbs................020- eeeees 93

OB NVOIGES ONG TAL VUES oon sss cela ana ava vs%> ow elect eae s o's we nee si tia 94

MMR MMUCHE SRTMAINESEED. oa.55 ise a Poss esa ab iasie have vee mas S Tp ld oa Cow wed sons 95-98
Mesal Somatic Landmarks... .....ccccvcccvece coctereccssccscsceccgeeecs 95
Lateral Somatic Landmarks... 2... ccc cccc cee c cece veeseweccecssereseecens 96-97
Mombral LAnQamae ks o.oo oa occ sc veces ns ciccecccnccecctwcae sy seecnce secctees 97--98
MAGOMNING! “PERRSECHION s «5.05 4,000 0.0.05:3.5 000 npc'c sac satgescsecepedeey ee EPEC 98-102
POPUS MNVOLVOU fess ic icc oe veld cise bos os sts'n se maa avila ds b 4.6 ple 00. mo oyls 99
Preservation of the Cephalic Half of the Transected Body.... ..+.++++++0++: 101

Thoracic Transection....... oh dee Ube ages saves. wey mstie es cee Ved mins se ewan 102

.

CONTENTS. xi

CHAPTER III.

PREPARATION AND PRESERVATION OF ANATOMICAL SPECIMENS.

PAGE
Preparation of Bones... 0... ccc ceed cccecessrecccccsserseesenseccesesceste 103-111
Granaral Givecious hci sie ae Peed wisys sate eres ealen o/ed shold aaeeenen 103
Removing soft parts from alcoholic BPCCIMONA... eens seccedes bavboses 105
Removal of soft parts by ants or De: mestes..........0-6. 00 eee eee eee 105
Putrefactive-maceration in: water. ......56 6. ccc eee e cei w ese see cnens 105
Boiling in liquid: soapy... 0s .ses eee cesceecsecesies Germ bd th eat aR 106
Preparation Of Shull), ..wccecvcdvcdvcdan: decdededesaeeye sae aeeaieis cuban 107
Ooments for Bones Gnd. Teeth. .vescccccecedecccccsccsvececesssseccacccece 107
Preparation of Natwral. Skeletons... ...-ceceesce vecvccccccessereccsecece 108-109
Hlexiblo natural sk elotonsss co’. cd Se de-uie'sn we! <u ois eid d arele sd Clalsicte'e siateleie eee 109
Preparation of the Bones of Young Animals. .......0.cecccceecccceeeeenes 109
TI UMMA OMRED 52s 4) 0.00,5.0'< kos, h2 V4) RE RORE OK Lo ives ee Uae saains Be wEE eR 109
Bleaching Bones ...... ..... OE POTN Ee ee Be IO 110
PEGRRETatiNR OLSON Parte so deids cad ove cane Daeg ae. We esisb sae g were ea aves 111-131
Agents preventing decomposition. ...........-.cccescercccccenceecees lil
Ethyl Alcohol—Absolute and Commercial .....- 0.0200 ceceececcees ceccuees 112
Table of percentages of alcohol .....0:.06 05 cu cct es ceieeee seasseesesesa 112
Leading characteristics of alcohol......... Saihh at ahied, see facia tase Be Reales 113
Inflammability of alcohol and precautions against fire............-.+..- 114
Determination of percentages of alcohol with the alcojmeter........... 114
Determination of and changing the percentage of alcohol....... ......- 115
Table of the amount of alcohol and water to mix in order to obtain a
PORTOR DORCOIIAIG: heey dis seis wig KA vines 62 PE.’ Ae AMEA MESS ao hak oot 116
Kind of water to mix with alcohol........ Oar Seas cae ee 116
Uas'ot Alcohol in Preserving Animals. . 5.0... .is.cces ancigtn onde soa 0 hos e559 117-1381
DOO SHG -RIRUDAL 6 00 csherute a 2b ae headin in a 6 Ca a en tke eos tenes ober 117
Opening the abdomen and expelling the feeces...........--...00+20e00- 118
Injection of alcohol into the thorax and abdomen................-+2..- 118
Injection of alcohol into the lungs, stomach and intestines ............. 119
BA UPCUING GL BEY MNMION od a area v.04 gc ee Vv du dams chnialhcad tes margin’ apr 119
Treatment of Special Animals, Organs and Tissues ........ 0 0cee cece eee ees 120
Amount of Alcohol required for @ Specimen... ... ccc cercceccncceccceceens 121
ee UNMMTRE <E P UNDO OIEE 5 sie Santa stp 3s, a <9ie,% Gack 's ears pins Seniesa. winas tae 121
SIOPIOPRELON AE MORIN 5 Se ae a5: in eed Ke aia wa oe oD RES AeA Tbe ehcp bs 122
Purification of alcohol by settling and filtration............. ......45- 122
Alcohol Vapor as a Preservative............ pe araia te scala dahon c cng Sualel Sein Salen 123
Methyt Alcohal oF Wo0d Spirit aca ss: nl oisin, nh Ts wen Sina diesen iaasesacceves 124
Wickersheimer’s Preservative Fluid.............++- , aieptn Geico ka eel ai’ Kiace = 124
CRRIOE AE MMU TEE 5 Lee sad 90 5 Ad BA NE Sead sh CR ACD Lis: wis cio aco eam R88 124
PM eR otic es «das Ss enna eon Lenten ae dais eamaldiae.9 cia'Wed daet ae caw cet 125
Temporary Storage of Alcoholic Specimens. .........0.cecceccecceeecceeees 125
EBRUHO ADO CVADORAIOR oat. es cin'dbc cc taweris sadainav cece ce eeee ees 125
Glass dishes and boxes for specimens. ..........c0ceceeseseceeee cence 126
Exhibition or Permanent Storage of Alcoholic Specimens.......- 02.2000 seees 126
Pectal Cane, BCrOw-lpp CANA. os eis io sevieln at weet BW tele edee te wees 126

xii CONTENTS.

PAGE
ARO SOON, SS gs wnt 2D Fe Nein RETR SN oo olGe Os eae PRR MEME Ma ancy s 127
Glass-stoppered and welted viste mutecsteelds ahs koma e a eee hen ote Ribas nisi 128
A IANS ANTE Ce nase poo 9s Sipe 6 40s «RG OPED AN eS Ws webs * 128
Display of alcoholic specimens. ........-.+20sceeecseecsecsercs UE Peery: 129
Packing Alcoholic Specimens for Transportation. ...... 0.000 ecceeeeeeeccees 129-130
Proxen Sections and Dignectiona..« 3 <scsc.cniacacedobesinsip ecm RETA chs © «+. 131-132

Preparation of the animal for freezing—Making and preserving the
WO ash a nis js nis SR Rhea NERS RO Nd CUS A MARE NA Rae TEE an ened s 131
WPOBGR CIOOTOIN, '5,9:.(n 5. daa oasif with cle Chak VMS aE ROS Comings cede 182
Flexible preparation of muscles, . . .. 6.4 serie cine abeesssbesecccdseeoneas 132
Preparation Of FOUNGW, MISCOER 6 ise sedic creas cscs nes neeseuxe weak senslowh 132-135
RRONOMIN ION OR ENR WEIMAR 5 joa = pinks Sin asm ihn nie eh Bo 9G 4g Nels an dows . 132
Cleaning, trimming and inflation with alcohol .......... ....-.....00. 133
Poisoning, inflation with air and drying... ..........00cceeeeeeeeeeees 134
Preparation of the viscera after drying. ..............00eeeeseeeeeeeee 135
Measuring the Capacity or Volume of Organs..........2c cece eee eenceeeees 135

CHAPTER IV.
COARSE INJECTIONS.
ERNGOL TM MECOMOUNE ssw eset tha ccae eater cee Suse nspes er tees tesveuers cements 1387
Syringe—Care of syringe, white metal syringe...............eeeeeeeeeeee eens 137
Canule and preparation of glass canule............ 20sec ee ee ee eees 138
PIPAME RUGLONIIEN BYTINIUR. ¢ sve he wecese cba cues Wes cs vs ce sence nthe sean 189
PICCRION MAMGROS. So pe Sens c= cami bees Rows ere add WRCenhe 6 ces bees eee tees nt ies 139-141
FIGS OC Fes MOOD a cre cule aces oo vce ECR Toons e Ave tec ee apse eeneanete 139
Carmine, Berlin blue and various colors for staining plaster............ 139
Preparation of plaster injection Masses.......-.... cesses e cer ceccceeeee 140
WS GAG TAU PIOMNIR 5 hoa 5 caceikcls one Hs oslo k 6 Ub oN nw obaesscs bbe N ess sb 141
Practical working of wax and tallow injections. ..........-..++.+-.--- 141
Choice of Specimen and Time for Injection. ............ 20sec e cece eens eer eee 141
Station rid VERNE SS SEOUL. as oc. cons cee ase tases cctauy os ass ewes woe ce 142
Enjection Of Femoral V esas, oi ccc ica Seiden ecg enesios veescesevaccsccertes 142-146
Posture and Exposure. /......05. 5. Was e sled cies epee cece es een eccccencess 142
Parting the hair and isolating the vessels ... ........020+005 ++ seeee 143
Incision in the vessel—Ligatures and introduction of the canula........ 143-145
Making the injection—Tying the vessel... ....-...- 2 eee eee cece ese eeeee 145-146
Cleaning the syringe and canula.............ce cece er cece eect erences 146
Injection of the Abdominal Aorta and of the Postcavd........++eeeeeeeeeees 147
Injection of the Jugular Vein and the Carotid Artery.........600+2 ose eens 147-148
CHAPTER YV.
OSTEOLOGY, THE STUDY OF THE BONES.

Determination of Right and Left with Certain Bones.................-..+. 149-151
Position Of the Hones. o.0.50:0:05 vivcies vin eves ceiagn vieesees snes eee eerses 149

Determination of Right and Left with Entire Timds . 2.0... cece cece cece 151-152

CONTENTS. xiii

PAGE
Special Mnemonics of the Humerus... .....+005+ wo PRT ALAN Peder ted weak 152
EROBCTINGION OE TIOWON oa 6c) da one en Soph clon a Caen ke Ra REESE SOS 089776 HACIA EKESS 152-189
Scapula (shoulder blade)......... bean te RaearUTNe Ueigiceaesids Tees me o«++ 152-156
Humerus (bone of brachium or ‘‘ upper arm”), ...... cee e eee cece eee 157-161
GCarpalia (erin DOs) a0 oa f dw co's Hanya S05 ka de tiivg he pe Caialg agen et 161
Glavicula (clavicle:or collar’ Done). « ... 4.06. elssis/aiesie waste cians sles cans 162
Saemamme Chr]east! bone). aie es saa prspadns daids Gs iinioricdidedeed¥adshas vic 162
Costeo (rapa amt costal CATEH RFCS oo oink c's daoss sang es endas cue steen areas 163-167
Ligamentum interarticulare and Comparison with that of Man.......... ».++ 165, 166
Pn AA I CEE ORI bia basin Gensco cae, citieee os Eaotaeate ine eat 167-169
Tlium, ischium, Os cotyloideum, Os innominatum, Os pubis............ 168
BACRONY cass verte ates ccm siese siamese Pasha Oo sisiits bis Fetrecue mate a as Geaiens 169
Cadence WOrteOT ANG oa 35.6 25 85 5 UKE aA Raa blely 64 ais) Care 4,4 Hew as Saale? 169-173
Regions of the vertebral column..............s0nccccccccccecccsecece : 170
Distinguishing the groups of vertebra............. cece cece eee eeeeee 170
Me in, Vo ca kos cubes Was de SU es cds Bees Medio d Serldiad bye mien Mv omelensian’ 173-191
COAT RUT ANG: SAGO. :cc)0's 6 0 cgiare skoresdghtitn ee tsi dele y eel rein aluisigns Vaecantes Ae 174

Seb TOseiare Sasenisicie so utle tig sna essllaniecs, ci iornwin Se alga neue OS eh saga ee ate’ e 174
Table of the Bones Of the BHU: ... 0.5 0.0 cesvee Vice aieris wieele b.90:8 Saw egeree +++» 174-176
Table of Articulations of the Bones of the Skull ......0.0cceeccccececeeeeees 176-179
Description of the dorsum of the skull ..........ccceeccscccccercccees 179-182
Description of the base of the skull. ............cccsscceeccsccsences 183-185
Description of the tympanic bulla... .......0-.cee ree escenecceceerenes 185
Description of the mesal aspect of the skull........ 0. cee. ee ee ee eens 185-186
Description. of the lamina. cribroga. . ois cies + wstee dite cinveaengdecsoegees 187
Description of the mandible (lower jaw). ..........c.ccceceeccsscccese 188-189
Table of the Foramina and Canals of the Skull, with Traversing Structures, ete. 190
ERP UEEUNE OF BORG 6 Goss ae riibe tae CSC aes Red a ksiha hd ge eeale eyes eee ees 191

CHAPTER VI.
MYOLOGY, STUDY OF THE MUSCLES.

General Considerations. ..........cccecccccecss iL SOY pte de tetas aeesalaeae & 192
Warlation in. MUG e.iodisengainnicivss soeeperaaet dveas Ge a sth yeahs 193
Errors of manipulation and interpretation... ........... cee cece ee eeeee 198 -194

TeCRTiCGe TD PUNE OF DEG a ioe iat nine ass on Lv do wR SA SHAR aL Ms RYE 194
Muscular groups—Subdivisions. .. 0.0.0.0 sece esse esse cece eeccceeece 194-195
Parts of a muscle. ..........084- Sahelian also ate b's/ WS Reales Perrt ce ery 195
Attnohinens Tues and BIOAS. oS cyc. ple pi seek shh o eps oomes¥ ooReSemaN 195
Origin and insertion—Choice of origin and insertion. ....-.........66+5 195
Determination of muscular homologies. ..........+..eeeeerec ee eeeeee 196
POS fer acera Corel greperthajeloscnasral Oar are is WIE eat be ea os cal prdalnoabal ala main fale glols 196
DORR OE MANOR 5 Geass ya Sas ar Pe MASE RY AS alee 05d tp pS spades 196
Designation of the borders of muscles. .........escecuccecscecsscevees 197

A NCOPAMIE. FOR LABHCOLOR Gav ahaa AS RULE E Ne SIe ase + a8 9'ecg ga cites Noniee A da eage eR 197-198

How to. use Dissecting Instruments... oso. sss ya’ 5% cog vcs bas Soe destin ee cae 199-201

PCGHOGL Bagiestians. 6G DisMecl ore) ioc dain eden novo a0 op saws Blog ABI 201

Choice of specimen and removal of superfluous parts........+-..--+++ 201

xiv CONTENTS.

PAGE
References to the skeleton .......... dante eweae bas dale sabes 3p 202
TREISIONG 1056: 6:55 sis sje ce sviaes +9 04s venegiens wie deneiens oeiel aera MMC Guais weld ao 202.
Vessels and nerves and action of muscles. .............cceseeeeeeerees 202
SPRMNSECHION OF MUBCLOB.:« 5 o's5 vi 55.6 Ninly 84. 35.0 TEE b a's idye Viele MC Dia NG wD 208
Covering and moistening parts under dissection .............e0.+.05 ce 203
Common faults Of. dissectors 2.2'20...5 5 6 <a cited NTS cna» einige dane UaYaayeeicse 203
Clipping the hair, cutting and removing the skin.................... . 204-205
BGO MOTB 5 0/0'0:a50 sivicin ovis Vicie elas Seca digth Os eayembeinnn wees bevels 205

Description of Certain Muscles...................00000- Be ee We od clatowse 5 206-271
MESEMOUR ‘POTHMOG 656 5.5.4.005000 6455550 NGs be wctnceseteneeoeudns deletes 206
Pierors And WsiOohe 5 4/. vs aes Be a's Sabin de diord 8a Delp nndiageled OEE pe Uiie ais nae 206
NainGs Of: GHG AMUSCION 520) hes dise ses Sts Khel dF sdlodgee dnd bona seme ees 206
Table of the muscles treated, with synonyms ................2.e00e00e 207

TPADMAUS QYOUD 5.5 55:0 85h 3405 too 00s ou pela dab sue pabe Sheechedectes 208-217
AAOVOLAD, VETNBPER £5, 415°3.5 acd s,s icia bce aieioraleleiss.c'e eoeiaig ial ertoveles mieteig Wine BIC 208
Exposure of the trapezius muscles.........6...02eeeeeeeees Pe ae 210

Attachments of Muscles to the Humerus..........045 £6 ca Wcgie datas mentees 227

EER ATED AN. 5: Sanaa a tease SS a Se wielasAre® varies sl a abiweieiiehepaceas 233-241
General remark on the pectoral group. ..........2.eeeceeeeee eee ee cece 235
Crossing: of the pectoral elements. oi 55 Fi... cs ee cas ds Se Valse valeienwe oie 235
Complexity of the pectoral: muscles... 2.55 ..0..c.cccecesccccecseesees 235

Arcus Bicipitalis, Bicipital Arch... eee cedecssceseecvevecssccsecucevnce 245

Muscles of the Shoulder Grd Arma ss via dst. Os een Gee baw s eee bel tie ds ee 247-271

eructere of Muscular Tte0ue:. hee ORC See Os VS ae aa ate Mek side Cae RON Ge 272
Muscular fibers, length and connection with tendons............-....+ 272

CHAPTER VII.
ABDOMINAL AND THORACIC VISCERA, MOUTH, SALIVARY GLANDS AND

NECK.

WMaGuiinal VASCOTAs<. ci civcens eebsuldsiweebaswise a parce tie oe aiiGeumn ees cite malay ots 2738-297
Peritoneum......... Sie area eonra SAG a eT OKs cy ae RING o MER a Sielaievic cbabee nweis bu 277, 279
POAT AGING so ig. 55 3405 o'e¥0 se « orleis see sat Sema Cae Oe Wat emlay sith» aes 277, 311
Hepar (liver) and Cholecyst (gall bladder) .......0 . sce ceee ee ccec ee ceeeeeens 277, 286
Lobes‘ of the liver: and: its Qicts sists. < s.0.00 bs 0s 4 vmaeelv ale tb elie soldi alae cae 286
Stracture of the Livers <0... Soles ele satis Saiete s eset sae Sete 287
PACONTELCIEUD (SCOULACIEY SG Iau vie: 4 2.8 o wie ae #6 RW EEG ww. io'gaes baie Wie bi ewis lars eraack bi 277, 282
Small Intestine, Duodenum, Jejunum and Ileum, and their Structure....... 283-284
Large Intestine, Caecum, Colon and Rectum, and their Structure. ........000+ 285
SUNN ANINOONY Fi 5Fih ewe ARN WA acon sas dikn oi vta\e Ew dere ole OT UOM RG Ob als BY Sew Were 278, 283
CMENSLIN -MAGUC OF TPAMOOM. Fao bie Odin Sek Vode a eee ees baweeBaoes evan’ 278, 280
- Foramen of Winslow, mesenteric glands...... qe RR Ee Teer Tes 280
Pancreas and its Ducts, with the Ampulla of Vater .......000-seeeeeees 287, 290-293
OTE MICHERILEAL) co 53.5 utes grater ahah doa elo aned a wlere Sion evan als Peviavat awfierors ARa ea ia ayatelwubnla tole 278, 294
Ureter, urocystis (urinary bladder)... 2.02... cc ccceccesceeccceetseecs 294
RGVOD AL DOGY sda etets ate x vo Se MII SA S.niere,co.0 Hein ws sre ea teeny SSE ahs WG ala canereal 295
Uterus, Fallopian Tube and Ovary... .cccccccccccevscccsecceccenseesseus 295-296

ae Ya Cir Se eee ee oe eee ee ee eee eer ay tree ay ara aa 307, 297-803

Preparation of the ducts.......c.cecceceeceeees Coo DEUielaiids Wie Kaew eh 298

CONTENTS. XV

PAGE
Exposure of the salivary glands and their ducts............-.5...00005 299
Nerves associated with the glands and ducts...............00.eeeeeeee 301

POPE GHARE io ae CAS a cia tls dates Geiser PVE, Sosiwes YAS LGU REEF Sees 301
SS a OMe asics F526 Vag tot Ws oie nae Ole ba KN Sy ONS Oe SRsiem Ee NpeAAaEhS 301
Accessory parotid glands. .......cccccecee secs n reeset eec secs eeeeese 802

Submavxillary Gland........ haere £lae cian eaeed ete snd sks Made ean 302
Wt cab br siy Oh AUG s os a be ory GW 0s ct SET Ne dk 408 AD Ce eae re GE ee Sal emagey 302

Sublinguial QUANG. 2... osc ce cence siete ee se ese scecenec eee esse eresens 302

EAE cae acwle.s vc cea pineal? Cows doug s via ah ede Meee a Luke Cokie et aie 302

Vpomnabig: GUI ca os reas 58 0's 4,68 9.00 2c C4 Flo 4 90010, < s ncawinie, #9 Sind 4: dia SA SI 303
Strucfure of salivary glands. .... 2... 2+-eeeeee eee e cece eee eee eens 803

Cavum Oris (Mouth Cavity) and PhArynd...ccceccccceccececceececsee wees 303
Structure of buccal walls and tongue... .........0. cece ee ec cece ences 304

Neck (Collam) ait Trachea.’ 020 os secs ede ve vecavescscesseeshetaseve se 307
PePAGEEe OF She LACHENS. 5 Fs di Nada cic talc ema ddeccawanedeus ssa cuerpo 308

CROMER So ree co 85 Rate Gb 5 OR a Oe Cele ce Oe ae ERE Maree oe ere SON 808
Stracture of the wsophaguss 2315. 666005 ho. Sede Soci vewe gen were rare 308

MME Fiano din Ses TER whan bah oPOSE EAH TG chm e ae BS TNs Saws AES POT Onda rinse EMS 308-314
Pleura and septum mediastinale... 2.0.0... ccc cece wee ce ec eeeseevccece 309
ie SENIUNE MPPIMR Cee Notte shane re OG ats di delale cela siaie's oe cw eS 4 wE OS trelasiarn slave ates 309

PURI RE cee aMe a antl ite die eee Sh Toe aS ee ene teks hae hee rade oun ti atere en aleitie ors 310
Louver and alr celinof the Tanges: 320. di. cidaecsences accevavawes bade 310
PICU ERG BPORCHION 5 cc ccs quan Uae hs Ch avaciace shite cay sie eee @ 311
SRPeCters OF $h6 TANGSs Sires ons. cca ene ces tages eine ecctueteg geste 311

PAMMMIMEN AT eae oh ae HSRC EERE Ss ota AUST PETANEN ELS hg Me Oh aw eee oom 311-314
PEON E MMMNE SS satel Cotas cast aw Le canes Sata te eRe Sa sive ERT EOS ee 811

CHAPTER VIII.
VASCULAR SYSTEM.

General Cansiderattong. oho. b.02 vice n'nis.b nS aad MES Raa Speilan WOME SSE 315

Blood Vascular Systemics: 2 stadia vari lac in eda er Rsieak ied wold wohl Lwinie eh 315
Arteries, ‘Vers ‘and capiaries s.. 5" (ess ss5 cs.a's0u d18d Rel Melodie de selene ae 815

Legh Faas, BRR G es aso 8 nic 0 ANG Ge eS clade he Vis 4b AGRE aa 315-316
ERT DRAG WOMEN erica s,s san > etnies avn RROD sik de BUS 6 Aor hE AE 316
Chyle.or iactea) wempele ois hairs asieddan ditwea xa she takes Doon eda gn 816

Comparison of the Lymph and Blood Vascular Systems,......++00000+0 iach 316

SECIS TIROT Eye eee 5 ck SERS k cack in CN ee aw ok aK eh La LOE FAD RL MEL 816, 338
References to the heart and eniks Pelee ms Hote nA A a dm ube Siegert os wares 316
Location of the heart..... ape ofa eae coy orale Pieniaid «cist epic aalsls ele eiaua 317
PICARD aa aA SP e:< cave aeeinalay die bes ale ddsin «00s cas RMAs Le 317
Form and normal position of the heart..............ceeee seen sence ees 318
Designation and recognition of the regions ............2...eeeeeeeeeee 318

EROUNQOGE OF Slit LIME os x05 Si et anh accia bain mies EO Re el Ui atdg Nettle 282 319
Separation of the heart RrO EG ANON ir ted csmisis ons Hise adie Sa eR De 320

xvi . CONTENTS.

PAGE
Removal of the pericardium and blood..................0 a oeiad PARSE S 321
Tying the vessels, injection of alcohol and hardening 9 ee seletseeis deus de 821-322
Table of the Principal Parts and Features of the Heart..................-. 322
List of abbreviations of cardiac names...............2ee008 cece eee 325
Descriptive list of the parts of the heart, arranged alphabetically........ 325-333
Dissection of the Heart... ......020. ce eense 915.9 ha 6S Sa Casle laughed ess 6.0 337-338
SIeMNEEL UPC CRONIES. OF CME 0 WOLDS 0500.55 555 devs ons siacwiedbactae Rr auk cures ce 338-342
UOMO A NIUE TEMMM yw 5226 a discne O85 0 ab Woe cob oh eho es bes he cem nek 342-362
Table of the systemic and portal veins................. 2.2 cccceeecccee 342-343
Table of the systemic vessels of the trunk and arm............... ...- 343-344
Veins of the Thorax................ Noho Sita pees eerie aca Ss e++ 849-850
Perrovies Of Lhe 2 ROTRS ANG B00 6. ois. sree enans nea¥upes oseehs oe ales 350-355
en Fe ee ne or eee eae ak ape ae pee 355-362
RE SEOUMOD pisnh SE eS eae Wk > wig wm be es i vis wes wir oh bg aa ie ot Bue aa ak ene 355-356
CP AO ROUNEIEE VCMING eo oid cinco o owe a tis bod ona 6c ae see a ones + San hea 356-858
Aorta Abdominalis and Branches. .......2.cccceennnccccccccdacevscscuees 358-362
Divisions of the Aorta Abdominalis.............++4 eee gh irate es ssats ise 361
Structure of the Heart and Blood Vessels. ..........cccceccccesccccscncees 362-863
Thoracic Ducts and Lymphatic Vessels. ...............20.ccceccseccecsess 363-368
WASH ONVILORS-2- INCLORTA Soo on soos ae ous 0 ses ode bn stele vo OO Sees Sah E EE 364
Roceptacultin sob y lis. 56 sis eos ss can snes caoeeSpvawers Dees esse 364
Ductus thoracicus sinister et dexter. ..........ccccescecses cosccseces 364-365
Lymphatics of the arms, legs and face...........+0.2e-ceeeeeeeeeecees 367
Injection of the Lymphatic Vessels and Glands..........0200eeeseeeeee rye 367
CHAPTER IX.
NEUROLOGY, THE NERVOUS SYSTEM. |
Seen T C, OIMIOTALIONS 5:5 «56, <n: ye ida's's peas bt waas bwe's 5 bins cts veut ones 369-872
Nerves, ganglia, alba and cinerea... 2.52.2 ices csceccccescccesvecceccs 369
Primary Divisions of the Nervous System...........-...-- eee eee cece cece 369
Central and Peripheral Portions of the Myelencephalie System... ..... «+. 369
Myelonalsalba and cinerea . 0 .cci- seeps 6 sia Sslcig sae eS 6 cae icine Saleitos 370
Motor and sensory nerves and rerve roots. .......--..e cee eee e eee e eee 37
Functions of the Alba and Cinered. ........5 cc cece eee e eee ee eer neees 871
Analogies and Differences of the Nervous mad Vaseular Systems ..........-. 371-872
Myelencephalic or Cerebro-spinal Nervous System. ...........------se00-- 372-094
Myelon, Spinal Cord... ........0..40-4+ isa write totale aAheton ata CRE Gs alate Np Dees 372
iM yelonm. oF Litial NGr06e 35 556 o oo SK BRIN Se 373
Dorsal and ventral (posterior and anterior) primary divisions of the spinal
MONVES va cicias Gere ntoe als 42S ARES GEG REST 6s SROER ROS Out sly tei 373
General Directions for Dissecting the Nervous System. ......+.e.0eeeeeeeees 375
Demonstration of the ventral primary division of the myelonal nerves of
SO MOTE MING. 5 oie ny tn eue Seabxw: Vases es MER ea eh ease hh Mae eee 376
Demonstration of the dorsal primary division. .............0.+eeeeeee 377

SUX POSUTS OF EHO OTALING 5 25.452 iso ores ors tide Sas See Seine Owes bee ke Se eae 377

CONTENTS. ) xvii

PAGE

Brachial Plexus and the Principal Nerves of the Right Arm and Scapular

Se ee ee Sn a cn OE Lr a ke ace 379-387

Nervus Vagus. ......0..- 0000 eee cece cece eee eees Hee PiChas eae kode weees 387-394

Nervus Sympathicus (sympathetic nerve). .........ees eee cece eee e cere e eee 394
Superior cervical ganglion... .... 6.6... ee eee e reece cee teen eee e eens 395
Thyroid or middle cervical ganglion ..........seeeee sees senses eee 895
Vertebral or inferior cervical ganglion. ..........ce cece eee tee cece ees 395
NN. splanchnici... 2... 2... eee ee eee eee eect ence et eer eree ee ees 395
Ganglion semilunare. 2.2.2... . cs eeeee scene eet e ete eee ee eens tees 396
Abdominal sympathic..........0.5- cece eee eee cere eee e een e ee en enees 396

Relations of the Myelencephalie and Sympathic Nerves...........+0eece veces 396-398
Structure of Nervous Matter... 00.0. ccec cence evec sec eee eces sees ccenecees 398-399
CHAPTER X.
THE ENCEPHALON OR BRAIN.

CPGNBERE C ORSIGOTREION Ry one ooo secs nse cc» oe eens Fees seat a eae na Chk tees ee 400
Importance and difficulty of the study...........ce cence ce ece ener ences 400
Methods of studying the brain. ......... ccc cece teen te eens erence 400

Consideration of the Brain of the Frog and Menoln anchus as Simple Brains... 402-408
Partial vocabulary of encephalic names..........22.eceeeser ee eee cece 403-404

Enacephalic Segments... oc. . woe ceceesccnwe venues. cesee Prey re ny CETTE Pe 404
Names and synonyms, tabular arrangement... ........0. 02 cece e cer eeeee 405
Unequal morphical value of the segments. ......... 222 ceeee eee e eens 406
Advantages in using segmental nameS...........eeee eee ee eect eceeee 406
Warnes, of the brain Cavitleny ss dost. occticse ces ene sm cana cgans 44K ea 406
Objections to the names commonly used...........0..25 ceeceereceare 406

Amphibian Brain—Tabular Arrangement of its Principal Parts............ 409
Fei TRIER TOP OMIGL Baas voce ed CCAR SET eS ieee Saree REReeS VeKh ee CLIe 409
General Constitution of the Encephalic Segments......+..04 «+ ceeeseeceees 412
Metencephalon, epencephalon, mesencephalon, diencephalon, prosen-
“cephalon, rhinencephalony « .....:06 sic cececdecc cess erevicnentnesads 412
Balations: Of thie C002. cick cas ies en casasucesetateedinsrecessv sees 413
Comparison of the brain with a house............:.e ccc eect eer ecee 413
Avachnoides; Pid; CHOY Mayers asthe Aad owe Gabel easy oe ea gees bee 413
Tela Q1sk PIeRUBONS 5155 shade dacs Fete Legawa de omige ete eee s eet 414
Foramon‘of Magendie ono oc5 vie ossiss nies eens sn eves eee ee Br .... 414, 482
Complete circumscription of the brain cavities................2.e ec eee 414
CDDDTIBE TUES oi s.0,0.65,pas eae ead ee Reece ae PEERS PERO E ae eg 415

Soe aga ak | Sines Aa eagerness ESAT ooo oie in coe asacews ere vin vido sceamins incon eee N ee 415
Obtaining and killing the animals .. 2... 2... cece eee cece eee eee 415
KNORR BE GinO HRP os fase gs ian Boa Scher alae lsat a adic vorersing, EDI Hee Fe 416
Mspocure OF OR eis. oa a, dena Ah che kas dh imdmer ve mie FavsaUe eves 3 416
Exposure of the brain of Menobranchus. ............ccceeeee see secees 417
Preservation. of amphibian brain... <:.:iiisiaoc seis ies len he ee eee dew ets 418
EAU Ds ceo nen oid Aaa FESS Co cM OPER NS Coe aba eae Us CN iS 418

General Inspection of the Amphibian Brain... 1... ccc cece cece nee e ewes 418-420

Xviil CONTENTS.

PAGE
Removal of the Brain of the Cat with Cranial Nerves...... ona thaw shames « 423-428
Removal of the duraviy.ccs sce G45 56 boos 8S PERN Oe bo ne ae ee ea 428
Transferring the brain to alcohol, weighing and removing the pia ..... 429
Other Methods of Removing the Brawn. ......cccccccccsvecscccscensreccens 431-433
By nipping away the calva, and application to the removal of the brain
OL Infante, eo os vie odd cahewins oc Seles oe Ta MERA aoe Dae rene 431-482
Hemisection of the head with a saw........ccccccccccccevcucscccccccs 432
Mesal und Internal hemisection .. sijassscsescsecreesace Mee wet eceie ee 433
ardening s hemisected rains S25. 5.sss1s 0's ve sae s pried tae uh Bol nse 435
Zine Chiorid Method of Hardening Brains. ..........cccccccascccccccecces 435
Injection of the Celia with Alcohol and with Plaster. .......... 0000 ccc ceeee 4385
SOONAO LF GAG ECWUIEE S55 6.5) 55.0.0 5,028, 0:5,-, 0,08 9.4.0;0.0 SOS aS WE tees Ba elec 436
Macroscopic Vocabulary of the Brain. .....- 26s... ccccccscvccsccccyccvcescs 436-438
ne OE CRC CURTIS BRTOG 6 oi 0 os 0S nsec ches civ erinterwaes peaanaas 448-449
Mncephalic Berynrents tn Che OGb. onan sn ciccnsdisvnvicasderceretsoncenweces’s 439-461
Differences between the brains of cat and frog............-.--0eeeeeeee 439
EROTIC EAOTA EH ONS DORN eS oon abba crenpemicls side woh 00. 05 bie sesiee dine At
Enspection of the mesal-eapect... ...2.. 6 cee as cece s nesenscees deperesies 446
Segmental arrangement of the names of the brain................0000. 446
Examination of the encephalic segments...........+..- see ee ee eeeees 450-454
Aula and porta or foramen of Monro. ..... 22... cee ccc ccccc ccs sccece 454
Demonstration of the Procelia, Rhinocelia and Porta (lateral and olfactory
ventricles and foramen of Monro).............--2200005 ace a 454-455
OS oy gL) eR TD Ee ea) TS OPE PY PvE OR ae, gna . 455-456
OPC — A Esinl TAREE So a Rig cise 8s 4m Vigo 8+ wig s one bs pie ok dss oh Rusielas.d 6 SN Tea 456
Pracommissura—Hrposur e's osc c csc cnccvccvaccosvesseseessecesecevess 455
Relations of the plexuses to the membranous walls of the porta, diaccelia
Mile SOMO 555 Lele he ck sie co ok Ue pial dewnreawian's Woe sine en? 459
paxplanation ‘of the Plates of the Brain... « .).50.06- 2<00s05ss0 tive ovsndscccens 461-471
List of Encephalic Names with Synonyms and References, alphabetically
MATAR e865 isis we pwede aceele bok cing wleais kale sin iad o@ went ROG 471-491
Comments upon Figures of Feline Brains .......2.000ec cece nece cere eenees 491-493
woe Cérebrum aud its Fissures, ¢... 5... 66 cccccsi tee ys deeVevscedacees sees’ 493-500
Ord OF Mie OOFOBTUIN oss b's coi as ole ivetsap s<Se<v ee WaietOwsrne vers 493
Fissures of the cerebellum. ........0.ecccsccccccsssecceeccesoceceece 494
Table of Abridged Synonymy of the Cerebral Fissures........+++0000008 0008 496
The three problems connected with the study of the fissures..........- 497
Formation of the fissures. ..........06 cc 00 eee eee eer ee ee cree eeeeeeees 497
Structural Relations of Certain Fissures, with a List Seis etree? Saad 497
F. callosalis, callogal fissure... .......c0sccccccesesereeecseces cuneses 497
PEND. 6h Nang go cen on naan et cgn anges bc FOOMIN STEWS VES OE Neo eee 497
F. hypocampe, eerie Fe SE 2 See ary 1s SR Reet 497
PaPGAU MOR. 5 obo 6c 5c tac os esta en SSbSSe Nees VEE RAMEE Coen ee sR Ueno 498
Be ER ists sats sar ecte te oceleeye Siig s.ste eG Alana faa eee isiea ele cleat wdape es 488
BE AMCTNOR 565 sists, awd eolees x kcw Annie PON OENOR SS acd KWAN SS oda es Sivas sive 498
F. cruciata, Crucial or Cruciate Fissure... ccc cc cece cece cence een eeeeeeees 498
Constant and peculiar characters. .......... ccs eeeeeeeee ener es eeeeees 498
Variable characters—Names and synonyMS..........22+e+eeeeeeereres 498-500
Homology, with views of various authors .........+++++++++% Siweseeek 502

CONTENTS. xix

PAGE

Designation Of the Gyre o.oo n ste css skew tnne oo oor 9:0 97 vlelanareie wieidieiesie 500
Table showing three ways of enumerating the arched gyri............. 501
The angular SYTUG «soo. cis... o.e.cinjsis, fore rigusseveiese aise ditiyises goleics dane aene 501

The Fissural Pattern—Constant Characters. ...0.scccccceccccrececsveeeees 501
Relat Af QORMEANE ROBUTOR 6 oi0 5 oc clais 4 6 4.0 4s neaieiee nice miele KAO penis SE. siee alae 501
Variable characters of the fissural pattern..........eeee eee eee eeee cere 502
Bist of inconstant, fissures's < i:q.5/ci6 sls chou are ea asic stone niorstens © We ase mmeleniwe 502
Homology of Human and Feline Fissures, with Difficulties... 0.2.0. +00seeeee 502
Promising lines of inquiry... ... 2.00.0. csecersuseseesss sos wlach, ene apae Aap 508

CHAPTER XI.
THE CRANIAL NERVES AND THE ORGANS OF SENSE.

Cranial Nerves—General Considerations. .............-ceeeeeee eee ce ec eneee 504
Comparison of cranial and myelonal nerves.........+- +2. eeeee cece cree 504
Table‘of synonyms of cranial nerves...... 6. 6. wer sane S508 Swe ceisene 505
Numerical designation of the cranial nerves by Willis and Sémmering. . 505
Physiological arrangement of the cranial nerves..............00see0ee 505-506
Sensory nerves, special and general............ccecscecesreccesvucves 506

Special Consideration of the Twelve Cranial Nerves............-..0..00005 507-510

Table of the Cranial Nerves, giving Ectal Origins, Foramina of Exit, Distribu-
WROTE NAT SP IMEIOUS 50's E978 oS EN WG 80s Minn Go nid inh iednend ba 91 8T ete Nieto eee 510
Directions for the Demonstration of the Cranial Nerves. ... 6.60. cece cece eee 511
SRRC RENE CT QHOMOG Cle io Cha eo (hina 4 ei sinie wn 0X get ome ha bicierguan KUNE Ste MMU we 511-533
LAR IMOP ATONE: san eiu es ie hyd ds og dloveess caxele vlneweet a” Pine ob vat 511
Skin, tongue, nose, cye, ear, general sensibility....................005 511

CEGEIG At OTN Diy. rites 2 als wierd Oe kis. be Riy Ce ME cbs age pervs ek Gan kuna boy Smee 512
Structure and function of its various parts... ...........66 ce eeeeeeee 512
Appendages of the skin—Hair, claws, sweat and sebaceous glands...... 512
PURCELOPSEIR our sti aretajecale rns alascrecK oi aileWh asthe ncaa ee rela share wate diaysinrecarenerergsersls 512

Lingua, the Tongue—Uses, papillae, nerves..............004 ceeee cence eeeees 512-513

Nasus, the Nose—Lining membrane, sensibility of its various parts........... 513
WRLOK, PYMDALEH BNA POSWNGTOS s «6.90 ds bivic dere siacn bc oysnaele nag vidisw sia aare 513

RI CUANS ERO PCO al ong o- sl herntals a cataatn sioree sé srereinlds: tie da old dip Bun aiaclaepoiea a wacculetes 514-526

DENA OF COOUD uo eara a ore sia aig ole dha AAO BITE Naa WR padiale phere ieee 514-516
PRIA OR LO ain oa aa'o ele els ws. Goss Halt © Sid AA MEK AMOR hia TO pe Raa 514
COMI 0 5g € orn, 4 eAcilticg Bat Ca db o'sik FARMAN eh hid ei SAS Ge wed inie dy in 0/4 cso 514
WMBGE OD EUG MOR «oc R0e 2 hp tbaien am Ghee Ke bs Matyas aah Vira Ae a vce. ates 514
PURO UIGPURLMARID: MERIESEIS oor dtc aul aden SECA RES BERR GO 8 eel e AN ain ne, Sova 514
Membrana nictitans—Attachment and office...........-... 2 eee eee eee 515
EMORT IRIE MENIOTREOGS «Siete chic GA A G.8 eos. o0 ck eb 6ks «Pee tin ee xaiaiecee és .. 515-520

ROMMNORDT LAO LUGE SR 6 cu aa Mag ee GRE MAA Ce aT SS pea SMe bcia a0 Sa aie vO Ee 516-520
Origine OF- the MuUsClOs OF the AVG. o..oea coeds csjode ob v's veces sane eee oie 519
Action of the muscles Of thie G90, 12.5 2s het e ese ciiaewd se nece gene connie 519
WGEVOUS SADDIF OF Ue MURCIA 6. ci cc's are tv's tose kiewed since he melee soe 520

CORED CUES, LOBANAL ss x ected 4's Wdlwtan (oes Bicol dhe’ iene ton vie Me Schl etg A eKES 520-526
How to obtain the eyeball of a cat, ox or sheep............ Othe ahivacs ae 520

BOTH ANG DACs OF CHE OY ODL Misc. ds adore Scvefeieralaie os/ele.-@ ele'bcl eg s(e ere 0 ota 520

XxX CONTENTS.

PAGE

Sele BNE MUP «50.20 cobs Lc dn ae eeevines Sor eRe cece reMee Eee Oh 8 520

Images formed by. the Gyess. Wee ois Lest Ae okr ce eee eae One's « 520

Tonics or eoats of the 6¥6.. 4. is..8axehy .sunneasunnee mentee fends coke 521
Preservation of an eye in alcohol for the coats.................00-000- 521
Sclerotica and. Cormesy 66 ose b)b-ayi sah siddar latte ieee larvae nae wk at eb ences 521
Choroidea, phice ciliares ). << 2:5. 5s Sip aes ccawitite dem thin Moree w ca ees 521-522

Retina, ora serrata and pars ciliaris retine............ 2... cece eee 522

TP OEWI y. 6k 6:6 sss WORE Sab ORT ER O Eo PARTS ee aa aes Teen ss 522
Aqueous humor and aqueous chambe®s. .......6... cece eee ees ee ee eeee * 522

Corpus vitreum or vitreous humor............00.cceeeeseceeseeeseees 522

Lone, ligament Bad ORPEOle wos: ce ss 8 OS So weds ami sess we Ones a Rk ke ees 522-523
erannm Anditus, Airis, Rath 5.5.8) .'b. 5s das dies Po soa sinds Henle she eas’ 526-533
MEPEEN TURE ULI Grae sins eee k sie wieie: tieleielbis We Oe Sa aS aA sem Nine eae Rane Ss Lele s 526

TP DATG A IUGAGES TORT 38. ops 5 SS 58's hohe sees Eta oa Eko ene bs clades oe 527
PAGERS MPU DOIS 6 os ose pn Selene xvas enw shee he RAN 8 OA ve y Hae we oh os 527
COUR MRP ARE: OS DLLs chs swans eee tae ne be wig seek tes bab ar et 528

Malleus and tensor tympani muscle............ Se aan AY sieek ne ae haa 528

ENOUS BO OO TORMCTINNG £05 ips. 5 <o:coinsh.s ome a5 48 Se theres wy ees bgeee es 528

Stapes and stapedius muscle... ........- 2c cece cess seen enon nese ernene 529
Labyrinthus, Internal Har ........ cece ee eevee Pe ahh ts icy A ye INR 529
VGURIIITLEDNS: osc a5 wlecit eG wvadie a0 5's be opts Sie anep hes a's raed on 65m ORN'SS 529
Fenestra ovalis and fenestra rotunda. ....... 2... e ee cece ee eee renee eee 529

CMM ais Pty 2k pea ein etna bts Uiaie ost. e, WR ye VE se eae EEA See 529

Scala vestibuli and scala tympani...............eee eee eee eet ee eens 529
Modiolus and lamina spiralis. .........ces sence e see cccccceeeecesissens 529

CanSlOd HOMICEFCOLATOS ¢ 5 oo 2:2 civ. 6 sik e Samer V.t oS masa sinc eleeais Aa.eis wes 5380
og 2 i, CONS oe ae = SERS EAT A PERE Set Rete ah: ee hers 534-537
NCR CEs Saas Visio’ ae mvs Wie Sana Gh Ese n's SEAGRS S69 ap b'sG Dies awe As 538-553

INDEX... 0.2.05 TEs i Le eee ee aly Sided hia. < ing U4 Rise. ais ia ies 554-575

LIST OF ILLUSTRATIONS.

In respect to twenty-six figures we are indebted to the persons named in parenthesis,
either for the idea of a figure or for the use of an electrotype. Of the original figures, the
larger number were drawn by E. C. Cleaves, Professor of Free-hand Drawing in Cornell
University. The four plates of the brain were drawn and lithographed by Miss G. D.
Clements, who also drew Fig. 81-82. Fig. 11-12, 14-19, were drawn by Miss I. M.
Curtis; Fig. 124-127, by Mrs. 8. 8. Phelps Gage; and Fig. 92, 110-112, 121-123, by the
senior author.

In preparing the drawings for the original figures, the specimens—now preserved in
the museum of Cornell University—were photographed with a vertical camera, as sug-
gested by the junior author (6). The outlines of the drawings were traced directly from
these photographs ; hence the relative size and position of parts are accurately represented.
Finally the drawings were photo-engraved.

FIGURE PAGE
1.—Paper Meter Yard (American Metric Bureau) ................ ee eee eeceees 6
2-4.—Diagrams of Three Aspects of a Vertebrate, exhibiting the most penierah
as i Sarees FLEE CEM ST UA CEE eh EE ELAR LRT ERS COTTE AS 30
5.—Diagrams of the Three Body Planes, with the various lines of direction... .. 34

6.—Diagram of the Dorsal Aspect of the Cat, with the limbs in thenormal position. 38
7.—Diagram of an Ideal Transection of the Thorax of the Cat, with the arms in an
approximately normal position, and showing the location of the principal

FINGER, elaieo sieeve ae eee ey ev ewerae esas Sees | Ieee cedseneaess 43
8.—Japanned Tray for Catalogue Slips (Readers’ and Writers’ Economy Co.).... 50
9.—Pigeon-hole Case (Readers’ and Writers’ Economy Co.)...............2..00 51

10.—Stubs’s Nippers (Codman and Shurtleff)... ......... 2... cece cece ee eee cece 62
A1=13-—Nippors and Hine ScissOrsenss sss os cles oes ce tae rks Soak cease weekereesees 63
138.—Small Compressor (Geo. Frost & Co.) . 2... 0c. c ee ee cece eee e eee e rece ceees 65
14—Blunt-pointed Scalpel........... SUAAETENS Seas ee eRe ease et cures eee ese 66
De gcse OS we rs SIS Pat eh Parke Ess ne ae Ee ee ier mop 66
IG SATthPOpome ee con Coa dare eT eo E TT LG Cantera oe Leste see ncpee eens 66
Ri TIREOES eas Uren s ce Sew eh Maaco IHS EST S O's seed yee vaio eee s 66
FSGS: POROG PR Fle Ieee CER GIS COC CRS ERA ONG be V ewok ceke dele oe wlede 66
1D.—Flextble Blow -pipess2.ntscetiv ccc cee Ue eee reas RSE ate Pee tal 66

Pa N es CALVON POMC Sie sso sees ees eee le LE eealede Usd lola iecewhvae vas 66

xxii LIST OF ILLUSTRATIONS.

FIGURE PAGE
21.—Back-saw (Goodnow and Wightman)... ......cccceecscec cece csc csccscccccece 68
22.—Large Scalpel (Codman and Shurtleff).............. seth ee aeia tates behets 69
23.—Medium Scalpel (Codman and Shurtleff). ............. cece cece cece cece te eees 69
24.—Charriére Scalpel (Codman and Shurtleff)... .......... .. ee cece cece eee payee Te. 69
25.—Coarse Scissors, curved flatwise (Codman and Shurtleff ) Sb tole We Hotaiale ‘so put ersts.% 70
26.—Tripod Magnifier (Smith and Beck) ............cccccccccsccscccccccccccceecs 72
27.—Wetting Bottle for 15 per cent. Glycerin .........0.---cecccccccccccccccccece 72
38—Honing and Stropping Bnives «6 ssid sedis oa wea dean dke Wood ses 85 cc ccs eee 76
eA NOSTIOHG DOS 5/2 parse viS 550s kbs aan as lepine resins Wem SIC a Se ore s ok ob ae Oo 81
80.—The Skeleton seen from the Left (Straus-Durckheim, A)........5..........000 88
31.—Covered Glass Box (Whitall, Tatum & Co.).. 2... 00.2... 0c ccc cece cece eee e ewes 126
32.—Wide-mouthed Specimen Jars with Covers (Whitall, Tatum & Co.)............. 127
35.—Welted Vial for the Brain or Heart. 2600.05.55 00 20 Sos oad velivinsecesde cccevene 128
Pe ORNED SIMMER sic 585s Sie hn d's oaKis nines Hid GAEDE ake ps Oo teed aoa TereoNoe eae vows 129
35.—White Metal Syringe with top unscrewed and piston removed ...............-: 138
POAT 6 Cen A BSS,» wpe vig toapis Renee Sas AVA os UMASS LOR ROMER RODEO Te ebay 138
37.—Brass Syringe (Codman and Shurtleff)... 2.0.0.0... ... cece cece cece ae eeeeseeee 139
38.—Small Brass Syringe with removable Stop-cock and Canule for Fine Injec-
cane (Seta Br BCU) os bop nasa + ois inside ¥ ACen eh akon epese. neee 139
39.—Femoral Vessels exposed for Injection... .............0ce cece ec ce eeccenccasers 142
40.—Incisions and Preparations for Ligating..................0 200 cece eecceeeeees 144
41.—Double Ligature, Surgeon’s and Square Knot.......... ...e.eeee se eeeee reese 144
42.—Inserting and’ Securing Canule........ Tai ign gb Oa emia s we hie pips abtiane Sora 145
43.—Ental Aspect of an Adult Left Scapula..........0... ccc eee eee c eet e cece cence 154
44.—Kctal Aspect of an Adult Left Scapula..................005 5 cceeee weer ecees 155
45.—The Glenoid End of an Adult Right Scapula and the Proxima] End of an Adult
Ree ER OMIORUGR 2 055 58s aie aions\uis'oain rAiveod onc REy Weis Sea mab LER S RENEE 156
46.—Ventral Aspect of an Adult Right Humerus................ 200.05 cee eeee eens 158
47.—Dorsal Aspect of the Carpal Region of a Young Lion and of two Young Dogs
(WARS E IED) 18s ocsicntames ee us ee Ra beies's,ccp 55s BSR Re ent ee ee 161
48.—Right and Left Clavicule of an Old Cat... ..........0 cece cece ees ceenecercecs 162
49.—Ventral Aspect of an Adult Sternum ..... bc Uae Stays Web eal d '»' Sess Kaaba meee owe 163
50.—Caudal View of the Seventh Pair of Ribs. ..... 2.0.2... ce cece cece ee wee sence 166
51.—Ventral View of the Cat’s Pelvis with adjacent Vertebre (modified from S:raus-
DUN OUD IND L os safacobeic aig seam ream vo cw bie sone ainje bushel ass oin(e/pa-staeelain’s 168
52.—Ventral Aspect of the Cervical and two Thoracic Vertebre (modified from Straus-
DUPORMOIMA AY 0 sos: 48's spe eueeate tae ne ave Oak Disediee Srehense yaaM IMS CS cakes
53.—Caudal View of the Fourth Cervical Vertebra ............20- 2 cee ee cece eeeee 178
54.—Caudal View of the Seventh Thoracic Vertebra.............0-cceececcecececes 178
55.—Caudal View of the Fourth Lumbar Vertebra....... Spee iprerintan postop Wk Telbs taiaee Bia ola 173
§6.—Dorsal View of the Skull... oo... cc tvndscwsicer cc ccesse ceded pes eck vienscens 180
57.—Ventral Aspect or Base of the Skull (modified from Straus-Durckheim, A)...... 182
58.—Ventro-lateral View of the Left Bulla tympanica and Adjacent Parts........... 185
59.—Hemisection of the Skull, Right Side... ...... cee ce cece eee ee eee neers 186
60.—Dorso-caudal View of the Lamina Cribrosa and the Sinus Frontalis............. 188
61.—Lateral View of the Left Mandibular Ramus........ 22.22. cee cee cece cece ence 188
62.—Dorsal View of the Mandible (modified from Straus-Durckheim, WA) Ss olen ss 189
63.—The Scalpel Held as a Pen (Bernard, A)... .....ccccccsccescenesscccccceseces 199
64.—The Scalpel Held as a Carving-knife (Bernard, A)........-.0--.00 5 eee eeeeees 200

65.—The Scalpel Held as a Violin-Bow (Bernard, A).....-.....220ceee cece te eeceees 200

LIST OF ILLUSTRATIONS. Xxiil

FIGURE PAGE
66.—The Ectal Skeletal Muscles of the Neck and Shoulder.......... Sigslamieiele ces 211
67.—The Second Layer of Skeletal Muscles of the Neck and Shoulder............ 218

63-71.—Views of the Four Aspects of the Humerus with Areas of Muscular Attach-

BOWE hs cco, Sos bore aie Doreve aIeSIEs Siuisl saielaien! shag Piaawel sl atheicie hated WialAe VAN Cee 228.
72.—The Pectoralis:Group of Muscles... ois ccslsisns cies cetaichs 2 tlelsins civielewies ceseee 234
73.—Ental Aspect of Left Shoulder Muscles and Ectal Aspect of the Serratus Mag-

nus and Levator Anguli Scapule Muscles ............ 2. cece eee eee eee 246

74.—The Cephalic Aspect of the Left Arm with the Ectal Muscles of the Scapula. 254
75.—The Muscles upon the Ental Aspect of the Scapula and the Caudal Aspect of

the: Brachiuni and: Antebrachruct 2163's odie secs eS Shs Sees bist Rind o's 262
76.—Lines of Incision for exposing the Thoracic and Abdominal Viscera.......... 274
i ——General Vv iewe OF be: VIBCOFAG) 55 a'tls.o 4,6. 79) 5, ofan ciereya p55 nore RENTS Malay sie ewts 276
78.—Diagram showing the Relations of the Abdominal Organs and the Perito-

TCUBs cic.ce ac cred watlanicac sli s 00 saw oda gidwertinwe oA alse ate deig Peis eteuie hea we 279
79.—Stomach and Duodenum, Ventral View.............ccccececccceceecececcs 281
80.—Czecum and Ileo-cecal Valve, Ventral View..............ccececccccececees 284
81.—Ventral View of the Pancreas and its Parts (Gage, 3)............ eee s ee eee 288
82.—Cholecystis and Pancreatic Reservoir and their Relation with the Duodenum

(REgo 58 )esie eens miaibin. en's Shars-arq'a\ hei car alnliple Wt MgkaGeiah Mele are Miniter gis) chelate oteerg 289
83.—Ventral View of the Human Pancreatic Ducts (Bernard)............-....0-. 290

84.—Longitudinal Section of the Ampulla of Vater, showing the Entrance of the
Ductus Choledochus and the Duct of Wirsung (Gage, 3); the same in man

(Bernard, 77) .....- aii od ain noagalanan arty ent & Cai emuareiwis OMe Sey hs Asrbtre ed en 291
85.—Dorso-ventral Section of the Right Kidney, Caudal View... ............... 293
86.—Longitudinal Dextro-sinistral Section of the Right Kidney, Ventral View .... 293
87.—Salivary Glands of the Left Side. .....5.. ewe clecee ds seasibectcacceadces 300
$8.—Hemisection of the: Head. ..2 06 <.6.<e 6 esed c0 80 60 5iclan othe 64 ab Oe Oe ele 305
89.—-Longs end: Trachon..\ js ...s 5 -.0:5 oie acd spas pias biainje sence bMS Seu oe RRA 310
90.—Caudal View of the Diaphragm with the Structures that traverse it......... 3138
91.—The Dorsal] Aspect of the Heart with the Central Portions of the Larger Ves-

BO Beck g saris wd ep wis tat ga sada a as arene ete Wak oxen us Udila tan Md otk ateues 317
92.—Diagram of the Cardiac Cavities, Dorsal Aspect.............0eceeeecee eens 823
93.—Dorsal Part of the Heart seen from the Ventral Aspect...............-.-..- e338
94.—Longitudinal Segment of the Heart, showing the Right Sinus of Valsalva and

SIA BPCOR Ys) 56 a tecaisawahes.s pee rhs +i wiere nd Wis op daenea rey ARG Awe 333
95.—Transection of the Auricles, Caudal Sepact Pig td Syl ee sei yethien Cocina eee wee 334
96.—Transection of the Auricles, Cephalic Aspect... ........00++esseeceeeeeseeee 335
97.—Transection of the Ventricles, Caudal Aspect........ -...--0.ecseceereeees 336
98.—Transection of the Ventricles, Cephalic Aspect............. Sia Oalea hee aelgce 236
99.—Frozen Transection of the Thorax, Caudal Aspect............-.0ceee seca eee 840

100.—Frozen Transection of the Thorax, Cephalic Aspect... .............20 eee eee 841
101.—General View of the Blood Vessels, and Diagrams of the Beginnings of the

Postcava and Termination of the Aorta... ............ ee ce eee eee eee 345

102.—The Aorta with its Main Branches in the Thorax and Right Arm, also Origin

of the Carotid Arteries: Veins with Valves (Quain, A)................05 847

103.—The Left Thoracic Duct, Sinistral View, and Termination of the Thoracic

NGOS: 272s hae fs sag OT RRC Et Mean STANT aie hones e2 Wi a'a 46 9 Ule's G 4d e Konia wt 366

104.—Dorsal Aspect of the Brain and of Part of the Myelin: with its Nerves....... B74
105.—Ventral Aspect of the Right Brachial Plexus and its Nerves................ 378

106.—Diagram of the Right Brachial Plexus, Ventral View.............0e:seeee:: 381

XXIV LIST OF ILLUSTRATIONS.

FIGURE PAGE
107.—The Vagus and Sympathic Nerves and a Diagram of the Sacral Part of the

Sy mpathie.. wegen Sask ulead vy eI are MORI LORENA ROE YS ote srca'e 392
108.—The Recurrent Laryngeal Nerves, Ventral View (Stowell, Z7)................. 894

109.—Transection of the Thorax, showing the Origin of a Pair of Spinal Nerves and
the Relations of the Sympathic and Cerebro-Spinal Systems, Cephalic View. 897
110.—Longitudinal Dextro-Sinistral Section of an Ideal, Simple Brain, showing the
Relations of the Cavities, the Sequence of the Encephalic Segments, and the

Relations: of the Coolie... Fok isk etwas saree o PERS ERS ae be ab bows nat 408
111.—Mesal Aspect of the Right Half of an Ideal, Simple Brain, showing the Con-
tour and Constitution of the Coelian Floors and Roofs .................000: 408
112.—Transection of Several Segments of the Ideal Brain, showing the Coelie and
ANGIT PATICCOS 33 5h. KER artorsle os eh so eaeeie ee ee ale cain als sre paues toe bis oun eis 408
TIS —=—Ventral-Dxposure or the Conlin 's 54.0152. Wise ened csencis ls owioe oee tinge e eleva lavas. 440
114.—Dorsal Aspect of the Mesencephalon, with Adjacent Parts.................4.. 441
115.—Dorsal Aspect of the Callosum after Partial Removal of the Hemispheres....... 442
£16.—Diagram-of the Base of the. Brain... oi foes i ace eek ee ctlsr cesesenceens 443
117.—Diagram of the Mesal Aspect of the Left Hemiencephalon. ........-....-: 446-447
118.—Diagram of the Area Cruralis of the Brain ............. 0c ccs cccecccccseeees 447
119.—Plaster Casts of the Medicornua Inverted ...........ccce cece ccc eceseeeeeees 458
120.—Plaster Casts of the Diaccelia (Dorsal Portion), Aula, and Right Porta and Pre-
Commu ob tie Sleep, inverted — Se Sores e is. Sic 3 Sate whe ee wc Siete ewes 458
121.—Diagram of a Section of the Left Medicornu..............-. cece eee cee ce eeees 458
122 —Diagram of a Transection of the Brain through the Diaccelia..... ..... ..... 458
123.—Diagram of a Transection of the Porta (Foramen of Monro).... ......+.+++++ 458
124.—Cerebral Fissures, Lateral Aspect...........:ee-eee cece cece cee ceeceeeeeenere 494
125.—Cerebral Fissures, Mesal Aspect.............. ceeeeeeeree: PSs st rit 494
126.—Section of the Bye, t7 sift. csc. ce es cece cee cc te reer cescececes Batts Satake 524
127.— Diagram of the Har. ...... cc ccc ccc cc cece etc c cere ceca cares secescescons 532
128.—Transection of a Coil of the Cochlea (Quain, A.)........ cece ee ce cece reteeees 5838
129.—Dropping-bottle Oiler... ......... ccc 221 cece cece cece er eee coeeeee ban ctat inners 585
180.—Method of holding a Frog for Pithing..............+. Sbebs SR eBme We Ls SsaS eG 536

FOUR PLATES OF THE BRAIN. (Wilder, 24.)

For the use of these plates we are indebted to the American Philosophical Society of

Philadelphia.
PLATE I.

1.—Dorsal Aspect of the Brain.
2.—Sinistral Aspect of the Brain.

PLATE II.

3.—Basis Encephali, or Ventral Aspect of the Brain.
4—Mesal Surface of the Right Hemiencephalon.

PLATE III.

5.—Cephalic Aspect of the Prosencephalon.
6.—Caudal Aspect of the Prosencephalon, with part of the Diencephalon.
’.—Dorsal Aspect of the Diencephalon and Mesencephalon.

LIST OF ILLUSTRATIONS. xxv

FIGURE
8.—Caudal Aspect of the Mesencephalon, with parts of the adjoining regions.
9.—Sinistral Aspect of the Mesencephalon and Diencephalon.

10.—Dorsal Aspect of the Diencephalon, including the Diatela.

11.—Area Cruralis, with part of the Pons and of the Area Prechiasmatica.

12.—Dorsal Aspect of the Metencephalon.

13.—Part of an Oblique Transection of the Prosencephalon and Diencephalon to show
the Form and Position of the Crista Fornicis.

PLATE IV.

14.—Ventro-caudal View of the Fornix, with the adjacent parts.
15.—Dorsal Aspect of the Proccelia.

16.—Rhinoceelia and Proceelia.

17.—Mesal Aspect of the Right Hemisphere, with the Lobus Olfactorius.
18.—Right Proccelia seen from the Right or Ectal Side.

19.—Left Preecornu and Porta exposed from the Left or Ectal Side.
20.—Transection of the Fornix with the Crista.

LIST OF TABLES AND ALPHABETICAL LISTS.

Table of some equivalent Temperatures, according to the Centi- cas

grade and Fahrenheit scales, -.. 2.1... ce sec ee ccc ccc ncn sees 4
Table of the Metric Measures................ RPE OTT FET Se 5
SHADIG OL MOtTIC HQUI VALORES. s tcjo s/s 0 wo 0's > 6c aie oie 22 so ss oe wie ane 7
Table of Zoological Classification...........6 cc seeeceee ee eeeees 9
Table of the Principal Divisions of the body..................... 39
Table illustrating the Subdivision of Notes.................e008 49
List of Anatomical Instruments and Materials .................. 59-62

Table of the Specific Gravities of different Percentages of Alcohol.. 112
Table of the Ratios of Alcohol and Water to produce a given

POPOORA LO Seiad va baie saniieis reavesie Ucn eh into) Ghd Salaries 116
Composition of Wickersheimer’s Liquid ...................008-- 124
Table of the Bones of the Skull, showing the Synonyms and An-

thropotomical Hgaivalents <2 s.3<5%,<+.< s'<in.e’sy otis © 4615 bisecio'e s 174-176
Table of Articulations of the Bones of the Skull.................. 176-179
Table of the Cranial Foramina and of the Structures which traverse

EEO goals cet btaes cies hie ie Toales ks io [Siac OR le ogee eS elas Odiad WI RTE OA 190
Table of the Synonyms of forty Muscles..................028 ee. 207
Table of the Principal Parts and Features of the Heart.. ........ 322
Table of the Systemic veins of the Trunk and of the Portal Veins.. 342
Table of the Systemic Arteries of the Trunk and Arm..... ..... 343
List of the Principal Parts of the Amphibian Brain, with their

MOLE COMMON BYNONVINS ss 5-.- s.3) us aio bhi s 2 58 os Aapieinin pias anes 403

Table of the Names and Synonyms of the Encephalic Segments... 405
Tabular arrangement of the Principal Parts of the Amphibian

PR leon NA can S54 tac Baran on Seen 4.0 Op aielnwieie tou ek alee hied 409
List of Abbreviations of general Encephalic names..........--.-. 436
List of Abbreviations of special Encephalic names............++.+ 436-438
Tabular arrangement of the Names of the Parts of the brain

Secording to the Sepmoents, .5. ..25. <0. sd Sec acs sss eased vesmse 448, 449
List of Synonyms and References for the Encephalic parts........ 471-491
List of writers who have figured the Feline Brain.. .. .......... 491-493
Abridged Synonymy of the Cerebral Fissures...... ....--..00008 496
List of writers who have mentioned the Cruciate Fissure.......... 499, 500
Table showing four Methods of enumerating the ‘arched gyri”... 501
Table of the Synonyms of the Cranial Nerves..............+0008 505
Provisional Physiological Arrangement of the Cranial Nerves..... 506

Table of the Origin, Distribution, etc., of the Cranial Nerves...... 510

SECTION

914, 915
916, 917

1058
1061

1069
1327
1128

1138
1180-1333
1334
1342
1361
1363
1374
1877
1392

INTRODUCTION.

§ 1. There are five matters of general application :—

1. The reference to other Publications.

2. The designation of Weights, Measures and Temperatures.

3. The names of Animals, and of the Groups to which they belong.

4. The designation of the Parts of animals, and the indication of their
Position and Direction.

5. The making and arrangement of Notes. .

The treatment of these matters in the present work may be characterized
briefly as follows :—

1. The citations are numerous and explicit.

2. Only decimal systems are employed,—the Centigrade scale and the
Metric system:

3. The classification adopted is in accordance with generally accepted
views.

4, The terminology is intended to have the following features: general
application to all Vertebrates ; intelligibility to all nations; accuracy;
brevity ; simplicity ; consistency ; uniformity of abbreviation.

5. What may be called the slip-system of notes is recommended.

I1—REFERENCES TO PUBLICATIONS.

§ 2. We have thought it best to make somewhat full references to other
Manuals and Compendiums, and to the Works and Papers of original
observers. Our reasons are :—

1. This work is designed to be used not only by the general student, but
also, as an elementary introduction, by those who are themselves to become
investigators. In our opinion, these latter cannot too soon become familiar
with the sources of original information, and with the views of the present
and past leaders in scientific progress.

2 INTRODUCTION.

2. Upon some points, especially that of Terminology, we feel that the
acceptance of our ideas will be more ready and complete if it be shown that
they are shared by other and more widely known writers.

3. While we are responsible for whatever may prove to be erroneous, we
are very loth to run the risk of receiving, even from beginners, credit for
having first made an observation or -an experiment, or first devised an
instrument or a mode of manipulation, the honor of which belongs properly
to others.

4, On the other hand, since our statements as to the structure of the cat
do not always accord with those of other writers, our own papers are fre-
quently referred to in evidence that those statements have already been
submitted to competent scientific tribunals.

§ 3. References.—In the text, the capital letter or Arabic numeral
directly following an author’s name indicates the place of the work or. paper
upon the List. This letter or numeral is in black letter.

The second Arabic numeral designates the number of the page. When
the introductory portions of a book are separately paged the Roman numeral
designating the page is preceded by the letter p.

When a work consists of two or more yolumes, the number of the volume
in question is indicated by a Roman numeral placed between the two Arabic
numerals.

When two or more works or papers are referred to after the name of the
same author, their letters or numbers are separated by a semicolon.

The numbers of two or more pages or volumes are separated by commas,
or by short dashes when the passages in question extend over several pages.
_ For example: Rolleston, A, 10, refers to the tenth page in the body of
the work of the ‘‘ Forms of Animal Life.” Rolleston, A, p. x, refers to the
tenth page of the Introductory portion of the same work. Agassiz, A, iv,
10, refers to the tenth page of the fourth volume of the “Contributions to
the Nat. Hist. of the U.S.” Wyman, 34, 10, refers to the tenth page of the
** Anatomy of the Nervous System of Pana pipiens,’ which was published
among the ‘‘ Smithsonian Contributions to Knowledge,” and is hence
regarded as a paper.

On account of the large number of citations, we have usually omitted the words
volume and page and their abbreviations. This is regarded as permissible by Bigelow ;
A, 49.

The following is the mode of reference :—

Near the end of the book is a “ List of Publications referred to.” In
that list, fhe names of Authors occur in alphabetical order.

Under each name, the titles are in two groups, including respectively
Separate Books, and Papers published in Journals or by Scientific Societies.

DESIGNATION OF TEMPERATURES. 3

The works are designated by letters, the papers by Arabic numerals. The
former have no definite order, and no significance is to be attached to their
sequence.

The papers are numbered, so far as possible, as in the “Catalogue of
Scientific Papers” published by the Royal Society of London (A), where
the order is intended to be chronological. The eight volumes of that
Catalogue already published include the papers which have appeared between
the years 1800 and 1873. On our list, the papers issued since the latter
date are assigned provisional numbers in italics.

In the case of papers, as in the Royal Society Catalogue “when possible,
both the volume and the year have been given. With Transactions of
Societies the year to which the volume belongs, and not the year of
publication, has been given. A date enclosed in brackets marks the time
when a paper was read, which occasionally precedes by some years the date
of the volume in which it is printed.”

We shall be thankful for corrections or suggestions which may make the Bibliography
more extensive and accurate.

Il.—THE DECIMAL SYSTEMS.

§ 4. The two decimal systems used in scientific work are :—

1. The measurement of Temperature upon the centigrade scale by the
thermometer of Celsius.

2. The metric system of Weights and Measures.

THE CENTIGRADE THERMOMETER.

§ 5. Upon this, the Thermometer of Celsius, 0 (zero) represents the
temperature of melting ice. The point attained by the column of Mercury
at the temperature of boiling water is marked 100 (one hundred).

Between these two — the scale is divided into 100 degrees in groups
of 10 each.

According to this soit the average temperature of the human body is
between 37 and 38, and that of the comfortable atmosphere of a sitting-
room in winter about 20.

Fahrenheit’s Thermometer.—Upon this, the melting point of i ice is
marked 32, and the boiling point of water 212.

§$ 6. Comparison and Reduction of the two Scales.—Since the
Fahrenheit thermometer is largely used in English-speaking countries, the
following Table and Formule may be useful. The former is taken from
Littré et Robin, (A, 1594, Article ‘‘Thermometre”); the latter ay
Dunglison, (A, 488, Article ‘‘ Heat ”).

4 INTRODUCTION.

TABLE

OF SOME EQUIVALENT TEMPERATURES ACCORDING TO THE THERMOMETRIC
SCALES OF CELSIUS (CENTIGRADE) AND FAHRENHEIT.

C. F.
0 32

10 50
20 68
30 86
35 95
[37.24] [99]
40 104
50 122
60 140
70 158
80 176
90 194

100 212

Formule for the reduction of the Fahrenheit to the centigrade scale,
and vice versa.

To reduce F. to C., subtract 32, multiply by 5, and divide by 9. To
reduce C. to F., multiply by 9, divide by 5, and add 32.

1C. equals 1.8 F. 1 F. equals .555 C.

THE METRIC SYSTEM.

§ 7%. Definition.—The Metric System of Weights and Measures is based
upon the meter as a standard of length.

The Meter.—This, the unit of /ength, equals, approximately, one ¢en-
millionth part of the quadrant of the meridian circle which passes through
Dunkirk and Barcelona ; it is thus about one forty-millionth part of the
earth’s circumference as measured upon that line.

In common English measure, the meter is 39.37079 inches, or about
3 feet 3 inches and a third, or about three and one third inches more than
a yard.

The Liter.—This is the unit of capacity. It represents the space
occupied by a cube whose edge is one tenth of a meter.

The liter corresponds nearly to our quart; more accurately, it is 1.056
common quart; 0.880 imperial quart ; 0.907 dry quart.

The Gram —This is the unit of weight. It represents the weight of a
eube of distilled water whose edge is one hundredth of a meter, and at a
temperature of 4° C.

~

THE METRIC SYSTEM. 9)

The gram is 15.432 Troy grains; or 0.564 avyoirdupois drams ; or 0.035
avoirdupois ounces.. The U. 8S. nickel five-cent piece weighs five grams, and
is, moreover, one fiftieth of a meter (2 cm.) in diameter,

The other measures of length, capacity, and weight are decimal divisions
or multiples of the meter, the liter, and the gram, and their names are so
formed as to indicate their value in each case.

§ 8. As compared with the English or any other system of weights and
measures, the Metric System has the following desirable features :—

1. It has a single basis, and involves fewer separate terms ; hence it is

more easily learned.

2. It is decimal ; hence it is more easily used.

3. It is already practically international, and largely, if. not chiefly,
employed in the best kinds of scientific work.

We do not feel called upon for a general discussion of the merits of. the Metric
System. Its origin, nature, and advantages haye been admirably set forth in the works of
F. A. P. Barnard, J. Pickering Putnam, Persifor Frazer, etc., and are periodically urged
by able writers in various Journals, medical, scientific, and sociological. Philosophical
treatises upon the general subject are published by “The American Metrological Society,”
and “The American Metric Bureau” prints a “Bulletin” (A). The final issue of “The
Harvard Register ” contains a compact and at the same time comprehensive plea ‘‘In
favor of the Metric System,” the force of which is rather increased than diminished by the
article just following it upon the opposite side.

Practically, out of the twenty-three or four names for measures of length, capacity,
and weight which may be employed, only about one-third are in common use by scientific
men. These are, the meter, liter, and gram; the centimeter and millimeter, being
respectively the hundredth and the thousandth of the meter; the milligram, the thou-
sandth of the gram; the kilogram or thousand grams; and the cubic centimeter, which is
the same as milliliter, the thousandth part of the liter.

§ 9. The following Table includes all the regular metric denominations.
But only the eight or nine whose names are printed in genitals -& are in
general use.

TABLE OF THE METRIC MEASURES.

LENGTH. WEIGHT. CAPACITY.
| MILLIMETER. MILLIGRAM. Milliliter. Thousandths.
(CUBIC CENTIMETER.)
DIVISIONS. || CENTIMETER. | Centigram. Centiliter. Hundredths.
|| Decimeter. Decigram. ‘Deciliter. Tenths.
UNITS. METER. GRAM. LITER.
if Dekameter. Dekagram. Dekaliter. Tens.
Hektometer. Hektogram. Hektoliter. Hundreds.
MULTIPLES. othe
KILOMETER. KILOGRAM. Kiloliter. Thousands.
[ Myriometer. Myriogram. Myrioliter. Zen thous.

INTRODUCTION.

oO

§ 10. How to Learn the Metric System.—<According to our expe-
rience, there are three chief requisites :—

$11. 1. Absolute certainty of the significance of gram, liter and meter,
as the units of measure of weight, capacity and length, respectively.

With the child or unlearned person, this may be purely an effort of memory. But
most persons can save something by connecting gram with gravity, liter with liguid, and
meter with measure, or with the word itself as it occurs in thermometer, barometer, etc.

§ 12. 2. Certainty of the force of the prefixes.

With the child, this too is a matter of memory. But the prefixes of the names of the
divisions are from the Latin, while those of the multiples are from the Greek. Since Greei
increases while Latin diminishes, it has been proposed to combine the initials of the four
words in a single mnemonic word gild. We suggest, instead, that the gr. of Greek be asso-
ciated with the same letters in greater, and that Latin and less have the same initial.

Deci, centi, and mille are familiar to most persons in the words decimate, centipede
and millipede, while deka, hekto and kilo, are known to some in decade, decalogue, heka-
tomb, and chiliad. Of these six prefixes, however, centi, milli and kilo, are much more
often used than the others.

§ 13. 3. Personal familiarity with some metric measure.

The shortest and surest way to a knowledge of the metric system is to carry some
metric measure, or have one always at hand. The five-cent nickel piece is 2 centimeters
in diameter. and weighs 5 grams. The student is advised to carry a metric rule in the
pocket, and to keep another always upon the table.

The prices of Rules and Tapes vary from 3 cents to as many dollars. A list of the
styles and prices may be obtained from the American Metric Bureau (A), and from dealers
in such articles,

Fie. 1.

Fic. 1. A section, about one tenth, of the paper meter-yard, furnished for 20 cents
by the American Metric Bureau (A, No. 26, 410). The face has the meter and the yard
side by side, and the back bears a complete Table of metric and English equivalents,
embracing 198 separate entries. The whole folds into the length of a decimeter, so as to
be easily carried in the pocket, and the Table may be consulted without unfolding the
paper, ‘‘ Moisture affects the absolute length, but not the accuracy of comparison.”

METRIC EQUIVALENTS. Y

Teachers may aid the introduction of the system by obtaining metric Models and
Apparatus, by hanging metric Charts upon the walls, by making their own diagrams on
cloth a yard wide but a meter long, and by pointing to them with the graduated Sticks
of one or two meters in length. But the best of all agencies is the placing of some metric
measure, if only the 5-cent rule, in the hands of each pupil.

An efficacious yet inexpensive way of diffusing elementary information and arousing
curiosity respecting the system is to employ, in business correspondence, envelopes or
postal cards bearing a metric ruling along one edge. This ruling is done free of charge
by the Metric Bureau. - f

§ 14. Reduction to and from the Present System.—Pending the
universal adoption of the metric system, it is often necessary to effect a
reduction to and from the older measures.

The following Table of Equivalents is selected from the Tables on the
back of the ‘‘ meter-yard,” (Am. Met. Bureau, A, 444-448), in Foster and
Langley, (A, 263), and in Egleston, (A).

Abbreviations. Measures. Accurate. Approximate.
cm. centimeter. 0.393 in. A in.
c. ¢., OF cu. cm, cubic centimeter. 0.033 fi. oz. 03 fl. oz
fl. oz. fluid ounce. 29.578 c. c. 30. GG
ft. foot. 0.304 meter. 23 m.
ft. ss 30.479 em. 300 cm
U.S. gall. U.S. wine gallon. 3.785 liters. 3.8 1
U. S. gill. U. 8. wine gill. 118.31 c. c. 118 ce
gr. Troy. Troy grain, .064 gram. 06 ¢
g. gram. 15.432 gr. Troy. 15.5 gr.
¢ t6 0.564 dram avoir. 6 dr. ay.
<7 rhe 0.035 oz. avoir. 03 oz. av
in. inch, 2.539 cm. 2.5 cm.
kilo., or kg. kilogram. 2.204 lb. avoir. 2.2 Ib. av.
. oe as 2.679 lb. Troy. 2.7 Ib. Troy.
: . $e 82.15 oz. Troy. 32 - oz. Troy.
v9 ts 35.27 oz. avoir. 35 Oz, av
km kilometer. 0.621 mile. .6 m.
1. liter, 0.264 U.S. gall. .25 gall.
‘ £ 1.056 U. 8. quarts. 1 qt.
ts . ' 2.113 U.S. pints. 2.1 _ pt.
m. meter. 0.546 fathom. 5 fath.
" ee 1.093 yard. 1.1 yd.
“ ss 9.842 hands. 10. ~=hd.
ed Re 3.280 feet. 3.3 ft. .
¥ “ 39.370 inches. 39.4) in.
mile. mile. . 1.609 kilometers. 1.6 km.
mm. millimeter. 0.039 inch. .04 in. ©
7 “ micromillimeter.” 0.001 mm. 0.000089 in
-00004
oz. avoir. ounce avoirdupois. 28.349 grams. 28.35 g.
oz. Troy ounce Troy. 81.103 g. 31 g.
U.S. pt. U. S. pint. 0.473 liter. bey 5
Ib, avoir. pound avoir. 0.453 kilo. 45 kg.
lb. Troy. pound Troy. 0.373 kilo. 37 kg.
U.S. qt U.S. quart. 0.946 liter. 95 1.
yd. ‘yard. 0.914 meter. “9 ™m.

8 INTRODUCTION.

The “micromillimeter” is not an original member of the Metric System, and the
desirability of using the word is strongly questioned. In either case, the symbol for the
thousandth of the millimeter should be the Greek y rather than mmm.

§15. The Metric System in Medicine.—Notwithstanding the
obvious and considerable hindrances to a change involving commercial inter-
ests, the new system is surely though slowly making its way among Physicians
and Pharmacists.

The matter is constantly discussed in the Medical Journals, and “ Reduction Tables ”
have been publisbed in very compact form. Dr. Kreider has one, in the Medical Record
for Oct. 23, 1880; Dr. F. H. Brown has another in “ The Medical Register for New Eng-
land,” which has been reprinted as a pocket leaflet by the Metric Bureau ; while another
leaflet, first printed by the Metric Bureau (A, 345-348), by Dr. E. Wigglesworth, presents
“The Metric System in a Nut-shell,” with especial reference to the needs of the
medical profession.

ZOOLOGICAL CLASSIFICATION.

§ 16. As this isin no sense a treatise upon either Zoology or Com-
parative Anatomy, but simply a guide to certain practical methods of work,
we give only such an outline of the Classification of Animals as may serve to
indicate the generally accepted taxonomic relations of the forms here con-
sidered.

Fuller information and discussion of this matter may be found in the works and
papers of Gegenbaur, Heckel, Huxley, Owen, etc.,and in the condensed Summary of
Pascoe (A) ; see also Balfour, A, ii, 1.

It did not seem worth while, in the accompanying Table, to indicate the view enter-
tained by many Zoologists, that the primary division of both the Animal Kingdom and
the Vertebrate Branch is dichotomous: the one into the Protozoa and the Metazoa; the
other into the Acrania and the Craniota.

The names of the eight animals more or less fully treated of are given in
the column at the right of the page. One, the ameba, isa member of the
lowest division of the Animal Kingdom, the Protozoa, and consists of but a
Single cell, a mass of nearly homogeneous but nucleated protoplasm.

The other seven belong to the highest division, the branch Vertebrata,
the essential character of which, as will be more fully indicated farther on,
is that there is a dorsal and a ventral cavity, between which is a sub-cylin-
drical axis of membrane, cartilage, or bone.

Man, the Cat, Dog, and Rabbit are members of the class Mammalia,
including the Vertebrates which are warm-blooded, and are brought forth
alive. The Frog and Menobranchus are Amphibia or Batrachians, which
differ from the Reptiles in having gills or water-breathing organs at some
period of their lives.

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‘pgouy * * j F (‘STVNINY UVINTIAOINQ) VOZOLOUd J
‘ST IdNVX4 ‘SaSSV19 ‘SUHONVUG

10 ‘ INTRODUCTION.

The lowest vertebrate is the little Amphiorus lanceolatus, usually assigned
to a distinct class, the Acrania. Between the Amphioxus and the Amphibia
are all the ‘‘ fishes,” common and uncommon, including the Sharks and
Rays, and many for which there are no popular names, Likewise, between
the Amphibia and the Mammals are the classes Reptiles and Birds, no exam-
ples of which are herein considered.

IV.—TERMINOLOGY.

; § 22. Whoever does any systematic practical work in anatomy, whether by investi-
gation or teaching, is impelled, sooner or later, to suggest some modifications of the lan-
guage previously employed in recording or communicating observations and ideas.

Such modifications are often put forth in publications without explanation or apology,
and their subsequent adoption by others may then depend less upon their intrinsic value,
than upon the reputation and authority of the proposers, .

In the following pages, especially in the account of the Brain, there will be found a
few new words, for the introduction of which reasons will be duly offered.

Many other words and phrases will appear more or less unusual, some to one reader
and some to another. Those, however, who are most familiar with the best original
anatomical publications in not only their own language, but also those of other nations,
wil, upon careful scrutiny, perceive that the present work really contains very few terms
for which there is not sound precedent in the writings of recognized authorities, in the
use of either the same words, or of words analogous in character and formation.

From the productions of working anatomists in all parts of the world we have
endeavored to select, without bias or partiality, the terms which seem to us best suited to
the object, and most easily used.

As a whole, therefore, the Terminology here employed is that of no one nation or
writer. Much less should it be regarded as our own, excepting in so far as we have
succeeded in our efforts to combine the elements from various sources into a consistent and
homogeneous whole.

But while the prestige of authoritative precedent might lead us to make a personal
trial of any assemblage of terms, it would not, by itself, warrant an introduction into a
purely elementary work like the present. It is proper, therefore, to say that, with very
few exceptions, all of the names and descriptive terms here employed have withstood
the severe practical test of use by a large number of students for from one to seven
years.

This test is called severe because these students have been comparatively mature,
and have done practical work in anatomy with the view of becoming either naturalists,
teachers or physicians; and because they have not simply listened to lectures in which
the terms were used, but have been required to employ them in writing their own de-
scriptions of parts; because, finally, they have been urged to make suggestions and criti-
cisms with entire freedom.

On what, therefore, may be called experimental grounds, we feel justified in present-
ing this Revised Terminology of Anatomy to students other than our own; but since
each year has brought about some change therein, we have no reason to think it perfect
or complete, and we ask the co-operation of all who may undertake to follow out our
directions with the view of rendering it better adapted to the needs of Practical Workers
in Anatomy.

ANATOMICAL TERMINOLOGY. 11

§ 23. Some General Considerations upon Anatomical Terminology.—These
remarks are based largely upon an article (Wilder, 9), which although published under
the name of the senior author, was prepared with the advice and co-vperation of the
junior.

That article referred more particularly to the brain, but covered most of the questions
connected with the naming and description of other parts. Hence the following expres-
sions, the only published comments which have come under our notice, may fairly be
considered applicable to the whole subject :—

‘‘The Nation” for April 21, 1881, contains. a brief notice of the article, evidently by
an experienced teacher of Anatomy, containing the admission that “there is certainly
ample room for a Reform of Anatomical Nomenclature.”

The following are extracts from a Letter (Spitzka, 7) to the editor of “ Science,” pub-
lished in that journa] for April 9, 1881, by Dr. E. C. Spitzka, the author of many papers
upon the Anatomy of the Brain :—

‘*It is with mingled pleasure and profit that I have read the very suggestive paper on
cerebral nomenclature contributed to your latest issues by Professor Wilder. Some of
the suggestions which he has made have been latent in my own mind for years, but I have
lacked the courage to bring them before my coHeagues. Now that he has broken ground,
those who prefer a rational nomenclature to one which, like the present reigning one, is
based upon erroneous principles, or rather on no principles at all, will be rejoiced at the
precedent thus set for innovations. * * * He who has himself been compelled to labor ~
under the curse of the old system, the beneath, belaw, under, in front of, inside, external,
between, etc., will look upon the simple ventra/, dorsal, lateral, mesal, cephalic, proximal,
caudal, distal, etc., a8 so many boons. I have no hesitation in saying that the labor of
the anatomical student will be diminished fully one-half when this nomenclature shall
have been definitely adopted. * * *

In proceeding to comment on some of the terms proposed by Professor Wilder, I
wish it to be distinctly understood that I do so merely tentatively and to promote
discussion ; in so doing I feel certain that I am carrying out that writer’s wish. It is
but just to state that the majority of the terms cannot be discussed ; they are perfection
and simplicity combined.”

With the permission of the writer, “Science” for May 28, 1881, printed the following
Letter (Holmes, 1), from one who has been the Professor of Anatomy in the Harvard
Medical School for more than the third of century :—

“ Boston, May 3, 1881.

“DEAR Dr. WILDER:—I have read carefully your paper on Nomenclature. I
entirely approve of it as an attempt, an attempt which I hope will be partially successful,
for no such sweeping change is, I think, ever adopted as a whole. But I am struck with
the reasonableness of the system of changes you propose, and the fitness of many of the
special terms you have suggested.

“The last thing an old teacher wants is, as you know full well, a new set of terms for
a familiar set of objects. It is hard instructing ancient canine individuals in new devices.
It is hard teaching old professors new tricks. So my approbation of your attempt is a sic
vos non vobis case so far as I am concerned. * * *

“ What you have to do is to keep agitating the subject, to go on training your
students to the new terms—some of which you or others will doubtless see reasons for
changing—to improve as far as possible, fill up blanks, perhaps get up a small manual in
which the new terms shall be practically applied, and have faith that sooner or later the
best part of your innovations will find their way into scientific use. The plan is an ex-

12 INTRODUCTION.

cellent one; it isa new garmeat which will fit Science well, if that capricious and fantastic
and old-fashioned dressing lady can only be induced to try it on.
“Always very truly yours, ,
‘““OLIVER WENDELL HOoLMEs.”

See also Appendix, § 1443.

That Terminology is worthy of attention, is indicated also by the care
bestowed upon the language of modern Chemistry and Mathematics, and by
the following Aphorisms :—

§ 24. “Questions of Definition are of the very highest importance in
Philosophy, and they need to be watched accordingly.”—Duke of Argyll, 1.

**Tn all sciences, Nomenclature is an object of importance; and each
term should convey to the student a definite meaning.”—Dunglison, A,
Preface. .

“ Every art is full of conceptions, which are peculiar to itself; and, as
the use of language is to convey our conceptions to one another, language
must supply signs for those conceptions.” —Hualey, C, 14.

‘“‘Everything in Science ought to be real, ingenuous and open; every
expression that indicates duplicity, or equivocation, reservation, wavering or
inconsistency, is a reproach to it.”—Barclay, A., 89.

“There is a necessity for perfect definiteness of language in all truly
Scientific work.”—P. G. Tait, 1.

“Technical terms are the tools of thought.” *

**Only an inferior hand persists in toiling with a clumsy instrument,
when a better one lies within his reach. * * * A single substantive term
is a better instrument of thought than a paraphrase.”—Owen, A, I, pp.
xii, Xiv.

“* As morphology deals with forms and relations of position, it demands
a careful selection of terms and a methodical nomenclature.”—(Goodsir, A,
I, 83.

‘To designate the locations of organs by the relation of animals to the
surface of the earth is as far from philosophical as it would be to define the
position of a house or of a tree by reference to the planet Jupiter.”— Wilder,
9, 122.

The progress of Comparative Anatomy has been hindered by the use of
anthropotomical terms and methods.

‘* There is not one person in a hundred who can describe the commonest
occurrence with even an approach to accuracy.” — Huzley, C.

**The test of the accuracy and completeness of a description is, not that
it may assist, but that it cannot mislead.”— Wilder, 9, 123.

Errors of personal equation are diminished by the use of exact terms.

* Perhaps some of our readers can supply the source of this aphorism.

METHODS OF TERMINOLOGICAL CHANGE. 13

“ A name is a short substitute for a ‘definition, and where no definition
exists, there can be no name.”—Packard and Cope, 1.

‘«The one essential of naming is that distinct objects shall have distinct
names; and the second essential is, that each object or concept shall have
but one name.”—Jdem.

‘‘ Life is too short to spend in digging for Truth with a long-handled
shovel when a trowel will serve the purpose; nor is it becoming that any
nation, however wise and great, should ask all the rest to take their intel-
lectual food with chop-sticks of its peculiar pattern.”— Wilder, 9, 124.

‘The personal convenience and preferences of all existing anatomists
should be held as of little moment as compared with the advantages which
reform may ensure to the vastly more numerous anatomical workers of the
future.” —Jdem, 137.

The two following may serve to show that we have not been unmindful of the
dangers and disadvantages of terminological change.

** Nothing is more pernicious than to auigieizy to tamper with well-
understood and universally accepted symbols.” — Anonymous Reviewer (‘‘ The
Atheneum,” June 4, 1881).

**He who, affected by the cacoethes reformandi, insists upon reform for
the sake of an ideal perfection, is apt to appear as nothing better than a
troublesome and useless pedant.”— Wilder, 9, 124.

§ 25. Brief Statement of the Objects and Methods of the
Terminological Changes here made.—To render the Vocabulary of
Anatomy equally applicable to all Vertebrates, and equally intelligible to all
Nations.

To facilitate the Recognition of parts by students, and lessen the labor
of Memorizing.

To abridge the length of Descriptions, and at the same time increase
their Accuracy.

To include in this Vocabulary, so far as practicable, only such terms as are
brief, simple, exact, significant, of classical origin, and capable of inflection.

To propose as few changes as possible, and to introduce new names only
for parts apparently unknown or unnamed before (e. g., crista fornicis), or
in the place of semi-descriptive appellations undesirably long or incapable
of inflection, as e.g., cimbia for tractus transversus pedunculi, porta for
foramen Monrot.

To consider brevity as an especially desirable characteristic of such names
as are most frequently employed.

When a part is known bya descriptive phrase, to select therefrom some
characteristic word as the technical designation; ¢. g., iter (a tertio ad
ventriculum quartum).

14 | INTRODUCTION. -

When two or more parts are similar, or have similar relations, to distin-
guish them by joining to some common title already in use, prefixes indica-
tive of their relative positions ; e¢. g., postgeniculatum, pregeniculatum, -:

To shorten the names of several parts by omitting the word corpus, and
using the neuter adjective as a substantive.

To keep modern usage and the rules of classical etymology constantly in
mind, but not to be hindered thereby from the employment or even the
formation of terms which are eminently desirable from the practical stand-
point.

To discard terms which indicate size, those which refer to the natural
attitude of man or animals, most vernacular names, and all names of the
reproductive organs which have been applied needlessly to other parts.

The terms employed by anatomists form two divisions: those which indi-
cate the position or direction of organs, and those by which the organs them-
selves are designated. Since, also, writers have often treated of them sepa-
rately, it will be convenient here to consider anatomical toponomy and
organonomy under distinct headings.

§ 26. Designation of Organs—Organonymy.—There are probably
few investigators or teachers of comparative anatomy who have not been
impressed, in some degree, with the desirability of some modification of the
prevailing nomenclature of organs,—the ‘“‘ bizarre nomenclature of anthro-
potomy,” (Owen, A, II, 143)—based as it is upon the peculiar features of
the human body, which has been fitly characterized, from a morphological
point of view, as “‘not a model, but a monstrosity.”

This impression may give rise to special papers, like those of Owen, (166),
Maclise (7), and Pye-Smith (7), or simply to more or less extended remarks
upon the subject, with or without the use or presentation of new terms.

More than one hundred pages of Vicq d’Azyr’s great Anatomy (A) are
devoted to a ‘‘ Vocabulaire anatomique, augmente d’un grand nombre de
termes nouveaux.”

In the Preface to his “‘ Anatomie du Chat” (A, pp. xiv—xvii), Straus-
Durckheim devotes several pages to a discussion of anatomical nomenclature,
and the body of the work contains many original names. Professor
H. §. Williams calls attention (A, Preface), to the ‘‘crying need of a stand-
ard and uniform nomenclature of comparative anatomy.”

In the Preface to their recent account of the morphology of the skull
(A), Parker and Bettany say: ‘‘It has been attempted to narrate the facts
by means of a consistent terminology, amplifying what Prof. Huxley has so
admirably developed.” Several of Huxley’s papers (as 70), contain new
terms, most of which have been generally accepted, and in a greater or less
degree the same is true of the elder Agassiz (A), Gegenbaur (59), Heckel
(A), Marsh (7), and others.

IMPORTANCE OF BREVITY. 15

§ 27. Nomina Impudica.—Several parts, especially of the brain, have
received names originally applied to portions of the reproductive apparatus
which they were fancied to resemble. While it may perhaps be urged in
extenuation that the patres anatomici entertained a notion as to the representa-
tion of the entire organism in the brain, some of their terms certainly indicate
an entire freedom from apprehension that the mysteries of encephalic
anatomy ever would be discussed by ordinary mortals, much less by women,
or under circumstances requiring propriety of speech.

On the other hand, many names of general or special application tive
been, at times or by certain writers, needlessly applied to the male and
female organs. Among the 50-60 medical synonyms for vulva are sinus,
folliculus, annulus, hiatus, ostium, sulcus, trema, delta, cava, fovea, mesa,
porta, and fundus. Among the 70-80 synonyms of penis are vomer, vas,
clavus, cauda, vena, gladius, radix, ramus, columna, trabs, pyramis, and
spina. These terms should not be lost to clean anatomical uses because
heedless or filthy-minded writers have so misapplied them.

§ 28. Importance of Brevity.—As has been stated, and as will be
exemplified in the vocabulary, we place great stress upon brevity as a desira-
ble characteristic of anatomical terms.

So Jong as the study of anatomy was nearly confined to members of the
medical profession, they being comparatively few in number, and, by ancient
tradition at least, not wholly averse to clothing their discourse in a
sesquipedalian garb impenetrable to the vulgar eye, it mattered little whether
the statement of a given fact or idea required one minute or five.

But now, thanks to the popular writings of Agassiz, Dana, Gray, Darwin,
Heckel, Huxley, Owen and others, in so far especially as they have aroused
a personal interest in the problems of Evolution, natural history instruction
is given systematically in all schools and colleges, and the time seems to have
come when, in the words of the naturalist first-named, ‘‘ Scientific truth
must cease to be the property of the few; it must be woven into the common
life of the world.” It is probable, indeed, that those who employ anatomical
language to a greater or less extent at the present day are at least one hun-
dred times as numerous as when Dr. Barclay’s praiseworthy effort at reform
was received with indifference or opposition.

In our opinion, therefore, the single names trochiter, trochin, epicondylus, and epitroch-
lea are worthy of aloption in place of the compound terms greater and lesser tuberosity,
external and internal condyle of the humerus, notwithstanding their proposer, Chaussier,
has burdened the myological division of anatomy with the most unwieldly set of terms
that could have copia devised.

§ 29. Technical Terms.—It may be asked: In the face of this rapid
popularization of anatomical knowledge, is it worth while to introduce, or
even to retain, any purely technical terms ? FEN

16 INTRODUCTION.

Apparently some German scientists have determined upon a negative
reply to this inquiry, and their papers, even those of strictly scientific
nature, teem with vernacular words, and with wonderful compounds
thereof.

For abundant examples, the reader may consult any “ Dictionary of
German Medical Terms,” as that of Cutter (A).

If this kind of verbifaction be tolerable under any circumstances, it cer-
tainly would be justified by the extent and importance of the contributions
to knowledge which appear first in the German scientific periodicals.

Upon this point, however, we can do no better than to quote the very
recent judgment of one who is at the same time an investigator, a promoter
of “the diffusion of knowledge,” and an admirer of the methods and results
of German science : —

“Every art is full of conceptions which are peculiar to itself; and, as the use of lan-
guage is to convey our conceptions to one another, language must supply signs for those
conceptions. Either existing signs may be combined in loose and cumbrous paraphrases,
or new signs, having a well-understood and definite signification, may be invented.
Science is cosmopolitan, and the difficulties of the study of zoology would be prodigiously
increased if zoologists of different nationalities used different technical terms for the same
thing. They need a universal language; and it has been found convenient that the
language shall be Latin in form, and Latin or Greek in derivation.” —Hualey, C, 14.

Unless it can be shown that there is a distinction between the methods
of designating entire organisms, and the parts thereof, the foregoing passages
should silence the objections of those who would have us retain a vocabulary
as vague as was that of Chemistry in the days of quicksilver, vitriol and
copperas—a vocabulary which combines the ponderous stiffness of the clois-
ter with the puerile vagueness of the nursery. Tuberculum bigeminum
anterius must give way to lobi optici, or some even shorter term; while
trachea must take the place of windpipe, weasand, luftrihre and conduit
@rien.

Is it not worth considering, too, that any avoidance of the use of technical
terms is, after all, only partial and delusive? The principal human organs
have, of course, received popular names which may, in great measure, be
applied to the other Vertebrates, especially the Mammals. But there are
many other organs of which the butcher takes little or no account. Shall
we construct vernacular phrases, and write of the liver-vein, the kidney-
artery, the gullet-nerves, and the sweetbread-tube? Unless we are prepared
to give up such convenient and elastic terms as hepatic, renal, pancreatic,
pulmonary, cardiac, etc., why should not the student be informed, at the
outset of his anatomical and physiological enquiry, that nearly all the divi-
sions and appendages of the principal organs have received titles derived from
the classical names of the organs themselves? These derivatives and com-

TECHNICAL TERMS. 17

pounds ould then have some significance, instead of appearing like trouble-
some verbal complications.

So too with the names of the various groups of achat: nearly all of which
are based upon the technical names for some of the organs. The determined
‘‘vernacularist ” may delude himself with the belief that he is defying the
classics in calling Amphiorus by the name Lancelet ; but he cannot appre-
ciate the progress or the present condition of systematic zoology without
learning that to the same lowest vertebrate have been applied the terms
acrania, leptocardia, cirrostomt, cephalochorda, and pharynyobranchii. Why
then should he not have been informed already that cardia, cirrus, stoma,
pharynx and branchia are technical names for heart, gill, ete. ?

In short, while the small beginnings of Physiology and Zoology may be ac-
quired by the use of vernacular words alone, any considerable progress in exact
knowledge would be excessively inconvenient if not impossible, at least with
the French or English student, without the aid of a certain number of tech-
nical terms.

Nor are these terms so numerous as to constitute anything more than a
purely sentimental burden. As has been well-said by one who is in the
position to recognize to the full the value of purely classical training, “A
doctor, lawyer, or popular exhorter who cannot learn by heart, in a week,
all the technical terms and phrases of Latin origin which he encounters in
his common professional occupation, has not wits enough for his calling.”
Eliot, 7, 359.

That there is no inherent obstacle to the employment of technical terms
of classical derivation is shown by the readiness with which such words. as
petroleum and phylloxera have become domesticated along with the objects
which they represent. There are scores of animals, like the Rhinoceros,
Hippopotamus, and Ichneumon, for which there are no English vernacular
names ; while the youngest student of Botany accepts Hepatica, Anemone,
and even hododendron without difficulty or hesitation. Homely as itsounds,
stomach is of classical origin, and the use of caul for omentum, sweet-bread
for pancreas, or blind-gut for cecum, would surprise a class in Elementary
Physiology.

Even the late Jeffries Wyman, who saw no objection to forearm, and
used near rather than proximal for the first row of carpalia, accepted inter-
membral as “ good,” and freely employed, if indeed he did not originate, the
adjective pretibial, which probably would have come into general use had
not the bone in question proved to be the homologue of the intermedium.—
(Morse, 78, 13.) '

§ 30. Names Indicative of Relative Position.— Where four or more
similar parts form a series, they are usually numbered 1, 2, 3, 4, etc., begin-
ning with the one nearest the head, or the middle line, as the case may be.
Thus, of the ribs, the first is next to the neck; among the several groups of

2

18 ‘ INTRODUCTION.

vertebrae, cervical, thoracic, and lumbar, the most cephalic is the first ; so
too, in the normal position of the limbs (to be explained farther on), the
pollex and primus (great toe) are on the borders nearer the head, and may
sometimes be designated as the first digit and dactyl.

In designating the fractional portions of the length of a bone, the
proximal half, third, fourth, fifth, etc., is the first ; the rest following in
order toward the distal end.

When, however, the series embraces only two or three similar parts, the
general name for them all has been usually followed (in Latin) or preceded
(in English) by some word indicative of relative position; as, e. g., processus
superior, and middle commissure.

This plan effects a saving in the number of different words without the
risk of ambiguity, just as when we say John Smith senior, junior, and third.
But all such terms are open to the objection of being compound, and there-
fore incapable of inflection.

In some cases, therefore, the more general terms have been combined
with the distinctive prefixes to form single words, like swpraspinatus and
mesogluteus. Owen has also employed (A, III, 519) postcava and precava
and the senior author has proposed (22, 306) entopectoralis and ectopectoralis,
and, more recently (9 and 77), a series of similar names for parts of the
brain; e. g., precommissura, medicommissura, postcommissura, ete.

§ 31. The Limits of Terminological Change.—As has been stated
already, the modifications here proposed are intended to provide for what seem
to be actual necessities, irrespective of purely theoretical considerations, and
of any desire for a perfectly uniform and consistent terminology. It may be
well, however, to specify certain general limitations to changes of anatomical
nomenclature.

Priority is practically of little moment in respect to the names of organs,
since it is usually difficult to ascertain when and by whom they were first
applied. An example of this is afforded by the phrase foramen of Monro,
(Wilder, 3). Nor, indeed, has priority always been held sacred in systematic
zoology. Owen’s ‘‘Deinosaurians” was proposed nine years later than von
Meyer’s *‘ Pachypoda;” yet, as stated by Huxley (108, 33), it has been
retained, notwithstanding the small size of some members of the group.

Etymological appropriateness is sometimes disregarded, as in the case
just mentioned, and in the more familiar names Jepéiles, Vertebrates,
Edentates, etc. Prof. Huxley has recently expressed the common sense view
of the matter as follows :—

“Tf well understood terms which have acquired a definite scientific
connotation are to be changed whenever advancing knowledge renders them
etymologically inappropriate, the nomenclature of taxonomy will before long
become hopelessly burdened.” (C, 16.)

So, too, the names of organs have sometimes been given in reference to

ITIMITS OF TERMINOLOGICAL CHANGE. « 19

some variable or unessential character, or have even conveyed an erroneous
idea; yet no one now thinks of discarding either rectum, arteria, or carotid.

Sometimes even brevity and etymological accuracy yield to established
usage. ‘The word cudbitum, proposed by the senior author in 1872 (10, 21)
as the technical equivalent of fore-arm, is both shorter than anéebrachium,
and more in accordance with its classical employment; but the latter word
seems to be more generally preferred, and we are ready to accept it.

In another case, even though a new term has not yet come into general
use, a special vitality may be imparted to it by the authority of those who
may have adopted it. No marked or persistent disfavor is likely to be shown
to terms which, like myelon, can claim Prof. Owen as father, and find a god-
father in Prof. Huxley.

Even Milne-Edwards, while intimating (A, XI, 234) that anatomical
nomenclature has been created in sufficient dace frankly admits the
superiority of myelon over moelle épinicre.

§ 32. Some Inconsistencies.—It will be noted (Fig. 6) that we have
refrained from giving technical names to the membral arthra (joints) or
have merely added them in parentheses.

This is partly because the need of names for parts so familiar seems less
urgent than in the case of some other organs. Still, it is certainly undesir-
able that the carpo-metacarpal arthron should be called wrist in man, and
knee in the horse, and the chief cause of our inconsistency in this respect
has been our inability to decide upon the relative merits of the various
names which might be applied. The names suggested are those which were
proposed by the senior author in 1871 (10, 21-24) ; but they do not appear
to have been adopted to any considerable extent.

Strict logical consistency, also, would impel us to substitute entoscapular
for subscapular in the designation of a fossa and muscle of the scapula; so
too, supraspinous, supraspinatus, infraspinous, and infraspinatus, should
be prespinatus, etc.; notwithstanding’ the demands of consistency and
logic, and the example of Owen (A, III, 44), we decline to interfere with
these brief and old-established titles of well-known parts.

Further information concerning the changes in the names of organs will be given in
the Index and in the Lists and Tables of names in the several chapters.

It will be noted, also, that of the two Latin names for heart we have
adopted the longer cardia, rather than the shorter cor. This is because
derivatives and compounds of the former are by far the more numerous and
familiar. Hence the selection is really in accordance with the more general |
principle that all measures of reform should have regard to the practicability
as well as the abstract suitability of a change.

The case with stomach is less simple; although the word is directly
derived from the Greek ordépayoc, it is practically a vernacular term, while

| To INTRODUCTION.

most of the derivatives and compounds are formed from the Latin gaster.
Perhaps we should have adopted the latter as the technical designation for
the organ.

§ 33. Names and Abbreviations on the Figures.—Whatever may
be the practice of different writers, probably all will agree that figures for the
information of students, and especially such as are to be used in dissection,
are more helpful if the following conditions are observed :—

1. So far as possible, the technical names of the parts should be written
upon the parts themselves.

2. Where there is not room for the names upon the figure itself, they
should generally be written at the side, and connected with the parts by
distinct lines.

3. When abbreviations are employed, they should be of the technical
rather than of the vernacular terms, and should be wniform, at least for all
figures of the same organ or region.

Whoever examines the figures in the present work will see that an
attempt has been made to conform to the above named conditions. That
success has been only partial, will be at once anticipated and excused by all
who have undertaken the same task. The need of abbreviation was greatest
with the brain, where many distinct parts are crowded within a small space.
Here, as a rule, only names of more general application, such as Fissura,
Gyrus, Sulcus, etc., and their abbreviations, have been commenced with
capitals ; but this distinction has not been observed in all other cases.

In the explanations of the figures, the abbreviations are given in alpha-
betical order.

§ 34. Terms of Position and Direction—T oponymy.—Like other
solids, the body of an animal has siz general aspects.

As with other elongated solids, these aspects are two ends and
four sides.

Were the body simply a mass of homogeneous material, like, for
example, an oval of wood, the supporting ‘side would be called the botiom,
and described as the lower side ; the opposite side would then be upper, and
be called fop ; of the two other sides, either might be called right, and the
opposite would then be /eft; finally, either of the two ends might be
named front, and the other end would then be known as back. To indicate
the two ends as anterior and posterior, and the top and bottom as superior
and inferior, would render only more evident the fact that the various
aspects of the mass are determined and named according to their relations
to the observer, or to the surface of the earth.

But with the animal body, at least the body of the adult vertebrate,
there are constant and more or less marked distinctions between the
opposite ends and sides, so that these various aspects have fixed and definite
relations to one another and to certain other objects or influences.

THE NORMAL POSITION. 21

Food and drink are received at one end of the body, and the organs of
special sense are there located. Between one of the sides and the nervous
cord known as the myelon or spinal cord, there always intervenes a subcylin-
drical rod, usually of bone or cartilage, the Columna vertebralis; or spinal
column, while the opposite side is not so separated from the myelon. The
two remaining sides differ less from one another, but distinctions have been
observed, some of which have been commented upon by the senior author
in papers 7.3, 12, 13, and 18.

It is obvious that the comparison of the corresponding aspects in different
animals will be more easily made and more instructive, if the animals can be
placed, actually or ideally, in some common position, and if the aspects can
be called always by the same names.

§ 35. The Normal Position of the Body.—Taking as the natural
attitude of an animal that which it assumes in ordinary locomotion, there
are wide differences among Vertebrates. The head of man points directly
away from the earth, and the longitudinal axis of the body forms a right
angle with its surface ; with the gorilla and some other apes the axis is
slightly inclined ; with birds it forms a smaller angle with the supporting
surface; but with the larger number of vertebrates the body is cigs or
quite horizontal.

As the question is entirely one of bodily organization, and has no refer-
ence to mental or spiritual preeminence, there never has been made any
serious objection to regarding the normal position of vertebrate animals
as that of the majority of them, in which the body avis is horizontal, and
the aspect nearer the earth is that which is separated from the myelon by
the Columna vertebralis.

§ 36. Designation of the Aspects.—Instead, however, of applying
to the various aspects names naturally suggested by the parts themselves,
irrespective of the particular attitude assumed by the animal, anatomists,
probably influenced by the greater practical importance of the human body,
have almost universally employed terms which are strictly applicable only to
man in the erect attitude. In order, therefore, that a comparison might be
instituted between corresponding parts of man, a cat and a fish, it
was necessary, at least constructively, to erect the two latter upon their
tails.

Notwithstanding the logical inconsistency of such a course, and the risk
of misunderstandings, no effort at reformation seems to have been made
until early in the present century, when Dr. Barclay, the anatomical pre-
ceptor of Professor Owen, published a little volume (A) entitled: “‘A New
Anatomical Nomenclature, relating to the Terms which are expressive of
Position and Aspect in the Animal System.”

§ 37. The key note of Barclay’s view of the subject is struck in the
following paragraph :—

22 INTRODUCTION.

“The vague ambiguity of such terms as superior, inferior, anterior, posterior, etc.,
must have been felt and acknowledged by every person the least versant with anatomical
description.”

Some of Barclay’s new terms have been occasionally used by Owen, but
most of his contemporaries and immediate successors seem to have been quite
indifferent to his suggestions, and only within a comparatively few years has
the subject again received attention.

Dunglison admits (A, 61) that “Great confusion has prevailed with
anatomists in the use of the terms before, behind, etc.” Spitzka forcibly
states (7, 75, note 1) the objections to the use of anferior, etc., and refers
(7, 165) to the gradual disuse of the equivalent German terms by Henle,
Gudden and others ; more exact terms, also, are occasionally employed by
several writers who do not explicitly condemn the current toponomy; Coues,
1, 150; Cleland, 7, 170; Gegenbaur, A, 491; Rolleston, B, 33, note;
Huxley, 2.

In previous publications (A, 69, and 7, fere) Mivart more or less consist-
ently discards anterior and posterior, and his recent work (B, 258, note,) cha-
racterizes them as ‘‘ Unfortunate as applied to a quadruped like the cat.”

Finally, the need of a radical ‘‘ change of base” has been proclaimed in
one of the very strongholds of anthropotomy : —

“ Now that the more extended study of comparative anatomy end embryonic develop-
ment is largely applied to the elucidation of the human structure, it is very desirable that
descriptive terms should be sought which may, without ambiguity, indicate position and
relation in the organism at once in man and animals. Such terms as cephalic and caudal,
dorsal and ventral, etc., are of this kind, and ought, whenever this may be done con-
sistently with sufficient clearness of description, to take the place of those which are only

applicable to the peculiar attitude of the human body.”—Quain, A, i, 6.

This is certainly explicit as to the principle involved, and it is to be
hoped that later editions of this standard Human Anatomy may display its
practical application to the body of the work.

The ambiguity here alluded to is not merely hypothetical. In a recent
work (Mivart, B) the Jf. sterno-mastoideus is described (p. 134) as arising
“beneath the anterior part of the pectoralis major,” but on p. 145 a part of
the M. ectopectoralis is said to arise “beneath the manubrium [prester-
num|].” In the former case beneath means entad of or dorsad of, while in the
latter the same word signifies ectad of or ventrad of. The experienced
human or comparative anatomist may know what is intended, and the con-
text would enable any one, with a little study, to determine the matter by
exclusion ; but there are so many instances in which, by reason of the ab-
sence of planes and straight lines, the context must be depended upon in a
* greater or less degree, that needless ambiguities should be avoided.

The foregoing illustration, however, by no means exhausts the list of
possible ambiguities. In the normal position of a vertebrate, the heart is

THE INTRINSIC TOPONOMY. A 23

beneath the Columna vertebralis; in the natural attitude of man, it is
beneath the bifurcation of the ¢rachea; in the position in which both man
and quadrupeds are commonly dissected, the heart is beneath the sternum ;
finally, it may be said to be beneath the ribs or the MM. intercostales in the
sense of being covered by them. ‘The single English word here means suc-
cessively ventrad of, caudad of, dorsad of, and entad of the organs on four
different sides of it. Whatever may be thought best by the writers of de-
scriptions for advanced students, we hold that the use of such terms ina
work expressly designed for beginners would be little else than a self-stulti-
fication of its authors and a mockery of its readers.

§ 38. The Intrinsic Toponymy.—Following the suggestion of Bar-
clay, and the more or less consistent example of the other writers above
named, we shall wholly discard all terms which “contain an allusion to the
situation of different objects, as they stand with respect to the heavens and
the earth ;” and shall designate the aspects and regions of the body by terms
derived from names which have been applied to the parts themselves. Hence
we shall speak of the cephalic and the caudal ends or aspects or regions ; of
the dorsal and ventral aspects or regions; and of the deztral and sinistral
aspects and regions.

Such terms constitute a Toponvmical Vocabulary which is based upon
intrinsic instead of purely extrinsic and accidental relations.

§ 39. Cephalic and Caudal.—Barclay proposed the words atlantal
and saeral for the designation of the position of parts lying toward the head
or the tail in reference to an imaginary plane dividing the body at about the
middle of its length.

In many of the lower vertebrates, however, there is no distinct atlas or
sacrum, and in any case these terms would not apply strictly to parts beyond
the bones in question ; hence Barclay devised for the head an entirely new
set of terms, inial, glabellar, etc. So far as we know, aélantal and sacral
occur only in the writings of Owen (A, III, 519) and Turner (7, 819).

Thacher has employed (7, 282 and 292) orad as both adjective and
adverb, but the correlative aborad, which might have been expected, has not
been observed by us in his papers.

Cephalic and caudal are employed by Cleland (7), and are recommended
by Quain as stated above. Their signification is obvious, and practically
there seems to be no serious objection to their use, although it is possible to
imagine cases where some ambiguity might arise from the fact that each is
employed in two senses, the one relative, and the other absolute. For
example, in the ahsolute sense, only the vertebre of the tail are caudal;
but relatively,cawdal may be used to designate one or more vertebra in any
part of the series, which are situated nearer than others to the caudal end of
the body. So too, we may speak of the caudal aspect of the skull, or of the
cephalic members of the series of caudal vertebre.

24 INTRODUCTION.

§ 40. Dorsal and Ventral.—By their derivation, and by their appli-
cation to distinctly differentiated and universally recognized regions, these
two terms are perfectly acceptable so far as the vertebrates are concerned.

Should the alleged correspondence of the ventrai region of the Vertebrate with the
tergal region of the Arthropod prove to be one of true homology, it may be desirable ‘in
time to discard dorsal and ventral for more suitable terms, but for the present, if on
practical grounds alone, it seems well to retain them.

As stated above, these are among the terms recommended in Quain, and
they have been somewhat generally employed by anatomists; Huxley, A, 1
et seg.; Owen, A, III, 3; Sanders, 7; Hadlich 7, 97, note; Mivart, A, 69,
B, 263 and J, fere.

To avoid ambiguity, it will be better to employ dorsal only in the sense
here indicated, and to characterize the costiferous vertebra as ¢horacic.

§ 41. Dextral and Sinistral.— These are simply more technical
equivalents of the English right and left. No objection has been made to
them, or substitutes offered for them.

§ 42. Lateral.—Usually the two sides are so similar that what is true
of the one is, approximately at least, true also of the other. Hence it is
often desirable to employ a general term applicable to either or both the right
or the left. Such a term is Jateral, the derivation of which properly indi-
cates the fact that, as compared with the two ends or the top and bottom,
the right and the left are the stdes. Lateral is therefore a more general
term, while deztral and sinistral are specific.

§ 43. Mesal.—In the restricted literal sense of entering into the com-
position of the head or the tail, certain parts may be said to be absolutely
cephalic or caudal; but in most cases these terms, like dorsal and ventral,
merely indicate a greater proximity of the part so characterized to one or
the other of the four aspects in comparison with some other part, named or
implied. Even when used in an apparently absolute sense, they are really
relative terms.

This is because there has not been detected any structural line or plane
of demarcation between the two ends of the body, or between the back and
the belly.

But with right and left, the case is different. The right eye and the
right kidney are not simply nearer than the left to the right side or aspect
of the body; they also-form parts of the right half of the body, and this
half, notwithstanding the numerous instances of continuity, is so readily
distinguishable from the left, that one may almost describe the body as if it
were formed by the union of two pieces, similar, but reversed in form and
position.

The plane of junction of the right and left sides is at or near the middle
of the body, and has been known as the middle or median plane, a longi-

THE REGIONS OF THE LIMBS. 20

tudinal line therein being called a middle or median line. But since certain
parts lie upon or cross this plane, and since it is sometimes desirable to
speak of lateral parts as more or less near it, Barclay proposed (A, 121)
for it the single word mesion.

_ We have not met with this word in other writings, although mesial and
mesiad are not infrequent.

Nevertheless, it seems desirable to designate this middle plane by a single
word which is at once significant, short and capable of inflection.

Such a word is meson, from the Greek 16 péoor, the middle, equivalent to
the more ponderous Latin meditullium. This word and its derivatives were
proposed (9) by the senior author.

For convenience, any point or line therein may be called meson, but the
lines most frequently referred to in description constitute the dorsal and
ventral borders of the plane, and may be known as dorsimeson and ventri-
meson respectively.

To avoid ambiguity, it would be well to employ mesa/ and its derivatives
only in reference to the meson ; intermediate (middle) may then be applied
to the second of any series of three similar parts; while medial could be
used in reference to the digitus medius.

§ 44. Convenient additions to the vocabulary of toponymy would be terms of single

words, corresponding with meson, but indicating respectively the dorsal, ventral and other
aspects of the body. We refrain, however, from making any svecific suggestion.

§ 45. Designation of the Regions of the Limbs.—The body as a
whole, with the cat as with most vertebrates, consists of two general
divisions, axial and appendicular ; the former is the body proper or soma ;
the latter are the limbs or membra.

On account of the approximately vertical position of the arms and legs
in the natural attitude of man, their attached and free ends had been called
superior and inferior, or upper and lower.

For these terms, as inapplicable to the limbs of many animals (fishes and
turtles, etc.), as are the terms anterior and posterior (in the anthropic sense)
to the rest of their bodies, Barclay wisely substituted proximal and distal,
which have been very generally adopted.

We speak, therefore, of the attached end of any appendage, as limb, ear,
barbel, tentacle, horn, spine, as the proximal end, its free or unattached
extremity being in like manner called distal. The same terms apply to the
corresponding ends of the segments, bones and muscles of these appendages.

As has been well remarked by Mivart (2, 509), ‘‘The tail, to a
certain extent, partakes of the natures of both the trunk and the limbs.
It is like the limbs in that it is solid, that it contains no body-cavity,
and is not traversed by the alimentary canal.” Still, the tail is really
a division of the soma, and its two ends should be designated as cephalic
and caudal.

26 INTRODUCTION.

Barclay seems not to have concerned himself for other than English users of his new
terms, and we can only conjecture what he would have made the classical forms of
proximal and distal. Following analogy, they may be rendered prozimalis and distalis,
though no such Latin words exist.

For the four other aspects (borders or sides) of each limb, Barclay
proposed the terms wlnar, radial, anconal and thenar, tibial, fibular,
rotular and popliteal.

These have been employed to some extent by later writers, but they are
open to at least three objections: they are specific instead of general; the
bones from which they are derived are not recognizable in “fishes ;” with
many mammals, the ulna and radius are crossed instead of parallel, and with
some the ulna and tibia are but slightly developed.

Huxley and some other English anatomists have employed the general
terms preazial, postaxial, epaxial, and hypaxial. But these words are liable
to misconception because axial has been used already in reference to not
only the axis vertebra, but also the entire skeleton of the trunk as contra-
distinguished from that of the limbs.

Perhaps the chief objection to all these terms is that they are not really
necessary, and introduce undesirable verbal complications.

The limbs are certainly part of the body, and whether or not, as held by
Thacher (7) and Mivart (7), they are essentially and primarily only isolated
and differentiated portions of continuous lateral fold, there seems to be a
general assent to Huxley’s proposition (4) that, for comparison, the limbs
should be regarded as extended laterad at right angles with the soma.

Hence it seems to us most natural to apply to the aspects of the limbs the
same terms which are applied to-the corresponding regions of the soma.
Thus each limb presents a dorsal and a ventral aspect, a cephalic and caudal
aspect, and a proximal and distal end.

§ 46. Terms of General Application to the Whole Body.— Central
and peripheral were proposed by Barclay, and have heen very generally used
by anatomists. They are especially applicable to the parts of the nervous
and vascular systems, since the vessels and the nerves may be said to radiate
from or converge to the heart and the myelencephalon (cerebro-spinal axis)
as anatomical and physiological centers.

Barclay also recognized the need of terms denoting nearness or remote-
ness with respect to the surface of any part of the body, and proposed dermal
in the one case, central doing duty also in the other.

Most anatomists, however, have contented themselves with the older
words, outer and inner, superficial and deep, sublime and profound.

Of these terms, three are incapable of inflection ; all are very commonly
employed in a metaphysical sense, and are therefore more or less ambiguous ;
while the last two are quite inappropriate to the insignificant structures
with which they are often associated.

VERBAL INFLECTIONS. 27

The need of other terms than those in use was so generally and so
strongly felt among the students in the Anatomical Laboratory of Cornell
University that the suggestion to employ entul and ectal was welcomed, and
they were published in the article (9) already mentioned. Derived respec-
‘tively from évro¢ and é«rd¢ their significance is obvious, while their brevity
and capacity for inflection will probably commend them to accurate working
anatomists.

Both words are already familiar in the words ecfozoa, entozoa, entoptic,
entogluteus, ectogluteus, ctc. Asa rule, it will probably be well to:employ
them in reference to lamine or surfaces.

§ 47. Inflections.—Barclay proposed that the various adjective forms
should be converted into adverbs by substituting for the ending a/ the let-
ters ad, the Latin equivalent of the English ward. Thus dorsal, ventral,
dextral, sinistral and lateral became dorsad, ventrad, dextrad, sinistrad, and
laterad. Substituting mesal for mesial, and cephalic and caudal for atlantal
and sacral, we have in addition the terms mesad, cephalad and caudad.

Proximal, distal, ental and ectal are readily converted into the adverbs
prozimad, distad, entad and ectad.

For example, the dura (mater) may be described as ectad of the brain,
but entad of the cranium. A part may be divided by cutting either ecto-entad,
from without inward, or ento-ectad, from within outward.

The adverbial forms occur less frequently than the adjectives, but dorsad
is used by Huxley, as reported in Nature, Jan. 6, 1881, p. 281, and this
together with ventrad and imesiad are systematically employed by Mivart in
a recent paper, (7,) although not in his latest work (B).

§ 48. Use of the Prepositions: Of and From.—0Of is used with
terms of relative position, when the verbs fo be or to lie are expressed or
understood. Thus we say, the elbow is distad of the shoulder.

From is used with active verbs implying extension or passage from
one point to another; thus, the myelon extends caudad from the brain; the
humerus extends distad from the shoulder, etc.

§ 49. Limitations to Accuracy.—The use of the terms aboye
enumerated certainly renders it possible to be more definite in description.
Yet absolute accuracy and exactness are often unattainable, with an animal
like the cat, where there are few plane surfaces or straight lines. It often
becomes necessary to designate the relative positions of two parts, or the
direction of a line upon a more or less curved or undulating surface. For
example, on Fig. 7 representing approximately the outline of a transection
of the body, the point @ is obviously laterad of the point 6. So too, the
point ¢ is dorsad of the point d. But the point ¢ may be described as
latero-ventrad of b, cr dorso-mesad of d; it would seldom happen, however,
that the curvature should be equal on both sides, and usually the needed qual-
ification would be supplied by tae context.

28 INTRODUCTION.

' $50. Derivatives—With derivative words the connecting vowel is commonly i;
€. g., alipes, claviger, fatifer, fidicen, fluctigena, decimanus, neurilemma, and xiphisternum.
But classical exceptions are mulomedicus, quadrupedus, noctuvigilus, and decumanus. In
common English and scientific terms of Latin or Greek origin the 0 is common; e. g.,
ambodexter, burgomaster, gastrotomy, termonology, ventroinguinal, lateroflexion, mucopuro-
lent, vasomotor, curvograph, neuroglia, oculospinai, pleuroperitoneal, xiphosura, septopyra,
hemoglobin, cephalotribe, etc. Rarely is it e as in venesection.

Both analogy and euphony lead one to use the 7 when the first part of the word is of
Latin origin, and the o with the Greek.

Hence we have dorsimeson, ventrimeson, dorsicumbent, latericumbent, miners
sinistriversion, cephaloduction, caudiduction, etc. ?

$51. Compound Words.—The two Latin compounds known to us are veneri-vagus
and vesti-contubernium. The following common or technical English compound words
are selected from Webster’s English Dictionary, or the Medical Dictionaries of Dunglison,
or Littré et Robin, or from the writings of Barclay, Humphrey (E), and Straus-Durckheim :
Anglo-Saron, concavo-conver, dextro-gyrate, ventro-appendicular, costo-vertebral, costo-
alaris, caudo-pedal, vsseo-cutaneous, occipito-scapularis, dorso-lateral, meso-dorsal, sterno-
clavicular, clavo-cucullaire, clavi-sternal, clavio-humeralis. By analogy with the foregoing,
compound terms of direction should read dorso-ventral, caudo-cephalic, meso-lateral,
sinistro-cephalic, etc.

§ 52. Combination of Words.—The names of two or more organs or tissues may
be conjoined like the words for regions ; thus we say musculo-tendinous, or gastro-hepatic.
But the names of organs are never combined with the names of regions; hence such a
term as dorso-gastric does not occur.

§ 53. Hybrid Words.—Some of the terms already mentioned are formed by the
union of Latin with Greek words; e¢. g., dorsimeson, meso-lateral, and caudo-cephalic ;
several others are likely to be employed; e. g., clavo-mastoideus, and felitomy.

Beyond the occasional intimation, in the dictionaries, that a term is hybrid, the
subject seems to be ignored, and it might fairly be inferred that literary authorities
entertain one or the other of two opposite convictions: either mongrel words are verbal
monstrosities which will be shunned instinctively by all wel!-regulated minds, or there
is no more serious objection to their use, or even their creation, than to the employment,
or even the production, of mules, or the mixed varieties of grapes and roses.

However this may be, the fact is that the Latin and the Greek tongues have
united to form the following nine hybrids which may be found in Latin writings:
anticato, biclinium, cryptoporticus, dentarpaga, epitogium, monosolis, monoloris, pseudo-
flavus, and pseudo-urbanus. Of these, the third only occurs with any degree of
frequency.

Whoever will spend the time to look through an Unabridged Dictionary of the
English language—and the interest as well as the instructiveness of such a search can
hardly be realized by those who use the volume only for occasional ‘eference—will find
that, after excluding the twenty-five or more words ending with meter, which may
perhaps be derived directly from the Latin form metrum, there are more than one hundred
hybrid words, many of them in good standing. Many more are to be gieaned from the
Dictionaries of Medicine and the other Arts and Sciences.

Nevertheless, it is probable that a due regard for the feelings of the classical purists
in whose eyes language was not made for man, but rather man for language, will lead
scientists to refrain from the introduction of mongrel terms when others will serve the
purpose, and we shall be pleased to receive suggestions leading to the substitution of
wholly unobjectionable words for any of the hybrids which may occur in the present work.

PRIMARY DIVISIONS OF THE BODY. 29

Practical Application of the Foregoing Considerations in the
Designation of Some Parts, and in the Indication of their Relative
Position and Direction.

§ 54. The Primary Divisions of the Body.—Soma and Mem-
bra.—The entire body of a normal and complete Vertebrate presents a
principal azial portion, and an appendicular portion, the arms and legs,
which may be spoken of, collectively, as the limbs or membra.

Neither the classical nor the vernacular terms for these divisions have
been used with desirable exactitude. With the ancients, corpus might
signify either the entire body, or the trunk as distinguished from the head,
while the English dody may refer to either the whole body in distinction
from the mind, the axial part in distinction from the appendicular part, or
the principal portion of the former in distinction from the head and the tail.
Truncus usually meant the body apart from the limbs, but the head and the
trunk are sometimes spoken of as distinct regions.

In view of this lack of discrimination we venture to suggest that the
entire physical part of an animal be called the corpus or body ; that truneus
and trunk be applied only to that part of the axial portion which intervenes
between the neck and the tail ; and that the entire axial portion, including
head, neck, trunk and tail be denominated the soma.

It is true that the Greek owwa was generally equivalent to the Latin
corpus, and that many of its derivatives and compounds refer to the entire
organism ; but the term somatome was proposed by Goodsir to indicate a
vertebral segment, of which the limbs are merely occasional components.
Somite and somatopleure are used by Balfour, A, I, 3, 141.

The undesirability of the introduction of a somewhat unfamiliar term is
fully admitted. It is probable, however, that it need not be employed very often.

§ 55. Figure 2 is a diagram of the dorsal aspect of the cat, intended to
illustrate certain very general features of it or of any other vertebrate
provided with two pairs of limbs.

The outline of the soma is elliptical, the larger end corresponding to the
head, and the smaller with the tail.

The arms and legs are represented as lateral appendages projecting at
right angles with the longitudinal somatic axis, or meson.

Each limb has an attached or proximal end, and a free or distal end.

The right and left sides of the entire body are antitropic or symmetrical
with each other ; that is, they are reversed repetitions of one another in
opposite directions.

§ 56. Beginners in Anatomy are sometimes confused by the fact that,
with some figures, the right is at their own right, while with others the
right of the figure is upon their left.

This confusion may be avoided by a preliminary exercise with a familiar
object : —

30

INTRODUCTION.

xs ense -organ
¢ aput
fee]

Sinistral oe oe
Limbs
Nt isital end

columna

verte bralis~ _.canalis

neuralis

Loe
canal

ey
cardia
Fig. 3. ZT hecnaekicn sabe

DIAGRAMS OF THREE ASPECTS OF A VERTEBRATE,
EXHIBITING THE MOST GENERAL FEATURES.

THE POSITION OF FIGURES. oT

Hold a book and note its several aspects—the top and bottom, the back
and front, the right and left sides. For the purpose of comparison, these
aspects may be considered to correspond with the head and caudal aspect,
the back and the belly, the right and left sides of a man or a cat.

When the book is held so as to permit the reading of a title printed
across the back, the various aspects coincide in position and direction with
the body-aspects. The right is at the right of the observer, and the left at
his left ; the back faces in the same direction with his own, while the top of
the book is upward, and its bottom down.

But when the book is held just ready to be opened, the top and bottom
have the same directions as before, but the back and front, the right and
left sides are reversed. The right of the book is opposite the left of the
observer, and vice versa.

In the first case, the observer and the book are related as are two persons
one behind the other; in the second case, the relation is that of two persons
facing each other, and as when one views his own image in a mirror.

Again, if the book is held so that the lower end is in view, the right and
left still correspond with those of the observer; but if it is turned so as to
expose the ¢op, then the right and left are reversed. The same difference
exists in the case of transections of objects. If a book were cut across, there
would be exposed two cut surfaces, the bottom surface of the upper part,
and the top surface of the lower part. With an animal, these would be
called the caudal surface of the cephalic part, and the cephalic surface of
the caudal part. If the former is viewed, the right and left of the surface
coincide with those of the observer; if the latter, then the right and left are
reversed.

. As with objects, so with their representations in pictures and diagrams.
The right and the left, the dorsal and the ventral aspects, are to be so desig-
nated, whatever may be their position on the page or with respect to the
observer.

The foregoing remarks concern symmetrical figures, which represent
either the dorsal, the ventral, the caudal or the cephalic aspects of an ani-
mal, or its parts. As a rule, in the present work, such figures are so placed
that the meson coincides in direction with that of the observer, and with the
longer diameter of the page, as, e. g., Fig. 2 and 3.

Figures which, like Fig. 4, are wnsymmetrical, and represent the lateral
aspects of animals or their parts, are usually so placed that the meson lies
across the page, and at a right angle with that of the observer. Usually,
also, in accordance with distinguished precedent, as remarked in a paper
(17) by the senior author, the cephalic end of such figures is turned toward
the left of the page and of the observer.

- §57. Position and Direction on the Soma.—The letters A, B, C, _
D, H, F, G, H, I, K, with the dotted lines between them are introduced for

32 INTRODUCTION.

the sake of illustrating some of the more common cases of designation of
relative position and lines of direction.

The points A, B and C lie at or upon the meson, and are therefore mesal.
So also, the dotted lines between the points are mesal lines.

D is not at the meson, and is therefore /aterad (in this case sinistrad )
of B; but it lies nearer the meson than E, and is therefore mesad of it.

B lies cephalad of C, but caudad of A.

E lies latero-cephalad of C, and latero-caudad of A.

A lies meso-cephalad of E, and C meso-caudad. The line A, B, C is a
cephalo-caudal, or caudo-cephalic line, or it may be described as extending
caudad from A, or cephalad from C.

The line E, D, B, is a meso-sinistral, or sinistro-mesal line, and may be
said to extend either mesad from E, or laterad (sinistrad) from B.

The line A, E extends meso-cephalad from E, or sinistro-caudad from A.

The line A, B, C coincides with the meson, and a cut upon it would be
a hemisection.

The line E, D, B, E’ is a transverse line, or at right angles with the
meson, and a cut therein would be a transection.

Finally, an organ on the meson, and represented, for instance, by B, is
not only mesal in position, but also called azygous or unpaired ; while two
similar organs, one upon each side, and represented for instance by E’, are
lateral in position, and called paired organs. Each such paired organ may
be called the platetrope of the other, or its lateral homologue, or the fellow
of the opposite side.

The letters upon the right leg have similar relations, excepting that
proximal and distal take the place of mesal and lateral or dextral and
sinistral.

I and K, for example, lie respectively cephalad and caudad of G; while
G lies caudad of I and cephalad of K. F lies prozimad of G, and G of H;
H is distad of G, and the relative locations of the three may be designated
as proximal, distal and intermediate.

A. The reasons for representing the limbs in the position here given them will be
more advantageously presented in § 80.

B. The dotted lines connecting the two extremities of the soma with the distal ends
of the limbs illustrate the idea referred to on p. 26 that the limbs are essentially remnants
of two continuous lateral folds ; see also Balfour, A, III, 501.

$58. Figure 3 represents an ideal transection of the body of a cat, or
any other vertebrate possessing limbs.

Only some of the more constant and essential features are here shown.

Near the middle of the figure is the section of the Columna vertebralis.

The Columna vertebralis or spinal column may be of bone, cartilage, or
2 semi-solid material with membraneous walls, according to the animal ex-

THE BODY PLANES. 33

amined, the degree of development, or the part which is divided. It lies
upon the meson, and serves therefore as a boundary between the right and
the left sides of the animal.

In most animals it is located, in nearly its whole length, nearer that side-
of the body which is commonly upward in ordinary locomotion ; that is, it is
nearer the dorsal aspect. ‘There is no definite plane of contact of the dorsal
with the ventral region as of the right with the left side ; but, for convenience,
the two regions may be regarded as meeting at a line X, X’, passing from side
to side through the middle of the Columna vertebralis.

Dorsad of the Columna is a canal, the Canalis neuralis, containing the
myelencephalon or cerebro-spinal axis, (brain and spinal cord). Ventrad of
the Columna is a cavity, usually more capacious, the celum, or general body
cavity, in which are the heart, alimentary canal, and other viscera.

This arrangement of principal organs, in two cavities, on opposite sides
(but not on the right and left) of @ mesal axis is a constant character of all
Vertebrates, and, with perhaps a few exceptions, is peculiar to the group.

§ 59. Figure 4 represents an ideal hemisection (section on the meson) of
such a body as is represented in figures in 2 and 3. The cephalic aspect or
head looks toward the left.

§ 60. The Body Planes.—For the sake of precision in the use of
toponomical terms, the planes already referred to will, be more distinctly
defined ; see Fig. 5.

§ 61. 1. The Meson.—This is a plane passing lengthwise of the body,
and dividing the whole into 5 oecehan sb equal and similar right and left
halves.

For convenience, the dorsal and ated borders of this plane may be
called the dorsimeson and the ventrimeson respectively.

Organs like the nose, the stomach, and the wrocyst (bladder) appearing
upon both sides of the meson are said to be mesal or azygous. They are, at
least primarily and approximately, symmetrical in themselves ; that is, they
consist of similar right and left halves.

Organs like the eyes, the lungs, and the kidneys, which form pairs, the
one upon the right and the other upon the left of the meson, are called
lateral or paired antitropous organs. Hither of them is symmetrical with
its fellow ( platetrope), but not in ttself. .

§ 62. 2. An imaginary transverse, dorso-ventral plane, at right angles
with the meson, and dividing the body into a cephalic and a caudal region.

§ 63. 3. An imaginary longitudinal, dextro-sinistral plane, extending
the whole length of the body, and dividing it into a dorsal and a ventral
region.

These three body-planes correspond in direction with the three dimen-
sions of a solid, length, height, and width. Each is at a right angle with
both the others. The longitudinal sematic axis lies in the meson.

3

34 INTRODUCTION.

As already indicated, the position of the meson is fixed; that of the
other two planes is purely conventional and for convenience in a given case.

Ventri meson.

Ventral abpect.

Fie. 5.—DIAGRAM OF THE THREE BODY-PLANES, WITH THE
VARIOUS LINES OF DIRECTION.

§ 64. Designation of Position and Direction.—By the use of terms
derived from meson, and from the names of the general regions or aspects
of the body, it is possible to designate positions and lines of direction with
considerable precision.

There are two general cases :—

1. Where the points to be located are on a line which itself lies in one of
the three body planes, or in a plane parallel to one of them.

2. Where the points to be located are on a line which is not in either of
these planes, but connects some two of them like the diagonal of a solid;
e. g., the points H, K, at the ends of the line HK.

Under case 1, the lines may be either direct or oblique.

§ 65. Direct lines may be perpendicular to the meson, as the line SFI,
or any other line passing directly from one side of the body to the other.
Such a line would be the line connecting the eyes, or the heads of two ribs.

Direct lines may lie either in the meson itself, or in an imaginary plane
parallel thereto and either parallel or perpendicular to the longitudinal
dorso-sinistral plane ; e. g. ABC or MHL. Such lines pass directly from
the dorsal to the ventral aspect of the body, or from the caudal to the
cephalic aspect.

All direct lines may be also characterized as coinciding with the inter-
section of two of the three body-planes, or of planes parallel thereto.

DESIGNATION OF RELATIVE POSITION. 35

§ 66. Oblique lines lie in one plane, but are not perpendicular to either
of the other planes ; neither do they coincide with the intersection of two of
the body planes, or of planes parallel thereto. They are comparable with
the diagonal of a parallelogram. Such lines are EC; ME; BH.

§ 67. Designation of Direct Lines.—This requires a term of two
words, of which one indicates the point of departure and the other the point
of approach.

On the figure of the model, the line ABC is a cephalo-caudal line, or
extends cephalo-caudad ; or the order may be reversed by saying that it is a
caudo-cephalie line, or extends caudo-cephalad. The line CFK is a dorso-
ventral or ventro-dorsal line, and the line IFS is deztro-sinistral or sinistro-
dextral.

§ 68. Designation of the Relative Positions of Points upon
Direct Lines.—This requires a term of but one word, adverbial in form,
and indicating a point of approach.

In Fig. 5, C is cephalad of B, and dorsad of F; A is caudad of B; H is
ventrad of M, but dorsad of L.

In the body, the sternum is ventrad of the heart, the Columna vertebralis
is dorsad, and the diaphragm is caudad of the same organ.

In man, the sternum would be said to be before, or in front of, or anterior
to the heart; but in animals it might be described as below, under or inferior
to the same organ.

It should be kept in mind that these terms are relative, not absolute.
The diaphragm, for example, lies cephalad of the stomach, but caudad of the
heart.

§ 69. Designation of Oblique Lines.—This requires a term of two
words, both of which indicate points of approach. The points of departure
are usually apparent from the context. Thus, the line E, C, extends both
toward the head and the back; hence it is called a cephalo-dorsal line, or
described as passing cephalo-dorsad. The same line could be described as
caudo-ventral, or as extending caudo-ventrad.

In man, such a line would be described as extending forward (ventrad)
and downward (caudad). In comparative anatomy, it might be said to pass
downward (ventrad) and backward (caudad).

§ 70. Designation of the Relative Position of Points upon
Oblique Lines.—This requires a term of two words, in the adverbial form.

On the line CE, C is cephalo-dorsad of E, while E lies caudo-ventrad
of C.

In man, C would be said to be above and behind; in animals, in front
and above.

§ 71. Designation of Diagonal Lines not in Either of the Three
Planes.—This requires a term of three words, all of which indicate points
of approach; the order of the words is immaterial.

36 INTRODUCTION.

In Fig. 5 the line HK may be described as having a dorso-sinistro-caudal
direction. In man, it would be said to extend backward (dorsad), to the left
(sinistrad), and downward (caudad). But with an animal it would be
described as passing upward, to the left, and backward.

§ 72. Designation of the Relative Position of Points upon
Diagonal Lines not in Either of the Planes.—A term of three words
is needed, with the adverbial termination. Thus H is dorso-sinistro-caudad
of K ; or K is ventro-meso-cephalad of H.

§ 73. In all these cases, it is sometimes more convenient, and equally
intelligible, to substitute for the more specific terms deztral and sinistral,
the more general terms mesal and lateral. The line ME, for example, might
be called dorso-lateral instead of dorso-sinistral; or it might be called ventro-
mesal, and the context would show which side was referred to. If, while
dissecting upon the left side, the student were directed to cut mesad for
2 cm., he would cut towards the right, that is dextrad.

§ 74. Designation of Direction and Relative Position upon the
Limbs.—The various terms are employed and combined as for the soma,
excepting that in place of mesal and lateral, or dextral and sinistral, there
are used the terms proximal and distal.

§ 75. Ectal and Ental, and their Derivatives.—The general signifi-
cance and uses of these terms have been indicated in § 46. Other examples
will be given in connection with Fig. 7.

A special employment of the two words in combination is for the sake of
designating the direction of an incision. Ordinarily incisions are carried
from the surface inward, that is ecto-entad ; sometimes, however, it is desir-
able to divide parts, especially the skin and abdominal parietes, by an
incision in the opposite direction—ento-ectad.

§ 76. Figure 6 is intended to show certain features of the cat, regarded
as a Mammal, and not simply as a Vertebrate, as in Figures 2, 3,
and 4.

As in Fig. 2, the body is ventricumbent, so as to expose the dorsal
aspect.

The limbs (arms and legs) are extended at each side at right angles with
the axis of the soma, in what is commonly regarded as their normal position.

The principal divisions of the body are named in the Table on p. 39.

§ 77. The Soma and its Divisions.—The largest division of the
soma is the trunk. The tai] forms an extension in one direction, while the
other end is continued as the neck and head. The neck is narrower than
the head or trunk, and the head itself consists of the cranium and
the face.’

§ 78. The Trunk and its Divisions.—There are readily distinguished
three regions of the trunk. The intermediate region or abdomen has only
fleshy sides, while the more caudal—pelvis—has the Os innominatum on

NORMAL POSITION OF THE LIMBS. 37

each side, and the more cephalic—thorav—is enclosed by the ribs (cost)
and their cartilages (costicartilagines).
The ventral and larger cavities of these three trunk regions are, strictly speaking,

cavum abdominis, cavum pelvis, and cavum thoracis ; but they are usually called by the
names of the regions themselves.

The abdominal and pelvic cavities are continuous; but between the
abdomen and thorax, in the cat as in all other Mammals, there intervenes a
musculo-tendinous partition—the diaphragma.

With all the lower Vertebrates, the diaphragm is absent or incomplete, so that the
three cavities are continuous, and constitute the celwm or trunk cavity. Sometimes it is
convenient to apply this general name with Mammals.

A part of the alimentary canal is introduced for the sake of illustrating
a somewhat peculiar case in the designation of relative positions which will
be referred to in connection with the explanation of Fig. 7; § 91.

§ 79: The Vertebre.—As shown in Fig. 30, in the adult cat, the
vertebree form a continuous series from the caudal aspect of the cranium to
the tip of the tail. In this diagram, however, only the thoracic vertebre
are shown by a series of squares representing their centra (bodies). The
lines extended dextrad from the centra indicate the right coste (ribs). The
centra and coste are included in this diagram merely to illustrate the
method of notation of parts which form a series. The most cephalic is
numbered 1, ete.

§ 80. Normal Position of the Limbs.—For accurate comparison of
the limbs with each other, or with those of other animals, it is desirable
that they should be placed, or regarded as placed, in some wniform normal
position.

One of the many possible natural attitudes of the cat’s limbs is shown in
Fig. 30, and there is great variety among other Mammals.

Huxley has proposed (4) that all limbs should be compared as if in the
position shown in Figures 2 and 6. In this condition they stand out at right
angles with the body (soma), the extensor surfaces (with the convexities of
the elbow and knee) being placed dorsally, and the flexor surfaces ventrally,
with both pair of limbs. This is the position which they have in the
embryo Mammal, according to Kélliker, and it continues throughout life in
some Amphibia and Reptiles.

There is some difference of opinion as to whether the ventral aspects of the limbs
should not be regarded as facing more or less directly mesad; but in other respects
Huxley’s view has been adopted by several anatomists, including Mivart, Pagenstecher,
Rolleston, Flower, Coues, and the senior author, in. whose paper (10, 9-17) will be found
fuller references. See also Balfour, A, II, 508.

Owing to changes which occur after the first formation of the limbs, it

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40 INTRODUCTION.

is not easy, with most Mammals, to replace them in the normal position.
It may, however, be readily accomplished with an orang, and without much
difficulty with the arms of a cat or a child.

The student may exemplify the normal position of the arms approxi-
mately by getting upon all-fours, placing the palms upon the floor at either
side, with the fingers pointed laterad ; the convexities of the elbows should
then be made to look dorsad and laterad, upward and outward. If now the
arms be extended laterad to their utmost length, still keeping the palms
against the floor, and the elbows away from it, the limbs will have nearly
the position shown in figures 6 and 7.

§ 81. Limb Segments.—With the cat, as with most air-breathing
Vertebrates, each limb presents at least three divisions or seymenta, con-
nected with each other and with the soma by three arthra (joints or
articulations).

These segments and arthra are thus proximal, intermediate, and distal.
As shown upon the right of the diagram, the proximal segments are
brachium (upper arm) and meros (thigh). The intermediate segments are
antebrachium (forearm) and crus (leg proper). The distal segments are the
manus (hand) and pes (foot).

The entire limbs are joined with the trunk by the shoulder and hip
joints, while the eldow and knee intervene between the brachium and ante-
brachium, the meros and crus, and the wrist and ankle between the ante-
brachium and manus, the crus and pes respectively.

The technical names for the arthra placed in parenthesis are those which were pro-
posed in 1873 by the senior author (ZO, 18); but as they have not been generally adopted
they are not insisted upon here.

Each manus and pes also presents a threefold division, carpus, metacarpus,
and digits (thumb and fingers) ; tarsus, metatarsus, and dactyls (toes).

The distinctive names for the digits and dactyls are placed under them.
The primus (great toe) is represented by a dotted line, in consideration of
its absence from the cat.

§ 82. Limb Bones.—On the left side of the diagram are shown the
bones corresponding to the segments already enumerated.

The proximal segments have each a single bone, the humerus and femur,
which are represented as subcylindrical, with enlarged extremities.

The intermediate segments have each two bones, ulna and radius, tibia
and fibula, which, in the normal position of the limbs, lie side by side, the
radius and tibia on the cephalic aspect of the limbs, and the ulna and fibula
on the caudal. These bones are likewise subcylindrical, but the ulna and
tibia are larger at their proximal ends, while the radius and fibula increase
more or less distad. The patella (knee-pan) and the olecranon and other
special features are not shown.

_ CARPUS AND TARSUS. 41

§ 83. Marsh has proposed (Z) to apply general names to the corresponding bones of
the arm and leg. Thus, the bones of the proximal segments are the Ossa propodialia ;
the radius and ulna, the tibia and fibula, constitute the epipodialia ; the bones of the
carpus and tarsus are mesopodialia ; the metacarpalia and metatarsalia are—as indeed
they have previously been called—the metapodialia, and the old term phalanges is
retained for the bones of the digits and dactyls.

§ 84. Carpus and Tarsus.—The carpalia (bones of the carpus), and
the ¢arsalia (bones of the tarsus), are variously interpreted by different
writers; see Balfour, A, II, 508.

The following general description, based chiefly upon the researches of
Gegenbaur, is given by Huxley, A, 31 :—

‘‘There is reason to believe that, when least modified, the carpus and
the tarsus are composed of skeletal elements which are alike in number and
arrangement. _

‘One of these, primitively situated in the centre of the carpus or tarsus,
is termed the centrale ; on the distal side of this are five carpalia, or tarsalia,
which articulate with the several metacarpal or metatarsal bones ; while, on
its proximal side are three bones—one radiale or tibiale, articulating with
the radius or tibia ; one wlnare or fibulare, with the ulna or fibula; and one
intermedium, situated between the foregoing.

“ Carpal and tarsal bones or cartilages, thus disposed, are to be met with
in some Amphibia and Chelonia, but, commonly, the typical arrangement is —
disturbed by the suppression of some of these elements, or their coalescence
with one another.

«Thus, in the carpus of man, the radiale, intermedium, and ulnare are
represented by the scaphoides, lunare, and cuneiforme respectively. The
pisiforme is a sesamoid bone, developed in the tendon of the M. flexor carpi
ulnaris, which has nothing to do with the primitive carpus. The centrale
is not represented in a distinct shape, having probably coalesced with one of
the other elements of the carpus. The fourth and fifth carpalia have
coalesced, and form the single wnciforme. See § 421.

‘In the tarsus of man the astragalus represents the coalesced tibiale and
intermedium ; the calcaneum the fibulare. The naviculare (scaphoides of
Anthropotomy) is the centrale. Like. the corresponding bones in the
carpus, the fourth and fifth tarsalia have coalesced to form the cuboides.”

§ 85. In the cat, so far as we can judge from the figures and statements
of Flower (36, 138), and Mivart (B, 96, Fig. 60), and from our own
observations, the condition of things is as follows :—

In the tarsus, aside from peculiarities of shape, the tarsalia and their
connections are as in man.

In the carpus, the same is the case, excepting that the scapho-lunare
represents not only the scaphoides and the lunare—the radiale and inter-
medium of the primitive carpus—but also the centrale. Flower found

42 INTRODUCTION.

this element distinct in a dog; the senior author has observed (19, 301,
Fig. 1,) it as a separate center of ossification in a young lion, shown in
Figure 47; and it is apparently shown, though not alluded to, by Mivart,
(B, Fig. 60.)

There are many interesting and important questions connected with the composition
of the carpus and tarsus of different Vertebrates, and those interested in the subject
may consult Gegenbaur (Lankester), A, 479-481, 487, 488, and the papers of that anato-
mist, Morse (18 and Z) Marsh (1), and Wilder (26).

§ 86. The metapodials are comparatively simple elements. In the
diagram, the pollical (first) metacarpal is made shorter than the rest, as is
the case in the cat, and the primal (first) metatarsal is represented as a slight
rudiment, the remainder of it and the whole dactyl being absent, and hence
shown by dotted lines.

The ordinary digits and dactyls have each three phalangeal segments,
proximal, intermediate, and distal. The pollex has but two, and in those
Mammals which have a primus, this usually consists of but two phalanges.

§ 87. ‘This peculiarity of the pollex and primus has always constituted a main argu-
ment in favor of the prevailing view as to the correspondence of the limbs with each
other—intermembral homology.

According to this view, the cephalic borders of the arm and leg correspond, morphi-
cally as well as telically ; the radius is the homologue of the tibia, and the ulna of the
fibula ; and the pollex is both the homologue and the analogue of the primus,

This, the syntropical idea of intermembral homologies, has been adopted, in one form
or another, by nearly all anatomists.

The other idea, that of untitropy, has been advocated or accepted by a much smaller
number, including the elder Agassiz, Coues, Dana, Foltz, Wyman, and the senior author.

According to this view, the two ends of the soma, and thus the cephalic and caudal
aspects of the limbs, are reversed or symmetrical repetitions of one another, as are the cor-
responding organs upon the right and left sides. The radius thus becomes the homologue
of the fibula, and the tibia of the ulna, while the pollex represents the quintus, and the
minimus the primus.

Fully recognizing the apparent objections to this view, we nevertheless believe it to
be correct, and would refer those interested in the subject to the paper (10) by the senior
author, where these objections are discussed and the opinions of other writers stated,
with a List of Works and Papers treating of the general question.

§ 88. Enumeration of Parts in a Series.—As has been stated (§ 30,
79), two or more similar parts which form a series are enumerated in order,
beginning with the one nearest the head, or the meson, or the proximal end
of the more comprehensive part of which they are subdivisions.

On the diagram (Fig. 6) are given some illustrations of this method.
The vertebre have been referred to already. Of the digits and dactyls, the
most cephalic in each series may be designated as the first; but it is evident
that this might cause confusion in the case of animals having only four
or a less number of fingers or toes.

TRANSECTION OF A MAMMAL. 43

It is often desirable to describe the place of origin or insertion of muscles
as from or upon a given fraction of the entire length of a long bone. When
the area extends over a third of the whole length the thirds would be
designated usually as proximal, middle or distal; but when fourths or
smaller subdivisions are employed, they may be designated as jirst, second,
etc., as shown upon the femur in Fig. 6.

Dorsal aspect

canaNis neuralts

2.
< ss Ste
D r “es
_L--trachea
.-pulmo (lung) dexter
2 elbow.

cf ‘metacarpale

‘phalanges Ventral aspect 4

Fie. 7.—DIAGRAM OF AN IDEAL TRANSECTION OF THE THORAX OF THE CAT, WITH
THE ARMS IN AN APPROXIMATELY NORMAL POSITION, AND SHOWING THE
LOCATION OF THE PRINCIPAL VISCERA.

§ 89. In Fig. 7, the cut surface is viewed from the caudal aspect, so that
the right and left parts are as in the other diagram (Fig. 6).

As a whole, the body is symmetrical, the two halves being reversed repe-
titions of one another on opposite sides of the meson.

No definite separation exists between the dorsal and the ventral regions.
We may, however, speak of the dorsal and the ventral aspects, and the
vertebral column, or main axis of the soma, intervenes between the dorsal
cavity, or Canalis neuralis, and the ventral cavity, the celum, whose more
cephalic division or thoraz is here transected.

The Canalis neuralis contains the myelon, and the celum the organs of
organic life, the thoracie, abdominal and pelvic viscera.

The following parts and organs are mesal or approximately so, at least
in the embryo: nose, tongue, myelon, centra vertebrarum, aorta, esophagus,
trachea, heart, sternum.

The following are in pairs: eyes, ears, kidneys, costw, costicartilagines
(costal cartilages), pudmones (lungs), pleura, limbs.

The right lung is shown as a single and simple sack, communicating

44 INTRODUCTION.

with the trachea. The left lung is reduced to give place for the names of
the cavity.

Each pleura is seen to be a closed sack, which lines the corresponding
side of the thorax to form the ectal or parietal lamina, and is reflected upon
the viscera to form the ental or visceral lamina. Between the heart and
the sternum, on the meson, the two pleure are in contact, and form the
septum mediastinale.

For the sake of simplicity, the pericardium is omitted, and the heart
shown as a single cavity with regular walls. The single vessel emerging
from the heart will be referred to in § 91. ,

The spaces on either side, between the skin and the osseous walls of the
celum and Canalis neuralis are occupied by the muscles, etc.

The arms have their elbows directed dorsad, and the palms ventrad.
The caudal aspect is seen, the bones including the ulna and the ulnare (un-
ciforme), and the minimal metacarpal and phalanges.

§ 90. Relative Positions.—The letters A-L are introduced into the
diagram for the sake of illustrating certain common cases of designation of
relative position.

The point A is at the meson on the dorsal aspect of the body ; its posi-
tion may be described as dorsimesal. B, C, and D are lateral in position,
or, to be more specific, sinistral.

Relatively, B is laterad of A, while C is dorsad of D. Since they are
upon a curved surface, B may be described as either dorsad or mesad of O ;
while C may be said to lie either ventrad or laterad of B. Which expres-
sion should be employed would depend upon the context; in either case,
practically, there is no room for ambiguity.

Ectal and Ental.—Of the three planes represented by C, E, F, the
former is relatively ectal, the last is ental, and the third intermediate.

Proximal and Distal.—G is at the proximal end of the humerus, and
H at the distal end. G is thus proximad of H, and H distad of G.

Central and Peripheral. —On the artery, I is centrad a K, and K is
peripheral in comparison with I, but centrad of L.

On the nerve which leaves the myelon, M and N are relatively central
and peripheral.

§ 91. Use of some Terms of Relative Position in a Physiological
Sense.—Central and peripheral, and sometimes other terms are employed
in a physiological rather than in a strictly topographical sense.

For example, on the nerve the ventral curve is really, that is topographi-
cally, nearer the myelon and the meson than N ; but N would nevertheless
commonly be described as centrad of the curve.

A striking case of this sort is furnished by the recurrent laryngeal branch of the NV.
vagus. In a part of its course, it curves around one of the great arteries near the heart,
and then passes cephalad to the Jarynz. Now the larynx is much nearer the brain, where

THE SLIP-SYSTEM. 45

the WV. vagus arises, than is the heart ; topographically, therefore, the termination of the
nerve is nearer the brain than part of its trunk ; yet the termination would be described
as the peripheral portion.

On the artery shown in Fig. 7, ventrad of the bones of the left arm, K
is peripherad of I, and Lof K. If the arm should be so flexed as to bring
the artery into the position of the dotted lines, L’ would be topographically
nearer the heart than K, but would nevertheless be a peripheral point on the
vessel.

. A somewhat similar case is offered by the abdominal portion of the ali-
mentary canal as shown on Fig. 6. In the strict topographical sense, the
cecum and contiguous portion of the small intestine lie caudad of the colon.
In some cases, a description would refer to this fact, but it would be never-
theless understood that, physiologically and in respect to the course of the
contents of the canal, the cecum is intermediate between the small intes-
tine and the colon, and is therefore caudad of the one and cephalad of the
other. The relation in the one case is merely of contiguity ; in the other,
of structural and functional continuity.

V.—THE SLIP-SYSTEM OF NOTES.

§ 92. The following suggestions as to “notes” are here introduced not because, like
the foregoing matters, they render what follows more intelligible or available, but
because, taking for granted that none will have got so far in the volume without the
intention to do some serious scientific or literary work, we desire to put them in possession
of a method which has proved most useful to us, and which we shall be glad to have
adopted by our readers even if their only employment of it is in recording criticisms of our
statements and ideas.

§ 93. The essential feature of a ‘‘slip-system” is the use of separate
slips of uniform and convenient size.

Accessory features concern the precise size and form of the slips, the way
of writing upon them, and the manner of their filing and distribution for
reference.

§ 94. After constant use of the slips for fifteen and seven years respec-
tively, we make the following specific recommendations :—

§ 95. The Slips.—Excluding those used in the Catalogues of Libraries
and Museums (which will be referred to farther on) the note-slips should
be of wnruled paper ; white, blue, light brown or yellow in color ; slightly
sized, so as to take either the pencil or the pen ; moderately stiff, but not
thick ; and of the size of the U. S. Postal Card, at present 13x7.7 cm.

§ 96. Making Notes.—Some of these slips should be carried in the
pocket at all times, preferably in the pocket-book, which is usually large
enough for folded letters.

46 INTRODUCTION.

Temporary memoranda may be made across the slip, but all other notes
should be written lengthwise, and preferably on one side only.

§ 97. Slip notes are of the following kinds: museum catalogues; library
catalogues ; references ; extracts; clippings; statements of observations or
ideas, original or otherwise, with or without drawings.

§ 98. Library Catalogues.—The titles of books and papers should
comprise at least the following data: the author’s name and surname or
initials ; the title and subtitle of the book or paper. With a book, the edi-
tion, size, number of pages and illustrations ; the place and date of publica-
tion. With a paper, the Periodical in which it was first published, dates of
presentation and publication, the volume, part, pages and illustrations. With
both, references to Translations and Abstracts.

The foregoing data are entered in various orders, and with different kinds
of abbreviation. ‘Those who desire to adopt some standard method of writ-
ing titles should consult the ‘‘ Catalogue of Scientific Papers” published by
the Royal Society of London, the publications of “'The American Library
Association,” and the “List of Periodicals taken by the Public Libraries
near Boston.”

A. One of the valuable suggestions of the Library Association is that the more com-
mon given names should always be indicated by the initial, this initial being distinguished
from the same letters used elsewhere by a colon following: For example, E. might stand
for Edwin, Egbert, Edmund, etc., but E: would always signify Edward. .

B. Another suggestion, that the sizes of books should be indicated not by numbers
but by the initials of the words signified by the numbers, as O. for octavo, etc., is carried
out in the “ List” just mentioned, and is made more available by the use of the “ Book
Size Rule,” provided by the Readers and Writers Economy Company, being a metric
rule, 30 cm. (1 ft.) long ; this is also a convenient desk rule.

§ 99. Catalogue Data.—On the face of the Museum Catalogue Card
should be noted the following : Museum number, original number, class (of
animals), series (of specimens or preparations), genus, species, common name,
locality, sex, age, dates of collection, death, and reception (which do not
always coincide). This should leave the lower half of the face for a brief
description of the preparation ; purpose for which it was made ; reference to
any original list, to publications, ete.

On the reverse of the slip should be, after a repetition of the museum
number: the original weight of the brain, and of the body, and the ratio in
decimals; the present (usually alcoholic) weight of the brain and body; the
capacity (of an inflated preparation); the length from vertex to anus (of an
entire example); by whom collected; when and by whom prepared ; donor
or seller; his address; original cost, expressage, etc., hours’ work; estimated
present value; museum numbers of other specimens from the same indi-
vidual ; numbers of other preparations from members of the same litter ;
numbers of other specimens with which this may be instructively compared.

HOW TO TAKE NOTES. 47

With care in the arrangement and abbreviation of these points, all may be entered,
together with others not here specified. We have not yet fully determined upon the
best form for the Catalogue slip, and hope others will offer the results of their experience.

For library and museum catalogues, the slips should be of heavier and stiffer paper
than for ordinary notes, and the surface should be well-sized, since ink is commonly
employed. °

§ 100. References.—The slips may be used for brief references to
works, papers, persons, addresses, localities, museums, etc., constituting, in
fact, permanent memoranda, which may be filed with more elaborate or
extended materials upon the same subjects.

§ 101. Extracts.—Upon one side of the slip may be written from 40 to
50 words, either by hand, or with the type-writer when the lines are at
medium distance, 1 cm. apart. At short distance, the number is just
doubled, and, if necessary, both sides may be written on, or two or more slips
may be used, or a sheet may be used, and then folded to the slip size.

§ 102. Clippings.—Clippings from periodicals and newspapers ‘may
often be accommodated upon the slip. When no longer than the slip is
wide, they may be pasted at either end, with the lines always lengthwise of
the slip. When the length is greater than the width of the slip, the columns,
if narrow, may be pasted side by side; but usually so much as exceeds the
width must be pasted on the remaining space so that the lines run across the
slip. By thus covering both sides, a single slip may receive an entire column
of “The Medical Record,” or “‘Science;” more than half a column of
“The Nation,” and nearly half a column of the ‘‘ New York Daily Tribune.”

Even when unaccompanied by the signature of some well-established
authority, such clippings serve as memoranda which may aid in looking up
the matter farther, and as more or less valuable confirmatory evidence.

§ 103. Notes Proper.—The most common and most important use of
the slips is as a ready and convenient vehicle for the many kinds of informa-
tion which the scientific or literary worker desires to record and to use.

The Slip is Always at Hand.—\t may be written upon without
parade, and under almost any circumstances, whether sitting at the table, or
riding in the cars, or even on horseback; whether engaged in regular
work, or conversing with friends, or even at night and in the darkness.
Under all these conditions, more or less favorable, the essence or “pith” of
a fact or idea may be recorded, though sometimes in a shape quite unintel-
ligible to others and well-nigh so to the writer, unless an early opportunity
is taken for putting it in better form.

§ 104. Accumulation and Elimination of Slips.—The beginner’s
object is to accumulate the brief records of what he has learned, but is not
sure of remembering when wanted.

After the first year, however, many of the things thus recorded become
familiar as the alphabet, and much also that is supposed true to-day may be

>»
48 INTRODUCTION.

disproved to-morrow, or superseded by more accurate descriptions, more
perfect drawings, and more logical discussions.

With the ordinary note-book, or Index Rerum, all these untruths,
half-truths, or truisms must forever remain where they were placed. From
being merely superfluous, they soon become burdensome, then confusing, and
finally a source of loss and exasperation.

Not so the slip; the instant its usefulness is at an end, into the waste-
basket it goes, making room for more desirable successors.

§ 105. Arrangement and Storage of Notes.—After trying many
different plans, we make the following practical suggestions :—

§ 106. Slip-Portfolios.*—The slip-portfolio is for holding the notes
upon a given subject.

It is made from a piece of stiff Manilla paper, 16 x 13 em., and folded over
a pencil so that the folded edge is left rounded. The slips are introduced,
the title of the subject is written along the top, and the whole is bound
together by arubber band 7 cm. long by 1 mm. thick, like No. 372 of the
Price-list of the R. and W. Ec. Co.

Such a portfolio will hold 50 slips, but usually when there are more than
25 they should be subdivided.

§ 107. Subdivision of Notes.—Let us suppose that the student is
collecting information respecting the heart of the cat. While his notes are
few, all may be contained in a single portfolio. As they multiply, they
naturally fall into four categories relating respectively to the structure of
the organ, its functions, its development, and the titles of works and papers
treating of it. As the notes increase under each of these heads, anatomical
notes may be divided naturally into sets relating respectively to the appear-
ances which are visible to the eye, those which require the aid of the micro-
scope, and those which involve special kinds of manipulation, as boiling, etc.,
in order to display the arrangement of the fibers. The macroscopic anatomy
may refer to the auricles, the ventricles or the valves, and each of these
headings may be still further subdivided.

We see, therefore, that without the subdivision of the notes upon five
quite extensive topics, the heart might require the use of a dozen separate
portfolios. Since all of these concern the heart, they may all be bound
together by a stronger band, say No. 385, 8 cm. long and 3 mm. wide; or,
they might be bound in two sets, the one including all the divisions of the
gross anatomy, and the other the rest.

Such a plan of subdivision is not only convenient for reference, but
furnishes an exercise in Natural Classification ; see p. 49, § 108.

§ 109. Distribution.—Since it is not always convenient to assign the

* The employment of the portfolios was suggested to us by Wm. Nichols, M.D., of
Boston, Mass.

49

OF NOTES.

SUBDIVISION

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50 ; INTRODUCTION.

notes to their proper places at the time they are made, it is well to have an
extra portfolio, which, in this case, would be marked, ‘‘ Heart of Cat;
- Distribution.” .

When its contents are to be distributed, the other portfolios are arranged
upon the table in some natural order; the removal of their bands will
permit the upspringing of the side so as to expose the heading, and facilitate
the introduction of slips.

§ 110. Slip-box.—This should be of stout tin, preferably Japanned.
The inside measures of length and width should be 22 cm. x14 em. (about
9 x 5.5 in.), which is nearly the size of the ordinary sheet of note paper.

The depth is less simply stated. If the box has a folding lid, like the

*‘ Japanned tray, postal size,” here figured (Fig. 8), a depth of 8 cm. will be
needed. But the scientific student has such abundant need for shallow
trays, that he will usually find it more convenient to have, in place of the

folding lid, a single cover, 2 cm. deep. This should overlap the edge of .

the box for 1 cm., resting on a welt. The depth of the box itself will then
be only 7 cm.

If the slips are kept in envelopes instead of portfolios, the box and
cover together should have a depth of 9cm. The Japanned tray, “standard
size,” is only 5cm. deep, and if the “ postal size ” is ordered, care should be
taken that it is of the actual width required for the postal card, since some
the of so-called ‘‘ postal slips” are only 12.5 em. long.

The free edges of the box and cover should be turned, and the latter
should be ‘‘ wired.”

§ 111. Cost of Materials.—The tin box may be had for from 50 cents to $1.00. A
tin cash-box, with lock, costs $1.50. The Japanned tray, postal size, with slips, blocks
and guides, is $2.65.

“Roll Manilla,” 40 inches wide, is 8 cts. per yard; including the cutting, the slip-
folios cost at the rate of 10 cts. for 25-35.

The bands are rated at $2.20 per M. for No. 872, and $5.85 for No. 385. By the hun-
dred they cost proportionally a little more.

The slips may be cut by hand, but it is

“usually cheaper to have the cutting done
by the stationer. They cost from 50 cts.
to $1.00 per M.

$112. Other Methods.—The slips
may be placed in envelopes, sealed at the
side, and with the right end cut off. If
this plan is adopted, it is true economy to
use stout envelopes which will not readily
fray and tear. Cloth-lined envelopes of
the proper width, 9 cm. (three and one-half
inches), may be had for about $2.50 per
hundred, and are practically indestructible.

Another way is to write the heading
upon a card the size of the slips, and put

Fic. 8.—THE JAPANNED TRAY, FOR CATA-
LOGUE Sires. READERS AND WRITERS
EconoMy COMPANY.

PREPARATION OF MANUSCRIPT. 51

the band over all. Finally, there is the method exemplified by the accompanying figure
(Fig. 8), which seems, however, better adapted for museum and library catalogues.

§ 113. Using the Slips.—For ordinary reference, the portfolio is held
in the left hand, the band removed, and the slips turned until the desired
one is found.

As a basis for manuscript or lecture-notes, they may be arranged in the
proper order by spreading them out upon the table; more or less condensa-
tion and elimination will then occur. The selected or condensed notes may
be used as lecture-notes, or their substance transcribed to sheets:

§ 114. For carefully prepared manuscript, the following stages of com-
position are recommended :— -

1. Slips, hand-written. 2. Slips, selected, condensed, and, if possible,
type-written. 3. Sheets, hand or type-written, into which the type-written
slips may sometimes be incorporated by pasting. 4. Sheets, carefully type-
written, a corrected copy of the first set.

Manuscript so prepared, especially if in addition an interval of at least
one week elapses between the first and the second copies, will usually need
few changes in proof.

§ 115. Sheet-Portfolios.—The sheets referred to are of the standard
note size, about 21 x 12.5 cm. Such
sheets and drawings of similar size may
be conveniently kept in sheet-portfolios of
the Manilla paper, double the size of the
sheet, say about 21 x 27 cm.

Portfolios of sheets, or the sheets
themselves, may be conveniently kept in
the “Pigeon Hole Case,” “ pamphlet
size,” supplied at $1.50 by the R. & W.
Ee. Co. The case shown in the figure dua Pisco Hoke Oakes} oer
is known as the “Billet size.” For ied Shaken ee Wapediin TOG.
“note sheets,” there are only two tiers of nomy Co., (A.)
holes.

Fie. 9.—UNIFORM, INTERCHANGE-

$116. Miscellaneous Suggestions.—A. By writing the portfolio headings with
pencil, they may be changed as desired, and to any extent. Even if written with ink or
printed, however, each portfolio presents four surfaces which may be used in turn.

§117. B. The type-writer or calligraph can be adjusted to any width of paper. Of
course, the longer the line the fewer the shiftings ; but the narrower sheet is more easily
manipulated, especially when changes or divisions are required, and it is often a real ad-
vantage to be able, without delay, to write alternately upon the sheets and the slips.

$118. C. While assorting a large number of slips for which portfolios have not been
prepared, it is sometimes desirable to remove them all without mixing the separated piles.
This may be accomplished, either by interposing a blank slip between the successive piles,
or by placing them crosswise, and carrying a band over them diagonally.

52 INTRODUCTION.

§ 119. Origin of the Slip-system.—It is probable that the slip-system
has been devised independently by many individuals, and we are informed
that Mr. Folsom, the Librarian of the Boston Atheneum, proposed the use
of slips in Card Catalogues at the Librarian’s Convention in New York in
1852. Asa means of recording and arranging scientific information, how-
ever, the first published notice known to us is the following by the senior
author (177), communicated to the Boston Society of Natural History,
May 15, 1867 :—

§ 120. “It consists in the brief statement of facts, ideas, or references
to books, written upon one side of a slip of paper equal to the sixth part of
a sheet of note paper.

“A few of these blanks are carried in the pocket, and advantage is thus taken of op-
portunities for recording and preserving information which the time, place, or state of
mind would not permit to be written out in full, or which might be forgotten before a
fitting opportunity should occur.

“ These slips are distributed at leisure into envelopes bearing the title of the subject.

“ By keeping the slips separate, it is evident that an indefinite subdivision of each
general subject can be made by simply increasing the number of envelopes and redistri-
buting the slips.

“The slips may be used either for simple reference, or, if in preparation of a lecture
or communication, by arranging them on the table in any desired order, and transcribing
parts of them in the form of notes; while for a written paper they serve to indicate the
general order of discussing a subject.

“The method proposed makes sure of the essential fact or idea in a brief form, and
the slips, being kept separate and of uniform size, may easily be arranged, carried and
arranged, or rearranged in any order at any time.”

This plan was presented in a lecture at the session of the Anderson School of Natural
History on Penikese Island, in July 1873, and, according to a report in the N. Y. Tribune,
“was almost universally and immediately adopted.”

§ 121. Rules and Aphorisms of General Application.

“In the order of Nature, doing comes before thinking; Art before
Science ”—Joseph Henry (Mayer, 1, 95).

** Personal familiarity alone makes knowledge alive.”—Philip Gilbert
Hamerton.

** Practice the utmost rigidity and thoroughness in research, without
regard to time consumed, or value of results.” — Henry James Clark (Pack-
ard, 1).

“ Lenteur dans la marche; aridité dans Vétude; solidité dans les prin-
cipes ; stireté dans les résultats; ce sont ld les attributs des sciences d’ob-
servation.” —Bichat, A, i, p. v.

Correct methods are the keys of knowledge.

Whoever has learned how to work has taken a long step toward indepen-
dence of teachers and books.

APHORISMS OF GENERAL APPLICATION. 53

«The method may determine the result.” —Louwis Agassiz.

*<Tf researches take at the first step a wrong direction they diverge the
farther from the truth the farther they are followed.”—Gaboriau.

“Tt is often as if the truth were rather whispered than spoken by
Nature.”—Owen.

Accuracy is more to be desired than speed.

Books may be consulted in haste, but Nature demands deliberation.

Non-discrimination is no proof of identity

Ignorance of a specimen’s locality may cause delay ; an error respecting
it may create confusion.

As is the locality to an individual, so is the individual to any of its parts.

“There is so close a solidarity between ourselves and the animal world
that our inaccessible inward parts may be supplemented by theirs. * * * A
sheep’s heart or lungs or eye must not be confounded with those of man ;
but so far as the comprehension of the elementary facts of the physiology of
circulation and of respiration and of vision goes, the one furnishes the
needed anatomical data as well as the other.”—Hualey, 3.

* Carpenters and tailors do not learn their trades upon rosewood and
cloth of gold.”— Wilder, 2, 8-

“ Felitomy should be the stepping-stone to anthropotomy.”—Jdem, 2, 6.

“No medical student should be allowed to dissect the human cadaver
until he has familiarized himself with the anatomy of the cat.”— Cleven-
ger, 1, 1.

He who can skillfully dissect a cat will find little difficulty in dissecting
a man.

“ Fiat experimentum in corpore vili.”

The softer the parts, the harder their study.

Soft parts are perishable.

Hurried dissection is rarely trustworthy.

The thorough examination of soft parts. can be made only under one or
more of the following conditions: A. Limitation of the inquiry; B. Abun-
dance of material; C. Continuity of dissection ; D. Co-operation of several
dissectors ; E. Preservation of the parts.

Filth and bad odors cannot always be avoided, but their continuance is
rarely necessary.

Accurate knowledge of a few things is better than vague ideas concern-
ing many.

First expressions are rarely correct or perfect.

A description is perfect only when it enables one who has never seen the
object to form a correct image of it.

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ANATOMICAL TECHNOLOGY.

INTRODUCTORY.

§ 123. This work treats mainly of the Gross Anatomy of certain
: portions of the Domestic Cat, and of the Methods of their Examina-
tion and Preservation.

Reasons for Selection and Preference.—There shall be given
here a condensed statement of the reasons for selecting the Cat, for
giving almost exclusive attention to the Cephalic region of the body,
and for devoting to the Brain and other Viscera a relatively large
amount of space.

§ 124. For Selecting the Cat.—Three things are to be learned by —
the student of Anatomy and Physiology, whether Human, Veteri-
nary or Comparative: methods of manipulation; fundamental facts
of structure and function ; and terms of expression.

Most of the methods might be learned upon any mammal, but
convenience and economy are consulted by the use of one which is
at the same time widely distributed, common, easily kept in con-
finement, and of moderate size so as to be readily manipulated and
cheaply preserved.

Methods cannot be practised without some knowledge of the
nature, location, and uses of the parts concerned ; and the record or
communication of results involves the use of terms; hence there is
effected a substantial saving of time, mental effort and expense by
employing, in the acquisition of methods, a form anatomically and
physiologically comparable with those which the student is pre-
paring himself to investigate.

The adult human subject is inconveniently large, not always easy to obtain, and often
expensive when all things are considered. The immature individuals (still-births) which

56 INTRODUCTORY.

may sometimes be had, lack the firmness of texture which is desirable for the examination
of certain parts.

The veterinarian is especially interested in the horse and the cow; but these are too
large and costly for elementary work ; in less degree, the sheep and the pig are open to
the same objection.

The needs of the comparative anatomist were well expressed in the course of a “ Labora-
tory talk,” by the late Prof. Jeffries Wyman, as recorded by the senior author (2, 5):—

“Tn commenting upon the unsatisfactory nature of some published notes of dissec-
tions, he said : ‘Much of this is due to the lack of suitable standards for comparison. The
human body is not a suitable standard for the lower vertebrates. The best thing any
anatomist can do is to prepare complete accounts of the structure of a few forms, each
typical of some large group. The fowl] could represent the birds, and the cat the mammals.
The cat’s anatomy should be done first, because it would also serve as an introduction to
Human Anatomy, and thus become an important aid to Medical Education.’ ”

Theoretically, among known forms, the wants of the comparative anatomist might be
more fully met by the more generalized opossum or raccoon. The tiny musk-deer of Java
could be more easily dissected and preserved than most of our hoofed quadrupeds ; while a
medium sized monkey, especially after some confinement, is the best possible substitute
for the human subject.

Unfortunately, however, none of these animals is sufficiently abundant in all parts of ©

the civilized world, and we must select such as are to be had. The rat is certainly too
small for most purposes, and not easy to obtain unmutilated. The rabbit, like the rat,
belongs to a group of peculiar mammals, the Rodents, with no special advantages in
respect to either human or veterinary anatomy. Dogs vary greatly in size and mode of
life, so that no one of the many breeds can be fairly spoken of as the dog, and although,
as stated by the senior author (21, 308), the pectoral muscles present less variation
than might be expected, few comparisons have been made of the other soft parts except-
ing the brain, where, as regards the disposition of the cerebral fissures, the variation is
considerable and perplexing (Wilder, 12, 242).

So far as we can judge from published records and our own observations, cats are much
less subject to variation than dogs. They are both walkers and climbers, and therefore
comparable with the domestic quadrupeds on the one hand, and with the monkeys, and
through them with man, on the other. They are common in most civilized lands, fertile,
easily reared, and may be kept in confinement, even in considerable numbers, without
difficulty. They quickly succumb to anesthetics, and their size is such as to facilitate
both dissection and preservation in alcohol. They are quiet, while dogs are noisy.

§ 125. Of aless practical nature, yet well worth mention, is the remarkable combination
in the cat’s organization, of delicacy, agility and strength ; a combination which seems
almost perfectly adapted to the prolongation of individual life and the perpetuation of the
species. Indeed, as well remarked by Mivart (B, 493,) ‘‘Something may be said in favor
of cats being the highest of mammals, if man is considered merely in his animal capacity,
in which alone he can be brought into comparison with other organisms.” See also
Minot, 7, and Dana, 123, 160.

This idea will be acceptable to those who prefer the purely teleological aspect of Nature.
Others, however, may find ample ground for discussion respecting the universal operation
of the doctrine of Final Causes, at least in the present state of our knowledge. Teleology
has not yet explained the existence of the insignificant clavicle, the rudimentary primal
metacarpal, the little pocket at the border of the ear, or the cusps on the deciduous map-
dibular canine teeth.

§ 126. In short, while freely conceding the advantages which might be presented by

INTRODUCTORY. 57
other forms, especially if it were practicable to supply a separate standard for the anthro-
potomist, the zoologist and the veterinarian, we nevertheless believe that even then
these three might be advantageously compared with the cat as a fourth and intermediate
form, and that, when all points are considered—size, habit, distribution, physical endow-
ment and zoological position—the cat should be chosen over all others, both as a single
standard for comparison, and as a subject of elementary and preliminary anatomical and
physiological work.

§ 127. Nor is this choice wholly without precedent. It is true that descriptive and
practical works upon Mammals have been more often based upon others than the cat. For
obvious reasons, the horse has been the subject of many publications ; the rabbit is selected
by Krause (A), the rabbit and the dog by Foster and Langley (A), the rat by Rolleston
(A) and Morrell (A), while Coues has described (47) the skeleton and muscles of the
opossum.

Yet Straus-Durckheim devoted a magnificent monograph to the bones, ligaments and
muscles of the cat ; and reduced copies of his outline plates, with a translation of the
“ Explanations,” have been published by our colleague, Prof. Henry 8. Williams. The
skeleton is delineated and named, in connection with those of the Duck and the Codfish,
by E. Tulley Newton (A), and as the work was “prepared under the supervision of
Prof. Huxley,” the usefulness of the cat has probably been appreciated by that zoologist.
Finally, the recent volume by Mivart (B) purports to describe the entire structure of
the cat, although no practical directions are given, and, according to notices in The Nation
for June 2, 1881, and in Science, and The Athenwum for June 4, the author seems to have
made somewhat frequent and wholly unspecified substitutions of human anatomy for that
of the cat.

The junior author has published two papers (7, 3) upon the anatomy of the cat ; and
the desire: for a complete account of its brain, expressed by the senior author in 1873
(11, 229), has been recently, in part, fulfilled in the papers numbered 2, 3, 4, 5, 6,
7, 8,9, 12, 13 and 14.

§ 128. Reasons for Treating of only Part of the Body.—This
work is primarily an explanation of methods, and the descriptions
of organs are mainly in illustration thereof.

The account of only forty muscles covers an equal number of pages. To devote a pro-
portionate space to the 150 or more other muscles, and to all the arteries, veins and nerves
would swell the volume to undesirable dimensions. Some selection was therefore neces-
sary.

Of the two general regions of the body, the cephalic is certainly more familiar to most
persons, more interesting, more employed in art, more often used in experiment, and more
subject to injury and disease. To obtain and prepare the heart and the brain involves
some manipulation of the thorax and head.

The arm of the cat is more complete than the leg, since it has all five of the digits,
and presents the interesting and important provision for the rotation of one of the epipodial
bones about the other.

Notwithstanding our doubts respecting the homologies of the M. clavo-trapezius and
some of the antebrachial muscles, the myology of the arm is in a more satisfactory state
than that of the leg, where the great ‘‘adductors” are likely to puzzle anatomists for
some time to come.

In short, the same practical considerations which have led most anatomists to describe
the muscles of the antebrachium with more fullness than those of the back, have induced
us to select the arm rather than the leg for the more detailed descriptions.

58 INTRODUCTORY.

§ 129. Reasons for Giving Unusual Prominence to the Vis-
cera.—It is stated by Macalister (British Association Report, 1877,
p. 94), that ‘‘at least 600 bodies are annually examined in tlie dis-
secting rooms of Great Britain and Ireland;” yet how few are
the published observations respecting the characters, constant or
variable, of any parts other than the bones and the muscles. In
this country the case is still worse, and we have no journal espe-
cially devoted to Anatomy and Physiology.

This comparative neglect of the internal organs is probably due, in great part, to the
fact that, as remarked by the senior author, (2, 9), the average “ human subject is rarely
available for the study of viscera. Usually some of them are diseased. The heart is apt
to be full of injection-mass. The brain and abdominal viscera decay so rapidly that some
of their important features are soon obliterated ; and when, as is customary, their removal
is postponed until after the examination of the overlying muscles, their condition is often
such as to render them unfit for preservation. How many students have gained a good
view of the thoracic duct, or the sympathetic ganglia? How often has it been ascertained
whether a subject has two pancreatic ducts or only one? Is a satisfactory examination
of the brain made by the majority of dissectors?” In short, do not the larger number of
medical students regard the viscera, even the heart, as simply a mass of ill smelling
material, difficult to examine, not very instructive, and worthy only of the waste pail?

Whatever be the cause of this inattention to the viscera, the fact leads us to give
ample space and illustration to these organs as they exist in an animal peculiarly adapted
for their study and preservation. Moreover, although a predilection for surgery prevails
among medical students, most of the diseases they will have to treat affect the viscera
rather than the skeleton and its muscles; physiology, too, is largely splanchnological, and
a correct knowledge of the brain is yearly more desirable in connection with the pro-
gress of rational Psychology.

Lastly, notwithstanding the general preference of. systematic zoologists for skeletal
characters—a preference certainly based upon convenience, and, in respect to fossil forms,
upon absolute necessity—we are disposed to think, as suggested by Gill (J, p. xxvii)
and the senior author (22, 189), that the more comprehensive vertebrate divisions should
be founded upon cerebral and cardiac characters.

CHAPTER’ TI.

LIST OF INSTRUMENTS AND MATERIAL FOR ANATOMICAL TECHNOLOGY—DESCRIPTION
OF INSTRUMENTS AND APPARATUS—CARE, POLISHING AND SHARPENING OF INSTRU-
MENTS—METHODS OF KILLING ANIMALS—PRECAUTIONS FOR CLEANLINESS—DEO-
DORIZERS. /

§ 130. Anatomical Instruments and Material—tThe follow-
ing is a General List of the Supplies required for anatomical work.
A Special List will be given in connection with each kind of manipu-
lation. :

The names are arranged in alphabetical order. Common letters are used for the names
of instruments and materials which are desirable, especially in a large laboratory. The
names in black letter are of articles which are regarded by us as indispensable to the
performance of the best kind of work. :

Several articles are not marked indispensable because for them may be substituted
others which, although less perfect and satisfactory, may be cheaper or more easily
obtained. For example, ordinary cotton may be used instead of the absorbent, a pail or
box in place of the anzsthetic-box, crockery instead of glass, etc. Of the two syringes,
the cheaper is marked indispensable, but the more expensive will answer the purpose more
conveniently.

In the first column are given the numbers of the figures of the instruments and appa-
ratus in this work. In the second column, the sections are named when possible. Usually
these sections occur within the present chapter, but in some cases, as with Alcohol, Jars,
etc., the articles are treated of elsewhere, as may be ascertained from the Index.

In the last column are given the maximum prices of the less familiar articles. They
are usually taken from dealers’ lists, and are therefore based upon the ordinary weights and
measures. It will be understood that prices vary according to the quality of the goods,
the state of the market, and the distance of the dealer from the place of manufacture.

Illustrated Catalogues of Anatomical and Surgical Instruments, of Tools, of Glass-ware,
and of Chemical Apparatus and Supplies, may be obtained of dealers, as, for instance,
Codman & Shurtleff, of Boston, Shepard & Dudley, of New York, and Snowden, of
Philadelphia ; A. J. Wilkinson, and Goodnow & Wightman, of Boston ; Whitall, Tatum
& Co., of New York ; J. & H. Berge, of New York, and others.

ARTICLE. ‘ Fie. SxEc. PER PRICE
Absorbent/cottonns oe. thes eee Host eeeaeug an 134 lb. $1.00
AlCOuOL Cthgliy cass, tas caters onc coche stress = ch. III gall. 2.50
Alcoédmeter (alcoholometer), or hydrometer.... be: “ft 2.00
Avisesthetic-D0k. 860s ites ae inset vetoes 29 194 ae 1.50
Annvial Charcoal acct ees) Use etterane canes as 198 Ib. 10
Arsentate Of SOURS. i soyls selelslesslfaviveseseatre ye ch. III Tb. 20

AItRLOlOmie i ease oe eek Baeene ne eee 16 135 eit 1.25

60 ANATOMICAL TECHNOLOGY.

ARTICLE. Fig. SEc. PER PRICE
Atomizer or spraying apparatus....... ....... 2G is ae 1.25
Bags, coarse, for cats....... qaerers dene re tenes
SOHINE,, ATANILOWATO. wiois 20.05 wesl> sieates pase Js ed 5
PROG DUIStles: 6:5. bis aces a Saco ae eiteelrets ag 136 :

BREE: § noc 3'h bs bie clonic Hobie cee Re ee ashe Peale E

Bistoury, concave, blunt point................ 1.25
“sf small, straight, blunt point.......... 14 1.25

Po ve Ae sharp point . oy rs 1.25

pnne. 4 O32 X 0 OND. iene wrote Hate caitmie sc sane hae a 137 ‘

mow, Pine, flexibles ici ori. x1es,s nce aS anteee ss 19 138 25

PSOHGLORIBEN «4:6 :5)0\01s wis, sie eio-o lb Wiahd Vi ohals SERN. 040 Shale oe sg se 1.00

PSOUULE SLUSOS i. 1c'in ele vies bisiestele ube be ain dese 34 a doz. 2.00

Butcuer Knife, small. ..6s4 kwiwscceces ures ‘as sre 50

Cansjand ‘boxes:..metalincces bak. io Sie eee 3 ch. III

RMR, PARE 5 x5 wicks sSNA coins s owinie owt o.8 36

AEDOliC ACIGS BUOUE soc. oS elanis.s coe ans acc nas os a

BRCSS irs CANES ree a cfole va oe pe ek ais kins ave ‘? 139 af ye

RCDATAE NOUR D vet isu isie eis laee SS wits aisiwie «Ge 0 Hers . 140 eerie 50

CHAMOIS LEBER EPs i4.o.c-4 eset Mose here SW a we 5 weiss Ys ite ass o a

Chloroform... ........ db srd VB Isp ox eiatele ptavsgce ier cs <% Ib. 2.00

ROW ONO fst cls aca iene cisip 31d Rio le Bi bi sseteva ht Subse rr até = a

COB HECSAGE- SMB 85 os. seis ow ccs wicwieiee.c.es +e 13 141 pair 8

RSOEES, -ABROTUO 16 a c¥ occas bai ole De aardals Nala Ss

SER IT OION 6555 shied aaialls s Ris wie SRR Maeno ee

Cosmoline or vaseline... .... 2.26... e cence eee

Corton,, COMMON:.f. 555. ss ss Sneha sk slash Nielanete

MRSQMORIZOTE |) <50%s a ais aie gist ore ol Sistas alee aa aia ws ES ar sk

MIShOS PIASE COV ORO «0's sive ocak seis se saeis o's 33 ch. III doz. 3.80

MIGACCH NT OWN coat ce odes coe kaieaw esse oe 142

Drawing materials... << 66 siisi\.cindecscisee eles % 143

TEINS BNGMEOCK piase Cvrctic a Sas dowkwad oeu'eas s 144

BM GTY,, TIN GB barat este a cies harsis tam Siae ee eig Owe a tol $4 We

MRPUDYOLOING £5 aielars Saisie odes Shiels sw Beeus gels a om 159 ry a

Ether, sulpharic). 3.0.05 socio. eeidk Sate hen a® ie es ve 2.00

ORR MR Va oop oka] sn weyvc atin oSaoe Blah Nar BA new 3 Ss ve 5.00

Pr OGiE MALO. 5 o's sa 2 ite loca nme Ot taa euler eters Bets Rp oe ae: 25.00

Forceps, coarse............ IGA ia she due ay 18 145 4 1.00
“s fine, curved....5S.45s,. Wan. foe Sa ewee 20 146 bis 1.25

CAIVOOFIN, COMMON, 6s ..5/, . ieu's - Tele alec vss weeded sik “a ib. 50

PIERO OARS 5 cia ccs Siasiewlnh a vse ele ot a: sd

Hone, finest Arkansas oil-stone............... ie 184

Hone, medium...... ee TS ee Cet a 184

Hydrometer jar, 12 x 2inches................. s ch. Ill

Injecting materials, colors, etc............. si ch. IV

ENSUPUINONG PARCAT to ks Ge cesses a. ch eeviskea a = 171

Jars, glass, wide-mouthed..............22206- me ch. III

Knitting needle, smallest..................--

Lamp); sBUnsen OF-Bpirit fess vis. ss os os eee ys

Metric rule, weights and measures......... * 13

INSTRUMENTS

ARTICLE.

aalin, Cheap vio. <fscs chavectegucer ice.
Mas DIUShls vs ves cers eek, Coen eiexar ens
Needles, post mortem..........eeeee cere
Nippers, large and medium..............

Nippers, small, Stubs’s.............-..

PER els mah so cicacrata w 5 0 cee ae 8400 tient ely
Oil, olive or sewing-machine............

Oiler, glass or metal. ...... 2... ee ee ee eee

Parchment for labels.........-........6.
Parchment numbers.........0eecseeeeees
Permanganate of potassa..... ... ....4+-
Pins, assorted, and ribbon................
Minster aches yecs cists ots, seble sok aie wasrors
Plaster of Paris, finest dental .. ......
Pliers, round nose, 5-inch................
Probe, silver, with eyelet....... ........
Houce; JOweHer sine <cciccst scenes sees
Rubber bands, assorted........... ......
IRUDDGE IELOVOR ur, sg Reve obcavece’s 4 stee 4 ate ne eer
Rubber: shootings... cia dins ows eave een
PRMD POM Ti ING io) cua! eet e afeldee a hate eure soa?
Saw. DACK, SMall.-.t.cac sebes ap eee pees woe
Scales, large and small...................
Scalpels, large, medium and Charriere...
Scissors, coarse, curved flatwise.......
edgewise......

“e

Scissors, 4
a5 medium, curved flatwise

Sodium chloride (common salt).........
SBOE BIN os 550 ol sia'vs) Ges were cle RWS

ENON LALO. cece lo hice nes ros ams Ble tie

Se” oT MEMtES MOK) 323 eee. A ica eS
By PIRMOLGINGS a inosine wig alsin de wed beteebiee 62
Dees FOr LACS oe Sinca ss, « coke Cae sie sc bs
Penaewints cid cicuieyh als sca wisee S aaSiare ne aiaisl sae
Tools; carpenters. s clave. eves ove ees coe
Towels, fine crash, 45 x'70cm...........
Tracers, sharp and dull................
Trays, tin, copper, or wood..............
Priped, misguiflerys css cee Whease ens
Tabing, glass, small, 22.54 ..0e6 cares oes
Tunnels, fluted tube. ..........c.0 essen eee
Tarpentine; spirits.of;,..5.5.05 ass ieee enles

Twine and thread, linen. ..............

Ce

AND MATERIAN,

Fia.

"Se i
SG ape

wee,
eeee
sees

sees

se ee

eee

enee

eee

Syringe, brass, with canula...............
ae PUGDELLDULD Oo lst res os woe aes

AN 38

oop 15

eee

ema 17

ais 78

ence 26

eee

SzEc.

PER

50

62 ANATOMICAL TECHNOLOGY.

ARTICLE. Fig. Sxc. PER PRICE
Vials, large-mouthed... .......e.svessccsces i ch. Il
WEBLO POL; COVETOE 5 |... cosirncinsintie st bpiee' suse ss 196
WVBBGS PEAPCTS 6 i.) in.n videciaein daidwrns owth sais ae/awie ae 195 pas Fe
MMC PINOSES, 5 505 abs oa bales cateienmars “rs pt. I doz. 2.60
PROTA IOLLAG «520.5 55:5 asin BY Sis ic cine Sees Sp cantik 27 170

Wire, brass, copper and iron..............000.

§ 188. It will be seen from the foregoing list that the absolutely
necessary instruments for ordinary anatomical work are compara-
tively few and inexpensive.

In purchasing instruments, the student should remember that
their value depends not upon their handles, their finish, or their
cost, but upon the adaptation of their size, form and temper to
the work in view.

On the other hand, while perfect instruments alone will not
insure a good dissection, they are generally more easy to use, and
more durable. Hence 7 is cheaper, in the end, to purchase the
best.

Left figure, ordinary “cutting nippers.” Right figure,
“diagonal side cutting nippers,”’ called nippers in this
work. Middle figure, blades of nippers seen from the
side,

§ 134. Absorbent Cotton.—This is cot-
ton freed from all impurities, and especially
‘from the o¢/ which ordinary cotton retains
in small amount. It is therefore not
only cleaner, but capable of absorbing
water or alcohol instantly. On this account
it is to be preferred for the cushions which
are made for freshly prepared brains, em-
bryos, and other soft and delicate specimens to rest upon while
hardening. It should also be used for packing small or delicate
alcoholic specimens for transportation ; the ordinary cotton occupies
much more room at first than after it is thoroughly soaked, and a
space is thus left in which the specimen can be shaken to and fro.
When ordinary cotton must be used for either of these purposes, it
should be first thoroughly soaked. For dry packing, the ordinary
cotton will answer.

§ 185. Arthrotome—Fig. 16.--This' is a strong scalpel, two
edged for about 1 em. from the point. The handle is steel, continu-
ous with the blade, and roughened like that of the anthropotomical,
“cartilage knife.” The arthrotome should be used for the rougher

=

BOSTON

CODMANGSHURTLEFR

Fig. 10.—StTuss’s NIPPERS,
x 83; § 146.

BEADED BRISTLES. 63

wise.|

d edge

Iné scissors curve

Fig. iE

Fie. 11.—Niprers; x 1; § 146. German “ Side cutting Nippers.”
Fie. 12.—F rine Sotssors, curved edgewise ; x 1; § 156.

work, as cutting cartilages and separating arthra, so as to avoid
dulling and nicking the more delicate blades of the scalpels. Any
thick bladed scalpel may be ground into a tolerable arthrotome.

§ 186. Beaded Bristles.—These are easily made. Cut from a

64 ANATOMICAL TECHNOLOGY.

hair broom a bunch of the bristles, and select the longer and more
perfect ones. Cut off the split end so’ as to leave each bristle 5-7
mm. long. Melt red sealing wax in the flame of a lamp, and dip
into it the larger ends of several bristles at once; lay them down
separately and dip more until each has a bit of the wax. Then take
them one by one, hold them near the flame, and turn them between
the fingers so that the wax assumes the form of a small tapering
bead. These bristles are often useful in probing for slender holes
and canals, especially in the brain and other soft parts.

§ 187. Blocks.—These are of wood, well oiled, and with the
edges rounded. They are used for supporting the parts under
dissection, but a folded wet towel may sometimes serve the same
purpose.

§ 138. Flexible Blow Pipe—Fig. 19.—This is the whole or
part of the ordinary metallic blow pipe, with the addition of a
piece of rubber tubing 30-40 em. long. The blow pipe may be
filed in two, and the pieces used for finer and coarser work respec-
tively.

Unlike the short, straight and stiff blow pipe, this may be bent
in any direction, and the object inflated may be held at a con-
venient distance from the eye. Since inflation is temporary injection,
the advantage of witnessing the effects during the operation are
obvious.

A. The idea of attaching a flexible tube to the metal blow pipe was first suggested to
us by Mr. C. F. Clark, a student, in 1874.

B. A blow pipe of any size may be made by drawing a bit of glass tube to a point, as
in making a canula, and attaching the rubber tube.

§ 139. Cats.—The price of cats varies from five to twenty-five
cents. The owners of superfluous animals, especially of such as
are too old for usefulness or comfort, are sometimes glad to have
them painlessly killed.

The isolated student can usually obtain a cat when it is needed, but a laboratory must
keep several on hand. Contrary to general expectation, cats rarely quarrel in captivity,
and the fiercest of them generally become approachable within a few days. But the fleas
which probably infest all to some extent, seem to multiply more rapidly when several
cats are confined together, and some persons—though comparatively few—are annoyed by
them ; hence certain precautions should be observed.

If possible, the cats should be kept in a separate building. If they are confined in
part of a building otherwise occupied, the room should be isolated by double doors, etc.
The walls should be thoroughly plastered, or made of closely matched boards.

At least one window should be reached by the sun, and a raised platform should be so
placed that the cats can sun themselves on it. The windows should be covered with

CHAIN HOOKS. 65

strong wire netting, and always open a little at the top. In summer the ventilation
cannot be too free; in winter the room should be kept at a moderate temperature (10 to

15° C.).

At least once a year, the room should be thoroughly cleaned, and then washed with a
solution of sulphate of iron. Benzine should be poured or sprayed into all the corners
and cracks to kill the fleas, If possible, the room should be vacant during the hottest

months.

Shallow boxes of dry earth should be placed upon the floor, and the earth changed
frequently. Should soiling of the floor occur, the feces should be removed at once, the
spot well washed and saturated with some deodorizer, and then covered with a box. An
uncleanly cat should be promptly removed. The male cat is retromingent ; if one side of
the earth boxes reaches to the height of adout 30 cm. (about 1 foot) above the earth, the
walls of the room may be protected from their strong-smelling urine.

Cats like separate beds, which may be provided by placing boxes containing a little
hay or “ excelsior ” along the sides of the room, preferably at a little distance from the
floor. The cats are better pleased if half the top of the box is left upon it.

Fresh catnip should be strewn about the room occasionally when obtainable ; the dried
herb is a good substitute in the winter.

Graham crackers and water should always be accessible, milk should be supplied
daily, and meat once or twice a week. The milk vessels should be kept clean.

§ 140. Chain Hooks—(See Codman & Shurtleff, A, 43, Fig. 14).
—These are used for fixing or suspending parts under dissection.
In most cases, with so small an animal as the cat, these purposes
can be accomplished by the use of the ‘‘small compressor,” with
strings or straps of appropriate length. .

§ 141. Compressor, Small—Fig. 13.—This name is given to
what is known among dealers in wearing apparel
as the ‘‘Royal Garment Clasp, No. 1.’ The
spring which closes it is quite strong, and the
sharp teeth enable it to retain its hold under
/ considerable tension. By means of the eyelet,
Fic. 13.—Smarn Com. the compressor may be attached by a string’or a
pressor; x 1;$ 141, Strap to the loop at the side of the tray. For

some purposes the teeth may be removed.

§ 142. Dissecting Gown.—In some cases, the clothes are suffi-
ciently protected by an apron and pair of sleeves, or even by a
towel upon the lap. But generally, especially while injecting,
removing viscera, preparing bones, or performing experiments, one
should wear a gown of some smooth black stuff, like silesia. The
gown should nearly reach the ankles, and the sleeves should be
held at the wrists by elastic bands. It may open in front or behind,
but the duttons should be concealed lest they catch upon the edge
of a dish or jar. Soiling of the wristbands by the dye of the gown
may be prevented by facing the sleeves with white linen.

5

—— —=

| HI = = =
Fine curved forceps. Fig, 20.

—$——$$___—

-Syringotome. Fig. 15.

Arthrotome. Fig. 16
Tracer. Fig 7.
Coarse forceps. F ig. [8.
Flexible blow-pipe. Fie. 19.

Figures 14-20.—Various instruments; x 1. Blunt-pointed scalpel, § 155 ; syringotome,
§ 161; arthrotome, § 135; tracer, $ 166; coarse forceps, § 145 ; flexible blow-pipe, § 188 ;
fine curved forceps, § 145.

DRAWING MATERIALS. 67

§ 148. Drawing Materials.—These are required in all kinds of
Natural History work, and may be conveniently mentioned here.
In addition to the writing pencil, there should be at least two for
drawing, the one of medium, and the other of considerable hard-
ness. All pencils should be “hexagonal”? to prevent rolling, or
else provided with a hexagonal rubber eraser. For the neatest
work, however, it is well to use a separate eraser with a brush for
removing the crumbs from the paper. (See Readers and Writers
Economy Co., A.) It is so often desirable to double the size of
objects that the ‘‘duplicating dividers”? are more useful in place
of or in addition to the ordinary dividers. India ink is used for
some drawings and for writing upon parchment (see § 149).

§ 144. Drills.—A laboratory should have a foot lathe like, for
example, the one figured by Goodnow & Wightman, A, 73. But
most of the holes required in bone, wood or metal, may be made
by a small ‘‘ Hand drill,” like, for example, that figured on p. 14
of the same Catalogue. .

§ 145. Forceps, Coarse and Fine—Figs. 18, 20.—Both pairs
are absolutely necessary, and the fine ones should be curved. With
nearly all forceps, the spring is too strong; it should be only suffi-
cient to separate the blades when the pressure of the fingers is
relaxed. If the dealers will not supply forceps with the proper
spring, the desired change may be effected with a file or grindstone.
The ‘Coxeter’? style of coarse forceps is to be preferred. Those
represented in Fig. 18, have the blades excavated so as to be lighter
than those formerly made. ;

§ 146. Nippers— Fig. 10, 11.—These are the ‘diagonal side
cutting nippers or pliers” of the. dealers in hardware. The obli-
quity of the blades to the handles gives them great advantages over
either the ‘‘ side cutting’’ pliers, or the ‘‘ cross cutting,’ which are
shown in Fig. 10, left figure. Seven sizes are made, ranging from
10-20 em. (4-8 in.) in length. Those of 10 and 15 em. are best
adapted to anatomical work upon small animals. The larger of
these will cut any of the bones of cats less than two years old, but
the larger bones of older individuals may require the saw. For
some purposes the points should be quite sharp, and may be made
so with a file or upon a grindstone.

A. “Pointed nippers with oblique jaws” are mentioned by Newton (B, 22, 174), but
they do not appear to be in general use by anatomists. The nippers have been used in

anatomical work, especially for the removal of the brain, by the senior author since i871,
and are mentioned in his paper, 77, 158.

68 ANATOMICAL TECHNOLOGY.

B. The German instruments answer very well for most purposes, and are much less
expensive than the others. They are imported by Messrs. H. Boker & Co., of New York,
and may be had of A. J. Wilkinson in Boston, and of Messrs. Treman, King & Co. in
Ithaca, and of larger dealers generally. The ‘“ Stubs’s” nippers are more finely tempered,
and better finished. The smallest size (Fig. 10) are sold by Messrs. Codman & Shurtleff
for $1. The “bone forceps” of the surgical price lists are still more expensive.

C. The ‘‘ cross cutting” ral are employed chiefly for cutting wire and for other
mechanical purposes.

§ 147. Oiler.—A sk substitute for the ordinary metal oiler
may be made by suspending a dropping-tube in the mouth of
a vial of oil. One may then graduate the amount more exactly,
and apply it more accurately ; see Appendix.

§ 148. Parchment Numbers.—Sheets of numbers of any size
may be had at a reasonable rate from ‘‘Collins’ Printing House,”
Philadelphia. If they are to be used with alcoholic specimens, that
fact should be mentioned so that proper drying ink may be em-
ployed. The numbers may be pasted upon dry specimens, or
placed in the alcohol with wet ones, or attached to muscles during
dissection by means of the small ‘‘ ribbon pins.”

§ 149. Parchment for Labels.— Numbers and memoranda to be
attached to alcoholic specimens should be written upon parchment
with a saturated solution of India ink in either glacial acetic acid,
or acetic acid No. 8. The writing should be allowed to dry before
exposure to the alcohol. Parchment is written upon more easily if
the surface is first rubbed with a rubber eraser.

§ 150. Rubber Gloves.—These are an efficient protection against
contact with poisonous or malodorous substances. Of course, fine
dissection cannot be done in gloves, but it is sometimes desirable
to protect the hands, especially in the manipulation of the intestines,
and while macerating bones. Like other rubber articles, the gloves
should be wiped dry after using, and laid in a cool, dark place.

§ 151. Rubber Tubing.—For the blow pipe, and for canule,
the lumen should be 3 mm. (1-8th inch); the size next most use-
ful in the laboratory is 6 mm.

§ 152. Saw—Fig. 21.—This should have a thin blade, and the
teeth should be but slightly ‘‘set.”
It is used chiefly for bisecting the
head for the removal of the brain,
and should not be employed for
mechanical purposes. fa ae

§ 153. Scales.—Very few cats Fie. 21.—Back Saw; x.14.
weigh as much as 5 kilos., and heavier ones can be weighed entire

v

WEIGHING PAN. 69

upon ordinary scales. For most anatomical purposes, therefore, the
scales need not be arranged for more than 4-5 kilos., or about 10
Ibs. avoir. Weights of less than 1 gram should be determined by
the smaller or ‘‘ prescription”’ scales.

Of the larger scales there are two styles, the ‘‘ open” and the “box.” An example of
the former is the ‘‘ Druggist’s trip scales,” figured by J. & H. Berge, A, 63; of the latter,
is the ‘‘ Ebony box scale,” figured by Whitall, Tatum & Co., A, 74. With a capacity of
10 Ibs., the former costs $7, and the latter $14. In selecting scales, it would be well to
obtain the advice of some chemist or physicist.

§ 154. Weighing Pan.—The scale pans accompanying the scales
above mentioned are about 20 cm. in diameter, and will contain any
separate organ of the cat, or the head or limbs. For weighing an
adult cat entire, a larger pan is needed. For this purpose, one of
the ordinary trays, 30x 40 cm. may be used, but it is better to pro-
vide a special pan. It should be oval or oblong, about 25 x 35 cm.,
made of stout tin, and with a rim about 3 cm. high. Its weight
may be diminished by punching out disks not more than 1 cm. in
diameter, until it exactly balances some weight, as 500 grams,
or a piece of lead, which, of course, must be used always with the
pan. Ifthe cat to be weighed is stiff, it may sometimes be made to
rest upon the ordinary scale pan without touching anything ; other-
wise this special pan should be used, the arms and legs and tail
being kept within it.

§ 155. Scalpels—Figs. 22, 23, 24.—These are single edged, and
thin bladed knives, with ebony or ivory handles. The medium size

Fie. 22.

COOMANASHURTLEFE
sosTON

Fie. 28. Fie. 24.

pore prema

Fie. 22—LARGE SCALPEL, for sections of brain, ete.; § 155; x.5. Fic. 23.—Mzp1um-
SIZED SCALPEL, for ordinary dissecting; x .5; § 155. Fie. 24.—CHARRIERE
ScALPEL, for finer dissecting; x .5; § 155.

OODMANESHURTLEFF <
sosToN

(Fig. 23) answers for most purposes, and will last a long time if care-
fully used. The ‘‘Charriere’”’ is employed for finer—but not the
finest—dissecting, and the large scalpel should be kept perfectly
smooth and keen for making macroscopic sections of the brain,
heart, ete.

70 ANATOMICAL TECHNOLOGY.

§ 156. Scissors—Figures 12, 25.—All dissecting scissors should
be curved. The curvature gives three advantages: better adap-
tation to the surfaces of
animals and their parts,
which are rarely plane;
the power to change the
Y direction of the cut with-

Fig. 25.—CoARSE ScissoRS CURVED FLATWISE; out corresponding move-
ae aay ment of the hand or of

the subject ; the effect of the cutting is more easily observed. For
most purposes, the blades should be curved /flatwise, as in Fig. 25,
but those curved edgewise, as in Fig. 12, are sometimes very con-
venient. All coarse scissors should have lock joints, so that the
blades may be separated for cleaning and sharpening. Fine scissors
should have sharp and well matched points. The medium coarse
scissors are well adapted to work upon the brain and heart, and

other organs for which the coarse scissors are too large, and the fine
ones unnecessarily delicate.

§ 157. The bone scissors are simply a strong, blunt-pointed pair
of coarse scissors, with which the cartilages, ribs, and other hard
or tough parts may be cut, so as to save the edges of the proper
dissecting scissors. A straight pair will answer the purpose quite
well, and usually cost somewhat less.

§ 158. The hair may be removed with a pair of common cheap
scissors; but it is better, especially in a large laboratory, to provide

a special pair of coarse scissors, curved flatwise, and with the points
quite blunt.

§ 159. The enterotome supplied in post-mortem cases is a pair
of long scissors, one blade of which is enlarged and rounded, and
projects beyond the other so as to precede it in opening an intestine.
Similar instruments might be made for the cat, but the same end
may be accomplished by guarding one of the blades of a pair of
coarse scissors, especially such as are curved edgewise. Cleland
suggests (A, 155) sticking a bit of costicartilage upon one blade,
but a small rubber stopper will serve the purpose.

§ 160. Sponges.—Sponges may be conveniently classed as car-
riage, bathing, anatomical and surgical. The last are fine grained,
and specially prepared, so as to be somewhat expensive. A few
such, of conical shape, are desirable, especially for experimentation.
For ordinary anatomical purposes, sponges should be small enough

ee SSS eee
CODMAN & SHURTLEFF,
BOSTON.

THE SYRINGOTOME. 71

to be easily grasped, and should be freed from sand and grit before
using. The larger and coarser kinds are useful in various ways.

All sponges should be washed after using, and boiled occasion-
ally for a few moments. Itis said that they may be freshened by
soaking in brine to which a little iodine has been added.

§ 161. Syringotome—Fig. 15.—This is sometimes called ‘‘can-
aliculus knife.”? It is a small, concave, blunt pointed bistoury,
which is very convenient for delicate work upon the brain and heart,
and for following and slitting up narrow canals.

The syringotome was found very serviceable by the senior author in tracing out the
tortuous canals upon the heads of sharks and skates at the Museum of Comparative
Zoology in 1866-7. At his suggestion it was included in the set of dissecting instruments
supplied to the students of “The Anderson School of Natural History at Penikese Island ”
in 1878. Excepting with the brain, however, most of the uses of the syringotome may be
subserved by the less expensive tracer.

§ 162. Tags.—Two sizes of tags are needed: the smaller are for
numbers or brief memoranda sufficient to identify the specimen ;
they are used by stationers and dry goods dealers. The larger are
the smallest size of ‘‘ Dennison’s Shipping tag,” and are 3.5 cm. wide
by 7.2 long; they should be provided with strings, and the eyelet
should be guarded by a metal ring.

§ 163. Tenaculum—See Codman & Shurtleff, A, 42, Fig. 8.—
This is seldom needed in felitomy.

§ 164. Tools, Carpenter’s.—A laboratory should contain the
ordinary tools, as saw, hammer, screw drivers, awls, bits and stock,
rat tail and three cornered files, screw hooks and eyes, etc.

§ 165. Towels.—Excepting the roller towels, these should be
short. The finer crash is more expensive, but wears longer than
the cheaper stuffs, and there is less lint; it may be had in rolls,
which may be cut into the desired lengths.

§ 166. Tracer—Fig. 17.—This is prepared from a piece of hex-
agonal or octagonal steel rod, about 15 cm. long, and 4 mm. in
diameter. The middle third is left as a handle; one of the terminal
thirds tapers to a blunt point, and serves as a probe for some
purposes; the other end tapers in like manner, and is bent at the
tip so as to form about the fourth of the periphery of a circle 1 cm.
in diameter ; the concavity i is then sharpened.

The value of the tracer in isolating vessels and nerves can hardly
be overestimated. A dull tracer may be used also in lifting vessels
and nerves that have been isolated already, as in experiments.

72 ANATOMICAL TECHNOLOGY.

A. A tracer may be made by any one from a piece of steel rod, or from a dental ‘‘ exca-
vator,” but the saving so effected is hardly worth the trouble. The instrument is made by
Codman & Shurtleff, and perhaps by others.

B. The tracer is apparently similar to the “seeker” of the English anatomists, and the
“* finder” of the Germans. The instrument was introduced into the laboratory of Cornell
University with a microscope presented by the late Hon. John Stanton Gould. The con-
version of the opposite end into a tapering probe was suggested by Mr. Willis N. Rudd, a
student, and the sharpening of the concavity was first proposed by the junior author,

§ 167. Trays—Fig. 78.—These are usually made of stout tin, but
copper is more durable. If wood is used, it should be thoroughly
oiled. A wire loop should be soldered at the middle of each end,
and on each side at about one-sixth of the distance from each end.

Four sizes of trays are convenient in the dissection of cats:
15 x20, 20x30, 30x40, and 40x60cm. The depth of the two
smaller sizes should be about 1 cm., and that of the two larger .
about 2cm. The largest size should be stiffened by diagonals upon
the bottom.

§ 168. Tripod Magnifier—Fig. 26.—This is a simple magnifier
with a large field, and mounted upon a tripod which may be placed

C

i i

Fie, 26.—TRrIPOD MAGNIFIER; x 1; § 168. Fic. 27.—WeEtTTINn@ BorTLeE; § 170.

in liquid. While examining delicate objects out of liquid, it is
safer to turn the legs toward the eye, or remove them altogether.
The object should be held so as to receive the best light.

§ 169. Tunnels.—Several sizes are desirable, of both glass and
tin. The latter should have the slender part fluted. When the
larger part of a tin tunnel, or either part of a glass one, is set into a
bottle or jar, a thick string should be interposed between it and the
mouth of the vessel to permit the escape of air as the liquid enters.

WASTE PAPERS, 13

§ 170, Wetting Bottle—lig. 27.—The bottle is about 16 x5 cm.,
so as not to be easily overturned. The mouth is closed by a cork
through which are passed two slender glass tubes. One, the air-
tube, is straight, and reaches nearly to the bottom of the bottle ; the
other, the spowi, extends but little below the cork, and is curved so
as to permit the ready application of the contents.

§ 171. Wetting Mixture.—The cheaper commercial glycerin is
to be mixed with water in the proportion of 15 per cent. by measure,
or 12 per cent. by weight, and about 25 drops of clove oil is to be
added to each liter of the mixture.

§ 172. Waste Papers.—These are pieces of paper of several
sizes, corresponding respectively to the slips, the sheets, and the
trays,

The quality of paper is not material, so long as it is firm enough
to hold together when slightly wet. The ‘‘roll Manilla’’ paper of
medium thickness is strong and cheap, but the ordinary slips and
sheets which have been used by writing on one or both sides may
be kept for this purpose.

With fine dissections, or when only connective tissue or small
muscles are to be removed, the waste slip may be placed in a corner
of the tray.

With coarser work, and when skin, fat, and the larger muscles
or viscera are to be removed, use the waste sheet.

When the cat is to be transected or eviscerated, or when some
larger animal is under dissection, have at hand extra trays contain-
ing the corresponding waste papers.

The waste should be disposed of as soon as possible, but in case
the opportunity for re-examination is desired, the tray containing it
may be set aside, and the paper will obviate the objectionable
adhesion of the waste to the tray itself which might Otherwise
occur.

CARE OF INSTRUMENTS.

§ 173. In general, all instruments should be washed, thoroughly
dried, and slightly oiled as soon as possible after using.

The washing may be done with a cloth or sponge, but the nail
brush should be used for the joints of nippers, and the teeth of the
saw. The wiping may be done with a towel, and then with a bit
of clota or chamois slightly oiled.

All joints should be kept well oiled.

%4 ANATOMICAL TECHNOLOGY.

The oiling should be especially thorough when instruments are
to be packed away or disused for some time, and particularly at
the sea shore. .

Scalpels and other instruments with wooden or ivory handles
should not be allowed to soak in water, lest the rivets become loose
after drying. Wooden handles should be occasionally oiled.

§ 174. Blow Pipe.—Usually this needs only to be wiped, first
with a moist, and then with a dry cloth. After using, be sure that
the lumen is free; if clogged, open it with the fine knitting needle,
or a wire.

§ 175. Forceps.—Clean the serrated parts with the nail brush,
draw a cloth or towel between the blades, and then wipe.

§ 176. Nippers.—Clean the joint and blades well with the nail
brush, wipe dry, and oil the joint.

§ 177. Saw.—Use the nail brush, moving it from the back to-
ward the teeth. Wipe, carrying the towel in the same direction.
Then wipe dry, and oil.

§ 178. Scalpels and Cutting Instruments Generally.—These
instruments, and especially such as have keen edges and delicate
points, should be protected from contact with each other and with
other objects. If not kept in a case, they may be laid in a small
tray, like the cover of a note box lined with chamois or velveteen.
When several are to be carried at once, each handle should be held
between two fingers so that the blades may not touch.

In wiping a scalpel, hold it firmly in the left hand, and let the
cloth cover the right thumb and index, as in wiping a table knife ;
do not let the cloth come upon the edge. The scalpel should be
wiped four times: first with a moist cloth to remove all blood and
fragments; then with a dry cloth; then with an oiled cloth or
chamois, and finally with a clean dry cloth or chamois. The fingers
should not touch the blade after the final wiping.

$ 179. Scissors.—If the blades are lock jointed, they should be
separated. The blades are to be treated like the scalpels. Clean
the joint thoroughly, and keep it oiled.

§ 180. Trays.—If waste papers are used, the trays will usually
require only rinsing, after which they should be set up on edge to
dry. Where many trays are used, there should be a suitable rack
for them.

§ 181. Instrument Cases.—The experienced anatomist rarely
uses the ‘‘case’’ in which, probably, his first instruments were

PACKING INSTRUMENTS FOR TRANSPORTATION. 5

purchased. The ordinary case never has room for all the neces-
sary instruments, and is a less convenient receptacle for them
while in use than a shallow tray like the cover of a note box;
see § 110.

If the student is unable to resist the temptation to possess a
regular dissecting case, he is advised to obtain one of the more
costly, as likely to contain better instruments. The case commonly
selected by the special students at Cornell University is sold by
Messrs. Codman & Shurtleff at $9, and contains the following
instruments: three assorted scalpels, coarse and fine forceps, coarse
and fine curved scissors; arthrotome, and blow pipe. Similar cases
may probably be had elsewhere. The additional instruments must
be purchased separately.

§ 182. Packing Instruments for Transportation.—All scalpels
and delicate pointed instruments generally should be packed as
follows: thrust the point into a bit of cork, then wrap well in a
piece of thin paper, such as is supplied in packages under the name
of ‘‘ star mills,’ “diamond,” ete. The paper should project well
beyond the blade, and be twisted or bent over so as to keep the
cork in place. Thus wrapped, the most delicate instruments may
be sent by mail in pasteboard or light wooden boxes, or otherwise
transported. Since no written communication is permitted upon
such a package without payment of letter rates, the consignee
should be notified at the same time. Whether for mailing or any
other kind of transportation, the heavier instruments, or such as —
need no special protection, should be packed separately from the
more delicate. Small cigar boxes answer a good purpose, but the
most suitable boxes for instruments are made by the Swift Manu-
facturing Co. of New York, and others; they are long and narrow,
and provided with lids.

POLISHING INSTRUMENTS.

§ 183. A. Instruments that have become tarnished may be re-
polished by rubbing with a piece of chamois or cloth on which has
been put oil and rouge. Perhaps the best way to apply the polish-
ing material is to wrap the cloth around the end of the index for
small instruments, or roll the cloth or chamois into a bundle for
large instruments. In both cases the surface to be polished is
rubbed as in scouring household knives, taking care to avoid con-
tact with the edge of the instrument.

76 ANATOMICAL TECHNOLOGY.

B. Rust should be removed with a dull knife and then the
polishing may be done as above. When an instrument is badly
tarnished, the polishing with rouge is a tedious process. In that
case, fine emery may be used to remove the tarnish, and then rouge
for the final polish. The emery should be applied as directed for

rouge.

C. If one has access to a polishing wheel the process is shortened greatly. The
same materials are used as in polishing by hand and in the same order.

D. Emery of exceeding fineness may be easily prepared as follows: Fill a high narrow
vessel like a preserving jar, nearly full of water, and put into it about 200 grammes of
ordinary flour of emery. Agitate thoroughly, and after the vessel has stood half a minute
pour off the liquid into another dish. Add more water to the first vessel and agitate again,
and pour off the liquid as before. The larger particles sink first, and hence the emery in
the water poured off is much finer than that left. Allow the emery to settle from the first
and second washings and pour off the water and dry the emery. Several grades may be
obtained in this simple way.

E. Instruments may be very nicely polished by using, in place of rouge, the fine
whitish ashes that may be found in the upper parts of stoves in which anthracite coal is
burned.

F. If rouge is added to the oiled leather used for wiping the instruments after they
are washed (§ 178), the polish may be retained indefinitely.

SHARPENING INSTRUMENTS.

§ 184. Honing.—For honing, it is desirable to have two oil
stones, one very fine for finishing, and one somewhat coarser for

Turning knife,
ak ee
Honing. | Stropping.
Oil stone.

Fie 28.—HONING AND STROPPING Knives. The upper figure shows how the knife is
to be turned upon its back in reversing the movement. The left figure shows the
edgeward movement of the blade in honing; the right, the backward movement in
stropping. §§ 184, 185.

HONING. 7%

commencing the sharpening, and for sharpening the coarser instru-
ments.

A. Place several drops of fine olive or sewing-machine oil on the
stone and, with a cloth devoted to the purpose, rub the surface to
remove all dirt and expose the cutting particles of the stone. After
the stone is well wiped, put two or three more drops of oil upon it,
and spread it around with a scalpel blade.

B. Look at the edge of the instrument to be sharpened with the
tripod magnifier, holding the edge of the blade up and between the
eye and the light. This is to see if there are any nicks in the edge.
If there are nicks, they should be removed by rubbing the edge on
the fine stone. After making two or three sweeps across the stone,
look at the edge again to see if all the nicks are removed. If they
are not, continue to grind the edge on the stone till they are. If the
nicks are slight the edge need be ground off only in their immediate
vicinity. If they are deep, however, the entire edge should be re-
moved or it will become wavy.

When the edge is smooth and free from nicks it should be
honed ; if quite dull, first on the coarse and then on the fine
stone.

C. In case the instrument is a scalpel, (1) grasp the handle in
such a way that the index and medius shall oppose the pollex, and
the end of the handle shall touch the palm. (2) Place the blade
flat on the stone as shown in Fig. 28, and then lift the back very
slightly. (3) Move the knife with a curving sweep toward the left,
as shown by the arrow, so that the point of the blade shall be at
the lower left corner at the end of the sweep. (4) Then turn the
blade over, always turning the edge away from the stone. Do this
by rolling the handle in the fingers. (5) After the knife is turned, it
should be moved across the stone from left to right exactly as
described for the motion from right to left. The handle, of course,
points in the opposite direction.

In this method of honing, which is that employed by the best cutlers, the edge precedes
the back; the blade is so placed on the stone that it follows the handle, and the

sharpening is from heel to point. If the blade were pushed across the stone instead of
being drawn as above, the sharpening would be from point to heel.

D. In the beginning of the honing, one may press quite firmly
and draw the same side of the blade over the stone three or four
times without turning it; but when the edge becomes thin, the
blade should be turned at every sweep.

78 ANATOMICAL TECHNOLOGY.

E. In case the edge should turn over, producing the so-called
wire edge, it must be removed by drawing the edge along some fine-
grained substance like horn or ebony. One should be careful not
to get any of the detached wire edge on the stone, as it would be
liable to produce nicks in the edge of the knife.

F. (1) Use the coarse stone until the knife will cut a thin shaving
from the convex surface of smooth writing paper. (2) Wrap the
paper around a lead pencil, remove the pencil and rest the blade
flat upon the paper. Press down slightly, and push the blade,
edge forward, along the top of the curve. If the knife is sharp, it
will cut a thin shaving from the paper. (8) Another very excellent
way to judge of moderate sharpness is to rest the tang of the blade
on the end of the medius, and to feel of the edge by moving the ball
of the index along it in such a way that if a cut were made it
would be a mere shaving from the cuticle like that from the paper.
If the knife is sharp, it will fake hold, as it is called, that is, one
can feel that it is cutting. The ball of the index is very sensitive,
and one can judge quite correctly of the smoothness and sharpness
of the edge. Those who object to trying the edge on the skin
can employ a bit of smooth grained cork.

G. (1) When the edge is sufficiently sharp throughout its entire
extent to cut a shaving from the cylindrical paper, or to take hold
of the finger or the edge of the cork, the fine stone may be used.

(2) In using the fine stone the blade should be turned at every
sweep. Use the fine stone until the knife will cut a hair near its
base or near the point where it is held.

(3) It often happens that some parts of an edge are sharp and
others not. In sucha case the dull parts alone can be applied to
the stone by using the edge of the stone.

When the scalpel will cut a hair close to a fixed point, it is

sufficiently sharp for ordinary dissecting.

§ 185. Stropping.—A good razor strop is santas; as, €. g.,
“ mersons’.”’

The strop is to give the final keenness and smoothness to the
edge of a cutting instrument. It is a waste of time to employ it
before the degree of sharpness indicated for the fine stone is
attained, as the strop sharpens very slowly. .

- A. (1) Grasp the knife exactly as for honing. (2) The blade is
carried across the strop with a long curving sweep just as de-
scribed for honing except that the back of the blade precedes the

KILLING ANIMALS FOR DISSECTION. 79

edge. (Fig. 28) (8) The blade should be turned at the end of
every sweep across the strop, thus drawing it from right to left as
often as it is drawn from left to right.

B. (1) Use first the red and then the black side of the strop.
(2) Press only moderately. The nearer a perfect edge is attained
the more lightly should one press.

(3) Continue the stropping on the red side until the knife will
cut a hair of the head 1 cm. from the point where it is grasped by
the fingers ; then employ the black side.

(4) Continue to use this side until the knife will cut a hair from
the head 2-3 cm. from the point where it is held, or, what is a better
test, until it will cut the fine hairs on the dorsum of the hand and
wrist half a centimeter from their base when the knife is moved
distad—toward the ends of the fingers. If the knife has a perfect
edge it will cut these fine hairs so easily that one can hardly tell by
the feeling when a hair is divided.

§ 186. Scissors.—These are much more difficult to sharpen than
scalpels, and the fine ones should be sent to the makers unless
one is very skillful. Place the blade so that the oblique face
formed by grinding shall rest flat on the stone. Draw the blade,
edge foremost, across the stone with a curving sweep as for scalpels
(§ 184, C [8] ). Test for sharpness with the finger or by attempting
to cut moistened tissue paper (§ 184, F [8] ).

§ 187. Tracer, Syringotome and Concave Edges Generaily.—
In sharpening instruments of this Kind one should use the edge of
the stone instead of its face. The edge of the stone should be some-
what rounded. In sharpening, draw the blade along the stone so
that the edge precedes the back as for scalpels (§ 184, C [8] ). Test
the sharpness with the finger (§ 184, F [3] ).

_ § 188. The care and sharpening of instruments are considered by Mojsisovics, A, 13 ;
Holtzapffel, A, III, 1026-1156; Hyrtl, A, 23-27; Straus-Durckheim, B, 1, 158-160.

KILLING ANIMALS FOR DISSECTION.

§ 189. There is usually no difficulty in taking a cat when it is
wanted. Such as will not come when called may be secured by
means of a strong net, or by using a bag attached like a net toa
hoop and pole.

The bag referred to is of strong coarse material, and commonly
used for oats. In such a bag the cat may be left for several hours ;

80 ANATOMICAL TECHNOLOGY.

but the closer-woven bags which are used for flour do not admit
- sufficient air.

§ 160. Methods of Killing —(Bernard, A, 149-182).—Two things
are to be considered in killing animals for dissection :—

(1.) The death should be as nearly painless as possible.

(2.) None of the organs or tissues to be examined should be
injured by the method employed.

§ 191. Drowning fulfils the above requirements fairly well.
Judging from the experience of human beings, death by drowning
is attended with very brief physical discomfort.

Place the cat in a wire cage, or loose meshed bag, and immerse
it completely in water for four or five minutes. Usually a cat can-
not be resuscitated after it has been completely immersed for ninety
seconds; after four or five minutes, spontaneous resuscitation is
altogether improbable.

§ 192. Chloroforming is preferable to drowning, since no liquid
is drawn into the lungs, and the hair is not filled with water. The
death, too, with cats, seems to be quietly going to sleep. There is
usually no struggling, showing that the period of intoxication by
the chloroform is very short.

Place the cat in the anesthetic box (see Fig. 29). This is easily
accomplished if the cat is in a bag by placing the mouth of the bag in
the box, whereupon the cat will usually walk in of its own accord.
After the cat is in the box and the door closed and fastened, remove
the cork from the hole in the edge and pour 5-10 ce. of chloroform
upon the furled curtain. Then unfurl the curtain by means of the
string ; this will expose a greater surface from which the chloroform
can evaporate. Usually the cat will be asleep in three minutes, and
dead in twenty minutes. Do not remove it from the box till all
signs of respiration have ceased.

If ether is used, 15-20 cc. is required for a cat.

A. If one does not possess the anesthetic box, cats may be chloroformed as follows:
Place a newspaper on the floor, and invert over it a large wash-bowl or a small tight box
or pail. Put the cat under the receptacle, and pour 10 cc. of chloroform on a sponge or |
a bit of cotton, and put it under the receptacle with the cat. The box, or whatever is
used, must be held down, ora weight must be placed upon it, while the animal is coming
under the influence of the anesthetic,

B. Dogs moan while becoming anesthetized, but presumably they and all other ani-
mals may be killed painlessly with chloroform or ether. The amount required to kill an
animal varies with its size, and with the size and closeness of the box.

§ 193. Killing Fleas.—If the cat has fleas, as is usually the case,

PRECAUTIONS FOR CLEANLINESS, ETC. 81

open the box after fifteen minutes, and throw over it 20 cc. of ben-
zine. Reclose the door of the box and leave it for ten or fifteen
minutes longer. Fleas revive from the chloroform used in killing
the cat, but they do not revive if benzine is used.

Do not use the benzine until the cat is completely anesthetized,
for it causes great discomfort.

§ 194. The Anesthetic Box—Fig. 29.—This is a close box, the
base, frame and door being of wood, and the rest of ‘‘ double-thick”’

Fia. 29.—THE ANASTHETIC-BOX; x .1.

glass. The dimensions are given in the figure. The base and frame
should be grooved for the reception of the glass, and the whole
should be put together with screws to permit the renewal of the
glass in case of breakage.

Along one side, near the top, runs a thick brass wire, on which
slides a curtain, moved by a string. Just above the curtain, when
furled, is a hole, which is closed by a cork secured from loss by a
string. The leather handle is convenient in lifting and moving the
box.

The cost of the cat-box, including the glass, is about $1.50.

Almost any close vessel or box will answer for the administra-
tion of a fatal dose of chloroform, but for experimental purposes
the progress of anesthesia must be observed.

PRECAUTIONS FOR CLEANLINESS, COMFORT AND
HEALTH.

§ 195. Waste Papers.—These have been referred to in § 172,
and are mentioned here again because of the tendency of beginners
to neglect a very essential element of neatness in anatomical work.

§ 196. Waste Pail.—This should be of galvanized iron, copper

6

82 ANATOMICAL TECHNOLOGY.

or zinc, never of wood or tin ware. The cover should be of the
same material, and fit closely. The pail should be emptied at
night, rinsed, and a few cc. of permanganate of potash solution
poured into it. Once a week it should be thoroughly scoured and

~ dried.

§ 196. Waste Pit.—The single student may readily dispose of
the refuse of his work, but some special provision must be made
for a laboratory.

In cities, communication may sometimes be had with the sewer.
The opening into the sewer should have at least two lids, closely
fitting, and should be within a closet or cupboard provided with a
special flue so that the sewer gas may not be drawn into the labo-
ratory.

In smaller towns, and at many universities, the readiest mode
of disposal of refuse is to have a pit dug in dry soil at a convenient
distance. The mouth of the pit should be kept from falling in by a
cask or box, and should be closely covered. The earth removed
in digging the pit should be kept at hand under cover, and some of
it sprinkled over the offal at night. When filled within half a meter
of the surface, the pit should be filled up compactly with earth.

§ 197. Sink.—This should be of iron, galvanized iron, zine or
copper, or lined with one of these materials. It should be slightly
inclined, the outlet should be at the lower end, and guarded with a
movable grating. The escape-pipe should be of ample size, and
trapped at some point which can be reached.

Excepting just over the escape, the sink should be covered
by one or more wooden lids on hinges which may be raised from
the front and rested against the wall behind the sink. These
lids should be of hard wood, and well oiled or painted. In
each lid should be cut an oval or elliptical hole for a basin.
The longer diameter of the hole should correspond with that of
the sink, so that the basin may be emptied without lifting it from
its place.

If there is no general water supply, a water cask or lead lined
box may be placed above the sink. In any case, the faucets should
be nearly on a level with the face of one standing at the sink, and
the water should be conducted therefrom through flexible rubber
tubes ending a little above the basin. The tube must be firmly
secured to the faucet, and must not be sharply bent if the pressure
of water is considerable.

DEODORIZERS. 83

Hair, plaster of Paris, sand, and fine particles generally must
not be thrown in the sink.

The sink should be thoroughly emptied and washed at night.
A convenient instrument for scraping out the sink, or cleaning a
table or tray, is a piece of heavy rubber moulding, provided with a
handle.

§ 198. Deodorizers.—Most of the unpleasant smells which
would otherwise attend work in practical anatomy may be avoided
by preserving the material in alcohol, by removing the intestines
within twenty-four hours after death, and by the observance of
other due precautions for cleanliness. But maceration is necessarily
offensive, and sometimes valuable specimens are more or less de-
composed before their reception ; it is therefore necessary in some
cases to employ deodorizers.

Animal Charcoal.—This effective deodorizer may be sprinkled
over the surface of offensive specimens, and is especially service-
able when such have to be transported. Its use in the improve-
ment of old alcohol is described in Ch. III.

Alcohol.—If the specimen is of moderate size, and is to be pre-
served as a whole or in great part, the putrefaction may be checked
by immersion in strong alcohol, from 75 to 95 per cent. The alcohol
may be poured over the specimen, or the latter may be immersed
in it, or covered by cloths saturated with it. In either case, the
alcohol will become offensive, and must be deodorized by filtration
before mixing with other alcohol or use upon other specimens. The
stronger the alcohol, the more decided is its action, but its clearness
is unessential.

Potassium Permanganas.—This is an excellent deodorizer. A
saturated solution should be kept at hand, and a few cc. poured
into the waste pail at night, and into any other malodorous jar or
vessel. It stains the skin temporarily.

Sulphate of Iron—Copperas.—This cheap deodorizer may be
used in place of the more efficacious but more expensive perman-
ganate of potash. The coarsely powdered crystals, or a saturated
solution, may be placed in the sink, pail, or pit.

A solution of Chloride of Lead is recommended in The Medical Record, August 20, 1881,
p. 222.

§ 199. Discharges from the Cat.—The following precautions
are always desirable, and should never be neglected in demonstra-
tions or experiments upon cats before a class :—

84 ANATOMICAL TECHNOLOGY.

When the cat is dead, or, in experiment, quite asleep, place it
upon a tray. Roll some common cotton between the fingers into a
somewhat firm conical plug or suppository about 5 x1 cm.

Dorsiduct the tail of the cat so as to expose the anus and open
it slightly. With the large forceps grasp the plug obliquely near
the tip and force it into the rectum. Then push it completely
beyond the constricted orifice with the forceps or a smooth, rounded
stick. Ifthe cat has been affected by diarrhea, it may be necessary
to insert a second plug.

Let the buttocks of the cat project slightly beyond the edge of
the tray, over the sink or some other receptacle ; then press firmly
and steadily upon the abdomen just cephalad of the pubes. If the
cat is a female, the urine will usually flow out readily; if it does
not appear, as is often the case with males, it is not likely to be
forced out during the subsequent operations.

The urine of cats has a very offensive odor, and should not be
allowed to flow into the tray, or to reach the hair of the animal.

Remove any escaped urine or feces with a bit of cotton, followed
by washing if necessary.

If the left hypochondrium is prominent, or if there is other
evidence that the stomach is distended with food, let the mouth pro-
ject beyond the tray over a receptacle, and compress the whole
abdomen. If any matters escape from the stomach, the mouth
should be washed afterward with a stream of water.

§ 200. Mialodorous Parts.—On account of their contents, the
stomach and intestine become offensive very soon after death, espe-
cially if exposed to the air.

In some cases it may not be necessary to open the abdomen
during the dissection of a fresh specimen ; decomposition will then
proceed less rapidly, and the effects will be less obvious.

If the abdomen is opened, these hollow viscera should be either
removed soon, or so treated as to lessen or prevent the production
of offensive odors. The large intestine especially may usually be
examined during the first or second day, so as to be removed.

When any part of the alimentary canal is divided, the site of
the intended incision should be freed from its contents for at least
2cm.; then two ligatures should be applied at least 1 cm. apart,
and the cut made between them ; see Fig. 41.

When it is undesirable to remove the intestine, most of the
offensiveness may be avoided by expelling the contents. The con-

DISSECTION WOUNDS. 85

tents of the large intestine are readily forced out by manipulation,
the cotton plug of course having been removed. Those of the small
intestine may be made to flow out with a stream of water injected
into it near the stomach by means of a syringe, or from a faucet.

The water should be pressed out of the intestine, and alcohol
then thrown into it. The alcohol may be retained if the plug is
returned to the anus; ora ligature may be placed about the rectum.

§ 201. Dissection Wounds.—Slight dissection wounds have oc-
casionally been received in the anatomical laboratory of Cornell
University, but the results have been nowise different from similar
cuts inflicted under ordinary circumstances.

So far as our experience goes, it is probable that no danger need
be apprehended from a wound received during the dissection of
any well preserved alcoholic specimen, or of any healthy cat, .
whether fresh or otherwise. .

In proportion to the number of human bodies annually dissected or examined in
necropsies, serious dissection wounds are very few. Indeed, the aciual number of such
cases is so small that statistics are wanting to enable us to determine with accuracy the
conditions under which the consequences are likely to be injurious. A few writers
believe these results to be due to “the absorption and irritation of a putrescent fluid; but
this explanation will hardly account for the frequency of the disease after contact with
recent bodies before putrefaction has set in, and especially of persons who have died of
acute disease, such as puerperal fever, peritonitis, etc., and for the affection of several per-
sons at the same time, from the same body and with the same symptoms.”

In view of the insufficiency of our knowledge, and of the fact that dissection wounds
are most apt to occur with beginners, one of the advantages of the cat as a subject of pre-
liminary anatomical work is, that the subject may be obtained healthy and fresh, and be
preserved in alcohol at slight expense.

§ 202. Precautions.—Dissection wounds should be avoided by
care in the use of cutting and pointed instruments, and by guard-
ing against contact with the sharp points and edges of bones which
have been broken or cut.

Before commencing work upon a suspected animal, or upon
decomposing flesh, or upon macerated bones, the hands may be
anointed with some kind of fat, as cosmoline, vaseline, olive oil or
‘cold cream.”’

If the skin is already broken, rubber gloves may be worn, as in
macerating or in handling offensive viscera, etc., where no delicacy
of manipulation is required. In ordinary dissection upon a suspected
subject, the cuts or abrasions may be cauterized with strong carbolic
or nitric acid, or covered by several thicknesses of adhesive plaster.

86 ANATOMICAL TECHNOLOGY.

If the hands can be kept dry, the common court plaster or isin-
glass plaster will suffice; but if they are to be wet, it is safer to use
the diachylon or lead-plaster, which does not easily wash off, but
must be warmed before application or removal.

In cauterizing, use a slender, pointed stick ; dip it first into the
acid, and then into the open place of the skin.

§ 203. Treatment.—* Local applications, if used at all, must be
employed immediately, decisively, and effectually. Should a per-
son be in bad health at the time of receiving a prick or wound
during dissection, no matter what condition the subject may be in,
it behoves him to pay immediate attention to the injury, and anti-
cipate any further consequences.”’

“Should the wound be received while engaged on a recent sub-
. ject, and one which had died from acute disease, much more
caution and attention are required, even if he be in the best of
health. The part should be well cleansed, and a temporary liga-
ture applied immediately above (centrad of) the wound; then the
bleeding, if any, should be encouraged to flow freely ; where there
is no bleeding, suction must be employed; [this may be by the
mouth if the skin and mucous membrane are intact, otherwise by
means of a tube, or, better, a cupping glass the exhaustion of which
is produced by means of a rubber bulb].’’ Then cauterize as
directed above.

The foregoing directions for immediate treatment are taken from
Holmes (T.) A, 621, and Clarke, A, 54.

Whenever ill effects are anticipated, proper medical advice
should be sought without delay.

CHAPTER II.

GENERAL DESCRIPTION OF THE SKELETON—ANATOMICAL LANDMARKS—ABDOMINAL
TRANSECTION.

GENERAL DESCRIPTION OF THE SKELETON.

§ 204. The softer parts of the body are protected, supported, or
enabled to exert themselves to greater mechanical advantage by a
framework—the skeleton.

The skeleton consists of bones (Ossa), and cartilages (Cartila-
gines), which are more or less closely united at swtwres (Suture), or
movable upon each other at Arthra (joints or articulations). At the
arthra and at some of the sutures the undesirable displacement of
the parts is checked by bands of inelastic fibrous tissue—the liga-
ments (Ligamenta).

Firmer in texture, more definite in outline, and more constant in
form, number and position than most of the soft parts, the bones
and cartilages serve as convenient guides to the identification and
description of the latter, and therefore naturally precede them as
subjects of anatomical study.

The following general account of the skeleton as a whole is given
in advance of the detailed description of the individual bones in
order that the directions for certain preliminary operations may be
more easily understood and followed.

§ 205. Fig. 30.—The skeleton seen from the left.

This figure has been reduced by photography from that of Straus-Durckheim (A, PI.
11), and has been further modified as follows: the dextral costz (ribs) have been omitted
for the sake of clearness ; the last costicartilage has been shortened so as to show its actual

condition ; the principal bones have been named, and the cost and vertebrae have been
numbered ; the shading is likewise altered somewhat.

§ 206. Like the body as a whole, the skeleton comprises a
‘somatic (‘‘axial’’) portion including the bones of the head, neck,
thorax, abdomen, pelvis and tail, and a membral (‘‘ appendicular’’)
portion, including the bones of the arms and legs.

ANATOMICAL TECHNOLOGY.

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THE SKULL AND VERTEBRZ. 89

The membral bones have been shown from the dorsal aspect in
the normal position of the parts in Fig. 6, but in Fig. 30 the animal
is represented from the left side, in one of its natural attitudes while
standing or walking.

In this attitude the limbs are directed ventrad instead of laterad,
and are thus nearly parallel to each other; while their segments
and the general divisions of the somatic skeleton, the head, neck,
trunk and tail, form angles with each other, imparting to the whole
skeleton a graceful and spirited appearance.

§ 207. Skull—(Fig. 56-62).—The cephalic division of the so-
matic skeleton is the skwll, consisting of the cranium or brain-
case, and the face, to which appertains the mandible or lower jaw.
The transverse ridge at the junction of the dorsal and caudal as-
pects of the skull is the Crista lamdoidalis (Fig. 56, Cst. lind.) ;
the darkly shaded area between the cranium and the face repre- —
sents the left orb7¢, and the longitudinal. irregular bar just ventrad
of it is the zygoma, or arcus zygomaticus (Fig. 56).

The Os hyoides will be described in § 224.

§ 208. Vertebree—(Fig. 51-55).—-Caudad from the skull extends
a series of bony segments—the Vertebre—constituting the Columna
vertebralis or spine or spinal column. As seen from the side, the
Columna presents two curvatures in opposite directions, like an
elongated letter s. .

For convenience and more or less naturally, the vertebree may
be grouped in five divisions, cervical, thoracic, lumbar, pelvic or
sacral and caudal. The numbers following the names of these
groups upon Fig. 30 are those which are most commonly observed,
but variations sometimes occur, as will be mentioned in the descrip-
tion of the Columna vertebralis.

The vertebree of each group have certain features in common,
and also individual peculiarities by which, excepting most of the
caudales, they may be distinguished when completely isolated.
On the entire skeleton, the groups are most readily recognized
on account of the connections of three of them with other parts, as
follows :—

The thirteen thoracic rorisbies are costiferous, that is, connected
with the ri4s; the cervical series begins at the skull, and the three
sacral vertebre are united so as to form a single bone—the sa-
crum—to which is attached the Os innominatum on either side.
The lumbar vertebre intervene between the thoracic and the sa-

90 ANATOMICAL TECHNOLOGY.

crum, while the caudal vertebree extend caudad of the last-named
bone.

The first and second cervical vertebree (Fig. 52), are also called,
respectively, atlas and azis. The former is expanded laterally in
wide transverse processes. The latter presents a Spina neuralis,
which is both long and high.

The seventh cervical spine and the first five thoracic are hidden
in Fig. 30. The first nine or ten thoracic spines are directed more
or less decidedly caudad, but the last two or three, like the lum-
bar, are directed cephalad, while the tenth or eleventh has an inter-
mediate direction. The various processes become less and less dis-
tinct among the caudal vertebre, and the caudal members of the
series are little more than subcylindrical segments of bone.

Unlike most anatomists, Straus-Durckheim includes (B, I., 480, Pl. xi., B, C), the
* eleventh, twelfth and thirteenth thoracic vertebre with the lumbar series.

§ 209. Costee—(Fig. 50).—Each costa (rib) is seen to be con-
nected by its dorsal end with the thoracic region of the Colwmna
vertebralis, and at its ventral with a costicartilago. Part of the first
costicartilage appears in Fig. 30 just cephalad of the left shoulder
joint, but the second rib and its cartilage are wholly concealed by
the scapula and humerus.

§ 210. Sternum—(Fig. 49).—The sternum, or breast-bone, con-
sists of a series of eight or nine mesal segments called sternebre.
The caudal piece is the ziphisternum or Ctl. ensiformis, and is
partly cartilaginous. The cephalic segment is the presternwm or
manubrium, and the intervening six or seven sternebre constitute
the mesosternum.

§ 211. Scapula— shoulder blade—(Fig. 438-45).—The ectal as-
pect of this bone, as shown in Fig. 30 and 44, presents a ridge,
the mesoscapula, which has three prominences—acromion, meta-
cromion, and tuberositas.

§ 212. Clavicula—The clavicle or collar bone—(Fig. 48).—In
the cat these bones are small and imbedded in the muscles, with-
out direct attachment to other bones. They are shown in Fig. 30,
one on each side, between the shoulder joints.

A. In the cat the scapula appears as a partof the arm. In-man, however, and in many
other vertebrates, the clavicles are larger and articulated with the scapule and the
sternum. In most reptiles and birds, and in two Mammals (Zehidna and Ornithorhynchus)
the scapula and the sternum are connected by a stout osseous bar—the coracoid—which is
represented in the cat as in man by merely a process—the Pre. coracoideus ; Fig. 43, 45.

ANTAGONISM OF THE MEMBRAL SEGMENTS. gS f

B. The two scapule with the clavicles and the coracoid bones are commonly regarded
as constituting a sort of belt—the scapular arch or shoulder girdle.

§ 213. Pelvis—Pelvic Girdle—(Fig. 51).—This limb girdle is
complete in the cat. Each lateral piece—Os innominatum—is at-
tached to the sacrum by its dorsal end, and ventrad joins its
platetrope (fellow of the opposite side) at the symphysis pubis.
The rounded vertebral end of each os innominatum is the Crista
alii, and the caudal end is the ischiatic tuberosity.

§ 214. Shoulder and Hip Joints.—These are the proximal arthra
of the arm and the leg respectively, forming their points of attach-
ment with the shoulder girdle and the pelvis. Both are ball-and-
socket joints, but the former is the more free, and the position of
the entire joint may be changed on account of the suspension of
the scapula in the muscles.

§ 215. Elbow and Knee.—These are both hinge joints, the lat-
ter being less encompassed by bone, and: hence somewhat the freer
of the two. At the knee the femur articulates with the tibia only,
while the elbow is between the humerus and both the ulna and
radius.

§ 216. Wrist and Ankle.—The latter is a true hinge joint, but
the former combines features of the hinge and the ball-and-socket
varieties. .

§ 217. The Bones of the Limbs.—All of these have been named
in the Introduction in connection with the description of Fig. 6
($$ 82-85), and some will be described hereafter with more detail.
Reference will be made here only to certain general features of the
larger bones, and to the attitudes of the entire limbs.

Antagonism of the Membral Segments.—It will be noted that,
excepting the distal segments, the corresponding segments of the
limbs point in opposite directions, and that the same antagonism
exists between the principal elements of the scapular arch and
the pelvic girdle. .As a necessary concomitant, any two successive
segments, excepting in the case of the manus and antebrachium,
point in opposite directions.

From this relation of the segments there are two results: First,
that the weight of the body rests upon columns which are not only
near its opposite ends, but also tend to counteract each other for the
most part, so that stability is more easily maintained. Neverthe-
less, by exception, the distal segments coincide in direction, so that
both limbs may strike the ground in one direction, and thus propel

92 ANATOMICAL TECHNOLOGY.

the body in the other. Second, these limbs are more elastic than if
the several segments were in the same line, and the muscles act
upon the bones to better mechanical advantage.

§ 218. By some writers (Wyman, 75, 253; Coues, Z, 15), and formerly by the senior
author (5, 45), this opposed or symmetrical or qautitropic relation of the scapula and
ilium, and of the propodial and epipodial bones of the arm and leg has been regarded
as evidence in favor of a general symmetrical homology between the two limbs. The
senior author, however, has admitted (10, 15) that this antagonistic relation is secondary
and telical rather than primary and morphical, and has fully assented to the view that in
their normal position both pairs of limbs extend laterad from the trunk, and their flexures
are in the dorso-ventral rather than in the cephalo-caudal direction.

§ 219. To replace the limbs in their normal and primitive posi-
tion (see § 45), it is necessary to rotate the elbow cephalad and the
knee caudad, and then—if the commonly accepted view be correcet—
to lateriduct both limbs until they are at right angles with the
meson, as in Fig. 6.

This rotation will leave the convexities of the elbow and the knee
facing dorsad (as in Fig. 7), and that of the ankle, with the plantar —
aspect of the pes, facing ventrad. In the arm, however, the corres-
ponding aspect of the manus—the palm—will be left facing dorsad,
and the ulna and radius will be crossed instead of parallel like the
corresponding tibia and fibula. But if the manus be sapinated,
the ulna and radius will be parallel, and the palm will face ventrad
like the sole.

The restoration just described is assumed to have taken place in
the following brief account of some of the bones and their promi-
nences :—

§ 220. The proximal end of the humerus presents an elevation,
the trochiter or Tuberositas major (Fig. 45, 46), which is cephalic
in the normal position of the parts, but lateral in their natural atti-
tude. At the distal end of the same bone (Fig. 46) are two eleva-
tions, the epicondylus and epitrochlea, commonly called external
and internal condyles. In the natural attitude, as seen in Fig. 30,
the epicondyle shows on the left arm, and the epitrochlea on the
right.

The wna projects dorsad and proximad of the elbow as a thick
process, the olecranon. Just distad of the joint, on the ventral side
of the bone, is an elevation—the Processus coronoideus—for the
attachment of the JZ. brachialis.

The proximal end of the radius is the capitellum, while the distal
end of each antebrachial bone presents a short Pre. styloideus.

THE POSITIONS OF THE ARTHRA. 93

The individual carpalia are not easily distinguished, but the O.
pisiforme is seen on the right side ; see Fig. 47.

§ 221. At the proximal end of the femur is a marked process,
the trochanter, which is naturally visible in the lateral view of the
bone, but normally has a caudal position. At the distal end of the
same bone are the cephalic and caudal (‘inner and outer’’) con-
dyles.

At the convexity of the knee, and thus normally dorsad of the
joint, is the patella, which answers in some respects to the olecranon,
but is really only a very large O. sesamoideum.

The ¢idta is seen to be both larger and longer than the fibula,
which indeed does not enter into the composition of the knee. The
malleoli, cephalic and caudal (internal and external), are slight
elevations of the distal ends of the tibia and fibula respectively. Of
the tarsalia, the prominent calcanewm is easily recognized.

§ 222. In ordinary locomotion neither the palm nor the sole are

in contact with the ground excepting at the junction of the metacar-
pal and metatarsal regions with the digits and dactyls; the body is
supported upon the ball of the foot and the dactyls and upon the
corresponding parts of the manus, and the cat is thus a typical
digitigrade. We can imitate its condition so far as concerns the
elevation of the heel and the support of the body mainly upon
the ball of the foot; but the human digits and dactyls can-
not be brought into the state of the cat’s, where the proximal
phalanges are flexed dorsad, the intermediate ventrad, and the
distal ones again dorsad so as to keep the sharp claw points off
the ground.

§ 223. The Positions of the Arthra.—tIt will be noted that the
arthra of the arm are ventrad of the corresponding arthra of
the leg, although the manus and pes are upon the same plane,
and the vertebral ends of the scapula and ilium are at nearly the
same level.

Since there is little difference in either length or inclination
between the humerus and femur, and the radius and tibia, this
difference in the levels of the arthra must be associated with the
greater length of the pes as compared with the manus, and with both
the length and more nearly vertical direction of the scapula as com-
pared with the ilium.

Notwithstanding the popular designation of the wrist of a horse as its “knee,” it
should be kept in mind that the true knee of the mammalian quadruped is a joint

94 ANATOMICAL TECHNOLOGY.

of the leg, and, like its counterpart the elbow, is but slightly removed from the level
of the ventral border of the trunk. The ankle of the quadruped is often called hough
or hock.

§ 224. Os Hyoides and Larynx—(Fig. 30).—Dependent from
the caudal region of the basis cranii is an inverted segmented
bony and cartilaginous arch—the Os hyoides. Connected with
the summit or ventral end of this arch is the larynz, a cartilagi-
nous case forming the principal organ of the voice. (In Fig. 30 the
larynx is placed too nearly in contact with the fifth Vertebra cer-
vicalis).

The keystone of the arch appears in Fig. 30 only by its sinistral
end, shown as a small subquadrate area close to the angle formed
by the junction of the ventral outlines of the head and the neck.
The lateral bar extending from this point caudad and slightly
ventrad is one of a pair of pieces called thyro-hyals, which are
additions to the arch itself, and are most directly connected with
the larynx.

Each lateral half or pier of the arch consists of four segments, as
follows :—

Next to the basihyal is the cerato-hyal. 'Then comes the
epithyal, and then the stylo-hyal. In the figure the dotted line
from the words os hyoides is drawn to the arthron between the
cerato-hyal and epihyal. The three pieces mentioned are bony ;
the fourth piece, which appears in the figure along the side of the
bulla, is cartilaginous, and has been called Cl. stylo-hyoidea. It
is attached at the bottom of a deep pit just laterad of the bulla;
(see Fig. 57, F's. tyh.). The sequence of the osseous segments may
be connected with the alphabetical order of the jouaals of their
names, B, C, #, and V8.

A. For fuller accounts of the Os hyotdes, and for the origin of the names of the seg-
ments, consult Owen, A, II.,506; Flower, A, 128. Straus-Durckheim’s account (A, I, 450-
453) is not very satisfactory. The figures of Mivart (B, 78) are good, but he ascribes to
the cat a small osseous segment—the tympano-hyal—which exists in the dog (Flower, A,
123), but which we have failed to find in even old cats, and which is not mentioned by
Straus-Durckheim.

B. In man the thyro-hyals are disproportionately large, and are called the greater
cornua, While the cerato-hyals are called lesser cornua. Quain, A, I, 55; Gray, A, 206;
Parker and Bettany, A, 305.

The following parts of the larynx may be recognized in the
figure :—
The largest and ventrally placed piece, and that which is reached

ANATOMICAL LANDMARKS. 95

by the dotted line, is the Ctl. thyroidea. In man it forms the mesal
projection known as ‘‘ Adam’s apple.” Just ventrad of it in the
figure, but caudad in the normal position of the parts, is the ring
shaped C#l. cricoidea. Each thyro-hyal segment of the Os hyoides
is directly connected with the larynx by a small Ctl. arytenoidea,
one of which is indistinctly shown in the figure at the dorsal (really
cephalic) end of the prolongation of the Ctl. cricoidea. The epi-
glottis is seen projecting just dorsad of the thyro-hyals.

ANATOMICAL LANDMARKS.

§ 225. During dissection and experimentation it is often de-
sirable to determine the lines and limits of incisions, or to ascertain
the location and outline of parts which are obscured by the skin or
other soft parts. The elevations and depressions which may serve
as guides are called anatomical landmarks.

The landmarks here described should be carefully studied, first upon the prepared
skeleton by the aid of figures and descriptions, and then upon the entire cat by the aid of
preparations of the soft parts, and frozen sections and dissections.

Most of the landmarks are more easily recognized upon the living or freshly killed
animal, but they should be sought also during the continuance of rigor mortis, and upon
specimens hardened by alcohol. Finaily, their recognition should be practised also with
the eyes closed.

Whoever intends to perform experiments should become sufficiently intimate with
some cat to be permitted. to manipulate all the accessible parts. The late Prof. Jeffries
Wyman once told the senior author that in Paris he lived in the same house with Straus-
Durckheim ; and that the indefatigable felitomist would sometimes sit by the hour holding
- a cat, and passing his fingers from point to point over the muscular elevations, the joints
and other bony prominences with which his mind was occupied at that time.

The landmarks form three groups, mesal somatic, lateral so-
matic, and membral.

§ 226. Mesal Somatic Landmarks— Crista lambdoidalis—
(Fig. 56).—Prominent as is this crest upon the prepared skull, it is
by no means easy to find upon the entire animal. The cervical
muscles just caudad of the occiput are very firm and compact, so
that the change of substance is not very marked to the touch.
The crista, however, is nearly in a line with the most caudal con-
vexity of the ears, and may be more distinctly felt during alternate
ventriduction and dorsiduction of the head.

§ 227. Spina Neuralis Axialis—The axial spine—(Fig. 30).—The
somewhat sharp caudal projection of this spine may be felt at the
dorsimeson between the cervical muscles 3-4 cm. from the Crista
lambdoidalis, and not far from the scapule.

96 ANATOMICAL TECHNOLOGY.

Spina Neuralis Thoracica Prima—The first thoracic spinous
process.—This is about half as long again as that of the seventh
cervical vertebra, and larger at the tip than the succeeding thoracic
spines. In the living animal, it is at the bottom of the interscapular
depression, but one or both of the scapulz may be ventriducted so
as to leave it more prominent.

In man, it is the seventh cervical spine which is longer than the rest, whence the
name Vertebra prominens sometimes applied to the vertebra.

Sp. Nrl. Thr. 143—(Fig. 30).—This is a little cephalad of the
vertebral ends of the last ribs, and may sometimes be distinguished
from the other thoracic spines by its greater cephalo-caudal extent,
wherein it resembles the lumbar series. The tenth or eleventh spine
is usually quite short, so as to leave a slight hiatus about 2 cm.
cephalad of the thirteenth. In counting the spines beginning with
the first, the thirteenth will usually appear to be the twelfth on
account of the short one just mentioned. If the lumbar series be
counted, attention must be paid to the point next mentioned.

Spina Lumbalis 7—The last lumbar spine.—This projects just
cephalad of a line between the Cristz iliorum, while the first sacral
Spine projects between the Crista, so.as to be hidden by them in
the figure of the entire skeleton (Fig. 30).

§ 228. Pubes—(Fig. 51).—The cephalic border of the pubic bone
is easily felt both at and laterad of the ventrimeson.

Epigastrium and Xiphisternum—(Fig. 72).—The epigastrium is
a subtriangular area at about the junction of the cephalic and
middle third of the trunk. Its latero-cephalic borders are formed
by the ninth and tenth costicartilagines. The ziphisternum (Fig.
30, 49, 72,) may be felt on the meson in a lean cat, but it is some-
times obscured by fat.

Presternum—(Fig. 30, 49).—This is easily distinguished either
on passing the finger cephalad along the sternum to the neck, or
caudad along the neck until it reaches the somewhat sharply pro-
jecting point.

Larynz—(Fig. 30).—This forms a compressible ventrimesal
prominence about midway between the przsternum and the chin
when the head is dorsiducted so’ as to bring the ventral surface of
the neck and head into the same plane.

Lateral Somatic Landmarks.—These, of course, are in pairs,
but they will be spoken of in the singular number.

MEMBRAL LANDMARKS. 97

§ 229. Zygoma—The Arcus zygomaticus—(Fig. 30, 56).—Both
the dorsal and ventral borders of this may usually be felt distinctly,
although in old males it is more or less obscured by the thickness
of the skin and connective tissue upon the cheeks. The dorsal
border is nearly in line with the lateral angle of the eye.

Diapophysis atlantalis—Transverse process of the atlas verte-
bra—(Fig. 30, 52).—This may be felt as a ridge just caudad of the
base of the ear. The caudal angle is more distinct, and the soft
parts on its ventral side are less prominent and firm than those upon
the dorsal. |

Scapula—(Fig. 30, 44).—The middle of the convex vertebral
margin of the scapula projects dorsad of the intervening cervical
neural spines, so as to give rise to the Depressio interscapularis
which is so marked while the living cat is on its feet. Upon a lean
animal, the following scapular prominences may be easily deter-
mined: mesoscapula, with its tuberosity (Fig. 44); gleno-vertebral
angle (Fig. 48); (the coraco-vertebral angle is so heavily overlaid
with muscle as to be less easily felt); acromion Gig. 44, 45);
metacromion.

§ 230. Costa 13—Last rib.—The abdominal parietes ae caudad
of the last rib are easily indented by the finger almost to the apex
of the triangular area which intervenes between it and the lateral
border of the vertebral muscles (Fig. 30).

Crista ilit.—When the finger is carried along the border of the
vertebral muscles at about the same distance from the meson as the
apex of the angle between them and the last rib, the Crista iit is
felt as a rounded ridge nearly dorsad of the knee (Fig. 51).

Tuberositas ischii—Ischiatic tuberosity.—This is felt as a blunt
prominence ventro-laterad of the anus.

Clavicula—tThe clavicle or collar bone—(Fig. 30, 48, 67, 72).—In
young or lean animals this may be felt by pinching up the skin
and subjacent muscles between the shoulder and the preesternum.

Membral Landmarks.—These, likewise, are in pairs, but are
spoken of in the singular number.

§ 231. Arthra.—After what has been said in the general descrip-
tion of the skeleton (§§ 214-223), there will be no difficulty in ascer-
taining the position of any of the membral arthra. Most of the
bony prominences also may be recognized readily from their rela-
tions to the arthra.

Trochiter—(Fig. 30, 46)—The greater tuberosity of the humerus.—
7

98 ANATOMICAL TECHNOLOGY.

This forms a marked projection at the convexity of the shoulder,
a little ventro-cephalad of the acromion.

Olecranon, Hpicondylus and Hpitrochlea—(Fig. 30, 46).—These
prominences about the elbow joint are recognized without difficulty
even in fat animals if the parts are manipulated between the thumb
and fingers.

M. biceps—(Fig. 74, '75).—The fusiform body of this muscle may
be felt on the ventral aspect of the antebrachium by rolling the soft
parts gently between the fingers upon the humerus. It is less dis-
tinct than in man, on account of the more distal extension of the
insertion lines of the pectoralis group of muscles.

§ 232. Capitellum radii—Head of the radius.—By alternately
pronating and supinating the manus while a finger is pressed upon
the elbow a little ventro-distad of the epicondylus, the capitelluam
may be felt during its rotation.

Processus styloides ulne et radii—The styloid processes of the
ulna and radius.—These are to be felt at the caudal and cephalic
sides of the wrist joint.

Os pisiforme—(Fig. 30).—This forms a marked and somewhat
movable projection just proximad of the wrist, and on the caudo-
ventral border of the antebrachium. Just distad of it is a promi-
nent callosity—the hypothenar eminence (Fig. 105).

§ 233. Trochanter—Trochanter major femoris—(Fig. 30).—This
projects considerably from the hip, a little ventrad of a line between
the Crista ilii and the Tuberositas ischii, and a little nearer the
latter. Its movement is distinct when the leg is moved.

Patella—The knee pan.—When the crus is extended so as to
relax the muscles connected with the patella, this bone is easily
moved from side to side.

Calcanewm.—This forms the marked projection on the ventral
aspect of the leg just proximad of the ankle ; it is sometimes called
the hock.

Malleoli.—These processes of the distal ends of the tibia and

fibula are readily distinguished at the cephalic and caudal sides of
the ankle.

ABDOMINAL TRANSECTION.

§ 234. Since most of the dissections herein described involve
only the thorax, neck, head and arms, it is usually more convenient
and economical to divide the body into caudal and cephalic parts.

ABDOMINAL TRANSECTION. 99

The former may then be thrown away, and the latter preserved, or
dissected while fresh. The kidneys are important visceral land-
marks, and are easily preserved, hence they may be retained with
the cephalic part.

Abdominal transection may be performed alone, but it is more
conveniently done when another person holds the cat in the desired
positions. The assistant, also, may read the directions to the
operator.

§ 235. Instruments and Materials.— Arthrotome; tracer;
medium scalpel; coarse curved scissors; hair scissors; block;
twine, about half a meter; skeleton; wide mouthed jar (about
6x12, 15 or 18 in.); alcohol, 52-67 per cent., to half fill the jar;
coarse syringe ; larga tray.

§ 236. Parts Involved.—tThe following parts are more or less
directly involved in Abdominal Transection. From the figures and
sections referred to, enough should be learned to enable the operator
to recognize them during the operation :—

Aorta.—Fig. 101.

Columna Vertebralis——The spinal column.

Coste—Ribs.—Fig. 30, 50, 73.

Costicartilagines—The costal cartilages.—Fig. 30, 50.

Crista ilii—The crest of the ileum.—Fig. 30, 51.

Diaphragma—tThe diaphragm.—Fig. 90, 101.

Hpigastrium—tThe ‘‘ pit of the stomach.’’—Fig. 30, 72.

fibro-cartilago intervertebralis—The (sixth lumbar) interverte-
bral disk of fibro-cartilage.—Fig. 51.

Hepar—The liver.—Fig. 77.

Intestinwm Tenue—The small intestine.—Fig. 77.

Ligamentum Suspensorium Hepatis—The suspensory liga-
ment of the liver.

Mesenterium.—Fig. '78.

Hsophagus—The gullet.—Fig. 107.

Parietes Abdominales—The abdominal parietes, the muscular
and membranous lateral and ventral walls of the abdomen.—Fig.
77, 101.

Pelvis—The pelvic girdle.-—Fig. 30, 51.

Postcava—V ena cava inferior s. ascendens.—Fig. 101.

Rectum.—Fig. 77.

Renes—The kidneys.—Fig. 79, 101.

Stomachus—The stomach.—Fig. 79, 81.

100 ANATOMICAL TECHNOLOGY.

Thorax—The chest.—Fig. 30, 77.

Vertebrea lumbales—The lumbar vertebra, with their diapo-
physes and zygapophyes.—Fig. 30, 51, 55.

Xiphisternum—The ensiform cartilage of the sternum.—Fig.
30, 49.

§ 237. Operation.—Place the cat dorsicumbent, the head to the
left. Pinch up the right abdominal parietes about midway be-
tween the crista ilii and the last rib.

With the arthrotome, transfix the fold so pinched up, and cut
ento-ectad to the surface. If only the skin is divided at the first
attempt, pinch up the muscles and repeat the transfixion, but be
careful not to include any of the ¢néestines within the fold.

Into the incision so made, insert the left index and medius, the
hand being supinated, and lift the parietes away from the viscera.
Introduce the scalpel, with the edge directed ectad, and divide the
parietes on each side until the thicker vertebral muscles are reached
a few centimeters from the dorsimeson. The dorsal ends of this
transverse incision should be just caudad of the kidneys.

About 2 cm. sinistrad of the ventrimeson, divide the parietes
longitudinally to the pelvis and the epigastriwm, making sure not
to cut the ziphisternum or costicartilages.

Turn aside the four rectangular flaps so formed, and draw the
intestines caudad. Introduce the pronated left hand between the
liver and the parietes until the fingers are met by the diaphragm.
Partly flex the fingers, and push them somewhat dorsad; then draw
the diver and stomach caudad ; this will expose the Tendo centralis
of the diaphragm, which should be punctured with the tracer. The
admission of air into the thorax will permit the farther caudiduction
of the liver and stomach.

§ 238. If the cephalic part is to be preserved, ligate the rectum and then the stomach
and liver, and inject 84-95 per cent. alcohol into the aorta, as directed in § 285. After two
hours a-plaster injection may be made if desired. Then proceed as in § 239.

If the parts are to be dissected fresh, or if the muscles are to be exposed and the thorax
opened so soon as to render the alcohol injection unnecessary, proceed as in § 239.

§ 239. Insert the curved scissors, keeping the convexity toward
the diaphragm, and divide the Ligamentum suspensorium of the
liver, the postcava and the abdominal esophagus; while so doing,
the viscera should be drawn ventrad as well as caudad, so as to put
the parts named upon the stretch.

PRESERVATION AND LABELING. 101

When the liver and stomach are free, draw them and the intes-
tines caudad, dividing the mesal peritoneal attachments (mesente-
rium) to a point 5-6 cm. caudad of the kidneys, but do not remove
the latter. .

Compress the rectum between the fingers so as to force its con-
tents in both directions ; ligate it in'two places about’2 cm. apart,
and cut between the ligatures (Fig. 41). The viscera thus freed may
be thrown away unless wanted for some purpose.

§ 240. Place the block under the cat opposite the kidneys. Press
upon the thick muscles just caudad of the kidneys, and about 2 cm.
laterad of the meson. The siath lwmbar diapophyses (see Fig. 30)
will be felt. With the arthrotome, divide all the soft parts on the
. ventral aspect of the Zwmbar vertebre between the tips of the sixth
diapophyses, and scrape them caudad for about2cm. This will
expose a transverse whitish swelling, the intervertebral jibro-carti-
lage between the sixth and seventh lumbar vertebre.

If the kidneys are not to be kept, or if it is desirable to make the whole preparation
shorter, the columna vertebralis may be divided between the second and third or third and
fourth lumbar vertebre.

Push the arthrotome into this fibro-cartilage, and cut dextrad
and sinistrad as far as possible. Then cut latero-cephalad on each
side to the tip of the diapophysis; then directly laterad so as to
divide the thick vertebral muscles.

Grasp the cephalic part of the cat just cephalad of the incision,
and lift it from the tray. If this does not disjoint the zygapophyses,
bend the caudal part downward until the ligaments give way, and
the zygapophyses are separated. Cut the remaining soft parts and
the skin, and thus complete the transection. The caudal part may
be thrown away.

Knead the thorax so as to expel the blood, place the cephalic
part—which may be spoken of now as ¢he cat—upon a clean dry
tray, or upon paper laid in a tray, and remove the hair, as directed
in Chap. VI.; note the precautions asto the disposal of hair, § 197.

§ 241. Preservation.—Tie the twine firmly about the last lum-
bar vertebra (which is the sixth if the directions have been fol-
lowed), and make a loop through which may be passed a second
piece of twine already attached to the ring of the jar cover, or,
better, an S-hook connected with the cover by a string of suitable
length. To the vertebra should also be tied a fag bearing the brief
record of the sex of the cat, its age or apparent period of growth,

102 ANATOMICAL TECHNOLOGY.

its color, the date of killing, and the name or initials of the dis-
sector ; a similar tag should be attached to the jar. The cat may
then be suspended in the jar head downward ; all parts should be
immersed in the alcohol. If any parts press closely against the
sides, some cotton or ‘‘excelsior’’ should be interposed.

If the cat can be left in the alcohol for at least a week, the parts
are more completely and uniformly hardened.

§ 242. Thoracic Transection.— This is sometimes desirable
when only the abdominal and pelvic regions are to be examined or
preserved.

The primary incision should be transverse, about 2 cm. cephalad
of the epigastrium. The mesosternum may be divided with the
nippers, and the incision then carried on either side in the 7th inter-
costal space. The thoracic viscera are readily separated from the
diaphragm, the cesophagus, aorta, and postcava may be cut 1-2
cm. from the diaphragm, and the dislocation of the columna verte-
bralis effected between the seventh and eighth thoracic vertebree.

If the abdominal viscera are to be preserved, strong alcohol
should be injected into the aorta, and into the abdomen by a slit
just large enough to admit the canula; the contents of the stomach
and rectum should be, if possible, washed out with a stream of
water, aided by kneading; alcohol should then be injected into
both cavities, the cesophagus tied, and the rectum plugged with
cotton.

The abdominal viscera are easily displaced, and it is well to
let the caudal region of the body, with or without the legs, rest
dorsicumbent in alcohol for several days, the jar being securely
closed, and placed on its side ina tray. The alcohol should be re-
newed at the end of a week.

§ 243. Removal of the Tail.—In some cases it may be desirable to remove the tail.

Girdle it with the arthrotome near the base, and divide it with the nippers and bone
scissors. With a young animal, the bone scissors may be used without the nippers.

With a freshly killed animal, when bleeding is undesirable, a twine ligature may be
tied firmly just cephalad of the point of intended removal.

If only the muscles, vessels, and nerves are to be studied, the claw points may be
removed with nippers.

CHAPTER III.

PREPARATION OF BONES—PERMANENT PREPARATION OF SOFT PARTS—THE USE OF
ALCOHOL, ETC.—JARS, ETC.—FROZEN SECTIONS AND DISSECTIONS—INFLATED
PREPARATIONS—MEASUREMENT OF VOLUME AND CAPACITY.

PREPARATION OF BONES.

SpectAL INSTRUMENTS AND MATERIAL :—Arseniate of Soda—Beans or Peas—Benzine
— Bone Drill — Cement — Ether — Glycerin — Labels (§ 162) — Liquid Soap — Macerating
Dishes — Nail or Tooth Brushes — Salt Solution — Syringe — Turpentine Oil — Wicker.
sheimer’s Liquid.

§ 244. There are four principal methods of preparing bones for
scientific purposes :—

(1) Cutting and scraping the soft parts from alcoholic specimens.

(2) Allowing Ants or Dermestes to remove the soft parts of fresh
Specimens.

(3) Maceration (putrefactive) in water.

(4) Boiling with liquid soap.

General Directions.—A. If one can choose his specimen, a
young adult should be selected. In too young animals the epiphy-
ses are apt to separate easily from the diaphyses, and the symphy-
ses open too easily. On the other hand, old animals sometimes
have exostoses, or abnormal growths on their bones, and the sym-
physes and sutures are liable to be entirely obliterated.

B. If possible, have at hand for reference a perfect skeleton of
the part to be prepared, so that the exact position of delicate bones
and processes may be seen, and hence not be lost or broken through
inadvertence.

C. Whatever method is employed, it is better to divide the
animal into several parts by cutting some of the principal arthra,
as the humero-scapular, the femoro-innominate, the occipito-atlan-
tal, and the lumbo-thoracie.

D. Labeling.—The whole animal should bear a label giving the
name, date, sex, and, if possible, the age. Each separated part

\

104 ANATOMICAL TECHNOLOGY.

should bear a label giving the above general data, and also the
name of the part. This is imperatively necessary with the verte-
bree, the ribs, and the phalanges; hence each must be carefully
labeled as it is separated from the rest of the body.

E. If the methods of maceration or heating with liquid soap are
employed, parts like the pelvis and scapule, and limb bones,
exclusive of the manus and pes, which cannot be mistaken, may be
put together and laheled as for the whole animal. Parts that might
be difficult to distinguish should be kept in separate dishes, and
each properly labeled. The vertebre might be divided into the
four sets—cervical, thoracic, lumbar, and sacral; each set should
then be connected by attaching a Manilla hemp string to a wire and
passing it through the neural canal and tying the ends. The order
of the bones cannot then be changed as they separate in the macer-
ating process.

The caudal vertebree that have no neural canal must be num-
bered or put in separate dishes or vials and properly labeled.

The ribs of one side at least should be removed one by one, and
tied in order on a string, or put into separate dishes.

Never put bones of different animals in the same dish, unless they differ so greatly in
size or conformation that confusion would be impossible.

F. The humerus, femur, tibia, and radius should be drilled at
or near their ends, so that the oily matter in the medullary canal
may be removed. The tibia and radius may be drilled in the artic-
ular surfaces, care being taken to reach the center of the thickness
of each bone. The distal end of the femur may be drilled, but the
proximal hole should be made on the ventral side, between the tro-
chanter and the articular head. With the humerus, the proximal
hole may be made in the articular surface, about midway between
the base of the trochiter and the trochin, but cephalad of the slight
extension of the Canalis bicipitalis. The distal hole may be drilled
half way through the diaphysis, from a point on the cephalic aspect,
at the junction of the third and fourth quarters.

After the holes are made, the medullary matter may be broken
up with a wire, and most of it expelled by syringing, first with
warm water and afterward with liquid soap, or spirits of turpentine,
or ether. The syringing should be repeated at the close of what-
ever process is adopted for removing the fiesh.

With most larger animals, and with some smaller ones, it may
be desirable to drill the w/na and fibula also.

MACERATION IN WATER. 105

§ 245. Removing Soft Parts from Alcoholic Specimens.—
Animals that have been preserved in alcohol may have their bones
cleaned by simply cutting and scraping away the soft parts. It
will be necessary to take great care, however, or the delicate pro-
cesses, especially of the skull, will be broken in getting off the
tough connective tissue. After the bones are cleaned as well as
possible, simply allow them to dry, or finish the cleaning as directed ©
hereafter (§ 249).

§ 246. Allowing Ants or Dermestes to remove the Soft
Parts of Fresh Specimens.—The skin and most of the flesh should
be dissected away, and the partially cleaned bones left in a damp
room. Dermestes will find them, and the larve of the beetles will
remove the soft parts.

_If the aid of ants is to be sought, the bones prepared as just
directed should be sprinkled with sugar or smeared with molasses
or honey. Then they should be placed in a box pierced with small
holes. The box should be put by an ant’s nest, and some sugar
sprinkled around the holes leading into it. The ants will clean the
bones more satisfactorily than the Dermestes. It usually takes
about a week for them to clean a cat’s arm.

§ 247. Maceration in Water.—Employ stone-ware, porcelain
or glass dishes, if possible, to avoid discoloration of the bones. The
bones are freed from skin and most of the soft, parts, separated,
placed in separate dishes as directed above, and covered completely
with clean soft-water. The dishes should then be placed in a room
where the temperature does not fall below 18-20 C. Ifthe room is
still warmer, the maceration will proceed all the more rapidly.
The water should be changed on the third day, and again on the
tenth, to avoid discoloration.

It requires from a fortnight to two months for complete macera-
tion. The bones of very large animals may require even a longer
time.

If possible, maceration should be done in a separate building,
and during warm weather. If done during cold weather, the fire
should not be allowed to go out, or adipocere, a waxy substance,
may form, which is difficult to remove. If the maceration is done
in a room or closet, there should be a special ventilating flue (§ 196).
During maceration the bones should be occasionally examined.
When the soft parts separate readily, the water covering them
shouid be carefully poured off, and a gentle stream of fresh water

106 ANATOMICAL TECHNOLOGY.

allowed to play upon them. Use a nail or tooth brush to remove
the flesh, and if itis necessary employ the scissors, forceps, and a
dull but smooth-edged knife to clean some parts; the nippers aid
in tearing off ligaments and tendons. After all the soft parts are
removed, rinse the bones well with clean water, and place them on
white paper in a dry room. Do not fail to accompany each bone
by its proper label (§ 244 D).

The vertebre, ribs, etc., should be kept on a string after cleaning, or when dry they

may be numbered. The skeleton of each animal should be kept in a separate box and
properly labeled.

§ 248. Liquid Soap Process.—The cleaning is done in this pro-
cess by heating the bones in a dilution of the following mixture:
Rain (or distilled) water, 2000 cc. ; strong ammonia, 150 cc. ; nitrate
of potash (saltpetre), 12 grams ; hard soap, 75 grams. .

Prepare the bones by removing the skin and most of the soft
parts, as directed for macerating (§ 247).

Place the bone, or—if several are to be prepared from the same
animal—those that cannot be mistaken for one another, in a vessel
containing water, 4 parts, and liquid soap, 1 part.

Prepare enough of this mixture to completely immerse the bones.
Boil in this forty minutes; then pour off the liquid and add a
similar amount prepared in the same way. Boil again for half an
hour; and usually the muscles may be removed by the hands, a
smooth stick, or a scalpel handle.

As it would take too long for the bones to cool spontaneously before working upon
them, they may be placed directly in cold water.

After removing all the muscles that come off readily, replace the
bones in the dish and continue the boiling until the soft parts may
be readily removed with a nail brush.

When removing the soft parts, it is necessary to be careful not
to lose smal] bones.

After all the soft parts are removed, it is usually best to boil the
bones for half an hour in a mixture of equal parts of the liquid soap
and water to remove the last remnants of grease.

Finally rinse the bones well with clean water and lay them upon
white paper to dry.

This is by far the best method of preparing bones: (1) The
liquid soap saponifies the fat and aids in softening connective tissue.
(2) The bones come out white and free from grease. (8) It requires

PREPARATION OF SKULLS. 107

but a very short time to prepare a skeleton or a part of a skeleton.
(4) It is especially adapted for skulls, as the teeth are much less
liable to fall out, and the gelatinized dental periosteum serves as a
cement. (5) There is no danger of blood poisoning (septiceemia) if
fresh, healthy animals are used. There is no danger in any case
after the bones have been well boiled.

§ 249. Bones are not satisfactorily cleaned by ants or Dermestes. The cleaning may be
very satisfactorily completed, however, by boiling in the mixture of liquid soap (§ 248).
The final cleaning of alcoholic specimens is best done in the same way.

-§ 250. Preparation of Skulls—A. By Maceration.—Separate
the skull, remove the skin, the eyes and the tongue. Then separate
the mandible, but let the os hyoides remain. With a tracer or a
piece of wire, inserted through the Yoramen magnum (Fig. 57),
break up the brain, taking care, however, not to injure the project-
ing bony ¢entoriwm (Fig. 59). After the brain is broken up it
should be washed out with a syringe.

Place the skull and mandible in the macerating dish so that the
teeth shall be uppermost; then, if the water is changed carefully,
the teeth are less apt to fall out and be lost.

The cleaning should be done as described above (§ 247), except
that greater care is usually necessary.

B. By the Liquid Soap Process.—The skull should be prepared
as described for maceration, except that the mandible need not be
separated. Proceed as directed above (§ 248).

Skulls can be much more quickly and safely prepared by the liquid soap process than
by any other.

§ 251. Cements for Bones and Teeth.—The pelvis and man-
dible often separate at their symphyses, and the teeth may become
loose and be in danger of falling out. This latter is especially
liable to occur with macerated skulls. To unite bones, one should
use :-—

A. Liquid gelatin (see Formula, § 1446). Attach the bones
firmly by a rubber band or string while the gelatin is drying. The
method is the same as for gluing wood.

Teeth may be fastened in their sockets by the same substance,
only it is unnecessary to bind them in while the gelatin is drying.
The skull should rest on its dorsal side, and the mandible on its
ventral side, so that the teeth may remain in place during the

drying.

108 ANATOMICAL TECHNOLOGY.

B. An excellent cement, for teeth especially, is the following :-—

Silicate of soda or potassa (liquid glass) mixed to a paste with
powdered chalk. This hardens quickly, therefore it must be used
soon after it is prepared. Neither this nor the gelatin will resist
water.

As soon as a macerated skull is rinsed, the teeth that are loose
should be taken out one at a time, the socket partly filled with one of
the cements and the tooth replanted. In this way the teeth may be
kept in their proper places, and as the skull dries the teeth will be
firmly fixed. Although the teeth of skulls prepared by the liquid
soap process may be loose before the skull is dry, the gelatinized
dental periosteum will usually fasten them very firmly as the skull
dries. If any of the teeth come out they should be replanted as
directed above.

Need of Accuracy,—So far as concerns the general aspect of the skull, the incisors
may be interchanged, and missing teeth may be replaced by teeth from other skulls. It
is to be feared that such substitutions are sometimes made with skulls prepared for sale.
Unless the changes are carefully specified, such skulls have no real scientific value as
regards the teeth.

When two or more of the teeth drop out at the same time, unless direct observation or
comparison with a fresh or alcoholic specimen warrants absolute certainty, it is better to
keep those teeth in a box separate from the rest,

§ 252. Preparation of Natural Skeletons.—By a natural
skeleton is meant one in which the bones are held together by their
natural ligaments. Such a skeleton may be prepared according to
either of the processes described above. One must, however, watch
that the ants may remove only the muscles, or that, in the process
of maceration, only the muscles decay. In all the processes, the
muscles are softened or removed first. If the liquid soap process is
employed, proceed as follows: Boil the bones in the mixture as
directed (§ 248) until the muscles may be removed without much
trouble. It will be found necessary, however, to allow the boiling
to proceed only to the point where the muscles will separate from
the bones by using the hands, a smooth stick like a scalpel handle,
or a dull knife blade. The ligaments will be found considerably
swollen and somewhat softened. * The softened ectal surface may be
cautiously scraped off; then the preparation should be soaked for
3-6 hours in a saturated solution of arseniate of soda (about 25 per
cent.), to poison the ligaments and protect them from Dermestes.
Then the part should be arranged as nearly as possible in a natural

DISARTICULATING SKULLS. 109

position and fastened with pins or strings and allowed todry. The
swollen ligaments will shrink very greatly, so that what might have
seemed a very imperfect preparation when moist will be excellent
when dry. When the specimen is dry, rough projections of liga-
ment may be removed with a sharp knife.

Flexible Natural Skeletons.—If it is desired to have the lig-
aments flexible, the preparation may be soaked after it is partly
dry for from 16 to 12 hours in either Wickerscheimer’s fluid (§ 299),
or a mixture of a saturated aqueous solution of arseniate of soda, 4
parts, and glycerine 1 part.

§ 253. Preparation of the Bones of Young Animals.—The
liquid soap process is to be preferred. But during the boiling the
bones must be carefully watched, and the boiling should be carried
little farther than for making natural skeletons. The epiphyses
must not be allowed to separate from the diaphyses.

The skulls of new born kittens may be nicely prepared in this
way, and the sutures show with great distinctness.

§ 254. Disarticulating Skulls.—Choose a young or barely
mature animal for this preparation, since the cranial sutures are
liable to be obliterated in adults.

Prepare the skull by the liquid soap process (§ 248). Continue
the final boiling for half an hour longer than for a skull that is
not to be disarticulated. While still moist, the bones may be
separated by steady traction. This may be done with the greatest
ease if half grown animals are used.

Skulls that have become dry may be boiled for half an hour in
the liquid soap to soften the gelatinized connective tissue binding
them together.

Macerated young skulls may be disarticulated by carefully
pulling and prying the bones apart.

An excellent plan is to fully disarticulate one side of a skull, and to leave the other
with the bones iz situ.

Disarticulation of Large Skulls.—If a large skull is prepared
by the liquid soap process it should be thoroughly softened by
soaking in water two or three days or by boiling an hour. Then
fill the cranial cavity with dry beans or peas, force a cork tightly
into the foramen magnum (Fig. 57) and place the skull in water.
The swelling of the peas will force the bones apart. Macerated

110 ANATOMICAL TECHNOLOGY.

skulls should be treated as just described, but they need not be
boiled.

§ 255. Bleaching Bones.—In order that bones should be white
and clean, it is necessary that they be relieved of all their grease
and blood. Neither of these ends is accomplished when the flesh is
removed by insects—ants or Dermestes. Both are fairly well accom-
plished by proper maceration; and both still better by the liquid
soap process.

The old method, and the one still largely employed in whitening
bones, is to place them where they are constantly exposed to the
action of the sun, rain and dew. ‘The following methods are, how-
ever, more speedy and satisfactory :—

The blood is usually got rid of in the process of boiling or macer-
ation. If, however, one wishes to prepare bones in the best possible
manner, the entire vascular system may be washed out with normal
salt solution. To do this, insert a canula into the arch of the
aorta (Fig. 101); open the preecava (Fig. 101) just peripherad of the
heart, and then, with a syringe, inject salt solution into the aorta
until it rans uncolored from the preecava.

§ 256. Freeing Bones from Grease.—There are four ways of
removing grease from bones :—

A. By suspending them in spirits of turpentine—Oleum terebin-
thine rectificatum—(ordinary commercial oil of turpentine will do),
for three or four weeks. An indefinite soaking in turpentine will
do no harm if the bones are suspended, and more than four weeks,
may be necessary for large bones. .

The turpentine should be very fluid.

The bones must be suspended so that the thick, oily substance
that settles to the bottom of the vessel cannot touch them.

After the bones have soaked for a sufficient time in the turpen-
tine, they should be exposed to sunlight but not to rain.

B. Suspension in benzine (common commercial benzine will do
very well). The bones should be treated as directed for turpentine.

C. Soaking the bones in sulphuric ether. The bones need not
be suspended, simply placing them in the vessel with the ether will
be sufficient. The ether dissolves the grease very quickly, so that
small bones like those of the cat are entirely freed from grease in a
fortnight or even a less time. The bones should be exposed to light
as directed above.

PRESERVATION OF SOFT PARTS. 111i

Ether is expensive, but the use of it for removing grease from bones does not injure
it for anesthetizing animals.

As turpentine, benzine, and ether are very volatile, they must be kept in tight vessels.
The preserving jars (Fig. 32) answer very well for the bones and either of these agents.

Rither of the three preceding methods may be employed for removing grease from
natural skeletons. The following method is also good for that purpose, but not quite so
safe, as there is some danger of loosening the ligaments.

D. Soaking the bones in liguid soap. Place the bones in a dish
of liquid soap (§ 248) and let them remain for three or four days, in
some cases longer, then wash them very thoroughly with clean
water. Dry them and expose them to the sun (§ 256). It is not
usually necessary to treat bones that have been prepared by the
liquid soap process, but bones that have been macerated or pre- .
pared by insects may be relieved of their grease in this way. It
may be desirable to mix the liquid soap with an equal amount of
water and boil for half an hour or more.

GENERAL REFERENCES TO THE PREPARATION OF BONES.

Baker, E, A, Appendix.

Heath, A, Appendix.
Straus-Durckheim, B, I, 285.
Brown, A, 94.

Witt, A, Appendix. .

Treasury of Natural History, A, 790.

THE PRESERVATION OF SOFT PARTS.

§ 257. Practically, a bone once properly cleaned is imperisha-
ble, and needs only to be protected from dust or injury. But all
the soft parts of the body are more or less prone to decompose at
common temperatures and under ordinary conditions ; even when
treated with preservatives, they are liable to deteriorate unless con-
stantly cared for.

Many agents have been employed for the delay or prevention of decomposition, and
for the permanent preparation of soft parts. Personal experience enables us to speak con-
fidently of only three—cold, arseniate of soda, and alcohol.

A few other agents—brine, methyl alcohol, chloral and Wickersheimer’s liquid—will be
briefly mentioned.

§ 258. Cold—Decomposition is prevented by a temperature of 0 C. (82 F.), and is
more or less retarded at temperatures between 0 and 10.

Cold may be employed alone for freezing specimens so as to keep indefinitely ; more

112 ANATOMICAL TECHNOLOGY.

often, decomposition is simply retarded by it, while the specimen is temporarily protected
by arseniate of soda or permanently preserved by means of alcohol.

Frozen sections and dissections will be discussed.later in this chapter.

§ 259. Arseniate of Soda—Sodium Arsenias.—A saturated solution of this poisonous
salt may be used for the injection of specimens which are to be dissected fresh, or for the
poisoning of inflated preparations.

Water dissolves about one fourth of its weight of arseniate ; hence the saturated solu-
tion is 20-25 per cent. It should not be allowed to remain upon the dissector’s skin
longer than necessary.

Here and elsewhere, when a solution or mixture is mentioned, the menstruum is water
unless the contrary is stated.

ALCOHOL.

§ 260. Alcohol is almost essential in practical anatomy; its
qualities are active, and its management requires constant care.

General Description.—The alcohol commonly employed for
Natural History purposes is, strictly speaking, ethylic alcohol, and
a member of a group including several others, the amylic, butylic,
propylic, methylic, etc. The last named variety will be mentioned
again in § 298.

Ethyl alcohol is colorless, volatile, and inflammable; it has a
vinous odor and pungent taste; it coagulates albuminous sub-
stances and extracts more or less water from organisms immersed
init. Its composition is C,H,O. Its specific gravity is 796.

Absolute Alcohol.—The foregoing statements as to composition and specific gravity
really apply only to pure or absolute alcohol, that is, alcohol which has been freed from
water and all impurities. This, however, is quite expensive (about $8.00 per gal.), and is
required only for some histological purposes.

Ordinary or Commercial Alcohol contains from 5-60 per cent. of water. Most of these

mixtures are commonly called alcohols, but some of the grades have also se names, as
indicated upon the following Table :—

§ 261. TABLE OF SPECIFIC GRAVITIES OF DIFFERENT PERCENTAGES OF ALCOHOLS .
AT 158° C., 60° F

100, .796, Absolute alcohol. 84, .888, Spiritus rectificatus, Br.

95, £809, [Commercial alcohol.] 75, 860.

92, 817, Alcohol fortius, U. 8. 60, 896.

89, 825, Lightest spirit obtained by ordi- 50, 917, [Strong liquors, iluey. etc. |
nary distillation. 49, 920, Spiritus tenuior, proof spirit, Br.

85, .835, Alcohol, U. S., spiritus rectifica- 39, 941, Alcohol dilutum, U. 8.

tus, rectified spirit.
United States Dispensatory, 13th edition, 1880. See also Watts, A, and Baley, A.

Alcohol as received from the warehouse usually contains about 95 per cent. of absolute
alcohol; but that which has been kept for some time, especially if frequently exposed to
the air, is apt to range from 90-94 per cent., on account of evaporation and the absorption
of water from the air.

ALCOHOL. 113

The strong liquors—brandy, gin, rum, and whisky—contain from 45-55 per cent. of
absolute alcohol. A mixture containing less than 20 per cent. is not directly useful in

zoology.

§ 262. The Leading Characteristics of Alcohol.—Kthy] alcohol
has twelve prominent characteristics, of which one half are desirable
and the other half undesirable from the zoological point of view :—

It is simple, cleanly, colorless, and fragrant, generally obtain-
able, and—as a preservative—absolutely efficient.

On the other hand, it is costly, volatile, inflammable, and decol-
orant, quick to absorb water from the air, and—under certain con-
ditions—corrosive of some metals.

§ 263. Alcohol should be used with discretion, always closely
covered, secured from fire, and kept in vessels of glass, hard wood,
copper, zine, or galvanized iron.

§ 264. The Cost of Alcohol.—This, of course, is an extrinsic feature, and varies much
in different parts of the world. In most civilized countries, to the actual cost of its pro-
duction is added a heavy government tax, and the retail price in the United States is about
$2.50 per gallon, or 50-75 cents per liter.

This high price of the liquid best adapted for the preservation of specimens has directly
and seriously retarded all anatomical and zoological progress. At various times between
1866 and 1879, at the request of the late Prof. Louis Agassiz and others, with the co-opera-
tion of the Hon, 8. Hooper and others, Congress wisely made provisions (U. 8. Revised
Statutes, § 3297), by which, under very stringent conditions and with heavy pecuniary lia-
bilities in case of the slightest misapplication, museums and other educational institutions
“may withdraw alcohol from bonded warehouses without payment of tax, for the sole and
exclusive purposes of use in the chemical laboratory, or for the preservation of Natural
History specimens belonging to such institutions.” The cost of alcohol so obtained is
about one sixth of the retail price. See Appendix.

The instructions for so obtaining alcohol for scientific purposes are printed in No. 7,
Series 7 of the U. S. Revenue Department, p. 43, which may be had from the Collectors.

Since no variation from the prescribed forms is permitted, great care must be taken in
making out the application and bond ; those who obtain alcohol annually will save trouble
and sometimes serious delay by having the forms printed.

After making out the form of the application and bond, and inserting the names of the
two sureties, some proprietor of a bonded warehouse should be asked to set aside the num-
ber of barrels (40-45 gals. each) of aleohol desired, and to send a memorandum of the
marks and other items required in the papers. If the forms are printed, a copy of the
application form may be sent, so that the various numbers may be filled in, together with
the number of the collection district in which the warehouse is located. This copy should
be retained for reference in making the assurance afterward required.

The papers should then be promptly filled out, care being taken that the signatures of
the sureties coincide as to initials and abbreviations with the names as entered in the body
ofthe bond. The papers are to be transmitted to the Commissioner of Internal Revenue
through the Collector of the district in which the institution is located. If the papers
have been properly made out, the permit may be received within ten days.

No form is prescribed for the assurance of the Revenue Department that the alcohol

8

114 ANATOMICAL TECHNOLOGY.

has been used for the prescribed purposes within the spesified time. It is necessary to
make oath before the proper officer to this effect, giving the marks of the alcohol and the
date of the original application. This affidavit is to be transmitted to the Commissioner
of Internal Revenue through the Collector of tne district in which the institution is located.

Since it is not always easy to ascertain the location of warehouses, it may be proper to
mention that alcohol may be obtained promptly under the foregoing conditions from Messrs.
Geo. & Thos. Farthing, of Buffalo, in the 30th collection district of the State of New York.

§ 265. Inflammability.—At ordinary temperatures—15-20° C._—a mixture of alcohol
and water containing 30 per cent. or less of absolute alcohol cannot be ignited, and
promptly extinguishes a lighted match dipped into it; 35 per cent. ignites with difficulty,
and the flame is extinguished by the lightest current of air; 40 and 45 per cent. ignite
more readily, but burn gently and slowly. Even 65 per cent. does not burn fiercely, and
the flame is easily extinguished. Specimens saturated with alcohol are more combustible
in proportion to the strength of the alcohol.

Other Inflammable Substances.—Stiil more volatile and inflammable are the etlier, ben-
zine and spirits of turpentine which are used in anatomical work.

§ 266. Precautions against Fire.—Alcohol, benzine, ether, and spirits of turpentine in
bulk should be stored in a fire-proof vault, or in some small building apart from valuable
collections and apparatus. In the laboratory there should be not more than 20 liters of 95
per cent. alcohol, and of the other liquids only enough for current uses. All of them
should be kept in glass or copper vessels, well stoppered and at a safe distance from all
lights and heating apparatus. They should never be opened within one meter of a light,
and if there is a current of air toward the light, the distance should be at least doubled.

When removed from alcohol for examination or dissection, specimens should be washed
off with water, and kept wet with the 15 per cent. glycerin solution, as directed elsewhere.
This precaution is the more essential when anatomical work is done by artificial light.

Cotton and cloths which have been saturated with alcohol or other inflammable liquids
should be dried on trays in the sun or wind rather than near a fire. Common cotton
should be thrown away after use in alcohol, but absorbent cotton may be saved if thor-
oughly dried.

Safety matches are to be preferred. AJ] matches should be kept in metal or glass
boxes. After using, matches should be put into a glass or metal receptacle, and never
thrown on the floor.

Smoking in a laboratory where alcohol is used should be absolutely forbidden.

§ 267. Determination of the Percentage of Alcohol in an
Alcoholic Liquid.—This may be done by means of either a Speci-
fic Gravity Hydrometer or an Alcodmeter (aleoholometer). For
zoological purposes the latter instrument is more convenient and
sufficiently exact.

§ 268. Alcodmeter (alcoholometer).—This is a form of hydrome-
ter or areometer especially adapted to determining the volume or
weight percentage of alcohol in a mixture of alcohol and water.

It is a graduated tube, loaded so as to rest vertically in any
liquid capable of floating it. The alcodmeter of Tralles is com-
monly employed in this country ; it indicates the volwme per cent.

In pure water the instrument sinks only to zero, the lower end

CHANGING THE PERCENTAGE OF ALCOHOL. 115

of the scale. In absolute alcohol it sinks to 100, the upper end.
Mixtures of the two liquids permit it to sink to various depths, and
the number corresponding with the surface of the liquid indicates
the percentage of alcohol by volume.

A. Alcohol that has been used for the preservation of specimens usually holds in solu-
tion or suspension substances of greater specific gravity than alcohol or even water. Their
presence increases the specific gravity of the liquid, and causes the per cent. of alcohol to
appear less than it really is. Old alcohol should therefore be cleared (§ 294), if necessary,
before testing with the alcoémeter; but filtration will not, of course, remove materials
which are in real solution.

B. As stated by Giinther (§ A, 697), the British hydrometer is so arranged that the
zero corresponds with proof spirit, about 49 per cent. The other grades are designated as
so many degrees above or below proof, and two degrees equal but one per cent, For
example, our 95 per cent. alcohol would be 92 above proof, while 20 below proof would
indicate the presence of 39 per cent. of absolute alcohol.

§ 269. Hydrometer Jar.—This is a tall and narrow glass jar,
mounted on a foot. The alcohol to be tested is poured into it, and
the scale may be read through the glass.

Any glass jar of sufficient height (¢. g. the 3x 10 in. jar of Whitall, Tatum & Co., A),
will answer in using the alcodmeter, but the narrowness of the proper hydrometer jar
requires a less quantity of the liquid, and the scale is read more easily. A cylindrical
graduate on a foot, and holding about 500 cc., makes an excellent hydrometer jar, but is
more expensive. Finally, a cheap one may be made by corking one end of a tal] lamp
chimney or piece of large glass tubing, and fixing it into a hole in a wooden disk.

Unless care is sure to be observed in introducing the alcoémeter, a piece of soft sponge
or some cotton should be pushed to the bottom of the jar.

§ 270. Changing the Percentage of Absolute Alcohol in a
Mixture.—This may be done by mixing two grades of alcohol, or
by adding water to one of them. The due proportions may be
ascertained either by experiment or by the arithmetical method
known as alligation alternate.

§ 271. Rule of Alligation Alternate.—Find the difference be-
tween the required per cent. and the per cent. of each of the liquids
to be combined. Write the reciprocal of each of these different
numbers, and reduce the fractions to a common denominator. The
numerators will then represent the proportionate volumes of the
two liquids.

Examples.—W ater and 95 per cent. aleohol are to be so combined that the per cent. of
the mixture will be 50; 95 — 50 = 45; 50 — C0 (the water) = 50. The reciprocals of the
two numbers are 7; and 3; reduced to a common denominator, these fractions become
rey and 4, respectively ; hence 9 volumes of water are to be added to 10 volumes of alco-
hol. On the alcodmeter the per cent. of the mixture will be indicated as about 55.

Again, two grades of alcohol, respectively 75 and 30 per cent., are to be combined so

116 ANATOMICAL TECHNOLOGY.

that the per cent. of the mixture shall be 50; 50 — 30 = 20; 75 —50= 25. The recipro-
cals are 3; and s; reduced to a common denominator, these fractions become ;5, and
xy; consequently 5 volumes of 30 per cent. alcohol are to be added to 4 volumes of 75
per cent. in order that the per cent. of the mixture may be 50. Upon the alcodmeter the
per cent. is about 52.

Owing to the unequal specific gravities of alcohol and water, and the contraction which
occurs when they are mixed, the results obtained by this method are only approximate, as
indicated by the alcoémeter. They are, however, sufficiently close for most purposes.

When liquids of different specific gravities are mixed, they should be thoroughly
shaken together before testing with the alcoémeter.

§ 272. Determining the Ratio by Hxperiment—When a given
volume of alcohol is to be made either stronger or weaker, the end
may be reached experimentally in either of two ways: The entire
volume of the alcohol to be changed may be placed in a jar, and
the modifying liquid —whether water or weaker or stronger alcohol—
may then be introduced gradually until the desired per cent. is
attained ; or a given volume of the alcohol to be changed may be
placed in the hydrometer jar, and given volumes of the other liquid
induced. Having ascertained the ratios, larger volumes may be
mixed accordingly.

In both these cases, the two liquids must be thoroughly shaken
or stirred together before testing.

§ 273. Reduction of 95 per cent. Alcohol by the Addition of
Water.—Since this is the change most frequently made, we have
ascertained by the alcodmeter the results of the mixture of water
and alcohol in various simple ratios. These ratios are given in the
following Table :—

VOLUMES. VOLUMES.
REQUIRED PER- REQUIRED PER-
CENTAGE. CENTAGE.
Alcohol. Water. Alcohol. Water.

~a
a

bb eh RED CD HR OTD

oh ek tek ak ek ek

b9 g0 or
Ph eh ek pk ek pk ek

§ 274. Water to be Mixed with Alcohol.—If the mixture is for the hardening or storage
of specimens, any clean water will answer. But if for the exhibition of finished prepara-
tions, the water should be either distilled, or rain water filtered; otherwise the mixture is
liable to be clouded.

THE ECONOMICS OF ALCOHOL. Lit

§ 275. The Economics of Alcohol.—In the economical employ-
ment of alcohol, four matters are to be considered : (1) The use of
different grades for appropriate purposes; (2) The prevention of
evaporation ; (3) The avoidance of leakage; (4) The improvement
of ‘‘old”’ (deteriorated) alcohol.

§ 276. The Use of Appropriate Grades.—Upon zoological specimens alcohol is em-
ployed for three distinct purposes: preparation ; storage ; exhibition. Different degrees
of clearness and strength are needed for these different purposes, and the safety of speci-
mens, economy, and the appearance of collections depend upon the use of each grade for
its appropriate purpose. For example, the commercial (95 per cent.) alcohol is just strong
enough for some purposes, much too strong for others, and needlessly clear and pure for
others.

The following remarks apply to all vertebrates, and the more general ones to most
invertebrates also. Among the invertebrates the jelly-fishes and some other soft forms
cannot be satisfactorily preserved by means of alcohol, and most of the rest should be
treated like the brains and embryos of vertebrates.

§ 277. Strong alcohol coagulates the tissues so as to form a firm
ectal layer, through which it afterward passes with difficulty.
With a small specimen, the only objection may be the corrugation
and distortion of the specimen. But with a large and fleshy one,
the outside may harden while the interior is actually decomposing.

There is no difficulty in preserving the skeletal muscles and
the limbs, but the brain and abdominal viscera, especially the liver,
are not only more prone to decomposition than the muscles, but
naturally excluded by them from the alcohol. Unless, therefore,
definite measures are taken prior to immersion (§ 286), some of the
viscera will surely fail to be preserved. These measures will vary
according to the size of the specimen and the use to be made of
it, and, under some circumstances, the opportunity for using the
required instruments.

§ 278. The four accessory measures are named in the order of
their simplicity: (1) Freely opening the abdomen; (2) Injecting
alcohol into the thorax and abdomen; (3) Injection of alcohol into
the large hollow viscera ; (4) Injection of alcohol into the arteries.

§ 279. As a preliminary to any of them, the animal should be
bled, if practicable, while under the influence of an anesthetic. As
soon as the cat is quite asleep, the femoral vessels may be exposed
as directed for coarse injections (Fig. 39). and the V. femoralis
divided. When the venous flow slackens, the artery may be opened.
In this way most of the blood in the larger vessels is removed, and
preservation is facilitated. |

118 ANATOMICAL TECHNOLOGY.

§ 280. (1) Freely Opening the Abdomen.—This is sometimes, as
when collecting in the field, the only practicable method. The ab-
domen is opened by a longitudinal incision a little dextrad of the
meson, never—as commonly directed—on the meson itself. A sec-
ond incision is to be made at a right angle with the first, extending
to the dextral margin of the abdominal cavity; these two incisions

are shown in Fig. 76, but the transverse one should not cross the:

meson.

The specimen is to be placed in 52-67 per cent. alcohol, the hand
introduced, and the viscera lifted and moved slightly, so as to per-
mit the penetration of the liquid to all parts; cotton may be inter-
posed. The diver especially should be displaced, and—unless its
preservation is especially desirable—most of it should be removed,
the cholecyst (gall bladder) being left.

§ 281. This method is much more efficacious if combined with
the third, as follows :—

The rectum is compressed so as to expel its contents per anum,
and the small intestine treated in like manner, if its contents seem
to be considerable. The stomach is manipulated and compressed
so as to expel its contents through the mouth. A slit about 1 cm.
long is then made in the free surface of the duodenum near the
stomach, and alcohol injected, first through the pylorus into the
stomach, and then into the small intestine, so as to fill both it and
the large. The escape of the alcohol from the anus may be pre-
vented by a plug of cotton. For all injections of alcohol, a rub-
ber bulb syringe is more convenient than one with a piston. After
injecting, it should be thoroughly rinsed out with water. -

The lungs may be filled with alcohol by passing a curved canula
attached to a rubber tube from the mouth through the glottis, or
by opening the trachea.

§$ 282. (2) Injection of 52-67 per cent. Alcohol into the Thorax
and Abdomen.—This is less efficacious than the other methods, but
may be adopted when it is desirable to mutilate a specimen as
little as possible, as in making a permanent preparation of an entire
animal.

The incisions for the introduction of the canula should be made
obliquely, so as to leave a valvular orifice which is less apt to per-
mit the escape of the injected liquid. Both sides of the thorax
should be injected. Of course this method is more efficacious if
combined with the third.

i ha

INJECTION OF ALCOHOL INTO THE ARTERIES. 119

§ 283. (8) Injection of 52-67 per cent. Alcohol into the Stomach,
Intestine, and Lungs.—tf the left hypochondrium is prominent, or
if itis known that there is much food in the stomach, the entire
abdomen should be compressed, so as, if possible, to expel the con-
tents through the mouth. Pressure of the abdomen just cephalad
of the pubes will probably expel part of the contents of the large
intestine, and most of the rest may be washed out with water intro-
duced from a syringe or from a faucet. Alcohol should then be
injected into the abdomen, as directed in § 282, or the cavity may
be opened, as directed in § 280. In the latter case, both the stomach
and small intestine may be filled from the duodenum. In the
former, alcohol may be injected into the large intestine through the
anus, and into the stomach from the mouth. The anus should be
plugged with cotton to retain the alcohol ; if the stomach is filled
only moderately, the alcohol will probably be retained by it. The
lungs may be filled in either of the two ways mentioned in § 281.

Of course, neither of the three measures above described is
of direct service in preserving the membral muscles or the brain.
These parts are immediately reached by the alcohol only according
to the fourth method, which is efficacious for all parts, but somewhat
more complicated than the other methods.

§ 284. (4) Injection of Alcohol into the Arteries.—This should
be done in all cases when practicable, or unless there are special
objections. With entire animals, or the cephalic or caudal halves,
there is no practical difficulty ; with smaller portions, as the head
or a single limb, it may be necessary to tie or secure with compress-
ors other vessels than the one injected, so as to prevent the escape
of alcohol; but in some cases even this may be omitted, the injec-
tion being done in a dish, so that the escaping alcohol is saved.

The following directions apply particularly to the cat:—

If the entire animal is to be preserved, provide at least 2 liters
of 84-95 per cent. alcohol and a syringe and canula of appropriate
size. After bleeding (§ 279), close the vein by a ligature both cen-
trad and peripherad of the point of division, and have ready a small
compressor for application to the artery. Inject the alcohol into
the A. femoralis, as directed for plaster (see Chap. III.).

Inject the alcohol slowly, so as to give it time for penetrating
the smaller vessels, and stop as soon as the resistance is decidedly
increased, lest the vessels be ruptured. This last precaution is
indispensable if a plaster or gelatin injection is to be made afterward.

120 ANATOMICAL TECHNOLOGY.

Place a small compressor on the artery just centrad of the point
of injection, and withdraw the canula. At least two hours should
elapse before dissection is begun or an injection made with plaster
or gelatin. In the interval the hair may be clipped (see Chap. VI.).
After clipping, if no other injection is to be made, the animal may
be placed in alcohol, 42-55 per cent.

§ 285. If only the cephalic half of the body is to be preserved,
not more than one liter of alcohol may be needed, and the operation
of abdominal transection should be carried as far as to open the
abdomen and puncture the diaphragm ($ 238).

Then, in place of removing the viscera at once, proceed as fol- ~
lows :—

Grasp the rectum as far caudad as possible, and force its con-
tents cephalad. Place two ligatures on it (Fig. 41), about one cm.
apart, and cut between them.

With the scissors and tracer divide the mesentery of the large
intestine and that of the small intestine, to a point opposite the
cephalic end of the left kidney (Fig. 101, 7e7).

Pass a strong thread from this point around the stomach and
liver, 1-2 cm. from the diaphragm, and tie it very firmly. The lig-
ature should cut deeply into the substance of the liver.

With the tracer expose the aorta opposite the caudal end of the left
kidney. Open the aorta as directed (Chap. IV.) for the A. femoralis.
Inject alcohol as directed (§ 284) ; then inject alcohol into the lungs
as directed in § 281. Remove the abdominal viscera by an incision
1-2 cm. caudad of the ligature, taking care not to displace the latter.

§ 286. Treatment of Special Organs and Tissues.—The blood
should be washed off with water or weak brine. Very vascular
parts, like the liver or spleen, should be gently manipulated so as
to expel most of the blood.

In respect to the strength of alcohol required, the soft parts
form three groups, as follows :—

Brains, embryos, the liver, spleen, the glands, and most inver-
tebrates should be laid upon cotton in natural attitudes, first in
alcohol of 52-67 per cent. ; after two days in 95 per cent., fora
week ; lastly, for exhibition or storage, in 75-95 per cent.

Muscular organs, including the heart and alimentary canal,
’ may be hardened and permanently preserved in 42-55 per cent.
The same strength is adapted to most entire animals.

AMOUNT OF ALCOHOL REQUIRED. 121

Ligaments, bones, and cartilages should be placed in 42-55 per
cent. for two days, and then kept in 22-30 per cent.

When the same specimen contains two or more of these kinds of
organs, the strength of the alcohol should be adapted to the more
perishable, provided these latter are to be fully preserved.

For injection into the viscera or abdomen, 52-67 per cent. ; for
arterial injection, 84-95 per cent., is to be preferred, but any
strength above 30 per cent. would be of some service.

While hardening, specimens should be kept in a cool place.

§ 287. Fresh Specimens should not be in contact with the sides
of the vessel. In order that all parts may be reached by the alco-
hol, the specimen should be suspended so as to hang freely, or cot-
ton or ‘‘excelsior’’ interposed between the jar and parts which
would be in contact with it, or the specimen jar laid upon one side,
and shifted daily for a week, so that no part of the specimen is in
contact for more than 24 hours. With well-preserved specimens,
this precaution need not be observed.

§ 288. Flexible Specimens.—If it is desirable that flexible spe-
cimens should harden without contortion, they should be suspended
from the cover of the jar, or the jar itself laid upon the side, as sug-
gested in § 287; it is safer to place the jar upon a tray. The mouth
end should be slightly raised and very securely closed.

§ 289. Amount of Alcohol Required.—With fresh specimens the
alcohol should not be less than twice the volume of the specimen.
The results are more satisfactory if the ratio isas 4:1. Thesmaller
amount may be more safely used with specimens when alcohol has
been injected into the arteries (§ 286).

A. Specimens which have been once saturated with alcohol may be stored or placed
on exhibition in the minimum quantity required to cover them ; in this way a single jar
or can may hold a large number of specimens. But fresh or partly preserved specimens,
especially of viscera, should have plenty of space and abundance of alcohol. Neverthe-
less, experienced collectors are sometimes led to fill a jar with fresh specimens, in the
hope, apparently, that the inevitable laws of decay will be overruled in their favor. In
most cases, a single well-preserved specimen is of more value to science than ten which
have been insufficiently cared for. What is worth preserving at all is worth preserving well.

B. With museum specimens, and for exhibition, the odor of the alcohol is less impor-
tant; but the clearness and strength are essential.

C. Old alcohol, whether filtered or not, may be used for storage, and for the pri-
mary treatment of some fresh specimens.

§$ 290. Provisional Preparations.—lt is not always possible or
even desirable to make the final preparation of a part upon a fresh
specimen, or immediately upon the reception of‘one in alcohol. In

122 . ANATOMICAL TECHNOLOGY.

these cases, however, if the scope of the final preparation is deter-
mined, most of the parts not involved may be removed at once, thus
saving alcohol or storage room, and—if the specimen is fresh—insur-
ing the more complete access of the alcohol. This measure is par-
ticularly important in the case of viscera or massive muscular organs,
and especially the brain of large animals and man. Even with the
brain of the cat, if the aulic region, for instance, is to be examined,
it is well to remove the dorsal and lateral parts of the hemispheres.

§ 291. Deterioration of Alcohol.—During its use upon speci-
mens, alcohol is subject to four kinds of deterioration :—

It may become colored by solution of coloring matters ; turbid
from the suspension of small particles ; offensive from the solution
of malodorous matters; and weak from the evaporation of the
pure alcohol, the impartation of alcohol to the specimen, the ab-
straction of water from the specimen, and the absorption of mcis-
ture from the atmosphere.

§ 292. Purification.—Aside from distillation for the sake of
strengthening, alcohol may be purified and improved in three ways:
settling ; filtration for clearing ; filtration for deodorizing.

§ 293. Settling.—Let the alcohol stand for a few hours undis-
turbed. Place a second jar close to it, so that the first need not be
carried, and pour the alcohol into it very carefully, and without
reversing the tilt until the dregs begin to approach the mouth. If
the alcohol is less than 20 per cent., or if the dregs are very foul,
they should be thrown away. But usually the dregs should be
poured into a more slender jar, and allowed to séttle a second time.

§ 294. Filtration for Clearing.—W hen alcohol is simply some-
what turbid, as usually is the case after the settling, or if its in-
tended use does not require deodorizing, the following process is
sufficient: Push some cotton into the narrow part of a large tunnel,
set the tunnel into a jar, and cover it closely. According to the
compactness of the cotton will the alcohol filter through more or
less rapidly, and with greater or less change of color and clearness.
The same cotton should not be used a second time.

A. Clearing may be effected at the same time with deodorizing, if the perforated lid
of the filter to be described is covered with muslin, and if one or more layers of muslin
are so placed that the alcohol must pass through them before reaching the animal charcoal.

B. During the filtration of alcohol, unless it is conducted into a receiver with a mouth
just large enough to receive the discharging end of the funnel, or the tube connected

therewith, let these pass through a hole in a metal, wooden, or pasteboard cover of
the jar.

ALCOHOL VAPOR. 123

§ 295. Filtration for Deodorization and Decoloration.—This
requires the use of anémgl charcoal, and should follow the settling
and clearing already described.

Any kind of water filter containing animal charcoal may be
used, but the simpler and cheaper forms are sufficient, and the char-
coal should be capable of renewal. Such is the earthenware filter
made for water under the direction of our colleague, Prof. A. A.
Breneman, and for sale by Messrs. Rankin & Son of Ithaca. Un-
less the alcohol is clear, the perforated lid should be wrapped in a
cloth, and two or more layers of cloth placed over the top of the fil-
ter, resting on the lid, so that the alcohol may be cleared of sus-
pended impurities before it reaches the charcoal. In the absence
of a proper filter, a bag of the charcoal may be pushed firmly into
a large tunnel ; the tunnel for this purpose should have the smaller
end larger than usual.

§ 296. Crystalline Deposits—From some specimens, especially brains, strong alcohol
extracts substances which are precipitated as white crystals when the percentage of alco-
hol is diminished or the temperature lowered. The resulting turbidity and clouding of
the glass require a thorough washing of the specimen and the jar, and the renewal.of the
alcohol. The old alcohol should settle in a cool place, and then be filtered through
cotton. Even after filtering, it should be used only for hardening and storage.

When two grades of “old alcohol,” whether filtered or not, are mixed, the deposits
above mentioned are liable to occur; hence, if a clear mixture is desired, a trial should be
made first with small quantities of the liquids.

§ 297. Strengthening.—So far from ‘increasing, the strength of alcohol is likely to be
reduced by the processes of filtration and settling, especially unless precautions are taken
against evaporation. A slight improvement may be effected by treatment with quick-
lime, and distillation is, of course, an efficient means. The readier method, however, is
simply to add to the weaker spirit enough 95 per cent. alcohol to impart to the mixture
the required strength ($$ 271, 272).

When alcohol is purchased at retail, none should be wasted. But if it is obtained free
of tax, it is sometimes cheaper to throw away the weaker grades, especially the dregs after
settling, rather than to spend much time in their improvement.

§ 298. Alcohol Vapor..—The antiseptic and preservative prop-
erties of the vapor of alcohol may be utilized in two ways :—

(1) Upon Fresh Specimens.—When a fresh specimen is to be dissected somewhat rap-
idly, say within one week in warm weather, or two or three in cold, it will keep with
little change if placed in a close vessel at the bottom of which is enough 95 per cent. alco-
hol to keep the atmosphere completely saturated with the vapor. In these cases the skin
should be removed only as needed, and the exposed parts covered, when not under exam-
ination, with cloths wrung out in alcohol.

(2) Alcoholic Specimens.—Any specimen which has been acted upon throughout by
alcohol will keep almost indefinitely in the vapor. Hence, in some cases, especially where
a specimen is under daily dissection, after it has been fully saturated with alcohol, the

124 ANATOMICAL TECHNOLOGY.

latter may be poured off, and a small amount of strong alcohol left at the bottom of the
jar.

In this case, however, if water or the wetting liquid has been applied to the specimen,
a little alcohol should be poured over it whenever it is returned to the jar, or that which
is already at the bottom may be shaken up so as to moisten the surface.

§ 299. Methyl Alcohol.—This is more often called wood spirit or wood naphtha. Its
odor is unpleasant, and it is not used as beverage. In England it is said that no tax is
imposed upon a mixture containing 11 per cent. of methyl alcohol. In this country it is
not subject to tax, but costs about $1.50 per gallon. According to Giinther (A, 697), it is
less efficient than ethyl alcohol as a preservative, at least for fishes. Hence, when ethyl
alcohol can be had free of tax, there is no object in using the methylic variety ; even when
the former costs its full retail price, unless large quantities were wanted, the saving in
cost would hardly compensate for the unpleasant smell of the wood spirit.

§ 300. Wickersheimer’s Liquid.—Several formule for making
this preservative have been published in this country, as, e. g., in
‘*The Popular Science Monthly,’’ March, 1880, p. 717; ‘‘ The Med-
ical Record,”’ April 17, 1880, and April 30, 1881, p. 501.

In the last named, it is stated that the original formula has been altered, and that
Messrs. Poetz & Flohr of Berlin prepare two kinds, one intended for injections, and the
other for immersing bodies. Their composition is as follows :—

Injection. Immersion.
ATRONIOUN ACIET: v 6civice'e iss esib 0. vse odes 16 = grams. 12 grams.
Badinm CHING 255.200 estes 6s cae" 80 e 60 s"
Potassium sulphate. .......+...+++++-- 200 i 150 %
Potassium nitrate... cee ee es 25 2 18 ce
Potassium carbonate............. 22+. 20 Sf 15 ¢
PAN BAL OR ANG aos! kw dig a8 XS Se Ween ele as 10 __—iliters 10 __—iliters.
REEY CARIN sa, 552 aru & wae Maes tee on 4 st 4 “
Wood WIA PUENS wots os Mictiia = cava secs 80 ao so. 8

According to the previous article in the “‘ Record,” the various salts are to be dissolved
in the boiling water, and the solution is to be cooled and filtered before the other two
liquids are added. It is probable that the cheaper glycerin will answer, and that ordinary
(ethyl) alcohol is to be preferred to the methylic variety which is specified.

Application.—Preparations that are to be preserved dry are immersed in the liquid for
6-12 days according to size, and then dried in the open air.

Hollow organs, like the lungs, must be filled with the liquid, then laid in a vessel of
the same, and afterward distended with air and dried.

Our own experience with this liquid does not enable us to give a decided opinion as to
its merits. We are disposed to think that it will answer a good purpose with preparations
of the ligaments, and of hollow viscera where flexibility is desired. With dry inflated
preparations, the cheaper and simpler arseniate of soda is equally efficacious, while all
ordinary “‘ wet preparations” are, in our opinion, more surely and conveniently preserved
by alcohol.

§ 301. Chloral Hydrate.—A solution of this substance has been used by Dr. W. W.
Keen and some other anatomists. The results seem to be satisfactory in most respects

TEMPORARY STORAGE. 125

so far as concerns man and other Vertebrates, but less so with the Invertebrates, at
least as reported by Prof. A. -E. Verrill in a letter to Dr. Keen.

Dr. Keen has published two papers upon the subject (7 and 2), and kindly permits us
to print the following brief statement of his experience up to November 1, 1881 :—

“ As to the strength of the solution, I should use 20-80 grains to the ounce of water.
[This is 4-6 per cent., or in the proportion of 1 gram of chloral to 24-16 cc. of water. ]
For the Invertebrates and for vegetable tissues, my own experience, though limited, is
favorable, It preserves vertebrate organs, excepting the brain, for a few years at least.
I have had no failure, and some of my specimens are now nine years old. The colors are
rather less affected than by alcohol. The jars do not need to be hermetically sealed, hence
the specimens are always accessible. The specimens are also less apt to dry when exposed.
The cost of the solution is much less than that of alcohol on which the tax is paid. For
the preservation of human subjects for dissection, it is most excellent, excepting that
it will not keep them very long in hot weather, and is not well adapted for keeping them
over the summer. For use in cool and cold weather, and especially for the dissection of
nerves, it holds its own.”

The foregoing statements from so distinguished an anatomist certainly warrant a care-
ful trial of chloral; our own experience is as yet too limited for the publication of the
results. )

§ 302. Brine.—A saturated solution of rock or dairy salt is sometimes used alone for
the temporary preservation of anatomical material ; it-is said to be more efficacious when
the specimen is previously injected with a saturated solution of arseniate of soda, In one
of the leading medical schools of this country this plan is successfully and economically
followed for keeping human subjects even through the summer months.

§ 303. Exhibition and Storage of Alcoholic Specimens.—As
was stated in § 262, while alcohol is a perfectly efficient preservative
so far as concerns all vertebrates, its cost, volatility, and corrosive
action necessitate certain measures which may be conveniently dis-
cussed in connection with the general subject of the storage and
exhibition of specimens.

§ 804. Temporary Storage.—For this purpose, and for brief
transportation, alcoholic specimens may be placed in vessels made
of wood or earthenware or any kind of metal; but vessels so em-
ployed should be carefully examined as often as once a month, so
as to guard against evaporation, leakage, or rusting.

Leakage or evaporation are readily detected from the diminution of alcohol or the
dampness of the bottom of the vessel or of thé floor, but rusting may not be apparent until
loss or damage has occurred. When alcoholic specimens are kept in tin ware, the metal
is certain, sooner or later, to be corroded at some point of contact with a specimen. A
mass of rust is formed which may prevent the eseape of the alcohol so long as the speci-
mens are undisturbed. But this rust is liable to be dislodged by any movement, or even
by a blow upon the side of the vessel, and thus permit the escape of the alcohol.

§ 805. Leakage from Imperfect Glass Vessels—Small jars and vials sometimes have
small holes or cracks which escape notice at the time of filling, but which permit the loss
of alcohol and the damage of the contents. In some cases, part of the bottom of a small
jar may be so thin that it is pulled off by simply adhering to the paint of a shelf.

126 ANATOMICAL TECHNOLOGY.

§ 806. Corks should be used only for brief transportation or temporary storage. The
best of them are insufficient barriers against either evaporation or leakage, and the poorer
ones should not be used at all with specimens. Corks may be rendered more secure by
soaking in oil, or covering with Brunswick black, or with a solution of paraffine in ben-
zine, benzole, or turpentine. Rubber stoppers are sometimes used.

§ 807. Glass Dishes and Bowes.—The anatomist has use for glass dishes of almost every
size, A few sizes are kept in stock by Messrs. Berge (A, No. 257), and Whitall, Tatum &
Co. (A, No. 2265). Covers for them may be cut from window glass, or these or other
sizes may be ordered to have the edges ground for the reception
of covers ground near the edge.

The covered box shown in Fig. 31 is very useful for the hard-
ening of brains and other small specimens. The largest size ad-
vertised by the firms above mentioned (Nos. 202 and 2590) has a
capacity of nearly 500 cc., and costs $3.80 per dozen.

The covers of these boxes and dishes do not fit accurately, and
their contents should be under constant supervision.

§ 308. Metal Boxes.—As the name implies, the box usually
differs from the jar or the can in its relatively greater horizontal
extent and in having a cover which is coextensive with the box,

Guass Box; x.25; and is readily removed and replaced. The accessibility of the

8 306. ” contents thus compensates partly for the evaporation of the alco-

: hol which must occur in some degree. The cover should fit
closely and have a wide flange, but such a box should be under constant supervision.
Large boxes should be supported by an outer box of wood.

For the preservation of cats while under occasional examination, a box of galvanized
iron may be 60 cm. long, 40 wide, and 25 deep. An entire cat may rest in it lengthwise,
and either the cephalic or caudal half crosswise. Around the inside, half way from the
bottom, extends a ledge on which may be laid a metal plate perforated with holes 2-3
cm. in diameter. On this plate may be placed a second tier of specimens, which are thus
kept from pressing upon those at the bottom. If preferred, the bottom may contain only
alcohol, the vapor of which will suffice for the keeping of the specimens upon the plate,
provided they have been already thoroughly saturated with alcohol. The box may be
supported upon bosses or upon short movable legs. The cost of such a box is $4-$5.

Fie. 31. — COVERED

§ 309. Exhibition or Permanent Storage.—For these purposes,
and for transportation occupying more than a month, alcoholic
Specimens can be safely entrusted only to tightly closing vessels of
glass, copper, zinc or galvanized iron. Of course, glass must be
used for exhibition ; it is also cheaper than metal for tightly closing
vessels, provided the risk of breakage is not regarded.

§ 310. Metal Cans.—Three kinds of metal cans are useful in connection with alco-
holic specimens. For bringing alcohol from the barrel, and for containing the supply for
current use, the ordinary five-gallon oil can is well adapted, especially if provided with a
faucet from which the alcohol may be drawn into jars without lifting or tipping the can.
The small gallon or half-gallon can is desirable for pouring the alcohol into small vials.
These cans may be made of tin, but copper is more secure.

Screw-top Cans.—For the permanent storage of alcoholic specimens, especially if occa-
sional moving is necessary, copper cans with screw-tops are desirable. They are more

EXHIBITION OR PERMANENT STORAGE. 127

expensive than jars of the same capacity, but are less subject to injury, especially during
transportation.

A convenient size has the following dimensions: Height, 30 cm.; diameter, 40 cm. ;
diameter of the orifice, 26cm. ; capacity, 30-35 liters. The rings of the screw-top are made
of brass, and should not weigh over 1300 grams. The bottom should be protected from
abrasion by bosses. (At the Museum of Comp. Zoology in Cambridge each can is enclosed
in a wooden case which facilitates handling and may be used in transportation.) The edge
of the cover-ring is notched for the admission of the iron bar with which it is screwed or
unscrewed. Such a can costs $10-$12; this is more than the cost of a glass jar of
equal capacity, but the latter is liable to break, especialiy during transportation, while the
can is practically indestructible.

§ 311. Glass Jars.—With the exceptions indicated in the fore-
going sections, glass is to be preferred for all alcoholic specimens.
Glass jars may be considered in five groups: fruit jars; specimen
jars with covers ; specimen jars with neck and ground glass stop-
pers ; welted jars; compressed jars.

§ 312. Fruit Jars—There are many styles of these, but most of them are made of
more or less opaque glass. The orifice is seldom more than‘ 5,5 cm. in diameter. They
are thus unsuited for exhibition or for holding wide specimens; but their cheapness and

strength adapt them well for the storage and transportation of such specimens as they
will contain.

Fie. 82.—WIDE MovuTHED SPECIMEN JARS WITH COVER; § 312.

§ 313. Wide Mouthed Jars with Covers—(Fig. 32)—These are made on the general
pattern of the ‘‘ Millville” fruit jar, but are of clear glass, and have mouths nearly as
wide as the jars; the cover has a ring from which specimens may be suspended. Messrs.
Whitall, Tatum & Co., in addition to what is said in their catalogue (A, 2600), will send a
price list of 13 sizes, ranging from 4x3 in. to 23x9. The following special lengths of
standard widths have been made by the same firm at the following prices for each jar:
18 x3 in., $1.15 ; 23 x 4, $2.05 ; 32 x 4, $3.30; these tall jars are provided with a ‘‘ foot.”

These jars are of course less handsome than the glass stoppered kind, but their strength
and cheapness well adapt them for museum and laboratory use.

128 ANATOMICAL TECHNOLOGY.

§ 314. Glass Stoppered Jars.—These are made to order by any extensive glass manu-
factory. The Dorflinger Glass Company, White Mills, Wayne Co., Pa., issue a price list of
51 different sizes, ranging from 2 x 1 in. to 22 x 7.

§ 815. Welted Jars—(Fig. 33).—With the specimen jars above described, the neck is
strengthened by a constriction. This involves one of two alternatives: either the speci-
men must be more or less compressed in
entering or leaving the jar, or the body
of the jar is needlessly large. With
some kinds of specimens these are not
very serious objections. But with brains
and embryos it is desirable that all pres-
sure should be avoided, and also that
they should be close to the side of the
jar. For such specimens the jars should
be of uniform diameter throughout, and
the requisite thickening at the mouth
may be gained by a welt.

The size represented in Fig, 33 is
adapted to the brain or the heart of the
cat. Its inside measures are 4 cm. wide,
and 6 cm. to the lower border of the part
which is ground for the stopper. A
smaller size of the same height, but
only 3 cm. in diameter, is adapted for
either half of the brain. Both sizes are
made to order by Messrs. Whitall, Ta-
tum & Co, for $2.50 per dozen.

§ 816. Compressed Jars.—The ordi-
nary circular jar is poorly adapted for the
display of flat specimens like frozen sec-
tions and some fishes. Messrs, Whitall,
Tatum & Co. have molds for two sizes of
compressed jars similar to the photog-
raphers’ ‘‘ bath.” They are 15 cm. high
and 21 or 12 cm. wide. The larger cost
$12 per dozen, and the smaller $6. The
tops are level and ground off for thin
glass covers, which may be cemented on.
The covers cost a small sum in addition
to the price of the jars.

Fic. 88.—WELTED VIAL FOR THE BRAIN OR
HEART OF THE CAT; slightly reduced ; § 814

§ 317. Cleaning Jars.—When large enough, jars should be
washed on the inside with a sponge. If they will. not admit the
hand, the washing may be done with a swab made by tying a
sponge upon the end of a stick, or with the bottle brushes, one of
which is shown in Fig. 34. For long jars and large tubes there are
bottle brushes with long handles; or a wire may be attached to the
handle of a short brush ; or the ring of the handle may be cut off,

DISPLAY OF ALCOHOLIC SPECIMENS. 129

and the end of the wire let into a hole in a stick of the desired length.
If the jar is greasy, it may be cleaned perfectly by means of the
liquid soap (§ 248).

After washing, glass jars should be well rinsed with clean water,
and dried with a soft but not linty towel, and finally—if for the
exhibition of specimens—polished inside and out with a bit of old
silk or chamois leather.

Fic. 34.—Bortte BrusH ; reduced; § 316.

§ 318. Display of Alcoholic Specimens.—Of course the alco-
hol should be clear and the jar clean; but as the jars are commonly
cylindrical while many specimens are more or less compressed, the
surface of the specimen is sometimes undesirably distant from the
side of the jar, and the image is distorted by the intervening liquid.
When the compressed jars mentioned in § 315 are not available, a
smaller bottle or jar of clear glass may be introduced so as to crowd
the specimen against one side of the jar. The inner jar must be
loaded with lead or filled with alcohol or water to such an extent as
to just sink it in the alcohol. If water is used, the smaller jar must
be very tightly closed. See Appendix, § 1456.

As a rule, an exhibition jar should contain only one specimen.

§ 319. Packing Alcoholic Specimens for Transportation.—
There are certain precautions of general application, but the details
vary according to the nature of the specimens and the conditions of
transportation. .

In most cases the specimens should be packed before the alcohol
is poured in, and the vessel should always be jilled.

Unless a pail i is used, or a box or basket with an unmistakable
handle, and ‘This side up”? prominently inscribed, the package
should be prepared for any position.

In respect to transportation, specimens may be grouped as
coarse, delicate, and scaly.

Coarse Specimens.—Under this head come most entire examples
of the larger number of vertebrates. These, or their firmer parts,
may be packed with no precaution other than to fill the vacancies
with hay or ‘‘ excelsior”’ before introducing the alcohol.

9

130 ANATOMICAL TECHNOLOGY.

Scaly Specimens.—Most ‘‘ fishes’”’ and some Reptiles should be
wrapped in gauze or netting, or any porous cloth or soft paper.
The wrapper should be secured with a string.

Delicate Specimens.—The delicacy may be due to smallness or
softness, or to the presence of projecting parts which are liable to

injury.

The safest way is to put each specimen in a separate vial or jar
quite full of alcohol, or in a small box with saturated cotton which
may be immersed in a larger jar or can.

When several delicate specimens are to be packed in the same
vessel, they should be separated by layers of cotton thoroughly
saturated with alcohol. After the alcohol is poured in, the jar
should stand for an hour at least to allow time for settling. If
any occur, more cotton should be put in.

Packing without Alcohol—When the time of transmission by
mail or express is short, specimens may be safely sent if covered
with a layer of alcoholic cotton, then wrapped in rubber sheeting,
and packed in a wooden or metal box, or in a vial properly pro-
tected.

Secure Closure of Vessels —Always important with alcoholic
specimens, this is essential before transportation. In all cases the
vessel should be laid on its side or stood upon the upper end after
closing, so as to determine the possibility of leakage.

The glass stoppers should be anointed with glycerin or fine oil,
or a solution of paraffine in benzine or turpentine, and pushed in
with a slight screwing motion. The jar should then be rolled in
cloth, and the cloth turned tightly over the upper end of the jar and
tied down so as to secure the stopper.

The covers of fruit jars and specimen jars should be screwed down
more firmly than usual. If possible, all jars should stand upright
during transportation, and be well packed in hay or other soft
material.

Welted Vials may be let through holes in a board so as to be
supported by the welt. The board may rest on cleets in a box.

Packing boxes of tin are usually closed by soldering.

When earthen jars are used, the corks should be pushed below
the level of the rim of the mouth, and the space filled up with a
thick paste of plaster of Paris.

§ 820. Miscellaneous Suggestions. — Specimens having prominent appendages,

whether arms, legs, wings, fins or spines, especially if they are stiff or angular, should
be put into jars tail first, so that their removal may be unobstructed.

FROZEN SECTIONS. 131

This rule may sometimes require modification, as with some “ fishes” with delicate caudal
fins, which might be broken by the pressure. The specimen may be suspended from the
cover of the jar, or the tail may rest upon cotton, or, finally, the jar may be of such size as
to permit the withdrawal of the specimen tail first.

§ 321. In some cases, when a delicate or valuable specimen is in a jar or vial with a
mouth too small for its easy or safe extraction, the jar should be sacrificed. Place its
mouth just over the edge of a waste pail or box, and rap it smartly with a hammer so as
to break off the top. In removing the specimen, avoid the bits of glass which may have
fallen into the jar.

When the glass stopper of a jar cannot be removed in the ordinary way, tap the han-
dle on both sides, alternately, with a piece of wood or the edge of a razor-strop. If this
fails to loosen the stopper, or if the handle breaks off, the jar may be broken open as
directed above.

§ 322. In removing large specimens from alcohol, especially if the hair or feathers
remain, squeeze the alcohol out with the hands, then suspend the specimen for a short
time from a hook over the jar or some other receptacle, and finally rinse it off with a
stream of water. In this way some alcohol is saved, drying is retarded, and the dissector
avoids the odor and stimulating effect of the vapor of the alcohol.

FROZEN SECTIONS AND DISSECTIONS.

§ 323. Frozen Sections.—These are sections of desired thick-
ness made of a specimen which has been frozen hard so that the
parts retain their natural relative positions.

Such preparations have been made in Europe since 1833, and in some cases they have
been preserved as permanent preparations. A series of frozen sections of the head, in the
museum of the Medical School of Maine, were made by Dr. Thomas Dwight, and formed
the basis of his work on the head (A). See also his more recent work (B).

Frozen sections of a cat were made by us on the 2ist of Jan., 1879, and were briefly
described by the senior authorin 22, The method was as follows :—

§ 324. The cat was killed with chloroform, the arteries injected
with red plaster and the veins with blue. It was then carefully
supported in a natural attitude in a box of hay, which was placed
out of doors for three days. The cat was then perfectly rigid, and
was rapidly cut with a sharp wide-bladed saw into transections
about 1 em. thick. The cutting was done in a cool room, and each
section when made was placed upon a glass plate, held under a
gentle stream of water, and both surfaces freed from hair and fat
particles with a soft nail brush. It was then laid on one side in a
dish of 95 per cent. alcohol, and put in a cool place.

As the sections thawed, they were hardened by the alcohol so
as to retain their form. Each was then mounted in a compressed
jar (§ 316). In some cases the viscera were secured from falling
out by means of insect pins. The cavities of the heart were better
seen after the removal of the plaster.

132 ANATOMICAL TECHNOLOGY.

§ 325. The foregoing is the method followed in making the transections shown in
Fig. 99 and 100. The following modifications may be desirable :—

1. The animal should be bled, when anesthetized, as directed in § 279.

2. Probably sawdust would be better than hay for support during the freezing.

8. The freezing was done in winter, but artificial cold might be produced at any time.

4, More satisfactory results might be reached by making sections of only part of a sin-
gle individual. For example, the thoracic transections would be more true to nature if
the lungs had been filled with water from the trachea ; this, however, would have spoiled
the neck. In like manner the stomach and intestine or other hollow organs could be
distended to their normal size.

5. For the middle region of the abdomen, including the intestines and part of the
uterus and urocyst,a more satisfactory result might be reached by filling those organs
with water, and keeping up the pressure during the freezing. A sharp broad-bladed knife
could be used to transect the abdomen ventro-dorsad, and a narrow-bladed saw used for
dividing the vertebra.

§ 326. Frozen Dissections.—While frozen sections display the actual relative posi-
tion of organs which lie in a given plane, they are unsatisfactory for the same reason that
microscopic sections often are : it is rare that a complete view is afforded of any aspect of
an organ. Hence we believe that for many purposes there should be a combination of
freezing with ordinary dissection. For example, with a frozen cat, most of the thorax
could be removed with the saw. Then, before thawing took place, all the rest of the tho-
rax could be cut or nipped away so as to expose the entire cephalic surface of the dia-
phragm, with the csophagus, great vessels and nerves projecting for a short distance.
The pelvic region could then be removed, and the preparation mounted in strong alcohol
so as to retain its form.

§ 327. Flexible Preparations of Muscles.—Dr. Thomas Dwight has published (2) the
results of experiments by himself and others. We are unable to contribute anything to
the subject.

§ 328. Preparation of Hollow Viscera.—<Aside from preserva-
tion like other soft parts, the stomach and czecum, the lungs, the
urocyst (urinary bladder), and cholecyst (gall bladder) may be pre-
pared by permanent inflation with air or alcohol so as to display
their size, form and subdivisions with more or less of their texture.

Since the stomach is most frequently prepared in this way, the
following directions apply more directly to it, but they may be
readily modified for the other organs named. The parts of the
stomach are shown in Fig. 81.

§ 329. Removal.-—The viscus should be removed from the body
-as soon as possible after death. If, however, the stomach or ce-
cum has been freed from its contents as described in § 283, the
removal may be longer delayed.

There should be left attached to the viscus a portion of each
canal continuous therewith, about 5 cm. long if possible. With
large specimens this length may be greater, and with small ones it
must sometimes be less. To secure so much of the cesophagus of

Peet aac

PREPARATION OF HOLLOW VISCERA. 133

the cat, the diaphragm must be cut through ; after division of the
tube, a cirelet of the diaphragm may be left attached thereto.

§ 830. Cleansing—The organ should be manipulated in water
so as to expel the contents and dislodge the mucus from the ental
surface. When possible, as with the ceecum and with the stomachs
of some of the lower vertebrates, the organ should be everted. In
any case the ental surface should be thoroughly cleansed with a
stream of water from a faucet or syringe.

If desired, the capacity of the viscus may be measured as di-
rected in § 334.

Normal salt solution should then be thrown into the organ, and
it should be allowed to soak in the same for a few hours, or until
the blood is removed. If any part projects above the surface, it
should be covered with a layer of absorbent cotton.

§ 331. Zrimming.—After sufficient soaking, expel the n. s. s.,
and place the organ upon a clean tray or dish. Provide two com-
pressors or some linen thread, blowpipe, coarse forceps and coarse
scissors curved flatwise.

Close the free end of the cesophagus with a compressor or liga-
ture. Into the duodenum introduce the blowpipe, inflate the organ
to a moderate degree, and close the orifice with a compressor or liga-
ture. If the latter is employed, the orifice may be controlled by
the fingers of the operator or of an assistant while the thread is
applied.

In trimming, the fat and vessels and connective tissue are to be
grasped with the forceps, and cut off close to the viscus. The con-
vexity of the scissors must be kept toward the organ, and care
taken not to wound it with the point of the forceps.

The subsequent steps in the operation vary according to the
agent—air or alcohol—to be used for the permanent inflation.

§ 332. Inflation with Alcohol.—This is better adapted to the
lungs, and to delicate specimens which might not withstand the
pressure and manipulation involved when air is employed.

Place the organ in 42-55 per cent. alcohol, in a dish, or better i in
the jar in which it is to be preserved. Cut off the ligatured smaller
end, and secure in the orifice the canula of a syringe, or a canula
connected by a rubber tube with the canula of a syringe; place a
ligature at the orifice ; then distend the organ with the same per
cent. of alcohol. If a bulb syringe is used, or if the injecting syr-
inge is provided with a cock, it is only necessary to tighten the lig-

134 ANATOMICAL TECHNOLOGY.

ature at the time of desired distension ; otherwise, the reflux of the
alcohol may be prevented by a small compressor.

The jar selected should be so large that the inflated organ may
swim without pressure against the sides. It may be kept from the
bottom either by suspending it by a thread from the loop on the
jar cover, or by attaching a piece of cork or a bulb of thin glass.

§ 333. Inflation with Air, and Drying.—This method is less
expensive, but more complicated :—

After trimming, cleansing, soaking, and trimming as above di-
rected ($$ 330, 331), the organ is to be partly filled with a saturated
solution of arseniate of soda (§ 259), and placed in the same. The
projecting part should be covered with absorbent cotton, and the
whole should be turned at least once. According to size, it should
remain in the solution for from 3-12 hours. If left too long, the
tissues are gelatinized and rendered incapable of withstanding
pressure and manipulation.

Expel any liquid contents as completely as possible, and let the
organ drain from a clean smooth surface.

Select two fine-grained corks adapted respectively to the two ori-
fices. With a rat-tailed file girdle each with a furrow at about the
middle of the length. Perforate the larger, and fit very closely into
it a piece of glass tube projecting about 3 cm. from the larger end.
Fill the grooves with mucilage, and secure each cork by winding
about it at the level of the groove a string or rubber band.

To the glass tube attach a rubber tube. Inflate the organ, and
apply a compressor near the glass tube. Put a tack or a small
screw-eye into each cork, and suspend the organ from screw-hooks
in a natural position, in a warm but not dusty place. If the organ
is large, or drags too heavily upon the slender cesophagus and
intestine, support it by bands of parchment or oiled paper.

Connect the rubber tube with a gas jet, or with the outlet of a
gasometer, or other apparatus by which continuous pressure may
be made. Remove the compressor, and turn the gas on cautiously,
so as not to distend the organ unduly.

The escape of gas will be slight, but its accumulation should
be avoided, and the place well ventilated.

If no artificial means of inflation are available, air may be blown
in from the mouth, or injected with a syringe, but in these cases
constant attention is required to prevent collapse.

T0 MEASURE THE CAPACITY OF AN ORGAN. 135

When the organ is perfectly dry, the ends containing the corks
may be cut off, and fresh corks secured with mucilage only. In at
least one of the corks should be a screw-eye to which the label may
be attached, and by which the specimen may be suspended from a
screw-hook.

Finally, by excising one or more pieces of the wall with a keen
scalpel, the position and shape of the orifices may be displayed.

A. Dried inflated specimens should be kept free from dust and moisture, in close cases,
or boxes or jars. They should not be varnished.

B. Inflated preparations which have been dried without poisoning, or have been insuf-
ficiently poisoned, may be sprayed with the solution of arseniate of soda by means of an
atomizer. This should be done cautiously and over a small area at a time, lest the entire
organ collapse.

C. According to a paragraph in the “ American Naturalist ” for March, 1881, page 282,
“‘Dry specimens may be freed from parasites by spraying with anhydrous sulphurous acid.”

§ 334. To measure the Capacity of an Organ.—This may be
done in either of two ways :—

1. The organ may be filled with water from a vessel of known
capacity, and the amount measured.

2. The organ may be filled, and its contents allowed to escape
into a vessel and then measured.

In employing either method, certain precautions should be ob-
served :—

1. The organ should be completely emptied of its contents.

2. It should not be measured until after the cessation of any
contraction which may exist at or soon after death.

3. If possible, it should be held by an assistant.

4, It should rest in a dish of water so that the water used in
measuring may not exert undue pressure.

5. Since only the capacity of the organ itself is desired, care
must be taken to let the water go no farther than the outlets. With
the stomach, for example, the pylorus should be closed, and the
introduced water should not rise into the cesophagus.

6. If the organ is not to be preserved, the pylorus may be tied.
But as tying injures the parts, a specimen which is to be preserved
may have the outlet held by an assistant or closed by a compressor
or by other mechanical means.

7. If the cardiac orifice is large, the water may be poured in.
If small, it may be introduced through a tunnel or through a can-
ula connected with a syringe. In the one case hydrostatic pressure

136 ANATOMICAL TECHNOLOGY.

must be avoided, and in the other no more force should be used
than will suffice to propel the water very gently.

8. If the contained water is to be measured, the organ should be
brought to the edge of the vessel, and the latter filled so that the
outlet of the organ may be carried over its edge. Then the contents
are to be carefully expressed into another vessel. In no case must
the organ be made to support the weight of the contained water.

9. While full, the organ should be measured as to length, width
and height, and as to its girth at one or more points.

§ 335. To measure the Volume of an Organ.—The following
method is proposed by Dr. H. P. Bowditch (7, 149): “ Plunge the
organ into a vessel already full, and measure the overflow.”

Of course the full vessel must stand in a dish from which the
overflow may be collected, and the ordinary anatomical tray will
not answer. In some cases, therefore, the following method, though
less simple, may be more easily adopted, and the result will be
almost equally exact :—

Attach a cord securely to some part of the organ. Place it ina

vessel, and fill the latter with water. Then remove the organ by

means of the cord, and the amount required to fill the vessel will
represent the volume of the organ. In most cases, the space occu-
pied by the cord may be disregarded.

General References to the Preservation of Soft Parts.—The following are in addi-
tion to the references given on p. 111:—U. 8S. Dispensatory, 13th ed., Art. Alcohol ;
Watts, A; Baley, A; Giinther, A, Appendix; Keen, 7, 2; Dwight, A, B, and J;
Reeves, A; Highley, 2; Hyrtl, A; Mojsisovics, A, 26-87.

CHAPTER IV. .
COARSE INJECTIONS.

§ 336. SpEcIAL APPARATUS AND MATeERtAL :—Acid, Acetic, No. 8, mixed with an
equal volume of water—Aniline Red (Magenta)—-Aniline Blue—Beeswax—Berlin Blue
(see § 1449)—Carmine No. 40—Chrome Yellow—Chrome Green—Cobalt Blue—Dishes
(2) of 100 cc. capacity—Magenta or Aniline Red—Mixing Dish, 400 cc. capacity—Pestle of
Wood or Porcelain—Pins—Plaster of Paris, Finest Dental—Red Lead—Sponge—Syringe
with assorted Canule—Thread, Linen No. 25-35, Cotton No, 20—Turpentine, Oil of—
Varnish, Copal—Vermilion, American or Chinese.

§ 337. The object of injections is to render the blood vessels
more apparent, and thus to facilitate their detection. The impor-
tance of a perfect familiarity with their position and relations cannot
be overestimated from the surgical and experimental standpoints.

§ 838. Syringe.—A syringe is usually employed to force the injecting mass into the
blood vessels. It should have the following features :—(A) Ample capacity, so that one
syringe full will fill the entire arterial or venous system of the animal to be injected. Of
course this does not apply to large animals like horses. One of 200 cc. is adapted to cats.
(B) The piston of the syringe should fit well and be leather packed (Fig. 35). (C) There
should be canulz of various sizes corresponding to the different vessels to be injected.
The brass anatomical syringes (Fig. 37, 38) are best, but quite expensive.

Care of the Syringe.—As soon as an injection is finished, expel any remaining
plaster into the waste pail. Then fill the syringe several times with clean water and
expel it. Force a part of a syringe full through the canula, so it may be entirely emptied.
Finally, it is best to unscrew the top of the barrel and remove the piston, so that the bar-
rel may be entirely emptied. Wipe the piston with an old towel and oil the leather
packing before returning the piston to the barrel.

If glue or wax mass is employed, the syringe should be cleaned with hot water.

If the piston becomes so loose that the mass passes it instead of being forced out
through the canula, remove the piston, and make the leather packing flare slightly (Fig. 35).

If the canula becomes clogged, it may be easily opened by using a small knitting
needle.

§ 339. White-Metal Syringe (Fig. 35)—Syringes of this kind are cheap and answer
very well for both coarse and fine injections. The metal canula is much too large to insert
in an ordinary vessel, but that difficulty may be easily overcome by the use of glass can-
ule (Fig. 36) and a rubber tube for connection (Fig. 42).

138 ANATOMICAL TECHNOLOGY.

Barrel.—The barrel of the syringe is the large cylindrical part in which the piston fits.
The injecting mass is drawn into it by pulling the piston in the direction of the handle.

packed piston.

Fic. 35.—WHITE-METAL SYRINGE WITH ToP UNSCREWED AND PIsToN
REMOVED; x.3.

Canula.—The canula is the smaller part which serves to connect the syringe with the
object to be injected.
Handle.—The handle is a continuation of the piston. It projects from the barrel, and
by it the piston is moved.
Piston.—The piston of a syringe is within the barrel. Its end should be packed with
leather, as shown in the figure, so that it will fit very closely.
Canula or Nozzle.—The canula serves to

connect the syringe with the object to be in-
jected. The end should be cut off obliquely.

) It is then like a wedge, and may be inserted
into the vessel much more easily than one
cut squarely off.

—
A B
The caliber of the canula should be as
ae ee () great as can be put into the vessel to be in-
c jected. For plaster injections (§ 341) the
Fie. 36.—CANULZ; x.6. canula should not be less than 1 mm. at its
narrowest point. :
A.—Metal canula with lateral arms at the end next the syringe, and a slight shoulder
at the smal] end.
B.—A glass canula cut off obliquely at its small end.
C.—A glass tube drawn out for two canule.

§ 340. To prepare glass canule, take a glass tube about 6 mm.
in diameter and from 8-10 cm. in length, and heat its middle evenly
in a Bunsen flame. When the glass is softened, draw the two ends
apart until the tube is sufficiently reduced in caliber in the middle ;
then after cooling make a fine scratch with a file as shown in C, and
the two may be broken apart. When separated, grind the end first
on a fine file with water to make it oblique as in A and B, and
finally on the fine oil stone to make it smooth. Heat the larger end
in the flame to round the sharp edges.

INJECTION MASSES. 139

In this figure (Fig. 87) of the regular brass anatomical! syringe, are shown four canule
of various sizes and a separable stop-cock. The stop-cock fits upon the end of the short

I: =
CODMAN & SHURTLEFF,
BOSTON.

Fie. 37.—BRaAss SYRINGE; x .5

canula of the syringe, and the canul for insertion in the vessels fit upon the end of the
stop-cock, In most syringes of this kind the stop-cock may be dispensed with and the
canule fitted directly to the syringe if desired.

: INJECTION MASSES.

§ 341. Plaster of Paris Mass.—The most convenient mass is
composed of the finest plaster of Paris stained with carmine solu-
tion for arteries and with Berlin
blue for veins. To facilitate the
preparation of the mass, a quan-
tity of both colors should be kept
in stock.

§ 342. Carmine Solution.—

This is prepare d by grinding to a are Brass SYRINGE WITH
- EMOVABLE STOP-COCK AND CANULA

paste 4-5 grams of carmine No. vor Fosm Insncrions; x 3.

40 in 20 ec. of water and then

dissolving it in 50 ce. of strong ammonia. To this solution is then

added 75 ce. of glycerin and 500 cc. of water. After shaking well,

filter through fine flannel or absorbent cotton.

§ 343. Blue.—Berlin blue (§ 1449), a saturated aqueous solution,
500 cc., glycerin, 75 ce. Mix the glycerin and the blue, and filter
as for red. The glycerin preserves the solutions and retards the
setting of the plaster (Gage, 1, 717).

-§ 344. Various Colors—A. fed.—Plaster mass may be well
colored by American or Chinese vermilion, red lead or a solution of
aniline red (magenta): Magenta, 2.5 grams; 50 per cent. alcohol,
100 cc.

140 ANATOMICAL TECHNOLOGY.

B. Blue—The plaster mass may be colored blue by cobalt or
ultramarine blue or a solution of aniline blue: Aniline blue, 2.5
grams ; 50 per cent. alcohol, 100 ce.

C. Yellow or Green.—Employ chrome yellow or green.

Permanent preparations should not be made of an animal in-
jected with a mass colored by one of the aniline dyes, for they are
soluble in alcohol and fade in the light. The vermilion and cobalt
blue are the most permanent, but the carmine and Berlin blue last
many years.

§ 345. Preparation of Plaster Injection Masses.—The masses
should be used immediately after preparation, and before the plaster
has time to set.

Approximately the same volume of plaster and liquid should be
employed for ordinary injections. If, however, one wishes the mass
to fill the smallest vessels, the liquid should be increased so that
the ratio is as 1-2 or even 1-3. 3

A. Mass Colored with Carmine.—Measure out 100 cc. of the
finest plaster of Paris and put it into a mixing dish, a tea or coffee
cup, that will hold about 400 cc. Add to this plaster about 100 cc.
of the carmine solution (§ 343), and mix thoroughly with a wooden
or porcelain pestle. Finally, add slowly and with constant stirring
the 50 per cent. acetic acid. Add the acid till the color changes to
bright red and the odor of the acid in the mass is quite perceptible.
An excess of acid is less injurious than a deficiency.

B. Mass Colored with Berlin Blue.—Plaster same as for car-
mine. Add 100 cc. of the Berlin blue solution (§ 348), and stir well.
No acid is necessary.

C. Masses Stained with Aniline.—Measure out 100 ec. of plas-
ter and put it into the mixing dish as directed above; then add, for
red, 20 cc. of the magenta solution and 100 cc. of the 15 per cent.
glycerin solution (§ 171). Stir thoroughly. For blue, add 50 ce. of
the blue aniline solution and 75 cc. of the 15 per cent. glycerin.

D. Mass Colored with Vermilion or Red Lead.—Put 25 grams
of the dry color into the mixing dish and add 25 ce. of 15 per cent.
glycerin. Grind the color thoroughly to crush all the lumps.
Finally, add 100 cc. of plaster and 100 ec. of 15 per cent. glycerin,
and mix very thoroughly.

E. Masses Colored with Cobalt or Ultramarine Blue, Chrome
Yellow or Green.—Employ 15 cc. of the color, and prepare as
directed for the vermilion (§ 344).

WAX AND TALLOW INJECTIONS. 141

§ 346. Wax and Tallow Masses.— Wax Mass.—Beeswax, 2
parts ; Canada balsam, 2 parts; Vermilion, 2 parts.

Mix the wax and Canada balsam and melt over a water bath.
Then grind the vermilion thoroughly in a small amount of mastic
varnish, and add it to the mixture. Heat over the water bath for
half an hour or more. This mass flows very finely. Hyrtl, A, 616.

Tallow Mass.—Tallow, 900 grams; Magnesia usta (calcined
magnesia), 15 grams; Vermilion, 30 grams.

Grind the magnesia and vermilion in a small amount of mastic
varnish or turpentine, before adding to the melted tallow. Harri-
son, A, IT., 866.

§ 347. Practical Working of Wax and Tallow Injections.—
First. The animal must be warmed to 38-40° C. This is best done
in a large galvanized iron dish that may be covered and the
water kept hot by means of a Bunsen burner or in some other
way. All the heating should be done in a water bath so that no
burning may occur.

When the animal is warmed through (the time required de-
pends on the size of the animal), the canula should be put in posi-
tion (§ 358). Warm the syringe thoroughly by filling it with hot
water and slowly emptying it. Warm the mass till it is quite
fluid, and stir it well. If itis not heated above 50° C., it will not
burn most mammalian tissues. Fill the syringe with the mass and
force it out, to make sure the mass is thoroughly mixed. Then fill
the syringe, connect it with the canula in the vessel, and force the
mass in rather more rapidly than directed for plaster (§ 359), but
the operation should not be so long continued.

One cannot inject Fishes or Amphibia with wax mass, as Hyrtl has well said, for the
heat required to warm the subject and the mass would cook the tissues. For them, plaster
or some other cold flowing mass, or glue which remains liquid at,a low temperature, must
be used.

After the injection is finished, the animal should remain in a
cool place for at least three or four hours before the dissection is
commenced.

§ 348. Choice of Specimen for Injection.—A young adult and
lean cat is best. It should be fasting except for special purposes.

§ 349. Time of Injection.—Inject before the vigor mortis comes
on. If that is impossible, it is better to put it into warm water —
(35° C.) for an hour to make the muscles flexible. This is not abso-

142 ANATOMICAL TECHNOLOGY.

lutely necessary, but the smaller vessels will be more likely to be
injected if the muscles are flexible.

§ 350. Arteries to Inject for a Complete Injection of the Ani-
mal, named in order of Desirability : A. femoralis, A. carotidea,
Aorta (Fig. 39, 101).

Fie. 39.—FEMORAL VESSELS; x.5.

§ 351. Veins to Inject: V. femoralis, V. jugularis externa,
Postcava (Fig. 101). As to Cleanliness, see § 199.

INJECTION OF THE FEMORAL VESSELS.

§ 352. Posture.—Place the cat dorsicumbent, as in Fig. 76.
§ 353. Exposure.—Grasp the meros close to the trunk with the
pollex and index, and the,femur will be felt in an interval between

DISSECTION. 143

the muscles on the cephalic side (upper side in the present posture).
The femoral vessels are just entad of the skin and connective tissue,
and parallel with the femur in the proximal third of the meros.
To expose the vessels, lift a triangular flap of skin (Fig. 39).

§ 354, Parting the Hair.—Before making the incisions, wet the
hair well with a sponge, and with a comb part it along the lines
where the incisions are to be made. Incisions can be very much
more neatly and easily made after the skin is thus exposed.

Fic. 39.—Preparation.—The arteries were injected caudad from the aorta abdominalis
($ 101); then the veins were injected from the V. poplitza in the popliteal space, in the
concavity of the knee (Fig 30). After half an hour the triangular flap of skin was dis-
sected free and turned to the left and secured by a pin passing through its tip into the
muscles of the left meros. All the fat and connective tissue were then removed with the
tracer, fine forceps and scissors.

A. (Arteria) femoralis—Femoral artery.—This is the continuation of the A. iliaca
externa (§ 101). It is between the vein and nerve.

Ann. abd. ext. Annulus abdominalis exterior s. ectalis—External (ectal) ingui-
nal ring.—This is the ectal opening of the inguinal canal through which the chorda sper-
matica passes into the abdominal cavity.

C. sp. Chorda spermatica—Spermatic cord.—This is a bundle of structures passing
from the testis to the abdominal cavity. It is composed mainly of the spermatic artery
and vein and the vas deferens.

Lg. P. Ligamentum Poupartii (Poupart’s ligament, Crural arch).—This is a liga-
mentous or aponeurotic arch dorsad of which pass the femoral vessels.

N. (Nervus) cruralis anterior (Anterior crural nerve).—This is the largest branch
of the lumbar plexus of nerves. It is both muscular and cutaneous in distribution.
Quain, A, I, 604.

Scarpa’s Triangle.—This is the triangular depression on the cephalic side of the
meros in which the femoral vessels are found. Quain, A, I, 454; Gray, A, 546.

V. (Vena) femoralis—Femoral vein.—The femoral vein is continued by the V. iliaca
communis as it passes into the abdomen. It is caudad of the artery as the two pass dorsad
of the Ligamentum Poupartii, but ventrad of it in the meros.

§ 355. Dissection.—With the tracer and fine forceps, very care-
fully dissect the artery free from the vein, nerve and connective tis-
sue for about 2 cm. from the abdominal wall. Be very careful not
to. stretch the artery. It seems only about half as thick as the
vein.

§ 356. Incisions in the Vessel.—When the artery is free, put
the handle of a scalpel wet in 15 per cent. glycerin entad of it (Fig.
40); with a Charriére scalpel then make a V-shaped incision that
will include about one third the width of the vessel as it is flattened
on the scalpel handle. Cut entirely through to the scalpel handle
on which the vessel rests. The Charriére should be held pen-like
(Fig. 63), and so that the apex of the V (Fig. 40) shall point periph-

144 ANATOMICAL TECHNOLOGY.

erad. A more convenient, but less safe way for beginners, is to
employ scissors as shown in Fig. 40. It is
sometimes desirable also to cut the V from
apex to base as shown in Fig. 42. Enlarge
the opening in the vessel by inserting the
probe wet with 15 per cent. glycerin.

§ 357. Ligatures.—While the probe is
still in the vessel, with the fine forceps
grasp the middle of a thread 30-40 cm.
. long and push the loop through entad of
the vessel, and at a point centrad of the
incision (Fig. 40). The loop may then be
grasped by the fingers or forceps and
drawn through as far as desired.

Instead of pushing the thread through
as directed above, one may put the forceps
entad of the vessel first and grasp the loop
: and pull it through. Bernard, A, 263.

Fic. 40.— INCISIONS AND PREP- When the thread is through as far as
Cok ee MIGATURING; desired, cut the loop. The thread nearest

2 the incision is for tying the canula in the
vessel ; the other is for ligaturing the ves-
sel when the injection is finished. Both
threads should be loosely tied in a swr-
geon’s knot (Fig. 41), so that they may
be quickly tightened. .

§ 358. Introduction of the Canula.—
When the threads are prepared, remove
the probe from the vessel, select a canula
of the proper size, that is, as large as can
be put into the vessel, and make sure that
it is open by blowing into it or forcing
water through it with the syringe. Hav-
ing wet its small end, put it into the ves-
sel so that the injection will be centrad.
To insert the canula, grasp one edge of

Fie. 41.—DousBLE LIGATURE ;

the V-shaped incision with the fine for- se:

ceps and pull it open. Now introduce

the canula and push gently with a slight twisting motion. At the
same time pull with an equal force in the opposite direction with the

‘

MAKING THE INJECTION. 145

fine forceps by which the edge of the incision is grasped. As soon
as the canula is in the vessel, let go the edge of the slit and grasp
the whole vessel where it sheaths the canula. Pinch quite firmly,
and pull while the canula is pushed into the vessel for about 1 cm.
The canula being smooth slips into the vessel notwithstanding the
pressure of the forceps. Rest the elbows on the table to steady
the hands.

The canula should be very smooth, and the serrations on the for-
ceps must not be too deep or they will cut the vessel. The canula
may be polished as directed for instruments
(§ 183), and any roughness may be removed Vessel,
by the oil stone. a:

As soon as the canula is properly in-
serted, put the thread nearest the incision
(Fig. 40) so that it will press on the canula
within the vessel, and then tighten the knot.
If the canula has an enlargement near the
end (Fig. 36, A), it cannot escape when tied as
in Fig. 42. If there is no enlargement or a
glass canula is used, the thread must be tied
to some part of the canula outside the vessel.
If there are transverse projections (Fig. 36,
A), the thread should be tied around one of
them. Ifa glass canula is used, tie as shown
in Fig. 42. All the threads should be knot-
ted in a hard knot finally, and the ends
should be cut within a centimeter of the last
knot.

§ 359. Making the Injection.—As soon 5,4 49 Ixsermne AND
as the canula is secured in the vessel, fill the — smcurrne Canuna; x5.
syringe partly with water or normal salt solu-
tion, connect it with the canula in the vessel, and force a little of
the liquid‘in to make sure the canula is open and properly inserted.
In connecting the canula and syringe, grasp the canula with one
hand and hold it firmly while making the connection. Do the same
in separating them.

After forcing a small amount of water into the vessel, separate
the canula and syringe, expel the water, and then prepare the mass
as directed above (§ 345). Stir the mass thoroughly, and then fill

the syringe, being sure to lower the syringe as the mass is drawn
10

146 ANATOMICAL TECHNOLOGY.

into it, so that no air may get into the syringe. Connect the syr-
inge with the canula which is in the vessel (§ 358). Hold the canula
firmly with one hand and pull toward the syringe as the mass is
forced into the vessel. Be sure that the vessel is not looped or
twisted in the least, but drawn peripherad just enough to straighten
it. Force the piston down steadily and continuously ; do not allow
it to stop until the injection is finished. If the canula becomes
clogged, the resistance will be complete, and there will be an
entire absence of the elastic feeling which comes from the distended
arteries. Very often the canula may be opened by pulling the pis-
ton back a little and then forcing it down quickly.

One can tell only by experience when the injection is finished.
The vessels are usually filled, however, when the piston returns
slightly on remitting the pressure. If the injection is carried too
far or the pressure is too great, the semilunar valves (Fig. 102) are
liable to be ruptured and the heart filled, or some vessel may give
way.
§ 360. Tying the Vessel.—As soon as the injection is finished,
tie the vessel with the thread provided for the purpose (Fig. 42),
draw back the piston slightly, and then cut the string holding the
canula in the vessel and remove the canula.

§ 361. Cleaning the Canula, Syringe and Mixing Dish.—Do
this immediately after the injection is finished before the plaster has
time to set. Expel the plaster remaining in the syringe into the
waste pail; then fill the syringe with water and empty it. Do this
several times, and then force some clean water through the canula.
Finally, it is best to unscrew the top of the syringe and pour out
any liquid that has passed the piston.

Throw any plaster remaining in the mixing dish into the waste
pail and clean out the dish very thoroughly. The plaster must not
be thrown into the sink lest it should set and clog the waste pipe.
The dissection may commence in half an hour after the injection is
finished.

§ 362. Injection of the Femoral Vein—Fig. 39.—Dissect the
vein free for 2 or 3 cm. from the abdominal wall as described for
the artery (§ 353). Compress the vein and force the blood centrad.
It will pass very readily and leave the vein nearly empty. Now
press on the vein just as it enters the abdomen and try to force the
blood peripherad. There will be seen a bulging in the vessel ex-
tending about .5 cm. from the body wall. There are two valves at

INJECTION OF THE VARIOUS VESSELS. 147

the peripheral end of the enlargement which prevent the flow of
blood in this direction. Make a V-shaped incision in the vein cen-
trad of the valves in the same manner as directed for the artery
(§ 856). Compress the thorax and hold the cat upright to facilitate
the flow of blood.

When as much blood as possible is removed, insert the canula
(Fig. 42), and inject plaster prepared as directed (§ 359).

The injection should be made as directed for the arteries, but it
should be remembered that the walls of the veins are thinner than
those of the arteries, and hence the pressure must be more moderate.

On account of the valves in the systemic veins (Fig. 102), it is necessary to inject cen- —
trad. The injection may be made to pass the valves sometimes, however, by manipulating
the part while the mass is forced in.

§ 363. Injection of the Aorta Abdominalis.—Posture and
Exposure.—Place the cat dorsicumbent, and then expose the ab-
dominal viscera as shown in Fig. 79, and directed hereafter.

Turn the four flaps aside, and then turn the intestines to the left.
The right kidney will be seen on the right side, and in the middle
line the postcava (Fig. 101).

§ 364. Dissection, and Insertion of Canula.—With the tracer
tear away the mesentery (Fig. 80) and connective tissue in the middle
line opposite the caudal margin of the right kidney. The aorta is
dorsad and sinistrad of the postcava in this region, and between
the two great psoas muscles. Freeitfor 23cm. Makea V-shaped
incision with scissors (Fig. 40), insert and fasten the canula, and
inject as directed above (§ 359).

If only the cephalic part of the body is to be studied, it is necessary to inject cephalad
only, but if the entire animal is to be studied, one should inject first cephalad and then
caudad. ‘The second injection should be made as soon as possible after the first,

As soon as the injection is made, the postcava should be opened to allow the blood to
escape.

§ 365. Injection of the Postcava.—The exposure is the same as
for the Aorta abdominalis. Inject as directed for the V. femoralis
(§ 362).

§ 366. Injection of the V. Jugularis Externa.— Posture.—Place
the cat dorsicumbent and a block flatwise under the neck and
shoulders. Rotate the head so that the nose points away from the
side to be injected.

Exposure.—Press upon the throat and find the larynx (Fig. 30,

148 ANATOMICAL TECHNOLOGY.

§ 224). Then press upon the side of the neck near the head and de-
termine the position of the wing of the atlas, diapophysis atlantalis
(Fig. 52, § 229). Part the hairalong a caudo-cephalic line from about
midway between the wing of the atlas and the larynx, and then
commencing opposite the cephalic edge of the wing of the atlas,
carry an incision directly caudad for 3-5 cm. Divaricate the skin,
and the external jugular vein will appear, full of blood.

Injection.—Dissect the vein free as directed for the A. femoralis,
make a V-shaped incision, insert the canula, and then remove as
much blood as possible, as directed (§ 362). Finally, inject with
_ blue plaster (§ 348).

It is impossible to fill the small vessels with plaster on account of the valves (Fig. 102).
If one wishes to inject the venous system of the cat, it may be done successfully in most
cases by injecting blue gelatin into the jugular or femoral vein. See Appendix, § 1450.

§ 367. Injection of the Arteria Carotidea.— Posture.—tThe pos-
ture should be the same as for the V. jugularis externa (§ 366).

Exposure.—Make an incision through the skin as directed for
the external jugular vein (§ 366). Dissect up the mesal edge of the
skin to the ventrimeson. Determine the position of the larynx, and
then make an incision 2-3 cm. long just laterad of the larynx and
through the sterno-mastoid muscle. -Divaricate the cut edges of the
muscle, and there will be seen extending parallel with the trachea
the carotid artery, the vagus and sympathic nerves, and the V.
jugularis interna (Fig. 101).

Dissection —_W ith the tracer and forceps, dissect the artery free
from the nerve and vein. Make a V-shaped incision, insert the
canula, and inject centrad as directed for the A. femoralis (§ 359).

All the arteries of the body will be filled excepting those cephalad of the place of
injection on the side injected. To fill those, one must inject cephalad after the general
injection is made,

References to Coarse Injections.—Bernard, A, 191, 262; Gage, 1,717; Harrison,
A, II, 865 ; Heath, A, 547; Hyrtl, A, 615; Straus-Durckheim, B, I, 90; Mojsisovics, A,
15-24,

.

CHAPTER V.
OSTEOLOGY—THE STUDY OF THE BONES.

THE DETERMINATION OF THE RIGHT AND LEFT WITH CERTAIN BONES—SPECIAL’ MNE-
MONICS OF THE HUMERUS—DETALIED DESCRIPTION OF THE SCAPULA, HUMERUS,
CARPALIA, CLAVICULA, STERNUM, COSTA, PELVIS, VERTEBRA AND SKULL.

§ 368. A general description of the whole skeleton has been
given on pp. 87-95. In accordance with the general plan of this work
as stated in § 128, certain parts of the skeleton are also described
somewhat in detail, while others are mentioned only incidentally or
not at all.

Sooner or later, of course, the student will consult some complete
treatise upon Human, Veterinary or Comparative Anatomy, and thus
acquire the information here omitted. We believe, however, that
he will do well to make for himself drawings and descriptions of the
bones not fully described here; the drawings should be in outline
or but slightly shaded; the descriptions should be in two parts,
general and brief, and special and detailed.

DETERMINATION OF RIGHT AND LEFT.

§ 369. The right and left of paired bones may be determined
by reference to a mounted skeleton or figure. The longer membral
bones and the parts of the shoulder and pelvic girdles may also be
distinguished by means of the following special formule :—

In all cases, except with the scapula, innominatum and fibula,
the Zong axis of the given bone is placed horizontally from the left
to the right of the observer, and the distal end is made to point to
the side to which the given bone belongs. |

At the end of the formula for determining the side of the body
to which a long bone belongs, are placed directions for the recogni-
tion of one of the extremities and two of the sides or aspects which
are not opposite. The end and the sides not given may then be
readily ascertained. Finally, there are directions for determining

150 ANATOMICAL TECHNOLOGY.

the aspects of the limbs as wholes, together with some special mne-
monics for the humerus.

§ 370. Clavicula—Clavicle, collar bone (Fig. 48).—A. Man.—
It should be placed with the greater concavity up, the projecting
part of the thick, mesal or sternal end toward the observer; then
the flattened lateral end will point to the side to which the bone
belongs.

B. Cat.—It should be held with the subcylindrical end mesad
and curving downward, the great concavity toward the observer ;
the flattened end will then point to the side to which the bone be-
longs. In young cats the two ends are so nearly alike that it is
difficult to determine right and left.

§ 371. Scapula—Shoulder blade (Fig. 43-45).—The gleno-ver-
tebral angle (§ 383) should be held toward the observer and the
glenoid fossa down; then the mesoscapula will be on the side to
which the bone belongs.

§ 372. Humerus—(Fig. 46).—The bone should be held with the .

olecranon fossa (Fig. 71) up, the epitrochlea toward the observer
(the musculo-spiral groove in man away from him). In the cat and
many other animals, rarely in man also, there is a foramen (/’m.
epitrochleare, Fig. 46), near the caudal border of the distal end
(§ 417).

The olecranon fossa, the deepest of the distal fosse (Fig. 71) is
on the dorsal aspect. The Foramen epitrochleare in the cat and the
most prominent apophysis (epitrochlea) of the distal end are on the
caudal side in both cat and man.

§ 373. Radius—(Fig. 30).—The bicipital tuberosity should be
held down, the styloid process on the side away from the observer.
The styloid process is the most distal part of the bone. It is on the
cephalic side, while the bicipital tuberosity, which is near the prox-
imal end, is mostly on the ventral side. The distal end is the larger.

§ 374. Ulna—(Fig. 30).—The great sigmoid cavity should be
held down, the lesser sigmoid cavity from the observer; then the
smaller end points to the side.

The great sigmoid cavity is on the ventral aspect at the proximal
end; the lesser one is on the cephalic aspect just distad of the
greater one and continuous with it.

§ 375. Innominatum—Pelvic bone (Fig. 30, 51).—It should be
held with the ischiatic tuberosity toward the observer, the pubic

DETERMINATION OF RIGHT AND LEFT. 161

arthral facet down, the cotyloid fossa looking to one side; the fossa
will be on the side to which the bone belongs.

§ 376. Femur—(Fig. 30).—The bone should be placed with the
head pointing away from the observer, the intercondylar fossa or
notch down.

The nearly spherical arthral head is situated at the proximal
extremity ; it faces approximately cephalad. The longitudinal con-
cavity of the whole bone and the intercondylar fossa or notch are
on the ventral aspect.

§ 377. Tibia—(Fig. 30)—It should be held with the tuberosity
for the patellar ligament up, the malleolus facing away from the ob-
server ; the end bearing the malleolus will point to the side to
which the bone belongs.

The most distal part (malleolus) is on the cephalic, and the lon-
gitudinal concavity on the ventral aspect.

§ 378. Fibula—(Fig. 30).—If the bone be placed horizontally,
with its distal extremity toward the observer, and the distal arthral
surface up, then the deep rough depression at the latero-distal mar-
gin of the arthral surface will be on the side to which the bone be-
longs ; or, in grasping this end with the pollex and index, the pollex
of the side to which the bone belongs may be easily put into this
depression.

This method, so far as we know, was first devised by G. S. Shep-
pard, a student in the anatomical laboratory of Cornell University.

The distal arthral surface is on the cephalic aspect, and the
depression for the ligament spoken of below is at the ventro-distal
edge of this surface.

The arthral surface of the distal extremity is on the side, while
that of the proximal extremity is nearly on the end. The depres-
sion spoken of at the distal end is for the attachment of the ‘‘ pos-
terior fasciculus of the external lateral ligament” of the ankle.

§ 379. Determination of the Right and Left with the Entire
Limbs.—The sides of the whole arm may be recognized by remem-
bering that the capitellum, radius and pollex (thumb) are on the
cephalic side, while the olecranon process and fossa are on the
dorsal side, and the convexity of the elbow points dorsad.

The sides of the whole leg may be determined, since the tibia and
primus (great toe) are on the cephalic aspect, and the convexity of
the knee faces dorsad.

152 ANATOMICAL TECHNOLOGY.

§ 380. Special Mnemonics of the Humerus.—With a bone
having such numerous and important anatomical relations, so vari-
ously placed in different animals and in the same animal at differ-
ent times, so frequently involved in surgery, and so generally rep-
resented in painting and statuary, it is very desirable that the names
and relative positions of the parts should be promptly remembered.
The following mnemonic suggestions may prove useful to some :—

Of the two ends of the bone, proximal and distal, the former is
the larger and has the longer name. .

The cephalic side is also called radial, and both these names are
longer than the corresponding words caudal and ulnar, which
apply to the opposite side.

With one exception, the principal features of the cephalic side
have longer names than the similar parts upon the caudal side.
Trochiter, capitellum and F's. radialis are longer than trochin,
trochlea and F's. ulnaris. The trochiter itself also is larger than
the trochin.

Epicondylus equals epitrochlea in length, but the latter is read-
ily associated with ¢rochlea, and itself suggests the name of the #’m.
epitrochleare.

In the normal position of the arm, the deep olecranon fossa
(Fig. 71) is uppermost with both man and cat. With the cat also,
the longer and more decided dorsal concavity of the bone as a
whole may be, though somewhat remotely, associated with the back
of a saddle horse.

§ 381. The selected portions of the skeleton are here described
in the following order, which is mainly that of their simplicity :-—

Scapula, humerus, ulna, radius, carpus, clavicula, sternum,
coste (ribs), pelvis, vertebree, and skull. The other membral bones
and the Os hyoides have been briefly described in §§ 220-224.

THE SCAPULA (Fig. 30, 43, 44, 45, 67, 74, 75).

References,—Straus-Durckheim, A, I, 507-509; Parker, A, 215, Pl. xxx. ; Owen, A,
II, 488; Gray, A, 218-223; Quain, A, I, 81; Chauveau, A, 81; Chauveau (Fleming), A,
72 ; Flower, A, 221 and 229 ; Humphrey, A, 363-370 ; Mivart, B, 89-91 ; Leyh, A, 170, 171.

§ 382. General Description. —The scapula (shoulder blade or
blade bone) is a flat irregular bone imbedded in the muscles on the
lateral aspect of the cephalic region of the thorax (Fig. 30, 67, 74,
75), and articulating with the humerus to form the shoulder joint.

As seen from its ental or ectal aspect (Fig. 43 and 44), the out-

THE MARGINS AND ANGLES OF THE SCAPULA. 153

line of the scapula may be characterized as either subtriangular or
approximately semicircular. The former term is more commonly
employed, perhaps because it is more applicable to the human
scapula. But if the two scapule of the cat are placed with their
straighter sides in apposition, they will be seen to cover an area
which is approximately circular, although the borders are more or
less undulating.

§ 383. The Margins and Angles of the Scapula—tt is at least
convenient to regard the scapula as triangular, and as presenting
therefore three sides (margines) and three angles (anguli).

The thicker (glenoid or arthral) angle articulates with the hu-
merus, and presents several elevations and depressions which will
be described separately. Its larger part is occupied by a concave
surface, the Hossa glenoidea, for articulation with the humerus;
hence that border of the bone which is separated from the fossa only
by its lip is called the Margo glenoideus. Between the fossa and
the other border springs a hook-shaped projection, the Pre. cora-
coideus, and the border is thence named Mrg. coracoideus. The
intermediate border is called the Mrg. vertebralis from its proxim-
ity to the Columna vertebralis.

Of the borders, the glenoid is the longest and straightest. The
coracoid is the shortest and least regular, and its outline varies in
different individuals. According to the observations of Parker (A,
215, Pl. xxx., Fig. 1-3), in the cat and in some other Carnivora this
margin ossifies from an independent center and remains for some
time separate from the rest of the bone. The vertebral border is
intermediate in length, and presents a nearly regular curvature.
With young individuals this margin is cartilaginous, representing a
suprascapula, but later it becomes codssified with the rest.

The angles, respectively more and less obtuse, formed by the
junction of the vertebral margin with the other two, are called coraco-
vertebral and gleno-vertebral.

The emargination of the coracoid border near the neck of the
bone (at the lower end of the dotted space in Fig. 43) is known as
the Incisura coraco-scapularis (Flower, A, 223). In the human
scapula it is deeper and commonly called the suprascapular notch.

§ 384. Description of Fig. 43.—The ental aspect of an adult left scapula.

Acromion.—This is more distinctly seen in Fig. 44 and 45.

§ 885. Arew Musculares— Areas of the attachment of muscles.—Upon these two fig-
ures of the scapula and upon four views of the humerus (Fig. 68-71), the areas of muscular

154 ANATOMICAL TECHNOLOGY.

attachment are enclosed by interrupted lines. Following the method of Gray (A) and
H. 8. Williams (1), the origins are indicated by dots and the insertions by short lines. It is
easy to associate these two marks with the letters 0 and i, which form respectively the

initials of origin and insertion.
The scapula affords origin to the following 10 muscles : Subscapularis, supraspinatus,
infraspinatus, meditriceps, spino-deitoideus, acromio-deltoideus, teres (major), micostalis
(teres minor), biceps and cora-

Fe ae coideus. Upon it are inserted
ov’ es

ig Sey tt the following 7 muscles:

es ; Acromio-trapezius, spino-tra-

pezius, rhon.boideus, serratus,
scence esses ee levator anguli scapule, levator
clavicule and occipito-scapu-
taris. On the figure the in-
sertion area of the last named
aN in muscle is represented as too
A \ Ss near the coraco-vertebral an-
Q ‘e gle.
\ >. § 386. Collum — Neck. —
‘\ © This is the thickened and _
slightly constricted portion of
; the scapula conneciing the
- gilenoid end or angle with the
* body of the bone. According
to Quain (A, II, 83), its limits
are differently assigned by
anatomists and surgeons,

§ 387. Foramen Nutriens—
The vascular foramen,—There
may be 1, 2 or 3 of these fora-
mina upon the ental aspect,

Fig, 43.—THE ENTAL ASPECT OF AN ADULT LEFT and their location is quite

ScapuLa; x1. variable. They always enter

obliquely so as to point toward

the glenoid end of the bone, and at least one of them is traceable to the base of the
mesoscapula.

Fossa Glenoidea.—See description of Fig. 45, § 399.

§ 388. Fossa Subseapularis.—This name is applied to the entire ental surface of the
bore; as shown upon the figure, however, the muscle of the same name does not arise
from the whole area. Most of the margin of the fossa is more or less raised. The shaded
area represents a shallow longitudinal furrow which coincides nearly with the mesoscap-
ula (Fig. 44).

Between the furrow and the coracoid margin are two well marked ridges for the attach-
ment of tendinous intersections of the M. subscapularis ; there are usually other ridges
which are most distinct in old individuals. Near the glenoid margin is a prominent ridge
which separates the Fs. subscapularis proper from the shallow furrow which gives origin
to the M. teres. The M. micostalis arises from the middle two fifths of the Mrg. glenot-
deus, and its glenoid third gives origin to the M. meditriceps.

Metacromion.—This is better shown in Fig. 44 and 45.

§ 889. Processus Coracoideus—The coracoid process.—This, as better seen in Fig. 45,

THE ECTAL ASPECT OF THE SCAPULA., 155

projects sharply entad between the Fs. glenoidea and the Mrg. coracoideus. From its
extremity arises the M. coraevideus (Fig. 75). :

Ridges.—See Fs. subscapularis.

Tuberculum Bicipitale.—See Fig. 45.

§ 3890. Description
of Fig. 44.—The ectal
aspect of the scapula.

The principal feature
of this surface is the sub-
triangular lamina which
projects therefrom}; its
direction is approximately
longitudinal, but it is
more nearly parallel with
the longer part of the
coracoid border, and it
inclines in the opposite
direction. It begins as
a triangular elevation at
the vertebral border of
the scapula, and rises
rapidly to about the mid-
dle of the length of the
bone, where its edge is
thickened and roughened.
From this point toward
the glenoid end its eleva-
tion remains nearly uni-
form, but there are pro- fFygq. 44.—Tam Ecran Aspect oF aN ADULT LEFT Scap-
jections which will be ULA; x1.
described presently. This
ectal ridge is the mesoscapula or spine of the scapula.

§ 391. In the light of Embryology and Comparative Anatomy, the entire scapula may
be regarded as essentially a subcylindrical bar. With most Mammals the sides are pro-
duced in three directions so that a transection is irregularly 7-shaped ; the upright of the
T represents the ectal ridge just described, and the two arms of the cross-piece represent
the two lamine at right angles therewith which constitute the principal part of the bone,
and whose borders are respectively glenoid and coracoid. By Parker (A, 215), these three
regions are called respectively mesuscapula, postscapula and prescapula.

Consistently with these names, the glenoid border should be called Mrg. postscapularis,
and the coracoid Mrg. prescapuluris ; the fosse between them and the mesoscapula should
also be similarly designated. Since, however, the anthropotomical name for mesoscapula
is spine, and in the natural attitude of man its direction is approximately horizontal, these
fossze have been named iufraspinous and supraspinous, while the muscles arising there-
from are called infraspinatus and supraspinatus. Until it shall be agreed to change the
names of these muscles, it will probably be more convenient to retain the anthropotomical
names for the fosse.

§ 392. Acromion—Pre. acromialis—Acromion process (Fig. 30, 48, 46, 47).—This forms
the free extremity of the mesoscapula. Its ectal border is deflected slightly from the line
of the mesoscapula toward the coracoid border. In man it articulates with the clavicle,
but in the cat it is connected therewith by only a slender ligament or strip of fascia.

156

ANATOMICAL TECHNOLOGY,

§ 893. Delta Mesoscapule—The delta of the mesoscapula (Fig. 44).—We suggest this
as a suitable designation of the slightly elevated triangular rough surface at the vertebra}

end of the mesoscapula.

§ 894. Hussa Infraspinata—The infraspinous fossa.—This is the larger of the two ectal
fosse, and is distinctly triangular in shape. It is overhung by the mesoscapula and

metacromion.

§ 895. Hossa Supraspinata—The supraspinous fossa.—This is less regular in form than
the infraspinous fossa, and its area is less extensive ; but the muscle which occupies it is
larger than might be inferred, both:on account of the inclination of the mesoscapula and
its own projection beyond the coracoid border of the scapula.

Mesoscapula—Spine of the scapula.—See above (§ 380). P

§ 396. Metacromion—(Fig. 48, 67).—At its greatest elevation, near the glenoid end, the
mesoscapula is produced over the infraspinous fossa asa quadrate or subtriangular pro-

cess, the metacromion.

A; Glenoid end of right scapula,
Thel. bicipitale

S Pre. coracot deus.

-Fossa glenoidea

Fossa re
trochitercana-~-§

a %
x, b
a” C,?
Cx
4

B Head of right humerus,

Fie. 45.—THE GLENOID END OF AN ADULT
RieHr ScAPULA (A), AND THE PROXIMAL
END OF AN ADULT RigHT HUMERUS (B);
slightly reduced.

biceps at the root of the Pre. ( processus) coracoideus.

fossa presents a slight emargination.

Its ectal surface and free border are rough for the insertion of the

MM. levator clavicule and acromio-
trapezius.

§ 397. Tuberositas (Mesoscapule)—
The tuberosity of the spine of the
scapula.—At about midway between
the tip of the acromion and the delta
the mesoscapula is thickened and
roughened, constituting the tuberosity.

§ 398. Explanation of Fig. 45,
A.—This shows the glenoid end of a
right scapula. The bone is so placed
that the acromion appears less pointed
than the metacromion, the infraspi-
nous surface of the mesoscapula is
much foreshortened, and only a part.
of the glenoid border is shown; the
coracoid border is not represented at
all.

Between the acromion and the ectal
margin of the Fs. glenoidea is a deep
notch, the Jncisura magna (scapularis), .
or “ great scapular notch.”

§ 399. Fossa Glenoidea—This is
seen to be a shallow concavity with a
pear-shaped outline. The smaller end
forms a distinct Vbel. (tuberculum) bi-
cipitale for the attachment of the M.

Near this end, the ental border of the

§ 400. Pre. (processus) Coracoideus—The coracoid process.—This shows here to the
best advantage as a -hook-like process comparable with the beak of some birds (whence its
name), or with a half-bent finger, as suggested by Humpbrey (A, 366). At its base, oppo-
site the emargination near the smaller end of the Fs. glenoidea, is a nutrient foramen.

§ 401. Explanation of Fig. 45, B.—This represents the proximal end of a right

humerus, with the dorsal side uppermost.

When, therefore, the humerus and the scap-

ula are in contact at the shoulder, the upper and narrower part of the arthral surface of
the former is received by the lower and wider part of the Fossa glenoidea.

THE HUMERUS. 157

The general outline of the proximal end of the bone is approximately that of an irreg-
ular lozenge, the two smaller angles blunted, and one of the sides strongly indented. The
angles are dorsal and ventral, caudal and cephalic, while the sides face obliquely ventro-
cephalad, etc.

The following descriptions should be considered in connection with what is said of the
parts under Fig. 46 :—

§ 402. Canalis Bicipitalis—The bicipital canal or groove (Fig.30, 46, 69, 70, 75).—This
appears as a notch between the trochin and the trochiter, and is overhung more by the
former. Through it passes the tendon of the WV. biceps on its way to the Tbel. bicipitale
of the scapula (Fig. 45, A).

§ 403. Caput Articulare—The arthral head or anatomical head of the humerus (Fig.
30, 46, 68-71).—This presents a smooth convex surface which, as viewed perpendicularly
to the proximal end of the bone, is irregularly circular in outline. Really, however, it
extends upon the dorsal aspect of the bone, and is, as a whole, approximately triangular.
It is much larger than the Fs. glenoidea of the scapula with which it articulates, being
twice as long and more than half as wide again.

§ 404. Fossa Trochiteriana—The trochiterian fossa (Fig. 30, 68).—This is a depression
upon the cephalic aspect of the proximal extremity of the humerus near the tip of the
trochiter. Upon it is inserted the MW. infraspinatus.

§ 405. Trochin—The caudal, “inner ” or “ lesser” tuberosity (Fig. 3, 46, 69-73).—This
forms the caudal obtuse angle of the lozenge represented by the entire proximal aspect.

Notwithstanding the objections of Hyrt] (B, 200), we have employed the names epicen-
dylus, epitrochlea, trochiter and trochin, which were proposed by Chaussier and adopted by
Straus-Durckheim (A, I, 512).

§ 406. Trochiter—The cephalic, “outer” or ‘‘ greater” tuberosity (Fig. 30, 46, 68, 69,
71, 67, 74)—The proximal border of this forms the ventro-cephalic side of the lozenge rep-
resented by the entire proximal end of the bone.

THE HUMERUS (Fig. 6, 7, 80, 45, 46, 67-75, 105).

References.—Straus-Durckheim, A, I, 511-514; Owen, A, II, 511; Humphrey, A,
371-377 ; Chauveau, A, 83, 84; Chauveau (Fleming), A, 73, 74; Flower, A, 239, 246;
Leyh, A; Gray, A, 223-228 ; Quain, A, I, 85-87.

§ 407. General Description.—This is the single bone of the
brachium, the proximal segment of the arm. According to the
membral terminology suggested by Marsh (see § 83), it is the ce-
phalic O. propodiale. Its proximal and distal ends form with the
scapula and with the ulna and radius the shoulder and elbow joints
respectively.

In all Vertebrates excepting the “fishes,’’ that is, in all Am-
phibia, Reptiles, Birds and Mammals, excepting the armless
Amphibia (Cecilians) and Reptiles (serpents and a few lizards), the
humerus is present and gives attachment to numerous and impor-
tant muscles. In the cat, as partly shown upon Fig. 68-71, it affords
origin and insertion to many muscles.

158

ANATOMICAL TECHNOLOGY.

The humerus of the cat presents a subcylindrical shaft—the
diaphysis, and two enlarged and irregular ends—the Eatremitates

proximales and distales.

Viewed from the ventral or dorsal aspect, the caudal and ce-

Extremitag
proxtmaléa.

phalic outlines of the entire
bone are concave, the con-
cavity being both greater
and more regular on the cau-
dal side (on which the three
braces are placed). Seen,
however, from either the cau-
dal or cephalic side, as in

ee Fig. 68 and 70, the dorsal
and ventral outlines are
S-shaped. On the dorsal
side the sharper curvature
is near the distal end, while
the reverse is the case with
the ventral side. In other
words, the proximal extrem-
ity is more enlarged dorsad,
and the distal one ven-
trad. .

The cat’s humerus does
not present the appearance
of having been fwisted which
characterizes that of man
and some other Mammals—
an appearance which is due,
at least in part, to the devel-
opment of ridges with inter-
vening furrows having a
more or less distinctly spiral arrangement for the attachment or
accommodation of muscles, vessels or nerves.

Crista delfoidea Ve :

. epitrochle are.

Extremitas
diatalcs.

Capitétwm: Trockl ea.
Fie, 46.—TuHe VENTRAL (ANTERIOR) ASPECT
OF AN ADULT RicHT HuMERvUs; x1.

§ 408. Description of Fig. 46.—This represents the ventral aspect of the right
humerus, that which is most commonly and fully examined and compared. The same aspect
of the left humerus is represented in Fig. 69, and the cephalic, caudal and dorsal aspects
in Fig. 68,70 and 71 respectively.

§ 409. Canalis Bicipitalis—The bicipital canal or groove (Fig. 30, 45, 46, 69, 70).—
This is a marked depression upon the ventro-caudal aspect of the proximal extremity. As
better shown in Fig. 45, it lies between the eminences called trochiter and trochin. In the

THE HUMERUS. 159

fresh state it is converted into a foramen or closed canal by tendons which are inserted
upon these parts. Through it plays the tendon of the M. biceps, the one which represents
the “long” or “ glenoid” head of the muscle in man. By Straus-Durckheim (A. I, 512),
the canal is called ‘‘ coudisse bicipitale.”

§ 410. Capitellum (humeri)—The radial head, external or outer condyle (Fig. 30, 46, 6).
—The distal end of the bone presents a smooth saddle-shaped surface, the caudal border
of which is raised, and the cephalic border rounded. As seen from the ventral aspect, this
arthral surface is nearly equally divided by a slight ridge, and the convex caudal portion
is the capitellum. This surface narrows as it is continued over the distal end of the bone,
so that its shape, if extended in a plane, would be approximately lanceolate or pear-shaped,
with a distinct emargination at the cephalic side of the base.

With the capitellum articulates the fossa at the proximal end of the radius ; this end,
unfortunately, being likewise named capitellum. It would be well if anatomists could
agree to call one of these parts capitellum and the other capitulum.

_ § 411. Caput (humeri) Articulare—The arthral or anatomical head of the humerus.—
The smooth convex arthral surface of this part hardly appears in this view of the bone,
but is shown in Fig. 71. In man it is distinguished from the non-arthral surface of the
rest of the Hat. proximaiis by a furrow or constriction, the anatomical neck. In the cat,
this neck is not clearly defined.

§ 412. Crista Deltoidea—The deltoid ridge—‘‘ Créte deltoidienne externe,” Straus-
Durckheim (A, I, 513)—(Fig. 46, 68, 69)—This is a narrow, nearly straight, and—in well
marked adult humeri—sharply defined raised line extending from the tubercle for the
insertion of the M. micosiatis (Fig. 69) at the base of the trochiter on the cephalic aspect
of the proximal extremity distad and ventrad, to lose itself on the third fourth of the ven-
tral border. The sharpness which characterizes its proximal portion disappears at about
the middle of the bone.

§ 413. Crista Pectoralis—The pectoral ridge—“ Créte deltoidienne antérieure,” Straus-
Durckheim—(Fig. 46, 69).—This name is applied by us to the ill defined rough line upon
the proximal two thirds of the ventral aspect of the humerus.

This and the Crs. deltoidea converge distad, but cease to be distinct before meeting.
The long triangular interval between them is called by Straus-Durckheim (A, I., 513),
“ empriente deltoidienne.” Mivart applies (B, 92, Fig. 53), the name deltoid ridge to what
seems to correspond to this interval, and inaccurately states that the two parts of the
M. deltoideus above mentioned are inserted upon it.

§ 414. Diaphysis—The shaft (Fig. 46, 30, 68-71).—Although the shaft of the humerus
may be generally described as approximately cylindrical, it is slightly compressed, so that
at any point its cephalo-caudal diameter is less than its dorso-ventral. It is slightly
curved so as to present a ventral convexity.

For convenience of description, the entire bone may be said to consist of a subcylindrical
shaft and enlarged extremities. Strictly speaking, however, the diaphysis includes all
but the proximal and distal epiphyses, and these are less extensive than the regions desig-
nated as extremitates. In a young animal the proximal epiphysis separates along an
undulating line passing distad of the caput articulare and the tubercle for the insertion of
the M. micostalis. The greatest length of the epiphysis equals only about one eighth of
the length of the entire humerus, whereas the Hat. proximalis includes about one fifth. The
distal epiphysis also includes merely so much as bears the arthral surfaces with the epi-
trochlea and epicondylus, whereas the proximal limit of the at. distalis embraces also the
Fim. epitrochieare.

Upon the caudal aspect of the diaphysis, near the junction of the first and second
fourths, and nearer the ventral than the dorsal border, is to be seen, with adult humeri, a

160 ANATOMICAL TECHNOLOGY.

narrow longitudinal depression roughened for the attachment of the conjoined tendons of
the MM. teres (major) and /atissimus (dorsi). It is indicated by an interrupted line on
Fig. 70. On Fig. 45 it does not appear, but its proximal end would be opposite the proxi-
mal end of the longer brace. Its length equals the dorso-ventral diameter of the bone
opposite its distal end.

§ 415. Hpicondylus—The epicondyle or external condyle (Fig, 30, 46, 68, 69, 71, 74).—
This is a rough subconical eminence upon the cephalic aspect of the distal extremity. To
it is attached the proximal end of the cephalic (external) lateral ligament of the elbow,
and from it arise the MM. Extensor ulnaris and Ext. minimt. Obliquely proximad from
the epicondylus extends the Crista epicondylaris, which loses itself on the dorsal aspect of
the diaphysis nearly opposite the point of nearest approximation of the deltoid and pectoral
crests upon the ventral aspect.

The epicondyle has been called “outer” or “ external condyle,” and more recently
by Markoe (7) and others “‘ external epicondyle.”

§ 416. Epitrochiea—The epitrochlea or internal condyle (Fig. 30, 46, 69, 70, 71, 75).—
This is is a rough subconical eminence upon the caudal aspect of the distal extremity. It
is larger than the epicondylus, and springs abruptly from the nearly plane caudal surface
formed by the caudal prominence of the trochlea. Proximad, however, it is directly con-
tinuous with the bar forming the caudal boundary of the Wm. epitrochleare.

§ 417. Fim. (Foramen) Epitrochieare—The epitrochlear or supracondyloid foramen
(Fig. 30, 46, 69, 70, 75, 105)—This is a narrow perforation from the ventral to the dorsal
aspect of the humerus near the caudal side of the distal extremity. Through it pass the
N. medius and the A. brachialis on their way from the dorso-caudal to the ventral aspect
of the arm.

In the cat, the Fm. epitrochleare is within the naturally assigned limits of the Zt.
distalis, but it is wholly within the diaphysis ; its distal boundary is sometimes very near .-
the diaphysio-epiphysial suture, and sometimes separated therefrom by a space equal to
the longer diameter of the orifice.

The Fm. epitrochleare exists in the other Felide and in some other Carnivora (iiswer,
A, 246), and occasionally—partly circumscribed by ligament—in man (Humphrey, A, 373 ;
Quain, A, I, 87). Usually, however, the human humerus presents merely an emargination
of the bone, along which pass the median nerve and the brachial artery.

§ 418. Fossa Radialis and Fs. Ulnaris—The radial and ulnar fosse of the humerus
(Fig. 46).—On the ventral (anterior) aspect of the distal extremity of the humerus, just
proximad of the arthral surfaces of the trochlea and capitellum, are two slight depressions,
against which, in the strongly flexed condition of the elbow, abut the coronoid process of
the ulna (Fig. 30, Pre. coronoideus), and the side of the capitellum or proximal arthral end
of the radius (Fig. 30) ; hence their respective names. Between the two fosse, especially
in well marked bones, isa slight ridge. The Fossa ulnaris is described, but not named,
by Straus-Durckheim (A, I., 513).

§ 419. The Fossa olecranalis, on the dorsal aspect of the distal extremity, will be
described in connection with Fig. 71.

§ 420. Trochin and Trochiter—The caudal (lesser or inner) and the cephalic (greater
or outer) humeral tuberosities (Fig. 30, 45, 68-71).—These parts of the proximal extremity
_ have been described in connection with Fig. 45, and their muscular attachments will be
mentioned in connection with Fig. 68-71. See also above, Canalis bicipitalis. It has been
mentioned under Fig. 45 that while the trochin is wholly caudal in position, the trochiter
is about equally ventral and cephalic.

Trochlea—Fig. 46, 69, 71)—This is the half-saddle shaped arthral surface at the
caudal side of the distal end of the humerus. Its caudal border is raised and sharply

THE CARPALIA. 161

defined, but cephalad it is continuous with the capitellum, the limits of the two surfaces
being indicated by a slight ridge. Ventrad, the two surfaces are nearly equal in extent,
but dorsad the capitellum gradually narrows and disappears as seen in Fig. 71, while
the trochlea continues upon the dorsal aspect of the bone and has a decidedly oblique
direction.

THE CARPAMLIA (Fig. 6, 30, 47).

The bones of the carpus (wrist) have been enumerated in § 84.

References.—In addition to the references given in §§ 84, 85, see Gegenbaur, B;
Straus-Durckheim, A, I, 518-524; Mivart, B, 96-98; Gray, A, 285-241; Quain, A, I,
90-93, 99 ; Chauveau, A, 88, 89; Chauveau (Fleming), A, 78, 80; Leyh, A, 177-182;
Flower, A, 252-260; Humphrey, A, 387-390.

§ 421. Explanation of Fig. 4'7.—This represents the dorsal aspect of the carpus and
of the contiguous parts of the
metacarpalia of an Asiatic
lion seven months old, and
of two young dogs. The let-
tering is nearly uniform in
the three figures, but the
present description refers
only to the lion.

P, I, M, A, Mi, the meta-
carpalia of the pollex, in-
dex, medius, annularis and
minimus; p, the O. pisi-
forme, which is really a sesa-
moid bone in the tendon of
the M. flexor ulnaris, and

not a true carpal element;
u, m, td and tm, the unci- Fie. 47.—THe DorsaL ASPECT OF THE CARPAL REGION

forme, magnum, trapezoid oF A YouNG LION (LARGEST FIGURE) AND OF TWO

forming the distal row of
carpalia ; as stated in § 84, the unciforme is supposed to represent two elements of the
typical or primitive carpus.

The proximal row consists of but two cartilaginous pieces, 2 cont known as the
cuneiforme (py) and the scapho-lunare. Since cuneiforme has become well established in
the names of three of the tarsal bones, we have, upon the suggestion of Prof. O. C. Marsh
and in accordance with the custom of some European anatomists, substituted therefor the
term pyramidadle, which was employed by Straus-Durckheim (A, I., 520), This element
represents the u/nare of the primitive carpus.

The larger proximal piece is a single mass of cartilage, but a section shows that ossifi-
cation has begun from three separate centers. The two larger correspond to the scaphoides
(sc) and the /unare (1) of man, and to the radiale and intermedium of the primitive carpus.
The third and smaller center (ce) probably — the centrale of the primitive carpus,
which is not distinct in man,

So far as appears from the figure of Mivart (B, Fig. 60), the carpus of the cat is essen-
tially similar to that of the lion.

11

162 ANATOMICAL TECHNOLOGY.

CLAVICULA (Fig. 30, 48, 66, 67, 72).

The clavicle or collar bone is briefly described in § 212.

References.—Straus-Durckheim, A, I, 509; Flower, A, 228; Gegenbaur (Lankester),
A, 477; Gegenbaur, C; Gray, A, 215-218; Quain, A, I, 84, 96; Parker, A, 215; Hum-
phrey, A, 359-363.

*

§ 422. Explanation of Fig. 48.—This represents the unusually large and well
marked clavicles or collar bones of an old male cat. Their mesal or sternal ends are
apposed, and are seen to be approximately cylindrical.

The left is placed in nearly its natural

Se mesal attitude in the body, showing that its cephalo-
oe | caudal diameter is nearly uniform, and that
laterai Laterat each end curves slightly caudad, the mesal

Fig. 48.—Tue RicuT AND LEFT CLA- end the more decidedly.
Washoe OF AN OLD Cat: x1 The right is so placed as to show the

caudal aspect, and display the dorsal concav-
ity. The mesal half is nearly straight, but the lateral is quite regularly curved. The
dorso-ventral diameter of the bone increases gradually toward the lateral end, which is
about twice the width of the mesal.

Directly or indirectly, the clavicle affords attachment to the Mm. clavo-trapezius, clavo-
mastoideus and clavo-deltoideus, but as it is connected with the sternum and the scapula
only by ligaments, it is moved with the muscles instead of forming an efficient fulcrum
for their action.

THE STERNUM (Fig. 7, 30, 50, 72, 73, 99, 100).

The sternum or breast bone was briefly described in § 210.

References.—Straus-Durckheim, A, I, 496, 497; Mivart® B, 49, £0; Fiower, A, 73:
Humphrey, A, 321-329 ; Gray, A, 207-210; Quain, A, I, 25-27; Chauveau, A, 75; Chau-
veau (Fleming), A, 66; Leyh, A, 164-166 ; Parker, A, 215.

§ 423. Explanation of Fig. 49.—The ventral aspect of an adult sternum, with the
contiguous parts of the costicartilagines. Incomplete views of the sternum are given in
Fig. 30, 50, 72, 73, 99 and 100.

The sternum consists of a mesal series of osseous or partly cartilaginous segments
called sternebre, united by cartilages. The figure was drawn from a dried sternum, and
the intersternebral cartilages are not shown distinctly, neither is indicated the line of junc-
tion of the osseous and cartilaginous portions of the caudal segment.

Of the sternebre, the most cephalic and the most caudal have received special names,
presternum and xiphisternum. The intervening segments constitute the mesosternum.

§ 424 Mesosternum.—aAs indicated in § 210, there may be either 6 or 7 mesosternebre,
making the total number of sternebre 8 or 9. The variation is due to the presence or
absence of a short and nearly cubical piece between the xiphisternum and the sixth con-
stant mesosterneber. This piece is neither figured nor described by Mivart (B, Fig. 24),
or Parker (A, Pl. xxx, Fig. 3), and does not appear distinctly in the figures of Straus-
Durckheim (A, PI. vi, Fig. 2, and PI. vii, Fig. 2), notwithstanding his intimation (A, I, 546)
that it is always present. In the sterna examined by us this seventh piece is sometimes
quite large, and in other cases so small as to be unrecognizable, at least from the surface.
We have also observed considerable diversity as to the number of costicartilagines which
reach the sternum, but are not yet prepared to say whether 8 or 9 is the more frequent

THE STERNUM. 163

number. The costicartilages which reach the sternum articulate therewith diarthrodially,
but there is considerable diversity as to the extent of the synovial capsules.

Each of the constant mesosternebre is two or three times as long
as wide, and slightly enlarged at the ends so as to be somewhat of a
dumb-bell shape.

§ 425. Presternum.—tThis is sometimes called manubrium from
its form in man. It is nearly twice as long as the average mesoster-
neber, and the cephalic half, which is cartilage in the kitten, is com-
pressed and tapers to a blunt point. On each side is an oblique
shoulder for the attachment of the first costicartilage, so that the
entire presternum is shaped somewhat like the head of a lance. Its
ventral aspect is prominent on the meson, forming the presternal keel.

§ 426. Xiphisternum.—This is also called the ziphoid or enstform
cartilage. In the adult cat only the caudal third or fourth is cartilage,
and its tip is enlarged into a disk. The rest of the xiphisternum
tapers caudad from its base.

The sternum affords attachment to the MM. ectopectoralis, entopec-
toralis, sterno-mastoideus, sterno-hyoideus and some others.

§ 427. Relation of the Sternebre to the Costicartilagines.—While
dissecting, it is often desirable to designate the number of a sterneber
when the sternum is so covered by muscles as to make the enumera-
tion difficult. In these cases the ribs or their cartilages may usually
be counted from the most cephalic of the series, their relations to the
sternebre being as follows :—

With the six constant mesosternebra, the cartilages are attached
at the cephalic end, so that the third mesosterneber, for example,
which is the fourth sterneber, would be the segment just candad of
the point of attachment of the fourth cartilage. The first cartilages
are connected with the sides of the presternum, which is really the
first sterneber; the relations of the eighth and ninth cartilages are
less definite and constant.

mesosternum.

COST (RIBS) AND COSTICARTILAGINES (COSTAL CARTI-
LAGES). Fig. 30.

References.—Straus-Durckheim, A, I, 492, and II, 57; Quain,
A, I, 27, 141; Gray, A, 210, 295 ; Flower, A, 85 ; Chauveau (Fleming),
A, 67, 140 ; Chauveau, A ; Leyh, A, 162, 209 ; Humphrey, A, 329-337 ;
Mivart, B, 50-52.

Fie. 49.— THE VEN-

ASPEC
§ 428. The coste or ribs—13, rarely 14, on each paps irae

side—constitute a series of arched, highly elastic wom; x1.
bones which, with their continuations, the costicar-
tilagines, the sternum and the thoracic vertebre, form the conical
skeleton or framework of the thorax (Fig. 30 and 50).

The ribs and their cartilages are slender and subcylindrical in
form. They present, in expiration and moderate inspiration, a com-
pound curve, the convexities being caudal and lateral (Fig. 30 and

164 ANATOMICAL TECHNOLOGY.

50). The ribs proper have each a general caudal inclination from
the tuberculum to the arthron costicartilaginis, while the carti-
lage has a cephalic inclination from the arthron to the sternal end
(Fig. 30). In full inspiration the ventral or sternal ends of the ribs
are nearly ventrad of the vertebral ends, the caudal convexity being
partly or entirely obliterated (Fig. 50).

§ 429. Special Characters.—The capitellum of the 12th and
13th ribs—14th if present—articulates with but a single vertebra.

The capitellum of the first articulates to a slight extent with the
body of the last cervical, but the diarthrodial part of the articula-

tion is entirely confined to the body of the first thoracic (Flower, ,

A, 23). The first rib and those last named above (12, 13, 14), pos-
sess no ligamentum interarticulare (Fig. 50).

The 12th and 13th ribs—14th if present—possess no arthral
tuberculum ; it is also sometimes absent from the 11th. The tuber-
culum of each of the others articulates diarthrodially with the
diaphysis of the vertebra corresponding to it in number; thus, the
tuberculum of the first articulates with the diapophysis of the first
vertebra, and that of the seventh with the diapophysis of the sev-
enth, ete.

§ 480. Sternal, Asternal and Floating Ribs.—The cartilages of

the first nine ribs (Fig. 49)—rarely of only the first eight—are articu-

lated with the sternum, and hence are called sternal ortrueribs. The
remaining three (or four) are called asternal or faése ribs, as their
cartilages do not reach the sternum. Finally the 13th—14th if pres-
ent—is not attached to the one just cephalad of it by connective
tissue, as are the 10th, 11th and 12th, but ends independently in
the abdominal muscles, and hence is called a floating or vertebral
rib. (Humphrey, A, 329, 337; Hutchinson, A, 1016.

§ 431. Methods of Demonstration.—The form and the various
parts of the ribs are best made out in those that have been com-
pletely deprived of their soft parts as directed above (§ 248). The
relations and mobility of the ribs singly and collectively, and their
arthra and ligaments, must be studied on fresh or alcoholic speci-
mens.

§ 432. Elasticity and Mobility.—Take as lean a cat as possi-
ble, place it dorsicumbent, and, commencing at the ventrimeson,
remove the skin and muscles covering the sternum, and the ribs
with their cartilages of one side. Press upon the thorax, and the
elasticity of the ribs will be felt. Grasp the second mesosterneber

COSTH AND COSTICARTILAGINES. 165

and pull ventro-cephalad. This will show the way in which the
capacity of the thorax is increased.

§ 433. Arthra—Joints.—Remove the muscles covering the tu-
berculum and cervix of the seventh rib for example, and the diga-
ments will be seen as white bands holding the tuberculum to the
diapophysis and the capitellum in the socket formed by the demi-
facets of the two vertebree (Fig. 52, Arthron capitelli). Cut away the
ligaments on the caudal side of the tuberculum with the arthrotome
and bend the rib cephalad. This will expose the smooth arthral
surface of this diarthrodial joint. That of the capitellum may be
demonstrated in the same way.

To demonstrate the amphiarthrodial joints at the arthron costi-
cartilaginis, the finger or some solid substance should be placed
entad of the arthron, and then the ectal surface of the bone and car-
tilage should be sliced away with the arthrotome. The cartilage
and bone will be found continuous, the ends not being separate
and smooth for gliding upon each other as with the capitellum
and tuberculum. The end of the rib is but very slightly hollowed
out to receive the cartilage, thus differing from the condition in
man, where the cartilage is implanted in a deep pit.

The diarthrodial joints of all the sternal ribs (8 or 9) at the junc-
tion of the costal cartilages and sternum (§§ 424, 480), may be dem-
onstrated by slicing off the ectal surface of the conjoined sternum
and cartilage as directed for the Arthron costicartilaginis.

§ 434. Ligamentum interarticulare—Interarticular ligament
(Fig. 50).—This is most satisfactorily demonstrated in one of the
middle ribs, the seventh for example. The muscles should be re-
moved as for demonstrating the tubercular and capitellar joints,
and the ligaments binding the tuberculum to the diapophysis should.
be cut. Nip away the neural arch (Fig. 53) and remove the short
segment of exposed myelon. This will expose the floor of the neu-
ral canal. Dissect the dorsal (posterior) common ligament from the
intervertebral fibro-cartilage, move the rib, and the ligamentwm
interarticulare will be seen, as a rope in a pulley, passing across
the floor of the neural canal in a groove on the dorsal surface of the
intervertebral fibro-cartilage, and connecting the heads of the pair
of ribs (§ 444).

§ 435. This ligament differs so remarkably from its homologue in man that a brief com-
parison is added :—
In man the ligament is plate-like. In the cat it is thick and band-like. In man it

166 ANATOMICAL TECHNOLOGY.

completely divides the arthral surface of the capitellum into two parts corresponding to
_ the demifacets of the two vertebre (Fig. 52, Arthron capitelli). In the cat it but partially
divides the surface. In man the ligament joins the intervertebral fibro-cartilage, and does
not extend from side to side. In the cat it passes from side to side in a synovial groove
lined by an extension of the synovial membrane lining the joints of the capitella of the
pair of ribs. Hence, while in man there are four separate Synovial cavities for the capitella
of each pair of ribs possessing the interarticular ligament, in the cut there is but one, since
the arthra of the capitella communicate with each other through the groove for the Liga-
mentum interarticulare.

References.—Bichat, A, I, 231; Mayer, 47, 273; Chauveau, A, 140; Leyh, A, 210;
Cleland, 4 and 5; Quain, A, I, 141; Gray, A, 296; Gage, 5, 421.

§ 436. Preparation.—Fig. 50 represents two coste and costi-
cartilagines separated from the body and in the position assumed
during the fullest possible
inspiration—that is, drawn
ventrad, laterad and cepha-
lad so as to obliterate their
caudal convexity (Fig. 30),
and give the greatest capa-
city to the thorax. The.
cleaning process was carried —
only sufficiently far to re-—
move the soft parts, leaving
the interarticular ligament
and the connections of the
costal cartilages and _ster-
num (§§ 252, 427).

§ 437. Arthron costicartilagi-
/ = mnis.—The amphiarthrodial articuia-

*cnammnnmmn Apthran costicartilaginis =-==-“G27 tion between the sternal end of the
) diaphysis and its cartilage (§ 488).

§ 438. Arthron mesosternebri
— Costo-sternal articulation. — The
\ diarthrodial articulation of the costal

cartilage with the mesosternum, The

Artheon mesosterne bri.
. 7

os first costal cartilage articulates with a

Fre. 50.—CaupaL VIEW oF THE SEVENTH Parr Single sterneber (presternum), the

or Costa (Rips); x1. other eight with two (§ 430, Fig. 49).

§ 489. Capitellum—Head.—The

vertebral end of the rib ends in a somewhat pear-shaped capitellum or head which articu-

lates diarthrodially with the demifacets of two contiguous vertebre (Fig. 52, Arthron

capitellt.)

§ 440. Cervix—Neck.—The cervix or neck of the rib is the somewhat constricted

part immediately following the capitellum and between it and the tuberculum.

PELVIS. 167

§ 441. Costa—Rib—The costa or rib proper is the bony part of the arch extend-
ing from the capitellum to the Arthron costicartilaginis, It has two. extremities—
vertebral or dorsal and sternal or ventral ; two surfaces—ectal and ental: two edges—
cephalic and caudal, The vertebral end bears the capitellum: the ectal surface is next
the skin ; the cephalic edge faces toward the head.

§ 442. Costicartilago—Costal cartilage——The cartilaginous continuation of the rib
which passes from the sternal end of the diaphysis toward the sternum (§ 423, Fig. 49). In
the figure it is deeply shaded and is between the Arthron costicartilaginis and the meso-
sterneber.

§ 443. Diaphysis (Costz)—Shaft.—The diaphysis of the rib is the part between the
tuberculum and the Arthron costicartilaginis.

§ 444. Ligamentum interarticulare, az.—Interarticular ligament.—This is a strong,
smooth, band-like ligament connecting, through the floor of the neural canal, the heads
of opposite ribs (2d to 11th pairs inclusive) ; ($ 434).

§ 445. Mesosternebra, az.—The square area between the sternal ends of the costal
cartilages represents the caudal end of the 5th mesosterneber (§ 424, Fig. 49).

§ 446. Tuberculum—Tubercle.—The tuberculum is an elevation on the ectal surface
of the rib just at the end of the cervix. It bears a smooth arthral facet which articulates
(diarthrodially) with the diapophysis of the 7th thoracic vertebra (Fig. 52 and § 433).

PELVIS.

General References to the Pelvis.—Straus-Durckheim, A, I, 499, and II, 63; Quain,
A, I, 100, 122, 159 ; Gray, A, 245 ; Chauveau (Fleming), A, 91,161 ; Chauveau, A, 75, 152;
Leyh, A, 166, 212; Flower, A, 281 and 33; Humphrey, A, 438 ; Joulin, 1 ; Mivart, S
and 19; Wilder,10. A chronological bibliography is given at the end of the last.

§ 447. Preparation.—The soft parts were fully removed by one
of the processes already described (§§ 244-256). Parts of the first
and second sacral vertebrze were removed with nippers to expose the
Arthron ilio-sacrale. To show the lines of junction between the
ilium, ischium, Os pubis and Os cotyloideum, it is necessary to
prepare the pelvis of a cat retaining its milk teeth.

§ 448. Arthron ilio-sacrale—lIlio-sacral articulation.—This is
the articulation between the sacrum and the ilium. In the figuze
the arthral surface on the ilium is brought into view by the re-
moval of part of the sacrum. The caudal third of this surface is
diarthrodial, the cephalic two thirds amphiarthrodial ; the motion,
however, is very limited.

The lateral masses of only the first sacral vertebra articulate
directly with the ilium.

§ 449. Crista ilii—Lliac crest.—The iliac crest is the prominent
dorso-cephalic projection of the ilium (Fig. 30, 51, § 230).

§ 450. Fm. (Foramen) obturatorium—Obturator or thyroid
foramen.—The large oblong space bounded by the os pubis and
the ischium.

168 ANATOMICAL TECHNOLOGY.

§ 451. Fossa cotyloidea—Cotyloid fossa, Acetabulum.—The
cotyloid fossa is a deep cup-shaped cavity in the lateral aspect of
the innominate bone which articulates diarthrodially with the head
of the femur. The third of the circumference of the cavity next the

obturator foramen is absent, thus
producing the cotyloid notch. A
rough depression extends from
this notch about half way across
the floor of the fossa.

§ 452. Ilium.—This is the ce-
phalic part of the os innomina-
tum. It articulates with the
‘sacrum and forms a considerable
part of the cotyloid fossa.

§ 453. Ischium—The dorso-
caudal part of the pelvic bone.
It forms a large part of the coty-
loid fossa and about one third of
the pubic symphysis.

§ 454. Os cotyloideum—Co-
tyloid bone.—A small bone form-
ing the ventral part of the floor
of the cotyloid fossa. Straus-
Durckheim, A, I, 502; Milne-
Edwards, A, X, 358. It has not
been detected in man, and can be
seen as a separate bone only in
immature cats.

§ 455. Os innominatum—In-
4) nominate or pelvic bone.—The os
Fia. es Rac VIEW Ee Cars jnnominatum is made up of the

Fe WIRE ADIACENT FERTEBRS. lium, the ischium, the os pubis

re S Pe OR Send tn oe cotyloideum. These

four bones are completely united
in adult life. The right and left pelvic bones together form the
pelvic girdle.

§ 456. Os pubis—Pubic bone.—It is the cephalo-ventral of the
bones forming the pelvic girdle. It forms only a small part of the
cotyloid fossa and about two thirds of the symphysis pubis.

§ 457. Pelvis, az.—‘‘ The two innominate bones, together with

COLUMNA VERTEBRALIS. ~ 169

the sacrum, form the pelvis, a complete circle of bone, or rather a
short tube.’’—F lower, A, 284.

Pre. trans., Processus transversus.— Transverse process or
diapophysis of the 7th lumbar vertebra.

§ 458. Sacrum, @z.—‘‘ The portion of the vertebral column to
which the pelvic girdle is attached.’’ It is composed of three ver-
tebree, which in adult life are more or less completely consolidated.

In an immature cat which would show well the lines of demar-
cation between the bones forming the Os innominatum, the sacral
vertebree would be but partly codssified.

§ 459. Symphysis pubis, az.—This is the linear articulation
(amphiarthrodial) between the ventral aspects of the two innomi- °
nate bones. Its cephalic three fourths is formed by the Os pubis
and the caudal fourth by the ischium. In fully adult animals the
symphysis usually becomes anchylosed.

Vert. (Vertebra) lumbalis.—The last or 7th lumbar vertebra
(Fig. 55).

Vertebre caudales, az.—Tail vertebree.—These follow imme-
diately after the sacrum (Fig. 30).

§ 460. In addition to the parts named above, the following should be mentioned :—

A. The Ilio-pectinedl Line and Eminence.—Neither are shown in Straus-Durckheim’s
figure, from which this was copied. Both should show on the right side, however. The
line extends from the ilio-sacral articulation to the most prominent part of the pubis.
Opposite the cephalic edge of the acetabulum the line presents an eminence which is at or
very near the junction of the ilium and pubis.

B. The Tuberosity of the Ischium.—This is the most prominent thickened part of the
ischium. It forms the extreme dorso-caudal part of the whole pelvis. It is upon this part
the cat rests when sitting on her haunches.

COLUMNA VERTEBRALIS.

References.—Straus-Durckheim, A, 458; Quain, A, I, 9, 25 ; Gray, A, 132; Hum-
phrey, A, 113; Milne-Edwards, A, X, 325; Leyh, A, 153; Chauveau, A, 19; Owen, A,
II, 483 ; Owen, 231; Cuvier, A, I, 170; Flower, A, 10; Mivart, 3 and 24; Maclise,
A, 622; Cleland, 7 and 13; Wilder, 10.

§ 461. The Columna vertebralis, spine, vertebral or spinal col-
umn, consists of a series of osseous segments called vertebre arranged
in close connection with each other and forming the bony axis of the
body. It is nearer the dorsal than the ventral aspect in the cat
and in most other Vertebrates. Its position and curves are shown
in Fig. 30. It is prolonged caudad beyond the trunk to form the

170 ANATOMICAL TECHNOLOGY.

axial support of the tail; and cephalad it is articulated diarthro-
dially with the occipital region of the skull. ‘The different verte-
bree, with some exceptions (§ 458), remain through life distinct from
each other, though closely connected by means of fibrous struc-
tures which permit a certain but limited amount of motion between
them.”’

§ 462. “Although the vertebre of different regions present
great diversities of form, there is a certain general resemblance
among them showing a common plan of structure. This plan is,
however, worked out variously in different regions by change of
form and the suppression or superaddition of parts, thus fitting
-them to fulfill their special purpose.’’—F lower, A, 10.

In general, each vertebra is composed of a solid subcylindrical
centrum or body, and a bony arch (neural arch), with various
processes, extending dorsad therefrom (Fig. 52-55).

§ 463. Regions of the Vertebral Column.—For convenience of
description, the whole vertebral column has been divided into five
regions, named in order from the head :—Cervical (7) ; Thoracic or
Dorsal (13) ; Lumbar (7) ; Sacral (3) ; Caudal or Tail (22), (Fig. 30).

The middle Cervical, Thoracic and Lumbar vertebrz are shown
in Fig. 53-55, where the special characters of these three groups are
well illustrated.

§ 464. Distinguishing the Five Groups of Vertebre and the
Ends of the First Four Groups.—The cervical vertebree, except the
7th, are distinguished by the presence in the diapophysis of the
vertebrarterial foramen (§ 473).

The 7th cervical is distinguished from the thoracics by the ab-
sence from its prominent diapophysis of an Arthron tuberculi, and
by the absence of an Arthron capitelli from the cephalic end of the
centrum (Fig. 52). It differs from the other groups by its short
wide centrum, large neural foramen and slender neural spine.

The thoracic vertebree differ from all the others by the presence
of an Arthron capitelli on the cephalic end of the centrum or upon
both ends.

The Zwmbar vertebre may be distinguished by their long sub-
cylindrical centra, and by the cephalic inclination of the neura-
pophyses and of all the diapophyses except the first.

The sacral vertebre are more or less completely anchylosed.

The caudal vertebre: differ from the others by the smallness or

CERVICAL VERTEBRZ.. 171

absence of the neural foramen, the caudal inclination of the dia-
pophyses when present, and by the presence in some (2d to 9th) of
the so-called chevron bones.

§ 465. The chevron bones are small ossicles attached to the cephalo-ventral part of the
caudal vertebre and forming an open or closed arch through which passes the caudal con-
tinuation of the A. sacra media.

The ends of the vertebre may be distinguished very readily by remembering that the
arthral surface of the preeygapophysis (Fig. 53), situated at the cephalic end of the verte-
bra, faces either dorsad or dorso-mesad, while that of the postzygapophysis faces ventrad
or ventro-laterad. It follows from this that the postzygapophyses overlie the prezyga-
pophyses like the tiles on a roof. Especially in the thoracic and lumbar regions, the Jnei-
sura vertebralis or intervertebral notch is much deeper on the caudal than on the cephalic
side. The above characters apply also to man.

§ 466. Demonstration.—All of the general as well as special
points relating to the vertebral column may be demonstrated on a
flexible natural skeleton (§ 252) and one entirely divested of its soft
parts. The relation of the myelon and other soft parts must of
course be demonstrated on a fresh or alcoholic specimen.

§ 467. Preparation—(Fig. 52).—The cleaning (§ 252), was carried sufficiently far to
divest this part of the vertebral column of all its soft parts except the intervertebral fibro-
cartilages.

§ 468. Arthron capitelli—Capitellar articulation.— This is the diarthrodial arthral cay-
ity formed in two adjacent thoracic vertebre for the reception of the capitelium or head of
the rib (Fig. 50). The part of the articulation in each vertebra is called a demifacet. The
12th and 13th vertebre have each a complete capitellar arthral surface. The caudal part
of the last cervical vertebra supports part of the capitellum of the first rib; Flower, A, 23.

§ 469. Arthron tuberculi—This is the diarthrodial facet on the diapophysis for
articulation with the rib corresponding in number to the vertebra from which the dia-
pophysis arises (Fig. 50, 52). It is not present in the last two thoracic vertebre.

§ 470. Atlas.—The atlas is the first cervical vertebra, and thus the first of the entire
series. It articulates diarthrodially with the occipital condyles (Fig. 57). The broad lat-
eral masses are the diapophyses or transverse processes, and are sometimes called “ wings
of the atlas.”

§ 471. Axis.—This is the second of the cervical vertebre. It articulates diarthrodi-
ally with the atlas, but with the third vertebra by the interposition of fibro-cartilage, that
is, amphiarthrodially, like the remaining vertebre, except the sacrum (§ 458). Its neural
spine is a long sharp ridge (Fig. 30).

Cerv.—Vertebre cervicales, cervical vertebrx 1-7.

§ 472. Fibro-cartilago intervertebralis, az.—Intervertebral fibro-cartilage Between
each of the centra, except the first and second and the parts of the sacrum, is this very

‘dense, tough and elastic fibrous material. ‘‘The elasticity provides for the vertebrae
always returning to their normal relation to each other and the column generally when
they have been disturbed therefrom by muscular action.”—Flower, A, 12.

§ 473. Foramen vert., Fm. vertebrarteriale.—This is the canal through the bases

172 ANATOMICAL TECHNOLOGY. |

of the diapophyses of all but the last (rarely of the
last) cervical vertebrae. Through it pass the verte
bral artery and vein.

§ 474, Foramen atlantale—Atlantal foramen.—
This isa passage through the cephalic edge of the
atlas just dorsad of the occipito-atlantal arthron. It
transmits the first or suboccipital nerve and the
vertebral artery ; Straus-Durckheim, A, I, 470. It
is present in man only as an exception ; Quain, A,
I, 12.

§ 475. Lamella ventralis—Ventral or inferior
lamella.—This is the thin plate-like projection ex-
tending ventrad from the diapophyses of some of the
cervical vertebre. It is most marked in the 6th,
Flower, A, 22, 23.

§ 476. Pre. (Processus) odontoideus, az.—Odon-
toid process,—This is a tooth-like projection from the
cephalic part of the centrum of the axis. It articu-
lates diarthrodially with the atlas, and serves as a
pivot on which the atlas and head rotate. It is kept
from encroaching upon the neural canal by a strong
ligament.

§ 477. Explanation of Fig. 53-55.—Anapophy-
sis—Accessory tubercle.—This is a slender process
extending laterad from the caudal part of the neural
arch. It is ventrad of the postzygapophysis, and with
it clasps the preezygapophysis of the following verte-
bra. Itis present in the first six lumbar vertebre, and
markedly in the 9th to the 13th thoracics, where, in
man, it is called the inferior tubercle; Quain, A, I, 14,

§ 478. Arcus neuralis, az—Neural arch.—This
is a bony arch projecting from the dorsal aspect of
the centrum. It is called neural arch because it over-
arches and encloses the myelon or neural axis.

i § 479. Canalis neuralis, az.—Neural canal.—The

EW Arthron . neural canal is formed by the neural foramina, each

~ tubercule. foramen being a short segment of the canal. It is

Fig. 52.—VENTRAL ASPECT OF enclosed by the neural arches and by ligaments, and
THE CERVICAL AND: OF TWO contains the myelon.

THORACIC VERTEBREE. (From § 480. Centrum, az.—Body.—The vertebral cen-

eee arom heim.) x 1 trum is the solid subcylindrical ventral portion of the

vertebra. Contiguous vertebral centra articulate

amphiarthrodially by means of an interposed disk of fibro-cartilage. For exceptions, see

§ 458. ,

§ 481. Diapophysis—Transverse process.—The diapophysis is the lateral projection
of the vertebra, Its base, in the cervical vertebre (Fig. 52), except the 7th, contains the
vertebrarterial foramen (§ 473).

§ 482. Fm. (Foramen) neurale, az.—Vertebral ring or foramen,—This is the space

VERTEBRA. buss

enclosed by the neural arch and the dorsal aspect of the centrum. The neural foramina
of all the vertebrae, together with the ligaments, form the newral canal.

§ 483. Fm. (Foramen) vertebrarteriale.—This foramen is found in the base of the
diapophyses of all the cervical vertebre except the last, and rarely in that. In man it is
usually present in the last; Humphrey, A, 142. This foramen transmits the Arteria et
Vena vertebralis (Fig. 104).

§ 484. Inc. (Incisura) vertebralis—Notch.—The pedicles are notched, especially on
the caudal side. When the vertebre are united these notches
form the so-called intervertebral foramina, through which
pass the vessels and nerves to and from the neural canal.

§ 485. Lm. (Lamina) neuralis—Lamina.—The two
laminze form the roof of the neural arch, Laterally they join
the pedicles, and from their junction at the meson springs
the neural spine.

§ 486. Metapophysis—Mammillary process.—This is a
dorso-lateral projection of the preezygapophyses of the lumbar
vertebrae. It corresponds to the internal tubercle of the tho-
racic transverse processes; Quain, A, I, 15. Fie. 53.—CAuDAL VIEW

§ 487. Pedicle.—The pedicle of a vertebra forms the oF THE FouRTH CER-
side of the neural] arch. It extends dorsad and joins the | vicAL VERTEBRA; x1.
lamina.

§ 488. Prezygapophysis—Superior articulating process—This process articulates

m. neuralis

Fie. 54.—CAuDAL VIEW OF THE SEVENTH FG. 55.—CAUDAL VIEW OF THE FOURTH
THORACIC VERTEBRA; x1. LUMBAR VERTEBRA; x1.

diarthrodially with the postzygapophysis of the preceding vertebra, The arthral surface
of this process faces nearly dorsad or dorso-mesad.

§ 489. Postzygapophysis—lInferior articulating process—The postzygapophysis ar-
ticulates diarthrodially with the prezygapophysis of the vertebra immediately following
it. Its arthral surface faces nearly ventrad or ventro-laterad.

§ 490. Sp. neu.—Spina neuralis—Neural spine, Spinous process, az.—This is a
mesal process arising from the neural arch and extending approximately dorsad.

THE SKULL.

General References to the Skull.—Straus-Durckheim, A, I, 380; Quain, A, I, 31;
Gray, A, 149; Humphrey, A, 175; Darling and Ranney, A, 17; Cuvier, A, II, 177; Owen,

sir.»
7a

174 ANATOMICAL TECHNOLOGY.

A, IT, 492; Flower, A, 94; Huxley, B, 245; Morrell, A; Milne-Edwards, A, X, 306:
Gegenbaur, A, 463; Leyh, A, 122; Chauveau, A,37; Chauveau (Fleming), A, 33; Parker
and Bettany, A; Parker, 25; Turner, 4, 848-9 ; Huxley, 3, 238; Wyman, 76: Cuvier,
B, VII.

§ 491. “ The skull (Fig. 56-62) is the term commonly applied to
the portion of the axial [somatic] skeleton situated within the head.”
It is a strong bony case or frame enclosing the brain and affording
support and protection to the organs of sight, smell, taste and
hearing.

It consists of several irregular bones, most of which are immova-
bly united by sutures (synarthroses), so that their relative position,
and hence the form of the skull, are constant.

In addition to the skull proper, there are articulated to its base
the mandible (Fig. 62) and the hyoid apparatus (Fig. 30, § 224).

§ 492. Cranium and Face.—For convenience, anatomists have
divided the skull into these two regions. The cranium is the caudal
part of the skull; it encloses and protects the brain. The face is
the cephalic part ; it surrounds the mouth and nasal passages, and,
with the cranium, completes the cavities for the eyes. Quain, A, I,
31, 74; Flower, A, 94, 102.

The number of separable bones entering into the formation of the
skull varies with the age of the animal. The teeth are not meluded.
The bones given in the following tables and figures may be easily
demonstrated on the skull of a cat with milk teeth.

§ 493. Sutures.—The sutures or lines of union between the
various bones of the skull have not all received special names, but
all may be properly named by forming a compound term of the
names of the two bones united, as; Sutura parieto-frontalis in-
stead of S. coronalis ; S. maxillo-premazillaris, etc. Quain, A, I,
56, 58, 131.

§ 494. Bones of the Skull. Modified from the Tables of Quain,
A, 74, and Flower, A, 104. (Fig. 56-62.)

In the following Tables of the bones, the names in parenthesis beneath a given name
are synonyms ; and the names behind the small or secondary braces are the anthropo-
tomical equivalents of those in black letter behind the large braces.

The word Os (bone), or its equivalent 0.,is to be understood before all the technical
names of the bones excepting Vomer and Mandibula.

———

BONES OF THE

SKULL. 175

BASILAR PROCESS OF THE OCCIPITAL

BONE.

JAUDAL PART OF THE BODY OF THE
SPHENOID BONE, INCLUDING THE
SELLA TURCICA.

CEPHALIC PART OF THE BODY OF THE

SPHENOID BONE.

TABULAR PART OF THE OCCIPITAL

BONE.

DORSO-CEPHALIC ANGLE OF THE TABU-

CRANIUM.
{ BASIOCCIPITALE..... ;
BASISPHENOIDEUM. 1
MESAL (5)-- 1 prmspHENOIDEUM. {
(Single or Azy-
gous Bones). SUPRAOCCIPITALE.. |
| INTERPARIETALE.... i

{ EXOCCIPITALE

PERIOTICUM.....

@ourinuacdoont.S
Petrosum or
Petrosale),

TYMPANICUM......

SQUAMOSUM........
(Squamo-Zygomati-
cum).

LATERAL (10). { papmrate....

(Paired Bones).
ALISPHENOIDEUM..

PTERYGOIDEUM..

ORBITO-SPHENOI-
DEUM... “cf

FRONTIS... . snes

FACE.

MESAL (2)
(Single or Azygous
Bones).

Bee sna

ETHMO-TURBINALE |

r
; MESETHMOIDEUM...

[ ROMeMB: Uisncrace des

LAR PORTION OF THE OCCIPITAL.

CONDYLAR PORTION OF THE OCCIPI-
TAL BONE.

Bie PETROUS AND MASTOID POR-
TIONS OF THE TEMPORAL BONE;
THE FIRST INCLUDING THE
LABYRINTH AND MEATUS AUDI-
TORIUS INTERNUS.

THE TYMPANIC RING AND AUDITORY
PROCESS. THE AUDITORY BULLA
AND THE POSTGLENOID PART OF
THE TEMPORAL BONE.

THE SQUAMOUS PART OF THE TEM-
PORAL BONE WITH THE ZYGO-
MATIC PROCESS, INCLUDING THE
ARTHRAL SURFACE FOR THE
MANDIBLE.

THE PARIETAL BONE.

GREAT WINGS OF THE. SPHENOID
BONE WITH THE LATERAL (EX-
TERNAL) PTERYGOID PLATES.

| THE MESAL (INTERNAL) PTERYGOID
PLATES.
THE LESSER WINGS OF THE SPHE-
NOID BONE,
| ee FRONTAL BONE.

THE LATERAL MASSES WITH THE
DORSAL AND VENTRAL TURBI-
NATED BONES OF THE ETHMOID,

THE CRIBRIFORM PLATE, AND
THE OS PLANUM OR ORBITAL
PLATE OF THE ETHMOID

THE VERTICAL (MESAL) PLATE OF
THE ETHMOID BONE, INCLUDING
THE CARTILAGINOUS NASAL
SEPTUM.

THE VOMER, OR OS VOMERIS.

176 ANATOMICAL TECHNOLOGY.

LOWER JAW OR MANDIBLE OR
MAXILLA INFERIOR,

{ RAMUS MANDIBULA- THE TWO RAMI UNITE TO FORM THE
RIS

PALATINUM.......... THE PALATE BONE.
THE SUPERIOR MAXILLARY OR UP-
MAXILLARE.......... PER JAW BONE EXCEPTING THE
INCISOR PART.
LATERAL (8). 4 MAXILLO-TURBINALE THE INFERIOR TURBINATED BONE.
(Paired Bones). MEATATGS cyt case cts THE MALAR BONE.
( INTERMAXILLARY, THE _ INCISOR
PRASMAXILLARE...... PART OF THE SUPERIOR MAXIL-
LARY BONE.
LACHRYMALE. ...... THE LACHRYMAL BONE.
L NAGATA coer AUS. THE NASAL BONE,

§ 495. Articulations of the Bones of the Skull. (Fig. 54-60).

The following list represents the bones approximately as given in standard works on
Human Anatomy. They are readily distinguishable in a nearly adult cat.

The parts forming a compound bone are given in parenthesis immediately below the
name of the bone under consideration. See Os occipitale.

The Arabic number in parenthesis, after a bone and just before the brace, indicates the
number of bones with which it articulates. The parts of a compound bone are numbered
as one. See Os parietale.

In giving the articulations of the mesal bones, the Arabic numeral 2 is placed in paren-
thesis after all the lateral bones with which it articulates, to indicate that it is connected
with both. See Vomer.

If but one of the parts of a compound bone articulates with a given bone, the name of
that part is given instead of the name of the whole bone; but if more than one compound
enters into the articulation, the name of the whole bone is given, and that is followed by a
brace and the names of the components. See Os parietale.

CRANIUM.
( CAUDAD siiahdeeeets Sheehy Her ATLAS.

OS OCCIPITALE (6). {

(Basioccipitale, ;
Exoccipitale, PARIETALE (2).
Supraoccipitale, with the CEPHALAD..:.......e00.+++ 4 [EMPORALE (2).
Interparietale). L BASISPHENOIDEUM.
r BASIOCCIPITALE,
OAUDAD S. pccimtesscs | earcusen @
: TEMPORALE ie
PARIETALE (2).
DORBAD .. (sth x0 carcass Fronts (2).
OS SPHENOIDEUM (13).. ; ETHMOIDEUM (2),
(Basisphenoideum ( PALATINUM (2).
Alisphenoideum, ; | FRONTIS (2).
Pterygoideum, CEPHALAD 33. 25%. 5. ETHMOIDEUM (2).
Presphenoideum, t MESETHMOIDEUM.
Orbito-sphenoideum). L VoMER.

ARTICULATIONS OF THE SKULL. 177

( CAUDAD.... OCCIPITALE.
DORSAD.... PARIETALE.
RAMUS MANDIBULARIS,
VENTRAD.. | eorpus,
BASIOCCIPITALE.

OS TEMPORALE (6).. 1 wnsan..... Feet pes vik All Sh Baa
(Perioticum, ‘ * ( sphenoideum,
Tympanicum Ali- and __basi-
Squamosum). SPHENOIDEUM. ; sphenoideum.

CEPHALAD. PARIETALE.
L | MALARE,
Supraoccipitale,
CAUDAD... LO ee ; Interparietale,
SQUAMOSUM.
Squamosum,
OS PARIETALE (5)... venprap., ) TEMPORALE... Perioticum.
ALISPHENOIDEUM.
MESAD...... PARIETALE (the platetrope).
| CEPHALAD. FRonrIs.
( PARIETALE.
CAUDAD,...... ; ALISPHENOIDEUM.
ORBITO-SPHENOIDEUM,
PALATINUM.
VENTRAD..... 4 py adie:
OS FRONTIS (8).......... 4 | LACHRYMALE,
Os FRONTIS (the platetrope).
MESAD........ : dicted bled
ETHMOIDEUM.
CEPHALAD.... ~ MAXILLARE,
q NASALE,
( ; FRONTIS.
CAUDAD..... PRASPHENOIDEUM.
FRONTIS.
DORSAD...... } role
PRA&SPHENOIDEUM.
os ETHMOIDEUM (9) Sty VENTRAD... es Sade tne
(Ethmo-turbinal, lamina cribrosa), ean MESETHMOIDEUM,
eae ETHMOIDEUM (the platetrope).
FRONTIS.
LATERAD... <~ MAXILLARE.
[ PALATINUM,
FACE,
CAUDAD...... PRa&SPHENOTDEUM.
FRONTIS (2).
OS MESETHMOIDEUM (8).. J DorsaD...... { Noxms 2)
VENTRAD.... VoMeEr.
LATERAD..... ETHMO-TURBINALE (2).

12

178 ANATOMICAL TECHNOLOGY.
(MAP DADS 6 0.60 0% - PRASPHENOIDEUM.
MESETHMOIDEUM.
DORSAD....... uy ; Part pe ears (eh
VOMER (r0). see eer eee eee eee < PALATINUM (2).
VEN TRAD Ss scthee MAXILLARE (2).
PRA MAXILLARE (2).
| LATERAD......... PALATINUM (2).

RAMUS MANDIBULA-
RIS (3)

OS PALATINUM (7)... ¢

OS MAXILLARE.

OS MAXILLO-TURBINALE (a).

Processus
CATIDAD: Hacweecese i TEMPORALE... ; zy gomaticus.
OS MALARE (3)... 4 MESO-CEPHALAD.. LACHRYMALE.
Processus
| CEPHALAD Piette. ; MAXILLARE... ; Een

DORSAD....

LATERAD...

CAUDO-DORSAD. SquaAMosuM.

..++ 4 SPHENOIDEUM. j

| Pterygoideum.
PRASPHENOIDEUM.
FRONTIS.
ETHMO-TURBINALE.

VOMER.

PALATINUM (the platetrope).
ETHMO-TURBINALE.
PRASPHENOIDEUM.
VOMER.

MAXILLARE.

( FRONTIS.
LACHRYMALE.

CAUDAD. ... PALATINUM,

MALARE.

VOMER.

NASALE.

PRAMAXILLARE,.

ETHMO-TURBINALE.

MAXILLO-TURBINALE.
| PALATINUM.

PRAMAXILLARE,

L CEPHALAD..

LACHRYMALE.
ETHMO-TURBINALE.

MAXILLARE.
FRONTIS.

{ CAUDAD.....
DORSAD.....

LATERAD... ;

( MAXILLARE.
Peg: ( CAUDAD..... Bevo
MESAD...... Pax. (the platetrope).

MESAD........... RM. MNDBL. (the platetrope).

Presphenoideum.

MAXILLARE (the platetrope).

\

DORSAL ASPECT OF THE SKULL. 179

la

PLANUM.
CAUDAD..}. 20... i Piainatne. d
MAXILLARE
DORSAD 25) 3525.08 :
OS LACHRYMALE (5)..... 4 | Prox
ALARE.
LATERAD......... ; trie nie tts
‘ MAXILLO TURBINALE.
| CEPHALAD....... | “etn neat
{ CAUDAD......... Fronts.
ETHMO-TURBINAL.
OS NASALE (6).:.....00 200: VENTRAD...... 4 despemwoIDEUyt
MBSAD....2.... NASALE (the platetrope).
MAXILLARE.
Li EERO esos ' PRAMAXILLARE.

All the figures of the skull are of /edis domestica.

In the description of the figures, under the general heads, which are arranged alphabet-
ically, the special parts are named commencing at the caudal extremity.

For fuller information concerning any of the bones or foramina, refer to the Table of
Bones and of Foramina, pp. 175, 190.

§ 496. Preparation.—The soft parts were entirely. removed
(§ 250, B). The roof of the left. side was then removed by sawing
carefully with a fine saw to the meson at a level just dorsad of the
orbits and about 2 mm. dorsad of the foramen magnum. The
frontal and parietal bones were then removed with nippers by sep-
arating them at the coronal, the sagittal and the lambdoidal sutures.
Finally, the interparietal and supraoccipital were removed by saw-
ing on the meson tili the first incision was reached. This exposed
the frontal sinus and the ental surface of the base of the skull.

§ 497. Cn. Ich., Canalis lachrymalis—Lachrymal canal.—This canal passes ceph-
alo-ventrad and lies between the maxilla and maxillo-turbinal. It finally opens into the
nasal cavity just ventrad of the maxillary attachment of the maxillo-turbinal and nearly
opposite the fang of the canine tooth.

§ 498. Cst. Imd., Crista lambdoidalis.—The lambdoidal crest corresponds to the
superior curved line of the occipital in Human Anatomy. Flower, A, 112, 132.

§ 499. Cst. temp., Crista temporalis—Temporal crest.—This marks the dorsal
limit of the temporal fossa and muscle. In young cats it is considerably separated from
the meson, but in adults it approaches it and may be mesal from the lambdoidal crest to
the coronal suture. The mesal part is then called sagittal crest ; Flower, A, 112.

Fm. m., Foramen magnum, az.

Fm. j., Foramen jugulare—s. lacerum posterius.—Jugular or posterior lacerated
foramen.

Fm, ov., Foramen ovale.

Fm. rt., Foramen rotundum.

Fm. l. a., Foramen lacerum anterius—s. lacerum orbitale, s. fissura sphenoida-
lis.—Anterior or orbital lacerated foramen, sphenoidal fissure.

Fm. op., Foramen opticum—Optic foramen.

180 ANATOMICAL TECHNOLOGY.

§ 500.. Fm. plt., Foramen palatinum posterius—Posterior palatine foramen.—The
passage between the opening shown in this figure and Fig. 60 is known as the “sided
palatine canal. Quaiu, A, I, 373.

$ 501. Fm. sphplt., Foramen spheno-palatinum—Spheno-palatine foramen.—It
leads from the orbit into the nasal cavity.

Fie. 56.—DorsaL VIEW OF THE SKULL; x 1.2.

§ 502. Fs. ap., Fossa appendicularis.—Fossa for the appendicular lobe of the
cerebellum. ;

§ 503. Fs. (Fossa) temporalis—Temporal fossa.—This is the space on the side of
the skull caudad of the postorbital process of the frontal. By mistake, the name in this
figure is written partly in the orbit.

$ 504. Fossa. orbitalis—Orbital fossa, orbit—In this space the eyes are found in
living animals. Unlike the orbital fossa of man, that of the cat is not separated from the

temporal by a plate of bone, but opens widely into it.

DORSAL ASPECT OF THE SKULL. | 181]

§ 505. I., Infundibulum.—This is the opening from the frontal sinus to the nasal
cavity.

§ 506. M. a. i., Meatus auditorius internus—Internal auditory meatus.—This is
divided into two parts very near its mouth, as shown by the white line. The ventral part
receives the auditory nerve (VIII), the dorsal part, the facial/(VI1). The facial in its course
curves round in the dorso-lateral part of the Pars petrosa and finally emerges at the stylo-
mastoid foramen. This passage through the skull from the M. a. i. to the stylo-mastoid
foramen is known as the Aquzductus Fallopii. In the Pars petrvsa, about 2 mm, from
its mouth, there branches cephalad a small canal, the Hiatus Fallopii, which opens oppo-
site the ventral end of the osseous tentorium.

§ 507. O. soc., Os supraoccipitale, az.—Supraoccipital bone.—This forms the caudal
part of the roof of the cranial cavity.

§ 508. O. i. p., Os interparietale, az.—Interparietal bone.—A small bone, separate in
young animals. It is cephalad of the supraoccipital and is wedged in between the caudal
ends of the parietals.

§ 509. O. parietale—Parietal bone.—The parietal bone forms a large part of the side
and roof of the cranial cavity.

§ 510. O. perioticum—s,. petrosum.—This is a part of the temporal bone; it encloses
the internal ear, and is divided into two parts, Pars petrosa and Pars mastvidea, the latter
appearing on the ectal surface of the skull (Fig. 57).

§ 511. O. temporale—Temporal bone.—This forms part of the floor and side of the
ovata and by its zygomatic process helps to enclose the temporal fossa.

§ 512. O. boc., Os basioccipitale, az.—Basioccipital bone.—It forms part of the floor
of the cranium.

§ 518. O. bsph., Os basisphenoideum, az.—It forms the caudal part of the body of
the sphenoid bone, and helps to make the floor of the cranial cavity.

§ 514. O. alsph., Os alisphenoideum,—This is one of the greater wings of the sphe-
noid and forms part of the side and floor of the cranium.

§ 515. O. orsph., Os orbito-sphenoideum.—This is one of the lesser wings of the
sphenoid ; it forms part of the floor and side of the cranium and part of the mesal wall
of the orbit.

'$ 516. O. frontis—The frontal bone.—The frontal bone forms a large part of the roof
and part of the side of the cephalic region of the cranial cavity and the mesal wall of the
orbit. It also covers the caudal part of the nasal cavity.

§ 517. O. plt., Os palatinum—Palate bone.—This is a very complex bone, fing
part of tae orbit, of the roof of the mouth, and of the floor and side of the nasal cavity.

§ 518. O. malare—s. Os zygomaticum, os jugale—Malar, zygomatic or jugal bone.—

This bone connects the malar and zygomatic processes of the maxilla and the temporale, and
with them encloses laterally the orbit and the temporal fossa, and completes the Zygoma
or zygomatic arch.

§ 519. O. pin., Os planum.—This is not a separate bone, but merely the orbital part
of the ethmo-turbinal. It is often absent.

§ 520. O. Ich., Os lachrymale—Lachrymal bone.—It is a thin quadrilateral bone
forming part of the cephalic wall of the orbit and the caudal part of the nasal cavity.

§ 521. O. maxillare—Maxilla, superior maxillary or upper jaw bone.—This is a com-
plex bone which forms a great part of the face. Init are implanted the dorsal (upper)
molar, premolar and canine teeth.

§ 522. O. nasale—Nasal bone.—A thin irregular bone forming part of the roof of the
nasal cavity.

182 ANATOMICAL TECHNOLOGY. °

Fic. 57.—VENTRAL ASPECT OR BASE OF THE SKULL. (Modified from Straus-Durck-
heim); x 1.75.

§ 523. O. pmx., Os premaxillare—Premaxillary or intermaxillary bone.—It forms
the most cephalic part of the skull, and in it are implanted the dorsal (upper) incisor
teeth. :
Pre. z., Processus zygomaticus.—Zygomatic process of the temporal bone.

BASE OF THE SKULL. 183

Prec. po., Processus postorbitale.—Post orbital process of the frontal bone.

§ 524. S. (Sinus) frontalis—Frontal sinus.—This cavity in the frontal bone is sep-
arated from its platetrope by a bony partition (Fig. 60). It communicates with the nasal
cavity through the infundibulum (I.) and is lined by an extension of the nasal mucous
membrane.

§ 525. Sutura lambdoidalis, az.—Lambdoidal or occipito-parietal suture.—This is the
synarthrodial articulation between the parietal, the interparietal and the supraoccipital
bones.

§ 526. Sutura sagittalis, a—Sagittal suture.—The synarthrodial articulation between
the right and left frontal and the parietal bones. It extends from the nasal bones to
the lambdoidal suture.

In Human Anatomy, the sagittal suture is confined to the articulation of the two parie-
tals with each other, the two frontals uniting so early that they are considered as a
single bone.

§ 527. Sutura coronalis—Coronal or parieto-frontal suture.—The synarthrodial artic-
ulation between the frontal and parietal bones.

§ 528. Fig. 57—Preparation.—The skull was thoroughly
cleaned, and while still moist the following structures were removed
from the right side :—

(A) The tympanic bulla was removed by inserting an arthro-
tome between it and the basioccipital and prying steadily, thus
exposing the Pars petrosa, the Foramen lacerum jugulare and Fm.
lacerum medium, the Fenestra ovalis and Fenestra rotunda.

(B) The Os pterygoideum and a part of the Os palatinwm were
removed by the nippers to expose the row of foramina.

(C) The teeth were extracted with the nippers to expose the
alveoli (sockets of the teeth).

a, b.—Fractures made in removing the bulla.

Bulla tympanica.—Tympanic or auditory bulla (Fig. 58).

§ 529. Cd. oc., Condylus occipitalis—Occipital condyle—tThe occipital condyle is
formed mostly by the exoccipital, but somewhat also by the basioccipital. It articulates
diarthrodially with the atlas.

Cn. eu., Canalis Eustachiana.—Eustachian canal (Fig. 58).

D. m.; Dens molaris.—Molar tooth.

DD. pm., Dentes premolares.—Premolar teeth.

D. c., Dens caninus.—Canine tooth.

DD. i., Dentes incisores.—Incisor teeth.

Fm. m., Foramen magnum, az.

§ 580. Fm. cd., Foramen condylare—Condylar foramen.—This foramen is some-
times nearly hidden either by the projection of the bulla or its unusual approach to the
Fim. jugulare. -

§ 531. Fm. j., Foramen jugulare—s.lacerum posterius.—Jugular or posterior lacer-
ated foramen.

§ 582. Fm. stm., Foramen stylo-mastoideum—Stylo-mastoid foramen.—This is
the ectal termination of the Agueductus Fallopii (Fig. 56, 59, M. a. i.).

§ 533. Fm. 1. m., Foramen lacerum medium—s. Fm. spheno-petrosum—Middle

184 ANATOMICAL TECHNOLOGY.

lacerated, or spheno-petrosal foramen.—The opening of this foramen on the ectal sur-
face of the skull is just within the mouth of the Eustachian canal. It perforates the lateral
edge of the cephalic projection of the bulla, and may be seen on most prepared skulls by
looking into the mouth of that canal.

The existence of the Foramen lacerum medium in the cat is not mentioned by any of
the authorities, so far as we are aware ; but the foramen so named in this figure is between
the cephalic extremity of the pars petrosa and the alisphenoideam—the position occupied
by the foramen lacerum medium in man, as stated by Quain, A, I, 62, and in the dog, as
stated by Flower, A, 101. This foramen in the cat also transmits an artery, which has
been called internal carotid in the table of foramina (§ 562). It is so called since it anas-
tomoses with the cerebral vessels within the cranium, and arises from the carotid at the
proper place—slightly centrad of the origin of the lingual—although it passes along the
mesal side of the bulla and not in a carotid canal, as stated by Mivart, B, 208,209. The
artery is imbedded in the wall of the Eustachian tube in its passage along the Eustachian
canal to the foramen.

Fm. ov., Foramen ovale.

Fm. rt., Foramen rotundum.

§ 534. Fm. 1. a., Foramen lacerum anterius—s. fissura sphenoidalis—Anterior
lacerated foramen or sphenoidal fissure.
Fm. op., Foramen opticum, transmitting the Nervus opticus.

§ 535. Fm. plt. p., Foramen palatinum posterius—Posterior palatine foramen.—
There are usually two openings of the posterior palatine canal in the roof of the mouth as
shown in this figure. (See also Fig. 56.)

Fm. pit. a. Foramen palatinum anterius—s. Fm. incisore.—Anterior palatine or
incisor foramen.

§ 536. Fs. tyh., Fossa thyrohyalis.—This is the pit into which is inserted the
dorsal part of the Os hyoides (§ 224).

§ 587. Fs. (Fossa) mandibularis—Mandibular or glenoid fossa.—This receives the
mandibular condyle and articulates diarthrodially with it (Fig. 62).

§ 588. Ft. rt., Fenestra rotunda—This opening connects the tympanum with the
scala tympani of the cochlea. In the living body it is covered with membrane.

§ 539. Ft. ov., Fenestra ovalis.—This connects the tympanum with the vestibula,
In living bodies it is closed by the stapes and its connecting soft structures.

§ 540. M. a. e.,, Meatus auditorius externus—External auditory meatus.—This
extends from the side of the head to the ectal surface of the Membrana tympani.

§ 541. Margo alveolaris—Alveolar margin or border of the jaw.—In this border of
the jaw the teeth are implanted.

. supraoccipitale, az.—Supraoccipital bone.
exoc., Os exoccipitale.—Exoccipital bone.
. basioccipitale, az.—Basioccipital bone.

. basisphenoideum, az.—Basisphenoid bone.
alsph., Os alisphenoideum (Fig. 56).

pt., Os pterygoideum.—Pterygoid bone.
presph., Os presphenoideum, az.

orsph., Os orbito-sphenoideum (Fig. 56).

. frontis (Fig. 56).

vm., Os vomeris.—Vomer (Fig. 59).

. palatinum.—Palate bone (Fig. 56).

. malare.—Malar bone (Fig. 56).

O. maxillare.—Maxillary or upper jaw bone (Fig. 56).

2909099099000

- JHE BULLA TYMPANICUM. 185

O. pmx., Os premaxillare.—Premaxillary or intermaxillary bone.

§ 542. Pre. par., Processus paroccipitalis—s. paramasioideus—Paramastoid or
paroccipital process.—This is a curved shelf-like projection of the exoccipital which abuts
against the caudal end of the bulla.

Pre. pro., Processus mastoideus—s. pars mastoidea.—Mastoid portion of the peri-
oticum.

Pre. z., Processus zygomaticus.—Zygomatic process of the temporal ae

Pre. po., Processus postorbitale.—Postorbital process of the frontal bone.

§ 543. Fig. 53—Preparation.—The soft
parts were removed ; then, while the skull
was yet moist, the ventral face of the bulla
was ground off on a fine emery-stone.
It might be removed with a watch-spring
saw or on an ordinary grindstone. In
grinding, the pressure should be only
moderate to avoid breaking the delicate
septum.

§ 544. Bulla tympanica—The auditory or tympanic
bulla,—The bulla is a hollow subspherical part of the
O. tympanicum enclosing the tympanum or middle ear. =—

A delicate bony septum divides the cavity into two un- Fie. 58. — VENTRO - LATERAL
equal parts. This septum arises from the floor, and VIEW OF THE LEFT BULLA
extends dorsad, but leaves a space over the fenestra ro- AND ADJACENT Parts; x 1.5.
tunda which puts the two cliambers in communication.

In the lateral aspect of the bulla is the external auditory meatus (M. a. e.); attached to
the ectal part of this is the external ear, and to the ental part the Membrana tympani or
ear drum, which completely separates the tympanum or middle ear from the exterior of
the body. Flower, A, 110, and 26,4; Huxley, B, 249 ; Straus-Durckheim, A, I, 409.

Cd. oc., condylus occipitalis.—Occipital condyle.

§ 545. Cn. eu., Canalis Eustachiana—Eustachian canal.—This is a short bony tube
leading from the tympanum to the ventral surface of the skull. Flower, A, 111.

Fm, m., Foramen magnum, az.

Fm. cd., Foramen condylare.—Condylar foramen.

Fm. ov., Foramen ovale.

Fs. PEF Fossa mandibularis.—Mandibular or gienoid fossa (Fig. 57),

Fs. <t., Fenestta rotunda (Fig. 57).

Ft. ov., Fenestra ovalis.

M. a. e., Meatus auditorius externus.—External auditory meatus.

O. boc., Os basioccipitale, az.—Basioccipital bone.

Pre. z., Processus zygomaticus.—Zygomatic process of the temporal bone.

Spt. tym., Septum tympanicum.—The bony partition dividing the interior of the
bulla into two unequal chambers.

§ 546. Fig. 59—Preparation—The soft parts were removed
($ 250, B), and then the section was made with a watch-spring saw
while the skull was still moist. The section was made about 2 mm.

186 ANATOMICAL TECHNOLOGY.

to the left of the meson to avoid injuring the mesethmoideum and
other mesal parts. The remaining parts of the left half were after-
ward removed with the nippers ; the septa of the frontal and sphe-
noidal sinuses were likewise partly removed.

Be. pel.

Fie, 59,—HEMISECTION OF THE SKULL, Rigut Smpe; x15.

Bulla tym., Bulla tympanica.—Tympanic or auditory bulla (Fig. 58).

Fm, j., Foramen jugulare—s. Fm. lacerum posterius—Jugular or posterior lacer-
ated foramen.

Opposite the occipital condyle and nearly caudad of the condylar foramen is an un-
named opening for a vein.

Fm. op., Foramen opticum.—Optic foramen.

Fm. sphplt., Foramen spheno-palatinum.—Spheno-palatine foramen.

Fs. ap., Fossa appendicularis (Fig. 56).

§ 547. Fosse of the Cranial Cavity(A) Fossa cerebellaris, az.—Cerebellar
fossa.—This is the part of the cranial cavity caudad of the osseous tentorium. It contains
the cerebellum and medulla (Fig. 88).

(B) Fossa cerebralis, az.—Cerebral fossa.—This is the part of the cavity of the skull
between the tentorium caudad and the olfactory fossa cephalad. It contains the cere-
brum, thalamus, part of the optic lobes and the crura (Fig. 88).

(C) Fossa olfactoria—s. rhinencephalica—Olfactory or rhinencephalic fossa.—This
is the smallest of the fosse. It is limited cephalad by the Lamina cribrosa and extends
caudad to the dorso-ventral ridge formed by the frontal and orbito-sphenoid. It lodges
the rhinencephalon or olfactory lobes (Fig. 88).

M. a. i., Meatus auditorius internus.—Internal auditory meatus (Fig. 57).

O. exoc., Os exoccipitale.—Exoccipital bone (Fig. 56).

O. soc., Os supraoccipitale, az.—Supraoccipital bone,

HEMISECTION OF THE SKULL. 187

. ip., Os interparietale, az.—Interparietal bone.
boc., Os basioccipitale, az.—Basioccipital bone.
pro., Os perioticum.—Periotic bone (Fig. 59).
bsph., Os basisphenoideum, az.—Basisphenoid bone.
temporale.—Temporal bone.
parietale.—Parietal bone (Fig. 56).

pt., Os pterygoideum.—Pterygoid bone.
alsph., Os alisphenoideum.—Alisphenoid bone.
. plt., Os palatinum.—Palate bone (Fig. 57).

. orsph., Os orbito-sphenoideum.

. frontis.—Frontal bone (Fig. 56).

§ 548. O. vomeris, a2—Vomer.—The vomer is a mesal bone forming part of the
septum of the nasal cavities.

§ 549. O. mesethmoideum, az,—Vertical plate of the ethmoid.—This is a mesal bone
forming most of the partition between the nasal cavities.

O. Nasale.—Nasal bone.

O. mxtrb., Os maxillo-turbinale—Maxillary or inferior turbinated bone.—It is a
greatly plicated bone occupying the ventral prt of the nasal cavity. ,

g 550. O. ethtrb., Os ethmo-turbinale—Ethmo-turbinal bone.—This is also a greatly
plicated bone ; it occupies the dorsal and greater half of the nasal cavity. 1t projects
caudad into both the frontal and the sphenoidal sinuses (Fig. 60).

O. pmx., Os premaxillare —Premaxillary or intermaxillary bone (Fig. 57).

O. mx., Os maxillare—The upper jaw bone.—In this figure it is not marked, but it
is the deeply shaded part just caudad of the 0. Prima.

Pre. pcl., Processus postclinoideus, az.—Posterior clinoid process.

Pre. prel., Processus preclinoideus, az—Preclinoid process.

Sella, Sella turcica, az.—This is a space or pit formed by the two clincid processes
(Fig. 88).

§ 551. S. sph., Sinus sphenoidalis—Sphenoidal sinus.—This is a space in the pre-
sphenoid bone. It is separated from its platetrope by a bony partition. It is lined by a
continuation of the nasal mucous membrane, and communicates freely with the nasal
cavity.

S. frn., Sinus frontalis.—Frontal sinus (Fig. 56, 60).

§ 552. Tent., Tentorium.—The osseous tentorium cerebelli is a moderately thick
plate of bone projecting from the parietal bones into the cranial cavity ; it separates the
cerebrum from the cerebellum (Fig. 88). .

Each parietal bone furnishes half of the tentorium, and its halves are conjoined at the
meson by a ventral continuation of the sagittal suture ; (see Fig. 88).

200999999000

§ 553. Fig. 60—Preparation.—The skull was divested of its soft
parts (§ 250, B). It was then sawed obliquely across its cephalic
half so as to include the optic foramina, and to fully expose the
frontal sinuses. The left lateral wall of the olfactory fossa was
nipped away, and likewise the lateral projections of the maxilla.

Cn. Ich., Canalis lachrymalis.—Lachrymal canal (Fig. 56).
Fm. (Foramen) opticum—Optic foramen.—The optic chiasma rests in the groove
between the two foramina (Fig. 114).

188 ANATOMICAL TECHNOLOGY.

Fm. sphplt., Foramen spheno-palatinum.—Spheno-palatine foramen.
Fm. infor., Foramen infraorbitale.—Infraorbital foramen.
§ 554. Lm. (Lamina) cribrosa—Cribriform plate of the ethmoid.--The mesethmoid
separates the bones of the two sides. The cribriform plate is the cranial part of the eth-
moid, the ethmo-turbinals properly belonging to the face.
O. presph., Os presphenoideum, az.—
Presphenoid bone.
O. pit., Os palatinum.—Palate bone.
O. Ich., Os lachrymale.— Lachrymal
one (Fig. 56).
1 O. planum (Fig. 56).
Gath.” | eihtth, (On. ethino-tmibianbecttth:
mo-turbinal bone.—In this figure is shown
the rounded scroll-like part projecting into
the frontal sinus (§ 550).

O. frontis.—Frontal bone.

Sinus frontalis.—Frontal sinus (Fig. 56).

: ¢
Lm, crcebros

“Plt. § 555. Fig. 61—Preparation.—
After the removal of the soft parts
gq fm. optteum. (§ 950, B), the rami were separated
at the symphysis menti (Fig. 62).
Fie. 60.—DoRso-cAUDAL VIEW OF THE
LAMINA CRIBROSA AND THE SINUS § 556. An. (Angulus) mandibularis—
FRONTALIS ; x 1.5. Mandibular angle.
Cd. mndb., Condylus mandibularis.—
The condyle or arthral head of the mandible (Fig. 62).

D. m., Dens molaris.— Molar tooth.

DD. pm., Dentes premolares—Premolar teeth.—The bicuspides of Anthropotomy.

D. c., Dens caninus.—Canine
tooth.

DD. i., Dentes incisores.—
Incisor teeth.

Fm. m, Foramen mentale—
Mental or labial foramen.—There
are almost invariably two on each
side in the cat.

Fs. (Fossa) coronoidea—Cor-

. onoid fossa.—F rom this fossa arises —
a large part of the masseter muscle, Fic. 61.--LATERAL VIEW OF THE LEFT MANDIBU-

Prc. cor., Processus coronoi- LAR Ramus; x1.
deus.—Coronoid process.

§ 557. Ramus, Ramus mandibularis—Mandibular ramus.—The mandible is made
up of two similar bones joined at the symphysis menti, and these rami form the frame-
work of the floor of the mouth; Flower, A, 120.

In Human Anatomy, the “ramus” is the so called “ ascending part,” and not the
entire half of the mandible as here; Quain, A, I, 54.

§ 558. Fig. 62—Preparation.—All the soft parts were removed

err emenerr ae

DORSAL ASPECT OF THE MANDIBLE. 189

($ 250, B); while still moist the two rami were slightly separated
at the symphysis menti, and the teeth of the right side were
extracted with the nippers to show the alveoli, as in Fig. 57.

DD.
| EBS orm

Fie. 62.—DorsaL VIEW OF THE MANDIBLE. (Modified from Straus-Durckheim), x1.75.

§ 559. Alveoli.—These are the cavities in which the teeth are implanted.

§ 560. Cd. (Condylus) mandibularis—Mandibular condyle or arthral head.—This
smooth cylindrical process articulates diarthrodially with the Hossa mandibularis of the
temporal (Fig. 57).

D. m., Dens molaris.—Molar tooth.

DD. pm., Dentes premolares.—Preemolar teeth.

D. c., Dens caninus.—Canine tooth; Wilder, 75.

DD. i., Dentes incisores.—Incisor teeth.

Fm. di,, Foramen dentale inferior.—Inferior dental foramen.

Margo alveolaris—Alveolar margin—The margin or border of the jaw in which the
teeth are implanted.

Prc. (Processus) coronoideus.—Coronoid process.

§ 561. Symphysis menti.—The symphysis is the amphiarthrodial articulation be-
tween the two rami. It is indicated in the figure by a dark line just to the left of the
incisor teeth. In old cats this symphysis often becomes anchylosed, but in young individ.
uals considerable motion is possible between the two rami.

190

ANATOMICAL TECHNOLOGY,

§ 562. Table of the Foramina and Canals of the Skull, the Bones
enclosing them, and the Principal Structures to which they

give Passage.

The foramina are enumerated, commencing at the caudal end of the skull, Fig. 56, 62.
All are lateral or paired except the foramen magnum, which is mesal.

BONES ENCLOSING | STRUCTURES THAT TRAV-
1 aan THE FORAMINA. | ERSE THE FORAMINA.
Basi- ex- and supra-| { Myelon, N. (spinalis) accessorius
Foramen magnum .......... j occipitale......... | (XI), A. basilaria
Foramen condylare......... Exoccipitale........ N. hypoglossus (XII).
Basi- and ex-occipi-| ( N. vagus (X), N. (spinalis) acces-
Foramen jugulare........... tale, tympanicum sorius (XI), N. glasso-pharyn-
and pars petrosa.. geus (IX), Vena jugularis.

Foramen stylo-mastoideum..

Meatus auditorius internus. .

Aquzductus Fallopii

Hiatus Fallopii..

Meatus auditorius externus..

Foramen lacerum medium
(§ 533)

ee ee

Foramen ovale

Foramen rotundum.

see ee ewes

Foramen lacerum anterius...

Foramen opticum

Foramina olfactoria.........
Foramen palatinum posterius

Foramen spheno-palatinum..
Foramen palatinum anterius.
Foramen orbitale...........
Canalis lachrymalis

eee eee ee

Foramen infraorbitale
Foramen dentale inferius....

Tympanicum, ase
mastoidea. .

:
;

'

5

sete eee

Pars petrosa

Pars petrosa, pars
mastoidea, 7
panicum.

Pars petrosa

Tympanicum.... ..
Pars petrosa, basi- ;

sphenoideum.. {
Alisphenoideum, bul-
la tympanica.....

Alisphenoideum ...

Alisphenoideum ...

Ali- and pel cscs ing
noideum..........

Orbito-sphenoideum.

Lamina cribrosa...
Palatinum

Palatinum..........

Maxillare, premax-
illare.
Palatinum, maxillare
Lachrymale, max-
illare, maxi
Maxilare. jssccaw sou

turbinale.
Mandibula........
Mandibula

|

ee

a

Foramina mentalia.... .....

N. facialis (VII).

N. auditorius internus (VIII), N
facialis (VII), A. auditoria in-
terna.

N. facialis (VII).

petrosalis superficialis (ec-
talis), (branch of Vidian).
Admits air to the membrana
tympani.

Arteria carotidea interna.

M

Tuba Eustachiana, A. carotidea
interna (§ 533).

N. maxillaris inferior (8d divi-
pera of V); small meningeal

N. elas superior (2d or
middle division of V).
N. epeepalmons (1st division of
), N. oculomotorius (III), N.
pA Mish (VI), N. trochlearis
\ (IV), A.carotidea externa (large
branch from the rete mirabile).
N. opticus (II) ; a meningeal ar-
‘tery.
NN. olfactorii.
NN. palatini, AA. palatine.
NN. spheno-palatini, AA. sphe-
no-palatine.

N. naso-palatinus, A. nasalis.

|
ie
t
:

N. oculo-nasalis, A. ethmoidalis.
Ductus lachrymalis.

N. infraorbitalis, A.infraorbitalis,
{ N. dentalis inferior, A. et V
dentales inferiores.
N. mentalis, A. mentalis.

THE STRUCTURE OF BONE. 191

§ 563. The capacity of a prepared skull may be obtained by filling it through the
Fm. magnum with sand or fine shot, and then pouring the material into a graduate glass.
If the material used in determining the capacity is fine enough to pass through the fora-
mina, they must be plugged in some way.

The weight of the brain may be obtained approximately by reckoning the cubic centi-
meters of capacity as grams and adding 4 per cent. (Wyman, 76). Thus, if a cat’s skull
has a capacity of 25 cc., the brain of the same cat would weigh approximately 26 grams.
Wyman’s statement refers only to the human brain, but presumably the specific gravity of
the cat’s brain is nearly or quite identical with that of man.

§ 565. Obvious Structure of Bone.—lIn life the surface is covered with a dense layer
of connective tissue, the periosteum. Entad of this periosteum is a layer of compact bone.
The intermediate part of all bones is, however, more or less loose in structure, something
like a sponge, hence it is called spongy or cancellated bone. This is especially abundant
toward the end of long bones and in the vertebral centra.

§ 566. Microscopic Structure.—A solid mass containing: A. Haversian canals, cyl-
indrical channels shown as circles in cross section, as cylinders in longitudinal sections

.of long bones, These canals contain the blood vessels, as may be demonstrated by exam-
ining a finely injected cat’s scapula (see Frey, A). They anastomose freely, and open
either upon the ectal surface or within the medullary canal.

B. Lacune and canaliculi. These are the spaces occupied by the protoplasmic bone
cells or corpuscles and their prolongations. They appear in outline like irregularly
fusiform connective tissue corpuscles with many fine prolongations or branches. These
branches anastomose with the branches of neighboring lacunz, and sometimes open into
an Haversian canal.

In transections of long bones the solid matter and lacune are seen to be arranged in
more or less concentric lameliz around the Haversian canals.

CHAPTER VI.

MYOLOGY—THE STUDY OF THE MUSCLES,

GENERAL CONSIDERATIONS—FREQUENCY OF MUSCULAR VARIATIONS—EXPLANATION OF
TECHNICAL TERMS—APHORISMS FOR DISSECTORS—LIST OF INSTRUMENTS AND
MATERIALS—HOW TO USE DISSECTING INSTRUMENTS—PRACTICAL SUGGESTIONS—
CLIPPING THE HAIR-—CUTTING THE SKIN—REMOVAL OF THE SKIN—NAMES AND
SYNONYMS OF THE MUSCLES HEREIN DESCRIBED—DESCRIPTIONS OF FORTY MUSCLES
OF THE CEPHALIC REGION OF THE BODY, WITH DIRECTIONS FOR THEIR DISSEC-
TION—THE STRUCTURE OF MUSCLE,

General References to Myotomy.—Bernard, A, 182-206; Chauveau (Fleming), 184-
186 ; Cleland, A, 1-7 ; Heath (Keen), A, Appendix ; Hodges, A; Hyrtl, A, 59-67 ; Mojsis-
ovics, A, 1-15; Straus-Durckheim, B, 180-162; Reeves, A.

§ 567. Muscular Homologies—The following works and papers deal with the general
and special homologies of muscles ; the first three embrace all Vertebrates and all regions
of the body ; the others refer mainly to the limbs of the Mammalia: Humphrey, E,
105-188 ; Meckel, A, V, VI; Cuvier, A, I; Quain, A, I, 185; Mivart, 4; Macallister, 9,
12,19; Rolleston, 13 ; Krause, A ; Coues, 1, 36,47; Wilder, 1,4, 10, 20.

§ 568. General Considerations.—For the reasons stated in § 201, Practical Anatomy
always begins with the skeleton, including the bones and cartilages, the arthra (joints)
and ligaments.

Of the soft parts, the muscles are most easily prepared, examined and preserved, and
they serve, together with the bones, as landmarks for the recognition of the vessels and
nerves ; hence Myology naturally succeeds Osteology.

Yet the practical study of the muscles is not without its difficulties.

Upon the limbs, excepting the distal segments, the muscles are much more numerous
than the bones. For example, in the arm and shoulder girdle, if we omit the manus,
there are five bones, scapula, clavicle, humerus, ulna and radius. Excluding those which
arise from the humerus and are inserted upon the manus, more than thirty distinct
muscles are attached to these five bones.

The larger bones also are readily recognized, even when covered by soft parts ; but two
or more muscles in the same locality may have the same general form and direction, so
that their determination may involve a careful examination of their attachments.

Hence, whereas most of the bones may be prepared in the sme way, the general rules
for dissection must be modified and supplemented with respect to each muscle, in order
that it may be exposed, dissected, examined and removed to the best advantage.

§ 569. Just how explicit the directions should be has not, apparently, been fully
determined by anatomical teachers and writers. Some “ Laboratory Directions” are so

MUSCULAR VARIATION. 193

meager as to be, according to our experience, of no value whatsoever. Nowhere, in
zootomical works, have we found them so complete as in the “ Dissector’s Guides ” which
are used in the Medical Schools. Yet even these, in our opinion, are not altogether
suited to the needs of the beginner. They are not sufficiently full; all the parts in a
given region are considered at once, a plan better adapted to the advanced student ; finally,
too little attention is given to typographical and paragraphic details which might facili-
tate the recognition of statements and reference to other parts of the work.

Without assuming to have decided correctly in this matter, we have acted upon the
belief that dissection is a fine art, and by no means easy to acquire; that the beginner is
liable to fall into grave errors as to manipulation, fact and interpretation ; and that, upon
the whole, it is better for him to follow even an imperfect method than none at all.

§ 570. Variation.—Another difficulty met with in the study of muscles is the frequency
of variations and anomalies not only as to size and shape, but also as to connections, vas-
cular and nervous supply, and even presence.

All standard works upon Human Anatomy record the existence of such variations, and
it is probable that the careful examination of any human subject would disclose one or
more departures from the condition regarded as normal.

Notwithstanding the intrinsic probability that any other Mammals, at least the domes-
ticated species, would vary in a similar manner, most dissectors of the lower animals seem
to have assumed that what is true of one individual is true of the whole species, and the
myological descriptions of Straus-Durckheim (A), Chauveau (A), Coues (47), and Krause
(A) rarely mention departures from rule. Yet no two anthropoid apes have been found to
agree in all respects, as may appear from the published dissections of Duvernoy (100),
Humphrey (10), Champneys (1), Wyman (47), Macalister (21, 41), Barnard (12), the
senior author (1) and others, and Huxley has distinctly expressed (A, 410) the belief that
“endless varieties will no doubt be met with by those who carry their inquiries farther”
than by the dissection of single individuals of a species; see also the remark of Galton,
1, 175, note 30.

The senior author has remarked upon the existence of individual variations among
domesti:ated dogs (21, 308), and we may add that no one of the scores of cats dissected
by us or our students has failed to present some peculiarity of muscular arrangement.

The records of these variations have not as yet been put into shape for publication, and
in the present descriptions it has seemed better to give, in most cases, only what seems to
be the most usual structure. The student is reminded, however, that his very first dis-
section may disclose some feature hitherto unobserved.

§ 571. Errors of Manipulation.—The beginner should bear in mind that nothing is
more easy than to commit some error of manipulation—whether by a cut too many or a
cut too few—which may greatly affect the appearance of the parts, and lead to very mis-
taken conclusions. As a rule, therefore, supposed anomalies should not be published until
submitted to competent criticism, or carefully checked by the dissection of other individ-
uals, or still better of the other half of the same.

In all cases, the student will do well to recall the advice of Cuvier to a young medical
student who ventured to tell him that he had discovered something very new and remark-
able in a human body. Cuvier replied: “‘ Go and anatomize an insect, the largest you can
find ; then reconsider your observation, and if it appear to be correct, I will believe you
on your word.” After making the dissection, the student confessed that he had been in
error ; (Lee, A, 56).

As has been suggested by the senior author (22, 307), it is doubtful whether any dis-
section by beginners should be published at all, excepting upon the approval of an experi-
enced anatomist, after thorough examination.

13

194 ANATOMICAL TECHNOLOGY.

§ 572. Errors of Interpretation—When an author denies the existence of a part the
presence of which is affirmed by other writers, the discrepancy may be due to either of
five causes :—

1. Its absence is the rule, and its presence in the other cases was exceptional.

2. It was absent, though normally present.

8. It was present, but accidentally overlooked.

4, It was observed but not recognized, or was mistaken for some other part.

5. It was seen, but purposely ignored.

Of course the last named explanation is also the last to be entertained, but either of the
other four contingencies is liable to occur with even experienced dissectors and learned
anatomists.

For example, the M. entopectoralis (Fig. 72), “ pectoralis minor,” is said by Straus-Durck-
heim (A, II, 336), and implied by Meckel (A, VI, 249), and Mivart (B, 145), to be wanting
with the cat; its existence in any Carnivora is also denied by Cuvier (A, I, 370), and A. H.
Young (7,171). Owen, however, speaks (A, III, 50), of the ‘‘ pectoralis minor of the dog,”
and its presence in that animal is admitted by Haughton (115) and Wood (7, 52), as it is
in the cat by the senior author, who refers (20, 306) to it as found in all the Felide and
Canide examined by him.

The muscle considered by the writers last named to represent the “‘ pectoralis minor”
of man is so large in most Carnivora that it was not recognized by the five writers first
pamed as the representative of that rather insignificant muscle; in the bear and skunk,
however, as stated by the senior author in the paper referred to, it is again smaller than
the W. ectopectoralis.

In illustration of the second case, the M. supinator longus (Fig. 74) is said by Meckel
(A, VI, 303), and Huxley (A, 355) to be wanting with the dog. Chauveau, however,
affirms (A, 290) its presence in dogs of all breeds, and it has been repeatedly observed by
the senior author. Hence we may conclude, provisionally at least, that it was exception-
ally absent in the individuals dissected by Meckel and Huxley.

THE TECHNICAL TERMS OF MYOLOGY.

§ 573. Musculus—Muscle.—The name for a mass of muscular

fibers. Such amuscle may or may not be a true muscular integer.

What constitutes a muscular integer has not been determined ; as stated in the senior
author’s brief discussion of the subject (10, 68), the phrase “ morphological integer”
seems to have been first used with reference to the muscles by Coues (1, 223), but the gen-
eral question is discussed, directly or indirectly, by Owen, Parker, Spencer, and more
recently, Humphrey (E). In the present work, it has seemed best to us to recognize as
separate muscles, or as distinct divisions of muscles, all the muscular masses whose origins
and insertions are fairly constant and capable of definite description.

In applying separate names to the divisions of the human trapezius (Fig. 66, § 607),
and deltoideus (Fig. 66, § 674), and yet treating the Jong and short heads of the coracoideus
(Fig. 75, § 668), as a single muscle, we are certainly open to the charge of inconsistency.
In the present transitional state of opinion respecting muscular integers, entire consis-
tency is hardly to be expected.

§ 574. Muscular Groups.—It is sometimes convenient to speak
of two or more muscles collectively as a group, as, é. g., the pecto-
ralis group, the trapezius group, the triceps group.

PARTS OF A MUSCLE. 195

§ 575. Subdivisions—As has been well stated by Humphrey
(E, 110), the longitudinal subdivision of a muscle may be either
vertical or horizontal. For the sake of distinctness, we shall call
the subdivisions of the former kind divisiones, and those of the lat-
ter amine. For example, as has been remarked by the senior
author (20, 306), the ‘‘ If. ectopectoralis (Fig. 72) tends to separate
into superimposed laminz, while the entopectoralis tends to form
fasciculi”’ In the former the “cleavage”’ is horizontal, in. the lat-
ter vertical.

§ 576. Parts of a Muscle.—The essential and usually largest
portion of a muscle is the mass of muscular fibers ; this is called its
body or belly.

Sometimes one—rarely if ever both—of the ends of a muscle is
attached to bone directly or rather to its periosteum. This is the
case with the humeral end of the IZ. brachialis (Fig. 74, § 692), and
the IL entotriceps, div. intermedia (Fig. 75, § 686).

More often, however, there intervenes between the muscular por-
tion and the bone a cord or sheet of white inelastic.fibrous tissue,
constituting the tendon. The attachment is then said to be tendi-
nous, while in the former case it was muscular.

Tendons may be so short as to be hardly distinguishable, like
' the coracoid tendon of the Jf. coracoideus (§ 668), or they may be
longer than the muscular portion, like the humeral tendon of the
same muscle (Fig. 75).

Sometimes, especially with thin flat muscles like the laminz of
the JL. ectopectoralis (Fig. 72), the tendinous sheet may be SO short
as to be practically absent.

§ 577. Attachment Lines and Areas. aiatthe attachments
usually, and tendinous attachments sometimes, cover considerable
areas (brachialis, Fig. 68); in other cases the attachment is along
lines (entopectoralis, divisio caudalis, Fig. 69).

§ 578. Origin and Insertion.—Of the two attachments of a mus-
cle, one is called origin and the other insertion. Usually, but not
always, the origin is from the more fixed part of the body, and the
insertion is upon the more movable part.

§ 579. Choice of Origin and Insertion.—With the membral
muscles, one attachment is generally nearer the soma (§ 54) or the
proximal end of the limb, and this attachment is always called the
origin. Thus the scapular attachments of the IZM. biceps (Fig. 75)
and subscapularis (Fig. 73) are the origins of those muscles ; so

196 ANATOMICAL TECHNOLOGY.

also, the origins of the WM. entopectoralis (Fig. 72) and clavo-
trapezius (Fig. 66) are, respectively, their sternal and vertebral
attachments.

But the question is less easy with some muscles which connect different parts of the
soma with each other, or which extend between the head and the scapula, clavicle or
sternum.

Without feeling sure as to what is best, we have adopted the following basis :—

As between the head and the neck or the trunk, the latter are more central and afford
origin to the muscles of the head.

The sternum is part of the trunk, and sternal attachments are therefore origins.

The scapula and clavicle appertain to the arm rather than to the trunk, and attachments
thereto, as compared with attachments to the head or neck or trunk, are insertions.

It will be seen that the acceptance of these rules entails some apparent contradictions:
For example, the clavo-mastoideus (Fig. 67), like the clavo-trapezius (Fig. 66), arises
from the skull and is inserted upon the clavicle; but the sterno-mastoideus (Fig. 67),
like the splenius (Fig. 67), arises from the trunk and is inserted upon the skull.

Hence the origin of the clavo-mastoideus practically coincides with the insertion of
the sterno-mastoideus. In man, where the clavicle joins the sternum, the two muscles
are commonly described as one, under the name of sterno-cleido-mastoideus, and one
part of the muscle therefore arises where the other is inserted, and vice versa.

§ 580. The Determination of Muscular Homologies.—Of course
the function of a muscle depends upon its insertion, but there is
considerable difference of opinion as to whether the origin or the
insertion is the better guide to the determination of its homology.
We are disposed to assign greater morphical importance to the ori-
gin, according to the views of Barnard (7, 114). As to the value of
vascular and nervous supply, see Cunningham (2) and Gadow (3).

§ 581. Fascia.—This is simply a thin sheet of the same kind of
fibers as the tendon, but the fibers may present two kinds of ar-
rangement. Sometimes the tendon itself is so thin as to be called a
fascia, or it may be continued as a thin sheet upon one or the other
face of the muscle ; in both these cases, the fibers are nearly or quite
parallel. The name fascia, however, is more often given to a sheet
of fibers crossing one another in various directions, and forming a
sheath or covering fora muscle or a group of muscles. A fascia is
also called an aponeurosis, but the name is objectionable on account
of both length and etymology.

§ 582. Forms of Muscles.—The body of a muscle may be /wsi-
form or spindle-shaped, like that of the WZ. biceps (Fig. 73); teni-
ate (strap-shaped or ribbon-like), as with the occipito-scapularis
(Fig. 67) ; fan-shaped like the subscapularis (Fig. 73); quadri-

APHORISMS FOR DISSECTORS. - 197

lateral like the acromio-trapezius, or triangular like the spino-tra-
pezius (Fig. 66). There are other and less usual forms which will
be indicated in special cases.

§ 583. Designation of the Borders of Muscles.—Many of the
muscles are thin and triangular or teniate, so as to present sharply
defined borders, in place of the more or less rounded aspects or sur-
Faces of a fusiform muscle like the biceps.

Such a flat muscle may become twisted upon its axis in such a
way as to change the relations of the borders to the body-planes.
In these cases, for the sake of convenience, it will be considered that
the muscle has the general direction which it had at its origin, al-
though this may sometimes involve an apparent contradiction of the
terms in which the insertion is described.

For example, the JZ. pecto-antebrachialis, dv. cephalica (Fig.
72), arises at the meson, and its borders are called cephalic and
caudal throughout its whole length, notwithstanding the fact that
the line of insertion upon the ulna has a proximo-distal direction, so
that, as based thereon, the borders would be proximal and distal.

§ 584. Connect.—For the exposure of the ectal layer of muscles,
certain areas of skin must be lifted. The lines of incision which
circumscribe such areas are said to ‘“‘ connect’? certain parts or

points, usually some of the ‘‘ landmarks” elsewhere (§§ 225-233)
enumerated.

§ 585. Girdle.—When the skin, especially of a limb, is divided
by an incision encircling the part, the latter is said to be ‘‘ girdled.”
§ 586. Transect.—In order to examine fully the attachments of
a muscle, it is usually desirable to divide it transversely and reflect
the two ends in opposite directions. For the sake of brevity, this

entire operation will be indicated by the use of the single word
transect.

APHORISMS FOR DISSECTORS.

§ 587. 1. ‘* Without skilful manipulation we can neither teach
by demonstration facts which have been already discovered, nor
hope to extend the limits of observation and experimental knowl-
edge.’’—L. 8. Beale, A

2. “A piece of true dissection ought to turn out an object of
wonder and beauty.’’—Goodsir, A, I, 24.

3. ‘* An anatomist therefore in these curious things had need to
have a fine and dainty hand, and at command.’’—Crooke, A, 460.

198 ANATOMICAL TECHNOLOGY.

4, ‘**The best workman uses the best tools.’’—Owen.

5. The value of instruments depends not upon their handles,
their finish or their cost, but upon the adaptation of their size, form
and temper to the work in hand.

6. Fingers are often the best forceps.

7. Handling and cutting are necessary evils.

8. Neglect of the knife may leave the truth concealed ; its misuse
may establish an error.

9. ‘‘Let the eye go before the hand, and the mind before the
eye.”’—O. W. Holmes.

10. Fat is the anatomist’s worst enemy.

11. ‘‘ Drying is even worse than decomposing.’ —R. M. Hodges.

12. The skin makes the best wrapper.

13. There are two sides, but only one meson.

14. The bones are the guides to the muscles, the muscles to the
vessels, and the vessels to the nerves.

15. The attachments of a muscle determine its homology and
function; the thickness and length of its body indicate respectively
its power and the distance through which it may contract.

16. The attachments of a muscle are often closely associated
with those of others, but its body is usually distinct.

17. In dissecting muscles, the science consists in discriminating
between fascia or tendon and mere connective tissue; the a7t, in
removing the latter so as to leave the muscles distinct.

18. Dissection according to direction favors the acquisition of
methods and the learning of names and specified relations ; but the
knowledge of parts is not complete until they have been approached
and examined from all sides. See also § 122.

§ 588. List of Instruments and Materials for the Dissection
of Muscles.—Arthrotome, Fig. 16, § 135; blocks, § 1387; coarse
forceps, Fig. 18, 145 ; fine forceps, Fig. 20, § 146; scalpels, medium
and Charriére, Fig. 23, 24, § 155; coarse scissors, curved flatwise,
Fig. 25, § 156; hair scissors, § 158; towels, § 165; sharp tracer, Fig.
17, § 166; tray, § 167; waste pail, § 195; waste papers, § 172;
wetting bottle, Fig. 27, § 170.

§ 589. The Material for Dissection —A lean animal should be
preferred ; it should be divided by abdominal transection (§ 234) ;
injected with alcohol (§ 285), but not—for the first dissection—with
plaster ; kept in 42-55 per cent. alcohol (§ 286), and not allowed to dry.

USE OF THE SCALPEL. 199

HOW TO USE DISSECTING INSTRUMENTS.

§ 590. Hyrtl complains (A, 62) that ‘‘some people hold the for-
ceps like fire-tongs, and the scalpel like a cheese-knife.”’ It is true
that most anatomical instruments are for either grasping or cutting,
but their proper and successful employment demands much more
care and delicacy than is needed in ordinary household operations.
The good whittler is not necessarily an expert dissector, and even
the coarse scissors are to be handled very differently from shears.

The anatomist, like the surgeon—who is an anatomist and some-
thing more,—should have such command over his muscles and
nerves that whatever instrument is in his hands becomes for the
time being like a part of himself, an extension of his fingers, sharper,
firmer and more slender, yet almost equally mobile and sensitive.

Fic. 63.—THE ScALPEL HELD As A PEN. (From Bernard).

§ 591. Use of the Scalpel (§ 155).—The scalpel may be held in
either of three general ways :—

A. Like a Pen (Fig. 63).—The edge is directed backward and
downward, or forward and upward. This is for ordinary dissection.

B. Like a Carving-knife (Fig. 64).—The edge may be directed
upward or downward. This is for the division of more resisting
tissues.

C. Like a Violin-bow (Fig. 65).—The scalpel is held between the
tip of the pollex on one side and the tips of the other digits upon the

200 ANATOMICAL TECHNOLOGY.

other. This is for long sweeping strokes, where the greatest freedom
is desired.

Minor modifications of these three ways will be readily adopted
as the dissector becomes familiar with the instrument.

Fic. 64—THE SCALPEL HELD AS A CARVING-KNIFE, (From Bernard).

§ 592. Use of the Scissors (§ 156).—Contrary to the more usual
custom, dissecting scissors should be held with the pollex and me-
dius. The index then serves both to steady the instrument and to

‘Fie. 65.—THE ScaALPEL HELD As A VIOLIN-BOW. (From Bernard).

aid the medius in its opposition to the more powerful pollex. In
nearly all cases the points of curved scissors should be turned wpward
and away from the part under dissection. This precaution is es-

THE USE OF INSTRUMENTS. 201

pecially needful in the trimming of vessels and nerves and inflated
hollow viscera (§ 331).

§ 593. Use of the Forceps (§ 145).—The forceps are commonly
held between the pollex and the index. In long continued dissec-
tions the medius may be substituted for the index at intervals. The
digits should be employed in place of the forceps when practicable,
both as a relief from fatigue and to avoid crushing the tissues.

The forceps should be used upon muscles as little as possible,
and vessels and nerves should be grasped by their sheath of con-
nective tissue. For the separation of slender muscles and of vessels
and nerves, the safest way sometimes is to insert the tip of the closed
forceps and then allow the blades to separate gently.

§ 594. Use of the Tracer (§ 166).—The tracer is to be held like
a pen or pencil. Its form permits a rotation on its axis, so that the
point may have any desired direction.

The tracer should be more constantly in the hand than any other
instrument. Scalpels and other sharp instruments should only be
used when the tracer will not answer the purpose.

The tracer is also very useful in detecting the position of con-
cealed hard parts, as ribs, cartilages and vertebre. The point may
be introduced deeply without impairing the condition of the parts for
dissection, and the curvature enables one to lift upon it the ribs or
cartilages so as to count them more accurately.

§ 595. Use of the Arthrotome (§ 135).—As its name implies,
the distinctive use of this instrument is for the division of joints and
other rough operations which might injure the more delicate edge
of the scalpels. Yet the student should accustom himself to accu-
rate and careful manipulation, and endeavor to separate the contig-
uous bones at an arthron without injuring the cartilages. He
should try to feel with the point of the instrument.

PRACTICAL SUGGESTIONS FOR DISSECTORS.

§ 596. 1. Select a lean animal for all anatomical purposes, and
especially for the dissection of the muscles, vessels and nerves. The
directions for killing are given in § 192.

2. Take the precautions for cleanliness which are described in
8 199.

3. Remove superfluous parts of the animal, the tail in some cases
($ 243), the caudal or cephalic region of the body, according to the

202 ANATOMICAL TECHNOLOGY.

directions for abdominal and thoracic transection which are given
in $$ 237, 242.

4. See that all the instruments, materials and books for dissec-
tion, reference and record are at hand and in order before getting
the subject or beginning to work.

5. Refer constantly to a skeleton, or to the bones especially con-
cerned, or to accurate figures.

6. When possible, the head of the subject should be toward
the left.

7. When a part from which or toward which an incision is to be
carried lies upon the meson, the incision should extend 1-2 cm.
beyond the meson. This permits the flap of skin to be reflected
across the meson to that extent. If, however, this flap of skin is to
be removed, the incision removing it should run parallel with the
meson, and upon the side under examination.

Objections to Mesal Incisions.—Both the ectal and ental aspects of the skin present spe-
cial features at some mesal points, and several muscles besides those of the skin itself arise

at the meson, and are liable to injury by a mesal incision. There are two sides, presuma-
bly similar, but there is only one meson.

8. Incisions should be as long as may be consistently with the
shape and structure of the parts, and the dissector’s knowledge of
them.

9. When important or delicate parts are liable to be injured, the
cuts should be shorter and more carefully made.

10. Vessels and nerves should be dissected from the center
toward the periphery, so as to avoid the risk of missing, cutting or
tearing the branches.

11. Vessels injected with plaster should be divided with the
arthrotome or the bone scissors.

12. In place of the block, especially while the separated arm is
under dissection, a folded wet towel may be used; this permits a
kind of bed to be made which keeps the arm in place.

13. “To put any group of muscles on the stretch, put the parts
concerned in the position into which they would be brought by
their antagonistic muscles. For example, to put the flexors of the
manus on the stretch, put the manus in a state of extension, and
vice versa.’ —Heath (Keen), A, 16.

14. Study the actions of a muscle by pulling it in the line it nat-
urally occupies. Note the difference between a direct and an indi-
rect action. (Wilder, 4.)

SUGGESTIONS FOR DISSECTORS. 203

15. As arule, muscles must be divided and reflected before the
attachments can be fully determined. The attachments are usually
more distinct upon the ental aspect.

16. ‘‘ When several similar muscles of a group—as those upon
the antebrachium—are to be transected, cut them at different levels,
so as the more easily to match their proximal and distal parts.’’—
Heath (Keen), A, 16.

17. The borders of a thin muscle should be grasped and slightly
raised, first with the forceps and then with the fingers. If the other
border is accessible, it should be treated in the same way, and then
the entire width at about the middle raised to permit the passage
of a scalpel.

18. In transecting a wide muscle, cut one border, then lift it,
keeping the sides of the cut separate, and cut a little deeper,
applying the scalpel to the edge of the muscle.

19. Avoid cutting muscles at theirattachments. If it is desirable
to remove part of a large muscle, leave a small piece of the body
attached to each tendon. If necessary—for special reasons—to re-
move an entire muscle, insert the edge of the arthrotome in the angle
formed by the attached ends and the bones.

20. Parts under dissection should be wet occasionally with a
mixture of water, glycerin and clove-oil (§ 170).

21. Parts which have been exposed, but are no longer under
actual dissection, should be covered with skin or rubber-sheeting,
or with a bit of cloth wet with the glycerin mixture; and a dry
towel should be laid over all.

22. “ Put all fragments on a piece of paper.’’—Hodges, A.

§ 597. Avoid especially the following: drying, tailing, pecking.

The prevention of drying has been already considered.

Tailing is the making of a shallow cut at the beginning or the
end of an incision. It is especially apt to occur with beginners,
and while dividing the skin. To avoid it, hold the point of the scal-
pel perpendicularly to the surface at both the beginning and the
end of the incision.

Pecking.—We use this homely word to designate one of the
most common and most pernicious faults of anatomical beginners,
the habit of aimlessly poking and pinching the parts, espe-
cially while showing them to the teacher or demonstrator. It
reminds the observer of nothing so much as the dabbing and peck-
ing which hens inflict upon a piece of meat. The student should

204 ANATOMICAL TECHNOLOGY.

bear in mind that a single false cut, and even a pinch in the wrong
place, may mar his work beyond repair; he should exercise con-
stant self-control, and never touch the specimen excepting for a
definite and sufficient reason.

Pecking is only one of several forms of what may be called
anatomical .Philistinism; a lack of appreciation of delicacy,
whether in structure or in methods of manipulation.

§ 598. Clipping the Hair.—Unless the skin is to be preserved,
or there is some other objection, the hair should be removed from
a specimen which is to be preserved in alcohol and dissected at
intervals.

If the hair is allowed to remain, it interferes with the accuracy of dermal incisions, and
with the ease of making them ; it is apt to become detached and disfigure the dissections :
finally, unless considerable time is spent in squeezing out the alcohol when the specimen
is removed from the jar and the water when it is returned thereto, the hair causes both a
waste and a weakening of the alcohol in which the specimen is preserved.

Use the hair scissors (§ 158) or a pair of ordinary scissors with
the points blunted. The hair is more easily cut against its inclina-
tion, that is, with the scissor points directed cephalad upon the
soma and proximad upon the limbs. After abdominal transection,
begin at the cut border of the skin.

Clipping is facilitated by wetting the tips of the hair with a
sponge only moderately full of water or weak alcohol. Cut close
to the skin. The operation usually occupies about an hour. Do
not put the removed hair into the sink. Place it in the waste-pail,
to be buried.

§ 599. Cutting the Skin.—If the hair remains, wet it with 15
per cent. glycerin, or dilute alcohol, or water, along the line of the
proposed incision. Then, with a small comb, or the tracer, or the
handle of a scalpel, part the hair evenly along the same line so as
to expose the skin clearly (§ 354). If the hair has been removed,
indicate the line of incision by a scratch made with the tracer or the
point of the scalpel.

Place the tips of the left index and medius, one upon each side
of this line, at the cut border of the skin, and divaricate them so as
to stretch the intervening skin.

Grasp the scalpel like a pen, at an angle of 45°, and divide the
skin by a single steady stroke as far as the tension exists.

At the beginning and end of the stroke, make the scalpel nearly
perpendicular so as to avoid tailing (§ 597).

REMOVING THE SKIN. 205

Unless one is quite familiar with both the locality and the art of
dissecting, this first incision should merely divide the skin proper.
The borders may be still farther divaricated, and a similar incision
made through the connective tissue and fat, and in some cases the
dermal muscle (§ 629), until the darker red and closer texture
shows that the ordinary skeletal muscles have been reached.

With lean animals this second incision will be very shallow, but
in some cases the fat forms thick layers between the dermal mus-
cles and the skin and deeper muscles. On the cheeks of old males,
and sometimes on other regions, the skin and connective tissue are
so thick as to puzzle the beginner.

Shift the tips of the index and medius, and repeat the operation
to the end of the line. The separate strokes should join each other
accurately, so that the entire incision is straight and smooth-edged.

After the skin is divided, the subcutaneous fat and connective
tissue may usually be cut to the proper depth by a single long
steady stroke.

§ 600. Removing the Skin.—The edge of the area of skin to be
removed, preferably at the angle formed by two incisions, should be
grasped, first by the forceps and then by the fingers, and lifted so
that the scalpel may be applied to the connective tissue by which it
and the fat are held loosely to the deeper muscles.

Excepting in the case of some rare form (which should not be
dissected by a beginner), the skin should be kept well upon the
stretch, and the edge of the scalpel should be applied against the
tissues to be exposed, following the direction of the muscular fibers.
The object is to remove with the skin all the subcutaneous fat, con-
nective tissue and ectal fascia, so as to expose at once and fully the
surface of the muscles, etc., to be examined.

This, the anatomical method of removing the skin, is more diffi-
cult than the ‘‘ flaying’”’ of the butcher or the ‘‘skinning”’ of the
taxidermist. Both of these desire the skin free of fat and connective
tissue, and therefore keep the edge of the knife turned toward it.
The taxidermist must avoid stretching, but this is easier than to
follow strictly the above method. The beginner will usually be
tempted to get the skin off in the easiest and quickest way, which
is that of the butcher; but he then is obliged practically to repeat
the operation for the removal of the tissues which should have
been lifted with the skin.

§ 601. Rigor Mortis.—The spontaneous stiffening of the mus-

206 ANATOMICAL TECHNOLOGY.

cles which supervenes soon after death renders dissection difficult.
The condition usually passes off within a few hours, and may be:
speedily overcome by immersing the animal for 40-60 minutes in
water at about 35° C. (95° F.).

DESCRIPTIONS OF CERTAIN MUSCLES.

§ 602. Limitation.—For the reasons stated in § 128, the myological portion of this
work directly relates to only about one fifth of the whole number of muscles which have
been enumerated in the cat. As with the bones, however, (§ 368), the student is advised
to pursue the subject further, making original drawings and descriptions of at least one
muscle in another part of the body. Whether it can be at once identified with some mus-
cle in man is of less importance, so far as the training of the pupil is concerned, than the
accurate determination of its connections and other characters,

§ 603. The Method here Followed.—With few exceptions, each of the forty muscles
here considered is described under the following heads :—

1. Synonymy.—We have given the names for the same muscle employed by Straus-
Durckheim and Mivart, and the names for what appears to us to be the homologous mus-
cle in man and in the horse. The anthropotomical names are taken from ‘‘ Gray” and
“ Quain,” and the hippotomical ones from the French and the English (Fleming’s) editions
of “ Chauveau.” In some cases, we have been unable to satisfy ourselves as to the homol-
ogy. We should have been glad to include references to the works of Leyh (A) and
Gurlt (A) upon the horse, to Krause’s Anatomy of the rabbit (A), and to Coues’s paper on
the opossum (47). The authors’ names are indicated by the initial letters only.

2. Figures.—Here are enumerated the figures wherein the muscle appears.

8. General Description.—This is a brief indication of the general form and connections,

4, Postwre.—We have indicated. the position of the body or limb which seems most
favorable to the examination of the muscle.

5. Hxposwre.—Here are given directions for bringing the muscle into view by the
removal of the skin or overlying parts.

6. Dissection.—This includes the operations by which the borders of the muscle are to
be raised, its body transected and the ends reflected so as to display the attachments.

7 and 8. Origin and insertion.—Here are given more detailed descriptions of the two
attachments.

In addition to the above, a complete account of each muscle should embrace its nervous
and vascular supply, its actions, direct, indirect and associated, and its variations.

Errors and Defects.—During the past four years the descriptions and directions here
given have been employed by the students in the anatomical laboratory of Cornell Univer-
sity. Inasmuch, however, as annual modifications have been found necessary, we cannot
hope that their present form is altogether what it should be, and we shall be very grate-
ful for the correction of errors and the pointing out of defects.

We desire here to repeat the expression of our sense of obligation to Prof. T. B.
Stowell, who has kindly followed the descriptions and directions scalpel in hand, and has
given us the benefit of many valuable suggestions and criticisms as to both the facts and
the method of stating them, and as to the extent of variation in different individuals.

A former special student, Dr. E. M. Howard, generously placed at our disposal for
comparison his manuscript descriptions of the muscles of the cat.

§ 604. The Names of the Muscles.—The number, extent and nature of the changes
proposed in the names of the muscles are set forth in the Table on p. 207.

In that Table the names in the left hand column are those adopted in the present work ;

TABLE OF THE MUSCLES.

207

those in the right hand column are Latinized from those employed by Straus-Durckheim ;
those in the middle column occur in standard works upon Human Anatomy, or in the

writings of anthropotomists.

In the last column are words or abbreviations indicating

the changes which have been made in the names employed by Straus-Durck heim (§.-D.)

or anthropotomists (anth.) :

thus, abbrev. =

abbreviated ;

tr’l’d = translated; unif. =

unified.
§ 605. TABLE,

Here Adopted. Fig. Anthropotomy. | Straus-Durckheim. Changes.
Spino-trapezius.....| 66 Trapezius (in pares | Dorso-cucullaris ....| S.-D., unif, & tr’l’d.
Acromio-trapezius ..| 66 | | Acromio- cucullaris, .| 3. -D., translated.
Clavo-trapezius..... 66 ns < | Clavo-cucullaris. . .| 8.-D., transiated.
Occipito-scapularis...| 67 | Rhomboideus capitis Occipito- scapularis. 8.-D.
Rhomboideus...... 67 | Rhomboideus major Rhomboideus...... 8.-D.: anth., abbrev.
Sterno-mastoideus..| 67 ; per mcoe pet | Sterno-mastoideus. ./ 8. D. & anth.

‘Clavo-mastoideus...| 67 i sxe annie Cleido-mastoideus..| S. D,, translated. ‘
Levator clavicule...| 67 | Levator clavicule...| Transv.-scapularis ..! Anth.
Dermo-humeralis...| 66 | ..............045- Dermo-humeralis. ..| 8.-D.
Latissimus......... 67 | Latissimus dorsi....| Latissimus dorsi....| 8.D.; anth., abbrev.
Clavo-deltoideus....| 66 | Deltoideus (in part).| Delto-clavicularis. ..| 8.-D., transposed.
Pecto-antebrachialis,| 72 | ...........e.caees Pecto-antebrachialis | 8. D.
Ectopectoralis...... 72 | Pectoralis major....| Large pectoral...... Generalized.
Grand pect. (in
Entopectoralis...... 72 | Pectoralis minor....| + part) and sterno-} | Generalized.
trochiterianus..
Xiphichumeralis../(°7Os ck oss Pea eet Grand pect. (in part).| New.
Serratus magnus ...| 73 | Serratus magnus...) Serr. mag. (in part).| Anth. and 8.-D.
gpa . Ha pas t 73 | Lev. ang. scap...... £6 a ..| Anth.
Coracoideus........ 75 | Coracoideus........ Coraco-brachialis...| Anth., abbrev.; 8.-D.
Subscapularis...... 73 | Subscapularis......| Subscapularis...... Anth. & 8.-D.
Supraspinatus...... 67 | Supraspinatus...... Supraspinatus......| Anth. & 8.-D.
Spino-deltoideus. ..| 67 Deltoideus (in bidet Delto spinalis...... 8.-D., transposed.
Acromio-deltoideus,.| 67 | Delto-acromialis....| 8.-D., transposed.
Infraspinatus. ..... 67 | Infraspinatus....... Infraspinatus...... Anth. & §.-D.
Micostalis.......... 74 | Teres minor........ Micostalis.......... 8.-D.
GRO SOG cco sae 75 | Teres major.. A MORODE Fh bik eee ale 8.-D.; anth., abbrev.
Epitrochlearis...... 75 | Dorso- epitrochlearis | Triceps (in part)....| Anth., abbrey.
Meditriceps........ 74 | Triceps (in part)... .! | Triceps medius..... §.-D., abbrev.
Kctotriceps........-. 74 rs " Triceps externus.... Generalized.
rice (in part) Tri. int. (in part)

Entotriceps........ 75 } pa x rst eae aia Aa Om t 8.-D., abbrev.
Supinator longus...| 74 | Supinator longus. ..! Supinator longus...| Anth. & S$ -D.
DIGEDR acten coin soles Th) Bicsbe) dese: ee HSICOPS 2s ae> os ole = ols Anth. & §.-D.
exer B aes 5 ..| 74 Pech rophe anticus...| Brachialis......... 8.-D.; anth., abbrev.

xtensor (carpi xX. carpi rad. Ma :

radialis ionotey; t 75 ; inane AS t Radialis primus....| Anth., abbrev.
Extensor (carpi Ex. carpi rad. ee

radialis Pas ng 75 ; hievi sa ees Radialis secundus...| Anth , abbrev.
Extensor communis.| 74 | Ex. digitorumcom..| Ex. dig. communis. .| Anth., abbrev.
Extensor minimi...} 74 | Ex. minimidigiti ..| Ex. proprius minimi| Anth , abbrev.
Extensor ulnaris...| 74 | Ex. carpi ulnaris....; Cubitalis........... Anth., abbrey.
DIORTONIIE 5 eerxeals «ol Px ..| Extensor indicis....| Indicator.......... 8.-D.
Pronator teres...... 75 | Pr. radii teres...... Pronator teres...... S.-D.; anth., abbrev.
Flexor radialis ....| 75 | Flx. carpi radialis..| Cercialis.. ........ Anth., abbrey.

208 ANATOMICAL TECHNOLOGY.

Where more than one name is used in Human Anatomy, the shortest is here given;
the coracoideus, for example, is often called coraco-brachialis, and the sterno-mastoideus,
sterno-cleido-mastoideus.

The occipito-scapularis, lecator clavicule and dorso-epitrochlearis occur in man only as
anomalies, and have received names in addition to those here selected.

The names employed by Straus-Durckheim have been put into their classical and tech-
nical form, excepting in the case of the “large pectoral” and ‘‘ grand pectoral.” It is
probable that one cause of the slight use made of the names of this eminent anatomist is
the fact that he chose to publish them in the vernacular form.

§ 606. The Sources of the Names Here Used.—Of the names of the 40 muscles here
described, seven are employed both by Straus-Durckheim and in the standard works upon
Human Anatomy; these are: sterno-mastoideus, serratus magnus, subscapularis, supraspi-
natus, infraspinatus, biceps, and supinator longus.

The following three names have been applied in Human Anatomy, but are not used by
Straus-Durckheim : levator clavicwa, levator anguli scapule, and coracoideus.

The following nine names are used by Straus-Durckheim, but not by anthropotomists :
occipito-scapularis, rhomboideus, micostalis, teres, brachialis, indicator, pronator teres, dermo-
Aumeralis, and pecto-antebrachialis. The last two refer to muscles which do not exist in
man, and four of the others are but slight modifications of the anthropotomical names.

The following eight names are abbreviations of the anthropotomical names : latissimus,
epitrochlearis, extensor radialis longior, ex. rad. brevior, ex. communis, ex. ulnaris, ex.
minimi, and flexor radialis.

The following seven names are translations or transpositions of those used by Straus-
Durckheim : acromio-trapezius, clavo-trapezius, spino-deltoideus, acromio-deltoideus, clavo-
deltoideus, clavo-mastoideus, and meditriceps. As to the hybrid nature of some of these
terms, see § 53.

The following four names are the names in common use modified after the analogy of
the now almost universally adopted ectogluteus : ectopectoralis, entopectoralis, ectotriceps,
entotriceps.

Two names remain to be accounted for. One of these, spino-trapezius, was substituted
for Straus-Durckheim’s dorso-cucullaris for the sake of uniformity with respect to the
other divisions of the human trapezius, and the correlative division of the deltoideus.

This leaves us responsible for but one entirely new name, ziphi-humeralis. While the
muscle so designated seems to us sufficiently distinct to demand a separate appellation, we
are not particularly pleased with the name, and stand ready either to accept a shorter one
or to regard the muscle as only a division of the ectopectoralis or entopectoralis when the
proper evidence is forthcoming.

THE TRAPEZIUS GROUP.

§ 607. General Remark.—The human M. trapezius, a single muscle, seems to be rep-
resented in the cat by three nearly distinct muscles, which are here called—beginning
with the most caudal—spino-trapezius. acromio-trapezius, and clavo-trapezius. They extend
from the cervical and thoracic dorsimeson to the scapula and clavicle.

The names of all the muscles are in italics. To avoid frequent repetitions, the capital
M, the initial of Musewlus, will be prefixed only when otherwise there might be some risk
of misunderstanding.

§ 608. Explanation of Fig. 66.—The left ectal skeletal muscles
_ of the neck and shoulder.

-

THE TRAPEZIUS GROUP. 209

Preparation.—A subtriangular flap of skin was lifted as di-
rected in § 610, together with the dermal muscles connected there-
with. The flap was reflected dorsad, but is omitted from the figure ;
the reflected dorsal end of the dermal muscle called swpra-cervico-
cutaneus, however, is shown. Both cut edges of the skin were
lifted and retracted or reflected slightly.

The dermo-humeralis (§ 629) was mostly removed with the skin,
but its brachial end appears just dorsad of the elbow. The fat and
connective tissue have been removed so as to leave the borders of
the muscles more distinct. From the hiatus trapezii, just dorsad
of the convexity of the shoulder, the fat has been removed so as to
expose the lymphatic gland (Gl. lymphatica), and the hiatus itself
was extended dorsad so as to expose the ventral or lateral margin
of the occipito-scapularis.

In this and the other descriptions of the myological figures, the parts are enumerated
under three heads: bones, etc, ; muscles ; vessels, nerves, glands, etc.

Bones.—Clavicula—Collar bone (§ 422).—In this figure the bone itself does not appear,
but the position of its mesal or sternal end is indicated by the dotted line from the word
clavicula ; see rhaphé.

Mesoscapula—Spine of the scapula (§ 390),—The position of this ridge of the scapula,
intervening between the MM. acromio-trapezius and spino-deltoideus, is approximately
indicated by the name. It is more distinctly shown in Fig. 67.

Metacromion (§ 396).—This process of the glenoid end of the mesoscapula may be felt
through the muscles at a point corresponding with the beginning of its name.

Fascia.—This strip of fascia—hardly deserving the name of ligament— passes from the
lateral or scapular end of the clavicle to the surface of the M. supraspinatus, as better
shown in Fig. 67.

Rhaphé (trapezio-deltoidea) (§ 616).—This line or seam of connective tissue, betwee
the WM. clavo-deltoideus and the MW. clavo-trapezius and clavo-mastoideus (Fig. 67), coin-
cides nearly with the position of the clavicle. It is usually more distinct upon the ental
aspect, and is somewhat exaggerated in the figure. The word is sometimes spelled raphé.

Spine neurales vertebr. (vertebrarum) thoraci. (thoracicorum),—The third and thirteenth
thoracic (‘‘ dorsal”) neural spines (Fig. 30).—The spines themselves do not appear, but the
numbers 3 and 13 indicate the positions of the third and the last of the series.

Muscles.—In the figure the name of each muscle is preceded by M., the initial of
Museulus.

Acromio-deltoideus —The acromial portion of the deltoid (§ 670).—This is the interme-
diate one of the three muscles which, in the cat, seem to represent the single deltoid
muscle of man, It and the spino-deltoideus are inserted, like the human deltoid, upon
the humerus; but the third portion, the clavo-deltoideus (the ‘‘delto-claviculaire” of
Straus-Durckheim) is associated with the brachialis and inserted upon the ulna.

Acromio-trapezius—The acromial portion of the human trapezius (§ 613).—This is the
intermediate one of the three muscles which, in the cat, appear to us to represent the
human trapezius (§ 607). In the figure the name is written obliquely across the scapular
end of the muscle; the word tendon, near its vertebral end, indfeates the imperfectly

14

210 ANATOMICAL TECHNOLOGY.

defined tendon of origin (§ 614). Upon the muscle are also written the names W. occipito.
scapularis, hiatus trapezii, and Gl. lymphatica.

Cervico-auricularis (§ 615).—This muscle of the ear is shown at the dorsimeson between
the ear and the M. supra-cervico-cutaneus ; its name is omitted.

Clavo-deltoideus (§ 637).—See also aeromio-deltoideus.

Olavo-trapezius (§ 615)—See also acromio-trapezius.

Dermo-humeralis (§ 629).—Most of this dermal muscle was removed with the skin; the
name is written across the brachial end which passes between the MW. triceps and Jatissi-
mus to be attached to the latter and the bicipital arch.

Latissimus (§ 635).—This is more commonly called datissimus dorsi. Its caudal por-
tion is covered by the skin ; its dorso-cephalic angle is overlapped by the spino-trapezius,
but exposed in Fig. 67.

Levator clavicule (§ 627).—The scapular end is seen to emerge from entad of the clavo-
trapezius, to partly overlap the acromio-trapezius and to be inserted upon the imperfectly
defined metacromion rather than upon the clavicle, as might be supposed from the name.

Occipito-scapularis (§ 617).—This is fully shown in Fig. 67. Here, its lateral border
appears at the dorsal end of the hiatus trapezii which has been enlarged so as to show the
position of the muscle.

Spino-deltoideus (§ 674).—See also the acromio-deltoideus.

Spino-trapezius (§ 611).—See the acromio-trapezius.

Sterno-mastoideus (§ 622).—Part of this shows darkly between the skin of the neck and
the clavo-trapezius, It is more fully shown in Fig. 67 and 72. ;

Supra-cervico-cutaneus (§ 615).—Most of this cervical dermal muscle was lifted with
the skin, and only its reflected dorsal end is shown.

Teres (§ 680).—This appears in the interval between the spino-trapezius, spino-deltoideus,
latissimus and triceps. By inadvertence, the name is written with the addition of the
qualifying adjective major ; since the muscle more often called teres minor is here desig-
nated as micostalis, there seems to be no need of a compound term for the muscle in question.

Triceps.— The name is written across the two largest portions of the muscle commonly
known as iriceps in man. The M. is upon the scapular head, here called meditriceps
(§ 682), and most of the rest of the name is upon the part here called ectotriceps ($ 684);
the surface of the latter presents a superficial furrow.

Other Parts.—Gi. (glandula lymphatica).—A somewhat large lymphatic gland embed-
ded in the fat which occupies the hiatus trapezii.

Gl. (glandula) parotis—The parotid salivary gland (Fig. §7).—The caudal border of
this usually pale gland is exposed by slightly cephaloducting the occipito-presternal edge
of skin.

Gi. (glandula) submazillaris—The submaxillary salivary gland (Fig. 87)—This appears
a little ventrad of the GJ. parotis, and is usually of a deeper color.

Hiatus trapezii (§ 613).—This is an elongated lozenge-shaped interval between the
cephalic margin of the M. acromio-trapezius and the caudal and dorso-caudal margins
respectively of the MM. clavo-trapezius and levator clavicule. In reality, the very open
angle formed by the intersection of these two borders is near the middle of the length of
the hiatus, but in the preparation the margins of the MM. clavo-trapezius and acromio-
trapezius have been artificially separated a little farther dorsad.

V. (vena) jugularis—The jugular vein (Fig. 101).—This is exposed between the M.
clavo-trapezius and the margin of the skin, where it obliquely crosses the M. sterno-mastot-
deus.

§ 609. Exposure.—It is usually more convenient to expose the

THE TRAPEZIUS GROUP. 211

entire trapezius group by lifting a single large flap of skin. This
flap, however, may be divided afterward so that one or two of the
muscles may be covered while the other is under examination. In
so doing, the skin is more easily divided ento-ectad (from within
outward).

Clavicuta-- -f
yaopr?

elbow

Fie. 66.—THE EcraAL SKELETAL MUSCLES OF THE LEFT

SHOULDER AND NECK, AFTER REMOVAL OF THE DER-

A MAL MuscuEs. (The left side of the head is shown in
outline below in order to facilitate the student’s recogni-

tion of the regions in this his first systematic dissection. )

212 ANATOMICAL TECHNOLOGY.

§ 610. Caution.—In making all incisions through the skin of
the cat, it is necessary, in addition to the general directions in § 599,
to keep in mind the presence of the I. dermo-humeralis (§ 629) and
other muscles constituting the panniculus carnosus, a thin muscu-
lar layer between the skin and the proper skeletal muscles.

The dermal muscle is usually to be divided and lifted with the
skin. With fleshy animals, the risk of cutting at the same time
the underlying skeletal muscles is obviated by the intervention of a
layer of fat which should also be removed with the skin (§ 600).
With lean animals, the two sets of muscles may usually be distin-
guished from the thinness and paleness of the dermal layer, and
from the fact that it is moved when the skin is pulled in any
direction.

Connect (§ 587) the praesternum (Fig. 30 and 49, § 228), with the
thirteenth thoracic neural spine (Fig. 30 and 66, § 227), and with a
point 1 cm. cephalad of the crista lambdoidalis (Fig. 56, § 226).

The occipito-presternal incision should have a slight caudal con-
vexity so as to skirt the base of the ear. The vertebro-presternal
incision should cross the brachium at about the junction of its first
and second fourths; this incision may be commenced at the middle
of its length, and be carried thence in both directions. Lift the flap
at the presternal angle, and remove with the skin the fat, connective
tissue and dermal muscles. Reflect it across the dorsimeson.

M. SPINO-TRAPEZIUS.

§ 611. Synonymy.—The caudal part of the human frapezius,Q., A, 1, 187; G.,A,
378; dorso-cucullaire, 8.-D., A, Tl, 334; portion dorsale du trapée, Ch., A, Fig. 90,
“1,” 216 ; dorsal trapezius, Ch. (F1.), A, 203; hinder portion of the trapezius, Miv., B, 137.

Figures.—Ectal aspect (66) ; insertion (67, 44); transection (99, 100).

General Description—An elongated triangle, from the thoracic
dorsimeson to the mesoscapula and the surface of the ZI. supra-
spinatus and infraspinatus.

Dissection.—The ventro-caudal border will appear as a slightly
raised line nearly parallel with the presterno-vertebral margin of
the skin. In recent specimens the color of the muscle is usually a
brighter red than that of the subjacent IZ. latissimus.

Lift the border near its middle, and trace it mesad, noting that,
about 1 em. from the meson, the muscular fibers are replaced by a
thin tendon which is not always easily separated from the subjacent
muscle. Then trace the border ventro-cephalad, noting that it

M. SPINO-TRAPEZIUS. 213

thickens slightly as it crosses the vertebral border of the scapula,
and ends upon the fascia covering the WZ. infraspinatus.

Continue to lift the ventro-caudal border, and dissect up the
middle part of the muscle as far cephalad as possible ; then pull it
caudad, and at the same time dorsad or ventrad. This will indicate
the cephalic border, which is much shorter than the other, and
extends latero-ventrad from a point between the Ist and 4th tho-
racic neural spines.

The dorsal half of the cephalic border is muscular, and separable
without much difficulty from the adjacent caudal border of the J/.
acromio-trapezius. Opposite, or slightly dorsad of, the vertebral
border of the scapula, the border of the IZ. spino-trapezius becomes
tendinous, thin and indistinct, so that its true limits are best ascer-
tained by pulling upon the muscular portion. It isalso overlapped |
to some extent by the JZ. acromio-trapezius.

The cephalic border of the muscle may easily be traced, entad
of the tendon of the I. acromio-trapezius, to a point 8-10 mm.
cephalad of the mesoscapula, and about the same distance from the
nearest part of the border of the scapula. Here it terminates upon
the fascia covering the I. supraspinatus.

The muscle should now be transected (§ 586), and the ental
surface cleared of fat, especially near the attachments.

§ 612. Origin.—From the tips and interspinous ligaments of most
or all of the thoracic neural spines. The attachment of the cephalic
border may be at any point between the 1st and 4th spine, and that
of the ventro-caudal border at any point between the 11th and 13th.
The origin of the caudal 2-3 cm. is by a triangular tendon, the lat-
eral angle of which is 1 cm. from the meson. ‘The rest of the muscle
arises by fleshy fibers. Opposite the cephalic 3 or 4 spines there
are sometimes slight intervals filled with loose connective tissue ;
opposite the others, the corresponding intervals, when they exist,
are occupied by a firm fascia which practically renders the attach-
ment continuous across the spines.

Insertion.— Along a curved s-shaped line obliquely crossing the
mesoscapula (Fig. 44). The cephalic two thirds of the insertion is
by a thin tendon 1-2 cm. long and 1-1.5 em. wide, which is attached
to the fascia upon the ectal aspect of the supraspinatus, and to the
mesoscapular tuberosity which it crosses very obliquely. Here it
joins the caudal and usually fleshy third of the insertion, which
extends upon the fascia covering the infraspinatus at an angle of

214 . ANATOMICAL TECHNOLOGY.

about 45 degrees with the mesoscapula. On the ectal surface of the
spino-trapezius, along the line of union of the muscular and ten-
dinous parts, is received the insertion of the acromio-trapezius
(Fig. 67).

M. ACROMIO-TRAPEZIUS.

§ 613. Synonymy.—The intermediate part of the human trapezius, G., 373; Q., I,
187 ; acromio-cucullaire, 8.-D., A, Il, 338; portion cervicale du trapéze, Ch., A, 216, and
Fig. 90; cervical trapezius, Ch. (F1.), A, 303; anterior part of the trapezius, Miv.,
B, 137.

Figures.—Kctal aspect (66) ; ental aspect and insertion (67); insertion area (44),

General Description.—Thin ; sub-trapezoidal ; from the dorsi-
meson, in the caudai part of the cervical region and sometimes also
the cephalic part of the thoracic, to the metacromion, and the adja-
cent surface of the M. spino-trapezius.

Dissection.—The caudal border has been indicated in dsacéibbng
the spino-trapezius, which is often slightly overlapped by it. It
nearly coincides with a line drawn between the vertebral ends of the
two mesoscapule. Lift it at the vertebral border of the scapula,
and note that, 8-10 mm. from the meson, it becomes a thin tendon
which may be traced across the meson to its platetrope without
severing any definite attachments to the subjacent parts. Ventrad
it may be traced to a point about 1 cm. caudad of the mesoscapula,
and 1.5 to 2 cm. from the nearest part of the vertebral border of the
scapula where it terminates upon the ectal surface of the spino-
trapezius.

The cephalic border of the muscle may be recognized as forming
the caudal margin of a narrow intermuscular interval, the hiatus
trapezti, at the side of the neck, about midway between the convex-
ity of the shoulder and the meson. This interval is filled with con-
nective tissue and fat, in which are imbedded a lymphatic gland
and an artery.

Follow this border to the meson, noting that, for about 1 cm.
therefrom, it is either continuous with the caudal border of the next
muscle (clavo-trapezius) or slightly overlapped by it. They may
be separated, however, without cutting fibers. Ventrad of the hia-
tus this border is usually overlapped for 3-5 mm. by the /evator
clavicula, the border of which must be lifted with care. Transect
the acromio-trapezius at the vertebral border of the scapula.

§ 614. Origin.—In two or three parts: In the caudal five eighths
the thin tendon is continuous across the meson with its platetrope,

a

M, ACROMIO-TRAPEZIUS. 215

and is connected with the subjacent parts only by small nerves and
vessels. It thus spans the interval between the vertebral borders of
the scapule, which project slightly dorsad of the intervening verte-
bral region. In the next two or three eighths the median raphé of
the tendon is joined by a low median fascia which springs from the
supraspinous ligaments. Sometimes, in the cephalic eighth, the
muscular fibers reach the meson. The line of origin extends from
the caudal end of the axial spine to some point between the 1st and
4th thoracic spines, thus filling the interval between the spino-
trapezius and clavo-trapezius.

Insertion.—In three parts: (A) the cephalic fifth is attached to
the ectal surface of the metacromion (Fig. 44), and is usually over-
lapped by the dorsal border of the levator clavicule ; (B). the cau-
dal fourth or fifth is attached to the ectal surface of the spino-
trapezius, along a dorso-caudal line forming an angle of 30-45
degrees with the mesoscapula ; (C) the intervening portion of the
muscle is inserted upon the glenoid border of the mesoscapula.

Remark.—The most notable feature of this muscle is the wide
tendon of origin, which with its platetrope forms a heart-shaped
area with its apex directed cephalad. The office of the muscle
seems to be mainly that of a ligament, to prevent the separation of
the vertebral borders of the scapule.

M. CLAVO-TRAPEZIUS.

§ 615. Synonymy.—The cephalic or clavicular portion of the- human trapezius, G., A,
378; Q., A, I, 187; clavo-cucullaire, 8.-D., A, Il, 332; part of the “ portion antérieure du
mastoido-humeral,” Ch., A, 209; part of the anterivr or superior portion of the mastoido-
humeralis, Ch. (F1.), A, 197; cephalic part of the “ cephalo-humeral,” Miv., B, 147, and
Wood, 9, 101, Fig. 23, “c.” Itis thought by some that this muscle does not represent
any part of the human trapezius.

Figures.—Ectal aspect (66); ental aspect of reflected ends (67) ; clavicular end (72).

General Description.—A wide teeniate muscle, from the occiput
and the cephalic part of the dorsimeson to the clavicle and the
trapezio-deltoid raphé.

Dissection.—The larger part of the cephalic border of the hiatus
mentioned under the dissection of the acromio-trapezius is formed
by the caudal border of the clavo-trapezius. Trace this border
dorsad, bearing in mind its close union with the cephalic border of
the acromio-trapezius. Then trace it ventrad, using great care in
lifting it from the subjacent levator clavicule, and noting that, ven-

216 ANATOMICAL TECHNOLOGY.

trad of the point of crossing, the interval between the two muscles is
filled with a fascia so dense as to practically unite them.

Lift the skin from 1-2 em. along the occipito-presternal line.
Dissect up the caudal border of the clavo-trapezius for 2-3 em. at
the junction of its dorsal and middle thirds, and pull it caudad.
This may serve to indicate the position of the ventro-cephalic bor-
der near the cut edge of the skin. Moreover, between the border
of the clavo-trapezius and the caudal border of the adjacent sterno-
mastoideus, just caudad of the ear, will be seen emerging one or
two nerves.

Follow the border of the clavo-trapezius to the crista lambdoi-
dalis, noting that, for 15-20 mm. therefrom, it is closely united with
the caudal border of the adjacent sterno-mastoideus. The two
muscles may usually be separated without cutting fibers, but some-
times a slender fasciculus passes from one to the other obliquely at
about the middle of their length.

Part of the occipital end of the muscle is covered by a small tri-
angular muscle belonging to the ear. This, the JZ. cervico-auricu-
laris (subcervico-pavilien of Straus-Durckheim, A, I, 194), is shown
in Fig. 66, but not named ; it must be removed with great care to a
point just cephalad of the crista lambdoidalis. Trace the ventro-
cephalic border of the clavo-trapezius to the clavicle, which may be
felt in the muscles between the preesternum and the convexity of
the shoulder.

Transect the muscle at its middle; in reflecting the ventral end
of the muscle, use great care in separating it from the subjacent
clavo-mastoideus, which is also attached to the clavicle. After
reflecting the dorsal part, divide it lengthwise along a line corre-
sponding with the angle formed by the meson with the crista lambdoi-
dalis ; the wider of the strips so formed may then be reflected across
the meson, and the narrower upon the head, as shown in Fig. 67.

§ 616. Origin.—In two parts: (A) by a thin tendon 5-10 mm.
long, from the mesal 10-15 mm. of the crista lambdoidalis; (B) by
' fleshy fibers from the supraspinous ligament for 4-5 em. from the
crest to the caudal end of the axial neural spine (Fig. 30, $§ 208, 471).

Insertion.—The details of the insertion differ considerably in
individuals, and perhaps in the same individual according to age
and the development of the clavicle. Sometimes the sternal end of
the clavicle projects about 1 mm. mesad of the 1. clavo-trapezius,

M. OCCIPITO-SCAPULARIS. 217

while in other cases the muscle extends mesad of the bone so as to
join the border of the ectopectoralis.

Pull the muscle dorso-cephalad, and note its apparent continua-
tion across the clavicle with the clavo-deltoideus. The muscles,
however, are joined by a raphé, the trapezio-deltoid, which is more
apparent upon the ental aspect. .Most of the clavo-trapezius is
inserted upon this raphé ; but the ental fibers of the cephalo-ventral
third or fourth are attached directly to the ventral border of the
sternal and straighter half of the clavicle. Variations in the mode
of insertion should be noted, drawn and reported.

M. OCCIPITO-SCAPULARIS.

§ 617. Synonymy.—There seems to be some doubt as to its human homologue ; rhom-
boideus capitis, Miv., B, 145, and Wood, 9, 92, Fig 23, ‘‘d” ; oceipito-scupulaire, 8.-D., A,
II, 381; part of rhombvide, Ch., A, 202 ; part of rhomboideus, Ch. (F1.), A, 188.

Figures.—Slightly at the dorsal end of the hiatus trapczit (66); ectal aspect (67);
lateral border (78); insertion area (45).

Exposure.—by the removal of the WM. acromio- and clavo-
trapezius.

General Description.—Narrow, teeniate, near—and nearly par-
allel with—the dorsimeson, from the crista lambdoidalis to the
coraco-vertebral angle of the scapula.

Dissection.—A bout midway between the occiput and the scapula
the lateral border of the muscle appears as a slightly raised line
10-15 mm. from the meson. ‘Trace it nearly to the occiput. Lateri-
duct the middle of the cephalic half of the muscle so as to indicate
its mesal border ; then transect.

§ 618. Origin.—By fleshy fibers from the crista lambdoidalis,
entad of the origin of the clavo-trapezius, beginning 5-10 mm. from
the meson, and extending 12-15 mm. laterad to a point nearly in
line with the temporo-parietal suture (§ 493), where it is overlapped
by the dorsal border of the sterno-mastoideus. Caudad, the mus-
cle gradually approaches the lateral border of the rhomboideus.
At the junction of the third with the last fourth, the muscle narrows
and thickens, so as to become prismatic rather than teeniate.

Insertion.—The narrowing muscle is wedged pretty closely
between the rhomboideus at its mesal side and the levator anguli
scapule at its lateral side, and is inserted either between these mus-
cles upon the coraco-vertebral angle of the scapula (Fig. 45), 6-16
mm. cephalad of the mesoscapula, or upon the ental surface of the

218 ANATOMICAL TECHNOLOGY.

second muscle close to its own insertion ; in some cases, these two
forms of attachment coexist.

§ 619. Explanation of Fig. 67.—The second layer of skeletal
muscles of the left shoulder and neck.

Preparation.—After the reflection of the skin and dermal mus-
cles as in Fig. 66, the following muscles were transected and re-
flected: spino-trapezius, acromio-trapezius, clavo-trapezius and

Fig. 67.—THE SECOND LAYER OF SKELETAL MUSCLES OF TRE NECK AND SHOULDER.

levator clavicule. The skin was also removed from the left side of
the head, together with the external ear, the parotid and submaxil-
lary salivary glands, and parts of the WM. temporalis and masseter.

Bones.—Acromion (§ 392).—This process of the mesoscapula is seen to afford origin to

the acromio-deltoideus.
Clavicula (8§ 422, 608).—By the reflection of the clavo-trapezius and the deflection of

the clavo-mastoideus, the clavicle is brought into view. Its name is connected with its
sternal end,

M. RHOMBOIDEUTS. 219

Cristadambdoidalis—The lambdoid ridge of the skull (Fig. 56).-The crest itself does
not distinctly appear, but its position coincides with the lines of attachment of the occipito-
scapularis and sterno-mastoideus and part of the clavo-trapezius.

Mesoscapula and metacromion (Fig. 44 and § 608).

Trochiter—The larger or cephalic tuberosity of the humerus (Fig. 30 and 74, § 420).

Zygoma—The zygomatic arch (Fig. 30, 56, §§ 207, 229). ~The outlines of this promi-
nent bony arch are shown just dorsad of the name.

Muscles.—The acromio-deltoideus (§ 670), dermo-humeralis (§ 629), spino-deltoideus
(§ 674), teres (§ 680), and triceps (§§ 682, 684), are sufficiently described in the explanation
of Fig. 66 (§ 608), and the supraspinatus, infraspinatus and teres (the word major is super-
fluous) in the explanation of Fig. 74 (§ 672). The masseter, temporalis, splenius and
digastricus are not particularly described in this work.

Acromio-trapezius (Fig. 66, § 613).—This was transected so as to leave the semicordate
tendon wholly in the vertebral part, which is reflected dorsad. The scapular part is
slightly lifted so as to show the manner of its connection with the ectal surface of the
spino-trapezius.

Clavo-trapezius (Fig. 66, § 615).—The clavicular end has been reflected. The other and
much wider end was longitudinally divided from the angle between the cephalic and mesal
parts of the origin, and the two portions thus formed were reflected respectively cephalad
and dorsad. The name is written upon the latter only.

Latissimus (Fig. 66, § 635).—By the removal of the vertebral end of the spino-trapezius,
the dorso-cephalic angle of this muscle is exposed. In the interval between its cephalic
border and the caudal border of the rhomboideus, are seen some of the proper vertebral
muscles. By inadvertence, the fibers in the dorso-cephalic corner are not represented as
parallel with the border.

Levator anguli scapule (Fig. 73, § 686).—A part of the ectal aspect is seen between the
splenius and the supraspinatus. The ental aspect of the whole muscle appears in Fig. 73.

Levator clavicule (§ 627).—This has been transected near its insertion upon the meta-
cromion, and the metacromial end is somewhat indistinctly seen reflected upon the spino-
deltoideus.

Oceipito-scapularis (§ 617).—The cephalic attachment is seen to have been covered by
that of the-clavo-trapezius, and its scapular end is wedged in between the rhomboideus and
the levator anguli scapule.

Rhomboideus (§ 620).—The cephalic border is not satisfactorily represented in this
figure. The scapular end of the muscle is better shown in Fig. 74.

Spino-trapezius (Fig. 66, § 611).—The vertebral end has been removed altogether.
The scapular end is lifted a little so as to show its relations with the acromio-trapezius and
with the ectal aspects of the supraspinatis, infraspinatus and spino-deltoideus.

Sterno-mastoideus (Fig. 72, § 622).—The removal of the clavo-trapezius, the salivary glands
and the external ear has exposed its cranial attachment and its intersection with the clavo-
mastoideus. Its sternal end and its connection with its platetrope are shown in Fig. 72.

Other Parts.—M. au. ex.— Meatus auditorius externus.—Its lumen is exposed by the
removal of the concha or external ear with the skin.

M. RHOMBOIDEUS.

§ 620. Synonymy.—The human rhomboideus major, with probably the r. minor also,
G., A, 375 ; Q., A, 191; rhomboide, 8.-D., A, II, 334 ; rhomboide, Ch., A, 202 ; rhomboideus,
Ch. (Fl.), A, 188; rhomboideus major, Miv., B, 145.

Figures.—Ectal aspect (67); scapular end, ectal aspect (74); scapular end, ental
aspect (75); insertion area (44, 45).

220 ANATOMICAL TECHNOLOGY.

General Description.—Trapezoidal in outline ; from the-caudal
part of the cervical dorsimeson and the cephalic part of the tho-
racic, to the vertebral border of the scapula.

Exposure.—By the removal of the MM. spino- and acromio-
trapezius.

Posture.—Ventricumbent, with one or two blocks lengthwise
under the thorax so as to permit the ventriduction of the shoulder.
Usually the body must be steadied by cords or chain-hooks. Lat-
eriduct the vertebral border of the scapula so as to render the J.
rhomboideus tense.

Dissection.—The ventro-cephalic border of the muscle has been
exposed by the reflection of the occipito-scapularis. The caudal
border may be seen along a line running nearly laterad from the
4th or 5th thoracic spine, opposite the gleno-vertebral angle of the
scapula. Noite that the texture of the muscle is looser than that of
the trapezii, and that the caudal border is thinner than the ventro-
cephalic, excepting the dorso-cephalic third of the latter. This
muscle may be safely transected by cutting ecto-entad ; in reflecting
it, note that the thickest part is opposite the 1st and 2d thoracic
spines.

§ 621. Origin.—In two parts: (A) from the caudal two or three
fifths of the cervical supraspinous ligament; in the latter case it
includes the caudal two thirds of the axial spine, and thus extends
about 1 cm. cephalad of the acromio-trapezius ; (B) from the sides
of the tips of the first four thoracic spines and from the interspinous
ligaments caudad of each of them, excepting, sometimes, the 4th.

Insertion.—At least two forms of insertion are found. The sim-
pler is as follows (Fig. 44, 45): the cephalic three fourths is attached
by short tendinous fibers along the vertebral border of the scapula,
passing gradually from its ental to its ectal margin. The cephalic
half or third of this portion is closely united with the insertion of
the levator anguli scapule. The caudal fourth is attached by
fleshy fibers upon the gleno-vertebral angle in apposition with the
origin of the teres.

The other mode of insertion presents four divisions: (A) the
cephalic 8 mm. is attached by fleshy fibers to the ental aspect of the
lev. ang. scap. close to its insertion upon the ental margin of. the
vertebral border of the scapula, and caudo-ventrad of the insertion
of the occipito-scapularis ; (B) the next 6-8 mm., constituting the
thickest part of the muscle, is attached by fleshy fibers to the ental

M. STERNO-MASTOIDEUS. 221

margin of the vertebral border, opposite the triangular space at the
vertebral end of the mesoscapula; (C) the next 2-2.3 em. is at-
tached by a thin tendon, 2-3 mm. long, upon the ectal margin of the
vertebral border from opposite the middle of the space just men-
tioned, and thus slightly overlapping part B, to within 8-10 mm. of
the gleno-vertebral angle of the scapula; (D) the caudal 5-6 mm.
is separated from the rest by an interval 1-5 mm. wide, and is in-
serted by fleshy or very short tendinous fibers upon the ectal aspect
of the gleno-vertebral angle in apposition with the origin of the
teres. The scapular end of the muscle may be separated more or
less readily into four divisions corresponding with the parts of the
insertion just described, and the caudal division is sometimes quite
distinct, with a decided extension toward the Zeves.

M. STERNO-MASTOIDEUS.

Remark.—This is strictly a muscle of the neck, but is here described on account of its
close relations with the muscles of the shoulder and with blood-vessels.

§ 622. Synonymy.—The sternal part of the human sterno-cleido-mastoid, G., A, 357;
Q., A, 1, 292; sterno-mastoidien, S.-D., A, I, 248 ; sterno-mawiilaire, Ch., A, 210 ; sterno-
mazillaris, Ch. (Fl.), A, 198; sterno-mastoid, Miv., B, 134.

Figures.—Lateral aspect of cephalic half (66); lateral aspect (67); united sternal por-
tions (72) ; sternal portion (73).

§ 623. General Description.—Teeniate, along the ventro-cephalic
border of the clavo-trapezius, from the presternum to the mastoid
process of the temporal bone and the ventral part of the crista
lambdoidalis.

Posture.—Latericumbent ; a block transversely under the neck ;
the head hanging.

Exposure.—Connect the angle of the mouth with the occipito-
presternal line (§ 610) by an incision corresponding with the direction
of the margin of the upper lip. Note that the skin of the cheek,
especially in old males, is very thick. Dissect up both edges of the
skin for about 1 cm.

The zygoma (Fig. 30, 56, 67) may be felt as a firm bony arch
between the Jf. temporalis (Fig. 67) dorsad, and the JL. masseter
ventrad.

Just caudad of the zygoma may be felt the cartilaginous meatus
auditorius (Fig. 67, Mt. aw. ex.), partly embraced by the small,
pale and rather loose-textured parotid gland (Fig. 87, 107). Divide
the meatus close to the head, and reflect the flap, together with the

222 ANATOMICAL TECHNOLOGY.

ear and parotid, for 2-3 cm., taking care not to cut caudad of the
crista.

Then reflect the ventral flap for about the same distance. In the
depression just caudad of the mandibular angle note the firmer tex-
tured and darker colored submazillary gland (Fig. 66, 87). Its
dorsal border is often quite firmly attached to the ventral border
and ectal surface of the sterno-mastoideus. Remove the gland, —
together with the dense connective tissue in the groove between the
head and the neck ventrad of the origin of the occipito-scapularis.

Along the ventral border of the space occupied by the submax-
illary gland is the Vena jugularis (Fig. 101), which lies upon the
ectal aspect of the sterno-mastoideus, crossing very obliquely from
its ventral to its dorsal border. Divide the vein at the middle of its
length, reflect the ends and free the surface of the muscle from fat
and connective tissue.

Dissection.—The dorsal border of the muscle is apparent at
about its middle, where it was crossed by the V. jugularis, and
where it in turn crosses the ventral border of the subjacent clavo-
mastoideus. Lift this border, taking care not to include the fibers
of the clavo-mastoideus. A little cephalad of the middle of the
length of the muscle dissect from the dorsal to the ventral border.

In reflecting the cephalic part, note that the ventral border is
thickened as if folded upon itself, and that, at the occiput, the dor-

sal. border may overlap the occipito-scapularis for half the width
of the latter. In reflecting the caudal part, note that, about the
middle of the length of the whole muscle, it joins its platetrope, the
fibers appearing to interdigitate to some extent (Fig. 72). About
2 em. cephalad of the preesternum the muscle is overlapped by the
ectal lamina of the ectopectoralis.

§ 624. Origin.—On account of the overlapping just mentioned,
the farther dissection of the sternal end of the muscle is better
deferred until after the examination of the ectopectoralis.

Insertion.—The cephalic attachment of the muscle is by a tendon
2-7 mm. long which is inserted upon the crista lambdoidalis laterad
of, and usually overlapping to some extent, the origin of the occip-
ito-scapularis. The line of insertion extends not only along the
crista, but also upon the rather sharp ridge of the mastoid process,
which ceases suddenly at a slight elevation just dorso-caudad of the
stylo-mastoid foramen, 3-4 mm. from the meatus. The tendon is
here a little thicker than at other points, and between it and the

M. CLAVO-MASTOIDEUS. 223

tendon of the subjacent splenius (Fig. 67) there is sometimes a well-
defined depression.
M. CLAVO-MASTOIDEUS. |

§ 625. Synonymy.—The clavicular part of the human sterno-cleido-mastoid, G., A,
357; Q., A, I, 292 ; “ cleido-mastoidien,” 8.-D., A, Il, 333 ; part of the “ mastoido-huméral,”
Ch., A, 209, Fig. 90; part of the mastoido-humeralis, Ch. (F1.), A, 196; part of the cephalo-
humeral, Miv., B, 147 ; cleido-mastoid, Wood, 9, 101, Fig. 23, “bd.”

Figures. — Lateral aspect (67) ; ventral border of clavicular part (72).

General Description.—Narrow, teniate, from the clavicle to the
mastoid process.

Posture. —Latericumbent, the block transversely under the neck,
and the head hanging.

Exposure.—By the reflection of the clavo-trapezius and the
sterno-mastoideus.

Dissection.—The dorsal border is apparent at about its middle.
Raise it, and draw the muscle dorsad so as to indicate its ventral
border. In reflecting the cephalic part, note that, about 18 mm.
from the head, the muscle is perforated by a nerve, near which,
entad of the muscle, lies the separate lateral half of the thyroid
body. In reflecting the caudal part, note the constant increase in
width to the clavicle, that the V. gugularis lies mesad of it, and
usually a lymphatic gland entad of it, while its dorsal border is
attached by a firm fascia to the ventral border of the levator cla-
vicule.

§ 626. Origin.—In two nearly equal parts: (A) the ventral part
arises, with the corresponding part of the insertion of the clavo-tra-
pezius, from the ventro-cephalic border of the sternal half or three
fifths of the clavicle ; (B) the remainder arises from the ental aspect
of the ¢rapezio-deltoid raphé, but is connected with the scapular
part of the clavicle by a strong fascia which might be regarded
as a common tendon of attachment for the corresponding parts of
the clavo-trapezius, clavo-mastoideus and clavo-deltoideus:

Insertion.—By fleshy fibers upon the ventral and caudal bor-
ders of the mastoid process, and upon its mesal side.

Remark.—Respecting the choice of origin and insertion for this
muscle, see § 579.

M. LEVATOR CLAVICUL.

§ 627. Synonymy.—* Transverso-scapulaire,’ 8.-D., A, II, 331; “levator clavicule,”
Wood, 9, 95, Fig. 23, “e” ; trachelo-acromialis, Huxley, A, 418; levator scapularis, Miv.,
B, 148; not found sormeliy' in man.

Figures.—Scapular part (66, 67) ; insertion area (45).

224 ANATOMICAL TECHNOLOGY.

Posture.—Latericumbent, with a block transversely under the
neck. The posture must be changed often and greatly in the course
of the exposure and dissection.

Exposure.—By the reflection of the clavo-trapezius, sterno-
mastoideus and clavo-deltoideus. Note that, after the reflection of
the above named muscles and the occipito-scapularis, the broad
transverse process of the atlas is covered, dorsally, by a thick mass
of muscle, the most ectal of which, the splenius (Fig. 67), presents
a smooth and convex surface. Remove this mass by deep incisions
with the arthrotome as follows: Laterad from the cephalic end of
the origin of the rhomboideus ; then cephalad to the occiput; then
laterad close to the occiput, but without severing any of the muscu-
lar attachments along the crest; finally, beginning with the meson,
dissect up the mass from the vertebra.

General Description.—Narrow, teniate, from the basioccipital
bone (Fig. 57) and atlantal transverse process or diapophysis
(Fig. 52) to the metacromion (Fig. 44).

Dissection.—The dorsal border of the scapular end has been indi-
cated (§ 614) in connection with the insertion of the cephalic border
of the acromio-trapezius. Trace it cephalad, and draw the middle
of the muscle dorsad so as to indicate its ventral border.

In reflecting the caudal part, note a lymphatic gland close to the
coracoid border of the swpraspinatus. In reflecting the cephalic
part, note that, a little caudad of the atlantal transverse process, its
plane gradually changes from dorso-ventral to dextro-sinistral, and
that there are signs of subdivision.

Remove the muscles ventrad and cephalad of the atlantal trans-
verse process, but without cutting the attachment of this muscle to
its ventral surface. Feel for the prominent auditory bulla just
mesad of the JZ masseter and the meatus, and carefully dissect
off the IZ. digastricus, which covers it. Avoid the external carotid
artery which skirts the meso-cephalic border of the bulla, and the
hyoid arch (Fig. 30) which lies imbedded in the muscles between
it and the artery.

Then use the tracer to clear away the connective tissue, and the
arthrotome to scrape the ventral surface of the transverse process
of the atlas, excepting where it is occupied by the origin of the dev-
ator clavicule. Between the border of the process and the larynx
and trachea note and remove the lateral lobe of the thyroid body.

M. DERMO-HUMERALIS. 225

Note, but do not remove, the carotid artery, and the nervous trunk
representing the conjoined V/V. vagus and sympathicus (Fig. 107).

§ 628. Origin.—The larger and constant head arises by fleshy
fibers from the ventral surface of the atlantal transverse process
along an oblique line extending from the junction of the process
with the body of the vertebra, 3-4 mm. from the meson, latero-caudad
to a point about 3 mm. cephalad of the caudo-lateral angle of the
process. This line of origin is 6-8 mm. long, and is nearly parallel
with the oblique meso-caudal border of the arthral surface in con-
tact with the axis.

The smaller and less constant head is about 3 mm. wide and is
the more direct continuation of the ventral border of the muscle.
Opposite the latero-cephalic angle of the transverse process it be-
comes a thin flat tendon which is closely applied to the ventro-
lateral aspect of a muscle, the WZ. rectus anticus capitis, which
extends along the ventral side of the vertebree, and is inserted with
it into the basioccipital bone nearer the bulla (Fig. 57) than the
meson, and about midway between the jugular foramen (Fig. 57,
Fm. j.) and the cephalic angle of the bulla. This, the occipital
head of the muscle, is sometimes absent, and other irregularities
have been observed in the cephalic end of the muscle.

Insertion.—By a strong tendon 1-2 mm. long and a little nar-
rower than the muscle, upon the ectal surface of the metacromion
(Fig. 45, 67), close to its free border. The dorsal border slightly
overlaps the ventral border of the acromio-trapezius near its inser-
tion, and the ventral border is firmly joined by a strong fascia with
the clavo-trapezius.

M. DERMO-HUMERALIS.

§ 629. Synonymy.— Dermo-huméral,” §.-D., A, Il, 251; part of the “ pannicule
charnu,’ Ch., A, 200; part of the fleshy pannicle, Ch. (F1.), A, 186; part of the pannicu-
lus carnosus, Miv., B, 136; not represented in man.

Figures.—Humeral part, ectal aspect (66, 74); partly reflected (67, 72, 73).

Posture.—Latericumbent, the ventral region toward the dis-
sector; a block transversely under the thorax, just caudad of the
elbows.

Exposure.—Connect the last (13th) thoracic spinous process
with the ventrimeson by a dorso-ventral incision. Be careful to
divide only the skin, with the subcutaneous fat and connective tis-
sue, together with a thin sheet of pale muscular fibers, the dermo-

15

226 ANATOMICAL TECHNOLOGY.

humeralis, and avoid cutting the ental, thicker and darker colored
latissimus (Fig. 66), the cephalic part of which was exposed in the
dissection of the spino-trapezius.

Begin to lift the flap at the dorsimeson ; remove the fat and con-
nective tissue from the ental surface of the dermo-humeralis, and
note that its fibers have nearly the same direction as those of the
latissimus. When the caudo-ventral border of the latissimus is
reached, a little ventrad of the middle of the incision, be careful not
to lift with the skin and dermo-humeralis, the thin dorso-caudal
margin of the IZ. ziphi-humeralis (Fig. 72), a member of the pecto-
ralis group of muscles, which arises at the meson, and sometimes
adheres quite closely to the dermo-humeralis.

General Description.—<As stated by Straus-Durckheim (A, I,
251), ‘‘this muscle covers as a mantle the whole thorax and abdo-
men, . . . but differs from the skin-muscles proper in the attach-
ment of one end to the skeleton ;’’ this attachment, however, is
only indirect.

Dissection.—The cephalic and shorter border of the muscle may
be seen on the ental surface of the skin along a dorso-ventral line
from the 2d or 3d thoracic spine to the axilla. The caudo-ventral
border is less distinct, but may be detected 1-2 cm. from the meson.
Connect the two borders by an incision 3-4 cm. from the brachium.
Leave the caudal portion of the muscle upon the skin, but carefully
dissect up the narrower and thicker brachial part, freeing both its
ectal and ental surfaces from fat and connective tissue. Note that
it not only overlies the corresponding part of the ldatissimus, but
that its ental surface becomes intimately united with the ectal sur-
face of that muscle.

§ 630. Origin.—From the skin, along an oblique line extending
ventro-cephalad from about the middle of the length of the pelvis
upon the caudal aspect of the meros as far as the knee; also along
a line which is just laterad of the dorsimeson opposite the 2d or 3d
thoracic spine, but which gradually leaves the meson as it extends
caudad to join the pelvic line already mentioned.

Insertion.—From the broad origin above described the fasciculi
converge ventro-cephalad toward the caudal aspect of the brachium.
The muscle becomes narrower and thicker, and less closely attached
to the skin. Near the dorsal border of the brachium it joins the
ectal surface of the subjacent Zatissimus. The dorsal border, 1-1.3
cm. wide, is attached directly by muscular fibers, but the remain-

THE HUMERUS. 227

der ends as a thin tendon ranging from 1-3 cm. long. The details
of its indirect connection, through the latissimus, with the bicipital
arch (Fig. 73), and thus with the humerus, may be examined more
conveniently after the dissection of the pectorales.

Remark.—This muscle does not exist in man, where the group
of dermal muscles is represented only by the JZ. platysma myoides
upon the sides of the neck, and by certain muscles of the face.

§ 631. Explanation of Figures 68-71 inclusive.—These represent respectively the
cephalic (outer), ventral (anterior), caudal (inner), and dorsal (posterior) aspects of the left
humerus.

A shaded representation of the ventral aspect of the right humerus is given in Fig. 46.
These four figures are little more than outlines for the sake of indicating the attachment
areas and lines of the muscles or muscular divisions described in this work which arise
from or are inserted upon this bone.

As in the figures of the scapula (Fig. 48, 44), the lines enclosing origins are composed
of dots, and those enclosing insertions of short dashes.

In order to place the figures across the page, and so facilitate reference and comparison,
many of the parts are undesirably small, and several are so crowded as to be indistinct.

The attachments are at least approximately correct for the majority of cases, but con-
siderable variation is to be expected.

The identification of the muscles, especially those of the pectoralis group, is much
facilitated by the use of a carved wooden model of the humerus, enlarged 4 or 5 diameters
so as to increase both the attachment areas and the spaces between them. Such a model,
made by Mr. H. W. Turner, a special student, has been in use for several years in the
Anatomical Laboratory of Cornell University.

The following features of the humerus itself are shown and sufficiently described in
the descriptions of Fig. 45 B and Fig. 46 :—

On. (canalis) bicipitalis (69, 70), $$ 402, 409 ; capitellum (69), § 410; caput articulare
(71), $$ 403, 411 ; erista deltoidea (68, 69), § 412 ; ers. (crista) epicondylaris (68, 71), § 415 ;
epicondylus (69,71), § 415; epitrochlea (69, 70, 71), § 416; Hm. (foramen) epitrochleare
(69, 70, 71), $ 417; trochin (69, 71), $§ 405, 420; trochiter (68, 69, 71), $$ 406, 420 ; trochlea
(69), § 420.

The following parts are not designated upon these figures, but may be recognized from
the other figures and descriptions :—

Crista pectoralis (Fig. 46, § 413); fossa ulnaris and fossa radialis (Fig. 46, § 418): fossa
trochiteriana (Fig.45 B, §§ 404, 679).

The following parts are not described elsewhere :—

Crista epitrochlearis.—This name may be applied to the ridge which extends proximad
from the epitrochlea (Fig. 69).

Fim. ( foramen) medullare—The medullary or nutrient foramen (Fig. 70).—This opens
upon the caudal aspect of the diaphysis, at about the junction of the middle and distal
thirds of the bone. It points distad from the surface.

F%. ( fossa) olecranalis—The olecranon fossa (Fig. 71).—This is a deep and irregular
depression upon the dorsal aspect of the extremitas distalis. When the antebrachium is
extended, the olecranon of the ulna is received by it. We have never observed a perfora-
tion of the bone at this point, as is sometimes the case with man.

228 ANATOMICAL TECHNOLOGY.

eM $pino-deltoideus,

N. a Wi apne cerns \

ae dylus M, estopectorai tn. eetalis . he
1M. extensor ulnaris ESS

: 1 iM. ex. rad. brev ior, an ‘

M, eek Le naTus.

\Crista é@ epi condylars Pi entatriceps »

'M, extensor “u 5
‘M. €xtensor fF sj ot M. ectotriceps
M. micostalis-”

Fie. 68. M. infraspinatus’

M. xiphi- -humeralis (A.B. Gs
trochin-

MM>latissimus et teres,
Pee Ml. Suepeciaaua wit Sattee iss
‘EDE -

é ‘im nec

ae ecto~, Jim. entalis dv. cephalica! | 1M, entopectorall) \
‘Capitellum- pecne falls tm. entalis dv. caudalis: AV. cephalica f \
Fic. 69. M. Supraspinatis

trochin,
M, subscapularis |

M entopectaralis dy. ccaatie
M. entopectoralis, dy. cophalica!
M, supraspinatust

Pic ae :

UM. ext mi nime

| / OM, eX. Communis ,

Crs, Lee eee
M: extensor ont long

dv. caudaus TS
M, coracoideusty

ce breve

ih'subsccpularis e
trocht

SM, entotriceps clv. brevis
ronator Fie. 71.

epit chlea

Fie. 68-71.—THE HUMERUS.

M. LATISSIMUS. 229

§ 633. Upon Figures 68-71 are represented the insertion areas or lines of the following
muscles ; the list includes all which are inserted upon the humerus :—

Acromio-deltoideus (68), § 676 ; coracoideus, caput breve (70), caput longum (71), § 668 ;
ectupectoralis, lm. ectalis (68, 69), § 649; ectopectoralis, lm. entalis, do. caudalis (69), § 653 ;
ectopectoralis, lm. entalis, dv. cephalica (68, 69), § 651 ; entopectoralis, dv. caudalis (69, 70),
§ 656; entopectoralis, dv. cephalica (69, 70), § 658; infraspinatus (68), § 678; micostalis
(68), § 679 ; spino-deltoideus (68), § 674; supraspinatus (68, 69), § 675 ; teres (69, 70), $ 680 ;
xiphi-humeralis (69), § 660.

As stated in § 670, the insertion of the coracoideus, caput longum, is so variable that
the area is here indicated on Fig. 71 by an interrogation point.

§ 634. The origin areas or lines of the following 13 muscles are represented upon
Fig. 68-71 :—

Brachialis (68, 71), § 692; entotriceps, dv. brevis (70, 71), § 688, dv. caudalis (70, 71),
§ 687, dv. cephalica (71), § 689, dv. intermedia (68, 71), § 686 ; extensor digitorum com-
munis (68, 71), § 697 ; extensor minimi (68, 71), § 698 ; extensor radialis brevior (68), § 696 ;
eat. rad. longior (68, 71), § 694; extensor ulnaris (68), § 699; flexor radiatis (70), § 702;
pronator teres (70, 71), § 701 ; swpinator longus (71), § 690.

M. LATISSIMUS. ‘

§ 635. Synonymy.—Latissimus dorsi, Q., A, 1,189; G., A, 874; “grand dorsal,”
S.-D., A, II, 389; “‘ grand dorsal,” Ch., A, 217, Fig. 90 ; great dorsal, Ch. (FI.), A, 208 ;
latissimus dorsi, Miv., B, 187.

Figures.—Kctal aspect (66, 67, 74) ; ental aspect (72, 73, 75); insertion area (69, 70) ;
transection (99, 100).

Posture.—Latericumbent, the venter toward the dissector; a
block transversely under the thorax just caudad of the elbows.

Exposure.—Most of the muscle has been exposed by the re-
moval of the spino-trapezius and dermo-humeralis, and needs only
to have its ectal surface cleared. If the caudal region of the body
has not been removed, the corresponding part of the latissimus
may be exposed by dividing the skin and the dermo-humeralis
along a dorso-caudal line from the already exposed caudo-ventral
border of the datissimus to the crista ilii (§ 230, Fig. 51) of the op-
posite side, and reflecting the flap so formed across the dorsimeson.

General Description.—A large triangular sheet, covering rather
more than the dorso-cephalic half of the abdomen and thorax, ex-
cepting so much of the latter as is between the scapule. It arises
at the dorsimeson between the pelvis and the 5th thoracic spine,
and is inserted upon the humerus, forming part of the bicipital
arch (Fig. 73).

Dissection.—Lift the caudo-ventral border where it crosses the
7th rib (which is also the 7th counting from the last), and trace it
both ways for 2-3 cm. Trace the cephalic border from the vertebral

230 ANATOMICAL TECHNOLOGY.

border.of the scapula along a dorso-ventral line from the 5th tho-
racic neural spine.

Transect the muscle along a line between the 7th rib and the
vertebral border of the scapula, beginning at the caudo-ventral
border and alternately lifting and dividing the successive parts.
Toward the meson, along a line extending ventro-caudad from the
10th, 11th or 12th thoracic spine to the lateral border of the verte-
bral muscles, about 3 cm. from the meson, the muscular sheet gives
place to a strong fascia.

In reflecting the brachial portion of the muscle, note the attach-
ment of the dermo-humeralis to its ectal surface (Fig. 74), its close
relations with the subjacent I. ziphi-humeralis, and the presence
of a lymphatic gland near the dorso-caudal border of the latter.
Turn the arm so as to bring the convexity of the elbow dorsad, and
thus expose the space between the brachium and the scapula, and
note that the ental surface of the latissimus is joined, near its
cephalic border, by a thick muscle, the ¢eres (Fig. 75), from the
elenoid border of the scapula, and that, from. the ectal surface, close
to the attachment of the dermo-humeralis, there proceeds distad a
muscle, the epitrochlearis (Fig. 75).

The details of the connection of the Zatissimuws with the humerus
and the bicipital arch are more easily examined after the dissection
of the pectoralis group, and the removal of the arm from the body.

§ 636. Origin.—In two parts: (A) by muscular or short tendi-
nous fibers from the sides of the tips of the thoracic spines from the
4th or 5th to the 10th inclusive, and from the corresponding inter-
spinous ligaments ; this part of the origin is wholly covered by the
origin of the spino-trapezius ; (B) from the dorsimeson, between
the 10th thoracic spine and the sacrum, by a strong triangular ten-
don, the lateral angle of which corresponds nearly with the lateral
border of the vertebral mass of muscles.

Insertion.—At the junction of the 2d and 3d fourths of the hu-
merus, upon its ventral aspect, by a thick tendon which forms the
caudal pillar of the bicipital arch.

The detailed description of the insertion must include that of the
M. teres (§ 680, Fig. '75); but though the tendons of the two muscles
are inseparably united, there are indications of the manner of their
junction. The joint tendon, at a point midway between the hume-
ral end and the point of separation of the two muscles, is wholly
tendinous as to the distal fifth of the caudal surface which seems to

M. CiLAVO-DELTOIDEUS. 231

form the direct continuation of the latissimus, while the remainder
is chiefly muscular. The cephalic surface presents the opposite
appearance, being muscular as to its proximal fifth. In general, it
is as if the shorter tendon of the teres were applied upon the longer
tendon of the datissimus in such a way that the distal border of the
latter shows upon the caudal surface of the joimt tendon, while the
proximal border of the former shows upon the cephalic surface.

The area of attachment (Fig. 71, 72) is about one seventh of the
length of the entire humerus, and forms an elongated fossa upon
the caudal surface, near the ventral border; its proximal end is
opposite the distal end of the area of insertion of the short head of
the coracoideus.

M. CLAVO-DELTOIDEUS.

§ 637. Synonymy.—The clavicular portion of the human deltoideus, G., A, 444; Q.
A, 1,199 ; “ delto-claviculaire,” 8.-D., A, I, 351 ; “ portion du mastoido-huméral,” Ch., A,
209 ; portion of the mastoido-huméral, Ch. (F1. ) A, 197 ; pertgn: of the cephalo- Seuneval
Miv., B, 147; Wood, 9, 101.

Figures.—Ectal aspect, clavicular end (66); ectal aspect of whole (72, right side);
ental aspect of antebrachial part (72, left side).

Posture.—Latericumbent, the venter toward the dissector. Se-
cure the arm caudiducted so as to stretch the muscles upon the
ventral aspect of the brachium and shoulder.

Exposure.—The proximal end of the musclewas exposed dur-
ing the exposure of the clavo-trapezius. Connect the vertebro-pre-
sternal incision made in exposing the ¢rapezii with the dorsal border
of the antebrachium, at the junction of the proximal and middle
thirds, by an incision along the ventral border of the brachium and
passing caudad of the elbow. Reflect both edges of the skin for
2-3 cm. near the shoulder, and for 1-2 cm. near the elbow.

General Description.—Teeniate; along the ventral aspect of.
the brachium, from the clavicle to the ulna.

Dissection.— Draw the clavicular portions of the clavo-trapezius
and clavo-mastoideus away from the body so as to expose the more
or less distinct bands—hardly deserving the name of ligaments—
which pass from the ends of the clavicle to the shoulder and neck.
In a subsequent dissection of the parts these connections may be
studied in detail before division. Divide them and draw the same
muscles cephalad so as to render tense the clavo-deltoideus, and
indicate the general position and direction of its borders.

The caudal border begins at the sternal end of the clavicle,

> .

232 ANATOMICAL TECHNOLOGY.

crosses obliquely the subjacent ectal lamina of the W. ectopectoralis
(Fig. 72, right-side), and, at the junction of the proximal and middle
thirds of the brachium, is separated by only a slender line of con-
nective tissue from the cephalic division of the pecto-antebrachialis.

The cephalic border is the direct continuation of the caudal bor-
der of the clavo-trapezius, but is attached quite firmly to the strong ~
fascia covering the cephalic surface of the brachium. The muscle,
with the clavicle attached, may now be dissected up as far as the
ventral border of the antebrachium, but the distal half of the cau-
dal border cannot usually be separated from the pecto-antebrachi-
alis without cutting fibers. The examination of the insertion can
be made more easily after the removal of some other muscles.

§ 638. Origin.—As stated under the clavo-trapezius (§ 615), the
clavo-deltoideus, viewed from its ectal surface, is apparently the
direct continuation of that muscle; the two are really separated
only by the transverse raphé, excepting that the ental layer of fibers
of the clavo-deltoideus arises from the ventral border of the clavicle
directly, or—near its scapular end—by short tendinous fibers.

Insertion.— At the ventral border of the antebrachium the
cephalic border of this muscle is firmly connected with the general
antebrachial fascia, and, at 8-10 mm. from the wlna, the muscle
joins the brachialis to be inserted with it, by a flat tendon, upon a
rough and sometimes slightly depressed area on the caudal aspect
of the ulna, just distad of the greater sigmoid notch, and about
midway between the dorsal and ventral borders. See § 693.

Remark.—By its origin this muscle seems to be a member of the deltoid group of
muscles, but its insertion associates it, functionally, with the flexors of the antebrachium,
When the clavicle is wholly absent, as with the horse, etc., the MM. clavo-deltoideus, clavo-
trapezius and clavo-mastoideus seem to form a single muscle, the cephalo-humeralis.

§ 639. Explanation of Fig. 72.—The pectoralis group of mus-
cles, partly dissected, seen from the ventral aspect. The neck is
toward the observer. The right and left of the figure correspond in
position with the right and left of the observer (§ 56).

Preparation.—The cat is dorsicumbent, resting upon the right
side more than the left. The figure includes the thorax and caudal
part of the neck, together with the arms to a little distad of the
elbows. The arms are pulled away from the trunk so as to put the
pectoral muscles upon the stretch. On the right side, the borders
of the muscles have been defined by the removal of the fat and con-

THE PECTORALIS GROUP. 233

nective tissue, and in some cases the ectal layers have been slightly
displaced. On the left the divisions of the ectopectoralis and pecto-
antebrachialis have been reflected, cut short or wholly removed ;
on this account the cephalic part of the mesal or interpectoral
raphé is drawn dextrad out of line with the caudal part, giving
a somewhat distorted appearance to the entire figure. The raphé
itself is too sharply defined.

This figure fairly illustrates the crossing of the pectoral elements which is commented
upon in § 641.

The figure represents the condition of things in the preparation from which it was
taken ; but in some respects, especially as to the marked subdivision of the caudal divi-
sion of the entopectoralis and the non-attachment of the ziphi-humeralis to the xiphister-
num, it hardly indicates the usual arrangement.

Bones, etc.—Cartilago—The first costicartilage (Fig. 30, 49)—The costal end of this
just appears on the left side.

Clavicula (§ 422).—The position of the left clavicle is nearly inverted with respect to’
its normal position, on account of the reflection of the clavicular end of the clavo-deltoideus.
From its mesal and lateral ends are strips of fascia or thin ligaments passing respectively
to the presternum and to the muscles upon the scapula. On the right side the sternal end
of the clavicle appears near the cephalic end of the mesal raphé.

Costa (Fig. 30).—Part of the first rib appears on the left side.

Epigastrium (§ 228).—The name is written across this region, just caudad of the xiphi-
sternum ; the space was vacated by the removal of the MM. rectus, ectobliquus and other
constituents of the abdominal parietes.

Trochin (Fig. 30, 46, § 420).—This, the ‘‘ lesser” humeral tuberosity, appears on the
left between the humeral ends of the caudal and cephalic divisions of the entopectoralis.

Xiphisternum (Fig. 49, § 426).—In some cases the 2iphi-humeralis is attached to nearly
the whole length of the narrower portion of this last sternal segment.

Muscles.—The following are not particularly described in this work ; sterno-hyoideus,
sterno-thyroideus, ectobliguus and rectus. The thoracic continuation of the last is shown in
Fig. 73.

Biceps (§ 691).—The distal part of this appears on both sides. On the left side its ten-
don (tendo bicipitis) may be seen just ventrad of the trochin.

Clavo-deltvideus (§ 651).—The right is but slightly displaced ; the left las been tran-
sected and reflected.

Clavo-mastoideus (§ 625) and clavo-trapezius (§ 615).—The edges of the clavicular delta
of these muscles are seen on the right side of the neck.

Dermo-humeralis (§ 629).—On the left side a fragment of this is seen chaiacted with
the latissimus.

Ectopectoralis, lm. ectalis (§ 649).—On the right this is partly hidden by the cephalic
division of the pecto-antebrachialis and the clavo-deltoideus. On the left it has been tran-
sected very near the meson, and the. humeral portion is reflected.

Eetopectoralis, lm. entalis, dv. caudalis (§ 653).—Only part of this appears on the right.
The humeral portion of the left has been reflected, and part of it removed so as to leave it
shorter than the dv. cephalica.

Ectopectoralis, lm. entalis, dv. cephalica (§ 651).—On the right it is entirely hidden by
the ectal lamina ; the left has been treated like the caudal division, excepting that the
reflected humeral end is left longer.

234 ANATOMICAL TECHNOLOGY.

Entopectoralis, do. caudalis (§ 656).—The right humeral portion is hidden. The left
was separable into two divisions.

Lntopectoralis, do. cephalica (§ 658).—On the right little of this is visible. On the left
it is almost wholly exposed.

Epitrochlearis (§ 681).—The left is entire, passing from the Jatissimus to the elbow,
where it is associated with the pecto-antebrachialis, On the right side is seen the reflected~
distal half.

M. epitrochlears

L -m.clavo-trapezcus
fraideus
-M. clavo-mastoideus

Fig. 72.—THE PECTORALIS GROUP OF MUSCLES, PARTLY DISSECTED.

Latissimus (§ 635).—A fragment of the right is visible. The left has the appearance
of passing ectad of the biceps ; in reality, however, most of it passes entad of the biceps,
and what appears to be the continuation of the datissimus is the tendon of the POS
ralis which passes entad of the caudal division of the entopectoralis.

Pecto-antebrachialis, dv. cephalica (§ 646), dv. caudalis (§ 647).—These are shown entire
on the right, but on the left they have been removed excepting the distal ends.

Sterno-mastoideus (§ 622).—The sternal ends of both are shown, including the mesal
raphé formed by the interdigitation of their fibers.

Supinator longus (§ 690).—Part of this appears on the right.

Supraspinatus (§ 675).—This is more fully shown in Fig. 73, 74.

PECTORALIS GROUP. 235

Triceps (§§ 687-689).—The caudal or ectal aspect of the entutriceps appears on both‘
sides, but the divisions are not defined.

Xiphi-humeralis (§ 660).—On the right the sternal part is shown but not named. On
the left, its course entad of the entopectoralis is indicated by the broken lines, and part of
its humeral end is seen. Usually this muscle is more intimately connected with the
xiphisternum. ;

PECTORALIS GROUP.

§ 640. General Remark.—The two pectoral muscles of man,
ectopectoralis, ‘‘ pectoralis major,” and entopectoralis, “‘ pectoralis
minor,’ are represented in the cat by several muscles to which
Straus-Durekheim and others have applied distinct names. Most
of these divisions, however, may be recognized as parts of two
masses, an ectal or superficial, arising nearer the cephalic end of
the sternum, and extending laterad to the diaphysis of the hume-
rus, and an ental or deep, arising from the caudal part of the ster-
num, and extending latero-cephalad to the head of the bone. The
former, representing the ectopectoralis, tends to subdivide into
superposed lamine ; the latter, representing the entopectoralis,
tends rather toward a division into parallel fasciculi. See § 572,
Humphrey, B, 110, and Wilder, 20, 306.

§$ 641. Crossing of the Pectoral Hlements.—Excluding the M. pecto-antebrachialis,
which is inserted upon the antebrachium, the pectoral mass may be roughly described as
a series of four superposed laminz crossing one another in such a way that the cephalic in
origin is distal in insertion, while the caudal in origin is proximal in insertion.

The ectal lamina of the MU. ectopectoralis (Fig. 72) arises from the presternum and ceph-
alad of it, and is inserted upon the middle third of the humerus. The ental lamina, asa
whole, arises from the cephalic third of the sternum, and is inserted upon the proximal
three fifths. The MU. entopectoralis, as a whole, arises from the entire mesosternum, and is
inserted upon the proximal third. Finally, the M. ziphi-humerailis arises from or near the
xiphisternum, and is inserted upon the head and neck of the humerus.

It follows from this arrangement that the general direction of the fibers of the first por-
tion is nearly transverse ; that, in the natural attitude of the arm, for a part of their course
at least, the fibers of the last portion run nearly parallel with the meson ; while the direc-
tions of the other two portions are intermediate. .

A somewhat similar relation exists between the less distinctly separable regions of the
human ectopectoralis as described by Gray (A, 400) and Quain (A, I, 198).

The insertion lines of the two lamine of the ectopectoralis are nearly parallel, but
almost meet at their distal ends (Fig. 69). If they were continuous, they might be de-
scribed as a single line folded upon itself, and their tendons would be strictly comparable
with the tendon of the human pectoralis major as described by Gray and Quain.

§ 642. The Pectoral Complexity—In the cat there may be recognized eight or nine
“ elements of the pectoral mass, more or less independent as to origin or insertion or both.
In man, the M. entopectoralis (P. minor) is distinct, and the V. ectopectoralis is more or
less readily in different subjects separable into two or three portions, whose origins and
insertions, however, are nearly or quite continuous.

It may be said, therefore, that the provision for separate and independent movement

236 ANATOMICAL TECHNOLOGY.

by means of the pectoral muscles is twice as great in the catas in man. This will hardly
surprise those who have watched a kitten at play, or a cat in any kind of vigorous action.
It must be remembered, however, that this superior complexity of the muscles acting upon
the brachium, and thus upon the limb as a whole, does not confer peculiar powers upou
the distal segment, and no one would regard the cat’s manus as equal to that of man. In
the quadruped, the specialization is proximal and the distal parts are relatively simple;
with the bimanous biped, the muscles acting upon the arm as a whole are comparatively
simple and in what may be regarded as a generalized condition, but the projection of the
brachium from the thorax confers great freedom of movement, while the distal muscles
are more distinct and independent than in the cat.

Those who are disturbed that any parts of a cat should be described as more complex
than the corresponding human organs should compare the stomach and brain of man with
the same parts of the pig, sheep and porpoise.

§ 643. Caution.—Excepting the muscles especially related to
the vertebral column, there are probably none more difficult of dis-
section than the pectorales. This is due in part to the number and

extent of the individual variations which have so far made it impos-
sible to provide directions to meet all cases, but chiefly to the
intrinsic complexity of superposition and attachment.

The student should proceed with great caution, follow the direc-
tions and descriptions as closely as possible, repeat the dissection
upon the opposite side, and make careful notes and drawings of all
peculiarities.

§ 644. Exposure.—As with the trapezius group, it is usually
more convenient to expose all of the pectorales by lifting a single
flap of skin.

Connect the antebrachial end of the incision made in exposing
the clavo-deltoideus with the free border of skin left in exposing the
dermo-humeralis and latissimus, or with the epigastriwm (Fig. 72).
Begin with the skin already raised from the ventral aspect of the
brachium, and reflect the flap just circumscribed across the ventri-
meson. ‘To cut as nearly as possible in the direction of the fibers,
the flap may be grasped at first by the angle near the shoulder, but
later by its caudal margin. Great care must be taken to avoid
injuring the subjacent muscles.

M. PECTO-ANTEBRACHIALIS.

§ 645. Synonymy.— Pecto-antébrachial,” S.-D., A, I, 352 ; “ sterno-aponéurotique,”
Ch., A, 247 ; sterno-aponeuroticus, Ch. (F1.), A, 232 ; part of “ pectoralis, part 1,” Miv., B,
145; not normally represented in man.

Figures.—Ectal aspect of both divisions (72, right side ; distal ends (72, left side).

General Description.—In two divisions, cephalic and caudal,
from the median raphé at the presternum and 3d mesosterneber

M. PECTO-ANTEBRACHIALIS. 237

respectively, to the dorsal border of the antebrachium near the
elbow.

Posture.—Dorsicumbent, the head toward the dissector ; a block
under the shoulders so that the head and neck hang down.

§ 646. Dv. Cephalica.—Dissection.—The cephalic border has
been indicated during the dissection of the clavo-deltoideus, to
which it is attached excepting at the ends. Trace it for 2-3 cm.
both ways from the middle. Then feel upon the meson, about
3 em. from the tip of the preesternum, for the elevation corresponding
with the first sternal node, or for the attachment thereto of the sec-
ond costicartilages. Laterad from that point runs a white line,
which marks the caudal margin of the muscle. Toward this line
dissect up the muscle from its cephalic border, at about the mid-
dle of the length of the latter, and transect.

In reflecting the mesal part of the muscle, note its close attach-
ment to the subjacent ectopectorolis, and that it joins its platetrope
by a median raphé. The distal part of the muscle is much more
easily separable from the subjacent muscle, but, about 1 cm. ven-
trad of the level of the antebrachium, its caudal border is joined
by the caudal division of the muscle. At this point the muscular
fibers of both divisions are replaced by tendinous fibers.

The tendon thus formed seems to be continuous with the general
antebrachial fascia, but, if this fascia be divided along a line cor-
responding with the cephalic border of the muscle, the tendon may
be traced across the caudal surface of the antebrachium and found
to terminate upon the dorsal aspect of the ulna. The examination
of the details of the insertion may be deferred until after the dissec-
tion of the caudal division.

Origin —From a median raphé common to it and its platetrope,
and extending the whole length of the presternum, excepting,
sometimes, its caudal or cephalic 1-2 mm.

Insertion.—By tendinous fibers along the distal third of the
oblique caudal border of the subcutaneous surface near the proxi-
mal end of the dorsal aspect of the ulna. The cephalic border of the
tendon is closely attached for part of its length to the caudal border
of the clavo-deltoideus, and its caudal border is continuous with the
fibers forming the tendon of the caudal division of the muscle.

§ 647. Dv. Caudalis.—Posture and Exposure as with the
cephalic division. The muscle is very slender and closely attached

238 ANATOMICAL TECHNOLOGY.

to the neighboring muscles, so that its isolation is not always easy.
Sometimes it is absent altogether.

Dissection.—The distal part of the cephalic border has been
indicated as united with the caudal border of the cephalic division.
It is here 1.5-3 mm. wide, but widens gradually as it crosses the
axilla and nears the meson.

At 3-5 cm. from the meson, it leaves the border of the RE
division, and becomes attached with equal closeness to the caudal
border of the ental lamina of the ectopectoralis, which it accompa-
nies, until it reaches the meson at the 8d mesosterneber, about the
middle of the length of the sternum, exclusive of the xiphisternum.

§ 648. Origin —By very short tendinous fibers, from the meson
of the 3d or 4th mesosterneber, just caudad of the origin of the ental
layer of the ectopectoralis. Sometimes the origin on one side is
just caudad of that on the other. At the meson its width is 10-15

m.; but it narrows greatly toward the distal end. The caudal
border of the distal end is connected with the epitrochlearis.

M. ECTOPECTORALIS.

§ 649. Synonymy.—The human pectoralis major, G., A, 899; Q., A, II, 193 ; ‘‘ large
pectoral,” 8.-D., A, I, 342.
Exposure.—By the reflection of the MM. clavo-deltoideus and pecto-antebrachialis.

LAMINA ECTALIS.
Synonymy.—* Le premier chef du large pectoral,” §8.-D., A, 1, 348 ; pectoralis, part 2,
(in part), Miv., B, 146.
Figures.—Part of ectal aspect (72, right side) ; ental aspect of humeral end (72, left
side) ; insertion line (68, 69). °

General Description.—W ide, teniate, from the dorsimeson, at
and cephalad of the presternum, to the middle third of the ventral
border of the humerus.

Dissection.—The caudal border extends almost directly laterad
from the presterno-mesosternal node, where its mesal end underlies |
the mesal end of the caudal border of the cephalic division of the
M. pecto-antebrachialis. Liftit with great care at about the middle.

The cephalic border lies nearly parallel with the caudal, at a
distance of 2-3 cm., and extends almost directly laterad from the
point where the caudal end of the sterno-mastoideus (Fig. 72) passes
entad of the pectoral mass. In well-injected specimens this border
is indicated, at about the middle of its length, by the disappear-
ance, entad of it, of an artery which has emerged from the thorax
and curved over the cephalic border of the pectoral mass.

M. ECTOPECTORALIS. 239

Lift the cephalic border at its middle and relax the parts so as to
permit dissection entad of the muscle from one border to the other ;
then transect.

In reflecting the mesal end of the muscle, cut an artery and
nerve which emerge from the subjacent ental layer, and note that,
near the meson, the cephalic border curves cephalad. The ental
surface of the lateral part of the muscle is often so closely joined
with the subjacent muscle that there is danger of cutting fibers.
The tracer should be used in tearing the connective tissue until the
bone is reached.

§ 650. Origin—From a median raphé common to it and its
platetrope ; the caudal half or three fifths of the raphé is attached
to the presternal keel, the remainder is continuous with the line of
union of the caudal portion of the IZM. sterno-mastoidei.

Insertion..—The middle of the length of the line of insertion cor-
responds closely with the middle of the length of the humerus, but
the insertion includes rather more than a third of the length of the
bone. Its distal end is almost in line with the middle of the distal
end of the bone, but its proximal end is nearly midway between
the ventral and cephalic aspects. The caudal border of the line of
insertion is well defined, but the cephalic is not so clearly separable
from the insertions of the spino-deltoideus and brachialis, and a
strong fascia sometimes extends proximad from the border of the
muscle toward the trochiter.

LAMINA ENTALIS, DV. CEPHALICA,
§ 651. Synonymy.—*‘ Le second chef du large pectoral, sa partie antérieure,” 8.-D.,
A, II, 348 ; pectoralis, part 5, “ subclavieular part,” Miv., B, 147.

Figures.—Sternal end (72, left side) ; humeral end, reflected (72, left side) ; insertion
area (68, 69).

_ General Description.—Narrower and thicker than the ectal
layer; 15-18 mm. wide; from the presternum and raphé to the
proximal fourth of the cephalic side of the humerus.
Dissection.—The artery and nerve mentioned (§ 649) as passing
from the ental to the ectal layer of the ectopectoralis usually pene-
trate the former through a narrow interval about one third of the
distance from the meson to the humerus. This interval usually
marks the line of separation between the cephalic and caudal divi-
sion of the ental lamina of the ectopectoralis. Mesad of the inter-
val, the plane of separation is at a right angle with the surface of

240 ANATOMICAL TECHNOLOGY.

the muscle, but laterad of it the plane becomes oblique, with a
dorso-cephalic direction which is more marked nearer the humerus.
Transect by an ecto-ental incision opposite the artery.

In reflecting the sternal part, note the close union of the ental
surface near the meson with the ectal surface of the sterno-mastoi-
deus. In reflecting the humeral part, note that, excepting at the
caudal border, the muscular fibers cease along the ventral margin
of the trochiter.

§ 652. Origin.—The caudal two thirds is from the lateral sur-
face of the preesternum cephalad of the attachment of the first costi-
cartilage ; the cephalic third from the median raphé and from the
ectal surface of the sterno-mastoideus.

Insertion.—Along a curved line upon the cephalic surface of the
proximal fourth or fifth of the humerus (Fig. 68, 69). The line of
insertion begins 3-4 mm. proximad of the proximal end of the inser-
tion of the ectal lamina, and sometimes very slightly ventrad of it.
The distal two thirds of the line extend dorso-proximad to a point
just ventrad of the slight elevation (Zbcl. micostale, see M. mico-
stalis), distad of the Fs. trochiteriana (Fig. 45, B), where it usually
turns slightly ventrad so that the proximal third forms an angle of
20-30 degrees with the rest. The line ceases about 3 mm. from the
proximal border of the trochiter at the edge of the insertion of the
M. supraspinatus.

LAMINA ENTALIS, DV. CAUDALIS.
§ 653. Synonymy.—‘ Le second chzf du large pectoral, sa partie postérieure,” S.-D.,
A, I, 348 ; pectoralis, part 2 (in part), Miv., B, 146.

Figures.—Part of ectal aspect (71, right side) ; humeral end, reflected (72, left side) ;
insertion line (69).

General Description.—The widest and longest portion of the
ectopectoralis, excluding of course the pecto-antebrachialis ; from
the cephalic part of the sternum to the second and third fifths of
the ventral border of the humerus.

Dissection.—The cephalic border has been indicated during the
dissection of the cephalic division, and the caudal border during the
dissection of the caudal division of the pecto-antebrachialis. Lift
both borders, but dissect up the middle of the muscle from the
cephalic toward the caudal border, using the tracer and the handle
of the scalpel so as to avoid cutting the subjacent muscles; then
transect, and reflect both ends until bone is reached.

M. ENTOPECTORALIS. 241

§ 654, Origin.—By fleshy fibers, from the lateral border of the
presternal keel, and from the first mesosterneber and part of the
second, thus filling the interval between the origin of the cephalic
division and that of the pecto-antebrachialis, dv. caudalis.

Insertion.—Along a line occupying, approximately, the second
and third fifths of the ventral border of the humerus, thus ventrad |
of the lines of insertion of the cephalic division, and of the ectal
lamina. The insertion is somewhat variable in detail, but a simple
form is the following: The cephalic half continues fleshy to the
bone, while the caudal half is inserted by a thin tendon 3-7 mm.
long. The proximal end of the line of insertion is nearly opposite,
but 2-3 mm. ventrad of, the distal end of the line of insertion of the
cephalic division, and the distal end is close to the distal end of the
line of insertion of the ectal lamina.

M. ENTOPECTORALIS.

§ 655. Remark.—The remainder of the pectoral mass forms at least three divisions
which are sufficiently distinct in origin or insertion to warrant separate descriptions, but
which, perhaps, are all parts of what may be regarded as a large representative of the
“ nectoralis minor” of man (§ 572).

These muscular divisions are very variable in number, form, connection with each other
and osseous attachment. In respect to size there are marked differences between individ-
uals ; in young or feeble cats, the masses may be not only thin, but more or less subdivided,
while in adult or robust animals, they are sometimes almost continuous with each other.

Exposure.—So much.-as was not concealed by the I. ectopecto-
ralis is covered by a dense layer of connective tissue which must
be removed.

DV. CAUDALIS.
§ 656. Synonymy.—‘Le premier chef du grand pectoral,” §.-D., A, II, 841 ; pectoralis,
part 3 (in part), Miv., B, 147.

Figures.—The ectal aspect (72, both sides); humeral end, reflected (78) ; insertion
line (69, 70).

General Description.—A thick band, from the 6th mesosterne-
ber and sometimes the zviphisternwm to the proximal half or two
jifths of the ventral border of the humeral diaphysis.

Dissection.—The line of separation between the cephalic and
caudal divisions is about midway of the width of the whole mass,
at about 3 cm. from the humerus; it coincides nearly with a line
drawn from the surgical neck of the bone in the direction of the
fibers of the muscle. The degree of separation varies greatly, and

16

242 ANATOMICAL TECHNOLOGY.

sometimes one or both of the divisions show signs of subdivision.
In the specimen figured (Fig. 72), the cephalic division presents two
well-marked subdivisions.

Near the humerus the interval between the two divisions is
usually wide, but toward the sternum the cephalic border of the
caudal overlaps the caudal border of the cephalic division, and
sometimes their separation cannot be effected without cutting fibers. -
At the sternum, however, the overlapping sometimes hardly exists.

The caudal border has been exposed during the dissection of the
latissimus and dermo-humeralis, whose humeral ends are connected
with this muscle at the bicipital arch (Fig. 73); but the sternal half
of this border is closely united with the cephalic border of the
ziphi-humeralis, which it overlies in its humeral half. The ziphi-
humeralis may be recognized by its loose and wide origin at the
epigastrium. Carefully disengage the two muscles at their crossing,
then transect the caudal division of the entopectoralis.

§ 657. Origin.—By fleshy or short tendinous fibers from the
border of the last 2 or 3 mesosternebree, and sometimes from the
cephalic part of the xiphisternum, and from the intervening nodes.

Insertion.— Variable and complex, and not easily described,
excepting in connection with the other elements of the bicipital arch.
At about 3 cm. from its attachments to the ventral border of the
humerus the caudal border is connected with the /atissimus, and its
ental aspect, along an oblique line passing proximo-cephalad, is
sometimes united with the thin tendon of the ziphi-humeralis. For
the sake of distinctness, this union may be severed close to the
ental surface, some fasciz passing from the caudal border of the
tendon to the surface of the M. biceps may be removed, and the
extent of the true insertion may be seen more distinctly.

Like that of the caudal division of the ental layer of the ecto-
pectoralis, the insertion is partly muscular and partly tendinous.
The line of attachment is about 3 cm. long, and extends from the
base of the trochiter along the ventral border of the humerus to a
point.near the junction of the second and middle fifths of the length
of the whole bone, and opposite the junction of the muscular and
tendinous parts of the insertion of the caudal division of the ental
lamina of the ectopectoralis. The proximal third or two fifths of the
insertion is fleshy, the rest is a thin tendon about 1 cm. long.

M. ENTOPECTORALIS. 243

DV. CEPHALICA,
§ 658. Synonymy.— Sterno-trochitérien,” 8..D., A, Il, 337; pectoralis, part 3 (in
part), Miv., B, 147.
Figures.—Ectal aspect (72, left side); humeral end, reflected (73) ; insertion area (68,
69, 70).

’ General Description.—A thick band, much widened at the
sternum ; from ali the mesosternebra, excepting the first and sixth
—or fifth and sizth—and from the intervening and terminal nodes,
to the head of the humerus.

Exposure.—Both borders have been exposed, the cephalic by
the reflection of the ectopectoralis, the caudal by the reflection of
the caudal division of the enfopectoralis.

Dissection.—The humeral end must be reflected with great care,

and the preliminary examination should be made with the tracer
rather than with the scalpel. Particular pains should be taken to
avoid cutting or breaking a slender tendon which sometimes extends
from the cephalic border, close to the humerus, to the coracoid
process of the scapula (Fig. 73, Zn. z.).
' The ectal fibers of the muscle cease at the swpraspinatus, and
seem to be inserted upon it, but the coracoid margin of the latter
muscle may be dissécted up for 1-5 mm.; there will be exposed
a tendinous continuation of the entfopectoralis, which, as to its
cephalic half, cannot be separated farther from the tendon of the
supraspinatus without cutting the tendinous fibers.

§ 659. Insertion.—At the border of the overlapping swpraspi-
natus the fleshy part of the present muscle is replaced by a tendon
which is attached to the caudal aspect of the trochiter, and along its
ventral border ; this attachment is in line with the insertion of the
caudal division, and terminates 1-2 mm. from its proximal end.
The caudal half or third of this tendon is thin; the rest is thick and
fused with the ental surface of the tendon of the swpraspinatus so
that the respective areas of attachment can be ascertained only
approximately. The latter muscle, however, is on the ectal side,
and occupies the crest and cephalic aspect of the trochiter.

In addition to the tendon of direct insertion, a slender band
sometimes extends from the cephalic border, just at the junction of
the muscle and the tendon, and is attached to the border of the
coracoid process between its tip and the prominent coracoid lip of
the glenoid fossa. This tendon probably represents the coracoid

244 ANATOMICAL TECHNOLOGY.

insertion of the entire entopectoralis in some monkeys and—more
commonly—in man. As to the frequency of the humeral insertion
of the human J. entopectoralis, see Macalister, Proc. Roy. Irish
Acad., X, 142.

M. XIPHI-HUMERALIS.

§ 660. Synonymy.— Le second chef du grand pectoral,” 8.-D., A, I, 341 ; pectoralis,
part 4, Miv., B, 147.
Figures.—Part of ectal aspect (72); humeral end, reflected (73) ; insertion spots (69).

Exposure.—By the reflection of the other portions of the pec-

’ toral mass.

General Description.—The longest and most slender member
of the pectoralis group ; from the median raphé at the epigastrium
to the proximal end of the humerus. The length of the cephalic
border is sometimes 20 cm., while the width at the middle is only
4mm.

Dissection and Origin.—The caudal border was exposed during
the dissection of the WM. latissimus and dermo-humeralis ; the

cephalic border during the dissection of the caudal division of the .

M. entopectoralis. Transect the muscle near the middle.

In reflecting the proximal part, note that, 1-2 cm. from the
meson, the loose connective tissue between it and the thoracic parie-
tes is sometimes replaced by a firm tendinous attachment to the 8th
costal cartilage and to the fascia covering the IZ. rectus ; the mus-
cular fibers cease at about the same point, and the thin, wide tendon
is connected with its platetrope by a median raphé, the position of
which, as regards the xiphisternum, is quite variable.

§ 661. Insertion.—The humeral connections are complex and
variable. In passing the latissimus, it is usually connected, by
tendinous fibers, with the ental surface of that muscle, then, indi-
rectly, with the entopectoratis and the other elements of the dicipital
arch. Just beyond this connection the narrow muscle is replaced
by a tendon which usually widens as it nears the humerus. In the
broad sheet so formed may usually be detected three more or less
distinct bands with attachments as follows (Fig. 66, 71, 73): (A)
upon the bicipital border of the trochin, just cephalad of the inser-
tion of the WZ. subscapularis ; (B) and (C) just caudad of the inser-
tions of the cephalic and caudal divisions of the entopectoralis. As
a whole, therefore, the tendon spans the bicipital groove.

BICIPITAL ARCH. 245

ARCUS BICIPITALIS—THE BICIPITAL ARCH (Fig. 78).

§ 662. This name is given to the tendinous arch through which
passes the Jf. biceps (Fig. 73, 75). In man, normally, the ectopecto-
ralis passes ectad of the biceps, while entad of it pass the tendons of
the latissimus and teres. In the cat, as in the Mammals generally,
there is a union of the ental with the ectal muscles so as to form a
complete arch over the biceps. The ectal, or cephalic, pillar of the
arch is formed by the caudal division of the entopectoralis; the
ental, or caudal, pillar, by the ¢eres and latissimus, while the
riphi-humeralis and dermo-humeralis are connected with one or the
other pillar, with the muscles composing them, or with the convex-
ity of the arch itself.

Explanation of Fig. 73.—The ental aspect of the muscles about
the left shoulder, and the ectal aspect of the JZ. serratus magnus
and levator anguli scapule. ;

Preparation.—After the dissection and reflection or removal of
the muscles of the trapezius and pectoralis groups, and of the other
muscles already described as connecting the soma with the arm and
shoulder girdle, the arm and scapula were turned dorsad.

Certain muscles (scaleniz) not described herein have been wholly
removed from the neck and cephalic part of the thorax, and of the
M. ectobliquus (abdominis) there is left little more than the first six
digitations. There are thus exposed the I. rectws with its wide,
thin tendon, and parts of the costal cartilages 7-8, with the inter-
vening IZM. intercostales.

Bones, etc.— Arcus bicipitalis, with its cephalic and caudal pillars (Clm. cephalica and
caudalis)—The bicipital arch (§ 662).—This is seen to embrace the WM. biceps. There is
considerable variety in the mutual relations of its constituents. In the preparation fig-
ured, the M. /atissimus might be said to enter into the composition of both pillars, and the
M. dermo-humeralis does not directly reach the arch at all.

Costa and cartilago (§§ 441, 442).—The first rib is exposed and the name is written
thereon. The sternal ends of the eighth, ninth,and tenth ribs are seen near the cut bor-
der of the M. ectobliquus. The first costicartilage affords insertion to the tendon of the ¥.
rectus, and parts of the seventh to the tenth appear between the margins of the MM. rectus
and ectobliquus ; elsewhere their position is indicated by dotted lines.

Diapophyses cervicales—The transverse processes of the cervical vertebre (§ 481).—
These are numbered 1-7, but no name has been written near them. Note the gradual
increase in the extent of their bifurcation toward the caudal end of the series.

Pre. (Processus) coracoideus—The coracoid process of the scapula (Fig. 48, 44, 45 A;
S$ 389, 400).

246 ANATOMICAL TECHNOLOGY. a

Tn. x.—The tendinous slip from the border of the cephalic division of the M. ectopecto-
ralis to the coracoid process (§ 659).

Trachea—windpipe (Fig. 89)—The transverse lines indicate merely the general
appearance of this tube, and not the number of its rings,

Xiphisternum (Fig. 49, 72, § 426).

Mace

Fie. 73.—ENTAL ASPECT OF THE LEFT SHOULDER MUSCLES, AND EcTAL ASPECT OF
THE MM. SERRATUS-MAGNUS AND LEVATOR ANGULI SCAPULZ.

Muscles.—The following are not particularly described ; the numbers placed after the
names designate the other figures in which they appear :—

Splenius (67) ; sterno-thyroideus (72); rectus (72) ; ectobliquus (72) ; intercostalis.

Biceps (§ 691).—The proximal tendon is seen passing entad of the ligament which
spans the Canalis bicipitalis (Fig. 46 and 45, B), and emerging again nearer the Pre. cora-
coideus ; it is not, however, inserted into it, but upon the Tuberculum bicipitale (Fig. 45, A).

Ooracoideus (3 668).—Only the caput breve is seen, arising from the coracoid process
and passing to the neck of the humerus. The caput longum appears in Fig. 75.

M. SERRATUS MAGNUS. 247

Dermo-humeralis (§ 629).—A part of this is seen to pass to the ectal aspect of the W.
latissimus.

Entopeetoralis, dv. caudalis (§ 656).—As in Fig. 72, which was taken from the same
preparation, this division presents a well-marked subdivision.

Entopectoralis, dv. cephatica (§ 658).—Thicker than the caudal division, this is inserted
chiefly upon the trochiter, but here, as in some other cases, a slender tendon (7'n. a.) passes
to the coracoid process.

Latissimus (§ 635).—The ectal aspect was presented in Fig. 66 and 67; here are seen
the ental surface and its connections with the arcus bicipitalis and the M. teres.

Levator anguli seapule (§ 666).—The general appearance of the muscle is fairly indi-
cated, but the removal of the other soft parts from the line of origin has given the proxi-
mal end the look of having been cut off. The proximo-cephalic angle also extends some-
what too far cephalad. The interval between it and the serratus magnus was artificially
produced. The two muscles are evidently parts of the same general muscular lamina, but
there are sufficient practical reasons for treating of them separately.

Sterno-mastoideus (§ 622).—This is better shown in Fig. 72.

Subscapularis (§ 670).—Especially noteworthy are the appearances of its continuity
with the adjacent muscles, serratus magnus, levator anguli scapula, teres and supraspina-
tus. Its tendon of insertion is crossed by the coracoideus.

Supraspinatus (§ 675).—Between this and the humeral part of the subscapularis is the
triangular interval mentioned in the dissection of the coracoideus (§ 668).

Teres (§ 680).—As in the other figures, the word major has been inadvertently added.

Xiphi-humeralis (§ 660).—The humeral end is reflected like the two divisions of the
entopectoralis.

Occipito-scapularis (§ 617).—Its ventral margin is seen to thicken caudad.

M. SERRATUS MAGNUS.

§ 664, Synonymy.—The human serratus magnus, G., A, 402, Q., A, 1, 196 ; “grand
dentelé” [thoracic portion], 8.-D., A, Il, 335 ; grand dentelé, Ch., A, 250 ; great serratus,
Ch. (FI.), A, 236 ; serratus magnus, Miv., B, 145.

Figures.—Ectal aspect (73) ; scapular end (75); insertion area (48).

Posture.—Latericumbent; the venter toward the dissector ;
block transversely under the thorax just caudad of the elbows.

Exposure.—F or the complete exposure of this muscle it is neces-
sary to reflect all the muscles thus far enumerated, excepting the
sterno-mastoideus ; also to remove the larger part of the thoracic
portion of the IZ. ectobliquus ‘external oblique muscle of the
abdomen ’”’ (Fig. 73), and to remove or partly displace the thoracic
portion of the JZ. rectus and some other muscles upon the cephalic
region of the thorax.

Lift the elbow so that the brachium rests at a right angle with
the side of the neck. Dissect out the fat and connective tissue thus
exposed between the shoulder and scapula and the thorax, then
divide and reflect the axillary vessels and nerves. This will permit
the whole arm, with the scapula, to be turned dorsad so as to expose

248 ANATOMICAL TECHNOLOGY.

the lateral wall of the thorax. Sometimes there will be found a
slender muscle extending from the muscles covering the ventral
surface of the cervical vertebree to the J. teres which lies along
the glenoid border of the scapula.

General Description.—A thick, trapezoidal muscle, from all
the ribs and cartilages, excepting the last 3 or 4, to the caudal
three fifths of the vertebral border of the scapula. Its cephalic bor-
der is continuous with the caudal border of the levator anguli scap-
ule, with which, indeed, it seems to form a single muscle. The
independence of the two muscles in man results from the absence of
so much of the lev. ang. scap. as—in the cat—arises from the last
three cervical vertebra.

Dissection.—Near the vertebral end of the first rib note the
. emergence of an artery and nerve. Extending caudad from this
point note the slightly raised border of a long, flat muscle, one of
the Scaleni ; divide this at the fourth rib, and reflect the two ends,
to the 9th or 10th costal cartilage and to the cervical muscles re-
spectively. Nearer the ventrimeson lies another, and wider, ribbon-
shaped muscle, the rectus thoracis, the thoracic continuation of the
rectus abdominis. Reflect this muscle, together with the strong
fascia between it and the ventrimeson, cephalad as far as the 1st
rib, and caudad to the 9th or 10th.

Now turn the arm ventrad so as to expose the ental surface of
the combined serratus magnus and levator anguli scapule. Dis-
sect up, or divide, the rather dense fascia which extends from the
dorso-caudal and dorso-cephalic borders upon the neck and thorax.
Lift the arm from the thorax so as to put the whole muscle upon
the stretch, and examine the ectal surface along a line extending
from the point of emergence of the artery and nerve above men-
tioned—corresponding with the vertebral attachment of the first
rib—to the vertebral border of the scapula at or near the junction
of its coracoid and middle thirds, and opposite the vertebral end
of the mesoscapula.

If, along this line, runs the principal branch of the artery, the
division of the entire mass into a caudal part, the serratus magnus,
and a cephalic part, the levator anguli scapula, can usually be
made without cutting many fibers ; but in some cases it may be bet-
ter to leave the muscles connected. Note, in either case, that the
M. serratus presents, in its thoracic half, divisions corresponding to
the ribs, while the other muscle is continuous.

M. SERRATUS MAGNUS. 249

Divide the connective tissue, sometimes quite firm, which unites
these subdivisions, and then transect the muscle itself along a curved
line about 3 cm. from the scapula. For greater ease of examining
- the attachments of the subdivisions, continue the interval just cau-
dad of the 4th rib to the cut edge of the muscle. In reflecting the
two parts thus formed, note the passage of nerves and vessels to
them from the intercostal spaces. The muscle is usually tender,
and the tracer should be used rather than the knife in clearing
away the connective tissue at the attachments of the subdivisions.

§ 665, Origin.—A line drawn through all the origins describes
about the fifth of a cirele, extending from the middle of the 1st rib
to the middle of the 9th or 10th. The 4th subdivision extends almost
directly dorsad, the first and last extend dorso-caudad and dorso-
cephalad respectively, while the intermediate ones vary in direction
according to position.

The first subdivision arises from the 1st rib along nearly or quite
the whole of its caudal border; toward the sternal end it is over-
lapped to some extent by the attachment of the scalenuws above
mentioned ; the 2d, from the 2d costal cartilage 1-2 mm. from its
union with the rib, and sometimes by a short tendon; the 3d and
4th, from similar points upon their respective ribs or just at the
point of union of the ribs and cartilages; the 5th, at the point of
junction ; the 6th, 7th and 8th, from their respective ribs, at grad-
ually increasing distances from their junctions; the 9th, at about
2 cm. from the junction. The lines of attachment of the first and
the last coincide very nearly with the axis of the ribs; those of the
next four are nearly at right angles, while those of the remaining
three are oblique. A 10th subdivision, from the 10th rib, some-
times occurs. It should be carefully looked for.

Insertion.—The scapular attachment is continuous, but in two
parts: (A) the caudal two to three fifths is by a short tendon along
the ental edge of the vertebral border of the scapula; (B) the
remainder is by fleshy fibers upon a triangular area near the ver-
tebral border of the subscapular fossa, 10-15 mm. long and 4-8 mm.
wide. The wider end of this attachment is opposite the vertebral
end of the mesoscapula, and is continuous with the insertion of the
levator anguli scapule.

250 ANATOMICAL TECHNOLOGY.

M. LEVATOR ANGULI SCAPULZ.

§ 666. Synonymy.—The human levator anguli scapula, G., A, 376, Q., A, I, 192;
“grand dentelé” [the cervical portion], 8.-D., A, II, 335; angulaire de ?omopiat,, Ch., A,
202 ; angulur muscle of the scapula Ch. (F1.), A, 189; levator anguli scapule, Miv., B, 145.

Figures.—Ectal aspect (78) ; scapular end (75) ; insertion area (48).

Posture and Exposure.—These are the same as with the serra-
tus magnus, excepting that the block may be under the neck, and
the muscles (scalenz) covering the series of ventral tubercles of the
diapophyses of the cervical vertebree (Fig. 53) must be removed.

General Description.—Thick, trapezoidal, just cephalad of the
M. serratus magnus, from the diapophyses of the 3d-7th cervical
vertebre to the subscapular surface of the scapula close to the
vertebral border.

Dissection.—After the division of the serratus magnus, this
forms the only union between the arm and the trunk. Note its
compactness as compared with the muscle just named, although
sometimes the vertebral end shows signs of subdivision. Transect
it at the middle. ,

§ 667. Origin.—By fleshy fibers from the rounded ends of the
dorsal tubercles of the transverse processes of all the cervical verte-
bree excepting the atlas and axis, and from the ligaments between
the tubercles. Entad of the attachment will be seen the shining
tendons of the A. plagio-antobliquus cervicalis. The line of
origin is about 6 cm. long.

Insertion.—The scapular attachment is by fleshy fibers upon a
triangular area about 15 mm. long by 5-10 mm. wide (Fig. 43). This
area is continuous with the area of insertion of the serratus mag-
nus, but the apex points in the opposite direction, that is, toward
the coracoid border of the scapula. The ental surface sometimes
receives the insertion of the occipito-scapularis (§ 617).

Remark.—The arm, with the scapula attached, has now been separated from the trunk,
and may be dissected on a smaller tray. After reviewing the insertions of the muscles so
far examined, the dissector may remove them to within 1-2 cm. of their attachment.

M. CORACOIDEUS.

§ 668. Synonymy.—The human coraco-brachialis, G., A, 407, Q., A, I, 204; ‘‘ coraco
brachial,” $.-D., A, Il, 343 ; “ coraco-brachial,” Ch., A, 268 ; coraco-humeralis Ch. (F1.), A,
254; coraco-brachiaiis, Miv., B, 148.

Figures.—Caput breve (73); caput longum (75) ; insertion areas (70, 71).

'

M. CORACOIDEUS. 251

Posture.—The brachium forms nearly a right angle with both
the scapula and the antebrachium. Place the arm upon its cephalic
surface, let the antebrachium and manus rest against the rim of the
tray toward the dissector, and place a block flatwise under the
scapula and shoulder so that the brachium forms an angle of about
45 degrees with the tray.

Exposure.—Remove the fascia, fat, connective tissue, vessels
and nerves upon the caudal aspect of the shoulder and brachium.
In doing this, watch very carefully for the slender tendon (of the
caput longum, Fig. 75), which extends, in some cases, nearly the
whole length of the brachium; use the tracer more than the knife,
and remove nothing until sure that the tendon is not included.

General Description.—This muscle consists of two parts (caput
longum and cp. breve), so distinct that, if they were larger, they
probably would be regarded as two muscles (§ 573). They arise
from the coracoid process of the scapula and are inserted into the
humerus near its proximal and distal ends. Both parts are so
small as to be easily overlooked.

Dissection.—F eel for the coracoid process in the triangular inter-
val at the head of the humerus between the distal ends of the sab-
scapularis and supraspinatus (Fig 73, '75); the tip of the process
is just at the border of the former muscle near the apex of the inter-
val. Carefully lift the border of the subscapularis with the forceps,
and use the tracer and scalpel to dissect between it and the slender
coracoideus. The latter lies upon the capsule of the joint and
sometimes adheres quite firmly to it.

Separate the connections, when they exist, with the tracer, and
divide the muscle so as to follow the course of the shorter and more
fleshy part (caput breve) from the coracoid process to the surgical
neck of the humerus. The dissection of the longer and more slen-
der caput longum should be done almost wholly with the tracer,
and the delicate tendon should not be pulled in tracing it toward
the distal end of the humerus.

§ 669. Origin—The common origin of the two heads from the
tip of the coracoid process is by a tendon about 1 mm. long.

Insertion.—The short head is inserted by fleshy fibers upon the
caudal surface of the surgical neck of the humerus ; the length of
the area of insertion is approximately equal to half the distance
from its proximal end to the proximal end of the humerus, and the
width equals half the length. The ventral margin of the area of its

252 ANATOMICAL TECHNOLOGY.

insertion is well defined, but the dorsal margin is in contact with
the area of insertion of the proximal division of the internal head of
the triceps, and sometimes fasciculi cross from one muscle to the
other.

The long head is more often absent than present: it is not men-
tioned by Mivart, and its existence in the cat is denied by Meckel
(A, VI, 281). Of the cases observed by us, no two were alike. The
fleshy portion usually leaves the short head at about its middle,
and is 2-3 cm. long. Its tendinous continuation is sometimes fila-
mentary and disappears among the intermuscular fascia; some-
times it is larger and divides, one portion joining the tendon of the
epitrochlearis and the other inserting upon the humerus near the
Fm. epitrochleare ; more often this last is the only attachment, but
the precise point varies so much that the area which was observed
in one case is indicated on Fig. 71 by an interrogation point.

M. SUBSCAPULARIS.

§ 670. Synonymy.—The human subscapularis, G., A, 404, Q., A, I, 203 ; ‘ sozs-scap-
waire,” §.-D., A, I, 345 ; ‘‘ sous-scapulaire,” Ch., A, 266 ; subscapularis, Ch. (F1.), A, 252;
subscapularis, Miv., B, 148.

Figures.—Ental aspect (78, 75); origin area (438) ; insertion area (70, 71).

Posture.—The same as for the coracoideus. The muscle is
already fully exposed.

General Description.—Thick, subtriangular, from most of the
subscapular fossa of the scapula to the trochin of the hwmerus.

Dissection.—In addition to the loose fascia previously removed,
the free surface of the subscapularis is covered by a firmer fascia
which, in places, adheres to the muscle. Complete the removal of
connective tissue and fat from the triangular intervals near the gle-
noid ends of the glenoid and coracoid borders of the muscle, and
between them and the swpraspinatus and teres respectively. Note
that the coracoid interval is twice the length of the other, and
extends about two fifths of the length of the muscle.

Manipulate the muscle so as to indicate the direction of the fas-
ciculi, and note that the central portion of the muscle is hidden near
the glenoid end of the scapula by the converging glenoid and cora-
coid portions.

Transect the muscle to the bone by an -incision connecting the
two borders at the apices of the intervals above mentioned ; bisect
the vertebral end of the muscle and reflect the two sides, noting the

M. SUBSCAPULARIS. 253

extent and manner of connection between the muscle and the bone ;
then reflect the humeral end, noting its close attachment to the cap-.
sule of the shoulder joint.

§ 671. Origin.—By fleshy fibers from the subscapular fossa,
excepting : (A) the oblong area near the vertebral border which
gives insertion to the levator anguli scapule and serratus magnus ;
(B) an irregular quadrilateral area near the glenoid angle of the
bone, the vertebral limit of which coincides nearly with the position
of a vascular foramen about 1 cm. from the lip of the glenoid fossa.
In addition to this general fleshy origin from the periosteum lining
the subscapular fossa, the muscle has at least two lines of tendinous
attachment along the slight ridges which converge toward the gle-
noid angle.

Insertion.—By a strong flat tendon upon the dorsal border of
the trochin of the humerus at the margin of the arthral surface.

§ 672. Explanation of Fig. 74.—The cephalic (outer) aspect
of the left brachium and antebrachium, with the ectal muscles of
the scapular region.

Preparation.—A fter examination of the IM. serratus magnus
and levator anguli scapule, the arm with the scapula was detached
from the trunk by the transection of those muscles.

The spino-deltoideus and acromio-deltoideus have been tran-
sected and reflected.

Bones, etc.—Acromion (Fig. 44, § 392).—As seen in Fig. 67, the tip of this process
coincides with the acromial margin of the M. acromio-delioideus ; but the muscle is here
reflected so as to hide it, and the name has not been connected therewith by a dotted line.

Capitellum radii (§§ 220, 410).—This enlargement of the proximal end of the radius is
shown but not named in Fig. 30. Its position here is nearly indicated by the beginning
of the name.

Epicondylus (Fig. 30, 68, 69, 71, § 415).—The position is nearly indicated by the first
letter of the name.

Olecranon (Fig. 30, § 220).—This proximal process of the ulna forms the angle of the
elbow.

Trochiter (Fig. 30, 46, 68, § 405)—This has been exposed by the removal of the M.
clavo-deltoideus (Fig. 66). By inadvertence it is marked ce.

Muscles.—The following have been sufficiently described in connection with the
figures whose numbers are placed in parentheses :—

Dermo-humeralis (66, 67, 72, 73), $ 629 ; latissimus (66, 67, 72, 78), § 635; rhomboideus
(67), § 620 ; supraspinatus (67), § 675 ; teres, “ teres major,” (67), § 680.

Acromio-deltoideus (§ 676) and spino-deltoideus (§ 674).—These two muscles have been
transected and reflected. The name of the former is written across the scapular end
of both.

254 ANATOMICAL TECHNOLOGY.

Biceps (§ 691).—After transection, the distal part of this was left in place ; the proximal

part is hidden, but appears in Fig. 75.

.

Brachialis (§ 692).—The somewhat thin ectal margin of this flexor of the antebrachium

gives no adequate idea of its size and the extent of its origin area (Fig. 68).

’

evior

M. extensor rac. by

l | ! |

Fie. 74.—Tue CEPHALIC ASPECT OF THE
LEFT ARM, WITH THE EcraL Mus-
CLES OF THE SCAPULA.

Extensor digitorum communis (§ 697)—
The origin areas of this and of the ex. minimi
(§ 698) and ex. ulnaris (§ 699) are closely
grouped on the epicondylus, and their bodies
form a compact mass.

Extensor (carpi) radialis longior (§ 694) and
ex. radialis brevior (§ 696).—The name is
written upon the body of the former, but the
latter is only partially visible, and its name is
written along the side of the swpinator longus.

Flexor ulnaris (§ 702).—The name is writ-
ten along the side of the muscle.

Meditriceps—The “long, middle or scapu-
lar head of the triceps” (§ 682).—The tendon
of this strong muscle is comparatively small
and is partly hidden by the micostalis (here
called teres minor). The body of the muscle
is also partly hidden by the ectotriceps.

Micostalis—“‘ Teres minor” (§ 679).—In
the undissected arm this insignificant muscle
is hidden by the acromio-deltoideus and spino-
deltoideus.

Spino. deltoideus (§ 674).—See acromio-del-
toideus above.

Supinator longus (§ 690).—The MM. of the
name rests upon the proximal end of this mus-
cle, which is seen to emerge between the MM.
biceps and brachialis.

Teres minor—Micostalis.—See above.

M. SUPRASPINATUS.

§ 673. Synonymy.—The human supra.
spinatus, G., A, 405, Q., A, I, 200; “ sys-épi-
neua,” $.-D, A, II, 336; “ sus-@pineux, Ch.,
A, 265; supraspinatus, Ch. (F).), A, 251;
supraspinatus, Miv., B, 148.

Figures.—Kctal aspect (67, 74); part of
ental aspect (73, 75); origin area (44); inser-
tion area (68, 69, 70).

Posture.—Similar to that for the dissection of the subscapularis,
excepting that the arm should rest upon the caudal (inner) side,
and the mesoscapula should be toward the observer.

Dissection.—Note that the ectal surface of the muscle is cov-

M. SPINO-DELTOIDEUS. 255.

ered by a firm fascia, which is closely attached along the border of
the mesoscapula and the coracoid border of the scapula excepting
where it was separated from the subscapularis. Divide these
attachments, cutting from the glenoid angle of the scapula toward
the vertebral border, then transect the muscle at its middle, and
reflect both parts ; the proximal part may be wholly removed.

Origin.—By fleshy fibers from the whole supraspinous fossa,
and, by the ectal fascia, from the coracoid border of the scapula
and mesoscapula.

Insertion.—The muscle passes over the capsule of the shoulder
joint with but slight adhesions thereto, and ends in a short, thick
tendon which is attached to the crest of the trochiter. Between the
trochiter and the tip of the acromion process, the body of the mus-
cle is closely attached to the border of the acromio-deltoideus. The
distal em. of the other—the coracoid—border is connected with the
insertion of the cephalic division of the entopectoralis, as described
under that muscle (§ 658).

M. SPINO-DELTOIDEUS.

§ 674. Synonymy.—The spinal, or mesoscapular, part of the human deltoideus, G., A,
404, Q., A, I, 199; “ delto-spinal,” §.-D., A, II, 338; part of “long abducteur du bras,’ Ch.,
A, 263; part of the long abductor of the arm, or scapular portion of the deltoid, Ch. (F1.),
A, 249; part of deliotd, Miv., B, 147.

Figures.—Ectal aspect (66, 67) ; reflected (74); origin area (44) insertion area (68).

Posture.—Let the arm rest upon its caudal surface on the flat
side of a block, with the elbow toward the dissector. The scapula
may be permitted, at times,-to hang over the end of the block, so
as to render the muscle tense.

Exposure.—Remove the skin upon the cephalic surface of the
brachium to the junction of its middle and distal thirds. Remove
the firm fascia covering the cephalic side of the shoulder.

General Description.—Thin, apparently subtriangular, but
really trapezoidal; from the mesoscapula and metacromion to the
deltoid ridge (Fig. 46, 68, 69), on the proximal half of the cephalic
surface of the humerus.

Dissection.—The dorsal border forms a nearly direct line be-
tween the tuberosity of the mesoscapula and the humerus at the
junction of the proximal and middle thirds. Lift it at its middle,
where it crosses the angle formed between the muscles upon the

256 ANATOMICAL TECHNOLOGY.

glenoid border of the scapula and the dorsal border of the bra-
chium. Here it is easily separated from the subjacent muscles, but
nearer both ends it adheres very closely. Dissect the muscle up
toward the tip of the metacromion. Lift the overlapping border of
the acromio-delloideus, which lies just ventrad of it near the hu-
merus. At the side of the metacromion toward the tip of the acro-
mion will be exposed the short, free, ventral border of the muscle.
Connect the two borders and reflect the ends. In reflecting the
scapular part, avoid cutting into the subjacent infraspinatus, some
fibers of which take their origin from the ental surface of the spino-
deltoideus. The humeral end passes entad of the acromio-deltoi-
deus, most of the fibers of which are inserted upon its ectal surface.

§ 675. Origin.—By short tendinous fibers along the infraspinous
border of the mesoscapula and metacromion, from the tuberosity
of the former to the glenoid angle of the latter, and from a tendinous
raphé between this muscle and the acromio-trapezius.

Insertion.—By a tendon 1-1.5 cm. long upon the deltoid ridge
of the humerus; this extends obliquely distad along the proximal
half of the shaft from the middle of the cephalic surface to the ven-
tral border. The ectal surface of the tendon is wholly covered by
the acromio-trapezius, and the line of insertion is nearly parallel
with that of the insertion of the ectal lamina of the ecfopectoralis.

M. ACROMIO-DELTOIDEUS.

§ 676. Synonymy.—The acromial, or intermediate, part of the human deltoideus, G.,
A, 404, Q., A, I, 199; “ delto-acromial,” 8.-D., A, I, 338; part of the ‘‘ long abducteur du
bras,” Ch., A, 263; part of the long abductor of the arm, or scapular portion of the deltoid,
Ch. (Fl.), A, 249; part of deltoid, Miv., B, 147.

Figures, Posture and Exposure.—As with the IZ. spino-del-
toideus.

General Description.—A short band, from the acromion to the
deltoid ridge of the humerus.

Dissection.—The dorsal—and longer—border was lifted in order
to expose the tendon of the spino-deltoideus. The shorter—or ven-
tral—border may be traced from the tip of the acromion to a point
near the proximal end of the line of insertion of the same muscle,
and forms the dorsal limit of the subcutaneous area of the trochiter
(marked ce in Fig. 74).

§ 677. Origin.—By short tendinous fibers along the infraspinous

M. INFRASPINATUS. 257

border of the acromion, and the contiguous border of the metacro-
mion to near the tip of the latter. .

Insertion.—Most of the fibers seem to terminate upon the ectal
surface of the tendon of the spino-deltoideus, but the ectal layers,
especially at the borders of the muscle, are connected with the bone
by a thin, tendinous sheet, which is attached along a shorter and
straighter line than that of the insertion of the muscle just named
and between it and the insertion of the ectal layer of the ectopecto-
ralis. The proximal end of the line of insertion is 3-4 mm. ventrad
and distad of the proximal end of the line of insertion of the Spine:
deltoideus.

M. INFRASPINATUS.

§ 678. Synonymy.—The human infraspinatus, G., A, 405, Q., A, I, 200; “ sous-épi-
neux,” S.-D., A, II, 344; “‘ sous-épineux,” Ch., A, 265; supraspinatus, Ch. (F1.), A, 251;
infraspinatus, Miv., B, 148.

Figures.—Ectal aspect (67, 74); origin area (44) ; insertion area (68).

Posture.—As for the I/. supraspinatus.

Exposure.—By the reflection of the JM. spino-trapezius, leva-
tor clavicule, spino-deltoideus and acromio-deltoideus.

General Description—From the infraspinous fossa to the
Fossa trochiteriana of the humerus (Fig. 45, B).

Dissection.—_The rounded mesoscapular border may be seen
between the head of the humerus and the metacromion, where it is
overarched by the acromion. The border is, for the most part, in
close contact with the small mzcostalis, but close to the humerus
is an interval filled by connective tissue. Follow this interval
nearly to a point opposite the metacromion, and then divide the
infraspinatus.

In reflecting the humeral part, note a synovial bursa atieeen
the tendon and the dorsal slope of the fossa of insertion. The scap-
ular half separates readily from the micostalis (marked teres minor
upon the figures), but from the teres, nearer the vertebral end of the
scapula, it can be separated only by cutting fibers.

Origin.—By fleshy fibers from the entire supraspinous fossa, and
by short, tendinous fibers from the raphé between it and the feres.

Insertion.—By a strong tendon into the ventral half ofa depression
(fs. trochiteriana, § 404) upon the cephalic aspect of the trochiter.
The proximal end of the insertion is almost in contact with the attach-
ment of the swpraspinatus upon the crest of the trochiter. The

17

258 ANATOMICAL TECHNOLOGY.

insertion of the cephalic division of the ental lamina of the ento-
pectoralis extends just dorsad from this depression, and the Zuber-
culum micostale is just distad of it.

M. MICOSTALIS.

§ 679. Synonymy.—The human teres minor, G., A, 406, Q., A, I, 201; “ micostal,”
S.-D., A, II, 345 ; “ court abducteur du bras, vu petit rond,” Ch., A, 265; short abductor of
the arm, or teres minor, Ch. (FI.), A, 250 ; teres minor, Miv., B, 148.

Figures.—Ectal aspect (74, where the muscle has its more common name teres minor);
origin area (43) ; insertion area (68).

Posture. —As for the I. infraspinatus (§ 678).
Exposure.— By the reflection of the IZ. infraspinatus.

General Description.—Small, from part of the glenoid border
of the scapula to the Tuberculum micostale (Fig. 68).

Dissection.—The mesoscapular border was exposed by the re-
moval of the infraspinatus. The opposite border is nearly in line
with the glenoid border of the scapula, and it is only necessary to
remove some connective tissue between it and the oblique border of
the ectotriceps, and to’ dissect up the muscle from the meditriceps,
to which it adheres somewhat closely. In reflecting, note the close
attachment of the ental surface to the capsule of the shoulder joint.

Origin.—By a sheet of tendinous fibers from the glenoid border
of the scapula, beginning about one fifth of the length of the border
from the glenoid fossa, and ending at its middle.

Insertion.—By a very short tendon upon the Tbcl. micostale on
the cephalic aspect of the trochiter.

M. TERES,

§ 680. Synonymy.—The human teres major, G., A, 406, Q., A, I, 202 ; “ teres,” S-D.,
A, IL, 839 ; “ abducteur du bras, ou grand rond,” Ch., A, 267 ; abductor of the arm, or teres
major, Ch. (FL), A, 253; teres major, Miv., B, 148.

Figures.—Kctal aspect (66, 67, 74); ental aspect (75) ; origin area (43); insertion area
(69, 70).

Posture.—The same as for the IZ. subscapularis.

Exposure.—If the bicipital arch has not been divided, it must
be now ; the brachial artery and nerves accompanying it must be
removed, and the body of the W/. biceps pushed ventrad.

General Description.—<A thick band; from the glenoid border
of the scapula to the ventral surface of the humerus, a little distad

M. EPITROCHLEARIS. 259

of its head ; associated at its origin with the subscapularis, and at
its insertion with the datissimus.

Dissection.— Both borders of the muscle have been indicated
during the examination of the subscapularis and latissimus. Con-
nect them at the point of junction of the JZ. teres with the last named
muscle. The scapular part of the muscle may be dissected from its
attachment along the border of the scapula, but the humeral part—
together with the humeral part of the datissimus—can be reflected
with ease.

Origin.—By fleshy fibers, from all but the glenoid sixth of a
shallow groove along the glenoid border of the scapula; this groove
intervenes between the true glenoid border and the marked ridge
upon the subscapular surface which runs nearly parallel with it at
a distance of 4-5 mm. It arises also from the aponeurotic septum
between it and the swbscapularis.

Insertion.—This has been described in connection with the
M. latissimus (§ 635).

M. EPITROCHLEARIS.

§ 681. Synonymy.—The dorso-epitrochlien of monkeys, and, by exception, of man, Q.,
A, I, 207; “ triceps-interne,” 8.-D., A, Il, 348; dorso-epitrochlear, Miv., A, 137.

Figures.—Ectal aspect (72, left side); distal end, reflected (72, right side); both
ends (75).

Posture.—Let the arm rest upon its cephalic surface, with the
olecranon and the gleno-vertebral angle of the scapula toward the
dissector. The muscle was exposed during the dissection of the
pecto-antebrachialis and clavo-deltoideus.

General Description.—A thin ribbon, from the vertebral bor-
der of the latissimus to the caudal border of the olecranon process
of the ulna.

Dissection.—The ventral border was indicated in the dissection
of the pecto-antebrachialis ; the dorsal border may be seen if the
latissimus is drawn toward the head of the humerus. Both borders
should be freed from connective tissue and thin fascia; then the
muscle may be divided at its middle.

Origin.—Variable and ill defined. By fleshy fibers from the
ventral border of the latissimus, just opposite the oblique line of
union of the latter muscle with the ¢eres, and close to the place of
reception of the dermo-humeralis ; occasionally some of the fibers
arise from the latter muscle.

260 ANATOMICAL TECHNOLOGY.

Insertion.—At the epitrochlea the fleshy fibers are replaced by
a thin tendon which really forms part of the general antebrachial
fascia, and is continuous with the tendons of the pecto-antebrachi-
alis ; so much of the fascia as belongs to this muscle is attached
along the proximal 10-15 mm. of the caudal border of the triangular
subcutaneous area upon the dorsal aspect of the olecranon.

M. MEDITRICEPS.

§ 682. Synonymy.—The human middle or scapular head of the triceps, G., A, 400, Q.,
A, I, 207 ; ‘* biceps-moyen,” 8.-D., A, II, 848; “long eatenseur et gros extenseur de Vavant
bras,” Ch., A, 273; the long and large extensor of the forearm, Ch. (F1.), A, 258; second
part of the triceps, Miv., B, 149.

Figures.—Cephalic aspect (66, 67, 74) ; caudal aspect (72, 75) ; origin area (48).

Posture.—At first the arm should rest upon its cephalic side,
but the posture must be changed several times during the dissection.

Exposure.—By the reflection of the WW. latissimus, teres and
epitrochlearis.

General Description.—Prismatic, from the glenoid third of the
glenoid border of the scapula to the olecranon.

Dissection.— At the middle of its length the ventral border of
the muscle is indicated by the large nerve which lies between it and
the IZ. entotriceps. Let the scapula be flexed upon the brachium
so as to relax the muscle, and dissect from the caudal toward the
cephalic border along its entire length, as far as the epitrochlea.

The cephalic surface is readily separable from the ectotriceps in
its proximal fourth ; but for the rest of its length it is united with
the dorsal border of that muscle by a strong fascia. In reflecting
the distal part, note the close union of both borders of the muscle
in its distal 5 mm., and the presence of a synovial sack over the
bifid tip of the olecranon.

Origin.—By a short tendon, the outline of the section of which
is wedge-shaped, the base toward the glenoid end of the scapula
and the apex toward the gleno-vertebral angle. The line of origin
occupies nearly the glenoid third of the glenoid border, beginning
about 1 mm. from the glenoid fossa.

Insertion.—By a short tendon upon the rounded tuberosity
which forms the dorsal angle of the olecranon; the ventral border
of the tubercle is indicated by a slight transverse furrow.

§ 683. Explanation of Fig. 75.—The muscles on the caudal

MUSCLES OF THE ARM. 261

aspect of the brachium and antebrachium, and the ental aspect of
the scapula.

Preparation.—The cephalic (outer) aspect of the same arm is
shown in Fig. 75. The caudal aspect of the scapular region is also
represented in Fig. 73, but the position of the whole limb is there
reversed. The serratus magnus and levator anguli scapule have
been transected a little nearer the scapula than the rhomboideus,
which appears ectad of them. The dicipital arch has been divided,
and the biceps and epitrochlearis transected and reflected so as to
expose the coracoideus and entotriceps. The muscles on the caudal
and ventral aspect of the antebrachium have been merely freed
from fat and fascia.

Bones, etc.—Antebrachium—the forearm; brachium—the upper arm or proximal
segment of the arm,

Fim, (Foramen) epitrochleare (Fig. 46, § 417).—A part of its ventral orifice is covered by
the humeral end of the M. entotriceps, do. brevis.

Humerus (Fig. 45, 46, 68-71, § 407) Most of the caudal aspect of this bone is exposed ;
the trochin appears at the proximal end.

Olecranon (Fig. 30, § 220).—The prominence of the elbow.

Pre. (Processus) coracoideus—The coracoid process of “the scapula (Fig. 43, 44, 45, A,
§ 400).—In the shaded space between the supraspinatus and subscapularis projects the tip
of this process. Connected therewith are the origin tendon of the coracoideus and the
tendinous slip from the insertion tendon of the entopectvralis, do. cephalica.

Muscles.—The following have been sufficiently described elsewhere, and in the nee
nations of the figures whose numbers are placed in parentheses :—

Latissimus (67), § 635 ; subscapularis (73), § 670 ; supraspinatus (67, 73), § 675; supina-
tor longus (74), § 690.

Biceps (§ 694)—The distal end is seen to pass to the ulna between the proximal ends
of the two groups of muscles lying on the ventral] aspect of the antebrachium: the flezores,
including the pronator teres, and the extensores, including the swpinator longus (see § 695).
The tendon of origin passes entad of and through the Canalis bicipitalis to the Tbel. bicipi-
tale (Fig. 45, A) of the scapula, but in this figure it has the appearance of continuity with
the slip from the entopectoralis to the Pre. coracoideus.

Brachialis (§ 692).—Only a portion is seen between the MM. pronator and ectopectoralis.

Coracoideus (§ 668)—The caput breve has been shown in Fig. 73, and appears here
passing cephalad of (behind) the insertion tendon of the MM. teres and Jatissimus. The
caput longum is seen to pass caudad of the same tendon, to become a very slender, thread-
like tendon, and to become attached to the ventral margin of the Mm. epitrochleare.

Ectopectoralis, lm. entalis, dv. caudalis (§ 653).—The remnant of muscle so named evi-
dently includes also part of the caudal division of the entopectoralis.

Entopectoralis (§ 658).—The name begins near the insertion tendon of the cephalic
division.

Entotriceps, dv. brevis (§ 688).—This is not only the shortest division of the entotriceps,
but forms a very different angle with both the humerus and the olecranon.

Entotriceps, dv. caudalis (§ 687); dv. cephalica (§ 689); dv. intermedia (§ 686).—The
relative positions of these three divisions of the entotriceps are more clearly shown upon

262

ANATOMICAL TECHNOLOGY.

Fig. 71, where their origin areas are seen to be respectively intermediate, distal and prozi-
mal, It should be remembered that the names here applied to them are merely provisional.

Epitrochlearis (§ 681).—The proximal end is in position; the distal tendon has been
reflected ; the tendons of the two divisions of the pecto-antebrachialis ($§ 645-647, Fig. 78),
with which it is associated, have been removed.

n

Fm. gpitrochLleare

antebrackium

Fic. 75.—THE MUSCLES UPON THE ENTAL
ASPECT OF THE SCAPULA AND THE
CAUDAL ASPECT OF THE BRACHIUM
AND ANTEBRACHIUM.

Extensor (carpi) radialis brevior (§ 696) ;
ex. rad. longior (§ 6£4).—The former of
these two associated muscles was but par-
tially visible in Fig. 74.

Hexor (digitorum) communis ectalis.—
This represents the common flexor of the
digits which, in Anthropotomy, is called sub-
limis, superficialis or perforatus. It is not
particularly described herein.

Flexor (carpi) radialis (§ '702).—The divi-
sion of the insertion tendon described by
Straus-Durckheim does not appear in this
figure.

Latissimus (§ 635).—After the division
of the bicipital arch, the parts immediately
concerned in its formation were removed,
The figure shows the intimate association

f the distal ends of the datissimus and teres,
and the origin of the epitrochlearis from the
ectal aspect of the former near its ventral
margin.

Levator anguli scapule (§ 666).—As shown
in Fig. 48 and 73, the origins of this and of
the serratus magnus are practically contin-
uous.

Meditriceps (§ 682).—The cephalic aspect
of the proximal end appears in Fig. 74.

Rhemboideus (§ 620).—The scapular end
of this muscle is seen to be coextensive with
the scapular ends of the serratus magnus
and levator anguli scapule, but, as shown
upon Fig. 43 and 44, the insertion area is
partly upon the ental and partly upon the
ectal aspect of the vertebral margin of the
bone.

Serratus magnus (§ 664).—See lev. ang.
scap., above.

Teres (§ 680).—As stated elsewhere, the
word major is superfluous, The figure well
shows the passage of the combined tendons

of this muscle and the Jatissimus between the two heads of the coracoideus.

M. ENTOTRICEPS. 263

. M. ECTOTRICEPS.

§. 684. Synonymy.—The external head of the human triceps, G., A, 409, Q., A, I, 207;
“ triceps eaterne,” S.-D., A II, 347 ; ‘‘ court eatenseur de [avant bras,” Ch., A, 273 ; short
extensor of the forearm, Ch. (F1.), A, 259 ; first division of the triceps, Miv., B, 149.
Figures.—Ectal aspect (66, 67, 74); origin area (71).

Posture.—The arm may rest upon the shoulder and wrist, the
elbow looking upward, the dorsal aspect of the brachium toward
the dissector, and the antebrachium leaning against a block.

Exposure.—The muscle is subcutaneous in its whole length, and
was exposed in removing the skin from the cephalic aspect of the
brachium.

General Description.—A flattened fusiform mass, from the
proximal part of the deltoid ridge of the humerus to the cephalic
aspect of the olecranon.

Dissection.—The dorsal border was cut from the cephalic border
of the meditriceps, and the whole muscle is attached to the subja-
cent muscles only by connective tissue; an artery enters its ental
surface a little proximad of the middle of the length, and must be
divided. The ventral border is attached to the brachialis upon the
cephalic side of the arm by a strong fascia, but at the middle of the
muscle it is thinner than elsewhere, and may be cut first. Then
transect the muscle and reflect it, dividing the fascia between its
ventral border and the adjacent parts.

Origin.—By a thin tendon from the proximal part of the deltoid
ridge and from the dorso-cephalic aspect of the neck of the humerus.
The line of attachment is curved so as to pass ventrad of the tuber-
cle for the insertion of the micostalis, and dorsad of the origin of
the middle division of the entotriceps, some fibers of which seem to
spring from the tendon of the ectotriceps. The line begins about
5 mm. proximad of the proximal end of the line of insertion of the
spino-deltoideus.

Insertion.—The proper tendon is 5 mm. wide at its attachment
to the cephalic border of the olecranon, but the distal half of the
ventral border of the muscle is so firmly connected to the brachial
and antebrachial fascia that it may be said to have a general inser-
tion upon the region about the elbow.

M. ENTOTRICEPS.

§ 685. Remark.—The remaining extensors of the antebrachium are not easy to
homologize with the parts of the human triceps, anconeus and subanconeus ; the names

264 ANATOMICAL TECHNOLOGY.

here given to them are provisional and descriptive rather than designatory. They readily
separate, and no special directions for dissection are required.

DY. INTERMEDIA.

§ 686. Synonymy.—Straus-Durckheim (A, II, 850) calls this “le premier chef de
Panconé moyen” ; Mivart describes it as the fourth division of the triceps (B, 149).
Figures. —In part (75) ; origin area (68, 71).

Origin.—By fleshy fibers from the dorsal surface of the surgical
neck of the humerus, and from the proximal part of the shaft.
Sometimes the attachment extends upon the arthral capsule. The
length of the area of origin equals about one sixth of the length of
the humerus. Its caudal border is encroached upon by the area
of insertion of the JZ. coracoideus, caput breve, but the cephalic
border is rounded, and embraeed by the line of origin of the JZ.
ectotriceps. The triangular apex of the area lies between the ori-
gins of the caudal division next to be described and the IZ. brachi-
alis. The ventral border is indicated by the radial artery and
nerve which lie between it and the do. caudalis.

Insertion. —At the junction of the middle and distal thirds of
the humerus the muscle ends in a slender, flat tendon which widens
slightly as it nears the elbow, rests in the furrow at the proximal
end of the bone, and is inserted into the oblique ridge which forms
the dorsal limit of the furrow, thus slightly ventrad of the ridge of
insertion of the meditriceps. Between the tendon and the floor of
the furrow is a synovial capsule.

DV. CAUDALIS.
§ 687. Synonymy.—Called by S.-D. (A, II, 350) ‘le second chef de V'anconé moyen” ;
it is the third division of Mivart (B, 149).
Figures.—Caudal aspect (75) ; origin area (70, 71).

Origin——By fleshy fibers from a subtriangular area, a little
proximad of the middle of the dorso-caudal aspect of the humerus.
The length of the area equals about one sixth of the length of the
bone. Its apex points proximad, and is almost continuous with
the apex of the origin area of the Do. intermedia.

Along the caudal border of the distal part of the muscle runs
the wlnar nerve, and the radial artery and nerve cross the dorsal
border at about the junction of the proximal and middle thirds.

Insertion.—By short, tendinous fibers upon the caudal border
of the ventral aspect of the olecranon as far as the lip of the greater
sigmoid notch (Fig. 30).

M, SUPINATOR LONGUS. 265

DV. BREVIS.

§ 688. Synonymy.—The anconé interne of S.-D., A, II, 351; the fifth division of the
triceps, Mivart, B, 149.
Figures.—Ental aspect (75); origin area (70, 71).

Origin.— By fleshy or short tendinous fibers from the ectal sur-
face of the osseous bar which encloses the Yoramen epitrochleare,
as far as the origin area of the pronator teres upon the epitrochlea.

Insertion.—By fleshy fibers into the caudal border of the olecra-
non, just distad of the furrow for the insertion of the meditriceps.

DV. CEPHALICA,

§ 689. Synonymy.— The anconé externe, S.-D., A, II, 350 ; the anconeus, Miv., B, 149.
Figures.—Indistinctly (75) ; origin area (71).

Exposure.—The strong fascia upon the cephalic surface of the
elbow must be removed.

Origin.—By fleshy fibers from the elongated triangular surface
upon the distal half of the dorsal surface of the humeral shaft.
The cephalic limit of the area is indicated by the prominent ridge
which extends obliquely distad from the middle of the dorsal sur-
face to the epicondyle. The caudal border extends more nearly in
the line of the axis of the bone.

Insertion.—By fleshy fibers upon the cephalic side of the olecra-
non, from the insertion of the middle division to a point opposite
the distal lip of the greater sigmoid notch, which is just distad of
the epicondyle. The insertion area is about 2 cm. long.

The ental surface of the muscle is attached to the capsule of the
elbow joint, but its thickness indicates that it serves some other
purpose than that suggested by Straus-Durckheim, namely, to keep
the capsule tense.

M. SUPINATOR LONGUS.

§ 690. Synonymy.—The human swpinator longus, G., A, 415, Q., A, I, 215; “long
supinateur,” 8.-D., A, II, 356 ; ‘‘ long supinateur,” Ch., A, 289; long supinator, Ch. (F1.),
A, 272 ; supinator longus, Miv., A, 151.

Figures.—Cephalic aspect (74) ; caudal aspect (75); origin line (71).

Posture.—The arm may rest upon the caudal surface most of
the time, but must be held in various positions at different stages
of the dissection.

Exposure.—Divide the skin and the ectal fascia from the epi-
condyle to the wrist, and girdle the arm between the Hminentia

266 ANATOMICAL TECHNOLOGY.

hypothenaris (Fig. 105) and the base of the pollex. The girdling
must be done with care, so as not to divide any of the tendons at
the wrist. Reflect the skin and fascia first upon the caudal (ulnar)
side of the antebrachium.

General Description.—A slender muscle from the p RE side
of the humerus to the distal end of the radius.

Dissection.—If the antebrachium is extended slightly, the free
ventral border of the muscle will appear. The dorsal border is
attached by connective tissue to the subjacent muscles, excepting
close to the ventral border of the brachium, where a large nerve
passes between it and the next muscle. ‘Trace this border distad to
near the end of the radius, noting that the connections with the sub-
jacent muscles become firmer toward the wrist. Divide the muscle,
and reflect the proximal end ; this sometimes adheres so closely to
the cephalic surface of the brachialis that, for 5-7 mm. from the
humerus, it cannot be separated without cutting fibers.

Origin.—By a very thin tendon, from the middle fifth of the dor-
sal border of the humerus; a third of the origin line lies between
the origin areas of the brachialis and the cephalic division of the
entotriceps ; the rest of the line is a direct proximal continuation
of the apex of the origin area of the last named muscle, and ceases
at the distal end of the origin area of the caudal division.

Insertion.—By fleshy fibers upon the distal end of the radius,
just proximad of the grooves for the tendons of the ZW. extensores
radiales and upon the adjacent ligaments.

M. BICEPS.

§ 691 Synonymy.—The human biceps brachialis, G., A, 408, or biceps flexor cubiti, Q.,
A, I, 205; “ biceps,” S.-D., A, II, 358 ; ‘‘ long fléchisseur de Cavant bras ou biceps brachial,”
Ch., A, 271 ; long flexor of the forearm or brachial biceps, Ch. (F1.), A, 255 ; biceps, Miv., B, 148.

Figures.—Ventro-caudal aspect (72, 73): cephalic aspect of distal end (74) ; reflected
(75); origin point, tuberculum bicipitale (45, A, 48); insertion point, tuberositas bicipi-
talis (30).

Posture.—At first the arm should rest upon the cephalic side.
The muscle was exposed by the division of the dicipital arch (§ 662).

General Description.—.A long, fusiform muscle extending the
whole length of the ventral surface of the brachium, from the
bicipital tubercle of the scapula to the bicipital tuberosity of the
radius.

Dissection.—No preliminary dissection is needed beyond freeing
the muscle from fascia and connective tissue. After transection, if

M. BRACHTIALIS. 267

the scapula is strongly flexed upon the brachium, the tendon of ori-
gin of the muscle may be seen to play in the bicipital groove. If
now the capsule is opened, the tendon will be seen to be still cov-
ered by a special sheath, so that it does not lie free within the cap-
sule. If it be desirable to expose the whole tendon, the dissector
must divide the coracoid attachment of the entopectoralis and the
expanded tendon of the zviphi-humeralis.

The distal end of the J/. biceps must then be freed from general
connective tissue, and special note taken of a rather jirm tendinous ©
band which connects the caudal side of the muscle with the fascia
covering the JZ. pronator teres. The insertion cannot be seen until
some of the antebrachial muscles are removed, but, by lifting the
border of the muscle which arises from the epicondyle, it is possible
to trace the tendon of the biceps toward a point upon the radius
distad of the attachment of the clavo-deltoideus and brachialis.

Origin.—By a strong, rounded tendon, 1.5 cm. long, from the
prominent glenoid lip of the glenoid fossa of the scapula. (In man,
a second tendon—that of the ‘‘ short” or ‘‘ coracoid’’ head—arises
from the tip of the Pre. coracoideus.)

Insertion.—By a similar, though slightly shorter, tendon upon
the bicipital tuberosity of the radius. An additional slight inser-
tion is by the tendinous band above mentioned upon the ventral
surface of the pronator teres.

M. BRACHIALIS.

§ 692. Synonymy.—The human brachialis anticus, G., A, 409, Q., A, 1, 206; ‘‘bra-
chial,” $.-D., A, Il, 354; “court fléchisseur de Vavant bras ou brachial anterieur,’ Ch., A,
272 ; short flexor of the forearm, Ch. (FI1.), A, 256 ; brachialis anticus, Miv., B, 148.

Figures.—Kctal aspect (74); ental aspect (75); origin area (68, 71); insertion area,
indistinctly (80).

Posture.— With this and the remaining muscles the appropriate
posture will readily suggest itself to the dissector.

Exposure.—By the reflection of the WM. biceps and supinator
longus. .

General Description.—From an irregular, long, v-shaped line
upon the cephalic surface of the shaft of the humerus to the ulna
near its proximal end.

Dissection.— Flex the brachium slightly upon the antebrachium
so as to relax the muscle. At the border of the antebrachium push
it slightly cephalad, and note that here it is attached to the hume-

268 ANATOMICAL TECHNOLOGY.

rus only by loose connective tissue, which may be torn with the
tracer.

Note here the median nerve and brachial artery after their
passage through the Foramen epitrochleare. Still keeping the
brachium flexed, separate the cephalic side of the muscle from the
series of antebrachial muscles arising from the cephalic side of the
humerus. The muscle may be divided just proximad of its union
with the clavo-deltoideus.

§ 693. Origin.—By fleshy fibers from an irregular, long, v-shaped
line extending almost the whole length of the cephalic surface of the
shaft of the humerus. The apex of the a is represented by a trian-
gular area a little distad of the tubercle for insertion of the J.
micostalis.

The dorsal and longer branch of the » extends dorso-distad to
near the middle of the length of the bone, thence distad to the crista
epicondylaris, which it follows to opposite the proximal end of the
Fin. epitrochleare.

The ventral branch runs ventro-distad parallel with the crista
deltoidea, then distad to about the junction of the middle and distal
thirds of the bone.

Each of these branches is 2-4 mm. wide, and is really therefore
a long and narrow area rather than a line. The triangular space
between them does not give origin to fibers.

Insertion.—From this peculiar origin the fibers converge to form a flat tendon .5-1 cm.
wide, which is closely attached by its ectal surface to the ental surface of the tendon of
the M. clavo-deltoideus. The tendon of the brachialis is inserted upon the dorsal portion of
the depressed rough area on the caudal] aspect of the ulna just distad of the greater sig-
moid notch and about midway between the dorsal and ventral margins of the bone.

This account of the M. brachialis is derived mainly from the illustrated Thesis of
Homer Collins, B. 8., a special student in the Anatomical Laboratory of Cornell Univer-
sity. The dotted lines upon Fig. 68, 71 approximately include the outline of the v-shaped
line, but they should be double.

M. EXTENSOR (CARPI) RADIALIS LONGIOR.

§ 694. Synonymy.—The human muscle of the same name, G., A, 415, Q., A, I, 216;
“ premier radial,” 8.-D., A, I, 359 ; part of the “ extenseur antérieur du métacarpe,” Ch.,
A, 277 ; part of the anterior extensor of the metacarpus, Ch. (F1.), A, 262 ; extensor carpi
radialis longior, Miv., B, 151.

Figures.—Cephalic aspect (74) ; caudal aspect (75); origin area (71).

General Description.—From the epicondylar ridge of the humerus to the proximal
end of the indical metacarpal. ;

M. EXTENSOR (CARPI) RADIALIS BREVIOR, 269

Dissection.—Just dorsad of the insertion of the swpinator longus is the oblique border
of the strong tendon of the M. eatensor ossis metacarpt pollicis. Entad of this tendon may
be seen another tendon evidently continuous with the muscle lying along the cephalic bor-
der of the antebrachium. With the tracer, separate the tendon: into two, an ectal and
more slender, and an ental and thicker. The former may be traced proximad for two
fifths of the length of the antebrachium, where it is continuous with its muscle, the extensor
carpi (radialis) longior.

Divide the muscle at the middle ; in reflecting the proximal end, note that it becomes
thinner and wider, is wedged somewhat between two subjacent muscles, and, at the
humerus, has a third or a fourth overlapped by the muscle arising just distad of it.

By pulling upon the tendon, and alternately flexing and extending the manus, it may
be seen that the tendon passes across the carpus entad of the oblique tendon of the eaten-
sor metacarpt pollicis. With the arthrotome, cut the fascia at one side of the tendon upon
the carpus, introduce the tracer, and thus indicate where more incisions may be made so
as to expose the whole tendon as far as the proximal end of the indical metacarpal.

Note that, in its passage over the distal end of the radius, the tendon lies in a groove
upon the dorso-cephalic side of the bone, separated by a triangular elevation from the
groove for the tendon of the eatensor metacarpi pollicis.

§ 695. Remark.—By analogy with the less modified leg, the muscles of the arm which
lie upon the dorsal aspect of the antebrachium and are inserted upon the ‘carpus should be
called flexors, and those upon the caudal aspect eatensors. These and other considerations
have been presented by the senior author (1 and 4). In an ideal myological nomen-
clature, we believe the muscles should be named as above, but in the present practical
work it seems best to retain the designations commonly accepted.

Origin.—By fleshy fibers from the epicondylar ridge of the humerus, between the
origin area of the swpinator longus and a point opposite the distal end of the Foramen epi-
trochleare. The larger part of the origin line lies between the slender distal prolongation
of the origin area of the brachialis and the triangular origin area of the cephalic division of
the entotriceps. The distal fourth or fifth is just ventrad of the origin line of the extensor
communis (digitorum).

Insertion.—By a long tendon upon the dorsal border of the proximal end of the indi-
cal metacarpal.

Remark.—Like other tendons which pass over the wrist, this is held in place by liga-
mentous bands representing parts of the annular or armillary ligaments.

M. EXTENSOR (CARPI) RADIALIS BREVIOR.

§ 696. Synonymy.—The human muscle of the same name, G., A, 416, Q., A, I, 216;
‘* second radial,” §.-D., A, II, 359 ; part of the “ eatenseur antérieur du métacarpe,” Ch., A,
277; part of the anterior extensor of the metacarpus, Ch. (FI.), A, 262 ; eat. carpi rad. bre-
vior, Miv., B, 151.

Figures.—Cephalic aspect, in part (74) ; caudal aspect (75) ; origin area (68).

General Description.—From the epicondylar ridge of the humerus, just proximad of
the epicondylus, to the base of the medial metacarpal.

Dissection.—The thicker tendon mentioned as joined with that of the ex. rad. longior
belongs to the present muscle. This tendon is shorter than the other, and the body pro-
portionately longer, as well as thicker. Divide it 1 cm. farther distad than in the case of
the ex. rad. longior, and reflect both ends. ©

Origin.—By fleshy or short, tendinous fibers from the epicondylar crest, just distad of

270. ANATOMICAL TECHNOLOGY.

the origin of the ex. vad. longior. The origin area cannot be seen fully until after the
removal of the ex. communis.

Insertion.—The tendon passes through the same groove as the tendon of the ea. rad.
longior, and is inserted upon the dorsal side of the proximal end of the medial metacarpal.

M. EXTENSOR (DIGITORUM) COMMUNIS.

§ 697. Synonymy.—The muscle has the same name in human anatomy, G., A, 417,
Q., A, I, 216; extenszur commune des doigts, 8.-D., A, I, 364; extenseur antérieur des pha-
langes, Ch., A, 275 ; anterior extensor of the phalanges, Ch. (F).), A, 263 ; eat. dig. commu-
nis, Miv., B, 151.

Figures.—Ectal aspect (74); origin area (68, 71).

Dissection.—The muscles remaining upon the cephalic and dorsal surfaces of the ante-
brachium are covered by a dense fascia which must be removed. Near the wrist note a
wide tendon which passes ectad of the M. abductor ossis metacarpi pollicis. Trace it to the
corresponding muscle, and this to the humerus, and transect the muscle at its middle.

Origin.—By fleshy and tendinous fibers from the epicondylar ridge. The origin area
is about 9 mm. long, and extends from the disto-cephalic angle of the origin area of the
cephalic division of the entotriceps to the trochlea ; it lies just dorsad of the origin area of
the eatensor rad. brevior and of the distal fifth of the ex. rad. longior.

Insertion.—The tendon lies in a groove upon the dorsal surface of the distal end of the
radius, from which it may be disengaged by slitting up the ligament which converts the
groove into a canal. It then divides into four tendons which may be traced to the dorsal

aspect of the four ordinary digits.

M. EXTENSOR MINIMI (DIGITD.

§ 698. Synonymy.—The human muscle so called (G., A, 417, Q., A, I, 218), sends a
tendon to only the minimus, while in the cat and dog what seems to be the same muscle
supplies also the annularis and medius ; (see Huxley, A, 418). S.-D., however (A, II, 368,
369), regards it as forming three separate muscles, one for each digit, excepting the pollex
and index, which he terms 2. prop. du verpus, paramese and micros, respectively. Hxten-
seur laterale des phalanges, Ch., A, 279 ; lateral extensor r of the phalanges, Ch. (F1.), A, 264;
extensor minimi digiti, Miv., B, 151.

Figures.—Dorsal aspect (74) ; origin area (68, 71).

Origin.—From the ventral border of the epicondyle just distad of the origin of the
extensor communis, The proximal part of the origin is by muscular fibers, and the distal
by ashort tendon At 2-3 mm. from the origin the muscle divides into a slender ectal
portion and a thicker ental part, which are in close contact, but may be separated without
cutting fibers. The former becomes tendinous at the junction of the proximal and middle
thirds of the antebrachium, and the latter at the junction of the distal and middle thirds.

Insertion.—The tendons join the corresponding tendons of the extensor communis.

M. EXTENSOR (CARPI) ULNARIS.

§ 699. Synonymy.—The human muscle of the same name, G., A, 417, Q., A, I, 218;
cubital, 8.-D., A, II, 360 ; ew. carpi ulnaris, Miv.. B, 152.

Figures.—Dorsal aspect (74); origin area (68).

Origin.—In two parts: (A) by a short, broad tendon from the distal end of the epicon-
dyle next to the origin of the extensor minimi ; (B) by a smaller and rounded tendon
from the proximal lip of the sigmoid notch of the ulna.

M. INDICATOR. 271

Insertion.—The muscular fibers continue to within 1 cm. of the wrist ; the tendon,
about 4 mm. wide, passes over the distal end of the ulna, is connected with ligaments, and
is inserted upon the tubercle at the caudal side of the proximal end of the minimal meta-

carpal.
M. INDICATOR.

§ 700. Synonymy.—The eatensor indicis or indicator, Q., A, I, 220 ; eatensor indicis,
G., A, 418 ; “indicator,” Dunglison, A, 676 ; ‘‘ indicateur,’ S.-D., A, I, 867; eat. indicis
and ea. secundi internodti pollicis, Miv., B, 152.

Origin.—By fleshy fibers along the cephalic border of the ulna, from the lesser sigmoid
notch to the junction of the distal and middle thirds of the bone, exclusive of the olecranon.
The proximal third of the muscular portion resembles the ordinary antebrachial muscles,
and is continuous with a slender tendon; the remaining fibers form a thin, loosely con-
nected series of bundles extending distad at an angle of about 45 degrees with the bone to
be attached to the tendon almost to the wrist.

Insertion.—At the wrist the tendon divides into two, both of which are connected with
the indical tendon of the extensor communis. The more caudal of the two tendons some-
times receives a small tendinous slip from the medial tendon of the extensor minimi. In
some cases the tendon divides into three, which are distributed respectively to the medius,
the index and the second segment of the pollex.

M. PRONATOR TERES.

§ 701. Synonymy.—The human pronator radii teres, G., A, 411, Q., A, I, 209; “rond
pronateur,” S.-D., A, I, 357 ; pronator teres, Miv., B, 149.

Figures.—Caudal aspect (75) ; origin area (70, 71).

Origin.—By a short, strong tendon from the extremity of the epitrochlea just distad
of the origin of the short division of the entotriceps,

Insertion.—By fleshy and short tendinous fibers for about 1.5 cm. along the cophalig
border of the radius at its middle.

M. FLEXOR (CARPI) RADIALIS.

§ 702. Synonymy.—The human flexor carpi radialis, G., A, 411, Q., A, I, 210; “cer-
cialis,” $.-D., A, Il, 362; flexor carpi radialis, Miv., B, 149.

Figures.—Caudal aspect (75) ; origin area (70).

Origin.—By fleshy and short tendinous fibers from the distal aspect of the epitrochiea.

Insertion.—The muscle becomes tendinous about 2 cm. from the wrist, passes deeply
entad of the surface, and, according to Straus-Durckheim, divides into two tendons which
are attached to the indical and medial metacarpals.

§ 703. Other Muscles.—In addition to the muscles described in the foregoing pages,
the figures indicate more or less fully the position and connections of the following : MM.
supra-cervico-cutaneus and cervico-auricularis (66) ; temporalis, masseter, digastricus and
splenius (67); sterno-hyoideus, sterno-thyroideus, rectus and ectobliquus (abdominis) (72);
intercostales, rectus, ectobliquus, splenius and sterno-hyoideus (78) ; flexor ulnaris and flexor
digitorum communis ectalis (75).

The muscles just named, together with all others of the cat, are more or less fully
described by Straus-Durckheim, and most of them are at least enumerated by Mivart.

272. ANATOMICAL TECHNOLOGY.

§ 704. The Obvious Structure of Muscle.—A muscle is readily
seen to be a collection of more or less elongated, reddish, fleshy
bundles attached at each end more or less independently or by a
common fibrous structure, the ¢endon. The bundles are easily sep-
arable into smaller bundles called fasciculi. <A perimysium or
sheath of connective tissue surrounds each muscle, and from this
partitions extend between the fasciculi, furnishing each with a sep-
arate sheath.

§ 705. Microscopic Structure.—/i%ders.—Each fasciculus is
composed of a variable number of cylindrical fibers.

Striation—The fibers appear to be composed of alternate light
and dark segments. A muscle which has been hardened, in alcohol
for example, also presents an appearance of longitudinal striation,
and if it be teased carefully, it may be divided into finer threads
called fibrille ; each fibrilla shows the same alternating light and
dark bands as the entire fiber.

Sarcolemma.—Surrounding each fiber is a delicate sheath of
elastic tissue.

Nuclei or Muscle Corpuscles—These are clear oval bodies found
in the fibers. In Mammalian muscles they lie on the surface of the
sarcolemma, but in Amphibia they are distributed throughout the
substance of the fibers.

Length.—The average length of a fiber is nearly 3 cm. They
are of nearly uniform size throughout, but sometimes branched as
in the tongue.

Connection with Tendons.—A. When continued in a direct line
with a tendon, the fiber merges into the tendon somewhat abruptly,
yet it can be distinguished from tendon only by the absence of
cross striation in the latter.

B. When the fibers join the tendon at a more or less acute angle,
they terminate in rounded ends which are received into correspond-
ing depressions in the tendinous structures. Quain, A, II, 115.

CHAPTER VII.

THE ABDOMINAL VISCERA, SALIVARY GLANDS, MOUTH, NECK AND
THORAX.

LIST OF INSTRUMENTS AND MATERIAL—STOMACH—LIVER—PANCREAS—SMALL INTES-
TINE—LARGE INTESTINE—URINARY ORGANS—SALIVARY GLANDS—MOUTH—NECK—
THORAX—TRACHEA—CGSOPHAGUS—THYMUS—DIAPHRAGM.

ABDOMINAL VISCERA.

There is first given a general consideration of the parts, to enable
the student to recognize them. This is followed by a more detailed
description.

§ 706. It is advisable to employ at least two specimens for the
abdomen, one for the viscera and the other for the blood vessels.
If specimens cannot be obtained readily, the thoracic and abdomi-
nal viscera and vessels may be studied upon a single individual.

Preparation.—Just before the explanation of each figure there is given the method of
preparing the part or organ for that particular figure. The directions for demonstration
to be followed by the student are given in the text proper.

§ 707. Names of Parts in Order of Examination.—(1) Perito-
neum ; (2) Diaphragma, diaphragm ; (3) Hepar, liver, and cholecys-
tis or gall bladder; (4) Stomachus, stomach; (5) Splen, spleen ;
(6) Omentum majus, great-omentum ; (7) Intestinum tenue, small
intestine; (8) Urocystis, urinary bladder; (9) Intestinum amplum,
large intestine ; (10) Pancreas; (11) Mesenterium, mesentery ; (12)
Ren, kidney ; (13) Uterus (or vas deferens) ; (14) Ovarium, ovary.

Instruments and Material.—Coarse comb ; 15 per cent. glycerin ; injecting appa-
ratus and material (§ 336); scalpel; scissors; sponge; thread; towel: tray; tracer;
water.

$ 708. Choice of Specimen.—Choose a young adult, lean cat.
It may be fasting, but preferably the stomach should contain a
moderate amount of solid food..
18

274 ANATOMICAL TECHNOLOGY.

§ 709. Posture and Preparation.—Place the cat dorsicumbent ;
fasten the arms and legs laterad with cords tied to the loops on the
edges of the tray (Fig. 76). Take the precautions for cleanliness
(§ 199). When the examination is made in warm weather or is to
extend over several days, the arteries should be injected with alco-
hol as directed in § 284. If the vascular system itself is to be

Se

yiphfiteram |

Tray, f= Sematr

Ss
N

——
Fie. 76.—LINEs OF INCISION FOR EXPOSING THE THORACIC AND ABDOMINAL
VISCERA; x.25.

studied in the same individual, both arteries and veins should be
injected with plaster (§§ 352, 362).

If the thorax is not to be studied, open it (§ 825), cut the precava to allow the blood to ;
escape, and inject caudad through the postcava and the aorta thoracica. If the vessels are
to be studied on a separate specimen, the injection may be omitted.
Keep all exposed parts moist with the 15 per cent. glycerin (§ 171). - |
|

ABDOMINAL VISCERA. 275

§ 710. Exposure.—Determine the three following landmarks by
pressing on the various parts of the abdomen where they are indi-
cated (Fig. 76): (A) The ventrimeson by finding the xiphisternum
(Fig. 30, 72, § 228); (B) the caudal margin of the 12th rib (Fig. 30,
72); (C) the pubis (Fig. 51, 76, § 228).

After having determined the three landmarks, the hair should
be moistened and parted as directed above (§§ 354, 599); then the
incisions should be made along the lines indicated in Fig. 76.
Make the incisions in the manner described for abdominal transec-
tion (§ 237). Reflect the four flaps, being careful not to tear any of
the thin membranes—urocystic and hepatic ligaments, etc.—attached
along the meson.

Preparation and Exposure —Fig. 77.—The cat was fed a mod-
erate amount of meat about an hour before it was killed with
chloroform. After death it was placed dorsicumbent on the dem-
onstration board, the head fastened with the pointed holder (see
Fig. 77), and the limbs secured laterad with the straps.

After parting the hair (§ 354), an incision was made from the
angle of the mouth on the right, along the middle of the side of
the neck, thorax and abdomen, then on the left side as far cepha-
lad as the angle of the mandible. The mucous membrane and
the thick muscles on the side of the face and neck were cut at
the same level as the skin, and the right mandibular ramus dis-
jointed with the arthrotome. The hyoid bone (Fig. 30, § 224) was
cut, and the left coronoid process (Fig. 61) broken with nippers ;
this made it possible to turn the mandible to the left so as to expose
the pharynz and the floor and roof of the mouth.

The ribs and soft parts of the abdominal and thoracic wall were
then cut with scalpel and nippers at the same level as the incision
in the skin. The mediastinal septum and the diaphragm were cut
with scissors close to the ventral wall, and the entire ventral wall
of the body was removed.

In some specimens the ovary (ovarium) and kidney (ren) will
not appear without displacement of the intestines, and in old ani-
mals the thymus may be absent (Fig. 77, Cp. thym.). The following
parts will be exposed (Fig. 77) :—

Description of Fig. 77.—Cardia, az.—Heart. Cholecystis, az.
—Gall bladder. Cornu Uteri.—Left horn of the uterus. Costze.—
Ribs (13). The cut ends are shown on each side of the thorax.
Cp. thym., Corpus thymicum, «z.—Thymus body or gland. Dia-

276 ANATOMICAL TECHNOLOGY.

Holder

Vi briss@E
+

\

SE-Ost det Stenon
was

f). Ost. det Wharton.
4 . A = . = “ y .

Cholecystis 5
Intestinum

=

Fie. 77.—GENERAL VIEW OF THE VISCERA; x.25.

phragma, az.—Diaphragm, ‘midriff.’ Epglt., Epiglottis, az.
Hepar, az.—Liver. Pointed Holder. Intestinum amplum, az.—
Large intestine. Intestinum Tenue, az.—Small intestine. Leg.
lat., Ligamentum laterale.—Lateral ligament of the urocystis.

ABDOMINAL . VISCERA, 277

Lingua, az.—Tongue. Mndb., Mandibula.—Mandible, lower jaw.
Gs., Gsophagus, ez.—Gullet. Omentum majus, az.—Epiploon,
great omentum, caul. O. hy., Os hyoides.—Hyoid bone. Ost.
det. Stenon., Ostium ductus Stenoniani.—Mouth or opening of
the duct of Stenon, duct of the parotid gland. Ost. dct. Wharton.,
Ostium ductus Whartoniani—Mouth or opening of Wharton’s
duct, duct of the submaxillary gland. Ovarium.—Ovary. Pili
tactiles.—Tactile hairs (see Fig. 105), Pulmo.—Lung. Ren.—
Left kidney. Splen, az.—The spleen. Stomachus, az.—The stom-
ach. Tnsl., Tonsilla.—Left tonsil. (The tonsils are composed
mostly of lymphoid tissue and are abundantly supplied with blood
vessels and nerves. The function of the tonsils is not well under-
stood ; Quain, A, II, 335). Trachea, az—Wind-pipe. Urocystis,
az.—Urinary bladder. Vibrisse.—Whiskers. V1. plt., Velum
palati, 7z.—This is the veil-like or pendulous part of the soft- pal-
ate ; its caudal margin is free (Fig. 88).

§ 711. Peritoneum (§ 725).—This is the smooth shining mem-
brane lining the abdominal cavity and covering the viscera. It
may be separated from the muscular parietes over a small area by
using the tracer.

§ 712. Diaphragma, az. (Fig. 77, § 734)-—Grasp the free edge
of the cephalic abdominal flaps (Fig. 76); draw them upward, and
look toward the cephalic end of the abdominal cavity. The dia-
phragm will appear as a transverse muscular curtain separating the
abdomen from the thorax.

§ 713. Hepar and Cholecystis, az.—Liver and gall bladder
(Fig. 77, §§ 744, 745).—The liver'is a deep red, multilobular organ
occupying nearly the entire cephalic part of the thorax, but espe-
cially the dextral part.

The cholecystis is a reservoir for bile ; it usually appears as a
greenish sac in one of the lobes. If it does not appear, grasp the
caudal margin of the liver and turn it slightly toward the thorax.
The cholecyst will appear as a pear-shaped, greenish sac partly
imbedded in the substance of the middle lobe.

§ 714. Stomachus, az. (Fig. 77, 79, § '735).—This is a somewhat
pear-shaped organ extending obliquely across the cephalic part of the
abdominal cavity. Its larger, cardiac or esophageal end (Fig. 79)
is next the diaphragm and mainly in the left half of the cavity.
The small or pyloric end is sharply curved. It is partly covered by

278 ANATOMICAL TECHNOLOGY.

the liver, and may be fully exposed by turning the edge of that
organ cephalad.

The space occupied by the stomach depends largely on the
amount of food it contains.

§ 715. Splen, az.—Spleen (Fig. 103, § 737).—This is a deep red,
usually single lobed organ, situated on the sinistro-caudal aspect
of the stomach.

§ 716. Omentum majus, epiploon, az.—Great omentum (Fig. 77,
§ 727)—This appears as a kind of transparent apron extending
caudad from the stomach. It contains many strips of fat.

§ 717. Intestinum tenue, az.—Small intestine.—Very carefully
turn the omentum over toward the thorax. The greatly coiled cyl-
indrical small intestine will be exposed (Fig. 77, § 738).

§ 718. Urocystis,az—Urinary bladder (Fig. 77,101, § 757).—In
the caudal part of the abdomen will be seen a median sac, usually
more or less filled with liquid. This is the urocystis, the receptacle
of the urine.

§ 719. Intestinum amplum, a@z.—Large intestine (Fig. 77, § 742).
—Turn the coil of small intestine toward the left leg. The large
intestine will be seen on the right side extending first cephalad from
a blind extremity, the caecum (Fig. 80), nearly to the stomach, then
transversely across the cavity a little to the left of the meson, and
finally somewhat obliquely caudad.

§ 720. Pancreas, az. (Fig. 81, 103, § 746).—Turn the large intestine
to the left ; the pancreas will appear as a pinkish, finely lobulated
and elongated body within the great omentum near its dorsal
attachment to the stomach. It extends from the spleen dextrad to
the pylorus, and then for 5-10 em. along the small intestine (Fig. 83).

§ 721. Mesenterium, az.—Mesentery (Fig. 78, § 726).—Grasp
the small intestine and lift it up. The mesentery is the translucent
membrane supporting the intestine and serving to attach it to the
body. It is a fold of peritoneum (§ 726).

§ 722. Ren—Kidney (Fig. 101, § 761).—Turn the stomach and
intestines to the right, and the left kidney, a dark red body, will
appear resting on the ventral surface of the muscles of the back
near the meson and but a short distance from the diaphragm.

§ 723. Uterus, az. (Fig. 77, § 759).—Turn the urocystis ventro-
caudad, and if the animal is a female the uterus will be seen resting
upon the rectum, and sending a prolongation—cornu or horn—
cephalad on each side toward the kidney.

PERITONEUM. : 279

ABDOMINAL VISCERA, SPECIAL STUDY.

§ 724. Names of Parts in the Order of Examination.—Perito-
neum; Diaphragma, diaphragm; Stomachus, stomach; Splen,
spleen; Intestinum tenue, small intestine (duodenum, jejunum,
ileum); Intestinum amplum, large intestine (cecum, colon, rec-
tum); Hepar, liver; Pancreas; Ren, kidney; Urocystis, urinary
bladder; Adrenal, suprarenal capsule ; Uterus, womb ; Ovarium,
ovary ; Vas deferens, spermatic duct.

Instruments and material the same as for the general study.

Specimen.—The same specimen may be used, or if a different
one is used, it should be prepared in the same way (§ 709).

PERITONEUM.

§ 725. Peritoneum.—The peritoneum is a serous sac lining the abdomen. It gives
the ental aspect of the abdominal wall its smooth, glistening appearance. It may be sep-
arated easily from the abdominal wall over a small area with the tracer.

The peritoneal sac is closed in the male, but in the female the Fallopian tubes open
into it, and hence it communicates, through these, with the exterior.

The mesenteries and the ligaments of the liver, urocystis and uterus are formed by
duplicatures of the peritoneum.

All the organs of the abdomen are really outside of the sac. The apparent presence of
some of the organs within it, and the way in which the mesenteries are formed, may be
readily understood from the following diagram (Fig. 78).

This diagram represents an ideal transection of the
cat’s abdomen at the level of the kidneys. The kidneys
(ven) are represented as projecting somewhat into the
abdominal cavity, and covered only on their ventral sur-
face by the peritoneum. The alimentary canal (Alt.
cand), shown also in cross section, is represented as
having moved far ventrad into the abdominal cavity,
carrying with it a fold of peritoneum which forms the
mesentery (§ 726).

§ 726. The word mesentery is often used in a general
way to indicate any of the duplicatures of peritoneum
supporting the intestines; but strictly speaking, the
term refers only to the duplicature of peritoneum sup-
porting the portions of the small intestine known as
jejunum and ileum. The proper term for the peritoneal
duplicature of any other part of the intestine is formed
by prefixing meso to the name of the part; thus, meso
duodenum, mesocolon, mesorectum, ete.

Fic. 78. —DIaGRAM SHOWING
THE RELATIONS OF THE
ABDOMINAL ORGANS AND
THE PERITONEUM.

As shown in Fig. 78, the mesenteries and ligaments are double
walled membranes. Demonstrate this by tearing away the mem-

280 ANATOMICAL TECHNOLOGY.

brane covering one side of a blood vessel. A similar membrane
will remain on the opposite side.

§ 727. Omentum majus, epiploon, az.—Caul (§ 716).—The epi-
ploon is a double walled sac formed by a duplication of a double
Sold of peritoneum. The cavity of this sac is sometimes called the
lesser peritoneal cavity. Demonstrate the sac-like character of the
omentum by tearing it open and divaricating the two walls. Dem-
onstrate that each wall of the sac is composed of two layers, as with
the mesentery, by tearing away one layer with the tracer. This
may be most easily and satisfactorily done over a blood vessel or a
strip of fat.

It will be seen from the above that the omental sac as it lies
collapsed on the intestines consists of four thicknesses of perito-
neum.

§ 728. Foramen Winslovii, az.—Foramen of Winslow.—This is
the contracted mouth of the omental sac through which it communi-
cates with the general peritoneal cavity. It is relatively larger than
in man, and may be easily demonstrated by tearing open the sac
near the pylorus, lifting the two walls slightly and divaricating
them. There will be seen within the sac a small lobe of the liver
(lobus Spigelii), and at the caudal margin of this lobe, sometimes
partly filled by it, will be seen the foramen. It is about 2 cm. in
diameter, and is on the dorsal side of the ductus communis chole-
dochus and Vena porte. The foramen may likewise be demon-
strated by turning the duodenum to the left and finding the ductus
choledochus and Vena porte. This should be done in a perfectly
fresh and uninjured specimen, and the omental sac inflated by
blowing into the foramen with a bent glass tube or a large flexible
blow-pipe.

§ 729. The Obvious Structure of the peritoneum is like that of serous membranes gen-
erally—thin and transparent, smooth and glistening.

§ 730. Microscopic Structure—{A) Ectal layer of a single thickness of flattened nu-
cleated cells. (B) Attached or ental layer of connective tissue containing elastic and
white connective tissue fibers. Consult Frey, A; Quain, A, Il, 197; Stricker, A, 569.

§ 731. Glandule Mesenterice, az—RMesenteric glands.——The
so called mesenteric glands belong to the lymphatic system. They
are between the layers of mesentery, and are especially large near
the cecum, some of them being 1-2 cm. thick and 8 em. long.

” .
ys

THE STOMACH. 281

§ 732. Corpuscula Pacini, az.—Pacinian corpuscles.—These are
oval bodies about 2 mm. long and 1 mm. thick. They are between
the layers of mesentery, and may be demonstrated, in lean cats, by
lifting the mesentery and looking through it toward the light. They
appear as translucent thickenings of the form and size mentioned
above.

§ 788. Microscopic Siructure.—(A) A connective tissue envelope. (B) Many concen-
trically arranged layers of translucent connective tissue. (C) A semifluid, richly nucleated,
central mass. (D) The termination of a single medullated nerve fiber. (E) A capillary
network of blood vessels. Stricker, A, 179; Quain, A, I, 150.

Det. choledochus
Communis a’,

Fie. 79.—SToMACH AND DUODENUM, VENTRAL VIEW; x1.

§ 734. Diaphragma, az.—Diaphragm (Fig. 90, § 712).—Draw
the stomach and liver somewhat caudad, and with a sharp scalpel
perforate the diaphragm, provided the thorax was not opened to
make the injection. This will allow the air to enter the thorax, and
the stomach, etc., may be kept in view. The diaphragm is fully
considered in § 816.

Preparation—Fig. 79.—The cat was fed a moderate amount of
solid food about an hour before death. After death, the stomach

282 ANATOMICAL TECHNOLOGY.

was filled from the duodenum moderately with 95 per cent. alcohol.
The omentum and mesentery were then carefully removed ; the
pancreatic and hepatic ducts isolated for a short distance ; the chol-
ecyst carefully separated from the liver ; then the cesophagus was
separated from the diaphragm and ligatured about 2 cm. cephalad
of it. The duodenum was also ligatured, and then the whole was
put into 95 per cent. alcohol for two days. The ventral portion was .
then removed, as shown, with a sharp scalpel, and the contents
washed out.

Description of Fig. 79.—Cholecystis.—Gall bladder. Curvatura major.—The
greater curvature of the stomach. Curvatura minor.—The lesser curvature of the stom-
ach. Dect. (ductus) hepatice—Hepatic ducts. Dect. (ductus) choledochus commp-
nis. Dct. Wirsung., Ductus Wirsungianus.—The pancreatic duct opening into the
ampulla of Vater. Dect. (ductus) Santorini.—The pancreatic duct opening independently
into the intestine. Duodenum.—§ 738. Flx. impd., Flexure impedentes.—The im-
peding flexures of the cystic duct. CEsophagus.—§ 735. Ppl. amp. Vtr., Papille
ampullz Vateri. Pylorus.—$735,C. Regio cardiaca.—The cardiac region, the region
next the diaphragm. Regio pylorica.—The pyloric region. Rugze.—Folds.

§ 735. Stomachus, az.—Stomach (Fig. 79, § 714).—Demonstrate
the following :—(A) The abdominal cesophagus. Turn the left lobe
of the liver cephalad, and the abdominal csophagus will be seen
emerging from the diaphragm and entering the cephalic or cardiac
end of the stomach.

From the nearly cephalo-caudal direction of the dorsal part of
the diaphragm, the dorsal side of the cardiac end of the stomach is
applied closely to it, and hence there is an abdominal csophagus
only on the ventral side.

(B) The stomach as a whole is pear-shaped and curved upon
itself. The curvatura major, or great curvature, faces sinistro-
caudad, and the great omentum is attached to it. The curvatura
minor, or lesser curvature, looks dextro-cephalad, and there is
attached to it the lesser omentum.

The larger or cardiac end is next the diaphragm and receives the
esophagus. The pyloric or smaller end is curved sharply upon
itself, and is partly concealed on its ventral side by the liver.

(C) Pylorus or pyloric valve (Fig. 79).—This is between the
stomach and small intestine. It usually appears as an annular con-
striction, and is firm to the touch. The pylorus in the cat, as in
man, is a ring-like fold of mucous membrane and a sphincter mus-
cle formed by an increase in thickness of the general layer of
circular muscular fibers of the alimentary canal.

THE SMALL INTESTINE. 283

The general appearance may be demonstrated by making a
longitudinal section of the pylorus and small intestine as shown in
Fig. 79. ,

$ 736. Obvious Structure of the Stomach.—With a scalpel, make a longitudinal incision
in the stomach along its entire ventral surface, and wash out the contents. With scis-
sors, cut out a piece of the stomach 2-3 cm. square. Look at the cut edge with a tripod
magnifier after observing it well with the naked eye. It will be seen to be composed of
two very obvious coats, an ectal, firm muscular coat, covered by the thin peritoneum, and
an ental, soft mucous coat. These are somewhat loosely connected together, and if the
stomach is empty or but slightly filled, the mucous coat will be thrown into folds or ruga,
mostly longitudinal in direction, by the contraction of the muscular coat.

Microscopie Structure, commencing ectad :—{A) Peritoneal or serous coat. (B) Muscu-
lar (unstriped) coat of :—(1) Ectal longitudinal layer; (2) intermediate circular layer ;
(8) ental oblique layer. (C) Submucosa, loose connective tissue coat. (D) Muscularis
mucosa, a thin layer of unstriped muscular fibers both circularly and longitudinally
arranged. (E) Mucous coat, with peptic glands. See Stricker, A, 370; Quain, A, II, 350.

§ 737. Splen, az.—Spleen (§ 715).—The relations, form and tex-
ture of the spleen should be carefully noted. It is one of the so
called ductless glands, and its functions are not well understood.

§ 738. Intestinum tenue, @z.—Small intestine (Fig. 77, § 717).—
The small intestine is arbitrarily divided into three regions: The
duodenum, the jejunum and the ileum.

(A) Duodenum.—That part of the small intestine along which the
pancreas extends is called the duodenum. It is held rather firmly
in position by a ligament from its caudal end. Into the duodenum
empty the ductus choledochus communis (Fig. 81 and 82) and the
two pancreatic ducts.

(B) Jejunum.—This is an ill-defined portion of the small intes-
tine immediately following the duodenum. It is so called because
in man it is often found empty after death.

(C) Zlewnm.—This is the caudal part of the small intestine, and is
a continuation of the jejunum, as that is of the duodenum. It ter-
minates in the large intestine, entering it obliquely. At its termina-
tion is the t4eo-cecal valve, which allows the alimentary contents to
pass from the small to the large intestine, but not easily in the
opposite direction. The action of this valve may be demonstrated
by cutting a slit in the small intestine 5-10 cm. cephalad of its ter-
mination, and injecting water caudad. The water will pass readily
into the large intestine.

Now cut a small slit in the large intestine and inject water toward
the small intestine. It will pass with difficulty into the small in-
testine.

284 ANATOMICAL TECHNOLOGY.

Preparation—Fig. 80.—A cat which has been well fed five or
six hours before death is best. The mesentery should be removed,
and about 10 cm. of the small and the same length of the large
intestine should be left with the caecum and ileo-cecal valve. The
contents of both large and
small intestine should be
caretully removed and the
large intestine ligatured.
Then both should be mod-
erately distended by inject-
ing 95 per cent. alcohol into
the small intestine. The
latter should then be liga-
tured and the whole put into
95 per cent. alcohol. After
two to three days the walls
may be removed with a
sharp scalpel.

Czcum, az.—See § 742, A. Colon,
az.—See § 742, B. Teum, az.—See
§ 738. Sphincter, az.—See § 739.
Villi.—See § 740, B. Valva ileo-czxca-
lis, a2.—lleo-ceecal valve. See § 739.

§ 739. Valva ileo-ceca-

Fra. 80.—C.zcum AND Inn0-cacaL VALVE, VEN- Jigs. The ileo-csecal valve in
TRAL View; x1. , ; . .
the cat is quite unlike its

homologue in man. In the cat it is a sphincter, composed of cireu-
lar muscular fibers like the pylorus, and like the pyloric valve it is
partly formed by an annular fold of mucous membrane, which in
the ileo-ceecal valve projects into the large intestine (Fig. 80).

The thickest part of the sphincter is about 1 em. cephalad of the
opening into the large intestine. The villi are not present caudad
of this point, hence about 1 cm. of the mucous membrane of the
small intestine of the cat is devoid of villi.

§ 740. Obvious Structure.—(A) Cut out two or three square cm, of any part of the
small intestine ; rinse it with water if necessary ; it will be seen to be composed of two
obvious coats like the stomach (§ 736).

(B) Villi intestinorum.—Put a fresh piece of intestine in a watch glass of water or
normal salt solution, and look at the mucous surface in profile. There will appear numer-
ous slender finger-like processes with their free ends pointing toward the lumen of the

2 THE LARGE INTESTINE. 285

intestine. These are the intestinal villi. They are only found in the small intestine, and
are most abundant in its cephalic portion.

The small intestine of the cat has no valvule conniventes (Quain, A, 259; Gray, A,
773); but it is completely invested by peritoneum throughout its whole extent. In these
two particulars it differs from the intestine of man,

§ 741. Microscopie Structure (A) Peritoneal or serous coat. (B) Muscular (unstriped)
coat :—({1) Longitudinal layer ; (2) circular layer. (C) Submucosa, areolar or loose con-
nective tissue coat. (D) Muscularis mucose of longitudinal and circular unstriped muscu-
lar fibers, some of which pass into the villi. (E) Mucous coat with villi and crypts of
Lieberkiihn, covered with columnar epithelium; Brunner’s glands and Peyer’s glands.
Quain, A, II, 358; Stricker, A, 380.

§ 742. Intestinum amplum, a2.—Large intestine (Fig. 77, § 719).
—The large intestine is the part of the alimentary canal extending
from the czecum to the anus, the caudal opening of the canal. For
convenience of description, the large intestine is divided into four
parts, named in order :—Cacum, colon ascendens, colon transver-
sum, colon descendens and rectum or terminal part.

Exposure.—Turn the small intestine toward the left leg.

(A) Cecum (Fig. 80).—This is the somewhat conical blind sac at
the beginning of the large intestine. It lies on the right side and in
about the middle of the abdoiinal cavity.

(B) Colon ascendens—-Ascending colon.—This is the part of the
large intestine which extends cephalad from the cecum.

Respecting the use of the terms cephalad and caudad in desig-
nating the position or direction of parts of the alimentary canal,
see § 91.

Topographically, the colon ascendens extends cephalad from
the czcum, but physiologically, that is, in respect to the passage
of the contents, the entire colon is eaudad of the cecum.

It is quite short, and reaches nearly to the pylorus. Its dorsal
surface is in contact with the duodenum.

(C) Colon transversum—Transverse colon.—This is the continua-
tion of the preceding. It extends transversely across the abdomen
just caudad of the stomach. ~

(D) Colon descendens and rectum.—After extending nearly
across the abdomen from right to left, the large intestine passes
obliquely caudad, soon reaching the meson. It then extends cau-
dad along the vertebral column to terminate at the anus. The last
and straighter part is called the rectum.

§ 743. Obrious Structure of the Intestinum amplum.—if the large intestine is full of
feces, press the contents of a small part of the colon transversum aside and cut out a piece

286 ANATOMICAL TECHNOLOGY.

1-2 em. square. Rinse the mucous surface with water or normal salt solution. The
structure will appear like that of the small intestine except that villi are absent.

Microscopic Structure of the Intestinum amplum.—(A) Peritoneal or serous coat. (B)
Muscular (unstriped) coat :—({1) Longitudfhal layer ; (2) circular layer. (C) Submucosa,
loose connective tissue coat. (D) Muscularis mucose, unstriped muscular fibers arranged
both longitudinally and transversely. (E) Mucous coat, containing crypts of Lieberkiihn
and Peyer’s glands.

The large intestine of the cat is completely invested by peritoneum, and is supported
by a duplicature of the same ; hence in these respects it differs somewhat from man. See
Stricker, A, 391; Quain, A, II, 371.

§ 744. Hepar, az.—Liver (Fig. 77, § 713).—Grasp the liver with the
hand and draw it in various directions. It is deeply divided (lobed)
and is supported in various parts by folds of peritoneum, the so
called ligaments of the liver.

Lobi hepatici.—The lobes of the feline liver have not been satis-
factorily homologized with those of the human liver, and the nomen-
clature is somewhat unsettled. (Owen, A, III, 485; Flower, 41).
For convenience, the following provisional names may be used :—

(A) Lobus sinister.—This part of the liver is at the left of the
suspensory ligament (the ligament parallel with the meson and serv-
ing to hold the liver against the diaphragm). This lobe is deeply
divided, and its caudal or thin edge is on the ventral side of the
pyloric region of the stomach (Fig. 79).

(B) Lobus cysticus—Cystic lobe.—This is at the right of the sus-
pensory ligament, and occupies the right ventral part of the abdo-
men. It contains the cholecyst or gall bladder, and hence cannot
be mistaken. It is in some cases deeply divided, and in others only
slightly.

(C) Lobus dexter—Right lobe.—This is dorsad of the cystic lobe.
It is usually deeply subdivided, and is in contact with the ventral
aspect of the right kidney.

(D) Lobus Spigelii.—This is the smallest of the lobes of the liver.
It is dorsad of the left lobe and dextro-cephalad of the lesser curva-
ture of the stomach. It usually appears at the mouth of the fora-
men of Winslow, and may be fully exposed by tearing away the
peritoneum (§ 728) at the lesser curvature of the stomach.

§ 745. Cholecystis—Gall bladder.—This is a receptacle for bile,
and as stated above is partly imbedded in the cystic lobe. It isa
pear-shaped sac, and the larger end usually appears on the ventral
surface of the cystic lobe (Fig. 77). To expose it fully, turn the free
edge of the cystic lobe cephalad.

DUCTS OF THE LIVER. 287

§ 746. Ductus hepatici—Bile ducts.—Press on the cholecyst,
and the contained bile will be forced into the various b7le ducts :—

(1) Ductus cysticus.—This is the duct extending from the small
end of the cholecystis to the ductus communis (3). It presents sev-
eral loops, the so called impeding flecures, and serves to conduct
the bile to or from the cholecyst (Fig. 79, 81, 82).

(2) Ductus hepatici (Fig. '79).—These are the bile ducts proper.
They convey the bile from the various lobes of the liver to the duc-
tus communis (Fig. 79, 81). Press on the cholecystis again if neces-
sary to make them evident. Isolate one by means ‘of the tracer.
Cut a V-shaped slit in it near its end and press all of the bile in the
cholecyst out through the slit. Then insert a canula through this
slit and inject toward the cholecyst with plaster (§ 359). This will
fill all the ducts as well as the cholecyst, and after the plaster has
set they may be traced in the same way as arteries, (§ 596 [10]).

(83) Ductus choledochus communis—The common bile duct.—
As the name implies, this receives all of the other ducts from the
liver. It appears to be a continuation of the cystic duct. It reaches
the duodenum about 3 cm. from the pylorus, and enters it obliquely
caudad. Within the walls of the duodenum, it empties into a small
reservoir (ampulla of Vater), common to it and the duct of Wir-
sung (Fig. 84).

The character of the opening of the ductus choledochus and its
relation to the ductus Wirsungianus are shown in Fig. 84.

§ 747. Obvious Structure of the Liver (hepar).—(A) Lobi.—The liver is composed of sev-
eral deep red lobes, which are smooth and shining on the surface from the presence of the
peritoneal investment. This is very thin and is separated with difficulty, even over small
areas.

(B) Lobuli—Lobules.—These are plainly visible as small areas about 1 mm. in diam-
eter, surrounded by rings of deeper color.

(C) Parenchyma.—lIf a piece is cut out, it may be readily crushed into a pasty mass,
showing that the structure is pulpy and cellular rather than fibrous.

§ 748. Microscopic Structure—(A) Peritoneal or serous coat. (B) Fibrous coat (pro-
jections of this accompany the vessels). (C) Liver substance; this consists of lobules
composed of polyhedral cells arranged in a radiate manner around the center of the lobule.

Vessels of the Lobule—(1) Intralobular vein or hepatic veinlet in the center of the lob-
ule ; (2) Interlobular or portal veinlet and the hepatic arteriole. These are between the
lobules, and capillaries pass from them to the center of the lobule between the rows of
hepatic cells. In addition to the above, are the beginnings of the hepatic ducts. See
Stricker, A, 407; Quain, A, II, 386.

§ 749. Pancreas, az. (Fig. 81, § 720).—The cat?s pancreas is
greatly elongated, and so bent as to form two sides of a triangle.

288 ANATOMICAL TECHNOLOGY.

From the relations of the two parts, they are called respectively the
gastro-splenic and the duodenal parts of the pancreas (Owen, A,
III, 495). The organ is wholly enveloped by peritoneum, thus dif-
fering from the human, which is covered by peritoneum only on its
ventral surface.

In order to expose the pancreas fully, the ventral wall of the

great omentum should be removed, and the large and small intes-
tines should be drawn caudad.

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Like the human pancreas, that of the cat has two ducts—Ductus
Wirsungianus and Ductus Santorini—which open separately into
the intestine, although they anastomose in the substance of the
pancreas (Fig. .81-83).

Preparation—Fig. 81.—The great omentum, the jejunum, ileum,

CHOLECYSTIS AND PANCREATIC RESERVOIR. 289

colon and liver were removed ; the remaining parts shown in situ.
The duct of Wirsung was afterward injected with Berlin blue, and
both it and the duct of Santorini dissected out to show their branches
and anasio.noses.

Explanation of Fig. 81.—1. Pyloric region of the stomach.

2. Pylorus. 2-3. The ducdenum.

4. Gastro-splenic division of the pancreas, near the main branch of the duct of Wirsung.

5. The duodenal part of the pancreas and branch of the duct of Wirsung.

6. Duodenum at the point where the duct of Santorini pierces its walls. The dotted
line shows the extent of the pancreas on the dorsal side of the intestine. The duct of San-
torini is seen to anastomose with each division of the duct of Wirsung.

7. Ductus communis choledochus.

8. The point where the ductus choledochus and the duct of Wirsung enter the
duodenum.

9. Tip of the spleen, somewhat dispiaced.

10. The superior mesenteric artery sending the inferior pancreatico-duodenal branch to
tose parts.
11. Superior mesenteric vein receiving a corresponding branch.

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19

290 ANATOMICAL TECHNOLOGY.

ing the concave side up ; the duodenum to the left, so that its right
side looks directly upward ; it was then sliced off to the ievel of the
ampulla of Vater and the duct of Santorini.

Explanation of Fig. 82.—1. Pylorus.

2. The duct of Santorini passing obliquely through the duodenal walls.

3. Cut end of the inferior pancreatico-duodenal artery.

4. Same for the corresponding vein.

5. The duodenal branch of the duct of Wirsung.

5. Cut end of the duodenal pancreas, showing triangular section, and the intestine
partly enveloped by it.

6. The ampulla of Vater.

7. The duct of Wirsung, opening into the ampulla.

8. The ductus communis choledoclus, also opening into the ampulla.

9. The duodenal branch of the duct of Wirsung.

10. The gastro-splenic branch displaced.
11. Duct from the pancreatic reservoir opening by a large branch into 10, and by a small
one into 7.

12. Pancreatic reservoir covering part of
the cholecyst.

13. The “impeding flexures” in the
cystic duct.

14. The cholecystis constricted in the
middle, as is aiso the pancreatic reservoir,
by a firm wide band passing over them.

15, 15. The cystic lobe of the liver.

Preparation—-Fig. 83.—The
ventral wall of the duodenum
was partly removed to show the
openings of the ducts, which had
been exposed by dissection.

Explanation of Fig. 83.—1. Pylorus.

2and 4. Duct of Wirsung.

3. Duct of Santorini anastomosing freely
Fig. 83.—VENTRAL VIEW OF THE HUMAN with the preceding, and opening into the

Pancreatic Ducts. (After Bernard, jntestine between the aperture of the am-
17). x5. pulla of Vater and the pylorus.
5. Ductus communis choledochus.
6. Opening of the duct of Santorini at the summit of a papilla.
7. Opening of the ampulla at the summit of a similar papilla. These openings are
usually about 10-15 mm. apart.

§ 750. Ductus Wirsungianus—Duct of Wirsung, principal pan-
creatic duct.—This, in the cat, is usually the larger of the two
pancreatic ducts, as in man. It opens into a small reservoir, am-

AMPULLA OF VATER. 291

pulla of Vater, within the walls of the duodenum. The ampulla
appears as an oblique elevation on the ectal surface of the duode-
num, and receives also the ductus communis choledochus (Fig. 84).

Preparation—Fig. 84.—The duodenum should be suspended in
95 per cent. alcohol for 2-3 days, or it may be hardened in Muiler’s
fluid (see Frey, A). Then rather thick treehand sections may be
made with a razor or a very sharp scalpel. The sections may be
studied to advantage with a tripod lens or with a 3-in. objective
and a compound microscope.

Fig. 84.—LONGITUDINAL SECTION OF THE AMPULLA OF VATER, SHOWING THE ENTRANCE
OF THE Ductus CHOLEDOCHUS AND THE Duct oF Wirsune; x84. A and B—
SIMILAR SECTIONS OF THE AMPULLA OF VATER IN MAN. (A anc B, after Claude
Bernard, 17). x1.75.

Explanation of Fig. 84.—Ampulla, Ampulla of Vater.—The sac-like space in the
wall of the duodenum into which open the ductus choledochus and the ductus Wirsungi-
anus. The ampulla is not a free space, but is more or less filled by anastomosing processes
springing from the walls. The ampulla opens into the duodenum through a single orifice
on the summit of a slight papilla.

Det. child. cmn., Ductus choledochus communis, az.—The common bile duct.—It is
seen to have its lumen partly filled with anastomosing processes which allow the bile to
flow into the ampulla, but tend to prevent any regurgitation.

Dect. Wirsung., Ductus Wirsungianus, az.—Duct of Wirsung.—The pancreatic duct
emptying into the ampulla of Vater. In the cat it is usually much larger than the duct
of Santorini (Fig. 81-88).

292 ANATOMICAL TECHNOLOGY.

Mucosa.—The mucous membrane of the small intestine.

M. circularis.—The circular layer of unstr'ped muscle. ,

M. longitudinalis.—Tle longitudinal layer of unstriped muscles.

Ost. am>. Vtr., Ostium ampullz Vateri, az.—The opening or mouth of the ampulla
of Vater.

Submucosa.—The layer of connective tissue between the circular muscle and the
muscularis mucose.

Fig. 84, A and B.—Dct. chld., Ductus choledochus communis, az.—The common
bile duct.

Dct. W., Ductus Wirsungianus.—The pancreatic duct opening into the ampulla of
Vater. In A, both ducts open at the bottom of tue ampulia. This is said by Bernard to
be the normal condition. In B, the bile duct extends nearly to the orifice of the ampulla,
es in the cat. This is not common in man, although normal in the cat.

§ 751. Demonstration of the Duct of Wirsung, the terminal
part of the Ductus choledochus, and the Ampulla of Vater.

Turn the duodenum to the left and trace the ductus choledochus
to its point of entrance into the intestine. Now remove the perito-
neal covering on the dorsal side of the pancreas just caudad of the
termination of the ductus choledochus. Then tear away the sub-
stance of the pancreas very carefully, and the duct will be exposed.
It looks like an uninjected blood vessel. Trace it for some distance
from the intestine and it will be found to divide into two main
branches, one for each part of the pancreas (Fig. 81-83). Open the
duct about 1 cm. from its point of entrance into the intestine, and
pass a beaded bristle into it- toward the intestine. With a sharp
scalpel, slice away the intestine over the point of entrance of the
ductus choledochus communis and the ductus Wirsungianus, mak-
ing the slices parallel with the direction of the two ducts. Continue
the cutting until the plaster in the ductus choledocbus and the
bristle in the ductus Wirsungianus are exposed. It will be seen
that the two ducts penetrate the intestinal wall obliquely caudad,
and open separately into the ampulla (Fig. 84). The ampulla then
opens through a slight papilla into the lumen of the intestine.

Contrary to the common statement, the two ducts cannot be said
to unite at all (Gage, 3, 177).

In some respects it is better to employ a specimen whose hepatic
ducts have not been injected with plaster to demonstrate the rela-
tion and termination of the two ducts. In this case a bristle should
be put into each.

(B) Ductus Santorini—Losser pancreatic duct (Fig. 83).—This,
in the cat, is usually much smaller than the preceding, and hence
its demonstration is more difficult. It opens on the left side of the

THE KIDNEYS. 293

intestine obliquely caudad of the preceding, and is demonstrated
by tearing away first the peritoneum and then the pancreatic sub-
stance. The anastomosis of the two pancreatic ducts may be dem-
onstrated by injecting the ductus Wirsungianus peripherad with
Berlin blue.

§ 752. Obvious Structure of the Pancreas.—It is composed of a great many small lob-
ules arranged like a bunch of grapes, the ducts representing the stems of the grapes.
Such glands are said to be racemose.

§ 753. The Microscopic Structure as well as the obvious structure is in all essential
particulars like that of the salivary glands ($§ 788, 789). See Stricker, A, 295; Quain, A,
II, 396.

Fria. 85.—Dorso-VENTRAL SECTION Fic. 86.—LONGITUDINAL DEXTRO-SINISTRAL
OF THE RriqutT KIpNEY, CAUDAL SECTION OF THE RigHT KIDNEY, VEN-
Virw; x1.1. TRAL VIEW; x1.1.

Preparation—Fig. 85, 86.—The ureter and pelvis were inflated
by injecting 95 per cent. alcohol through the ureter toward the kid-
ney. Then the ureter was ligatured and the kidney carefully
removed and placed in 60 per cent. alcohol for two days, then in
95 per cent. alcohol for the same time. When well hardened it
was sliced off to the level shown in the figures.

Explanation of Fig. 85, 86.—Hilum.—The concavity of the mesal border of the kid-
ney. It is at this point that the ureter and the blood vessels enter.

Papilla.—The apex of the medullary portion. From its free end the urine exudes.
There is but one papilla in the cat. In Fig 86, the medullary portion seems to end by
several papille, but the pyramids forming these converge at a higher level than here
shown, and finally end as shown in Fig. 85.

Pelvis.—The somewhat dilated space into which the papilla opens.

Substantia medullaris.—The medullary or central part of the kidney

Tunica fibrosa (Fig. 85).—The thick fibrous sac enclosing the kidney. It is reflected
into the hilum and upon the ureter.

294 ANATOMICAL TECHNOLOGY.

§ 754. Ren—Kidney (Fig. 77, 78, 85, 86, 101, 103, § 722).—Turn
the stomach and the intestines to the right, and the left kidney will
be exposed. Remove any fat*that can be removed without displac-
ing the kidney. Its lateral aspect is convex, while the mesal one
presents a deep concavity, the so called hilum of the kidney.

The right kidney is somewhat farther cephalad than the left,
thus differing from man. Only the ventral surface is covered with
peritoneum (Fig. 78); but the entire kidney is surrounded by a
special fibrous capsule or covering (Fig. 85).

Obvious Structure of the Kidney.—With a sharp scalpel, make a longitudinal dextro-
sinistral section of the kidney, removing the ventral three fifths. The appearance shown
in Fig. 86 will appear.

The wreter (§ 756) commences as a funnel-shaped opening from the hollow or pelvic
part of the kidney (Fig. 85, 86).

The solid part of the kidney is evidently composed of two portions—the ectal, periphe-
ral or cortical, and the ental, central or medullary portions. The cortical or peripheral
pertion is granular and of a deep color, while the medullary portion is lighter in color,
smooth, compact, and of more or less triangular outline. The apex projects into the peivis
of the kidney and is called the renal pap'la. There are several in man, but only one in
the cat.

§ 755. Microscopie Structure—{A) Tubuli uriniferi, or urinary tubules—tubes lined
with cells and forming the kidney substance proper. (B) Blood vessels and lymphatics.
(C) Nerves and connective tissuc.

In the medullary part of the kidney, the blood vessels and urinary tubules are mostly
straight in direction, while in the cortical portion they are looped or convoluted ; both
vessels and tubules are branched. The arteries form the so called glomeruli or Malpighian
corpuscles by a multiple knotting at their termination. See Stricker, A, 460 ; Quain, A,
If, 406.

§ 756. Ureter.—Grasp the kidney with one hand and the uro-
cyst (Fig. 101) with the other. Draw the former cephalad and the
latter caudad. There will be seen, stretching between the kidney
and the neck of the urocyst, a narrow tense band, more or less cov-
ered with fat. This band is the wrefer, or duct conveying the urine
from the kidney to the urocyst.

Sometimes one may inflate the urocyst by blowing into the renal
end of the ureter, but usually the ureter is too greatly contracted.
The tubular character of the latter may be easily demonstrated,
however, by using a beaded bristle (§ 136) or by commencing at the
kidney and slitting it with fine scissors.

§ 757. Urocystis, vesica urinaria—Urinary bladder (Fig. 77,
101, § 718).—This is the receptacle for the urine.

A. Ligamentum suspensorium.—Grasp the cephalic or larger
free end of the bladder and draw it ventro-caudad. A thin mem-

THE UROCYST OR BLADDER. 295

brane like the mesentery will be seen between it and the ventrime-
son, the ligamentum suspensoriwm. It is formed of a duplicature
of peritoneum, and in young animals there may be seen between
its two layers the remnants of the hypogastric arteries and of the
_urachus (Gray, A 812; Quain, A, II, 800).

B. Ligamentum laterale-——In addition to the suspensory liga-
ment, one having the same general appearance will be seen on each
side.

C. Cervix urocystis—Neck of the urinary bladder.—Draw the
urocyst caudad and its fixed point will be seen to grow narrow.
This narrow part is the neck, and its continuation to the exterior is
called the urethra or excretory canal of the bladder. The ureters
penetrate the urocyst on each side of the neck ; their course through
the wall is quite oblique, as may be demonstrated by passing a
bristle from the ureter into the bladder.

§ 758. Obvious Structure of the Urocyst—Cut a slit in the urinary bladder to allow the
urine to escape, then cut out a piece about 2 cm. square. Rinse it with water or normal
salt solution. There may be demonstrated a structure somewhat comparable to that of
the stomach :—(A) An ectal serous (peritoneal) coat. (B) An intermediate firm or museu-
tur coat. (C) An ental soft or mucous coat. The muscular and mucous coats are, how-
ever, more closely united than in the stomach.

§ 759. Microscopic Structure.—(A) Serous (peritoneal) coat. (B) Muscular (unstriped)
coat :—(1) Longitudinal layer ; (2) circular layer ; (8) longitudinal layer. The three layers
are arranged somewhat in the form of a figure of—8. (C) Submucosa of loose connective
tissue. (D) Mucous coat covered with stratified epithelium. See Stricker, A, 487; Quain,
A, IT, 423.

§ 760. Adrenale—Capsula renalis, capsula suprarenalis.—Turn
the stomach and intestines to the right. About 2 cm. meso-cephalad
of the kidney will appear a pinkish, oval body about 2 cm. long
and 1 cm. wide. Its caudal end is usually in contact with the V.
renalis and its ventral surface is crossed by the V. adreno-lumbalis
(Fig. 101, adrn.).

The right adrenal is in about the same position with respect to
the right kidney ; but as the V. cava and part of the liver are on its
ventral surface, it is not so easily demonstrated as the left.

Both adrenals are covered on their ventral surface by perito-
neum. Neither of them is in contact with the kidney. In this
respect they differ from their human homologues.

§ 761. Uterus—-W omb (§ 723).—TIf the cat is a female, there will
appear between the rectum and the urocyst a mesal organ, the
uterus, having the same general color and appearance as the intes-

296 ANATOMICAL TECHNOLOGY.

tines. It is a hollow organ and at its cephalic end bifurcates,
forming the so called cornua or horns of the uterus. The horns
extend obliquely latero-cephalad nearly to the caudal extremity of
the corresponding kidney (Fig. 77).

§ 762. Tuba Fallopiana—Fallopian tube, Oviductus.—Near the -

ends, the horns of the uterus become quite small and more or less
convoluted. This small part of the horn is called the oviduct or
Fallopian tube. It, opens directly into the peritoneal cavity, thus
putting the peritoneal cavity in communication with the exterior of
the body. The end is somewhat funnel shaped and one edge is
applied to the ovary. Quain, I, 470.

Make an incision in one of the cornua near the beginning of the

Fallopian tube and pass a beaded bristle into the uterus, and then
along the Fallopian tube throughout its whole extent. This will be
facilitated by severing the connections of the tube so that it may be
straightened.

§ 763. Ligamentum uteri.—Grasp a uterine cornu and lift it up.
A broad membranous band will appear extending laterad from it.
This is the ligamentum latum or broad ligament of the uterus and
its horns. Like the mesentery and ligaments of the urocyst, it is
simply a duplicature of peritoneum.

Ligamentum rotundum—Round ligament.—Look through the
ligament toward the light ; a thickening will appear in it extending
from near the middle of the horn caudad to the abdominal wall
ventrad of Poupart’s ligament (Fig. 39). This is the round ligament,
and may be traced through the abdominal wall. It terminates in
the external organs of generation.

§ 764. Obvious Structure—(A) Serous (peritoneal) coat. (B) Muscular coat. (C) A
soft mucous coat. These points may be easily demonstrated by cutting out a small piece
of the uterus or one of its horns.

§ 765. Microscopie Structure.—(A) Serous (peritoneal) coat. (B) Muscular (unstriped)
coat ; the fibers greatly interlace and are mixed with abundant connective tissue. (C)
Mucous coat. See Stricker, A, 606; Quain, A, IT, 464.

_ § 766. Ovarium—Ovary.—At the cephalic end of each Fallo-
pian tube (§ 762) may be seen the ovary, a yellowish oval body
about 1 em. long and .5 cm. wide. It is supported by an exten-
sion of the broad ligament.

§ 767. Microscopie Structure-—(A) Modified peritoneal coat. (B) Ovarian stroma—
connective tissue, blood vessels and nerves, Graafian follicles with the ova. See Stricker,
A, 510; Quain, A, II, 472.

THE SALIVARY GLANDS. 297

§ 768. Vas deferens.—If the subject is a male, there will be seen
on each side a white cord, the oas.deferens or spermaduct (Fig. 101),
looping around the ventral side of the ureter and A. hypogastrica,
and then extending toward the urethra.

If the vas deferens is traced peripherad, away from the urethra,
it will be seen to penetrate the abdominal wall laterad of the A.
epigastrica and ventrad of Poupart’s ligament.

In traversing the abdominal wall, it passes through the canalis
inguinalis. It is accompanied by the spermatic artery and vein
and a duplicature of peritoneum, and all together form the sper-
matic cord. The opening of the inguinal canal within the abdomi-
nal cavity is called the annulus abdominalis internus or the internal
abdominal ring, while the one on the ectal surface of the abdominal
wall is called the annulus abdominalis externus or external ab-
dom:nal ring (Fig. 39).

From the external abdominal ring, the spermatic cord extends
obliquely caudad and entad of the skin to the éeséis.

THE SALIVARY GLANDS, MOUTH CAVITY, PHARYNX,
NECK, THORAX AND DIAPHRAGM.

§ 769.—Names of Parts in the Order of Examination.—Glandula parotis—Ductus Ste-
nonianus —Glandula submaxillaris—Ductus Whartonianus — Lingua — Pharynx — Tuba
Eustachiana — Larynx — Trachea — sophagus — Pleura — Thymus — Pulmo—Cardia—
Diaphragma.

The vessels and nerves of these parts are treated in Chap. VIII and IX.

§ 770. Instruments and Material the same as for the abdomen with the addition of a
saw (Fig. 21), nippers (Fig. 11), beaded bristles (3§ 136), and about 100 cc. of the Berlin
blue solution.

Choicz of Specimen the same as for the abdomen.

SALIVARY GLANDS.

§ 771. References.—Quain, A, II, 3385; Gray, A, 757; Bernard, A, 504; Chauveau,
A, 387; Leyh, A, 372; Owen, A, TI, 396; Cuvier, A, III, 409; Hyrtl, A, 241: Gegen-
baur (Lankester), A, 519; Milne-Edward:, A, VI, 220; Chauveau (Fleming), A; Gurlt,
A, 361.

§ 772. Posture and Preparation.—The cat should be dorsicum-
bent, with a block crosswise under the neck, and the head rotated
dextrad so that the side of the face looks upward ; the mouth should
be held open with a cork. The animal should be injected from the
femoral artery, making the plaster somewhat thinner than usual
($$ 345, 352). The femoral vein should be injected with blue plas-

298 ANATOMICAL TECHNOLOGY.

ter (§ 362). If the abdomen is not to be used (§ 234), it is easier to
inject from the postcava and the aorta (§§ 363, 365).

As plaster will not pass the valves in the veins, it is best for this
preparation, as for Fig. 101, to inject the jugular vein with fine blue
mass (see § 1450) instead of blue plaster. This is only necessary,
however, for permanent preparations or for special demonstrations.

§ 773. Salivary Glands.—The salivary glands are the organs,
belonging to the digestive system, which secrete the saliva and pour
it into the oral cavity through single or multiple ducts. They are
situated in close proximity to the mouth and mostly just entad of
the skin. There are 5 on each side :—Parotid, submazillary, sub-
lingual, molar, zygomatic.

§ 774. Preparation of the Ducts of the Salivary Glands.—
These should be injected with Berlin blue (see § 1449), or if that is
not at hand, there may be used a sufficient quantity of chrome
green or orange ground in 15 per cent. glycerin to give a decided
color. As the process of injection is somewhat troublesome, the
ducts may be demonstrated by inserting into them beaded bristles.

§ 775. Preparation of Wharton's Duct.—This opens on the’
summit of a prominent papilla situated in the floor of the mouth
just cephalad of the frenum (Fig. 88). It usually lies on the floor
of the mouth. Grasp it near its free end with the fine forceps, and
enlarge the opening with the probe of the tracer; then insert a
beaded bristle or the canula for injection (§ 358).

Injection.—The canula need not be tied, but merely compressed
with the fingers while injecting. Before commencing the injection,
the canula should be filled with the injecting mass to avoid air. In
making the injection, the pressure should be light and continued for
but a short time lest the duct be ruptured. If the injection is suc-
cessful and the tongue be turned to the opposite side, the duct may
be seen in the floor of the mouth extending nearly parallel with the
mandibular ramus as far caudad as the last tooth.

§ 776. Preparation of Stenon’s Duct.—With coarse forceps or
the fingers, grasp the dorsal lip near the angle of the mouth and
draw it laterad so as to expose the mucous membrane opposite the
last premolar tooth (Fig. 61). Just cephalad of the angle of the
mouth and opposite the most prominent cusp of the last preemolar
will be seen a slight ridge on the mucous membrane. ‘The cephalic
end of this ridge is about 1 em. from the edge of the lip, and at the
end will be seen a slight circular depression, which is the opening

THE SALIVARY GLANDS. 299

of the duct. Enlarge the opening with the probe of the tracer, and
insert a beaded bristle or a canula for injection. Inject as directed
for W harton’s duct (§ 775).

§ 777. Exposure of the Salivary Glands and their Ducts.—
Divide the skin as follows:—(A) Along the mesal border of the
mandibular ramus from the canine tooth directly caudad as far as
the caudal end of the larynx. (B) From the caudal end of the
incision (A) to a point opposite the meatus auditorius eaxternus.
(C) From the maxillary canine to the dorsal border of the ear. (D)
Along the edge of the lips from the mandibular to the maxillary
canine, leaving a narrow band of skin with the lip.

Exposure of the Glands, etec—Commence at the angle next the
larynx (ventro-caudal angle) and dissect the skin free. Use a sharp
scalpel and dissect close to the skin. Then commence at the same
point and dissect free the thin dermal muscle (§ 608) in the same
manner that the skin was dissected. It is necessary to take the
greatest care in removing the muscle in order to avoid injury to
nerves and vessels. Remove the caudal part first, thus exposing
the glands and larger vessels and nerves, which are more easily seen
than their branches. Compare the appearances presented with
those shown in Fig. 67. If the gland ducts were injected with fine
mass, the glands will be of the same color as the mass used. The
duct of the parotid (Fig. 87) will be very conspicuous and will serve
as a kind of landmark. The same is true of the V. jugularis (Fig.
87, 101).

In exposing and isolating nerves and vessels in this preparation,
it is necessary to work with the greatest care. The sharp tracer
cannot be used as safely as in most cases. Use the dull tracer, fine
forceps and scissors, and remove fat and connective tissue piece-
meal. So many branches of the nerves enter the dermal muscle
that it is necessary to dissect it very carefully, so as not to remove
at the same time the larger branches of the nerves.

Explanation of Fig. 87.—A. fac., A. facialis.—Facial artery ;
a branch of the carotid. Ductus Stenon. (Stenonianus).—Stenon’s
duct ; duct of the parotid gland. Glandula parotis.—The parotid
gland, the largest of the salivary glands. Gl. (Glandula) submax-
illaris.—The submaxillary gland. Gl. m., Glandula molaris.—
Molar gland. Mandible.—Inferior maxilla, lower jaw. M. clv.
(clavo-) trapezius (Fig. 66). IM. sterno-mstd. (mastoideus) (Fig.

300 ANATOMICAL TECHNOLOGY.

72). IM. tmp., M.temporalis. M.mstr., M. masseter (Fig. 67).—
Masseter muscle. WN. aur. (auricalaris) magnus, N. tmp. fac., N.
temporo-facialis.—Branches of the temporo-facial division of the
facial nerve (vii). N. crv. facial., N. cervico-facialis. —Cervico-
facial division of the facial nerve (vii). N. tmp. aur., N. temporo-
auricularis.—Branches of the temporo-auricular division of the

Fig. 87.—SALIVARY GLANDS 0° THE LEFT SIDE; xl.

trigeminus nerve (v). Pili tactiles.—Tactile hairs. There are
usually 5-8 of these. They are supplied by branches of the ¢i-
geminus nerve (vy) and are supposed to be tactile hairs. VWibrissee.—
Whiskers. These stiff hairs are likewise supplied by branches of
the trigeminus nerve and are also supposed to be tactile organs.
V. facialis —Facial vein. A branch of the external jugular vein.
V. jugularis externa.—The external jugular vein. It almost inva-

NERVES OF THE FACE. 301

riably lies between the parotid and submaxillary and separates
the latter from the lymphatic immediately cephalad of it. Zygoma,
arcus zygomaticus.—The zygomatic arch (Fig. 56).

For the manner of preparation, see $$ 772, 777.

§ 778. Nerves.—Cervicofacial division of the facialis (vii)
(Fig. 87).—This emerges from the ental surface of the lymphatic
gland (Fig. 87, Gl. lym.), crosses the V. facialis and divides into the
two main divisions, one of which extends along the nandible, the
other dorso-cephalad toward tle angle of the mouth.

TemporojSacial division of the facialis (vii) (Fig 87, N. tmp.
fac.).—About 1 em. dorsad of the parotid duct there emerges an-
other branch which extends dorso-cephalad and spreads out in
many branches over the side of the head and face.

Temporo-auricular division of the trigeminus (branch of the 5d
or in‘erior division of the V nerve).—It has the same general direc-
tion as the temporo-facial branch of the facialis and anastomoses
ireely with it. Its fine branches spread out over the head and iace
as do those of the temporo-facial

At the dorso-cephalic angle of the parotid emerges another
branch of the temporo-auricular (Fig. 87, N. tmp. aur.}. It extends
almost directly dorsad.

Auricular is magnus (Fig. 87).—This large spinal nerve emerges
from between the JZIL. clavo-trapezius and sterno-mastoideus. lt
tien extends dorso-cephalad and spreads out over the cauda! sur-
face of the external ear.

GLANDULZ SALIVARLA.

§ 779. Glandula parotis—Parotid gland —The position and
relations of this gland are well shown in Fig. 87. It surrounds the
ventral half of the external ear.

§ 780. Ductus Stenonianus—Stenon’s duct, duct of the parotid
gland (Fig. 87).—It extends cephalad from the cephalic edge of the
gland along the ectal surface of the masseter muscle, nearly directly
toward the angle of the mouth. When near the edge of the lip it
penetrates the cheek, passing entad of the facial vein (Fig. 87, V.
facialis). It opens on the mucous surface of the cheek opposite the
most prominent cusp of the last preemolar (Fig. 57).

Isolate the duct as directed for nerves and vessels (§ 777). It
may be easily traced if it has been injected or if a black bristle has

302 ANATOMICAL TECHNOLOGY.

been inserted. Near the gland it will be seen to divide into several
branches.

§ 781. Glandula parotidea accessoria — Accessory parotid
gland.—In about one subject in ten there may be found one or
more small glandular masses connected with the parotid duct.
These are sometimes in contact with the duct at some point of its
course over the masseter, or they may be separated for a centimeter
or more; if separated, a slender duct connects them with the main
duct. Mivart, B, 173.

§ 782. Glandula submaxillaris—Submaxillary gland Wie. 87).
The submaxillary gland is ventrad and partly entad of the parotid.
its cephalic edge is also covered by the lymphatics. The lobula-
tions of the submaxillary are coarser than those of the parotid ; and
if uninjected it is of deeper color.

§ 783. Ductus Whartonianus—Wharton’s duct, duct of the
submaxillary gland.—In order to expose this, the lymphatics and
the vein should be removed. The duct appears at the cephalic bor-
der of the gland, and extends almost directly dorsad, passing be-
tween the IM. digastricus (Fig. 101) and masseter (67), until it
reaches the floor of the mouth opposite the last tooth. In its pass-
age between the muscles, its lateral surface is crossed by the gusta-
tory branch of the WV. trigeminus (v).

Exposure.—Divide and reflect the JZ. digastricus (Fig. 101);
then the duct may be traced to the floor of the mouth. Its passage
along the floor of the mouth to the papilla may be more readily
traced by removing part or all of the corresponding mandibular
ramus.

§ 784. Glandula sublingualis—Sublingual gland.—The sublin-
gual gland in the cat is quite small and so closely connected to the
submaxillary that it appears as an accessory of it. It is elongated
and extends cephalad from the submaxillary about 2 cm. and par-
allel with Wharton’s duct. Its duct, smaller than that of the sub-
maxillary, extends parallel with it and opens upon the same papilla.

§ 785. Glandula molaris—Molar gland.—This gland is small as
compared with the parotid, but is of the same general appearance.
It is situated near the angle of the mouth about 1 em. ventrad of
Stenon’s duct. It has several ducts which pass straight through
the cheek and open on the mucous surface. This gland is con-
sidered by Cuvier (A, III, 424), Ward, (A, IV, 426), and Quain

MOUTH OR BUCCAL CAVITY. 3803

(A, II, 301), to be merely an aggregation of buccal glands; see
8 794.

§ 786. Glandula zygomatica—Zygomatic, subzygomatic or in-
fraorbital gland.—This is a compact, somewhat elongated gland
situated in the lateral part of the orbit. Its ventral end rests on the
mucous membrane of the roof of the mouth just caudad of the last
maxillary tooth (true molar, see Fig. 57, D. M.), and its duct opens
at the same place.

§ 787. To demonstrate this gland, the mouth may be kept open
byacork between the teeth ; then the mucous membrane just caudad
of the last maxillary tooth should be cut, and the gland will appear.
Or the zygoma, the malar process of the maxilla and the masseter
muscle may be removed to expose the lateral surface of the eye-
ball. The gland will be found at the ventro-lateral surface of tie
eye. To demonstrate its duct, carefully tear away the gland sub-
stance near its ventral end with a tracer.

§ 788. Structure of Salivary Glands.—The obvious structure of the salivary glands
is that of the racemose type, that is, like a bunch of grapes, the ducts representing the
stems and the lobules the fruit.

§ 789. Microscopic Structure—The ducts, except the very smallest, are lined with
columnar epithelium ; the smallest are lined with pavement epithelium. Their mode of
termination “demands further investigation ” (Stricker, A, 800). The lobules are com-
- posed of groups of spheroidal cells surrounded by a continuation of the connective tissue
forming the interlobular septa. Quain, A, II, 339.

CAVUM ORIS, MOUTH OR BUCCAL CAVITY, PHARYNX, az. (Fig. 77, 88).
References. —Quain, A, II, 300; Gray, A, 745; Chauveau, A, 351; Chauveau (Flem-

ing), A, 330; Leyh, A, 364; Owen, A, III, 883; Cuvier, A, III, 379; Hyrtl, A, 241; Ge-
genbaur (Lankester), A, 548; Milne-Edwards, A, VI, 11; Gurlt, A, 336.

§ 790. The mouth cavity or cavum oris is the cephalic division
of the alimentary canal. It is bounded cephalad by the lips and
caudad by the velum palati and the cephalic opening of the pha-
rynx. It contains the teeth, gums, alveolar margins, the jaws, the
tongue and the tonsils, and into it open the ducts of the salivary’
and buccal giands.

§ 791. Pharyna, az.—See description of Fig. 88.

Exposure and Dissection—Fig. 88.—With a scalpel, divide the
skin and soft parts upon both the dorsal and the ventral aspects of
the head 1 em. sinistrad of the meson from the snout to a point
opposite the 2d or 3d cervical vertebra. With the arthrotome, sep-
arate the mandibular rami at the symphysis menti, and with bone

\
3604 ANATOMICAL TECHNOLOGY.

scissors, cut the left pier of the os hyoides (Fig. 30, § 224). Hemisect
the tongue and the muscles along the ventral side, cutting about
1 cm. to the left of the meson and entirely through to the buccal
cavity. The trachea and cesophagus should be displaced to the
right. Cover the hand with a towel and grasp the left side of the
head, and divide the entire head with the saw, commencing at the
snout a little sinistrad of the meson and making the strokes in the
dorso-ventral rather than in the caudo-cephalic direction. With
nippers, remove the left side of the vertebral arch of the atlas, axis
and the sxud/ as far as the meson.

§ 792. Ifa permanent preparation is to be made, the remaining
half of the mandible should be opened and a cork put between the
teeth ; the tongue should be drawn slightly cephalad and held in
position by a pin pushed through its tip and into the floor of the
mouth. The velum palati may be pinned out as in the figure.
Finally, the esophagus and larynx should have one side cut away
for a short distance and the tubular portion distended by filling the
lumen with cotton ; the opening of the Eustachian tube should also
be filled with cotton.

Begin the hardening in about 60 per cent. alcohol (§ 286). After
the head has thoroughly hardened, the brain may be sliced away
to the meson, and the mesethmoideum and vomer removed to show
the turbinated bones and the passage from the prenaris to the post-
naris. The surface, especially of the tongue, may be freed from
mucous with a sot nail brush. .

§ 793. Obcious Structure of the Cavum oris or Mouth—The free surface is usually
quite firm and smooth, except in certain places, as the roof of the mouth, where there are
many ridges and fine projections.

§ 794. Microscopic Structure.—The fre> surface is made up of stratified epithelium rest-
ing on a rather abundant submucous connective tissue, in which are small so called buceal
gands of the racemose type (§ 178), whose ducts open on the frec surface.

: § 795. Obvieus Structure of the Lingua or Tongue.—The free surface on the ventral

side of the tongue is smooth and soft. On the dorsal side it is beset with numerous pro-
jections or papille of various forms, ramed in the order of their abundance :—Filiform,
odontoid, fungiform, cireumcallate.

§ 796. Microscopic Structure—Into all the parpille extend loops of blood vessels.
The odontoid variety are covered by a horny substance. In the walls of the eirewmrallate
are imbedded the so called taste buds, flask-like in form and composed of modified epithe-
lium. The princival mass of the tongue consists of strip:d muscle and connert ve tissue.
The muscles are arrange. in an intricate net-work, the fibers sometimes branching near
the mucous coat. The free or mucous coat consists of stratified epithelium with a small
amount of submucous connective tissue, See Stricker, A, 352; Qaain, A, IT, 827.

HEMISECTION OF THE HEAD. _ 805
Preparation—Fig. 88—See p. 303, exposure and dissection—
Fig. 88.

Explanation of Fig. 88.—Atlas, az,—The first cervical vertebra.

Axis, az—The second cervical vertebra ; its vdontoid process (Fig. 52) is shown pro-
jecting cephalad into the ring of the atlas.

Callosum, Corpus callosum, az.—The great commissure of the hemispheres. (For this
and the other parts of the brain, see Fig. 117.)

Pies Wharton, Larinitt

“i
Fie, 88.—HEMISECTION OF THE Heap; x1. Compare with Fig. 59 and 117 and with
Plate Il, Fig. 4.

ts iets

Cn. (Canalis) Eustachiana.—The canal connecting the middle ear or tympanum with
the pharynx. Its crescentic opening into the pharynx is shown in this figure.

Cn. (Canalis) neuralis, az.—Neural or vertebral canal_—The neural canal is repre-
sented by the deeply shaded space in the vertebrae in which the myeion rests. (The name
is put upon the muscles dorsad of the roof of the arch of the atlas and axis. Through
an inadvertence no dotted line is drawn from it to the canal )

20

306 ANATOMICAL TECHNOLOGY.

Chd. ve., Chorda vocalis.—Vocal cord.

Dien., Diencephalon.—The abbreviation is written in the space between the two
thalami known as the diacelia or “‘ 8d ventricle.”

Dect. Stenon., Ductus Stenonianus—Stenon’s duct, Duct of the parotid gland (Fig.
87, § 780).—Its opening is hidden by the prominent cusp of the last premolar, but a
bristle is represented as coming from it.

Ductus Whartonianus—Wharton’s duct, Duct of the submaxillary gland (§ 783).—
The prominent papilla at the summit of which the duct opens is shown.

Dura—Dura mater.—The dura is represented in this figure as a broad white line just
entad of the cranium and then prolonged into the neural canal as a sheath for the myelon.
It takes the place of the periosteum in the skull, but the neural canal is lined by a special
periosteum, so that the dura in the neural canal belongs exclusively to the myelon.

Epen., Epencephalon, Cerebellum.—See Fig. 117.

Epgit., Epiglottis.—The triangular flap which aids in the closure of the glottis dur-
ing deglutition. ;

Ethtrb., Ethmoturbinale—The ethmoturbinal bone (Fig. 59, § 550).

Falx, Falx cerebri, az—The fold of dura separating the olfactory lobes and part of
the mesal surface of the hemispheres of the right and left sides. In this figure it is
shaded with horizontal lines.

Fren., Frenum linguz.—The more or less plate-like cephalic part of the attachment
of the tongue to the floor of the mouth.

Hy., Hypophysis cerebri, az.—Pituitary body.—See Chap. X.

Inf., Infundibulum, az.—The ventral prolongation of the diaccelia into the hypophysis.

Larynx, az.—The specialized cephalic part of the trachea, containing the vocal cords.

Lingua, az.—Tongue.

Meatus ventralis.—The ventral and more direct passage from the prenaris through
the nasal chamber to the Postnaris or opening into the pharynx.

Mcs., Medicommissura.—Middle commissure (Fig. 117).
Mesen., Mesencephalon.—Optic lobes.

Meten., Metencephalon, az.—Medulla oblongata.
Mxtrb., Maxilloturbinale.—Maxilloturbinal bone (Fig. 59).
Myelon, az.—Spinal cord (Fig. 104).

N. op., N. opticus.—Optic nerve.

CGs., Esophagus, az.—Gullet (§ 801).

O. boc., O. basioccipitale, az. (Fig. 59).

O. bsph., O. basisphenoideum, az, (Fig. 59).

O. presph., O. presphenoideum. az. (Fig. 59).

. hyoides (Fig. 30, § 224).

. plt., O. palatinum (Fig. 59).

. mx., O. maxillare (Fig. 59).

. pmx., O. premaxillare (Fig. 56).

. soc., O. supraoccipitale, az. (Fig. 59).

. ip., O. interparietale, az. (Fig. 59).

- parietale (Fig. 56).

O. frontis (Fig. 56).

O. nasale (Fig. 56, 59).

Papille filiformes—Filiform papilla (§ 795)—These are the fine projections from the
dorsal surface of the tongue. Caudally they become broad and ligulate (1-3 mm. long),
while in the middle of the cephalic part of the dorsal surface they are modified into the
form next described (Stricker, A, 356).

oo0o0000

THE NECK. 307

Ppl. (Papille) odontoides (Milne-Edwards, A, VI, 104).—These are the horny re-
curved papille on the dorsal aspect of the cat’s tongue with which it rasps the surface of
bones. For the other papille, see Quain, II, 325.

Ppl. fng., Papille fungiformes—Fungiform papille.—These are the bead-like projec-
tions on the dorsal surface of the tongue. They are especially abundant near the middle
of its length.

Ppl. erem., Papille circumvallate—Circumvallate papille.—These are few in num-
ber and are situated on the dorsal surface of the tongue in the locality indicated in
Fig. 88. They appear like large fungiform papille with a trench and a raised border
around them.

Pharynx, az.—The general cavity into which open the mouth, postnares, Eustachian
tube, cesophagus and trachea.

Pili tactiles—Tactile hairs (Fig. 87).

Prznares—Nostrils.—The opening of the nasal chamber at the snout.

Rhinen., Rhinencephalon.—Olfactory lobes.

Rugz.—The transverse wrinkles or folds in the roo* of the mouth. There are five or
six of these, and they are covered with short, stiff papille.

S. sph., Sinus sphenoideum,—Sphenoidal sinus (Fig. 59).

Symph. (Symphysis) menti, az.—The amphiarthrodial articulation between the two
sides of the mandible.

Tnt., Tentorium cerebelli.—The letters are on the bony tentorium (see Fig. 59), but
this is seen to be lined on its ental surface by the dura. The dura is as easily separable
from the bony tentorium as from the other parts of the skull, and the bony tentorium itself
seems to be a part of the Os parietale, not an ossification of the membranous tentorium as
stated by Flower, A, 99 ; see Cuvier, A, III, Article 10.

Trachea, az.—Windpipe.—The tube connecting the lungs with the pharynx (Fig. 77).

V1. plt., Velum palati, az—The pendulous or caudal portion of the soft palate. It is
here represented as lifted from the tongue so that it extends nearly caudad instead of
curving ventrad as in nature.

Vibrisse— W hiskers.—See Fig. 87, 88. In Fig. 88 their free ends are cut off.

§ 797. Collum, az.—Neck.—This is the constricted portion of
the trunk cephalad of the first rib, ¢. e., between the thorax and
head (Fig. 6).

§ 798. Haposwre——Make an incision along the neck about 2 cm.
to the right of the ventrimeson as far caudad as the first rib; then a
transverse incision just cephalad of the first rib to a point 2 cm. to
the left of the ventrimeson ; dissect off the skin and the muscles
covering the trachea (Fig. 76).

§ 799. Trachea, az.—Windpipe (Fig. 77)—The trachea cannot
be mistaken, as it is the first tube uncovered by the removal of the
skin and muscles on the ventral aspect of the neck.

Cut out a segment of the trachea 3-4 cm. long. It will be seen
to be a cylindrical tube stiffened by rings of cartilage which do
not meet on the dorsal side, excepting when the trachea is con-

308 ANATOMICAL TECHNOLOGY.

tracted. When uncontracted, the dorsal side is fleshy, something
like the cesophagus.

§ 800. Microscopic Structure of the Trachea.—(A) Its ectal layer is of rather dense
connective tissue. In it are imbedded the incomplete rings of cartilage. (B) Entad of the
connective tissue layer and extending around about the dorsal third of the circumference
of the trachea is a layer of unstriped musele. This is partly attached to the ectal surface
of the rings of cartilage, and by its contraction causes the rings to meet or even overlap.
(C) Entad of (A) and (B) is a layer mostly composed of elastic connective tissue. (D) Mu-
cous membrane. This lines the lumen of the trachea. It is composed of three layers of
cells, the free layer of which is ciliated. (E) Imbedded in the wall of the trachea are
many racemose glands whose ducts open on the free surface of the mucous membrane. See
Stricker, A, 485; Quain, A, IT, 266.

§ 801. Gsophagus, az.—Gullet (Fig. 77, 109).—The cesophagus
is the fleshy tube connecting the pharynx and stomach.

§ 802. Demonstration.—Draw the trachea somewhat dextrad,
and there will be seen the cesophagus, an entirely fleshy tube, dor-
sad and slightly to the left of the trachea. When empty it does
not retain a cylindrical form like the trachea, but collapses.

§ 803. Structure of the Gfsophagus—{A) The ectal layer is composed of striated mus-
cular fibers arranged as in the intestine (§ 741), with an admixture of wnstriated muscle
increasing caudad. (B) The intermediate layer is of connective tissue and forms the sub-
mucosa. It contains many small racemose glands. (C) The ental or mucous layer is
composed of stratified epithelium. See Stricker, A, 361 ; Quain, A, I, 344,

THORAX.

§ 804. The thorax or chest is the part of the trunk between the
diaphragm and first rib. Its cavity contains the lungs (§ 809), the
heart and great vessels (Fig. 91), and part of the trachea and
cesophagus (§§ 799, 801; see also Chap. VIII).

§ 805. Exposure.—Determine the position of the following land-
marks: presternum (§ 228); xiphisternum (§ 228); first rib (Fig.
30, 72); ventrimeson—the line between the xiphisternum and pre-
sternum.

Incisions.—A. Make a longitudinal incision (§ 599) through the
skin and muscles 3 cm. to the right of the ventrimeson from the first
rib to a point opposite the base of the xiphisternum. Taking care
not to injure the vessels and nerves in the axillary region, reflect
the skin for 2-3 cm. on the right of the incision.

B. Make a transverse incision from the caudal end of the longi-
tudinal incision to a point 4-5 cm. to the left of the ventrimeson.

semen

THE PLEURA. 309

Reflect the skin across the ventrimeson as far as the transverse
incision extends. Scrape or dissect the muscles from the ectal sur-
face of the ribs and cartilages near their union ; see Fig. 50.

C. With the arthrotome or strong scissors, cut through the tho-
racic wall on both sides, just mesad of the junction of the cartilages
and ribs.

§ 806. Pleura, Septum mediastinale.—Grasp the cut edges of
the right costicartilages and turn the sternum partly to the left side.
The ental surface of the thoracic wall is covered by a smooth glis-
tening membrane, the plewra, a serous membrane like the perito-
neum (§ 725); like the latter, it may be detached over a small space
by means of the tracer.

At the meson will be seen a transparent curtain containing
blood vessels and more or less fat. This is the mediastinwm, me-
diastinal septum or septum thoracis (Fig. 7, 99, 100). It divides
the thorax into a right and left half. Each half of the thorax is
lined by a separate serous sac, and the meeting of these on the
meson produces the mediastinal septum. The thorax thus differs
markedly from the abdomen, where there is but one serous sac
(§ 725), but the thoracic organs, like those of the abdomen, are all
properly ectad of or owtside the serous membrane. Some of the
organs, as the heart, are between the two walls of the septum, while
others, as the lungs, are apparently within the sacs, as the alimen-
tary canal is within the peritoneal sac (see Fig. 78).

§ 807. After the mediastinal septum has been examined, make,
with bone scissors, a transverse incision from the right to the left
between the incisions in the thoracic wall, cutting the soft parts in
the intercostal space between the 9th and 10th ribs. Then cut the
mediastinum near its attachment to the sternum to a point opposite
the 4th costal cartilage, avoiding injury to the blood vessels.
Finally, turn the sternum cephalad and secure it in this position
with a string or a pin.

With the nippers, cut the ribs, excepting the first, on each side
along a line about 3 cm. from their tubercula, and with scissors or
a scalpel, cut the soft parts and remove the freed portion of the
thoracic wall.

§ 808. Thymus gland.—If the bat is young, there will be seen
an elongated pinkish “body (Fig. 77) extending along the ventral
side of the trachea and great vessels from the heart to a point some-
what cephalad of the first rib. . This is one of the so called ductless

310 ANATOMICAL TECHNOLOGY.

glands ; it is also a temporary organ and may be entirely absent in
old animals. Its function is not well understood.

References to the Lungs.—Quain, A, II, 269; Gray, A, 827; Chauveau, A, 498;
Chauveau (Fleming), A, 466; Leyh, A, 444; Owen, A, III, 572; Cuvier, A, VII, 19;
Hyrtl, A, 306 ; Gegenbaur, A, 572; Milne-Edwards, A, II, 384; Williams (T.), A, V, 258.

§ 809. Pulmo — Lung (Fig.
77, 89, 99, 100).—On each side
of the thorax, extending from
the diaphragm to the first rib,
will be seen a sponge-like mass.
Each of these masses is a lung;
and the two are the essential or-
gans of respiration. Insert a
glass tube or a flexible blow-pipe
into the trachea and inflate the
lung. The trachea must be
pressed closely against the tube
to prevent the escape of air.

§ 810. Lobes.—Each half of
the inflated lung will be seen to
consist of several divisions, the so
called lobes. There are three on
each side—cephalic, intermediate
or middle, and caudal (Fig. 89).

_Azygous Lobe.— The right
lung, in addition to the three
lobes mentioned in the preceding
paragraph, has a small one, the
azygous lobe, projecting into a
kind of pocket formed of pleura,
aS ep Peageers fo. dorso-caudad of the apex of the

(‘The apparatus is arranged as for an heart and between it and the dia-

experiment ; see Wilder, 23.) phragm (Fig. 77, 103, C.1., az.).

The free edge of this pocket is
bounded by the postcava. This lobe is sometimes deeply divided
into two, the caudal of which is the larger.

§ 811. Air cells—Hold an edge of the inflated lung between the
eye and the light, and note that it is divided into spaces about 1 mm.
in diameter. These are the air cells. See Structure, §§ 813, 814.

THE DIAPHRAGM. 311

§ 812. Bronchi and Bronchioli.—The trachea should be fol-
lowed from the neck into the thorax, cutting or tearing away any
blood vessels or nerves that cover its ventral suriace, and also the
thymus (Fig. 77, § 808). Near the intermediate lobe of the lung,
the trachea divides into the two bronchial tubes, one of which goes
to each lung. Tear away the substance of the lung sufficiently to
follow one bronchus. It will be seen to continually divide and so
form the dronchioli.

§ 813. Obvious Structure of a Lung.—On entering the lung the bronchus divides like
a tree into branches (bronchioli). Near their termination the bronchioli dilate somewhat,
thus forming the so called infundibula or ultimate lobules, From the wall of the infun-
dibulum project sac-like recesses singly or in groups. Each recess is called an alveolus,
and may be considered as the blind ampulliform termination of the smallest division of an
air tube. The alveoli may be readily seen by looking at the edge of an inflated lung as
directed above (§ 811).

§ 814. Microscopie Structure—This is very complicated, its main features being as fol-
lows :—(A) The air tubes are composed of an ectal dense, largely elastic, connective tissue
layer, in which are found plates of cartilage. (B) Unstriated muscular layer. (C) An
elastic connective tissue layer. (D) The mucous membrane with its ciliated epithelium.

In the smallest air tubes the cartilage disappears. In the larger ones are small race-
mose glands asin the trachea. As an air tube enters a lobule, its ciliated epithelium is
supplanted by a stratum of cubical, non-ciliated cells. The unstriped muscle also disap-
pears, and finally the alveoli are lined with a single layer of pavement or scaly epithelium.
See Stricker, A, 487; Quain, A, II, 273.

DIAPHRAGMA, az.—DIAPHRAGM.

References.—Straus-Durckheim, A, II, 309; Quain, A, I, 308; Gray, A, 394; Milne-
Edwards, II, 406 ; Chauveau (Fleming), A, 245; Chauveau, A, 260; Gegenbaur (Lankes-
ter), A, 574; Hyrtl, A, 316; Cuvier, A, VII, 198 ; Owen, A, III, 1.

§ 815. The Diaphragm (Fig. 77, 90) is a musculo-tendinous cur-
tain completely separating the thoracic and abdominal cavities.
Many structures transverse it, but they are joined to their respective
apertures in such a manner that the partition is absolutely air-tight,
and yet no hindrance is put upon the free movement of the dia-
phragm in respiration.

The tendinous part (Fig. 90) is near the middle. Its form is
somewhat crescent shaped, the horns of the crescent pointing dor-
sad. From the tendon radiate the muscular fibers. Those of the
dorso-mesal third converge and form two thickened masses called
the crura or pillars of the diaphragm.

The diaphragm is attached to the ziphisternwm, to the last five
ribs, and somewhat loosely to the thick muscles which lie ventrad
of the vertebre. The crwra unite, forming a single dense tendon,

312 ANATOMICAL TECHNOLOGY.

which is attached to the centra of the 2d, 3d and 4th lumbar ver-
lebre.

It will be seen from the above that the diaphragm is attached
very obliquely to the body wall so that the dorsal part is caudad
of the ventral. The central part is strongly arched into the thoracic
cavity.

§ 816. Posture and Preparation.—The cat should be placed in
a dorsicumbent posture, the abdomen opened as directed for the
study of the viscera ($§ 237, 710), and injected from the abdominal
aorta and postcava (§§ 363, 365). The abdominal wall should be
cut along a line about 2 cm. caudad of the diaphragm. The liver
and stomach should be drawn somewhat caudad ; the suspensory
ligament, the postcava and the esophagus cut, the two last named
about 2 cm. from the diaphragm. Care should be taken not to
cut the diaphragm in any of the operations.

The kidneys (Fig. 101) should be removed, and the aorta about
2 cm. caudad of the origin of the swperior mesentery artery. The
vertebral column should be disarticulated between the 4th and 5th
lumbar vertebre (Fig. 30). The superior mesenteric artery and the
celiac artery and the splanchnic nerve (Fig. 103, 107, A. c., N.
splnch.), should be carefully isolated with the tracer, fine forceps
and fine scissors. It is also desirable to isolate the vagus (gastric
nerves) on the cesophagus (see Fig. 103, 107, N. g.d. N. g.v.). The
ribs should be cut near their tubercula, and then the ventral border
of the diaphragm drawn strongly cephalad and held in position with
large pins. Lastly, the fat and connective tissue should be removed
from the muscles so as to show the direction of the diaphragmatic
fibers and their interdigitations with those of the JZ. transversalis.

Preparation—Fig. 90.—The thoracic duct (Fig. 103), the abdom-
inal aorta and postcava (Fig. 101) were injected. The cat was then
transected, following a line about 1 cm. caudad of the tip of the
xiphisternum and going between the 4th and 5th lumbar vertebre.
The ventral border of the diaphragm was drawn strongly cephalad
and cotton placed on the pleural side to make it nearly level.

Explanation of Fig. 90.—Aorta, az.

A. phrn., A. phrenica.—The phrenic or diaphragmatic artery.

A. adrn, Imb., A. adreno-lumbalis.—The adreno-lumbar artery, a small artery aris-
ing from the aorta and supplying the adrenal body and the cephalic part.of the lumbar
region,

C., A. celiaca, az.—The cceliac artery or coeliac axis.

THE DIAPHRAGM. Sls

Crus dphrg., Crus diaphragmatica.—The left crus or pillar of the diaphragm.

Det. thr., Ductus thoracicus, az.—The left thoracic duct (Fig. 103).

Gng. (Ganglion) semilunare.—The semilunar ganglion—Ganglion of the solar plexus
of nerves (Fig. 107).

M., A. mesenterica superior, az. (Fig. 103, 107).

Fig. 90.—CAUDAL VIEW OF THE DIAPHRAGM WITH THE STRUCTURES THAT TRAVERSE
IT; x 75.

Mbrn., Membrana.—The somewhat crescent-shaped membranes which, with the
muscular portion of the diaphragm, complete it dorsad. It is said by Straus-Durckheim,
A, Il, 310, that, in place of these membranes, there are often muscular pillars—lateral
pillars of the diaphrazm—joining the diapophyses of the 2d lumbar vertebre.

M. transversalis-abdominis.

M. gq. lumb., M. quadratus lumborum.

M. psoas. (The human psoas magnus.)

314 ANATOMICAL TECHNOLOGY.

NN. sym., NN, sympathici.—The sympathic nerves of the two sides continued into
the abdomen.

NN. spinch., NN. splanchnici.—The two splanchnic nerves of each side joining the
corresponding semilunar ganglion (Fig. 107, Gng. smIn.),

N. gastricus—Gastric nerve.—There are two of these, one on the dorsal and one on
the ventral side of the esophagus (Fig. 107, N. gstr. dor., N. gstr. vnt.). They are the
continuations of the vagus nerves into the abdomen.

CEs., Csophagus, az.—This is somewhat loosely attached to the diaphragm, ard
hence can move longitudinally quite freely (Fig. 107, C&s.).

Pcv., Postcava, az.—The great vein returning blood to the heart from the caudal
half of the body (Fig. 101).

Tendo centralis, az.—The central tendon of the diaphragm.

Tendo, az.—The common tendon of the two crura of the diaphragm. It is very
strong and firmly attached to the 2d, 3d and 4th lumbar vertebre.

VV. phrn., Venez phrenice.—The phrenic veins. The large trunks follow mostly
the two horns of the tendo centralis.

VV. hepat., Venz hepaticz, az.—Two hepatic veius from the right lobe of the liver.
They unite just as they enter the vena cava (Fig. 101).

Xiphisternum, az.

CHAPTER VIIL
THE VASCULAR SYSTEM.

GENERAL CONSIDERATIONS — HEART—ARTERIES—CAPILLARIES— VEINS — LYMPHATICS—
THORACIC DUCTS.

§ 817. General Considerations.—In the cat, as in man and the
higher animals generally, the tissues are supplied with blood, and
blood and lymph are removed from the tissues, by means of a series
of closed tubes or vessels. These tubes all communicate more or
less directly with one another, but—excepting the lymphatic stom-
ata—present no obvious openings into any other parts. This closed
series of tubes is known as the vascular system.

The vascular system as a whole consists of two main divisions,—
the blood vascular system and the lymph vascular system or
lymphatic system.

§ 818. The blood vascular system is that by which the blood is (A) conveyed to the
tissues in general for their nourishment and returned therefrom ; (B) conveyed to the
lungs for its own improvement and returned therefrom (Fig. 92). Those parts which are
concerned in the transfer to and from the lungs constitute the pulmonic division of the
blood vascular system, and the remainder constitute the general or systemic division.
While in process of transfer, the blood is said to perform either the pulmonic or the
systemic circu/ation.

§ 819. Subdivisions of the Blood Vascular System.—There are four parts, continuous
with each other, but more or less distinctly differentiated : (A) A central receiving and
distributing organ, the heart (cardia) ; (B) tubes extending from the heart throughout the
lungs and the organs generally, the arteries ; these divide and diminish in size like the
branclies of a tree, and gradually merge into (C) the capillaries, the most minute vessels,
which in turn unite and gradually merge into (D) the veins, which unite and increase in
size as they diminish in number and finally terminate in the heart (Fig. 92).

The arteries are said to continually divide and decrease in size because the current
therein is from the larger vessels toward the smaller. The veins are said to unite and
increase in size because the blood current is from the smaller to the larger branches.
Again, the arteries are said to extend from the heart peripherad, that is, in the direction of
their blood current, while the veins are said to extend toward the heart or centrad, as the
current is toward the central organ. The veins differ from the arteries by having thinner
walls and by the presence of valves in many (Fig. 102, B, C).

316 ANATOMICAL TECHNOLOGY.

§ 820. The Lymph Vascular System.—This is that part of the general vascular sys-
tem which collects the /ymph from the tissues and the chyle from the alimentary canal
and conveys them to the great veins ; it is thus an auxiliary of the venous system (Bernard,
A, 250). From the office of collecting both lymph and chyle, it is commonly considered
as forming two divisions: (A) The lymphatics proper ; (B) the lacteals or chyle vessels.

§ 821. The lymphatic system is somewhat comparable to the venous, since its vessels
begin as capillaries at the periphery and extend toward thecenter, Like the veins also, the
lymphatic vessels contain numerous valves which prevent a reversal of the current, that is,
a flow from the center tcward the periphery.

The lymphatic vessels differ from the veins in the following particulars: (A) They
have thinner walls ; (B) they do not so markedly increase in size as the veins, although
they anastomose more frequently; (C) at various points along their course there are
enlargements, the so called lymphatic glands, through which the lymph passes; (D) in-
stead of joining the central organ of the vascular system directly as do the blood vessels,
the lymphatic trunks open into veins (Fig. 103); (E) the lymphatic system differs from
the venous also in having no direct communication through capillaries with anything like
an arterial system; (F) the lymphatics are found to communicate with serous cavities
through minute orifices, the stomata (Quain, A, I, 188 ; Stricker, A, 222).

CARDIA—THE HEART,

§ 822. References.—Quain, A, IJ, 242; Gray, A, 801; Cuvier, A, VI, 272; Gegenbaur
(Lankester), A, 583; Hyrtl, A, 800; Bernard, A, 274; Milne-Edwards, A, III, 473; Owen,
A, Ill, 516; Chauveau, A, 529; Chauveau (Fleming), A, 499; Gurlt, A, 574; Straus-
Durckheim, B, II, 181 ; Foster and Langley, A, 91; Smith, E. N., A, Pl. 47, 48, 49, 55, 56;
Bourgery and Jacob, A, Pl. 9, bis, Pl. 13 ; Rolleston, B, 25-384; McAlpine, B, I, Pl. 23;
Krause, A, 178, Fig. 13; Turner, A, 899 ; Sabatier, A; Flower, A; Pettigrew, 64; Petti-
grew, A; Parchappe, A ; Mojsisovics, A, 54; Leyh, A, 559; Mivart, B, 199-206.

Remark.—Most of the above refer to the human heart more especially, but the heart
of the horse is chiefly described by Leyh, Chauveau and Gurlt, and that of the rabbit by
Krause, McAlpine and Foster and Langley. Methods of preparation are given by Hyrtl,
Straus-Durckheim, Mojsisovics and Pettigrew. The only descriptions and figures purport-
ing to refer to the -heart of the cat are given by Mivart ; unfortunately, however, in Fig.
102, the relative thickness of the right and left ventricles is made the reverse of what it
should be (a probable oversight which, although readily corrected by the anatomist, is
sure to confuse the beginner); while the usefulness of the text is diminished both by the
general uncertainty as to how much refers directly to the cat (§ 127), and by the presence
of an absolute misstatement upon pp. 201, 214 respecting the number of pulmonary veins.

§ 828. Before dissecting the heart, or even removing it from the body, the student will
do well to familiarize himself with its general features and location as shown in Fig. 77,
91, 101. ;

If he has been following the present work in order, he will have at least one cephalic
region of a cat preserved in alcohol, and may run the risk of injuring the heart thereof in
removing it before gaining any detailed knowledge of it. He must bear in mind, how-
ever, that all the cavities of such a heart will be collapsed and that the auricles especially
will look very unlike the preparation shown in Fig. 91. Such a heart may serve for the
examination of some parts, but eventually he should have at least two specimens well dis-
tended and hardened by alcohol, and if possible another filled with plaster.

§ 824. Preparation—Fig. 91.—The postcava and abdominal aorta

THE HEART. 317

were injected with red and blue plaster respectively. After the plas-
ter had hardened, a small hole was made in the left ventricle and a
long canula inserted and pushed through the awriculo-ventricular
opening into the left auricle. Red plaster was then injected so as
to fill the pulmonary veins. Finally, the pericardium was removed
together with the fat and connective tissue covering the cardiac
vessels.

$ 825. Deseription—This, the dorsal or “‘ posterior ” aspect of the heart, is less famil-
iar to most persons and less frequently represented. It is, however, much more compre-
hensive and instructive than the ventral aspect,
and is given in the following works : Quain, A,
Il, Fig. 166; Smith, E. N., A, Pl. 55; McAl-
pine, B, Pl. XXIII, Fig. 3 (rabbit) ; Gegenbaur
(Lankester), A, Fig. 336 (pig).

The present figure fairly represents the size
of a somewhat large heart, and its form when
injected. As stated, however, in § 829, it is
probable that the less thickness of the lateral
wall of the right ventricle has permitted it to
yield to the force of the injection so that the
right side is unduly convex.

The word ventriculé is written across the
apex of the ventricular portion, and the abbre-
viation V. erd. is just below the furrow between
that and the auricular portion.

For the sake of showing certain parts more
distinctly, the figure represents the organ as if
rotated slightly upon its longer axis so as to ex-
pose more of the right than of the left side.
The line of demarcation between the right and
left auricles (Aur. dat., Aur. sin.) coincides
nearly with a line connecting the V. of V. crd.
with the left border of the precava. The ductus
arteriosus (§ 867) is not shown.

§ 826. General Description of the Heart.— Fie. 91.—Tae Dorsat ASPECT OF THE

The heart is a hollow, quadrilocular (four cham- HEART WITH TITE CENTRAL Por-
bered) muscular organ situated in the thorax. TIONS OF THE LARGER VESSELS;
It is the anatomical and physiological center of from a Maltese cat; x1.

the vascular system, simultaneously receiving
blood from the lungs and from all other parts of the body, and distributing it thereto.

§ 827. Location—As seen in Fig. 77, 99, 101, the heart is on the meson, but extends
a little farther to the left than to the right. In Fig. 101 it appears at a considerable dis-
tance from the diaphragm, but of the latter only the dorsal portion remains, and its
cephalic convexity is réally very close to or in contact with the heart.

§ 828. Pericardium.—The heart proper is enveloped in a fibro-membraneous sac, tlie
pericardium, which is attached about the roots of the great vessels, but elsewhere is uncon-
nected with the heart, which thus moves freely within it. The pericardium is best studied

318 ANATOMICAL TECHNOLOGY.

by girdling it at about the middle of the length of the organ and reflecting the attached
end over the great vessels so as to display the line of attachment. Its relations to both
the heart and the diaphragm will be mentioned in the descriptions of Fig. 99, 100.

§ 829. Horm.—When moderately distended, the heart is approximately oval in shape,
one end obtuse and the other pointed.

As seen in Fig. 92, however, this oval is not regular, one side being more curved than
the other. This is due to the greater yielding of the thinner wall of the right ventricle
to the pressure of the injection. As a whole also, the organ is slightly flattened in what
will be found to be the dorso-ventral direction; this may be due to the greater resistance
offered by the septum ventriculare to the pressure of the injection.

§ 830. Normal Position.—Naturally, the longer axis of the heart is oblique with
respect to the meson. The smaller end points caudo-sinistro-ventrad. For purposes of
description, however, it will be more convenient to assume that the two ends of the organ
point respectively cephalad and caudad.

The obliquity in position of the cat’s heart is probably less than that of man (as re-
marked by Owen, A, III, 525), but it is nevertheless decided. In frozen section No. 11 of
the series from which Fig. 99 and 100 were made, the apex of the heart is at least 15 mm.
sinistrad of the meson.

§ 831. Size.—Fig. 91 represents the natural size of the preparation from which it was
made, but the heart was from a large cat, and was somewhat distended with plaster by
injection. In round numbers, the heart of an average adult cat measures about 5 cm.
from the apex to the attachment of the precava and about 3 cm. across the greatest width
of the ventricular portion. We have not yet ascertained the average weight of the organ,
but it is very considerable in comparison with the size and weight of the animal.

§ 832. Designation of the Regions.—As shown in Fig. 92, 93, the cephalic and caudal
ends of the heart differ not only in shape, but in the thickness of the muscular walls.
Since the two cavities enclosed by the thinner cephalic walls are known as awricles, the
cephalic or basal region or end of the organ is spoken of as auricular ; in like manner, the
other end or region is called ventricuzar from the name of the two cavities enclosed by the
thicker wails.

As seen in Fig. 95, 96, there is a partition between the auricles and another between
the ventricles. These septa divide the organ into two sides or portions like the sides of a
double house. Since the planes of the septa are approximately dorso-ventral, it is custom-
ary to speak of the two sides as right and /eft. The other two surfaces and regions are
then respectively dorsal and ventral.

§ 833. Recognition of the Regions.—The cephalic and caudal regions are readily distin-
guished both from the greater size of the former, from the more compressible nature of
the walls, and from the presence of the vessels which enter or leave the organ. In the
natural attitude of man, the base of the heart is uppermost, but this somewhat puzzling
feature does not appear when the animal is regarded as in the normal position of a verte-
" brate (§ 35).

The ventral aspect of the heart is comparatively regular, the two auricular appendices
(Fig. 95) projecting slightly at the sides of the two great arteries, aorta and A. pulmonalis.
The dorsal aspect, on the contrary, is quite irregular in the auricular portion on account
of the branching of the two arteries just named, and the entry of veins into the auricles
(Fig. 91).

The right and left sides are of course determined by the determination of the ends and
the other two sides. In addition, the wall of the right ventricle is decidedly thinner than
that of the left, and that region is therefore the more compressible.

REMOVAL OF THE HEART. 319

§ 834. Removal of the Heart.—For obvious reasons, a cat’s
heart intended for careful examination should be taken from a
large adult. In most cases the same cat may be employed for the
removal of the drain and for the separate study of the abdominal
viscera (Chap. VII). Unless the vessels are to be filled with plas-
ter, it is better not to bleed the animal, since the presence of the
blood in the large veins near the heart facilitates their recognition.

Instruments and Materials.—Arthrotome ; tracer ; medium scalpel; coarse scissors ;
bone scissors ; nippers ; coarse and fine forceps; 6 pieces of linen thread about 20 cm. long ;
2 pieces of thick muslin or flannel or chamois leather, each about 15 x7 cm. ; basin of
water and towel ; large tray, with cords for securing the legs of the cat.

Landmarks.—Presternum, xiphisternum and epigastrium (§ 228, Fig. 30, 49, 72, 76) ;
clavicle (§ 230, Fig. 30, 72). Observe also the general location of the thoracic viscera in
Fig. 77 and 101 and the operations for their exposure ($$ 710, 805).

§ 835. Hazposwre.—Divide the skin (§ 599) as directed for the
exposure of the thoracic viscera (§ 805), but—unless the lungs are
to be employed for study or experiment—begin the longitudinal
incision (Fig. 76) dextrad of the presternum instead of the larynx.
It is also more convenient to make a second transverse incision from
the cephalic end of the longitudinal one to or beyond the corre-
sponding point upon the left side. :

The triangular or quadrangular area of skin so indicated is to be
raised as directed in § 600 and reflected sinistrad. Divide the pec-
toral muscles (Fig. 72) on the right by a longitudinal incision par-
allel with the edge of the skin, taking care not to cut upon the
clavicle. Grasp the pectoral mass and dissect it up from the proper
thoracic wall to the meson. Repeat the operation upon the other
side and then remove both masses from their attachments to the
sternum. Divide each M. rectus thoracis (Fig. 72, '73) at the caudal
transverse cut edge of skin and dissect them up cephalad.

Through the ZW. intercostales on each side near the middle of
the exposed area, push the conjoined tips of the coarse forceps, and
forcibly separate the blades for about 2 mm. This will permit air
to enter the thorax, and the lungs will collapse so as to be in less
danger of injury during the subsequent operation.

With the arthrotome or bone scissors, divide the exposed costi-
cartilages close to their junctions with the ribs. Cut across the
sternum just cephalad of the xiphisternum, sever the septum medi-
astinale and other adhesions to the ental surface of the sternum,
and reflect it cephalad with the costicartilages or remove it alto-
gether.

320 ANATOMICAL TECHNOLOGY.

Push the lungs on both sides toward the dorsal part of the cav-
ity and with the bone scissors, or nippers and bone scissors, remove
the sternal ends of all the exposed ribs for 2-3 cm., so as to facili-
tate access to the viscera.

§ 836. Removal.—Lift the heart slightly by the pericardium and
sever its pleural attachments to the diaphragm as far dorsad as the
postcava (Fig. 101). Put two ligatures upon the postcava, the cau-
dal one about 2 cm. from the diaphragm if the abdominal vessels
are to be injected. In passing the ligatures about the vessel with
the fine forceps, avoid injuring the azygows lobe of the left lung.
This ligature should not be tied very hard.

Double ligature (Fig. 41) the precava near its bifurcation, and
divide this and the postcava between the two ligatures.

If the lungs are to be studied or experimented upon, place the
cloth or chamois over the cut edges of the thoracic parietes so as to
protect the lungs from laceration by the sharp ends of the ribs.

Grasp the apex of the heart and draw it ventro-cephalad. This
will expose the caudal and azygous lobes of the lungs (see Fig. 89),
the thoracic aorta and esophagus. Insert the fingers dorsad of the
lungs, lift them and sever their attachments as far cephalad as the
central end of the azygous vein (Fig. 101). Double ligature this
vein just centrad of the point of junction of the cephalic branch.
Employ the tracer in isolating the vein so as not to injure other
parts. Then divide between the ligatures.

Cut the aorta opposite the head of the 8th rib, and note that,
usually, some blood remains therein. Grasp its central part and
draw it ventro-cephalad, cutting the intercostal arteries and other
connections as far as the origin of the A. subclavia (Fig. 101, 102).
Then grasp the heart and lungs together, draw them ventrad and
divide the trachea and the vessels cephalad of the heart at the de-
sired points, and the organs may be removed from the thorax.

§ 837. Separation of the Heart from the Lungs.—On the dorsal
aspect, at the bifurcation of the trachea, is a mass of connective tis-
sue and fat enveloping a dark glandular body. Remove these with
the tracer and fingers so as to open a way ventro-cephalad to the
ventral side of the bifurcation. With the tracer, expose the bron-
chus on each side, and note that, on its ventral side, the lung is con-
nected with the heart by a group of vessels, the AA. ef VV. pul-
monales. Ligate very firmly the roots of the lungs and divide them

PRESERVATION OF THE HEART IN ALCOHOL. 321

peripherad of the ligatures, and thus complete the separation of the
heart from the lungs.

§ 838. Preservation of the Heart in Alcohol.—For the study
of the cardiac cavities, the heart should not only be hardened in
alcohol, but distended therewith.

Instruments and Materials.—Coarse scissors ; coarse forceps ; sharp tracer or syringo-
tome ; four threads for ligatures, or two threads and two small compressors; syringe with
canula adapted to the aorta and postcava (a rubber bulb syringe is most convenient in some
respects) ; small jar or glass box ; 95 per cent. alcohol, about 250 cc. ; cotton; small pins;
thread.

At the the time of first preparing a heart by the injection of strong alcohol into the
cavities, we were unaware that it was recommended by Hyrtl and Mojsisovics (A, 58).
The former ascribes (A, 305) the original idea to Wm. Hunter.

§ 839. Removal of the Pericardiwm.—In most cases this should
be partly removed. Pinch it up at a point about one third of the
distance from the base of the ventricles to the apex and make a
transverse incision. Continue this incision around the heart so as
to remove the apical two thirds of the pericardium. It may be pre-
served for reference.

§ 840. Removal of the Blood.—The little blood that may remain
in the left side of the heart can be easily expelled through the aorta.
The right cavities usually contain considerable blood. Remove the
ligatures upon the postcava by carefully pushing entad of it the
point of the sharp tracer or the syringotome. If it has been tied very
tightly, it may be necessary to cut off the end of the vessel.

Introduce the nozzle of the syringe into the postcava and inject
water carefully ; then manipulate the right auricle and ventricle at
the same time so as to expel the blood through the postcava.

§ 841. Tying the Vessels.—Tie firmly the A. brachio-cephalica
and the A. subclavia sinistra at about 1 cm. from their respective
origins from the arcus aorticus (Fig. 102). The other vessels should
have been tied in removing the heart, and the aorta and postcava
are left open for the injection.

§ 842. Injection of Alcohol.—A. Into the left side.—Insert the
canula into the aorta so that the ligature about its tip may be just
centrad of the emergence of the first intercostal artery. Tie it in
place, and prepare a second ligature for tying it after the injection.

Naturally, the progress of the alcohol is checked by the semi-
lunar and bicuspid valves, but it may be caused to pass them by
holding the heart with the apex up, and manipulating the base of
the aorta and the base of the left ventricle. When the auricle and

21

322

ANATOMICAL TECHNOLOGY.

the VV. pulmonales are fully distended, apply the ligature firmly

and remove the canula.

B. Into the right side. —In like manner inject through the post-
cava, but no special manipulation is needed for the liquid to fill
the ventricle and the A. pulmonalis.

§ 843. Hardening.—The heart may be carefully laid in strong
alcohol upon cotton, with the base uppermost, or it may be suspended
by a thread passed about a small pin pushed transversely through

the extreme apex so as not to penetrate the ventricles.

After two

days’ insertion it will be fit for section or dissection.
Injection with plaster.—See explanation of Fig. 91.

§ 844. TABLE OF THE PRINCIPAL PARTS AND FEATURES OF THE HEART (CARDIA).

Hemicarpia SrvistRa (LEFT oR
Systemic PoRTION).

HEMICARDIA DEXTRA (RIGHT OR
ONIC PORTION).

Special Names.

General Names.

Special Names.

Auricula sinistra. ... ......
Ventriculus sinister.........

Orificium aur. -vnt. sin. ......

VV. pulmonales (from the }
Ch) s:) Soe Gee ees j

Aorta (to the body), AA. car-
diac s. coronarie (to the
heart from the base of the

Bicuspidess. mi- {Septalis, |
trales... Lateralis. t

Semilunares aor- Dosealis,
1. eee
|

A. Great Cavities (Loculi).

ds Reception: < i. s. =. 56%. <:6
OE IGUIV BEY nis 0's 0's:e echo inin's/s

B. Divisions of Great
Cavities:

TOF anvicless s 56s .555 555

C. Orifices and Vessels.

(1. Auriculo-ventricular or
? interlocular... .....

§ 2. Vasa afferentia (enter-
i ing the auricles)... .

3. Vasa efferentia (leav-
ing the ventricles)...

D. Valves (Valvz) and the
Parts associated there-
with. 5

ha Auriculo-ventricular t

WALVOS ptsahers ea et

2. Chorde tendinez.......
3. Columne carnee#.......

4. Arterial valves.........

Auricula dextra.
Ventriculus dexter.

pair appendix; fossa

ovalis.
Base; apex; conus arteriosus.

Orificicum aur.-vnt. dxt.

‘(from the body); VV.
cardiace 9s. coronarize
[ (from the heart).

VV. precava et postcava

A. pulmonalis (to the lungs).

Septalis,
Tricuspides. ... ~ Dorsalis,
Ventralis,
Chd. tnd. dxt.
Clm. crn. dxt.
2 Ventralis,
Semilunares Dextra,
pulmonales. . Sinistra.

Sn. Vis. dxt. (3), Valva
{ Thebesii.

E. Single Parts belonging equally to Both Sides.—1. Septum auriculare. 2. Sep-
tum ventriculare. 3. Ductus arteriosus.

THE CARDIAC CAVITIES. 323

Fig. 92.—Diagrammatic representation of the heart, the great vessels, the pulmonic
and systemic capillaries.

In this diagram, as in Fig. 91, the heart is seen from its dersal (posterior) aspect ; hence
its right and left portions correspond in position with the right and left of the observer (§ 56).

Most of the parts are shown by outlines only, but the ventricular and auricular walls
are shaded, and the lines representing the aorta and pulmonary artery are made a little
heavier than those representing the vena cava and pulmonary vein.

The course of the blood is indicated by arrows, but the action of the parts will be
considered in Part III. The difference between the valves upon the two sides will be
explained in connection therewith.

x~ trachea

homé cardia deyera
SAulmona /v's

peTin Pua Tied

Kemi cardia sinistra
‘i sys temica

para

fala
(f uns) as
Ne
“% rink ot Yi
kr ov dxt FA
s. < put ee oe
\ (* SY s(nus po
+ zs © (hi {
Au — WAAL Sinus Val salvae~ .\ J 7858 ove /'s Cad
mi. yori fede q Valva Seyi Unarts--—s§
basis- A eantigs f A.carade ca fori ®
i — GG icushis V \"
A} _ - Chetdafensline a--~~- :
i wae ud

ee
Wey

}
.,
}

-f hemi septum ventricut/are-

—_

SS oe
Ys Eon ice Vena CaOyY

Fra. 92.—DIAGRAM OF THE CARDIAC CAVITIES, ETC. ; DoRSAL ASPECT.

§ 845. The special objects of this diagram are :-—

1. To represent the more essential parts of the heart in a single figure, to give their
full technical names, and to indicate the relations of the cavities to each other and to the
great vessels.

2. To illustrate the physiological fact that the mammalian heart, in the normal adult,
really consists of two organs whose cavities have no direct communication whatever.

3. To show the many points of resemblance between the right and left portions.

4. To indicate the relations of the two portions of the heart, through their afferent and
efferent vessels, with the lungs and the other organs of the body, and thus to justify the
apparent paradox that whereas, anatomically, the heart may properly be described as a
single and approximately mesal organ, situated between the two lateral masses of the
lungs, physiologically, the right and left portions of the heart are separated, on the one hand
by the lungs and on the other by the rest of the body. Anatomically, there are two lungs

324 ANATOMICAL TECHNOLOGY.

and the heart lies between them ; physiologically, the lungs form a single organ which is
interposed between the two hearts ; Wilder, 1.

§ 846. The diagram (Fig. 92) differs from an accurate representation of any actual
section of the cat’s heart in the following respects :—

1, The separation of tue right and left portions (hemicardi@), involving the splitting
of the septa auriculare et ventriculare and the elongation of the ductus arteriosus.

2. The non-crossing of the aorta and A, pulmonalis and the deflection of the former to
the right instead of the deft.

8. The representation of the cardiac (coronary) vessels by the beginnings of the two
arteries and the ends of two of the veins.

4. The representation of the systemic veins ( postcava, precava and V. azygos) by a single
vessel here named V. cava.

5. The representation of the several V V. pulmonales by a single vessel.

6. The representation of the two lungs by a single and simple sac.

7. The distance from one another upon the areus aorticus of the origins of the vessels
supplying the head and arms, AA. brachio-cephalica et subclavia sinistra (A. breph., A.
sbelv.).

8. The representation of the branches and capillaries of the aorta and A. pulmonalis by
only three divisions of each vessel.

9. The representation of the semilunar and auriculo-ventricular valves in each case by
a pair of lines,

10. The omission of the fret-work upon the ental aspect of the walls, especially of the
ventricles and the auricular appendices.

11. The positions and points of attachment of the appendices and of the veins which
enter the auricles have been assigned with a view to convenience of representation rather
than absolute accuracy.

12. The omission of the ductus thoracicus, which might have been made to join the
proximal portion of the Vena cava.

§ 847. The right and left portions (hemicardia) of the heart agree with each other in
the following respects :—

1. Their primary division into an auricle (auricula), which is relatively cephalic in posi-
tion, irregular, rounded and thin walled ; and a ventricle (ventriculus), which is caudal in
position, regular, pointed and thick walled.

2. The division of each auricle into a larger sinus and a smaller appendiz.

8. The communication of each auricle with its ventricle by a slightly constricted orifice,
guarded by valves of irregular shape.

4. The attachment of cusps of the free edges of the auriculo-ventricular valves to the
ventricular walls by fibrous chorde tendinee springing from the apices of columne@ carnee.

5. The free communication of the auricles with veins (VV. cave and VV. pulmonarie).

6. The exit from the ventricles of arteries (aorta and A. pulmonalis).

7. The guarding of each arterial orifice by three similar and regular semilunar valves.

8. The expansion of each artery opposite the valves to form three sinuses of Valsalva.

9. The aorta and A. pulmonalis are united by a fibrous band, the ductus arteriosus,
the normally impervious remnant of a vessel which, in the foetus, permitted the blood to
pass from the latter vessel into the former peripherad of the origin of the vessels (AA.
brachio-cephalica et subclavia sinistra) which carried the purer maternal blood to the head
and arms.

§ 848. The right and left portions (hemicardie) of the heart differ in the following
respects :—

LIST OF ABBREVIATIONS. 325

1. The afferent vessels (VV. cave) of the former come from the body in general, those
of the latter (V V. pulmonales) from the /ungs. The efferent vessels of the former (AA.
pulmonales) go to the Jungs, and those of the latter (aorta) to the body in general.

2. From two of the aortic sinuses of Valsalva arise the two AA. cardiace which are
distributed to the substance of the heart itself.

8. Into the right auricle open the V V. cardiace which come from the substance of the

heart.

4. The septal wall of the right auricle presents an oval depression, fossa ovalis, the
indication of a thin portion of the septum which, in the foetus, was absent, so as to permit
the existence of the foramen ovale (§ 868).

5. The lateral walls of the left ventricle are, upon the whole, from two to three times

the thicker.

6. The right ventricle is prolonged as a conus arteriosus from which arises the A. pul-
monalis.

7. The auriculo-ventricular valves on the right form three divisions, hence named VV.
tricuspides, while those of the left form two, hence named bicuspides or mitral.

8. The foregoing are real and constant distinctions between the right and left hearts,
In addition, in the diagram, on the left side, the semilunar valves are represented as closed,
forming bags whose convexities bulge toward the ventricle as if pressed upon by a column
of liquid in the artery ; the tricuspid valves are also closed, as if by the pressure of a vol-
ume of liquid in the ventricle ; they are restrained from being carried into the auricle by
the chorde tendinee.

§ 849. List of Abbreviations of Cardiac Names.—Ao., Aorta,
§ 851.—Are. ao., Arcus aorticus, § 854.—A. breph., Arteria brachio-
cephalica, § 855.—A. erd., Arteria cardiaca, § 856.—A. plm., Ar-
teria pulmonalis, § 857.—A. sdclv., Arteria subclavia, § 858—Awr.
dxt., Auricula dextra, § 859.—Awr. sin., Auricula sinistra, § 860.—
Chd. tnd., Chord tendines, § 864.—Clm. car., Column carnee,
§ 865.—Con. art., Conus arteriosus, § 866.—Dct. art., Ductus ar-
teriosus, § 867.—/’s. ov., Fossa ovalis, § 868.—O7/. aur-vnt., Orifi-
cium auriculo-ventriculare, § 870.—Pcv., Postcava, § 871.—Prev.,
Preecava, § 872.—Spt. aur., Septum auriculare s. auricularum,
§ 873.—Spt. vnt., Septum ventriculare s. ventriculorum, § 874.—
Sn. aur. dzt., Sinus auricule dextre, § 875.—Sn. aur. sin., Sinus
auricule sinistre, § 876.—Sn. cor. s. crd., Sinus coronarius s. car-
diacus, § 877.—Sn. Vals., Sinus Valsalvee, § 878.—Tbel. Low.,
Tuberculum Loweri, § 880.— Viv. bic., Valva bicuspis, § 881.—
Viv. slnr., Valva semilunaris, § 882.— Viv. Thb., Valva Thebesii,
§ 883.— Vio. tre., Valva tricuspis, § 884—V. az. Vena azygos,
§ 885.— V. erd., Vena cardiaca s. coronaria, § 887.—V. cv., Vena
cava, § 886.— V. plm., Vena pulmonalis, § 888.— Vnt. dzt., Ventric-
ulus dexter, § 889.— Vnt. sin., Ventriculus sinister, § 890.

§ 850. Descriptive List of the Parts of the Heart.—The be-
ginner may find it advisable to read over this list with reference to

326 ANATOMICAL TECHNOLOGY.

the figures, before undertaking the dissection and detailed examina-
tion of the organ. Later, however, he should again consult it for
the descriptive portions.

§ 851. Aorta (az.), Ao. (Fig. 91, 92, 93, 94, 95, 96, 99, 100, 101, 102,
103, 107, 108).—The large artery springing from the base of the left
ventricle and giving off branches to all parts of the body. Its cen-
tral portion (as shown in Fig. 91, 101, 102, 108) is strongly arched,
and is thence named arcus aorticus. It then passes through the
thorax into the abdomen, and the diaphragm therefore indicates
the point of demarcation between the aorta thoracica and the aorta
abdominalis. This vessel is sometimes, as by Stowell (1), called
A. (Arteria) aorta, but the single word seems to be sufficient.

§ 852. Apex (ventriculi).—The smaller or caudal end of either

ventricle, and of either the cavity or the fleshy wall thereof (Fig. 91,

92, 93, 98).
§ 853. Appendix (auriculz)—The ventral extension of either auri-

cle (Fig. 91, 95, 96).—The other and larger division of the auricle isthe |

sinus. The limits of the two divisions are not clearly defined, but
as a whole the ental surface of the appendix presents more corruga-
tions. Sometimes the appendix is called auricle, and the entire
cavity is then known as atriwim.

§ 854. Arcus aorticus (az.), arc. ao—The arch of the aorta
(Fig. 92, 101, 102, 108).—See aorta (§ 851) and the explanation of
Fig. 101, 102.

§ 855. Arteria brachio-cephalica (az.), A. breph.—The brachio-
cephalic artery (Fig. 91, 92, 101, 102, 103, 107, 108)—See explana-
tion of Fig. 102.

§ 856. Arteria cardiaca, A. crd.—A cardiac or coronary artery
(Fig. 91, 92, 93, 94, 102).—There are two cardiac arteries, arising
from the aortic sinuses of Valsalva and distributed to the substance
of the heart. As seen in Fig. 102, they arise respectively from the
right and left sinuses, and are distributed to the corresponding re-
gions. The mouth of the right one is shown in Fig. 94. It is noé cov-
ered by the valve when the latter is opened ; see W. T. Sedgwick (1).

§ 857. Arteria pulmonalis (az.), A. plm.—The pulmonary ar-
tery (Fig. 91, 92, 93, 95, 99, 100).—This springs from the conus
arteriosus at the base of the right ventricle, passes sinistro-cephalad
and ventrad of the aorta, and divides into two (A. plm. dat. and A.
pln. sin.), which carry blood to the right and left lung respectively.

PARTS OF THE HEART. 327

§ 858. Arteria subclavia, A. sbclv. sin.—The subclavian ar-
tery (Fig. 91, 92, 101, 102, 108).—This arises from the areus aorticus
just peripherad of the A. brachio-cephalica. On Fig. 92 the abbre-
viation sin. is omitted.

§ 859. Auricula dextra, aur. dzt—The right or pulmonary
auricle (Fig. 91, 92, 93, 94, 95, 99, 100).—The cavity of the auricle
is divisible into a larger sinws, dorsal in position and smoother
walled, and a smaller appendiz, more ventral in position and with
corrugations and recesses upon the ental aspect of the wall. Into
the right auricle venous blood is poured through the postcava,
precava and the V V. cardiace.

§ 860. Auricula sinistra, aur. sin.—The left or pulmonary auri-
cle (Fig. 91, 92, 93, 95, 96, 99, 100).—Like the right, the left auricle
presents a sinws and an appendiz. Purified blood is brought to
it by the V V. pulmonales.

§ 861. Basis.—The base of either ventricle or of the entire ven-
tricular portion of the heart.

§ 862. Capillarie pulmonales—The capillaries of the lungs.—
In Fig. 92, these are diagrammatically represented by three subdi-
_ visions of the single A. pulmonalis. In reality they are exceedingly

numerous and minute.

§ 863. Capillarie systemice—The systemic capillaries.—The
exceedingly numerous and minute subdivisions of the branches of
the aorta are represented in Fig. 91 by three.

§ 864. Chorde tendinee, chd. tnd.—The tendinous cords con-
nected with the free borders of the awriculo-ventricular valves on
both sides (Fig. 92, 93, 94 A).—These cords are very strong and
inelastic. Their other ends are connected with the apices of the
columne carnee, and they serve to prevent the free borders of the
bicuspid and tricuspid valves from being forced back into the auri-
cles at the time of the ventricular systole.

§ 865. Columnz carnee, cli. car.—The fleshy columns of the
ventricles (Fig. 91, 93, 94, 97, 98)—There are two large columns
in the left ventricie and a variable number of smaller ones in the
right. Consisting of muscle like the ventricular walls themselves,
these columns are supposed to contract and thus keep the chorde
tendinee from becoming lax at the ventricular systole.

§ 866. Conus arteriosus (dzt.), con. art—The arterial cone or
bulb from which springs the A. pulmonalis (Fig. 91, 92, 94, 100).—

3828 ANATOMICAL TECHNOLOGY.

This is a conical prolongation of the base of the right ventricle at its
left corner, and is continued into the A. pulmonalis. Ina heart of -
average size its length is about 1 cm. Since there is no correspond-
ing prolongation of the left ventricle, the semilunar valves of the
aorta are upon a ‘‘lower”’ level than those of the A. pulmonalis,
z. é., they are nearer the apex of the ventricle (Fig. 94). The
ental surface of the conus is smooth.

§ 867. Ductus arteriosus (qz.), dct. art. (Fig. 92).—By an over-
sight, this very significant remnant of an important foetal structure
is not represented upon any of the figures of actual preparations.
It is slight and easily overlooked in even a somewhat careful exam-
ination of the parts. We have never observed any depression cor-
responding with its attachment to the A. pulmonalis, and in the
_ aorta the depression is usually very indistinct. The ductus begins
at the cephalic side of the A. pulmonalis, just centrad of its bifurea-
tion, and extends very obliquely along the slight interval between
the artery and the aorta, to become attached to the latter a little
peripherad of the origin of the A. subclavia sinistra, and some-
what at the ventral as well as caudal side of the vessel.

§ 868. Fossa ovalis (@z.), H's. ov.—The oval depression upon the
right side of the septum auriculare (Fig. 91).—This is not dis-
tinctly represented upon any of the figures of actual preparations.
It is most easily seen after the lateral wall of each auricle has been
removed and the septum is held between the eye and the light. At
about the middle of the septum there will appear a thinner area,
bounded cephalad and ventrad by a more or less distinct thicken-
ing. The thin portion is usually oval, and measures about 5 x 2.5
mm. In the kitten before birth, the thin area is more or less com-
pletely absent, so that the two auricles communicate, and the blood
from the postcava passes through the orifice, the #m. ovale, into the
left ventricle. Respecting the significance of the fossa ovalis and its
appearance in the human heart, see the works cited and also Quain,
A, II, 799-803, and Dalton, A, 699.

On the left side of the septum, the area corresponding with the
position of the /’s. ovalis is sometimes quite smooth, but more often
presents (as in Prep. 360, Museum of Cornell University) a crescentic
elevation at its dorsal side.

§ 869. Hemicardia dextra—The right side or portion of the
heart.—Since the entire organ is called heart or cardia, it is logi-
cally incorrect to speak of the two sides as the right heart and the

PARTS OF THE HEART. 329

left heart. The term hemicardiais analogous with the words hemi-
_ sphere, hemipteron, etc. The left auricle and ventricle constitute
the hemicardia sinistra.

Hemiseptum auriculare and hemiseptum ventriculare.—Not
only ideally, as in Fig. 92, but actually may the interventricular
septum be divided so that a portion remains as the mesal wall of
either ventricle. Strictly speaking, each of these parts is not a sep-
tum, but a hemiseptum, but practically the latter term need seldom
be employed.

§ 870. Orificium auriculo-ventriculare dextrum, o7/. aur.-vnt.
dat,—The right auriculo-ventricular orifice (Fig. 92, 93, 96, 97, 99).
—This is the slightly constricted communication between the right
auricle and ventricle. It is guarded by the tricuspid valves.

The similar orifice between the left auricle and ventricle is
guarded by the bicuspid valves.

§ 871. Postcava (az.), pcv.—The posterior or caudal vena cava
or V. cava inferior s. ascendens (Fig. 91, 92, 95, 101, § 955).—This
large vein enters the right auricular sinus on its dorsal aspect near
the ventricle. Respecting the name, see § 886.

§ 872. Precava (az.), prcv.—The anterior or cephalic vena cava
or V. cava superior s. descendens (Fig. 91, 92, 93, 95, 101, § 919).
—This opens into the right auricular sinus at its cephalic aspect,
just dorsad of the arch of the A. pulmonalis.

§ 873. Septum auriculare (az.), spt. auwr.—The partition be-
tween the right and left auricles (Fig. 93, 95, 96, 99).—This is hardly
thicker than the lateral auricular wall and is very thin at the fossa
ovalis. In Fig. 93, what is named septum embraces also the mass
of connective tissue between the aorta and the bifurcation of the
septum proper as seen in Fig. 96. The septum is really between
only those larger portions of the auricles known as the sinuses.

§ 874. Septum ventriculare (az.), spt. ont.—The partition be-
tween the right and left ventricles (Fig. 93, 97, 98)—The septum is
about as thick as the lateral wall of the left ventricle.

§ 875. Sinus (auricule dextre), sn. aur. dxt.—The sinus or
larger and more dorsal portion of the right auricle (Fig. 91-96).—
Its walls are smoother within than those of the appendix. Into it
open the postcava, the precava and the V. cardiaca.

§ 876. Sinus (auricule sinistree), sn. aur. sin.—The left auricu-
lar sinus (Fig. 91, 92, 93, 95, 96).—The larger and more dorsally

330 ANATOMICAL TECHNOLOGY.

placed portion of the left auricle. Entad its walls are smoother
than those of the appendix, and into it open the VV. pulmonales.

§ 877. Sinus coronalis s. cardiacus, sn. cor. s. crd—The sinus
of the coronary vein.—This is not distinctly shown in any of the
figures. Its position is indicated on Fig. 91 by the abbreviation
V. erd. Both the sinus and the semilunar valve at its opening into
the auricle are readily found by examining the dorso-caudal angle
of the auricle close to the septum. Into the sinus open not only the
principal V. cardiaca, but one or two smaller ones.

§ 878. Sinus Valsalve, sn. Vals.—One of the six sinuses of
Valsalva (Fig. 92, 94, 96).—TThere are three of these at the mouth
of the aorta and that of the A. pulmonalis. Each sinus may be
described as an enlargement of the base of the vessel occupying a
little less than one third of its circumference. Each is partly cov-
ered by a semilunar valve (§ 882), and is thus open peripherad but
closed centrad or toward the ventricle. As in man, they may be
designated as approximately dorsal, dextral and sinistral in the
aorta, and ventral, dextral and sinistral in the pulmonary artery.
From the right and left aortic sinuses arise the two AA. cardiace
or ‘‘ coronary ”’ arteries.

§ 879. Trabecula tenuis.—This name is applied, provisionally,
to a slender and apparently fibrous filament which, in the prepara- -
tion from which Fig. 98 was taken, spans the right ventricle near its
apex. Its septal end springs from an independent little muscular
elevation ; its lateral end is attached to the base of a columna car-
nea. In Fig. 98 it is represented much too large; it is really hardly
thicker than a spider’s thread. Can it be the insignificant repre-
sentative of the ‘‘moderator band’’ of Ruminants (Rolleston, B,
25-35) ?

§ 880. Tuberculum Loweri—The tubercle of Lower.—This and
the Eustachian valve, both of which have been described in connec-
tion with the fossa ovalis of some Mammals, we have not yet deter-
mined the distinct presence of in the cat. According to Hyrtl
(A, 290), the former rarely if ever appears in the human heart.

§ 881. Valva bicuspis, /v. bic.—One of the two bicuspid or
mitral valves (Fig. 92, 93, 96, 97, 99).—As in man, one of these wide
valves is at the left or lateral side of the auriculo-ventricular orifice,
and the other is toward the septum, thus also overhanging the
entrance to the aorta.

- PARTS OF THE HEART. 331

§ 882. Valva semilunaris, v/v. s/mr.—One of the six semilunar
or sigmoid valves (Fig. 92, 94, 96, 100)—The mouths or bases of
the aorta and A. pulmonalis are guarded each by three of these
valves. Their free borders are nearly even, and naturally look
peripherad. Like the sinuses of Valsalva, which they partly cover,
the three aortic valves are approximately dorsal, dextral and sinis-
istral respectively, while those of the pulmonary artery are approx-
imately ventral, dextral and sinistral.

§ 883. Valva Thebesii (az.), v/v. Thb—The valve of Thebesius.—
This name has been applied to the semilunar valve at the entrance
of the V. cardiaca through the sinws coronarius into the right
auricle (Quain, A, II, 246). It is easily seen in the cat.

§ 884. Valva tricuspis, v/v. t7c.—One of the three tricuspid
valves (Fig. 92, 93, 94, 96, 97, 99).—As in man, one of these right
auriculo-ventricular valves is nearer the septwm, while the other two
are, approximately and relatively, dorsal and ventral. There is
considerable variation in their form. Usually the free border is quite
irregular, but in the preparation from which Fig. 94 was taken,
the free border is even and the chorde tendinee are attached at the
lateral edges.

§ 885. Vena azygos (az.), V. az.—The azygous vein (Fig. 91, 99,
101, § 920).—This vein opens into the precava about 1 cm. peripherad
of its junction with the right auricle.

§ 886. Vena cava (az.), V. cv—The adjective cava is applied to
either of the two great veins through which the impure blood is
brought from the organs in general to the right auricle. It is more
commonly employed for the longer and larger of the two, which
traverses the abdomen and penetrates the diaphragm. By Owen
(A) the two are designated as the postcaval and precaval veins.
The vessels are so large, so important and so often mentioned, that
we have ventured to omit the vena and to designate them as simply
precava and postcava. In the diagram (Fig. 92) the single Vena
cava represents both pracava and postcava.

§ 887. Vena cardiaca, V. crd.—One of two or more cardiac or
coronary veins (Fig. 91, 92).—The blood which has traversed the
tissues of the heart itself is returned to the right auricle by one
large and one or more smaller veins, all of which open into a small
sinus (sv. coronalis), which has been described above (§ 877).

§ 888. Venz pulmonales—The pulmonary veins (Fig. 91, 92).—

332 ANATOMICAL TECHNOLOGY.

Near the deft auricle these form three wholly distinct groups of two
each, which from their position may be called deztral, sinistral and
intermediate or dorsal. |

Disregarding the smaller subdivisions, some of which are not
represented in the figures, each group consists of two trunks which
open into the auricle by a common sinus of varying depth.

The intermediate and the sinistral sinus are indistinctly seen in
Fig. 95 at the ends of the lines drawn from the abbreviation VV.,
but the separate orifices of the veins do not appear. The dextral
sinus could not be shown in the same figure, but its position is
indicated approximately by the s of the word septum.

When traced to the lungs, it is found that the deztral and sin-
istral groups come from the right and left lungs respectively, but
that of the two large constituents of the intermediate, the one nearer
the right comes from the lung of that side, and the other from the
left.

In man, there are usually two pulmonary veins on each side,
opening independently into the auricle.

§ 889. Ventriculus dexter, ont. dzt.—The right or pulmonary
ventricle (Fig. 91, 92, 93, 94, 97, 98, 99)—This is not only, as its
name implies, relatively dextral in position, but also, in the natural
attitude of the organ, somewhat more ventral than the left ventricle.
Its walls are markedly thinner than those of the left, and its cavity
does not so nearly reach the apex of the organ. The ental surface
of its walls presents numerous elevations and depressions. In addi-
tion to the columne carnee and the trabecula tenuis, there are
many muscular trabecule passing obliquely from one part of the
wall to another, forming a sort of coarse network. The sinistro-
cephalic corner of the ventricle is devoid of reticulations, and is
prolonged as the conus arteriosus (§ 866).

§ 890. Ventriculus sinister, ont. sin.—The left or systemic ven-
tricle (Fig. 91, 92, 93, 94, 97, 98, 99).—This is not only sinistral,
but also, relatively, somewhat more dorsal in position in the natu-
ral attitude of the heart. Its lateral walls are 2-3 times as thick as
those of the right ventricle, and its cavity reaches more nearly to
the apex of the organ. In the contracted state of the heart, the left
ventricle occupies the more space on account of the greater thick-
ness of the walls (Fig. 93) ; but the thinner walls of the right yield
more to the pressure of an injection, and its cavity generally appears
more capacious (Fig. 91, 97, 98). It presents two large columnze

LONGITUDINAL SECTIONS OF THE HEART. 333

carne and some other slight irregularities, but not the reticulations
which exist in the right ventricle. The aorta springs from the base
of the ventricle close to the septum.

1 semilunans
Valva tricuspis

Sy
he
a “SH
iy) >
Gow oy
“a 38
+ A.cardiaca
uv < dextra
= PS Sinus
(2 Ry. Valsalva
3 Valva

Valvg

Ventriculus
sinister

SIO Nag

THE HEART, SHOWING THE RIGHT SINUS
Fie. 98.—THE DorsaL Part OF THE HEART, OF VALSALVA AND CARDIAC ARTERY;
SEEN FROM THE VENTRAL ASPECT; x 1.5. x 1.5.

§ 891. Explanation of Fig. 93.—Longitudinal, dextro-sinistral section of the entire
heart, seen from the ventral surface.

Preparation.—This was the heart of a very large male (castrated) cat, a gift from
Messrs. Melvin & Badger of Boston, Mass. From the same cat were taken the scapula
and humeri, ribs and vertebre shown in Fig. 43-46, 50, 68-71.

The heart was not injected or prepared in any special way, excepting hardening in
alcohol upon cotton. Hence the cavities are small and the auricles corrugated. When
hard, it was divided by a longitudinal dextro-sinistral incision with a large sharp scalpel.
The dorsal part is here represented ; the ventral part is a little the thicker.

The special object of the preparation is to exhibit the relative positions and oonnections
of the four great cavities with the auriculo-ventricular valves. In addition, there are
shown, (A) the entrance of the preeava, which has been longitudinally divided ; (B) the
point of entrance or mouth of the postcara, as a dark spot at the beginning of the word ;
(C) the aorta and pulmonary artery (A. plm.); both are transected, the former just at the

334 ANATOMICAL TECHNOLOGY.

place of origin of the A. brachio-cephalica ; (D) the right and left cardiac arteries imbedded
in the fat at the line of junction of the auricles and ventricles ; (E) the part marked septum
auricularum is not truly part of the septum, but the thick tissue ventrad of it as seen in
Fig. 96.

§ 892. Fig. 94—Preparation.—This represents nearly the dextro-ventral fourth of
the heart, but the two planes of longitudinal section are not quite at right angles with
each other, and the preparation is so placed that both are foreshortened.

The special object is to show the dextral wall of the central part of the aorta, with the
dextral sinus Valsaloe and the mouth of the corresponding A. cardiaea. ‘This latter is
seen to be so high up that it would not be covered by the V. semilunaris even when fully
extended (§ 856).

At the left are seen the cavity of the conus arteriosus, with a very small piece of the
A. pulmonalis, and one of the semilunar valves, which is decidedly upon a higher (more
cephalic) Jevel than those of the aorta (§ 866).

It will be understood that the communication between the right ventricle and the conus
is behind the septum ventriculare.

Fre, 95.—TRANSECTION OF THE AURICLES, CAUDAL ASPECT; x1.5.

§ 893. Fig. 95-98—General Description and Mode of Preparation.—These four
figures represent transections of the same heart through the auricles (Fig. 95, 96) and
through the ventricles (Fig. 97, 98), and as viewed from the caudal (Fig. 95, 97) or the
cephalic (Fig. 96, 98) aspect. The heart had been distended and hardened with alcohol
(§ 842), and was then transected with the large scalpel at two levels.

In comparing the figures as representing continuous parts of the same organ, Fig. 97 is
to be imagined inverted upon Fig. 98, the inversion being from left to right ; then Fig. 96 is
to be placed upon Fig. 97 without inversion, and Fig. 95, inverted as before, upon Fig. 96.
The entire heart will then, in the mind, be as if viewed from the base with the ventral
aspect toward the observer, so that the right and left sides are inverted as compared with his,

§ 894. Fig. 95—The Interior of the Auricles from the Caudal Aspect.—The figure
illustrates the extent of the septum avriculare, and the fact that the auricular sinuses
appear upon the dorsal aspect, while on the ventral there are to be seen only the appen-

TRANSECTION OF THE AURICLES. 335°

dices projecting on either side of the aorta and pulmonary artery. Of these two vessels,
the former is seen to be nearly in line with the auricular septum, while the latter, at this
level, is ventro-sinistrad of it. The middle of the length of the septum auriculare should
have been thinned to indicate the position of the fossa ovalis (§ 868). In the left auricle
the two ends of the line which is interrupted by the abbreviation V V. point respectively
to the positions of the dextral and sinistral sinuses of the pulmonary veins (§ 888); the
third or intermediate sinus is overhung by the auricular septum, and its position is indi-
cated approximately by the s of the word septum. A little of the complete wall of the
postcava remains, but the place of attachment of the precava is indicated only by an
unshaded area.

§ 895. Fig. 96—The Auricles and Auriculo-ventricular Orifices seen from the

Fic. 96.—TRANSECTION OF THE AURICLES, CEPHALIC ASFECT; x 1.5.

Cephalic Aspect.—In addition to the features in common with Fig. 95, this figure illus-
trates the following points :—

(A) The relative positions of the three semilunar valves of the pulmonary artery,
namely, ventral, dextral and sinistral.

(B) The fact that the aortic valves are upon a lower (more caudal) level than the pul-
monary, the former, indeed, not distinctly appearing unless the preparation is so held as
to admit the light directly into the vessel (§ 866).

The auriculo-ventricular valves are not especially well shown, but the form of the two
unshaded areas indicates, approximately, the fact that of the two bicuspides (§ 881), one is
lateral and the other septal, while of the three tricuspides (§ 884), one is septal and the
others respectively dorsal and ventral (more strictly dorso-lateral and ventro lateral).

In the right auricle, the word sinus designates the general cavity of the auricle aside
from the appendix ; but in the corner, and pointed at by the words sinus and septum, is
the location of the small sinus of the cardiac veins (§ 887).

§ 896. Fig. 97.—The Ventricular Cavities, from the Cephalic Aspect.—In this
and Fig. 98, the most striking features are (A) the greater thickness of the lateral wall of
the left ventricle, in relation to its office of propelling the blood over all parts of the body,
and (B) the larger size of the cavity of the right. The difference of size is artificial, and
due to the less resistance offered by the thinner wall to the pressure of the injected alcohol.

In the left ventricle is seen the cut end of one of the columne carne, still attached to

336 ANATOMICAL TECHNOLOGY.

Fie. 97.—TRANSE TION OF THE VENTRICLES, CAUDAL ASPEET; x15. °

the lateral bicuspid valve by its chorde tendinee. In the right, the surface adjacent to

the place of exit of the pulmonary artery is seen to be smoother than in other parts
(§ 866).

™
"Zé carnede

Fig. 98.—TRANSECTION OF THE VENTRICLES, CEPHALIC ASPECT; x1.5.

§ 897. Fig. 98—The Ental Aspect of the Apices of the two Ventricles.—In addi-
tion to points in common with Fig. 97, this figure well displays the very numerous reticu-
lations and trabecule of the right ventricle, and. especially the presence of a very delicate
fibrous band, provisionally named trabecula tenuis, which connects the septum with the
“ateral wall (§ 879).

DISSECTION OF THE HEART.

§ 898. After the careful inspection of the organ as a whole, and
the study and comparison of the various sections represented in
Fig. 93-98 (or at least of the figures if such preparations have not
been made), the heart should be dissected as follows :—

DISSECTION OF THE HEART. 337

Instruments and Materials.—Sharp Charriére scalpel ; coarse
or medium curved scissors; silver probe, syringotome or dull
tracer; 15 per cent. glycerin ; a heart, the larger the better, with the
pericardium removed. The dissection may be done upon a fresh
specimen or upon one simply hardened in alcohol; it is easier,
however, if the organ has been distended and hardened with alco-
hol (§ 842).

§ 899. Auricula dextra.—Pinch up with the forceps a bit of the
lateral wall of the right auricle, for example, just dorsad of the
appendix, and remove it with the scissors. Introduce the probe
and ascertain the points of emergence of the postcava and precava.
With the scissors, remove the entire lateral wall, including that of
the appendix, but leave the attachments of the cave.

Note (A) the smoothness of the ental surface of the sinus as com-
pared with the fretwork in the appendix ; (B) close to the auriculo-
ventricular furrow, just caudad of the posteava, the orifice of the
sinus coronalis (§ 877), guarded by the valoa Thebesii (§ 883).

§ 900. Ventriculus dexter.—Pass the probe through the orifi-
cium auriculo-ventriculare into the right ventricle, noting that no
obstruction is offered by the tricuspid valves. Ascertain by prob-
ing the limit of the ventricular cavity, and with the scalpel make a
V-shaped flap having its base at the base of the ventricle and
including the entire lateral wall.

Turn this flap toward the auricle and note: (A) the two or three
columne carnee ; (B) the smaller trabecule, both fleshy and ten-
dinous; (C) the chorde tendinee passing from the columns or
directly from the ventricular wall to the borders of the three valve
tricuspides ; (D) that two of these valves (dorsal and ventral) will
‘be moved by the lifting of the flap; the third (septal) is applied
closely to the septum, and its chorde are very short, arising either
from the septum directly or from very slight elevations.

§ 901. Conus arteriosus and A. pulmonalis.—Pass the probe
sinistro-cephalad through the conus into the artery. Then introduce
a scissors blade in the same direction and slit both up along the most
prominent part of the convexity. On divaricating the sides, it will
be found that the incision has either divided the ventral semilunar
valve or gone between it and the dextral. Note (A) the three valves ;
(B) the corresponding sinuses of Valsalva; (C) the bifurcation of
the A. pulmonalis into right and left branches to the corresponding

lungs.
22

338 ANATOMICAL TECHNOLOGY.

Ventriculus sinister.—It is easier to defer the examination of
the left auricle until after the simpler ventricle has been opened.

With the scalpel, make a longitudinal incision through the
lateral wall about midway of the width of the ventricle. This will
permit a view of the cavity without injuring the massive columne
carnese which will generally appear one at either side. Then make
a transverse incision at right angles with the basal end of the first,
making sure that it is on the ventricular side of the furrow between
the auricle and the ventricle. With the scalpel, remove the enclosed
angles of the wall on either side so as to expose the cavity as much
as desirable. Note that one of the wide bicuspid valves is applied
against the septum so as to conceal the orifice of the aorta. |

§ 902. Aorta.—Pass the scissors blade behind the septal bicuspid
valve into the aorta and slit it up. The incision will probably cut
through one of the three semilunar valves. Note (A) the position of
these valves, dorsal, dextral and sinistral ; (B) the corresponding
sinuses of Valsalva ; (C) the orifices of the right and left cardiac
arteries from the dextral and sinistral sinuses.

Farther peripherad, note (A) the origins of the brachio-cephalic
and left subclavian arteries ; (B) in some cases, at the opposite side
of the aorta from those vessels, a slight depression indicating the
place of attachment of the ductus arteriosus.

§ 903. Auricula sinistra.—Returning to the left ventricle, pass
the probe into the left auricle and ascertain the points of attach-
ment of the pulmonary veins nearest the appendix. Then intro-
duce a scissors blade and divide the parts from the ventricle just
dorsad of the appendix, carefully avoiding the veins just mentioned.

Slit up the appendix to its tip. Then with the probe, seek out
the orifices of the three groups of pulmonary veins as represented
in Fig. 91. Cut along the auriculo-ventricular furrow so as to per-
mit a better view of the cavity. Note the more or less marked
crescentic fold which indicates the dorsal margin of the fossa ovalis.
Hold the septum between the eye and the light and note its thin-
ness at that place. Examine the right side of the septum for the
Jossa and the left for the crescentic fold (§ 868).

FROZEN SECTIONS OF THE THORAX.

§ 904. Figures 99 and 100 represent respectively the caudal and cephalic aspects of a
frozen transection of the thorax, the thickness of the section being a trifle over 1 cm. The
manner of preparation has been described in § 324.

FROZEN SECTIONS OF THE THORAX. 339

These two figures may be compared with Fig. 101, 103, 107 and 109 in the present
work, and with Plates 1V and V of Dwight’s “ Frozen Sections of a Child ” (B)

§ 905. Level of the Sections.—So far as we can judge by comparison with dissections
and by the collation of these with the other sections of the same cat, the centrum of the
7th thoracic vertebra appears in Fig. 99, and that of tlie 6th in Fig. 100, the intervertebral
arthron being included in the thickness of the section. The section includes the bifurcation
of the trachea, which appears as a mesal tube in Fig. 100, into the two bronchi which
appear in Fig. 99 ; since plane surfaces only are shown, the ridge at the place of bifurca-
tion does not appear in Fig. 100. Between the esophagus and the vertebra in Fig. 100
appear the transections of the MM. longus colli ; but these terminate in the thickness of
the section, and in Fig. 99 the Vena azygos is seen to be joined by the first intercostal vein.

§ 906. The Heart.—From the fact that the heart was injected with plaster, while the
lungs were not injected at all, the former occupies a disproportionally large space. The
natural obliquity of the organ also interferes with the ready appreciation of the relations
of the parts which appear in the two figures.

In Fig. 99, the right and left correspond with those of the observer, while they are
reversed in Fig. 100. In the former, the vein presented includes a combination of the spe-
cial features which have been observed in the longitudinal section (Fig. 93) and the tran-
sections (Fig. 96,97). The non-injection of the left auricle accounts for the relatively
larger size of the right in Fig. 99, and for the non-appearance of the left in Fig. 100.

In Fig. 100, not only are the right and left parts reversed in position with respect to
the observer, but the appearances are less readily comparable with what are shown in the
other figures of the heart. The right auricle is divided near the point of entrance of the
precava, but the non-injected left auricle just escaped ; its cephalic end might fairly have
been placed in the vacant area just sinistrad of (deztrad of on the figure) the word A. pul-
monalis.

§ 907. Pleura (§ 806).—In both figures the lines representing the pleura are made dis-
proportionally heavy to facilitate their recognition.

The pleura is seen to form a continuous line upon the ental aspect of the thoracic pari-
etes, to be reflected off at each side of the vertebral centrum upon the adjacent structures,
and then to follow the contour of the lung to the heart, where it forms the ectal lamina of
the pericardium. At the ventrimeson it is reflected again upon the parietes. Hence, like
the peritoneum (§ 725), each pleura is a closed sac with continuous walls, and the viscera
which appear to be within its cavity are really outside and in contact only with its ectal
surface.

§ 908. Mediastinum.—The irregular space between the vertebra and the idtoarehand,
and bounded on the sides by the undulating line of pleura as it approaches the roots of the.
lungs, is the mediastinum. Within it are the wsophagus and trachea, the aorta and other
vessels and nerves.

§ 909. Septum mediastinale.—At the ventrimeson the right and left pleural reflec-
tions are in contact, and form an apparently single membrane between the two cavities,
which, as may be demonstrated very easily by experiment, are thus entirely disconnected.
In Fig. 99, the mediastinal septum so formed is very short, but in Fig. 100, the pericardium
is at some distance from the sternum and the septum is correspondingly extensive.

In man “(Quain, A, II, Fig. 163; Dwight, B, Pl. IV), these two reflected layers of pleura
do not meet at the level of the heart, and the small space between them is called the
anterior mediastinum. For comparison with man, therefore, the single mediastinum of
the cat should be called dorsal or posterior.

§ 910. Pericardium.—Like the pleura, the pericardium is represented upon the figures
by unnaturally heavy lines. In Fig. 99, near the ventrimeson, it is seen to consist of two

340 - ANATOMICAL TECHNOLOGY.

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BN

<3
a
}

Sp: Nh iT
ag ii

Ait 9
ae y

ventriculus
Sin cster

Fie. 99.—FrRozEN TRANSECTION OF THE THORAX AT THE HEART, CaUDAL ASPECT ;
x 1.5.

lamine embracing a deposit of fat (adeps pericardii). On both figures the ectal lamina
may be traced to the root of the lung on either side, where it is reflected to form the vis-
ceral pleura of those organs, and to the ventrimeson, where it is reflected at the septum

FROZEN SECTIONS OF THE THORAX. 341

if fh ig

aorta
ve ”

j

SoS
: Z:
Pa Loss

Fre. 100.—FR0ozEN TRANSECTION OF THE THORAX, CEPHALIC ASPECT; x 1.5.

mediastinule to become continuous with the parietal pleura. The ental lamina is reflected
to form the proper serous covering of the heart. At the dorsal points of junction of the
two lamine are the phrenic nerves.

The sternal arteries and veins appear dorso-laterad of the mesosterneber. The veins
lie mesad of the arteries (§ 921).

§ 911. Nerves, etc.—The sympathic trunks (N. sympathicus) appear just ventrad of
the heads of the ribs in Fig. 99, and in corresponding places in Fig. 100.

342 ANATOMICAL TECHNOLOGY.

The vagi (NV. vagus) lie ventro-laterad of the cesophagus and dorsad of the roots of the
lungs. The phrenics (N. phrenicus) lie just ventrad of the roots of the lungs, and at the
point of union of the ectal and ental lamine of the pericardium. The recurrent laryn-
geal nerves do not appear at these levels,

The ductus thoracicus is represented by a circle just dorsad of the aorta; its walls are
much thinner than here indicated, and are collapsed when the tube isempty. See Fig.
103, where, however, at this level, the duct is double.

BLOOD VESSELS OF THE TRUNK.»

§ 912. Special Instruments and Material.—Arthrotome ; scalpel; fine and coarse
scissors and forceps ; tracer; nippers ; injecting apparatus and material ($§ 180, 336).

Arteries, References.—Quain, A, I, 343; Gray, A, 75; Cuvier, A, VI, 100; Gegen-
baur (Lankester), A, 585; Hyrtl, A, 643; Bernard, A, 244; Milne Edwards, A, III. 511;
Leyh, A, 566 ; Owen, A, III, 532; Chauveau, A, 545 ; Chauveau (Fleming), A, 515 ; Gurlt,
A, 555; Straus-Durckheim, B, II, 183.

Veins, References.—Quain, A, I, 343; Gray, A, 564; Cuvier, A, VI, 226; Gegenbaur
(Lankester), A, 589; Hyrtl, A, 713; Bernard, A, 244; Milne-Edwards, A, III, 570 ; Leyh,
A, 625 ; Owen, A, III, 549 ; Chauveau, A, 636 ; Chauveau (Fleming), A, 596; Gurlt, A, 656.

§ 913. Preparation.—Inject the right V. jugularis externa with
fine blue mass (§§ 366 and 1450), and either the femoral artery or
the abdominal aorta with thin plaster (§§ 345, 352, 363).

See especially § 596 (10) for the method of dissecting vessels and
nerves. Vessels when uninjected may be distinguished from nerves
or bundles of connective tissue by cutting a slit-in them and demon-
strating their tubular character with the tracer.

Table of the Systemic Veins of the Trunk, and the Portal Veins
(Fig. 101, 103, 107).

The Table of Veins is like that of the Arteries (§ 916), inasmuch as the larger trunks
are placed first. It should be remembered, however, that the larger trunks are formed by
the smaller ones instead of dividing to give rise to the smaller ones, as with the arteries

(§ 819).
¥ § 914. THORAX AND NECK.

VV. cardiace (Fig. 91, § 887).
: V. azygos (§ 920).
Preecava (§ 019)... cece ccc enw c anc cnn ccocecesesenescwees j VY: utorn nee 923).

( V. vertebralis ($ 928).
Vena brachio-cephalica (§ 922). | V. subclavia (§ 924).
(The two brachio-cephalic veins { V. jugularis interna.
form the Precava)........... ‘ [ V. jugularis externa (§ 925). . f e.g gt
: alis.

ARTERIES OF THE TRUNK AND ARM. 343
§ 915. ABDOMEN.
{ V. phrenica (§ 956).
VV. hepaticz (§ 957).
V. adreno-lumbalis (§ 958).
Postcava (§ 955)...-....++--6-- 4 V. renalis (§ 959).......... V. spermatica sinistra.
V. ilio-lumbalis (§ 961).
‘ V. iliaca communis (§ 962). | bs: ee seein
{ V. mesenterica superior (§ 949).
V. art belt inferior (§ 950).
V. gastro-splenica (§ 951).
Vena porte (§ 952)............ + V. pancreatico-du ah alis (§ 958).
V. gastro-epiploica (§ 954).
| V. coronaria ventriculi (§ 954).

Table of the Systemic Arteries of the Trunk and Arm
(Fig. 101, 102, 105, 107).

A brace placed after an artery includes the branches of that artery.

§ 916. THORAX AND ARM.

r AA. cardiace (§ 856). ;

A. mediastinalis (§ 927).

A. carotidea sinistra (§ 927).

A. carotidea dextra (§ 927).

( A. vertebralis (§ 934).

| A costalis superior (§ 936).

Aorta thoracica (§ 926).. { A. subclavia sinistra (§ 920). 1 ms stern alis (§ 985). pee 38
| Axis thyroideus (§ 937). -

AA. intercostales (10 pairs), (§ 929).

A. bronchialis (2), ($ 930).

A. esophagzea (2-4), (§ 931).

. AA. lumbales (8 pairs), (§ 932).

A. vertebralis (§ 934).

A. costalis superior (§ 936).
A. sternalis (§ 935).

Axis thyroideus (§ 937).

A. brachio-cephalica (§ 927).

A. subclavia dextra (§ 933). (Continuation of the
brachio-cephatica after the origin of the right
GOLOUG,) xa sas wars sie tad doba Avia sag emanate

A thoracica anterior (§ 939).

A. thoracica longa (§ 940).

A. circumflexa posterior (§ 941) et
subscapularis (Fig. 102, § 942).

A. axillaris (§ 938). (Continuation of either A.
subclavia peripherad of the first rib.)......... ..

ae p GG : Sg as A. circumflexa anterior (§ 943, A).
A. brachialis (§ 943), (Continuation of the Axillaris :
peripherad of the origin of the common trunk of “% Olone @ a5, 943, B).
the circumflex and subscapular.)...........+++++ rm nana: Reed ipdanh ($ 943, D).

. radialis recurrens (§ 944, A).

A. radialis (§ 944). (Continuation of the Brachialis | 4- 0/naris recurrens (§ 944, B).

in the antebrachium ; see also § 945.)..........--

ss oO

A
A
A,
A. interosseus anterior (§ 944, D).
A. ulnaris (§ 945).

interosseus posterior ($ 944, C).

344 ANATOMICAL TECHNOLOGY.

$917, ABDOMEN.

( c AA. hepatic
A. cystica,
A. hepatica A. pylorica.
(§ 966, B). | 4 gastro- A. pancreatico-du-
duodenalis, ‘- odenalis,
A. ceeliaca, az. . gastro-epiploica
(§ 966)...... dextra.

A, coronaria ventriculi (§ 966, D).

AA. ventriculi dorsales (§ 966, E).

A. splenica ; AA. gastrice et pancreatice.
(§ 966, F).. ( A. gastro-epiploica dextra.

t A. phrenica ($§ 966, A, 968, B).

Aorta abdominalis ( A. colica media (§ 967, B).
az. (§ 965). (Con- | A. pancreatico-ducdenalis inferior (§ 967, A).
tinuation of the 4 < A colica dextra (§ 967, C).
thoracic aorta, { A. ileo-cecalis ($ 967, D).
Fig+10h).o8s2.. Rami intestini tenuis (§ 967, E).

A. adreno-lumbalis j A. adrenalis (§ 968, A).

A. mesenterica su-
perior, az. (§ 969).

(§ 970). ........ A. phrenica (88 968, B, 966, A).
A, renalis (§ 969)... A, adrenalis.

A. ureterica.
A. spermatica (§ 970).

A. mesenterica in- j A. colica sinistra.
ferior, az. (§ 971). ( A. hemorrhoidalis superior.
A. ilio-lumbalis G 972).
AA. lumbales (§ 974).
A. iliaca externa (§ 978, A).
A. iliaca interna (§ 973, B).
| A. sacra media (§ 973, C).

Preparation—Fig. 101.—A lean cat was killed with chloroform,
and the femoral artery and vein were injected with red and blue
plaster respectively (§§ 352-362). The V. jugularis externa was then
injected cephalad with blue gelatin (§ 366). After an hour the ventral
wall of the entire trunk was removed, together with all the viscera,
except the heart, kidneys and urocystis, and enough of the dia-
phragm to expose the vessels. The liver was cut away within
about 1 cm. of the postcava. All the organs were then freed from
fat and connective tissue with the fine forceps, tracer and scissors.
It was necessary to proceed with great care, especially in separating
the ureter, the spermatic vessels and the vessels into which the
aorta divides.

The urocyst was turned caudad so as to expose its dorsal surface.

Fig. 101, A and B, required no special preparation, as they are
simply enlarged diagrams of the aorta and postcava with their
branches.

erties teammate

345

THE BLOOD VESSELS,

A. ORIGIN OF THE POSTCAVA.

x 3.

.
>

Fig. 101.—GENERAL VIEW OF THE BLOOD VESSELS

B. TERMINATION OF THE ABDOMINAL AORTA.

346 ANATOMICAL TECHNOLOGY.

Description of Fig. 101.—A. V. fem., A. V. femorales—Femoral artery and vein.
A. hypogastrica—The hypogastric or superior vesical artery. A. epigastrica—The deep
or inferior epigastric artery. A. il. ext., A. iliaca externa—The external iliac artery.
A. V. il.-lumb., A. V. ilio-lumbales—The ilio-lumbar artery and vein. A. m. i., A. me-
senterica inferior, az—The inferior mesenteric artery. A. sprm., A. spermatica—The
spermatic artery. Aorta, az. A. renalis—The renal artery. A.m.s., A. mesenterica
superior, az.—The superior mesenteric artery. A. cceliaca, az.—The cceliac artery or
celiac axis. A. brcph., A. brachio-cephalica, az—The brachio-cephalic or innominate
artery. A. subcl., A. subclavia—The subclavian artery. A. strn., A. sternalis—The
sternal or internal mammary artery. A. carotidea—The carotid artery. Adrn., Adrenale
—The adrenal or suprarenal body. Au. dext., Auricula dextra—The right auricle of
the heart. Cardia, az—The heart. Dphrg., Diaphragma, az—The diaphragm. Gl.
sbmx., Glandula submaxillaris—The submaxillary salivary gland. Gl. lym., Glan-
dula lymphatica—A lymphatic gland or pair of glands just cephalad of the submaxillary.
Lrnx., Larynx, az. M. dgst., M. digastricus—Digastric muscle. Precava, az.—
The superior or descending vena cava. Ren—The kidneys. Thyr., Corpus thyroi-
deum—The thyroid body ; the two are connected in man. Urocystis, az.—The urinary
bladder. Urethra, az—The canal leading from the urocystis to the exterior. Ureter
—The canal conveying urine from the kidney to the bladder; see Fig. 85, 86. V.
sprm., V. spermatica—The spermatic vein. V.rn., V. renalis. VV. hepatic (10-12),
az.—Hepatic veins. V. az., V. azygos, az—The azygous vein. V. strn., V. ster-
nalis—The sternal or internal mammary vein. V. sbclv., V. subclavia—The sub-
clavian vein. V. breph., V. brachio-cephalica—The brachio-cephalic or innominate
vein. V. jgl. int., V. jugularis interna—The internal jugular vein. V. jgl. ext., V.
jugularis externa—The external jugular vein. V. jgl. ant., V. jugularis anterior.
V. trns., V. transversa—A large vein connecting the two jugular veins across the
meson. Vagus and Symp.—The vagus and sympathic nerves. Vas deferens—The
canal conveying the semen from the testis.

Description of Fig. 101, A, B.—A. sacra med., A. sacra media, az—The median
sacral artery. A. il. ext., A. iliaca externa. A. il. int., A. iliaca interna. A. hy-
pogastrica—The hypogastric or superior vesical artery. A. epg., A. epigastrica—
The internal or inferior epigastric artery. Aorta, az. A. il.-lumb., A. ilio-lumbalis
—The ilio-lumbar artery. Postcava, az—The ascending or inferior vena cava. V. il.
ext., V. iliaca externa—The external iliac vein. V. il. int., V. iliaca interna—The
internal iliac vein. V. il.-lumb., V. ilio-lumbalis—The ilio-lumbar vein. V. il. com.,
V. iliaca communis.

Fig. 102—Preparation.—The abdominal aorta of an adult cat
was injected with red plaster (§ 352). After an hour the vessels
were carefully isolated in the thorax and in the right arm to the
middle of the antebrachium. This was done by removing muscles,
connective and other tissues with the scalpel, tracer, scissors and
fine forceps. The pericardium was then removed, and the proper
cardiac arteries (AA. cardiacze) were isolated for 1-2 cm. Finally,
the auricles and part of the ventricles were cut away, commencing
peripherad and following the aorta. After the aorta with its semi-
lunar valves was isolated, the entire preparation was soaked in
Wickersheimer’s fluid (§ 300) for a day and then allowed to dry.

THE AORTA, 347

Fic. 102—THe AORTA, WITH ITs MAIN
BRANCHES IN THE THORAX AND RIGHT
ARM ; VENTRAL VIEW; x1. A. ORIGIN
OF THE CAROTID ARTERIES; x1. B,C.
VEINS WITH VALVES ; Quain, A, II, 174.

The Wickersheimer’s fluid prevents the brittleness that is so objec-
tionable in plaster injected vessels that are dried.

B and C—Preparation.—B. A segment of the V. jugularis
externa about 5 cm. long was slit lengthwise and placed in water,
and the valves floated up by blowing into the little pockets with a
blow-pipe.

C. The external jugular or femoral vein was injected peripherad

348 ANATOMICAL TECHNOLOGY.

with plaster, and after the plaster was moderately hard, a hemi-
section of the vessel was made and the plaster removed.

Explanation of Fig. 102.—Arcus aorticus, az.—The arch of the aorta. <A. brcph.,
A. brachio-cephalica, az.—The brachio-cephalic or innominate artery. A. crd. dext.,
A. cardiaca dextra—The right cardiac or coronary artery. A. crd. sin., A. cardiaca
sinistra—The left cardiac or coronary artery. A. mdst., A. mediastinalis, az—The
mediastinal artery, A. sbclv. dext., A. subclavia dextra—The right subclavian artery,
a continuation of the brachio-cephalica. A. carotidea sin. (sinistra)—The left carotid
artery arising from the brachio-cephalica ; see A. A. vertebralis—The vertebral artery.
This arises from the subclavian. A. cstl. (costalis) superior—The superior costal artery.
A. strn., A. sternalis—The sternal or internal mammary artery. A. axillaris—The
axillary artery. A. thr. ant., A. thoracica anterior—The anterior thoracic artery.
A. thr. (thoracica) longa—The long thoracic artery. A. subscapularis—The subscap-
ular artery. A. circumflexa—The circumflex artery ; a common trunk arising from the
axillary bifurcates to form this and the preceding artery; in man they arise separately
from the axillary. A.brachialis—The brachial artery. A. radialis—The radial artery.
A. ulnaris—The ulnar artery. A. interos., A. interosseus—The interosseus artery.
Costa (1)—The first rib in cross section, Fm. eptrch., Foramen epitrochleare. VI.
semilunares—The semilunar valves at the beginning of the aorta ; they are closed.

Explanation of Fig. 102, A.—Aorta, az, A. brceph., A. brachio-cephalica, az.—
The brachio-cephalic artery. A. sbcl., AA. subclavie—The subclavian arteries. A. c.
dext., A. carotidea dextra. A.c. sin., A. carotidea sinistra.

The carotids may arise separately from the brachio-cephalica as shown in Fig. 102, or
less frequently they may arise by the bifurcation of a single trunk which is given off from
the brachio-cephalica (Fig. 102, A). This common trunk is called by Owen (A, III, 535),
the bicarotid, and by Milne-Edwards (A, III, 524), carotide primitive. It is stated by the
latter that this is the normal condition in the cat, lion, dog, ete.

Fig. 102, B.—Vein slit lengthwise and spread out to show two pairs of valves.
Fig. 102, C.—Hemisection of a vein with closed valves.

In both B and C the central end is uppermost. C shows how the two valves pre-
vent the flow of blood or injecting mass toward the periphery. Sometimes but a single
valve exists, in which case the action is less efficient.

§ 918. Posture and Exposure for the Thoracic Vessels.— Place
the cat dorsicumbent, with the arms stretched laterad and fastened
with cords to the loops in the edge of the tray (Fig. 76). If the dis-
section is to be long continued, the caudal half of the body may be
removed (§ 234).

Commence on the right side, and continue the incision made in
exposing the V. jugularis for injection (§ 913) to a point opposite
the base of the xiphisternum, carrying the incision 2 cm. to the
right of the ventrimeson; then, with the arthrotome, cut through
the sterno-mastoid and pectoral muscles (Fig. 72), along a line about
2 cm. to the right of the ventrimeson and parallel with it. Cut

VEINS OF THE THORAX. 349

the thoracic wall on the right side at the junction of the ribs and
their cartilages, and then across the meson (Fig. 76, § 825); do this
with either the arthrotome or bone scissors. Then cut with nippers
the right ribs about 2 cm. from their heads. Turn the sternum to
the left and the wall of the thorax to the right. This will expose
the heart, right lung, preecava, the abdominal part of the postcava,
the right carotid and sternal arteries, and the axillary vessels and
nerves (Fig. 101, 105).

VEINS OF THE THORAX. (See Table, § 914.)

VV. cardiace s. coronariz (see § 887).

§ 919. Frecava, az., and its branches (Fig. 101).—The preecava
is the prominent vessel extending from a point opposite the first
rib to the cephalic part of the right auricle of the heart. It is
noticeable just at the right of the meson.

§ 920. V. azygos, az. (Fig. 99, 101, 107, V. az.).—This enters the
precava just cephalad of the root of the right lung. Grasp the right
lung and turn it toward the left, and with the tracer follow the
V. azygos peripherad. At regular intervals branches from the
intercostal spaces enter it. Those entering it near its termination
are large, as they represent the trunk formed by the union of two
or more intercostal veins. Opposite the 10th rib the vein becomes
mesal in position, and is dorsad of the aorta (Fig. 107, V. az.). The
VY. azygos can not be traced caudad of the diaphragm.

§ 921. V. sternalis (Fig. 101, V. strn., 99, 100).—A bout opposite
the 3d rib the sternal veins enter the preecava as a single trunk, but
on the sternum there are two veins, one on each side just mesad
of the corresponding artery.

§ 922. V. brachio-cephalica s. innominata (Fig. 101, 103, 107,
V..breph.).—If the thymus body is present, separate it from the
precava. About opposite the 1st rib the praecava will be seen to
be formed by the union of two nearly equal branches, the V V. dra-
chio-cephalice. Carefully isolate the right one.

§ 923. V. vertebralis—Very near the 1st rib this large branch
enters the dorsal side of the brachio-cephalica. It comes from the
brain through the vertebrarterial canal in connection with the ver-
tebral artery (Fig. 104, A. vrt.).

§ 924. V.subclavia (Fig. 101).—Just beyond the entrance of

850 ANATOMICAL TECHNOLOGY.

the V. vertebralis the V. brachio-cephalica is formed by the union
of two nearly equal branches, the swbclavian vein and the external
jugular. The V. subclavia may be traced to the arm. Later,
in studying the arteries of the arm, it will be found to follow them
very closely.

§ 925. V.jugularis externa (Fig. 87, 101, 103, A)—This large
vein comes from the head and face. In the neck it is covered only
by the skin and cutaneous muscle. Opposite the cephalic part of
the larynx there is a very large branch connecting the jugulars of
the two sides (Fig. 101, V. trns.).

The external jugular receives the internal jugular (Fig. 101, V.
jgl. int.), the combined trunk of the subcutaneous vein of the arm
and the V. subscapularis. This trunk is shown in Fig. 101 just
cephalad of the abbreviation V. jgl. int.

Veins of the Abdomen, see §§ 946-964.

ARTERIES OF THE THORAX AND ARM. (See Table, § 916.)

§ 926. Aorta thoracica, az. (Fig. 91, 99, 100, 101, 102, 103, 107).
—The aorta is the single great artery arising from the left ventricle
of the heart. Through it and its branches, every part of the body
is supplied with pure blood. To expose it, remove the pericardium
from the ventral wall of the heart, also the preecava, the septum
mediastinale, and the taymus body if that is present. The aorta
curves sharply to the left (Fig. 102), thus making the arcus aorti-
cus. The branches of the thoracic aorta are as follows, commencing
centrad :—

AA. cardiace s. coronarie (see § 856).

§ 927. A. brachio-cephalica s. innominata, az. (Fig, 101, 102,
103, 107).—This arises from the convexity of the aortic arch and
passes almost directly cephalad. Very near its origin it gives rise
to the A. mediastinalis, which passes ventrad, then to the A. ca-
rotidea sinistra (Fig. 101, 102, 102, A, 103, A, C, and 107), and
the A. carotidea dextra. Sometimes the two carotids arise as a
single trunk (Fig. 102, A). After the origin of the carotids, the
A. brachio-cephalica is continued as the A. suwbclavia dextra (§ 933).

§ 928. A. subolavia sinistra (Fig. 101, A. sbclv., 102, 103, A.
sbely. sin., 107, A. s.).—For the branches of the A. subclavia, see
§$ 934-945 and the Table (§ 916).

BRANCHES OF THE A. SUBCLAVIA. 351

§ 929. AA. intercostales (10 pairs), (Fig. 103, AA. costales)—The intercostal arteries
are given off from the dorsal side of the aorta, Each passes to an intercostal space and
divides into three branches. One of these passes ventrad along the caudal margin of the
cephalic of the two ribs between which it extends (Fig. 103); another goes to the deep
muscles of the back, and the third enters the spinal canal through the intervertebral
foramen ; see § 484.

§ 930. A. bronchialis——The arteries (2) to the lungs arise either from the aorta itself,
about opposite the root of the lung, or from the 4th intercostal arteries. They accompany
the bronchi to the lungs.

§ 931. AA, cesophageaze (2-4), (Fig. 107, A. ces.).—These are all small branches and
may sometimes arise from the intercostals instead of the aorta.

§ 932. AA. lumbales (2-3 pairs)—On account of the great caudal projection of the
diaphragm, 2-3 pairs of the lumbar arteries are given off by the thoracic aorta. Rarely
also the A. celiaca arises in the thorax (§ 966).

§ 933. A. subclavia dextra (Fig. 102, A. sbelv. dext.).—This is
a continuation of the A. brachio-cephalica peripherad of the origin
of the right carotid. Tear away carefully any connective tissue cov-
ering it as far peripherad as the ectal margin of the first rib. Note
the large nerve covering its ventral face. This is the vagus (Fig.
107 and 108; the recurrent laryngeal branch may be seen winding
around to its dorsal side (Fig. 108, N. 1. r.).

BRANCHES OF THE A. SUBCLAVIA.

§ 934. A. vertebralis.—This, the first branch, arises from the
cephalic surface of the subclavian and passes dorso-cephalad to
enter the vertebrarterial canal. It passes through this to the brain
(Fig. 102, 103, A. vert., 104, A. vrt.). In Fig. 104, the dorsal wall
of the vertebrarterial canal is removed and the artery shows
throughout nearly its whole extent.

§ 935. A. sternalis s. mammaria interna (Fig. 101, A. strn.,
102, A. strn., 103, 107).—This arises from the ventral surface of the
A, subclavia nearly opposite the origin of the A. vertebralis. It
passes ventrad and reaches the sternum opposite the 2d mesoster-
neber (Fig. 49). It sends two or three small branches cephalad,
then extends caudad along the sternum, and, as stated above, is
laterad of the sternal vein. Branches of this artery anastomose
with the intercostal arteries (§ 929), with the phrenic on the dia-
phragm, and with the epigastric on the abdomen (Fig. 101). The
left sternal also usually supplies the A. pericardiaca to the peri-
cardium.

§ 936. A. intercostalis superior (Fig. 102, A. cstl. superior).—
Just as the subclavian crosses the first rib, this artery arises from

352) ANATOMICAL TECHNOLOGY.

its dorsal surface. It extends only 2-3 mm. before dividing into
two trunks. One extends caudad on the ental wall of the thorax,
supplies the 1st and 2d intercostal spaces, and then passes between
the 1st and 2d ribs to be distributed to the deep muscles of the back.
It may be followed by tearing away the muscles with the tracer.
Its final distribution can best be followed after the removal of the
scapula. The other branch passes cephalad nearly parallel with
the A. vertebralis, and reaches. the dorsal side of the great nerve
trunks of the brachial plexus (Fig. 107). It is distributed to the
M. serratus magnus (§ 664). . After the section of the brachial ves-
sels and nerves and the lateriduction of the scapula, it may be very
easily traced.

§ 937. Axis thyroideus (Fig. 105, A. spscp.)—Just laterad of
the 1st rib, this trunk takes its origin. It passes laterad along the
ental surface of the clavo-trapezius. muscle, sending two or three
branches cephalad, the most important one. being to the longus colli
muscle. The part extending laterad is called the A. swprascapu-
laris. The A. suprascapularis supplies the clavicular end of the
M. clavo-trapezius and the lateral surface of the supraspinatus.
Its principal branch, however, accompanies the suprascapular nerve
between the supraspinatus and subscapularis muscles and enters
the suprascapular fossa about opposite the base of the acromion.
In the supraspinous fossa it divides into two branches, one being
distributed to the muscles in the swpraspinous fossa, while the
other passes through the tnciswra magna (Fig. 45) and is distributed
to the structures in the infraspinous fossa (Fig. 43). The scalpel
as well as the tracer should be used in tracing this vessel.

§ 938. A. axillaris (Fig. 105, A. axl.).—This is the continuation
of the A. subclavia laterad of the 1st rib. It is very intimately
associated with the axillary veins and nerves.

§ 939. A.thoracica anterior (Fig. 102 and 105, A. thr. ant.).—
This is the first branch furnished by the A. axillaris. It arises from
the ventral surface of the axillary and passes with the nerve of the
same name (Fig. 105) ventrad to the pectoral muscles. If the pecto-
rals were divided at the proper level, this artery would remain with
the arm.

§ 940. A. thoracica longa (Fig. 102 and 105, A. thr. longa).—
It arises at about the same level as the preceding (§ 939) and passes
nearly caudad, sending several small branches to the pectorals, but

ARTERIES OF THE THORAX AND ARM. 353

is distributed principally to the ental surface of the I. latissi-
mus (§ 635).

§ 941. A. circumflexa (Fig. 102, 105, A. crem).—After the A.
thoracica longa has been traced, cut through the pectoral mass and
the M. epitrochlearis (§ 681) along the caudal edge of the I. biceps,
that is, nearly parallel with the humerus. Turn the muscles aside,
and there will be exposed the vessels and nerves of the brachium.
About opposite the trochin (Fig. 45, B) the axillary artery will be
found to divide into two slightly unequal parts (Fig. 102, 105). The
larger of these, the brachial artery, continues along the arm; the
other, the common trunk of the circwmflex and subscapular arteries,
proceeds toward the surgical neck of the humerus for about 1 cm.,
when it divides into the branches just named.

The circumflex passes between the subscapularis and teres mus-
cles in company with the circumflex nerve (Fig. 105) ; it winds dor-
sally around the surgical neck of the humerus and is distributed to
the triceps muscles, and its terminal branches pass to the ental
aspect of the JZ. clavo-deltoideus. Demonstrate these by separating
the acromio- and clavo-deltoid muscles and raising the cephalic bor-
der of the latter. Branches of the circumflex artery and nerve will
be seen ramifying on its ental aspect.

§ 942. A. subscapularis (Fig. 102, 105, A. sbscp.).—This arises
in common with the circumflex, as stated above (§ 941); it passes
somewhat laterad and is distributed principally to the structures in
the subscapular fossa (Fig. 44). Several branches are furnished,
however, to other structures, viz., WM. latissimus, meditriceps and
dermo-humeralis. This artery and its branches are best followed
after section of the axillary vessels and nerves.

§ 943. A. brachialis (Fig. 102, 105, A. br.).—This is the artery
of the brachium. It is a direct continuation of the A. axillaris per-
ipherad of the origin of the common trunk of the circumflex and
subscapular (S$ 941-2). Isolate it with the tracer by tearing away
connective tissue. The median nerve and brachial vein lie ectad
of it and should be removed or turned aside. In its course along
the caudal side of the arm, the brachial gives rise to several un-
named muscular branches and the following named branches :—

(A) A. circumfiexa anterior (Fig. 105. It is the small vessel passing between s and p
of “ NV. m. spiralis”’).—It passes to the caudal margin of the M. biceps, and then sends a
branch proximad to the head of the humerus.

23

354 : ANATOMICAL TECHNOLOGY.

(B) A. profunda superior (Fig. 105)—This arises opposite the musculo-spiral nerve
(Fig. 105) and follows its course.

(C) A. nutriens.—In Fig. 105 it is the vessel passing between the A.and the br. It is
represented too large. It passes to the bone, and entering the nutrient foramen, is distrib-
uted to the shaft of the humerus.

(D) A. anastomotica magna (Fig. 105, between the abbreviations Amr. and tre., near
the distal end of the humerus).—This artery passes to the convexity of the elbow.

Upon reaching the foramen epitrochleare, the A. brachialis traverses it in company
with the median nerve (Fig. 102, 105) and reaches the concavity of the elbow.

§ 944. A. radialis (Fig. 102, 105).—The brachial artery distad
of the concavity of the elbow is continued as the radial. It passes
caudad of the tendon of the diceps muscle and entad of the prona-
tor teres (Fig. 105, § 701). About opposite the middle of the ante-
brachium the radial artery is covered only by skin and fascia. At
this point the artery divides into two unequal branches ; the smaller
or ventral one follows the radial nerve, while the principal one in-
clines dorsad, and just distad of the styloid process of the radius it
curves around to the dorsal side of the manus.

To expose the artery, divide the I. pronator teres about 2 cm.
from its origin and turn the two ends aside, and divide longitudi-
nally the antebrachial fascia along its ventral aspect.

The radial artery gives rise to several muscular branches that
are unnamed and to the following named branches :—

(A) A. radialis recurrens.—This arises in the concavity of the elbow on the caudal
side of the tendon of the biceps (Fig. 105). It is distributed to the various structures in
the concavity of the elbow.

(B) A. ulnaris recurrens (Fig. 105).—This is shown in the figure as arising from the
radial opposite the point where it crosses the M. biceps. It extends proximad to the struc-
tures at the convexity of the elbow. It is called wnar recurrens on account of its distri-
bution. See Quain, A, I, 408, and Gray, A, 520.

(C) A. interosseus posterior.—This artery arises from the ental aspect of the radial
just distad of the tendon of the biceps. It extends nearly directly dorsad, and may be
demonstrated by tearing away the muscles surrounding it.

(D) A. interosseus anterior (Fig. 105, A. interosseus).—This artery arises, either sep-
arately or as a common trunk with the ulnar, from the ental aspect of the radial about
3 cm. from the Fm. epitrochleare. It passes distad along the antebrachium on the ventral
side of the interosseus ligament. It may easily be followed by turning the radial artery
slightly aside and then separating the muscles with the tracer.

§ 945. A. ulnmaris (Fig. 102 and 105).—In man the ulnar artery
is about equal in size to the radial, and the division of the brachial
to form them is very near the elbow or even in the brachium (Quain,
A, I, 403); but in the cat the ulnar is so small that it is sometimes
not injected at all with plaster. Inits course and distribution it cor-

ABDOMINAL BLOOD VESSELS. 355

responds, however, with its human homologue. It arises from the
radial at about the junction of the proximal and middle thirds of
the antebrachium, and is covered at its origin by the JZ pronator
teres (§'701). It passes caudad and distad along the ental surface
of the flexor muscles, and joins the ulnar nerve at about the point
of its division into a dorsal and ventral branch. The artery divides
at this point, and the two branches accompany the two branches of
the ulnar nerve.

ABDOMINAL BLOOD VESSELS.

Posture.—Dorsicumbent, the limbs fastened laterad with cords
(Fig. 76).

§ 946. Preparation.—The arteries and veins should be injected
with plaster as directed above (§§ 352-362), or the thorax may be
opened and the thoracic aorta and postcava injected caudad; the
latter is easier done if the thorax is to be studied on a different cat.

§ 947. Exposure.—About half an hour after the injection is
finished, open the abdomen as directed for the exposure of the
viscera (§ 710).

VENA PorTa&. (See Table, § 915.)

The study of the portal vessels will be greatly facilitated by injecting them. To do
this, turn the duodenum to the left, and extending along the mesoduodenum (§ 726), near
the edge of the duodenal part of the pancreas, will be seen a large vessel filled with blood
(V. mesenterica superior). Inject this vessel toward the liver, inserting the canula about
opposite the caudal end of the pancreas. Employ uncolored plaster or that colored with
chrome green or yellow. All the larger portal vessels will be filled except the peripheral
part of the V. mesenterica superior, and that may be filled by reversing the direction of
the canula

It will be necessary to change the position of the viscera often in
tracing the portal vessels.

- § 948. V. mesenterica superior, az. (Fig. 103, 107, V. m. s.).—
This collects the blood from the small intestine. Trace it from the
point where it was injected, first peripherad along the small intes-
tine, and then centrad to a point opposite the pylorus.

§ 949. V. mesenterica inferior, az. (Fig. 107).—This usually empties into the pre-
ceding about opposite the ampulla of Vater (Fig. 84), or it may empty into the following,
asin man. It comes from the large intestine.

§ 950. V. gastro-splenica, az.—This joins the portal slightly nearer the liver than the
preceding (§ 950).—It comes from the spleen, from part of the stomach and from the gastro-

356 ANATOMICAL TECHNOLOGY.

splenic part of the pancreas. Trace it to these parts. It may also receive the vessels
mentioned in §§ 949, 950.

§ 951. V. porte, az.—The trunk formed near the pylorus by the
VV. mesenterice and the V. gastro-splenica is called the Vena
porte. It passes to the liver parallel with the ductus choledochus
communis (§ 746 [3]), and receives the following branches when
they do not empty into any of the preceding :—

§ 952. V. pancreatico-duodenalis, az—Coming from the pancreas and the duode-
num. This vessel empties into the V. porte on the dorso-dextral side of the pylorus.

§ 953. V. gastro-epiploica. az.—This comes from the pyloric part of the great curva-
ture of the stomach and the dorsal fold of the great omentum. It empties into the V-
porte opposite the pylorus.

§ 954. V. coronaria ventriculi, az,—As the name indicates, this comes from the lesser
curvature of the stomach. It empties into the V. porte somewhat nearer the liver than
the preceding. The three branches just described may all unite to form a single trunk
before emptying into the V. porte.

SysTEMIC ABDOMINAL VEINS. (See Table, § 915)

§ 955. Postcava s. Vena cava inferior, az. (see Table, § 915,
Fig. 101, 103, Postev., 107, Pev.).—Turn the stomach and intestines
to the left. The postcava, filled with blue plaster, will appear ex-
tending somewhat obliquely caudo-sinistrad along the meson. Just
cephalad of the right kidney it penetrates the liver and is entirely
surrounded by its substance. Opposite the last lumbar vertebra
the vessel usually becomes entirely mesal in position and reaches
the dorsal side of the aorta (Fig. 101). The vessel may divide oppo-
site the kidneys into two nearly equal branches, which extend
caudad, one on each side of the meson.

§ 956. V. phrenica (Fig. 90).—These pass mesad along the opposite halves of the dia-
phragm, and open into the postcava just as it penetrates the diaphragm. Draw the liver
somewhat caudad, and the vein may be easily demonstrated with the tracer.

§ 957. VV. hepatice, az. (10-12), (Fig. 101).—These convey the blood supplied to the
liver by the V. porte and the A. hepatica into the postcava. They may be demonstrated
by tearing away the liver substance next the postcava. Their number is variable, as the
lobes sometimes give off more than one branch each.

§ 958. V. adreno-lumbalis (Fig. 101, 103, 107)—This vein returns blood from the
adrenal (§ 760), from the M. psoas and the dorso-lateral parietes of the abdomen opposite
the kidney. It opens into the postcava just caudad of the liver, or it may empty into the

V. renalis (§ 959). To demonstrate it, turn the stomach and intestines aside, and employ
the tracer. The vein usually rests in a groove on the ventral side of the adrenal (Fig. 101).

§ 959. V. renalis (Fig. 101, V. rn, 103, V. rn., 107, V. rn.).—This
extends in nearly a straight line from the kidney and empties into the

DIVISIONS OF THE POSTCAVA. 357

side of the postcava. The left is slightly cephalad of the right, and
both veins usually lie caudad of the corresponding arteries (Fig. 108).
The left renal vein usually receives the V. spermatica and nearly
always contains a pair of valves just centrad of the entrance of the
V. spermatica. The right may also contain valves, but it rarely
receives the V. spermatica deatra. Both often receive the V. adreno-
lumbalis. The V. renalis, like the A. renalis, may be double (§ 969).
Finally, when the postcava is divided sufficiently far cephalad
(§ 962), the V. renalis may empty into the corresponding division
instead of into the postcaval trunk.

§ 960. V. spermatica (male), ovarii (female), (Fig. 101)—The left opens almost inva-
riably into the left renal (§ 959), while the right nearly always empties directly into the
postcava. Both are guarded by a pair of valves about 5 mm. from their mouth.

The V. spermatica returns blood from the testis, and hence passes nearly longitudinally
cephalad through the inguinal ring (§ 768) to the point where it empties. It is very slen-
der and must be traced with great care. The V. ovarit is much shorter, passes obliquely
- laterad from the ovary, and increases greatly in size during gestation.

§ 961. V. ilio-lumbalis (Fig. 101)—This enters the postcava at right angles nearly
opposite the Crista iii (Fig. 51). It returns blood from the free or ventral surface of the
muscles in this region. 2

Divisions of the Postcava.—Usually the postcava is a single
median vessel until it reaches a point opposite the junction of the
6th and 7th lumbar vertebree. Here it lies between the aorta and
the spinal column; hence the aorta should be removed. But this
part of the dissection should be deferred until the arteries have
been studied (§ 965).

§ 962. Branches :—V. iliaca communis (Fig. 101, A).—The post-
cava in the cat is formed by two equal trunks opposite the junction
of the 6th and 7th lumbar vertebree. Each trunk is one of the com-
mon iliac veins. Sometimes (once in about ten cases) the postcava
divides into the common iliacs much farther cephalad, rarely even
cephalad of the kidneys. In such cases the postcava is on the ven-
tral or lateral aspect of the aorta, never on its dorsal side.

§ 963. V. iliaca externa (Fig. 101).—This large vessel comes
from the leg, passing into the abdomen dorsad of Poupart’s liga-
ment (Fig. 39). It unites with the following (§ 964) to form the V.
iliaca communis. The vein should be traced peripherad upon the
meros. Just as it enters the abdomen there is a pair of valves that
usually stop the plaster injection completely. The valves may be
easily demonstrated by slitting the vein longitudinally and then
blowing peripherad with the blow-pipe (Fig. 102, B, C,§ 130). This

358 ANATOMICAL TECHNOLOGY.

demonstration will be especially satisfactory if the vein is immersed
in water. ;

§ 964. V. iliaca interna (Fig. 101, A).—This returns blood from
the pelvis, the hip and the thigh, ete. The main trunk of this vein
is formed by branches within the body cavity. It unites with the
preceding to form the V. éliaca communis. The branches of this
trunk are so well supplied with valves that they are rarely injected
with plaster.

AorTA ABDOMINALIS. (Fig. 101, 108, 107 ; see Table, § 917.)

§ 965. Turn the stomach and intestines to the right, press upon
the median line against the spinal column, and the injected aorta

will be felt. It may be exposed by tearing away the peritoneum.

with a tracer. Commence ata point just caudad of the diaphragm,
expose the aorta, and note the following branches and their anas-
tomoses :—

§ 966. A cceliaca—Cceliac axis, az. (Fig. 101, 103, 107).—As the
aorta enters the abdomen—sometimes just before—there is given off
a large trunk, the celiac axis, which extends nearly ventrad. Tear

‘away the peritoneum and connective tissue covering the vessel, and
note the following branches and their distribution :— {

(A) A. phrenica s. A. diaphragmatica.—This artery is some-
times given off from the cephalic side of the cceliac axis near its
origin from the aorta. More frequently it arises from the A. adre-
no-lumbalis (§ 968). It soon divides into two branches and is
distributed to the diaphragm.

(B) A. hepatica, az.—Turn the liver cephalad and draw the .

stomach sinistro-caudad. Tear away with the tracer the peritoneum
from the lesser curvature of the stomach, and the celiac azis will
appear. <A large branch—A. hepatica—will be seen arising from the
celiac axis, and extending dextro-ventrad toward the liver. Trace
it by tearing away the peritoneum and connective tissue with the
tracer. Nearly opposite the pylorus it divides into three trunks :—

(a) A. hepatica, continuing to the liver and sending branches to each of the lobes.

(b) A. cystica, to the cholecyst (Fig. 79).

(c). A. gastro-duodenalis.—This is on the dorsal side of the pylorus. It furnishes three
named branches :—

(1) A. pylorica, extending from about opposite the pylorus along the lesser curvature
of the stomach, and finally anastomosing with the A. coronaria ventriculi. The A. pylor-
ica sometimes arises directly from the A. hepatica, as in man.

(2) A. gastro-epiploica deatra.—This, like the preceding and following, passes dorsad

tt essere

BRANCHES OF THE AORTA ABDOMINALIS. 359

of the pylorus ; then it extends along the greater curvature of the stomach in the ventral
fold of the great omentum near its attachment to the stomach. It anastomoses with a
branch from the spleen (gastro-epiploica sinistra ?)

(3) A. paecreatico-duodenalis superior.—This passes along the dorsal side of the pylo-
rus, then to the left of the duodenum. It finally anastomoses with the pancreatico-duode-
nalis inferior (Fig. 81).

(D) A. coronaria ventriculi, az.—This branch arises from the cceliac axis only slightly
peripherad of the A. hepatica, and is distributed to the lesser. curvature of the stomach.
One of its larger branches anastomoses with the A. pylorica (§ 966, [1]).

(E) AA. ventriculi dorsales (Chauveau, A, 559).—There are usually two of these.
They pass directly to the dorso-sinistral part of the stomach. Their homology is doubtful.

(F) A. splenica, az.—This is the largest branch of the cceliac axis, and seems to be a
continuation of it. It passes to the spleen, but before reaching that organ divides into
two nearly equal branches, one going to each extremity.

The spleen is sometimes double, and in such a case each part is supplied by one of the
branches just mentioned.

Numerous small branches pass from the A. splenica to the pancreas and to the stomach.
One branch passes dextrad in the ventral fold of the great omentum to anastomose with
the A. gastro-epiploica dextra (§ 966, [2]). This may be the homologue of the A. gastro-
epiploica sinistra of man. It is small, and only rarely is the anastomosis shown with the
ordinary plaster injection. In fresh specimens the artery will contain sufficient blood to
enable one to trace it. It is of course easily filled with a fine injecting mass (§ 1450)

§ 967. A. mesenterica superior—Superior mesenteric artery, az.
(Fig. 101, 103, 107).—Turn the stomach and intestines to the right.
The artery arises about 2 cm. caudad of the A. ceeliaca. Expose it
fully by tearing away the peritoneum and nerves covering it. Use
the tracer, and the scissors occasionally if necessary. Observe the
following branches and their connections and distribution :—

(A) A. pancreatico-duodenalis inferior (Fig 81 [10]).—This passes obliquely cephalad
to the duodenal pancreas and anastomoses with the A. pancreatico-duodenalis superior.

(B) A. colica media—This branch is of considerable size. It passes to the large
intestine and sends branches cephalad and caudad. The cephalic branch anastomoses
with the A. colica dextra (C) or, if that is absent, with the A. ileo-colica. The caudal
branch anastomoses with the A. colica sinistra (§ 971, A).

(C) A. colica dextra.—This is often absent in the cat. When present it passes to
the large intestine, and anastomoses with both (B) and (D).

(D) A. ileo-colica.—This is a large branch, extending directly to the cecum. It sends
branches caudad to the large intestine, where they anastomose with (B) or (C), and others
cephalad to the ileum, where they anastomose with the Rami intestini tenuis.

(E) Rami intestini tenuis.—These are the branches into which the A. mesenterica
superior finally breaks up, and, as the name indicates, they are distributed to the small
intestine. ,

§ 968. A. adreno-lumbalis (Fig. 101, 103, 107).—This artery arises from the side of
the aorta, just caudad of the origin of the A. mesenterica superior (§ 967). It passes
directly laterad, giving off the following branches: (A) the A. adrenalis to the adrenal,
and (B) the A. phrenica to the diaphragm. The artery rests on the free or ventral surface

360 ANATOMICAL TECHNOLOGY. -

of the M. psoas ; it is, however, partly covered by the adrenal ard the ceplalic end of the
kidney. It will be necessary to remove the fat and connective tissue with great care from
the adrenal and phrenic arteries, and it may be desirable to use the forceps and scissors to
remove tough connective tissue and nerves. As was stated above, the A. phrenica may be
supplied by the coeliac axis (§ 966). The left A. adreno-lumbalis much more often sup-
plies an A. phrenica than the right. The left and its branches are more easily demon-
strated than the right.

§ 969. A. renalis (Fig. 101, 103, 107).—The renal artery arises
from the side of the aorta like the preceding, and passes nearly lat-
erad to enter the hilum of the kidney. It usually gives from its
ventral surface a small branch to the adrenal, and often one to the
ureter. The renal artery is covered on its ventral surface by the
V. renalis ; hence, to obtain a good view of the artery, the vein
must be removed or drawn aside. Employ the tracer, working care-
fully in order that the branches named above may not be broken.

The A. renalis usually divides into two nearly equal branches
about 1 cm. from the kidney, and one branch goes to each side of
the renal pelvis ; it is sometimes double (Fig. 103).

§ 970. A. spermatica (male), ovarii (female), (Fig. 101)—This arises from the ven-
tral surface of the aorta 1-2 cm. caudad of the A. renalis. It passes somewhat obliquely

caudad, supplying the ovary in the female and forming part of the spermatic cord in
the male.

Expose it by turning the intestines to the right; then very carefully tear away the
peritoneum covering the aorta. As the artery is only about 1 mm. in diameter, great care
is necessary in the dissection ; probably it will be necessary to employ the forceps and
scissors as well as the tracer. In the female the artery is much convoluted ; see § 960.

§ 971. A. mesenterica inferior, az. (Fig. 101, 103, 107).—The
artery arises from the ventral surface of the aorta about opposite
the iliac crest (Fig. 51). It passes nearly ventrad.

Turn the large intestine to the right, and with the tracer follow
it. Near the large intestine it divides into two branches :—

(A) A. colica sinistra, which extends cephalad along the large
intestine and anastomoses with the A. colica media (§ 967, B).

(B) A. hemorrhoidalis superior. This passes caudad along the
large intestine and anastomoses with the hemorrhoidalis media from
the A. iliaca interna.

§ 972. A. ilio-lumbalis (Fig. 101).—This artery arises from the side of the aorta
slightly caudad of the origin of the preceding (§ 971), and passes laterad over the ventral
wall of the M. psoas, and to other muscles over and near the I/ium. It is comparable
with the A. adreno-lumbalis (§ 968). To demonstrate it, turn the large intestine to the right,
and tear away the peritoneum with a tracer. As it is the only artery passing laterad in
this region, it cannot be mistaken.

a

ILIAC ARTERIES. 361

§ 973. Divisions cf the Aorta abdominalis (Fig. 101, B).— Hxpo-
sure and Dissection.—Draw the urocystis (Fig. 101) caudo-ven-
trad ; press the contents of the rectum cephalad ; doubly ligate and
cut it opposite the neck of the urocystis. Cut the mesocolon
(§ 726) and mesentery near their attachment to the intestine as far
cephalad as the duodenum ; then cut the small intestine at the cau-
dal end of the duodenum, and throw the intestines away. If the
remaining part of the rectum is washed out with a solution of ferric
sulphate (copperas) by introducing the canula of the syringe into
the anus, the unpleasant odor will be avoided. If the urocystis
contains urine, it should be pressed out through the urethra, or a
slit may be cut in it.

In demonstrating the vessels, employ the forceps and tracer
mostly; but use the scissors when it is necessary to remove any
tough masses.

(A) A. iliaca externa (Fig. 101, B).—This passes obliquely cau-
dad, penetrates the abdominal wall dorsad of Poupart s ligament,
‘and reaches the cephalic side of the meros where it is called the
femoral artery. Just before the A. iliaca externa leaves the abdo-
men, it gives off a large branch from its mesal aspect. This branch
supplies the A. epigastrica (Fig. 101), then penetrates the abdomen
near the symphysis pubis, and sends branches to the skin in the
pubic region, but is mainly distributed to the muscles on the ce-
phalic and ventral aspects of the proximal end of the meros. The
human homologue of this artery has not yet been satisfactorily
determined.

(B) A. iliaca interna (Fig. 101, B).—This arises from the aorta
about 1 cm. caudad of the origin of the preceding. It passes
obliquely caudad within the pelvis and dorsad of the pubis. A
short distance from its origin the A. vesicalis superior (Fig. 101)
is given off from its ventral surface. This small vessel is the rem-
nant of the A. hypogastrica of the foetus. It occasionally arises
from the aorta.

The A. iliaca interna supplies most of the pelvic viscera entirely and furnishes part
of the blood supply to the innominate and meral regions.

(C) A. sacra media, az. (Fig. 101, B).—The aorta is continued to the tail by this small
mesal artery, which passes through the arches formed by the chevron bones (§ 465).

It will be seen by comparing the figure of the cat with that of man (Quain, A, I, 281,
Gray, A, 824), that in the cat there is no common iliac as in man, but each iliac is a
branch of the aorta.

362 ANATOMICAL TECHNOLOGY.

§ 974. AA. lumbales (6 pairs)—The lumbar arteries arise from the dorsal side of the
aorta opposite the intervertebral fibro-cartilages. They extend directly dorsad for a short
distance, and then turn laterad to be distributed to the ental or attached surface of the
muscles on the ventral and lateral aspects of the spinal column, A small branch usually
enters the intervertebral foramen to supply the myelon.

§ 975. Demonstration of the AA. lumbales.—Turn the stomach
to the right, cut the left renal vessels and remove the left kidney
and the left half of the diaphragm. Draw the aorta dextrad.
Commence opposite the last rib, and with the forceps and tracer
clear away the fat and connective tissue on the dorsal and sinistral
aspects of the aorta. From the great caudal projection of the dor-
sal part of the diaphragm, the Ist, 2d, and sometimes 3d, pairs of
AA. lumbales are given off within the thorax; hence the necessity
of removing the diaphragm. The last pair is given off by the aorta
just caudad of the origin of the A. iliaca externa. Tear and cut
away carefully the muscles and connective tissue, and trace the 2d
or 8d A. lumbalis and its distribution as described above (§ 974).

STRUCTURE OF THE HEART AND BLOOD VESSELS.

§ 976. Obvious Structure of the Heart.—(A) The heart is covered by a serous mem-
brane—the ental (inner) layer of the pericardium (§ 910).

(B) Its main substance is composed of muscle, apparently but not really like the ordi-
nary voluntary muscles. Compare $§ 704 and 705.

The arrangement of muscular fasciculi in the auricles seems to be comparatively simple,
namely, in two layers, of which the ectal have a circular and the ental a longitudinal
direction (Stricker, A, 183). But in the ventricular walls the arrangement is very complex
(Quain, A, I, Fig. 179). According to Pettigrew (A, 194), there are no less than seven
more or less distinct layers, the fibers of which vary in direction from nearly circular to
nearly longitudinal, with several degrees of obliquity. The author just named recom-
mends (p. 193, note 2) that for the study of the layers, the cavities should be filled with
bran and the organ then boiled for from 4-10 hours, according to size, and kept in alcohol
for a fortnight before dissecting.

(C) The cavities (Fig. 92) are lined by a firm serous membrane—the endocardium.

(D) Valves and chorde tendinew ($§ 864, 881-884).

§ 977. Microscopic Structure.—(A) The serous covering and lining of the heart has
the structure belonging to serous membranes generally (§ 730).

(B) ‘‘The muscular fibers of the heart differ remarkably from those of involuntary
muscular organs in general, inasmuch as they present transverse striw. The strie, how-
ever, are less strongly marked and less regular, and the fibers are smaller in diameter than
in the voluntary muscles (§ 705). They differ also from these in being made up of guad-
rangular cells joined end -to end, and often presenting a branched or forked appearance
near one extremity. Each cell has commonly a single clear oval nucleus situated near
the center ; occasionally two nuclei are seen. The cell substance is faintly striated lon-
gitudinally as well as transversely ; it presents no indication of an investing membrane or
sarcolemma, As stated by Stricker, however (A, 182) the ‘cells of muscles, like all other

THORACIC DUCTS. 363

naked cells, must present a peripheral investment ;’ that is, like all cells which form
part of a complex, compact structure, and do not simply float free in a liquid as do the
leucocytes in the blood. The muscular fibers of the heart freely divide and anastomose,
the junction with neighboring fibers being effected by the medium of the cell-offsets
above noticed.” Stricker, A, 179; Quain, A, II, 119, 240, 261.

§ 978. Arterie.—Their obvious structure is that of smooth-bored, thick-walled tubes
which retain their form when cut. They are elastic and flexible.

§ 979. Microscopie Siructure—They are composed of three well-defined coats :—(A)
Ectal or outside coat, tunica adventitia, of rather loose elastic and white connective tissue,
with a general longitudinal direction. (B) Intermediate or middle coat, composed of elas-
tic and white connective tissue and circularly arranged muscular fibers. (C) Ental or
inner coat, composed of elastic tissue covered by endothelium on its free surface.

§ 980. Muscular and Elastie Types of Arteries—Ranvier and others have divided the
arteries into the two classes just named, from the preponderance of elastic tissue or of mus-
cular fibers in the middle coat. The larger arteries, like the carotids, the axillary and the
aorta, contain very little muscular tissue, and hence they belong to the elastic type. The
arteries of the limbs and the smaller arteries generally contain a large amount of muscu-
lar tissue in their middle coat, and hence represent the muscular type.

§ 981. Venz.—The obvious structure of these is the same as that of the arteries, but
the walls are thin, so that they collapse when cut.

$ 982. Microscopie Structure.—There are three coats as with the arteries. The white
connective tissue is more abundant in the middle coat. Smooth muscle is often present in
the ectal coat of some large veins, like the Vena cava, while it is entirely wanting in
others, as in most of those of the brain and pia mater ; Quain, A, II, 173.

§ 983. Capillaries.—*“ The wall of the capillaries proper is formed entirely of a simple
epithelioid layer, composed of flattened lanceolate cells joined edge to edge, and continuous
* with the corresponding layer which lines the arteries and veins.” Quain, A, II, 177.

§ 984. The structure of the lymphatic vessels very closely resembles that of the blood
vessels. Quain, A, II, 186.

THORACIC DUCTS AND LYMPHATIC VESSELS.

References.—Quain, A, I, 504: Gray, A, 589; Cuvier, A, VI, 60; Gegenbaur (Lan-
kester), A, 599; Hyrtl, A, 750; Bernard, A, 253; Leyh, A, 656; Owen, A, III, 511;
Milne-Edwards, A, IV, 503 ; Chauveau, A, 675; Chauveau (Fleming), A, 634; Gurit,
A, 681. ’

Instruments and materials the same as for the blood vessels
(§ 912).

§ 985. Specimen, Preparation, Posture and Dissection.—Em-
ploy a young, but especially a lean cat. Two hours before death
feed it 200 ec. of milk mixed with a beaten egg. Kill with chloro-
form (§ 189). Inject the right V. jugularis externa with fine mass
as for the blood vessels (§§ 366 and 1450), and either the femoral
artery or the aorta just caudad of the origin of the A. mesenterica
inferior (Fig. 39, 101, § 352). In case the venous system is not filled
with fine mass, the cephalic part of the preecava should be closed

364 ANATOMICAL TECHNOLOGY.

by a ligature or compressor (Fig. 13), and the dissection may com-
mence fifteen minutes after the injection with plaster ; or if injected
with fine mass, after an hour open the abdomen as for the abdomi-
nal viscera (§ 710), and the thorax as for the blood vessels (§ 918),
except that the left side should be cut as well as the right, and the
longitudinal incisions should be carried caudad till they reach the
free edge of the abdominal flaps. The diaphragm should be cut
next the ventral wall, and the ventral wall removed with great care
so as to avoid wounding the veins or arteries. With nippers (Fig.
11), carefully cut the left ribs, except the first, about 2 cm. from
their heads. Turn the free edge of the thoracic wall to the left.

§ 986. Vasa chylifera, Lacteals—Turn the omentum majus
cephalad and lift the intestines. Look at the mesentery, and the
lacteal vessels will be seen as whitish or yellowish lines extending
dorsad from the intestine and nearly parallel with the blood ves-
sels. Draw the large intestine caudad, and there will be seen a
very large lacteal trunk extending dorso-cephalad from the large
mesenteric gland (§$§ 731, 992, B).

Dorsad of the cecum this vessel crosses obliquely the superior
mesenteric vein (Fig. 103, V. m. s.), and extends dorsad nearly
parallel with the superior mesenteric artery (Fig. 103, A. m. s.).

Attempt to force the contained chyle toward the periphery, and the . .

beaded appearance shown in Fig. 103 will result. This is due to
the valves, which are similar in form and function to those in the
veins (Fig. 102, B. c., § 963).

§ 987. Receptaculum chyli, az. (Fig. 103).—This is a fusiform
enlargement at the caudal end of the left thoracic duct, into which
empty the lacteals or vasa chylifera from the alimentary canal, and

_the lymphatics from the caudal half of the body (§ 992).

Ezposure.—Cut the peritoneum along the abdominal wall from
the caudal end of the kidney to the diaphragm. Reflect the peri-
toneum and kidney mesad, and the receptaculum will appear as
a fusiform yellowish sac on the dorso-sinistral side of the aorta,
extending from a point about opposite the hilum of the kidney to
the hiatus aorticus in the diaphragm (Fig. 90).

§ 988. Ductus thoracicus sinister (Fig. 103)—The left thoracic
duct is the common trunk which receives the lymphatics of the
entire caudal half of the body, including those of the alimentary
canal—the lacteals or vasa chylifera—and those of the left side of
the head, face, neck and thorax. It pours its contents—lymph or,

THE RIGHT THORACIC DUCT. 565

during digestion, mixed lymph and chyle—into the V. jugularis
externa.

The duct almost invariably divides into two or more trunks near
the middle of its course. After extending for a few centimeters as a
double or triple duct, it may unite and then divide again before
emptying into the vein (Fig. 103). See Colin, A, article Thoracic
Duct, for variations in the domestic animals.

§ 989. Dissection.—Slit the diaphragm ventrad from the hiatus
aorticus (Fig. 90), and turn the two crura or pillars of the dia-
phragm aside as shown in Fig. 103, Crus dphrg. Turn the heart
and lungs to the right, and, if the cat is lean, the thoracic duct will
be seen on the dorso-sinistral side of the aorta, as a continuation
cephalad of the receptaculum (Fig. 103). Cephalad of the heart it
rests on the ventral aspect of the A. swbclavia sinistra. Tt finally
crosses the V. brachio-cephalica sinistra and, receiving the vasa
lymphatica from the head and neck, empties into the V. jugu-
laris externa near the angle of union of that vessel with the V.
subclavia. As a rule, however, the thoracic duct opens into the
vein in two places, as shown in Fig. 103. Both branches of the
divided thoracic duct may receive a lymphatic vessel from the head
and neck. In isolating the duct, it is necessary to proceed with
great care. The tracer must be employed sparingly. The pleura
and connective tissue are most safely removed piecemeal with scis-
sors and fine forceps, as directed for exposing the nerves and sali-
vary glands of the face (§ 777). It is especially difficult to isolate
the duct in its cephalic third, as it is usually double or triple, and
each part therefore correspondingly small (Fig. 103, A).

The first rib must now be carefully cut and removed. The
largest of the vasa lymphatica in the neck rests on the longus colli
muscle entad of and parallel with the carotid artery.

§ 990. Ductus thoracicus dexter.—The right thoracic duct or
great lymphatic vein is the large lymphatic trunk into which empty
the vasa lymphatica of the right side, of the thorax, of the head and
of the neck. It opens into the right V. yugularis externa in the
same way as the left empties into the left V. yugularis externa.

§ 991. Exposure and Dissection.—_Employ the same specimen
that was used for the left duct, make an incision on the right along
the neck, and expose the V. jugularis externa to its junction with
the V. subclavia. Do this very carefully. The vasa chylifera will
be seen dorsad of the aorta, and entering the veins as described after

366 ANATOMICAL TECHNOLOGY.

Fig. 103.—THE Lert THoractc Duct, SINISTRAL Virw; x.5. A. TERMINATION OF
THE THorAcic Duct; x3.

THORACIC DUCTS. 367

uniting with the duct from the thorax. The lymph in these vessels
will be pale, and hence they must be looked for with care. They
may usually be recognized from their characteristic moniliform
appearance (Fig. 103); they may be injected (§ 992, A).

LYMPHATIC VESSELS.

The lymphatics, like the veins, contain many valves, making it impossible to inject
from a large trunk peripherad, as with the arteries. The vessels may be filled, however,
by the puncture method of Ludwig, which consists simply in thrusting a sharp pointed
canula into the tissues and forcing Berlin blue through the canula with a syringe.

§ 992. Lymphatics of the Arms and Legs.—T'o inject these
prepare a glass canula (Fig. 32), leaving the point sharp. Fill the
syringe with Berlin blue and connect it by means of a rubber tube
to the canula. Then with the tracer perforate the skin covering the
pad in the middle of the hand or foot of a cat just killed (see §§ 189-
194), and insert the canula. Push it into the tissues slightly and
force the piston slowly down; at the same time compress the foot
and press upon the limb in such a way as to facilitate the flow of
the mass centrad. It is well to insert the canula into all the pads
on the ventral surface of the manus or pes. It requires some time
to fill the vessels well. In the cat the larger trunks follow the veins.
If the leg is pressed as directed and the injection long enough con-
tinued (15-30 minutes), the thoracic duct may be filled.

§ 992, A. Lymphatics of the Neck and Face.—To inject these employ a similar or
the same specimen, and insert the canula in the naked place at the end of the snout, as
directed for the pad of the foot. Press on the nose and face. In this way the lymphatic
vessels on the face and in the neck and the lymphatic glands in Fig. 87 (GJ. lym.) are very
easily injected.

§ 992, B. Injection of Lymphatic Glands.—The lymphatic glands upon an injected
vessel are injected, since the vessels enter them. One may, however, inject the glands
directly and so fill the efferent vessels. This is very easily done by inserting the canula at
the peripheral edge of the gland and injecting centrad. The gland will first become very
blue and then the mass will appear in the efferent vessels. Those at the side of the face
(Fig. 87) and the mesenteric glands (§ 731) are large and favorable for this operation.

If it is desired to make permanent preparations of the injected lymphatics, the blue
should be mixed with half its volume of the blue gelatin mass (§ 1450, Frey, A).

For the structure of the lymphatic vessels, see § 984.

Preparation—Fig. 103.—A cat was fed as described above
(§ 985). Then the arteries, but not the veins, were injected, and the
abdomen and thorax were opened as there described. The position
of the large lacteal trunk crossing the V. mesenterica superior was
then found as described, and a V-shaped incision made in it with

368 ANATOMICAL TECHNOLOGY.

scissors (Fig. 40) at the point where it crosses the vein. A canula
was inserted, but not tied. The injecting mass was thin and colored
with chrome yellow (§ 344, E). A very gentle pressure was exerted
in forcing down the piston of the syringe. The canula was lightly
compressed with the fingers where it was inserted in the vessel.
The receptaculum and duct were slightly compressed, the fingers
being moved at the same time cephalad, to facilitate the movement
of the injecting mass. When the duct seemed well filled, the can-
ula was removed. After the injection of the duct, the most caudal
part of the postcava was opened to allow the blood to escape, and
then loosely ligatured centrad of the incision. Finally, the veins
were injected with blue plaster (§ 342) from the axillary vein. After
an hour the vasa chylifera, receptaculum and duct were carefully
isolated as described above (§ 989). The specimen was preserved
as directed (§ 286).

Explanation of Fig. 103.—Adrn., Corpus adrenale—The adrenal or suprarenal
body. Aorta. A.rn., A. renalis—The renal artery. A. m.s., A. mesenterica supe-
rior—The superior mesenteric artery. The lacteal vessel which was injected extends nearly
parallel with this. A. c., A. celiaca—The ceeliac artery or axis. A. adreno-lumbalis—
The adreno-lumbar artery. AA. costales—The costal or intercostal arteries. A. brcph.,
A. brachio-cephalica—The brachio-cephalic or innominate artery. A. sbcl., sin., A.
subclavia sinistra—The left subclavian artery. A. sbclv. dext., A. subclavia dextra—
The right subclavian artery. A. vert., A. vertebralis—The vertebral artery. A. incstl.
sup., A. intercostalis superior—The superior intercostal artery. AA. sternales—The
sternal or internal mammary arteries. Cardia—The heart. C.1.az., Cavum lobi azygi
(§ 810, Fig. 89). Colon et cecum. Coste (14)—Ribs. In this cat there were fourteen
ribs. Crus dphrg. (diaphragmaticum)—One of the pillars of the diaphragm. Ductus
thoracicus sinistra—The left thoracic duct. Duod., Duodenum. Glind.lym., Glandula
lymphatica—One of the lymphatic glands. Several small branches connect it with the
injected lacteals. Humerus—See Fig. 46. Ileum—The part of the small intestine next
the cecum. Mesocolon—The duplicature of peritoneum belonging to the colon. M.
psoas. M. longus colli. M. serrat., M. serratus magnus (§ 664). M, teres (§ 680).
M. latissimus, M. latissimus dorsi (§ 635). N. splnch., N. splanchnicus—The two
splanchnic nerves are shown here (see Fig. 107). N.g.d., N. gastricus dorsalis—The
dorsal gastric nerve. N. g. v., N. gastricus ventralis—The ventral gastric nerve.
N. phrn., N. phrenicus—The left phrenic nerve. N. sympathicus—The left sym-
pathic or sympathetic nerve. Omentum majus—Epiploon (§ 727). Cés., Esophagus.
Postcv., Postcava.—The inferior or ascending vena cava. Pancreas. Recep. chyli,
Receptaculum chyli. V.m.s., V. mesenterica superior—The superior mesenteric vein.
V. sbelv. sin., V. subclavia sinistra—The left subclavian vein. V. jgl. ext., V. jugu-
laris externa—The external jugular vein.

Fig. 103, A—Termination of the left thoracic duct.

Vena subclavia sinistra—The left subclavian vein. V. brceph. sin., V. brachio-
cephalica sinistra. V. jgl. ext., V. jugularis externa—The external jugular vein.
Vas lymph. (lymphaticum)—One of the lymphatic trunks from the head.

CHAPTER IX.

NEUROLOGY—THE STUDY OF THE NERVOUS SYSTEM.

GENERAL CONSIDERATIONS—THE MYELON (SPINAL CORD) AND ITS NERVES—THE BRA-
CHIAL PLEXUS—THE VAGUS NERVE—THE SYMPATHIC SYSTEM—THE RELATIONS OF
THE SYMPATHIC AND MYELENCEPHALIC (CEREBRO-SPINAL) SYSTEMS—STRUCTURE
OF NERVOUS MATTER,

§ 998. General Considerations. — Verves. — Throughout the
body, distributed to all organs and membranes, there are white cords
which are neither hollow like the vessels nor inextensible like the
tendons, but composed of a greater or less number of fibers of a
peculiar structure (§ 1048). These cords are called nerves; the
_ larger ones are also distinguished as trunks, the smaller as branches,
the yet smaller as éwigs, and the final subdivisions as fibers or ter-
minal filaments.

§ 994. Ganglia.—The peripheral ends of the nerves are distributed to the various tis-
sues constituting the muscles, bones, viscera, membranes, etc. Their central ends, how-
ever, are sooner or later traceable to collections of ce//s (§ 1048, B), with which they are
more or less closely and directly connected. Such collections of cells, whether or not
intermingled with fibers, are called ganglia, or said to constitute ganglionic tissue.

§ 995. Alba and Cinerea.—In the ganglia the gray protoplasm of the nerve cells
imparts to the mass a more or less decided gray color. Hence the ganglionic tissue is
commonly spoken of as the gray matter, or more technically the (substantia) cinerea.

But although the central (ental) part of each nerve fiber is a band of gray protoplasm,
it is in most cases so completely covered by a white substance (myeline, medullary sheath
or white substance of Schwann), that the prevailing color of the fibrous nervous tissue is
white, and it is commonly known as the white substance, or more technically the (substan-
* tia) alba.

§ 996. Primary Divisions.—The nerves and ganglia may be
conveniently considered as forming two great divisions which are
tolerably distinct in location and functions, but are nevertheless
anatomically connected and physiologically associated: they are
the sympathic (sympathetic) and the myelencephalie (cerebro-spinal)
nervous systems.

24

370 ANATOMICAL TECHNOLOGY.

The latter is more directly connected with the skin and with the
skeletal muscles which are commonly voluntary.

The former is chiefly distributed to the viscera and to the vascu-
lar system, and is regarded by some as merely a dependency of
_the other.

§ 997. Central and Peripheral Portions.—Provisionally adopting the arrangement
above indicated as at least convenient, each of these two great divisions of the nervous
system consists of a central and a peripheral portion. The central portion of the sym-
pathic is a double chain of gangia placed along the ventral aspect of the columna ver-
tebralis, and thus within the ventral or visceral somatic cavity. Two pairs of these
ganglia are shown in Fig. 109, that of the left side displaced dorsad. The peripheral
part comprises the branches from these ganglia, with plexuses situated among or upon
the viscera and vessels, and numerous small ganglia in the walls of the intestine and else-
where. The details of the arrangement of this system will be given in connection with
Fig. 107 and 109, where also will be pointed out the existence of rami communicantes
between the sympathic and the cerebro-spinal systems.

The peripheral part of the cerebro-spinal system consists of nerves which occasionally
form pleauses (Fig. 104, 105), and present ganglia at points to be presently indicated.

The central part of the cerebro-spinal system is lodged within the canalis neuralis s.
cerebro-spinalis—the cavities of the cranium (§ 491) and vertebral column (§ 479). It isa
continuous mass of alba and cinerea. The cranial portion is the encephalon or brain,
and the spinal portion is the myelon or spinal cord. The dorsal aspect of the brain and
of part of the myelon is shown in Fig. 104.

§ 998. The Myelonal Alba and Cinerea—The cinerea of the myelon presents the form
of.a column deeply fluted on four sides, dorsa/, ventral and lateral. On a transection, the
appearance is approximately that of a letter H, the ends of the two uprights being curved
laterad. Hence these areas are commonly known as the cornua or horns, two dorsal and
two ventral.

The interspaces are occupied by the alba. Since, however, the myelon is nearly divided
into lateral halves by the fissures, dorsal and ventral, what would otherwise be single dor-
sal and ventral columns of alba are double; hence on each side there is a /ateral column
and a dorsal and ventral one. These features are indicated upon Fig. 109 and 112. The
general arrangement of alba and cinerea in the brain will be described in connection
with the structure of that organ in Chap. X.

§ 999. Motor and Sensory Nerves.—By means of experiments, it has been ascertained
that certain nerves mainly or exclusively transmit sensory impressions, made upon the
parts to which their peripheral ends are distributed, toward the myelencephaion, that is,
centrad or centripetally ; while others convey motor impulses to muscles in the opposite
direction, peripherad or centrifugally.

’ § 1000. Motor and Sensory Roots.—A nerve, especially a large trunk, usually contains
some of both sets of fibers; but near the junction of the trunks with the myelon, each
trunk divides into two roots, which are attached to the myelon upon its dorso-lateral and
ventro-lateral aspects respectively. Anatomically, these roots are dorsal and ventral (an-
terior and posterior), but physiologically, they differ as do certain of the cranial nerves:
the dorsal ones transmit impressions certrad, and the ventral ones transmit motor impulses
peripherad. Hence they are commonly designated as the motor and sensory roots of the
spinal nerves.

GENERAL CONSIDERATIONS. 371

§ 1001. The Cranial Nerves.—As will be shown in Chap. XI, there are reasons for

regarding some at least of the nerves which arise from the brain as representing the motor
and sensory roots of ordinary myelonal nerves.

$ 1002. Functions of the Alba.—So far as known, the nerves and other parts consisting
wholly of the white or fibrous nervous tissue are simply capable of transmitting impres-
sions which are made upon them ; their office is one of conduction only.

§ 1003. Funetions of the Cinerea.—Different portions of the gray or ganglionic nervous
tissue have been found to act in one or more of the following ways :---

(A) As Trophic Centers—The ganglia upon the dorsal roots of the myelonal nerve
trunks (Fig. 109) seem to preside in some way over the nutrition of those roots, and are
therefore said to have a trophic action. The same may be the case with the ganglia con-
stituting the central portion of the sympathic system.

(B) As Centers of Automatic Action.—The ganglia in the substance of the heart, and
perhaps in some other localities, appear to possess the power of bringing about the action
of the muscular fibers with which they are connected independently of other parts.

(C) As Centers of Inhibition —Certain portions of the cinerea seem to be able, either
automatically or otherwise, to interfere with, check or inhibit the activity of other parts
of the cinerea.

(D) As Agents of the Will.—Portions of the cortex cerebri appear to be immediately
under the influence of volition, which is unable to directly actuate other parts of the
brain or of the body.

(E) As a Medium of Conduction.—Acting as the agent of the Will, the cortical cinerea
must be capable of transmitting impressions and impulses to and from the rest of the body.
Moreover, there are reasons for believing that the myelonal cinerea does, or at least may,
take a share in the transmission of impressions and impulses between the brain and the
body.

(F) As a Center of Reflex Action.—Many actions, especially those of the viscera and
vessels, are brought about in an indirect way. An impression made at the peripheral
end of a sensory nerve is transmitted through the nerve and through the dorsal or sensory
root to the cinerea of the myelon. Here it is apparently transformed into a motor im-
pulse which leaves by one or more ventral roots and causes an action of the appropriate
muscles or vessels or viscera. This kind of action, which may be very complex, is called
reflex, and the cinerea is said to operate as a center for the reception and interpretation of
the message and the determination of the response to be made.

§ 1004. Analogies of the Nervous and Vascular Systems.—(A) Somewhat remotely ,
the twofold division of the former into the sympathic and the cerebro-spinal may be com-
pared with the division of the latter into the lymph and the blood vascular systems.

(B) Confining the comparison to the better known and more extensive divisions, each
presents a central and a peripheral portion. In each case the central organs are relatively
active and the peripheral passive. ,

(C) The vessels carry the blood, containing the elements of nourishment and the pro-
ducts of waste, together with heat. The nerves transmit impressions and impulses, by
means of which the different organs are connected and made capable of mutual and har-
monious action. Both vessels and nerves are thus channels of communication ; but they
differ as do rivers, canals, roads and railways from the telegraph and the telephone. The
relations established are of commerce on the one hand and intelligence on the other.

(D) Again, as the vessels are of two kinds, the arteries which carry blood from the
heart and the veins which return it thereto, so there are two sets of nerves, motor and sen-
sory, which transmit impulses in one direction and impressions in the other. The direc-

372 ANATOMICAL TECHNOLOGY.

tion in the arteries and the motor nerves is centrifuga’, while it is centripetal in the sensory
nerves and the veins. [For this reason, upon colored diagrams, it is at least convenient to
represent the motor nerves by red, the color of most arterial blood, and the sensory nerves
by blue, the color of the blood in most of the veins].

(E) Like the two kinds of vessels, the motor nerves divide and subdivide so as to form
smaller and smaller branches, while the sensory nerves unite and reunite to form larger
and larger trunks.

§ 1005. Differences between the Nervous and Vascular Systems.—Here, however, the .
strict analogy ceases. The connection of the two sets of nerves at the myelon is not well
understood, but it is certainly less simple than that of the great venous and arteria! trunks
at the heart, separated as they are only by the lungs.

Again, while the capillaries establish a complete continuity of the peripheral ends of
the arteries and veins, no such constant connection has been shown to exist between the
motor and sensory nerves, which commonly terminate independently either in muscle or
at sensitive surfaces ; but see Beale, A, 240.

The subdivision of the vessels is like that of a large stream into several smaller, all
being part of one. But as a rule the nerve fibers maintain their independence through-
out their course from the myelon to the termination, and the larger nerves are made up
by the association of many fibers, and not by their actual union into one large fiber.

Arteries and veins differ not only in that the former usually contain purer blood and the
latter that which is less pure (the pulmonary vessels forming exceptions to the rule); nor
even in that the current in the one is always toward the heart and in the other away
from it. The real distinction is in their structure, the arteries containing more elastic and
muscular tissue, by virtue of which they are more perfectly elastic and contractile ; their
walls also are relatively thicker, so that they remain open when empty instead of collaps-
ing like the veins. But no such distinctions have been ascertained between the motor and
sensory nerves, and the proof that a sensory nerve may transmit an impression in the
direction opposite to the usual one goes far to indicate that their properties as well as their
structure are identical, and that the difference in their functions depends upon the connec-
tions of their central end with the dorsal and ventral regions of the myelon and of their
peripheral ends with muscles or with sensitive parts.

THE’ MYELENCEPHALIC OR CEREBRO-SPINAL
NERVOUS SYSTEM.

§ 1006. The Myelon.—This, called also chorda spinalis or
spinal cord, is the longer and more slender portion of the myelen-
cephalon or central part of the cerebro-spinal axis, and is lodged
within the canalis neuralis of the columna vertebralis (§ 479).

References to the Myelow.—Quain, A, I, 568, and IT, 489 ; Gray, A. 602; Hyrtl, A, 468 ;
Gegenbaur (Lankester), A, 512; Chauveau, A, 709; Chauveau (Fleming), A, 666 and 747 ;
Gurlt, A, 715; Owen, A, III, 73; Milne-Edwards, A, XI, 257; Leyh, A, 504.

As briefly stated in $§ 997, 998, the myelon isa continuous mass of alba and cinerea,
and is functionally a gigantic motor. and sensory nerve, an elongated ganglion and a cen-
ter of reflex actions, It may be conveniently divided into regions corresponding with
those of the vertebral column, cervical, thoracic, lumbar, sacral and caudal; but the ana-
tomical distinctions between them consist chiefly in the increase or decrease of the cinerea

THE MYELONAL NERVES. 373

or of the alba. Corresponding with the origins of the large nerves forming the brachial
and sacral plexuses, and supplying respectively the arms and the legs, the myelon presents
enlargements which, from their location, are known as the cervical and lumbar enlarge-
ments. The cephalic end differs from the rest in several respects, which will be indicated in
Chap. X; it is commonly regarded as a division of the brain under the name of medulla
or metencephalon.

The dorsal aspect of the cervical and of part of the thoracic myelon is represented in
Fig. 104 ; transections of it are given in Fig. 99, 100, 109 and 112.

§ 1007. The Myelonal or Spinal Nerves.—These arise from the myelon or spinal cord
(Fig. 104) and, except in the lumbar region, pass almost directly laterad through the inter-
vertebral foramina, and are distributed to the tissues. If a section of the body be made at
the proper level, as in Fig. 109, it will be seen that the nerves are in pairs, and that each
nerve trunk arises by two roots—the dorsal (posterior) root arising from the dorso-lateral
aspect of the myelon, and the ventral (anterior) root from the ventro-lateral aspect. These
extend toward the intervertebral foramen, piercing the dura on theirway. In the foramen
they unite to form the nerve trunk, but just as they unite there appears on the dorsal (pos-
terior) root a swelling—the ganglion of the dorsal root (§ 999).

The nerve trunk soon divides into two primary divisions—the dorsal or posterior pri-
mary and the ventral or anterior primary division (Fig. 109), The dorsal primary division
supplies the parts dorsad of the spinal column, while the ventral supplies the parts ven-
trad of the spinal column, including the limbs. For the most part, the ventral are much
larger than the corresponding dorsal divisions; the swboccipital and the great occipital
nerves are, however, exceptions (see explanation of Fig. 104). The myelonal nerves are
sometimes designated by the names of the groups of vertebre through whose intervertebral
foramina they emerge—cervical, thoracic, lumbar, sacral and coccygeal or caudal (§ 463).

Preparation—Fig. 104.—The muscles covering the spinal column were first carefully
removed on the left to the level of the vertebral laminew. The neural arch was removed
with nippers, entirely on the left, partly on theright. This exposed the myelun, the nerves,
and—on the left—the vertebrarterial canal with its contained vertebral artery. The left
nerves were then isolated by commencing at their origin and tracing the ventral primary
division peripherad, removing the muscles and connective tissue with the tracer, forceps
and scissors. The MM. rhomboideus and serratus (magnus) were cut and the scapula
strongly lateriducted, to expose the brachial plexus. The parts of this plexus were then
carefully isolated ; (compare with the ventral view, Fig. 106). On the right, the dorsal
primary divisions of the nerve trunks were isolated as described for the left (see also
§ 1008). They are as a rule smaller than the ventral, and hence require more care for
their isolation. The myelonal dura was entirely removed from the left side with the fine
forceps and scissors, but only to the level of emergence of the nerves on the right.
Finally, the skull was nipped away from the dorsal and lateral aspects of the brain, com-
mencing at the foramen magnum (Fig. 55); see Chap. X.

In preserving this specimen, the rectum was cleared and the abdomen and thorax filled
with 95 per cent. alcohol (§ 282); then it was suspended in a jar of alcohol ($ 286) by a
cord tied to the tail and legs. Cotton was placed in the metaccelia or 4th ventricle, to
raise the cerebellum, and between the hemispheres, to divaricate them sufficiently to
show the callosum.

Explanation of Fig. 104.—Cerebellum, az.—Epencephalon ; Chapter X. Costz (7)
—The first seven ribs. Dura—Dura mater of the myelon. Fm. alt., Foramen atlantale
The atlantal foramen in the cephalo-dorsal margin of the atlas; through it pass the A.
vertebralis and the NV. suboccipitalis or 1st cervical nerve. Ganglion—Ganglion on the

374 ANATOMICAL TECHNOLOGY.

Fie. 104.—Dorsat ASPECT OF THE BRAIN AND OF PART OF THE MYELON WITH ITS
NERVES; x.75.

DISSECTION OF THE NERVOUS SYSTEM. 375

dorsal (posterior) root of the 6th left cervical nerve ; ganglia are present on all as shown in
this figure ; see also Fig. 109. Hemisphzre—Cerebral hemispheres, prosencephalon ;
see Chap. X. MM. (lv. scp.) levator anguli scapule et serratus (magnus) (§ 664). M.
sbscp., M. subscapularis—The light streak between this and the preceding muscle is
the glenoid border of the scapula (Fig. 44). M. supraspinatus—See § 673. MM. tra-
pezii—Trapezius muscles ; see Fig. 66. N.accessorius—The spinal accessory nerves (xi) ;
this nerve passes along the ental surface of the trapezius muscle ; see also Chap. X. N.
crem., N. circumflexus (§ 1024). N. ctn. int., N. cutaneus internus (§ 1021). N.
hpgls., N. hypoglossus—The 12th pair of cranial nerves ; Chap. X. N., latis., N. latis-
simus—Nerve of the ©. latissimus dorsi (§ 1023). N. medius s. medianus (§ 1025). N.
m. spiralis, N. musculo-spiralis (§ 1026). N.m. ctn., N. musculo-cutaneus (§ 1022).
NN. myen., dv. dsl., NN. myelencephalici, divisio dorsalis (15)—Dorsal (posterior)
primary division of the first 15 myelencephalic or cerebro-spinal nerves. NN. myen., dv.
vnt. (15), NN. myelencephalici, divisio ventralis—The ventral (anterior) primary divi-
sion of the first 15 myelencephalic or cerebro-spinal nerves. N. oc. (occipitalis) major—
This forms the dorsal part of the 2d cervical nerve ; it receives a large anastomotic branch
from the 3d cervical nerve ; this nerve is distributed to the dorsal and caudal regions of
the head; in the 1st and 2d cervical nerves the dorsal primary divisions are as large or
larger than the ventral (§ 1007). N.rhmb., N. m. rhomboidei—Nerves of the romboideus
muscle. N. sbscp., N. subscapularis (§§ 942 and 1023). N. spscp., N. suprascapu-
laris—A large nerve from the brachial plexus; it sends a branch to the clavicular end of
the clavo-trapezius, but is mainly distributed to the scapular muscles ; it is in company
with the suprascapular artery; see §$ 937, 1020, and Fig. 105. N. suboccipitalis—The
ist myelonal nerve ; its name is not written, but it traverses the Wm. atl. with the A. ver-
tebralis. N. thr. post.,N.thoracicus posterior—The eaternal respiratory of Bell (§ 1029);
see § 1019 for the internal respiratory or phrenicus. N. ulnaris (§ 1028).

§ 1008. General Directions for Dissecting the Nervous Sys-
tem.—The precautions mentioned in § 596 (10) should be carefully
observed, and especial care taken that the part under examination
should be in a good light. Employ a tripod magnifier (Fig. 36)
whenever necessary to determine the course or relations of small
branches. Change the position of the cat as often as is necessary
to get the given part in the best light or to make it more accessible.

“Whenever a part is dissected, it should be kept moist by recov-
ering it with skin or sheet rubber, or by placing upon it a tuft of
cotton wet with 15 per cent. glycerin (§ 170).

In fresh animals, nerves may be distinguished from connective
tissue or empty vessels by their glistening and wavy or crimped
appearance when looked at closely. An uninjected vessel may
always be distinguished by cutting a slit in it and demonstrating
its tubular character with the tracer.

§ 1009. Instruments and Material.—Fifteen per cent. glycerin; cotton; towels or
cloths; pins; tracer; fine, coarse and bone scissors ; nippers; scalpels; arthrotome ;
injecting apparatus and material (Chapter IV); skeleton, and a natural skeleton of the
arm (§ 252).

376 ANATOMICAL TECHNOLOGY.

Choice of Specimen.—A lean cat with milk teeth is preferable ; young, because the
bones are softer and more easily cut ; ean, because the tracing of nerves is difficult even
when unobscured by fat. The usual precautions for cleanliness should be observed (§ 199),
and if it be desired to demonstrate the vertebra! artery as in Fig. 104, the arteries should
be injected from the abdominal aorta or tlie femoral artery ($$ 345, 363). The cat should
be deprived of blood by opening the V. femoralis near Poupart’s ligament, centrad of the
last pair of valves (§ 362), or the postcava may be opened.

Posture.—Place the cat ventricumbent with a block between the
arms and under the neck, so that the structures on the dorsal part
of the body may be somewhat tense. The legs should be tied to
the tray, so that the subject will not move too much.

§ 1010. Haposure and Dissection.—Part the hair (§ 354) along
a line 1 cm. sinistrad of the dorsimeson, commencing at the basé of
the skull and ending opposite the gleno-vertebral angle of the scap-
ula. Cut the skin along this line and reflect it for 2-3 em. on the
left and just beyond the dorsimeson on the right. In reflecting the
skin on the right, it should be form from the body rather than cut,
so that the nerves passing into the skin may be more easily de-
tected. During the dissection the parts should be kept covered
with skin as much as possible and moistened occasionally with 15 per
cent. glycerin. In case it takes more than one day to complete the
study, the preparation should be moistened with 15 per cent. gly-
cerin, covered with skin and then with a damp towel, and kept in a
cool place. As the dissection of a given part is completed, there
should be laid upon it a tuft of cotton moistened with 15 per cent.
glycerin.

§ 1011. Demonstration of the Ventral Primary Division of
Nerves of the Left Side (Fig. 104).— After the skin is reflected on
the left side, commence in the 7th intervertebral space and cut the
muscles from the left half of the neural arch (§ 478), and with the
tracer carefully isolate the nerve as it emerges through the interver-
tebral foramen (§ 484). Then with the nippers remove the left half
of the neural arch, and the origin of the nerve from the myelon will
be seen. Continue to expose the nerves in this way until the 2d
cervical or great occipital nerve is reached. This does not emerge
through a special intervertebral foramen, but between the arches of
the atlas and axis; hence the ganglion is imbedded in the muscles.
It is most safely isolated by tracing it from the surface toward its
origin. This nerve is easily seen on the caudal part of the head and
through the clavo-trapezius muscle if the cat is lean. One might
also begin with the WV. auricularis magnus (Fig. 87) the ventral

_ DORSAL DIVISION OF SPINAL NERVES. 377

primary division of the 2d cervical. Use the scalpel and tracer to
remove the muscles. After the ganglion is exposed, the neural
arch may be removed as usual with nippers.

The removal of the 1st or suboccipital also requires care, as it
traverses the atlantal foramen. The muscles must be carefully
removed from the dorsal side of the atlas, commencing caudad.
The ganglion of this nerve is either in the muscles immediately cov-
ering the #’m. atlantale (§ 474) or just within the mouth of the fora-
men; hence the muscles must be very carefully removed until the
nerve is uncovered. It may then be traced peripherad as far as
desired, and the dorsal part of the atlas removed with nippers..

If it be desired to follow the brachial plexus as shown in Fig.
104, the rhomboideus and trapezius muscles must be removed (Fig.
66, 67), and also part of the serratus magnus (Fig. 73). Then the
scapula should be strongly lateriducted. This will expose the
brachial plexus and its anastomoses, and the final trunks may be
made out by carefully dissecting with the tracer, fine forceps and
tine scissors. The lst thoracic will be seen to pass entad of the Ist
rib on its way to join the brachial plexus.

The distribution of the N. accessorius (xi) may be easily found,
as it extends along the ental surface of the IZ. trapezius, reaching
this point soon after its emergence from the /m. jugulare in com-
pany with the V1. vagus et glossopharyngeus ; see § 562.

§ 1012. Demonstration of the Dorsal (Posterior) Primary Division of the Nerves on the
Right Side (Fig. 104).—In removing the skin from the right side, it should be torn rather
than cut: then the branches of the dorsal primary division going to the skin will be seen
as white cords which penetrate the muscles in the dorsal region and pass to the skin.
These branches should be followed through the muscles, using tracer, scissors, scalpel
and forceps as is necessary. Trace the dorsal division until it joins the ventral division
(Fig. 109). After the nerves are isolated, the right side of the neural arch should be
removed to the level of the intervertebral foramina, After the myelonal nerves are iso-
lated and the myelon uncovered, some cotton wet with 15 per cent. glycerin should be
placed upon the myelon and damp towels over the whole dorsal region, to protect the
parts from injury or drying.

§ 1013. Exposure of the Brain.—The 12th, 11th, 10th, 9th and
7th cranial nerves (PI. I, II), on the left side should be isolated. In
doing this, have at hand a skull and Fig. 56, 57, 59 and 107, also the
Table in § 562. If the structures are carefully removed opposite the
points of exit of the various nerves, they may be easily found and
traced as far peripherad as desired. After the nerves are isolated,
the roof of the skull should be removed with nippers. In doing

378 ANATOMICAL TECHNOLOGY.

ees hire
ss A

Fic. 105.—VENTRAL ASPECT OF THE RIGHT BRACHIAL PLEXUS AND ITS NERVES: x.9.

——

THE BRACHIAL PLEXUS. 379

this, ventriduct the head and insert one blade of the nippers into
the foramen magnum (Fig. 56, 57, 59), and remove the O. swpraoc-
cipitale piecemeal. Remove also the parietal and frontal bones in
the same way until the dorsal aspect of the brain is entirely uncov-
ered. The bony tentoriwm (Fig. 59, 88) will remain, but its dorsal
border will be free. ‘To remove it, separate slightly the hemispheres
and cerebellum, insert the nippers and break the tentorium on both
sides. It may then be removed with the coarse forceps.

§ 1014. Removal of the Dura.—After the hard parts are re-
moved from the central nervous system, the dura, a tough membra-
nous sac enclosing it, should be partly removed by grasping the
membrane at some point where it is relaxed and cutting away a
piece at a time. Grasp the cut edge of the dura with the forceps
and lift it away from the underlying nervous matter so that the
scissors may be inserted. Remove the dura, proceeding with ex-
treme caution, especially around the nerve roots. Sometimes it
will be necessary to employ fine scissors and fine forceps and the
tripod magnifier, especially in cutting the dura from the roots of
the cranial nerves. The fan-like appearance of some of the nerve
roots on their emergence may be well seen with the magnifier.

THE BRACHIAL PLEXUS AND THE PRINCIPAL NERVES OF THE RIGHT
ARM AND SCAPULAR REGION,

References.—Quain, A, I, 582; Gray, A, 671; Hyrtl, A, 543 ; Gegenbaur (Lankester),
A, 514; Chauveau, A, 800; Chauveau (Fleming), A, 754; Gurlt, A, 749; Owen, A, III,
170, 176 ; Milne-Edwards, A, XI, 239 ; Leyh, A, 537.

Instruments and material, see § 1009.

§ 1015. The Brachial Plexus is the network of nerves from which the scapular
region and the arm are supplied. It is formed by the intimate connection of the ventral
(anterior) primary divisions (§ 1007) of the 6th, 7th and 8th cervical and the 1st tho-
racic nerves.

Fig. 105 and the description are given to illustrate the relations and distribution of
spinal or myelonal nerves in a well defined region.

For the study of this subject, the student should have before him a natural skeleton of
the arm, including the scapula (§ 252).

§ 1016. Specimen, Posture and Preparation.—The same specimen may be employed
as for Fig. 104, but it is better to use a different one. It should, however, be of the same
character, viz., young and lean.

Preparation of Fig. 105.—The cat was injected from the abdominal aorta with thin
plaster ($$ 345, 363). Then the skin was removed from the axillary and pectoral regions,
and from the caudal aspect of the arm to the wrist. The pectoral, clavo-mastoid, clavo-
trapezius, epitrochlearis and pronator teres muscles ($§ 680, 681) were then cut and turned

880 ANATOMICAL TECHNOLOGY.

aside. The veins of the arm were wholly removed, the arteries and nerves carefully
traced with fine scissors, forceps and tracer. The animal was transected (§ 234) and the
cephalic half preserved in alcohol (3 286).

Explanation of Fig. 105.—A. carotidea—The right carotid artery ($927). A. spscp.,
A. suprascapularis—The suprascapular artery ; the main branch of this artery accompa-
nies the WV. suprascapularis, but in this figure only the smaller branch of the artery to the
trapezius muscle is shown ; see § 937. A. crem., A. circumflexa—The circumflex artery
($ 941). A. sbsc., A. subscapularis—The subscapular artery (§ 942). A. axl., A. axil-
laris—The axillary artery (§ 938). A. thor. (thoracica) longa—The long thoracic artery
(§ 940). A. thor. ant., A. thoracica anterior (§ 939). A. br., A. brachialis—The bra-
chial artery (§ 943). A. ulnaris—The ulnar artery (§ 945). <A. interosseus—The inter-
_ osseous artery (§ 944, D). A. radialis—The radial artery (§ 946). Eminentia hypothenaris
—The hypothenar eminence. Fm. eptrch., Foramen epitrochleare; see Fig. 46.
MM. pectorales—The cut end of the pectoral muscles (§ 640). M. cred, M. coracoideus
(§ 668). M. biceps (§ 691). M. entrc., dv. cd., M. entotriceps, divisio caudalis (§ 685).
M. medtrc., M. meditriceps (§ 683). M. eptrch., M. epitrochlearis (§ 681). M. serra-
tus (magnus), (§ 664). M.scalenus. M. rectus thor.(thoracicus). N. vagus et sym.
(sympathicus), (Fig. 107). N. crv. (4), N. cervicalis (4). N. crv. (5), N. cervicalis
(5). N. crv. (6), N. cervicalis (6). N. spscp., N. suprascapularis—The suprascapular
nerve (§ 1020). N. phrn., N. phrenicus—The phrenic, diaphragmatic or internal respira-
tory nerve (§ 1019); see § 1029 for the external respiratory. N. thr. ant. (ectal s. cph.),
N. thoracicus anterior (ectalis s. cephalicus)—The anterior (ectal or cephalic) division
of the thoracic nerve (§ 1018). N.m. ctn., N. musculo-cutaneus—The musculo-cutane-
ous or the external cutaneous nerve (§ 1022). N.sbscp., N. subscapularis—The sub-
scapular nerve ($ 1023). N. crem., N. circumflexus—The circumflex nerve (§ 1024). N.
m. spiralis, N. musculo-spiralis—The musculo-spiral nerve (§ 1026). N. medius s. me-
dianus—The median nerve (§ 1025). N. int. ctn., N. cutaneus internus—The internal
cutaneous nerve (§ 1021). N. latis., N. m. latissimi—Nerve of the latissimus or the
long subscapular nerve (§ 1023). N. thr. ant. (ental. s. cd.), N. thoracicus anterior (en-
talis s. caudalis).—The anterior (ental or caudal) thoracic nerve (§ 1018). N. thr. post.,
N. thoracicus posterior—The posterior thoracic or the external respiratory of Bell
($§ 1018, 1029). N. radialis—The radial nerve, a branch of the musculo-spiral (§ 1026).
N. interos. ant., N. interosseus anterior—The anterior interosseous nerve ; the pos-
terior interosseus is a branch of the musculo-spiral ($§ 1025, 1026). Pili tactiles—Tactile
hairs ; to these extend a branch of the N. ulnaris (§ 1028). Ramus dorsalis—The dorsal
branch of the ulnar nerve (§ 1029). Trachea—The windpipe (§ 799).

Preparation of Fig. 106.—This is the same as for Fig. 105, except that all of the soft
parts were removed so as to show the exit of the nerves from the intervertebral foramina.

Explanation of Fig. 106.—A. brachialis—The brachial artery. N.suprascapularis
—The suprascapular nerve. N. crv. (6), N. cervicalis—The 6th cervical nerve. N. sub-
scapularis—The subscapular nerve. N. crv. (7), N. cervicalis—The 7th cervical nerve.
N. musculo-cutaneus—The musculo cutaneous or external cutaneous nerve. N. crcm.,
N. circumflexus—The circumflex nerve. N. thr. ant. (ectal. s. cph.), N. thoracicus
anterior (ectalis s, cephalicus)—The anterior (ectal or cephalic) division of the thoracic
nerve. N. medius s. medianus—The median nerve. N. musculo-spiralis—The name
is not written, but it is the large blank one arising from the 8th cervical ; see Fig. 104 and
105, § 1026. N. crv. (8), N. cervicalis—The 8th cervical nerve. N. ulnaris—The ulnar
nerve. N. thr. (1), N. thoracicus s. dorsalis—The 1st thoracic or dorsal nerve. N.
cutaneus internus—The internal cutaneous nerve. N. latis., N. m. latissimi—The

THE BRACHIAL PLEXUS. 381

To m:m lente an ihe sg
and rhoml-éide

Merv (§)

M. the. (!)

Frcostanens inter nus

i =
ey, x SS
e Hee

Fie. 106 —DIAGRAM OF THE RIGHT BRACHIAL PLEXUS, VENTRAL VIEW; x about 2.

nerve of the WM. latissimus dorsi or the long subscapular nerve (§ 1023). N. thr. ant.
(ental. cd.), N. thoracicus anterior (entalis s. caudalis)—The anterior thoracic nerve,
ental or caudal division. N. thr. post., N. thoracicus posterior—The posterior thoracic
nerve or the external respiratory of Bell. To M. levator ang. scp. and rhomboideus—
The nerve to the levator anguli scapule and rhomboideus muscles. To M. clavo-deltoi-
deus—The nerve to the clavo-deltvideus muscle.

Dissection of the Brachial Plexus.—The cat should be dorsi-
cumbent and the arms secured laterad with cords as in Fig. 76.
A block should be placed flatwise under the shoulders, so that the
head may be slightly dorsiducted ; later in the dissection, the arm
may be supported by a block. The arteries should be injected
with thin plaster (§§ 345, 352, 363), from either the abdominal aorta
or the femoral artery. If the cat is to be used only for this prepa-
ration, it should be transected (§ 234).

§ 1017. Haposure.—Make a longitudinal incision through the
skin 2 em. dextrad of the ventrimeson, commencing at about the
middle of the neck and ending opposite the base of the xiphisternum.

3882 ANATOMICAL TECHNOLOGY.

Then make a transverse incision 2-3 cm. long, from the beginning
of the longitudinal incision, dextrad. Then, commencing at a point
opposite the Ist rib, cut through the skin along the caudal (wpper
in present posture) side of the arm to theelbow. After the nerves are
studied in the brachium, the longitudinal incision on the caudal
side of the arm will be continued to the pad in the palm of the hand.

Reflect the skin just across the ventrimeson by grasping the cut
edge and tearing it from the structures which it covers. Grasp the
corner of the cephalic flap and tear the skin from the arm and
shoulder, exposing as much as is shown in Fig. 105. Reflect the
skin from the dorsal side of the arm in the same way, because, if
done in this manner, any nerves entering it can be readily seen,
whereas if the scalpel is used freely, they will be cut with the con-
nective tissue.

After the skin is reflected, make an incision through the muscles
2 cm. from the ventrimeson, commencing and ending as for the skin.
It is necessary to proceed with extreme caution, to avoid cutting the
vessels and nerves entad of the muscles. In the neck the cut should
divide only the muscles covering the carotid artery, the vagus
and sympathic nerves (Fig. 101). It is best to uncover these struc-
tures at the beginning of the incision and keep them in view. In
cutting the pectoral muscles, one should proceed in the same man-
ner. When the muscles are divided, the mesal edge should be
grasped by the hand and turned mesad, taking care not to break
any of the nerves entering them. The lateral ends of the muscles
should likewise be turned laterad with the same caution. Finally,
separate carefully the ILM. epitrochlearis and biceps to the elbow,
cutting, however, just deep enough to expose the internal cutaneous
and median nerves (Fig. 105). The above incisions will expose the
brachial plexus and the principal branches arising therefrom.

Commencing as near the meson as possible, with tracer, fine for-
ceps and fine scissors, remove fat and connective tissue from the
vessels and nerves. Fat is moderately tender, and both it and con-
nective tissue are more easily torn than either blood vessels or
nerves ; the nerves too may be recognized as directed above (§ 1008) ;
the arteries, being filled, will serve as landmarks. The azillary
vein should be removed, great care being used so that no nerves
are cut in the operation.

§ 1018. N. thoracicus anterior (Fig. 105, 106; Quain, A, I, 584;
Gray, A, 672).—The anterior thoracic nerve passes ventrad from the

N. PHRENICUS. 383

brachial plexus to the pectoral region. It is divided into two parts,
or rather there are two nerves—an ectal or cephalic division, accom-
panying the anterior thoracic artery between the muscles (§ 939),
and an ental or caudal division, accompanying the long thoracic
artery (§ 940), and distributed to the pectoral and also somewhat
to the latissimus muscle. The two are connected near their origin
by an anastomosing branch, as shown in Fig. 105 and 106.

Dissection —If the section was properly made through the pec-
toral muscles, the ectal or cephalic division will be turned mesad and
the ental division laterad. Both are easily found, and their relations
and distribution can be determined by using the tracer and fine
forceps. |

§ 1019. N. phrenicus s. diaphragmaticus (Fig. 103, 105, 107;
Quain, A, I, 578; Gray, A, 669).—This nerve is formed by two
branches, one from the 5th and one from the 6th cervical nerve. It
also occasionally receives a branch from the 4th cervical, as in man.
The latter condition is shown in Fig. 105, while the more frequent one
is shown in Fig. 107. These dranches unite near the 1st rib, and the
phrenic then passes into the thorax on the mesal side of the A. ster-
nalis (Fig. 107,109). The right nerve rests on the lateral aspect of
the pree- and postcavee on its way to the diaphragm, to which it is
distributed. The course of the left is well shown i in Fig. 103 and
107, WV. phrn.

Dissection —The branches forming the phrenic nerve are quite
small, hence it is best to trace the nerve centrad from the point
where it enters the thorax ; the branches may then be isolated one
by one. When this is done, the costicartilages and the thoracic
walls may be cut and the two edges divaricated. The nerve will
appear very clearly as a white cord passing along the lateral aspect
of the pree- and postcavee to the diaphragm.

§ 1020. IN. suprascapularis (Fig. 104, 105, 106; Quain, A, I, 583 ;
Gray, A, 672).—The suprascapular nerve arises from the 6th cervi-
cal. It passes directly laterad for a short distance and then divides
into two branches, one going to the ental surface of the IZ clavo-
deltoideus, the other to the ectal surface of the scapula. These two
branches accompany the branches of the swprascapular artery
(§ 937).

Dissection.—This nerve is easily traced. It follows closely the
corresponding branches of the suprascapular artery, and may be
traced as directed for that vessel (§ 937).

384 ANATOMICAL TECHNOLOGY.

§ 1021. N. cutaneus internus (Fig. 104, 105, 106; Quain, A, I,
585; Gray, A, 675).—The internal cutaneous nerve arises wholly
from the 1st thoracic. It becomes subcutaneous at about the distal
third of the brachium, emerging from between the epitrochlearis
and biceps muscles about opposite the point where the WV. radialis
emerges from between the biceps, clavo-deltoideus and ectotriceps
(Fig. 74) ; hence it is liable to be destroyed in removing the skin or
in the exposure (§ 1017) unless care is taken. It gradually curves
from the dorso-caudal to the ventral aspect of the arm, and is dis-
tributed mostly to the skin of the brachium and antebrachium on
the caudal and ventral aspects.

Dissection.—It is best to isolate the 1st thoracic near its origin
to find the origin of the internal cutaneous nerve; it may then be
traced peripherad, or it may be found on the ventral side of the
arm, where it becomes subcutaneous, and traced in both directions.
The presence of the nerve of Wrisberg has not been satisfactorily
determined in the cat.

§ 1022. NN. musculo-cutaneus s. cutaneus externus (Fig. 104,
105, 106 ; Quain, A, I, 587; Gray, A, 674)—The musculo-cutaneous
nerve arises from the ventral surface of the 6th and 7th cervical
nerves. It is also closely connected with the WV. medius (Fig. 106).
It passes almost directly toward the shoulder joint, and when near
the trochin gives several filaments to the coracoideus and biceps
muscles. It passes entad of the long head of the IZ. coracoideus,
and continues distad along the brachium, resting on the caudal
aspect of the biceps. Opposite the #'m. epitrochleare, a small
branch is given off which anastomoses with the WV. medius through
the foramen. In the concavity of the elbow it passes entad of the
MM. biceps to its cephalic aspect. -On the antebrachium it is subcu-
taneous and extends along the cephalic border of the arm parallel
with the WV. radialis (Fig. 105). It is distributed to both skin and
muscles, as the name indicates.

Dissection.—Commence near the shoulder joint and trace it first
centrad to determine its origin and communications, then peripherad
along its whole course. It will be necessary to employ a tripod or
other magnifier in tracing the anastomosis with the median at the
elbow. On the antebrachium the nerve is very near the surface,
hence the skin and fascia should be removed only by degrees and
while keeping the nerve in sight.

§ 1023. INN. subscapulares (Fig. 104, 105, 106; Quain, A, I,

N. CIRCUMFLEXUS. 585

584 ; Gray, A, 673).—There are two of these nerves, or, if the nerve
of the Zatissimus be counted, three (Fig. 105, 106). They all arise
from'the dorsal side of the brachial plexus, as shown in Fig. 104 and
106. The most cephalic one goes to the MZ. subscapularis, and the
intermediate one mostly to the feres. The long subscapular or
nerve of the Zatissimus passes caudo-laterad to the MZ. latissimus
in connection with a branch of the subscapular artery (§ 942).

Dissection.—The position of the nerves is indicated on the fig-
ures referred to. They may be isolated with the tracer; this should
be done very carefully on account of their position with reference
to the other nerves.

§ 1024. N. circumflexus (Fig. 104, 105, 106; Quain, A, I, 584;
Gray, A, 673).—The circumflex nerve arises from a sort of interme-
diate branch joining the 6th, 7th and. 8th cervical nerves. Fora
short distance it is in the closest relation with the cephalic of the
subscapular nerves. It passes nearly laterad and follows the cir-
cumflex artery as it winds around the dorsal side of the proximal
end of the humerus to terminate finally in the JZ clavo-deltoideus ;
see § 941.

Dissection.—Commence at the point where the nerve is crossed
by the musculo-cutaneous, and trace it first to its origin, and then
to the point where it disappears in company with the circumflex
artery. ‘The termination may then be seen by lifting the cephalic
edge of the clavo-deltoideus just distad of the ¢rochiter. Its entire
course may be traced from the periphery by cutting away the
muscles.

§ 1025. N. medius s. medianus (Fig. 104, 105, 106; Quain, A, I,
590; Gray, A, 675).—The median nerve in the cat is formed by three
branches, shown in Fig. 106, the brachial artery passing between
the cephalic and intermediate. It follows the direction of the artery,
lying ectad of it in most of its course and traversing with it the Fm.
epitrochleare, where it receives an anastomosing branch from the JV.
musculo-cutaneus (§ 1022). In the concavity of the elbow the nerve
passes entad of the JZ. pronator teres and follows the general course
of the bones of the antebrachium to the wrist. It furnishes branches
to the muscles on the ventral aspect of the antebrachium, and espe-
cially the JV. interosseus anterior, which accompanies the artery of
the same name (§ 944, D). Finally, it is distributed to the struc-
tures on the palmar aspect of the manus.

Dissection.—Commence at about the middle of the brachium

25°

386 ANATOMICAL TECHNOLOGY.

and trace the nerve to its origin, as shown in Fig. 105 and 106.
Then it may be followed peripherad, but great care should be
taken not to injure the WV. cutaneus internus or break the anas-
tomosing filament from the WV. mwsculo-cutaneus (§ 1022). In the
concavity of the elbow the 1. pronator teres should be divided and
the nerve followed in the antebrachium as described for the radial
artery (§ 944).

§ 1026. N. musculo-spiralis (Fig. 104, 105, 106; Quain, A, I,
592; Gray, A, 679).—The musculo-spiral nerve is formed largely
from the 8th cervical nerve, although it receives branches from the
1st cervical and the Ist thoracic ; it is the largest offset from the
brachial plexus. It winds obliquely around the humerus, com-
mencing at about its middle, being accompanied by the saperior
profunda artery (§ 945, B). After reaching the cephalic side of
the brachium, the nerve divides into two parts, which are known as
the radial and the posterior interosseus nerves.

NV. radialis,—This is the smaller of the two branches into which
the musculo-spiralis divides. It becomes subcutaneous as it emerges
from between the UW. ectotriceps, brachialis and clavo-deltoideus
(Fig. 74), near the distal end of the brachium. It then follows the
course of the vadius, remaining subcutaneous through the whole
length of the antebrachium. This nerve is closely associated with
the musculo-cutaneous. The single large superficial vein of the
arm also follows its course. It is partly cutaneous in its distri-
bution.

§ 1027. N. interosseus posterior.—This is the larger of the two
branches into which the musculo-spiralis divides. It passes along
the dorsal side of the antebrachium to the wrist. This nerve is
almost wholly muscular in its distribution.

Dissection.—The skin should be torn from the dorsal and ce-
phalic sides of the brachium, then the muscles carefully cut along
the course of the nerve. The JV. radialis will have been exposed
in the study of the musculo-cutaneus. The JV. interosseus may be
followed by cutting and tearing the muscles very cautiously with
a tracer.

§ 1028. N. ulnaris (Fig. 104, 105, 106; Quain, A, I, 588; Gray,
A, 677).—The ulnar nerve arises from the 8th cervical and the Ist
thoracic. It passes along the brachium parallel with the brachial
artery as far as the elbow, and then turns to the dorsal side of the
elbow. It passes along the dorso-caudal border of the antebra-

THE VAGUS NERVE. 387

chium to a point somewhat distad of its middle. Here it divides
into two divisions—a dorsal, which winds around to the dorsal side
of the manus, a ventral, which extends along the ventral surface to
the palm. Near the distal third of the antebrachium the ventral
division sends a considerable branch to the group of tactile hairs
near the hypothenar eminence (Fig. 105). If the skin is torn from
the antebrachium at this point, the roots of the hairs will be seen
to be similar to those of the vibrissze (Fig. 87, 88). In distribution
the ulnar is partly cutaneous, but chiefly muscular.

Dissection.—The dissection of the ulnar nerve is very simple,
and needs no special directions.

§ 1029. N. thoracicus posterior—The external respiratory nerve
of Bell (Fig. 104, 105, 106 ; Quain, A, I, 576; Gray, A, 671)—The
long thoracic or external respiratory nerve (so called because the
phrenic was called infernal respiratory) arises wholly from the 7th
cervical near its roots. It passes nearly caudad to be distributed
to the serratus magnus muscle. It may be seen readily as shown
in Fig. 105.

Dissection.—The rhomboideus and trapezius muscles should be
divided and the vertebral border of the scapula turned laterad.
The nerve may then be easily traced from its distribution to. its
origin.

NERVUS VAGUS, s. PAR VAGUM, s. N. PNEUMOGASTRICUS, 10TH PAIR.
(Fig. 101, 105, 107; Pl. Il, Fig. 3, WV. o. [x]).

References.—Quain, A, I, 557; Gray, A, 660 ; Hyrtl, A, 521; Gegenbaur (Lankester),
A, 518; Chauveau, A, 772; Chauveau (Fleming), A, 728; Gurlt, A, 737; Owen, A, III,
159 ; Milne-Edwards, A, II, 340; Leyh, A, 526; Dalton, A, Fig. 482; Stowell, 7.

§ 1030. The vagus or pneumogastric nerve (x) arises apparently from the side of the
medulla, passes laterad and traverses the #'m. jugulare in connection with the glossopha-
ryngeus and accessorius. Just as it emerges from the skull or just within the foramen,
it has a ganglion, the ganglion of the root, and about 1-2 cm. farther peripherad it pre-
sents a second ganglion, the ganglion of the trunk. The nerve passes along the neck in
company with the carotid artery, and from the ganglion of the trunk to a point near the
1st rib is so closely connected with the sympathie nerve that the two appear like one (Fig.
107). The vagus enters the thorax mesad of the A. sternalis, extends caudad along the
ventral aspect of the A. subclavia sinistra (§ 930), crosses the arcus aorticus, and while
crossing it gives off a long branch, the WV. /aryngeus recurrens, which winds around the
arch and extends cephalad along the trachea to the Jaryna (Fig. 107). The vagus then
passes caudad along the dorsal side of the root of the lung. » Slightly caudad of the root
of the lung it divides into two parts ; one, extending along the ventral side of the cesopha-
gus, soon unites with a branch from the right vagus (Stowell, Z), and the combined trunk,
the ventral gastric nerve, then passes along the esophagus, penetrates the diaphragm and

388 ANATOMICAL TECHNOLOGY.

is distributed to the ventral aspect of the stomach ; the other branch of the vagus winds
to the dorsal side of the esophagus, where it is joined by a small branch from the right
vagus. The union of the two forms the dorsal gastric nerve, which penetrates the dia-
phragm on the dorsal side of the cesophagus, and is distributed to the dorsal aspect of the
stomach and especially to its greater curvature (Fig. 79).

The vagus supplies branches to the laryna, trachea, heart, lungs, esophagus and stom-
ach, Throughout its entire extent it is closely related to certain spinal nerves and to the
sympathicus.

The origin, course and distribution of the right vagus is nearly the same as that of the
left, except that the recurrent laryngeal is given off opposite the A. subclavia deztra (Fig.
108), and winds around to its dorsal side to reach the trachea.

The account of the vagus is introduced partly in order to illustrate the origin, course,
distribution and relations of a peculiar cranial nerve, but especially on account of its
importance from an experimental standpoint.

DISSECTION OF THE VAGUS NERVE.

§ 1031. Specimen and Preparation.—The specimen should be young and lean (§ 1008).
The vascular system should be filled from either the femoral or abdominal vessels (§§ 352,
363). The same specimen is to be used for the sympathic (§ 1042).

§ 1032. Haposure and Dissection.—A block should be placed
under the cat’s neck so that the head may be slightly dorsiducted.
After parting the hair (§ 354), make an incision from the left exter-
nal auditory meatus to a point opposite the tip of the xiphisternum,
going about 2 cm. to the left of the ventrimeson. The skin should
be reflected on both sides of the incision for 2-3 cm. and held aside
with pins. Find the position of the larynx and trachea (Fig. 88) by
pressing on the ventrimeson.

Make a longitudinal incision through the sterno-mastoid mus-
cles just laterad of the trachea, commencing near the Ist rib and
cutting cephalad to the bulla (Fig. 57). It is necessary to proceed
with caution, however, in order not to injure the vessels and nerves
on the ental side of the muscle. Turn the cut edges of the muscle
aside and fasten them with pins. This will expose three structures
lying parallel to the trachea :—the carotid artery, which, being
injected, will be very apparent; at the same level as the carotid,
but laterad of it, the combined vagus and sympathic nerves ; and
finally between the two, but somewhat ventrad, the internal jugu-
lar vein (Fig. 101).

Commence near the middle of the neck and follow the nerve
cephalad, using the tracer, fine forceps and scissors. Near the
bulla (Fig. 57 and 107, B), the submazillary and lymphatic glands
(Fig. 87) and the thyroid body (Fig. 101) must be removed. At the
ganglion of the root the vagus may be easily separated from the

THE VAGUS NERVE. 389

sympathic (Fig. 107). From the ganglion of the root the I. laryn-

geus superior (Fig. 107, JV. 1. sup.) may be traced entad of the
carotid to the larynx.

§ 1033. N. hypoglossus (Fig. 107, JV. hpgls.).—A little cepha-
lad of the superior laryngeal nerve this will be seen crossing the
ectal surface of the carotid and extending to the tongue.

§ 1034. N.glossopharyngeus (Fig. 107, WV. gph., Plate II, Fig. 3,
NV. gph. {ix]).—Divide the I. digastricus (Fig. 101) near its middle
and reflect the two ends. This will expose the dwlla, and passing
along its caudo-mesal aspect will be seen the small glossopharyn-
geal nerve. From its exit at the #m. jugulare (Fig. 57, § 562), it
passes entad of the carotid on its way to the tongue.

§ 1035. N. accessorius.—The spinal accessory may also be seen
piercing the sterno-mastoid muscle and passing latero-caudad from
the Fm. jugulare to be distributed to the ental surface of the clavo-
trapezius muscle (Fig. 104, 107, 1V. ac.).

§ 1036. The path of the vagus through the foramen jugulare and
its relations with other nerves, also the ganglion of the root (Stow-
ell, 1), may be made out by nipping away the skull upon the
dorso-lateral side of the foramen.

After the parts just described have been determined, the nerve
should be followed caudad. Near the Ist rib the sympathic inclines
laterad (Fig. 107). The vagus passes into the thorax entad of the
V. brachio-cephalica (Fig. 101, 109).

§ 1037. Exposure of the Left Vagus in the Thorax.—Divide
the pectoral and other muscles, and costicartilages, about 1 cm.
from the meson, and turn the sternum dextrad, securing it with
chain hooks (§ 140) or strings. Then cut the left ribs with the nip-
pers about 2 cm. from their heads, and either remove this part of
the thoracic wall entirely or pin it down so that the thoracic cavity
shall be readily accessible.

Cut the left brachio-cephalic vein and turn it mesad as shown in
Fig. 107. The sternal artery (§ 935) may be cut near the sternum
and pinned laterad. Then the vagus may be followed with the
tracer, fine forceps and fine scissors. Note the phrenic nerve
(§ 1019), which crosses the vagus just cephalad of the sternal artery.
The phrenic may be easily traced along the thorax ventrad of the
root of the lung to the diaphragm, by pulling upon it near where it
crosses the vagus, and turning the lungs to the left.

390 ANATOMICAL TECHNOLOGY.

In tracing the vagus, be very careful to preserve all the branches
either given off or received by it. The main nerve is so large that
there is little danger of injuring it, but its branches are often very
small. It is a great help to pull the nerve in various directions with
the fingers or forceps; then the presence of branches or anasto-
moses may be detected by the tense lines extending from the main
nerve. There are several of these branches which leaye or join the
nerve on its way from the Ist rib to the aorta. One or two of these
come from the thyroid ganglion, two or three from the vertebral
ganglion. When near the arch of the aorta, the ventral side of the
vagus is crossed by the lesser cardiac nerve on its way to the car-
diac plexus from the vertebral ganglion (Fig. 107, JV. erd.).

§ 1038. N. laryngeus recurrens s. inferior (Fig. 107, 108).—
Just before crossing the ventral side of the aorta, the left vagus gives
off a large branch, which winds around to the dorsal side of the aorta
and follows the trachea cephalad to the larynx. Its origin may be
readily determined ; but to trace it on the trachea, the vessels should
be carefully removed in order to expose the trachea. This should
be deferred, however, until the vagus is traced to the stomach, or
it should be traced upon another specimen.

§ 1039. The vagus gives many branches to the heart and lungs
near the point where the nerve crosses the arch of the aorta. Their
branches are usually rather small, but their course may be made
out by pulling on the main nerve.

In tracing the vagus caudad of the arch of the aorta, the lung
should be turned mesad, so that the nerve may be seen as it passes
along the dorsal side of its root (Fig. 107). In following the nerve
in the remainder of its course, it is especially desirable to draw it
tense, for in this way is most surely and easily determined the pres-
ence of branches. Just caudad of the root of the lung, the nerve
will be found to divide, one part passing along the dorsal aspect of
the cesophagus, and the other remaining on its ventral surface.

§ 1040. Follow the ventral branch (N. gastricus ventralis, Fig.
103, 107). About half way between the root of the lung and the
diaphragm, there will be seen a branch joining it from the right.
This can be seen easily by pulling the nerve cephalad and to the
left. This branch is the ventral division of the vight vagus. The
combined trunks now pass along the diaphragm and penetrate it
with the esophagus. The diaphragm may be cut away, and then

THE VAGUS NERVE, 391

if the nerve trunk be pulled, the fan-like expansion of the nerve on
the ventral side of the stomach may be seen.

§ 1041. N. gastricus dorsalis (Fig. 103, 107).—Now follow the
dorsal division of the vagus. It winds around to the dorsal side of
the esophagus, and when within about 2 cm. of the diaphragm, a
large branch may be seen to join it. ‘This is the dorsal division of
the right vagus. Follow the combined trunk to the diaphragm,
then cut the diaphragm so as to expose the wsophagus; do this
carefully, so as not to injure the nerve. Now pull upon the dorsal
gastric nerve, and its fan-like expansion on the great curvature of
the stomach will be seen, and also a tense line passing dorso-caudad
to the semilunar ganglion of the solar plexus (Fig. 107, Ramus
cm., Gng. smin.). The left semilunar ganglion is at the left of the
A. mesenterica superior. It is a pinkish white body not difficult
to distinguish.

Preparation of Fig. 107.—The arteries and veins were injected from the abdominal
aorta and postcava ($$ 363, 365); the skin was then removed as shown in the figure, and
the ribs cut within 2-3 cm. of their heads ; the costicartilages were cut at about the same
distance from the sternum, and then the thoracic and abdominal walls were removed.
The arm was amputated near the middle of the brachium ; the sterno- and clavo-mastoid
muscles were also removed. The sternum and heart were turned to the right, together with
the brachio-cephalic vein. The left lung was cut off at its root and removed. The vessels
and nerves were then isolated as directed above (§ 1008).

Explanation of Fig. 107.—In the description of this figure, under the general heads,
which are arranged alphabetically, the special parts are named commencing at the caudal
extremity.

A. c., A. celiaca (§ 966). A. m.s., A. mesenterica superior (§ 967). A. cs., A.
cesophagea—One of the cesophageal arteries. Aorta (§ 965). A.V. cost., A. V. cos-
tales—The intercostal arteries and veins (Fig. 103). A. breph., A. brachio-cephalica
(Fig. 101, 102, 103), A. s., A. subclavia (§ 933). A. axillaris (Fig. 105,§ 9388). A.
sternalis (§ 935). A. carotidea—The left carotid artery; the name is written on the
trachea just mesad of the artery (Fig. 101, § 927). A. thyr., Axis thyroideus (§ 937).
A. 1, A. lingualis—The: lingual artery, a branch of the carotid. A. fac., A. facialis—
The facial artery, a branch of the carotid (Fig. 87). Adrn., Corpus adrenale—The adre-
nal or suprarenal body (§ 760). Cardia—Heart (§ 822). Costz(13)—Ribs. Costz ster-
nales (9). Dphrg., Diaphragma, (Fig. 90, § 815). D. Stenon., Ductus Stenonia-
nus—Duct of the parotid gland (Fig. 87, § 780). Gng. smnl., Ganglion semilunare—
The semilunar ganglion, the largest ganglion of the solar plexus (§ 1044). Gng. vert.,
Ganglion vertebrale—The caudal cervical ganglion of the sympathic ($ 1042). Gng.
thyr., Ganglion thyroideum— The thyroid or middle cervical sympathic ganglion
(§ 1043). Gng. crv. sym., Ganglion cervicale superius sympathici—The superior
cervical ganglion of the sympathic (§ 1043). Gng. inf. (vagus), Ganglion inferius vagi
—The inferior ganglion of the vagus, called also the ganglion of the trunk. Gl. (Glan-
dula) parotis—The parotid gland (Fig. 87, $$ 778, 779). Humerus (Fig. 46, § 407). M.
serratus mg. (magnus), (Fig. 73, § 664). M. teres (Fig, 75, § 680). M. latis., M. latis-

ANATOMICAL TECHN OLOGY.

392

Fie. 107.—THE Vasus anD SymMpaTHic NERVES; x.5. A. DIAGRAM OF THE SACRAL

PART OF THE SYMPATHIC NERVE; x about 3.

THE VAGUS AND SYMPATHIC NERVES. 393

simus (Fig. 67, § 635). M. msstr., M. massetericus. N. splnch. minor, N. splanch-
nicus minor (Fig. 103, § 1044). N. splnch. major, N. splanchnicus major, (Fig. 103,
§ 1044)—Both splanchnic nerves are seen to join the semilunar ganglion (gng. smin.).
N. gstr. vnt., N. gastricus ventralis—The ventral gastric nerve ; it is formed partly by
the right and partly by the left vagus, as is also the following (see Fig. 103, § 1040).
N. gstr. dor., N. gastricus dorsalis—The dorsal gastric nerve (§ 1041); a large branch
(ramus em.) is seen to unite this with the semilunar ganglion (gg. smiu.). WN. phrn., N.
phrenicus (Fig. 105, V. phrn.). N. sym., N. sympathicus—The sympathic nerve in.
the thorax (§ 1048). N.1.r., N. laryngeus recurrens—The recurrent laryngeal of the
left side winding around the aorta (see Fig. 108 and § 1038). N. crd., N. cardiacus—The
lesser cardiac nerve from the sympathic (Fig. 109). NN. thr. (2 and 4), NN. thoracici
(5 et 6)—The 5th and 6th thoracic nerves ; each receives a branch from the sympathic
(Fig. 109, § 1042). N. crv. (6th), N. cervicalis (6th). N. crv. (5th), N. cervicalis (5th)
—The phrenic nerve is seen to arise from this and the preceding (see also Fig, 105, § 1019).
N. vagus (x), (Fig. 103, $$ 562, 1080)—The vagus and sympathic appear as a single trunk
in the neck, but are easily separated, especially at their ganglia by the bulla (B.) and near
the Ist rib. N.sym., N. sympathicus s. N. sympatheticus—The great sympathic or
sympathetic nerve with its ganglia on the left side (Fig. 103, § 1042). N. 1. sup., N.
laryngeus superior (§ 1038). N. hpgls., N. hypoglossus (Fig. 104, $$ 562, 1038, Plate
II, Chapter X). N. ac., N. accessorius (spinalis xi), (Fig. 104, Plate II, Chapter X,
§§ 562, 1035). N. gph., N. glossopharyngeus, ix (Plate II, $$ 562, 1034, Chapter X). N.
aur. mg., N. auricularis magnus (Fig. 87). Cé&s., Gésophagus (Fig. 109,§ 801). Pcv.,
Postcava (Fig. 101, § 955). Ramus cm., N. ramus communicans—The nerve putting
into communication the gastric branch of the vagus and the semilunar ganglion. Rx.
plm., Radix pulmonalis—The root of the left lung. Stomachus (Fig. 79,§ 735). Trch.,
Trachea (Fig. 88, § 799). V.rn., V. renalis (Fig. 101, § 959). V.m.s., V. mesenterica
superior (§ 949}—The branch entering the V. m. 8. as it crosses the A. m. 8. is the V. mesen-
terica inferior (§ 950). V. cdrn.-lumb., V. adreno-lumbalis (Fig. 103, § 958). V. az.,
V. azygos (Fig. 91, 107, § 920). V. plm., V. pulmonalis—One of the pulmonary veins
just before entering the left auricle (Fig. 91). V. breph. sin., V. brachio-cephalica sin-
istra (§ 922).

Fig. 107, A.—The sympathic of the two sides in the sacral and part of the coccygeal
regions, showing the fusion or close connection of the ganglia and their connection with
the myelencephalic nerves ; x about 3.

Preparation of Fig. 107, A—The ventral half of the pelvic girdle (§ 455) was cut
away with nippers, and then all the pelvic viscera were removed. The sympathic nerves
were found resting on the lumbar vertebre by divaricating the psoas muscles, The nerves
were carefully traced to the sacral and coccygeal region, and their anastomoses with the
spinal nerves and the fusion of the ganglia were exposed by removing muscle, connective
tissue and the middle sacral artery with fine forceps, scissors and tracer, using also the
tripod magnifier whenever the branches became so smal] as to be in danger of injury from
not being distinctly seen.

Explanation of Fig. 107, A—Anst.—Anastomosis of the two ganglia. Gng. (gan-
glion) impar—A single ganglion formed by the fusion of those of the two sides; in the
one just cephalad the ganglia are not completely fused, but connected by anastomosing
fibers. Gng. (ganglion) impar (1st)—The 1st fused ganglion of the sympathic; it is
opposite the 2d sacral vertebra (§ 458). N. myen., N. myelencephalicus—Four myelen-
cephalic or cerebro-spinal nerves with their anastomosing branches from the sympathic.
N. sym., N. sympathicus—The nerves of the two sides approaching each other on the
sacrum. ;

394 ANATOMICAL TECHNOLOGY.

Preparation of Fig. 108.—The vagus and sympathic, together with the arteries, were
isolated as directed above ($ 1008). The left cardiac nerves from the thyroid and vertebral
ganglia frequently pass ventrad of the vagus, as shown in Fig. 107, and those of the right
side often pass to the heart along the ventral side of the blood vessels instead of as here
shown; see Quain, A, I, 632. ;

The figure is meant to illustrate the origin and course of the recurrent laryngeal nerve
on the two sides—(A) representing the right side, with the recurrent winding around the
A, subclavia dextra, and (B) the left side, with the recurrent nerve winding around the
arch of the aorta.

’ Fie. 108.—THE RECURRENT LARYNGEAL NERVES, VENTRAL VIEW, (Stowell, 2);
x about 1,

Explanation of Fig. 108.—The abbreviations are the same in the two figures.

Aorta, az. (§ 926). A. breph., A.*brachio-cephalica, az. (§ 943). A. subcl., A. sub-
clavia (§ 933). A. carotid., A. carotidea. A. stern., A. sternalis s. mammaria
interna. G. vert., Ganglion vertebrale (§ 1043). G. thyr., Ganglion thyroideum
($ 1048) N. vagus (§ 1030). N.1.r, N. laryngeus recurrens (§ 1038).

NERVUS SYMPATHICUS s. SYMPATHETICUS. (Fig. 90, 101,
103, 105, 107, 108, 109).

References.—Quain, A, I, 626; Gray, A, 696; Hyrtl, A, 572; Gegenbaur, A, 522;
Chauveau, A, 328; Chauveau (Fleming), A, 781; Gurlt, A, 767, 774; Owen, A, III, 181;
Milne-Edwards, A, II, 331; Leyh, A, 550.

§ 1042. The sympathic nervous system as a whole comprises a central system con-
sisting of a double chain of ganglia extending along the ventral side of the spinal column.
The two chains also extend into the head and into the tail. The ganglia are connected by

NN. SPLANCHNICI. 395

intervening nerves and give rise to nervous branches which are distributed to the viscera
and blood vessels. Besides the chain of ganglia, the sympathic nerves may have ganglia
developed upon them at almost any point in their course. The various parts of the sym-
pathic are intimately associated with each other and also with the cerebro-spinal nervous
system. So close is this connection that some authors consider the sympathic as _belong-
ing to the peripheral part of the cerebro-spinal system (Quain, A, I, 519).

There are nominally as many pairs of sympathic ganglia as vertebra, except in the
cervical region and rarely also in other regions. From each ganglion passes a branch to
the corresponding spinal nerve (Fig. 107, 109).

§ 1048. Specimen, Preparation and Dissection.—The same
specimen may be employed as for the vagus, and it should be pre-
pared in precisely the same manner (§ 1030). The exposure is also
the same, and the method of dissecting the nerves (§ 1081).

Nearly dorsad of the ganglion of the root of the vagus is the
similar, fusiform, superior cervical ganglion of the sympathic. It
may be carefully isolated ; then, by carefully tearing the sheath of
the combined vagus and sympathic, the two may be separated in
the neck. About 1 cm. from the 1st rib the sympathic inclines lat-
erad, and very near it there appears in most subjects a small gan-
glion, the thyroid or middle cervical ganglion (Fig. 107, Ging.
thyr., Fig. 108). Pull the nerve, and it will be found to divide
into two parts, one of which passes dorsad and the other ventrad of
the A. subclavia (Fig. 109). Cut the axillary artery and turn it
mesad. The two nerves may then be followed to their termination
in the ganglion vertebrale or the inferior cervical ganglion just
caudad of the 1st rib (Fig. 107, Gng. vert., 108, 109). Pull upon the
nerve and make out the branches passing from this ganglion. They
are shown in Fig. 107, 108 and 109. After these branches are
traced, tear away the pleura and follow the sympathic chain along
the thorax. Note that there is a ganglion for each vertebra, and
that each ganglion communicates with the corresponding spinal
nerve (Fig. 107).

§ 1044. NN. splanchnici.—The sympathic ganglion about oppo-
site the last rib is somewhat larger than those preceding it, and there
is given off a branch, the WV. splanchnicus major, which passes
caudad and slightly ventrad and penetrates the diaphragm. The |
diaphragm should be cut, the abdomen well opened and the viscera
turned to the right; then by pulling upon this nerve it will be seen
to move the semilunar ganglion, showing that it joins that body.
Now follow the sympathic from the origin of the great splanchnic.
It becomes more nearly mesal in position, and when near the dia-

396 ANATOMICAL TECHNOLOGY.

phragm gives off another branch, the VV. splanchnicus minor. This
also penetrates the diaphragm and joins the semilunar ganglion
(Fig. 90, 107).

§ 1045. Ganglion semilunare (Fig. 90, 107).—The semilunar
ganglion belongs to the so called solar plexus of nerves, a network
of nerves formed partly from the vagus (§ 1041), but mostly from
the sympathic. The ganglion is a slightly pinkish body situated
laterad of the origin of the superior mesenteric and celiac arteries,
as shown in Fig. 107, and very near the adrenal body. It is quite
tough, and when grasped and pulled the nerves may be seen spread-
ing out in all directions like the rays of the sun.

§ 1046. The abdominal sympathic.—In order to follow the
sympathic in the abdomen, the blood vessels should be removed.
The nervous cords of the two sides closely approach each other, so
that both may be traced at once.

The caudal part of the sympathic is partly shown in Fig. 107, A,
and directions for tracing it are given under the preparation of this
figure.

Preparation of Fig. 109.—The arteries were injected with red and the veins with blue
plaster ($§ 362, 363). The sternum was removed, and the thyroid and vertebral ganglia
of the sympathic and their branches isolated as directed above (§ 1008) The thyroid gan-
glion of the right side was displaced somewhat dextrad, the vertebral ganglion of the left
side drawn dorsad, and the muscles removed from the vertebra and the pleura and con-
nective tissue from the other parts. The cesophagus was slightly distended with cotton
and the two roots of the myelonal nerves slightly separated and held apart with cotton.
The preparation was hardened and preserved in alcohol (§ 286).

Explanation of Fig. 109.—A. sbclv. sin., A. subclavia sinistra. A. sbclv. dext.,
A. subclavia dextra—The right subclavian is shown in two places as if it were double ;
the artery is not double, but is shown in its natural position and also displaced in order to
more clearly indicate the ring of the sympathic (ans@ s. annulus Vieussenit) surrounding
it; see Fig. 108 and Foster, A, Fig. 37. A.c., A. carotidea (§ 900). A. sternalis—On the
left the name is written on the artery. A. thyr., A. vertebralis—By an inadvertence the
wrong abbreviation was used. The artery is shown on the right dorsad of the origin of
the A. sternalis.

Alba—The white substance of the myelon. It is dotted to indicate the cut ends of
nerve fibers (§ 1048).

Cn. centralis—The central canal of the myelon; see Chapter X, Fig. 112, A.

Centrum—The centrum or body of the 2d thoracic vertebra (§ 462).

Cinerea—The gray or ganglionic substance of the myelon (§ 1047). It is left white in
the figure, and appears something like a letter H in the interior of the myelon (§ 998).

F. dms., Fissura dorsimesalis—The dorsimesal (posterior) fissure of the myelon.

F. vms., Fissura ventrimesalis—The ventrimesal fissure of the myelon. It is directly
opposite the dorsal fissure, and the two divide the myelon nearly in half (§ 998).

TRANSECTION OF THE THORAX. 397

Gng. thyr., Ganglion thyroideum—The thyroid or middle cervical ganglion of the
sympathic (Fig. 107, 108, § 1048).

Gng. vrt., Ganglion vertebrale—The vertebral or inferior cervical ganglion of the
sympathic (Fig. 107, 108, § 1048).

Myelon—The myelon or spinal cord is the part of the central nervous system situated
within the neural canal (Fig. 104, § 479).

MM. lg. colli—The longus colli muscles.

N. thr. (1st)—The first thoracic or dorsal nerve. The abbreviation is written on the
ventral primary division, Centrad of the abbreviation, the dorsal primary division is seen

Fie. 109.—TRANSECTION OF THE THORAX, SHOWING THE ORIGIN OF A PATR OF SPINAL
NERVES AND THE RELATIONS OF THE SYMPATHIC AND CEREBRO-SPINAL SYSTEMS ;
CEPHALIC VIEW; x 1.5.

to join the ventral, and the trunk is formed by the union of the dorsal and ventral nerve
roots from the myelon (§ 1007).

N. thr. (2d), N. thoracicus (2d)—The second thoracic nerve, showing the ramus com-
municans connecting it with the vertebral ganglion.

N. sym, (cd.) 1, N. sympathicus (caudalis)—The sympathic nerve extending caudad
of the vertebral ganglion in the thorax (Fig. 107, § 1042).

Ramus communicans 2—The communicating branch between the vertebral ganglion
of the sympathic and the 2d thoracic myelonal nerve.

398 ANATOMICAL TECHNOLOGY.

Ramus communicans 3—The branch or ramus connecting the vertebral ganglion of
the sympathic with the 1st thoracic myelonal nerve.

Rm, crv. 4 (7), Ramus communicans cervicalis ('7th)—The branch connecting the
7th cervical nerve with the vertebral ganglion.

N. crd. 5, Nervus cardiacus minor—The lesser cardiac nerve from the vertebral
ganglion. The heart receives several filaments from the vertebral and thyroid ganglia,
but only this large one is shown.

N. sym. (cph.) 6, N. sympathicus (cephalicus)—The sympathic nerve extending
cephalad of the thyroid ganglion along the neck. It is somewhat displaced to the right ;
see Fig. 107.

N. sym., N. sympathicus—The cut end of the sympathic nerves of the two sides,
showing their relations to other parts. That of the left side (1. sym.) is on the left of the
corresponding carotid artery, while the one on the right (W. s.) is dorsad of the right
carotid and very close to the vagus.

N. v., N. vagus—The cut ends of the vagus or pneumogastric nerves, showing their
relations.

N. phrn., N. phrenicus—The cut ends of the phrenic nerves, showing their relations
to the other structures.

CEs., Esophagus (Fig. 108, 107, § 798)—The cesophagus is seen to be somewhat to
the left of the meson and dorso-sinistrad of the trachea. It is represented as somewhat
contracted, hence the wavy outline of the mucous membrane.

Rx. et Gng. dorsalis, Radix et Ganglion dorsalis—The dorsal (posterior) root of
the 1st pair of myelonal nerves with its ganglion. (The adjective dorsalis belongs only to
radix, hence the feminine form.)

Rx. vnt., Radix ventralis—The ventral (anterior) root of the 1st pair of myelonal
nerves (§ 1007).

Spina neu. thr. (2), Spina neuralis thoracica (2)—The 2d neural thoracic spine.

Trachea—The trachea is represented as slightly contracted so that the cartilaginous
rings overlap somewhat.

VV. breph., VV. brachio-cephalice—The cut ends of the two brachio-cephalic veins
(Fig. 101, § 922).

§ 1047. Obvious Structure of Nervous Tissue.—Nervous tissue is obviously of two
kinds :—(A) Alba (white matter). This is found in the central nervous system, where it
has a dense, lusterless white appearance, but principally in the nerves (§ 995), where it is
white and glistening; the nerve also has a wavy or crimped appearance when relaxed.
The nerves themselves have something of the same obvious structure as striated muscle
(§ 704), that is, a more or less cylindrical fasciculus, surrounded by a sheath (epinewrzum),
and this mass in turn being composed of smaller bundles (fundewli) each funiculus having
its special sheath ( perineurium, neurtlemma).

(B) Gray matter. The gray nervous matter is soft, so that it is easily crushed in the
hand ; in color it is of a delicate gray or reddish brown, and is collected in masses (§ 994),
the largest being in the brain and myelon (§ 997).

§ 1048. Microscopic Structure of Nervous Matter.—(A) White matter (alba), Each
funiculus, like the fasciculus of a striated muscle, is composed of a variable number of cyl-
indrical fibers which are of two kinds:—(1) Medullated, composed of three parts, viz., a
primitive sheath somewhat comparable to the sarcolemma of the muscle fiber ($ 705) ; it
has a wavy outline and presents nuclei: Myeline or white substance of Schwann, this isa
white fatty substance just within the primitive sheath ; it isinterrupted at regular intervals

STRUCTURE OF NERVOUS MATTER. 399

(1-2 mm.), forming the nodes of Ranvier: Avis band, band axis, axis cylinder ; this forms
the central part of the nerve fiber; it is continuous, subcylindrical, grayish, rather tena-
cious, finely fibrillated and with straight outline. The axis cylinder is the essential part
of the nerve, and is the only part found at its origin and termination. Medullated nerves
neither give nor receive anastomoses except very near their termination. In cross sec-
tion, a bundle of nerve fibers appears like a bunch of lead pencils, the band axis corre-
sponding to the lead. (2) Non-medullated fibers. These are of a pale gray appearance,
owing to the absence of the myeline. They possess a nucleated sheath and an axis cylin-
der like the medullated fibers, but differ from them in the absence of the medullary sheath
and from the fact that they anastomose frequently throughout their entire course ; Ran-
vier, A, 776.

(B) Gray matter. Gray matter is composed of an interlacing network of nerve fibers,
peculiar connective tissue (neuroglia) and nerve cells, the latter being the characteristic
feature. The nerve cells of the brain and myelon apparently possess no proper sheath,
and present two forms, viz., (1) cells containing a nucleus and nucleolus, surrounded by
the gray or reddish brown protoplasm which gives off one or more processes, giving rise
to the so called multipolar cells, one or more of the poles being continued as the band axis
of a nerve fiber; (2) cells much smaller than the preceding, composed apparently of only
a nucleus and nucleolus. The nerve cells of the ganglia possess a proper sheath, which
is merely an expansion of the primitive sheath of a nerve fiber. Typically, these cells
are pyriform and possess a pole at each end which is continued into a nerve fiber.
Stricker, A, 116; Quain, A, II, 126.

CHAPTER X.
ENCEPHALON—THE BRAIN.

GENERAL CONSIDERATIONS—NAMES OF THE PRINCIPAL PARTS OF THE AMPHIBIAN BRAIN
—DIAGRAMS OF AN IDEAL SIMPLE BRAIN—EXAMINATION OF THE BRAINS OF THE
FROG AND MENOBRANCHUS—REMOVAL OF THE CAT’S BRAIN—MACROSCOPIC VOCABU-
LARY—DESCRIPTION OF FIGURES AND PLATES— DISSECTION OF THE BRAIN—
SYNONYMS AND REFERENCES—FISSURES AND GYRI.

§ 1049. General Considerations.— Definition.—Excluding Am-
phioxus, whose brain is peculiar and apparently incomplete, the
vertebrate encephalon may be defined as the enlarged, differenti-
ated and incompletely segmented cephalic portion of the myelen-
cephalon (cerebro-spinal axis), contained within the cranium.

The junction of the brain proper with the myelon proper (§ 1006, Fig. 104) is formed
by the part commonly called meduila (oblongata), but metencephalon by Quain (A, II, 755),
and in the present work. By its obvious characters and real structure the medulla is
only a modified continuation of the myelon (Stricker, A, 758-764, Spitzka, 7, 46), and
Wyman describes it (34, 7) as a division thereof; most writers, however, regard it as a
part of the brain, and this is practic7//y the more convenient way.

§ 1050. Importance and Difficulty of the Study of the Brain.—An acquaintance with
the obvious features, the intimate structure and the functions of the brain is desired by
not only the physician and the practical veterinarian, but also by the systematic zoologist,
the comparative anatomist, the physiologist and the psychologist.

The nature and extent of the obstacles to the acquisition of this knowledge are most
fully appreciated by those who have advanced the farthest in its pursuit ; some idea of
them may be gained from any recent compendium by an original investigator in either
of the branches of inquiry above indicated (Quain, A, II; Stricker, A; Ferrier, A).

Deferring for the present any considerations of the histology and functions of the
mammalian brain, its mere topography is far from easy to understand.

§ 1051. Methods of Studying the Brain.—The brain is com-
monly figured and described as a fibrous and cellular mass pene-
trated here and there by inconsiderable cavities. Little attention is
paid to the membranes which line these cavities and invest the
entire organ. Stress is laid upon its complex structure and remark-

eh eae eee

METHODS OF STUDYING THE BRAIN. 401

able functions. Finally, the human brain is usually presented, or
at least employed as a standard for comparison.

From personal experience and from the uniform testimony of
our students, we have been led to the following conclusions :—

(A) The arrangements of the solid parts of the brain are more
readily perceived and more easily remembered after the relations
of the cavities are fully understood.

(B) An adequate idea of the circumscription of the cavities in-
volves a distinct recognition of their lining and of the investment of
the whole brain.

(C) The general plan of the organ is most readily appreciated if
we disregard altogether its organic composition and its direct sub-
servience to mental operations, and view it primarily as we might
any artificial structure, like a house or a piece of furniture of homo-
geneous material.

(D) Even if, as is commonly the case, the human brain is the
ultimate object of inquiry, the brain of some Amphibian should b
examined first.

§ 1052. So far as we know, the first three of these propositions have not been distinctly
enunciated heretofore.

The advantage of studying first the cavities of the brain seems to arise from the fact
that while the walls are subject to great modifications as to form, thickness, histological
composition and connections, the cavities can present differences of only size, shape and
degree of circumscription ; their connections are invariable, and of course no structure is
predicable of them. Hence fewer considerations are presented to the mind, a matter of no
small importance to the beginner.

§ 1053. To the physiologist the membranous envelopes are of interest only as con-
cerned in the vascular supply of the proper nervous tissue, and for most anatomical
purposes they are better removed. With them, however, are apt to come away some
atrophied parts of the parietes together with the lining of the cavities, so as to leave the
latter open at certain points. Hence many figures and descriptions indicate or imply that
there are free communications between the cavities and the outside of the brain.

With possibly a single exception (§ 1082), this is not the case, in adults at least, and
indeed the existence of such communications would be out of keeping with what is known
of the mode of development of the organ. Hence any clear and adequate conception of
the relations of the cavities involves the distinct recognition of the presence of the mem-
branes and of their general arrangement.

§ 1054. As to the third proposition, the comparative anatomist and the systematic
zoologist especially desire the identification of the various regions of the brain, and the
determination of suitable names and terms for description, Even where the histology
and functions of the organ are the ultimate objects of its study, the student must first
become familiar with the order of succession of the parts, their constant topographical
relations and the connections of their cavities, and with the names of them all.

Now this may be done not only as well, but in our opinion more easily, if all other

26

402 ANATOMICAL TECHNOLOGY.

features are for the time ignored, and the brain is viewed simply as a series of cavities with
parietes of varying thickness, more or less distinctly divisible into walls, floor and roof.

§ 1055. The fourth proposition is in accordance with the following general aphorism :—

“Tn all departments of investigation, it is right to commence with the study of that
which is common, simple and regular, and thence to proceed to inquire respecting that
which is [complex], unusual and irregular.” Bucknill and Tuke, A.

The specific idea is admirably expressed in the following passage from a paper in
which it is practically carried out :—

“ With man and the other mammals, the cerebrum and cerebellum so far transcend
all the other organs of the encephalon, that the parts which in a morphological point of
view are of equal value have been frequently overlooked, as forming either integral parts
or primary subdivisions.

“In frogs . . . while no one part takes an excessive development, there is at the same
time no one of the fundamental ones either wholly deficient or so far reduced as to deprive
the general plan of any of its more important features. The brain is so far reduced in the
relative proportion of its different parts, and so far stripped of the ‘ accessory organs of per-
fection,’ as to enable the student to obtain with ease a clear conception of the general plan,
a conception always so difficult to acquire when studying the brain of mammals or of
man.”—Wyman, 34, 6.

§ 1056. The advantages presented by the frog’s brain may be categorically stated as
follows :—

(1) The various parts, while far from equal in size, differ much less than in the higher
Vertebrates.

(2) No part is completely hidden by another.

(3) All lie in the same plane, the organ not presenting the perplexing “ cranial flex-
ure” (Quain, A, II, 733) of most of the higher Vertebrates.

(4) The cavities are relatively large.

(5) The parietes vary little in thickness.

(6) While all the primary components of the brain are present, there are but few spe-
cial additions or modifications to distract attention from the general plan.

Yet the frog’s brain is by no means an ideally perfect type of the vertebrate brain, or
Wholly adapted for study, for the following reasons :—

(1) It is undesirably small. Hence the student should select for this purpose the very
largest individuals, if possible of the bullfrog, Rana Catesbiana (pipiens of some writers).

(2) The tissue is very soft. Hence great care is needed, and the organ should usually
be hardened.

(3) The cerebellum is disproportionally small.

(4) The cavity of the optici presents a projection of the wall which renders a section of
the region somewhat puzzling.

(5) The passages ( pori@ or foramina of Monro) between the mesal and the lateral cavi-
ties are undesirably small.

(6) The cephalic divisions, the Lobi olfactorit, which are separate in all other Verte-
brates, are, in the frog and toad and other anourous Amphibia, not only in contact upon
the meson, but there united by somewhat firm connective tissue, constituting a feature
which has seriously misled some anatomists, including even Wyman (34, 8, 9).

(7) The plexuses are nearly or wholly absent.

In respect to the last four objections, the brain of Menobranchus is preferable to that
of the frog. But the animal is less easily obtained, the cerebellum is even smaller, and the
optici are so slightly differentiated from the parts caudad and cephalad as to render some-
what difficult the recognition of their limits. .

PRINCIPAL PARTS OF THE AMPHIBIAN BRAIN. 403

Nevertheless, the brain of Menobranchus is well worthy of examination upon the fol-
lowing grounds :—

(1) The slight differentiation of the regions is an interesting reminder of the presumed
condition of all brains at an early stage of development.

(2) The size of the cavities and communications and the thinness of the parietes permit
the effects of inflation with air to be at once apparent.

(3) The Lobi olfactorii are disconnected, as in all Vertebrates excepting the Anura.

(4) The avila is large and well defined.

§ 1057. The method of viewing the general constitution of the brain which was sug-
gested by Wyman and is herein adopted may be called the comparative anutomy way. There
is another, the embryological way, which is theoretically more satisfactory and complete,
but practically not well adapted to beginners. It would be well, however, for the some-
what advanced student to obtain a collection of foetal pigs, kittens, etc., of different ages,
and carefully expose their brains so as to observe the gradual increase of the hemispheres
and cerebellum, the formation of the gyri and the progressive thickening of the walls in
the greater part of their extent. :

§ 1058. Partial Vocabulary.—The following List includes only -
the names of the principal parts of the Amphibian brain. A more
complete macroscopic vocabulary of the organ will be given later in
this chapter.

Names of the Principal Parts of the Amphibian Brain, with
their more Common Synonyms.—Aula—YV entricle of the “ unpaired
cerebral rudiment.’ Aulatela—Atrophied or membranous roof of
aula. Auliplexus—Plexus choroideus aule. Cerebrum—Hemi-
sphere, larger portion of prosencephalon. Cerebellum—Dorsal
portion of epencephalon. Chiasma—Commissura optica, chiasma
nervorum opticorum. Conarium—Corpus pineale, pineal gland,
epiphysis. Crus cerebri—Floor of mesoccelia. Diaccelia—V entric-
ulus tertius. Diencephalon—Deutencephalon, thalamencephalon.
Diaplexus—Plexus choroideus ventriculi tertii. Diatela—Atro-
phied or membranous roof of third ventricle. Endyma—Ependyma,
lining of the ceelie. Epiccelia—Ventriculus cerebelli, cephalic part
of ventriculus quartus. Epencephalon—Hind brain. Hemisphera
—Hemicerebrum. Hypophysis—Corpus pituitarium. Lobus olfac-
torius—Lateral half of rhinencephalon. Mesencephalon—Lobi
optici and crura. Mesoccelia—Ventriculus loborum opticorum,
aqueductus Sylvii, iter a tertio ad ventriculum quartum. Meta-
coelia—Caudal portion of ventriculus quartus. Metatela—Atro-
phied or membranous roof of ventriculus quartus. Metencephalon
—Medulla. Myelon—Chorda spinalis. Opticus—Lobus opticus.
Pia—Pia mater. Porta—Foramen Monroi. Portiplexus—Plexus
choroideus foraminis Monroi. Postcommissura—Commissura pos-
terior. Precommissura—Commissura anterior. Proccelia—Ven-

404 ANATOMICAL TECHNOLOGY.

triculus lateralis. Proplexus—Plexus ventriculi lateralis. Prosen-
cephalon—Cerebrum, hemisphere. Pseudo-commissura—Connec-
tive tissue between lobi olfactorii in Anura. Rhinencephalon—Lobi
olfactorii. Rhinoccelia— Ventriculus olfactorius. Terma—Lamina
terminalis, lamina cinerea. Tuber cinereum. Thalamus—Thala-
mus nervi optici, wall of diacelia. Walvula—Valve of Vieussens.

§ 1059. List of some of tie Technical Names of the Parts most frequently mentioned,
with the terms (in black letter) which are Preferred to them—Aqueductus Sylvii—Meso-
celia. Chorda spinalis—Myelon. Commissura anterior—Przcommissura. Commis-
sura posterior—Postcommissura. Corpus pineale—Conarium. Corpus pituitarium—
Hypophysis. Ependyma—Endyma. Foramen Monroi—Porta. Iter a tertio ad ven-
triculum quartum—Mesoceelia. Lamina terminalis s. cinerea—Terma. Lobus opticus
—Opticus. Medulla oblongata—Metencephalon. Pedunculus cerebri—Crus cerebri.
Plexus choroideus ventriculi tertii—Diaplexus. Plexus choroideus ventriculi lateralis—
Proplexus. Ventriculus lateralis—Procelia. Ventricle of the “ unpaired cerebral rudi-
ment,” mesal part of ventriculus lobi communis—Aula. Ventriculus quartus—Meta-
celia. Ventriculus tertius—Diacelia.

Comparative Brevity of the Terms here adopted.—In the above list there are 19 new names
composed of 20 words and about 150 letters. . The corresponding old names comprise 40
words and about 300 letters. Since the parts specified are very frequently mentioned in
treating of the macroscopic anatomy of the brain, it is evident that a substantial saving is
effected by the employment of the shorter terms.

§ 1060. The Hncephalic Segments.—All brains present more or
less marked constrictions with intervening enlargements ; the caudal
region also is single or mesal, while the cephalic is double or in two
lateral parts. Hence the brain may also be defined as an incom-
pletely segmented tube of nervous tissue, bifurcated at one end.

In each of these segments there is one organ or pair of organs
constituting its principal or characteristic portion, but there are
always some other parts of greater or less importance.

§ 1061. Names of the Encephalic Segments.—That region of the
brain which includes the (lob7) optici, which is easily recognized in
most adults and is very prominent in the embryo, has been almost
uniformly designated by the technical term mesencephalon, or by
its vernacular equivalents mittelhirn or midbrain.

With regard to all the other segments, however, there has been
such diversity of usage that the student is apt to be confused in
comparing the statements of different writers. In the following
Table are given the principal synonyms of the names or the ence-
phalic segments herein adopted, which, as may be seen by compar-
ing the second and seventh columns, are almost identical with those
which are given in the Human Anatomy of Quain (A).

405

NAMES OF THE ENCEPHALIC SEGMENTS.

NAMES AND SYNONYMS OF THE ENCEPHALIC SEGMENTS.

‘ . Von Baer (1)
ries, Herein employed ’ : Huxley (A, 56-59); e
Principal : 4 yes) (A, II, 106) English | Owen (A,-I, 277 ; yee 7 Heckel (A
and Wilder, 9 satetet re 3 sad >| Lankester (2), (Geg. uain (A, IT, 755). Spitzka (6, 27). 7 ’
Organs. 125: 14, 539.” an t. German Vernacular. | 294; II, 79-81.) | Pani], A. p. xiil) Q , Ii, P ’ II, £20).

; + : Vorderhirn Forebrain * Rhinencephalic part| { Rhinencephalic_ part | { Prosencephalon| ) Protopsyche
Lobi olfactorii.| Rhinencephalon. | et part) pte } Ai art) t we hate cutis (3) | a peeenenn on. { sok pepeceoncihaen (4) | e (in pars ae } = (in pact

: orderhirn orebrain rosencephalon rosencephalon osencephalon pro- rosencephalon rotopsyche
Hemisphere ...! Prosencephalon . : (in part).... | (in part)... (in part)........ { POPOL 23.0055 cas | POPS ciao. oa onceue et } (in part)...... | (in part).
Thalami. . ...| Diencephalon (5).| Zwischenhirn .|’T'weenbrain.. Pee Tec nee a {, Diencephalon i ye dapat | Deutopsyche,
Lobi optici. ....| Mesencephalon..| Mittelhirn.....| Midbrain.....| Mesencephalon....| Mesencephalon......| Mesencephalon........| Mesencephalon ..| Mesopsyche.
Cerebellum.....| Epencephalon ...| Hinterhirn ... | Hindbrain... 7 5 LT a | Metencephalon ..++.| Epencephalon ........./4P ly een a } catty che
Medulla ........] Metencephalon ..| Nachhirn......| Afterbrain... } ard “— os \ Myelencephalon (10) Metencephalon ........ ri tenet. | Bpipsyche.

(1) Not having had the opportunity to consult the work of Yon Baer, we ascribe to him the original application of the segmental names in accordance with
the statements of Reichert (A, II, 15, note), and Mihalkovics (A, 22, note). These German vernacular names are used by Gegenbaur and other writers in that
language.

(2) The English editor of Gegenbaur (Gegenbaur [Lankester], A, xiii) adopts Huxley's nomenclature, notwithstanding his admission of the priority of the
arrangement in ‘* Quain.” :

(3) Although practically it may not be often necessary to use the term rhinencephaion, the recognition of the lobi olfactorii may be urged upon grounds like
those in the case of the hemispheres which are the result of a secondary division of the primary anterior cerebral vesicle (§ 1062).

(4) Rhinencephalon is given as a synonym for “ olfactory bulb.”

(5) The term diencephalon is used by Rolleston (A, p. xxxvi), but we do not know who first proposed it; even if antedated by ¢haiamencephaion and deuten-
cephalon, its brevity should insure its acceptance.

(6) Itis alittle odd that Owen should ignore the almost universally recognized segmentation of the hemispheres from the thalami, while at the same time,
rightly as we think, recognizing the olfactory lobes as a separate division.

(%) Diencephaion is given by Quain as a synonym.

(8) In place of the vertical division usually made, Owen makes a horizontal one between the dorsal cerebellum and the ventral ‘‘ medulla,’’ which he names
macromyeion, applying to the entire region caudad of the mesencephalon the name epencephalon.

(9) Aside from the undesirable substitution of a metaphysical term for the anatomical one, Heckel has, if rightly translated, caused needless confusion by
reversing the usual order of the Greek equivalents for hinter and nach.

(10) Since Owen had previously employed the term myelencephaion as a single equivalent for the phrase axis cerebro-spinalis, it was very unfortunate that the
same word should be applied by Huxley to a part thereof.

406 ANATOMICAL TECHNOLOGY.

§ 1062. Unequal Morphical Value of the Segments.—So far as appears in the second
column of the Table, the six segments are equal primary divisions.

In one sense this is certainly not the case. According to most accounts (Reichert, A,
II, 11; Mihalkovies, A, 21; Spitzka, 6, 27; Huxley, A, 56; Quain, A, II, 750), the
embryonic brain consists of three primary vesicles ; of these the middle is developed into
the mesencephalon, while each of the others is again divided into secondary vesicles, from
which the other five regions are formed. Balfour, however (A, II, 345), admits only two
primary vesicles.

Aside from the verbal distinctions indicated in the Table, most of the differences are
due to the unequal estimates placed by writers upon the several segments from an embryo-
logical point of view.

Anatomically, there seems to be no objection to the arrangement here adopted, for
while the cerebellum and hemispheres preponderate in the higher animals, the optic lobes
are larger in some “‘ fishes,” the olfactory lobes are enormous in some sharks and placed
at a considerable distance from the prosencephalon, and in a skate ( Torpedo) the largest
part of the brain is the medulla.

For practical purposes, then, the six segments may be regarded as codrdinate divisions.

§ 1063. Advantages of Using the Segmental Names.—There are three advantages in
the use of terms designating the encephalic segments :—

(1) They indicate the segmental constitution of the brain.

(2) Each designates a general region which may consist of several more or Jess distinct
parts. Mesencephalon, for example, includes not only the optic lobes, but the cruru
cerebri, etc.

(8) They are single words capable of inflection,

§ 1064. Names of the Cavities.—On account of the peculiar condition of things in man
and the higher Mammals, certain portions of the general cavity have been recognized as
such, while others have been called passages or ignored altogether. In modern times ihe
larger cavities have been usually called ventricles, from the Latin ventriculus.

The incongruity of the anthropotomical designations of the encephalic cavities has
been pointed out by Owen (A, I, 294, note), and the senior author (9, 125, 14, 539).

The canalis centralis expands into a cavity which, although the first of the series, is
called the fourth ventricle. The more or less distinct cavities corresponding to the cere-
bellum and the optici are not called ventricles at all; and the second is known by either of
the following phrases: agueductus Sylcii and iter a tertio ad ventriculum quartum. The
diencephalic cavity is the third ventricle. The two “ lateral” ventricles are rarely men-
tioned as the first and second, but since the numbers must be understood in order to account
for the third and fourth, the student desires, in vain, to know which is the first and which
the second. In point of fact, if the enumeration is begun at the cephalic end of the series,
the lateral ventricles are the third and fourth, since, in most air-breathing Vertebrates,
there are well-developed ventricles in the Lobi o/factorii. Finally, a “‘ fifth ventricle ” is
mentioned, which is not only at a great distance from the fourth, but has no normal con-
nection with the other ventricles, and is, in fact, no part of the series.

It is hardly possible to imagine less appropriate and consistent appellations for a series
of essentially similar cavities.

Ventriculus is objectionable because of its length, because its use is apparently estab-
lished in connection with the cardiac cavities, and because, as a Latin word, it is not readily
combined with Greek prefixes. No one of these objections is fatal, but combined they may
be regarded as warranting the use of another word if such can be found,

a eae

NAMES OF THE ENCEPHALIC CAVITIES. 407

The Greeks designated either a cardiac or an encephalic cavity by the name xo:Aia, and
the senior author has proposed (9, 125, 14, 540) to substitute it for ventriculus, and to des-
ignate the several encephalic cavities by terms formed by its combination with the charac-
teristic prefixes of the encephalic segments. This gives us rhinocalia, proceliu, diacelia,
mesocelia, epicwlia and metacwlia. These terms are capable of inflection, and the longest
of them is no longer than the Latin ventriculus, which requires a prefix or qualifying
word. Finally, when the student has once learned the order and significance of the names
of the encephalic segments, he has only to acquire a single term and apply thereto the char-
acteristic prefixes with which he is already familiar.

§ 1065. Aula and Porta.—These names were proposed by the senior author (5, 9, 14,
540) upon the following grounds :—

(1) To substitute brief single words for the phrases: “ventriculus communis,” “ ven-
triculus lubi communis,” cavity of the “ cerebral rudiment,” unpaired hemisphere vesicle
or “secondary forebrain,’ mesal part of the ‘‘common ventricular cavity,” foramen
Monroi, etc.

(2) Because the phrase most commonly employed, foramen Monrdi, is used to designate
at least three different cavities or orifices: (A) The cavity by which either proccelia com-
municates with the mesal series of ccelie ; (B) the two lateral orifices together with the
intervening space; (C) the mesal (cephalic) orifice of the diaccelia. We have been unable
to ascertain by whom the phrase was first employed, and the description by Monro secun-
dus (A, 12-16), in whose honor it was applied, is somewhat vague (Wilder, 3).

(83) In order to indicate our opinion of the desirability of recognizing the aula as mor-
phologically an important element of the ccelian series.

§ 1066. Tele und Plexuses.—The atrophied or membranous roofs of certain cceliz are
called tela vasculosa or tela choroidea, superior, inferior, etc., and the vascular plexuses
formed by them are designated as plexus choroideus ventriculi tertii, etc. If once the
general names for the encephalic segments and ccelie are adopted, we have only to employ
the characteristic prefixes and gain the single and definite names metute/a, diatela, aula-
tela, metaplexus, diaplerus, auliplexus, portiplexus and proplexus.

§ 1067. Comméissure.—Of the bands of fibers, or aggregations of cells and fibers, by
which the parts of the brain—especially corresponding parts upon the two sides—are con-
nected, some are called commissures, while others have received special names. These
latter—callosum, fornix, pons and chiasma—are retained, but the other three—as proposed
by the senior author (9, 126, 14, 538)—are here simplified by prefixing to the word com-
missura the syllables pre, post and medi.

§ 1068. Tabular View of the Encephalie Segments and their parts in the Amphibian
Brain.—The accompanying Table contains the names of the principal parts of the brains
of the frog and Menobranchus arranged according to the segments which they constitute
(Fig. 110-112). Attention is called to the recurrence of the prefixes characterizing the seg-
ments in the names of the corresponding celia, tele and plexuses (§ 1066). A somewhat
similar table is given by Mihalkovies (A, 48), including also the names of the parts of the
mammalian brain ; see also Quain (A, II, 755).

The abbreviation az. indicates that the part is azygous or unpaired ; the rest are lateral
and paired.

408

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ANATOMICAL TECHNOLOGY.

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Fie. 110-112.—Scuematic DIAGRAMS OF A SIMPLE BRAIN.

AN IDEAL SIMPLE BRAIN. 409

§ 1069. TABULAR ARRANGEMENT OF THE NAMES OF THE PRINCIPAL
PARTS OF THE AMPHIBIAN BRAIN.

Segmenta. Cavitates. Parietes. Commissure et Plexus.
Rhinencephalon,) Rhinoceelia.., Lobus olfactorius........ Pseudo-commissura, az.
gs { Cephalic por- ; ?

s tion, paired. Proceelia...; Hemisphzra...... ....... rece rea

a

o 4

= . : { Proplexus

a 9) sid He pia ga - Hemispineta » ASAE ey } Portiplexus.

o ined r ‘ate rak Aulatela (roof), az.......| Auliplexus.

ae eee wer ave pegea hh irebas (end and floor), az.| Preecommissura, az.
Thalamus (wall).........| Postcommissura (roof), az.
Diatela (roof), az........ Diaplexus.

Diencephalon. ..| Diaccelia, az. Conarium (roof), aa.

Tuber cinereum (floor), az.| Chiasma (floor), az.
: Opticus (roof and wall)...
engine Valvula, in part (roof), az.
Crus (floor),
«mali Cerebell , 2.
Epencephalon . .| Epiceelia, az. / Waleutis ax hate ser em

Metaccelia,) | Metatela (roof), az....... Metaplexus, az.
i Medulla (wall & floor), az.

Mesencephalon.

Metencephalon..

|

§ 1070. An Ideal Simple Brain.—In accordance with the gen-
eral plan of this work and the propositions given above (§ 1051),
the examination of the actual brains of the frog and cat may be
advantageously prefaced by the careful study of the preceding dia-
grams (Fig. 110-112), which present to the eye certain essential and
fundamental facts.

Fig. 110-112. Schematic Diagrams of an Ideal Simple Brain.—Fig. 110—Longi-
tudinal dextro-sinistral section, showing the relations of the cavities, the sequence of the
encephalic segments and the relations of the ceelie.

Fig. 111—Mesal aspect of the right half after hemisection, showing the contour and
constitution of the ccelian floors and roofs.

Fig. 112—Transection of several segments, showing the ccelian parietes.

§ 1071. Comments upon the Diagrams of the Brain.—Aside from the prominence given
to the aula, these diagrams, so far as they are correct, convey no information or ideas not
already the common property of neurologists; they are intended merely as visual aids to
the student in the somewhat oncrous task of learning the sequence of parts and associating
the names therewith.

They do not accurately represent the actual condition of things in any known brain at
any stage of development. They correspond most closely with the brains of the frog and
Menobranchus, but differ from the former in the disjunction of the Lobi olfactorii, from

410 ANATOMICAL TECHNOLOGY.

the latter in the greater differentiation of the segments, and from both in the subglobular
form of the right hemisphere.

All that is shown, however, might really exist in a brain without contravention of our
general knowledge of the structure and development of the organ ; hence, even if consid-
erable modification of detail should be required, such diagrams would still be useful as
an elementary introduction to the study of the brain.

At the outset the student will do well to regard the diagrams as purely geometrical
figures or as representing hollow masses of wood or iron. The shading is conventional,
and intended to be uniform excepting with the three nerves of special sense in Fig. 110.
No attempt is made to indicate the difference between the true nervous parts and those
(conarium and hypophysis) which may consist of very different material, between the fibrous
and cellular portions of the nervous tissue, or between the longitudinal and transverse
fibers of the former.

The names, however, are of course those which apply to the various parts of the real
brain. ‘They are usually written in full upon or near the parts, but in Fig. 112, A, anda
few other cases, abbreviations are employed upon one or both sides of the symmetrical
figures.

The idea of diagrams like Fig. 110,111, was derived from the very clear and suggestive
views of the typical brain given by Huxley (A, Fig. 19, 20); the only diagrams known to us
comparable with those in Fig. 112 were published by the senior author (22, Pl. IIT), but
the membranes were not included. The transections of the frog’s brain given by Stieda
(22, Taf. XVIII) are of actual sections and likewise omit the membranes,

§ 1072. Fig. 110—Horizontal Section.—This affords the most complete view of all of
the encephalic cavities (cceliz) and of their relations to each other and to the segments of
the organ. ;

‘The ceelie form two series, mesal and lateral. The mesal ccelie are direct continua-
tions of the canalis centralis of the myelon, and open through the porte into the lateral
ceeliz on either side.

The walls of the ccelize are made continuous and of nearly uniform thickness ; in gen-
eral the two sides are similar, but those of the mesoccelia are made unlike so as to indicate
one of the most marked distinctions between the brains of the frog and Menobranchus,
which will be specified later. The left of the two lateral masses has approximately the
form of the hemisphere in the adult Amphibian ; the right has what may be regarded as
the primitive form of the hemisphere in the embryo in all Vertebrates ; compare Balfour,
A, Il, Fig. 257.

* The pairs of dotted lines at the left of the figure indicate the limits of the encephalic
segments, the names of which are written between the ends of the Jines. Of these names,
only one, prosencephalon, is given in full; to the abbreviations of the others, meten., epen.,
etc., the word cephaion is to be added in each case. On the right, the short straight lines
are likewise intersegmental like those in Owen (A, ITI, Fig. 46) ; but the longer lines(A-H),
which pass to the similarly lettered parts of Fig. 112, are persegmental ; that is, they
pass through the several segments instead of between them.

_. Three special sense nerves are represented. The auditorius (WV. au.) arises from the
metencephalon ; the opticus (JV. op.) from the mesencephalon and diencephalon, and the
numerous olfactorii (JV. o/.) from the rhinencephalon.

The only portion of the wall here particularly specified is the terma (lamina terminalis),
forming the cephalic boundary of the aula, the last of the mesal series of cavities.

§ 1073. Fig. 111—Mesal aspect of the right half of an ideal simple brain, exclusive of
the rhinencephalon and the cephalic portion of the prosencephalon.—Of course only the

EXPLANATION OF DIAGRAMS. 411

mesal celie appear in this figure, but the extent of the right proccelia is indicated at the
cephalic end of the right hemisphera.

The porta is represented by the dark spot.

The order of succession of the ccelie and of the segments is seen to be the same as
in Fig. 110.

As in Fig. 110, the shorter transverse lines are intersegmental, and the longer ones
(A-H) persegmental. In most cases the latter correspond closely with those of the
persegmental lines in Fig. 110, but the line H is placed farther caudad, there being, in
the frog and Menobranchus, no considerable difference between the parts of the hemi-
spheres.

The several ccelie are named as in Fig. 110, but in place of the names of the ence-
phalic segments are given the names of their principal parts (§ 1069).

The floor of the mesocelia is formed by the parts called crura cerebri in the higher
Vertebrates, and its sides and roof by the optici. Between the optici and the cerebellum
proper, and perhaps belonging in part to both segments, is a thin and incurved portion of
the roof, the valvula (Vieussenii).

The roof of the diacelia is variously constituted. Its caudal portion consists of ner-
vous tissue, which in the frog, according to Wyman (34, 11), presents commissural
fibers, the ‘postcommissura (Stieda, 22, 17; Ecker, B, Abt. II, 10). The cephalic part
consists mostly of the membranes, but presents the thickening commonly known as cuvnu-
rium or epiphysis or pineal gland (Wyman, 34, 11), which, however, may be only an
indication of the place of attachment of the true conarium (§ 1084). The depressed floor
presents a diverticulum, the infundibulum, leading to the hypophysis or pituitary body.
Ventrad of the cephalic portion of the floor is a transverse band of fibers, the chiasma of
the optic nerves.

The aula forms the last or most cephalic of the mesal series of cavities. Most of its
floor and part of its cephalic boundary is formed by the terma, of which the precommis-
sura ( pres.) is really a thickening and differentiation.

In this figure, instead of the unbroken lateral walls of the ccelie, there are seen the
roofs and floors of the mezal series, irregular in contour and variously constituted in dif-
ferent parts. The proper nervous tissue is atrophied in several places, and the ccelian
parieties consist chiefly of the two membranes, the enveloping pia and the lining en-
dyma (§ 1080).

Each of these membranes is represented by a narrow black line, while in this, as in
Fig. 110, the surface of the nervous tissue is represented by a heavy line.

The metatela, or roof of the metaccelia, consists chiefly of the two membranes. The
transverse ridges upon its ventral aspect in the frog are indicated by the undulations of
the ental line. The roofs of the aula and of the cephalic part of the diaccelia are also mem-
branous (aulatela and diatela). Inthe frog and Menobranchus, although not in the higher
Vertebrates, the diaccelian floor is devoid of nervous tissue along the meson, but no special
name is given thereto.

§ 1074. Fig. 112—Transections of an ideal simple brain at several points.

The points of transection are indicated by the lines connected with Fig. 110 and by
the letters A-H. Of course the continuity of the cceliz cannot appear in these sections,
but they combine the distinctive features of the other two in exhibiting at one view the
peculiarities of the sides and of the roof and floor.

(A) Transection of the Myelon.—More accurate representations are given of this in
Fig. 99, 100, 109, but this indicates the existence of the canalis centralis, which expands
to form the ccelie, and the peculiar form of the deeply fluted column of cinerea, which

412 ANATOMICAL TECHNOLOGY.

is here made black ; the shaded portions represent the lateral, dorsal and ventral columns
of alba.

The abbreviations signify as follows :—Olm. d., Columna dorsalis—‘‘ posterior white ”
column, Clm./., Columna lateralis—‘‘ lateral white” column. (lm. v., Columna ven-
tralis—“‘ anterior white” column. /. dms., Fissura dorsimesalis—“ posterior” fissure.
F. oms., Fissura ventrimesalis—‘‘ anterior” fissure. Orn. d., Cornu dorsale cinerese—
“posterior horn of gray matter.” Crn.v., Cornu ventrale cinereee—“ anterior horn of gray
matter.”

(B) Metencephalon.—The ventrimesal fissure is nearly obliterated, but the sides of
the dorsimesal are widely separated, and the central canal opened into connection with
the space, metaceelia, so formed. The roof of the metaccelia is the metatela, composed
of the pia and endyma, and the mesal ridge is indicated by the undulation of the latter.

(C) Epencephalon.—The floor and sides of the epiccelia are similar to those of the
metaccelia in the frog and Menobranchus, but in Mammals the former is reinforced by the
pons, and the latter presents three sets of fibers, the pedunculi of the cerebellum. This
latter is here represented in its essential character as a bridge over.the epicelia (Ecker, B,
Abt. II, 8), without the mesal furrow which indicates the junction of the optici and
thalami of the two sides.

(D) Mesencephalon.—Aside from its greater width, the chief difference between this
region and the epencephalon is the existence of the distinct dorsimesal furrow, whence
the name corpus bigeminuwm. Inthe higher Vertebrates, the floor of the mesoccelia is
more or less differentiated as the crura cerebri. In Menobranchus the mesoccelia is
large and simple ; in most Mammals it is narrowed by the approximately uniform thick-
ening of all the walls, and may be reduced to a mere passage. In the frog the cavity is
very irregular, and no attempt is here made to indicate its form, excepting on the left of
Fig. 110; hence the difference from Fig. 16 and 17 of Stieda (22).

(E) Diencephalon.—This transection is through the caudal portion of the segment.
The thalami constitute the sides of the diaccelia, and their roof presents the special band
of fibers known as the postcommissura (pces.). At the ventrimeson the proper nervous
floor is absent, but the two membranes are unbroken. The slightly protuberant floor
_ answers to the more distinct tuber cinereum of the higher Vertebrates ; compare Stieda
(22, Fig. 18). In the right of the diaccelia is represented a section of the free part of
the right diaplexus of Menobranchus (§ 1097), which does not exist in the frog.

(F) Diencephalon.—This is through the cephalic portion of the segment. The two
lateral figures represent the caudal ends of the hemisphere, which project caudad consid-
erably beyond their points of attachment. In the diencephalic portion of the figure, the
sides are the thinner cephalic portions of the thalami, and the floor is reinforced by the
chiasma; the rcof is membranous at the sides, but thickened at the meson to form the
conarium or its continuation (§ 1084).

(G) Prosencephalon—Aula and Porte.—The two procelize are seen to communicate
with a mesal cavity, the aula, through the two porte. The floor of the aula is here
formed by the terma, but the roof (aw/atela) consists of only the membranes. Compare
Stieda (22, Fig. 21), where, however, the membranes are omitted, and the caudal border
of the pracommissura is included, so as to separate the dorsal part of the aula proper from
the cephalo-ventral portion.

(H) Prosencephalon—Hemisphere.—This figure may represent the transection of
almost any portion of the prosencephalon or rhinencephalon cephalad of the terma; com- —
pare Stieda (22, Fig. 22). The hemispheres are usually in contact, but are united organ-
ically only in Mammals (by the callosum). Their cavities (proceliw) communicate with

RELATIONS OF THE CQ@LI®. 413

each other only through the porte and aula. In addition to the line representing the pia
in direct contact with the masses, the arachnoidea (arch.) is represented by the line
bridging the interval between them.

§ 1075. Relations of the Ceeliz.—These are most clearly indicated in Fig 110, repre-
senting a horizontal section of the typical brain. The ccelize form two series, caudal and
cephalic. The former are mesal or azygous, the latter are lateral or paired. The arrange-
ment may be roughly compared to a two-tined fork, the handle representing the mesal
series and the prongs the two lateral extensions.

A more accurate analogy is with the apartments of a house. A narrow passage (the
canalis: centralis of the myelon) opens into a wider apartment, or rather a suite of apart-
ments but slightly distinguished from each other. From the farther (cephalic) end (aula) a
passage (porta) upon either side opens into a wing or lateral extension, each containing
two apartments, the second of which is closed at the farther end.

§ 1076. Comparison of the Brain with a House.—Let us imagine that a house con-
sisting of a series of apartments in the order represented in Fig. 110 is completely envel-
oped by a continuous layer of tarred paper, and that its rooms are lined throughout
with wall paper, the ceilings and floors being covered with the same.

Now it is conceivable that (1) the proper wooden wall of any apartment might be so
reduced in thickness at any point as to hardly merit the name; (2) it might be omitted
altogether along a given line, leaving only the two layers of paper ; (8) a fold of the ental
or lining paper might hang within the apartment ; (4) between the two layers of the fold
might be interposed a fold of the ectal or covering paper; (5) instead of a complete fold
of the ectal paper there might be supported in the fold of the ental some looped strings or
fringes connected primarily with the ectal layer.

It is also evident that (1) while the fold of ental paper is really projected into the apart-
ment, (2) the fold of ectal paper, or the strings or fringes of that paper, are covered by the
ental paper, and are therefore not really within the apartment ; (8) any force applied from
within or without will be likely to rupture the wall along the line of interruption of the
proper wooden wall, corresponding with the line of reflection of the ental paper therefrom
to form the fold.

§ 1077. Arachnoidea.—Afier the removal of the cranium and the dura which lines it,
the brain of the frog, cat, man, and presumably of all Vertebrates, is found to be covered
by two membranes. Of these, the ectal is the more delicate, and is known as the arach-
noid. It was formerly described as presenting two layers, a visceral next to the brain and
a parietal lining the dura; according to Quain (A, II, 573), there is insufficient evidence of
the existence of the latter, and it is not represented herein. :

The arachnoid passes from lobe to lobe and from fold to fold across intervening spaces
or fissures, or dips but slightly therein.

§ 1078. Pia.—This is in direct contact with the brain, follows closely the contour of
the lobes and folds, is pigmented in the frog and some other animals, and supports blood
vessels which send branches into the substance of the brain. :

The pia is represented in all parts of Fig. 111 and 112; the arachnoid only in Fig.
112, H.

§ 1079. Hndyma.—As intimated by Todd (A, 634), Duval (2, 164), Wyman (34, 15),
Balfour (A, II, 364), and Quain (A, II, 540), and confirmed by our observations, all parts
of the true cavities of the vertebrate brain are lined by a smooth epithelium called epen-
dyma or endyma, the shorter name being preferable. This is akin to a serous mem-
brane, and secretes a watery liquid which may (as in hydrocephalus) be produced in large
amount,

414 ANATOMICAL TECHNOLOGY.

§ 1030. Tele.—The pia bears to the brain which it covers the relation which the
tarred paper does to the house, while the paper covering the interior walls is represented
in the brain by the endyma.

Where the proper nervous substance of the ccelian parietes is atrophied so that the pia
and the endyma are nearly or quite in contact, the resultant is called a tela.

With the cat, and probably with other animals, the tele sometimes seem to be not
altogether devoid of nervous structure ; indeed, it would seem quite possible that between
a true membranous tela and a thin nervous lamina like the cephalic part of the raivula
there may be at least one intermediate condition.

When the pia is removed, the tele, being connected therewith, are apt to be torn off ;
but the consequent exposure of the cavities is no more proof of the presence of a natural ori-
fice than is the fontanelle of a child, after the removal of the scalp and the dura, evidence
that the cranial cavity is naturally in free communication with the outside of the head.

§ 1081. Plexuses.—Notwithstanding the more or less elaborate accounts in works upon
Descriptive Anatomy, and some recent efforts to elucidate their mode of development,
the precise structure and arrangement of the plexuses is far from well ascertained. Indeed,
it is probable that a plexus may be formed in two or more ways in different species or in
different parts of the same brain.

As we understand the matter, a ccelian plexus is formed in one of two ways :—

(A) Certain vessels of the pia are protruded entad of the proper nervous parietes so as
apparently to enter the ceelie.

(B) Certain parts of the pia containing vessels are carried as folds entad of the parietes
so as apparently to enter the ccelie (Fig. 121).

In either case the endyma along the line of interruption of the proper nervous wall is
reflected upon the intruded pia or vessels and covers them completely ; hence, while the
thinness of the epithelium permits osmosis to occur practically as if the vessels were free,
yet from a morphological point of view they are not free, but are excluded from the cavity
just as the kidney or the intestine is excluded from the abdomen by the visceral layer of
peritoneum (Fig. 78); in fact, the cases are strictly comparable.

§ 1082. The alleged ‘‘ Foramen of Magendie.”—Magendie described (A), under the
name “‘ orifice des cavités encephaliques,” an opening which he believed to exist in the
metatela near the caudal end of the metacelia. Luschka figured it (A, Taf. III, Fig. 1),
but no other representation is known to us, although its existence is generally admitted
(as in Quain, A, II, 513 ; Mihalkovics, A, 59).

Todd, however (A, 641), believes such an orifice to be artificially produced ; the senior
author (14, 548, 555) could not find it in the cat, and its natural presence is emphatically
denied by Duval (7, 33). See, however, Westbrook (2).

§ 1088. Complete Circumscription of the Cavities.—First in 1876
(Wilder, 4; 9, 136), and frequently since, we have made upon the
cat?s brain experiments (by inflation with air and by the injection
of alcohol, water and plaster), which failed to indicate the presence
of any natural communication (as by the rima or “fissure of Bi-
chat” or ‘‘great transverse fissure’’) between the cceliz and the
exterior.

Upon a point of general arrangement like this there is every
presumption in favor of uniformity throughout the vertebrate series ;
hence we may fairly regard the celia (excepting at an early stage

CONARIUM AND HYPOPHYSIS. 415

of development) as completely circumscribed, usually by mervats
tissue, always by membranes.

This idea is more or less distinctly enunciated, upon various grounds and respecting
various animals, by the following writers: Foster and Langley (A, 224); Balfour (A, 364);
Todd (A, 634); Mihalkovies (A, 115); Duval (2, 38); Quain (A, II, 546); Hadlich (2);
Lowe (A): Mivart (B, 266); and probably others.

§ 1084. The Conarial Tube.—The above statement respecting the complete circumscrip-
tion of the ccelize excluded the earlier embryonic stages on account of the views of Gitte
(A). According to this observer, as briefly stated by Balfour (A, 356), the conarium is the
remnant of the canal by which, as is commonly believed for Vertebrates in general, the cavity
of the embryo myelencephalon communicates with the ectal surface of the head. Accord-
ing to Stieda, as stated by Balfour (A, 357), a part of the conarial tract persists upon the
outside of the cranium with some Amphibia, and the corresponding orifice of the cranium
is identified as the parietal foramen of some fossil Reptiles by Owen (Z). The entire
“ conario-hypophysial tract,” as it is termed by Owen, has great morphological interest,
but for our present purposes it seems best to omit any detailed account of the various
views, and to refer only to the generally accepted opinion as to the primitive origin of the
hypophysis from the alimentary canal. (Owen, 7; Balfour, A, II, 358 ; Quain, A, II, 735 ;
Foster and Balfour, A, 91; Parker and Bettany, A, 10; Mihalkoviecs, A, 83).

STUDY OF THE AMPHIBIAN BRAIN.

§ 1085. Obtaining the Animals.—Directions for procuring frogs
and Menobranchi and caring for them will be given in the Appen-
dix. Large examples are to be preferred for the study of the brain,
and they should be obtained alive or freshly killed.

§ 1086. Killing. —Place the animal in a jar or covered vessel of
water, and pour off any water in excess of what is needed to simply
submerge it. |

Pour in a little chloroform, not more than 5 cc. ; it will sink to
the bottom as oily looking drops. The movements of the animal
will usually diffuse it more or less, and the vessel may be shaken if
necessary. Death will ensue in 10-30 minutes.

If ether is used, it will float upon the top of the water, the ves-
sel must be shaken, a longer time is required, and the animal is
more likely to revive unless the subsequent operations are done
without delay.

If no anesthetic is at hand, decapitation may be performed with
the bone scissors by cutting caudad from each angle of the mouth
to the caudal margin of the brachium in the frog and the caudal
gill in Menobranchus, and then cutting transversely so as to sepa-
rate the cranium and maxilla, with the first two or three vertebra,
from the mandible and the rest of the body. This should be first

416 ANATOMICAL TECHNOLOGY.

practiced upon dead animals, and should be done very rapidly
“and by only three strokes of the scissors.

If only the cephalic portion of the brain is wanted for some special purpose, the animal

may be pithed as directed in the Appendix ; the brain should be exposed at once so as to
prevent the clotting of blood about it.
_ Ifa toad is used, it should be put into a small jar or under an ‘‘ open-top ” bell jar, and
a sponge saturated with chloroform suspended by a string near the top. In handling the
toad, it is well to protect the fingers with gloves or a cloth, and care should be taken not
to get the acrid dermal secretion into the eyes.

§ 1087. Injection.—For the special study of the telw and plexuses, the vessels should
be injected. This is most conveniently done with cold flowing blue material from the
bulbus arteriosus ; see Appendix.

§ 1088. Exposure of the Frog’s Brain—Jnstruments and Ma-
terials.—Small tray with waste paper; bit of cloth ; arthrotome;
coarse forceps ; pointed nippers; bone scissors, not too dull; wide
mouthed vial containing at least 25 cc. of 62-67 per cent. alcohol ;
(to 10 cc. of water add 15 or 20 cc. of 95 per cent. alcohol; see
§ 273); refer to some figure of the brain (§ 1098).

Fix the head by introducing the tip of the left index into the
mouth and applying the pollex upon the snout. With the scissors
or arthrotome, divide the skin between the cephalic angles of the
eyes.

With the forceps, grasp the caudal cut edge of skin, and with
the scissors, cut the skin along a line extending approximately cau-
dad and just mesad of the eye and the ear (membrana tympant) on
each side as far as a point opposite the caudal border of the bra-
chium. Connect the caudal ends of the two incisions so as to remove
the flap.

Grasp the left dorsal eyelid, and with the scissors cut mesad of
the eyeball, gradually everting it and cutting the muscles until the
round, white JV. opticus is divided. Then cut more boldly and
remove the entire ball.

rom the orbit push a scissors blade through the mucosa into
the mouth, and cut cephalad through the snout. Then cut caudad
in the same way, along the same line or a little farther laterad, as
far as the skin was removed. Finally, cut from the angle of the
mouth so as to remove the bony projection containing the left tym-
panum or middle ear.

With the nippers, tear up the muscles dorsad and laterad of the
caudal part of the cranium and the first two or three vertebre.

Cautiously nip off the projecting border of the cranium at the

EXPOSURE OF THE BRAIN OF MENOBRANCAHUS. 417

orbit until the left Zobws olfactorius or the hemisphere is exposed.
Continue to remove that side of the cranium and the roof in very
small pieces and with great care. The widest part of the brain (me-
sencephalon, optic) lies opposite where the tympanum was removed,
and is liable to injury unless the adjoining cartilaginous capsule of
the internal ear is removed very cautiously.

Caudad of the mesencephalon the brain is narrower and merges
into the myelon, which must be exposed by the removal of the
neural arches ; it will be necessary to cut away part of a thin car-
tilaginous plate upon the shoulder, the swprascapula (§ 383).

Pass a scissors blade through the pharynx to the dextral angle
of the mouth and cut obliquely, so as to separate the cranium and

two or three vertebree from the rest of the body.

§ 1089. Haposure of the Brain of Menobranchus.—Instrumenis
and materials (§ 1088). With the arthrotome, cut the skin upon a
transverse line just.cephalad of the eyes. With the scissors, cut
caudad along a line just mesad of the eye on each side to a point
opposite the cauda! gill. Raise and remove the flap so outlined,
noting that the skin adheres more closely than in the frog, and that
between it and the cranium there are considerable muscles.

With the arthrotome scrape the muscles from the bone, begin-
ning at the cephalic end of the exposed area. Alternately ventri-
duct and dorsiduct the head so as to indicate the position of the
occipito-atlantal arthron. With the arthrotome, carefully pick up
the membrane between the atlantal neural arch and the cranium so
as to expose the metencephalon (medulla).

With the nippers remove the neural arches of the first two or
three vertebree, taking care not to weund the myelon. Then remove
the occiput in like manner, inserting the nipper blade but a very little
way. The larger part of the cranial roof is very thin and may often
be lifted in slivers upon the point of the arthrotome, but with large
individuals the nippers may be needed. Special pains should be
taken not to disturb the metatela, a pigmented and vascular curtain
just cephalad of the occiput, which sometimes adheres to the skull
or is caught by the point of the instrument.

When the dorsal aspect of the brain is exposed, with the scissors
cut away the left side of the head along the line of incision of the
skin, and then cut across the vertebral column and other parts
obliquely from the caudal end of the incision to the dextral angle
of the mouth.

27

418 ANATOMICAL TECHNOLOGY.
eo

§ 1090. Preservation.—Place the preparation in the 62-67 per
cent. alcohol for at least two days. Then transfer it to 95 per cent.
alcohol, where it should remain if a permanent preparation is to be
made. For most purposes it is best to leave the brain supported by
part of the cranium. If the base of the brain is to be specially
studied, the base of the skull must be more completely removed ;
it is thin, but so closely in contact with the brain that much care is
required.

§ 1091. Labeling.—To the vial containing the brain should be affixed a tag (§ 162)
bearing the name of the genus and, if possible, of the species, and stating the sex and
locality of the animal, the date of the preparation, and the name of the preparator.

The genus will be either Menobranchus (sometimes called Necturus), Rana (frog), or
Bufo (toad). Probably there is only a single species of Menobranchus, /ateralis, but the
doubt upon this point renders the noting of the locality essential. Of the toad there is
but one species, lentiginosus (Americana), common in the Northern United States. There
are several species of frogs, the largest being the pipiens of some authors, but the Catesbi-
ana according to Jordan’s “ Manual” (A, 188).

If any generalizations are to be based upon the specific characters of the brain, and
there is doubt respecting the determinagjon, the entire body should be kept for reference,
and labeled like the brain.

With the female Menobranchus the vent is a simple longitudinal slit, but with the
male it presents numerous papille, especially in the spring. If in doubt, open the abdo-
men and note that the testes are elongated solid organs, while the ovaries are thin walled

sacs, one on each side, with ova of two or more sizes, the largest in the spring being yel-"

low and nearly as large as small peas. With frogs and toads the testes are small oval
bodies, while the ovaries are voluminous lamine with dark colored eggs.

§ 1092. General Inspection of the Amphibian Brain.—In what
follows, including the dissection of the brain, no attempt is made to
give exhaustive descriptions or directions.

Notwithstanding the numerous figures and descriptions of the frog’s brain, none of its
parts are known as they should be, and that of Menobranchus can hardly be said to be
known at all excepting in the most general way. But our ignorance of many details of
their anatomy need not prevent our use of them for the sake of illustrating certain features
of brain construction which are comparatively obvious with them, but obscured with the
brains of the higher Vertebrates.

Since the frog is the more common and likely to be used more frequently, the directions
apply primarily to it, while the peculiarities of Menobranchus are separately mentioned.

§ 1093. Frogs’ brains are figured and more or less fully described in the following
works and papers. So far as we can judge, the figures are original in only the first seven :
Wyman, 34; Ecker, B; Gegenbaur (Lankester), A, Fig. 283; Leuret et Gratiolet, A,
Pi. IL; Laurencet, A, Pl. IL; Spurzheim, A, Pl. III; Bourgery and Jacob, A, VIII, Pl. 22,
Fig. 4; Mivart, A, Fig. 74; Huxley, A, Fig. 59; Cyon, A, Taf. 24; McAlpine, A, Pl. 21;
Burdon-Sanderson, A, Pl. 109 ; Packard, A, Fig. 373.

Figures of the brain of Menobranchus or other urodelous Amphibia are given in the
following ; the accompanying descriptions are usually very meager: Mayer, A ; Laurencet,

INSPECTION OF THE AMPHIBIAN BRAIN. 419

A, Pl. II; Wyman, 34, Pl. I; Duges, 4, Pl. 10; Bourgery and Jacob, A, VIII, Pl. 22,
Fig. 7; Owen (Linnean Transactions, XVIII, Pl. 27).

§ 1094. Instruments and Materials.—Tripod magnifier; fine
forceps ; beaded bristles ; small dish of 62-67 per cent. alcohol or 15
per.cent. glycerin in which the brain may be dipped, or a vial of the
same with a quill duster for applying the liquid.

Keep the brain wet with the alcohol or glycerin.

Remove the white masses of calcareous crystals at the side of
the caudal region.

Compare the several regions with Fig. 110, or with figures in
other works (§ 1093).

§ 1095. Note the lateral expansion of the myelon to form the
metencephalon (medulla), abrupt in the frog, very gradual in Men-
obranchus.

Note the pigmented metatela which forms the dorsal surface of
the metencephalon.

If the metatela is in place, its cephalic border more or less com-
pletely covers the cerebellum. Grasp its sinistro-cephalic angle
with the forceps and invert it gently until it lies dextrad of the
metencephalon. Note its thickness as compared with the myelonal
pia, and the symmetrical corrugation of the ental surface. The
cavity thus exposed is the metaccelia (ventriculus quartus).

In Menobranchus the metaceelia is much elongated, and the caudal part of the meta-
tela is very thin.

Cautiously remove the arachnoid from the dorsal aspect of the
entire brain, excepting just between the divergent caudal ends of
the hemispheres ; it is little if at all pigmented, and bridges the
interhemispheral fissure as shown in Fig. 112, H.

The widest region is the mesencephalon (optici), the pia of
which is thickly pigmented. Note the marked mesal furrow be-
tween the two lateral convexities, and that the longer axes of the
latter diverge cephalad.

In Menobranchus the mesencephalon is but little wider than the adjoining segments,
the mesal furrow is very shallow, and the lateral masses hardly merit the name of lobes.

Between the optici and the metaccelia is a narrow transverse
band, unpigmented and with its caudal margin dorsiverted, and
separated from the optici by a somewhat deep furrow. This is the
cerebellum, the dorsal part of the epencephalon.

420 ANATOMICAL TECHNOLOGY.

In Menobranchus the cerebellum is very narrow, its caudal margin is not dorsiverted,
there is no furrow between it and the optici, and it is distinguishable from them mainly
by the absence of pigment.

The diencephalon is decidedly narrower than the parts cepha-
lad and caudad of it and is partly covered by their projections, and
the mesal furrow is less deep than between the optici. In Meno-
branchus its caudal limit is not easy to assign.

Upon the cephalic part of the diencephalon rests the conarium
(or its continuation, § 1084); this body is not round, as almost uni-
versally shown, but oval, and anteverted so as to rest also upon the
roof of the aula. :

If the cephalic (really dorsal) end of the conarium is cautiously
elevated, there will be exposed a delicate membrane, the aulatela,
or roof of the aula.

The hemispheres, the largest portion of the prosencephaton, con-
stitute the widest part of the brain with Menobranchus, and the
longest in both it and the frog. In the latter they are compressed,
in the former depressed. As already indicated, their caudal ends
flare laterad so as to partly embrace the diencephalon and nearly
reach the optici in the frog. Their mesal surfaces are in contact,
but may be separated in the cephalic part by blowing between
them or by a beaded bristle.

At the cephalic end of each hemisphere is attached the corre-
sponding Lobus olfactorius, the lateral half of the rhinencephalon.
The Nervi olfactorii may be traced thence to the nasal capsules.
The lobes are separate in Menobranchus as in most Vertebrates,
but in the frog and other Anura they are united by connective tis-
sue constituting a pseudo-commissura.

§ 1096. Dissection of the Amphibian Brain.—The arachnoidea
and the metatela have been removed as directed in § 1095.

Instruments and Material.—Tripod magnifier; fine forceps ;
beaded bristles ; very sharp scalpel, preferably small; fine scissors ;
syringotome or tracer ; flexible blowpipe (§ 138) ; alcohol or glycerin
as directed in § 1094.

Note at the bottom of the metacelia a@ mesal furrow, which is
continuous caudad with the canalis centralis of the myelon.

With the flexible blowpipe, blow cephalad under the cerebel-
lum, and note that all the parts of the brain are inflated, showing
the existence of a continwous series of cavities, as represented in
Fig. 110.

DISSECTION OF THE AMPHIBIAN BRAIN. 421

With the scalpel previously dipped in alcohol, or with the fine
scissors, cut off obliquely the latero-caudal angle of the left hemi-
sphere. This exposes the corresponding proccelia, and blowing
into it inflates all the other parts. With the scissors, remove the
entire latero-dorsal wall of the hemisphere, noting its extension,
rhinoccelia, into the base of the Lobws olfactorius.

Blow gently upon the mesal wall of the hemisphere at about its
middle, and note the presence of an orifice through which air passes
into the other ccelize ; this is the left porta or ‘‘ foramen of Monro.”
Note the continuity of the hemisphere wall at all other points.

Wyman mentions (54, 15), but does not figure, another opening from the procelia
dorsad of the thalamus; this, as he suggests, would probably correspond with the rima or
‘* fissure of Bichat.” It could not appear until after the removal of the pia, and we have
not satisfied ourselves of its existence.

Pass the beaded bristle through the porta toward the opposite —
hemisphere, and note that it enters the other proccelia, as indicated
by the protrusion of its wall at some point.

Just cephalad of the porta is an elliptical raised surface which
is thought by some (Wyman, 34, 15) to represent the striatum of
the higher Vertebrates, but there is doubt upon this point.

In Menobranchus the porta is partly filled by a pleaws which extends cephalad in the
procelia ; this is the proplexus, which may be snipped off with the scissors, but never
pulled upon. The porta is much longer than in the frog, but there is no thickening of ~
the mesal wall of the hemisphere like the supposed striatum of the frog.

With the scalpel, remove the lateral prominence of the left opéi-
cus, and note that a somewhat expanded lateral portion of the
mesoccelia communicates by a constricted orifice with the mesal
portion and so with the corresponding expansion in the right opti-
cus. Then remove the dorsal wall of the entire mesoccelia with the
scalpel and scissors, and note the marked folding, the valvula, by
which the cerebellum is continuous therewith. Pass a bristle ven-
trad of the cerebellum into the mesoccelia, and then sinistro-cepha-
lad through the diaccelia so as to emerge in the leit proceelia.

Slice off the caudal part of the diaccelian roof, including the part
known as postcommissura. Note that the walls (thalami) are quite
thick and nearly in contact, but that the interval is a nearly simple
vertical fissure and not a wide and partly divided cavity like the
mesoceelia. Pass a bristle caudo-ventrad so as to enter the hy-

pophysis.

422 ANATOMICAL TECHNOLOGY.

By placing the bead of the bristle, or the tip of the tracer or
syringotome, in the cephalic part of the diaccelia, note that the roof,
diatela, is partly membranous and partly formed by the thickening
known as the conarium (§ 1084).

Then slice away the thalami to a still lower level so as to expose
the diaccelian floor. Note that itis depressed, and bounded caudad
and cephalad by fransverse ridges ; also that there are no plexuses
therein. :

Slice off both hemispheres to the level of the conarium. Then
remove another slice, including the conarium and the aulatela upon
which it rests. This will expose a wedge-shaped cavity, the aula,
which is bounded as follows: caudad, by the ridge mentioned
above as the cephalic boundary of the diaceelia ; laterad, by the
porte whose length nearly coincides with its own ; cephalad, by the
terma, a lamina of nervous tissue uniting the mesal walls of the
hemispheres at the cephalic end of the porte; (the terma is more
easily seen if the left Z. ol. and cephalic end of the hemisphere
are gently pushed away from the right) ; dorsad, by the azwlatela,
the atrophied continuation of the terma.

If the mesal wall of the left hemisphere be removed, the extent
and form of the right porta may be seen.

§ 1097. With Menobranchus the conditions are so different as
' to require special directions :—

Introduce a scissors blade just caudad of the cerebellum on
either side, and cut cephalad to the caudal end of the hemisphere ;
do the same on the other side, and turn the flap so formed cephalad
upon the hemispheres. This exposes the epi-, meso- and diaccelia.
Note that the lateral walls are thicker than the roof, and that the
ental surface of the roof presents a slight transverse ridge which
indicates the division between the diencephalon and the mesen-
cephalon. ~

The floor of the mesoccelia is nearly level, and its cephalic mar-
gin overhangs the passage—the canal of the infundibulum—leading
to the hypophysis. .

In the diaccelia lie side by side a pair of string-like plexuses—the
diaplexuses—which are attached to the aulatela or diatela and ex-
tend the whole length of the cavity. They should be drawn to the
sides or cut off, but not pulled upon atall. The floor of the diaceelia
is then seen to be irregular, sloping from each side to a mesal furrow.

REMOVAL OF THE BRAIN. 423

The cephalic end of the diaccelia is decidedly narrowed, and the
walls are thin.

§ 1098. Remove the dasis cranii so as to expose the basis en-
cephali as far as the aula. Observe the sub-cordate hypophysis
underlying the mesencephalon, but attached by its base to the
slight intumescence—the tuber cinereum—forming the floor of the
diencephalon.

In case more than one brain is examined, the second should be transected with a
very sharp scalpel, and drawings made to show the form of the cclie at different
points. A third brain may be divided upon the meson, and a fourth opened from the
ventral side. With all of these the metatela should be left in place. Still others may be
prepared to show special points. When many brains are available, each should be devoted
to a given section or dissection, all other parts being untouched, so that the special fea-
tures may be more easily recognized.

REMOVAL OF THE BRAIN OF THE CAT.

§ 1099. The method first described is to be preferred when the
brain is wanted entire, and especially when the length of the nerve
roots is an object; see Wilder, 77.

Instruments and Materials—Medium scalpel , Charriére scalpel ; arthrotome ; tracer ;
curved scissors ; bone scissors ; forceps; nippers, medium or large and small; large tray
for the cat ; small tray, or a folded cloth, for the head; block ; small towel, or piece of
muslin, for aiding the grasp of the head; waste paper; basin and towel; dish of 7 per
cent. brine, about 6 cm. deep and 20 wide. containing some well soaked cotton ; bowl of
normal salt solution (15 grams of salt to 2000 cc. of water), sufficient to cover the head
after its separation from the body) ; bowl for catching the blood ; glass box (§ 307); wide
mouthed jar or covered dish of 62-67 per cent. alcohol, with some well soaked cotton at the
bottom ; a cat's skull ; figure of the basis eranti (Fig. 57); figure of the basis encephali
(Fig. 115, Pl. II, Fig. 3); Table of the cranial foramina (§ 562).

§ 1100. Killing the Cat.—The cat may be drowned, but is more conveniently anes-
thetized (§ 192). Kill the fleas as directed in $193. As soon as respiration ceases, sus-
pend it by the head over a pail or the sink, and expose and divide the femoral artery and
vein (Fig. 39) centrad of the valves in the vein (§ 362); even if little blood escapes, the
amount in the brain will be reduced. If it be desired to ascertain the weight of the entire
animal, the blood should be caught in the bow] and weighed.

For injection with alcohol, see $§ 284, 285.

For injection of the plexuses, see § 1126.

If the more delicate internal parts or the microscopic structure are to be studied, the
remaining operations for the procurement of the brain should be performed within 24
hours. But if the specimen is desired only for the fissures or the coarser anatomy, re-
moval may be deferred for a week, provided the head be kept in a cool place. It should
not, however, be allowed to freeze.

§ 1101. Decapitation.—From the dextral angle of the mouth di-
vide the skin along a line extending nearly caudad for 6-S cm. If

424 ANATOMICAL TECHNOLOGY.

the skin is to be mounted, this should be the only incision, and the
skin must be dissected from the mandible as well as from the rest
of the head. But if, as is more often the case, the skin is not to be
preserved, while the vessels and nerves of the neck are to be exam-
ined, make a corresponding incision from the angle of the mouth
upon the opposite side.

In all subsequent operations, unless otherwise stated, both sides
are to be treated alike.

Dissect the skin from the maxilla as far as the ventral margin
of the orbit and cut the nasal cartilages. Dissect the skin from the
nasal and frontal regions, including the dorsal and ventral lids but
- leaving the third lid, Membrana nictitans, attached to the ball.
Remove the skin from the rest of the head, dividing the meatus
auditorius close to the head. The parotid gland (Fig. 87) will be
removed with the ear, but the submaxillary, of a darker color, will
remain with the head. Reflect the skin from the cervical muscles
for about 2 cm. caudad of the crista lambdoidalis.

With the arthrotome, dissect the origin of the 1. massetericus
from the zygoma, noting that its cephalic and caudal borders are
strengthened by tendinous bands which must be cut (§ 596, 19).
Push a nipper blade between the eyeball and the cephalic root of
the zygoma, and nip the latter as close as possible to the maxilla.
Then nip the caudal root at the angle between the transverse and
longitudinal parts of the zygoma, just laterad of the Hossa glenoi-
dalis ; remove the zygoma with the bone scissors.

Grasp the lateral aspect of the eyeball with the forceps, and
‘rotate it mesad so as to expose its attachments, by the muscles and
JV. opticus, to the bottom of the orbit; cut the attachments with
scissors, leaving the Jb. nictitans connected with the ball. If the
eyes are to be studied or preserved, mark them right and left by
numbers or tags; the proper position is always indicated by the
Mb. nictitans ; see Chap. XI.

Slightly ventriduct the mandible and move it from side to side
so as to indicate the position of the Arthron temporo-mandibulare.
Usually the capsule has been opened already in nipping the caudal
root of the zygoma. If not, it is to be cut while on the stretch by
inserting the arthrotome, and cutting until separation is complete
on that side.

Dissect the MZ. temporalis from its cranial origin, and then
from its insertion upon the Processus coronoideus of the mandible.

EXPOSURE OF THE BRAIN. 425

Bring the mandible to a right angle with the rest of the head, and
divide the soft parts at the angles of the mouth if any remain. In
doing this, insert the arthrotome sidewise so that it may pass
between the Pre. coronoideus and the projection left after the
removal of the cephalic root of the zygoma.

Feel for the caudal border of the hard palate and for the tips of
the Ossa pterygoidea (Fig. 57); at a point midway between push
a scissors blade entad of the soft palate, and divide it; then divide
the mucosa forming the dorsal wall of the postnares, and dissect it
up as far as the atlas.

The mandible is now attached to the rest of the head by some
muscular fasciculi and by the slender piers of the hyoid arch (Fig.
30, § 224). These last join the skull at the lateral side of the bull,
where they are to be divided with the arthrotome ; if it be desired
to examine the mode of their attachment, they may be cut with the
bone scissors at a little distance from the attachment.

Ventriduct the tip of the mandible still farther, and dissect off
the muscles, vectus anticus capitis (§ 628), that are inserted between
the bulle.; near the caudal ends of the mesal borders ef the buile
emerge several nerves, which should be divided with the scissors or
a sharp scalpel at about 1 cm. from the skull. By continuing the
removal of the muscles across the Arth. atlodido-occipitale this is
exposed. Put the membranes upon the stretch, and divide them
with a Charriére scalpel along the cephalic border of the atlas.
This exposes the myezon, which is to be divided in the same way.
The remaining ligaments and the cervical muscles may be cut with
the arthrotome, and the skull proper is then separated from the
rest of the body. Place the skull in the normal salt solution, and
wash the hands and the instruments which have been used.

§ 1102. Haxposure of the Brain.—In the later stages of the ope-
ration there is considerable risk of injuring the brain by the unin-
tentional pressure of the nippers.

In whatever way the bone is grasped, when force is applied, the tendency is to approxi-
mate the cutting’ edges as nearly as possible, and thus to bring their planes into right
angles with the surface of the bone. This of course crowds the convexity of the ental
blade against the brain, and may crush it seriously. It may occur either from the turn-
ing of the nippers in the hand, or more frequently from the escape of the skull from the
grasp of the other hand. The accidents may usually be avoided by keeping the danger in
mind, by having the right hand dry, and aiding the grasp of the more or less slippery
skull by a small towel or bit of coarse muslin; this last is also desirable Core some
stages of the operation as a protection of the hand itself from abrasion.

426 ANATOMICAL TECHNOLOGY.

In using the nippers, another precaution is to be observed. If the bit of bone to be
removed is attached only to bone, it may be either cut or broken or twisted off; but if it
adheres to the dura or other soft parts, only cutting should be employed ; it is safer to
use the bone scissors after nipping the bone.

When any bit of the skull is broxen off, lift it very carefully, and examine its ental
aspect for nerve attachments.

During the exposure of the brain, the head should be frequently dipped into the z. s. s.
If obliged to suspend the operation for more than an hour, wrap the head in a cloth wet
with the n. 8. s., and set in a cool place.

Trim off the soft parts, including the meatus auditorius. Nip
off the caudal root of the zygoma, including the #’s. mandibularis.
Insert a nipper blade into the meatus auditorius, and remove the
bulla in fragments. With the scissors, cut away the membranes
attached to the margin of the im. magnum.

Nip off the occipital condyles, with the intervening area of the -

basioccipital for 2-3 mm. from the foramen. Insert a nipper blade
between the dura and the bone 5-6 mm. from the meson and in line
with the mesal border of the cephalic part of the bulla, and nip out
the basioccipital as far as the middle of the length of the bulla.

At or near the angle left after the removal of the condyle and
the basioccipital, the VV. hypoglossus enters the 7m. condylare, and
passes cephalad to emerge on the ventral aspect of the skull by the
Fin. jugulare. If the series of roots do not appear, carefully re-
move a little more bone until they do. If the nerve roots are to be
specially studied, endeavor to nip off the bone surrounding the
Fm. condylare, so as to save the trunk. On emerging upon the
ventral aspect of the skull, the WV. hypoglossus will be found to lie
very near the 4m. jugulare, and to be more or less intimately
attached to the WIV. glossopharyngeus, vagus and accessorius,
which penetrate the bone by that foramen. In attempting to sepa-
rate the WV. hyp., great care must be used to avoid any traction upon
the roots, which readily pull out of the medulla.

Of the other three nerves, the accessorius is the most caudal,
and the most readily distinguished, but at this stage it is as well to
leave them together, simply endeavoring to remove the bone sur-
rounding the foramen, and to save the trunks pretty long, at least
upon one side. Upon the other, it will save time to cut the roots
just entad of the skull, and the same may be done on one side with
the remaining nerves, or with all upon both sides in case the brain
is not to be employed for the study of the ectal nerve origins.

The dorsal wali of the bulla is hard, but readily crumbles be-

‘EXPOSURE OF THE BRAIN. 427

tween the nippers. It may be removed in small pieces, so as to
save the VV. facialis and auditorius which enter the Meatus
auditorius internus, and the little Lobulus appendicularis of the
cerebellum which is lodged in a slight fossa (/s. ap.) just dorsad
of the meatus (Fig. 59, JZ. a. 7.).

Since no nerves are transmitted by the mesal region of the basis
cranii, it may be removed with comparative freedom as far cephalad
as the sel/a (Fig. 59), where some care is needed to avoid injuring
the hypophysis (Fig. 88, Hy.).

The skull may now be held more securely by the facial region,
especially if a towel is employed. In removing the bone at each
side of the meson, and just cephalad of the bulle, great care is
required to disengage the nerves which emerge by the #m./'m. ovale,
rotundum and lacerum anterius. These nerves, the V1. oculomo-
torius, trochlearis and abducens, with the ophthalmic, superior
maxillary and inferior maxillary divisions of the IV. trigeminus,
penetrate the bone more or less obliquely, and are closely sur-
rounded by dense connective tissue.

The entire maxilla is now to be removed by first nipping the
interorbital region just cephalad of the fronto-maxillary suture, and
then, with the bone scissors, cutting toward this point from just
caudad of the cephalic root of the zygoma. The scissors should be
kept as far cephalad as possible, so that the Lobi olfactorii may
not be injured. This plan serves equally well for some dogs, but
with the larger breeds, which have prominent olfactory lobes, the
interorbital region should be nipped at about the middle of the
length of the nasal bones.

§ 1103. Remove the mesal wall of the orbit and the turbinated
bones, using care not to crush the very soft Lodi olfactorii. The
olfactory nerves should be divided, a few at a time, with the scissors
or the tip of the scalpel, and all pulling and twisting of the parts
must be avoided.

The large and white Wervi optict will have been seen in the
orbit, and should be divided near the bone. In removing the plate
(Fig. 60) upon which the chiasma rests, use care not to pull upon
it, lest the ¢erma or other delicate parts should be torn.

During the remaining steps of the operation, the head must be
held by the parietal regions, and with great care, so as to avoid
pressure of the tips of the fingers upon the brain. The bone also
must now be cut by the nippers rather than twisted or broken.

428 ANATOMICAL TECHNOLOGY.

Nip off the supraoccipitale, including the dura, as far as the
Crista lambdoidalis. Then nip off the crista itself in its whole
extent until the attached border of the bony tentorium is seen to be
free from the parietalia. ‘Then divide the ventral ends of the ten-
torium as follows :—

Hold the head with the ventral side down, support the caudal
divisions of the brain with a disengaged finger, and with tracer and
scissors separate the cephalic surface of the cerebellum from the
tentorium.

Introduce a nipper blade between it and the hemisphere on
either side, in such a way that the greater convexity is toward the
hemisphere rather than the cerebellum ; the cut is to be made at
the level of the Sutura squamosa; the width of the tentorium at
this point is about 8 mm., and the nipper blade should not be intro-
duced to a greater depth than that, for fear of injuring the optici.
Tn closing the blades, the head should be held very firmly so that
no rotation may occur. The detached tentorium may be extracted
by the forceps, or by the nippers used as forceps, any adhesions
being carefully separated with the tracer or scissors.

Hold the head over the 7 per cent. brine, with the ventral side
down, and nip out, piecemeal, a triangular piece of the calva.
The mesal adhesions of the dura may be divided with the scissors,
but elsewhere the dura is to be left upon the hemispheres. As the
hemispheres begin to fall, hold the head so that they are supported
by the brine, and then snip all remaining adhesions until the entire
brain is free and floats in the liquid.

§ 1104. Removal of the Dura.—Saturate some cotton with the
brine, and place it under the brain, so that about one third of the
organ projects above the surface. Avoid handling and lifting the
brain ; move it by shifting the cotton or by grasping the dorsal por-
tions of the dura. Remove the dorsal and lateral parts of the dura
by grasping the free borders left by cutting along the dorsimeson,
and cutting out piece by piece with the scissors. Then grasp the
Falz just dorso-caudad of the Lodi ol., at the straight transverse
fissure—/’. cruciata ; introduce the scissors about 5 mm., and cut
the falz. Gently draw the cephalic portion cephalo-ventrad be-
tween the Lodi o/., and remove it. Draw the caudal portion cau-
dad, and carefully cut all its attachments.

Turn the brain upon its dorsal surface, and remove the ventral
portions of the dura with great care and in small pieces. Especial]

REMOVAL OF THE PIA. 429

pains are needed in connection with the hypophysis and the nerves,
and all pulling must be avoided. On one side, at least, it is well to
leave the dura still attached to the nerves and the great Gasserian
ganglion upon the JV. trigeminus (Fig. 115; Plate II, Fig. 3, Gn. G.),
to be more completely removed at the time of the removal of the pia.

§ 1105. Transfer to the Alcohol.—Place a large spoon or watch

glass at the side of the brain, and pull the cotton which supports it,
so as to roll it into the glass, resting upon its dorsum. Let the
brain slide from the glass into the alcohol so as to rest upon the
cotton therein, still with the ventral side up.

Set the bowl with the alcohol in a cool place, and change the
position of the brain at intervals of 5-10 hours during the first three
days, by pulling the cotton in various directions. At the end of
about three days, transfer the brain to 95 per cent. alcohol, where it
may remain indefinitely. For a few days, however, it should rest
upon cotton, and its position be occasionally changed. For the
management of alcohol employed in the preservation of brains, see
§$ 286, 296.

§ 1106. Weighing the Brain.—If this is to be done, handling of
the brain may be avoided as follows: Place the bowl of alcohol
into which the brain is to be put upon the scales, and pour in alco-
hol of the same strength until it balances an even number of grams,
é. g-, 400, 410 or 420. While the brain is in the spoon or watch
glass, pour over it some of the same alcohol, and then let the latter
drain off as much as possible by tilting the glass and supporting
the brain with the fingers or a bit of cotton. Then transfer to the
bowl of alcohol as above directed, and the increase in weight will
represent, with approximate accuracy, the weight of the brain.

§ 1107. Removal of the Pia.—This is most easily accomplished
at the time of the removal of the brain to the stronger aleohol. At
any subsequent period the pia is apt to be more firmly adherent.
If the brain has been allowed to dry at all during its removal from
the skull, the pia comes off with great difficulty, or parts of the
cortex are torn off with it.

§ 1108. Instruments and Materials.—Coarse and fine forceps ;
medium or fine scissors; wetting bottle of 15 per cent. glycerin ;
cotton thoroughly wet with water, and so molded as to form a sort
of shallow cup in which the brain may be grasped, or on which it
may rest without danger of rolling off.

Place the brain upon the cotton, and wet it with the glycerin.

430 ANATOMICAL TECHNOLOGY.

Then let it rest upon its ventral side, and grasp it in the cotton,
firmly yet gently. Grasp with the forceps the fold of pia which
occupies any one of the fissures, especially at the point of forking
or junction with another fissure, and pull along the line of the
fissure. Usually the fold of pia will come out easily, and with it
will be removed some of the pia covering the free surface of the gyri
between it and the adjoining fissures.

Proceed thus until the pia has been removed from the dorsal
and lateral aspects of the hemispheres. . Avoid pulling across the
line of the fissures. The larger forceps are easier to work with, and
less apt to puncture the brain; but the fine forceps are sometimes
required for the removal of the pia from the bottom of a deep fissure.
The caudal surface of the hemispheres may be reached by slightly
ventriducting the cerebellum. The mesal pia can be removed only
at the margins of the hemispheres.

On one side, preferably that on which the JV. opticus was cut
shorter, raise the mass of nerves formed by the divisions of the VJ.
trigeminus and abducens by its lateral border, and cut with the
scissors the JV. oculomotorius which holds the mesal border close to
the brain. This will permit the mass to be turned caudad so as to
expose the course of the slender JV. trochlearis which emerges from
between the hemispheres and the cerebellum. It also permits the
removal of the pia from the region just laterad of the hypophysis.
Grasp the pia on the ventrimeson just caudad of the Zobi ol., and
pull caudad so as to remove it as far as the chiasma, taking care
not to tear the delicate ferma just dorsad of the chiasma. Then
remove the pia from the olfactory tracts.

In removing the pia from the metencephalon, the position of the
nerve roots should be constantly kept in mind, the tripod (Fig. 26)
should be frequently used, and traction should beavoided. Itis very
difficult to preserve the delicate funiculi of the WV. hypoglossus, for
their connection with the pia seems to be closer than with the brain.
Sometimes it may be necessary to submerge the brain in water or alco-
hol, so as to float the roots out and render them more apparent. In
some cases it is safer to cut carefully about the point of passage of the
root through the pia, leaving a bit of the membrane attached thereto.

As suggested on a previous page, it is often as well to leave the
roots longer on one side than the other, but the choice may be
determined mainly by the degree of success in the various pers
tions which have been described.

REMOVAL OF THE BRAIN. 431

§ 1109. Other Methods of Removing the Brain.—The following methods are sim-
pler and more expeditious than the preceding, but less satisfactory in some respects.

(A) By Nipping away the Calva (Vault of the Cranium).—This method is especially
adapted for the rapid exposure of the dorsal and lateral aspects of the hemispheres or the
cerebellum. When, for example, the brain of a recent or alcoholic specimen of some rare
animal is believed to be so soft that extraction by the usual method is not feasibie, a
drawing or photograph can be taken so as to represent at least the form, and the arrange-
ment of the fissures.

Instruments and Materials.—These are the same as for the
method already described (§ 1099).

Decapitation.—This is to be performed as directed in § 1101, and
the eyes, zygomata and temporal muscles removed.

§ 1110.—Eeposure.—With the large or medium nippers cau-
tiously penetrate the dorso-lateral aspect of the cranium, but with-
out piercing the dura. Pass the tracer between the bone and the
dura at all sides, keeping the point away from the brain; then
remove so much of the bone as is separated. When the orifice is
sufficiently enlarged, employ the probe or the handle of a scalpel
in place of the tracer. If the adhesions along the meson are very
firm, remove the bone on both sides, and divide them with the
arthrotome or scalpel.

In exposing the cephalic part of the hemispheres, the large
Frontal sinuses (Fig. 56, 59, 60, § 524) will be opened; note the
density of the ectal layer (tabula externa) of the cranium, and the
-elliptical orifices of the infundibula.

If the hemispheres only are to be exposed, or if it is desirable to
preserve the facial region, the dura may be divided with the scis-
sors along the margins of the bone, and the falx (Fig. 88) carefully
cut near the cephalic and caudal ends of the hemispheres, so as to
permit the removal of the dorsal dura. The lateral aspects of the
hemispheres may be exposed so far as desired, the olfactory crura
(Pl. I, Fig. 2) may be divided, and the hemispheres together with
the parts covered by them removed by holding the head so that its
frontal region tends to fall out, and successively dividing the JJ.
optici, the infundibulum and the other nerves as they appear at
the base of the brain, and lastly the crwra cerebri.

§ 1111. Commonly, however, the removal of the dura should be
postponed, and the olfactory lobes should be carefully exposed by
the removal of the thin bones which surround them; this is of
course facilitated by removing the entire maxillary region as directed
in § 1102.

432 ANATOMICAL TECHNOLOGY.

The caudal regions of the hemispheres rest upon the bony ten-
torium (Fig. 59, 88, § 552); note that the dura is continued upon
its surface and closely attached, but quite independent of it.

Remove the swpraoccipitale (§ 1013), leaving the dura upon the
cerebellum if possible, and then the Crista lambdoidalis and the
parts of the parietalia between the latter and the attachment of
the tentorium. The latter may then be nipped at each side as
directed in § 1103, and the central part removed. The tentorial
dura commonly adheres so closely that it must be removed likewise
by snipping it along the attached border of the tentorium. In
removing it, care must be taken not to injure or tear away the
conarium (Pl. II, Fig. 4, en.). The entire dura so far as exposed
may now be lifted as directed above.

Remove more of the right side of the skull so as to expose the
Lobulus hypocampe (P1, I, Fig. 2, Ll. hmp.); the perioticum (Fig.
59, pro.) should be cracked with the nippers and removed in small
fragments.

§ 1112. Removal.—Hold the head so that the right side of the
brain tends to fall out of place. The dextral nerves are to be di-
vided with the scissors or small scalpel, beginning with the most
caudal. If the hypophysis is to remain attached to the brain, the
division of the optic and trigeminus nerves should be deferred until
after it is dislodged or the bone is nipped from about it. Finally,
the sinistral nerves may be divided and the brain allowed to fall into
the brine.

§ 1113. With some modifications, the method just described is well adapted to the
removal of the brain from young human subjects. If the skull cannot be cut wiih the
nippers or bone scissors, it may be trephined in various places and the intervening areas
broken away. The dura should be retained as long as possib!e, and the entire head should
be floated in strong brine so that the brain may not bear its own weight at all. If tle
head is still attached to the body, the latter may be laid upon a box as high as the dish
so that the head may hang over the side of the latter.

§ 1114. (B) By Hemisection of the Head with a Saw.—The advantages of this
metiiod are :—(1) It is comparatively expeditious ; (2) the skull may be preserved ; (8) the
brain may be hardened in sitw, safely transported if desired and removed at a future time.

The two following objections are more apparent than real :—

(1) The skull is “ mutilated.”—On the contrary, for nearly all purposes of study, to
halve a skull is to double its value. Even if it is to be mounted with the skeleton or within
the skin, the two halves may be readily conjoined.

(2) The brain is injured by the saw.—If the hemisection is accurately mesal, the only
parts really destroyed are the conarium and crista ; all other parts which cross the meson
are recognizable, and the mesal aspects of the hemispheres are often untouched. If it be

REMOVAL OF THE BRAIN. 433

especially desirable to preserve the mesal surface of one hemisphere and the parts upon
the meson, the plane of section may be 1-2 mm. laterad (usually sinistrad) of the meson.
The lateral incisor will be destroyed unless previously removed ; but the rest of the skull
will be unharmed, and its meson will be available for study.

§ 1115. Instruments and Materials. — The same as for the
method first described (§ 1099), with the exception of the nippers,
and with the addition of the small back saw (§ 152) and the macrvo-
tome (Appendix).

§ 1116. Decapitation.—Remove the skin as directed in § 1101 ;
if the skin is to be mounted, divide it only from the dextral angle
of the mouth.

With the arthrotome divide the JZ. temporalis along the dorsal
margin of the zygoma and the caudal margin of the orbital process
of the O. malare, and dissect up the muscle for 1-2 cm.

This will expose the end of the Pre. coronoideus of the mandi-
ble; cut about it so as to free it from muscular and tendinous
attachments.

Separate the masseter (Fig. 67) from the ventral border of the
zygoma, cutting to the Pre. coronoideus. At a point nearly mid-
way between the meatus aud. and the orbital process of the malar
is situated the Arthron temporo-mandibulare ; determine its exact
position by pressing with the finger while the mandible is moved in
various directions. Open the arthron as directed in § 1101.

Ventriduct the mandible and cut any remaining attachments;
then proceed as directed in § 1101.

§ 1117. Mesal Hemisection.—With the arthrotome cut between
the two mesal incisor teeth and between the nasal bones; also upon
the meson at the Crista lambdoidalis and the caudal border of the
O. basioccipitale.

Adjust the slide so that when the head is forcibly pressed against
it the cuts just made coincide with the slit and groove of the macro-
tome. Rest the head with the canine teeth in the rebate, hold the
saw obliquely so that it runs in the slit and cuts through the facial
region. Then hold the saw more, nearly horizontal; finally, place
the skull flat upon the board and complete the hemisection with
long, steady strokes.

§ 1118. Lateral Hemisection.—If it is desirable that the meson
should be absolutely uninjured, remove a mesal incisor, and make
the initial guiding cuts through the periosteum about 1 mm. laterad
of the meson, so that the saw may pass through the vacant socket

28

434 ANATOMICAL TECHNOLOGY.

and through corresponding ogee upon the basi- and supraoccipital
bones.

§ 1119. As already indicated (§ 1114), the brnix may be har-
dened while in the cranium. Each half should be loosened a litile
as presently directed, and 95 per cent. alcohol injected between the
dura and the brain at two or three points. The half heads may
then be placed in 62-67 per cent. alcohol for two days and then
transferred to 95 per cent.

Usually, however, the brain should be removed (§ 1121), and the
dish of alcohol should have a flat bottom, or a piece of flat glass
should be placed in it, so that the hemiencephala may rest upon
their mesa. The operation will be facilitated by reference to a
hemicranium or to a figure of its ental aspect.

§ 1120. Weighing.—(A) Direct method :—As soon as the hemi-
encephala are in the normal saline solution, lift them out by means
of a slip (§ 95), upon which their mesa should rest, let the liquid
drain off, and place them, still upon the slip, upon the weighing
pan. Upon the other pan place a similar slip which has been
dipped in the same liquid.

(B) Indirect method :—Just before removing the brain, and after
snipping off the falz, weigh the two halves of the head. Weigh
the hemicrania immediately after the removal, and the difference
will represent the weight of the brain.

§ 1121. Removal.—Wash the mesa with a gentle stream of water,
or by movement to and fro in a dish of water. If the falx (Fig. 88)
is upon this side, grasp the edge with the forceps, and snip it along
its attachment to the skull. Note the position of the tentoriwm, of
the fossa olfactoria, and of the foramina upon the prepared skull ;
also, upon a figure, the ectal origins of the cranial nerves.

Hold the skull with the venter upward, and gently push the
medulla mesad with the tips of the scissors. Cut the WV. hypoglos-
sus close to the dura. Successively cut the VV. accessorius, vagus
and glossopharyngeus as they enter the Fm. jugulare. Tilt the
skull so as to permit the slight dislodgement of the meten. and epen.
and divide the VN. auditorius and facialis ; this will allow the
small Lobus appendicularis to leave its fossa. Cut the WV. abdu-
cens and the WV. trigeminus, with the tracer and scissors dislodge
the hypophysis, and cut the J. opticus. Lastly, divide the VJ.
trochlearis and oculomotorius.

THE ZINC CHLORID PROCESS. 435

Turn the cephalic end upward, and very carefully dislodge the
Lobus olfactorius. When this is done, the cephalic end of the
hemisphere will be easily freed from the dura. Hold the skull with
its venter down over the normal salt solution, and let the brain roll
into it.

§ 1122. Hardening.—For a few hours the hemiencephala should
rest upon their mesa; then a little bed of absorbent cotton should
be made for each, so that it may rest with the meson uppermost
and yet not be distorted.

After two days transfer to 95 per cent. alcohol, changing the
position as above.

§ 1123. The Zine Chlorid Process.—The preservation of brains by means of a solution
of chlorid of zinc is mentioned or more or less fully described by Gratiolet (A, II), Bischoff
(12, 11), Giacomini (2 [abstract in Jour. of Anat. and Phys., XIII]), Rolleston (7) and
Osler (2, 2).

Onur own experience is not yet sufficiently extensive to enable us to form an opinion
respecting its merits, and we here give (slightly modified verbally) the condensed direc-
tions which accompanied the admirable preparations of the human brain exhibited by
Osler at the meeting of the Am. Assoc. Adv. Sci., 1879, and substantially reproduced in
his second paper (2). .

“ (1) Immerse in a zinc chlorid [saturated] solution (‘ Burnett’s’ will answer). Turn
two or three timesa day. On the second day remove the pia. Let it remain until it no
longer sinks (8-10 days).

“ (2) Immerse in alcohol of commerce [95 per cent.] for 10-12 days, turning often to
prevent distortion.

*‘(8) Immerse in good glycerin to which has been added ‘1 per cent, of carbolic acid.
Let it remain until it sinks to the level of the liquid.

**(4) Set aside for several days until the surface is dry. Then cover with several layers
of gum-elastic varnish.”

§ 1124. Injection of the Oelie.—(A) With alcohol.—When the ccelie and plexuses are
to be studied, it is an advantage if the former have been first filled with strong alcohol.
This is most readily done after the entire brain has been placed in the weaker alcohol
(§ 1105).

Gently detach the hypophysis with the forceps, or leave it attached by a part of the
infundibulum. Then fill a small syringe with 95 per cent. alcohol, apply the outlet (with-
out a canula) to the Wm. infundibuli, and inject slowly until the Z/. hypocampa (P|. MI,
Fig. 3) is seen to swell sass Repeat the operation several times at intervals of 1-3
hours.

§ 1125. (B) With plaster.—This is for the sake of obtaining a cast of some part of the
celiz. It is best done while the brain still rests in the calva (§ 1103). See description of
Fig. 119. This method was employed by us before Welcker’s method of injecting wax was
known to us (Z [abstract in Jour. Anat. and Phys., XIII, 283]).

After the injection the brain should remain wholly undisturbed for at least half an hour.
The parts about the Hm. infundibuli, constituting the floor of the diaccelia, may then be
gently cut away with scissors so as not to break the cast. It is probable that a fracture

436 ANATOMICAL TECHNOLOGY.

will occur at the porte, but the parts may be reunited with glue and mounted upon glass
under a watch glass so that the separated parts are contiguous,

§ 1126. Injection of the Plexuses.—The larger arteries of the brain are filled when
the cephalic region of the body is injected with plaster (§§ 352-367).

For the special study of the plexuses, gelatin or Berlin blue may be injected from the
aorta as follows :—

Expose the thoracic vessels as directed in § 918, and note their positions and connec-
tions as shown in Fig. 101, 102.

Ligate the aorta near its base, the A. subclavia sinistra near the aorta, and the A. sub-
clavia deatra near its junction with the A. carotidea, Open the aorta peripherad of the
place of origin of the A. subclavia sinistra, expel any blood, and inject cephalad.

A MACROSCOPIC VOCABULARY OF THE BRAIN.

§ 1127. ABBREVIATIONS OF THE GENERAL NAMES.

Ar.—Area. F.—Fissura. Pz.—Plexus.
0.—Ceelia, Fm.—Foramen., R.—Recessus.
Olm.—Columna. Fn.—Funiculus. Rg.—Regio.
On.—Canalis. Fs.—Fossa. Rax.—Radix.
Cp.—Corpus. Ine.—Incisura. Si.—Sulcus, - «
Or.—Crus. L.—Lobus. Spt.—Septum.
Crs.—Crista. Li.—Lobulus. T.—Tuber.
Cs.—Commissura. N.—Nervus. Tr.—Tractus.
Em.—Enminentia. Pt.—Portio. Ti.—Tela.

§$ 1128. List of ABBREVIATIONS OF THE SPECIAL NAMEs,

In this list are given only the names adopted in this work ; the synonyms are given in
the descriptions which occur later in the alphabetical order of the names.
Those marked az. are mesal or azygous ; the rest are in pairs.

a—Aula, az.

abn.—Albicans, (Corpus).

alb.— Alba, (Substantia).
apz.—Auliplexus.

arb. vt.—Arbor vite, az.
arch,—Arachnoidea.

Ar. cr.—Area cruralis, az.

Ar. ier.—Area intercruralis, az.
Ar. el.—Area elliptica.

Ar. ov.—Area ovalis,

Ar. ppn.—Area postpontilis, az.

Ar. prch.—Area prechiasmatica, az.

Ar, spt.—Area septalis.

ca.—Carina, az.
cb.—Cerebrum, az.

cbl— Cerebellum, az.

ced. s.—Cauda (Corporis) striati.
cel. m.—Cella media.
ch.—Chiasma, az.
cin.---Cinerea, (Substantia),

cl.—Callosum, (Corpus), az.
clce.—Calcar. Not in the cat.
clv.—Clava.

Clim. d.—Columna dorsalis (myelonis).
Clim. f.—Columna fornicis.

Cm, i.—Cim. lateralis (myelonis).
Clm. ».—Clm. ventralis (myelonis).
emb.—Cimbia.

en.—Conarium, az.

Cn. ce.—Canalis centralis (myelonis), az,
ent. ov.—Centrum ovale (minus).

Cr. cb,—Crus cerebri.

Cr. ol.—Crus olfactorium.

Crs. f:—Crista fornicis, az.

Cs. f —Commissura fornicis, az.

Cs. h.—Commissura habenarum, az
ctx.—Cortex.

d.—Dura (mater).
de.—Diaceelia, az.
Dec. py.—Decussatio pyramidum.

MACROSCOPIC VOCABULARY OF THE BRAIN. 437

den.—Diencephalon, az.
dlt.—Delta (fornicis), az.
dpx.—Diaplexus.
dil.—Diatela, az.

Him. au.—Eminentia auditoria,
end.—Endyma.
epe.—Hpiceelia, az.
epen.—Epencephalon, az.

F. a.—Fissura anterior.

F. an.—Fissura ansata.

F. ef.—Fissura confinis.

F. cl.—Fissura callosalis.

F. cor,—Fissura coronalis,

F. cr.—Fissura cruciata.

F. dg.—Fissura diagonalis.

f, di.—Fissura dorsilateralis (myelonis).

F. dms.—Fissura dorsimesalis (myelonis),
az.

F. fm.—Fissura fimbrie.

F, fl.—Fissura falcialis.

F. hmp.—Fissurg, hypocampe.

F. in.—Fissura intermedia.

F, 1.—Fissura lateralis.

F. In.—Fissura lunata.

F’. mi.—Fissura medilateralis.

F. mr.—Fissura marginalis.

F. ol.—Fissura olfactoria.

F. p.—Fissura postica.

F. per.—Fissura postcruciata.

F. pmr.—Fissura postmarginalis,

F. prd.—Fissura postradicalis,

F. prh.—Fissura postrhinalis.

F. prrd.—Fissura preradicalis.

F. ps.—Fissura postsylviana,

F. rh.—Fissura rhinalis.

F. s.—Fissura Sylviana.

F. sfit.—Fissura subfalcialis.

F. sp.—Fissura splenialis.

F. so.—Fissura superorbitalis.

F. 8ss.—Fissura supersylviana.

F, vl.—Fissura ventrilateralis (myelonis).

F. oms.—Fissura ventrimesalis (myelonis),
az. :

f.—Fornix, az.

fle.—Flocculus.

Fm. ce-—Foramen cecum, az.

Fm. cn.—Foramen conarii, az.

Fm. inf —Foramen infundibuli, az.

JSmb.—Fimbria.

fscl.—F asciola,
g-—Genu, az.

h.—Habena.
hem.—Hemisphera.
Amp.—Hypocampa.
hmspt—Hemiseptum (cerebri).
hph.—Hypophysis, az.

Ine. hmp.—Incisura hypocampe.
inf.—Infundibulum, az.
inop.—Interopticus. Not in the cat.
ins.—Insula,

it.—lIter, az.

L 1.—Lobus lateralis (cerebelli).

LL. ol.—Lobus olfactorius.

LL. tmp.—Lobus temporalis.

Ll. ap.—Lobulus appendicularis (cerebelli).
Ll. hmp.—Lobulus hypocampe.

lm. alb.—Limes alba.

im. cin.—Limes cinerea, 7
lg. e—Liquor cceliarum.

ly.—Lyra, az.

mcs.—Medicommissura, az.
mcu.—Medicornu.
mpd.—Medipedunculus, az.
msc.—Mesoccelia, az.
msen.—Mesencephalon, az.
mte.—Metaceelia, az.
mten.—Metencephalon, az.
mtpx.—Metaplexus.
mttl.—Metatela, az.
my.—Myelon, az.

NV. abd.—Nervus abducens (vi).

JV. ae.—Nervus accessorius (xi).

NV. au.—Nervus auditorius (viii).

NV. f—Nervus facialis (vii).

NV. gph.—Nervus glossopharyngeus (ix).
NV. hg.—Nervus hypoglossus (xii).
JV. ocm.—Nervus oculomotorius (iii).
JV. ot.—Nervus olfactorius (i),

LV. op.—Nervus opticus (ii).

JV. tr.—Nervus trochlearis (iv).

NV. trg—Nervus trigeminus (v),

NV. v.—Nervus vagus (x).

o0b.—Obex.
olw.— Oliva.
op.—Opticus, (Lobus),

438 ANATOMICAL TECHNOLOGY.

p.—Porta. R. prpn.—Recessus prepontilis, az.
pi.—Pia (mater). Rg. a.—Regio aulica, az
pes.—Postcommissura, az. rhe.—Rhinoceelia.
peu.—Postcornu. Not in the cat. rhen.—Rhinencephalon, az
pgn.—Postgeniculatum, (Corpus). rm.—Rostrum, az.

po. ol,—Pero (olfactorius), 7p.—Ripa.
pop.—Postopticus, (Lobus). rst.—Restiforme, (Corpus).
pn.—Pons (Varolii), az. Rez. in.—Radix intermedia.
ppd.— Postpedunculus. Rx, 1.—Radix lateralis.
ppyf.—Postperforatus, (Locus), az. Rez. mt.—Radix motoria.
ppx.—Portiplexus. Rez. ms.—Radix mesalis.
pre.—Proceelia. Ra. sn.—Radix sensoria.
pres.—Precommissura, az.

preu.—Precornu. 8.—Striatum, (Corpus).
pren.—Prosencephalon, az. Sl. h.—Suleus habene.

Sl. ic. .—Suleus intercruralis lateralis.

prgn.—Pregeniculatum.
S. ic. ms.—Sulcus intercruralis mesalis, az.

prpd.—Prepedunculus.

prpf.—Preperforatus, (Locus). Si. é,—Suleus limitans.
prpx.—Proplexus. Sl. trd.—Sulcus triradiatus, az.
ps. ol.—Pes (olfactorius). sp.—Splenium, az.

Spt. lu.—Septum lucidum (cerebri), az

Pt. d—Portio depressa (preperforati).
str. Ing—Stria longitudinalis (callosi),

Pt. den.—Portio diencephalica (cruris cer-

= ebri). ‘ , : t—Terma, az. s
SSE Renee NOE I as 37 Tabarentnte aaa
cerebri). : ’ T. cin.—Tuber cinereum, az.

Pt. p.—Portio prominens (preperforati). th.—Thalamus
py.—Pyramis. Tr. op.—Tractus opticus.

pec. —Paeudoccelia, ae. Tr. prh.—Tractus postrhinalis.

¢~Qusdrens Tr. rh—Tractus rhinalis.

tz.—Trapezium,
r —Rima. ol.—Velum (interpositum), az
R. a.—Recessus aule, az. om.—Vermis, az.
R. op.—Recessus opticus. vv.—Valvula, az

§ 1129. Most of the above names are those in common use, with the omission of super-
fluous elements like corpus, and the genitives of the names of more comprehensive parts,
Most of the apparently new names will be found to be old acquaintances under such thin
disguises as translation, transposition, abridgement, and the substitution of prefixes for
qualifying words. In a few cases the old names are wholly discarded for briefer new
ones (e. g., cimbia for Tractus transversus pedunculi). Most of the new names, however,
refer to parts apparently unobserved hitherto (e. g., erista, carina, delta), or to parts which
—although probably observed—seem not to have been se sabe as needing a special
designation (e. g., aula, quadrans, pero).

For the names of the segments, cceliz, tele and plexuses, see § 1063.

So much of each name as immediately follows the abbreviation is regarded as a suffi-
cient designation of the part under ordinary circumstances ; sometimes it may be necessary
to add the words in parenthesis.

The names are tabulated according to segments in § 1138.

\

FEATURES OF THE MAMMALIAN BRAIN. 439

THE ENCEPHALIC SEGMENTS IN THE CAT.

§ 1130. The recognition of the several segments is less easy than
with the frog in some respects on account of certain features of the
mammalian encephalon.

§ 1131. Differences between the Brains of the Cat and the
Frog.—In a general way these have been indicated already (§§ 1055,
1056) ; they may be more definitely stated as follows :—

(1) In the cat the cceliz are irregular in form and relatively
reduced in extent (Fig. 113; Pl. I, Fig. 4).

(2) The parietes are relatively thicker, and more differentiated
as to both contour and structure (Fig. 113; Pl. II, Fig. 4; Pl. ITI,
Fig. 13). |

(3) With several segments the dorsal portion (roof) is much
more extensive than the ventral (floor), (Fig. 117; Pl. II, Fig. 4).

(4) The longitudinal axis of the entire brain presents a decided
Jiexure, the convexity of which is dorsal and coincides in position
nearly with the mesencephalon (Fig. 88).

(5) The dorsal portions of two segments (epencephalon and pros-
encephalon) are so greatly enlarged as to cover all the others except-
ing parts of the metencephalon and rbinencephalon, the extremes
of the series (Fig. 88, 104, 117; Pl I, Fig. 1, 2).

(6) In addition to the Amphibian commissures (chiasma, postcommissura, precommis-
sura), there are in the cat’s brain more or less distinct fibrous fasciculi constituting other
commissures—longitudinal (Crura cerebri, Pl. II, Fig. 3, Pl. III, Fig. 11; Crura olfactoria,
Pl. UW, Fig. 3,4; postpedunculi, prepedunculi) ; transverse (pons, Fig. 117; Pl. I, Fig. 3,
pn. ; decussatio pyramidum, medipedunculi, Commissura fornicis, P1. IV, Fig. 14, es. f.) ;
and oblique (fornix, Pl. IV, Fig. 14, f.).

(7) Between the apposed surfaces of the thalami is ‘established a connection, the medi-
commissura (Fig. 122; Pl. II. Fig. 4, mes.), which occupies a large portion of the diaccelia.

(8) The apposed wisrlstie of the hemispheres are connected along a slightly curved line
by a thick band of fibers, the callosum (Fig. 104, 115; PL. III, Fig. 13, Pl. IV, Fig. 15, e/.),
the largest and presumably the most important of the commissures.

(9) The dorsal aspect of the mesencephalon presents a transverse furrow, distinguish-
ing a cephalic pair of lobes, the optici proper, from a caudal pair, the postoptici (Fig.
114; Pl. Ill, Fig. 7); hence the bigeminum of the frog becomes the quadrigeminum of
the cat.

(10) The lateral aspect of the diencephalon presents at least two elevations, postgenic-
ulatum and pregeniculatum (PI. III, Fig. 7,9, pyn., prgn.).

(11) Of the diaccelian roof, the membranous part (déatela, Pl. TII, Fig. 10) is relatively
more extensive, while the nervous part (postcommissura, Pl. II, Fig. 4, pes.) is corre-
spondingly diminished ; concomitantly the conarium is attached near the caudal end of
the diencephalon and is retroverted so as to rest upon the mesencephalon.

440. ANATOMICAL TECHNOLOGY.

(12) Each lateral half of the rhinencephalon consists of a Lobus olfactorius connected
with the prosencephalon by a distinct Crus olfactorium (PI. II, Fig. 3, 4, Cr. ol.).

(18) Each proceelia may be subdivided, somewhat vaguely, into a central cella media
(Pl. IV, Fig. 15, cel. m.), and two curved prolongations, the precornu (PI. II, Fig. 121,
Pl. IV, Fig. 15, 16, preu.), and the medicornu (Pl. IV, Fig. 15, 17, 18, mew.)

(14) Into each cornu projects a decided eminence. That of the preecornu is the stria-
tum (Pl. IV, Fig. 15, 16, s.), a thickening of the parietes. That of the medicornu is the
hypocampa (Pl. IV, Fig. 15, 16, Amp.), which is chiefly an involution or folding of the
parietes (Fig. 121).

(15) In addition to the atrophied portions of the ccelian parietes noted in the frog, the
proper nervous substance of the hemisphere is abrogated along a line from the porta to
near the tip of the medicornu, constituting the rima or ‘‘ fissure of Bichat” (Fig. 121; PL
IV, Fig. 14, 17, R.). Along this line enters the larger portion of the proplexus.

(16) As in Menobranchus, there are metaplexus, diaplexus and proplexus, the latter
two being continuous through the intermediation of the auliplexus and portiplexus.

(17) The surface of the cerebellum is convoluted, presenting numerous thin folds
(lamine) with intervening fissures (Fig. 104, 117; Pl. I, Fig. 1, 2).

(18) The surface of the hemispheres is also convoluted, presenting a limited number of
fissures arranged according to a somewhat definite pattern (Fig. 124, 125; Pl. I, Fig. 1, 2).
Most of the fissures involve only a certain depth of the mass, but the /. hypocampa, “* hip-
pocampal fissure,” represents an involution of the entire thickness of the parietes (Fig.
121, 125; PI. IV, Fig. 15,17, F. hmp.).

(19) With the cerebellum and hemispheres, most of the cinerea is located near or at
the surface, constituting a cortex (PL. II, Fig. 4, Pl. IV, Fig. 14,15). The extent of the
cortex is of course increased by the convolutions.

Fig. 113.—Ventral exposure of the ceeliz ;
preparation No. 458, Museum of Cornell Uni-
versity. Compare with Fig. 110.

Objects.—To show (A) the general succession
of the celiz; (B) the relations of the porte to
the aula and proccelie ; (C) the thickness of the
parietes and concomitant reduction of the ccelie ;
(D) the undulations of the celian roofs.

Preparation.—From the ventral aspect of a
well hardened brain successive slices were re-
moved with the large scalpel until the porte and
Canalis centralis were exposed. With the Char-
riére scalpel there were excavated successively so
much of the various segments as to expose the
entire series of ccoelie, excepting the rhinoccelie,
the rhinencephalon having been removed.

On the right (left of the figure) the convexity
Fig. 118,—VENTRAL EXPOSURE OF of the striatum was cut off. On the other side

THE Camelia; x1. enough more of the hemisphere and thalamus
was removed to expose the proplexus and thus
throw the preecornu into direct communication with the medicornu.

Explanation.—Most of the names are written in full, and the parts mentioned are
described elsewhere.
On. ce.—Canalis centralis myelonis.

DORSAL ASPECT OF THE MESENCEPHALON. 441.

Dien., epen., mesen., meten. are abbreviations. of ‘diencephalon, etc. So much of the
preparation as is not included therein belongs to the prosencephalon.

Pgn.—Postgeniculatum. Th—Thalamus.

The sides of all the ceeliz are beveled off so as to expose their roofs more clearly. The
widest portion is the metaccelia, whose proper roof (metatela) is so thin that the lamine
of the overhanging cerebellum show through it.

The epiccelia presents two very different portions—a caudal, which is short but wide
and high, reaching up into the cerebellum (PI. II, Fig. 4), and a cephalic, longer but nar-
rower and lower, excepting at its cephalic end, where its roof, the valvula, rises to join
the postoptici.

The succeeding contracted portion -represents the mesoccelia ; the next mesal cavity
is the diaceelia, the roof of which presents the two parallel diaplexuses, diverging in the
aula to connect through the porte with the proplexuses.

On the right (left of the figure) the crescentic line representing the transection of the —
medicornu should reach the end of the line indicating the boundary between the hemi-
sphere and the postgeniculatum ; see Fig. 121.

The membranes and the relative areas of alba and cinerea are not shown.

Fig. 114.—Dorsal aspect of the mesencephalon,
exposed by the separation of the cerebellum and he misphas rae
hemispheres ; from Prep. No. 390, M. C. U. gle

Objects.—To expose (A) the dorsal aspect of the
mesencephalon, the cephalic aspect of the cerebel-
lum and the caudal aspect of the hemispheres ; (B)
the origin of the NN. trochleares from the cephalic
part of the valvula (vv.) ; (C) the caudal position and
retroversion of the conarium.

Preparation.—The fresh brain was carefully held
and the caudal portions of the hemispheres gently
pushed cephalad, the attachments to the mesencepha-
lon being divided with the tracer, until the conarium
was exposed; then the cerebellum was in like man-
ner tilted caudad, care being had not to tear the
delicate valvula.

By the above operations the natural encephalic Fie. 114%*—DorsaL ASPECT -OF
flexure was so exaggerated as to bring the ventral THE MESENCEPHALON, WITH
aspects of the crura olfactoria and the metencephalon SOME ADJACENT PARTs; x1.
into contact. The brain was secured in this condition
upon a bed of wet cotton by pushing cotton against it, and covered with 95 per cent.
alcohol. |

Explanation.—The names are written in full, excepting ov. for valvula. The furrow
between the optici is not sufficiently distinct, and the word postoptici obscures the fact
that the elevations so named are separated by a somewhat wide and flat valley rather than
by a narrow depression..

In the preparation, the infundibuliform mesoccelian orifice is visible through the trans-
parent valvuia. Compare PI. III, Fig. 7.

Fig. 115.—The callosum after removal of the dorsal portions of the cerebellum and
hemispheres ; from Prep. No. 540, M..C. U.

Objects.—To show (A) the fact of the connection of the hemispheres by the callosum ;

442 ANATOMICAL TECHNOLOGY.

(B) the cephalo-caudal extent of the latter; (C) the manner of cleavage of the hemi-

spheres; (D) the irregular lamination of the cerebellum.
Preparation.—The hemispheres and Lobi olfactorii of a hardened brain were sliced to
near the level of the callosum and in a plane coinciding with the larger part of its course.
The slight portions overhanging the borders of the

lobé olf- callosum so as to constitute the FF. callosates (Fig. 116,
a ? qi 122; Pl. Ill, Fig. 13) were then pushed dorso-laterad
with the tracer; the torn surfaces so left are repre-

sented by the striated areas. On the right, a part of
the hemisphere was torn off so as to indicate the wave-
like arrangement of the fasciculi.

An oblique section was then made from opposite
the splenium through the caudal portion of the hemi-
spheres and the cerebellum, so as to expose the post-
optici.

Explanation.—The name is written lengthwise of
the callosum ; perhaps the line at each side represents
a stria longitudinalis. The curvature ventrad at the
genu and splenium is better shown in section (Fig.
116; Pl. Il, Fig. 14). The postoptici do not appear
distinctly, and no attempt was made to indicate the
areas of cerebral alba and cinerea, or of the pes, pero
Fie, 115.—DorsaL ASPECT OF oy ceelia in the rhinencephalon.

THE CALLOSUM AFTER PAR- § 1132. Preliminary Examination of the Basis
TIAL REMOVAL OF THE EncephaliiAs seen in Fig. 116, 118, and Pl. I,
HEMISPHERES; x1. Fig. 3, the base of the brain presents numerous parts

distinguished by their elevation, their subdivision,
their color or the direction of their fibers. Including the twelve cranial nerves, about
fifty different parts, more or less comprehensive, are named upon Fig, 116.

The cranial nerves are treated of in the next chapter. Of the remaining parts, the
beginner is advised to study first only those which have been observed in the Amphibian
brain, or which serve either as topographical landmarks or as aids in recognizing the limits
of the encephalic segments. Later, it will be desirable to identify each feature by the aid
of the figures (Fig. 118 ; Pl. II, Fig. 3; Pl. Ill, Fig. 11) and the detailed descriptions.

Fig. 116.—Diagram of the base of the brain, including the nerve roots.

Explanation.—The names are written in full. As suggested above, the following
parts are to be noted first :—

Myelon, expanding into the metencephalon.

Cerebellum, greatly enlarged and convoluted.

Hemisphere, still more enlarged and likewise convoluted.

Lobi olfactorii, elongated and in apposition, but not organically united.

Chiasma, Tuber cinereum, infundibulum, hypophysis, Crura cerebri (one of which
is designated on Fig. 116 by the word c7ws) and pons.

Of the parts just named, all but the last have been noted upon the mesal aspect of the
Amphibian brain, and are mentioned in the Table (§ 1069).

The pons is a wide and thick band of transverse fibers connecting the lateral lobes of
the cerebellum across the ventrimeson. It is likewise a prominent landmark, serving,
with the chiasma, to divide the entire basis encephali conveniently into three general
regions—caudal, Area postpontilis ; cephalic, Area prechiasmatica; and intermediate,
Area cruralis.

_ EXAMINATION OF THE BASIS ENCEPHALI. 443

a Post rkinalis

yroet

NV Cer vicati's,

Olum nn;

ventralis

SS
=
Fie. 116.—DIAGRAM OF THE BAsIS ENCEPHALI; x3.

It is to be observed that, notwithstanding the preponderance of the cerebellum and the
hemispheres, all the encephalic segments appear upon the ventral aspect, most distinctly
at and near the meson. On the left (right of the figure) the names of the prosencephalon
are written along its expanded dorsal portion, but upon the ventrimeson it may be

444 Sik ANATOMICAL TECHNOLOGY.

regarded as extending only from the middle of the chiasma to the diamond-shaped area
just caudad of the rhinencephalic Radices mesales.
The extent of the metencephalon coincides nearly with that of the pyramis.

§ 1188. Hemisection of the Brain.—The encephalic segments are more easily recog-
nized and examined upon a hemiencephalon than upon the entire organ because (1) all the
segments and most of the cceliw are then exposed ; (2) the parts can be’ more readily bent
upon each other or dissected apart.

Instruments and Materials.—A brain, symmetrical and well-hardened.; distorted speci-
mens may serve for dissections, but for the hemisection select the most perfect. Razor or
large scalpel, with very keen, smooth edge ; if the scalpel is used, it should be especially
sharp at the heel, which is usually neglected. A small dish or vial of alcohol, in which
the knife may be dipped. A piece of sheet. cork, or of soft wood free from knots, at least
6x4 cm., and preferably 16x 8. Remove from the brain any pins which may cross the
meson.

§ 1134. Upon a preparation or figure (Fig. 115, 116; Pl. II,
Fig. 4), note the position of the calloswm and the angle which it
forms with the dorsal and ventral surfaces of the brain.

Place the brain upon its basis, with its long axis coincident with
the length of the cork or the grain of the wood, and the cephalic
end of the brain to the left.

Dip the scalpel in alcohol, and grasp it bow-fashion. Introduce
’ the tip of the blade between the hemispheres at their highest part,
and gently push it ventro-cephalad until the point reaches the cork
a little in advance of the Lobi olfactorii, and the back of the blade—
if a scalpel is used—is about on a level with the dorsal margins of
the hemispheres. The blade then forms an angle of about 30
degrees with the cork, and its heel is a little cephalad of the cere-
bellum.

Grasp the brain gently but firmly as follows:—The pollex
should be on the left, against the lateral surface of the cerebellum
and the caudal part of the hemisphere; on the right the tips of the
index, medius and annularis press respectively upon the lateral
aspect of the cerebellum and the temporal and frontal regions of the
hemispheres. The minimus may be raised out of the way. The
pressure upon the two sides of the brain must be equal and uniform.

Draw the scalpel slowly caudad, keeping the convexity near the
tip constantly upon the cork, and the entire instrument at the same
angle until it emerges through the cerebellum and the medulla.

At the beginning of the hemisection, the edge of the scalpel
was firmly held by the closely approximated hemispheres, and
its edge rested on the callosum, so that the latter was probably
divided accurately on the meson. But a very slight initial deflec-

HEMISECTION OF THE BRAIN. 445

tion may have brought the blade out 1-2 mm. laterad of the ventri-
meson.

Ascertain the extent of the departure by apposing the two halves
of the brain and noting the position of the cut with respect to the
ventrimeson. If the cut and the meson coincide, the surfaces of the
two sides of the brain will be practically identical ; but according
to the degree of the separation there will be found a difference
which is sometimes so great as to be puzzling to the beginner,
especially since in these cases neither surface resembles that shown
in the figure.

After becoming somewhat familiar with the organ, it may be
well to make purposely a hemisection about 1 mm. laterad of the
meson, so that the commissures and other mesal structures may be
dissected out in relief ; but at the outset it is better to secure a
view of the mesal surface itself.

Select that half of the brain to which part of the other half is
attached, and hold it with the meson up and the base toward you ;
grasp the large scalpel bow-fashion, and apply the heel at the ven-
trimeson, upon the chiasma if it be the right half, or at the ventri-
mesal (‘‘ anterior median ”’) fissure of the metencephalon if the left ;
cut away from you with a long steady sweep, taking care not to cut
upon the other side of the meson. Certain parts of the surface may
require subsequent special treatment in order that the surfaces may
be fairly exposed.

§ 1135. Aside from detailed comparison of the surface with the
figures, the best test of the mesal surface is the exposure of the
series of mesal coelie, extending, as in the Amphibian brain (Fig.
111), in uninterrupted continuity from the ventro-caudal angle of
the cerebellum to a point dorsad of the chiasma. Just ventrad of
the cerebellum the lateral extent of the cavity, epiccelia, is con-
siderable, but at other points it is no more than 1-2 mm., so as to
appear on the mesal surface like a shallow depression. The most
obseure portion of the cavity is the cephalic part of the epiccelia,
where the lateral extent is considerable, while its vertical diameter
is very slight, and the roof, valvula, is quite thin. |

Fig. 117.—Mesal aspect of the left hemiencephalon ; a diagram enlarged from PI, II,
Fig. 4.

Explanation.—Upon this diagram are named nearly all the parts and surfaces which
are exposed by a mesal hemisection.

To avoid turning the volume in referring to it, the figure has been divided. Unfor-

446 ANATOMICAL TECHNOLOGY.

tunately, it is reversed as compared with Fig. 111 and Pl, II, Fig. 4. The cephalic part
of the valvula is represented much too thick.

§ 1136. Preliminary Inspection of the Mesal
Aspect.— Before entering into details, the student
should compare the mesal series of coelie in Fig. 116 we
with the same in Fig. 111, and recognize the following » ,

parts of their parietes by name, even although their ey Js r Ly

appearance may be quite unlike : cerebellum, valvula, ( B Wy

opticus, conarium, postcommissura, precommis-

sura, chiasma, Tuber cinereum. at lf Wp
The lateral ccelie, procelia and rhinoc@lia, do not )

appear, and the porta itself is not visible, but its posi- J yy Vv

tion coincides nearly with that of the little eminence

called crista, just cephalad of the medicommissure.

§ 1137. Surfaces exposed by Hemisection of the
Brain.—Four different kinds of surface appear upon
the mesal aspect of the hemiencephalon, and they
should be recognized and distinguished before the
details are examined :—

(1) Dorsad of the callosum the hemisphere is nat-

wral or free and covered by pia. Uyelo

(2) The several ccelie are lined by endyma, which Pyramis
likewise form a natural surface. Pn

(8) The commissures and other parts which extend XeeFRalon

across the meson have been divided and the resulting

surfaces are cut or artificial. With the callosum, precommissura and postcommissura,
chiasma, ental portion of cerebellum, etc., the parts are white in color and fibrous in
texture (alba), but the medicommissure, terma, ectal layer of cerebellum, etc., are cellu-
lar and formed by cinerea.

(4) Caudo-ventrad of the cephalic part of the callosum is a triangular area which is
naturally attached by connective tissue to the corresponding surface of the other hemien-
cephalon. This is the Area septalis. In man the surfaces are free, forming the lateral
boundaries of the pseudo-celia.

§ 1188. Segmental Arrangement of the Names of the Principal Parts of the
Cat’s Brain.—The Table upon pages 48 and 49 is intended to enable the student to learn
more readily the large number of names according to their respective segments, and to
see at a glance the relations which the parts bear to each other.

In each case, excepting perhaps the caudal portion of the prosencephalon, the part first
mentioned constitutes the principal mass of the segment.

The indenting of a name signifies that the part is a subdivision of the part named
above; for example, the striatum is a division of the hemisphere, and itself includes the
cauda striati.

In most cases the apposition of names in different columns signifies that the parts are
in some way correlated ; ¢. g., under epencephalon, the arbor vite is a surface exposed upon
hemisection of the cerebellum, and the pons is the great cerebellar commissure. Where
the parts are not correlated, the vertical line between the columns is reinforced by a short
vertical line ; ¢. g., between carina and ripa.

In the column headed suwperficies are also included the names of elevations, depressions,
recesses, sulci, and even cavities,

MESAL ASPECT OF THE BRAIN. 447

sncop holon Lreb buy,
8,

2.

1 eS Lobne aces

postper forotus ACY olfo
‘ LF 2¢ gn oe mesarsd

Ro : \ abe . av TS - \
or ant (3) tn . ad ee +
P / ipa 8 y , bree wereay,
nao AV Prosencephalon Rhimentephe
Fpencep “Seneepholan D eentephaalon P

Fie. 117.—DIAGRAM OF THE MESAL ASPECT OF THE LEFT HEMIENCEPHALON; x8,
The caudal part of the figure is upon the opposite page.

The fornix is difficult to classify. In some respects it and the fimbria seem to be
commissural.

Fic. 118.—D1aGRAM OF THE AREA CRURALIS; x2. This figure is enlarged and re-
versed from PI. III, Fig. 11, and the description of that figure may be consulted
for the details and for the mode of preparation.

448

ANATOMICAL TECHNOLOGY.

TABULAR ARRANGEMENT OF THE PARTS OF THE CAT’S BRAIN.

This Table differs from that upon page 409 mainly in that the names of the encephalic
ents, and of the ccelie, tele and plexuses thereof, are placed together above the

names of the particular parts, surfaces and commissures.

given in § 1180 et seg.

RHINENCEPHALON.

RHINOCELIA.

The synonyms of the names are

Partes.

Superficies.

Lobus olfactorius.
Pero (olfactorius).
Pes (olfactorius).

Crus olfactorium.
Radix mesalis.
Radix intermedia.

(not in cat ?)
Radix lateralis.

Limes alba.
Limes cinerea.

PROSENCEPHALON (Cephalic Portion, Paired).

PROCCELIA — PROPLEXUS.
Partes. Superficies, etc. Commissure.
Hemisphera. Centrum ovale. Callosum, az.
Centrum ovale majus, az. || Splenium, az.
Genu, az.
Rostrum, az.
Septum, az Area septalis.
Pseudo-ccelia (not in cat).
Striatum. Precornu. Przcommissura, az.
Cauda striati.
Insula. ; 3
pi Soran Medicornu. Fornix, t
ulus hypocampe. Fimbria.
Fosciol a.

Calcar (not in cat).

Gyri cerebrales.

Postcornu (not in cat).
Lyra, az
Prezperforatus.
Portio depressa.
Portio prominens.
Fissure cerebrales.

PROSENCEPHALON (Caudal Portion, Unpaired).
AuLA, Porta, Proca:L1a—AULATELA—AULIPLEXUS, PORTIPLEXUS, PROPLEXUS.

Partes.

Superficies, etc.

Commissure.

Terma,

Fornix, 4 (See § 1457.)
Columna fornicis.
Carina, az

Crista, az.

Fimbria.
Tenia.

~—

Ripa.
Delta, az
Aula, az
Recessus aule, az
Recessus opticus.
Rima.
Sulcus limitans.

Commissura fornicis, az.

TABULAR ARRANGEMENT OF PARTS OF THE CAT’S BRAIN.

449

DIENCEPHALON.
Draca@sLtraA — DIATELA — DIAPLEXUS.
Partes. Superficies, etc. Commissure.
Thalamus. Medicommissura, az.

Pulvinar (not in cat).

Habena.

Conarium, az.
Pregeniculatum.
Postgeniculatum.

Crus cerebri (portio dien-
cephalica).
Tuber cinereum, az.

Infundibulum, az.

Hypophysis, az.

Sulcus habene.
Foramen conarii, az.
Tractus opticus.

Quadrans.

Foramen infundibuli, az.

Postcommissura, az.
Commissura habenarum, az.

Chiasma, az.

Albicans. Sulcus triradiatus, az.
Postperforatus, az.
MESENCEPHALON.
MESOCCELIA,
Partes. Superficies, etc.
Opticus.
Postopticus.
Crus cerebri (portio siryinae Sulcus intercruralis later-
cephalica). alis.
Cimbia. || Sl. ic. mesalis, az.
EPENCEPHALON.
EPIce@Lta.
Partes. Superficies. Commissure.
Cerebellum, az. Arbor vite, az. Pons, az.
Lobus lateralis. Medipedunculus,
Lobulus appendicularis.
Vermis, az.
Valvula, az. | Postpedunculus,
Prepedunculus,
Foramen cecum, a2.
Recessus prezpontilis, az.
METENCEPHALON.
METAC@HLIA — METATELA — METAPLEXUS
Partes. Superficies, etc. Commissure.

Medulla, az.
p .
Oliva.

Tuberculum Rolando.
Restiforme.
Trapezium.
Eminentia auditoria.
Clava.

Obex.

Area postpontilis, az.

Area elliptica.
Area ovalis.

Decussatio pyramidum, az.

450 ANATOMICAL TECHNOLOGY.

§ 1139. Examination of the Encephalic Segments.—/nstru-
ments and Materials.—A hemiencephalon, well hardened ; the
condition of its lateral aspect may be disregarded. Large and
Charriére scalpels, both very sharp. Syringotome or tracer. Fine
scissors. Blowpipe. Coarse and fine forceps. Beaded bristles.
Small dish or wide-mouthed vial of alcohol, into which the brain
and the scalpels may be dipped.

In dissection of the brain, the scalpeils should be very sharp,
and dipped in alcohol just before each incision.

Rhinencephalon (examined first on account of its liability to
injury during the study of the other parts).—Ventriduct the Lobus
olfactorius so as to expose the dorsal aspect of the Crus ol.; also
the Fissura ol. (Pl. Til, Fig. 5, /&. ol.) on the ventro-cephalic sur-
face of the hemisphere in which rests the dorsal border of the crus.

At the junction of the crus with the lobus, note the slight promi-
nence of the softer ectal layer, the pero, from which directly arise
the olfactory nerves (Pl. II, Fig. 3, WV. ol.). Remove the pero
with the forceps and tracer, and note that there remains a thin
smooth lamina, the pes ol., which is partly fibrous and forms the
immediate continuation of the crus.

The rhinocelia will be more easily seen oe the dissection of
another specimen.

§ 1140. Metencephalon.—Of this segment, one part, the pyra-
mis, has been noted. Laterad of the cephalic part of the pyramis
is a quadrangular area, the trapezium (PI. I, Fig. 3, Zz.) ; laterad
of its caudal and longer portion are two elevations, here called from
their outlines, Area elliptica and Area ovalis.

The dorsal aspect of the metencephalon is overhung by the cere-
bellum. Tilt the latter cautiously latero-cephalad, using the tracer
to disengage from its ventral aspect the delicate metatela, the roof
of the metaceelia (Pl. III, Fig. 12, m#¢7.). Even if, in so doing, the
metatela is torn from its connection with the border of the metaccelia
(so as to produce a ‘‘ Foramen of Magendie,’”’ § 1082), it may usu-
ally be traced continuous with the ventral surface of the cerebellum
just caudad of the epiccelia.

Now tilt the cerebellum meso-cephalad and note the mass of
membrane and blood-vessels forming the metaplexus lateralis
(Pl. I, Fig. 4; Pl. III, Fig. 12, mépz.).

Upon removal of the metatela and metaplexus, there will be

EXAMINATION OF THE ENCEPHALIC SEGMENTS. 451

seen a transverse band (Tractus auditorius) passing from the Emi-
nentia auditoria across the wall of the metaccelia.

§ 1141. Hpencephalon.—Tilt the cerebellum caudo-laterad, so
as to expose the limits of the epiccelia. Note the distinction be-
tween its caudal portion, which extends dorsad into the cerebellum,
and the rest, which has for its roof only the thin valvula. Separate
the valvula from the cerebellum, noting the continuity of the two at
the caudal end of the former.

With the forceps and tracer tear and push off the lateral part of
the cerebellum so as to expose the medipedunculus, the continua-
tion of the pons into it. In like manner, remove the caudal part of
the cerebellum, and note a less distinct fasciculus, the postpedun-
culus, passing from the Tractus lateralis of the metencephalon to the
cerebellum just mesad of the medipedunculus. The prepeduncu-
lus is exposed by the removal of the cephalic part of the cerebellum ;
it forms the lateral wall of the cephalic part of the epicelia, and is
continuous with the base of the postopticus.

Push the tracer entad of the medipedunculus, and then divide it
with the scissors. Grasp the ventral piece and tear off the pons as
far as the meson. Note that the pons concealed the continuity of
the pyramis with the Crus cerebri.

§ 1142. Mesencephalon.—Note the slenderness of the mesocee-
lia, whence the names ¢¢er and aqueductus Sylvii.

Ventriduct the meten. and epen. so as to leave a space between
them and the hemisphere. Remove the caudal end of the latter by
a dorso-ventral incision corresponding with the convexity of the
splenium. On the cut surfaces, note the darker color of the ectal
cinerea, the cortex, as compared with the ental alba. There will
be exposed a cavity, the medicornu, and a rounded elevation, the
hypocampa. These may be disregarded for the present.

With the pollex tear away the Lobulus hypocampe (PI. I,
Fig. 3, Zl. hmp.) and so much of the hemisphere as readily comes
off with it; then cut off as much more as may be necessary to ex-
pose the Tractus opticus (77. op.).

The parts thus exposed will be found covered by pia, which
forms a distinct fold in the /. hypocampe (Fig. 121).

This covering of the mesencephalon and part of the diencephalon
is called the velum (interpositum). Remove it with the forceps,
beginning at the postopticus. Note the slender JV. trochlearis

452 ANATOMICAL TECHNOLOGY.

passing laterad and then ventrad just caudad of the postopticus
from its ectal origin on the cephalic part of the valoula.

Observe the contrast in form and position of the opticus and
postopticus. The latter is farther from the meson and more sharply
defined ; the opticus presents a more gradual slope to the meson.
Extending laterad from the lateral slope of the opticus, note the
cimbia, the ventral part of which crosses the crus in the Area cru- .
ralis (Fig. 116, 118; Pl. II, Fig. 3, and PI. III, Fig. 11, emb.). The
cimbia seems to indicate the boundary between the mesencephalic
and diencephalic portions of the crus.

§ 1148. Diencephalon.—Note the great dorso-ventral extent of
the diaccelia, the presence of the medicommissura (mcs.) in its dor-
sal part, and the absence of any distinct boundary between the
diaccelia and the aula.

The thalami constitute the lateral parietes of the diaccelia, and
its ventral and cephalic boundaries are sufficiently obvious, but the
dorsal require specification.

The most caudal part of the roof is formed by the postcommis-
sura (pcs.), which intervenes between the opticus and the cona-
rium (c7.).

Between the medicommissure and the fornix the most prominent
part, especially with an injected preparation, is a longitudinal
plexus, the diaplexus.

Lift the diaplexus with the tracer at about the middle of its
length and note that it is attached throughout by one edge, and
that it partly covers a ridge upon the mesal aspect of the thalamus.
This, the habena (/.), is widest near its caudal end, which joins its
platetrope by a slender band, the Commissura habenarum (Cs. h.),
just dorsad of the conarium.

The habena becomes narrower and less prominent cephalad and
disappears at the cephalic convexity of the thalamus, corresponding
with the dorsal limit of the porta.

Grasp the diaplexus with the fine forceps and gently pull upon it.
Note that it readily separates from the other parts excepting at the
ends. The ends are connected with somewhat large vessels, but the
precise arrangement is not clear to us. Recall the relations of the
diaplexus in Menobranchus (§ 1097), where it is free excepting at
the cephalic end.

Remove the diaplexus by carefully cutting the caudal and ce-
phalic connections, and note that it was attached to the ventral or

EXAMINATION OF THE ENCEPHALIC SEGMENTS. 453

ental aspect of a delicate membranous roof of the diaccelia, the
diatela (Fig. 122). . |

By slightly pushing the hemisphere away from the thalamus,
it will be seen that the diatela springs from the dorsal margin of the
habena, along a slight furrow, the Sulcus habene (SJ. h.), and
curves dorso-mesad to meet its other half from the opposite side.

§ 1144. On the lateral aspect, between the cimbia and the tractus
opticus, note a decided elevation, the postgeniculatum (Fig. 18;
Pl. III, Fig. 7, 9, pgn.). Ventrad of it is a ridge of the crus, partly
embracing a depressed area, the quadrans (Fig. 18; Pl. -III, Fig.
11, ¢.).

Ventriduct the parts still more, and trace the tractus opticus
into an expanded elevation just cephalad of the postgeniculatum.
This, the preegeniculatum (Pl. III, Fig. 7, 9, prgn.), is practically
continuous with the thalamus, the principal part of the diencepha-
lon, which has been seen above as the lateral wall of the diaccelia.
Note the absence of any distinct caudal protrusion of the thalamus,
such as forms the human pulvinar. At the meson, in the depres-
sion between the thalamus and the opticus, note the half of the
conariwm, more or less enveloped by the velum, and inclined cau-
dad from its attachment so as to rest upon the opticus.

By an incision beginning just dorsad of the callosum and ex-
tending laterad and very slightly dorsad, remove the dorsal portion
of the hemisphere. The features of the cut surface may be disre-
garded here ; the object is to permit what is left to be raised more
easily. On lifting this portion, note that its ventral surface presents
slight fissures and strize, trending latero-caudad. This is the fornix
(Pl. IV, Fig. 14, 7), including the lyra (/y.), the limits of which have
not been determined. Note that, for a short distance from the sple-
nium, the plane of the fornix coincides with that of the callosum,
but that it curves ventrad so as to become nearly vertical at its
cephalic end. The general shape of the fornix is triangular ; its
larger portion is the body, and the narrower cephalic end is the col-
umna. The band which forms its lateral border is the fimbria,
which, as will be seen later, is continued nearly to the tip of the
Ll. hypocampe.

Between the fornix and the diencephalon is a fold of pia, the
velum. When freed from the velum, note the difference between
the dorsal surface of the thalamus and the mesal surface already

454 ANATOMICAL TECHNOLOGY.

examined (§ 1043) ; the latter is entocelian and covered by endyma ;
the former is wholly ectoccelian (Fig. 122).

But, along the free border of the fimbria, the velum, or vessels
thereof, passes into the proceelia, covered by the endyma, whose
attachment may be noted along the entire length of the fimbria (Fig.
121). This solution of the continuity of the nervous tissue along
the border of the fimbria is the rima (Pl. IV, Fig. 14, 7.), and the
intruded border of the velum is the proplexus (PI. [V, Fig. 15, ppz.).

§ 1145. Aula and Porta.—Cut off the larger part of the fornix
with the corresponding portion of the callosum, gently push the
fornix from the thalamus, and note that, at about the junction of
the body with the columna, the adhesion of the velum to both for-
nix and thalamus ceases suddenly, and that the surfaces of both,
ventrad of the adhesions, are covered by the smooth endyma which
is characteristic of the cocelian cavity.

So much of the interval between the fornix and thalamus as lies
ventrad of the lines of adhesion is the porta. Its ventral limit is
formed by the continuity of the two masses (Fig. 123).

The adhesions coincide with the lines of reflection upon the in-
truded velum of the endyma from the columna and thalamus. The
slight space mesad of the porta is the aula, and the irregular cavity
laterad of the porta is the proccelia, which will be examined later.

So much of the brain as has not been specified appertains to the
prosencephalon.

§ 1146. Demonstration of the Proccelia, Rhinoccelia and Porta
(‘‘Lateral and olfactory ventricles and Foramen of Monro’’).—The
proceelia and porta have been incidentally exposed during the ex-
amination of the encephalic segments.. The following directions
deal particularly with their parietes and with the continuity of the
proceelia with the rhinoccelia.

Instruments and Materials —The same as for the examination
of the segments (§ 1139). The syringotome is preferable to the tracer.

For the most satisfactory study of the cceliz and the plexuses,
' the arteries should have been injected with gelatin (§ 1126) and alco-
hol thrown into the Foramen infundibuli (§ 1124). The following
figures should be consulted before and during the dissection: 117,
119-123 ; Pl. II, Fig. 4; Pl. II, Fig. 13; Pl. IV, Fig. 14, 15, 16, 19.

§ 1147. Opening the Cella Media of the Procelia.—Apply the
edge of the large scalpel along a line 2 mm. dorsad of the main part

DEMONSTRATION OF THE PROCQ@LIA. 455.

of the callosum, and make a slight incision. Then dip the scalpel
in alcohol, and cut horizontally along that line so as to remove the
dorsal part of the hemisphere.

On the surfaces so exposed. note the ental alba (centrum ovale)
and the ectal cinerea (cortex); also the undulations of the line of
their junction, according to the depth of the jisswres between the
gyrt. Slice the removed dorsal piece in various directions so as to
show the continuity of the cinerea.

If the surface of the alba of the ventral part is uniform in color
and continuous, remove successive slices, not more than .5 mm.
thick, until, about 5 mm. from the meson, there appears a group of
dark points ; the removal of another very thin slice will then expose
the summit of an arched cavity, the cella media of the proccelia,
and a slightly undulating convex surface, the cephalic part of
which is the fornix and the caudal the hypocampa (‘‘ hippocampus
major’’).

Opening the Medicornu and Exposure of the Hypocampa.—
Push the syringotome very cautiously latero-caudad between the
hypocampa and the cut edge which overhangs it, and then, with
the scalpel, remove a wedge-shaped slice so as to expose more of
the hypocampa. Repeat the operation, bearing in mind that the
direction of the hypocampa and of the cavity—the medicornu—into
which it projects, is successively caudad, laterad, ventrad, cephalad
and mesad ; see Fig. 119.

The anthropotomical terms indicative of these directions are backward, outward, down-
ward, forward and inward, the initial letters of which form the mnemonic word bodfi.

During this exposure of the hy pocampa, there is danger that some
part of its surface will be sliced off, and the syringotome should be
used as an explorer before each incision. When near the tip of the
Il. hypocampe, be especially careful not to cut too deeply ; the tip
of the cornu is here separated from the ectal surface by a very thin
lamina.

When the entire length of the hypocampa is exposed, pass the
convexity of the tracer along its caudal border, and then slice off the
overhanging portions of the caudal wall of the medicornu. Note
that the width of the medicornu varies somewhat, but that there is
no sign of the caudal prolongation which, in man, the monkeys,
seals and some cetacea, forms a postcornu. Note also two slight
oblique ridges which cross the hypocampa in opposite directions,

456 ANATOMICAL TECHNOLOGY. ©

and the existence of something like the terminal expansion which,
in the human brain, is called the ‘“‘ pes hypocampe.”’

§ 1148. Demonstration that the Hypocampa is only a Modified
Portion of the Procelian Parietes.—Carefully pass the tracer be-
tween the opticus and the caudal border of the hemisphere, and
rotate it so that the point may penetrate the hypocampa and appear
in the medicornu. Withdraw the instrument without disturbing
any connections ; see Fig. 121 and Pl. IV, Fig. 18, 19.

§ 1149. Opening the Precornu and EHaposure of the Striatum.—
From the roof of the proceelia, cephalad of the orifice first exposed,
remove a thin wedge-shaped slice, and thus more completely expose
the fornix, which is seen to be continued along the cephalic border
of the hypocampa as a flat band, the fimbria.

Cephalad of the fornix is a marked elevation, the striatum; that
part of the proccelia into which it projects is the precornu. Be-
tween the striatum and the fornix and fimbria is a depression, the
Sulcus limitans, into which projects a plexus, the proplexus. The
sulcus and the plexus may be traced along the cephalic border of
the fimbria to near the tip of the medicornu ; their relations will be
seen better at a later stage of the dissection.

Note that the cella media does not quite reach the meson, on
account of the continuity of the fornix and the hypocampa with the
callosum. As will be seen later, the only place where the proceelia
does reach the meson is at the bottom or mesal end of the Sulcus
limitans, where the porta communicates with the aula and thus
with the mesal series of coelie.

Exposure of the Mesal Aspect of the Striatum.—Along a line
passing dorso-ventrad about 2 mm. cephalad of the chiasma, make
an incision 1 mm. deep at the venter, its dorsal end reaching the
mesal border of the striatum, as already exposed.

From the mesal aspect of the olfactory lobe and cephalic. part
of the hemisphere remove a slice about 1 mm. thick, and then, with
the small scalpel, cut successively thin wedge-shaped slices so as to
expose the mesal aspect of the striatum and the cavity, the pre-
cornu, into which it projects. Note the somewhat sharply defined
ridge which separates the mesal from the dorsal surface of the stria-
tum, and the greater extent of the former.

§ 1150. Opening the Rhinocelia.—The ventro-cephalic angle of
the preecornu presents a slight funnel-shaped prolongation, which
may be traced cephalad into the Crus olfactorium, and to within

DEMONSTRATION OF THE PORTA. 457

about 2 mm. of the end of the Lobus. This canal is the reduced
representative of the rhinoccelia, which is quite large in most lower
vertebrates and in many mammals, but nearly or quite obliterated
inman. It is most easily traced by means of a beaded bristle. If
the bristle is gently moved to and fro, enough of the coloring matter
of the bead will adhere to the sides of the canal to make its recogni-
tion more easy as it is exposed, either by removing very thin slices
or by following it up with the tracer. The diameter of the canal is
about .5 mm., but it is usually expanded a little at its extremity.

§ 1151. Demonstration of the Porta.—Recall the position of the
aula upon the meson. Hold the brain in alcohol or water so that
only the surface cephalad of the dorso-ventral incision projects
above the surface; then blow toward the aula from between the
striatum and the mesal wall of the preecornu. The escape of bub-
bles of air will demonstrate the connection, through the porta, of
the aula with the proceelia; see Fig. 120 and Pl. IV, Fig. 16.

§ 1152. Haposure of the Precommissura.—Remove the cephalic
end of the brain by an incision at about the middle of the striatum,
and note, on the cut surface, the alternation of alba and cinerea on
account of which the name was applied. Remove other slices, cut-
ting a little obliquely, latero-cephalad, and note the increasing dis-
tinctness of an oblong white area, the oblique section of a jibrows
Fasciculus—the preecommissura—which unites the striata and Lobi
olfactorii across the meson, and which has been observed already in
the examination of the mesal surface; see also Pl. IV, Fig. 14.

Fig. 119.—Plaster casts of the medicornua, inverted.

Fig. 120.—Plaster casts of the diaccelia, aula, right porta, and part of the right pro-
celia of the sheep, inverted.

Fig. 121.—Diagram of a transection of the left medicornu.

Fig. 122.—Diagram of a transection of the diaccelia,

Fig. 123.—Diagram of a transection of the porta.

§ 1153. Fig. 119.—Plaster casts of the medicornua, inverted; x1.5. Compare with
Pl, IV, Fig. 15.

Objects.—To show (1) the shape and extreme curvature of these parts of the pro-
ceeliz, ; (2) that they are completely circumscribed, and do not open by a “fissure of
Bichat” upon the surface of the hemisphere.

Preparation.—The plaster was injected through the Foramen infundibuli while the
brain was supported by the calva (§ 1125). After resting undisturbed for an hour, the
brain substance was carefully torn and cut sufficiently to extricate the casts.

Explanation.—The ventral ends are thinner and somewhat expanded, excepting the
extremities, which are decidedly contracted. This contracted finger-like portion is wholly
enclosed by true nervous parietes; all the rest is bounded along the concave (cephalic)

458 ANATOMICAL TECHNOLOGY.

dorsal

Fie. 119.

froAlexus
= >
\ > seesulcus fe petons
cal =
tum are chnot der.
j “fre
7”
rs “etme reo
cain
1. Rte: alte
tola .
ee F sflenc al’s
i A ‘ 4
NEI ALS, vt callosa/i's
/ = J ‘
J Phy pa camp callosum
/ ’ / » 3 ¥- ~
Mmedicornu fF A or holon 4 -froeceiva.
Ave--- : Fee F OT NK
fmm~- ye Sicrir
Fre. 121. = dateta,
~=-d/aflextcs
—SlLpAanbenade
Gena
ert yaa oO
ddacde/t'a
3S om ==] meel-tommi'ss ura.
” : = Z32
Og. eee =
bee =e : tm ~)
ebeaes ||
Fes on { ’
FES =} deacéeSia
we ig Sacre ; < St,

Fig. 122.

‘ate .
dears 0 ot
LO Wee tee

Fie. 123.

Fig. 119-123.—Casts oF THE Catia AND DIAGRAMS INDICATING THE MANNER
OF THEIR CIRCUMSCRIPTION.

TRANSECTION OF THE MEDICORNU. 459.

border by the rima, where the continuity of the endyma reflected upon the proplexus, and
its adhesion along the fimbria and in the Sulcus limitans prevented the escape of the
injected material.

§ 1154. Fig. 120.—Plaster casts of the diaccelia (dorsal portion), aula, and right
porta and precornu of the sheep, inverted; x1.5. Compare with Fig. 113, 122; Pl. II,
Fig. 7,10; Pl. IV, Fig. 16, 18, 19.

Objects.—To show that (1) the porta permits the passage of injection mass from the
aula into the proccelia ; (2) the aula, porta and diacelia are completely circumscribed ;
(3) the porta is a passage of some length, and strongly compressed.

Preparation.—The plaster was injected through the Foramen infundibuli (§ 1125).
Notwithstanding all possible caution in disengaging the casts, a fracture occurred just
between the porta and the aula. In mounting, a slight interval was left between the
parts. The left porta and proccelia are not included in the figure. The ridge on the ven-
tral aspect of the cast of the diaccelia corresponds with the dorsal contour of the medicom-
missure. The cast of the precornu is quite thin, and its lateral aspect presents a sharp
longitudinal depression corresponding with the ridge upon the striatum (PI. IV, Fig. 16).

Qualification.—The three following figures (121-123) are dia-
grammatic representations of our present understanding of the
relations of the plexuses to the membranous parietes of the porta,
diaceelia and medicornu.

It is probable that microscopic sections will be needed in order to elucidate certain
points, especially the question whether the proplexus and portiplexus are formed by the
intrusion of the entire pia or only of vessels therefrom (§ 1081). We have thought best
to represent the former view provisionally.

Admitting that in respect to this detail we may be in error, we wish to insist upon the
more essential point, viz., that these cavities are really and completely circumscribed by the
continuity of the endyma reflected from the borders of the nervous parietes upon the
plexuses.

§ 1155. Fig. 121. —Diagram of a transection of the left medicornu, Compare with
Fig. 113, 119; Pl. Il, Fig. 11; Pl. IV, Fig. 14, 15; also with Duval (2, Pl. I, Fig. 2).

Object.—To show that the medicornu is completely circumscribed, although the proper
nervous parietes are absent from the porta to near its tip, constituting the rima.

Explanation.—The figure is based upon Fig. 113, but the cornu is disproportionally
enlarged, as are also the distances between the hemisphere and the mesencephalon and
diencephalon. The membranes and the proplexus are also introduced.

It should be remembered that this represents a transection of the length of the rneil:
cornu, although, from the fact that the plane of section is horizontal with respect to the.
brain as a whole, the cavity closely resembles a longitudinal exposure of the postcornu of
man and the monkeys, which does not exist in the cat.

The ectal surfaces of the hemisphere and of the epencephalon, mesencephalon, post-
geniculatum and pregeniculatum are covered by pia. The cornu is lined by endyma. |

In the frog and presumably in the embryo of the cat, the entire length of the medi-
cornu has complete nervous parietes, as has the tip of the cornu in the cat and man. The
endyma and the pia would then be wholly separated.

But the abrogation of the nervous continuity between the border of the fimbria and
the Sulcus limitans permits the vessels of the pia, or perhaps a fold of the pia itself, to

460 ANATOMICAL ‘TECHNOLOGY.

intrude apparently into the cornu. In so doing, however, the endyma is carried before
so as to encompass the fold or the vessels, as an abdominal viscus is surrounded by the
peritoneum. Hence, also, the cornu is really completely enclosed by the endyma, even
where the nervous parietes are absent.

The general name striatum is given to the thickened part of the hemisphere, but the
cauda striati and tenia are not represented,

§ 1156. Fig. 122.—Transection of the brain through the diacceelia. Compare with
Fig. 120; Pl. Ill, Fig. 7, 10,18; Pl. IV, Fig. 15.

Objects.—To show (1) that the diaccelia has a roof (diatela) independent of the velum
and fornix ; (2) that the dorsal surface of the thalamus is ectocelian ; (3) that the arach-
noidea does not reach the bottom of the interhemispheral fissure.

Explanation.—The diaccelia is seen to be divided into a larger ventral and a smaller
dorsal portion by the large medicommissura. The walls (lateral parietes) of both portions
are the thalami.

The dorsal surface of the thalamus is convex and covered by pia. The mesal is nearly
flat and covered by endyma. The rounded angle between these two surfaces presents a
ridge, the habena, and a furrow, the Sulcus habene.

The endyma leaves the thalamus along the sulcus (PI. III, Fig. 7), and is reflected first
dorsad and then mesad so as to roof in the diaccelia completely, as indicated in Pl. IL,
Fig 10, and by the definite form of the plaster cast shown in Fig. 120.

In the frog and in the embryo mammal, the only parts dorsad of the diaccelia are this
endyma and the pia and arachnoid which envelope the entire brain, together constituting
a membranous diatela, But in the adult mammal, the hemispheres not only project dor-
sad of the diencephalon, but unite along the meson so as to form the callosum and the
mesal part of the fornix (lyra) ; hence these parts are dorsad of the diatela, and the latter
is often ignored on account of its tenuity.

The relation of the diaplexus to the diatela is not altogether clear. In the figure only
one is represented. There is no evidence that it is formed by the intrusion of the pia
along the Sulcus haben, and more probably it is primarily prolonged from the aula,
as in Menobranchus, but acquires a somewhat distinct adhesion to the diatela.

§ 1157. Fig. 128.—Diagram of a transection of the porta (foramen of Monro). Com-
pare Fig. 113, 120, and Pl. III, Fig. 18, 19.

Object.—To show that the porta is completely circumscribed, notwithstanding the ab-
sence of the proper nervous parietes at the dorsal end where it adjoins the rima.

Description.—The plane of section is dorso-ventral and longitudinal, practically paral-
lel with the meson. Regarding the porta as a short passage with an approximately trans-
verse direction, it is here transected.

The larger mass is the dorso-cephalic portion of the thalamus. Cephalad and dorsad
of it is the fornix with its Columna, these being continuous with the corresponding half
of the septum lucidum.

The dorsal surface of the thalamus is convex and covered by pia (velum), but the
cephalic surface is concave and covered by endyma. In man and in some cats, the bound-
ary between the two surfaces is indicated by a more or less distinct tubercle. In all cases
there is a point of reflection of the endyma cephalad toward the fornix.

The corresponding surfaces of the fornix are likewise pial and endymal ; there is no
elevation of the surface to mark the boundary between the two, but nearly opposite the
point of reflection of the endyma from the thalamus it is reflected also from the fornix.

So much of the interval between the thalamus and the fornix as lies ventrad of these
two points of reflection is the porta. . Primitively, there is reason to believe, the endyma

EXPLANATION OF THE PLATES. 461

continued directly across, as the lining of the original nervous roof. The abrogation of
the nervous portion of that roof permitted the intrusion of the pia (or of its vessels) to
form the portiplexus, upon which the endyma is reflected.

The boundaries of the porta are, then, as follows: caudal, the thalamus ; cephalic, the
fornix ; ventral, the continuity of the two; dorsal, the endyma, reflected upon the porti-
plexus.

EXPLANATION OF THE PLATES.

§ 1158. The four lithographic plates of the brain illustrated the
senior author’s paper (74) in the Proceedings of the Philosophical
Society of Philadelphia, by courtesy of which they are included in
the present work. With slight alterations, the following explana-
tions are the same as given in that paper, but quotation marks are
used only where specially needed.

As with the other figures of the brain, all of the preparations from which the figures
were drawn are in the Museum of Cornell University, and are accessible for examination
to those who may desire to verify the figures or the descriptions.

In most cases, each figure is based upon more than one preparation. Encephalotomists
need not be reminded of the difficulty of obtaining a preparation which shows many points
of structure equally well. Since the present account is only general, and does not aim to
indicate individual peculiarities, or those of sex, breed or age, most of the figures may be
regarded as representing what may be called an average cat's brain. It is obvious that a
very large number of specimens would need to be carefully compared in order to confer ”
upon any generalization respecting sex, etc., a trustworthy character.

“ Most of the figures are twice the diameter of the preparations, and, with the excep-
tion of Fig. 1 and 2, it would have been better to make the enlargement four or five
diameters. Aside, however, from the greater expense which this would have involved,
such a degree of enlargement would have rendered it not only possible but necessary to
show certain details of structure upon which my information is, at present, imperfect.

** All of the figures have been drawn from my own preparations by Miss G. D. Clem-
ents, B. 8., at the time a student in the Natural History Course in Cornell University.

‘* Artists and anatomists who have undertaken to represent the details of encephalic
structure understand the difficulties of the task, and will admit that the omissions and
inaccuracies to which attention is called in the descriptions are both few and unimportant
compared with the general thoroughness of the work. Indeed, for all the deficiencies, I
hold myself much more responsible than the artist, by whom some of the figures were
drawn at least four times, twice upon stone.”

The abbreviations are explained in §$ 1127, 1128; synonyms, references and brief
descriptions are given in the latter part of this chapter (§§ 1181-1333).

PLATE I.

§ 1159. Fig. 1.—The dorsal aspect of the brain; x2.

“The general form and some of the fissures are drawn from Prep’s 288 and 289, the
bisected brain of a white and Maltese 2; but the fissures of the right hemisphere are
derived from several different preparations.

462 _ ANATOMICAL TECHNOLOGY.

“The Lobi olfactorii (Z. o/.) are made somewhat too prominent; there is considerable
difference among cats in this respect, although much less than among dogs.

“The general features of the cerebellum (cb/.) are well shown. The Lobi laterales
(Z. /.) have only a fair proportion to the median lobe or vermis (vm.), instead of the pre-
ponderance which they have in the human brain The lateral contortion which charac-
terizes the caudal aspect of the vermis in adult cats (as shown in my paper, 11, 221, Pl. I,
Fig. 1 and 2) does not affect the dorsal part.

“ As already stated, the fissures of the hemispheres are differently represented upon the
two sides. The combination of the two kinds of fissural arrangement in a single figure
serves to illustrate the extent of the lateral variation and compensation to which attention
was called by me in 1873 (11, 282).”

§ 1160. Fig. 2.— The sinistral aspect of the brain. From Prep. 288; x 2.
Compare with Fig. 124.

The Lobus olfactorius (Z. ol.) is made somewhat too prominent. The curved line
upon its lateral surface indicates, approximately, the boundary of the more cephalic por-
tion of the pero or ectal layer, whence arise the Nervi olfactorii. These nerves are not
shown.

The features of the Crus olfactorium indicated by /m. cin. and /m. ald. are more fully
shown upon Fig. 3.

The Nervus opticus (JV. op.) projects from the ventral margin of the figure, and the
Fissura Sylviana (F. S.) is seen dorso-caudad of it.

The ventral end of this fissure, as is always the case in the cat, joins the fissure which
forms the dorso-lateral boundary of the Tractus olfactorius (77. ol.), and the cephalic and
caudal divisions of that fissure are called respectively rhinalis and postrhinalis (FF. rh.
and prh.). So much of the hemisphere as lies caudad of the F. Sylviana forms the Lobus
temporalis (LZ. tmp.), the ventral extremity of which is the Lobulus hypocampz (LJ.
hmp.).

The cerebellum (cb/.) presents the narrow median lobe or vermis (vm.), and the Lobus
lateralis (I. l.). Near the ventro-cephalic angle of the latter, two or three of the lamine
of the second tier project as the Lobulus appendicularis (Z/. ap.), which is seen better in
Fig. 3.

The metaplexus shown in Fig. 3 (mtpz.) has been removed so as to expose the promi-
nent Eminentia auditoria (Hm. au.), whence springs the N. auditorius (WV. auw.).

Just ventrad of the eminence is the trapezium (¢z.), and cephalad of this is the
pons (p7n.).

Between the pons and the hemisphere appears a part of the Crus cerebri (Cr. cb.), and
cephalad of this is the slender N. trochlearis (JV. tr.), which, by inadvertence, seems to
emerge from the F. postrhinalis instead of from between the cerebellum and the hemi-
sphere.

The N. trigeminus (J. trg.) has been cut short, in order the more clearly to show that
it usually emerges just caudad of the pons, and not through it as in man.

The remaining nerve origins are indicated only by dots. Those of the NN, glosso-
pharyngeus, vagus and accessorius (JV. gph., v. and ac.) form a series. At the side of
the myelon, near the dorsal and ventral borders, are seen the origins of the first cervical
nerve (J. cv. 1).

In this figure the fissures are accurately represented as they are in the preparation,
excepting that the small F. lunata (¥. Zn.) has been added from Prep’s 519 and 520. The
small F. intermedia might well have been inserted between the dorsal ends of the FF.
anterior and postica (FF. a. and p.).

nope emer

EXPLANATION OF THE PLATES. 463

PLATE IL

§ 1161. Fig. 3.— The basis encephali, or ventral aspect of the brain; x 2.
Compare with Fig. 116.

The proportions and general features are from the brain of an adult ¢, Maltese and
white, Prep’s 288, 289. Some details of the Area prechiasmatica (the region cephalad
of the chiasma) are from 461 and 527 ; of the Ar. postpontilis (the region caudad of the
pons) from 358, 454 and 491 ; and of the intermediate Ar. cruralis from 422, 506 and 527.

Most of the nerves and cerebral fissures are lettered on the right side, and most of the
other parts on the left. Some of the left nerves are cut short, and the left N. trochlearis
is not shown at all.

The Lobi olfactorii (Z/.-o/.) are made too long, and the hypophysis (Aph.) is too short.

Attention is called to the following points, chiefly in comparison with the human
brain :—

The absence of a distinct Radix intermedia (Rz. in.) of the Crus olfactorium, corre-
sponding with the so called “ middle root of the olfactory nerve” in man. The part so
designated upon the plate is apparently only an area, comparatively undifferentiated,
between the more or less fibrous tracts forming the Radix mesalis and Rx. lateralis.

The turning of the Rx. mesalis (Az. ms.), (‘internal root”), over the margin of the
brain so as to appear upon the meson.

The distinction of the Rx. lateralis (Fz. 1.), (“ external root ”), into a lateral gray and a
mesal white tract, the Limes cinerea (Zm. cin.) and the Lm. alba.

The great extent of the (Locus) preperforatus ( prpf.), and its division into a cephalic
more prominent portion (Pt. p.) and a caudal depressed portion (Pt. d.). Both portions
are “ perforated,” but the degree of furrowing of the Pt. prominens varies considerably.
These furrows exist in some other Carnivora.

The width of the hypophysis (Aph.) and the crenation of its caudal border, indicating
the existence of an ental subspherical mass, which is covered by an ectal layer, the thin-
ness of which, in the caudal region, permits the contour of the former to be seen.

The slight degree of separation of the albicantia (abn.), which are here nearly con-
cealed by the hypophysis, but more fully shown in Fig. 12.

The distinctness of the cimbia (emb.), which is better seen in Fig. 11.

The slight extent of the true postperforatus (ppf.); the only part which is really
‘* perforated ” is a small area just caudad of the albicantia, and partly hidden by them.

The less caudo-cephalic extension of the pons (pz.); this exposes more of the Area
intercruralis (Ar. ic.) than in man, and uncovers the trapezium (¢z.), which, in man, is
wholly concealed. Connected also with this feature of the pons is the fact that the N.
abducens (WV. abd.) passes directly cephalad from its origin a little caudad of the pons,
whereas in man it is forced to curve around the caudal border. Finally, the N. trigemi-
nus (WV. trg.), instead of emerging through the pons near the cephalic border as in man,
emerges close to its caudal border or clears it completely ; see Chap. XI.

The greater extent of the Ar. cruralis, which may be ascribed both to the less extent
of the pons and the less degree of flexure of the whole brain at the mesencephalic region.

The greater width of the Tractus postrhinalis (Jr. prh.), which includes the surface
of the Lobulus hypocampz (Zl. hmp.). In man, indeed, this part is hardly visible on
account of the prominence of the convolutions laterad of the F. postrhinalis.

The apparent origin of the WV. oculomotorius (N. ocm.) laterad of the meson and just
caudad of the cimbia (cmb.). ;

464 ANATOMICAL TECHNOLOGY.

The appearance of a division of the ectal layers of the pontile fibers into three groups,
cephalic, caudal and intermediate, the latter partly overlapped by the other two.

The appearance of a faint band crossing the trapezium a little obliquely between the
origins of the NN. abducens (JV. abd.) and facialis (V. f.). The distinctness of this band
varies.

The origin of the N. hypoglossus (J. fg.) at the lateral border of the Area elliptica
(Ar. el.), which is thought by some (Am. Jour. of Neurology, etc., I, 102) to be the surface
of the oliva or “olivary body” of man, The determination of this point involves some
comparisons and sections which we have not yet made.

The close association of the roots of the WV. glossopharyngeus (N. gph.), vagus (N. v.)
and accessorius (N. ac.). See Stowell (Z) and Chap. XI.

The marked prominence of the ventro-lateral region of the metencephalic continuation
of the Columna lateralis myelonis (Clm. l.), forming an elevation to which I have applied
the provisional name Area ovalis (Ar. ov,), but which is thought by some (Am. Jour. of
Neurology, etc., I, 102) to represent the Tuberculum Rolandii.

The absence of any superficial decussation of the pyramides(py.). Hence,the F. ventri-
mesalis (F. vms.), or ‘‘ anterior fissure,” is uninterrupted. The /. ventrilateralis (F. vl.) is
defiected at the caudal end of the Area elliptica.

§ 1162. Fig. 4.—The mesal surface of the right hemiencephalon; x2. Compare
Fig. 114.

The general features are from the same brain as Fig. 3, but some are derived from
Prep’s 290, 304 and 454.
The surfaces shown in this figure are of four kinds, as follows (§ 1137) :—

(1) The natural surfaces which are covered by pia. These are the mesal aspects of the
hemisphere (hem.) and the Lobus olfactorius (L. ol.).

(2) The natural mesal surface (Ar. spt.) of the right half of the septum lucidum, which,
in the cat, is in contact with its platetrope, or separated therefrom only by a thin layer of
connective tissue. We have never observed an interval corresponding to the pseudo-
celia or “ fifth ventricle ” of man.

(3) The natural endymal surfaces of the true celia or “ ventricles.” Of course the pro-
coeliz (“lateral ventricles ”) do not appear.

(4) The cut surfaces of the commissures and other parts which cross the meson or lie
upon it. In the cerebellum (cbi.), the relative areas of the ental alba and the ectal cinerea,
forming the arbor vite (arb.), are indicated by the shading ; with less definiteness, the alba
is shown in the callosum (cl.), the fornix (f.), the precommissura (pres.), the postcommis-
sura (pes.), the commissura habenarum (cs. h.), and the chiasma (ch.). The section of the
medicommissura (mes.) should appear as if composed, at least chiefly, of cinerea, but no
attempt has been made to indicate the nature of the cut surfaces of the Crista fornicis
(Crs. f.), the terma (t.), the hypophysis (hph.), the infundibulum (inf.), the conarium (en.),
the optict and postoptici (op. and pop.), the valvoula (vv.), the Crura cerebri (Cr. eb.), the
metatela (mittl.), or the rest of the epencephalon and metencephalon (mten.). The ex-
tent of the transverse fibers of the pons (pn.) should have been represented, at least
approximately.

So much of the cephalic boundary of the awla (a.) as intervenes between the precom-
missura ( pres.) and the crista (Crs. f.) is very thin, and is too indistinctly shown in the
figure. Neither here nor at any other point is there any such interruption of the wall as
would form a communication between the true celie and the pseudoceelia or the ectal
surface of the brain. It is probable that the presence of such a communication as is

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ascribed to the human embryo and to some animals in Quain (A, II, 548) is due to the
artificial rupture of the natural connections ; see p, 586 of the same work.

Attention is called to the following points, chiefly in comparison with the human
brain :—

The appearance of the Rx. mesalis (#z. ms.) on the meson, and the presence of two
shallow fissures, postradicalis and preradicalis (/'F. prd. and prrd.) between it and the
adjoining surfaces of the hemisphere.

The large size of the commissures, especially the medicommissura, which nearly fills
the dorsal part of the diaceelia (dc.).

The non-appearance of the porta when the meson is viewed squarely ; it is doubtful
whether the human “ foramen of Monro ” is really visible from the meson.

The less extent of the callosum, especially of its rostrum (rm.). In some human
brains the rostrum does not extend so far as is usually represented.

The darker spot on the section of the hypophysis represents the space occupied by the
ental mass, which has been removed.

The relations of the pia are not indicated at all, and are not well understood, especially
between the cerebellum and the metencephalon and mesencephalon.

PLATE III.

With the exception of Fig. 13, all the figures upon this plate represent the natural
surfaces of regions which are more or less completely concealed by other parts in the
undissected brain.

§ 1163. Fig. 5.— The cephalic aspect of the prosencephalon. From Prep.
294; x2.

The hardened brain was transected at the /. postica, so that the preparation includes
only the cephalic two thirds of the prosencephalon,

The drawing represents the preparation tilted up so as to expose the ventral aspect
foreshortened.

As compared with Fig. 6, this might well have been made of the natural size. A less
regularly symmetrical brain would have been more instructive. One of the Crura olfac-
toria should have been divided at a little greater distance from the prosencephalon.

So far as appears in the figure, the fissures are remarkably alike upon the two sides ;
the left F, ansata (7. an.), however, only the meso-cephalic end of which appears in the
figure, presents the somewhat unusual but very suggestive condition of entire independ-
ence of the lateralis (which is invisible) and the coronalis (7. cor.). On the right side it
is joined by the former fissure.

The right F. Sylviana (7. S.) is shorter than the left, and presents a slight terminal
bifurcation which is not shown.

In consequence of the removal of the Lob olfactorii and the tilting of the whole prepa-
ration, so much of the F. rhinalis (/ rh.) as lies cephalad of its union with the super-
orbitalis (7. so.) is practically obliterated, and the remainder of it is so foreshortened as to
appear as an insignificant intermediate portion of an extensive u-shaped fissure formed by
the FF. Sylviana (7 8.) and superorbitalis (F. so.). ‘The appearances thus presented
are suggestive in view of the idea of Meynert (7, 12), which I also entertained at one time
(11, 225), that the F. superorbitalis represents the ‘anterior branch’ of the human
F. Sylviana, and that the intervening region corresponds to the ‘ operculum.’”

A slight preponderance of the left hemisphere just caudad of the F. Sylviana is some-

30

466 ANATOMICAL TECHNOLOGY.

what exaggerated in the figure, and the Crura olfactoria (Cr. ol.) should differ less in form
and in their distance from the meson.

The FF, olfactoria (F. ol.) appear as little more than shallow furrows.

On account of the foreshortening of the ventral aspect, the line of separation of ul
Portio prominens (Pt. p.) and the Pt. depressa (Pt. d.) is indistinct. The hypocampal
lobule (J. hmp.) on each side has been flattened by pressure, and is so represented.

§ 1164. Fig. 6.—The caudal aspect of the prosencephalon, with part of the dien-
cephalon. From Prep. 292, an adult ¢; x1.

The diencephalon has been transected so as to leave a concave surface which, at the
meson, is close to the caudal border of the medicommissura (mes.), but rises at the sides so
as to coincide nearly with the caudal surface of the prosencephalon.

The postcommissura has been removed, and the slender transverse band (Qs. h.) just
ventrad of the splenium (sp.)is the Commissura habenarum. Had the postcommis-
sura been left, the intervening space would be a foramen, Fm. conarit.

The shallow depression of the ventricaudal surface of each hemisphere just laterad of
the splenium represents the area of contact of the opticus.

The cerebra! fissures are markedly unsymmetrical, and thus in contrast with those of
Fig. 5. The right postrhinalis (7. prh.) is the longer, and the right postsylviana (F. ps.)
joins the supersylviana, although the place of union does not appear in the figure. On
the contrary, by reason of the perspective, it seems to be joined by the F. medilateralis
(F. mi.).

The hypocampal lobules a. hypocampe) have their proper rounded form in this

preparation.
« Part of the diaccelia (dc.) appears dorsad of the medicommissura, and part on its ven-
tral side (Fig. 122). In man, the commissure is smaller and the celia correspondingly
more extensive. On account of the removal of the hypophysis and infundibulum, the dia-
celia opens freely at the Fm. infundibuli (7m. in/.).

§ 1165. Fig. 7.—The dorsal aspect of the diencephalon and mesencephalon.
From Prep’s 397 and 494, adult ¢ , 423, a nearly adult ¢, and 506; x2.

The principal features of this figure were drawn from Prep. 506. The preparation was
made by lifting the caudal ends of the hemispheres and gradually separating them, with
the callosum, fornix and velum, from the subjacent parts. The epencgphalon and meten-
cephalon were then removed by a transection just caudad of the postoptici.

The valvula (vv.) is drawn as it appeared in Prep 494, after inflation by blowing air
from the diaccelia through the mesoccelia or iter.

The Commissura habenarum (Cs. h.) is really more distinct in Prep. 397 than appears
in the figure. The habenz (h.), their sulci (S/. #.) and the lines of reflection of the
endyma are taken from Prep. 422, and their distinctness is not exaggerated in the figure ;
see Fig. 122.

The complete roof of the diaceelia, the diatela (dtl.), is shown in Fig. 10.

As compared with the homologous parts in man, the feline postoptici ( pop.) and geni-
culata (pgn. and prgn.) are larger, while the thalami proper (th.) seem to be only the
mesal continuations of the pregeniculata (prgn.), and to lack altogether the pulvinar or
“posterior tubercle ” of man.

§ 1166. Fig. 8.—The caudal aspect of the mesencephalon, with parts of the
adjoining regions. From Prep. 506; x1.

The plane of transection coincides nearly with the caudal surface of the postoptici
(pop), and has divided the pons ( pn.) a little caudad of its middle. The valowla (vv.) was

EXPLANATION OF THE PLATES. : 46%

torn from this preparation, and the line of its attachment is not distinctly shown. Some-
thing of its position may be judged from Fig. 7. The caudal orifice of the mesocelia
(mse.) is shown here as a nearly regular circular spot; in reality, it presents a slight mesal
extension at both the dorsal and ventral sides. Indeed, when carefully examined, the so
called ‘‘ aqueductus Sylvii” is far from being a perfectly simple and uniform tube ; its
form in man is indicated in Reichert’s Fig. 31 (A, Taf. 4). Among the lower mammals it
is usually larger, and with the lower vertebrates it often has the proportions of a true
ccelia, with lateral extensions.

The cimbia (emb.) is partly seen on the right. The geniculata (pgn. and prgn.) do not
project as far as they should. The optici are wholly hidden from view by the prominent

postoptici (pop.).

§ 1167. Fig. 9.—The sinistral aspect of the mesencephalon and diencephalon.
From Prep’s 491 and 506; x2. :

The only cut surface shown in this figure is that caused by the oblique transection
between the diencephalon and the prosencephalon; the plane of section followed the
cephalic border of the Tractus opticus (7’r. op.), and corresponds with the Suleus limitans
between the thalamus and the striatum.

Crossing the crus (Cr.cb.), just caudad of the postgeniculatum (pgzn.), is seen the
cimbia (emb.).

“ Upon this figure should appear the Lemniscus superior and L. inferior, and the post-
brachium and prebrachium, provided they exist in the cat as distinct parts visible at the
surface. I have not been able to satisfy myself respecting their exact position and limits
in the human brain, and refrain from expressing any opinion concerning them.”

§ 1168, Fig. 10.—The dorsal aspect of the diencephalon, including the diatela.
From Prep. 301, a half grown $; x1.

The object of this figure is to show the existence of a distinct roof of the diacelia inde-
pendent of the fornix and velum, which have been removed. This diatela (dé/.) presents
the appearance of something more than the lining endyma, but its structure has not,
so far as we know, been examined, The darker triangular area at the cephalic end of
the diatela corresponds with the delta fornicis (dlt. f.).

§ 1169. Fig. 11.—The Area cruralis, with part of the pons and of the Ar. prechi-
asmatica. From Prep’s 506, 425 (nearly adult 2) and 461 (2); 1.5.

This figure, reversed, is reproduced in outline in Fig. 118. The general relations of the
medicornu are also indicated in Fig. 113, and the relations of the cornu, rima and pro-
plexus in Fig. 121.

The Lobi temporales have been divided at different levels on the two sides. From
the right, only the extremity, or L/. hypocampe, has been removed, and the section of the
medicornu (mcu.), which is here cut very obliquely, is a slightly curved space completely
circumscribed by a nervous wall. Neither in the cat, nor—contrary to the common belief
and the explicit statement in Quain (A, II, 542, 544)—in man, doves the rima or “ great
transverse fissure ” extend to the tip of the medicornu.

Where the L/. hypocampe rests against the Tractus opticus (77. op.), there is usually
a deep notch which may be called the Incisura hypocampz2 (Inc. hmp.).

On the left side, the hemisphere was dissected off so as to leave two cut surfaces. One
of these surfaces is plane and nearly horizontal, and lies at about the level of the dorsal
end of the postgeniculatum (pgn.). The other is convex, and extends from the cephalic
border of the former obliquely to the ventral surface of the brain ; it corresponds closely
with the cephalic border of the Tractus opticus.

468 ANATOMICAL TECHNOLOGY.

The left medicornu is cut at about the middle, and at nearly a right angle with its
course ; hence its lumen presents its characteristic crescentic section, the ental boundary
being the convex surface of the hypocampa (Amp.).

The cephalic margin of the medicornu is here seen to reach the surface of the hemi-
sphere close to the Tractus opticus, and this narrow line of interruption of the true ner-
vous wall of the cornu constitutes the rima. The scale upon which this figure was drawn
did not permit the relations of the pia, the velwm and the preplexus to be shown, and the
undulations of the ectal surface, corresponding with the FF. hypocampe and fimbria, and
the fasciola and fimbria are hidden by the projecting postgeniculatum.

Most of the cephalic portion of the brain has been removed, but the Portio depressa
' (Pt. d.) of the preperforatus is seen, with part of the Pt. prominens (Pt. p.). The
removal of most of the chiasma (ch.) exposes the form and extent of the Recessus opticus
(R. op.).

The pons has been transected obliquely, and its caudal portion removed, together with
the rest of the epen. and the metencephalon.

The left crus (Cr. cb.) is seen in its whole length, excepting a small part concealed by
the slightly projecting cephalic border of the pons. The well marked cimbia (emb.) may
perhaps be regarded as the boundary between the diencephalic portion of the crus (Pt.
dien.) and the mesencephalic portion (Pt. msen.), which more directly supports the optici
and postoptici; in man, this part seems to be more nearly concealed by the pons.

The right N. oculomotorius (J. ocm.) is seen to emerge from the crus just caudad of
the mesal end of the cimbia and just laterad of the Sulcus intercruralis lateralis (SI.
ic. 1.). A marked longitudinal ridge of the crural fibers separates from the postgenicu-
latum (pgn.) a depressed area, the quadrans (¢.).

The albicantia (abn.) are more closely united than in man, but large, white and per-
fectly distinguishable. The shallow furrow between them, together with the u-shaped
furrow which forms their cephalic boundary, is the Sulcus triradiatus (SV. trd.).

The hypophysis has been removed so as to expose the Tuber cinereum (7. cén.) and
the thin raised margin of the Fm. infundibuli (#’m. inf.).

Just caudad of the albicantia, and partly overhung by them, is a small triangular
depressed space with distinct perforations ; this seems to be the true postperforatus
(ppf-)-

The entire Area intercruralis may be more completely exposed by removing the cere-
bellum and dorsiducting the “medulla,” as in Prep. 425.

§ 1170. Fig. 12.—The dorsal aspect of the metencephalon. From Prep. 397
(adult 9), 464 and 491; x1.

“The metatela, like the diatela, seems to consist of more substantial tissue than sim-
ply pia and-endyma, but I am not aware that its microscopic structure has been ascer-
tained. I am in doubt respecting the precise limits and attachments of the metatela
and metaplexuses.” No “ foramen of Magendie ” was seen.

§ 1171. Fig. 13.—Part of an oblique transection of the prosencephalon and dien-
cephalon to show the form and position of the Crista. From Prep. 441; x2.

The brain was transected obliquely at an angle of about 45 degrees with the general
longitudinal axis. The plane of section passed from a point nearly dorsad of the genu,
through the aula, the medicornu and the albicantia. The figure includes only a part of
the caudal aspect of the slice.

The dorsal borders of the honlonhoiwe are divaricated slightly, and the callosum (cl.)
is seen crossing the interval ; the slight notch on each side just dorsad of the callosum is
the F. callosalis (7. ci.),

EXPLANATION OF THE PLATES. 469

The striata (s, s.) are seen in section just ventrad of the lateral expansion of the callo-
sum, while the lower part of the figure is occupied by the thalami (th.), united by the
medicommissura (mces.). Between each thalamus and the corresponding striatum is a
groove, the Sulcus limitans (SV. 2.).

The Columnz fornicis (Clm. f.) are divided nearly at a right angle with their course,
and at a point just dorsad of the crista (Crs. f.), which is particularly well shown in this
preparation. The open space between the fornix and the thalami is the aula (a.), and at
the sides are the portz (p.) leading into the procwlia. All the membranes and plexuses
have been removed.

/

PLATE IV.

Unlike those of Plate III, all of the figures upon this plate represent cut surfaces,
although some natural surfaces are shown also.

§ 1172. Fig. 14.—A ventro-caudal view of the fornix, with the adjacent parts.
From Prep’s 507, 433 and 396 (adult 4); x2.

The preparations were made while the brain was fresh, so as to permit more flattening
of the hemispheres, and consequent exposure of the fornix.

After the removal of the rhinen-, meten-, epen- and mesencephalon, the thalami and
geniculata were excavated piecemeal, so as not to injure or displace the fornix. The cut
surface (s.) at each side of the fornix (f.) is the plane of division of the diencephalon from
the striatum.

The cephalic end of the prosencephalon was then sliced down to the level of the pre-
commissura (pres.), which is seen to send a distinct fasciculus toward the L. o/fuctorius on
each side. Then the right hemisphere was sliced obliquely from near the meson dorso-
laterad so as to cut the medicornu (mcw.) and hypocampa (Amp.) at about the middle of
their length. On the left side, the L. temporalis was allowed to fall somewhat by its
own weight so as to expose the fornix more fully.

The velum and allthe plexuses were removed so as to display the peculiar markings of
the fornix and its mesal area, which is supposed to represent the lyra (/y.).

The porte (p.) appear both shorter and narrower than they really are, on account of
the obliquity of their planes to the line of vision. The v-shaped line called ripa (rp.),
which connects the two porte, separates the delta (d/t.) or entoccelian part of the fornix
from the remaining surface, which is wholly outside of the coelian cavity. The delta
forms the roof of the aula, the cephalic continuation of the diaccelia between the two
porte, and the ripa is the line of reflection of the endyma upon the two auliplexuses ; the
removal of these plexuses causes the rupture of the endyma along the ripa.

At each side, the ripa curves dorsad somewhat sharply so as to reach the dorsal end of
the porta; at this point, and dorso-caudad for the entire length of the rima (r.), the
endyma is simply reflected from the contiguous surfaces of the fimbria (fmb.) and the cor-
responding border of the striatum. Hence the rima is virtually closed, and thus wholly
distinct from the porta.

On the meson, between the porte, is seen the crista (Crs. f.), which is unusually
rounded in this preparation. The carina, which sometimes appears as a slight mesal ridge
extending dorso-caudad from the crista, does not appear in this preparation. The Reces-
sus aul (BR. a.) is the cleft between the two Columne fornicis (Cm. f.) whose cut ends
are seen just caudad of the precommissura. The shading on the caudal aspect of the
columne indicates, but rather too distinctly, a slightly depressed area, of which the dorsal
part, close to the crista, sometimes presents the appearance of a transverse band, for which
the senior author has suggested the name Commissura fornicis (Cs. f.).

470 ANATOMICAL TECHNOLOGY.

“ After a prolonged examination of many preparations, I am unable to define accurately
the limits of the fornix proper and the lyra (/y.). A comparison of the accounts given in
standard works with the appearances presented by the limited materials at my disposal
leads me to doubt whether the relative extent of the two parts in the human brain is
well determined.”

The fasciola (fscl.) is thick, and no part of it presents the denticulations from which
its more ventral portion, in man, is called ‘‘ fascia dentata.” The peculiar curve of the
hypocampa, medicornu and fasciola is well indicated by the fact that the F. hypocampze
(F. hmp.), which corresponds nearly with them in direction, is visible in this preparation
only at its two ends, near the splenium (sp.), and near the tip of the Ll. hypocampz (Zi.
hmp.). Between the fimbria and the fasciola is a depressed line which may be called the
Fissura fimbrie (7. fmb.).

§ 1173. Fig. 15.—The dorsal aspect of the procelia. From Prep. 465; x1.

The special object of this preparation is to show that, in the cat, no part of the thalamus
appears in the prucelia. The cerebellum (cb/.) is shown only in outline.

Both hemispheres were sliced from the dorsum to the level of the intermediate part of
the callosum (¢/.). This laid open both proccelize in some degree. The central part of
each proceelia is called cella media (cel. m.). The right medicornu was then opened to
the tip, which, however, cannot be seen from the dorsal side.

The floor of the proccelia is seen to be formed by the striatum (s.), the fornix (f.) and
the hypocampa (Amp.). The proplexuses have been turned in opposite directions for the
sake of showing the absence of any interval between the fornix and hypocampa—or the
fimbria which forms the border of the latter—and the striatum, such as would permit the
appearance of the thalamus in the proceelia. See Fig. 121.

§ 1174. Fig. 16.—The rhinoceelia and procelia. From Prep’s 425 and 493; x2.

This figure shows the continuity of the procelia with the rhinocelia and its communica-
tion through the porta with the aula and diacelia, . See § 1151. '

The right half of the brain was transected through the caudal part of the medicommis-
sura (mcs.). A slice was then cut from the mesal aspect so as to include the genu. This
exposed the przcornu (prcu.) with the mesal aspect of the striatum (s.), the rhinocelia
(rhe.), and the relative extent of the pes (ps.), and the pero ( po.) of the Lobus olfacto-
rius. A bristle was then passed through the porta from the precornu into the aula (a.).
Just ventrad of the bristle are the precommissura (prcs.) and the terma (f.). The latter
is traced distinctly to the chiasma (ch.), so that the cephalic wall of the ccelian cavity is
complete. The deeper shadow just dorsad of the chiasma indicates the position of the
Recessus opticus (R. op.).

Just dorsad of the bristle, the crista (Crs. f.) is seen divided upon the meson, and con-
tinuous with the Columna fornicis (Clm. f.). The indentation between the crista and the
precommissura corresponds with the Recessus aulz (R. a.). The triangular Area sep-
talis (Ar. spt.), between the fornix and the callosum, is the mesal surface of the right half
of the Septum lucidum (Spt. lu.) and is in contact with its platetrope in the undissected
brain. The thickness of the hemisepta in the cat renders the adjective /wcidum wholly
inapplicable.

$ 1175. Fig. 17.—The mesal aspect of the right hemisphere, with the Lobus
olfactorius. From Prep’s 296 and 401; x1.

The caudal divisions of a hemiencephalon were removed, and the thalamus carefully
excavated so as to leave undisturbed the fornix (f.) and the fimbria (fmd.). In this
respect, this figure may be compared with the left half of Fig. 14.

SYNONYMS AND REFERENCES. 471

The special object of this figure is to show the hypocampal fissure (/. Amp.) in its
whole length at once. So great is the curvature of the parts that this is possible only in
a single position of the preparation in which the meson is foreshortened. In general, this
figure may be compared with those given by Flower (13) of the rabbit and sheep.

The dorsal end of the /. hypocampz ‘s seen to turn sharply around the splenium (sp.),
80 as to become continuous with the callosalis (/. el.). The fasciola (fsel.) is wide and
devoid of denticulatious, but is crossed obliquely by a shallow furrow. In this position of
the preparation, the F. fimbriz (/ fib.) appears to be continuous with a short line pass-
ing cephalad to a point ventrad cf the callosum ; in reality, however, this latter line is
only one of the markings of the ventral surface of the fornix, and the F. fimbrie, like the
edllosatis, turns sharply dorso-caudad to terminate just cephalad of the splenium (Fig. 125),

§ 1176. Fig. 18.—The right procelia seen from the right or ectal side. From
Prep, 495; x1.

The right half of the brain was removed in successive slices until what remained was
about 3 mm. thick. The remainder of the striatum was then everted from the precornu
(preu.). The proplexus (prpz.) is slightly displaced, but the porta is hidden by the
portiplexus (ppz.). The medicornu (meu.) and the hypocampa (/mp.) are shown in sec-
tion, and the other parts will be readily recognized. The relative heights of the opticus
(op.) and the postopticus (pop.), at a little distance from the meson, are well displayed.
The short curved line at the cephalo-ventral end of the proccelia represents the beginning
of the passage to the rhinoccelia (Fig. 16).

§ 1177. Fig. 19.—The left precornu and porta exposed from the left or ectal side.
From Prep. 495; x1.

This figure represents the other side of the same brain from which Fig. 18 was drawn.
The preparation was made in the same way, but in addition the proplexus and porti-
plexus were carefully snipped off so as to expose the porta.

The porta (p.) is seen to open between the Columna fornicis (C7m. f.) and the cephalic
end of the thalamus (¢#.). The orifice would appear larger if the preparation had been
so placed as to leave its plane parallel with the picture-plane.

The membranes could not be shown well on so small a scale (see Fig. 123). In this:
and in the previous figure, the fornix is seen to be continuous with the hemiseptum (Spt.
Zu.) which forms part of the mesal wall of the pracornu.

§ 1178. Fig. 20.—Transection of the fornix with the crista. From Prep. 508; x1.
The object of this figure is to show the decided elevation formed by the crista (Crs. f.).
Only enough of the rest of the section is included to locate the crista.

. § 1179. Other Figures of the Cat’s Brain.—Since most published figures of the cat’s
brain illustrate the fissures rather than the structure, they will be mentioned in connec-
tion with Fig. 124, 125, later in this chapter.

SYNONYMS AND REFERENCES.

§ 1180. The principal parts of the Amphibian brain are enume-
rated in § 1058 and tabulated according to their segments in § 1069.
Most of the parts of the Mammalian brain which are visible to
the unaided eye are named in § 1128 in the alphabetical order of
their abbreviations, and in § 1138 they are tabulated according to

472 ; ANATOMICAL TECHNOLOGY.

their segments. Synonyms of about twenty of the principal parts
are given in §§ 1058, 1059.

In the following pages (§§ 1181-1333) the parts of the mammalian
brain are enumerated in the alphabetical order of the technical
names herein employed. Unless otherwise mentioned, these names
are the same as adopted by the senior author (9, 14); the ap-
parently new terms really differ but little from those in common
use (§ 1129).

Following the abbreviation of each name are references to figures
and sections in the present work and to the works on Human Anat-
omy by Gray and Quain. The principal technical and English
vernacular synonyms are then given, with in most cases a brief
description or commentary upon the part itself or its designation.

As has been stated already, our information is far from satisfac-
tory, and all parts of the cat’s brain need monographic treatment.

§ 1181. Alba, (Substantia), a/b.—§§ 995, 1047; Fig. 112, 116; Pl. I, Fig. 13; Pl. Iv,
Fig. 14. Gray, A, 60; Quain, A, II, 553.

Syn.—Substantia alba, white matter, white or fibrous nervous tissue.

The alba constitutes the columns of the myelon, most of the ental portions of the cere-
brum and cerebellum, and so much of the entire brain as is not formed by the cinerea,
which see, § 1204.

§ 1182. Albicans, (Corpus), abn.—Fig. 115, 116; Pl. I, Fig. 3, 4; Pl. IU, Fig. 11;
§1161. Gray, A, 621; Quain, A, II, 535.

Syn.—Corpus candicans, corpus mammillare, bulbus fornicis.

The albicantia are a pair of white elevations a little cephalad of the pons and overhang
ing the postperforatus. They are distinct, but sie so thanin man. For their relation
to the Columne fornicis, see § 1207.

§ 1183. Arachnoidea, (Membrana), arch.—Fig 112, H ; § 1077. Gray, A, 608 ; Quain,
A, I, 519 ; Westbrook, 7, 348.

Syn.—Arachnoideus, meninx media, tunica serosa.

Like the pia, this membrane needs thorough examination in the cat.

§ 1184. Arbor vite, arb. vt —Fig. 88, 117; Pl. II, Fig. 4. Gray, A, 684; Quain, e
Il, 519.

The ectal foliation of the cerebellum gives to the surface of a dorso-ventral section a
tree-like appearance, to which the above name is applied.

§ 1185. Aula (az.), a.—Fig. 110-112; Pl. II, Fig. 4; Pl. III, Fig. 18; Pl. IV, Fig. 16;
§§ 1065, 1145. Meynert (Stricker, A, Fig. 253); Balfour, A, II, Fig. 257.

Syn.—‘ Le vestibule des ventricules latéraux ”—Milne-Edwards, A, XI, 305.

Cavity of the prosencephalon primitivum—Mihalkovics, A, 30.

Cavity of the “‘ secundiires vorderhirnbliischen ”—Mihalkovies, A, Pl. 1, Fig. 1.

Cavity of the ‘‘ unpaaren grosshirnblase ”—Léwe, A, 93, Fig. 11, 12, “ es.”

Mesal portion of the cavity of the “ lobus communis ”—Huxley, 7, 00.

Mesal portion of ‘‘ Foramen commune anterius ”—Todd, A, 676; Quain, A, II, 544,
and other writers, according to Bell, B, Pl. X.

“Iter ad tertium ventriculum ”—Monro, A, 9.

SYNONYMS AND REFERENCES. 473

‘* Rima ad infundibuli, s. vulva”—Various authors, according to Dunglison, A, 906.
Mesal portion of the foramen of Monro—Balfour, A, II, 257.

Mesal portion of the ‘‘ ventriculus communis ”—Stieda, 6, 180.

Mesal portion of the “ common ventricular cavity ”—Spitzka, 6, 31.

The aula is the most cephalic part of what is commonly known as the third ventricle.
Its best defined portion lies between the two porte, and is bounded cephalad by the fornix
and caudad by the medicommissura. Ventrad it reaches the chiasma so as to include the
Recessus optici; dorsad it is bounded by the triangular area of the fornix, called delta.
The form of the cavity is therefore peculiar and irregular.

The Name.—The origin of the name and the reasons for its use are briefly stated in
§ 1065. Much remains to be done, especiaily in Comparative Anatomy and Embryology,
before the limits of this cavity can be well defined.

§ 1186. Auliplexus, apx.—Fig. 113; § 1066.

The aulic portion of the “ plexus choroideus ventriculi tertii” or diaplexus.

This portion of the plexus is so slight that it would hardly need a separate designation
but for the possibility that in the cat, as in Menobranchus, the larger diaplexus may be
only an extension of the more primitive auliplexus. .

§ 1187. Area cruralis (az.), Ar. er—Fig. 116, 118; Pl. I, Fig. 3; Pl. Ill, Fig. 11.

A convenient name for the ill-defined and non-homogeneous area of the basis encephali
bounded by lines projected laterad from the pons and chiasma. See Area intercruralis
(§ 1189).

§ 1188. Area elliptica, Ar. el—Fig. 116; Pl. I, Fig. 3; § 1140.

According to the Am. Jour. of Neurology, etc. (I, 102), this is the surface of the oliva,
notwithstanding the funiculi of the WV. hypoglossus emerge laterad of it instead of mesad
as in man.

§ 1189. Area intercruralis (az.), Ar. ier—Fig. 116, 118; Pl. Il, Fig. 3; Pi. III, Fig.
11; § 1138.

Syn.—Interpeduncular space ; Area intercruralis (manuscript)—Spitzka, 7, 165.

If the diverging fibrous tracts sometimes called peduneuli cerebri are to be called crura,
then the space bounded by them and by the pons and chiasma, should be intercrural
rather than interpeduncular.

* § 1190. Area ovalis, Ar. ov.—Fig. 116; Pl. I, Fig. 3; § 1140.

The surface of an elevation of the ventro-lateral aspect of the metencephalon, laterad
of the Area elliptica.

According to the Am. Jour. of Neurology, etc. (I, 102), this corresponds with the Tuber-
cle of Rolando, “ twbercolo cinereo.”

§ 1191. Area postpontilis (az.), Ar. ppn.—Fig. 116; Pl. Il, Fig. 3; § 1138.

The ventral aspect of the metencephalon. It includes the Area elliptica, the Ar. aaa
the pyramis and trapezium, and the ectal origins of several nerves.

§ 1192. Area prechiasmatica (az.), Ar. preh.—Fig. 116; Pl. I, Fig. 3,

The ventral aspect of the basis encephali cephalad of the chiasma.

§ 1193. Ar. septalis, Ar. spt—Fig. 117; Pl. I, Fig. 4; Pl. IV, Fig. 16.

The mesal surface of either half of the Septum lucidum ; see pseudocelia, § 1297.

Septal area—F lower, 13, 634. The name is ascribed to Huxley.

§ 1194. Calcar (avis), cle—Gray, A, 625; Quain, A, II, 542.

This is the brief synonym of hippocampus minor, ergot and unciform eminence. It des-
ignates a projection into the postcornu of man and monkeys, and has not been observed in
the cat, where the postcornu is not normally developed.

474 ANATOMICAL TECHNOLOGY.

§ 1195. Callosum (az.), cl.—Fig. 88, 104, 115, 117, 122, 125; Pl. I, Fig 4; Pl. Il,
Fig. 18; Pl. IV, Fig. 15-17, 20. Gray, A, 623; Quain, A, II, 537.

Syn.—Corpus callosum, commissura magna, trabs cerebri.

A broad band of nerve fibers connecting the mesal surfaces of the hemispheres along a
line dorsad of the fornix and curved ventrad at each end. The cephalic curvature is the
genu and the caudal the splenium.

In nearly its caudal half, the callosum is in contact with the fornix at the meson and
for 1-2 mm. laterad (Fig. 122, § 1149). With care the callosum may be dissected up from
the fornix, and at the splenium the two are then seen to be continuous. In fact, a simple
way of describing their relations is the following :—

The two hemispheres, originally separate, become united along two lines represented
by the callosum and the fornix. The former is approximately straight, excepting at its
ends, the cephalic corresponding with: the genu and rostrum. The latter forms the seg-
ment of a circle, but the caudal end turns dorsad to become continuous with the caudal
end of the callosal line which is curved ventrad at the splenium.

The fibers constituting the larger part of the callosum pass dorsad of the procelia and
thus constitute its roof; the fibers of the fornix pass ventrad of the proccelia and thus
enter into the composition of its floor ; the fibers of the splenium are intermediate, and are
partly continued into the hypocampa and partly into the general caudal part of the hemi-
sphere. These relations are indicated in Pl. IV, Fig. 19, 20.

Notwithstanding the fact that the callosum exists only in mammals, is larger, as a
rule, in the higher members of the group, and presumptively has great physiological
importance, there are recorded several cases of its more or less complete absence from man,
once without serious lack of mental or physical power (Malinverni [Henry, 2]); and the
senior author has reported (2.3) a case of its complete absence in a cat which is not
known to have been peculiar during life.

§ 1196. Canalis centralis (myelonis), (az.), Cn. ce.—Fig. 99, 100, 109, 118, 117; Pl. II,
Fig. 4. Gray, A, 68; Quain, A, II, 500.

The central canal of the “ cord.”

The mesal canal of the myelon, which expands cephalad and is opened up into the dor-
simesal fissure so as to form the metacelia. In the cat this canal persists through life, but
in man it is said to be commonly obliterated in the adult, excepting at the cephalic end.

§ 1197. Carina (az.), c1.—This is a mesal ridge upon the ventro-caudal aspect of the
fornix, extending from the crista the entire length of the delta. It varies in distinctness
and does not appear upon any of the preparations here figured, but is very well marked
in Prep. 530, M. C. U.

§ 1198. Cauda striati, cd. s.—This is not distinctly shown in the figures and has not
been accurately observed by us.

The slender tail-like prolongation of the striatum.

Former writers who mentioned this portion of the striatum (Todd, Gratiolet, Hirsch-
feld, and Cuvier, B, III, 51) gave it no special name. Recently it has been described by
Da:ton (1, 12) under the name of surcingle. Having vainly requested him to substitute
for this vernacular term some equivalent technical one, the senior author reluctantly pro-
posed (9, 134) the name here employed, which is approved by Spitzka, 7, 165.

§ 1199. Cella media, cel. m—PI1. IV, Fig. 15; § 1147. Gray, A, 625; Quain, A,
II, 540.

The central or intermediate portion of the proce/ia ; its limits are not defined.

§ 1200. Cerebellum (az.), cbi.—Fig. 88, 104, 118-117; Pl. I, Fig. 1, 2; Pl. Il, Fig.
3, 4; PL IV, Fig. 15; §1074(C). Gray, A, 632; Quain, A, II, 515.

Syn.—Cerebrum parvum.

SYNONYMS AND REFERENCES. 475

Next to the cerebrum, the largest portion of the brain. A single foliated mass, form-
ing with the valvula the dorsal part of the epencephalon and constituting the roof of part
of the epiccelia.

§ 1201. Cerebrum (wz.), cb.—Fig. 88, 104, 113-117, 124, 125; Pl. I, Fig. 1,2; Pl. II,
Fig. 3,4; Pl. III, Fig. 5, 6, 13; Pl. IV, Fig. 14-20. Gray, A, 615; Quain, A, II, 522.

Syn.—Prosencephalon, hemisphere.

The largest portion of the brain, forming two convoluted lobes between the Lobi olfac-
torii and the thalami ; the former.are partly, the latter wholly, covered by them. ‘The
striata and hypocampe are thickenings of certain parts.

The thalami and optici are not properly ‘‘ internal parts of the cerebrum.”

§ 1202. Chiasma (az.), ch.—Fig. 116-118; Pl. I, Fig. 3,4; Pl. II, Fig. 5, 11; Pl. IV,
Fig. 16. Gray, A, 621, 639; Quain, A, II, 536.

Syn.—Chiasma nervorum opticorum, optic commissure.

The subcylindrical x-shaped mass at the base of the brain formed by the union and
decussation of the two optic tracts ; from it the WN. optici pass to the eyes.

Remark —We are not aware that special observations have determined the extent of
the crossing or decussation of the fibers at the chiasma in the cat ; the precise arrange-
ment seems not to have been determined for man (Meynert [Stricker, A, 688]; Ferrier,
A, 72; Wadsworth, 7, 528).

§ 1203. Cimbia, cmb.—Fig. 116, 118; Pl. II, Fig. 3; Pl. III, Fig. 9,11; § 1142.

Syn.—Tractus transversus pedunculi—Gudden, as quoted by Meynert (Stricker, A, 787).

A fibrous band crossing the Crus cerebri just cephalad of the ectal origin of the WV. ocu-
lomotorius. It may be traced from between the opticus and the postgeniculatum to near
the ventrimeson, where it suddenly enters the crus.

The senior author has suggested (14, 554) that the cimbia may be regarded as indicat-
ing the line of junction between the mesencephalic and diencephalic portions of the crus.
The name was proposed as a brief substitute for Gudden’s descriptive term ; it signifies in
architecture a band or fillet about a column.

§ 1204. Cinerea, (Substantia), cin.—Pl. Ill, Fig. 18; Pl. IV, Fig. 14, 15, 20; § 995.
Gray, A, 622 ; Quain, A, II, 558; Meynert (Stricker, A, 651).

Syn.—Gray matter, ganglionic or cellular nervous tissue, vesicular neurine.

The myelonal cinerea has been mentioned in § 998. The encephalic cinerea is arranged
by Meynert (Stricker, A, 651) in four categories : cortex cerebri ; basal ganglia [striata and
thalami] ; central tubular gray (lining the ccelie] ; cerebellar cinerea. The central tubular
gray is the subject of a paper by Spitzka (7).

§ 1205. Clava, clv.—PI. III, Fig. 12. Gray, A, 612; Quain, A, II, 505.

Syn.—Processus clavatus, funiculus gracilis, pyramis posterior.

The slender fibrous band forming the margin of the metaccelia. It is the cephalic con-
tinuation of the slender “ posterior median column ” of the myelon.

The name is used in accordance with the remark of Spitzka (7, 165). We have not
encountered it elsewhere.

§ 1206. Columna dorsalis (myelonis), C?m. d—Fig. 112; Pl.I, Fig. 1; Pl. U, Fig. 12.
Gray, A, 605; Quain, A, II, 494.

Syn.—Columna posterior, the “ posterior white column of the cord.”

Excepting in Fig. 112, no distinction is indicated between the larger Clm. dorsalis and
the smaller and more mesal “‘ posterior median column,” which is commonly regarded as
ae a part thereof, and is continued as the clava.

$ 1207. Columna fornicis, Clm. f.—Fig. 113, 117, 123 ; Pl. II, Fig. 4 Pl, Ill, Fig.
13 ; “PL. IV, Fig. 14, 16, 20; § 1145. Gray, A, 628; Quain, A; II, 548. .

476 ANATOMICAL TECHNOLOGY.

Syn.—-Crus fornicis anterius, anterior pillar of the fornix.

The fibrous fasciculus which forms the cephalic boundary of the porta, extends ventrad —
to the albicans and dorso-caudad as the lateral half of the body of the fornix. The columna
is a differentiated part of the embryonic terma and is continuous with the hemiseptum.

The two columne are-separated by the Recessus aule and conjoined by the Commissura
Sornicis.

§ 1208. Columna lateralis (myelonis), Clm. 1.—Fig. 104, 112 ; Pl. I, Fig. 1,2; Pl. I,
Fig. 8. Gray, A, 605; Quain, A, II, 494.

’ The lateral white column of the ‘‘ cord.”

§ 1209. Columna ventralis (myelonis), Cém. v.—Fig. 112 ; 116; Pl. Il, Fig.3. Gray,
A, 605 ; Quain, A, IT, 494.

The “ anterior white column of the cord.”

§ 1210. Commissura fornicis (az.), Cs. f.—Pl. IV, Fig. 14.

This name was provisionally applied by the senior author (74, 548) to what appears in
some preparations to be a transverse band just ventrad of the crista fornicis.

§ 1211. Commissura habenarum (az.), Os. h.—Fig. 117; Pl. Ul, Fig. 4; Pl. III,
Fig. 6; § 11438.

A narrow band of ‘apparently nervous tissue connecting the caudal ends of the habene
and constituting the cephalic boundary of the Foramen conarii.

§ 1212. Conarium (az.), en.—Fig. 111, 112, 114, 117; Pl. Il, Fig. 4; Pl. III, Fig. 7,
10: $$ 1084, 1143. Gray, A, 630; Quain, A, II, 549.

Syn.—Glandula pinealis, epiphysis cerebri.

A subglobular mass forming a part of the roof of the diacelia just cephalad of the
postcommissura. There is no good evidence of its true nervous structure, and its functions
are unknown,

§ 1213. Cortex, cta—Fig. 123; Pl. Il, Fig. 4; Pl. II, Fig. 18; Pl.-IV, Fig. 15, 20;
§ 1147. Gray, A, 623; Quain, A, I, 521, 559.

The ectal cinerea of the cerebrum or cerebellum, more commonly of the former. It
consists of several more or less distinct layers, whose structure and relations are figured
and described by Meynert (Stricker, A, 660) and Bevan Lewis (7, 88).

§ 1214. Crista fornicis (az.), Ors. f.—Fig. 117; Pl. Il, Fig. 4; Pl. Ill, Fig. 18 ; PL. IV,
Fig. 14, 16, 20.

A hemispherical or semioval] elevation of the caudal surface of the fornix just dorsad of
the Recessus aulz, between the porte and opposite the cephalic convexity of the medi-
commissura. It is continued dorso-caudad as the carina.

The crista seems not to have been observed prior to the senior author’s paper (7). He
has observed it in the brains of asheep and human subject, but has not looked further for
it. Probably it will be found in most if-not all mammals. Its histological composition,
function and morphological significance are unknown. We can only surmise that it may
mark the dorsal limit of the primitive terma.

§ 1215. Crus cerebri, Cr. cb—Fig. 111, 112, 116-118; Pl. II, Fig. 3, 4; Pl. III, Fig.
9, 11.

Syn.—Pedunculus cerebri, caudex cerebri, crus anterius medulle oblongate.

The fibrous mass forming with its fellow the support of the mesencephalon and dien-
cepha.on, and extending from the pons to the chiasma.

§ 1216. Crus olfactorium, Cr. o/.—Fig. 116, 117, 124, 125; Pl. II, Fig. 3,4; Pl. II,
Fig.5; § 1139. Gray, A, 620, 637; Quain, A, II, 566.

. Syn.—Crus rhinencephali, Owen, A, I, 298; olfactory nerve or tract, Quain, A, II,
566 ; Gray, A, 638.

SYNONYMS AND REFERENCES. 477

The contracted portion of the brain between the prosencephalon and the Lobus. olfac-
torius. Its ventral surface is continuous caudad with the Tractus rhinalis.

§ 1217. Delta (fornicis), (az.), dt.—Fig. 120; Pl. IV, Fig. 14.

The triangular entocelian area of the ventro-caudal surface of the fornix, constituting
the roof of the aula. Its base coincides with a line between the porte, and its two other
sides are ripe, lines of reflection of the endyma upon the intruded auliplexus. It does not
appear to have been observed prior to the senior author’s paper (9).

§ 1218. Diaccelia (az.), de.—Fig. 110-118, 117, 120, 122; Pl. Il, Fig. 4; Pl. III, Fig. 7;
Pl. IV, Fig. 16; $1143. Gray, A, 629; Quain, A, I, 546.

Syn.—Ventriculus tertius, third ventricle, middle ventricle, mediventricle.

The irregular mesal cavity between the thalami, bounded dorsad by the diatela, post-
commissura and conarium ; ventrad by the diencephalic portion of the Crura cerebri, the
albicantia, Tuber cinereum and terma (reinforced by the chiasma), continuous cephalad
with the aula and caudad with the mesoceelia. Most of its dorsal portion is occupied by
the medicommissura. The diaccelia represents the cavity of the primitive “‘ anterior cere-
bral vesicle.”

The reasons for ndoptiiie this and the other names for the encephalic cavities are stated
in § 1064 and the papers there referred to.

§ 1219. Diaplexus, dpx—Fig. 112, 1138, 117, 122; Pl. II, Fig. 4; PI. IV, Fig. 16;
$1148. Gray, A, 628; Quain, A, II, 545.

Syn.—Plexus choroideus ventriculi tertii, plexus choroideus medius.

The string-like vascular plexus extending the entire length of the diacelia on each
side; it is slightly attached to the diatela and has firmer connections by vessels at its
ends, which are not clear to us. It is continuous cephalad with the awiiplerus. For the
name, see § 1066.

§ 1220. Diatela (az.), dtl—Fig. 111-113, 117, 122; Pl. III, Fig. 10. Reichert, A, 155.

The membranous or atrophied nervous roof of the diaccelia. Its exact composition has
not been ascertained, but it seems to consist of something more substantial than endyma.
Judging from current statements respecting the roof of the “‘ third ventricle,” this delicate
tela is usually torn off with the fornix, and no notice is taken of the ragged lines of its
separation along the Sulcus habene on each side. In the Museum of Cornell University,
however, there are preparations of the cat and rabbit which show the diatela after the
removal of the fornix and velum, while the rip@ or lines of reflection are apparent upon
many others, as in that shown in PI. III, Fig. 7.

§ 1221. Diencephalon (az.), den,.—Fig. 88, 110-113, 116-118, 122; Pl. Il, Fig. 3, 4;
Pl. Ill, Fig. 6, 7, 9-11; Pl. IV, Fig. 16, 18, 19; $1061. Gray, A, 111; Quain, A, II, 755.
Syn.—Deutencephalon, thalamencephalon, interbrain, ’tweenbrain.
The encephalic segment between the mesencephalon and the prosencephalon. Its
cavity is the diaccelia (“third ventricle ”), and its chief constituents are the thalami.

§ 1222. Dura (mater), d.—Fig. 88; § 1104. Gray, A, 606; Quain, A, II, 569.

The firm membrane which lines the cranial cavity, is reflected upon the osseous tento-
rium (§ 552), and is produced between the hemispheres on the falx cerebri ; it is an ento-
cranial periosteum.

Notwithstanding its feminine form, dura is frequently employed without the substan-
tive mater.

§ 1223. Eminentia auditoria, Hm. av.~P. I, Fig. 2; Pl. II. Fig. 3; § 1140.

The name was suggested by the senior author (74, 536) for the distinct elevation just
laterad of the trapezium, whence springs the WV. auditorius. It is continuous mesad with
a Tractus auditorius, which does not appear in the figures.

478 ANATOMICAL TECHNOLOGY.

§ 1224. Endyma, end.—Fig. 111, 112, 121-123; § 1079. Gray, A, 630; Quain, A,
II, 540.

Syn.—Ependyma, pia mater interior.

The epithelial lining of the cceliz, which is reflected upon the plexuses.

§ 1225. Epencephalon (az.), epen.—Fig. 88, 104, 110-114, 117; Pl. 1, Fig.1, 2; Pl. Il,
Fig. 3, 4; Pl. Ill, Fig. 12; Pl. IV, Fig. 15. Gray, A, 111; Quain, A, I, 755.

The encephalic segment including the cerebellum, pons, peduneuli, valvula, and the cor-
responding part of the ‘‘ medulla.”

While it is convenient to recognize the segment, its precise limits are difficult to
assign, and Spitzka (7, 165) inclines to abandon the segmental name altogether. If the
caudal boundary coincides with the margin of the pons, the trapezium of man will be
included therewith, while that of the cat remains in the metencephalon.

§ 1226, Epiccelia (az.), epe.—Fig. 110-113, 117; Pl. Il, Fig.4; § 1141. Gray, A, 635;
Quain, A, II, 512.

Syn.—Ventriculus quartus or fourth ventricle, the cephalic part ; ventriculus cerebelli.

The cavity of the epencephalon, covered by the cerebellum and valvula.

§ 1227. Fasciola, fscl.—Fig. 121; Pl. IV, Fig. 14, 17. Gray, A, 627; Quain, A,
II, 545. ;

Syn.—Fascia dentata, fasciola cinerea.

The somewhat thickened margin of cinerea along the fimbria. In man the ventral
portion has commonly been called fascia dentata ; in the cat, however, there is no denticu-
lation, and the name fascia is certainly misleading; hence the senior author proposed
(9, 185) to employ fasciola for the whole.

§ 1228. Fimbria, fmb.—Fig. 121; Pl. IV, Fig. 14,17. Gray. A, 627; Quain, A, II,
542, 544.

Syn.—Corpus fimbriatum, tenia hippocampi.

The strip of alba forming the border of the hypocampa and one of the boundaries of
the rima.

§ 1229. Fissura ansata, 7. an.—This and the other cerebral fissures (including all
the fissures named in § 1129 excepting the four appertaining to the myelon) are briefly
discussed in the last part of this chapter. See especially the Table of Synonyms (§ 1342).

§ 1230. Fissura dorsilateralis (myelonis), / dil—Fig. 112; Pl. I, Fig. 1. Gray, A,
605 ; Quain, A, II, 493.

§ 1231. Fissura dorsimesalis (az.), F. dms.—Fig. 112; Pl. I, Fig. 1; Pl. Ill, Fig. 12.
Gray, A, 605 ; Quain, A, IT, 493.

Syn.—The “ posterior fissure of the cord.”

§ 1282. Fissura ventrilateralis, 7. o].—Fig. 112, 116; Pl. Il, Fig. 3. Gray, A, 605;
Quain, A, II, 493. ~
. § 1233. Fissura ventrimesalis (az.), F. oms.—Fig. 99, 100, 109, 112; Pl. Il, Fig. 3.
Gray, A, 605; Quain, A, II, 493.

The “ anterior fissure of the cord.” -

§ 1234. Flocculus, flc.—Gray, A, 634; Quain, A, II, 518

We are not sure that this is represented in the cat, although it has been homologized
by some with the Zobulus appendicularis.

§ 1235. Foramen czcum (az.), Fm. ce—PI. Il, Fig. 8,4. Gray, A, 610; Quain, A,
II, 504,

Syn.—Fossa ceca—Spitzka, 3, 6.

SYNONYMS AND REFERENCES. 479

The name here employed was used by Vicq d’Azyr (A, Pl. XVIII, “ 48”), and is given
in Dunglison; it should, we think, be retained, notwithstanding the somewhat unusual
use of foramen.

” g 4236. Foramen conarii (az), Fm. en—PI. II, Fig. 6.

The interval between the postcommissura and the Commissura habenarum.

§ 1287. Foramen infundibuli (az.), Fim. inf—Fig. 118; Pl. IIT, Fig. 11,

The orifice left after removal of the hypophysis and infundibulum.

§ 1238. Fornix (az.), f.—Fig. 117, 122 ; Pl. U, Fig. 4; Pl. Il, Fig. 18; Pl. IV, Fig.
14-20; $$ 1144, 1172, Gray, A, 627; Quain, A, II, 548.

Syn.—Camara, testudo cerebri.

A subtriangular fibrous sheet, forming successively the cephalic boundary of the aula
and porte, the roof of the aula, and part of the floor of the proceeliw. (See § 1457.)

The form, constitution, direction and relations of the fornix are exceedingly difficult to
describe, and indeed are not fully understood. The fornix proper includes the following
parts : columne, commissura, crista, carina, delta and lyra. The fimbrie are its caudo-lat-
eral prolongations to the tips of the hypocampal lobules, while the fibrous fasciculi consti-
tuting the columne are described as beginning in the thalami, passing ventrad to form a
figure-of-eight turn in the albicantia, then passing dorsad just caudad of the preecommissura
to form the lateral halves of the “ body ” of the fornix, which again are continued into the
fimbriew. Between the thicker lateral parts of the body of the fornix is the thin and ill-
defined surface known as lyra.

The caudal portion of the fornix is in contact with the ventral aspect of the callosum
at and for a short distance laterad of the meson, and the two are continuous at the sple-
nium. See callosum (§ 1195).

The feline fornix is proportionally much wider than the human, and may be torn into
several bands on each side, as indicated by the v-shaped lines in Pl. IV, Fig. 14.

§ 1239. Genu (az.), g.—Fig. 117; PL II, Fig. 4; PLIV, Fig.17. Gray, A, 623; Quain,
A, II, 538.

The knee-like cephalic curvature of the callosum, ending in the rostrum.

§ 1240. Habena, h.—Fig. 117, 122 ; Pl. Il, Fig. 4; Pl. IV, Fig. 16; $1148. Gray, A,
630 ; Quain, A, II, 549.

Syn.—Habenula, pedunculus conarii.

The ridge along the dorso-mesal aspect of the thalamus ; it may be said to be the dor-
sal limit of the mesal surface, as the Sulcus habene is the mesal limit of the dorsal surface.

The habena terminates on the cephalic slope of the thalamus as a more or less distinct
tubercle which marks the dorsal limit of the porta ; it joins its platetrope by the Cs. habe-
narum, forming the cephalic boundary of the Fm. conarii.

§ 1241. Hemiseptum (cerebri), hmspt.—Fig. 117; Pl. IV, Fig. 16.

This is the lateral half of the septum (lucidum), which see (§ 1815) ; its mesal surface,
the Area septalis, is joined with its platetrope by connective tissue (§ 1187, 4).

§ 1242. Hemisphera, hem.—Fig. 104, 110-118, 124, 125; Pl. I, Fig. 1,2; Pl. Ul, Fig.
3,4; Pl. Ill, Fig. 5, 6, 11, 18; Pl IV, Fig. 14-20.

Syn.—Ganglion hemisphericum, hemicerebrum, lobus prosencephalicus:

The lateral half of the largest portion of the brain, united with its platetrope by the
fornix, callosum and precommissura. Its cavity is the procelia, and the striatum, hypo-
campa, and (in man and monkeys) calcar are thickenings or involutions of the parietes.
The surface is convoluted, presenting fissure and gyri. The cinerea is mostly near the
surface, forming the cortex:cerebri. See cerebrum, § 1201.

480 ANATOMICAL TECHNOLOGY.

§ 1248. Hypocampa, Amp—Fig. 122; Pl. Ill, Fig. 11; Pl. IV, Fig. 14, 15, 18, 19;
§ 1147. Gray, A, 627; Quain, A, Il, 541.

Sym.—Hippocampus major, cornu Ammonis,

A thickening and involution of the parietes of the medicornu, forming its floor.

The convexity constituting the hypocampa corresponds with a well-marked ectal fissure,
the F. hypocampe. The ectal surface also presents the fascivla, fimbria and F. fimbrie.

The grounds for preferring the name employed by Vicq d’Azyr (A, 61, Pl. VII, Fig,
1,3; Pl. VIII, Fig, 2), and ascribed by him to Arantius and Varolius, are briefly stated by
the senior author (9, 125 ; 14, 541).

§ 1244. Hypophysis (az), hph.—Fig. 111, 112, 116, 117; Pl. II, Fig. 8, 4; § 1084.
Gray, A, 621; Quain, A, II, 535; Balfour, A, I], 358.

Syn.—Corpus pituitarium, pituitary gland.

A subcordate mass attached to the Tuber cinereum by a tube, the infundibulum. It
does not appear to consist of true nervous tissue, and its functions are wholly unknown ;
but it is constant throughout the vertebrate series, excepting Amphioxus ; see Owen, 1.

§ 1245. Incisura hypocampe, Inc. hmp.—Fig. 118; Pl. IV, Fig. 11.

A more or less distinct crenation of the mesal eardar of the hypocampal lobule, where
it abuts against the Tractus opticus.

§ 1246. Infundibulum (az.), inf.—Fig. 116, 117; Pl. I, Fig. 3.4. Gray, A, 621;
Quain, A. IT, 535.

The short thin-walled tube by which the hypophysis is connected with the Tuber
cinereum.

It has several antiquated synonyms, but the name here given is almost universally
employed.

§ 1247. Insula, ins.—Gray, A, 616; Quain, A, II, 525.

Syn.—Insula Reilii, Gyri operti, Lobulus Fissure Sylvii, Lobulus Corporis striati.

In man and monkeys, and perhaps some other mammals, the cortex cerebri opposite
the striatum is elevated and more or less convoluted. By the subgrowth of the neighbor-
ing regions, it becomes nearly or quite concealed, whence the name Gyri operti. The
insula has not been identified in the cat; see striatum, § 1318.

§ 1248. Interopticus, inop—tThe interoptic lobe of some Reptiles (Spitzka, 4,5, 71);
we have not observed it in the cat.

§ 1249. Iter (az.), it—See mesocelia (§ 1263). The entire name is iter a tertio ad
quartum ventriculum, but as the only other iter (iter ad infundibulum) is rarely used, the
senior author has suggested (9, 135) the single word as a convenient designation of the
contracted mesoccelia of mammals.

§ 1250. Limes alba, /m. elb—Fig. 116; Pl. I, Fig. 2; Pl. I, Fig. 3

The Radix lateralis of the olfactory lobe presents two distinct tracts or paths for
which, from their color, the senior author has proposed (9, 135; 14, 537) the names limes
alba and limes cinerea. The latter is laterad of tbe fornix. ;

§ 1251. Limes cinerea, lm. cin.—See limes alba (§ 1250).

§ 1252. Liquor celiarum, /g. ¢.—The liquor ventriculorum cerebri. The ccelian sur-
faces are always moistened by a serous liquid, secreted presumably by the plexuses. We
have never observed an abnormal increase of this liquid in cats, but hydrocephalus has
been recorded of several domesticated animals as well as of man.

§ 1253. Lobulus appendicularis (cerebelli). Z/. ap. —Fig. 116: Pl. L. Fig. 2; Pl. II,
Fig. 3.

The name has been applied to the more or less distinct projection consisting of two or

SYNONYMS AND REFERENCES. 481

three folia or lamin of the lateral lobe of the cerebellum. It rests in the Fossa appen-
dicularis of the periotic bone (Fig. 59, 7s. ap.). It is larger in dogs (see Wilder, 11, 217,
Fig. 1), and very large and long in the bear and seal. The name flvcculus has sometimes
been applied to it, but its homology with that part of the human cerebellum is not clear.

§ 1254. Lobulus hypocampe, Ll. hmp.—Fig. 116; Pl. I, Fig. 1; Pl. Il, Fig. 3; Pl.
Ul, Fig. 6; Pl. IV, Fig. 14, 17.

Syn.—Alveus (?), subiculnm (7), protuberantia natiformis.

The senior author had suggested (9, 185) for this the single name monticulus, but _
withdrew it (44, 537) on the representation of Spitzka (7, 165) that the name had been
applied to a part of the cerebellum.

§ 1255. Lobus lateralis (cerebelli), Z. /—Fig. 116; Pl. I, Fig. 1, 2; Pl. II, Fig. 3;
Pl. IV, Fig. 15. Gray, A, 634; Quain, A, II, 517.

Syn.—The lateral lobe of the cerebellum. This and the mesal lobe or vermis are not
well defined from each other. The ZLobulus appendicularis is an appendage of the L.
lateralis. '

§ 1256. Lobus olfactorius, Z. ol—Fig. 116, 117; Pl. I, Fig. 1, 2; Pl. II, Fig. 3, 4;
Pl. IV, Fig. 15-19. Gray, A, 636; Quain, A, II, 506.

Syn.—Bulbus olfactorius, olfactory lobe, olfactory nerve.

The enlarged extremity of each half of the rhinencephalon which gives off the olfac-
tory nerves. In man, it and the crus are so small as to have been called olfactory nerve.
It contains, however, a distinct rhinoccelia ; see pero and pes.

§ 1257. Lobus temporalis, Z. tmp.—Pl. I, Fig. 2; Pl. Il, Fig. 3; Pl. Ill, Fig. 5; Pl.
IV, Fig. 14. Gray, A, 616; Quain, A, IT, 580.

That portion of the hemisphere which is caudad of the Sylvian fissure. Its dorsal
limit is not defined. Its ventral end is the Lobulus hypocampa@, and the surface ventro-
mesad of the J. postrhinalis is the Tractus postrhinalis.

§ 1258. Lyra (az.), ly—Fig. 122; Pl. IV, Fig. 14. Gray, A, 628; Quain, A, II, 544.

Syn.—Psalterium, corpus psalloides, lamina medullaris triangularis cerebri, spatium
trigonum.

This name is applied to part of the ventral surface of the fornix. It is not well defined.

§ 1259. Medicommissura (az.), mcs.—Fig. 117, 122 ; Pl. II, Fig. 4; Pl. Ill, Fig. 6, 18;
Pl. IV, Fig. 16; § 1148. Gray, A, 630; Quain, A, II, 546.

Syn.—Commissura media, commissura mollis, the middle or soft commissure.

The junction of the two thalami in the dorsal part of the diacelia. It seems to consist
of cells rather than fibers.

§ 1260. Medicornu, mew.—Fig. 113, 118, 119, 121; Pl. III, Fig. 11; Pl. IV, Fig.
14,15; § 1147. Gray, A, 626; Quain, A, II, 541.

Syn.—Cornu medium, cornu descendens, cornu inferius, digital cavity.

The strongly curved extension of the cella media of the proccelia to the tip of the L.
temporalis ; its floor is formed by the hypocampa.

§ 1261. Medipedunculus (cerebelli), mpd.—§ 1141. Gray, A, 655; Quain, A, II, 516.

Syn.—Pedunculus medius, crus medium, processus e cerebello ad pontem, brachium
pontis.

The subcylindrical fibrous mass connecting the pons with the cerebellum. It is over-
hung and concealed by the L. lateralis. It was called pontibrachium by the senior author
(9, 136) under a misapprehension.

§ 1262. Mesencephalon (az.), msen.—Fig. 110-114, 116-118; § 1061. Gray, A, 111;
Quain, A, II, 755.

Syn.—Midbrain. It embraces the optici, postoptici and crura.

31

482 ANATOMICAL TECHNOLOGY.

§ 1268. Mesoceelia (az.), msc.—Fig. 110-118, 117; Pl. II, Fig. 4; § 1055. Gray, A
680; Quain, A, II, 552.

Syn.—Aqueeductus Sylvii, iter a tertio ad quartum ventriculum, ventriculus opticus,
ventriculus mesencephali.

The mesencephalic cavity, enclosed by the crura cerebri, the optici and postoptici, and
opening cephalad into the diaccelia and caudad into the epiccelia,

§ 1264. Metaceelia (az.), mte—Fig. 118, 117; Pl. Il, Fig. 4; § 1065. Gray, A, 635;
Quain, A, II, 512.

Syn.—Ventriculus quartus, caudal portion. As has been admitted ($ 1225), it is diffi-
cult, perhaps impossible, to define accurately the limits of the metaccelia and epiccelia.

§ 1265. Metaplexus, mtpz.—Fig. 116; Pl. Il, Fig. 3. Luschka, A, Pl. III; Gray, A,
636 ; Quain, A, II, 513.

Syn.—Plexus choroideus ventriculi quarti, plexus chorvideus inferior.

We have not yet satisfied ourselves respecting the nature and connections of this
plexus, and have provisionally designated the prominent plexus between the dorsal border
of the medulla and the cerebellum as the metaplexus lateralis.

§ 1266. Metencephalon (az), mten.—Fig. 110-1138, 116; Pl. I, Fig. 1, 2; Pl. U, Fig.
8, 4; Pl. Ill, Fig. 12. Gray, A, 111; Quain, <A, II, 755.

Syn.—Meduila, as far as the pons. See §§ 1061, 1225.

§ 1267. Metatela (az.), mttl.—Fig. at. 112, 116; Pl. Il, Fig. 4; Pl. Ill, Fig. 12.
Luschka, A, PI. III.

Syn.—Tela choroidea inferior.

Notwithstanding this atrophied roof of the metacclia is so obvious with Amphibia as
to have been once mistaken for the cerebellum, it is usually ignored in the dissection of
the mammalian brain, probably because of its tenuity and its liability to be torn off with
the cerebellum,

As has been stated in several places, there is much to be learned respecting the struc-
ture of the metatela, the arrangement of the metaplexus and the ‘‘ Foramen of Magendie.”
The probability of the existence of the latter is increased by the experiments of West-
brook (2), which should be repeated upon the cat; detailed descriptions and enlarged
figures are required (§ 1082).

§ 1268. Myelon (az.), my.—Fig. 88, 104, 109-118, 116; Pl. I, Fig. 1,2; Pl. Il, Fig.
3,4. Gray, A, 604; Quain, A, II, 489.

Syn.—Medulla spinalis, spinal cord, spinal marrow, chorda spinalis.

It is described in § 1006 and in connection with the figures above named.

§ 1269. Nervus abducens, WV. ab.—This and the other cranial nerves (i—xii) are
treated of in the next chapter. The ectal origins are shown in Fig. 116 and in Pl. I,
Fig. 3.

§ 1270. Obex, ob.—We have not yet identified this in the cat. It is mentioned by
Spitzka (3, 18), and also, we think, by Meynert (Stricker, A).

§ 1271. Oliva, olv.—According to the Am. Jour. of Neurology, ete: (I, 102), the eleva-
tion called Area elliptica (Fig. 116; Pl. Il, Fig. 3, Ar. e.) represents the oliva or Corpus
olivarium, notwithstanding the funiculi of the WV. hypoglossus emerge laterad of it.

§ 1272. Opticus (Lobus), op.—Fig. 110-112, 114, 116, 117; Pl. II, Fig. 4; Pl. Il,
Fig. 7, 8, 9,12; Pl. IV, Fig. 18,19; $1142. Gray, A, 631; Quain, A, II, 551.

Syn.—Corpus bigeminum anterius, natis cerebri, one of the corpora quadrigemina,
cephalic lobe of the mesencephalon.

As seen in PI. III, Fig. 7, 8, 9, the opticus is more regularly convex and less elevated
than the postopticus.

SYNONYMS AND REFERENCES. 483

§ 1273. Pero (olfactorius), po.—PI. IV, Fig. 16; $1139. Meynert (Stricker, A, Fig.
261). :

This name was proposed by the senior author (9, 135) for the softer ectal layer of the
Lobus olfactorius from which the olfactory nerves arise. The word signifies a kind of
boot made of raw hide, and seems more appropriate than the term Bulbus olfactorius
used by Meynert (Stricker, A, 671).

§ 1274. Pes (olfactorius), ps. ol.—Pl. IV, Fig. 16; § 1139. Meynert (Stricker, A,
Fig. 261).

This name was proposed by the senior author (9,136; 74, 538) for the ental and
fibrous portion of the Lobus olfactorius. It is in harmony with the term crus, already in
use, and with pero, which was proposed at the same time, and less apt to be misunderstood
than the term Zobdus ol. used in this restricted sense by Meynert (Stricker, A, 671).

§ 1275. Pia (mater), pi.i—Fig. 111, 112, 121-123; § 1078. Gray, A, 609; Quain, A,
I, 571. ‘

Syn.—Meninx vasculosa, membrana vasculosa, membrana tenuis.

The immediate envelope of the myelencephalon, dipping into the fissures and sup-
porting the vessels. Its relations to the tele and plexuses are not fully understood.

§ 1276. Pons (Varolii), (az.), pn.—Fig. 116, 118; Pl. II, Fig. 3,4; Pl. III, Fig. 9, 11.
Gray, A, 610; Quain, A, II, 511, 756.

Syn.—Pons cerebelli, tuber annulare, protuberantia basilaris.

The bridge-like mass upon the basis encephali connecting the two sides of the cerebel-
lum. It forms a prominent landmark of the mammalian brain, and is not present with
the lower vertebrates.

§ 1277. Porta, p.—Fig. 110-113, 120, 123; Pl. III, Fig. 18; Pl. IV, Fig. 14, 16, 18, 19;
§ 1065. Gray, A, 630; Quain, A, II, 544.

Syn.—Foramen Monroi, lateral orifice of the y-shaped Foramen Monroi.

This more or less constricted communication between the aula and the procelia is
described in connection with the figures above named and in §§ 1096, 1145, 1151. The
reasons for adopting the single word in place of the compound term have been given by
the senior author (3).

§ 1278. Portio depressa (preperforati), Pt. d.—The caudal and depressed portion of
the (Locus) preperforatus, which see ($ 1293).

§ 1279. Portio diencephalica (Cruris cerebri), Pt. den.—Fig. 116, 118 ; Pl. III, Fig. 9,
11; § 1142.

In the cat the Crus cerebri is traversed by the cimbia, and its ventral surface is sepa-
rated thereby into a caudal or mesencephalic portion and a cephalic or diencephalic. The
latter presents a longitudinal ridge, mesad of which is the quadrans, while the postgenicu-
latum lies just laterad of it.

§ 1280. Portio mesencephalica (Cruris cerebri), Pt. msen.—Fig. 116, 118; PI. II,
Fig. 3; Pl. Ill. Fig. 11; § 1142.

This is the part of the crus which is visible upon the undissected brain between the
pons and the hemisphere. See Crus cerebri (§ 1215), cimbia (§ 1208), and Portio dience-
phalica (§ 1279).

§ 1281. Portio prominens (preperforati), Pt. p.—The cephalic, elevated and usually
furrowed portion of the (Locus) preperforatus, which see (§ 1293).

§ 1282. Portiplexus, ppx —Fig. 113, 123.

This name was proposed by the senior author (9, 186) for that small portion of the
plexus which hangs in the porta.

484 ANATOMICAL TECHNOLOGY.

§ 1283. Postcommissura (az.), pes.—Fig. 111, 112, 117; Pl. II, Fig. 4; Pl. IU;
§ 1148. Gray, A, 630; Quain, A, II, 546.

Syn.—Commissura posterior.

Composed of transverse fibers forming the caudal part of the roof of the diaccelia, and
thus joining the dorsal portions of the thalami.

§ 1284. Postcornu, pev.—Gray, A, 625 ; Quain, A, II, 542.

Syn.—Cornu posterius ventriculi lateralis, cavitas digitata.

This caudal prolongation of the proceelia is normally present only in man, monkeys,
seals and cetacea. The hydrocephalous brain of a dog reported by the senior author (23)
presented a distinct postcornu, so that perhaps it may be regarded as normally rudimentary
or undeveloped rather than totally absent in the ordinary mammals.

§ 1285. Postgeniculatum, pgn.—Fig. 118; Pl. III, Fig. 7-11; § 1144. Gray, A, 631;
Quain, A, II, 552.

Syn.—Corpus geniculatum internum.

The elevation at the side of the diencephalon, between the Tractus opticus and the
cimbia. It is proportionally much larger in the cat than in man.

§ 1286. Postopticus, pop.—Fig. 114; Pl. Il, Fig. 2; Pl. Ill, Fig. 7-9; Pl. IV, Fig.
18,19; § 1142. Gray, A, 631; Quain, A, II, 551.

Syn.—Testis cerebri, corpus bigeminum posterius, one of the corpora quadrigemina,
caudal lobe of the mesencephalon.

The marked elevation just cephalad of the cerebellum and valvula.

§ 1287. Postpedunculus, ppd.—S 1141; Gray, A, 635; Quain, A, II, 516.

Syn.—Processus e cerebello ad medullam oblongatam ; restibrachium (Spitzka, 7’, 165).

The fibrous fasciculus passing from the dorsal aspect of the metencephalon dorso-
cephalad to the cerebellum, mesad of the medipedunculus,

§ 1288. Pregeniculatum (Corpus), prgn.—Pl. III, Fig. 7-9; § 1144. Gray, A, 631;
Quain, A, II, 552.

Syn.—Corpus geniculatum externum.

There seem to be no distinct lines of demarcation between the Tractus opticus, the
pregeniculatum and the thalamus.

§ 1289. Postperforatus (Locus), (az.), ppf—Fig. 116, 118; Pl. Il, Fig. 3; Pl. 10, Fig.
11. Gray, A, 621; Quain, A, II, 535.

Syn.—Locus perforatus posticus, pons Tarini.

A small triangular area overhung by the albicantia, and presenting a few pores for the
transmission of vessels. It is apparently smaller than in man.

§ 1290. Precommissura (az.), pres.—Fig. 111, 112,117; Pl. Il, Fig. 4; Pl. IV, Fig.
14, 16, 17; §§ 1067, 1152. Gray, A, 630; Quain, A, II, 546.

Syn.—Commissura anterior cerebri.

At the meson this commissure is a subcylindrical fibrous fasciculus just cephalad of
the Columnez fornicis. It expands laterad and reaches the striata and Crura olfactoria,
which it thus connects across the meson. In man, according to Meynert (Stricker, A, 680),
the connection of the olfactory lobes with the commissure is slight.

§ 1291. Precornu, preu. —Fig. 118, 120; Pl. IV, Fig. 15, 16, 18,19; § 1149. Gray,
A, 625 ; Quain, A, II, 541.

Syn. —Cornu anterius ventriculi lateralis.

The cephalic portion of the proceelia. It is quite high, but compressed, the striatum
projecting into it. The ventro-cephalic end narrows suddenly to become continuous with
the rhinoceelia.

SYNONYMS AND REFERENCES. 485

§ 1292. Prepedunculus, prpd.—§ 1141. Gray, A, 635: Quain, A, II, 576.

Syn.—Pedunculus cerebelli superior, processus e cerebello ad testim, crus cerebelli
superius, testibrachium.

The prepedunculi extend from the cerebellum to the base of the poe ds: and form
the walls of the cephalic and longer part of the epiccelia.

§ 1293. Preperforatus (Locus), prpf.—Fig: 116, 118; Pl. Ul, Fig. 3; Pl. I, Fig. 11.
Gray, A, 621; Quain, A, II, 5386.

Syn.—Locus perforatus anterior s. anticus, anterior perforated space.

The irregular area just cephalad of the chiasma. In man it is comparatively small, but
in the cat it is larger and presents two quite distinct portions, a cephalic which is more
or less elevated and often distinctly marked by longitudinal furrows and ridges, and a cau-
dal which is smaller, depressed, and smooth excepting for the vascular perforations which
characterize the entire area. The two divisions are hence named Portio prominens and
Portio depressa. Between the depressed portions is the slight gray elevation of the terma,
forming part of the floor of the Recessus opticus.

§ 1294. Procelia, pre—Fig. 110-113; Pl. IV, Fig. 15, 16, 18,19; § 1064. Gray, A,
624 ; Quain, A, IT, 539. :

Syn.—Ventriculus lateralis, ventriculus tricornis, lativentriculus, first or second ven-
tricle. sx :

__ The lateral cavity of the prosencephalon, communicating through the porta with the
aula and thus with its platetrope, and with the mesal series of coelize. _ Cephalad it opens
into the rhinoccelia.

_§ 1295. Proplexus, prpe.—Fig. 118, 121; Pl. IV, Fig. 15, 18; §§ 1066, 1149. Gray,
A, 627; Quain, A, II, 545.

_ Syn —Plexus choroideus ventriculi lateralis.

The larger part of this plexus of the proccelia is formed by the intrusion of the velum
or of vessels thereof between the fimbria and the Sulcus limitans so as to appear, still cov-
ered by endyma, in the medicornu. Its length thus coincides with that of the rima.

A smaller portion of the proplexus projects. laterad into the precornu, as shown in PI.
IV, Fig. 18.

Respecting the continuity of the endyma upon the proplexus, see Todd (A, III, 704) ;
Balfour (A, II, 364, Fig. 260, 261); Mivart (B, 267); Gray (A, 627); Quain (A, II, 546).

§ 1296. Prosencephalon (az.), pren.—Fig. 110-118 ; Pl. I, Fig. 1,2; Pl. Il, Fig. 3,4;
PL. Ul, Fig. 5, 6, 11,13; Pl. IV, Fig. 14-20; §§ 1061, 1138, 1145. Gray, A, 111; Quain,
A, Il, 759.

Syn.—Cerebrum, hemisphere, forebrain.

The cavities of the prosencephalon are the awa, the porte and the procelia.

§ 1297. Pseudoceelia (az.), pse.—S§ 1064, 1137 (4), 1162 (2). Gray, A, me: Quain, A,
II, 543.

Syn.—Ventriculus quintus, ventriculus septi pellucidi, ventriculus Sylvii, incisura
septi, sinus septi pellucidi, fifth ventricle.

In man the mesal surfaces of the hemispheres between the callosum and fornix are
separated by an interval, the “ fifth ventricle.” In the cat the two hemisepta are in con-
tact, and the pseudoccelia does not exist.

§ 1298. Pyramis, py.—Fig. 116; Pl. Il, Fig. 8,4; § 1140. Gray, A, 612; Quain, A,
II, 504,

Syn.—Corpus pyramidale, prepyramid, ventripyramid, anterior pyramid.

At the side of the meson, just caudad of the pons and extending a little caudad of the

486 ANATOMICAL TECHNOLOGY.

Area ovalis. The pyramids are commonly regarded as continuations of the lateral rather
than of the ventral columns of the myelon.

The use of the short term pyramis was suggested by Spitzka (7, 165).

The “ decussation of the pyramids ” does not appear at the surface, but may be demon-
strated by divaricating their caudal portions.

§ 1299. Quadrans, g.—Fig. 118 ; Pl. III, Fig. 9,11; § 1144.

This name was proposed by the senior author (9, 1386 ; 14, 544) for an area of the ven-
tral aspect of the Crus cerebri which is approximately the fourth of a circle. It is not
always distinctly marked.

§ 1300. Radix intermedia (Cruris olfactorii), Rx. in.—Gray, A, 638; Quain, A,
Il, 537.

Syn.—Radix media, the middle root of the olfactory tract. As stated in § 1161, it is
not apparently differentiated in the cat.

This and the two following technical terms for the olfactory “ roots ” were proposed by
the senior author (9, 1386 ; 74, 538) as less apt to be misunderstood than the curr Snky ver-
nacular words.

§ 1301. Radix lateralis (Cruris olfactorii), Rv. 1—Fig. 116; Pl. UL, Fig. 3; § 1161.
Gray, A, 638 ; Quain, A, II, 536.

Syn.—Radix externa, external root of the olfactory tract.

See Limes alba, § 1250.

§ 1302. Radix mesalis (Cruris olfactorii), Rz. ms.—Fig. 116; Pl. II, Fig. 3, 4; $1161.
Gray, A, 637; Quain, A, IJ, 537.

Syn.—Radix interna, inner or internal root of the olfactory tract.

In man this root is wholly ventral in position, but in the cat it passes obliquely mesad
and i3 continuous with the region between the postradical and preradical fissures.

§ 1803. Radix motoria (Nervi trigemini), Rx. mt.—The smaller motor root of the WV.
trigeminus ; see Chap. XI and Pl. II, Fig. 3.

§ 1304. Radix sensoria (Nervi trigemini), Rx. sm.—The larger and sensory root of
the N. trigeminus ; see Chap. XI and Pl. I], Fig. 3.

§ 1805. Recessus aulz (az.), R. a.—Fig. 117; Pl. Il, Fig. 4; Pl. IV, Fig. 14; § 1172.

The slight space between the Columnez fornicis just ventrad of the Crista and dorsad
of the preecommissura. Its cephalic wall is exceedingly thin and has not received a special
name, but is evidently a part of the original terma.

§ 1306. Recessus opticus (az.), R. op.—Fig. 117, 118; Pl. Il, Fig. 4; Pl. II, Fig. 11.

As best seen in Pl. III, Fig..11, there is a distinct recess just dorsad of the chiasma on
each side. It seems to correspond with what Mihalkovics (A, 79) calls by the name above
given. Together they constitute the ventro-cephalic part of the aula.

§ 1807. Recessus prepontilis (az.), R. prpn.—Fig. 116, 117, 118; Pl. I, Fig. 3, 4;
P}. Ill, Fig. 11.

This name was proposed by the senior author (9, 186: 14, 538) for the mesal pit
formed by the overhanging of the cephalic border of the pons ; it is sometimes quite deep.

§ 1308. Regio aulica (az.), Rg. v—This name was proposed by the senior author
(9, 136 ; 14, 538) for the complex region about the aula. Within a radius of 1 cm. from
the Crista fornicis occur a large number of parts the structure and relations of which are
inadequately known and far from easy to elucidate.

§ 1309. Restiforme (Corpus), rst.—Gray, A, 611; Quain, A, II, 505.

Syn.—Crus e cerebello ad medullam.

This part of the metencephalon is not distinctly shown upon any of the figures, and we

SYNONYMS AND REFERENCES. 48%

have not accurately compared it with the corresponding part in man. As indicated by
the synonym, the restiforme is sometimes regarded as identical with the postpedunculus,
but even if they contain the same fibers, the latter should probably be defined as the con-
tinuation of the former to the cerebellum (Quain, A, I, 505).

Between the restiforme and the Area ovalis is a smooth rounded elevation which we
have not been able to identify. Nearly opposite the cephalie end of the Area elliptica it
ceases, apparently covered in by the union of the parts at its sides,

§ 1310. Rhinencephalon (az.), rhen.—Fig. 110-112, 116, 117; Pl. I, Fig. 1,2; Pl. II,
Fig. 3,4; Pl. IV, Fig. 15-19; § 1061. Quain, A, Il, 755.

This name seems to have been employed first by Owen (A, I, 283) as a convenient des-
ignation of the olfactory lobes and their crura. The observations of Milnes Marshall (3),
as presented by Balfour (A, II, 382), require considerable modification of the views here
adopted respecting the constitution of the encephalic segments. The term rhinencephala
is used by Balfour (A, II, 366); § 1150.

§ 1311. Rhinoceelia, rhe.—Fig. 110-112; Pl. IV, Fig. 16; § 1150. Gray, A, 115;
Meynert (Stricker, A, Fig. 261). ‘

Syn.—Ventriculus lobi olfactorii, ventriculus rhinencephalicus, ventriculus olfactorius.

The cavity of the Lobus olfactorius, communicating with the ventro-cephalic part of
the precornu. Though slender in the cat, it is perfectly distinct, but is either obliterated
in the adult human subject or so small as to have escaped notice. The human olfactory
lobes are rarely obtained in a fit condition for accurate observation.

§ 1312. Rima, 7.—Fig. 118, 121; Pl. Il, Fig. 11; Pl. IV, Fig. 14; §§ 1088, 1144, 1155.
Gray, A, 627; Quain, A, II, 544.

Syn.—Rima transversa cerebri magna, fissura transversa magna, fissura Bichatii.

The line of atrophy or abrogation of the proper nervous parietes of the proccelia from
the dorsal end of the porta to near the tip of the medicornu. Along this line there enters
either the margin of the velum, which is a fold of pia, or vessels therefrom, to constitute
the proplerus. Since, however, the endyma is continued from the margins of the rima
upon the intruded pia or vessels, these latter can be said to enter the proccelia only in the
sense in which an abdominal viscus enters the peritoneal cavity.

Of the two margins of the rima, one is certainly formed by the fimbria, which is con-
tinuous, through the hypocampa, with the caudal and thus with the dorsal part of the
hemisphere. Concerning the other margin we are in doubt. In man it is probably the
Tenia (semicireularis), but this part has not yet been identified in the cat, and we have
not personally examined the Cauda striati. We content ourselves, therefore, with the
general statement that the fimbria lies in the Sulcus limitans and that the proccelian
endyma is reflected upon the proplexus from the fimbria and from the striatum or such
other parts as may form the cephalic slope of the Sulcus. At about 5 mm. from the tip
of the cornu the rima ceases, and the cornu is completely encompassed by nervous sub-
stance.

The Name.—The terms above enumerated are not, strictly speaking, synonyms. They
were all applied under a misapprehension still commonly entertained that there is a lack
of ali the celian parietes along a line extending between the tips of the medicornua, so
that the medicornua and diaccelia were in direct communication both with each other and
with the ectal surface of the brain. With human brains in the condition in which they
frequently are obtained, removed without sufficient care and roughly handled, such a solu-
tion of continuity may easily be demonstrated ; but it is certainly artificial, and the names
applied to it need not be retained in the same sense. To avoid, however, the introduction
of a new term, the senior author proposed (9, 1386; 14, 541) the single short word rima

488 ANATOMICAL TECHNOLOGY.

to signify so much of the “‘ rima transversa cerebri magna” as has been indicated above,
When used for the interval between the chorde vocales, the compound term rima glottidis
is commonly employed.

§ 1313. Ripa, rp.—PIl. II, Fig. 7; Pl. IV, Fig. 14.

This name was proposed by the senior author for the line formed by the rupture of the
endyma along the lines of its reflection from entoccelian surfaces. It is a ragged edge of
endyma, sometimes quite distinct, as in Pl. III, Fig. 7. The ripa may be traced along the
Sulci habenarum after removal of the diatela, along the margins of the delta, along both
borders of the rima and on the thalamus and fornix at the nearly oppesite points whence
the endyma is reflected upon the portiplexus.. The surfaces separated by the ripa are
always unlike, the one being entoccelian and the other ectoccelian.

§ 1314. Rostrum (az.), rm.—Fig. 117; Pl. Il, Fig. 4; Pl. IV, Fig. 17. Gray, A, 623;
Quain, A, IT, 538.

The tip of the genu of the callosum. It is shorter in the cat than in man, and some-
times less extensive in man than is commonly figured. Fs ‘

§ 1315. Septum lucidum (cerebri), (az.), Spt. lu.—Fig. 113.

Syn.—Septum pellucidum, speculum, mediastinum 8. diaphragma ventriculorum later-
alium.

This consists of two lateral halves, the hemisepta. Each hemiseptum is so much of
the mesa] wall of the proccelia as is intercepted by the callosum and the fornix when the
two apposed surfaces of thé hemispheres are united. In man, although a space, the pseu-
docelia, remains between them or is formed by absorption, the compound septum so con-
stituted is so thin as to have received the name Jucidum. In the cat and in most other
mammals, the adjective is wholly inapplicable. See hemiseptum (§ 1241) and Area sep-
talis (§ 1203).

§ 1316. Splenium (az), sp.—Fig. 114, 115, 117; Pl. Ul, Fig. 4; Pl. III, Fig. 6; Pl. IV,
Fig. 14,17 ; §§ 1181, 1195, 1238.

The rounded caudal border of the callosum. When the caudal portions of the hemi-
spheres are separated, the splenium appears as a thick white band. Its fibers pass laterad
into the caudal portions of the hemispheres. Its ventral surface is continuous with the
lyra.

The term is in common use, but we have not found it in the works of Gray or Quain.

§ 1317. Stria longitudinalis (callosi), Str. 7ng.—Fig. 115 (?). Gray, A, 624; Quain,
A, IT, 537.
Syn.—Stria Lancisi, nervus Lancisi.

. The human callosum is described as presenting several more or less distinct longitudi-
nallines. We have not satisfactorily observed them upon the fresh brain of either man or
the cat, but presume they are represented by the longitudinal striation vaguely shown in
Fig. 115.

§ 1318. Striatum (Corpus), s.—Fig. 113; Pl. Ill, Fig. 13 ; Pl. IV, Fig. 15,16; §§ 1131
(14), 1149. Gray, A, 625; Quain, A, II, 547, 564.

Syn.—Nucleus caudatus, eminentia lenticularis, ganglion cerebri anterius, apex cruris
medullez oblongate. -

As indicated by the above synonymy, the corpus striatum of the older anatomists
included the entocceelian (“intraventricular”) portion, which appears in the proccelia (PI.
IV, Fig. 16), and the ectocelian (“ extraventricular”) portion, which is commonly de-
scribed as imbedded in the wall of the hemisphere. The former is specified as Nucleus
caudatus and the latter as Wucleus lenticularis. In man, between the two is a mass of

SYNONYMS AND REFERENCES. 489

alba called corona radiata, and between the Nucleus lenticularis and the insula, which lies
ectad of it, is a thin lamina of cinerea, the claustrwm.

The presence and arrangement of these divisions in the cat have not yet sai deter-
mined by us, and we have therefore preferred to use the comprehensive term, striatum.
The student will avoid some confusion if he bears in mind that all of them are portions of
the thickened proccelian parietes.

Spitzka has commented (7, 166) upon the misleading use of the term Nucleus in this
connection ; we suggest that the caudate and lenticular portions of the striatum be known
as (Corpus) cawdatum and (Corpus) lenticulare.

§ 1819. Sulcus habene, S/. A.—Fig. 122; Pl. III, Fig..7; §$ 1148, 1156, 1165.

This name was proposed by the senior author (9, 1386; 14, 538, 544) for the more or
less distinct furrow along the dorso-mesal angle of the thalamus just dorsad of the habena.
It coincides nearly with the line of reflection of the diaccelian endyma toward the oppo-
site side.

§ 1820. Sulcus intercruralis lateralis, S7. ic. /—Fig. 118; Pl. III, Fig. 11.

The Area intercruralis of the cat presents some features which may not exist.in man ~
or may have escaped notice. They are most distinctly visible when the cerebellum is
removed and the “ medulla ” is dorsiducted as in Fig. 118 and Pl. III, Fig. 11.

Caudad of the small (Locus) postperforatus there is a mesal fissure, the Sulcus intercru-
ralis mesalis, and on each side a Sulcus intercruralis lateralis. Between them, of course,
are two ridges.

§ 1321, Sulcus intercruralis mesalis, SI. ic. ms.—See § 1320.

§ 1822. Sulcus limitans, SZ. li.—Fig. 121; PI III, Fig. 18; §§ 1149, 1155.

This name was proposed provisionally by the senior author (9, 137; 24, 588) for the
“depression between the thalamus and the striatum ” (Gray, A, 625; Quain, A, II, 549),
which is obvious and usually mentioned, but has apparently not been named. So long as
both the bodies above mentioned are regarded as parts of the proccelian floor, this furrow
might not require special designation any more than the furrow between the fornix and
the hypocampa. But, in the cat at least, “ this furrow is the line of separation between
the entoccelian surface of the striatum and the ectoccelian surface of the thalamus. A
shorter term is, however, desirable.”

§ 1323. Sulcus triradiatus (az.), S/. trd.—Fig. 118; Pl. III, Fig. 11; § 1169.

This name was proposed by the senior author (14, 554) for the three-pointed shallow
depression which demarcates the albicantia from each other and from the Tuber cinereum.
It is much deeper in the human brain.

§ 13824. Terma (az.), ¢—Fig. 110-112, 117; Pl. I, Mig. 4 4; Pl. IV, Fig: 16. Gray,
A, 620 ; Quain, A, II, 5386.

Syn.—Lamina terminalis s. cinerea,

The thin lamina between the preecommissura and the chiasma and crista, and forming
the cephalic boundary of the caudal portion of the aula.

The name was proposed by the senior author (9, 137; 74, 541) as a brief and signifi-
cant substitute for the cempound terms commonly employed. It is the termination of the
mesal series of coelie, and therefore has considerable morphological significance ; but it is
so delicate as to be sometimes overlooked, and is uenally es dette in the extraction of the
human brain. '

§ 1325. Thalamus, th.—Fig. 110-118, 117, 122, 123; Pl. Il, Fig. 4; Pl. III, Fig. 6, 7,
9, 10,18; Pl. IV, Fig. 16, 18,19; $$ 1148, 1144, 1156, 1157. Gray, A, 629; Quain, A,
II, 535.

ta .5-\> 2

490 ANATOMICAL TECHNOLOGY.

Syn.—Thalamus opticus, thalamus nervi optici, ganglion cerebri posticum, eminentia
magna cerebri.

The thalami form the walls (lateral parietes) of the diaccelia, and are connected by the
medicommissura.

Most of the important features of the thalami are described in the sections referred to ;
there is one, however, which may properly be insisted upon here, inasmuch as it is not
commonly recognized ; viz., its complete exclusion from the procalia in the cat.

In most works upon Descriptive Anatomy, the thalami are mentioned as appearing in
the “ lateral ventricles,” and in Gray (A, Fig. 364) and Quain (A, II, Fig. 388), the surfaces
of the striata and thalami are apparently similar and continuous. Now the fornix (including
the hypocampe and fimbriz) of man is relatively narrower than that of the cat, and it is
quite possible that in the adult, even without the rupture of the membranes at the rima,
a part of the dorsal aspect of the thalamus may appear in the proccelia ; if so, however,
that part of the surface must be covered by the proccelian endyma, and the line of reflec-
tion (ripa) upon the proplexus should be represented. Upon these points our materials
for observation do not enable us to speak more fully. :

But in the cat and dog, we are prepared to state emphatically (§ 1083), that the mar-
gins of the rima are in close apposition, excepting for the intruded elements of the proplexus,
and that in these animals and in other mammals examined by us, no portion of the thala-
mus appears in the proccelia or enters into the formation of its floor; any statements to
the contrary should not be accepted without detailed descriptions and figures.

§ 1326. Tractus opticus, 77. op,—Fig. 116, 118; Pl. I], Fig. 3; Pl. III, Fig. 9, 11;
§ 1144. Gray, A, 6388; Quain, A, II, 533, ;

The subcylindrical fibrous band which arises from the diencephalon, and perhaps from
the mesencephalon, and meets its platetrope cephalad of the Tuber cinereum to form the
chiasma. The larger part of the tract seems to be a direct continuation of the pregenicu-
latum, but we have not traced the fibers in detail. See Chap. XI.

§ 1827. Tractus postrhinalis, Tr. prh.—Fig. 116 ; Pl. I, Fig. 2; Pl. Il, Fig. 3.

This and the following name were proposed by the senior author for the caudal and
cephalic portions of the ventral aspect of the prosencephalon and rhinencephalon, bounded
latero-dorsad by the F. postrhinalis and F. rhinalis respectively. They are of course con-
tinuous with each other.

In the adult human brain these tracts are relatively so small and so obscured by the
overhanging convolutions of the hemisphere proper that they appear not to have been
defined.

Tractus rhinalis, Tr. rh.—See § 1327.

§ 1828. Trapezium, tz.—Fig. 116; Pl. I, Fig. 2; Pl. Il, Fig. 3; $$ 1140, 1161, 1276.
Quain, A, II, 511.

Syn.—Corpus trapezoides—Meynert (Stricker, A, 726); Huxley, A, 64.

The quadrangular, slightly convex portion of the Area postpontilis in the angle formed
by the caudal margin of the pons and the lateral margin of the pyramis. It is sometimes
crossed by a faint cephalo-caudal band, as indicated on the right (left of the figure) side of
Pl. II, Fig. 2. This band seems to be continuous with the Area ovalis, and there is some-
times (as in Prep. 407, M. C. U.) an equally distinct band close to the pyramis and appar-
ently continuous with the Areca elliptica.

Laterad, the trapezium is continuous with the Eminentia auditoria; the N. abducens
arises between it and the pyramis, and the N. facialis between the pons and its latero-
cephalic angle.

In man this area is covered by the greater caudal extension of the pons.

SYNONYMS AND REFERENCES. 491

§ 1829. Tuber cinereum (az.), 7. cin.—Fig. 111, 112, 116-118, 122; Pl. II, Fig. 3, 4;
Pl. Ill, Fig. 5, 9,11; §1074(E). Gray, A, 621; Quain, A, II, 535.

The gray eminence at the cephalic part of the Area cruralis just caudad of the chiasma,
To it is attached the hypophysis by the infundibulum which covers the mesal Foramen
infundibuli. The Tuber cinereum is really continuous with the terma, but the chiasma
forms an ectal interruption.

§$ 1830. Tuberculum Rolando, 7bel. Rol—$ 1190. Gray, A, 618; Quain, A, II, 510.
According to the American Jour. of Neurology, etc. (I, 102), the elevation herein named
Area ovalis is homologous with the Tuberculum Rolando or Tubercolo cinereo.

§ 1331. Valvula (az.), v—Fig. 111-114, 117; Pl. Il, Fig. 4; Pl. III, Fig. 7; §§ 1141,
1165. Gray, A, 631; Quain, A, I, 552.

Syn. —Valvula Vieussenii, vv. cerebelli, vv. Willisiana, yy. magna cerebri, velum
interjectum cerebelli, velum medullare anticum.

The delicate and transparent roof of the longer and cephalic portion of the spool
Cephalad it is continuous with the postoptici, and caudad with the cerebellum just cepha-
lad of the highest part of the epiceelia. Near its cephalic end arise the NN. trochleares.

We have not ascertained whether the valvula is covered by a fold of pia ; apparently
there is between it and the overhanging cerebellum only a little connective tissue. Neither
do we know the precise constitution of the delicate substance of the valvula; it is so thin
that it might well be included with the other tele as the epitela.

§ 1332. Velum (interpositum), (az.), ol.—Fig. 122 ; $$ 1142, 1144, 1156. Gray, A, 628 ;
Quain, A, II, 546.

As has been admitted elsewhere, our knowledge of the velum is incomplete, especially
in respect to its relation with the diatela. As commonly described, and as appears to be
the case in the cat, it is the fold of pia between the dorsal aspect of the mesencephalon
and diencephalon and the ventral aspect of the superincumbent fornix, a part of the pros-
encephalon. Theoretically, and doubtless actually in the embryo mammal, the two layers
of this fold are simply continuous at the line of junction of the prosencephalon with the
diencephalon ; but the growth of the former and its recumbency upon the latter brings
them into contact, and perhaps their distinction is altogether lost.

Primarily, too, the diencephalic layer must have been in contact with the primitive
roof of the diaccelia and entered into the formation of the diatela; but the close approxi-
mation and, perhaps, fusion of the two layers in the adult renders it possible to remove
them together, and the diatela which remains must consist, therefore, of merely the
endyma with the atrophied nervous substance of the roof.

The relations of the velum to the proplexus are referred to in § 1295.

§ 1333. Vermis (cerebelli), (az.), om.—Fig. 114; Pl. 1, Fig. 1,2; PLIV, Fig. 15; § 1200.
Huxley, A, 64.

Syn.—Lobus medius cerebelli.

The name vermis seems to be used in anthropotomy in a restricted sense for a portion
of the median lobe of the cerebellum, but Huxley designates by it the entire lobe.

In the adult cat the vermis is markedly contorted, although regular and symmetrical
in the new-born kitten (Wilder, 11, Pl. I, Fig. 2).

§ 1834. Other Figures of the Brain of the Cat or other Felide.—The following
list, arranged alphabetically according to the names of the authors, includes all the works
and papers known to us to contain figures of feline brains. Additions and corrections
will be thankfully received. The figures represent the cat’s brain unless otherwise
specified.

492 ANATOMICAL TECHNOLOGY.

(1) Bell, T.: A, Fig. 201; the dorsal and dextral aspects of the brain of “ the lion.”
The lateral aspect represents a_brain so distorted as to be unrecognizable; the dorsal
aspect is evidently of a cat’s brain, and, although very imperfect, is copied by Owen, A, Il,
Fig. 83.

(2) Bourgery et Jacob: A, VIII, Pl. 16; Fig. 1, ventral aspect of myelon and its
nerves and of the caudal portion of the brain ; Fig. 2, dorsal aspect of the myelencephalon.
In Fig. 1, some features are obviously incorrect. Both are apparently | original.

(3) Cuvier (Audouin, ete.): B, II, Pl. III, Fig. 6 ; dorsal aspect of the brain of the lion,
reduced. “ Tirée de l’atlas de M. Leuret ” [Leuret et Gratiolet, A].

(4) Dareste: 13, Pl. 2; Fig. 3, lateral aspect of right hemisphere; Fig. 4, dorsal
aspect of hemispheres. Diagtasis, not wholly correct, of the fissures, Sopareptly.
original.

(5) Ferrier: A, Fig, 34, 35; dorsal and lateral aspects, with the “ motor areas ”
marked upon the latter. The figures are original and correct; respecting the eon
tion of the external convolutions, see § 1364.

(6) Flower: 6, Pl. 27; Fig. 12, the mesal aspect of the right hemisphere. Corsectli
represents the mesal fissures excepting part of the hypocampal ; original.

(7) Gall and Spurzheim: A; according to Owen (35, 185), the cat’s brain i is figured
in this work.

(8) Gegenbaur (Lankester): A; Fig. 286, C, represents a partially dissected cat’s
brain ; the figure is evidently SES Ke but vague in some respects.

(9) Gervais, P. : 146 ; there are several figures of feline brains, but the work is not
at present accessible to us, and they cannot be specified.

(10) Hammond, G. M.: 7, Fig. 1; a transection of the left hemisphere through the
striatum. This original figure is intendbd to display certain histological features.

(il) Hitzig: A, Fig. 7; the lateral aspect ; a fissural diagram.

(12) Jones, T. R.: A, Fig. 414; the ventral aspect of the lion’s brain. Reduced
nearly one half, and reversed, from Tiedemann, A, Pl. III, Fig. 4; unacknowledged.

_{18), Leuret (Leuret et Gratiolet, A, Pl. V): dorsal and lateral aspects of the brain of a
lion and lateral aspect of that of a panther. Fig. 1-3, dorsal, mesal and lateral aspects of
the cat’s brain. All are obviously original and very correct, excepting some of the struc-
tural features of Fig. 2, especially the relations of the fornix and callosum.

(14) Lussana e Lemoigne: A; Fig. 123-125, the mesal aspect of the left hemi-
sphere, with two schematic diagrams ; Fig. 126-131, the dorsal, ventral and lateral aspects
of the hemispheres, actual and schematic ; Fig. 182-185, the ventral, mesal, dorsal and
lateral aspects of the hemispheresiaf a- leopard._. , ; |

(15) Marshall, J. :. A, Fig. 2;, dorsal aspect ; poor.

(16) Meynert, T.: 2; Fig. 8, 17, dorsal and lateral aspects of the hemispheres of a
lion ; Fig. 16, lateral aspect of the hemisphere of a wild-cat ; Fig. 28, the lateral Laspert of
a lion’s hemisphere. The figures are original, clear and correct.

(17) Mivart: B, Fig. 125, 126, 129: the lateral, dorsal and mésal aspects. ~ These
figures are unacknowledged, but evidently copied from Leuret, Pl. V, Fig. 1-3 ; the inac-
curate representation of the pseudoécelia is exaggerated.

Fig. 127 is an apparently original representation of a preparation made by tilting the
cerebellum caudad and the hemispheres céphalad, as in Fig. 114 of this work, so ‘as to
expose the optici, thalami, etc. A very erroneous impression is given by the exposure of
the striata and the introduction of a tubular and wholly imaginary pseudoccelia.

Fig. 128, the ventral aspect of what purports to be the brain of a cat ; aside, however,
from the general outline and the exposure of the trapezium, it might be the brain of a
monkey, and some of its features have never been observed in the cat.

ae “Ve

OTHER FIGURES OF THE BRAIN. 493

(18) Owen: 25, Pl. 20; Fig. 1-3, dorsal, lateral and mesal aspect of the brain of the
Cheetah Felis jubata, shaded ; Fig. 4°6, the same of the cat, outline. The former are
somewhat vague, especially as to the Sylvian fissure; the latter are clear, and correct
excepting the non-extension of the /. postrhinalis in Fig. 5, and the indication upon Fig. 6
of an improbable fissure near the caudal end of the hemisphere.

(19) Owen: A, III; Fig. 88, dorsal aspect of cat’s brain. Unacknowledged, but evi-
dently copied from the very poor figure of Bell (A).

(20) Owen: A, III; Fig. 86, the mesal aspect of the right hemisphere ; apparently
original. A good outline diagram, excepting the presence of the line marked (13), pur-
porting to represent the /. Jambdoidalis, and apparently the same as shown in Fig. 3 and 6,
Whether or not such a fissure exists in the Cheetah, or whether, if present in any feline
brain, it is the homologue of the “ lambdoidal ” or “‘ occipito-parietal ” fissure, need not be
discussed here ; but among the many (over 200) cat’s brains examined by us, none have
presented any fissure in that region. Probably the line was accidentally introduced or
may represent a vascular furrow (§ 1341).

(21) Owen: A, II; Fig. 91, the lateral aspect; an outline diagram, apparently
reduced and slightly changed from the same author’s Fig. 5 (25, Pl. 20). The swperorbi-
talis, however, has disappeared, and the diagonalis is made, incorrectly, to join the rhinalis.

' (22) Pansch: 1, Taf. XIV, XV ; Fig. 23-38, dorsal, lateral and mesal aspects of the
hemispheres of adult, new-born and foetal cats. These are excellent original diagrams of
the fissures.

(28) Serres: A, Pl. XIV; Fig. 264, 265, the lateral and dorsal aspects of what pur-.
ports to be the brain of a lion, but, as remarked by Leuret (Leuret et Gratiolet, A, Pl. 5,
p. 10), is really that of a cat.

(24) Spurzheim: A, Pl. IV ; Fig. 5, dorsal aspect of a somewhat distorted brain.

(25) Stowell, T. B.: Z; Fig. 1, 2, ventral and lateral aspects of the cat’s brain, with
special reference to the ectal origins of the cranial nerves ; the fissures and other parts
are shown diagrammatically ; Fig. 3-12, ectal nerve origins and distribution of the vagus.

(26) Tiedemann, F.: A, Tab. III; Fig. 3-5, dorsal, ventral and mesal aspects of a
lion’s brain ; original and mainly accurate ; Fig. 6, the brain ‘‘ Felis nondum adulti, quod
cerebro Leonis persimile est.” Unless the author had positive knowledge as to the imma-
turity of this brain, it must be regarded as that of an adult domestic cat.

(27) Wilder: 11; PI. I, Fig. 1, 2, portions of the cerebellum, showing the vermis
and the Lobulus appendicularis; P|. III, Fig. 15,17, dorsal and lateral aspects of the
hemispheres, diagrams of the fissures; Pl. IV, Fig. 18, 19, lateral aspect, young Asiatic
and African lions, fissural diagrams.

(28) Wilder: 8; Fig. 1, 2, fissural diagrams of the lateral and mesal aspects.

(29) Wilder: 14; Pl. 1-3, Fig. 1-5, the dorsal, lateral, ventral, mesal, cephalic and
caudal aspects of the entire brain or of the hemispheres ; Pl. 3, 4, Fig. 7-20, sections and
dissections illustrating the gross anatomy.

THE CEREBRUM AND ITS FISSURES.

§ 1335. Form of the Cerebrum.—As compared with that of
most dogs, the cat’s cerebrum is remarkable for its width. The
average width is 34-37 mm. With four well preserved adult brains,
taking the width at 100 as the standard, the lengths were respect-
ively 93, 97, 100 and 103, while the heights were 75, 67, 71 and 72.
In round numbers, then, the lateral and longitudinal dimensions of

494 ANATOMICAL TECHNOLOGY.

the combined hemispheres are approximately equal, and the height
is about three fourths as much.

As compared with most dogs, also, the region cephalad of the
cruciate fissure is very short.

THE CEREBRAL FISSURES.

§ 1336. References.—The principal works and papers in which the cerebral fissures are
treated of are named in connection with the synonymy of the F. eruciata (§ 1361).

§ 1837. As was remarked in § 1131 (17, 18), the brain of ‘the cat differs from that of
the Amphibia in that the hemispheres and cerebellum are not only larger in proportion,
but convoluted—the surface presenting depressions ( fisswr@) and intervening folds (gyri).

The cerebellar fissures are numerous and apparently irregular ; and we are not, aware
that their arrangement has been studied in detail.

The cerebral fissures are comparatively few (about 30) and simple, so that it is not
difficult to delineate or describe them as they appear upon a given brain.

§ 1338. The fissures should be studied before the gyri.—Notwithstanding the prob-
ability that the fissures are only the results of the outgrowth constituting the gyri, and
the fact that experiments are made upon the exposed surfaces of the latter, the study of
cerebral topography should begin with the fissures, and they should be identified and
named before the gyri are described and designated. As remarked by the senior author
(11, 219), the “sides of a fissure are usually near together and parallel, so that the fissure
may be described as a single line of certain direction ; but the opposite borders of any one
gyrus are rarely parallel throughout their whole extent. Indeed, it would be as hard to
designate gyri without first identifying fissures as to describe the countries of Europe
without mentioning its rivers.”

Fie. 124, 125.—Dr1aGrams OF THE LATERAL AND MESAL ASPECTS OF THE HEmI-
SPHERES, SHOWING THE FIssuRES; x 1.5.

Fig. 124.—Diagram of the lateral aspect of the left hemisphere, showing the fissures;
x 1.5.

Fig. 125.—Diagram of the mesal aspect of the right hemisphere, showing the fissures.
The diencephalon and the segments caudad of it have been removed as in PI. IV, Fig. 17,
so as to expose the F. hypocampe and the adjacent parts; x 1.5.

On both the figures too little distinction is indicated between the constant and the
inconstant fissures. Upon the Table (p. 496) the former are printed in heavier faced type,
and they are enumerated in § 1366.

STUDY OF THE FISSURES. 495

§ 1839. Study of the Fissures.—The student should make outline drawings of one
or more hemispheres, especially of the lateral aspect. If possible, both hemispheres of
the same brain should be drawn and compared with respect to the amount and character
of lateral variation and compensation (Wilder, 11, 282). The sex should always be
noted, and the age, known or estimated, stated upon the drawing.

The drawings of fissures should be in outline only, and most attention should be given
to the union or independence of fissures which approach each other.

§ 1340. Sometimes it is difficult to distinguish between a true fissure and a depression
in which was lodged a superficial vessel. Such vascular trenches, however, have usually
more abrupt and sharply defined edges than the fissures (Wilder, 11, 221).

The mesal aspect of the hemisphere is largely a plane surface ; but the lateral and
other aspects present difficulties in respect to perspective which are common to convex
surfaces. Where a hemisphere is very peculiar, the drawings should be based upon pho-
tographs. The method of drawing fissures described by the senior author in 1873 (11,
219), in which the perspective was ignored, is no longer recommended by him.

§ 1341. Indicating the Relative Depth of Fissures—As appears in Fig. 122, and in PI.
III, Fig. 18, and Pl. IV, Fig. 15, the fissures vary considerably in depth. They also vary
in different parts of their course, being usually deepest near the middle of their length.
Where a fissure is wholly superficial, it may be represented by a shading; but otherwise
a line must be employed, the width of which may indicate the depth of the fissure in dif-
ferent parts of its extent and as compared with other fissures. The depth may be ascer.
tained by carefully “ sounding” with a graduated, thin, smooth and rounded rule, or by
sections of the brain after the location, extent and connection of the fissures have been
indicated by lines of uniform width.

§ 1342. Table of the Cerebral Fissures.—The accompanying Table (p. 496) includes
an alphabetical list of the feline cerebral fissures, with the abbreviations employed in
this work, and the principal synonyms.

The constant fissures are printed in black letter.

The synonymy is limited to writers who have made special additions to the technical
nomenclature, and excludes those who have employed phrases or vernacular names, or
who have used the names of other writers in purely physiological papers.

§ 1348: Sources of the Names.—The following brief statement respecting the names is
quoted from the senior author’s paper (8, 50) :—

“Owen's ‘ postsylvian’ should not be displaced by Krueg’s ‘ suprasylvii posterior,’ nor
his ‘marginal’ by ‘ suprasplenialis’ Likewise, Flower’s ‘ supraorbital’ has priority over
my ‘ presylvian,’ which Krueg has adopted [and is free from the implication of a doubt-
ful homology].

“On the other hand, Krueg’s ‘ anterior’ and ‘ postica’ are so much more usable than
previous names as to be worthy of acceptance, especially as they may be regarded as
abbreviations of the phrases by which the fissures in question were designated by Owen
and myself. ‘ Splenialis’ is to be preferred to supercallosal or calloso-marginalis, so long
as the human homologue of the fissure is uncertain. If marginalis is to be retained, post-
marginalis will be better than ‘ postsplenialis.’

“‘T am particularly gratified to find that Krueg admits as fissural integers the ansata
and the diagonalis ; the former I had intended to call transversa and the latter intermedia,
but Krueg’s names must be retained. We agree also in regarding Owen’s ‘ medilateral’
as composed of two fissures, which Krueg terms medilateral and confinis. I had intended
to leave Owen’s name attached to the fissure which is really mesad of the lateralis and to
call the [caudal] curved division /wnata ; the name lunata has now been given to what
otherwise would have been sublunata. I have applied the name intermedia to a fissure
which Krueg mentions but does not name,”

ANATOMICAL TECHNOLOGY.

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FORMATION OF FISSURES. 497

§ 1344. Problems Connected with the Cerebral Fissures.—
The study of the fissures of a single brain is comparatively uninter-
esting and unprofitable unless three general questions are consid-
ered :—

(1) Whai relations do the fissures bear to the ental structures?
(2) What is the fissural pattern in the cat?
(3) How do the fissures of the cat compare with those of man and other mammals ?

§ 1345. Formation of Fissures.—At birth the cat’s hemispheres present fewer and
shallower fissures than in the adult. Presumably they were entirely smooth at an earlier
period, as is the case in all other mammals which have been examined.

The hypocampal fissure represents an involution of the entire thickness of the parietes,
the hypocampa (§ 1243) being the reverse elevation. The callosal fissure, and perhaps
some of the others already enumerated (§ 1343), are formed in some peculiar way.

So far as the other and ordinary fissures are concerned, although sometimes described
as depressions, it is probable that they are to be regarded as lines of less elevation as com-
pared with the intervening folds. More extended and accurate observations are needed
upon this matter. For the formation of the cruciate fissure, see § 1359.

§ 1346. Structural Relations of Certain Fissures.—So far as appears from sections
of the cat’s brain at any period after birth, only eight of the cerebral fissures have any
intimate or constant relation to structural features, viz., the callosal, fimbrial, hypocampal,
olfactoria, postradical, preradical, rhinalis and postrhinalis. These have all been men-
tioned in connection with the parts with which they appear to be correlated.

§ 1347. In man two other fissures, which do not exist in the cat, are related to eatal
structures : the calcarine to the calcar (§ 1194) and the collateral to the Hminentia collat-
eralis at the place of departure of the postcornu from the medicornu.

A few of the fissures will now be mentioned separately.

_§ 1348. F. callosalis, F cl., the callosal fissure.—Fig. 117, 122, 125; Pl. Il, Fig. 3;
Pl. Ill, Fig. 18; Pl. IV, Fig. 17, 20.

This coincides with the dorsal border of the callosum, curves about the splenium to
join the hypocampal (Fig. 125) and about the genu to be continuous with the /. preradi-
calis when the latter is distinct.

§ 1349. F. fimbriz, F. fmb., the fimbrial fissure—Fig. 121, 125; Pl. IV, Fig. 14, 17;
§ 1172.

A distinct and apparently constant depressed line between the fasciola and the fimbria,
thus coinciding with the margin of the cinerea. It is not a true cortical fissure, and
perhaps should not be enumerated with the rest.

§ 1350. F. hypocampe, F. hmp., hypocampal fissure —Fig. 121, 125; Pl. IV, Fig. 14,
17; § 1172.

Syn.—F. hippocampi, hippocampal fissure.

This is not the deepest of the cerebral fissures, but it is one of the longest, and is per-
haps the most constant of all among the Mammalia, being present when the hemispheres
are otherwise smooth or indented only by the rhinalis and postrhinalis.

It extends from near the tip of the Lobulus hypocampe to the splenium, where it is
continuous with the F. callosalis. In the larger part of its course it presents a decided
caudal convexity, forming nearly the half of a circle and coinciding in general with the
medicornu and with the hypocampa, of which it is the depression in reverse. Near the

32

498 ANATOMICAL TECHNOLOGY.

splenium, however, it presents a short and quite sharp cephalic convexity. The cinerca
cephalad of the F. hypocampe constitutes the fasciola.

§ 1351. F. Sylviana, 7 S., the Sylvian fissure—Fig. 124; Pl. I, Fig. 2; Pl. Il,
Fig. 3; Pl. IU, Fig. 5; § 1163.

Syn.—Fissura Sylvii ; the “ posterior” or longer branch of the human F, Sylvii.

By common consent, this short and distinct fissure of the cat and dog is called by the
name originally applied to the much more extensive and complex human fissure. To dis-
cuss the homology would occupy undue space. The chief questions are (1) as to the rep-
resentation of the insula (§ 1247), which in man is concealed between the dorso-cephalic
and the ventro-caudal lips of the fissure ; and (2) as to the correspondence of the relatively
extensive region between the F. Sylviana and the F. superorbitalis with the human oper-
culum ; Meynert, 7, Fig. 16; Wilder, 11, 225, and 74, 551. i*

§ 1352. The statement (11, 223) of the senior author as to the presence of the Sylvian
fissure in all brains which are fissured at all (quoted in the last two editions of Dalton’s
Physiology, A, 413) referred originally only to the lateral fissures, and may not be correct
with even that qualification, for the rhinalis and postrhinalis seem to occur in some mam.
mals when the Sylvian is either absent or very indistinct.

§ 1353. Fissura ansata, 7. an.—Fig. 24: Pl. I, Fig. 1, 2.

This fissure is peculiar and presents some difficulties. Most commonly it seems to
form simply a conjunction between the lateralis and the coronalis, with a branch pointing
meso-cephalad. Less frequently is it independent of the coronal, asin Pl. I, Fig. 2, and
the left side of Fig. 1; most rarely is it wholly isolated as a simple diagonal fissure, as in
Fig. 24 and the right of Pl. I, Fig. 1. Nevertheless, Krueg and the senior author came
independently to the conclusion that this is the primitive condition of the fissure and the
one to be represented upon a diagram.

§ 1354. Fissura anterior, 7. a.—Fig. 24; Pl. I, Fig. 1, 2; Pl. III, Fig. 5.

The disconnection of the dorsal end of this fissure from that of the postica, so that the
keystone of the first arch is absent, constitutes a constant distinction between all the
Felide and the feral Canide and most domestic dogs. The two fissures sometimes
approach quite closely and even overlap, but we have never observed a junction. On the
other hand, while the two form a continuous fissure in all feral Canide# and most domesti-
cated dogs, in the latter the arch is sometimes broken, giving this region of the brain a
feline aspect (Wilder, 11, 229, and Fig. 13, 16). In this as in other respects, the dog dis-
plays more variability than the cat.

§ 1355. Fissura cruciata, F. er.—Fig. 117, 124, 125; Pl. I, Fig. 1, 2; PI. Il, Fig. 4;
Pl. Il, Fig. 5; Pl. IV, Fig. 16-19,

§ 1356. Constant and Peculiar Characters.—Indents the dorso-mesal margin of the
hemisphere near its cephalic end, so as to appear upon both the dorsal and mesal aspects.
Length of the dorsal and mesal portions approximately equal. Dorsal portion at a right
angle with the meson. Line formed by the dorsal portions of the two fissures about one
half the length of the line representing the F. interhemispheralis, with which it forms a
Roman cross. Lateral end simple and independent.

§ 1357. Variable Characters——Caudal end of mesal part of fissure usually dorsad of
the junction of the cephalic and middle thirds of the callosum, and about two fifths of the
distance from the callosum to the dorsal margin of the hemisphere, thus about midway
between the callosum and the cephalic end of the F. splenialis. Rarely are these two
fissures continuous.

§ 1358. The dorsal part of this fissure is a marked feature of the dorsal and cephalic
aspects of the hemisphere, on account of its straightness, simplicity and independence, and

THE CRUCIATE FISSURE. 499.

its relation to the 7. interhemispheralis. Its symmetry is also remarkable; very rarely is
the mesal end on one side farther caudad than on the other.

The mesal portion is less uniform. The caudal half often tends slightly dorsad and
the end is sometimes forked. Rarely does the caudal end join the / splenialis. Accord-
ing to Krueg (2, 620), the union was observed once by Guillot (A, Fig. 172); Krueg him-
self has seen it only twice (2, 620), and Pansch (2, 21, Fig. 27) three times out of fourteen.
Out of about 400 hemispheres of adult cats dissected by us or our students or preserved
in the Museum of Cornell University and in the Museum of Comparative Zoology, it
was noticed in only 4.

In view of Broca’s idea (1) that the eruciata and splentalis are morphologically parts of |
a single fissural integer, their relations should be carefully examined; note should be
taken as to whether a junction is effected by means of branches or by a deflection of one
or both of the fissures themselves ; whether the combined fissure is shallower at the place
of junction, and whether the junction exists upon both hemispheres.

This fissure is also interesting on account of the various opinions which have been
expressed as to its human homologue (see § 1370), and because several well-marked
“motor centers” have been found about its dorsal portion ; apparently none have been
discovered upon the mesal surface of the hemisphere.

§ 1359. Formation.—As intimated by the senior author (11, 226), and more distinctly
shown by Pansch (J, Fig. 32) and Krueg (2, Taf. XXXIV), the F. cruciata really begins
upon the mesal aspect of the hemisphere, as a shallow depression which gradually ap-
proaches the margin, indents it, and finally extends laterad for a distance equal to or
greater than its mesal part. Upon a series of kitten’s brains, from a week before birth
to a week after, the formation of this fissure is beautifully illustrated.

§ 1360. The Name.—Owen’s “‘ frontal” is descriptively significant, but it implies a not
yet proven homology with one of the human frontal fissures, and is antedated by Leuret’s
“ crucial.” As to the technical form, there seems little to choose between crucialis and
eruciata. Personally we prefer the former, but Krueg has employed the latter, and his
name is here adopted.

§ 1361. Synonymy.—The following synonymy is chronological, and intended to include
all the works and papers in which the cruciate fissure is mentioned. It forms part of an
unpublished paper by the senior author which is mentioned in 8, 49, and 74, 524.

Cuvier (1805) ; ‘‘ en avant, un sillon court qui la traverse en croix ;”’ Carnivora; C,
II, 157.

Owen (1833) ; ‘a transverse anfractuosity—the transverse anfractuosity—the first trans-
verse fissure ;” cat, cheetah; 35, 133, 184; Pl. XX, “ 7.”

Owen (1835) ; “ the anterior transverse anfractuosity ;” Cercoleptes (kinkajou); 53,
122.

Leuret (18389) ; “‘ sillon crucial ;” cat and the Carnivora generally ; Leuret et Gratio-
let, A, I, 379, etc., Pl. V, Fig. 3, opposite “ a.”

Cuvier, Dumeril, etc. (1845) ; ‘‘ sil/on crucial ;” Felide and most other Carnivora ;
Cuvier, B, III, 93.

Dareste (1855); “ sillon crucial ;” cat and several other Carnivora; 1.3, 110, Pl. II,
Fig. 1, 2, 4, 8, ““f.”

Owen (1868) ; “the frontal fissure ;” cat and the “ Gyrencephala” generally ; A, III,
116-136, Fig. 91, etc., “ 14.”

Flower (1869) ; ‘‘ crucial sulcus, crucial fissure ;” Proteles cristata and the Carnivora
generally ; 28, 479, 482, Fig. 1, 2, 4, “¢.”

500 ANATOMICAL TECHNOLOGY.

Flower (1870) ; ‘crucial sulcus ;” Ailurus fulgens ; 35, 755, Fig. 1, 2, 8, “¢.”

Lussana e Lemoigne (1871) ; ‘‘ scisswra crociata ;” cat and many other mammals ;
A, I, 142, Fig. 127, 191. ;

Fritsch und Hitzig (1870); “frontal fissure ;” dog; 1, 312.

Gervais (1870) ; cephalic part of “‘ sillon crucial ;”” most Carnivora ; 146, 105.

Huxley (1870) ; “ crucial suleus—anterior end of the calloso-marginalis ;” dog; A, 420.

Hitzig (1873) ; ‘‘ frontal fissure ;” dog; 4, 434, Fig. 1, 2, 3, “ 14.”

Wilder (1873) ; “ frontal fissure ;” cat and the Carnivora generally ; 11, 225, Fig. 15,
Rp Oe “I.”

Hitzig (1874) ; “‘ sulews eruciatus—frontal fisswre—fissura frontalis ;” cat and dog;
A, 18, 46, 96, 129, Fig. 1,7, “ 14” or ‘*8. ©.”

Garner (1876) ; ‘‘ transverse or crucial sulcus ;” 1, 153.

Ferrier (1876) ; ‘‘ crucial sulcus ;” cat, dog ; A, 145-154, Fig. 82-35, “‘b.”

Meynert (1877) ; “ der Leuwret’schen querfurche—der vordere aufsteigende ast der rand-
furche ;” wild-cat, etc.; 1, 12, Fig. 17, ete., ‘ cm.-call. m.”

Huguenin (Duval et Keller), (1878) ; ‘‘ swleus cruciatus ;” dog, fox, etc.; A, 55, 56,
Fig. 40, 41, “ sc.”

Broca (1878) ; 1; (this reference has been mislaid, and the paper is not now accessible
to us).

Foster and Langley (1878) ; “crucial fissure ;” dog; A, 219.

Krueg (1878) ; “ sulews cruciatus ;” dog and Carnivora generally ; 7, 335, 345, Taf.
4 a had

Horsley (1879); ‘‘ fisswra cruciata ;” Carnivora; 7, 277.

Clevenger (1879) ; ‘* carntvoral crucial sulcus ;” Carnivora ; 1, 7.

Pansch (1879); ‘‘ das vordere ende der mediale hauptfurche ;” cat and Carnivora gen-
erally ; 7, 21, etc., Fig. 26, 32, 48, etc., “‘m. Af.”

Krueg (1880) ; ‘‘ fissura cruciata ;” most Carnivora, 2, 610, Taf. XXXIV, XXXVII,
ore

Wilder (1880) ; ‘‘ fissura eruciata ;” 8, 50, Fig. 1, 2.

Mivart (1881) ; “crucial sulcus ;” B, 259 and 261, Fig. 125 and 126, ‘‘¢.”

Wilder (1881) ; “ fissura cruciata ;” cat; 14, 584; Pl. I, Fig. 1, 2; Pl. II, Fig. 4;
Pl. Il, Fig. 5; Pl. IV, Fig. 16-19, “ F. er.”

§ 1362. Designation of the Gyri.— The Sigmoid Gyrus.—This
name has been used, especially by English writers, to designate
the approximately s-shaped fold which curves about the lateral end
of the cruciate fissure (Pl. I, Fig. 1). Its surface includes several
quite constant and well-marked ‘‘ motor areas”’ (Ferrier, A, Fig. 32;
Dalton, A, Fig. 113, 114).

§ 1363. The External or Arched Gyri.—The four arched gyri which are so regularly
arranged in the fox and wolf were enumerated by Leuret (Leuret et Gratiolet, A, I, 374;
Atlas, 9), beginning with that which immediately borders the Sylvian fissure, and ending
with that which forms the margin of the hemisphere.

Since the fissure is constant and the margin variable, this would seem to be a natural
arrangement, and it has been adopted by Huguenin and some others. As appears, how-
ever, from the accompanying Table, several writers have modified it or reversed the order
altogether. Such transpositions are troublesome enough for skilled anatomists, and can
hardly fail to perplex the beginner.

THE FISSURAL PATTERN. ~ 501

TABLE SHOWING Four METHODS OF ENUMERATING THE “ ARCHED GYRI.”’

Leuret
Loc (Leuret et | Ferrier, A,|Flower, 28,| Mivart, B,
eK: Gratiolet),| 145. 479. 259.
, 380.
Next the mesal border of the hemisphere...... Fourth..| First....| Third....| Superior.

Between the F. Jateralis and the supernyet : -
Ana and postsylViand........esseceeeceeree t Third... .| Second...| Second.. .} Middle.

Between the F. supersylviana and the an-

terior and postica..... ov o's: 6/s:0l er ahd ara ontaretera Becond:. . Third...
First. . .| Inferior.
Between the F. anterior and postica and the :
My AOS oo Ka ncn du 3 01d dv sap mealeeedaion Beers | Vest <>

§ 1364. The Angular Gyrus.—This name is applied to a fold of the hemisphere in
man and monkeys. By a few writers it has been given also to the caudal portion of what
Leuret called the third arched convolution. As indicated below (§ 1369), we do not think
the homologies of the fissures or folds are sufficiently well determined to warrant the
application of this name to the Carnivora.

§ 1365. The Fissural Pattern.—The fissures of the cat, dog and fox can be homolo-
gized in most respects, yet they differ to such an extent as to be readily distinguishable.
If we could accurately determine the arrangement of fissures which is common to all
domestic cats and peculiar to them, we might be able to define the fissural pattern of the
species. !

In view of the inadequacy of our knowledge, we have thought best to confine the dis-
cussion of the fissural pattern to a brief statement of what appear to be the constant and
the inconstant fissural characters of Felis domestica.

§ 1366. Constant Characters.—(1) Presence of the following nineteen fissures : anterior,
ansata, callosalis, coronalis, cruciata, diagonalis, fimbria, hypocampe, lateralis, marginalis,
olfactoria, postica, postrhinalis, postsylviana, rhinalis, Sylviana, splenialis, superorbitalis,
supersylviana.

(2) Fissura Sylviana rather short, forming not more than one third nor less than one
eighth of an imaginary line coinciding therewith and extending from its ventral end to
the dorsal margin of the hemisphere.

(8) Nine fissures are so placed with reference to the Sylvian as to form three irregular
arches dorsad of the Sylvian, corresponding with the more regular arched fissures of the
fox and wolf; the first consists of the postica and the anterior, the diagonalis often being
continuous with the latter ; the second, of the postsylviana and supersylviana ; the third,
of the lateralis, with the medilateralis when present, the ansata and coronailis.

(4) Absence of a fissure (7. ectolateralis of Canidee) between the caudal portions of the
lateralis and the supersylvian.

(5) Disconnection of the dorsal ends of the anterior and postica.

(6) Independence of the /. olfactoria.

(7) Independence of the dorsal ends of the anterior, postica, superorbitalis and Sylviana ;
of the ventral ends of the hypocampe, coronalis and medilateralis ; of the caudal ends of
the splenialis and postradicalis (when present); of the lateral end of the cruciata ; of the
mesal end of the ansata. }

502 ANATOMICAL TECHNOLOGY.

(8) Continuity of the rhinalis with the postrhinalis ; of the Sylvian with the point of
their junction ; of the superorbital with the rhinalis ; of the callosal with the hypocampal,
and with the preradicalis when present.

§ 1867. Variable Characters.—(1) More or less frequent presence of the following ten
inconstant fissures : confinis, falcialis, intermedia, lunata, medilateralis, posteruciata, post-
marginulis, postradicalis, preradicalis, subfalcialis,

(2) Frequent union of the ansata with the coronalis and lateralis ; of the lateralis with
the ansata and medilateralis ; of the diagonalis with the anterior ; of the supersylvian
and postica ; of the marginalis with the postmarginalis.

(8) Occasional unions of the medilateralis and confinis ; of the crutiata and the sple-
nialis.

(4) Very rare unions of the postica and the rhinalis ; of the anterior with the super-
sylvian.

§ 1368. Homology of the Human and Feline Fissures.—The determination of the
identity of the human fissures with those of the other Mammalia has long been desired from
the standpoint of Comparative Morphology and Systematic Zoology. Referring in 1868 to
his Lectures on the Brain in 1842, Owen says (A, III, 116): “ The main object which I
had in view was the determination of the homologous and superadded convolutions in the
more complex prosencephalon of man.”

Since the discovery in 1870 by Fritsch and Hitzig (1) of the electrical excitability of
certain areas of the cerebral cortex in the dog and cat, and the confirmation of this upon
monkeys by Ferrier (A, 138), there have been likewise physiological and psychological
reasons for the determination of these fissural homologies, and at this time probably few
biological events would be more generally welcomed than the presentation of incontro-
vertible evidence as to the human homologue of the carnivoral Fissura cruciata, or the
representative of the human centralis (Fissure of Rolando) in the cat and dog.

§ 1369. The following are sufficient general examples of the difficulties which sur-
round the subject and of the differences of opinion among high authorities -—

Gratiolet wrote (A, 10) :—

“ We need only compare the brain of an ape with that of a carnivore or a ruminant to
see that the convolutions present very dissimilar general arrangements in the several
orders of Mammalia. These differences are so great that it would be imprudent to estab-
lish corresponding subdivisions and to investigate their homologies. In fact, this ques-
tion has as yet no basis of certainty, and we think that for the present it should not be
undertaken.”

Owen says (25) that the same names apply to the fissures of the Aye-aye and the cat,
while the very next paper in the volume of the Zoological Transactions contains the
admission of Flower (6) that, as between the Lemurs and the Carnivora, the “ nomencla-
ture utterly fails.”

$ 1370. Special examples of the diversity of opinion are furnished by the two fissures
already named, the eruciata or “ frontal ” of the cat and dog and the centralis of man.

The centralis is homologized with the swperorbitalis by Duval and Keller (A, 57, note),
and apparently by Broca; Hitzig (A, 136, 137, Fig. 10,11) makes it equivalent to the
ansata together with a part of the supersylviana, a view which derives some support from
the occasional interruption of the human centralis ; it is the homologue of the coronalis
in the opinion of Owen (A, III, 130), Meynert (7), and Pansch (7, 47). In an earlier
paper, however, Pansch regarded the centralis as homologous with the eruciata, and
this is the opinion of Ferrier and Clevenger.

The cruciate fissure of the Carnivora is said by Ferrier (A, 199) to be experimentally
the equivalent of the centralis, and Clevenger (2, 14) states that the two fissures are “ his-

HOMOLOGY OF HUMAN AND FELINE FISSURES. 503

tologically as well as physiologically analogous,” although in a previous paper (7, 24) he
had declared that “ anatomically, the crucial and Rolandic are not capable of comparison ;”
Lussana and Lemoigne (A, Fig. 75) make the cruciata equivalent to the calloso-marginalis
of man, while Duval and Keller (Huguenin, A, 57, note) consider it as ‘‘ l’analogue du sil-
lon perpendiculaire externe ou sillon occipital de ’homme ;” Broca (Z, 407) is sure that
the cruciata-is not the representative of the centralis, and its existence with the Primates
is denied altogether by Hitzig (A, 430) and Meynert (2, 659, note).

After having followed up all the clues at our disposal, and spent upon this single mat-
ter more time than we supposed would be required for the elucidation of the gross anat-
omy of the entire brain, we are forced to admit our inability to satisfy ourselves completely
with respect to the homology of the carnivoral fissures with those of man, excepting of
course the hypocampal and callosal, which have never presented any difficulty on account
of their relation to structural features ; as to the existence of a “ lambdoidal” or ‘‘ occipi-
to-parietal ” fissure in the cat, see § 1334 (20).

So long, indeed, as any doubt exists with regard to the correspondence of the fissures
of the cat, seal and raccoon, and of man, Macacus and Lemur, it is hardly to be expected
that the homology between the members of the two groups should be altogether clear.

§ 1371. The following lines of inquiry seem likely to be most productive of results :—

(1) Numerous and careful preparations and drawings should be made of the brains of
all Carnivora and monkeys, especially of the young. The same should be done for pecu-
liar foetal and adult human brains.

(2) Between the ordinary Carnivora and the monkeys are two groups whose brains
should be studied with especial care : the seals have a rudimentary postcornu and occipital
lobe, and these parts are said to be well developed in the Lemurs, which have affinities
with both the Carnivora and the Primates.

Respecting the brains of the lower Vertebrates, see Appendix, § 1455.
/

CHAPTER XI.

THE CRANIAL NERVES AND ORGANS OF SENSE.

GENERAL CONSIDERATIONS—CLASSIFICATION OF THE CRANIAL NERVES—TABLE OF THE
CRANIAL NERVES—SKIN—TONGUE—NOSE—-EYE AND ITS APPENDAGES —EAR.

§ 1372. The Cranial Nerves—General Considerations.—As
briefly described in §§ 996, 1007, and shown in Fig. 104, 109, most
of the nerves of the trunk and limbs are connected with the myelon
by two sets of roots which respectively emerge from its dorso-lateral
and ventro-lateral aspects opposite the dorsal and ventral cornua of
the cinerea. The dorsal roots bear each a ganglion, and they are
sensory, while the ventral have no ganglion (Fig. 109) and are
motor.

Each dorsal root is joined by a corresponding ventral root, and
the trunk so formed has both motor and sensory functions.

The roots and trunks vary in size and in the number of their
rootlets and branches ; they vary also to some extent in their rela-
tions with the sympathic nerves and the viscera. Upon the whole,
‘ however, they form a series all the members of which are readily
and quite closely comparable.

§ 1373. But the cranial nerves (which either arise from the
encephalon or eventually escape through cranial foramina) present
no such simplicity in any animals, and in man and most mammals
their irregularities in origin and distribution are so great that the
older anatomists seem not to have attempted any comparison with
the myelonal type. Their functions likewise were imperfectly
known, and they were therefore numbered in order, beginning at
the cephalic end of the brain, and their names referred mainly to
their anatomical connections.

THE CRANIAL NERVES. 505

§ 1374. TABLE OF THE SYNONYMS OF THE CRANIAL NERVES.

Sémmering. Technical names herein adopted. Synonyms. Willis.
tear Olfactoril....<. anise. cxcces see Rhinencephalici................... zr.
Lt eae yg CLT: Sa eg 2 bere a) BPC eee Cree Es Tu a eRe Ege Il.
Ill ;| Ocubomotoriuss. yn 2 ales cess ess Motor oculi communis............. iL.
IV ‘Prochlearis.:. ..csvsanesasee =e sa Pathetionss <0. <3i ee tersbanes yen IV
V Fx aathierpte TeigemiAus: 5. .s1.eanse'ecsleres s4 TRMACIBHB... 02 dsc gceinddechewethaes MS
Wan ehcss 4a) RLUCEDS. «0 <cn dh ee ae ane al ikiniamig is dis'b sop 0s as ic MME awe S NE
a ee PPACIDG.. «. o «ow St eemieeee pe aees OYGlG QUES co cio xs, cisjacnie a e's sateen VIL
Vill... 6 0< Auditorius..... 0665 sesccseeees Portio mollis, Acusticus......... t
Te. cate Pana T CUS h vick de 4 So hig 8 al ee go fh gOS She de hoe. “ae dee
eee ns, cana 's | VERB a 5th ow sone ein enna nc -| Par vagum, pneumogastricus.... Vill
pt Pres ACCOSSOTIOB ar 25s Wisco ac eie a ies Accessorius spinalis.............
XI By poglorantt << cit came eiabo all tia oh veux $5554 <4 = cop nec casivets IX

§ 1375. Designation of the Cranial Nerves by Numbers.—
Among the older anatomists (as may be seen from Vicq d’ Azyr, A,
‘¢ Explication,” 48-50), the cranial nerves were variously enume-
rated. At the present day only two methods are commonly em-
ployed, those of S6mmering and Willis. As indicated upon the
accompanying Table, the difference between these two concerns only
half of the twelve. The 7th and 8th of SO6mmering constitute the
Portio dura and the Portio mollis of Willis’s 7th; the 9th, 10th
and 11th of Sémmering are included in the 8th of Willis, and the
12th of the former represents the 9th of the latter.

Fortunately, the nerve most often concerned in medicine and
surgery is the 5th, the seat of toothache and most other forms of
facial neuralgia. Upon the whole, it would be better to abandon
the use of the numbers altogether and employ only the technical
names here given, with, perhaps, the substitution of the shorter
word acusticus for auditorius. Nevertheless, in the Descriptions
($$ 1380-1391) and in the Table (p. 520), the numerical order is fol-
lowed for convenience of reference.

§ 1376. Arrangement of the Cranial Nerves.—These nerves
have been variously classified in accordance with physiological or
morphological facts and theories.

The following Table exhibits the provisional physiological
arrangement which was outlined by Wyman (34, 40) and has been
elaborated by Dalton (A, 447).

506

ANATOMICAL TECHNOLOGY.

§ 1877. PROVISIONAL PHYSIOLOGICAL ARRANGEMENT OF THE CRANIAL
(Slightly altered from Dalton, A, 447.)

NERVES.

A. NERVES OF SPECIAL SENSE, LACKING GENERAL SENSIBILITY.

1. Olfactorii.

2. Opticus.

3. Auditorius.

B. Moror AND SENSORY NERVES COMPARABLE WITH MYELONAL NERVES.

Sensory Nerves (with Gan-
glia) = Dorsal Roots of
Myelonal Nerves.

Motor Nerves = Ventral
Roots of Myelonal
Nerves.

General Distribution.

( Oculomotorius. ]
Trigeminus (Radix sensoria). | Trovhlearis. Skin, mucosa and muscles of
Gng. Gasseri. tye wes f face
& | Radix motoria (trigemini). >
| Facialis.
Glossopharyngeus. Hypoglossus. Tongue and pharynx.
Gng. petrosum.
Vagus. Accessorius, Passages of respiration and

Gng. jugulare.

deglutition, ete.

§ 1378. Dalton recognizes two great divisions, the nerves of spe-
cial sense and ordinary motor and sensory nerves. Since some of
the latter also possess special sensibility, the former may perhaps
be characterized as nerves of special sense which lack general
sensibility and have no ganglia.

The other and larger division includes nerves which are anatom-
ically and physiologically distinguishable into two groups, cor-
responding respectively to the dorsal and ventral roots of
myelonal nerves. Three of these bear each a ganglion, like that
upon the dorsal root of a myelonal nerve, and are, at their origin,
exclusively sensitive. The others apparently lack ganglia and are
functionally motor.

But while the foregoing Arrangement is at least convenient and
serves to impress upon the mind of the student the probability
that, as the ‘‘ medulla”’ is a modification of the myelon, so some at
least of the cranial nerves are modifications of the myelonal type, yet
sight should not be lost of certain ascertained or probable facts of
Embryology and Comparative Anatomy which are not in full accord
therewith.

These facts and considerations are admitted by Wyman and Dal-
ton, and others are presented in the compendiums of Huxley, A, 66-71,

THE CRANIAL NERVES. 507

Gegenbaur (Lankester), A, 515-522, and Balfour, A, IT, 374-383,
and in the papers there cited. See also A. M. Marshall (4).

§ 1379. In the following brief descriptions of the cranial nerves,
only the ectal or superficial or apparent origins are given. Their
ental (real or deep) origins in man are presented briefly in Gray and
Quain, and more fully in Meynert (Stricker, A, 727-751), and in
special papers.

§ 1380. (I) Nervi olfactorii, WV. o/., the olfactory nerves——Fig. 110; § 1160. Gray,
A, 620; Quain, A, I, 526.

The true olfactory nerves of the cat and man are soft fibrous fasciculi which pass from
the surface of the pero through the olfactory foramina of the cribriform plate of the eth-
moid bone (Fig. 60, 88), to be distributed to the nasal mucosa (§ 1398, membrana Schnei-

‘deriana).

On account of the smal] size of the Lobus olfactorius in man, it was formerly regarded
as a nerve, and is still often so called. As shown both by development and by comparison
with the lower animals, it is really a protrusion or lobe of the brain.

§ 1381. (II) Nervus opticus, JV. op., the optic nerve.—Fig. 110, 116, 117; Pl. I,
Fig. 2; Pl. Il, Fig. 3,4; Pl. Ill, Fig.5; Pl. IV, Fig. 16,18,19. Gray, A, 628; Quain,
A, I, 527.

Each optic nerve is a cylindrical white cord springing from the side of the chiasma
(§ 1202) and passing through the optic foramen (Fig. 57, #’m. op.) to the eyeball.

The optic nerves are formed by protrusions of the primitive diencephalon, and are
hence, like the olfactory lobes, regarded by Gegenbaur (Lankester), A, 515, as prolonga-
tions of the brain.

The cavity is obliterated, and in man the fibers constituting the nerve have been
traced not only to the thalami and geniculata, but also to the optici. We have not traced
them carefully in the cat.

§ 1382. (IIL) Nervus oculomotorius, WV. ocm., the oculomotor nerve.—Fig. 116; Pl.
Il, Fig. 3. Gray, A, 640; Quain, A, I, 528.

The trunk of this nerve is cylindrical and about 1 mm. in diameter. It arises, slightly
flattened, from the Area intercruralis, about 2 mm. from the meson and just caudad of the
cimbia (§ 1203), is closely associated with the ophthalmic division of the N. trigeminus,
and emerges therewith by the Fm. lacerum anterius to be distributed to all the muscles
of the eyeball which are not supplied by the trochlearis and abducens ; it goes also to the
levator palpebre dorsalis muscle.

§ 1383. (IV) Nervus trochlearis, WV. tr. the trochlear or patheticus nerve.—Fig. 116 ;
PL I, Fig. 2; Pl. Il, Fig. 3; Pl. Il, Fig. 9. Gray, A, 641; Quain, A, I, 519.

This, the smallest of the cranial nerves, arises from the valvula by three fasciculi.
The trunk is involved in the pia and easily torn away therewith.

It passes laterad and then ventro-cephalad between the cerebellum and the hemi-
sphere, associates itself with the ophthalmic division of the trigeminus, and emerges
therewith by the Fm. lacerum anterius to supply the M. trochlearis (‘‘ obliquus superior ”’).
According to the Thesis of C. E. Manierre, this nerve enters the ocular aspect of the mus-
cle in the cat, while in man it enters the orbital or ectal aspect.

§ 1884. (V) Nervus trigeminus, JW. trg., the trigeminal or trifacial nerve —Fig. 116 ;
Pl. Ul, Fig. 3. Gray, A, 647; Quain, A, I, 532.

This is the largest of the cranial nerves and peculiar in several respects. Although

508 ANATOMICAL TECHNOLOGY.

commonly described as a single nerve, it really consists of two, the larger being sensory
(Radix sensoria) and the smaller motor (Radix motoria). It thus conforms to a myelonal
nerve, excepting that the ectal origins of the two roots are closely associated.

The sensory root is a large, slightly flattened band which lies across the pons just
where it is contracted to form the medipedunculus. When lifted from the pons, it is
found to have its ectal origin either just caudad of it or from its surface close to the caudal
border. - ;

In the senior author’s paper (14, 548), the nerve is simply said to arise caudad of the
pons. This statement was questioned in the Am. Jour. of Neurology, etc. (I, 108); a
reéxamination of several preparations shows the existence of the variation above indi-
cated, and a qualification has been published (Wilder, 24).

In man the ectal origin is through the pons nearer the cephalic than the caudal mar-
gin. In part, at least, the difference is due to the greater caudal extension of the human
pons (§ 1161).

At the cephalic border of the pons the root presents a large flattened ganglion (Gng. |
Gasseri) and then separates into three divisions—the ophthalmic, maxillary and mandibu-
lar. Of these, the first is the most mesal in position and the smallest, but with it are asso-
ciated the oculomotorius, trochlearis and abducens, all emerging together from the Fm.
lacerum anterius.

The maxillary division is intermediate and escapes by the Fm. rotundum. The man-
dibular division is lateral, is joined by the Radix motoria and emerges by the Fm. ovale.

The distribution is stated upon the Table (§ 1392), and corresponds in the main with
the three regions of the face; some filaments also supply the dura.

The motor root (Radix motoria) is much smaller than the sensory and not easily recog-
nized. Upon a fresh brain it may be seen as a narrow, light band crossing the sensory
root and the ganglion from the mesal side of the former, to attach itself to the mandibular
division. Upon an alcoholic brain, a dull tracer may be used to isolate it in the middle of
its course and follow it to its origin mesad and slightly cephalad of that of the sensory
root. We have not ascertained whether, as in man, it is separated therefrom by a few
fibers of the pons or of the trapezium.

In man the motor root is distributed to the muscles concerned in mastication (Dalton,
A, 464).

§ 1385. Nervus abducens, JV. abd., the abducens nerve.—Fig. 116; Pl. II, Fig. 3.
Gray, A, 641; Quain, A, I, 519.

A ribbon-shaped nerve, arising by three or four funiculi from the trapezium just laterad
of the pyramis. The attachment is very feeble and the nerve is apt to be torn off with
the pia. It associates itself with the ophthalmic division of the trigeminus and emerges
therewith by the Fm. lacerum anterius to be distributed to the MM. choanoidei and the
rectus lateralis (“ externus ”’).

§ 1386. (VII) Nervus facialis, VW. f., the facial nerve or “ portio dura.”—Fig. 116:
P]. Il, Fig. 3. Gray, A, 642; Quain, A, I, 548.

In some respects this is the motor counterpart of the trigeminus, being distributed to
most of the muscles of tbe face and head, excepting the muscles of mastication. It is
small as compared with the trigeminus, just caudad of which it arises from the latero-
cephalic angle of the trapezium. It traverses the ental auditory foramen, the Aqueductus
Fallopii and the stylo-mastoid foramen (§ 506).

§ 1887. (VIII) Nervus auditorius, V. av., the auditory or acoustic nerve or portio
mollis —Fig. 110, 116; Pl. II, Fig. 3. Gray. A, 639 ; Quain, A, I, 548.
This is commonly grouped with the olfactory and optic nerves as a nerve of special

THE CRANIAL NERVES. 509

sense; but according to Gegenbaur (Lankester), A, 515, it is developed like an ordinary
cranial nerve,

It springs from the cephalic part of the Eminentia auditoria, traverses the ental audi-
tory foramen, and is distributed to the sensory organs of the labyrinth or “ internal” ear.

§ 1388. (IX) Nervus glossopharyngeus, VV. gph., the glossopharyngeal nerve.—Fig.
116; Pl. Il, Fig. 3. Gray, A, 658; Quain, A, I, 554 ; Stowell, 7.

The origins of this nerve and of the vagus and accessorius are associated so as to form
a series extending caudad from the Eminentia auditoria for a considerable distance along
the lateral aspect of the cervical myelon. We have not examined these origins in detail,
and the reader is referred to the figures and descriptions of Stowell. As has been stated
elsewhere, the points of origin cannot be defined accurately until the ectal features of the
“medulla” are more satisfactorily understood.

The nerve has a ganglion (Gng. petrosum), emerges through the Fm. jugulare, and is
distributed, in man, to the base of the tongue, the soft palate and the pharynx.

§ 1889. (X) Nervus vagus, JV. »., the vagus or pneumogastric nerve.—Fig. 116; Pl.
II, Fig. 8. Gray, A, 660; Quain, A, I. 556; Stowell, 2.

This nerve, remarkable alike for its distribution, its accessions from other (motor)
sources, and its numerous and peculiar functions, arises just caudad of the glossopha-
ryngeus by several funiculi, which, according to Stowell, form two series, dorsal and
ventral. As stated under the glossopharyngeal, we have not fully examined the origin,
and the student is referred to the figures and descriptions of Stowell.

The nerve presents a ganglion (Gng. jugulare, ganglion of the root), in the proximal
end of the foramen of exit, and about 15 mm. peripherad of the foramen another, the Gng.
inferius or the ganglion of the trunk (Fig. 107; Stowell, 7).

Relations of the Ganglia.—The Gng. jugularis is connected by anastomotic filaments
with the N. facialis (VII), glossopharyngeus (IX), accessorius (XI) and sympathicus.
The ganglion of the root is connected with the N. glossopharyngeus (IX), accessorius
(XD), hypoglossus (XII), and sympathicus ; (Stowell, 7).

Besides the connections just named, the vagus furnishes the following branches: NN.
pharyngeus, laryngeus superior, laryngeus recurrens, rami cardiaci, rami pulmonares,
gastricus dorsalis and gastricus ventralis (Fig. 103, 107; $$ 1040, 1041). It also gives
many anastomotic filaments to the sympathicus (§ 1041 ; Stowell, 7).

§ 1890. (XI) Nervus accessorius, WV. ac., the accessory or “ spinal accessory ” nerve.—
Fig. 116; Pl. Il, Fig. 3. Gray, A, 686; Quain, A, I, 564; Stowell, 7.

This nerve has a peculiar and extensive origin by funiculi scattered along the lateral
aspect of the metencephalon and cervical myelon, from just caudad of the origin of the
vagus to a point opposite the 6th or 7th cervical nerve.

The trunk enters the cranium by the Fm. magnum, and then associates itself with the
vagus and glossopharyngeus to emerge through the Fm. jugulare. In man it is distrib-
uted to the trapezius and sterno-mastoid muscles, and also, by the fibers which join the
vagus, to the heart.

§ 1391. (XII) Nervus hypoglossus, WV. Apg., the hypoglossal nerve.—Fig. 116 ; Pl. II,
Fig. 3. Gray, A, 646; Quain, A, I, 565.

Arises by several (10-15) funiculi from the ventral aspect of the metencephalon just
laterad of the caudal half of the Area elliptica (oliva?). (The difficulty in the homology
of this area is referred to in $§ 1161, 1188.)

The funiculi are very slightly attached and apt to be torn off with the pia. The trunk
escapes through the Fm. condylare, and is distributed, in man, chiefly to the muscles of
the tongue.

This nerve has much the aspect of the ventral root of a myelonal nerve.

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THE ORGANS OF SENSE. 511

§ 1393. The demonstration of the cranial nerves requires
much care and skill on account of the great number crowded into
small space, and also because they pass through various bony
canals and foramina or are concealed by bony processes. The
beginner can hardly hope to demonstrate all satisfactorily on one
specimen. It is especially necessary to employ a young lean ani-
mal, in order that fat may not obscure the nerves and that the con-
nective tissue may not be so tough as to render the tracing of fine
nerves impossible. The general directions for dissecting nerves
given in §§ 1008, 1037, should be faithfully followed. Some of the
nerves may be traced on one side and some on the other. When-
ever a saw is employed, it is best to protect underlying parts if
possible by a cloth. In case a vessel or nerve is inadvertently sev-
ered, the two ends may be slightly lapped and tied with a thread.
The nippers employed should be sharp and narrow pointed (§ 146).
In using the nippers, remove very small pieces, and use the tracer
often to make sure that all branches are pushed aside. Have at
hand for constant reference a prepared skull, the figures of the skull
(Fig. 56-62), and the Tables of foramina (§ 562) and nerves (§ 1392).

THE ORGANS OF SENSE.

§ 1394. The organs of sense are the specialized parts of animals
which, being acted upon by objects in the external world, are capa-
ble of transmitting the impressions so received to the central ner-
vous system by means of nervous connections. Huxley, 5

The organs are five, corresponding to the five senses.

(A) Cutis and mucosa.—The skin, and mucous membranes near
the exterior (Dalton, A, 510). These are the organs of Touch (tac-
tion, tactile sensibility).

(B) Lingua (tongue), Soft Palate and Fauces. thse are the
organs of Taste (gustation, gustatory sensibility).

(C) Nasus, nose.—Its mucous membrane, especially that of the
maxillo-turbinals, forms the organ of Smell (olfaction, olfactory
sensibility).

(D) Oculus, eye.—The organ of Vision (sight or visual sensi-
bility).

(EB) Auris, ear—The organ of Hearing (audition or auditory
sensibility).

(F) General Sensibility.—In addition to the special sensibilities

512 é ANATOMICAL TECHNOLOGY.

just named, requiring a special apparatus, there is the so called
general sensibility of the body. ‘This is manifested whenever an .
ordinary sensory nerve is stimulated in any part of its course ;
when slight, it is called feeling ; when more intense, pain.

CUTIS—THE SKIN.

References.—Gray, A, 83; Quain, A, II, 211; Dalton, A, 510; Foster and Langley,
A, 165; Foster, A, 589; Leyh, A, 350; Stricker, A, 792; Chauveau, A, 841; Chauveau
(Fleming), A, 792; Owen, A, III, 186, 610; Gurlt, A, 815 ; Milne-Edwards, A, XI, 411;
Bernstein, A, 10; Flint, A, 381, 751.

§ 1395. Cutis, skin.—The skin or integument forms the covering
of the entire body. It is elastic and flexible, tough and dense,
hence well adapted as a protecting envelope. It is continuous
with the mucous membranes at the various natural orifices.

§ 1396. The skin is composed of two layers, ectal and ental.

Ectal Layer, Epidermis, Cuticle.-—Composed of nucleated cells, those nearest the sur-
face are flat ; the deeper ones are spherical or columnar and form the Rete mucosum,
which contains the coloring matter of the skin.

The function of the epidermis is almost wholly protective, and it is devoid of sensi-
bility.

Ental Layer, Derma, Corium, Cutis vera (true skin).—The true skin is composed of
elastic and white connective tissue, plain muscles, blood vessels, lymphatics and nerves,
The principal function of the Cutis vera is tactile sensibility or the determination of the
presence and character of objects which come in contact with the epidermis.

Into it are implanted the appendages of the skin—/air and claws, sweat and sebaceous
glands,

The sweat glands serve to get rid of some of the waste products of the body, while the
sebaceous glands pour out upon the surface an oily substance which keeps it soft and
pliable.

The hair and claws serve as protectors of the body. The hair covers the entire surface
of the body except at the tip of the snout, the pads of the hands and feet and the hy poth-
enar eminences. It protects the surface and assists more or less in touch, since a nervous
filament is connected with the implanted end of each hair. In addition to the ordinary
hairs forming the protective covering of the bedy, there are specialized hairs which, from
their connections, are undoubtedly tactile organs. These are situated, in the cat, on the
dorsal lip (Vibrissz, Fig. 87, 88), in the eyebrows (Fig. 87, 88), and on the antebrachium
(Fig. 76, 105, pili tactiles). They differ from common hairs in being longer and stiffer,
but especially in being implanted very deeply and in having a larger nervous and vascu-
lar supply.

For the structure and presence of tactile hairs in various animals, see Owen, A, III,
187; Curtis, L., 7,166; Schoebl, 10; Ranvier, A, 913; Milne-Edwards, A, XI, 424. For
the structure of the skin of the dog, see Stirling, 7, 465.

LINGUA—THE TONGUE.

References.—Gray, A, 707; Quain, A, II, 325; Dalton, A, 463, 513; Foster and
Langley, A, 176; Foster, A, 586; Leyh, A, 349; Stricker, A, 352; Chauveau, A, 355,

THE TONGUE AND NOSE. 513

859; Chauveau (Fleming), A, 344, 813; Owen, A, III, 190; Gurlt, A, 344, 814; Milne-
Edwards, A, XI, 437; Bernstein, A, 295 ; Flint, A, 759.

§ 1397. Lingua, tongue.—The tongue is the principal organ of
taste or gustation. It is a very movable muscular organ covered
with mucosa and situated in the mouth. Itis also possessed of a
high degree of tactile sensibility.

By its muscular structure it takes part in the processes of mastication and deglutition
and in speech. To it are distributed three nerves, the trigeminus to the tip, the glosso-
pharyngeus to the base and the hypoglossus to the muscles. The glossopharyngeus is
also distributed to the mucosa of the soft palate and the pillars of the fauces ; hence their
mucosa possesses a certain amount of gustatory sensibility. The parts upon the tongue
supposed to be the special seats of gustatory sensibility are the fungiform and cireumval-
late papille. These are briefly described in connection with Fig. 88, p. 306.

For supposed gustatory structures in the epiglottis of the dog and cat, see Schofield,
7, 475.

Demonstration.—The muscular structure of the tongue may be made out by such a
section as that shown in Fig. 88. The papillae may be seen on such a section, but better
on a tongue which has been removed with the mandible. The nervous supply of the
tongue may be determined by following the general directions for the dissection of nerves ;
see also Fig. 107, § 1008, and for the vagus and sympathic (§ 1037).

NASUS—THE NOSE.

References.—Gray, A, 710; Quain, A, II, 664; Dalton, A, 517; Foster and Langley,
A, 176; Foster, A, 584; Hyrtl, A, 385; Leyh, A, 349; Stricker, A, 792; Chauveau, A,
466, 862; Chauveau (Fleming), A, 439, 815; Owen, A, III, 204; Gurlt, A, 8145 Milne-
’ Edwards, A, XI, 453 ; Bernstein, A, 285; Flint, A, 754.

§ 1398. Nasus, nose.—In Fig. £9 and 88 are shown longitudinal sections of the nasal
passages. It will be seen, especially in Fig. 88, that there is a tolerably direct passage
from the prenaris to the postnaris through the so called meatus ventralis (inferior).
Dorsad of the meatus ventralis are the turbinated bones which are most intricately con-
voluted.

The membrana Schneideriana.is the mucosa of the nasal fosse. Through the com-
paratively minute spaces formed by the scrolls of the turbinated bones, the air may pass
from, the prz- to the postnaris, but its movement is much slower than when passing
through the meatus ventralis. The forms of the turbinated bones and the passages
through them may be well seen by transecting a cat’s head just cephalad of the mesal
canthi of the eyes (§ 1400). Through the lamina cribrosa (Fig. 60) pass the olfactory
nerves to be distributed to the mucosa upon the ethmo-turbinals; this mucosa is the seat
of the olfactory sensibility proper, that is, of the appreciation and distinction of perfumes
and odors. The mucosa of the maxillo-turbinals and meatus ventralis is supplied by ner-
vous filaments of the nasal branch of the ist or opththalmic division of the trigeminus
and possesses sensibility more like that of the skin. It takes cognizance of the pungent
vapors of such substances as ammonia.

The nervous supply of the nose may be determined by following the general directions
for the dissection of nerves (§ 1008).

33

514 ANATOMICAL TECHNOLOGY.

OCULUS—THE EYE AND ITS APPENDAGES.

General References.—Gray, A, 713; Quain, A, II, 583; Dalton, A, 519; Foster and
Langley, A, 178, 244; Hyrtl, A, 391; Leyh, A, 323 ; Straus-Durckheim, A, 201 ; Stricker,
A, 802; Morrell, A, 260 ; Chauveau, A, 862 ; Chauveau (Fleming), A, 817; Owen, A, III,
246; Foster, A, 510; Gurlt, A, 775 ; Milne-Edwards, A, XII, 94; Bernstein, A, 48; Flint,
A; Le Conte, A.

Instruments and Material.—Scalpel; arthrotome; fine and coarse scissors; fine and
coarse forceps ; tracer ; flexible blow-pipe; nippers; tripod lens ; beaded bristles ; skull
prepared as in Fig. 56.

§ 1399. The eye is the organ of the sense of sight (§ 1394, D).
It is situated in the orbital fossa (ig. 56), which in the cat is in-
complete.
In connection with the eye proper are certain appendages which
protect, lubricate and move the eyeball.

APPENDAGES OF THE EYE.

§ 1400. Palpebre, eyelids.—The eyelids are modified folds of
skin which protect the cephalic surface of the eye. There are two
for each eye, which from their position are called respectively the
dorsal (upper) and ventral (lower) lid. Their ectal surface is cov-
ered with hair, but there are no eyelashes ; their ental surface, that
next the eyeball, is lined with a smooth mucous membrane, the
conjunctiva (Fig. 126, cnjct.).

The two points where the eyelids meet are called the canthi or
angles of the lids; a mesal (inner) or nasal and a lateral (outer) or
temporal edntives.

Dissection of the Lids.—Make an incision through the skin
from the angle of the mouth to a point opposite the base of the ear,
and then transversely to the dorsimeson. Then make an incision
from the lateral canthus directly caudad to the transverse incision.
Reflect the ventral eyelid and the skin nearly to the mesal canthus,
noting that the smooth mucous membrane (conjunctiva) lining the
lid is continuous with the covering of the eyeball (Fig. 126).

§ 1401. Meibomian Glands.—Grasp the free edges of the lids
and evert them. On the mucous membrane there will be seen
many parallel, broad, yellowish lines, extending from the edge of
the eyelid for about 2 mm. (Fig. 126). These are the Meibomian
glands. They secrete a sebaceous substance which is poured out
upon the edges of the lids through minute orifices ; these may be
seen at the top of slight elevations by employing a tripod magnifier.

APPENDAGES OF THE EYE. 515

§ 1402. Membrana nictitans, third eyelid (Fig. 126). —The
third eyelid is a fibrous, crescent-shaped organ situated at the mesal
canthus between the eyelids proper and the eyeball. Both of its
surfaces are covered by a continuation of the conjunctiva. Its
cephalic edge is free and dark bordered, its caudal edge is flexibly
attached to the eyeball (Fig. 126).

The office of the membrana is to keep the eye free from dust.
The generalization made by Chauveau, A, is, “That it is most
developed in animals that are unable to use their cephalic limbs
for removing foreign particles from the eye.”’

Demonstration.—The movement of the membrana depends upon
that of the eyeball, not upon the action of special muscles. There
are, however, a few striated muscular fibers in the band of connec-
tive tissue passing from the rectus ventralis to the membrana as
shown in Fig. 126. If the membrana is not visible, press upon the
cornea so as to force the eyeball farther into the orbital fossa, and
it will appear. It may be made to entirely cover the cornea. To
cause it to disappear, cut the masseter muscle and force a scalpel
handle into the orbital fossa so as to push the eyeball cephalad.

§ 1403. Lachrymal Apparatus.—This consists of the lachrymal
- or tear glands and their ducts. The glands are, in general struc-
ture, like the salivary glands (§§ 788, 789). They are situated near
the lateral canthi of the lids.

Demonstration.—(A) Glandula lachrymalis, lachrymal gland
proper.—Nip the orbital process of the frontal and malar bones, cut
the soft parts connecting the malar process, and turn the end dor-
sad. The lachrymal gland will cling to the reflected part. It ap-
pears like the molar gland (§ 785), and is so formed as to mold
itself to the eyeball upon which it naturally rests.

(B) Glandula Harderi.—Harder’s gland, situated on the convex
or ectal surface of the membrana nictitans, extends from near its
attached border over about one third its width (Fig. 126). It is
very apparent after the removal of the eyeball (§ 1415).

It is found only in animals possessing the third eyelid (Milne-
Edwards, A, XII, 121).

Lachrymal Canal.—On the free edge of each eyelid, about 3
mm. from the nasal canthus, is the opening of a lachrymal canal.
These canals collect the tears and convey them to the lachrymal
duct.

Demonstration.—The openings of the lachrymal canals may

516 ANATOMICAL TECHNOLOGY.

be seen easily by drawing the eyelids well apart and looking with a
magnifier at their free edges near the mesal canthus. Insert a
beaded bristle into each canal.

Lachrymal Duct.—This is formed by the union of the two canals
and extends to the nasal cavity. Its beginning i is somewhat dilated
and is called the lachrymal sac.

Demonstration.—_Slightly expand the preenaris and push the _
beaded bristles mentioned above until they appear at the nasal
opening of the lachrymal duct. This opening is just ventrad of the
cartilaginous prolongation of the maxillo-turbinal bone (at a point
ventrad of the M of the abbreviation “ Mxtrb.”’ in Fig. 88). The_
opening is quite large and will readily receive the probe of the tracer.
If it is desirable to trace the lachrymal duct throughout its course,
a bristle should be put into it. Then the head should be hemi-
sected, and the duct traced with nippers and arthrotome, com-
mencing at its nasal termination.

MUSCLES OF THE EYE.

The cat’s eye possesses 12 muscles, ten belonging to the eyeball
(4 recti, 4 choanoid, the trochlearis and the obliquus ventralis), and
2 to the lids—orbicularis palpebrarum (§ 1404) and levator palpe-
bre dorsalis (§ 1409). Besides the special muscles of the eyelids,
the muscles of the face assist and modify their movements.

§ 1404. M. orbicularis palpebrarum (Fig. 126, M. orb. plpbr).
—This is the circular muscle surrounding both lids and serving to
close them. To demonstrate it, cut either of the lids transversely.
Just entad of the skin will be seen the cut ends of a thin layer of
pale, striated muscular fibers. The fibers are plentifully mixed
with elastic and white connective tissue.

For the M. levator palpebre dorsalis, see § 1409.

§ 1405. Exposure of the Muscles of the Eyeball.—These as
well as the levator palpebre are within the orbital fossa. _To expose
them, cut with nippers the two ends of the zygoma (Fig. 56). Grasp
the orbital process with the forceps and lateriduct it. At the same
time sever the soft parts close to the bone with an arthrotome, so
that the zygoma can be removed. Remove the temporal and mas-
seter muscles by grasping their cephalic edge and severing the
attachments. In doing this, be very careful not to include any of
the fibrous capsule of the eye. After these muscles are removed,
nip away half of the mandible ; then remove the part of the maxilla

MUSCLES OF THE EYE. 517

containing the molar and the last or largest preemolar tooth. This
will expose the lateral aspect of the eyeball and a muscle (ptery-
goid) extending obliquely from the mandible to the floor of the
orbit. There is also brought clearly into view the superior max-
illary artery and the superior maxillary division of the 5th nerve.
Both extend along the floor of the orbit laterad of the eyeball to the
infraorbital foramen (Fig. 50, Fm. inf. or.), from which point they
are called infraorbital artery and nerve. They should be carefully
removed. Two of the muscles of the eyeball will appear, M. rectus
ventralis, M. rectus lateralis. Raise the eyeball somewhat with
a scalpel handle and cut the pterygoid muscle at its origin in the
floor of the orbit. Note that the edges of the recti muscles slightly
overlap near their origin, but separate like the sepals of a flower as
they extend cephalad toward the eyeball. Separate them, and
trace first the M. rectus lateralis to its attachment on the eyeball,
removing the loose fibrous substance with scissors. Do not injure
the tendon of the ventral oblique (see § 1406).

Pass a scalpel handle entad of the free edge of the muscle, raise
it and free it from the underlying tissue with a tracer. When free,
raise the muscle by the scalpel handle and make it tense. It will
be seen to terminate in a broad ribbon-like tendon which is inserted
into the sclerotic at the caudal margin of the white zone of the eye-
ball (Fig. 126, Z. a.).

§ 1406. M. obliquus ventralis (inferior), the ventral or inferior
oblique muscle.—In clearing away the fibrous tissue from the ball
to expose the lateral rectus, this muscle also will be exposed. It
appears as a circular band overlapping the ventral rectus. Sepa-
rate the body of the muscle from the other tissues, and lift it up
with the scalpel handle as for the lateral rectus, and it will be seen
to insert itself by a broad tendon along the edge and cephalad of
the tendon of the lateral rectus. The tendons of these two muscles
form a right angle. Raise the eyeball with a scalpel handle and
trace the ventral oblique to its origin from the orbital surface of the
maxilla just laterad of the Os lachrymale (just laterad of the ‘‘h”’
of the abbreviation “ O. Ich.” in Fig. 56).

§ 1407. M. rectus ventralis (inferior), (Fig. 126, M. r. vntr.).—
This appears on the ventral side of the eyeball. Draw it out so as
to show the attachment ; then dissect the body of this muscle as
directed for the lateral rectus, and raise it in order to note its inser-

518 ANATOMICAL TECHNOLOGY.

tion at the caudal margin of the white zone as with the lateral rec-
tus (Fig. 126). ;

§ 1408. M. rectus dorsalis (superior), (Fig. 126, M. r. drsl.).—
Cut for about 1 cm., close to the bone, the fibrous band holding
the eyeball to the postorbital process of the frontal. Draw the eye-
ball cephalad, and the dorsal rectus will appear on the dorsal side
of the eyeball. Dissect it as described for the others (§ 1405), and
note that its insertion is at the same level on the eyeball, as shown
in Fig. 126.

A considerable band passes from the ventral rectus to the Mem-
brana nictitans. This is composed mostly of connective tissue, but
with the microscope a small number of muscular fibers may be
found in it. It is thus a retractor of the Membrana nictitans.

§ 1409. ML. levator palpebre dorsalis (superioris).—This very
thin, slender muscle may be seen by grasping some of the fibrous
substance near the cornea and drawing the ball cephalo-ventrad.
It is on the ectal surface of the dorsal rectus for the first fourth of
its length, then it inclines mesad. Isolate it with the greatest care.
About opposite the point of insertion it spreads out into a broad
tendon, which is attached to the dorsal lid (Fig. 126). Grasp the
edge of the dorsal lid and raise it from the ball; then pull upon the
muscle, and the traction can be seen on the ental surface of the lid.

§ 1410. M. rectus mesalis (internus). — Divide the ventral
oblique and sever the fibrous connection of the eyeball with the
orbital fossa on the ventral side to a point about opposite the open-
ing of the lachrymal canal on the dorsal lid ; then evert the Mem-
brana nictitans and draw the eyeball laterad. This will expose the
mesal rectus. Its attachment to the eyeball should be determined
as described in § 1405.

§ 1411. M. trochlearis s. obliquus dorsalis (superior).—This
muscle will appear mesad of the rectus mesalis. Draw the eyeball
caudad and laterad and isolate the muscle from its origin toward its
insertion. When about opposite the middle of the eyeball, it
merges into a slender tendon which extends to a point a little cau-
dad and entad of the mesal canthus, where it passes through a
fibro-cartilaginous ring. This ring is held somewhat loosely to the
bony orbit, nearly directly opposite the origin of the ventral
oblique, by a strong fibrous band about 4 mm. long extending
directly dorsad, and a slender one about 25 mm. long attached to

MUSCLES OF THE EYE. 519

the postorbital process of the frontal (Fig. 56, Pre. po.). To demon-
strate these bands, draw the eyeball laterad and pull upon the
fibro-cartilaginous pulley. The tense lines show the direction of
the bands and serve as guides in isolating them. Continue to draw
the ball laterad and isolate the tendon of the M. trochlearis after it
passes the pulley. Draw it taut and it will be seen to pass directly
laterad toward the eyeball. It passes entad of the M. levator pal-
pebre and then expands into a thin sheet which is inserted into the
eyeball at right angles to the insertion of the dorsal rectus, as the
ventral oblique is inserted into the ball at right angles to the lateral
rectus (§ 1406).

§ 1412. IMM. choanoidei, s. M. choanoideus, s. MM. recti
minores, s. MM. recti posteriores, s. M. suspensor oculi.—These
are four straight muscles like the recti proper, but smaller. They
may be demonstrated by separating the recti muscles. They will
. be seen to alternate with the recti as they extend along the eyeball
to their insertion, which is by a broad, thin tendon near the middle
of the eyeball. This is true of all but the ventral (inferior) one,
whose tendon, like those of the recti, is inserted into the edge of the
white zone of the sclerotic (Fig. 126).

§ 1418. Origin of the Muscles of the Eye.—All of the muscles
of the eye described above, except the orbicularis palpebrarum
(§$ 1404) and the obliquus ventralis (§ 1406), arise in a circle sur-
rounding the optic nerve at its exit from the skull, thus forming for
it a muscular sheath.

The levator palpebre dorsalis arises near the sutura fronto-
orbito-sphenoidea, dorsad of the origin of the dorsal rectus, which
arises very near the foramen opticum.

The ¢rochlearis is in like manner ectad of the mesal rectus.

The lateral rectus passes between the tendon of the ventral rec-
tus and the combined tendon of the choanoid muscles to be inserted
into the septum between the optic and anterior lacerated foramina.

The ventral rectus arises from the lateral and ventral aspects of
the foramen lacerum anterius, and just ectad of its origin is the
common tendon of the four choanoid muscles (Fig. 126).

In determining the origin of the muscles, the connections of the
eyeball should be so far separated from the socket that one may
work in any part of the orbital fossa without difficulty.

§ 1414. Action of the Muscles of the Eye.—With the recti this is probably as in
man, viz., that they move the eye in the direction of the four cardinal points according to

520 ANATOMICAL TECHNOLOGY.

their attachment. The oblique muscles are so differently attached from those in man that
the action could hardly be the same (Quain, A, I, 277). It would seem from the anatomi-
cal arrangement that the ventral oblique would simply rotate the eyeball laterad and the
trochlearis would rotate it mesad.

§'1415. The nervous supply is given.dm the Table of cranial nerves (§ 1892), distri-
bution of the 3d, 4th, 6th and 7th nerves. le nerves may be made out on a fresh or alco-
holic specimen by following the general directions for dissecting nerves in $§ 1008, 1037.

GLOBUS OCULI—EYEBALL.

§ 1416. How to Obtain the Eyeball.—The one exposed in dis-
secting the. muscles may be severed from the head by cutting the
muscles near their middle and the optic nerve about 1 cm. from the
ball; or a fresh eye may be exposed as described for studying the
muscles (§ 1405) and then severed as just described. In case it is
undesirable to injure the skull, or the eye of an ox or sheep is to
be obtained, grasp the lids successively, and turning the concavity
of the curved scissors toward the eyeball, sever the connection with
the lids. Grasp the membrana nictitans and draw the eyeball
cephalad. Keeping the concavity of the scissors toward the ball,
cut its fibrous and muscular connections with the orbit; cut also
the optic nerve about 1 cm. from the ball.

After the eyeball is removed, carefully free it from all tissue
except the membrana nictitans and the lateral and dorsal recti
muscles. These should be left to enable one to determine the
aspect of the eye.

§ 1417. Note the following :—(A) In form, the eyeball of the cat
is spheroidal and somewhat pointed cephalad (Fig. 126). (B) The
cephalic third (cornea, § 1421) is transparent and continuous with (C)
the selerotica (§ 1421), which forms the rest of the ectal wall of the
eyeball. (D) WV. opticus, at the caudal part of the eyeball enters
the large cylindrical optic nerve.

§ 1418. Iris et Pupilla (Fig. 126).—Upon looking into the cor-
nea there will be seen a golden-yellow circular curtain, the iris.
This curtain is not complete, but in the middle is an opening, the
pupil. The form of the pupil in the cat is cireular when fully
dilated, as in a cat killed with chloroform. When partly contracted
it is elliptical, but when fully contracted it is a dorso-ventral slit.
These various forms are readily seen in a living cat’s eye by trans-
ferring the cat from a dim into a brilliant light.

' § 1419. Images Formed by the Eye.—If the eye is perfectly
fresh, so that the cornea is transparent, rub some strong glycerin on

COATS OF THE EYEBALL. 521

the caudal part of the sclerotic to make it transparent; hold the
eye with the cornea toward a well-lighted window or a lamp flame.
The image of the window or flame will be seen on the caudal aspect
of the eyeball; the image is real, and hence inverted like that
formed by a photographer’s camera. Raise or lower the eyeball,
and the image will be seen to move in the opposite direction. Ifthe
eye of a large animal is used for this experiment, a piece must be
removed from the caudal part of the sclerotic on account of its
opacity.

§ 1420. Tunice oculi—Coats of the eye (Fig. 126).—For the
study of the remaining parts of the eye, a fresh one may be used,
but one hardened in alcohol is desirable, as such a one retains its
form and the various parts are less easily torn and displaced. To
harden an eye, cat a slit in the sclerotic at one side and place the
eye on absorbent cotton in 62 per cent. alcohol for a day; then
. remove to 95 per cent. for two days or more.

Dissection.—With forceps and scissors make an incision from
about the middle of the cornea to near the optic nerve, taking care
to cut only through the wall. Connect the same two points by
another incision in such a way as to remove a segment containing
one fourth or one fifth of the entire wall of the globe. In this seg-
ment the different tunics may be studied.

§ 1421. Sclerotica et Cornea (Fig. 126).—Together these form
the ectal covering or framework of the eyeball.

The sclerotic covers the caudal three fourths of the eyeball and
becomes thickened before merging into the cornea. This thicken-
ing has the appearance of a white band around the eyeball, and
for convenience may be called the Zona alba (Fig. 126, Z. a.) or
white zone. At the caudal margin of this zone are inserted the recti
muscles. Its width indicates the length of the plice ciliares (§ 1422).

In the ental wall of the sclerotic are many pigment cells (lamina
Jusca), giving it a dark appearance; and on the line where it
merges into the cornea these pigment cells extend through to the
ectal wall of the sclerotic. The cornea completes the framework of
the eyeball cephalad. It is transparent and intermediate in thick-
ness between that of the white zone and the rest of the sclerotic.

§ 1422. Choroidea (Fig. 126).—The choroid coat of the eye is
just entad of the sclerotic. It is a vascular coat, but contains also
much pigment, hence its dark appearance. With a tracer separate
the choroid and sclerotic as shown in Fig. 126. The choroid does

522 ANATOMICAL TECHNOLOGY.

not extend cephalad of the iris. Opposite the white zone it is folded
into plaits (Plice ciliares, Fig. 126). There are about seventy of
these plaits or folds.

§ 1423. Iris.—The iris, as stated above, is the circular perforated
curtain caudad of the cornea. Its caudal surface is black, its
cephalic a golden yellow, which gives color to the eye. It is at-
tached at its circumference to the choroidea, the cornea and the
sclerotic.

§ 1424. Retina (Fig. 126).—The retina is the ental coat or tunic
of the eye. It isan expansion of the optic nerve to which are added
nerve cells and various other parts (see Quain, A, IT, 605). It is the
sensitive part of the organ of sight. It may be separated from the
choroid as shown in Fig. 126 by using a scalpel handle. Note that
it is of nearly uniform thickness until it reaches the margin of the
ciliary folds, Ora serrata (Fig. 126). Its extension upon the folds
becomes thin and is called the Pars ciliaris retine. The entrance ~
of the optic nerve appears as a round white spot, macula lutea
(blind spot).

§ 1425. Tapetum (Fig. 126)—In the eye of the cat, as in many
other animals, the retina does not contain pigment over its whole
extent, but is devoid of it in its dorso-mesal part. Here the cho-
roid is brilliantly colored, forming the so called Tapetwm. The
color is metallic golden-blue green. In this part of the choroid is a
deposit of mineral salts of calcium which assists in giving the lumi-
nous appearance to the cat’seye in a dim light (Milne-Edwards, XII).

§ 1426. Humor aqueus.—The aqueous humor is a clear watery
fluid which fills the space between the cornea and the iris and lens
and also the small space between the iris and the plice ciliares (Fig.
126). These spaces are called, from their position, Camera aquosa
cephalica (anterior), cephalic or anterior aqueous chamber (Fig. 126,
C. aq.), and Camera aquosa caudalis (posterior), caudal or posterior
aqueous chamber (Fig. 126, C. a.).

§ 1427. The corpus vitreum or vitreous humor is a transparent
jelly-like substance occupying the greater space of the eyeball. It
is bounded cephalad by the lens and ciliary processes and at all
other points by the walls of the eyeball.

§ 1428. Lens (lens crystallina)—Crystalline lens (Fig. 126).—
The lens is the double convex transparent body situated between the
aqueous chambers and the vitreous body. Its cephalic convexity

DORSO-VENTRAL SECTION OF THE EYE. 523

is greater than its caudal. In the fresh eye it is perfectly transpar-
ent, and its ectal part is soft, while its ental part is firmer. In an
alcoholic eye it is hard and mostly opaque.

§ 1429. Capsula lentis (Fig. 126, Cpsl.).—This is the sac surround-
ing the lens. Grasp the cut edges of the white zone, and attempt
to spread the eyeball out flat. ‘There will be seen a tense line pass-
ing from the plice ciliares to the edge of the lens. At the same
time look at the lens, and there will be seen enveloping it a thin
transparent membrane, which is the capsule. Blow with a blow-
pipe (Fig. 19) against the lens where the tense line is attached, and
the air will get between the lens and its capsule, thus making the
latter very evident.

§ 1430. Zonula Zinnii, s. Ligamentum suspensorium (Fig. 126,
Z. Z.).—This is the fibrous connection of the lens capsule with the
plicee ciliares. By pulling upon the lens capsule and the sclerotic,
this suspensory ligament will be seen attaching itself to the Ciliary
plice (Fig. 126).

Preparation of Fig. 126.—A cat’s head was removed and frozen solid. The skin was
cut with a scalpel along the dorsal surface of the head to indicate the direction of the sec-
tion. Then the section was made with a fine tooth back-saw (Fig. 21). The débris was
removed by carefully scraping with a scalpel, and the outlines were obtained immediately
by means of a photographer’s camera. The relative position, size, insertion and origin of
the muscles were obtained by subsequent careful dissection on several specimens. The
form of the eyeball and the relations of the parts were verified on six eyes by carefully
removing and freezing them and then making sections with a watch-spring saw.

The plice ciliares (P.c.) are about 70 in number, but in order that they might be shown
distinctly only a few of them were drawn. The ciliary muscle in the cat has not been sat-
isfactorily worked out, hence its limits and size have not been clearly indicated in the figure.
On the ventral side the retina and choroidea are shown as separated from the sclerotica
and from each other. Finally, the muscles of the head closely related to the M. orbicu-
laris palpebrarum have not been indicated.

Description of Fig. 126.—Camera aquosa posterior (C. a.).—The posterior (caudal)
aqueous chamber. It is situated between the Zonula Zinnii and the iris.

Camera aquosa anterior (C. aq.).—The anterior (cephalic) aqueous chamber. It is
bounded by the /ens, tris and cornea.

Canalis Schlemmii (Cn. Shlm.)—The canal of Schlemm in the cat is double and often
triple. It is a venous sinus.

Capsula (Cpsl.).—Capsule of the lens. This is an elastic sac completely inclosing the
lens, To it is attached the suspensory ligament or zone of Zinn.

Choroidea, s. Tunica vasculosa.—This is the dark brown membrane composed chiefly
of blood vessels and lying between the sclerotica and retina. It extends cephalad to the
iris. Opposite the zona alba of the sclerotica the choroidea is plaited or folded, forming
the plice ciliares or ciliary processes.

Conjunctiva (Cnjct.).—The conjunctiva is the mucosa lining the lids, covering both

524 ANATOMICAL TECHNOLOGY.

Fic, 126.—DoRSO-VENTRAL (VERTICAL) SECTION OF THE CAT’s LEFT EYE, IN SITU.
x about 2.5.

surfaces of the membrana nictitans and the cephalic surface of the eyeball. It is indicated
by oblique cross lines.

Cornea.—The transparent cephalic part of the eyeball. It isa continuation of the
sclerotica. Their junction is indicated by a dar’x band.

Foramen opticum (Fm. op.).—Foramen for the optic nerve (Fig, 57, § 562).

Foramen lacerum anterius (Fm. 1. a.) s. Fissura sphenoidalis——A great many
structures traverse this foramen (§ 562), and from its lateral wall arise the ventral rectus
and the choanoid muscles.

Foramen rotundum (Fm. rt.), (§ 562).

Glandula Meibomiana (G1. M.).—The Meibomian glands (§ 1401) pour out a seba-
ceous substance on the edge of the lids.

DORSO-VENTRAL SECTION OF THE EYE. 525

Glandula Harderi (Gl. Harder).—A small lachrymal gland pouring out a lubricator
on the ental or concave surface of the M0. nictitans (§ 1403, B).

Iris.—This is the contractile diaphragm just cephalad of the lens. Its cut edges are
shown in the figure, and it is represented as dilated to a circle (§ 1418). Its muscles are
of the unstriped variety, yet they act rapidly and appear as if almost voluntary in the cat.

Lens.—The lens in the cat is double convex as in man, but unlike the human lens,
that of the cat is the more convex cephalad (§ 1428).

Macula lutea (Mcl.).—This is the white or blind spot of the eye. It is the end of the
optic nerve as it enters the eyeball. :

Membrana (Mb.) nictitans.—This is the internal or third eyelid. It has a black free
border (§ 1402).

Mucosa.—Mucous membrane of the roof of the mouth.

M. ciliaris (M. c.).—The ciliary muscle. This is attached to the sclerotica and cho-
roidea. By its contraction and relaxation the lens is made more or less convex, and hence
accommodates the eye for near or distant objects. The limits of this muscle have not
been satisfactorily determined in the cat.

M. levator palpebre dorsalis (M. lv. plpbr.).—The elevator of the dorsal (superior,
upper) lid is a slender muscle. It must be greatly aided by the ectal muscles of the head.

M. rectus dorsalis (superior), (M.r. drsl.)—The dorsal straight muscle of the eye.
It is cut longitudinally, hence its tendon is seen on edge.

M. rectus lateralis (externus), (M. r. Itrl.)—The muscle is cut and reflected ventrad
to show its origin from the bony septum between the Fm. op. and Fm. 1. a., and also that
it is between the tendon of the ventral rectus and the common tendon of the choanoid
muscles (§ 1405).

M. rectus ventralis (inferior), (M.r. vntr.).—The ventral rectus has been divided
longitudinally and is seen on edge. Its origin is from the lateral wall of the Fm. 1. a.

M. choanoideus mesalis (M. ch. m.).—The tendon of this muscle crosses the optic
nerve as shown.

M. choanoideus dorsalis (M. ch. drsl.).—This muscle and its tendon are seen on edge.

M. choanoideus lateralis (M. ch, 1.).—The tendon of this muscle is seen in its width.

M. choanoideus ventralis (M. ch. vntr.).—The ventral of the choanoid muscles.
The common tendon of the choanoids seems to be a continuation of this as it goes to its
origin from the Fm. 1. a. (§ 1413).

M. obliquus ventralis (inferior), (M. oblq. vntr.)—The cut end of the ventral oblique
muscle (§ 1406).

M. orbicularis palpebrarum (M. orb. plpbr.).—The cut ends of this circular muscle
are shown in each lid. The ectal muscles of the head mingle with this, but they are
omitted from the figure.

M. pterygoideus.—This corresponds to the external pterygoid of man. It passes from
the O. palatinum to the mesal side of the mandible (Straus-Durckheim, A, I, 217).

N. maxillaris superior (N. mx. spr.).—The second division of the trigeminus nerve.
Its distribution is given in the Table (§ 1392).

N. opticus (N. op.).—The optic nerve is seen traversing the optic foramen on its way
to the eyeball. It is surrounded by dura which is continuous with the sclerotica.

Ora serrata (Ora sr.).—The retina at the beginning of the ciliary plice becomes thin,
and, as in man it is somewhat indented, it is called ora serrata. The serrated appearance >
is not marked in the cat. The retina is very thin from the ora to the tips of the ciliary
processes, where it ceases. This part of the retina is called the pars ciliaris retine ($ 1424).

O. frontis.—The frontal bone (§ 516).

O. orbito-sphenoideum (O orsph.), ($ 515).

526 ANATOMICAL TECHNOLOGY.

Palpebra dorsalis.—The dorsal (superior or upper) eyelid. The dorsal lid does not
contain a tarsal cartilage as in man (Quain, A, II, 584), and there are no eyelashes (cilia),
(§ 1400).

Palpebra ventralis (Plpbr. vntr.).—The ventral (inferior) or lower lid, like the dorsal,
possesses no lashes (§ 1400).

Pili tactiles.—Tactile hairs. The bulb of one is shown to indicate its great size and
deep implantation (§ 1396).

Plicz ciliares (P. c.) s. processus ciliares, ciliary plice or processes.—They are foldings
of the choroidea. The abbreviation is written on one shown in its full extent. It is approx-
imately triangular in outline, and to its tip is attached the zonula of Zinn, and into it pass
many strong bands forming part of the suspensory ligament. The folds bifurcate caudad
and gradually merge into the general surface of the choroid (§ 1422).

Retina.—The nervous tunic of the eye. It is the ental of the three coats. In the
figure its cut edge is crossed by lines, and on the ventral side it is drawn away from the
choroid and toward the center of the eye (§ 1424).

Sclerotica.—This with the cornea forms the ectal coat of the eye. In the cat it is
very thin except opposite the iris and ciliary plice. Here it is thickened and has been
termed, provisionally, Zona alba (§ 1421).

Tapetum.—The brilliantly colored part of the ental surface of the choroidea (§ 1425).

Vitreum.—The vitreous body or vitreous humor. It fills the entire space caudad of
the lens and zonula of Zinn. It is clear and somewhat jelly-like. The canal of Petit is
merely an interval between the vitreum and the zonula, As it is not supposed to exist
during life, and certainly did not appear in the sections of the frozen eye, it has been
omitted.

Zona alba (Z. a.).—This is a thickening of the sclerotica giving firmness to the eye-
ball. Into its caudal edge are attached the recti muscles ($$ 1407, 1408).

Zonula Zinnii (Z. Z.) s. Ligamentum suspensorium lentis.—The suspensory ligament
in the cat is attached to the lens capsule at the edge of the lens and passes not only to the
summits of the ciliary processes, but into their substance as shown in the figure. More-
over, there is an especially strong part of the ligament opposite the summit of each ciliary
process.

AURIS—ORGANUM AUDITUS—EAR. (Fig. 127, 128.)

General References.—Gray, A, 729; Quain, A, II, 626; Dalton, A, 554; Flint, A;
Foster and Langley, A, 201; Foster, A, 574; Hyrtl, A, 413; Leyh, A, 388; Stricker, A,
950 ; Chauveau, A, 880 ; Chauveau (Fleming), A, 846 ; Owen, A, III, 235; Gurlt, A, 79,
799 ; Milne-Edwards, A, XII, 1; Bernstein, A, 164.

Instruments and Material. — Watch spring saw; nippers; dissecting instruments

(§ 181) ; tripod magnifier ; 15 per cent. glycerin ; cat’s head ; macerated skull prepared as
in Fig. 57.

§ 1431. Auris, ear.—This, the organ of hearing in the cat as in
the higher animals generally, is composed of three parts, two of
which (labyrinth and tympanum) are completely encased in bone.

(A) Auris ectalis (externa), ectal or external ear.—This includes
the external ear, commonly so called, which is partly cartilaginous,
and the meatus auditorius ectalis (externus), a partly bony canal

THE EXTERNAL EAR. 527

leading to the membrana tympani. . Both are lined with skin, which
extends also over the membrana tympani.

(B) Tympanum s. Auris media (Fig. 127).—The middle ear is an
elliptical cavity in the bone, lined with mucous membrane and con-
taining the bones of the ear and their muscles and the chorda tym-
pani nerve. Into it opens the Eustachian canal (Fig. 58, 88), which
puts it into communication with the pharynx.

(C) Labyrinthus s. Auris entalis (interna), (Fig. 127).—The
ental (internal) ear or labyrinth is the sentient portion of the ear.
It consists of three parts, a common cavity (vestibulum), from which
extend the other two—in one direction the canales semicirculares,
in the other the cochlea. In the living body the cavity of the inter-
nal ear is closed and lined with a thin periosteal membrane, but in
the macerated skull the fenestra rotunda and fenestra ovalis put it
into communication with the tympanum.

Dissection.—Remove the head of a young cat and wash away —
the blood.

§ 1482. Auris ectalis.—The external ear. The outer prominent
part turns its concave surface latero-cephalad. Note its flexibility
and elasticity, also the little pocket on its lateral border (Fig. 87).
Spread the edges apart. Note the numerous ridges and winding
ways, and that it is only partially covered by conspicuous hairs.
At its latero-ectal aspect is the opening into the Meatus auditorius
ectalis, the walls of which are firm and, near its termination, bony.

Remove the mandible, os hyoides, tongue and larynx, also the
skin from one side, including the external ear. Then isolate the
facial (7th) nerve as it emerges from the F'm. stylo-mastoideum (Fig.
57, Fm. stm.). Partially isolate also the Eustachian canal. The
opening of the canal will be exposed as shown in Fig. 88, by slitting the
soft palate lengthwise and turning the flaps aside. From this point
the canal extends cando-laterad to the bony Eustachian tube (Fig.
58, Cn. Eu.). Remove from around the bulla (Fig. 57) everything
except the Eustachian canal and the facial nerve. Cut the carti-
laginous part of the meatus where it joins the bony part, but do
not allow the instrument to enter the latter.

§ 1433. Membrana tympani (Fig. 127).—Place the head in a
good light and look into the bony ectal meatus. A nearly trans-
parent membrane will be seen, the Membrana tympani. It sep-
arates the ectal ear from the tympanum. Note the white rod (handle
of the malleus) extending across its dorsal third.

528 ANATOMICAL TECHNOLOGY,

§ 1434. Tympanum s. Auris media.— With nippers remove the
wall of the mesal chamber of the tympanic bulla (Fig. 58), and
note the delicate membrane lining it, also the bony septum (Fig. 58,
Spt. tym.) separating this chamber from the tympanum proper
except at a point directly ventrad of the fenestra rotunda, where it
is notched, thus forming a free communication between the two
chambers of the bulla (Fig. 58). Carefully remove the septum with
nippers and use the scissors for cutting its lining membrane, so that
nothing may be removed by inadvertence. Holding the head in
the hand, allow the light to fall upon the tympanum from various
directions. Note the attachment of the membrana tympani to a
ring of bone terminating the ectal bony meatus, and that the mem-
brane is conical in form, the apex projecting into the tympanum.

§ 1435. Canalis Eustachiana (Fig. 58, 88).—This, as stated
above (Fig. 88), is the canal connecting the pharynx and tympa-
num. Insert a beaded bristle into the pharyngeal opening (Fig. 88)
and it will appear at the tympanic opening in the cephalic part of
the tympanum, just dorsad of a projecting shelf of bone.

Ossicula auditus, Bones of the Ear (Fig. 127).—There are three
of these, malleus, incus and stapes, extending in a chain from the
membrana tympani to the fenestra ovalis.

§ 1436. Mallieus, hammer (Fig. 127)—The malleus is the first
of the chain of ear bones. Its handle stretches partly across the
membrana tympani. With the tracer move the handle; it will
sway but little. Note that the neck and head of the malleus form
an angle with the handle, and that attached to a small cylindrical
process of bone arising from the mesal aspect of the neck, is the
short tendon of the tensor tympani muscle (the WZ. Hustachianus
of Straus-Durckheim, A, IT, 200). This muscle is nearly spherical
and occupies a concavity slightly cephalad of the fenestra ovalis.
The fossa may be seen on a prepared skull. With scissors cut the
tendon of the muscle and then the dorsal part of the bony ring sup-
porting the membrana tympani, and carefully remove the malleus
adhering to the membrana. Note the rounded head of the malleus
and also the long flat process (processus gracilis) arising from the
lateral aspect of the neck.

§ 1437. Incus, anvil (Fig. 127).—This, the second of the chain
of bones, resembles a molar tooth with two divergent fangs rather
than an anvil (Quain, A, IT, 631). To expose it, remove the cephalic
part of the tympanum and the tensor tympani muscle. Examine

a

STAPES. 529

under a strong light with a magnifier. Note the larger part with its
concavity for articulation with the malleus and, extending ventro-
mesad, a slender process which articulates with the stapes. Con-
tinue to use the magnifier, and with a tracer sever the connection
with the stapes; then, by moving the incus slightly, it will be seen
to occupy the caudal part of an elongated fossa caudo-laterad of the
one occupied by the tensor tympani muscle. The shorter process
(fang) is held in position by a ligament. The cephalic part of the
fossa is occupied by the head of the malleus. Carefully nip away
the lateral wall of the tympanum and fully expose the longer pro-
cess of the incus and its ligament.

§ 1438. Stapes, stirrup (Fig. 127).—This is the third and last of
the chain of bones. (The so called Os lenticulare between the
stapes and incus belongs properly to the incus.) The narrow part
of the stapes, termed the head, articulates with the longer process
of the incus, and its broader part or base is inserted into the foramen
ovale. With the tracer or forceps move the bone slightly from side
to side, and there will be seen passing caudo-laterad the tendon of |
the M. stapedius. Remove the lateral wall of the tympanum, the
mastoid process, etc., around the Fm. stm. (Fig. 57), and the muscle
will be seen to originate near the aqueeductus Fallopii (§ 506) entad
of the 7th nerve. On the prepared skull the space occupied by the
stapedius may be seen to be separated from the fossa occupied by
the incus by a septum of bone. After the muscle is well made out,
grasp its tendon and pull gently. The stapes will be drawn out of
the fenestra ovalis. Note the small bony process on the caudal side
to which is attached the stapedius muscle.

LABYRINTHUS s, AURIS ENTALIS (INTERNA). (Fig. 127.)

§ 1439. Fenestra rotunda s. Fenestra cochlee ; Fenestra ova-
lis s. Fenestra vestibuli.—These two gateways to the labyrinth have
already been exposed. Note the membrane covering the fenestra
cochleee. The fenestra vestibuli was closed by the base of the
stapes and its connecting soft parts. These foramina open respect-
ively on the summit and side of the cylindrical cochlear eminence.

§ 1440. Cochlea.—The cochlea is situated mainly in the cylin-
drical elevation at the caudo-lateral aspect of which is found the
Fenestra rotunda s. cochlee. It consists obviously of the tapering
canals (scale) separated by a lamina of bone (lamina spiralis, Fig.
128). These scale are coiled about a central piece (modiolus), some-

34

530 ANATOMICAL TECHNOLOGY.

thing like the shell of a snail. The large end of the canal is visible
through the membrane covering the Fenestra rotunda, and, since it
faces into the tympanic cavity, is called Scala tympani. The other
canal opens into the vestibule and is called the Scala vestibuli.

To demonstrate the parts of the cochlea, rest the head on the
occiput, and with a watch-spring saw make a section across the
cochlear eminence so that the Fenestra vestibuli is divided in half.
If a watch-spring saw is not at hand, one may employ the nippers.
Remove the fragments made by the saw or the nippers by blowing
with the blowpipe. This will expose the vestibule, a cross section
of the cochlea and the opening of the scala vestibuli. The appear-
ance shown in Fig. 127 will be seen, except that the membranous
part of the septum may be torn. The direction of the cochlea
beyond the vestibule is nearly in a line, connecting the centers of
the foramen jugulare et ovale (Fig 57), and if the ventral wall of
the cochlear eminence be removed along such a line, the cochlea
will be exposed and a clear view obtained both of the Lamina spi-
ralis and the Modiolus or center piece around which the coils are
made.

To remove the ventral wall of the cochlear eminence, press a
blunt-pointed scalpel or arthrotome against the wall of the scala
tympani and pry carefully. Usually it will come off without the
least difficulty. The exposed cochlea will look like a cork-screw.
It should be remembered that in addition to the lamina spiralis
which forms a partition between the two scale, there will appear a
complete wall of bone separating the different whorls.

In the center of the modiolus is a cavity or canal, and the lamina
spiralis is perforated by many small holes, giving the appearance
of a sieve, and under the tripod it is seen that through these the
branches of the auditory nerve pass, to be distributed to the sentient
part of the cochlea. ‘

§ 1441. Canales semicirculares (Fig. 127).—There are three of
these, each forming about two thirds of a circle, in the periotic bone.
They are related somewhat as are related the three dimensions of a
cube, and open into the vestibule in pairs. From their position,
they are named as follows in man, and the terminology has been
retained for the cat: external, superior and posterior. The exter-
nal one (horizontal) is nearly in a dextro-sinistral plane and sur-
rounds a small fossa nearly caudad of the fenestra ovalis. The
superior one is in a dorso-ventral (vertical) transverse plane. It is

CANALES SEMICIRCULARES. 531

im the ridge forming the caudal boundary of the Fossa appendicu-
laris (Fig. 59, F's. ap.).

The posterior semicircular canal is in a dorso-ventral (vertical)
longitudinal plane, just laterad of the F'm. jgl. (Fig. 56). As stated
above, the canals open into the vestibule in pairs. The opening of
one end of the posterior and superior canals may be seen by look-
ing into the vestibule. The two other openings are situated near
the edge of the fenestra ovalis, one laterad and one mesad of the
opening just described. The mesal one is the common opening for
the posterior and external canals, while the lateral one is for the
superior and external canals. These three openings are situated in
a line connecting the middle of the Fm. jugulare and of the fenestra
ovalis (Fig. 57, Fm. j., Ft. ov.).

To trace these canals, remove the perioticum from the rest of
the skull, and, commencing at the central or common opening of
the posterior and superior canals, with the nippers and arthrotome
carefully remove the bony walls of the canal. To demonstrate all
the canals and their openings, one should take a skull, cleaned pref-
erably by maceration (§ 250), and after separating the perioticum
from the rest of the skull, remove the wall from the middle of the
length of the various canals (§ 1441), to expose them; then insert
fine bristles in both directions. In this way the three openings of
the canals may be found, and the ends of two bristles will be found
projecting from each opening.

§ 1442. Aquzductus cochlez.—This is a canal through the perioticum which trans-
mits a vein from the scala tympani. One opening of the canal is near the fenestra rotunda
and the other is just caudad of the Meatus auditorius internus(entalis). It may be readily
demonstrated by inserting a bristle into the scala vestibular opening. It is mentioned so
that it may not be mistaken for the opening of a semicircular canal.

For a sketch of the development of the eye and ear in the pig, see Hunt, D., 1; for
the external ear passages, 2 ; and for the development of the middle ear, 3.

Figure 127 was suggested by the diagram of the human ear given in Huxley and You-
mans, A, 195, Fig. 82. It is meant to represent the three parts of the ear in their relative
order. The first division or awris ectalis is removed, except the bony and a small part of
the cartilaginous meatus.

The bones of the ear were placed as nearly as possible in their proper position and
outlined with a camera lucida.

Explanation of Fig. 127.—Aquzductus cochlez (Aq. chl.).—A passage through the
petrosum for a vein from the scala tympani (§ 1442).

Canalis Eustachiana (Cn, Eu.).—The Eustachian canal opening into the cavity of
the tympanum or middle ear (§ 1435).

Canalis semicircularis posterior (P.).—This canal is represented in its whole length
and its opening at one end with the external and at the other with the superior canal.

532 ANATOMICAL TECHNOLOGY.

Fie. 127.—DIAGRAM OF THE CAT’s RIGHT EAR, VENTRAL VIEW; x about 5.

Canalis semicircularis superior (S.).—Only the beginnings of this are shown. One
of them commences in common with the posterior and one with the external canal (§ 1441).

Canalis semicircularis externa (E.). Only the beginnings of this canal are shown,
one of them opening with the superior and one with the posterior canal (§ 1441).

Cochlea.—This is represented as unrolled and the ventral surface removed so as to
expose the scale and the lamina spiralis (§ 1440).

Cutis, the skin.—It is continuous over the meatus and becomes very thin as it extends
over the membrana tympani to form its ectal layer.

Fenestra rotunda (Ft. rt.) s. Fenestra cochiea.—In life this is inclosed by a mem-
brane. It leads into the scala tympani of the cochlea,

Fenestra ovalis (Ft. ov.) s. Fenestra vestibuli—This is the passage from the tympa-
num to the vestibule. In life it is covered by the base of the stapes with its connecting
soft parts.

Incus.—The middle bone of the ear. It is also called anvil and dens molaris (§ 1437).

Labyrinthus.—This is the third and last or sentient part of the ear. It is often called
internal ear.

Lamina spiralis (Lm. spr.).—This is a plate of bone arising from the modiolus or col-
umn of the cochlea, and with its membranous continuation divides the cavity of the cochlea
into the two scale (Fig. 128).

Ligamentum incudis (Lgt. inc.)—The ligament holding one of the processes of the
incus to the wall of the tympanum.

Malleus.—The first of the small bones of the ear. It is by far the largest of the three.
It gains its name from its resemblance to a hammer. Its handle stretches partly across
the Mb. tympani.

Meatus.—The name is written in the meatus ectalis or passage from the exterior to
the membrana tympani (§ 1482).

TRANSECTION OF A COIL OF THE COCHLEA. 533

Membrana (Mb.) tympani.—The membrane is somewhat funnel-shaped as shown.
It is composed of three layers, the skin or cutis (see cutis), a fibrous central or intermediate
part and a continuation of the tympanic mucosa. The latter covers the handle of the
malleus and helps to bind it to the tympanum, and is only partly shown.

M. stapedius (M. stp.).—The name is connected with the bony process of the stapes to
which the muscle is attached (§ 1488).

M. tensor tympani (M. t. t.).—There is here shown the bony process of the malleus
to which the tendon of this muscle is attached (§ 1436).

O. lenticulare (O. Int.)—The small, nearly cylindrical bone between the stapes and
incus (§ 1438).

Petrosum s. perivticum.—The dense bone containing the parts of the labyrinth (§ 510). .

Scala vestibuli (Scl. vst.)—The chamber of the cochlea opening into the vestibule.
It is divided into two chambers by the membrane of Reissner (Fig. 128).

Scala tympani (Scl. tym.).—This chamber of the cochlea is separated from the tym-
panum only by membrane.

Stapes.—The last of the small bones of the ear. Its oval base fits into the fenestra
ovalis. Near its small end is a bony process, to which is attached the stapedius muscle.

Tympanum.—tThis is the second or middle chamber of the ear (§ 1484).

Vestibulum (Vst.).—The vestibule is the common chamber of the labyrinth ; from it
extend the semicircular canals and the scala vestibuli of the cochlea (§ 1431. C).

Explanation of Fig. 128.—Canalis cochlez (Cn.
chl.).—A division partitioned off from the scala vesti-
buli by the membrane of Reissner. It is separated .
from the scala tympani by the membrana basilaris
(Mb. bs.).

Lamina spiralis (Lm. sprl.).—This is the bony
partition between the two scale. The partition is
completed by the membrana basilaris (Mb. bs.). It
arises from the modiolus and through it passes the
Fic. 128.—TRANSECTION OF A _ cochlear nerve (N. chl.).

CorL OF THE COCHLEA, (From Membrana basilaris (Mb. bs.) s. lamina spiralis
Quain, after Henle.) membranacea.—This with the osseous spiral lamina
completes the separation between the scale.

The organ of Corti is on the side of this membrane toward the canalis cochlee ; no
attempt is made to indicate it here.

Membrana Reissneri (Mb. R..), s. lamina denticulata, s. limbus lamine spiralis.—This
membrane divides the scala vestibuli into two parts the canalis cochiew and the scala ves-
tibult proper.

APPENDIX.

TERMS OF DESCRIPTION (§ 1443)—NrIPPERS (§ 1444)—DROPPING-BOTTLE OILER (§ 1445,
Fig. 129)—LIQUID GELATIN (§ 1446)—OBTAINING ALCOHOL FREE OF Tax (§ 1447)—
DRYING JARS QUICKLY WITHOUT HEAT (§ 1448)—SOLUBLE BERLIN BLUE (§ 1449)—
BLUE GELATIN FOR INJECTIONS (§ 1450)—OBTAINING FROGS AND MENOBRANCHI
($$ 1451, 1452)—PITHING FROGS (§ 1453, Fig. 130)—MACROTOME (§ 1454)—BRAINS
OF LOWER VERTEBRATES (§ 1455)—UsE OF MICA (§ 1456).

§ 1448 (§ 23). Terms of Description.—In a notice of the senior
author’s paper (74) upon the brain of the cat, the Medical Record
(New York) for May 13, 1882, has the following :—

“ We feel disposed to especially endorse his recommendation for
the more general adoption of such terms as cephalic and caudal,
dorsal and ventral, in place of superior, inferior, posterior and
anterior. The latter are often rendered ambiguous and confusing
to the student on account of the natural difference in posture be-
tween man and other mammals, and the fact that the human
cadaver is usually. examined in a supine position.”

The American Journal of Neurology and Psychiatry (I, Feb.,
1882), in a notice of the same paper (pp. 101-104), and in other
notices and editorials (pp. 46, 50, 55), employs the terms cephalic,
ectal, ental, ventral, ventrad, dorsal, caudad, cephalad, caudo-
cephalad.

The same terms are consistently employed by Prof. T. B. Stowell
in his admirable paper (7) on the Vagus nerve in the cat, and by
our colleague, Prof. J. Henry Comstock, in his Report for 1880 (A)
as U. 8. Entomologist, and in his Guide to Practical Work in Ento-
mology (B) ; in the latter, Prof. Comstock has made valuable sug-
gestions respecting the whole subject of toponomy, especially with
regard to the use of cephalic and caudal.

§ 1444 (§ 146). Nippers.—Besides the ordinary surgical bone forceps, there are the

dental ‘‘ wedge-cutters,” which closely resemble the nippers, but are highly polished and
provided with a spring for separating the handles ; they cost about $3.25.

APPENDIX. 535

§ 1445 (§ 147). Dropping-bottle Oiler.—A bottle of the kind shown in Fig. 129, used
largely in microscopic work, is found to be a very convenient oiler. The glass tube is pre-
pared as directed for glass canule (§ 340), except
that its large end is slightly flared while hot by Rubber nipple
pressing it upon some blunt, pointed object. $3 ==
The bulb is a pure rubber nipple.

§ 1446 (§ 251, A). Liquid Gelatin. — The
liquid gelatin referred to is prepared as follows:
75 grams of the best translucent glue is put into
a clean towel and crushed with a hammer. It
is then placed in a fruit jar and 100 cc. of com-
mercial acetic acid poured over it. After stand-
ing three days or more in a warm place, there
should be added 100 cc. of water and 100 cc. of
95 per cent. alcohol. This preparation will re-
main liquid at the ordinary temperature of a
sitting room (20° C.). It should be of such a con-
sistency that when spread upon ordinary note
paper it will dry on the surface without pene-
trating the paper. If too thick, it may be thinned
by adding the liquids in the proportion given
above, or it may be thickened by adding glue.
This liquid glue or gelatin may be used like
common mucilage. Both are sometimes im-
proved by mixing them. The brush used must
be mounted in quill or something that will not
rust. A guill duster, with the addition of a
wooden handle, answers very well.

§ 1447 (§ 264). Obtaining Alcohol Free of
Tax.—(A) The original bill granted the privi- Fic. 129.—DROPPING-BOTTLE OILER,

Glass tube

lege only to incorporated or chartered institu- WITH DROPPING TUBE REMOVED ;
tions ; later provisions apply to all educational x 5.
institutions.

(B) In the application and the bond, the first name of each person named must be
written in full or an unmistakable abbreviation must be given.

(C) The bond must be executed for a sum equal to double the amount of tax due upon
the alcohol withdrawn.

§ 1448 (§ 333, A). To Dry Jars Quickly without Heat.—Clean them properly, rinse
them with rain (or distilled) water, and let this drain off. Then rinse with strong alcohol
and finally with ether. The evaporation of the latter will leave the surface perfectly dry.
Recommended by F. Lenggenhager in the Druggists’ and Chemists’ Circular.

§ 1449 (§ 336). Soluble Berlin Blue.—This form of Berlin blue is used laygely in
making fine injections and many experiments. Directions for preparing it are given in
nearly all the modern works on Microscopy, and, being so widely used, it has become
an article of commerce, and may be had of most dealers in microscopic materials. It
should be obtained in the solid form and a saturated solution prepared with distilled or
rain water. Such a solution may be used for a cold-flowing injecting mass (§ 1087), or it
may be mixed with glue as directed immediately below.

§ 1450. Blue Gelatin for Injections.—To prepare this, soak fine glue in clean cold
water until it becomes soft ; then transfer it to a metal dish and heat over a water bath

536 APPENDIX. ‘.
till the swollen glue melts. Add to this about an equal volame of the saturated Berlin
blue (§ 1449) solution heated'to about 80 or 90 Centigrade. Mix thoroughly, and if any
dirt is present, filter through fine flannel. The solution may be thinned with water. it
must of course be warmed when it is used, and the animal into which it is to be injected
should be warmed to at least 30° C. The material soon becomes moldy in warm weather,
so only about the amount needed should be made at a given time.

Injections with colored glue are made precisely as directed in § 359. After the injec-
tion is finished, allow cold water to flow upon the animal or set it away in a cool place,

§ 1451 ($§ 1085, 1091). Obtaining Frogs and Menobranchi.—Notwithstanding the
abundance of frogs in certain localities, they are not always obtainable when wanted for
anatomical and physiological purposes, and laboratories should keep a supply on hand.

Boys sometimes capture them, but are apt to injure them. Large frogs may some-
times be had from restaurants or from large dealers in fish lixe E. @. Blackford, of Fulton
Market, New York city. Frogs abound in the marshes near Montezuma, N. Y, and may
be had at a moderate price from Mr. Fennimore Helmer of that place.

Frogs may be transported long distances in a box of wet grass if a few airholes are
made. They should be kept in a spring, or ina dark covered tank or vessel through which
water flows, or in which it is frequently changed. The cover is needed both to prevent
their escape and to retard their vital changes. In spite of care, few survive more than
three months ; the larger ones often die within as many weeks.

§ 1452. Menobranchi abound in the lakes of central New York, but are not easily taken
with the net on account of the depth of the water, and the supply from that source is
therefore variable. We have usually been
able to obtain them in considerable num-
bers at short notice from Mr. Russel Dee,
of Harmar, Ohio. Menobranchi cannot
live long out of water, and the water should
be changed often. For transportation, not
more than three should be put in a pail of
water, and they should be shipped very
promptly. They may be kept easily in
aquaria, especially if a shelter is provided
under which they can screen themselves
from the light.

Alcoholic examples of the above named
animals, as well as of many other forms,
domestic and foreign, may be had from
the Natural History Establishment of Prof.
H. A. Ward, at Rochester, N. Y.

§ 1453 (§ 1086). Pithing Frogs.—
This is an expeditious and approximately
painless way of killing frogs for anatomical
and experimental purposes. The frog is to
be grasped as shown in Fig. 130—the pol-
lex upon the middle of the back, the me-
dius, annularis and minimus across the
belly so that their tips are related to the
right arm and leg as represented, and the index upon the head. In this way the most
active and powerful frog may be held securely, but the grasp may be aided by a bit of

BAA
bea

ii
Wo

Sess

ag

Fie. 180.—MEtTHOD OF HoLprne A FROG
FOR PITHING.

APPENDIX. 537
cloth. When first seized, the caudal end of the frog should be held downward or away
from the operator, so that the urine may not be discharged upon the clothes.

To pith, ventriduct the head with the index, and pass the tip of the right index from
between the eyes caudad until a distinct depression is felt at the meson, upon a line corre-
sponding nearly with the caudal margins of the membrane tympanorum. With a
sharp-pointed Charriére scalpel, divide the skin transversely for about 3 mm., and then
plunge the scalpel deeper so as to divide the ‘‘ medulla.” Respiratory movements cease,
and the frog is supposed to be dead and incapable of feeling.

If the cephalic portions of the brain are wanted, the head should be cut off and the
brain exposed without delay (§ 1087); or reflex movements of the limbs should be pre-
vented by breaking up the myelon with the probe or a piece of wire introduced from the
‘incision into the neural canal, ~

§ 1454 (§ 1115). Macrotome.—This name is applied to a simple apparatus upon which
sections of the head or other parts may be made with a saw. It is, in effect, a kind of
‘“miter-box,” and is made as follows :—

A block of hard wood (ash, oak, etc.),6 em. thick and about 18 cm. long, has a rebate
(“ rabbet ”) cut out along one of its long corners to a depth of 12 mm., and is then accu-
rately divided at about the middle of its length.

The pieces are then to be screwed securely across a perfectly level board, about 36x 18
cm., at about 10 cm. from one end. The pieces are to be separated by only the thickness
of the blade of the small back saw (§ 152) used in making the sections, and the rebate is
to be above, toward the shorter portion of the board.

At the right of the division between the blocks (or at the left if the operator is left-
handed) is to be placed a block about 4 cm. thiék ; it is to be adjustable by means of a
thumb-screw passing through a slot. In § 1117, this block is called the slide ; in some
cases it may be dispensed with.

The macrotome may be used not only for hemisection of the head, but also for making
frozen sections of limbs and other parts. The saw should be kept sharp, and clean but
not oily.

§ 1455 (§ 1871). The Brains of the Lower Vertebrates.—The brains of Amphibia
and of the air-breathing Vertebrates (Reptiles, Birds and Mammals) are readily compara-
ble with that of the frog or Menobranchus, But those of the “ fishes” (sharks, skates,
lamprey-eels, Ceratodus, gar-pikes and Teleosts) have not yet been homologized satis-
factorily, and the beginner is not advised to undertake their examination ; some idea
of the difficulties may be gained from the special papers by various writers upon the brains
of the several groups and from a brief summary by the senior author (26).

§ 1456 (§ 318). The Use of Mica for Mounting Alcoholic Specimens.—Prof. Leslie
A. Lee.has kindly called our attention to the use of slips of mica for the mounting in alco-
hol of preparations which require some support. It can readily be cut into the desired
shape, and holes can be drilled through which may be passed the threads for supporting
the specimen.

§ 1457 ($$ 1128, 1138, 1238). The Fornix.—According to an editorial in the Am. Jour.
of Neurology and Psychiatry (I, 402), there are two fornices, right and left, one for each
hemisphere, as there are two fimbria, etc. This commends itself to us upon some grounds,
but the commonly accepted view should not be hastily abandoned.

BIBLIOGRAPHY.

In the following Bibliography, the names of the authors are arranged alphabetically.
The books of an author are designated by heavy letters, and the papers by heavy Arabic
figures. Ifthe papers are recorded in the Royal Society’s Catalogue, the corresponding
numbers are herein given; otherwise they are numbered with heavy italicized
figures (§ 3).

The more common book sizes are indicated by the initials: F. (folio), Q. (quarto),
O. (octavo), D. (duodecimo).

The names of periodicals are abbreviated as in the Royal Society’s Catalogue.

The Arabic figures in ordinary type at the end of a title indicate the pages in the
present work where the book or paper is referred to.

General references to authors are given in the Index.

Agassiz, L.: A.—Contributions to the natural history of the United States. ‘On
Morphology and Nomenclature.” III. Chap. 2, Sect. 4....14.

Alcock, B. : A.—Article, ‘‘ The fifth pair of nerves.” Todd’s Cyclopedia of Anatomy
and Physiology, II, pp. 268-316. (This paper should have been referred to on p. 507.)

American Journal of Neurology and Psychiatry. . . .464, 482, 491, 508, 534.

Argyll, Duke of: 2.—A fourth state of matter. “ Nature,” June 24, 1880 ; 168. Repr.
in “Science,” July 17, 1880... .12.

Baker, R.: A.—Cursus osteologicus. Appendix on the preparation of bones. D.
London, 1699... .111.

Baley, T.: A.—A pocket book for chemists, chemical manufacturers, etc. 32mo, pp.
421. London and New York, 1878... .112, 136.

Balfour, F. M.: A.—A treatise on comparative embryology. Royal O., 2 vols., 429
fig. London, 1881... .8, 29, 32, 37, 41, 406, 410, 413, 416, 472, 478, 485, 487, 507.

Barclay, John: A.—A new anatomical nomenclature, relating to the terms which are
expressive of position and aspect in the animal system. O., pp. 182,5 plates. Edinburgh,
1803... .12, 21, 25.

Barnard, W. S.: 2.—Observations on the membral musculation of Simia satyrus
(orang), and the comparative myology of man and the apes. From the Proc. Amer.
Assoc., 1875... .193, 196.

Beale, L. S.: A.—How to work with the microscope. 0., pp. 518, 100 plates, 5th ed.
London, 1880... .197, 372.

Bell, Sir Chas. : B.—The anatomy of the brain explained in a series of engravings.
Q., pp. vii, 87, 12 plates. London, 1802... .472.

Bell, T.: A.—Article Carnivora. Todd’s Cyclopedia of Anat. and Phys. (g. ».), L
p. 480... .492.

BIBLIOGRAPHY. 539

Bernard, Cl.: A.—Legons de physiologie operatoire. 0., pp. 614, 116 fig. Paris,
1879....80, 144, 148, 192, 199, 200, 297, 316, 342, 363.

—— 17.—Memoir sur le pancreas. Supplément aux Comptes Rendus (1856)....
290, 291.

Bernstein, J. A.; A.—The five senses of man. D., pp. 301,91 fig. New York, 1876

. .512-514, 526,

Biches, X.: A,—Traité d’anatomie descriptive. 5 vols., D., 2517 pages. Paris,
1801-1803. Vol, III terminé-et publié par Buisson; IV par Buisson ; V par Roux....
53, 166.

Bigelow, M, T.; A.—Punctuation, and other typographical matters, for the use of
printers, authors, teachers and scholars. 16mo, pp. 112. Boston, 1881... .2.

Birdsall, W. R.: 1.—The embryogeny of the sympathetic nervoussystem. Archives
of Medicine, April, 1879. (This paper should have been referred to on p. 394.)

Bischoff, T. L. W.: 12.—Die Grosshirnwindungen des Menschen mit Beriicksich-
tigung ihrer Anordnung bei den Affen. Miinchen Akad. Abhandl. X. 1870, pp.
389-498... .435.

Bourgery et Jacob: A.—Traité complet de l’anatomie de ’homme. Paris, 1844.
(Vol. 8, neurology ; Vol. 8, embryology, including comparative neurology). ...316, 418,
419, 492.

Bowditch, H. P.: 2.—The collection of data at autopsies. Boston Med. and Surg.
Jour., 1880, CIII, p. 148... .136.

Broca, P.: 2.—Anatomie comparée des circonvolutions cérébrales ; le grand lobe
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1878, pp. 385-498... .499, 500, 503.

Brown, T.: A.—The taxidermist’s manual. 21 ed., D., pp. 149,6 plates. London
and Edinburgh, 1870... .111.

Bucknill and Tuke: A.—A manual of psychological medicine. O. London, 1858....
402.

Champneys, F.: 1.—On the muscles and nerves.of a chimpanzee (Troglodytes niger)
and Cynocephalus anubis. Jour. Anat. and Phys, VI, 1872, pp. 176-211... .193.

Chauveau: A.—Traité d’anatomie comparée des animaux domestiques. 2me edition,
O., pp. 992, 368 fig. Paris, 1871....152, 157, 161-163, 166, 167, 169, 174, 193, 194, 206,
212, 214,.215, 217, 219, 221, 223, 225, 229, 231, 236, 247, 250, 254-258, 260, 263, 265-270,
297, 303, 310, 311, 316, 342, 359, 363, 372, 379, 387, 394, 512-514, 526.

Chauveau (Fleming): A.—2d edition, translated and edited by G. Fleming. The com-
parative anatomy of the domesticated animals. 0O., pp. 957, 450 fig. New York, 1873....
152, 157, 161-163, 167, 174, 192, 206, 212, 214, 215, 217, 219, 221, 228, 225, 229, 231, 236,
247, 250, 252, 254-258, 260, 265-270, 297, 308, 310, 311, 316, 342, 363, 372, 379, 387, 394,
512-514, 526.

Clark, W. F.: A._-A manual of the practice of surgery. Revised and edited by an
American surgeon. O. New York, 1879... .86.

Cleland, John: A.—A directory for the dissection of the human body. D., pp. 175.
London, 1876....70, 192.
4.—On a peculiar ligament connecting the opposite ribs in certain vertebrata.
Edinb. Roy. Soc. Proc., IV, 1858, pp. 61-63... .166.
5.—On the structure, action and morphological relations of the ligamentum con-
jugale costarum. Edinb. New Phil. Jour., IX. 1859, pp. 258-266. . . .166.
7.—On the serial homologies of the articular surfaces of the mammalian axis,
atlas and occipital bone. Edinb. Phys Soc. Proc., Il, 1859-1862, pp. 221-226 ; Nat.
Hist. Review, 1861, pp. 151-154 ...169.

540 BIBLIOGRAPHY.

Cleland, John: 13.—On ribs and transverse processes, with a special theory of the
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——— 1.—A remarkable double monstrosity of the head. Jour. Anat. and Phys.,
XIII, 164-172 ; 2 plates. 1879... .22, 23.

Clevenger, S. V.: 1.—Cerebral anatomy simplified by comparative anatomy studies.
Chicago Med. Jour. and Examiner, Nov., 1880, pp. 9, 12 fig. .. .53, 500, 503.

—— 2.—Comparative neurology. Am. Naturalist, Jan. and Feb., 1881. . . .502.
8.—Plan of the Cerebro-spinal nervous system. Read before Amer. Assoc.
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Colin, G.: A.—Traité de physiologie comparée des animaux, etc. 2d ed., O., 2 vols.,
206 fig. Paris, 1871-1873... .365.

Comstock, J. H.: A.—Report of the Entomologist of the U. 8. Department of Agri-
culture for 1880, and in later reports. . . .534.

B —A laboratory guide in Entomology, Part I. 1882... .534.

Coues, E.: 36.—On the myology of the Ornithorhynchus. (1870.) Essex Institute
Comm. VI, 1871, pp. 127-178. . . .192.

—— 47.—Osteology and myology of Didelphys Virginiana. Boston Soc. Nat. Hist.
Mem. II, 1873, pp. 41-156. . . .57, 192, 193, 206.
1.—Antero-posterior symmetry, with special reference to the muscles of the
limbs. Medical Record, June—Nov., 1870... .22, 92, 192, 194.
2.—The nature of the human temporal bone. American Journal of Otology,
IV, Jan., 1882. (This paper should have been referred to on p. 174.)

Crooke, H.: A.—Mikrokosmographia, a description of the body of man. London,
1681... .197.

Cunningham, D. J.: 2.—The relation of nerve supply to muscle homology. Jour.
Anat. and Phys., Oct., 1881, XVI, pp. 1-9... .196.

Curtis, L.: 1.—On tactile hairs. Amer. Jour. Mic. and Pop. Sci., IV, 1879, pp.
166-172. . . .512.

Cutter, G. R.: A.—A dictionary of the German terms used in medicine. D., pp. 304.
N. Y., 1879... .16. :

Cuvier, Georges : A.—Lecons d’anatomie comparée, recueillies et publiées par Dumé-
ril, seconde édition, corrigée et augmentée. 8 volumes. D. Paris. [Tome troisiéme,
contenant le syst?me nerveux et les organes des sens, revu par MM. F. G. Cuvier et Lau-
rillard.] Paris, 1836-1846. ...169, 173, 192, 194, 297, 302, 303, 307, 310, 311, 316, 342, 363.
B.—Le régne animal, publ. par Audouin, Blanchard, Deshayes, Milne-Edwards,
Valenciennes, etc. 11 vols. de texte et 11 vols. d'Atlas, renf. 993 plehs. coloriées. Paris,
1849 et suiv. ...174, 474, 492, 499.

C,.—Legons d’anatomie comparée, recueillies et publiées sous les yeux de ]’au-
teur par MM. Duméril et Duvernoy. 0O.,5 vols. Paris, 1800-1805.—499.

Cyon : A.—Methodik der physiologischen Experimente und Vivisectionen. Royal 0.,
pp. 566, Atlas of 54 plates. Giessen, 1876... .418.

Dalton, J. C.: A.—A treatise on human physiology, for students and practitioners of
medicine. 7th edition, O., pp. 722, 252 fig. Philadelphia, 1882 ~..828, 887, 498, 505,
506, 508, 511-514, 526.
1.—Cerebral anatomy, with special reference to the corpus striatum. Annals
of the Anatomical and Surgical Society, II, pp. 1-18, 6 fig. Jan., 1880. Reprinted in
“ Brain”... .474.

Dana, J. D.: 123.—The classification of animals based on the principle of cephaliza-
tion. Am. Jour. Sci., XXXVI, 1863, pp. 315-321... .56.

Dareste, C.: 13.—Troisiéme mémoire sur les circonvolutions du cerveau chez les

BIBLIOGRAPHY, 541

mammiféres. Ann. Sci. Nat., III, 1855 (Zool.), pp. 65-111. Paris, Comptes Rendus, XL,
1855, pp. 683-686... .492, 499.

Darling and Ranney: A.—The essentials of anatomy. O., pp. 629, with figures.
New York, 1880... .173.

Dugés, A.: 4.—Note sur une nouvelle espéce d'axolotl ; le Siredon Dumérilii (1870).
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Dunglison, R.: A.—Medical Lexicon. A dictionary of medical science, etc. Edited
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Duval, M.: 1.—De la non-existence des trousde Monro. Progrés Méd. No. 25, p. 483,
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3.—Des plexus choroides et des trous de Monro. Comm. & la Soc. de Biologie,
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—-—— 4.—Developpement.de la région lenticulo-optique dans le cerveau humain.
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Duval et Keller: A.—See Huguenin: A.

Duvernoy, G. L.: 100.—Des caractéres anatomique des grandes singes pseudo-an-
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Dwight, Thos. : A.—The anatomy of the head, with 6 lithographic plates represent-
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B.—Frozen sections of a child. Q., pp. 66, 15 plates. New York, 1881... .131,

136, 339.

——— 1.—On the preservation of anatomical specimens. Publications of the Mass.
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Ecker, Alex. : B.—The cerebral convolutions-of man, represented according to crigi-
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Egleston, T. A.: A.—Tables of weights, measures, coins, etc., of the United States
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Eliot, C. W.: 2.—The new education. Atlantic Monthly, March and Feb., Vol.
XXIII, 1869, pp. 203, 358... .17.

Ferrier, D.: A.—The functions of the brain. O., pp. 823, 68 fig. New York, 1876,...
400, 475, 492, 500-502. x

Flint, A.: A.—A text-book of human physiology for practitioners and students of
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Flower, W. H.: A.—An introduction to the osteology of the mammalia. D., pp. 337,
126 fig. London, 1870....94, 152, 153, 157, 160-164, 167, 169-172, 174, 179, 184, 185, 183,
307, 316.

6.—On the brain of the Javan Loris (Stenops javanicus, Illig.). 1862. Zool. Soc.
Trans., V, 1866, pp. 103-111... .492, 502.

$.—On the optic lobes of the brain of the Echidna. Zool. Soc. Proc., 1864,
pp. 18-20, 2 fig. (This should have been referred to in § 1131 [8}.)

13.—On the commissures of the cercbral hemispheres of the Marsupialia and
Monotremata as compared with those of Placental mammals. Phil. Trans., CLV, 1865,
633-651, 4 plates. Abs. in Roy. Soc. Proc., 1865, 71-74 . 471, 473.

26.—On the value of the characters of the base of the cranium in the classifi-
cation of the order Carnivora, and on the systematic position of Bassaris and other dis-
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542 BIBLIOGRAPHY.

Flower, W. H.: 28.—On the anatomy of the Proteles.cristatus, Sparrman. Zool. Soc.
Proc., 1869, pp. 474-496... .499.

— 35.—On the anatomy of the Murus fulgens, Fr. Cuv. Zool. Soc. Proc., 1870,
pp. 752-769... .500.

36. —On the composition of the carpus in the dog. Brit. Assoc. Rep., XLI,

1871 (sect.), pp. 188; Journal of Anat. and Phys., VI, 1872, pp. 62-64 ...41. (This paper

should have been referred to on p. 161.)

41.—On the arrangement and nomenclature of the lobes of the liver in Mam-

malia. Brit Assoc. Rep., XLII, 1872 (sect.), pp. 150-151; Nature, VI, 1872, pp. 346-365
.. 286.

Ford, Corydon L.: A table of the cranial nerves. . . .510.

Forel, A.: 1.—Untersuchungen iiber die Hauben-region und ihre oberen Verkniip-
fungen im Gehirne des Menschen und einiger Siiugethiere. Archiv fiir Psychiatrie.
Berlin, 1877. (This and the following paper should have been referred to in § 1825.)
2.—Beitriige zur Kenntniss des Thalamus opticus und der ihn umgebenden
Gebilde bei den Siiugethieren. Sitzungsberichte der Kaiserlichen Akademie der Wissen-
schaften ; LXVI Band, 1 Heft, Juni 1872 ; S. 25-58, Tafeln 1, 2; 1872.

Foster, M.: A.—A text-book of physiology. 3d edition, D., pp. 804, 60 fig. New
York, 1880... .396.

Foster, M., and Balfour, F. M.: A.—The elements of embryology. Pp. 272, 71 fig.
16mo, Part I, 1874... .415.

Foster and Langley : A.—A course of elementary instruction in practical physiology.
3d edition, D., pp. 276. London, 1878... .7, 57, 316, 415, 500.

Frey, H,: A.—The microscope and microscopical technology. Translated and edited
by G. R. Cutter. 0O., 2d ed., pp. 624, 385 fig. N. Y., 1880... .280, 291, 298, 363, 367.

Fritsch und Hitzig: 1.—Ueber dié elektrische Erregbarkeit des Grosshirns. Arch.,
f. Anat., Phys. und Wissen. Med., Leipzig, 1870, 8S. 300-332 .. 500, 502.

Gadow, Hans: 3.—Observations in comparative myology. Jour. Anat. and Phys.,
XVI, pp. 493-514, July, 1882. (This paper was received too late for use on p. 196.)

Gage, S. H.: 1.—Plaster of Paris as an injecting mass. American Naturalist, Nov.,
1878, pp. 717-724... .57, 189, 148.
3.—The ampulla of Vater and the pancreatic ducts in the domestic cat, Felis
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180... .57, 292.

—— §.—The inter-articular ligament of the head of the ribs in the cat. Amer. Assoc.
Proc. , 1879, pp. 421-424... .166.
6.—Photographing natural history objects in a horizontal position. Read at
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Gall et Spurzheim: A.—Recherches sur le system nerveux en genéral, et celui du
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Galton, J. C.: 2.—Note on the epitrochleo-anconeus or unconeus sextus (Gruber).
Jour. Anat. and Phys., IX, 169-175, Pl. I... .193.

Ganser, S.: 1.—Vergleichend-anatomische Studien tiber das Gehirn des Maulwurfs.
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received too late for reference in the body of the work.)

Garner, R.: 7.—On the Brain of the Canide. Brit. Assoc. Rep., 1876, pp. 152-153

Gegenbaur, C.: A.—Grundriss der vergleichenden Anatomie. Leipzig, 1874. 0O., pp.
660, 320 fig. .. .22, 42, 174, 310, 394.

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Gegenbaur, C.: B.—Untersuchungen zur vergleichenden natom.e er Wirbelthiere.
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59.—Ueber das Archipterygium (1871), Jenaische Zeitschr. VII, 1873, pp. 130-

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Giacomini, C.: 7.—Nuovo processo per la conservazione del cervello. Communica-
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Gill, T.: 2.—Arrangement of the families of fishes. Smithsonian Miscellaneous
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Goodsir, J. : A.—Anatomical memoirs, edited by Wm. Turner. 2vols.,0., pp. 993, 14
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Gétte : A.—Die Entwickelungsgeschichte der Unke (Bombinator igneus). Leipzig,
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Gratiolet : A.—Memoire sur les plis cerebraux de homme et des primates. Q., pp.
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Giinther, A. C. L. G. : A.—An introduction to the study of fishes. 0O., pp. 720, 320
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Guillot, N. : A.—Essai sur le cerveau. Q. Paris, 1829... .499.

Gurlt, E. F. ; A.—Handbuch der vergleichenden Anatomie der Haus-siiugethiere. 5th
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Hadlich: 1.—Ueber die bei gewissen Schiideldifformitatiiten vorkommende Gehirn-
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Haeckel, E.: A.—The evolution of man: A popular exposition of the principal points
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Hammond, G. M.: 1.—A new cortical centre. Med. Record, Mar. 19, 1881, 309, 310,
1 fig. . . .492.

Harrison: A.—The Dublin dissector, or system of practical anatomy. 2 vols., D.,
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35

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182, 185, 189, 193-194, 207-208, 212, 214-217, 219, 221, 223, 225-226, 229, 231, 235-236,
238-241, 243-244, 247, 250, 252, 254-260, 263-271, 311, 313, 514, 525, 528.

B.—Traité pratique et theoretique d’anatomie comparative, comprenant l’art de
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Stricker: A—A manual of histology. 0O., pp. 1106, 431 fig. Translated from the
German. New York, 1872... .280, 281, 283, 285-287, 293-296, 303, 304, 306, 308, 311,
316, 362-363, 399-400, 472, 475-476, 482-484, 487, 490, 507, 512-514, 526.

Tait, P. G.: 2.—On the formula of evolution. Nature, Nov. 25, 1880. [Repr. in
“ Science,” Dec. 31, No. 26.]... .12.

Thacher, J. K.: 2.—The mesial and paired fins of fishes. Trans. of the Conn. Acad.
of Sciences. . . .23, 26. :

Tiedemann, F.: A.—The anatomy of the foetal brain, with a comparative exposition
of its structure in animals. D. Edinburgh, 1826... .492-498.

Todd, R. E.: A.—Cyclopedia of anatomy and physiology. 5 vols, O. London,
1835-1859... .413-415, 472.

14,.—Organology of the island of Reil. Proc. of N. Y. Neurological Soc., Jan. -

BIBLIOGRAPHY. - 5b

Treasury of Natural History: By Maunder; revised by T. 8S. Cobbold. 6thed. D.,
pp. 798, 900 fig. New York, 1872....111.

Turner, W.: A.—Article Anatomy. LEncye. Brit., 9th ed., Vol. I, 1875, pp. 799=908.

. .28, 316.

Turner, H. N. : 4.—Observations on the distinctions between the cervical and dor-
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United States Dispensatory, 18th ed... .112, 136.

Vicq d’Azyr: A.—Traité d’anatomie et de physiologie, avec des planches coloriées
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Von Baer: A.—Entwickelungsgeschichte der Thiere. 1828-37... .405.

Wadsworth, O. F,: 1.—Report on the decussation in the chiasma. Bost. Med. and
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Ward: A.—Article Saliva in Todd’s Cyclopedia of anatomy and physiology, IV, pp.
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Watts: A.—A dictionary of chemistry and the allied branches of the sciences. 0., 8
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Welcker, H.: 1.—Zwei Hiilfsmittel bei Demonstration des Gehirns und des Herzens.
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Westbrook, B. F.: 1.—Some: points in the anatomy of the encephalon. Annals of
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Wilder, B. G.: 1.—Contributions to the comparative myology of the chimpanzee
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10.—Intermembral homologies, the correspondence of the anterior and pos-
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37, 40, 42, 92, 167, 169, 192, 194. ;
11.—The outer cerebral fissures of mammalia, especially the carnivora, and
the limits of their homologies. Amer. Assoc. Proc., XXII, 1873, pp. 214-233, 4 plates....
57, 462, 465, 481, 491, 493-496, 498-500.
12.—Cerebral variation in domestic dogs and its bearing upon scientific phre-
nology. Amer. Assoc. Proc., XXII, 1873, pp. 234-249... .21, 56.
13.—Lateral asymmetry in the brains of a ‘double human monster. Amer, -
Assoc. Proc., XXII, 1873, pp. 214-234... .21. :

—— 17.—The need of a uniform position for anatomical figures. Amer. Assoc. Proc.,
XXII, 1873, p. 274... .31, 37.
18.—Lateral position of the vent in Amphioxus and in the larva of Rana
pipiens (catesbiana). Amer. Assoc. Proc., XXII, 1878, pp. 275-300, 10 fig. . . .21.
19.—On the composition of the carpus in dogs. Amer. Assoc. Proc., XXII,
1873, pp. 301-802, 3 fig. . . .161.
20.—The pectoral muscles of mammalia. Amer. Assoc. Proc., XXII, 1875, pp.
805-307... .18, 192-195, 285.

—— 21.—Variation in the pectoral muscles of domestic dogs. Amer. Assoc. Proc.,
XXII, 1873, p. 308... .56, 193. :

552 BIBLIOGRAPHY.

Wilder, B. G.: 2—Should comparative anatomy be included in a medical course ?
New York Medical Journal, Oct., 1877... .324.
2.—The anatomical uses of the cat. N. Y. Med. Jour., Oct., 1879, p. 16... .58,

56-58.
3.—The foramina of Monro: some questions of anatomical history. Boston
Med, Surg. Jour., CIII, Aug. 12, 1880, 2 pages....18, 57, 483.

4.—Notes on the anatomy of the cat’s brain. Read at the meeting of the
Amer. Assoc., 1879... .57, 414.

——— 5.—On the foramina of Monro in man and the domestic cat. Read at the
meeting of the Amer. Assoc., 1880. Partly reported in the Boston Daily Advertiser,
Aug. 380, 1880, and in the N. Y. Med. Record, Sept. 18, 1880. . . .57, 407.

—— 6.—A partial revision of the nomenclature of the brain. (Same as No. 5.). .. .57.

——— 7.—On the crista fornicis, a part of the mammalian brain apparently unob-
served hitherto. (Same as No. 5.)....57, 476.

S8.—The cerebral fissures of the domestic cat (Felis domestica). ‘‘ Science,” I,
No. 5, July 31, 1880, pp. 49-51, 2 figures. .. .57, 493, 495, 499-500.

9.—A partial revision of anatomical nomenclature, with especial reference to
that of the brain. “ Science,” II, No. 38, pp. 122-126; No. 39, pp. 133, 188 ; Mar. 19 and
26, 1881....11-13, 18, 25, 27, 37, 57, 405-407, 414, 472, 474, 477, 480-481, 483, 486-487, 489.

— 10.—The two kinds of vivisection, sentisection and callisection. Medical Rec-
ord, Aug. 21, 1880, p. 219. Reprinted in “ Nature,” Sept. 30, 1880, and in “ Science,” Oct.
23, p. 210... .80.

——— 11.—How to obtain the brain of the cat. “Science,” II, No. 41, April 9, 1881,
pp. 158-161. . . .18, 67, 423.
12.—Criticism of Spitzka’s “ Notes on the anatomy of the encephalon, etc.”
** Science,” No. 31, p. 48, Jan. 29, 1881. (Embodies a statement as to the dorsal limits of
the diaccelia.)....57.

——— 15.—On the brain of a cat lacking the corpus callosum. Presented at the
meeting of the Amer. Assoc. Adv. Sci., 1879, but not yet published. ...21, 57, 474.
14.—The brain of the cat (Felis domestica). A preliminary account of the
gross anatomy. Amer. Phil. Soc. Proc., XIX, pp. 524-562, 4 plates. Read July 15, 1881;
publ. Dec., 1881... ..57-58, 405-406, 414, 461, 472, 474-477, 480-481, 483, 486-487, 489,
493, 496, 498-500, 508, 534.
15.—On a mesal cusp of the deciduous mandibular canine of the domestic cat
(Felis domestica). Amer. Assoc. Proc., 1881, p. 242 ...189.

——— 17.—On a method of collecting and arranging information. Boston Proc. Nat.
Hist. Soc., May 15, 1867, p. 242... .52.
21.—Frozen sections of the cat preserved in alcohol. Read at the Amer.
Assoc., Aug., 1879... .131.
22.—On the brains of Amia, Lepidosteus, Acipenser and Polyodon. Amer.
Assoc. Proc., XXIV, 1874, pp. 168-185, 2 plates... .410.

——— 23.—An apparatus to show the action of the diaphragm in respiration. Boston
Soc. Nat. Hist. Proc., XX, 1870, p. 50... .310.
24.—Note on the ectal (“ apparent”) origin of the N. trigeminus in the cat.
Amer. Jours Neurology and Psychiatry, I... .508.

——— 26.—On the brains of some fish-like vertebrates. Amer. Assoc. Proc., 1876,
pp. 3, 5 fig... .537.

Williams, H. S. : A.—The bones, ligaments and muscles of the domestic cat. 0., pp.
86, with atlas of 12 folio plates. Copies, reduced one third, of the outline plates in Straus-
Durckheim’s A. The text is an explanatory index. New York, 1875....14.

BIBLIOGRAPHY. 553

Williams, H. S.: 1—Comparison of the muscles of the chelonian and human shoul.
der girdles. (1872.) Conn. Acad. Trans., II, 1871-78, pp. 801-308. . . .154.

Williams, T. ; A.—Article Respiration in Todd’s Cyclopedia of anatomy (g. v.). .. .810.

Witt, G. : A——Compendium of osteology ; appendix on preparation of bones. Folio.
London, 1838... 111.

Wood, J.: 7.—On human muscular variations and their relation to comparative
Anatomy. Jour. Anat. and Phys., I, 1867, pp. 44-59... .194.
9.—On a group of varieties of muscles of the neck, shoulder and chest, with
their transitional forms and homologies in the Mammalia. (1869.) Phil. Trans., CLX,
1870, pp. 838-116 ; Roy. Soc. Proc, XVIII, 1870, pp. 1-8... .215, 217, 228, 231.

Wyman, Jeffries: 34.—Anatomy of the nervous system of Rana pipiens. Smith-
sonian Contributions to Knowledge, V, Art. 4, 1855. Q, pp. 51,2 plates....2, 400, 402,
411, 413, 418-419, 421, 505.

——— 47 .—Dissection of a black chimpanzee (Troglodytes niger). Boston Proc. Nat..
Hist. Soc., V, 1854-56, pp. 274-275... .193.

—— 75.—On symmetry and homology in limbs. (1867.) Boston Nat. Hist. Soc.
Proc., XI, 1868, pp. 246-278. .. .92.

——— 76.—Observations on crania. Boston Nat. Hist. Soc. Proc., XI, 1868, pp. 440-
462... 174, 191.

Youag, ret: MET eo Wk of Viverra civetta. Jour. Anat. and Phys., XIV, pp.
166-177, Jan., 1880. . . .194.

In addition to our obligations to many of our laboratory students for useful hints
upon various points, we feel especially indebted to those named below, who have at our
suggestion investigated special parts of the cat’s anatomy for their graduating Theses :—_

Collins, Homer, class of ’82: The brachial flexor muscles in man, lion and cat.

Curtice, F. C., class of 81: A study of the tracheal region of the cat.

Dounce, G. A., class of ’79: Comparative myology of the shoulder of man and the cat.

Hoag, W. I., class of ’81: On the masseter and temporal muscles in the cat.
‘Manierre, C. "E. , class of ’80: The fourth cranial nerve in man and the cat. .

Schenck, H. D., class of 82: The distribution of the nerves to the muscles of the eye

in the cat..
Smith, Theobald, class of ’81: The peritoneum and its principal blood vessels in

the cat.
Young, J. H. W., class of "79: Comparative myology of the arm in man pee the mere

LDN AD, Tecate s

In the following. Index, technical words and words used in a technical sense are

accented with the principal accent.

In this, Webster’s Dictionary has been followed

whenever possible. There is also herein given the etymology of the technical terms not
found in the last edition of Webster’s Unabridged Dictionary.

Abbreviations for Parts of the Brain,
436-438

Abdo/men, a division of the trunk, 36.
ABDOM’INAL and thoracic viscera, lines of
incision for exposing, 274.

blood vessels, 355.
transection, how to do, 98-101.
viscera, 273-297.
Abdu’cens nerve, origin and distribution, 508.
Absorbent cotton, 62.
ACCESSORY or spinal accessory nerve, ori-
gin and distribution, 509.
parotid glands, 302.
Accuracy, limits to in description, 27.
Acous’tic or auditory nerve, origin and dis-
tribution, 508.
Actions of muscles, 202.
Action of the muscles of the eye, 519.
Ad'ipocere, 105.
Adjective and adverbial forms, 27.
Adrena’le, 295.
ADVERBIAL and adjective forms, 27.
ending, 27.
Air cells of lungs, 310.
AL’BA, functions of, 371.
structure of, 398-399.
white nervous matter, 369, 472.
Al'bicans, 472.
AL/COHOL, a perfect preservative, 113.
absolute, 112.
admission of into abdomen, 118.
anim required for different purposes,
21.
anatomical uses of, 112-124.
as a deodorizer, 83.
care of, 113.
changing the percentage of, 115-116.
coagulation of tissues by, 117.
cost of, 113.
crystalline deposits in, 123.
deterioration of, 122.

AL’/COHOL, determination of percentage of,
114.
economics of, 117.
filtration of for clearing, 122.
filtration of for deodorization and de-
coloration, 123.
how to obtain free of tax for scientific
purposes, 113, 535.
inflammability of, 114,
injection of into arteries, 119.
injection of into hollow viscera, 119.
injection of into lungs, 119.
injec ‘on of into thorax and abdomen,
118.
its importance and general character,
112.
measures accessory to immersion in,
117-119.
methyl, or wood spirit, 124. »
an of required for brains, etc.,
20.

percentage of required for ligaments,
etc., 121.
percentage of required for muscular
organs, 120.

precautions against fire from, 114.

purification of, 122-123.

reduction of with water, 116.

removing from hair, 131.

settling of for clearing, 122.

special characters of, 113.

specific gravities of various grades, 112.

strengthening of, 123.

use of appropriate grades of, 117.

vapor as a preservative, 123.

varieties of, 112.
Alcoholom’eter (alcoémeter), 114.
Alcoém/eter (aleoholometer), 114.
Alisphe’noid bone (Latin, ala, a wing, and

Greek, conv, a wedge, eidoc form), 181.
Alveolar margin of the jaw, 184.

INDEX.

Al'veus, lobulus hypocampe, 481.
American Metric Bureau, 5.
Amphibia, 8.
Amphibian brain, table of parts, 409.
Amphiox'us lanceola'tus, 10.
AMPULLA OF VA’TER, 292.
figure of, 291.
Anesthet/ic box and figure of, 81.
Analogies and differences of vascular and
nervous systems, 371-372.
Anapoph’ysis (avd, on, and gvevv, to grow or
be produced), 172.
ANATOM'ICAL instruments and mate-
rial, 59.
Philistinism, forms of, 204.
ngles of the eyelids, 514.
Angular gy’rus, 501.
An’gulus mandibula’ris, 188.
Animal charcoal, 83.
Animal charcoal for filtration of alcohol, 123.
An’nulus abdomina/lis exter’nus and inter’-
nus, 297.
ANTERIOR fissure of the spinal cord, 478.
perforated space, 485.
pillar of the for’ nix, 476.
AOR’TA, 338.
abdomina’lis, 358.
abdomina’lis, injection of, 147,
and its principal thoracic branches, fig-
ure of, 347.
thorac’ica, 350.
Apex of heart, 326.
APHORISMS for dissectors, 197-198.
general, 52-54.
respecting nomenclature, 12.
Aponeuro’sis, an undesirable name, 196.
Append/ages of the skin, 512.
Appendic’ular parts of the body, 25.
AQUADUC'TUS coch’lex, 531.
Syl’vii, 482.
A’'queous humor and aqueous chambers of
the eye, 522.
Arachnoi dea, 413, 472.
Ar’ bor vi'tx, 472.
Arched gy’ri, 500.
AR’CUS bicipita’lis, 245.
neura’ lis, 172.
A/REA crura’lis, 473.
crura'lis, diagram of, 447,
ellip’tica, 473.
intercrura’lis, 478.
ova’ lis, 4738.
postponti'lis, 473.
preechiasma’tica, 478.
septa’lis of brain, 473.
Areas and lines of muscular attachment, 195.
Areom/eter, 114.
ARM, cephalic or anterior limb, 29, 30.
muscles of, with figures, 225-271.
Arrangement of cranial nerves, 506.
ARTE’RIA adre’no-lumba’lis, 359.
anastomo’tica mag’na, 354.
axilla’ris, 352.

555

ARTE’RIA brachia’lis, 3538.
bra’chio-cephal’ica s; innomina’ta, 850.
bronchia’lis, 351.
cardi’aca, 826.
carotide’a, figures of, 345, 847, 392.
carotide’a, injection of, 148.
circumflex’a, 353.
circumflex'a anterior, 353.
ceeli/aca, 358.
co’lica dex’tra, 859.
co’lica me’dia, 359.
co’'lica sinis'tra, 360.
corona’ ria ventric’uli, 359.
cyst/ica, 358.
epigas’trica, 361.
femora’lis, injection of, 142,
gas’tro-duodena’ lis, 358.
gas’tro-epiplo’ica dex’tra, 358.
heemorrhoida’ lis supe’rior, 360.
hepat’ica, 358.
hypogas'trica, 361.
il’eo-co’lica, 359.
il’eo-lumba’lis, 360.
ili/aca exter’na, 361.
ili/aca inter’na, 361.
intercosta'lis, 351.
intercosta’lis superior, 351.
interos’seus ante’rior, 354.
interos’seus poste’ rior, 354.
lumba’ lis, 351, 362.
mesenter’ica inferior, 360.
mesenter’ica superior, 859.
nu’triens, 354.
cesophage’a, 351.
ova’ rii, 360.
pancreat/ico-duodena’lis, 359.
pancreat’ico-duodena’lis inferior, 359.
pericardi’aca, 351.
phren’ica, 358.
profun’da supe’rior, 354,
pulmona’lis, 326, 337.
pylor'ica, 358.
radia’lis, 354.
radia/lis recur’rens, 854.
rena’lis, 360.
sa/cra me’dia, 361.
spermat’ica, 360.
splen’ica, 359.
sterna/lis s, mamma/ria inter’na, 351.
subcla’via, 327.
subcla’via, branches of, 351.
subcla’via dex’tra, 351.
subcla’via sinis’tra, 350.
subscapula’ris, 353.
suprascapula’ris, 352.

* thorac’ica ante’rior, 352.
thorac’ica lon’ga, 352.
ulna’ris, 354.
ulna’ris recur’rens, 354.
ventric’uli dorsa/lis, 359.
vertebra’lis, 351.
vesica’lis supe’rior, 361.

Ar’teries, distinction from veins, 315.

556 INDEX,

AR’TERIES of the thorax and arm, 350.
of the trunk and arm, 343-344.
structure of, 363.
to inject, 142.
AR’THRON (dp8por, a joint), 166.
capitel'li, 171.
costicartilag’inis, 166.
il'io-sacra’le, 167.
mesosterne’ bri, 166.
of ribs, 165.
tuber’culi, 171.
AR’THROTOME (dor, a joint, and téuvew,
to cut), 62.
how to use, 201.
figure of, 66.
Articula’tions of bones of skull, 176.
Aspects of a vertebrate, figures of, 30.
Astrag’alus, 41.
Atlan'tal fora’men, 172.
At'las, 171.
Attachment lines and areas, 195.
Audi’'tion, hearing, 511, 526.
AU’DITORY apparatus, 526.
or acous'tic nerve. origin and distribu-
tion, 508.
AU'LA (Latin, a court-yard), 472.
and por’ta, 407, 454.
in frog, 422.
Auliplex’us (Zatin, aula, a court-yard, and
plexus, a twining or braiding), 473.
Aw'ricles of heart, section, 333-335, Fig.

93-96.
AURIC’ULA dex’ tra, 327.
sinis’tra, 327, 338. -
Auricula’ris mag’nus nerve, 301.
AU'RIS (Latin, the ear), 511, 526.
bones of, 528.
enta’lis, labyrinth’ us, 529.
media, 528.
Automat’ic nervous centers, 371.
Ax’'ial part of body (soma), 25.
AXIS, 171.
band or cylinder of nerve, 399.
ceeli’aca, 358.
thyroi’deus, 352.
AZ'YGOUS and paired, meaning of, 32.
lobe of the lungs, 310. -

Ball of the eye, globus oculi, 520,

Band axis of nerve, 399

Barnard, F. A. P., 5.

BASE of brain, figure showing segments and

nerve roots, 443.

of the heart, 327.

Basilar membrane of the coch’lea, 533.

Basioccip’ital bone (Latin, basis, the base,
oe occiput, the back of the head),

81. ote os

Basisphe’noid bone (Sacre, a base or pedes-
tal, cojv, a wedge, and eidoc, form), 181.

Batrachians, Amphibia, 8.

Beaded bristles, 63.

Belly or body of a muscle, 195.

1 Attn onan oie et <r,

Benzine, 81.
Berge, J. and H., 59.
Bicip'ital arch, 245.
Bicus’pid valves, 329-330.
Bigem’inum (Latin, double, twofold), 482.
Blackford, G., 475.
Bleaching bones, 110.
Bleeding as preliminary to preservation, 117.
Blind spot of retina, 522.
Blocks for dissecting, 64.
Blood-vascular system, 315.
Blood-vascular system, subdivisions of, 315.
BLOOD VESSELS, figure of general, 345.
in femoral region, figure of, 142.
isolating and drying, 346. -
ae of connecting when severed,
511.
of the trunk, 342.
of the trunk, figure of, 345.
structure of, 362.
Blow-pipe, care of, 74,
figure of, 66.
flexible, 64.
Blue for injections, 139, 535.
BODY cavities, dor’sal and ven'tral, 23.
figure of principal divisions, 38.
its primary divisions, 29.
of a vertebra, 172.
or belly of a muscle, 195.
planes of, 33
planes, figure of, 34.
table of principal divisions, 39.
Bone nippers, 62, 67.
Bone, structure of, 191.
BONES, bleaching of, 110.

cleaning by the liquid soap process, 106.

freeing them from grease, 110.
maceration in water, 105.
of limbs, 40.
of the ear, 528.
of young animals, preparation of, 109.
preparation of, 103.
removing soft parts from alcoholic spe-
cimens, 105.
soft parts removed by ants or Dermes-
tes, 105.
Borders of muscles, designation of, 197.
Bottle brush, figure of, 129.
Box, glass, figure of, 126.
BRA/CHIAL plex'us, 378-387.
plex’us, figures and diagrams of, 374,
378, 381. ;
Bra’'chium pon’tis, medipedunculus, 481.
BRAIN, abbreviations of names, :
and its fissures, 494.
and myelon, figure of dorsal view, 374.
cavities completely closed, 414.
coe’ lize or cavities, 406.
cee’ lize, exposed from ventral side, 440.
cee’ liz, figure of, ventral exposure, 440.
commissures of, 439.
comparison to a house, 413.
definition of, 400.

ao

INDEX. 557

BRAIN, exposure of, 377, 425.
exposure by removing calva, 431.
figure of the base, showing segments,
and nerve roots, 443.
figure of the mesal aspect, 446-447.
. figure showing the relations of the cav-
ities, 408.
figure of a transection through the dia-
ceelia, 458.
four plates of, with explanation, 461-471.
eneral considerations, 400.
ardening in alcohol, 429.
hardening with zinc chlorid, 435.
hemisection of, 444.
ideal, simple, 408, 409.
ideal, simple, diagrams of, 408.
importance and difficulty of its study,

injection of ccelize, 435.
its form, 493.
killing animal for, 423.
macroscopic vocabulary of, 436-438.
mesal aspect, showing segments, etc.,
446-447.
methods of study, 400.
names of parts, 403-404.
_ names, synonyms and references, alpha-
betically considered, 471-491.
of Amphibia, dissection of, 420.
of Amphibia, exposure of, 377.
of Amphibia, general inspection, 418.
of Amphibia, labeling, 418.
of Amphibia, preservation, 418.
of Amphibia, special methods, 428.
of cat, removal, 423.
of wee emente arrangement of names,

of cat and frog, differences of, 439.

of felines, figures by various authors,
with comments, 492-493.

of frog, advantages for study, 402.

of frog, exposure, 416.

of Menobranchus, description and dis-
section, 422.

of Menobranchus, exposure, 417.

of young human subject, method of re-
moval, 432.

plexuses, injection of, 436.

removal after hemisection of the head,
432-433.

segments, 404-406.

segments, examination of, 450.

segments in the cat, 439.

showing dorsal aspect of mesencepha-
lon, ete., 441.

study for comparative anatomist and
systematic zoologist, 401.

ta with brine while removing,

Table of parts in Amphibia, 409.
transferring to alcohol, 429.
ventricles of, cceliz, 406.
weighing, 429.

Brain, weight determined from capacity of
the skull, 191.

Brains, etc., percentage of alcohol required
for, 120.

Breneman, A. A., 123.

Brevity of technical terms, importance of, 15.

Brine for supporting brain, 125, 428.

Bristles, beaded, 63.

Bron’ chi, 311.

Bron’chial tubes, 311.

Bronchio’li, 311.

Brown, F. H., 8.

Bul’bus for’nicis, 472.

Bul’la tympan’ica, 185.

Cz'cum and Ileo-czcal Valve, 284-285.
Calca’neum, 41.’
Cal’car (Latin, a spur) part of brain, 478.
CALLO’/SUM (Latin, hard, firm), 489.
corpus, of brain, 474.
figure of its dorsal aspect, 442.
Cam/era, fornix, 479.
CANA’LIS bicipita’/lis, bicipital arch or
groove, 158.
centra’lis, of myelon, 406, 474.
cer ebro-spina’lis, 370.
coch’ lez, 500.
Eustachia’na, 185, 500.
lachryma’lis, 179, 500.
neura’ lis, 172, 370.
Schlem’mi, 500.
semicircula’ris, 500.
Canalic’ulus (Latin, diminutive of canalis, a
canal), 191.
Canalic’uli of bone, 191.
Can’thi or angles of the eyelids, 514.
CAN’ULA, inserting and securing, figure
of, 145.
introduction into vessels, 144.
of a syringe, character and preparation
of, 138.
CAPACITY of organs, determining, 135.
of skull, determining, 191.
CAP’ILLARIES, general character of, 315.
structure of, 363.
CAPITEL’LUM (Latin, diminutive of ca-
put, a head), 159.
cos' tz, 166.
hu’ meri, 159.
Cap’sula len’tis, 523.
CA/PUT (Latin, a head), 159.
hu’meri articula’re, 159.
Car’dia, heart, 316.
CAR’DIAC arteries, 326.
cavities, 3238.
CARE of instruments, 73.
of syringe, 137.
Cari’na for’ nicis, 474.
Carmine solution for injection, 139.
Carot'id artery, injection of, 148.
CAR’PUS and tar’sus, 41.
comparison with man, 41.
of lion and dog, figure of, 161.

558

Cat, advantages for study as compared with
the dog, rat, rabbit, etc., 56.
athe UE, data for ‘viene 46.
slip Agate of, 5
CATALOGUE library, ve
of manufacturers, 59.
Cau'da stria'ti, 474.
Cau‘dal and cephal’ic, use of, 23.
Cau’dal or tail vertebre, 170.
Caul, omentum, 280.
CAVITIES of the body, 33.
of the brain, importance and advantage
of for study, 401.
of the brain, communication with the
exterior, "401.
of the brain, completely closed, 414.
of the brain, names of, 409
of the brain, their relation, 413.
Ca/vum o’ris, 303.
Cel’la (Latin, a cell), me’dia, 474.
Cements for bones and teeth, 107.
Centigrade thermometer, 3.
CENTRAL canal of myelon, 413, 474.
“tubular gray, 475.
use and significance of, 26.
Cen’trum vertebra’le, 172.
Cephal'ic and cau’dal, significance and use
of, 23.
CEREBEL/LAR cine’rea, 475.
fos'sa, 186.
CEREBEL/ LUM, 474-475.
lateral lobe of, 481.
of frog, 419.
CER’EBRAL fos’'sa, 186.
peduncles, 476.
Cer’ebro-spi’nal nervous system, 369, 372.
CER’EBROUM and its fissures, 493-503.
its form, 493.
parvum, 474.
prosencephalon, 485.
CER’ VICAL nerves, 373.
vertebre and determination of, 170.
sdk yates division of the facial nerve,
1
Cer'vix of a rib, 166.
Chain hooks, 65.
Changes in terminology, objects and meth-
ods, 13.
Charcoal, animal, for filtering alcohol, etc.,

Charriére scalpel, 69.

Chaussiére, 15.

Chest, thorax, 308.

Chevron bones, 171.

Chias’ma (yiacuwa, the mark of the letter 7),
475, 507.

Chloral hydrate as a preservative, 124.

Chloroforming animals, 80.

Chie of origin and insertion of a muscle,

95.

Cholecyst/is (voA7, bile, neares, a cyst or
bladder), 277, 286, 289.

Chor’da spermat’ica, 143.

INDEX.

Chor’da spina’ lis, 372, 482.
Chor’ de tendin’ ez, 327.
Cho’roid plex’us of lateral ventricles, 485.
Choroi’dea, 521.
Chyle vessels, 364.
CIL/ LARY muscle, 525.
plice or folds, 522.
Cim’ bia, tractus transversus pedunculi, 475.
CINE’REA (Latin, of or like ashes), gray
nervous matter, 369-370, 475. -
functions of, 371.
of the brain, 475.
structure of, 898-399.
Clark, C. F., 64.
Class Mammalia, 8.
Classification of animals, Table of, 9.
Cla’va (Latin, a knotty branch), 475.
Clav'icle, clavic'ula, 56.
CLAVIC'’ULA, clav’ icle, 56.
determination of right and left, 150.
of cat, figured, 162.
Claw points, removal of, 102.
Claws as appendages of the skin, 512.
CLEANING bones, 103-111.
canula and syringe, 146.
Cleanliness, precautions for, 81.
Cleavage of muscles, 195.
Cleaves, Prof. E. C., vi, xxi.
Clements, Miss G. D., xxi, 461.
Clipping the hair, 204.
Coagulation of tissues by alcohol, 117.
Coarse injections of blood vessels, 187-148.
Coats of the eye, 521-522.
Coccyge’al nerves, 373.
COCH’LEA, 529.
canal of, 581.
scale and spiral lamina of, 529.
transection of a coil of, 5338.
Codman and Shurtleff, 79.
CQ LL (xorAia, a cavity), ventricles of the
brain, 406.
relations of, 413.
_ ventral exposure of, with figure, 440.
Coe’lum, trunk cavity, 37.
Col'lum, neck, 39, 307.
Co’lon, 285.
Colors for injections, 139.
COLUM’NA dorsa’lis (myel’onis), 475.
for'nicis, 475.
latera’lis (myelonis), 476.
poste’rior, 475.
ventra'lis (myelonis), 476.
vertebra’lis, 169-173.
Colum'ne car’nee, 327.
Columns of alba in the myelon, 370.
Combination of words, 28.
COMMISSU’RA ante’rior, precommissura,
484,
for'nicis, 476.
habena’rum, 476.
mag’na, callosum, 474.
me'dia s. mol’lis, medicommissura,

a =" we”

INDEX. 559

Commissu’ra_ posterior, postcommissura,
484,

Com’ missures of the brain, 407, 489.
Common ventricular cavity, aula, 472-473.
Compound words, connecting vowel in, 28.
Compressor, figure of, 65.

Conarial tube, 415.

Cona/rium («dvoc, a cone), pineal body, 420,

439. 476.

Conductive action of nerves, 371.
CON'DYLUS mandibula’ris, 189.
occipita’ lis, 183.
Conjuncti’ va, 514.
Connect, definition of term, 197.
Co’nus arterio’sus, 337.
Copperas as a deodorizer, 83.
Co’rium, derma, cutis vera, true skin, 512.
Corks and rubber stoppers, 126.
Cor’nea, 521.
COR/NU Ammo/nis, hypocampa, 480.
ante’rius ventric’uli latera’lis, preecor-
nu, 484.
me’dium s. descen’dens, medicornu,
481.
poste’rius, postcornu, 484,
Cor’onal suture, 183.
COR’PUS al’bicans, 472.
bigem’inum ante’rius, optici, 482.
bigem’inum poste’rius, postoptici, 484.
callo’sum, 474.

_can'dicans, albicans, 472.
fimbria’tum, fimbria, 478.
genicula'tum exter’num, 484.
genicula'tum inter/num, 484.
mammilla’re, albicans, 472.
pinea'‘le, conarium, 420, 489, 476.
pituita’rium, hypophysis, 480.
pyramida'le, pyramis, 485.
stria‘tum, 488.
trapezoi'des, trapezium, 490.
vit'reum, 522.

Corpus’cula Paci’ni, 281.
COR’ TEX (Latin, a rind), 440.
cer’ebri, 440. 475.
of the encephalon, 476.
Cor’ti, position of the organ of, 588.
Cos'ta, rib, 167. :
Cos’tal car’tilage, costicartila’go, 167.
COTTON, absorbent, 62.
filtration of alcohol through, 122.
COT’YLOID bone, 168.
fos’sa, 168.
CRA’NIAL fos’se, 186.
NERVES, 871.
comparison with spinal, 504.
method of demonstration, 511.
numbering, 505.
physiological arrangement, with Ta-
ble, 506.
Table of origin, exit, distribution and
functions, 510.
Table of synonyms, 505,
Cranium and face, 174.

Crib’riform plate of the ethmoid, 188.
CRIS’TA (Latin, a crest) deltoi’dea hu’ meri,
deltoid ridge, 159.
for'nicis, 476.
il’ii, 167.
lambdoida’lis, 179.
pectora’lis hu'meri, pectoral ridge, 159.
tempora’lis, 179.
CRU’CIAL FISSURE, constant and variable
characters, 498-499. ;
its homology and formation, 500-502.
Cru’ral area, 473.
CRUS ante’rius medul’le oblonga’te, 476.
gry supe’rius, prepedunculus,

ce’rebri, 476.
e cerebel/lo ad medul'lam, postpedun-
culus, 456.
for'nicis ante’rius, 4'76.
me’dium, medipedunculus, 481.
olfacto’rium s. rhinenceph’ali, 476.
Crys’'talline lens, 522.
Cuboi'des, 41.
Cu’neiforme, 41.
Curtis, Miss I. M., xxi.
Cusps of deciduous canines, 56, 188.
Cu'ticle, epidermis, 512.
CU’'TIS, skin, 512.
ve'ra, derma, true skin, 512.

DECAPITA’TION of a Cat for the
Brain, 423.
of a frog or Menobranchus, 415.
Decimal systems, 3.
Dee, R, 536.
Del’ta for’nicis, 477.
Del'toid ridge of the humerus, 159.
Deo'dorizers, 83.
Derivative words, formation of, 28.
Der’ma (dépua, the skin), cutis vera, true
skin, 512.
DESIGNATION OF organs, organonomy,
14.

pesition and direction, toponomy, 20,

the cranial nerves by numbers, 505.
DETERMINATION OF muscular homolo-
gies, 196.
right and left, 149.
right and left with entire limbs, 151.
the capacity of the skull, 191.
Deutenceph’alon (deirepoc, second, ?v, with-
in, xe¢aA7H, the head), diencephalon, 477.
Dex’tral and sinis’tral, use of, 24.
Diace'lia (dui, between, «oAia, a hollow),
third ventricle of brain, 477.
Diagonals of solids, designation of, 35.
Diagranis of ideal, simple brain, 408.
DIAPHRAG'MA, 277, 281, 311.
figure of caudal or peritoneal surface,
3138.
partition-between thorax and abdomen,
37.

560

Diaphrag’ma, tendons of, 311.
Diaph'ysis (d:¢, through or between, and
ove, to grow or be produced),
humeri, shaft of a bone, 158, 159.
Diaplex'us (dcé, through or between, and
Latin plexus, a twisting or braiding),
plexus of third ventricle, 422, 477.
Diapoph’ ysis of a vertebra, 172.
Diate’la (d:d, through or between, and Latin
- tela, a web), 477.
DIENCEPH’ ALON (é:a, between, év, with-
in, and xedad7, the head), 477.
examination, 452.
in Amphibia, 420.
Differences of brain of cat and frog, 489.
Direct lines, 34-35.
DIRECTION AND POSITION, designation
of, 20, 34. :
on direct lines, 35.
on oblique lines, 35.
Disarticulating skulls, 109.
Display of alcoholic specimens, 129.
DISSECTING gown, 65.
instruments, how to use, 199-201.
DISSECTION a fine art, 193.
of muscles, instruments and materials
for, 198.
of muscles, preparation of cat for, 198.
of the amphibian brain,
of the heart, 336.
of the brain, 450-457.
wounds, 85.
Dissections by beginners should not be
published without careful examination,

193.
DISSECTORS, aphorisms for, 197-198.
practical suggestions for, 201-203.
Dis’tal, significance and use of, 25.
DISTINGUISHING the groups of vertebre,
170.
vessels from nerves, 375.
Dividers, duplicating, 67.
DIVISIONS of the body, figures of, 30,

of a muscle, 195.
of the sensory nerves, 506.
DOR’SAL and ven’tral, use of, 24.
or thoracic vertebre, and determination,
170.
or upper eyelid, 514.
primary division of myelonal nerves,
3738.
primary division of nerves, demonstra-
tion, 377.
Double knot, 144.
Drawing materials, 67.
Drills, 67.
Dropping-bottle oiler, figure of, 535.
Drowning animals, 80.
Drying to be avoided in dissection, 203.
Duct of the parotid gland, 301.
of the submaxillary gland, 302.
Ducts of salivary glands, preparation, 298.

INDEX,

DUC'TUS arterio’sus, 328.
choled’ochus commu’nis, 287.
cyst/icus, 287.
hepat’ici, 287.
lachryma’lis, 516.
Santorini, 292.
Stenonianus, 301.
thorac’icus dex’ter, 365.
thorac’icus in sections of thorax, 342.
thorac’icus sinis'ter, 364,
thorac’icus sinis’ter, figure of, 366.
Whartonianus, 302.
Wirsungianus, 290.
Duode’num, 283.
DU’RA (mater), 477.
— from myelon and brain, 379,

EAR, Auditory Apparatus, 526-533.
auris, bones of, 528.
diagram of, 582.
ectal or external, 526.
ental (internal), labyrinthus, 529.
middle, or tympanum, 529.
muscles of, 528, 529.
semicircular canals, tracing of, 530.
Ear-pocket, 56.
EC'TAL (é«76c, outside, external), 27, 36.
and ental and their derivatives, 36.
and ental, significance and use, 27.
muscles of neck and shoulder, figure of,
211.
or external ear, 526.
Elimination of slips, 47.
Em’bryos, percentage of alcohol required
for, 120.
Emery, 76.
EMINEN’TIA audito’ria, 477.
lenticula’ ris, 488.
mag’ na cer’ebri, 490.
ENCEPHAULTC cavities, names of, 406.
segments, 404-406.
segments, examination of, 450.
segments in the cat, 439.
segments, unequal value of, 406.
ENCEPH’ ALON, definition, 400.
general considerations, 400.
vocabulary of parts, 436-438.
Endocar’ dium, 362.
En'dyma (‘vdiua, a garment), ependyma,
413, 478.
ENT’ AL (évréc, within, internal), 27, 36.
and ectal and their derivatives, 36.
and ectal, significance and use, 27.
En’terotome, 70.
Enumeration of parts in series, 42.
EPENCEPH’ ALON (ezi, upon, év, within,
xedadn, the head), 478.
examination of, 451.
Epen'dyma, endyma, 478.
Epicee’lia (evi, upon, and xocAia, a hollow),
fourth ventricle, 478.

| Epicon'dylus (evi, upon, and xévdiAoc, a

Eo *

—

——

INDEX. / 561

knob or head), external condyle of hu-
merus, 160.
Epider’ mis, cuticle, 512.
Epip'loon, 278, 280.
Epipodial’ia (evZ, upon, rotc, a foot), 41.
EPITROCH’LEA (ezi, upon, and rpoydia,
a pulley), 158, 160.
internal condyle of humerus, 160.
Epitroch’lear fora’men, 160.
Ergot, hippocampus minor, calcar, 473.
ERRORS “ interpretation in dissection,
194.
of manipulation in dissection, 193.
Ether, inflammability of, 114.
E’therizing animals, 80.
EUSTACHIAN canal, 185, 528.
valve, 330.
Examination of brain segments, 450.
Exhibition and storage of specimens, 125-
126.
EXPOSURE OF brain, 425.
frog’s brain, 416.
heart, 319.
the salivary glands and their ducts, 299.
EXTERNAL abdominal ring, 297.
auditory meatus, 184.
condyle of the humerus, 160.
EYE, action of muscles of, 519.
definition and situation, 514.
frozen sections of, 523.
hardening in alcohol for study, 521.
images formed by, 520.
muscles of, 516.
nerves of, 520.
oculus, and its appendages, 514.
of cat, dorso-ventral section, 523.
tunics or coats of, 521.
EYEBALL, form of, 520.
how to obtain of cat, ox or sheep, 520.
Eyelashes, absence of in cat, 514.
EYELID, third, action of, 515.
palpebra, 514.

Face and Cranium, 39, 174.
Fa’cial nerve, origin and distribution, 508.
Fahrenheit’s thermometer, 3.
Fallopian tube, relation to ovary and perito-
neum, 296.
Falx (Latin, a sickle), removal of, 428.
FAS'CIA, 196.
denta’ita, 478.
Fascic’uli of muscles, 272.
mag (Latin, a small bundle), cine’rea,
Fau’ces, 513.
Feline brains, comments on figures of, 491.
Fellow of the opposite side, platetrope, lat-
eral homologue, 32.
FEM’ORAL artery, injection of, 142.
blood vessels, figure of, 142.
vessels, injection of, 142, 146.
FE’MOR, 40.
determination of right and left, 151.

36

FENES'TRA (Zatin, a window), 184.
ova’lis, 184, 529.
rotun’da, 184, 529.
Fibril'le of muscle, 272.
Fi’ bro-cartila’ go-intervertebra'lis, 1'71.
FIB/ULA, 40.
determination of right and left, 151.
Fifth ventricle, pseudoccelia, 485.
Filter, earthenware, 123.
Fim’ bria, 478.
Fim’ brial fissure, 497.
Finder, tracer, 72.
Fire, precautions against, 114.
Fishes, injection of, 141.
FISSU’ RA ansa'ta, 478, 498.
ante’rior, 498.
Bichati, rima, 487.
callosa’lis, 497.
crucia’ta, its constant and variable char-
acters, 498.
crucia'ta, its homology and formation,
499.
crucia’ta, the name, synonyms with au-
thorities, 499.
dorsilatera’lis (myel’onis), 478.
dorsimesa’lis (myel’onis), 478.
fim'brie, 497.
hypocam’ pe, 497.
Sylviana, 498.
Sylviana, its constancy as compared
with the FF, rhinalis and postrhi-
nalis, 498,
transver’sa mag’na, rima, 487.
ventrilatera’lis (myel’onis), 478.
ventrimesa’lis, 478.
FIS’ per re cerebral, and gyri, study of,
94,
comparison with those of man and other
mammals, 502.
figure of the lateral and mesal aspects,
494.

formation of, 497.
four problems connected therewith, 497.
homology with those of man, 502.
list of the constant ones in the cat,
495-496.
of the cerebellum, 494.
pattern in the cat, 501.
promising lines of inquiry, 503.
relation to ental structures, 497.
relative depth, and method of determin-
ing and indicating on drawings,
495.
structural relations, with list, 497.
Table, with synonyms, 496.
FISSU/RAL PATTERN, constant charac-
ters, 501.
variable characters, 502.
Fleas, killing with benzine, 64, 80.
FLEXIBLE blow-pipe, 64.
specimens, how to preserve, 121.
Floc’culus, of the cerebellum, 478.
Folsom, 52.

562

Foltz, 42.

FORA’MEN atlanta’le, 172.
cx’cum, 478.
cona’rii, 479.
condyla’re, 183. .
epitrochlea’re s. supracondyloi’deum,
infundib’ uli, 479.
jucula’re, 183.
eo me’ dium, 183.

Monroi, porta, 483.
neura’le, 172.

obturato’ rium, 167.

of Magendie, 414.

of Monro, porta, 407, 421.
of Winslow, 280.

ova’le, of heart, 328.
palati’/num poste’ rius, 180, 184.
sphe’no-palati’num, 180.
sty’lo-mastoi’/deum, 183.
vertebrarteria/le, 171, 1738.

Foram/ ina of skull, Table of, 190.

FORCEPS, care of, 74.
coarse and fine, 67.
figure of, 66.
how to use, 201.

Form of the cerebrum, 493.

Formation of fissures, 497.

Forms of muscles, 196.

For'nix (Zatin, an arch), 479.

FOS’SA appendicula’ris, 180.
cxe'ca, 478.
cotyloi’ dea, 168.
mandibula’ris, 184,
olecrana’lis hu’ meri, 160.
orbita’lis, 180.
ova’lis, 328.
radia/lis hu’ meri, 160.
tempora’ lis, 180.
thyro-hya’ lis, 184.
ulna/ris hu’ meri, 160.

Fos'sx of skull, 186.

Fourth ventricle, metaccelia, 478.

Frazer, Persifor, 5.

Fresh specimens in alcohol should not
touch sides of jar, 121.

Frog ae Menobranchus, killing for brain,

15

BD:
FROG’S BRAIN, advantages for study, 402.
exposure, 416. j
From and of, use of with adverbs, 27.
FRON’TAL bone, 181.
sinus, 183.
FROZEN dissections, 132.
sections, method of making and pre-
serving, 131.
sections of the eye, 523.
sections of the thorax, 338-342.
FUNCTIONS of the alba, 371.
of the cinerea, 371.
FUNIC’ULUS (Latin, diminutive of funis,
a cord), grac’ilis, cla/va, 475.
of a nerve, 398.

INDEX.

Gaboriau, 53.

Gall bladder, 277, 286.

Gan’ glia, 369.

GAN’GLION cer’ebri posti/cum, 490.
cervica le supe’rius, 395.
hemispher’icum, 479.
infe’rius of vagus, 509.
jugula’re of vagus, 509.
petro’sum of glossopharyngeus, 509.
semiluna’re, 391, 396.

Ganglion’ic nervous matter, cinerea, 475.

General sensibility, 512.

Ge’nu (Latin, a knee), of the callosum, 479.

German technical terms, 16.

epee method of hardening the brain,

5.
Girdle, definition of term, 197.
GLANDS, sweat and sebaceous, 512.
lachrymal, 515.
GLAN’DULA (Latin, a gland) Harderi, 515.
lachryma‘lis, 515.
Meibo’miana, 514.
mesenter’ica, 280.
mola’ris, 302.
paro’tis, 301.
pinea’lis, conarium, 476.
sublingua’lis, 302.
submaxilla’ris, 302.
zygomat’ica, 803.
GLASS dishes and boxes for specimens, 126.
jars, 127, 128.
jars, cleaning, 128, 535.
GLO’/BUS OC’ULI, eyeball, 520.
form of, 520.
how to obtain of cat, ox or sheep, 520.
Glossopharynge’al nerve, origin, relations
and distribution, 509.
Glot'tis, gustatory structures in, 513.
Glycerin, 15 per cent., bottle for, 72.
Goodnow and Wightman, 59.
Gould, John Stanton, 72.
Grades of alcohol, use of appropriate, 117.
Gram, 4.
GRAY matter of the brain, 476.
nervous matter, cinerea, 475.
Grease, removal from bones, 110.
Groups, muscular, 194.
Gudden, 475.
Gul'let, esophagus, 308.
Gusta’tion, taste, gustatory sensibility, 513.
GY’RI and fissures, study of, 494.
angular, 501.
arched, 500.
designation of, 500-501.
oper’ti, 480.

Habe'na (Latin, a thong, that by which
anything is held), 479.

Haben’ula (Latin, a small thong), habena,
479.

HAIR, clipping the, 204.
disposal of, 204.
parting for incisions, 148, 304.

Ee ee ee

INDEX. 563

Hair, parts from which absent, 512.
Hairs, tactile, 512.
Hamerton, Philip Gilbert, 52.
Harder’s tear gland, 515.
Haversian canals of bone, 191. .
Head, figure of a hemiseection, 305.
aes 5 audition, auditory sensibility, 511,
HEART and blood vessels, structure of, 362.
a’ pex, 326.
appendix, auricular, 326.
base of, 327.
cardia, 316-338.
cavities and parts, diagram of, 323.
designation of regions, 318.
difference between right and left, 324.
dissection of, 336.
dorsal aspect, figure of, 317.
exposure of, 319.
figures of sections, 333-336.
form, normal position, size, 318.
general description, 317.
hardening in alcohol, 322.
injection with alcohol, 321.
injection with plaster, 316.
in sections of thorax, 339.
location of, 317.
physiologically double, 323.
preservation in alcohol, 321.
recognition of regions of, 318.
removal of, 319.
removal of blood from, 321.
separation from lungs, 320.
septum of, 329.
structure of its muscles, 362.
Table of parts, 322.
transection of auricles, 334.
transection of ventricles, 336.
ventricles of, 332.
Helmer, F., 536.
HEMICAR’DIA dex’tra, 328.
difference between right and left, 324.
Hemicer’ebrum, 479.
Hemisec’tion (#1, half, and Latin, secare, to
cut), of the brain, 444.

-Hemisep’tum (ju, half, and Latin, septum,

a partition), cer’ebri, 479.
Hemisphe’ ree, 475, 479, 485.
Hemispheres of frog’s brain, 420.

He’ par, liver, 277, 286.

Hepat’ic ducts, 287.

Hi'lum of kidney, 294.

HIPPOCAM’PUS major, hypocampa, 480.

. minor, calcar, 473. me
Holding scalpel, figures of ways of, 199, 200.
Hollow viscera, preparation of, 132.
HOMOL’OGIES, intermembral, 42.

muscular, determination of, 196.
Homology of the cerebral fissures of cat

and man, 502.
Hone, coarse and fine, 76.
Honing and stropping instruments, descrip-

tion and figure of, 76.

Horns or cornua of gray matter in the mye-
lon, 370.

Horns of the uterus. 296.

Human subjects, small, 55.

HU'’MERUS, 40, 157-161.
determination of right and left, 150.
figures of, 156, 158, 228.
figures showing muscular attachments,

228

general description, 157.
its anatomical head, 159.
its aoc neck not distinct in cat,
159.
its arthral or anatomical head, 159.
its diaphysis or shaft, 159.
of cat does not appear twisted, 158.
special mnemonics of, 152.
Hu’ mor a’queus and the aqueous chambers,
522.
Hybrid words, 28.
HYDROM’ETER, British, 114
jar for, 115.
specific gravity, 114.
HYPOCAM’PA (#76, under, xau77, curva-
ture), hippocampus major, 480.
dissection, exposure, etc., 455.
Hypocam’ pal fissure, 497.
Hypoglos'sal nerve, origin, relations and
distribution, 509.
HYPOPH’YSIS, derivation from the ali-
mentary canal, 415.
of Amphibia, 423,
pituitary body, 480.

Ideal, Simple Brain, with Diagrams,
408-409

Tl'eo-cze'cal valve, 284.
Tl’eum, 283.
Iliac crest, 167.
Il'io-pectine’al line and eminence, 169.
Il'io-sa'cral arthron, 167.
Tl'ium, 168.
Images formed by the eye, 520.
since for injection, figures of, 143-
144,
for thorax and abdomen, 274, Fig. 76.
INCISU’RA hypocam’pe, 480.
vertebra'lis, 173.
Inconsistencies of nomenclature in this
book, 19.
In’cus (Latin, an anvil), 528.
India ink, 67. . i
Inferior articulating process, 173.
Inflation of hollow viscera with air or alco-
- hol, 183-134.
Inflection of technical words, 27.
Infraorb’ital gland, 303.
INFUNDIB'ULUM (Latin, a tunnel or fun-
nel), of Berek sinus, 181.
of hypophysis, 480.
ingatial vino: 148, 297.
Inhib’itory centers, 371.
Injec’tion, choice of specimen for, 141.

564

a aa coarse, of blood vessels, 137-
1

incision in vessels for, 148.

making an, 145.

masses, 139.

of abdominal aorta, 147.

of brain cavities with alcohol or plaster,

435.
of carotid artery, 148.
of femoral vein, 146.
of femoral vessels, 142.
of heart with alcohol, 321.
of plexuses of brain, 436.
of postcava, 147.
of V. jugularis externa, 147.
time of making, 141.

Innom/inate bone, 168.

Innomina’tum, determination of right and
left, 150.

Insertion and origin of muscles, 195.

Instrument cases, 74.

IN/STRUMENTS and materials, anatomi-

cal, 59.

and materials for abdominal transec-
tion, 99.

and materials for the dissection of mus-
cles, 198.

dissecting, how to use, 199.

polishing of, 75.

sharpening of, 76.

value of, 62.

In’sula (Latin, an island), Reilii, 480.

Integers, muscular, 194.

Interartic’ular ligament of ribs, 165.

In'terbrain, diencephalon, 477.

Intercru’ral (Latin, inter, between, and cru-
ralis, belonging to legs), or interpedun-
cular space or area of brain, 473.

Intermediate, use of, 25.

Intermem’ bral (Latin, inter, between, and
membrum, a member), homologies, 42.

INTERNAL auditory meatus, 181.
condyle of humerus, epitrochlea; 160.

Interop’ticus (Latin, inter, between, and
érrixéc, relating to sight), 480.

Interpari’etal (Latin, inter, between, and pa-
ries, a wall) bone, 181.

Intestines, removing to avoid odor, 84.

INTESTI’NUM am’plum, 278, 285.
te/nue, 278, 283.

Intrinsic toponomy, 23.

Introduction of canula into vessel, 144.

Tris and pupil, 520.

Ts'chium, 168.

I'ter (Latin, a way), aqueduct of Sylvius, 480.

JARS for Specimens, figures of, 127.
and bottles, how to dry quickly, 535.

Jeju’num, 283.

Ju'gular vein, injection of, 147,

KID/NEY, Ren, 278, 294.
figures of sections, 293.

INDEX.

KID'NEY, relation to peritoneum, 279.
relative position, 294
sections of, 293.
structure, 294.
KILLING Amphibia, 415.
animals for dissection, 79.
cats for brain, 423.
x fleas with benzine, 80.
nots, surgeon’s and square, figures of, 144.
Kolliker, 37. .
Kreider, 8.

LA’/BELING Bones, 103.
brains of Amphibia, 418.

Labyrinth’us (Latin and Greek, a labyrinth),
ental or internal ear, 527.

LACH’RYMAL apparatus, 515.
bone, 181.
canal, 179, 515.
duct, 516.
sac, 516.

Lac’teals, 316, 364.

Lacu’ne of bone, 191.

LAMBDOID’AL crest, 179.
suture, 183.

Lamel’la ventra’lis, 172.

LAMINA cine’rea, 489.
cribro’sa, and figure of, 188.
denticula’ta, 5383.
fusca of sclerotica, 521.
neura’lis, 173.
spiralis membrana’cea, 533.
spira’lis of cochlea, 529-530.
termina’ lis, 489.

Lam/ ine, layers of muscles, 195.

Large intestine, 278, 285.

LATERAL homologue, platetrope, 82.
ligament of urinary bladder, 295.
use of, 24,
ventricle, 485.
white column of the spinal cord, 476.

Lead chlorid, 83.

Leakage of alcohol, 125.

Lean animals better for dissection, 198.

Lens of eye and its capsule, 522-523.

LIGAMENTS, etc., percentage of alcohol

required for, 121.
of the liver, etc., formed of peritoneum,
279.

LIGAMEN’TUM incu’'dis, 123.
interarticula/re cost, 165.
latera‘le of the urocystis, 295.
Poupartii, 143, Fig. 39.
suspenso’/rium of lens, 523.
suspenso’rium of urocy’stis, 294.
uteri, 296.

Ligatures, 144.

LIMBS, 25, 29.
bones of, 40.
designation of direction and relative po-

sition, 35.
designation of regions, 25.
normal position of, 37.

INDEX.

Limbs, segments of, 40.
Lim’ bus (Zatin, a hem), lamina spiralis, 532.
LI’MES (Zatin, a path), 480.
al’ba (of rhinencephalon), 480
cine’rea, 3
LIMITS of accuracy in description, 27, 49.
of terminological change, 18.
LINES ee areas of muscular attachment,
a.
of incision for exposing the thoracic and
abdominal viscera, 274
Lin’gua, tongue, 512.
Liquid soap, 106.
Liq'uor ccelia’rum, liquid in the ventricles
of the brain, 480.
Liter, 4
Liver, hepar, 277, 286.
LOBES of the liver, 286.
of lungs, 310.
LOB/ULUS appendicula’ ris cerebel’li, 480.
cor’ poris stria’ti,
hypocam’pe, 481.
LO’BUS latera’lis (cerebelli), 481.
olfacto’rius, in frog and other verte-
brates, 420.
olfacto’rius not a nerve, 507.
olfacto’rius, olfactory bulb, 481.
op’ticus, 482.
prosencephal ‘icus, 479.
tempora’ lis, 481.
LO’CUS perfora’tus ante’rior, 485.
perfora’tus pos’'ticus, 484.
LUM’BAR nerves, 372.
vertebrz and determination of, 170.
Luna’re (Latin, Luna, the moon), 41.
LUNGS and lobes of, 310.
and tra’chea, figure of, 310.
protection of in removal, 320.
separation from the heart, 320.
Lymph vascular system, 315-316.
LYMPHAT'IC glands, 316, 365-368.
glands, injection of, 367.
vessels, injection of, 367.
LYMPHAT‘ICS, 316.
comparison with veins, 316.
of the arms and legs, injection of, 367.
of the neck and face, injection of, 367.
structure of, 363.
Ly'ra, 481.

Macera’tion of Bones in Water, 105.
Ma'cula (Latin, a spot), lutea of retina, 522.
Magnifier, tripod, figure of, 72.
Ma’lar bone, 181.
Malinverni, 474.
Mal'leus (Latin, a hammer), 528.
Malo’dorous parts, 84
Mammalia, class, 8.
Mammilla’re, albicans, 472.
Mam’millary process, 173.
Man’dible, lower jaw, figures of, 188, 189.
MANDIB'ULAR condyle, 189.

division of the 5th nerve, 508, 510.

565

Manuscript, steps in the preparation of, 51.
Mar’ go alveola’ris of the jaw, 184.
Matches, care of, 114.
Mate’rials and instruments, anatomical, 59.
MAX’ILLARY bone, 181.
division of the 5th nerve, 508, 510.
MEA'TUS (Latin, a passage), audito’rius
ecta’lis (exter’nus), 184, 527.
audito’rius enta’lis {inter’ nus), 181, 509.
ventra’lis of nose, 306, 513.
Mediasti’num, 339.
Medicommissu’ra (Latin, medius, intermedi-
= - commissura, a joining togeth-
MEDICOR’NU (Latin, medius, intermediate,
and cornu, a horn), 481
cornu medium, 481.
opening, 455.
transection of, 458.
Medipedun’culus (Latin, medius, interme-
diate, and pedunculus, a small foot),

1.
MEDULLA (oblongata), 400, 482.
in Amphibia, 419.
spina’ lis (myelon), 482.
Med'ullary sheath, 369.
Med‘ullated nerves, 398.
Meibo’mian glands, 514. <
Mem/’bra, limbs, 29.
MEMBRA’NA arachnoi'dea, 472.
basila’ris, of cochlea, 533.
nic’'titans, action and use, 515.
Reissneri, 583.
Schneideriana of nose, 513.
tym/pani, 527, 533.
vasculo’sa cer’ebri, 483.
Me’ninx vasculo’sa (ujviyg, a membrane,
and Latin, vasculum, a little vessel),

483.
MENOBRANCHUS and frog, killing, 415.
brain of for study, 403.
distinguishing male and female, 418.
exposure of brain, 417,
Mental symphysis, 189.
MES’ AL (méz’al) ; barb i 24,
t of the brain owing segments,
pers 446, 447,
incisions, objections to, 202.
oH azygous organs, 43.
ificance and use of, 24.
MESEN CEPH’ ALON (uéooc, srs ta év, in,
and xedaA7, the head), 48
figure of dorsal aspect, 441.
in frog and Menobranchus, 419.
Mesenter'ic glands, 280.
Mesente’rium, mesentery, 278-279,
Mesocee'lia (uéooe, middle, and xo:Aia, cav-

Mes’on (méz! on); (76 uécov, the middle),25,33.

copie bags ia (uecoc, middle, and rovc, a
foot), 4

Mesorec’ He 279.

566 INDEX.

Mesostern’ebra (uéooc, middle, and ortépvor,
the sternum), 167.

Metacce'lia (wera, after, xovAia, a hollow),
fourth ventricle, 419, 482.

Metaplex’us (werd, after, and Latin, pleaus, a
twining or braiding), 482.

oe (uerd, after, rode, a foot), 41,

Metapoph’ysis (werd, after, a76, from, and
ove, to grow), 173.

Metate'la (uerd, after, and Latin tea, a web),
482.

Metal boxes and cans for specimens, 126.

METENCEPH’ALON (weru, after, év, with-

in, and xedad7 the head), 419, 482.

examination of, 450.

METER, 4
yard, figure of, 6.

Methods, importance of, 58, 55.

Meth’y] alcohol, 124.

METRIC and inch measures, figure of, 6.
and other measures compared and re-

duced, 7. :

and other systems, comparison, 5.

METRIC SYSTEM, 4.
how to learn, 6.
in medicine, 8, 15.

Midbrain, mesencephalon, 481.

MIDDLE ear, tympanum, 527.
or medi-ven’tricle, 477.
plane (meson), 24, 33.

Mitral valves, 380.

Mod/erator band of heart, 330.

Modi/olus (Latin, the nave of a wheel), of
the cochlea, 529.

Molar gland, 302.

MO’ a as sensory nerves and roots, 370,

root of 5th nerve, 507-508.
Mouth cavity, 303.
sceenar designation of the borders of,
7

ectal me neck and shoulder, figure of,
211.

forms of, 196.

instruments and materials for the dis-
section of, 198.

method of description, 206.

names of, 206.

of arm and scapula, figures of, 254, 262.

of ear, 528, 533.

of eye, 516.

of eye, action, 519.

of eye, nerve supply, 520.

of eye, origin, 519.

of left shoulder, figure of, 246.

of neck and shoulder, figure of second
layer, 218.

origin and insertion of, 195.

parts of, 195.

pectoral, figure of, 234.

structure of, 272.

the study of, Chap. VI, 192-272.

Muscles, twisting of, 197.

MUS’/CULAR fibers, 272.
groups, 194.
homologies, determination of, 196.
integers discussed, 194.
organs, percentage of alcohol required

for, 120.

subdivisions, 195.
variations, 1938. —

MUS'CULUS, definition of, 194.
acro’ mio-deltoi/deus, 256.
acro’mio-trape’zius, 214.
bi’ceps, 266.
brachia’lis, 267.
choanoi’deus, 519.
cilia’ris, 525.
cla’ vo-deltoi’deus, 231.
cla’vo-mastoi’deus, 228.
cla’ vo-trape’zius, 215.
coracoi’deus, 250.
der’‘mo-humera’lis, 225.
ec’ to-pectora’ lis, 235-241.
ec'to-tri’ceps, 263.
en’to-pectora lis, 241-244.
en’to-tri’ceps, 263-265.
epitrochlea’ris, 259.
exten’sor (car’ pi) radia/lis bre’ vior, 269.
exten’sor (car’pi) radia’lis lon’ gior, 268.
exten’sor (car’pi) ulna’ris, 270.
exten’sor (di’giti) min’imi, 270.
exten’sor (digito’ram) communis, 270.
flex’ or (car’pi) radia’lis, 271.
indicator, 271.
infraspina’tus, 257.
latis’simus, 229.
leva’tor an’culi scap/ ule, 250.
leva’ tor clavie' ule, 223.
leva’tor pal’ pebree, 518-519.
meditri'ceps, 260.
micosta’lis s. te/res mi/nor, 258.
obli‘quus dorsa’lis (superior), 518-519.
obli’quus ventralis (inferior), 517, 519.
occip/ito-seapula’ris, 217.
orbicula’ris palpebra’/rum, 516, 519.
pec’to-antebrachia’ lis, 236.
platys’ma-myoi'des, 227.
prona’tor te’res, 271.
pterygoi’deus, 525.
rec'tus dorsalis (superior), 518-519.
rec'tus latera’lis (externus), 517, 519.
rec/tus mesa/lis (internus), 518-519.
rec'tus mi/nor, 519.
rec’/tus poste’rior, 519.
rec/tus ventra’lis (inferior), 519.
rhomboi'deus, 219.
serra’tus mag’nus, 247.
spi’no-deltoi’deus, 255.
spi’no-trape’zius, 212.
stape’dius, 529, 533.
ster’no-mastoi deus, 221.
subscapula’ris, 252.
supina tor Jon’gus, 265.
supraspina’tus, 254.

— we

INDEX. _ 567

MUS'CULUS suspen’sor oc’uli, 519,
ten/sor tym’pani, 528, 533.

te’res, 258.

trochlea’ris (dorsal or superior oblique),
518-519.

xiph‘i-humera’ lis, 244,

Museum catalogue data, 46.
Myelencephal’ic nervous system, 369, 372
My’elin (uve2.6c, marrow, fat), 369, 398.
MY’ELON (uveAdc, marrow), the spinal cord
or spinal marrow, 19, 372, 482.
in Amphibia, 419.
MYEL‘ONAL alba and cinerea, 370.
nerves, 373.
MYOL’OGY, general considerations upon,
192-194.
technical terms of, 194-197.
the study of the muscles, Chap. VI,
192-272.

NAMES and Abbreviations on the Fig-
ures, 20.
indicating relative position, 17.
of brain, segmental arrangement of, 446.
of muscles, sources, 208.
Na’sal bone, 181.
Na’sus, nose, 513.
Na’'tis cer’ebri, opticus, 482.
NATURAL skeletons, flexible, 109.
skeletons, preparation of, 108.
Neck (part of soma), 307.
NERVE cells, 399.
fibers, anastomoses, 399.
roots shown in figure of the base of the
brain, 448.
supply of the muscles of the eye, 520.
NERVES, comparison of cranial with my-
elonal, 504, 506.
connection with the limbs, 500.
cranial, general considerations, 371, 504.
cranial, method of demonstration, 511.
cranial, numbering, 505.
cranial, physiological arrangement, with
Table, 506.

cranial, Table of origin, exit and func-.

tions, 510.

cranial, Table of the synonyms, 505.

distinguishing from vessels, 375.

figure of a transection of the thorax,
showing the relation of the cerebro-
spinal and sympathic, 397.

medullated, 398.

motor and sensory, 370.

non-medullated, 399.

of the face, 301.

subdivisions, 369.

termination of, 372.

NERV’OUS and vascular systems, analogies

and differences, 371-372.

matter, structure, 398, 399.

plexuses, 370

Sa central and peripheral portions,

NERV'OUS system, general directions for

dissecting, 375.

system, primary divisions, 369.

NER’VUS abdu'cens, origin and distribu-

tion, 482, 508.

accesso’rius (XI), 377, 389, 509. —

audito’rius, origin and distribution, 508.

auricula’ris mag’nus, 301

circumflex’ us, 385.

cuta’neus inter’nus, 384.

facia’ lis and audito’rius, 427.

facia’lis, origin and distribution, 508.

gas'tricus dorsa'lis, 391, 509.

gas'tricus ventra’lis, 390, 509.

glos’so-pharynge’us (IX), 389, 509.

glos’so-pharynge’us, va’gus and acces-
so’rius, relations, 426, 509.

hypoglos’sus (XII), 389, 426, 509.

interos’seus poste’ rior, 386.

Lancisi, 488.

larynge’us recur’rens, 388, 390, 394, 509.
ge’us superior, 509.

maxilia’ris supe’ rior, 508.

me’dius, 385.

mus’culo-cuta’neus s. cuta’neus exter’ -
nus, 384.

mus’culo-spira'lis, 386.

oc’ ulo-moto’rius, 507.

oc’ulo-moto’rius, trochlea’ris and abdu’-
cens, relations, 427.

olfacto/rius of Amphibia, 420.

olfacto/rius, 507.

op’ ticus, 507.

phren’icus s. diaphragmat’icus, 383.

pneu’ mo-gas'tricus (vagus), 387, 509.

splanch’nicus, 395.

subscapula’ris, 384.

suprascapula’'ris, 383.

sympath’icus, sympatheticus, 394.

sympath’/icus in the abdomen and tail,
396

thorac’icus ante’rior, 382.

thorac'icus poste’rior, or external respi-
ratory of Bell, 387.

trigem’inus, and its three divisions (1st
or ophthalmic, 2d or maxilla’ris, 3d
or mandibula’ris), 508.

ere ea its ganglion (Gng. Gasseri),
508.

trigem’inus, its motor root, origin and
distribution, 507-508.

trigem’inus, sensory root, origin, 508.

trochlea’ris, 507.

ulna’ris, 386.

va'gus, dissection of, 388.

va'gus, pneumogastricus, origin, distri-
bution and relations, 387, 388, 509-
510.

NEU’RAL and visceral cavities, 33.

arch, 172.

canal, 172.

fora’men, 172.

lam‘ina, 173.

568

Neu’ral spine, 173.
Neurol/ogy, general considerations, 369, 398.
Nichols, Wil iam, 48
Nictita’ting membrane, 515.
NIPPERS (bone), 62, 67, 534.

care of, 74.

cross-cutting, 68.

figures of, 62-63. :
NOMENCLAT’ URE, inconsistencies of in

this book, 19.

or terminology, 10.
Nom/ina impudi’ca, objections to, 15.
Non-medullated nerves, 399.
NORMAL POSITION, 21.

of limbs, 37.
Nose, nasus, 513.
NOTES, cost of material for, 50.

distribution of, 48.

elimination of, 47.

proper, 47.

slip system of, 45.

storage of, 48.

subdivision of, 48.
Nucleus cauda/tus, stria/tum, 488.
Numbering the cranial nerves, 505.

O’bex (Latin, an obstacle), 482.
OBLIQUE lines, 35.
muscles of the eye, 517-518.
Obtura’tor fora/men, 167.
Occip’ital con’dyle, 183.
Oc’ulo-mo'tor nerve, 507.
OC’ULUS (Latin, the eye), eye and its ap-
pendages, 514.
frozen sections of, 523.
hardening in alcohol for study, 521.
images formed by, 520.
muscles of, 516.
section, figure of, 523.
tunics or coats of, 521.
Odon’toid process of axis, 172.
Odors, perception by olfactory nerves, 513.
C&soph’agus, gullet, 308.
Of and From, use of with adverbs, 27.
Oil-stone, coarse and fine, 77.
Oiler, 68, 535.
Olfac'tion, olfactory sensibility, smell, 513.
OLFAC’TORY fossa, 186.
lobe or bulb, 481, 487.
lobes, examination of, 450.
nerves, distribution to the nose, 513.
nerve or tract, 476.
Oli’va (Latin, an olive), area elliptica, 482.
Omen’tum, 278, 280.
Ophthal’mic (1st) division of the trigeminus
nerve, 508, 510.
OPTIC chiasma, 475.
nerve, origin, 507.
tract, 490.
Op’ticus (lo’ bus), 482.
O’ra serra'ta (Latin, serrated border), 522.
Orbital fossa, 180
Orb’ito-sphe’noid bone, 181.

INDEX.

Organon’ymy (épydvov, an organ, and dvoua,
a name), designation of organs, 14.

ORGANS, determining volume and capacity ©

of, 185-136.
of hearing, 526.
of sense, 511-538.

Organum (Latin and Greek, an organ or
instrument) audi’tus, ear, and diagram
of parts, 526.

Orific’ium auric’/ulo-ventricula’re, 329.

ORIGIN and insertion of muscles, 195.
more important for determination of

muscular homologies, 196.
of the muscles of the eye, 519.
of the slip system, 52.

OS alisphenoi’deum, 181.
basioccipita’le, 181.
basisphenoi’deum, 181.
cotyloi’deum, 168.
ethmoturbina’le, 187.
fron’tis, 181.
innomina’tum, 168.
interparieta’le, 181.
juga’le, 181.
lachryma’le, 181.
lenticula’re, 529.
mala’re, 181.
maxilla’re, 181.
mesethmoi/deum, 187,
nasa’le, 181.
orbito-sphenoi’deum, 181.
palati‘num, 181.
parieta’le, 181.
periot/icum, 181.
pla‘num, 181.
premaxilla/re, 182.
pu’bis, 168.
supraoccipita’le, 181.
tempora’le, 181.
vo'meris, 187.
zygomat/icum, 181.

Ossic’ula audi’tus, bones of the ear, 528.

Osteol’ogy, 149-191.

Ova’rium, ovary, 296.

Pacinian Corpuscles, 281.
PACKING alcoholic specimens, 129.
instruments for transportation, 75.
Pagenstecher, 37.
Pail, waste, 81.
PAIRED and azygous, meaning of, 33.
or lateral organs, 43.
organs, 33.
PAL’ATE bone, 181.
soft, 304, 307, 512.
Pal’pebra (Latin, an eyelid) dorsalis, 514,
526.
Pan’creas and figures of, 278, 287, 288.
PANCREAT'IC DUCTS, 288, 290.
in man, and figure, 292.
lesser, 290.
principal, 290.
reservoir, 289-290.

*

——s

INDEX. 569

Papil'‘le, fun’giform and circumval’late,
305, 518

Paramas'toid (xapd, by the side of, and
pacroetdnc, resembling a nipple), 185.

PARCHMENT for labels, 68.
numbers, 68.

Pari’etal bone, 181.

Paroccipita’lis (apd, by the side of, and
Latin, occiput, the back of the head),
proces’sus, 185.

Paroccip’ital process, 185.

Parot’id gland, 801.

Pars cilia’ris ret'ine, 522.

Parting hair for i ey ances 148.

PARTS i in series,
of a muscle, 195.

Patel’la, 40.

PATTERN of the cerebral fissures, constant

characters, 501.
of the fissures, variable characters, 502.

PECTORAL muscles, figure of, 234.
ridge of the humerus, 159.

Peec'toralis group of muscles, general con-
siderations, 235.

Pedicle of a vertebra, 173.
PEDUN'CULUS (Latin, a small foot) me-
dius, medipedunculus, 481.

cerebel’li inferior, postpedunculus, 484,
cerebel'li superior, preepedunculus, 485.
cer’ ebri, crus cerebri, 476.
cona’rii, habena, 479.

Pel’vic bone, determination of right and
left, 150.

Pel'vis and figure of, 167, 168.

Pericar’ dium, 317, 321, 339, 362.

Perimys'ium (epi, around, ic, a muscle),
272.

Perineuw’rium (epi, around, veipor, a nerve),
398

Perios’ teum, attachment of muscles to, 195.
Periot’ic (tpi, around, and ovc, the ear), 181.
Periph’eral, use and significance, 26.
Peritone’al sac, 279.
PERITONE’ UM, 277, 279.

and viscera, diagram showing relations

of, 279.

structure of, 280.
Permanganate of potash, 83.
es a rawhide boot) olfactorius,

Pes olfacto’rius, 483.
Petit, canal of, in eye, 526.
Phalan’ ges, 41.
Phar’ynx, 307, Fig. 88.
Philistinism, anatomical, forms of, 204.
Philosophical Society, American, vi, 461.
PHYSIOLOGICAL and topographical po-
sition, 285.
sense, use of words in, 44.
PI'A MA’TER (Latin, pius, tender, mater,
mother), 483.
interior, 478.
removal from brain, 429.

Pigeon hole case and figure of, 51.

Pi'li tac’tiles, 512.

Pineal body, conarium, 476.

Pisifor'me, 41.

Pithing a frog, figure of, 536.

Pituitary body (hypophysis), 480.

Planes of the body, and figure of, 33, 34.

Plaster casts of medicornua, porta, etc., 458.

Plaster of Paris injection mass, 139, 140.

Plates of the brain, explanation, 461-471.

Plat/etrope (xAdroc, breadth, width, and
tpérecv, to turn), lateral homologue, fel-
low of the opposite side, 82.

Pleu’ra, 44, 309, 339.

PLEX’US CHOROI’DEUS infe’ rior, meta-

plexus, 482.
me’dius, diaplexus, 477.
ventric’uli latera’lis, proplexus, 485.
ventric’ uli ter’ tii, diaplexus, 473.
ventric’ uli quar’ti, metaplexus, 482.

PLEX’USES and tele, 370, 407.
not in proceelia of frog, 422.
of brain, 414.
of brain, injection of, 436.

Pli'ce cilia’ris, 522.

Pneumogas tric or vagus nerve, 509.

Poisoning dried preparations, 134.

Polishing instruments, 75.

PONS cerebel'li, 483.

Tarini, 484.

Jaro’ iii), 483.
POR’TA (Latin, a door), foramen of Monro,

421, 454, 483.

and au’la, 407, 454.

demonstration, 454.

existence demonstrated by plaster injec-
tion, figures, 458, 459.

PORTFOLIO for sheets, 51.
for slips, 48.

POR'TIO depres’sa (praeperfora’ ti), 483.
diencephal ica (cru’ris cer’ ebri), 483
mesencephal'i ica (cru’ris cer’ebri), 483
prom’inens (praeperfora’ti), 483.

Portiplex’us (Latin, porta, a door, and pleaus,
a plaiting or braiding), 483.

POSITION AND DIRECTION, designation

of, 20, 34, 35.
on the soma, BL.
Position in a physiological sense, 44.
POSTCA’VA, ve'na ca’va inferior, 329, 331,
356.
injection of, 147.

Postcommissu’ra (Latin, post, behind [cau-

dad of], and commissura, a connection),

j 484.
Postcor’nu (Latin, post, and cornu, a horn),
484,

POSTE’RIOR fissure of the spinal cord, 478.
white column of the spinal cord, 475.

Postgenicula'tum (Latin, post, and genicu-
lum,.a little knee),

Postna’ris (Latin, post, and naris, a nostril),
515.

570

Postop’ticus (Latin, , and Greek éxrixos,
relating to ghd, 484

Postpedun’culus (Latin, post, and peduncu-
lus, a little foot), 484.

Postperfora’tus (Latin, post, and perforare,
to bore through), 484.

Postzygapoph’ ysis (Latin, post, behind, vyor,
a yoke or junction, dz0, from, and guevv,
to grow, 173.

Potassium permanganas, 83.

Pouparti, ligamentum, 143.

Practical suggestions for dissectors, 201-203.

Preeca'va, for v. cava, superior, 329, 331,

449.

PRZCOMMISSU’RA (Latin, pre, before
[cephalad of], and commissura, a
connection), 484.

demonstration, 457.

Precor’nu (Latin, pre, and cornu, a horn),

Pregenicula’'tum (Latin, pre, and genicu-
lum, a little knee), 484.

Prena’ris (Latin, pre, and naris, a nostril),
513.

Prepedun’'culus (Latin, pre, and peduncu-
lus, a little foot), 485.

Preperfora'tus (Latin, pre, and perforare, to
bore through), 485.

Prezygpoph’ysis (Latin, pre, and Giyér, a
yoke or junction, do, from, and gveuv,
to grow), 173.

PRECAUTIONS against dissection wounds,
85

against fire, 114.
for cleanliness, comfort, and health, 81.
PREPARATION of bones, 103-111.
of ducts of salivary glands, 298.
of hollow viscera, 132.
of natural skeletons, 108.
of skulls, 107.
provisional, of specimens, 121.
PRESERVATION of amphibian brains, 418.
of brain, 429.
of heart in alcohol, 321.
PRIMARY divisions of the body, 29.
divisions of spinal nerves, 372.
PROCES’SUS clava’tus, clava, 475.
e cerebel’lo ad medul’'lam oblonga’tam,
postpedun’culus, 484.
e cerebel'lo ad pon’tem, medipedun’cu-
lus, 481.
e rgd ad tes'tim, prepedun’culus,

3.
odontoi'deus, 172.
aroccipita’lis, 185.
PROC’ LIA (po, before [cephalad of], and
kotzia, a hollow), 421, 485.

and rhinoce’lia, demonstration of, 454.
Proof spirit, 115.
Proplex’us (zp6, before, and Latin, plexus, a

twining or plaiting), 454, 485. ~
pi ed (xp6, before, and zovc, a foot),

INDEX.

PROSENCEPH’ ALON (zpé, before [cepha-
lad of], év, within, and xegad7, the
head), cerebrum, 475, 485.
of frog, 420.
Protuberan tia basila’ris, pons, 483.
Provisional preparations, 121. .
Prox’imal, use and significance, 25.
Psalte’/rium (Latin, a harp), lyra, 481.
Pseudo-cee’lia (wevdyjc, false, and xozia, a
hollow), fifth ventricle, 485.
Pseudo-commissu’ra of olfactory lobes in
frog and other Anoura, 420.
PU’BIC bone, 168.
symphysis, 169.
Pul’mo, lung, 310.
Pul’monary artery, 326.
PUPIL and iris, 520.
form in the cat, 520.
Putnam, J. Pickering, 5.
Pylo’rus, 282.
PYR’ AMIS, anterior pyramid, 485,
posterior, clava, 475.

Quad’rans (Latin, a four:h part), 486.
Quadrigem/inum (Latin, four or four fold),
op’'tici and postop’tici, 439.

Ra’dius, 40.
determination of right and left, 150.
RA’DIX (Latin, a root), exter’na, external
root of the olfactory tract, 486.
interme’ dia (cruris olfactorii), 486.
inter’na, inner or internal root of the
olfactory tract, 486.
Jatera’lis (cruris olfactorii), 485.
mesa’lis (cruris olfactorii), 486.
moto’ria (nervi trigemini), 486.
senso’ria (nervi trigemini), 486.
Ra’mi intesti’ni ten’uis, 359.
Ra’ rane (Latin, a branch), mandibularis,
188.
Razor strop, 78.
Readers’ and Writers’ Economy Co., 46.
REASONS for selecting the cat, 55.
for giving prominence to the viscera,
58

for treating only part of the body, 57.
Receptac’ulum chy’li, 364.
RECES’SUS au'li, 486.
opticus, 486.
preponti'lis, 586.
Rec’tum, 285.
Rec’tus muscles of the eye, 517-519.
Recurrent laryngeal nerves, figure of, 394.
Reduction of alcohol with water, 116.
REFERENCES, use of slips for, 47.
to books and authors, how made, 2-3.
to other publications, reasons for, 2.
Re’flex nervous centre, 371.
Re'gio au'lica, 486.
Regions of the vertebral column, 170.
Reissner’s membrane, 533.
Relation of cavities of the brain, 413.

INDEX.

Relative positions in an animal, and names
for, 17, 35.
REMOVAL of brain, 423.
of dura (mater), 428.
of heart, 319.
of pia (mater) from brain, 429.
of skin for muscles, 205.
of the tail, 102.°
REN, kidney, 278, 294.
section, 293.
Restifor’me (corpus), 486.
Restibra/chium, postpedun’culus, 484.
Re’te muco’sum, 512.
RET’INA, 522.
its ora serrata and pars ciliaris retine,
522.
RHINOC(’LIA (fic, the nose, xot2ia, a hol-
low), 454; 487.
and proceelia, demonstration of, 454.
examination of, 454.
RHINENCEPH’ALON (fic, the nose, é,
within, xeoaA7, the head), 450, 487.
examination of, 450.
of Amphibia, 470.
RIB, costa, 167.
head, neck, etc., 166.
figure of a pair of, 166.
joints of, 165.
Right and left, determination of, 149, 151.
Right heart, 328.
Rigor mor'tis, removal of, 205.
Ri’ma, great transverse fissure, 487.
Ri’pa, 488.
Ros'trum, 488,
Rouge for polishing, 76.
Royal Society’s Catalogue, 3.
RUBBER gloves, 68.
tubing, 68.
Rudd, W. N., 72.

Sa’crum, 169.

Sag’ittal suture, 183.

SAL'IVARY GLANDS, 297, 298.
and ducts, exposure of, 299.
figure of, 300.

Sarcolem/ma, 272.

Saw, care and figure of, 68, 74.

SCA/LA tym’pani, 530, 538.
vestib’ uli. 580, 583.

Scales, weighing, 68.

SCAL’PELS - cutting instruments, care

of, 74.
figures of, 66, 69.
figures of ways to hold, 199, 200.
how to hold, 199.

Scaphoi’des, 41.

SCAP’ULA, description of, 152.
determination of right and left, 150.
figures of, 154, 155.

Schneiderian membrane of nose, 5138.

SCISSORS, and figures of, 63, 70. -
care of and sharpening, 74, 79.
how to use, 200.

571

Sclerot/ica (oxAnpéc, hard), 521.
Seba’ceous glands, 512.
Seeker, tracer, 72.
Segmen’tal arrangement of encephalic
names, 409, 446.
SEG’/MENTS of brain, 404.
of limbs, 40.
Semicir’cular canals, 580.
BP ace e AR valves and figure of, 331,
valves, situation, 388.
Sense organs, 511-533.
Sensibil’ity, general, 511.
SEN’SORY and motor nerves and roots,
870, 372, 505, 506.
nerves, two great divisions, 506.
Separation of heart from lungs, 320.
Sep’ta of heart, 329.
Sep’tal area of brain, 473.
SEP’TUM auricula’re, 329.
lu’cidum cer’ebri, 488.
mediastina’le, 309, 339.
thorac’is, 309.
tympan’icum, 528.
ventricula’re, 329.
Series, enumeration of parts in, 42.
Sero’sa of heart, 341.
Sharpening instruments, 76.
Sharpness, determination of, 78.
Shepard and Dudley’s Catalogue, 59.
Sight, vision or visual sensibility, 511, 514,
Simple, ideal brain, figures of, 408.
Sinis'tral and dextral, use of, 24.
SINUS corona’ lis, 330.
fronta’lis, 183.‘
of cardiac vein, 380.
of heart, 329.
of Valsalva, situation of, 380, 338.
sphenoida’lis, 187.
Skeleton seen from left, figure of, 88.
Skel’etons, natural, preparation of, 108.
SKIN, cutis, appendages of, 512.
coloring matter, 512.
cutting the, 204.
removal for muscles, 205.
structure of, 512.
skinning, three methods of, 205.
SKULL, 173.
articulations of bones, 176.
base, figure of, 182.
cleaning of, 107.
disarticulating, 109.
do:sal aspect, figure of, 180.
figure of hemisected, 186.
Table of bones, 174.
Table of its foramina, 190.
SLIP box, 50. °
portfolios, 48.
system of notes, 45-52.
SLIPS, accumulation and elimination of,
AT

use of, ‘61.
Small intestine, 278, 283.

572 INDEX.

Smell, olfactory sensibility, olfaction, 511,
518.

Snowden, Catalogue of, 59.

Soft palate, 513.

SO’/MA (cdua, the body), and its divisions,
36

axial part of body, 15, 29.
Sdmmering, 505.
Specific gravity hydrometer, 114.
SPEC'IMENS, dishes and boxes for, 126-
127.
display of, 129.
for injection, 141.
jars, figures of, 127.
storage and exhibition of, 125-126.
transportation of, 129.
Spec’ulum, sep’tum luci’dum, 488.
Spencer, 194.
Spermat'ic cord, 143, 297.
Sphenoid’al si’nus, 187.
Spigelian lobe of the liver, 286.
Spi’na neura’lis, 173.
SPINAL cord, myelon, 372, 482.
nerves, 373.
Spi’ral lam’ina of cochlea, 529.
Spleen, splen, 278.
Sple’nium, 488.
Sponges, 70.
Sta’pes, stirrup, bone of the ear, 529.
Stenon’s duct, and preparation of, 298, 301.
Sternum, figure of, 163.
STOM’ ACH, preparation and drying, 132.
and duodenum, figure of, 281.
Stom/achus, stomach, 277, 282.
Stom/ata of lymphatics, 316.
STORAGE and exhibition of alcoholic spe-
imens, 125.
of notes, 48.
temporary, of specimens, 125.
STRI'A longitudina’lis, 488.
Lancisi, 488.
STRIA’TUM (Latin, striare, to mark with
grooves or channels), 488.
exposure, etc., 456.
supposed representative in frog, 421.
Stropping instruments, 78.
Structural relations of certain fissures, 497.
STRUCTURE OF the heart and vessels,
362-363.
large intestine, 285.
liver, 287.
mouth, 304.
lung, 311.
muscle, 272.
nervous matter, 398-399.
cesophagus, 308.
ovary, 296. :
Pacinian corpuscles, 281.
pancreas, 295.
peritoneum, 280.
salivary glands, 303.
small intestine, 284.
stomach, 283.

STRUCTURE of the tongue, 304.
trachea, 308.
urocyst, 295.
uterus, 296.

Stubs’s nippers, 68.

Subdivisions, muscular, 195.

Sublin’gual gland, 302. —

Submax’illary gland, 302.

SUL’'CUS (Latin, a furrow) habe’ne, 489.
intercrura lis latera’lis, 489.
intercrura’lis mesa’lis, 489.
lim’itans, 456, 489.
triradia’tus, 489.

Sulphate of iron as a deodorizer, 83.

Superior articulating progess, 173.

Supracon'dyloid foramen, 160.

Supraoccip/ital (Latin, supra, above, and
occiput, the back of. the head) bone,
181.

Suprare’nal capsule, 295.

Sur’cingle (cauda striati of brain), 474.

Surgeon’s knot, 144, Fig. 41. 7

SUSPEN’SORY LIGAMENT of the lens,

523.
of the urinary bladder, 294.

SUTU’RA corona’lis, 183.
lambdoida’lis, 183.
sagitta’lis, 183.

Sut’ures of the skull, 174, 176.

Sweat glands, 512.

Swift Manufacturing Co., 75.

Syl’vian fissure, its constancy, etc., 498, 501.

Symmetry, 48.

Sympathet'icus, sympath’icus, 369, 392.

SYMPATH'IC and vagus nerves, figure of,

366, 392.
neryous system, 369, 394.
SYMPATH'ICUS (civ, with, zador, suffer-
ing), sympathet'icus, 369, 394.
in sections of thorax, 341.

SYM’PHYSIS men’ti, 189.
pubis, 169.

Synonymy of muscles, Table of, 207.

SYR’INGES, use and care of, 1387.
figures of, 138, 139.

Syrin’gotome, figure of, 66, 71.

TABLE illustrating the subdivision of

notes, 49.

of bones of skull, 174.

of cranial nerves, origin, exit, distribu-
tion and function, 510.

of fissures, with synonyms, 496.

of foramina of the skull, 190.

of metric measures, 5.

of names and synonyms of encephalic
segments, 405.

of parts of Amphibian brain, 409.

of parts of heart, 322.

of physiological arrangement of the
cranial nerves, 506.

of principal divisions of body, 39.

of synonymy of muscles, 207.

of synonyms of cranial nerves, 505.

INDEX.

TABLE of systemic arteries of the trunk and
arm, 343, 344.
of thorac’ic veins, 342.
showing three methods of enumerating
the arched gyri, 501.
TACTILE hairs, 512.
sensibility of tongue, 513.
sensibility, taction, touch, 511, 512.
Tac’'tion, touch, tactile sensibility, 512.
Tx/nia hippocam’pi, fim’ bria, 478.
Tags for labels, 71.
TAIL, relation to body, 25.
removal of, 102.
Tailing to be avoided in dissection, 203.
Tape'tum (ramyc, a carpet), 522, 526.
TAR’SUS and car’ pus, 41. :
comparison with man, 41.
Taste, gustation, gustatory sensibility, 511,
512.

Tear glands, 515.
TECHNICAL TERMS compared with ver-
nacular, 16, 17.
désirability of retaining, 15.
necessity for, 16.
of myology, 194-197.
Teeth, fastening in the skull, 107.
TELA (Latin, a web), 414.
and plexuses, 407.
choroi'dea infe’rior, metate’la, 482.
of brain, 414.
Teleol'ogy, 56.
TEM’PORAL bone and fossa, 180, 181.
crest, 179.
Tem’ poro-auric’ular division of the trigem’i-
nus nerve, 301.
Tem’poro - fa’cial division of the facialis
nerve, 301.
Tenac’ulum, 71.
TEN’DON, 195, 272.
of the diaphragm, 311.
Tensor tympani muscle, 528, 533.
TENTO’RIUM (Latin, something stretched
out, a tent), 307.
bony, of cat, 187.
bony, removal, 428.
Ter’ma (répua, a limit, a terminus), lamina
terminalis, 422, 489.
Terminolog’ical changes, limits of, 18, 130.
TERMINOL’OGY, general considerations,
11.
or nomenclature, 10.
TERMS applying to whole body, 26.
of position and direction, 20.
technical, of myology, 194-197.
Tes’ tis, 297.
Tes'tis cer’ebri, postopticus, 484.
Testu’ do (Latin, a tortoise shell), 479.
Thalamenceph’alon (4é/ayoc, a bed, év, with-
in, kedad7j, the head), diencephalon, 477.
THAL’AMUS ner'’vi op'tici, 490.
op’ticus, 489, 490.
Thermometers, comparison and reduction of
scales, 3-4.

d73

THIRD eyelid, and action of, 515.
ventricle, and aula, 472.
THORACIC duets, 363.
ducts, figure of the left, 366.
nerves, 372.
or oar vertebre, and determination,

transection, 102.
THO’RAX, 37, 308.
figures of a frozen transection, 841.
figure of ideal transection, 43.
frozen sections, 338-342.
transection showing relation of sym-
pathic and spinal nerves, figure of,
897.
Thread and twine, linen, 61.
Thy’mus body, 309.
THY’ROID axis, 358.
body, 224.
or middle cervical ganglion, 395.
Tib’ia, determination of right and left, 151.
TONGUE, lingua, 512.
nervous supply, 5138.
papille of, 306, 307, 513.
tactile sensibility, 513.
uses of in speech, etc., 513.
Tools, carpenters’, 71.
Topon’ymy (roz0¢, a place, dvoya, a name),
designation of position and direction,
20, 23.
Torsion of humerus, not apparent in cat,
158.
Touch, taction, tactile sensibility, 512.
Towels, 71.
Lea ula (Latin, a small beam), of heart,
0.
TRACER, seeker, finder, 66, 71, 79.
how to use, 201.
Tra’chea, windpipe, 307.
TRAC'TUS op'ticus, 490.
postrhina lis, 490.
rhina’lis, 490.
transver’sus_pedun/culi, cimbia, 475.
Tralles, aleoémeter of, 114.
Transect, definition of term, 197.
TRANSEC’TION (Latin, trans, across, and
secare, to cut), 98.
abdominal, how to make, 98-101.
ideal of body, 80.
ideal of thorax, figure of, 43.
thoracic, 102,
Transverse process of a vertebra, 172.
Trape’zium, 490.
Trape’zius group of muscles, 208.
Trays, and care of, 72, 74.
Treatment of dissection wounds, 86.
Treman, King & Co., 68.
Tricus’ pid valves, 329, 331.
TRIFA’CIAL or trigeminal nerve, 507.
nerve. its sensory and motor roots. 507,

Trigem’ inus or trifacial nerve, its two roots,
507, 508.

574

Tripod magnifier, 72. -
TROCH'IN (rtpoyéc, anything spherical or
circular), 158, 160.
the caudal, lesser or inner humeral tu-
beros'ity, 160.
TROCH'ITER (rpoyxoc, a wheel, or anything
spherical or circular), 158, 160.
the cephalic, greater or outer, humeral
tuberosity. 160.
Troch’lea, 160.
Trochlea’ris or patheticus nerve, 507.
Troph’ic (tp0d%c, a feeder), centers, 371.
True skin, cutis vera, corium, derma, struc-
ture and function, 512.
Trunk and its divisions, 36.
Tuba Fallopiana, 296.
TU’BER annula’re, pons, 483.
' eine’reum, 423, 491.
TUBER’CULUM (coste), 167.
Loweri, 830.
Tuberos'ity of the ischium, 169.
TU'NICA oc'uli, 521.
vasculo’'sa, 523.
Tunnels, 72.
Tur’ binated bones, scrolls of, 187, 513.
Turner, H. W., 227.
Turpentine, spirits of, 110, 114.
Tying vessels, 144, 146.
TYMPAN’IC bulla, 185.
membrane, 527.
Tym’ panum, middle ear, 527, 528.

UL’NA, 40.
determination of right and left, 150.
Unciform eminence, calcar, 473.
Uncifor’me (Latin, wieus, a hook, and forma,
form), 41.
UPPER (dorsal) eyelid, 514.
jawbone, 181.
Ure'ter, 294.
U'rinary bladder, 278, 294.
U'rine, expelling, for cleanliness, 84.
Urocyst'is (odpov, urine, and xvoric, a cyst,
a bladder), 278, 294.
Use of dissecting instruments, 199.
U'terine ligaments, 296.
U'TERUS, 278, 295.
horns or cornua of, 296.

VA'GUS (Latin, vagus, wandering), 388,
392, 509.
and pppeibic nerves, figure of, 366,

in sections of thorax, 342.
or pneumogastric nerve, origin, etc.,

509.

VAL'VA bicus'’pis, 330.
il’eo-czeca’lis, 284,
semiluna’ris, 381.
Thebesii, 331,
tricus’ pis, 331.

VALVES of veins, 347.
in veins, figure of, 347.

INDEX.

=
Val'vula (Zatin, diminutive of valva, a
valve), valve of Vieussens, 491.
Variations of muscles, 193.
Vas def’erens, 297.
Va'sa chylif’era, 364.
Vas'cular system, general considerations,315.
VEINS, character and distinction from ar-
teries, 315. :
of the abdomen, Table, 348.
of the thorax, 349.
of the thorax and neck, Table, 342.
structure of, 363.
to be injected, 142.
Ve'lum pala'ti, figure, 307. -
VE’NA adre’no-lumba'lis, 356.
az'ygos, 331, 349.
bra’ chio-cephal'ica, s. innomina’ta, 349.
cardi’aca, 331.
ca'va, 331.
ca'va infe’rior, postcava, 356.
corona’ria ventric’uli, 356.
femora’lis, injection of, 146.
gas'tro-epiplo’ica, 356.
gas'tro-splen’ica, 355.
hepat'ice, 356.
ili‘aca communis, 357.
ili’aca exter’na, 357.
ili’aca inter’na, 358.
il’iolumba’lis, 357.
jugula’ris exter’na, 350.
jugula’ris exter’na, injection of, 147.
jugula’ris inter’na, 350.
mesenter ica infe’rior, 355.
mesenter’ica supe’rior, 355.
ova’ rii, 357.
pancreat’/ico-duodena lis, 356.
phren’‘ica, 356.
por’te, 355-356.
pulmona’ rie, 331.
rena’lis, 356.
spermat’ica, 357.
sterna’lis, 349.
subcla’via, 349.
subscapularis, 350.
vertebra'lis, 349.
VEN’TRAL and dorsal, use of, 24.
primary division of nerves, demonstra-
tion, 376.
VEN’TRICLES of brain, ccelize, 406, 440.
of heart, relative thickness, 332.
of heart, transection, figures, 336.
VENTRIC’ULUS (Latin, the belly, a cav-
ity), communis, aula, 472-473.
dex’ter of heart, 352, 337.
latera’lis, procoelia, 485.
olfacto’rius, rhinoccelia, 487.
op’ticus, s. mesencephalici, 482.
quar’tus, metaccelia, 482.
quin’tus, pseudoceelia, 485.
sinis’ter of heart, 332, 338.
ter'tius, diaccelia, 477.
Vernacular terms compared with technical,
16, 17.

INDEX.

VER’TEBR&, 37.
cervicales, figure of, 172.
figure of, 173.
VER’ TEBRAL column, regions of, 170.
ganglion, 395.
notch, 173.
ring, 172.
Ver'tebrate, figure of various aspects, 30.
Vertebrarte’rial (Latin, vertebra, and arteria),
foramen, 171, 173.
Vesi’ca urina’ria, wrocystis, 294.
VESSELS, distinguishing from nerves, 375.
how to connect when severed, 511.
of thorax and arm isolated, 347.
Vestib’ulum (of the ear), 527, 538.
Vial for brain or heart, figure of, 128.
Vibris’s (Latin, vibrare, to move quickly to
and fro), 512.
Vil'li of intestine, 284.
VIS'CERA, abdominal,
and peritoneum, diagram showing rela-
tions, 279.
general view of, 276.
preparation of, 182.
Vis'ceral and neural cavities, 32.
Vision, sight or visual sensibility, 511, 514.
Visual sensibility, sight vision, 511, 514.
Vit'reous humor, 522.
Vit‘reum (Latin, of or like glass), 522,

526.
VOCABULARY, macroscopic of brain, 436.
partial, of amphibian brain, 403,
Volition, center of, 371.
Volume of organs, determining, 136.
Vo'mer, 187.

Ward, Henry A., 536.

5Y5

WASTE pail, 81.

of, 116,

Wax and tallow injection masses, 141.

Weighing pan, 69.

Weight of brain, determined from capacity
of skull, 191.

WETTING bottle, and mixture, 72, 738.
bottle for 15 per cent. glycerin, figure

of, 72.

Wharton’s duct, and preparation of, 298,
302,

Whetstone, coarse and fine, 76.

Whitall, Tatum & Co., Catalogue of, 59.

WHITE nervous matter, 472.
substance of Schwann, 369, 398.
zone of the eyeball, 521, 526.

Wickerscheimer’s liquid, preparation and
use, 124.

Wigglesworth, E., 8.

Wilkinson, A. J., Catalogue of, 59.

Willis, 505.

Windpipe, trachea, 307.

Womb, uterus, 295.

Wood spirit or methylic alcohol, 124.

Words, formation of compound and hybrid,

Wounds, dissection, 85.
Wyman on anatomical use of cat, 56,

Zinc chlorid for hardening brain, 435.
Zona alba of the eye, 521, 526.
Zo'nula Zinnii, 523.

Zoological classification, 8.

Zygomat/ic gland, 303.

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