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Journal 


OF    THE 


Royal 
Microscopical  Society; 

CONTAINING   ITS   TRANSACTIONS   AND    PROCEEDINGS 

AND  A  SUMMARY  OF  CURRENT  RESEARCHES  RELATING  TO 

zooXiOG-^sr    -A-3sriD    B o T .A. nsr ^2- 

(principally  Invertebrata  and  Cryptogamia), 


PRANK    CRISP,    LL.B.,     B.A., 

One  of  the  Secretaries  of  the  Society 
and  a  Vice-President  and  Treasurer  of  the  Liftttean  Society  of  London  ; 

WITH   THE   ASSISTANCE  OF    THE    PUBLICATION    COMMITTEE    AND 

A.  W.  BENNETT,  M.A.,  B.Sc,  I  F.  JEFFKEY  BELL,  M.A., 

Lecturer  on  Botany  at  St.  Thomas's  Hospital,       \  Professor  of  Comparative  Anatomy  in  King's  College, 

S.  O.  RIDLEY,  M.A.,  of  the  British  Museum,  and  JOHN  MAYALL,  JuN., 

FELLOWS   OF  THE  SOCIETY. 


.-VOL.  III.         TiHrtlL 


PUBLISHED   FOR   THE  SOCIETY   BY 

WILLIAMS    &    NORGATE, 

LONDON    AND    EDINBURGH. 
I  885^ 


\jol-  3 


)p  BI-MONTHLY.  SE^  \ 

Vol.  III.  No.  4.]  AUGUST,  1880.  [  "^  p^ce  487'' 


f 


Ai. 


Journal 


OF   THE 


Royal 
Microscopical  Society; 

CONTAINING   ITS  TRANSACTIONS  AND   PROCEEDINGS, 

AND  A  RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

INVERTEBRATA,   CRYPTOGAMIA, 
MICROSCOPY,  &c. 


Edited,  tinder  the  direction  of  the  PiMication  Committee,  by 

FRANK    CRISP,   LL.B.,   B.A.,   P.L.S., 

One  of  the  Secretaries  of  the  Society; 

WITH   TUB  ASSISTANCE  OP 

A.  W.  BENNETT,  M.A.,  B.Sc,  j  F.  JEFFREY  BELL,  M.A,. 

Lecturer  on  Botany  at  St.  T/umias's  Hospital,  |  Professor  of  Contparaiive  Anatomy  in  King's  College, 

AND 

S.  O.  RIDLEY,  B.A.,  F.L.S., 

Of  i/ie  British  Mtisctim, 


\ 


FELLOWS  OF  THE  SOCIETY,,.- 


WILLIAMS    &    NORGATE, 


M  LONDON   AND   EDINBURGH.  ^i^l 

PRINTED  BV   WM.  CLOWES  AND  SONS,  UMITkD,]  [STAMrORD  STKBET  ANf  CIIARJNO  CRO..S. 


(     2    ) 

JOUENAL 

OF  THE 

EOYAL  MICEOSCOPICAL  SOCIETY. 

VOL.  III.    No.  4. 


CONTENTS. 

Tbansactions  of  the  Society —  paob 

XVI.  Notes  on  Aoinetina  :  Trtchophrya  epistylidis,  and  Podo- 
PHRYA  QUADRiPARTiTA.  By  John  Badcock,  F.R.M.S.  (Plate 

XIV.)             561 

XVII.  On  the  Visibility  of  Minute  Objects  mounted  in  Phos- 
phorus, Solution  of  Sulphur,  Bisulphide  op  Carbon,  and 
other  Media.     By  J.  W.  Stephenson,  Treasurer  R.M.S., 

F.R.A.S ..  664 

XVIII.  On  the  Development  and  Retrogression  of  Blood-vessels. 
By  George  Hoggan,  M.B.,  and  Frances  Elizabeth  Hoggan, 

M.D.     (Plate  XV.) 568 

XIX.  On  a  Parabolized  Gas  Slide.     By  James  Edmunds,  M.D., 

M.R.C.P.  Lond.,  F.R.M.S.     (Figs.  52  and  53)       ..           ..  585 

Record     of     Current    Researches    relating    to    Invertebrata, 

Cryptogamia,  Microscopy,  &c.        ,.          ..          ..           ..  587 

Zoology. 

Bevelopmeut  of  the  Vertebrate  Eye 587 

Embryology  of  Batrachiuns       587 

Vital  Properties  of  Cells 589 

Coalescence  of  Amoeboid  Cells  into  Plasmodia        590 

Structure  and  Development  of  Dentine 590 

Ovary  of  Mammals 591 

Influence  of  Saline  Solutions  on  Protoplasm 591 

"  Law  of  Association'        592 

Degeneration         594 

Animal  Development 597 

Colours  of  Animals 598 

Organisms  in  Ice  from  Stagnant  Water  ..      598 

Fertilization  of  the  Ovum 599 

Renal  Organs  of  Invertebrata 600 

Phylogeny  of  the  Dibranchiate  Cephalopoda COl 

Aptychi  of  Ammonites         604 

Development  of  the  Pulmoimte  Gaderopoda 005 

Generative  Organs  of  (he  Young  Helix  aspersa      608 

Gasteropoda  from  the  Troas      608 

Gasteropoda  from  the  Auckland  Islands 608 

Marine  Polyzoa 609 

Fresh-water  Polyzoa 609 

Larva  of  Bowerhankia       611 

Enldi minaria  ducalis         611 


(  «  ) 

Beoord  op  Current  Kbskarohes,  &c. — continued. 

PAQB 

Nervous  Collars  of  Arthropods 611 

Nerve-endings  in  Muscles  of  Insects         .. 612 

Habits  of  Ants 613 

Bespiratory  and  Circulatory  Apparatus  of  Dipterous  Larvx       615 

Blepharoceridse 616 

Tracheal  System  of  Larval  Libellulidm 61(j 

Hemains  of  Branchias  in  a  Libellulid:  Smooth  Muscle-Fibres  in  Insects    ..  618 

Metamorphosis  of  Prosopistoma        618 

Piercing  Organ  of  the  Lepidopteran  Proboscis      619 

Generative  Glands  and  Sexual  Products  in  Bombyx  mori     620 

Development  of  Forficula 621 

Adora  sestuum  from  the  Shore  at  Heligoland 621 

Destruction  of  Noxious  Insects  by  Mould 622 

Development  of  the  Araneina 622 

Peculiar  Modification  of  a  Parasitic  Acarian       624 

Structure  of  Trombidium 625 

Central  Nervous  System  of  the  Crayfish 627 

Influence  of  Acids  and  Alkalies  on  Crayfishes        628 

Head  of  the  Lobster    .,      .. 629 

Shoiiened  Development  in  Palxmon  potiuna 630 

Toilet-appendages  of  the  Crustacea ..      ..      ,.  631 

Anal  Btspiration  of  the  Copepoda 632 

Parasitic  Corycxidse 633 

Parasite  of  the  American  Blue  Pike 633 

New  Crustacea 634 

Genital  Glands  and  Segmental  Organs  of  the  Polychseta      635 

Development  of  the  Spermatozoa  of  the  Earthworm        63G 

Embryology  of  Ligula        637 

Nervous  System  of  the  Trematoda 638 

New  Turbellarian       , ..      ..  640 

New  Nemerteans 640 

New  Genus  of  Echinoidea 641 

Fossil  Tertiary  Echini       641 

Mediterranean  Echinoderms      J     642 

Remarkable  Ophiurid         642 

Intracellular  Digestion  in  Ccelenterata 642 

Nervous  System  of  Beroe . .      . .  643 

Pleurobrachia  pileus 644 

Anatomy  and  Histology  of  tJie  Actiniae 645 

Structure  of  some  Coralliaria . .      . .  648 

Antipatharia  of  the  '  Blake '  Expedition 649 

American  Siphonophora .,      649 

Origin  and  Development  of  the  Ovum  in  Eucope  before  Fecundation  .,      .,  650 

Proportion  of  Water  in  the  Medusm 652 

A  Fresh-water  Hydroid  Medusa       652 

Physiology  of  the  Fresh-water  Medusa 657 

Sponges  of  the  Leyden  Museum 661 

Structure  and  Affinities  of  the  Genus  Protospong id,  Salter 661 

Batschli's  Protozoa     662 

Amaebiform  and  other  new  Foraminifera        .,     662 

Vumpyrella  lateritia  .,      ..      .. 664 

Acinetx        l°65 

Botany. 

Disengagement  of  Carbonic  /  'I  from  Boots 665 

Sensitiveness  in  the  Acacia        665 

Copper  in  Plants          666 

Action  of  Ozone  on  the  Colouring-matters  of  Plants       667 

Bed  Cohuring-matter  of  the  Leaves  of  tlie  Virginian  Creeper      667 

Chemical  Composition  of  Aleurone-grains        667 

*' Ci stoma" 668 

Apical  Growth  with  several  Apical  Cells 668 

Structure  of  the  Fructification  of  Pilularia *  . .      . .  6(59 

British  Moss-Flora 670 


(  4  ) 

Kkoobd  op  Current  Eeskabohbs,  &c. — continued. 

PAGE 

British  Characese 670 

Formation  of  Fat  in  Fungi       671 

Secretion  from  a  Fungus 671 

Anthracnose  of  the  Vine      671 

Urocystis  Cepulx 672 

Sterigmatocystis  and  Nematogonum 672 

Mycotheca  Marchica 672 

Ceriomycesterrestris 673 

Vine-pock     , 673 

Prehistoric  Polyporus 673 

Relationship  of  Ozonium  to  Coprinus       , .      . .  673- 

Dieease  of  the  Apple-tree  caused  by  Alcoholic  Fermentation 674 

Saecharomyces  apiculutus 674 

Plasmodia  of  Myxomycetes        674 

Epiphora      675 

Lichens  of  Mont-Dare  and  Haute-Vienne        ..      ..      675 

Morphology  of  Floridex 676 

Bilateralness  in  Floridem 677 

Fructification  of  Chsetopteris  plumosa      678 

Fructification  of  Squamariem    . .      678 

Fresh-water  Algse  of  Nova  Zemhla 679 

Thermal  Anahmna      679 

Polycystis  xruginosa,  a  cause  of  the  Bed  Colour  of  Drinking-water    ..      ..  680 

Bain  of  Blood      680 

Endochrome  of  Diatomacese  (Fig.  54:)      680 

Belgian  Diatomacese , . .      . .  687 

New  Deposit  of  Diutomaceous  Earth        688 

Preservation  of  Solutions  of  Palmelline 688 

Microscopy. 

Localities  for  Fresh-water  Microscopical  Organisms     689 

Collection  of  Living  Foraminifera 690 

Cleaning  Foraminifera      692 

Wax  Cells 692 

Carbolic  Acid  for  Mounting      693 

Double-staining  of  Vegetable  Tissues . .      . .  693 

Wickersheimer's  Preservative  Fluid  and  Vegetable  Objects 696 

Hardening  Canada  Balsam  in  Microscopic  Preparations  by  Hot  Steam    . .  696 

Ringing  and  Finishing  Slides 696 

Cleaning  Cover-glasses       698 

Preparing  Sections  of  Coal       698 

Cutting  Bock  Sections         699 

Simple  Mechanical  Finger . .      .,      700 

Slides  from  the  Naples  Zoological  Station        700 

Homogeneous-Immersion  Lenses        701 

Fluid  for  Homogeneous  Immersion ..      ..  701 

Errors  of  Refraction  in  the  Eyes  of  Mieroscopists 701 

Micrometre  or  Micromillimetre . .  702 

Micrometry  and  Collar-adjustment    ..      . . 702 

Zeiss' s  Microspectroscope  (Fig.  55) 703 

Boss's  Improved  Microscope  (Pl&te  X.YI.)      704 

Professor  Huxley's  Dissecting  Microscope  (Fig.  56)      705 

Nachet's  Chemical  Microscope  (Fig.  57) 707 

Tiffany's  Prepuce  Microscope 709 

Tolles-Blackham  Microscope-stand    ..      ..      ,,      ..      , 709 

Weber-LieVs  Ear  Microscope  (Fig.  58) 710 

Trichina-Microscopes — Hager's,  Schmidt  and  Haensclis,  Waechter's,  and 

Tescftwer's  (Figs.  59-63)        ..      ..      711 

Matthews' Improved  Turntable  (Figa.  64:  and  65) 716 

BiBIJOGRAPHY         .4             ..             ..              ..             ..             ..              ..              ..  718 

Peoobbdings  of  the  Society  ..          ..          ..          ..          ..          ..  733 


JO  URN.  R.MICR.  SOC.VOL.III.pl. XIV, 


(I 


H.^Mmx7ar  Co  lith 


AemetmaJriehopLrya   episLylidis  ^Podophrya  quadripar^ita 


JOURNAL 

OF    THE 

ROYAL  MICROSCOPICAL   SOCIETY. 

AUGUST,  1880. 


TRANSACTIONS  OF  THE   SOCIETY. 


XVI. — Notes  on  Acineiina:  Trichojylirya  episfyliclis,  and  Podo- 
jplirya  qiuidripartita.    By  John  Badcock,  F.R.M.S. 

(Bead  10th  March,  1880.) 
Plate  XIV. 

Eakly  in  November  1879  I  found  on  some  filamentous  Algae  in 
one  of  the  ponds  in  Victoria  Park,  a  curious  amoeboid  form  of  what 
seemed  to  be  an  Acineton,  and  which  I  subsequently  found  had 
been  originally  discovered  by  MM.  Claparede  and  Lachmann, 
and  named  Trichophrtja  epistylidis.  They  found  it  parasitic  on 
the  Epistylis,  and  being  struck  with  its  singular  character,  con- 
sidered it  entitled  to  rank  as  a  new  genus  under  the  above  name. 
They  give  a  somewhat  brief  account  of  it.  It  is,  however,  very 
singular  that  those  authors  should  have  contrasted  this  form  with 
Podophrya  quadripartita  (originally  discovered  by  Baker,  and 
subsequently  found  by  Stein).  Stein  had  argued  in  favour  of 
the  theory  of  the  ^cme^a*-state  in  the  life-history  of  many  of  the 
Infusoria,  and  among  others  had  described  P.  quadripartita  as 
the  Acineta  of  Epnstylis  plieatilis,  because  they  were  generally 
found  together,  and  Claparede  and  Lachmann  say  that  for  the 
same  reason  T.  epistylidis  might  be  inferred  to  be  similarly  related 
to  the  Epistylis,  for  "  The  one,  hke  the  other,  seems  in  eflfect  to 
lead  the  life  of  a  parasite,  almost  exclusively  on  the  branches  of 
EpistyUs." 

It  would  be  a  curious  commentary  on  the  disputes  of  those 
high  authorities  on  these  matters  if  it  could  be  shown  that  Ti'i- 
chophrya  epistylidis  and  Podo'phrya  quadripartiia  are  one  and 
the  same  species  in  different  stages,  and  that  EpistyUs  has  nothing 
to  do  with  either.  Such  I  believe  to  bo  the  case,  as  the  following 
observations  will  show,  if  not  conclusively,  yet  as  probable  in  the 
highest  degree. 

I  do  not  think  that  the  identity  of  the  organism  which  I  found 

*  This  theory  has  since  been  abandoQcd  by  Stein. 
VOL.  III.  2  r 


562  Transactions  of  the  Society. 

(PI.  XIV.,  Fig.  1)  with  those  of  Claparede  and  Lachmann  will  be 
disputed,  as  both  the  figures  and  descriptions  prove  it,  with  one  or 
two  exceptions  which  are  not  essential.  Thus,  as  to  parasitism, 
I  did  not  find  mine  on  the  Ejpistylis,  but  on  filamentous  algae : 
neither  have  I  seen  the  faint  outline  of  any  embryo  as  described  by 
them. 

Having  placed  my  first  find  in  a  small  zoophyte  trough,  for 
the  purpose  of  daily  watching  it,  I  soon  noticed  that  the  sides  of 
the  glass  were  covered  with  very  much  smaller  bodies  than  those 
on  the  algse,  and,  though  having  the  same  Acineta-like  character, 
were  much  more  varied  in  form  as  well  as  being  very  transparent 
(see  Figs.  2,  2a,  and  3).  These  were  very  interesting  objects  of 
observation,  as  one  could  plainly  see  the  contractile  vesicles,  the 
suctorial  character  of  the  tentacles,  and  their  slowly  spiral  move- 
ment of  protrusion  and  retraction.  They  were  not  of  slow  growth, 
but  came  suddenly  as  though  a  vesicle  or  similar  body  had  been 
ruptured  and  its  contents  shot  forth,  which  coming  in  contact 
with  the  glass  would  produce  just  the  appearance  noted.  The 
contractile  vesicles  were  similarly  irregular,  both  as  to  position  and 
number.  In  fact,  it  was  impossible  to  find  any  two  bodies  alike 
in  shape  or  organic  differentiation.  Only  one  common  character 
pervaded  them,  they  were  all  bright,  shining  patches,  semi-fluid, 
transparent,  and  acinetiform. 

As  the  winter  advanced  the  pseudopodia  or  tentacles  disap- 
peared, and  also  the  contractile  vesicles  and  other  signs  of  active 
life,  leaving  only  small  lumps  and  patches  of  what  may  be  called 
protoplasm.  These  had  nothing  of  the  appearance  which  death 
produces.  They  were  simply  bits  of  quiescent  matter,  looking 
more  like  shining  crystals  than  anything  else. 

I  had  not  expected  to  be  able  to  make  any  further  observations 
until  another  season,  when  the  following  incident  attracted  my 
attention.  I  had  given  some  of  the  algae  to  my  friend  Mr.  Cocks, 
with  the  animal  forms  on  it  in  abundance,  which  he  placed  in  his 
aquarium.  This  he  has  recently  found  to  be  covered  with  the 
very  beautiful  forms  represented  in  Figs.  4  and  5,  or  in  other 
words  by  Podophrya  quadrijKcrtita.  On  seeing  these  at  first,  and 
taking  note  of  similarity  in  some  points  notwithstanding  difierences 
in  others,  my  suspicions  as  to  tlieir  being  the  same  were  mate- 
rially strengthened,  if  not  confirmed,  by  comparison  with  one  form 
which  I  had  drawn  last  November  (Fig.  6).  This  was  found  with 
the  others,  but  not  presenting  the  same  special  appearance,  I  had 
not  considered  it  in  its  true  character ;  and  my  view  now  is,  that  as 
in  all  forms  of  life  some  few  more  vigorous,  or  favoured  by  other 
circumstances,  will  remain  after  the  majority  have  passed  away,  so 
these  solitary  individuals  remained.  There  can  be  no  doubt,  I  think, 
of  the  identity  with  Figs.  4  and  5. 


Notes  on  Acinetina.     By  John  Badcock.  563 

This  being  so,  Nos.  1,  la,  2,  and  3,  are  the  immature  stages  in 
the  life-history  of  the  perfect  form  now  recognized  as  Podoplirya 
quadripartita ;  and  consequently  the  new  genus  Tricliophrya  of 
Claparede  and  Lachmann  must  be  abandoned. 

One  of  the  forms  here  figured  illustrates  the  so-called  Acineta 
of  Epistylis.  Fig.  7  is  the  Ejnstylis  with  the  Acineta  here 
and  there  upon  its  branches,  and  on  first  observing  it  under  the 
Microscope  with  Mr.  Cocks  we  were  inclined  to  think  it  a  con- 
firmation of  Stein's  theory,  when  my  son,  whom  we  had  asked  to 
sketch  it,  remarked  that  it  was  not  a  portion  of  the  Epistylis,  but 
only  attached  to  it.  It  was  somewhat  difficult  to  see  the  attachment, 
however,  but  we  were  confirmed  as  to  its  nature  by  subsequently 
seeing  it  on  Carchesium  and  Ophrydiu7n,  as  well  as  by  its  abnormal 
position  on  the  sides  of  the  branches  of  Ejnstylis. 

Since  writing  the  foregoing  I  have  been  able  to  make  some 
further  observations  of  an  interesting  nature,  which  I  will  briefly 
state. 

I  have  traced  the  life-history  of  one  form  with  tolerable  clear- 
ness. I  had  often  noticed  several  small  round  ciliated  bodies 
moving  about  the  field  of  view,  sometimes  rapidly  spinning  round, 
and  then  springing  with  a  jerking  bound  from  place  to  place.  On 
pursuing  one  of  these  bodies  it  was  found  finally  to  settle  down 
on  a  filament  of  the  alga,  and  gradually  to  develop  a  peduncle; 
then  the  ciliate  character  simultaneously  changed  to  that  of  the 
Acineta,  and  finally  it  gradually  branched  out  to  the  three-  or 
four-cornered  perfect  form  of  Podojjhrya  qiiadripartita* 

These  ciliated  forms  correspond  to  the  description  usually 
given  to  Megatricha  imrtita,  and  in  their  further  development — 
attached  and  with  a  pedicle — to  Podophrya  fixa.  Further  I  have 
obseiTed  that  in  the  Megafrieha-stsLte  they  multiply  by  self- 
division.  May  we  hazard  the  inference,  in  view  of  these  observa- 
tions, that  as  not  only  these,  but  many  other  similar  forms  of  life, 
pass  through  several  life-cycles,  in  each  of  which  they  "  increase 
and  multiply,"  this  peculiarity  has  been  the  fruitful  cause  of  num- 
berless new  genera  and  species  having  been  too  hastily  adopted  ? 

*  This  I  have  seen  in  many  instances  since,  and  found  tlicni  to  develop  on 
the  glass  as  well  as  on  the  weed. 


L'  P  li 


564  Transactions  of  the  Society. 

XVII. — On  the  Visibilitij  of  Minute  Objects  mounted  in  Phos- 
phorus, Solution  of  Sulj>hur,  Bisulphide  of  Carhon,  and  other 
Media.    By  J.  W.  Stephenson,  Treasurer  E.M.S.,  F.K.A.S, 

CSead  9th  June,  1880.) 

The  theory  that  there  is  a  "  loss  of  aperture  on  balsam-mounted 
objects  "  was  enunciated  more  than  twenty  years  ago  by  more  than 
one  writer,  and  although  never  accepted  without  question,  it  has 
been  maintained  with  more  or  less  frequency  until  a  comparatively 
recent  date,  when  Professor  Abbe's  demonstration  of  the  theory  of 
microscopic  vision  rendered  it  absolutely  untenable. 

It  is  not  only  untrue  that  there  is  a  loss  of  aperture  under  such 
circumstances,  but  it  is  positively  the  reverse  of  the  truth  in  every 
case  in  which  it  produces  any  effect  whatever. 

It  has  already  been  pointed  out  in  the  Society's  Journal,* 
how  this  mistaken  notion  probably  arose,  viz.  by  failing  to  distin- 
guish between  a  diminution  of  angle  (which  of  course  takes  place 
in  the  case  of  balsam-mounted  objects)  and  a  diminution  of 
aperture,  two  entirely  different  matters,  as  a  small  angle  in  one 
medium  (as  oil)  may  be  capable  of  embracing  more  diffraction 
spectra  than  a  large  angle  in  another  medium  (as  air),  the  small 
angle  having  in  fact  the  larger  aperture  and  vice  versa. 

The  loss  of  aperture  by  transmitted  light  is  therefore  on  objects 
mounted  in  air,  and  this  can  only  be  prevented  by  mounting  in 
balsam,  or  some  other  medium  which  has  a  refractive  index  equal 
to,  or  greater  than,  the  numerical  aperture  of  the  immersion  objec- 
tive employed. 

This  loss  from  "  dry  mounting,"  as  it  is  called,  arises  in  all 
objectives  which  have  an  equivalent  angle  exceeding  180°,  which 
is  the  case  with  so  many  of  the  modern  immersion  objectives,  and 
notably  so  in  those  on  the  homogeneous  principle. 

It  is  this  fact  which  has  induced  me  to  bring  the  subject  of 
mounting  in  different  media  before  the  Society  this  evening,  as  it 
is  obviously  of  little  use  to  obtain  objectives  of  the  large  apertures 
with  which  we  are  now  familiar,  if  by  employing  them  on  objects 
surrounded  by  air  we  reduce  their  effectiveness  to  the  common 
level  of  180"  (=  1  n.  a.). 

I  have  said  "  surrounded  by  air  "  because  when  an  object  is  in 
physical  contact  with  the  cover,  the  loss  is,  by  its  adhesion  on  one 
side,  reduced  to  one-half,  just  as  in  an  object  mounted  in  balsam  the 
whole  aperture  is  preserved  by  the  contact  of  both  its  sides  with 
the  medium  in  which  it  is  mounted. 

But  in  mounting  diatoms  (and  some  other  objects)  in  Canada 
balsam,  we  find  that  although  we  have  secured  the  full  aperture  of 

*  See  this  Journal,  ii.  (1879)  p.  774. 


On  the  Visibility,  &g.     By  J.  W.  Stephenson.  565 

the  objective,  and  therefore  its  fall  resolving  power,  we  have  done 
so  at  the  expense  of  the  visibility  of  the  resultant  image,  which 
has  become  fainter  by  the  nearer  approximation  to  equality  of  the 
refractive  indices  of  the  diatomaceous  silex  and  the  Canada  balsam 
in  which  the  object  is  mounted ;  the  markings,  whatever  they  may 
be,  are  less  pronounced  than  they  would  have  been  in  air  had  the 
structure  been  sufficiently  coarse  for  resolution  in  that  medium,  a 
result  which  Professor  Abbe  has  shown  to  be  attributable  to  the 
paler  diffraction  spectra  yielded  by  the  balsam-mounted  object — 
hence  we  see  that  it  may  be  possible  to  resolve  an  object  in  balsam 
which  would  be  impossible  in  air,  but  that  if  resolvable  hi  hoih  it 
would  be  more  visible  in  air  than  in  balsam. 

It  may  be  demonstrated  that  the  visibiHty  of  very  minute 
structures  is  ijroportional  to  the  difference  between  the  refractive 
indices  of  the  object  and  the  medium  in  which  it  is  mounted 
{n-ni). 

It  follows  from  this  that  when  this  diiference  =  0,  or  is  very 
small,  the  structure  is  invisible.  This  is  the  case,  as  most  of  us 
know,  when  diatoms  are  immersed  in  strong  suljihuric  acid,  and  it 
may  therefore  be  inferred,  as  was  pointed  out  some  years  ago,  that 
the  refractive  index  of  diatomaceous  silex  is  about  1  •  43,  which, 
without  any  pretence  that  it  is  exact,  I  shall  assume  as  its  true 
value  in  the  following  observations. 

As  the  visibility  of  minute  structures  is  proportional  to  the 
difference  between  the  refractive  indices  of  object  and  medium,  it  is 
necessary  to  give  a  short  table  of  the  refractive  indices  of  those 
substances  to  which  I  shall  refer,  and  fi'om  which  the  differences  of 
the  indices  are  to  be  deduced. 

Table  of  Indices. 

Air =1 

Water       =   1-33 

Diatomaceous  silex  and  sulphuric  acid       =   1'43 

Canada  balsitni        =   1'54 

Bisiilpiiide  of  carbon      =   l'G8 

Solution  of  sulphur  in  bisulphide  of  carbon  (approximately)  . .  =   1-75 

Sulphur =  2-11 

Solution  of  phosphorus  in  bisulphide  of  carbon  (approximately)  =2  10 

The  first  case  we  will  consider  is  that  of  the  visibihty  of  a  diatom 
in  air,  which,  although  it  is  otherwise  excluded  from  consideration 
in  consequence  of  the  lo.-^s  of  aperture  involved,  is  nevertheless 
valuable  as  a  standard  of  comparison. 

The  index  of  diatomaceous  silex  being  taken  as  1  •  43,  and 
that  of  air  being  1,  we  have  as  a  measure  of  the  visibility  of  a  fine 
diatom  in  air  the  number  "43. 

Taking  now  the  various  media  in  succession,  and  connucncing 
with  water,  of  which  the  index  is  I  '33,  the  index  of  diatomucious 


566  Transactions  of  the  Society. 

silex  being,  as  before,  1  *  43,  the  difference,  being  tbe  measure  of 
visibility  of  a  diatom  in  ivater,  is  represented  by  'lO. 

The  next  in  order  is  Canada  balsam,  with  its  index  of  1 '  54 ; 
deducting  the  index  of  silex,  1  '43,  we  obtain  the  difference  of  •!!, 
which  is  the  measure  of  visibility  of  the  same  object  in  balsam,  and 
almost  identical  with  that  of  water. 

The  next  in  succession  is  bisulphide  of  carbon,*  index  1*68, 
diatomaceous  silex  1  •  43,  giving  as  the  measure  of  visibility  in 
hisuljihide  of  carbon  '  25,  which  it  will  be  observed  is  about  two 
and  a  half  times  as  great  as  that  obtainable  in  water  or  balsam. 

This  result  may  however  be  exceeded  by  dissolving  sulphur  in 
the  bisulphide  of  carbon,  although  to  what  extent  I  am  unable  at 
this  moment  to  say,  but  as  sulphur  has  an  index  of  2*  115,  and  is 
moderately  soluble,  I  think  I  am  safe  in  assuming  that  the  index 
of  the  solution  is  1  •  75 ;  deducting  from  this  1  ■  43,  we  obtain  •  32 
as  the  measure  of  visibility  in  solution  of  sul^jhur,  which  is  nearly 
three  times  as  great  as  that  of  balsam. 

The  last  in  the  list  is  phosphorus,  but  as  this,  from  its  crystal- 
line character,  cannot  be  conveniently  used  in  its  solid  form,  it  is 
also  dissolved  in  bisulphide  of  carbon,  the  solution  being  just  short 
of  that  point  at  which  crystals  appear. 

From  the  extreme  inflammability  of  phosphorus  and  other  diffi- 
culties it  is  very  improbable  that  it  will  ever  be  used  to  any  great 
extent,  although  there  is  to  my  mind  great  scientific  interest  in 
the  experiment. 

If  we  take  the  solution  of  phosphorus  as  having  an  index  of 
2*1,  and  deduct  that  of  the  silex,  1*43,  we  obtain  '67  as  the 
measure  of  the  visibility  of  fine  diatom  markings  in  solution  of 
2)hospJiorus,  which  is  six  times  as  great  as  that  of  the  same  object 
in  balsam,  and  no  less  than  50  per  cent,  higher  than  its  visibility 
in  air  itself — whilst  the  greater  brightness  of  the  diffraction  spectra 
will  make  the  more  refrangible  rays  effective,  and  thus  give  a 
greater  power  of  visual  (as  distinguished  from  photograjyhie) 
resolution. 

Summarized  we  get  the  following  results : — 

Table  showing  the  Visibility  of  Fine  Diatoms  when  Mounted  in  the 
FOLLOWING  Media,  securing  the  full  Aperture  of  Objective. 

Water         10 

Canada  balsam         11 

Bisulphide  of  carbon        25 

Solution  of  sulphur  in  bisulphide  of  carbon        . .     32 
Solution  of  phosphorus  in  bisulphide  of  carbon  ..     67 

The  practical  result  of  the  investigation  appears  to  be  that 
it  is  essential,  if  the  whole  aperture  of  an  objective  is  to  be 
utilized,  to  mount  minute  structures  in  some  medium  other  than 
air. 

*  Oil  of  cassia  gives  almost  exactly  the  same  result. 


On  the  Visibility,  &e.     By  J.  W.  Ste])henson.  567 

That  although  the  full  aperture  and  resolving  power  are 
secured  by  mounting  in  balsam,  it  gives  nevertheless  nearly  the 
faintest  image  of  all. 

That  a  solution  of  phosphorus  is,  as  far  as  visibility  is  con- 
cerned, by  far  the  most  effective,  but  the  difficulties  attending  its 
use  must  render  it  unpopular. 

The  next  best  is  a  solution  of  sulphur  in  bisulphide  of  carbon 
(although  pure  bisulphide  is  very  good),  and  with  these  there  is 
no  technical  difficulty  whatever. 

A  ring  of  the  aqueous  solution  used  by  Mr.  Browning  in 
making  his  bisulphide  prisms  being  formed  on  the  slip,  and  a  drop 
of  the  sulphur  solution  or  pure  bisulphide  being  placed  in  its 
centre,  nothing  is  necessary  but  to  place  over  it  the  thin  cover 
with  its  adhering  diatoms,  press  it  down  on  the  still  moist  ring, 
running  round  it  a  somewhat  copious  margin  of  the  cement,  and 
the  thing  is  done. 

In  a  short  time  the  glutinous  cement  sets  and  finally  becomes 
dry,  when,  in  order  to  protect  it  from  the  water  of  the  ordinary 
immersion  lenses,  it  is  desirable  to  give  it  a  coat  of  gold  size,  or 
shellac  varnish,  although  for  mere  keeping  purposes  this  is  un- 
necessary. 

The  same  course  may  be  adopted  in  mounting  in  phosphorus, 
except  that  the  solution  must  be  run  in  from  the  edge  of  the  thin 
cover  to  avoid  the  phosphoric  acid  which  rapidly  forms  on  its 
surface,  and  destroys  the  effect  wherever  it  comes  in  contact  with 
the  object.  I  have  found  varnish  made  of  the  best  red  sealing- 
wax  (which  is  better  than  pure  shellac)  as  useful  as  Browning's 
aqueous  cement  above  referred  to,  but  as  it  is  brittle  when  dry  it 
should  also  be  protected  by  a  coating  of  gold  size. 

There  are  now  on  the  table  objects  mounted  in  phosphorus  and 
bisulphide  of  carbon,  which  I  exhibited  in  1873,*  and  they  still 
remain  unchanged  notwithstanding  the  volatile  nature  of  the 
materials.  On  that  occasion  I  fell  into  the  error  of  saying  that 
there  was  a  loss  of  aperture  (instead  of  angle)  with  dry  objectives 
on  objects  mounted  in  phosphorus  and  bisulphide  of  carbon,  when 
in  fact  the  aperture  remained  unchanged. 

*  See  'Mon.  Micr.  Journ.,'  x.  (1873)  p.  1. 


568  Transactions  of  the  Societtj. 


XVIII. — On  the  Development  and  Betrogression  of  Blood-vessels. 

By  George  Hoggan,  M.B.,  and  Frances  Elizabeth  Hoggan, 

M.D. 

I^Rectd  Uth  April,  1880.) 
Plate  XV. 

At  the  present  day  it  is  not  necessary  to  hold  pessimist  ideas  in 
histology  in  order  to  admit  that  our  knowledge  of  the  manner  in 
which  blood-vessels  are  formed  is  still  unsatisfactory;  and. although 
for  the  last  thirty  years  the  most  eminent  histologists  have  sought 
to  elucidate  the  question,  it  may  fairly  be  said  that  the  very  latest 
opinions  enunciated,  differing  as  they  do  from  all  previous  ones,  are 
in  no  way  more  satisfactory.  Although  many  of  these  opinions 
appear  diametrically  opposed  to  each  other,  they  are  principally  so, 
it  seems  to  us,  in  being  too  exclusive  in  their  application;  and 
with  the  view  of  reconciling  them,  we  desire  to  put  on  record  a 
series  of  clearly  ascertained  facts  or  appearances  which  certain  new 
histological  processes  devised  by  ourselves  have  enabled  us  to  obtain. 
In  our  opinion,  the  general  disagreement  among  histologists 
upon  this  question  is  caused,  in  the  first  place,  by  the  unsuitability 
of  the  tissues  in  which  it  has  been  studied,  and  in  the  second  place, 
by  the  mode  of  preparation  employed.  Paradoxical  though  it  may 
appear,  we  have  learnt  from  experience  that  the  worst  place  in 
which  to  study  the  development  of  any  special  tissue  is  the  em- 
bryo itself.  There  the  embryonic  cells  are  so  little  differentiated 
from  each  other  in  shape,  the  intercellular  substance  or  matrix  is 
so  extremely  scanty,  while  the  process  of  developmental  growth  is 
so  rapid,  that  it  is  almost  impossible  to  obtain  a  clear  demonstra- 
tion. The  membranous  expansion  of  the  tail  of  a  living  tadpole, 
which  has  been  so  often  employed  for  this  kind  of  research,  and  from 
which  so  diametrically  opposed  views  have  been  deduced,  is  espe- 
cially unsatisfactory,  because  in  the  living  cell  no  nucleus  is  visible, 
and  the  polar  star  of  the  histological  explorer  being  invisible,  all 
true  ideas  of  direction  and  course  of  development  are  naturally 
enough  shrouded  in  obscurity.  For  our  part,  we  have  found 
nothing  so  suitable  as  the  growing  broad  ligament  of  pregnant  rats 
and  mice,  more  especially  during  a  first  pregnancy,  for  there  we 
have  a  fringe  of  developing  capillaries  lying  in  a  thin,  rapidly 
distending  membrane,  in  which  the  gelatinous  matrix  is  so  plentiful 
and  clear  that  every  vessel-forming  cell  stands  out  in  distinct 
relief.  In  that  membrane,  moreover,  the  silvei?  method  of  fixing 
and  marking  can  be  applied  most  favourably,  in  order  to  show  the 
junctions  of  the  cells  forming,  or  about  to  form,  the  blood-vessels,  in 
the  position  and  shape  they  possessed  when  alive. 


JOURK.R.MICR.  SOC.VOL  m.PL.Xy. 


iVtst  Mtvrrnar  &•  Cv  Uth 


Develoxinient  &Ket.T-»car»essi  on  oP  Blood- vessels. 


Development,  &c.,  of  Blood-vessels.    By  G.  and  F.  E.  Uoggan.  569 

The  animal  (by  preference  a  house  mouse)  ought  to  be  only 
moderately  well  nourished,  as  both  extremes  of  nutrition  defeat  our 
object,  either  by  obscuring  the  developing  vessels  by  fat-cells,  or 
preventing  the  vessels  from  being  formed.  It  ought  first  to  be 
gently  anaesthetized  by  chloroform  under  a  jar,  and  as  soon  as  it  is 
insensible,  it  ought  to  be  drenched  with  the  anaesthetic,  and  then 
left  to  die.  We  never  lose  time  by  injecting  the  animal  and  after- 
wards allowing  it  to  cool,  as  by  that  process  not  only  do  the  cells 
alter  in  shape,  but  the  injection  interposes  an  annoying  obstacle  to 
vision  when  it  has  filled  the  vessels. 

As  soon  as  it  is  dead,  we  open  up  the  abdomen  along  the  linea 
alba,  so  as  to  completely  expose  the  gravid  uterus,  and  then  seizing 
the  uterus  of  one  side  with  fine  pointed  forceps,  we  raise  it  out  of 
the  body  cavity,  so  as  gently  to  distend  the  membrane  or  broad 
ligament  which  attaches  it  to  the  abdominal  wall.  On  one  side 
of  this  membrane  we  place  the  smaller  of  a  pair  of  the  histological 
rings  invented  by  us,  and  already  described  in  this  Journal ;  *  and 
without  allowing  it  to  glide  or  rub  over  the  surface,  we  place  the 
larger  of  the  two  rings  upon  the  smaller.  In  this  way  a  miniature 
tambomine  is  formed ;  and  after  the  two  rings  have  been  carefully 
jammed  one  on  the  other,  by  a  slight  circular  movement,  the  excess 
of  membrane  can  be  snipped  ofi"  external  to  the  rings,  and  a  one- 
half  per  cent,  solution  of  silver  in  distiUed  water  poured  upon 
either  or  both  surfaces,  without  preliminary  washmg ;  but  after  a 
few  minutes  exposure  to  a  dull  light,  the  whole  may  be  gently 
washed  with  ordinary  water. 

In  our  piece  of  membrane  not  only  are  the  cells  fixed  in  their 
living  shape,  but,  as  the  blood-vessels  were  full  of  blood  when  the 
one  ring  was  jammed  upon  the  other,  the  distending  blood  was 
thus  retained  within  them,  and  the  silver  solution  now  fixes  them 
in  this  condition,  and  makes  also  the  outlines  of  the  cells,  which 
alone  form  them,  distinctly  visible.  The  membrane  is  now  ready 
for  staining,  the  best  of  all  methods  for  this  purpose,  according  to 
our  experience,  being  the  one  invented  and  published  by  one  of  us. 
By  this  method  the  membranous  portion  of  the  tambourine  is  first 
soaked  for  a  few  minutes  in  methylated  spirit,  a  teaspoonful  in  a 
watch-glass  or  small  saucer  being  suflicient.  This  is  then  pourtxl 
away,  and  in  its  stead  a  few  drops  of  a  2  per  cent,  solution  of  per- 
chloride  of  iron  in  spirit  is  filtered  upon  the  membrane.  After  a 
few  minutes  a  2  per  cent."  sohition  of  pyroi^'allic  acid  in  spirit  is 
next  filtered  upon  it,  and  allowed  to  remain  tlu're  from  a  few 
seconds  to  a  few  minutes,  according  to  the  depth  of  tint  reipiireil, 
and  then  the  whole  is  well  washed  with  ordinary  water,  and  tho 
staining  process  is  complete.  A  few  drops  of  glycerine  may  then 
be  phicecl  u[)on  tho  membrane  to  clarify  it,  and  the  preparation 
•  Sec  vol.  ii.  (I87'.i)  !».  W.u. 


570  Transactions  of  the  Societtj. 

may  be  studied  at  once  under  the  Microscope,  or  mounted  on  a 
slide  as  a  permanent  preparation. 

It  may  with  equal  facility  be  rendered  transparent  by  alcohol 
and  an  essential  oil,  and  mounted  in  balsam  or  copal  varnish,  but 
it  then  possesses  all  the  disadvantages  of  a  balsam  preparation. 
Under  all  circumstances,  the  membrane  must  be  clarified  before  it 
is  excised  from  the  rings,  to  prevent  unequal  contraction.  It  is 
easily  excised  by  running  the  edge  of  a  knife  round  the  outer  rim 
of  the  inner  ring,  and  having  prepared  a  slide  previously  with  a 
drop  of  glycerine  upon  it,  the  disk  of  membrane  remains  in  place 
when  applied  to  it ;  the  glass  cover  may  then  be  put  on  and  sealed, 
as  we  do  it,  by  hot  sealing-wax  dropped  round  the  edges,  and 
trimmed  with  a  hot  wire  while  the  whole  is  compressed  by  a  paper- 
clip. 

We  have  thus  a  preparation  mounted  in  glycerine,  in  which  no 
undue  distension  has  taken  place,  to  whose  surface  no  injury  has 
been  done  during  the  whole  course  of  preparation,  and  whose 
progress  at  every  stage  could  be  examined  under  the  Microscope 
without  damaging  it.  Moreover,  when  mounted  in  glycerine  the 
blood  leaves  the  vessels  when  the  disk  is  excised,  and  is  washed 
away  at  the  edges  with  the  excess  of  glycerine,  so  that  all  the 
vessels  appear  as  rigid,  hollow  tubes,  the  thickness  of  whose  walls 
and  the  joints  and  nuclei  of  the  cells  composing  them,  can  be 
equally  well  seen  by  the  silver  and  pyrogallate  of  iron  processes  we 
have  used. 

As  an  admirable  little  review  of  the  opinions  already  arrived  at 
by  difterent  observers  on  the  question  of  the  development  of  blood- 
vessels, has  lately  been  given  by  Dr.  George  Thin  in  '  The 
Quarterly  Journal  of  Microscopical  Science '  for  July,  1876,  we 
think  it  inadvisable  to  lengthen  out  this  paper  by  any  recapitula- 
tion of  them.  With  regard  to  even  the  latest  views.  Dr.  Thin 
states : — "  The  conclusion  to  which  I  have  therefore  come  is,  that 
the  cellules  vasoformatives  of  Eanvier  are  spaces  in  the  omentum, 
to  which,  I  submit,  the  term  '  cell '  is  not  applicable.  The  develop- 
ment of  blood-vessels  takes  place  by  an  escape,  first  of  fluid,  and 
finally  of  the  formed  elements  of  the  blood  from  the  vascular 
system  into  these  spaces.  The  establishment  of  the  blood  current 
is  speedily  followed  by  the  formation  of  a  membranous  wall  around 
the  current,  which  is  impermeable  for  an  injection  mass  or  the 
blood,  and  the  process  is  complete." 

We  are  careful  to  give  Dr.  Thin's  views  in  his  own  words,  as 
they  are  the  latest,  to  our  knowledge,  which  have  appeared  in 
English.  They  are  opposed  to  the  views  of  all  previous  observers, 
and  they  are  equally  opposed  to  all  the  facts  we  have  ascertained 
and  are  about  to  state  in  this  paper.  Indeed  we  fail  to  understand 
how,  if  he  has  used  the  silver  process,  he  has  overlooked  the  fact 


Development,  dte.,  of  Blood-vessels.    By  G.  and  F,  E.  Hoggan.    571 

that  portions  of  capillaries  show  the  junction  markings  of  the 
hollow  cells  composing  them,  before  ever  they  have  become  con- 
nected with  the  circulation. 

We  have  found  that  a  new  development  of  blood-vessels  takes 
place  solely  by  the  aid  and  addition  of  the  wandering  cells.*     In 
the  membranous  sheet  under  consideration,  the  only  cells  present, 
apart  from  the  layers  of  endothelium  covering  the  two  surfaces  of 
the  rapidly  growing  tissue,  are  the  wandering  cells.     They  may  be 
seen   here   in   at   least   three   conditions.      They   may   be   found 
wandering  purposeless  over  the  free  surface  of  either  layer  of  endo- 
thelium, or  through  the  soft  gelatinous  matrix  forming  the  mem- 
brane  between   these  layers.     If  the   tissue   has   been   properly 
prepared,  they  are  generally  found  branched  in  the  latter  locality, 
although  on  the  free  surfaces  they  have  retracted  into  a  globular  or 
circular  form,  being  surrounded  by  no  matrix  to  retain  them  in  the 
branched  condition  when  the  silver  is  applied  to  fix  them.     If  the 
animal  has  been  injected  and  left  to  cool  before  it  is  opened,  and  the 
silver  solution  be  then  applied,  they  will  probably  appear  round  in 
shape  within  the  matrix,  and  very  plentiful  on  the  free  surfaces  in 
the  same  form ;  or  they  may  be  found  developing  into  fat-cells  in  the 
neighbourhood  of  the  blood-vessels,  in  which  condition  they  may 
either  appear  round  or  with  matiij  branches,  according  to  the  condi- 
tions of  preparation  already  referred  to.     They  may  have  more  than 
one  nucleus  in  the  purely  wandering  condition,  but  they  have  not 
more  than  one  nucleus  as  a  rule  when  developing  into  a  fat-cell. 
Again,  they  may  be  found  placing  or  having  placed  themselves  in 
position  to  form  or  to  strengthen  a  blood-vessel  in  course  of  deve- 
lopment.   The  methodical  manner  in  which  this  is  effected  would 
almost  argue  an  instinct  or  intelligence  worthy  of  higher  animals ;  and 
although  the  directions  the  cells  move  in  when  forming  the  new 
vessel   may  be   manifold,  they   seem   to  follow   a  regular  course 
throughout.     They  may  either  plant  themselves  at  a  point  in  a 
blood-vessel  where  a  connection  is  to  be  formed,  and  prolong  their 
protoplasmic  cell  substance  to  join  hands  with  another  cell  liuk  in 
the  chain  of  capillary  development,  as  at  a,  Fig.  9  (Plate  XV.),  and 
e,  Fig.  8,  or,  as  is  more  common,  they  may  appear  external  to  the 
future  point  of  junction,  and,  stretching  towards  it  their  proto- 
plasmic arm,  thus  complete  the  connection.  This  peripheral  position 
may  be  either  in  direct  linear  continuation  of  a  new  vessel,  as  at  d, 

•  Wc  tliink  it  unnecessary  that  we  should  aguin  enter  at  any  lengtli  into  the 
rcasims  we  have  jdready  piven  in  our  furnior  nrtiolu  on  tlic  Fut-cell,  for  rejecting 
tlic  liypotliesis  that  tlio  fixctl  cc-\U  of  the  connective  tinsue  have  any  Bliare  in  tlio 
fornialion  of  blood-vo8.s.  Is,  fat-cclLs,  &c.  We  cannot  admit  tiiat  any  fixed  cell  of 
any  tis.sue  can  normally  devcloj)  directly  into  the  fixed  cell  of  any  other  tissue. 
A  "ciinecr  cell  may  indeed  impress  its  charact<r  u|ion  any  lixed  or  ond)ryonic  cells 
near  it,  so  that  these  also  Income  cancer  cells;  hut,  normally,  fixed  cells  can  only 
arise  from  or  return  to  emhryouic  cells. 


572  Transactions  of  the  Societtj. 

Figs.  4,  5,  and  6,  or  at  right  angles  to  it,  as  at  a,  Figs.  1  and  2,  and 
i,  Fig.  12.  Strange  to  say,  in  tlie  latter  condition  the  already- 
existing  blood-vessel  or  capillary  seems  always  ready  to  meet  such  an 
advance  half-way,  and  will  either  bend  its  whole  tube,  in  the  case  of 
a  capillary,  or  dimple  its  cellular  wall,  in  the  case  of  a  larger  blood- 
vessel, towards  the  vessel-forming  cell,  as  seen  in  the  examj)les  last 
named. 

It  is  also  worthy  of  notice  that,  when  we  examine  the  membrane 
in  the  vicinity  of  such  a  cell,  we  find  that  no  other  cell  is  as  yet  in 
position  to  continue  the  process  of  development ;  that,  in  short,  the 
solitary  vessel-forming  cell  has  specially  come  to  place  itself  in  the 
most  favourable  position  to  enter  into  the  continuation  of  the  vessel 
peripherally,  and  acts  there  until  another  cell  may  come  and  place 
itself  beyond  it  to  continue  the  process.  But  the  most  wonderful 
instinct  of  all  is  seen  when  a  large  capillary  loop  is  about  to  be 
formed,  when  several  cells  are  seen  placing  themselves  at  considerable 
distances  from  each  other  in  the  precise  line  which  the  future  vessel 
is  to  occupy.  This  is  well  seen  in  Fig.  12,  A,  which  shows  under  a 
power  of  100  diameters  a  plan  of  such  a  loop  about  to  be  formed 
between  a  and  h,  the  nodal  points  in  already  formed  capillaries, 
where  attachments  to  the  circulation  are  to  be  formed.  In  this 
loop  or  chain,  independently  of  the  cells  at  a,  h,  and  c  already 
attached  to  the  capillaries  (all  the  component  cells  of  this  chain  are 
drawn  separately  in  the  same  figure  at  a  much  higher  power)  we 
have  four  links  formed,  three  of  them  consisting  as  yet  of  only 
single  cells  e,  f,  and  h,  and  one  link  g,  consisting  of  three  cells, 
two  of  which  are  already  vacuolating  or  hollowing  out  to  form  a 
tube  before  any  connection  is  made  with  the  comparatively  distant 
blood-vessels.  Indeed  this,  the  most  advanced  link  of  the  chain,  is 
almost  equidistant  from  the  nodal  points  of  junction  at  a  and  h.  It 
will  also  be  observed  that  while  gig',  the  cells  which  specially 
hollow  out  to  form  the  tube,  join  by  overlapping  their  ends,  or,  in 
other  words,  by  forming  a  splice,  the  third  cell  g"  places  itself 
upon  the  splice  or  junction  of  the  cells,  and  therefore  at  the 
weakest  point,  by  way  of  strengthening  the  whole.  This  splicing 
of  cells  and  application  at  the  point  of  junction  of  strengthening 
cells  we  have  found  invariably  throughout,  as  will  be  seen  also  in 
all  the  other  figures.  Another  point  of  interest  at  this  spot  is  the 
position  or  presence  of  a  fibre  or  fibres  which  seem  to  connect  the 
cells  together  and  with  the  nodal  points,  or,  in  other  words,  to 
mark  out  the  line  of  the  future  vessel. 

Let  us  next  consider  the  action  or  behaviour  of  a  single  cell 
when  about  to  develop  into  a  blood-vessel,  and  let  us  choose,  in  the 
first  place,  a  single  cell  joining  itself  at  right  angles  to  an  existing 
blood-vessel  or  capillary  from  what  seenls  to  be  a  perij)heral  direc- 
tion ;  but  while  we  say  seems,  we  do  not  wish  to  say  that  such  is 


Development,  &e.,  of  Blood-vessels.   By  G.  and  F.  E.  Eoggan.    573 

the  actual  condition,  as  will  afterwards  appear.  For  convenience' 
sake,  let  us  commence  with  Fig.  1,  where  we  see  a  spindle-shaped 
or  bipolar  cell,  a,  forming  a  junction  with  a  comparatively  large 
blood-vessel  h.  We  speak  of  cell  a  as  bipolar,  because  it  has 
stretched  out  one-half  of  its  protoplasm  peripherally  on  one  side, 
while  the  other  half  is  stretched  out  centrally  in  connection  with  the 
blood-vessel.  We  may  also  note  here  that  whatever  shape  a 
wandering  cell  may  possess  before  it  makes  up  its  mind  to  enter 
into  the  composition  of  a  blood-vessel,  no  sooner  is  that  settled  than 
it  assumes  the  elongated  form,  being  either  unipolar  or  bipolar  from 
the  nucleus,  and  in  no  case  yet  have  we  seen  a  many-branched  or 
stellate  cell  entering  into  connection  with  a  developing  blood-vessel. 
In  Fig.  1  we  also  notice  that  the  wall  of  the  blood-vessel  is  bulged 
out  at  its  attachment  to  the  protoplasm  of  the  peripheral  vessel- 
forming  cell,  a,  and  the  question  is  an  open  one  whether  the  bulging 
is  the  result  of  sympathy  on  the  part  of  the  vessel  towards  the  cell 
a  approaching  from  the  periphery,  or  whether  the  bulging  merely 
marks  the  spot  where  the  cell  a  actually  passed  through  the  vessel- 
wall  from  its  interior  foiuards  the  periphery  to  take  its  place  where 
it  is  now  seen. 

Passing  on  from  Fig.  1,  let  us  follow  up  the  process  in  Fig.  2, 
which  takes  us  on  a  stage  further  in  the  same  direction.  Here  we 
have  a  cell,  a,  also  lying  at  right  angles  to  the  existing  vessel,  in 
this  case  a  capillary,  which  has  not  merely  bulged,  but  actually 
bent  its  tube  towards  cell  a.  This  cell  may  also  be  called  bipolar, 
although  the  great  bulk  of  its  protoplasm  lies  between  the  capillary 
and  the  nucleus,  which  latter  lies  twice  as  far  from  the  capillary  as  in 
Fig.  1,  or,  if  we  consider  the  direction  of  movement  to  be  reversed, 
it  has  passed  twice  as  far  from  the  vessel  as  cell  a,  Fig.  1.  We 
see  here  also  two  points  of  interest  already  referred  to  as  illustrating 
fixed  laws  throughout : — 1st,  The  point  of  the  attached  cell  is  not 
applied  directly  at  right  angles  to  the  vessel,  but  lies  alongside  of  it 
(as  was  also  the  case  in  Fig.  1 ),  and  in  the  second  place,  at  the 
weakest  part  of  the  joint  thus  formed,  we  see  the  cell  c  placing 
itself  so  as  to  strengthen  the  newly-formed  joint  or  splice.  Let  us 
next  pass  to  a  more  advanced  stage,  as  seen  in  i,  Fig.  12,  where 
the  cell  is  applied  to  a  formed  vessel,  as  in  Figs.  1  and  2.  Here 
we  have  the  joint  strengthened  b}'  the  application  of  another  cell,  as 
in  Fig.  2,  and  we  have  the  first  traces  of  another  important  feature, 
the  formation  of  the  vacuole,  or  hollowing  out  of  the  cell  whose 
protoplasm  is  to  form  the  capillary  wall.  It  is  to  be  seen  as  a  small 
white  spot  lying  close  to  the  nucleus  on  the  side  next  the  capillary, 
and  will  go  on  increasing  in  size  until  either  directly  or  by  the 
medium  of  an  additional  cell  it  forms  a  connection  with  the  cavity 
of  the  formed  vessel. 

A  fourth  stage  is  scon  in  Fig.  3,  where  not  only  has  the  cavity 


574  Transactions  of  the  Society. 

of  vacuolation  become  larger  than  in  i,  Fig.  12,  and  its  junction 
with  the  capillary  strengthened  by  the  addition  of  two  cells  h 
and  c,  but  already  at  its  peripheral  pole  it  has  formed  a  connec- 
tion in  direct  linear  series  with  another  bipolar  cell,  d,  which  has 
arrived  at  the  same  degree  of  development  as  a  in  Fig,  1.  We 
shall  hereafter  refer  to  the  bodies  seen  within  the  vacuole ;  in  the 
meantime  we  have  to  notice  that  the  vacuole  has  not  become  con- 
tinuous with  the  cavity  of  the  capillary,  but  this  last  phase  is  seen 
between  a  and  6,  Fig.  11,  where  the  cavity  is  continuous  with  the 
lumina  of  the  vessels  to  which  they  are  attached. 

So  far  we  have  traced  the  history  of  the  development  of  a 
wandering  cell  into  the  first  link  of  a  developing  blood-vessel.  The 
formation  of  the  second  link  includes  the  process  of  prolongation  of 
a  blood-vessel  by  a  cell  in  direct  linear  continuation.  Cell  d  in 
Figs,  3  and  4,  represents  the  first  stage,  in  which  nothing  particular 
is  to  be  remarked  beyond  what  we  have  already  described.  But  in 
d,  Fig.  5,  we  have  a  stage  further  advanced ;  a  cavity  has  already 
vacuolated  in  the  direction  of  a,  the  cell  also  vacuolating  to  which 
it  is  attached  on  the  side  next  to  the  blood-vessel. 

We  may  here  call  attention  to  an  interesting  peculiarity  gene- 
rally observed  in  cells  vacuolating  to  form  blood-vessels.  Cell  d, 
having  as  yet  no  cell  on  its  peripheral  end  or  pole,  has  thrown 
the  whole  of  its  protoplasma  into  the  duty  of  forming  an  attach- 
ment with  cell  a  on  its  central  aspect;  and  for  the  same  reason 
the  cavity  of  vacuolation  is  formed  on  the  central  side  of  the 
cell  nucleus,  while  cell  a,  which  wishes  to  form  a  connection  cen- 
trally with  h  and  peripherally  with  d,  has  vacuolated  at  both  sides 
or  ends  of  its  nucleus.  Cell  i,  Fig.  12,  showed  the  earliest  stage 
in  the  carrying  out  of  this  principle,  and  we  may  see  the  third 
stage  in  cell  d,  Fig.  6,  whose  vacuolated  cavity  at  the  attached 
side  of  its  nucleus  has  formed  a  junction  with  the  cavity  of  the  cell 
a,  to  which  it  is  attached  centrally,  and  which,  having  vacuolated 
before  forming  any  attachment  to  cell  h,  shows  the  vacuolation 
only  on  that  side  of  the  nucleus  nearest  to  its  peripherally  attached 
neighbour  cell  d. 

In  Fig.  7  we  have  the  same  process  another  stage  further  on, 
where  not  only  have  the  vacuolated  cavities  in  a  and  d  become 
connected,  but  they  have  gone  on  extending  themselves  beyond 
their  respective  nuclei  both  centrally  and  peripherally ;  and  further, 
the  oblique  splice  or  union  between  a  and  d  has  been  strengthened 
at  its  weakest  point  by  the  addition  of  cell  c  placed  according  to  the 
usual  rule.  In  this  figure  the  dotted  line  represents  the  continua- 
tion of  the  black  silvered  line  that  marks  the  union  of  the  two  cells 
a  and  d  on  the  opposite  surface  of  the  tube.  In  all  these  examples 
it  will  be  observed  that  we  never  have  cells  joining  on  the  end-to- 
end  principle,  as  stated  by  Arnold,  but,  as  a  rule,  they  overlap  each 


Development,  &e.,  of  Blood-vessels.    By  G.  and  F.  E.  Roggan.  575 

other,  as  stated  by  Golubew,  whether  the  junction  is  effected  at 
right  angles,  as  in  Figs.  1  and  2,  or  in  direct  Hnear  continuation,  as 
in  Figs.  6  and  7. 

Hitherto  we  have  been  principally  engaged  with  cells  forming 
attachments  at  or  from  the  perij)hery  to  blood-vessels.  Let  us 
now  study  those  cases  where  the  cells  appear  to  be  attached  to  or 
at  the  blood-vessels,  and  stretch  out  from  them  to  form  a  junction 
with  cells  lying  unattached.  Cell  a,  Fig.  9,  seems  to  offer  a 
suitable  example  where  the  cell  seems  to  make  the  capillary  its 
base  of  operation,  from  which  it  stretches  to  form  an  angular 
junction  with  cell  d,  the  peripheral  point  of  another  capillary. 
But  on  the  other  hand,  cell  a,  Fig.  9,  may  be  held  to  form  the 
next  stage  to  cell  a,  Fig.  1,  supposed  to  be  going  in  an  opposite 
direction,  that  is  to  say  from  the  periphery  to  the  blood-vessel 
centrally.  In  other  words,  it  is  difficult  or  impossible  to  determine 
whether  cell  a,  Fig.  1,  should  follow  cell  a,  Fig.  9,  as  a  type  of 
cells  acting  or  passing  from  the  capillary,  or  cell  a,  Fig.  9,  ought 
to  follow  cell  a,  Fig.  1,  as  a  type  of  cells  passing  to  the  capillary. 
We  may  leave  the  question  undecided,  for  it  does  not  really  much 
matter,  and  it  is  only  useful  in  serving  to  reconcile  the  opposing 
views  of  Kolliker  and  Golubew  as  to  whether  it  was  by  a  cell 
passing  to  or  passing  from  the  capillary  that  new  vascular  exten- 
sions were  formed. 

If,  however,  we  still  follow  the  process  in  the  sense  that  cell  «, 
Fig.  9,  is  a  type  of  cell  acting  at  or  from  the  blood-vessels,  we  may 
find  an  undoubted  example  of  the  same  principle  in  cell  e,  Fig.  8, 
which,  while  lying  upon  the  capillary,  has  begun  to  stretch  out  a 
short  fine  process  of  its  protoplasm  towards  a  wandering  cell,  /,  of  a 
circular  form,  which  has  not  yet  begun  to  elongate  its  protoplasm 
into  the  invariable  bipolar  shape  which  characterizes  the  wandering 
cell  when  it  has  undertaken  the  duty  of  a  vessel-forming  cell. 
Cells  m  and  n,  Fig.  12,  arc  very  good  examples  of  this  direction  of 
development,  and  cell  h  is  even  more  typical,  because  it  has  not  yet 
begun  to  send  out  any  process  peripherally.  It  must,  therefore, 
appear  abundantly  evident  that  the  process  of  prolongation  of 
newly  forming  blood-vessels  by  cells  may  bo  either  towards  or 
from  the  vessels.  We  have  shown  that,  although  cell  a  in  Figs.  1, 
2,  and  9,  and  i,  Fig.  12,  may  be  on  debatable  ground,  yet  such 
examples  as  cells  a  and  e,  Fig.  8,  are  undoubtedly  extreme  examples 
respectively  of  direction  of  growth  from  and  towards  the  blood- 
vessel. 

{Sometimes  we  have  cells  connecting  the  blood-vessels  before  the 
process  of  vacuolation  has  begun  in  them,  as  in  Fig.  10,  and  again 
we  may  lind  earlier  stages  than  that  seen  in  Fig.  1,  as  for  example 
in  cell/,  l''ig.  0,  which  is  evidently  only  approaching  the  capillary 
in  course  of  formation,  and  lying  at   right   angles  to  the  joint 


576  Transactions  of  the  Society. 

between  cells  a  and  h,  which  are  already  forming  the  bend  towards 
cell  /,  that  we  see  so  distinctly  marked  in  most  of  the  figures. 

The  manner  in  which  the  vessel-forming  cell  vacuolates  or 
hollows  itself  out  so  as  to  form  a  tube  is  a  question  of  great 
importance,  which  is  not  yet  thoroughly  understood,  judging  from 
the  difi'erent  opinions  held  by  observers.  This  divergence  in 
opinion  is,  we  believe,  to  be  accounted  for  by  the  fact  that  there 
are  several  different  processes  included  under  the  head  of  vacuola- 
tion,  differing  in  their  course  and  results,  although  one  process  may 
be  often  found  passing  into  another. 

When  a  fixed  cell  passes  into  the  embryonic  form,  as  in  the 
case  of  an  inflamed  epidermic  or  cartilage  cell,  or  when  the  cell  of 
embryonic  cartilage  vacuolates  to  make  way  for  the  development  of 
bone,  there  is  always  a  plentiful  formation  of  new  or  young  cells 
within  the  mother-cell ;  but  although  these  processes  have  certain 
features  in  common  with  the  vacuolating  vessel-forming  cell,  they  are 
in  other  respects  unlike  it.  Again,  we  have  a  different  process  in 
the  pathological  vacuolation  of  cells,  as  we  have  shown  it,  for 
example,  in  the  sweat-glands  in  leprosy,  in  which  condition  there  is 
no  proliferation  or  formation  of  new  cells,  but  a  cavity  is  formed 
between  the  nucleus  and  the  cell  protoj)lasm,  which  increases  until 
it  bursts.  This  vacuolation  seems  to  have  the  effect  of  separating 
the  nucleus  from  the  rest  of  the  cell  substance,  and  thus  leads  to 
death  of  the  individual  cell.  In  such  cases,  the  nucleus  may  be 
either  compressed  against  the  cell  protoplasm  forming  the  wall  of 
the  vacuole,  appearing  like  the  seal  of  a  signet  ring  when  viewed 
edgeways,  and  almost  normal  in  shape  when  viewed  from  the  front, 
or  it  may  appear  distorted  and  floating  loosely  in  the  fluid  of  the 
vacuole. 

With  neither  of  the  above  processes  does  vacuolation  of  the 
vessel-forming  cell  appear  to  be  identical,  although  we  have  some- 
times appearances  shown  apparently  analogous  with  both.  Thus 
in  g.  Fig.  12>  the  nucleus  appears  to  be  separated  from  the  cell 
protoplasm,  and  floating  loosely  hke  a  distorted  blood-corpuscle 
within  the  fluid  of  the  vacuole.  On  the  other  hand,  in  a,  Fig.  3, 
we  have  several  bodies  floating  within  the  fluid  of  the  vacuole,  but 
they  are  far  too  minute  to  be  mistaken  for  blood-corj)nscles.  It 
has  also  been  suggested  that  vacuolation  is  merely  the  formation  of 
fat  within  cells ;  but  this  is  certainly  not  the  case  with  the  vessel- 
forming  cells,  or  indeed  with  any  other  vacuolating  cell  we  are 
acquainted  with.  Apart  from  the  fact  which  we  have  shown,  that 
osmic  acid  blackens  the  fat  formed  in  cells  and  leaves  the  vacuolar 
fluid  transparent,  we  have  also  ascertained  that  in  a  developing  fat- 
cel]  the  nucleus  is  always  surrounded  by  the  protoplasm,  however 
thin  the  layer  may  be.  The  fat  is  therefore  formed  in  the  proto- 
plasmic substance  itself,  and  not  between  it  and  the  nucleus,  which, 


Development,  (&c.,  of  Blood-vessels.    By  G.  and  F.  E.  Iloggan.  577 

moreover,  is  never  found  floating  within  the  fat-globule,  so  that 
neither  chemically  nor  physically  is  there  any  resemblance  between 
the  fat-cell  and  the  vacuolating  cell.  Nor  have  we  ever  seen,  as 
stated  by  Schaefer,  a  vessel-forming  cell  of  a  round  form  vacuolate 
and  subsequently  elongate  itself.  Without  calling  his  statement  in 
question,  we  may  say  that  we  have  never  met  with  even  the  com- 
mencement of  a  vacuole  in  a  vessel-forming  cell,  until  after  it  had 
elongated  itself  and  clearly  made  up  its  mind  to  enter  into  the 
construction  of  a  blood-vessel.  Of  course,  if  the  cells  are  not  fixed 
in  the  living  form  by  the  precaution  we  have  referred  to,  they  are 
almost  certain  to  retract  into  the  round  form.  This,  indeed, 
occurred  in  some  of  the  preparations  we  made  for  this  research, 
from  which  drawings  were  made  before  we  detected  the  &ct  that 
the  cells  had  all  retracted  in  the  process  of  preparation ;  but  here 
there  was  no  question  of  subsequent  elongation. 

Bearing  in  mind  what  we  have  remarked  in  the  above,  let  us 
proceed  to  trace  the  process  of  vacuolation  in  vessel-forming  cells. 
At  i,  Fig.  12,  we  have  seen  that  the  vacuole  may  begin  and  be 
formed  almost  entirely  in  the  substance  of  the  cell  protoplasm, 
and  so  close  to  the  end  of  the  cell  nucleus  that,  were  it  not 
for  the  other  examples,  it  would  be  difficult  to  decide  whether 
or  not  it  touches  it.  In  such  a  case  the  nucleus  remains  evidently 
undisturbed  upon  the  protoplasm,  and  the  same  is  true  of  the 
nuclei  at  a  and  d,  Fig.  7.  In  other  cases  the  vacuole  may  form  so 
as  to  sever  the  connection  between  nucleus  and  cell  protoplasm,  as 
seems  to  have  taken  place  in  cell  g.  Fig.  12.  In  a,  Fig.  3,  on  the 
other  hand,  the  cell  evidently  possessed  more  than  one  nucleus,  or 
the  one  nucleus  has  broken  up  into  its  separate  constituent  bodies, 
as  shown  by  Pouchet,  the  one  condition  in  fact  being  only  less 
advanced  than  the  other.  At  all  events,  four  bodies  are  seen 
within  the  vacuole,  all  very  much  smaller  than  blood-corpuscles, 
but  one  of  them,  from  its  staining  less  intensely  than  the  other 
three,  seems  to  be  fixed  or  spread  out  normally  on  the  vacuole  wall, 
or  in  other  words  on  the  cell  protoplasm,  while  the  other  three 
appear  to  be  globular  in  shape  and  floating  loosely  within  the  fluid 
of  the  vacuole,  whence  they  would  probably  float  off  into  the 
general  circulation  when  connection  with  it  was  established.  This 
is  possibly  the  same  process  as  that  described  by  Kanvier  and 
Schaefer,  by  which  blood-corpuscles  are  formal  within  cells,  a 
hypothesis,  however,  the  correctness  of  which  we  arc  not  prepared 
to  admit,  for  those  floating  bodies  are  certainly  not  blood-corpuscles ; 
and  when  blood-corpuscles  are  found  within  cells  or  tubes,  as  in 
Figs.  13  and  IG,  we  are  prepared  rather  to  accent  the  alternative 
explanation  offered  by  the  former  histologist  tn£.t  such  cavities 
are  really  retrograding  blood-vessels,  in  portions  of  which  blood' 
corpuscles  have  become,  so  to  speak,  shut  up  or  imprisoned. 

VOL.  iir.  2  Q 


578  Transactions  of  the  Society. 

It  is  easy  to  imderstand  the  condition  seen  for  example  in 
Figs.  6  and  7,  where  the  nuclei  still  remain  normally  attached  to 
their  cell  protoplasm  which  is  to  form  the  wall  of  the  future  blood- 
vessel. But  what  is  to  become  of  ff,  Fig.  12,  when  its  nucleus 
floats  away  ?  Will  a  new  cell  take  its  place  when  the  circulation 
is  established,  or  will  the  unnucleated  protoplasm  remain  in  the 
same  position  ?  This  we  are  unable  to  detennine,  bnt  the  varied 
conditions  seen  in  the  different  examples  we  offer  lead  us  to  sup- 
pose that,  up  to  a  certain  stage,  there  is  an  analogy  between  the 
physiological  and  the  pathological  vacuolation  of  cells.  In  the 
vessel-forming  cell,  however,  the  accumulating  vacuolar  fluid  finds 
an  escape  into  the  circulation  before  much  damage  is  done  to  it ; 
but  there  is  no  vent  for  the  pathological  vacuolar  fluid,  and  it  there- 
fore ends  by  destroying  the  cell. 

We  have  already  referred  to  the  appearances  sometimes,  but  not 
always,  seen  where  a  line  of  elastic  fibre  marks  out  the  track 
subsequently  to  be  occupied  by  a  loop  of  blood-vessel.  Such  an 
appearance  is  shown  under  a  low  power  at  A,  Fig.  12,  where, 
however,  the  tint  of  the  fibres  has  been  purposely  exaggerated  for 
the  sake  of  distinctness.  It  is  not  our  intention  to  enter  into  the 
question  of  the  development  of  elastic  fibres,  of  which  so  little  that 
is  satisfactory  is  known  at  the  present  day,  but  rather  to  inquire 
into  the  relation  which  may  exist  between  them  and  the  cells  e,  f,  h, 
and  y,  which  lie  along  the  fine  of  fibre  or  fibres  and  represent  the  only 
links  as  yet  in  the  future  chain  of  blood-vessel.  After  premising 
that  these  fibres  are  only  a  few  of  the  many  elastic  fibres  which 
exist  at  that  spot,  but  which,  as  they  do  not  interest  us  at  present, 
we  have  not  drawn,  lest  they  should  confuse  the  appearances,  we 
have  first  to  ask  if  those  fibres  existed  before  the  cells  placed  them- 
selves upon  them,  and  if  so,  how  was  it  that  fibres  came  to  be 
placed  so  exactly  in  the  line  of  the  future  blood-vessel  ?  Were 
even  this  answered,  are  we  then  to  suppose  that  the  cells  e,  f,  g, 
and  h  clamber  along  the  fibre  from  the  nodal  points  a,  h,  and  c,  in 
the  existing  blood-vessel,  in  order  to  place  themselves  where  they 
are  especially  wanted  ?  All  these  and  a  host  of  other  questions  may 
be  asked  on  this  subject  which  our  present  knowledge  does  not 
enable  us  to  answer;  and  we  ourselves,  after  much  study  and 
examination  of  these  and  analogous  appearances,  have  come  to  one 
hypothetical  conclusion  which  seems  to  apply  to  them  all. 

We  do  not  believe  that  the  fibres  existed  there  before  the  cells, 
but  we  beheve  that  they  were  made  by  the  cells  as  these  passed 
into  position ;  that  just  as  a  slug  leaves  a  trail  of  slime  behind  it, 
those  wandering  cells  may  leave  a  trail  behind  them  of  a  substance 
which  is  known  afterwards  as  elastic  fibre,  and  that  this  tendency 
accounts  for  the  infinite  shapes,  sizes,  branches,  and  positions 
occupied  by  such  fibres.     We  distinctly  oiler  the  foregoing  merely 


Development,  &c.,  of  Blood-vessels.   By  G.  and  F.  E.  Hoggan,    579 

as  a  liypothesis,  but  a  hypothesis  which  seems  to  fit  all  the  various 
conditions. 

In  some  cases,  as  at  d,  Figs.  5  and  7,  the  terminal  vessel- 
forming  cell  is  not  continuous  with  a  fibre,  while  in  other  cases,  as 
at  a,  Fig.  1,  the  ceil  is  distinctly  continuous  with  or  prolonged 
into  a  fibre.  This  difierence  may  yet  be  found  sufficient  to  decide 
whether  the  cell  came  centrally  from  the  vessel  or  peripherally  to 
it.  The  further  growth  in  size  and  calibre  of  newly  developed 
capillaries  into  veins  and  arteries,  as  may  easily  be  conceived,  takes 
place  by  the  interposition  of  wandering  cells  between  or  upon  the 
already  existing  cells  of  the  wall.  >So  much  on  the  question  of 
development. 

Retrogression  of  Blood-vessels. 

While  the  process  of  formation  of  blood-vessels  may  be  held  to 
follow  the  same  course  under  all  circumstances,  retrogression  may 
take  place  from  several  causes  and  under  difierent  forms.  These 
forms  may  be  classed  under  the  two  great  heads  of  physiological 
and  pathological  forms  of  retrogression ;  but  it  is  not  our  intention 
to  enter  at  present  into  the  consideration  of  the  changes  which 
may  take  place  under  the  latter  head,  regarding  which  it  may  be 
sufficient  for  us  to  say  that,  under  pathological  conditions,  the 
cellular  elements  of  the  vessel  walls  may  undergo  either  degenera- 
tion or  malignant  changes,  which  entirely  alter  their  morphological 
appearances  and  destroy  their  physiological  properties. 

Confining  ourselves,  therefore,  to  physiological  causes  and  forms 
of  retrogression,  we  shall  direct  special  attention  to  changes  which 
result  from,  1st,  developmental,  and  2nd,  nutritive  causes  or 
conditions.  Ketrogression,  as  the  result  of  insufficient  nutrition, 
can  best  be  studied  in  connection  with  the  great  groups  or  tracts  of 
fat-cells  to  which  innumerable  blood-vessels  are  supplied  within  the 
same  serous  membranes  where  we  have  already  studied  their 
development.  As  the  tracts  of  fat-cells  disappear  by  physiological 
absorption,  either  from  want  of  food  in  a  young  and  active  animal 
or  through  deficient  power  of  assimilation  of  food  in  a  very  aged 
animal,  so  likewise  do  the  blood-vessels  which  supply  them  break 
up  and  disappear  when  their  presence  there  is  no  longer  necessary. 
In  both  these  instances  no  disease  is  present,  and  the  resulting 
retrogression  of  blood-vessels  -is  therefore  purely  physiological,  and 
unconnected  with  any  pathological  condition.  After  the  fat  has  Ijeen 
absorbed  i'rora  all  the  cells,  and  these  cells  themselves  are  passing 
away,  we  find  notable  changes  taking  place  in  the  whole  of  the 
blood-vessels  passing  to  or  snp|)lving  a  fat-tract. 

The  changes  taking  place  in  the  arteries  are  of  two  kinds.  If 
the  artery  is  directed  solely  towards  the  fat-tract,  we  find 
innumerable  irregular  constrictions  of  its  lumen,  the  muscular  coat 

2  Q  2 


580  Transactions  of  the  Society. 

at  some  parts  having  contracted  so  as  to  nearly  obliterate  that 
lumen,  leaving  moniliform  groups  of  dilatations  enclosing  numerous 
blood-corpuscles  along  its  course.  Very  often,  however,  the 
afferent  and  efferent  vessels  passing  to  and  from  the  capillary 
plexus  of  a  fat-tract  are  destitute  of  muscular  elements  in  their 
walls,  except  at  the  point  where  the  afferent  vessel  begins  as  a 
branch  passing  off  at  right  angles  from  an  artery  of  considerable 
size.  In  such  a  case  a  coat  of  muscular  fibres  extends  upon  it 
for  a  distance  of  five  or  six  diameters  from  its  point  of  junction 
with  the  artery,  so  that  when  it  is  no  longer  necessary  for  a 
nutrient  current  to  pass  towards  the  fat-tract,  this  sphincter-like 
muscular  coat  contracts,  and  thus  shuts  off  the  blood  current. 

The  changes  in  the  veins  or  vein-like  afferent  vessels  are  not 
less  strongly  marked.  These  vessels  contract  their  lumen  by 
causing  the  one  layer  of  cells  which  form  their  wall  to  contract 
laterally,  and  at  the  same  time  to  become  much  thicker,  so  that 
when  we  focus  the  Microscope  upon  the  plane  of  the  centre  of  the 
vessel,  we  find  the  lumen  obliterated,  and  the  cells  of  the  wall, 
instead  of  having  their  nucleus  standing  in  relief  from  the  inner 
surface  of  the  vessel,  now  appear  with  a  considerable  thickness  of 
their  protoplasm  covering  the  nucleus  on  the  internal  as  well  as 
upon  the  external  surface  of  the  vessel  wall.  This  contraction 
does  not  seem  to  be  due  to  any  nervous  influence,  but  may  in  great 
part  be  due  to  the  pressure  externally  of  the  gelatinous  matrix  in 
which  the  vessels  lie  embedded,  and  partly  to  their  own  proto- 
plasmic contractile  nature,  these  actions  being  permitted  by  the 
absence  of  the  distending  fluid  within  them. 

It  is,  however,  in  the  capillaries  that  the  best  marked  changes 
are  to  be  observed.  While  the  whole  capillary  plexus  supplying 
or  ramifying  in  a  tract  of  empty  fat-cells  contracts  the  lumen  of 
the  vessels  throughout,  it  is  only  the  loops  of  capillaries  forming 
the  outer  border  or  edge  of  the  plexus  which  first  retrograde  and 
break  up.  In  such  cases  we  may  observe  constriction,  or  what 
really  ought  in  most  instances  to  be  called  a  withering,  at  one  or 
more  points  on  the  course  of  the  loop,  the  capillary  wall  appearing 
to  become  much  thinner,  as  at  h,  h,  Fig.  15,  and  losing  the  plump 
cylindrical  appearance  seen  in  well  nourished  capillary  walls.  At 
the  same  time  the  withered  portion  seems  to  lose  its  faculty  of 
being  stained  by  certain  staining  agents  which  colour  satisfactorily 
those  portions  of  the  capillary  intervening  between  the  withered- 
like  constrictions.  Finally,  the  capillary  breaks  at  one  or  more 
places,  and  the  process  of  disintegration  is  carried  on  at  the 
extremities  of  the  free  ends,  one  cell  after  the  other  breakmg  off, 
as  at  a,  Fig.  19,  and  appearing  to  move  away,  by  means  of  long 
delicate  processes  or  branches,  from  the  seat  of  its  former  functions 
as  an  individual  element  in  a  capillary  wall. 


Develojp merit,  <&c.,  of  Blood-vessels.    By  G.  and  F.  E.  Hoggan.  581 

The  thinning  or  withering  of  the  wall  which  we  have  referred 
to,  is  evidently  a  process  of  absorption  of  the  excess  of  protoplasm 
which  the  cell  had  accumulated  after  it  had  taken  its  position  as  a 
part  of  the  capillary  wall  at  its  first  development  During  this 
absorption,  moreover,  particles  of  a  peculiar  fatty-like  substance 
show  themselves,  as  at  e.  Fig.  19,  on  the  absorbing  protoplasm, 
which  refuse  to  stain  with  colouring  reagents ;  but  when  logwood 
has  been  used  it  appears  of  a  yellowish-brown  colour,  in  strong 
contradistinction  with  the  blue  or  purple  tint  of  the  healthy  nuclei 
or  protoplasm. 

More  peculiar  still  is  the  relation  which  the  intercepted 
portions  of  capillary  bear  to  the  blood-corpuscles,  numbers  of  which 
in  many  cases  become  shut  up  in  such  intercepted  portions,  as  in 
Figs.  17  and  19.  For  the  purpose  of  studying  tlie  changes  under- 
gone by  those  blood-corpuscles,  we  especially  recommend  the 
pyrogallate  of  iron  staining  process,  for  while  the  nuclei  and  pro- 
toplasm of  the  healthy  elements  are  very  well  shown  by  it,  the 
blood-corpuscles  seem  to  have  a  special  affinity  for  the  colouring 
matter  and  stain  intensely  black,  so  that  there  is  no  difficulty  ia 
watching  their  behaviour  until  they  have  become  completely  ab- 
sorbed. This  faculty  of  staining  intensely  is  probably  due  to  the 
great  amount  of  iron  which  they  normally  contain,  but  whatever 
the  cause  may  be,  the  fact  is  very  evident.  The  change  which 
takes  place  in  these  elements  can  be  easily  followed,  even  if  it 
cannot  be  explained.  The  corpuscles  enclosed  in  a  portion  of 
capillary  undergoing  the  thinning  or  absorbing  of  its  protoplasm, 
are  seen  to  become  paler  and  transparent,  as  at  h,  Fig.  11),  and 
smaller  in  size,  until  a  point  is  reached  when  they  can  no  longer 
be  detected,  as  if  they  had  dissolved  away  within  the  absorbing 
protoplasm  of  the  capillary  cell,  and  no  vestige  of  them  remained 
behind.  It  is  highly  probable  that  the  yellowish  fat-particles,  c  c, 
Fig.  19,  already  alluded  to,  are  really  composed  of  a  modification  of 
the  blood  pigment  from  the  corpuscles,  a  point  we  have  not  the 
necessary  instruments  to  determine. 

This  reference  to  blood-corpuscles  within  intercepted  portions 
of  capillary,  leads  us  to  the  much  debated  question  of  the  presence 
of  blood-corpuscles  within  cells  already  referred  to,  and  of  the 
signification  of  those  appearances  in  what  have  been  named  vaso- 
formative cells  by  Professor  Kanvier,  with  regard  to  which  we  have 
also  given  Dr.  Thin's  opinion  that  they  are  merely  spaces  in  the 
omentum  to  which  the  term  cell  is  not  apjilicable.  This  question 
also  brings  us  to  the  consideration  of  the  retrogression  of  blood- 
vessels })hysiologically  in  connection  with  the  development  of  an 
animal.  Professors  Kanvier  and  Schutfer  independently  announced 
the  discovery  of  cells  containing  blood- corpuscles,  the  one  having 
Ibund  them  in  the  skin  of  embryo  rats,  ana  the  other  in  the  serous 


582  Transactions  of  the  Society. 

membranes  of  embryos  or  newly  born  animals.  Both  of  these 
histologists  described  these  cells  as  ultimately  becoming  connected 
with  or  forming  part  of  the  circulation,  but  the  former  has  specially 
studied  them  in  this  relation  and  given  to  them  the  name  they  now 
bear  of  "  vasoformative  cells." 

It  is  unnecessary  for  us  at  present  to  enter  into  his  arguments 
for  considering  these  structures  as  connected  with  the  development 
of  blood-vessels,  as  we  are  more  concerned  with  certain  remarks 
which  he  makes  at  page  633  of  his  '  Traite  d'Histologie,'  where  he 
advances  the  hypothesis,  only  to  reject  it,  it  is  true,  that  having 
regard  to  the  great  changes  continually  taking  place  in  the  circula- 
tion of  the  embryo,  and  after  birth  more  especially  in  connection 
with  the  obliteration  of  the  branchial  arches,  the  ductus  arteriosus, 
&c.,  it  may  be  plainly  argued  that  those  cavities  containing 
blood-corpuscles  are  really  portions  of  the  circulation  becoming 
obliterated,  and  that  the  intercepted  portions  are  really  parts  of 
pre-existing  capillaries. 

However  startling  such  a  hypothesis  may  appear  at  first  sight, 
we  are  surprised  to  find  Professor  Eanvier  reject  it  as  being 
inapplicable,  at  all  events,  to  most  of  the  examples  he  has 
studied.  For  our  part,  we  subscribe  fully  to  it,  not  as  a  hypo- 
thesis, but  as  a  fact,  for  there  is  certainly  in  this  research  no  fact 
easier  of  demonstration  than  it  is.     Our  reasons  are  the  followinof : 

O 

In  the  first  place,  there  is  complete  identity  between  these  vaso- 
formative (so-called)  cells  containing  blood-corpuscles,  and  the 
intercepted  portions  of  retrograding  capillaries  containing  blood- 
corpuscles,  in  animals  where  nutrition  has  been  insufiicient.  In 
the  second  place,  if  one  studies  the  omentum  of  newly-born  kittens, 
as  recommended  by  Kanvier,  nothing  can  be  clearer  than  the  fact 
that  retrogression  and  develoj)ment  of  blood-vessels  are  going  on 
side  by  side,  and  that  the  two  processes  are  so  distinct  that  there 
is  scarcely  any  possibility  of  confounding  the  one  with  the  other. 
We  give  a  drawing  of  such  an  example,  Fig.  13,  where  retrograding 
and  developing  vessels  are  lying  parallel  and  close  to  each  other, 
so  that  a  glance  ought  to  be  sufiicient  to  distinguish  between  them. 
In  this  camera  lucida  drawing  a,  a!  are  terminations  of  branches  still 
in  connection  with  the  original  channels  of  the  chculation,  and  6,  h' 
are  what  are  called  vasoformative  cells,  containing  blood-corpuscles, 
but  which  in  reality  are  portions  of  the  capillary  which  originally 
stretched  from  a  to  a',  and  are  now  identical  with  Figs.  15,  17, 
and  19,  from  a  rat  which  died  of  old  age  and  inanition.  In  Fig.  13 
we  also  see  a  new  vessel  c,  from  which  three  new  branches  d,  d',  d", 
are  being  developed,  in  conformity  with  the  process  we  described 
in  the  early  part  of  this  paper. 

It  is  therefore  evident  that  the  physiological  retrogression  of 
blood-vessels  follows  the  same  course,  whether  it  be  due  to  insuffi- 


Development,  dc,  of  Blood-vessels.    By  G.  and  F.  E.  Eoggan.  583 

cient  nutrition  or  assimilation  of  food,  on  the  one  hand,  or  to 
changes  in  the  development  of  an  animal,  on  the  other,  the  only 
peculiarity  being  that  while  in  the  latter  case  development  and 
retrogression  go  on  simultaneously  and  side  by  side,  in  the  two 
former  cases  only  retrogression  goes  on  at  one  time,  there  being  no 
room  or  reason  for  development,  just  as  during  development  of  blood- 
vessels in  the  adult  there  can  be  no  retrogression  at  the  same  time. 

Bearing  in  mind,  therefore,  the  small  bodies  sometimes  seen  in 
vacuolating  cells  during  the  formation  of  blood-vessels,  as  in  Fig  3, 
these  bodies  being  in  general  too  small  to  be  mistaken  for  blood- 
corpuscles,  we  have  come  to  the  conclusion  that  the  vasoformative 
cells  are  neither  cells  nor  cavities,  but  are  only  intercepted  portions 
of  a  retrograding  capillary  or  larger  vessel,  as  the  case  may  be, 
and  still  containing  the  blood-corpuscles  which  lay  within  the  vessel 
before  it  broke  up  into  fragments. 

The  results  of  this  research  may  be  summarized  in  very  few 
words.  When  new  blood-vessels  are  necessary,  the  wandering  cells 
come  and  plant  themselves  in  position  according  to  a  definite  plan ; 
through  these,  when  hollowed  out,  the  circulation  of  the  blood  is 
established  or  permitted.  When  the  blood-vessels  of  any  part  are 
no  longer  necessary,  they  break  up  into  their  individual  cells,  and 
these  separated  links  of  the  broken-up  chain  move  off  in  their 
original  condition  of  wandering  cells.  A  simple  cycle  of  life,  or 
functional  phase ;  much  simpler,  indeed,  than  the  cycle  we  have 
described  in  the  life  of  the  fat-cell  (a  companion  study  already  pub- 
lished in  this  Journal),  but  none  the  less  evident  because  it  is  simple. 


EXPLANATION  OF  PLATE  XV. 

(Drawings  and  preparations  by  the  authors.) 

The  first  fourteen  figures  illustrate  the  development  of  blood-vessels,  and 
Figures  13  and  15  to  19  illustrate  their  retrogre.ssiun.  Figures  11,  13,  and  IG  are 
from  the  omentum  of  the  newly  born  kitten ;  Figures  15,  17,  and  18  are  frum  the 
broad  ligament  of  the  r.it ;  the  re;<t  are  from  the  broud  ligament  of  pregnant  mice. 
They  have  all  been  stained  by  silver  and  pyrogallate  of  iron,  and  mounted  in 
glycerine. 

Fig.  1  shows  a  wandering  cell  a  forming  a  junction  with  a  blood-vessel  6, 
whicli,  as  if  in  sympathy,  has  dimpled  or  bulged  its  wall  towards  the  new  comer. 

Fig.  2. — A  similar  cell  «,  in  like  relationship  to  a  capillary  6,  but  in  a  stage 
further  advanced  than  Fig.  1.  In  this  case  the  capillary  has  bent  its  whole  tube 
in  sympathy.  A  second  cell  c  has  placed  itself  against  the  joint  as  if  to 
Btiengthen  it. 

Fig.  3. — A  still  further  advanced  condition,  in  which  a  second  cell-link  <i  has 
been  added  to  a ;  a,  moreover,  is  vacuolating,  and  shows  four  small  globular  IxKiics 
within  the  vacunle.     An  earlier  stage  of  vacunlution  is  seen  in  Fig.  12,  at  c  and  i'. 

Fig.  4. — A  still  further  advanced  coudition,  in  which  cells  a  and  rare  vacui'lat- 
ing  respectively  towards'',  the  proximal,  and  </,  the  distal  communication. 

Fig.  5. — A  similar  ctmdition  where  vacuolalion  has  been  going  on  in  cells  <i 
and  d  before  connection  is  established  with  the  capillary  '>. 

Fig.  G. — A  similar  condition  where  the  vacuoles  in  two  ct  ll.s  a  and  (/  have 
joined  to  form  one  cavity  before  forming  a  communication  with  a  tliinl  cell, 
vacuole  h  intervening  between  tlieni  and  the  capillary.  Th  ■  i.s. ijated  cell  /  1<>  the 
right  of  Fig.  1  belongs  to  this  figure.  [Fio.  7 


584  Transactions  of  the  Soaietij. 

Fig.  7. — A  similar  condition,  where  the  junction  of  two  cells  a  and  d  and  their 
vacuoles  forming  one  cavity  is  very  plainly  marked  by  silver  lines.  The  dotted 
line  represents  the  continuation  of  the  silver  marking  on  tlie  lower  surface  of 
the  tube  formed.  A  third  cell  c  has  placed  itself,  according  to  rule,  against  the 
joint  formed  by  a  and  d,  but  communication  has  not  yet  been  effected  with  the 
lumen  of  the  capillary. 

Fig.  8. — Shows  the  formation  of  a  capillary  plexus.  The  vacuoles  in  a  and  d, 
having  formed  one  cavity,  are  about  to  establish  a  communication  with  the  blood- 
vessel 6.  Three  cells  by  their  processes  are  forming  a  junction  at  g.  Cell  e  is 
stretching  out  a  process  to  form  a  communication  with  a  wandering  cell  /,  which 
has  not  yet  begun  to  elongate  its  protoplasm. 

Fig.  9  shows  a  junction  being  formed  at  an  acute  angle  by  cells  a  and  d,  so 
as  to  construct  a  loop  between  two  capillary  loops,  but  only  cell  d  has  vacuolated, 
and  it  has  not  yet  connected  its  cavity  with  the  circulation. 

Fig.  10. — A  similar  loop  between  two  capillary  loops  g  and  h,  being  formed  by 
three  cells  a,  b,  and  c,  none  of  which  has  as  yet  begun  to  vacuolate. 

Fig.  11. — A  branch  capillary  developing  in  accordance  with  the  plan  seen 
in  the  preceding  figures,  cell  a  having  vacuolated,  and  the  vacuole  being  about  to 
become  connected  with  the  lumen  of  the  blood-vessel  6.  This  figure  is  to  be 
compared  with  Fig.  1(3,  which  apparently  represents  retrogression,  both  figures 
being  taken  from  the  same  field  of  the  Microscope  in  a  preparation  of  the  omentum 
of  a  newly  born  kitten. 

Fig.  12  represents  the  formation  of  a  largo  capillary  loop  or  plexus.  At  A 
the  whole  plan  has  been  drawn  under  a  low  power  of  100  diameters,  while  the 
special  points  of  interest  have  again  been  drawn  at  tlie  same  high  power  as  the 
rest  of  the  drawings.  The  nodal  points  in  the  existing  capillaries  to  be  connected 
are  formed  at  a  and  at  h  and  c,  wliile  c,  f,  g,  and  h  represent  some  of  the  links  on 
the  future  chain.  Of  these  links,  g  is  formed  of  tliree  cells  joined  togetlier  in  the 
usual  plan,  and  of  these,  g  and  g'  are  vacuolating ;  a  nucleus-like  body,  resembling 
also  a  blood-corpuscle  seen  edgeways,  appears  to  float  free  in  the  vacuole  of  g. 

Fig.  13  shows  development  and  retrogression  of  vessels  going  on  at  the  same 
moment  and  in  the  same  field  of  the  Microscope,  owing  to  changes  in  the  circula- 
Intion  at  birth,  a  a',  terminations  of  a  retrograding  vessel  still  connected  with  the 
circulation ;  b  b'  portions  of  tlie  blood-vessel  formerly  continuous  from  a  to  a'  and 
still  containing  tlie  blond-corpuscles  e  e,  which  remained  in  them  at  the  moment  of 
separation ;  c  newly  developed  vessel  with  three  branches  d,  d',  d'',  in  course  of 
development ;  //,  nuclei  of  the  cells  of  the  wall  of  the  capillary. 

Fig.  14  shows  a  developing  loop  a  becoming  connected  with  the  circulation  at 
b  b',  the  component  cells  of  which  follow  the  rules  already  noticed. 

Fig.  15  shows  retrogression  of  blood-vessels  in  old  age,  and  failure  to 
assimilate  food,  which  was  plentiful.  The  loop  a  is  about  to  break  off  from  the 
circulation  at  6  6',  being  exactly  the  converse  of  Fig.  14;  blood-corpuscles  at  ee; 
nuclei  of  the  cells  forming  capillary  wall  at  //. 

Fig.  16. — A  drawing  under  higher  power  of  6'  Fig.  13,  representing  a  so-called 
vasoformative  cell,  but  in  reality  a  portion  of  a  retrograding  blood-vessel. 
Compare  with  developing  capillary  in  Fig.  11,  from  the  same  preparation. 

Fig.  17. — A  small  portion  of  a  long  capillary  loop  in  retrogression  (from  a  rat 
which  had  evidently  died  of  starvation),  being  the  portion  still  attached  to  the 
plexus,  but  shut  to  the  circulation,     e  e,  blood-corpuscles  ;  //,  nuclei  of  cell  wall. 

Fig.  18. — A  similar  portion  of  retrograding  capillary,  collapsed  throughout,  and 
undergoing  absorption.  It  is  about  to  break  up  into  its  constituent  cells  a  a.  From 
the  same  preparation  as  Fig.  17. 

Fig.  19,  from  the  same  animal  as  Fig.  15,  shows  a  portion  of  retrograding 
capillary  from  which  one  cell  a  is  about  to  separate  itself.  That  cell  contains  two 
blood-corpuscles  6,  nearly  absorbed,  c,  granular  matter  of  the  nature  of  fat  or  of  blood- 
pigment  ;  dd,  other  blood-corpuscles  still  normal ;  e  e,  nuclei  of  wall  of  capillary. 

Fig.  13  is  drawn  to  a  scale  of  170  diameters ;  Figs.  17  and  18  to  280  diameters ;  all 
the  others  under  the  same  power  of  330  diameters,  by  the  aid  of  the  camera  lucida. 


(     585     ) 


XIX. — On  a  ParahoUzed  Gas  Slide. 
By  James  Edmunds,  M.D.,  M.K.C.P.  Lond.,  F.K.M.S. 

dBead  9th  June,  1880.) 

This  is  a  simple  and  inexpensive  contrivance  which  has  been  made 
for  me  by  ]\Iessrs.  Beck  for  the  purpose  of  examining  bacteria, 
blood-globules,  &c.,  while  gases  or  vapours  of  various  kinds  are 
projected  into  an  annular  space  from  which  they  rapidly  diffuse 
into  an  object  which  is  being  observed  under  the  Microscope. 

The  slide  *  (Figs.  52  and  53)  is  constructed  of  a  shp  of  optical 
crown  glass  3  inches  by  l^,  and  in  thickness  from  three  to  four 
sixteenths  of  an  inch.     An  annular  zone  eleven- sixteenths  of  an 

Fig.  52. 


inch  in  diameter  and  nearly  one-eighth  inch  deep  is  turned  out 
of  the  slide,  so  as  to  leave  a  central  pillar  three-eighths  of  an  inch 
across,  and  the  top  of  this  pillar  is  then  turned  down,  so  as  to 


Fig.  53. 


leave  a  .  li  1  area  nearly  a  quarter  of  an  inch  in  diameter,  and 
exactly  on  a  level  with  the  general  surface  of  the  slide.  The  out- 
side of  the  central  pillar  is  then  smoothed  into  an  approximately 
paraboloidal  surface,  and  brought  to  an  optical  polish.  A  straight 
groove  of  the  same  size  and  depth  as  the  annular  zone  is  then  cut 
out  of  the  slide  parallel  to  its  long  side  and  at  a  tangent  to  the 
annulus.  Into  the  longitudinal  groove  of  the  slide  two  fine  glass 
tubes  are  cemented.     One  of  these  is  left  projecting  beyond  the  end 

*  Fi".  52  sliowH  flie  iippor  (isj^cpt  f>f  <he  sliilo  oxeiivatod  willi  the  ;;roovo 
and  iiimuluH,  tlio  totally  n  llcctiii;^  iiumlioliziMl  «rirfiico  of  thr  cciitnil  i>il!ar.  aii«l 
the  dtftr  central  area  left  on  a  level  with  the  top  of  the  sliile.  Vv^.  5;{  ;,'ive.s  :i 
longitudinal  ROction  of  the  slide  drawn  through  its  centre,  and  nhowin>^  the 
annular  gas  uhaunel,  the  central  paraboloid,  and  the  thiu  cover. 


586  Transactions  of  the  Society. 

of  the  slide,  so  as  to  be  connected  with  a  slender  elastic  tube  through 
which  gases  or  vapours  may  be  projected,  and  which,  after  traversing 
the  annulus,  escape  by  the  other  tube.  A  ring  of  olive  oil  is  set 
around  the  annulus  upon  the  surface  of  the  slide,  and  the  cover 
containing  on  its  centre  the  drop  of  liquid  to  be  examined  is  then 
so  placed  over  the  annulus  that  a  film  of  fluid  less  than  a  quarter- 
inch  in  diameter  lies  between  the  top  of  the  central  paraboloid  and 
the  cover,  while  the  margin  is  sealed  by  the  oil.  Thus  the  object 
may  be  examined,  firstly  by  itself,  and  afterwards  while  various 
gases  are  passed  through  the  surrounding  annular  space,  and  the 
changes  produced,  say  on  blood-disks  by  dry  or  moist  air,  alcohol 
vapour,  ammonia,  acetic  acid,  carbonic  acid,  &c.,  can  be  watched 
and  repeated  at  pleasure. 

If  light  be  thrown  into  the  central  area  from  beneath  by  means 
of  a  two-inch  objective,  the  object  is  seen  negatively  upon  a  bright 
field,  while  if  the  condenser  be  decentered  the  light  is  thrown 
upon  the  parabolic  surface  and  is  totally  reflected  into  the  object 
at  such  angle  as  to  give  a  positive  image  upon  a  black  background 
under  a  dry  eighth  or  sixteenth,  as  with  the  immersion  paraboloid. 
The  glass  tubes  may  be  cemented  into  the  groove  by  means  of  dough, 
putty,  jDlaster  of  paris,  shellac,  &c.  If  very  hot  sealing-wax  be 
used  the  slide  is  apt  to  crack,  unless  previously  heated  in  water. 
Diaphragms  of  black  paper  or  tin-foil  may  be  gummed  on  to  the 
lower  sm-face  of  the  slide,  so  as  to  stop  out  the  central  area  when 
black-field  observations  are  wanted.  Both  as  a  gas  slide  and  as  a 
simple  form  of  the  immersion  paraboloid,  it  works  conveniently  and 
efficiently. 


(  587  ) 
EECOED 

OF  CURRENT  RESEARCHES  RELATING  TO 

INVEETEBEATA,  CEYPTOGAMIA,  MICEOSCOPY,  &c.* 


ZOOLOGY. 


A.    GENERAL,  including-  Embryology  and  Histology 
of  the  Vertebrata. 

Development  of  the  Vertebrate  Eye.f  —  Professor  Lankester 
directs  attention  to  the  myelonic  or  cerebral  eye  which  the  Ascidian 
tadpole  possesses  in  common  with  all  Vertebrates.  All  other  animals 
which  have  eyes  develop  the  retina  from  their  ectoderm.  It  is  easy  to 
understand  that  an  organ  which  is  to  be  affected  by  the  light  should 
form  on  the  surface  of  the  body  where  the  light  falls.  It  has  long  been 
known  as  a  very  puzzling  and  unaccountable  peculiarity  of  Vertebrates, 
that  the  retina  grows  out  in  the  embryo  as  a  bud  or  vesicle  of  the  brain, 
and  thus  forms  deeply  below  the  surface  and  aioay  from  the  light.  The 
Ascidian  tadpole  helps  us  to  understand  this,  for  it  is  perfectly  trans- 
parent and  has  its  eye  actually  inside  its  brain.  The  light  passes 
through  the  transparent  tissues  and  acts  on  the  pigmented  eye,  lying 
deep  in  the  brain.  We  are  thus  led  to  the  conclusion — and  ho 
believes  this  inference  to  be  now  for  the  first  time  put  into  so  many 
words — that  the  original  Vertebrate  must  have  been  a  transparent 
animal,  and  had  an  eye  or  pair  of  eyes  inside  its  brain,  like  that  of 
the  Ascidian  tadpole.  As  the  tissues  of  this  ancestral  Vcrtebrato 
grew  denser  and  more  opaque,  the  eye-bearing  part  of  the  brain  was 
forced  by  natural  selection  to  grow  outwards  towards  the  surface,  in 
order  that  it  might  still  be  in  a  position  to  receive  the  influence  of 
the  sun's  rays.  Thus  the  very  peculiar  mode  of  development  of  the 
Vertebrate  eye  from  two  parts,  a  brain-vesicle  and  a  skin-vesicle,  is 
accounted  for. 

Embryolog^y  of  Batrachians.;}:  —  These  'New  Researches'  of 
Professor  Van  Eambeke  consists  of  two  jiarts :  (I.)  on  the  envelopes 
of  tlio  egg  and  external  embryonic  changes  of  Tritons  and  Axolotl, 
and  (II.)  on  the  cleavage  of  the  egg  in  Batrachians  generally. 

I.  1.  Having  in  a  previous  essay  described  the  egg  proper  (vitel- 
line splicro  or  globe)  the  author  now  distinguishes  its  five  envelopes 
as  (1)  the  vitelline  membrane,  (2)  chorion,  (3)  inner  capsule,  (-i)  outer 
capsule,  and  (5)  adhesive  layer.     The  first  is  thin  and  structureless, 

*  i^'  It  sliould  bo  understood  that  the  Society  do  not  liold  thonisolveH  respon- 
sible for  tlic  views  of  the  autliors  of  the  luipers,  &e.,  referred  to,  nor  fi>r  the  manner 
in  wliicli  tliose  views  may  be  expressed,  the  objiet  of  the  Kecord  Ix'inj^  to  present 
a  siimnmry  of  the  pajjcrs  us  acbialhi  published.  Objections  and  corrections  shouhl 
therefore,  for  tlie  most  pait,  be  address(  d  to  tiie  aullii>rs. 

+  'Degeneration:  a  rhapter  in  Darwinism  '  (8vo,  I/indon,  1S80). 

X  '  Arch,  dc  Biologie,'  i.  (1880;  pp.  305-380  (4  plates). 


588  RECOBD   OF    CURRENT    RESEARCHES   RELATING    TO 

closely  fitted  to  the  yolk,  with  little  projections  on  its  inner  surface, 
corresponding  to  the  vitelline  pores,  and  a  fold  applied  to  the  first 
meridional  groove.  The  chorion,  also  trans2)arent  and  homogeneous, 
tightly  invests  the  inmost  membrane,  like  which  it  may  be  a  mere 
transformation  of  the  outer  substance  of  the  yolk ;  or  is  it  not  rather 
a  product  of  the  granulosa,  since  it  takes  no  share  in  the  act  of 
cleavage?  The  chorion  is  separated  from  the  inner  capsule  by  a 
liquid  in  which  the  egg  moves  freely,  touching  the  capsule  by  its 
lowest  part.  Frequently  the  egg  of  Triton,  still  within  the  oviduct, 
has  its  vitelline  sphere  of  an  elliptic  figure  (persisting  after  extrac- 
tion), the  space  about  the  chorion  being  at  this  time  filled  with  jelly. 
In  Triton  the  liquid  is  often  bistre-coloured  and  the  inner  capsule  is 
much  thinner  than  in  Axolotl,  where  its  optic  section  displays  a 
fibrous  aspect.  The  liquid  of  Axolotl  at  first  contains  brilliant 
granules  and  little  opaque  clots  which  subsequently  disappear.  The 
outer  capsule  is  transparent  as  glass,  elastic,  very  resistant,  bluish 
when  seen  against  a  dark  ground,  and  homogeneous  or  but  feebly 
striated  parallel  to  its  surface  ;  elliptic  in  Triton,  it  is  spherical  in 
Axolotl.  Like  the  inner  capsule  it  is  rapidly  deposited  in  the  first 
moiety  of  the  oviduct.  Here  begins  also  the  formation  of  the  adhe- 
sive layer,  to  be  completed  in  the  further  portion  of  the  duct.  In 
Triton  this  layer  is  thin,  easily  detached  from  the  outer  capsule  ;  not 
so  in  Axolotl,  where  it  is  much  softer,  swelling  by  contact  with 
water  and  resembling  a  viscous  mass.  Minute  depressions,  arranged 
with  tolerable  regularity,  are  often  seen  to  mark  a  part  of  the  thick- 
ness of  the  adhesive  layer.  These  are  probably  the  stigmata  left 
by  diatoms,  Avhich  in  other  places  occupy  spots  of  corresponding 
diameter. 

I.  2.  Professor  Van  Bambeke  distinguishes  seventeen  stages 
between  fecundation  and  the  exit  of  the  embryo  from  the  egg. 
Stage  I.,  ending  with  the  beginning  of  cleavage,  he  has  treated  in  a 
previous  memoir.  Stage  II.,  from  cleavage  to  the  commencement  of 
epiboly,  is  discussed  in  the  second  Part  of  this  essay.  Stages  III.- 
XVII.  are  here  duly  described. 

II.  The  author  has  studied  cleavage  of  the  egg  in  three  species  of 
Triton  {alpestris,  punctatus,  and  palmipes),  in  Axolotl,  Pelobates 
fuscus,  and  the  common  toad.  The  latter  is  here  referred  to  but 
cursorily,  for  its  strongly  pigmented  eggs  offer  peculiarities  to  be 
explained  in  a  future  memoir.  Six  stages,  ending  with  the  formation 
of  the  morula,  are  fully  described  and  illustrated.  An  historical 
sketch  is  added  in  which  the  results  detailed  are  compared  with 
those  of  Goette,  Biitschli,  O.  Hertwig,  Scott  and  Osborn,  and 
Benecke :  the  researches  of  Salensky  on  the  sterlet,  with  the  more 
general  views  of  Flemming,  Fol,  and  Mayzel,  are  also  noticed.  The 
whole  demands  an  attentive  study.  We  give  the  author's  own 
"  conclusions." 

1.  Cleavage  is  set  up  by  the  first  embryonic  nucleus  (der  erste 
Lehenskeim,  Goette),  placed  in  the  upper  hemisphere,  at  the  limit  of 
the  ccto-  and  endodermic  segments.  The  axis  of  the  egg,  which 
originally  passed  through  the  centre  of  the  germinal  depression,  now 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  589 

traverses  the  embryonic  nucleus  and  abuts  peripherally  at  a  point 
where  the  first  meridional  groove  will  appear ;  in  other  words,  the 
upper  or  active  pole  is  disi:)laced. 

2.  The  nucleus  undergoes  transfoimations  comparable  to  those 
observed  in  the  egg  of  most  organisms  (cleavage-amphiaster ).  There 
are  three  principal  phases,  to  the  last  only  of  which  the  descriptions 
and  figures  of  Goette  apply  ;  so  that  the  egg-nucleus  of  Amphibians 
makes  no  exception  to  the  general  rule. 

3.  As  Goette  has  shown,  a  clear  rim,  which  I  call  cleavage  plate, 
precedes  the  appearance  of  the  peripheric  groove.  It  is  most  clearly 
indicated  in  the  plane  of  the  future  equatorial  cleavage,  thus  esta- 
blishing a  marked  separation  between  the  ectodermic  spherules  and 
the  endodermic  mass.  It  has  manifestly  for  its  seat  the  line  of 
separation  between  what  I  term  the  ectodermic  and  endodermic  ex- 
tremities of  the  egg. 

4.  The  meridional  grooves  arise  as  pale,  strongly  marked  gutters 
along  the  pigmentary  cap  of  the  upper  hemisphere ;  afterwards,  by 
effacement  of  the  cleavage-spherules,  the  gutter  becomes  a  simple 
groove.  The  i:)igmentary  line  of  separation  then  belongs,  at  least  for 
the  most  part,  to  the  cortical  layer. 

5.  In  the  endodermic  extremity,  the  meridional  divisions  increase 
in  activity  from  the  centre  towards  the  periphery.  Accordingly,  at 
any  given  moment,  the  cleft  portion  covers  a  still  undivided  region, 
represented  in  sections  by  an  ellipse  whose  base  corresponds  to  the 
lower  pole  of  the  egg. 

6.  Certain  phenomena,  such  as  the  impulsion  of  cortical  pigmen- 
tary masses  towards  the  interior  of  the  egg,  the  irregularities  in  the 
planes  of  division  observable  in  some  phases,  &c.,  arc  explicable  only 
by  admitting  the  existence  of  contractions  of  the  protoplasm  of  the 
egg  dui'ing  cleavage. 

7.  The  roof  of  the  segmentation-cavity,  at  first  monoderic,  be- 
comes polyderic.  There  is  here  no  diiierence  between  the  eggs  of 
Anoura  and  Urodela. 

Vital  Properties  of  Cells.* — M.  Eanvier  directs  particular  atten- 
tion to  the  appearance  of  nuclei  in  dead  cells ;  taking  for  example 
the  lympliatic  and  "  fixed  "  cells  of  the  cornea,  he  points  out  that, 
during  life,  no  nuclei  can  be  made  out  in  them,  but  that  these  appear 
after  the  death  of  the  cells.  The  reason  of  this  appears  to  bo  that, 
during  life,  the  nuclei  are  not  apparent  because  their  refractive 
power  is  very  much  the  same  as  that  of  the  surrounding  protoplasm. 
At  death,  changes  take  place  in  the  protoplasm,  so  that  they  then 
become  apparent.  In  illustration  of  this  ho  has  performed  the 
following  experiments  : — - 

(1)  Two  corneae  were  carefully  removed  from  a  frog,  and  were 
both  placed  in  damp  chambers,  exactly  similar  in  construction  ;  one, 
in  a  room  of  23^,  was  submitted  for  ten  seconds  to  the  action  of  an 
electric  current ;  this  was  sufficient  to  kill  some  of  the  cells,  and  their 
nuclei   became   apparent   two   minutes   afterwards.     The  other  was 

♦  '  Comptos  Rori'liiH.'  Ixxxix.  (187^)  p.  .S18. 


590  RECORD   OF   CURRENT   RESEARCHES  RELATING   TO 

submitted  to  the  same  current,  at  a  temperature  of  2° ;  45  minutes 
elapsed  before  the  nuclei  became  apparent. 

(2)  Somewhat  similar  experiments  were  undertaken  with  eyes 
from  a  frog,  which  were  respectively  submitted  to  a  temperature  of 
33°  and  80°,  together  with  an  electric  current ;  in  the  former  the 
nuclei  appeared  within  an  hour  after  the  experiment ;  in  the  latter 
not  at  all. 

(3)  The  cornea  of  a  frog  was  submitted  to  an  induction  current 
sufficiently  strong  to  kill  the  cells,  and  was  then  kept  for  two  hours 
in  a  damp  chamber  at  a  temperature  of  33°  ;  it  was  then  found  that  the 
nuclei  were  broken  up  into  fragments  or  small  spherical  granules.  The 
action  in  this  case  appears  to  have  been  that  the  currents  broke  up  the 
nuclei,  and  the  work  thus  commenced  was  completed  by  "autodigestion." 

Coalescence  of  Amoeboid  Cells  into  Plasmodia.*— The  coagulation 
of  the  perivisceral  fluids  or  the  blood  of  Invertebrata  as  studied  in 
the  air-tight  chamber  presents,  as  Mr.  Geddes  shows,  some  significant 
phenomena.  Thus  the  amoeboid  corpuscles  of  the  earthworm's 
perivisceral  fluid,  those  of  the  gill  of  Pholas,  the  corpuscles  of 
Patella  and  Buccinum,  during  coagulation  become  aggregated  into 
groups,  which  rapidly  become  individualized,  and  themselves  send 
out  pseudopodia. 

Of  the  two  kinds  of  corpuscles  possessed  by  Pagurus,  the 
elongated,  coarsely  granular  ones  do  not  possess  this  power,  which 
however  belongs  to  the  finely  granular  ones,  which  may  enclose  the 
former  kind  in  their  clot ;  the  same  distinction  is  observed  in  Carcinus 
mcenas  and  Cancer  pagiirus.  The  corpuscles,  with  their  looped 
pseudopodia,  of  the  common  starfish  send  out  pseudopodia,  as  in  the 
previous  cases,  from  a  united  mass.  The  Echinoidea,  as  exemjilified 
by  Echinus  sph(era,  show  the  phenomenon  most  strikingly.  The  clear 
perivisceral  fluid  contains  coarsely  and  finely  granular  corpuscles 
similar  to  those  of  Paguriis,  besides  coloured  ones.  The  clot  com- 
mences as  a  cloudiness  of  the  liquid ;  the  cloud  gradually  becomes 
denser  until  a  small  brown  pellet  is  the  result.  This  is  formed 
entirely  of  the  finely  granular  corpuscles  which  run  first  into  small 
heaps,  these  uniting  into  larger  ones  until  a  large  mass  is  formed 
containing  the  nuclei  and  granules  in  an  endoplasm,  and  sending 
out  generally  filamentous  pseudopodia  from  a  hyaline  ectoplasm 
which  is  clearly  differentiated  from  the  former ;  the  pseudopodia 
sometimes  lengthen  to  an  immense  extent. 

A  comparison  of  these  cell-formed  clots  with  those  of  the  Myxo- 
mycetes  appears  to  demonstrate  a  true  homology  between  them ;  and 
the  possession  of  the  same  power  by  the  Ehizopods,  Microgromia, 
Bhaphidiophrys,  PJionergafes,  &c.,  shows  it  to  be  at  any  rate  a  very 
widely  spread  function  of  amoeboid  cells. 

Structure  and  Development  of  Dentine. t — M.  Magitot  gives  a 
short  account  of  his  investigations  on  this  structure,  which  have  led 
him  to  the  conclusion  that  it  is  not,  as  some  writers— Duvernoy  e.  g. — 

*  'Proc.  Roy.  Soc.,'  xxx.  (1880)  p.  252,  and  1  plate, 
t  '  Couiptes  Rcndus,'  xo.  (1880)  p.  1298. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  591 

have  imagined,  a  secreted  product,  but  that  it  is  a  living  tissue ;  this 
view,  however,  is  now  old,  and  appears  to  owe  its  origin  to  Professor 
Owen,  who*  pointed  out  the  striking  similarity  which  obtains 
between  dentinal  and  ordinary  osseous  tissue. 

Ovary  of  Mammals. t — Dr.  Jules  Macleod  (of  the  Ghent  Histo- 
logical Laboratory)  describes  the  ovaries  of  the  bat  (pipistrelle), 
mole,  and  stoat.  Successful  results  were  obtained  by  the  method  of 
double  coloration.  The  ovary  and  oviduct  are  very  closely  connected 
by  means  of  their  serous  investment,  as  in  other  mammals  except 
man.  The  parenchymatous  zone  of  the  stroma  is  not  resolvable  into 
the  separate  layers  (cortical,  subcortical,  and  follicular),  distin- 
guished by  His.  In  the  stoat  this  zone,  with  its  peripheric  lobules, 
is  copiously  developed  and  sharply  limits  the  included  medullary 
vascular  stroma  ;  while  in  the  mole  and  bat  these  two  portions  of  the 
stroma  lie  side  by  side,  the  one  not  being  wrapped  round  the  other. 
In  the  bat  their  structure  is  nearly  identical.  The  ovary  of  the 
adult  mole  offers  seasonal  diflferences  as  to  size,  structure,  and  orien- 
tation, which  are  not  constant,  and  merit  further  study.  The  serous 
endothelium  of  the  bat  passes  gradually  into  the  adjoining  ovarian 
epithelium.  The  cuboid  epithelium  of  the  mole  is  very  distinct  from 
the  endothelium  of  the  serous  layer,  which,  as  in  the  bat,  is  excep- 
tionally extended  over  most  of  the  ovary.  In  the  stoat  the  epithelium 
is  nearly  cyliudric.  The  adult  intertrabecular  ovarian  stroma  of 
these  three  mammals  is  largely  made  up  of  elements  comparable  to 
the  Plasmazellcn  of  Waldeyer,  whose  interpretation  of  the  Graafian  • 
follicles  also  coincides  with  the  description  of  their  structure  and 
development  here  given.  Finally,  the  ovary  contains  medullary 
cords,  v/hich  the  author,  following  Balfour,  regards  as  homologues  of 
the  male  seminiferous  tubules.  These  cords  are  especially  abundant 
in  the  mole,  less  so  in  the  bat ;  in  both  the  contiguous  ovarian  surface 
is  closely  invested  by  its  capsule,  as  is  the  testicle  by  its  albuginea. 

Influence  of  Saline  Solutions  on  Protoplasm.  | — The  researches 
of  M.  Costerus  were  stimulated  by  the  results  obtained  by  Professor 
de  Vries  in  examining  the  influence  of  acids  on  vegetable  substances. 
The  solutions  employed  by  the  former  contained  chiefly  chloride  of 
sodium  or  nitrate  of  potash,  and  the  object  of  examination  was  most 
frcc^ucntly  the  red  beet-root. 

The  following  was  his  method  of  investigation : — In  glass 
capsules,  about  3  cm.  high,  he  placed  some  very  thin  slices  of  beet- 
root, which  were  covered  over  by  water ;  similar  slices  were  immersed 
in  a  10  per  cent,  solution  of  sea-salt.  It  resulted  from  those  experi- 
ments that,  at  the  end  of  a  few  days,  the  slices  in  the  salt-solution 
comj)lctely  lost  their  colour,  whereas  thf)so  in  pure  water  for  some 
considerable  time  after,  retained  their  colour.  Similar  results  were 
obtained  with  solutions  of  nitrate  of  potassium. 

To  what  was  this  efl'oct  due ;  is  more  oxygen  absorbed  by  water 

*  '  ComptcH  RpikIuh,'  ix.  p.  784. 

t  '  Aroli.  (Ic  liiolo^'io,"  i.  (1880)  pp.  241-278  (2  platfs). 

X  '  Arch.  NeiTl.  Sci.  o.\nct.  ( t  iiat.,'  xv.  (1880)  p.  148. 


592  KECORD    OF    CUERENT    RESEARCHES    RELATING    TO 

when  the  salts  are  absent  from  it?  To  resolve  this  question  the 
author,  instead  of  using  thin  slices,  experimented  on  pieces  1-2  and 
5  mm.  in  thickness,  and  5  mm.  in  length  and  width.  The  access  of 
air  beincf  thus  hindered,  it  was,  obviously,  possible  to  see  whether  the 
already  observed  diiferences  were  altogether  to  be  ascribed  to  the 
greater  difficulty  of  respiration  in  salt-solution  ;  and  these  observa- 
tions led  him  to  the  conclusion  that,  when  less  air  penetrates,  the 
diiFerence  between  cells  in  pure  water  and  in  salt-solution  is  less 
distinctly  marked.  The  next  thing  was  to  subject  the  slices  of  beet- 
root to  an  air-pump,  before  commencing  the  investigation  ;  pieces 
thus  treated  showed  a  remarkable  result,  inasmuch  as  the  balance  was 
after  fifteen  days  in  favour  of  the  pieces  immersed  in  the  salt- 
solution. 

Other  results  confirm  a  conclusion  which  may  be  thus  formulated ; 
the  cells  of  the  red  beet-root,  when  air  has  free  access  to  them,  are 
injm-iously  aftected  by  salt-solutions,  while  when  the  air  is  removed 
or  is  only  present  in  small  quantities  these  solutions  have  a  sustaining 
effect.  The  former  point  is  the  only  one  which  the  author  at  present 
attempts  to  explain,  and  this  explanation  is  found  in  the  fact  that 
saline  solutions  absorb  less  gas  than  pure  water,  and  that  the  co- 
efficient of  absorption  decreases  in  proportion  as  the  solutions  become 
more  concentrated. 

"Law  of  Association."  * — M.  Edmond  Perrier  considers  that  the 
oft-repeated  objections  to  the  theory  of  evolution  leave  the  funda- 
mental principles  of  that  doctrine  untouched.  Having  gone  over  the 
various  organisms  from  lowest  to  highest,  seeking  out,  not  the 
differences,  but  the  points  of  similarity  between  them,  he  believes  he 
has  ascertained  that  a  simple  and  very  general  law  presided  over  their 
formation,  that  they  were  derived  from  one  another  by  a  constant 
process,  and  that  he  has  succeeded  in  adding  a  few  arguments  to  the 
theory  of  the  genealogical  relationship  of  species. 

This  law  M.  Perrier  terms  the  "  law  of  association."  The  process 
by  which  it  has  produced  the  majority  of  organisms  is  the  "  transfor- 
mation of  societies  into  individuals." 

Ever  since  it  was  shown  that  every  living  being  was  composed  of 
microscopic  corpuscles  more  or  less  resembling  one  another — that 
similar  corpuscles  capable  of  leading  an  independent  existence  consti-  ~ 
tuted  of  themselves  the  simplest  organisms — it  has  been  thought  that 
the  most  highly  organized  animals  and  plants  were  comparable  to 
vast  associations  of  distinct  individuals,  each  represented  by  one  of 
these  living  corpuscles  or  cells.  In  the  same  organism  the  life  of 
each  cell  is  so  independent  of  that  of  its  neighbours,  that  it  is  possible 
to  destroy  one  set  of  cells  without  affecting  the  others.  Despite  the 
common  bond  which  unites  them,  these  cells,  sometimes  very  dis- 
similar, retain  their  individuality  and  perform  their  different  functions 
for  the  wellbeing  of  the  whole  community,  like  the  various  members 
of  a  populous  town. 

By  "  association,"  however,  is  not  meant  that  the  individuals  band 

*  '  Revue  Scientifique,'  Dec.  1«79,  p.  .'iSR.    Soo  '  Pop.  Sci.  Rov.,'  iv.  (1 SSO)  p.  .SO. 


INVERTEBRATA,    CRYPTOGAMIA,   MICROSCOPY,   ETC.  593 

together  like  bees  or  other  gregarious  creatures ;  and  to  illustrate  this 
law  it  is  necessary  to  refer  to  forms  lower  down  in  the  scale  in  which 
the  component  individuals  are  united  to  each  other  by  a  common 
tissue.  Accordingly,  M.  Perrier  turns  first  to  the  Hydroids,  and, 
after  referring  to  the  budding  of  the  Hydrce,  shows  that  in  compound 
forms  such  as  Cordylophora  lacustris,  and  in  most  of  the  marine 
Hydroids,  what  is  only  occasionally  produced  in  Hydra  becomes  normal. 
But  a  new  phenomenon  occurs — a  veritable  system  of  division  of 
labour  is  effected  between  the  members  of  the  same  colony.  At 
first  all  were  similar,  all  performed  the  same  functions  in  the  same 
manner,  but  speedily  each  individual  became  specialized.  One  devotes 
itself  exclusively  to  the  capture  of  food,  another  to  the  elaborating  of 
the  nutritive  material,  and  a  third  to  reproduction,  so  that  in  the  end  all 
these  individuals,  which  originally  had  no  need  of  one  another,  become 
mutually  necessary.  Among  the  Hydractiniae  we  may  reckon  no  fewer 
than  seven  kinds  of  individuals  fulfilling  different  functions.  It  might 
seem  to  be  an  exaggeration  to  attribute  the  quality  of  individuals  to 
the  different  parts.  We  have  here,  it  might  be  said,  simple  organs  ; 
but  organs  of  what  ?  They  are  just  as  independent  of  each  other  and 
of  the  nutritive  individuals  as  the  latter  can  be  of  one  another.  Hence 
they  are  not  organs  of  those  polyps.  Are  we  to  see  in  them  organs 
of  the  colony  ?  This  is  at  once  to  recognize  that  the  colony  has  an 
individual  character,  and  consequently  to  assume  the  transformation 
we  seem  to  demonstrate.  But  how  has  a  colony  been  able  to  acquire 
such  organs  ?  Whence  can  they  have  arisen  if  not  from  a  transforma- 
tion of  the  individuals  composing  it  ? 

The  author  considers  that  there  is  no  occasion  for  hypothesis  in 
order  to  demonstrate  that  these  colonial  organs  are  the  equivalents  of 
true  individuals.  The  buds  which  give  origin  to  the  different  kinds 
of  individuals  in  a  colony  of  Hydractinifc,  all  originate  in  the  same 
way,  and  are  for  a  long  time  so  similar  that  there  is  nothing  to  enable 
them  to  be  distinguished.  In  Podocoryne  the  humble  sac  which 
represents  the  sexual  individual  is  replaced  by  a  Medusa  much  higher 
in  organization  than  the  Hydra  itself,  which  detaches  itself  on  its 
arrival  at  maturity. 

The  same  train  of  reasoning  is  applicable  to  the  Siphonophora 
and  also  to  the  Coralliaria,  which  are  more  highly  organized  and 
exhibit  a  more  complete  amalgamation  of  the  component  individuals, 
each  of  which  in  the  Coralliarian  polyp  may  be  considered  as  a 
number  of  Hydroid  polyps  rolled  into  one. 

This  transforming  of  a  number  of  individuals  into  one  individual 
can  likewise  be  traced  out  in  the  Worms.  Van  Bencdcn  established 
that  each  of  the  joints  of  a  tape-worm  is  the  equivalent  of  a  Trematode; 
and,  at  a  yet  earlier  period,  naturalists  considered  the  segments  of 
wonns  and  insects  to  be  equivalent  units,  each  having  an  actual 
individuality,  which  they  called  zoonitcs.  Sea-urchins  and  star-fishes 
have  also  been  looked  upon  as  colonics  of  worms  united  by  their 
heads. 

Can  we  say  the  same  of  the  Mollusca  and  Vertebrata,  all  the  parts 
of  which  seem   to  be  so  intimately  fascd  together?     This  is  what 

VOL.  III.  2  R 


694  BECORD   OF   CURRENT   RESEARCHES  RELATING   TO 

lias  still  to  be  investigated  ;  but  whatever  the  result  arrived  at,  the 
generality  of  the  principle  of  association  will  not  be  at  all  invalidated, 
for  if  in  this  case  simple  individualities  never  existed,  we  should  have 
to  compare  the  Mollusca  and  the  Vertebrata  with  the  primordial 
individuals,  the  combinations  of  which  produced  the  other  types.  How 
did  these  individuals  themselves  originate  ? 

The  Hydrce  and  other  analogous  organisms,  the  author  thinks, 
furnish  the  answer ;  and  after  dealing  with  these,  he  says : — 

"  Thus,  even  if  it  be  shown  that  the  Vertebrata  and  Mollusca  do 
not  result  from  the  fusion  of  simpler  beings  once  capable  of  an  inde- 
pendent existence,  they  will  not,  any  the  less,  be  colonies  of  cells. 
The  '  law  of  association '  will  consequently  lose  none  of  its  generality, 
and  will  remain  the  fundamental  law  of  the  development  of  the 
animal  kingdom,  including  and  governing  those  laivs  of  grotdli,  organic 
repetition,  and  economy,  that  for  a  long  time  past  have  engaged  the 
attention  of  physiologists,"  while  it  explains  hitherto  inexplicable 
homologies. 

The  author  then  passes  to  the  consideration  of  protoplasm,  and 
from  the  incapacity  of  the  protoplasmic  masses  to  exceed  a  certain 
size,  draws  the  conclusion  that  all  creatures  that  exceed  this  size 
must  be  formed  of  several  distinct  masses  of  protoplasm — that  is,  are 
colonies.  "  Thus  the  generality  of  the  law  of  association  is  shown  to 
be  a  consequence  of  one  of  the  fundamental  properties  of  protoplasm." 

Degeneration.* — Professor  E.  Eay  Lankester  has  published,  as  a 
separate  volume,  the  lecture  which  he  delivered  on  this  subject  at  the 
British  Association  meeting  in  1879. 

In  attempting  to  reconstruct  the  pedigree  of  the  animal  kingdom, 
and  so  to  exhibit  correctly  the  genetic  relationships  of  all  existing 
forms  of  animals,  naturalists  have  hitherto  assumed  that  the  process  of 
natural  selection  and  survival  of  the  fittest  has  invariably  acted  so  as 
either  to  improve  and  elaborate  the  structure  of  all  the  organisms  sub- 
ject to  it,  or  else  has  left  them  unchanged,  exactly  fitted  to  their  condi- 
tions, maintained,  as  it  were,  in  a  state  of  balance.  It  has  been  held 
that  there  have  been  some  six  or  seven  great  lines  of  descent — main 
branches  of  the  pedigree — such  as  those  of  the  vertebrates,  molluscs, 
insects,  star-fishes,  and  so  on ;  and  that  along  each  of  these  lines  there 
has  been  always  and  continuously  a  progress — a  change  in  the 
direction  of  greater  elaboration. 

Each  of  these  great  branches  of  the  family  tree  is  held  to  be 
independent.  They  all  branch  ofi"  nearly  simultaneously  from  the 
main  trunk.  The  animal  forms  constituting  the  series  in  each  of 
these  branches  are  supposed  to  gradually  increase  in  elaboration  of 
structure  as  we  pass  upwards  from  the  main  trunk  of  origin  and  climb 
further  and  fui-ther  towards  the  youngest,  most  recent  twigs.  New 
organs  have,  it  is  supposed,  been  gradually  developed  in  each  series, 
giving  their  possessors  great  power,  enabling  them  to  cope  more 
successfully  with  others  in  that  struggle  for  existence  in  virtue  of 

*  '  Degeneration  :  a  chapter  in  Darwinism.' .  (8vo,  London,  1880.) 


INVERTEBRATA,   CRYPTOGAMIAj   MICROSCOPY,    ETC.  595 

•wHch  these  new  organs  have  been  little  by  little  called  into  being. 
At  the  same  time,  here  and  tliere  along  the  line  of  march,  certain 
forms  have  been  supposed  to  have  "  fallen  out " — to  have  ceased  to 
improve ;  and  being  happily  fitted  to  the  conditions  of  life  in  which 
they  were  long  ago  existing,  have  continued  down  to  the  present  day 
to  exist  in  the  same  low,  imperfect  condition.  It  is  in  this  way  that 
the  lowest  forms  of  animal  life  at  present  existing  are  usually  explained, 
such  as  the  microscopic  animalcules,  Amoehi^  and  Infusoria.  It  is  in 
this  way  that  the  lower  or  more  simply-made  families  of  higher 
groups  have  been  generally  regarded.  The  simpler  living  Mollusca 
have  been  supposed  necessarily  to  represent  the  original  forms  of  the 
great  race  of  Mollusca.  The  simpler  vertebrates  have  been  supposed 
necessarily  to  represent  the  original  vertebrates,  and  so  on. 

That  this  is,  to  a  certain  extent,  a  true  exjilanation  of  the  existence 
at  the  present  day  of  low  forms  of  animals  is  proved  by  the  fact  that 
we  find,  in  very  ancient  strata,  fossil  remains  of  animals  whicli  difter 
over  so  little  from  particular  animals  existing  at  the  present  day; 
for  instance,  the  Brachiopods  Lingula  and  Terehraiula,  the  king- 
crabs,  and  the  pearly  nautilus  are  found  living  at  the  present  day, 
and  arc  also  found  with  no  appreciable  difference  in  very  ancient 
strata  of  the  earth's  crust,  deposited  so  long  ago  that  most  of  the 
present  forms  of  life  had  not  then  been  brought  into  existence,  wliilst 
other  most  strange  and  varied  forms  occupied  their  place,  and  have 
now  for  long  ages  been  extinct. 

Whilst  we  are  thus  justified  by  the  direct  testimony  of  fossil 
remains  in  accounting  for  some  living  forms  on  the  hypothesis  that 
their  peculiar  conditions  of  life  have  been  such  as  to  maintain  them 
for  an  immense  period  of  time  in  statu  quo  unchanged,  loe  have  no 
reason  for  applying  this  hypothesis,  and  this  only,  to  the  explanation  of 
all  the  more  imperfectly  organized  forms  of  animal  or  plant  life. 

It  is  clearly  enough  possible  for  a  set  of  forces  such  as  we  sum  up 
-  under  the  head  "  natural  selection  "  to  so  act  on  tlie  structure  of  an 
organism  as  to  produce  one  of  three  results,  namely  these :  to  keep  it 
in  statu  quo  ;  to  increase  the  complexity  of  its  structure  ;  or  lastly,  to 
diminish  the  comiilexity  of  its  structure.  We  have  as  possibilities 
either  halance,  or  elaboration,  or  degeneration. 

Owing,  as  it  seems,  to  the  predisposing  influence  of  the  systems 
of  classification  in  ascending  series  proceeding  steadily  upwards  from 
the  "  lower  "  or  simplest  forms  to  the  "  higher  "  or  more  complex  form 
— systems  which  were  prevalent  before  the  doctrine  of  transformisni 
had  taken  firm  root  in  the  minds  of  naturalists — there  has  been  up  to 
the  present  day  an  endeavour  to  explain  every  existing  form  of  life  on 
the  hypothesis  that  it  has  been  maintained  for  long  ages  in  n  state  of 
balance  ;  or  else  on  the  hypothesis  that  it  has  been  elaborated  and  is 
in  advance,  an  improvement  upon  its  ancestors.  Only  one  naturalist 
—  Dr.  Dijhrn,  of  Naples— has  put  forward  *  the  hypothesis  of  dege- 
neration as  capable  of  wide  ajiijlication  to  the  explanation  of  existing 
forms  of  life  ;  and  his  arguments  in  favour  of  a  general  application 

*  '  Der  Ursprung  dor  WirlxUliion'  mid  das  Princip  <U>8  Fmiclions-wjclisolH.' 
(Lcip/iR,  187r).) 

2   11   2 


596  RECORD  OF   CURRENT   RESEARCHES   RELATING   TO 

of  this  hypothesis  have  not,  Professor  Lankestcr  thinks,  met  with  tho 
consideration  which  they  merit. 

Naturalists  have  long  recognized  what  is  called  retrogressive  meta- 
mori^liosis  in  the  case  of  parasitic  animals,  and  it  is  the  more  i-emark- 
able  that  the  same  hypothesis  should  not  have  been  applied  to  the 
explanation  of  other  simple  forms  of  animals.  The  hypothesi-s  of 
degeneration  will,  it  is  believed,  render  most  valuable  service  in 
pointing  out  the  true  relationships  of  animals  which  are  a  puzzle 
and  a  mystery  when  we  use  exclusively  the  hypothesis  of  Balance 
or  Elaboration. 

Eeferring  to  tho  lizard-like  creatures  Se/ps  and  Bipes,  which  have 
lost  the  locomotive  organs  once  possessed  by  their  ancestors,  it  is 
pointed  out  that  this  very  partial  or  local  atrophy  is  not  what  the 
author  means  by  Degeneration ;  but  if  this  atrophy  is  extended  to  a 
variety  of  important  organs,  we  shall  then  have  a  thorough-going 
instance  of  it. 

Degeneration  may  be  defined  as  a  gradual  change  of  the  structure 
in  which  the  organism  becomes  adapted  to  less  varied  and  less  complex 
conditions  of  life,  whilst  elaboration  is  a  gradual  change  of  structure 
in  which  the  organism  becomes  adapted  to  more  and  more  varied  and 
complex  conditions  of  existence.  In  elaboration  there  is  a  new 
expression  of  form,  corresponding  to  new  perfection  of  work  in  the 
animal  machine.  In  degeneration  there  is  suppression  of  form,  cor- 
responding to  the  cessation  of  work.  Elaboration  of  some  one  organ 
onay  be  a  necessary  accompaniment  of  degeneration  in  all  the  others. 
In  fact,  this  is  very  generally  the  case  ;  and  it  is  only  when  the  total 
result  of  the  elaboration  of  some  organs  and  the  degeneration  of  others 
is  such  as  to  leave  the  whole  animal  in  a  lower  condition — that  is, 
fitted  to  less  complex  action  and  reaction  in  regard  to  its  surround- 
ings than  was  the  ancestral  form  with  which  we  are  comparing  it 
(either  actually  or  in  imagination) — that  we  speak  of  that  animal  as 
an  instance  of  degeneration. 

Any  new  set  of  conditions  occurring  to  an  animal  which  render  its 
food  and  safety  very  easily  attained,  seem  to  lead  as  a  rule  to  degenera- 
tion ;  just  as  an  active,  healthy  man  sometimes  degenerates  when  he 
becomes  suddenly  possessed  of  a  fortune.  The  habit  of  parasitism 
clearly  acts  upon  animal  organization  in  this  way.  Let  the  parasitic 
life  once  be  secured,  and  away  go  legs,  jaws,  eyes,  and  ears.  The 
active,  highly-gifted  crab,  insect,  or  annelid  may  become  a  mere  sac, 
absorbing  nourishment  and  laying  eggs. 

Some  examples  of  undeniably  degenerate  animals  are  examined, 
amongst  which  are  Sacculina,  which  infests  hermit-crabs,  and  from  its 
young  (nauplius)  stage  with  legs,  has  become  a  mere  sac  filled  with 
eggs,  and  absorbing  nourishment  by  root-like  processes ;  Lernceocera, 
the  parasite  of  the  gills  of  fishes,  which  has  lost  the  well-developed 
legs  of  its  early  stage  and  become  a  worm-like  creature ;  the 
cirrhipedes  (barnacles),  the  mites,  and  the  ascidians. 

Special  attention  is  given  to  the  latter,  the  author's  object  being 
to  show  that  their  structure  and  life-history  may  be  best  explained  on 
.the  hypothesis  that  they  are  instances  of  degeneration,  and  in  fact  are 


INVERTEBRATA,   CRYPTOaAMIA,   MICROSOOPYj   ETC.  597 

degenerate  vertebrates,  as  the  barnacles  are  degenerate  crustaceans. 
The  identity  of  the  tadpole  of  the  ascidian  and  the  tadjjolc  of  the  frog 
is  illustrated  by  figures  representing  the  external  ai)poaranco  and  the 
chief  internal  organs,  together  with  others,  showing  how  the  degenera- 
tion proceeds  which  the  ascidian  tadpole  has  to  go  through  to  arrive 
at  the  adult  structure. 

The  chief  causes  of  structural  degradation  are  (1)  parasitism,  (2) 
fixity  or  immobility  (as  in  the  adult  bai'nacle  and  ascidian),  (3)  vege- 
tative nutrition  (as  in  the  green  Planarian  worms),  and  (4)  excessive 
reduction  in  size  (exemplified  in  the  Rotifers,  Ostracoda,  and  Polyzoa). 
Where  the  conditions  are  present  degeneration  may  be  suspected  even 
in  the  absence  of  any  confirmatory  embryological  evidence. 

Degenerative  evolution  is  not  limited  to  zoology,  but  is  applicable 
to  botany  as  w'cll,  as  it  clearly  offers  an  explanation  of  many  vegetable 
phenomena,  and  is  already  admitted  as  the  explanation  of  facts  con- 
nected with  the  reproductive  process  in  the  higher  plants.  The  yeast- 
plant  is  in  all  probability  a  degenerate  floating  form  derived  from  a 
species  of  Mucor. 

Animal  Development.* — Professor  Schafer,  in  his  lectures  on 
Animal  Development  delivered  at  the  Royal  Institution,  thus  formu- 
lates some  of  the  general  results  arrived  at  from  a  consideration  of 
the  facts  discussed : — 

(1)  If  we  compare  the  processes  of  development  of  any  two 
animals,  from  sponges  upwards,  we  find  complete  correspondence  up 
to  a  certain  point ;  from  which  point  they  may  diverge  from  one 
another.  This  point  is  sometimes  placed  near  the  bottom  of  the 
development-scale,  sometimes  near  the  top ;  or  it  may  be  in  any  inter- 
mediate position. 

(2)  Development  is  essentially  localization  of  function  and  con- 
comitant or  consequent  modification  of  structure ;  such  modification 
being  accompanied  by  segregation  of  the  cells  concerned  with  the 
function  localized. 

(3)  The  i)ath  of  development  of  all  the  more  important  of  these 
BCgi'cgated  parts  is  the  same  up  to  a  certain  point  in  the  development 
of  each  segregation.  From  this  point  it  may,  in  any  animals  or  group 
of  animals,  diverge  from  the  rest,  or  may  remain  stationaxy,  whilst  in 
the  others  specialization  and  modification  progress  further. 

(4)  The  various  stages  or  phases  of  development  of  an  animal,  as 
well  as  of  its  specialized  parts,  are  often  found  to  correspond  with 
cither  permanent  or  transient  conditions  of  animals  lower  in  tho 
scale. 

(5)  Since  the  phases  of  development  of  individual  animals  are  often 
seen  to  be  rejnesentations  of  the  permanent  conditions  which  are  met 
with  in  a  serius  of  animals  belonging  to  lower  grades  of  organization, 
it  is  impossible  not  to  infer  that  these  successive  phases  in  the  deve- 
lopment of  the  individual  represent  simihir  i)hases  in  the  process  of 
formation  or  development  of  the  race  to  which  tho  individual  belongs. 

*  'Qiiiirt.  Joiirn.  Mirr.  Si-i.,'  xx.  (ISiO)  [>.  202.  (Coiitiiiiiing  Ihc  bubstuiico  ol" 
the  luiil  two  of  the  twelve  Iccturei;.) 


598  RECOED   OP   CURRENT   RESEARCHES   RELATING   TO 

To  revert  to  a  former  simile,  we  may  safely  say  that  the  developmental 
telescope  of  the  individual  is  the  same  as  that  of  the  race,  but  with 
the  tubes  shortened  or  shifted  one  upon  another  so  that  in  many  cases 
their  original  order  is  no  longer  recognizable.  The  history  of  the 
development,  then,  of  any  individual  animal  from  the  egg  is  an 
abridgment  of  the  history  of  formation  in  time  of  the  race ;  or,  to 
state  the  matter  in  as  few  words  as  possible,  "  development  represents 
descent." 

We  conclude,  therefore,  that  the  ancestors  of  every  animal  have 
successively  exhibited  structural  conditions  which  are  rej)resented  in 
a  more  or  less  modified  form  by  the  successive  stages  of  development 
of  the  individual.  This  is  the  only  logical  conclusion  to  which  the 
study  of  animal  development  leads.  Modifying  slightly  the  words  of 
Darwin,  "  to  take  any  other  view  is  to  admit  that  the  structure  of 
animals  and  the  history  of  their  development  form  a  mere  suare  laid 
to  entrap  our  judgment." 

Colours  of  Animals.* — Dr.  Camerano,  in  a  brief  notice  of  a  larger 
work  to  be  published  hereafter,  divides  colours  into  internal  and 
external.  In  animals  the  latter  have  of  course  the  chief  importance, 
and  he  classifies  them  morphologically  as  Hypodermic  and  Epidermic, 
and  physiologically  as  (1)  Useful,  including  those  which  are  pro- 
tective (allowing  escape),  attractive  (to  the  prey  of  the  animal), 
deviatory,  as  the  eye-like  spots  of  some  insects,  which  distract 
attention  from  vital  parts;  (2)  Indifferent;  (3)  Budimental,  the 
remains  of  a  previous  more  extensive  coloration ;  (4)  Accidental,  as 
melanism  and  albinism,  arising  out  of  special  circumstances  peculiar 
to  the  individual, 

Passing  from  the  consideration  of  the  nature  of  some  colours,  he 
reviews  the  condition  of  the  different  gi'oups  of  the  animal  kingdom 
in  their  relation  to  colour,  taking  certain  species  from  each  as 
examples.  He  distinguishes  sexual  coloration  from  that  which 
depends  on  the  time  of  year,  &c. 

The  referees  on  the  paper  (Signers  Cornalia  and  De  Sanctis) 
believe  that  the  interpretations  of  the  meaning  of  the  intensity, 
quality,  or  position  of  a  colour  need  further  examination  in  many 
cases ;  for  though  one  type  of  coloration  running  through  several 
species  many  perhaps  be  exi^licable ;  yet  when  several  species  agree- 
ing in  other  respects — as  volume,  habitat,  food — are  foimd  to  differ  in 
the  matter  of  colour,  it  is  diiScult  to  account  for  the  fact  on  utilitarian 
principles. 

Organisms  in  Ice  from  Stagnant  "Water.f — Mr.  M.  A.  Veeder 
has  made  microscopical  investigations  with  regard  to  the  purity  of  ice 
gathered  from  stagnant  water  in  canals  and  ponds.  Only  those  frag- 
ments were  taken  (from  the  interior  of  blocks)  which  appeared  clean 
and  transparent  to  the  unassisted  eye.  On  melting  them  and 
examining  the  water  thus  obtained  with  various  powers  up  to 
900  diameters,  bits  of  vegetable  tissues  and  confervoid  growths  are 

*  '  Atti  R.  Acead.  Lincei  (Traubuut.),'  iv.  (1S60)  p.  loO. 
t  'Am.  Nat.,'  xiv.  (1880)  p.  388. 


rNVERTEBRATAj   CRYPTOGAMU,   MICROSCOPY,   ETC.  599 

usually  recognisable  at  once.  Animaloula  were  not  found  in  an 
active  state  in  water  from  ice  that  just  melted,  but  upon  allowing 
such  water  to  settle  and  become  warm  at  the  ordinary  temperature  of 
a  room  occupied  for  living  purposes,  the  sediment  deposited  is  found 
to  contain,  after  some  hours,  monads  whose  movements  are  easily 
discernible  with  a  magnifying  power  of  from  200  to  400  diameters. 
Upon  allowing  the  water  to  stand  still  longer,  Mr.  Veeder  found  the 
Confervae  growing  thriftily,  and  in  some  instances  forming  clusters 
or  bundles  frequented  by  minute  animalcula,  the  entire  ajipear- 
ance  in  this  case  being  very  similar  to  that  presented  by  the  nests 
occupied  by  the  young  of  the  common  Paramecium  seen  in  stagnant 
water. 

As  the  result  of  these  investigations,  it  appears  that  freezing  does 
not  free  water  from  filth  due  to  the  presence  of  sewage  or  decaying 
vegetable  matter,  and  further,  that  it  is  probable  that  the  germs  from 
which  animalcula  are  developed,  if  not  the  animalcula  themselves  in 
a  quiescent  state,  are  present  in  very  much  of  the  ice  fciken  from 
stagnant  water,  so  that  the  use  of  such  ice  in  drinking  water  is 
hazardous  to  say  the  least. 

B.  INVERTEBRATA. 

Fertilization  of  the  Ovum.* — Professor  Schneider  calls  attention 
to  his  observation  in  1873,  on  Mesostomum  and  Disfomum,  tliat 
the  nucleus  and  germinal  vesicle  become  elongated  and  break  up 
into  strands,  which  ultimately  become  arranged  into  a  rosette,  under- 
going further  changes.  The  grouping  of  the  granules  of  the  proto- 
plasm of  the  cell  into  a  star-shaped  form  was  described  in  1847, by 
Derbes  in  the  sea-urchin's  egg,  and  by  Eeichert  in  the  sj)erm-cells  of 
Nematodes,  &c.,  and  similar  facts  by  Kowalevsky  in  1866.  Biitschli's 
observations  on  the  "  directive  vesicles "  are  not  beyond  criticism. 
These  are  really  cells,  and  consist  of  part  of  the  germinal  vesicle 
with  some  protoplasm. 

Professor  Schneider's  own  recent  observations,!  carried  out  on 
Nematodes,  Hirudinea),  and  Asteracantldon  ruhens,  show  that  the  sperm- 
nucleus  has  no  existence.  lie  agrees  with  Fol  with  regard  to  Astera- 
cantldon in  the  main.  A  very  small  portion  of  the  germinal  vesicle 
is  extruded  with  the  directive  vesicle  ;  the  rest  sends  out  ameboid  pro- 
cesses in  all  directions,  wliicli  are,  however,  very  ditlicult  to  demon- 
strate. The  tliickncss  of  the  ovum  often  gives  very  misleading  views 
of  these  relations.  This  ditfusion  of  the  substance  of  the  nucleus  in 
the  ovum  renders  it  almost  impossible  for  tlio  entering  siKrniatozoou 
to  miss  it.  The  stellate  mass  described  as  surrounding  the  latter  at 
its  entrance  probably  belongs  to  the  germinal  vesicle,  attracted  by  tho 
stimulus  of  tho  male  clemenl.  At  the  cleavage  the  two  stellate  masses 
of  the  amjjJiiastcr  go  to  diflercnt  parts,  and  then  both  approach  tho 

♦  '  Zool.  Anzcig.,'  iii.  (1880)  p.  2r)2. 

t  He  observes  tliat  lie  liaa  loniul  acetate  of  cnruiino  (mudo  by  saturating 
boiling  acetic  acid  of  45  per  cent,  strength  with  carmine,  and  fiUoring)  very  iiscfnl. 
It  isuHed  either  diluted  to  a  1  per  cent,  solution  or  by  placin;,'  a  drop  of  the  ori^iu.d 
boluliou  uuilcr  the  cover-;^labd. 


600  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

cleavago-plane.  The  ovum,  contrary  to  Biitsclili  and  Hertwig,  is 
entered  by  the  siiermatozoon  wliile  still  in  the  ovarian  follicle,  not 
when  in  the  egg-capsule.  In  the  Nematodes  fecundation  takes  place 
in  the  oviduct.  In  Aster acantldon  ruhens  the  directive  vesicles 
emerge  from  the  micropylc.  At  the  ends  of  the  thirty  or  more  thin 
amoeboid  processes  of  the  germinal  vesicle  aj^pear  transitorily  stellate 
figures.  The  consequences  of  fertilization  may  be  carried  out  in  sea- 
water  in  immature  as  well  as  mature  eggs.  The  formation  of  embryos 
does  not  take  place  if  the  egg-membrane  has  not  been  sufficiently 
expanded  before  segmentation.  Healthy  embryos  may  be  produced 
from  ova  into  which  as  many  as  eight  spermatozoa  have  penetrated. 
The  spermatozoon  and  the  yolk-membrane  are  connected  by  a  fine 
process,  even  before  actual  contact  takes  place ;  this  appears  to 
originate  from  the  former.  After  the  entrance  of  the  spermatozoon  a 
ball  of  substance  appears  at  the  point  of  entrance  ;  it  originates  from 
the  yolk,  and  swells  up  to  a  round  bead,  larger  than  a  directive 
vesicle.  When  sj)ermatozoa  enter  immature  eggs,  this  swelling  has 
the  form  of  a  long  stripe,  whose  end  branches  out  stellately  :  no 
segmentation  takes  place  in  this  case. 

Aulostomum  and  Hirudo  require  several  years  for  the  genera- 
tive products  to  arrive  at  maturity ;  in  Nephelis  and  Clepsine  this 
occurs  in  the  spring  of  the  second  year.  In  them  all  the  sperm- 
cells  penetrate  to  the  ova  while  these  are  still  enclosed  in  their 
follicles  ;  in  Nephelis  a  ring  is  formed  by  them  in  the  middle  of  the 
mature  part  of  the  ovary.  In  Nephelis  they  may  enter  the  yolk  and 
continue  to  move  there  ;  they  also  penetrate  and  remain  under  the 
yolk-membrane,  but  are  absorbed  when  the  albumen  is  developed, 
as  also  in  Aulostomum,  where  eight  roll  about  with  a  screw-like 
motion  in  the  yolk.  In  Nephelis  the  germinal  vesicle  continues 
to  move  after  fertilization,  sending  out  two  or  three  stars.  The 
germinal  vesicle  is  visible  in  Aulostomum  when  the  ovum  leaves  the 
ovary ;  it  then  becomes  an  amphiaster,  which  is  concealed  by^dark 
granules. 

Renal  Organs  of  Invertebrata.* — In  the  course  of  an  interesting 
essay  on  this  subject,  Dr.  Krukenberg  gives  a  valuable  table  to  show 
the  character  of  the  renal  excretion,  and  the  organ  of  the  animal  in 
which  it  was  found  ;  other  columns  give  the  authority  and  biblio- 
graphical references.  We  can  here  only  cite  some  of  the  more 
interesting  of  these.  In  the  AdinicB  guanin  is  found  in  the  mesen- 
terial filaments  (Cams),  and  the  same  compound  is  in  Porpita  found 
in  a  whitish  layer  on  the  inferior  surface  of  the  mantle  (Kolliker). 
Selenka  found  no  uric  acid  in  the  "  Cuvierian  tubes  "  of  the  Holo- 
thuroida.  Bodies  closely  allied  to  xanthin  or  guanin  were  found  by 
Sommer  in  the  water-vascular  system  of  Tcenia.  Uric  acid  has  been 
detected  in  some  Tunicata.  The  organs  of  Bojanus  have  been 
frequently  seen  to  contain  urea  or  uric  acid.  In  some  Arthropoda 
similar  compounds  have  been  found  in  the  excreta  or  in  the  fatty 
bodies,  where  green  glands  and  Malpighian  vessels  are  absent. 

*  'Vergl.-Physiul.  Stutl.'  (Ki-ukenbcrg),  ii.  (ISSO)  p.  14. 


INVEBTEBRATA,   CRYPTOGAMIAj   MICROSCOPY,    ETC.  601 

MoUusca. 

Phylogeny  of  the  Dibranchiate  Cephalopoda.* — In  a  contribu- 
tion to  this  subject,  Dr.  Brock  points  out  how  little  has  been  done 
since  the  contributions  of  Professor  Owen,  now  some  forty  years  old, 
in  aid  of  our  knowledge  of  the  anatomy  of  the  group ;  embryologists 
have  done  their  best  to  unravel  some  of  the  problems  of  develoijment, 
and  it  is  now  necessary  to  make  some  attemj)t  at  their  comparative 
anatomy. 

Shell. — It  seems  to  be  quite  certain  that  the  Octopoda  arc  derived 
from  shell-bearing  forms  ;  Argonauta  has  in  the  young  the  rudiment 
of  a  shell-capsule,  and  Cirrhoteiithis,  which  is  no  true  Decapod,  has  an 
internal  shell. 

Musculature. — The  examination  of  this  system  is  attended  with 
very  considerable  difficulties ;  but  when  done  comparatively  it 
exhibits  some  interesting  relations,  as  the  following  table  will 
show  : — 

(1.)      I.  The  median  retractores  capitis  are  neither  fused  with  one 
another,  nor  with  the  lateral  muscles — Enoploteutlus. 
II.  The   median    retractors   begin   to   be    fused  with   one 
another — Onycliotcuthis. 
III.  Complete    fusion   of    the   median   retractors   with   one 
another,  and  partial  fusion  with  the  lateral  muscles — 
Ommastrcphes,  Sepioleuthis,  Loligo. 
IV.  Fusion  complete — Scpiola. 
V.  lietractors  enclosed  in  a  muscular  hepatic  capsule,  which 
is  widely  open  posteriorly — Sepia. 
VI.  The   capsule    completely   closed,    and    the   deprcssorcs 
infundibuli  attached  to  it — Octopoda. 
(2.)      I.  A  cephalo-cervical  articulation  developed  ;    the  collaris 
muscle  is  inserted  into  the  cervical  cartilage — CEgopsida 
(except  Loligopsis),  Sepiotcutkis,  Loligo,  Sepia. 
11.  Articulation  lost.      The  collaris  forms  a  closed  ring — 

Sepiola. 
III.  The   infundibular  articulation  rudimentary  or   absent ; 
the  external  layer  of  the  collaris  fused  with  the  dorsal 
portion  of  the  mantle — Octopoda. 
This  table  gives  evidence  of  a  jirogress  from  the  simjile  to  the 
more  complex,  and  of  the  relations  which  obtain  between  some  of  the 
Dibranchiata  and  Spirula  and  Nautilus  ;  the  latter  point  is  argued 
out  in  detail. 

With  regard  to  that  interesting  structure — the  valve  of  the  iu- 
fundibulum — the  author  points  out  that  it  is  clear  that  its  loss  is  au 
indication  of  the  attainment  of  a  liighcr  stage  ;  biit  he  urges  that  this 
loss  may  have  been  brought  about  iudcijcndeutly  in  the  Loligopsida 
and  in  the  Octopoda,  and  that  it  docs  not  therefore  have  any  weight 
in  fixing  their  respective  affinities. 

Tlie  central  nervous  system  of  the  Dibranchiata  appears  to  be 
eminently   formed   on   one   type ;    in    all   CT^gopsida    the   ganglion 

-  'Muri'Lul.  Jahibucb,'  vi.  (ISSO)  p.  ll>5. 


C02  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

bracbialo  lias  the  same  elongated  form,  as  was  signalized  by  Albany 
Hancock  in  Ommastrcplies  todarus ;  the  same  holds  good  for  the 
suiira-pharyngcal  lobe  of  all  the  Octopoda.  In  various  parts  of  the 
peripheral  system  stages  of  differentiation  can,  on  comparison,  be 
made  out ;  the  ganglion  stellatum,  for  example,  did  not  apparently 
belong  primarily  to  the  mantle,  but  lay  in  the  visceral  sac  whence 
it  sent  olf  nerves  to  the  mantle ;  this  arrangement  is  still  to  be  seen 
in  Loligopsis  guttata.  From  this  position  two  series  of  changes  may 
occur  :  the  nerve  and  its  ganglion  may  pass  to  the  mantle,  or  the 
pallial  nerve  may  separate  from  the  ganglion.  This,  seen  at  its 
earliest  in  most  of  the  CEgopsida,  is  carried  further  in  O.  todarus  and 
SepiotctUhis,  till  in  Loligo  it  is  carried  to  an  extreme.  Other  changes 
may  occur  in  various  other  forms,  and  in  the  short,  compressed  body 
of  the  Octopoda  i^art  of  the  pallial  nerve  is  very  considerably  reduced. 
The  commissure  between  the  brachial  nerves  was  found  to  be  simple 
in  all  the  Decapoda  that  were  examined  ;  in  Cirrhoteuthis  a  nervo 
descends  from  the  brachial  nerve  to  the  commissure,  while  in  the 
rest  of  the  Octopoda  the  primitive  commissure  forms  a  closed  ring,, 
connected  only  by  branches  with  the  nerves.  After  treating  of  the 
visceral  nerves,  different  stages  in  which  are  described,  the  author 
passes  to  the 

Excretory  System. — In  all  known  Decapod  Dibranchiata  there  arc 
two  symmetrically  disposed  orifices,  which  appear  to  be  primarily 
placed  in  the  angle  of  the  branchifc,  and  thence  to  jiass  more  or  less 
upwards,  and  inwards ;  in  the  Nautilus,  in  all  CEgopsida,  and  in 
SejjiotcutJiis  the  orifices  of  the  urinary  sacs  are  simple  and  slit-shaped  ; 
in  the  higher  Myopsida  and  in  the  Octopoda  more  or  less  elongated 
papilhc  are  there  developed  ;  and  these  papillae,  again,  exhibit  different 
stages. 

Passing  over  the  water-system  and  the  digestive  organs,  we  come 
to  the  ink-bag,  which  is  ontogcuctically  a  part  of  the  hind-gut. 
From  the  simple  embryonic  condition  two  series  of  differentiations 
can  be  made  out ;  one  jiasses  through  the  Decapoda  to  Sepia,  the 
other  through  the  Octopoda  to  Octopus  and  Eledune.  The  former  is 
principally  effected  by  changes  in  size,  without  any  chauge  from  the 
original  position.  Compared  with  Enoploteuthis  and  Sepioteuthis  it  is 
much  longer  in  Ommaslrephes,  Loligo,  and  OnychoteutJiis ;  others  have 
a  rudimentary  efferent  duct.  In  Chiroteuthis  Veranzi  it  is  triangular 
in  form ;  in  Sepiola  it  is  trilobate.  It  is  in  Sepia  only  that  this  ink- 
bag  becomes  connected  by  a  long  efferent  duct  with  the  anus.  In  the 
Octopoda  change  of  position  is  the  first  point  that  we  note ;  the  ink- 
bag  tends  to  pass  dorsally  behind  the  diaphragm,  and  to  enter  into 
closer  topographical  relations  with  the  liver.  In  Trcinoctopus  carence 
it  is  smaller,  and  the  duct  is  shorter  than  in  T.  violaceus.  The  heart 
of  the  Myopsida  appears  to  be  a  further  development  of  that  of  the 
CEgopsida,  while  the  still  more  highly  differentiated  organ  of  the 
Octopoda  is  evidently  related  to  that  of  the  Myopsida ;  no  certain 
comparison  can  be  made  with  Nautilus  or  Spirilla. 

Little  or  no  assistance  is  given  by  the  male  generative  organs 
to  the  resolution  of  phylogenetic  questions  ;  great  differences,  suffi- 


INVERTEBRATA,   CRYPTOGAMIA,    MICROSCOPY,   ETC. 


603 


cient  to  fill  more  than  a  page,  even  when  stated  in  a  tabular  form,  arc 
to  be  found  in  the  female  organs.  Dr.  Brock  sums  up  his  results  in 
the  following  fashion  : — 

(1)  All  typical  ffigopsida  possess  two  symmetrical  oviducts. 

(2)  The  same  is  true  of  all  typical  Octoijoda. 

(8)  The  forms  in  which  one  oviduct  is  wanting  (Myopsida)  arc  in 
all  points  the  most  ditterentiatcd  ;  so  that  it  follows  that  the  double 
oviduct  is  the  oldest  form  of  the  female  generative  apparatus,  and 
that  all  forms  with  one  only  have  lost  the  other  by  reduction  of  the 
l)arts. 

The  following  tables  will  exhibit  the  leading  diiicrcnccs  between 
some  of  the  most  important  genera  : — 


Nidamcntal  glands 

Oviducts     .. 

Kitdiila 

Anal  appondagcs 

Infnndibular  valve 

"8i)lcou"   .. 


Omniastrcplios. 


+ 
2 
Complicated 
Asymmetrical 
+ 
0 


Euoploteutliis. 


0 

2 

Simi)lc 

Symmetrical 

+ 

+ 


ChivotfuUiis. 

Lo 

igopsia. 

0 

0 

1 

? 

? 

? 

Symmetrical 

? 

0 

0 

+ 

? 

Owciiia. 


II. 


Shell 


ACCCSS017  hearts  .. 
Nidamcntal  glands 
Arms      


Oiuinastrcphcs 
sagittatus. 


Onycbotcuthis. 


Witli  phragmocoue  With  phragmocono 

Absent 

+ 

With  suckers 


Enoploteutbis. 


(Without  phragmo- 
t,  cone, 

brnnches  of  the 


(Developed  on  the 

\       cephulic  and  posterior  aorta). 

+  I  0 

/With  hooks  and\    ,,,..,   ,      ,         , 
1         «npl.-,.v.  h  ^Viih  hooks  onl 


suckers 


One  of  tlic  next  important  questions  is  the  meaning  of  the  shell  of 
Sepia  ;  in  other  points — musculature,  radula,  loss  of  superior  salivary 
glands,  forna  of  liver  and  of  ink-bag,  absence  of  connnissure  between 
the  ganglia  stellata  and  in  the  fusitm  of  the  accessory  nidamental 
glands — this  form  appears  to  be  one  of  the  most  dilierentiated  of  tho 
Decapoda.  Why,  then,  docs  it  retain  its  shell?  In  other  words, 
Has  Sepia  been  derived  from  Loligid  forms,  and  had  the  simple 
horny  shell  furtlier  developed  ? — or  (2)  Did  Sepia  separate  very 
early  from  the  Dibrancliiatc  stem,  and  get  its  various  other  characters 
ind(!i)endently  of  the  other  forms? — or  (3)  Is  Sepia  the  direct  de- 
scendant of  the  Belemnitcs,  and  have  the  oDshoots  each  independently 
lost  their  calcareous  shell  V  The  first  h3'pothesis  is  opposed  by 
jialicoiitidogy  ;  no  evidence  supports  the  second.  Tho  third  view  is 
the  m<ist  satisfactory,  inasniucli  as  it  seems  Ihc;  Decapoda  exhibit  a 
marked   tendency   to   lose  their  shell,  while   Spirula,   with  its  still 


604  EECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

older  slicll,  is  probably  an  example  of  a  form  whicli  did  early  separate 
itself  from  the  common  stock. 

The  next  point  discussed  is  one  of  considerable  difficulty ;  it  is 
the  relations  of  the  Octopoda  to  the  two  other  groups.  The  high  and 
exceedingly  peculiar  organization  of  the  Octopoda  seems  almost 
certainly  to  point  to  their  isolation  for  a  long  period  of  time,  or,  in 
other  words,  to  their  derivation  from  some  other  group  than  the 
Myopsida.  When  we  examine  the  Loligopsis-group  of  the  CEgopsida, 
we  find  that  they  alone  among  the  Decapoda  present  some  of  the 
peculiarities  of  the  Octopod  organization — the  absence,  namely,  of  a 
valve  to  the  funnel,  the  presence  of  a  well-developed  spleen,  and  the 
rudimentary  apparatus  for  closing  the  mantle.  As  we  may  suppose 
that  the  primitive  Dibranchiata  possessed  certain  arrangements,  such 
as  the  fusion  of  the  supra-pharyngeal  ganglion  with  the  cerebrum,  &c., 
which  are  now  only  seen  in  the  Nautilus  and  in  the  Octopoda — it 
seems  allowable  to  suppose  that  these  creatures  were  separated  into 
two  sets,  one  of  which  diverged  into  the  Ommastrephida,  and  the 
other  into  the  common  stem-form  of  the  Loligopsida  and  Octopoda. 
This  view  has  its  objections. 

To  sum  uj) :  it  seems  clear  that  the  Dibranchiate  Cephalopoda 
may  be  divided  into  three  distinct  phyla.  The  oldest  are  the 
CEgopsida ;  the  two  others — the  Myopsida  and  the  Octopoda — have  a 
closer  genealogical  relation  to  one  another.  The  Q^]gopsida  may  be 
divided  into  two  groups — the  Ommastrephida  and  the  Loligopsida. 
It  is  probable  that  the  (Egopsid  forms  passed  through  a  Belemnite 
stage  to  the  Sepias,  and  that  the  Decapoda  with  horny  shells  divei'ged 
as  independent  branches  at  different  times.  The  Octopoda,  or  most 
differentiated  forms,  have  evident  points  of  relationship  to  the  Loli- 
gopsida ;  this  derivation  may  not  have  been  altogether  simple. 

The  parallelism  in  mode  of  development  of  the  groups  is  very 
striking ;  it  is  best  shown  in  the  tendency  to  reduce  and  lose  the 
shell.  In  the  oldest  phylum  we  find  the  phragmocone,  or  a  simple 
horny  shell;  in  the  Myopsida  we  have  Sepiola  and  Bossia,  with  a 
shell  only  half  the  length  of  the  animal.  Cirrhoteuthis,  an  old 
Octopod,  has  a  distinct  internal  shell ;  but  in  the  more  developed 
forms,  not  only  is  the  shell  lost,  but  is  typically  so. 

The  long  essay  ends  with  a  discussion  on  the  general  bearing  of 
the  facts  detailed  on  the  doctrine  of  descent. 

Aptychi  of  Ammonites. — In  the  dwelling-chamber  of  Ammonites 
is  sometimes  found  a  remarkable  body — the  aptychus — resembling  a 
bivalve  shell  widely  opened.  Very  various  opinions  have  been  held 
about  these  bodies ;  some  considering  them  to  be  the  opercula  of  the 
Ammonites,  whilst  Pictet  avowed  that  it  was  difficult  to  j)rouounce 
upon  their  true  affinities.* 

Mr.  C.  Moore  has  already  challenged  the  correctness  of  the 
operculum  view,  and  in  a  fui-ther  paper  f  he  shows  as  the  result  of 

*  For  a  summary  of  the  views  of  English  and  foreign  observers,  with  references, 
see  "  The  Lias  Ammonites,"  T.  Wright, '  Palajoutographical  Soc./  xsxiv.  (1880) 
p.  182. 

t  '  Kept.  Brit.  Assoc,,'  lS7t),  p.  311. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  605 

minute  examinations  of  diflferont  forms,  that  in  every  instance  tlio 
aptyclii  were  almost  entirely  cellular,  and  lines  of  cell-tubes  were 
extracted  from  them,  differing  in  scarcely  any  respect  from  the  egg- 
packets  lying  amidst  the  scattered  eggs  on  the  Ammonites  serpentinus 
of  the  upper  lias.  The  facts  he  has  collected  are,  he  thinks,  scarcely 
consistent  with  the  idea  that  the  aptychus  was  simply  an  operculum, 
but  on  the  contrary  tend  to  the  conclusion  that — possibly  with  the 
siphuucular  tube — it  is  an  ovarian  sac. 

Development  of  the  Pulmonate  Gasteropoda. — The  conclusion 
of  M.  Fol's  essay  on  this  subject,  to  the  introductory  portion  of  which 
we  have  already  directed  attention,*  deals  with  certain  theoretical 
points  of  some  importance. 

Velum. — This  larval  structure,  which  is  found  in  so  many  diflferent 
animals,  generally  takes  the  form  of  an  ectodermal  thickening,  covered 
with  vibratile  cilia  of  a  particularly  large  size  ;  it  is  generally  circular 
in  shape,  and  is  placed  at  the  level  of  the  mouth,  and,  as  a  rule,  a 
little  above  the  buccal  orifice.  In  most  of  the  sea-dwelling  MoUusca 
it  becomes  very  large ;  thus,  the  superior  extremity  of  the  larva 
becomes  an  enormous  sinus,  which  is  filled  by  the  liquid  of  the  body- 
cavity,  and  is  also  provided  with  muscular  fibres.  On  the  other  hand, 
the  Pulmonate  Gasteropoda  have  the  velum  very  small  and  even  rudi- 
mentary ;  the  thickening  is  not  continuous  and  circular,  but  is  only 
developed  at  the  sides ;  it  is,  nevertheless,  provided  with  branching 
contractile  cells,  which  are  only  found  in  the  higher  of  the  marine 
forms ;  so  that,  in  these  land-dwelling  snails  the  velum  is  a  structure 
derived  from  and  reduced  from  the  more  complicated  forms.  But  the 
process  of  reduction  has  not  been  uniform ;  the  "  vibratile  welt "  has 
undergone  more  diminution  than  have  the  sinus  and  the  muscular 
fibres,  and  that  although  these  are  not  the  essential  parts  of  the  velum. 

Hand  in  hand  with  this  change  in  structure,  it  is  evident  that  there 
has  been  some  change  in  function  ;  the  primitive  duty  of  the  velum 
was  that  of  a  locomotor  organ,  to  which  there  was  added  on  the 
function  of  seizing  nutriment ;  in  the  Pulmonate  forms  this  larval 
structure  has  the  function  of  circulating  the  nutrient  fluid. 

The  larval  heart  affords  some  difficulties  ;  in  form  and  structure 
it  closely  resembles  that  of  Buccinmn  and  Purpura ;  but  it  differs  in 
position,  for  they  are  primitively  dorsal,  whereas  that  of  Helix  only 
gradually  leaves  a  ventral  position  ;  we  require  further  information 
before  we  can  say  whether  the  explanation  of  tliis  difference  is  to  bo 
found  in  the  fact  that  the  jiist-mcntioned  forms  leave  the  shell  at  a 
'  later  period  in  development,  or,  whether  they  have  their  heart  and 
pallial  cavity  primitively  placed  on  the  ventral  surface. 

By  most  authors  the  symmetry  of  the  body  has  been  ascribed  to 
the  folding  round  of  the  shell ;  Ihcring,  however,  regards  the  torsion 
of  the  shell  as  due  to  the  asymmetry  of  the  viscera.  ]\[.  Fol  regards 
both  these  opinions  as  too  extreme ;  ho  himself  has  already  shown 
that  in  the  lietcropoda  asymmetrical  arrangements  manifest  them- 
selves at  an  extremely  early  period. 

*  Sec  (intr,  p.  414. 


606  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

In  Helix  and  Limax  the  torsion  docs  not  aj^pcar  so  early,  and  is 
seen  simultaneously  in  the  viscera  and  in  the  shell.  To  explain  the 
phenomena  it  seems  to  be  necessary  to  note  the  process  of  segmenta- 
tion of  the  ovum  ;  but  here  imfortunately  there  is  but  little  informa- 
tion. The  fact  that  organs  like  the  kidneys,  which  are,  as  we  know, 
primarily  double,  are  in  the  youngest  of  Gasteropod  larvaD  single, 
seems  to  show  that  the  asymmetry  is  produced  prior  to  the  commence- 
ment of  the  embryonic  period. 

Stomach  and  Liver. — Here  the  author  directs  particular  attention 
to  the  mode  by  which  the  organs  are  differentiated  from  the  embryonic 
digestive  cavity.  It  is,  in  the  first  place,  necessary  to  make  a  funda- 
mental distinction  between  the  case  where  the  cells  of  the  endoderm 
possess  from  the  first  a  deposit  of  nourishment,  which  comes  to  them 
from  the  yolk — protolecithin — and  that  where  they  borrow  from  the 
yolk  swallowed  by  the  larva,  an  amount  of  nourishment  which  may  bo 
called  deuterolecithin.  The  former  does  not  increase  during  the  period 
of  development,  and  tends  to  diminish  ;  the  latter  appears  during 
that  period  and  is  rapidly  absorbed.  The  former  appears  under  the 
guise  of  globules,  which  are  generally  small;  the  latter  is  formed 
into  compact  and  relatively  large  masses,  and  is  not,  or  need  not  be, 
altogether  derived  from  the  yolk. 

The  Thecosomatous  Pteropoda  afford  an  example  of  the  complete 
absence  of  deuterolecithin  ;  while  in  Firoloides  there  is  but  little  proto- 
lecithin, and  what  there  is,  is  rapidly  absorbed.  In  the  Gasteropoda 
the  embryonic  digestive  cavity  is  bounded  in  part  by  an  endoderm  in 
which  the  cells  are  of  the  ordinary  size,  and  in  part  by  some  very  large 
spherules,  which  are  crammed  with  the  protolecithin  ;  the  small  cells 
of  the  endoderm  so  grow  as  to  shut  off  the  large  spherules  from  their 
connection  with  the  digestive  cavity,  and  these  thus  fall  into  the  body- 
cavity,  where  they  are  simply  absorbed.  Meanwhile  the  small  cells  be- 
come charged  with  deuterolecithin  ;  which,  after  a  time,  disappears  from 
that  part  of  the  wall  which  becomes  the  stomach  and  intestine ;  the 
rest  forms  a  pouch  which  develops  into  the  liver.  These  facts  seem  to 
show  that  that  view  is  incorrect,  which  regards  the  deposition  of 
deuterolecithin  as  a  mere  episode  in  the  development  of  the  liver ;  this 
compound  is  often  absent  from  the  rudiment  of  the  liver,  and  is,  on 
the  other  hand,  often  found  in  structures,  such  as  the  ectodermal 
tissues  of  the  larval  Helix,  which  have  no  relation  to  that  organ. 

Nerve-ganglia. — These  structures  appear  to  arise  by  somewhat 
different  processes :  thus,  Fol  himself  has  observed  that  in  the 
Pteropoda  the  cerebral  ganglia  are  formed  by  an  invagination  of  the 
ectoderm,  while  in  the  Heteropoda  there  is  a  division  of  the  same 
primitive  layer.  Bobretzky  has  found  that  these  ganglia  are  in  the 
Prosobranchiata  formed  by  a  condensation  of  tissue  in  the  mesoderm ; 
in  the  aquatic  Pulmonata,  Fol  has  observed  a  somewhat  similar  pro- 
cess, save  that  the  mesoderm  appears  to  have  been  derived  directly 
from  the  ectoderm ;  in  the  terrestrial  forms  he  has  seen  an  ectodermic 
invagination  which  was  just  as  well  marked  as  in  the  Pteropoda. 

The  auditory  and  optic  organs  exhibit  a  very  similar  diversity ; 
the    Heteropoda,   Prosobranchiata,  and   terrestrial   Pulmonata  have 


INVERTEBRATA,   CRYPTOGAMIA,    MICROSCOPY,   ETC.  GOT 

tlieir  otocysts  formed  by  a.n  iuvaginatiou  of  the  ectoderm,  wliilc 
there  is  a  delamination  of  the  layer  in  the  Pteropoda  and  aquatic 
Pulmonata. 

The  pedal  ganglia,  on  the  other  hand,  exhibit  a  remarkable  con- 
stancy in  their  mode  of  development ;  they  are  always  formed  in  the 
midst  of  a  pre-existing  mesodermal  tissue,  and  can,  therefore,  only  bo 
said  to  be  indirectly  ectodermal  in  origin. 

These  general  considerations  lead  to  still  wider  generalizations ; 
rejecting  the  view  of  Bobretzky  that  the  mode  of  development  must 
be  the  same  tliroughout  any  one  phylum,  M.  Fol  states  his  belief  that 
the  identity  of  embryonic  processes  is  not  to  be  assumed  but  is  to  bo 
demonstrated ;  and,  looking  at  all  the  facts,  he  comes  to  the  conclu- 
sion that  the  processes  of  invagination  and  of  delamination  may  bo 
derived  from  one  another,  and  that  they  have  not  the  importance 
which  is  often  attributed  to  them. 

Benal  Glands. — The  Pulmonato  Gasteropoda  are  interesting  as 
being  provided  with  a  larval  kidney,  which  among  the  Mollusca  has 
as  yet  been  only  observed  in  Paludina  and  in  a  marine  Prosobranch ; 
paired,  it  is  evidently  of  the  same  category  as  the  segmental  organs  of 
the  Vermes  ;  the  permanent  kidney  is  unilateral,  it  is  never  developed 
along  the  median,  but  always  on  the  side  on  which  growth  is  predomi- 
nant. The  larval  and  permanent  kidneys  are  very  similar  in  structure, 
but  they  differ  from  one  another  in  the  fact  that  the  inner  pore  of  the 
larval  kidney  opens  into  the  body-cavity,  while  that  of  the  permanent 
one  opens  into  the  pericardium ;  this  is  not,  however,  a  ditference  of 
prime  importance.  A  more  important  question  relates  to  the  "  typical  " 
presence  of  two  pairs  of  renal  glands  in  the  Mollusca,  but  this  is  a 
question  which  cannot  yet  be  answered. 

General  Homologies  of  the  Larval  Pulmonata. — The  Pteropoda 
appear  to  be  those  of  the  Cephalophora  which  have  most  completely 
retained,  in  their  larval  stage,  the  velum  so  common  among  the  Vermes ; 
they,  too,  have  the  cerebral  ganglia  most  directly  derived  from  the 
ectoderm.  In  these,  and  some  other  points,  the  Pulmonata  are  tho 
most  divergent  of  the  Cephalophorous  Mollusca.  So  far  as  tho 
digestive  tract  is  concerned,  they  are  only  remarkable  for  the  great 
quantity  of  dcutcrolccithin.  The  larval  kidneys  do  not  find  their 
representative  in  the  larva)  of  tlic  Annelids  or  of  Pohjfjordius,  but 
the  permanent  pair  (for  paired  they  really  are)  completely  corresponds 
in  position  and  structure  to  the  excretory  organs  of  tho  Rotifera  and 
to  the  first  pair  in  the  larva  of  Polijgordius. 

It  is  impossible  to  compare  tho  moUuscan  larva  with  a  segmented 
worm-larva  ;  they  only  correspond  to  the  cephalic  portion  of  the  larva 
of  an  Annelid,  or  to  an  entire  Rotifer  ;  tho  Mollusca  aronot  segmented 
animals  which  have  fused  their  metamercs,  but  thoy  arc  animals 
whicli  have  remained  simple. 

In  conclusion,  tho  author  points  out  how  recent  observations  tend 
to  favour  the  re-establishment  of  the  Vermes  of  Linnajus ;  tho  larval 
form  (Lovenian,  vcligcr,  trochoi)horc)  can,  with  variations  in  form,  bo 
traced  through  "  worms,"  Annelida,  Bryozoa,  Brachiopods,  and  even 
EchinodcrniK,  and  tliese  all  form  a  phylum  distinct  from  that  of  the 


608  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

Arthropocla  on  tlio  one  liand,  and  of  the  Cliordata  (Timicata  and 
Vertebrata)  on  the  other. 

Generative  Organs  of  the  Young  Helix  aspersa.* — M.  Jourdain 
has  made  some  interesting  observations  on  this  subject,  which  are  of 
value  from  the  wide  view  which  the  author  has  taken  ;  none  who  have 
been  engaged  with  these  organs  will  be  sorry  to  hear  of  M,  Jourdain's 
attempt  to  "  preciser  la  terminologie,"  and  in  the  presence  of  so  many 
different  modes  of  stating  observations,  it  will  not  be  useless  to 
detail  our  author's  synonymy  of  the  chief  parts  of  this  somewhat 
complex  apparatus : — 
Hermaphrodite  gland  ,.  Ovary;  testicle;  racemose  gland. 
„  „       .    I     ,     J.  r.  ( Oviduct ;  primary  oviduct ;  efferent  canal ;   fallo- 

Efferent  duci  of  herma-       ^.^^^  ^^^^^  ^^^^^'^^^  deferens  (both  invaginated)  ; 
phroditc  gland   . .      , .  j     g^gj.ent  canal  of  the  hermaphrodite  gland. 

.,,       .   .  ,     J      CEoe ;    testicle;     ovary;     "glaire";     muciparous 

Albummiparous  gland  . .  |     ^^^^^^ .  ^^^^^^^^  ^^J^] 

„       ,  ,  ,  (Pedunculated  vesicle ;   urinary  bladder;   recepta- 

Copulatory  pouch  ..      ..|     culura  seminis. 

Muciparous  glands        ..   Multiiid  vesicles  ;  multifid  prostate. 
Genital  vestibule   ..      ..   Genital  cloaca. 
Spermatophore       ..      ..   Capreolus. 

Young  specimens  of  H.  aspersa  are  very  far  from  exhibiting  all 
these,  with  other,  parts  ;  in  them,  the  hermaphrodite  gland  is  composed 
of  a  small  number  of  follicles,  and  they  give  off  an  efferent  canal,  with 
a  straight  course;  this  rapidly  increases  in  diameter  and  divides 
lengthwise  into  an  efferent  and  an  ovigerous  demi-canal ;  the  former 
exhibits  as  yet  no  indications  of  a  prostate,  the  latter  has  on  it  the 
rudiments  of  the  albuminiparous  glands ;  the  two  tubes  soon  separate 
and  the  efferent  duct  becomes  a  complete  canal ;  as  soon  as  this  is 
effected  this  latter  forms  a  loop  which  gradually  grows  out  to  form  the 
penis.  The  flagellum  is  not  yet  developed  ;  there  is  no  dart-sac,  and 
as  yet  there  are  no  muciparous  glands.  These  last  are  in  time  derived 
from  two  small  diverticula  which  are  developed  at  the  base  of  the 
oviduct,  and  the  differences  observed  in  different  species  are  merely 
due  to  differences  in  the  growth  of  these  parts ;  thus,  if  one  is  absorbed 
we  find  the  single  muciparous  gland  of  H.  ohvoluta ;  when  they  are 
both  developed  but  remain  undivided,  we  have  the  form  found  in  if. 
cornea  and  others  ;  when  one  bud  subdivides,  we  have  the  arrangement 
found  in  H.  Bangiana,  and  so  on  to  the  extreme  form  of  H.  pomatia. 

Gasteropoda  from  the  Troas-t — In  giving  a  list  of  the  compara- 
tively large  number  of  forms  brought  home  by  Professor  Virchow, 
Von  Martens  points  out  that  all  the  species  are  now  to  be  found  living 
in  the  Mediterranean ;  speaking  generally,  they  exhibit  no  differences 
as  compared  with  more  modern  forms.  Those  not  used  for  the  pro- 
duction of  ptirple  were,  for  the  most  part,  probably  used  for  food,  as 
are  many  of  the  same  species  at  the  present  time. 

Gasteropoda  from  the  Auckland  Islands.^ — In  giving  a  note  on 
the  specimens  collected  in  these  islands,  the  same  zoologist  describes 

*  'Eev.  Sci.  Nat.,'  i.  (1880)  p.  449. 

t  '  SB.  Ges.  naturf.  Freunde,'  Berlin,  1879,  p.  8G.  %  Ibifl.,  p.  .S7. 


INVERTEBKATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  609 

a  new  species  of  Meaoderma — M.  auchlandicimi — which  is  somewhat 
similar  to  M.  novce-zealandice.  He  fiu-ther  points  out  that  in  its  black 
coloration  Trochus  nirjerrimus  brings  to  mind  allied  species  from  the 
South  African  and  South  American  seas,  while  the  green,  at  its  base, 
reminds  one  of  the  Chinese  form,  T.  argyrostomus. 

Molluscoida. 

Marine  Polyzoa.* — The  Eev.  T.  Hincks  has  commenced  a  series 
of  papers  in  which  he  proposes  to  describe  and  figure  a  large  number 
of  marine  Polyzoa  from  various  parts  of  the  world  which  have 
hitherto  escaped  notice,  and  thus  to  offer  a  contribution  towards  that 
general  history  of  the  class  which  still  remains  to  be  ^Titten. 

It  is  not  intended  to  be  confined  to  bare  diagnosis,  and  the  follow- 
ing points  especially  will  receive  elucidation : — (1)  Geographical  dis- 
tribution— any  new  localities  for  known  species  will  be  recorded  ; 
(2)  local  variation — the  differences  exhibited  by  the  same  tyj)e  under 
differing  circumstances  will  be  noted  whenever  the  opi^ortunity 
presents  itself  of  comparing  specimens  of  the  same  species  from 
various  parts  of  the  world  ;  (3)  the  limits  of  variability  in  each  case, 
and  the  elements  of  structure  most  liable  to  variation ;  (4)  the  true 
principles  of  classification.  With  the  descriptions  of  new  forms  will 
be  combined  notes  on  such  as  are  little  known  or  misunderstood  ; 
and,  so  far  as  space  will  permit,  in  the  case  of  each  genus  the  number 
of  species  already  ranked  under  it  will  be  indicated  and  its  geogra- 
phical range.  These  papers  will  therefore  serve  as  an  index  to  the 
foreign  species  which  have  already  been  described,  as  well  as  an 
introduction  to  many  that  are  new.  The  classification  employed  will 
be  that  of  the  author's  '  History  of  the  British  Marine  Polyzoa,'  so 
far  as  it  apjilies,  and  with  such  modification  as  may  be  suggested  by 
an  increased  knowledge  of  the  morphology  of  the  tribe.  A  biblio- 
graphical list  will  be  appended  containing  the  principal  faunistic  and 
other  works  which  deal  with  the  foreign  sjiecies. 

The  series  commences  with  some  Madeiran  Polyzoa  collected  by 
Mr.  J.  Y.  Johnson,  and  six  new  species  are  described  and  figured. 
This  is  followed  by  descriptions  and  figures  of  other  specimens  from 
Australia  and  elsewhere,  including  eleven  new  species  and  one  now 
genus  (Sijihonoporella). 

Fresh-water  Polyzoa.f — The  ovum  of  Alcyonclla  fungosa  is  com- 
posed, according  to  W.  Reinhardt,  of  transparent  gi-anular  protoplasm, 
and  has  a  largo  clear  nucleus  and  a  nucleolus.  Later,  but  while 
the  nucleus  and  nucleolus  are  still  distinguishable,  appear  at  the 
periphery  unifurm,  refracting  lumps — those  described  as  cells  by 
Allinan.  Generally  only  one  of  tlic  ova  in  the  ovary  develops.  The 
nucleus  enlarges  so  much  as  to  touch  the  margin  of  the  denser  proto- 
plasm ;  it  contains  a  delicate  protoplasmic  network.  The  sperma- 
tozoon consists  of  a  strongly  i-efringcnt  substance  enveloped  by  a 
membrane  ;  its  head  is  round,  but  ends  in  a  point,  and  is  separated  by 

*  '  Ann.  and  Mag.  Nat.  Hi.st.,'  vi.  (1880)  p.  fiO. 
t  *  Zool.  Anzfip.,'  iii.  (1^80)  pp.  208,  2M. 
VOL.    III.  2   R 


610  RECORD   OF   CURRENT   RESEARCHES   RELATING    TO 

a  septum  from  tho  tail  wLicb  is  purely  protoplasmic ;  it  originates  from 
a  nucleolus  which  is  similarly  refringent.  On  becoming  attached  to  the 
ovimi  its  central  part  contracts  into  a  lumj)  on  which  the  head  rests, 
and  the  whole  becomes  covered  by  a  membrane  proceeding  from  the 
side  of  the  head.  After  segmentation  the  mass  is  converted  into  a 
gastrula  by  invagination ;  the  gastrula-mouth  closes  and  the  segmen- 
tation cavity  disappears,  and  a  ring-shaped  depression  appears  in 
front  enclosing  a  space  which  becomes  the  wall  of  the  future  cystid. 
Three  layers  are  now  present  in  the  body  ;  tho  outer  layer,  the  tunica 
muscularis,  and  the  entoderm.  The  cells  of  the  ring  or  "  cap " 
lengthen  and  become  connected  with  fibres ;  the  polypides  which 
develop  within  it  j)ush  out  the  external  membrane  round  them  ;  the 
cilia  of  this  membrane  cease  moving,  and  its  layers  of  cells  unite  and 
then  break  up  into  long  homogeneous  separate  cells  ;  in  many  cases 
this  mass  of  cells  forms  a  long  process  at  the  side  of  the  cystid,  and 
sometimes  even  increases  in  size ;  its  further  development  was  not 
observed,  but  after  a  time  it  was  seen  to  be  absorbed  into  the  cystid  ; 
it  probably  represents  the  stolon  of  marine  Polyzoa. 

The  structure  taken  for  an  ooecium  by  Nitsche  and  Metschnikoff 
appears  to  be  an  extension  of  the  ovarian  membrane,  with  which  it 
corresponds  in  position,  in  its  unilaminar  structure,  and  in  containing 
embryos  in  stages  too  early  for  their  emergence.  By  the  formation 
of  the  embryo,  the  polypides  adjoining  it  appear  to  be  destroyed  and  to 
form  the  "  brown  bodies  " ;  through  the  openings  left  by  their  dis- 
appearance the  embryo  issues  forth ;  the  statohlast  originates  in  the 
same  Avay,  and  also  at  the  expense  of  the  aborted  polypides.  The 
digestive  canal  is  developed  from  the  internal  layer  of  the  capsule 
which  encloses  the  embryo,  and  not  from  a  specially  separated  group 
of  cells,  as  Hatschek  states. 

With  regard  to  Cristatella  mucedo,  the  author  gives  the  following 
preliminary  account  of  the  development  : — 

The  cystid  consists,  as  in  Alcyonella,  of  an  ectoderm,  a  median 
layer  (the  tunica  muscularis),  and  an  entoderm.  Thus  Hatschek  must 
be  wrong  when  he  names  the  inner  layer  of  the  bud,  mesoderm  ;  and 
his  description  of  the  budding  is  inexplicable  by  comparison  with  the 
above-mentioned  details,  though  these  may  perhaps  correspond  with 
his  second,  unknown,  process  of  budding.  The  bud  develops  by  a 
thickening  of  the  ectoderm  into  which  the  entodermic  cells  are 
pushed ;  there  is  no  indentation  of  the  former.  The  tunica  muscu- 
laris is  very  early  formed ;  the  cavity  of  the  tentacle-sheath  is 
separated  later  from  the  alimentary  canal,  and  the  lophophore  is 
formed  by  an  invagination  into  this  tentacle-sheath.  The  later  deve- 
lopment of  the  buds  corresponds  with  that  described  by  Nitsche  in 
Alcyonella.  The  statoblasts  consist  of  a  uniform  granular  mass, 
covered  with  the  cylindrical  cells  of  the  ectoderm,  under  which  cells 
lies  a  layer  of  nuclei ;  the  layers  increase  in  number,  the  tunica 
muscularis  appearing  first ;  the  entoderm  was  hid  by  the  opacity  of 
the  central  mass. 

The  well-known  concerted  movements  of  the  colony  are  explained 
by  the  structure  of  the  common  base,  which  contains  suckers  formed  by 


mvERTEBRATA,   CRYPTOGAMIA.,    MICROSCOPY,   ETC.  Gil 

invaginations,  broad  internally,  drawn  out  externally  into  necks ; 
these  suckers  arc  arranged  in  rows  at  right  angles  to  the  axis  of  the 
colony. 

Larva  of  Bowerbankia.* — By  way  of  correction  of  and  supiilemcut 
to  Lis  j)revious  papers  on  BowerbanJcia,^  W.  RepiachofF  says  that 
the  part  there  described  as  a  mouth  and  commented  on  as  being 
exactly  opposite  in  position  to  the  mouth  of  the  Chilostomata  docs  not 
lead  into  the  digestive  cavity  at  all,  but  is  simjily  a  ciliated  depression 
of  the  epithelium,  and  has  no  morphological  connection  with  the 
chilostomatous  mouth.  The  organization  of  the  larva  is  now  seen 
to  be  more  complicated  than  was  previously  stated ;  the  external  epi- 
thelium is  lined  on  its  inner  face  by  a  connective-tissue  layer,  specially 
thickened  at  certain  points  :  in  the  body  proper  is  found  a  mass  of 
cells  considered  to  be  the  homologue  of  the  glandular  intestinal  layer : 
at  the  lower  part  of  the  body  occurs  a  paired  mass  of  pear-shaped 
cells  which  stain  deeply  with  carmine,  indigo-carmine,  and  hfema- 
toxylin,  and  are  regarded  as  representing  the  "  cement  glands  "  of  the 
Entop-octa. 

Euktiminaria  ducalis.:}: — The  Ecv.  J.  E.  Tenison-Woods  recently 
described  §  what  he  considered  to  be  a  new  genus  of  Polyzoa  under 
the  above  name,  and  mentioned  that  similar  fossils  had  been  found  in 
the  chalk,  and  that  M.  d'Orbigny  had  suggested  that  they  were 
ComatuliB  without  arms.  The  author  is  now  convinced  that  this 
explanation  of  these  bodies  is  the  correct  one.  They  are  the  central 
disks  of  some  unknown  species  of  Co7Jia<M?ce,  and  he  has  seen  a  central 
disk  of  an  undescribcd  species,  which  though  much  smaller  and  with 
very  much  fewer  pores,  yet  is  so  similar  in  all  other  respects  that  he 
does  not  doubt  that  Euldiminaria  ducalis,  the  Glenotremiles  paradoxus 
of  Goldfuss,  and  the  Decamerus  mijsticiis  of  Ilagenow,  are  all  central 
disks  of  Comatulce.  The  central  pores  on  each  of  these  organisms  which 
bear  so  close  a  resemblance  to  the  cells  of  Polyzoa  are  doubtless  con- 
nected with  the  water  circulation,  like  the  madreporiform  bodies  in 
the  Echinodcrmata.  They  are  not  present  in  all  the  Comatuhe,  at 
least  in  this  form. 

Arthropoda. 

Nervous  Collars  of  Arthropods.!  —  M.  Lienard  gives  diagram- 
matic figures  of  the  (csoiihagcal  rings  of  Cossus  li(in'q)crda,  eight 
other  Hexapods,  and  two  Myriopods.  He  has  studied  more  than 
sixty  genera  of  Arthrojiods,  whoso  nervous  collars  he  arranges  under 
four  types. 

1.  Type  of  Crustacea. — Oesophageal  connectives  (  =  longitudinal 
commissures)  very  long ;  transverse  commissure  straight,  at  some 
distance  in  front  of  the  sub-a'sophagcal  ganglion  :  Crustaceans  (except 
Isopods),  Myriopods  (Glomcris  limhata)  and  Ilexapods  (Gryllus  cam- 

*  'ZfK.l.  AnzciK.,'  iii.  (1880)  p.  2G0. 

t  Iliiil  ,  ii.  (l^T'.i)  p.  (JdO,  find  i.  (1878),  No.  10.     Sec  ante,  p.  238. 

X  '  Tnic.  Limi.  Soc.  N.  S.  Wnlcs,'  iv.  (18S0)  p.  310. 

§  See  tliis  .Tnnrniil,  ii.  (1S7'.»)  p.  707. 

II  '  Anh.  «lc  Biologic,'  i.  (1H80)  pp.  381-391  (1  plate). 

2   S    2 


612  EECORD   OF   CURRENT   RESEARCHES  RELATZNG   TO 

peatris,  Blaps  mortisaga,  Necrophorus  vestigator,  N.  germanicus,  Pierts 
hrassicce  (caterpillar),  Periplaneta  orientalis). 

2.  Tyjie  of  Dytiscus. — Connectives  extremely  short ;  transverse 
commissure  apjiosed  to,  but  independent  of,  the  sub-oesophageal 
ganglion :  wood-lice,  dragon-flies,  Phryganea,  and  various  beetles. 

3.  Type  of  Cossus  ligniperda  (first  described  by  Lyonnet). — Con- 
nectives of  variable  length ;  transverse  commissure  springing  from 
the  supra-oesophageal  ganglion,  together  with  or  on  the  inner  side  of 
the  connectives,  and  closely  embracing  the  gullet  under  the  form  of  a 
vertical  sling  or  loop :  various  Myriopods,  caterpillars,  Orthoptera, 
Coleoptera,  and  the  larva  of  Tenthredo. 

4.  l^ype  of  Suctorial  Hexapods.  —  Connectives  very  short  and 
stout;  transverse  commissure  under  one  perineurium  with  the  sub- 
cesojihageal  mass  :  Hemiptera,  adult  Lepidoptera,  and  Diptera. 

Adult  Hymenoptera  did  not  give  satisfactory  results.  Arachnids 
remain  to  be  examined.  In  Crustaceans  it  is  known  that  the  trans- 
verse commissure  passes  on  either  side  into  a  small  ganglionic  mass 
from  which  fibres  proceed  to  the  brain.  Similar  centres,  save  that 
they  are  closer  to  the  brain,  occur  in  Myriopods  and  Hexapods,  as 
shown  by  Leydig  for  Dytiscus.  This  commissure  has,  therefore,  no 
direct  relation  with  the  lateral  "  connectives."  M.  Lienard  hopes  to 
show,  in  a  future  paper,  the  fundamental  unity  of  arrangement  of  the 
cephalic  nervous  centres  throughout  the  Arthropoda. 

«•  Insecta. 

Nerve-endings  in  Muscles  of  Insects.* — Dr.  Foettinger  asserts, 
with  Engelmann,  the  direct  continuity  of  nerve  and  muscle.  He 
examined  various  beetles,  caterpillars,  and  the  cockroach.  For  his 
modes  of  preparing  these  subjects  we  must  refer  to  the  original  paper. 
His  researches  were  carried  on  in  the  laboratories  of  Professors 
E.  Van  Beneden  and  Engelmann. 

The  presence  of  a  nervous  network  within  the  proper  substance 
of  the  muscle-cylinders  is  here  denied.  Each  muscular  fibre  has 
usually  several  nerve-end  organs,  or  mounds  of  Doyere,  beneath  the 
Barcolemma.  Thus,  Hydropliilus  piceus  may  have  six.  Chrysomela 
ccerulea  showed  nine  of  Doyere's  cones  in  the  space  of  one  millimetre; 
while  in  Passalus  glaberrimus  along  thrice  the  same  extent  of  muscle 
but  four  or  five  could  be  counted.  At  the  summit  of  Doyere's  organ  the 
axis-cylinder  divides  into  a  number  of  fibrils,  which,  upon  reaching 
the  base  of  the  cone,  immediately  pass  into  the  muscular  substance 
at  the  level  of  the  intermediate  disks.  In  this  sense  Dr.  Foettinger 
modifies  the  hypothesis  of  Engelmann  (who  saw  some  of  his  prepara- 
tions) as  to  the  connection  between  the  ultimate  nerve-fibrils  and  the 
isotropic  bands.  One  nerve  may  bifurcate  to  supply  two  of  Doyere's 
cones.  From  the  apex  of  each  of  these  as  many  as  seven  fibrils 
sometimes  diverge.  The  fibrils  often  seem  to  pass  through  the  sub- 
stance of  the  cone,  at  some  distance  from  its  surface,  and  a  like 
striated   appearance   is    shown   by  cones  which   have  been  broken 

*  '  Arch,  de  Biologie,'  i.  (1880)  pp.  279-304  (1  plate). 


INVERTEBRATAj    CRYPTOGAMIA,   MICROSCOPY,    ETC.  CI 3 

across, — facts  which  cause  the  observer  to  conclude  that  the  striae 
are  true  fibrils,  and  not  mere  folds  of  sarcolemma.  The  author  also 
found  several  planes  of  fibrils  mthin  a  single  cone.  In  other  cases 
the  fibrils,  injured  probably  by  reagents,  were  replaced  by  rows  of 
granules. 

The  author  maintains,  against  Eanvier,  the  normal  occurrence  of 
true  muscular  waves.  In  the  passage  from  the  state  of  repose  to  that 
of  complete  contraction  several  phases  may  be  observed.  First,  the 
intermediate  disks  ( =-^  Zwischenscheiben)  and  the  accessory  disks 
(=  Nebenschciben)  become  less  and  less  distinct,  then  quite  dis- 
appear ;  the  borders  of  the  transverse  disks  ( =  Querscheiben)  are 
gradually  obscured  and  form  two  black  streaks  (Contractionscheiben 
of  Nasse)  limiting  the  isotropic  substance  ;  the  clear  median  disk 
(=  Mittelscheibe)  slowly  retires  from  view  and  is  replaced  by  an 
obscure  line,  which  during  further  contraction  vanishes  in  its  turn. 
The  "  Contractionscheiben,"  formed  by  the  two  primitive  anisotropic 
disks,  approach  and  fuse  into  a  single  dark  disk.  In  full  contraction 
alternating  dark  and  clear  disks  can  alone  be  seen.  The  contrac- 
tions which  begin  in  the  regions  supplied  by  Doyere's  cones  proceed 
in  opposite  directions  along  the  intervening  portions  of  the  muscular 
fibre. 

Habits  of  Ants. — Sir  John  Lubbock  has  laid  before  the  Linnean 
Society  *  the  results  of  his  further  observations  on  this  subject. 

The  paper  commences  by  an  account  of  fresh  experiments  on  the 
powers  of  communication  of  ants.  Among  others,  a  dead  bluebottle 
fly  was  pinned  down,  and  after  vain  efforts  at  removal  the  selected 
ant  hied  home,  and  emerged  with  friends  who  slowly,  and  evidently 
incredulously,  followed  their  guide.  The  latter  starting  off  at  a  great 
pace  distanced  them,  and  they  returned,  again,  however,  to  be  in- 
formed, come  out,  and  at  length  be  coaxed  to  tlie  prey.  In  the  several 
experiments  with  different  species  of  ants  and  under  varied  circum- 
stances, these  seem  to  indicate  the  possession  by  ants  of  soraething 
approaching  language.  It  is  impossible  to  doubt  that  the  friends 
were  brought  out  by  the  first  ant,  and  as  she  returned  empty-handed 
to  the  nest  the  others  cannot  have  been  induced  to  follow  merely  by 
observing  her  proceedings.  Hence  the  conclusion  tbat  they  possess 
the  power  of  requesting  their  friends  to  come  and  help  them. 

For  other  experiments  testing  the  recognition  of  relations,  although 
the  old  ants  had  absolutely  never  seen  the  young  ones  until  the 
moment,  some  days  after  arriving  at  maturity,  that  they  were  intro- 
duced into  the  nest,  yet  in  all  cases  they  were  undoubtedly  recognized 
as  belonging  to  the  community.  It  would  seem,  therefore,  to  bo 
established  that  the  recognition  of  ants  is  not  personal  and  individual, 
and  tbat  tlieir  harmony  is  not  due  to  the  fact  that  each  ant  is 
acquainted  with  every  other  member  of  the  community.  It  woukl 
further  apj)ear  from  the  fact  that  they  recognize  tlieir  friends  even 
when  intoxicated,  and  that  they  know  the  young  born  in  their  own 
nest,  even  when  they  have  been  brought  out  of  the  chrysalis  by 

*  Juno  17. — Not  yet  piihlislicd. 


"614  BECOED  OF   CUERENT  EESEAECHES  RELATING  TO 

Btrangers,  indicating,  therefore,  that  the  recognition  is  not  effected 
by  means  of  any  sign  or  password. 

With  regard  to  workers  breeding,  the  additional  evidence  tends  to 
confirm  previously  advanced  views,  that  whefi  workers  lay  eggs  males 
are  always  the  issue  of  these.  Without  entering  into  details  of 
instances,  it  may  broadly  be  affirmed  that  in  the  queenless  nests  males 
have  been  produced,  and  in  not  a  single  case  has  a  worker  laid  eggs 
which  have  produced  a  female,  either  a  queen  or  a  worker.  On  the 
contrary,  in  nests  possessing  a  queen,  workers  have  been  abundantly 
produced.  The  inference  from  these  curious  physiological  facts  leads 
to  the  presumption  that,  as  in  the  case  of  bees,  so  also  in  ants,  some 
special  food  is  required  to  develop  the  female  embryo  into  a  queen. 

In  Sir  John's  nests,  while  from  accidents  and  other  causes  many 
ants  are  lost  during  the  summer  months,  in  winter,  nevertheless, 
there  are  few  deaths.  As  to  the  age  attained,  specimens  of  Formica 
fiisca  and  F.  sanguinea,  still  lively,  are  now  four  and  others  five  years 
old  at  least. 

The  behaviour  to  strange  queens  often  results  in  their  being 
ruthlessly  killed  ;  yet  as  communities  are  known  to  have  existed  for 
years,  queens  must  cccasionally  have  been  adopted.  With  the  view 
of  trying  how  far  dislike  and  passion  might  be  assuaged  by  a  formal 
temjjorary  acquaintance,  a  queen  of  F.  fusca  was  introduced  into  a 
queenless  nest,  but  protected  by  a  wire  cage,  and  after  some  days  the 
latter  removed,  but  the  queen  was  at  once  attacked.  Mr.  McCook, 
nevertheless,  relates  an  instance  of  a  fertile  queen  of  Cremastogaster 
lineolata  having  been  adopted  by  a  colony  of  the  same  species.  Such 
difference  in  conduct.  Sir  John  suggests,  may  be  due  to  his  own  ants 
having  been  living  in  a  republic ;  for  it  is  affirmed  that  bees  long 
without  a  queen  are  strongly  averse  to  adoj)t  or  accept  another. 
Furthermore,  if  a  few  ants  from  a  strange  nest  are  put  along  with  a 
queen  they  do  not  attack  her,  and  if  other  ants  are  by  degrees  added 
tbe  throne  is  ultimately  secured. 

In  pursuance  of  experiments  to  test  the  sense  of  direction,  some 
ants  were  trained  to  go  for  their  food  over  a  wooden  bridge  made  up 
of  segments.  Having  got  accustomed  to  the  way,  afterwards  when 
an  ant  was  in  the  act  of  crossing,  a  segment  was  suddenly  reversed  in 
direction,  evidently  to  the  ant's  discomfiture ;  she  then  either  turned 
round,  or,  after  traversing  the  bridge,  would  return.  When,  how- 
ever, similar  pieces  of  wood  were  placed  between  nest  and  food,  and 
the  ant  at  the  middle  piece,  those  at  the  ends  being  transposed,  the 
ant  was  not  disconcerted.  In  other  instances  a  circular  pajier  disk 
was  placed  on  a  paper  bridge,  and  when  the  ant  was  on  the  disk  this 
was  revolved,  but  the  ant  turned  round  with  the  paper.  A  hat-box 
with  holes  of  entrance  and  exit  pierced  at  opposite  sides  was  planted 
across  the  line  to  the  food  ;  when  the  ant  had  entered  and  the  box  was 
turned  round,  the  ant  likewise  wheeled  about,  evidently  retaining  her 
sense  of  direction.  Again,  with  the  insect  en  route-  when  the  disk  or 
box  with  the  ant  within  was  merely  shifted  to  the  opposite  side  of  the 
food  without  being  turned  round,  the  ant  did  not  turn  round,  but 
continued  in  what  ought  to  have  been  the  direction  to  the  food,  and 


INVERTEBRATA,   ORYPTOQAMIA,    MICROSCOPY,   ETC.  615 

evidently  was  surprised  at  tlie  result  on  arrival  at  tlie  spot  wlicre  the 
food  had  previously  been. 

To  ascertain  whether  ants  make  sounds  audible  to  one  another 
the  use  of  the  telephone  was  resorted  to,  but  the  results  were  negative. 
These  experiments  may  not  be  conclusive,  for  the  plate  of  the  tele- 
phone may  be  too  stiff  to  be  set  in  vibration  by  any  sounds  which  the 
ants  produced. 

As  opposed  to  the  opinion  expressed  by  M.  Dewitz,  Sir  J.  Lubbock 
regards  the  ancestral  ant  as  having  been  aculeate,  and  that  the  rudi- 
mentary condition  of  the  sting  in  Formica  is  due  to  atrophy,  perhaps 
attributable  to  disuse. 

A  ground-plan  of  the  nest  of  Lasius  niger  is  given,  which  exhibits 
an  intricate,  narrow,  and  winding  entrance-passage ;  the  main  nest 
cavity  is  further  supported  by  pillars,  and  here  and  there  by  islands ; 
protected  recesses  obtain,  evidently  strategical  retreats  in  times  of 
danger. 

Studying  the  relations  and  treatment  of  the  aphides,  or  plant-lice 
of  the  ants.  Sir  John  clearly  demonstrates  that  not  only  are  the  aphides 
kept  and  protected  in  the  ants'  nests,  but  the  eggs  of  ApMs  laid  out- 
siiie  on  the  leaf-stalks  of  its  food-plant  in  Octobei',  when  exjiosed  to 
risks  of  weather,  are  carefully  brought  by  the  ants  into  their  nests, 
and  afterwards  tended  by  them  during  the  long  winter  moutlis  until 
March,  when  the  young  ones  are  again  brought  out  and  jilaced  on  the 
young  vegetable  shoots.  This  proves  prudential  motives,  for  though 
our  native  ants  may  not  lay  up  such  great  supplies  of  winter  stores 
of  food  as  do  some  of  those  found  abroad,  they  thus  nevertheless  take 
the  means  to  enable  them  to  procure  food  during  the  following 
summer.  The  fact  of  European  ants  not  generally  laying  up 
abundant  stores  may  be  due  to  the  nature  of  their  food.  Insects 
and  small  animals  form  portions  of  their  food,  and  these  cannot 
always  be  kept  fresh.  They  may  also  not  have  learnt  the  art  of 
building  vessels  for  their  honey,  probably  because  their  young  are 
not  kept  in  cells  like  those  of  the  honey-bee,  and  their  pupfe  do  not 
construct  cocoons  like  those  of  the  humble-bee.  Relatively  to  their 
size  our  English  ants  nevertheless  store  proportionally;  for  if  tho 
little  brown  garden  ants  be  watched  milking  their  aphides,  a  marked 
abdominal  distension  is  observable. 

The  paper  concludes  with  the  history  and  technical  description 
of  a  new  species  of  Australian  honey-ant.  This  corroborates  West- 
mael's  strange  account  of  the  IMexican  species ;  certain  individual 
ants  being  told  off  as  receptacles  for  food — in  short  they  become 
literally  animated  honey-pots. 

Respiratory  and  Circulatory  Apparatus  of  Dipterous  Larvae.* — 
The  larvie  examined  by  M:  Vialhiues  appeared  to  belong  to  the  genus 
CtcnopltDra.  lie  describes  tho  dorsal  vessel  of  a  yoinig  larva  as  a  long 
contractile  tube,  which  is  only  open  at  its  two  extremities.  In  the  last 
Bogment  of  tho  body  there  is  a  median  enlargement,  and  there  are  two 
stigmata  at  its  margins  which  give  off  two  lui-ge  longitudinal  trachea). 

♦  'Cumi.tcd  llciuhis,'  xc.  (1880)  p.  IISO. 


616      KECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

These,  almost  at  oncn,  give  oflf  a  number  of  tracheal  branches,  which 
divide  but  little  and  terminate  in  the  cavity  of  the  last  ring,  in  which 
they  are  so  numerous  as  almost  completely  to  fill  it.  As  the  cardiac 
tube  opens  widely  into  this  last  ring,  we  find  a  cavity  full  of  blood  and 
containing  an  enormous  number  of  trachea.  The  method  of  action  is 
as  follows  :  when  the  vessel  contracts,  the  blood  is  driven  into  the  last 
ring;  here  it  is  easily  oxidized;  when  the  posterior  end  dilates,  the 
blood  passes  in,  and  as  the  entrance  is  fenced  by  a  trellis-work  of 
tiachete  no  blood-corpuscles  can  escape  the  influence  of  the  oxygen. 
Here,  then,  "the  respiratory  function  is  localized  in  the  terminal 
segment,  and  the  dorsal  vessel  is  an  arterial  heart." 

Some  way  behind  the  anterior  orifice  the  dorsal  vessel  is  covered 
by  large  cells,  for  which  the  author  proposes  the  name  of  pericardiac 
cells  ;  these  become  greatly  developed  and  connected  with  the  sides  of 
the  body  ;  they  thus  form  the  primitive  pericardiac  sinus.  The  point 
of  origin  of  the  future  lateral  orifices  is  indicated  by  spots  of  greater 
contractility,  where  the  pericardiac  cells  are  not  developed. 

Development  of  the  Blepharoceridse.* — Under  the  title  of  '  An 
Unknown  Discovery  made  by  Fritz  Miiller,'  Professor  F.  Brauer 
points  out  that  the  developmental  history  of  the  Dipteran  group  of 
BlepJiaroceridce  has  hitherto  remained  unknown,  and  in  consequence 
its  systematic  position  has  been  uncertain.  He  has  discovered  in  an 
elaborate  unpublished  work  by  Fritz  Miiller,  a  fly  described  as  new 
under  the  name  of  Cunqnra  torrentium ;  this,  however,  he  identifies 
with  the  genera  Paltosoma,  Schiner,  and  Hapalothrix,  Low,  although 
the  new  species  is  Brazilian  and  the  latter  genus  is  from  Monte 
Eosa, 

Now  certain  Dipteran-nymphs  of  remarkable  structure  in  the 
Vienna  Museum,  and  coming  from  the  Tyrol,  prove  to  be  exactly  like 
the  pupae  assigned  by  F.  Miiller  to  Cariqnra.  Their  form  is  a  half 
oval  and  they  are  attached  to  stones  by  a  flat  transjiarent  side.  On 
the  removal  of  the  insect  from  its  case  the  venation  of  the  wings  was 
seen  to  correspond  exactly  with  that  of  Blepharocera  fasciata  West, 
showing  the  secondary  vein  peculiar  to  the  family.  Probably  the 
larv^  of  other  genera  resemble  those  of  F.  MuUer's  species,  which 
must  stand  as  Paltosoma  ;  the  cephalic  organs  should  be  investigated 
in  them  to  decide  whether  the  family  belongs  to  the  Culicidse  or  the 
Tipulidas ;  the  former  appears  the  more  probable,  and  they  much 
resemble  the  Simulidae.  The  larvae  of  Paltosoma  are  woodlouse- 
shaped,  with  deep  segmental  joints ;  the  lower  side  carries  a  series  of 
suckers  and  tracheal  gills  in  the  middle  line. 

Tracheal  System  of  Larval  Libellulidse.f  —  Eeferring  to  Dr. 
Palmen's  work  upon  this  subject.  Dr.  H.  Hagen  (pointing  out  that 
that  author  has  committed  some  errors  of  citation,  &c.)  follows 
Lyonnet  in  showing  that  the  stigmata  of  the  larvae  are  readily 
closed  in  case  of  necessity.  Thus  from  the  stigmata  of  a  living 
JEsc^na-larva,  impaled  with  a  pin  which  was  heated  in  a  flame,  a 
small  bubble  or  bladder  was  seen  protruded ;  dead  pinned  specimens 

*  '  Zool.  Anzeig.,'  ill.  (1880)  p.  134.  t  I^^id.,  p.  157. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  617 

sometimes  show  circles  of  dried  blood  round  the  stigmatic  opening. 
But  the  stigmata  which  are  thus  shown  to  open  under  certain  con- 
ditions can  hardly  be  closed  by  any  other  than  mechanical  means ; 
for  it  is  impossible  that  their  walls,  lined  as  they  are  by  a  continua- 
tion of  the  cuticle,  can  fuse  together  as  has  been  stated.  The  reason 
that  the  stigma  of  the  first  of  the  eight  abdominal  segments  is  so  often 
overlooked,  is  that  in  the  exuvium  its  tracheal  branch  lies  immediately 
under  the  longitudinal  cord,  composed  of  the  aggregated  tracheae ;  it 
is  smaller  in  the  imago  of  ^schna  constrida  than  in  the  larva. 

A  muscular  apparatus,  at  any  rate  in  the  second  and  the  other 
posterior  segments  of  the  larvae,  passes  backwards  and  upwards  from 
the  stigma  in  a  groove  to  the  internal  angle  of  the  segment.  The 
prothoracic  stigmata  differ  from  those  of  the  abdomen  in  having 
the  appearance  of  an  actively  used  apparatus  ;  a  number  of  large  well- 
developed  tracheae  pass  directly  to  the  stigma,  within  the  two  lips  of 
which  their  openings — covered  by  a  membrane  containing  a  dense 
reticulum  of  quadrangular  cells,  as  in  the  Perlidae — are  readily  to  be 
seen ;  the  commencement  of  the  spiral  thread  in  the  form  of  folds. 
The  mesothoracic  stigma  is  closed  by  a  plate  which  is  externally 
clothed  with  hair ;  in  the  larva  this  plate  carries  epidermis  as 
well,  and  constitutes  the  "  tympanum "  of  Oustalet ;  the  tracheae 
appear  to  be  functionally  active  here  also,  though  less  so  than  in  the 
prothoracic.  The  tissues  of  the  tracheal  brancheae  of  the  rectum  are 
cast  ofi'  in  Ejjitheca  bimaculata  and  prince'ps,  and  not  renewed  in  the 
imago — they  are  5  *  5  mm.  long  in  this  genus ;  the  same  seems  to  hold 
with  other  genera,  though  it  is  the  exception  in  ^sclina. 

Although  it  has  been  contradicted,  the  respiration  in  the  larvae  of 
Calopteryginae  is  conducted  by  a  tracheal  system  distributed  in  three 
rings  which  surround  the  rectum.  The  middle  foliar  gill  is  supplied 
by  tracheae.  Euphcea  manifests  a  still  higher  development  in  the 
possession  of  long  conical  organs  on  both  sides,  like  those  of  Sialis, 
seen  in  E,  sjAendens  and  a  species  from  Ceylon.  In  some  larvae 
(probably  belonging  to  a  new  species,  to  be  called  Aniso'ptertjx  comes, 
from  the  Himalaya),  a  long  pointed  cone  of  cuticular  structure  extends 
along  each  side  of  the  body  from  the  second  to  the  eighth  segment ;  the 
caudal  branchiae  are  inflated  and  pointed,  each  inflated  mass  contains 
a  fat  body  externally  pigmented  and  supplied  richly  with  tracheae 
internally ;  a  tube  of  similar  dark  colour  and  structure  extends  into 
the  lateral  respiratory  cone.  On  the  front  edge  of  the  eighth  external 
plate  in  Ejritheca  and  Libcllnla  occurs  an  oblique  slit  "5  mm.  long, 
leading  into  a  sac  in  the  body  which  is  loosely  enveloped  by  another 
sac  of  the  shape  of  a  Phrygian  cap,  and  •  5  mm.  long  by  •  5  mm.  broad, 
the  inner  one  being  covered  with  pavcment-ei^ithclium  ;  outside  this  iu 
the  articulation  fold  of  the  segment  is  an  area  covered  with  similar 
cells ;  the  external  loose  sac,  like  the  ci)idermis  of  a  large  traclical 
stem,  shows  rows  of  fine  granules  imdcr  a  high  power.  Tracliero  wcro 
traced  to  the  slit  or  opening.  This  apparatus  lias  not  been  found  iu 
the  Agrionidao.  It  may  possibly  secrete  a  lubricating  substance  for 
the  joints,  and  pcrliaps  is  connected  morphidogically  with  the 
abdominal  appendages,  which  are  present  in  Euphiva. 


618     RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

Remains  of  Branchiae  in  a  Libellulid :  Smooth  Muscle-Fibres 

in  Insects.* — Not  only  has  the  larva  of  Eiiphcea — as  described  f  by 
Dr.  Hagen  already-^lateral  branchife,  but  even  the  imago  has  them. 
Tbey  occur  as  small  cuticular  processes  on  the  ventral  face  of  every 
segment ;  on  the  second  segment  they  are  longer  and  almost  free ;  in 
the  male  they  lie  beside  the  genital  hooks.  Dr.  Palmen's  assertion  to 
this  effect  is  thus  justified.  Gills  do  not  occur  in  the  larvte  of 
Mliinocy^ha ;  but  they  occur  below  the  head  in  the  Perlid  Dictyopteryx 
signata. 

A  further  exception  to  the  conditions  obtaining  in  its  congeners  is 
offered  by  Euplicea,  in  the  presence  of  numerous  smooth,  unstripcd 
muscle-fibres  in  its  caudal  gills ;  these  gills  have  somewhat  the  shape 
of  a  turnip,  and  are  entirely  filled  with  a  pulpy  mass  consisting  of  a 
regular  network  of  sub-hexagonal  connective-tissue  cells ;  they  contain 
fat,  and  each  is  penetrated  by  two  stout  red  tracheal  vessels.  In 
longitudinal  section  they  exhibit  a  great  number  of  smooth  cross  fibres, 
and  also  a  series  at  right  angles  to  these.  The  fibres  are  arranged 
thus  in  the  gill,  which  has  a  circular  outline  with  the  exception  of  the 
lower  side  which  forms  a  right  angle  ;  from  the  apex  of  this  angle  pro- 
ceeds a  broad  bundle,  of  which  the  fibres  are  somewhat  distinct,  right 
and  left  into  the  gill ;  at  its  middle  the  fibres  are  much  concentrated ; 
the  upper  two-thirds  of  the  gill-cavity  are  devoid  of  muscles ;  a  number 
of  smaller  muscles  occur  in  the  lower  third  with  the  large  ones.  The 
only  indication  of  striation  in  any  of  these  fibres  under  an  immersion 
power  of  upwards  of  700  diameters  was  a  fine  longitudinal  lineation 
near  the  point  of  insertion.  The  physiological  action  must  be  that 
these  muscles  by  contracting  compress  the  two  large  tracheal  vessels 
which  lie  nearly  in  the  centre  of  each,  and  drive  the  oxygenated  air 
from  the  gill  into  the  body,  thus  meeting  the  want  of  a  free  circulation 
of  blood  in  the  part,  which  is  due  to  its  being  filled  up  with  other 
tissues ;  the  elasticity  of  the  connective  tissue  would  cause  the  mass 
to  re-expand. 

A  cellular  network  of  such  regularity  as  that  of  this  tissue  ap- 
pears never  to  have  been  recorded  from  the  body  of  an  insect 
before.  The  cells  measure  about  •  08  mm.  in  diameter,  and  their  wall 
less  than  •  0001  mm.  in  thickness.  The  longitudinal  striation  of  the 
proximal  end  of  the  muscles  must  be  due  to  a  series  of  folds  allowing 
of  expansion  after  the  air  has  been  driven  into  the  body. 

Probably  similar  arrangements  will  be  found  in  other  Calop- 
teryginfe. 

Metamorphosis  of  Prosopistoma.|  —  In  August  1878,  M.  A. 
Vayssiere,  in  conjunction  with  Dr.  E.  Joly,  published  a  note  on  the 
organization  of  Prosopistoma.  Notwithstanding  the  large  number  of 
living  individuals  they  then  had  at  their  disposal,  they  were  imable 
to  observe  any  transformation  in  these  curious  insects,  and  conse- 
quently were  led  to  accept  the  view  of  Mr.  MacLachlan,  that  Proso- 
pistoma  is  merely  an  Ephemerid  adapted  for  a'  permanent  aquatic 

*  '  Zool.  Auzeig.,'  iii.  (18S0)  p.  304.  t  See  ante,  p.  617. 

t  '  Comptes  Rcudus,'  xc.  (1880)  p.  1370. 


INVERTEBRATA,    CRYPTOaAMIA,    MICROSCOPY,   ETC.  619 

life.  Their  anatomical  observations,  especially  those  as  to  the  con- 
siderable concentration  of  the  nervous  system,  seemed  to  confirm  that 
hypothesis. 

M.  Vayssiere  considers  that  this  opinion  must  now  be  abandoned, 
as  he  has  just  seen  the  metamorphosis  of  two  of  the  insects  captui-ed 
in  April  last. 

The  following  are  the  principal  phases  of  this  metamorphosis : — 
Towards  the  end  of  May  the  amber-yellow  colour  of  some  of  the 
insects  became  darker  ;  and  owing  to  their  transparency  he  was  soon 
able  to  see  the  first  outlines  of  the  new  individual,  and  two  or  three 
days  afterwards  the  animal  cast  off  its  pujial  envelope,  freeing  itself 
in  the  same  manner  as  the  ordinary  Ephemeridfe, 

In  the  perfect  state  Prosoiyistoma  almost  exactly  resembles  Ccenis  ; 
its  last  segment  is  provided  with  three  rudimentary  bristles  represent- 
ing the  swimming  bristles  it  possessed  during  its  aquatic  state.  The 
anatomical  modifications  brought  about  by  this  metamorphosis  are 
reserved  for  a  complete  monograph  on  the  genus. 

Piercing  Organ  of  the  Lepidopteran  Proboscis.* — This  organ, 
which  has  already  been  described  t  by  the  author,  Professor  W.  Brei- 
tenbach,  is  situated  at  the  end  of  the  proboscis,  and  is  designated  by 
him  "  liquid-piercer,"  or  "  opotrype,"  and  its  function  is  now  con- 
sidered. There  are  various  forms  which  it  assumes,  but  they  all  result 
from  the  modification  of  simple  hairs.  Although  a  tactile  function 
has  not  been  satisfactorily  demonstrated  for  the  hairs  of  the  proboscis 
by  evidence  of  nervous  end-organs  in  them,  yet  analogy  and  their 
large  size  lead  to  such  an  inference.  Turning  to  those  more  complex 
appendages  to  the  proboscis,  the  barbed  hooks,  we  find  that  those 
butterflies  which  possess  them — as  0]:)lnderes  and  Egyholia — live  to  a 
great  extent  by  the  juice  extracted  from  the  interior  of  fruits,  a  process 
effected  by  the  intrusion  of  the  stout  trunk  into  the  rind  and  its  subse- 
quent withdrawal,  when  the  backwardly  directed  hooks  lacerate  the 
tissues  and  set  free  a  quantity  of  juice.  Direct  observation  of  a  similar 
function  in  the  "  liquid-piercer  "  is  not  forthcoming ;  this  fixct,  liow- 
cver,  speaks  in  its  favour,  namely  that  on  the  Alps  a  number  of  butter- 
flies are  seen  to  be  occupied  with  flowers  which  contain  no  lioney, 
thrusting  the  trunk  into  them  and  remaining  tluis  employed  for  a 
time ;  if  this  process  was  really  futile,  it  would  soon  cease  to  bo 
repeated;  but  as  it  is  not,  it  is  probable  that  liquid  is  procured  by  tlio 
laceration  of  the  structures  by  the  piercer.  The  structure  of  the  organ 
itself  supports  this  assmnption ;  the  median  point  of  that  of  Vaiwssa 
is  admirably  adapted  to  pierce  the  delicate  membrane  of  a  juicy  cell, 
and  the  lateral  points  to  break  up  more  cells,  so  that  where  as  many 
as  sixty  piercers  are  i)resent,  as  in  V.  canhii,  the  eficct  would  be  very 
great,  but  only  analogous  to  that  already  known  to  be  produced  by 
the  maxilljo  of  the  humble-bees. 

In  ojqiosition  to  this  view  stands  Fritz  Miillcr's  opinion  that  they 
arc  "  taste-rods  "  ;    but  to  this  it  is  re^jlied  that  their  structure  is 

•  'Eiitomol.  Nucbrichleii,'  vi.  (18S0)  p.  29. 
t  See  this  Jouruul,  ii.  (IS?*.))  p.  41. 


620  RECOKD   OF   CURRENT   RESEARCBTES   RELATING   TO 

cuticular,  not  cellular,  and  that  they  probably  contain  no  living 
protoplasm  through  which  sensations  of  taste  could  be  transmitted ; 
further,  the  characteristic  "  taste-cells  "  are  wanting  ;  and  this  hypo- 
thesis fails  to  explain  the  presence  of  the  teeth  and  radial  plates. 
Tactile  organs,  however,  as  is  the  case  with  the  hairs  fx'om  which  they 
are  derived,  they  might  in  part  be,  transmitting  to  the  insect  infor- 
mation as  to  the  absence  or  presence  of  free  honey  in  any  calyx  which 
is  investigated. 

Generative  Glands  and  Sexual  Products  in  Bombyx  mori.* — 
A.  Tichomirow  has  made  out  a  distinct  central  orifice  in  the 
epithelial  septum  which  divides  the  ovarian  ovum  from  the  yolk- 
chamber;  through  this  a  granular  substance  resembling  that  of  the 
■yolk-forming  cells  is  seen  to  pour  into  the  yolk.  The  chambers  in 
which  the  eggs  are  found  after  leaving  the  yolk-forming  cells  are 
clothed  all  over  by  closely  packed  epithelial  cells  between  which  no 
spaces  occur.  Sections  show  that  the  epithelium  of  the  yolk-chambers 
grows  thinner  as  the  cells  lining  the  "  egg-chambers  "  grow  vertically 
thicker,  these  latter  form  the  chorion,  each  contributing  a  small  plate 
to  it ;  in  far  advanced  chambers  these  plates  form  a  continuous 
cuticle. 

The  terminal  spaces  of  the  ovarian  tubes  are  filled  with  cells, 
those  near  the  external  membrane  small,  ultimately  becoming  the 
epithelium  of  the  tube,  the  more  central  ones  are  successively  larger 
and  become  ova  and  yolk-forming  cells.  Free  nuclei  occur  in  the 
very  last  chamber,  becoming  the  nuclei  of  the  epithelium.  The  ovum 
and  the  yolk-cells  both  increase  in  size,  but  the  former  the  quickest 
and  chiefly  at  the  expense  of  the  latter.  The  testes  consist  of  two 
sacs  penetrated  by  largely  branched  tracheae ;  they  contain  large 
numbers  of  smaller  follicles  which  vary  immensely  in  their  shape  and 
the  nature  of  their  contents  from  the  youngest,  which  are  spherical,  to 
pear-shaped,  and  finally  to  very  elongated  forms  ;  in  them  all,  until  the 
spermatozoa  are  mature,  a  fragile  tunica  propria  is  discernible.  The 
testis  is  enveloped  at  the  proximal  end  by  a  fine  connective  tissue 
containing  fat-cells ;  at  the  free  end  the  youngest  follicles  occur, 
further  down  riper  ones  are  found,  and  finally  bunches  and  single 
specimens  of  spermatozoids.  The  penetration  of  the  tracheae  into 
the  cavity  shows  that  it  cannot  be  lined  internally  by  an  epithelium. 
In  a  comparison  of  the  structures  of  the  male  and  female  glands,  the  wall 
of  the  testis  corresponds  to  the  common  envelope  of  the  ovarian  tube, 
but  the  ovarian  tubes  are  represented  by  nothing  in  the  testes ;  the 
follicles  in  the  latter  represent  the  egg-chambers.  The  follicles  with 
their  contained  spermatoblasts  are  to  be  regarded  as  only  a  part  of 
the  contents  of  the  gland ;  the  latter  commence  as  round  cells  pro- 
vided with  a  nucleus  and  nucleolus,  the  outline  of  the  nucleus 
disappears  suddenly  and  a  strongly  refringent  body  appears  near  it ; 
the  nucleolus  persists  when  the  cell  has  taken  the  form  of  an 
elongated  fibre  ;  the  subsequent  formation  of  sj)ermatozoa  follows  the 
process  described  by  Biitschli. 

*  'Zool.  Anzeig.;  iii.  (18S0)  p.  235. 


INVERTEBKATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  621 

Development  of  Forficula.* — L.  Camerano  has  found  the  eggs  of 
Forficula  auricularia  Linn,  at  the  end  of  January ;  a  female  was 
found  with  them.  This  conflicts  with  Fischer's  statement  that  the 
eggs  are  laid  in  April,  but  the  case  was  but  a  single  one,  and  the  pre- 
ceding fine  autumn  may  have  advanced  the  time  of  oviposition.  On 
the  eggs  being  scattered  about,  the  female  carried  them  in  her 
mandibles  to  one  place  so  as  to  re-form  the  original  heap ;  her  move- 
ments were  less  active  when  under  a  good  light  than  otherwise.  The 
egg  is  ellipsoidal,  yellowish  white,  and  somewhat  opaque,  about  1  mm. 
in  extreme  diameter.  In  the  ova  gathered  in  January  the  embryos  were 
to  be  seen,  with  brownish  eyes,  mandibles,  eight-jointed  antennae,  and 
the  posterior  pincers,  prothorax,  and  abdominal  rings  superficially 
punctate;  the  antennee,  palps,  and  legs  were  invested  by  a  pellicle, 
which  appears  not  to  be  the  future  larval  skin.  At  the  end  of  six  days 
from  the  finding  of  the  eggs  the  young  began  to  come  out  (but  perhaps 
unduly  early  owing  to  the  warmth  of  the  rooms).  At  this  stage  they 
are  whitish  in  colour,  have  weak  legs,  but  well-developed  and  motile 
pincers  ;  after  six  or  seven  hours  the  body  begins  to  assume  its  brown 
colour,  beginning  with  the  pincers  ;  the  legs  and  lower  parts  become 
coloured  later.  Owing  to  absorption  of  air  the  body  rapidly  increases 
in  size,  and  at  the  end  of  ten  hours  from  leaving  the  egg  is  3  mm. 
long,  excluding  the  pincers.  Three  changes  of  skin  take  place ; 
possibly  a  fourth,  anterior  to  the  first  observed,  may  have  escaped 
notice,  owing  to  the  habit  which  the  larva  has  of  devouring  the  old 
skin  at  once.  The  first  of  these  changes  occurs  when  the  larva  is 
about  6  mm.  long  (excluding  pincers),  the  second  at  8  mm.,  the  third 
at  12  mm. 

In  another  instance  eggs  were  laid  on  March  10th  by  a  female 
taken  in  the  winter,  and  the  larvsa  from  them  made  their  first  change 
of  skin  between  March  24th  and  the  30th  ;  the  second  change  took 
place  on  the  15th  of  April,  the  third  at  the  beginning  of  May,  and  on 
May  22nd  the  larva3  became  perfect  insects.  It  was  noticed  that  some 
males  of  this  species  appeared  to  prefer  dead  insects  to  fruit  as  food. 

Actora  sestuum  from  the  Shore  at  Heligoland.f — This  insect, 
described  by  Meigen,  justifies  its  name  by  the  locality,  namely  the 
surf  of  the  sea,  or  the  seaweed  floating  near  the  shore,  in  which  it  is 
found.  Dr.  Joseph  observes  tliat  it  is  very  timid,  flying  oft'  to 
another  part  of  the  wet  sand  at  the  slightest  noise ;  it  may  bo 
covered  by  a  wave  but  it  shortly  reappears  on  the  surface,  the  drops 
rolling  from  it  as  from  a  sea-bird.  This  fact  is  due  to  a  somewhat 
glistening  waxy  covering  (which  splits  and  falls  away  in  the  form  of 
minute  scales  from  time  to  time)  being  then  renewed ;  most  rapidly 
so  on  the  wings,  halteres,  and  spiracles.  It  is  produced  as  a  primarily 
oily  substance  by  small  glands  scattered  over  the  body,  aided  by 
larger  tubular  ones,  resembling  the  sweat-glands  of  some  mammals, 
and  lying  in  the  connective  tissue  between  tlie  wing-muscles ;  their 
ducts  open  beneath  the  commencements  of  the  wings  and  halteres. 

*  '  Rnll.  S.)c.  Entomr.l.  Hal.,'  xii.  (1880)  p.  46. 
t  '  Zool.  Anzcig.,'  iii.  (1880)  p.  250. 


622  EECOKD   OF   CURKENT  RESEARCHES   RELATING   TO 

The  larva  resembles  tliat  of  the  common  Scatophaga  stercoraria  L., 
but  is  larger;  it  lives  in  the  bladclerwrack  between  high  and  low- 
water  mark,  the  periodical  wetting  with  sea-water  being  necessary,  as 
shown  by  experiments,  to  its  existence.  The  pupte  are  found  from 
2  to  3  inches  deep  in  the  sand ;  the  imago  emerges  in  from  fourteen 
to  eighteen  days. 

A  hymenopterous  parasite,  resembling  Smicra  clavipes,  was  observed 
to  issue  from  the  pupa  in  one  case ;  the  egg  must  have  been  laid  by 
the  female  of  that  species,  which  is  abundant,  between  the  time  that 
the  larva  left  the  weed  and  that  at  which  it  entered  the  sand.  The 
parasite  devours  the  entire  interior  of  the  pupa,  and  emerges  in 
eighteen  days. 

Destruction  of  Noxious  Insects  by  Mould.* — In  answering  Pro- 
fessor Metschnikoff's  remarks  on  Dr.  Bail's  discovery  of  the  deadly 
action  of  mould  on  insects,  Dr.  Hagen  remarks  that  that  observer 
never  applied  his  method  to  noxious  insects,  altliough  he  was  suc- 
cessful with  other  kinds.  He  himself  has  found  that  potato-beetles 
took  the  disease  thus  engendered,  and  died  in  from  eight  to  twelve 
days ;  the  other  half  of  the  same  lot  of  beetles,  which  were  not 
inoculated,  lived  through  the  winter  in  the  same  room.  He  has  also 
killed  plant-lice  in  a  hothouse  by  this  means.  He  cannot  agree  with 
Professor  Metschnikoff  that  the  discovery  cannot  be  applied  to  prac- 
tical r.ses  until  its  scientific  meaning  is  understood,  for  the  results 
already  show  that  it  is  successful  in  practice,  and  its  success  is  being 
further  tested  by  the  experiments  of  many  naturalists. 

y.  Arachnida. 

Development  of  the  Araneina.t — That  Mr.  Balfour's  "  notes  "  on 
this  subject  were  really  wanted  is  shown  by  the  extremely  scanty  list 
of  writers  who  have  addressed  themselves  to  the  spiders,  or  to  allied 
forms ;  tiie  investigations  now  under  consideration  were  made  on 
the  ova  of  Agelena  labyrinthica.  The  embryos  were,  after  the  method 
of  Bobretsky,  hardened  in  bichromate  of  potash,  after  having  been  for 
a  short  time  in  nearly  boiling  water.  "  They  were  stained  as  a 
whole  with  hfematoxylin  after  the  removal  of  the  membranes,  and 
embedded  for  cutting  in  coagulated  albumen." 

Segmentation  of  the  Ovum. — When  segmentation  is  complete,  the 
embryo  is  found  to  consist  of  a  single  layer  of  large  flattened  cells,  ■ 
with  a  central  mass  of  yolk-segments,  polygonal  in  form  and  made  up  of 
a  number  of  clear  yolk-spherules ;  among  these  yolk-segments  we  find 
bodies  which  consist  of  a  large  nucleus,  filled  with  aj^parent  nucleoli, 
and  of  a  surrounding  layer  of  protoplasm:  each  nucleated  body 
would  seem  to  belong  to  a  yolk-s])here,  and  to  be  placed  at  one  side 
of  it ;  the  nuclei  themselves  would  be  derived  from  the  nuclei  of  the 
"  segmentation  rosettes." 

In  the  next  stage,  which  is  not  far  from  that  of  the  completed 
segmentation,  the  ventral  surface  of  the  embryo  is  distinctly  marked  ; 
it  would  appear  to  be  made  up  of  a  procephalic  lobe,  an  intermediate 

*  '  Zool.  Auzclg.,'  iii.  (18S0)  p.  185. 

t  '  Quart.  Journ.  Micr,  Sci.,'  xx.  (1830)  p.  1G7. 


INVERTEBRATA,    CRYPTOGAMIA,   MICROSCOPY,   ETC.  623 

portion,  and.  a  caudal  lobe ;  the  ventral  thickening  is  important, 
inasmuch  as  it  is  the  point  at  which  two  rows  of  cells  are  tirst 
developed,  and  is  therefore  the  first  indication  of  the  future  mesoderm. 
The  already  mentioned  intermediate  portion  consists  of  three  indis- 
tinct segments ;  the  first  of  these  appears  to  be  the  seat  of  origin  of 
the  first  pair  of  ambulatory  limbs.  The  character  of  the  ventral 
thickening  is  to  be  noted ;  first,  because  it  shows  that  in  this  form, 
at  any  rate,  the  cells  are  continuous  across  the  middle  line,  and  do 
not  exhibit  any  bilateral  arrangement ;  and  secondly,  because  it  is 
very  similar  to  the  arrangement  described  by  Kowalevsky  as  obtain- 
ing in  an  insect,  and  is  sujiported  by  the  observations  of  Barrois,  who 
has  already  noted  the  presence  of  "  a  continuous  ventral  plate  of 
mesoblast." 

Shortly  after  this  stage,  there  is  found  one  in  which  there  are  six 
segments  intermediate  between  the  procephalic  and  caudal  lobes ;  the 
first  two  are  more  indistinct  than  the  succeeding  ones,  owing  pro- 
bably to  their  later  formation.  The  increase  in  segments  is  regular, 
and  each  new  one  appears  between  the  one  last  formed  and  the 
caudal  lobe ;  the  appendages  do  not  begin  to  appear  until  some  nine 
or  ten  segments  have  been  formed,  and  there  is,  at  this  period  a 
distinct  median  ventral  groove ;  at  this  stage  the  procephalic  region 
is  "  distinctly  bilobed,"  but  the  first  segment  is  still  without  append- 
ages ("  chelicerjB  ") ;  this  is  in  keeping  with  its  late  appearance  as  a 
segment.  Some  of  the  succeeding  appendages  are  indicated  by 
swellings.  An  imperfect,  though  distinct,  division  of  the  mesoblast 
into  somites  is  now  api^arent. 

In  the  next  stage  the  ventral  plate  extends  over  nearly  the  whole 
circumference  of  the  ovum,  the  procephalic  region  is  distinctly  bilobed, 
the  stomodoeum  is  commencing,  each  of  the  six  segments  behind  the 
lobe  bears  prominent  appendages;  and  behind  these  there  are  four 
somites  with  small  protuberances.  The  latter  are  provisional  ap- 
pendages, and  their  presence  has  been  already  noted  by  Clajjarede  and 
Barrois.  Just  a  little  later,  sixteen  post-cej)halic  segments  may  bo 
detected. 

The  cpiblast  exhibits  no  less  interesting  characters ;  it  is  very  thin 
along  the  median  groove,  but  on  either  side  there  is  well-marked 
thickening  forming  the  first  rudiments  of  the  ventral  ncrvc-ganglia. 
It  is  of  importance  to  note  that  tlio  clielicera)  have  a  ganglionic- 
thickening  independent  of  the  procephalic  lobes.  In  these  latter  tho 
cpiblast  is  much  thickened,  but  this  is  tho  part  which  goes  to  form 
the  supra-cesophagcal  ganglia. 

Later  on,  the  appendages  begin  to  be  jointed,  and  primitively 
these  joints  are  five  in  number ;  this  is,  as  Mr.  Balfour  points  out,  an 
interesting  character,  for  "  this  number  is  permanent  in  Insects  and 
in  Pcripatus." 

Next,  we  find  that  tho  limbs  nearly  meet  in  the  middle  lino ;  tho 
two-jointed  cheliccrfc  ajipear  to  teruiiuate  in  rudimentary  chclic, 
and,  so  far,  indicate  that  the  spiders  had  anccstdrs  with  chelate 
chelicorro.  A  largo  upi)er  and  n  small  lower  lip  have  bocomo 
diveldind  at  the  entrance  to  the  stoiiiodiiim ;  the  priv'cphalic  lobes 


624  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

are  distinct,  and  are  divided  by  a  groove  into  a  narrower  anterior  and 
a  broader  posterior  portion.  What  is  of  considerable  value  is  the 
observation  that  a  section  of  the  body-cavity  is  enclosed  between  the 
splanchnic  and  somatic  layers  of  the  mesoblast  of  these  lobes. 
Connecting  this  with  the  observations  of  Kleinenberg  on  Lumhricus, 
the  author  points  out  that  the  procephalic  lobe  of  the  spider  repre- 
sents the  prfe-oral  lobe  of  the  Chtetopod  larva  ;  "  but  the  prolongation 
of  the  body-cavity  into  it  does  not  necessarily  imply  that  it  is  equivalent 
to  a  post-oral  segment."  There  is  not  yet  any  trace  of  the  separation  of 
the  ganglionic  portion  of  the  epiblast  of  the  lobes  from  the  epidermis. 

As  the  embryo  takes  on  the  characters  of  the  adult,  the  hitherto 
simple  dorsal  region  begins  to  be  developed,  so  that  there  soon 
appears  a  ventral  instead  of  a  dorsal  flexure  of  the  embryo.  After  a 
time  the  heart  becomes  evident,  taking  its  origin  from  a  solid  cord  of 
cells,  which  are  derived  from  the  dorsal  mesoblast  prior  to  the 
diiferentiation  of  two  strata  in  this  region.  About  the  same  time  the 
thickenings  of  the  supra-oesophageal  ganglia  become  separated  from 
the  epiblast,  and  the  proctodoeum  begins  to  appear. 

Other  points  of  interest  are  described,  but  our  space  requires  us  to 
pass  on  to  the  general  conclusions  ;  on  the  whole  the  history  of  develop- 
ment is  conclusive  as  to  the  closer  affinity  of  the  Arachnida  to  the 
Tracheata  than  to  the  Crustacea  (Branchiata).  The  mesoblast  has 
very  much  the  same  history,  being  in  both  cases  formed  by  a  thicken- 
ing of  the  median  line  of  the  ventral  streak :  in  the  Crustacea  the 
mesoblast  is  known  to  be  developed  from  the  walls  of  an  invagina- 
tion. Where  mesoblastic  somites  are  found  in  Crustacea  they  are  not 
similar  to  those  of  the  Tracheata.  The  mesenteron  of  the  Crustacea  is 
formed  by  an  invagination,  and  the  proctodoeum  appears  before  or  co- 
temporaneously  with  the  stomodoeum ;  the  reverse  obtains  with  the 
Tracheata,  where,  too,  the  mesenteron  is  not  excessively  short,  nor  the 
proctodoeum  very  long.  It  is  now  almost  completely  certain  that  the 
chelicera3  are  true  post-oral  appendages,  and  it  is  clear  that,  just  as  in 
Lumhricus  and  Peripatus,  there  is  no  invagination  of  epiblast  in  the 
region  of  the  ventral  nerve-cord. 

In  a  postscript  to  this  paper,  which  appears  on  p.  lOfi  of  the  new 
'  Studies  from  the  Morphological  Laboratory,  at  Cambridge,'  Mr. 
Balfour  states  that  his  attention  has  been  directed  to  the  German 
abstract  of  a  paper,  written  in  Eussian,  by  Salensky ;  from  this  he 
gathers  that  that  observer  has  detected  the  splitting  of  the  mesoblast 
into  splanchnic  and  somatic  layers,  and  had  given  a  very  similar 
accoimt  of  the  development  of  the  heart.  With  regard  to  the  pro- 
visional abdominal  appendages,  the  final  stages  of  which  Mr.  Balfour 
was  unable  to  observe,  Salensky  found  that  the  anterior  pair  gave 
rise  to  the  pulmonary  sacs,  while  he  thought  that  the  third  and 
fourth  pairs  became  the  spinning  mamillas ;  the  latter  view,  at  any 
rate,  the  English  observer  is  inclined  to  reject. 

Peculiar  Modification  of  a  Parasitic  Acarian.*  —  Amongst  a 
large  niunber  of  insects  parasitic  on  plants,  the  female  ready  to  lay 

*  'Comptcs  Eendus,'  xc.  (1880)  p.  1371. 


INVERTEBBATA,   CRYPTOGAMIA,    MICROSCOPY,   ETC.  625 

or  to  give  birth  to  larvae  often  covers  herself  with  a  cottony  or  byssoid 
secretion,  which  serves  not  only  to  protect  herself,  but  also  to  pre- 
serve the  young  during  the  early  periods  of  life.  Certain  Arachnids, 
also  parasitic  on  plants,  have  the  same  power  ;  and  a  species  of 
Tetranychus  has  for  that  reason  been  named  T.  telarius.  In  this  case 
the  cottony  secretion  constitutes  a  true  nidification  destined  to  protect 
the  eggs,  as  the  female  lays  successively  in  several  nests. 

Hitherto  nothing  similar  had  been  observed  amongst  the  Acarians 
parasitic  on  animals  ;  but  M.  Megnin  has  now  found  by  accident  an 
exactly  similar  fact  in  the  parasite  of  a  bird.  In  dissecting  an 
American  Grosbeak  he  was  struck  by  the  presence  of  numerous  white 
spots  strewn  over  the  naked  median  and  sternal  portion  of  the  skin 
covering  the  lower  surface  of  the  breast.  Viewed  with  a  lens  they 
appeared  like  spots  of  mould ;  but  under  the  Microscope,  especially 
after  soaking  them  in  glycerine,  which  rendered  them  diaphanous, 
these  spots  proved  to  consist  of  a  fine  tissue,  under  which  appeared 
a  group  of  eggs  in  different  stages  of  incubation,  of  empty  egg- 
shells, and  of  small  yellow  Acarians  just  hatched.  These  Acarians 
are  but  octopodal  larvse,  which  it  is  easy  to  recognize  by  the  anatomical 
characters  of  their  rostrum  and  legs  as  belonging  to  the  species  named 
by  the  author  Cheyletus  lieteropalpus* 

Professor  Ch.  Eobin  f  has  shown  that  the  plumicolous  Sarcoptides 
lay  their  eggs  in  small  masses  at  the  axils  of  the  barbs  of  the  feathers ; 
and  M.  Megnin  thought  that  his  parasitic  Cheyletidae  did  the  same, 
though  he  had  never  found  their  eggs  together. 

The  foregoing  observations  show  how  these  eggs,  which  are  very 
large  ('IS  mm.  x  '11  mm.),  are  laid,  and  what  precautions  the 
animals  take  to  protect  them,  a  fact  which  brings  them  singularly 
near  the  Tetranychi,  with  which  they  are  besides  so  closely  allied 
in  organization ;  they  show,  moreover,  that  the  larvae  of  this  species 
are  octopod  at  birth,  a  character  not  possessed  by  those  of  the 
Tetranychi,  nor  even  by  those  of  the  wandering  Chcyletides,  such  as 
Cheyletus  eruditus. 

Structure  of  Trombidium.l — The  results  of  A.  Croncberg's  in- 
vestigations lead  him  to  believe  in  a  closer  connection  between  this 
genus  and  the  Hydrachnidai  than  would  apjicar  from  Pagenstecher's 
monograph  of  the  genus.  His  study  of  T.  holosenceum  shows  that  the 
cuticle  consists  of  an  external  layer,  traversed  by  pores  and  carrying 
the  hairs,  and  of  a  thin  fenestrated  inner  layer.  The  hypodormis  is 
granular,  semi-fluid  in  life ;  no  cell-structure  can  be  discovered  in  it. 

Dlijedive  Organs. — The  labium  presents  a  deep  groove,  open  in 
front.  Posteriorly,  its  halves  are  united  by  a  cross-piece,  from  each 
side  of  which  a  narrow  piece  runs  backwards  along  the  uppi:r  edge  of 
the  maxilla,  representing  the-"  supra-cesophagcal  ridges  "  of ////(/ntc'/jmi 
glohosa.  Closely  connected  with  the  ci'oss-picco  arc  two  chitinous 
tubes,  which  jiroject  backwards  and  enclose  the  posterior  three-iniartcrs 
of  the  two  great  tracheal  vessels,  the  anterior  part  of  these  being  left, 

*  '  Joiirn.  Aniit.  ct  I'livsiol.'  (Uoliin),  1878. 

t  '  ("c.iiiptu.s  llLMi.his,'  Apr.  :!(),  ISCS. 

X  'liiill.  S.m;.  Iinp.  Nat.  Mascow,'  liv   (187!t)  i-  2[H 
VOL.    III.  2    T 


G26  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

as  also  in  the  Hydraclinidae,  uncovered  by  the  tubes.  These  structures 
are  represented  in  Eijlais  by  two  long  rods,  which  enclose  the  tracheae 
for  a  short  distance.  Two  ridges  projecting  forwards  from  the  cross- 
piece  enclose  the  mouth,  as  in  Hydrachna ;  behind  this  the  pharynx, 
which  consists  of  a  chitinous  groove  roofed  in  above  by  a  lamina  of 
intrinsic  and  extrinsic  muscles,  passes  backwards  within  the  labium, 
exactly  as  in  Hydrachna.  An  oesophagus  of  the  same  diameter 
(O*  25  mm.)  traverses  the  main  nervous  mass,  after  rising  up  ;  it  enters 
the  lower  part  of  the  anterior  end  of  the  stomach,  thus  differing  from 
Pagenstecher's  description,  but  agreeing  with  Hydrachna  again.  The 
stomach's  upper  surface  presents  symmetrically  arranged  lobes,  through 
the  spaces  between  which  the  vertical  body-muscles  pass ;  the  excretory 
organ,  which  has  been  called  a  fat  body,  can  be  just  seen  in  the  median 
line.  The  cfecal  lobes  consist  of  a  memhrana  propria,  lined  internally 
by  a  thick  granular  layer  containing  granular  vesicles,  but  no  trace  of 
cell-structure.  A  similar  structure  characterizes  the  stomach-walls, 
so  that  Pagenstecher's  description  of  cells  here,  and  his  consequent  in- 
terpretation of  the  organ  as  a  liver,  prove  erroneous.  Probably  it  has 
a  double  function,  the  biliary  secretion  being  supplied  by  the  brown 
cells  and  the  granular  investing  substance,  in  Hydrachnidae.  Possibly 
the  non-cellular  mass  of  Trombidium  represents  a  stage  in  the  break- 
ing down  of  these  liver  cells.  There  is  no  direct  connection  between 
the  stomach  and  anus.  The  posterior  end  of  the  excretory  organ, 
which  has  been  mistaken  for  such  a  connection,  is  distinguishable  by 
its  chalky-white  contents  ;  it  has  two  anterior  branches,  and  contracts 
posteriorly  towards  the  anus ;  no  lining  ei)ithelium  was  made  out. 
The  buccal  glands  have  a  common  opening  into  the  mouth,  the  loop- 
shaped  gland  ending  in  a  narrow  canal  into  which  the  ducts  of  the 
rounded  glands  open. 

Nervous  System. — An  oval  mass  represents  the  brain  and  ventral 
ganglia ;  the  posterior  part  shows  signs  of  bilateral  symmetry.  A 
layer  of  small  cells  directly  underlies  the  neurilemma.  The  twelve 
pairs  of  nerves  are  divided  into  two  divisions,  one  directed  forwards, 
the  other  backwards ;  but  besides  these  there  is  an  anterior,  unpaired 
nerve,  also  found  in  Bhyneolophus,  which  overlies  the  oesophagus ;  the 
pair  next  behind  this  is  the  optic  pair-,  and  a  pair  lying  beneath  these 
probably  supplies  the  palps  ;  the  next  goes  to  the  maxillee  ;  two  stout 
pairs  following  these  supply  the  two  front  pairs  of  legs.  The  two 
nerves  of  the  fourth  pair  of  legs  are  but  branches  of  a  single  nerve. 

Generative  Organs.  —  Treviranus'  accoimt  of  these  parts  agrees 
much  better  than  Pagenstecher's  with  the  real  state  of  the  case.  The 
ovaries  are  connected  by  a  short  bridge  of  tissue  lying  above  the 
generative  opening ;  the  oviducts  are  directed  forwards,  and  a  circular 
arrangement  of  the  organs  round  the  oi^ening,  common  in  other 
Arachnida,  is  thus  presented.  The  number  of  eggs  in  the  ovary  is 
innumerable,  and  they  range  from  young  elongated  forms  of  •  05  mm. 
diam,,  with  distinct  germinal  vesicle  and  spot,  to  mature  individuals  of 
•15  mm.,  clouded  by  presence  of  yolk.  The  long  and  tortuous  ovi- 
ducts have  their  basal  portions  coiled  up  together;  their  median 
segments  arc  thickened  by  a  special  external  layer  of  cells,  •  06  mm. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  627 

in  diameter.  The  vagina  lias  strong  circular  muscles,  and  is  divided 
transversely  by  a  constriction  ;  the  only  accessory  organs  observed  are 
three  small  globose  vessels,  situated  on  each  side  of  the  vagina,  and 
consisting  of  a  distinct  membrane  apparently  with  a  cellular  epithe- 
lium. Of  the  male  organ  the  two  testes  form  the  chief  part,  and 
consist  of  plicated  tubes  with  their  walls,  and  contain  several 
chambers  lined  with  flat  polygonal  cells,  enclosing  a  mass  made  up  of 
small  nucleated  cells,  apparently  the  sperm-cells.  Two  short,  wide 
vasa  defereutia,  lined  by  circular  muscles,  underlie  the  testes.  The 
medially  placed  ductus  ejaculatorius,  of  similar  structure,  is  about 
twice  as  broad,  and  terminates  in  a  copulatory  apparatus  of  the  form 
of  a  bulb  witb  a  hollowed  chitiuous  ridge,  with  two  chitiuous  hoojis  at 
its  sides,  ending  in  a  sharp,  transparent,  barbed  point ;  the  muscles 
arc  transversely  arranged.  The  long,  narrow  accessory  glands  observed 
by  Treviranus  open  into  the  distal  end  of  the  ductus  ejaculatorius ; 
they  are  difficult  to  disentangle  from  the  surfiice  of  the  testes,  and 
are  lined  by  an  epithelium  of  roundish  or  cubical  cells  and  by  a  fine 
membraua  intima. 

5.  Crustacea. 

Central  Nervous  System  of  the  Crayfish.*  —  Herr  Krieger 
appears  to  have  a  very  high  opinion  of  the  usefulness  of  osmic  acid, 
which  he  ordinarily  applies  thus :  The  ganglia  having  been  removed 
from  the  crayfish,  are  placed  on  a  slide  over  the  mouth  of  a  wide- 
necked  flask  containing  the  acid.  After  having  been  thus  subjected 
to  its  vapour  they  are  removed  to  picrocarmine,  in  which  they  remain 
for  twelve  hours  ;  they  are  then  macerated  in  very  dilute  picrocar- 
mine, to  which  a  little  picric  acid  has  been  added.  This  treatment  is 
best  aelaptcd  for  the  demonstration  of  the  nuclei,  and  the  protoplasm 
of  the  ganglionic  cells.  After  entering  into  the  mode  of  investigation 
in  further  detail,  the  author  passes  to  the  descriptive  portion  of  his 
paper;  this  falls  under  two  heads:  (1)  Histological,  and  (2)  Topo- 
graphical. 

(1)  Commencing  with  an  account  of  tlie  ganglionic  cells  of  the 
central  nervous  system,  the  author  says  that  they  are  in  all  cases 
destitute  of  a  membrane,  are  more  or  less  sj^herical  or  pyrift)rm  in 
form,  and  provided  with  a  proportionately  largo  and  spherical  nucleus. 
The  following  forms  may  be  distinguished : — 

a.  Cells  with  distinct  protojilasm,  and  generally  with  a  number  of 
nucleoli  within  the  nucleus. 

b.  Small  cells  with  a  delicate  fringe  of  protoplasm,  which  is  most 
distinct  in  the  neighbourhood  of  the  process  given  off  from  the  cell. 

c.  Very  small  granular  elements,  with  processes ;  the  protoplasm 
is  evanescent ;  the  fine,  granulated,  cell-contents  are  highly  refractive, 
but  there  are  no  evident  nucleoli. 

Tlie  fibrous  elements  maybe  divided  into  those  which  belong  to  the 
ganglionic  processes,  to  tlie  fibres  of  the  transverse  or  of  the  longitu- 
dinal commissures,  or  to  the  perijiheral  nerve-fibres;  histologically, 
they  may  be  said  to  be  tubular  and  well  ilevelopeil,  or  fibrillar  and 

*  'Zcitsclir.  wis8.  Zonl.,'  xxxiii.  (18S0)  p.  r)27. 

2   T   2 


628      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

delicate.  The  author  finds  no  evidence  that  the  former  arc  compounds 
of  the  latter ;  and  in  this  he  is  supported  by  Hclmholtz,  Haeckel, 
and  Yung.  Two  of  the  fibres  of  the  longitudinal  commissures  are 
especially  distinguished  by  their  size ;  these  are  the  "  colossal " 
nerve-fibres.  Krieger  has  been  led  by  his  observations  to  regard  the 
bundle  of  fine  fibres  which  were  first  described  by  Eemak  as  placed 
in  these  to  be  merely  coagulation-products.  When  carefully  prepared, 
the  contents  of  the  colossal  fibres  may  be  seen  to  be  clear  and  homo- 
geneous, but  after  a  period  of  removal  from  the  body  delicate  striations 
appear,  and  gradually  become  more  distinct. 

Dotted  Substance. — Even  with  the  naked  eye,  in  the  fresh  con- 
dition, it  is  possible  to  see  in  the  ganglia  of  the  crayfish  whitish 
spheres  of  a  comparatively  considerable  size ;  when  these  are  examined 
under  the  Microscope,  they  are  seen  to  be  neither  ganglion-cells  nor 
fibrous  bundles,  but  rather  to  consist  of  a  finely  granulated  mass  ;  this 
dotted  substance  is  by  Krieger,  as  by  Leydig,  Dietl,  and  others, 
regarded  as  being  a  network  of  very  delicate  fibres.  The  true 
characters  of  the  body  may  be  demonstrated  by  two  difierent  methods. 
Of  these,  one  is  due  to  Dietl,  and  consists  in  making  fine  trans- 
verse sections  of  a  ganglion  which  has  been  hardened  in  "  osmium  "  ; 
the  other  method  is  thus  described :  A  portion  of  a  ganglion  is  placed 
for  several  days  in  a  0*1  per  cent,  solution  of  chromate  of  ammonia, 
is  then  teased  up  with  fine  needles,  and  placed  under  a  covering  glass 
in  the  same  fluid.  After  a  brief  description  of  the  connective  tissue, 
the  author  passes  to  (2)  The  Topographical  relations  of  the  Nervous 
System. 

Cerebrum. — When  we  examine  this  in  transverse  sections,  wo  first 
meet  with  the  two  optic  nerves ;  here,  two  kinds  of  fibres  can  be  easily 
distinguished,  one  of  which  is  much  more  delicate  than  the  other. 
The  fine  fibres  appear  to  decussate  completely,  and  not  to  form  a 
semi-decussation,  as  has  been  stated  by  Dietl.  In  the  anterior  enlarge- 
ments of  the  cerebrum  there  are  some  structures  which  are  not 
easily  comprehended ;  the  first  of  these  is  a  band  of  coarse  dotted 
substance,  which  intervenes  between  the  two  pairs  of  spheroidal 
bodies  which  are  placed  near  the  chiasma,  and  the  other  consists  of  a 
pair  of  rounded  bodies,  which  are  made  up  of  a  fine  dotted  substance 
placed  below  the  just-mentioned  spheres. 

Passing  to  the  oesophageal  commissures  and  their  ganglia,  the 
author  points  out  that  the  former  are  made  up  of  fibres,  which  arise 
from  the  dotted  substance  of  the  anterior  and  posterior  swellings  of 
the  cerebrum.  After  giving  a  careful  description  of  the  ganglion 
and  of  the  nerves  which  are  given  ofi"  from  it,  he  passes  to  a  considera- 
tion of  the  difierent  parts  of  the  ventral  chain  ;  he  here  enters  into 
great  detail,  which  it  would  be  impossible  to  make  clear  without  a 
rcj)roduction  of  the  figures  by  which  they  are  illustrated. 

Influence  of  Acids  and  Alkalies  on  Crayfishes.*  —  M.  Eichet 
commences  by  pointing  out  the  impossibility  of  subjecting  air-breathing 
animals  to  the  influence  of  acids  or  alkalies.     On  the  other  hand,  the 

*  '  ComptcH  lleuduci,'  xc.  (18S0)  p.  1166. 


INVERTEBKATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  629 

crayfish  affortls  an  extremely  easy  subject,  and  the  author  has  been 
enabled  by  its  aid  to  convince  himself  that  acids  or  alkalies  are  not 
poisonous  because  of  their  acidity  or  alkalinity.  This  is  shown  by 
the  following  facts :  A  crayfish  can  live  for  two  or  three  hours  in 
water  containing  25  grammes  per  litre  of  acetic  acid ;  if  there  are 
only  20  grammes  per  litre  it  can  live  for  half  a  day.  The  mineral 
acids  are  the  most  fatal ;  in  5  grammes  (per  litre  of  water)  of  sul- 
phuric acid,  a  crayfish  dies  in  less  than  an  hour ;  if  the  water  only 
contains  1  gramme  per  litre  it  may  live  for  ten  to  twelve  hours. 
Nitric  acid  has  still  more  marked  effects  ;  half  a  gramme  in  a  litre  of 
water  will  kill  a  crayfish  in  two  or  three  hours,  and  if  the  quantity  of 
acid  be  doubled,  the  creature  will  die  in  half  an  hour  at  the  outside. 
The  first  tissue  to  be  aff'ectcd  appears  to  be  the  muscular,  and  it  is  a 
long  time  before  the  effects  are  lost  after  the  animal  is  removed  from 
the  acidulated  water. 

Alkaline  solutions  appear  to  have  a  more  marked  eflfect ;  the  least 
hurtful  is  baryta,  of  which  3  grammes  may  be  put  into  a  litre  of  water 
for  the  crayfish  to  remain  alive  for  two  or  three  hours.  The  most  fatal 
alkali  is  ammonia ;  half  a  gramme  in  a  litre  of  water  has  an  almost 
instantaneous  effect,  and  even  with  one-tenth  of  a  gramme  the  crayfish 
dies  in  two  or  three  hours.  It  is,  in  fine,  even  more  fatal  than 
strychnine. 

The  difierences  in  efiect  would  appear  to  be  due  to  the  difierent 
degree  in  which  the  drugs  are  absorbed  by  the  respiratory  organs. 

Head  of  the  Lobster.* — Professor  Young  shows  some  important 
relations  in  the  grooves  on  the  carapace.  The  so-called  "  cephalic 
groove  "  is  really  double :  its  anterior  lateral  branch  starts  from  the 
antennary  sternum,  and  marks  off  a  prestomial  segment.  This  dis- 
tinction of  a  prestomial  region  is  paralleled  in  the  Annelids,  where 
also  it  is  supplied  from  the  supra-cesophageal  ganglion.  In  the  Stoma- 
poda  and  in  the  Poutellida^  the  antennary  segment  is  free.  The  posterior 
lateral  branch  begins  rather  posteriorly — behind  the  maxillipedes — 
and  passes  forward  to  join  the  former  opposite  the  articulation  of  the 
mandible.  Fi-om  the  posterior  position  of  this  latter  groove,  which 
marks  tbe  hinder  limits  of  the  strictly  oral  segments,  it  is  seen  that  no 
place  is  left  for  the  sterna  of  the  maxillipedes'  segments,  and  their  terga 
are  but  small. 

Claus's  statement  that  the  mandibles  do  not  originate  from  the 
third  pair  of  Nauplius  limbs,  but  from  the  body-surface  behind  them,  is 
borne  out  by  the  observation  of  such  a  development  of  it  from  the 
lateral  oral  margin  behind  and  on  the  inner  side  of  the  third  pair  of 
appendages  in  some  Macrurous  larvfx^ ;  it  is  thus  similar  in  origin  to 
the  labrum  ;  probably  the  third  larval  pair  of  limbs  fuses  with  it,  con- 
stituting the  mandibular  palp,  which  is  supplied  from  the  sujira- 
CESophagcal  ganglion,  which  also  supplies  all  the  prestomial  region. 

This  prestomial  region  includes  the  eyes,  antenna;,  antcnnulcs, 
with  the  sense-sacs  at  thcii'  base  ;  it  is  a  primitive  division  of  the 
body,  and  its  relation  to  the  nervous  centres  supports  the  view  that 

*  '  Joum.  Anat.  et  Pliysiol.'  (Humphry),  xiv.  (ISSO)  p.  348. 


630  RECOBD   OF    CURRENT   RESEARCHES   RELATING   TO 

the  supra-oesoiihageal  gauglion  is  one  of  a  tergal  series  of  ganglia  cor- 
respontling  to  the  more  fully  developed  sternal  set,  and  so  the  I'egion 
itself  may  consist  simply  of  terga  whose  development  has  been  affected 
by  the  disproi^ortionate  growth  of  the  terga  posterior  to  them,  which 
constitute  the  carapace. 

Shortened  Development  in  Palaemon  potiuna.* — To  the  list  of  land 
and  fresh-water  animals  which  dispense  with  the  development  through 
which  their  marine  allies  pass,  Dr.  Fritz  Miiller  adds  the  Brazilian 
Trichodactylns  and  ^glea  Odebrechtii  from  the  Decapod  Crustacea.  The 
fresh-water  shrimps  of  the  mouth  of  the  Itajahy,  however — a  Leander, 
a  Pcdcemon,  and  a  species  of  the  Atijince — leave  the  egg  in  the  zooea 
stage.  On  the  other  hand,  the  female  of  Palcemon  potiuna,  instead  of 
laying  the  large  number  of  eggs  usual  with  kindred  species  under  the 
same  conditions,  produces  from  six  to  twenty  large  ova,  2  mm.  in 
length,  from  which  issue  young  of  5  mm.  length,  having  all  the  deport- 
ment of  adults,  whose  form  they  assume  fully  at  the  fourth  change  of 
skin.  The  condition  in  which  the  young  leave  the  egg  is  that  of  the 
larva  of  Hipiiolyte  polaris,  except  that  the  gills  arc  well  developed 
while  the  mouth-parts  are  mere  rudiments. 

The  changes  through  which  the  different  organs  pass  with  the  four 
changes  of  skin  are  as  follows  : — 

Frontal  process  of  the  carapace,  from  a  short  tooth-  and  hairless 
process  to  one  with  generally  six  to  seven  teeth,  with  corresponding 
tufts  of  hair  in  front  of  them  on  the  upper  edge  and  one  or  two  on  the 
lower  edge,  which  bears  a  double  row  of  hairs. 

Front  edge  of  carapace  at  first  bears  a  single  inferior  bristle,  and 
finally  an  antennal  and  hepatic  bristle,  a  branchiostegal  having 
appeared  in  the  fourth  stage,  and  having  apj)arently  fused  with  the 
hej)atic  in  the  last  stage. 

Front  antenna  at  first  zooeiform  ;  protopodite  unsegmentcd,  a 
bristle  on  the  inner  branch,  two  such  on  the  outer  one ;  finally,  each 
of  the  last  segments  (generally  ten  in  the  male)  of  the  inner  division 
of  the  outer  branch  bears  two  transverse  series  of  two  or  three  olfac- 
tory filaments  each. 

Hind  antenna,  from  having  only  the  outer  branch  segmented,  has 
both  segmented,  and  provided,  the  one  with  bristles,  the  other  with 
numerous  bristles  and  a  spine  ;  this  condition  is  reached  at  the  second 
stage. 

Mandible  becomes  two-branched,  toothed,  with  a  palp,  instead  of 
consisting  of  a  single  simple  cylinder. 

Maxillce  do  not  alter,  nor  do  the  anterior  maxillipedes,  materially. 

Middle  and  posterior  maxillipedes :  the  inner  branches  from  the 
beginning  are  long,  strong,  and  devoid  of  swimming  hairs,  but  carry 
terminal  claws,  serving  as  legs ;  the  only  change  is  that  they  become 
comparatively  weaker. 

Chelate  feet,  from  a  segmented  but  rounded,  hairless,  immobile 
form  to  chelate  appendages  with  comb-like  ornatory  spines  (the  pos- 
terior pair  becomes  longer  than  the  body  in  very  old  males). 

*  '  Zool.  Anzeig.,'  iii.  (1880)  p.  152. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  631 

Ambulatory  abdominal  legs,  from  being  hairless  and  immobile, 
become  fully  developed  at  the  first  change  of  skin. 

Gills  fully  developed  from  the  first, 

Post-ahdominal  legs  begin  by  having  all  their  ultimate  structures, 
except  the  hairs  and  grasping  hooks,  of  which  the  here  specially 
long  appendage  of  the  endopodite  of  the  second  pair  is  the  last  to  bo 
added. 

Tail  has  a  distinct  end-piece,  with  thirty-two  to  thirty-four  bristles, 
mostly  plumose  on  both  sides  :  the  lateral  tail-pieces  arc  visible  in  tho 
interior.  At  the  third  stage  the  feet  and  outer  and  inner  lateral 
laminae  appear ;  at  the  fourth  the  inner  laminfe  are  longer  and  broader, 
and  set  round  with  plumose  bristles  ;  at  the  fifth  and  last  the  median 
piece  becomes  pointed,  and  carries  two  i^airsof  strong  spines  laterally. 
The  number  of  its  plumose  hairs  diminishes  to  eight  or  nine  (subse- 
quently raised  to  twenty  and  upwards). 

The  reason  of  the  almost  entire  absence  of  the  zooea-structures  in 
tho  newly-hatched  young  appears  to  be  due  to  the,  at  times,  turbu- 
lent streams  inhabited  by  the  species,  which  are  liable  to  be  flushed 
by  torrents ;  hence  tho  zooea  and  all  larval  stages,  in  which  a 
swimming  mode  of  progression  exposes  them  to  injury  from  this 
cause,  are  passed  through  in  three  or  four  days,  at  the  end  of  which 
time  the  ambulatory  legs  with  their  sharp  and  strong  claws  are  well 
developed. 

It  is  strange  that  the  very  closely  allied  Hippohjte  polaris  also  has 
a  shortened  development,  while  a  Brazilian  Hippolyfe  is  known  to 
emerge  from  the  egg  as  a  zooea. 

Toilet-appendages  of  the  Crustacea.* — In  tho  genus  Pahvmon, 
Dr.  Fritz  Miiller  states,  tho  first  pair  of  feet  is  used  for  the  cleansing 
of  tho  body  and  the  respiratory  chambers.  Its  structure  adapts  it 
admirably  for  this  purpose  :  it  is  slender,  often  exceeding  the  body  in 
length,  and  its  pincers  are  small,  but  the  grasping  limb  is  articu- 
lated so  as  to  bo  movable  in  almost  any  direction ;  at  tho  proximal 
end  of  tho  chela3  arc  ranged  several  groups  of  short  bent  bristles  with 
comb-liko  teeth  on  their  inner  aspects.  The  outside  of  each  limb  of 
the  pincers  carries  several  bundles  of  straight,  stiff,  roughened  bristles, 
so  that  it  resembles  a  brush  ;  their  inner  side  also  carries  a  similar 
series  of  smaller  bundles,  pointing  towards  the  apex,  and  so  arranged 
as  to  interlock  when  the  "  fingers  "  are  brought  together. 

In  the  working  of  these  parts  in  life  this  pair  of  limbs  is  applied 
to  all  parts  of  tho  body,  and  especially  to  tho  respiratory  chamber, 
and  is  there  moved  about  so  as  to  remove  foreign  particles.  They 
are  also  used  to  convey  to  the  mouth  small  pieces  of  carrion  whicli 
they  have  torn  oft';  the  animal  also,  according  to  Hcnscn's  observations, 
uses  them  to  place  grains  of  sand  in  tho  auditory  cavity  after  each 
change  of  skin,  as  the  mass  of  sandy  otoliths  is  cast  oft'  with  tho 
skin. 

In  other  Shrimps,  as  Alphais  and  Palcemon,  it  is  probably  tho 
second  pair  of  feet  which  fulfils  the  cleansing  function  ;  they  are  very 

•  'Ko8ino.s,'  iv.  (ISSO)  p.  lis. 


632  RKCORD   OF    CURRENT    RESEARCHES    RELATING    TO 

slender,  carry  small  diclfe,  and  arc  rendered  more  mobile  by  the  fact 
that  the  fore-arm  is  broken  up  into  a  number  of  small  joints :  the 
first  pair  of  legs  is  strong,  with  powerful  cheloB.  In  the  hermit-crabs, 
the  porccllanoiis  crabs,  and  the  Galatheidso,  on  the  other  hand,  it  is 
the  fifth  jiair  which  is  thus  used ;  they  are  thin,  with  very  mobile 
joints,  have  small  pincers  well  supplied  with  brushes,  combs,  &c. ; 
they  chiefly  act  on  the  gill-pouch.  A  commensal  Porcellana  living 
with  an  especially  mucous  worm,  was  observed  to  keep  these  limbs  in 
constant  motion  over  all  parts  of  the  body.  In  the  crayfish,  lobster, 
and  prawn  none  of  the  pairs  of  feet  appear  adapted  for  this  purpose. 

In  the  Crabs,  each  of  the  six  maxillipedes  bears  a  long  process, 
pointing  backwards,  the  edges  thickly  set  with  long  hairs ;  the 
whole  has  the  outline  of  a  sabre,  and  acts  like  a  dusting-brush.  The 
one  belonging  to  the  first  pair  lies  outside  the  branchial  cavity,  the 
other  within  it,  where  they  constantly  play  backwards  and  forwards 
between  the  branchiae  and  the  carapace.  The  hairs  which  clothe  them 
show  an  immense  variety  in  the  form  and  arrangement  of  their  teeth, 
of  which  Trichodactylus,  Gelasimus,  Hepatas,  and  Lupea  afford  in- 
teresting examples.  In  Trichodactylus  the  inner  wall  of  the  chamber, 
too,  bears  a  number  of  small  protuberances,  each  terminated  by  a 
spine  ;  the  function  of  the  spines  is  to  cleanse  the  hairs  of  the  brushes 
above  mentioned,  as  they  pass  to  and  fro.  Trichodactylus  is  also 
remarkable,  though  not  entirely  peculiar,  for  leaving  the  egg  as  a 
fully  developed  crab. 

Anal  Respiration  of  the  Copepoda.* — Mr.  M.  M.  Hartog,  in  a  note 
on  Cyclops  read  at  the  British  Association,t  pointed  out  that  its  respi- 
ration was  exclusively  anal.  He  has  now  made  out  the  same  in 
Canthocamptus  (fam.  Harpacticidas),  and  Diaptomus  (fam.  Calanidje). 
In  all  three  the  mechanism  is  the  same ;  at  regular  intervals,  after 
the  backward  sway  of  the  intestine,  the  anal  valves  open  for  an 
instant  and  then  close,  giving  just  time  for  a  slight  indraught  of 
water  after  the  opening,  a  slight  expulsion  at  the  close.  The  necessary 
pressure  to  confine  the  animal  seems  to  interfere  somewhat  with  these 
movements,  sometimes  stopping  them,  if  excessive  ;  hence  he  "  refrains 
from  noting  with  illusory  exactness  the  intervals  between  each 
respiratory  movement." 

It  is  to  be  noticed  that  the  rectum  contains  as  a  rule  liquid  only, 
the  bolus  of  faeces  remaining  in  it  but  a  short  time.  By  endosmose 
the  liquid  in  the  rectum  will  tend  to  be  at  the  same  condition  of 
gaseous  saturation  as  the  body-fluid  around  it,  kept  constantly  agitated 
by  the  backwards  and  forwards  sway  of  the  stomach.  During  the 
short  interval  that  the  anus  is  open  an  approach  to  gaseous  equilibrium 
with  the  external  water  takes  place,  even  despite  the  very  slight  move- 
ment of  the  water  (shown  by  the  little  change  of  place  undergone  by 
suspended  indigo  or  carmine  particles).  In  the  absence  of  any  other 
suitable  respiratory  apparatus,  no  one  can  hesitate  as  to  the  function  of 
the  action  described. 

In  the  Nauplius  larvae  of  Cyclops  and  Diaptomus  the  working  is 

*  '  Quart.  Jonin.  TMicr.  Sci.,'  xx.  (1880)  p.  244.  t  ^ntc,  p.  254. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  633 

slightly  different.  The  rectum  is  a  subspherical  muscular  sac,  which 
at  regular  intervals  contracts  so  as  to  leave  a  linear  cavity  (along  the 
long  axis  of  the  animal),  and  immediately  dilates,  sucking  up  the 
water  from  without.  An  anal  respiration,  such  as  that  of  Cyclops,  is 
found  widely  among  Crustacea — even  those  which  have  well-developed 
gills  like  Asfacus,  which  is  one  of  the  highest  forms.  It  has  been 
demonstrated  in  Phyllopoda  and  Cladocera,  and  is  probably  the  exclu- 
sive mode  in  Leptodora,  as  shown  by  Weismann.  That  it  is  therefore 
primitive,  and  should  be  expected  to  occur  in  the  primitive,  or  at  least 
very  generalized  group  of  the  Copepoda,  is  an  obvious  deduction. 
Hence  the  author  anticipates  that  the  homoiomorphic  zooea  larvaD  of 
the  Decapoda  will  prove  to  have  this  same  mode  of  respiration. 

If  there  bo  any  connection  between  Rotifers  and  NauijUus,  it  is 
easy  to  make  out  the  origin  of  the  arrangement  in  the  latter.  The 
ciliated  funnels  and  lateral  canals  of  the  former  can  only  be  of  service 
when  there  is  a  thin  unchitinized  anterior  surface  through  which 
water  can  transude  into  the  ccelom  ;  by  the  extension  of  chitinization 
over  the  whole  surface,  these  organs  lose  their  function  and  abort, 
while  the  cloacal  "  contractile  vesicle "  takes  on  an  inspiratory  as 
well  as  an  expiratory  function,  and  becomes  more  or  less  confounded 
with  the  rectum,  from  which  probably,  even  in  Eotifers,  it  takes  origin. 

Here  must  be  noticed  the  wide  diffusion  of  anal  respiration  in 
aquatic  insect  larvfe  (alternate  inspiration  and  expiration  by  the 
pumping  movements  of  the  rectum).  This  would  point  to  a  common 
origin  with  Crustacea. 

A  list  of  the  groups  in  which  anal  respiration  is  made  out  may  bo 
added  : — 

Vebmes  : 

Eotifera. 

Gephijrca. 

Oliijochwto-Limicola. 

ECHINODEEMATA  : 

Ilolothiiroidea. 
Arturopoda  : 

Crustacea  (f^cncral). 

Insccta  (most  aquatic  larvas). 
MOLLUSCA  : 

Dentalium, 

Parasitic  Corycseidse.* — Dr.  Delia  Vallo  makes  some  contributions 
to  our  knowledge  of  the  anatomy  of  the  genus  LirliomoJgus,  somo 
species  of  which  are  parasitic  on  Actinia.',  while  others  are  found  on 
Mollusca,  Worms,  or  Tunicates.  He  describes  as  new  L.  ndin'uv, 
li.  ftcroulis  (on  Pleroklcs  fipinulnsus),  and  L.  chromodo^'idis,  of  which 
the  female  is  alone  known.  IIo  forms  a  now  genus,  Anthcssus,  for 
some  forms  allied  to  Lichomohjus,  the  sjiecies  of  which,  A.  Solvcurli, 
and  A.  plcurohranrhitc  arc  distinguished  by  the  characters  of  their 
mouth-organs. 

Parasite  of  the  American  Blue  Pike.t — Professor  D.  S.  Kellicott 
describes  a  new  species  of  Anjidm  found  on  tlie  blue  pike  {Stizostelhiiim 

*  '  Jlitth.  Zool.  Stat.  Neapfl,'  ii.  (ISSO)  p.  S'X 

t  'Am.  Jouni.  Micr.,'  v.  (1.MS0)  p.  ^[i.     Kio  '  Naturo,*  xxii.  (ISSO)  p.  111. 


634  KECORD    OF    QUERENT    RESE.\.RCIIES    RELATING    TO 

salmonewn  Jord.).  Tlic  fishermen  of  the  Niagara  river  at  Buftalo 
say  that  when  the  water  becomes  warm  the  fish  gets  too  lazy  to  take 
food,  that  it  then  loses  flesh,  and  through  its  inertness  becomes 
infested  with  these  lice.  Having  given  this  subject  especial  attention, 
Professor  Kellicott  is  inclined  to  think  the  account  of  the  fishermen 
is  correct.  The  parasite  occurs  usually  on  the  top  of  the  head  of  the 
fish.  When  there  are  several  they  arc,  as  a  rule,  huddled  together, 
often  in  heaps,  so  that  the  knife  may  remove  a  number  at  once ;  it 
occurs  also  on  the  fins.  None  were  found  in  the  mouth-cavity.  As 
many  as  twenty  were  taken  from  one  lean  fish. 

When  living  specimens  of  the  Argulus  were  placed  in  a  tank  with 
a  small  specimen  of  Lejpidosteus  osseus  and  some  minnows,  tliey  shortly 
fixed  on  them,  and  the  minnows  soon  died,  apparently  killed  by  the 
parasites.  When  first  put  in,  the  fish  would  pursue  and  catch  them, 
but  would  eject  them  with  a  suddenness  and  a  queer  expression  that 
was  most  amusing.  In  a  few  moments  they  were  left  unnoticed  by 
the  minnows.  The  gar  recoiled  in  evident  fear  when  one  would  be  seen 
approaching.  A  large  female  once  fastened  on  to  the  long  nose  of  the 
gar,  where  it  clung  for  several  days,  despite  the  vigorous  efforts  of 
the  fish  to  dislodge  it.  Cold  weather  seemed  to  destroy  them  ;  the 
fishermen  assert  that  after  frosts  the  blue  pike  become  fat,  and  then 
no  lice  are  found  on  them. 

The  species  is  called  A.  stizostethii.  The  author  believes — against 
the  assertion  of  Leydig — that  the  abdominal  lobes  have  a  function  of 
resjiiration  above  all  other  parts  of  the  body,  and  he  describes  with  a 
good  deal  of  detail  the  appendages  to  the  several  legs. 

New  Crustacea. — Mr.  G.  M.  Thomas  describes  *  some  Crustacea 
from  Dunedin  Harbour,  New  Zealand,  the  maximmn  depth  of  which 
is  about  6  fathoms.  They  include  one  new  genus  and  six  new 
species : — Mysis  denticulata,  Parafanais  tenuis,  Panoplcea  (n.  gen.) 
spinosa,  P.  dehilis,  AnijMlochus  squamosus,  and  Megamoera  fasciculata. 
The  last  five  are  figured. 

Mr.  T.  W.  Kirk  describes  |  Paliniirus  himidus,  the  common  craw- 
fish of  the  Sydney  market,  the  total  length  of  which,  from  tip  of  beak 
to  end  of  telson,  is  24  inches,  with  a  much  swollen  carapace 
21^  inches  in  circumference.  Though  so  large  and  common,  it  does 
not  appear  to  have  been  hitherto  described.  It  is  very  near 
P.  Hugelii,  from  the  Indian  Ocean,  but  distinguished  by  its  miich 
larger  size,  by  the  beak,  supra-orbital  and  antennal  spines  being 
turned  upwards,  and  by  the  telson  being  less  triangular  and  rounded 
instead  of  scarped. 

H.  Eehberg  has  investigated  |  a  spring  in  the  island  of  Heligoland. 
He  found  Gammanis  puteanus,  a  Cyclops  which  has  been  assigned  by 
Fric  to  C.  indcTiellus  Koch,  but  which  is  a  new  species,  a  new  Acarid, 
and  a  new  Pleuroxus,  P.  puteanus,  n.  sp.  The  latter  is  distinguished 
by  having  the  body  contracted  behind,  and  the  cephalic  rostrum  of 
about  the  same  length  as  the  labial  appendage,  and  the  eye  four  times 

*  '  Ann.  and  Mag.  Nat.  Hist.,'  vi.  (1880)  p.  1.  t  Ibi<l.,  p.  14. 

X  '  Zool.  Anzeig.,'  iii.  (1880)  p.  301. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  635 

the  size  of  tlie  accessory  eye.  Labial  appendage  comparatively  large, 
distinctly  notched  so  as  to  appear  as  if  composed  of  two  blunt  lobes  ; 
hind  edge  of  shell  straight,  lower  edge  clad  thickly  with  fine  bristles, 
and  having  a  spine  behind.  Surface  of  shell  smooth.  Postabdomen 
broad,  contracted  at  posterior  third,  beneath  which  occur  eight  double 
teeth.  A  short  and  a  long  spine  at  the  base  of  the  caudal  hooks. 
Length,  "33  mm.;  height,  -25  mm.  Its  nearest  ally  is  Pleuroxus 
trigonellus  O.  F.  Miiller. 

The  Cyclops,  G.  helgolandicus  n.  sp.,  has  the  front  antennre  of 
fourteen  segments,  and  reaching  to  the  end  of  the  first  body  segment 
when  laid  back  ;  the  first  and  eighth  segments  agree  in  length,  and  the 
fourth  and  seventh,  which  also  agree,  are  together  equivalent  to  one 
of  these.  Second  pair  of  antenna?  of  four  segments,  the  first  being  the 
longest.  Eye  with  four  edges,  red  or  red-brown.  Last  segment  of 
outer  branch  of  fourth  pair  of  feet  has  two  spines  externally,  a  sj^ine 
and  bristles  above,  and  three  long  bristles  internally.  Rudimentary 
foot  consists  of  a  broad  basal  joint  with  an  external  bristle,  and  a 
narrow  terminal  joint  with  a  spine  and  a  long  bristle.  The  last 
abdominal  segment  is  the  shortest,  hinder  edge  fringed  with  fine  hairs  ; 
caudal  fnrca  four  times  as  long  as  this,  its  latter  bristle  at  the  third 
fifth.  The  ovisacs  contain  twelve  to  twenty  eggs,  round,  projecting 
from  the  body.     Total  length,  1-GG  mm. ;  without  furca,  1'36  mm. 

It  appears  to  be  derived  from  C.  pulchellus  Koch,  difiering  from 
it  mainly  in  having  three  fewer  antennal  joints,  in  being  smaller,  in 
the  shortening  of  the  basal  joint  of  the  first  segment  of  the  rudi- 
mentary feet,  and  of  the  second  outer  bristle  of  the  caudal  furca  ;  but 
the  species  are  alike  distinguished  from  all  others  by  a  fringe  of  fine 
hairs  on  the  first  quarter  of  the  furca,  and  by  the  position  of  the 
lateral  bristle  of  the  same  at  the  third  fifth  of  its  length,  and  some 
other  points. 

The  well  was  closed  in  1809,  so  that  the  species  appear  to  have 
become  thus  modified  in  the  intervening  period  of  seventy-one  years. 

Vermes. 

Genital  Glands  and  Segmfintal  Organs  of  the  Polychaeta.* —  After 
a  short  review  of  the  history  of  our  knowledge  of  this  subject, 
M.  Cosmovici  commences  an  account  of  his  own  investigations  by  a 
detailed  descrii)tion  of  the  anatomy  of  Arcnicola  piscnlorum.  In  dealing 
with  the  circulatory  system,  he  points  out  (1)  that  the  branches  of 
the  ventral  vessel  go  to  a  gill ;  (2)  that  they  meet  with  a  segmental 
organ,  or  (3 )  that  they  meet  with  both  gill  and  scgruental  organ. 

In  describing  the  segmental  organs,  ho  commences  by  directing 
attention,  in  the  first  place,  to  the  structui'o  which  he  calls  the  organ 
of  Bojanus.  Of  these  there  -are,  in  Arcnicola,  six  pairs,  which  arc 
placed  on  either  side  of  the  ganglionic  chain,  ami  in  the  cephalo- 
tlioracic  portion  of  the  lateral  chamlxjrs  of  the  body.  They  arc  not 
fi)und  anteriorly  to  the  third  or  posteriorly  to  the  eighth  segment  of 
ihe  body.    Though  very  variable  inform,  it  is  iiossiblc  to  make  out  in 

»  ' Arcli.  Z.>ol.  txp.  ct  gen.,'  viii.  (1880)  p.  2:53. 


G3G      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

them  an  external  border,  wliicla  is  concave,  and  by  wliich  tliey  arc 
attached  to  the  wall  of  the  body,  and  a  convex  border  which  is  free 
and  directed  towards  the  ganglionic  cord.  The  anterior  extremity  is 
convex,  and  is  always  closed ;  though  the  posterior  extremity  appears 
to  be  glandular  in  character,  it  is  not  really  so  ;  the  appearance  is 
due  merely  to  its  great  contractility,  and  it  is  at  this  end  that  the 
gland  communicates  with  the  exterior.  This  communication  is 
eficcted  by  a  circular  pore,  of  some  size,  which  is  only  difficult  to  see 
on  account  of  the  rich  supply  of  muscles  with  which  it  is  provided. 
In  addition  to  this  communication  with  the  interior,  the  pouches  also 
communicate  with  the  "visceral  chamber"  by  an  orifice  placed  near 
their  anterior  extremity ;  the  whole  of  the  interior  is  provided  with 
very  long  cilia,  which  work  towards  the  exterior  orifice.  In  structure, 
these  organs  may  be  regarded  as  being  composed  of  a  wall,  and  of  an 
epithelium.  The  wall  is  formed  of  muscular  fibres,  and  of  connec- 
tive tissue ;  the  former  are  most  abundant  in  the  region  of  the 
posterior  orifice.  The  epithelial  layer  is  composed  of  spherical  cells, 
filled  with  yellow  granules  ;  the  most  superficial  are  ciliated  and 
deej^ly  pigmented.  The  walls  are  highly  vascular,  but  there  is  no 
indication  whatever  of  any  glandular  structure.  The  author  is  of 
opinion  that  not  only  in  structure,  but  also  in  function,  these  bodies 
are  to  be  compared  with  the  molluscan  organ  of  Bojanus. 

Turning  next  to  the  segmental  organs,  we  find  that  we  have  an 
organ,  the  tissue  of  which  is  completely  transparent,  and  which 
is  largely  supplied  with  blood-vessels ;  these  bodies  are  connected 
with  the  organ  of  Bojanus,  and  open  by  a  wide  orifice  into  the  body- 
cavity.  By  means  of  this  orifice,  the  tubes  are  easily  enabled  to 
act  as  the  efferent  ducts  for  the  generative  products.  Connected 
with  the  segmental  organs,  and  like  them  arranged  in  six  pairs,  we 
find  the  ovaries  or  testes:  these  are  racemose  in  form,  and  their 
products,  which  escape  young,  fall  first  of  all  into  the  body-cavity. 
The  student  of  this  subject  will  see  that  the  results  here  given  are 
very  far  from  being  in  accordance  with  the  views  of  Williams  ;  the 
comparison  which  the  author  institutes  between  them  can  only  be 
referred  to,  as  it  is  impossible  to  give  any  abstract  of  his  review. 

Development  of  the  Spermatozoa  of  the  Earthworm.* — Mr. 
Blomfield  commences  with  a  careful  account  of  the  position  and 
appearance  of  the  testes  of  the  earthworm,  which  is  of  value,  as  the 
much  more  prominent  seminal  vesicles  are  often  mistaken  for  them. 
He  describes  them  as  pure  white,  translucent  bodies,  irregularly 
quadrangular  in  form,  and  rarely  more  than  -^^  inch  in  diameter.  By 
the  assistance  of  Mr.  Bourne,  the  author  is  enabled  to  explain  how  it  is 
that  the  seminal  vesicles  are  ordinarily  taken  for  testes.  In  order  to 
demonstrate  the  truth  of  Hering's  account  of  the  arrangement  of  these 
parts,  Mr.  Bourne  examined  a  scries  of  earthworms,  and  was  able  to 
demonstrate  that  in  full-grown  forms,  such  as  are  ordinarily  chosen 
for  dissection,  the  vesicles  are  so  fully  developed  that  the  true  testes 
arc  completely  hidden  from  view.      In  immature  specimens,  these 

*  'Quart.  Journ.  Micr.  Sci.,'  xx.  (1880)  p.  70. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  637 

vesicles  form  six  small  outgrowths  on  the  septa  of  the  ninth- 
tenth,  tenth-eleventh,  and  eleventh-twelfth  segments,  respectively ; 
the  anterior  pair  grow  forward  so  as  to  project  into  the  ninth  ring, 
tlie  second  grow  backward  into  the  eleventh,  and  the  third  into  the 
twelfth  ring ;  "  the  ciliated  rosettes  "  of  the  seminal  ducts  are  found 
in  the  tenth  and  eleventh  rings,  and  by  these  the  developing  sperm- 
cells  of  the  testes  pass  into  the  seminal  reservoirs  or  vesicles,  which 
become  gradually  larger  as  sexual  maturity  apjiroaches. 

After  an  account  of  the  minute  structure  of  the  seminal  vesicles, 
the  author  passes  to  his  more  immediate  subject. 

Development  of  the  Spermatozoa. — "  If  a  portion  of  the  contents  of 
a  seminal  reservoir  are  examined  in  salt  solution,  a  great  many  of  the 
stages  of  the  developing  spermatozoon  are  exhibited  in  one  field." 
In  his  account  of  this  subject,  the  author  makes  use  of  some  terms 
suggested  to  him  by  Professor  Lankester  ;  the  spcrmatospore  is  a  term 
applied  to  the  "  constituent  cells  of  a  testicle,  derived  from  tho 
primitive  germ-epithelium  " ;  these  cells,  by  the  division  of  their 
nuclei,  give  rise  to  "  spermatospheres"  or  "  sperm-polyplasts."  "  Each 
constituent  of  a  sperm-j^olyj^last  is  a  spermatoblast,  and  when  the 
process  of  division  is  over  each  spermatoblast  becomes  a  sperma- 
tozoon. It  does  not,  however,  hai:)pen  that  the  whole  spermatosjihere 
is  converted  into  spermatoblasts ;  there  remains  a  passive  portion, 
which  in  the  earthworm  occupies  a  central  position ;  this  is  tho 
"  sperm-blastophore,"  or  "  blastophoral  cell." 

The  author  then  enters  into  a  careful  account  of  the  development 
of  the  bodies  thus  defined,  which  is  illustrated  by  his  own  drawings, 
and  comes  to  conclusions  which  are  best  stated  in  his  own  succinct 
resume :  The  nucleus  of  the  spermatospore  in  the  young  testis  is  of 
unusually  large  relative  size  ;  the  second  nuclei  to  which  it  gives  rise 
stand  out  around  tho  central  mass  (blastojihore)  of  tho  generating 
spheroid  with  very  little  protoplasm  clothing  them.  The  nucleus 
undouhtedhj  becomes  the  rod-like  head  of  the  earthivorm's  sperma- 
tozoon, and  tho  filament  is  as  undeniably  formed  from  non-nuclear 
protoplasm. 

The  sperm-blastoplioro  of  tho  earthworm  is,  however,  non- 
nucleated,  while  in  the  frog  and  salamander  the  corresponding  boily 
is  nucleated.  This  diflfercnce  is,  it  is  suggested,  duo  to  the  fact  that  in 
the  earthworm  the  spermatoblasts  are  further  developed,  not  in  testes, 
but  in  the  seminal  reservoirs,  while  in  tho  vertebrates  just  mentioned 
a  portion  of  the  blastophoro  alone  passes  oil',  while  the  rest  remains 
ready  to  resume  its  activity.  In  fact,  what  hai)pcns  in  the  eartli- 
worm  is  the  remarkable  i)henomcnon  of  tho  primitive  testis-cells 
passing  into  another  organ  in  order  to  xmdorgo  their  development. 

Embryology  of  Ligula.* — M.  Moniez,  in  correcting  and  adding 
to  tlio  recent  accounts  of  this  phenomenon  given  by  MM.  Duchanip 
and  JJunnadieu,  points  out  that  before  develo])ment  conunenccs  tho 
egg  consists  of  a  single  egg-ccU  (which  has  been  taken  for  a  germinal 
vcsiclo) ;  this  lies  in  tho  midst  of  nutritive  globules  of  various  sizes, 

*  '  l?iill.  Sci.  IKp.  N.ird,'  iii.  (ISSQ)  p.  112. 


638  RECORD   OF   CURRENT    RESEARCHES    RELATING   TO 

which  generally  conceal  it.  Segmentation  takes  place  in  the  midst  of 
the  nutritive  yolk,  the  egg-cell  not  issuing  from  it  previously,  as  in 
Tcenia.  As  it  increases  in  size  it  drives  the  yolk-globules  to  the 
periphery,  where  they  often  present  the  appearance  of  polygonal  cells. 
After  segmentation  the  egg  consists  of  finely  granular  cells,  but 
slightly  connected  with  each  other  ;  it  undergoes  delamination  in  the 
same  way  as  in  TcBnia  ;  the  central  part  forms  alone  the  six-spined 
embryo,  the  external  part  becoming  clothed  with  cilia,  and  constituting 
the  "  embryophore,"  within  which  the  embryo  lives  free.  The  latter 
and  its  capsule  emerge  from  the  egg  on  the  disappearance  of  the  egg- 
operculum,  and  rapidly  (in  one  or  two  seconds)  become  far  greater  in 
size  than  the  egg  itself.  This  is  owing  to  the  absorption  by  the 
embryophore  of  a  large  quantity  of  liquid,  converting  it  into  a  finely 
granular  and  very  delicate  reticulum.  The  cilia  now  rotate  the 
whole  ;  they  are  short  and  uniformly  distributed ;  a  slight  pressure 
expels  the  embryo,  which  after  abandoning  the  embryoj)hore,  creeps 
about  by  amoeboid  movement,  showing  its  constituent  cells  plainly. 
It  is  therefore  the  embryophore — and  not  the  embryo,  as  stated  by 
M.  Donnadieu — which  moves  as  if  it  was  ciliated,  and  the  existence 
of  the  cilia  upon  it,  pointed  out  by  Leuckart  and  others,  is  beyond 
all  doubt. 

Nervous  System  of  the  Trematoda.* — Dr.  Lang's  second  com- 
munication on  this  subject  commences  with  an  account  of  the  nervous 
system  of  the  Tristomida.  After  reviewing  the  works  of  earlier  writers, 
among  whom  Blanchard,  Kolliker,  and  Taschenberg  (1879)  have  been 
the  most  conspicuous,  he  proceeds  to  give  an  account  of  his  own  inves- 
tigations on  Tristomum  molce.  The  best  subjects  for  investigation  are 
the  smaller  specimens,  on  account  of  their  greater  transparency ;  the 
principal  parts  of  the  nervous  system  can  be  made  out  in  the  living 
examples,  for  the  pale  nerve-cords  are  composed  of  coarse  fibres,  just 
as  in  Planocera  Graffii  among  the  Dendrocoelous  Turbellaria. 

The  flattened  body  of  these  creatures  has  its  periphery  almost  round ; 
at  the  anterior  end  of  the  ventral  surface  there  are  two  oral  suckers, 
and  in  their  neighbourhood  the  margin  of  the  body  is  so  indented  as  to 
give  the  appearance  of  a  quadrangular  median  lobe.  The  abdominal 
sucker  is  very  large  and  powerful,  and  is  connected  by  a  short  thin 
stalk  with  the  body.  On  either  side  of,  and  not  far  from  the  pharynx, 
there  are  two  vesicles  belonging  to  the  water- vascular  system.  The 
cerebrum  lies  anteriorly  and  superiorly  to  the  j^harynx  and  mouth ; 
in  form  it  is  a  short,  pretty  broad  transverse  band,  with  a  concave 
posterior  edge.  There  are  connected  with  it  four  small  pigment  spots. 
On  each  side  of  the  cerebral  mass  there  are  given  off  four  nerves, 
which  are  thus  distributed.  The  most  anterior  pass  to  the  region 
between  the  oral  suckers,  where  they  branch  and  anastomose.  The 
succeeding  nerves  supply  the  oral  stickers  themselves,  and  have  con- 
nected with  them  the  third  pair  of  nerves,  part  of  which  cross  over, 
however,  to  the  oj^posite  side  of  the  body.  Where  they  unite  in  the 
middle  line,  an  unpaired  nerve  passes  forwards  to  the  cephalic  lobe. 

*  •  Blittli.  Zool.  Stat.  Neapel,"  ii.  (1880)  p.  28. 


INVEKTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  639 

The  arrangement  tlius  brought  about  is  not  unlike  that  which  obtains 
in  P.  Grajfii,  where  all  the  nerves  given  off  from  the  brain  are  con- 
nected together  by  a  circular  commissure ;  but  in  Tristomum  there  is 
not  any  direct  continuation  between  the  commissures  in  the  posterior 
region.  The  foui'th  pair  of  nerves  passes  furthest  backwards ;  and 
these  may  be  seen  to  consist  essentially  of  a  feebly  developed  dorsal, 
and  of  two  well-developed  ventral  nerves  on  either  side.  Of  the  ventral 
trunks,  one  is  peripheral  and  external,  the  other  internal ;  these  again 
unite  in  the  region  of  the  great  ventral  sucker. 

After  describing  in  detail  the  distribution  of  these  nerves,  the 
author  passes  to  the  consideration  of  the  minute  structure  of  the  nervous 
system ;  the  examination  of  which  is  greatly  aided  by  the  large  size 
of  the  ganglion-cells  and  of  the  nerve-elements,  as  well  as  by  the  dis- 
tinctness of  the  nerve-tracts.  A  good  transverse  section  of  a  ventral 
longitudinal  nerve  exhibits  par  excellence  the  spongy  character  of 
these  fibres ;  of  these  there  is  a  network,  and  in  the  midst  of  them 
there  are  a  number  of  lumina  of  various  sizes  ;  these  all  contain  some 
coagulated  protoplasm,  and  in  the  larger  ones  nucleated  cells  are  also 
to  be  distinguished.  Careful  examination  of  a  number  of  sections 
reveals  the  existence  of  a  number  of  tubes  {neurilemma),  and  of  nerve- 
fibres  enclosed  in  these  tubes.  It  would  seem  that,  during  life,  the 
fibre  completely  fills  the  tube.  It  is  concluded  that,  histologically  at 
any  rate,  the  cerebrum  is  nothing  but  a  specially  and  highly  developed 
transverse  commissure,  which  indicates  its  relation  to  the  central 
nervous  system  by  being  composed  largely  of  ganglion-cells. 

The  eyes,  which  are  extremely  simple,  consist  of  (1)  an  aggrega- 
tion of  pigment  covering  in  (2)  a  spherical  or  oval  refracting  body, 
which  in  the  anterior  eyes  is  directed  backwards,  and  in  the  posterior 
forwards.  Connected  with  this  there  is  (3)  a  typical  ganglionic  cell 
which  forms  the  retina.  (4)  A  spherical  bundle  of  the  dorso-ventral 
muscles  appears  to  act  as  muscles  for  the  eye. 

Small  peripheral  nerve-centres  appear  to  be  represented  by  large 
cells  which,  scattered  through  the  body,  are  best  developed  in  the 
neighbourhood  of  those  regions  in  which  the  musculature  is  best 
developed. 

Pleurocotijle  scombri. — The  nervous  system  of  this  creature  is  the 
next  subject  of  Dr.  Lang's  investigations.  No  eyes  are  hero  develojied  ; 
the  cerebral  mass  is  delicate,  and  is  made  up  of  finer  fibres ;  the  most 
distinct  nerves  belong  to  four  series  : — 

(1)  A  pair  which  pass  forwards  to  the  suckers. 

(2)  A  i)air  which  i)ass  upwards — dorsal  nerves — but  which  could 
not  be  traced  for  any  great  distance. 

(3)  A  i)air,  which  pass  outwards  and  upwards,  and  are  soon  lost ; 
and  (4)  A  pair,  better  develoijed,  of  longitudinal  trunks,  which  take  a 
backward  course  along  the  ventral  siii-fuce. 

JJislomida. — The  examples  of  this  group  which  were  examined 
were  Uistoinum  nijrojlavum,  and  1).  hcjxilicum.  The  ceutiuil  nervous 
Bysteni  of  the  former  has  the  tyi'ieiil  position,  between  the  oral  sucker 
and  the  pharynx.  From  its  ujtptr  portion  tliero  is  given  oU'dorsally 
on  either  side  a  nerve  for  the  oral  sucker,  and  a  nerve  which  j>asecs 


GIO  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

backward ;  from  the  lower  surface  a  delicate  nerve  goes  to  tlie  ventral 
surface  of  the  oral  sucker,  while  there  are  also  two  ventral  longitudinal 
nerves  which,  soon  after  their  origin,  give  off  a  branch  which  takes 
a  dorsal  direction.  Very  similar  arrangements  are  to  be  found  in 
J),  hepaticum,  the  results  of  his  observations  on  which,  by  means  of 
sections,  the  author  carefully  describes. 

In  conclusion,  the  author  states  that,  with  regard  to  the  large  cells, 
principally  found  in  the  suckers  of  these  creatures,  he  is  not  able  to 
afiirm  that  they  have  any  connection  with  the  nerve-fibres  which  are 
distributed  to  the  same  parts.  But  he  is  of  opinion  that  they  are 
homologous  with  the  cells  of  similar  character  in  Tristomum,  and  he 
thinks  that  they  should  be  regarded  as  ganglionic  cells. 

New  Turbellarian.* — Dr.  Arnold  Lang  describes  a  new  parasitic 
Ehabdocoele  Turbellarian,  but  without  giving  it  any  name ;  it  seems, 
however,  to  be  closely  allied  to  Graffilla  muricicola ;  it  is  found  in 
numbers  on  the  foot  of  Tetliys,  but  hardly  appears  to  reside  there 
jiermancntly.  Spindle-shaped  when  extended,  and  whitish  in  colour, 
they  are  almost  completely  dense  ;  little  even  can  be  made  out  when 
they  are  compressed.  The  epithelium  of  the  integument  is  ciliated, 
and  the  cells  are  polygonal ;  no  sagittocysts  are  developed,  but  here 
and  there  there  are  pores  for  the  tegumentary  glands;  below  the 
integument  there  is  a  rudimentary  muscular  layer,  which  is  so  feebly 
developed  that  it  can  only  be  detected  in  very  thin  sections  ;  in  this 
region  there  are  a  large  number  of  unicellular  pyriform  glands,  which 
are  specially  developed  in  the  anterior  region  of  the  ventral  surface. 
The  pharynx,  and  its  musculature,  are  very  feebly  developed,  and  the 
former  appears  to  be  devoid  of  a  sheath.  The  intestine,  which  is 
aproctous,  forms  the  greater  part  of  the  animal ;  its  lumen  varies  in 
width  owing  to  the  development  of  inwardly  projecting  processes,  and 
its  walls  are  formed  by  very  long  tubular  cells,  distinctly  separated  from 
one  another,  and,  as  it  seems,  inserted  directly  into  the  integument. 
No  peripheral  nerves,  special  sensory  organs,  or  water-vessels  were 
detected.  The  female  organs  were  well  developed,  but  in  no  specimen 
was  the  author  able  to  find  the  male  glands  in  anything  but  a  rudi- 
mentary condition. 

New  Nemerteans.l — Dr.  Hubrecht,  in  a  first  appendix  to  a  paper 
already  noticed,  :j:  points  out  that  among  the  Palteonemertini  we- 
may  either  find  the  system  of  resj)iratory  furrows  represented  by  a 
number  of  small  grooves  (Polia),  or  there  may  be  only  a  simple  trans- 
verse furrow  {Ceplialotrix),  or  no  furrow  at  all.  He  then  describes  a 
new  species,  Carinella  inexpectata,  which  seems  to  be  intermediate 
between  the  two  forms  with  simple  or  compound  grooves ;  for  here  we 
have  to  do  with  a  transverse  groove,  provided  with  a  set  of  small 
secondary  grooves,  very  much  as  in  Polia ;  from  which,  however,  it 
differs,  and  agrees  with  the  simpler  forms  in  having  no  third  pair  of 
lobes  to  its  cephalic  ganglion.  The  other  new  species  described 
belongs  to  the  genus  Cerebratulus,  and  is  dedicated  to  Dr.  Eisig,  of 

*  'Mitth.  Zool.  Stat.  Ncapel,'  ii.  (1880)  p.  107. 

t  '  Notes  R.  Zool.  Mus.  Netherlands,'  ii.  (1880)  p.  93.  J  Ante,  p.  438. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  611 

Naples,  to  whom  tlie  author  owes  so  much.  Tho  spccimeu  on  which 
the  description  was  founded  was  sent  to  him  alive  from  Naples  ;  it  is 
distinguished  by  the  presence  of  longitudinal  stripes  on  its  proboscis, 
and  by  its  dark  olive-green  colour. 

Ech,inoderm.ata. 

New  Genus  of  Echinoidea.*— Under  the  name  of  Palceolampas, 
Professor  Jeffrey  I5ell  describes  an  irregular  Echinoid  allied  to 
Conoclypeus  and  Echinolampas,  but  distinguished  from  them  by  the 
possession  of  certain  more  archaic  characters  ;  tlie  pores  of  the  ambu- 
lacral  arese  are  arranged  in  pairs  as  far  as  the  ambitus  of  the  test, 
while  the  outer  row  of  each  pair  extends  regularly  to  the  actinostome. 
The  pores  of  each  pair  are  not  yet  connected  with  one  another  by 
grooves ;  those  of  the  inner  rows  are  still  fairly  circular,  but  many  of 
those  in  the  outer  rows  are  slit-like  or  comma-shaped,  and  indicate 
the  commencement  of  the  formation  of  the  groove  connecting  the  pairs 
of  pores.  Two  of  the  ocular  plates  are  interesting  on  account  of 
their  still  retaining  indications  of  their  primitively  double  nature. 
The  whole  test  is  regularly  covered  with  primary  tubercles,  and 
there  are  no  bare  bands  even  near  the  mouth,  at  which,  also,  the 
bourrelets  are  but  feebly  developed.  The  generalized,  or  feebly 
differentiated,  characters  of  the  form  arc  curiously  enough  spoken  to 
by  the  fact  that  nearly  all  naturalists  who  examined  it  hastily  thought 
that  they  had  seen  it  before  ;  one,  how^ever,  thought  he  had  a  specimen 
belonging  at  any  rate  to  the  same  genus ;  it  was  only  some  time 
after  the  reading  of  his  paper  that  Professor  Bell  was  enabled  to  see 
the  specimen  in  question  ;  of  this  he  has  since  given  a  sliort  account 
to  the  Zoological  Society,  and  we  are  enabled  to  say  that  he  tinds 
himself  compelled  to  regard  it  as  an  immature  specimen  of  the  more 
highly  specialized  genus,  Echinolampas.  If  this  be  the  correct  view, 
it  affoi'ds  another  example  of  the  resemblance  of  the  young  forms  of 
differentiated  species  to  the  adult  forms  of  less  differentiated  creatures, 
and  aids  in  compelling  us  to  accept  the  aphorism  :  "  The  development 
of  the  individual  is  a  compressed  epitome  of  the  history  of  the 
race." 

Fossil  Tertiary  Echini,  f — Dr.  Martin  has  arrived  at  tlie  very 
interesting  conclusion  that  a  considerable  percentage  of  these  fossil 
Echinids,  from  Java,  are  still  represented  in  the  Indian  Ocean ;  the 
tertiary  species  were  described  by  Herklots  as  new,  and  these  deter- 
minations the  present  writer  now  revises.  The  author  gives  a  valu- 
able table  of  the  species  found,  and  shows  what  arc  still  living,  and 
what  are  their  allies,  either  extant  or  fossil.  He  arrives  at  the 
important  result  that  even  in  the  tertiary  period  the  tropical  oceanic 
fauna  ajjpears  to  have  been  "quite  as  ilistinct  as  it  is  in  the  present 
day,  for  they  contain  no  fossils  which  have  yet  been  found  in  extra- 
tropical  tertiary  deposits.  This,  as  a  second  table  shows,  is  indicated 
also  by  other  groups  of  the  Invcrtebrata ;  but  in  none  perhaps  is  it 

•  'Proc.  Zool.  Roc.,'  1880,  p.  4H. 
+  '  Nolort  R.  Mils.  Nothcilnn<l8.'  ii   '  lx>^Ol  p  ~:i 
voT,.   in.  '2   r 


642  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

more  evident  than  with  tlie  Ecliiuoidea,  57  per  cent,  of  wliicb  are 
identical  in  the  present  time  and  in  tertiary  deposits ;  the  Crustacea, 
indeed,  give  a  percentage  of  67,  but  we  know  of  only  9  fossil 
species  of  this  order,  whereas  19  Echinoidea  have  been  discovered. 
6  Foraminifera,  1  Cephalopod,  and  1  Brachiopod  have  been  found 
fossil,  and  none  of  these  are  identical  with  recent  forms. 

Remarkable  Ophiurid.* — Herr  v.  Martens  gives  a  description  of 
a  new  species,  Opldotliela  cUvidua,  from  Algoa  Bay.  The  species  was 
six-rayed,  but  was  remarkable  for  the  fact  that  in  the  large  number  of 
specimens  examined,  the  arms  of  each  individual  were  always  unequal 
in  size,  and  that  the  longer  arms  all  lay  on  one  side  of  the  disk ; 
there  might  be  three  large  and  three  small,  or  two  large  and  four 
small  arms.  It  would  appear,  therefore,  that  the  creature  had  under- 
gone transverse  division,  and  that  the  smaller  arms  were  newly 
formed.  These  specimens  afford  some  support  to  the  doctrine  on 
Avhich  the  author  has  j^reviously  insisted  :  that  when  star-fishes  have 
more  than  five  arms,  it  is,  as  a  rule,  in  consequence  of  the  animal 
having  budded  them  off  after  division  or  injury. 

Mediterranean  Echinoderms.  f  —  In  the  present  essay,  Dr. 
Hubert  Ludwig  gives  a  brief  account  of  Antedon  pTialangium,  and 
points  out  the  differences  between  it  and  A.  rosacea  ;  and  of  Astropecten 
squamatus,  of  which  he  has  been  enabled  to  examine  Miiller  and 
Troschel's  type-sj)ecimen,  and  with  which  he  associates  Philippi's 
A.  aster.  He  then  describes  a  new  species  of  the  Ophiurida,  OpMoconis 
hrevispina,  of  which  genus  as  yet  only  two  species  were  known.  In 
giving  an  account  of  Thyone  aurantiaca  he  jioints  out  that  the  presence 
of  a  male  genital  papilla  appears  to  be  very  common  among  the  Deu- 
drochirotfe  ;  and  he  concludes  wdth  a  notice  of  a  Mediterranean  species, 
Holotliuria  mammata,  which  was  described  by  Grube  in  1840,  and 
appears  to  have  been  never  again  observed. 

Ccelenterata. 

Intracellular  Digestion  in  Coelenterata.J — Professor  Metschnikoff 
considers  that  this  phenomenon,  already  demonstrated  by  Jeffrey 
Parker  in  Hydra,  must  be  regarded  as  the  rule  in  most  of  the  true 
Coelenterates.  It  has  now  been  observed  in  the  Hydroids  Plunmlaria, 
Tubularia,  the  Hydromedusfe  Eucope,  Oceania,  Tiara,  as  the  intrusion 
into  the  endoderm  cells  of  solid  alimentary  particles  ;  also  in  Pelagia, 
Praya,  Forsluilia,  Hippopodius,  in  the  Ctenoj^horan  Beroe,  and  in  the 
Actinians  Sagarfia  and  Aiptasia  ;  it  has  not  been  noticed  in  the 
Trachymedusse.  In  the  Hydroidea  and  Oceanidfe  almost  the  whole 
endoderm  has  this  property  (in  Eucope  the  genital  organs,  the  wall  of  the 
circular  vessel,  and  the  base  of  the  tentacles  were  thus  penetrated),  but  it 
is  usually  limited  to  certain  cylindrical  thickenings;  in  the  Siphono- 
phora  it  is  exerted  only  by  the  thickenings  of  the  median  division  of 
the    stomach ;    in    Actinice   the   mesenteric   filaments   must    now   be 

*  '  SB.  Ges.  Natnrf.  Freund.  Berlin,'  1879,  p.  127. 
t  'Mitth.  Zool.  Stat.  Neapel,'  ii.  (18S0)  p.  53. 
X  '  Zool.  Anzeig.,'  iii.  (1880)  p.  261. 


INVEETEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  643 

regarded  as  digestive  organs  owing  to  the  same  ocenrrencc  in 
their  ordinary  entoderm  cells,  thus  explaining  Lewes  and  Kruken- 
berg's  observations  of  the  complete  absence  of  any  free  digestive 
secretion ;  on  the  other  hand,  the  Hert wigs'  interpretation  of  the 
abundant  gland-cells  which  abound  here,  must  be  rejected,  and  they 
must  be  regarded  instead  as  mucus- glands.  The  Coelenterate  ento- 
derm cells  are  ranked  among  the  araceboid  epithelia,  taking  in  as  they 
do,  their  food  by  pseudopodia-like  processes ;  this  is  well  seen  in 
Praya  diphyea,  whose  cells  are  long  and  envelope  food-particles  in  a 
Plasmodium,  formed  of  the  fused  pseudopodia  ;  a  similar  fusion  of  the 
ends  of  the  cells  occurs  in  the  Ctenophora  and  Adinice.  In  Cteno- 
phora  the  food-particles  pass  into  the  wandering  cells  of  the  mesoderm, 
as  in  sponges. 

Considering  that  representatives  of  all  the  chief  groups  exhibit 
this  phenomenon,  it  would  appear  to  be  a  primitive  endowment  of  the 
Ccelenterate  type,  and — the  same  being  the  case  with  the  lowest  worms, 
the  Turbellarians — also  of  the  Metazoa  in  primitive  times.  As  the 
method  does  not  demand  a  sjiecial  digestive  cavity,  this  last  would 
appear,  where  present,  to  be  of  secondary  origin. 

Probably  some  points  in  the  development  of  Coelenterata,  which 
as  yet  appear  at  variance  with  the  gastrsea-theory,  may  be  explained 
by  these  considerations. 

Nervous  System  of  Beroe.* — Dr.  Eimer  recajntulates  the  present 
condition  of  our  knowledge  of  the  nervous  arrangements  in  the 
Coelenterata.  He  points  out  that  in  an  earlier  work  he  had 
insisted  on  the  fact  that  the  nervous  system  of  Beroe  ovatus  was 
not  distinctly  localized,  but  was  represented  by  a  number  of  nerve- 
cells  which  were  distributed  over  the  whole  surface  of  the  body,  and 
were  numerous  only  in  the  region  of  the  anal  pole  ;  no  true  nerve- 
cords,  such  as  are  seen  in  the  higher  animals,  are  to  be  found  in  this 
Ctenophore.  Very  similar  results  have  been  shown  among  the  Meduste  ; 
here  there  is  a  lamellar  central  nervous  system  distributed  over  the 
body,  and  attaining  its  greatest  development  in  the  Craspedota  in  the 
region  of  the  margin  of  the  umbrella  (Cycloneura),  and  in  the  Acras- 
pedota  in  the  region  of  the  marginal  bodies  (Toponeura).  In  both 
these  groups  the  nervous  elements  may  be  frequently  connected  with 
the  epithelium.  In  these,  just  as  much  as  in  Beroe,  it  is  difficult  to 
distinguish  the  nerve-cells  as  morphological  elements,  but  this  is,  of 
course,  in  complete  agreement  with  the  a  priori  consideration  that 
characteristic  tissues  are  no  more  suddenly  developed  than  are  distinct 
fimctions.  Pliysiological  experiments  on  the  Medusa?  have  confirmed 
these  views  :  it  now  remains  to  apply  the  same  test  to  Beroe. 

Experiment  A. — Specimens  were  so  operated  on  as  to  divide  them 
into  three  equal  parts,  representing  rcspcctivuly  the  anal  polo,  the 
oral  pole,  and  the  median  portion  of  the  body ;  wlicn  this  was  done 
it  was  foinid  that  all  the  ctcnophores  ceasod  their  activity;  after  a 
sliort  time,  however,  this  again  reapi)eared  in  the  parts  connected 
with   the  anal  pole  ;  after  four   hours  nearly  all  the  parts  wore  in 

*  '  Ar.-l,.  Mikr.  Annt..'  xvii.  (Is7!))  p.  2VX 

2    r    2 


644  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

movement.  On  this,  small  pieces  were  cut  off  from  different  parts  of 
the  body ;  at  first  without  movement,  in  two  hours  after  they  were 
quite  active.  In  the  second  area,  exhibitions  of  movement  were  very 
common.  In  the  third,  all  the  parts  and  pieces  were  quite  active. 
In  the  median  portion  the  ctenophores  of  one  row  exhibited  a  contrary 
direction  to  the  rest.  These  experiments  conclusively  demonstrate 
that  parts  disconnected  from  the  anal  area  are  capable  of  independent 
movement. 

Experiment  B. — A  row  of  ctenophoral  plates  was  separated  by 
incision,  and  a  division  transverse  to  its  long  axis  at  a  distance  of 
about  2  centimetres  from  the  anal  pole  was  made  ;  for  a  moment  the 
movements  of  all  the  ctenophores  ceased ;  then  the  uninjured  plates 
began  to  move,  then  the  distal  portion,  and  last  of  all  the  proximal 
(oral)  portion  of  the  injured  plate  exhibited  activity.  In  the  last 
two  the  movements  were  independent  of  one  another.  These  experi- 
ments throw  into  marked  relief  the  extraordinary  capacity  which  the 
different  parts  of  the  injured  Beroe  have  of  performing  separate  move- 
ments, just  as  though  they  were  distinct  animals. 

The  author  further  found  that  the  movement  of  the  injured  animals 
was  in  the  same  direction  as  that  of  the  uninjured,  and  that  the  same 
power  of  direction  was  possessed  by  them  after  and  before  the  experi- 
ment. 

Looked  at  generally,  tliese  remarkable  observations  afford  con- 
clusive support  to  the  doctrine  that  the  "  central  region  "  at  the  apical 
pole  is  not  really  the  centre  of  the  nervous  energy  of  the  animal, 
while  they  show  that  nerve-cells  are  at  any  rate  scattered  over  the 
whole  of  the  body,  however  more  numerous  they  may  be  in  one  region, 
and,  moreover,  these  nerve-cells  may  be  functional  centres  for  any  given 
part  of  the  body.  The  facts  here  detailed  are  completely  paralleled 
by  the  results  already  obtained  from  the  study  of  the  Medusfe,  and  we 
may  safely  assert  that  "  a  distinctly  localized  central  nervous  system  is 
not  present  inBeroe;  its  central  cells  are  distributed  over  the  whole  body 
and  are  only  more  closely  aggregated  in  the  region  of  the  anal  pole." 

Pleurobrachia  pileus.* — In  a  few  notes  on  this  animal,  no 
specimen  of  which  was  found  in  a  sexually  mature  condition,  Herr 
Hartmann  points  out  the  presence  on  t^vo  lobes  of  two  roimd,  red, 
granular  pigment-spots  ;  these,  which  it  is  possible  were  rudimentary 
eyes,  are  not  to  be  confounded  with  the  ctenocyst,  or  auditory  vesicle. 
The  oesophagus-like  portion  of  the  digestive  canal  was  connected  with 
the  stomach  and  the  funnel  by  an  orifice  surrounded  by  a  circular 
projection,  and  provided  with  circular  and  longitudinal  muscles.  At 
the  oral  pole  he  detected  ganglia  which  gave  off  nerve-filaments  to  the 
ctenophoral  plates,  and  to  the  parenchyma  of  the  body,  and  which 
were  further  connected  with  one  another  by  transverse  commissures. 
The  branches  of  the  tentacles  were  beset  with  a  number  of  rounded 
tubercles,  between  which  there  was  diffused,  in  the  primary  portions 
of  the  tentacle,  a  reddish  pigment ;  these  tubercles  were  provided 
with  a  number  of  urticating  capsules. 

*  'SB.  Gcs.  niiturf.  Fromi.l.  B.rlin,'  1S79,  p.  25. 


INVERTEBKATA,    CEYPTOGAMIA,    MICROSCOPY,    ETC.  645 

Anatomy  and  Histology  of  the  Actiniae.* — In  continuation  of 
our  account  of  tlie  paper  of  the  brothers  Hertv\'ig,|  we  direct  attention 
to  their  history  of  Cerianthus,  Edicardsia,  and  Zoanthus,  which  is  not 
so  elaborate  as  the  preceding  portion. 

With  regard  to  Cerianthus,  the  most  important  observations  are 
those  which  deal  with  the  layer  of  muscles  subjacent  to  the  nervous 
system.  Forming  bnt  a  thin  layer  in  the  tentacles,  they  form  a  more 
considerable  stratum  in  the  oral  disk,  and  here  each  muscular  band 
has,  as  a  sujiporting  lamella,  a  thin  homogeneous  layer,  which  presents 
a  free  edge  towards  the  nervous  layer,  and  is,  as  compared  with  the 
same  part  in  the  Actinice,  much  better  developed.  In  the  tentacles 
the  elements  of  the  muscular  layer  are  isolated.  The  middle  layer  of 
the  body  is  distinguished  by  the  simplicity  of  its  characters,  and  the 
complete  absence  of  si)ecial  connective-tissue  cells.  The  endodcrm, 
also,  presents  points  of  diiierence,  for  its  cells  are  not,  as  in  the 
Actinice,  provided  with  a  single  flagellum,  but  with  a  tuft  of  delicate 
cilia.  Parasitic  cells  are  here  completely  absent.  The  a-sophagus 
is,  as  compared  with  that  of  the  Actinice,  extremely  short ;  there  is 
only  one  oesophageal  groove,  and  we  are  therefore  enabled  to  distinguish 
a  ventral  and  a  dorsal  aspect ;  when,  however,  we  inquire  which  is 
the  dorsal  and  which  is  tlie  ventral,  we  find  that  our  authors  are  in 
opposition  to  Haacke,"):  and  that  they  regard  the  side  on  which  the 
groove  is  developed  as  being  the  ventral  one.  In  the  walls  of  this 
oesophagus  there  is  developed  a  special  muscular  lamella.  The  septa 
of  Cerianthus  are  only  feebly  ditferentiated  from  one  another,  and  this 
simjjlicity  in  character  extends  even  to  their  histological  details.  After 
pointing  out  the  leading  characters  by  which  they  are  here  dis- 
tinguished from  the  Actinice,  the  writers  proceed  to  an  account  of  the 
generative  organs ;  these  are  very  numerous,  as  they  are  developed 
on  every  septum,  at  the  point  at  which  that  process  ceases  to  be 
invested  by  the  oesophagus ;  bath  ova  and  spermatozoa  may  be  found 
to  be  enclosed  in  a  capsule  of  connective  tissue,  and  the  testicular 
follicles  are  not  only  set  between  each  of  the  ovarian  but  are  also 
found  to  be  aggregated  into  special  bands. 

The  most  interesting  characters  in  Edicardsia  affect  the  important 
question  of  the  morphology  of  the  septa  ;  in  these  creatures  there  are, 
as  Quatrefuges  showed,  only  eight  septa ;  these  are  all  inserted  into 
the  Oisophagus,  and  they  are  all  extremely  muscular ;  they  aro 
arranged  in  an  exactly  symmetrical  relation  to  the  two  oesophageal 
grooves.  Contrary  to  what  obtains  in  all  allied  forms,  the  tentacles 
aro  not  numerically  similar  to  the  septa ;  in  other  words  there  aro 
more  than  eight,  and  the  number  present  is  not  even  always  a 
multiple  of  that  number. 

Passing  from  these  details  to  a  general  part,  the  authors  eommenoo 
with  a  chapter  on  the  classiticatiou  of  the  Ctelenterata ;  to  make  this 
cofuplete  they  aro  compelled,  after  dealing  with  the  systematic  rela- 
tions of  the  forms  already  described,  to  enter  upon  the  relations  of 
these  to  tlie  other  Anthozoa,  and   to  an  account  of  the  generative 

♦  'Jen.  Zcitsilir.  Nutiirwu^s..'  xiii.  (1S80)  p.  SfW.  t  -^ntc,  pp.  ^.')l-l:.7. 

X  Sec  this  Journal,  ii.  (.1879)  p.  8'J2. 


646  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

organs  of  the  Cliarabydoicla,  Discopliora,  and  Calycozoa  ;  into  these 
details  we  cannot  enter,  but  we  give  a  brief  resume  of  their  general 
conclusions.  Putting  aside  the  very  distinct  group  of  sponges,  it  is 
possible  to  divide  the  rest  of  the  Ccelenterata  into  two  great  gi'oups ; 
(1)  Ectocarpa,  (2)  Entocarpa ;  ia  the  latter  are  all  the  Anthozoa  and 
Acraspedota  (with  also  the  Charabydeida  and  Lucernarida),  and  in  the 
other  the  Hydromedusse  (including  the  Siphonophora)  and  the  Cteno- 
phora.  The  most  important  difference  between  these  two  groups  lies 
in  the  fact  that  in  the  former  the  generative  organs  are  derived  from 
the  ectoderm,  and  in  the  latter  from  the  endoderm  ;  in  one,  therefore, 
the  organs  are  exposed,  and  in  the  latter  they  are  placed  in  j)rocesses  of 
the  gastro-vascular  system.  Other  minor  differences  remain  to  be  noted  ; 
in  all  the  Entocarpa  the  matured  generative  products  lie  separately  in 
the  mesoderm  ;  in  the  Anthozoa  they  are  invested  by  fibrous  connective 
tissue,  and  in  the  Acraspeda  by  gelatinous  capsules.  This  is  not  the 
case  with  the  Ectocarpa.  Nor,  again,  is  the  mode  of  emission  similar 
in  the  two  divisions ;  in  the  Entocarpa  the  products  pass  into  the  gastro- 
vascular  system,  while  in  the  Ectocarpa,  with  the  possible  exception 
of  the  Ctenophora,  they  pass  directly  into  the  water.  The  two 
groups  may  be  thus  conveniently  and  succinctly  defined  : — 

The  Entocarpa  are  Ccelenterata,  in  which  the  generative  cells  are 
developed  in  the  endoderm,  and  pass  when  mature  into  the  mesoderm ; 
they  are  provided  with  a  special  secreting  apparatus  (the  mesenterial 
filaments). 

The  Ectocarpa  are  Ccelenterata,  in  which  the  generative  cells  are 
developed  in  the  ectoderm,  where  they  remain ;  they  do  not  possess 
any  mesenterial  filaments. 

Other  differences  may  be  noted  between  these  groups,  but  passing 
to  their  common  origin,  it  may  be  noted  that  the  original  ancestor 
was  doubtless  very  similar  to  Hydra,  though  somewhat  more  gene- 
ralized in  character,  and  with  a  much  less  marked  differentiation 
of  ectoderm  and  endoderm.  The  generative  products  had  no  defined 
seat  of  origin ;  when  this  began  to  obtain  two  distinct  phyla  were 
initiated ;  one  led  by  the  Hydroid  Polyps  to  the  Ctenophora,  the 
other  to  the  Scyphistoma-creatures,  in  which  the  generative  organs  had 
an  endodermal  origin,  and  in  which  the  gastric  cavity  was  interrupted 
by  four  longitudinal  septa ;  this  division  broke  up  into  the  Anthozoa 
and  the  Acraspeda. 

Some  few  points  as  to  the  histological  details  of  the  AdinicB 
remain  to  be  summed  up  : — 

(1)  The  organs  are  chiefly  developed  from  the  ectoderm. 

(2)  There  is  a  striking  similarity  between  the  histological  elements 
of  the  ectoderm  and  endoderm. 

(3)  The  neuro-muscular  system  is  made  up  of  three  sets  of  cells, 
muscular,  sensory,  and  ganglionic,  and  these  are  connected  into  one 
system  by  nerve-fibrils. 

(4)  The  muscular  fibres  seem  to  have  been  primitively  arranged 
in  lamellfe.  They  grew  inwards,  and  became  separated  into  bundles 
by  the  investing  connective  tissue. 

(5)  Where  no  special  optic  organb  arc  developed,  some,  at    any 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  647 

rate,  of  the  sensory  cells  of  the  ectoderm  must  be  sensitive  to  luminous 
imj)ressious. 

In  conclusion,  attention  is  directed  to  the  bearing  of  the  facts 
detailed  on  the  germ-lajer  theory.  The  authors  give  a  sketch  of  the 
change  in  thought  which  has  had  for  its  effect  to  give  a  general  mean- 
ing to  the  words  ectoderm,  endoderm,  and  mesoderm  ;  but  this  change 
has  hardly  been  completely  accurate.  Let  us  take  as  an  example  the 
term  mesoderm.  The  students  of  the  embryology  of  the  higher 
animals  apply  the  word  to  a  layer  of  embryonic  cells  ;  and  they  show 
that  these  cells  become  converted  into  definite  tissues  and  organs. 
On  the  other  hand,  in  the  Coelenterata,  the  word  is  applied  to  a 
definite  layer  of  tissue,  which  is  developed  between  the  inner  and 
outer  epithelial  layers.  The  matter  may  be  best  put  thus :  In 
the  lowest  divisions  of  the  Metazoa  there  are  only  two  layers,  the 
ectoblast  and  endoblast ;  in  the  higher  there  is  a  third  embryonic 
layer,  the  mesoblast.  These  three  terms  should  be  confined  to  the 
layers  of  the  embryo,  and  should  only  be  regarded  as  exhibiting  topo- 
graphical relations.  The  terms  endoderm,  &c.,  should  be  thus  used : 
By  endoderm  and  ectoderm  we  mean  the  outer  and  inner  layers  of 
the  developed  body,  which  have  been  developed  from  the  ectoblast 
and  endoblast  of  the  germ,  and  have  retained  their  jirimitive  position  ; 
the  term  mesoderm  is  applied  to  the  sum  of  all  the  tissues  and  organs 
which  are  interpolated  between  the  bounding  layers,  and  these  may 
be  cither  dcrivates  of  a  special  mesoblast,  or  have  taken  their  origin 
directly  from  one  of  the  two  primary  germ-layers.  With  these  defini- 
tions we  can  formulate  the  two  following  laws  : — 

(1)  As  an  animal  increases  in  complexity  of  organization  the  size 
and  complexity  of  the  mesoderm  increase,  while  the  ectoderm  and 
endoderm  become  more  simple.  In  the  Ccclenterata  the  ectoderm 
and  endoderm  fulfil  the  most  varied  functions  of  the  animal,  but  in 
the  rest  these  functions  are  taken  on  by  the  mesc  derm. 

(2)  All  the  organs  which  in  the  higher  orders  are  mesodermal, 
belong  in  the  lower  animals  (with  the  exception  of  the  vascular  system, 
&c. — direct  dcrivates  of  the  mesoderm)  to  the  two  primitive  cell- 
layers. 

The  facts  detailed  in  this  paper  would,  even  if  unsupported  by 
other  similar  facts,  be  suiTicicnt  to  demonstrate  that,  when  we  examine 
the  question  of  the  homology  of  the  layers  within  the  difiercnt 
divisions  of  the  animal  kingdom,  we  find  that  the  germ-layers 
undergo  different  kinds  of  differentiation.  This  docs  not  affect 
the  general  homology  of  the  layers ;  how  docs  it  bear  on  the  <|uestion 
whether  the  twu  layers  have  always  the  same  relations  to  the  tissues 
derived  from  them  ?  After  a  review  uf  a  number  of  tlie  facts  which 
bear  on  the  question,  the  autliors  come  to  the  conclusion  that  the 
germ-layers  are  neither  organ(dogical  nor  liistological  unities.  Wo 
cannot  argue  from  what  we  know  of  the  develoiunent  of  an  organ 
in  one  pliylum  as  to  its  history  in  another.*  The  steni-form — the 
gastriea — must  not  bo  regarded  as  orgauologically  and  histologically 
indifferent ;  its  descendants  may  have  had  tlieir  tissues  and  organs 
*  Compare  witli  this  M.  FolV  views,  mitr^  p.  (iO"). 


618  IvECOKL)    OF    CUIiKENT    RESEAKCUES   KELATJNG    TO 

diflferciitiated  in  various  ways ;  just  as  individual  cells  vary  iu  their 
characters,  so  too  may  the  germ-layers  give  rise  iu  various  ways  to 
the  tissues  and  organs.  The  work  now  to  be  done  is  to  define  for 
each  class  of  animals  (1)  how  the  primary  layers  of  ectoblast  and 
endoblast  are  converted  into  the  definite  layers  and  organs  ;  and 
(2)  how  the  cells  are  histologically  differentiated  in  the  separate 
layers. 

Structure  of  some  Coralliaria.*  —  Among  the  Coralliaria  the 
Actinioi  have  been  the  best  studied.  The  almost  total  deficiency 
of  facts  concerning  the  microscopical  structure  of  the  other  groujDS 
decided  M.  C.  Merejkowsky  to  undertake  a  special  study  of  some 
species  common  in  the  Bay  of  Naples.  The  following  are  his 
results. 

The  ectoderm  is  shown  to  consist  of  the  following  elements  : — 
1.  Ordinary  ectodermic  cells  of  very  elongated  form,  excessively 
depressed  and  dilated  at  the  upper  extremity  which  is  invariably 
furnished  with  only  a  single  cilium.  2.  Cells  like  the  last  but  trans- 
formed at  their  base  into  an  excessively  long  and  slender  filament, 
sometimes  provided  with  several  inflations  which  may  be  called  the 
nervous  Jilaments.  3.  Epithelio-muscular  elements  composed  of  cells 
like  the  first  (but  shorter  and  broader),  united  at  their  base  to 
musculai-  fibrillas.  4.  Nematocysts  of  two  kinds,  the  larger  ones  often 
surrounded  by  protoplasm  with  a  nucleus  and  a  long  filament  (nervous) 
in  the  posterior  part,  the  smaller  ones  of  a  different  form  and  always 
furnished  with  a  long  posterior  filament ;  the  filament  bears  at  j^laces 
small  knots.  5.  Glandular  cells  always  pyriform  and  with  coarsely 
granular  contents. 

The  mesoderm  is  an  elastic  and  structureless  membrane,  varying 
in  thickness  iu  the  different  parts  of  the  body.  It  forms  longitudinal 
protuberances  upon  the  faces  of  two  mesembryenthal  septa  which 
unite  at  the  surface  of  the  stomach.  The  muscles  which  spread  in  a 
single  layer  over  it  are  longitudinal  in  the  interior  of  the  animal  and 
disposed  in  horizontal  rings  on  the  exterior.  They  are  either  long, 
slightly  flattened  filaments,  the  relations  of  which  to  the  other  histo- 
logical elements  it  is  not  easy  to  ascertain,  or  they  are  fibrillfe  form- 
ing a  part  of  the  ej)ithelio-muscular  elements. 

Another  very  citrious  element  consists  of  cells  of  comparatively 
large  size,  and  excessively  flattened,  which  ramify  greatly  and  unite 
with  each  other  by  their  ramifications,  and  are  filled  with  granular 
contents,  with  nucleus  and  nucleolus.  They  are  arranged  in  a  layer 
and  rest  immediately  upon  the  outer  surface  of  the  elastic  membrane. 
From  their  form,  habit,  and  position,  the  author  has  no  doubt  but 
that  they  are  nervous  ganglia  in  which  the  numerous  fibrillse  of  the 
different  ectodermic  cells  terminate. 

The  entoderm  is  composed  almost  exclusively  of  very  typical 
epithelio-muscular  cells.  The  epithelial  cell  is  not  so  strongly 
elongated  as  in  the  ectoderm,  but  Avith  the  base  much  dilated,  and 
with  a  single  cilium  at  the  extremity.     The  muscular  fibril  is  very 

*  '  Comi'tcs  Eeudus/  xc.  (1880)  p.  1086. 


mVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  649 

refractive,  fusiform,  and  nearly  tlircc  times  as  long  as  the  coll  itself. 
Glandular  cells  not  essentially  diftering  from  those  above  described 
are  also  met  with. 

Mesembryenthal  Filaments. — ^The  surface  of  the  stomach  is  not 
smooth,  but  covered  with  longitudinal  elevations,  very  rich  in 
glandular  cells,  each  of  which  corresponds  to  the  place  where  a 
septum  unites  with  the  stomach.  At  the  extremity  of  the  stomach 
the  protuberances  form  the  free  edges  of  the  mesembryenthal  septa ; 
there  is  therefore  an  unbroken  continuity  of  these  longitudinal  pro- 
tuberances at  the  surface  of  the  stomach  with  the  mesembryenthal 
filaments,  and  this  fact  explains  the  complete  unity  in  the  structure 
of  these  two  organs  and  shows  that  they  can  only  act  as  an  organ  of 
digestion.  The  filaments  are  solid,  and  have  no  interior  cavity. 
There  is  no  canal  passing  through  the  septa  and  uniting  the  chambers 
formed  by  them. 

Antipatharia  of  the  '  Blake  '  Expedition.* — Twelve  species  of 
this  interesting  group  taken  in  the  Caribbean  Sea  (1878-79)  are 
described  by  L.  F.  Pourtalcs.  In  determining  the  species  an  attempt 
has  been  made  to  use  the  diftcrences  in  the  shaj)e  of  the  polyps,  as 
well  as  the  disposition  and  form  of  the  sjjines,  to  draw  characters  for 
a  much-needed  revision  of  their  classification.  It  would  seem  as  if 
there  were  at  least  two  difterent  types  of  spines  ;  the  triangular  com- 
pressed and  the  more  cylindrical.  These  latter  are  generally  more 
densely  set,  even  assuming  sometimes  a  brush-like  appearance,  as  in 
Antipathes  humilis,  a  new  and  wonderfully  spinous  species,  figured  but 
not  described.  These  cylindrical  spines  are  also  unequal  on  the  two 
sides  of  the  pinnules,  being  longer  on  the  side  occupied  by  the  polyps, 
with  a  few  very  mucli  longer  around  the  polyi^s.  In  one  species,  how- 
ever, A.  Dcshonni,  the  spines  are  in  regular  verticils.  There  would  appear 
to  be  a  connection  between  the  shape  of  the  polyps  and  the  shape  and 
dis2>osition  of  the  spines.  Those  si)ecies  with  triangular  spines  have 
polyps  with  longer  tentacles  than  those  with  cylindrical  spines,  and 
the  tentacles  have  a  greater  tendency  to  become  regular  in  shape.  In 
many  sjiecies  the  tentacles  are  simply  contracted ;  in  a  very  few  they 
were  found  retracted,  as  figured  by  Lacaze-Dutliiers ;  and  in  somo 
they  arc  probably  not  retractile  at  all. 

Eight  out  of  the  twelve  named  are  cither  desci'ibed  or  figured  as 
new  species.  A.  spiralis  is  a  very  interesting  si)ccies,  formerly 
referred  to  A.  Dcshuiini  D.  and  M.  The  polyps  are  alternately  largo 
and  small,  with  very  large  digitiform  tentacles  much  longer  than  have 
been  figured  of  any  Antipdlhes  before.  In  the  spaces  between 
successive  polyps  the  ccenosarc  shows  transverse  canals,  and  those  ou 
the  back  part  of  the  branch  are  more  transparent  than  the  rest. 

American  Siphonophora.f — Mr.  J.  W.  Fewkcs  gives  a  sketch  of 
the  developuuiit  of  the  tentacular  knob  of  Phijsophora  hifdrcslafica. 
Tho   growth  of   this   knob   is   here    more  complicated   tlian    in   any 

»  'IJull.  'Slws.  Comp.  Zof.l.  Camb.,'  vi.  (1880)  p.  US.  Sec  'Nature,'  xxii. 
(1880)  p.  IKl 

t  Il'i.l..  p.  127.     Stc  'Nuluro.'  xxii.  (1880)  p.  11:5. 


650  RECORD    OP   CURRENT    RESEARCHES   RELATING   TO 

other  Siplionophoro  ;  commencing  as  a  bud  on  the  ciliated  base  of  the 
feeding  polyp,  it  is  at  first  only  composed  of  an  ectoderm  and  cndo- 
derm.  The  ectodermic  wall  divides  into  two  layers  and  gives  rise 
to  the  involucrum ;  within  this  the  sacciilns  becomes  coiled  np,  and 
shortly  appears  as  a  complicated  organ  armed  with  lasso-cells ;  mean- 
while the  basal  jjortion  becomes  so  enlarged  as  to  give  an  asymmetrical 
form  to  the  whole  knob.  As  the  fully  grown  stage  is  reached,  this 
enlargement  forms  a  simjile  tube  along  the  side  of  the  knob,  and  tho 
complete  condition  is  arrived  at.  It  is  interesting  to  note  that  in  some 
allied  genera  we  find  arrangements  of  the  parts  of  the  knob  which 
are  only  temjjorary  in  the  species  under  description. 

The  mantle-tubes  of  Apolemia  uvaria  and  Gleha  h'ppopus  are  also 
described,  and  the  tubes  in  the  larger  necto-calyx  of  Abyla  pentagona  ; 
he  adds  some  critical  remarks  on  the  genera  Halistemma,  Agalma,  and 
Agalmopsis,  and  concludes  with  a  notice  of  the  forms  of  Siphonophora 
and  VelellidiB  to  be  met  with  on  the  eastern  coast  of  the  United 
States. 

Up  to  the  present  few  forms  of  either  of  these  groups  have  been 
described  from  American  waters.  They  seem  to  be  only  occasional 
visitors  blown  into  the  neighbourhood  from  mid-ocean,  and  brought 
there  from  the  tropics  by  the  Gulf  Stream.  The  wealth  of  such 
species  that  one  meets  with  in  the  Mediterranean  is  unknown  on  the 
New  England  coast;  while,  as  the  author  says,  in  one  day  at  Nice  he 
has  taken  eight  different  genera  of  Siphonophora,  yet  at  Newport  he 
has  but  rarely  taken  as  many  as  two  genera  in  the  length  of  a 
summer's  day,  and  a  whole  summer  once  passed,  during  most  of  which 
he  was  almost  daily  on  the  water  without  one  species  being  seen. 
One  or  two  species  of  Phijsalia  are,  however,  more  common  on  the 
United  States  coasts  than  in  the  Mediterranean. 

The  only  member  of  the  long-stemmed  Siphonophora  provided 
with  a  float  or  air-bladder  found  heretofore  on  the  New  England 
waters  is  Agalmopsis  cara.  Mr.  Fewkes  can  now  add  A.  elegans,  and 
he  thinks  that  extended  observation  in  the  southern  bays  of  the 
country  will  bring  to  light  some  of  the  well-known  forms  common  to 
all  oceans,  such  as  Apolemia,  Ahyla,  Phijsophora,  and  Gleha.  Some  of 
these  have  already  been  taken  in  the  Gulf  of  Mexico  and  the 
Caribbean  Sea.  Bhizophysa,  found  in  the  same  localities,  might  also 
be  expected  to  be  brought  to  Eastern  American  coasts  by  oceanic 
currents. 

Origin  and  Development  of  the  Ovum  in  Eucope  before  Fecunda- 
tion.*— This  subject  has  been  studied  by  C.  Merejkowsky,  who  gives 
the  following  as  the  results  of  his  researches.  The  ovaries  of  the 
Medusa,  in  the  interior  of  the  bell,  have  the  appearance  of  four  small 
sacs,  due  to  an  evagination  of  the  gastro-vascular  cavity.  In  the 
walls  of  the  ovaries,  from  without  inwards  we  find  a  layer  of 
ectodermic  cells,  the  limits  of  which  are  not  well  defined,  and  the 
entoderm  composed  of  several  layers  of  better  defined  cells.  Tho 
innermost  layer  of  the  entoderm,  that  which  covers  the  inner  surfiice 

*  '  Comptes  Remliit^,'  xc.  (1880)  p.  1012. 


INVEBTEBRITA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  651 

of  the  ovtiiy,  is  composed  of  the  same  cells  (furnished  with  a  vibratilc 
cilium)  as  the  eutoclerm  of  the  radial  canals. 

Towards  the  base  of  the  ovary,  where  it  becomes  confounded  with 
the  lower  surface  of  the  bell,  the  entodermic  layer  is  as  yet  only 
formed  of  a  single  stratum,  as  in  the  radial  canal ;  but  in  proportion 
as  we  advance  towards  the  interior  of  the  ovary  we  see  the  entodermic 
cells  divide  in  a  direction  perpendicular  to  their  length,  and  thus  form 
two  superposed  layers  of  entoderm  ;  the  division  of  the  cells  continuing 
in  all  directions,  we  thus  hud  the  entoderm  grow  thicker  and  thicker. 

Between  these  two  lamellaB  of  entoderm  and  ectoderm  forming  the 
ovary,  is  a  third  more  delicate,  structureless  lamella — the  intermediate 
lamella — sharply  separating  them  and  assisting  us  to  define  with 
certainty  which  layer  produces  the  ova.  These  ova  are  always  found 
under  the  intermediate  lamella,  and  being  thus  separated  from  the 
ectoderm  by  that  lamella  can  only  be  developed  from  the  entoderm. 
This  is  further  borne  out  by  observing  directly  all  the  graduated 
transitions  between  the  ordinary  entodermic  cells  of  the  young  ova. 
The  changes  in  an  entodermic  cell  destined  to  be  developed  into  an 
ovum  consist  in  the  increase  of  the  vohime  of  this  cell  and  the  trans- 
formation of  the  nucleus  into  a  germinal  spot. 

In  the  entodermic  cells  lining  the  radial  canals  the  protoplasm  is 
perfectly  transparent  and  devoid  of  granules  ;  the  nucleus  appears  as  a 
clear  round  spot  containing  a  central  round  and  denser  nucleolus. 
The  cells  with  their  nuclei  and  nucleoli  subsequently  increase  in  size, 
and  the  protoplasm  becomes  more  and  more  granular.  The  nucleolus, 
at  first  simple  and  furnished  with  a  small  vacuole,  commences  to 
divide.  It  lengthens,  becomes  constricted  in  the  middle,  curves  into 
the  form  of  a  horse-shoe,  and  finally  divides  into  two  parts,  each 
possessing  a  central  vacuole  ;  each  half  again  divides  into  two  parts, 
but  in  a  direction  perpendicular  to  the  first,  and  so  on. 

These  phenomena,  constant  and  normal  in  the  Medusfe  of  the 
White  Sea,  are  the  exception  in  those  from  the  Bay  of  Naples.  In 
the  latter  the  division  of  the  nucleus  takes  place  in  a  different 
manner.  AV^hen  the  nucleolus,  after  elongation,  presents  a  median 
constriction,  it  does  not  divide  into  two  parts,  but  simi)ly  elongates  in 
the  form  of  a  band  twisted  upon  itself;  constrictions  then  foi-ming  at 
several  parts,  it  becomes  a  long  moniliform  ribbon  rolled  up  in 
several  turns.  Each  division  of  the  chaplet  is  fusiform  and  round ; 
it  regularly  contains  in  the  middle  a  very  small  vacuole,  and  is 
united  to  tlio  neighbouring  divisions  by  a  thin  and  sometimes  rather 
long  articulation.  Sometimes  tliis  band,  which  reminds  us  of  tlio 
nucleus  of  some  of  the  Infusoria  (Sicnior,  Sjnrosttimnm),  splits  into  two. 
Finally  the  articulations  of  the  chaplet  separate,  and  instead  of  a 
nucleolus,  there  is  formed  at  the  centre  of  the  nucleus  a  group  of 
several  dozens  of  small  round  balls  which  collect  into  a  si)hero  placed 
at  simic  distance  from  the  walls  of  tlie  nucleus.  These  balls  continue 
to  divide  until  they  reach  several  hundreds  in  number.  During  all 
this  time  the  ovum  enlarges  and  attains  its  definitive  diameter,  which 
surpasses  nearly  twenty  times  that  of  tho  entodermic  cells  from  wliicli 
it  originates. 


652  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

The  perfectly  mature  ovum  before  fecundation  presents  the  aspect 
of  a  sphere  of  granular  protoplasm  with  a  central  and  perfectly 
uniform  nucleus  showing  not  the  slightest  trace  of  a  nucleolus.  The 
hundreds  of  granules  into  which  the  nucleolus  has  been  divided  have 
been  dissolved  in  the  protoplasm  of  the  nucleus. 

Proportion  of  Water  in  the  Medusae.*  —  Dr.  Ki-ukenberg  has 
already  shown  that  a  large  specimen  of  Hldzostoma  Cuvieri  contained 
95*  392  per  cent,  of  water,  with  1  •  608  of  organic  and  3  •  0  of  inorganic 
substances.  In  order  to  test  the  statement  of  Mobius  that  Aurelia 
aurita  from  the  Bay  of  Kiel  had  been  found  on  analysis  to  contain 
99*82  per  cent,  of  water— a  proportion  leaving  the  solid  materials  at 
only  Jg-  of  the  amount  determined  in  a  Triest  specimen — a  single 
specimen  of  the  same  species  was  analyzed,  and  also  two  other  Aurelice 
together.  The  result  showed  the  solid  matters  to  exist  in  the  pro- 
portion of  from  4 '21  to  4' 66  jier  cent.,  the  water  in  that  of  from 
95 '34  to  95*79.  Chrysaora  hyoscella  gives  between  95*75  and 
96*3  per  cent,  of  water,  and  from  3*7  to  4*25  of  solid  bodies.  Pro- 
bably most  other  Medusae  agree  with  those  selected  in  these  points, 
so  that  no  marine  animal  exists  having  the  large  proportion  of  99*8 
per  cent,  of  water  as  a  constituent  of  its  tissues. 

A  Fresh-water  Hydroid  Medusa. — One  of  the  most  startling 
zoological  discoveries  of  recent  years  was  made  in  June  last  in  the 
warm-water  tank  in  which  the  Victoria  regia  is  grown  at  the  gardens 
of  the  Eoyal  Botanical  Society,  London.  The  water  (which  has  a 
temperature  of  85°  to  90°  F.)  was  found  by  Mr.  Sowerby  to  be 
literally  swarming  with  little  Medusfe  of  a  new  genus,  about  ^  inch 
in  transverse  diameter.  No  true  fresh-water  Medusa  has  hitherto 
been  known,  the  one  living  in  the  discharging  canal  of  the  Cette 
salt-works  t  being  the  most  recent  case  of  the  discovery  of  a  species 
not  actually  inhabiting  the  sea. 

The  Medusae  were  examined  by  Professor  Allman,  and  subsequently 
by  Professor  Lankester,  and  were  described  by  the  former  under  the 
name  of  Limyiocodium  victoria  (Xifivrj,  a  pond,  and  kojSwj/,  a  bell)  in  a 
paper  read  at  the  meeting  of  the  Linnean  Society  on  Jime  17,  and  by 
the  latter  as  Craspedacustes  Sowerhii  (in  allusion  to  the  relation  of  its 
otocysts  to  its  velum)  at  the  Eoyal  Society  on  the  same  day. 

From  Professor  Allman's  paper  J  we  extract  the  following  : — 

The  Medusae  are  very  energetic  in  their  movements,  swimming 
with  the  characteristic  systole  and  diastole  of  their  umbrella,  and  in 
the  warm-water  tank  were  apparently  in  the  very  conditions  which 
contributed  most  completely  to  their  well-being. 

The  umhreUa  varies  much  in  form  with  its  state  of  contraction, 
passing  from  a  somewhat  conical  shape  with  depressed  summit  through 
figiu-es  more  or  less  hemispherical  to  that  of  a  shallow  cup  or  even  of 
a  nearly  flat  disk.  Its  outer  surface  is  covered  by  an  epithelium 
composed  of  flattened  hexagonal  cells  with  distinct  and  brilliant 
nucleus. 

*  '  Zool.  Auzcig.,'  iii.  (1880)  p.  306.  t  See  tliis  Journal,  ii.  (1879)  p.  582. 

j  'Nature;  xxi.(li-80)  p.  178. 


INVERTEBRATA,    CRYPTOGAMIA,   MICROSCOPY,    ETC.  653 

The  manubrium  is  large  ;  it  commences  with  a  quadrate  base,  and 
when  extended  projects  beyond  tlie  margin  of  the  umbrella.  The 
mouth  is  destitute  of  tentacles,  but  is  divided  into  four  lips,  which 
are  everted  and  plicated.  The  endoderm  of  the  manubrium  is  thrown 
into  four  strongly-marked  longitudinal  plicated  ridges. 

The  radial  canals  are  four  in  niunber ;  they  originate  each  in  an 
angle  of  the  quadrate  base  of  the  manubrium,  and  open  distally  into 
a  wide  cii'cular  canal.  Each  radial  canal  is  accompanied  by  longi- 
tudinal muscular  fibres,  which  spread  out  on  each  side  at  the  junction 
of  the  radial  with  the  circular  canal. 

The  velum  is  of  moderate  width,  and  the  extreme  margin  of  the 
umbrella  is  thickened  and  festooned,  and  loaded  with  brownish-yellow 
pigment-cells. 

The  attachment  of  the  tentacles  is  peculiar.  Instead  of  being  free 
contrnuations  of  the  umbrella  margin,  they  are  given  off  from  the 
outer  surface  of  the  umbrella  at  points  a  little  above  the  margin. 
From  each  of  these  points,  however,  a  ridge  may  be  traced  centri- 
fugally  as  far  as  the  thickened  umbrella  margin ;  this  is  caused  by 
the  proximate  portion  of  the  tentacle  being  here  adnate  to  the  outer 
surface  of  the  umbrella.  It  holds  exactly  the  position  of  the  "  Man- 
telspangen "  or  peronia,  so  well  developed  in  the  whole  of  the 
NarcomedusaB  of  Haeckel,  and  occurring  also  in  some  genera  of  his 
Trachomedusae.  Its  structure,  however,  diifers  from  that  of  the  true 
peronia,  which  are  merely  lines  of  thread-cells  marking  the  path 
travelled  over  by  the  tentacle,  as  the  insertion  of  this  moved  in  the 
course  of  metamorphosis  from  the  margin  of  the  umbrella  to  a  point 
at  some  distance  above  it,  while  in  Limnocodium  the  ridges  are  direct 
continuations  of  the  tentacles  wliose  structure  they  retain.  They 
become  uaiTower  as  they  approach  the  margin.  The  number  of  the 
tentacles  is  very  large  in  adult  specimens.  The  four  tentacles  which 
correspond  to  the  directions  of  the  four  radial  canals  or  the  perradial 
tentacles  are  the  longest  and  thickest.  The  quadrant  which  intervenes 
between  every  two  of  these  carries,  at  nearly  the  same  height  above 
the  margin,  about  thirteen  shorter  and  thinner  tentacles,  while 
between  every  two  of  these  three  to  five  much  smaller  tentacles  are 
given  ofi"  from  points  nearer  to  the  margin,  and  at  two  or  three  levels, 
but  without  any  absolute  regularity ;  indeed,  in  the  older  examples 
all  regularity,  except  in  the  primary  or  perradial  tentacles,  seems 
lost,  and  the  law  of  their  sequence  ceases  to  be  apparent. 

No  indication  of  a  cavity  could  bo  found  in  the  tentacles  ;  but 
they  do  not  present  the  peculiar  cylindrical  chorda-like  endodcrmal 
axis  formed  by  a  series  of  large,  clear,  thick-wallod  cells  which  is  so 
characteristic  of  the  solid  tentacles  in  the  Trachomedusrc  and  Narco- 
mcdusa).  From  tlie  solid  tentacles  of  these  orders  they  ditfer  also 
in  their  great  extensibility,  the  four  perradial  tentacles  admitting  of 
extension  in  the  form  of  long,  greatly  attenuated  filaments  to  many 
times  the  height  of  tlie  vertical  axis  of  the  umbrella,  even  when  this 
height  is  at  its  maxiumm  ;  and  being  again  cajjablo  of  assuming  by 
contraction  the  form  of  short  thick  clubs.  Indeed,  instead  of  pre- 
r,((nting  the  Cdiuparatively  rigid  ami  imperfectly  contractih;  character 


654  KECOIID    OF    CURRENT    RESEARCHES    RELATING    TO 

which  prevails  among  the  Traehomedusa?  and  the  Narcomcdusae,  they 
possess  as  great  a  power  of  extension  and  contraction  as  may  be  found 
in  the  tentacles  of  many  Leptomeduste  (Thanmantidas,  &c.).  These 
four  perradiate  tentacles  contract  independently  of  the  others,  and 
seem  to  form  a  different  system.  All  the  tentacles  are  armed  along 
their  length  with  minute  thread-cells,  which  are  set  in  close,  somewhat 
spirally  arranged,  warts. 

The  lithocysfs  or  marginal  vesicles  are,  in  adult  specimens,  about 
128  in  number.  They  are  situated  near  the  umbrellar  margin  of  the 
velum,  between  the  bases  of  the  tentacles,  and  are  grouped  somewhat 
irregularly,  so  that  their  number  has  no  close  relation  with  that  of 
the  tentacles.  They  consist  of  a  highly  refringent  spherical  body, 
on  which  may  be  usually  seen  one  or  more  small  nucleus-like  cor- 
puscles, the  whole  surrounded  by  a  delicate  transparent  and  structure- 
less capsule.  This  capsule  is  very  remarkable,  for  instead  of  pre- 
senting the  usual  spherical  form,  it  is  of  an  elongated  pyriform  shape. 
In  its  larger  end  is  lodged  the  spherical  refringent  body,  and  it  thence 
becomes  attenuated,  forming  a  long  tubular  tail-like  extension  which 
is  continued  into  the  velum,  in  which  it  rims  transversely  towards  its 
free  margin,  and  there,  after  usually  becoming  more  or  less  convo- 
luted, terminates  in  a  blind  extremity. 

The  marginal  nerve-ring  can  be  traced  running  round  the  whole 
margin  of  the  umbrella,  and  in  close  relation  with  the  otolitic  cells. 
Ocelli  are  not  present. 

The  generative  sacs  are  borne  on  the  radiating  canals,  into  which 
they  open  at  a  short  distance  beyond  the  exit  of  these  from  the  base 
of  the  manubrium.  They  are  of  an  oval  form,  and  from  their  point 
of  attachment  to  the  radial  canal  hang  down  free  into  the  cavity  of 
the  umbrella.  Some  of  the  specimens  examined  contained  nearly 
mature  ova,  which,  under  compression,  were  forced  from  the  sac 
through  the  radial  canal  into  the  cavity  of  the  stomach. 

While  some  of  the  characters  described  above  point  to  an  affinity 
with  both  the  Trachomedusfe  and  Narcomedusfe,  this  affinity  ceases 
to  show  itself  in  the  very  important  morphological  element  afforded 
by  the  marginal  bodies.  In  both  Trichomedusfe  and  Narcomedusse 
the  marginal  bodies  belong  to  the  tentacular  system  ;  they  are  meta- 
morphosed tentacles,  and  their  otolite  cells  are  endoderraal,  while  in 
the  Lcptomedusfe,  the  only  other  order  of  craspedotal  Medusae  in 
which  marginal  vesicles  occur,  these  bodies  are  genetically  derived 
from  the  velum.  Now  in  Limnocodium  the  marginal  vesicles  seem  to 
be  as  truly  velar  as  in  the  Leptomedusae.  They  occur  on  the  lower 
or  abumbral  side  of  the  velum,  close  to  its  insertion  into  the  umbrella, 
and  the  tubular  extension  of  their  capsule  runs  along  this  side  to  the 
free  margin  of  the  velum,  while  the  delicate  epithelium  of  the  abum- 
bral side  passes  over  them  as  in  the  Leptomedusa3.  It  is  true  that 
this  point  cannot  be  regarded  as  settled  until  an  opportunity  of 
tracing  the  development  is  afforded ;  but  in  very  young  specimens 
which  Professor  Allman  examined  he  found  nothing  opposed  to  the 
view  that  the  marginal  vesicles  were  derived,  like  those  of  the 
Lcptomedusa",  from  the  velum. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  655 

If  tliis  be  the  case,  Limnocodium  will  hold  a  position  iutermetliate 
between  the  Leptomeclusce  and  the  TrachomedusEe  ;  but  as  the  greatest 
systematic  importance  must  be  attached  to  the  structure  and  origin 
of  the  marginal  vesicles,  ils  affinity  with  the  Leptomedusa3  must, 
Professor  Allman  considers,  be  regarded  as  the  closer  of  the  two. 

Professor  Lankester  *  considers  that  the  animal  is  one  of  the  sub- 
class Hydromedusas  or  Medusfe  craspedotae,  and  presents  the  common 
characters  of  the  order  Trachomedusfe  (as  distinguished  from  the 
Narcomedusas)  in  having  its  genital  sacs  or  gonads  placed  in  the 
course  of  the  radial  canals.  It  agrees  with  all  Tracholina2  (Tracho- 
medusai  and  Narcomedusa))  in  having  endodermal  otocysts,  and  it 
further  exhibits  the  solid  tentacles  with  cartilaginoid  axis,  the  centri- 
petal travelling  of  the  tentacles,  the  tentacle  rivets  (Mantelspangen), 
the  thickened  marginal  ring  to  the  disk  (Nessel  ring)  observed  in 
many  Tracholinre. 

Amongst  Trachomcdusae,  it  finds  its  place  in  the  Petasida),  which 
are  characterized  as  "  Trachomedusfe  with  four  radial  canals,  in  the 
course  of  which  the  four  gonads  lie,  with  a  long  tubular  stomach  and 
no  stomach-stalk." 

Amongst  Petasidaa  it  is  remarkable  for  the  great  number  of  its 
tentacles,  which  are  all  solid  ;  and  for  its  very  numeroiis  otocysts. 
Further,  it  is  remarkable  among  all  Hydromedusfe  (velato  Medusas, 
that  is,  exclusive  of  Charyhtlcea)  for  the  fact  that  centrifugal  radiating 
canals  pass  from  the  otocysts  into  the  velum,  where  they  end  ccecally." 

The  characters  of  the  genus  are  given,  and  it  is  pointed  out  that 
the  presence  of  velar  otocystic  canals  constitutes  the  chief  peculiarity 
of  the  genus,  and  may  necessitate  the  formation  of  a  distinct  family 
or  sub-order  for  its  reception.  The  sole  character  which  can  be 
given  as  specific  over  and  above  the  generic  characters  is  that  of  size. 
The  diameter  of  the  disk  does  not  exceed  one-third  of  an  inch. 

It  is  exceedingly  difficult  to  trace  the  introduction  of  the  animal 
into  the  tank  in  the  Regent's  Park,  since  no  plants  have  been  recently 
(within  twelve  months)  added  to  the  lily-house,  and  the  water  is  run 
off  every  year.  Probably  a  few  specimens  were  last  year  or  the  year 
before  i)reseiit  in  the  tank,  and  have  only  this  year  multiplied  in 
sufficient  abundance  to  attract  attention.  Clearly  this  Medusa  is  a 
tropical  species,  since  it  flourishes  in  water  of  the  high  tem])craturo 
of  DO^  Falir.  Mr.  Sowerby  has  observed  it  feeding  on  JJaphnia, 
which  abounds  in  the  water  with  it. 

Professor  Lankester  sul)sequeutly  published  t  a  fuH  prelirainaiy 
memoir  of  the  animal,  illustrated  by  woodcuts  and  jdatcs,  in  which  ho 
shows  that,  contrary  to  the  conclusion  of  Professor  Allman,  the  ten- 
tacles of  Limnocodium  do  resemble  those  of  the  Tnu-hyliuu  IMedusa) 
in  their  insertion  and  in  the  possession  of  true  (tliough  rudiniuiitury) 
pcronia,  also  that  the  statement  that  the  so-called  litliocysts  or 
marginal  bodies  have  essentially  tlie  saniu  structure  as  those  of 
Tracliyline  IMcdusai  (being  modified  tentacles  with  an  endodonnal 
axis)  is  warranted  by  their  develoinnental  history.  Consequently  ho 
adheres  to  the  original  determination  of  the  affinities  of  the  new 
*  L.K^'.  fit.,  J..  U7.  t  '  <i"iiil.  Joiini.  Mi.T.  Sci.,'  xx.  (ISSO)  p.  :r.|. 


656  RECORD   OF    CURRENT   RESEARCHES   RELATING    TO 

Medusa  as  one  of  the  Tracliomedusns,  thougli  it  is  quite  a  jieculiar 
form,  and  very  possibly  is  either  the  isolated  representative  of  an 
archaic  type  of  that  order  or  has  degenerated  in  connection  with  its 
exceptional  life-conditions — those  of  fresh  water. 

Professor  Lankester  is  fully  satisfied  that  Limnocodium  develops 
directly  from  the  egg.  When  specimens  are  kept  living  in  a  glass 
jar  under  constant  observation  it  is  found  that  exceedingly  small 
specimens  make  their  appearance  amongst  the  larger  ones.  The 
youngest  which  he  has  seen  at  present  measured  only  -^^  inch  in 
diameter,  and  others  were  under  observation  very  little  larger. 
The  smallest  was  of  a  subspherical  form,  without  any  aperture  to  the 
ectodermal  investment.  Four  minute  tentacles  were  sprouting  near 
one  pole  of  the  spherical  body,  and  between  these  rudiments  of  four 
others  were  seen.  Within  —  the  sub-umbrellar  musculature  was 
already  developed  and  contracting  at  intervals.  The  four  radial 
canals  were  also  present,  and,  what  is  more  remarkable,  the  sub- 
umbrellar  cavity  was  already  well  marked,  and  within  it  the  manu- 
brium with  the  oral  aperture.  Yet  the  margin  of  the  umbrella  was 
still  closed  by  a  continuous  ectodermal  coat  which,  when  perforated, 
would  become  the  velum. 

These  minute  embryos  correspond  very  closely  in  appearance 
with  the  embryos  of  the  well-known  typical  Trachomedusan  Geryonia, 
as  figured  by  Metschnikoff.*  They  leave  no  possibility  of  supi)osing 
that  Limnocodium  has,  like  most  Leptomedusfe,  a  hydroid  trophosome. 
In  respect  of  its  development  as  in  other  respects,  Limnocodium  is  not 
more  closely  allied  to  the  Leptomedusae  than  to  the  TrachomedusEe, 
but  is  one  of  the  Trachomedusge. 

A  remarkable  fact  which  is  not  yet  explained,  is  the  excessive 
rarity  of  females.  All  the  specimens  which  Professor  Lankester 
examined  have  been  males.  Females  clearly  enough  must  be  present, 
or  have  been  present  among  the  shoals  of  males — wlicnce  the  embryos 
discovered  by  Mr.  Sowerby.  It  is  a  known  fact  among  Trachyline 
Medusae  that  in  some  species  males  are  excessively  abundant,  and 
even  in  some  sj)ecies  females  have  never  been  detected.  Thus  again 
Limnocodium  agrees  with  the  Trachyline  Medusae. 

The  exceedingly  important  fact  that  some  of  the  Coelentera  and 
lower  kinds  of  worms  digest  their  solid  food  by  the  inception  of  the 
solid  food-particles  into  the  substance  of  endodermal  cells,  each  cell 
behaving  as  an  Amoeha,  has  now  been  fairly  established  by  the  observa- 
tions of  AUman  on  Myriotliela,  Metschnikoff  on  Turbellarians,  and 
T.  J.  Parker  on  Hydra.  Limnocodium  exhibits  this  mode  of  digestion 
in  the  most  striking  and  obvious  manner,  the  endodermal  cells  of  the 
stomach  showing  with  a  power  of  800  their  amceboid  character,  and 
showing  further  the  presence  of  such  food-bodies  as  Protococci,  dia- 
toms, and  Euglence  in  various  stages  of  digestion  within  the  proto- 
plasm of  single  cells  and  of  aggregated  groups  of  such  cells. 

At  the  meeting  on  June  17  of  the  Linnean  Society  at  which  Pro- 
fessor Allman's  paper  was  read,  it  was  suggested  that  a  compromise 
should  be  effected  between  the  two  names  proposed,  and  that  the 
*  '  Zeitsclir.  f.  wis?.  Zoologio,'  xxiv.  pi.  ii.  fi.2;s.  12  and  15. 


INVEUTEBRATA,    CRYPTOGAMIA,  MICROSCOPY,    ETC.  657 

Medusa  should  be  called  Lhnnocodium  Sowerbii.  Professor  Luiikestcr 
now  writes  *  that  he  shall  "  henceforth  speak  of  the  Medusa  as 
Limnocodium  Soiverbii,  Allman  and  Lankester." 

Physiology  of  the  Fresh-water  Medusa.t — Mr.  G.  J.  Eomanes 
has  worked  out  the  physiology  of  the  new  form,  and  gives  an  interest- 
ing account  of  the  results  so  far  obtained. 

The  natural  movements  of  the  Medusa  precisely  resemble  those  of 
its  marine  congeners.  More  particularly,  these  movements  resemble 
those  of  the  marine  sj)ecies  which  do  not  swim  continuously,  bat 
indulge  in  frequent  pauses.  In  water  at  the  temperature  of  that  in 
the  Victoria  Lily-house  the  pauses  are  frequent,  and  the  rate  of  the 
rhythm  irregular,  suddenly  quickening  and  slowing  even  during  the 
same  bout,  which  has  the  effect  of.  giving  an  almost  intelligent  appear- 
ance to  the  movements.  This  is  especially  the  case  with  young 
specimens.  In  colder  water  (65''  to  '<  6°)  the  movements  are  more 
regular  and  sustained,  so  that,  guided  by  the  analogy  furnished  by 
experiments  on  the  marine  forms,  he  infers  that  the  temperature  of 
the  natural  habitat  of  this  Medusa  cannot  be  so  high  as  8j°.  In 
water  at  that  temj^erature  the  rate  of  the  rhythm  is  enormously  high, 
sometimes  rising  to  three  pulsations  per  second.  But  by  progressively 
cooling  the  water,  this  rate  may  be  progressively  lowered,  as  in  the 
case  of  the  marine  species ;  and  in  water  at  65°  the  maximum  rate 
observed  was  eighty  pulsations  per  minute.  As  the  temperature  at 
which  the  greatest  activity  is  displayed  by  the  fresh-water  species  is 
fatal  to  all  the  marine  species  which  he  has  observed,  the  effects  of 
cooling  are  only  parallel  in  the  two  cases  when  the  effects  of  a  series 
of  higher  temperatures  in  the  one  case  are  compared  with  those  of  a 
series  of  lower  temperatures  in  the  other.  Similarly,  while  a 
temperature  of  70'^  is  fatal  to  all  the  species  of  marine  Medusfc,  it  is 
only  100°  that  is  fatal  to  the  fresh-water  species.  Lastly,  while  the 
marine  species  will  endure  any  degree  of  cold  without  loss  of  life, 
such  is  not  the  case  with  the  fresh- water  species.  Marine  Mcduste, 
after  having  been  frozen  solid,  will,  when  gradually  thawed  out,  again 
resume  their  swimming  movements ;  but  this  fresh-water  Medusa  is 
completely  destroyed  by  freezing.  Upon  being  thawed  out,  tlio 
animal  is  seen  to  have  shrunk  into  a  tiny  ball,  and  it  never  again 
recovers  either  its  life  or  its  shape. 

The  animals  seek  the  sunlight,  congregating  at  the  unshaded  end 
of  the  tank.  Moreover,  during  the  daytime  they  swim  about  at  the 
surface  ;  but  when  the  sun  goes  down  they  subside,  and  can  no  longer 
be  seen,  in  all  these  habits  resembling  many  of  the  sea-water  species. 
They  are  themselves  non-luminous. 

On  excising  the  margin  of  the  nectocalyx,  the  result  corresponded 
precisely  with  that  which  is  obtained  in  the  case  of  marine  species, 
the  operation  producing  immediate,  total,  and  i»crnianent  paralysis  of 
the  nectocalyx,  while  the  severed  margin  continues  to  pulsate  for  two 
or  three  days. 

A  point  of  S2)ecially  physiological  interest  is  that  in  its  uniinitilatcd 

♦  'Nature,'  x.\ii.  (1880;  p.  I'Jl.  t  I-oc.  i-it..  \:  lltl. 

VOL.  111.  -    X 


658  KECORD    OF    CURRENT    RESEARCHES   RELATING   TO 

state  tlio  frcsli-water  Medusa  exhibits  the  power  of  localizing  with  its 
manubrium  a  seat  of  stimulation  situated  in  the  bell.  When  a  part 
of  the  bell  is  nipped  with  the  forceps,  or  otherwise  irritated,  the 
free  end  of  the  manubrium  is  moved  over  and  applied  to  the  part  irri- 
tated. So  far,  the  movement  is  precisely  similar  to  that  occurring  in 
Tiaropsis  indiccms*  But  there  is  a  curious  difference ;  for  while  in 
T.  indicans  these  movements  of  localization  continue  unimpaired  after 
the  margin  of  the  bell  has  been  removed,  and  will  be  ineffectually 
attempted  even  after  the  bell  is  almost  entirely  cut  away  from 
its  connections  with  the  manubrium,  in  the  fresh-water  Medusa 
the  movements  cease  after  the  extreme  margin  of  the  bell  has  been 
removed.  For  some  reason  or  another  the  integrity  of  the  margin 
here  seems  to  be  necessary  for  exciting  the  manubrium  to  perform  its 
movements  of  localization.  It  is  clear  that  this  reason  must  either  be 
that  the  margin  contains  the  nerve-centi'es  which  preside  over  these 
localizing  movements  of  the  manubrium,  or,  much  more  probably,  that 
it  contains  some  peripheral  nervous  structures  which  are  alone  capable 
of  transmitting  to  the  manubrium  a  stimulus  adequate  to  evoke  the 
movements  of  localization.  In  its  unmutilated  state  this  Medusa  is  at 
intervals  perpetually  applying  the  extremity  of  its  manubrium  to  one 
part  or  another  of  the  margin  of  the  bell,  the  part  of  the  margin 
touched  always  bending  in  to  meet  the  approaching  extremity  of  the 
manubrium.  In  some  cases  it  can  be  seen  that  the  object  of  this  co- 
ordinated movement  is  to  allow  the  extremity  of  the  manubrium — i.  e. 
the  mouth  of  the  animal — to  pick  oif  a  small  j)article  of  food  that  has 
become  entangled  in  the  marginal  tentacles.  It  is  therefore  not  im- 
probable that  in  all  cases  this  is  the  object  of  such  movements, 
although  in  most  cases  the  particle  which  is  caught  by  the  tentacles  is 
too  small  to  be  seen  with  the  naked  eye.  As  it  is  thus  no  doubt  a 
matter  of  great  importance  in  the  economy  of  this  Medusa  that  its 
marginal  tentacles  should  be  very  sensitive  to  contact  with  minute 
particles,  so  that  a  very  slight  stimulus  applied  to  them  should  start 
the  co-ordinated  movements  of  localization,  it  is  not  surprising  that 
the  tentacular  rim  should  present  nerve-endings  so  far  sensitive  that 
only  by  their  excitation  can  the  reflex  mechanism  be  thrown  into 
action.  But  if  such  is  the  explanation  in  this  case,  it  is  curious  that 
in  Tiaropsis  indicans  every  part  of  the  bell  should  be  equally  capable 
of  yielding  a  stimulus  to  a  precisely  similar  reflex  action. 

On  cutting  off  portions  of  the  margin,  and  stimulating  the  bell 
ahove  the  portions  of  the  margin  removed,  the  manubrium  did  not  remain 
passive  as  it  did  when  the  ivhvle  margin  of  the  bell  was  removed ;  but 
it  made  ineffectual  efforts  to  find  the  offending  body,  and  in  doing  so 
always  touched  some  part  of  the  margin  which  was  still  unmutilated. 
This  fact  can  only  be  explained  by  supposing  that  the  stimulus  sup- 
plied to  the  mutilated  part  is  spread  over  the  bell,  and  falsely  referred 
by  the  manubrium  to  some  part  of  the  sensitive — i.  e.  unmutilated — 
margin. 

But  to  complete  this  account  of  the  localizing  movements  it  is 
necessary  to  state  one  additional  fact  which,  for  the  sake  of  clearness, 
*  '  Phil.  Trans.,'  clxvii. 


INVEBTEBRATA,   CRYPTOGAMIAj    MICROSCOPY,   ETC.  659 

has  been  hitherto  omitted.  If  any  one  of  the  four  radial  tubes  is 
irritated,  the  manubrium  will  correctly  localize  the  seat  of  irritation, 
whether  or  not  the  margin  of  the  bell  has  been  previously  removed. 
This  greater  case,  so  to  sjicak,  of  localizing  stimuli  in  the  course  of 
the  radial  tubes  than  anywhere  else  in  the  umbrelhi  except  the  margin, 
corresponds  with  what  is  found  to  be  the  case  in  T.  indicans,  and  pro- 
bably has  a  direct  reference  to  the  distribution  of  the  principal  nerve- 
tracts. 

On  the  whole,  therefore,  contrasting  this  case  of  localization  with 
the  closely  parallel  case  presented  by  T.  indicans,  it  may  be  said  that 
the  two  chiefly  differ  in  the  fresh-water  Medusa,  even  when  un- 
mutilated,  not  being  able  to  localize  so  promptly  or  so  certainly ;  and 
in  the  localization  being  only  performed  with  reference  to  the  margin 
and  radial  tubes,  instead  of  with  reference  to  the  whole  excitable 
surface  of  the  animal. 

All  marine  Medusfe  are  very  intolerant  of  fresh  water,  and  there- 
fore, as  the  fresh- water  species  must  i^resumably  have  had  marine 
ancestors,*  it  seemed  an  interesting  question  to  determine  how  far  this 
species  would  prove  tolerant  of  sea-water.  For  the  sake  of  comparison 
the  effects  of  fresh  water  upon  the  marine  species  are  first  dcscribed.t 
If  a  naked-eyed  Medusa  which  is  swimming  actively  in  sea-water  is 
suddenly  transferred  to  fresh  water,  it  will  instantaneously  collapse, 
become  motionless,  and  sink  to  the  bottom  of  the  vessel,  remaiuinfr 
motionless  until  it  dies ;  but  if  it  be  again  transferred  to  sea-water  it 
will  recover,  provided  that  its  exposure  to  the  fresh  water  has  not 
been  too  long.  It  never  survives  an  exposure  of  fifteen  minutes,  but  may 
survive  an  exposure  of  ten,  and  generally  survives  an  exposure  of  five. 
But  although  tlicy  thus  continue  to  live  for  an  indefinite  time,  their 
vigour  is  conspicuously  and  permanently  imjiaircd.  While  in  the 
fresh  water  irritability  persists  for  a  short  time  after  spontaneity  has 
ceased,  and  the  manubrium  and  tentacles  are  strongly  retracted. 

Turning  now  to  tlic  case  of  the  fresh-water  species,  when  first  it  is 
dropped  into  sea-water  at  85^  there  is  no  change  in  its  movements  for 
about  fifteen  seconds,  although  the  tentacles  may  be  retracted.  But 
then,  or  a  few  seconds  later,  there  generally  occurs  a  scries  of  two  or 
three  tonic  spasms  separated  from  one  another  by  an  interval  of  a  few 
seconds.  During  the  next  half-minuto  the  ordinary  contractions 
become  progressively  weaker,  until  they  fade  away  into  mere  twitching 
convulsions,  wliich  affect  different  parts  of  the  bell  irregularly.  After 
about  a  minute  from  the  time  of  the  first  immersion  all  movement 
ceases,  the  bell  remaining  passive  in  partial  systole.  There  is  now  no 
vestige  of  irritability.  If  transferred  to  fresh  water  after  five  minutes' 
exposure,  tlitro  immediately  supervenes  a  strong  and  persistent  tonic 
spasm,  resembling  rigor  mortifv,  and  tlio  animal  remains  motituiless  for 
about  twenty  minutes.  Slight  twitching  contractions  then  begin  to 
display  themselves,  which,  however,  do  not  affect  the  whole  bell,  but 

*  I-ooking  to  the  oiKprmons  iiuiiilH;r  of  nmrino  eixscios  of  Modus.!?,  it  id  nnicli 
moro  ))ri)l)iililo  tl.at  tin;  frL'.-%li-\viiUr  sjifcica  %verc  dorivod  from  tlnin,  than  thiitthey 
wiro  ill  rived  frmii  a  t'rcHli-wiitrr  niici'.itry. 

t  For  full  iiccouut  Bco  '  I'liil.  Tiftu.--.,'  clxvii.  pp.  711,  71."). 

•J  \  '2 


660  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

occur  partially.  The  tonic  spasm  continues  progressively  to  increase 
in  severity,  and  gives  the  outline  of  the  margin  a  very  irregular  form  ; 
the  twitching  contractions  become  weaker  and  less  frequent,  till  at  last 
they  altogether  die  away.  Irritability,  however,  still  continues  for  a 
time,  a  nip  with  the  forceps  being  followed  by  a  bout  of  rhythmical 
contractions.  Death  occurs  in  several  hours  in  strong  and  irregular 
systole. 

If  the  exposure  to  sea-water  has  only  lasted  two  minutes,  a  similar 
series  of  phenomena  are  presented,  excejit  that  the  spontaneous  twitch- 
ing movements  supervene  in  much  less  time  than  twenty  minutes.  But 
an  exposure  of  even  one  minute  may  determine  a  fatal  result  a  few 
hours  after  the  Medusa  has  been  restored  to  fresh  water. 

Contact  with  sea-water  causes  an  opalescence  and  essential  disin- 
tegration of  the  tissues,  which  precisely  resemble  the  effects  of  fresh 
water  upon  the  marine  Medusai.  When  immersed  in  sea-water  this 
Medusa  floats  iipon  the  surface,  owing  to  its  smaller  specific  gravity. 

In  diluted  sea-water  (50  per  cent.)  the  preliminary  tonic  spasms  do 
not  occur,  but  all  the  other  phases  are  the  same,  though  extended  through 
a  longer  period.  In  sea-water  still  more  diluted  (1  in  4  or  6)  there  is 
a  gradual  loss  of  sjjontaneity,  till  all  movement  ceases,  shortly  after 
which  irritability  also  disappears  ;  manubrium  and  tentacles  expanded. 
After  an  hour's  continued  exposure  intense  rigor  mortis  slowly  and 
progressively  develops  itself,  so  that  at  last  the  bell  has  shrivelled 
almost  to  nothing.  An  exposure  of  a  few  minutes  to  this  _  strength 
places  the  animal  past  recovery  when  restored  to  fresh  water.  In  still 
weaker  mixtures  (1  in  8  or  10)  sjwntaneity  persists  for  a  long  time, 
but  the  animal  gradually  becomes  less  and  less  energetic,  till  at  last  it 
will  only  move  in  a  bout  of  feeble  pulsations  when  irritated.  In  still 
weaker  solutions  (1  in  12  or  15)  spontaneity  continues  for  hours, 
and  in  solutions  of  from  1  in  15  to  18  the  Medusa  will  swim  about 
for  days. 

It  will  be  seen  from  this  account  that  the  fresh-water  Medusa,,  is 
even  more  intolerant  of  sea-water  than  are  the  marine  sjDecies  of 
fresh  water.  Moreover  the  fresh-water  Medusa  is  beyond  all  com- 
parison more  intolerant  of  sea-water  than  are  the  marine  species  of 
brine ;  for  the  marine  species  will  survive  many  hours'  immersion  in 
a  saturated  solution  of  salt.  While  in  such  a  solution  they  are 
motionless,  with  manubrium  and  tentacles  relaxed,  so  resembling  the 
fresh-water  Medusa  shortly  after  being  immersed  in  a  mixture  of 
1  part  sea-water  to  5  of  fresh ;  but  there  is  the  great  difference  that 
while  this  small  amount  of  salt  is  very  quickly  fatal  to  the  fresh-water 
species,  the  large  addition  of  salt  exerts  no  permanently  deleterious 
influence  on  the  marine  species. 

We  have  thus  altogether  a  curious  set  of  cross  relations.  It 
would  appear  that  a  much  less  profound  physiological  change  would 
be  required  to  transmute  a  sea-water  jelly-fish  into  a  jelly-fish  adapted 
to  inhab  t  brine,  than  would  be  required  to  enable  it  to  inhabit  fresh 
water.  Yet  the  latter  is  the  direction  in  which  the  modification  has 
taken  place,  and  taken  place  so  completely  that  sea-water  is  now  more 
poisonous  to  the  modified  species  than  is  fresh  water  to  the  unmodified. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  661 

There  can  be  no  doubt  that  the  modification  was  gradual — probably 
brought  about  by  tlie  ancestors  of  the  fresh-water  Medusa  penetrating 
higher  and  higher  through  the  brackish  waters  of  estuaries  into  the 
fresh  water  of  rivers — and  it  would,  the  author  thinks,  be  hard  to 
point  to  a  more  remarkable  case  of  profound  physiological  modifica- 
tion in  adaptation  to  changed  conditions  of  life.  If  an  animal  so 
exceedingly  intolerant  of  fresh  water  as  is  a  marine  jelly-fish,  may  yet 
have  all  its  tissues  changed  so  as  to  adaj)t  them  to  thrive  in  fresh 
Water,  and  even  die  after  an  exposure  of  one  minute  to  their  ancestral 
element,  assuredly  we  can  see  no  reason  why  any  animal  in  earth  or 
sea  or  anywhere  else  may  not  in  time  become  fitted  to  change  its 
element. 

Porifera. 

Sponges  of  the  Leyden  Museum.* — In  this,  the  first  part  of  his 
communication  (written  in  English),  Mr.  Vosmaer  deals  with  the  family 
of  the  Desmacidinidfe.  As  is  well  known,  these  and  all  the  siliceous 
sponges  are  not  only  difficult  to  determine  on  account  of  their  great 
variability,  but  from  the  technical  objection  that  Bowerbank  and 
Schmidt,  two  leading  authorities,  worked  almost  simultaneously,  and 
altogether  independently  of  one  another.  After  giving  the  palm  to 
Schmidt,  the  author  describes  the  symbols  he  employs  in  his  descrip- 
tions, and  then  passes  to  a  description  and  enumeration  of  the  species  ; 
of  these  he  gives  165,  some  of  which  are  new,  and  these  he  places 
in  sixteen  genei-a,  three  of  which,  Ainphilectns,  Crnmhe,  and  Hastatus, 
are  new ;  the  characters  of  some  of  the  others  are  emended.  The 
paper  seems  from  the  remarks  which  the  author  makes  on  the  varia- 
bility of  species,  to  be  a  distinct  advance  on  most  essays  on  the 
subject  which  have  appeared  in  the  English  language. 

Structure  and  Affinities  of  the  Genus  Protospongia,  Salter.f — 
Mr,  W.  J.  Sollas  describes  the  character  of  the  Cambrian  genus 
Protosjoongia  from  the  original  and  other  specimens.  In  Dr.  Hicks's 
specimen  the  spicules  of  the  sponge  show  their  original  form,  when 
it  is  clear  that  they  are  not  fused  together  into  a  continuous  network  ; 
thoy  form  a  network  only  by  the  interlacing  of  tlicir  extremities. 
The  spicules  arc  quadriradiate,  with  the  centre  raised,  so  that  each 
spicule  indicates  the  outlines  of  a  low  four-sided  pyramid,  the  centre 
being  at  the  apex,  and  the  four  rays  representing  the  four  edges  of  the 
pyramid.  The  rays  do  not  diverge  at  right  angles,  and  thus  the  base 
of  the  pyramid  is  oblong,  though  this  may  be  due  to  distortion.  From 
some  indications  the  author  is  inclined  to  believe  that  a  fifth  ray  may 
have  sprung  from  the  centre  of  the  spicule  downwards.  The  rays  of 
the  spicules  appear  to  be  cylindrical.  The  spicules  are  generally  of 
seveial  sizes,  the  larger  ancs  foiming  a  framework  which  is  filled 
in  by  the  smaller  forms,  tlic  latter  being  regularly  arranged,  so  that 
the  smaller  ones  fill  up  the  S(piare  spaces  left  between  the  rays  of  the 
larger,  and   thus    build  up  a  network  of  square  meshes  gradually 

*  'Notes  R.  Mus.  Nrtherlands '  (ii.  1880)  p.  99. 

t  '  Abstr.  Prc)c.  Geol.  8oc.  Lend.,'  No.  387  (1880)  p.  1. 


662  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

diminisliing  in  size.  The  sponge-wall  seems  to  have  consisted  of 
more  than  one  layer  of  spicules.  The  spicules  were  probably  originally 
siliceous,  but  now  they  consist  of  iron  pyrites. 

With  regard  to  the  systematic  position  of  Protospongia,  the  oldest 
known  sponge,  the  author  remarks  that  similar  spicules  similarly 
arranged  are  to  be  met  with  in  the  Hexactinellidse,  the  absence  of 
one  or  two  rays  being  not  unusual  in  part  of  the  spicules  of  true 
Hexactinellids.  As  the  spicules  are  free,  he  would  refer  the  sponge 
to  Zittel's  Lyssakina,  which  are  nearly  equivalent  to  Carter's  Sarco- 
hexactinellida. 

Protozoa. 

Butschli's  Protozoa. — The  first  part  of  the  second  edition  of  the 
first  volume  of  Bronn's  '  Klassen  u.  Ordnungen  des  Thier-Eeichs,' 
which  contains  the  Protozoa,  has  just  appeared ;  it  is  by  Dr.  O. 
Uiitschli,  of  Heidelberg.  The  part  contains  only  the  commence- 
ment of  the  account  of  the  first  division  (class  or  subphylum)  to 
which  the  name  Sarcodina  is  given ;  the  limits  of  the  class  are  not 
•quite  the  same  as  those  proposed  by  Hertwig  and  Lesser,  for,  as  here 
defined,  it  consists  of  three  subclasses,  Ehizopoda,  Heliozoa,  and 
Eadiolaria.  The  bibliography  of  the  first  of  these  recites  118  titles. 
The  four  plates  contain  nearly  70  figures,  of  which  most  are  taken 
from  the  special  communications  of  various  authors.  It  is  intended 
to  complete  the  subject  in  12-15  parts,  with  30  plates. 

Amcebiform  and  other  new  Foraminifera.* — Mr.  H.  J.  Carter 
describes  some  specimens  dredged  up  from  the  Gulf  of  Manaar,  between 
Ceylon  and  the  southern  extremity  of  India. 

Under  the  head  of  Testamcebiformia — new  group — (Char.,  amcebi- 
form, testaceous)  Mr.  Carter  says  that  hitherto  almost  exclusive  atten- 
tion has  been  given  to  the  free  Foraminifera,  whose  exquisitely  varied 
forms,  although  in  many  instances  microscopic,  have  not  unnaturally 
proved  as  attractive  as  the  frustules  of  the  Diatomacete,  so  that  it 
has  become  an  object  of  great  search  to  find  out  a  new  form, 
although  it  can  hardly  be  seen  by  the  unassisted  eye.  This  to  the 
specialist  is  a  matter  of  paramount  importance,  but  to  the  biologist 
one  of  insignificance  compared  with  the  less  attractive  and  larger 
forms,  which  tend  to  reveal  the  life-history  and  connections  of  the 
class  generally. 

For  some  time  past  he  has  anticipated  the  existence  of  amcebiform 
Foraminifera,  dififerentiated  only  by  the  peculiarity  of  their  respective 
pseudopodial  expansions ;  but  of  course  this  cannot  be  ascertained 
except  by  minute  and  laborious  examination  of  the  living  so-called 
Bathyhius,  which  probably  abounds  with  them  after  the  manner  of 
fresh-water  Ehizopods,  forming  a  similar  slime  to  that  which  may 
often  be  observed  over  the  bottom  of  stagnant  (i.  e.  still)  fresh-water 
pools.  He  was  not,  however,  prepared  to  find  that  some  of  these 
ever-changing  forms  were  stereotyped  as  it  were  by  the  permanent 
secretion  of  a  calcareous  test,  until  the  specimens  from  the  Gulf  of 
Manaar  came  under  his  notice,  when  he  observed  two  well-characterized 

*  '  Ann.  and  Mag.  Nat.  Hist.,'  v.  (1880)  p.  437. 


INVERTEBRATA,   CRYPTOGAMIA,    MICROSCOPY,   ETC.  663 

forms  to  be  very  abundant  in  them,  which  he  describes  under  the 
generic  names  of  Holocladina  and  Cysteodictyina  respectively. 

With  regard  to  Holocladina  (pushdifera)  it  is  evident  from  the 
form  of  the  test  that  the  living  animal  possessed  an  amceboid  form  ; 
but  whether  both  were  developed  successively  (that  is,  one  part  after 
another  like  the  crust  on  a  stream  of  lava),  or  the  living  animal  was 
fully  developed  before  the  test  was  secreted,  there  is  no  evidence  now 
to  show,  beyond  the  presumption  that  the  former  was  most  likely  the 
case.  The  absence  of  all  foreign  material  in  the  interior,  together 
with  its  form,  distinctly  separates  it  from  the  genera  Carpenteria 
and  Polytrema,  while  it  chiefly  differs  from  Aphrosina  *  in  not  being 
multilocular.  No  oral  apertures  were  satisfactorily  seen  ;  but  it  may 
fairly  be  inferred  that  each  of  the  conical  projections  on  the  terminal 
branchlets  bears  one,  through  which  a  pseudopodium  issues  during 
the  living  state,  in  search  of  that  subtile  kind  of  nourishment  which 
the  present  emptiness  of  the  test  indicates  to  have  been  the  nature  of 
the  aliment. 

Amongst  the  other  forms  described  is  CeratesUna,  n.  gen.  (2  n.  sp.), 
in  which  the  test  is  horny,  of  a  dark  amber  colour,  and  translucent. 
The  composition  of  the  test  here  brings  us  one  degree  nearer  than 
that  of  the  Testamcebiformia  to  the  absolutely  naked  Foraminifer,  to 
whose  conjectured  existence  the  author  before  alluded;  but  lest  it 
might  be  thought  that  it  is  merely  the  chitine  without  the  calcareous 
material  which  characterizes  this  genus,  it  should  be  mentioned  that 
if  a  specimen  of  Ceratestina  and  an  ordinary  calcareous  test  of  a 
Foraminifer  together  be  exposed  to  the  influence  of  an  acid  solution 
(e.  g.  dilute  nitric  acid),  the  latter  will  be  dissolved  and  leave 
scarcely  any  residue,  while  the  former  remains  unaffected,  proving 
that  the  horny  substance  of  the  Ceratestina  is  something  more  than 
the  chitine  which  may  support  the  calcareous  material ;  indeed  the 
best  way  of  extracting  a  Ceratestina  is  to  put  the  calcareous  substance 
containing  the  specimen  into  a  strong  solution  of  nitric  acid,  which, 
all  know,  is  instant  destruction  to  a  calcareous  test.  In  some  cases 
the  test  is  composed  in  one  part  of  the  ordinary  calcareous  material, 
and  in  the  other  of  the  horny  substance  only,  which  condition  is  so 
usually  seen  in  one  species  tliat  it  would  appear  to  be  rather  natural 
than  accidental.  The  author  alludes  to  a  species  which  he  figured  and 
described,  conjecturally,  as  tlic  "embryonic  form"  of  Carpenteria  mon- 
ticnlaris,-\  but  which  now,  finding  it  to  be  a  distinct  species,  he  would 
name  Carpenteria  microscopica.  The  chambers  of  Carpenteria  utricu- 
laris  and  also  the  cells  of  Polytrema  mimtceum  are  often  lined  by  a 
stifi'  horny  layer  of  considerable  thickness  ;  but  under  what  circum- 
stances, he  is  ignorant,  as  it  does  not  occur  always  :  this,  however,  is 
secondary  and  must  not  be  confounded  with  Ceraiestina,  in  wliich  tho 
liorny  structure  is  primary  and  i)ormanent. 

The  author  also  describes  as  new  species  Polytrema  n/lindriritm 
and  P.  meKentcricnm ;  and  as  new  species  or  varieties,  Calcariiia  adrar 
var.  hixj^ida  and  Alreolina  sinitosa. 

*  Sco  this  Jouriinl,  ii.  (IS70)  p.  r.OO. 

t  'Aim.  nnd  Mng.  Nat.  HJHt.,'  .\ix.  (1S77)  p.  'Ji:{. 


664  RECORD    OF    CURRENT    RESEARCHES   RELATINQ    TO 

Vampyrella  lateritia,*— A  winter  in  the  'American  Journal  of 
Microscopy '  details  some  observations  which  he  made  on  this 
Rhizopod.  The  animal  is  in  colour  reddish-yellow,  in  general 
appearance  much  like  the  common  sun-animalcule,  Actinoplirys  sol, 
but  larger,  more  active  in  its  movements,  and  with  the  power  to  change 
its  form  with  greater  facility.  Dr.  Leidy's  description  of  it  is :  — 
"Animal  usually  ^c/mop/irv/s-like,  with  a  soft  spheroidal  body,  capable 
of  amoeboid  variations  of  form,  composed  of  pale,  colourless,  granular 
jn'otoplasm,  with  abundance  of  colouring  matter,  oil-like  molecules, 
and  vacuoles.  Pseudopods  as  Actino])ln-ys-\\\e  rays,  Acineta-\\ke 
rays,  and  digit-like,  lobate,  or  wave-like  expansions." 

Amongst  other  details  the  author  says  that  he  saw  one  individual  make 
its  way  rapidly  across  the  field  of  view,  and  seeming  as  though  some 
innate  knowledge,  some  rational  impulse,  were  guiding  it,  for  without 
hesitation  the  little  mass  of  living  jelly  passed  directly  to  a  filament 
of  Spirogyra  longata  to  which  it  became  attached,  withdrawing  a 
portion  ot  its  rays  for  the  purpose,  and  conforming  itself  to  the  shape 
of  the  plant  surface.  There  it  had  the  apj)earance  of  resting,  stoj^ping 
the  flow  of  protoplasmic  droj)s  along  the  rays  jixst  where  each  one 
haiipened  to  be.  This  was  at  nine  o'clock.  One  minute  later,  the 
first  turn  of  the  chlorophyll  band  within  the  cell  suddenly  fell  down. 
In  another  minute  the  second  turn  followed ;  in  three  minutes,  the 
entire  cell-contents  were  loose  and  slowly  gliding  toward  the  Vam- 
pyrella which  was  sucking  them  in.  At  five  minutes  past  nine  the 
cell  was  empty,  and  the  animal  moving  to  the  next.  Here  the  same 
operation  was  repeated.  In  its  third  excursion  it  placed  itself  across 
tlie  partition  between  two  cells,  and  preceded  to  imbibe  the  contents 
«f  both  at  once.  From  one  the  chlorophyll  bands  were  loosened  and 
dragged  out  in  a  long  strip,  while  in  the  other  they  were  broken  down 
into  a  homogenous  green  mass  and  quietly  sipped  out,  the  Vampyrella 
visibly  swelling.  It  was  not  until  seven  cells  were  emptied  that  its 
appetite  was  satisfied.  A  repetition  of  this  was  seen  in  the  case  of 
another  individual.  The  creature  must,  the  author  thinks,  have  the 
power  to  secrete  a  fluid  capable  of  dissolving  the  cellulose,  and  of 
acting  upon  the  chlorophyll  and  protoplasm  within  the  Alga,  besides 
its  very  evident  ability  to  remove  the  latter  without  first  dragging 
tliem  out,  or  surrounding  them  Amoeba  fashion.  When  the  seventh 
cell  had  been  cleaned  out  the  Vampyrella  transferred  itself  to  a  fila- 
ment of  another  species  of  the  same  genus,  where  it  again  rested,  but 
did  not  feed,  with  two  short  blunt  pseudopods  protruding  as  if 
clinging  to  the  plant. 

Two  days  later  the  field  contained  a  cyst  presenting  three  very 
distinct  lines  dividing  it  into  as  many  parts.  Almost  as  soon  as  seen, 
the  VampyrellcB  began  to  escape,  two  making  their  exit  at  opposite 
sides  simultaneously,  the  third  which  the  sac  contained  following 
through  one  of  the  apertures  already  made.  The  process  was  a  rapid 
one.  A  thick  colourless  pseudopod  appeared  first.  Hardly  did  it 
touch  the  wall  before  the  opening  was  made.  The  ray-like  pseudopods 
were  protruded  before  one-third  of  the  animal  had  escaped.  Many 
*  'Am.  Joiirn.  Micr.,'  v.  (ISSO)  j).  105. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  6G5 

of  the  dark  spots  upon  tbe  cyst  walls,  probably  of  excrementitious 
matter,  followed  as  free  granules,  others  remaining  behind. 

Acinetse.* — In  continuation  of  his  previous  note,f  Mr.  W.  G. 
Cocks  states  that  he  is  satisfied  the  perfect  forms  of  Acinetce  which 
he  observed  in  large  numbers  on  the  filaments  of  an  Alga,  were  in 
fact  developed  from  some  rudimentary,  gelatinous-looking  masses 
throwing  out  fine  radiations  or  pseudopodia  (or  more  properly,  per- 
haps, the  Amoeboid  forms  of  Acinetce),  found  by  Mr.  Badcock  in  the 
autumn — the  masses  having  disappeared,  and  the  swarms  of  perfect 
Acinetce  taking  their  place  on  the  one  identical  Alga  only.  The 
development  was  not,  however,  actually  observed. 

Mr.  Cocks  also  traced  the  development  of  an  Acineta  from  the 
ciliated  "  swarm-germ "  emitted  by  an  adult  specimen,  through  the 
short  pedicellate  form,  and  that  which  has  been  described  as  Podophrya 
fixa,  back  to  the  perfect  Acineta.  He  also  satisfied  himself  that  these 
organisms  arc  not  steps  in  the  life-history  of  any  of  the  species  of 
Vorticelkt,  E^iHtylis,  &c.,  but  arc  distinct  organisms. 


BOTANY. 

A.  GENERAL,  including  Embryology  and  Histology 
of  the  Phanerogamia. 

Disengagement  of  Carbonic  Acid  from  Roots.| — M.  Cauvet,  of 
Lyons,  has  made  a  fresh  series  of  experiments  on  this  subject.  The 
general  conclusions  arrived  at  are  that  carbonic  acid  is  disengaged  in 
smaller  quantity  during  tlie  night  than  during  any  part  of  the  day  ; 
that  it  augments  during  the  morning  and  diminishes  towards  evening; 
tlie  amount  disengaged  dtiring  the  night  being  not  more  than  one- 
fourtli  of  that  emitted  during  the  three  periods  of  the  day.  This 
diflbrence  he  believes  to  be  mainly  due  to  the  action  of  light,  which 
greatly  promotes  respiration;  all  the  functions  of  the  plant,  especially 
transjiiration  and  respiration,  being  much  less  active  by  night  than  by 
day. 

Sensitiveness  in  the  Acacia.§ — In  Sejitember  last  Dr.  T.  L. 
Phijjsun  maile  some  experiments  on  the  development  of  sensibility  in 
tlie  common  Acacia,  Itobinia  pseuclacacia.  The  subject  was  a  fine 
tree,  five  or  six  years  old,  with  luxuriant  foliage. 

The  first  experiment  was  made  at  5.30  on  the  evening  of 
September  17th,  the  wind  being  S.S.E.,  the  temperature  17^  C,  and 
tlic  sun  clear,  Tlie  leaves  wore  sent  to  sleep,  whilst  still  brilliantly 
lighted  l)y  the  sun,  by  submitting  the  terminal  leaflet  to  a  scries  of 
ta2)s  with  the  finger.  After  ffom  ten  to  twenty  smart  tajis  the  other 
leaflets  commenced  to  close,  and  at  the  end  oi'  jive  minutes  were  all 
"  nsleej)."  The  lateral  leaflets  folded  up  one  after  another,  commencing 
witli  that  nearest  to  tlic  point  of  the  leaf,  i.  e.  tlie  part  struck. 

*  'Sci.-Cinssip'  ri880).  p.  1.").5.  t  An/r,  p.  470. 

X  'Hull.  Soc-.  ]M.  Franco,'  xxvii.  (1880)  p.  4:5. 
«J  •Coinj.tcH  l.'.iidiis,'  xo.  (I8H0)  |..  122H. 


666  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

The  following  day  at  12 .  30  this  experiment  was  repeated  with  a 
like  result,  the  leaves,  the  terminal  leaflet  of  which  was  struck,  going 
to  sleep  in  the  space  of  four  and  a  half  minutes.  It  took,  however, 
tioo  to  three  hours'  sunlight  to  restore  the  lateral  leaflets  to  their  former 
horizontal  position. 

This  falling  down  one  after  the  other  of  the  leaflets,  com- 
mencing from  the  extremity  of  the  leaf,  is  exactly  similar  to  what  is 
observed  in  the  sensitive  plant,  in  which,  as  the  author  showed  in 
1876,*  there  is  simply  the  development  in  the  highest  degree  of  a 
phenomenon  which  is  traceable  throughout  the  whole  vegetable 
kingdom. 

The  application  of  a  strong  heat  to  the  terminal  leaflet,  which  acts 
immediately  on  the  sensitive  plant,  produced  no  eifect  on  the  lateral 
leaflets  of  the  Acacia,  even  when  the  terminal  leaflet  was  crisped  and 
burnt  by  a  small  flame.  This  seems  to  the  author  to  demonstrate 
that  the  sap  is  much  less  mobile  in  the  tissue  of  the  one  plant  than 
in  that  of  the  other. 

Copper  in  Plants.f — In  a  recent  memoir,|  M.  Dieulafait  showed 
that  copper  exists  in  a  state  of  complete  diffusion  in  all  the  rocks 
of  the  primordial  formation,  and  in  those  resulting  directly  from 
their  destruction.  Among  other  consequences  of  this,  all  plants 
which  grow  on  such  rocks  should  contain  copper  in  sensible  pro- 
portion. 

M.  Dieulafait  has  tested  this  view,  and  the  following  are  the 
results  of  his  investigations: — 

Copper  exists  in  all  plants  which  grow  on  rocks  of  the. prim  or  dial 
formation.  Its  proportion  is  sufficient  for  it  to  be  recognized  v/ith 
certainty,  even  with  the  ammonia-reaction,  by  using  only  1  gramme 
of  ash. 

Each  of  the  one  hundred  and  twenty-eight  specimens  of  white 
oak  of  marly  strata  showed  the  presence  of  copper  with  1  gramme  of 
ash,  though,  in  general,  the  proportion  of  the  metal  was  less  than  that 
in  plants  of  primordial  strata. 

All  the  specimens  obtained  in  dolomitic  horizons  furnished 
copper  distinctly  recognizable  in  1  gramme  of  ash ;  but  there  were 
great  variations  according  to  the  specimens. 

The  plants  which  live  on  comparatively  pure  limestones  did  not 
furnish  any  traces  of  copper  under  the  conditions  of  the  three  fore- 
going groups.  To  be  able  to  recognize  it  with  certainty,  it  was 
necessary  sometimes  to  use  as  much  as  100  grammes  of  ash. 

Does  copper  exist  normally  in  organs  of  animals  and  in  those  of 
man  ?  The  facts  brought  out  in  the  present  and  previous  memoir 
naturally  led  up  to  this  question,  which  is  shown  to  be  less  simple 
and  absolute  than  has  been  believed  hitherto.  M.  Dieulafait  hopes 
shortly  to  communicate  facts  as  to  animals  and  man  living  on  the 
primordial  formation. 

*  '  Familiar  Letters  on  some  Mysteries  of  Nature,'  &e.,  p.  139. 

t  '  Comptes  Rendus,'  xc.  (1880)  p.  703. 

J  '  Annales  de  Chimie  et  de  Physique,'  5th  ser.,  xviii. 


INVEETEBKATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  667 

Action  of  Ozone  on  the  Colouring-matters  of  Plants.* — In  some 
experiments  by  Mr.  A.  R.  Leeds,  in  which  many  varieties  of  flowers 
were  exjiosed  during  nineteen  hours  to  the  action  of  a  current  of  152 
litres  of  air,  containing  in  all  228  mgr.  of  ozone,  the  bleaching 
efiected  was  extremely  imperfect.  When  1200  litres  of  air  were 
passed  over  various  flowers  (total  ozone,  1  •  8  grains),  they  were 
partly  or  wholly  bleached  at  the  end  of  five  days.  A  piece  of  calico 
with  a  pattern  in  bright  green  and  black  was  completely  bleached 
during  the  same  interval,  the  green  having  disappeared  completely, 
and  the  stain  of  the  mordant  only  remaining  where  the  black  had  been. 

From  these  and  other  results  it  is  concluded  that  the  colouring- 
matters  of  both  leaves  and  flowers  of  the  species  {Lantana,  Fuchsia, 
Petunia,  Rosa,  Verbena,  Pelargonium,  Bouvardia,  Euphorbia,  &c.)  experi- 
mented with  were  partly  or  wholly  destroyed  by  ozone ;  but  a  con- 
siderable percentage  of  ozone  is  required  to  produce  tliis  result,  or  if 
such  small  amounts  as  are  obtained  in  the  customary  methods  of 
ozonizing  air  by  phosphorus  are  employed  (1  to  3  mgr.  per  litre) 
a  large  volume  of  ozonized  air  must  be  used,  and  a  considerable 
interval  elapse  before  bleaching  is  eifected. 

Red  Colouring-matter  of  the  Leaves  of  the  Virginian  Creeper.t 
The  red  autumn  leaves  of  the  Virginian  creeper  give  up  to  alcohol  a 
beautiful  rose-red  pigment,  which  is  coloured  green  by  a  weak  solu- 
tion of  potash,  the  red  colour  being  again  restored  by  very  dilute 
sulphuric  acid.  Berzelius  has  ali'eady  shown  that  the  green  pigment 
is  different  from  that  of  chlorophyll-grains,  which  is  strikingly 
proved,  according  to  Schnetzler,  by  the  following  experiment : — 

1  volume  of  water,  1  volume  of  the  red  alcoholic  solution,  and 
^  volume  of  sulphuric  acid  are  slightly  agitated  together.  After  a 
short  time  a  beautiful  green  solution  in  ether  with  red  fluorescence 
floats  on  the  top  of  the  solution  of  the  true  chlorophyll-pigment. 
The  red  pigment  of  the  leaves  of  the  Virginian  creeper,  separated, 
from  the  colouring-matter  of  the  chlorophyll,  is  dissolved  in  the 
mixture  of  alcohol  and  water.  It  is  changed  to  green  by  a  solution 
of  potash,  but  is  not  then  fluorescent. 

Chemical  Composition  of  Aleurone-grains.J — Dr.  Vines  con- 
tinues the  account  of  this  investigation,  which  appeared  in  1878. §  It 
was  therein  shown  tliat  the  aleurone-grains  of  the  lupin  consist  of 
three  proteid  substances,  namely,  of  two  globulins — the  one  belonging 
to  the  myosin  group,  the  other  to  tlie  vitellin  group — and  of  a  substance, 
allied  to  the  peptones,  provisionally  tenncd  hcinialbumosc.  In  the 
present  communication  the  results  of  the  investigation  of  the  grains 
of  the  peony  and  of  the  castor-oil  plant  ( liirlnus)  are  given.  The 
grains  of  the  peony  are  found  to  bo  readily  soluble  in  distilled  water. 
Treatment  with  10  per  cent.  NaCl  solution,  however,  proves  tlio 
existence  of  a  myosin-globulin.     Apparently  no  vitcllin-globulin  is 

♦  '  Clum.  News,'  xl.  (1870)  p.  8G.  Sec  '  Jotini.  Cluni.  Soc.,'  Abstr.,  xxxviii. 
(18S0)  p.  5S. 

t  '  Bot  Centrnlbl.,'  i.  (1880)  p.  247. 

i  '  Nature,"  xxii.  (1880)  p.  91.         §  '  Proc.  Roy.  6oc.,'  xxviii.  (187.>^)  p.  218. 


C(J8  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

present.  The  grains  contain  hemialbumose  in  considerable  quantity. 
The  grains  of  Ricinus  present  a  complex  structure.  They  consist  of  a 
mass  of  grouud-substauce  of  proteid  nature,  enclosing  a  crystalloid  of 
proteid  substance  and  a  globoid  which  consists  of  inorganic  matter. 
The  groxmd-substance  is  found  to  be  composed,  like  the  grain  of  the 
lupin,  of  the  two  globulins  and  of  hemialbumose.  The  chemical 
nature  of  the  crystalloid  is  not  so  clearly  made  out.  It  is  slowly 
soluble  in  10  per  cent.  NaCl  solution,  and  readily  soluble  in  20  per 
cent.,  or  in  saturated  NaCl  solution  after  treatment  with  alcohol. 
The  crystalloids  of  several  plants  were  investigated  with  the  view  of 
ascertaining  their  relative  solubility  in  solutions  of  this  salt.  Those 
of  Viola  elatior  and  of  Limim  usitatisshnum  were  found  to  resemble 
those  of  Bicinus  in  this  respect ;  those  of  BefthoUetia  and  of  Cacurhita 
are  readily  soluble  in  10  per  cent,  and  saturated  NaGl  solutions  ; 
those  of  Mtisa  ensete  and  HilUi,  and  those  of  Sparganium  ramosum  are 
either  insoluble  or  only  partially  soluble  in  these  solutions. 

The  points  of  more  general  interest  are  the  action  of  alcohol  in 
promoting  the  solution  of  the  crystalloids  of  Bicinus  in  20  per  cent, 
and  in  saturated  solutions  of  NaCl,  and  the  fact  that  long-continued 
exposure  to  alcohol  does  not  render  the  vegetable  globulins  insoluble 
in  these  solutions. 

The  author  finally  expresses  his  opinion  that  the  caseins  which 
Eitthausen  has  extracted  from  various  seeds  consist  to  a  considerable 
extent  of  precij)itated  hemialbumose. 

"  Cistoma."  * — Under  this  term  Gasparrini  formerly  described  a 
membranous  sac  which  he  claimed  to  have  observed  beneath  the 
semihmar  guard-cells  of  the  stoma,  continuous  with  the  cuticle  of 
the  epidermis  and  of  the  guard-cells.  Other  botanists  not  having 
confii-med  this  observation,  A.  Mori  has  endeavoured  to  set  the  ques- 
tion at  rest  by  a  very  careful  examination,  chiefly  made  on  the 
stomata  of  Cereus  peruiianus,  Ficus  elastica.  Yucca  aloeifolia,  Aloe 
vulgaris,  Euphorbia  officinarum,  Anthurium  Scherzerianum,  Agave  ame- 
ricana,  and  other  plants.  His  observations  tend  to  the  conclusion 
that  the  description  of  the  "  cistoma  "  is  founded  on  a  mistake.  He 
finds  the  cells  at  the  bottom  of  the  stomatic  cavity  destitute  of 
any  cuticular  lining,  the  walls  of  these  cells  consisting  entirely  of 
cellulose,  and  being  in  immediate  contact  with  the  air  which  pene- 
trates the  stomatic  cavity.  The  cuticle  which  is  continuous  with  the 
superficies  of  the  epidermis  invests  the  stomatic  cavity  only. 

Apical  Growth  with  several  Apical  Cells.! — Various  authors 
have  ascribed  a  number  of  apical  cells  to  the  roots  of  Marattiaceae 
and  Ophioglossacese,  the  apices  of  the  stems  of  Selaginella,  and  the 
branches  of  Fucaccfe. 

According  to  the  accurate  definition  of  the  apical  cell  given  by 
Schwendener,  only  a  single  or  several  equivalent  cells  can  be  so 
regarded  which  are  grouped  immediately  around  the  centre  of  the 
apical  point,  and  which  maintain  this  position  dm-ing  the  apical 
growth.      But  some  of  the  daughter-cells   which   result   from   the 

*  '  Nuov.  Giorn.  Bot.  Ital.,'  xii.  (1880)  p.  148. 
t  '  SB.  Ges.  iiaturf.  Frciinrl.  Berlin,'  1879. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  669 

division  of  apical  cells  lose  this  position,  and  are  not  correctly 
regarded  as  apical  cells,  even  if  still  situated  near  the  centre.  The 
number  of  ajiical  cells  may  indeed  be  more  than  one,  but  as  can 
be  proved  on  mechauico-gcomctrical  grounds,  not  so  large  as  Kussow 
claims  for  the  roots  of  Marattiacea).  This  writer  states  that  he 
has,  on  a  longitudinal  section,  observed  as  many  as  from  seven  to  ten 
apical  cells ;  Schweudener  never  foimd  more  than  two  in  Marattia, 
lying  right  and  left  of  the  median  line.  The  complementtxry  trans- 
verse section  shows  altogether  four  apical  cells.  Eussow  appears  not 
to  have  observed  the  true  apex  of  the  root,  but  a  section  of  the  root- 
cap.  The  four  apical  cells  do  not  touch  at  one  point,  but  two  of 
them  form  an  edge. 

Foliage  shoots  of  Juniperus  communis,  seedlings  of  Pinus  inops, 
P.  Laricio,  P.  sijliestris,  and  Abies  alba,  also  show  four  apical  cells, 
two  opposite  ones  forming  again  an  edge. 

B.    CRYPTOGAMIA. 

Cryptogamia  Vascularia. 

Structure  of  the  Fructification  of  Pilularia.* — According  to 
recent  researches  of  Jm-anyi,  the  fructification  of  Pilularia  globulifera 
is  a  leaf-segment  of  peculiar  form.  At  the  time  of  its  formation,  in 
addition  to  the  simple  sterile  foliage-leaves,  other  bifid  leaves  are 
formed,  the  anterior  segment  of  each  of  which  becomes  a  sporangium, 
the  posterior  segment  developing  in  the  ordinary  manner  of  foliage- 
leaves,  appearing  at  an  earlier  stage  as  a  lateral  lobe  of  the  fertile 
segment.  The  chief  ground  for  this  opinion  is  that  the  tissue  of  the 
pedicel  of  the  fructification  always  passes  over  at  once  into  that  of  the 
leaf  situated  behind  it. 

The  first  ai>ix;arancc  of  the  entire  yovmg  fructification  is  that  of 
small  cylindrical  masses  of  tissue,  which  subsequently  assume  au 
obtuse  fusiform  shape,  the  thin-wallcd  cells  being  filled  with  strongly 
refractive  protoplasm.  In  the  centre  of  this  tissue  the  procumbial 
bundle  can  soon  be  detected,  out  of  which  the  vascular  buudle  oi  the 
fructification  is  developed.  At  first  tliis  mass  of  tissue  grows  in 
leugth  nearly  uniformly ;  but  subsequently  the  lower  side  grows 
more  rajjidly,  in  conseciuencc  of  which  tlie  apex  of  the  structure  is 
elevated,  and  appears  concave  on  the  side  wliich  faces  the  sterile  leaf. 
With  this  curvature  it  assumes  a  club-like  form,  and  forms  the 
pedicel  of  the  now  developing  sporocai'p.  On  this  are  formed  subse- 
quently four  sickle-shajjcd  leaf-segments,  from  which  the  principal 
part  of  the  fructification  is  developed,  and  which  form  its  valves. 
They  arc  placed  in  opposite  pairs,  in  such  a  way  that  their  concave 
side  faces  the  centre,  the  convex  side  lying  on  the  outside.  At  an  early 
period  the  apices  of  the  separate  leaf-segments  can  be  distinguished, 
and  soon  afterwards  the  cavities  (lacuna)  sorales)  in  which  the 
sporangia  are  formed.  The  margins  of  the  two  growing  loaves  finally 
coalesce,  while  their  free  apices  still  continue  their  growth.  After  the 
coalescence  of  tbe  segments  the  young  fructification  is  pear-shaped. 

♦  'SIJ.  UiiRar.  Aka.i.  d.  W'iau.,'  18711,  No.  :>.  i>.  Ill  (Hiiiigiiriun).  Set- '  |{..(. 
CVutiall)!.,'  i.  (18S0)  p.  207. 


670  RECORD    OF    CURRENT   RESEARCHES   RELATING   TO 

The  line  of  coalescence  of  tlie  inner  margins  of  the  leaf-segments 
coincides  with  the  central  axis  of  the  mature  fruit.  The  four  crossed 
rows  of  cells  which  are  visible  on  transverse  section,  and  the  signifi- 
cation of  which  has  hitherto  been  obscui-e,  are,  according  to  this  view, 
simply  indications  of  the  coalescence  of  the  adjacent  leaves.  By  the 
thickening  of  the  walls  of  the  superficial  cells  of  the  fructification, 
which  finally  becomes  nearly  globular,  the  soral  cavities  having 
closed  up,  the  lines  of  contact  of  the  leaf-segments  become  at  length 
completely  obliterated. 

Muscinese. 

British  Moss-Flora. — Dr.  E.  Braithwaite,  of  well-known  bryo- 
logical  reputation,  has  commenced  the  publication  of  monographs  of 
the  families  of  British  mosses,  each  complete  in  itself  and  illustrated 
by  plates  of  all  the  species,  with  microscopical  details  of  their 
structure.  Part  I.  includes  the  Andreaeacese,  and  Part  II.  the 
Buxbaumiacese  and  Georgiacese,  each  with  two  plates,  drawn  by  the 
author. 

The  cell-structure  of  the  leaves,  so  important  in  the  distinction  of 
genera  and  species,  receives  due  attention  both  in  the  figures  and 
descriptions.  The  records  of  localities  for  all  but  the  common  species 
are  intended  to  be  numerous,  and  the  bibliography  ampler  than  any 
that  has  hitherto  appeared  in  a  British  work. 

The  arrangement  of  the  families  and  genera  is  principally  in 
accordance  with  that  suggested  by  Professor  Lindberg,*  the  most 
natural  that  has  yet  appeared.  In  this  the  Cleistocarpous  mosses  are 
regarded  as  imperfectly  developed  forms  of  various  Stegocarpous 
families,  with  which  they  agree  in  everything  but  a  separable  operculum, 
and  the  genera  are  framed  on  a  broader  and  more  rational  basis,  just 
as  our  best  botanists  now  deal  with  Phasnogamous  plants.  Professor 
Lindberg's  terms  for  the  position  of  the  reproductive  organs  are  also 
adopted. 

Bryologists  well  know  how  much  a  work  of  this  kind  is  re- 
quired, Wilson's  '  Bryologia  Britannica'  being  unobtainable  except  at 
a  largely  enhanced  price,  and  being  now  altogether  insufficient  as  a 
guide  to  our  recently  much-extended  Moss-Flora. 

Characese. 

British  Characeae'.f — Messrs.  H.  and  J.  Groves  have  compiled  a 
much-needed  monograph  of  the  British  species  of  Characese,  accom- 
panied by  four  good  plates.  The  total  number  of  species  (besides 
two  doubtful  ones)  is  nineteen,  all  previously  described.  The  order 
is  first  divided,  as  is  usually  done,  into  the  two  sections  Chareaj  and 
Nitelleae  (called  by  Groves  Charse  and  Nitellse — objectionable  terms, 
as  being  simply  the  plurals  of  the  generic  name),  each  including 
two  genera,  Chara  and  Lychnothamnus,  Tolypella  and  Nitella.  Of 
Chara  nine  British  species  are  described,  divided  into  three  series, 

*  '  Utcast  till  en  naturlig  Gruppering  af  Eiuropas  Bladmossor  med  toppsittande 
Frukt,'  1878. 

t  '  Trimcu's  Journ.  Bot.,'  ix.  (1880)  p.  97. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  671 

Triplostich^,  Diplostichfc,  and  Haplostichae,  characterized  by  the 
stem  having  respectively  three  times,  twice,  and  the  same  number  of 
cortical  cells  as  branchlets  in  the  whorls.  Lychnothammia  includes 
only  one,  Tohjpella  numbers  three,  and  Nitella  six  British  species. 

Fungi. 

Formation  of  Fat  in  Fungi.* — The  fat  formed  in  vegetable  cells 
is  known  to  be  of  the  nature  of  a  secretion,  and  not  a  product  of  fer- 
mentation ;  it  is  found  in  quantity  varying  with  the  activity  of  the 
growth  and  of  the  oxygen-respiration  (?  assimilation)  of  the  plant.  It 
may  probably  originate  from  the  splittiug-up  of  proteids  in  the  cells 
of  Penicillium  and  other  fungi.  The  relation  of  the  formation  of  fat 
to  the  nutrition  of  the  i^Iant  remains  still  altogether  obscure. 

A  recent  scries  of  experiments  by  Nageli  and  Loew  on  Penicillium 
has  been  directed  chiefly  to  investigate  the  degree  in  which  various 
nutrient  substances  affect  the  formation  of  fat.  These  they  arrange 
in  this  respect  in  the  following  series,  advancing  from  those  less  to 
those  more  favourable : — (1)  ammonium  acetate ;  (2)  ammonium  tar- 
trate and  succinate,  and  asparagine ;  (3)  leucine ;  (4)  peptone ;  (5) 
ammonium  tartrate  plus  sugar ;  (6)  leucine  plus  sugar ;  (7)  peptone 
plus  sugar. 

Secretion  from  a  Fungus-j — M.  Eug.  Fournier  has  observed  on  a 
species  of  Polyporus  ("i^robably  P.  cuticularis)  growing  on  a  plum-stem 
in  his  garden  at  Auteuil,  an  acid  viscid  secretion,  which  begins  to  be 
exuded  daily  as  soon  as  the  pileus  is  exposed  to  the  full  rays  of  the 
sun,  about  9  a.m.,  and  continues  through  the  day  until  and  beyond 
sunset.  In  100  parts  of  the  fluid  were  found  to  be  contained,  on 
chemical  analysis,  0-545  parts  of  organic  matter,  and  0 '065  parts 
mineral  matter,  in  all  1-21  parts  of  residue.  Of  albuminoid  sub- 
stances coagulated  by  heat  there  were  0  •  03  parts,  and  of  glucose  0  •  32 
parts.  The  residue  on  calcination  was  strongly  alkaline,  and  eflervesccd 
with  acids.  It  consisted  of  lime  and  potassa  in  combination  with 
sulpliuric,  hydrochloric,  and  phosijhoric  acids. 

Anthracnose  of  the  Vine.| — This  disease,  known  in  France  as 
"  briileur  noir "  and  in  Germany  as  "  Brenner,"  and  widely  spread 
through  the  south  of  Europe  from  Portugal  to  Greece,  has  been  made 
a  subject  of  careful  study  by  11.  Prillicux.  He  identifies  it  with  tlie 
various  organisms  described  under  the  names  of  Spltacchmia  ampdinum 
by  Do  Bary,  Itamularia  ampclopliaga  by  Passerini,  Phoma  uvirula  by 
Arcangeli,  and  Gloiosporinm  ampeluphnr/um  by  Saccardo,  this  lust  pro- 
duciii'^  tljc  disease  known  in  Italy  as  "  vajuolo." 

The  disease  is  indicated  by  very  detinito  characters :  spots  of  a 
dark  brown  colour,  somewhat  depressed  in  the  centre.  Tluse  sjxtts 
api)ear  in  great  numbers  on  the  young  branches,  tendrils,  leaves,  and 
berries;  they  pouctrato  and  completely  destroy  the  tissue  in  tho 
places  where  thoy  are  developed ;  they  increase  at  their  circumference, 

*  'Jnnrti.    prnkt.    Clam.,'    xx.   p.   97.     See   'Journ.    Chcni.   Soc.,'   Ab.slr. 
xxxviii.  (IHSO)  p.  H'M. 

t  •  Bull.  Soc.  Bot.  France/  xxvi.  (187:»)  p.  324  t  Ibid.,  p.  TOS. 


672  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

and  frequently  coalesce  with  one  another.  Ultimately  the  ends  of 
the  branches  present  the  ajipearance  of  having  been  burnt ;  the 
berries  shrivel  up  or  drop.  The  spores  are  produced  in  great 
abundance,  and  are  colourless,  transparent,  and  oblong  in  shape. 
They  germinate  very  freely  in  water. 

Prillieux  adopts  for  this  fungus  Saccardo's  name  Gloeosporium 
ampelophagnm.  He  is  inclined  to  think  that  it  is  not  identical  with 
the  fungus  which  produces  the  well-known  "  black  rot "  of  the 
American  vines,  Phoma  uvicola,  and  that  it  is  probably  not  due  to 
American  importation. 

In  commenting  on  the  above  observation,*  M.  Cornu  disputes 
Prillieux's  statement  that  the  disease  has  been  known  both  in 
Germany  and  France  for  a  long  period,  even  a  century.  He  is 
disposed  to  identify  it  with  the  American  "  black  rot,"  and  to 
consider  that  it  has  been  introduced  into  Europe  with  American 
stocks. 

M.  Prillieux,  in  a  subsequent  communication,!  gives  further 
reasons  for  doubting  the  identity  of  the  anthracnose  with  the 
American  "  black  rot." 

Urocystis  Cepulse.J — M.  Cornu  has  made  some  further  observa- 
tions on  the  fungus  which  causes  the  disease  so  destructive  to  the 
onion  crop  in  America,  in  addition  to  those  already  recorded.§  In 
reference  to  Dr.  M.  C.  Cooke's  identification  of  the  sj^ecies  with  U. 
Colchici,  he  points  out  that  a  number  of  instances  are  known  in  which 
the  same  host-species  is  attacked  by  two  or  more  species  of  fungus 
all  belonging  to  the  Ustilagineae.  M.  Cornu  finds  that  the  parasite 
cannot  attack  the  tissue  of  the  host  when  the  plant  has  attained  to 
any  considerable  size ;  but  that  it  would  be  in  danger  of  spreading 
with  alarming  rapidity  by  attacking  very  young  seedlings  if  the 
crop  were  grown  year  after  year  on  the  same  soil.  This  he  believes 
to  be  the  reason  why  it  has  been  so  destructive  in  America,  and  has 
not  yet  attained  any  great  dimensions  in  Europe.  The  safety  of  the 
croj)  depends  on  the  transplantation  of  the  seedlings,  and  the  destruc- 
tion of  all  that  appear  weakly  or  sickly. 

Sterigmatocystis  and  Nematogonum.H — M.  G.  Bainier  gives  a 
detailed  account  of  the  structure  of  these  two  genera  of  fungi.  Of 
Sterigmatocystis  he  describes  seven  comparatively  large  species,  in 
which  the  sterigmata  are  very  much  shorter  than  the  basidia,  including 
one  new  one,  S.  carbonaria  ;  and  five  minute  species  in  which  the 
sterigmata  are  equal  to  or  larger  than  the  basidia.  All  these  were 
found  on  various  di'ugs.  The  description  of  Nematogonum  aurantiacum 
is  taken  from  specimens  found  on  the  clippings  of  a  shoemaker's 
shop. 

Mycotheca  Marchica. — Under  this  title,  Zo^jf  and  Sydow  are 
publishing  a  myco-flora  of  the  province  Brandenburg  in  Prussia,  the 

*  '  Bull.  Soc.  Bot.  France,'  xxvi.  (1879)  p.  319. 
t  Ibid.,  xxvii.  (1880)  p.  34.  J  Ibid.,  p.  39. 

§  See  this  Journul,  ii.  (1879)  p.  921,  and  ante,  p.  307. 
II  'Bull.  Soc.  Bot.  France,'  xxvii.  (1880)  p.  27. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  673 

first  century  of  wliicli  is  already  issued.  Six  new  species  are  de- 
scribed, viz.  Cyphella  pezizoides,  Puccinia  Sydoiviana,  Sclerotinia 
Batschiana,  CJuctomium  botrychodes,  Entyloma  bicolor,  and  Thielav'ia 
hasicola.  In  addition  to  a  complete  enumeration  of  the  myco-flora, 
the  work  will  contain  also  a  treatise  on  the  classification  of  fungi. 

Ceriomyces  terrestris.* — The  fungus  previously  described  under 
this  name  by  Schulzer  of  Miiggenburg,  and  referred  by  him  to  Corda's 
genus  Ceriomyces,  is  stated  by  the  same  authority  to  have  been  erro- 
neously so  referred,  and  to  belong  in  reality  to  the  genus  Dcedalia. 
He  has  now  found  it  in  three  distinct  forms,  differing  greatly  in 
appearance  and  habit,  but  always  retaining  a  uniformity  in  the  size 
and  form  of  the  sjiores,  nearly  spherical,  and  from  3  to  7  mm.  in 
diameter.  From  this  peculiarity  he  proposes  for  it  the  amended 
name  Dcedalia  lyolymorplia.  He  considers  it  to  be  a  transitional  form 
between  the  Clavariacei  and  the  Pileati. 

Vine-pock.t — Under  the  name  of  "  Pocken-kraukheit  "  is  known 
a  disease  of  the  vine  caused  by  the  parasitic  fungus  Gloeosporimn 
ampelophagum,  which  has  appeared  since  1876  in  Italy  and  the 
southern  provinces  of  Austria,  and  which  often  destroys  a  fourth  or 
even  a  half  of  the  crop.  The  fungus  forms  brown  spots,  with  a  grey 
or  reddish  bloom  in  the  centre,  which  are  at  first  nearly  circular,  but 
subsequently  often  coalesce.  They  consist  of  several  layers  of  pale 
brown  polyhedral  cells,  which  are  colourless  above,  and  are  there 
narrowed  into  short  sterigmata  or  conidiophores.  The  conidia 
(spores)  are  short,  elliptical  or  ovate,  colourless,  5-6  mm.  long,  and 
2 '5-3  "5  mm.  broad.  The  development  and  rapid  spreading  of  the 
fungus  depends  on  the  conditions  of  moisture.  It  is  recommended 
to  remove  and  burn  the  infected  parts. 

Prehistoric  Polyporus.| — Von  Thiimen  describes  a  piece  of  a 
Polyporua  collected,  among  other  prehistoric  objects,  in  the  pile- 
dwelling  station  in  the  neighbourhood  of  Laibach.  The  state  of  the 
jireservation  was  sufficient  for  the  structure  to  be  made  out  without 
difficulty,  and  for  the  fungus  to  be  identified  with  the  existing  Poly- 
porus  fomentarius.  It  may  have  grown  on  a  tree  in  the  station  itself, 
or  have  been  brought  in  from  outside  by  the  inhabitants  to  be  used 
for  the  purpose  of  tinder. 

Relationship  of  Ozonium  to  Coprinus.§  —  0.  Penzig  has  care- 
fully investigated  tlie  hintory  of  the  structure  known  as  Ozonium  Lk. ; 
and  has  come  to  the  conclusion  that  under  the  name  of  Ozouiinn 
auricomnm  have  been  united  a  lunubor  of  bodies  all  of  which  consist 
of  sterile  mycelia  of  various  stages  of  Coprinus,  wliich  greatly  resemble 
one  another,  but  which  exhibit  minuto  differences  in  their  size,  tlio 
diameter  of  the  hyphao,  tlie  transverse  septation,  &c.  From  among 
them  ho  proposes  to  establish  a  new  species,  Coprinus  intermcdius. 

*  'Ocator.  hot.  Z.itHchr.,'  xxx.  (ISSn)  p.  144. 

+  'Dio  rockon  <los  Wniiistockos,'  von  F.  von  Thiiinon,  Vienna,  ISSO.  St-o 
'  Bot.  CtntmlMult.'  i.  ( 1^80)  j).  17(5. 

X  '  ViTliftii.ll.  zo(.l.-l.ot.  (;.  .H.  Wien.'  xxix.  (IS80)  p.  :^2. 
§  '  Nuov.  (iiorii.  But.  Itnl.,'  xii.  (188(t)  p.  132. 
VOL.    III.  2    Y 


074  RECORD    OF    CURRENT   RESEARCHES    RELATING   TO 

Disease  of  the  Apple-tree  caused  by  Alcoholic  Fermentation.* — 
M.  Van  Tiegliem  calls  attention  to  the  conclusion  resulting  from 
M.  Miiutz's  observations,  that  alcoholic  fermentation  is  always  the 
result  of  a  single  condition,  viz.  when  a  living  cell  is  asphyxiated  or 
deprived  of  oxygen  in  the  presence  of  sugar.  He  finds  precisely  the 
same  conditions  occurring  in  nature  in  a  disease  of  the  roots  of  the 
apple-tree  observed  by  M.  Des  Cloizeaux  in  Normandy.  The  roots, 
which  were  very  old,  exhaled  a  strong  alcoholic  odour.  On  examina- 
tion it  was  found  that  neither  the  fibrovascular  bundles  nor  the 
vessels  exhibited  any  deterioration,  the  mischief  being  confined  to  the 
cells  of  the  medullary  rays  and  of  the  woody  parenchyma.  In  these 
the  ordinary  contents  had  been  entirely  replaced  by  brown  globules, 
alcohol  being  formed  abundantly  in  these  cells,  and  spreading  through 
the  tissues.  No  trace  of  microphytes  of  any  kind  was  observed.  The 
alcohol  had  evidently  taken  the  place  of  ordinary  sugar  and  starch ; 
and  its  formation  appeared  to  be  due  to  a  want  of  oxygen  in  the  soil. 
The  season  had  been  remarkably  rainy,  and  the  disease  was  con- 
siderably abated  by  draining  the  soil  or  by  digging  trenches  round  tlie 
root. 

Saccharomyces  apiculatus.f — E.  C.  Plansen  draws  attention  to 
the  inquiry  of  Brefeld,  What  is  the  original  source  in  nature  of  the 
germs  of  fungi  which  are  efficacioiis  in  the  process  of  fermentation  ? 
and  attempts  to  give  an  answer  to  this  question  in  the  case  of 
Saccharomyces  apiculatus  of  Eeess  and  Pasteur.  This  fungus  he  finds 
to  be  widely  distributed  on  ripe,  sweet,  succulent  fruits,  from  which 
it  is  dispersed  by  the  wind ;  it  occurs  also  on  unripe  fruits,  but  soon 
perishes  from  want  of  nutriment.  Eain  and  the  fall  of  the  ripe  fruit 
bring  it  to  the  ground,  where  it  passes  the  winter,  germinating  in  the 
following  summer. 

S.  apiculatus  does  not,  like  S.  cerevisice  and  other  ferments,  cause 
the  production  of  inversion,  and  is  therefore  unable  to  induce 
fermentation  in  saccharose,  such  as  a  solution  of  cane-sugar.  It 
corresponds  in  this  respect  to  certain  Mucorini,  and  is  a  far  less 
active  ferment  than  the  other  species  of  Saccharomyces. 

Plasmodia  of  Myxomycetes. — In  October  1879,  the  Eev.  H.  H. 
Higgins  collected  some  fragments  of  decaying  bark  and  wood  on 
which  were  growing  five  or  six  kinds  of  Myxomycetes.  The  specimens 
were  placed  on  a  bed  of  wet  sand  under  a  bell-glass,  for  observation. 

In  about  three  weeks,  upon  the  fragment  on  which  were  some 
small  portions  of  Fuligo  varians  Sommf  (JEthalium),  was  developed  a 
bed  or  cushion  of  olive-brown  jelly,  highly  charged  with  granules ; 
length  about  30  mm.,  breadth  10  mm.,  depth  3  or  4  mm.  The 
zoospores  had  not  been  noticed  previously  to  their  union  in  a  compact 
Plasmodium.  The  plasmodium  was  repeatedly  observed  both  as  a 
whole  and  in  detached  portions ;  but  it  was  very  sluggish,  and  the 
only  way  in  which  motion  could  be  "detected  was  by  getting  a  view  of 
the  mass  under  an  oblique  light,  when  some  slight  changes  could  be 

*  '  Bull.  Soc.  Bot.  France,'  xxvi.  (1879)  p.  326. 
t  •  Htdwigia,'  xix.  (1880)  p.  75. 


INVERTEBRATA,    CRTPTOGAMlAj    MICROSCOPY,    ETC.  675 

noticed  in  the  reflections  from  its  surface.  Its  margin  presented  no 
peculiar  features. 

Its  sluggishness  was  supposed  to  be  due  to  its  being  gorged  with 
food ;  and,  to  test  this  inference,  a  portion  of  the  plasmodium  was 
placed  in  a  drop  of  water  on  an  ordinary  glass  slide.  It  soon  became 
ditfused,  filling  the  drop  with  a  granular  jelly,  perceptibly  brown  in 
colour  though  paler  than  the  mass  from  which  it  had  been  taken. 
Still,  no  movements  could  be  seen,  and  signs  of  its  irritability  were 
altogether  obscure. 

To  eliminate  as  far  as  possible  the  results  of  satiety,  the  water  in 
the  drop  was  evai)orated  till  the  drop  became  a  gummy  or  viscid 
patch.  A  second  drop  of  piu'o  water  was  then  placed  on  the  slide,  the 
edge  of  the  drop  being  about  3  mm.  from  the  margin  of  the  viscid 
patch.  The  water  in  the  drop  w'as  then  led  to  the  edge  of  the  patch, 
forming  a  narrow  neck  of  water  between  the  two.  In  about  fuiir 
hours  the  protoplasm  of  the  patch  had  begun  to  pass  through  the 
neck,  leaving  all  the  granules  behind,  and  was  gathering  in  a  mass  on 
one  side  of  the  drop.  The  protoplasm  and  the  water  were  alike 
perfectly  pure  and  colomdess.  The  edge  of  the  protoplasm  could 
only  be  discerned  by  a  difference  between  the  refractive  power  of  the 
water  and  that  of  the  protoplasm,  now  highly  saturated  with  water. 
Why  the  protoplasm  kept  itself  together,  and  why  it  seemed  to  choose 
one  side  of  the  drop,  must  be  left  unexplained  ;  but  when  the  proto- 
plasm had  filled  rather  more  than  half  the  drop,  its  margin  on  the 
growing  edge  was  as  sharply  definite  as  the  outline  of  the  queen's 
head  on  a  new  sixpence.  Well-known  amoeboid  projections  were 
there,  and  others  unfamiliar.  The  protoplasm  was  now  evidently  in 
a  starved  condition,  and  was  putting  out  feelers  for  food.  The 
feelers  had  slow  motion,  but  the  author  was  unable  to  observe  the 
circulation  which  must  have  been  going  on  in  the  narrow  neck. 
Traces  of  extremely  delicate  interrupted  lines  could  be  seen  on  the 
surfiice  of  the  protoplasm,  apparently  diverging  from  the  narrow  neck. 

Before  another  opportunity  offered  for  rei)eating  the  experiment, 
some  change  took  place  in  the  plasmodium,  and  further  attempts  failed. 

Lichenes. 

Epiphora.* — This  genus  of  lichens  was  established  by  Nylandert 
out  of  Parmdia  cncausta,  and,  as  Minks  believes,  on  insufficient 
grounds.  He  considers  Nylander's  Epii)}iorn  encansla  to  bo  a  true 
lichen,  which,  however,  in  consequence  of  unfavourable  vital  con- 
ditions forms  neither  gonidia  nor  gonangia,  and  not  even  the  true 
hyphal  tissue  and  apothecia ;  so  that  it  cannot  even  be  separuto<l  as  a 
distinct  species,  much  less  genus. 

Nylander's  genus  Magriiop»if<  has  also,  according  to  the  same 
authority,  been  fouJidcd  on  insufficient  data. 

Lichens  of  Mont-Dore  and  Haute-Vienne.J  —  An  important 
analytical  catalogue  of  tbc  Lichens  of  tlicso  two  departments  by  Lnmy 

*  '  Flora,'  Ixiii.  (ISSO)  p.  105.  '  t  Ibid.,  lix.  (187(5)  p.  238. 

X  '  Bull.  S..C.  B(jt   France,'  vol.  xxv.  Is78  (1880)  p.  322.    Sw  '  Revue  Mvcol.," 
ii.  (1880)  p.  lOG. 

2  Y  2 


676  RECORD    OF    CURRENT    RESEAHCHES   RELATING   TO 

de  la  Cbapclle,  occupying  215  pages,  lias  just  been  published.  In  its 
arrangement  it  recalls  tbat  of  Dr.  Nylander's  '  Synopsis.'  Tbe  autbor 
bas  grouped  631  species  or  subspecies.  204  are  common  to  tbe  two 
districts;  109  are  peculiar  to  Mont-Dore,  and  318  to  Haute- Vienne  — 
tbat  is,  tbe  former  bas  313  lichens,  and  the  latter  522. 

Of  the  119  species  peculiar  to  Mont-Dore,  14  are  entirely  new, 
and  are  : — Stereocaulon  curtulum,  S.  acaulon ;  Parmeliopsis  subsore- 
dians;  Pannariairijptophylliza  ;  Lecanora  suhintricans  ;  Lecidea  aglmza, 
L.  instrata,  L.  planula,  L.  prcecontigua,  L.  badio-pallens,  L,  hadio- 
pallescens,  L.  instratula,  L.  umbriformis,  L.  thiojiholiza.  17  others  are 
new  to  France, 

With  regard  to  tbe  522  species  of  Haute-Vienne,  36  are  new, 
viz. : — 

Ephcebe  intricata  ;  Collema  chalazanellum  ;  Collemopsis  coracodiza  ; 
Stereocaulon  acaulon ;  Lecanora  scotoplaca,  L.  nigrozonata,  L.  sub- 
mergenda,  L.  immersata,  L.  Uparina,  L.  Biparti,  L.  conizella ;  Pertu- 
saria  leucosora,  P.flavicans  ;  Urceolaria  violaria  ;  Lecidea  submersula, 
L.  acervulans,  L.  terebrescens,  L.  acclinoides,  L.  albuginosa,  L.  chryso- 
teichiza,  L.  segregula,  L.  pauperrima,  L.  girizans  v.  opegrapMza, 
L.  Pichardi,  L.  conioptiza,  L.  modica,  L.  crepera,  L.  griseo-nigra, 
L.  sequax,  L.  gymnomitrii  ;  Melaspilea  deviella  ;  Endocarpon  leptopliyl- 
lodes ;  Verrucaria  Mortarii,  V.  chlorotella,  V.  viridatula,  V.  faginella, 
and  35  others. 

Tbe  catalogue  is  followed  (1)  by  some  notes  on  tbe  geographical 
distribution  of  the  species  and  the  nature  of  the  substratum :  the 
autbor  records,  amongst  other  remarkable  facts  in  botanical  geography, 
the  presence  on  tbe  central  plateau  of  France  of  P.  aquila,  which 
usually  frequents  the  sea-shore ;  (2)  by  a  glossary  of  some  technical 
words  frequently  employed  in  Lichenography ;  and  (3)  concluding 
with  an  alj)habetical  table  referring  to  the  numbers  in  the  catalogue. 

Algae. 

Morphology  of  Floridese.* — Tbe  subjects  treated  of  in  Agardb's 
most  recent  work  on  tbe  Floridefe  are  as  follows  : — 

I.  Tbe  general  appearance  and  external  parts  of  tbe  Florideae. 
(1)  General  appearance.  (2)  Increase  and  branching  of  tbe  external 
parts.  (3)  Tbe  root  and  the  formations  belonging  to  tbe  root- 
system.     (4)  Tbe  stem.     (5)  Branches  and  leaves. 

II.  The  structure  of  the  Floride^.  (6)  Nature  of  the  cell- 
membrane  and  cuticle.  (7)  Tbe  cell-contents  in  various  stages  of 
development,  and  in  diiferent  layers  of  the  thallus.  (8)  Tbe  con- 
nection between  tbe  various  cells,  and  the  means  by  which  this  is 
effected.  (9)  Tbe  various  processes  of  cell-formation,  (10)  Relation- 
ship of  position  and  grouping  of  tbe  cells ;  their  union  into  different 
layers, 

III.  Organs  of  reproduction.  (11)  The  antberidia.  (12)  Tbe 
spbferospore-fruit  and  spbasrosijore.  (13)  The  cystocarp  or  capsular 
fruit.     (14)  Views  in  relation  to  tbe  so-called  double  frixctification. 

*  "  Floiideornas  Morphnlop;i,"  '  Sv.  Vetenskaps-Akad.  Haiidl.,'  xv.  (1879) 
No.  6.     See  '  Bot.  Centralbl.,'  i.  (1880)  p.  33. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  677 

Bilateralness  in  Floridese.* — In  contradistinction  to  the  ordinary 
multilateral  structure  of  the  Floridefe,  some  instances  of  bilateral 
structure  have  been  described  by  Nageli  and  Kny  in  the  genera 
HerposiiiJionia  and  Basya.  These  and  other  examples  have  now  been 
more  closely  examined  by  Ambronn. 

The  nature  of  the  bilateralness  is  different  in  these  two  genera  ;  in 
the  former  we  have  an  instance  of  monopodial,  in  the  latter  of  sym- 
podial  ramification. 

In  the  first  species  described,  Bytiphloea  pinastroides,  the  apex  of 
the  stem  is  strongly  curved  inwards,  the  axis  of  the  stem  grows  by 
means  of  an  apical  cell  from  which  nearly  cylindrical  segments  are 
cut  off,  breaking  up  into  five  peripheral  and  one  central  cell.  The 
lateral  organs  are  leaves  and  axes.  The  leaves  stand  in  a  single  piano 
upon  the  convex,  tlie  axes  in  two  planes  on  the  concave  side.  The 
leaves  have  a  limited,  the  axes  in  general  an  unlimited  power  of 
growth.  The  former  consists  of  undivided,  the  latter  of  segmented 
cells.  The  leaves  branch  in  a  pseudo-dichotomous  manner,  the 
number  of  ramifications  being  at  most  six ;  the  ramification  of  the 
axes  generally  proceeds  to  the  fifth  order.  Growth  by  enlargement  of 
the  cells  commences  in  the  leaves  at  the  apex,  advancing  to  the  base, 
in  the  axes  in  the  reverse  order.  Both  those  divisions  by  which  the 
segments  break  up  into  five  peripheral  and  one  central  cell,  and  those 
which  result  in  the  formation  of  the  cortex,  commence  on  the  convex, 
and  advance  equally  on  both  planes  to  the  concave  side. 

Bytiphhiia  tinctoria  differs  from  R.  pinastroides  ma,inlj  in  the  outline 
of  the  stem  being  elliptical  instead  of  circular.  The  branching  also 
goes  on  to  the  seventh  degree. 

In  Eelicothamnion  scorpioides  the  axis  has  a  strongly  incurved  cone 
of  growth  as  long  as  it  is  in  active  growth.  The  lateral  structures  are 
exclusively  axes,  and  stand  alternately  right  and  left.  All  the  ramifica- 
tions lie  in  one  plane,  which  intersects  the  primary  plane  in  the  axis  of 
growth  of  the  primary  shoot  at  right  angles.  The  ramification  usually 
proceeds  to  the  sixth  degree.  The  stem  grows  by  an  apical  cell,  from 
which  cylindrical  segments  are  separated,  each  of  these  breaking  up  into 
from  four  to  seven,  usually  six,  peripheral  and  one  central  cell.  Each 
of  the  former  then  divides  again  by  a  septum,  the  commencement  of 
the  cortical  structure.  The  primary  axis  lias  unlimited,  the  lateral 
axes  limited  growth. 

In  Ilerposiphonia  fenelln  and  scciindn  the  axes  and  the  short  shoots 
(Kurztricbcn)  grow  by  means  of  an  apical  cell  which  is  repeatedly 
divided  by  septa;  the  number  of  segments  is  indefinite  in  the  long, 
definite  in  the  short  shoots.  Eacli  segment  breaks  up  by  longitudinal 
divisions  into  peripheral  cells  and  acentral  one,  the  nuinberof  the  former 
sometimes  amounting  to  as-  many  as  twelve.  The  lateral  structures 
on  the  axes  are  of  three  kinds,  root-hairs  or  rhizoids,  lateral  or  long 
shoots,  and  short  shoots.  Tlie  rhizoids  arise  from  the  first  pcriphoml 
cells  of  the  axes,  and  henco  on  tlieir  convex  side.  The  long  and  short 
shoots  are  formed  from  the  undivided  cells  in  strict  ncropctal  succes- 

•  •  l{..t.  Z.  it..'  xxxviii.  (iKMt)  p.  l»;i. 


678  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

sion  ;  but  at  first  the  long  shoots  lie  considerably  behind  the  short 
ones  in  growth.  The  long  shoots  stand  on  the  middle  line  of  the  two 
flanks  in  regular  alternation  right  and  left.  The  short  shoots  stand  on 
the  concave  side  in  two  planes  also  in  regular  alternation  right  and  left. 
Their  growth  closes  either  with  an  abortive  apical  cell  or  with  the 
formation  of  leaves.  The  leaves  arise  from  the  youngest  segments, 
and  even  from  the  apical  cell  itself ;  they  usually  consist  of  rows  of  cells 
branching  in  a  pseudo-dichotomous  manner.  The  leaves  which  are  not 
developed  from  the  apical  cell  stand  on  the  convex  side  of  the  short 
shoots.     There  is  no  formation  of  cortex  in  either  species. 

Fructification  of  Chsetopteris  plumosa.* — Although  the  peculiar 
fructification  of  the  Sphacelariaceae  has  been  described  in  several 
recent  treatises,  the  favourable  illustration  furnished  by  Chcetopteris 
j)lumosa  appears  hitherto  to  have  been  neglected.  This  deficiency  is 
now  supplied  by  E.  WoUny,  who  obtained  his  specimens  from  Spitz- 
bergen  and  Heligoland. 

This  Alga  usually  grows  on  rocks  and  stones  at  a  depth  of  from 
10  to  20  metres  below  the  surface,  and  is  therefore  very  difficult  to 
obtain  in  the  autumn  and  winter  months,  when  the  formation  of  the 
reproductive  organs  is  proceeding.  The  plant  is  also  subject,  in  its 
native  habitat,  to  a  pressure  of  water  of  from  one  to  two  atmospheres ; 
and  it  is  questionable  whether  the  processes  that  take  place  under  the 
abnormal  conditions  of  light  and  pressure  occurring  on  the  micro- 
scopic slide  would  be  the  natui'al  ones.  These  processes  appear  to 
be  completed  about  the  end  of  December;  there  being  two  distinct 
periods  at  which  fructification  is  produced,  in  autumn  and  in  winter. 
That  formed  in  the  autumn  is  very  scarce,  and  the  exact  function  of 
the  reproductive  bodies  the  author  was  unable  to  determine. 

In  winter  are  j)roduced  the  two  kinds  of  sporangia  characteristic  of 
the  Sphacelariaceae,  the  unilocular  and  the  multilocular. 

The  unilocular  sporangia  are  produced  in  various  positions  on  the 
fertile  leaves,  but  are  always  formed  out  of  terminal  cells.  They  are 
usually  spherical  and  of  a  dark  brown  colour,  with  granular  contents, 
which  in  all  probability  escape  in  the  form  of  numerous  zoospores,  as 
in  Cladosteplms. 

The  multilocular  sporangia  are  formed  on  special  fertile  leaves, 
and  are  quite  similar  in  external  form  to  those  of  Cladostephus,  as 
described  by  Pringsheim  ;  they  are  of  a  greenish-yellow  colour,  and 
are  divided  into  a  great  number  of  compartments. 

The  author  suggests  that  the  structures  described  by  him  as  the 
autumn  fructification  and  the  unilocular  sporangia  are  possibly  due  to 
the  attacks  of  parasitic  Chytridia,  a  phenomenon  so  well  known  in  the 
Si)hacelariacefe. 

Fructification  of  Squamarieae.t — Professor  Schmitz  has  made  this 
a  special  subject  of  study,  in  the  case  of  Cruoriopsis  cruciata,  a  small 
Mediterranean  seaweed,  which  forms  small  blood-red  or   black-red 

*  '  Hedwigia,'  xix.  (1880)  p.  65. 

t  '  SB.  Niederrliein.  Gcs.  Natur-  ii.  Heilkuude '  (Bouu),  Aug.  4,  1879. 


INVERTEBEATA,    CRYPTOGAMIAj    MICROSCOPY,    ETC.  679 

patches  on  stones,  slaclls,  &c.  The  thallus  is  formed  of  a  single  plate 
of  cells  which  increases  by  marginal  growth.  From  this  rise  in  a 
vertical  direction  simjile  or  dichotomously  branched  filaments  which 
are  enclosed  in  jelly  and  enveloped  in  a  common  cuticle.  The  tetra- 
sporangia  are  developed  on  certain  of  these  vertical  filaments,  branches 
of  which  suspend  their  apical  growth,  the  terminal  cell  developing  into 
a  tetrasporangium. 

On  tlje  same  plant  are  formed  also  the  sexual  organs,  antheridia 
and  "  procari)ia."  The  antheridia  arc  formed  by  rapid  cell-multipli- 
cation from  the  upper  end  of  special  filaments ;  the  procarpia  in  the 
same  way,  the  terminal  cell  of  a  filament  developing  into  a  long,  slender 
trichogyne.  But  in  addition  to  these,  procarjiia  of  a  second  kind  are 
also  formed,  in  the  shajje  of  short  lateral  3-5-celled  brandies  on 
numerous  filaments  of  the  thallus.  The  terminal  cell  of  these  lateral 
branches,  which  always  remain  imbedded  in  the  thallus,  does  not 
develop  into  a  trichogjnc,  but  retains  the  same  form  as  the  other 
cells.  After  the  trichogyne  of  the  first  kind  of  procarp  has  been  fer- 
tilized, a  filament  sjirings  from  its  base,  which  branches  and  spreads 
in  the  interior  of  the  thallus,  and  there  fertilizes  a  procarp  of  tlie 
second  kind  by  placing  itself  in  apposition  to  one  of  its  cells.  Some 
or  all  of  the  remaining  cells  of  the  procarp  swell  up  in  consequence, 
and  devcloj)  spores.  These  chains  of  spores  constitute  the  fructi- 
fication of  these  Algae,  to  which  Zanardini  has  given  the  name 
"  cystidia." 

In  other  species  of  Squamariea)  examined,  the  process  was  the 
same,  indicating  an  analogy  to  that  which  occurs  in  Dudresnaya. 

Fresh-water  Algse  of  Nova  Zembla.* — The  fresh-water  Alga3  col- 
lected in  Nova  Zembla  by  Dr.  F.  Kjollman  are  described  by  N.  Wille 
with  the  assistance  of  Professor  Wittrock.  The  total  number  of 
species  is  172,  belonging  to  57  genera.  Of  Desmidieaj  there  are 
100  species  belonging  to  13  genera  ;  the  following  new  forms  are 
described  and  figured : — Oocystis  (?)  Novce.  Semlice,  Sorasirum  (?) 
simplex,  Cosmarium  pseudislli'mochondrum,  subnofahile,  KJellmani,  and 
Novce  Scmlioi,  Staurastriim  KjeUmani  and  Novce  Semlice,  and  Gonatozygon 
Kjellmani.  Microspora  is  united  witli  Confctva,  and  the  mode  of  cell- 
division  in  the  latter  genus  minutely  described. 

Thermal  Anabsena.t — In  the  thermal  spring  known  as  Fontaine 
chaude  do  Dax,  at  a  temperature  of  57^  C,  II.  Serres  noticed  an  Alga 
which  lined  the  basin  beneath  the  surface  of  the  water,  and  wliicli  lio 
regards  as  Anahcena  thrmalis.  It  originally  develops  as  long,  slender, 
colourless,  coherent  filaments,  which  produce  small,  globular  organic 
bodies,  singly  or  arranged  in  rows.  The  cylindrical  filaments  finally 
become  mouiliform  and  curved.  The  separate  portions  afterwards 
develop  into  branches  which  may  be  Mmftiijochulus  laminostis  Cohn, 
and  which  combine  into  a  complicated  network.     Between  tlic  threads 

•  Ofvera.  af  kougl.  Vctensk-Aknd.  Furli.'  (1879),  p.  13.  Stc  '  Bot.  Ceiitmlbl.,' 
i.  (18S0)  p.  •^i,. 

t  '  iJull.  Sw.  de  Burdii  li  Dux,'  v.  (I8S0)  p.  i;i.  Stc  '  I!..t.  rLiitrall.l./  i.  (1S80) 
p.  2:^7. 


680  RECORD   OF   CURRENT  RESEARCHES  RELATING  TO 

filaments   were  also   observed,  wliicli   presented   a   resemblance   to 

Oscillatoria  labyrinthiformis. 

Polycystis  aeruginosa,  a  cause  of  the  Red  Colour  of  Drinking- 
water,*— In  a  garden-ditcb  in  a  village  in  West  Prussia,  from  tbe 
month  of  June  till  the  end  of  August,  1877,  and  again  in  1878,  the 
water  assumed  on  the  surface  during  the  day  a  burgundy  or  reddish- 
brown  colour,  changing  at  sunset  to  green.  This  has  been  determined 
by  Magnus  of  Berlin  to  be  caused  by  a  superficial  growth  of  the  Alga 
Polycystis  ceruginosa. 

Rain  of  Blood,  t  —  In  the  year  1878,  J.  Brun  noticed  on  the 
sacred  mountain  Djebel-Sekra,  near  the  sacred  city  of  Ouessin,  in 
Morocco,  a  so-called  "  rain  of  blood,"  which  he  found  to  result  from 
a  quantity  of  minute  shining  flakes,  which  adhered  closely  to  the  rocks, 
and  presented  an  extraordinary  resemblance  to  drops  of  blood.  These 
were  found  to  be  a  young,  undeveloped  condition  of  Protococcus  fluvi- 
atilis,  mixed  with  organic  remains  and  extremely  fine  sand.  The 
explanation  suggested  was  that  they  were  brought  by  a  strong  south- 
west wind  from  the  Sahara,  where  the  Protococcus  is  assumed  to  be 
extremely  abundant. 

Endoehrome  of  Diatomacese.l — M.  Petit  has  compiled  a  very 
useful  account  of  all  that  is  at  present  known  respecting  the  colouring 
matter  of  the  cell-contents  of  the  Diatomaceas,  a  full  translation  of 
which  is  appended  : — 

"  Hitherto,  so  far  as  I  know,  there  has  been  published  no  general 
work  on  the  endoehrome  of  the  Diatomacese.  There  is,  however,  no 
lack  of  papers,  but  they  are  scattered  through  the  numerous  works 
which  have  appeared  in  England,  America,  Germany,  &c.,  during  the 
last  fifteen  years.  I  am  going  to  attempt  to  collect  the  data  which  we 
possess  on  this  subject,  adding  some  of  my  own  personal  observations. 
I  have  considered  that,  for  clearness,  it  is  preferable  to  put  aside 
the  erroneous  opinions  which  inevitably  j)revailed  in  the  early  days 
of  the  study  of  this  very  interesting  group  of  unicellular  AlgaB,  and 
only  to  consider  those  which  have  been  recognized  as  correct  by  the 
greatest  number  of  observers. 

1.  Natureofthe  Endoehrome. — Every  one  knows  that  the Diatomacese 
are  distinguished  from  other  unicellular  Algae  by  their  envelope,  which 
is  formed  of  two  siliceous  valves  which  fit  one  in  the  other,  and  also 
by  their  colour,  varying  from  pale  yellow  to  dark  broicn.  They  owe 
this  particular  tint  to  a  coloured  plasma,  which  affects  (in  a  manner 
invariable  for  every  species  in  a  healthy  state),  sometimes  the  form  of 
lamince,  sometimes  that  of  granules. 

This  coloured  plasma,  called  by  Kutzing  §  gonimic  substance 
(^substance  gonimique)  is  now  known  under  the  name  of  endoehrome, 

*  '  Ber.  Versamml.  Westpreuss.  Bot.  Zool.  Ver.  Marienwerder.'  See  '  Bot. 
Centralbl.,'  i.  (1880)  p.  195. 

t  '  Bull.  Soc.  Belg.  Micr.,'  v.  (1880)  p.  55. 

j  '  Brebissonia,'  ii.  (1879-80)  p.  81. 

!^  '  Die  Kieselschiiligcn  Bacillarieu  oder  Diutomeen.' 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  681 

•which  is  not  applied  to  the  coloured  plasma  of  the  Diatomaccfe  alone, 
but  also  to  that  of  all  the  Algfe  in  general,  whatever  their  colour. 

The  endochrome  of  the  Diatomace<\}  does  not  give  up  its  pigment 
either  to  cold  or  boiling  water,  but  after  rather  prolonged  maceration 
it  is  completely  decolorized  by  cold  alcohol,  and  the  latter  acquires 
a  brownish-green  colour  of  greater  or  let^s  intensity. 

If  the  plasmic  masses  of  the  frustules  ai-e  examined  after  macera- 
tion in  the  alcohol,  they  will  be  found  unchanged  in  form.  They  are 
still,  as  before,  either  laminae  or  granules — they  have  only  lost  their 
colour.  The  plasma,  without  any  sensible  loss  of  form  and  without 
diminishing,  so  to  say,  in  volume,  has  yielded  up  all  its  pigment  to 
the  alcohol.  From  this  we  are  led  to  conclude  that  the  colouring 
matter  impregnates  the  plasmic  masses  contained  in  the  frustules,  in 
the  same  way  as  chlorophyll  impregnates  the  chlorophyll-bodies  in 
the  higher  plants. 

It  is  by  maceration  in  alcohol  that  the  pigment  is  extracted  from 
Diatomacese.  It  is  first  of  all  necessary  to  j^rocure  diatoms  free  from 
Oscillatoria  or  any  other  kind  of  alga  ;  wash  them  several  times  in 
fresh  water,  if  they  are  marine  species,  and  afterwards  in  distilled 
water ;  let  them  drain  for  some  time,  and  dry  them  rapidly  between 
sheets  of  filtering  paper.  The  diatoms  thus  prepared  are  then 
immersed  in  a  volume  equal  to  their  own  of  90  per  cent,  alcohol,  and 
left  to  macerate  protected  from  the  light.  As  soon  as  the  diatoms 
experience  the  contact  of  the  alcohol  they  take  a  very  distinct  green 
colour  and  the  alcohol  immediately  becomes  a  golden  yellow. 

After  six  or  eight  days  the  alcohol  has  taken  a  dull  green  colour 
more  or  less  inclining  to  brown,  and  the  diatoms  have  in  a  great 
measure  lost  their  colour  ;  but  it  is  only  after  a  month  or  more  of 
maceration  that  the  plasma  becomes  completely  colourless.  Filtered 
after  eight  days  of  maceration  we  obtain  a  concentrated  alcoholic 
solution  of  the  pigment. 

2,  Historical. — M.  Niigeli  *  was  one  of  the  first  to  mention  the 
colouring  i)rinciple  of  the  Diatomaccfc  and  describe  its  chemical 
properties.  He  considered  this  colouring  matter  to  be  simple,  and 
gave  it  the  name  of  diatomine,  which  wc  will  preserve,  because  of  its 
analogy  to  chlorophyll,  Avhich  is  itself  a  compound  body. 

However,  before  bim,  M.  de  Brcbissonf  first,  and  later  on 
Kiitzing,  J  had  remarked  that  "  Melosira  becomes  green  w'hen  dried 
upon  iiaper."  Kiitzing  had  moreover  proved  tliat  the  brown  coh)ur- 
ing  principle  becomes  green  under  the  influence  of  hydrochloric  acid, 
and  that  alcohol  removes  from  the  plants  a  green  pigment  resembling 
chlorophyll. 

In  18G7  M.  Askenasy  §  had  succeeded  in  isolating,  in  an  imperfect 
manner,  it  is  true,  the  two  colouring  princii)les  of  diatomin,  and  liad 
recognized  their  principal  chemical  and  optical  properties.  Although 
theio  experiments  were  not  at  the  time  considered  as  conclusive,  they 

*  '  Gathingcn  ciiizcU.  Algcn,'  p.  7. 

t  Biol)ia.-<on  iiml  (todcz,  '  Algiics  dcs  Environs  (h>  Falniso,'  \K\vt,  p.  11. 

X  '  HncMllftric'ii.'  p.  T^. 

§  "Biit.  /,.  Kiimt.  (kr  Clilninphylla-FiirbstunV,"  'But.  Zcit.,'  July,  IMiT. 


682  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

liave  nevertheless  been  confirmed  by  the  spectroscopic  observations  of 
M.  Nebelung  in  his  study  of  the  colouring  matters  of  some  fresh- 
water Alga3.* 

It  was  reserved  for  MM.  Kraus  and  Millardet  j  to  make  known 
the  true  nature  of  the  pigment  of  the  Diatomaceae.  They  succeeded, 
by  means  of  benzine,  in  separating  from  the  alcoholic  solution  of 
diatomiue  two  colouring  principles ;  one  giving  a  fine  golden  yellow 
solution  and  possessing  all  the  properties  of  phycoxanthine,  discovered 
by  the  same  authors  in  the  Algfe  of  another  group  ;  the  other  giving 
a  green  solution  having  properties  identical  with  tliose  of  chloro- 
phyll Kraus  and  Millardet  drew  this  conclusion  from  their  obser- 
vations, that  diatomine  is  formed  of  a  mixture  of  cldorophjjll  and 
-pliycoxan  thine. 

When  an  alcoholic  solution  of  diatomine  is  filtered,  a  fact  very 
simple  in  itself  gives  a  proof  of  the  presence  of  two  colouring 
principles.  If  the  filtering  paper  used  is  allowed  to  dry,  we  see  a 
broad  coloured  border  formed  round  the  margin  ;  the  outer  part  being 
tinted  yellow  while  the  inner  is  green. 

To  conclude  the  historical  part  I  will  cite  the  direct  spectrum 
analysis  made  in  1869  by  Professor  H.  L.  Smith  of  New  York,J  by 
means  of  the  microspectroscope.  The  spectrum  obtained  with  the 
small  portion  of  endochrome  from  a  single  diatom,  a  Navicida,  showed 
the  absorption-band  in  the  red  and  complete  absorption  of  the  second 
part  of  the  spectrum,  without  intermediate  bands.  This  spectrum 
would  seem  to  correspond  with  that  of  phycoxanthine.  (Fig.  54, 
No.  2.) 

(3)  Diatomine. — Let  us  now  see  what  are  the  physical  properties  of 
diatomine  and  of  each  of  the  elements  of  which  it  is  composed. 

A  concentrated  solution  of  diatomine,  prepared  according  to  the 
process  indicated  above,  has  a  green  colour  verging  on  brown  if 
examined  by  transmitted  light.  This  colour  may  be  more  or  less 
deep.  We  shall  see  further  on  to  what  cause  must  be  attributed 
this  variation  in  the  tint.  By  reflection  the  same  solution  has  a 
carmine  red  fluorescence  nearly  resembling  that  of  chlorophyll. 

Concentrated  sulphuric  and  hydrochloric  acids  give  to  the 
solution  of  diatomine  a  tint  of  an  intense  bluish-green,  and  different 
from  that  which  the  solution  of  chlorophyll  takes  with  the  same 
reagents. 

Ammonia  gives  no  apparent  reactions.  Lime-water,  and  especially 
baryta-water,  render  the  solution  of  diatomine  turbid,  without  produc- 
ing any  precipitate  similar  to  that  obtained  with  the  solution  of 
chlorophyll.§ 

If  a  concentrated  solution  of  diatomine  is  examined  by  the  spectro- 

*  "  Spectrosk.  Untersuch.  des  Farbstof.  einig.  Siisswasser-Algen,"  '  Bot.  Zeit.,' 
June  21,  1878,  pp.  394-395. 

t  "  Etudes  sur  la  matiere  colorante  des  phycochromacees  et  des  diatomees." 
(Extract  from  '  Me'm.  Soc.  Nat.  Sci.  Strasbourg,'  vi.  1868.) 

X  '  Sillimaii's  Journal,'  vol.  xxxviii.  (1869)  p.  83. 

§  Sec  for  furtlier  details  Ad.  Weiss,  'Zum  Bau  uud  dcr  Niitur  der  Dia- 
tomaceeu,'  p.  115. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  683 


684  RECORD   OF   CURRENT   RESEARCHES  RELATING   TO 

scope,  it  will  be  seen  that  its  spectrum  closely  approaches  that  of 
chlorophyll  (Nos.  1,  3,  4,  5).  Through  a  layer  of  two  centimetres' 
thickness  a  wide  black  band  can  be  seen  (I,,  Nos.  3-5),  with 
well-defined  edges,  in  the  red  from  107  to  112  between  the  B. 
and  C  Fraunhofer  lines,  and  three  small  bands  less  marked  and 
softened  off  at  the  edges,  one  (II.)  in  the  orange  between  C  and  D, 
from  97  to  102,  another  appearing  very  faint 'y  (III.)  near  the  yellow 
from  89  to  91,  and  finally  one  in  the  green  (IV.)  on  the  left  of  E, 
from  78  to  81.  The  second  part  of  the  spectrum  is  completely 
absorbed  as  far  as  F,  that  is,  to  the  limit  of  the  blue  and  green. 

The  .sensible  difference  between  the  spectrum  of  diatomine  and  that 
of  chlorophyll  relates  to  band  I. ;  with  diatomine  the  red  band  is 
withdrawn  as  far  as  113,  whilst  with  chlorophyll  this  band  stops  at 
111-5. 

A  very  thick  layer  of  the  solution  allows  nothing  to  pass  but  the 
rays  of  the  extreme  red,  and  a  few  of  the  yellow  ones  near  to  D. 

The  spectrum  which  I  have  just  described  is  that  which  is  most 
frequently  met  with ;  but  it  may  happen  that  the  bands  III.  and  IV. 
are  not  seen  in  the  spectrum,  although  bands  I.  and  II.  are  clearly 
marked.  These  differences  result,  as  will  be  seen,  in  a  variation  in 
the  composition  of  diatomine. 

(4)  Separation  of  the  two  Colouring  Principles. — To  separate  the 
two  colouring  principles  which  comi^ose  diatomine,  Kraus  and  Mil- 
lardet  employ  the  following  process  *  : — Some  diatoms  are  macerated 
in  alcohol,  as  has  been  mentioned  above.  "  After  some  days,  when  the 
alcohol  is  well  saturated,  the  solution  is  filtered,  and  into  it  is  poured 
from  two  to  three  times  its  bulk  of  pure  benzine.  It  is  necessary  to 
use  36  per  cent,  alcohol,  as  in  this  case  the  two  liquids  do  not  mix,  as 
would  happen  if  absolute  alcohol  were  used.  The  whole  is  put  into 
a  flask,  and  strongly  shaken  for  a  minute  or  two,  and  then  allowed  to 
settle.  The  yellow  colouring  principle,  being  more  soluble  in  the 
alcohol  than  the  green,  remains  dissolved  in  it,  whilst  the  benzine 
takes  up  the  green.  After  decanting,  the  alcoholic  solution  is  treated 
with  a  fresh  quantity  of  benzine,  again  shaken,  allowed  to  settle,  and 
decanted  ;  this  operation  is  repeated  until  the  benzine  ceases  to  be 
coloured  green."  To  isolate  the  two  colouring  principles  it  is  suffi- 
cient to  evaporate  the  solutions. 

The  process  of  Kraus  and  Millardet  has  the  inconvenience  of 
requiring  a  great  deal  of  time,  for  which  reason  I  prefer  to  employ 
the  following  process,  which  leads  more  rapidly  to  the  same  result. 

I  take  a  solution  of  diatomine,  prepared  with  90  per  cent,  alcohol, 
and  I  dilute  it  with  an  equal  volume  of  distilled  water  to  diminish 
the  strength  of  the  alcohol ;  the  solution  does  not  become  turbid. 
To  this  mixture  I  add  chloroform  in  quantity  equal  to  one-third  of 
the  total  volume.  After  shaking  it  for  a  minute  or  two  I  leave  it  to 
settle.  In  a  few  hours  the  separation  is  complete;  the  chloroform 
takes  up  the  green  colouring  principle,  and  sinks  to  the  bottom  of 
the  flask,  whilst  the  yellow,  which  is  more  soluble  in  weak  alcohol, 
remains  in  the  superficial  part.     After  decanting,  I  again  wash  with 

*  Loc.  cit.,  p.  2(5. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,    ETC.  685 

chloroform  in  tlie  same  way  as  before.  Usually  this  second  washing 
suffices  to  remove  all  that  remains  of  the  green  colouring  princii)lc. 
If  the  supernatant  portion  is  turbid  its  transparency  will  be  restored 
by  pouring  into  it  a  small  quantity  of  90  per  cent,  alcohol.  We  then 
have  the  two  colouring  principles  separately,  and  it  suffices  to 
evaporate  the  solutions  to  obtain  the  principles  in  a  solid  state. 

Green  Colouring  Matter — Chlorophyll. — The  solution  of  the  green 
colouring  matter  possesses  a  fluorescence  of  a  wine-red  colour ;  by 
transmitted  light  it  has  an  emerald  green  tint,  but  this  tint  may  bo 
more  or  less  deep.  The  properties  of  this  colouring  matter  show 
a  very  great  analogy  with  those  of  chlorophyll.  Its  spectrum 
(Fig.  54,  No.  3)  is  altogether  similar  to  that  of  chlorophyll  (No.  1)  ; 
the  band  III.  above  is  less  marked.  We  may  therefore  conclude 
with  Kraus  and  Millardet  {loc.  cit.)  that  the  green  colouring  matter 
extracted  from  diatomine,  either  by  benzine  or  by  chloroform,  is  no 
other  than  the  chlorophyll  of  the  higher  plants. 

A  proof  of  this  opinion  may  be  found  by  collecting  the  gas  which 
escapes  during  the  respiration  of  diatoms  exposed  to  the  light.  It  is 
easy  to  prove  that  this  gas  is  oxygen,  which  evidently  arises  from 
the  decomposition  of  the  carbonic  acid  by  the  chlorophyll  under  the 
action  of  light. 

Yellow  Colouring  Matter  Phi/coxanthine. — The  alcoholic  solution  of 
yellow  colouring  matter  has  a  brick-red  fluorescence,  less  intense 
than  that  of  diatomine.  By  transmitted  light  it  shows  a  fine  golden 
yellow  tint,  which  disappears  after  a  short  time  even  in  di  ft  used 
light.  If  this  solution  is  diluted  with  twice  its  bulk  of  distilled 
water  it  neither  precipitates  nor  becomes  turbid. 

Concentrated  sulphuric  and  hydrochloric  acids  communicate  to 
this  solution  a  greenish-blue  tint,  exactly  similar  to  that  of  certain 
Oscillatorieaj. 

If  we  examine  by  the  sjiectroscope  a  solution  of  yellow  colouring 
principle,  concentrated  and  completely  freed  from  chlorophyll,  wo 
find  (Fig.  54,  No.  2)  a  very  black  band  in  the  red  from  108  to 
113,  and  the  second  part  of  the  spectrum  is  absorbed  as  far  as  the 
middle  of  the  green  at  65,  decreasing  as  far  as  70.  The  band  I.  is 
displaced  towards  the  extremity  of  the  red,  and  docs  not  agree  with 
that  of  chlorophyll. 

All  the  physical  and  optical  properties  just  cited  show  that 
there  exists  a  great  analogy  between  the  phycoxanthine  of  Kraus 
and  Millardet  and  the  yellow  colouring  matter  of  diatomine  ;  there- 
fore I  do  not  hesitate  to  consider  them  identical,  as  do  these  two 
authors.* 

Kraus  a)ul  Millardet  have  proved  the  scarcely  perceptible  presence 
of  band  II.  in  the  spectrum  ot  i)hycoxiinthiiio  ;  the  cau.sc  of  tliis  result 
must  be  attributed  to  the  process  ciui)loyed  by  these  two  observei"S, 
the  benzine  not  succeeding  in  eliminating  the  last  truces  of  chh)ro- 
phyll. 

M.  Nebelung,t  in  using  the  same  process  to  scjiarato  the  two 
colouring  princijiles,  was  also  able  to  sco  with  groat  difficulty  band  II. 
*  Loc.  (it.,  \).  'S2.  t  l'"*"-  •"'• .  p  •'"••'^- 


686  RECORD   OF    CURRENT    RESEARCHES   RELATING    TO 

I  have  never  succeeded  in  seeing  this  second  band,  even  with  a  very 
thick  layer  of  solution  diluted  with  chloroform. 

(5)  Relation  hetxceen  the  two  Colouring  Principles. — We  will  now 
consider  to  what  cause  is  due  the  more  or  less  deep  tint  of  the 
different  species  of  Diatomacete. 

Chance  having  aided  me  in  my  researches,  I  have  succeeded  in 
gathering  pure  species,  and  comparing  inter  se  the  results  obtained. 
I  found  first,  in  March  1878,  very  pure  Diatoma  elongatum  in  the 
ditches  of  the  forest  of  Bondy;  secondly,  in  May,  Nitzschia  tenuis 
and  linearis,  with  some  N.  sigmoidea  in  the  watercress-beds  of 
Mitry;  thirdly,  in  September,  my  friend  Dr.  Leuduger  Fortmorel 
brought  me  from  Saint-Brieuc  a  large  collection  of  very  pure  Melosira 
nummuloides  ;  and  fom-thly,  I  was  able  to  collect  in  June  1879  a 
large  and  very  pure  quantity  of  Navicula  (^Schizonema)  ramosissima  on 
the  rocks  of  Dieppe,  where,  at  low  water,  the  fronds  can  be  removed 
one  by  one. 

It  is  the  spectra  obtained  with  the  solutions  of  diatomine  resulting 
from  these  various  gatherings  that  are  represented  in  Fig.  54,  Nos. 
4,  5,  6,  7. 

When  the  colouring  principles  are  separated  by  means  of  chloro- 
form it  is  seen  that  the  chloroform  assumes  a  dark  green  colour  with 
the  solutions  furnished  by  Melosira  and  Navicula,  whilst  it  only 
acquires  a  pale  green  tint  with  the  solutions  from  Nitzschia  and 
Diatoma  elongatum.  The  spectra  of  the  solutions  furnished  by 
Melosira  and  Navicula  show  the  four  bands  of  chlorophyll,  whilst 
the  solutions  from  the  two  other  species  only  show  bands  I.  and  II. 
The  first  two  species,  therefore,  contain  more  chlorophyll  than  the 
two  others,  and  as  they  have  a  browner  tint  it  must  also  be  concluded 
that  this  dark  tint  is  caused  by  the  abundance  of  the  chlorophyll. 

This  observation  clearly  shows  that  the  plasma  of  Diatomaceaa 
has  not  an  equal  capacity  for  chlorophyll,  whilst  their  capacity  is 
nearly  the  same  for  phycoxanthine.  Thus  the  relations  between  the 
two  colouring  principles  may  vary  enormously  from  one  species  to 
another.  This  fact  also  confirms  the  opinion  of  M.  Borscow,*  that 
the  variation  of  colour  in  the  different  species  is  due  to  the  excess  of 
one  of  the  two  pigments  over  the  other. 

Certain  diatoms  often  take  a  pale  green  tint  without  any  evident 
cause  [Navicula  viridis,  Fragilaria  virescens).  I  incline  to  the 
oijiuion  of  M.  Borscow,  who  attributes  this  colour  to  the  almost 
entire  disappearance  of  phycoxanthine  under  the  action  of  a  cause 
still  unknown. 

The  colour  of  the  Diatomaceas  varies  sometimes  in  a  sensible 
manner,  and  especially  it  becomes  darker  towards  the  time  of  the  act 
of  division,  afterwards  resuming  its  normal  tint. 

It  would  seem,  therefore,  that  the  proportion  of  chlorophyll 
increases  in  the  plasma  at  the  epoch  at  which  it  attains  its  maximum 
of  vital  force.  The  plasma  assumes  a  still  deeper  tint  shortly  before 
the  formation  of  the  auxospores,  but  resumes  its  natural  tint  as  soon  as 
the  silicification  of  the  cell  is  about  to  begin,  as  I  have  succeeded  in 
*  '  Die  susswas.  Diatomaceen  dea  Siid-Westlichens  Russlands,'  p.  67,  note  15. 


INVERTEBRATA,    CRYPTOGAMIA,    IIICROSCOPY,    ETC.  687 

proving  in  the  specimens  gathered  in  the  pond  of  Saint-Cucufa  in 
February  1877. 

Besides  these  transient  changes,  the  plasma  usually  preserves  a 
colour  of  its  own.  Thus,  Navicula  in  general,  Melosira,  Pleurosigma 
halticum,  Bhabdonema,  &c.,  present  a  very  dark  brown  colour,  whilst 
Gocconeis,  Nitzschia,  Siatoma  elonijaium,  AmpMprora  alata,  &c.,  only 
show  endochrorae  of  a  very  pale  yellowish-brown. 

If  we  examine  the  spectra  furnished  by  the  different  solutions  of 
diatomine  we  shall  see  that  the  bands  I.  to  IV.  of  chlorophyll  appear 
when  the  latter  exists  in  larger  quantity  than  the  phycoxanthine.  On 
the  other  hand,  the  bands  I.  and  II.  only  are  seen,  and  not  bands 
III.  and  IV.,  when  the  chlorophyll  exists  only  in  small  quantity. 
In  the  latter  case  it  is  the  spectrum  of  phycoxanthine  which  domi- 
nates, because  the  absorption  of  the  second  part  of  the  spectrum 
extends  to  63  and  decreases  to  68. 

(6)  Conclusions. — It  will  be  readily  understood  from  the  preceding 
that  certain  Diatoraacea3,  particularly  the  darkest,  Melosira,  Navicula, 
&c.,  may  become  green  by  desiccation.  In  this  case  the  jjhycoxan- 
thine,  which  is  very  unstable .  in  the  light,  disappears  first,  whilst  the 
chlorophyll  persists  much  longer. 

The  green  tint  which  the  Diatomaceae  take  under  the  action  of 
acids  is  communicated  to  them  by  phycoxanthine,  which  turns  green 
when  in  contact  with  acids. 

The  action  of  alcohol,  and  consequently  that  of  glycerine,  may  be 
explained  by  the  often  observed  fact  that  phycoxanthine,  being  more 
soluble  in  alcohol  than  chlorophyll,  is  separated  from  the  latter, 
which  remains  longer  inside  the  frustules  without  dissolving.  Per- 
haps also  the  alcohol  effects  a  simple  molecular  change  in  diatomine, 
and  separates,  by  isolating  them,  the  yellow  and  green  colom-ing 
principles,  which  were  intimately  mingled. 

To  sum  up  :  the  endochrome  of  the  Diatomaceae  contains  a  colour- 
ing substance,  diatomine,  which  has  much  analogy  with  the  chlorophyll 
of  tlic  higher  plants.  This  colouring  principle  splits  up  into  phy- 
coxanthine and  chlorophyll ;  but  the  proportions  of  these  two  colouring 
substances  varies  in  different  species.  The  Diatomaceae  which  are 
the  darkest  in  colour  are  those  which  contain  the  most  chlorophyll. 
Finally,  the  spectrum  of  diatomine  shows  a  great  analogy  to  that  of 
normal  chloroi>hyll." 

Belgian  Diatomaceae.  —  Dr.  H.  van  Ileurck,  of  the  Botanic 
Garden  of  Antwerp,  has  published,  with  the  aid  of  Hcrr  A.  Grunow, 
the  1st  part  of  a  Synopsis  of  the  Diatomaceae  of  Belgium,  which 
will  consist  of  6  parts,  with  heliographic  plates.  (Parts  1  and  2, 
Ilaphidea3 ;  Parts  3  and  4,  Pseudo-Rai)hiderc  ;  Parts  5  and  6,  Crypto- 
Raphidcae.)  Tlio  author  points  out  the  favourable  situation  of  Belgium 
as  regards  these  Algae  :  the  North  Sea  coast  furnishing  nearly  all  the 
marine  species  described  by  English  observers  ;  the  Ardennes,  a  f  ooil 
number  of  the  European  Alpine  species,  and  tlio  central  parts  of 
Belgium,  the  fresh-water  species  forming  the  foundation  <if  the 
European  flora. 

In  liis  preface  the  autlior  says  tliat  all  the  drawings  have  bfcn 


688  RECORD   OF    CURRENT   RESEARCHES   RELATING   TO 

made  with  the  greatest  exactness,  and  by  means  of  the  most  perfect 
objectives.  They  were  drawn  by  himself  or  under  his  eye,  and 
retouched  by  himself  or  Herr  Grunow,  who  has  also  drawn  the  plates 
of  some  of  the  groujis.  The  power  used  Avas  one  of  900  diameters 
for  the  easier  forms,  and  1500  for  the  most  difficult,  and  the  drawings 
•were  then  reduced  one-third  by  heliography.  Owing  to  the  care  that 
has  been  taken,  the  excellence  of  the  objectives,  and  the  use  of  helio- 
graphy, he  thinks  there  can  be  no  doubt  as  to  the  species  figured. 
"  Unhappily  one  cannot  say  as  much  for  the  greater  part  of  the 
drawings  of  diatoms  published  during  the  last  fifty  years,  a  great 
part  of  which  are  enigmas  more  or  less  insoluble  even  with  the  aid  of 
authentic  specimens." 

Dr.  Van  Heurck's  botanical  museum  contains  the  original  types 
of  the  principal  diatomographs — Kiitzing,  Walker- Arnott,  Eulenstein, 
De  Brebisson,  &c. 

New  Deposit  of  Diatomaceous  Earth. — At  the  May  meeting  of 
the  San  Francisco  Microscopical  Society,  the  President  announced, 
that  more  of  the  celebrated  Santa  Monica  diatomaceous  earth,  or 
some  similar  to  it,  had  been  discovered.  The  deposit  is  about 
seventy  miles  from  the  spot  where  the  original  piece  was  first  dis- 
covered by  Mr.  T.  P.  Woodward,  two  years  ago.  The  present  theory 
is  that  the  former  piece  became  detached  from  the  main  deposit, 
was  washed  into  the  sea,  and  then  carried  by  the  tide  to  the  shore 
on  which  it  was  found.  Professor  H.  L.  Smith,  of  Geneva,  N.Y., 
reported  by  a  letter  read  by  the  President  that  he  had  tried  the 
deposit  and  found  it  so  rich  and  so  nearly  like  the  "  Santa  Monica," 
that  he  desired  a  quantity.  Mr.  Norris  and  ex-President  Hyde  had 
also  made  a  careful  examination  of  the  material,  and  the  former  pre- 
sented a  mounted  slide  which  showed  forms  of  great  beauty  and  fully 
as  rich  as  the  original  of  two  years  ago. 

It  is  added  that  "  scientists  all  over  the  world,  it  is  to  be  hoped, 
can  now  be  supplied  with  this  very  interesting  material,  for  which 
they  have  been  so  anxious." 

Preservation  of  Solutions  of  Palmelline.* — Dr.  T.  L.  Phipson  says 
that  the  solution  of  palmelline  obtained  by  allowing  cold  water  to  stand 
for  a  day  or  two  over  the  air-dried  plant  (Palmella  cruenta),  as  described 
by  him,"!"  like  all  solutions  of  albuminoid  substances,  is  very  subject  to 
decomposition,  and  at  temperatures  of  75°-80°  F.  putrefaction  sets  in 
rapidly.  The  beautiful  rose  and  yellow  dichroic  tint  of  the  solution 
becomes  paler,  and  finally  disappears,  whilst  the  liquid  takes  a  strong 
ammoniacal  odour  and  swarms  with  Bacterium,  Vibrio,  and  Spirillum. 
The  latter  are  not  easily  to  be  distinguished  (except  by  their  small 
size  and  that  their  motion  is  more  rapid)  from  the  Spirillum  which  is 
present  in  the  blood  in  cases  of  relapsing  fever,  during  the  pyrexia 
only,  disappearing  as  the  temperature  of  the  body  falls. 

Various  methods  of  j)reserving  the  liquid  in  question  without  alter- 
ing its  composition  and  ojitical  j^roperties  were  tried.  Exclusion 
fi-om  air  and  light  were  only  partially  successful  for  short  periods. 
*  '  Chem.  News,'  xli.  (1880)  p.  21G.  f  See  this  Journal,  ante,  p.  319. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  689 

The  addition  of  a  little  salicylic  acid  modifies  tlie  delicate  purple-rose 
tint  and  destroys  the  dichroism,  so  that  tlie  orange-yellow  is  no  longer 
seen  by  reflection  ;  moreover,  it  only  preserves  the  liquid  for  a  week 
or  two,  after  which  the  phenomena  alluded  to  set  in  as  above  described. 
Finally  it  was  found  that  ether,  which  has  no  solvent  action  on  pal- 
melline  and  does  not  affect  its  composition  nor  coagulate  it,  may  be 
used  with  success  to  preserve  the  liquid  for  an  indefinite  period.  It 
is  sufficient  to  add  a  small  quantity  of  ether  to  the  solution  in  a  tube, 
cork  it,  and  turn  it  over  once  or  twice  so  as  to  dissolve  as  much  ether 
as  possible  in  the  liquid,  to  preserve  it  with  all  its  properties  for 
several  months.  As  long  as  the  contents  of  the  tube  have  a  strong 
odour  of  ether  no  decomposition  sets  in,  and  the  optical  properties  of 
the  palmelline  remain  intact. 

This  simple  method  of  preservation  may  be  found  applicable  to 
many  other  organic  substances  upon  which  ether  exerts  no  chemical 
action. 


MICROSCOPY,  &c. 

Looalities  for  Fresh-water  Microscopical  Organisms.  —  In  the 
recent  discussions  on  the  proposed  purchase  of  the  works  of  the 
Metropolitan  water  companies,  the  case  of  Birmingham,  where  they 
were  acquired  by  the  Corporation  authorities,  has  been  referred  to. 
London  microscopists  would  have  good  reason  to  rejoice  if  the 
result  that  has  been  obtained  in  Birmingham  were  repeated  here,  so 
that  an  abundant  supply  of  rare  and  interesting  species  of  Rotifers, 
Infusoria,  &c.,  should  be  brought  to,  or  rather  within,  every  micro- 
scopist's  doors,  without  the  drawbacks  of  pond-hunting.  In  Birming- 
ham the  ordinary  supply  of  water  for  drinking  and  other  purposes," 
received  through  the  pipes,  has  just  been  found  to  contain  the  rare 
Rotifer  Anunjia  longisjnna,  first  found  last  year  by  Professor  Kellicott 
of  Buffalo,  U.S.A. ;  *  also  A.  stipitata,  Triarthra  lonr/iseln,  Saljjina 
redunca,  Dinocharis  pncillum,  and  some  Tardigrada. 

Of  other  forms,  the  latest  addition  to  fresh-water  life  is  Ceratium 
longicorne,  very  plentiful,  but  few  living,  though  its  congener  Peridhiium 
fahulatum  seemed  none  the  worse  for  its  temporary  sojourn  in  the 
pipes.  Large  quantities  of  the  curious  compound  organism,  Dhwhrynn 
seriularia,  are  also  to  be  noted.  Tlic  Vorticellida3  and  Entomostraca  are 
represented,  the  former  by  both  branched  and  simple  forms,  and  the 
latter  principally  by  Bosmina  lomjirostrls,  with  his  two  long  and  curved 
autennii3,  evidently  much  the  worse  for  his  compulsory  visit  to  town, 
cither  the  distance  travelled  or  the  mode  of  transit  being  unsuitod 
to  his  well-being. 

Diatoms  are  mostly  present  in  the  stellate  spicies,  Astcriunella 
formosn,  with  a  few  specimens  of  Synedra  and  ricurosigmn,  while 
Desmids  are  fairly  plentiful  in  Palictstnim  rirannlnliim  and  Ihjtdothcca  ; 
also  Pandoriiia  morimi,  Clathrori/xlis,  and  other  algiv. 

]\[r.  J.  Levick,  from  whoso  paper  t  the  above  list  of  organisms 
is  taken,  suggests  that  their  presence  should  rather  be  considered  as 

•  See  this  Jouinul,  ii.  (1870)  p.  1 J7.  t  '  Mi'H-  Nut.,'  iii.  (1880)  p.  ICG. 

VOL.  III.  '2   •/. 


690  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

indicative  of  tlio  general  good  quality  of  the  water  than  otherwise,  as 
some  of  them,  at  least,  arc  known  at  home  and  abroad  as  the  inliabi- 
tants  of  deep,  clean  water  only. 

It  is  curious  that  hitherto  neither  Leptodora  hynlina  nor  Hyalo' 
daphnia  Kalhergensis  have  been  found  by  London  microscopists,  and 
yet  it  cannot  be  doubted  that  it  must  be  as  plentiful  in  the  neighbour- 
hood of  London  as  of  Birmingham.  For  tlie  former  a  deep  reservoir 
Kecms  to  bo  essential,  the  net  being  dipped  G  or  7  feet. 

Collection  of  Living  Foraminifera.* — Having  been  occupied  for 
some  years  in  the  study  of  the  rhizopodous  fauna  of  the  coasts  of 
France,  M.  Vandcn  Brocck  thinks  it  may  be  useful  to  those  similarly 
occupied  to  publish  instructions  with  a  view  of  facilitating  the  collec- 
tion of  Foraminifera.  The  original  instructions  are  very  concise  and 
thoy  necessarily  suffer  in  the  further  condensation  which  we  have  been 
obliged  to  give  them. 

In  general,  the  coarse  and  purely  quartzose  sand  is  very  poor  in 
Foraminifera,  though  under  certain  favourable  conditions  interesting 
results  may  bo  obtained,  when  for  instance  it  contains  a  sufficient 
quantity  of  the  debris  of  shells,  sponges,  algfc,  &c. 

The  tide  often  washes  up  on  the  shores  of  an  indented  coast  a 
kind  of  littoral  band,  at  high-water  mark,  consisting  of  algfe  and  light 
debris  of  shells,  sponges,  &c.,  which  generally  furnishes  good  material 
for  the  collection  of  Foraminifera.  The  debris,  if  it  contains  many 
algse,  should  be  washed  in  an  abundance  of  water,  lightly  rubbing  it 
between  the  hands.  To  preserve  the  Foraminifera  alive,  salt  water 
must  be  used  ;  fresh,  if  the  shells  only  are  desired,  the  latter  pre- 
venting the  saline  efflorescences  which  would  otherwise  cover  the  shells. 
The  floating  residue  must  be  thrown  away,  carefully  preserving  the 
sand  deposited  in  the  vessel.  Precautions  must  be  taken  not  to  throw 
away  the  Foraminifera,  which,  being  lighter  than  the  grains  of  quartz, 
float  above  the  sand,  under  (not  on  the  surface  of)  the  water.  The 
water  can  also  be  filtered  through  coarse  muslin  and  the  residue  of 
algfe,  &c.,  rejected. 

The  algfe  gathered  on  the  beach,  or  better  still,  taken  from  the 
place  of  their  growtli,  give  equally  good  results.  It  is  useful  to 
preserve  unwashed  a  few  roots  of  algfe  and  flexible  polyps,  as  a  great 
number  of  living  Foraminifera  are  attached  to  the  leaves  and  false 
roots. 

We  sometimes  find  on  the  coast,  amongst  the  shells  and  Fora- 
minifera of  recent  fauna,  others  coming  from  fossil  beds,  tertiary, 
cretaceous  or  otherwise,  which,  bordering  on  the  sea,  are  worn  away 
by  the  action  of  the  waves,  or  crumble  into  it  from  the  cliffs  which 
are  undermined  at  high  tide.  Thus  fossil  Foraminifera  become  dis- 
persed among  the  recent  fauna,  and  it  is  therefore  very  important  to 
take  into  consideration  the  neighbourhood  in  which  the  sand  has  been 
collected. 

In  the  coarse  sand  and  residues  of  the  shore  we  generally  find 
nothing  but  rolled  and  worn  Foraminifera  belonging  exclusively  to 

*  '  .Toiirn.  fk  Micrngr.,'  iii.  (1879)  p.  237. 


INVERTEBUATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  691 

the  large,  thick-slicllcd  species;  those  with  fragile  and  delicate  shells, 
that  is  to  say  the  most  luimci'ous  and  beautiful,  can  only  live  and 
develop  properly  on  muddy  bottoms,  or  where  the  sand  is  fine  and 
somewhat  slimy,  and  it  is  necessary  therefore  to  investigate  such 
deposits  also.  For  this  purpose,  some  of  the  following  indications 
may  be  followed  according  to  the  locality. 

Collect  at  low  water  (cither  with  the  hand  or  a  small  dredge)  the 
superficial  portion  of  the  mud  or  slimy  sand  found  in  ports  or  the 
mouths  of  rivers,  or  higher  up  in  their  course  if  the  water  is  salt. 
The  glutinous  coating,  generally  green  or  brownish,  which  covers  tho 
mud  or  slimy  sand  in  quiet  places  often  gives  excellent  results.  The 
thick  black  rnud  beneath  is  less  rich  in  Foraminifcra  than  the  upper 
portions. 

It  is  also  useful  to  explore  tho  large  pools  which  remain  at  low 
water,  either  on  the  shore  when  the  sand  is  not  too  coarse,  or  in  the 
estuaries,  or  even  the  cavities  often  met  with  among  the  rocks  or  at 
the  foot  of  clifls.  It  must  be  remembered  that  the  most  favourable 
spots  are  always  those  which  are  covered  with  very  fine  or  slimy  sand. 
Sediments  which  are  coarser  but  rich  in  fine  debris,  are  also 
favourable. 

Whitish  zones  are  sometimes  seen  on  the  margins  of  pools  left  at 
low  tide,  composed  of  little  heaps  accumulated  in  the  numberless 
ridges  produced  in  the  sand  by  tlio  retreating  water.  These  whitish 
heaps  consist  of  small  organic  debris,  spiculro  of  sponges,  si)ines  of 
echinoderms,  fragments  of  shells,  &c.,  often  mixed  with  a  quantity  of 
Foraminifcra,  of  which  a  great  many  can  be  collected  by  a  spoon. 

By  means  of  a  simple  magnifier  the  presence  of  living  Foraminifcra 
can  be  established  on  the  spot.  If,  for  example,  some  of  the  deposit  is 
examined  in  a  shallow  vessel  (such  as  the  cover  of  a  tin  box)  and 
under  a  small  quantity  of  water,  the  Foraminifcra  will  bo  readily 
recognized  as  small  coloured  points  of  red,  rose,  or  yellow — tints 
which  are  given  to  the  thin  shell  of  many  species  by  the  colour  of  tlie 
sarcode  within. 

Tlie  places  whei'o  the  water  is  relatively  quiet  arc  the  only  really 
fav«)urablc  ones  for  finding  Foraminifcra.  13redgings  from  a  dei)th  of 
from  8  to  10  metres  (when  the  water  at  tho  bottom  is  little  moved, 
however  rougli  it  may  be  on  the  surface),  always  give  good  results, 
unless  tlic  bottom  consists  of  })urely  quartz  deposit  or  gravel,  as  is  tlie 
case  in  regions  subjected  to  rapid  submarine  currents,  as  in  the  Straits 
of  Dover.  Tho  interest  of  tho  collecti(ms  increases  in  proportion  to 
the  depth  at  which  tlicy  liave  been  made. 

For  the  benefit  of  those  who  liavo  not  dredges  at  their  command, 
it  may  be  mentioned  that  the  mud  brought  on  board  by  tho  anchors 
of  ships,  or  the  detritus  on  tho  nets  of  fishermen,  furnish  sj)ocies  which 
are  not  found  on  the  coast. 

Foraminifcra  may  also  be  found  in  tho  contents  of  tho  stomachs  of 
fishes,  molluscs,  crustacea,  actinisp,  mednsjo,  salpio,  i^'c. 

Certain  species  of  Annelida,  Tf rebel Uv.  for  instance,  form  a  pro- 
tecting sheath  wliich  often  contains  Foraminifcra  not  found  on  the  shore. 

'J'ho  sand  and  slinio  oi  salt  marshes  in   ncrioilical  connnunieation 

2  z  2 


692  KECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

with  the  ocean  furnisli  species  which  almost  exclusively  inhabit 
brackish  water,  and  others  which  present  special  characters. 

In  the  same  way  as  the  cases  constructed  by  the  larvfe  of  the 
Phryganeidse  give  in  fresh  water  a  rich  harvest  of  small  shells  and 
Entomostraca,  so  also  in  brackish  water  they  contain  Entomostraca 
and  Foraminifera  often  of  rare  and  interesting  species. 

Oyster  and  mussel  beds  are  also  favourable  spots,  but  in  examining 
Foraminifera  from  artificial  oyster-beds  it  must  be  taken  into  con- 
sideration whether  the  oysters  are  of  French,  English,  American  or 
other  origin,  as  Foraminifera  foreign  to  the  region  may  be  found 
which  were  originally  brought  there  with  the  oyster  shell. 

In  a  given  locality  many  variations  are  found  in  the  faunal 
elements,  according  to  the  time  of  collection ;  it  is  advisable,  there- 
fore, to  collect  at  different  seasons,  and  during  two  or  three  consecutive 
years,  if  the  fauna  is  to  be  thoroughly  studied.  Changes  of  temperature 
are  caused  by  currents,  especially  deep  currents,  which  thus  influence 
the  fauna  of  the  bottoms  over  which  they  pass  as  well  as  by  the  foreign 
matter  which  they  bring.  It  will  be  useful  therefore  to  find  out 
whether  they  are  hot  or  cold,  periodical  or  continuous,  and  to  know 
their  origin  and  direction. 

In  conclusion,  the  author  points  out  that  his  instructions  apply 
equally  to  the  Entomostraca  which  generally  accompany  Foraminifera 
in  their  different  habitats. 

Cleaning  Foraminifera.* — After  having  read  Mr.  Vorce's  article 
on  cleaning  Foraminifera,!  it  occurred  to  Mr.  K,  M.  Cunningham  to 
use  electrical  force  to  extract  the  shells  in  the  dry  way.  For  this 
purpose  he  used  a  small  tin  lid,  4  inches  in  diameter,  filled  with  a 
preparation  of  rosin  and  sealing-wax,  the  resinous  surface  of  which, 
for  convenience,  he  excited  with  an  artist's  brush,  known  as  a  "  badger 
blender."  The  sand  from  sponges  or  foramiuiferous  marl  is  spread 
thinly  over  as  large  a  surface  as' convenient ;  the  cake  of  rosin  is  then 
excited  by  passing  the  badger's-hair  brush  over  it  several  times,  and 
then  turning  the  excited  surface  of  the  resinous  cake  down  to  within 
a  quarter  of  an  inch  of  the  material,  and  passing  it  gently  over  it. 
The  result  will  be  that  innumerable  light  particles  will  be  attracted 
to  the  excited  surface,  and  will  remain  there,  while  the  sand  will 
be  attracted  and  repelled,  thereby  leaving  a  large  percentage  of 
Foraminifera,  spicules,  &c.,  adhering  to  its  surface,  which  may  then 
be  brushed  off"  into  any  suitable  receptacle.  The  above  plan  may  be 
tested  on  a  small  scale  by  exciting  the  end  of  a  large  stick  of  sealing- 
wax.     Damp  weather  is  unfavourable  for  the  experiment. 

Wax  Cells.f — Eeferring  to  Dr.  Hamlin's  note  on  this  subject,§  it 
is  suggested  (1)  that  before  applying  pressure  to  the  outer  edge  of  the 
disk  a  little  turpentine  should  be  applied  to  the  lower  surface  with  a 
brush  extending  to  the  proposed  width  of  the  ring,  and  (2)  that 
instead  of  a  sliglit  moistening  of  the  knife-blade,  water  should  be  used 
freehj. 

*  '  Am.  M.  Micr.  Journ.,'  i.  (1880)  p.  88.  t  ^nfr,  p.  497. 

X  'Am.  M.  Micr.  Jouru.,'  i.  (1880)  p.  98.  §  Ante,  p.  507. 


mVERTEBRATA,   CRYPTOGAMIA,   MICEOSCOPY,   ETC,  693 

Carbolic  Acid  for  Mounting.* — Mr.  F.  Barnard,  of  Kew,  Victoria, 
writes  tliat  some  years  ago  he  mentioned  the  use  of  carbolic  acid  (the 
best  crystallized  with  just  sufficient  water  to  keep  it  fluid)  in  mount- 
ing microscoi)ical  objects,  and  is  led  to  believe  that  the  subject  is  com- 
paratively unknown  in  England,  though  in  use  in  Victoria  more  than 
ten  years,  and  to  such  an  extent  that  turpentine  is  seldom  used  in 
many  studios.  The  first  specimen  he  saw  it  tried  upon  was  the  head 
and  jaws  of  a  spider  mounted  by  Mr.  Ralph,  the  President  of  the 
Microscopical  Society  of  Victoria,  which  led  Mr.  Barnard  to  try  it  in 
various  ways  to  render  objects  transparent,  and  now  he  seldom  uses 
anything  else.  Whether  it  is  animal  or  vegetable  tissue  the  eflect 
will  be  the  same,  the  acid  will  in  a  very  short  time  render  the  object 
transparent,  and  the  Canada  balsam  will  when  applied  run  in  as 
readily  after  it  as  turpentine. 

In  the  case  of  such  an  object  as  a  palate  of  a  mollusc,  wash  it  well 
in  water  and  remove  it  to  a  bottle  of  the  acid  for  a  few  hours,  or  if  it 
is  desired  to  mount  it  at  once,  place  it  after  washing  on  a  glass  slip 
in  proper  position  for  mounting  and  drop  one  or  two  drojjs  of  the 
acid  on  it.  At  first  it  will  look  thick  and  cloudy  ;  warm  the  slide 
over  the  spirit  lamp,  let  it  cool,  and  drain  oJBf  the  acid ;  if  not 
perfectly  clear  when  cold,  apply  some  fresh  acid  and  warm  again  ; 
place  on  a  cover  if  not  previously  done,  and  apply  the  balsam,  by 
means  of  a  little  heat  it  will  run  under.  With  polyzoa  the  easiest 
plan  is  to  jilace  them  in  a  little  hot  water  which  softens  them,  tlien 
lay  them  out  on  a  glass  slip  ;  place  another  on  it  which  is  of  suflicient 
weight  to  keep  them  in  position  while  they  dry,  then  drop  them  into 
a  bottle  of  carbolic  acid  and  soak  for  a  time ;  twenty-four  hours  will 
render  any  polyzoa  transparent  without  rendering  them  brittle,  and 
the  author  says  he  has  mounted  specimens  perfectly  clear  and  trans- 
parent in  ten  minutes  from  the  time  they  w^ere  alive  in  the  zoophyte 
trough,  ti'eating  them  as  above  recommended  for  palates.  For 
gizzards  and  parts  of  insects  he  also  considers  that  nothing  cornea 
near  it. 

One  great  advantage  carbolic  acid  has  over  turpentine  is  that  it 
never  renders  specimens  brittle.  They  can  be  pulled  about  as  readily 
as  when  frcsli.  Should  there  over  be  any  clouding,  it  arises  from  the 
moisture  of  the  object,  not  from  the  carbolic  acid,  but  from  want  of 
it.  It  is  comparatively  inexpensive,  far  less  unpleasant  in  smell,  and 
not  so  sticky  and  dirty  in  use  as  turpentine.  It  is  not  necessary  to 
let  the  object  dry,  which  invariably  alters  the  shape  more  or  less ; 
still,  should  it  be  dry  it  is  not  any  time  becoming  transparent  com- 
pared with  the  old  process  of  soaking  in  turpentine.  We  all  know 
how  difficult  it  is  to  render- Foraminifcra  transparent  and  free  from 
air  ready  for  mounting  in  balsam.  One  trial  of  carbolic  acid  will 
convince  the  most  sceptical  of  the  advantages  it  has  over  turpentine, 
benzine,  &c.  The  only  drawback  to  its  use  is  that  it  often  renders 
some  vegetable  tissues  too  transi)arcnt. 

Double-staining  of  Vegetable  Tissues.!— Ill  this  paper  the  writer 
(who  only  givts  an  initiiil)  says  tliut,  having  used  a  number  of  dyes  in 
♦  'Sci.-Go.ssi|>,"  1880,  ]\  I'M.  +  '  Ain.  M   Mii-r.  J,.nrn.,'  i.  (1880)  p.  81. 


694  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

double-staining  vegetable  tissues,  the  conclusion  he  has  arrived  at  is, 
that  no  rules  can  be  given  which  will  ensure  success  in  every  case. 
The  process  is  familiar  to  every  working  microscopist,  but  the  limited 
number  who  have  fairly  succeeded  in  differentiating  the  tissues  is 
somewhat  surprising.  In  his  own  experience  he  has  met  with  some 
sections  which  obstinately  refused  to  act  as  they  should  under  the 
operation  of  the  two  colours,  but  even  these,  with  patient  manipula- 
tion, can  be  induced  to  show  some  results,  even  though  they  may  not 
exhibit  that  sharpness  and  purity  which  it  is  the  aim  and  object  of  the 
mounter  to  obtain. 

A  writer  in  '  Science-Gossip  *  has  come  nearer  to  the  true  laws 
governing  the  process  than  any  one  who  has  written  on  the  subject ;  he 
has  at  least  indicated  the  direction  in  which  the  practical  worker 
must  look  to  attain  success.  The  theory  of  the  present  author  is 
slightly  different,  and  consequently  his  process  varies  somewhat,  but 
in  the  main  it  is  the  same.  The  capacity  for  staining  tissue  resides 
more  in  the  colours  than  in  the  tissue  itself.  A  stain  may  be  per- 
manent, unless  it  is  driven  out.  It  may  be  driven  out  by  some 
solvent,  by  some  bleaching  process,  or  lastly  by  some  other  colour. 
Some  tissues  hold  the  stain  more  tenaciously  than  others,  probably  on 
account  of  their  varying  density.  Thus  the  spiral  and  bass-cells  will 
retain  a  colour  longer  under  the  influence  of  a  solvent  than  the  softer 
and  more  open  parenchymal  cells.  He  endeavours  to  take  advantage 
of  this  property  by  giving  the  whole  tissue  all  of  one  colour  that  it 
can  be  induced  to  take,  and  then  driving  it  out  of  the  parenchymal 
tissue  by  a  stronger  colour,  stopping  the  process  at  the  moment  when 
the  second  colour  has  completely  replaced  the  first  colour  in  the  soft 
tissues,  and  before  it  has  begun  to  act  upon  the  more  dense  cells.  If 
a  section  be  stained  with  roseine  and  then  be  left  long  enough  in  a  solu- 
tion of  Nicholson's  blue,  the  whole  section  will  be  blue,  with  no  visible 
trace  of  red.  If  it  be  taken  out  before  the  blue  has  permeated  the 
entire  tissue,  the  red  will  show,  in  some  parts,  quite  clear  and  well- 
defined  among  the  surrounding  blue  tissues.  Following  out  this  prin- 
ciple, that  exact  point  must  be  determined  when  the  blue  has  gone  far 
enough. 

In  practice  the  theory  is  carried  out  as  follows :  A  two-grain 
neutral  solution  of  eosin  is  used,  and  in  this  the  prepared  sections  are 
preserved  until  the  operator  is  ready  to  use  them.  They  keep  per- 
fectly well  in  this  solution,  and  are  always  ready  to  undergo  the  final 
process,  which  requires  but  a  very  short  time  before  they  can  be  placed, 
fully  fiinished,  under  the  covering  glass.  After  taking  them  from  the 
eosin  solution,  they  should  be  passed  through  95  per  cent,  alcohol, 
merely  to  wash  off  the  superfluous  colour,  and  then  placed  in  a  half- 
grain  solution  of  Nicholson's  blue  made  neutral.  The  time  required 
in  the  blue  solution  varies  with  different  tissues,  and  in  the  nice  adjust- 
ment of  this  time  lies  the  whole  success  of  the  operation.  Three  or 
four  sections  of  each  kind  are  generally  spoilt  in  determining  the  exact 
time  required.  A  section  is  taken  from  the  eosin,  holding  it  lightly  in 
a  pair  of  forceps,  rinsed  off  rapidly  in  alcohol,  and  then  immersed  in 
the  blue,  still  in  the  forceps,  while  ten  can  be  counted  with  moderate 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,    ETC.  695 

haste.  Then  quickly  place  it  iu  clean  alcohol,  and  brush  lightly  with 
a  camel's-hair  brush.  This  immersion  in  clean  alcohol  seems  to  check 
the  operation  of  the  blue  instantly.  It  should  then  be  examined  under 
a  1-inch  objective  to  determine  whether  the  exact  point  where  the 
blue  and  the  red  remain  distinct  has  been  reached.  If  the  blue  has 
not  occupied  all  the  softer  cells,  another  section  should  be  taken  and 
put  through  the  same  process,  counting  twelve,  and  so  on,  until  the 
proper  point  is  reached  ;  or,  on  the  other  hand,  decreasing  the  count 
if  the  blue  has  infringed  upon  the  red  in  the  more  dense  tissue.  Having 
thus  determined  the  count  for  the  sections  of  that  particular  material, 
the  remainder  of  the  sections  are  passed  through  tlie  blue  into  the 
alcohol,  merely  counting  off  the  immersion  of  each  section.  Then 
place  the  sections  for  a  few  moments  in  absolute  alcohol,  which  seems 
to  fix  the  colours,  then  through  oil  of  cloves  into  benzole,  and  moiint 
in  dammar  and  benzole.  It  is  sometimes  advisable,  with  delicate  tissues, 
to  merely  rinse  off  the  blue  in  95  per  cent,  alcohol,  and  fix  the  colours 
at  once  in  absolute  alcohol,  but  every  operator  will  learn  the  minor 
details  for  himself  in  the  manipulation. 

Of  course,  with  the  "  rule  of  thumb  "  method  of  counting  off  the 
time  slight  variations  will  occur  which  will  mar  the  beauty  of  the 
finished  product ;  besides  which  minute  differences  in  the  thickness  of 
the  section  will  affect  the  result,  and  even  a  distance  of  a  quarter  of 
an  inch  iu  the  same  stem  will  make  a  difference  in  the  density  of  the 
tissue,  which  will  be  obvious  in  the  sharpness  of  the  colours  under  the 
objective,  so  that  the  operator  should  not  be  disappointed  if  out  of  a 
dozen  slides  only  four  should  be  worth  preserving.  The  others  can 
go  into  the  borax-pot  to  be  cleaned  for  another  operation.  The  beauty 
of  those  which  do  pass  inspection  will  amply  repay  for  the  labour  on  the 
spoiled  ones. 

Tlie  writer  says  that  he  has  perhaps  been  needlessly  minute  in  the 
description  of  the  process  he  has  employed,  but  he  has  been  so  often 
hampered  by  the  lack  of  minuteness  in  descriptions  of  processes  by 
others,  vvliich  he  has  been  endeavouring  to  carry  out,  that  he  deems  it 
better  to  err  upon  the  safe  side,  even  at  the  risk  of  being  considered 
dry  or  prosy. 

A  no*e  is  added  as  to  the  uso  of  cosin.  He  was  attracted  to  it  by 
its  exquisite  purity  of  colour  under  transmitted  light,  and  its  perfect 
transparency.  Sections  preserved  iu  its  solution  were  found  always  to 
retain  their  transpai'eney,  and  did  ncjt  become  clogged  or  tliiek  with 
colour,  so  that  when  taken  out  after  months  of  innnersion  the  most 
dense  cells  were  no  deej)er  in  colour  than  the  solution  itself.  So  far 
as  regards  its  hold  upon  the  tissues,  it  is  as  strong  as  roseine,  or  any 
of  the  heavier  colours.  He  cannot  testify  as  to  its  permanence,  but 
has  some  slides  that  were  prepared  over  a  year  ago,  and  appear  to  bo 
as  bright  and  pure  as  when  they  were  mounted.  Contrary  to  tho 
experience  of  some  otliers,  he  has  not  found  that  tlie  benz«do  has  any 
bleacliing  effect,  and  it  has  b^en  used  with  dammar  in  preference  to  the 
usual  balsam.  Slides  prepared  with  dammur,  however,  should  have  a 
thick  ring  of  vaiiiish  run  around  them,  as  the  danim.ir  is  brittle,  and 
sliould  not  1)(;  trusted  ub^nt,'  to  Jk^M  tiic  covering  glass. 


696  RECORD   OF    CURRENT   RESEARCHES    RELATING    TO 

Wicker sheimer's  Preservative  Fluid  and  Vegetable  Objects.* — 
Dr.  K.  Prantl  describes  the  results  of  his  cxperiraeuts  with  this 
fluid,f  which,  though  so  valuable  for  animal  substances,  he  judged 
beforehand  would  not  be  applicable  to  parts  of  plants.  The  density 
of  the  fluid  removes  the  turgidity  of  the  cells  without  harden- 
ing the  protoplasm  quickly  ;  hence  the  delicate  parts  of  the  plant 
lose  their  firmness,  and  consequently  their  relative  jiosition,  even 
in  the  fluid.  The  flowers  of  Tropoiolum,  for  examjile,  collapsed 
after  being  a  few  hours  in  the  fluid,  and  became  unrecognizable. 
The  lamellae  in  the  pileus  of  different  Agnrici  were  greatly  distorted, 
not  only  after  being  taken  out  of  the  fluid,  but  whilst  still  in  it. 
Those  parts  of  a  plant  which  possess  sufiicient  consistency  alone 
preserve  their  shape,  as  Ferns  rich  in  sclerenchyma  {Blechnum 
australe),  and  the  leaves  of  Conifer^e,  objects  which  can  be  preserved  as 
well  dry.  If  pine  branches,  however,  arc  laid  in  the  fluid,  the  falling 
off  of  the  acicular  leaves  in  drying  is  prevented,  but  this  can  be  done 
just  as  well  by  concentrated  glycerine. 

Further,  the  fluid  kills  the  protoplasm,  hence  the  colouring 
matter  held  in  solution  by  the  cell-sap  comes  out  in  a  short  time. 
Chlorophyll  has  hitherto  been  retained,  but  changed  into  a  brownish 
tint. 

Hardening  Canada  Balsam  in  Microscopic  Preparations  by  Hot 
Steam.l — The  inconvenience  arising  from  the  slowness  with  whicli 
Canada  balsam  hardens,  especially  in  summer,  has  been  felt  by  all 
engaged  in  making  permanent  preparations.  M.  Passauer  describes 
a  small  and  simple  apparatus  which  he  made  for  the  purpose  of  over- 
coming this  objection.  It  consists  of  a  round  vessel  of  tin,  about 
18  cm.  in  diameter  and  6  cm.  deep,  with  a  tin  cover  19^  cm.  square 
(for  convenience  in  placing  the  slides),  to  the  under  surface  of  which 
a  circular  rim  about  1^  cm.  decji  is  sohlered  and  made  to  fit  easily 
into  the  vessel.  On  the  upper  side  the  cover  is  also  furnished  with  a 
rim  about  5  mm.  deep.  In  one  corner  of  the  lid,  but  inside  the  lower 
circular  rim,  a  tube  6  cm.  in  diameter  and  10  cm.  long  is  soldered 
and  passes  through  the  lid. 

In  using  it  the  vessel  is  half  filled  with  boiling  water,  covered 
with  the  lid,  and  the  prej^aration  to  be  hardened  laid  on  the  latter, 
and  the  temperature  of  the  water  kept  at  boiling-point  by  a  lamp 
placed  under  the  vessel.  Special  care  must  be  taken  that  the  steam 
does  not  become  too  hot,  otherwise  bubbles  would  be  produced  in  the 
balsam  and  the  prejjuration  be  spoilt,  hence  the  small  chimney  is 
provided,  through  which  part  of  the  steam  can  escape.  By  this  means 
the  balsam  can  be  hardened  in  1  to  1^  hours. 

Ringing  and  Finishing  Slides.§— The  following  article  by  Dr.  C. 
Seller  gives  some  useful  hints  :  — "  A  gi'cat  deal  may  be  said  in  favour 
of  and  against  the  careful  finishing  of  microscopical  slides,  but  nobody 
will  deny  that  a  nicely-ringed  preparation  looks  better  in  a  cabinet, 

*  '  Bot.  Centralbl.,'  i.  (1880)  p.  26.  t  Ante,  p,  325. 

t  '  Zeit.sclir.  f.  Mikr.,'  ii.  (1880)  p.  194. 
§  '  Am.  Jouin.  Micr.,'  v.  (1880)  p.  94. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  G97 

and  is  better  taken  care  of  by  its  owner  and  his  friends,  than  one 
which  is  not  thus  embellished,  and  which  shows  a  greater  or  less 
amount  of  balsam  irregularly  distributed  around  the  edge  of  the 
cover,  I  will,  therefore,  jot  down  a  few  remarks  on  the  ringing  and 
finishing  of  slides.  After  tlie  object  has  been  mounted  in  balsam 
and  the  cover  apjilied,  it  will  be  found  that  there  is  always  a  greater 
or  a  less  surplus  of  balsam  which  comes  out  from  under  the  cover. 
This  should  be  allowed  to  dry,  and  when  thoroughly  hard  it  can  be 
scraped  off  with  a  knife.  If  a  round  cover  has  been  used,  the  slide  is 
then  centered  on  a  turntable,  and  the  cover  cleaned  with  benzoic, 
which  is  best  done  by  dipping  a  soft  linen  rag  in  the  benzole  and 
applyiug  the  wet  place  with  the  forefinger  to  the  centre  of  the  cover- 
glass  ;  the  turntable  being  revolved,  the  finger  is  quickly  drawn 
toward  the  edge  of  the  cover  and  the  rag  removed.  One  or  two  such 
wipings  of  the  cover  will  be  found  sufficient  to  remove  all  traces  of 
balsam  or  extraneous  dirt.  The  slide  itself  may  then  be  wiped  also 
with  benzole,  and  it  is  then  ready  for  the  application  of  a  ring. 

The  best  ringing  medium  for  balsam  mounts  is  dammar  dis- 
solved in  chloroform,  because  if  it  is  inclined  to  run  under  the  cover 
it  will  readily  mix  with  the  mounting  material  without  leaving  a 
visible  trace  behind.  I  find  it  best  to  apply  the  brush  to  the  edge  of 
the  cover  almost  dry,  the  slide  on  the  turntable  sj)iuuing  rapidly 
around,  so  as  to  make  a  track  in  which  the  dammar  solution  will 
readily  flow.  The  second  application  is  to  be  made  immediately 
following  the  first,  with  the  brush  full,  so  that  there  will  be  a  small 
drop  of  solution  on  the  end,  which  is  allowed  to  touch  the  edge  of  the 
cover  without  letting  the  brush  itself  come  in  contact  with  the  glass. 
This  is  repeated  until  the  ring  is  bnilt  up  to  the  proper  size.  It 
should  be  borne  in  mind,  however,  that  in  drying,  the  ring  of  dammar 
will  shrink  considerably,  and  thus  it  is  necessary  to  make  another 
application  after  a  few  hours'  drying. 

Dammar  or  balsam  dissolved  in  benzole  or  benzine  is  objection- 
able, because  the  solution  will  evaporate  too  quickly  to  allow  of  a 
proper  building  up  of  the  ring,  and  if  such  is  attempted  the  re^^ult 
will  be  a  ring  full  of  minute  air-bubbles.  White  zinc  cement, 
Brunswick  black,  asphaltum  varuisli,  and  other  coloured  cements  may 
be  employed  to  cover  the  first  ring  of  dammar ;  but  they  should  never 
be  used  alone,  as  they  are  sure  to  run  in  sooner  or  later,  no  matter 
how  hard  tlie  balsam  may  be.  I  think  that  the  glass-like  ring 
obtained  with  dannuar  gives  a  better  appearance  to  the  slide  and  is 
more  durable  than  any  of  the  rings  made  with  coloured  cements. 

When  glycerine  mountings,  or  objects  mounted  in  a  watery 
medium  are  to  bo  ringed,  -it  is  necessary  to  first  get  entirely  rid  of 
any  glycerine  which  might  be  on  the  cover  or  slide.  To  do  this  I 
apply  a  spring  clip  to  the  slide,  which  serves  to  hold  the  cover  iu 
position  after  it  has  been  centered,  and  then  wasli  off  the  surplus 
glycerine  with  a  stream  of  water  from  a  syringe.  The  slide  is  then 
set  on  end  to  dry,  and  a  ring  of  a  waterproof  cement  is  applied  around 
the  cover.  Such  a  cement  may  be  bouglit  under  the  name  of  Bell's 
cement,  the  composition  of  wlnVli    is  a  t^ecrct.     A   bitter   and    less 


698  RECOBD   OF   CURRENT   RESEARCHES   RELATING   TO 

exj)ensive  cement  may,  however,  be  made  by  dissolving  10  grains  of 
gum-ammoniac  in  1  ounce  of  acetic  acid  (No.  8),  and  tben  by  adding 
to  this  solution  2  drachms  of  Cox's  gelatine.  The  resulting  liquid 
flows  easily  from  the  brush  and  is  waterproof,  especially  so  if,  after 
the  ring  has  set,  it  is  brushed  over  with  a  solution  of  10  grains  of 
bichromate  of  potash  in  1  ounce  of  water.  But  what  especially 
recommends  this  cement  is  its  great  adhesive  power  to  glass,  even  if 
there  should  be  a  little  glycerine  on  the  edge  of  the  cover.  After  the 
gelatine  ring  is  dry,  any  other  cement  may  be  employed  to  cover  it, 
according  to  the  fancy  of  the  preparer. 

When  a  considerable  number  of  different  objects  are  being  pre- 
pared at  the  same  time,  it  is  of  great  imjiortance  to  be  able  to  tell 
one  from  the  other,  so  as  finally  to  label  them  correctly  without 
subjecting  them  to  a  careful  microscopical  examination,  A  pajier 
label,  under  the  frequent  necessary  handling  of  the  slide,  becomes 
soiled,  and  the  writing  frequently  illegible ;  while  a  figure  or  even  a 
full  label,  written  with  a  pen  upon  the  glass  slide,  will  remain  intact 
throughout  the  manipulations  of  cleaning  and  ringing,  and  at  the 
same  time  can  easily  be  removed  by  a  little  rubbing  with  a  rag  dipped 
in  water. 

In  order  to  facilitate  the  finding  of  slides  in  a  large  collection, 
it  is  advisable  to  place  the  label  bearing  the  name  of  the  object 
always  on  the  same  end,  and  if  two  labels  are  used  to  place  the  one 
with  the  prejjarer's  name  on  the  right  hand,  and  the  other  bearing  the 
description  of  the  object  on  the  left." 

Cleaning  Cover-glasses.* — Dr.  E.  U.  Piper,  of  Chicago,  has 
suggested  a  very  simple  method  of  cleaning  cover-glasses  without 
breaking  them.  Upon  a  glass  plate  2x3  inches  are  cemented,  in 
the  form  of  a  V,  two  thin  strips  of  glass.  A  cover-glass  may  be  laid 
U2)on  the  glass  plate,  inside  of  the  V,  and  cleaned  by  rubbing  freely, 
being  held  in  position  from  slipping  by  the  sides  of  the  V. 

Preparing  Sections  of  Coal. — Mr.  E.  T.  Newton,  the  Assistant- 
Naturalist  of  the  Geological  Survey,  who  has  successfully  examined 
the  microscopical  structure  of  many  varieties  of  coal,  gives  f  the  follow- 
ing description  of  the  methods  employed  by  him  in  making  his 
preparations : — 

"  One  important  point  to  be  noticed  at  the  outset  is  that  nothing 
like  emery  powder  can  be  used  for  the  grinding,  as  the  grains  embed 
themselves  in  the  softer  substance  of  the  coal,  and,  when  the  section 
is  finished,  will  be  seen  as  minute  brip;ht  sj^ots,  thus  giving  to  the 
section  a  deceptive  appearance.  For  the  rough  grinding  an  ordinary 
grindstone  may  be  used,  and  for  the  finer  work  and  finishing  a  strij) 
of  '  pumice-stone  '  (or  corundum  stick),  and  a  German  hone  (or  Water- 
of-Ayr  stone).  The  form  of  these  which  has  been  fouud  most  con- 
venient is  a  strip  about  1^  inch  wide  and  about  G  inches  long ;  the 
thickness  is  immaterial :  one  of  the  broader  surfaces  of  these  must  be 
perfectly  flat. 

*  '  Ain.  Nut.,'  xlv.  (1880)  p.  465. 

t  F.  Rutlcy's  '  Study  of  Rocka '  (8vn,  LoJiduii,  187'J).  \\  71. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  699 

Having  selected  a  piece  of  coal  with  as  few  cracks  as  possible, 
cut  off  a  piece  with  a  saw  about  three-quarters  of  an  inch  square  and 
perhaps  one  quarter  of  an  inch  thick.  One  of  the  larger  surfaces  is 
then  rubbed  flat  on  the  pumice-stone,  keeping  it  well  wetted  with  water, 
and  then  polished  upon  the  hone,  also  moistened  with  water.  Some- 
times it  is  found  to  be  advantageous  to  soak  the  piece  of  coal  in  a  very 
thin  solution  of  Canada  balsam  in  chloroform  or  benzole,  as  directed 
for  softer  rocks,  or  in  a  solution  of  shellac  in  spirits  of  wine  ;  in  either 
case  allowing  the  specimen  to  dry  thoroughly  in  a  warm  place.  The 
polished  surface  is  next  cemented  to  an  ordinary  microscopical  glass 
slip  (3  inches  by  1  inch)  with  the  best  marine  glue ;  and  this  process 
requires  care,  for  it  is  not  easy  to  exclude  all  the  air-bubbles,  and  if 
they  are  not  excluded  the  section  is  very  apt  in  the  last  stages  to 
break  away  wherever  they  occur.  The  piece  of  coal  is  next  reduced 
to  about  one-sixteenth  of  an  inch  by  means  of  a  grindstone ;  some  of 
the  softer  kinds  may  be  cut  down  with  a  penknife.  Care  should  be 
taken  not  to  scratch  the  glass  in  the  process  of  grinding,  for  most 
sections  of  coal,  when  once  ground  thin,  are  too  fragile  to  allow  of  their 
being  removed  from  the  glass,  but  have  to  be  covered  and  finished  off 
upon  the  same  slide.  The  pumice-stone  or  corundum  stick  is  next 
brought  into  use.  The  section  being  turned  downwards,  hold  the 
glass  slide  between  the  middle  finger  and  thumb,  whilst  the  forefinger 
is  placed  upon  the  centre  of  the  slide.  In  this  manner  the  section  may 
be  rubbed  round  and  round  over  every  part  of  the  pumice,  using  plenty 
of  water,  until  it  is  sufficiently  reduced  in  thickness ;  experience  alone 
showing  how  far  this  process  may  be  carried.  The  section  is  finally 
rubbed  in  a  similar  manner  upon  the  hone  (or  Water-of-Ayr  stone).  It 
is  sometimes  found  necessary  to  use  the  hone  even  while  the  section  is 
absolutely  opaque,  for  many  coals  are  so  brittle  that  they  crumble  to 
pieces  upon  the  pumice  long  before  they  show  any  indications  of 
transparency.  "When  sufiiciently  transparent  the  section  may  bo 
trimmed  with  a  penknife  and  the  superfluous  marine  glue  cleaned  off. 

The  section  is  now  to  be  moistened  with  turpentine,  a  drop  of 
ordinary  Canada  balsam  (not  too  hard)  placed  upon  it,  and  covered  in 
the  usual  way.  Whatever  heat  is  necessary  should  be  carefully  applied 
to  the  cover-glass  by  reversing  the  slide  for  a  moment  or  so  over  a 
spirit  lamp,  otherwise  the  marine  glue  may  be  loosened  and  the  section 
spoiled.  Balsam  dissolved  in  benzoic  must  not  be  used  for  mounting, 
as  the  benzole  softens  the  marine  glue,  and  a  good  section  may  in  this 
way  be  destroyed." 

Cutting  Rock  Sections. — Mr.  Hanks  considers  it  a  mistake  to  cut 
a  rock  section  so  thin  as  to  be  wholly  transparent.  In  some  cases 
this  is  necessary;  but,  as- a  general  ruh',  the  section  should  be  hft  as 
thick  as  possible,  and  strongly  lighted  by  the  aid  of  a  parabolic 
reflector.  The  beauty  of  many  specimens  is  destroyed  in  tho  eflbrt 
made  to  fit  them  for  observation  by  simple  transmitted  light. 
Mr.  Attwood's  plan  *  to  cement  tlio  section  to  a  glass  slide,  and  to 
examine  it  from  time  to  time  under  the  Microscope  as  tho  work 
progresses,  is  very  important,  as  it  will  enable  the  student  to  stop  at 

•  Ante,  i>.  325. 


700  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

tlie  exact  j)oiut  wlien  light  can  be  passed  tbrougli  it,  but  before  many 
of  the  most  interesting  features  are  destroyed  by  over-cutting. 

Simple  Mechanical  Finger.* — The  devices  hitherto  employed  as 
"  Mechanical  Fingers "  depend,  Mr.  M.  A.  Veeder  writes,  upon  the 
lengthening  of  the  part  which  supports  the  substage  apparatus  by  means 
of  a  tube  specially  fitted  for  the  purpose,  or  by  means  of  the  para- 
boloid, so  that  by  a  rack  movement  the  slide  may  be  lifted  free  from 
the  stage  into  contact  with  a  hair  or  fine  wire,  which  is  held  by  the 
stage  forceps  or  by  some  contrivance  designed  especially  for  the 
purpose.  Contact  having  thus  been  established,  the  slide  may  be 
lowered,  leaving  the  object  adhering  to  the  hair,  or  by  moving  the 
sliding  stage  the  object  may  be  pushed  in  any  direction  desired. 
There  is,  however,  another  plan,  which  he  finds  to  be  simpler,  and 
even  more  effective  in  certain  respects.  With  many  Microscopes  a 
condensing  lens  is  supplied,  which  is  fitted  to  the  limb  of  the  instru- 
ment by  a  ball-and-socket  joint  and  sliding  stem-rod.  Unscrew  this 
lens  and  put  in  its  place  a  piece  of  cork  through  which  a  needle 
passes  at  a  right  angle  to  the  stem.  It  is  well  to  have  two  or  three 
pieces  of  cork  fitted  with  needles  having  difi'erent  points ;  one,  for 
instance,  may  have  a  human  hair  projecting  slightly  beyond  its  point, 
the  hair  being  kept  in  place  by  winding  with  fine  thread  and  coating 
with  gum ;  another  may  have  a  flat  point,  made  by  breaking  off  and 
grinding  the  fractured  end ;  other  forms  will  suggest  themselves 
as  experience  may  determine.  The  ball-and-socket  joint  should  be 
clamped  or  wedged,  so  as  to  move  quite  stifiiy.  Bring  the  point  of 
the  needle  into  view  under  the  objective,  and  it  may  be  made  to  touch 
the  slide,  or  be  lifted  away  from  it  by  simply  turning  the  stem-rod. 
Objects  which  are  seen  to  adhere  to  the  needle  are  lifted  at  once,  and 
another  slide,  slightly  moistened  by  breathing  on  it,  may  be  sub- 
stituted for  the  one  on  the  stage,  to  which  the  objects  may  be  made  to 
adhere  at  any  desired  point  by  turning  the  stem-rod  as  before.  By 
moving  the  mechanical  stage  while  the  point  of  the  needle  is  in 
contact  with  the  slide,  objects  may  be  pushed  wherever  desired  on 
the  slide.  In  this  case  it  is  a  decided  advantage  that  both  needle  and 
object  remain  within  view  however  the  stage  is  moved.  Thus  dirt 
may  be  scraped  away  with  the  greatest  ease. 

It  is  evident  that  such  a  contrivance,  consisting  essentially  of  a 
ball-and-socket  joint,  and  a  sliding  stem  with  a  button  attached  to  the 
latter,  so  that  it  may  be  readily  turned,  might  be  fitted  to  the  stand  of 
an  ordinary  bull's-eye  condenser,  and  thus  become  available  for  use 
with  any  microscope-stand. 

Slides  from  the  Naples  Zoological  Station. — At  the  June  meet- 
ing of  the  Society  some  slides  were  exhibited  (for  the  most  part 
illustrating  the  early  stages  of  Invertebrates  t),  sent  by  the  Zoological 
Station  at  Naples  through  Mr.  A.  W.  Waters.  Microscopists  will  be 
glad  to  hear  that  the  Station  have  commenced  a  department  under  the 
management  of  Mr.  Fritz  Meyer  for  the  preparation  of  microscopical 
objects  on  a  large  scale,  a  list  of  which  they  intend  shortly  to  issue. 

*  'Am.  M.  Micr.  Jouru.,'  i.  (1880)  p.  88.  t  See  Uat,  iwst,  p.  736. 


INVEKTEBEATA,   CRTPTOGAMIA,    MICROSCOPY,    ETC.  701 

If  the  slides  are  generally  of  the  character  of  those  exhibited  the 
supi)ly  must,  we  are  afraid,  for  some  time  fall  short  of  the  demand,  as 
there  will  be  few  biologists  who  will  not  desire  to  add  some  of  the 
slides  to  their  cabinet. 

Homogeneous-Immersion  Lenses.* — Mr.  A.  A.  Biagdon,  referring 
to  the  strong  impression  prevalent  among  microscoj^ists  that  objectives 
having  high  interior  angles,  say  90°  and  upwards,  are  of  no  use 
except  to  amuse  diatomists,  says  that  this  is  by  no  means  the  true 
state  of  the  case.  On  comparing  the  definition  obtained  with  a  water- 
immersion  objective  of  105°  interior  angle  (by  Tolles)  with  other 
lenses  having  120°  or  140°  air  angle,  the  image  with  the  latter  was 
shown  to  be  imsatisfactory.  And  again  on  comparing  the  water- 
immersion  with  the  same  maker's  recent  homogeneous-immersion 
having  127°  interior  angle,  the  advantage  was  decidedly  with  the 
latter.  He  refers  to  the  series  of  microphotographs  by  Dr.  J.  J. 
Woodward  f  of  A.  pellucida  mounted  in  balsam,  with  Zeiss's  ^^^  and  \ 
oil-immersions,  together  with  other  notable  objectives  for  comparison 
of  their  respective  merits.  Among  these  lenses  were  a  i  and  -^jj  inch 
by  Spencer,  glycerine-immersion,  and  a  -jig -inch  oil-immersion  by 
Tolles,  and  says  that  "  it  is  only  necessary  for  any  unprejudiced 
person  to  examine  this  series  of  photographs  to  decide  at  once  as  to 
the  superiority  of  the  homogeneous-immersion  lenses  in  defining 
power." 

Mr.  Bragdon  approves  of  Mr.  Tolles  retaining  the  screw-collar 
with  homogeneous-immersion  lenses  for  these  reasons, — that  it  affords 
a  means  of  using  water  as  an  immersion  medium  when  several 
preparations  are  being  mounted  of  one  kind,  and  it  is  desired  to  make 
a  cursory  examination  of  them  at  once  with  high  powers  before  any 
change  shall  have  taken  place,  and  without  waiting  for  covers  to 
become  fixed  by  hardening  of  the  balsam ;  the  collar-adjustment  is 
also  useful,  even  with  the  homogeneous-immersion,  to  obtain  the  best 
image  with  diifercnt  lengths  of  draw-tube. 

Fluid  for  Homogeneous  Immersion.  J — Mr.  Bragdon  finds  that  the 
best  medium  for  homogeneous  immersion  is  glycerine  brought  up  to 
the  required  index  by  making  a  saturated  solution  witli  it  and  sulj)ho- 
carbolatc  of  zinc :  there  is  only  one,  and  that  not  a  serious,  objection 
to  its  every-day  use,  viz.  that  it  is  just  a  little  too  thick. 

Dr.  Blackham  also  says  §  that,  "  good  heavy  glycerine  is  the  best 
immersion  medium  he  has  found  out  of  many ;  it  docs  not  evaporate, 
soften  cement  used  in  mounting  objects,  nor  smell  badly,  is  not 
poisonous  nor  irritant,  and  is  in  every  way  satisfactory." 

Errors  of  Refraction  in  the  Eyes  of  Microscopistsll— Dr.  J.  C. 
IVIorgan  points  out  tliat  the  requirements  in  construction  and  adjust- 
ment of  glasses  and  the  results  of  work  done  must  vary  greatly  with 

*  '  Am.  M.  Micr.  Journ.,'  i.  (1880)  pp.  89-93. 
t  Poo  this  .Tournnl,  ii.  (IHTK)  p.  C,~2. 
X  'Am.  M.  l\Iicr.  Jotirii.,'  i.  (ISSO)  p.  92. 
§  '  Eu<i\.  Mooh..'  xxxi.  (IS.SO)  p.  100. 
il  'Am.  Juurii.  Micr.,'  v.  (IS^O)  p.  91. 


702 


RECOED   OF   CURRENT   RESEARCHES  RELATING   TO 


individualities  of  the  workers'  eyes,  of  wliich  one  of  the  most  important, 
but  least  thought  of,  is  astigmatism.  Owing  to  this  defect,  the^  later 
pictures  of  Turner  are  found  to  be  distorted,  the  tendency  being  to 
exaggerate  the  size  of  the  paler  dimension  in  painting  it.  On  the 
contrary,  in  microscopical  drawing  (as  with  the  camera  lucida)  the 
improperly  pale  line  will  be  perpetuated  and  the  perspective  mis- 
represented. Distortion  of  dimensions  generally  may  be  perpetrated 
by  the  most  careful  observers,  and  endless  disputes  may  thus  arise. 
A  familiar  example  of  this  is  shown  in  the  case  of  the  Podura  scale. 

Micrometre  or  Micromillimetre.* — Dr.  Phin  points  out  that 
"  micrometre  "  is  inadmissible  in  America  at  least,  as  it  would  there 
be  spelt  "  micrometer,"  and  confounded  with  the  instrument  of  that 
name,  a  difficulty  which  the  difference  in  pronunciation  would  not 
remedy.  He  thinks,  therefore,  that  the  proper  way  is  to  "  fall  into 
line  "  with  the  British  Association  Committee,  and  adopt  the  nomen- 
clature suggested  by  Mr.  Stoney,  calling  the  thousandth  of  a  milli- 
metre (or  the  millionth  of  a  metre)  a  — -,  or  sixth-metre — the  prefix 

sixth  here  indicating  the  negative  exponent  of  10  by  which  the  metre 
is  to  be  multiplied. 

Micrometry  and  CoUar-adjustment.t — Dr.  Beale,  in  his  '  How  to 
Work  with  the  Microscope,'  recommends  that  scales  be  drawn  or 
printed,  showing  the  size  to  which  hundredths  or  thousandths  of  the 
inch  or  centimetre  are  magnified  by  each  of  the  objectives  used,  and 
one  of  these  scales  corresponding  to  the  objective  employed,  pasted  on 
every  drawing.  A  writer  in  the  '  American  Monthly  Microscopical 
Journal '  recalls  the  fact  that  in  all  objectives  made  with  a  collar- 
adjustment,  the  magnification  at  the  "  open "  and  "  closed  "  points 
varies  so  much,  that  attention  to  this  is  necessary  in  making  the  scales 
as  suggested.  Whilst  the  fact  is  well  known,  the  amount  of  the 
difference  does  not  seem  to  have  been  sufficiently  taken  into  account. 
This  will  be  best  illustrated  by  a  table  showing  the  variations  in  a 
few  objectives  of  well-known  makers,  taken  with  a  tube  10  inches  in 
length,  measured  from  the  stage-micrometer  to  the  end  of  the  tnbe 
proper  (not  to  the  end  of  the  eye-piece)  : — 


Oculars. 

Objective. 

A. 

B. 

C. 

Geo.  Wale,  i  inch,  open       

„            „         closed 

Powell  and  Lealand,  ^  inch,  open     .. 

„            „                M         closed   .. 
Spencer  and  Sons, -Jg  inch,  open 

„          closed      .. 
Wm.  Wales,' iV  inch,  open 

„              '„         closed 

262 
283 
.S92 
600 
462 
633 
617 
733 

433 
406 
650 
833 
750 
887 
850 
1200 

680 
725 
1025 
1300 
1200 
1400 
1350 
1900 

'  Am.  Jon  in.  Micr.,'  p.  117. 
Am  M.  Micr.  .loiim.,'  i.  (1880)  p.  67. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  703 

It  will  bo  seen  that  the  range  in  magnification  is  greater  with  some 
lenses  than  with  others,  the  dilfcrence  increasing  with  the  increase  of 
power,  but  with  all  it  is  so  great,  that  scales  made  without  taking  it 
into  account  would  be  worse  than  useless.  Accuracy  can  only  be 
obtained  by  using  the  micrometer  with  the  collar-adjustment  at  the 
same  point  at  which  the  object  sketched  has  been  examined,  unless, 
indeed,  one  were  willing  to  take  the  trouble  of  compiling  a  table  for 
each  objective,  with  the  magnification  noted  for  each  division  of  the 
collar  through  the  whole  range  from  "  uncovered  "  to  "  covered." 

Zeiss's  Microspectroscope. — This  instrument,  shown  in  Fig.  55 
(half  natural  size),  has,  in  addition  to  a  comparison-prism  and  arrange- 
ment for  reducing  the  length  of  the  spectrum,  a  micrometer  by  which 
the  position  of  bright  or  dark  lines  in  the  spectrum  is  determined  by 
a  direct  reading  of  their  -wave-lengths.  For  this  purpose  a  micrometer 
scale  is  projected  on  the  spectrum  by  reflection,  by  the  divisions  on 
which  the  wave-lengths  at  every  part  of  the  spectrum  (according  to 
Angstrom)  can  be  directly  read  off  in  parts  of  a  micromillimetre. 
The  divisions  on  the  scale  read  to  the  second  decimal  place ;  and  the 
third  decimal  may  be  easily  estimated  by  the  eye.  For  convenience 
of  recording  observations  there  are  lithographed  sheets  with  ten 
scales  of  wave-lengths  enlarged  to  lOQ  mm. 

Fig.  55. 


A  is  a  shallow  drum  between  the  field-  and  cyc-glasses  of  an 
achromatic  eye-piece,  and  contains  the  'SGravesande  slits,  comparieon- 
prisni,  &c. 

B  is  a  cylindrical  tube  over  the  oye-piecc,  and  contains  the  Amici 
prism.  It  carries  the  lateral  tube  C,  which  has  a  small  adiromatio 
objective  at  o  at  the  focus  of  which  at  i  is  the  micrometer  scale.  B 
turns  on  the  pivot  m  and  is  hold  in  the  axis  of  the  cyc-piccc  by  a 
catch  e ;  by  pressing  this  catch,  B  with  all  the  parts  attached  to  it 
may  be  turned  about  the  pin  m,  so  that  the  eye-piece  is  free. 


704  RECORD   OF    CURRENT    RESEARCHES   RELATING    TO 

D  is  a  stage  with  spring  clips  for  fixing  the  preparation  whose 
gpectrum  is  to  be  compared.  The  comparison-prism  is  brought  up 
before  one  half  of  the  slit  by  the  lever  p.  The  screw  /  regulates  the 
width  and  g  the  length  of  the  slit ;  when  the  latter  is  opened  as  wide 
as  possible,  the  central  portion  of  the  field  is  free  ;  so  that  the  upper 
part  (B  C)  being  turned  back,  the  Microscope  may  be  used  in  the 
ordinary  way.  The  screw  h  (underneath  the  tube  C)  serves  to  adjust 
the  scale.  This  is  to  be  fixed  before  commencing,  so  that  the  Fraun- 
hofer  line  D  coincides  with  0 "  589.  The  parallelism  of  the  scale  with 
the  spectrum  is  secured  by  turning  its  frame  i.  The  mirror  h  throws 
light  on  the  comparison-prism,  and  I  on  the  scale. 

The  microspectroscope  is  inserted  in  the  tube  of  the  Microscope 
like  an  ordinary  eye-piece,  and  is  fixed  in  the  required  position  by  an 
attachment  screw  beneath  A.  When  the  object  to  be  examined  is  of 
considerable  dimensions,  no  objective  need  as  a  rule  be  used  on  the 
tube,  otherwise  as  low  a  one  as  possible.  As  a  variation  in  the  dis- 
tance between  the  scale  and  the  lens  o  would  alter  the  value  of  the 
divisions  of  the  scale,  very  short-sighted  or  long-sighted  observers 
must  use  proper  spectacles  (or  have  a  spectacle  lens  placed  on  B)  to 
produce  a  medium  distance  of  vision  in  order  to  see  the  lines  and 
numbers  on  the  scale  with  perfect  sharpness  of  definition.  For  exact 
focal  adjustment  of  the  spectrum,  the  eye-glass  is  movable  beneath  the 
collar  B.  It  must  be  so  fixed  that  the  Fraunhofer  lines  in  the  spec- 
trum of  daylight  plainly  appear  along  with  the  scale,  and  on  moving 
the  eye  there  should  be  no  ajipearance  of  parallactic  displacement 
towards  the  division  lines. 

Ross's  Improved  Microscope  (Plate  XVI.). — Since  this  instru- 
ment was  first  exhibited  to  the  Society  *  several  improvements  have 
been  made  in  the  details  of  the  construction  by  which  the  stand  is 
rendered  more  serviceable  as  a  practical  working  instrument. 

The  vertical  pillar  supports  have  been  adopted  for  the  main  limb, 
an  alteration  which  permits  the  free  use  of  the  swinging  substage 
with  the  Microscope  in  a  vertical  position,  a  point  of  special  importance 
for  work  with  fluid  preparations. 

For  central  light  the  substage  can  now  be  clamped  in  the  optic 
axis,  and  the  illumination  exactly  centered  by  means  of  the  usual 
centering  screws. 

For  convenience  in  using  low  powers — when  the  substage  con- 
denser may  be  dispensed  with — the  substage  itself  may  be  entirely 
removed,  the  mirror  alone  then  serving  as  illuminator ;  for  this 
purpose  the  focus  of  the  mirror  has  been  shortened,  and  means  have 
been  provided  for  more  readily  adjusting  it  to  any  required  position. 

The  mechanical  stage,  with  rotatory  motion  in  azimuth  and  the 
facility  of  being  inverted,  has  been  considerably  altered  by  the  intro- 
duction of  phosj)hor-bronze  metal'in  the  parts  liable  to  flexure,  and  the 
stage  has  been  rendered  one  of  the  most  rigid  and  at  the  same  time 
thinnest  yet  made.  The  modifications  in  the  construction  of  the 
stage,  though  making  but  little  change  in  its  general  appearance,  are 
specially  imjiortant  in  detail. 

*  See  this  Jouriiiil,  i.  (1S7S)  pp.  1G3  and  197. 


JOURN.  R.  MICE.  SOC.  VOL.  III.  PL.  XVJ. 


Ross's  Improved  Microscope. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


705 


The  slow-motion  focussing  adjustment  has  been  remodelled  so  that 
the  focussing  is  extremely  sensitive  and  yet  free  from  all  rocking 
motion,  and  the  bearings  of  the  rack  and  pinion  movements  have  been 
increased  in  size,  and  a  greater  smoothness  of  motion  obtained. 

The  iris  diaphragm  can  be  used  either  attached  to  the  achromatic 
condenser  or  placed  in  the  stage  itself  immediately  beneath  the 
object  and  almost  on  a  level  with  the  upper  plane  of  the  stage,  so  as 
to  give  every  facility  for  regulating  the  amount  of  light. 

Professor  Huxley's  Dissecting  Microscope. — This  instrument 
(Fig.  56),  made  by  Messrs.  Parkes  and  Son,  of  Birmingham,  was 
arranged  by  Professor  Huxley,  and  was  shown  by  him  during  his 
term  of  oflfice  as  President  of  the  Quekett  Microscopical  Club.  It  is 
designed  specially  for  use  either  as  a  simple  or  a  compound  Micro- 
scope, and  arranged  with  regard  to  portability  for  travelling. 

Fig.  .56. 


The  stage— which  is  furnished  with  rotating  diaphragm,  and  arm 
for  carrying  a  condenser — consists  of  a  circular  disk  of  black  plate 
glass,  with  a  large  central  aperture,  and  is  mounted  on  a  brass  tripod 
stand  strong  enough  t(j  bear  considerable  pressure.  The  arm,  carrying 
the  powers  and  compound  body.  Las  a  coarse  rack  movement,  and  fine 
screw  arljustmcnt,  and  can  be  turned  aside  if  required. 

On  Professor  Huxley's  suggestion,  that  tlic  old  plan  of  snnrijKf  on 
VOL.    III.  3    A 


706  EECOED    OF    CURKENT    RESEARCHES   RELATING   TO 

the  objectives  and  compound  body  should  be  abolished,  a  new  and 
more  expeditious  method  has  been  adopted.  Instead  of  screwing  the 
body  on  to  the  arm,  and  then  screwing  the  objective  into  the  body, 
the  objectives  are  made  to  slide  down  smoothly  into  the  arm  (as 
illustrated  in  the  iigure),  and  may  thus  be  used  as  simple  powers,  for 
dissection.  When  the  compound  body  is  required,  it  may  be  in- 
stantaneously slid  over  the  objective,  and  is  thus  ready  for  use,  with 
a  great  saving  of  time  and  trouble. 

Should  it  be  desirable  at  any  time  to  use  objectives  having  the 
Society  screw,  provision  is  made  for  so  doing,  by  the  lower  end  of  the 
tube  which  passes  through  the  arm  being  cut  with  such  a  screw.  A 
loose  adapter  having  the  standard  screw  is  also  supj^lied  with  each 
instrument,  which  will  receive  the  objectives  belonging  to  it ;  by 
screwing  them  into  the  adapter  they  may  be  used  with  another 
Microscope  if  necessary. 

The  following  is  the  (verbal)  description  which  Professor  Huxley 
gave  of  the  instrument  :* — 

"  In  a  Microscope  to  be  used  for  delicate  dissections,  certain  quali- 
fications were  absolutely  essential.  In  the  first  place,  there  must  be 
perfect  steadiness,  the  stand  must  be  firmly  and  well  supported,  and 
be  of  sufiicient  strength  and  weight  to  bear  the  pressure  put  upon  it 
without  moving.  Next,  it  must  be  of  convenient  height,  so  that  in 
working  the  hands  may  get  a  steady  suj)port ;  it  should  fulfil  these 
two  conditions,  and  yet  not  be  so  large  as  to  be  clumsy.  The  next 
point  was  as  to  the  lenses  :  they  should  be  of  such  a  form  as  to  give  a 
maximum  of  power,  and  yet  at  the  same  time  afford  sufficient  distance 
between  them  and  the  object  to  admit  of  needles  being  moved  freely 
to  an  angle  of  60''  with  the  surface  of  the  plate,  because  the  efficiency 
of  the  needles  obviously  depended  upon  the  angle  at  which  they  could 
be  used,  and  if  a  lens  were  made  with  a  wide  face  it  would  very  often 
interfere  with  the  movements  of  the  needles.  Then  there  was  another 
point  of  still  greater  importance :  when  a  careful  dissection  had  been 
made,  it  often  became  desirable  to  examine  it  with  a  much  higher  power 
than  the  one  which  had  served  the  purpose  of  preparation,  and  provision 
ought  to  be  made  to  enable  as  high  a  power  as  was  desired  to  be 
brought  to  bear  without  disturbing  the  object,  and  this  could  only  be 
done  by  placing  a  compound  body  above  the  simple  lens. 

[The  President  then  exhibited  the  instrument  which  he  had  devised 
to  meet  these  requirements  as  described  above.] 

"  In  offering  the  instrument  for  discussion,  the  question  would  arise 
as  to  the  best  form  of  lens  to  be  employed,  and  he  hoped  to  receive  the 
opinions  of  the  members  upon  this  and  other  matters  ;  but  at  present  he 
used  an  ordinary  low-power  achromatic  objective,  made  so  as  to  slip  into 
the  arm  without  screwing;  there  was  great  convenience  in  thus  mounting 
and  using  a  simple  lens.  .  .  .  Now,  supposing  they  had  made  their  dis- 
section successfully,  the  point  was  how  to  be  able  to  convert  the  instru- 
ment at  once  into  a  compound  Microscope  without  disturbing  either  the 
lens  or  the  object.  One  of  his  aims  in  life  had  been  to  get  Microscope- 
makers  to  abolish  screws,  which  he  regarded  altogether  as  abominable 
*  '  Jomu.  Quek.  Micr.  Club,'  v.  (1879)  p.  144. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  707 

inventions  ;  and  in  this  instance  the  compound  body  had  been  made  to 
slip  over  the  outside  of  the  socket  in  which  the  objective  had  been 
placed.  This  plan  answered  fairly  well,  but  he  thought  it  would  be 
better  to  have  it  made  to  fit  rather  more  easily,  and  to  be  secured  by 
a  bayonet  joint,  because,  supposing  that  the  power  employed  was  not 
Eufficieut  for  the  purpose,  then  inconvenience  arose  unless  the  body 
could  be  got  off  again  with  sufficient  ease  to  ensure  the  object  remain- 
ing undisturbed  by  any  jerk  or  movement.  With  the  improvement  of 
the  bayonet  joint  it  would  be  easy  to  remove  the  body,  and  having 
taken  out  the  first  lens,  and  di'opped  in  say  a  ^-inch,  the  body  would  go 
on  again  without  any  disturbance.  He  had  the  instrument  before  them 
made  upon  that  pattern,  to  see  how  the  thing  would  work  ;  he  had  used 
it  for  the  past  six  or  eight  months  incessantly,  and  he  could  certainly 
say  that  for  his  requirements  it  was  the  best  thing  he  had  seen,  and  he 
believed  that  with  the  little  addition  of  a  bayonet  joint  it  would  be  as 
nearly  perfect  as  any  instrument  of  the  kind  could  well  be.  He 
thought  that  all  persons  who  had  been  occupied  in  making  minute 
dissections  would  see  that  it  had  value,  and  met  all  the  requirements  of 
the  most  delicate  work.  He  hoped  that  the  members  would  examine 
and  criticize  it,  and  make  any  suggestions  that  occtured  to  them  for 
its  further  improvement,  for  it  was  becoming  of  very  great  importance 
to  examine  thin  sections  and  minute  portions  of  dissections  without 
subjecting  them  to  any  such  disturbance  as  to  cause  the  slightest 
alteration,  and  it  was  equally  important  to  be  able  to  bring  to  bear  upon 
them  under  such  conditions  the  highest  powei's  that  might  be  needed." 

Nachet's  Chemical  Microscope.* — In  this  Microscope  (shown  in 
Fig.  57)  the  objective  is  placed  beneath  the  object  on  a  brass  box 
containing  a  mirror  silvered  on  its  upper  surface.  To  this  box  is 
screwed  the  body  containing  the  eye-jjiece  and  a  sliding  tube  which 
is  used  as  a  coarse  adjustment.  The  silvered  surface  of  the  mirror 
is  entirely  protected  from  the  action  of  the  air,  as  the  two  oi)enincrs 
of  the  box  are  furnished  with  jiarallel  glass  plates.  The  focal  ad- 
justment is  made  by  raising  the  objective  and  by  the  micrometric 
screw  V  which  moves  the  stage.  On  the  latter  is  a  circular  glass 
cell  C,  the  bottom  of  which  is  pierced  with  a  hole  of  18  mm.,  closed 
by  thin  cover-glass  well  luted  with  Caaada  balsam  or  with  silicate 
of  potasli.  The  object  to  be  examined  is  placed  on  the  thin  glass. 
An  arm  B  carries  a  mirror  which  reflects  light  from  above  upon  the 
object  in  the  cell.  The  latter  is  provided  with  two  glass  taps  R  R', 
and  is  covered  by  a  disk  of  plane  glass  hermetically  sealed  by  a  little 
glycerine  or  grease  placed  around  the  edge  of  the  cell.  Three  small 
brass  uprights  keep  the  coll  and  its  cover  in  place  and  immovable. 
The  instrument  has  a  new  arrangement  for  seeing  the  diflereut  parts 
of  the  preparation.  The  body,  and  consequently  tlie  objective,  is 
moved  by  means  of  two  transverse  screws  O  and  T.  The  plate  which 
supports  the  box  is  furnished  with  two  transverse  divisions  in  con- 
nection with  the  movement  of  the  screws,  so  as  to  have  in  eflect  a 
finder  (the  divisions  aro  not  represented  in  the  figure). 

*  Tmnslated  (with  8lip;lit  nltorntinns)  from  note  furnislied  by  M.  Naohet. 

3  A  2 


708 


RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 


If  one  reflects,  M.  Nacliet  says,  on  the  necessity  of  attaching  india- 
rubber  tubes  to  tlie  glass  taps,  and  f)f  being  assured  of  the  perfect 
immobility  of  certain  anatomical  elements,  the  advantages  of  the 
above  arrangement  will  be  at  once  understood.  Experiments  on  the 
absorption  of  gas  and  on  the  rarefaction  and  compression  of  air  could 
not  be  more  simple.  The  apparatus  gives  at  the  same  time  a  moist, 
a  warm,  and  a  gas  chamber,  and  moreover  the  highest  powers  can  be 
employed  without  any  inconvenience.  The  necessary  humidity  re- 
quired for  the  object  is  maintained  by  means  of  wetted  blotting-paper, 
&c.,  placed  in  the  cell  C. 

Fio.  :7 


Two  parts,  as  will  be  seen,  are  essential  in  this  instrument — first, 
the  moist  chamber ;  and  secondly,  the  arrangement  of  the  instrument 
itself.  As  regards  the  latter,  it  is  very  similar  to  those  of  Dr.  J.  L. 
Smith  and  Dr.  Leeson,*  and  the  one  hitherto  made  by  M.  Nachet ;  but 
there  is  this  capital  distinction,  that  the  optical  ajiparatus  in  the  new 
instrument  is  movable  in  all  directions,  and  that  the  object  remains 
immovable  upon  the  stage. 

More  recently  M.  Nachet  has  replaced  the  cell  above  described  by 
smaller  cells  of  the  same  kind  attached  to  brass  plates  ai'ranged  so 

*  See  Dr.  W.  B.  Carpenter's  '  The  Microscope  and  its  Eevelatious,'  5tli  ed., 
1875,  p.  108. 


INVERTEBRATA,   ORYPTOGAMIA,   MICROSCOPY,   ETC.  700 

as  to  always  liave  a  fixed  position  ou  the  stage.  By  mcaus  of  the  two 
transverse  divisions  of  tlie  plate  carrying  tlie  optic  ajiparatus,  any 
point  of  the  liquid  under  examination  can  be  immediately  refouud. 
This  is  very  important  in  researches  on  the  culture  of  ferments,  which 
are  often  under  observation  for  several  days,  and  are  continually 
being  modified.  The  form  of  the  cell  rcijresented  in  the  figure 
renders  the  Microscope  inconvenient  for  many  consecutive  observa- 
tions ;  the  new  plan  allows  the  systems  of  culture  to  be  multiplied  in- 
definitelj',  so  as  to  enable  the  necessary  verifications  on  any  desired 
point  to  be  made  daily.  It  is  only  necessary  to  take  precautions 
when  the  cell  is  detached  from  the  stage. 

Tiffany's  Prepuce  Microscope-  —  Several  arrangements  have 
hitherto  been  devised  fur  showing  the  circulation  of  the  blood  in  the 
human  subject,  so  as  to  obtain  assistance  in  the  diagnosis  of  disease, 
amongst  which  are  the  "  Fra)num  Microscope  "  of  Dr.  Urban  Prit- 
cbard,*  and  the  apparatus  devised  by  Dr.  C.  Hueter  for  examining 
the  lower  lip,  which  we  recently  described  under  the  title  of 
"  Cheilo-angioscopy."  f 

Dr.  Tifiany,  of  Kansas,  U.S.A.,  suggests  +  the  prepuce  as  the  most 
suitable  part  for  the  examination  of  the  circulation.  On  account  of 
its  thinness,  high  powers  with  transmitted  liglit  are  available  for 
the  examination.  To  hold  the  prepuce  in  such  a  position  as  to  render 
the  examination  very  satisfactory,  he  uses  a  thin  piece  of  celluloid, 
wood,  or  other  light  substance,  with  clamps  projecting  from  tlie  under 
side,  which  fasten  on  each  side  of  the  lower  half  of  the  prejnice,  and 
by  thumbscrews  at  the  free  end  of  the  instrument  render  it  tense 
both  laterally  and  longitudinally.  Near  the  attached  end  of  the  in- 
strument is  a  circular  opening,  ^  inch  in  diameter,  under  which  is 
fastened  a  thin  cover-glass,  so  that  the  mucoiis  membrane  of  the  lower 
half  of  the  prepuce  lies  in  contact  w^ith  this  cover-glass.  In  this 
position,  with  the  prepuce  spread  out  nearly  as  thin  as  the  web  of  a 
frog's  foot,  it  is  clamped  upon  the  stage  of  the  Microsc()i)e,  and  by 
transmitted  light  can  be  examined  by  tlie  highest  powers.  A  vessel 
should  be  selected  which  is  immediately  beneath  the  mucous  mem- 
brane, and  it  should  be  pressed  (^uite  firmly  against  the  cover-glass. 
Two  woodcuts  are  given,  showing  the  proper  manner  of  applying  the 
clamp  and  conducting  the  examination. 

Dr.  Tiftany  has  examined  several  patients,  but  "  having  no  status 
as  a  guide,  has  scarcely  been  able  to  determine  whether  what  was 
seen  was  normal  or  abnormal."  He  is,  however,  satisfied  that  this 
method  will  i)rovo  a  valuable  means  of  making  and  confirming  diag- 
nosis of  constitutional  diseases,  as  well  as  a  means  of  watching  the 
progress  and  effects  of  therapeutical  agents. 

Tolles-Blackham  Microscope-stand. — Eeferriug  to  tlie  descrip- 
tion of  this  stand  at  p.  Ti'JO,  Dr.  iJlackhum  writes  that  the  snbstage  arm 
is  not  moved  circularly  by  the  milled  head  B  ;  it  slides  freely  but 

*  Sec  Dr.  Heiilo'a  '  The  Mi(.Tosco|io  in  Medicine,'  Itli  cd.  (1S7)>)  p.  503. 
t  See  tliirf  .lunniul,  ii.  (187;»)  p.  lUO. 

X  'St.  lionii  IMfil.  iin(l  Surj;.  Joinii.,'  xxxviii.  (1880)  pp.  ,^87-'J.  Sec  olau 
'  Loiiiavillc  Med.  Her.,'  ii.  (18H0)  p.  :tO. 


710  RECORD   OF   CURRENT   RESEARCHES   RELATING    TO 

firmly  by  hand,  B  being  merely  a  clamping-screw  to  hold  the  substage 
apparatus  in  position,  and  is  but  seldom  needed,  though  of  great 
importance  under  certain  conditions. 

Weber-Liel's  Ear-Microscope.* — The  following  is  the  description 
given  of  this  instrument  in  the  '  Berlin  Microscopical  Journal ': — 

To  the  many  and  varied  adaptations  of  the  Microscope  an  addition 
has  lately  been  made,  the  possibility  of  which  was  formerly  thought  to 
be  extremely  doubtful,  viz.  the  inspection  of  internal  parts  of  the 
human  body  which  are  difficult  of  access.  Although  such  parts,  as  the 
oral  cavity  and  auditory  passage,  have  previously  been  examined  by 
means  of  a  lens  and  illuminating  mirror,  the  low  magnifying  power 
of  the  apparatus  set  narrow  limits  to  the  examination.  Now,  however, 
the  instrument  of  Dr.  Weber-Liel  has  made  it  possible,  afc  least  for 
the  ear,  to  detect  the  finer  abnormalities  of  structure  and  in  many  cases 
to  discover  and  remove  the  cause  of  disease. 

The  Microscope,  which  is  shown  in  Fig.  58,  consists  of  three  prin- 
cipal parts : — 

(1)  The  Microscope  proper. 

(2)  The  mirror  with  illuminating  lens. 

(3)  The  pneumatic  chamber  and  flexible  tube. 

The  body  of  the  Microscope  Tj  has  a  conical  piece  0  attached  to 
its  lower  extremity,  several  of  which  of  different  sizes  are  supplied 
with  each  instrument  so  that  one  may  be  screwed  on  which  is  adapted 
for  the  particular  case  and  will  entirely  fill  up  the  auditory  passage. 
Above  this  is  a  chamber  into  the  side  of  which  an  indiarubber  tube 
opens,  having  a  mouth-piece  at  its  other  extremity ;  this  chamber  is 
closed  at  the  upper  part  by  the  mirror  K  which  fits  air-tight  so  that 
when  the  instrument  is  introduced  into  the  ear  no  air  has  access  except 
through  the  tube.  The  Microscope  T^  with  the  eye-piece  T  slides 
into  the  txibe  T2,  the  eye-piece  having  a  micrometer  at  m.  The 
mirror  which  closes  the  pneumatic  chamber  is  inclined  at  an  angle 
of  45°  to  the  axis  of  the  tube,  with  its  reflecting  surface  turned 
towards  the  illuminating  lens  G.  The  reflecting  surface  has  its 
coating  removed  in  the  centre  so  that  a  clear  view  down  the  axis  of 
the  Microscope  is  obtained  through  it.  The  magnifying  power  of 
the  instrument  is  about  twenty  diameters,  which  is  strong  enough  for 
viewing  the  small  parts  of  the  ear,  as  the  malleus,  stapes,  &c. 

Besides  the  parts  above  figui*ed  and  described,  there  should  be  also 
the  ordinary  speculum  and  two  lenses.  One  of  these  lenses,  magni- 
fying about  five  diameters,  is  fixed  in  a  short  tube  and  inserted  at  Tg 
for  making  a  preliminary  examination  and  (what  only  could  hitherto 
be  done)  seeing  the  position  of  the  parts.  The  second  lens,  which 
magnifies  about  three  diameters,  is  used  in  making  the  operations.  To 
give  room  for  the  instruments  in  the  latter  case,  the  cone  0  is  rejjlaced 
by  one  somewhat  longer,  which  is  open  at  the  side;  this  of  coui'se 
interferes  witli  the  complete  shutting-in  of  the  pneumatic  chamber,  a 
matter,  however,  of  no  consequence  as  this  chamber  is  not  wanted 
during  an  operation. 

*  'ZeitbcLr.  f.  Mikr.,'  ii.  (1880)  p.  175. 


INVEETEBRATAj   CRYPTOGAMIA,    MICROSCOPY^   ETC. 


711 


If  whilst  the  Microscope  is  in  position  the  air  in  the  external 
auditory  passage  is  slightly  condensed  or  rarefied  by  apjilying  the 
mouth  to  the  tube,  it  will  be  seen  how  the  tympanic  membrane  and 
the  manubrium  of  the  malleus  are  respectively  set  in  motion ;  and 
a  more  definite  judgment  can  be  „      _„ 

formed  as  to  anomalies  of  tension 
in  pathological  alterations  of  tissue. 
This  can  be  exactly  measured  by 
connecting  the  tube  with  a  mer- 
curial manometer.  A  most  im- 
portant feature  in  connection  with 
the  instrument  is  the  fact  that  by 
means  of  it  the  caj^acity  for  vibra- 
tion of  the  acoustic  ajjparatus  can 
be  studied  in  living  persons.  For 
this  purpose,  the  tympanic  mem- 
brane, or  if  this  is  wanting  as  well 
as  malleus  and  incus,  then  the  stapes 
must  previously  be  sprinkled  over 
with  powdered  starch,  by  blowing 
a  little  into  the  auditory  passage. 
The  starch  particles  appear  under 
an  intense  light  as  strongly  reflect- 
ing points.  On  speaking  or  singing 
loudly  in  the  mouth-piece  of  the 
tube,  it  will  be  seen  that  particular 
particles  of  starch  are  drawn  out 
into  small  lines,  from  which  the 
capacity  for  displacement  of  the 
powdered    parts,    as   regards    tlie 

action  of  sounds,  can  be  measured  by  means  of  tbu  lui. 
eye- piece. 

The  small  mobility  possessed  by  the  other  segments  of  the 
tympanic  membrane  compared  with  those  of  the  posterior  portions,  then 
becomes  very  apparent,  and  especially  in  certain  pathological  con- 
ditions we  arc  able  to  detect  how  the  mobility  of  the  parts  is 
not  reduced,  but  considerably  increased  contrary  to  what  is  usually 
assumed.  The  instrument  will  in  general  lead  to  conclusions  respecting 
changes  of  diagnostic  importance  such  as  could  in  no  way  be  supposed 
with  the  ordinary  mode  of  examination  with  intense  sunlight ;  for 
instance,  accumulations  of  secretion  behind  the  tympanic  membrane, 
which  would  otherwise  be  invisible,  can  be  plainly  seen. 

Trichina-Microscopes— Hager's,  Schmidt  and  Haensch's,  Waech- 
ter's,  and  Teschner's. — The  number  of  Trichina-Microscoiies  invented 
in  Germany  is  continually  on  the  increase.  The  following  are  four 
forms  which  do  not  aj^pcar  to  havo  been  hitherto  described  in 
this  country  : — 

Hagcrs  *  is  shown  in  Fig.  59,  and  is  said  to  be  very  useful,  not 

*  H.  Hagir,  '  Diis  Mikroskoi* '  (8vc,  Iloiliii,  l^TJ). 


A-  in  the 


712 


KECOKD    OF   CURRENT    RESEARCHES   RELATING    TO 


Fig.  59. 


only  in  tlie  case  of  Trichince,  but  also  for  vegetable  tissues.  It  is  a 
Microscope  combined  with  a  compressorium.  The  latter  consists  of 
a  metal  ring  c,  wliich  is  pressed  upon  the  stage  by  a  spring  /,  and 
can  be  released  by  pressing  the  lever  d.  The  ring  being  raised,  the 
object  to  be  examined  (placed  between  two  glass  plates)  is  laid  upon 

the  stage,  and  the  ring  is 
then  allowed  to  descend 
gently  upon  the  plates. 

Schmidt  and  Haenscli's 
(shown  in  Figs.  60  and  61) 
also  includes  a  combined  stage 
(E)  and  a  compressorium  (C) 
(acted  upon  by  two  screws), 
but  has  in  addition  a  special 
arrangement  for  coarse  and 
fine  adjustment  of  focus.  The 
inner  tube  carrying  the  eye- 
piece and  objective,  which 
slides  within  the  outer  tube 
attached  to  the  pillar  of  the 
Microscope,  is  provided  with 
a  projecting  pin  which  moves 
in  a  slot  cut  obliquely  in  the 
outer  tube  like  the  thread  of 
a  screw,  so  that  by  rotating 
the  milled  rim  (B)  of  the  inner 
tube  it  is  made  to  slowly  as- 
cend and  descend  as  desired. 
It  is  claimed  *  for  this 
plan  that  it  obviates  a  defect 
in  centering  found  to  exist 
in  Microscopes  with  the  ordi- 
nary sliding  adjustment,  with 
which  it  constantly  happens 
that  after  the  tube  has  been 
drawn  up  to  change  the 
"  powers,    a     suspicious    spot 

which  it  was  desired  to  examine  is  found  to  have  disaj^peared  from 
the  field  of  view.  The  objection  to  the  arrangement  will  probably  be 
found  in  the  tendency  of  the  tube  to  "  run  down  "  ;  at  least  that  was 
found  to  be  so  in  the  case  of  an  arrangement  somewhat  analogous 
in  principle,  proposed  by  Mr.  Fiddian  some  years  ago. 

The  second  improvement  claimed  is  the  movement  of  the  stage 
in  two  rectangular  directions  by  the  lever  A  and  rack  and  pinion  D. 
It  is  pointed  out  that  it  is  impossible  even  for  a  practised  micro- 
scopist  to  move  the  object  in  the  absence  of  mechanical  apjiliances 
without  missing  any  portion  of  the  surface.  By  means  of  a  test 
plate  consisting  of  a  photograph  (a  square  German  inch  in  size)  of 
the  numbers  1  to  700,  small  enough  to  be  clearly  legible  under  a 
high  power,  it  was  found  that  the  error  was  as  much  as  30  per 
*  Sco  '  Imliishie-lilaltcr,'  xvi.  (1879)  p.  289. 


INVERTEBKATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


713 


Fig. 


cent.,  and  as  the  figures  were  more  readily  distinguishable 
Trichince,  the  error  in  the  latter  case 
will  jn-obably  be  still  greater,  and  a 
matter,  therefore,  of  some  importance. 
The  construction  and  advantages  of 
this  mechanical  stage  are  described  by 
the  inventors  somewhat  on  first  prin- 
ciples (much  in  the  same  way  as  the 
matter  would  have  been  dealt  with 
fifty  years  ago  in  this  country),  and 
appear  to  show  a  greater  want  of  fa- 
miliarity with  mechanical  stages  than 
we  should  have  supposed  to  exist. 

With  the  Microscope  are  supplied 
the  two  long  strips  of  plate  glass 
shown  in  the  figure,  between  which 
specimens  of  the  meat  to  be  examined 
are  placed.  The  lower  and  thicker 
one  has  five  squares  drawn  upon  it, 
each  measuring  a  square  (German) 
inch. 

Waeclders.  *  —  The  describer  of 
this  form  suggests  that,  ingenious  as 
the  construction  of  the  one  previ- 
ously mentioned  is,  it  possesses  several 
drawbacks,  one  of  which  is  that  "  it  is 


than 


Fig.  61. 


'  I'liariiiiiccutiaclif  (.Vntialliullc,'  i.  (1880)  \k  102. 


714 


RECORD   OF    CURRENT   RESEARCHES   RELATING    TO 


rather  complicated  and  if  used  daily  for  several  Lours  would  be  likely 
to  want  rci)airing,"  and  another,  that  it  cannot  be  used  as  an  ordinary 
Microscope. 

In  the  new  form,  shown  in  Fig.  62,  the  slide  is  composed  of  two 


Fig.  G2. 


circular  glass  plates,  5  mm.  thick  and  8  cm.  in  diameter,  which  are 
pressed  firmly  together  by  a  metal  knob  at  their  centre.  They  thus 
form  a  compressorium  at  the  same  time.  The  under  plate,  which  may 
of  course  be  thickly  covered  with  the  preparations,  is  divided  into 
four  sections,  which  are  numbered  for  identification.     To  prevent  any 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


715 


fluid  coming  away,  the  under  plate  may  be  made  a  very  little  larger 
than  the  upper. 

These  plates  are  turned  with  the  finger  about  their  axis  (which  is 
fixed  to  the  stage  so  as  to  move  from  behind  forwards,  and  vice  versa), 
an  arrangement  which  allows  the  examination  of  a  continuous  series 
of  preparations  lying  in  the  ijcripheries  of  different  circles  18  to 
24  cm.  in  circumference,  whilst  by  the  instrument  last  described  a 
continuous  line  of  only  aboxit  3  cm.  in  length  can  bo  examined. 

When  one  periphery  has  been  examined  (which  is  indicated  by  a 
catch-spring),  a  rack  and  pinion  moves  the  plates  in  a  radial  direction 
(as  a  rule  it  is  best  to  begin  with  the  inner  circle),  and  they  are  again 

Fig.  (Jo. 


revolved ;  and  so  on  until  the  last  periphery  has  been  examined.  There 
is  hero  the  great  advantage  that  in  adjusting  a  fresh  circle  the  size  of 
the  field  corresponding  with  tlie  power  used  can  be  taken  into  account. 
Thus  tho  lowest  power  recjuires  the  rack  to  bo  moved  three  teetli,  the 
medimn  jjowcr  two  teeth,  and  the  highest  jiower  one  tootli  forward. 

\Vh(!n  tlio  plates  are  r-enioved  from  the  stage  the  instrument  can  be 
used  as  an  ordinary  ]\Iicrosc(jj)e. 

Ti'schurs  *  is  a  simpler  form,  of  tho  design  shown  in  Fig.  63. 

It   has   a   wide   inclined  stage,  on  which  is  a  bar   attached  to  two 

supports,  after   the   manner  of  a  parallel  ruler.     ]5y   means  of  tho 

adjusting  screw  h,  the  bar  can  be  moved  to  and  from  the  aperture 

*  1"'.  W.  llufltrt, '  MikiObkopiBchc  Flcibchboschau  '  (8vo,  Leipzig,  li<yO)  j).  51. 


716 


RECOED    OF    CURRENT    RESEARCHES   RELATING    TO 


in  tlic  stage.  Ui3on  the  stage  is  a  compressorium.  The  bar  is  first 
brouglit  close  to  the  pillar  of  the  Microscope,  and  the  compressorium 
moved  along  it  until  all  the  flesh  in  that  strip  has  been  examined. 
The  bar  is  then,  by  means  of  the  adjusting  screw  h,  advanced  for  a 
distance  equal  to  the  diameter  of  the  field  of  view,  and  the  compres- 
sorium is  then  moved  in  the  reverse  direction,  and  so  on.  The  square  a 
is  said  *  to  be  a  small  scale  for  the  purpose  of  determining  the  extent 
of  movement  each  time.  On  account  of  the  depth  of  the  compres- 
sorium, it  must  be  reversed  in  order  to  examine  it  comi^letely. 

Matthews'  Improved  Turntable.  —  There  have  been  many  im- 
provements suggested  in  microscopical  turntables,  most  of  which  have 
dealt  with  the  means  for  securing  the  glass  slide  upon  the  table.  Very 
few  improvements  have  been  made  in  the  means  for  imparting  the 
necessary  rotatory  movement  to  the  table,  and  none  which  have  come 
into  general  use. 

Dr.  Matthews'  invention  has  for  its  chief  object  to  provide  a 
ready  and  efficient  means  for  obtaining  a  rapid  and  steady  rotary 
motion  to  the  table,  without  adding  materially  to  its  complexity  and 
consequent  cost,  as  at  present  constructed.  This  object  he  effects 
thus : — 

Fig.  64  is  a  plan  view  of  the  machine,  and  Fig.  65  a  side  view  of 
the  same,  both  figures  being  drawn  \  size. 

Fig.  64. 


A  A  is  a  base-board  of  mahogany,  upon  which  is  erected  the  plat- 
form B  which  serves  as  a  support  for  the  wrist  of  the  operator.  This 
platform  is  hinged  at  h,  so  that  it  can  be  turned  up  out  of  the  way 
when  desired.  Near  the  front  end  of  the  base-board  A  is  secured  a 
pivot-pin  c'.  Upon  this  pivot-pin  is  mounted,  so  as  to  turn  freely, 
a  broad  flanged  pulley  D.  Above  this  pulley  is  mounted  the 
turntable  E,  also  turning  freely  upon  the  pivot-pin.  The  under 
side  of  the  turntable  is  provided  with  a  short  neck  e,  having  a  ring  of 
ratchet  teeth.  The  upper  flange  of  the  pulley  is  fitted  with  a  spring 
pawl  d,  which  engages  with  the  ring  of  ratchet  teeth  on  the  under  side 
of  the  turntable.  Underneath  the  platform  B  a  flat  spring  F  is 
secured  by  one  of  its  ends,  and  to  the  free  end  of  this  spring  is  attached 
a  cord,  which  is  led  forward  and  passed  around  the  pulley.  It  is  then 
carried  over  a  second  pulley  G,  from  which  it  hangs  pendent. 

*  The  figure  is  a  '  cliche  '  from  tlie  original  woodcut. 


INVERTEBKATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


717 


It  will  be  readily  iinclcrstood  from  the  foregoing  description  that 
by  pulling  downwards  upon  the  cord  a  rotary  movement  will  be 
imj)arted  to  the  pulley  D,  and  through  the  pawl  and  ratchet  teeth  to 
the  turntable  E.     By  relaxing  the  pull  upon  the  cord,  the  spring  F 


Fig.  65. 


will  draw  the  cord  back  again,  carrying  round  the  pulley  D  and  pawl 
d  in  the  reverse  direction.  The  weight  and  momentum  imparted  to  the 
turntable  will  be  sufficient  to  maintain  its  rotation  during  this  backward 
movement  of  the  pulley,  and  by  a  repetition  of  the  process  the  rotation 
of  the  turntable  may  be  continued  as  long  as  desired. 

In  order  to  hold  the  slide  in  a  central  position  upon  the  turntable, 
two  metal  slips  //  are  pivoted  at  their  oi)posite  ends  to  the  surface 
of  the  table.  These  slips  are  provided  with  springs  which  bear  against 
the  heads  of  screws  on  the  upper  side  of  the  table.  By  this  means  the 
slide  will  always  be  accurately  centered  laterally.  Its  adjustment 
longitudinally  can  be  effected  by  the  aid  of  a  ring  engraved  in  the 
surface  of  the  table. 

It  is  often  desirable,  however,  to  apply  a  circle  of  cement  excentri- 
cally.  This  is  especially  the  case  in  re-ringing  old  slides.  The 
adjustment  longitudinally  can  be  readily  made  as  already  cxphiiued, 
and  can  of  course  be  made  either  central  or  excentric.  To  provide 
for  an  excentric  adjustment  laterally,  tlie  toj)  of  the  table  is  formed  of 
a  movable  disk,  which  is  jjivotcd  at  c\  This  disk  is  secured  in  a 
central  position  by  mcaiis  of  a  millcd-lieadcd  screw  e-.  By  withdraw- 
ing this  screw  slightly  the  disk  is  set  free  and  can  be  shifted  laterally 
as  indicated  by  the  dottetj  lines  in  Fig.  G4,  so  that  any  amoinit  of 
exceutricity  can  bo  given  to  the  disk,  and  consequently  to  the  slide 
which  it  carries. 

It  is  obvious  that  the  pulley  G  may  be  placed  elsewhere  on  the 
base-board  A,  or  may  be  disjjeused  witli  altogether,  in  wliich  case  a 
direct  pull  upon  the  cord  can  bo  used  to  impart  motion  to  the  turntable. 


(    718    ) 
BIBLIOGEAPHY 

OF   CUEEENT   RESEARCHES   RELATING   TO 

INVEETEBEATA,  CEYPTOGAMIA,  MICEOSCOPY,  &c. 


JOUKNALS,  TEANSACTIONS,  &c.,  the  contents  of  which  are  noted 

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275  figs.     (8vo.     London,  1880.) 
„  „        On  the  Structure  and  Homologies  of  the  Germinal  Layer  of 

the  Embryo,     17  figs.  Quart.  Journ.  Micr.  Set.,  XX.,  pp.  247-73. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  721 

Bkaun,  M. — On  the  Developmental-history  of  the  Parrots.     II. 

Verh.  Phys.-Med.  GosclL  Wih-zbrmj,  XIV.,  pp.  251-2. 
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of  Protoplasm.  Arch.  Ne'erJ.  Sci.  exact.  ^  nat.,  XV.,  pp.  148-5-i. 

Flejiming,  W. — On  Epithelium-regeneration,  and  the  so-called  free  Nucleus- 
formation.     (Supplement  to  his  Paper  on  "  The  Cell  and  its  Vital  Phenomena.") 

Arch.  Mikr.  Anat.,  XVIII.,  pp.  347-64. 
Flesch,  M. — On  the  Cell  and  Intercellular-substance  iu  Hyaline  Cartilage. 

Verh.  Phi/s.-iUed.  Gesell.  Wiirzbur//,  XIV.,  SB.,  pp.  iii.-vi. 
Fox,  L.  W. — The  Asymmetry  of  the  Face  in  Human  Embryos. 

3IT.  Embrt/»l.  hist.  K.-K.  Univ.  Wien,  I.,  pp.  279-85. 
Frankland,  E. — On  the  Spontaneous  Oxidation  of  Organic  Matter  iu  Water. 

[Jcnu-n.  Chem,  Soc,  XXXVII.,  pp.  517-4G.] 
GiBBES,  H. — On  the  Structure  of  the  Spermatozoon.     1  fig. 

Qiiart.  Journ.  Micr.  Soc,  XX.,  pp.  320-1. 
Hai.pryn,  p. — Communications  on  the  Kesults  of  an  Investigation  on  a  prema- 
ture Human  Embryo.    Plato  22,  23-4. 

MT.  Embri/ol.  Inst.  K.-K.  Univ.  Wicn,  I.,  pp.  235-54. 
Hannover,  A. — The  Primordial  Cartilage  and  its  Ossification  in  the  Human 
Skull  before  Birth.     2  plates  (explanation  in  French). 

K.  Dansk.  Vidensk.  Skr.  {Copcnhcu/en),  XI.,  pp.  354-528. 
Hanstein.,  J.  v. — The  Influences  of  Cell-nuclei  on  the  Division  of  Cells.  \_Abstr. 
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Naturf.,  XIII.,  pp.  220-1. 
Hogg,  J. — Impure  Drinking-water — its  Sanitary  Import.     11  figs. 

En'jl.  Mech.,  XXXI.,  pp.  425-6. 
Horvath,  G.  v. — On  Periodic  Phenomena  in  the  Animal  World  {conckl.'). 

Entomol.  Nachr.,  VI.,  pp.  109-15. 
JouRDAiN,  S. — On  the  Existence  of  a  Lymphatic  Circulation  in  Pleuronectes. 

Comptes  L'cndus,  XC,  pp.  1430-2. 
Knop,   W. — On  Albuminous   Bodies.     \^Abstr.    from    '  Berichto    Ub.  d.   Verb. 
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Krause,  E. — Notes  on  the  Developmental-history  of  Embryology. 

Kusmos,  IV.,  pp.  257-75. 
Krause,  W. — On  a  premature  Human  Embryo.  Zool.  Ameig.,  III.,  pp.  283-4. 
LippiNCOTT,  J.  S. — Tlie  Critics  of  Evolution  {contd.). 

Am.  Nat.,  XIV.,  pp.  398-41G. 

Neumann,    E. — On    Degeneration    and    Regeneration    of    Injured    Nerves. 

Plate  IG.  Arch.  Mihr.  Anat.,  XVIII.,  pp.  302-44. 

Peck,  M.  R.  C. — Cyst-formation  in  the  Boily-wall  of  the  Embryo.     Plato  27. 

MT.  Emhryol.  Inst.  K.-K.  Univ.  Wicn,  I.,  i>p.  287-91. 

Pouchct. — The  Origin  of  the  Red  Blood-corpuscles.      [^Traasl.   from  'Revue 

Scienfifique.']  Quirt.  Junm.  Micr.  >'ci.,  XX.,  pp.  331-50. 

Rawitz,  B. — On  the  Structure  of  the  Spinal  Ganglia.     Plate  15. 

Arch.  Mikr.  Anat.,  XVIII.,  pp.  283-301. 
Scuenk. — On  the  Influence  of  Colour  on  tiie  Development  of  Animals. 

3IT.  Kmhrijol.  hist.  K.-K  Univ.  Wicn,  I.,  pp.  205-77. 
Sedgwick,  A.— On  the  Development  of  the  structure  known  as  the  "Uloinerulus 
of  the  Hcad-kidiicy  "  in  the  Chick.  Quart.  Journ.  Micr.  Sci.,  XX.,  pp.  372-4. 

Slatek,  J.  W. — The  "  Laws  of  Emphasis  and  Syinmefry." 

./vurn.  of  Sci.,  II.,  pp.  434-8. 
SoLGEK,  B. — Further  Researches  on  tho  Anatomy  of  the  Lateral  Organs  of 
Fishes.     III.  The  Lateral  Organs  of  tho  Osseous  Fishes. 

Arch.  Mikr.  Anal.,  XVIII.,  pp.  304-90. 

Vincnow,   H.  J.  P. — Vessels  of  the    Vitreous    Bo<ly  an<l   Vascidar  Lens  in 

Aiiitiial  ICmbryos.  Verh.  Ph;i>!.-Mcd.  Oc.cH.   Wiirzbur;),  XIV.,  SH..  pp.  .\x.-xxii. 

Waili.y,  a. — Hybrids  and  Di  gcnernry.  Eutmnnl.,  XIII.,  pp.  151-8. 

\Vii,.MON,  II.  C. — On  tlic  Development  of  tho  Human  Skin.     Fliitrs  2r)-(!. 

MT.  Embruol.  Inst.  K.-K.  t'nir.   Win,,  I.,  pp.  255-64. 


VOL.    III. 


722  BIBLIOGRAPHY    OF 

B.  INVERTEBRATA. 

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MoUusca. 

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Ball.  Sci.  Dep.  No'rd,  III.,  pp.  193-7. 
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Journ.  de  Condi.,  XX.,  pp.  140-2. 
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Journ.  de  Conch.,  XX.,  pp.  142-9. 
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HiNCKS,  T.— Contributions  towards  a  general  History  of  the  Marine  Polyzoa. 
Plates  9-11.     {In  part.)  Ann.  #  Mag.  Nat.  Hist.,  VI.,  pp.  69-92. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  723 

Oehlert,  D.— The   Sj-steniatic;   Position  of  the   Brachiopoda  according  to 
M.  Moise.  Jour7i.  de  Conch.,  XX.,  pp.  109-35. 

Shrtbsole,  G.  W. — A   Keview  and   Description  of  the  various  Species  of 
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Bryan,  G.  H. — Notes  on  the  Nests  of  European  Trap-door  Sjiidcrs  (cotitd.). 

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8  I)  2 


724  BIBLIOGRAPHY    OF 

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INVEETEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  725 

Krabbe,   H. — Eeseavches  on   the  occurrence    of   Intestinul   Worms  in  the 
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Cherry-tree,  and  on  Exoascus  Wiesneri  Rathay. 

Oesterr.  Bot.  Zeitschr.,  XXX.,  p.  225. 
Ribbert,  H. — A  Micro-parasitic  Invasion  of  the  whole  Cortical  Layer  of  tkc 
Brain.     [Bacteria.]    Plate  X.,  fig.  5. 

Arch.  path.  Anat.  ^  Physiol.  {Yirchow'),  LXXX.,  pp.  505-G. 
RoBSON,  M.  H. — Tlie  Salmon  Disease  and  its  Cause.     1  fig. 

Sci.-Gossip,  1880,  pp.  129-32. 

Saccabdo,  P.  A. — Conspectus  generura  fungorum  Itali.'B  inferiornni,  nempe  ad 

Sphseropsideas,  Melanconieas  et  Hyphomyceteas  pertinentium,  systemate  sporo- 

logico  dispositoruni.      [Latin.]  Michclia,  1880,  No.  6,  pp.  1-38. 

„  „         Fungi   Gallici   lecti  a  cl.  viris  Brunaud,  Lotendre,  Mal- 

brache,  Theny  v.  editi  in  Mycotheca  Gallica  C.  Roumegucri.     Str  II.     [Latin.] 

Michclia,  1880,  No.  6,  pp.  39-135. 
„  „  Fungorum  extra-europseorum  Pugillus.     [Latin.] 

Michclia,  1880.  No.  6,  pp.  136-49. 

„  „  Fungi  Dalmntici  pauci  ex  herb,  illustr.  R.  do  Visiani,  addito 

unoalterovemyceteex  AngliaetPannonia.  [Latin.]  Michdii, li>SO,^o.  6, ]>p.  l,")0-3. 

„  „  Fungi  Vi  iieti  novi  vol  critici  v.  Rlycologife  Venetro  addend i. 

Series  XI.  Michclia,  1880,  No.  6,  pp.  154-7G. 

Schultze,  II. — TIk;  Theories  as  to  Area  Celsi.     Plates  4-5. 

Arch.  path.  Anat.  <J-  Physiol.  (  Virchow),  LXXX.,  pp.  193-247. 
TuuEMEN',  F.  UE. — Diagnoses  to  Centuries  13-15  of  '  ]\iycotlucii  universalis.' 
{/npart.)  Flora,  LXIII.,  pp.  312-22. 

White,  F.  B.— Preliminary  List  of  the  Fungi  of  Pcrthsliirc  (n,,dd.). 

ticuli.  ^al.,  v.,  pp.  320-5. 


730  BIBLIOGRAPHY    OF 

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the  Spoi-es  in  the  Ascomycetes,  and  on  some  results  which  have  thereby  been 
established.     [From  '  SB.  Gescll.  Naturf.  Freunde,'  1880,  No.  2.] 

Bedwigia,  XIX.,  pp.  94-9. 
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Cakestia,  a. — See  Baglietto,  F. 
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Barkas,  T.  p.— Marine  Diatomaceas.  Engl.  Mcch.,  XXXI.,  p.  304. 

Baekas,  T.  p.,  Bkown,  G.  D.,  Fedakb,  J.,  Hogg,  J.,  Peal,  C.  N.,  and  Shrub- 
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Engl.  Mech.,  XXXI.,  pp.  276,  304,  325-6,  356,  374,  405-6. 
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Cooke,  M.  C. — British  Desmids.  Grevillea,  VIII.,  pp.  121-8. 

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Fedakb,  J. — Mineralized  Diatoms.  Engl.  Mech.,  XXXI.,  pp.  874-5. 

J,         ,,       Bacillaria  parachxa.  ,,  „  p.  453. 

„         „    .  See  Barkas,  T.  P. 
FiNDON,  C.  J.  B. — Bacillaria  paradoxa.     5  figs.  „  ,,  pp.  452-3. 

Geunow,  a. — Observations  on  J.  Brun's  Diatomacese  Flora  of  the  Alps. 

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Journ.  de  Microg.,  III.,  pp.  497-500 ;  IV.,  pp.  40-2. 
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Hogg,  J.— Sec  Barkas,  T.  P. 
KiTTON,  F. — The  Early  History  of  the  Diatomaceae  (contd.). 

Sci.-Gossip,  1880,  pp.  133-6. 
Kjellman,  F.  K. — On  the  Alga-Vegetation  of  the  Glacial  Sea  of  Siberia. 

Ofvers.  K.  Vet.-Akad.  For.,  XXXVI.,  No.  9,  pp.  23-28. 
Peal,  C.  N.— .See  Barkas,  T.  P. 

Eichtee,  p. — On  the  Change  of  Colour  in  some  Fresh-water  Algse,  especially 

the  Oscillatoriefe.  Bot.  Centralbl.,  I.,  pp.  605-7. 

Sheubsole,  W.  H. — Mineralized  Diatoms.  Engl.  Mech.,  XXXI.,  p.  451. 

„  „  Bacillaria  parado.ca.  „  „         p.  453. 

„  See  Barkas,  T.  P. 

Stoddee,  C. — About  Diatoms.  Am.  Mon.  Micr.  Journ.,  I.,  pp.  113-5. 

"VViLLE,  N. — Fresh- water  Algse  from  Nova  Zembla  collected  by  Dr.  F.  Kjellman 

in  Nordenskiold's  Expedition,  1875.    Plates  12-14. 

Ofvers.  K.  Vet.-Akad.  For.,  XXXVI.,  No.  5,  pp.  13-74. 
WoKONiN,  M. —  Vaucheria  Be  Baryana,  n,  sp.     Plate  7. 

Bot.  Zeit.,  XXXVIII ,  pp.  425-32. 
YoUSG,  J. — Notes  on  the  Occurrence  of  a  Species  of  Boring  Marine  Alga 
penetrating  the  Shell  Structure  of  a  Species  of  Productus. 

Proc,  Kat.  Hist.  Soc,  Glasgow,  IV.,  pp.  77-8. 


INVERTEBEATA,    CEYPTOGAMIA,   MICROSCOPY,    ETC.  731 


MICROSCOPY,  &c. 

Adams,  L.  E.— Preserving  Crustacea.  Sd.-Gossip,  1880,  p.  138. 

Albrecht. — A  simple  Method  for  the  Microscopical  Examination  of  Blood 

for  Spirillum.  [_Medic.-Chir.  Rundschau,  XIX.,  p.  508.] 

AwDRY,  Mrs.  W. — Easy  Lessons  in  Light.     114  pp.     43  figs.    (8vo.   London, 

1880.) 

" B.  R,"  » B.Sc,"  Cark,  E.,  Edmunds,  J.,  Grey,  W.  J.,  and  Standage,  H. C. 
— Chromatization  of  Light  by  a  Microscopic  SlMe. 

Engl.  Mech.,  XXXI.,  pp.  276-7,  303,  303-4,  304,  325, 

354,  379,  399,  399-400,  421-2,  422,  447. 

Barnard,  F. — On  the  Use  of  Carbolic  Acid  in  Mounting  Objects  for  the 

Microscope.  Sci.-Gossip,  1880,  pp.  137-8. 

Bizzozero,  G.— The  Chromo-Cytometer.      New  instrument  for  determining 

the  amount  of  Haemoglobin  in  the  Blood. 

[Med.  Jahrh.,  Wien,  1880,  pp.  251-67.] 

Blackham,   G.  E. — The  Tolles-Blackham  Microscope,  P.  anijulatum,  Amphi- 

pleura  pellucida,  &c.  Engl.  3Iech.,  XXXI.,  p.  400  [and  see  p.  420]. 

Brittan,  W.  C. — Preparing  Slides.  Am.  Journ.  Micr.,  V.,  p.  139. 

BuTTERWORTH,  J. — Cutting  and  Grinding  Rock  Sections.     2  figs. 

Engl.  Mech.,  XXXI.,  p.  277. 
Calderon  y  Arana. — Schneider's  Polarizing  Apparatus.     1  fig. 

Anal.  Soc.  Espan.  Hist,  Nat.,  IX.  (^Actas)  pp.  35-8, 
Carb,  E.—Scc  "B.  R." 
Ceetes,  a. — On  the  Micrographic  Analysis  of  Water. 

Cumptes  Rendus,  XC,  pp.  1435-7. 
Clevenger,  S.  V. — Microscopic  Examination  of  Tissues  after  tiie  Adminis- 
tration of  Mercury.     {In  part.)  Am.  M.  Micr.  Junrn.,  I.,  pp.  110-13. 
Crus,  R. — Telescope,  Microscope,  and  Aquarium  Difficulties  and  Manipuhx- 
tion.     2  figs.  Enjl.  Ilech.,  XXXI.,  p.  448. 
Diatoms,  Directions  for  Cleaning,     (fn  part.) 

Am.  M.  Micr.  Journ..,  I.,  pp.  107-10. 
Edmunds,  J. — See  "  B.  R," 

"  Fellow  of  the  R.  Micr.  Soc." — [Grubb's  Microscope,  1  fig. ;  Paraboloid 
Diaphragms  (Williams) ;  New  Formula  Objective  (Powell  and  Lealand's) ; 
"  Numerical  Aperture  "  as  defined  by  Prof.  E.  Abbe.] 

Engl.  Mech.,  XXXL,  pp.  275-6. 
„  „  [Opaque  Illumination  for  the  Microscope ;  a 

Correction.     Engl.  Mech.,  XXXL,  p.  302. 
„  „  [Tolles's  Opaque  Illuminator  for  the  Micro- 

scope ;  Prof.  H.  L.  Smith's  Vertical  Illuminator ;  Experimental  Demonstration  of 
Apertures,  &c. ;  Paraboloid  Diaphragms.]  Engl.  Mech.,  XXXI.,  pp.  324-5. 

„  „  [Powell  and  Lealand's  new  Oil-itnincrsiou 

Condenser  at  the  Quokett  Club  and  Royal  Society  ;  New  Formula  Objectives ; 
Royal  Microscopical  Society ;  80,000  Diameters  (?) ;  Athletics  of  Microt^copy.] 

Engl.  Mech.,  XXXL,  pp.  373-4. 
„  „  [Paraboloid  Diaphragms ;  Dr.  Blackham  ou 

Microscope-stands  and  English  and  American  Microscopy.] 

Engl.  Mech.,  XXXL,  p.  420. 

FouQVK,  F.,  and  A.M.  Levy. — Micrograph ical  Mineralogy — French  iM-uptivo 

Rocks.     (Ministere  des  Travaux  publics. — Memoires  pour  servir  k  rexplicatiou 

do  la  Carte  Ge'ologiquc  de'taille  de  la  France.)    509  pp.    55  plates.    (4to.    Paris. 

1879.) 

George,  G.  F.-Dull  Objectives.  Sci.-Gossip,  18S0,  p.  159. 

GiBBES,  H. — On  the  Use  of  the  Wenliam  Binocular  with  High  Powers. 

Quart.  Journ.  Micr.  Sci.,  XX.,  pp.  318-19. 
Grey,  W.  .T.—Sec  "  B.  R." 

Grubb's  Microscope. — Sec  "  Fellow,"  &c.,  and  "  Observer." 
Hesciil  — Contribution  to  the  History  of  the  Compound  Micro.scopc.    Plate  1>^. 

'  Arch.  Mikr.  AwU.,  XVIIL,  pp.  391-402. 


732       BIBLIOGRAPnY    OF    INVERTEBRATA,    CRYPTOGAMIA,    ETC. 

Iris  Diaphragm  an  old  invention.  Am.  Joum.  Micr.,  V.,  pp.  13G-7. 

KoETiNG. — A  new  Microtome.     (1  fig.) 

Jen.  Zeitschr.  Natnriciss.,  VII.,  pp.  193-5. 
Levick,  J. — Pond  Life  :  where  to  find  Anuraa  longispina. 

Midi.  Nat.,  III.,  pp.  166-7. 
Levy,  A.  M. — See  Fouque,  F. 

Medical  Postal  Microscopical  Society.  Am.  Joum.  Micr.,  V.,  pp.  117-18. 

Mees,  C.  L.— Blood  Stains.  [died.  Herald  (Louisville),  II.,  p.  89.] 

MosELEY,   H.   N. — Remarks  upon  some   Specimens   of  Sections   of   Corals 

prepared  by  Koch's  Method.  Froc  Zool.  Soc.  Land.,  1880,  pp.  24-7. 

„  Description  of  a  new  Species  of  Simple  Coral.     ^  figs. 

Proc.  Zool.  Soc.  Land.,  1880,  pp.  41-2. 
"  Observer."— The  Grubb  Micros'-'ope-stand.  Engl.  Mech.,  XXXI.,  p.  420. 

Pelletan,  J. — The  Camera  Lucida  of  Dr.  J.  G.  Hofmaim.     4  figs. 

Joum.  de  Microg.,  III.,  pp.  484-5. 
„  „      Gundlach's  Hemispherical  Immersion  Coinlenser.    4  figs. 

Joyrn.  de  Microg.,  IV.,  pp.  21-4. 
„  „      The  Camera  Lucida  of  Dr.  J.  G.  Hofmann.     3  figs. 

Joum.  de  Microg.,  IV.,  pp.  25-6. 

Pennock,  E. — The  Binocular  Microscope.  Engl.  Mech.,  XXXI.,  p.  304. 

Peticolas,  C.  L. — Some  new  Slides  from  the  Richmond  (Virginia)  Diutoma- 

ceous  Earth.  Am.  Joum.  Micr.,  V.,  pp.  133-4. 

Phin,  J. — Micromillimetre,  Micrometre,  or  Sixth-metre. 

Am.  Joum.  Micr.,  V.,  p.  117. 
Piper,  R.  U. — Cleaning  Cover-glasses.  Am.  Nat.  XIV.,  pp.  465. 

Powell  &  Lealand's  New  Formula  Objective — See  "  Fellow,"  &c. 
QuiKOGA,  F. — Micrographical  Study  of  some  Basalts  of  Ciudad-Real.    Plate  3 
to  follow.  AnaL  Soc.  Espun.  Hist.  Nat.,  IX.,  pp.  161-79. 

Romeo,  Nelly  A. — Pleurosigma  angulatum.       Am,  Joum.  Micr.,  V.,  pp.  137-8. 
Row,  F.— A  new  Collecting  Bottle.     1  fig.  Sci.-Gossip,  1880,  p.  136. 

Sanio,  C. — On  the  Preparation  of  a  suitable  Asphalts  Varnish  for  Micro- 
scopical Slides.  But.  CentralU.,  I.,  pp.  90-1 . 
Seiler,  C. — Microscopic  Examination  ;  Preparation  of  Tissues  (contd.). 

[Med.  Herald  (Lo'iisville),  II..  pp.  87-9.] 
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Anal.  Soc.  Espan.  Hist.  N  t.,  IX.  (Adas),  pp.  20-1. 
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Sokby,  H.  C— On  the  Structure  and  Origin  of  Non-Calcareous  Stratified 
Rocks.     11  figs.    [Anniversarv  Address.] 

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Standage,  H.  C.—See  "  B.  R." 
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Suffolk,  W.  T.— Tlje  President's  Address,   1880.     [South  London  Micro- 
scopical and  Nat.  Hist.  Society.]     4  pp.     (Svo.     London,  1880.) 

Tiffany,  F.  B. — Microscopic  Examination  of  the  Blood  in  the  Living  Person. 
[Prepuce.]     2  fio-s.  \St.  Louis  Med.  4-  Surg.  Joum.,  XXXVIII.,  pp.  387-9  ; 

Louisville  Med.  Herald,  II.,  p.  30.] 
"Waters,  A.  W. — Some  Rocks  of  the  Vaudois  Alps  studied  microscopically. 
Plate  24.  Bull.  Soc.  Vaud.  Sci.  Nat.,  XVI.,  pp.  593-8. 

Wenham,  F.  H. — Mr.  Stodder  and  Angular  Aperture. 

Am.  Joum.  Micr.,  V.,  p.  137. 
„  „        On  an  Improved  Immersion-Paraboloid.    3  figs. 

Am.  M.  Micr.  Joum.,  I.,  pp.  101-2. 
Wickersheimer's  Preserving  Fluid.  Entomol.  Nachr.,  VI.,  pp.  129-32. 

Williams,  G. — Paraboloid  Diaphragms. 

Engl.  M'ech.,  XXXI.,  p.  304  [see  also  pp.  275-6,  325,  400,  and  420]. 
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Am.  Joum.  Micr.,  V.,  pp.  108-9. 


(     733     ) 
PEOCEEDINGS  OF  THE  SOCIETY. 


Meeting  of  9th  June,  1880,  at  King's  College,  Strand,  W.C. 
Dr.  R.  Beaithwaite,  F.L.S.  (Vice-President)  in  the  Chair. 

The  Minutes  of  the  meeting  of  12th  May  last  were  read  and 
confirmed,  and  were  signed  by  the  Chairman. 


The  List  of  Donations  (exclusive  of  exchanges  and  reprints)  re- 
ceived since  the  last  meeting  was  submitted,  and  the  thauks  of  the 
Society  given  to  the  donors. 

Microscope  ("  Sketch-Model  "),  formerly  in  the  possession  of  From 

Mr.  Eilwin  Quekett,  one  of  the  original  members  of  this 
Society,  and  esteemed  by  him  and  by  his  brother,  Professor 
Quekett,  as  an  interesting  example  of  early  endeavour  to 
improve  the  construction  of  the  Microscope Mr.C.F.  White. 

Parkes  &  Son's  Microscope  Lamp,  with  Cooling  Evaporator  ..     Messrs.  Parkes and 

Son. 

Pepper  Cane,  Section  of        Mr.  T.  Christy. 

Surirella  gemma  from  Emden,  Prussia,  Bottle  of        Hen-  0.  Brandt. 

Zoological  Station  of  Naples — 12  slides      Tlie  Station,through 

21r.  A.  W.  Waters. 

Mr.  Crisp  called  special  attention  to  the  slides  received  from  the 
Zoological  Station  at  Naples,  which  were  exhibited  under  Microscopes 
in  the  room  (see  p.  700). 


Mr,  Crisp  exhibited  and  described  Waechter's  Trichina-Microscope 
(see  p.  714),  and  Dr.  Weber-Liel's  Ear-Microscope  (see  p.  710),  and 
described  Dr.  Tiffany's  Prepuce-Microscope  (see  p.  709). 


Dr.  Matthews  exhibited  and  described  a  new  form  of  turntable 
(see  \).  710). 

Mr.  Crisp  exhibited  and  explained  a  "Micrometer-Microscope" 
made  by  M.  Hartuack,  a  description  and  illustration  of  which  will  bo 
jjublished  hereafter. 

Mr.  Beck  said  it  had  struck  him  for  some  time  that  there  was  a 
great  deal  of  interest  attached  to  the  question  of  the  jiurity  of  tlio 
water  supply,  and  that  the  reports  sent  in  by  the  inspectors  were  of 
such  an  uniustructive  character  as  to  bo  worth  very  little  indeed  to 
the  general  public,  who  were  the  persons  most  interested  in  the 
matter.  He,  therefore,  thought  that  if  the  Society  as  a  body  could 
do  something  to  instruct  them  as  to  what  were  signs  of  purity  and 
what  were  really  impurities  it  would  be  doing  a  very  good  service. 
Ho  remembered  that  si^me  time  agt)  when  there  was  a  Parliamentary 


734  PROCEEDINGS   OF    THE    SOCIETY. 

Committee  appointed  to  consider  the  subject,  there  were  shown  in 
some  of  the  water  examined  some  monstrous  creatures  which  were 
calculated  to  cause  alarm  to  any  one  ;  but  the  scientific  evidence 
showed  that  the  water  was  really  so  pure  and  free  from  sewage 
contamination  that  it  did  not  kill  the  creatures  which  were  found. 
He  threw  this  out  as  a  hint,  as  he  believed  that  they  ought  to  show 
that  whilst  they  were  a  scientific  body  in  the  highest  sense  of  the 
term,  they  were  capable  of  work  which  would  really  be  of  great 
public  benefit. 

The  Chairman  said  he  quite  agreed  with  Mr.  Beck  in  his  remarks, 
and  invited  the  Fellows  to  act  ui)ou  the  suggestion  made.  He  thought, 
however,  that  they  must  rely  upon  the  action  of  the  working  Fellows 
of  the  Society  rather  than  on  any  committee,  and  hoped  that  during 
the  coming  recess  something  might  be  done  in  the  matter. 


Mr.  J.  W.  Stephenson  read  a  paper  "  On  the  Visibility  of  Minute 
Objects  mounted  in  Phosphorus,  Solution  of  Sulphur,  Bisulphide  of 
Carbon,  and  other  Media  "  (see  p.  564). 

Mr.  Stewart  said  that  the  paper  did  not  relate  to  a  matter  of  mere 
optical  curiosity,  but  to  an  extremely  valuable  means  of  investigation 
as  applied  to  minute  structure,  which  was  brought  out  and  rendered 
visible  with  marvellous  clearness. 


Mr.  Crisp  described  and  commented  on  the  proposed  process  for 
cleaning  Foraminifera  suggested  by  Mr.  K.  M.  Cunningham,  the 
method  recommended  being  electrical  attraction  (see  p.  692),  and 
Mr.  A.  A.  Bragdon's  suggestion  of  the  use  of  glycerine  and  sulpho- 
carbonate  of  zinc  as  a  medium  for  homogeneous  immersion  (see 
p.  701). 

Dr.  Edmunds  read  a  note  "  On  a  Parabolized  Gas  Slide,"  speci- 
mens of  which  were  exhibited  in  the  room  (see  p.  585). 


Mr.  W.  H.  Gilburt  read  a  paper  "  On  the  Structure  and  Function 
of  the  Scale-Leaves  of  Lathrea  squamaria,"  illustrating  the  subject 
by  a  number  of  drawings  on  the  black-board. 

The  Chairman,  in  moving  a  vote  of  thanks  to  Mr.  Gilburt,  re- 
marked that  the  curious  plant  which  had  formed  the  subject  of  his 
paper  was  not  an  uncommon  one,  and  the  paper  showed  how  much 
interest  could  be  got  out  of  a  common  object  if  only  it  were  handled 
by  competent  hands. 

Mr.  Stewart  thought  it  would  be  interesting  to  test  the  nature  of 
the  fluid  secretion  which  Mr.  Gilburt  had  mentioned,  in  order  to  see 
if  it  were  at  all  the  same  as  that  in  the  Drosera  and  other  carnivorous 
plants. 

Mr.  Crisp  exhibited  and  described  Zeiss's  micro-spectroscope  (see 
p.  703),  and  Hartnack's  polarizing  apparatus. 


PROCEEDINGS   OF   THE   SOCIETY.  735 

Mr.  Woodall  gave  a  resum^  of  his  paper  "  On  the  Interference- 
Phenomena  produced  by  Luminous  Points." 


Mr.  Crisp  announced  that  it  had  been  decided  by  the  Council 
that  the  books  in  the  Society's  library  should  be  allowed  to  be  circu- 
lated amongst  the  Fellows  under  regulations  which  would  be  announced 
as  soon  as  the  Assistant-Secretary  had  completed  the  catalogue  of  the 
library  which  he  had  in  hand. 


Professor   Rogers's   paper   "  On   Tolles's  Illuminator  for  High 
Powers  "  was  read. 


Professor  Abbe's  paper  "  On  the  Function  of  Aperture  in  Micro- 
scopic Vision  "  was  taken  as  read. 

Mr.  Crisp  read  a  part  of  a  letter  from  the  author,  in  which  he 
said  :  "  Having  been  often  blamed  for  obscurity,  I  resolved  to  explain 
my  opinions  in  such  a  way  now  that  they  cannot  fail  to  be  under- 
stood." The  paper  would  probably  exceed  150  pages  of  the  Journal, 
and  the  Council  had  therefore  decided  to  print  it  as  a  separate 
volume. 

Mr.  Crisp  said  that  it  had  been  repi-esented  to  him  that  some  of 
the  Fellows  would  like  tliat  the  larger  part  of  the  Journal  should 
consist  of  "  Microscopy,"  i.  e.  matter  relating  to  the  Microscope  as  an 
instrument,  its  modifications,  imiH'ovements,  &c.  As  every  existing 
source  outside  the  Society  was  already  made  use  of  for  "  micro- 
scopical "  notes,  one  of  two  things  must  have  happened  (remembering 
that  the  suggestion  came  from  within  and  not  outside  the  Society) — 
either  communications  from  Fellows  intended  for  the  Journal  had 
accidentally  failed  to  reach  him  from  some  unexplained  cause,  or  it 
was  not  sufficiently  understood  by  the  Fellows  that  the  "  Microscopy  " 
portion  of  the  Record  was  available  for  communications  which 
might  not  be  so  appropriately  jmnted  as  a  formal  "paper"  in  the 
Transactions. 

In  addition  it  must  be  remembered  that  all  tastes  had  to  be  con- 
sulted in  the  compilation  of  the  Journal  (a  point  which  he  liad 
kept  prominently  in  mind),  and  it  was  clear  that  there  was  a  con- 
siderable body  of  the  Fellows  who  took  only  a  secondary  interest  in 
the  Microscope  from  an  instrumental  point  of  view,  and  who  were 
more  especially  concerned"  with  tlie  subjects  which  required  the  aid 
of  the  Microscoi>c  for  their  investigation. 

A  second  point  which  he  wished  to  refer  to  was,  tlmt  it  was 
not  to  be  supposed  tliat  everything  mentioned  in  tlie  Jom-nal  was 
intended  to  be  thereby  certified  as  "  new."  Substantially  he  hud  dis- 
continued the  use  of  that  word  altogether  in  relation  to  microscopical 
matters  on  account  of  the  irritation  it  seemed  to  produce,  but  still 


736  PROCEEDINGS    OF   THE    SOCIETY. 

there  was  never  a  Journal  issued  tliat  he  did  not  receive  more  than 
one  letter  pointing  out  that  what  was  described  had  "  been  done 
before."  *  

A  Special  General   Meeting   was   then    held  pursuant  to  the 
notice  given  at  the  last  meeting  (see  p.  559). 


Dr.  Gray  moved  and  Mr.  Michael  seconded  the  following  resolu- 
tion, which  was  carried  unanimously  : — 

That  the  6th  Bye-law  be  cancelled,  and  the  following  substituted 
in  lieu  thereof. 

"  6.  Every  Fellow  on  his  election  shall  pay  an  entrance  fee  of  two 
guineas. 

"  6a.  The  Annual  Subscription  to  be  paid  by  the  Fellows  shall  be 
two  guineas,  which  shall  become  due  in  advance  on  the  1st  January 
in  every  year.  Fellows  elected  in  any  of  the  months  subsequent  to 
June  shall  pay  one-half  only  of  the  subscription  for  the  current 
year."  

The  following  Objects,  Apparatus,  &c.,  were  exhibited:— 

Mr.  T.  Christy : — Section  of  Pepper  Cane. 

Mr.  Crisp: — Hartnack's  Micrometer-Microscope  ;  Waeehter's 
Trichina-Microscope  (see  p.  714)  ;  Weber-Liel's  Ear-Microscope 
(see  p.  710) ;  Hartnack's  Polarizing  Apparatus ;  Zeiss's  Micro-Spec- 
troscope (see  p.  703). 

Mr.  O.  Brandt : — Twelve  slides  by  K.  Getschmann,  of  Berlin 
(arranged  Insect  scales,  &c.). 

Mr.  Gilburt : — Six  sections  of  Lathrea  squamaria,  illustrating  his 
paper. 

Dr.  Matthews: — Improved  Turntable  (see  p.  716). 

Messrs.  Parkes  and  Son : — Microscope  Lamp  (see  p.  528). 

Mr.  J.  W.  Stephenson  : — Ampliipleura  pellucida — in  sulphur  dis- 
solved in  bisulphide  of  carbon  ;  Pleurosigma  elongatum — in  phosj)horus 
dissolved  in  bisulphide  of  carbon  ;  Pleurosigma  formosum — in  bisul- , 
phide  of  carbon  alone.     (All  with  Catoptric  Immersion  Illuminator.) 

Mr.  C.  F.  White  :— Microscope  (see  p.  733). 

Zoological  Station  at  Naples : — Twelve  slides,  viz. :  AmpMoxus 
lanceolatus  Yarr. ;  Ascetta  hlanca  H. ;  Aster acanthion  glacialis  0.  F. 
Miiller — Larva  ;  Asterias  glacialis  O.  F.  M. — Gastrula  ;  ditto — Forma- 
tion of  the  Mesoderm ;  Echinocardium  cordatum  Gray — Larva ;  Pyro- 
soma  elegans  Les. — Young  Colony  ;  Pseudodidemnum  Listerianum — Ova 
with  embryo;  Toxopneustes  h-evispinosus  J.  Miiller — Larva,  3rd,  5th, 
and  15th  day ;  Stichopus  regalis  Cuv. — Ovary. 


*  This  is  irrespective  of  the  descriptions  of  Microscopes  previously  figured  in 
foreign  journals,  but  which  not  having  hitherto  appeared  in  any  English  publi- 
cation, are  now  figured  and  described  in  the  Journal  so  as  to  make  the  English 
Eecord  as  complete  as  posaible. 


F^ *^^ 

^  BI-MONTHLY,  ^ 


r  To  Non-Fellows, 


Vol.  ni.  No.  6.]  OCTOBER,  1880.  [    Price  4s. 


Journal 


OF   THE 


Royal 
Microscopical  Society; 

CONTAINING   ITS  TRANSACTIONS  AND   PROCEEDINGS. 

AND  A  RECORD  OK  CURRENT  RE5EARC:iES  RELATrNG  TO 

INVERTEBRATA,   CRYPTOQAMIA, 
MICROSCOPY,  &c. 


EdiUd,  Muier  (he  direction  of  the  Publication  Committee^  by 

FRANK    CRISP,    LL.B,,    B.A.,   F.L.S., 

One  of  the  Secretaries  of  the  Society, 

WITH   THE  ASSISTANCE  CF 

A.  W.  BENNETT,  M.A.,  B.Sc,  J  F.  JEFFIIKY  BELL,  M.A^ 

Lecturer  on  Botany  at  St.  Titomas's  l/osf-iial,  |  rrofessor  pf  CoHtparalive  Anatotry  in  Kim^t  College, 

KNO 

B.  O.  RIDLEY,  B.A.,  F.L.P., 

Of  the  British  Museum, 
FEM.OWS   OF  TlIF,   SOCIRTY, 


WILLIAMS    &    NORGATE, 

%  LONDON   AND  EDINBURGH.  M(?  / 

RINTKO    RV    WM.   CI^WBS    ANO   SONS,   I.IMITIU},]  (srA»:i'OMl   STRHlr    AND   CMABINC    CSOSl. 


(    2    ) 

JOURNAL 

OF   THE 

EOYAL  MICROSCOPICAL  SOCIETY, 

VOL.  III.    No.  S. 


CONTENTS. 

Tkansactions  of  tue  Society —  ,.a,:b 

XX.  On  the  Structure  and  Function  of  the  Scale-Leaves  of 
Lathrea  squamabia.  By  W.  H.  Gilburt,  F.R.M.S.  (Plate 

XVII.)          737 

XXI.  On  Daylight  Illumination  with  the  Plane  Mirror.  An 
Appendix  to  Part  I,  of  the  *'  Theory  of  Illuminating 
Apparatus."  By  tlie  late  Dr..  H.  E.  Fripp,  Ex-off.  F.R.M.S. 

(Figs.  66-70)           742 

XXII.  On  an  Improved  Finder.    By  W.  Webb.     (Figs.  71  and  72)  750 

XXIII.  On  Tollbs'  Interior  Illuminator  for  Opaque  Objects.  By 
William  A.  Rogers,  F.R.M.S. ;  with  Note  by  R.  B.  Tolles, 

F.R.M.S.    (Figs.  73  and  74)         ..          ..          ..          ..  754 

Record     of     Current    Researches    relating    to    Inveutbbkata, 

Cbyptogamia,  Microscopy,  &c.     ..          ..          ..          ..  759 

Zoology. 

Development  of  the  liaJibit 759 

Development  of  the  "  Glomerulus  of  the  Ilead-Kidney^'  in  the  Chick  ..      ..  75.) 

Cellular  Evolution  of  Frotoplcmm     7G0 

Imperfection  of  the  Geological  Record      7G0 

Mollusca  of  the  '  Chdknger '  Expedition 7G1 

Antiquity  of  certain  Subordinnte  Types  of  Fresh-iualer  and  Land  Mollusca  7(J3 

Development  of  the  Digestive  Tract  in  the  Mollusca       7ti3 

Action  of  Poisons  on  the  Cephali'puda     7(i4 

Begeneration  of  the  Head  in  Gastropods 765 

Activity  and  Structure  of  the  Muscles  of  Mollusca  Acepltala 76.5 

Pedal  Glands  of  the  Tellinidx 765 

Anatomy  of  the  Bullidea 766 

Development  of  Teredo        ..      ..      770 

Development  uf  Lingula 772 

Struiure  of  Adeona 773 

New  Genus  of  Polyzoa       774 

Little-hnoxvn  Organ  of  the  Dymenoptera 774 

Honey-hearing  Ants 775 

Stru-ture  of  the  Lampyridx  with  reference  to  thuir  Phosjihurescencc  ..      ..  777 

Influence  of  Temperature  in  producing  Varieties  of  Lepidoiitcra        ..      ..  170 

Protective  Attitude  of  the  Caterpillar  of  the  Lobster  Mutk 780 

Odoriferous  Apparatus  of  Sphinx  ligustrl       7;  0 

Spinning  Organs  (f  Insect  Larvie 781 

Parthenogenesis  in  iJalictus       •  7M1 

Gulls  produced  hy  Aphides        782 


(  y  ) 

Ekoord  of  CtJBRENT  Reskabohes,  &c. — Continued. 

PAOK 

Eyes  and  Brain  of  Cermatia  forceps       783 

New  Work  on  Parasites      784 

New  Galeodida 785 

Antemiary  Gland  of  the  Crustacea 785 

liapidity  of  the    Transmission  of  Motor  Stimuli  along  the  Nerves  of  the 

Lobster 786 

Nervous  System  of  Idotea  entomon 787 

Cymothoidx 787 

Odracoda  of  Scotland        788 

Blind  Crustacean        700 

A7inelids  of  the  Norwegian  North  Sea  Expedition 790 

New  Genus  of  the  Archiannelides      ..      ..      790 

Enchytrfeux  cavifola 792 

Batrai-hobdella  Latusti       793 

The  Chxtognaihn         793 

Disease  produced  by  Anchylostoma  dwidenalis        799 

Organization  and  Development  of  the  Gordii 8U1 

Excretory  System  of  the  Trematoda  and  Cestoda 802 

Development  of  the  Liver  Fluhe        803 

Anatomy  of  the  Nemer tinea        803 

Intestinal  Worms  in  the  Horse 805 

Parasites  of  Helminthes      805 

Bodies  found  on  Meat 800 

Flosciilaria  ornata 806 

Prothelmintlms,  a  new  loio  Vermian  Form      806 

New  Synthetic  Type 807 

Develojjment  of  the  Echinodermata 807 

Echinoderms  of  the  Norwegian  North  Sea  Expedition 808 

Synthetic  Type  of  Ophinrid       809 

Uivmoglobin  in  the  Aquiferous  System  of  an  Echinoderm     810 

Buccal  Skeleton  of  the  Asterida         810 

New  Cretaceous  Comatulm ,      810 

Structure  and  Origin  of  Coral  Reefs  a7id  Islands 810 

New  Mode  of  Reproduction  among  the  Hydroida 812 

Origin  of  the  Generative  Cells  in  the  Uydroida      813 

Occurrence  of  Foreign  Spicules  in  Sponges     813 

Tentaculate,  Suctorial,  and  Flagellate  Infusoria  (P\ates  XVIII.  and  XIX.)  814 

Radiolaria  in  "Diaspro  " 819 

Botany. 

Development  of  the  Embryn-snc 819 

Fertilization  of  Coh.v.a  pendulijlora 822 

Structure  and  Motile  Properties  of  Protoplasm       823 

Structure  of  Sieve-tubes       8'it 

Oiemical  Composition  of  Chlorophyll       ..      825 

Composition  of  Chlorophyll        826 

Division  of  Chloro/jhyll-grains 82G 

Branching  of  Endogenous  Organs  from  the  Mother-organ 826 

Influence  of  Direction  and  Strength  of  Illumination  on  certain  Motile 

Phenomena  in  Plants 827 

Case  of  Apparent  Insectivorism         828 

Prolhallia  of  Ferns 829 

Nou-Sexmd  Reproduction  of  the  Prothullium  of  Ferns  by  means  of  Qcmmx 

or  Conidia      829 

Amphibious  Nature  of  the  Prothallium  of  Polypodiacex       82'.) 

Synopsis  of  the  Speeiesof  h6ete»      j-iJO 

Structure  of  Dunwrliera 8;fl 

Formation  of  the  Sporognnium  of  Arrhidium 8)52 

Transition  of  Female  to  Mule  Organ  in  a  Moss 8IJ3 

Neio  Genera  of  Fungi        833 

Mode  of  Escape  of  the  Spores  from  tfie  Asci  in  Ascomycetes 834 

Fungus-parasites  of  the  Aurantiacex       S'Mi 

Fungi  parasitic  on  Forest-trees          S35 

Witch-broom  of  the  Cherry  ( /'zoascus  Winsncri) 8;$5 


(  4  ) 

Recobd  of  Ccbrent  Reskarohes,  &c. — continued. 

PAGE 

Neto  Vegetable  Structures  from  Coal  and  Anthracite     8;<6 

Classification  of  Bacteriacem 8S7 

Atmospheric  Bacteria 837 

Modification  of  the  Properties  of  Bacillus  anthracis  by  Cultivatioti    ..      ..  838 
Bacterium  foetidum :  an  Organism  associated  with  profuse  Siceating  from 

the  Soles  of  the  Feet      839 

Alcoholic  Fermentation      841 

Clastoderma 8il 

Monograph  of  Arthonia      ..      ..  841 

Algal  Vegetation  of  the  Siberian  Sea-coast       842 

Algse  of  the  Utah  Salt  Lake       843 

Antherozoids  of  Hildebratidtia  rivularis 8l3 

New  Vaucheria 844 

Parasitic  Nostoc 845 

Movement  of  the  Cell-c(yntents  of  Closterium  lunula       845 

Eiidochrome  of  Diatomacess       84G 

MiCEOSCOpy,  &c. 

Microscopical  Analysis  of  Water      847 

Brownian  Movement 849 

Examining  very  soft  BocJis        ..  849 

Lenses  for  Petrographioal  Worh  (Figs.  75  and  7G)       850 

Process  for  Microscopical  Study  of  very  minute  Crystalline  Grains    ..      ..  851 

Br.  Matlhews's  Machine  for  Cutting  Hard  Sections  (Figs.  77-79)      . .      . .  852 

Bleaching  and  WasJting  Sections  (Fii^a.  80  &ud  81)       853 

Wicliersheimer's  Preservative  Liquid       855 

Preserving  the  Colours  of  Tissues 856 

Staiyiing- fluid  for  Amyloid  Substance      857 

Carbolic  Acid  for  Mounting]       858 

WaxCelh 860 

Dry  "  Mounts  "  for  the  Microscope —  Wax  ami  Gutta-percha  Cells      ..      ..  8'Jl 

Covering  Fluid  Mounts      864 

Thickness  of  Cover-glasses 866 

Finishing  Slides 866 

Novel  Form  of  Lens 867 

Swift's  Radial  Traversing  Sabstagc  IllumirMtor  (FifiB,  82  and  8S)    ..      ..  867 

Soimes's'^  Isophotal"  Binocular  Microscope  (Fig3.8i-87) 870 

NacheVs  Microscope  loith  Rotaiing  Foot 873 

Edmunds's  Parabolized  Gas  Slide  and  Nachet's  Gas  Chamber    ..      ..      ..  873 

Advantages  of  the  Binocular  Microscope 874 

Reduction  of  Angle  of  Aperture  tcith  the  Binocular  (F'lga.  88-dl)      .,      ..  874 

Apertures  exceeding  ISO"^  in  Air  (Figs.  d2-di)      875 

Diameter  of  Microscope-tubes 877 

Wythe's  Amplifiers      ..  877 

Foreign  Mechanical  Stages  {F'lgs.  95  and  dG)        878 

''Fine"  Adjudmenls  (Figs.  91  and  98) 882 

Seibert  and  Kraft's  Fine  Adjustmeid  (Figs.  90-101) 883 

Construction  of  Immersion  Objectives  (Fig.  102) 884 

Mountiiig  of  the  Front  Lens  of  Immersion  Objectives 8S4 

Penetration 886 

Tolles's  Improved    Traverse-lens,    Illuminating  and  Aperture-measuring 

Apparatus  (Fig.  103) 887 

Semi-cylinder  Illuminator  (Fig.  101:)       889 

Tlie  Iris  Diaphragm  an  Old  Invention 890 

Microscopical  Goniometer 890 

Pleurosigma  angulatum  as  a  Test  Object 890 

FasoWs  Test  Plate 891 

Giiidher's  Photographs  of  Pleurosigma  angulatum 891 

New  Microscopical  Journal       892 

BlBIJOGBAPHY         ..              ..              ..              ..             ..              ••              ••              ••  893 


JOXTFiN.P.JvIICP.  .SOC:VOL.III.PL.XYn 


W.H.  {h'Jta:>^~t;  ScL  <i'Sj  -Aat, . 


"flwJjSVrmOTvi;  Cd. 


Sca,le-lea--ves  of  LatKi?ea  ec[U8Lm.a,r-ia 


JOURNAL 

OF    TUB 

ROYAL  MICROSCOPICAL   SOCIETY. 

OCTOBER,  1880. 


TKANSACTIONS  OF  THE   SOCIETY. 


XX.  —  On  the  Structure  and  Function  of  the  Scale-Leaves  of 
Lathrea  squaniaria.     By  W.  H.  Gilburt,  F.R.M.S. 
(Read  9th  June,  1880.) 
Plate  XVII. 
Bentham,   ill   describing    the   uuderground    portion    of  this   re- 
markable plant,  says :    "  Eootstock  fleshy  and  creeping,   covered 
with  close-set,  short,  thick,  fleshy  scales."  *     Syme  and  Lankester 
first  describe  it  as  having  subterranean  stems,  and  then  go  on  to 
say,  "  Eootstock  branched,  giving  off  slender  fibres  which  attach 
themselves  by  minute  tubercles  to  the  plant  on  which  it  grows ; " 
and  further  on,  "  The  common  name  of  tliis  plant  was  given  to  it 
from   a   supposed   resemblance  of  the  scaly   roots   to   a   human 
tooth."  t 

That  the  term  "  rootstock  "  is  here  incorrectly  applied  will  I 
think,  be  at  once  apparent,  for  the  following  reasons:  — («)  That 
the  flowering  stem  is  a  direct  continuation  of  axis  of  the  plant ; 
(&)  that  the  scales  with  which  the  underground  portions  are  I'ur- 
nish(  d  ari.so,  as  do  all  leaves,  in  strictly  acropetal  order ;  (c)  and  that 
the  branches  are  produced  from  buds  arising  in  the  axils  of  the.so 
scales.  We  must  therefore  regard  it  not  as  a  rootstock,  but  as  an 
underground  stem ;  and  the  scales,  as  leaves  which  have  undergouo 
modification. 

The  description  given  above  conveys  all  that  need  be  said  of 


EXPLANATION  OF  PLATE  XVII. 

Figs.  1-3.— Sections  of  sciile-loiivcs.    1.  Transverse.    2.  Tang(.ntiiil.    3.  Vortical 
nnd  radial  to  tlio  stem. 
„     4-G. — Ses.'jiio  bUifaoo  glaii(l.-<.      4.  lu    plm.      ;").  Pir-ipcctivo.      G.  0|pti<-al 
BLction  allowing  laign  lia.sal  c<  II,  and  thickening  of  cnp-ccll  walls 
in  anglis. 
„     7,  S. — PedicoUate  glands. 

Figs.  1-3x8;  4-8  X  22.'). 


♦  '  Ilandlmok  nf  niitlHli  Flora,'  vol.  ii.  p.  <'.i)l 
t  'English  P.utaii.v."  vol.  vi.  pp.  ls;i-'.)(i. 
vol..    III. 


788  Transactions  of  the  Society. 

their  outward  aspect ;  but  sections  of  them  exhibit  a  far  more  com- 
plicated structure  than  their  outward  form  would  lead  us  to  expect. 
Figs.  1-3  represent  sections  in  as  many  directions,  No.  1  being 
transverse,  2  tangential,  and  3  longitudinal  and  radial  with  regard 
to  the  stem. 

The  sections  show  that  these  organs  are  so  developed  as  to 
enclose  a  number  of  chambers,  having  communication  externally  at 
their  base.  These  chambers  are  produced  by  the  early,  unequal, 
and  excessive  development  of  what  is  morphologically  the  under 
side  of  the  lamella  of  the  leaf,  the  epidermis  being  continuous  over 
their  entire  inner  surface.  Their  number  and  form  is  very  variable, 
and  they  frequently  communicate  with  each  other. 

The  whole  of  the  inner  surface  of  these  chambers  is  literally 
crowded  with  glands,  of  which  there  are  two  forms, — a  sessile  gland, 
three  views  of  which  are  shown  in  Figs.  4-6,  and  a  pedicellate  gland. 
Figs.  7,  8.  The  first  form  is  composed  of  four  cap-cells  arranged 
parallel  to  each  other,  and  a  large  basal  cell,  which  appears  as  an 
annulus  round  the  cap-cells,  when  the  gland  is  looked  at  in  plan  or 
perspective.  Figs.  4,  5 ;  Fig.  6  being  an  optical  section,  showing 
peculiar  thickenings  of  the  walls  of  the  cap-cells  at  four  out  of  the 
five  angles  formed  by  their  union  with  the  basal  cell.  The  lower 
wall  of  the  latter,  where  it  is  in  contact  with  the  deeper  cells  of  the 
leaf,  exhibits  a  large  number  of  simple  pits,  rendering  it  almost 
sieve-like  in  appearance.  The  other  form  of  gland  has  a  pedicel 
usually  consisting  of  a  single  cell  cut  off  from  the  epidermal  ceil 
from  which  it  originated  by  a  septum,  and  a  glandular  head  of  two 
or  four  cells,  the  cell  plates  which  form  them  being  always  laid 
down  vertically  and  at  right  angles  to  each  other.  Occasionally 
one  of  these  glands  may  be  found  having  a  pedicel  of  two,  three,  or 
four  cells  in  vertical  series,  while  others  have  a  head  of  only  three 
cells,  the  division  of  one  of  the  primary  daughter-cells  being  sup- 
pressed. 

Both  kinds  of  glands  are  filled  with  a  colourless,  hyaline  proto- 
plasm, in  which  usually  a  few  granules  are  included,  frequently 
exhibiting  vigorous  Brownian  movement. 

On  the  surface  of  both  forms  of  glands  in  the  older  scale-leaves 
a  large  number  of  rigid,  rod-like  filaments  are  to  be  seen  standing 
at  right  angles  to  their  surfaces,  the  nature  of  which  I  have  not 
been  able  to  determine.  They  do  not  appear  to  be  protoplasmic  in 
their  character,  as  they  do  not  shrink  under  the  application  of 
alcohol,  and  are  not  continuous  with  the  cell- contents.  In  young 
leaves  they  are  absent.  In  the  older  leaves  the  glands  are  also 
always  found  surrounded  with  an  accumulation  of  flocculent  matter. 

The  vascular  system  of  the  leaves  also  requires  notice.  The 
common  bundles,  upon  entering  the  leaves,  divide  at  once,  their 
primary  branches  passing  up  between  the  chambers,  where  they 


Scale-Leaves  of  Lathrea  squamaria.     By  W.  H.  Gilhurt.     739 

again  divide  and  subdivide,  their  ultimate  divisions  being  composed 
of  spiral  cells  only  in  a  single  series.  These  vascular  twigs  are 
very  numerous,  and  only  separated  from  the  epidermis  and  glands 
of  the  chambers  by  a  single  layer  of  cells,  their  course  being 
parallel  with  that  of  the  chamber- walls. 

Bearing  in  mind  the  conditions  under  which  Lathrea  lives,  viz. 
always  buried  beneath  the  surface  of  the  ground,  often  somewhat 
deeply,  the  question  naturally  suggested  by  an  examination  of  these 
structures  is.  What  is  their  function?  for  it  cannot  be  supposed 
that  organs  so  highly  specialized  should  exist  and  yet  serve  no 
imj)ortant  purpose  in  the  economy  of  the  plant. 

If  a  tangential  section  of  a  leaf  of  a  plant  growing  under  normal 
conditions  be  removed,  it  will  be  found  that  all  the  chambers  are 
filled  with  a  fluid  somewhat  turbid  in  appearance  and  having  a 
most  decided  acid  reaction;  we  may  therefore  conclude  that  at 
least  these  glands  serve  the  purpose  of  secretion,  the  fluid  secreted 
being  discharged  outwardly.  That  this  takes  place  somewhat 
abundantly  may  be  inferred  from  the  fact  that  in  the  bank  from 
which  I  have  taken  my  material,  and  which  is  composed  of  a  light 
friable  loam,  the  soil  immediately  surrounding  the  Lathrea  was 
saturated  with  moisture,  while  all  beside  could  be  crumbled  apart 
with  the  fingers. 

The  probability  that  they  possessed  absorbing  powers  also  sug- 
gested itself,  and  a  large  number  of  experiments  have  been  made  to 
determine  it,  adopting  the  methods  employed  by  Mr.  Darwin  with 
Utricularia,  &c. 

Thus  five  tangential  sections  were  cut  from  the  same  leaf. 
They  were  cut  as  thick  as  could  be  well  examined  under  a  ^-inch 
objective,  so  as  to  have  as  many  glands  under  observation  as  possible. 
The  sections  were  first  placed  under  thin  covers  in  distilled  water 
and  examined  carefully,  when  all  the  glands  were  seen  to  present 
their  normal  appearance.  The  distilled  water  was  then  withdrawn, 
and  under  four  of  the  covers  a  solution  of  carbonate  of  ammonia  in 
the  proportion  of  1  to  400  was  run  in,  and  under  the  other  a  1  per 
cent,  solution  of  cane  sugar. 

After  two  hours  they  were  examined,  and  no  change  was  visible ; 
after  three  and  a  half  hours  a  few  of  the  pediceUate  glands  showed 
decided  contraction  of  the  protoplasm  and  a  slight  increase  of 
granulation  ;  after  twelve  hours  all  these  glands  showed  contraction 
of  their  contents,  more  or  less  ;  and  in  twenty-four  hours,  in  all,  the 
protoplasm  was  greatly  contracted  and  coarsely  granular ;  while  the 
section  ,in  the  sugar  solution  had  only  a  very  few  of  the  glands 
slightly  affected.  The  sessile  surface  glands  and  the  cells  of  the 
epidermis  remained  unaltered,  save  by  the  general  darkening  of 
their  contents  which  invariably  takes  ])lace  when  the  plant  is  cither 
placed  in  water  or  exposed  to  air.     Itepcating  these  experiments 

3  c  2 


740  Transactions  of  the  Society. 

with  otLer  sets  of  sections,  the  results  were  sometimes  less  decided ; 
some  of  the  glands  treated  with  the  carbonate  remaining  unaffected, 
while  a  considerable  number  of  those  iu  the  sugar  solution  showed 
contraction. 

Ammonia-nitrate  and  phosphate  were  also  employed,  of  several 
strengths,  from  1  to  |-  per  cent.,  using  control  solutions  of  cane 
sugar  or  gum-arabic,  and  occasionally  distilled  water  only. 

With  ammonia-nitrate  the  results  were  altogether  negative,  a 
few  of  the  glands  only  being  affected,  and  about  equally  in  all  the 
sections  both  in  the  nitrate  and  control  solutions. 

Ammonia-phosphate  in  a  1  per  cent,  solution  gave  very  decided 
results.  Eight  sections  were  placed  under  covers  and  examined  to 
see  that  the  glands  were  in  their  normal  condition.  Six  of  them 
were  then  irrigated  with  the  ammonia-phosphate  and  two  with  a 
1  per  cent,  solution  of  sugar. 

In  two  hours  a  slight  increase  of  granulation  was  observed  in 
the  pedicellated  glands  of  all  the  sections  iu  the  ammonia-phosphate 
solution. 

In  four  hours  the  protoplasm  was  slightly  shrunken  and  still 
more  granular. 

In  twelve  hours  the  above  features  were  very  decided,  and  the 
protoplasm  much  darker  in  the  j)edicellated  glands  than  elsewhere. 

In  twenty-four  hours  the  protoplasm  was  so  darkened  as  to  be 
quite  opaque. 

In  none  of  the  surface  glands  did  I  find  the  least  alteration. 

The  sections  in  sugar  solution  were  nearly  unaltered,  only  very 
few  of  the  pedicellated  glands  but  retained  their  normal  appearance. 

Other  sets  of  sections  were  placed  in  solutions  in  the  proportion 
of  1  to  200,  400,  800;  and  in  each  case  the  results  seemed  to  point 
in  the  same  direction,  though  the  changes  were  neither  so  rapid 
nor  decided.  In  sections  placed  in  a  1  per  cent,  solution  of  gum- 
arabic,  about  half  the  pedicellated  glands  showed  contraction  and 
granulation,  while  others  placed  in  water,  putrid  with  decaying 
vegetation,  remained  quite  unaltered  after  twenty-four  hours. 
Sections  placed  in  distilled  water,  after  being  first  washed  in  it,  pre- 
served their  normal  appearance  at  the  end  of  tliirty-six  hours ; 
while  others  placed  in  it  direct  from  the  razor  had  about  half  their 
glands  contracted  after  the  lapse  of  twenty-four  hours. 

These  facts,  if  not  amounting  to  an  absolute  demonstration  of 
the  absorbing  function  of  the  pedicellate  glands,  yet  furnish  strong 
presumptive  evidence  in  favour  of  it. 

We  may  also  infer  that  seeing  the  fluid  which  fills  the  leaf 
chambers  is  acid  in  character,  it  must  be  secreted  by  the  leaf ;  and 
as  the  sessile  surface  glands  in  all  the  experiments  made,  remained 
absolutely  unaltered,  we  may  conclude  that  it  is  by  them  that  the 
function   is   performed.      In  all  probability  these  functions,  viz. 


Scale-Leaves  of  Lathrea  squamaria.     By  W.  H.  Oilhurt.     741 

secretion  and  absorption,  take  place  alternately,  as  in  other  plants 
wliere  similar  organs  are  found,  and  similar  secretions  are  poured 
out. 

That  the  purpose  served  by  these  organs  is  of  advantage  to  the 
plant  cannot  for  a  moment  be  doubted,  and  that  it  should  be  in  any 
other  way  than  nutrition  is  difficult  to  suppose ;  and  if  this  be  so, 
we  must  conclude  that  it  is  the  decaying  organic  matter  in  the  soil 
which  is  appropriated  by  the  plant,  being  dissolved  by  the  acid 
solution  so  copiously  poured  out,  as  inorganic  substances  could  not 
be  assimilated  in  the  absence  of  light. 

Of  course  if  this  be  the  case,  Lathrea  must  in  future  be  re- 
garded as  but  partially  parasitic — a  view  which  was,  I  believe,  held 
by  Henfrey,  on  account  of  the  fact  that  it  is  often  found  possessing 
roots.  That  Lathrea  does  sometimes  develop  adventitious  roots 
abundantly  is  without  doubt,  I  having  a  longitudinal  section  of  the 
end  of  a  secondary  stem  about  half  an  inch  in  length,  in  which 
eleven  such  roots  are  shown  in  section.  Whether  these  roots  are  to 
be  regarded  as  such,  functionally,  or  only  as  organs  of  attachment 
to  the  host,  I  am  not  quite  prepared  to  say.  In  a  portion  of  a 
plant  which  I  attempted  to  grow  in  a  garden  pot  independent  of  a 
host — and  in  which  some  amount  of  growth  took  place — a  large 
number  of  thin  and  delicate  roots  were  developed  from  the  inter- 
nodes  of  the  stem  nearest  the  summit.  The  plant,  however, 
perished  during  the  severe  frosts  of  last  winter. 


742  Transactions  of  the  Society. 

XXI. — On  Daylight  Illumination  with  the  Plane  Mirror. 

An  Appendix  to  Part  I.  of  the  "  Theory  of  Illuminating 
Apparatus."  * 

By  the  late  Dr.  H.  E.  Fripp,  Ex.-off.  F.R.M.S. 

(Read  l-ith  January,  1880.) 

In  my  paper  on  the  theory  of  illuminating  apparatus,  published  in 
the  last  volume  of  the  Journal,  I  referred  at  some  length  to  a 
doctrine,  which,  being  well  accredited  by  scientific  men  abroad,  did 
not  occur  to  me  as  a  possible  stumbling-block  to  the  acceptance  of 
arguments  based  thereon,  until  I  learned  how  much  it  was  at 
variance  with  the  teaching  and  belief  of  microscopists  in  this 
country.  It  was,  namely,  contended  that  an  object  placed  on  the 
stage  of  the  Microscope  is  always  and  necessarily  illumined  by  a 
converging  pencil  when  daylight  is  reflected  upon  it  from  the  plane 
mirror.  In  English  handbooks  of  the  Microscope  it  is,  on  the 
contrary,  assumed  without  question  that  the  illuminating  pencil  is 
derived  from  a  parallel  beam  of  rays  incident  on  the  mirror  whether 
plane  or  concave.  Now  since  the  conclusions,  theoretical  and  prac- 
tical, deduced  from  such  widely  opposed  premises  cannot  but  be  as 
contradictory  as  the  premises  themselves,  while,  moreover,  they 
cannot  both  be  true,  it  is  desirable  as  well  as  important,  in  a 
scientific  point  of  view,  that  these  antagonistic  beliefs  should  be 
brought  to  the  final  arbitrement  of  fact.  The  question  is  one  which 
optical  science  is  perfectly  competent  to  determine,  proof  or  dis- 
proof of  either  proposition  being  readily  drawn  from  consideration 
of  first  principles  or  from  experimental  tests.  In  the  hope  that  a 
more  explicit  statement  of  the  rationale  of  "  converging  light "  may 
bring  it  more  fairly  under  the  notice  of  those  who  may  be  disposed 
to  give  this  doctrine  due  attention,  I  now  present  a  short  summary 
of  the  grounds  upon  which  it  rests. 

The  transference  of  light,  in  an  optical  sense,  from  one  point  or 
surface  to  another  is  efiected  either  by  reflection  or  refraction.  And 
in  discussing  the  function  of  the  mirror  our  sole  appeal  is  to  the 
law  of  reflection,  just  as  the  law  of  refraction  would  be  appealed  to 
if  the  action  of  the  various  lenses  of  an  illuminator  were  in  question. 
But  in  connection  with  this  transference  of  light  by  means  of  reflec- 
tor or  refractor  an  interesting  problem  occurs  in  estimating  the 
illuminating  eff'ect  of  the  difierent  surfaces  which  consecutively  take 
the  place  of  the  primary  light  source,  ending  with  the  last  reflecting 
or  refracting  surface  brought  into  action  (as  in  compound  illumina- 
tors). All  that  we  know  of  the  property  of  light  in  rendering 
visible  to  the  eye  material  particles  upon  which  rays  impinge  in 
such  direction  as  to  enter  the  pupil  when  reflected,  and  so  for  the 

*  See  this  Journal,  ii.  (1879)  p.  503. 


Illumination  icith  Plane  Mirror.     By  Dr.  11.  E.  Fripp.    743 

time  render  tliein  virtnally  self-luminous,  strengthens  the  propo- 
sition that  the  illuminating  power  of  any  light-reJSccting  apparatus 
is  measured  hy  the  nunibei-  and  direction  of  rays  which  fall  upon 
the  object  (placed  on  the  Microscope  stage)  from  the  mirror  or  lens 
surface  next  to  it :  and  that  the  specific  intensity  of  the  light  can 
never  he  greater  than  that  of  the  primary  light  source.  This 
problem  is  reduced  to  its  simplest  possible  form  in  the  case  of  the 
plane  mirror.  We  have  but  to  remember  that  each  constituent 
point  of  its  surface  is  independent  of  every  adjacent  point,  so  far  as 
incidence  and  reflection  of  the  light  rays  are  concerned.  And  it 
remains  only  to  discuss  the  right  application  of  the  law  of  reflection 
under  given  circumstances,  and  to  note  that  the  physical  constitu- 
tion of  ordinary  daylight  enables  it  to  fuUil  the  conditions  required 
for  illumination  with  the  plane  mirror. 

It  is  not  denied  that  out  of  a  countless  number  of  rays  im- 
pinging from  all  sides  on  the  surface  of  a  mirror  freely  exposed  to 
daylight,  and  consequently  reflecting  them  on  all  sides  according  to 
their  several  lines  of  incidence,  the  larger  proportion  falls  with 
parallel  incidence.  But  it  is  contended  that  ]iarallel  beams  are 
reflected  as  such,  and — for  that  very  reason — their  component  rays 
do  not  touch  the  object,  but  pass  by  and  outside  of  it.  It  is  further 
contended  that  every  ray  which  docs  reach  the  object  must  approach 
from  without  in  a  direction  determined  by  the  position  of  the  point 
or  surface-element  of  the  mirror  where  the  reflection  takes  place ; 
that  is  to  say,  on  the  relation  of  this  position  to  the  object  on  one 
side  and  the  light  source  on  the  other. 

The  demonstration  of  these  points  is  offered  in  the  accompanying 
diagrams. 

It  will  be  granted  that  obliquity  of  incidence  must  always  give 
rise  to  obliquity  of  rejlection. 

Further,  it  will  appear  from  consideration  of  the  relative  posi- 
tion of  object,  mirror,  and  light  source  (due  to  mechanical  arrange- 
ment of  the  Microscope),  that  light  must  always  fall  obliquely  on 
the  mirror  in  order  to  strike  the  object,  whatever  be  the  size  or 
inclination  of  the  mirror. 

The  problem  of  converging  illumination  is  therefore  demon- 
strated when  it  is  shown  that  rays  incident  upon  constituent 
surface  elements  of  the  mirror  outside  of  its  centre  do  incline,  after 
reflection,  towards  an  axial  line  above  that  centre.  This  axial  lino 
coincides  with  the  axis  of  the  TMicroscope  when  the  mirror  is  set  for 
"central  illumination,"  but  when  the  mirror  is  moved  into  position 
for  oblique  ilhimination,  the  axial  Hnt^  is  also  obli(iuo  and  coincident 
with  an  imagiufiry  lino  drawn  Irom  ecntro  of  the  mirror  to  the 
several  points  of  the  ol)jecton  which  illuminating  })encils  fall.  But 
those  rays  alone  will  reach  the  object  which  full  with  tho  necessary 
incidence  and  reflection. 


744 


Transactions  of  the  Society. 


To  find  this  necessary  direction  I  construct  a  diagram,  in 
wliicli  lines  are  drawn  from  the  object  to  opposite  points  of  the 
mirror  (those  which  indicate  the  extreme  angular  magnitude  of 
pencil  allowed  by  size  and  distance  of  the  mirror  from  the  object 
and  its  inclination  to  the  axis  of  the  Microscope),  and  project 
according  to  the  law  of  reflection  lines  outward  into  space  which 
indicate  the  exact  arc  of  sky  from  which  the  light  should  come. 
Fig.  66  shows  the  lines  1  and  7  including  an  angle  of  30^.  If 
nothing  intervene,  the  Hght  of  that  sky  surface  must  fall  upon  the 
mirror  and  be  reflected  on  0.  The  intermediate  rays  2,  3,  4,  5,  6, 
have  each  their  particular  angle  of  incidence  and  reflection,  and 
form  the  converging  illuminating  pencil,  or  rather  skeleton 
outline  of  it,  since  the  interspaces  are  filled  by  rays  not  indicated. 
(N.B.  The  diagram  shows  and  corrects  the  mistake  of  drawing  in 
Fig.  3,  p.  518,  vol.  ii.).  The  magnitude  of  pencil  is  of  course 
primarily  dependent  upon  the  presence  of  adequate  light  surface, 
but  its  extreme  limit  depends  upon  the  size  of  the  mirror  and  its 
nearness  to  the  object. 

Fig.  66. 

y 


s'L 

/ 

i^~~ 

1 

1 

■ — ^ ________ 

^^^^ 

U 

"4 

-—-z:::^^^ 

^-^> 

r- 

— —             ^^__ 

^^^^^:r^^==^ 

'vr- 

a  b,  mirror :  diameter  =  2^  inch ;  aob,  angle  of  pencil  =  30° ;  o,  object ; 
SHS',  arc  of  sky  surface  which  delivers  light  on  ah,  subtending  angle  of  30°; 
1,  2,  3,  4,  5,  6,  7,  rays  falling  with  variously  oblique  incidence  on  mirror ;  v  o, 
vertical  line  =  axis  of  Microscope ;  H  o',  horizon  line  ;  S  o'  is',  angle  of  30°. 

In  the  next  place,  it  is  to  be  observed  that  parallel  beams  inci- 
dent in  the  direction  of  the  extreme  outside  rays  of  the  illuminating 
pencil  drawn  in  Fig.  66  and  occupying  the  whole  smface  of  the 


Illumination  with  Plane  Mirror.     By  Dr.  H.  E.  Fripp.    745 

mirror  (Fig.  67,  1  p,7  p),  touch  the  object  by  their  outside  ray  only, 
the  remainder  passing  by  on  either  side.  And,  further,  that  a 
parallel  beam  incident  also  upon  the  whole  mirror  surface,  but  at 
right  angles  to  the  axis  of  the  Microscope,  illumines  the  object  by 

Fig.  67. 


l^p,  two  rays  drawn  parallel  with  1  and  7  respectively.  The  parallel  beams 
1  p  and  p  7  occupy  the  mirror  surface,  but  instead  of  being  reflected  on  the 
object,  fall  outside  of  it,  excepting  the  rays  1  and  7. 

.  its  axial  ray  alone,  as  shown  in  Fig.  68.  So  also  if  each  of  the  inter- 
vening lines  (2,  3,  4,  5,  6,  Fig.  66)  represented  the  course  of  as 
many  parallel  beams  occupying  the  whole  mirror  surface  with  the 

Fir,.  G8. 


Piinillcl  beam  incident  on  minor  at  anu'lo  of  4;") "  to  axis  of  Microscope.  Its 
axi;il  ray  alone  fall.s  on  tlie  object.  Witli  dilfereiit  inclination  the  central  ray 
falls  away  fnim  the;  oljjict,  and  the  illnminaliun  becomes  obliinio:  namely,  from 
some  point  of  mirror  snrfaee  more  or  less  distant  from  its  centre.  This  oldiiiuity 
of  direction  does  not  indicate  convergence  of  light,  as  it  comes  from  one  side 
only  at  a  time. 

incidence  belonging  to  each  line  respectively,  it  is  manifest  that 
the  rays  would  fall  on  dilfcrent  surface  elements  of  the  mirror,  and 


746 


Transactions  of  the  Society. 


remaining  parallel  after  reflection,  fail  to  strike  the  object.  In 
fact,  while  those  rays  which  do  fall  with  such  incidence  as  to  be 
reflected  on  the  object,  form  a  converging  pencil  of  given  angular 
magnitude  (e.  g.  30^  in  Fig.  66),  the  several  bundles  of  jparaUel 
rays  falling  from  the  same  area  of  light  source  would  after  reflection 
occupy  a  space  at  the  plane  of  the  object  (see  dotted  hues  in 
Fig.  67)  half  as  large  again  as  the  mirror ;  scarcely  a  suitable  illu- 
mination for  a  microscopic  object ! 

Lastly,  the  illuminating  power  of  diverging  rays,  supposing 
them  to  proceed  from  a  single  point  of  light  source  and  spread 

Fig.  69. 


Fig.  70. 


V  0  axis  of  Microscope,  the  instrument  being  reclined  to  get  the  whole  pencil 
above 'line  of  horizon  ;  ab,  mirror  inclined  at  45°  ;  aob,  angle  of  illuminating 
pencil  =  30°,  subtended  by  S  S',  arc  of  sky ;  A,  axis  of  illuminating  pencil 
reflected  on  o,  object ;  S  b  and  S' «,  outlines  of  cone  reflected  on  object  o 

The  dotted  lines  in  both  diagrams  show  that  no  other  rays  but  S  6  and  b  a 
touch  the  object,  as  the  other  diverging  rays  from  the  points  b  and  b  taUing  witn 
greater  or  less  obliquity  on  the  mirror  surface,  are  reflected  in  directions  more 
and  more  remote  from  the  object. 

over  the  mirror  smiace,  as  in  Figs.  69  and  70,  is  too  slight  and 
moreover  too  scattered  to  add  anything  to  the  total  efi'ect. 

But  it  may  be  (perhaps  fairly)  objected  that  diagrams,  though 


Bluminaiion  ivith  Plane  Mirror.     By  Dr.  H.  E.  Fripp.    747 

useful  in  illustration,  prove  nothing  unless  they  themselves  are 
proved ;  or  that  they  mislead  when  employed  to  demonstrate  phe- 
nomena in  which  the  effects  of  distance  which  cannot  be  repre- 
sented are  main  elements  of  the  question ;  as,  for  example,  where 
it  is  asserted  that  sky  and  cloud  hght  must  by  reason  of  their 
distance  fall  with  parallel  incidence  of  rays.  In  the  discussion  of 
such  a  doctrine  it  is  pertinent  to  inquire  what  that  distance  is,  and 
what  relation  it  bears  to  the  extent  of  luminous  surface  which  can 
be  brought  into  play.  In  regard  to  the  parallelism  of  the  direct 
solar  rays  there  is  of  course  no  question.  But  the  parallelism  of 
that  portion  of  solar  hght  which  goes  to  form  the  firmament  in  our 
own  higher  atmosphere  is  so  completely  broken  up  by  repeated 
refraction  and  reflection  amongst  the  subtle  particles  of  this  higher 
atmosphere,  that  the  rays  which  constitute  our  dayhght  fall  from 
every  point  of  the  visible  heavens  (though  with  greatly  diminished 
intensity).  That  is  to  say,  we  have  at  disposal  a  light  source 
extending  over  180^,  while  the  sun  itself  extends  over  a  visual 
angle  of  but  half  a  degree  !  Being  thus  surrounded  by  an  illimitable 
and  self-luminous  expanse  of  ether  undulations,  the  question  is  no 
longer  of  parallel  rays  only,  but  of  light  emanating  from  an  outer 
circle  above  the  earth  upon  every  point  of  the  earth's  surface. 
And  a  mirror  exposed  to  such  a  luminous  atmosphere  must  both 
receive  and  reflect  from  all  sides,  and  upon  all  sides.  If,  however, 
it  be  placed  under  the  stage  of  a  Microscope,  all  vertical  light  is 
intercepted,  and  there  remains  nothing  but  the  obhque  incidence 
before  referred  to  as  the  starting-point  of  the  theory  of  illumination 
by  converging  light.  But  once  brought  to  this  point  by  the 
consideration  of  general  principles,  we  are  easily  carried  on  by 
appeal  to  the  law  of  reflection,  in  the  demonstration  of  which  a 
geometric  diagram  stands  as  rightful  evidence,  and,  as  it  seems  to 
me  at  least,  affords  indisputable  proof  that  the  doctrine  of  con- 
verging light  truly  applies  to  the  pencil  by  which  the  Microscope 
object  is  illumined. 

The  circumstances  attending  illumination  by  cloud-reflected 
light  differ  greatly  in  detail,  but  not  at  all  in  principle.  That 
portion  of  solar  rays  which  strikes  upon  and  is  reflected  from  the 
cloud  vapour  close  to  the  earth  (in  comparison  with  firmament  or 
sky  light)  retains,  after  reflection,  nearly  the  same  mixture  of  colour 
as  produces  white  light.  But  its  superior  ilhimiiiating  power  is 
due  probably  to  the  near  distance  from  the  earth  at  which  the 
refraction  and  reflection  of  the  solar  rays  begin,  the  reflected  light 
having  but  a  short  distance  to  travel.  Another  result  of  this 
proximity  is  that  the  illumined  portion  of  a  single  cloud  may  cover 
a  considerable  arc  of  sky,  5'  to  20'  or  more.  And  since  tliis  lumi- 
nous expanse  is  frequently  but  a  mile  or  loss  from  the  earth,  rays 
from  extreme  points  of  the  cloud  must  fall  with  obliquity  of  iuci- 


748  Transactions  of  the  Society. 

dence  upon  the  mirror.  It  must  be  borne  in  mind,  however,  that 
the  direction  of  the  reflected  rays  is  influenced  by  mass  and  shape 
of  the  cloud  as  a  whole,  and  that  its  constituent  vapour  particles  do 
not  present  a  continuous  reflecting  surface.  The  numerous  minute 
fields  of  light  and  shade  which  may  be  observed  within  a  compara- 
tively circumscribed  portion  of  cloud  surface  abundantly  prove  the 
actual  inequality  of  reflection. 

From  the  diagrams  it  may  be  gathered  that  one  ray  only  out 
of  each  parallel  beam  occupying  the  mirror  surface  with  a  given 
degree  of  incidence  actually  falls  on  the  object.  And,  further,  that 
the  rays  which  collectively  form  the  illuminating  pencil  are  singled 
out,  so  to  speak,  by  their  fulfilment  of  the  necessary  condition  of 
converging  incidence  from  a  large  area  of  light  source.  A  whole 
cloud  or  pile  of  clouds  may  in  this  way  be  utilized,  though  the 
general  surface  is  so  unequally  bright  that  the  darker  portion  will 
frequently  reduce  the  effect  of  the  brighter  to  below  the  average 
intensity  of  sky  light  around  the  cloud.  Hence  the  concave  mirror 
is  preferred  to  the  plane,  because,  acting  on  a  different  princi2:)le, 
it  collects  the  relatively  small  but  bright  surface  of  sunlit  cloud 
without  diluting  its  intensity  by  including  the  larger  darker 
portion.  But  under  ordinary  circumstances  of  sky  light  illumi- 
nation, the  convergence  of  light  upon  the  plane  mirror  is  not  only 
a  necessary  consequence  of  optical  law,  but  also  the  necessary  condi- 
tion of  an  adequate  illumination.  And  it  follows  that  the  size  of 
the  mirror  and  its  nearness  to  the  stage  are  important  points  in  the 
design  of  a  Microscope,  and  equally  requiring  attention  in  the 
practice  as  in  the  theory  of  illumination. 

It  has  been  already  noted  that  a  cloud  surface  is  not  continuous, 
like  a  mirror  surface,  and  that  its  shape  greatly  influences  the 
direction  of  reflected  rays.  Cloud  light  is,  in  fact,  self-luminous 
in  the  same  sense  that  the  light  of  the  firmament  is  ;  that  is  to  say, 
the  solar  rays,  falling  on  the  cloud,  are  refracted  and  reflected  and 
dispersed  amongst  its  own  vapour  particles.  Consequently  the 
parallel  incidence  of  solar  rays  by  no  means  conditions  parallelism 
or  uniformity  of  the  reflected  rays.  This  character  of  self-lumi- 
nousness  may  be  contrasted  with  reflection  pure  and  simple,  as,  for 
example,  the  dazzling  glare  of  a  window-pane  upon  which  the  sun 
shines.  Nobody  would  interpret  the  reflection  from  a  smooth  glass 
surface  otherwise  than  as  a  simple  transference  of  the  sun's  light 
in  a  new  direction,  nothing  else  being  changed.  The  radiation  of 
sun  rays  is  simply  continued  from  the  surface  (not  self-luminous 
substance)  of  the  window-pane.  The  cloud-reflected  hght  is,  on 
the  other  hand,  a  residual  eflfect,  after  absorption,  refraction,  and 
dispersion  of  the  original  light  rays  have  been  carried  on  in  the 
intervening  cloud  matter  to  such  an  extent  as  to  lower  the  specific 
intensity  of  the  reflected  light  beyond  calculation.     It  caimot  there- 


Illumination  with  Plane  Mirror.     By  Dr.  H.  E.  Frip-p.    749 

fore  be  inferred  from  the  parallelism  of  the  solar  rays  that  cloud  light 
falls  with  parallel  incidence,  as  may  be  affirmed  in  the  case  of  the 
window-pane  which  reflects  direct  sunlight.  Nor  can  the  distance 
of  the  cloud  be  accepted  as  a  sufficient  cause  of  parallel  incidence, 
considering  its  many  degrees  of  expanse,  and  its  actual  nearness  to 
the  earth.  On  the  contrary,  it  is  self-evident  that  the  different 
intensity  of  light  reflected  from  a  cloud  at,  say,  half  a  mile  or  three 
miles  distance,  and  its  different  angular  magnitude  at  those  dis- 
tances, are  infinitely  more  important  elements  in  the  calculation  of 
illuminating  effect  than  the  hypothesis  of  parallel  incidence.  lu 
fact,  the  inconstant  distance  of  the  cloud  is  in  itself  a  practical 
refutation  of  the  idea  that  such  a  cloud  surface  has  a  constant 
illuminating  power  or  conditions  an  invariably  parallel  incidence 
of  reflected  rays.  Is  it  possible  to  believe,  for  instance,  that 
from  the  widely  spread  extremities  of  a  sunlit  cloud  subtending 
perhaps  20^  of  sky  arc,  and  distant  perhaps  less  than  a  mile,  none 
but  parallel  rays  shall  fall  on  the  mirror  ?  Or — taking  the  meaning 
of  a  parallel  beam  of  light  to  be  that  its  dimensions  are  the  same 
throughout  its  course — is  it  possible  to  accept  the  notion  suggested 
by  sundry  diagrams  in  our  handbooks  that  two  inches  of  sky  or 
cloud  light  are  all  that  natiu'e  offers  for  the  illumination  of  micro- 
scopic objects,  and  all  that  the  plane  or  concave  mirror  is  capable  of 
reflecting  ? 


750 


Transactions  of  the  Society. 


XXII. — On  an  Improved  Finder.     By  W.  Webb. 
(Bead  Uth  April,  1880.) 

The  finder  wliicli  I  bring  before  the  Society  this  evening  consists 
of  a  square  having  sides  of  f  inch,  and  divided  into  22,500  smaller 
squares  with  sides  the  -^ho  of  an  inch  (enclosing  a  space  therefore 
equal  to  the  toftt^  of  an  inch),  being  20,000  more  squares  than 
the  Maltwood  finder,  which  is  an  inch  square.  The  lines  are  ruled 
by  a  diamond  upon  the  under  side  of  the  thin  cover-glass  (for 
better  use  with  higher  powers),  and  are  filled  in  with  black,  the 
field  being  transparent. 

One  square  of  the  Maltwood  finder  more  than  covers  the  field 
with  a  ^-inch  objective  and  A  eye-piece,  all  the  corners  of  the  squares 
being  out  of  the  field ;  but  in  the  new  finder  there  are  sixteen 
squares  in  the  same  space  as  one  in  the  other. 

Fig.  71. 


"— 1 

r 

X 

" 

" 

^ 

^ 

" 

^ 

■ 

" 

""1 

"' 

" 

H 

1 

■^ 

1 

With  some  of  the  higher  powers,  it  is  not  incorrect  to  say  that 
it  is  absolutely  impossible  to  use  the  ordinary  finder,  because  (1) 
being  a  photograph  an  inch  on  each  side,  it  is  necessarily  so  very 
coarse  that  when  used  with  the  high  powers  the  image  as  a  whole 
is  destroyed  in  consequence  of  the  separation  of  its  component 
grains  of  silver ;  and  (2)  all  specific  trace  of  locality  is  absolutely 
lost  by  the  great  size  of  the  squares. 


On  an  Improved  Finder.     By  W.  Wehh.  751 

To  number  the  squares  from  1  to  22,500  would  require  more 
than  100,000  figures,  which  renders  numbering  impossible ;  the 
squares  are  therefore  plotted  in  blocks  of  100,  the  boundary  lines 
of  each  block  of  100  squares  being  cut  deeper,  broader,  and  blacker 
than  the  inner  ones  (excepting  four  lines  which  I  will  describe 
presently),  each  block  consisting  of  ten  rows  of  squares,  and  each 
row  containing  ten  squares.  Each  block  of  100  squares  is  inter- 
sected vertically  and  horizontally  at  its  fifth  divisions  by  lines  less 
black  than  those  forming  the  boundaries  of  the  blocks  of  100  squares, 
but  still  appreciably  blacker  and  broader  tban  the  inner  lines,  thus 
subdividing  the  blocks  into  four  minor  ones,  each  having  five  rows 
with  five  squares  in  each  row,  the  clear  distinction  between  the 
three  kinds  of  lines  commanding  ready  and  unmistakable  recog- 
nition. 

To  reduce  the  finder  to  its  greatest  simplicity  in  working  over 
the  three-quarters  of  an  inch,  1  have  introduced  the  four  special 
lines  above  referred  to,  they  being  broader  than  all  the  others,  and 
two  of  them  embracing  two  sides  of  every  eighth  block  of  100 
squares  from  the  top  to  the  bottom  of  the  finder,  and  the  other 
two  lines  embracing  two  sides  of  every  eighth  block  of  100  squares 
from  the  left  to  the  right,  the  four  lines  thus  forming  the 
boundaries  of  the  central  hlock  of  100  squares,  and  the  inter- 
section of  the  two  lines  which  divide  that  block  into  smaller  blocks 
of  25  squares  is  the  central  point  of  the  finder,  from  which  the  eye 
has  only  to  traverse  tbrough  75  squares  vertically  or  horizontally 
to  locate  any  square  wanted 

Fig.  71  represents  a  little  more  than  the  top  left-hand  quarter 
of  the  finder  (the  finest  divisions  not  being  however  shown).  It 
exhibits  the  central  intersecting  point  of  the  finder,  giving  out- 
side the  broad  lines  7  blocks  of  100  squares  each  vcrticallj  and  7 
horizontally. 

Fig.  72  is  an  enlarged  view  of  one  of  the  blocks  of  100  squares, 
with  the  addition  of  the  Hnest  lines  forming  those  squares. 

It  will  be  readily  seen,  by  looking  at  these  two  figures,  that  from 
the  centre  of  the  finder  the  whole  of  the  22,500  squares  can  be 
easily  found  by  traversing  at  the  very  most  75  small  squares  from 
the  centre,  with  the  same  ease  and  certainty  as  the  eye  traverses  the 
long  and  short  lines  of  the  eye-piece  micrometer,  the  breadth  of  tho 
line  in  the  finder  being  as  easily  distinguishable  as  tho  length  in  tho 
eye-piece  micrometer.  'J'he  square  having  one  dot  in  Fig.  72, 
(assuming  that  figure  to  show  the  central  block  of  the  finder),  would 
be  one  square  on  the  left  of  and  ahove  tho  centre,  to  bo  marked 
"  1  1.  a." ;  the  square  with  two  dots  would  lie  the  second  square 
horizontally  and  vertically  to  the  left  of  and  ahove  the  centre,  to  Ix) 
marked  "  2  h.  2  v.  1.  a." ;  tho  square  with  three  dots  would  bo 
tho  fourth  horizontally  and    tho  third  vertically,  to   be   marked 


752 


Transactions  of  the  Society. 


"4  h.  3  V.  1.  a."  •  and  the  corner  square  with  four  dots  would  be 
the  fifth  horizontally  and  fifth  vertically,  to  be  marked  "  5  h.  5  v.  1.  a." 
All  the  above-mentioned  markings  apply  to  the  other  three  quarters 
of  the  central  block,  with  the  exception  that  the  left  above  becomes 


Fig.  72. 


::|      I — 

~  I 

; 

0 


left  below,  or  right  above,  or  right  below,  of  course  always  counting 
from  the  centre ;  for  instance,  the  square  marked  with  a  O  near 
the  lower  right-hand  corner  being  the  fifth  horizontally  and  fourth 
vertically  to  the  right  and  below  the  centre,  to  be  marked 
"  5  h.  4  V.  r.  b." 

Having  thus  explained  the  reading  of  the  central  block,we  may 
take  the  one  marked  x  in  Fig.  71,  which  we  will  now  assume 
Fig.  72  to  represent,  the  small  square  with  three  dots  would  be  the 
44th  horizontally  and  43rd  vertically,  or,  44  h.  43  v.  1.  a. 

The  above  expressions  might  be  simplified,  as  Mr.  Crisp  has 
51      4         ,  43  Z 


suggested  to  me,  into 


-^,  and  -— T)   the    numerator  of  the 
or  44 


fraction  always  representing  the  vertical  lines,  and  the  denominator 
the  horizontal  ones,  and  I  and  r  being  placed  in  the  upper  or 
lower  part  of  the  fraction,  according  as  the  upper  or  lower,  right 
or  left,  quadrant  of  the  finder  is  inteuded. 

Travel  sing  the  finder  in  any  direction  from  the  centre,  one 
can  go  through  only  seven  blocks  and  a  haK — being  in  all  only 
seventy-five  squares.  After  counting  the  squares  once  or  twice,  it  is 
wonderful  how  rapidly  the  figures  designating  the  squares  are 
arrived  at ;  and  if  the  foregoing  description  be  clearly  understood 
the  process  is  as  short,  simple,  and  certain  as  it  can  possibly  be 
without  numbered  squares. 


On  an  Imjproved  Finder.     By  W.  Webb.  753 

It  is  not  uncommonly  supposed  that  it  is  impossible  to  use  a 
finder  unless  with  a  movable  stage  and  a  stop,  but  in  the  absence 
of  these  it  is  simply  necessary  to  place  the  thumb,  or  a  finger  of 
the  right  hand,  upon  the  slip  of  glass  carrying  the  object  (when  it 
is  in  the  centre  of  the  field)  to  prevent  it  moving,  and  then  to  place 
the  thumb-nail  of  the  left  hand,  or  another  slip  of  glass,  against  the 
left-hand  edge  of  the  object-slip,  and  hold  it  there  while  the  object 
is  taken  ofi"  the  stage  and  a  finder  is  put  in  its  place  against  the 
thumb-nail  or  shp,  and  read  off  as  above  explained,  and  the 
number  of  the  squares  recorded. 

The  finder  will  also  be  found  very  useful  as  a  stage-plate  for 
the  draughtsman  with  the  camera  lucida. 

If  ruled  upon  disks  for  the  eye-piece  they  are  unique,  as  the 
plotting  and  the  object  are  seen  as  one,  either  with  or  without  the 
camera  lucida  or  neutral  tint  glass. 

The  finders  are  all  ruled  and  mounted  so  mathematically  alike 
as  to  enable  a  slide  to  be  marked  and  sent  to  any  part  of  the  world 
wherever  a  Webb's  finder  may  be. 


VOT.,    Tir. 


754  Transactions  of  the  Society. 

XXIII. — On  Tolles'  Interior  Illuminator  for  Opaque  Objects. 

By  William  A.  Eogees,  F.R.M.S. 

(With  Note  by  K.  B.  Tolles,  F.R.M.S.) 

CRead  10th  June,  1880.) 

The  method  of  obtaining  a  sufficient  illumination  for  opaque 
objects  by  admitting  the  light,  above  the  objective  and  reflecting 
it  down  through  the  lenses  upon  the  object,  is  due  to  Professor 
Hamilton  L.  Smith,  of  Geneva,  New  York. ' 

It  is  described  in  a  general  way  in  the  '  Annual  of  Scientific 
Discovery '  for  1866-7,  page  147,  and  is  generally  known  as 
the  "  vertical  illuminator."  The  more  recent  modifications  in  the 
form  of  its  construction  by  Powell  and  Lealand,  and  by  R.  and 
J.  Beck,  while  adding  perhaps  a  trifle  to  convenience  in  use,  add 
nothing  new  in  principle. 

Two  objections  have  been  urged  against  this  form  of  illumina- 
tor : — 

First,  That  there  is  a  great  loss  of  light  in  the  reflections  from 
the  surfaces  of  the  glass  plate,  and  by  the  diminution  of  the 
aperture  in  the  case  of  the  silvered  mirror. 

Second,  That  observers  generally  find  the  successful  manipula- 
tion of  it  exceedingly  difficult. 

The  second  of  these  objections  may  be  overcome  by  attaching 
the  revolving  mirror  to  an  arm  which  receives  its  motion  through 
a  ball-and-socket  joint,  attached  to  the  outside  of  the  tube,  within 
which  the  mirror  revolves.  The  first  objection  is  to  a  certain 
extent  obviated  also  by  this  device,  since  the  mirror,  being  perfectly 
under  the  control  of  the  observer  by  means  of  the  universal  joint, 
all  the  rays  of  light  which  are  available  can  be  directed  upon  the 
surface  to  be  examined. 

Nevertheless,  even  with  the  modification  of  the  universal 
movement  of  the  mirror,  this  form  of  illuminator  has  not  been 
found  well  adapted  to  the  requirements  of  the  special  problem 
upon  which  the  writer  is  engaged,  viz.  the  comparison  of  standards 
of  length  and  the  investigation  of  their  errors  of  subdivision.  In 
the  examination,  for  example,  of  two  different  metres,  the  illumina- 
tion should  be  the  same  in  kind,  quality,  and  quantity  for  every 
graduation  examined. 

After  having  tried,  as  I  supposed,  every  known  form  of  illumina- 
tion without  success,  I  was  dehghted  to  find  in  Carl's  '  Repertorium 
for  Experimental  Physics '  for  1877,  what  appeared  to  be  a  new 
method  of  meeting  the  difficulties  of  the  problem.  In  volume  xiii. 
page  566,  Professor  Wild  describes  a  vertical  comparator  which 
seems  to  meet  in  an  admirable  way  all  the  difficulties  which  relate 


On  Tolles  Interior  Illuminator.     By  William  A.  Rogers.    755 

to  the  flexure  of  the  bars  upon  which  the  graduations  are  traced. 
In  this  article  he  alludes  briefly  to  the  method  of  illumination 
which  he  adopted,  as  follows  : — 

"  For  central  illumination  of  the  divisions,  small  right-angular 
glass  prisms  are  affixed  in  the  interior  of  the  Microscope  near  the 
objective,  which  are  placed  in  the  ends  of  short  tubes  and  inserted 
through  lateral  openings,  reflecting  the  exterior  light  which  passes 
along  the  axis  of  the  short  tube  vertically  against  the  division, 
being  still  more  controlled  by  the  objective.  This  interior  illumina- 
tion is,  according  to  my  experience,  preferable  to  any  other.  It 
produces  sharp,  well-defined  images  of  the  lines,  and  gives  suffi- 
cient light  even  when  diffused  daylight  falls  upon  the  face  of  the 
prism." 

Immediately  upon  reading  this  description  I  went  to  BIr.  Tolles 
in  order  to  obtain  his  assistance  in  the  construction  of  an  illumina- 
tor of  this  form,  being  ignorant  of  the  fact  that  he  had  as  early  as 
1866  made  one  of  exactly  the  same  form.  Inasmuch  as  at  least 
four  persons  seem  to  have  independently  suggested  the  use  of  a 
prism  inserted  between  the  two  lenses  of  the  objective  for  the 
purpose  of  securing  illumination,  it  is  well  to  insert  here  what  I 
believe  to  be  the  first  published  account  of  the  invention.  I  quote 
from  the  '  Annual  ot  Scientific  Discovery  '  for  1866-7,  page 
149:— 

"  Mr.  Charles  Stodder  exhibited  before  the  Massachusetts 
Institute  of  Technology,  in  December  1866,  a  new  illuminator  of 
opaque  microscopic  objects  under  high  powers,  the  objective  being 
its  own  condenser — the  invention  of  Mr.  Tolles. 

"  The  principal  difficulty  met  with  in  passing  a  beam  of  light 
down  through  the  objective  of  a  Microscope,  and  thus  condensing  a 
strong  hght  upon  an  opaque  object,  is,  in  the  case  of  high  powers 
especially,  the  reflection  back  of  a  considerable  portion  hy  the 
lenses  of  the  objective.  This  causes  fog  and  obscuration  of  the 
image,  though  the  object  be  well  illuminated.  This  reflection 
takes  place  principally  at  the  interior  front  surface  of  the  front 
system. 

"  To  obviate  this  difficulty,  a  small  rectangular  prism,  immedi- 
ately above  the  front  system,  is  so  far  introduced  iuto  the  side  of 
the  objective  mounting  as  to  slightly  encroach  upon  the  extreme 
margin  of  the  upper  surface  of  the  combination,  "When  the 
parallel  rays  are  reflected  by  this  prism  down  through  the 
marginal  parts  of  the  front  covered  by  it,  they  will  have  their 
focus  much  beyond  the  place  of  the  object.  As  a  medium  case  tlie 
distance  of  their  convergence  wodld  be  ten  times  the  local  distance 
of  the  objective ;  consequently  a  much  greater  portion  of  the  whole 
light  incident  upon  the  front  system  would  lie  transmitted,  and 
whatever   amount  experienced  reflection  would  be  dissipated  liy 

:;  1)  2 


756  Transactions  of  the  Society. 

travelling  back  through  the  objective  in  a  path  widely  different 
from  that  of  the  visual  pencil." 

During  a  recent  visit  to  the  Conservatoire  des  Arts  et  Metiers 
at  Paris,  I  saw  the  device  here  described,  attached  to  the  Micro- 
scopes of  the  comparator,  with  which  the  operations  of  the  French 
Section  of  the  International  Bureau  of  Weights  and  Measures  are 
conducted.  Its  introduction  is  due  to  M.  Tresca,  who  has  used  it 
since  1871.  It  is  possible  that  the  invention  by  M.  Tresca  may 
have  been  prior  to  this  date. 

Subsequently,  during  a  visit  to  the  establishment  of  Troughton 
and  Simms,  at  Charlton,  I  mentioned  to  31  r.  Simms  that  I  had 
made  use  of  this  form  of  illumination  in  the  Microscopes  of 
the  meridian  circle  of  Harvard  College  Observatory,  thereby 
securing  far  better  definition  and  nearly  ten  times  the  magnifying 
power.  After  a  moment's  search  Mr.  Simms  produced  an  illumi- 
nator of  exactly  the  form  described  by  Mr.  Tolles  and  by  Professor 
Wild,  which  he  had  constructed  as  early  as  1869,  at  the  instance 
of  Mr,  Warner,  a  retired  gentleman  residing  at  Sussex  Place, 
Brighton. 

According  to  the  present  evidence,  the  priority  of  publication, 
and,  I  believe,  of  invention  also,  must  be  assigned  to  Mr.  Tolles. 
Without  doubt  M.  Tresca  was  the  first  to  make  an  actual  use  of 
this  method  of  illumination  in  exact  measurements. 

The  objective  of  which  a  sectional  view  is  given  in  Fig.  73,  was 
made  for  me  by  Mr.  Tolles,  with  special  reference  to  its  adapta- 
tion to  the  examination  of  the  divisions  of  the  copper- platinum 
metre  of  the  X  form  which  M.  Tresca  did  me  the  kindness 
to  trace.  It  has  an  aperture  of  30°  and  a  focal  power  of  1  inch. 
The  front  system  of  lenses  is  at  A.  The  back  system  is  at 
B.  A  rectangular  prism,  whose  surfaces  c,  d,  e,  are  ground  and 
polished,  is  shown  entering  one  side  of  the  mounting,  immediately 
above  the  front  lens.  Parallel  rays  of  light  entering  at  c  pass  into 
the  prism,  are  reflected  from  d,  emerge  at  e,  impinge  upon  the 
front  lens  A,  and  have  their  principal  focus  at  F ;  the  focus  of  the 
objective  being  at  F',  where  the  object  is  seen.  The  light  having 
its  focus  at  F  is  better  distributed  on  account  of  the  greater 
breadth  of  the  pencil  at  F'.  It  might  be  sui)posed  that  if  a  con- 
denser were  applied  to  the  prism,  the  light  thereby  being  brought 
to  a  focus  at  F',  a  better  illumination  would  be  secured.  In  actual 
experience,  Mr.  Tolles  has  found  that  this  is  not  the  case. 

The  prism  is  held  in  place  by  a  spiral  spring  pressing  upon  a 
ring  which  fits  rather  loosely  upon  the  tube.  By  means  of  the 
screw  at  /  any  required  inclination  can  be  given  to  the  prism.  The 
field  of  illumination  can  be  regulated  by  pushing  in  or  withdrawing 
the  prism.  When  it  is  entirely  withdrawn,  the  objective  takes  the 
ordinary  form. 


On  Tones'  Interior  Illuminator.    Bij  William  A.  Bogers.     751 


I  will  close  this 


Fig.  73. 


I  find  the  prism  useful  in  supplementing  the  light  from  the 
mirror  below,  when  an  intense  illumination  is  desired  with  trans- 
parent objects.  This  method  of  illumination  seems  to  be  rather 
better  adapted  to  high  than  to  low  powers.  I  have  a  ^  with 
which  the  most  perfect  illumination  of  graduated  metal  surfaces 
can  be  obtained  by  simply  turning  the  face  of  the  prism  towards 
a  window.  This  method  seems  well  adapted  also  to  the  resolu- 
tion of  bands  of  fine  lines.  If  the  lines  are  ruled  on  cover- 
glass,  and  are  covered  with  a  thin  coating  of  either  silver,  gold,  or 
platinum  by  the  method  of  Professor  Wright,  of  Yale  College,  the 
resolution  will  be  efiected  about  as  well  by  looking  at  the  lines 
through  the  coating  as  by  viewing  them  by  reflection. 

The  method  of  illumination  here  described   has    an   especial 
interest  in  connection  with  immersion  objectives. 
article  with  a  communication  with  which  Mr. 
Tolles  has  kindly  furnished  me,  together  with 
the  sketches  shown  in  Figs.  73  and  74. 

"  With  immersion  objectives  the  illumi- 
nator-front has  still  more  efiective  and  extended 
application : — 

First,  Because  more  of  the  front  lens  can 
be  brought  into  use  for  the  purpose  of  illumi- 
nation than  with  dry  objectives. 

Second,  Because  any  possible  glare  arising 
from  the  marginal  zone  of  total  reflection  in 
the  dry  objective,  has  no  existence  when  the 
front  has  water  contact  with  the  covering 
glass.     This  is  strictly  true  in  the  case  of  the  ';/ 

prism,  while  it  might  not  be  true  in  the  case  of  r 

a  transparent  disk  of  glass,  placed  as  a  reflector 
at  the  back  of  the  entire  objective  system,  and  covering  its  entire 
aperture.  Eeflection  from  a  disk  might  easily  reach  an  outside  zone 
of  total  reflection  even  with  a  water-immersion  front,  and  give  back 
stray  rays  which  would  cloud  the  view,  but  the  prism  would  neces- 
sarily stop  all  rays  not  contributing  to  the  formation  of  the  image, 
even  without  the  interposition  of  diaphragms.  In  the  case  of  bands 
of  lines,  as  in  Nobcrt's  plates,  there  would  be  for  the  most  part 
exemption  from  glare,  and  the  whole  interior  aperture  of  the 
objective  would  bo  brought  into  use,  except  that  portion  which  is 
stopped  by  the  prism.  •  The  angle  of  this  interior  aperture  would 
be  bounded  i7i  a  homogeneous  immersion  medium  by  the  extreme 
rays  utilized  by  the  objective. 

Fig.  74  represents  the  front  duplex  system  of  the  immersion 
■J-inch  objective  made  for  Mr.  Crisp  in  1873.  Jt  is  one  of  the  very 
first  made  to  demonstrate  the  practicability  and  the  utility  of  the 
outside — '  cxtru-limital ' — immersion  aperture.      It  has  an  cxcep- 


758 


Transactions  of  the  Society. 


tionally  small  front  leus,  but  it  will  serve  to  show  the  convenient 
ajoplication  of  the  prism  to  objectives  of  this  class. 

The  rays  a  and  h  in  Fig.  74,  as  traced  by  Professor  Keith,  show 
an  angle  of  110°,  or  55°  on  each  side  of  the  axis.     Eays,  whether 


Fig.  74. 


fl> 

I 

fd 

~~^ 

. 

kz 

z>\ 

\ 

/ 

^ 

^ 

"^ 

parallel  or  divergent,  entering  the  prism  at  c,  would  take  the  same 
general  direction  as  the  rays  a  and  6,  but  their  focal  distance  would 
be  about  thrice  that  of  the  entire  objective.  If  the  seat  of  the 
prism,  as  shown  in  Fig.  73,  is  in  a  plane  at  right  angles  to  the 
optical  axis,  then  the  direction  of  the  illuminating  ray  can  be  con- 
siderably controlled  by  raising  or  lowering  the  outer  end  of  the 
prism  by  means  of  the  screw  at  /,  and  the  reacting  spiral  spring 
above." 


(  75t)  ) 
EECORD 

OF  CURRENT  BESEABCHES  RELATING  TO 

INVERTEBRATA,  CRYPTOGAMIA,  MICROSCOPY,  &c.* 


ZOOLOGY. 


A.     GENEHAL,  including  Embryology  and  Histology 
of  the  Vertebrata. 

Development  of  the  Rabbit. t — The  recent  observations  of  Pro- 
fessor Kulliker  have  shown  him  that  on  the  fifth  clay  the  area  cmbryo- 
nalis  of  the  rabbit  is  made  up  of  three  layers ;  these  are 

(a)  The  cells  of  the  investing  layer  of  Rauber,  which  are  flat  and 
large  and  are  part  of  the  primitive  unilaminate  germinal 
vesicle. 

(h)  A  layer  of  flattened,  pretty  thick,  small  cells,  which  he  (as 
also  Rauber)  regard  as  ectodermal,  while  Edouard  van 
Beneden  looks  upon  them  as  forming  the  mesoderm. 

(c)  The  cells  of  the  endoderm  are  flat  and  large. 

He  fiuds  tbat  the  investing  cells  of  Rauber  are  temporary  struc- 
tures wLich  have  no  relation  to  the  formation  of  the  ectoderm  ;  this 
is,  of  course,  in  express  opposition  to  the  view  of  their  future  which  is 
taken  by  Van  Beneden,  but  it  is  one  on  which  the  learned  German 
embryologist  speaks  very  confidently ;  nor  is  this  all,  the  mesoderm 
is  stated  not  to  aj)pear  till  the  time  when  the  primitive  stripe  begins 
to  be  formed  ;  when  it  docs  begin  it  takes  all  its  origin  from  a  thicken- 
ing of  the  ectoderm,  and  has  no  relations  to  the  endoderm. 

The  demonstration  of  the  presence  of  a  number  of  pieces  of  nuclei 
and  cells  in  the  young  embryos,  and  their  jn-esence  in  number  in  tlio 
structures  which  are  undergoing  conversion,  seem  to  show  that  at 
these  stages  the  chief  part  is  played  by  the  growth  of  the  cells,  and 
not  by  any  mechanical  causes.  The  author  promises  further  details 
shortly. 

Development  of  the  "  Glomerulus  of  the  Head-Kidney"  in  the 
Chick.J — This  structure  has  been  already  noted  by  Mr.  Adam  Sedg- 
wick and  Mr.  Balfour,  and  Gasser  has  arrived  at  similar  conclusions 
as  to  the  characters  of  the  structure.  In  the  i)rcvious  communication 
no  definite  answer  was  given  to  the  point  as  to  whether  this  glome- 
rulus was  a  "  continuous  structure."  A  study  of  its  development  lias 
since  shown  Mr.  Sedgwick  that  it  is  not  so,  but  that  the  external 
glomerulus  or  glomerillus  of  the  head-kidney  of  the  chick  consists 

*  cS^T  It  should  lie  understood  tliat  (he  Society  do  not  liold  tliemselves  respoii- 
sihle  for  tlic  views  of  the  luithora  of  the  jiapers,  &e.,  referred  to,  nor  for  the  umuner 
in  which  those  views  may  be  expressed,  the  object  of  tiie  Record  being  to  present 
II  siiniiuiiry  of  the  puj'ers  'is  actttal/i/  puhlislied.  Objections  and  corrcctious  should 
tiirrefore,  for  tlu-  nitjst  part,  be  addressed  to  the  autiiors'. 

t  'Zool.  Anzeig.,'  iii.  (I8«U)  j).  :J70. 

t  '  Quart.  Jouru.  Mier.  Sci.,'  xx.  (1880)  p.  372. 


760  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

really  of  a  "  series  of  glomeruli  of  primary  Malpigliian  bodies  pro- 
jecting through  the  wide  openings  of  the  segmental  tubes  into  the 
body  cavity."  These  structures  seem  to  be  found  between  the  ninth 
and  thirteenth  segments,  but  the  corresponding  primary  segmental 
tubes  are  never  fully  developed  in  the  chick. 

Further  details  (with  figures)  of  this  extraordinary  and  unexpected 
development  are  promised. 

Cellular  Evolution  of  Protoplasm,* — M.  Bordone,  in  a  "  thesis  " 
under  this  title,  commences  with  amorphous  protoplasm  as  the  sim- 
plest form  of  matter  capable  of  containing  life ;  its  first  stage  in 
upward  development  is  the  leucocyte,  which  may  arise,  though  rarely, 
in  the  tissues  without  origin  from  a  cell.  It  then  acquires  a  nucleus, 
and  in  this  condition  may  form  protoplasmic  leucocytes  by  gemma- 
tion. This  appears  to  be  proved  by  the  separation  from  mulberry- 
like masses  in  the  blood  of  the  Axolotl  of  granules  which  fuse  together 
and  grow  by  taking  in  foreign  material.  This  division  is  preceded  by 
multiplication  of  the  nucleus,  which  occurs  either  by  fission  or  bud- 
ding, while  in  exceptional  cases  new  nuclei  may  arise  independently 
in  the  protoplasm  ;  budding  fission,  or  segmentation  then  operates  to 
multiply  the  cell. 

Imperfection  of  the  Geological  Record,  t — Herr  Fuchs  contends 
that  were  the  chronicles  of  past  ages  so  imperfectly  kept  by  the  rocks 
as  Mr.  Darwin  and  his  followers  maintain,  the  study  of  palaeontology 
would  have  an  interest  merely  for  curiosity  collectors.  On  the  con- 
trary, the  data  already  obtained  from  its  study  are  so  full  as  to  afford 
a  firm  basis  for  the  discussion  even  of  such  general  questions  as  the 
Darwinian  theory.  Thus,  the  whole  series  of  organisms  may  be 
divided  into  two  groups,  (1)  one  consisting  of  such  as,  owing  to  their 
peculiar  habits,  or  to  the  soft  consistency  of  their  bodies,  could  only 
be  exceptionally  preserved  as  fossils  (e.  g.  Medusas,  Ascidians,  insects, 
birds,  soft  plants)  ;  (2)  the  second  of  those  whose  form,  skeleton,  and 
manner  of  life  tend  to  their  preservation  (corals,  &c.).  These  latter 
are  preserved  not  as  the  consequence  of  chance,  but  in  the  natural 
course  of  the  formation  of  sedimentary  strata.  How  certainly  their 
survival  is  owing  to  these  conditions  is  shown  by  the  discovery  of  a 
richly  fossiliferous  marl  in  digging  the  foundations  of  the  Messina 
Docks ;  of  the  fossil  shells  found,  about  one  hundred  were  known  as 
living  species,  a  few  were  not  so  known ;  these  few,  however,  in  time 
were  added  to  the  recent  fauna  by  dredgings  made  in  the  Bay.  Of 
337  species  of  testaceous  Mollusca  found  in  the  sea  on  the  west  of  Italy, 
300  are  known  to  occur  in  neighbouring  quaternary  deposits.  Com- 
paring the  richness  in  species  of  the  most  abundant  recent  molluscan 
fauna,  that  of  the  Philippine  Islands,  with  that  of  the  European 
upper  chalk,  or  of  the  Bohemian  Silurian  basin,  the  two  latter  lose 
little  by  the  comparison.  All  the  indigenous  European  Ungulates  are 
known  in  the  fossil  state.     If  such  can  be  shown  to  be  the  case  with 

*  See  '  Eev.  Sci.  Nat.,  ii.  (1880)  p.  115. 

t  '  Verb.  k.-k.  Geol.  Keichsanstalt,'  xxix.  (1879)  p.  355  ;  xxx.  (1880)  pp.  39,  61. 
See  also  'Nature,'  xxi.  (1880)  p.  476. 


INVEKTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  761 

tlie  many  groups  taken  as  examples,  then  the  Darwinian  theory  must 
be  demonstrable,  if  at  all,  from  the  evidence  thus  afforded. 

Direct  contradiction  is  also  given  to  the  evolutionist  doctrines  by 
the  fact  of  the  periodicity  of  the  development  of  animal  life  which 
is  seen  to  have  been  the  rule  in  past  times  :  i.  e.  epochs  of  active  deve- 
lopment were  succeeded  by  times  of  comparative  rest,  and  the  develop- 
ment itself  varied  in  intensity.  It  is  contrary  to  the  analogies  afforded 
by  the  j)resent  order  of  things  to  suppose  this  to  be  due  to  changes  in 
the  external  conditions,  for  these  may  cause  redistribution  but  not 
transmutation  of  plants  and  animals.  Again,  the  relation  of  the 
faunae  and  floras  of  consecutive  geological  periods  to  each  other  shows 
a  co-ordination  closely  resembling  that  of  those  of  neighbouring  dis- 
tricts at  the  present  time,  in  having  a  number  of  species  in  common, 
a  nimiber  of  decidedly  different  ones,  and  a  small  number  of  forms 
differing  scarcely  more  than  as  varieties  from  some  belonging  to  both 
districts. 

If  this  relation  is  sought  to  be  explained  by  the  missing  species 
yet  to  be  discovered,  it  may  be  replied  that  if  investigation  succeeds 
in  finding  in  one  formation  the  (e.  g.)  50  representative  species  neces- 
sary to  show  its  absolute  sequence  upon  the  preceding  formation,  it  is 
as  likely  also  to  find  (e.  g.)  500  more  species  in  that  formation,  and 
thus  set  theorists  again  to  work  to  find  these  species  also  in  the  beds 
following.  The  asserted  completion  of  the  organic  series  by  fossil 
links  is  unfounded,  for  though,  as  in  the  Ungulata,  many  gaps  are 
thus  filled  up  (by  Anchitherium,  &c.),  yet  as  many  more  are  created 
by  the  discovery  of  wholly  new  types  (as  Brontotherium,  &c.) ;  so 
with  the  mesozoic  reptiles  and  fish  and  Cephalopoda,  and  still  more 
with  the  palaeozoic  fauna  ;  in  particular,  Professor  Claus's  declaration 
(in  a  lecture  at  Vienna  in  1876)  of  the  surprisingly  small  help 
which  he  has  derived  from  the  fossil  forms  in  making  out  the  genea- 
logy of  the  Crustacea,  is  brouglit  forward  in  support.  The  number 
of  its  zones  of  life  must  be  taken  into  account  in  reckoning  the 
changes  undergone  by  organisms  in  any  geological  period ;  for 
instance,  153  zones  are  distinguished  from  the  Silurian  to  the  present 
age,  and  33  in  the  Jurassic  rocks,  the  passage  from  each  zone  giving 
the  necessary  conditions  for  mutation  of  a  species ;  but  taking  the 
actual  number  of  such  changes  observed  in  the  case  of  the  Cephalo- 
poda (a  highly  modifiable  group),  in  passing  through  the  Jurassic 
rocks,  viz.  77,  the  conclusion  is  drawn  that  on  an  average  only 
24  periods  of  change  can  actually  have  occurred  for  any  group  of 
animals  since  the  Silurian  times,  a  number  quite  insufficient  to 
account  for  the  immcuso  (asserted)  development  of  new  genera, 
families,  orders,  and  classes  since  that  time. 

B.  INVERTEBRATA. 

Mollusca. 
Mollusca  of  the  'Challenger'   Expedition.*— The  Rev.  R.  B. 
Watson   gives  the   following  as  a  few  points  which  stand   out  with 
Bpecial  prominonco  as  the  result  of  his  study  of  this  material 
*  '  Jouiu.  Liuii.  Soc'  (Zool.),  xv.  (1880),  p.  87. 


762  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

"  1.  Depth  is  an  important  condition  of  molluscan  life.  That  is 
to  say,  there  really  are  shallow  and  deej)  water  species  and  genera, 
though  their  bathymetric  limits  are  not  absolutely  constant. 

To  some  this  may  seem  too  self-evident  and  universally  accepted 
a  proposition  to  need  statement.  Such  would  have  been  the  case 
some  years  ago,  but  dredgings  from  the  deep  sea  have  presented  facts 
which  demanded  a  revisal  of  received  opinions  on  this  point ;  and 
while  the  result  in  the  main  cannot  be  said  ever  to  have  been 
doubtful,  and  while  the  evidence  of  other  branches  of  natural 
history  has  already  been  obtained  in  this  same  sense,  it  is  desirable 
also  to  record  the  witness  of  the  MoUusca  of  the  '  Challenger ' 
Expedition. 

2.  Temperature,  even  more  than  mere  depth,  seems  an  important 
condition  in  molluscan  life. 

It  is  needless  to  speak  here  of  other  conditions,  such  as  light,  or 
food,  or  oxygen,  because,  though  there  are  extreme  differences  in  these 
respects,  and  though  their  influence  must  be  very  great,  still  their 
precise  amount,  and  the  nature  and  direction  of  their  effects,  are  too 
little  known  to  afford  foundation  for  more  than  guessing. 

Pressure  seemed  likely  to  form  a  very  important  condition  in 
marine  animal  life ;  the  enormous  figures  representing  the  square 
inch  amount  of  that  pressure  stirred  men's  imagination,  and  their 
fancies  were  supported  by  the  fact  that  rapid  transference  to  the  sur- 
face from  even  a  moderate  depth  destroys  life ;  but  these  impressions 
were  removed  by  a  remembrance  of  the  laws  of  hydrostatic  pressure, 
and  by  substituting  a  gradual  for  a  rapid  transition  from  deep  water 
to  the  surface.  Temperature,  however,  remains  as  an  undoubtedly 
important  factor. 

3.  Great  differences  in  these  respects  of  depth  and  temperature 
prove  barriers  to  distribution. 

4.  Great  length  of  time  naturally  helps  escape  from  these  barriers, 
for  in  the  lapse  of  years  accidents  are  likely  to  occur  enabling 
species  to  evade  difficulties  which  would  in  ordinary  circumstances 
prove  insurmountable.  Hence  the  finding  of  a  living  species  in  a 
fossil  state  will  always  justify  the  expectation  of  its  having  a  wide 
local  distribution. 

5.  Where  barriers  of  depth  and  temperature  do  not  check  distri- 
bution, there  seems,  in  ordinary  circumstances,  no  limit  to  universality 
of  distribution. 

6.  There  actually  are  existing  species  whose  distribution  is 
universal,  no  barriers  having  availed  against  their  passage. 

7.  Still  there  is  no  trace,  even  in  these  species,  of  essential, 
lasting,  and  progressive  change. 

I  do  not  intend  to  overpress  this  point,  for  I  allow  that  it  pre- 
sents merely  negative  evidence.  I  do  not  assert  that  there  are  no 
species  of  MoUusca  which  have  essentially,  permanently,  and  pro- 
gressively changed.  I  only  say  there  are  some,  even  many,  which 
have  not  done  so,  that  I  do  not  know  any  which  have,  and  that  the 
burden  of  proof  lies  with  those  who  assert  the  positive.  Evolutionists 
are  in  the  way  of  saying  that  a  thing  being  possible  is  therefore  pro- 


INVEKTEBBATA,    ORYPTOGAMIA,    MICROSCOPY,    ETC.  763 

bable,  and  consequently  is  true  unless  the  contrary  be  proved.  I  only 
wisli  to  note  that  this  is  a  reversal  of  all  the  laws  of  evidence  in  any 
case  of  fact  whatever,  and  to  add  that,  so  far  as  I  have  had  the  oppor- 
tunity of  observation,  no  proof  has  reached  me  of  progressive,  perma- 
nent, and  essential  change  in  molluscan  development." 

Antiquity  of  certain  Subordinate  Types  of  Fresh-water  and 
Land  MoUusca.* — Mr.  White  points  out  that  of  the  minor  groups 
into  which  some  of  the  "  comprehensive  "  genera  of  these  forms  have 
been  divided,  a  large  number  had  their  origin  in  periods  which  were 
at  least  as  early  as  the  closing  epochs  of  the  cretaceous  or  of  the 
eocene  periods.  After  a  technical  demonstration  of  these  points,  the 
author,  on  reviewing  the  collections,  finds  that  there  are  in  it  so 
many  "familiar  forms"  that  it  seems  difficult  to  imagine  that  a 
large  number  "  were  living  contemporaneously  with  the  last  of  the 
Dinosaurs."  The  changes  these  Mollusca  have  endured  seem  to  be 
very  remarkable ;  there  was  a  "  gradual  desiccation  of  the  regions 
formerly  occupied  by  the  great  inland  lakes,"  "  the  elevation  of  the 
whole  Eocky  Mountain  system,  and  the  establishment  of  the  present 
great  interior  river-systems."  Although  some  forms  have  disappeared, 
"  the  lines  of  descent  of  the  numerous  types  which  have  reached  us 
unbroken  seem  to  be  almost  parallel,"  and  the  author  comes  to  the 
conclusion  that  in  some  degree  at  any  rate  these  types  have  had  a 
"  saltatory  "  origin,  although  he  allows  that  the  mode  must  always 
remain  obscure. 

Development  of  the  Digestive  Tract  in  the  Mollusca. t — From 
an  abstract  of  the  researches  of  Dr.  W.  K.  Brooks  we  learn  that  he  has 
come  to  certain  definite  conclusions,  of  which  the  following  note  gives 
an  account  of  some  of  the  most  important : — 

(1)  The  polar  globules  mark  the  principal  axis  of  the  egg. 

(2)  When  there  are  four  equal  sjjherules  in  the  egg,  the  proto- 
plasm of  each  is  segregated  ;  that  which  will  give  rise  to  the  ectoderm 
occupies  the  formative  end  and  is  quite  transparent. 

(3)  These  formative  ends  separate  as  four  micromeres. 

(4)  By  their  division,  and  by  the  separation  of  other  cells  from 
the  formative  end  of  the  macromercs,  an  ectoderm  is  formed,  which 
entirely  covers  the  four  macromercs  except  at  the  blastopore. 

(5)  These  macromercs  now  become  fused,  and  part  becomes  sepa- 
rated to  form  the  endodermal  layer  of  cells. 

(6)  The  remainder  divides  into  a  largo  number  of  cells,  which 
occupy  an  intermediate  position. 

(7)  These  are  not  food-yolk,  but  continue  to  grow. 

(8)  The  ectodermal  cells  about  the  blastopore  become  converted 
into  the  shell-area. 

(9)  The  mouth  is  an  independent  invagination  of  the  ectoderm. 

(10)  Which  does  not  become  connected  with  the  digestive  tract 
until  after  the  closure  of  the  blasto])ore. 

(11)  The  stomachal  appears  to  be  the  same  as  the  primitive  cavity. 

*  '  Aiuer.  Journ.  Sci.,'  xx.  (1880)  p.  44. 

t  '  True.  JJostou  Sue.  Nat.  Hist.,'  xxx.  (18S0)  p.  325. 


764  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

(12)  The  "  rectal  plug  "  changes  its  position  from  the  centre  of  the 
shell-area  to  a  point  on  the  ventral  surface,  where  it  forms  the 
definitive  anus. 

(13)  The  structure  and  history  of  the  shell-area  is  substantially  as 
described  by  Eay  Lankester. 

(14)  Periods  of  rest  very  conspicuously  alternate  with  periods  of 
segmentation. 

The  above  observations  apply  to  the  Pulmonata,  and  the  history 
of  the  same  parts  in  the  oyster  is  not  altogether  the  same ;  in  both 
cases,  however,  the  blastopore  is  converted  into  the  shell-area,  and 
the  mouth  is  formed  nearly  opposite,  by  an  invagination  of  the  ecto- 
derm. The  anus  is  in  both  distinct  from  the  blastopore,  but  the  in- 
testine of  the  oyster  appears  to  have  no  relation  to  the  "  invagination 
neck." 

Further  details  are  promised,  and  will  be  welcomed,  as  the 
subject  is  one  on  which  very  various  statements  have  been  made 
by  those  embryologists  who  have  directed  their  attention  to  this 
phylum. 

Action  of  Poisons  on  the  Cephalopoda.*— M.  Yung  gives  an 
account  of  the  effect  of  certain  poisons  on  the  Dibranchiate  forms  on 
which  he  has  been  enabled  to  experiment : — 

Curare  when  injected  subcutaneously  has  no  action,  but  if  two  or 
three  drops  were  injected  into  the  cephalic  artery  they  almost  instan- 
taneously brought  about  a  paralysis  of  the  muscles  of  the  mantle,  and 
then  of  those  of  the  arms  ;  although  the  animal  then  appeared  to  be 
dead,  the  "  hearts  "  continued  to  beat,  and  the  chromatophores  retained 
their  activity. 

Stryclinine  has  a  very  powerful  influence,  for  1  part  in  30,000  of 
sea-water  produced  a  relaxation  of  the  muscles  of  the  chromatophore  ; 
the  respiratory  movements  increased  and  then  fell  rapidly  ;  tetanus 
shortly  followed.  The  animal  emptied  its  ink-bag,  and  a  state  of 
extreme  muscular  rigidity  was  induced ;  examination  nevertlieless 
revealed  the  fact  that  the  venous  hearts  were  still  beating. 

Nicotine  is  still  more  poisonous  to  the  Cejihalopod,  but  it  produces 
a  contraction  of  the  muscles  of  the  chromatophores,  and  the  hearts 
were  arrested  in  their  systole. 

Atropine  appears  to  have  a  very  complex  action,  large  quantities 
are  necessary  to  produce  any  effects,  and  these  consist  in  the  gradual 
lowering  of  the  cardiac  and  respiratory  movements. 

Verairin  is  an  active  poison,  and  produces  ii-regularity  of  move- 
ment, and  an  arrest  in  systole  of  the  hearts. 

Muscarin  has  a  similar  action  to  nicotine  on  the  chromatophores, 
but  the  effect  is  not  so  well  marked ;  it  would  appear  to  slowen  the 
circulation  and  to  increase  the  secretions. 

Upas  antiar,  when  injected  into  the  cephalic  artery,  has  the  effect 
of  throwing  the  animal  into  violent  couvulsious,  the  cardiac  move- 
ments become  very  irregular,  and  after  a  period  of  acceleration  come 
to  an  end  in  the  period  of  systole. 

*  '  Comptes  Keudus,'  xci.  (1880)  p.  306. 


INVERTEBRATA,    CRYPTOGAMIA.,    MICROSCOPY,    ETC.  765 

Regeneration  of  the  Head  in  Gastropods.* — Tlie  first  to  make 
experiments  on  this  subject  was  the  eminent  Si:)allanzaui ;  and  he  was 
followed  by  Pastor  Schaffer,  of  Eegensburg  (1768-1770) ;  these 
observations  have  been  greatly  neglected,  but  Professor  Martens  does 
well  in  referring  to  them  in  the  note  in  which  he  deals  with  the 
recently  published  results  of  Justus  Carriere.  This  naturalist  con- 
firms the  observations  of  his  two  predecessors ;  eyes,  tentacles,  labial 
processes  may  be  completely  regenerated,  but  not  the  pharynx,  or  the 
supra-oesophageal  ganglion,  the  destruction  or  removal  of  which  is 
always  accompanied  by  the  death  of  the  animal.  More  scientific  than 
his  predecessors,  M.  Carriere  was  always  careful  to  see  that  he  had 
really  got,  in  the  removed  portion,  the  organ  he  intended  to  take  away. 
Moreover,  certain  conditions  are  necessary  to  attain  to  complete 
success  ;  the  animals  must  be  in  the  most  satisfactory  vital  conditions 
possible,  and  must  have  their  requirements  in  the  way  of  air,  food,  and 
water  carefully  attended  to  ;  the  experiments  generally  fail  if  under- 
taken at  a  time  when  all  the  energies  of  tlie  animal  are  directed  to 
the  formation  of  the  generative  products ;  the  beginning  of  summer 
and  the  autumn  season  are  the  most  satisfactory  times.  As  to  the 
species.  Helix  nemoralis  and  H.  hortensis  give  the  best  result ;  H.  po- 
matia  is  more  sensitive,  and  H.  arhustorum  and  H.  fruticum  are  still 
more  so.  Aquatic  Pulmonata  give  frequently  unsuccessful  results, 
owing  to  the  fact  that  fungi  are  very  apt  to  become  developed  on 
their  wounds.  It  may  be  suggested  that  the  antiseptic  treatment  can 
be  applied  to  physiological  as  well  as  to  pathological  operations. 

It  is  interesting  to  note  that  the  observer  has  found  that  in  the 
case  of  the  eyes,  at  any  rate,  the  process  of  regeneration  is  com- 
parable to  that  of  the  first  formation  of  that  organ.  There  is  an 
invagination  of  tlie  epithelium,  the  formation  of  a  closed  vesicle,  the 
primitive  cylindrical  cells  become  partly  converted  into  corneal  cells, 
and  i^artly  into  rods  and  cones.  The  complete  regeneration  of  the 
eye  takes  from  fifty  to  sixty  days. 

Activity  and  Structure  of  the  Muscles  of  Mollusca  Acephala.t — 
M.  Constance  has  experimented  on  the  scalloj?,  on  oysters,  on  Anomia, 
Pectunculus,  Venus,  Cardium,  Mytilus,  by  pricking,  striking,  by  induc- 
tion currents,  and  by  changes  of  temperature,  and  finds  that  of  these 
agents  the  current  of  electricity  is  the  most  powerful  and  constant  in 
its  action.  The  muscles  consist  partly  of  striated  fibres  in  Pectcn  ;  in 
the  rest  of  these  Mollusca  the  striated  muscle  is  replaced  by  smooth 
fibre  of  a  special  kind  ;  in  the  Dimijaria  the  two  kinds  may  be  distinct. 
Both  contraction  and  extension  are  voluntary  actions,  and  can  bo 
increased  or  rendered  independent  by  ammonia  vapour,  chloroform, 
&c.,  which,  together  with  changes  of  temperature,  cause  various 
degrees  of  paralysis  of  the- sensitive  organs. 

Pedal  Glands  of  the  Tellinidse.  J  —  In  Tellina  (T.  haltica) 
M.  Barrois  finds  a  small  posterior  opening  on  the  foot,  leading  into 

•  '  Niiturforscher,'  xiii.  (1880)  p.  272. 

+  '  Bull.  Soc.  Acad,  do  Urcst,'  1879.    Sec  '  R.v.  Sci.  Nut.,'  ii.  (ISSO)  p.  117. 

X  '  Bull.  Sci.  Uep.  Nord,'  iii.  (iSSO)  p.  IKS. 


766  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

a  canal  wliicli  ends  in  a  larger  cavity,  plicated  and  lined  witii  glands  ; 
these  structures  represent  the  byssal  apparatus  of  those  Mollusca 
which  possess  it.  The  canal  represents  the  open  groove  of  Cardium 
edule  and  the  half-closed  groove  of  Pecten  maximus  ;  but  these  species 
have  also  certain  glands  situated  in  it,  which  have  no  homologues  in 
Tellina  ;  its  terminal  glands,  however,  represent  the  byssal  glands. 

Scrobicularia  piperata  differs  in  the  arrangement  of  these  parts 
from  Tellina  only  by  the  inferior  length  of  its  canal. 

In  Donax  anatinum,  the  opening  is  also  posteriorly  placed  ;  the 
canal  is  short  and  leads  into  a  cavity  whose  walls  are  covered  with 
cylindrical  epithelium ;  no  gland  cells  occur,  they  are  replaced  by  an 
extremely  dense  mass  of  connective  tissue  which  is  not  stained  by 
reagents  and  shows  no  trace  of  gland  cells.  This  is  the  furthest 
stage  of  degradation  reached  by  the  apparatus  of  the  byssus  in  this 
family. 

Thus  in  these  forms  the  opening  of  the  duct  is  transferred  from 
front  to  back,  the  groove  is  replaced  by  a  canal,  the  glands  of  the 
groove  are  entirely  lost,  and  in  one  of  the  species  [Donax)  the  byssal 
glands  are  aborted. 

Anatomy  of  the  Bullidea.* — M.  Vayssiere  is  principally  occupied 
in  this  essay  with  the  description  of  that  imperfectly  known  form 
Gasteropteron  Meckelii  ;  but  the  difficult  family  to  which  this  species 
belongs  presents  several  points  in  which  our  knowledge  is  very  far 
from  being  satisfactory ;  its  representatives  differ  considerably  from 
one  another  in  their  external  characters,  and  some  among  them  are 
almost  completely  deprived  of  any  shell.  Members  of  the  group  may, 
however,  be  recognized  by  the  facts  that  the  dorsal  region  of  their 
body  is  divided  into  four  parts,  and  that  both  labial  and  dorsal 
tentacles  are  altogether  absent. 

It  will  not  be  necessary  to  follow  our  author  through  the  histori- 
cal chapter  in  his  paper ;  coming  at  once  to  the  genus  Gasteropteron, 
we  find  that  in  it  there  are  at  any  rate  no  more  than  two  described 
species,  G.  Meckelii  of  Kosse,  and  the  very  slightly  different  G.  sinense 
of  A.  Adams.  The  former  species,  with  which  alone  the  French 
naturalist  now  concerns  himself,  is  from  20  to  24  mm.  long,  and  from 
25  to  30  mm.  broad ;  the  body  proper  is  even  much  smaller  than 
this. 

In  its  general  appearance  it  has  no  slight  resemblance  to  a 
Pteropod,  and  in  that  order  the  earlier  naturalists  were  content  to 
place  it ;  the  shell  is  somewhat  difficult  to  detect,  and  was  never 
observed  till  1860,  when  Krohn  signalized  its  appearance ;  it  is  only 
4-5  tenths  of  a  millimetre  in  size,  is  "  nautiliform,"  hyaline,  and  very 
translucent,  so  that  it  has  a  very  striking  resemblance  to  that  of  a 
Carinaria  ;  it  is  found  in  the  hepatic  organ,  is  situated  near  to  the 
anus,  although  somewhat  behind  this  orifice,  and  a  little  on  the 
right  side. 

Digestive  System.— This  portion  of  the  animal  is  exceedingly 
simple ;  the  oral  orifice  is  situated  in  the  centre  of  a  slight  depression, 
and  just  in  front  of  the  anterior  portion  of  the  foot ;  on  either  side 
*  '  Ann.  Sci.  Nat.,'  ix.  (1880),  Art.  1. 


INVEKTEBRATA,   CRYPTOGAMIA,    MICROSCOPY,   ETC.  767 

tliero  are  slight  projections,  and  tliese  give  rise  to  tlio  parapodia, 
which  aid  in  forming  a  kind  of  funnel-shaped  orifice.  Just  behind 
the  mouth  there  is  a  short,  eversible  proboscis,  and  connected  with 
this  there  is  the  obscure  structure  which  is  known  as  the  buccal 
bulb ;  this  somewhat  elongated  organ  is  ovoid  in  general  shape,  and 
has  behind  the  two  swellings  with  which  it  is  provided  a  cylindri- 
cally  shaped  prolongation,  which  is  the  seat  of  origin  of  the  radula. 
The  muscles  of  this  bulb  are,  consequent  on  the  absence  of  any 
chitinous  skeleton,  exceedingly  well  developed;  chitinous  parts  are, 
however,  developed  from  the  epithelial  cells  of  the  bulb,  and  at  onco 
become  sufficiently  strong  to  form  two  small  resisting  plates,  which 
may  well  be  regarded  as  rudimentary  jaws.  These  have  an  interest- 
ing structure  ;  they  are  made  up  of  a  number  of  small,  irregularly 
cylindrical  rods,  closely  set  and  all  directed  towards  a  common 
central  point.  That  they  are  rudimentary  jaws  would  appear  to  bo 
sufficiently  well  established  by  the  comjiarison  which  the  author  has 
instituted  between  them  and  the  similar  structures  of  a  further 
grade  of  development  which  are  to  be  found  in  Bulla  and  in  other 
allied  genera.  In  addition  to  these  rudimentary  jaws,  small  chitinous 
papillas  have  been  detected  at  the  point  where  the  proboscis  passes 
into  the  bulb.  The  support  for  the  radula  occupies  the  base  of  the 
buccal  cavity ;  the  radula  itself  forms  a  band  which  is  twice  as  long 
as  it  is  wide,  the  central  portion  is  unarmed  and  only  presents  some, 
always  small,  chitinous  granules  or  concretions.  On  either  side  there 
is  a  longitudinal  row  of  well-developed  teeth,  and  on  these  there 
follow  five  parallel  rows  of  smaller  lateral  teeth  (uncini). 

The  oesophagus  takes  a  course  a  little  towards  the  left,  and  then 
descends  to  a  somewhat  lower  plane,  where  it  passes  into  what  the 
author  calls  the  second  cavity  of  the  body ;  it  becomes  at  once  con- 
tinuous with  the  stomach.  This  poi'tion  of  the  tract,  in  which  no 
gizzard  seems  to  be  developed,  is  enveloped  by  the  "  hepatico-herma- 
phrodite  mass  "  ;  the  internal  epithelium  is  provided  with  a  number  of 
short  cilia.  As  an  ordinary  rule,  there  open  on  its  surface  ten  distinct 
hepatic  orifices.  The  walls  of  the  intestine  are  even  more  delicate 
than  are  those  of  the  stomach,  and  they  have  no  proper  coloration  ; 
what  they  have  is  due  to  their  contents.  This  region,  somewhat 
equal  in  calibre  to  the  oesophagus,  is  not  dilatable ;  after  some  coiling 
it  ends  on  the  right  side,  in  a  little  pit  behind  the  respiratory  appa- 
ratus. Towards  its  termination  the  musculature  of  its  walls  becomes 
better  developed ;  Foraminifera,  Eadiolaria,  and  diatoms  appear  to 
form  the  chief  food  of  these  molluscs. 

The  salivary  glands  form  two  long,  white,  hyaline  sacs  without 
ramifications,  and  placed  one  on  either  side  of  the  rosophagus,  which 
they  follow  along  its  course,  although  without  contracting  any  con- 
nection with  it,  and  they  open  into  the  buccal  cavity  by  narrow  ducts, 
just  above  the  ccsophagus.  The  glandular  layer  is  formed  of  two 
rows  of  cells,  of  some  size  but  irregular  in  form  ;  their  nucleus  is 
distinctly  visible. 

The  liver,  contrary  to  what  obtains  in  most  of  tlic  Opistho- 
brancliiata,  is  not  compact,  nor  docs  it  open  into  the  stomach  by 


768  RECORD    OF    CURRENT    RESEARCHES   RELATING   TO 

a  single  orifice.  It  is  made  up  of  a  certain  number  of  completely- 
separated  glands,  while  each  has  a  special  duct  which  opens  directly 
into  the  stomach.  These  ducts  and  the  lobes  of  the  glands  do,  how- 
ever, become  somewhat  entangled,  and  thus  give  rise  to  the  appearance 
of  a  single  compact  mass,  by  which  the  subdivision  of  the  organ  is  at 
first  sight  obscured.  Ten  distinct  lobes  may  be  generally  made  out. 
The  ultimate  cells  are  large,  polymorphous,  and  variously  coloured  ; 
they  contain  vesicles  which  may.  either  be  scattered  through  the  cell 
or  aggregated  into  a  small  central  mass ;  they  vary  in  coloui-  through 
different  shades  of  yellow. 

The  author  applies  the  term  independent  glands  to  certain  distinct 
structures  ;  these  are  (1)  Circumoral  glands  and  (2)  posterior  gland  of 
the  foot.  The  former  are  found  in  the  integument  around  the  orifice 
of  the  proboscis,  and  within  the  first  cavity  of  the  body ;  they  vary  a 
good  deal  in  form,  but  always  end  in  an  excretory  duct,  which  opens 
at  the  entrance  to  the  orifice  of  the  proboscis.  Their  contents  are 
hyaline,  and  are  made  up  of  nucleated  vesicles  with  a  nucleolus,  and 
granular  bodies  suspended  in  a  colourless  liquid.  They  are  not,  as 
the  author  first  thought,  unicellular  glands,  notwithstanding  the  sim- 
plicity of  their  structure.  Their  function  appears  to  be  that  of 
assisting  in  the  prehension  of  the  microscopic  organisms  which  form 
the  food  of  these  creatures. 

The  posterior  gland  of  the  foot  appears  to  have  escaped  notice 
altogether  ;  this  is  the  more  remarkable  since  it  is  visible  to  the  naked 
eye.  In  general  constitution  this  gland  has  much  the  same  structure 
as  those  around  the  mouth  ;  its  secretion  is  in  the  form  of  a  rich  supply 
of  mucus,  which  seems  to  form  a  kind  of  raft  for  the  animal,  and 
thereby  to  enable  it  to  float  on  the  surface  of  the  sea. 

The  organ  of  Bojanus  is  of  some  size,  is  placed  on  the  right 
side  of  the  body,  is  of  an  ochreous  yellow  tint,  and  somewhat  trans- 
lucent. Spongy  in  constitution,  its  cell-elements  are  spherical  in 
form,  and  among  their  contents  it  was  not  possible  to  detect  any 
crystals  of  uric  acid.  On  its  external  wall  there  is,  in  front  of  the 
anus,  a  constant  black  spot ;  this,  on  careful  examination,  was  seen  to 
have  in  its  centre  five  or  six  small  orifices,  by  means  of  which  the 
gland  communicates  with  the  exterior.  The  walls  of  the  gland  are, 
as  is  usual,  richly  supplied  with  veins. 

Bed  Gland. — This  gland,  the  presence  of  which  the  most  super- 
ficial observer  cannot  fail  to  detect,  extends  over  a  portion  of  the 
intestine  and  over  the  walls  of  the  "  copulatory  pouch."  Its  con- 
stituent cells,  though  smaller,  are  not  unlike  in  character  to  those  of 
the  organ  of  Bojanus  ;  the  contained  granular  bodies  are  greyish  or  of 
a  bright  red,  and  disappear  altogether  under  the  action  of  acids.  The 
author  is  forced  to  content  himself  and  his  readers  with  an  account  of 
the  structural  characters  of  the  body,  as  he  is  unable  to  offer  any  definite 
suggestion  as  to  what  its  function  may  be. 

Bespiratory  and  Circulatory  Organs. — These  must  be  dealt  with 
very  briefly  ;  the  former  consists  of  a  semi-pinnate  branchial  plume, 
made  up  of  a  number  of  lamellae,  more  or  less  free  at  their  extremity, 
and  invested  by  an  excessively  delicate  tissue.     The  external  orifice 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  769 

of  the  "  aquiferous  system "  appears  to  lie  a  little  above  the  genital 
orifice  ;  the  heart  has  its  long  axis  set  transversely  to  that  of  the  body, 
and  the  ventricle  is,  in  position,  a  little  superior  to  the  auricle ;  the 
aorta  is  a  vessel  of  some  size  which  bifurcates  at  a  very  short  distance 
from  the  heart  into  an  anterior  and  a  posterior  aorta.  These  and 
their  branches  have  their  course  described  in  some  detail ;  but,  in  con- 
sequence of  the  rarity  and  small  size  of  these  creatures,  the  author 
is  not  able  to  make  this  chapter  as  complete  as  he  could  wish. 

Reproductive  Organs. — Hermaphroditism  appears  to  be  especially 
complete  in  Gasteropteron,  for  there  is  only  a  single  duct  for  the  pur 
pose  of  carrying  away  the  male  and  female  products.  But  our  spaco 
does  not  permit  us  following  the  author  through  his  important  account 
of  the  details. 

Nervous  System. — The  oesoiDhageal  collar  is  formed  by  three  pairs 
of  ganglia,  connected  together  by  commissures  of  different  lengths ; 
all  these — cerebral,  pedal,  and  visceral — are  placed  more  or  less  to  the 
sides  of  the  collar,  but  the  first  have,  of  course,  a  more  distinctly 
dorsal  position.  Among  the  protecting  parts  we  may  note  a  mass  of 
hyaline  cells  which  ajjjDear  to  be  in  relation  to  the  integument ;  re- 
calling by  their  character  hypodermic  glands,  they  seem  to  discharge 
a  more  or  less  mucilaginous  fluid  which  aids  in  lessening  any  shocks 
to  the  nervous  centres. 

After  giving  a  detailed  description  of  these  ganglia  and  of  the 
nerves  which  pass  off  from  them,  the  author  turns  to  the  stomato- 
gastric  and  to  the  genital  ganglia ;  the  sense-organs  are  next  dealt 
with,  and  here  we  have  to  note  that,  although  the  dorsal  tentacles  are 
in  all  Bullidea  completely  wanting,  and  are  partially  replaced  by  the 
cephalic  disk,  this  last-mentioned  organ  must  not  be  considered 
merely  as  an  atrophied  tactile  organ,  for  the  olfactory  sense,  which  is 
ordinarily  exercised  by  the  extremity  of  the  tentacles,  has  its  seat  in 
a  more  or  less  well-marked  differentiation  of  that  portion  of  the  integu- 
ment which  lies  between  the  cephalic  disk  and  the  foot ;  in  Gasterop- 
teron this  sense  seems  to  be  completely  absent,  but  the  tactile  organs 
are,  as  comi)ared  with  the  allied  forms,  very  richly  developed.  After 
a  description  of  the  optic  and  auditory  organs,  the  author  passes  to 

Tlie  Anatomy  of  some  Allied  Genera  {Doridium,Philine,  Scaphander, 
and  Bulla) ;  of  this  the  following  is  a  very  brief  abstract. — The  most 
striking  point  in  Doridimn  is  the  structure  of  its  copulatory  organ  ;  in 
this  genus  the  penis  does  not,  as  in  most  Molliisca,  form  a  thick- walled 
tube,  but  a  canal  not  completely  closed,  for  four-fifths  of  its  length 
the  left  edge  of  the  canal  lies  over  the  right,  but  at  its  superior 
cxtronity  there  is  a  kind  of  groove,  which  is  so  formed  that  the  orifice 
of  the  duct  is  not  terminal,  but  ventral  in  position. 

In  Philine  and  Scaphander  the  salivary  glands  are  very  short  and 
cylindrical,  instead  of  being  elongated  as  they  aic  in  most  members  of 
this  family  ;  there  are  only  two  hepatic  orifices,  and  the  circumoral 
glands  are  feebly  developed.  The  olfactory  and  optic  organs  aro 
exceedingly  rudimentary ;  the  jicnis  of  Philine  is  hammer-shaped, 
while  in  Scaphander  this  organ  is  completely  absent. 

As  to  classification,  M.  Vnyssi^re  docs  not  find  himself  in  agrcc- 

VOIi.  III.  3   E 


770  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

ment  with  Ihering,  wlio  would  separate  Gasteropteron,  Philine,  and 
Scaphander  from  the  Bullidea  ;  the  French  anatomist  would,  however, 
retain  Woodward's  family,  and  would  form  in  it  two  subdivisions,  in 
one  of  which  O aster opter on  is  the  only  genus  ;  these  two  subdivisions 
may  be  thus  characterized.  In  the  first,  the  paraj^odia  are  largely 
developed,  a  small  nautiloid  shell  is  contained  within  the  mantle,  and 
the  oesophageal  collar  is  made  up  of  a  pair  of  cerebral  ganglia,  of  a 
pair  of  pedal,  and  of  six  visceral  ganglia ;  the  last  being  arranged  by 
three  to  the  right,  and  three  to  the  left. 

In  the  second  division  the  parapodia  are  always  rudimentary,  the 
shell  is  always  very  distinct,  is  never  nautiliform,  and  may  be  well 
developed  and  external ;  there  are  only  three  visceral  ganglia  in  the 
oesophageal  collar,  and  of  these,  two  are  placed  to  the  right,  and  one 
to  the  left.  Here,  too,  we  find  that  the  genital  nerve  always  arises 
from  the  larger  of  the  two  left  visceral  ganglia,  while  in  Gasteropteron 
it  arises  directly  from  the  commissure  without  the  intermediation  of 
any  ganglionic  enlargement ;  while  the  branchial  nerve,  which,  in 
Gasteropteron  always  arises  from  the  right  visceral  centres,  may  in 
them  be  derived  from  the  right  visceral  ganglion,  from  the  right  half 
of  the  commissure,  or  from  a  ganglion  placed  in  the  middle  of  this 
connecting  cord. 

Development  of  Teredo.* — Dr.  Hatschek  has  extended  his  obser- 
vations in  development  to  the  Lamellibranchiate  Mollusca. 

The  youngest  ovarian  ova  are  pyriform  in  shape,  and  are  attached 
by  their  stalk  to  the  wall  of  the  ovary  ;  the  germinal  vesicle  is  excentric  ; 
the  fertilized  ova  and  the  embryos  are  found  within  the  gills  of  the 
mother,  where  in  numerous  individuals  it  is  often  possible  to  see  three 
different  stages  ;  the  older  being  in  the  more  anterior  region.  It  is 
soon  possible  to  observe  in  an  unsegmented  ovum  a  clear  animal  and 
a  darker  vegetative  pole ;  after  the  first  segmentation  we  'have  two 
unequal  spheres,  the  smaller  or  more  anterior  of  which  is  not  so  dark 
as  the  other,  in  consequence  of  the  less  close  packing  of  the  yolk- 
granules.  The  author  is  of  opinion  that  in  all  Bilateria  a  bilateral 
symmetry  is  to  be  made  out  in  the  ovum,  just  as  in  all  Metazoa  there 
is  a  polar  differentiation  of  the  same  cell.  Observations  on  the  process 
of  segmentation  show  that  the  ectoderm  is  formed  from  the  clearer 
cells,  while  the  unpaired  larger  segmentation-sphere  goes  to  form  the 
mesoderm  and  endoderm  ;  no  cleavage  cavity  was  to  be  observed. 

The  rudiments  of  the  former  of  these  two  inner  layers  are  develojied 
from  the  large  dark  cell  by  the  separation  of  a  smaller  piece,  which 
occupies  the  hinder  pole  of  the  embryo  and  divides  into  two  cells 
which  become  placed  symmetrically,  one  on  either  side  ;  they  are 
darker  than  the  ectodermal  cells,  and  their  nuclei  are  larger,  so  that 
they  altogether  resemble  in  character  the  primitive  mesodermal  cells 
of  Unio,  Planorbis,  Pedicellina,  and  the  Annelids. 

The  gastrula  arises  by  epiboly  and  its  free  edge  is  formed  by  the 
ectodermal  layer ;  there  is  still  a  single  large  endodermal  cell,  which 
does  not  become  divided  for  some  time,  and,  even  after  the  commence- 

*  '  Claus's  Arbeiten,'  iii.  (1880)  p.  1. 


INTERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  771 

ment  of  the  formation  of  the  oesophagus,  there  are  only  two  enclodermal 
cells.  As  the  embryo  changes  from  its  ovoid  form,  we  get  a  flattened 
pre-oral,  a  conical  post-oral,  and  a  rounded  posterior  region.  With 
high  powers  it  is  possible  to  see,  at  some  distance  from  the  mouth,  a 
double  circlet  of  delicate  cilia,  supported  on  two  special  rows  of  ecto- 
dermal cells. 

The  two  large  ectodermal  cells  divide,  and  form  the  posterior 
endodermal  mass  ;  a  double  pre-oral  ciliary  cii'clet  becomes  developed. 
Soon  the  whole  siu-face  of  the  embryo  is  covered  with  cilia,  the  only 
naked  region  being  a  portion  of  the  hinder  part  of  the  dorsal  surface. 
The  ectodermal  cells  begin  to  form  a  shell-gland,  and  this,  at  a  later 
stage,  forms  a  deep  thick-walled  saccule  with  a  narrow  cylindrical 
lumen ;  its  orifice  and  margin  are  covered  by  a  delicate  chitinous 
cuticle,  which  represents  the  earliest  rudiment  of  the  shell,  and  indi- 
cates thereby  the  primitively  unpaired  condition  of  this  organ. 

From  the  primary  mesodermal  cells  two  or  three  smaller  ones 
have  been  budded  off  on  either  side,  and  pushed  forwards  ;  tho 
characters  of  these  parts  strongly  call  to  mind  the  arrangements  which 
obtain  in  Criodrilus.  The  shell  becomes  double  while  still  very  thin, 
and  almost  cuticular  in  character. 

At  a  somewhat  later  stage  the  form  of  the  body  and  the  rudiments 
of  the  organs  call  to  mind  the  disposition  of  parts  in  the  trochophore 
stage  of  the  Annelid-larva ;  the  stages  next  succeeding  arc  very 
markedly  affected  by  the  development  of  the  shell,  which  has  grown 
considerably,  and  about  this  time  the  double  pre-oral  circlet  of  cilia 
disappears.  The  development  of  the  musculature  is  now  rapidly 
going  on  ;  and  a  number  of  separate  parts  soon  become  well  marked ; 
still  do  the  primitive  mesodermal  cells  retain  their  large  size.  As  tho 
shell  grows,  takes  on  a  yellowish  coloration,  and  becomes  marked  by 
parallel  lines  of  growth,  the  characters  of  the  ciliation  become  much 
changed ;  cilia  have  disappeared  from  the  frontal  area  and  from  tho 
ventral  surface  ;  in  the  oral  region,  pre-oral,  post-oral,  and  adoral 
zones  are  to  be  distinguished. 

As  the  larva  at  this  stage  is  completely  trochophoral,  save  only  as 
regards  the  presence  of  a  shell  and  a  mantle  to  indicate  its  molluscan 
ancestry,  we  have  to  look  for  a  similarly  well-marked  excretory  organ  ; 
this,  just  like  the  kidney  of  the  Trochophore,  is  to  bo  found  at  tho 
anterior  end  of  the  mesentery,  where  it  forms  a  longish  organ,  with  a 
delicate  lumen,  and  ciliated  internally.  As  this  body  elongates  it 
becomes  connected  with  the  ectoderm  and  gets  to  open  to  the  exterior 
by  means  of  an  orifice  in  this  layer. 

As  we  cannot  follow  the  author  through  all  his  further  details,  wo 
will  pass  to  the  concluding  part  of  this  descriptive  chapter,  in  which 
he  speaks  of  tl;e  developnient  of  the  gills.  In  the  maiith;  cavity,  at 
tho  sides  of  the  trunk,  there  appears  a  ridge  of  ectoderm,  wliich  belongs 
to  the  inner  lamella  of  the  mantle-fold.  Later  on,  the  hinder  portion 
of  this  branchial  ridge  gets  set  at  right  angles  to  the  anterior,  and  at 
the  angle  the  rudiment  of  tho  gill  is  best  developed.  At  a  point  near 
the  free  cd^o  the  two  layers,  of  wliich  tho  fold  is  composed,  bccomo 
thinner ;  depressions  ap})car  in  this  which  lead  to  tho  breaking  up  of 

3  E  2 


772  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

tlie  gill,  which,  at  about  the  same  time,  becomes  marked  off  from  the 
inner  mautlo-lamella  by  the  ingrowing  of  the  fold. 

After  some  considerations  on  the  early  appearance  of  the  bilateral 
ai-rangement,  to  which  attention  has  been  called  above,  the  author 
says  that,  with  the  exception  of  the  Echinodermata,  the  Trocho- 
zoon  appears  to  be  the  primitive  form  for  all  the  rest ;  WormSj 
Molluscs,  Molluscoids,  Arthropods,  and  Vertebrates  may  therefore 
be  distinguished  as  Euhilateria.  The  blastopore  closes  along  the 
middle  line,  and  the  mouth  appears  at  the  point  at  which  lay  its 
final  remnant ;  the  formation  of  an  ectodermal  fore-gut  appears 
to  have  happened  very  early,  and,  after  this,  the  formation  of  the 
mesoderm  is  the  oldest  phenomena.  The  mode  of  development  of 
the  mesodermal  organs  is  a  matter  of  great  interest ;  in  the  Annelids 
the  differentiation  of  the  mesodermal  bands  leads  to  the  distinction 
between  the  head  and  trunk ;  the  relations  between  the  trochophore 
and  the  Teredo-larva  are  so  close  that  their  common  ancestry  is  not 
to  be  doubted ;  the  early  development  of  the  shell  is  only  another 
examj)le  of  the  appearance  before  its  historic  time  of  an  organ  which 
plays  an  important  part  in  the  organization  of  the  individual. 

When  we  try  to  trace  the  phylogenetic  history  of  the  mollusc,  we 
see  that  there  were  added  to  the  organs  of  the  Trochozoon,  first,  the 
ventral  ganglion  of  the  trunk  with  the  auditory  vesicles,  the  paired 
trunk-kidneys,  opening  by  special  ciliated  infundibula  into  the 
secondary  coelom  ;  and  the  dorsal  heart.  These  organs  characterize 
the  primitive  ancestor  of  both  annelids  and  molluscs ;  then,  for  the 
mollusc,  there  aj^peared  the  hepatic  diverticula  of  the  stomach,  the 
dorsal  shell,  the  mantle-fold,  the  muscular  foot,  and  the  primary  gills. 
When  the  foot  appeared,  the  free-swimming  mode  of  life  was  lost, 
and  the  velum  began  to  atrophy.  If  this  be  really  the  true  history 
of  the  Mollusca,  it  is  clear  that  the  "  step-ladder  "  form  of  the  ventral 
ganglia  (Ihering)  cannot  be  regarded  as  an  indication  of  a  pre- 
existing segmentation.  The  lateral  approximation  of  the  pedal  ganglia 
is  a  secondary  character,  and  so,  much  more,  is  the  approximation 
and  final  fusion  of  these  centres  with  the  oesophageal  ganglion. 

Do  the  facts  of  development  as  now  known  to  us  support  the 
monophyletic  or  the  polyphyletic  (Ihering)  theory  of  the  history 
of  the  Mollusca  ?  Hatschek  believes  that  the  ventral  ganglia  took 
their  origin  from  an  ectodermal  thickening  on  the  ventral  side  of  the 
trunk-region,  and  that  their  approximation  to  the  oesophageal  ganglion 
in  the  Nudibranchiata  is  the  result  of  a  secondary  process.  Ihering 
would  think  that  in  (his)  Platycochlides  the  supra-oesophageal,  as  well 
as  the  pedal  ganglia,  had  their  origin  in  the  frontal  plate.  Further 
investigation  of  known  facts,  and  further  study  into  still  unexplored 
regions,  can  alone  decide  what  answer  is  to  be  given  to  these  two 
questions. 

Molluscoida. 

Development  of  Lingula.* — M.  Joliet  has  an  analysis  of 
Mr.   W.    K.    Brooks's   important    contribution    to    this   subject,   to 

*  '  Avfli.  Zool.  Exp.  ct  Gc'u.,'  1880,  p.  390. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY^    ETC.  773 

the  general  conclusions  of  which  we  direct  attention.  Dealing 
with  the  zoological  position  of  the  Brachiopoda,  the  author  points 
out  that  embryological  investigations  have  shown  us  that  the  re- 
semblances between  the  gills  of  Tunicates,  Brachiopods,  and  Lamelli- 
branches  are  adult  characteristics  which  have  been  arrived  at  by 
very  different  ways.  The  larvsB  of  the  higher  Brachiopods  present 
a  striking  resemblance  to  the  larva  of  Loxosoma ;  those  of  lower 
forms,  e.  g.  Lingula,  have  a  striking  similarity  to  the  adult  (and 
especially  to  the  fresh-water)  Polyzoa ;  the  autlior's  facts  seem  to 
him  to  show  conclusively  the  real  resemblance  between  the  two 
groujis.  When  the  adult  instead  of  the  young  is  examined,  we 
have  incontestably  to  do  with  a  solitary  Bryozoon,  provided  with 
a  nervous  system  and  with  highly  specialized  sensory  organs.  The 
relations  of  the  Brachiopoda  to  the  Vermes  are  much  less  distinct 
than  Morse  imagines ;  their  relations  to  the  Bryozoa  are  very  definite. 
As  to  this  last,  its  affinities  to  the  Veliger-form  are  quite  appai-cnt ; 
the  velum  corresponds  to  the  lophophore,  the  epistoma  with  its 
ganglion  corresponds  to  the  foot  and  the  pedal  ganglion ;  the  shell 
and  its  operculum  correspond  to  the  cell  and  operculum  of  the 
Cheilostomatous  Polyzoa,  and  the  retractor  muscles  are  "  clearly 
homologous."  The  Brachioi)oda,  then,  may  be  taken  to  be  the  most 
highly  si)ecialized  representatives  of  the  Bryozoan  branch,  and  the 
Mollusca  proper  have  a  similar  relation  to  the  FeZ/^<?r-phylum. 

In  conclusion,  the  author  insists  on  the  long  persistence  of  Lingula 
as  showing  that  the  facts  of  zoology  absolutely  forbid  us  to  believe 
that  there  must  be  a  continuous  evolution  of  forms  owing  to  a 
continuous  progress  upwards. 

Structure  of  Adeona.* — Dr.  Kirchenpauer  has  given  the  first 
detailed  account  of  one  of  the  most  curious  and  but  little  known  of 
the  Bryozoa.  In  1812  Lamouroux  described  Adeona,  and  at  first 
placed  it  among  the  Isidinfe,  but  subsequently  under  Escharida), 
which  included  Eschara,  Bctepora,  Krustensterna,  Hornera,  Tilesia, 
Discopora,  Dtastopora,  and  Celleporaria ;  but  as  no  figures  of  the 
minute  structure  were  given,  it  remained  doubtful  if  Lamouroux  had 
correctly  j)laced  the  genus.  In  1819  Schweigger,  who  considered  it 
related  to  NulUpora,  discussed  both  among  tlie  corals,  but  gave  very 
fair  figures  showing  the  zooccial  cells  of  the  Bryozoa ;  the  work  is, 
however,  probably  known  to  few. 

The  structure  of  Adeona  is  interesting  in  several  particulars,  but 
more  especially  in  tlie  jointed  radical,  upon  which  character  the 
genus  as  now  described  is  established.  This  consists  of  calcareous 
joints  with  irregular  chitinous  intervals,  forming  a  flexible  stem  much 
like  Isis,  so  that  it  has  luiturally  been  frequently  compared  to  it. 
Kirchenpauer  finds,  in  making  sections  through  this  radical,  that  there 
are  fine  connecting  tubes  passing  from  the  chitinous  jiortiou  through 
the  calcareous  joints.  In  one  species  the  zoarium  from  which  this  root 
springs  is  a  calcareous  f(diaccou8  growth,  much  resembling  in  shape 

*  "  Ueboj- d.  Bryozoen-Guttung  i4rftww,"  von  Dr.  KirchenpaiUT,  '  Journ.  Mus. 
Godcffroy,'  1880. 


774  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

EscJiara  foliacea  var.  angustifolia.  In  otlier  species,  however,  tho 
zoarium  consists  of  a  flat  reticulated  or  feuestratecT  flabelliform 
lamella,  consisting  of  a  double  layer  of  zooecia,  having  the  characters 
of  Lepralia,  as  we  now  understand  it,  according  to  Mr.  Hincks's 
classification. 

The  calcareous  stalk,  from  which  grow  one  or  many  of  these 
jointed  roots,  is  pointed  at  the  base,  and  spreads  out  in  the  flabelliform 
manner  mentioned.  This  is  strengthened  by  numerous  ribs,  which 
spread  through  the  zoarium,  reminding  us  somewhat  of  the  ribs  of 
a  leaf,  and  these,  besides  bifurcating,  sometimes  anastomose.  Micro- 
scopical sections  show  that  these  thicker  parts,  which  we  are  obliged 
to  speak  of  as  ribs,  are  formed  by  a  thickening  of  the  lamella ;  for 
here,  instead  of  finding  the  zooecial  chambers  near  the  surface,  they 
are  found  back  to  back  in  the  median  line,  and  over  them  is  a  con- 
siderable thickness  of  calcareous  growth,  which  seems  to  be  similar 
to  that  four.d  in  the  older  parts  of  Myriozoum  and  Eschara,  where  the 
oral  aperture  is  often  covered  by  a  growth  two  or  three  times  larger 
than  the  zocecium. 

All  known  species  of  the  genus  are  from  Australia  and  South 
Africa,  and  the  root  structure  is  sufficiently  characteristic  for  them 
to  be  kept  together  at  present,  though  it  may  be  found  advisable  in 
the  future  to  base  classification  more  entirely  upon  the  form  of  the 
zooecial  cell. 

New  Genus  of  Polyzoa.* — Mr.  J.  B.  Wilson  describes  a  new 
genus  of  Cheilostomata  closely  allied  to  Catenicella,  and  to  express 
that  affinity  the  name  Catenicellopsis  has,  at  Professor  McCoy's  sug- 
gestion, been  given  to  it.  The  two  species  as  yet  known  are  separated 
from  Catenicella  on  the  same  ground  that  was  considered  sufficient  to 
justify  the  separation  of  Alysidium  from  that  genus,  namely,  the  mode 
of  branching. 

The  diagnosis  of  the  genus  is :  Cells  arising,  for  the  most  pai-t, 
from  the  upper  and  back  of  other  cells  by  a  short  chitinous  tube ; 
cells  at  each  bifurcation  commonly  geminate ;  cells  also  frequently 
arising  by  a  short  chitinous  tube  from  the  side  of  another  single  cell, 
immediately  below  the  lateral  process. 

The  two  species  are  C.  pusilla  and  C.  delicatula,  the  first  growing 
on  Gystopliora  in  small  glassy  tufts  about  -J  inch  high,  and  the  latter 
on  sea-weed  or  larger  forms  of  Catenicella  in  tufts  1  and  2  inches 
high. 

Arthropoda. 

«.  Insecta. 

;•'  Little-known  Organ  of  the  Hymenoptera.f  —  The  organ,  as 
described  by  MM.  Canestrini  and  Berlese,  consists  of  a  dejjression 
on  the  first  tarsal  joint  of  the  first  pair  of  legs,  and  of  a  spur  at  the 
apex  of  the  tibia,  either  simple,  bifid,  or  armed  with  spines,  and  often 
protected  by  a  chitinous  sheath.  The  spur  is  a  modified  sj^ine,  for 
two  spines  are  found  in  the  same  j)Osition  on  the  second  and  third 

*  '  Journ.  Micr.  Soc.  Vict.,'  i.  (1880)  pp.  64-65  (1  plate). 
t  '  Bull.  Soc.  Veneto-Trent.,'  i.  (1880)  p.  154. 


INVERTEBEATA,    CRTPTOGAMIA,    MICROSCOPY,    ETC.  775 

pairs  (in  other  insects  on  tlie  first  also) ;  of  these  one  persists  in  the 
first  pair  as  the  sjiur  above  mentioned,  the  other  becomes  rudimentary. 
No  muscles  for  moving  the  spur  have  been  found,  and  its  function  is 
that  of  cleaning  the  tongue,  and  perhaps  the  antennae  also.  These 
conclusions  were  derived  from  a  study  of  many  families  of  the 
order. 

Honey-hearing  Ants. — At  p.  242  we  gave  a  short  account  *  of 
the  Eev.  Dr.  McCook's  observations  on  some  of  these  ants  from 
Colorado,  which  with  the  head  and  thorax  of  a  small  ant  have  all  the 
posterior  portion  of  the  body  distended  into  a  reservoir  of  honey,  the 
size  of  a  large  pea  and  of  a  rich  translucent  amber  hue.  The 
creatures  cling  to  the  rough  roof  of  the  chambers  with  their  feet, 
the  honey-bag  hanging  downwards.  Not  only  is  the  abdomen  con- 
verted into  a  receptacle  for  honey,  but  the  whole  internal  economy 
of  the  body  is  transformed  for  this  purj^ose  ;  all  the  organs  of  the 
abdomen  having  quite  disappeared,  and  there  remains  only  a  thin 
transparent  skin.  Dr.  McCook  was  able  to  discover  that  the  working 
ants,  returning  from  their  outdoor  foraging  with  their  bodies  distended 
with  the  honey  they  had  harvested,  eject  it  from  their  own  mouths 
into  those  of  the  honey-bearers,  whose  bodies  thus  become  distended 
with  it.  The  honey-bearer  seemed  to  slightly  contract  the  muscles 
of  the  abdominal  skin,  forcing  from  its  mouth  minute  globules  of 
honey ;  these  clung  to  the  bail's  of  the  under  lij)  and  were  eagerly 
lapped  up  by  the  hungry  ants  waiting  to  be  fed.  It  is  probable, 
however,  that  the  supplies  are  principally  intended  as  winter-stores 
for  the  worlcers,  for  feeding  the  larva),  or  for  the  queen. 

Since  the  period  when  the  above  observations  were  made. 
Dr.  McCook  has  had  under  his  constant  sui^ervision  an  artificial 
formicary  of  the  ants,  and  has  made  some  fm-ther  interesting  com- 
munications in  regard  to  them.t  The  most  striking  points  relate  to 
two  particulars,  one  bearing  on  the  sympathy,  or  spirit  of  beneficence, 
of  the  ants  ;  the  other  relating  to  tlieir  anatomy. 

Sir  John  Lubbock  has  shown  that  while  ants  were  full  of  hostility 
against  individual  foes,  they  showed  no  sympathy  for  friends  in 
trouble.  The  comfort  of  the  poor  honey-bearers,  for  instance,  whilo 
the  workers  were  excavating,  was  utterly  ignored.  They  lay  help- 
lessly where  they  had  been  dropped,  and  were  treated  by  the  other  ants 
as  if  they  had  been  so  many  lifeless  impediments  to  their  work. 
Instead  of  making  a  detour  ai-ound  tlicm,  the  Avorkers  went  straight 
forward,  clambering  over  any  that  lay  in  their  path,  and  even 
dropping  the  i)ellets  of  earth  which  they  brought  out  from  tho 
excavations  upon  and  around  them,  until  some  of  the  houcy-bearera 
were  almost  buried.  There  seemed  hero  a  lack  both  of  sympathy  and 
of  intelligence. 

The  honey-bearers  are  not,  however,  quite  helpless;  they  liavo 
tho  full  use  of  their  legs,  though  their  movements  are  necessarily 
made  at  a  disadvantage,  from  the  angle  into  which  tho  head  and 
thorax  aro  thrown  by  the  swollen  condition  of  the  abdomen  ;  yet  they 

*  See  also  '  Journ.  of  Si-ioncc,'  ii.  (1880)  p.  87.  t  Ibid.,  p.  430. 


776  RECOBD    OF    CURRENT   RESEARCHES   RELATING   TO 

have  been  observed  to  move  by  their  own  efforts,  and  it  is  not 
impossible  that  they  themselves  regain  their  favourite  position  on  the 
ceiling  of  the  nest  when  accidentally  displaced.  The  reason  of  their 
preferring  this  position  may  be  from  the  uncomfortable  attitude 
which  they  are  forced  to  assume  on  the  floor  of  the  nest.  The 
workers,  so  far  as  could  be  seen,  made  no  attempt  to  replace  them.  It 
may  seem  that  an  intense  muscular  effort  would  be  required  to  sustain 
their  great  weight  in  this  position.  That  ants,  and  insects  generally, 
are  excessively  muscular,  as  compared  with  the  larger  animals,  is  well 
known.  And  the  honey-bearers  are  more  muscular  than  ants 
generally,  their  legs  being  simply  bundles  of  powerful  muscles.  But 
it  is  rather  difficult  to  conceive  how  muscular  effort  can  be  brought 
to  bear  to  overcome  the  action  of  gravity  in  this  position,  unless  by 
some  clasping  of  the  terminal  hooks  of  the  feet  around  the  excres- 
cences of  the  rough  ceiling.  It  seems  more  probable  that  support 
is  gained  by  the  action  of  the  sucking-disk,  which  ants  possess  in 
common  with  many  other  insects. 

An  observation  of  some  importance  in  respect  to  the  question  of 
ant  intelligence  is  that  regarding  the  demeanour  of  the  ants  towards 
dead  honey-bearers.  In  this  case  it  is  their  habit  to  separate  the 
head  and  thorax  from  the  honey-bag,  burying  the  former  in  the  fixed 
cemetery  which  these  ants  usually  establish  in  the  earth  outside  their 
nests.  But  though  the  honey-bag  remains,  full  of  its  sweet  contents, 
the  ants — either  from  resjiect  for  the  dead  or  from  lack  of  mental 
power  to  devise  a  new  means  of  getting  at  its  honeyed  freight — seem 
to  make  no  effort  to  penetrate  its  transparent  wall.  This  is  singular, 
in  view  of  tlie  avidity  with  which  they  will  lick  up  the  smallest 
portion  of  sweet  food  offered  them  in  any  uncovered  condition. 

As  to  their  anatomy,  it  was  previously  said  that  the  whole  abdomen 
appeared,  to  be  occupied  by  the  honey,  its  organs  seeming  to  be  oblite- 
rated, so  that  only  a  thin  transparent  skin  remained.  But  anatomical 
observation  shows  that  this  external  appearance  does  not  give  the 
true  facts  of  the  case.  All  the  abdominal  organs  remain,  but  so 
strangely  distorted  and  compressed  as  to  be  almost  imperceptible. 
The  fact  is  that  any  of  these  ants  may,  if  necessary,  be  converted  into 
a  honey-bearer,  and  that  the  worker,  when  on  her  way  home  with 
her  abdomen  distended  with  the  fruits  of  her  nocturnal  labour,  has 
made  a  step  towards  the  condition  of  the  fully  developed  honey- 
bearer. 

Of  the  three  special  expansions  of  the  intestinal  tract  of  the 
abdomen  of  the  ant  (the  crop,  the  gizzard,  and  the  stomach)  it  is 
the  crop,  into  which  the  oesophagus  immediately  opens,  which  is  the 
recipient  of  the  honey.  As  its  stores  increase,  by  continual  additions, 
it  expands  more  and  more,  pressing  outward  the  extensible  walls  of 
the  abdomen,  and  compressing  the  remaining  portions  of  the  intestine 
into  a  smaller  and  smaller  space.  In  a  fully  laden  honey-bearer  the 
crop  has  become  so  expanded  that  it  fills  nearly  the  whole  interior  of 
the  greatly  dilated  abdomen ;  the  dorsal  vessel,  or  heart,  being  com- 
pressed  and   flattened   against   its   upper   wall ;   while  the  gizzard, 


INVERTEBRATA,    CRTPTOGAMIA,    MICROSCOPY,    ETC.  777 

stomach,  and  intestine  are  similarly  compressed  against  the  posterior 
wall.  The  compression  of  these  organs  is  so  great  as  seemingly  to 
preclude  their  functional  action,  the  stomach  appearing  to  be  quite 
incapacitated  for  its  normal  office  of  digestion.  Yet  the  continued 
vitality  of  the  ant  is  sufficient  evidence  that  alimentation  must  still 
exist ;  and  as  it  is  not  at  all  probable  that  the  crop  could  assume  the 
function  of  a  digesting  organ  without  injury  to  its  stores,  it  seems  as 
if  some  of  the  liquid  food  must  make  its  way  into  the  stomach  and 
intestine,  despite  their  extreme  compression,  and  be  there  prepared 
for  aliment. 

It  is,  in  fact,  a  puzzling  question.  Dr.  McCook  is  inclined  to 
think  stomach  digestion  in  some  instances  impossible.  But  the  con- 
tinued vitality  of  the  ant  seems  to  render  it  necessary,  despite  its 
apparent  impossibility. 

Structure  of  the  Lampyridae  with  reference  to  their  Phos- 
phorescence.*— The  Eev.  H.  S.  Gorham  arrives  at  the  conclusion 
that  the  sexual  instinct  has  played  a  large  part  in  moulding  the 
external  structure  of  this  group  of  beetles,  and  that  it  is  to  that  we 
may  look  for  an  adequate  explanation  of  the  development  of  phos- 
phorescent light,  though,  perhaps,  not  for  its  origin. 

In  the  first  place,  it  is  to  be  observed  that  all  the  species  of  this 
family  do  not  j)ossess  the  luminous  faculty  in  equal  degree  ;  but  that 
on  the  contrary,  while  some  are  highly  luminous  in  both  sexes,  some 
are  only  highly  so  in  the  female,  some  are  not  luminous  in  either 
sex,  and  some  (though  this  appears  rather  doubtful)  are  luminous  in 
the  males,  and  not  so,  or  much  less  so,  in  the  female. 

The  part  which  this  faculty  of  emitting  light  plays  in  the  economy 
of  nature  has  been  long  and  earnestly  debated.  The  most  general 
view,  and  one  which  the  author's  observations  tend  to  confirm,  is  that 
it  serves  as  a  beacon  to  attract  the  male  to  the  female ;  but  he  believes 
this  to  be  the  case  only  in  a  special  sense  in  those  species  which  do 
not  assemble,  and  especially  in  those  in  which  the  females  are  in- 
capable of  flight.  In  other  cases  he  believes  that  both  sexes  are 
attracted,  and  enabled  by  this  means  to  assemble  at  niglit  for  their 
union.  These  inferences  are  drawn  from  the  consideration  of  the 
relative  development  of  the  eyes,  together  with  what  is  known  of  the 
habits  of  the  various  species. 

The  eyes  of  the  Lampyridae  are,  he  finds,  developed  in  magnitude 
according  to  the  amount  of  luminosity  of  the  species  considered  ;  and 
the  other  parts  which  he  has  taken  account  of,  together  with  these, 
are  the  antennte,  of  which  there  is  a  very  great  diversity,  both  between 
the  sexes  and  in  the  genera ;  the  elytra,  which  are  also  subject  to 
sexual  and  generic  limitations,  and  finally  the  size  of  the  abdomen  in 
the  female. 

The  last-mentioned  is  no  doubt,  as  in  other  apterous  females,  the 
result  of  an  increased  production  of  ova.  These  are  in  the  Lam- 
l»yridto  laid  on  roots  and  other  substances  near  the  grouml,  where  the 

♦  'Trans.  Entomol.  Soc.  Lond.,'  1880,  [>\t.  G3-<;. 


778  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

young  larvae  will  at  once  be  likely  to  meet  with  their  mollnscan  diet. 
The  greater  the  tendency  to  produce  ova  in  abundance  the  more 
sluggish  the  females  would  become,  and  hence  females  once  capable 
of  flight  would  lose  the  use  of  their  wings,  and  the  usefulness  of  the 
light  to  attract  their  more  volatile  partners  would  be  greater  than 
ever.  This  he  believes  to  be  the  explanation  of  the  fact  that  the 
highest  degree  of  light,  or  at  any  rate  the  greatest  disproportion  in 
the  amount  shown  by  the  sexes,  is  to  be  found  in  those  species  which 
have  apterous  females,  and  together  with  this  the  greatest  develop- 
ment of  eye  in  the  male. 

The  species  in  which  both  sexes  are  winged,  and  in  which 
both  are  luminous  and  in  probably  nearly  equal  degree,  are,  the 
author  thinks,  by  far  the  larger  proportion  of  the  whole  number  of 
existing  species.  In  this  case  the  power  of  emitting  light  would  be 
obviously  useful  in  attracting  both  sexes  to  assemble  in  swarms,  and 
it  does  not  militate  against  this  supposition  that  in  many  siDCcies  the 
males  should  possess  this  faculty  in  the  higher  degree.  It  might  be 
anticipated  that  if  the  female  has  to  be  guided  to  the  rendezvous  of 
the  species  by  this  eilect,  the  eyes  in  that  sex  would  not  be  inferior 
to  those  of  the  male ;  and  such  is  the  fact.  One  well-known  case  is 
the  European  and  Eastern  genus  Luciola.  Here  both  sexes  fly,  both 
are  luminous,  and  both  have  largely  developed,  powerful  eyes. 

Neither  of  these  sections,  however,  comprise  those  species  which 
are  generally  regarded  as  most  tyjjical  of  the  family,  the  largest,  and 
those  which  appear  on  the  whole  to  have  all  their  parts  most  highly 
specialized,  and  which,  therefore,  we  place  at  the  head  of  a  systematic 
list,  such  as  the  genera  Lamprocera  and  Cladodes.  It  is  rather  re- 
markable that  in  these  genera  the  light-emitting  faculty  has  not  been 
developed  in  the  same  proportion  as  the  rest  of  the  organs  have,  and 
that  while  one  of  these,  viz.  the  eyes,  are  also  reduced  in  a  direct 
ratio  with  the  light,  and  are  small  and  uniform  in  both  sexes, 
another  organ,  the  antennae,  is  developed  in  inverse  ratio  as  the 
phosphorescence  is  diminished.  It  is  not  intended  to  refer  to  mere 
length,  or  redundancy  in  the  number  of  joints,  which  are  more  usual 
in  very  simple  and  primitive  forms  of  the  organ,  such  as  we  see  in 
JBlatta,  but  of  a  high  degree  of  specialization,  testified  by  large 
lamellar  plates  or  pectination.  Whether  the  eye  is  develoj)ed  at  the  - 
expense  of  the  antenna,  and  is  so  to  speak  the  recei^tacle  of  all  the 
vital  forces  of  the  head,  or  whether  the  antenna  supj)lements  the  loss 
of  the  other  organ  of  sense,  and  is  useful  in  detecting  the  presence  of 
the  female,  only  one  fact  is  in  evidence,  which  is  that  this  j)lumosity 
of  the  antennas,  in  one  case,  and  this  enormous  development  of  the 
eye  in  the  other,  are  usually  sexual  characters  predominating  in  the 
male,  but  sometimes  found  in  both  sexes. 

In  support  of  his  view  Mr.  Gorham  exhibited  a  selection  of  species 
arranged  in  three  groups,  viz. : — 

i.  Species  with  plumose  antennae,  small  or  moderate  eyes,  both 
sexes  winged,  light-emitting  surface  confined  to  one  or  more  small 
spots : — Lamprocera,  Cladodes,  Vesta,  Lucidora,  Phcenolis,  and  Megalo- 
phthalmus. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  779 

ii.  Species  in  which  both  sexes  are  winged  ;  light  emitted  con- 
siderable, sometimes  greater  in  the  P  ;  eyes  large,  sometimes  ex- 
cessive ;  antennae  simple,  usually  filiform  : — Cratomorphus,  Lucernula, 
Aspidosoma,  Luciola,  and  Plioturis. 

iii.  Species  in  which  the  female  is  apterous  or  with  rudimentary 
wings ;  light  emitted  often  very  great  in  the  female,  and  often  only 
rudimentary  traces  of  it  in  the  male  ;  antennae  usually  rudimentary  ; 
eyes  large  in  the  male,  often  excessively  so,  occupying  nearly  the 
whole  head  : — Pleotomus,  Lamprophorus,  MicropTiotus,  Lampyris,  and 
LmnprorMza. 

In  the  discussion  *  which  followed  the  paper,  the  author,  in  reply 
to  a  question  how  he  had  deterinincd  the  intensity  of  the  light  without 
actual  photometric  measurement  of  the  live  insects,  stated  that  tlie 
light-emitting  segments  at  the  extremity  of  the  abdomen  were  dis- 
tinguisliable  by  their  white,  vitreous  appearance,  and  that  he  con- 
sidered their  number  and  size  to  indicate  the  phosphorescent  power. 
He  did  not  consider  that  these  vitreous  segments  were  themselves 
luminous,  but  that  the  source  of  light  was  within  the  body  of  the 
insect,  and  shone  through  the  transparent  segments,  or  could  be 
withdrawn  at  pleasure.  In  this  manner  he  thought  the  gradual 
extinction  or  intermittent  flashing  of  the  light  might  be  explained. 

Influence  of  Temperature  in  producing  Varieties  of  Lepi- 
doptera.t — G.  Dorfmcister  has  observed  a  specimen  of  Vanessa 
Atalanta,  stated  to  have  been  bred  from  a  pupa  of  the  year  before, 
with  the  lower  side  of  the  hind  wings  buff-coloured ;  he  therefore 
made  experiments  to  test  the  caiise  of  this  by  trying  to  breed  similar 
forms,  and  succeeded  in  producing  just  such  a  specimen  as  the  first. 
As  the  species  docs  not  naturally  pass  the  winter  in  the  pupa  state  in 
this  part  of  the  world,  many  puptc  were  killed  by  cold,  and  the  tem- 
perature at  which  they  thrive  was  discovered  in  the  course  of  the 
experiments.  The  variety  mentioned  was  obtained  among  tlie 
images  from  pupa?  which  had  become  pupre  at  10^  to  11^  Ii.,  and 
were  afterwards  kept  at  7^""  to  5.V"  R.,  and  some  varieties  resembling 
it  resulted  from  the  same  treatment ;  pupae,  however,  kept  at  from  1° 
to  2°  R.  either  died  or  furnished  crippled  images. 

Using  higlicr  temjieratures,  and  forcing  the  pupae  in  a  shorter 
time,  he  found  tliat  several  similar  varieties  were  i)roduccd,  the 
method  being  to  allow  the  pupation  of  the  caterpillars  to  take  i)laco 
between  7h^  and  ll'^  R.,  to  keep  the  pupae  from  three  to  seven  days 
at  the  same  temperature,  and  for  the  remaining  eighteen  to  thirty 
days  to  keep  tliem  in  a  room  of  sometimes  tolerably  low  temperature. 

With  Vitnessa  urticce  he  found  that  diminishing  the  warmtli  pro- 
duced stages  of  transition  to  the  Lai)hxnd  form,  Vanessa  levaiia,  how- 
ever, which  is  accustomed  to  pass  the  winter  as  pupa,  developed  no 
varieties  when  exposed  to  a  greatly  diininishod  toiiiperaturc. 

In  order  to  determine  the  exact  period  at  which  the  future 
colourings  and  markings  are  fixed  on  the  insect,  he  recalls  the  fact 

*  Iliiil.  (Proc),  p.  vi. 

t  'MT.  Nivtvirw.  Vit.  Stciuriimrk  '  (IXSO),  Al.liaii.ll.,  \k  3.  I  pliilo. 


780  RECORD    OF    CURRENT   RESEARCHES    RELATING   TO 

that  the  most  extreme  varieties  resulted  from  larv^  which  had  been 
kept  in  the  cellar  (i.  e.  at  a  low  temperature)  during  their  period  of 
pupation ;  but  from  his  other  experiments,  and  from  some  recorded 
by  Professor  Weissmann,  he  is  now  inclined  to  believe  that  this 
critical  period  occurs,  not  at  the  time  of  the  pupation  itself,  but 
immediately  after  it. 

With  regard  to  the  known  sensitiveness  of  Lepidoptera  to  low 
temperatures  while  entering  the  pupa  stage,  he  states  that  larvae  of 
Arctia  caja  need  at  least  9°  to  10°  R.  for  this  operation ;  some  kept 
at  a  degree  varying  between  8°  and  10°  took  from  twenty -four  to 
thirty  days  to  make  the  change  after  spinning  up,  and  then  only 
produced  somewhat  deformed  images ;  those  kept  below  that  tem- 
perature perished. 

Protective  Attitude  of  the  Caterpillar  of  the  Lobster  Moth.* — 

Most  entomologists  have  admitted  that  the  grotesque  attitude  of  those 
caterpillars  forming  Newman's  "  Cuspidate  "  group  was  in  some  way 
protective,  but  it  is  only  quite  recently  that  Dr.  Hermann  Miiller 
has  made  known  the  results  of  his  observations  on  the  caterijillar  of 
Stauropus  Fagi,  which  observations  now  for  the  first  time  tend  to 
show  the  true  meaning  of  this  attitude  in  the  species  in  question. 

When  sitting  on  a  twig  in  its  natural  position  the  head  and  first 
five  segments  are  held  erect,  and  the  greatly  lengthened  legs  of  the 
Becond  and  third  segments  held  outstretched ;  thus,  when  seen  from 
the  front,  the  whole  aspect  of  the  insect,  both  in  form  and  colour,  is 
most  spider-like,  and  when  alarmed  it  immediately  raises  its  four  long 
legs  and  moves  them  irregularly,  after  the  manner  of  a  spider  attacking 
its  victim.  This  spider-like  appearance  is  believed  to  be  a  special 
protection  against  ichneumons  which  may  approach  it  from  the  front. 
According  to  the  experience  of  H.  Miiller  ichneumons  are  especially 
afraid  of  spiders,  and  he  states,  on  the  authority  of  Fleddermann,  an 
experienced  breeder  of  insects,  that  the  larva  oi  S.  Fagi  was  never  found 
to  be  attacked  by  ichneumons,  whilst,  according  to  Treitschke,  the 
nearly  allied  Hyhocampa  Milliauseri  is  often  attacked  by  them,  although 
a  much  rarer  species,  which  rarity  may  perhaps  be  attributable  to 
the  complete  absence  of  such  protection  as  that  possessed  by  S.  Fagi. 

So  much  for  the  front  aspect  of  the  caterpillar  under  consideration. 
When  approached  from  the  rear  there  is  nothing  to  be  seen  but  the 
erect,  hard  shield-like  surface  of  the  last  segment  surmounted  by  two 
black  horns,  and  presenting  an  appearance  totally  unlike  that  of  a 
caterpillar.  When  a  side  view  of  the  larva  is  presented,  there  is 
seen  on  the  fourth  and  fifth  segments  a  small  black  depression  just 
below  the  spiracles,  and  giving  the  appearance  of  a  caterpillar  ivhich 
has  been  stung  hy  an  ichneumon,  so  that  one  of  these  foes  approaching 
from  the  side  would  be  deceived  and  abandon  it  without  depositing 
its  eggs. 

Odoriferous  Apparatus  of  Sphinx  ligustri.t  —  This  has  been 
lately  discovered  by  Von  Eeichenau,  who  found,  while  stuflSng  the 

*  '  Kosmos,'  1879,  p.  123.     See  '  Trans.  Entom.  Soc.  Lond.,'  1880, '  Proe.,'  p.  iii. 
t  '  Entomol.  Naclir.,'  vi.  (1880)  p.  141. 


INVERTEBRATA,    CRYPTOGAMIA,   MICROSCOPY,   ETC.  781 

abdomen,  a  bunch  of  colourless  bair-like  scales  lying  in  a  fold  on 
eacb  side  of  the  first  abdominal  segment ;  it  could  be  extruded  from 
the  fold  by  pressure.  The  aperture  has  the  form  of  a  cylindrical  tube, 
and  here  a  strong  musky  scent  was  perceptible,  and  did  not  occur 
elsewhere.     The  scales  are  readily  visible  with  the  naked  eye. 

Spinning  Organs  of  Insect  Larvae.* — Dr.  Gustav  Joseph  has  a 
preliminary  communication  on  these  organs.  He  finds,  in  oppo- 
sition to  Lidth  de  Jeude,  that  they  are  supplied  with  nerves  from 
the  sub-oesophageal  ganglia  and  from  the  gastric  nervous  system. 
When  the  integument  is  carefully  removed  from  young  larvae  in 
which  the  fatty  body  is  but  slightly  developed,  it  may  be  seen  that 
between  the  peritoneal  investment  of  the  spinning  tube  and  its 
glandular  cell-layer  there  is  a  distinct  nervous  plexus  formed  of 
extremely  fine  dichotomous  filaments  which  pass  in  between  the 
gland-cells. 

These  spinning  organs  are  developed  very  early  in  the  course 
of  existence,  and  commence  as  a  small  depression ;  this  gradually 
deepens  and  becomes  converted  into  a  tube  ;  the  cells  which  bound 
its  lumen  are  at  first  scarcely  to  be  distinguished  from  the  morpho- 
logical elements  which  make  up  the  outermost  layer  of  the  general 
integument.  These  tubules  generally  make  their  appearance  before 
the  salivary  glands,  but  this  is  not  always  the  case.  The  author, 
in  opposition  to  Hatschek,  woiald  regard  them  as  being  tegumentary 
glands,  or  in  other  words  as  being  primarily  difi'erentiatcd  from 
the  integument.  They  are  not  to  be  confotmded  with  the  salivary 
glands,  the  function  of  which  is  in  relation  to  the  ingested  nutri- 
ment ;  and  they  themselves  demonstrate  their  relations  to  the  integu- 
ment by  forming  a  secretion  which  hardens  on  exposure  to  the  air, 
and  has  some  of  the  characters  of  a  cuticle. 

As  is  briefly  pointed  out,  the  development  of  the  three  constituent 
parts  of  the  tube — gland,  reservoir,  and  efferent  duct — diflers  in 
different  species.     Further  details  are  promised. 

Parthenogenesis  in  Halictus.f — The  observations  of  M.  Fabro 
have  been  chiefly  made  on  Halictus  cylindricus  and  H.  sexcinctiis. 
After  a  description  of  the  conditions  under  which  he  observed  the  two 
species,  the  author  points  out  tliat  for  this  genus  there  is  no  "society" 
in  the  entomological  sense  of  the  word  ;  each  mother  cares  only 
for  its  own  larvaj,  though  the  various  jiarents  unite  to  form  a  common 
liome  ;  each  cell  in  the  gallery  is  nevertheless  the  property  of  a 
single  Halictus.  As  to  the  relations  of  the  sexes,  wo  find  that  males 
are  very  rarely  to  be  detected  ;  in  September,  however,  they  are  to  bo 
found  in  quantity.  Beginning,  then,  with  the  month  of  November, 
wo  find  females  which  have  evidently  been  fertilized  ;  this  is  easy 
to  understand,  but  at  this  ptriod  tlio  males  have  completely  dis- 
appeared. The  females  pass  the  winter  in  their  cells,  and  towards 
]\Iay  they  come  out  and  work  at  their  nests.  In  July,  though  no 
males  have  yet  been  seen,  there  is  a  second  generation  ;  but  hero 

•  '  Zmil.  Anzcig.,'  iii.  (1S80)  p.  326. 
t  '  Ann.  Sci.  Nat.,'  ix.  (1880)  Art.  1. 


782  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

comes  the  difficulty,  that  we  know  that  the  females  die  down  after 
having  taken  steps  for  the  continuance  of  the  race  ;  and  again,  what 
have  become  of  the  numerous  females  developed  in  May,  if  it  is 
really  true  that  the  presence  of  the  males  is  necessary  for  the  forma- 
tion of  ova  capable  of  development  ?  "  They  are  mothers,  and  fertile 
mothers,  without  having  known  the  male."  The  generation  in  July 
is  therefore  a  true  case  of  parthenogenesis.  The  results  of  these  ova 
are  male  and  female,  and  the  members  of  the  former  sex  are  in  greater 
abundance.  Excepting  the  Aphides,  this  would  appear  to  be  the  first 
well-authenticated  case  of  the  alternate  development  of  fertilized  and 
of  non-fertilized  ova  among  the  Insecta  ;  the  cases  of  Lepidoptera 
which  might  be  brought  to  bear  upon  the  point  are  sporadic  and 
accidental. 

The  author  concludes  with  a  notice  of  a  parasite  on  E.  sexcindus, 
which  is  the  larva  of  Myiochjtes  subdipterus,  a  coleopteron  with 
greatly  reduced  elytra.  As  soon  as  the  larva  of  Halictus  has 
swallowed  its  honey,  it  is  devoured  by  Myiodytes  ;  as  to  the  depo- 
sition of  the  ova  of  this  last,  the  author  has  at  present  nothing  to 
communicate. 

Galls  produced  by  Aphides.* — In  this  paper  M.  Courchet  deals 
with  the  principal  galls  produced  by  aphides,  from  the  trijile  point 
of  view  of  their  development,  their  morphological  value,  and  their 
structure. 

He  abstains  from  discussing  the  action  that  the  puncture  exercises 
on  the  vegetable  tissues  ;  but  he  points  out  that  if  mechanical  influence 
could  take  any  part  whatever  in  the  formation  of  galls  it  would  cer- 
tainly be  in  those  of  the  aphides,  the  insect  being  always  alive  and 
active  in  the  heart  of  the  new  tissues.  Further,  the  action  of  the 
animal  poison,  to  which,  according  to  M.  Lacaze-Duthiers  and  others 
is  attributed  the  production  of  the  galls,  is  not  absolutely  comparable 
to  that  of  a  virus  on  animal  tissues  ;  the  latter  has  no  need  to  be 
inoculated  and  incessantly  renewed  to  give  rise  to  the  production  of 
special  phenomena,  whilst  M.  Courchet  has  always  observed  that  the 
galls  (of  aphides),  which  for  any  cause  have  been  abandoned  by  their 
inhabitants,  are  arrested  in  their  growth. 

M.  Courchet  passes  in  review  the  galls  of  the  Terebinth,  the 
Lentisk,  the  Black  Poplar,  and  the  Elm,  dwelling  particularly  on 
the  first  three,  which  are  the  most  interesting  and  the  least  studied. 

Of  the  Terebinth,  five  galls  are  described  :  horn  galls  (galle  en 
corne),  produced  by  Pempliigus  cornicularius,  and  utricular  galls  by 
P.  utricularius,  both  formed  at  the  expense  of  the  tissues  of  the 
median  nervure.  The  three  others  are  formed  by  the  lamina  of  the 
leaf  folded  in  different  ways,  and  are  the  production  of  P.  j^allidus, 
P.follicularius,  and  P.  semilunarius. 

On  the  Lentisk  is  found  one  gall,  produced  by  an  Aploneura,  and 
which  is  similar  to  those  of  P.  pallidus  and  P.  follicularius. 

The  Black  Poplar  has  six  galls ;  one  formed  at  the  expense  of  the 
tissues  of  a  branch,  the  others  being  of  a  foliar  nature.     They  are 

*  '  Rev.  Sci.  Nat.,'  i.  (1880)  pp.  533-41. 


mVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  783 

produced   by  the  followiug   insects  :    P.  sjnrothecce  (gall  formed   of 
the  twisted  petiole),  Pacliypaiypa  marsupialis  (gall  in  the  form  of  a 
purse,  generally  red  and  compressed  laterally,  projecting  from  the 
upper  side  of  the  leaf).  Pemphigus  bursariiis  (gall  growing  either  on  a 
branch  or  a  petiole),  P.  populi  n.  sp.  (gall  insufficiently  studied,  but  it 
is  believed  that  the  tissues  of  the  median  nervure  take  the  greatest 
part  in  its  constitution),  P.  affinis  (hardly  to  be  considered  a  "  gall," 
consisting  simply  of  a  folding  of  the  leaf  on  the  median  nervure,  the 
right  and  left  margins  meeting  and  forming  a  large  cavity  between 
the  two  parts  of  the  leaf),  P.  vesicarius  (gall  possibly  resulting  from 
the  union  and  abnormal  growth  of  the  leaves  of  a  bud). 
The  following  are  M.  Courchet's  conclusions : — 
1st.  None  of  the  galls  produced  by  the  aphides  arise  from  the 
very  centre  of  the  tissues  of  an  organ ;  some  commence  by  a  simple 
invagination  of  the  lamina  of  a  leaf  ("  horn  gall,"  utriculate  gall  of 
the  Terebinth),  or  by  a  cellular  swelling  which  forms  and  rises  little 
by  little  around  the  insect  as  in  the  gall  of  Pemyliigns  bursarius  of 
the  Black  Poplar ;  or  again,  a  petiole  coiled  up  on  itself  encloses  the 
insect  in   a  cellular  utricle   which  finally   becomes  a  true   gall,  as 
happens  in  the  case  of  P.  spirothecce,  &c.  ;  in  other  words,  all  may  be 
classed  under  M.  de  Lacaze-Duthiers'  term  of  "  false  internal  galls." 
2nd.  Their  cavity  is  always  spacious,  and  the  wall  relatively  thin, 
which  is  rendered  necessary  by  the  presence  in  their  interior  of  an 
always  considerable  number  of  living  insects. 

3rd.  Their  structure  always  retains  more  or  less  of  that  of  the 
organ  which  bears  them,  and  which  is  entirely,  or  in  part,  transformed 
to  j)roduce  them.  In  general  their  walls  are  composed  of  a  tolerably 
homogeneous  fundamental  cellular  tissue,  which  is  traversed  by  fibro- 
vascular  bundles  in  variable  number.  There  are  no  well-marked 
concentric  layers  here,  as  seen,  for  instance,  in  the  galls  produced  by 
Cynips  on  the  oak. 

4th.  All  the  galls  of  aphides  hitherto  observed  by  the  author, 
with  one  exception,  represent  appendicular  organs,  or  parts  of 
appendicular  organs  transformed ;  the  gall  of  Pemphigus  bursarius 
alone  is  formed  laterally  on  an  axis  or  petiole  by  a  single  prolifera- 
tion of  the  herbaceous  layer,  and  in  an  independent  manner. 

/3.  Myriapoda. 

Eyes  and  Brain  of  Cermatia  forceps.* — Mr.  N.  Mason  lias  made 
preparations  of  the  eyes  of  this  Myriapod,  which  is  useful  as  a  sjjider- 
destroyer,  and  Dr.  Packard  gives  the  result  of  his  examination  of  tho 
eyes  and  brain. 

The  eye  appears  to  be  constructed  on  tho  same  plan  as  that  of 
other  species  of  tho  sub-class,  but  differing  in  important  resjiccts. 
Though  Cermatia  is  said  to  have  compound  eyes  in  contradistinction 
from  the  so-called  "  ocelli  "  of  other  Myriapods,  the  latter  arc  like- 
wise truly  aggregated  or  compound,  tho  "  ocelli "  being  composed  of 
contiguous  facets,  tho  nerve-fibres    supplying  them  arising   in   tho 

♦  '  Am.  Nut.,'  xiv.  (1880)  i\  C02. 


784  KECORD   OF    CURRENT   RESEARCHES    RELATING   TO 

same  general  manner  from  the  optic  nerve  as  in  Cermatia,  wliere  tlie 
facets  are  much  more  numerous.  The  eye  of  Cermatia  is  composed  of 
a  hemispherical,  many-facetted  cornea,  the  lenses  of  which  are 
shallow,  doubly  convex,  being  quite  regularly  lenticular,  the  chitinous 
substance  being  laminated  as  usual.  Each  corneal  lens  is  underlaid 
by  a  retina  about  as  thick  as  the  cornea,  the  inner  surface  of  each 
retinal  mass  being  convex.  Corresponding  to  each  lens  is  a  separate 
mass  of  connective  tissue,  which  increases  in  thickness  from  the  end 
of  the  optic  nerve  outward  towards  the  cornea ;  though  the  entire 
retina  of  the  eye  extends  back  to  the  ganglion  opticum.  Within  the 
broad  stratum  of  connective  tissue,  forming  the  entire  retina  of  the 
eye,  lies  next  to  the  corneal  lens  a  layer  of  "  vitreous  cells  "  or  "  lens- 
epithelium  "  of  Graber.  This  layer  is  succeeded  by  the  series  of 
rather  large  visual  rods,  one  in  each  mass  corresponding  to  each 
corneal  lens ;  these  rods  are  long  and  sharp,  conical  at  the  end  which 
extends  nearly  to  the  inner  edge  of  the  retinal  mass  ;  they  each 
possess  a  nucleus,  and  the  connective  tissue  enveloping  the  rods  is 
nucleated,  while  there  is  an  irregular  layer  of  nucleated  cells  near  or 
around  the  ends  of  the  rods.  There  are  no  cones ;  these  not  being 
yet  detected  in  the  eye  of  Myriapods.  This  layer  of  cells  is  suc- 
ceeded by  a  thin,  slightly  curvilinear,  transverse  strip  of  connective 
tissue  passing  through  the  entire  eye,  and  behind  it  are  the  loose, 
nucleated,  spherical  cells  forming  the  ganglion  opticum. 

The  brain  of  Cermatia  forceps,  as  shown  by  several  sections,  is 
developed  on  the  same  plan  as  in  Bothropolys,  and  the  myriopodan 
brain  seems  to  correspond  more  closely  in  its  general  form  and 
histology  with  that  of  the  insects  than  the  Crustacea.  The  large, 
thick  optic  nerve  arises  from  the  upper  side  of  each  hemisphere.  The 
median  furrow  above  is  deep,  and  on  each  side  is  a  mass  of  small 
ganglion  cells ;  also  a  mass  in  the  deep  fissure  below  the  origin  of 
the  optic  nerve,  and  another  mass  on  the  inferior  lobe  extending 
down  each  side  of  the  cesophagus,  probably  near  or  at  the  origin  of 
the  posterior  commissure.  These  masses,  i.  e.  those  on  the  upper  and 
under  side  of  the  brain,  connect  on  each  side  of  the  median  line,  and 
in  this  respect  the  brain  is  as  in  Bothropolys.  There  are  no  large 
ganglion  cells  as  in  Crustacea,  including  Limulus. 

There  is,  then,  no  very  close  resemblance  in  form  or  histology 
between  the  eye  and  brain  of  Limulus  and  the  Myriapods,  the  two 
types  of  eye  being  essentially  diiferent. 

7-  Arachnida. 

New  "Work  on  Parasites. — M.  P.  Mequin  has  just  published 
a  work  entitled  '  Les  Parasites  et  les  Maladies  Parasitaires.'  The 
part  which  has  already  appeared  deals  with  the  parasitic  Arthropoda. 
In  addition  to  the  sixty-three  woodcuts  which  are  intercalated  in  the 
text,  there  is  a  separate  atlas  of  twenty-six  plates.  This  work  ought 
to  be  useful  as  a  dictionary  and  handbook  of  the  characters  of  the 
more  important  Arthropod  j^arasites,  for  though  not  without  faults 
it  goes  a  long  way  to  supply  a  want  which  has  been  long  felt. 


DTVERTEBRATA,    CRTPTOGAMIA,    MICROSCOPY,    ETC.  785 

New  Galeodida.* — In  his  latest  contribution  to  this  subject, 
Dr.  Karsch  describes  a  number  of  new  forms,  and  among  these  there 
are  three  new  genera — Zerhina  {Z.  gracilis  C.  L.  Koch),  Dcesia 
(D.  prcecox  C.  L,  Koch),  Biton  (B.  Ehrenbergii  n.  sp.),  and  Gnosippus 
(G.  Klunzingeri  n.  sp.).  The  author  is  of  opinion  that  the  time  has 
not  yet  come  for  a  natural  arrangement  of  this  group.  Simon,  in 
rejecting  what  he  regards  as  Koch's  artificial  arrangement,  has  left 
equally  important  points  out  of  consideration.  In  proof  of  his 
position  the  author  gives  an  interesting  table  showing  the  number  of 
tarsal  joints  in  the  three  hinder  pairs  of  legs  in  the  genera  of  the 
Galeodida,  which  shows  up  the  lacuna?  in  our  knowledge  in  a  very 
striking  manner. 

5.  Crustacea. 

Antennary  Gland  of  the  Crustacea.t — In  this  important  essay 
Dr.  Grobbeu  commences  with  an  account  of  his  observations  on 
some  of  the  Phyllopoda ;  in  the  larva)  of  Esfheria  and  Branchipus  he 
has  found  that  in  its  early  condition  the  gland  consists  of  two  parts, 
histologically  different ;  there  is  a  terminal  saccule,  and  a  urinary 
canal,  looped  and  coiled.  The  former  lies  between  the  muscles  of 
the  second  antenna  and  has  a  dorso-ventral  direction  ;  it  is  attached 
to  the  integument  by  connective  fibres.  The  canal  extends  from 
before  backwards,  and  opens  at  the  base  of  the  second  antenna.  The 
saccule  is  lined  by  an  epithelial  layer  lying  on  a  delicate  supporting 
membrane  ;  the  cell-protoplasm  is  clear,  rich  in  vacuoles  and  nume- 
rous yellowish-brown  granules.  In  the  canal  we  only  find  three 
nuclei,  so  that  its  walls  are  formed  by  three  cells  ;  the  protoplasmic 
granules  are  principally  arranged  in  cords,  while  on  the  internal 
surface  the  cells  are  invested  by  a  rather  thick  cuticle. 

In  the  Nauplius  form  of  Cetochihts  hehjolandicus  the  canal  is 
formed  by  a  few  cells,  the  terminal  saccule  by  a  single  one,  and  it  is 
provided  on  its  inner  surface  with  a  delicate  cuticle.  In  Cyclops 
(Nauplius  form)  the  antennary  gland  is  considerably  elongated,  the 
canal  is  long,  curved  dorsally,  and  after  a  complex  course  returns  to 
the  region  of  the  saccule. 

Turning  from  the  Entomostraca  to  the  Malacostraca,  the  author 
describes  what  he  has  seen  in  Gammarus  marinns ;  here,  again,  there 
is  a  terminal  saccule  and  a  canal  ;  the  former,  reniform  in  shape,  lies 
near  the  integument,  and  the  canal  after  several  coils  returns  to  open 
near  it.  The  protoplasm  in  the  cells  of  the  former  is  coarsely 
granular,  and  in  tlie  latter  finely  fibrillatcd ;  its  terminal  portion  has 
special  cells,  which  completely  resemble  the  matrix-cells  of  the 
integument,  and  they  shed  out  a  chitinous  cuticle  ;  to  this  portion  of 
the  "  urinary  canal  "  the  author  applies  the  term  of  "  ureter." 

After  giving  a  description  of  tlie  same  parts  in  ^Fysis,  Dr. 
Grobben  comes  to  the  so-called  "  green  gland  "  of  the  Dccapoda  ;  in 
Pdhemon  trcillianus  the  gland  lies  in  the  basal  joint  of  the  second 
antenna ;  the  saccule  is  reniform  and  is  supplied  by  a  large  blood- 
vessel ;  the  whole  course  of  the  canal  was  not  exactly  followed,  and 

*  '  Arch,  fur  Nntnrg.,'  xlvi.  (1880)  p.  228. 
t  '  ClauH's  Arboitcn.'  iii.  (ISSO)  p.  m. 
VOL.    III.  3    F 


786  RECORD    OP   CURRENT    RESEARCHES   RELATING   TO 

it  will  be  useless  here  to  describe  the  numerous  loops  that  it  makes. 
As  to  the  minuter  details,  we  are  told  that  the  saccule  is  not  a  simple 
sac  with  smooth  walls,  but  that  it  consists  of  a  large  number  of  csecal 
sacs,  between  which  there  is  a  rich  network  of  connective  tissue,  in 
the  lacunae  of  which  the  blood  can  freely  circulate.  The  cells  have 
large  nuclei,  and  pale,  finely  granxilar  contents ;  on  the  other  hand, 
in  the  canal  the  cell-contents  are  arranged  cord-wise,  and  are  best 
developed  on  the  side  of  the  cell  most  distant  from  the  lumen.  The 
thick  cuticle  is  likewise  striated,  and  in  a  direction  perpendicular  to 
the  axis  of  the  canal.  The  results  of  his  observations  on  the  green 
gland  of  Astacus  fluviatilis  do  not  altogether  agree  with  those  of 
previous  observers;  forming  a  compact  mass,  lying  largely  in  the 
thorax,  the  saccule  and  canal  are  still  to  be  distinguished  ;  the  former 
is  rounded,  and  of  a  yellowish-green  colour;  the  canal  is  delicate, 
provided  with  diverticula,  and  extended  into  a  wide  canal  of  a  pale 
greenish-grey  colour,  which  has  similar  diverticula,  and  which  lies 
coiled  between  the  saccule  and  the  green  part  of  the  canal ;  the 
terminal  portion  of  the  duct  is  here  again  lined  by  a  chitinous  cuticle. 
Deep  clefts  are  to  be  observed  between  the  epithelial  cells  of  the 
saccule,  and  the  protoplasm  is  seen  to  contain  a  number  of  amorphous 
yellow-green  bodies;  the  bright-green  portion  of  the  canal  has 
epithelial  cells  of  a  cubical  or  cylindrical  foi^m,  and  the  contained 
granules  are  arranged  cord-wise ;  there  is  a  thickish  cuticle,  thinner 
at  certain  points,  and  so,  in  optical  section,  appearing  as  though  it 
were  composed  of  rods.  The  author  insists  on  the  rich  supply  of 
blood-vessels  to  all  parts  of  the  canal. 

When  we  compare  these  results  with  what  we  know  of  the  shell- 
gland,  we  find  a  striking  resemblance  in  structure;  without  going 
here  into  this  subject  in  detail,  attention  may  be  directed  to  the 
conclusion  that  the  two  glands  have  a  similar  structure  ;  further,  the 
view  that  they  are  homologous  is  supported  by  the  fact  that  they  are 
both  mesodermal  in  origin.  As  to  the  functions  of  the  parts,  it 
would  seem  that  the  terminal  saccule  is  to  be  compared  to  the 
Malpighian  capsules  of  the  Vertebrate  kidney ;  while  the  canals  are 
comparable  to  the  tuhuli  contorti. 

In  both  Vermes  and  Mollusca  the  urinary  canals  are  formed  by 
a  few  cells,  and  the  difference  in  the  length  of  the  canal  in  Cyclops  as 
compared  with  Cetocliilus  is  to  be  explained  by  the  fact  that  one 
inhabits  fresh  and  the  other  salt  water,  just  as  the  marine  Polychaeta 
have  short,  and  the  fresh-water  Oligochaeta  long  segmental  organs. 

Rapidity  of  the  Transmission  of  Motor  Stimuli  along  the  Nerves 
of  the  Lobster.* — MM.  Fredericq  and  Vaudevelde  find  that  at  Ghent, 
at  a  temperature  of  10-12''  C.  (in  February  and  March),  this  rapidity 
was  about  6  metres  a  second ;  at  Eoscoff,  with  the  temperature  at 
from  18-20°  C.  they  attained  different  results,  the  rapidity  being 
from  10-12  metres  a  second.  Both  these  data  show  that  in  the 
lobster  stimuli  are  conveyed  along  motor  nerves  very  much  more 
slowly  than  they  are  along  those  of  the  frog  or  of  man. 

*  '  ComptcB  Rendus,'  xci.  (1880)  p.  239. 


INVERTEBRATAj    CRYPTOGAMIA,    MICROSCOPY,    ETC.  787 

Nervous  System  of  Idotea  entomon.*  —  This  Isopod,  selected 
for  study  by  M.  Ed.  Brandt,  has  three  cephalic,  seven  tlioracico- 
abdominal,  and  four  post-abdominal  nerve  ganglia.  Of  the  cephalic 
group,  the  supra-oesophageal  (not  that  so  called  by  Rathke,  which  is 
the  sub-cesophageal)  is  made  up  of  two  median  lobes,  the  hemispheres, 
sending  nerves  to  the  interior  antennse  ;  of  two  external,  the  optic, 
lobes,  giving  off  the  optic  nerves ;  and  of  two  antennary  lobes  supplying 
the  external  antennaj.  The  short  and  very  thick  oesophageal  collar 
gives  off  two  nerves  to  the  labrum.  The  sub-oesophageal  ganglion 
is  small,  and,  as  in  insects,  gives  off  three  nerve  jiairs,  to  the  labium, 
maxillfe,  and  mandibles  respectively.  The  third  cephalic  mass,  for 
which  the  name  lyedomaxillary  is  proposed,  rests  on  a  special 
pedomaxillary  plate,  and  from  it  proceeds  one  pair  of  nerves, 
similarly  named,  to  the  two  maxillipedes.  Of  the  ganglia  of  the 
main  body,  the  first  is  small,  but  larger  than  the  pedomaxillary,  and 
all  the  rest  arc  of  one  size ;  from  each  of  them  originates  a  nerve 
pair  to  the  feet,  while  the  commissures  between  them  supply  the 
muscles  and  integument  of  the  segment.  The  pedomaxillary  shows 
the  same  arrangement,  sending  off  nerves  to  the  posterior  part  of  the 
head  as  well  as  those  for  the  maxilliijedes.  It  would  seem  from  its 
innervation  and  the  presence  in  it  of  a  distinct  ganglion  that  the 
posterior  part  of  the  head  is  a  thoracic  segment  amalgamated  with 
the  head.  The  latter  therefore  forms  part  of  an  imperfect  cephalo- 
thorax,  but  is  still  morphologically  different  from  the  heads  of  insects. 
The  four  post-abdominal  ganglia  are  much  smaller  than  those  of 
the  body  ;  the  three  anterior  are  all  of  the  same  size,  and  give  off"  each 
a  single  nerve  pair  to  their  segments ;  the  fourth  is  larger,  and  four 
pairs  of  nerves  proceed  from  it.  An  azygos  sympathetic  trunk  lies 
here  between  the  commissural  cords  of  the  central  system,  and  is 
interrupted  by  ganglia  as  already  described  by  F.  Leydig  in  Purcellio 
scaler. 

Cymothoidae.  t — A  year  or  two  ago  a  request  was  sent  to  the 
various  museums  of  the  world  by  Drs.  Schiodte  and  Meinert,  of 
Copenhagen,  requesting  the  loan  of  all  specimens  of  Cymothoidfe 
(Isopoda)  for  the  pui-pose  of  monographing  the  group,  and  the  first 
portions  of  the  monograph  have  now  appeared. 

The  first  of  these  papers  treats  of  the  Cirolanidas,  which  closely 
resemble  the  true  Cymothoas,  but  which  differ  in  having  the  mouth- 
parts  adapted  for  eating  flesh.  Three  genera  and  nine  species  arc 
characterized,  of  which  the  genera  Baryhrotes  and  Tachaa,  and  species 
B.  iiulns,  B.  agilis,  T.  crassipes,  CoraUana  coUaris,  brevipes,  nodosa, 
and  hirsuta  are  new.  Each  species  is  described,  as  far  as  the  specimens 
permitted,  under  three  heads — male,  virgin,  and  ovigerous  females — 
the  difference  between  the  sexes  and  between  the  two  forms  of  the 
same  sex  being  very  striking. 

In  the  second  paper  the  iEgidic  are  monographed.  Those 
Crustacea  lead  a  parasitic  life,  generally  attaching  themselves  to  tlio 

♦  'Coiuptcs  Rcndus,'  xc.  (1880)  p.  7i:5. 

t  '  Nftt.  Tiddsk.,'  xii.  pp.  21'.)  nw\  .'J2I.     Sro  '  Am.  Nat.,'  xiv.  (18S0)  p.  510, 

3  F  2 


788  KECORD   OF   CURRENT   RESEARCHES   RELATING    TO 

roof  of  the  moutli  of  fishes,  and  with  their  modified  mouth-parts, 
which  form  a  sucking  tube,  living  on  the  blood  of  their  hosts.  These 
forms  are  described  under  the  following  generic  and  specific  names, 
those  marked  (*)  being  new: — ^ga  tridens,  Mrsuta*  crenulata, 
Wehhii,  Stroemii,  rosacea,  serripes,  psora,  Deshayesiana,  antillensis,* 
magnifica,  monoplitlialma,  nodosa,*  opJitlialmica,  tenuipes*  dentata,* 
incisa,*  ardica,  ventrosa  and  spongiophila,  Bocinela  danmoniensis, 
insularis,*  Dumerilii,  maculata,*  americana,*  orientalis,*  australis,* 
signata  *  and  aries,*  Alitropus  typus  and  foveolatus*  Full  descriptions 
are  given  of  the  male,  virgin,  ovigerous  female,  and  the  young.  The 
text  is  in  Latin,  and  there  are  plates. 

Ostracoda  of  Scotland.* — The  Natural  History  Society  of  Glasgow 
are  publishing  catalogues  of  the  fauna  of  Scotland,  with  special 
reference  to  Clydesdale  and  the  western  district,  and  amongst  them  is 
one  on  the  fresh  and  brackish-water  species  of  Ostracoda  by  Mr.  D. 
Eobertson. 

Forty-one  species  are  given,  of  which  three  are  new  (Cypris 
gramdata,  Candona  euplectella,  and  C.  nitens). 

Those  which  may  be  considered  to  belong  exclusively  to  brackish 
water,  but  never  by  choice  to  be  purely  marine,  are  Cypris  salina, 
Cypridopsis  aculeata,  Cytheridea  torosa,  and  its  variety  teres.  Cypris 
incongruens  and  Cypridopsis  obesa  are  frequently  found  in  brackish 
water,  but  as  frequently  in  purely  fresh  water. 

Many  other  species  are  occasionally  met  with  in  water  more  or 
less  brackish,  as  in  ponds  a  little  above  high-water  mark,  subject  to 
the  spray  of  the  sea  during  high  tides  and  storms,  but  chiefly  in  fresh 
water  quite  beyond  the  reach  of  marine  influences.  Eeference  is 
Hiade  to  a  group  of  small  ponds  lying  mostly  within  a  few  yards  of 
each  other  along  the  south-west  shore  of  the  island  of  Cumbrse,  only 
a  little  above  high-water  mark.  These  appear  to  be  subject  to  an 
equal  amount  of  sea-spray,  and  to  be  exposed  to  similar  conditions, 
yet  their  microscopic  fauna  are  found,  when  compared,  to  differ 
widely.  A  list  of  the  Ostracoda  found  in  ten  of  these  sub-brackish 
patches  of  water  shows  the  great  number  of  reputed  fresh-water 
species  associated  with  those  which  constantly  affect  brackish  water, 
and  also  the  diversity  in  the  numbers  and  grouping  of  species  existing 
between  one  pond  and  another.  This  mixtui-e  of  fresh  and  brackish- 
water  species  is  all  the  more  remarkable,  as  none  of  these  ponds 
communicate  with  the  others,  nor  with  any  fresh-water  stream. 

The  author  indicates  (1)  where  the  Ostracoda  are  principally  to 
be  found,  (2)  what  season  of  the  year  is  most  favourable,  (3)  by  what 
means  secured,  and  (4)  how  to  preserve  them.  We  can  only  give  a 
very  condensed  statement  of  the  author's  views  on  these  points,  and 
the  original  paper  should  be  referred  to. 

The  places  where  to  he  found  are  lakes,  tarns,  ponds,  lagoons, 
canals,  ditches,  and  often  in  very  small  patches  of  water,  and  in 
slow-running  streams;  but  in  the  latter  by  no   means  commonly, 

*  Appended  to  part  1  of '  Proc.  Nat.  Hist.  Soc.  Glasgow,'  iv.  (1880)  (separate 
title-page  and  paging). 


mVEKTEBRATAj    CRYPTOGAMIA,    MICROSCOPY,   ETC.  789 

except  in  weedy  recesses  protected  from  the  currents,  or  where  clumps 
of  thickly  growing  plants  abound.  They  are  more  abundant  in  the 
smaller  ponds  overgrown  with  weeds  than  in  deep  and  large  sheets  of 
water.  Even  in  damp  mud,  and  in  the  scanty  water  of  furrows  in  old 
pasture  land,  good  gatherings  are  met  with.  Where  the  pools  are 
small  and  subject  to  be  dried  up  during  summer,  they  seldom  contain 
many  species,  although  in  such  cases  one  species  may  prevail  greatly. 
Limestone  districts  are  favourable  to  Ostracoda,  but  all  rock  or  clay 
surfaces  are  better  than  peat.  Where  there  is  nothing  but  pure  peat, 
or  peaty  ponds  fringed  with  Sphagnum,  few  or  no  Ostracoda  may  be 
expected.  They  are  seldom  searched  for  successfully  where  the  lakes 
or  pools  have  risen  much  by  heavy  rainfalls,  nor  in  mill-dams,  where 
the  water  is  drained  off  rapidly,  leaving  broad,  bare  margins.  It  is 
otherwise  where  the  water  in  the  pools  is  decreasing  gradually  by 
evaporation.  Then  the  animals  appear  to  have  time  to  follow  the 
water,  and  may  be  taken  abundantly  when  thus  brought  closer  together 
in  the  small  shallow  pools  left  here  and  there.  Moorland  roadside 
ditches  are  more  promising  than  those  at  some  distance  from  the 
road.  This  may  arise  from  a  supply  of  material  from  the  drainage  of 
the  road,  which  may  be  requisite  to  build  up  the  shells  of  these 
minute  crustaceans.  They  are  seldom  absent  in  ditches  or  marshes 
which  contain  a  little  ochreous  deposit  with  a  metallic  bluish  scum  on 
the  surface  of  the  water ;  they  are  more  common  in  broad  shallow 
ditches  than  in  those  more  narrow  and  deep,  and  are  rarely  met  with 
in  springs  or  in  ponds  abounding  with  fish.  Neither  do  they  thrive 
where  Amphipods  prevail.  They  are  not  always  fastidious  in  their 
choice  of  habitat,  sometimes  disporting  in  pure  fresh  water,  at  other 
times  revelling  in  water  of  very  questionable  character ;  while  others 
affect  brackish  water,  although  they  live  in  very  different  degrees  of 
the  saline  element. 

The  best  time  for  collecting  is  of  course  the  summer,  during  sun- 
shine. Heat  is  conducive  to  theii"  increase  and  development.  In  a  hot- 
house tank  at  65^  F.,  Cypris  incongruens  abounded,  but  in  water  from 
the  same  source  at  a  lower  temperature  there  were  comparatively  few. 
Dr.  G.  S.  Brady  found  them  in  mill  cooling  ponds  at  100^  F.  They 
may  be  found,  however,  under  the  ice  in  winter. 

The  preferabL-  mode  of  collection  is  a  net  6  inches  (rather  than 
10  inches)  in  diameter  and  24  inches  deep — the  mesh  one  hundred 
threads  to  the  inch.  This  smaller  size  of  net  has  the  great  advantage 
of  admitting  conveniently  a  brass  wire  sieve  with  a  hoop  about  an 
inch  deep  to  fit  into  the  ring  of  the  muslin  net,  preventing  weeds 
and  other  coarse  material  from  getting  into  the  bag,  but  sufficiently 
open  to  allow  all  the  Microzoa  to  pass  through.  A  sieve  with  a 
^-inch  mesh  is  very  suitable.  Tins  protecting  sieve  requires  to  bo  lilted 
together  into  the  mouth  of  the  muslin  net,  so  as  not  to  fall  out  when 
working,  but  sufficiently  easy  to  be  taken  off  when  the  contents  of  the 
bag  are  turned  out.  For  security,  it  is  better  to  have  the  sieve  slung 
to  the  neck  of  the  handle  by  a  short  cord. 

To  work  the  net,  sinqily  sweep  it  through  the  vegetation  along 
the  margin  of  the  pond ;  this  done,  remove  the  sieve,  invert  the  bag. 


790  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

and  convey  the  contents  into  a  wide-moutlied  bottle,  &c.,  which  will, 
in  most  cases,  indicate  .whether  there  is  anything  worth  further  trial, 
though  it  often  happens  that  repeated  trials  afford  good  results  in  the 
same  jilace  where  they  had  failed  to  be  seen  by  the  first  inspection. 
The  Ostracoda  generally  withdraw  within  their  shells  and  become 
motionless  when  alarmed,  and  are  difficult  to  be  seen  in  this  state 
among  the  debris  of  the  gathering  ;  but  where  they  do  exist,  more  or 
less  of  them  come  to  the  surface,  and  are  readily  detected  in  an  open 
vessel,  but  equally  as  well  and  more  easily  by  examining  the  contents 
of  the  net  when  the  water  is  well  pressed  out.  To  have  the  full 
benefit  of  the  gathering,  it  is  necessary  to  take  some  of  the  mud, 
which  in  most  cases  can  be  readily  procured  by  scraping  the  sides  or 
bottom  of  the  pool  with  the  ring  of  the  net. 

The  mode  of  preservation  is  shortly  dealt  with,  as  Ostracoda 
require  no  sjjecial  appliances  for  preservation  so  far  as  the  shell  is 
concerned,  further  than  allowing  them  to  dry ;  but  when  the  animals 
are  wished  to  be  preserved,  alcohol,  with  the  addition  of  a  little 
glycerine,  is  preferable. 

Blind  Crustacean.*  —  M.  A.  Milne-Edwards  has  a  note  on  a 
blind  species  of  the  genus  Nephrojms  which  was  found  at  a  depth  of 
1500  metres  in  the  Gulf  of  Florida.  The  eyes,  which  are  situated 
just  above  the  internal  antennfe,  form  small  tubercles  without  cornesB  ; 
so  far  the  species  [N.  Agassizii)  resembles  the  N.  Stewarti  described 
by  Wood-Mason,  but  it  differs  from  it  in  the  greater  development  of 
the  rostrum  which  is  armed  with  two  pairs  of  lateral  spines,  by  the 
number  of  tubercles  on  its  carapace,  and  by  the  form  of  the  first  five 
abdominal  rings.  From  the  extremity  of  the  rostrum  to  the  end  of 
the  tail  the  new  species  measures  •  055  metre ;  the  integument  is 
completely  colourless. 

Vermes. 

Annelids  of  the  Norwegian  North  Sea  Expedition.! — Fifty-five 
sj)ecies  are  enumerated  by  G.  A.  Hansen  from  the  collections  ob- 
tained by  this  expedition,  among  which  there  are  4  new  species  of 
Polynoe  (P,  assimilis,  sjnnulosa,  foraminifera,  and  glaberrima),  a  new 
Phyllodoce  (P.  arctica),  a  new  Brada  (B.  granulosa),  and  three  new 
TropJioniai  (arctica,  horealis,  rugosa),  in  all  9  new  forms  out  of  the  55. 
Spinther  arcticus  is  figured,  apparently  for  the  first  time.  Polynoe 
glaberrima  bears  much  resemblance  to  Lcenilla  glabra  Ingr.,  but  the 
palps  are  quite  smooth,  the  tentacular  cirrhi  are  shorter  than  the 
palps ;  instead  of  two  bristles  at  the  base  of  the  tentacles,  a  single 
spine  occurs.  The  new  species  of  Phyllodoce  bears  most  resemblance 
to  P.  mucosa,  differing  from  it  chiefly  in  the  number  of  the  papillae 
on  its  prostomium. 

New  Genus  of  the  Archiannelides.;!: — Under  the  name  of  Pro- 
todrilus  Leuclmrti,  Dr.  Hatschek  describes  an  interesting  new  form 
which  he  found  near  Messina.    As  it  is  more  simple  even  than  Pohj- 

*  '  Ann.  Sci.  Nat.,'  ix.  (1S80),  Art.  2. 

t  '  Nyt  Mag.  Naturvid.,'  xxv.  (1880)  p.  224  (5  plates). 

i  '  Claus's  Arbeiten,'  iii.  (1880)  p.  79. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY^    ETC.  791 

gordius  it  is  almost  certain  that  it  is  the  very  lowest  of  all  known 
Annelides ;  the  points  in  which  it  is  lower  affect  chiefly  the  organiza- 
tion of  the  nervous  system,  the  characters  of  the  ventral  ciliary  groove, 
the  blood- vascular  system,  and  the  relations  of  the  midgut. 

These  little  worms  ("  Wurmchen  ")  are  of  yellowish- white  colour, 
and  the  sexually  mature  individuals  are  about  4  mm.  in  length ;  they 
creep  about  like  Nemertines,  and  locomotion  is  principally  effected  by 
cilia,  while  the  direction  they  take  appears  to  be  influenced  by  the 
longitudinal  muscles  of  the  body.  Their  general  appearance  is  very 
much  that  of  Polygordius,  the  elongated  body  exhibits  no  external 
segmentation,  the  ventral  surface  is  rather  flattened,  and  along  the 
trunk  there  is  a  deep  ciliated  groove.  The  cephalic  portion,  which  is 
somewhat  thicker,  has  two  flattened  contractile  tentacles  at  its  anterior 
end ;  the  hinder  end  is  narrower  and  notched.  Segmentation  is  ex- 
pressed by  the  five  boundary  lines  in  the  ectoderm,  by  the  ciliation,  as 
well  as  by  the  dissepiments  and  the  segmental  organs. 

The  cephalic  region  is  distinguished  by  the  possession  of  a  very 
large  post-oral  region,  similar  to  that  observed  in  Polygordius  and 
Saccocirrus.  The  number  of  trunk-segments  increases  during  the 
maturation  of  the  generative  products ;  22-31  segments  were  counted. 
The  last  segments  of  all  are  always  very  small,  and  but  imperfectly 
differentiated  in  their  histological  details. 

As  in  the  allied  forms,  the  epidermis,  the  nervous  system,  and  the 
sensory  organs  stand  in  closer  relations  to  one  another  than  they  do 
in  the  more  diflerentiated  forms ;  the  epidermis  is  largely  composed 
of  cubical  cells,  and  a  definite  cuticle  can  hardly  be  made  out ;  between 
these  cells  there  are  club-like  mucous  cells,  opening  to  the  exterior  by 
a  fine  orifice  ;  the  cilia  form,  for  the  greater  part,  circlets,  and  of  these 
we  find  a  double  one  in  front  of  and  a  single  one  behind  the  mouth ; 
while  on  the  post-oral  cephalic  region  there  are  foiu'  circlets.  On  the 
trunk-segments  there  is  anteriorly  and  posteriorly  another  circlet,  but 
the  cilia  are  delicate  and  sparsely  distributed.  The  sensory  hairs  are 
especially  numerous  on  the  tentacles,  the  anterior  end,  and  on  the 
posterior  segments,  and  there  is  also  a  better  developed  one  on  the 
two  terminal  processes. 

The  nervous  system  is  difficult  to  make  out  in  the  living  object, 
the  ganglionic  nature  of  the  frontal  ganglion  being  indistinguishable, 
and  the  presence  of  the  organ  merely  indicated  as  a  thickening  of 
the  integument ;  the  sensory  organs  are  represented  by  two  transverse, 
elongated,  ciliated  slits,  placed  on  the  dorsal  surface  of  the  anterior  por- 
tion of  the  head.  There  arc  no  pigmented  eyes.  Transverse  sections 
of  specimens,  suitably  hardened  and  prepared,  reveal  a  number  of  other 
facts.  The  apparently  sensory  bodies  connected  with  the  frontal 
plate  are  seen  to  consist -of  a  number  of  cells  ranged  round  a  central 
point ;  the  inner  part  of  the  frontal  ganglion  is  formed  of  a  largish 
mass  of  nerve-fibre;  the  neiglibouriug  epithelium  is  considerably 
thickened,  but  the  cells  are  really  all  arranged  in  a  single  layer.  Just 
in  front  of  the  mouth  the  fibruus  cord  bifurcates  to  become  connected 
with  the  lateral  i)arts  of  the  ventral  surface;  in  the  post-oral  cephalic 
region  they  approximate  towards  one  another.     lu  the  first  trunk- 


792  RECORD   OP   CURRENT   RESEARCHES  RELATING   TO 

segment  they  approacli  the  middle  line,  and  the  broad  ciliated  surface 
of  the  cephalic  region  is  converted  into  a  narrow  but  deep  ciliated 
groove.  It  was  not  found  possible  to  detect  any  peripheral  nerves. 
The  muscular  system  is  arranged  very  much  as  in  Polygordius. 

The  enteric  canal  extends  to  the  hinder  end  of  the  body,  but  no 
rectal  division  could  be  made  out  in  it.  Just  behind  the  mouth 
there  opens  into  the  oesophagus  a  muscular  organ  of  a  complicated 
form,  and  terminating  blindly  in  a  chitinous  vesicle  very  similar  to 
the  same  organ  in  Polygordius ;  it  has  a  function  which  still  remains 
to  be  discovered. 

In  the  first  trunk-segment  there  is  a  broad  dorsal  vessel,  which  in 
the  posterior  region  of  the  head  is  enlarged  into  a  contractile  bulb ; 
this  consists  of  a  simple  membrane  formed  of  flat,  doubly-granular 
cells.  By  rhythmical  contractions  the  bulb  drives  the  colourless 
blood  into  a  narrow,  thin-wallcd  vessel,  which  reaches  as  far  as  the 
frontal  ganglion,  and  there  opens  into  a  transverse  branch,  which  is 
continued  on  either  side  into  a  tentacular  vessel.  From  the  cavity 
into  which  these  open,  the  blood  is  carried  away  by  another  thin- 
walled  vessel.  A  transverse  venous  plexus  is  formed  behind  the 
frontal  ganglion,  and  from  thence  two  ventral  veins  pass  into  an  un- 
paired one.  The  bulb  already  mentioned  and  the  arteries  of  the 
tentacles  are  the  only  parts  that  are  contractile.  The  dorsal  vessel 
appears  to  be  filled  from  lacunae  in  the  enteric  walls,  and  its  lumen 
appears  to  be  a  continuation  of  the  cavity  within  the  entero-fibrous 
layer. 

The  segmental  organs  are  found  in  all  the  fully  developed  seg- 
ments, placed  in  the  lateral  line,  without  the  peritoneum.  They  com- 
mence by  a  narrow  infundibulum,  armed  with  a  long  flagellum ;  the  wall 
of  the  succeeding  portion  is  filled  with  granules  and  provided  with 
delicate  cilia ;  the  external  orifice  is  in  the  lateral  line,  and  pierces 
the  ectoderm. 

Protodrilus,  like  some  species  of  Polygordius,  is  hermaphrodite  ; 
the  ovaries,  which  consist  of  very  small  cells,  are  found  in  the  seven 
most  anterior  trunk-segments ;  behind  these  the  testes  are  developed. 
In  some  species  of  Polygordius  the  ovaries  as  well  as  the  testes  are 
developed  in  the  more  posterior  segments  ;  this  would  seem  to  indi- 
cate that  primitively  all  the  segments  were  hermaphrodite. 

The  author  concludes  by  remarking  on  the  extreme  simplicity 
which  may  be  exhibited  within  the  limits  of  the  Annelid  type. 

Enchytrseus  cavicola.* — This  is  a  new  species  of  a  blind  worm, 
described  by  Dr.  G.  Joseph,  and  discovered  in  a  grotto.  The  greyish- 
white  body  has  a  transjiarent  integument ;  the  ccelom  is  always  in 
communication  with  the  exterior  by  means  of  a  porus  cepliaUcus,  which 
is  placed  between  the  cephalic  and  oral  lobes ;  the  dorsal  vessel  has  a 
definite  wall  only  in  the  anterior  third  of  the  body ;  the  blood  was 
reddish  in  colour.  The  oesophageal  ganglionic  swelling  is  reniform  in 
shape,  and  gives  an  indication  of  a  commissure  by  a  shallow  grove. 
The  orifices  of  the  oviducts  are  transverse  clefts,  placed  between  the 

*  '  Zool.  Aijzeig.,'  ill.  (IS80)  p.  358. 


INVERTEBEATA,   CRYPTOGAMIA,    mCROSCOPY,   ETC.  793 

12-14tla  rings ;  tlie  testes  are  stalked,  and  the  seminal  glands  have  an 
"  amorphous  form  "  ;  by  these  two  points  the  new  species  is  distin- 
guished from  Pachydrilus,  while,  by  the  presence  of  red  blood,  it  is 
remarkable  among  other  species  of  Enchytrceus. 

Batrachobdella  Latasti,* — M.  Viguier  has  now  published  in  full 
his  account  of  the  organization  of  this  form  (see  this  Journal,  ii,  p. 
885).  The  author  is  of  opinion  that  in  it,  and  doubtless  also  in 
Clepsine  and  its  allies,  the  tactile  and  gustatory  sense-organs  are  to  be 
found  in  the  proboscis,  which  has  a  very  rich  plexus  of  nerves.  There 
are  only  two  eyes,  and  these  are  i)laced  close  to  one  another ;  they  are 
irregularly  quadrangular  in  form. 

The  author  has  some  doubt  whether  the  single  si^ecimen  of  Glossi- 
pJionia  alfjira,  which  Moquin-Tandon  was  able  to  examine,  and  on 
which  he  founded  the  species,  was  not  really  a  large  Batracliohdella. 
Bearing  in  mind  that  the  specimens  he  himself  was  enabled  to  examine 
were  not  fully  mature,  and  that  the  two  sj^ecies  have  the  same  habits 
and  inhabit  both  the  same  region,  he  concludes  by  throwing  out  the 
suggestion  that  M.  Taudon's  form  was  really  a  Batrachohdella,  and 
that  the  new  specific  name  of  Latasti  may  have  to  yield  to  the  prior 
appellation  of  algira. 

The  Chsetognatha.'f  — Oscar  Hertwig  publishes  a  monograph  of 
rather  more  than  one  hundred  pages  (and  five  plates)  on  these  very 
instructive  "  worms." 

The  author  commences  by  directing  attention  to  the  deep  signifi- 
cance which  must  be  given  to  the  two  modes  by  which  various 
animals  develop  their  coelom  or  body-cavity ;  in  the  greater^number 
of  animals  this  coelom  is  formed  by  a  cleavage  of  the  mesoblast, 
and  to  this  Professor  Huxley  has  applied  the  name  of  schizoccele ; 
others,  such  as  the  Echinodermata,  Brachiopoda,  and  Amphioxus, 
together  with  the  Chfetognatha,  develop  theii-  ccjelom  from  outgrowths 
of  the  endoblast,  and  to  this  form  Huxley  has  given  the  name  of 
enterocoele. 

It  is  now  ten  years  since  Kowalevsky  placed  these  differences  on 
the  firm  ground  of  observation,  but,  important  as  these  diiferences 
are,  they  have  hitherto  been  hardly  regarded  with  sufficient  atten- 
tion ;  to  what  results  they  may  lead  us  will  be  best  illustrated  by 
stating  at  once  the  general  conclusions  to  wliich  Dr.  0.  Hertwig  has 
been  led. 

Relations  of  the  Chcetof/natha  to  the  Codenterata. — The  Actinia)  by 

(1)  the  development  of  diverticula  from  the  primitive  cntcron,  and 

(2)  the  physiological  and  histological  characters  of  these  parts, 
exhibit  many  striking  relations  to  the  Chfctognatha.  It  is  at  a  very 
early  stage  in  devcloi)mcnt  that  the  arclienterou  of  Smjitta  bec<jmes 
divided  into  three  cavities,  or,  in  other  words,  jn-ovidcd  with  two 
lateral  diverticula  ;  a  septum  of  an  Actinian  and  an  endoblastic  fold 
of  a  Sagitta  arc  comparable  structures,  inasmuch  as  both  have  for 

*  ♦  Arch.  Zool.  cxp.  ct  Rcn.,'  viii.  (1880)  p.  .373. 
t  'Jen.  Zcibchr.,'  xiv.  (1880)  p.  11)0. 


794  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

their  primary  purpose  an  increase  of  the  internal  surface  of  the 
enteron.  The  differences  lie  in  the  degree  to  which  the  folds  or 
septa  are  developed.  In  the  Actinias  there  are  a  number  of  them, 
and  they  are  arranged  radially  around  the  enteric  axis ;  in  the 
Chsetognatha  there  are  only  two,  and  these  two  are  arranged  in  a 
bilaterally  symmetrical  fashion,  while,  instead  of  continuing  to  pro- 
ject into  the  enteron  by  their  free  edges,  they  become  shut  off  from 
it  and  converted  into  two  closed  sacs. 

Passing  to  the  question  of  their  functions,  we  find  both  in  the 
Actiniae  and  in  the  Chaatognatha  that  the  generative  organs  and  the 
musculature  of  the  body  are  developed  from  the  endoblast ;  the 
development  of  the  nervous  system  has,  moreover,  probably,  though 
not  certainly,  exactly  the  same  history  in  both  these  groups. 

Striking  as  these  resemblances  are,  they  are  not  sufficient  to  justify 
us  in  affirming  any  closer  relation  of  these  two  divisions  than  is 
as  yet  allowed  ;  all  that  we  see  is  that  there  is  in  the  develoj)ment  of 
organisms  certain  fundamental  laws  which  are  obeyed  by  different 
animals  ;  and  the  work  on  which  Hertwig  is  here  engaged  is  the 
study  of  the  laws  of  the  formation  of  organs  and  of  tissues. 

The  ChcBtognatJia  and  the  other  Worins. — The  Chaetognatha  seem, 
as  other  naturalists  have  already  noted,  to  be  most  nearly  allied  to 
the  Nematoids  and  Annelids  ;  with  the  former  the  most  important 
resemblances  lie  in  the  fact  that  in  many  of  them  (Gordiacea)  the 
enteric  canal  is  attached  to  the  dermo-muscular  tube  by  a  dorsal  and 
ventral  mesentery :  together  with  other  points,  we  have  to  note  that 
in  other  Nematoids  the  muscles  form  plates  which  are  set  perpen- 
dicularly to  the  surface  of  the  body,  and  are  made  up  of  parallel 
fibrils.  The  relations  of  Sagitta  to  the  Annelids  is  still  more 
remarkable  ;  if  we  make  a  transverse  section  through  a  Sagitta  and 
compare  it  with  a  somewhat  old  larval  stage  of  Polygordius,  we  find 
that  in  both  cases  the  enteron  is  invested  in  a  fibrous  enteric  layer, 
and  is  attached  by  mesenteries,  which  completely  divide  the  coelom 
into  a  right  and  left  half.  In  both  cases  there  are  four  bands  of 
longitudinal  muscular  fibres,  the  cells  of  which  are  derived  from  the 
ccelomatic  surface.  Points  of  resemblance  to  Spadella  cephaloptera 
are  to  be  observed  in  the  development  of  transverse  muscular  fibres 
on  the  inner  side  of  the  ventral  muscular  bands  and  in  the  minute 
structure  of  the  fibres.  The  two  transverse  septa  of  the  Chaetognatha 
are  comparable  to  the  numerous  transverse  septa  in  Annelids,  while, 
lastly,  in  both  groups  the  generative  products  are  derived  from  cells 
of  the  parietal  layer  of  the  mesoderm. 

Are  these  resemblances  analogical  or  homological  ?  To  answer 
this  question  we  must  first  answer  these  others.  Has  the  mesoblast 
been  formed  by  the  development  of  folds  or  by  the  differentiation  of 
cells  ?  Is  the  coelom  an  enterocoele  or  a  schizocoele  ?  These  are  the 
questions  which  the  author  is  anxious  to  bring  to  the  fore,  and,  until 
they  are  answered,  we  cannot  speak  confidently  as  to  either  the 
systematic  position  of  the  Cbfetognatha,  or  as  to  that  of  other  phyla 
and  divisions. 

We  must  deal  briefly  with  the  details  of  the  anatomy  and  histology 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  705 

of  the  Cliastoguatha,  on  which  Dr.  Hertwig's  general  conclusions  are 
based. 

The  more  or  less  cylindrically  shaped  body  of  the  Chfetognatha 
is  distinguished  from  that  of  all  other  Vermes  by  the  possession  of 
lateral  fin-like  appendages,  and  by  the  special  armature  of  its  head. 
The  lateral  fins  vary  in  number  and  character  in  diiferent  species,  but 
the  unpaired  caudal  fin  is  always  constant ;  this  latter  has  a  general 
resemblance  to  that  of  fishes,  but  diifers  from  it  in  being  horizontal 
and  not  vertical.  The  special  armature  which  gives  the  name  to  the 
group  may  be  regarded  as  consisting  of  (1)  spines  or  (2)  prehensile 
hooks  ;  the  former  are  small,  straight,  and  conical,  and  are  arranged 
in  2-4  rows  around  the  mouth.  The  latter,  of  which  there  are  only 
from  8-10,  are  very  much  longer,  sickle-shaped,  and  with  a  sharp 
point.  Connected  with  these  organs  is  the  special  and  characteristic 
apparatus  to  which  Krohn  gave  the  name  of  cephalic  cap.  This  con- 
sists of  two  thin  folds  of  integument,  which  arise  on.  the  dorsal  side  of 
the  head,  and  thence  pass  on  to  the  ventral  surface.  The  ca3lom 
varies  in  capacity  according  to  the  size  of  the  species,  but  is  always 
divided  by  two  thin  transverse  folds  into  three  parts  or  segments, 
which  may  be  respectively  denominated  the  head,  trunk,  and  tail 
segments. 

The  enteric  canal  takes  a  straight  course  through  the  body ;  the 
mouth  is  a  longitudinal  cleft  about  half  as  long  as  the  head  ;  in  the  tail 
segment  the  enteron  is  represented  by  a  caudal  septum  which  divides 
the  cavity  into  a  right  and  left  portion.  There  are  no  kidneys,  heart, 
or  blood-vessels  ;  each  individual  is  provided  with  two  ovaries  and 
two  testes ;  the  former  occupy  nearly  the  whole  of  the  trunk-segment, 
while  the  latter  are  developed  in  the  walls  of  the  cavity  of  the  caudal 
region  ;  one  segment  is,  therefore,  male,  and  another  female. 

Of  the  external  structures  we  can  only  notice  the  fins  and  the 
glandular  cells.  The  fins  are  reported  to  be  made  up  of  a  gelatinous 
supporting  substance,  of  homogeneous  filaments,  and  of  an  epidermal 
investment.  The  first  of  these  is  completely  structureless  and  devoid 
of  cells  ;  its  flat  surface  is  covered  by  the  homogeneous  filaments, 
which  are  closely  applied  to  one  another  and  end  in  a  fine  point ; 
in  transverse  section  they  are  semicircular,  and  may  be  seen  to  bo 
made  uj)  of  a  fii*m  structureless  substance,  in  which  no  distinct  cells 
can  be  made  out  in  the  adult.  The  cindermis  is  formed  by  a  single 
layer  of  thin  flattened  cells. 

The  glandular  cells  were  only  observed  in  one  species,  Spadella 
cephaloplcra.  Lamellar  in  form,  and  from  three  to  five  in  number, 
they  are  arranged  in  rosette  shape  around  a  central  point,  so  that 
they  seem  to  be  organs  of  attachment.  They  give  a  "  warty  "  appear- 
ance to  the  ventral  surface,  on  which  alone  they  are  developed ;  thuy 
are  most  common  near  the  tail,  and  become  rarer  and  smaller  ns  we 
approach  the  head.  The  constituent  cells  are  cither  cubical  or 
cylindrical  in  form. 

The  sensor  1/  organs  are  cither  tactile,  optic,  or  olfactory,  but  in  all 
cases  tlioy  retain  their  relations  to  the  ectoderm.  The  first  of  thcso 
form  small  elevations,  provided  with  still  tactile  setno  ;  they  may  be 


796  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

arranged  indefinitely,  or,  as  in  a  small  Sagitta  observed  by  Langerhans, 
tbey  may  be  arranged  by  sixes  in  forty  rings.  The  eyes  are  found  on 
tbe  upper  surface  of  the  head,  and  form  two  blackish  spots  of  so 
small  a  size  as  to  be  indistinguishable  to  the  naked  eye.  When  mag- 
nified, the  eyes  are  seen  to  be  formed  by  sj^heres,  made  uji  of  small 
cells,  which  are  enclosed  by  the  usual  transparent  epidermis,  and  are 
sharply  separated  off  from  that  layer ;  the  part  exposed  to  the  light 
is  coloured  by  a  blackish  pigment  and  contains  a  transparent  lens ; 
these  last  two  structures  are  surrounded  by  a  circlet  of  numerous, 
highly  refractive  rods  ;  the  form  of  these  rods  is  highly  characteristic. 
The  end  which  is  approximated  to  the  pigment  and  lens  is  thin  and 
cut  short  along  a  transverse  axis  ;  the  rods  then  thicken  somewhat, 
but  suddenly  diminish  in  width  towards  their  tip.  Still  further  and 
closer  examination  leads  to  the  conclusion  that  the  eye  of  the  Chfeto- 
gnatha  is  not  a  simple  but  a  complex  structure,  aifording  many  points 
of  resemblance  to  the  same  organ  in  the  Crustacea ;  there  are  three 
lenses,  and  it  is  clear  that  the  eye  is  made  up  by  the  fusion  of  three 
simple  ocelli.  The  "  optic  epithelium  "  consists  of  a  rod  and  a  layer 
of  granules,  which  are  sharply  distinguished  from  one  another.  The 
organ  is  comj)letely  enclosed  in  the  epidermis,  and  is  invested  on  its 
outer  face  by  a  thin  layer  of  flattened  ejiidermic  cells. 

The  olfactory  organ  does  not  seem  to  have  been  hitherto  correctly 
apprehended ;  it  is  placed  near  the  eye,  on  the  upper  surface  of  the 
head,  and  behind  the  supra-oesophageal  ganglion ;  it  is  unpaired,  and  is 
of  a  simple  character.  There  is  a  delicate  epithelial  band,  made  up 
of  fine  cylindrical  cells  lying  on  the  trausjiarent  cells  of  the  epidermis, 
and  forming  a  slight  projection.  In  the  middle  of  the  band  there  are 
two  or  three  rows  of  cells  which  are  provided  with  very  long  delicate 
cilia.  The  epithelial  bands  vary  in  form  in  various  species  ;  they 
are  supplied  by  two  well-developed  nerves,  which  arise  from  the 
posterior  surface  of  the  supra  oesophageal  ganglion,  and  pass  to  the 
olfactory  organ  along  a  line  parallel  to  that  of  the  optic  nerves. 

The  nervous  system  of  these  creatures  is  of  especial  interest,  inas- 
much as  the  chief  ganglia  and  the  nerves  from  them  are  imbedded  in 
the  epidermis,  while  some  of  the  smaller  cejDhalic  ganglia,  with  their 
nerves,  belong  to  the  mesoderm  ;  we  have,  therefore,  in  the  nervous 
system  of  the  Chsetognatha  to  distinguish  an  ectodermal  and  a  meso- 
dermal portion.  The  former  consists  of  two  central  organs,  the 
supra-oesophageal  and  the  ventral  ganglia,  together  with  their  nerves  ; 
the  mesodermal  portion  is  imbedded  in  the  head.  The  supra- 
cesophageal  or  cephalic  ganglion  is  imbedded  in  the  epidermis,  and 
forms  a  slight  outwardly-projecting  protuberance;  in  form  it  is 
regularly  hexagonal,  and  it  is  separated  on  its  lower  surface  by  a 
supporting  lamella  from  the  subjacent  musculature.  It  is  made  up 
of  a  mass  of  delicate  fibres  and  of  small  ganglion-cells;  from 
the  former  there  are  given  off  four  stronger  and  six  more  delicate 
nerves ;  two  of  the  former  are  the  anterior  motor  nerves,  and  the 
other  two  are  the  commissures  by  which  these  are  connected  with 
the  ventral  ganglionic  mass.  The  six  more  delicate  nerves  are  all 
sensory.     The  ventral  is  larger  in  size  than  the  cephalic  ganglion, 


INVEETEBBATA,    CRYPTOGAMIA,   MICEOSCOPY,   ETC.  797 

and  is  placed  at  about  the  centre  of  the  trunk-segment ;  owing  to  its 
projection  outwards,  it  has  by  some  authors  been  spoken  of  as  the 
"  ventral  saddle."  Here  again  there  is  a  fibrous  medullary  and  a 
cortical  cellular  subtsance.  In  addition  to  the  commissures  already 
noticed,  there  are  given  off  from  it  ten  to  twelve  delicate  nerves  on 
either  side,  and  two  well-developed  trunks  from  its  posterior  aspect. 
These  various  trunks  are  not  distinctly  separated  from  one  another, 
but  unite  largely  so  as  to  form  a  considerable  nerve  plexus. 

There  appear  to  be  considerable  difficulties  in  the  way  of  the 
examination  of  the  mesodermal  portion  of  the  nervous  system.  Ee- 
turning  to  the  two  motor  nerves,  which  are  given  off  from  the  supra- 
cesophageal  ganglion,  we  find  tliat  they,  after  passing  some  way 
forwards,  make  a  dip  into  the  mesoderm ;  here  they  are  enlarged  into 
a  ganglion,  which  may  be  known  as  the  lateral  cephalic  ganglion. 
This  body  is  semilunar  in  shape,  and  consists  largely  of  dotted 
substance  and  slightly  of  superficial  cells.  Several  uerves  are  given 
off  from  it,  which  pass  to  the  muscles  of  the  head.  There  are  also  on 
either  side  two  very  small  mesodermal  ganglia,  which  are  like  those 
developed  on  the  cephalic  nerves.  One  of  these  is  called  the  buccal 
ganglion.  Certain  difficulties  still  remain  to  be  overcome  as  to  the 
innervation  of  the  musculature  of  the  trunk ;  it  seems  that  either  the 
numerous  well-develoiied  nerves  which  are  given  off  from  the  meso- 
dermal cephalic  ganglia  supply  these  parts,  or  that  the  superficial 
tegumentary  plexus  already  noticed  sends  fibrils  to  the  muscles.  The 
author  inclines  to  the  former  view,  and  points  out  that,  if  it  be  correct, 
the  function  of  the  ectodermal  nerve-plexus  would  be  to  convey 
stimuli  to  the  ventral  ganglion,  whence,  by  the  commissm-es,  they 
would  be  carried  to  the  supra-oesophageal  ganglion,  and  thence  con- 
veyed by  the  two  motor  nerves  to  the  musculature.  If  this  view  shall 
be  shown  to  be  right,  it  will  clearly  follow  that,  in  the  Chaitognatha, 
the  sensory  and  motor  nervous  systems  are  distinct  fx'om  one  another, 
and  that  the  former  would  be  ectodermal,  while  the  latter  would  be, 
with  the  musculature,  mesodermal  in  origin. 

There  are  some  important  points  in  the  characters  of  the  mus- 
cular system.  As  is  well  knowu,  the  muscles  of  these  creatures  arc 
transversely  striated ;  it  is  now  further  pointed  out  that  the  muscular 
lamclla3  are  set  in  such  a  way  that  the  delicate  intersjiaces  between 
them  only  open  towards  the  coelom.  Of  the  questions  which  we 
ask  ourselves  when  wo  examine  into  the  characters  of  this  system 
one  of  the  most  important  is  that  which  has  refcrcucc  to  the  relations 
of  the  muscular  elements  of  the  Cha;tognatha  to  those  of  other  animals. 
It  seems  impossible  to  institute  any  comparison  between  tlicm  and 
either  the  Vcrtebrata  oi-  the  Arthropoda,  for  the  muscular  fibrils 
are  not  arranged  in  bundles,  but  in  lamella) ;  there  is,  however,  a 
very  considerable  x-cseniblance  to  what  obtains  in  the  Ccolenterata, 
and  the  study  of  this  resemblance  seems  to  lead  to  the  conclusion  that 
in  tlie  Cha;tognatha  the  muscle-fibrils  were,  primitively,  spread  out  in 
a  tliin  lamella,  and  that,  by  tlie  growtli  of  tliis,  fddiugs  were  formed 
which  led  to  the  leaf-like  arrangement  which  obtains,  in  some  parts, 
later  on  ;  further  considerations  lead  to  the  important  conclusion  that 


798      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

myoblasts  arc  to  be  looked  for  in  tlie  epithelium  of  the  coelom  (body  - 
cavity). 

Poor  as  is  the  "  cephalic  cap "  in  muscles,  it  has  a  structure  of 
considerable  interest,  for  it  contains  the  nerve-trunks  which  connect 
the  ventral  with  the  cephalic  ganglion,  as  well  as  the  eyes  and  the 
optic  nerves.  In  Spadella  cephaloptera  there  was  also  to  be  observed 
on  either  side  a  short  tentacular  process,  which  terminates  in  a  knob- 
like enlargement. 

After  a  short  account  of  the  enteric  tract  and  the  mesenteries,  the 
author  passes  to  a  consideration  of  the  Generative  Organs.  In  animals 
which  are  sexually  mature  the  hinder  portion  of  the  two  cavities  of 
the  trunk-segment  may  be  seen  to  be  almost  completely  filled  with  the 
two  ovaries  ;  these  are  more  or  less  cylindrical  bodies,  which  are  only 
attached  by  a  thin  and  short  mesentery ;  they  consist  of  a  rather  narrow 
oviduct,  and  of  a  true  ovary.  The  contents  of  the  former  vary  in 
individuals,  and  in  some  cases  the  author  was  able  to  detect  in  them 
spermatozoa  in  active  movement.  There  is  some  difficulty  in  under- 
standing how  the  matured  products  escape  to  the  exterior  ;  Hertwig  is 
of  opinion  that  it  is  the  hinder  portion  only  of  the  oviducts  which 
serves  for  the  extrusion  of  the  eggs,  while  the  large  caecal  portion 
functions  as  a  kind  of  receptaculum  seminis. 

The  male  organs  form,  so  far  as  the  matrix  of  the  spermatozoa  is 
concerned,  a  projection  into  the  most  anterior  portion  of  the  caudal 
segment ;  from  this  there  are  set  free  masses  of  unripe  spermatozoa, 
which  may  be  seen  to  be  executing  a  regularly  circulatory  movement. 
The  efferent  ducts  lie  in  the  hinder  portion  of  the  caudal  segment, 
and  the  short  canal  has  at  its  anterior  end  an  infundibular  ciliated 
orifice.  The  spermatozoa  are  collected  into  a  seminal  vesicle,  more 
or  less  elongated  and  oval,  but  varying  in  form  in  the  various  species. 

The  following  table  exhibits  the  system  of  the  group  : — 

Ch^tognatha. — Body  consisting  of  three  segments,  separated  by 
septa,  and  provided  with  horizontal  fins.  The  head  with  prehensile 
hooks,  spines,  and  a  "  cap,"  with  two  eyes,  and  an  unpaired  olfactory 
organ  ;  coelom  spacious.  The  enteron  has  two  mesenteries,  and  ojieus 
in  front  of  the  anenterous  caudal  segment.  Four  longitudinal  muscular 
bands.  Nervous  system  consists  of  the  ventral,  the  supra-oesophageal, 
and  the  lateral  cephalic  ganglia.  Trunk-segment  with  two  ovaries  ; 
caudal  segment  with  two  testes. 

I.  Sagitta. 

Unpaired  caudal,  two  pairs  of  lateral  fins. 
(a)  Species  from  3-7  cm.  long. 

1.  S.  hexaptera;  2.  ;S.  lyra ;  3.  S.  magna;  4.  S.  tricuspidata ; 
5.  S.  bipunctata ;  6.  S.  serratodentata;  7.  S.  mariana  ;  8.  S.  pontica  ; 
9.  S.  diptera ;  10.  S.  iriptera. 

II.  Spadella. 
Unpaired  caudal  fin ;  one  pair  lateral  fins. 
1.  S.  cepTialoptera ;  2.  S.  draco ;  3.  S.  hamata. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  799 

The  fourth  chapter  of  this  very  valuable  essay  deals  with  the 
development  of  the  Chastognatha,  for  the  study  of  which  S.  hipunctata 
and  S.  serratodentata  are  reported  to  be  very  suitable  objects.  Here 
we  can  only  very  briefly  note  one  or  two  points.  (I)  There  is  formed 
a  typical  gastrula.  (2)  Before  this  stage  is  lost,  part  of  the  endoblast 
gives  rise  to  the  fii-st  elements  of  the  generative  organs,  and  another 
part  to  the  rudiments  of  the  enteric  canal  and  of  the  body-cavity. 
(3)  The  two  large  cells  in  the  endoblast  of  the  gastrula  give  rise  to 
the  male  and  female  generative  organs.  For  the  further  consideration 
of  these  and  other  points  our  space  compels  us  to  refer  to  the  figures 
and  descriptions  given  in  the  original. 

Disease  produced  by  Anchylostoma  duodenalis.* — The  develop- 
ment of  this  parasite  has  been  followed  by  Professor  Perroncito  up  to 
the  stage  at  which  it  enters  the  body  of  man,  and  is  of  especial  im- 
portance with  regard  to  the  epidemic  caused  by  it  among  the  work- 
men at  the  St.  Gothard  tunnel.  Three  parasites  occur  in  the 
intestine,  all  producing  the  same  symptoms,  and  causing  the  disease 
known  as  Oligcemia  perniciosa ;  they  are  Anchylostoma  (Dochnius) 
duodenalis,  Anguillula  intestinalis  and  stercoralis,  and  may  occur  in  the 
different  subjects  either  separately  or  mixed. 

Larval  development  of  Ancliylostoma  duodenalis  outside  the  human 
body. — The  eggs  are  oval,  thin  shelled,  transparent,  measuring  •  052 
by  •  032  mm.  At  twelve  to  fourteen  hoiu's  from  the  commencement  of 
incubation,  traces  of  larvae  are  visible  in  a  very  few ;  in  one  to  two  days 
most  show  larvas  in  various  stages,  and  after  some  days  they  issue.  In 
eggs  kept  at  between  28^  and  33°  C.  the  exit  is  seen  to  be  made  by  two 
or  three  blows  which  occur  within  a  minute  of  each  other  ;  the  head 
emerges  generally  a  little  to  the  side  of  one  of  the  poles ;  the  first 
effort  is  the  most  vigorous,  for  it  springs  out,  moving  the  body 
laterally  with  great  force ;  the  movements  continue  for  a  short  time, 
and  then  a  period  of  quiescence  and  expansion  ensues  ;  the  length  at 
birth  is  ■  2  mm.  and  maximum  diameter  •  Oli  mm. ;  the  body  is 
slightly  attenuated  in  front  of  the  pharynx,  and  ends  posteriorly  in 
an  awl-like  thin  tail ;  the  head  is  trilobate,  and  a  rectangular  tube 
•014  mm.  long  represents  the  mouth;  the  pharynx  has  an  anterior 
dilatation,  and  a  little  behind  tliis,  another,  the  pharyngeal  bulb, 
carrying  chitinous  teeth;  the  whole  tube  is  strongly  muscular  and 
leads  into  an  intestine  with  a  zigzag  cavity,  ending  at  a  slightly 
prominent  anus.  The  rudiment  of  the  genital  apparatus  is  seen  as  an 
oval  mass  near  the  middle  of  the  body,  on  the  anal  side,  between  the 
intestine  and  the  dermal  muscular  layer.  After  the  first  day  the 
larva  is  •  25  mm.  long,  and  continues  to  increase  at  the  rate  of  •  05  mm. 
per  diem,  as  long  as  the.  temperature  docs  not  exceed  21*^  to  25^  C. ; 
the  maximum  length  is  "55  mm.,  the  breadth  -02- -02-1  mm.  After 
eight  hours  of  life,  the  intestine  assumes  a  straight  position.  After 
some  days,  serpentine  movements  occur  at  temperatures  even  of  l-i^ 
to  10''  C.  After  the  maximum  size  is  attained,  the  pharynx  under- 
goes modifications,  and  is  finally  altogether  renewed.      Moauwhilo, 

•  '  Atli  Acciul.  Lincei  (TmiiBUuti),*  iv.  (1880)  p.  179. 


800  RECOKD   OF   CURRENT   RESEARCHES  RELATING   TO 

the  skin  excretes  a  transparent  chitinous  substance,  forming  a  capsule 
which  encloses  the  whole  animal,  allowing  of  its  free  movement 
within.  Now  the  mouth  develops  the  rudiments  of  its  hooks  and 
styles ;  the  intestine  becomes  less  granular  and  more  transparent ; 
between  two  of  the  middle  segments  appear  the  papillae  which  occur 
on  the  sides  of  the  perfect  worm.  The  space  left  in  the  capsule  round 
the  worm  gradually  diminishes,  and,  chiefly  at  the  end,  calcareous 
corpuscles  are  excreted,  of  round,  rectangular,  &c.,  shape,  forming  a 
protective  crust.  The  acid  of  the  gastric  juice  dissolves  the  coat  and 
leaves  the  larva  free  ;  but  death  occurs  if  it  does  not  reach  a  human 
body ;  in  the  encapsuled  state  it  resists  desiccation  and  the  action  of 
indifferent  fluids  for  twenty-fom*  hours,  and  lives  well  in  clear  or 
muddy  water ;  a  single  drop  of  water  may  contain  100  larvae. 

Larval  Development  of  Anguillula  intestinalis.  —  The  eggs  are 
oval,  with  more  pointed  poles  than  in  Ancliylostoma ;  they  measure 
•  05-*  06  mm.  by  •  03-"  036  mm.  Development  progresses  well  at  the 
temperature  25°  to  26''  C. ;  bii*th  takes  place  in  from  fourteen  to 
twenty  hours  ;  the  embryos  are  more  clearly  visible,  and  move  more 
vigorously  within  the  shell,  than  in  Anclujlostoma.  A  short  quiescent 
stage  ensues  on  birth,  followed  by  active  movements ;  the  length  of 
the  larva  is  -2- -24  mm.,  the  diameter  -012  mm.;  it  is  slightly 
attenuated  in  front  and  has  a  very  sharp  tail.  The  head  is  trilobate, 
the  mouth  rectangular,  with  a  pharynx  and  pharyngeal  bulb  ;  the 
intestine  is  cellular  and  zigzag ;  a  genital  rudiment  exists  in  the  same 
position  as  in  Anchylostoma.  The  larvae  need  a  liquid  medium  more, 
and  die  if  the  mass  becomes  somewhat  dry,  showing  a  fatty  breaking- 
down  of  the  tissues,  but  live  in  distilled  or  common  water  and  in  5  to  7 
per  cent,  solutions  of  common  salt  or  sulphate  of  soda.  In  a  liquid  or 
semi-liquid  medium  the  larva  doubles  its  length  in  twenty-four  hours, 
becoming  -016  mm.  thick;  the  head  is  round,  the  body  cavity  is 
surroimded  by  the  dermo-muscular  layer,  which  secretes  a  most 
delicate  chitinous  capsule  for  the  body. 

Anguillula  stercoralis  Bavay,  development  of  larva  outside  human 
body. — The  larvae  are  developed  in  the  maternal  uterus  and  are  ex- 
pelled with  the  faeces  at  diiferent  stages;  they  are  then  free  and 
active,  measuring  •2-- 26  mm.  by  •  014-- 016  mm.;  the  anterior  end 
of  the  body  is  larger,  the  mouth  shorter,  the  pharynx  shorter  and 
broader,  the  intestine  longer  and  wider  than  in  the  same  stage  of 
Anchylostoma.  The  genital  rudiment  is  very  characteristic,  being 
shuttle-shaped  and  •  025  mm.  by  •  003  mm.  in  size.  Encapsulation 
generally  takes  place  in  a  day.  Experiments  with  different  tem- 
peratures proved  that  the  larvae  always  exhibited  movements  within 
five  seconds  at  a  temperature  of  50°  C. 

Facts  show  that  these  worms  were  alone  sufficient  to  cause  the 
disease  of  aneemia  observed  at  the  St.  Gothard  tunnel ;  the  disease 
probably  resulted  from  the  unfavourable  conditions  under  which  so 
many  poor  workmen  were  engaged  together. 

Anguillula  intestinalis  should  be  removed  from  that  genus,  and  is 
better  named  Slrongylus  papillosus,  the  reasons  for  which  change  of 
name  are  reserved. 


INVERTEBRATA,    CRYPTOGAMIA;  MICROSCOPY,    ETC.  801 

Organization  and  Development  of  the  Gordii.*  —  M.  A.  Villot 
insists  upon  the  fact,  tliat  the  first  larval  form  of  the  Gordius  differs 
greatly  from  that  of  the  Nematoid  worms.  In  these  latter,  even 
including  tlie  aberrant  genera  (Mermis  and  SphcBruIaria)  the  embryo 
and  the  larva  are  represented  by  the  tyjies  of  the  Anguillulje  (RJiab- 
diiis).  Now  it  would  need  a  great  effort  of  imagination  to  refer  the 
larva  of  Gordius  to  this  type.  The  order  Gordiacei,  as  established 
by  Von  Siebold,  cannot,  therefore,  be  retained  by  zoologists,  who 
nowadays  attach  the  greatest  importance  to  the  characters  furnished 
by  embryogeny  and  morphogeny. 

The  second  larval  form  difiers  from  the  first  as  much  as  the  latter 
differs  from  the  sexual  form.  It  is  characterized  essentially  by  the 
loss  of  the  styles,  the  shedding  of  the  booklets,  and  the  disappearance 
of  the  annulations. 

Each  of  the  two  larval  periods  includes  two  very  distinct  phases, 
that  of  parasitism  and  that  of  aquatic  existence  ;  but  these  two  phases 
do  not  in  each  case  occur  in  the  same  order.  In  its  first  larval  form 
the  young  Gordius  passes  from  aquatic  life  to  the  state  of  a  parasite ; 
in  its  second  larval  form  it  quits  its  post  to  return  to  the  water.  The 
two  phases  of  parasitism,  although  immediately  succeeding  one 
another,  differ  essentially.  So  long  as  the  first  phase  lasts,  the  young 
\vorm,  enclosed  in  its  cyst,  remains  motionless,  and  does  not  appear 
to  take  any  nourishment  or  to  grow  at  all.  During  the  second,  on 
the  contrary,  it  is  free,  lives  at  the  exj)enso  of  its  host,  and  becomes 
very  rapidly  dcveloiied. 

It  lias  been  sujiposcd  hitherto  that  the  passage  from  the  first 
larval  form  to  the  second  is  connected  with  a  migration,  a  change  of 
host.  The  observers  who  saw  larvse  of  Gordius  encyst  tliemselvcs  in 
larvaj  of  Ei^hemeridfe  supposed  that  the  Dyticidfe  swallowed  these 
encysted  larvae  with  their  prey,  and  that  the  young  Gordii  developed 
themselves  in  the  visceral  cavity  of  their  new  host.  For  this 
hypothesis,  which  is  still  classical,  the  author  substituted  another 
which  appeared  of  more  general  ajiplication.  He  said  that  the 
Gordii  parasitic  upon  fishes  proceed  from  larva;  previously  encysted  in 
various  species  of  Tipulida?,  the  larvae  of  which  likewise  lived  in  the 
water;  and  he  founded  Ins  argument  upon  the  consideration  that 
fishes  arc  in  general  very  fond  of  those  insects.  Both  hypotheses 
arc  contradicted  by  the  well-ascertained  fact  that  the  two  larval  forms 
of  the  Gordii  live  indifferently  in  the  various  aquatic  hosts  indicated. 
He  therefore  now  regards  it  as  very  probable  that  the  two  phases  of 
the  parasitism  of  the  Gordii  are  accomplished  in  one  and  the  same  host. 

Observation  also  proves  that  the  larva)  of  the  Gordii  do  not  select 
their  host.  They  encyst  themselves  and  become  developed  in  the 
most  different  animals  (Batracliians,  fishes.  Crustaceans,  Arachnids, 
insects,  and  molluscs).  It  is  therefore  by  no  means  the  case,  whatever 
may  have  been  said,  that  the  larva)  of  the  Gordii  are  parasites  j^cctdiar 
to  insects.  As  regards  fishes,  these  are  perhaps  the  animals  which 
harbour  these  larvro  most  frequently  and  in  the  greatest  number. 

♦  'ComptcH  Rcndus,'  xci.  (1880)  p.  15G9.  See  'Ann.  and  Mng.  Nnt.  Hist.,' 
vi.  (lS80)p.  1G9. 

VOL.    III.  3   G 


802      KEOOKD  OF  CURRENT  RESEARCHES  RELATING  TO 

It  is  none  tlie  less  evident  that  the  normal  hosts  of  the  Gordii  are 
all  animals  exclusively  or  temporarily  aquatic.  Water  is,  in  fact,  the 
normal  medium  of  the  Gordii.  It  is  in  the  water  that  they  become 
adult,  and  that  they  reproduce ;  it  is  in  the  water  that  their  larvae 
live  at  first  on  their  escape  from  the  egg ;  and  it  is  also  in  the  water 
that  their  migration  must  be  effected. 

The  parasitism  of  the  larvae  of  the  Gordii  in  terrestrial  animals 
has  an  essentially  abnormal  and  exceptional  character ;  and  in  order 
to  explain  it  we  must  have  recourse  to  very  peculiar  conditions.  In 
plains  these  are  realized  by  the  periodical  inundations  and  systematic 
irrigations, — in  mountainous  and  hilly  countries  the  escaping  torrents 
carry  away  everything  in  their  course,  the  insects  perish,  and  the 
worms  which  they  contain  are  set  at  liberty. 

The  frequency  of  the  larvae  of  Gordii  in  insects,  which  is  cited  as 
an  objection  to  the  author's  views,  is  more  apparent  than  real.  It 
must  be  remembered  that  the  insects  are  represented  by  a  great 
number  of  species,  and  are  sought  after  by  most  naturalists. 

Excretory  System  of  the  Trematoda  and  Cestoda.* — M.  Frai- 
pont,  in  a  preliminary  notice  as  to  the  results  at  which  he  has  arrived, 
says  that 

(1)  The  excretory  apparatus  arise  from  small,  and  not  numerous, 
infundibula,  which  communicate  with  the  spaces  between  the  organs 
by  an  orifice  placed  in  their  lateral  wall.  The  greater  part  of  every 
infundibulum  is  formed  by  a  single  cell  armed  with  a  vibratile 
flagellum. 

(2)  In  the  intervening  spaces  he  finds  a  system  of  very  delicate 
canalicula,  which  are  arranged  in  a  radial  fashion. 

(3)  The  infundibula  are  arranged  almost  symmetrically  on  either 
side  of  the  middle  line,  and  each  gives  rise  to  a  small  canal,  several  of 
which  converge,  anastomose,  and  then  open  into  a  system  of  large 
vessels,  placed  at  six  definite  points  in  the  body,  and  symmetrically 
disposed  two  by  two.  There  may,  consequently,  be  said  to  be  three 
pairs  of  segmental  organs,  and  it  is  of  interest  to  remember  that  in 
the  larval  IJirudinea  there  are  three  pairs  of  segmental  organs  in  the 
posterior  region. 

(4)  The  system  of  large  canals  form  two  lateral  trunks,  which 
rapidly  bifurcate  ;  of  the  branches  thus  formed,  one  passes  towards  the 
middle  line  to  anastomose  with  its  fellow  of  the  opposite  side.  The 
other  passes  along  the  whole  of  the  lateral  edge  of  tlie  body,  and 
after  giving  oif  diverticula  which  increase  in  complexity  with  the 
age  of  the  individual,  terminate  blindly.  The  trunks  themselves 
open  into  a  terminal  reservoir,  which  is  filled  with  highly  refractive 
corpuscles,  and  opens  to  the  exterior  in  the  middle  line  and  at  the 
hinder  end  of  the  body. 

The  preceding  being  an  account  of  what  is  found  in  such  Trema- 
toda as  Polystomum  integerrimum,  Octohotlirium  lanceolatiim,  and  Diplo- 
zoon  paradoxum,  we  have  next  to  inquire  what  obtains  in  the  Cestoda. 
"  In  Caryopkyllceus  mutabilis  there  is  the  following  arrangement : — 

*  '  Bull.  Acad.  Roy.  Belgique,'  xlix.  (1880)  p.  397. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC  803 

(1)  There  are  small  ciliated  infundibula,  identical  with  those  just 
described, 

(2)  The  canaliculus  from  each  infuudibulum  has  a  more  or  less 
tortuous  direction.  They  are  arranged  in  groups,  and  anastomose 
with  one  another. 

(3)  They  give  rise  to  a  superficial  plexus,  whence  two  largo 
trunks  pass  from  behind  forwards,  on  either  side  ;  and  these  four 
are  connected  anteriorly  with  ten  largo  longitudinal  trunks. 

(4)  Those  last  anastomose  largely  in  the  head,  and  during  their 
course  communicate  with  one  another  by  transverse  branches ;  they 
open  by  ten  orifices  into  a  reservoir  at  the  hinder  end  of  the  body. 

The  ciliated  infundibula  have  also  been  detected  in  the  cysticerci 
of  Tcenia  serrata,  in  the  adult  T.  serrata,  and  in  T.  cucumerina, 

Tlie  author  refrains  for  the  present  from  entering  into  any  general 
speculations,  and  contents  himself  with  pointing  out  the  bearings 
which  the  facts  he  details  have  on  the  affinity  between  the  Platyhel- 
minthes,  on  the  one  hand,  and  the  Rhyncoccela  and  Hirudinea  on  the 
other.  These  worms  may,  he  thinks,  bo  divided  into  the  Coelomati 
and  the  Acoelomati  ;  for  the  latter  (the  Trematoda  and  Cestoda)  have 
the  coelom,  in  which  the  hajmolymph  circulates,  in  a  rudimentary 
condition. 

Development  of  the  Liver  Fluke.* — M.  Baillet  shows  that 
segmentation  may  begin,  and  even  be  completed,  while  tlic  egg  is 
unlaid,  or  the  process  may  take  place  in  the  bile-ducts  or  gall-bladder 
of  the  host.  Further,  the  withdrawal  of  the  eggs  from  the  body 
of  the  latter  does  not  kill  them,  as  is  the  case  with  the  Nematode, 
Sclerosiomum.  Media  seem,  in  fact,  to  be  of  little  importance  in  this 
matter,  for  presence  or  absence  of  light,  immersion  in  common  water, 
in  water  containing  organic  matter  in  solution,  in  damp  earth,  alike 
seem  to  influence  neither  the  quickness  nor  perfection  of  the  develop- 
ment. 

Anatomy  of  the  Nemertinea.f — Herr  Dewolctzky  has  come  to 
the  following  conclusions,  as  he  states  in  a  preliminary  account: — 

(1)  The  tegunieiitary  epithelium  contains  other  than  the  two 
forms  of  cells  already  recognized  ;  there  arc  fihimentous  supporting 
cells,  gland  cells,  both  miicou.s  and  granular,  as  well  as  the  terminal 
cells  of  nerves,  and  cells  which  secrete  pigments,  or  concretions  of 
definite  f(u-m. 

(2)  The  ccsophftgcal  epithelium  is  devoid  of  mucous  cells ;  tlio 
supporting  cells  are  shorter  and  more  massive  ;  while  the  granular 
cells  are  not  deeply  inlaid,  and  only  communicate  with  the  exterior 
by  fine  efferent  ducts. 

(3)  In  the  sensory  epithelium  tliere  appear  to  be  no  glands  at 
all ;  while 

(4)  In  tlie  epithelium  whieh  lines  the  canal  of  tlie  lateral  organ 
the  glands  are  confined  to  two  points. 

♦  •  Mc'in.  Acad.  Sci.  Inscrip.  ct  ncllcs-Lettrcs,'  Toulouse,  1879.  Sec  *  Riv. 
Bci.  Nat.,'  ii.  (18H0)  p.  114. 

t  '  Zool.  Anzeip.,'  ill.  (1880)  p.  ."iTi"). 

;i  o  2 


804  RECORD   OF   CURRENT   RESEARCHES  RELATING   TO 

After  reminding  the  reader  that  the  so-called  lateral  organ  has,  by 
the  latest  researches,  been  seen  to  be  composed  of  a  number  of 
ganglionic  cells  and  of  a  fibrous  cord,  together  with  a  ganglion  in- 
vested in  a  membrane  of  connective  tissue,  and  that  there  lies  in  it  a 
blindly  ending  ciliated  canal,  the  author  states  that,  as  to  this  last,  it 
forms  in  the  first  third  of  its  course  a  wide  cylindrical  vestibule,  which 
suddenly  narrows.  At  the  two  points  where  the  lumen  of  the  canal 
is  constricted,  there  are  to  be  found  the  orifices  of  a  number  of  long, 
fine  efferent  ducts,  which  pass  ofi"  from  the  unicelhilar  glands,  and  are 
massed  together  on  the  surface  of  the  ganglion.  The  cilia  which  line 
the  canal  work  towards  the  blind  end.  The  structure  of  the  narrower 
portion  of  the  canal  is  somewhat  remarkable ;  there  is  a  layer  of 
longish,  compressed,  rod-shaped  corpuscles,  set  almost  completely  at 
right  angles  to  the  lumen ;  these  rods  ajjpear  to  be  the  bases  of  the 
projecting  cilia.  The  special  investment  of  the  canal  would  appear 
to  be  a  specific  sensory  epithelium,  modified  from  the  ordinary  tegu- 
mentary  layer,  while  the  gland  cells  have  been  pushed  inwards 
(downwards)  by  the  ganglionic  masses  of  the  lateral  organ,  and  further, 
have  become  localized  to  two  distinct  points,  where,  clearly  enough, 
they  take  on  the  function  of  defending  the  sensory  epithelium. 

As  to  the  proper  sensory  organ,  the  function  of  which  is  not 
known,  the  author  suggests  that,  as  in  so  many  other  aquatic  and 
marine  forms,  we  have  to  do  with  a  rudimentary  organ  which  has 
some  function  in  relation  to  the  character  of  the  water.  He  is  re- 
minded by  what  he  has  seen  in  the  Nemertinea  of  the  organ  of 
Lacaze-Duthiers  in  the  fresh- water  Pulmonata,  and  he  is  supported 
in  his  view  by  the  fact  that  just  as  one  organ  is  absent  in  the  terres- 
trial Pulmonata,  so  is  the  other  in  the  terrestrial  Nemertinea. 

The  enteric  epithelium  consists  of  glandular  and  of  elongated 
absorptive  cells ;  the  latter  contain  a  number  of  highly  refractive 
spheres,  which  appear  to  be  of  an  albuminous  nature,  and  are  appa- 
rently drops  of  digesting  food.  Between  the  circular  muscular  layer 
and  the  epithelium  there  is,  in  all  the  Nemertinea,  a  more  or  less  well- 
developed  layer  of  connective  tissue,  which  is  distinguished  by  the 
author  as  the  subtegumentary  connective  tissue  ;  it  has  been  described 
as  a  "  basilar  membrane,"  but  it  is  provided  with  distinct  corpuscles, 
and  is  not  structureless.  In  all  Anopla  the  nervous  system  seems  to 
lie  between  this  tissue  and  the  circular  musculature  ;  in  the  more 
differentiated  Enopla  it  lies  beneath  the  circular  muscles. 

The  excretory  system  of  Tetrastemma  is  described  as  possessing 
two  long  primary  trunks,  which,  anteriorly,  pass  into  an  elaborate 
coil  of  loops  lying  behind  the  cerebral  ganglia  ;  among  others,  there 
pass  off  from  this  coil  an  efferent  duct,  which  opens  to  the  exterior, 
just  behind  the  brain. 

Dr.  Hubrecht  publishes  a  note  *  stating  that  he  finds  only  in  the 
Hoplonemertini  a  periphei'al  nervous  system,  where  it  has  the  form  of 
regular  dichotomously  branching  trunks  arising  from  the  lateral  nerve- 
trunks  ;  in  Carinella,  which  Dr.  Hubrecht  looks  upon  as  being  the 
most  primitively  organized  genus  of  the  Palteonemertini,  there  is, 
*  '  Zool.  Anzeig.,'  iii.  (1880)  p.  400. 


INVERTEBKATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  805 

externally  to  the  supporting  lamella,  a  layer  of  nerve-fibres  which 
forms  a  plexiform  envelopment  for  the  whole  body.  In  its  histological 
characters,  this  layer  appears  to  be  similar  to  the  ectodermal  nerve- 
fibre-layer,  found  by  the  Hertwigs  in  the  Actinias. 

In  all  the  Schizonemertini,  as  well  as  in  Polia  and  Valencinia,  the 
layer  has  the  same  histological  structure  as  in  Carinella,  but  it  differs 
in  position,  for  it  lies  between  the  circular  and  the  outer  longitudinal 
muscular  layer.  This  leads  to  the  view  that  it  is  possible  that  this 
layer  is  a  greatly  developed  ectodermal  musculature.  In  the  Hoplo- 
nemertini  this  sijecial  nervous  layer  seems  to  have  disappeared. 

Intestinal  Worms  in  the  Horse.* — H.  Krabbe  has  published  an 
interesting  account  of  the  occurrence  of  intestinal  worms  in  the  horse. 

As  the  horse  is  sj)read  over  the  greater  part  of  the  inhabited 
world,  and  under  conditions  of  life  very  varied,  it  might  be  supposed 
that,  like  man  and  the  dog,  it  would  not  be  equally  affected  with 
these  parasites,  nor  with  the  same  species.  To  determine  with  some 
degree  of  accuracy  the  Eutozoa  which  in  Denmark  are  found  in  the 
intestinal  canal  of  the  horse,  M.  Krabbe  examined,  during  the  last 
four  years,  the  bodies  of  100  horses  which  were  brought  for  anatomical 
purposes  to  the  Veterinary  College  of  Coi^enhagen,  between  the 
months  of  September  and  April  in  each  session. 

In  these  horses  he  found  Tcenia  perfoUata,  28  times  ;  T,  mamillana, 
8  times;  Ascaris  megalocephala,  16  times;  Strongylus  armatus,  86 
times  ;  S.  tetracantJius,  78  times  (in  67  horses  out  of  86) ;  and  Oxyuris 
curvula,  twice.  Of  T.  perfoUata  the  number  found  was  mostly  less 
that  25 ;  sometimes  it  was  over,  and  twice  between  100  and  200  were 
found,  while  once  no  less  than  400  were  met  with.  In  general  they 
were  lodged  in  the  caecum.  T.  mamillana  of  Mehlis,  a  Sjjecies  over- 
looked by  Dujardin  and  most  French  writers  on  the  subject,  was 
described  and  figured  by  Gurlt  in  1831  ;  generally  less  than  25,  but 
sometimes  up  to  72,  were  met  with,  mostly  in  the  anterior  part  of  the 
small  intestine  [T.  plicata  R.  was  never  met  with).  The  Ascaria 
never  occurred  in  larger  numbers  than  11.  S.  armatus  was  never  met 
with  in  the  small  intestine ;  in  the  caecum  it  was  common ;  much  less 
so  in  the  first  portion  of  the  colon,  where  very  fine  specimens  of  a 
dark  bluish  red  colour  were  found  ;  generally  the  number  met  with 
was  below  25,  but  once  nearly  200  were  found.  Of  1409  samples, 
1029  were  females  and  380  males.  S.  tetracanthus  was  found  in  the 
caecum  and  throughout  the  colon,  and  Oxyuris  curvula  also  in  the  colon. 

The  literature  of  this  subject  would  appear  to  be  very  scanty, 
and  the  author  ho2)es  tliat  the  attention  of  veterinary  surgeons  in 
other  parts  of  tbe  world  may  bo  attracted  to  it.  Ample  oppor- 
tunities of  following  it  up  exist  in  British  India,  America,  and  the 
Cape  of  Good  Hope  district. 

Parasites  of  Helminthes.t — M.  Moniez  directs  attention  to  a 
somewhat   curious    fact.       The   EchinorhyncJii   have    generally  been 

•  'Overs.  K.  Dansk.  VicJinsk.  Stlsk.  Forlj.,'  1880,  p. 33,  aud  'FriicIi  Rc'auniV 
1».  9.     Sc(!  '  Niituro,"  xxii.  (lf<8())  j).  217. 

t  '  Hull.  Sfi.  Dt'p.  Nur.l,'  iii.  (IHSll)  p.  liOL 


806  EECOED    OF    CUEKENT   EESEARCHES   RELATING    TO 

regarded  as  not  being  infested  by  psorosperms,  but  he  has  been  able  to 
detect  them  in  examples  of  E.  proteus.  They  were  figured  by  0.  F. 
Miiller  in  his  'Zoologia  danica,'  but  were  taken  by  him  for  the 
first  two  stages  in  the  development  of  the  young  Echinorhynchus. 

In  the  same  note  he  states  that  in  Tcenia  expansa  he  has  seen  a 
large  number  of  corpuscles  very  closely  allied  to  the  organism  which 
produces  pebrine.  Once,  also,  he  detected  them  in  T.  denticulata,  but 
the  specimen  in  question  was  associated  with  an  example  of  the  former 
species,  which  was  full  of  these  organisms. 

Bodies  found  on  Meat.* — On  the  refuse  of  certain  meat  from  the 
abattoir  at  Nancy,  M.  Poincare  has  found  bodies,  which  were  in  no 
way  encysted,  among  the  muscular  fibres,  to  which,  however,  they 
were  so  intimately  attached  as  to  seem  at  first  sight  as  if  they  occu- 
pied a  zone  in  the  cavity  of  the  sarcolemma ;  they  were  found  to  be 
independent  of  it,  and,  indeed,  no  examination  is,  in  most  cases,  neces- 
sary to  demonstrate  this,  as  the  bodies  become  isolated  spontaneously. 
The  body  is  cylindrical,  with  two  conical  extremities,  with  a  distinct 
cuticle,  and  presenting  a  number  of  lines  which  circumscribe  the 
large  cells ;  within,  there  is  a  granular  mass,  but  no  distinct  signs  of 
internal  organization  were  to  be  made  out.  The  bodies  were,  on  the 
average,  0  •  05  mm.  wide,  and  0  •  28  mm.  long  ;  the  size  varied  a  good 
deal.  Notwithstanding  the  absence  of  any  distinct  organization,  they 
appear  to  be  independent  organisms,  and  it  is  suggested  that  they  are 
examples  of  some  one  phase  in  the  metamorphoses  of  tsenioid  forms. 
For  the  moment,  the  author  contents  himself  with  directing  attention 
to  their  presence. 

Floscularia  ornata.f — Mr.  T.  B.  Eosseter,  when  watching  this 
floscule,  saw  enter  its  mouth  a  large  brown  mass  which  was  too 
large  to  pass  from  the  funnel  into  the  vestibule ;  the  latter  began  to 
swell,  the  contractile  rim  gradually  opened,  the  whole  of  the  setae  on 
the  lobes  were  turned  inwards  and  thrust  down  the  trochal  disk  on  to 
the  brown  jelly-like  mass,  piercing  it  like  so  many  needles,  thrusting 
it  from  the  vestibule  through  the  contractile  rim  into  the  mouth, 
which  instantly  became  distended,  and  the  prey  passed  down  into  the 
stomach;  the  lobes  were  drawn  upwards,  and  again  resumed  their 
feather-like  appearance. 

Prothelminthus,  a  new  low  Vermian  Form.| — The  species 
described  by  M.  Jourdain  under  this  new  generic  name  was,  like 
Intoshia  leptoplance  of  Giard,  found  on  the  Planarian  Leptoplana 
tremellaris ;  it  was  found,  however,  on  the  surface  of  the  body,  instead 
of  in  the  gastric  caeca,  but  is,  notwithstanding,  probably  the  same 
species.  It  lives  alone  in  a  cavity  in  the  integuments  of  the  worm, 
similarly  to  IntosMa  linei,  as  discovered  by  Giard. 

There  are  two  kinds  of  individuals.  Both  have  a  vermiform 
shape,  are  roimded  at  both  ends,  and  divided  into  more  or  less  distinct 
segments,  and  are  entirely  covered  by  cilia,  of  which  the  terminal 

*  'Comptes  Rendus,'  xci.  (1880)  p.  177. 

t  '  Sci.-Gossip,'  1880,  p.  182. 

X  '  Rev.  Sci.  Nat.,'  ii.  (1880)  p.  68  (1  plate). 


INVERTEBRATA,   ORTPTOOAMIA,   MICROSCOPY,   ETC.  807 

ones  are  the  larger  and  more  rigid.  A  digestive  cavity  appears  to 
extend  throughout  the  body ;  at  one  end,  surrounded  by  hairs,  is  a 
dilatable  opening,  which  is  lined  by  crystalline  rods,  as  in  Chilodon. 
No  other  organs  have  been  found.  The  only  movements  detected 
were  those  of  rotation  round  the  long  axis  of  the  body,  caused  only  by 
the  external  cilia,  and  of  a  bending  and  displacement  of  segments, 
probably  due  to  contractile  mesodermic  tissue. 

Of  the  two  kinds  noticed,  the  larger  are  the  females,  which  vary 
from  'IS-*  15  mm.  in  length,  with  a  breadth  of  '03  mm.;  they 
are  dark  green,  and  the  surface  appears  to  be  finely  punctate.  There 
are  nine  or  ten  quite  distinct  segments,  followed  by  a  terminal  part 
in  which  the  segments  are  very  indistinctly  marked,  but  which  per- 
haps represents  five  more,  thus  agreeing  in  the  main  with  the  species 
figured  with  some  hesitation  as  Intoshia  leptoplance  by  Keferstein. 
The  smaller  individuals  are  less  numerous,  and  measure  •  1  by  "02  mm. 
They  are  hardly  at  all  pigmented  except  at  the  posterior  extremity ; 
they  are  probably  the  males,  but  no  male  elements  have  been  found 
in  them.  The  segaaents  ajjpear  to  be  about  twelve  or  thirteen.  Some 
individuals  show  a  strong  median  constriction,  and  some  are  found 
in  a  kind  of  cyst.  If  the  pi-esence  of  a  digestive  canal  with  two 
openings  should  be  established,  the  species  will  have  to  be  excluded 
from  the  Orthonedida.  The  name  given  to  it  (subject  to  its  not  being 
proved  to  be  identical  with  I.  leptoplance)  is  P.  Hessei. 

New  Synthetic  Type.* — At  a  meeting  of  the  Zoological  Section 
of  the  Eussian  Association  of  Naturalists,  A.  Kowalevsky  gave  an 
account  of  Coeloplana  Metschnikoivii,  a  new  form  which  lives  on 
Zostera  in  the  Eed  Sea,  and  which  constitutes  a  type  intermediate 
between  the  Coelentcrates  and  the  Planarian  worms. 

In  its  outer  form  it  resembles  a  Planarian ;  it  is  grey  above,  white 
below,  and  about  three  lines  in  length  by  two  in  breadth.  Like  all 
Planariaus,  it  crawls  on  the  whole  ventral  surface,  in  the  middle  of 
which  is  a  slit-like  oi)ening  communicating  with  a  four-lobed  stomach 
which  resembles  most  nearly  the  "  funnel "  of  the  Ctenophora  ;  from 
it  originate  a  large  number  of  canals  which  radiate  to  the  perij)hery 
of  the  auimal  and  open  into  a  ring  canal  which  bears  many  csecal 
appendages.  On  the  dorsal  surface,  almost  directly  over  the  mouth, 
is  a  vesicle  containing  a  number  of  vibratilc  otolitlis.  On  either  side 
of  this  otocyst  is  a  sheatli  from  which  can  be  protruded  a  long  retrac- 
tile tentacle.  Each  tentacle  is  branched  and  corresjionds  in  shape  to 
those  of  Cydippe  and  Eschscholtzia,  only  they  have  no  central  canal, 
but  are  composed  of  muscles.  The  nervous  system  and  genitalia  were 
not  observed.  The  whole  surface  of  the  body  is  covered  with  vibratile 
cilia. 

Echinodermata. 

Development  of  the  Echinodermata.f — Dr.  Goethe  states  that, 
when  lately  looking  through  some  preparations  of  Bipinnaria  made 
by  Herr  Meyer  at  Naples,  he  observed  a  mode  of  development  of  the 

*  'Zool.  Anztip.,'  iii.  (18S0)  p.  140  ;  see  'Am.  Natural.,' xiv.  (1880)  p.  531. 
t  Ibid.,  Hi.  (1880)  p.  324. 


808  IIECOUP    OF    CUUKENT    KKSEAROIIES    RELATING    TO 

vaso-poritononl  system  which  Joes  uot  soom  to  have  been  liithoito 
noticed.  Botwooii  an  apical  civcal  sac  auil  t.ho  ivsophagus  ho  saw  i)u 
either  side  au  outgrowth,  which  was  partly  soparatocl  by  a  constriction 
from  tho  rest  of  the  entorou.  lu  other  preparatitnis  ho  saw  these 
processes  separated  from  tho  enteron,  with  tlio  stone-caual  inunedi- 
ntely  between  them.  Tho  dmible  sac  thus  formed  became,  later  on, 
very  uuecpially  developed  on  the  two  sides.  This  observatit)n  is  in- 
teresting as  allying  the  Asterida  on  tho  one  hand  with  tho  Echinoidea 
and  Ilolothuroida,  and  on  tho  other  with  tho  Crinoida.  In  referenco 
to  this  hist  group  the  author  takes  the  opportunity  of  stating  that  ho 
WHS  wri>ng  in  following  Johannes  Miiller  in  suj)posing  that  tho  tirst 
oritico  which  appears  between  tho  tirst  and  second  ciliated  band  is 
completely  obliterated,  and  ho  has  now  been  convinced  by  tho 
demonstrations  of  Metschuikoft'  that  tho  tirst  baud  docs  uot  bccomo 
complete  until  the  orifice  comes  to  lie  within  its  area. 

Echinoderms  of  the  Norwegian  North  Sea  Expedition.*— Messrs. 
Danielssen  and  Koren  continue  their  account  of  the  llolothurians 
belonging  to  Dr.  Theel's  group,  tho  Elpidida>,  by  very  fully  describing 
a  form  assigned  to  a  new  genus  (tho  third  now  launvn),  and  to  bo 
called  Kol'ja  hiialiua.  Their  specimens  do  not  exceed  50  nun.  in  length. 
It  is  very  distinctly  bilateral,  tho  back  being  strongly  convex ;  its 
anterior  edge,  above  tho  tentacles,  forms  a  kind  of  collar,  with  six 
conical-pointed  papilliv*.  Tho  mouth  looks  in  the  same  direction  as 
tho  ventral  side  of  the  body.  Of  tho  parts  of  tho  skin,  certain  globular 
nucleated  glands  with  thick  walls  lying  between  tho  cuticle  and 
coriiim  are  to  bo  sjiecially  noticed ;  they  probably  aro  mucous  in 
character.  Of  tho  three  forms  of  spicula,  one  which  is  narrow,  sinuous, 
and  doubly  pointed,  but  smaller  than  in  Irpa,  is  found  veutrally ;  the 
largo  forms  aro  also  curved,  and  more  or  less  spinous;  tho  former 
measure  -Oi-i  by  -002  mm.  ;  the  latter,  -357  by  -008  mm. ;  the  third 
kind,  belonging  to  the  oral  disk,  is  either  linear,  angulated,  and  spined, 
or  rosette-shaped,  or  reticular.  Of  the  internal  skeleton  tho  calca- 
reous rings  are  rather  rudimentary  :  the  five  pieces  which  compose 
them  are  very  thin,  and  of  almost  uniform  thickness  throughout.  Tho 
oral  disk  carries  ten  tentacles  ;  the  anus  is  dorsal ;  the  sexes  aro 
separate ;  no  anal  appendages  exist.  Found  off  uotth  of  Norway,  at 
7r59'N.  lat.,  1200  fathoms. 

A  second  new  generic  typo  is  described  as -cloajj/Ao/roc^HS  mtrahilis. 
It  is  cylindrical,  apodal,  posteriorly  rounded  off';  tho  sexes  aro 
distinct ;  no  anal  res])iratory  appendages ;  skin  provided  with  two 
kinds  of  calcareous  spicules,  the  one  with  alato  rays  and  with  long 
inwardly  directed  teeth  on  the  circumference,  the  other  more  than  twice 
as  large,  and  with  long  tooth  projecting  outwards  from  the  perijihery ; 
there  are  twelve  uon-retractilo  tentacles  ;  the  locality  is  73^  47'  N.  hit., 
11"-'  21'  E.  long.  ;  the  depth,  7G7  fathoms. 

Atd-tiwdcrma  is  a  third  new  genus,  represented  by  two  species, 
.■I.  Jffn'i/)!!ii  and  otjiiie,  found  at  depths  less  than  500  fathoms  ;  the 
chief  characters  show  the  body  to  bo  cylindrical,  the  anterior  end 

*  •  Nyt  Mag.  Nuturvid.,'  x.w.  (1870)  p.  83,  3  (t>)  I'latcs. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  809 

truncate,  the  oral  disk  provided  with  fifteen  oblong  depressions,  con- 
taining the  saino  number  of  i)apilliform  tentacles,  and  alternating 
with  fifteen  tubular  processes  also  on  the  disk  ;  the  posterior  eiid  is 
produced  tail-wise,  tlie  cloacal  opening  surrounded  by  five  papilhe ; 
the  skin  carries  perforated  papilho  provided  with  peculiar  calcareous 
bodies,  consisting  of  five  to  six  stellately  arranged  sjioon-like  rods 
from  tlio  centre  of  which  project  tlic  anchors ;  feet  absent ;  two  anal 
appendages.  A.  J<:Jfreij8ii  was  found  chiefly  in  the  most  northern  fiords 
of  Finmark  ;  the  other  species  at  IT  27'  N.  lat.,  2iP  51'  E.  long. 

The  other  species  recorded  by  them  are  Myriotrodiua  Rinlcii 
Stcenstrup,  M.  hrevis  Huxley,  M.  Itinldi  Theel  fwliich  differs  from 
Steenstrup's  species  in  having  more  tentacular  cirrhi,  &c.j,  Oliyotrochus 
vitreua  Sars,  Trochostoma  boreale  Sars,  T.  arcticum  Marenzeller. 

Synthetic  Type  of  Ophiurid.* — Professor  P.  Martin  Duncan 
describes  a  very  remarkable  Opliiuran  which  forms  part  of  a  collec- 
tion obtained  by  Dr.  Wallich,  during  his  voyage  in  II.M.S.  '  Bulldog,' 
in  the  year  18G0,  off  the  coast  of  East  Greenland.  The  Ophiuran  was 
presented  by  him  to  tliis  Society. 

The  Opliiuran — PolDpliolis  echinala — -j^^j-  inch  long,  and  tlie  body 
■j\j-  inch  in  diameter,  came  up  with  the  sounding  apparatus  from  off  tho 
sea-floor  at  a  depth  of  228  fathoms,  about  50  miles  north  and  east  of 
Capo  Valloe,  East  Greenland,  and  about  200  miles  from  Capo  Fare- 
well, date  July  10,  18G0,  lat.  60^  42'  N.,  long.  W  42'  W.  The 
"cup"  came  up  full  of  fragments  of  granite  and  felspar,  to  which 
were  adherent  small  corallines.  Some  of  them  were  very  delicate, 
and  their  perfect  condition  indicated  an  undisturbed  state  of  the 
bottom  water  where  they  occurred.  There  was  a  sudden  decrease  of 
depth  close  to  the  spot,  and  the  water  shallowed  578  fathoms  in 
three  miles. 

Although  a  young  form,  this  specimen  presents  tho  normal 
structures  of  an  Ophiuran,  and  it  is  in  no  way  deformed  or  abortive. 
The  extreme  simplicity  of  tho  oral  apparatus  is  in  itself  remarkable  ; 
there  are  true  teetli,  but  the  spines  on  the  side  moutli-shields  are  tho 
only  mouth  pa2)ilhc,  and  they  are  so  called  because  it  is  the  fashion, 
erroneously,  so  to  call  all  growtlis  from  the  sides  of  tho  jaw-angles 
and  side  mouth-sliields.  The  use  of  the  small  spines  on  the  side 
mouth-shields  is  that  of  tentacle-scales,  and  they  can  have  nothing  to 
do  with  alimentation.  This  remark  holds  good  in  tho  majority  of 
instances  where  the  spine  arises  from  tho  jaw,  close  to  tho  side 
mouth-shield  and  tentacle  opening. 

There  are  no  tootli-papilla),  and  the  knob-liko  projection  witliin 
the  jaw  plate  beneatli  the  true  teeth,  so  like  that  of  some  Amphiurans, 
is  not  seen  on  all  tlie  angles.  It  comes  doubtfully,  however,  within 
tho  description  of  mouth-papillro,  and  appears  to  be  a  true  tootli. 
The  regularity  of  the  pentagon  surrounding  tho  oral  apparatus  is 
very  striking,  and  so  is  the  extreme  separation  of  the  jaw-angUs, 
much  of  wliieh,  however,  may  be  duo  to  ixid-morlem  contraction.  All 
tho  plates  on  tho  upper  surface  of  tho  disk  have  separate,  broad  baaed, 

*  •  Journ.  Lina.  tioc.'  (Zoul.),  xv.  (lS8'J)  i».  16. 


810  EECOBD    OF   CURRENT   RESEARCHES   RELATING   TO 

two  or  three-tliorned,  short  spinules  on  their  edges,  and  rarely  else- 
where, but  the  spinulation  is  not  distinct  between  them.  The  radial 
shields  have  the  greatest  number  of  spinules  on  them.  All  the  spines 
on  the  side  arm-plates  project  at  right  angles  to  the  arm,  and  the 
hooks  are  glassy  at  their  top.  The  combination  of  Amphiuran 
characters  and  those  of  OpMotlirix  is  thus  remarkable. 

Haemoglobin  in  the  Aquiferous  System  of  an  EcMnoderm.* — 
M.  Foettinger  reports  the  important  discovery  of  hsemoglobin  in  an 
O^Yanxidi—OpMactis  virens.  In  the  elements  discovered  by  Simroth 
in  the  water-vascular  system  of  this  species,  the  writer  was,  with 
living  specimens,  enabled  to  detect  a  bright  red  colouring  matter. 
Spectral  analysis  revealed  the  presence  of  the  two  bands  character- 
istic of  the  oxyhaemoglobin  of  the  Vertebrata.  The  cells  in  which  it 
is  contained  were  seen  to  be  nucleated,  but  in  addition  to  these  there 
were  also  found  a  number  of  free  nuclei  and  small  corpuscles,  which 
were  also  charged  with  haemoglobin.  The  author  would  seem  to 
agree  with  Simroth  in  recognizing  the  presence  of  a  vascular  system, 
independent  of  the  water-vascular,  and  charged  with  a  nutrient  func- 
tion ;  this  contains  a  colourless  liquid.  On  the  other  hand,  the  system 
with  the  red  corpuscles  has  a  respiratory  function. 

Buccal  Skeleton  of  the  Asterida.f — In  this  note  M.  Viguier, 
while  replying  to  some  criticisms  of  Dr.  Hubert  Ludwig,|  reaffirms 
the  existence  of  two  parts  in  the  "support  of  the  tooth."  The  fact 
that  there  is  no  trace  of  any  fusion  is  relied  upon  greatly  by  Ludwig, 
but  Viguier  points  out  that  in  reality  the  difference  between  them 
lies  in  the  fact  that  what  has  been  taken  for  the  first  ambulacral 
piece  is  composed  of  two,  which  always  become  separated  under  the 
action  of  potash.  This  is  a  statement  of  fact,  which  it  will  be 
possible  to  verify  or  to  disprove. 

New  Cretaceous  Comatulae.§ — Mr.  P.  Herbert  Carpenter  describes 
five  new  species  of  Antedon  from  British  cretaceous  deposits,  two  of 
them  in  the  possession  of  the  Eev.  P.  B.  Brodie,  the  rest  in  the  collec- 
tion of  the  British  Museum.  The  species  are  : — Antedon  perforata  and 
A.  Lundgreni,  from  the  upper  chalk,  Margate ;  A.  striata,  from  the 
upper  chalk,  Dover ;  A.  laticirra,  from  the  chalk  of  Wylye,  Wiltshire  ; 
and  A.  incurva,  from  the  upper  greensand,  Blackdown.  The  author 
further  gives  a  tabular  key  to  the  known  English  cretaceous  species 
of  Antedon,  and  in  conclusion  refers  to  certain  peculiarities  in  the 
structure  of  these  fossils,  aj^parently  subservient  to  the  circulation  of 
water  in  their  interior. 

Coelenterata. 

Structure  and  Origin  of  Coral  Reefs  and  Islands.|| — Darwin's 
theory  may  be  said  to  rest  on  two  facts — the  one  physiological,  and 

*  'Bull.  Acad.  Koy.  Belgique,'  xlix.  (1880)  p.  402. 
t  'Arch.  Zool.  exp.  et  gen.,'  viii.  (1880)  p.  1. 
X  See  this  Journal,  ante,  p.  446. 
§  '  Quart.  Joum.  Geol.  Soc.,'  xxxvi.  (1880). 

II  See  'Nature,'  xxi.  (1880)  p.  351.  Abstract  of  paper  read  at  the  Eoyal 
Society  of  Edinburgh. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  811 

the  other  physical — the  former,  that  those  species  of  corals  whose 
skeletons  chiefly  make  up  reefs  cannot  live  in  depths  greater  than 
from  20  to  30  fathoms ;  the  latter,  that  the  surface  of  the  earth  is 
continually  undergoing  slow  elevation  or  subsidence. 

The  corals  commence  by  growing  up  from  the  shallow  waters 
surrounding  an  island,  and  form  a  fringing  reef  which  is  closely 
attached  to  the  shore.  The  island  slowly  sinks,  but  the  corals  con- 
tinually grow  upwards,  and  keep  the  upper  surface  of  the  reef  at  a 
level  with  the  waves  of  the  ocean.  When  this  has  gone  on  for  some 
time  a  wide  navigable  water  channel  is  formed  between  the  reef  and 
the  shores  of  the  island,  and  we  have  a  barrier  reef.  These  processes 
have  but  to  be  continued  some  stages  fui-ther,  when  the  island  will 
disappear  beneath  the  ocean,  and  be  replaced  by  an  atoll  with  its 
lagoon  where  the  island  once  stood. 

According  to  this  simple  and  beautiful  theory,  the  fringing  reef 
becomes  a  barrier  reef,  and  the  barrier  reef  an  atoll  by  a  continuous 
process  of  development. 

Professor  Semper,*  during  his  examination  of  the  coral  reefs  in 
the  Pelew  group  experienced  great  difficulties  in  aj^plying  Darwin's 
theory.  Similar  difficulties  presented  themselves  to  the  author  of 
this  paper,  Mr.  John  Murray,  of  the  '  Challenger '  Expedition,  in  those 
coral  regions  visited  during  the  cruise  of  the  '  Challenger.'  The  object 
of  the  present  paper  is  to  show,  first,  that  while  it  must  be  granted  as 
generally  true  that  reef-forming  species  of  coral  do  not  live  at  a 
depth  greater  than  30  or  40  fathoms,  yet  that  there  are  other  agencies 
at  work  in  the  tropical  oceanic  regions  by  which  submarine  elevations 
can  be  built  up  from  very  great  dejiths  so  as  to  form  a  foundation  for 
coral  reefs  ;  second,  that  while  it  must  be  granted  that  the  surface  of 
the  earth  has  undergone  many  oscillations  in  recent  geological  times, 
yet  that  all  the  chief  features  of  coral  reefs  and  islands  can  be 
accounted  for  without  calling  in  the  aid  of  great  and  general  sub- 
sidences. 

The  most  recent  charts  of  all  coral  reef  regions  have  been 
examined,  and  it  is  found  possible  to  explain  all  the  phenomena  by 
the  principles  advanced  in  the  paper,  while  on  the  subsidence  theory, 
it  is  most  difficult  to  explain  the  appearance  and  structures  met  with 
in  many  grou2)s ;  for  instance,  in  the  Fiji  Islands,  where  fringing 
reefs,  barrier  reefs,  and  atolls  all  occur  in  close  proximity,  and  where 
all  the  other  evidence  seems  to  point  to  elevation,  or  at  least  a  long 
period  of  rest.  In  instances  like  the  Gambicr  gi'oup  the  reefs 
situated  on  the  seaward  side  of  tlic  outer  islands  would  grow  nioro 
vigorously  than  those  towards  the  interior ;  they  would  extend  in  the 
direction  of  the  shallower  water,  and  ultimately  would  form  a  con- 
tinuous barrier  around  the  whole  group.  The  distinguishing  feature 
of  the  views  now  advanced  is  that  they  do  away  witli  the  great 
and  general  subsidences  required  by  Darwin's  theory,  and  are  in 
harmony  with  Dana's  views  of  the  great  antiquity  and  permanence  of 
the  great  ocean  basin,  which  all  recent  deep-sea  researches  appear  to 
support. 

•  '  Zuitsclir.  wibs.  Z<x^l.,'  xiii.  p.  50;5. 


812      KECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

The  results  of  the  paper  may  be  summarized  thus  : — 

(1)  Foundations  have  been  prepared  for  barrier  reefs  and  atolls  by 
the  disintegration  of  volcanic  islands,  and  by  the  building  up  of  sub- 
marine volcanoes  by  the  deposition  on  their  summits  of  organic  and 
other  sediments. 

(2)  The  chief  food  of  the  corals  consists  of  the  abundant  pelagic 
life  of  the  tropical  regions,  and  the  extensive  solvent  action  of  sea- 
water  is  shown  by  the  removal  of  the  carbonate  of  lime  shells  of  these 
surface  organisms  from  all  the  greater  depths  of  the  ocean. 

(3)  When  coral  plantations  build  up  from  submarine  banks,  they 
assume  an  atoll  form,  owing  to  the  more  abundant  supply  of  food  to 
the  outer  margins,  and  the  removal  of  dead  coral  rock  from  the 
interior  portions  by  currents,  and  by  the  action  of  the  carbonic  acid 
dissolved  in  sea-water. 

(4)  Barrier  reefs  have  built  out  from  the  shore  on  a  foundation  of 
volcanic  debris,  or  on  a  talus  of  coral  blocks,  coral  sediment,  and 
pelagic  shells,  and  the  lagoon  channel  is  formed  in  the  same  way  as  a 
lagoon. 

(5)  It  is  not  necessary  to  call  in  subsidence  to  explain  any  of  the 
characteristic  features  of  barrier  reefs  or  atolls — all  these  features 
would  exist  alike  in  areas  of  slow  elevation,  of  rest,  or  of  slow 
subsidence. 

(6)  All  the  causes  here  appealed  to  for  an  explanation  of  the 
structure  of  coral  reefs  are  proximate,  relatively  well  known,  and  con- 
tinuous in  their  action. 

New  Mode  of  Reproductioii  among  the  Hydroida,* — Dr.  Goette 
describes  the  structure  and  history  of  a  new  species  of  Hydroid- 
polyp,  which  he  discovered  on  a  Campanularian  during  his  recent 
visit  to  Naples ;  he  calls  it  Hydrella  ovipara,  and  describes  it  as 
having  a  creeping  stolon  which  bears  here  and  there  simple  branches, 
which  are  scarcely  1  mm.  in  length,  and  terminate  in  a  hydranth.  A 
skeletal  tube,  irregularly  annulated  at  its  base,  invests  the  body,  but 
does  not  form  a  proper  hydrotheca.  Remarkable  stages  were  observed 
in  the  characters  of  the  stalk,  which  was  in  some  cases  completely 
atrophied  at  its  middle,  so  as  to  be  reduced  to  a  thin  filament,  and  to 
be  comj^osed  only  of  the  ectoderm.  It  would  appear  that  H.  ovipara, 
like  some  other  Hydi'oids  (e.  g.  Eudendrium),  undergoes  a  degeneration 
of  some  of  its  polyps  at  the  period  of  sexual  maturity ;  the  ova  are 
developed  from  endodermal  cells,  and  within  the  stalk  ;  here  the  eggs 
undergo  their  further  development,  instead  of  being  conveyed  into  a 
gonophore,  while  the  remaining  i)art  of  the  neighbouring  endoderra 
undergoes  atroj^hy.  These  observations  are  sufficient  to  demonstrate 
that  there  is  no  polymorphism  and  no  alternation  of  generation  in  this 
species.  With  this  we  should  note  the  fact  that  in  many  species  of 
Lafoeida  no  alternation  has  yet  been  detected,  and  it  is  possible  that 
there  is  none  to  be  observed. 

Forms  a  little  more  distant,  e.  g.  CordylopJiora,  exhibit  an  incom- 
plete development  of  this  alternation  of  generation,  ova  being  deve- 

*  'Zool.  Anztig.,'  iii.  (1880)  p.  352. 


INVERTEBRATA,    CRYPTOftAMIAj    MICROSCOPY,    ETC.  813 

loped  in  some  of  the  sterile  polyps ;  in  all  others  the  alternation  is 
complete.  Though  the  phcuomeuou  is  of  course  associated  with  poly- 
raorjjhism,  it  is  not  to  be  regarded  as  sim^ily  due  to  it ;  the  limitation 
of  sexual  reproduction  to  some  of  the  similar  individuals  of  a  stock, 
and  the  limitation  of  the  gonojAore  to  the  mature  polyps,  is  to  be 
regarded  as  a  process  anterior  to  the  truly  secondary  phenomena  of 
polymorphism. 

Orig^in  of  the  Generative  Cells  in  the  Hydroida.* — Dr.  Weiss- 
man,  in  continuation  of  his  researches  t  has  discovered  that  the 
male  generative  cells  may  arise  in  the  coenosarc.  Basing  his  result 
on  what  he  was  able  to  observe  in  Plumtdaria  echinidafa,  we  find 
him  saying  that  in  the  male,  as  well  as  in  the  female,  gonaugia  were 
developed  at  points  on  the  stalk  thus ;  a  small  group  of  ovarian  or 
seminal  cells  are,  first  of  all,  found  in  the  endoderm,  without  any 
indications  whatever  of  any  change  in  the  perisarc  or  ectoderm. 
Around  this  primitive  reproductive  organ  there  become  developed  a 
special  cap  of  cells  of  the  ectoderm  ;  these  cells  become  very  remark- 
ably and  specially  modified,  are  set  at  right  angles  to  the  supporting 
membrane,  and  contain  in  the  outer  jjortion  a  fluid  ;  this,  which  is  pro- 
bably a  secretion,  causes  an  outswelling  of  the  perisarc.  In  this  last 
a  cleft  gradually  appears,  which  grows  deeper  and  deeper ;  through 
this  grow  out  the  ectodermal  and  endodermal  cells,  covered  by  the 
perisarc,  and  a  gonangium  is  thus  developed. 

The  further  generalization  that  in  CorchjlopTiora  the  ovarian  cells 
arise  in  the  trunk  and  not  in  the  stalks  of  the  hydranths,  is  supported 
by  the  observation  that  the  groups  of  ovarian  cells  are  to  be  found  in 
quite  young  hydrauth-buds,  before  any  tentacles  are  develojied,  and 
while  the  stalk  is  still  quite  short.  Of  course  this  mode  of  forming 
generative  cells  is  not  found  in  all  Hydroids  (e.  g.  Tubularia)  ;  so 
that  with  regard  to  the  mode  of  origin  of  their  generative  cells,  Hydroida 
may  be  ranged  in  two  series  ;  in  one  the  generative  cells  arise  in  the 
ccenosarc,  and  the  so-called  generative  individuals  are  of  secondary 
origin ;  in  the  other  the  generative  individuals  are  primary,  and  it  is 
only  in  them  that  the  generative  cells  arc  developed  ;  the  former  are 
Coenogenous,  the  latter  Ulastogenous  Hydroids.  Further  speculation 
as  to  the  phylogcnetic  bearing  of  these  observations  is  deferred  for  the 
present. 

Porifera. 

Occurrence  of  Foreign  Spicules  in  Sponges.t — In  two  cases,  Mr. 
S.  O.  Ridley  has  sliown  this  interesting  and,  to  tlic  working  zoologist, 
important  phenomenon  to  have  occurred.  A  species  of  Ciocalypfa, 
characterized  by  a  fibre  which  is  almost  wholly  composed  of  long, 
singly  pointed  ("acuate  "")  sjncules,  with  a  simple  rounded  head  and 
sharp  i)oiut,  and  by  the  almt)st  absolute  bareness  of  the  outer  or  dermal 
membrane  in  the  natural  condition,  was  found  to  contain  in  tlic  latter, 
in  addition  to  tlic  terminal  spicules  of  the  fibre  proper,  certain  long 
smooth  spicules  of  about  tlie  same  jinqioi-tiojis,  but  with  a  slight  oval 

*  '  Z(.<)1.  Anzci;,'.,'  iii.  (1880)  p.  'Mil.  t  ll>i<l.,  p.  220. 

X  '  Jonrn.  Linn.  Hm:'  (Z.>o).),  xv.  (1880)  p.  Hit. 


814  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

head  at  the  rounded  end ;  these  were  apparently  part  and  parcel  of 
the  sponge,  both  on  account  of  their  perfect  condition  and  their 
frequent  occurrence  in  bundles,  as  if  in  nature.  They  proved,  how- 
ever, to  be  derived  from  a  species  of  Esperia,  common  in  the  same 
waters,  and  possessed  of  a  peculiarly  fragile  spicular  dermis,  the  size 
of  whose  spicules  agreed  closely  with  those  now  found,  and  which  had 
no  doubt  parted  with  them  with  great  readiness  by  the  fracture  of  its 
brittle  covering. 

The  second  case  was  that  of  a  species  of  Alehion,  with  spined 
skeleton  spicules ;  besides  other  forms,  among  the  bundles  of  short 
skeleton  spicules  and  in  the  superficial  tissues,  there  occurred,  singly 
and  in  fasciculi,  precisely  the  same  spicula  as  those  which  intruded 
into  the  Ciocalypta,  and  to  almost  as  great  an  extent.  In  the  former 
case  the  close  resemblance  of  the  intruding  to  the  skeleton  spicules 
offered  great  temptations  for  them  to  be  assigned  to  the  proper  spicule 
complement,  whereas  they  were  undoubtedly  derived  from  the  same 
species  of  Esperia. 

In  conclusion,  the  writer  points  out  the  need  of  careful  observation 
of  the  position  and  circumstances  in  which  all  spicules  occur  in  any 
sponges  examined,  as  cases  like  the  present  are  apt  to  occur  in  which 
neither  the  broken  or  partially  absorbed  condition  of  these  foreign 
bodies,  nor  their  markedly  alien  type,  are  present  to  point  to  their 
real  nature  and  prevent  their  ranking  with  the  regular  structures,  and 
perhaps  assigning  the  sponge  to  a  wrong  genus. 

Protozoa. 
Tentaculate,  Suctorial,  and  Flagellate  Infusoria.* — Prof.  Ch. 
Eobin  first  deals  with  Ophryodendron  abietinum  Claparede,  Plate  XVIII. 
(Figs.  1,  2)."|'  This  species  adheres  to  Sertularians,  chiefly  Sertularia 
pumila ;  it  may  be  globular,  ovoid,  or  discoid,  is  generally  bilobate, 
and  has  a  long  retractile  tentacle  (d),  terminated  by  a  bunch  of  mobile 
cirrhi(e);  its  diameter  is  from  -OG-'IS  mm.  It  is  strongly  attached 
by  a  short  pedicle  (a),  which  is  often  concealed  by  the  application  of 
the  whole  lower  surface  of  the  body  to  the  point  of  fixation.  When 
removed,  the  body  may  become  globular.     A  groove  (h)  divides  the 

*  '  Journ.  Anat.  Physiol.'  (Robin)  xv.  (1879)  pp.  529-83,  plates  xxxix.  to  xhii. 

t  Fig.  1. — Ophryodendi-on  abietinum,  separated  by  pressure  from  the  Sertularia 
to  which  it  adhered,  to  show  its  point  of  adhesion,  a,  and  the  general  form  of  the 
body. 

6,  i-)artially  effaced  furrow  which  divides  the  body  ;  c,  point  where  the  tentacle 
springs  from  the  body  ;  d,  transverse  folds  of  the  retracted  tentacle  ;  e,  terminal 
bunch  formed  of  the  cirrhi  of  the  extremity  of  the  tentacle. 

Fig.  2. — Ophryodendron  after  compression,  the  furrow  having  thereby  dis- 
appeared. 

o,  d,  e,  as  Fig.  1  ;  c,  Ii,  i,  a  lobed  gemmiform  body ;  /,  worm  or  larva  of  parasitic 
worm  ;  j,  k,  the  hook  by  which  it  adheres. 

Fig.  3. — Acinetopsis  rara  Ch.  R.  a,  pedicle  ;  6,  c,  theca  ;  d,  e,  f,  extensile  and 
retractile  tentacle. 

Fig.  4. — Acineta  patula  Ehr.,  the  body  of  which  is  suspended  as  it  were  in  its 
shell,  which  resembles  a  pedicellated  cup. 

Fig.  5. — Aciyieta  tuherosa  Ehr.,  front  view.  /,  the  pedicle  and  its  insertion  at 
the  lower  extremity  of  the  body,  e  ;  g,  g,  tubercles. 

Fig.  6. — Side  view  of  the  same. 

Fig.  7. —  Trichodina  Scorpenm  Ch.  R.,  side  view,  o,  superior  dorsal  or  con- 
tractile portion  of  the  body,  often  more  or  less  contracted  and  flattened  ;  b,  crown 


JOTTRN.R   MIlTR.  S0C.V0L.3II.  PL.  .XiZEQ. 


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f 


Wcsf,N€«-.^<.«  fcO°].(>i.. 


Fig.  1-2.    Uphpyoclciulroi'i    abieimum.     3.  Aemetopsis    rara 
4.  Aciyieta.   patula.    5-6.  A.  tuberosa.  7- S.'Jri  rkodiTui.   Scoj?pe: 
9.   PoAopliryo    LiyiicjLfii . 


10  rr 


joirRN". R.MiCR.  soc.VDi..nr. Pi,.xrK:. 


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Fic^.   10-14.    Podopln->a  .      15  Conodoi5i<T|U    hoU-yUt 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY^    ETC.  815 

body  superficially  into  two  unequal  halves,  being  seldom  wanting.  It 
shows  an  extraordinary  resistance  to  the  action  of  reagents,  even  hydro- 
chloric and  nitric  acids  merely  hardening  and  rendering  it  more 
transparent !  Its  substance  is  greyish  and  granular,  more  transparent 
towards  the  surface,  where  it  is  limited  by  a  tough,  flexible,  refriugent 
layer,  not  separable  from  it,  and  from  '001- "002  mm.  in  thickness. 
The  only  organized  contents  consist  of  minute  granules,  which  have 
no  resemblance  to  trichocysts.  Buds  (c,  h)  bearing  superficial  protu- 
berances (j)  are  produced ;  their  tissues  are  directly  continued  from 
those  of  the  parent.  Tlie  tentacle  is  inserted  in  the  groove  or  the 
portion  furthest  from  the  pedicle  if  tliat  is  not  present ;  the  cuticle 
of  the  body  is  continued  over  it,  being  wrinkled  (d)  when  it  contracts, 
and  also  forms  a  distinct  band  in  the  centre  of  the  tentacle  ;  that  part 

of  large  cilia  ;  c,  non-contractile  discoid  portion  of  the  body  with  the  pultiatilo 
vesicle ;  d,  lower  crown  of  tine  locomotor  cilia. 

Fig.  8. — Lower  concave  face  of  the  same,  surronnded  by  the  crown  of  loco- 
motor cilia,  d,  and  occupied  by  the  indLUted  wheel-like  organ. 

Fig.  9. — Podophnja  Lynf/hi/ci  Ehr.,  front  view,  a,  the  insertion  of  the  pedicle, 
ab  ;  c,  transparent  theca,  the  margin  of  which  extends  beyond  the  granular  sub- 
stance of  the  body — the  latter  shows  a  pulsatile  vesicle  and  hyaline  expansions. 

Fig.  10. — J'odophrya  witlj  four  gemmae,  e,  about  one  quarter  developed. 

Fig.  11. — Large  J'odophrya  with  eight  gemniffl,  e,  at  the  close  of  their  develop- 
ment, the  extended  filaments  not  having  completely  disappeared.  The  margin 
of  the  internal  concave  face  of  tlie  gemm®  has  also  short  mobile  cilia.  In  each 
gemma  are  one,  two,  or  sometimes  three  pulsatile  vesicles. 

Fig.  12. — Phases  of  the  passage  of  a  gemma  to  the  state  of  a  fixed  pedicellate 
PodophrJ/a. 

a,  gemma  becoming  fixed,  still  provided  with  cilia,  ?,  and  with  a  verrucoso 
dorsal  face. 

b,  tlie  same,  a  quarter  of  an  hour  later,  attached  directly  by  its  lower  face  and 
not  showing  any  cilia. 

r,  tlie  same,  twelve  or  fifteen  minutes  later,  elevating  its  two  extremities,  and 
the  dorsal  face  emitting  some  pale  and  short  filaments. 

d,  e,  the  same,  at  the  end  of  two  successive  quarters  of  an  hour. 

/,  the  same,  fifteen  minutes  later,  having  already  assumed  the  general  form  of 
the  adult  ami  ^^till  directly  fixed  to  the  Sertularia  by  the  narrow  portion,  y,  where 
the  pedicle  is  inserteii. 

g,  the  same,  about  twenty  minutes  later,  with  longer  and  more  numerous 
filaments,  some  already  pointed,  A  short  pedicle,  /t,  is  developed,  and  the 
body  resembles  still  more  nearly  the  adult. 

/i,  the  same,  half  an  hriur  later,  difteiing  from  the  adult  only  by  the  shortness 
of  the  pedicle,  /,  and  the  few  coloured  granules  of  the  body. 

Fi(i.  13. — J'odophri/a  witii  the  body,  r,  reduced  to  small  (liraensions  after  the  loss 
of  the  gemma)  and  recommencing  to  throw  out  filaments,  still  short  and  blunt,  c. 

Fio.  14. — Poduj'hri/a,  with  a  non-ciliated  external  gemma,  /,  and  a  bundle  of 
short  filaments  or  blunted  suckers,  h.    a,  b,  pedicle. 

Fig.  15. —  Variety  of  Codonosiya  botrytis  Stein  ex  Ehrenberg,  with  four  rigid 
cirrhi,/,  instead  of  a  collar. 

a,  enlargement  of  the  base  of  the  pedicle  attached  to  stationary  bodies  in  the 
water;  '»,  thickening  of  the  summit  of  the  jieilicle  which  bears  the  bddy  of  each 
animal ;  e,  individual  with  the  rigi<l  cirrhi  united  by  a  mt  nibrane  forming  a 
collar  ;  /,  the  four  stitV  cirrhi  inserted  round  the  njiper  portion  of  the  animal  so  as 
to  resemble  hyaline  opercula;  i,  thin  circular  membrane  in  the  form  of  a  slightly 
raised  cuj)  inserted  on  the  hyaline  operculum  round  the  ba.se  of  the  llagellum, 
alternately  contracting  and  dilating  ;  j,  the  tlageiliun,  four  to  six  times  as  long  as 
the  body,  and  as  large  at  its  termination,  which  is  blunt,  as  at  its  iusortiou  in 
tho  miiidh^  of  the  hyaline  oiKTCiilar  summit. 

[In  tho  lettering  of  the  I'lates  for  "Lyngbei"  rend  "  Lyngbyei,"  and  for 
"  Conodosiga"  read  "  Codonosiga."] 


810  RECORD    or    CURRENT    RESEARCHES    RELATING    TO 

of  the  bocly-siibstancc  wticli  extends  into  the  tentacle  here  loses  its 
granular  character,  and  is  simply  hyaline.  The  tentacle  is  of  equal 
length  as  far  as  the  tuft  of  cirrhi ;  it  is  flattened.  The  colourless 
cirrhi  have  the  form  of  pine-needles,  are  •  03  mm.  long,  and  occur  to 
the  number  of  thirty  or  more;  in  the  extended  state  of  the  tentacle 
they  are  inserted  along  one-fifth  of  its  length  ;  in  contraction  they  are 
reduced  to  a  mere  tuft.  They  are  firmly  attached,  and,  like  the  rest 
of  the  organism,  resist  the  action  of  ordinary  reagents.  Contraction 
and  elongation  take  place  in  the  tentacle  at  intervals  of  two  minutes ; 
the  cirrhi  move  rapidly  at  the  same  time,  either  by  bending  or  other- 
wise, but  not  after  the  manner  of  either  cilia  or  flagella.  No  use  was 
observed  to  be  made  of  these  movements  for  prehension  of  food,  which 
M.  Eobin  has  never  noticed  taken  into  the  body. 

The  affinity  of  the  animal  is  with  Acinetopsis  rara.  The  cirrhi 
can  hardly  act  as  suckers,  as  Claparede  supposes,  for  they  are  flattened 
and  more  mobile  than  the  suckers  of  the  Acinetines,  and  terminate 
neither  in  a  point  nor  a  swelling  as  in  those  forms. 

Worm  parasitic  on  Ophryodendron  (Fig.  2).  A  vermiform  body  (/) 
sometimes  occurs,  rooted  to  the  body  of  the  animal,  which  has  been 
supposed  by  Claparede  to  be  a  species  or  stage  fif  the  same  animal, 
and  in  which  he  wrongly  figures  trichocysts ;  Wright  took  it  to  be 
either  a  bud  or  one  of  the  Gregarinida.  It  is,  however,  M.  Eobin 
considers,  a  larva  of  some  worm  ;  its  tissues  differ  in  character  from 
those  of  Opliryodendron  ;  it  is  separable  from  it  without  rujiture,  and 
is  fixed  by  a  special  attaching  organ  ;  it  wants  the  nucleus  and  vacuole 
of  the  Gregarina3.  The  basal  organ  of  attachment  [j,  k)  consists  of  a 
slender  chitinous  rod  embedded  in  the  worm,  with  five  or  six  short 
hooks  which  penetrate  beneath  the  cuticle  of  its  host  near  the 
tentacle.  The  body  is  greyish  and  finely  granular,  and  is  transjjarent 
at  the  anterior  end,  which  has  a  sucker -like  enlargement ;  the  prox- 
imal end  bears  an  oblique  disk-like  surface ;  dilute  hydrochloric 
acid  causes  its  substance  to  shrink  and  expose  a  homogeneous  cuticle 
to  view.  It  moves  slowly  round  on  its  peduncle,  and  resembles  in 
some  points  the  filarian  larvae  of  many  Nematode  worms. 

Acinetopsis  rara  sp.  n.  (Fig.  3),  discovered  by  M.  Eobin  at  Con- 
carneau,  is  also  a  tentaculate  Infusorium.  It  occurs  attached  to 
Sertularians,  is  from  '07- '09  mm.  long,  and  two-thirds  as  broad, 
and  lives  in  a  wine-glass-shaped  theca  (b,  c),  which  rests  on  a  very 
slender  peduncle  (a),  1  mm.  long.  The  body  is  uniformly  granular, 
greyish,  with  a  small  contractile  vesicle ;  upper  surface  flat,  an  alter- 
nately extended  contractile  tentacle  (d,  e)  proceeding  from  its  centre. 
The  tentacle,  which  measures  1  mm.  or  more  in  length  by  *  004-  •  005 
mm.  in  thickness,  is  of  uniform  thickness  throughout,  and  colourless, 
homogeneous,  and  transparent ;  by  contraction  it  is  reduced  to  a  length 
of  'OS-- 08  mm.,  with  a  breadth  of  '01  mm.,  becomes  marked  by 
transverse  striae,  and  is  now  seen  to  consist  of  a  central  filament, 
surrounded  by  a  spirally  plicated  membrane  (/).  In  extension,  it  is 
capable  of  movement  in  all  directions.  The  shell  or  theca  is  continuous 
with  the  substance  of  the  i)eduncle,  and  is  delicate,  colourless,  flexible, 
and  has  a  free  circular  edge,  beyond  which  the  body  is  never  pro- 


INVEETEBKATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  817 

truded,  though  it  may  sink  below  it,  and  may  become  detached  from 
the  thcca  at  various  points.  The  contractile  vesicle  is  only  momen- 
tarily seen. 

This  form  differs  from  the  Acinetinse  in  possessing  a  tentacle 
which  is  never  retracted  into  the  body  wholly  or  in  part,  as  is  the 
case  with  the  suckers  in  that  group,  but  which  agrees,  with  the 
exception  of  the  absence  of  cirrhi,  with  that  of  Ojphryodendron.  Both 
forms  must  be  kept  distinct  from  that  family. 

Acinefa  tiiberosa  Ehrb.  (Figs.  5  and  6,  e,f)  offers  a  good  example 
of  the  great  affinity  of  its  order  with  the  Infusoria  and  disagreement 
with  the  Rhizoi)oda,  the  characters  of  the  gemmje  giving  grounds  for 
the  one,  and  the  distinctness  from  the  rest  of  the  body  and  the  special 
character  of  the  suckers  for  the  latter  inference.  The  variations  in 
its  colour  are  due  to  the  presence  of  pale  yellow,  green,  or  orange 
granules.  Frequent  contractions  of  the  sarcode  remove  these  granules 
from  different  points  which  are  thus  left  transparent;  the  narrow 
portion,  however,  between  the  two  tubercles  (g,  g)  is  almost  constantly 
thus  transparent;  it  contains  the  one  or  two  contractile  vacuoles; 
but  the  central  part  of  the  body  is  generally  the  most  granular,  and 
is  marked  off  from  the  lateral  portions  by  two  longitudinal  ridges  on 
each  side  of  the  shell ;  these  ridges  are  absent  in  A.  patula  (Fig.  4), 
hence  the  difference  in  the  grouping  of  the  suckers  in  the  two  species, 
the  body  not  being  divided  into  separate  areas.  A  species  found  in 
stale  sea-water  had  the  lower  end  of  the  shell  rounded;  the  upper 
angles  presented,  instead  of  two  tubercles,  simply  two  perforations 
of  the  shell. 

Trichodina  Scorpence  sp.  n.  (Figs.  7  and  8)  does  not  exceed  half 
the  size  of  T.  i^ediculus  auctt.  ;  it  occurs  on  the  branchiae  of  fish  of 
the  genera  Scorpena  and  Trigla.  It  is  disk-shaped,  the  ventral  side 
concave,  a  narrower  dome-like  mass  (a)  rising  above  the  disk  (<■) ; 
the  only  cilia  present  consist  of  a  ring  of  stout  ones  (b)  projectin« 
upwards  from  the  upper  edge  of  the  disk,  and  one  of  fine  ones  {d)  in 
a  corresponding  position  on  the  lower  side,  the  latter  marking  the 
margin  of  the  denticulated  plate  described  as  "  organ  of  fixation  "  by 
Clai)aredc  and  Lachmann.  This  organ  consists  of  a  narrow  circle, 
into  the  centre  of  which  project  numerous  straight  teeth,  whilu  the 
circumference  is  lined  by  curved  ones  (Fig.  8).  The  body  and  this 
organ  especially  undergo  great  changes  after  death,  which  occurs  soon 
after  that  of  the  host. 

Gemmation  of  Podophrya  Lynghyei  Ehrb.  (Plates  XVIII.  and 
XIX.,  Figs.  9-14).  Tlie  body  substance  of  this  species,  wrongly 
referred  to  P.  gemmipnra  by  Hcrtwig,  is  not  separable  to  the 
sliglitest  extent  from  the  shell  or  theca,  though  this  is  readily 
distinguishable  from  it  by  its  contours,  its  folds,  and  its  resistance 
to  agents  which  destroy  the  former.  The  nucleus  is  elongated  and 
curved,  often  bi-  or  tri-furcatc.  In  encysted  individuiils  the  sub- 
stance of  the  body  is  withdrawn  slightly  from  contact  with  the  cyst. 
The  peduncle  (a,  h)  has  a  very  delicate  wall,  and  is  homogeneous, 
rarely  manifesting  a  longitudinal  striation. 

The  external  buds  commence  as  a  liyalinc  cup  of  sarcode  on  the 

VOL.  III.  \\    H 


818  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

upper  surface  of  the  body  (c),  in  a  vacant  space  surrounded  by  tlio 
suckers  ;  after  a  few  minutes  this  sends  out  a  number  of  conical 
elevations  (e)  regulai'ly  arranged  in  a  circle ;  they  are  transparent, 
and  after  a  few  hours  become  detached  and  swim  freely.  From  two 
to  eight  may  thus  be  produced  ;  they  are  finely  granular,  become 
elongated,  and  on  their  concave  internal  face  apjicars  a  series  of  short 
cilia  ;  it  is  in  about  half  an  hour  from  this  time  that  they  are  liberated, 
and  may  either  crawl  or  swim  by  the  aid  of  these  cilia.  The  suckers 
of  the  parent  are  sometimes  wholly  retracted  during  the  process,  and 
are  subsequently  rein-oduced  from  the  dense,  shrunken  body  (Fig.  13, 
c,  e).  These  buds  are  of  truly  external  origin,  the  only  peculiar 
condition  noticed  inside  the  parent  body  at  this  time  being  the 
prolongation  of  its  nucleus  into  as  many  filaments  as  there  are  buds, 
as  in  the  case  of  the  internal  gemmte.  The  dorsal  surface  of  the  bud 
is  convex  ;  there  are  two  contractile  vacuoles,  one  appearing  at  the 
middle  of  the  process  of  gemmation;  the  nucleus  is  about  "012  mm. 
long,  and  pale-coloured.  The  bud  ceases  crawling  (Fig.  12,  a),  and 
after  resting,  fixed  by  its  cilia  (i),  for  a  short  time,  it  loses  these,  and 
becomes  attached  by  its  entire  ventral  face  (b)  ;  the  two  lateral  mar- 
gins then  become  slightly  drawn  out,  and  short  processes  (c)  appear 
on  the  upper  surface;  the  ventral  surface  becomes  contracted  (^d,  e,f) 
until  it  forms  a  peduncle  (j),  the  upper  surface,  which  now  bears 
transparent,  but  soft,  rays,  becoming  regularly  circular ;  a  delicate 
hyaline  i)ellicle  then  appears  on  the  circumference  of  the  body.  The 
peduncle  proper  appears  last,  without  any  ajjparent  origin  from  the 
substance  of  the  body,  as  a  narrow  hyaline  disk  at  its  base ;  it  then 
becomes  a  short  non-nucleated  capsule  with  distinct  walls  (g,  h,  k,  I), 
ultimately  elongating  to  assume  its  final  shape. 

Another  form  of  bud  (Fig.  14,  I)  is  observed,  but  less  commonly, 
■  at  the  same  period.  When  first  seen,  it  formed  a  cylindrical  process 
in  the  calyx,  was  finely  granular,  contained  one  or  two  contractile 
vacuoles,  and  bore  a  few  short  rays  (h)  ;  it  then  elongated  itself, 
having  a  basal  strand  of  substance  connecting  it  with  the  adult, 
whose  cuji-like  form  it  takes  ;  it  moves  with  ease  on  its  pedicle  in 
this  position,  but  though  readily  detached,  its  future  history  was  not 
traced. 

Variety  of  Codonosiga  botrytls  Stein  ex  Ehrb.  (Fig.  15).  This 
form  often  has  a  branched  pedicle,  the  secondary  pedicles  starting 
from  the  top  of  the  primary  one  ;  each  carries  an  individual,  and 
their  number  never  exceeds  four,  and,  like  the  top  of  the  chief  one, 
they  are  thicker  than  the  stem.  The  hyaline,  finely  granular  body 
substance  contains  some  special  refracting  granules,  •001- '002  mm. 
broad.  To  a  small  elevation  at  the  anterior  end  are  attached 
four  short,  stiff  cirrhi  (/),  half  the  length  of  the  body,  in  some 
cases  united  by  a  delicate  membrane  so  as  to  form  a  collar  (e).  In 
some  individuals  the  base  of  the  flagellum  (j)  is  surrounded  by  a  short 
cup-shaped  process  (i)  which  may  be  either  homogeneous  or  longitu- 
dinally striated  and  is  alternately  protruded  and  retracted ;  it  has  not 
been  observed  before.  The  flagellum  ends  bluntly.  There  is  no 
shell,  the  body  and  pedicle  dissolving  rapidly  in  ammonia. 


INVERTEBRATA,    CRTPTOGAMIA,    MICROSCOPY,    ETC.  819 

The  variety  has  probably  been  already  figured  by  Fromentel  and 
Jobard-Muteau  as  Pijcnohnjon,  and  described  by  Bory  de  Saint  Vincent 
as  Autojjhi/sa.  These  Flagellata  are  clearly  distinct  from  the  Vorti- 
oellina.  The  cirrhi  are  homologous  with  the  collar,  for  the  two  organs 
replace  each  other. 

Radiolaria  in  "Diaspro."* — Prof.  Dante  Pantanelli  announces 
the  discovery  of  Eadiolaria  in  the  Italian  "  diaspro  "  from  various 
places,  and  of  difierent  ages ;  two  from  the  lias,  and  one  probably 
cretaceous,  but  the  greater  number  were  from  the  upper  eocene. 
Professor  de  Stefani,  in  speaking  of  this  diaspro  and  manganito  at  a 
previous  meeting  of  the  Pisa  Society,  attributed  their  formation  to 
deposits  in  deep  seas ;  but  this  idea  was  combated,  and  in  couseciuence 
Professor  Pantanelli  undertook  the  examination,  with  the  above  results. 
The  importance  of  this  is  much  increased  by  the  fact  that  the  diaspro 
of  Murio  and  Crevole  are  intercalated  with  the  serpentine,  and  it 
may  be  hoped  that  much  light  will  thus  be  definitely  thrown  on  a 
question  which  is  occujjying  nmch  attention  in  Italy,  and  has  also 
been  taken  up  by  some  of  our  leading  English  geologists — the  forma- 
tion of  the  Italian  serpentines.  Professor  Pantanelli  thinks  we  may 
now  definitely  accept  the  hypothesis  of  Stoppani,  that  the  serpentines 
are  volcanic  rocks,  for  the  most  part  erupted  in  deep  seas.  Thus  the 
same  conclusion  is  arrived  at  from  quite  difierent  standpoints.  He 
also  thinks  it  may  facilitate  an  explanation  of  the  mode  of  formation 
of  manganese  deposits,  as  they  occur  in  connection  with  the  diaspro 
rich  in  fossils,  and  hints  that  it  would  make  us  doubt  the  possibility 
of  their  being  formed  by  an  endogenous  action,  or  from  deposits  of 
mineral  water. 

Professor  de  Stefani  called  attention  to  the  use  the  Microscope  may 
now  be  to  anthropologists,  in  showing  from  what  locality  implements 
made  of  this  rock  were  derived. 

Mr.  A.  W.  Waters  believes  he  is  in  a  position  to  refer  to  the 
Eocene  "  diaspro "  the  rock  mentioned  by  Professor  Bonney,f  in 
which  attention  was  called  to  its  containing  fossils  which  Professor 
Bonney  was  himself  inclined  to  refer  to  Eadiolaria  and  Bryozoa. 
Professor  Pantanelli  lias  in  the  press  an  article  describing  a  large 
number  of  the  Eadiolaria  observed. 


BOTANY. 

A.    GENERAL,  including  Embryology  and  Histology 
of  the  Phanerogamia. 

Development  of  the  Embryo-sac.:}:— Dr.  A.  Fischer  publishes  the 
results  of  a  largo  scries  of  observations  on  tho  development  of  the 
embryo-sac,  especially  in  monocotyledons  and  in  diulypctalous  dicoty- 
ledons. Tlie  following  are  the  more  important  of  the  conclusions  at 
which  ho  has  arrived. 

»  '  Boll.  U.  Com.  Gcol.  d'ltal.,'  1880,  Nod.  1,  2.  Sco  '  Geol.  Mag  ,'  vii.  (1880) 
p.  317. 

t  '(ieol.  Mng.,'  vi.  (1870)  p.  3(;0. 

t  '  Jonaisohi'  Zoitsolir.  f.  Naturwis^a.,'  .\iv.  (1880)  p.  90. 

8    H    2 


8'20  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

The  three  nuclei  in  the  chalazal  end  of  the  embryo-sac  around 
which  the  antipodals  are  subsequently  formed,  are  termed  by  Fischer 
the  antipodal  nuclei;  the  fourth  nucleus  is  called  the  loicer  polar 
nucleus;  the  two  sister  nuclei  in  the  upper  end  of  the  embryo-sac 
which  are  taken  up  into  the  synergidse,  are  denominated  synerg- 
nuclei ;  the  two  others,  the  germinal  nucleus  and  the  lower  polar 
nucleus,  according  as  they  subsequently  form  the  embryo  or  unite 
with  the  lower  polar  nucleus  ;  the  product  of  this  union  may  be  called 
the  central  nucleus  of  the  embryo-sac. 

In  monocotyledons  a  very  great  uniformity  was  observed  in  the 
development  of  the  groups  of  cells  in  the  end  of  the  embryo-sac,  and  in 
the  origin  of  the  central  nucleus.  The  cells  of  the  germinal  apparatus 
are  always  formed  in  threes,  and  never  multiply.  Two  synergidse  are 
always  produced,  the  nuclei  of  which  stand  to  one  another  as  sister- 
cells,  in  the  same  relation  as  the  germinal  nucleus  to  the  upper  polar 
nucleus.  The  two  synergida3  are  usually  inserted  at  the  apex,  with 
exceptions  in  the  cases  of  Sesleria  and  Allium  fistulosum.  The  mode 
of  attachment  of  the  germinal  nucleus  is  subject  to  greater  variations. 
Thus  we  find  it  inserted  into  the  wall  of  the  embryo-sac  beneath  the 
synergidfe,  apparently  attached  to  them,  in  Luzula,  TriglocJiin,  Carex, 
Alisma,  Elodea,  and  Nothoscordum.  In  Alopecurus,  Melica,  Orchis, 
Gymnadenia,  Ornithogalum,  Gladiolus,  Crocus  vermis,  and  FunJcia,  the 
germinal  nucleus  is  attached  to  the  apex  of  the  embryo-sac  in  the 
same  way  as  the  synergidfe,  so  that  it  appears  to  be  covered  by  them, 
or  to  lie  upon  them,  according  to  the  side  from  which  the  observation 
is  made.  Si^ecial  interest  is  attached  to  the  arrangements  in  Sesleria 
and  Allium  fistulosum,  with  which  Ehrharta  agrees  in  some  respects. 

The  antipodals  always  originate  in  threes.  They  have  but  a 
transitory  existence  in  Alisma,  TriglocJiin,  Orcliis,  and  a  majority  of 
the  monocotyledons  examined.  Those  of  the  Graminefe  are  dis- 
tinguished by  the  extent  to  which  they  divide,  and  by  their 
comparatively  late  resorption. 

The  union  of  the  two  polar  nuclei  takes  place  in  two  ways.  In 
one  case  the  two  nuclei  approach  one  another,  and  the  coalescence 
takes  place  in  the  centre  of  the  embryo-sac ;  in  the  other  case  the 
uj)per  of  the  two  remains  stationary,  and  the  lower  one  passes  com- 
pletely across  the  embryo-sac.  The  former  occurs  in  Luzula,  Alisma, 
Carex,  TriglocJiin,  OrcJiis,  OrnitJiogalum,  and  Nothoscordum  ;  the  latter 
in  Elodea,  Graminefe,  and  Allium  fistulosum.  The  coalescence  usually 
takes  place  before  impregnation  ;  but  in  Alisma  and  Allium  fistulosum 
only  during  the  contact  of  the  pollen-tube,  or  even  after  impregnation 
has  been  completely  effected. 

The  formation  of  "  tapeten-cells  "  was  observed  only  in  Luzula 
and  TriglocJiin.  The  mother-cell  springs  from  the  subepidermal 
layer  in  Elodea,  Alisma,  TriglocJiin,  Luzula,  and  Graminea3 ;  in  Carex 
from  a  deeper  layer  of  the  nucellus.  In  Alisma  and  Allium  fistulosum 
the  activity  of  the  mother-cell  is  exhausted  in  the  formation  of 
primary  daughter-cells.  In  Gymnadenia,  OrcJiis,  and  AntJiericum 
three  cells  are  formed  by  further  division  of  the  lower  of  these 
daughter-cells ;    while  four  secondary  daughter-cells  are  developed 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  821 

from  the  mother-cell  in  Gramineje,  Elodea,  TriglocMn,  Carex,  Luztila, 
Tritonia,  Sisyrinchiuin,  aucl  Hemerocallis. 

The  walls  which  separate  the  daughter-cells,  especially  that  which 
is  formed  first,  are  marked  by  a  strong  power  of  swelling.  In  all 
cases  the  lowest  daughter-cell  shows  considerable  increase  in  size  at 
an  early  jieriod.  It  is  this  only  which  always  develojis  into  the 
embryo-sac.  Two  sacs  in  a  single  ovule  were  once  observed  in 
Trujlochin. 

In  the  dialypetalai,  as  in  monocotyledons,  the  mode  of  formation  of 
the  cells  in  the  embryo-sac  is  remarkably  constant.  The  insertion  of 
the  two  synergidsB  in  its  apex  exhibits  no  variation  in  any  species 
examined. 

In  auatropous  ovules  the  germinal  nucleus  appears  as  if  fixed  to 
the  syuergidic,  but  is  in  fact  inserted  somewhat  lower  down  on  the 
wall  of  the  embryo-sac,  and  is  partly  covered  by  the  synergida).  The 
only  exception  observed  was  in  Hippuris,  where  the  position  of  the 
germinal  nucleus  was  always  lateral. 

The  same  regularity  recurs  in  the  synergidte  always  appearing  in 
pairs,  and  in  the  presence  of  a  single  germinal  nucleus ;  the  only 
instances  in  which  two  germinal  nuclei  were  observed  are  Gomphrena 
and  Santalum  album. 

A  reduction  in  number  of  the  synergidte  to  one  occurs  occasionally 
as  an  abnormality.  The  antii)odals  are  always  formed  in  threes  ;  in 
only  a  single  case  was  a  greater  number  observed,  or  of  their  nuclei. 
They  attain  a  very  j)Owerful  development  in  Delphinium  and  Allionia  ; 
but  are  transitory  and  fully  developed  in  Chenopodium,  Helianthemum, 
and  Hippuris. 

The  central  nucleus  is  always  formed  by  coalescence  of  the  two 
polar  nuclei.  Of  these  either  both  are  motile,  meeting  in  the  centre 
of  the  embryo-sac,  or  the  upper  one  remains  stationary,  and  awaits 
the  approach  of  the  lower  one.  The  former  occurs  in  Delpliiuimn, 
Myosurus,  Rihes,  Ci/doiiia,  Geum,  and  Ruhus ;  the  latter  in  the  Centro- 
sperma),  Uelianthemuia,  Hippuris,  Sanijuisorha,  and  Agrimouia. 

The  mother-cell  of  the  embi'yo-sac  always  originates,  in  dialypetala), 
from  the  sube2)idcrmal  layer,  which  attains  in  tliis  class  its  greatest 
dill'erentiation  ;  and  a  resemblance  is  thus  exhibited,  through  Hippuris, 
to  the  behaviour  in  tlie  gamopetalne.  Tapeten-cells  arc  nut  always 
given  off;  but  a  uniform  behaviour  is  often  to  be  observed  in  large 
circles  of  aftinity,  as  in  the  Centrosperuue.  In  Chenopodium  the 
division  of  these  cells  takes  considerable  part  in  the  structure  of  the 
uucellus. 

Tlie  epidermis  remains  single  in  a  great  number  of  cases ;  although 
a  periclinal  increase  of  its  elements  occurs  frequently.  The  divisions 
are  still  more  copious  -in  Delphinium,  Helianthemum,  and  Rosacea), 
where  tliey  assist  the  growth  of  tlie  apex  of  the  nucellus.  Hippuris 
exhibited  a  peculiar  behaviour  of  the  epidermis,  resembling  that  in 
the  ganiopetahe. 

As  a  rule,  only  a  single  embryo-sac  mother-cell  is  formed,  as  in 
Centrospcrmi\i,  Rannnculacea",  and  ltibe»,  though  a  doubling  takes 
place  occasionally.     In    Helianthemum  and  Kosaccio  several   niothcr- 


822  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

cells  are  produced  regularly,  with  originally  equal  power  of  develop- 
ment, until  one  of  them,  usually  the  central  one,  attains  the  upper 
hand,  so  that  finally  only  a  single  embryo-sac  is  produced. 

In  Chenopodium  and  Sabulina  only  primary  daughter-cells  proceed 
from  the  mother-cell.  By  division  of  the  lower  of  these  a  row  of 
tlireo  cells  is  produced  in  AUionia,  Goinphrena,  Cydonia,  Geum,  and 
Mi/osurus,  exceptionally  in  Chenopodium.  Four  secondary  daughter- 
colls  api^ear  in  Delphinium,  Itibes,  Helianthermim  (in  this  case  as 
many  as  six),  Sanguisorha,  Huhus,  Polygonum,  and  Hippuris.  In 
dialypctalte  it  is  always  the  lowest  cell  of  the  row  of  daughter-cells, 
whatever  their  number,  and  this  only,  which  develops  into  the 
embryo-sac ;  the  only  exception  at  present  known  occurring  in  B,osa 
livida. 

Fertilization  of  Cohsea  penduliflora.* — Mr.  A.  Ernst,  writing 
from  Caracas,  describes  his  observations  showing  the  peculiar  circum- 
stances under  which  the  flowers  of  this  plant  are  fertilized. 

The  flowers  have  little  to  attract  attention,,  being  dull  green  in 
colour,  with  very  little  red  on  the  filaments,  and  no  smell.  The 
plant  climbs  in  the  same  manner  as  C.  scundens,  described  in  Darwin's 
'  Climbing  Plants.'  The  flowers  grow  on  long  peduncles,  which  gene- 
rally have  a  horizontal  position,  projecting  some  five  or  six  inches  from 
the  mass  of  the  foliage.  When  the  calyx  opens,  the  filaments  as  well  as 
the  style  are  irregularly  twisted ;  but  in  about  two  or  three  days  all 
become  straight.  The  style  hangs  obliquely  downwards  ;  the  fila- 
ments all  bend  sideways,  the  bend  being  inside  the  tube  of  the 
corolla,  a  little  over  the  hairs  at  their  base.  There  is  often  a  distance 
of  15  cm.  between  the  anthers  of  either  side.  About  5  or  6  p.m. 
the  anthers  burst,  and  soon  after  the  style  rises  and  assumes 
a  central  position,  so  that  there  is  a  distance  of  about  10  cm. 
between  the  stigmas  and  any  of  the  anthers.  Only  then  is  nectar 
being  secreted  (very  copiously)  by  the  glandular  disk  round  the  base 
of  the  ovary,  and  it  appears  therefore  when  the  anthers  have  done 
their  work ;  even  an  hour  before  their  rupture  no  trace  of  it  is  to  be 
found.  The  nectar-cavity  in  the  tube  of  the  corolla  is  completely 
shut  up  by  the  numerous  spreading  hairs  at  the  base  of  the  filaments, 
so  that  an  overflow  is  impossible.  The  grains  of  pollen  are  very 
large  (0  •  2  mm.  in  diameter)  and  of  the  same  structure  as  in  Cobcea 
scandens 

Several  weeks  passed  at  first  before  the  manner  of  fertilization 
was  witnessed.  The  stigmas  were  every  morning  carefully  examined, 
but  no  pollen  could  be  discovered  on  them.  The  filaments  twisted 
back  again  and  got  somewhat  frizzled,  after  one  single  night's 
expansion.  About  noon  the  corolla  drops  off,  separating  from  close  to 
the  glandular  ring,  and  then  slipping  down  over  the  style,  which,  by 
this  time,  is  again  in  a  relaxed  hanging  position.  There  is  always 
some  nectar  in  the  tube  of  the  corolla  after  its  separation,  but  none 
remains  in  the  calyx  round  the  ovary,  nor  does  its  secretion 
continue. 

*  '  Nature,'  xxii.  (1880)  p.  148. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  823 

This  shows  that  the  fertilization  must  take  place  in  the  same 
night  after  the  bursting  of  the  anthers,  and  it  was  but  natural  to 
suppose  that  it  was  clfccted  by  nocturnal  moths.  It  would  appear, 
furthermore,  that  the  nectar  is  not  of  any  direct  advantage  to  the 
plant,  as  M.  G.  Bonnier  emphatically  affirms,*  because  of  its  being 
jjroduced  and  lost  in  all  flowers,  fertilized  or  not,  in  the  same  way. 

As  soon  as  the  number  of  flowers  increased  (on  some  evenings 
twenty  to  twenty-five  had  their  anthers  openedj,  most  of  them  were 
found  every  morning  with  pollen  on  the  stigmas ;  and  keeping  a  close 
watch,  it  was  discovered  that  the  plant  was  visited  by  several  largo 
Sphingidse  belonging  to  the  genera  Chcerocampa,  Diludia,  and 
Amplionyx.  All  of  them  proceeded  in  the  same  manner.  Holding 
the  body  close  over  the  style,  they  dipped  their  spiral  tongues  into 
the  tube  of  the  corolla,  beating  all  the  while  the  anthers  so  violently 
with  the  tijjs  of  their  fore-wings  that  they  dangled  about  with  great 
velocity  in  every  direction.  The  grains  of  pollen  being  covered  by  a 
sticky  substance,  many  of  them  adhered  to  the- wings.  An  Amplionyx, 
after  having  visited  six  flowers  consecutively,  had  the  tijis  of  the  fore- 
wings  almost  yellow  with  pollen.  When  leaving  a  flower  for  another 
one,  some  of  this  pollen  is  even  lost  on  the  foliage,  but  by  the  time 
the  insect  takes  its  central  position  before  the  flower  the  stigmas  are 
likewise  touched  by  the  wings,  and  thus  some  pollen  is  left  on  them. 
Some  flowers  remain  without  being  fertilized,  especially  in  places 
where  the  moths  cannot  reacli  them  easily.  All  flowers  fertilized  in 
this  manner  set  fruit  very  soon ;  but  no  flower  gave  a  fruit  without 
having  its  stigmas  jiollinized  by  crossing. 

Self-fertilization  is  therefore  excluded,  and  this  is  further  proved 
by  the  following  exjieriments : — Twelve  flowers  were  artificially 
fertilized  by  their  own  pollen  and  afterwards  protected  by  muslin 
bags ;  only  in  one  case  was  a  fruit  obtained ;  but  it  is  doubtful 
whether  some  foreign  pollen  did  not  reach  the  stigmas  of  tbis 
flower.  Cross-fertilization  was  likewise  tried  in  twelve  flowers,  nine 
being  experimented  on  in  the  same  evening  after  the  opening  of 
the  anthers,  and  three  the  next  morning.  All  the  former  arc  now 
with  fruit ;  the  latter  remained  sterile.  This  fact  shows  how  very 
short  is  the  jieriod  of  possible  fertilization. 

Flowers  visit'  d  by  nocturnal  moths  are  as  a  rule  cither  large  and 
of  white  colour, -or  have  a  strong  smell ;  but  in  this  Cohcca  the  former 
is  certainly  not  the  case,  and  no  smell  could  bo  discovered.  But  it  is 
well  known  that  insects,  especially  Lepidoptera,  have  in  this  respect 
a  really  .wonderful  keenness,  which  enables  them  to  track  a  scent 
absolutely  impercei)tible  to  man. 

Structure  and  Motile  Properties  of  Protoplasm. t — According 
to  C.  Frommann,  tlie  protoplasm  of  tlie  vegetable  cell,  whirh  often 
apjjcars  quite  homogeneous,  has  a  I'cticulate  structure,  as  also  have 
the  chlorophyll-grains.     Tliis  structure  was  seen  cspocially  clearly  in 

*  '  Ann.  Sci.  Nut.  But.,'  viii.  (ISTD)  p.  20G. 

t  'IJiob.  lib.  Stru'-tiir  u.  Buwc^^mi'^-urscheinunj^on  (Kh  rrotoplnMn  dor 
ril:iii/ciizcllc,' vou  C.  FicMuiiKimi,  Jliiu,  1.S80.      See  'Dot.   Ctulrulbl.,' i.  (ISSU) 


82  t  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

the  epidermal  cells  of  Bhododendron  ponticum  and  Draccena  Draco. 
The  cells  are  usually  not  entirely  filled  with  protoplasm  ;  roundish 
lumps  or  striated  Liyers  mostly  lie  near  the  cell-wall.  In  the  mass 
lie  larger  granules,  and  these  form  the  knots  which  are  connected 
with  one  another  by  nets  of  fine  threads  with  very  narrow  round, 
oval,  or  angular  masses.  This  reticulate  structure  of  the  protoplasm 
varies  in  form  and  distinct-ness. 

The  cell-wall  also  exhibits  a  filamentous  structure  ;  the  reticula- 
tions appear  gradually  to  pass  over  into  the  substance  of  the  cell-wall. 
Two  adjoining  cells  usually  communicate  with  one  another  by  means 
of  cavities  and  crevices  which  are  traversed  by  granules  and  threads ; 
so  that  the  cells  are  thus  closely  connected  together  by  the  uniting 
threads  of  protoplasm.  The  contents  of  the  canals  are  often  to  be 
clearly  made  out,  but  are  often  scarcely  to  be  distinguished  from  the 
cell-wall,  since  they  may  gradually  acquire  the  same  refractive  jiower 
as  the  cell-wall.  Chlorophyll-grains  and  coloured  portions  of  the 
reticulations  are  also  found,  not  only  in  the  cavities  of  the  division- 
walls,  but  even  in  their  substance.  The  cuticle  of  the  cells  is  also 
not  homogeneous,  but  exhibits  reticulate  and  granular  deposits.  The 
same  is  also  the  case  with  the  hypodermal  cells  ;  but  among  their 
contents  are  found  also  small  roundish  granules  with  a  reticulate 
structure.  A  similar  structure  was  manifested  by  Aloe  arhorescens, 
Crocus,  Hyacinthus,  and  Mentha. 

The  origin  of  the  reticulate  from  homogeneous  protoplasm  can 
be  readily  followed  out  in  the  aleurone  grains  in  swollen  seeds  of 
Lupinus  FarJceri ;  within  the  same  cell  the  transition  takes  j)lace 
from  homogeneous  aleurone  grains  to  grains  with  a  scarcely  per- 
ceptible, and  then  to  those  with  an  evident  reticulation.  The 
behaviour  of  the  threads  of  the  network  when  starch-grains  are 
being  developed  can  be  investigated  in  the  chloroi^hyll-grains  of  Aloe. 
In  the  skeleton  of  the  network  lie  separate  roundish  bodies,  which 
are  coloured  blue  by  iodine  ;  while  in  other  chlorophyll-grains  the 
threads  of  the  network  are  themselves  coloured  blue  by  iodine, 
showing  that  their  substance  is  gradually  transformed  into  starch. 

Structure  of  Sieve-tubes.* — Previous  investigations  of  the  struc- 
ture and  development  of  sieve-tubes  have  been  carried  out  only  in  the 
cases  of  Pinus  sylvestris  and  P.  Laricio,  which  agree  in  every  detail. 
E.  Janczewski  has  now  extended  his  observations  to  other  ConiferaB, 
as  also  to  the  Gnetacero  and  Cycadefe. 

The  bast  of  gymnosperms  always  contains  numerous  sieve-tubes 
of  uniform  shape ;  they  are  jjrismatic,  their  terminal  walls  being 
strongly  oblique.  The  tangential  walls  of  the  sieve-tubes  are  per- 
fectly smooth,  but  the  radial  walls  are  provided  with  more  or  less 
thick,  the  terminal  walls  with  especially  thick,  sieve-plates.  These 
sieve-plates  have  a  roundish  form  and  sharp  boundaries,  when  the 
cell-wall  of  the  sieve-tube  is  sufficiently  thick  and  passes  suddenly 
into  the  sieve-plate,  as  in  Pinus  and  Abies.     When,  on  the  contrary, 

*  '  SB.  k.  Akad.  Wiss.  Krakau,  Matb.-naturw.  Sect.,'  vii.  (1880)  p.  29.     See 
'  Bot.  Centralbl.,'  i.  (1880)  p.  485. 


mVERTEBEATA,    CBYPTOGAMIA,    MICROSCOPY^    ETC.  825 

the  cell-wall  is  much  thinner,  not  varying  greatly  in  thickness  from 
the  sieve-plate  itself,  the  transition  into  the  sieve-plate  is  more 
gradual,  the  boundaries  of  the  latter  being  less  striking  to  the  eye, 
and  the  form  of  the  sieve-plate  is  altered,  being  divided  by  stri83  of 
the  cell-wall  into  smaller  plates  more  or  less  separated  from  one 
another,  as  in  Ginrjko,  Gnetum,  Ephedra,  and  Cycas.  Mature  sieve- 
plates  contain  no  jn-otoplasm  in  their  interior,  and  are  not  subject  to 
any  changes  from  the  season.  Their  pores  are  always  uncovered,  and, 
as  in  angiosperms,  comiiletely  perforated. 

The  sieve-i^lates  arise  from  the  membrane  of  the  bordered  pits 
which  are  in  the  cambial  cells  on  their  radial  and  terminal  walls. 
The  membrane  of  these  bordered  pits  swells  up,  is  considerably 
altered  in  structure  and  in  chemical  composition,  and  finally  forms 
on  both  sides  a  thick  callus,  within  which  is  the  sieve-plate,  which 
is  exposed  by  the  absorption  of  the  callus. 

Since  the  protoplasm  disapj)ears  from  the  sieve-tubes  immediately 
after  they  are  set  free,  nothing  can  at  present  be  satisfactorily  deter- 
mined respecting  their  physiological  purpose  and  the  period  of  their 
activity. 

The  sieve-tubes  of  gymnosperms  are  therefore  homologous  to 
those  of  angiosperms,  but  differ  from  the  latter,  both  in  the  mode 
of  development  of  their  sieve-plates,  in  the  absence  of  protoplasm 
from  them  when  mature,  and  also  in  the  constancy  in  form  of  the 
sieve-plates  at  all  periods  of  the  year. 

Chemical  Composition  of  Chlorophyll.* — E.  Sacchse,  of  Leipzig, 
publishes  some  fresh  results  of  phyto-chcmical  investigations  on  the 
composition  of  chlorophyll.  By  means  of  a  peculiar  method  he  has 
succeeded  in  separating  both  the  green  and  the  yellow  pigment  from 
the  beuziu-extracts  of  leaves,  in  Allium  ursinum  and  Primula  elatior, 
in  a  pure  state,  though  perhaps  not  altogether  unchanged  from  the 
chlorophyll  in  a  functional  condition. 

Contrary  to  expectation  the  green  pigment  was  found  not  to  be 
homogeneous,  but  capable  of  separation  into  five  distinct  chemical 
substances,  resembling  one  another  closely  in  optical  properties,  but 
varying  in  quantitative  composition.  The  proportion  of  carbon  varies 
between  about  66  and  72  per  cent.,  that  of  nitrogen  between  about 
3  and  5  •  5  per  cent. 

Similar  results  were  obtained  with  the  yellow  pigment.  In  this 
also  were  found  at  least  four  distinct  chemical  substances,  varying  in 
colour  from  yellow  to  reddish  brown,  of  a  similar  fatty  nature,  and 
similar  spectroscopic  proi)crties,  but  varying  in  chemical  composition. 
They  are  all  non-nitrogenous,  while  the  proportion  of  carbon  varies 
between  about  66  and  71  per  cent.  Each  of  the  green  pigments  has 
a  corresponding  yellow  "pigment  with  the  same  carbon-percentage,  but 
destitute  of  nitrogen. 

In  addition  to  the  green  and  yellow  pigments  there  was  found  a 
remarkable  substance,  agreeing  nearly  with   starch   in   its   carbon- 

*  '  Phytoclicm.  UnUr.siicli.  iRraiisj^.  v.  R.  Sacchse,'  i.  (ISSO)  p.  ].  iSco '  Bot. 
Ccntralbl.,'  i.  (IbSO)  p.  5J'J. 


82 1)  RECORD    OF    CURRENT    RESEARCHES   RELATING   TO 

percentage,  but  distiuguislaed  by  containing  a  considerably  greater 
quantity  of  water,  and  only  partially  converted  into  sugar  by  the 
action  of  acids.  Tbe  author  has  not  been  able  to  determine  whether 
this  is  an  accidental  accompaniment  to  the  pigments,  or  what  is  its 
relation  to  chlorophyll. 

Composition  of  Chlorophyll.* — Hoppe-Seylcr  publishes  a  con- 
tinuation of  his  work  on  chlorophyllan,"]-  a  crystalline  substance 
closely  resembling  chloroj)hyll,  obtained  from  green  grass.  By 
treatment  with  alcoholic  potash,  chlorophyllan  yields,  amongst  other 
l)roducts,  an  acid  characterized  by  giving  a  splendid  purple-coloured 
ethereal  solution,  which  exhibits  very  marked  rose-red  fluorescence. 
For  this  compound — C^oB^siOs — Hoppe-Seyler  proposes  the  name  of 
dichromatic  acid.  The  absorption  spectrum  of  the  acid  in  ethereal 
solution  is  marked  by  two  bands  between  C  and  D,  whilst  the 
spectrum  of  the  fluorescent  light  from  the  same  solution  exhibits  two 
bright  bands  in  exactly  the  same  positions. 

Division  of  Chlorophyll-grains.;]: — J.  Schaarschmidt  summarizes 
the  observations  of  recent  writers  on  the  division  of  chlorophyll, 
adding  some  also  of  his  own.  He  states  the  general  results  obtained 
to  be  that  the  chlorophyll-grain  is  capable  of  division  in  all  plants ; 
that  the  division  is  not  efiected  at  any  particular  time  of  the  year ; 
and  that  it  takes  place  in  the  same  manner  as  the  cell-nucleus,  in  two 
ways ;  most  usually  by  a  median  zone  and  the  formation  of  numerous 
threads  of  protoplasm ;  or  by  the  formation  simply  of  numerous 
threads  of  protoplasm,  in  which  case  no  formation  of  a  median  zone 
takes  place. 

The  author  enumerates  22  species  of  cryptogams,  and  38  of 
phanerogams,  in  which  the  division  has  been  observed  either  by 
himself  or  others.  He  claims  to  have  observed  that  the  surface  of 
the  chlorophyll-grains  is  furnished  with  extremely  fine  cilia  which 
are  usually  placed  at  equal  distances  apart,  and  are  colourless.  They 
were  first  observed  in  Boehmeria  biloha,  most  distinctly  in  Hartwegia 
comosa. 

Branching  of  Endogenous  Organs  from  the  Mother-organ- §— 
An  elaborate  paper  on  this  subject  by  H.  Vouhone  concludes  with  the 
following  summary  of  results  : — 

1.  From  the  young  root  a  secretion  is  given  off  which  acts  as 
a  solvent  on  the  tissue  of  the  mother-organ,  destrc^ying  first  the 
turgidity  of  the  cells,  and  then  their  primordial  utricle,  and  thus 
making  way  for  the  root. 

2.  When  the  secretion  cannot  act  in  consequence  of  the  nature  of 
the  cell-wall,  the  quickly  growing  root  exercises  a  mechanical  pressure 
on  the  obstructive  tissue.  In  this  resj)ect  there  is  a  difference  in  the 
behaviour  of  different  kinds  of  tissue. 

*  '  Zeitschr.  physiol.  Cliemie.'     See  '  Nature,'  xxii.  (18S0)  p.  279. 
t  See  this  Jourual,  ante,  pp.  IIG  and  2!)6. 

X  '  Magyar  Nuve'nytani  Lapok,'  iv.  (1880)  p.  33.  See  '  But.  Centralbl.,'  i. 
(1880)  p.  457. 

§  '  Flora,'  Ixiii.  (1880)  p.  227. 


INVERTEBRATA,    CRYPTOQAMIA,   MICROSCOPY,    ETC.  827 

a.  Tliick-wallcd  parenchyma  and  bast  are  simply  stretched,  and 
then  ruptured. 

h.  The  epidermis  and  collenchymatous  cells  continue  to  grow 
for  a  time  together  with  the  root,  and  are  only  subse- 
quently overtaken  and  broken  through  by  it. 

3.  In  consequence  of  the  increase  in  thickness,  a  union  in  growth 
takes  place  between  the  root  and  the  adjoining  tissue  of  the  mother- 
organ,  when  the  latter  is  still  in  a  formative  condition. 

4.  The  subsequent  increase  in  length  of  the  cells  of  the  root 
causes  also  the  innermost  cortical  cells  of  the  mother-organ,  which 
are  in  anatomical  connection  with  the  root,  to  become  stretched 
radially.  At  the  same  time  the  true  increase  in  thickness  causes  the 
cortical  cells  to  form  curves  parallel  to  the  surface  of  the  root.  In 
consequence  of  the  similarity  of  the  cells  which  form  the  curves, 
curves  crossing  each  other  at  right  angles  are  also  seen ;  and  hence 
the  root  appears  to  run  out  from  a  broad  base,  while  in  fact  it  is 
considerably  contracted  below. 

Influence  of  Direction  and  Strength  of  Illumination  on  certain 
Motile  Phenomena  in  Plants.* — E.  Stahl's  paper  on  this  subject 
contains  the  following  general  observations  : — 

The  effects  of  light  in  this  respect  are  very  various.  Sometimes 
formed  cell-contents,  as  chlorophyll-grains,  in  the  interior  of  the 
protoplasm,  are  set  in  motion,  and  carried  within  the  cell-cavity 
to  places  which  indicate  a  definite  relation  to  the  direction  of  the 
rays  of  light.  In  other  cases  the  influence  of  the  light  is  exhibited, 
not  in  the  direction  of  certain  particles,  but  of  entire  free  motile 
organs. 

In  spite  of  differences  in  particular  cases,  a  general  and  important 
phenomenon  is  evident,  that,  when  other  conditions  are  the  same, 
csijecially  where  the  direction  of  the  light  remains  the  same,  the 
variations  in  sensitiveness  to  light  depend  entirely  on  the  intensity  of 
the  light. 

When  the  direction  remains  the  same,  the  chlorophyll-plate  of 
Mcsocarpus  places  itself  at  right  angles  to  this  direction  when  the 
illumination  is  weak ;  but,  when  the  intensity  passes  a  certain  limit, 
the  plate  turns  througli  an  angle  of  90^,  and  places  itself  in  the 
direction  of  the  rays.  A  swarnispore  usually  turns  its  anterior  end 
to  weaker  light,  the  reverse  when  the  light  is  stronger.  This  is  true 
both  in  the  case  of  jiositively  heliotropic  filaments  and  of  those  which 
grow  at  right  angles  to  the  direction  of  the  light.  The  behaviour  of 
species  of  Chisterium  varies  with  the  intensity  of  the  light ;  and  the 
same  is  true  for  diatoms,  and,  according  to  older  observations,  for 
Oscillatorie;e  and  Myxomycetes. 

The  varying  susceptibility  of  vegetable  protoplasm  to  the  influence 
of  light,  whicli  has  tliiis  been  determined  in  a  number  of  single  cases, 
is  of  j)r()portionate  inq»ortance  in  determining  the  positions  dependent 
on  light  of  more  complicated  organs,  as  is  illustrated  in  the  case  of 
Vauchcria.     Whoa  a  filament  of  Vancheria  is  illuminated  from  one 

•  '13ot.  Zeit.,'  xxxviii.  (1880)  p.  2'J7. 


828  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

side,  it  assumes  a  direction  of  growth  at  riglit  angles  to  the  liglit,  so 
long  as  tlie  illumination  is  of  a  certain  intensity.  If,  other  conditions 
remaining  the  same,  the  distance  of  the  plant  from  the  source  of  light 
is  increased,  an  intensity  is  sooner  or  later  attained  at  which  the 
filament  alters  its  direction  of  growth,  and  becomes  positively 
heliotropic  ;  it  grows  more  or  less  exactly  towards  the  light.  If  the 
earlier  condition  is  restored,  the  plant  assumes  again  its  previous 
direction.  This  is  true  both  of  positively  heliotropic  filaments  and  of 
those  which  grow  at  right  angles  to  the  direction  of  the  light.  The 
phenomena  different  from  this  exhibited  by  a  plant  of  Vaucheria 
rooting  in  the  ground  are  no  doubt  due  to  similar  causes ;  but  the 
conditions  have  not  been  sufiiciently  investigated. 

Case  of  Apparent  Insectivorism.*  —  Professor  Baillon,  at  a 
recent  meeting  of  the  Linnean  Society  of  Paris,  read  the  following 
notes : — 

Peperomia  arifolia  Miq.,  of  which  the  variety  arcjyreia  is  culti- 
vated in  so  many  greenhouses,  has  the  leaves  more  or  less  deeply 
peltate.  I  have  seen  stalks  on  which  the  peltation  on  certain  leaves 
was  so  exaggerated  as  to  show  on  a  cross-section  a  depth  of  nearly 
4  cm.  When  the  concave  stalks  take  a  suitable  direction,  water, 
principally  that  from  sprinkling,  would  accumulate  and  rest  in  these 
receptacles,  so  well  prepared  to  preserve  it.  Many  small  insects 
would  fall  into  the  water  and  be  drowned.  Last  year,  when  the 
season  v/as  warm,  and  when  the  windows  of  the  house  w^ere  often 
open,  the  number  of  insects  was  very  considerable,  and  these,  soaking 
in  the  water,  gradually  fell  into  decay,  and  it  was  remarkable  that 
there  was  during  this  not  the  least  sign  of  any  putrescent  odour. 
Those  who  believe  in  the  doctrine  of  insect-eating  plants  may 
perhaps  in  this  be  led  to  find  an  argument  favourable  to  such  theories. 
They  will  add  that  the  variety  of  colours  so  strikingly  seen  in  these 
leaves  constitutes  the  agent  of  attraction  for  the  insects  to  come  and 
be  devoured. 

Three  reflections,  each  of  a  different  sort,  here  present  them- 
selves : — 1.  Is  it  not  remarkable  that  the  exaggerated  peltation  of  these 
leaves  is  in  this  case  accompanied  by  an  apparent  insectivorism,  and 
that  the  leaves  of  the  plants  known  up  to  this  time  by  botanists  as 
carnivorous,  owe  their  sac-like  or  horn-like  forms  only  to  an  excessive 
peltation  of  their  limb,  as  was  demonstrated  in  the  evolution  of  the 
leaves  in  Sarracenia  ?  f  2.  How  can  it  be  considered  as  a  proof  of 
insectivorism,  that  plants  like  TJtricidaria  grow  better  in  a  fluid 
containing  albuminoid  compounds,  when  other  plants  grow  equally 
favourably  in  the  same  kind  of  fluid,  which  latter  are  never  for  a 
moment  thought  to  be  carnivorous  ?  3.  How  do  the  chief  priests 
of  our  science  reconcile  the  two  ideas,  that  the  surface  of  the  leaves 
of  plants  is  unable  to  absorb  pure  water  in  contact  with  them,  and 
that  the  same  surface  daily  absorbs  water  charged  with  albuminoid 
substances  and  the  like  ? 

*  'Nature,'  xxii.  (1880)  p.  277.  t  '  Comptes  Eendus,'  Ixxi.  p.  630. 


INVERTEBRATA,    ORYPTOGAMIA,   MICROSCOPY,    ETC.  829 

B.    ORYPTOGAMIA. 

Cryptogamia  Vascularia. 

Prothallia  of  Ferns.* — Professor  J.  Sachs  publishes,  in  the  form 
of  a  supplement  to  the  '  Botanische  Zeitung'  for  1880,  6  plates,  com- 
prising 120  figures,  illustrative  of  the  devcloiiment  of  the  prothallia 
of  various  ferns,  found  among  the  papers  left  by  the  late  lamented 
young  botanist  Dr.  H.  Bauke.  The  following  are  the  species  illus- 
trated: —  Platycertum  grande,  Lygodium  japoniciim,  Gijmnogramme 
tartar ea,  G.  L' Herminieri,  G.  decomposiia,  Asjjlenium  plantagineiim, 
Allosorus  rotundifolius,  Davallia  pyxidata,  and  Hemitelia  gigantea. 
Thero^is  no  accompanying  letterpress. 

Non-Sexual  Reproduction  of  the  Prothallium  of  Ferns  by 
means  of  Gemmae  or  Conidia.f — It  has  been  recorded  by  many 
observers  that  the  prothallium  of  ferns  can  increase  by  the  separation 
of  normal  branches  formed  at  the  apex,  as  well  as  more  frequently  by 
that  of  adventitious  shoots  detached  from  the  margin  or  surface. 
Tuberous  swellings  have  also  been  observed  on  the  prothallium  of 
Gymnogramme  and  Hymenophyllum,  but  their  detachment  and  germi- 
nation have  not  been  followed  out. 

Professor  Cramer  now  records  the  formation  of  true  non-sexual 
reproductive  organs  on  the  prothallium  of  an  (unnamed)  tropical  fern. 
The  prothallia  having  been  kept  for  some  time  in  a  watch-glass  with 
water,  produced  green  filamentous  excrescences,  which  were  found  on 
examination  to  be  confervoid  prothallia  furnished  with  sexual  repro- 
ductive organs  and  with  abundance  of  gemmae  or  conidia.  The  whole 
confervoid  structm'C  was  from  1  to  1  •  5  cm.  in  thickness  ;  the  separate 
filaments  were  partly  expanded  flat  on  the  substratum  (herpoblasts  of 
Cramer),  partly  growing  in  an  ascending  direction  (orthoblasts). 
Antheridia  were  frequently  observed  on  them,  archegonia  only  twice. 

The  gemmfB  were  produced  especially  at  the  extremities  of  the 
orthoblasts.  When  fully  developed  they  had  somewhat  the  form  of  a 
Clostcrium,  consisting  of  a  curved  row  of  six  or  eight  or  more  cells 
rich  in  chlorophyll  and  starch,  and  of  a  bright  green  colour.  In 
course  of  time  they  became  detached,  and  in  some  cases  gave  birth  to 
secondary  gemmae ;  in  other  cases  they  directly  bore  antheridia. 

Professor  Cramer  comjjares  this  production  of  secondary  proto- 
nema-like  prothallia  in  ferns  to  a  similar  well-known  phenomenon  in 
Heimtica).  From  a  phylogcnetic  point  of  view  he  considers  that  it 
indicates  the  origin  of  vascular  cryptogams  and  mosses  by  parallel 
lines  of  descent  from  algoid  plants,  rather  than  the  direct  descent  of 
tho  former  from  tlie  latter. 

Amphibious'  Nature  of  the  Prothallium  of  Polypodiaceae.J — 
Dr.  A.  Dodel-Port  describes  tho  jieculiar  behaviour  of  prothallia  of 
Asjndinm Jillx-viaa  and  violasccus  wliich  ho  had  kt^pt  for  a  kngthened 

*  Ana  dcm  botauischen  Nachlasse  von  Dr.  H.  Baukc ;  supplement  to  '  Bot. 
Zeit.,'  xxxviii.  (1880). 

t  '  Deiikschr.  Sdnvoiz.  Nuturf.  Ges..'  xxviii.  (1880). 
i  'Kobinos,'  iv.  (1880)  p.  II. 


830  RECORD   OF    CURRENT   RESEARCHES   RELATING   TO 

period  beneath  a  cover-glass  flooded  with  water.  A  part  of  the 
prothallium  having  decayed,  there  sj^rung  from  all  parts  of  the  sound 
portion  a  number  of  peculiar  conferva-  or  protonema-like  adventitious 
shoots.  The  production  of  similar  adventitious  shoots  was  easily 
excited  in  other  healthy  prothallia  by  placing  them  in  similar  con- 
ditions. After  the  lapse  of  time  these  adventitious  shoots  exhibited 
a  tendency  towards  lateral  branching,  thus  becoming  secondary 
adventitious  prothallia.  This  is  regarded  by  the  author  as  ex- 
hibiting an  interesting  phylogenetic  affinity  with  the  conferva-like 
protonema  of  mosses.  The  prothallium  of  a  fern  must  be  looked  on 
as  an  amphibious  structure  intermediate  in  its  vegetative  and  repro- 
ductive properties  between  aquatic  and  terrestrial  structures. 

Synopsis  of  the  Species  of  Isoetes.* — Mr.  J.  G.  Baker  distin- 
guishes 46  species,  of  which  he  gives  brief  diagnoses,  dividing  them 
into  4  groups  as  follows  : — 

I.  Aquatics. 
Velum  nullum.     1.  I.  triquetra  A.  Br.      2.  I.  Gunnii  A.  Br.     3.  I. 

elatior  F.  M. 
Velum   partiale.      4.  I.    lacustris  L.     5.  I.  echinospora   Dur.     6.  /. 

azorica  Dur.     7.  I.  jjygmce.a  Engelm. 
Velum  completum.     8.  I.  Stuartii  A.  Br,     9.  I.  Lechleri  Metten. 

II.    SUBAQtJATIC^. 

A.  North  American  species,  with  a  2-lobed  rootstock. 

Velum  partiale.    10.  I.  Bolander I 'Engelm.    11.  I.  TucJcermani  A.Br. 

12.  I.  saccharata  Engelm,     13.  I.  riparia  Engelm. 
Velum  completum.     14.  I.  nielanospora  Eugelm. 

B.  Australian  and  New  Zealand  Species,  with  a  3-lobed  rootstock. 
15.  I.  Mijlleri  A.  Br.      16.  I.  Kirhii  A.  Br.     17.    I.  alpina  Kirk. 
18.  I.  Drummondii  A.  Br. 

III.    AMPHIBIiE. 

A.  Eootstock  2-lobed  (all  North  American  species). 

Velum  partiale.     19.  J.  Butleri  Engelm.     20.  I.  melanopoda  J.  Gay. 

21.  I.  Engelmanni  A.  Br. 
Velum  completum.     22,  I.  NuttalUi  A.  Bx*.     23.2.  fiaccida  Shuttle w. 

B.  Eootstock  3-lobed. 

1.  Species  of  the  Mediterranean  region  : — 

Velum  nullum  s.  parum  evolutum.      24.    I.  setacea  Bosc.      25.    /. 

adspersa  A.  Br.     26.  1.  malinverniana  Cs.  et  de  Not. 
Velum  fere  s.  totum  completum.     27.  I.  velata  A.  Br.     28.  I.  Peral- 

deriana  Dur.  et  Letouru.     29.  I.  dubia  Gennari.     30.  I.  tegulensis 

Gennari.     31.  I.  Boryana  Dur.     32.  I.  tenuissima  Boreau.     33. 

I.  olympica  A.  Br. 

2.  Species  of  Tropical  Africa  : — 

34.  I.  Wchcitschii  A.  Br.     35.  I.  nigritiana  A.  Br.      36.  I.  Schwein- 
furthii  A.  Br.     37.  I.  cequinoctialis  Welw. 

*  '  Trim.  Joiu-n.  Bot.,'  ix.  (1880)  pp.  G")  and  105. 


INVERTEERATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  831 

3.  Species  of  Japan  and  Tropical  Asia : — 

38.  I.  japonica  A.  Br.     39.  I.  coromandeliana  Linn.      40.  I.  hrachj- 
glossa  A.  Br. 

4.  Species  of  Australia : — 

41.  I.  tripus  A.  Br. 

5.  Species  of  Tropical  America  : — 

42.  I.  amazonica  A.  Br.     43.  I.  cuhana  Engelm.     44,  I.  Gardneriana 

Kunze. 

IV.  Terrestres. 
45.  I.  Duriaei  Bory.     4G.  I.  Hystrix  Bory. 

Of  these  46  species,  the  3  following  are  new :  I.  Schweinfurtlm 
A.  Br.  ms.  Eootstock  3-lobed.  Habit  of  I.  setacea.  Leaves 
12-30,  about  a  foot  long,  moderately  firm  in  texture,  opaque,  tapering 
to  the  point,  \-\  lin,  diam.  at  the  middle,  furnished  with  stomata 
and  accessory  bast-bundles.  Sporange  small,  globose ;  veil  none. 
Macrospores  small,  chalk-white,  with  high  ridges  and  strongly  honey- 
combed all  over.  Central  Africa.  I.  amazonica  A.  Br.  ms.  Eootstock 
3-lobed.  Leaves  10-20,  2-3  inches  long,  i-J  lin.  diam.  at  the  middle, 
firm  in  texture,  furnished  with  stomata  and  accessory  bast-bundles, 
with  a  membranous  border,  about  \  inch  long,  decurrent  from  the 
dilated  base.  Sporange  small,  white,  globose,  much  spotted ;  veil 
rudimentary.  Macrospores  middle-sized,  chalk-white,  closely  strongly 
tubercled,  I.  cuhana  Engelm.  ms.  Eootstock  3-lobed.  Leaves 
10-50,  ^-1  foot  long,  \  lin.  diam.  at  the  middle,  opaque,  moderately 
firm  in  texture,  furnished  with  stomata  and  accessory  bast-bundles, 
the  membranous  base  suddenly  dilated.  Sporange  small,  oblong, 
unspotted  ;  veil  very  narrow.  Macrospores  small,  strongly  tubercled. 
Microspores  papillose.     Cuba. 

Muscineae. 

Structure  of  Dumortiera.* — With  the  exception  of  the  Eielleae, 
Dumortiera  is  described  as  the  only  genus  of  true  Marchantiaccfe 
which  wants  the  usual  layer  of  air-chambers  with  the  stomata,  as 
well  as  the  ventral  scales.  H.  Leitgeb  has  subjected  the  genus  to 
close  examination  with  a  view  of  confirming  or  otherwise  this  state- 
ment, the  species  specially  examined  being  D.  irrigua  and  Jiirsuta. 

His  conclusion  is  that  at  least  these  two  species  exhibit  a  complete 
uniformity  with  the  normal  Marchantiacejc,  at  all  events  in  an  early 
stage,  in  the  possession  of  a  layer  of  air-chambers  and  of  stomata,  in 
tlie  formation  of  the  veutral  scales,  and  in  jiossessing  both  kinds  of 
rhizoids,  the  unthickcned  and  the  conical.  The  only  difference  con- 
sists in  the  fact  that  the  cover  to  the  air-chambers,  which  represents 
the  epidermis,  and  the  ventral  scales,  iierish  at  an  early  period.  The 
walls  of  the  chambers  and  the  layer  of  cells  which  form  tluir  floor 
then  alone  remain,  and  the  latter  presents  the  appearance  of  being  the 
true  epidermis.  Whether  this  is  the  case  with  all  undoubted  species 
of  Dumortiera  remains  yet  to  be  determined. 

A  specimen  sent  from  New  Zealand  as  Dumortiera  dilatata  was 
*  '  Flora,"  Uiii.  (18.v0)  p.  307. 


832  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

determined  by  the  author  to  be  a  male  specimen  of  a  Monoclea,  and 
this  is  also  the  case  with  specimens  in  herbaria  bearing  this  name. 
Professor  Leitgeb  is  in  doubt  whether  D.  dilatata  has  any  existence  at 
all,  and  whether  all  specimens  so  named  do  not  belong  to  a  hitherto 
undescribed  species  of  Monoclea,  which  should  be  called  M.  dilatata; 
belonging  therefore  not  to  the  Marchantiaceae,  but  to  the  Jungerman- 
niacesB. 

Formation  of  the  Sporogonium  of  Archidium.* — This  genus  of 
mosses  is  of  special  interest  as  presenting  a  point  of  contact  between 
the  Phascacese  and  Bryineae,  and  at  the  same  time  exhibiting  points 
of  resemblance  to  the  Hepaticae.  Professor  Leitgeb  has  made  the 
structure  and  mode  of  formation  of  the  sporogonium  a  subject  of 
special  study. 

The  author  regards  the  sporogonium  of  all  Musci  (including 
Sphagnaceae)  as  consisting,  in  its  earliest  stage  of  development,  of 
an  inner  mass  of  cells,  the  endothecium,  which  is  distinctly  separated 
from  a  peripheral  mass,  the  amphithecium.  According  to  the  mode 
in  which  the  spores  are  developed,  he  distinguishes  the  following 
types  : — 

A.  Spores  formed  from  the  amphithecium. 

1.  Sphagnacece  type.    The  endothecium  produces  only  the 

columella,  which  however  does  not  penetrate  the 
spore-forming  layer,  but  is  covered  by  it. 

B.  Spores   formed    from    the   endothecium.      The    sporogonium 

always  grows  by  means  of  a  two-edged  apical  cell. 

2.  Archidium  type.     Spore-forming  and  sterile  cells  are 

intermingled  in  the  endothecium ;  the  spore-sac  is 
separated  from  the  wall  of  the  capsule  by  a  bell- 
shaped  cavity. 

3.  Andreceacece  type.     The  endothecium  is  differentiated 

into  a  spore-forming  layer  and  the  columella  which 
does  not  penetrate  the  former.  The  innermost  layer 
of  the  amphithecium  becomes  the  spore-sac,  which 
however  is  not  separated  from  the  wall  of  the  capsule 
by  any  cavity. 

4.  Bryinece  type.     The  endothecium  is  differentiated  as 

in  No.  3  ;  but  the  columella  penetrates  the  spore-sac, 
which  is  sejjarated  from  the  wall  of  the  capsule  by  a 
cylindrical  cavity. 
The  following  are  the  most  noteworthy  points  in  connection  with 
the  development  of  the  spores  and  sporogonium  of  Archidium  :  — 

1.  In  the  first  stages  of  the  development  of  the  sporogonium  until 
the  differentiation  of  the  amjihithecium  and  endothecium,  Archidium 
agrees  with  the  other  Phascaceae. 

2.  The  same  is  the  case  also  with  regard  to  the  formation  of  the 
outer  spore-sac ;  but  this,  as  in  the  Andreaeacefe,  covers  the  inner 
tissue  as  a  closed  bell-shaped  layer,  and  is  separated  from  the  wall  of 
the  capsule  by  a  cavity. 

*  '  SB.  k.  k.  Akad.  Wiss.  (Wien),'  Ixxx.  (1880)  p.  447. 


INVERTEBRATA,   CRYPTOGAMIA,    MICROSCOPY,    ETC.  833 

3.  The  inner  tissue  does  not  originally  exhibit  any  differentiation 
into  spore-forming  layer  and  columella.  A  few  cells,  undefined  both 
in  position  and  number,  which  varies  from  one  to  seven,  become  the 
mother-cells  of  the  spores,  in  each  of  which  four  spores  are  formed 
tetrahedrally. 

4.  The  cells  of  the  spore-space  which  remain  sterile,  as  well  as 
those  of  the  inner  layer  of  the  spore-sac,  and  of  the  two  inner  layers 
of  the  wall  of  the  capsule,  are  subsequently  again  absorbed,  while  the 
outer  layer  of  the  spore-sac  remains,  almost  until  the  spores  are  ripe, 
in  the  upper  part,  but  altered  so  as  to  be  hardly  recognizable,  and 
appearing  as  a  homogeneous  membrane. 

5.  In  respect  to  the  processes  which  are  carried  on  in  the  spore- 
space — the  differentiation  into  spore-mother-cells,  which  are  irregularly 
interspersed,  and  cells  which  remain  sterile — Archidiuni  resembles 
the  Hepaticfe  more  closely  than  the  Bryinete.  The  resemblance  is 
especially  close  to  the  Riellea),  with  which  it  agrees  also  in  the 
structure  of  the  calyptra. 

Transition  of  Female  to  Male  Organ  in  a  Moss.* — This  pheno- 
menon, probably  never  before  observed  in  cryptogams,  is  recorded 
by  Lindberg  in  Hyimum  eri/throrhizon.  A  barren  female  plant 
showed  some  altogether  abnormal  perichaetia ;  these  proved  to  consist 
on  one  side  of  forms  resembling  the  ordinary  female  organs,  on  the 
other,  of  organs  approximating  to  the  structure  of  antheridia.  These 
latter  were  almost  cylindrical  from  the  base  upwards,  instead  of 
having  the  pear-shaped  form  of  the  archegonium :  their  interior  was 
found  to  contain  a  substance  resembling  dried  spermatozooids  ;  no 
female  central  cell  could  be  distinguished  among  them.  The  upper 
edge,  however,  is  circular,  and  presents  a  level  plane  with  a  central 
invagination,  as  in  normal  antheridia.  The  same  j)lant  bore  regular 
and  typical  archegonia  of  a  narrow  flask-like  shape  with  a  long  neck ; 
the  upper  end  has  a  projecting  rim  with  more  or  less  distinct  lijjs  ; 
the  central  cells  are  also  present,  as  usual.  The  discovery  of  the 
hermaphrodite  species,  H.  reflexum,  described  by  Blytt,  bears  out  the 
correctness  of  the  present  observation ;  it  is  possibly  merely  a 
similar  specimen  of  H.  erylTirorhizon,  wrongly  identified. 

Fungi. 

New  Genera  of  Fungi. t — Sig.  Saccnrdohas  compiled  a  conspectus 
of  the  fungi  found  in  Italy,  belonging  to  the  class  known  as  "  Fungi 
impcrfecti,"  and  regarded  by  tlie  majority  of  mycologists  as  early 
forms  of  the  Ascomycotos  and  other  higher  fungi. 

He  classifies  them  iirst  under  three  divisions,  the  Spl.asroi)sidcte, 
^relanconicfc,  and  Hyplidinycetca?.  The  Sphfcropsidea;  are  further 
divided  into  throe  sections,  the  Sphrcroidc  .t,  Dimid'ato-scjitatai,  and 
Subcnpulat«3.  Within  each  section  the  form  and  colour  of  the  spores 
are   the  characters  used  for  further  classification.     In  the  Mclanco- 

•  'Oefv.  K.  Vet.  Akad.  F.irli.'  (8torklif.lin)  1870,  Xo.  .",.  p.  7")  (1  \^n\o). 
t  '  Miclieliii,'  1880,  p.  1.     See  '  IJot.  (.'cntrnlM.,'  i.  (IH80)  p.  .'il.'i. 
VOL.    III.  3    I 


834  RECORD   OF   CURRENT    RESEARCHES  RELATING   TO 

niese  there  is  no  further  division  into  sections.  In  the  Hyphomycetese, 
the  largest  of  the  three  divisions,  there  are  four  sections,  the  Muce- 
dincss,  Dematiese,  Didymosporfe,  and  Tubercularieas,  with  numerous  sub- 
divisions. 214  genera  are  described,  among  them  the  following  new 
to  science : — 

Dendrophoma  Sacc.  Perithecia  calva  Phomce,  sed  basidia  ramulosa 
vel  denticulata  pleiospora.  Dothiorella  Sacc.  Stroma  basilare  ;  peri- 
thecia botryose  aggregata  ;  sporaj  oblongse.  SeptaglcBum  Sacc.  Conidia 
oblonga,  2-pluriseptata,  hyalina  (est  Gloeosporium  conidiis  plarisep- 
tatis).  Ovularia  Sacc.  Biophila ;  hyphae  subsimplices,  erectfe,  api- 
cem  versus  conidia  globosa  vel  ovoidea  gerentes.  Pyricularia  Sacc. 
Hyphas  biogente  subsimplices ;  conidia  obclavato-pyriformia,  2-pluri- 
septata, solitarie  acrogena.  Cercosporella  Sacc.  Candida,  biogena ; 
hyphse  simplices  vel  ramulosfe ;  conidia  vermicularia,  pluriseptata 
(est  Cercospora  mucedinea).  Dactylaria  ■  Sacc.  Saprophila  ;  hyphee 
fertiles  erectee,  simplices,  apice  capitulum  conidiorum  gerentes ; 
conidia  fusoidea  vel  clavulata,  2-pluriseptata.  Heterobotrys  Sacc. 
Conidia  catenulata  vel  simul  glomerulata,  sphaeroidea,  in  eodera 
mycelio  majora  et  minora,  fuliginea  et  hyalina ;  hyphse  a  conidiis  vix 
distinctfe.  Ceratophorum  Sacc.  Conidia  phyllogena  fusoidea  vel 
cyliudracea,  sursum  incurvata  et  pallidiora.  Stigmina  Sacc.  Conidia 
ovoidea  vel  oblonga,  2-pluriseptata,  in  acervulos  aggregata,  phyllo- 
gena, basidiis  brevibus  fulta.  Gonatobotryum  Sacc.  Hyphse  fuscfe,  sim- 
plices, erectfe,  hinc  inde  noduloso-inflatae,  ibique  denticulato-sporigerse  ; 
conidia  ovoidea.  3Iesohofrys  Sacc.  HyphaB  Chcetopsidis ;  conidia 
ovoidea.  Harpographiiim  Sacc.  Conidia  falciformia,  continua,  hyalina. 
Cosmariospora  Sacc.  Conidia  constricto-didyma,  verruculosa,  hyphis 
tenuissimis  ramulosis  varie  inserta ;  sporodochium  verruciforme,  super- 
ficiale,  botryoideo-lobatum.  Tiiberculina  Sacc.  Conidia  in  basidiis 
crassiusculis  brevibus  simplicibus  vel  parce  ramulosis  acrogena,  glo- 
bulosa;  sporodochium  plano-pulvinatum.  Heliscus  Sacc.  Sporodo- 
chium applanatum  ;  conidia  cylindracea,  apice  clavi  ad  instar  poly- 
gono-capitata,  mediocria,  basidiis  parce  divisis  nixa.  Strumella  Sacc. 
Sporodochium  verruciforme,  ex  hyphis  varie  ramosis  conidiisque  ex 
ovoideo  polymorphis  varie  adnatis  compositum. 

Mode  of  Escape  of  the  Spores  from  the  Asci  in  Ascomycetes.* 
— This  point  has  been  carefully  investigated  by  W.  Zopf,  with 
the  following  results: — In  Sordaria  the  asci  project  through  the 
ostiolum  of  the  pcrithecium,  in  consequence  of  elongating  very  consi- 
derably, and  then  first  buret.  In  all  the  Ascomycetes  in  which  the 
spores  are  forcibly  ejected,  they  are  connected  together  by  various 
contrivances,  sometimes  by  appendages,  sometimes  by  a  gelatinous 
envelope.  These  collections  of  spores  are  frequently  attached  to  the 
apex  of  the  ascus  in  various  ways,  a  point  of  importance  in  their  ejec- 
tion. Heliotropism  j)lays  its  part  not  only  in  the  entire  perithecium, 
but  also  in  the  separate  asci.  The  Pyrenomycetos,  which  have  no 
ostiolum,  often  exhibit  contriva,nces  for  facilitating  the  opening  of  the 

*  'SB.  Ges.  natuif.  Freimde  Berlin,'  1880,  p.  29.  See  '  Bot.  Ceutralbl.,'  i. 
(1880)  p.  323. 


INVERTEBRATA,    CRYPTOGAMIA,   MICROSCOPY,    ETC.  835 

perithecium  and  the  escape  of  the  spores.  In  Choitomium  fimeti  there 
are  at  the  base  of  the  perithecium  very  hygroscoiiic  hair-like  appen- 
dages, which  attach  themselves  to  other  objects,  and  by  their  elasticity 
burst  the  perithecium.  In  Cephalotlieca  tdbulata  n.  sp.  (possibly  iden- 
tical with  Eurothim  pulcherrimiim),  the  wall  of  the  perithecium  consists 
of  polyhedral  shields,  separated  by  a  layer  of  a  delicate  tissue,  which 
are  easily  forced  apart  by  the  pressure  of  the  asci. 

Fungus-parasites  of  the  Aurantiacese.* — A.  Cattaneo  contributes 
a  list,  with  descriptions,  of  no  less  than  34  species  of  fungus  parasitic 
on  the  orange  and  its  allies,  including  the  following  new  species : — 
Sclerotium  Citri,  on  rotten  lemons ;  Plioma  Hesperidearum,  on  living 
leaves ;  Seploria  Hesperidearum,  on  leaves ;  Gloeosporium  Hesperi- 
dearum, on  living  leaves ;  Hysterium  Aurantii,  on  dry  wood  of  the 
orange ;  Cryptovalsa  Citri,  on  roots  which  have  lost  their  bark. 

Fungi  parasitic  on  Forest-trees.f  —  E.  Eostrup  publishes  a 
memoir  on  the  fungi  parasitic  on  forest-trees  in  Denmark,  excluding 
the  Uredinca),  which  have  been  previously  treated  of.  The  species 
specially  described  are  Agaricus  melleus  and  osireaius,  Trametes  radi- 
ciperda  and  Pini,  P ohjpor us  foment ari us,  igniarius,  conchatus,  radiatus, 
sulphureus,  siiaveolens,  and  populinus,  Thelephora  laciniata,  Stereum 
hirsutum,  Corticeum  sulphureum,  Gymnoasci,  Peziza  WillJcommi,  Hliy- 
tisma,  Lophodermium,  Hypoderma,  Ustulina,  Nectria  ditissima,  Phylla- 
chora,  Cladosporium,  Eriisiphei,  Phytophthora  Fagi,  and  Schinzia  Aim. 

Agaricus  melleus  is  destructive  not  only  to  all  Coniferas,  with  the 
exception  of  the  silver  fir,  but  attacks  and  kills  many  other  trees, 
especially  the  beech,  hornbeam,  alder,  bircli,  poplar,  willow,  sycamore, 
and  mountain  ash.  It  is  especially  injurious  to  young  pines  of  from 
five  to  ten  years  old.  Among  the  other  most  destructive  fungi  are 
Trametes  radiciperda  and  Nectria  ditissima,  while  it  is  shown  that 
several  species  of  P  ohjpor  us  arc  true  parasites. 

Witch-broom  of  the  Cherry  (Exoascus  WiesnerD.t — The  peculiar 
deformity  of  the  cherry,  birch,  &c.,  known  as  "  Hcxeubesen,"  or  "  witch- 
broom,"  is  stated  by  De  Bary,  in  his  'Morphologic  u.  Physiologie  der 
Pilzo,'  not  to  be  caused  by  parasitic  fungi,  but  to  be  of  .unknown 
origin.  E.  Rathay  believes,  on  the  contrary,  tliat  he  has  established 
that  this  disease  is  caused  in  the  cherry  by  Exoascus  deformans  Ccrasi 
Fckl,,  the  mycelium  of  which  persists  in  the  malformation,  branching 
out  each  year  into  tlic  young  shoots,  and  forming  its  liymenium  in 
May  on  the  under  side  of  the  leaves  between  the  cuticle  and  tlio 
epidermal  cells. 

Exoascus  deformans.  Cerasi  lias  a  well-developed  mycelium,  and 
8-spored  asci,  and  is  therefoi'o  well  placed  in  this  genus.  It  difftrs 
specifically  from  the  E.  deformans  PersiccB  Fckl.  of  the  peach,  for 

•  '  Arcliivio  labomt.  Botnn.  Crittognin.  di  Pavia,'  iii.  (1870).  Sec  'lit. 
Ceiitralbl.,'  i.  (18.^0)  p.  450. 

t  'Tidsskr.  for  Skovbrii^' '  (CoppDlinjrrn),  iv.  (1880)  p.  I. 
X  'Oestorr.  Dot.  Zeitschr.,'  xxx.  (18S0)  p.  225. 

3  I  2 


836  RECORD   OF    CURRENT   RESEARCHES    RELATING    TO 

which  reason  Rathay  proposes  to  confer  on  it  the  specific  name 
Exoascns  Wiesneri  Eathay.  Besides  Priinus  avium,  it  occurs  also 
on  P.  Cerasus  and  Chamcecerasus,  causing  similar  broom-like  mal- 
formations. 

New  Vegetable  Structures  from  Coal  and  Anthracite. — In  a 
separate  communication,  Herr  Paul  F.  Eeinsch  gives,  with  two  jilates, 
an  account  of  some  of  the  results  of  his  long  researches  into  the  flora 
of  past  epochs.  The  dejiosits  mentioned  are,  he  believes,  largely  com- 
jDOsed  of  microscopic  vegetable  structures  of  extreme  simplicity.  In 
the  older  Devonian  strata  (of  Illinois)  he  has  found  bodies  which  have 
some  resemblance  to  the  Myxomycetes,  and  these  he  has  found  again 
in  other  parts  of  North  America,  and  he  has  been  able  to  trace  them 
to  Upper  Jurassic  formations.  Taking  altogether  the  numerous 
localities  in  which  he  has  found  them,  he  is  certain  that  the  coal  is  in 
no  way  made  up  of  the  remains  of  the  higher  plants,  which  are  in 
comparatively  small  proportion  as  comj)ared  with  vegetable  forms  of 
the  very  lowest  grade. 

The  most  remarkable  body  which  he  has  met  with  is  a  strongly 
polarizing  substance,  which  is  either  found  in  regular  isolated 
spheres  and  polygonal  bodies,  or  in  mass  in  the  clefts  of  crystals. 
Where  most  constant  in  size  and  structure,  they  are  0"  5-2 '5  mm. 
high,  formed  of  a  dark  grey,  hard,  horny  substance,  of  a  rather  higher 
specific  gravity  than  ordinary  coal,  and  made  of  spheres  0  •  13-0  *  24  mm. 
in  diameter.  The  spheres  consist  of  a  radially  arranged,  more  or 
less  brown,  granular  substance,  with  scarcely  any  indication  of  a  con- 
centric striation.  They  hardly  resemble,  morphologically,  any  plants 
already  known  to  us,  and  it  will  be  necessary  to  form  for  them  a 
sj)ecial  division. 

After  giving  a  detailed  account  of  their  structure,  the  author  says 
that,  it  being  certain  that  we  have  not  here  to  do  with  "  mineral 
bodies,"  it  follows  that  either:  (1)  they  are  crystals  formed  from  the 
dissolution  of  some  organic  compound,  comparable  to  the  "  sphtero- 
crystals  "  deposited  from  alcoholic  or  aqueous  solutions  of  chenopodin  ; 
or  (2)  they  are  organized  bodies,  which  are  either  independent  plants 
(comi^arable  to  the  unicellular  Fungi  and  Algae  of  the  present  j^eriod), 
or  they  are  parts  of  some  other  plant.  The  author  is  distinctly  in 
favour  of  the  facts  speaking  to  one  or  other  of  the  two  latter  views. 
He  forms,  therefore,  two  genera,  which  he  characterizes  thus  :  Blasto- 
phragmium,  with  the  body  formed  of  three  difterent  substances  : — 

a.  A  fibrillar,  multiramified,  filamentar  substance. 

5.  Pellucid  substance  intermixed  with  granules  0  •  0008  mm.  in 
diameter,  and  with  pellucid  fibrillse  arranged  in  longitudinal  rows. 

c.  Semipellucid  polarizing  substance  formed  of  centrogranular 
granules,  arranged  radially,  and  forming  regular  spheres ;  the  system 
of  the  tubules  simple,  the  "  tubules  "  arranged  radially,  closely  com- 
pressed, and  all  of  the  same  length. 

The  second  genus,  Asterophragmiutn,  is  composed  of  only  two  sub- 
stances ;  one  is  granular  and  non-pellucid,  and  the  other  semi- 
pellucid, and  possessed  of  polarizing  properties. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  837 

Classification  of  Bacteriacese.* — In  a  general  review  of  our  state 
of  knowledge  of  tlie  Schizomycetes,  Dr.  Luersscn  arranges  the  genera 
of  BacteriacenB  as  follows  : — 

I.  Cells  not  united  into  filaments,  sejiarating  immediately  after 
division,  or  in  couples,  free  or  united  into  colonies  (Zoogloea) 
by  a  gelatinous  substance. 

A.  Cells  dividing  in  one  direction  only. 

a.  Ccdls  globular  :  Micrococcus. 

p.  Colls  elliptical  or  shortly  cylindrical :  Bacterium. 

B.  Cells  dividing  regularly  in  three  directions,  and  thus 

forming    cubical    families,    having    the    form    of 
packets  strung  crosswise,  and  consisting  of  4,  8, 
16,  or  more  cells  :  Sarcina. 
II,  Cells  united  into  cylindrical  filaments. 

A.  Filaments  straight,  imperfectly  segmented. 

a.  Filaments  very  fine   and  short,  forming  rods : 

Bacillus. 
(3.  FiLiments  very  fine  and  very  long  :  Leptothrix. 
y.  Filaments  thick  and  long  :  Beggiatoa. 

B.  Filaments  wavy  or  spiral, 

a.  Filaments  short  and  stiff. 

a.  Filaments   slightly  wavy,  often   forming 

woolly  flocks  :    Vibrio. 

b.  Filaments  spiral,  stiff,  moving  only  for- 

wards or  backwards :  Spirillum. 
(3.  Filaments  long,  flexible,  with  rapid  undulations, 
spiral  through  their  whole  length,  and  en- 
dowed with  great  mobility :  Spii-ochcete. 
A  diagnosis  follows  of  each  species,  with  an  account  of  what  is 
known  of  its  structure  and  habits,  and  of  its  physiological  role. 

Atmospheric  Bacteria. t — Continuing  the  observations  contained 
in  a  previous  paper,  |  which  did  not  deal  with  Bacteria,  M.  Miquel  has 
succeeded  in  counting  tlic  spores  of  bacteria,  and  while  couflrming 
M.  Pasteur's  observations  that  they  are  always  present  in  the  air, 
shows  that  their  number  is  subject  to  incessant  variations. 

Very  small  in  winter,  the  number  increases  in  spring,  is  very  high 
in  summer  and  autumn,  then  sinks  rapidly  when  frost  sets  in.  This 
law  also  applies  to  spores  of  fungi ;  but  while  the  spores  of  moulds 
are  abundant  in  wet  periods,  the  number  of  aerial  bacteria  then 
becomes  very  small,  and  it  only  rises  again  in  drought  when  the 
spores  of  moulds  become  rare.  Thus,  to  the  maxima  of  moulds 
correspond  the  utinlma  of  bactia-ia,  and  reciprocally. 

In  summer  and  autumn,  at  Paris,  lOUO  germs  of  bacteria  are 
frequently  found  in  a  "cubic  metre  of  air.  In  winter  the  number  not 
tincouimonly  descends  to  four  and  five,  and  on  soini!  days  tlio  "  dust " 
from   2U0  litres  of  air  proves  iiicai)ablo  of  causing  infection  of  the 

♦  '  Rev.  Iiiternat.  Sci..'  iii.  (1S80)  p.  242. 
t  '  CompU's  Kendiis,'  xci.  (1880)  p.  04. 
X  See  tliis  Juurnal,  i.  (1878)  p.  1U2. 


838  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

most  alterable  liquors.  In  the  interior  of  houses,  in  the  absence  of 
mechanical  movements  raising  dust  from  the  surface  of  objects,  the 
air  is  fertilizing  only  in  a  volume  of  30  to  50  litres.  In  M.  Miquel's 
laboratory,  the  dust  of  5  litres  usually  serves  to  effect  the  alteration 
of  neutral  bouillon.  In  the  Paris  sewers,  infection  of  the  same  liquor 
is  produced  by  particles  in  1  litre  of  air. 

These  results  differ  considerably,  it  is  pointed  out,  from  those 
published  by  Tyndall,  who  says  that  a  few  cubic  centimetres  of  air 
will,  in  most  cases,  produce  infection  in  the  most  diverse  infusions. 

M.  Miquel  compared  the  number  of  deaths  from  contagious  and 
epidemic  diseases  in  Paris  with  the  number  of  bacteria  in  the  air 
dui'ing  the  period  from  December  1879  to  June  1880,  and  established 
that  each  recrudescence  of  aerial  bacteria  icas  followed  at  about  eiglit 
days'  interval  by  an  increase  of  the  deaths  in  question.  Unwilling  to 
say  positively  that  this  is  more  than  a  mere  coincidence,  he  projects 
further  observations  regarding  it. 

Bf .  Miquel  further  finds  (contrary  to  some  authors)  that  the  water- 
vapour  which  rises  from  the  ground,  from  rivers,  and  from  masses  in 
full  putrefaction,  is  always  micrographically  pure ;  that  gases  from 
buried  matter  in  course  of  decomposition  are  always  exempt  from 
bacteria  :  and  that  even  impure  air  sent  through  putrefied  meat,  far 
from  being  charged  with  microbia,  is  entirely  purified,  provided  only 
the  putrid  filter  be  in  a  state  of  moisture  comparable  to  that  of  the 
earth  at  •  3  metre  from  the  surface  of  the  ground. 

Modification  of  the  Properties  of  Bacillus  anthracis  by  Culti- 
vation.*— In  the  course  of  some  experimental  investigations  into  the 
pathology  of  anthrax  at  the  Brown  Institution,  made  during  the  past 
twelve  months,  two  series  of  phenomena  have  been  the  subject  of 
study,  and  in  each  some  results  have  been  attained  which  Professor 
W.  S.  Greenfield  (in  a  "  preliminary  note  ")  believes  to  be  novel,  and 
of  considerable  practical  importance  if  verified  by  other  observers. 

The  practical  purpose  of  these  investigations  was  to  ascertain 
(1)  by  what  means  the  virus  of  splenic  fever  may  be  so  modified  as 
to  be  capable  of  inoculation  without  fatal  result,  and  (2)  whether  a 
modified  attack,  produced  by  inoculation,  exerts  any  protective 
influence  against  a  futm*e  inoculation  with  unmodified  virus. 

The  conclusions  arrived  at  by  these  experiments  were  as  follows : — 

1.  That  anthrax  may  be  artificially  communicated  to  bovine 
animals  by  inoculation  with  the  blood  or  spleen  of  the  guinea-pig 
which  has  died  of  the  disease  artificially  induced,  and  that  the  same 
result  may  be  attained  by  inoculation  with  the  Bacillus  anthracis 
cultivated  from  the  fluids  of  a  rodent ;  the  disease  thus  induced  being 
severe,  but  rarely  fatal  to  previously  healthy  bovine  animals,  a  result 
previously  attained  by  Dr.  Burdon-Sanderson  independently. 

2.  In  all  the  cases  thus  inoculated,  the  animals  appeared  to  have 
acquired  either  a  considerable  degree  of  protection  or  entire  immunity 
from  the  results  of  subsequent  inoculation,  although  much  larger 
doses  of  the  virus  were  employed. 

*  '  Proc.  Eoy.  Soc.,'  xxx.  (1880)  p.  557. 


mVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  839 

In  tlie  course  of  these  experiments  the  author  employed  on  several 
occasions  Bacillus  antliracis  artificially  cultivated  in  successive  gene- 
rations in  aqueous  humour,  and  finding  that  the  results  appeared  to 
vary  considerably  with  the  stage  of  the  cultivation,  those  furthest 
removed  from  the  original  parent-source  being  more  frequently 
inactive,  he  was  led  to  make  a  series  of  observations  of  which  he  now 
communicates  the  results.     They  may  be  stated  as  follows : — 

That  when  Bacillus  anthracis  is  artificially  grown  in  successive 
generations  in  a  nutrient  fluid  (aqueous  humour),  it  maintains  its 
morbific  properties  through  a  certain  number  of  generations,  but  each 
successive  generation  becomes  less  virulent  than  its  predecessor, 
requiring  both  a  longer  time  and  a  larger  quantity  to  exert  its  mor- 
bific action  ;  and  after  continuous  diminution  of  virulence,  at  a  certain 
stage  in  the  successive  cultivations,  the  Bacillus,  though  maintaining 
all  its  morjiliological  characters  and  its  power  of  growth,  becomes 
completely  innocuous  even  to  the  most  susceiitible  class  of  animals. 

It  may  be  added  that  the  modified  virus  produces  forms  of  modi- 
fied disease  which  differ  widely  from  ordinary  sjilenic  fever,  both  in 
the  distribution  of  the  Bacilli  and  in  the  nature  of  the  symptoms  and 
pathological  appearances. 

In  regard  to  the  general  method  employed  in  the  determination 
of  the  gradual  diminution  of  virulence  by  successive  artificial  cultiva- 
tions, the  cultivating  fluid  was  aqueous  humour  in  closed  tubes  half 
filled,  and  the  animals  inoculated  chiefly  mice.  The  cultivations 
were  continued  to  the  nineteenth  generation,  each  successive  genera- 
tion presenting  identical  morphological  characters  at  the  various 
stages  of  its  growth,  and  showing  no  diminution  in  the  capacity  for 
growth  nor  marked  variation  in  the  time  and  temperature  relations  of 
its  germination.  In  no  case  were  any  symptoms  or  a  fatal  result 
produced  by  inoculation  with  a  later  generation  than  the  twelfth, 
beyond  that  stage,  a  large  quantity  of  actively  germinating  rods  and 
spores  produced  no  result  whatever.  The  diminution  of  virulence 
was  very  marked  at  the  eighth  generation,  both  as  regards  the  pro- 
portion of  animals  affected,  and  the  rapidity  of  action  with  an  equal 
dose. 

The  author  defers  at  present  dwelling  upon  any  conclusions  to  bo 
drawn  from  the  experiments  pending  further  investigations. 

Bacterium  foetidum :  an  Organism  associated  with  profuse 
Sweating  from  the  Soles  of  the  Feet." — Dr.  George  Thin  refers  to 
the  fiict  of  the  feet  of  certuiu  individuals  being  characterized  by  a 
peculiar  powerful  and  fa-tid  odour,  wliich  is  really  connected  with 
the  UKUsture  (an  admixture  of  sweat  with  serous  exudation  from  the 
blood)  that  soaks  the  soles  of  the  stockings  and  tlie  inside  of  the 
boots. 

"When  a  small  portion  of  the  solo  of  the  wet  stocking  was  teased 
out  in  water,  the  drop  of  water  was  found  to  bo  swarming  with  micro- 
cocci. A  second  generation  of  the  organism,  which  tlie  author  calls 
Bacterium  fatidum,  was  obtained  by  placing  a  small  piece  of  the  wet 

♦  '  Troc.  Roy.  Soc.,'  xxx.  (1880)  p.  iT3. 


840  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

stocking  in  a  test-glass,  charged  with  pure  vitreous  humour.  This 
and  succeeding  generations  were  cultivated  at  a  temperature  which 
varied  between  94°  and  98°  Fahr.  The  successive  generations  were 
obtained  by  inoculating  pure  vitreous  humour,  with  requisite  precau- 
tions. In  twenty-four  hour?  the  surface  of  the  vitreous  humour  was 
always  found  covered  with  a  delicate  scum,  which  in  forty-eight  hours 
was  compact  and  tolerably  resistant. 

In  the  scum  of  one  day's  growth  and  in  the  fluid  belo.v  it 
organisms  were  found  as  cocci,  single  and  in  pairs,  in  transition 
stages  towards  rod  formation,  as  single  and  jointed  rods,  and  as 
elongated  single  rods.  Many  of  the  rods  were  actively  motile.  The 
compact  scum  of  two  days'  growth  was  sufficiently  resistant  to  be 
removed  in  an  unbroken  sheet.  "When  disturbed  by  the  needle  it  fell 
to  the  bottom  of  the  glass.  It  was  found  to  contain  all  the  forms 
found  in  the  twenty-four  hours'  growth,  and  in  addition  long  unbroken 
rods  in  transition  stages  towards  the  formation  of  chains  of  spores. 
Spores  were  also  found  lying  beside  tlie  empty  and  partially  empty 
sheaths  from  which  they  had  been  discharged.  Groups  of  single 
spores  and  pairs,  identical  in  size  and  ajipearance  with  those  which 
had  come  to  maturity  in  the  sheaths,  were  found  mixed  up  with  rods 
in  all  phases  of  development. 

The  first  stage  in  the  development  of  the  organism  is  the  formation 
of  a  pair  from  one  coccus. 

The  next  stage  is  that  in  which  the  whole  body  is  wedge-shaped, 
the  round  brightly-refractive  coccus  being  found  in  the  thick  end  of 
the  wedge.  Another  phase,  which  is  probably  the  successor  of  the 
preceding  one,  is  the  appearance  of  a  canoe-shaped  figure  with  the 
bright  coccus  in  the  centre. 

Other  appearances  connected  with  the  early  stage  of  development, 
and  probably  following  the  wedge-  and  canoe-shaped  figures,  show 
the  organism  developed  into  a  staflf-shaped  body,  containing  two 
elements  of  very  different  refractive  power.  The  coccus  element  is 
still  distinct  and  is  brightly  refractive,  the  other  element  is  very 
slightly  refractive  and  is  seen  as  a  dull  shade,  with  however  perfectly 
distinct  outlines.  The  coccus  may  be  at  one  end  of  the  rod,  two 
cocci  may  be  in  the  centre  close  together  with  a  prolongation  of 
protoplasm  on  either  side,  or  a  central  rod  of  protoplasm  may  have  a 
coccus  at  either  end. 

In  the  next  stage  we  have  the  formation  of  the  rods  characteristic 
of  Bacteria.  The  distinction  between  the  coccus  and  the  protoplasm 
becomes  lost,  although  transitions  are  found  in  which  faint  differences 
of  refraction  still  betray  the  two  elements.  The  formation  of  rods 
of  ordinary  size,  of  long  rods  with  unbroken  protoplasm,  of  rods 
with  segmented  protoplasm,  and  of  rods  filled  with  spores  or  cocci, 
progresses  identically  with  the  similar  formation  in  Bacillus  anthracis. 

The  Bacterium  grows  in  turnip  infusion  less  actively  than  in 
vitreous  humour. 

Dr.  Thin  states  that  an  antiseptic  treatment  by  which  the  bacteria 
were  killed  in  the  stockings  and  inner  surface  of  the  soles  of  the  boots 
completely  destroyed  the  foetor. 


INVERTEBBATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  841 

Alcoholic  Fermentation.* — In  regard  to  tlie  transformation  of 
alcoholic  liquids  into  vinegar,  Pasteur,  as  is  well  known,  holds  that 
the  formation  of  vinegar  is  a  physiological  phenomenon  caused  by 
vegetation  of  Mi/coderma  aceti,  while  Liebig  sees  in  it  merely  a  chemical 
action  of  oxygen  on  alcohol.  Eecent  observations  by  Herr  Wm'm,  at 
the  Breslau  Institute  of  Plant-Physiology,  are  regarded  as  putting  the 
former  view  beyond  a  doubt,  and  Herr  Wurm  has  succeeded  in  effecting 
the  industrial  manufacture  of  vinegar  in  accordance  with  Pasteur's 
view.  The  conditions  are  a  sowing  of  pure  bacteria,  a  uniform  tempera- 
ture of  30^  C,  and  a  well-regulated  addition  of  alcohol.  The  jirocess 
goes  on  in  large  covered  wooden  receptacles  (with  side-holes  for  air), 
into  which  are  put  200  litres  of  a  mixture  of  vinegar,  water,  and  alcohol, 
along  with  some  mineral  salts  (phosphates  of  jiotash,  lime,  magnesia, 
and  ammonia).  Full  particulars  have  been  published  in  Diugler's 
'  Polytcchnischcs  Journal.'  The  manufacture  is  said  to  be  con- 
siderably more  rapid  than  that  by  the  old  method,  and  distinctly 
economical. 

Clastoderma.t — A.  Blytt  describes  a  new  genus  and  species  of 
Myxomycetcs. 

Sporangia  discreta,  calce  destituta,  stipitata.  Columella  brevis- 
sima  aut  subnulla.  Capillitium  e  columella  ortum,  ramis  solidis, 
lihicinis,  demum  lutescentibus,  repetite  bifurcatis,  ramulis  non  auasto- 
mosantibus.  Sporaugii  maturi  membrana  in  fragmenta  membranacea 
subhyalina  inter  se  libera  et  distantia  divisa.  Fragmenta  irregulariter 
rotuudata,  oblonga  aut  subpolygona,  ramulis  ultimis  capillitii  singulis 
vel  2-5  affixa.     Sporfc  lilacinaa, 

Clastoderma  Debaryianum  n.  sp.  Sporangia  sphferoidea,  diam. 
^-y  mm.  Stipes  fusco-flavescens,  ercctus,  1'3-1"4  mm.  longus, 
e  basi  latiori  versus  apicem  sensim  attenuatus  (basi  210-215  /x, 
apice  ca.  8  fx  latus),  ad  basin  columella)  anuulo  membranaceo  augus- 
tissimo  ciuctus.  Columella  subnulla,  rotundata  aut  brevissima 
(30  /m  longa),  apice  dilatato  rotundata.  Sporje  sphferoidea)  Iseves, 
diam.  9  5-1 1  /x.  Fragmentorum  membranaceorum  diametrus  10-15  fx, 
in  fragmentis  oblongis  diametrus  longior  usque  ad  30  fx  longa. 

Ilab.  in  Polyporo  emortuo,  faciei  inferiori  gregarie  insidens,  in 
silva  abicgua  propo  Farucbo  Christianise  (Xorvegia;)  mensc  Septembri 
1879  (A.  lilytt). 

Lichenes. 

Monograph  of  Arthonia.t — A  very  valuable  monograph  of  all 
the  Scandinavian  species  of  Arihonia,  referring  also  to  species 
found  elsewhere,  is  compiled  by  S.  Almquist.  The  diagnosis  of  tho 
genus  is  nearly  identical  with  that  of  Nylander  and  Leightou  : — 
Excipuhun  nullum  vel  rarissimo  ambiens  ;  epithecium  ])cridium  non 
foriiians ;  asci  pyriformcs ;  jiaraphyses  iudistinctic ;  reactio  amyli 
Bcmper  distiucta,  vulgo  iutensa. 

•  S.e  '  EnRl.  Mccli.,'  xxxi.  (1880)  p.  492. 
t  '  bet.  Zcit..'  xxxviii.  (1880)  p.  343. 

X  'Koiirrl.  Svenskii  Vetenak-Akart.,'  xvii.  (18S0)  p.  1.  See  '  Uut.  Ceutralbl.,' 
i.  (is.lO)  p.  355. 


842  RECOKD   OF    CURRENT    RESEARCHES   RELATING   TO 

In  accordance  with  Schwendener's  well-known  theory,  tlie  author 
regards  the  genus  as  belonging,  like  other  lichens,  to  the  Asco- 
niycetes.  Were  the  gonidia  to  be  regarded  as  special  organs, 
the  following  improbable  results  would  ensue  :  (1)  Very  nearly 
related  species,  like  A.  granitojpldla  and  neglectula,  and  even  difl'erent 
forms  of  the  same  species,  as  A.  mediella,  would  have  diiferent 
organs  of  assimilation,  differing  greatly  from  one  another,  and  with- 
out any  transitional  forms.  (2)  Very  nearly  related  species,  as 
A.  spectcibilis  and  subastroidea,  and  even  different  forms  of  the  same 
species,  like  A.  radiata,  would  differ  in  some  of  them  possessing,  while 
others  were  altogether  without,  organs  of  assimilation.  (3)  Both  the 
liyphfB  and  the  gonidia  and  cortical  cells  would  present  no  difference, 
whether  Arilwnia  was  autonomous,  or  whether  it  derived  its  nutri- 
ment from  the  cortical  cells.  (4)  The  structure  of  the  thallus  would 
be  the  same,  whether  Arfhonia  had  gonidia,  or  whether  it  made  use  of 
the  gonidia  of  other  lichens. 

The  absence  of  gonidia  is  no  sufficient  reason  for  excluding  a 
plant  from  the  group  of  lichens.  The  gonidia  of  the  same  or  of 
allied  species  are  cither  Palmellacefe  or  Chroolepida3 ;  the  gonidia  of 
two  species  are  often  intermixed.  The  gonidia  not  uufrequently  owe 
their  origin  to  the  thallus  of  other  lichens  ;  for  example,  those  of 
A.  pliceohcea  to  Verrucaria  ceutocarpa.  Soredia  occur  in  some  species. 
In  A.  fusispora  there  are  apothecia-like  structures,  which  the  author 
is  inclined  to  regard  as  soredia. 

The  genus  is  divided  into  seven  sections :  viz.  Coniangium,  Coni- 
oloma,  Pacnolepia,  Trachylia,  Euarthonia,  Nsevia,  and  Lecideopsis, 
the  last  of  which  is  new,  and  includes  the  new  species,  A.  amylospora, 
vagans,  intecta,  and  oxijsjjora. 

Algae. 

Algal  Vegetation  of  the  Siberian  Sea-coast.*— In  spite  of  his 
conviction  expressed  in  1876  that  no  new  forms  would  be  added  to 
the  known  Algfe  of  the  Siberian  part  of  the  Arctic  Ocean,  F.  R.  Kjell- 
mann  is  able  to  identify  from  Baron  Maydell's  description  three  species 
from  Tschaun  Bay  as  belonging  to  the  genera  Alaria  and  Laminaria  ; 
they  were  observed  in  the  Russian  Geographical  Society's  Expedition 
of  1869. 

The  results  obtained  in  Professor  Nordenskiold's  expedition  show 
that  an  algal  flora  appears  at  various  points  at  a  distance  from  the 
coast,  as  well  as  in  the  sublittoral  regions ;  only  two  of  the  former 
localities  show  a  jDoor  list  of  species,  and  here  these  are  confined 
to  Lithothamnion  pohjmorplmm,  Phyllophora  interrupta,  and  Lithoderma 
fatiscens.  Two  shore  stations  furnished  only  two  species,  which 
were  an  Enteromorpha  and  a  Urospora.  Fucacese  do  not  occur 
at  all  in  the  littoral  region,  and  only  one,  Fucus  evanescens,  was 
met  with  in  the  eastern  part  of  the  Arctic  Ocean,  and  has  a 
wide  though  scanty  distribution  in  the  western  part.  The  richest 
localities  were  the  so-called  North  Cape  (lat.  68°  55'  N.,  long. 
179°  25'  W.),  and  the  mouth  of  the  Koljuschin  Gulf.      The  most 

*  '  Oefv.  K.  Vet.  Akad.  Forb."  (Stockholm),  xxxvi.  (1880)  p.  23. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  843 

common  species  are  Poli/siphonia  arctica,  Rhoclomela  tenuissima,  a 
form  of  B.  suhfusca,  Sarcophyllis  arctica^  Phyllophora  interrupta,  SpJia- 
celarla  arctica,  aud  Pldoeospora  tortilis. 

In  all,  Floridece  are  represented  by  12  species,  Fucoidece  by  16, 
Cldorophylhiphjceai  by  6,  Plujcochromophjcece  by  1,  in  the  material 
examined  by  Kjellmann. 

Algse  of  the  Utah  Salt  Lake.*— Dr.  A.  S.  Packard,  jun.,  has 
examined  some  of  the  "  seaweeds  "  of  the  Great  Salt  Lake  which  are 
probably  almost  the  only  source  of  food  for  the  brine-shrimp,  as  they 
are  diffused  through  the  water  in  nearly  equal  abundance  with  the 
crustaceans  themselves,  and  do  not  appear  to  grow  attached  to  any 
objects  in  the  lake  or  on  the  shore.  The  most  common  form  is  a 
rounded  mass  which  lives  suspended  in  the  water. 

Professor  W.  G.  Farlow,  of  Harvard  University,  soaked  out  and 
examined  the  dried  material,  which  he  found  to  consist  largely  of 
grains  of  sand  and  remains  of  small  animals,  mixed  with  which  were 
three  species  of  Algfe.  The  most  abundant  was  one  forming  irregular 
gelatinous  masses,  sometimes  attaining  a  diameter  of  half  an  inch. 
The  colour,  apparently  much  faded  in  drying,  was  brownish  with  a 
tinge  of  bluish  greeu,t  and  he  considered  it  to  be  a  new  species  of 
Pohjcystis — P.  PacJcardii.  Its  distinguishing  characters  are  the  oblong 
shape  of  its  cells,  which  are  smaller  than  in  any  of  the  marine  species 
of  the  genus,  and  the  firmness  and  lubulated  form  of  the  gelatinous 
substance  in  which  they  are  embedded. 

There  was  also  a  species  of  Ulva  (using  the  word  in  the  extended 
sense  adopted  by  Le  Jolis)  in  fragments,  so  that  no  very  accurate 
idea  of  its  habit  could  be  formed.  The  microscopic  characters,  how- 
ever, showed  that  it  was,  with  scarcely  any  doubt,  Ulva  marginata  Ag., 
fouud  on  the  coast  of  Europe.  The  specimens  agreed  very  well  with 
those  from  the  French  coast,  considered  by  Le  Jolis  to  be  the  sijccies 
described  by  Agardh. 

The  third  Alga  was  much  less  abundant  than  the  others,  and  was 
in  ]i0()r  condition  for  comparison  with  herbarium  specimens.  It  was 
a  Ilhizuclonium,  coming  very  near  to  P.  salinum  Ktz.  (R.  riparium 
Harv.),  a  common  marine  species  of  America,  and  also  found  in 
Europe  near  salt  springs.  The  Salt  Lake  plant  has  smaller  cells  and 
api)roachcs  P.  Kochianum,  a  species  also  marine  and  found  in  saline 
regions. 

Professor  Farlow  adds  that  "as  a  rule,  the  Algfc  found  in  saline 
regions  belong  to  species  found  in  brackish  waters  on  the  coast.  One 
might  exj)cct  to  find  a  large  variety  of  Ulvcno  and  Confervca;  in  Salt 
Lake,  and  it  would  bo  of  interest  to  sec  how  closely  these  inland 
forms  approximate  to  the  littoral  forms  of  the  eastern  aud  western 
coasts." 

Antherozoids  of  Hildebrandtia  rivularis.t — Sig.  Borzi  describes 
the  nntheridia  of  this  alga,  found  abundantly  in  May  on  smooth  slatc- 

*  '  Am.  Nat.,'  xiii.  (1S7'.»)  p.  701. 

t  Tlic  colour  in  life  i.t  an  olives  groon. 

i  '  Kiviatn  acicntilicn,"  i  (ISSO).     See  '  Dot.  Ceutralbl.,'  i.  (18S0)  p.  481. 


844  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

stones  in  streams  at  Vallombrosa,  near  Florence.  Looked  at  from  the 
surface,  tlic  autheridia-beariug  tliallus  appears  to  be  covered  by  a 
number  of  roundish  or  irregular,  somewhat  elevated,  pale  dots,  con- 
sisting of  a  number  of  densely-crowded  antheridia.  They  are  elon- 
gated cylindrical  cells,  developed  vertically  from  the  apex  of  the 
superficial  cells  of  the  thallus,  twenty  or  more  from  a  single  cell. 
Their  contents  are  at  first  homogeneous,  but  are  subsequently  differ- 
entiated into  seven  or  more  nearly  globular  antherozoids,  placed  in  a 
row  one  above  another,  which  are  set  free  by  the  rupture  of  the  mother- 
cell. 

New  Vaucheria  *  —  M.  Woroniu  describes,  under  the  name 
V,  de  Baryana,  a  new  Vaucheria  collected  by  him  in  streams  near 
Montreux,  on  the  Lake  of  Geneva,  but  also  earlier  by  De  Bary  and 
Peyritsch  near  Halle. 

The  thallus  scarcely  differs  in  any  respect  from  that  of  other 
species  of  the  genus.  The  filaments  are  more  or  less  branched,  usually 
from  0'03  to  0*04  mm.  in  diameter;  the  chlorophyll  is  fine-grained, 
and  of  a  bright  green  colour.  Notwithstanding  this,  the  tufts  of  tbis 
alga  have  a  very  pale  green  or  even  a  grey  tint,  owing  to  their  being 
copiously  encrusted,  when  old,  with  calcium  carbonate,  to  such  an 
extent  that  on  the  death  of  the  filament  the  encrustation  frequently 
remains  behind  in  the  form  of  a  connected  tube.  Tbis  is  not  an 
encrustation  from  without,  but  a  secretion  from  the  substance  of  the 
Vaucheria  itself. 

From  the  thallus  spring  the  fertile  branches,  erect  lateral  sboots, 
0'2-0*3  mm.  in  length,  containing  a  great  quantity  of  oil  and  chloro- 
phyll. The  extremity  of  each  of  these  branches  develops  gradually 
into  an  antheridium.  While  this  is  taking  place,  a  lateral  protuber- 
ance is  formed  on  the  upper  balf  of  the  branch,  which  becomes  a 
stalked  oogonium.  The  development  of  the  two  organs  advances 
pari  passu,  so  that  ultimately  tbeir  orifices  stand  on  the  same  level. 
The  terminal  antheridium  and  stalked  oogonium  determine  V.  de 
Baryana  to  belong  to  Walz's  section,  Vaucherice  racemosce,  but  it  differs 
from  the  other  species  in  the  form  of  the  antheridium.  Instead  of 
being  curved,  with  the  form  of  a  horn  or  hook,  it  has  two  blunt 
lateral  projections,  whicb  give  it  the  appearance  of  tbe  handle  of  a 
crutch ;  the  projections  are,  bowever,  sometimes  three  or  four  in 
number.  The  form  of  the  antheridium  bears  the  nearest  resemblance 
to  those  in  V.  piloholoides  and  sphierospora  ;  but  these  species  belong 
to  a  different  section.  The  orifice  from  whicb  the  antherozoids  escape 
is  always  at  the  end  of  these  protuberances.  The  oogonia  are  spherical 
and  stalked. 

The  process  of  fertilization  takes  place  in  the  same  way  as  in 
other  species  of  the  genus.  The  mature  oospore  is  usually  quite 
spherical,  and  fills  up  the  whole  of  the  oogonium  ;  occasionally  it  is 
beaked. 

Normally  there  is  a  single  superior  antheridium,  and  a  stalked 
oogonium  ;  occasionally  two  antheridia  accompany  a  single  oogonium, 

*  '  Bot.  Zeit.,'  xxxviii.  (1880)  p.  425. 


INVEETEBKATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  845 

or  two  oogouia  a  single  autlieridium,  or  even  two  or  three  oogonia  two 
antheridia.  The  production  of  zoospores  was  not  observed  by 
Woronin.  He  considers  the  new  species  to  be  most  nearly  allied  to 
V.  geminata,  and  believes  that,  like  that  species,  it  may  assume  a 
(row^ros/ra-condition,  and  hence  occur  also  in  an  amoeboid  state. 

Parasitic  Nostoc* — Several  Algte  belonging  to  the  group  of 
Nostochineaj  enter  and  live  in  the  tissues  of  various  terrestrial  or 
aquatic  plants,  and  an  additional  instance  of  this  has  just  been 
observed  by  M.  L.  Marchaud,  which  he  reports  on  account  of  its 
singularity. 

He  collected  on  the  edge  of  a  ditch  near  Montmorency,  some 
small  flask-shaped  bodies,  of  a  blackish-green  colour,  ovoid,  cylin- 
drical or  like  commas,  from  •  1  to  1  •  5  mm.  in  height,  which  were  fixed 
to  the  ground  by  branched  radicular  filaments.  They  vegetated  on 
the  damp  soil  intermixed  with  numerous  specimens  of  Pottia  (Gijmno- 
stomum  triincatuliun),  Anthoceras  levels,  JRiccia  glauca,  Jungermannia 
tenuis,  &c.,  and  in  some  places  covered  the  ground.  They  are  repro- 
duced each  year,  disappearing  in  winter  to  reappear  in  the  spring. 

These  seemed  at  first  to  be  young  individuals  of  Botrydium 
granulatum  ;  but  when  examined  under  the  Microscope  they  presented 
an  entirely  unusual  character.  Instead  of  being  lined  with  a  layer 
of  granular  chlorophyll,  the  interior  of  the  ampulla  was  lined  with 
a  network  of  moniliform  filaments  presenting  all  the  characters  of 
chajilets  of  Nostoc  or  Anahcena. 

The  author  discusses  the  probable  nature  of  these  singular  bodies, 
which,  though  further  examination  is  yet  required,  he  is  inclined  to 
believe  are  due  to  one  of  the  Nostochineaj  (Anahcena  ov  Nostoc),  which, 
having  penetrated  into  the  radicular  filaments  of  a  moss  or  Hepatica, 
and  there  developing,  cause  a  considerable  local  swelling  of  the 
neighbouring  wall. 

Movement  of  the  Cell-contents  of  Closterium  lunula. f — Mr. 
A.  W.  Wills  jioiiits  out  that  at  each  cud  of  the  fronds  of  certain 
Desmidiea3  there  is  a  clear  oval  or  spherical  sjmcc,  within  which  arc 
seen  a  number  cf  minute  particles  in  more  or  less  active  motion,  at 
any  rate  during  some  periods  of  the  life  of  the  plant.  This  is 
especially  the  case  in  the  genus  Closterium,  and  conspicuously  so  in 
the  largest  species,  Closterium  liinuJa. 

In  this  plant  tlierc  is  also,  as  lias  been  often  observed,  a  certain 
motion  of  the  colourless  granular  liquid  cell-contents  which  form  a 
thin  film  between  tlie  deep-green  eudochrome  mass  and  the  cell-wall 
of  the  frond.  This  motion  has  been  described  as  a  circulation,  but 
the  term  is  incorrect.  The  actual  character  of  the  movement  is  ono 
of  ebb  and  flow,  alternately  towards  and  from  the  ends,  and,  in 
favourable  specimens,  careful  examination  under  a  ;J  or  ,1  objective 
shows  tliat  it  takes  place  in  delicate  longitudinal  lines  or  bands,  and 
that  in  different  lines  the  flow  may  be  actually  in  02)posite  directions 
at  the  same  time,  while  in  any  one  lino  the  direction  of  flow  is  usually 

♦  '  Hull.  Soo.  Bot.  Fninoo,"  xxvi.  (1870)  p.  336. 
t  'Mull.  Nat.,'  iii.  (1H80)  j),  IsT. 


846  RECORD    OF   CURRENT   RESEARCHES   RELATING    TO 

reversed  every  few  seconds,  a  moment  of  rest  or  of  confused  move- 
ment of  the  particles  among  one  another  preceding  the  reversal  of  the 
direction. 

The  cause  of  this  peculiar  ebb  and  flow  has  not,  he  believes,  been 
previously  recorded. 

The  clear  spaces  at  the  ends  of  the  fronds  of  the  Closterium  are 
really  contractile  vesicles,  and  careful  observation  under  the  above 
powers  shows  that  they  are  undergoing  incessant  though  slight  change 
of  form.  The  contraction  of  any  part  of  the  surface  of  the  vesicle  is 
followed  by  an  immediate  rush  of  the  surrounding  fluid  to  fill  the 
vacuum  thus  formed,  and  the  direction  of  the  currents,  where  the 
transparent  spaces  allow  them  to  be  observed,  may  be  clearly  con- 
nected with  the  corresponding  contraction  of  one  or  other  part  of  the 
vesicle.  In  stating  their  flow  to  be  in  lines  or  bands,  it  is  merely 
intended  to  describe  the  general  appearance  of  the  action.  The  whole 
space  between  the  endochrome  and  the  cell-wall  is,  doubtless,  filled 
with  the  fluid ;  but  the  transverse  section  of  the  former  would  pro- 
bably present  a  fluted  or  corrugated  form,  corresponding  to  its  longi- 
tudinal disposition  in  belts  of  denser  matter ;  and  the  flow  of  the 
surrounding  fluid  may  probably  be  determined  by  the  channels  formed 
by  this  fluted  structure. 

These  movements  may  be  found  to  have  their  parallel  in  the 
smaller  species  of  Closterium,  and  in  other  genera  of  Desmidieaa  in 
which  there  is  a  terminal  vesicle. 

It  is  to  be  noted  that  the  flow  of  cell-contents,  while  it  is 
actuated  by  the  contractile  motions  of  the  vesicle,  is  a  phenomenon 
wholly  distinct  from  the  swarming  of  the  larger  particles  within  it, 
the  functions  of  which  are,  Mr.  Wills  fears,  still  hidden  in  entire 
obscurity. 

Endochrome  of  Diatomacese.*  —  A  writer  in  the  '  English 
Mechanic,'  referring  to  M.  Petit's  paper,  of  which  we  gave  a  trans- 
lation at  p.  680,  says,  "  The  English  student  of  the  chromatology  of 
plants  will  not  fail  to  be  surprised,  on  reading  M.  Petit's  article,  to 
find  no  reference  to  the  valuable  work  done  by  Mr.  Sorby  in  this 
department  of  scientific  research,  and  we  can  only  come  to  the  con- 
clusion that  M.  Petit  is,  as  so  many  of  his  countrymen  appear  to  be, 
extremely  ignorant  of  the  present  position  of  vegetable  and  animal 
chromatology  in  England.  This  is  very  much  to  be  regretted,  as 
there  is  no  doubt  that  had  M.  Petit  been  familiar  with  the  valuable 
paper  read  by  Mr.  Sorby  before  the  Eoyal  Society  in  1873,  and 
published  in  the  '  Proceedings '  of  the  Eoyal  Society  in  that  year,-j- 
his  conclusions  would  have  been  much  modified,  and  the  ground 
covered  in  his  research  not  only  greatly  extended,  but  more  minutely 
examined.  There  is  no  doubt,  for  instance,  that  M,  Petit  would 
have  foimd  reason  to  believe  that  his  phycoxanthine  is  identical  with 
that  of  Kraus,  and,  as  Mr.  Sorby  has  shown,  is  really  a  '  mixture  of 
two  or  three  distinct  colouring  matters,  which  can  easily  be  separated 
and  do  occur  separately  in  other  plants.'     The  true  phycoxanthine 

*  '  Engl.  Mech.,'  xxxi.  (1880)  p.  573.  t  No.  146,  vol.  xxi. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  847 

of  Sorby  gradually  fades  on  the  addition  of  hydrochloric  acid  and 

turpentine The  writer  has  no  doubt  (taking  his  stand  almost 

entirely  upon  the  charts  in  M.  Petit's  jiaper)  that  the  so-called 
phycoxantliine,  in  the  condition  in  which  M.  Petit  examines  it,  con- 
sists of  the  yellow  xauthophyll  of  Sorby,  with  a  slight  admixture  of 
chlorofucine,  true  fucoxanthine,  and  lichnoxanthine,  with  contamina- 
tion by  imperfect  separation  of  the  chlorophyll,  which  is  itself  com- 
pound, and  a  very  little  of  true  phycoxanthine.  But  whilst  we  are 
compelled  to  regret  that  M.  Petit's  work  is  incomplete,  we  express 
our  thanks  to  him  for  having  opened  up  a  new  field  of  inquiry  for 
our  diatom  friends." 


MICKOSCOPY,   &c. 


Microscopical  Analysis  of  Water.* — M.  Certes  observes  that 
recourse  must  bo  had  to  the  Microscope  in  order  to  discover  the  nature 
of  the  minute  organisms  of  water,  whether  badly  infested  by  them  or 
not.  The  great  difficulty  of  discovering  these  bodies  in  pure  waters  is 
best  overcome  by  the  use  of  osmic  acid,  which  also  at  once  kills  and 
preserves  them. 

An  experiment  which  shows  the  efficacy  of  his  method  is  to  place 
30  c.c.  of  distilled  water  in  each  of  two  tubes,  and  in  one  of  them  to 
agitate  a  glass  tube  which  has  been  dijjped  in  water  infested  with 
microscopic  organisms;  to  the  contents  of  both  tubes  equal  amounts 
of  osmic  acid  are  added.  In  examining  the  water  with  the  Microscope 
while  the  one  sample  shows  nothing  organized,  in  the  one  into  which 
the  rod  was  dipped  even  the  few  dead  Infusoria  are  to  be  found. 

In  a  drinking  water,  containing  but  little  organic  matter,  a  solution 
of  osmic  acid  of  the  strength  of  1  •  5  per  100  is  used,  and  1  c.c.  of  this 
is  added  to  30  or  40  c.c.  of  the  water ;  after  some  minutes  as  much 
more  distilled  water  is  added  as  the  vessel  will  contain  (in  order  to 
check  the  action  of  the  acid).  The  length  of  time  after  this  at  which 
tlie  mixture  may  be  examined  varies  from  a  few  hours  in  the  case  of  a 
highly  imj)uro  liquid  to  from  twenty-four  to  twenty-eight  for  a  very 
pure  one;  at  the  cud  of  the  time  it  must  be  decanted  with  great  caro, 
80  as  to  leave  the  precipitate  in  from  1  to  2  c.c.  of  liquid. 

The  use  of  staining  materials  has  some  advantages ;  among  the  best 
of  these  materials,  M.  Certes  considers  are  Ranvier's  picrocarmiuo, 
methyl  green,  eosiu,  haimatoxylin.  Paris  violet  has  the  recommenda- 
tion of  deeply  staining  minute  and  transparent  objects ;  it  should  bo 
very  dilute  ;  it  then  colours  cellulose  blue,  amyloid  matters  red,  and 
gives  a  bluish-violet  tint  to  cilia,  flagella,  and  the  protoplasm  of 
Infusoria.  Whatever  staining  matter  is  used,  it  is  advisable  to  mix 
some  dilute  glycerine  with  it  previously  to  use,  care  being  taken  not 
to  allow  the  organisms  to  be  shrivelled  by  too  rapid  action  of  tho 
glycerine  of  the  mixture ;  they  arc  thus  kept  transparent,  and  may 
bo  preserved  well  in  tlie  glycerine. 

♦  '  Coinptca  RenduH,'  xc.  (18S0)  p.  1 135. 


848  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

It  is  probable  that  the  method  may  bo  well  employed  in  examining 
the  tissues  and  liquids  of  animals  for  parasites.  The  author  has  thus 
treated  the  Anurous  Batrachia. 

On  this  subject  it  may  be  also  noted  that  Professor  Huxley  has 
recently  thrown  some  doubt  on  the  conclusions  arrived  at  by  chemists 
in  determining  the  wholesomeness  of  water.  Organic  matter  may  be 
either  of  animal  or  vegetable  origin,  the  former  being  dangerous,  and 
the  latter  much  less  so,  if  not  altogether  innocuous.  To  distinguish 
between  the  two  kinds  is  therefore  all-important,  but  unfortunately  it 
is  impossible  directly  to  do  this,  as  both  animals  and  j)lants  yield 
albuminoid  matters,  which,  chemically  speaking,  are  practically 
identical  in  composition.  None  of  the  processes  in  use  by  chemists 
can  be  relied  upon  as  giving  any  indication  of  the  nature  of  the  organic 
matter,  i.  e.  whether  it  is  dangerous  or  not,  and  yet  it  is  the  almost 
invariable  custom  to  judge  of  a  water  by  the  quantity  of  organic 
matter  it  contains,  no  matter  what  its  origin,  and  a  variation  of  two  or 
three  times  a  given  amount  is  held  to  make  the  difference  between  a 
good  and  bad  water. 

It  was  to  this  point  that  Professor  Huxley  especially  addressed 
himself  at  a  meeting  of  the  Chemical  Society,  and  gave  it  as  his 
opinion,  speaking  as  a  biologist,  "  that  a  water  may  be  as  pure  as  can  be 
as  regards  chemical  analysis,  and  yet  as  regards  the  human  body  be  as 
deadly  as  prussic  acid,  and,  on  the  other  hand,  may  be  chemically 
gross,  and  yet  do  no  harm  to  any  one."  "  I  am  aware,"  he  said,  "  that 
chemists  may  consider  this  as  a  terrible  conclusion,  but  it  is  true,  and 
if  the  public  are  guided  by  percentages  alone,  they  may  often  be  led 
astray.  The  real  value  of  a  determination  of  the  quantity  of  organic 
impurity  in  a  water  is  that  by  it  a  very  shrewd  notion  can  be  obtained 
as  to  what  has  had  access  to  that  water." 

Mr.  C.  Ekin,  commenting  *  upon  these  statements,  says  that  since 
chemical  analysis  fails  entirely  to  distinguish  between  innocuous  and 
deadly  kinds  of  matter,  it  may  bo  thought  a  work  of  supererogation  to 
have  recourse  to  it  at  all.  What,  however,  analysis  fails  to  do  directly 
it  can  to  a  large  extent  do  indirectly.  Organic  matter  in  solution  in 
water  is  more  or  less  prone  to  oxidation,  the  highly  putrescible  matter 
of  sewage  being  most  so,  and  that  derived  from  vegetation  being  much 
less  so.  Hence  it  follows  that  one  would  expect  to  find  the  oxidized 
nitrogen  compounds  in  a  greater  excess  in  the  one  case  than  in  the 
other,  and  that  is  what  we  do  find.  Almost  invariably  in  all  waters  of 
acknowledged  wholesomeness  the  quantity  of  nitrates  never  exceeds  a 
certain  small  amount,  whereas  in  polluted  well  and  spring  waters  the 
oxidized  nitrogen  compounds,  with  other  accompaniments  of  sewage, 
are  to  be  found  in  excess.  By  means,  then,  of  these  oxidized  nitrogen 
compounds  we  get  collateral  evidence  throwing  light  on  the  nature 
and  probable  source  of  the  contamination,  of  which  a  mere  percentage 
estimation  of  organic  matter  would  fail  to  give  the  slightest  indi- 
cation. 

The  mistake  has  been  hitherto  that  the  discussion  has  been 
narrowed  by  looking  at  the  question  almost  entirely  from  a  chemist's 
*  See  '  Nature,'  xxii.  (1880)  p.  222. 


INVERTEBRATA.    CRYPTOGAMIA,    MICROSCOPY,    ETC.  849 

point  of  view.  It  is,  however,  to  tbe  biologist  that  we  must  look 
chiefly  for  the  future  elucidation  of  the  subject,  and  he  has  a  field  of 
the  widest  range,  embracing  much  untrodden  ground,  for  his  investi- 
gations. 

Browuian  Movement. — ^Similar  motions  to  those  shown  under  the 
Microscope  by  small  particles  in  liquids  have  been  attributed  to  dust- 
particles  in  air,  and  accounted  for  by  the  shock  of  molecules  with  the 
particles. 

In  a  paper  treating  fully  of  the  movements  of  very  minute  bodies,* 
Herr  Niigeli  calculates  (from  data  of  the  mechanical  theory  of  gases 
as  to  the  weight  and  number,  and  collisions  of  molecules)  the  velocity 
of  the  smallest  fungus-particles  in  the  air  that  can  be  perceived  with 
the  best  instrument,  supposing  a  nitrogen  or  oxygen  molecule  to  drive 
against  them.  It  is,  at  the  most,  as  much  as  the  velocity  of  the  hour- 
hand  of  a  watch,  since  these  fungi  are  300  million  times  heavier 
than  a  nitrogen  or  oxygen  molecule.  The  ordinary  motes  would 
move  50  million  times  slower  than  the  hour-hand  of  a  watch.  Numbers 
of  the  same  magnitude  are  obtained  for  movements  of  small  jiarticles 
in  liquids.  In  both  cases  a  summation  of  the  shocks  of  different 
molecules  is  not  admissible,  as  the  movements  ai'c  equally  distributed 
in  all  directions. 

Niigeli  therefore  disputes  the  dancing  motion  of  solar  dust-particles, 
and  attributes  the  Browniau  molecular  motion  to  forces  active  between 
the  surface  molecules  of  the  liquid  and  the  small  particles ;  but  he 
does  not  say  how  he  conceives  of  this  action.f 

Examining  very  soft  Rocks. — The  following  process  of  preparing 
sections  of  very  soft  and  friable  rocks  is  communicated  J  by  Mr.  J.  A. 
Phillips  to  Mr.  F.  Rutley.  The  chip,  which  may  be  to  some  extent 
hardened  by  saturation  in  a  mixture  of  balsam  and  benzol  until 
thoroughly  impregnated  with  it,  and  afterwards  dried,  should  be 
gently  ground  or  filed  down  until  a  smooth,  even  surface  is  i)rocured ; 
this  surface  must  then  be  attached  to  a  piece  of  glass  slide  cut  about 
an  inch  square,  and  this  again  fixed  in  a  similar  manner  by  old  balsam 
to  a  thicker  piece  of  glass  if  needful,  so  that  it  can  be  conveniently 
lield  whilst  the  grinding  is  carried  on.  When  it  is  reduced  to  such  a 
degree  of  tenuity  that  it  will  bear  no  more  grinding,  even  with  the  finest 
materials,  such  as  jewellers'  rouge,  and  when  the  removal  of  the  section 
from  the  glass  to  which  it  is  attached  would  almost  inevitably  result 
in  the  destruction  of  the  preparation,  the  lower  i)iece  of  glass  should 
be  warmed  and  separated  fi'om  tlic  ujjper  jjiecc  wliich  bears  the  section, 
and  this,  with  its  attached  section,  should  be  again  cemented  by  the 
under  side  of  the  glass  to  an  ordinary  glass  slip,  covered  in  the  usual 
way,  and  if  the  edges  of  the  section,  or  its  glass,  be  disfigured  by 
grinding,  a  ring  or  square  margin  of  lh-uns\vick  black  or  asphalt  may 
be  painted  over  the  unsightly  j)iirt. 

*  'SB.  K.  Bay.  Akad.  Wi.s.^.,'  ISTD.  p.  HSO. 
t  Sfu  '  Natuiv,'  xxi.  (ISSii)  |>.  :i.")L». 

I  V.  Hiitl.y'.-,  'Stii'ly  <>(  UcM-k, '  (Sv,,.  London.  1S7'.»).  |'   70. 
VOL.    III.  3    K 


850  RECOBD   OF    CURRENT    RESEARCHES   RELATING   TO 

Mr.  Eutley  laimself  says  :  * — In  the  case  of  very  soft  rocks,  such 
as  tuffs,  clays,  &c.,  useful  information  may  sometimes  be  acquired 
by  washing  to  pieces  fragments  of  the  rock ;  in  this  way  a  fine  mud 
and  often  numerous  minute  crystals  and  organisms  may  be  procured. 
The  best  aj^paratus  for  effecting  this  gradual  washing  is  a  conical 
glass  about  9  or  10  inches  high,  across  the  mouth  of  which  a  cross- 
bar of  metal  or  wood  is  fixed.  A  little  hole  drilled  in  the  centre  of 
the  bar  receives  the  tube  of  a  small  thistle-headed  glass  funnel. 
Roughly  broken  fragments  of  the  rock  should  be  placed  in  the 
bottom  of  the  conical  glass,  and  the  apparatus  set  beneath  a  tap, 
from  which  a  stream  of  water  is  continually  allowed  to  run  into  the 
mouth  of  the  funnel,  the  overflow  trickling  down  the  sides  of  the 
glass,  which  should  consequently  be  placed  in  a  sink.  In  this 
manner  a  constant  current  is  kept  up,  and  the  fragments  at  the 
bottom  of  the  glass  are  continually  turned  over,  agitated,  rubbed 
against  one  another,  and  gradually  disintegrated.  This  action  should 
be  kept  up,  often  for  many  days,  until  a  considerable  amount  of  dis- 
integrated matter  has  accumulated.  Samples  should  then  be  taken 
out  by  means  of  a  pipette  and  examined  under  the  Microscope. 

When  the  observer  wishes  to  mount  either  such  materials  or  fine 
scaly,  powdery,  or  minutely  crystallized  minerals,  the  best  method  is 
to  spread  a  little  of  the  substance  on  a  glass  slide,  moisten  the  powder 
with  a  drop  of  turpentine,  and  then  add  a  droj)  of  Canada  balsam,  and 
cover  in  the  usual  manner.  If  the  attempt  be  made  to  mount 
such  substances  directly  in  balsam,  without  the  intervention  of 
turpentine  or  some  kindred  medium,  air-bubbles  are  almost  certain  to 
be  included  in  the  preparation. 

Lenses  for  Petrographical  Work. — Mr.  Melville  Attwood,  in  a 
paper  read  before  the  San  Francisco  Microscopical  Society,  quotes  the 
following  passage  from  Mr.  Frank  Eutley's  book  on  '  The  Study  of 
Eocks'  t :  "  There  is,  however,  a  disadvantage  attending  the  use  of  lenses 
when  they  are  applied  to  the  examination  of  rocks.  This  lies  in  the 
difficulty  experienced  by  the  observer  when  he  attempts  to  examine 
the  streak  of  minerals  under  the  lens,  especially  when  the  minerals 
occur  in  very  minute  crystals  or  patches,  as  it  is  scarcely  possible  to 
■hold  a  specimen,  with  a  lens  over  it  in  focus,  in  one  baud,  and  to 
Ivork  with  a  knife  in  the  other.  Laying  the  specimen  on  a  table, 
and  using  a  lens  in  one  hand  and  a  knife  in  the  other,  is  a  most 
Unsatisfactory  process  ;  while  the  use  of  a  lens  fixed  on  an  adjusting 
stand  is  scarcely  better.  To  obviate  this  difficulty,  the  author  has 
devised  a  small  lens  with  a  clip,  which  can  be  worn  on  the  nose  like 
an  eye-glass,  and  both  hands  are  then  at  liberty — the  one  to  hold  the 
fepecimen  firmly,  the  other  to  use  the  knife  or  graver.  This  clip-lens 
is  moreover  better  than  a  watchmaker's  eye-glass,  because  it  entails 
no  muscular  effort  to  keep  it  in  place.  It  is  better  to  have  the  lens 
mounted  in  a  horn  than  in  a  metal  rim  as  it  is  less  heavy  and  con- 
sequently less  liable  to  be  accidentally  shifted  or  displaced  by  the 
inclination  of  the  head." 

*  F.  Rutley's  '  Study  of  Eocks^',(Svo,  London,  1S79),  p.  73. 
t  Il'id.,  p.  44. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


851 


Mr.  Attwood  adds  that  instead  of  a  clip-lens  he  uses  a  watch- 
maker's eye-glass,  fixed  with  a  screw  into  a  light  pair  of  steel 
sjiectacle  frames,  which  he  thinks  the  botanist,  also,  will  find  a  very 
useful  arrangement.  This  suggestion  was,  however,  anticipated  by 
the  late  Robert  Brown,  whose  set  of  spectacles  were  some  years 
since  (1874)  presented  to  the  Society  by  Dr.  Gray.     Fig.  75  shows 

Fig.  75. 


one  of  the  spectacle  frames  fitted  with  two  double-convex  lenses 
in  a  short  brass  tube  forming  a  doublet ;  one  lens  being  broken,  the 
focus  cannot  now  be  determined.  Fig.  76  shows  another  arrangement 
which  allows  the  magnifier  to  be  turned  aside  when  it  is  desired  to 

Fig.  76. 


use  the  naked  eye.  Two  other  pairs  of  spectacles  also  accompanied 
the  preceding,  with  lenses  of  about  3  inch  and  4  inch  focus,  tho  lens  in 
one  unscrewing. 

Process  for  Microscopical  Study  of  very  minute  Crystalline 
Grains.* — M.  J.  Thoulct" imbeds  the  particles  of  mineral  in  a  cement 
which,  when  set,  he  slices  and  polishes  for  microscoitical  examination. 
Tho  mineral  powder  to  be  examined  is  mixed  with  ten  times  its 
volume  of  oxide  of  zinc,  and  enough  silicate  of  soda  (or  preferably,  of 
potasli)  is  added  to  make  a  thick  paste.  This  paste  is  then  transferred 
to  a  niouM,  made  by  laying  a  thin  ring  of  ghiss  upon  a  sheet  of  paper. 
*  '  Bull.  SfK-..  Mill.  Fninri>,'  ii.  (1880)  p.  7. 

3  K  2 


852 


RECORD    0!f   current    RESEARCHES   RELATING    TO 


In  a  few  days  the  mass  will  have  set  hard,  and  can  be  removed  from 
the  mould,  ground,  and  polished  like  a  natural  rock,  as  it  possesses 
great  tenacity.  On  examination  under  the  Microscope,  the  sections 
of  mineral  that  it  contains  are  easily  distinguished  in  the  midst  of 
the  surrounding  opaque  material. 

Dr.  Matthews's  Machine  for  Cutting  Hard  Sections.— In  the 
previous  volume  *  we  gave  a  preliminary  account  of  this  machine, 
and  now  add  the  full  description,  with  woodcuts.  Fig.  77  being  a  plan 
view,  and  Fig.  78  a  side  elevation. 

Fig.  77. 


Fig.  78. 


The  metal  stage-plate  A  is  supported  upon  four  pillars  B  B,  and 
is  mounted  upon  a  base-board  C.     On  the  upper  side  of  the  stage  A 

*  See  tliis  Journal,  ii.  (1870)  p.  957. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  853 

are  four  vertical  pivots  d,  iiiDon  wliich  are  fitted,  so  as  to  turn  freely 
thereon,  tlie  four  flanged  rollers  D  D  and  D'  D'.  In  front  of  tlio 
rollers  D  is  fitted  a  flat  metal  plate  E,  and  at  the  back  of  the  rollers 
D'  is  similarly  fitted  a  flat  strip  of  wood  F,  the  side  of  the  strip 
bearing  against  the  rollers  being  provided  with  a  lining  of  india- 
rubber.  The  plate  E  and  the  strip  F  are  secured  together  by  means 
of  the  transverse  tie  bolt  G  and  the  clamp  H,  thus  forming  a  kind  of 
rectangular  frame,  capable  of  traversing  freely  to  and  fro  on  the 
rollers  D  and  D'.  At  the  end  of  the  stage-plate  A  is  mounted  in 
suitable  bearings  a  crank-shaft  I,  fitted  with  a  flywheel  I*  and  a 
winch-handle  J.  This  crank  is  connected  by  the  rod  K  to  the  bolt 
G  of  the  rectangular  frame  E  F.  In  front  of  the  plate  E  are  secured 
the  metal  bars  L  and  L'.  The  bar  L  is  slotted,  and  is  secured  by 
two  screws,  so  as  to  be  capable  of  adjustment  vertically  by  means  of 
the  screw  I.  The  bar  L'  is  pivoted  to  the  plate  by  one  screw,  so  as 
to  admit  of  adjustment  laterally  by  means  of  the  screw  I'.  A  fine 
saw  web  m  is  clamped  by  its  ends  to  the  two  bars  L  L'. 

The  saw  being  clamped  in  its  place,  the  requisite  tension  can  be 
given  to  it  by  the  screw  l',  while,  by  means  of  the  adjusting  screw  I, 
its  parallelism  can  be  secured.  On  turning  the  crank-shaft  I  by 
means  of  the  winch-handle  J,  a  reciprocating  motion  will  be  imparted 
to  the  frame  E  F  and  to  the  saw  m. 

For  holding  and  imparting  the  reqiaisite  feed  to  the  material  to 
be  cut,  the  following  contrivance  is  adopted  : — Beneath  the  stage- 
plate  A  is  secured  a  tube  M  (shown  detached  in  longitudinal  section 
at  Fig.  79).  Sliding  freely  inside  this  tube  is  a  solid  cylinder  N. 
This  cylinder  is  pressed  by  a  spiral  spring  0  against  a  micrometer 
screw  P.  On  the  upper  side  of  the  cylinder  N  is  secured  by  screws 
a  lever  arm  Q.  This  lever  arm  carries  at  one  end  a  counterpoise 
weight  E,  and  is  furnished  at  the  other  end  with  a  clamp  and  binding 
screw  S.  The  material  to  be  cut — say  a  piece  of  bone — is  fastened 
by  any  suitable  cement  (such  as  glue)  to  a  slip  of  wood  T,  and  this 
slip  is  clamped,  as  sliown  in  the  figure,  to  the  end  of  the  lever  arm  Q. 
By  turning  the  micrometer  screw  P  the  cylinder  N  will  be  driven 
forward,  carrying  with  it  the  lever  arm  Q  and  the  piece  of  bone  to  be 
cut.  The  counterpoise  R  will  now  cause  the  piece  of  bone  to  bear 
upwards  against  the  teeth  of  the  saw,  and  a  rapid  rccii)rocating 
motion  being  imparted  to  this  latter,  as  already  explained,  a  thin 
slice  will  be  cut  oil".  This  operation  may  be  repeated  imtil  the  whole 
of  the  material  is  cut  up.  The  slices  can  then  be  removed  from  the 
wooden  slip  by  snaking  in  a  little  warm  water. 

A  grooved  pulley  U  is  provided  on  the  crank-shaft  in  order  that 
the  machine  may  be  driven  by  a  flywheel  and  treadle  if  desired,  and 
saws  of  different  degrees  of  fineness  may  be  employed  to  suit  the 
various  materials  required  to  bo  cut.* 

Bleaching  and  Washing  Sections. f — Mr.  S.  Marsh,  jun.,  suggests 
the  direct  action  of  free  chlurinc  for  bkaching  vegetable  tissues  prior 

'  Son  Mourn.  Qiiok.  Mi(  r.  (  liil),'  vi.  (I^SO)  p.  8:5. 
t  Ibi'l.,  i-p.  Tit-?. 


854 


EECOKD   OF   CUKRENT   RESEARCHES   RELATING   TO 


to  staining,  avoiding  the  inconvenience  of  alcohol  which  is  very 
slow  in  action  and  not  always  certain  in  result,  and  solutions  of 
lime  chloride  and  chlorinated  soda  (Labarraque's)  which  so  disinte- 
grate that  many  delicate  tissues  are  utterly  ruined.  The  former 
solution,  in  addition  to  its  direct  destructive  influence,  has  a  great 
tendency  to  permit  of  the  formation  on  its  surface  of  a  scum  of 
carbonate  of  lime  ;  this,  sinking  into  the  fluid,  settles  itself  upon  the 
sections,  so  that  if  they  escape  absolute  destruction  they  are  in 
danger  of  becoming  coated  with  a  brittle  film,  which  proves  equally 
ruinous  to  them. 

The  apparatus  employed  for  the  purpose  is  shown  in  Fig.  80,  and 
consists  of  two  small  wide-necked  (1  oz.)  bottles,  with  a  bent  glass 
(quill)  tube  passing  through  the  centre  of  sound  and  accurately 
fitting  corks  which  are  made  air-tight  by  shellac  varnish.  A  notch 
is  cut  in  the  edge  of  the  cork  carrying  the  longer  arm  of  the  tube. 


Fig.  80. 


Fig.  81. 


^~J 

1_3 

^^ 

\ 

^^^^S^ 

To  use  the  apparatus,  fill  the  bottle  A  three  parts  full  with  filtered 
rain-water,  and  to  this  transfer  the  sections  to  be  bleached.  Into 
bottle  B  put  a  suificient  quantity  of  crystals  of  chlorate  of  potash  just 
to  cover  the  bottom,  and  upon  them  pour  a  drachm  or  so  of  strong 
hydrochloric  acid,  and  fit  in  the  corks.  Immediately  the  yellow 
vapour  of  chlorine  (or,  strictly  speaking,  of  euchlorine)  will  be  ob- 
served to  fill  the  bottle  B,  whence  it  will  pass  along  the  connecting 
tube  into  the  water  contained  in  the  bottle  A,  and  effectually  and 
safely  bleach  the  sections.  When  the  water  becomes  supersaturated, 
the  excess  of  chlorine  will  accumulate  in  the  bottle  above  the  liquid, 
and  find  an  exit  through  the  notch  in  the  cork.  As  to  the  time 
required  for  bleaching,  this  of  coiarse  will  vary  in  accordance  with  the 
nature  of  the  sections  operated  upon.  If  the  apparatus  is  set  to  work 
at  night  (out  of  doors,  in  a  covered  place),  in  the  morning  the  bleach- 
ing is  generally  found  to  be  complete  ;  if  not,  further  time  may  be 
allowed,  without  any  danger  to  the  sections  being  incurred. 

Decoloration  having  been  effected,  the  sections  must  be  thoroughly 
washed  to  eliminate  all  trace  of  chlorine  before  employing  any  stain  - 
ing  agent.  The  usual  method  of  effecting  this  is  to  put  the  sections 
into  a  large  basin  full  of  water,  and  repeatedly  to  change  the  water. 
As  this  process  is  not  only  tedious,  but  exposes  the  sections  to  consider- 


INVERTEBRATAj    CRYPTOGAMIA,    MICROSCOPY,    ETC.  855 

able  risk  of  being  contaminated  with  dust  and  other  extraneous  matter, 
Mr.  Marsh  emi^loys  a  system  of  continuous  washing  (see  Fig.  81^, 
For  this  purpose  a  small  wide-necked  bottle,  as  for  bleaching,  is 
required,  and  into  the  side,  half  an  inch  or  so  below  the  bottom  of  the 
cork,  a  small  hole  about  an  eighth  of  an  inch  in  diameter  is  drilled. 
A  well-fitting  cork  must  be  pierced  through  the  centre,  so  as  to  permit 
the  stem  of  a  small  funnel  to  pass  through  it.  By  means  of  a  small 
indiarubber  tubing,  the  funnel  stem  is  to  bo  prolonged  till  it  reaches 
the  bottom  of  the  bottle  on  the  side  tvhich  is  opposite  to  that  containing 
the  perforation. 

The  bottle  is  then  half  filled  with  filtered  water,  and  the  sections 
put  into  it,  and  the  cork  carrying  the  funnel  fitted  in.  After  having 
placed  a  disk  of  filtering  paper  into  the  funnel,  this  is  put  beneath  the 
water-tap,  and  a  gentle  stream  allowed  to  trickle  into  it.  The  water 
will  pass  to  the  bottom  of  the  bottle,  gradually  ascend,  and  then  pass 
out  at  the  hole  in  the  side,  by  which  means  a  constant  change  in  the 
water  in  the  bottle  is  brought  about,  and  a  system  of  continuousi 
washing  established.  As  in  bleaching,  so  in  washing,  the  apparatus 
may  be  left  to  do  its  work  in  the  night.  If  the  tap  be  set  running  in 
the  evening,  the  washing  will  be  found  to  have  been  most  efiectually 
accomplished  by  the  morning. 

Wickersheimer's  Preservative  Liquid.*  —  Herr  Wickersheimer 
has  been  continually  making  experiments  for  improving  this  liquid,f 
and  has  become  convinced  that  one  and  the  same  mixture  is  not 
suited  for  all  objects  ;  and  he  has  therefore  made  four  different  kinds, 
for  the  application  of  which  the  following  directions  are  given  : — ■ 

No.  1  is  for  injecting  whole  corpses,  including,  when  still  prac- 
ticable, the  injection  of  separate  parts  ;  also  for  immersing  preparations 
of  muscle  and  nerve,  and  generally  for  preserving  such  preparations 
as  easily  become  mouldy.  The  injection  is  effected  by  introducing 
the  fluid  by  a  syringe  with  a  blunt  tube  into  the  carotid  artery,  or  into 
any  large  blood-vessel  in  separate  portions  of  corpses.  For  smaller 
bodies,  lOOgi'ammcsof  the  liquid  should  be  allowed  for  every  kilo,  in 
weight  (if  the  body,  for  larger  ones  1  kilo,  of  liquid  to  25  kilo,  weight. 
For  adult  men  and  large  animals,  it  is  enough  rf  '500  to  'TSO  kilo,  of 
liquid  is  used  to  every  25  kilo,  weight. 

No.  2  is  for  preserving  and  keeping  flexible  the  ligaments  of  the 
skeleton  ;  also  for  preserving  Crustacea,  beetles,  &c.,  and  for  lung. 
The  objects  should  lie  in  the  liquid  from  two  to  six  days,  according  to 
their  size,  and  then  be  put  by  dry.  Lung  must  be  treated  as  follows, 
in  order  to  retain  its  elasticity  permanently.  After  having  first  forced 
out  the  blooil,  the  lung  is  filled  with  the  liquid  by  a  funnel  which  is 
inserted  in  the  windpipe  until  it  is  fully  extended.  Then,  after  tlio 
liquid  has  been  allowed  to  drain  away  again  through  the  windpipe, 
the  lung  is  immediately  treated  several  times  with  the  liquid  on  the 
outside,  and  inflated  ;  it  is  then  advisable  to  rinse  it  once  more  in  u 
mixture  of  one  i)art  of  No.  1  and  one  part  of  glycerine,  and  put  it  in  a 

*  '  Eutt'mr.l.  Naclir.;  vi.  (1880)  p.  12'J. 
t  Soo  tliis  Jounml,  nutr,  pp.  'A'lft  niul  09(J. 


856  RECORD   OF    CURRENT   RESEARCHES    RELATING    TO 

wide  glass  witli  a  close-fitting  wooden  lid,  as  tins  prevents  the  external 
surface  of  the  lung  becoming  dry  in  case  it  is  not  inflated  for  a  long 
time. 

This  is  also  adapted  for  permanently  preserving  plants,  especially 
Algfe,  without  shrivelling  or  the  chlorophyll  changing.  The  experi- 
ments with  plants,  however,  are  not  concluded,  and  Herr  Wickers- 
heimer  hopes  to  make  important  advances.* 

No.  3  is  for  microscopical  objects.  The  process  is  the  same  as 
for  glycerine.  Those  which  are  intended  to  be  prepared  later  should 
be  kept  meantime  in  No.  2.  Although  with  No.  3  excellent  results 
have  already  been  obtained,  experiments  are  not  concluded. 

No.  4  is  for  preserving  and  hardening  brains,  and  for  preserving 
fishes  and  birds  with  their  feathers. 

The  attention  of  anatomists,  &c.,is  called  to  the  fact  that  by  injecting 
2  to  2^  kilo,  of  liquid  No.  1  before  dissecting,  all  possibility  of  blood- 
poisoning  is  prevented,  although  decomposition  may  have  commenced. 
In  those  cases  where  it  is  not  advisable  to  use  No.  1  fluid,  lest  traces 
of  arsenical  poisoning  should  be  effaced,  another  liquid  can  be  em- 
ployed which  is  quite  free  from  poison,  but,  like  No.  1,  renders  blood- 
poisoning  in  dissecting  impossible. 

It  is  not  of  course  remarkable  to  find  it  stated  that  this  liquid  is 
"  not  new,"  and  that  it  was  invented  by  some  one  else  twenty  years 
ago.t 

Preserving  the  Colours  of  Tissues.^ — It  would  undoubtedly  be  a 
great  advantage  if  the  specimens  in  our  anatomical  museums  could 
be  preserved  with  their  original  colours  unaltered ;  but,  unfor- 
tunately, hfemoglobin  and  most  of  the  other  pigments  found  in  the 
tissues  are  dissolved  out  or  destroyed,  to  a  greater  or  less  extent, 
by  all  the  preservative  fluids  which  are  usually  employed.  If  a 
piece  of  fresh  tissue  be  placed  in  commercial  alcohol  it  very  soon 
becomes  bleached,  and  the  fluid  becomes  at  the  same  time  discoloured 
by  solution  of  the  colouring  matters.  Hfemoglobin  is  soluble  in 
almost  every  known  fluid,  with  the  exception  of  absolute  alcohol, 
which,  however,  causes  great  shrinkage  of  the  soft  parts,  and  is, 
moreover,  too  expensive  to  be  very  generally  employed.  Solutions  of 
chloral  hydrate  have  been  used  (and  with  great  advantage  in  many 
cases) ;  but  here  again,  although  the  colouring  matters  are  by  this 
means  retained  unaltered,  they  are  not  thereby  rendered  insoluble, 
and  hence  they  tend  to  pass  out  into  the  fluid,  leaving  the  tissues 
partially  decolorized.  Other  media  have  been  tried,  but  all  have 
a  similar  imperfection.  By  baking  or  otherwise  heating  the  tissues, 
the  pigments  are  so  altered  as  to  be  rendered  insoluble  in  alcohol ; 
but,  in  addition  to  the  tediousness  of  the  process,  the  action  of  alcohol 
is  then  to  turn  them  black  in  the  course  of  time,  and  hence  this 
method  is  but  little  employed,  except  with  the  object  of  demonstrating 
large  extravasation  and  similar  changes. 

*  See.  this  Journal,  anfe,  p.  696. 

t  See  Duncker's  'Zeitschr.  IMikr.  Fleischscliau,'  i.  (1880)  p.  100. 

X  '  Jouru.  Anat,  ami  Phvsici.,'  xiv.  (1880)  p.  511. 


INVERTEBRATA.    CRYPTOGAMIA,    MICROSCOPY,    ETC,  857 

It  is  a  distinguisliing  cliaractcristic  of  hfemoglobin  that,  although 
a  crystalline  body,  it  is  not  difi'usible ;  and  hence  it  occurred  to  Mr. 
H.  Bendall  that  if  specimens  could  be  coated  with  a  transparent 
membrane  of  a  homogeneous  nature,  the  colouring  matters  would  be 
l)rescrved  in  situ.  For  this  purpose  let  a  quantity  of  isinglass  or 
transparent  gelatine  be  taken  and  steeped  in  excess  of  cold  water  for 
twenty-four  hours,  and  then,  after  draining  off  the  supernatant  fluid,  be 
dissolved  by  heating  over  a  water-bath.  The  specimen  is  then  taken, 
and,  after  being  carefully  wiped  to  remove  suiierfluous  moisture, 
is  either  plunged  in  the  liquid  gelatine,  or  brushed  thoroughly  over 
therewith  by  means  of  a  camel's-hair  brush.  After  having  received  a 
uniform  coat,  the  specimen  is  suspended  in  a  cool  and  dry  atmosphere 
for  two  or  three  hours,  until  the  gelatine  has  had  time  not  only  to  set, 
but  to  dry  slightly  on  its  external  surface  ;  it  may  then  be  suspended 
in  a  jar  of  alcohol,  taking  care  that  it  be  not  allowed  to  rub  against 
the  sides  of  the  jar  for  the  first  twenty-four  hours.  The  .alcohol,  by 
its  dehydrating  power,  rapidly  removes  the  excess  of  water  in  the 
gelatine,  and  dries  it  up  to  a  thin  varnish-like,  and  (if  suitable 
gelatine  be  employed)  perfectly  transparent  coat,  through  which  the 
pigments  are  unable  to  pass  out.  The  alcohol  employed  should  not 
be  diluted,  for  if  this  be  done  the  gelatine  remains  soft  and  easily 
comes  oflF. 

By  this  means  the  author  has  been  enabled  to  preserve,  in  an 
almost  unaltered  condition,  portions  of  muscle,  liver,  &c.,  for  over 
four  months  ;  and  not  only  so,  but  more  delicate  graduations  of  colour, 
such  as  arc  seen  in  an  atheromatous  aorta,  for  example,  are  well 
maintained. 

It  is  as  well  to  point  out  that  this  method  is  not  suitable  for  such 
tissues  as  contain  very  much  blood— e.  g.  the  spleen — nor  for  cyanotic 
organs ;  for  in  such  cases  the  blood  pigment  is  carried  to  the  free 
surface,  and  deposited  beneath  the  gelatine  in  a  layer  which  may  be 
so  dense  as  to  give  a  darkened  and  discoloui'cd  appearance  to  the 
specimen.  Nevertheless,  for  most  tissues  the  method  has  hitherto 
yielded  higlily  satisfactory  results,  and  has  the  additional  advantage 
that  the  alcoliol  docs  not  become  muddy  or  discoloured,  and  hence 
does  not  require  to  be  frequently  renewed. 

Staining-fliiid  for  Amyloid  Substance.* — Dr.  Curschmann,  of 
Ilamhurg,  claims  tliat  metliyl  green  lias  a  peculiar  affinity  for  amyloid 
substance,  colouring  it  an  intense  violet.  Surrounding  tissues  that 
have  not  undergone  degeneration  are  stained  grcrn  or  bluish  green. 
The  contrast  is  striking;  tlie  smallest  spot  of  amyloid  disease  can  bo 
readily  discovered.  Methyl  green  also  colours  hyaline  casts  ultra- 
marine blue,  so  in  a  section  of  the  kidney  the  healthy  tissue  would 
appear  green,  liyaline  casts  blue,  and  amyloid  spots  violet.  A  one  per 
cent,  aqueous  solution  is  used,  a  few  minutes'  immersion  being  suffi- 
cient ;  a  more  uniform  coloration  is  produced  by  using  a  more 
dilute  solution  and  immersing  the  section  for  a  longer  time.  Alcohol, 
turpentine,  and  oil   of   cloves  quickly  discharge    the  colour,   hcnco 

»  •  Louisville  Modical  Hornl.l,'  ii.  (1880)  p.  123. 


858  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

specimens  cannot  be  mounted  in   balsam,  but  may  be  mounted  in 
glycerine. 

Carbolic  Acid  for  Mounting. — The  process  described  at  p.  693 
bas  been  received  with  considerable  favour  by  English  microscopists, 
and  we  therefore  print  the  following  paper,  also  from  Victoria,*  which 
contains  a  full  account  of  the  process  by  Mr.  J.  R.  Y.  Goldstein,  the 
Hon.  Secretary  of  the  Microscoj)al  Society  of  Victoria. 

"  The  mounting  of  objects  in  Canada  balsam  by  means  of 
turpentine  has  long  since  been  a  serious  difficulty  to  students,  and  a 
nuisance  even  to  practical  hands.  Turpentine  evaporates  so  slowly 
that  the  hardening  or  baking  and  finishing  of  slides  becomes  a 
serious  obstacle  where  time  is  concerned,  while  the  previous  pre- 
paration of  objects  saturated  by  water  is  exceedingly  troublesome, 
and  a  general  characteristic  of  mossiness  pervades  the  whole  oper- 
ation. 

The  members  of  this  society  have  for  some  years  adopted  with 
advantage  a  method  suggested  by  the  President,  Dr.  Ralph,  in  1874, 
by  which  the  unpleasantness  of  mounting  in  balsam  is  avoided,  and 
the  time  occuined  considerably  shortened.  Now  that  the  process 
has  stood  the  test  of  years  and  has  proved  so  decidedly  beneficial, 
it  is  considered  advisable  to  publish  in  the  Journal  of  the  Society 
a  detailed  description  of  it,  in  order  that  microscopists  generally 
may  know  and  use  what  may  properly  be  called  '  Ralph's  Carbolic 
Process.' 

When  first  calling  attention  to  the  subject  Dr.  Ralph  suggested 
the  use  of  glycerine  as  a  means  of  withdrawing  water  from  objects 
before  using  the  acid,  but  experience  has  shown  that  this  is  not 
necessary,  as  by  the  use  of  heat  carbolic  acid  will  readily  absorb,  and 
eventually  replace  the  water  in  any  object  saturated  therewith. 

The  carbolic  acid  used  should  be  the  purest  that  can  be  obtained, 
and  it  will  be  as  well  to  keep  the  greater  portion  as  stock  in  a  dark- 
blue  glass-stoppered  bottle,  so  as  to  prevent  it  being  discoloured  by 
exposure  to  light.  From  this  can  be  transferred  as  required  a  small 
quantity  to  a  working  bottle  of  about  two  drachms  capacity.  If  the 
acid  is  so  pure  as  to  be  crystallized,  melt  what  is  in  the  smaller 
bottle  and  add  a  few  drops  of  spirits  of  wine,  which  will  easily  mix 
with  the  acid  if  held  for  a  few  minutes  over  the  spirit-lamp.  The 
acid  will  then  be  less  likely  to  crystallize  and  the  small  quantity  of 
spirit  used  will  not  affect  the  process.  Should  there  be  any  diffi- 
culty in  procuring  stock  of  perfectly  clear  acid,  the  ordinary  coloured 
acid  of  the  shops,  if  in  crystals,  may  be  used  without  fear.  As  will 
be  noticed  presently,  we  drive  off"  all  the  carbolic  acid  used,  replacing 
by  clear  balsam  or  dammar,  therefore  the  coloured  acid  can  do  no 
harm.  Perfectly  clear  acid  soon  becomes  discoloured  by  exposure  to 
light,  and  heat  lias  a  similar  effect;  when  we  boil  objects  in  acid 
and  allow  them  to  remain  for  a  few  days,  the  acid  will  then  have 
changed  to  a  rich  brown,  but  as  this  does  not  affect  the  object  steeped 
therein,  it  need  not  trouble  us  further. 

*  '  Jonra.  Micr.  Soc.  Vict.,'  i.  (1880)  p.  50. 


INVERTEBEATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  859 

The  advtantagos  claimed  for  this  process  are  that  objects  need 
never  be  allowed  to  dry  before  mounting  in  balsam  or  dammar ;  that 
the  operation  from  first  to  last  is  simple  and  cleanly  ;  while  compared 
with  the  old  turpentine  process,  this  is  wonderfully  rapid.  A  tiny 
insect  may  bo  caught  alive,  boiled,  cleared,  mounted  in  balsam,  the 
slide  finished  oft"  and  put  away  in  the  cabinet,  all  within  half  an  hour. 

Objects  saturated  with  water  should  be  drained  as  well  as  possible, 
without  allowing  all  the  water  to  run  off,  as  in  that  case  air  might  be 
admitted,  then  transferred  to  a  clean  test-tube,  covered  with  carbolic 
acid  from  the  working  bottle,  and  boiled  for  a  few  minutes  over  a 
spirit-lamp.  Corked  tightly,  a  test-tube  full  of  objects  in  acid  may 
be  put  asido  for  any  length  of  time  before  mounting.  When  we 
desire  to  mount  one  of  these  objects  we  transfer  it  to  a  clean  slide, 
put  on  a  thin  glass  cover,  and  with  the  aid  of  a  small  pipette  allow 
enough  clean  carbolic  acid  to  run  in  to  flood  the  object.  Having 
examined  under  the  Microscope,  and  arranged  it  to  our  liking,  we 
warm  the  slide  over  a  spirit-lamp,  and  place  sufficient  balsam  or 
dammar  on  the  slide  close  to  the  cover  ;  liquefied  by  the  heat  either 
medium  will  at  once  rim  in  and  drive  the  acid  out  at  the  other  side. 
This  will  be  greatly  facilitated  by  inclining  the  slide  and  holding  a 
small  piece  of  blotting  paper  under  the  thumb  close  to  the  lower  edge 
of  the  thin  cover.  When  all  the  acid  has  been  drawn  off,  the  slide  is 
then  placed  on  a  hot-plate  to  harden,  and  afterwards  finished  in  the 
usual  manner  by  scraping  off  the  superfluous  balsam,  wiping  the  slide 
carefully  with  a  clean  rag  moistened  with  spirits  of  wine,  and  finished 
on  the  turntable  by  sealing  the  cover  with  a  ring  of  Brunswick 
black  or  other  varnish. 

Another  aid  to  the  thorough  displacement  of  the  acid  is  to  use  the 
balsam  in  as  thick  and  pasty  a  condition  as  possible.  At  the  same 
time  this  is  not  essential  to  success,  as  thin  balsam  works  very  well. 
Benzine*  should  bo  used  in  preference  to  turpentine  to  liquefy 
balsam  that  has  become  too  stiff.  Newly  purchased  balsam  is  often 
very  thin.  In  this  case  it  is  advisable  to  bake  it  in  a  cool  oven  for 
some  days  until  it  is  hard  enough  to  resist  slight  pressure,  and  then 
add  about  one-fourth  part  of  benzine,  placing  the  bottle  in  a  hot- 
water  bath,  which  will  ensure  perfect  mixture.  Balsam  thus  prepared 
will  harden  quickly,  which  it  does  not  do  if  liquefied  by  turpentine. 
Turpentine  may  therefore  bo  excluded  from  the  Microscopist's 
laboratory. 

When  mounting,  it  is  well  to  bo  provided  with  several  pieces  of 
blotting  paper  about  an  inch  square.  These  should  bo  used  as  above 
described  to  aid  tlie  substitution  of  one  licpiid  for  another,  particularly 
when  displacing  watery  carbolic  acid  by  pure  acid. 

Vegetable  tissues  such  as  plant  leaves,  sections  of  wood,  &.C.,  after 
washing  in  water  may  be  drained  and  transferred  at  once  to  tlie  slide, 
covered  by  thin  glass,  flooded  in  carbolic  acid,  and  then  boiled  over 
the  spirit-lamp,  adding  fresli  acid  from  time  to  time  until  tlie  object 
is  perfectly  clear.     Air   bubbles    may  thus  bo  boiled  t)ut,  and  the 

*  Some  prcfur  chlornfonn,  wliicli  will  lic|Uefy  \hv  ))iilsam  willioiit  luat,  but  wo 
tliiuk  the  Ijcnzino  mucli  superior  in  aubaoquciit  opcrutious. 


8 (JO  RECORD    OF    CURRENT   RESEARCHES    RELATING    TO 

object  decolorized  and  rendered  beautifully  clear  by  the  process. 
When  cool  add  fresh  acid  and  follow  with  balsam  as  above. 

Insects  whole,  or  their  organs,  and  animal  tissues  generally  may 
be  treated  in  the  same  way,  which  seems  to  suit  such  organisms  better 
than  the  old  method.  The  action  of  the  acid  under  heat  is  rapid  *  and 
can  easily  be  stopped  when  required  by  simply  blowing  upon  the 
cover. 

In  preparing  Sertularians  and  Polyzoa,  where  the  empty  cells 
retain  the  air  so  pertinaciously,  this  annoyance  may  be  overcome  by 
boiling  in  water  and  allowing  to  cool,  replacing  the  water  by  carbolic 
acid,  when  alternate  boiling  and  cooling  at  intervals  more  or  less 
lengthened  will  effectually  dispose  of  air  in  the  cells.  Those  who 
have  opportunities  of  collecting  on  the  sea-shoro  will  find  that  just 
after  storms  many  species  will  have  been  washed  ujjon  the  beach, 
some  possibly  alive.  Objects  thus  obtained,  or  by  means  of  dredging, 
should  at  once  be  placed  in  small  phials  in  a  fluid  consisting  of  sj)irits 
of  wine  and  water  in  equal  parts — sea-water  will  do.  When  these 
are  taken  home,  they  should  be  washed  several  times  in  fresh  water 
to  get  rid  of  the  salt,  sorted,  and  transferred  to  a  mixture  of  spirits  of 
wine  and  fresh  v/ater  in  equal  jiarts.  They  can  thus  be  kept  in  good 
order  for  any  length  of  time,  or  they  may  be  mounted  at  once  by  the 
carbolic  process. 

Eadulas  or  palates  of  molluscs  should  be  boiled  in  strong  liquor 
potassfe  for  a  few  minutes,  well  washed  in  three  or  four  waters  to 
remove  all  traces  of  the  potash,  and  then,  treated  with  the  carbolic 
acid  as  above  described,  may  be  mounted  very  quickly. 

To  ensure  clear  mounts,  the  balsam  should  always  be  imme- 
diately preceded  by  perfectly  clean  acid,  displacing  with  the  aid  of 
blotting  paper  the  acid  previously  used.  If  this  be  neglected,  and 
the  acid  first  used  should  not  be  completely  removed,  a  little  cloudi- 
ness may  result  from  the  admixture  of  the  balsam  with  the  water  in 
the  acid.  In  this  case  the  slide  must  be  flooded  in  fresh  acid  to 
soften  the  balsam,  heated,  and  the  cloudy  balsam  drawn  off  by  blotting 
paper,  substituting  fresh  balsam." 

Wax  Cells. t — ^Mr.  F.  Barnard  gives  the  following  as  a  preferable 
process  for  making  these  cells  : — Take  a  small  piece  of  wax  according 
to  the  size  and  depth  of  the  cell  required,  place  it  in  the  middle  of 
the  glass  slip,  warm  it  thoroughly  over  a  spirit  lamp,  then  press  it 
upon  the  slide  perfectly  flat  and  even  with  a  smooth  surface.  This 
is  easily  done  by  means  of  what  he  calls  a  gauge  made  thus  :  on 
each  end  of  a  slip  of  glass,  cement  with  balsam  small  pieces  of  paper, 
card,  or  glass  of  the  thickness  of  the  required  cell,  moisten  the  under 
side  and  press  upon  the  warm  wax  till  down  as  far  as  the  end  pieces 
will  allow  ;  by  moving  this  gauge  about  a  little,  there  will  be  a 
tolerably  smooth  and  level  cake  of  wax  on  the  slide  the  thickness  of 
the  gauge. 

*  As  some  objects  are  injured  by  heat,  they  may  be  cleared  by  soaking  in  cold 
carbolic  acid  for  a  few  days,  or  until  cleared  sufficiently, 
t  '  Journ.  Micr.  Soc.  Vict.,'  i.  (1880)  p.  53. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPYj    ETC.  861 

The  centre  can  be  turned  out  with  a  penknife  or  other  convenient 
tool  on  a  turntable.  The  cell  can  be  cleaned  with  a  rag  moistened 
with  benzine,  or  to  avoid  the  difficulty  of  this  the  glass  slip  may  be 
covered  with  a  solution  of  gum  tragacanth,  to  which  a  small  quantity 
of  sugar  has  been  added,  allowing  it  to  dry  before  the  application  of 
the  wax,  when  the  marks  of  the  knife  left  in  turning  out  the  cell  can 
be  removed  by  washing  in  water  only.  These  cells  would  not,  how- 
ever, do  for  mounting  in  glycerine,  water,  &c.,  and  the  adhesion  of  the 
wax  to  the  slide  would  be  destroyed ;  but  if  the  pi-ocess  is  carried  a 
little  further  and  the  slide  with  the  cell  on  is  soaked  in  w^ater,  the 
cell  will  be  freed,  and  when  washed  and  dried  can  be  apjdied  to 
another  slide.  By  this  use  of  gum  any  number  of  cells  can  be  made 
and  kept  ready,  like  glass  and  vulcanite  cells. 

Dry  "Mounts"  for  the  Microscope— Wax  and  Gutta-percha 
Cells.* — The  following  is  by  Professor  Hamilton  L.  Smith  (in  the 
new  American  weekly  periodical  '  Science,'  w'hich  is  intended  to  be 
conducted  on  a  similar  plan  to  '  Nature  '). 

"  What  shall  we  use  to  preserve  dry  mounts  effectually  ?  Many 
may  think  that  nothing  is  easier  ;  a  cell  of  Brunswick  black ;  a  wax 
ring,  or  one  of  balsam  ;  but  the  question  is  not  thus  easily  to  be 
disposed  of.  The  writer  has,  within  the  last  five  years,  mounted,  or 
has  had  mounted  under  his  siqjervision,  some  15,000  slides  of  various 
microscopical  objects,  chiefly,  however,  foraminifera  and  diatoms  ; 
half  of  these  were  dry  mounts. 

Two  things  are  important — the  cell  should  be  quickly  and  easily 
made,  and  the  object  when  mounted  in  it  should  remain  unchanged. 
There  are  very  few  cells  as  now  made  which  will  fulfil  both  these 
conditions,  especially  the  latter.  The  deterioration  of  delicate  dry 
mounts,  and  especially  of  test  objects,  sometimes  within  a  few  months 
after  their  preparation,  but  more  or  less  certain  in  nearly  every  case, 
is  well  enough  known. 

All  of  the  dry  mounts  of  the  Euleustein  series  of  diatoms,  e.  g., 
which  I  have  seen,  are  spoiled ;  and  my  cabinet  is  full  of  such  prepa- 
rations. Even  Moller's  do  not  escape,  though  they  are,  u2)on  the 
whole,  the  most  durable.  I  have  abundance  of  amateur  works  that 
no  doubt  looked  very  beautiful  just  as  they  issued  from  the  hands  of 
the  enthusiastic  preparers,  which  are  now,  alas !  mere  wrecks ;  and, 
worse  than  this,  many  choice  and  rare  specimens,  which  I  cannot 
replace,  hopelessly  ruined. 

I  believe  that  I  was  the  first  one  to  suggest  the  use  of  sheet  wax 
for  the  bottoms  of  cells  for  foraminifera  and  other  opaque  objects, 
and  of  wax  rings  for  diatoms  and  other  transjiarent  objcjcts.  The 
number  of  spoiled  specimens,  especially  of  diatoms  and  delicate 
transparent  objects  which  I  can  now  show,  proves  that  this  method  of 
mounting  is  decidedly  bad.  I  have  lived  to  see  the  day  when  I  shall 
be  quite  glad  if  the  responsibility  of  suggesting  sucli  a  nuisance  as 
the  wax  ring  can  be  transferred  to  some  one  else.  For  large  opaque 
objects,  like  most  of  the  foraminifera,  seeds,  pollens,  &c.,  the  object 

♦  'Science,'  i.  (ISSO)  p.  'J(J. 


862  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

itself  is  not  so  mucli  injured,  but  the  covering  glass  will,  sooner  or 
later,  become  covered  (inside  tlie  cell)  on  the  under  surface,  with  a 
dew-like  deposit,  which,  when  illuminated,  will  glisten  almost  like  so 
many  minute  points  of  quicksilver,  and  though  out  of  focus  when  the 
object  is  viewed,  will  show  very  disagreeably,  like  a  thin  gauze 
between ;  and  with  transparent  objects  these  minute  globules  will  not 
only  dot  the  entire  field  as  so  many  dark  or  light  points,  but  the 
object  itself  will  appear  as  though  it  had  been  wetted. 

Not  long  ago  a  well-known  optician  showed  to  me  a  spoiled  slide 
oiPodura.  The  scales  were  very  good  and  large — in  fact,  it  was  a  slide 
which  I  had  given  to  him,  and  it  had  been  selected  by  myself  in 
Beck's  establishment  in  London  as  unexceptionably  fine.  This  slide 
began  slowly  to  show  symptoms  of  '  sweating.'  One  scale  after 
another  appeared,  as  though  moisture  had,  in  some  mysterious  way, 
penetrated  to  the  objects ;  it  was  not  water,  however,  for  when  the 
cover,  after  much  trouble,  had  been  removed,  and  warmed  sufficiently 
to  evaporate  anything  like  water,  the  scales  still  exhibited  the  same 
appearance,  and,  in  fact,  the  heat  required  to  get  rid  of  this  apparent 
moisture  was  so  great  that  the  scales  were  charred.  When  wax  rings 
are  used,  this  apparent  wetting  or  'sweating'  occurs  quickly,  and 
more  disagreeable  than  this,  innumerable  elongated  sj)ecks,  possibly 
crystalline,  appear  all  over  the  under  surface  of  the  cover-glass. 
The  same  trouble  occurs  when  any  of  the  ordinary  asphalt  prepara- 
tions are  used,  and  the  only  cement  which  I  have  thus  far  found  to 
be  tolerably  successful  is  shellac  thoroughly  incorporated  with  the 
finest  carbon  (diamond  black),  such  as  is  used  in  the  preparation  of 
the  best  printing  inks ;  the  solvent  being  alcohol,  these  rings  dry 
rapidly,  and  the  cover  is  attached  by  heating.  Even  these  rings 
cannot  be  trusted,  unless  thoroughly  dry,  and  siiontaneous  drying  is 
better  than  baking.  I  have  had  preparations  spoiled  after  mounting 
on  asphalt  rings,  which  had  been  made  for  over  a  year,  and  which 
had  been  subjected  for  several  hours  to  the  heat  of  a  steam-bath. 
With  large,  somewhat  coarse  objects,  the  defect  is  not  so  marked ; 
but  with  delicate  ones,  and  especially  test  objects,  it  is  simply  a 
nuisance.  With  care  I  think  the  shellac  rings  may  answer  pretty 
well.  I  have  not  tried  the  aniline  coloured  rings.  The  moisture 
(whatever  it  is),  and  the  crystalline  specks,  appear  to  be  derived  from 
the  vaporizable  parts  of  the  wax,  or  cement,  given  off  under  con- 
ditions where  one  would  suppose  such  a  thing  impossible ;  it  is,  how- 
ever, a  fact ;  I  have  the  proof  of  it,  and  I  dare  say  hundreds  of  others 
have,  too  plainly  evident. 

There  is  another  mode  of  making  cells  which  promises  well  for 
permanence.  My  attention  was  first  called  to  this  method  by  Dr.  Tulk, 
of  London,  who  suggested  for  this  purpose  the  thin  gutta-percha  tissue 
used  by  surgeons  in  the  place  of  oiled  silk.  I  have  had  special 
punches  made,  which  cut  neat  rings  from  this  tissue,  and  I  have  used 
these  rings  with  the  greatest  satisfaction.  I  have  no  preparation  of 
my  own  more  than  about  two  years  old  ;  these,  so  far,  show  no  signs 
of  change.  Dr.  Tulk  informs  me  that  he  has  them  ten  years  old,  and 
still  good  as  when  new.     I  have  noticed  that  in  some  recent  papers 


mVERTEBRATA,    CRTPTOGAMIA,    MICROSCOPY,    ETC.  863 

iu  the  microscopical  journals  the  writers,  wlio  with  little  experience 
have  so  lauded  wax  rings,  speak  of  '  thin  rubber '  for  rings  ;  evidently 
they  have  seen  somewhere  the  gutta-percha  mount,  and  supposed  it 
rubber — the  latter  will  not  answer,  melted  rubber  will  not  become 
hard.  One  beauty  of  the  gutta-percha  ring  is  the  very  moderate 
heat  required ;  it  is  thus  available  for  many  objects  which  might  be 
injured  by  the  greater  heat  necessary  for  the  asphalt  or  shellac  rings. 
As  tliese  rings,  in  the  arrangement  which  I  have  spoken  of,  can  be 
rapidly  made,  and  as  they  can  be  kept  for  any  length  of  time  (shut 
away  from  the  dust),  they  are  at  any  moment  ready  as  well  as  con- 
venient for  use.  The  preparation  is  first  arranged,  dried  or  burnt  on 
the  cover,  the  slide  cleaned,  a  ring  laid  on  the  centre,  and  on  this  the 
cover  is  placed ;  the  whole  is  now  held  together  by  the  forceps,  and 
sliijhtly  warmed,  just  sufficient  to  soften  the  gutta-percha ;  the  forceps 
may  now  be  laid  aside,  or  used  simply  to  press  the  cover  home, 
wanning  the  slide  gently,  also  the  cover ;  the  perfect  contact  of  the 
softened  '  tissue '  with  the  cover  and  slide  is  easily  recognized,  and 
with  a  little  care  this  can  be  effected  very  quickly,  and  nothing  further 
is  necessary.  A  finishing  ring  of  coloured  cement  makes  a  very  neat 
mount,  but  it  is  not  necessary." 

Mr.  F.  Kitton,  writing*  on  the  above  paper,  says  that  he  is  unable 
to  suggest  a  remedy. 

The  "  damping-off "  of  dry  mounts,  particularly  of  diatoms,  used 
to  be  (some  twenty-five  years  ago)  attributed  to  the  imperfect  washing 
of  the  diatoms :  either  the  acid  used  in  cleaning  was  not  eliminated,  or 
the  water  used  for  that  purpose  was  impure ;  but  preparations  which 
showed  no  acid  reaction,  and  which  had  been  carefully  washed  with 
the  purest  distilled  water  obtainable,  when  dry  mounted,  still  showed 
the  presence  of  moisture.  This  was  then  accounted  for  (?)  by  the 
suggestion  that  the  supposed  moisture  was  really  condensation  from 
the  asphalt  ring  supporting  the  cover ;  he  therefore  mounted  somo 
covers  perfectly  cleaned  (by  boiling  in  acid,  washing  in  distilled 
water,  and  afterwards  heating  them  over  a  Bunsen  burner)  on  somo 
hard  asphalt  rings;  the  slides  were  heated  sufficient  to  cause  the 
covers  to  adhere,  and  when  cold  the  latter  were  concave,  the  interior 
of  the  cell  being  nearly  exhausted  of  air.  These  mounts  (about  a 
dozen)  were  carefully  finished,  and  then  left  upon  the  table  for  several 
montlis  before  examination.  Some  of  them  showed  minute  globules 
on  the  inner  surface  of  the  cover-glass,  othei'S  minute  radiating  acicular 
crystals,  and  the  remainder  were  perfectly  clear. 

Tliis  experiment  being  far  from  satisfactory,  he  tried  "  shellac  " 
as  follows :  Perforating  a  hole  about  ,\  inch  in  diameter,  in  a  piece  of 
"  tliick  "  thin  glass,  he  covered  tlio  edges  with  the  lac,  and  cemented 
two  til  in  covers  to  it,  aiid  with  a  similar  result  to  the  previous  experi- 
ment. He  also  tried  paper  cells  saturated  with  "  shellac  "  dissolved 
ill  spirit,  or  soakeil  in  paraffin  wax,  but  in  no  case  were  they  invariably 
successful.  lie  has  therefore  come  to  the  conclusion  that  the  fault 
rests  with  the  cover  itself,  and  conGrniatory  to  this  opinion  is  the  fact 
that  the  covers  on  balsam  {hardened  before  attaching  the  cover)  sorac- 
♦  '  KukI.  M.rli..'  xxxi.  (1S80)  p.  ."iS'i. 


864  RECORD    OF    CURREMT    RE>,EARCHES    RELATING    TO 

times  sliow  like  deposits.  A  similar  "  sweating  "  almost  invariably 
occurs  on  our  oculars,  which  has  often  been  referred  to  an  exudation 
from  the  "  black  "  within  the  tube,  but  erroneously. 

Mr.  Kitton  has  in  his  i^ossession  a  small  box  of  thin  covers,  selected 
by  the  late  William  Smith,  author  of  the  '  Synopsis  of  British  Dia- 
tomacefc,'  of  which  at  least  30  per  cent,  exhibit  traces  of  oxidation  in 
the  form  of  minute  pits.  Query — Would  not  these  covers  have  shown 
the  so-called  "  damping-off  "  if  used  ? 

Covering  Fluid  Mounts.* — In  mounting  objects  in  fluid,  one  of 
the  principal  requirements  is  to  fasten  the  cover  of  the  cell  securely, 
so  as  neither  to  permit  leakage  nor  runuing-in  of  the  cement.  There 
are  two  methods  described  in  most  of  the  text-books,  both  of  which 
have,  according  to  Mr.  W.  M.  Bale,  disadvantages  that  impair  their 
utility  to  a  greater  or  less  extent. 

The  first,  which  is  recommended  by  Davies,  is  to  paint  the  cell  on 
its  upper  surface,  and  the  cover  on  its  under  surface  near  the  margin, 
with  thin  coats  of  gold  size  or  other  cement,  and  to  press  down  the 
cover,  forcing  out  the  superfluous  fluid  in  doing  so,  when  the  varnished 
surfaces  of  the  cover  and  cell,  not  being  affected  by  the  fluid,  will  adhere 
together.  It  is  a  serious  defect  in  this  process  that  it  will  not  permit 
of  sliding  the  cover  to  one  side  after  fixing  it,  if,  as  frequently 
happens,  it  should  be  necessary  to  readjust  the  position  of  an  object 
which  may  appear  on  examination  under  the  Microscope  to  require 
alteration.  Moreover,  thin  pellicles  of  fluid  frequently  remain  between 
the  cover  and  the  surface  of  the  cell,  preventing  the  perfect  adhesion 
of  the  cement,  and  allowing  the  ingress  of  air.  The  other  pro- 
cess, which  is  preferred  by  Dr.  Carpenter,  is  to  simply  apply  the 
cover  upon  a  cell  a  little  larger  than  itself,  and  when  the  outside  is 
dry  to  paint  it  round  the  margin  with  varnish,  giving  several  coats  as 
they  successively  dry.  This  has  the  disadvantage  of  not  holding  the 
cover  sufficiently  firmly  to  the  cell,  and  of  being  peculiarly  liable  to 
"  running  in." 

These  evils  are  to  a  great  extent  obviated  in  the  following  plan, 
which  is  especially  adapted  to  cells  of  any  thickness  not  greater  than 
that  of  ordinary  card  or  thin  glass.  An  essential  point  consists  in 
reversing  Carpenter's  rule,  and  using  a  cell  smaller  than  the  covering 
glass,  so  that  when  the  cover  is  in  position  it  projects  beyond  the  cell 
for  about  one-sixteenth  or  one-twelfth  of  an  inch  on  every  side.  The 
cells  may  be  made  of  any  suitable  material — thin  tissue  paper  will 
serve  for  minute  objects,  and  common  cardboard  for  those  of  con- 
siderable thickness.  The  cell  may  be  attached  to  the  slide,  or  simply 
placed  in  the  position  which  it  is  to  occupy,  without  being  cemented. 
The  objects  are  immersed  in  the  fluid  in  the  centre  of  the  cell  and  the 
cover  pressed  gently  down,  forcing  out  the  fluid  which  is  in  excess  of 
the  capacity  of  the  cell,  and  after  it  is  ascertained,  by  examination 
under  the  Microscope,  that  the  object  requires  no  readjustment,  the 
fluid  must  be  removed  from  the  space  between  the  cover  and  the  slide 
outside  the  cell-wall.     This  is  easily  accomplished  by  simply  allowing 

*  'Joiini.  Micr.  Soc.  Vict.,'  i.  (1880)  pp.  57-GO. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  865 

the  slide  to  stand  till  the  superfluous  fluid  has  evaporated,  or,  where 
the  cell  is  thick  enough,  blotting-paper  may  be  inserted  under  the 
margin  of  the  cover  to  absorb  it.  If  this  plan  be  adopted,  care  must 
be  taken,  after  the  fluid  is  removed,  to  allow  the  slide  to  stand  for  a 
minute  or  two  until  the  slide  and  the  under  surface  of  the  cover 
margin  are  quite  dry,  otherwise  the  cement  will  not  adhere.  Two  or 
three  drops  of  thin  balsam  or  gold  size  are  then  to  be  applied  at 
different  points  of  the  edge  of  the  cover,  when  it  will  run  in  by 
capillary  attraction  and  fill  the  space  outside  the  cell  and  beneath  the 
cover.  Directly  this  cavity  is  filled,  any  superfluous  cement  remaining 
on  the  slide  must  be  removed,  otherwise  the  running-in  process  will 
extend  too  far,  and  the  cement  will  enter  the  cell.  The  slide  may  then 
be  put  aside  to  harden.  It  will  often  be  found  after  a  day  or  two, 
especially  with  cells  of  considerable  thickness,  that  the  cement  will 
be  so  shrunk  fi'om  evaporation  as  no  longer  to  quite  fill  the  space 
destined  for  it,  when  a  little  more  may  be  applied  at  the  edges  till 
the  space  is  refilled,  care  of  course  being  taken  to  scrupulously  remove 
the  superfluous  cement  as  soon  as  the  requisite  amount  has  run  in. 
It  occasionally  happens  that  some  of  the  fluid  is  forced  out  of  the  cell 
in  process  of  drying,  and  occupies  part  of  the  space  which  should  be 
filled  only  by  the  cement.  This  "  running  out "  is  no  doubt  caused 
by  the  shrinkage  of  the  cement  drawing  the  cover  down  more  closely, 
and  if  the  fluid  extends  only  a  very  slight  distance  beyond  the  outer 
margin  of  the  cell  no  injury  is  done,  but  if  enough  is  expelled  to  make 
a  passage  nearly  or  quite  through  the  cement  wall,  there  will  be  a 
liability  of  leakage.  The  best  safeguard  against  this  mishap  is  to  be 
cautious  that  the  cement  is  not  run  in  till  the  whole  of  the  fluid  has 
evaporated  from  outside  the  cell,  or  even  till  the  thin  film  between 
the  covering  glass  and  the  upper  surface  of  the  cell  has  commenced  to 
dry.  When  this  occurs,  the  cover  will  generally  be  drawn  down  as 
closely  as  is  necessary,  and  the  cement  may  be  applied  with  reasonable 
security. 

The  result  of  this  operation  is  to  secure  a  double  cell,  the  inner 
part  consisting  of  the  paper  or  wliatcver  material  may  be  used,  and 
the  outer  of  a  solid  wall  of  cement  firmly  uniting  the  slide  and  cover, 
and  as  wide  as  may  be  required.  The  author  uses  a  cell  about  one- 
eighth  of  an  inch  less  in  diameter  than  the  cover,  giving  a  margin  of 
-jJ^  all  round.  Care  must  be  taken  in  finishing  slides  mounted  in  this 
manner,  as  ho  has  fomid  one  commence  to  run  in  on  the  application 
of  varnish,  after  being  mounted  some  months,  the  fresh  varnisli  having 
softened  the  original  cement.  This  difiiculty  would  probably  be 
obviated  by  using  a  rajjidly  drying  varnish,  and  only  applying  a  thin 
layer  at  once,  or  by  making  a  narrow  circle  of  gum  round  the  margin 
of  the  cover  and  aHowing  it  todrybefitre  using  the  finishing  material; 
or  by  using  jiaper  covers,  and  tlius  dis2)cnsing  with  varnish  entirely. 
Thei-o  can  bo  no  doubt  that  slides  mounted  in  this  way  will  have 
almost  tlio  permanency  of  balsam  mountings,  so  far  as  freedom  from 
external  influences  can  secure  it. 

A  modification  of  the  above  process  may  be  used  with  media  which 
will  not  evaporate  to  dryness,  such  as  glycerine  and  castor  oil.     In 

VOL.  III.  3    L 


866  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

this  case  it  will  be  advisable  to  place  the  object  iu  the  centre  of  the 
cell,  in  a  quantity  of  the  medium  so  small  that  on  j)ressing  down  the 
cover  the  drop  will  not  quite  fill  the  cell,  and  consequently  none  will 
be  forced  out.  The  cement  may  then  be  run  iu  under  the  margin,  as 
above  described.  If  the  medium  be  thin  and  likely  to  spread  over 
the  floor  of  the  cell  before  the  cover  can  be  applied,  it  will  be  better 
to  suspend  a  small  drop  from  the  centre  of  the  cover,  and  bring  it 
down  upon  the  object ;  and  in  any  case  the  cover  should  be  moistened 
with  the  medium  before  applying  it. 

The  author  adds  in  a  note  that  he  finds  Tuckett  advises  the  use 
of  a  cover  larger  than  the  cell,  in  order  to  i^revcnt  running  in ;  b\it 
as  he  does  not  withdraw  the  fluid  from  the  space  round  the  cell,  his 
method  gains  no  advantage  over  the  ordinary  plan  in  security  from 
leakage. 

Thickness  of  Cover-glasses.  —  Dr.  C.  Eeddots  points  out,*  in 
answer  to  a  complaint  that  cover-glasses  are  not  accurately  assorted 
as  to  thickness  by  the  dealers,  for  which  it  was  said  "  there  seems 
no  good  reason,"  that  the  good  reason  is  to  be  found  in  the  extra 
cost  that  would  be  entailed  by  measuring,  so  that  the  matter  is  better 
left  to  each  microscopist  to  do.  Moreover,  in  these  days  of  objectives 
with  large  working  distance — homogeneous-immersion  and  others — 
there  is  no  such  necessity  as  there  used  formerly  to  be  to  hunt  for 
very  thin  cover-glasses. 

Finishing  Slides. f — A  writer  in  the  '  American  Monthly  Micro- 
scopical Journal,'  having  used  dammar  dissolved  in  benzole  as  a 
mounting  medium  for  some  time  past,  finds  that,  when  thoroughly 
dry,  the  gum  becomes  brittle,  and  a  slight  jar  is  apt  to  start  the 
covering  glass,  and  rapid  destruction  of  the  slide  follows.  He  has 
found  it  necessary,  therefore,  to  run  a  ring  of  some  tough  material 
around  the  covering  glass  to  protect  it,  his  efforts  being  directed  to 
discovering  a  material  that  would  give  the  necessary  strength,  that 
can  be  easily  handled,  so  as  to  make  a  neat  finish.  The  best  results 
can  be  obtained  by  the  use  of  a  thick  copal  furniture-varnish — what 
is  known  as  rubbing-varnish — using  the  thickest,  finest  varnish  that 
can  be  procured,  and  putting  enough  dragon's  blood  in  the  bottle  to 
give  it  colour,  without  destroying  its  transparency.  It  should  be  so 
thick  that  a  small  drop  will  not  flow  from  the  camel's-hair  brush. 
The  older  it  is  the  better. 

The  slide,  having  been  cleaned  of  superfluous  gum  or  balsam,  should 
have  a  little  shellac  varnish  run  around  in  the  angle  formed  by  the 
covering  glass  and  the  slide  to  prevent  the  coloured  varnish  from 
running  under  the  cover  in  the  subsequent  operations.  When  this  is 
dry,  which  will  be  in  a  few  minutes,  the  slide  is  mounted  on  the  turn- 
table, and  a  sufficiency  of  the  varnish  put  round  the  edge  of  the 
co^j^ering  glass,  extending  over  the  slide.  The  turntable  is  then  put 
in  rapid  revolution,  and  with  the  point  of  a  knife  applied  to  the 
glass,  first  outside  on  the  slide  and  afterwards  inside  on  the  covering 

*  'Am.  Mrm.  MiVr.  Jmirn.,'  i.  (1S80)  p.  123.  f  I'-'^-,  PP-  122-3. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  867 

glass,  a  ring  is  spun,  whicli  may  be  made  as  narrow  as  is  desired, 
and  with  its  rounded  top  extending  above  the  covering  glass. 

The  slides  are  laid  aside  in  a  dry  place  for  at  least  a  week  to 
harden,  when  the  superfluous  varnish  can  be  cleaned  off  from  the 
glass  with  a  bit  of  soft  linen  rag  and  rottenstone  and  water,  rubbing 
the  whole  mount  gently  with  circular  strokes.  This  removes  the 
superfluous  varnish  from  the  glass  to  the  edge  of  the  ring,  leaving 
it  with  a  clean  circular  edge,  and  at  the  same  time  rubs  down  any 
inequalities  which  may  exist  in  the  ring  itself.  After  this,  wash  the 
slide  well  in  fresh  water  with  a  soft  brush  to  remove  all  traces  of  the 
rottenstone,  and  gently  dry  it  with  a  soft  cambric  handkerchief. 
When  it  is  dry,  a  few  circular  strokes  with  dry  cambric  on  the  end 
of  the  finger,  will  give  the  ring  a  semi-polish,  which  leaves  it  with  a 
very  neat  finish. 

The  whole  slide  is  usually  cleaned  with  the  rottenstone  and 
water,  so  that  when  it  is  dried  and  gently  wiped,  it  is  ready  to  receive 
the  label.  The  whole  process  is  quite  expeditious,  and  the  results 
are  so  satisfactory,  in  the  permanence  and  finish  of  the  slides,  that 
the  author  is  confident,  if  any  one  gives  it  a  fair  trial,  it  will  super- 
sede all  other  cements  for  a  like  purpose. 

Novel  Form  of  Lens.* — Dr.  Cusco,  ophthalmic  surgeon  in  one 
of  the  hospitals  of  Paris,  has  invented  a  lens  of  variable  focus,  in 
which  the  pressure  of  a  column  of  water  or  other  transparent  liquid 
is  made  to  alter  the  curvature  of  the  flat  faces  of  a  cylindrical  cell  of 
brass  closed  with  thin  glass  disks.  The  pressure  can  be  regulated 
by  a  manometer  gauge  to  any  required  degree  within  the  limits  of 
working.  It  is  said  that  the  lens  gives  a  sharp,  well-defined  focus. 
It  was  constructed  for  Dr.  Cusco  by  M.  Laurent. 

Swift's  Radial  Traversing  Substage  Illuminator.— Messrs.  Swift 
have  further  developed  the  idea  of  a  "  swinging  substage "  by  the 
apparatus  shown  in  Figs.  82  and  83.  The  essential  feature  is  the 
addition  of  a  second  sector  with  condenser  at  right  angles  to  the  first. 

The  following  is  their  description  of  the  apparatus  (slightly 
abridged). 

"  This  apparatus  has  been  constructed  for  the  purpose  of  increas- 
ing the  resolving  px-ojierty  of  high-power  objectives  by  causing  still 
more  oblique  pencils  to  impinge  on  the  object  than  can  be  obtained  by 
any  other  method.  The  arrangement  consists  firstly  of  an  arc-piece 
fixed  below  tlio  stage  radial  to  an  imaginary  line  drawn  through  tlic 
axis  of  the  objective,  and  in  tlie  same  plane  with  the  object.  On  this 
an  achromatic  condenser  of  special  construction  is  made  to  travel, 
thus  keeping  the  rays  of  light  on  the  object  during  its  entire  travers- 
ing, these  rays  converging  in  a  focus  through  the  front  lens  in  a  highly 
concentrated  form.  The  condenser  is  illuminated  by  a  rectangular 
prism. 

The  next  part  of  the  contrivance  consists  of  a  second  arc-picco 
placed  at  riglit  angles  to  the  former  one ;  this  also  cari'ies  a  similar 
achromatic  condenser  and  illuminating  prism,  and  moves  radial   to 

♦  'Nntnr.-.'  xxii.  (]»s())  p.  2S0. 

3  I.  2 


868  BEOORD    OF    CURRENT    RESEARCHES    RELATING    TO 

Fig.  82. 


the  same  centre.  Botli  these  arc-pieces  are  so  divided  that  each 
pencil  of  light  can  be  projected  at  a  similar  angle,  and  previous 
results  always  recorded  in  the  same  way.     Difficult  test  objects  are 


INVERTEBRATA,    CRYPTOGAMIA,   MICROSCOPY,    ETC. 


869 


readily  revealed,  especially  sucli  diatoms  as  have  rectangular   strisB 
or  markings 

With  diatoms  easily  resolvable,  and  only  requiring  one  pencil  of 
light  to  sliow  the  markings,  the  second  arc-piece  with  its  illuminating 
apparatus  can  be  turned  away  from  the  stage  as  shown  in  Fig.  83. 
The  figure  also  shows  how  ojiaquc  objects  may  be  illuminated,  viz. 
by  moving  the  condenser  of  the  first  arc-piece  above  the  stage  of  the 

Fig.  83. 


Microscope,  when  a  pencil  of  light  can  bo  projected  on  to  the  object 
more  perpendicularly  than  with  the  buH's-cyc  condenser,  thus  pre- 
venting shadows  in  coarse  or  deep  objects  which  often  produce  dis- 
tortion and  false  appearances.  When  the  apparatus  is  used  for  opaque 
objects  with  a  lower  power  than  the  1-inch  objective,  the  achromatic 
combination  can  bo  removed  and  the  light  directed  from  the  prism, 
which  can  be  made  to  give  convergent  rays  sufficient  for  use  with  a 
4-inch  objective. 

A  great  advantage  is  presented  in  this  arrangement,  viz.  that  a 
more  obli({uo  angle  of  light  can  bo  obtained  with  it  tlian  by  other 
swinging  stages,  in  consequence  of  the  optical  combination  (with  all  its 
fittings  included)  being  less  than  ,V  the  diameter  of  the  establislied 
size  of  substage  used  with  the  Zcntmaycr,  for  instance,  thus  enabling 
the  apparatus  to  bo  moved  further  up  to  the  under  stirfuce  of  tho 
stage  than  if  its  mountings  were  larger.  A  still  further  improvement 
claimed  for  it  is  that  tlie  whcde  of  the  apparatus  and  its  belongings 
can  be  easily  detached  from  tho  Microscope,  and  an  ordinary  substago 
slid  into  tlie  same  fitting  for  tlio  purpose  of  receiving  pcdarizing 
apparatus,  paraboloid,  spot  lens,  &c.  As  its  iitting  is  not  adapted  to 
or  coimected  with  tho  stage,  tho  firmness  and  stability  of  this  very 
important  portion  of  tho  instrument  are  not  thereby  imi)airod." 


870 


RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 


Fig.  84. 


Holmes's  "Isophotal"  Binocular  Microscope. — The  description 
of  this  Microscope  should  be  added  to  the  "  Curiosities  of  Literature." 
The  paper  was  recently  presented  to  this  Society,  but  withdrawn  on  our 
objection  to  print  it  au  serieux  and  without  alteration,  having  appa- 
rently met  with  a  similar  objection  at  the  hands  of  the  British  Asso- 
ciation authorities  last  year.  Deviation  is  described  as  being  "  half 
as  great  when  an  isosceles  prism  is  used,"  it  being  apparently  supposed 
that  an  "  isosceles "  prism  has  an  invariable  angle  instead  of  an 
infinite  variety  of  angles.  A  prism  is  commended  as  giving  "  flatness 
of  field."  Reflecting  prisms  are  described  as  causing  more  loss  of 
light  and  more  error  than  refracting  ones,  and  notwithstanding  a 
5  per  cent,  loss  of  light  by  transmission,  a  net  gain  of  5  per  cent,  is 
vouched  for  as  the  result  of  the  interposition  between  the  objective 
and  the  eye-piece  of  the  refracting  "Isophotal"  prism  (!).  The 
"  distance  of  the  prism  from  the  objective  in  relation  to  the  eye-piece  " 
is  held  to  have  an  efiect  on  the  angles  of  incidence  and  emergence. 
Wenham's  prism  is  denounced  as  causing 
the  "  left-eye  view  to  be  darkened,  definition 
impaired,  field  cylindrically  distorted,"  and 
Stephenson's  as  having  prisms  with  "  twelve 
surfaces"  (instead  of  six  or  eight),  and  as 
"practically  useless  from  the  line  of  sight 
being  at  right  angles  to  the  objective,  and 
from  torsion  of  the  image."  An  achromatic 
prism  is  italicized  as  having  only  "three  sur- 
faces "  (instead  of  four),  and  finally  a  right- 
angled  prism  is  apparently  in  future  to  be 
known  as  a  "  Holmes  prism." 

The   Isophotal   prism   as  drawn  by  the 
inventor  is  shown  in  Fig.  84  (fac-simile). 

The  following  is  the  inventor's  descrip- 
tion verbatim:* — 

"  In  the  course  of  experiments  to  produce 
a  Microscope  that  might  be  used  with  both 
eyes,  I   have  originated  three  constructions. 
The  first  of  these  acted  by  total  reflection,  the  second  by  free  trans- 
mission through  divided  glasses,  and  the  third  by  an  achromatized 
jprism." 

[The  first  f  and  second  J  plans  are  then  described.] 
"  With  regard  to  my  third  and  last  plan  of  binocular  Microscope, 
by  means  of  an  achromatic  prism.  The  advantages  I  claim  for  it  are 
(1)  that  it  can  be  used  as  a  monocular  or  as  a  binocular  without 
change  of  body-tube ;  (2)  that  it  gives  two  equally  lighted  fields  in 
two  equally  inclined  body-tubes ;  (3)  that  it  gives  stereoscopic  effect 
with  less  loss  of  light  or  definition  than  any  other  construction  with 
undivided  glasses;  and  (4)  from  its  evident  adaptability  to  higher 
powers." 

*  'Engl.  Mech.,'  xxxi.  (1880)  p.  464. 

+  '  Journ.  Quek.  Micr.  Club,'  i.  (1869)  p.  175. 

J  '  Mon.  Micr.  Jouru.,'  iii.  (1870)  p.  273. 


mVERTEBRATA,    OEYPTOGAMIA,    MICROSCOPYj    ETC.  871 

[Here  follows  a  description  with  diagrams  of  various  binocular 
Microscopes,  viz. : — Eiddell's  (1851),  Nachet's  (1852),  Wenham's  first 
(1853),  Holmes's  first  (1858),  Wenham's  second  (1860),  Holmes's 
second  (1869),  Stephenson's  (1870).] 

"  Here,  then,  we  have  six  different  systems  employing  prisms 
having  from  four  to  twelve  surfaces  to  absorb  light  and  impair  defini- 
tion. Division  and  angulation  of  the  objective  [Holmes's  second 
plan  J  disposes  of  all  these  sources  of  error,  and  gives  directness  and 
value  to  an  observation ;  but  when  that  plan  is  considered  inadmis- 
sible, the  solution  of  the  problem  must  rather  be  sought  in  the  direc- 
tion of  a  refracting  arrangoaent  of  few  surfaces,  as  less  light  is  lost 
and  less  error  introduced  thus  than  by  any  number  of  reflecting 
prisms. 

These  considerations  led  to  my  third  binocular.  Fig.  84,  wherein 
one  achromatic  prism  of  three  surfaces*  of  the  form  and  in  the  position 
shown,  divides  the  light  from  the  objective  and  bends  it  into  itself, 
until  both  its  halves  cross  each  other  and  diverge  from  opi)osite  sides 
into  two  eye-pieces.  I  call  this  the  Isopliotal  prism,  and  it  gives  the 
most  correct  stereoscopic  effects  to  all  objects  viewed,  without  im- 
pairing illumination  or  definition. 

The  light  lost  by  transmission  is  about  5  per  cent.,  and  the  gain 
by  observing  with  two  eyes  is  about  10  per  cent. ;  therefore,  a  more 
brilliant  view  is  obtained  in  this  manner  than  by  a  monocular,  using 
the  same  glass  and  illuminator. 

The  two  equally  inclined  bodies  of  the  Microscope  swing  on  a 
pivot,  at  their  junction,  to  such  extent  as  to  bring  one  of  them  vertical, 
when  the  instrument  becomes  a  monocular  by  merely  withdrawing 
the  prism.     This  motion  was  ^irs/  devised  by  me  for  this  Microscojie. 

In  applying  any  refracting  prism  to  a  beam  of  light  carrying  an 
image,  it  is  necessary  to  place  the  prism  in  such  a  position  that  it 
shall  refract  in  its  least  degree — that  is,  cause  the  minimum  deviation 
of  the  beam  acted  on ;  in  all  other  positions  the  image  of  a  circular 
spot  of  light  will  be  elongated  to  an  elliptical  form. 

In  adapting  a  pair  of  prisms  to  bend  the  image  pencils  from  the 
halves  of  an  objective  across  each  other  into  opposite  eyes  (Fig.  81), 
the  violence  is  greater  than  if  they  were  to  be  bent  only  into  adjacent 
eyes.  It  therefore  becomes  important  to  construct  the  prisms  of  such 
a  form  as  to  give  the  least  refraction  possible  for  a  given  angle  of 
glass ;  otherwise,  the  resulting  images  being  elongated  in  one  direc- 
tion, a  distorted  view  woiild  be  produced. 

This  error  is  entirely  eliminated  by  attention  to  two  consider- 
ations. Firstly,  the  prism  must  receive  its  beam  at  an  aiignhir  and  not 
at  a  perpendicular  incidence  ;  secondly,  the  distance  of  the  prism  from 
the  objective  in  relation  to  the  cyc-piecc  must  bo  such  as  to  make  the 
angles  of  incidence  and  emergence  equal  to  each  other — no  other 
form  or  position  being  admissible  without  distortion.  I  claim  to  bo 
the  first  to  have  recorded  this  action  in  connection  with  this  subject, 
and  to  have  based  the  construction  of  an  instrument  on  the  deduction. 

*  This  ahoiild  of  course  bo  /"»;•  surfaces,  which  is  equivalent  to  cijlit  iu  all, 
the  same  us  th«  ytcpheiiaou  binocular  when  the  rellccting  plute  is  used. 


872 


RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 


Fig.  8G. 


The  achromatized  prism  for  stereoscopic  effects  can  take  but 
three  forms.  For  simj^licity's  sake,  I  will  ouly  deal  with  one  half  of 
the  prism,  the  other  half  beius;  symmetrical. 

If  a  right-angled  prism  (Fig.  85)  receive  the  rays  at  a  perpen- 
dicular incidence,  the  whole  of  the  refraction  takes  place  at  the 
inclined  second  surface,  and  the  distortion  is  the  greatest  possible. 

If  an  isosceles  prism  (Fig.  86)  be  used,  the  deviation  is  half  as 
great,  but  still  so  considerable  as  to  preclude  its  use. 

But  if  my  form  of  prism  (Figs.  84  and  87)  receive  the  incident 
Fig.  85.  beam  on  its  inclined  surface,  the  angles  are  more 

nearly  equal  than  in  any  other  form  in  any  other 
position,  and  perfect  equality  may  be  obtained  by 
modifying  the  relative  distances  between  objec- 
tive, prism,  and  eye-piece. 

These  conditions  at  once  indicate  the  dimen- 
sions of  the  prism.  When  in  position  it  must  be 
large  enough  to  admit  all  the  rays  from  the 
objective  at  the  distance  seen  to  give  no  distor- 
tion of  a  known  object ;  and  here  we  have  dis- 
tinctness and  flatness  of  field  also. 

Such  is  the  Isoj)hotal  prism,  giving  its  name 
to  the  Microscope.     In  the  course  of  experiments, 
I   have   made    the    prisms   of   the    lightest   and 
densest   glass,  of  the   longest   and    shortest  di- 
verging power,  as  large  as  a  shilling,  and  again 
so  small  as  to  slide  into  a  j-inch  objective ;  and 
have  arrived  at   what  I  believe  to  be  the  best 
form  for  practical  use." 
It  need  hardly  be  said  that  the  quality  of  "  Isophotal "  is  not  (as 
the  inventor  would  seem  to  imply  by  the  title  of  the  paper)  by  any 
means  peculiar  to  this  instrument,  those  of  Riddell,  Nachet,  Stephen- 
son, and  Ahrens,  being  equally  "  isophotal." 

We  are  fortunate  in  having  been  for  some  years  the  possessor  of 
one  of  these  instruments,  which  we  preserved,  not  so  much  on  account 
of  the  "  Isophotal  "  prism,  as  for  the  mechanical  curiosity  of  the 
arrangement  by  which  "  the  two  equally  inclined  bodies  of  the  Micro- 
scope swing  on  a  pivot  at  their  junction  to  such  an  extent  as  to  bring 
one  of  them  vertical,  when  the  instrument  becomes  a  monocular  by 
merely  withdrawing  the  prism."  This  motion,  Mr.  Holmes  says, 
"  WB-s  first  devised  by  me  for  this  Microscope." 

Mr.  Wenham  subsequently  pointed  out*  the  incompleteness  of 
the  article  in  regard  to  the  binocular  Microscopes  previously  made 
(Nachet's  existing  form  and  others  being  omitted),  and  also  that  the 
"  Isophotal  prism "  is  the  same  as  that  devised  by  himself  in 
1860.t 

Mr.  Holmes,  in  reply  to  Mr.  Wenham's  first  note,  wrote :  J — 

"  Matters  of  date  have  nothing  to  do  with  the  subject,  there  being 

*  '  Engl.  Mech.,'  xxxi.  (1880)  pp.  500  ami  5G9. 
t  Sec  '  Moil.  Mi.T.  Jouni.,'  1874,  p.  129. 
t  *  Engl.  Mcch.,'  xxxi.  (1880)  p.  516. 


Fig.  87. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  873 

no  question  of  priority  in  dissimilar  inventions.  My  prism  does  not 
claim  to  be  either  a  copy  of,  or  au  improvement  on,  Mr.  Wenliam's 
prism  of  1860,  as  he  appears  to  suppose,  but  is  substantially  an  inde- 
pendent invention,  made  ten  years  later  (1870)  in  total  ignorance  of 
Mr.  Wenbam's  prism.  .  .  .  And  I  have  only  to  say,  in  conclusion,  that 
my  prism  is  as  different  from  Mr.  Wenbam's  prism  as  a  Huygbenian 
eye-piece  is  different  from  a  Ramsden  eyo-picce." 

Nachet's  Microscope  with  Rotating  Foot. — A  Microscope  was 
devised  some  time  ago  by  M.  Nachet  to  embody  a  rotatory  motion  in 
azimuth  around  the  mirror.     This  was  effected  as  follows  : — 

The  base  of  the  stand  was  a  solid  disk  of  metal,  in  the  centre  of 
the  face  of  which  the  mirror  was  attached  with  Nachet's  usual  articu- 
lations, permitting  free  motion  in  all  directions.  Near  the  edge  of  the 
base  a  circular  groove  was  made,  into  which  the  foot  of  the  Micro- 
scope proper — a  ring  of  metal  carrying  the  pillar  support,  as  in  the 
Beckett  lamp — was  fitted,  and  made  to  rotate  easily.  The  centre  of 
this  circular  foot  was  made  coincident  with  the  optic  axis  of  the 
Microscope.  It  is  obvious  that  so  long  as  the  object  remained  in  the 
axis  of  rotation  (which  was  secured  by  the  Microscope  being  used  in  a 
vertical  position),  the  azimuthal  rotation  around  the  mirror  was 
practically  perfect,  except  just  where  the  pillar  of  the  stand  intercepted 
the  light  on  the  mirror ;  and  the  varying  effects  of  light  due  to  this 
motion,  when  the  mirror  was  placed  excentrically,  could  be  observed 
with  facility. 

The  stand  was  intended  to  provide  in  the  simplest  form  the  equi- 
valent of  a  perfectly  concentric  rotating  stage,  such  as  is  adapted  to 
M.  Nachet's  more  elaborate  stands.  We  have  never  understood  why 
this  inexpensive  form  of  Student's  stand  has  been  withheld  from 
popular  appreciation. 

Edmunds's  Parabolized  Gas  Slide  and  Nachet's  Gas  Chamber.— 
Dr.  Edmunds  claims  that  everything  which  can  be  accomplished  by 
means  of  the  latter  apparatus  *  may  also  be  accomplished  by  the 
parabolized  gas  slide.f 

For  the  study  of  such  coarser  microscopical  objects  as  do  not  need 
the  black-ground  effects  of  the  immersion  paraboloid,  it  is  necessary 
only  that  a  ring  of  tin-foil,  wax,  or  shellac  bo  interposed  between  the 
margin  of  the  thin  cover  and  the  toj)  of  the  slide,  oil  or  grease  being 
still  used  to  seal  up  the  interspace.  Thus  tlie  thin  cover  and  the  film 
of  material  under  observation  is  lifted  away  from  immersion  contact 
with  the  top  of  the  central  paraboloid,  and  gaseous  reagents  act  in- 
stantaneously upon  the  object.  If  also  a  slender  ring  of  cotton  or  silk 
bo  packed  into  the  bottom  of  the  annular  channel,  it  serves  to  hold 
water  and  keep  up  the  humidity  of  the  object  when,  from  any  cause, 
it  is  less  convenient  to  pass  gaseous  reagents  over  a  piece  of  wet  cotton- 
wool before  entering  the  annulus  of  the  slide. 

Dr.  Edmunds  also  considers  that  the  gas  chamber  introduces  a 
practical  ditliculty,  inasmuch  as  on  changing  the  reagent  it  takes  a 
long  time  to  sweep  the  chamber  clear  of  its  previous  contents,  and 

♦  See  this  Jouruul,  ante,  i>.  707.  t  I'^iil-.  1'   583. 


874  KECORD   OF    CURRENT    RESEARCHES   RELATING   TO 

therefore  it  becomes  difficult  to  determine  the  point  at  whicli  tlic 
effects  of  the  various  reagents  begin  and  end.  On  the  other  hand,  in 
the  gas  slide  the  annular  channel  is  a  mere  continuation  of  the  tube, 
and  is  instantly  swept  clear,  so  that  the  effects  of  various  reagents 
mark  themselves  off  sharply. 

Advantages  of  the  Binocular  Microscope. — Very  varied  opinions 
exist  as  to  whether  the  binocular  Microscope  is  or  is  not  of  practical 
value  in  histological  investigations.  Such  authorities  as  Professors 
Huxley  *  and  Lankester  in  England,  Professor  Eanvier  in  France,  f 
and  the  German  biologists  almost  without  exception  have  pronounced 
against  it.  Nevertheless  there  is  undoubtedly  a  large  class  of  cases 
in  which  the  binocular  Microscope  is  of  the  greatest  use  in  the  ready 
recognition  of  the  true  structure  of  an  object,  and  this  is  especially  so 
in  transparent  objects  in  which  the  precise  position  of  one  part  above 
or  below  another  can  be  recognized  by  means  of  a  binocular  with 
exceptional  facility,  and  as  is  said  by  the  writer  of  the  paper  next 
referred  to,  "  there  is  no  difficulty  in  deciding  whether  a  fine  nerve- 
termination  passes  over  or  under  or  into  a  connective-tissue  corpuscle." 
Several  cases  occurred  during  the  last  scientific  session  in  which  it 
was  clear  that  the  observers  had  failed  to  appreciate  the  true  relation 
of  the  parts  of  the  object  in  consequence  of  the  use  of  a  monocular 
instrument. 

Whilst,  however,  we  object  to  the  view  that  the  binocular  is  not 
of  value  in  biological  investigations,  we  have  to  call  attention  to  the 
necessity  of  avoiding  an  error  of  an  opposite  kind,  viz.  of  laying  too 
much  stress  on  the  perfection  of  the  stereoscopic  effect  when  objec- 
tives of  high  angle  are  used.  An  instance  of  this  is  to  be  found  in  a 
recently  published  paper,|  the  writer  of  which  refers  to  the  "  bold 
relief"  obtained  with  a  Wenham  prism  used  with  an  objective  of  high 
angle.  Cells  are  described  as  being  seen,  "not  as  flat  plates,  but 
as  spheroidal  bodies."  Now  Dr.  Carpenter  long  ago  pointed  out  § 
that  with  large  angles  the  effect  of  projection  is  so  greatly  exaggerated, 
that  in  the  case  of  perfectly  spherical  objects  the  side  next  the  eye 
instead  of  resembling  a  hemisphere  looks  like  the  small  end  of  an 
egg.  "  Hence,"  he  says,  "  it  may  be  confidently  affirmed — alike  on 
theoretical  and  on  practical  grounds — that  when  an  objective  of  wider 
angle  than  40°  is  used  with  the  stereoscopic  binocular  the  object 
viewed  by  it  is  represented  in  exaggerated  relief,  so  that  its  apparent 
form  must  be  more  or  less  distorted." 

In  addition,  it  may  be  noted  that  high-angled  objectives  having 
little  "  penetration "  produce  a  false  sense  of  stereoscopic  effect  by 
reason  of  the  parts  of  the  object  which  are  within  and  without  the 
focus  being  larger  than  those  which  are  in  focus. 

Reduction  of  Angle  of  Aperture  with  the  Binocular. — Micro- 
scopists  should  bear  in  mind  that  it  is  only  in  one  direction  that  the 
binocular  reduces  the  angle  of  aj)erture  of  objectives.     If  for  instance 

*  '  Journ.  Quek.  Micr.  Club,'  v.  (1879)  p.  146. 

t  See  tliis  Journal,  i.  (1878)  p.  149. 

t  '  Quar.  Journ.  Micr.  Sci.,'  xx.  (1880)  p.  318. 

§  '  The  Microscope  and  its  Revelations,'  5th  ed.  (1875)  p.  C9. 


INVERTEBEATA,    CIIYPTOGAMIA,    MICKOSCOPY,    ETC. 


875 


an  object  have  parallel  lines  upon  it,  and  these  lie  in  a  direction  from 
the  back  to  the  front  of  the  stage,  the  diffraction  spectra  will  bo 
arranged  in  a  row  at  right  angles  to  the  lines,  and  half  of  the  spectra 
which  would  otherwise  have  been  admitted  will  be  cut  off  by  the 


Fig.  88. 


Fig.  89. 


z 

o 


2 

o 


Object. 


Spectra. 


prism  (Figs.  88  and  89).  If,  however,  the  object  is  turned  round  so 
that  the  lines  run  from  left  to  right,  the  row  of  spectra  will  bo 
admitted  (Figs.  90  and  91),  and  there  will  consequently  bo  no 
diminution  of  aperture. 


Fig.  90. 


Fig.  91. 


Object. 


Spectra. 


If  the  number  of  lines  in  the  object  were  doubled,  the  distance 
between  the  spectra  would  also  be  doubled,  and  the  spectrum  No.  1 
in  Fig.  89  would  occupy  the  place  of  No.  2,  and  would  thus  fall 
outside  the  field,  and  there  would  bo  no  resolution.  On  turning  tho 
object  round,  however  (see  Figs.  90  and  91),  the  spectrum  No.  1, 
though  more  widely  separated  from  the  central  illuminating  beam 
by  reason  of  the  greater  fineness  of  the  lines  would  still  fall  within  tho 
field  (occupying  the  jdace  of  No.  2)  and  tho  object  would  be  resolved. 

It  is  therefore  of  practical  importance  to  see  that  the  object  is 
properly  placed  when  a  binocular  is  used. 

Apertures  exceeding  ISC  in  Air.  —  Many  microscopists  still 
experience  a  difficulty  in  gras])ing  tho  idea  of  an  object-glass  having 
an  upcrture  "  exceeding  180'  in  air,"  but  a  little  consideration  should 
di8j)cl  any  difficulty. 

Fig.  92  represents  the  theoretical  maximum  of  180"  in  oil  or  other 
homogeneous  fluid.  It  is  a  semicircle,  enclosing  30  spaces,  radiant 
from  the  point  A  (of  6°  each),  S])read  out  as  a  fan,  through  which  the 
diffraction  spectra  emanating  from  A  may  bo  su])posed  to  pass. 

If  wo  now  substitute  for  tho  oil  a  fluid,  such  as  icater,  having  a 


876 


RECOKD   OF    CUKRENT    RESEARCHES   RELATING    TO 


lower  refractive  index,  the  radiant  spaces  will  become  wider,  and  can 
therefore  no  longer  be  contained  in  the  semicircle,  as  is  shown  in 
Fig.  93.  The  fan  will  have  opened  out,  and  instead  of  the  original 
30  spaces  there  will  be  only  26f ,  the  other  3^,  outside  the  semicircle, 
being  excluded. 

If  we  now  substitute  air,  we  shall  have  a  further  widening  of  the 
radiant  spaces;  the  fan  will   have  been  yet  further   expanded  (as 


Fig.  93. 


Fig.  92 


Water. 


Fig.  94, 


Air. 


shown  in  Fig.  94),  arising  from  the  still  lower  refractive  index  of  air, 
and  the  semicircle  will  contain  no  more  than  20  spaces,  10  of  them 
being  now  beyond  the  180°, 

It  will  therefore  be  seen  that  while  an  aperture  of  180°  in  aii- 
includes  (in  the  illustration  given)  only  20  radiant  s])aces,  180°  in 
water  and  oil  include  respectively  26f  and  30,  these  numbers  repre- 
senting the  respective  apertures  in  air,  water,  and  oil,  the  smallest 
number  (20)  rejiresenting,  as  before  stated,  180°  in  air. 

The  whole  confusion  has  arisen  from  not  getting  beyond  the 
simple  and  obvious  fact,  about  which  there  can  be  no  dispute,  that  a 
dry  lens  cannot  have  an  aperture  of  more  than  180°.  That  which  is  not 
appreciated  is  the  fact  that  by  substituting  for  the  air  of  the  dry  lens 
either  water  or  some  other  more  refractive  medium  than  aii\  the  condi- 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  877 

tions  are  entirely  changed,  and  tliat  "  aperture  "  is  not  a  question  of 
"  angles"  simply  as  angles,  at  all. 

Diameter  of  Microscope-tubes.^ — In  a  paper  read  two  or  three 
years  ago  to  the  Sau  Francisco  Microscopical  Society  (now  first  pub- 
lished *),  Dr.  J.  H.  Wythe  says  that  the  diameter  of  the  Microscope- 
tube  has  an  important  relation  to  the  distinctness  and  luminosity  of 
the  image.  Few  tubes  are  wide  enough  to  utilize  more  than  a  small 
proportion  of  the  rays  proceeding  from  an  objective.  The  field-glass 
of  the  eye-piece  should  be  of  the  greatest  diameter  possible  for  its 
focal  length,  and  the  tube  wide  enough  to  receive  it,  in  order  to 
concentrate  the  greatest  number  of  rays  from  the  objective.  The 
short  tubes  of  French  and  German  Microscopes  are  supplied  with 
narrow  eye-pieces,  which  cut  the  cone  of  rays  nearer  the  objective, 
and  give  a  more  brilliant  image  than  would  be  possible  in  a  longer 
tube.  If  the  tube  be  longer,  it  must  also  be  wider,  and  the  eye-piece 
of  corresponding  diameter. 

Wythe's  Amplifiers. — Dr.  Wythe  in  the  same  paper  proceeds  to 
explain  his  views  as  to  the  construction  of  amplifiers,  some  of  which 
he  exhibited  to  the  Society,  which  were  considered  to  be  a  great 
improvement  upon  any  previously  seen. 

"  In  considering  the  construction  of  the  Microscope  with  a  view  to 
greater  amplification  by  the  eye-piece,  it  occurred  to  me  that  the 
concave  lens  or  meniscus  used  to  diverge  the  rays  of  the  objective 
should  form  a  part  of  the  eye-piece,  and  be  of  as  large  diameter  as  the 
tube  will  allow.  If  it  be  of  small  diameter,  it  must  be  placed  nearer 
the  objective.  This  is  the  form  and  position  of  the  amplifiers  of 
Tolles,  Zentmayer,  and  others. 

One  of  the  amplifiers,  exhibited  by  me  to  the  Society  on  a 
previous  occasion,  consists  of  a  conical  meniscus,  whose  position  in 
the  tube  and  eficcts  correspond  with  the  amplifiers  above  named.  With 
this  simple  addition  placed  in  the  lower  end  of  the  draw-tube  the 
magnifying  power  of  an  objective  can  be  nearly  doubled  with  little 
loss  of  light  or  of  definition. 

The  other  form  of  amplifier  now  exhibited  is  still  better.  A 
double  concave  lens,  or  meniscus,  of  as  great  diameter  as  the  tube 
will  allow  and  of  considerable  diverging  power,  is  placed  at  a  distance 
of  from  2  to  4  inches  in  front  of  the  eye-piece.  In  the  improved 
form  in  wliich  I  now  present  it,  a  concave  meniscus  of  6  inches 
equivalent  focus  and  1;\-  inch  diameter  (which  formerly  served  as 
part  of  the  object-glass  of  a  small  telescope),  is  placed  in  a  draw- 
tube  at  the  end  next  the  eyc-pieco  and  about  3  inches  from  the 
latter.  To  counteract  the  aberration  of  the  amplifier,  I  have  some- 
times substituted  foi'  the  plano-convex  field-glass  of  the  Huyghenian 
eye-piece  a  convex  meniscus  of  short  focus,  which  gives  also  a  very 
wide  and  flat  field  of  view.  Ordinary  eye-pieces  and  the  pcrisco])iC 
eye-pieces  of  Gundlach  may  also  bo  used  with  the  amplifier.  Tlie 
amplifying  eyc-pieco,  thus  constructed,  1ms  given  me  great  satisfaction. 
If  the  concave  meniscus  were  made  achromatic,  it  would  doubtless  be 

*  '  Am.  Joiini.  Mior.,'  v.  (1880)  p.  81. 


878  EECORD    OF   CURRENT   RESEARCHES   RELATING   TO 

a  still  further  improvement,  yet  the  performance  of  the  eye-piece 
leaves  little  to  be  desired.  The  wavy,  basket-like,  longitudinal  strise 
on  Surirella  gemma  and  the  hexagons  on  P.  angulatum  are  well  seen 
with  a  \  objective,  and  the  Frustulia  Saxonica  and  A.  pellucida  (dry) 
have  been  resolved  by  it  with  a  non-adjusting  ^  of  Gundlach's. 

In  place  of  the  concave  meniscus  referred  to,  I  have  also  used, 
with  nearly  as  good  effects,  a  double  concave  lens  of  2  or  3  inches 
equivalent  focus,  such  as  can  be  obtained  at  an  optician's  for  about 
50  cents.  So  that  by  a  very  small  cost  of  time  and  money,  the  pos- 
sessor of  an  ordinary  objective  may  increase  the  power  of  his  instru- 
ment to  a  very  great  degree. 

I  reiterate  the  conviction  before  expressed,  that  further  improve- 
ment of  the  Microscope  may  be  looked  for  in  the  construction  of  eye- 
pieces— regulating  their  magnifying  power  and  increasing  their 
diameters  so  as  to  concentrate  rays  from  the  objective,  which  are  now 
absorbed  by  the  sides  of  the  tube." 

Foreign  Mechanical  Stages. — We  described  and  illustrated  at 
pp.  712-13  (Figs.  60-1)  a  mechanical  stage  (by  Schmidt  and 
Haensch),  which  was  claimed  to  be  a  great  improvement  uj)on  other 
stages,  and  the  action  of  which,  as  regards  the  movement  of  the 
object  in  two  rectangular  directions,  and  the  proof  that  thereby  every 
part  of  the  object  must  certainly  come  into  the  field  of  view,  were 
given  with  extreme  minuteness,  as  if  the  idea  of  a  mechanical 
stage  with  rectangular  movements  had  only  now  dawned  upon 
microscopists. 

The  matter  has  now  been  carried  a  step  further,  and  we  are 
brought  somewhat  nearer  to  the  present  day  by  the  two  stages 
described  below,  and  which  are  represented  to  be  better  than  the 
English  stages  in  several  important  particulars.  As  the  descrip- 
tion *  wonld  suffer  by  any  abstract,  we  have  given  a  full  translation. 
The  writer  (Dr.  E.  Kaiser,  of  Berlin)  first  refers  to  the  above  Micro- 
scope of  Schmidt  and  Haensch.j  and  its  arrangement  for  exact 
centering  of  the  tube  whilst  focussing,  and  then  proceeds  as 
follows : — 

"  We  Germans  have  hitherto  fitted  up  our  Microscopes  in  a  most 
meagre  way  as  regards  mechanical  accessory  apparatus.  If  we  compare 
our  instruments  in  this  respect  with  those  made  on  the  other  side  of 
the  Channel,  we  must  certainly  confess  that  ours  are  far  excelled  by  the 
English  ones.  We  have  always  consoled  ourselves  for  this  with  the 
idea  that  the  numerous  mechanical  appliances  of  the  English  instru- 
ments are  really  only  playthings  which  are  never  in  any  case  necessary. 
But  nothing  is  so  erroneous  as  this  idea.  The  so-called  '  substage ' 
of  the  English,  their  provisions  for  the  fine  adjustment  and  me- 
chanical motion  of  the  object,  do  not  constitute  a  mere  plaything  in 
any  sense,  but  are  absolutely  necessary  and  indispensable  for  scientific 
investigations.  The  conviction  of  this  has  gained  ground  with  time 
more  and  more  in  oiu'  scientific  circles,  and  to  Zeiss's  manufactory, 

*  '  Bot.  Centralb].,'  i.  (18S0)  p.  728.  t  See  this  Journal,  ante,  p.  713. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  879 

under  the  excellent  theoretical  guidance  of  Professor  Abbe,  is  due  the 
credit  of  being  the  first  to  take  into  account  this  new  tendency. 

A  year  ago,  the  firm  of  Schmidt  and  Haensch  following  in  the 
footsteps  of  Zeiss,  made  improvements  in  the  Microscope,  and  in 
particular  brought  out  their  new  movable  stage. 

The  first  and  oldest  movable  stage  on  Schmidt  and  Haensch's 
model  was  placed  on  the  ordinary  stage,  and  very  much  distinguished 
itself  over  those  of  English  construction  [i.  e.  the  stage  on  j5.  713  !]  in 
being  more  simple,  and  entailing,  therefore,  a  higher  degree  of 
certainty  and  exactness  *  in  the  work.  The  motion  from  back  to  front 
was  produced  by  a  screw,  whilst  the  lateral  motion  (from  right  to 
left)  was  effected  by  a  simple  lever-movement.  This  construction 
did.  not  provide,  it  is  true,  for  the  diagonal  motion  of  the  object, 
which  is  possible  with  English  Microscopes,  but,  on  the  other  hand,  it 
afforded  what .  is  entirely  wanting  in  English  stages,  an  absolute 
guarantee  that  no  portion  however  small  of  the  preparation  can  escape 
the  attention  of  the  observer.  The  eminent  im2)ortance  of  this  in  many 
scientific  investigations  need  not  be  insisted  upon  by  us. 

One  defect,  however,  of  this  stage  of  Schmidt  and  Haensch  could 
not  be  disguised,  and  that  was  that  it  appeared  only  suitable  for 
use  with  low  powers.  All  other  objections  which  have  been  brought 
against  it,  especially  those  of  Professor  Johne  of  Dresden,t  must  bo 
met  with  the  rejoinder  that  they  are  either  empty  phrases  or,  as  the 
writer  will  prove  in  another  place,  erroneous  conclusions  drawn  from 
wrong  calculations  and  false  premises. 

Messrs.  Schmidt  and  Haensch's  manufactory  has  now  produced 
at  the  instigation  of  the  writer  and  by  the  application  of  an  idea  of 
Professor  H.  Goltzsch,  two  new  movable  stages,  which  are  free  from 
the  reproach  we  have  admitted  above,  and  which  ought  to  satisfy  all 
requirements. 

There  is  the  most  absolute  certainty,  even  when  the  highest 
powers  are  used,  that  not  even  the  minutest  part  of  the  preparation 
will  bo  passed  over ;  whilst  at  the  same  time,  like  the  Maltwood 
finder,  it  serves  to  find  again  readily  any  particular  point  of  tho 
preparation. 

An  essential  advantage  of  tho  new  stages  over  English  ones 
consists  in  the  fact  tliat,  besides  the  simplicity  and  certainty  of  their 
construction,  the  larger  one  can  also  be  used  as  a  screw  micrometer, 
and  both  allow  of  a  much  greater  use  being  made  of  the  optical  capacity 
of  the  Microscope,  on  account  of  tlieir  being  considerably  thinner  than 
the  English  movable  stages,  whereby  a  better  adjustment  of  the 
diaphragms  (c.  g.  raising  the  diajihragms  to  the  under  surface  of  the 
slide  without  using  tho  condensers)  is  rendered  possible. 

Tho  two  stages  are  designed  on  a  ccmimon  principle,  but  difier 
from  each  other  by  one  being  intended  for  rapid  work  with  low  and 
medium  powers  (uj)  to  GOO),  whilst  the  other  is  for  exact  scientific 
investigations  and  measurements,  in  which  the  highest  powers  may  bo 
used. 

*  AM  ifnlifH  ns  in  original  toxt.  t  ^''O  tliis  Jonrnal,  ante,  p.  71.S, 


880 


RECORD   OF    CURRENT    RESEARCHES    RELATING    TO 


Both  stages  arc  applied  to  the  ordinary  stage,  and  arc  held  in 
position  by  springs. 

The  lirst  stage  (Fig.  05),  which  is  the  simpler  of  the  two, 
consists,  1st,  of  a  fixed  plate  A,  with  a  coiitral  opening  B  for  the 
usual  diaphragms,  and,  2nd,  of  the  movable  plate  C,  which  turns 
about  D,  and  lias  a  larger  rectangular  opening. 

On  the  plate  C  are  two  clamps  E  J*j,  which  serve  to  fix  the  slide. 
A  sector  //'  is  attached  to  the  fixed  plate  A,  and  is  graduated  at  /'. 
The  pointer/ turns  on  II,  and  is  connected  at  D  with  the  movable 
plate  C  by  a  screw,  and  the  plate  can  therefore  be  moved  about 
the  point  I).  As  appears  from  a  simi>le  inspection  of  the  figure,  the 
pointer/ (and  with  it  of  course  the  plate  C)  can  bo  turned  about  11 

Fio.  95. 


so  as  to  fall  upon  any  particular  division  of  the  scale  /'.  The 
preparation  on  the  slide  which  is  fixed  by  the  clamps  E  E,  can  there- 
fore be  moved  its  whole  width  under  the  objective  by  means  of  the 
lever  movement  at  D,  whilst  the  examination  of  the  object  longitudin- 
ally is  efiectod  by  gradually  pushing  the  pointer / along  the  scale/'. 

If  the  motion  of  tlie  i)oint(a'/ou  the  scalo/'is  so  regulated  that 
it  moves  each  time  over  the  space  of  the  field  of  view,  and  if  after 
every  such  movement  the  pr(!2)aration  is  examined  through  its  whole 
width  by  turning  the  phito  C  about  D,  it  follows  that  every  point  of 
the  object  must  appear  in  the  field  ;  the  ai^plicability  of  this  stage  as 
a  Maltvvood  finder  is  also  thus  evident. 

To  use  the  stage,  for  instance,  for  finding  a  given  point  (e.  g.  a 
diatom-frustulo),  it  is    only  necessary  to  note  the  position  of  the 


INVEETEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


881 


pointer /on  the  scale  of/'.  Suppose  a  Pleurosigma  attenuatum  of  a 
certain  preparation  to  lie  in  the  field  when  the  pointer  /  was  on  the 
division  18  of  the  scale  /',  and  it  is  required  to  find  this  frustule 
again.  Solution  :  Put /on  the  division  18  of/',  place  the  preparation 
firmly  between  the  clanij)S  E  E,  and  turn  the  plate  C  about  D,  the 
Pleurosigma  sought  for  must  iacvitably  appear  in  the  field. 

A  great  advantage  of  this  stage  consists  in  its  enabling  the 
observer,  by  simply  taking  out  the  screw  H,  to  move  the  preparation 
about  in  any  direction  under  the  objective,  just  as  in  the  case  of  free- 
hand movement  of  the  object  with  the  ordinary  stage. 

The  second  stage  (Fig.  96),  whicli  is  the  more  complicated,  and  is 
intended  for  scientific  investigations  and  for  measuring,  is  similar  in 
construction  to  the  stage  above  described. 

Fig.  96. 


The  plate  A  is  dovetailed  into  the  microscope-stage  B,  and  by 
means  of  the  divided  screw  C  can  be  moved  longitudinally.  It  has  a 
scale  at  A,  the  divisions  on  which  correspond  to  a  revolution  of  the 
screw  C  (0  ■  25  mm.).  The  drum  of  the  screw  C  is  divided  into  one 
liundrcd  parts,  each  division  having  thus  the  value  0*0025  mm. 
Ihere  is  also  a  nonius  which  marks  the  tenth  part  of  this  value. 

On  the  plate  A  there  is  a  second  movable  plate  (on  which  is  an 
cxccntric  disk  E,  and  the  i>iece  F  for  fixing  the  slide),  movable  about 
the  screw  D  by  the  pinion  at  G,  so  that  one  minute  may  bo  read  oft' 
directly  by  means  <.f  the  scale  and  nonius. 

It  is  not  necessary  to  prove  that  the  same  jirinciple  is  involved  in 
the  construction  of  both  stages,  and  consequently  that  with  the  second 
stage  an  equally  systematic,  and  indeed  much  more  perfect  reading  ofif 
of  the  position  of  the  object  is  possible,  as  with  the  first  stage.  It  can 
also  I  e  used  in  just  the  same  way  as  a  IMaltwood  finder,  but  giving,  of 

VOL.  III.  3   M 


882 


EECORD    OF   CURRENT   RESEARCHES   RELATINa    TO 


Fig.  97. 


coi:rse,  much  greater  precision.  The  divisions  at  A  and  C,  as  also 
tlie  scale  at  G,  give  most  exact  and  close  readings  for  fixing  the  posi- 
tion of  a  given  jjoint  of  the  object,  and  the  stage  has  the  advantage 
that  the  position  of  the  point  is  referred  not  to  a  curved  line  merely, 
but  to  a  particular  portion  of  the  segment  of  a  circle  which  lies  within 
the  dimensions  of  one  field. 

When  this  stage  is  used  as  an  object-micrometer,  it  must  of  course 
(as  with  every  screw  micrometer),  be  used  in  the  direction  in  which 
the  screw  C  works.  It  is  well  only  to  commence  measuring  after 
the  screw  has  been  turned  a  little  in  the  direction  in  which  tbe 
measurement  is  being  made,  as  only  by  this  means  can  the  dead-way 
be  obviated,  which  is  unavoidable  when  a  screw  turns  backwards  and 
forwards. 

The  measurements  are  read  off  directly  from  the  divisions  at  A 
and  C.  At  A  we  have  a  value  of  0  ■  25  mm.,  at  C  of  2  •  5  ^,  and  at  the 
nonius  at  C  (to  read  which  a  lens  is  required),  a  value  of  0 '  25  /x. 

Lastly,  it  should  be  mentioned  that  an  objection  which  may 
rightly  be  urged  against  the  first  stage,  and  which  precludes  its 
use  for  exact   scientific  investigations,   is   got   rid   off  entirely   in 

the  second  form.  It  is  this  :  the 
turning  of  the  upper  movable 
plate  about  the  point  D  in  the 
first  stage  produces  somewhat 
excentric  circles ;  in  the  second 
this  is  not  the  case,  as  the  circles 
formed  about  the  point  D  are 
exactly  concentric." 

What  are  the  mechanical 
stages  of  English  construction 
which  have  found  their  way  to 
Germany,  and  to  which  the 
above  two  stages  are  so  greatly 
superior  ? 

"Fine"  Adjustments.— The 
crimes  that  are  said  to  have  been 
committed  in  the  name  of  liberty 
are,  we  think,  pretty  well  matched 
by  those  committed  in  the  name 
of  cheapness,  at  any  rate  when 
perpetrated  in  the  case  of  such 
an  instrument  as  the  Microscope. 
Fig.  97  shows  a  method  actually 
adopted  in  practice  in  a  German 
instrument  for  making  the  fine 
adjustment.  When  the  screw  m  is 
withdrawn,  the  spx'ing  seen  above 
the  mirror  presses  the  arm  attached 
to  the   stage  against   the   pillar 

of  the  Microscope,   and   the  stage    then   takes  an  oblique  position. 

When  the  screw  m  is  turned,  it  forces  the  arm  outwards,  and  thus 


INVERTEBKATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


883 


Fig.  98. 


elevates  the  stage  above  the  horizontal  position  as  much  as  it  was 
formerly  inclined  below  it. 

We  should,  have  supposed  that  whatever  advantage  might  be 
gained  by  being  able  to  use  a  high  power  with  this  instrument  would 
be  lost  by  the  defective  adjustment. 

A  still  cheaper  and  still  more  barbarous  method  is  shown  in 
Fig.  98,  in  which  the  screw  beneath  the 
stage  elevates  the  upper  of  two  plates  of 
which  the  stage  is  composed ;  the  upper 
plate  is,  however,  only  separable  from  the 
lower  plate  at  one  side,  so  that  in  this 
case  also  the  object  would  not  lie  hori- 
zontally, but  obliquely;  indeed,  by  reason 
of  its  thinness  the  upper  plate  in  our 
instrument  is  more  or  less  curved  when 
separated. 

It  is  perhaps  fair  to  note  that,  when 
literally  translated,  these  adjustments  are  described  by  the  relative 
term  of  '^  finer,"  and  that  they  are  very  cheap. 


Fig.  100. 


Fig.  99 


Fig.  101. 


Seibert  and  Krafft's  Fine  Adjustment. — It  is  claimed  for  this 
contrivauco  that  it  acts  without  friction.  Thiio  difforcnt  forms  arc 
shown  in  Figs.  91),  100,  101. 

3  M  2 


884  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

Tlio  tube  is  suspended  from  two  parallel  arras,  whose  terminal 
points  are  movably  connected  with  both  the  pillar  of  the  microscope 
and  the  tube  itself.  These  arms  with  medium  adjustment  are  exactly 
horizontal ;  but  if  the  tube  is  raised  or  lowered  by  means  of  the  micro- 
meter-screw, which  acts  upon  a  projecting  piece  between  the  arms,  the 
latter  assume  a  slightly  oblique  position.  The  movement  effected  by 
means  of  the  screw  corresponds  therefore  to  the  displacement  of  a 
parallelogram  of  which  one  side  remains  fixed  in  a  vertical  position 
while  the  opposite  side  is  slightly  raised  or  lowered,  still  preserving 
the  parallelism.  Since  the  displacement  takes  place  between  the 
points  of  eight  screws,  any  shifting  of  the  image  is  entirely  avoided, 
and  friction  is  reduced  to  a  minimum.  In  consequence  of  this  the 
micrometer-screw  turns  very  easily,  and  dead-way  is  avoided  with 
equal  resistance  on  both  ends.* 

Construction  of  Immersion  Objectives-t — The  following  note  is 
by  Mr.  Wenham,  and  we  therefore  give  it  verbatim  (with  the  wood- 
cut), though  we  are  not  sure  that  we  altogether  understand  what  is 
meant  to  be  conveyed,  especially  in  regard  to  dispensing  with  the 
use  of  oil.  No  alteration  of  the  front  of  an  objective  can,  as  it  seems 
to  us,  ever  make  a  water-immersion  objective  equal  in  aperture  an 
oil-  (homogeneous)  immersion  : — 

"  From  the  above  |  it  may  be  inferred,  that  if  the  front  of  an 
object-glass,  in  cases  when  the  aperture  is  supposed  to  be  limited  by 
water  from  rays  reflected  back  and  increased  by  an  intermedium  of  oil 
of  cedar  or  cloves,  if  the  first  surface  is  also  made  concave,  it  would  be 
the  means  of  dispensing  with  the  objectionable  use  of  oil.  I  have 
tried  some  experiments  this  way.  Fig.  102  is  the  front  lens  of  an 
p      ,f.n  immersion -jIq -inch  object-glass.     At  first  the  con- 

cave surface  of  the  front  was  made  much  shallower 
than  is  shown,  without  any  appreciable  difference 
in  effect  from  that  of  a  flat  plane.  The  concave 
was  then  deepened  till  it  reached  to^near  three 
times  that  of  the  hemispherical  back  radius,  with 
a  slightly  improved  result  in  the  way  of  increase 
of  light  and  flatness  of  field.  The  experiment  was  not  carried  further. 
The  radius  of  the  back  convex  is  "045,  that  of  the  concave  "13.  Of 
course  if  oil  of  the  same  optical  properties  as  the  glass  were  to  be 
used,  the  effect  of  the  concave  surface  would  be  simply  nil.  It  would 
then  act  like  a  flat  front." 

Mounting  of  the  Front  Lens  of  Immersion  Objectives. — Messrs. 
Powell  and  Lealand  claim  to  have  made  a  water-immersion  ^,  with 
a  numerical  aperture  of  1  •  30  or  155°  (the  theoretical  maximum  being 
1-33  or  180°). 

To  obtain  this  aperture  the  plan  described  by  Professor  Abbe  §  is 

*  Nageli  and  Scbwendener,  '  Das  Mikroskop,'  2nd  ed. 

t  '  Am.  Mon.  Micr.  Journ.,'  i.  (1880)  p.  101. 

%  A  description  of  the  construction  of  the  immersion-paraboloid. 

§  See  this  Journal,  ii.  (1879)  p.  821. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  885 

adopted.  Tho  front  lens  is  greater  than  a  hemisphere,  and  the 
surface  is  active  in  the  production  of  the  image  up  to  several  degrees 
beyond  the  equator,  so  that  the  lens  is  mounted  on  a  thin  glass  plate, 
and  the  slightly  prominent  edge  of  the  latter  fixed  to  the  brass  work  of 
the  objective. 

"  F.  R.  M.  S.,"  writing  on  this  subject,  says  :  * — "  This  plan  of 
mounting  front  lenses  on  a  thin  plate  of  glass  so  that  the  setting  need 
not  encroach  on  the  active  spherical  surface,  seems  to  have  been  known 
to  and  practised  by  the  late  Andrew  Eoss  in  connection  with  dry 
lenses.  Some  ten  years  ago  ToUes,  of  Boston,  experimented  with  this 
plan  of  mounting,  for  water-immersion  lenses.  But  I  believe  it  is 
not  on  record  that  either  Ross  or  Tolles  ever  attempted  to  utilize 
a  front  lens  beyond  the  hemisphere. 

The  first  notice  I  have  met  with,  relating  to  the  possible  use  of 
a  front  lens  greater  than  a  hemisj^here,  is  in  a  paper  '  On  the 
Question  of  a  Theoretical  Limit  to  the  Apertures  of  Microscopic 
Objectives,'  |  by  Professor  G.  G.  Stokes,  of  Cambridge.  Professor 
Stokes  there  discussed  the  question  from  a  theoretical  jioint  of  view, 
and  gave  a  demonstration,  based  on  the  assumption  that  such  a  frout 
lens  could  be  utilized,  proving  the  possibility  of  ajiertures  approxi- 
mating to  180^,  measured  in  the  body  of  the  lens. 

The  first  practical  development  of  this  idea — whether  suggested  by 
Professor  Stokes's  paper  or  not,  I  am  unable  to  say — was  projected  by 
Professor  E.  Abbe,  of  Jena  University,  and  successfully  applied  by 
Zeiss,  the  optician,  of  Jena,  under  Professor  Abbe's  direction,  to 
extend  tho  apertures  of  homogeneous-immersion  objectives  to  the 
highest  point  hitherto  attained,  1*4  numerical  ap.  (=  131°,  nearly, 
measured  in  crown  glass  of  mean  index  1  •  525). 

In  June  1879,  Professor  Abbe  brought  over  to  England  one  of 
these  high-angled  J  objectives.  He  exi)lained  at  the  R.  M.  S.  that  he 
had  found  it  necessary  to  prepare  a  special  immersion  fluid  (an 
aqueous  solution  of  chloride  of  zinc)  for  use  with  the  new  lens, 
because  he  had  not  found  it  possible  to  obtain  satisfactory  correction 
of  the  aberrations  with  any  of  the  refractive  fluids  previously  in  use. 
Even  with  the  zinc  solution  he  found  it  important  to  improve  the 
corrections  by  a  novel  chromatic  refracting  device  of  his  own  con- 
trivance, to  be  placed  immediately  below  the  eye-piece.  While  this 
immersion  medium  remained  in  the  desired  condition,  tho  definition 
obtained  with  the  lens  was  remarkably  good  ;  but,  unfortunately,  the 
solution  quickly  became  turbid  and  useless,  so  that  Professor  Abbe 
did  not  venture  to  exhibit  tho  lens  at  work  in  public.  Ho  stated  that 
the  difficulties  of  construction  would  probably  preclude  Mr.  Zeiss 
from  making  such  lenses  for  sale.  I  Lad  the  good  fortune  to  see  tho 
lens  tested  under  the  most  favourable  conditions,  and  can  aflirm  that 
it  produced  excellent  results. 

In  certain  demonstrations  conducted  by  Professor  Abbo  he  jiointcd 
out  the  fact  that  tho  now  lens  could  bo  utilized  for  proving  tho 
refractive  indices  of  various  immersion  fluids ;    for  example,   using 

*  'EiikI.  Mc'ch.,'  xxxi.  (18S0)  j>.  517. 
t  See  this  Jouiiml,  i.  (\mn)  p.  I'SJ). 


886  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

water,  he  obtained  the  precise  numerical  aperture  1*33  (=  double 
the  "  critical  angle,"  62°  58',  from  crown  glass  to  water),  &c.  With 
air  as  the  external  medium  at  the  plane-front  of  the  lens,  the 
num.  ap.  1  •  0  was  exactly  shown  (as,  indeed,  it  is  with  all  immersion 
objectives  having  num.  ap.  greater  than  1*0,  i.  e.  greater  than  cor- 
responds to  the  maximum  air-angle,  180°). 

In  applying  this  kind  of  front  lens  to  the  water  -  immersion 
system,  Messrs,  Powell  and  Lealand  have  distinctly  had  in  view  to 
extend  the  aperture  to  the  maximum  ivith  water  as  the  immersion 
medium.  The  new  ^  has  an  aperture  so  near  the  limit  (123°  out  of  a 
possible  126°),*  that  it  may  be  taken  to  exhaust  the  problem  of 
aperture — so  far  as  it  can  be  exhausted  with  the  condition  that  the 
aberrations  must  be  corrected  with  icater  as  the  inter-medium,  and  with 
that  initial  power  of  magnification.  It  is  to  be  hoped  that  a  similar 
aperture  will  be  obtained  with  a  much  higher  initial  power  of  magni- 
fication— say,  \,  yV,  Tijj  ^^^  sVj  which  will  practically  close  the  water- 
immersion  question  until  new  refracting  media  are  experimented 
with. 

There  can  be  no  doubt  that  the  development  of  the  homogeneous- 
immersion  system  is  the  problem  of  the  future  as  regards  attaining 
the  limit  of  visibility  with  the  Microscope.  In  view  of  the  success 
that  has  attended  the  construction  of  the  new  \  water-immersion, 
with  a  front  lens  greater  than  a  hemisphere,  Messrs.  Powell  and 
Lealand  have  not  hesitated  to  engage  themselves  to  construct  a 
-^V  on  a  similar  formula,  but  for  homogeneous  immersion."  The 
objective  has  since  been  completed,  and  has  an  aperture  of  142° 
(measured  in  a  crown  glass  semi-cylinder  of  mean  index  1  •  5  nearly), 
with  a  focal  distance  of  •  007  inch. 

Penetration. t — Dr.  Blackham  protests  against  objectives  with 
penetration,  the  amount  of  which  he  contends  increases  with  the 
amount  of  spherical  aberration  in  the  objective  which  has  been  left 
uncorrected,  and  decreases  in  proportion  as  the  corrections  for  sphe- 
rical aberration  approach  perfection.  Penetration,  he  maintains,  pro- 
diices  a  melting  together  or  con-fusion  of  the  images  and  a  necessary 
loss  of  definition ;  and  he  appears  to  consider  Dr.  Carpenter's  recom- 
mendation of  focal  depth  in  objectives  as  inconsistent  with  his  state- 
ment that  the  "  defining  power  of  an  objective  mainly  depends  upon 
the  completeness  of  its  corrections,  ...  an  attribute  essential  to  the 
satisfactory  performance  of  any  objective,  whatever  be  its  other  quali- 
ties." He  also  combats  the  suggestion  that  as  the  human  eye  has  con- 
siderable penetrating  power,  that  quality  must  also  be  good  for 
objectives.  He  points  out  (1)  that  the  eye  is  in  fact  possessed  of 
penetrating  power  to  a  much  less  degree  than  is  generally  suj)posed,  this 
being  confounded  with  the  power  of  accommodation,  by  means  of  which 
the  eye  can  be  successively  focussed  with  great  rapidity  upon  objects 
at  different  distances ;  and  (2)  that  the  optical  conditions  in  regard  to 
the  relative  distances  of  the  object  and  image  being  reversed,  it  does 

*  Or  \\?P  and  122°  if  the  index  is  taken  as  1-52. 
t  'Am.  Journ.  Micr.,'  v.  (1880)  p.  145. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,    ETC.  887 

not  follow  that,  admitting  a  certain  amount  of  penetration  to  bo  useful 
in  the  eye,  the  same  is  true  with  the  objective. 

As  to  the  view  that  objectives  with  penetrating  power  enable  us  to 
see  the  parts  of  objects  in  their  true  and  natural  relations,  and  that 
the  greatest  part  of  histological  work  is  being  done  with  them  to-day, 
he  replies,  "  the  more  is  the  pity,  because  most  of  it  will  have  to  be 
done  over  again  with  better  lenses."  The  fallacy  that  such  objectives 
enable  us  to  see  different  planes  of  objects  in  their  true  relations 
arises  from  confounding  depth  of  focus  with  stereoscopic  effect,  the 
latter  not  being  dependent  upon  the  former.  Diagrams  are  given  of 
two  pieces  of  wire  netting,  in  squares  of  different  patterns,  which  are 
supposed  to  be  laid  over  one  another.  "  With  a  corrected  objective 
you  see  the  upper  one  first,  and  following  nature's  plan  with  the  eye, 
you  focus  down  through  it  and  see  the  other.  If  both  are  seen  at  once, 
as  a  penetrating  objective  would  do,  we  get  a  compound  figure  totally 
unlike  either — an  illusion  of  sight." 

ToUes's  Improved  Traverse-lens,  Illuminating  and  Aperture - 
measuring  Apparatus. — Mr.  Tolles  has  improved  upon  the  traverse- 
lens  which  he  described  in  1879,*  and  his  new  apparatus  is  shown  in 
Fig.  103.     The  following  description  is  supplied  by  him  : — 

The  apparatus  being  intended  for  measurement  and  use  of  the 
largest  apertures,  a  nearly  semicircular  sector-plate  became  a  neces- 
sity. 

For  more  convenient  use,  a  small  stage  c  is  supplied,  but  this  stage 
and  its  accompanying  traverse-lens  h  are  readily  removable.  The 
traverse-lens  h  is  less  than  a  hemisphere  by  the  thickness  of  an  object- 
slide — assumed  'OS  inch. 

For  convenience  of  mounting  in  its  cell,  the  top  surface  of  h 
has  a  curvature  moderately  convex,  but  with  a  medium  of  the  index  of 
glass  connecting  the  lens  and  slide,  the  cuxwature  is  neutralized. 

When  the  object  to  be  viewed  is  in  position,  it  is  of  course  in  the 
centre  of  motion  of  the  illumination  apparatus,  as  guided  by  tlie  groove 
in  the  plate  A.  The  semicircular  rim  of  the  plate  is  graduated  to 
degrees,  and  numbered  each  way  from  the  zero  point  (midway  from 
the  ends)  to  nearly  90°. 

When  the  truncated  cone  of  glass  Tc,  having  immersion  contact 
witli  the  traverse-lens  h,  is  moved  from  zero  to  the  degree  of  obliquity 
where  the  light  fails  to  give  view  of  the  object  thrtjugh  the  objective, 
at  tlie  eye-piece  of  the  Microscope,  then  the  half  angle  of  interior 
aperture  can  be  noted  by  means  of  an  index  at  the  edge  of  the  plate  h. 
If  desirable,  the  half  angle  on  the  other  side  uf  tlie  axis  can  be  ascer- 
tained in  the  same  manner,  the  cone  h  being  first  transferred  to  the 
fitting  on  which  the  prism  n  is  shown  in  the  figure. 

The  outer  end  of  the  cone  h  can  be  cut  ott"  by  means  of  a  cup  z, 
with  a  semicircular  oi)ening  so  as  to  limit  the  light  to  an  axial  direc- 
tion in  the  cone.  For  greater  accuracy  the  apparatus  includes  an  extra 
arm  j>  and  p',  for  carrying  a  small  candle  in  tlie  tube  /  as  a  radiant, 
and  which  attaches  to  the  plate  h  in  place  of  the  prism  m.     This  arm 

*  Sec  111  is  Journal,  ii.  (1879)  p.  388. 


888 


RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 


also  carries  an  adapter  (j  for  the  reception  of  objective,  having  the 
standard  screw,  so  that  any  suitable  objective  can  be  used  as  a 
condenser. 

But  in  taking  angles  with  the  candle-radiant  in  use,  a  tube  i,  of 


A,  grooved  semicircular  plate,  h,  traverse-lens  fitted  to  stage  c.  c,  stage  on 
which  the  object  is  clamped,  d,  condensing  lens  fitting  on  k.  F,  elbow-arm 
for  attachment  of  the  whole  apparatus  to  the  substage  of  the  Microscope.  Tliis 
attachment  is  effected  by  means  of  an  adapter  y,  or  can  be  fitted  with  rack  move- 
ment, g,  an  adapter  for  auxiliary  tube,  or  to  carry  an  objective  as  a  condenser. 
h,  a  plate  on  which  is  mounted  various  apparatus  for  directing  and  condensing 
light  upon  the  object,  i,  auxiliary  tube  for  measuring  apertures,  k,  a  solid 
glass  cone,  concave  at  the  smaller  end  (for  immersion  contact  with  the  traverse- 
lens  U)  and  plane  at  the  other,  upon  which  a  condensing  lens  d  fits,  or  the  semi- 
circular diaphragm  z.  m,  a  rectangular  prism,  to  give  direction  to  the  light 
axially  upon  k  or  n.  n,  a  reflecting  prism  (acting  with  two  internal  reflections), 
to  give  very  great  obliquity  of  the  illuminating  ray  with  moderate  movement  of 
the  plate  /t  out  of  the  axial  position,  or  the  zero  position,  o,  a  hemispherical 
traverse-lens,  for  use  in  measuring  the  widest  possible  interior  angles,  with  inter- 
vening medium  of  index  1  '525  ;  it  fits  in  the  position  occupied  by  h  and  c  in  the 
figure.  /',  a  radial  arm  extending  from  the  plate  /;.  p',  arm  for  candle  fitting  iu 
tube  t.     b,  c,  k,  m,  n,  and  j),  are  removable. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  889 

some  two  inches  in  length,  is  mounted  in  this  adapter  between  the 
radiant  and  the  cone  h.  This  tube  has  only  a  narrow  central  slit 
opening  at  each  end,  which  slits  being  brought  coincident  in  direction 
with  the  candle-flame,  permit  only  a  thin  sheet  of  light  to  pass  to  the 
object.  This  restriction  of  the  incident  light,  though  not  jiractically 
important  in  taking  interior  angles,  shuts  out  anij  question  of  accuracy. 

The  extra  traverse-lens  o  is  made  a  hemisphere,  so  as  to  dispense 
with  the  object-slide ;  traverse-lens  h  and  stage  c  being  removed,  and 
lens  b  replaced  with  traverse-lens  o. 

The  object  is  mounted  on  the  plane  surface  of  this  hemispherical 
lens  under  a  cover-glass,  and  all  cemented  with  balsam  of  1  '525  index 
of  refraction,  The  cone  k  has  immersion  contact  as  before,  and  the 
cone  and  all  the  illumination  apparatus  can  be  brought  round  to  90° 
of  axial  obliquity  without  coming  in  contact  with  slide  or  stage. 

This  last-described  arrangement  of  radial-arm  and  radiant  is  espe- 
cially useful  in  taking  air  apertures  with  dry  mounted  objects  under 
view. 

My  method  is  this : — Selecting  a  cover-glass  of  |  inch  or  larger 
diameter,  I  place  at  any  marginal  part  of  the  cover  a  little  diatom- 
aceous  material,  add  a  drop  of  alcohol  to  distribute  the  same,  and 
by  burning  off  the  alcohol  the  objects  adhere  sufficiently  to  the  surface. 

This  cover-glass  is  then  to  be  cemented  to  a  slide,  not  at  the 
centre,  but  projecting  over  the  end  more  than  half  its  breadth,  the 
diatomaceous  mount  being  most  distant  from  the  slide-end.  At  about 
the  centre  of  the  slide,  another  cover  of  similar  thickness  should  be 
cemented,  so  as  to  bring  the  slide  to  parallelism  with  the  face  of  the 
back-stage  (part  of  c  in  figure)  when  placed  with  the  cover-glasses 
do\vnward  upon  it.  The  slide  is  then  moved  to  bring  the  mounted 
objects  into  the  optical  axis,  and  the  objective  focussed  upon  them, 
with  correction  in  some  way  for  cover  thickness. 

Under   these   circumstances,    witli    nothing   intervening    between 
radiant  and  object,  when  we  restrict  the   light  that  illuminates  the 
object  to  what  can  pass  through  the  narrow  slits  at 
the  ends  of  the  tubes  mounted  on  the  radial  arm  p,  ■ 

there  can  remain  no  question  of  the  obliquitij  of  the 
illuminating  rays  that  give  us  view  of  the  object ; 
for  rays  of  no  other  obliquity  are  admitted. 

Semi-cylinder  Illuminator.  —  Mr.  J.  Mayall, 
jun.,  sends  us  the  accompanying  figure,  sliowing  a 
convenient  way  of  mounting  a  semi-cylinder,  or 
prism,  &c.,  to  be  used  for  oblique  illumination  in 
the  substagc  of  those  stands  that  are  not  provided 
with  swinging  motion.  The  mounting  permits  the 
semi-cylinder  to  bo  tilted  and  placed  cxcentrically ; 
in  this  manner,  without  inmicrsiou  contact,  by 
suitable  adjustment,  the  dry  object  can  bo  viewed 
with  any  colour  of  monochromatic  light.  Placed 
in  immersion  contact  with  tlie  slide,  the  utmost 
oldiquity  of  incident  light  can  be  obtained  on  Nobcrt's  lines 
(ruled  on  the  under  surface  of  cover-glass  iu  air)  by  refraction  into 


890  EECORD   OF    CUREENT   RESEARCHES   RELATING   TO 

the  stratum  of  air,  using  a  pencil  incident  at  the  upper  internal 
surface  just  within  the  critical  angle  of  emergence — the  prismatic 
rays  of  different  refrangibility  being  then  available.  Objects  in  fluid 
may  be  placed  on  the  plane  surface  of  the  semi-cylinder  and  illu- 
minated with  ordinary  transmitted  light,  or  rendered  "  self-luminous  " 
in  a  dark  field,  as  with  the  hemisijherical  illuminator,  prism,  or 
Wenham's  immersion  paraboloid.  A  concave  mirror  with  double 
arm  is  sufficient  to  direct  the  illumination.  The  semi-cylinder 
figured  was  made  in  1875  by  Mr.  Tolles,  of  Boston,  for  measuring 
apertures.     The  mounting  was  exhibited  at  the  Society  in  1878. 

The  Iris  Diaphragm  an  Old  Invention.* — It  is  generally  st:p- 
posed  that  the  iris  diaphragm,  as  applied  to  Microscopes  and  tele- 
scopes, is  a  very  recent  invention,  but  the  following  passage,  taken 
from  an  early  volume  of  '  Nicholson's  Journal '  (1804),  shows  that  it 
is  three-quarters  of  a  century  old  : — 

"  Every  attentive  observer  must  have  taken  notice,  that  light  is  of 
as  much  consequence  to  artificial  vision  as  magnifying  power.  It  may 
therefore  afford  matter  of  surprise  that  the  most  variable  of  all  adjust- 
ments of  the  eye,  viz.  that  of  aperture,  should  never  be  introduced 
into  our  artificial  combinations.  Distant  woods,  and  other  land 
objects,  are  invisible  to  a  high  magnifying  power,  for  want  of  light, 
when  the  same  objects  may  be  distinctly  seen  with  a  lower.  By  means 
of  an  artificial  iris,  which  an  ingenious  artist  will  find  little  difficulty 
in  contriving,  this  disadvantage  in  telescopes  might  be  obviated.  Sup- 
pose a  brass  ring  to  surround  the  object  end  of  the  telescope,  and 
upon  this  let  eight  or  more  triangular  slips  of  brass  be  fixed  so  as  to 
revolve  on  equidistant  pins  passing  through  each  triangle  near  one  of 
its  corners.  If  the  triangles  be  sliddeu  in  upon  each  other,  it  may 
readily  be  apprehended  that  they  will  close  the  aperture ;  and  if  they 
be  all  made  to  revolve  or  slide  backwards  alike,  it  is  clear  that  their 
edge  will  leave  an  octagonal  aperture  greater  or  less,  according  to 
circumstances.  The  equable  motion  of  all  the  triangles  may  be  pro- 
duced either  by  pinions  and  one  toothed  wheel,  or  by  what  is  called 
snail-work." 

Microscopical  Goniometer.! — Mr.  Eutlcy,  referring  to  the 
Schmidt  goniometer  (a  positive  eye-piece  in  which  a  cobweb  is  placed 
with  a  graduated  brass  circle  and  vernier),  says  that  when  the  angles 
of  crystals  occurring  in  sections  of  rock  which  are  not  very  trans- 
lucent have  to  be  measured  by  this  instrument,  difficulty  is  often 
experienced  in  seeing  the  cobweb  distinctly,  and  this  is  one  of  the 
most  serious  drawbacks  to  the  use  of  this  kind  of  goniometer  for 
petrological  purjioses.  Its  utility  would,  he  considers,  be  increased 
if  one-half  of  the  field  were  obscured  by  the  insertion  of  a  blackened 
semicircle  of  metal  v\ithin  the  focus  of  the  eye-piece  instead  of  the 
cobweb. 

Pleurosigma  angulatum  as  a  Test  Object. — We  continually  find 
suggestions  made  in  English  and  foreign  journals  that  P.  angulatum 

*  '  Am.  Journ.  Micr.,'  v.  (1880)  p.  136. 

t  '  Study  of  Kocks  '  (8vo,  London,  1879)  p.  53. 


INVERTEBRATAj    CRYPTOGAMIA,    MICROSCOPY,   ETC.  891 

is  not  now  a  proper  test  object  for  "  high-power  "  objectives,  and  this 
view  appears  to  be  founded  on  the  fact  that  whereas  at  least  a 
^  objective  was  formerly  required  to  resolve  this  diatom,  it  can  now 
be  accomplished  by  a  7[  or  ^  inch. 

In  the  first  place,  there  is  an  error  in  the  assumption  that  resolu- 
tion is  essentially  dependent  upon  the  power  of  the  objective  instead 
of  upon  its  aperture.  A  ^  objective,  if  of  only  1  •  1  numerical  aper- 
ture, will  not  resolve  so  many  lines  to  the  inch  as  a  ^  of  1 '  15 
of  equal  quality. 

In  addition  to  this,  it  is  of  course  a  mistake  to  consider  that  the 
test  depends  upon  the  mere  fact  of  the  resolution  of  the  markings 
upon  the  object.  For  such  a  purpose,  it  is  agreed  that  no  one  would 
now  think  of  using  it.  The  real  test,  however,  is  the  manner  in  ivhich 
the  image  is  shown,  and  by  the  qualiti/  of  the  image  of  a  known  object 
the  performance  of  objectives  can  be  most  readily  determined  by 
practised  observers. 

Fasoldt's  Test  Plate.* — Mr.  Fasoldt  has,  it  is  said,  made  a  test 
plate  of  forty-one  bands  with  a  new  machine  constructed  by  him  for  the 
execution  of  fine  ruling,  and  capable  of  dividing  an  inch  into  10,000,000 
parts.  The  first  band  is  ruled  with  lines  at  the  rate  of  5000  to  the 
inch,  and  the  last  at  the  rate  of  1,000,000  to  the  inch.  After  the 
million  band,  there  are  three  "  test  bands  "  ruled  in  50,000  lines  to 
the  inch,  but  the  lines  cut  of  the  same  breadth  and  depth  as  those  of 
the  quarter  million,  half  million,  and  one  million  bands  respectively. 

We  have  not  yet  seen  any  description  of  the  plate,  our  information 
being  taken  from  an  article,  "  An  Evening  with  Fasoldt's  1,000,000 
Test  Plate,"  in  which  the  writer  is  rapturous  over  the  "  genius  who 
dared  not  only  to  project,  but  to  execute,  a  test  so  many  years  in 
advance  of  microscopical  science." 

Gunther's  Photographs  of  Pleurosigma  angulatum.f — After  the 
researches  of  Professor  Abbe  on  the  Theory  of  Microscopic  Vision  had 
placed  it  beyond  doubt  (writes  Dr.  Kaiser)  that  "  the  image  of  fine 
structures  is  not  produced  dioptrically,  but  by  the  interference  of 
diffracted  rays,"  there  could  no  longer  be  any  question  that  "  the 
interference  images  arising  from  the  action  of  diffraction  do  not  neces- 
sarily represent  the  nature  of  the  corresponding  object,"  and  therefore 
all  attempts  to  determine  the  structure  of  the  more  difficult  objects 
(as  e.  g.  diatom  valves)  by  simple  inspection  of  tlieir  microscopical 
images,  must  be  considered  a  priori  as  utterly  futile.  Rows  of 
dcprt!Ssions  will  produce  precisely  the  same  images  as  actual  stria;, 
whilst  on  tlie  other  hand,  by  striie  of  different  densities,  may  bo 
produced  the  same  interference-images  as  with  an  actual  grating. 

In  order,  tluireforc,  to  projierly  ascertain  the  structure  of  iinely- 
organized  objects,  and  especially  to  determine  the  structure  of  the 
diatom  valves  used  as  test  objects,  recourse  has  repeatidly  been  liad 
to  microphotograpliy,  which  has  proved  an  excellent  auxiliary  in  this 
department  of  micrographic  research,  and   in  addition   has  to  some 

*  '  Am.  Journ.  iMin.,'  v.  (ISSO)  p.  ICO. 
t  '  Uot.  CVntmlbl.,'  i.  (18S0)  p.  GS3. 


892  RECOBD    OP   CURRENT   RESEARCHES,   ETC. 

extent  furnished  empirical  proof  of  the  correctness  of  the  deductions 
of  our  theorists. 

Photographs  of  Pleurosigma  angulatum,  in  which  the  polygons 
ohsorved  on  the  valves  show  as  annular  de2)ressions,  have  been 
already  published  by  Stein  in  his  '  Das  Licht  im  Dienste  wissen- 
schaftlicher  Forschung  '  (Leipzig,  1877),  plate  x.  These  photographs 
were  not,  however,  taken  directly  from  the  object,  but  were  only  en- 
largements of  a  smaller  microphotograph  (reproduced  from  plate  ix.) 
made  by  photographic  apparatus  which  enlarged  it  with  a  rather 
objectionable  effect,  the  original  microphotograph  exhibiting  the 
well-known  hexagonal  markings. 

To  Mr.  Carl  Giinther,  a  photographer  of  Berlin,  the  credit  is  due 
of  having  produced  (exhibited  at  the  recent  International  Fishery 
Exhibition)  two  photographs  of  Pleurosigma  angulatum  taken  direct 
from  the  object,  which  as  regards  excellence  of  execution  are  at  least 
equal  to  the  best  productions  of  microphotography,  and  which  at  all 
events  are  calculated  to  refute  most  thoroughly  any  objections  which 
may  be  urged  against  Stein's  enlargements. 

Both  photographs  were  taken  by  a  dry  process  of  J.  D.  Moller, 
with  direct  sunlight  and  central  illumination  by  Abbe's  illuminating 
apparatus,  a  concave  lens  being  interposed.  An  old  Guudlach's 
immersion-system  No.  7  was  used,  and  with  it  one  of  the  photographs 
was  produced  with  an  amplification  of  2000  times  at  the  distance  of 
1  metre,  and  the  other  with  an  amplification  of  5900  times  at  a 
distance  of  3  metres. 

In  those  places  in  which  the  photograph  has  come  out  perfectly 
sharp  (and  consequently  in  the  centre  especially),  both  photographs 
show,  like  Stein's  enlargements,  circular  openings,  with  dark  contour 
and  bright  centre,  a  circumstance  which  characterizes  them  as  being 
without  doubt  "  openings.''' 

Where  the  i3hotogra2:)hs  are  less  sharp  (near  the  margin,  therefore) 
the  figures,  which  still  produce  the  impression  of  oijenings,  are  more 
angular,  whereby  on  a  superficial  examination  is  produced  the  appear- 
ance of  the  well-known  "  hatchings,"  running  in  three  directions. 
The  larger  photograjih  shows,  of  course,  these  marked  peculiarities 
more  clearly  and  strikingly  than  the  smaller  one. 

These  photographs,  it  is  certain,  not  only  furnish  a  fresh  proof  of 
the  correctness  of  Abbe's  theory  of  microscojiic  vision ;  but  they 
also  plainly  demonstrate  the  great  importance  of  photography  for  the 
study  of  the  more  difficult  microscopical  structures. 

New  Microscopical  Journal. — Herr  Duncker,  of  Berlin,  has  com- 
menced a  'Journal  for  Microscoj)ical  Examination  of  Flesh  and 
Popular  Microscopy '  (4to),  which  appears  twice  a  month.  The 
thirteenth  number,  which  is  before  us,  contains  articles  on  "  Schools 
for  the  Examination  of  Flesh,"  "  Micrococci  and  Bacteria,"  "  The 
Collection  and  Preparing  of  Diatoms,"  &c. 


(     803     ) 
BIBLTOGEAPHY 

OF   CUREENT   RESEARCHES   REI/ATING   TO 

INVEETEBRATA,  CRYPTOGAMIA,  MICROSCOPY,  &g. 


JOURNALS,  TRANSACTIONS,  &c.,  the  contents  op  which  are  noted 

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894  BIBLIOaRAPHY    OF 

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INVERTEBRATAj    CRYPTOGAMIA,    MICROSCOPY,    ETC.  895 

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ZOOLOGY. 

A.     GENERAL,  including  Embryology  and  Histology 
of  the  Vertebrata. 

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Beneden,  E.  Van. — Contribution  to  tlie  Knowledge  of  the  Ovary  of  Mammalia. 
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Beneden,  E.  Van,  and  C.  Julin. — Researches  on  tho  Structure  of  the  Ovary, 
the  Ovulation,  Fecundation,  and  Early  Phases  of  Development  of  the  Cheiroptera. 
Preliminary  Communication.  Bull.  Acad.  li,  Sci.  Bcly.,  XLIX.,  pp.  G2S-55. 

„  „  '       „  Observations  on  the  Maturation,  Fecunda- 

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Jen.  Zeitachr,  Natuno,,  XIV.,  pp.  458-65. 
Jruv,  C. — See  Beneden,  E.  Van. 

Koellikeu,  a. — Tlio  Development  of  the  Germinal  Layers  in  the  Rabbit. 
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896  BIBLIOGRAPHY    OF 

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Laulanie. — Observations  on  the  Origin  of  Fibrillse  in  the  Bundles  of  Connec- 
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MoBiGGiA,  A.— Three  Embryos  of  a  Fowl  in  a  single  Blastoderm.     1  plate. 

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ScHNEiDEH,  A.— On  Fertilization  of  the  Animal  Ovum. 

Zool.  Anzeig.,  III.,  pp.  426-7. 

Scott  W.  B. — Preliminary  Communication  on  the  Embryology  of  Petromyzon. 

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Yung,  E.— On  the  Influence  of  Coloured  Lights  on  the  Development  of 
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Spermatophore)  as   developed  in   species  of   this  genus  of   Indian   Helicidse. 

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INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  897 

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„         „         Oil  tiie  Sliells  of  Lake  Tanganyika  and  of  the  neighbourhood 

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WiMMEK,  A. — On  the  Mollusca-Fauna  of  the  Galapagos  Islands. 

SB.  K.  Akad.  Wiss.  Wien,  LXXX.,  pp.  465-514. 
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;^  N  2 


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VOL.  in.  3  0 


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„  „  [Powell     and     Lealand's     newest     formula 

I  Water-immersion  Objective ;  Front  Lenses  greater  than  Hemispheres  ;  the 
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„  „  [Ross's  improved  Microscope;  Swinging  Sub- 

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Eyigl.  Mech.,  XXXI.,  pp.  567-8. 
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„  „  [Powell  and  Lealand's  new -jij  Oil-immersion; 

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'  Microscopist's  Annual  for  1879.'  No.  1,  containing  List  of  Microscopical 
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MoNTUiNY,  C. — Note  on  the  Difference  in  the  Appreciation  of  the  apparent 
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Moore,  A.  Y. — Higher  Magnifying  Powers.  Am.  Journ.  Micr.,  V.,  pp.  174-5. 
"  Orderic  Vital." — The  Achromatic  Object-glass.  Engl.  Mech.,  XXXL,  j).  476. 


908       BIBLIOGRAPHY   OF    INVERTEBRATA,    CRYPTOGAMIA,    ETC. 

"Orderic  Vital."— Lens-grinding,  &c.  Engl.  Mech.,  XXXI.,  p.  619, 

Pacini,  F. — On  some  Metliods  of  preparing  and  preserving  the  Microscopic 
Elements  of  the  Animal  and  Vegetable  Tissues.     {In  part.) 

Journ.  de  Microg.,  IV.,  pp.  136-42. 
Pelletan,  J. — Immersion  Illuminators.   The  prism  of  Dr.  Woodward.     1  fig. 

Journ.  de  Microg.,  IV.,  pp.  72-6. 
„         „     The  Camera  Lucida  of  Dr.  J.   G.  Hofmann  for  Landscapes. 
1  fig.  Journ.  de  Microg.,  IV.,  pp.  76-8. 

Phin,  J. — Microscopical.     80,000  diameters. 

Engl.  Mech.,  XXXI.,  p.  469.     ^See  also  p.  518.] 
Photograph  oi  Frmtulia  saxonica. — See  Fellow,  &c. 

Powull  and  Lealand's  newest  formula  \  Water-immersion  and  new  -^-^  Oil- 
immersion. — See  Fellow,  &c. 

Ralph,  T.  S. — Annual  Address  of  the  President. 

Journ.  Micr.  Soc.  Vict.,  I.,  pp.  33-41. 

Eeddots,  C. — Cover-glasses.  Am.  Mon.  Micr.  Journ.,  I.,  pp.  123-4. 

EoGEES,  W.  A. — On  the  present  state  of  the  question  of  Standards  of  Length. 

Proc.  Am.  Acad.  Arts  ^  Sci.,  XV.,  pp.  273-312. 

EoMEO,  N.  A. — A  Eeply  to  Dr.  Blackham  and  "  Four  Inch." 

Am.  Journ.  Micr.,  V.,  p.  185. 

EoY,  C.  S.,  and  J.  Graham  Brown. — The  Blood-pressure  and  its  Variations 

in  the  Arterioles,  Capillaries,  and  smaller  Veins.     Plate  10.     [Description  of 

Methods  employed,  pp.  325-30.]  Journ.  of  F/,y.siol.,  IL,  pp.  323-56. 

Eyder,  J.  A. — Holman's  new  Compressorium  and  Moist  Chamber.     2  figs. 

A7n.  Nat.,  XIV.,  pp.  691-3. 
S.,  A.  J. — Economic  Objectives.  Engl.  Mech.,  XXXI. ,  p.  569. 

Scott,  E.  T.— Lens-making.  „         XXXIL,  p.  37. 

Sidle,  J.  W.— The  new  "  Congress  "  Turn-table.     2  figs. 

Am.  Mon.  Micr.  Journ.,  I.,  pp.  162-3. 
Smith,  A. — Microscopical  Drawings  upon  Glass.  Sci.-Gossij),  1880,  p.  183. 
Sternberg,  G.  M.— A  useful  Culture-cell.     1  fig. 

Am.  Mon.  Micr.  Journ.,  I.,  pp.  141-3. 
Stoddee,  0. — Eeply  to  Mr.  Wenhara.  Am.  Journ.  Micr.,  V.,  p.  183. 

„  „      The  ToUes-Blackham  Stand.  Engl.  Mech.,  XXXI.,  p.  546. 

Stolterfoth,  H. — On  a  simple  Method  of  cleaning  Diatoms. 

Journ.  Que/i.  Micr.  Club,  VI.,  pp.  95-6. 
"  Sunlight." — Centering  Lenses.  Engl.  3£ech.,  XXXI.,  p.  470. 

„  Leos-grinding,  &c. 

Engl.  Mech.,  XXXI.,  p.  569 ;  XXXIL,  p.  69. 
VoRCE,  C.  M. — On  Penetration.  Am.  Journ.  Micr.,  V.,  pp.  183-4. 

,,         „        CarbolicAcid  in  Balsam-mounting. 

Am.  Mon.  Micr,  Journ.,  I.,  pp.  161-2. 

W.— Finishing  Slides.  „  „  pp.  122-3. 

Ward,  E.  H. — Inaugural  Address,  including  Eemarks  on  the  Practical  Uses 

of  the  Microscope,  deliveieil  at  St.  James's  Hall,  Buffalo,  N.Y.,  August  19th,  1879. 

17  pp.     (8vo.     Indianapolis,  1S80.) 

Wenham,  F.  H. — The  Binocular  Microscope  with  Achromatized  Eefracting 
Prisms.     2  figs.  E7igl.  Mech.,  XXXI.,  pp.  500-1,  569. 

West,  E.  G. — Microscopic  Tracings  of  Lissajou's  Curves. 

Ann.  Report  S.  Loud.  Micr.  ^  Nat.  Hist.  Club,  1880,  pp.  29-30. 
White,  J.  D. — A  new  Injecting  Apparatus.     1  fig. 

Am.  Mon.  Micr.  Journ.,  I.,  p.  141. 
„        „        Improvement  in  making  Wax-cells. 

Am.  Afon.  Micr.  Journ.,  I.,  pp.  150-1. 
Woodward,  A.  L. — Eeflection  from  inside  of  the  Body-tube  of  the  Microscope. 

Am.  Journ.  Micr.,  V.,  pp.  184-5. 


H} 


T' 


W  BI-MONTHLY.  ^ 

Vol.  III.  No.  6.]  DECEMBER,  1880.  ["^  PHcltr^' 


Journal 


OF   THE 


Royal 
Microscopical  Society 

^    CONTAINING  ITS  TRANSACTIONS  AND   PROCEEDINGS, 

AND  A  RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

INVERTEBRATA,   CRYPTOGAMIA, 
MICROSCOPY,  &c. 


Edited,  under  the  direction  of  the  Publication  Committee^  by 

PRANK    CRISP,   LL.B.,    B.A.,   P.L.S., 

One  of  the  Secretaries  of  the  Society; 

WITH    THB   ASSISTANCE  OF 

A.  W.  BENNETT,  M.A.,  B.Sc.,  I  F.  JEFFREY  BELL,  M.A., 

Lecturer  oh  Botany  at  St.  Thomas' t  Hospital,  \  Professor  of  Comparative  Anatomy  in  Kin^'M  ColUge, 

AND 

S.  O.  RIDLEY,  B.A.,  F.L.S., 

Of  t lie  British  Museum, 
FELLOWS   OF   THE   SOCIETY. 


WILLIAMS    &    NORGATE, 

LONDON   AND   EDINBURGH. 


PBIMID   IV    WM.   CLOWl*    AND   «OyS,  I.IMITIID,]  [.^ITAMFOHD  STREBT    AND    CMAHINC    CROSS. 


(     2     ) 

JOUENAL 

OF  THE 

EOYAL  MICEOSCOPICAL  SOCIETY. 

VOL.  III.    No.  6. 


CONTENTS. 

TbANSAOTIONS   op   the    SoOIBTT —  PAOB 

XXIV. On  some  Structural  Features  op  Eohinostrephus  molare, 

Parabalenia  gratiosa,  and  Stomopneustes  variolaris. 

By  Charles  Stewart,  M.K.C.S.,  Sec.  E.M.S.     (Plate  XX.)     909 

XXV. On  the  Diatomaoe^  in  the  Llyn  Arbnig  Bach  Deposit. 

By  Henry  Stolterfoth,  M.D 913 

XXVI. On  a  New  Method  op  Testing  an  Object-glass  used  as  a 

Simultaneous  Condensing  Illuminator  op  brilliantly 
reflecting  Objects  such  as  minute  Particles  op  Quick- 
silver. By  G.  W.  Royston-Pigott,  M.A.,  M.D.  Cantab., 
F.R.S.,  &c.    ..  916 

Record    op    Current    Researches    relating    to    Invertebrata, 

Crtptogamia,  Microscopy,  &c.      ..  ..  ..  ..     918 

Zoology. 

Impregnation  of  file  Animal  Ovum 918 

Influence  of  Light  on  the  Development  of  Animals        918 

Origin  of  the  Nervous  System 919 

Terminations  of  Nerves  in  the  Epidermis        922 

Minute  Structure  of  Smooth  Muscular  Fibres . .      ..    _ 922 

Changes  which  Starch  undergoes  in  the  Animal  Organism 923 

Deep-toater  Fauna  of  the  Swiss  Lakes 924 

Dredgings  in  the  Bay  of  Biscay        92i 

Deep  Dredgings  in  the  Lake  of  Tiberias 925 

Fresh-water  Microscopic  Organisms 926 

Excretory  System  of  the  Cephalopoda      926 

Influence  of  Acids  and  Alkalies  on  CephaJopods 929 

'^  Liver"  of  the  Gastropoda      929 

Striated  Muscles  in  the  Monomyarian  Acephalous  Mollusca 9:^0 

Green  Colour  of  Oysters 931 

Neomenia  gorgonophilus 932 

Australian  Polyzoa 933 

Fossil  CatenicellcC  from  the  (Australian')  Miocene • .  933 

Recent  arid  Fossil  Species  of  Australian  Selenariadx 934 

Undefined  Faculty  in  Insects 934 

Nervous  System  of  Oryctes  nasicomis      935 

Activity  of  Bees 937 

Scent- organs  of  the  Male  Privet  Hawkmoth 938 

Morphology  of  the  Suspensory  Organs  of  Chrysalids      939 

Preservation  of  the  Chrysalis  from  Cold 939 

Wing-muscles  of  Insects 940 

Salivary  Glands  of  the  Odonata       941 

Mode  of  Bespiration  in  the  Larvse  of  the  Genus  Euphoea  (Libellulidx)      ..  941 

Poduridx  from  Switzerland      942 

Segments  of  the  Geophilidx       943 

Poison-organs  of  the  Spiders 943 


(    8    ) 

Ebcoed  of  Corbbnt  Rk8barohe9,  &c. — continued. 


PAOB 


Pentaetomum  polyzonum ""^^ 

Anal  Bespiration  of  the  Crustacea • 9^4 

Genealogy  of  the  Mysid^e 9^* 

Nest-building  Amphipods 945 

Development  of  Orcheslia  Montagui  and  O.  Mediterranea  ..      ..      ..      ..  946 

Structure  of  the  Eye  of  Limulua       . .      947 

Eye  of  Trilobites        948 

New  Etttomostracon  from  Afghanistan 948 

Genital  Glands  and  Segmental  Organs  of  the  Polychxta       949 

Copulatcky  Organs  of  Microphthalmus 950 

Development  and  Classifictition  of  the  Echiurida 931 

Excretory  Organs  in  the  Trematoda  and  Cestoida 954 

Ciliated  Embryo  of  Bilharzia 955 

New  Type  of  the  Cestodes 956 

New  Cestodes      956 

Solenophorus  megacephalus       957 

Histology  of  the  Tetrarhynchi 958 

Viviparous  Chirodota 958 

Observations  on  the  Temnopleuridx 958 

Abnormal  Echinids 959 

Remarkable  Form  of  Pedicellaria 960 

New  Echinodermata 961 

Synthetic  Starfish        962 

Formation  of  the  Egg-covering  in  Antedon  rosacea        963 

The  Ctenophora 963 

Medusx  and  Hydroid  Polyps  living  in  Fresh  Water 967 

Origin  of  the  Generative  Cells  in  the  Hydroida     968 

Development  of  Hydra 969 

Structure  of  Hydra 969 

IJxternal  Gemmation  in  the  Spongida  (TlateXXI.) 970 

General  and  Comparative  Morphology  of  the  Sponges 971 

New  British  Sponge    . .      . . •  972 

Infusoria  at  Parasites       972 

Chlorophyll  and  Stai'ch  in  Infusoria       973 

New  Opalinids 973 

Importance  of  Foraminifera  for  the  Doctrine  of  Descent      975 

New  Moueron      975 

Botany. 

Division  of  the  Nucleus  in  the  Pollen-Mother-ceUs  of  Tradescantia     . .      . .  976 

Multinucleated  Cells  in  the  Sunpensor  of  Dicotyledons 979 

Latex  and  Laticiferous  Vessels ..      .,      ..      ••  981 

liudlmentary  Coma  in  Godetia         981 

Nectariferous  Trichomes  of  Melampyrum       982 

Threads  of  Protoplasm  on  Glandular  Uairs  of  Silphium 982 

Besin-passages  in  the  Coniferx         983 

Infiuejice  of  Light  on  the  Transpiration  of  Plants 983 

Heliotropism       984 

Formation  of  Chlorophyll  in  the  Dark 984 

Chlorophyll  in  the  Leaves  of  tlie  Canada  Vine       ..  985 

Absorption  of  Water  by  the  Leaves  of  Bulbous  Plants 9;'>5 

Disengagement  of  Carbonic  Acid  from  the  Boots  of  Plants 985 

Digestive  Principles  of  I'lanta 986 

Nutrition  of  the  Droscra 986 

Botanical  Micro-Chemistry       986 

Bed  Pigment  of  the  Flowers  of  the  Peony       987 

Development  of  the  Sporangium  in  Vascular  Cryptogams     .. 987 

Structure  of  the  Stem  of  Mosses 989 

Stomata  of  Marchantiacex        990 

Infloresrence  of  the  Marchantiacem 9;»1 

New  Hepaticv     9lt2 

Observatitms  on  Urcdineie  and  Ustilaginete     992 

Uredo  viticida 9!>3 

Development  of  the  Spsrmogonia  of  JHcidiomycetea      993 


(  4  ) 

Keoobd  op  Current  Eesbarohes,  Ac. — continued. 

PAOB 

Infection  of  Puccinia  Malvacearum       994 

Alternation  of  Generations  in  Gymnosporangium        995 

Conidial  Apparatus  of  Pleurotus  ostreatus 996 

Plychogaster  albus,  Cord.,  a  Form  of  a  Polyporiis      .,      . .      996 

Synchytrium  parasitic  upon  Dryaa        996 

New  Vine-disease     997 

Clover-disease  in  Sweden        997 

Salmon  Disease        997 

Biology  of  the  Schizomycetea 998 

Influence  of  Schizomycetes  on  the  Development  of  Yeast     1000 

New  Microscopic  Schizomycetes      ..      ..      ..      ..      ..      1001 

Social  Bacteria        1001 

Development  and  Fermenting  Power  of  Bacteria , .      . .  1005 

Effect  of  Putrefactive  Changes  on  Bacteria 1006 

Theory  of  Virulent  Diseases  and  the '^ Fowl-Cholera" 1006 

Fowl-Cholera  and  " Sleep  Disease"      1012 

Fowl- Cholera  and  Anthrax 1013 

Etiology  of  Anthrax 1013 

Anthrax^— Its  Spread  and  Prevention     ..      1015 

Immunity  from  Anthrax  obtained  hy  Inoculation 1016 

Identity  of  Bacillus  anthracis  and  Ray-Bacillus        1018 

Bacteria  in  Ear-disease,  &c ..  1020 

^^Hysterophymes"  of  Starch  and  Fat 1020 

Carpozyma,  the  Ferment  of  Wine 1020 

Morphology  of  Lichens :  Endophloeal  Species  of  Polyblastia ;  Epiphora ; 

Magmopsis 1021 

Application  of  Pringsheim^s  Researches  on  Chlorophyll  to  the  Life  of  the 

Lichen       1022 

AgardKs  '  Morphologia  Floridearum' 1022 

Oxyglossum,  a  new  Genus  of  Laminariaceas  .,      1022 

New  Endophytic  Alga      1023 

New  Genus  of  Oscillatorieie     ..      ..      1023 

Change  of  Colour  in  OsciHatorieas 1023 

Cell-division  in  Conferva  and  (Edogonium 1024 

Incrusted  Filaments  of  Conferva • 1024 

Germination  of  the  Zoospores  of  (Edogonium      1025 

Codiolum  gregarium,  A.  Br 1026 

Algse  from  the  Amazons 1026 

Fossil  Diatoms 1026 

Dimystax  Perrieri,  new  Ciliated  Organism  containing  Chlorophyll  ..      ..  1026 

MicBOScopy,  &c. 

Permanent  Microscopical  Preparations  of  Amphibian  Blood     1028 

Preparing  and  Mounting  Wings  of  Micro-Lepidoptera      1029 

Microscopical  Investigation  of  Wood 1030 

Permanent  Preparations  of  Plasmodium      1030 

Preparation  of  Green  Algm 1031 

Slides  from  the  Naples  Zoological  Station 1031 

^eroscqpe«  (Figs.  105  and  106)      1032 

Microscopical  Appearance  of  the  Valves  of  Diatoms  (¥ig,  107) , 10:^3 

Cleaning  Diatoms  with  Soap 1034 

Separation  of  Heavy  Microscopic  Minerals 1034 

Pearson-Teesdale  Microtome  (Figa.  lOS  &nd  lOd)       1034 

Hailes' Poly-microtome  (FigB.  110  aad  111) 1036 

Salicylic  Acid  as  a  Preservative      1037 

Dry  "■  Mounts"  for  the  Microscope 1038 

Wax  Cells 1039 

Improvement  in  Making  Wax  Cells       1040 

Atwood's  Rubber  CeU  (Fig.  112) 1041 

Parhes's  Frog-plate  (Fig.  113)        1041 

Sternberg's  Cultwre-celllFig.  lU) 1042 

Apertures  exceeding  180°  in  Air 1043 

Visibility  of  Minute  Objects — New  Medium  for  Mounting  (Monohromido 

of  Naphthaline)        1043 


JOTIRN.Tl  ICCR.  SOC.TOLIEPL.S?: . 


C/StewiTcrfc  cL&b. 


P e a^G  ella.T'iae  &.e  .  of  Eelmiostpepli-us  xnola3?e. 
Pa-rasalexiia.  a-xicL  Stoxaopneiistes. 


JOURNAL 

OF    THE 

ROYAL  MICROSCOPICAL  SOCIETY. 

DECEMBER,  1880. 


TRANSACTIONS  OF  THE   SOCIETY. 


XXIV. — On  some  Sti'uctural  Features  of  Echinosirej^Jius  molare, 

Parasalenia  graliosa,  and  Stomojmeustes  variolaris. 

By  Chaeles  Stewaet,  M.E.C.S.,  Sec.  E.J\I.S. 

(JRead  10th  November,  1880.) 

Plate  XX. 

EchinoBtreplius. — This  genus  differs  from  all  other  Desmosticha 
in  the  form  of  its  corona,  which  is  broadest  near  the  abactinal  pole, 
with  the  mouth  situated  at  the  extremity  of  the  opposite,  more 
pointed,  region.  The  flattened  abactinal  surface  bearing  spines  far 
exceeding  in  length  those  of  other  parts. 

These  exceptional  features  give  greater  interest  to  the  other 
points  in  its  structure,  which,  in  some  respects,  are  as  remarkably 
difi'erent  from  other  forms  as  the  coarser  characters. 

Genital  glands. — These  are  abundantly  crowded  with  spicula, 
those  in  the  parts  of  the  branches  nearest  the  common  duct  being 
in  the  form  of  perforated  plates,  often  of  large  size,  and  identical 
in  all  respects  with  those  found  in  the  genus  PhyUac<(nthus 
amongst  the  Cidaridae;  but  mixed  with  these,  and  replacing  them  at 
the  tips  of  the  branches,  are  numerous  bihamate  spicula,  such  as  are 
so  widely  distributed  amongst  the  Echinometradae  and  Echinidte. 
The  greatly  varied  spicular  forms  in  Echinometra  lucunter  some- 
what approach  to  this  condition,  but  in  it  the  perforated  plates 

explanation  op  plate  XX. 

Fig.  L — Portion  of  genital  gland  of  Echinostrcphns  molare. 

„     2. — Si(](!  vifw  of  jiiw  of  geminiform  pedicellaria  oi  Echinostrephus. 

„     S. — Ditto  viewed  fi'Am  witliin. 

„     4. — Jiiw  of  ophioce])li;tlons  \^(ii\\cc\\;ma,  oi  Echinostrephus. 

„     5. — Jaw  of  tridact\  le  pfdioelluriii  of  Echinostrcjihus. 

„     6. — Sido  view  of  jaw  of  gemmiforiii  pedicellaria  of  Parasalenia. 

„     7. — Ditto  viewed  from  witliin. 

„     8. — Spicula  from  aml)td:icial  tulie  of  Parasalenia. 

„     9.— Jaw  of  n|ilii()Oipliulou.s  pi  dicellaria  of  Slomnpncustcs. 

„  10. — Jaw  of  tridartylc  |)eilii-ellaria  of  I'^tomojmeustc.t. 

No.  S  niiignifle.l  :;".:;  cii:mi ,  tlio  rest  7,'i  diam. 
vol  .   111.  ':)    V 


910  Transactions  of  the  Society. 

are  very  different,  and  are  apparently  derived  as  a  modification  of 
either  simple  bihamate  or  biacerate  spicula. 

From  each  genital  opening  protruded  a  cylindrical  mass  of 
generative  products,  apparently  surrounded  and  held  together  by  a 
thin  membrane.  May  this  not  be  a  provision  favouring  the  passing 
of  the  ova  or  spermatozoa  beyond  the  long  spines  of  this  region  ? 

Pedicellariae. — The  gemmiform  pedicellarise  resemble  in  all 
essential  points  those  of  EcJmiometra  and  Heterocentrotus.  The 
jaw  terminates  in  a  long,  deeply  grooved  fang ;  the  groove,  which 
is  almost  converted  into  a  canal  by  the  meeting  of  its  margins, 
opening  at  a  point  near,  but  never  at,  the  tip  on  the  external  or 
distal  surface.  A  long,  solid  fang  rises  close  to  the  terminal  one, 
but  nearer  the  base  of  the  jaw,  and  usually  on  the  right  side.  The 
expanded,  wing-like  portion  of  the  jaw  is  deeply  notched  on  its 
distal  border.  This  character  of  the  terminal  fang,  in  conjunction  with 
the  two  glandular  masses  attached  to  each  jaw,  lead  me  to  think 
that  these  pedicellarise  have,  amongst  other  functions,  that  of  intro- 
ducing a  poison  into  any  wound  they  inflict. 

The  gemmiform  pedicellarise  are  of  two  sizes,  one  about  two- 
thirds  that  of  the  other. 

There  is  nothing  remarkable  about  the  tridactyle  pedicellariaa. 
The  serrate  borders  of  the  prongs  are  widely  separated,  especially 
near  the  distal  extremity,  which  is  somewhat  spoon- shaped ;  they 
come  in  contact  with  one  another  by  this  part,  which  forms  about 
two-thirds  of  the  entire  length  of  the  jaw.  The  sides  of  the  prong 
are  pressed  in  forming  a  crest  running  the  whole  length  of  its  outer 
surface. 

The  ophiocephalous  and  trifoliate  pedicellarise  are  similar  to 
those  of  most  Echinometradae  and  Echinidae. 

The  ambulacral  tubes  have  the  usual  bihamate  spicula,  but 
much  varied  in  size  and  thickness. 

Parasalenia, — This  genus,  which  at  first  sight  looks  so  like  an 
ordinary  Echinometra,  differs,  as  has  been  already  pointed  out,  in 
the  arrangement  of  its  pores,  and  in  its  anal  plates — the  latter 
resembling  those  of  Arbacia. 

Spines. — These  are  unlike  those  of  any  other  of  the  Echino- 
metradae in  showing  no  evidence  of  periodicity  of  growth,  such  as  is 
met  with  in  the  rest  of  that  family.  The  calcareous  wedges,  which 
radiate  from  the  interior  of  the  spine,  remaining  for  a  long  time 
thin,  and  separated  by  a  space,  rather  broader  than  themselves, 
occupied  by  the  usual  calcareous  network.  Near  the  surface  of  the 
spines,  the  wedges  somewhat  suddenly  become  much  thickened,  so 
as  nearly  to  come  in  contact.  Their  substance  is  peculiar,  in 
presenting  in  sections  a  regularly  dotted  character,  reminding  one 
of  the  markings  of  striped  muscle.  They  show  no  peculiarity  under 
polarized  light. 


Echinostrephus  molare,  &g.     By  C.  Stewart.  911 

Pedicellarire. — The  pedicellariae  are  very  scantily  present.  The 
gemmiform  variety  is  remarkable  for  the  complete  absence  of  the 
secondary  solid  fang  found  in  Echinometra,  Heterocentrotus,  and 
in  some  members  of  the  genus  Strongylocentrotus.  There  is  a 
slight  bulging  to  the  right,  at  the  base  of  the  teraiinal  fang,  but  it 
shows  no  trace  of  a  spine.  This  feature  is  of  interest,  as  the 
terminal  with  one  basal  fang  is  held  by  M.  E.  Perrier  to  be 
characteristic  of  the  Echinometradae,  to  which  family  most  would, 
I  should  think,  refer  Parasalenia.  The  tridactyle  form  is  exceed- 
ingly delicate,  and  I  was  unable  to  obtain  any  perfect,  nor  could 
I  find  any  of  the  other  varieties. 

The  spicula  of  the  ambulacral  tubes  are  unlike  any  that  I  have 
found  in  other  JJesmosticha.  They  are  biacerate,  and  generally 
slightly  bent  in  the  centre.  Their  concave  side  is  usually  provided 
with  two  often  bifid  spinules.  It  would  be  interesting  to  know 
the  structure  of  the  viscera.  Unfortunately  my  specimen  was 
thoroughly  cleaned  out  and  dry. 

Stomopneustes. — This  genus  is  interesting  as  often  showing  con- 
siderable varieties  in  the  form  of  the  corona,  which,  though  usually 
circular,  is  sometimes  elliptical.  It  is  remarkable  also  for  the  size 
and  structure  of  the  spicula  of  its  ambulacral  tubes,  the  spicula 
being  equally  well  developed  in  a  specimen  of  1  inch  diameter  as 
in  one  of  4.  These  alone  suffice  to  determine  the  genus,  but  as 
they  have  been  already  described  and  figured,  I  will  not  further 
allude  to  them. 

Pedicellariae. — The  ophiocephalous  form  is  very  abundant,  and 
they  at  once  call  attention  from  their  large  size.  Their  jaws  are 
more  powerfully  toothed  than  in  any  other  genus  I  have  examined, 
but  are  most  remarkable  for  being  borne  almost  directly  on  the 
calcareous  stem.  The  muscular  intervening  portion,  usually  so 
long,  being  in  this  case  almost  entirely  absent,  causes  them  to 
resemble  at  first  sight  the  gemmiform  variety.  Those  of  the 
peristomal  membrane  are,  however,  of  the  ordinary  character  met 
with  in  Echini  generally.  I  was  unable  to  find  any  gemmiform 
pedicellariae,  though  I  examined  many  specimens  with  great  care. 

The  tridactyle  form  is  short,  and  varies  greatly  in  size.  They 
are  broad,  and  when  the  jaws  are  closed  the  whole  length  of  their 
finely  serrate  edges  come  in  contact.  The  crest-like  septum  on  the 
inner  surface  of  the  bo.dy  of  the  jaw  is  prolonged  as  an  irregular 
crest  on  the  inner  surface  of  the  spoon-shaped  prong  of  the  jaw 
nearly  to  its  tip.  The  great  variation  in  the  size  of  these  pedicel- 
lariae, and  tlie  broad,  spoou-shajied  charat'tor  of  their  jaws  make  the 
smaller  forms  closely  resemble  the  trifoliate  variety,  and  lend 
weight  to  Professor  Agassiz's  view,  that  the  latter  are  rarely 
stages  of  the  former.  But  what  I  take  hero  to  bo  the  trifoliato 
form,  although  of  the  same  dimensions  as  the  smallest  tridactylcs, 

3  p  2 


912  Transactions  of  the  Society. 

show  no  indication  of  the  peculiar  crest  described,  and  differ  also  in 
some  other  particulars. 

In  conclusion,  I  may  say  that  it  seems  to  me  most  desirable 
that  minute,  and  even  apparently  trivial,  features  should  be  given  in 
the  descriptions  of  species,  and  that  when  this  is  more  done  we  may 
find  affinities  between  forms  we  should  otherwise  not  suspect,  and 
be  enabled  by  the  examination  of  even  an  ambulacral  tube  or  pedi- 
cellaria,  &c.,  to  determine  a  species  without  the  denudation  of 
portions  of  the  corona,  which  is  sometimes  not  desirable. 


(    913     ) 

XXV. — 071  the  Diatomaceee  in  the  Llyn  Arenig  Bach  Deposit. 
By  Henry  Stolterfoth,  M.D. 

iBead  13th  October,  1880.) 

Having  been  for  some  time  past  engaged  in  examining  diatoma- 
ceous  deposits,  most  of  them  from  foreign  countries,  many  from 
places  one  has  small  chance  of  visiting,  it  was  with  no  little  interest 
I  heard  of  the  discovery  made  by  Mr.  W.  F.  Lowe,  of  the  Arenig 
Bach  deposit.  I  only  know  of  one  other  diatomaceous  deposit  in 
North  Wales,  mentioned  by  Smith  in  his  '  British  Diatomaceae '  as 
Dolgelly  earth,  but  which  I  have  obtained,  though  only  in  small 
quantities,  and  from  some  feet  below  the  surface  of  the  water,  at  a 
lake  called  Cwm  Bychan,  fifteen  miles  from  Dolgelly. 

In  October  1879,1  accompanied  Mr.  W.  F.  Lowe  and  a  few  friends 
to  the  Arenigs.  We  had  a  wet  day,  and  lost  some  time  in  finding 
the  lake,  which  lies  nine  miles  from  Bala,  amidst  the  mountains. 
On  reaching  it,  we  found  that  it  had  been  drained  to  the  extent  of 
about  twelve  feet  below  its  normal  level,  so  that  about  one-third  of 
its  surface  was  dry.  The  edge  of  the  lake  for  about  ten  yards 
consisted  of  stones  from  the  surrounding  mountains,  which  are  of 
igneous  origin.  The  remainder  of  the  uncovered  surface  that  we 
were  able  to  examine,  was  covered  with  about  one  foot  of  peat,  and 
under  this  was  the  diatomaceous  material,  also  about  one  foot  thick. 
A  small  stream  at  the  head  of  the  lake  had  cut  a  section  through 
the  peat  and  diatoms,  and  the  latter  rested  directly  on  the  rocky 
bottom.  This  partial  inspection  of  the  bed  of  a  mountain  lake, 
more  than  repaid  the  trouble  of  getting  to  it,  for  not  only  is  it 
something  to  have  seen  a  deposit  in  situ,  and  to  have  handled  and 
examined  it  in  more  than  microscopic  quantities,  but  it  enabled  me 
to  get  my  specimens  from  different  positions  as  naturally  deposited, 
an  important  point  if  we  are  ever  to  determine  the  time  during 
which  a  deposit  has  been  forming,  and  the  changes  that  may  have 
taken  place  with  regard  to  species. 

This  much  I  think  we  may  say  with  regard  to  the  Arenig 
deposit,  that  the  diatoms  have  been  collecting  at  the  bottom  of  the 
lake  ever  since  the  last  glacial  period,  and  although  the  deposit  was 
only  a  foot  thick  where  we  examined  it,  it  is  probable  that  in  the 
centre  of  the  lake  it  is  much  thicker. 

It  now  remains  for  mo  to  speak  more  pai-ticularly  of  the 
diatoms. 

For  the  purpose  of  a  systematic  examination,  I  made, 

1st.  (liatliorings  of  as  many  growing  forms  as  I  was  able,  in 
and  about  the  lake. 

2nd.  I  took  some  of  the  peat  immediately  above  the  deposit. 

3rd.  A  portion  of  the  de}X)sit  Ix^Iow  tlie  poaf. 


914 


Transactions  ofihe  Society. 


4th.  A  portion  from  the  middle  of  the  deposit. 

5th.  A  portion  from  the  lowest  part  of  the  deposit. 

All  these  collections  I  kept  carefully  separated,  and  having 
cleaned  and  examined  them,  I  have  arranged  them  in  five  columns, 
marking  the  relative  abundance  of  each  species.  One  asterisk,  marks 
very  rare;  two  asterisks,  rare;  three  asterisks,  common;  four 
asterisks,  abundant. 

List  op  Diatomacejs  from  Llyn  Arenig  Bach. 


1 

2 

3 

4 

5 

Recent. 

Peat. 

Top. 

Middle, 

Bottom. 

Navicula 

nobilis  Ehr 

** 

**** 

**** 

**** 

**** 

major  W.  Sm 

** 

**** 

**** 

**** 

*if** 

divergens  W.  Sm 

** 

*** 

*** 

*** 

*** 

mesolepta  Ebr 

** 

** 

** 

viiidis  W.  Sm 

*** 

*** 

** 

** 

gibba  Ehr 

*** 

*** 

*** 

*** 

*** 

rhomboides  Ehr 

*** 

**** 

*** 

** 

*** 

Berians  Kiitz 

*** 

**** 

**** 

**** 

** 

acuta  W.  Sm 

**■ 

** 

firma  Kiitz 

* 

** 

gracillima 

** 

*** 

*♦* 

** 

** 

cryptocephala  Kiitz 

** 

alpina  W.  Sm 

** 

*** 

*** 

lataW.  Sm 

* 

bacillaris  Greg 

** 

** 

afSnis  Ehr 

** 

** 

acuminata  W.  Sm 

* 

*» 

Tabellaria 

flocculosa  Kiitz. 

♦*** 

*** 

** 

fenestrata  Kiitz 

***» 

Eunotia 

diadema  Ehr 

*** 

**** 

**** 

** 

** 

tetraodon  Ehr 

** 

** 

** 

** 

incisa  Greg 

**** 

**** 

**** 

** 

** 

camelus  Greg 

* 

Epithemia 

alpestris  W.  Sm 

* 

* 

Himantidium 

bidens  Ehr 

** 

*** 

** 

*** 

*♦ 

glacile  Ehr 

*** 

** 

** 

*♦ 

undulatum  W.  Sm 

*** 

**** 

*** 

*** 

**** 

majus  W.  Sm 

** 

* 

** 

» 

Synedra 

radians  W.  Sm 

*** 

Cocconeis 

placentula  Ehr 

♦ 

Melosira 

orichalcpa  W.  Sm 

*** 

**** 

*** 

** 

nivalis  W.  Sm 

** 

*** 

*** 

**** 

**** 

spinosa  W.  Sm 

**** 

*** 

Cymbella 

scotica  W.  Sm 

** 

*** 

*** 

** 

** 

maculata  Kiitz 

** 

** 

♦  * 

cuspidata  Kiitz 

** 

Llyn  Arenig  Bach  Deposit,  d'c.     By  Ilenry  Stolterfoth.      915 


Nitzschia 

tenuis  W.  Sm 

Stauroneis 

gracilis  Ehr 

ancepa  Ehr 

Burirella 

biseriata  Do  Breb 

splendida  Kiifz 

linearis  W.  Sm 

Gomphonema 

acuminatum  Ehr 

dichotomuin  Kiitz 

Pleurosigma 

lacustro  W.  Sm 

Cymatoplenra 

solca  W.  Sm 

Odontidium 

mutabilo  W.  Sm 

Fragilaria 

capucina  Dem 

1              2 

Recent.          Peat. 

3              4 

Top.            Middle. 

5 

Bottom. 

* 

** 
** 
*♦ 

* 

* 

* 
** 

*** 

** 
** 

**♦♦ 
** 

♦♦ 

* 
** 

Total  number  of  species 

32 

38 

29 

26 

25 

The  result  arrived  at  from  the  examination  of  this  list  proves 
that  no  species  has  existed  in  the  lake  which  is  not  now  a  living 
form  in  some  place  or  other,  while  I  was  able  to  gather  in  a  short 
time  more  living  species  than  are  to  be  found  in  any  part  of  the 
deposit  except  the  peat.  The  large  forms  of  diatoms  do  not 
appear  to  have  sunk  to  the  bottom,  but  are  spread  uniformly 
throughout  the  deposit. 

One  of  the  variations  amongst  the  larger  forms  of  diatoms  is 
marked  by  Surirella  biseriata  being  abundant  at  the  top  and 
middle  of  the  deposit,  while  replaced  at  the  bottom  by  Surirella 
splendida,  and  as  we  go  down,  Melosira  nivalis  becomes  more 
abundant,  also  Gomplwnema  acuminatum. 

It  would  be  a  great  advantage  if  more  was  known  of  the 
relative  thickness  of  diatomaceous  deposits,  and  the  position  of  our 
specimens  in  situ,  for  from  this  wo  might  learn  something  of  the 
way  in  which  one  species  replaces  another. 

Such  an  immense  mass  of  minute  forms  as  are  collected  at  the 
bottom  of  Llyn  Arenig  Bacb,  point  to  the  fact,  that  a  long  quiet 
age  has  passed  since  the  lake  was  formed.  How  long,  as  yet  no 
man  can  sjiy. 

This  spring  (1880)  I  liavc  again  visited  tlio  spot  with  <lie  hope 
of  making  a  more  careful  examination  ;  but,  alas  !  I  found  the  lake 
again  full,  and  all  the  wondrous  deposit  at  least  ten  foct  below  the 
surface ;  and  unless  something  goes  wrong  with  the  ]>ala  water- 
works, there  is  little  chance  that  human  eye  will  again  rest  on  what 
may  bo  termed  one  of  the  secrets  of  the  deep. 


916  Transactions  of  the  Society. 


XXVI. — On  a  New  Method  of  Testing  an  Ohject-glass  used  as  a 
Simultaneous  Condensing  Illuminator  of  hrilliantly  reflecting 
Ohjects  such  as  minute  Particles  of  Quicksilver.  By  G.  W. 
KoYSTON-PiGOTT,  M.A.,  M.D.  Cantab.,  F.K.S.,  &o. 

(Bead  ISth  November,  1880.) 

The  recent  advances  made  in  object-glass  illumination  in  America, 
induce  me  to  describe  some  results  obtained  nearly  two  years  ago. 
These  results  surprised  me  very  much  at  the  time,  and  led  me  to 
believe  an  infallible  test  had  at  length  been  discovered.  Some  of 
the  phenomena  are  truly  remarkable,  and  were  at  first  extremely 
puzzling.  They  appeared  to  present  a  new  order  of  diffraction 
rings  of  exquisite  precision  and  beauty  of  arrangement. 

The  apparatus  employed  consisted  of  some  excellent  |ths  and 
T^^ths.  A  Smith  illuminator,  consisting  of  a  disk  of  glass  placed  at 
45°  in  the  optical  tube,  illuminated  the  objects  by  horizontal  rays. 
The  object-glass  then  condensed  the  flame  upon  the  stage. 

Mercurial  globules,  forced  by  a  piston  through  a  leather  bag 
contained  in  a  glass  syringe,  were  formed  extremely  clean ;  these 
were  then  continuously  smashed  with  a  steel  spring ;  examined ; 
selected  ;  and  secured  under  a  glass  cover. 

Viewed  with  dry  lenses,  extraordinary  forms  appeared.  Minute, 
flat,  circular  mirrors  (mirrorlets),  spherical  globules  adhering  to  the 
upper  glass,  and  particles  adhering  to  the  lower  glass  slide.  The 
latter  varied  through  many  sizes,  and  each  presented  brilliant 
rings  in  the  sharpest  focal  plane  of  remarkable  appearance,  totally 
difierent  from  anything  seen  before. 

Diffraction  rings  for  a  corrected  glass  are  almost  entirely  either 
outside  or  inside  the  focal  plane.     These  were  hi  it. 

The  diameter  measured  by  micrometer  (reading  to  ^pg-^^j^^ths)  was 
nearly  in  every  case  nine-tenths  of  the  diameter  of  the  globule.  In 
many  an  exact  image  of  the  flame  presented  edgeways  was 
accurately  depicted. 

On  the  plane  side  of  the  circular  little  mirrorlets  could  be 
seen  occasionally  black  points,  clustering  more  or  less,  of  a  minute- 
ness surpassing  all  previous  observation :  dealing  an  astounding 
blow  against  the  microscopic  dogma  of  a  hundred  thousandth  of  an 
inch  being  the  limit  of  vision,  "  light  being  too  coarse  a  thing  to 
show  anything  less  than  half  a  wave-length."  But  more  of  this 
anon. 

Another  order  of  phenomena  is  differently  produced.  In 
order  to  preserve  the  mercurial  particles  from  premature  tarnishing, 
drops  of  liquid  were  introduced ;  my  astonishment  was  great  to  find 
that  the  brilliant  rings  were  now  diminished  to  one-ninth  their 


Testing  an  Ohject-glass,  &g.     By  Q.  W.  Royston-Pigoii.    917 

former  size :  they  had  just  been  nine-tenths  the  globule  diameter, 
they  were  now  one-ninth  1 

Selecting  globules  about  the  100,000th  of  an  inch — (easy  of 
representation  by  separating  the  spider  lines)  under  a  power  of 
1000 — by  searching  the  illuminated  field,  the  tiny  illumination 
could  still  be  caught  by  the  best  glasses  I  possessed.  The  exquisite 
truth  of  these  reflections  by  condensing  the  light  down  upon  the 
objects  through  the  object-glass,  forms  the  most  thoroughly 
searching  and  infallible  test  of  the  excellence  of  a  glass  with  which 
I  am  acquainted. 

For  some  months  a  series  of  observations  more  and  more 
confirmed  me  in  this  opinion. 

The  manipulation  is  somewhat  delicate  ;  the  hght  or  flame 
must  be  placed  so  that  its  distance  measured  by  the  path  of  the 
illuminating  rays  shall  equal  nearly  the  distance  of  the  eye  from 
the  stage.  If  immersion  liquids  are  used,  those  globules  must  be 
selected  which  appear  brilhantly  illumined  on  an  intensely  black 
ground.  I  have  used  a  tin  cylinder  somewhat  contracted  at  the 
top  and  perforated  with  a  pigeon-hole  aperture  to  project  the 
illuminating  rays  horizontally.* 

A  transcend ently  fine  diff'racting  ring  of  light  of  the  most 
astounding  attenuation  may  be  discovered  with  the  finest  glasses, 
appearing  much  finer  than  the  spider  lines  of  the  micrometer,  the 
thinnest  of  which  is  the  10,000th  of  an  inch  mounted  by 
Mr.  Browning.  Now  what  this  represents  on  the  stage  when  an 
object-glass  magnifies  1000  times  to  the  eye,  I  leave  my  friends  to 
calculate  for  themselves.  But  many  persons  have  agreed  with  mo 
that  it  looked,  though  then  enlarged  a  hundred  times,  much  finer 
than  the  web  in  question. 

Practical  opticians  know  full  well  the  extreme  difficulty  of 
viewing  mercurial  globules  under  very  high  power,  and  brightly 
illuminated  by  oblique  rays. 

Tins  method  shows  true  images  of  such  surprising  distinctness 
and  incredible  reduction  as  almost  to  defy  adequate  description. 

I  had  the  pleasure  of  exhibiting  these  appearances  to 
Mr.  Stephenson  last  spring,  and  to  Mr.  Curties  recently. 

*  Tlio  polished  tin  entirely  stops  tlie  radiation  of  heat  upon  the  observer's  head, 
which  is  sometimes  somewhat  near  the  illuminator. 


(  918  ) 
RECORD 

OF  CURRENT  RESEARCHES  RELATING  TO 

INVERTEBEATA,  CRYPTOGAMIA,  MICROSCOPY,  &c.* 


ZOOLOGY. 


A.    GENERAL,  including  Embryology  and  Histology 
of  the  Vertebrata. 

Impregnation  of  the  Animal  Ovum.f — Professor  Schneider  states 
that  the  impregnating  spennatozoa  disappear,  either  by  breaking  up 
into  small  pieces  or  by  uniting  to  form  nucleated  spherules,  which 
gradually  diminish  and  disappear.  The  observations  on  which  this 
statement  is  based  were  made  on  the  eggs  of  Aulostomum,  Nephelis, 
Piscicola,  and  Mesostomum  Ehrenhergii.  In  Aulostormim  and  Piscicola 
there  were  hundreds,  in  Nephelis  thousands,  and  in  Mesostomum  about 
ten  entering  spermatozoa.  The  formation  of  the  first  amphiaster  has 
nothing  to  do  either  with  their  presence  or  their  absence. 

In  Aulostomum  and  Piscicola  the  author  made  the  important  obser- 
vation that  the  spermatozoa  pass  into  the  unripe  egg,  and  are  there 
broken  up.  This  explains  how  it  was  that  Robin  took  the  ovaries  of 
Nephelis  for  oospermatophores.  In  this  form  the  spermatozoa  are 
set  radially,  and  maintain  their  movements  for  some  time  after  their 
entrance  into  the  egg. 

Influence  of  Light  on  the  Development  of  Animals.  J — M.  Yung 
states,  that  from  observations  which  he  has  been  making  at  Naples,  he 
is  able  to  confirm,  with  regard  to  marine  forms,  the  results  arrived  at 
by  him  in  experiments  on  fresh-water  forms.  Eggs  of  Loligo  vulgaris, 
and  Sepia  officinalis,  placed  in  vessels  containing  two  litres  of  water, 
and  subjected  to  monochromatic  lights  of  different  shades,  developed 
at  unequal  rates,  those  which  were  under  violet  or  blue  had  their  de- 
velopment accelerated,  those  under  red  or  green  retarded.  Yellow 
most  resembles  white  light  in  its  eff'ects.  Such  larval  specimens  of  the 
Ascidian,  Ciona  intestinalis,  as  fixed  themselves  to  his  violet  glasses 
grew  more  rapidly  and  gave  rise  to  more  vigorous  individuals  than 
those  which  fixed  themselves  to  the  other  vases.  Contrary  to  his 
earlier  results,  he  finds  that  development,  though  retarded,  is  in  fact 
effected  under  the  influence  of  red  or  green  glasses. 

*  1^°  It  should  be  understood  that  the  Society  do  not  hold  themselves  respon- 
sible for  the  views  of  the  autliors  of  the  papers,  &c.,  referred  to,  nor  for  the  manner 
in  which  those  views  may  be  expressed,  the  object  of  the  Kecord  being  to  present 
a  summary  of  the  papers  as  actually  published.  Objections  and  corrections  should 
therefore,  for  the  most  part,  be  addressed  to  the  authors. 

t  '  Zool.  Anzeig.,'  iii.  (1880)  p.  426. 

X  'Comptes  Rendus,'  xci.  (1880)  p.  440.  See  also  '  MT.  Zool.  Stat.  Neapel,' 
ii.  (1880)  pp.  233-7. 


RECORD    OF    CURRENT   RESEARCHES,    ETC.  919 

Origin  of  the  Nervous  System. — The  following  is  from  Mr.  F.  M. 
Balfour's  address  to  the  Department  of  Anatomy  and  Physiology,  at 
the  recent  meeting  of  the  British  Association  : — 

"  The  general  features  of  the  origin  of  the  nervous  system,  which 
have  so  far  been  made  out  by  means  of  the  study  of  embryology,  are 
the  following : — 

1.  The  nervous  system  of  the  higher  Metazoa  has  been  developed 
in  the  course  of  a  long  series  of  generations  by  a  gradual  process  of 
differentiation  of  parts  of  the  epidermis. 

2.  Part  of  the  central  nervous  system  of  many  forms  arose  as  a 
local  collection  of  nerve-cells  in  the  epidermis,  in  the  neighbourhood 
of  rudimentary  organs  of  vision. 

3.  Ganglion-cells  have  been  evolved  from  simple  epithelial  cells 
of  the  epidermis. 

4.  The  primitive  nerves  were  outgrowths  of  the  original  ganglion- 
cells  ;  and  the  nerves  of  the  higher  forms  are  formed  as  outgrowths 
of  the  central  nervous  system. 

The  points  on  which  embryology  has  not  yet  thrown  a  satisfactory 
light  are  : — 

1.  The  steps  by  which  the  protoplasmic  processes,  from  the  primi- 
tive epidermic  cells,  became  united  together  so  as  to  form  a  network 
of  nerve-fibres,  placing  the  various  parts  of  the  body  in  nervous  com- 
munication. 

2.  The  process  by  which  nerves  became  connected  with  muscles, 
80  that  a  stimulus  received  by  a  nerve-cell  could  be  communicated  to 
and  cause  a  contraction  in  a  muscle. 

Eecent  investigations  on  the  anatomy  of  the  Coelenterata,  especially 
of  jelly-fish  and  sea-anemones,  have  thrown  some  light  on  these  points, 
although  there  is  left  much  that  is  still  obscure. 

In  this  country  Mr.  Romanes  has  conducted  some  interesting 
physiological  experiments  on  these  forms ;  and  Professor  Schiifer  has 
made  some  important  histological  investigations  upon  them.  In 
Germany  a  series  of  interesting  researches  have  also  been  made  on  them 
by  Professors  Kleinenberg,  Glaus,  and  Eimer,  and  more  especially  by 
the  brothers  Hertwig,  of  Jena.  Careful  histological  investigations, 
especially  those  of  the  last-named  authors,  have  made  us  acquainted 
with  the  forms  of  some  very  primitive  types  of  nervous  system.  In 
the  common  sea-anemones  there  are,  for  instance,  no  organs  of  special 
sense,  and  no  definite  central  nervous  system.  There  are,  however, 
scattered  throughout  tlie  skin,  and  also  throughout  the  lining  of  the 
digestive  tract,  a  number  of  specially  modified  epithelial  cells,  which 
are  no  doubt  delicate  organs  of  sense.  They  are  provided  at  their 
free  extremity  with  a  long  hair,  and  are  prolonged  on  their  inner  side 
into  a  fine  process,  which  penetrates  the  deeper  part  of  the  epithelial 
layer  of  the  skin  or  digestive  wall.  They  eventually  join  a  fine  net- 
work of  protoplasmic  fibres,  which  forms  a  special  layer  immediately 
within  the  epithelium.  The  fibres  of  this  network  are  no  doubt 
essentially  nervous.  In  addition  to  fibres  there  are,  moreover,  present 
in  the  network,  cells  of  the  same  character  as  the  multipolar 
ganglion-cells  in  the  nervous  system  of  Vertebrates,  and  some  of  these 


920  RECORD    OP    CURRENT    RESEARCHES   RELATING   TO 

cells  are  characterized  by  sending  a  process  into  the  superjacent 
epithelium.  Such  cells  are  obviously  epithelial  cells  in  the  act  of 
becoming  nerve-cells  ;  and  it  is  probable  that  the  nerve-cells  are,  iu 
fact,  sense-cells  which  have  travelled  inwards  and  lost  their  epithelial 
character.  There  is  every  reason  to  think  that  the  network  just 
described  is  not  only  continuous  with  the  sense-cells  in  the  epithelium, 
but  that  it  is  also  continuous  with  epithelial  cells  which  are  provided 
with  muscular  prolongations.  The  nervous  system  thus  consists  of  a 
network  of  protoplasmic  fibres,  continuous  on  the  one  hand  with 
sense-cells  in  the  epithelium,  and  on  the  other  with  muscular  cells. 
The  nervous  network  is  generally  distributed  both  beneath  the  epi- 
thelium of  the  skin  and  that  of  the  digestive  tract,  but  is  especially 
concentrated  in  the  disk-like  region  between  the  mouth  and  tentacles. 

The  above  observations  have  thrown  a  very  clear  light  on  the 
characters  of  the  nervous  system  at  an  early  stage  of  its  evolution,  but 
they  leave  unanswered  the  questions  how  the  nervous  network  first 
arose,  and  how  its  fibres  became  continuous  with  muscles. 

It  is  probable  that  the  nervous  network  took  its  origin  from  pro- 
cesses of  the  sense-cells.  The  processes  of  the  different  cells  probably 
first  met  and  then  fused  together,  and  becoming  more  arborescent, 
finally  gave  rise  to  a  complicated  network. 

The  connection  between  this  network  and  the  muscular  cells  also 
probably  took  place  by  a  process  of  contact  and  fusion. 

Epithelial  cells  with  muscular  processes  were  discovered  by 
Kleinenberg  before  epithelial  cells  with  nervous  processes  were 
known,  and  he  suggested  that  the  epithelial  part  of  such  cells  was  a 
sense-organ,  and  that  the  connecting  part  between  this  and  the  con- 
tractile processes  was  a  rudimentary  nerve.  This  ingenious  theory 
explained  completely  the  fact  of  nerves  being  continuous  with  muscles  ; 
but  on  the  further  discoveries  being  made  just  described,  it  became 
obvious  that  this  theory  would  have  to  be  abandoned,  and  that  some 
other  explanation  would  have  to  be  given  of  the  continuity  between 
nerves  and  muscles.  The  hypothetical  explanation  just  offered  is 
that  of  fusion. 

It  seems  very  probable  that  many  of  the  epithelial  cells  were 
originally  provided  with  processes,  the  protoplasm  of  which,  like  that 
of  the  Protozoa,  carried  on  the  functions  of  nerves  and  muscles  at  the 
same  time,  and  that  these  processes  united  amongst  themselves  into  a 
network.  By  a  process  of  differentiation  parts  of  this  network  may 
have  become  specially  contractile,  and  other  parts  may  have  lost  their 
contractility  and  become  solely  nervous.  In  this  way  the  connection 
between  nerves  and  muscles  might  be  explained,  and  this  hypothesis 
fits  in  very  well  with  the  condition  of  the  neuro-muscular  system  as 
we  find  it  iu  the  Coelenterata. 

The  nervous  system  of  the  higher  Metazoa  appears  then  to  have 
originated  from  a  differentiation  of  some  of  the  superficial  epithelial 
cells  of  the  body,  though  it  is  possible  that  some  parts  of  the  system 
may  have  been  formed  by  a  differentiation  of  the  alimentary  epithelium. 
The  cells  of  the  epithelium  were  most  likely  at  the  same  time  con- 
tractile  and   sensory,  and  the  differentiation  of  the  nervous  system 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  921 

may  very  probably  have  commenced,  in  the  first  instance,  from  a 
specialization  in  the  function  of  part  of  a  network  formed  of  neuro- 
muscular prolongations  of  epithelial  cells.  A  simultaneous  differentia- 
tion of  otlaer  parts  of  the  network  into  muscular  fibres  may  have  led 
to  the  continuity  at  present  obtaining  between  nerves  and  muscles. 

Local  differentiations  of  the  nervous  network,  which  was  no  doubt 
distributed  over  the  whole  body,  took  place  on  the  formation  of  organs 
of  special  sense,  and  such  difierentiations  gave  rise  to  the  formation  of 
a  central  nervous  system.  The  central  nervous  system  was  at  first 
continuoiis  with  the  epidermis,  but  became  separated  from  it,  and 
travelled  inwards.  Ganglion-cells  took  their  origin  from  sensory 
epithelial  cells  prjovided  with  prolongations  continuous  with  the 
nervous  network.  Such  ei)ithelial  cells  gradually  lost  their  epithelial 
character,  and  finally  became  completely  detached  from  the  ejjidermis. 

Kcrves,  such  as  we  find  them  in  the  higher  types,  originated  from 
special  differentiations  of  the  nervous  network,  radiating  from  the 
parts  of  the  central  nervous  system." 

With  regard  to  organs  of  special  sense,  Mr,  Balfour  (in  an  earlier 
part  of  his  address)  pointed  out  that  it  might  have  been  anticipated 
a  priori  that  organs  of  special  sense  would  only  appear  in  animals 
provided  with  a  well-developed  central  nervous  system.  This,  how- 
ever, is  not  the  case.  Special  cells  with  long  delicate  hairs,  which 
are  undoubtedly  highly  sensitive  structures,  are  present  in  animals 
in  which  as  yet  nothing  has  been  found  which  could  be  called  a 
central  nervous  system ;  and  there  is  every  reason  to  think  that  the 
organs  of  special  sense  originated  j^ci^'i  passu  with  the  central  nervous 
system.  It  is  probable  that  in  the  simplest  organisms  the  whole 
body  is  sensitive  to  light,  but  that  with  the  apijcarauce  of  pigment- 
cells  in  certain  parts  of  the  body,  the  sensitiveness  to  light  became 
localized  to  the  areas  where  the  pigment-cells  were  present.  Since, 
however,  it  was  necessary  that  stimuli  received  by  such  organs  should 
be  communicated  to  other  parts  of  the  body,  some  of  the  epidermic 
cells  in  the  neighbourhood  of  the  pigment-spots,  which  were  at  first 
only  sensitive,  in  the  same  manner  as  other  cells  of  the  epidermis, 
became  gradually  difiercntiated  into  special  nerve-cells. 

As  to  the  details  of  this  differentiation,  embryology  does  not  as 
yet  throw  any  great  light ;  but  from  the  study  of  comparative  anatomy 
there  are  grounds  for  thinking  that  it  was  somewhat  as  follows : — 
Cells  placed  on  the  surface  sent  protoplasmic  processes  of  a  nervous 
nature  inwards,  which  came  into  connection  with  nervous  processes 
from  siinilar  cells  placed  in  other  jjarts  of  tlic  body.  The  cells  with 
such  processes  then  became  removed  from  the  surface,  forming  a  deep 
layer  of  the  epidermis  below  the  sensitive  cells  of  the  organ  of  vision. 
Witli  these  cells  they  remained  connected  by  protoplasmic  filaments, 
and  thus  they  came  to  form  a  thickening  of  the  epidermis  underneath 
the  organ  of  vision,  the  cells  of  which  received  their  stimuli  from 
those  of  the  organ  of  vision,  and  transmitted  the  stinnili  so  received 
to  other  parts  of  tlio  body.  Such  a  thickening  would  obviously  bo 
tlic  rudiment  of  a  central  nervoiis  system,  and  it  is  easy  to  see  by 
what  steps  it  might  become  gradually  larger  and  more  important,  and 


922  RECORD    OF    CURRENT   RESEARCHES    RELATING    TO 

might  gradually  travel  inwards,  remaining  connected  with  the  sense- 
organ  at  the  surface  by  protoplasmic  filaments,  which  would  then 
constitute  nerves.  The  rudimentary  eye  would  at  first  merely  consist 
partly  of  cells  sensitive  to  light,  and  partly  of  optical  structures  con- 
stituting the  lens,  which  would  throw  an  image  of  external  objects 
upon  it,  and  so  convert  the  whole  structure  into  a  true  organ  of  vision. 
It  has  thus  come  about  that,  in  the  development  of  the  individual,  the 
retina  or  sensitive  part  of  the  eye  is  first  formed  in  connection  with 
the  central  nervous  system,  while  the  lenses  of  the  eye  are  indepen- 
dently evolved  from  the  epidermis  at  a  later  period. 

Terminations  of  Nerves  in  the  Epidermis.* — Professor  Eanvier, 
in  a  paper  on  this  subject,  mentions  an  improvement  which  he  has 
devised  in  the  method  of  using  chloride  of  gold  for  investigations  on 
the  ultimate  nerve-endings  in  tissues,  the  process  of  Loewit,  though  a 
great  improvement  on  that"  of  Cohnheim,  having  disadvantages. 

In  the  first  place  Professor  Eanvier  placed  the  tissues  with  the 
nerve  terminations  two  to  four  hours  in  a  mixture  of  chloride  of  gold 
and  formic  acid  which  had  been  boiled  and  then  cooled.  After 
removal  and  washing,  the  reduction  of  the  gold  is  effected  either  by 
the  action  of  daylight  in  slightly  acidified  water,  or  in  the  dark  in  a 
solution  of  formic  acid.  By  this  method  the  terminations  of  the 
nerves  in  muscles  appear  continuously  arborescent  instead  of  being 
frequently  interrupted  as  when  Loewit's  process  is  employed.  At  the 
same  time  they  contain  some  irregularities.  For  this  reason  Professor 
Eanvier  says  it  became  necessary  to  invent  a  fresh  process,  and  he 
attempted  to  replace  formic  acid  by  one  which  would  not  have  an 
equally  deleterious  effect  on  delicate  elements,  and  he  believes  he  has 
found  it  in  lemon-juice.  This,  although  altering  nervous  tissues  by 
its  protracted  action,  yet  preserves  their  form  sufficiently  long  for  it 
not  to  be  altered  in  the  time  requisite  to  procure  the  whole  effect  of 
the  chloride  of  gold.  Preparations  of  the  white  or  red  muscles  of  the 
rabbit  treated  successively  with  lemon-juice  and  chloride  of  gold, 
preserve  the  nerve  terminations  not  only  continuously  arborescent 
but  also  remarkably  regular. 

This  process  was  adopted  by  Professor  Eanvier  in  his  investiga- 
tion of  the  nerve  terminations  in  the  epidermis  in  general  (employing 
the  snout  of  the  pig,  the  nose  of  the  mole,  and  the  skin  of  the  human 
finger),  and  after  a  brief  statement  of  the  results,  he  says  "  the  theory, 
or  rather  the  hypothesis,  which  I  propose  is  founded  on  the  facts 
which  I  have  just  briefly  expounded.  The  nerves  which  enter  the 
epidermis,  whatever  may  be  the  form  or  extent  of  their  ramifications, 
are  subject  to  a  continuous  evolution.  They  grow  while  at  the  same 
time  their  terminations  undergo  a  gradual  degeneration  ;  this  de- 
generation leads  to  the  formation  of  granules  of  nervous  substance, 
which  become  perfectly  free  and  are  soon  transported  into  the  inert 
layers  of  the  epidermis." 

Minute  Structure  of  Smooth  Muscular  Fibres.t — The  latest  re- 
searches of  Professor  Engelmann  have  led  him  to  the  conclusion  that, 

*  '  Quart.  Journ.  Micr.  Sci.,'  xx.  (1880)  pp.  45G-8,  plate  xxxvi. 
+  '  Rev.  Inteniat.  Sci.,'  vi.  (1880)  p.  1«2. 


INVEBTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  923 

notwithstanding  the  generally  received  opinion,  the  smooth  muscular 
fibres  are  made  up  of  fibrillae.  The  parts  which  have  been  made  the 
subject  of  his  investigations  are  the  stomach,  intestinal  canal,  bladder, 
and  arteries  of  rabbits,  pigeons,  tritons,  and  frogs,  together  with  various 
organs  from  invertebrate  animals. 

The  size  of  the  fibrillse  appears  to  be  fairly  constant,  and  their 
width  to  be  very  much  that  of  the  fibrillae  of  striated  muscular  fibre. 
They  are  generally  cylindrical  in  form  and  non-ramified ;  in  some 
abnormal  cases  they  exhibit  varicosities.  They  are  always  optically 
homogeneous,  and  very  markedly  exhibit  double  refraction.  Each 
fibrilla  is  surrounded  by  a  layer  of  homogeneous  matter,  not  doubly 
refractive,  and,  during  life,  scarcely  measurable.  It  would  seem  to  be 
soft  and  more  or  less  coherent.  In  most  cases  the  fibrils  are  set  at  equal 
distances  from  one  another,  and  are  not  grouped  into  fasciculi ;  they 
have,  as  a  rule,  a  direction  parallel  to  that  of  the  long  axis  of  the  muscle 
cells.  There  are,  however,  certain  very  remarkable  exceptions  to  this 
rule  to  be  observed  in  many  Invertebrata.  In  some  the  fibrils  exhibit 
a  helicoid  arrangement  around  the  longitudinal  axis  of  the  cells. 
Observations  on  this  point  can  easily  be  made  on  the  anterior  adductor 
muscles  of  Anodon,  and  it  will  then  be  seen  that  the  angle  which 
these  fibrils  make  with  the  axis  depends  largely  on  the  state  of  con- 
traction of  the  muscle.  "When  in  a  state  of  contraction  they  exhibit  the 
double  striation  which  was  first  observed  by  Schwalbe.  The  author 
shows  that  this  is  partly  due  to  an  optical  illusion,  and  in  part  to  the 
state  of  compression  of  the  fibrils.  It  is  not,  consequently,  correct  to 
regard  these  muscles  as  affording  any  intermediation  between  smooth 
and  striated  muscular  elements. 

A  very  remarkable  fact  has  also  been  noted  by  Engehnann — the 
optic  axis  of  the  doubly  refractive  fibrils  does  not  coincide  with  their 
longitudinal  axis,  but  with  that  of  the  cell. 

In  conclusion,  attention  is  directed  to  the  generalization  that  there 
is  a  unity  in  the  structure  of  the  different  contractile  elements ;  these 
arc,  strictly,  always  fibrils.  It  is  demonstrable  already  in  the  case  of 
muscles,  whether  "  smooth  "  or  "  striated,"  as  well  as  in  that  of  vibra- 
tile  cilia  and  of  spermatozoa.  Further  observations  will  probably 
show  it  to  be  true  of  many  foi-ms  of  protoplasm. 

Changes  which  Starch  undergoes  in  the  Animal  Organism.* — 
Hcrr  H.  E.  Bimmermanu,  alter  referring  to  the  statement  of  Musculus 
and  Gruber,  that  starch,  by  the  action  of  diastase  or  acids,  yields 
soluble  starch,  maltose,  grape-sugar,  and  three  forms  of  dextrin,  named 
respectively  a,  ft,  and  y  achroodextriu,  which  are  variously  affected  by 
ferments,  states  that  wliile  maltose  and  grape-sugar  are  produced  by 
the  action  of  saliva  on  starch,  glycogen,  whether  obtained  on  a  diet  of 
grape-sugar  or  albuminoids,  when  treated  in  the  same  manner,  yields 
larger  quantities  of  maltose  and  gi-ape-sugar  and  a  reducible  dextrin. 

Sachsse's  method  of  estimating  sugar  by  mercuric  iodide  was  used, 
as  it  was  found  difficult  to  determine  the  end  of  the  reaction  with 
Fehling's  solution.     The  substances  were  injected  into   the  jugular 

♦  '  riliijrer'a  Arohiv,'  xx.  (1880)  pp.  '201-10.  Sco  'Journ.  Chcin.  Soc.,' 
Abstr.  xxxviii.  (18S0)  p.  G77. 


924  RECORD    OF    CURRENT   RESEARCHES    RELATING    TO 

vein  of  a  rabbit,  and  tlie  urine  subsequently  examined,  with  the  follow- 
ing results : — 

Maltose  is  partly  converted  in  the  blood  into  grape-sugar,  and 
partly  passes  out  unchanged.  Soluble  starch  yields  dextrin  and  grape- 
sugar.  Achroodextrin  (a)  suffers  only  partial  change,  grape-sugar  and 
maltose  being  found  in  the  urine,  together  with  dextrin.  Achroodex- 
trin (13)  yields  a  similar  result.     Achroodextrin  (y)  yielded  no  sugar. 

Generally,  the  results  tend  to  show  that  the  changes  which  starch 
undergoes  in  the  body  are  similar  to  those  which  occur  when  it  is 
submitted  to  the  action  of  diastase  outside  it. 

B.  INVERTEBRATA. 

Deep-water  Fauna  of  the  Swiss  Lakes.* — Dr.  Asper  gives  a  brief 
account  of  his  investigations  into  the  fauna  of  eleven  of  the  Swiss 
lakes. 

That  of  the  Lake  of  Zurich  would  appear  to  be  very  rich.  The 
MoUusca  are  represented  by  various  genera,  and  those  delicate  Cyclads 
— the  Pisidia — are  always  present.  The  larvee  of  Diptera  were  also 
numerous.  Living  in  small  tubes  formed  from  the  slime,  they  are 
either  colourless  or  of  an  intense  yellow  or  red  colour ;  and  they  chiefly 
belong  to  the  genera  Cliironomus  and  Tanypus.  Acarida  were  nowhere 
completely  absent.  Vermes  were  richly  represented,  and  chiefly  by 
species  of  Lumbriculus  and  Scemiris.  Of  the  latter  genus  great  quan- 
tities were  observed.  There  was  also  a  colourless  Hydra.  In  the  Lake 
of  Lucerne  seventy  specimens  of  what  apjiears  to  be  Asellus  Foreli 
■were  taken  at  one  dredging.  Here,  again,  Lumbriculids  and  Dipterous 
larvfe  were  very  abundant.  In  the  Lake  of  Sils  (Engadine) — to  omit 
many  points  of  interest  in  other  lakes — the  Hydroids  aj)pear  to  be 
especially  remarkable.  A  new  species  is  described  and  figured  by  the 
author  under  the  name  of  Hydra  rhcetica.  Of  a  bright  red  colour,  and 
often  as  much  as  1^  cm.  in  size,  it  gives  indications  of  forming  buds 
which  remain  permanently  attached  to  it,  and  so  give  rise  to  a  colony. 
The  male  and  female  individuals  can  be  easily  distinguished.  The 
fauna  of  this  lake  was  very  rich  in  individuals,  though  comparatively 
poor  in  species. 

Dredgings  in  the  Bay  of  Biscay-t— The  following  are  some  of 
the  more  important  results  to  which  M.  A.  Milne-Edwards  directs 
attention. 

The  Crustacea  were,  he  says,  extremely  interesting ;  not  one  of  the 
specimens  dredged  is  also  littoral  in  habitat,  and  it  seems  as  though 
there  were  two  faunas  placed  one  above  the  other,  and  not  mixing. 
He  forms  a  new  genus — ScyramatMa — to  contain  Aiuathia  Carpenteri 
and  Scyra  umbonata ;  a  crab  with  phosphorescent  eyes  was  found  at 
various  depths  between  700  m.  and  1300  m.  (Geryon  tridens);  this  has 
been  already  seen  in  the  Norwegian  seas.  Munida  tenuimana^  with 
large  and  phosphorescent  eyes  was  not  rare.    Gnathoplia^isia  zoea,  which 

*  '  Zuol.  Auzeig..'  iii.  (1880)  pp.  130,  200. 
t  'CVtmples  Eeudus,'  xci.  (1880)  p.  355. 


INVERTEBRATAj    ORYPTOGAMIA,   MICROSCOPY,    ETC,  925 

has  only  as  yet  been  collected  by  the  '  Challenger '  (off  the  Azores 
and  near  Brazil)  was  also  met  with. 

Most  of  the  Mollnsca  belong  to  the  deep-sea  fauna  of  the  Xorth 
Atlantic  and  of  the  Arctic  Seas  ;  among  the  Mediterranean  forms, 
there  were  some  which  as  yet  have  only  been  found  in  the  fossil 
state.  The  similarity  of  the  deep-sea  fauna  at  different  latitudes  is 
very  strikingly  shown  by  this  collection,  Pteroj^oda  were  taken 
from  all  depths  ;  indications  of  HeteroiJoda  were  not  absent.  A  short 
list  of  the  more  important  Mollusca  obtained  is  given  by  M.  Milne- 
Edwards  in  a  foot-note.* 

ChaBtopod  worms  were  abundant  at  all  the  stations  ;  a  species  of 
the  remarkable  Chcetoderma  was  also  taken  ;  two  or  three  new  genera 
of  Gei)hyrea  were  met  with,  and  several  of  the  forms  had  a  resemblance 
to  the  arctic  species. 

A  new  species  of  Edwardsia  (or  Hyanthus),  a  beautiful  red  Adamsia, 
a  large  Bunodes,  and  a  new  species  of  Flabellum  represent  the  most 
striking  Zoantharia ;  the  Alcyonaria  are  reported  to  be  very  remark- 
able, and  among  them  was  a  specimen  of  the  rare  Umhellularia. 

The  Echinodermata  appear  to  form  the  most  valuable  part  of  the 
collection  ;  there  is  a  new  species  of  Phormosoma,  which  is  to  be  dis- 
tinguished from  P.  placenta  by  the  ornamentation  of  the  plates,  and 
by  its  large  sjiines  on  the  oral  surface  ;  Pourtalesia  Jeffreysii,  two 
new  and  remarkable  iSpatangoids  make  up  the  chief  Ecliinid  gains. 
The  Asterida  were  all  interesting  and  rare ;  but  above  all  we  have  to 
note  the  capture  of  Brisinga  coronata,  which  was  taken  at  several 
stations.  Among  the  Ophiurids,  which  were  abundant,  there  was 
found  one  which,  not  described,  is  said  to  be  probably  the  represen- 
tative of  an  absolutely  new  type.  There  are  some  new  and  fine  species 
of  Holothurioida,  Among  the  Crinoids  we  find  only  two  examples  of 
an  Aidedon,  allied  to  A.  Sarsi  of  the  Northern  Seas. 

Hyalonema,  Holtenea,  Farrea,  &c.,  were  among  the  Siliceous 
Sponges, 

Large  specimens  of  Orhitolifes  ieniiisshna  and  a  magnificent  series 
of  arenaceous  forms  are  to  be  noted  among  the  Foraniiuifera. 

In  some  cases  the  dredge  descended  to  3000  metres,  and,  in  addi- 
tion to  the  zoological  collections,  there  have  been  made  observations 
of  very  consideiablo  importance  on  the  hydrographical  relations  of 
the  sea-bottom  of  this  region. 

Deep  Dredgings  in  the  Lake  of  Tiberias,t— The  luvcrtebrata 
obtained  by  M,  Lortet  in  these  dredgings  include  ten  species  of 
Mollnsca,  of  which  three  are  new  to  science.  These  are  named  by 
M.  Locard,  Unio  Lortdi,  U.  pictrl,  U.  Maris  Galilai.  The  otbcr 
species  arc  Unio  tcrminalis  and  tijridis,  Cyrcna  flnminalis,  Neritina 
jordani,  Melania  tuherculata,  MelanopHis  prwmorsa  and  costala.  Tho 
three  latter  shells  give  the  fauna  a  marine  appearance ;  and  it  is  to  bo 
considered  as  a  transition-fauna  between  salt  and  fresh  water,  tho 
lake  having  probably  been  originally  salt,  and  subsequently  altered 

*  See  also  tlio  lists  of  Dr.  J.  Gwyn  JefTrpys,  'Ann.  niul  M;ip.  Nat  Hi.-;t  '  vi 
(1880),  pp.  31.')  and  374. 

t  'Comptea  Rendns,*  xoi.  (1880)  p.  r)no. 
VOL.  III.  3    Q 


926  RECORD   OF    CURRENT    RESEARCHES    RELATING    TO 

by  the  passage  of  the  Jordan  waters  tlirougli  it.  Near  the  shore  were 
found  a  small  shrimp,  and  the  crab  Telphusa  fluviatilis.  A  very  fine 
volcanic  mud  from  the  greatest  depths  contained  diatomSj  foraminifera, 
&c.     No  alga  was  brought  up. 

The  TJnio  shells  at  the  depth  of  250  metres  were  curiously  softened, 
and  resembled  in  condition  the  fossils  of  some  of  the  Tertiary  strata 
of  the  middle  of  France ;  this  is  probably  chiefly  due  to  pressure. 

Fresh-water  Microscopic  Ors^anisms.* — Professor  Maggi  has  pub- 
lished a  catalogue  of  the  Eotifera  of  Valcovia,  containing  fourteen 
genera,  and  eighteen  species. 

He  also  gives  a  list  of  the  fresh-water  Ehizopoda  of  Lombardy, 
and  has  come  to  the  conclusion  that  AmpMzonella  fiava  is  not  iden- 
tical with  Pseudochlamys  patella,  but  that  it  is  a  developmental  stage 
of  some  unknown  form.  He  has  investigated  the  plastids  found  in 
ciliated  Infusoria,  and,  especially,  those  which  are  found  in  the  nuclei 
of  the  Oxytricha.  When  these  organisms  are  treated  with  a  two-per- 
cent, solution  of  bichromate  of  potash,  dark  granulations  are  to  be 
observed  in  the  parenchyma  of  the  body,  and  a  black  reticulum  is 
also  to  be  made  out  in  the  nuclei. 

Mollusca. 

Excretory  System  of  the  Cephalopoda.f —  One  important  point 
to  which  Dr.  Vigelius  has  especially  given  his  attention  in  this  paper 
is  the  homology  between  the  renal  organs  of  the  cephalopodous  and 
■  of  the  other  Mollusca,  but  unfortunately  with  no  certain  result.} 

Commencing  with  the  DibrancMata  Decapoda,  he  finds  in  all  a 
general  agreement  in  the  essential  points ;  there  is  but  one  renal  sac, 
which  lies  between  the  gills  and  communicates  with  the  pallial  cavity 
by  two  symmetrical  efferent  ducts  or  orifices.  Various  veins,  which 
carry  venous  blood  to  the  gills,  also  pass  into  the  renal  sac,  and  enter 
into  close  connection  with  its  walls  ;  they  are  the  bearers  of  the  so- 
called  venous  appendages.  In  the  upper  or  dorsal  portion  of  the  sac 
there  are  two  bile-dacts  which  finally  unite  and  pass  their  contents 
into  a  gastric  cpecum.  The  sac  itself  is  laterally  connected  by  two 
orifices  with  a  large,  and  otherwise  closed  cavity  (viscero-i^ericardial 
cavity)  which  contains  the  arterial  heart,  the  median  portion  of  the 
branchial  veins,  the  branchial  hearts  with  their  appendages,  certain 
organs  of  the  digestive  system,  and,  finally,  the  generative  gland. 

In  place  of  a  short  account  of  the  different  forms  examined,  a 
somewhat  more  detailed  history  of  one  form — the  common  Sepia 
officinalis —will  be  j)referable.  Some  way  behind  the  anus  there  is  to 
be  noti'jcd  on  either  side  a  cylindrical  tubule,  which  projects  freely 
into  the  branchial  cavity ;  there  the  efferent  ducts  of  the  renal  sac 
have  thick  muscular  walls,  and  their  fine  lumen  opens  by  a  small, 
rounded,  terminal  pore ;  they  are  separated  from  one  another  by  the 
rectum  and  by  the  duct   of  the  ink-bag.     These  ducts  divide  the 

*  '  Rev.  Sci.  Nat.,'  ii.  (18S0)  p.  242. 

+  '  Niedcrl.  Arch.  Zool.,'  v.  (1880)  pp.  115-84.     (2  plates.) 
•  J  He  always  speak.s  of  that  part  of  the  body  wliich  contains  the  branchial 
eavity  as  being  ventral  in  position. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  927 

ventral  portion  of  the  renal  sac  into  two  lateral  regions ;  the  right 
one  is  elongated  in  form,  and  save  for  its  urethral  opening  would 
ajjpear  to  be  closed.  It  extends  backwards  as  far  as  the  aboral 
surface  of  the  branchial  heart,  while  anteriorly  it  gradually  diminishes 
in  size,  as  it  passes  into  the  right  ureter.  The  right  ventral  portion 
is  almost  completely  filled  up  by  the  numerous  api^endages  attached 
to  the  veins  which  traverse  it ;  these  are,  when  fresh,  more  or  less 
transparent  and  liyaline,  and  of  a  spongy  texture,  they  vary  in  size, 
and  in  s^iirit  specimens  often  form  a  single  mass. 

The  author  then  enters  into  a  detailed  account  of  the  veins  of  this 
(riglit  ventral)  region.  In  it,  as  in  the  left  ventral  portion,  there  are 
(l)a  branch  of  the  vena  cava,  (•2)  the  lateral  pallial  vein,  and  (8)  the 
vena  abdominalis  ;  and  these  are  attached  to  the  dorsal  and  lateral  walls. 
But  in  the  left  half  there  is  not,  as  there  is  in  the  right,  any  vein  for 
the  ink-bag,  or  any  vena  genitalis  ;  but  instead  of  these  there  is  a  me- 
senteric vein.  The  left  half  is,  moreover,  not  so  completely  closed  as 
the  right  is,  for  there  is  a  pore  by  means  of  which  it  is  connected 
witli  the  dorsal  half  of  the  renal  sac.  There  are,  further,  communi- 
cations (two)  between  the  two  ventral  portions.  The  superior  or 
d(n"sal  portion  of  the  sac  is  a  spacious  cavity  which,  save  for  the 
already-mentioned  ventral  pores,  is  completely  closed ;  but  it  does  not 
lie  directly  qu  the  ventral  half,  for  it  is  separated  by  a  portion  of  the 
body-cavity,  of  a  considerable  size.  Various  digestive  organs  are  to 
be  found  within  it ;  there  is  the  spirally  coiled  cfecura,  and  the  two 
gall-ducts,  with  tlieir  peculiar  ajjpeudagcs,  to  which  the  name  of 
pancreas  has  been  a])plied.  The  intervening  body-cavity,  already 
mentioned,  is  connected  with  the  sac  by  two  orifices ;  near  tlie  base  of 
each  ureter  there  is,  on  the  inner  wall  of  the  sac,  an  orifice  which  leads 
into  a  canal ;  this  canal  widens  into  a  cavity,  in  which  there  is  con- 
tained the  asymmetrically  placed  arterial  heart ;  the  hinder  portion 
of  this  "pericardial  cavity"  is  occupied  inferiorly  by  the  ink-baf' 
and  the  generative  organs,  and  is  limited  superiorly  by  the  dorsal 
portion  of  the  renal  sac;  its  right  side  is  almost  completely  filled  up 
l)y  the  stomach.  This  then  may  be  known  as  the  viscero-iJcricardial 
cavity. 

Within  the  renal  sac  there  are  to  be  found  reddish  spheres  with  a 
sharp  contour,  and  not  rarely  surrounded  by  a  colourless  ring  ;  there 
are  also  rhombic  crystals,  sometimes  reddish  in  colour,  and  varyin" 
much  in  size ;  in  form  they  resemble  crystals  of  uric  acid,  and  they 
seem  undoubtedly  to  be  products  of  excretion.  Other  spheres  are 
also  to  be  seen  in  the  freshly  killed  animal,  which  are  of  a  pale  green 
colour,  and  generally  exhibit  a  concentric  structure;  it  is  possible 
that  these  are  developiiieutal  stages  of  the  true  excretion-spheres. 
The  wall  of  the  sac  is  made  up  (d'  fibrillar  connective  tissue,  with  a 
few  muscular  bands.  Tlio  inner  surface  is  invested  by  a  unilaminato 
mosaic  of  ejiithelial  cells,  fiattened  or  polygonal  in  form,  and  pi*ovidcd 
with  largo  nuclei.  In  the  ureter  there  is  a  (.•ylindricul  epitlieliuni, 
whicli  gives  rise  to  a  fine  cuticle;  on  the  opjiosite  side  of  tlie  basal 
membrane  tliero  arc  a  nunilna-  of  irregularly  arranged,  circular  and 
longitudinal  muscular  fibres.     Tlie  venous  appendages  ai)pear  to  liave 

3  Q  2 


928  RECORD   OF    CURRENT    RESEARCHES   RELATraO   TO 

a  solely  excretory  function ;  each  of  them  consists  of  a  branching 
system  of  veins,  giving  off  a  number  of  finer  vessels,  which  extend 
to  the  periphery,  but  these  do  not  appear  to  exhibit  any  regular 
arrangement. 

In  the  Octopoda  Dihranchiata  we  again  find  two  renal  sacs,  which 
communicate  with  the  exterior  by  two  ureters  ;  but  the  ureters  are 
papilliform.  Veins  traverse  the  sac,  as  in  the  Decapoda,  and  on  their 
course  they  also  develop  venous  appendages  (excretory  organs)  ;  each 
renal  sac  communicates  with  a  system  of  canals  which  in  the  female 
leads  to  the  generative  gland,  and  in  the  male  to  the  investing  sac. 
In  the  female  the  canal-system  is  symmetrically  developed,  but  in  the 
male,  owing  to  the  cxcentric  position  of  the  generative  organs,  it  is 
asymmetrical.  The  author's  most  important  example  in  this  group  is 
Octopus  macropus. 

For  the  Tetrahranchiata  the  author  had  unfortunately  to  content 
himself  with  a  single  example ;  he  was  chiefly  able  to  concern  himself 
with  the  venous  apjiendages,  and  he  finds  that  in  histological  struc- 
ture they  have  a  very  close  resemblance  to  the  same  organs  in  the 
Dihranchiata,  and  the  same  is  true  as  to  the  four  renal  sacs. 

If  then  the  venous  appendages  of  all  the  Cephalopoda  are  formed 
on  the  same  type  it  will  be  well  to  sum  up  their  real  characters ;  they 
are  closed  branching  systems,  arising  from  the  veins,  of  a  secretory 
function ;  this  is  shown  not  only  by  their  structure  and  by  their 
relations  to  the  veins  but  by  the  presence  in  their  lumina  of  definite 
bodies,  which  are  obviously  excretory  products  ;  these  last  are  always 
given  off  in  a  solid  condition ;  and  the  fluid  present  appears  to  be 
only  the  medium  by  which  they  are  conveyed  to  the  exterior.  The 
agreement  between  the  Tetrahranchiata  and  Dihranchiata  does  not 
end  here  ;  in  both,  the  pericardium  is  provided  with  slits,  and  though 
those  of  the  Decapoda  do  not  now  open  into  the  pallial  cavity,  it  is 
very  probable  that  they  did  so  primarily.  The  branchial  hearts  do 
indeed  present  rather  more  difiiculties,  for  in  Nautilus  the  branchial 
hearts  with  their  appendages  are  not  to  be  found  in  any  viscero- 
pericardiac  cavity,  but  this  may  be  explained  by  supposing  that  these 
organs  were  in  the  Dihranchiata  primitively  separated  off"  from  the 
branchial  arteries,  and  became  locally  developed  to  their  present  size. 
In  that  artery  it  is  possible  to  distinguish  a  longer  and  wider  portion, 
from  one  which  is  narrower  and  shorter;  in  the  Dihranchiata  these  are 
separated  by  the  branchial  heart,  while  in  Nautilus  the  follicular 
appendage  is  developed  at  their  point  of  junction,  and  it  was  at  this 
point  that  the  venous  heart  of  the  Dihranchiata  was  develojDed.  If 
this  supposition  be  accepted,  it  easily  follows  that  in  all  jn'obahility 
the  appendage  of  the  venous  heart  was  develojied  from  the  follicular 
appendage  ;  and  there  is  still  a  great  morphological  similarity  between 
the  two  organs. 

The  author  is  not  inclined  to  agree  with  Hancock  in  regarding 
the  renal  chamber  of  the  Nudibrauchs  as  being  homologous  with  the 
renal  chamber  proper  of  the  Cephalopod ;  and  he  believes  that  the 
English  zoologist  has  been  led  astray  by  not  taking  into  account  the 
organization  of  Nautilus  ;  nor  does  he  seem  to  agree  with  the  views 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  929 

put  out  by  Gegenbaur ;  and  in  short  he  comes  to  the  conclusion  that 
we  have  not  as  yet  a  sufficient  body  of  facts  to  justify  us  in  arriving 
at  any  definite  determination  of  what  organs  in  the  other  Mollusca 
are  homologous  to  the  renal  organs  of  the  Cephalopoda. 

Influence  of  Acids  and  Alkalies  on  Cephalopods.* — M.  Yung 
finds  himself  able  to  confirm,  in  these  animals,  most  of  the  results 
obtained  by  M.  Eichet  when  operating  on  Crustacea. f 

The  Cephalopoda  are  extremely  sensitive  to  the  action  of  mineral 
acids ;  with  a  slight  dose  the  respiratory  movements  are  accelerated ; 
four  specimens  of  Eledone  moschata,  resjiiring  tweuty-four  to  twenty- 
six  times  a  minute,  gave  after  five  minutes  in  2  litres  of  water  con- 
taining -5  cc.  of  sulphuric,  nitric,  liydrochloric,  and  oxalic  acids, 
respectively,  fifty-six,  forty-two,  thirty-six,  and  thirty  respirations  a 
minute.  A  double  dose  in  the  case  of  all  but  oxalic  acid  had  a  toxic 
efiect,  but  sulphuric  acid  was  the  slowest  in  its  results. 

The  alkalies  may  be  ranged  in  the  following  order  of  toxicity : — 
ammonia,  potash,  sodium,  calcium,  baryta.  The  first  is  extremely 
rapid  ;  with  a  dose  of  one  per  thousand,  it  kills  almost  at  once ;  the 
respiratory  movements  are,  at  first,  accelerated,  and  after  having 
reached  a  maximum  which  varies  with  the  agent  employed,  they 
gradually  diminish. 

"Liver"  of  the  Gastropoda. :{: — Dr.  Barfurth  is  of  opinion  that  this 
organ  is  a  hepato-paucreas  ;  his  most  important  observations  appear  to 
have  been  on  Arion  empiricorum,  and  in  it  he  recognizes  three  kinds 
of  cells  as  comjiosing  the  gland  in  question. 

When  fresh  portions  of  the  organ  are  suitably  treated  with  osmic 
acid,  some  of  the  cells  rapidly  become  deejily  tinged  of  a  black  colour  ; 
these  are  regarded  as  the  preparers  of  the  hepatic  ferment ;  their 
contents  are  ordinarily  large  spheres,  of  a  yellow  or  brown  colour,  iu 
the  fresh  state ;  the  cells  are  generally  elongate,  and  often  spherical. 
The  second  set  of  cells  arc  the  true  hepatic  cells,  with  the  nucleus 
placed  in  their  basal  portion ;  elongated  in  form,  they  are  consider- 
ably thickened  near  the  lumen  of  the  follicle  ;  their  contents  chiefly 
consist  of  small,  spherical,  or  irregularly  shaped  granules,  which  only 
blacken  after  some  hours'  exposure  to  the  influence  of  osmic  acid ; 
the  secretion  of  these  cells  is  soluble  in  alcohol  or  ether,  contrary 
to  what  hai)pons  with  the  ferment-cells.  The  third  form  of  cell  is 
filled  with  highly  refractive  colourless  granules  which  consist  in  most 
cases  of  carbonate  of  lime,  allied  with  some  organic  substance ;  but 
their  further  characters  have  still  to  be  investigated. 

Ditterenccs  seem  to  obtain  between  the  aquatic  and  terrestrial 
Gastropods  in  their  bcliaviour  to  chemieal  reagents;  the  livers  of  the 
former  harden  much  ni(h-e  slowly  in  absolute  alcoliol  and  osmic  acid, 
and  their  ferment-cells  do  not  blacken  so  quickly  ;  while  the  cal- 
careous cells  may  be  absent,  scarce,  or  replaced  by  small  crystals  of 
what  is  ai)parently  oxalate  of  calcium. 

*  'Coiniiles  ReiuluM,'  xci.  (1880)  j).  43'J. 
t  See  this  Jntiriiftl,  </»t/<',  p.  (J'2S. 
X  'Zool.  Anzei-.,'  iii.  (I8S0)  \>.  191). 


930      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

Striated  Muscles  in  the  Monomyarian  Acephalous  MoUusca.* — 
Although  the  existence  of  such  muscles  was  affirmed  by  Eeichert  as 
early  as  1842,  and  by  subsequent  authors,  in  certain  Cephalopoda, 
Acephala,  and  Gasteropoda,  on  the  ground  of  a  transverse  striation 
which  was  noticed,  yet  M.  Blanchard  has  determined  these  facts  to 
have  been  wrongly  interpreted :  such  striation  in  the  cases  advanced 
was  either  due  to  the  contracted  state  of  the  fibres,  or  to  a  special 
arrangement  of  the  intracellular  or  interfibrillar  granular  matter  of  the 
muscles. 

On  the  other  hand,  their  existence  in  certain  Mollusca  is  now 
established  by  his  own  investigations,  viz,  in  the  Pectinidce  alone. 

In  a  Pecten  (P.jacoheus,  e,  g.)  the  adductor  muscle  is  compound; 
a  smaller,  white,  shining  division  is  separated  from  the  rest  of  the 
mass  by  a  membrane  proceeding  from  the  sheath,  and  is  formed  of 
smooth  fibres ;  tbe  larger  mass,  which  consists  of  striated  fibres,  is 
dull  grey  in  colour. 

This  tissue,  like  the  muscle  of  the  wing  of  Htjdropliilus,  is  formed  of 
a  number  of  very  delicate  parallel  fibrillfe  not  united  by  sarcolemma,  but 
they  are  not  interspersed  with  granular  matter,  as  in  the  muscle  of  the 
insects'  wing.  Each  fibril  extends  from  one  valve  to  the  other.  Besides 
a  coarse  transverse  striation,  an  extremely  fine  one  is_  distinguishable 
by  a  power  of  500  to  600  diameters  ;  here  the  "  thick  disks  "  seen  in  the 
wing  muscle  of  HydropMlus  alternate  with  "  clear  spaces,"  which  here 
too  are  crossed  by  "  thin  disks  "  ;  by  treatment  with  chromic  acid  or 
with  dilute  alcohol  the  "  clear  spaces  "  are  also  seen  in  the  thick  disks, 
in  some  fibrils  here  also  the  thick  and  thin  disks  colour  strongly  with 
carmine,  and  especially  with  ha^matoxylin.  Polarized  light  exhibits 
the  "  disks  "  as  doubly,  and  the  clear  spaces  as  singly,  refractive, 
as  in  Vertebrata.  The  muscle  of  Pecten  is  however  distinguished 
more  evidently  from  that  of  E ijdropMlus  by  the  occurrence  on  each 
fibril  of  a  large  elongated  nucleus  which  projects  from  the  surface, 
colours  strongly  with  carmine,  and  contains  granular  protoplasm.  The 
mean  diameter  of  the  fibril  is  -01  mm.,  varying  to  '02  mm.;  the 
mean  length  of  the  nucleus  is  from  -01  to  -012  mm.,  its  breadth  from 
•004  to  -005. 

If  the  adductor  muscle  of  Pecten  is  homologous,  as  M.  Lacaze- 
Duthiers  has  declared,  with  the  posterior  adductor  of  the  Dimyaria, 
one  would  expect  to  find  striated  fibres  in  this  muscle  also ;  but  they 
are  absent  from  this  and  all  other  parts  of  Mytilus  edidis,  Anodonta, 
and  Unio  hitherto  investigated.  The  compound  nature  of  the  muscle 
in  the  former  case  points  rather  to  the  conclusion  arrived  at  by 
Gegenbaur,  that  it  consists  of  the  two  originally  distinct  adductors. 

As  an  object  for  histological  study  this  muscle  is  preferable  to  that 
of  the  HydropMlus  wing,  as  it  is  easy  to  fix  it  either  in  the  relaxed 
or  contracted  state  ;  the  fibres  are  larger  and  more  easily  isolated,  and 
the  granular  substance  which  interferes  with  the  preparation  in  the 
latter  case  is  here  absent.  Although  the  tissue  has  been  vainly  sought 
for  in  the  Gasteropods  and  in  various  races  of  the  oyster,  yet  in  the 
latter  form  the  adductor  presents  very  ditierent  characters  in  its  two 
halves,  so  that  it  gives  encouragement  to  further  investigation. 
*  ■  Kev.  lutciiiiit.  Soi.,'  v.  (1880)  p.  356. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  931 

Green  Colour  of  Oysters.* — lu  1877,+  mention  was  made  of  the 
fact  that  the  green  cohmv  observed  in  oysters,  in  certain  localities,  is 
caused  by  a  variety  of  Navicula,  to  whicli  the  name  N.  oslrearia  has 
been  given.  Further  particulars  of  experiments  made  by  M.  Puysegur, 
at  Sissablc,  are  not  without  interest.| 

"  The  green  slime  was  collected  by  lightly  scraping  the  margin  of 
one  of  the  '  clears '  with  a  sjioon,  and  was  put  in  flasks,  shaken  for  a 
moment,  and  then  allowed  to  settle,  so  as  to  get  rid  of  the  mud,  some 
admixture  of  which  is  inevitable.  The  coloured  fluid,  containing 
little  or  nothing  besides  diatoms,  was  then  poured  ofl'  into  other  flasks. 
Care  and  some  little  dexterity  are  requisite,  as  if  there  is  too  much 
silt,  or  too  large  a  quantity  of  water,  which  is  generally  the  case 
when  the  task  is  intrusted  to  a  subordinate,  it  is  sometimes  next  to 
impossible  to  concentrate  the  fluid  enough  to  show  the  results  with 
the  desired  plainness. 

Returning  home,  we  poured  the  fluid  into  soup-plates  set  on  a 
table  before  a  window.  The  diatoms  speedily  settled  on  the  sides 
and  bottoms  of  the  plates,  coating  them  with  a  green  slime,  the  thick- 
ness and  tint  of  which  varied  with  the  jiroportiou  of  diatoms  present. 
In  each  plate,  according  to  its  size,  we  put  three  to  six  i)erfcctly 
white  oysters,  which  had  never  been  in  the  '  clears,'  and  the  shells  of 
which  had  jjreviously  been  washed  and  brushed  clean.  In  similar 
l)lates  like  numbers  of  the  same  oysters  were  laid  in  ordinary  sea- 
water.  Twenty-six  hours  after  the  ccmimencement  of  the  experiment 
the  oysters  in  tlic  water  charged  with  diatoms  had  all  acquired  a 
marked  grecnisli  hue ;  the  other  oysters  remained  unaltered.  The 
experiment  was  repeated  many  times  with  identically  the  same  results. 
The  green  colour  in  the  oysters  was  found  to  be  more  decided  in 
l)roportion  as  tlie  water  was  more  highly  charged  with  diatoms. 
In  the  course  of  the  experiments  the  shell  of  one  of  the  oysters  was 
l)erforated,  so  as  to  lay  bare  tlie  mantle.  After  the  oyster  had  turned 
green,  it  was  laid  in  ordinary  sea-water  for  a  few  days,  when  the 
greenness  disapi)eared  altogether.  It  reai)peared  when  the  oyster  was 
replaced  in  fresh  water  containing  Navicula  ostrearia. 

In  the  course  of  tlie  exi)eriments  it  was  observed  that  by  the  open- 
ing and  closing  of  their  valves  the  oysters  induced  currents  in  the 
water,  by  means  of  which  they  drew  towards  them,  and  surrounded 
themselves  with,  the  particles  of  matter  suspended  therein.  The 
existence  and  direction  of  these  currents  were  shown  by  the  dis- 
ajjjtearance  of  the  slime  and  the  consequent  laying  bare  of  the  sides 
and  bottoms  of  the  i)lates,  the  diatoms  remaining  only  at  jjoints  out 
of  reacli  of  the  currents.  Directed  towards  the  biitcal  ajierture  by 
the  cilia  with  whicli  the  branehiie  are  provided,  the  Navicahv.  enter 
the  stomach  of  the  molluse,  and  there  part  with  their  nutritive  con- 
stituents. The  yellow  chlorophyll  is  digested  and  decomposed  ;  the 
soluble  colouring  mutter  passes  direct  into  the  blood,  to  which  it 
iiiij)iu-ts  its  colour.  Thus  it  happens  that  the  most  vesicular  portions 
of  the  structure,  us  the  bruuchiic,  arc  the  most  highly  coloured. 

Examination  of  the  digestive  tubes  of  the  oystcx's  cxporimeuted 

•  '  Nature,'  xxii.  (ISSd)  )).  ."ilil.  t  H'l''-.  xvi.  (1877)  p.  :{;>7. 

\  '  liivuf  iiiuiilime  tt  (.uldiiiiilc,'  l-Mirunry  ISSO. 


932  RECOBD    OF   CURRENT    RESEARCHES    RELATING    TO 

upon  proved  the  fact  of  tlie  absorption  of  the  diatoms.  The  stomachs, 
intestines,  and  ffeces  were  strewed  with  loric^e  of  Naviculce.  The 
loricte,  being  siliceous,  are  not  aifected  by  the  digestive  juices,  and 
it  would  seem  extraordinary  that  with  so  tenacious  a  covering  their 
contents  should  be  evolved,  were  it  not  for  the  knowledge  of  the  fact 
that  the  covering  is  not  continuous,  the  line  of  suture  separating  the 
valves  composing  the  frustule  being  scarcely  silicified  at  all." 

It  would  therefore  appear  to  be  established  beyond  dispute  that 
the  green  hue  in  oysters  is  due  exclusively  to  their  absorption  of 
certain  Naviculce  contained  in  the  circumambient  water.  The  facts 
are  in  perfect  keeping  with  the  observations  of  growers,  that  heavy 
rains  (which  increase  the  supply  of  fresh  water)  cause  the  disappear- 
ance of  the  green  from  the  "  clears,"  while,  on  the  other  hand,  dry 
north-east  gales,  which  greatly  increase  the  saturation  of  the  water, 
bring  it,  as  it  is  called,  "  into  condition." 

Two  points  of  special  interest  in  connection  with  the  subject 
remain  for  future  investigation.     These  are  : — 

1.  Does  the  NavicuJa  in  question  remain  all  the  year  in  the  waters 
where  it  is  found  in  winter  ? 

2.  Is  the  coloration  of  the  beds  accidental  or  temporary  ?  In 
other  words.  Does  this  alga  disappear  from  the  reservoirs  when  the 
water  changes  its  colour,  or  does  it  become  itself  discoloured  for 
a  time  ? 

Neomenia  gorgonophilus.* — Dr.  A,  Kowalevsky  has  described  the 

structure  of  this  new  si:)ecies. 

About  2  inches  long,  it  lives  parasitically  on  Gorgonias,  creeping 
about  after  the  manner  of  a  Nemertine.  On  the  lower  surface  of  the 
body  there  extends,  from  the  mouth  to  the  anus,  an  exceedingly  delicate 
ciliated  foot.  The  gelatinous  investment  of  the  rest  of  the  body  con- 
sists of  (1)  a  gelatinous  substance ;  (2)  calcareous  spicules  in  a  horny 
basal  layer,  and  (3)  epithelial  cells  of  two  forms ;  in  one  the  cells  are 
short,  and  in  the  other  elongated.  Subjacent  to  the  integument  there 
is  a  muscular  layer,  which  is  especially  well  developed  in  the  region 
of  the  foot,  and  in  this  region  there  are  not  only  longitudinal,  but  also 
transversely  disposed  muscles.  The  enteric  tract  is  straight,  and 
appears  to  ojjen  posteriorly  into  a  muscular  cloaca  ;  into  this  there 
also  open  the  duct  of  the  ovary,  and  two  tubular  glands,  which  are  very 
jjrobably  the  testicles.  There  is  a  supra-oesoiDhageal  ganglion,  whence 
arise  four  longitudinal  nerve-trunks,  which  extend  through  the  whole 
length  of  the  body  ;  two  are  larger  and  median  (pedal)  and  two  smaller 
and  lateral.  They  are  regarded  as  corresponding  to  the  pedal  and 
branchial  trunks  of  the  Chitons.  The  dorsal  vessel,  which  is  best 
seen  in  young  examples,  has  a  considerable  enlargement  anteriorly. 
As  to  the  organs  of  secretion,  the  author  finds,  at  the  sides  of  the 
digestive  canal,  a  large  number  of  cells,  which  fill  up  the  whole  space 
between  it  and  the  walls  of  the  body,  and  contain  rounded  concretions, 
similar  to  those  found  in  the  molluscan  organ  of  Bojanus.  Above 
the  dorsal  vessel,  and  on  either  side  of  it,  there  lies  the  paired  ovary. 

*  '  Zool.  Anzeig.,'  ill.  (1880)  p.  190. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC  933 

The  organ  which  has  been  regarded  as   the  testicle  lies   below  the 
enteric  tract ;  it  commences  as  an  unpaired  tube,  but  soon  bifurcates. 

Molluscoida. 

Australian  Polyzoa.* — The  Rev.  J.  E.  Tenison-Woods  gives  a 
description  and  figure  of  an  Amathia  from  Australia,  which  he  considers 
new,  and  calls  A.  torfuosa,  and  takes  the  opportunity  of  reviewing  the 
family.  This  species  is,  however,  common  in  the  Mediterranean,  and 
is  no  doubt  the  Serialaria  semiconvoluta  of  authors  on  the  Mediter- 
ranean fauna,  which  has,  however,  as  yet  been  but  imperfectly  and  not 
always  correctly  described.  The  fact  of  the  cells  being  biserial  has 
led  one  Australian  author  to  form  a  new  genus  for  the  species,  but 
the  growth  is  the  same  with  the  Mediterranean  and  several  other 
species,  which,  however,  varies  much  in  the  length  of  the  inter- 
nodes,  so  that  one  Euroi^ean  writer  has,  in  manuscript,  called  a  variety 
similar  to  the  Australian  one,  Serialaria  distans. 

Mr.  Woods  has  not  given  the  size  of  his  forms,  which  is  impor- 
tant, as  we  believe  the  variety  in  the  Australian  seas  has  a  much  larger 
growth  than  the  Mediterranean  one.  Although  this  paper  is  founded 
on  a  mistake,  Mr  Woods  has  put  together  a  great  deal  of  information 
on  the  family  which  will  be  of  use  to  workers  in  Australia,  where  the 
literature  is  not  so  easily  obtainable. 

Mr.  Woods  very  wisely  gives  a  figure  of  what  he  considered  a  new 
species,  and  it  would  be  a  great  benefit  if  other  authors  would  follow 
him  in  this,  for  several  Australian  and  New  Zealand  workers  have 
lately  been  giving  descriptions  without  plates,  and  thus  names  have 
been  created,  to  a  large  extent,  of  forms  wliich  the  descriptions  (in  not 
a  few  cases  imperfect)  will  not  enable  others  to  recognize. 

Fossil  Cateidcellae  from  the  (Australian)  Mioeene.t — Mr.  J.  B. 
Wilson  reports  tae  discovery  of  Catenicelhe  in  the  Miocene  Tertiary 
beds  near  Geelong,  on  whicli  Mr.  Busk  has  favoured  us  with  the  fol- 
lowing note  : — 

"  The  occurrence  of  Catenicellidsc  in  the  fossil  state,  and  so  far  back 
as  the  Miocene  epoch,  if  that  be  really  the  age  of  the  beds,  is  an  impor- 
tant and  interesting  fact.  In  18G5  the  Rev.  J.  E.  Tenison-Woods,  in  a 
paper  on  the  fossil  Polyzoa  of  the  same  district,  laid  i)articular  stress 
on  the  circumstance  that  the  marine  fauna  of  that  period  ditlbred 
essentially  from  the  existing  fauna  in  tlie  total  absence  of  Catenicel- 
lida;,  which  form,  as  it  may  be  said,  one  of  the  most  characteristic 
features  of  tlie  existing  Australian  marine  fauna  (so  far  as  the  Polyzoa 
are  concerned).  It  now  a^ipears  that  in  rtality  the  Miocene  fauna 
was  as  rich  in  those  forms  as  it  is  now.  Mr.  Wilson  enumerates 
about  twenty  extinct  species,  all,  ho  says,  ditlennt  from  the  existing 
ones,  which,  so  far  as  I  am  aware,  do  not  amount  to  more  than  thirty. 

When  we  consider  that  beyond  the  Australian  region,  including, 
of  course,  New  Zeahind,  scarcely  more  than  a  single  species  of 
Calenicclla  is  anywliero  met  with  at  the  present  time,  and   that  none 

*  Tonison- Woods,   Rev.  .1.   K.,  "  On    tho   Ginus  Atnithia  of  Lam.,  witli   a, 
Description  of  new  Species,"  'Trans,  and  Proo.  R.  Sec.  Vict.,'  ivi.  (1880). 
t  •  Joiirii.  Micr.  8oc.  Vict.,'  i.  (1880)  pp.  (30-3. 


934      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

have  ever  been  met  witli  fossil  except  iu  Australia,  it  would  seem,  so 
far  as  tliis  evidence  goes,  that  the  Australian  Polyzoan  fauna  was  as 
peculiar  to  that  region  iu  the  Miocene  period  as  it  is  at  the  present  day. 
The  si)ccies  all  seem  to  have  changed,  it  is  true,  but  they  do  not  appear 
to  have  either  advanced  or  retrograded,  since,  according  to  Mr.  Wilson, 
the  Miocene  fossil  forms  may  be  classified  in  the  same  groups  as  those 
of  the  present  time. 

This  communication  appears  to  me  of  the  highest  interest  palsBon- 
tologically,  and  it  is  much  to  be  wished  that  we  should  have  carefully 
drawn  figures  as  well  as  descriptions  of  the  forms  mentioned,  as  in 
things  so  similar,  verbal  descriptions  are  insufi&cient  fur  any  critical 
pur2)0se." 

Recent  and  Fossil  Species  of  Australian  Selenariadse.* — The 
Eev.  J.  E.  Tenison- Woods  gives  a  short  review  of  the  Selenariadse, 
a  family  of  Polyzoa,  and  then  proceeds  to  describe  several  new 
sjjecies  of  Lunulites  and  Selenaria,  both  recent  and  fossil.  He  con- 
siders the  genus  Cupularia  of  Busk  a  superfluity  and  unites  it  with 
the  genus  Lunulites,  believing  that  Cwpularia  cannot  even  be  main- 
tained as  a  subgenus,  as  the  same  individual  may  sometimes  have  the 
features  of  Ciqndaria  in  one  part  and  those  of  Lunulites  in  another. 

This  family  is  only  represented  by  a  few  living  species  iu  the 
northern  hemisphere,  where,  however,  it  was  abundant  in  the  Cainozoic 
and  Neozoic  periods,  and  the  adlitiou  of  twelve  new  species,  of  which 
four  are  recent,  is  an  imj^ortant  addition  to  our  knowledge  of  the 
family.  All  the  sjpecies  are  well  figured  in  two  good  lithographed 
plates, 

Arthropoda. 
a.  lusecta. 

Undefined  Faculty  in  Insects.f — M.  J.  H.  Fabre  recalls  the  fact 
that  Ammopldla  (Sand-wasp),  boring  its  mine  until  a  late  hour  of  the 
day,  abandons  its  work,  after  having  closed  the  opening  with  a  stone, 
goes  to  a  distance,  and  yet  knows  how  to  return  next  day  to  its  home, 
though  the  localities  may  be  new  and  unknown.  Bemhex  also  has  a 
similar  power.  Where  human  observation  and  memory  are  defective, 
their  coup  d'oeil  and  remembrance  have  a  certainty  which  is  all  but  infal- 
lible. It  may  be  said  that  there  is  in  an  insect  something  more  subtle 
than  the  simple  faculty  of  remembering — a  kind  of  intuition  of 
localities  without  analogy  in  man — and  in  order,  if  possible,  to  throw 
some  light  on  this  point  M.  Fabre  instituted  a  series  of  experiments. 

The  first  experiment  was  with  twelve  females  of  Cerceris  tubercu- 
lata,  which  were  caught,  marked,  enclosed  sej^arately  in  a  box,  and 
released  in  the  fields  two  kilometres  from  the  nests.  They  all  went 
iu  a  direct  line  towards  their  nests,  and  five  hours  later  two  were 
found  there,  and  a  third  and  a  fourth  soon  followed. 

*  Teiiison-Woods,  J.  E.,  "  On  some  Eeccnt  aud  Fossil  Si^ecies  of  Australiim 
Selcnaiiaila3  (Polyzoa),"  '  Traus.  Pliil.  Soc.  of  Adelaide,'  ISSU. 

t  Fabre,  J.  H.,  '  Souveuirs  entomologiques.  Etudes  sur  riustinct  et  les 
uioeuis  des  Iiiscctes.'  :-;2i  jip.  (8vo,  Paris,  1879.)  See  'Eutouiol.  Mou.  Mag.,' 
xyii.  (1880)  pp.  100-2. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  935 

Another  experiment  was  made  with  nine  females,  which  were 
taken  three  kilometres  from  the  nests,  and  after  being  kcjit  in  confine- 
ment all  night  were  released,  not  in  the  fields,  which  may  jiossibly 
have  been  more  or  less  known  to  them,  but  in  the  public  street  of  a 
town,  in  the  centre  of  a  ])opulous  quarter,  to  which  the  Cercerides, 
with  their  rustic  habits,  had  certainly  never  penetrated.  Each  released 
Cerccris  rose  up  vertically  between  the  two  rows  of  houses,  as  if  to 
disengage  itself  as  quickly  as  possible  from  the  street ;  then,  clearing 
the  roofs,  it  launched  out  immediately,  with  a  hasty  flight,  towards 
the  south,  where  the  nests  were.  The  next  day  five  of  the  insects 
were  found  at  the  nests  (none  being  visible  the  previous  day). 

Transported  to  enormous  distances,  the  pigeon  promi)tly  returns. 
If  we  compare  the  length  of  the  jiassage  and  the  bulk  of  the  creature, 
the  Cerceris,  transported  to  a  distance  of  three  kilometres  and  return- 
ing to  its  nest,  is  much  superior  to  the  j^igeon.  The  bulk  of  the 
insect  is  not  a  cubic  centimetre,  and  that  of  the  pigion  amounts  to 
quite  a  cubic  decimetre.  The  bird,  a  thousand  times  larger  than  the 
liymenopteron,  should,  in  order  to  rival  it,  regain  its  home  from  a 
distance  of  3000  kilometres,  three  times  the  length  of  Franco  from 
north  to  south.  But  power  of  wing,  and  still  less  clearness  of  instinct, 
are  not  qualities  to  be  measured  by  the  metre.  The  relations  of  bulk 
cannot  here  be  taken  into  consideration,  and  we  can  only  see  in  tlie 
insect  a  worthy  rival  of  the  bird  without  deciding  which  has  the 
advantage. 

When  the  jugeon  and  the  Cerceris  are  artificially  removed  from 
home  by  man  and  transported  to  gi-eat  distances  into  regions  hitherto 
uuvisited  by  them,  are  they  guided  by  remembrance  ?  Can  memory 
serve  them  for  a  compass  when,  arrived  at  a  certain  elevation,  they 
recover  the  lost  j)oint,  and  start,  with  all  their  power  of  flight,  to  that 
side  t)f  the  horizon  where  their  nests  are  to  be  found  ?  Is  it  memory 
wliich  traces  their  route  in  the  air,  to  traverse  regions  they  see  for  the 
first  time  ?  Evidently  not ;  there  can  be  no  remembrance  of  the 
unknown.  The  hymenoptcron  and  the  bird  do  not  know  the  place  in 
wliich  they  find  themselves ;  nothing  can  have  informed  them  of  the 
general  direction  in  which  their  displacement  may  have  been  eftectcd, 
for  it  was  in  the  darkness  of  a  close  basket,  or  of  a  box,  that  the 
journey  was  made.  Locality,  orientation,  arc  unknown  to  them ; 
nevertheless  they  return. 

They  have,  then,  for  a  guide,  something  more  than  simitle  remem- 
brance ;  they  have  a  special  faculty,  a  kind  of  topogra[)hical  sense, 
of  which  it  is  impossible  for  us  to  have  any  idea,  not  having  anything 
analogous  to  it. 

Nervous  System  of  Oryctes  nasicornis.* — Dr.  Michelis  devotes 
70  pages  and  4  plates  to  an  account  of  the  nervous  system  of  this 
Lamellicoru  Coleojjteron,  in  its  larval,  pupal,  and  adult  stages ; 
like  numerous  of  its  allies,  it  is  interesting  from  the  fact  that 
there  is  a  great  want  of  similarity  between  what  is  seen  in  the 
larval    and    in   the  adult  form;    in  the  former  it  is  short  and  com- 

*  'Z.ilM-lir.  wirs.  Z.M.I.,'  xxxiv.  (ISSO)  p.  Gll-702. 


936  RECORD    OP    CURRENT   RESEARCHES    RELATING    TO 

pressed,  so  that,  on  superficial  examination,  there  appears  to  be 
only  one  fused  ganglionic  mass,  while,  in  the  latter,  the  thoracic 
ganglia,  at  any  rate,  are  separated  from  one  another  by  extended 
longitudinal  commissures.  Is  this  difference  due  to  a  new  formation, 
or  to  the  elongation,  as  it  were,  of  the  separate  parts  of  the  cord  ? 
The  result  will  show  that  his  observations  lead  the  author  to  be 
strongly  inclined  to  adopt  the  latter  view. 

The  cerebral  ganglion  of  the  larva  is  placed  at  about  the  middle  of 
the  head,  and  directly  on  the  cesophagus;  it  consists  of  two  lobes, 
pyriform  in  shape,  and  with  their  thickest  ends  approximated  and 
directed  anteriorly.  There  is  some  difference  in  the  form  of  the 
masses  in  the  younger  and  older  larvte.  From  the  anterior  surface 
there  are  given  off  four  nerves  for  the  mouth  ;  at  about  the  same 
place  there  arises  the  nervus  recurrens,  and  behind  these  there  is 
an  unpaired  nerve  which  goes  to  the  oesophagus  ;  shortly  before  this 
reaches  the  midgut  it  enlarges  into  a  ganglion;  very  similar  rela- 
tions are,  so  far  as  this  is  concerned,  seen  in  the  adult,  save  only  that 
the  ganglia  frontalia  have  considerably  increased  in  size.  The 
ganglia  of  the  paired  bucco-gastric  nerves  are  similarly  larger,  and 
the  double  character  which  they  had  in  the  larva  is  exchanged  for 
an  apparent  unity.  On  the  other  hand,  the  transverse  commissure 
which  connects  these  ganglia  is  much  shorter  than  in  the  larva ;  the 
various  intermediate  stages  between  the  two  are  to  be  made  out  in 
successive  stages  of  the  pupa.  The  same  is  exactly  true  of  the  com- 
missures of  the  oesophageal  ring.  With  regard  to  the  ventral  chain, 
the  author  is  in  agreement  with  Cuvier ;  in  the  larva  it  ends,  so  far 
as  he  has  seen,  at  the  point  of  separation  of  the  second  and  third 
segments  of  the  body.  In  a  larva  2  cm.  long  it  measured  •  2  cm.  and 
•07  cm.  broad;  in  one  3*4  cm.  long,  it  was  -31  cm.  long  and  '075 
broad  ;  in  the  adult  stage  it  measured  •  79  cm.,  while  the  length 
of  the  ganglia  amounted  to  -52  cm.,  a  length  which  had  been 
observed  in  some  of  the  oldest  of  the  larvae  ;  the  agreement  between 
the  two  is  sufficiently  striking,  and  it  only  remains  to  note  that  the 
breadth  was  in  the  adult  somewhat  greater,  being  in  the  proportion 
of  eleven  to  nine  in  the  larva. 

The  author  enters  into  a  detailed  description  of  the  nervous 
system,  an  account  of  which  would  be  altogether  unintelligible  unless 
it  were  accompanied  by  the  figures  with  which  he  illustrates  it. 

Tlie  second  portion  of  the  paper  deals  with  the  relations  of  the 
tracheal  to  the  nervous  system ;  and  the  third  with  an  account  of 
the  more  minute  structure  of  the  ventral  cord.  In  the  larva  there  are 
two  investing  layers,  which  are  distinguished  as  the  outer  and  the 
granulo-cellular  neurilemma ;  the  former  is  an  obscurely  striated 
membrane,  with  elongated  nuclei  embedded  in  it.  The  latter  forms  a 
stratum  of  finely  granular  substance,  with  clear  rounded  nuclei; 
there  are  no  definite  boundaries  to  its  cells ;  it  is  feebly  developed  on 
the  dorsal,  and  well  developed  on  the  ventral  surface  of  the  cord ; 
it  is  the  part  which,  in  connection  with  the  tracheae,  produces  the 
segmentation  of  the  ventral  cord.  The  ganglion  cells  surround  the 
central  fibrous  layer  in  an  almost  continuous  investment,  save  at  the 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  937 

median  plane,  where  the  cells  of  the  neurilemma  are  best  developed  ; 
they  vary  greatly  in  size. 

Referring  to  the  paper  for  the  other  important  details  with  which 
it  abounds,  we  find,  as  a  general  conclusion,  that  the  separate  ganglia 
of  the  adult  do  not  arise  from  any  new  formations,  but  from  the 
extension  of  the  ventral  cord  of  the  larva  ;  the  peripheral  nerves  are 
the  same  in  both  ;  there  is  no  histolysis  of  the  larval  nerves,  but  a 
growth  of  the  nerve-trunks.  In  both,  there  are  the  same  number 
of  ventral  ganglia,  both  have  similar  relations  to  the  tracheal  system, 
and  intermediate  conditions  are  to  be  seen  in  the  pupa.  There  is  no 
"  dotted  substance "  as  Leydig  understands  the  term,  and  no  true 
transverse  commissures ;  instead  of  these  there  are  a  large  number  of 
transverse  bundles,  which,  on  the  one  side,  arise  from  the  ganglia, 
and  on  the  other,  form  the  peripheral  nerves. 

Activity  of  Bees.* — The  paper  of  E.  Erlenmeyer  and  A.  v,  Planta- 
Reichenau  is  a  sequel  to  former  reports  f  on  a  similar  subject,  being 
further  experiments  made  to  ascertain  whether  the  wax  secreted  by 
bees  is  derived  from  the  sugar  and  other  carbo-hydrates  which  are 
found  in  the  nectar  of  the  flowers,  or  from  such  nitrogenous  matters 
as  exist  in  the  pollen. 

A  healthy  swarm  was  bought  in  February,  well  cared  for  and 
fed,  and  at  the  beginning  of  the  experiments  was  in  a  very  healthy 
condition.  A  determined  number  of  the  bees  was  carefully  weighed, 
and,  with  the  queen,  transferred  to  the  experimental  hive,  which  was 
furnished  with  all  appliances  requisite  for  carrying  out  the  experi- 
ments. The  food  was  weighed  in  tared  capsules.  Before  tlie 
weighing  of  the  swarm,  fifty  of  the  bees  were  killed  with  chloro- 
form vapour,  and  used  for  fat  and  nitrogen  determinations.  Each 
experiment  lasted  four  days  and  four  nights,  and  for  a  whole  day 
the  animals  were  confined  to  tlie  hive. 

The  bees  were  first  fed  with  a  solution  of  sugar-candy,  and  a 
remarkable  yield  of  wax  was  the  result.  The  suggestion  was  made 
that  the  albumen  in  their  bodies  contributed  to  it,  but  both  the 
nitrogen  and  the  fat  were  the  same  before  and  after  the  experiment. 
A  second  trial  w.is  made  by  feeding  the  bees  on  honey,  but  the 
quantity  of  wax  produced  was  less.  Further  observations,  extended 
over  longer  periods,  were  made,  with  a  view  to  see  what  etfect  tempe- 
rature would  have  on  the  production  of  wax.  The  first,  made  during 
favourable  weather,  on  sugar-candy  solution  mixed  witli  1  per  cent,  of 
wheat-flour,  gave  very  good  results ;  the  second,  carried  on  simul- 
taneously, on  honey  and  wheat-flour,  gave  good,  but  still  inferior 
results ;  the  third,  with  the  same  food  as  the  first,  but  in  less  favour- 
able weather,  gave  a  much  inferior  yield  ;  in  another  experiment  the 
small  proi)()rtion  of  0  •  22  per  cent,  dry  gelatine  was  ailded  to  tlie  sugar 
solution,  witli  un.satisfactury  results,  whilst  a  much  larger  proportion 
of  gelatine,  1^  per  cent.,  added  to  honey  produced  a  very  largo 
amount.     When,  however,  the  quantity  of  gelatine  was  increased  to 

*  'Bicd.  Ci'ntr.,'  1880,  pp.   191-3.     See  Mourn.  Ch.m.  Soc.,'  Ahetr.  xxxviii. 
(1880)  j.p.  72.'') C. 
t  IM.l..  p.  115. 


938  KECOKD    OF    CUERENT   EESEARCHES   RELATING    TO 

5  per  cent.,  and  wlien  a  mixture  of  20  parts  peptone  and  20  parts 
honey  was  employed,  the  bees  refused  their  food  altogether,  and  most 
of  them  died.  A  mixture  was  made  of  1-18  parts  glutinous  peptone, 
100  parts  sugar,  and  60  parts  rose-water  ;  it  was  all  eaten,  but  neither 
honey  or  wax  produced  ;  the  bodies  of  the  bees  were  distended,  their 
honey-bags  full,  but  their  stomachs  empty.  A  mixture  of  342  grams 
sugar-syrup  and  28  grams  egg-albumen  was  also  quickly  consumed, 
but  no  honey  or  wax  obtained.  A  similar  mixture  of  egg-yolk  (24  to 
414  sugar-syrup),  produced  a  small  proportion  of  wax  only. 

As  general  results,  the  authors  believe  that  the  food  of  bees  should 
not  be  highly  nitrogenous,  and  that  beeswax  is  formed  from  non- 
nitrogenous  substances,  especially  sugar.  Erlenmeyer  is  further  of 
opinion  that  the  fatty  portions  of  the  bees'  bodies  are  formed  solely 
from  hydrocarbons,  the  albumenoids  only  playing  the  part  of  nourish- 
ment to  the  active  organs,  keeping  them  in  working  order  and 
supplying  waste. 

Scent-organs  of  the  Male  Privet  Hawkmoth.*— Herr  W.  von 
Eeichenau,  as  already  briefly  reported,!  following  up  Dr.  Fritz  Miiller's 
discoveries  in  this  direction,  finds  both  the  j^rivet  and  pine  hawk- 
moths  to  be  provided,  in  the  imago  state,  with  a  special  scent-organ 
at  the  edge  of  the  lower  side  of  the  first  abdominal  segment ;  it  comes 
into  view  on  pressure  of  the  abdomen  of  the  dead  or  living  insect,  and 
consists  of  two  symmetrical  bunches  of  hair-shaped  scales,  which  may 
be  extruded  or  drawn  in.  "When  they  are  extruded  in  a  living  Sphinx 
Uijustri,  a  distinct  musky  scent  is  apparent  at  the  distance  of  half  a 
metre ;  but  ceases  when  they  are  retracted  into  their  fold,  which 
occurs  when  the  insect  is  at  rest.  In  minute  structure  they  are  really 
capillary  tubes,  tapering  gradually  to  points,  and  filled  with  globules 
of  the  scent  substance ;  they  do  not  spring  simply  from  depressions  in 
the  chitinous  skeleton,  as  do  the  ordinary  scales,  but  are  rooted  in, 
and  radiate  from,  a  sac  common  to  them  all ;  this  sac  contains  an 
opaque  white  mass,  and  is  capable  of  being  stretched  by  two  muscles 
attached  to  the  ends ;  in  it  the  hairs  stand  close  together,  united  by  a 
long  band  of  tissue,  and  each  implanted  by  a  pincer-shaped  root. 

The  parts  probably  act  as  follows: — The  moth,  when  excited,  acts  by 
its  nervous  system  on  the  muscles  of  the  segmental  fold,  so  that  they 
open  the  latter,  transforming  it  into  a  boat-shaj)ed  groove ;  at  the 
same  time  the  muscles  of  the  base  of  the  hairs  exercise  a  tension  upon 
the  band  which  unites  the  bases  of  these,  and  causes  them  to  become 
arranged  as  a  radiating,  instead  of  a  converging  group ;  when  these 
muscles  cease  to  act,  the  hairs  converge  again  and  retreat  into  the 
fold.  The  muscles  also  act  by  stretching  the  basal  sac,  so  that  its 
white  contents  are  pressed  against  the  roots  of  the  hairs,  and  entering 
them,  expel  some  of  the  contained  scent  material  through  the  tips.  The 
fact  that  the  hairs  are  never  found  empty  is  explained,  either  by  the 
extreme  diti:usibility  of  small  quantities  of  the  scent,  or  by  its  replace- 
ment by  some  of  the  white  substance  from  the  base. 

The  object  of  these  organs,  of  which  only  a  rudiment  is  present  in 

.  *  '  Kosmos,'  iv.  (1880)  p.  387.  t  Sec  this  JourBal,  ante,  p.  780. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  939 

the  female,  is  probably  to  enable  the  male  to  exercise  a  charm  over  its 
partner. 

The  importance  of  these  modified  scales  is  greater  than  that  of 
the  normal  ones  which  colour  the  wings,  as  these  are  almost  invisible 
in  the  dnsk  ;  and  they  show  an  important  connection  existing  between, 
scent  and  alimentation,  for  it  is  found  that  insects  choose,  as  flowers 
from  which  to  feed,  those  whose  scent  most  nearly  resembles  their 
own.  The  privet  hawk-moth,  for  instance,  prefers  the  musk-scented 
Weigelia,  and  second  to  it,  the  Petunia,  smelling  of  honey  and  musk  ; 
the  Zyrjoence,  which  emit  an  odour  like  that  of  honey,  prefer  the  honey- 
scented  Scabious  best. 

Morphology  of  the  Suspensory  Organs  of  Chrysalids.* — 
M.  Kiinckel  points  out  how  little  knowledge  as  to  this  subject  has 
been  definitely  acquired  sinco  the  time  of  Reaumur.  That  eminent 
naturalist  described  how  the  tail  of  the  chrysalis  was  separated  from 
the  integument  of  the  caterpilhir,  and  bec:ime  attached  by  the  hooks 
with  which  it  is  furnished.  The  author  has  again  investigated  this 
subject,  and  has  come  to  the  conclusion  that  the  chrysalids  have  no 
real  tail  at  all. 

Examining  the  chrysalis  of  Papilionids  or  Nymphalids,  he  has 
seen  that  the  "  tail "  is  formed  by  the  union,  along  the  median  line, 
of  a  pair  of  appendages ;  these  have  each  a  series  of  hooks,  and  they 
belong  to  the  twelfth  ring  of  the  chrysalis,  in  which  there  are  no 
stigmata.  The  appendages  surround  the  extremity  of  the  abdomen 
and  circumscribe  the  anus ;  when  ccdysis  occurs  the  Pajjilio,  on 
losing  its  suspensory  apparatus,  loses  its  anal  appendages.  These 
last  may,  especially  in  many  genera  of  the  Notodontidfe,  take  on  very 
various  forms.  In  Dicranura  they  are  two  retractile  prolongations ; 
in  Platypterijx  they  are  united  for  some  part  of  their  length,  and  arc 
no  longer  retractile  ;  in  Uropus  they  are  somewhat  similar  to  the 
same  parts  in  Dicranura,  but  they  have  a  more  distinct  pediform 
character,  and  they  also  have  a  crown  of  hooks.  Their  power  of 
modification  easily  leads  us  to  see  how  they  became  suspensory  organs. 

Further  information  may  be  gained  by  taking  a  caterpillar,  just 
before  the  period  of  metamorphosis  is  completely  reached ;  the  best 
examples  are  to  be  found  among  species  of  the  genus  Vanessa.  If 
ccdysis  be  hastened  by  treatment  with  alcohol  or  chromic  acid,  it  is 
possible  to  see  that  the  posterior  extremity  of  the  chrysalis  is 
entangled  in  the  twelfth  ring  of  the  caterjjillar,  and  that  the  parts 
which  carry  the  suspenscjry  liooks  (the  "  tail  "  of  many  authors)  aro 
hidden  under  the  integument  of  the  anal  appendages  of  the 
caterpillar. 

It  follows,  therefore,. tliat  the  chrysalids  of  tlio  Lcpidoptcra  attach 
or  suspend  themselves  by  tlie  hooks  of  the  membranous  anal 
apiieudages,  wliich  are  modified  and  adapted  to  the  special  conditions 
of  tlieir  life. 

Preservation  of  the  Chrysalis  from  Cold.t — Dr.  Jousset  do 
Dcll«;snie  was   led   to   the  consideration   of  the  question  whether  tho 

♦  'Omiptes  Uendii.-','  \c\.  (1880)  p.  395. 

t  '  La  Nature,'  viii.  (1880)  1"  si'incstrp,  p.  8H. 


940  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

cocoon  preserves  the  chrysalis  from  extreme  cold  by  finding  in  the 
month  of  March  (1872)  some  cocoons  of  Attacus  cynthia  suspended  to 
the  branches  of  the  trees  in  the  abbey  garden  of  8aint-Germain-des- 
Pres,  Specimens  of  these  moths  had  been  introduced  by  Babinet  in 
1860,  and,  unattended  by  any  one,  had  bred  there  since;  the 
successive  generations  successfully  supporting  the  cold  of  eleven 
winters.  The  winter  of  1871-2  had  been  excessively  severe.  In 
Paris  the  mean  temperature  from  the  8th  to  the  19th  December,  1871, 
had  remained  at  —  9°  C.  and  on  the  21st  the  thermometer  descended 
to  —  20°,  remaining  at  —  18°  for  twenty-four  hours.  Dr.  Bellesme 
was  therefore  surprised  to  find  the  chrysalids  in  a  complete  state 
of  preservation,  the  perfect  insect  emerging  in  due  course.  This 
unlocked  for  resistance  to  congelation  could  only  be  due  to  one 
of  two  causes ;  either  the  almost  absolute  non-conductivity  of  the 
silky  covering,  or  the  production  of  a  notable  quantity  of  heat  on  the 
part  of  the  insect.  The  latter  alternative  seemed  improbable  con- 
sidering the  immobility  of  the  nymph. 

Dr.  Bellesme  proceeded  to  test  the  conductibility  of  the  cocoon,  and 
having  opened  one  and  extracted  the  chrysalis,  he  inserted  the  bulb  of  a 
sensitive  thermometer  in  its  place,  securing  the  cocoon  round  it  with  an 
elastic  band,  and  arranged  it  so  that  the  bulb  of  the  instrument  did  not 
touch  the  cocoon  anywhere.  The  cocoon  thus  prepared  was  intro- 
duced, in  company  with  a  thermometer  for  comparison,  into  a  testing- 
glass,  surrounded  by  a  freezing  mixture.  Before  the  experiment  both 
thermometers  marked  18° ;  five  minutes  after  their  introduction  into 
the  test-glass  they  were  withdrawn,  when  both  marked  9°.  On 
suspending  them  in  the  oj)en  air  the  comparison  thermometer  rapidly 
rose,  and  in  a  few  moments  had  regained  its  former  level  of  18° ; 
after  ten  minutes,  the  thermometer  which  had  the  cocoon  tied  over  it 
stood  at  the  same  point. 

If,  therefore,  the  nymph  resists  congelation,  it  does  so  by  virtue 
of  a  continuous  and  considerable  disengagement  of  heat.  It  is 
extremely  probable  that  this  heat  is  produced  at  the  expense  of  the 
organic  transformations  which  take  place  within.  There  is  the  dis- 
appearance of  certain  muscles  which  have  served  the  larva  and  the 
formation  of  new  ones  to  be  used  by  the  perfect  insect.  But  the  muscu- 
lar system  of  the  larva  is  far  more  considerable  than  that  of  the 
perfect  insect ;  all  the  heat  rendered  available  by  the  destruction 
of  the  old  muscles  is  not,  therefore,  used  up  in  the  construction  of 
new  ones.  Moreover,  uric  acid  and  its  derivatives  are  very  abun- 
dant in  the  recently  metamorphosed  insect,  another  sign  of  the 
existence  of  active  combustion  during  the  nymphal  period.  To 
these  organic-chemical  phenomena  must  then,  apparently,  be  attri- 
buted the  facility  with  whicli  insects,  in  course  of  transformation, 
support  prolonged  low  temperatures. 

Wing-muscles  of  Insects.* — N.  Poletaiew  describes  the  difference 

between  the  wing-muscles  of  the  Lepidoptera  and  of  the  Libellulidse. 

Those  of  the  former  may  be  arranged  in  three  groups :  (1)  a  median 

*  'Zool.  Anzeig.,'  iii.  (1880)  p.  212. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  941 

paired  dorsal  muscle  ;  (2)  lateral  and  dorsoventral  muscles  of  the 
meso-  and  metathoras  ;  {?■)  median  dorsoventral  whicli  raise,  while 
the  other  two  sets  depress,  the  wings.  Only  two  muscles  are  inserted 
by  means  of  tendons  into  the  wings,  the  rotation-axes  of  which  lie 
parallel  to  the  axis  of  the  body. 

The  Libellulida3  want  the  median  wing-muscle;  each  of  their 
chief  muscles  is  provided  with  one  or  two  very  small  accessory 
muscles.  Owing  to  the  structure  of  their  wings  the  muscles  are 
inserted  directly  at  the  base  of  the  thickened  nervures  of  the  wing, 
and  all  have  a  superior,  and  some,  in  addition,  an  inferior  tendon, 
while  the  rotation  axes  of  their  wings  are  set  at  an  angle  of  from  30° 
to  55°  to  the  longitudinal  axis  of  the  insect  itself. 

Salivary  Glands  of  the  Odonata.* — The  salivary  glands  of  the 
Odonata  (Dragon-flies),  although  denied  by  entomologists,  exist,  says 
Herr  Poletaiew,  in  all  the  species  of  the  three  families  of  this  sub- 
order of  insects. 

In  their  structure  they  present  the  characters  common  to  acinous 
glands,  and  consist  of  lobules,  or  glandular  grains  (acini),  whose 
excretory  canals  unite  by  degrees  into  two  principal  ducts,  one  for 
each  gland.  These  lobules,  elongated,  and  of  an  o-\'al  form,  are 
more  numerous  in  the  ^schnidaj  and  Libellulidas  than  in  the 
Agrionidee.  ^schna  grandis  L.,  for  example,  has  more  than  150 
of  them,  whilst  Lcstes  sponsa  Hansen,  has  only  sixty.  In  tlie  two 
first-named  families,  moreover,  these  lobules  are  closer,  and  more 
interlaced  by  the  trachea3. 

The  salivary  glands  are  situated  in  the  prothorax,  near  or  over  the 
first  thoracic  ganglion.  Generally  they  are  in  front  of  the  latter,  and 
at  the  same  time  in  front  of  the  anterior  depressor  of  the  wing.  In 
some  Libellulidaj — the  smallest  ones — they  arc  further  back,  reaching 
even  to  the  elevator  of  the  anterior  wing  (e.  g.  Libcllala  scotica  Donov.). 
The  whole  cluster  affects  an  oval  form.  Each  of  the  two  principal 
canals,  after  reaching  the  interior  of  the  head,  enlarges  into  a  sac  or 
bladder,  oval  or  spherical  in  form,  then  is  continued  as  a  very  short 
tube,  and  meeting  its  congener,  constitutes  a  single  duct  which  opens 
directly  into  the  mouth  under  the  tongue  (ligula). 

Mode  of  Respiration  in  the  Larvae  of  the  Genus  Euphoea 
(Libellulidae).! — Mr.  II.  A.  llagen  describes  this  as  follows : — 

On  each  side  of  segments  1-8  of  the  abdomen  is  a  conical 
branchial  apjiendago  with  unravelled  edges ;  three  strong,  equal, 
cylindrical,  caudal,  branchial  appendages ;  the  rectal  branchiio  formed 
of  three  simple  columns. 

The  existence  of  latei"ul  branchial  abdominal  appendages  is  known 
in  tlio  genus  Sialis,  but  is  altogether  unique  in  the  Odonata. 
Kespiration  in  the  larva  of  Euphijea  is  thus  possible  in  four  different 
manners:  (1)  by  stigmata,  two  on  the  thorax  and  eight  on  tlie 
abdomen ;    (2)  by  lateral  branchial   ai)pendages  well  provided   with 

•  ^CJomptea  RtiKhis,'  xci.  (1880)  p.  129. 

t  '  Coinptcs  Kondiis  S(m\  Kntnmol.  Bclg.,'  iik  etinp  of  1st  May,  1S80. 

VOL.  III.  3  n 


942  RECORD    OP    CURRENT    RESEARCHES   RELATING    TO 

tracheae ;  (3)  by  caudal  brancTiial  appendages  equally  well  provided 
with  trachcfe  ;  (4)  by  rectal  branchife  formed  of  three  columns  in  the 
mucous  system  of  the  rectum,  well  provided  with  trachece.  No  doubt 
the  four  kinds  of  respiration  do  not  act  simultaneously,  and  the 
stigmata  of  the  abdomen  j)robably  never,  as  they  only  receive  a 
simple  tracheal  branch,  but  the  stigmata  of  the  prothorax  are  provided 
internally  with  numerous  well-developed  tracheae,  and  perhaps  serve 
for  the  expulsion  of  used  air. 

Mr.  E.  MacLachlan,  in  commenting  *  upon  the  preceding,  de- 
scribes it  as  "  a  most  important  physiological  discovery,  and  showing 
how  little  is  yet  known  of  the  structure  of  the  larvae  of  dragon-flies. 
The  beautiful  genus  Euplicea  inhabits  tropical  Asia  and  the  islands  of 
the  Eastern  Archipelago." 

Poduridae  from  Switzerland. f — Dr.  G.  Haller  records  the  capture 
of  four  species  of  Poduridae,  two  from  the  canton  of  Berne,  and 
two  apparently  from  near  Zurich. 

»0f  the  former  cases,  one  is  that  oi  Achoreutes  purjmrascens  Lubbock, 
which  occurred  over  an  extent  of  10  metres  of  a  road,  in  the  puddles ; 
the  other,  that  of  an  apparently  new  species  of  the  same  genus,  which 
was  found  in  patches  on  damp  earth  of  some  millimetres  in  depth, 
and  in  one  instance  of  about  16  square  inches  in  extent.  The  name 
A.  Scliluppii  is  proposed  for  this  form,  which  is  distinguished  by  the 
large  size  of  its  head  (one-third  the  length  of  the  body,  which  does  not 
exceed  1  millimetre).  The  antennte  are  very  thick,  and  dark  violet 
in  colour  ;  the  head  is  light  reddish  brown  ;  the  body  is  remarkably 
constricted  between  the  sixth  and  seventh  segments,  and  varies  from 
brick-red  colour  to  near  that  of  A.  purpurascens.  The  whole  is 
covered  with  short  bristles,  which  are  of  larger  size  on  the  abdomen. 

The  new  genus  Lubhockia  is  formed  to  contain  a  species  found  in 
moss  near  Zurich,  and  closely  allied  to  Achoreutes.  The  genus  is  thus 
defined  :  "  Body  cylindrical,  segments  subequal.  Eyes  ?  Antennae 
extended,  longer  than  the  head,  slender,  five-jointed.  Accessory  claws 
on  the  four  front  feet  very  small,  scarcely  to  be  distinguished ; 
plainer  on  the  third  pair.  No  scales  or  knobbed  hairs,  but  two  strong, 
slightly  bent  pairs  of  spines,  near  the  hind  margin  of  the  body. 
Leaping-fork  very  small."  The  species  is  named  L.  ccerulea.  The 
body  is  dark  blue  above,  lighter  below ;  the  S2)ines  are  golden  yellow. 
Hairs  occur,  at  some  distance  apart,  on  the  legs  and  on  the  upper  part 
of  the  body.     Total  length  1^  millimetre. 

A  new  species  of  Isotoma,  I.  Turicensis,  is  described,  from  moss  in 
the  same  locality  as  the  LuhbocMa.  Its  back  is  blue-black,  the  ventral 
surface  lighter ;  anal  spring  and  legs  below  the  coxae,  almost  colour- 
less. Terminal  segment  of  fork  ending  in  three  tiny  warts.  Body 
clothed  with  closely  set,  colourless  hairs,  mixed  with  a  smaller 
number  of  bristles.  Two  large  bristles  near  the  hind  edge  of  the  legs. 
Length  about  1  millimetre.     Closely  allied  to  I.  arborea  Lubbock. 

*  '  Eutomol.  Mon.  Mag.,'  vii.  (1880)  p.  90. 

t  'MT.  Schweiz.  Entomol.  Ges.,'  vi.  (1880)  p.  1. 


INVEBTEBEATA,   CllYPTOGAMIA,   MICROSCOPY,   ETC.  943 

p.   Myriapoda. 

Segments  of  the  Geophilidse.* — Dr.  Sseliwanoff  describes  the 
structure  of  the  segmeuts  iu  these  forms. 

Each  body-segment,  though  bearing  only  a  single  pair  of  legs,  is 
clearly  enough  made  up  of  two  segments.  In  these  the  numerous 
small  lamelho  which  form  the  lateral  jiarts,  are  arranged  in  two 
transverse  series.  The  number  of  these  lamella)  is  greatest  in  the 
lowest  forms,  while  in  those  more  highly  developed  the  lamellae 
either  fuse  with  one  another,  or  partially  disappear.  The  same 
remark  applies  to  the  distinctness  of  the  two  component  segments 
connected  with  each  pair  of  appendages.  The  author  is  also  reported 
to  have  made  some  observations  on  Bothriogaster. 

7-  Arachnida. 

Poison-organs  of  the  Spiders.f — M.  MacLeod,  in  this  prelimi- 
nary communication,  deals  chiefly  with  the  histological  characters  of 
these  organs.  Among  the  forms  examined  are  Epeira  diadema,  Agelena 
labyrhithica,  and  Tegcnaria  domestica. 

In  all  these  forms  there  are  two  j)oi son-glands,  each  of  which  presents 
a  pyriform  glandular  body,  invested  by  a  layer  of  spirally  arranged 
muscular  fibres,  and  an  excretory  canal,  which  opens  at  the  extremity 
of  the  chelicorse.  The  gland  is  either  jilaced  in  the  cephalothorax, 
immediately  below  the  dorsal  integument,  or  partly  iu  the  cephalo- 
thorax and  partly  in  the  basal  joint  of  the  cheliceras.  Its  wall  is  seen 
to  be  composed,  from  without  inwards,  of  the  following  layers  : — 
(a)  a  muscular  tunic ;  (h)  a  glandular  epithelium.  The  former  is 
made  up  of  a  single  layer  of  striated  fibres,  and  is  everywhere  of  the 
same  thickness.  The  transverse  striation,  though  always  distinctly 
apparent,  is  but  feebly  marked.  The  longitudiiial  strife  are,  on  tho 
other  hand,  very  distinctly  visible.  Tho  numerous  nuclei  are  very 
regularly  arranged  in  longitudinal  rows,  and  as  many  as  four  rows  may 
be  made  out  iu  a  single  fibre.  On  either  side  of  the  muscular  layer 
there  is  an  investment  of  connective  tissue,  and  they  arc  connected 
together  by  regularly  arranged  septa,  which  traverse  and  scjiaratc 
from  one  anf)ther  the  longitudinal  constituents  of  tho  muscular  layer. 
The  elements  of  the  glandular  epithelium  vary  according  to  tho 
ago  and  species  of  the  specimen  under  examination.  In  a  young 
Agclcna  they  are  cylindrical,  with  deeply  set  nuclei ;  in  the  adult  the 
cells  are  more  distinctly  calyciform,  and  there  is  a  narrow  tube,  three 
or  four  times  as  long  as  tho  protoplasmic  portion  of  tho  cell. 
Numerous  intermediate  stages  between  tho  extreme  forms  are  to  bo 
noted. 

The  excretory  canal  arises  from  tho  narrowest  part  of  the  gland, 
but  the  Inuscular  tunic  is  formed  of  striated  fibres,  which  are  nrranged 
s[)iriilly  around  the  organ,  and  which  are  much  more  delicate  and 
more  widely  separated  from  one  anotlier.  The  epithelial  layer,  which 
invests  tho  inner  face  of  tho  internal  layer  of  councctivo  tissues,  is 

♦  'Zool.  Anzi'ip;.,'  iii.  (1880)  p.  1C7. 

t  '  IJull.  Acud  R.  Sci.  Belg.,'  1.  (1880)  pp.  llO-i:?. 

3    R   2 


944  EECORD   OF    CURRENT    RESEARCHES    RELATING    TO 

made  up  of  very  small  cells,  which  are  cubical  in  form  and  regular  in 
arrangement. 

Pentastomum  polyzonum.* — Professor  Jeffrey  Bell  has  been  able 
to  rediscover  this  species  in  an  African  python  which  died  in  Womb- 
well's  menagerie.  The  species  was  shortly  described  and  well  figured 
by  Dr.  Harley  in  the  '  Proceedings '  of  the  Zoological  Society  for 
1857,  the  specimen  being  from  the  collection  of  Dr.  Sharpey,  but 
having  no  history.  A  careful  comparison  of  the  two  specimens  in  the 
British  Museum  with  Dr.  Harley's  figure,  and  an  examination  of 
other  species,  seems  to  show  that  the  number  of  the  rings  of  the  integu- 
ment is  pretty  definite  for  each  form  ;  P.  polyzonum  having  nineteen 
rings,  and  P.  annulatum  Baird  (described  by  Harley  under  the  name 
of  P.  muUicinctum),  having  twenty-seven  or  twenty-eight. 

5.  Crustacea. 

Anal  Respiration  of  the  Crustacea,  t — In  a  former  note  J  Mr.  M. 
Hartog  suggested  that  the  zoea  larva  of  the  higher  Crustacea  would, 
on  examination,  prove  to  breathe  in  the  same  way  as  the  Copepoda. 
Zoeas  of  Cancer,  and  probably  of  some  species  of  prawn,  have  con- 
firmed this  amply.  The  respiratory  diastole  and  systole  of  the  rectum 
with  rhythmical  openings  of  the  anus,  are  thoroughly  well  marked. 
It  may  here  be  noted  that  in  carmine  stainings  of  the  entire  Copepoda 
the  stain  does  not  diffuse  through  the  integument,  but  up  through  the 
rectum  in  the  first  instance.  The  power  of  dialysis  through  the 
chitinized  integument  is  slight,  if  at  all  existent.  Now  that  another 
place  is  found  for  the  respiratory  function,  it  may  be  denied  to  the 
expanded  pleura  of  the  carapace. 

This  constancy  of  function  in  the  anus  is  remarkable,  and  indi- 
cates that  the  gills  which  characterize  so  many  of  the  higher  Crustacea 
are  secondary  formations,  long  posterior  to  the  differentiation  of  the 
class.  As  to  their  origin  ?  They  are  probably,  in  all  cases,  modifica- 
tions of  those  processes  of  the  appendages  which  primitively  bring 
about  nutritive  currents. 

Genealogy  of  the  Mysid8e.§ — Herr  Czernjawsky  has  given  an 
account  of  his  speculations  on  this  subject.  He  has  been  examining 
thirty-two  species,  most  of  which  are  new,  and  has  noted  very  remark- 
able variations  in  the  locomotor  organs,  and  in  the  parts  of  the  mouth, 
as  well  as  in  the  brood-cavity  of  the  mother.  He  comes  to  the  con- 
clusion that  the  Mysidae  form  a  side-branch  of  the  great  Crustacean 
phylum,  and  that  this  branch  began  at  the  same  point  as  that  of  the 
Macrura,  which,  for  its  part,  gave  rise  to  the  Brachyura  and  the 
Anomura.  The  fact  that  the  auditory  organ  of  the  Mysidae  is  placed 
in  the  caudal  appendages,  and  in  the  Macrura  at  the  base  of  the 
antennae,  seems  to  prove  to  the  author  that  the  latter  are  not  derived 
from  the  former. 

*  '  Ann.  and  Mag.  Nat.  Hist.,'  vi.  (1880)  p.  173. 
t  '  Quart.  Journ.  Micr.  Sci.,'  xx.  (1880)  p.  485. 
t  See  this  Journal,  ante,  p.  633. 
§  'Zool.  Anzeig.,'  iii.  (1880)  p.  213. 


INVERTEBKATA,    CRYPTOGAMIA,   MICROSCOPY,   ETC.  945 

The  ancestor  of  the  two  groups  is  to  he  found  in  the  Mysis-stage 
of  the  Decapoda  (Fritz  Miiller).  The  ancestors  were  pelagic  forms, 
with  three  flagella  to  the  superior  antennas,  and  with  biramose  ab- 
dominal swimming  feet  in  both  sexes.  So  far  as  the  present  existing 
Mysidse  are  concerned  the  third  flagellum  is  only  retained  in  the 
male  of  Podopsis.  This  is  somewhat  remarkable,  as  this  genus  is 
one  of  the  most  retrograde  of  its  group.  In  the  other  genera  there 
is  no  indication  of  it  whatever.  Among  the  Macrura,  Palcemon  has  a 
third  flagellum,  more  or  less  well  developed,  and  in  the  more  lowly 
rejiresentatives  it  is  still  well  marked.  The  abdominal  feet  are  still 
swimming  organs  in  the  Macrura,  but  in  forms  of  Mysidae  which  were 
examined,  those  parts  never  had  that  function  in  both  sexes.  In  the 
former  the  right  and  left  mandibles  are  equal,  but  in  all  Mysidae  they 
are  unequal,  and  are  generally  very  different. 

Basing  his  argument  on  the  conclusion  to  which  he  has  arrived, 
that  where  the  male  differs  most  from  the  primitive  form,  the  group  to 
which  it  belongs  is  progressing,  and  that,  on  the  contrary,  where  the 
female  exhibits  the  most  marked  divergence,  the  group  is  retrograding, 
the  author  concludes  that  the  Mysidae  are  degenerating.  This  may 
be  shown  by  the  abdominal  appendages,  for  in  the  male  there  is  a 
gradual  series  of  atrojjhy,  while  in  the  female  they  are  nearly  always 
comi^letely  rudimentary  ;  so,  too,  the  male  Mysidae  often  retain  their 
pelagic  habitat. 

The  author  concludes  with  an  indication  of  the  characters  by 
means  of  which  the  relations  of  the  different  genera,  and  their  history, 
are  to  be  made  out. 

Nest-building  Amphipods* — Mr.  S.  J.  Smith,  in  a  paper  on  some 
Amphipods  described  by  T.  Say,  states  that  the  tubes  which  certain 
species  make  to  live  in  are  to  a  great  extent  formed  of  pellets  of  their 
excreta. 

In  1874  he  watched  carefully  the  process  of  constructing  the 
tubes  in  several  species  of  Amphipoda.  Microdentopus  grandimaniis 
(M.  minax  Smith)  was  a  particularly  favourable  subject  for  observa- 
'tion. 

When  captured  and  placed  in  a  small  zoophyte  trough  with  small 
branching  algae,  the  individuals  almost  always  proceeded  at  once 
to  construct  a  tube,  and  could  very  readily  be  observed  under  the 
Microscope.  A  few  slender  branches  of  the  alga  were  pulled  toward 
each  other  by  means  of  the  antennae  and  gnathopods,  and  fastened  by 
threads  of  cement  spun  from  branch  to  branch  by  the  first  and  second 
pairs  of  perajopods.  The  branches  were  not  usually  at  once  brought 
near  cnougli  together  to  serve  as  the  framework  of  the  tube,  but  were 
gradually  brouglit  together  by  jjulling  them  in  and  fastening  tliom  a 
little  at  a  time,  until  they  were  brought  into  their  proper  position, 
where  they  were  firmly  held  by  means  of  a  thick  network  of  fine 
threads  of  cement  spun  from  branch  to  branch.  After  the  tube 
had  assumed  very  nearly  its  completed  form,  it  was  still  usually 
nothing  but  a  transparent  network  of  cement  threads  woven  among  the 

♦  '  Trans.  Connect.  Acud.,'  1860.     Soo  '  Nature,'  x.\ii.  (1880)  p.  51)5. 


946  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

branches  of  the  alga,  though  occasionally  a  branch  of  the  alga  was 
bitten  off  and  added  to  the  framework ;  but  very  soon  the  animal 
began  to  work  bits  of  excrement  and  bits  of  alga  into  the  net.  In  this 
case  the  pellets  of  excrement,  as  passed,  were  taken  in  the  gnathopods 
and  maxillipeds,  and  apjiarently  also  by  the  maxillae  and  mandibles, 
and  broken  into  minute  fragments  and  worked  through  the  web,  upon 
the  outside  of  which  they  seemed  to  adhere,  partially  by  the  viscosity 
of  the  cement  threads,  and  partially  by  the  tangle  of  threads  over 
them.  Excrement  and  bits  of  alga  were  thus  worked  into  the  wall  of 
the  tube  until  the  whole  animal  was  protected  from  view,  while,  during 
the  whole  process,  the  spinning  of  cement  over  the  inside  of  the  tube 
was  kept  up. 

When  spinning  the  cement  threads  within  the  tube,  the  animal  was 
held  in  place  on  the  ventral  side  by  the  second  pair  of  gnathopods  and 
the  caudal  appendages,  the  latter  being  curved  beneath  the  anterior 
portion  of  the  pleon,  and  on  the  dorsal  side  by  the  third,  fourth,  and 
fifth  pairs  of  persoopods  extended  and  turned  up  over  the  back,  with 
the  dactyli  turned  outward  into  the  web.  The  sj)inuing  was  done 
wholly  with  the  first  and  second  peraeopods,  the  tips  of  which  were 
touched  from  point  to  point  over  the  inside  of  the  skeleton  tube  in  a 
way  that  recalled  strongly  the  movements  of  the  hands  in  playing  upon 
a  piano.  The  cement  adhered  at  once  at  the  points  touched  and  spun 
out  between  them  in  uniform  delicate  threads.  The  threads  seemed 
to  harden  very  quickly  after  they  were  spun,  and  did  not  seem,  even 
from  the  first,  to  adhere  to  the  animal  itself. 

Development  of  Orchestia  Montagui  and  0.  Mediterranea.* — 
Herr  TJljanin  gives  an  account  of  his  observations  on  the  early  stages 
in  the  development  of  these  "  sand-fleas." 

He  deals  especially  with  the  formation  of  the  blastoderm  and  of 
the  germinal  layers.  He  was  unable  to  detect  the  germinal  vesicle. 
Sections  showed  in  each  of  the  four  cleavage  spheres  a  stellate  cell ; 
these  cells  jjass  to  the  periphery  gradually.  They  are  of  considerable 
size,  and  consist  of  a  granular  j)rotoplasm,  which  gives  off"  more  or  less 
long  filamentous  processes.  Their  nucleus  is  large,  and  there  are  also 
two  or  three  nucleoli.  It  is  they  alone  which  give  rise  to  the  later 
blastoderm  cells.  At  the  time  when  there  are,  altogether,  thirty-two 
cells,  the  cleavage  spheres  begin  to  get  indistinct  boundaries,  and,  a  little 
later  on,  the  limits  between  them  disappear  altogether.  The  smaller 
and  peripheral  cells  which  go  to  form  the  blastoderm  become  closely 
appressed,  and  the  whole  mass  takes  on  a  polygonal  form.  This  por- 
tion, when  complete,  covers  over  nearly  two-thirds  of  the  surface  of 
the  egg,  and  consists  of  cubical,  somewhat  elongated  cells.  The 
mesoderm  commences  to  be  developed  before  the  ectoderm  is  com- 
pletely formed.  It  clearly  enougli  owes  its  origin  to  that  layer,  aiising 
close  to  the  edge  of  the  blastoderm  disk  in  the  form  of  a  small  rounded 
thickening.  In  the  course  of  growth  it  reaches  to  the  oj^posite  side  of 
the  egg,  or  to  that  at  which  the  dorsal  region  of  the  animal  is,  later 
on,  developed.     Now  is  shed  the  so-called  cuticle  of  the  blastoderm. 

*  '  Zool.  Anzeig.,'  iii.  (1880)  p.  163. 


INVERTEBRATA,   CRYPTOGAMIA,    MICROSCOPY,   ETC.  947 

The  "  spherical  organ"  is  regarded  by  the  author  as  being  the 
homologue  of  the  shell-gland  of  the  Mollusca ;  both  are  local  invagina- 
tions, and  while  one  gives  rise  to  the  shell  the  other  forms  the  blasto- 
derm cuticle.  It  has  also  a  relation  to  the  formation  of  the  ectoderm 
and  mesoderm,  for  at  the  time  when  the  first  signs  of  the  extremities 
become  apparent,  and  the  spherical  organ  has  taken  up  a  definite  posi- 
tion, tlie  yolk,  lying  below  this  last,  begins  to  break  up  into  spheres, 
and  this  change  gradually  extends  over  the  mass.  It  would  seem 
probable  that  these  "  Ballen  "  have  their  origin  in  the  spherical  organ, 
and  it  may  be  that  the  cells  of  the  ectoderm  arise  from  the  base  of  the 
invagination. 

Structure  of  the  Eye  of  Limulus.* — Dr.  A.  S.  Packard,  jun., 
writes : — 

The  eyes  of  the  horse-shoe  or  king  crab  are  four  in  number,  con- 
sisting of  a  pair  of  compound  eyes  situated  on  the  side  of  the  head, 
and  a  pair  of  small,  sim2)le  eyes  on  the  front  of  the  head.  As  described 
by  A.  Milne-Edwards  and  Owen,  the  optic  nerves  to  these  eyes  are 
very  long,  and  close  to  each  eye  subdivide  into  an  irregular  plexus  of 
fine  nerves,  a  branch  being  distributed  to  each  facet  composing  the 
compound  eye.  The  structure  of  the  eye  is  very  unlike  that  of  any 
other  Arthropod  eye.  The  cornea  is  simjily  a  smooth  convex  portion 
of  the  integument,  which  is  much  thinner  than  the  adjoining  part  of 
the  chitinous  skin.  There  are  no  facets,  the  cornea  externally  being 
structureless,  simply  laminated  like  the  rest  of  the  integument.  On 
the  internal  side  of  the  cornea  are  a  series  of  solid  chitinous  conical 
bodies,  separated  from  one  another  by  a  slight  interspace,  and  in  form 
resembling  so  many  Minie-rifle  balls.  The  conical  ends  of  these  solid 
cones  project  free  into  the  interior  of  the  body,  and  are  enveloped  in 
a  dense  layer  of  black  pigment.  Within  the  base  of  these  cones  are 
secondary,  shallow,  cup-like  bodies,  or  sliallow  secondary  cones.  It 
is  these  primary  cones  which,  seen  through  the  smooth,  convex,  trans- 
lucent cornea,  give  the  appearance  of  a  faceted  surface  to  the  external 
eye. 

All  the  parts  thus  far  described,  except  the  pigment  layer,  are 
moulded  with  the  rest  of  the  crust ;  and  the  large,  long,  slender  cones 
can  be  easily  seen  by  viewing  a  piece  of  the  cast-off  eye,  the  solid 
cones  being  seen  projecting  from  the  inner  surface  of  the  cast-off 
cornea. 

The  internal  structure  of  the  eye  is  very  simple.  There  are  no 
cones  ami  no  rods,  but  a  branch  of  the  optic  nerve  impinges  directly 
upon  the  end  of  the  solid  chitinous  cone,  as  determined  by  removing 
the  layer  of  pigment  with  dilute  jKjtash,  and  treating  the  section  with 
acetic  acid,  and  then  stiiiiiing  witli  picrocannine.  So  far  as  the 
uutlior  can  ascertain,  no  Artliropod  eye  is  so  simple  as  that  of  Litnnlus. 

Tho  observations  wore  based  on  a  study  of  the  lobstoi-'s  eye  from 
preparations  of  very  great  beauty  and  delicacy,  made  for  Iiini  by  Mr. 
N.  N.  Mason,  of  Pi'ovidcnco,  who  has  also  made  beautiful  sections  of 
the  Limulua  oyc,  after  treating  them  in  various  ways.     Tho  question 

♦  '  Am.  Natnriil.,'  xiv.  (1880)  p.  212. 


948  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

as  to  the  nature  of  the  solid  cones  he  is  not  yet  prepared  to  settle. 
Are  they  crystalline  lenses  or  only  analogous  organs  ?  Can  the  horse- 
shoe crab  distinguish  objects  ?  He  doubts  if  its  eyes  enable  it  to 
more  than  distinguish  between  the  light  and  darkness. 

Eye  of  Trilobites.*  —  Dr.  Packard  has  also  investigated  the 
internal  structure  of  the  hard  parts  of  the  eye  of  Trilobites  ;  only  the 
entire  eye,  the  external  anatomy  of  the  cornea,  and  the  form  and 
number  of  the  facets  having  been  previously  described  and  figured  by 
Burmeister,  Barrande,  and  others. 

From  the  facts  presented  it  would  seem  evident  that  the  hard 
parts  of  the  eye  of  the  Trilobites  and  of  Limuliis  are,  throughout, 
identical.  The  nature  of  the  soft  parts  will,  as  a  matter  of  course, 
always  remain  problematical,  unless  the  dark  line  which  seems  to 
run  across  from  one  lens  to  another  really  represents  the  outer 
edge  of  the  pignient  of  the  retina ;  but  however  this  may  be,  judging 
by  the  identity  in  structure  of  the  solid  parts,  we  have,  reasoning 
by  analogy,  good  evidence  that  most  probably  the  eye  of  the  Trilo- 
bites had  a  retinal  mass  like  that  of  Limuhis,  and  that  the  numerous 
small  branches  of  the  long,  slender,  optic  nerve  (for  such  it  must 
have  been)  impinged  on  the  ends  of  the  corneal  lenses.  It  has 
been  shown  by  Grenacher  and  the  author,  that  the  eye  of  Limulus 
is  constructed  on  a  totally  different  plan  from  that  of  other  Arthro- 
pods ;  and  he  now  feels  authorized  in  claiming  that  the  Trilobite's  eye 
was  organized  on  the  same  plan  as  that  of  Limulus ;  and  thus  when 
we  add  the  close  resemblance  in  the  larval  forms,  in  the  general 
anatomy  of  the  body-segments,  and  the  fact  demcmstrated  by  Mr. 
Walcott  that  the  Trilobites  had  jointed  round  limbs  (and  probably 
membranous  ones),  we  are  led  to  believe  that  the  two  groups  of 
Merostomata  and  Trilobites  are  subdivisions  or  orders  of  one  and 
the  same  subclass  of  Crustacea,  for  which  he  previously  proposed  the 
term  PalfBOcarida. 

New  Entomostraeon  from  Afghanistan.f — Dr.  F.  Day  describes 
(from  a  collection  made  by  Dr.  Duke  in  Afghanistan)  a  new  entomos- 
traeon— Ajnis  dukianus — captured  in  a  pond  near  Kelat  in  1877. 

Superiorly  the  general  colour  of  the  carapace  is  olive,  the  spinous 
projections  sienna,  and  the  body  and  tail  dull  yellow.  The  largest 
examjjle  is  1  •  4  inch  long,  0  •  6  inch  in  width,  while  the  caudal  aj)pen- 
dages  are  0  •  7  inch  in  length.  The  caudal  portion  of  the  body  is 
twice  as  long  as  the  carapace.  The  segments  of  the  body  have  each  a 
transverse  row  of  from  six  to  eight  short,  spinous  elevations  directed 
backwards,  the  lateral  spine  being  that  most  developed.  The  joints  of 
the  caudal  appendage  are  similarly,  but  less  strongly  armed,  to  those  of 
the  body.  The  entire  extent  of  the  semilunar  notch  at  the  posterior 
extremity  of  the  carapace  is  armed  with  very  fine  and  short  needle- 
like points,  all  being  of  about  the  same  size ;  while  under  the  Micro- 
scope the  hind  portion  of  the  carapace's  outer  edge  is  also  seen  to  bo 
minutely  and  evenly  armed  with  fine  points. 

*  '  Am.  Natural.,'  xiv.  (1880)  p.  503.     (1  fls^s.) 
t  '  rroc.  Zool.  Soc.  Lond.,'  1880,  p.  392.     (1  fig.) 


INVERTEBKATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  949 

The  great  comparative  length  of  the  body  of  this  species  distin- 
guishes it  from  known  forms  of  Apis,  while  its  carapace  is  relatively 
smaller  and  armature  less  developed. 

Vermes. 

Genital  Glands  and  Segmental  Organs  of  the  Polychseta.* — In 
continuing,  in  a  further  number  of  M.  Lacazc-Duthiers'  '  Archives,' 
his  further  account  of  this  subject,  M.  Cosmovici  deals  with  it  in  a 
comparative  manner. 

The  result  of  his  researches  may  be  thus  summed  up  : — Taking 
for  exami)Ics  Arenicola  ptscatorum  and  Terehella  giganfea,  we  find  that 
the  "  pouches  of  the  body-cavity  "  are  comijosed  of  two  jmrts  ;  one  is 
voluminous  and  glandular,  comparable  to  the  molluscan  organ  of 
Bojanus ;  plexuses  of  blood-vessels  are  found  in  its  wall,  its  interior 
is  lined  by  a  very  thick  layer  of  pigmented  cells,  the  most  superficial 
of  which  have  vibratile  cilia ;  the  organ  communicates  with  the 
interior  by  a  pore,  and  crystals  of  uric  acid  are  to  be  found  in  it. 
The  second  portion  is  a  bell-shai:)cd  organ,  with  two  lips ;  one  of 
these,  more  or  less  richly  ciliated,  is  traversed  by  a  blood-vessel ;  the 
organ  is  continuous  with  a  funnel  of  varying  length  ;  connected  with 
the  glandular  portion,  it  is  obviously  a  segmental  organ,  and  serves  as 
the  oviduct  in  the  female  and  the  sperm-duct  in  the  male.  In  the 
Serpulidse  and  Hermellidte  the  two  jiarts  are  distinct.  In  the 
sedentary  Annelids  we  find,  then,  two  kinds  of  organs.  The  organs 
of  Bojanus  vary  in  their  number  and  disposition  in  the  different 
genera  and  species.  The  segmental  organs,  which  may  or  may  not  be 
connected  with  the  organs  of  Bojanus,  similarly  diftcr  in  different 
forms ;  their  function  is  to  collect  the  generative  products  which  float 
in  the  coelom  and  to  pass  them  outwards.  The  more  the  animal 
rises  in  the  scale  of  development  of  the  Annelidan  type  the  closer  is 
the  connection  between  the  two  sets  of  organs ;  the  sedentary  are 
more  elaborately  developed  than  the  errant  forms,  and  thus  it  is  in 
them  that  the  two  parts  are  more  closely  connected.  With  the 
exception  of  the  two  families  already  mentioned — the  Serpulida;  and 
the  Hermellidie — the  segments  of  the  body  greatly  lose  their  "  indi- 
viduality." 

As  to  the  genital  glands,  the  researches  of  the  author  have 
convinced  him  that  there  are  two  organs  of  this  kind,  both  male  and 
female,  and  that  tliey  are  constant  in  position.  Only  in  the  "  beau 
temps  "  do  they  become  visible ;  they  are  racemose  and  attached  to  a 
blood-vessel  ;  each  acinus  of  the  glnnd  is  surrounded  by  a  delicate 
membrane,  capable  of  distension.  The  nuclei  seen  in  the  contained 
pr()to2)laHra  are  the  germinal  spots  of  tho  future  ova ;  around  these 
nuclei  the  amorphous  pr()toi)lasm  becomes  collected,  and  the  ova  are 
driven  forward  by  the  develoinnent  of  fresh  protophism  at  the  base  of 
each  acinus.  The  ripe  eggs  fall  into  the  cavity  of  the  body  and 
CKcai)C  to  the  exterior  through  the  ducts  of  the  segmental  organs. 
Tlie  testes  present  a  similar  history.     The  genital  glands  are  to  be 

*  Sec  this  .IiMunal,  ui/c,  p.  63."). 


950  RECOBD    OF    CURKENT    RESEARCHES   RELATING    TO 

found  in  young  specimens,  and  it  may  be  of  interest  to  add  that 
Arenicola  especially  lends  itself  to  tliese  investigations. 

Spirorhis  communis  is  to  be  added  to  the  few  species  of  Polychseta 
which  are,  as  yet,  known  to  be  hermaphrodite.  The  author  thinks 
that  further  investigations  will  show  that  the  same  is  true  of  many 
other  species  of  that  genus. 

Not  much  is  known  as  to  the  mode  of  oviposition.  Terehella 
conchilega  extrudes  its  ova  one  by  one ;  after  a  little  it  changes  its 
place,  turns  over  on  to  the  other  side,  and  lays  more ;  it  probably 
lays  its  eggs  in  different  places.  Many,  and  esiDCcially  the  Opheliadae, 
deposit  their  eggs  in  gelatinous  masses,  in  the  centre  of  which  there 
is  a  water-tube.  In  this  case  it  appears  probable  that  the  male 
afterwards  visits  the  ova,  and  that  the  sperm  passes  in  by  this  tube. 

The  second  chapter  of  this  very  elaborate  paper  (which  extends 
altogether  over  144  pages,  and  is  illustrated  by  ten  plates)  deals 
with  the  Terebellidfe,  and  the  parts  discussed  are  arranged  in 
sections  as  follows: — (1)  The  animal;  body;  organs  of  nutrition; 
(2)  organs  of  excretion  and  reproduction,  organ  of  Bojauus,  seg- 
mental organs,  ovary  and  testis.  The  third  chapter  deals  with 
the  Opheliada?,  in  which  a  few  remarks  are  made  on  the  history 
of  their  development.  The  fourth  chapter  deals  with  the  Chteto- 
pterini ;  the  next  with  the  SerpulidaB,  of  which  Sabella  arenilega 
and  Myxicola  modesta  were  chiefly  studied.  The  sixth  chapter, 
dedicated  to  the  Cljmenidae,  is  especially  occupied  with  Clymenia 
zostericola,  which  ajjpears  to  be  abundant  at  Koscoff.  The  Pecti- 
naridfe  occupy  the  seventh  chapter ;  the  Hermellidga  the  eighth. 
In  the  introduction  to  this  the  author  repeats  that,  for  the  purpose 
of  distinctly  seeing  the  segmental  organs,  it  is  necessary  to  have 
living  specimens.  The  second  part  of  the  essay  deals  with  the  Errant 
Annelids,  of  which  four  families  only  were  studied.  The  repre- 
sentatives of  these  were  Hermione,  Sthcnelais,  Cirratulus,  Nereis,  and 
Marphysa. 

The  author  would  seem  to  be  much  impressed  by  the  way  in 
which  the  organs  examined  differ  in  different  species. 

Copulatory  Organs  of  Microphthalmus.* — Dr.  Bobretzky,  in 
describing  the  se  organs,  states  that  M.  fragilis  and  M.  similis,  the  two 
species  found  at  Sebastopol,  are  both  hermaphrodite,  and  that  the 
male  sexual  products  are  exclusively  developed  in  the  segments  of 
the  anterior,  and  the  female  in  those  of  the  posterior  half  of  the  body. 
These  annelids  are  also  characterized  by  the  fact  that  their  coelom  is 
more  or  less  completely  filled  up  by  connective  tissue ;  when  we  find 
an  animal  with  the  sexual  j)roducts  matured,  we  may  see  two  male 
copulatory  organs,  which  are  attached  to  the  body  at  the  point  of 
union  of  the  second  and  third  setigerous  segments ;  each  consists  of 
two  fleshy  lips,  with  a  median  penial  papilla,  at  the  centre  of  which 
there  is  placed  the  orifice  of  the  vas  deferens.  This  duct  has  a 
ciliated  internal  orifice  ;  the  ripe  zoosperms  chiefly  become  collected 
together  at  the  sides  of  the  enteric  canal.     In  each  segment  of  the 

*  'Zool.  Anzeig.,'  iii.  (1880)  p.  139. 


INVEETEBRATA,   CRYPTOGAMIA,   MICROSCOPY,    ETC.  951 

female  or  hinder  portion  of  the  body  there  are  two  somewhat  spacious 
sacs,  often  found  filled  with  zoosperms  ;  each  of  these  communicates 
with  a  narrow  tubular  canal,  which  opens  into  the  ccelom  by  a  ciliated 
infundibulum.  There  is  also  another  opening  connected  with  these 
sacs,  the  function  of  which  is  evidently  that  of  a  receptaculum  seminis  ; 
these  open  to  the  exterior  at  the  base  of  their  proper  paradopodia. 
It  is  further  to  be  noted  that  these  sacs  resemble  in  their  structure 
and  arrangement  segmental  organs,  and  this  is  the  more  obvious  in 
young  specimens  in  which  the  sexual  products  are  still  undeveloped. 
The  author  is  unable  to  decide  definitely  whether  the  male  copulatory 
organs  are  also  to  be  regarded  as  modified  segmental  organs. 

Development  and  Classification  of  the  Echiurida.* — Dr.Hatschek 
has  been  fortunate  enough  to  find  a  series  of  an  Echiurid  larva,  of 
which  he  gives  an  account.  They  were  distinguished  from  the 
species  examined  by  Salensky  not  only  by  the  fact  that  they  were 
considerably  larger  and  exhibited  a  somewhat  more  complex  develop- 
ment of  the  organs,  but  also  by  the  striking  fact  that  they  had  not 
one  only,  but  two  circlets  of  seta?  at  their  hinder  ends. 

The  series  exhibited  a  very  marked  increase  in  size,  the  specimens 
being  all  within  a  month's  development. 

The  troclioplwre-stage  includes  all  the  phases  of  the  unsegmented 
animal.  In  this  it  is  possible  to  detect  all  the  parts  which  were 
seen  in  the  same  stage  in  Poli/gordius ;  there  is  no  distinction 
externally  between  the  head  and  trunk,  and  the  latter  is,  at  this 
period,  very  inconsiderable.  In  the  cephalic  region  there  is  a 
double-rowed  pre-oral,  and  a  single-rowed  post-oral  ciliary  circlet, 
while  between  them  tbere  is  the  adoral  ciliated  zone ;  in  addition  to 
this  there  is  a  ventral  baud  between  the  mouth  and  anus.  This 
region,  later  on,  becomes  deepened  into  the  ventral  (neural)  groove. 
At  the  interior  pole  of  the  body  there  is  a  transversely  elongated 
frontal  plate,  which  is  formed  by  a  thickening  of  the  ectoderm,  and 
is  likewise  ciliated. 

The  limits  of  the  cells  of  the  ectoderm  can  only  be  distinguished 
in  some  parts,  and  in  the  rest  they  have  to  be  made  out  by  the 
arrangement  of  the  nuclei.  The  mesodermal  structures  are  thus 
arranged.  In  the  trunk,  and  lying  close  to  the  ectoderm,  there  are 
very  short  mesodermal  bands  ;  these  commence  by  two  large  oval 
cells  placed  just  in  front  of  the  anus,  and  touching  one  another  in  the 
middle  line ;  thoy  are  easily  distinguished  by  their  cleavagc-sphere- 
like  appearance.  The  few  other  cells  of  which  the  bunds  are  made 
up  are  dillcrcnt  in  character,  and  are  only  arranged  in  double  rows 
quite  anteriorly. 

The  muscles  iu  the  .cephalic  region  are  altogether  similar  to  those 
seen  in  Puh/ijordius,  and  in  addition  to  these  we  find  on  the  wbole  of 
the  inner  surface  of  the  body  -  wall  a  system  of  extrtmely  fine 
muscular  filaments,  which  are  closely  attached  to  the  ectoderm,  and 
are  arrangcid  partly  in  circular  fashion  and  partly  irr(>gulurly  ;  these 
are  shown,  later  on,  to  bo  very  characteristic  of  tlio  Echiurid  larva. 

*  'Clans'  Arbeitcn,'  iii.  (1880)  p.  45. 


952  KECOED    OF    CURRENT    RESEARCHES   RELATING    TO 

By  the  aid  of  high  magnification,  it  is  possible  to  see  in  the  hinder 
portion  of  the  cephalic  region  a  very  delicate  longitudinal  canal — 
the  head-kidney ;  this  runs  for  the  greater  part  of  its  course  parallel 
to  the  ventral  longitudinal  muscle,  and  opens  ventrally  at  the  anterior 
end  of  the  mesodermal  band,  where  its  lumen  is  continuous  with  a  fine 
pore  in  the  ectoderm.  Anteriorly,  this  excretory  organ  terminates  in 
a  small  solid  swelling,  which  is  distinguishable  by  its  clearer 
appearance  from  the  dark  granular  protoplasm  of  the  walls  of  the 
canal.  The  termination  would  appear  to  be  formed  by  a  single  cell, 
and  the  rest  of  the  canal  by  a  very  small  number  of  cells. 

The  point  to  be  noted  in  the  older  examples  of  the  same  stage  is 
chiefly  the  great  increase  in  the  size  of  the  trunk ;  this  affects 
chiefly  the  mesodermal  bands  which,  growing  rapidly,  get  their  cells 
arranged  in  two,  then  in  several  rows,  and,  in  time,  in  two  layers. 
Of  other  characters,  the  most  important  are  the  appearance  of  a 
pre-anal  circlet  of  cilia,  not  hitherto  distinctly  seen  in  the  larva  either 
of  Mollusca  or  Rotatoria ;  the  pre-oral  circlet  gradually  becomes 
reduced  to  one  row ;  the  cells  which  form  the  inner  layer  of  the 
integument  become  considerably  modified  ;  at  first  connected  with 
one  another  by  numerous  in*ocesses,  they  become  in  time  converted 
into  a  membrane,  which  forms  an  internal  sac ;  a  secondary  branch  is 
developed  on  the  kidney,  and  in  time  the  primary  one  is  atrophied. 

The  characters  of  the  second  period  are  shortly  summed  up  in 
saying  that  the  increase  in  size  is  still  chiefly  seen  in  the  region  of 
the  trunk ;  the  mesodermal  bands  become  further  developed  in  the 
characteristic  Annelid  mode ;  starting  from  before  backwards  they 
give  rise  to  the  primary  segments.  In  these  there  appear  cavities 
which  are  due  to  the  separation  of  the  entero-muscular  from  the 
dermo-muscular  layer.  It  is  at  this  period  that  the  oesophageal 
commissures  and  the  lateral  ganglia  of  the  ventral  cord  begin  to  be 
developed,  and  that  we  see  the  first  appearance  of  the  ventral 
setigerous  sacs ;  these  are  placed  in  the  first  trunk-segment,  and  at 
the  sides  of  the  ventral  longitudinal  muscles. 

In  the  third  period  the  process  of  segmentation  comes  to  an  end, 
and  the  separate  segments  all  take  very  much  the  same  appearance. 
Metamerism  is  very  clearly  shown,  internally,  by  the  appearance  of 
segmental  ciliary  circlets,  and  (later  on)  by  the  peculiar  arrange- 
ment of  the  pigment.  At  the  same  time  we  find  that  the  internal 
dissepiments,  which  primitively  divided  the  secondary  coelom  into 
segmental  cavities,  are  converted  into  filaments,  and  are  gradually 
replaced  by  a  tissue  of  ramifying  cells  which  extend  between  the 
dermo-muscular  and  the  entero-muscular  plates.  Nor  can  any  very 
distinct  indications  of  segmentation  be  said  to  be  afforded  by  the 
ventral  ganglionic  cord. 

Turning  to  the  development  of  the  setfe,  we  find  that  their  sacs 
have  been  growing  inwards  towards  the  coelom,  and  transverse 
growths  give  indications  of  the  muscles  of  the  setee ;  internally  a 
small  cavity  is  formed,  and  at  its  base  there  appears  a  small,  highly 
refractive  corpuscle,  which  is  the  tip  of  the  seta.  This  grows  broader, 
and  elongates  ;  its  cavity  is  still  hollow,  its  chitiuous  walls  show  signs 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  953 

of  a  longitudinal  striation,  and  it  is  soon  possible  to  detect  a  striation 
of  its  epithelial  cells.  The  terminal  kidneys  are  also  appearing  ; 
these  arc  not  developed,  as  has  been  often  supposed,  from  the  rectum, 
but  in  a  similar  fashion  to  the  other  segmental  organs,  and,  as  they 
belong  to  the  terminal  segment,  their  mode  of  development  has  an 
important  bearing  on  the  theory  of  metamerism.  Other  points  must 
be  passed  over  to  bring  us  to  the  next  stage  in  which  the  larval 
characters  begin  to  lose  their  importance,  and  the  creature  commences 
to  take  on  the  more  definite  characters  of  the  Echiurus.  As  these 
processes  are  being  completed  the  ciliary  circlets  get  lost,  while 
blood-vessels  and  dermal  papillte  begin  to  appear.  In  the  last  larval 
stage  we  have  distinct,  though  young,  Echiuri. 

Theoretical  Considerations. — The  author  is  of  opinion  that  the 
history  of  develoijment,  as  he  has  observed  it,  is  conclusive  as  to  the 
Annelidan  affinities  of  Echiurus  ;  and,  as  this  genus  has  very  distinct 
relations  to  the  other  chfctigerous  Gephyrea,  Thalassema  and  Bonellia, 
he  believes  himself  justified  in  extending  his  generalizations  to  the 
whole  of  the  Echiurida.  Every  point  of  importance  in  development 
is  Annelidan,  but  we  have  farther  to  recognize  that,  owing  to 
adaptation  to  special  modes  of  life,  the  Echiurida  are  modified  forms. 
The  next  question  is,  of  course,  are  their  relations  to  the  Archi- 
annelides  closer  than  they  are  to  higher  forms  ?  and  here  their  com- 
plicated organization  and  the  jDresence  of  the  characteristic  setai 
enable  us  to  answer  it  in  favour  of  their  nearer  relationship  being  to 
the  Chastopoda.  Further  consideration  leads  us  to  see  that  by  the 
presence  of  a  proboscis,  the  absence  of  distinct  dissepiments,  tho 
reduction  of  the  setoe  and  of  the  segmental  organs,  together  with  such 
important  j)oints  as  the  extension  of  the  post-oral  region  and  the 
characters  of  the  terminal  segments  in  which  there  is  an  organ 
homodynamous  with  a  segmental  organ,  the  Echiurida  have  undergone 
a  wide  divergence  from  the  primitive  type. 

As  to  their  relations  to  the  non-setigerous  Gephyrea  (Sipunculids, 
&c.),  the  author  is  not  completely  satisfied,  and  waits  for  embryological 
investigations  to  say  whether  some  of  their  characteristics  are  due  to 
genetic  relations. 

The  Annelidcs  may  now  bo  thus  arranged : — 

1st  Class.  Archiannclides  (Polygordiua). 

2nd  Class.  Chaitopodcs. 
1st  Order.  Saccocirrida3. 
2ud     J,        Polycha;tiT!. 
3rd.     „        Echiuridic. 
4th.     „       Oligochicta;. 

3rd  Class.  Ilirudinea. 

Api)endix  (1th  Class).  Sipuneulacea. 

As  to  their  bearing  en  the  Trocliophoro-thoory,  tho  author  is  of 
opinion  that  the  i)resent  results  bear  out  fully  the  doctrines  on  which 
he  has  previously  insisted ;  while  as  to  the  theory  of  segmentation, 
he  points  out  that  in  tho  IVIullusca  there  is  a  similar  distinction 
between  head  and  trunk,  but  that  no  mutameric  difiercntiation  is  to 
be  made  out  in  the  latter.     In  the  hnver  Bilateria  the  chief  orfjians  of 


954  RECORD    OF   CURRENT    RESEARCHES   RELATING    TO 

animal  life  are  confined  to  the  anterior  portion  of  tlie  body,  while  the 
hinder  part  contains  the  generative  organs.  But,  nevertheless,  it  is 
only  gradually  that  the  head  takes  on  the  higher  sensory  functions 
and  becomes  sterile.  At  first  it  is  the  head  which  is  the  largest  part 
of  the  body  ;  in  the  trunk,  differentiation  commences  in  the  anterior 
portion,  and  growth  is  terminal.  This  is  the  typical  mode  of  growth 
which  leads  in  time  to  the  typical  metameric  animal. 

Excretory  Organs  in  the  Trematoda  and  Cestoida.* — M.  Frai- 
pont  has  a  fuller  paper  on  this  subject,!  which  is  illustrated  by  two 
plates. 

In  dealing  with  the  morphology  of  the  excretory  system  in 
the  Vermes,  he  points  out  that,  on  a  comparative  examination,  there 
are  two  types  of  renal  organs.  In  the  Turbellaria,  Nemertinea, 
Cestoida,  Trematoda,  and  Eotifera,  there  is  a  system  of  canals,  with 
walls,  which  are  probably  glandular,  and  which  ojien  into  the  coelom 
by  a  number  of  ciliated  infuudibnla,  and  are  connected  with  the  outer 
world  by  a  single  and  median,  or  by  two  lateral  vesicles.  On  the 
other  hand,  in  the  Anuulata  (Hirudinea,  Oligochfeta,  Chfetopoda)  there 
are  true  segmental  organs  (uephridia — Laukester)  which  are  always 
multiple  and  paired.  In  the  Gephyrea  both  sets  of  organs  appear  to 
be  present. 

Coming  to  closer  details,  it  is  possible  to  detect  in  the  Trema- 
toda : — 

(1)  A  terminal  vesicle,  posterior  in  position ;  or  two  vesicles, 
ventral  and  anterior. 

(2)  Into  this  there  open  by  two  trunks  a  system  of  large  canals. 

(3)  These  canals  communicate  with  lymphatic  spaces  by  ciliated 
infundibula. 

(4)  From  these,  canaliculi  pass  into  the  larger  canals. 
Practically  similar  arrangements  are  to  be  seen  in  the  Cestoida ; 

but  it  is  to  be  noted  that  in  some,  at  any  rate,  of  the  forms  which 
exhibit  a  segmentation  there  are  a  number  of  pores  communicating 
with  the  exterior ;  and  this  is  of  interest  as  pointing  to  the  mode  by 
which  in  the  Annulata  a  number  of  organs  may  have  become  deve- 
loped. 

In  the  Dendrocoelous  Turbellarians,  Hallez  has  denied  the  presence 
of  an  excretory  apparatus,  but  the  observations  of  Schmidt,  Schultze, 
and  Kennel  would  appear  to  make  its  presence  almost  certain.  Not- 
withstanding contradictory  statements,  an  arrangement  is  also  to  be 
found  in  the  Nemertinea  (especially  Malacohdella)  which  is  exactly 
formed  on  the  same  type  as  in  the  Ehabdocoela. 

In  the  Rotifera  we  again  find  an  organ  formed  of  three  constituent 
parts :  (1)  a  terminal  vesicle,  single  or  double,  and  ordinarily  placed 
at  the  hinder  end  of  the  body,  (2)  two  large  lateral  trunks,  with  a 
glandular  wall,  and  (3)  small  canaliculi  which  open  into  the  general 
cavity  of  the  body  by  one  or  more  ciliated  infundibula.  This  general 
concordance  in  structure  is  in  striking  agreement  with  the  well- 
known  views  of  Professor  Gegenbaur. 

*  '  Arcli.  de  Biol.,'  i.  (1880)  p.  415.  +  See  this  Journal,  ante,  p.  802. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  955 

Can  we  fiutl  in  the  anal  vesicles  of  the  Gephyrea  a  resemblance  to 
the  excretory  organs  of  the  Rotifera  ?  The  investigations  of  Lacaze- 
Duthiers  on  Bonellia  viridis  have  shown  that  there  are  two  large 
contractile  vesicles  opening  into  the  cloaca  ;  into  these  vesicles  open 
tufts  of  ramified  tubes  which  open  by  their  end  into  the  coelom  by 
ciliated  iufundibula ;  the  author  remarks  that  in  Echiurus  this 
arrangement  is  less  well  developed,*  and  that  in  Sipunculns  it  is 
reduced  to  the  rudiments  of  the  vesicles.  On  the  other  hand,  Sipun- 
cnliis  has  a  pair  of  true  segmental  organs,  while  Bonellia  has  none  at 
all.  In  Thalassema  and  the  Echiurida  there  are  two  or  three  pairs  of 
segmental  organs. 

In  the  Hirudinea  the  primitive  excretory  apparatus  seems,  at  least 
during  development,  to  make  a  last  appearance,  while  it  completely 
disappears  in  the  Annelidcs.  Are  the  permanent  renal  organs  of 
these  Annulata  the  homologues  of  the  apparatus  found  in  the  more 
lowly  worms?  This  does  not  seem  to  be  yet  certainly  established, 
for  we  have  (1)  the  presence  of  both  sets  of  organs  in  some  adult 
Gephyrea,  and  (2)  in  the  Hirudinea  the  two  sets,  one  of  which  dis- 
appears very  early,  appear  to  have  an  independent  origin. 

Tlic  author  is  not  inclined  to  accept  Professor  Haeckel's  division  of 
the  Vermes  into  Ccelomati  and  Acoelomati ;  as  to  the  latter,  he  points 
out  that  there  are  spaces  in  tlie  connective  tissue  of  the  Trematoda, 
and  that  into  these  the  ciliated  infundibula  open ;  these  lacunae  may 
further  vary  greatly  in  extent ;  this  is  true  of  the  terrestrial  Planaria, 
where  Moscley  has  discovered  longitudinal  s^^aces  on  either  side  of 
the  body,  and  of  the  Nemertiuea,  where  a  ccelomatic  space  has  been 
observed  by  Macintosh  and  Hubrecht  to  surround  the  digestive 
tract. 

In  a  note  presented  to  the  Academy  of  Brussels,!  M.  Fraipont 
states  that  he  has  been  able  to  extend  his  observations  to  Distomum 
appendiculatum  (which  lives  in  the  intestine  of  Gadus  morrhua),  and 
finds  it  to  be  provided  with  ciliated  infundibula,  exactly  comparable 
to  those  of  D.  S(iunmida.  D.  divtn/cns  has,  it  is  interesting  to  note. 
two  infundibula  terminating  each  canaliculus,  and  that  in  the  place 
of  one.  A  young  living  Tienia  echinococcus  has,  in  addition  to  the 
four  longitudinal  canals,  a  system  of  fine  canaliculi,  a  certain  number 
of  whicl)  terminate  by  small  ciliated  infundibula,  similar  to  those  of 
T.  serrat a  and  T.  cucumcrina.  Bothriocepludus  infundihuUformis  (from 
the  pyloric  ai)pendages  and  intestine  of  Trutta  trutta)  has  a  very 
complicated  system  of  canals.  Tricuspidaria  nodulosa  (from  the 
intestine  of  Esox  lnrian)  has  a  plexus  of  very  fine  canaliculi,  from 
which  there  arise  small  branches  which  are  j)rovided  at  their  free  end 
with  a  ciliated  infundibuluni. 

Ciliated  Embryo  of  Bilharzia.:}: — The  ovum  of  this  little-studied 
entozonn  presents,  according  to  ]M.  J.  Chatin,  a  regularly  oval  shape, 
and  a  smooth  external  contour,  and  has  a  conical  prominence  at  one  of 
its  poles.    Segmentation  is  rapid,  and  results  ultimately  in  the  forma- 

*  Sec  t1lis  Journal,  .ni/r.  p.   \'M. 

t  •  Hull.  A.ad.  K.  Sci.  IJfl- ,'  xlix.  (1880)  p.  lOG. 

i  'CoinptcH  Ucn.lu.s,'  xci.  (1880)  p.  554. 


956  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

tion  of  an  embryo  covered  with  a  well-ciliated  cuticle.  A  kind  of 
proboscis  indicates  the  future  cephalic  region.  No  differentiation 
takes  place  internally,  as  a  rule,  until  the  extrusion  of  the  egg. 
After  this  has  occurred,  a  cascal  depression  commences  to  form  below 
the  proboscis,  and  extends  vertically  into  the  body.  It  grows  con- 
siderably, and  throws  out  a  number  of  secondary  diverticula,  which 
form  an  elaborate  network,  of  vascular  appearance,  at  different  parts 
of  the  body,  especially  in  the  tegumentary  layer.  At  the  same  time 
appear  in  the  posterior  region  sumo  usually  spheroidal  bodies,  which 
increase  in  number  and  bulk,  and  contain  nitrogenous,  glycogenous, 
and  fatty  materials.  They  are  j)robably  gemmaB  formed  within  the 
embryo ;  for  when  they  are  fully  formed,  it  becomes  disintegrated 
and  sets  them  free,  when  they  move  about  with  rapid  contractions  in 
the  surrounding  medium. 

The  nature  of  the  ovum,  as  here  set  forth,  shows  this  animal  to 
rank,  at  this  stage,  above  all  the  other  members  of  its  class ;  for  the 
Cfeca  which  it  possesses  represent  the  beginning  of  a  digestive  appara- 
tus, and  the  vascular  tree  represents  an  excretory  organ,  while  the 
contractile  gemmae  are  an  entirely  new  factor  in  the  anatomy  of  the 
group. 

New  Type  of  the  Cestodes.* — M.  Mouiez,  impressed  with  the 
necessity  of  a  comparative  study,  has  of  late  largely  devoted  himself 
to  these  forms,  and  he  has  been  rewarded  by  the  discovery  of  a  new 
type,  to  which  he  gives  the  generic  name  of  Leuckartia.  It  is  an 
unarmed  Bothriocephalid,  with  both  ventral  and  lateral  genital  organs. 
It  was  found  in  the  pyloric  appendages  of  a  salmon,  from  an  unknown 
locality. 

Among  the  interesting  points  discussed,  special  attention  is  due  to 
the  account  of  the  nervous  system,  which,  as  is  well  known,  is  so 
difficult  to  make  out  distinctly  in  these  worms.  Here  it  is  easily 
seen.  It  does  not,  however,  seem  to  persist  for  a  long  period,  but  to 
early  undergo  a  kind  of  fatty  degeneration ;  so  that  it  is,  therefore, 
best  studied  in  young  joints.  The  author  believes  that  Sommer  and 
Landois  have  mistaken  for  nerves  the  outer  of  the  two  blood-vessels 
which  they  describe.  In  Bothriocephalus  latus  (old  joints)  the  nervous 
cords  are,  owing  to  the  great  development  of  the  spermatozoa,  pushed 
to  the  ventral  surface,  and  it  is  very  much  this  position  that  the 
German  helminthologists  give  to  their  outer  vessel. 

With  regard  to  the  systematic  position  of  Leuckartia,  the  author 
points  out  that,  with  the  exception  of  TrioenopJiorus,  the  Bothrio- 
cephalida  have  the  genital  orifices  ventral  in  position,  and  have  two 
suckers,  while  the  TjeniadsB  have  the  genital  orifices  lateral  and  have 
four  suckers.  The  new  genus  belongs  to  the  former  group,  for  B. 
proboscideus  (as  figui-ed  by  Blanchard)  has  both  lateral  and  ventral 
genital  organs. 

New  Cestodes. t — M.  Moniez  describes  a  new  species  of  Tcenia, 
from  the  intestines  of  the  wild  rabbits  at  Wimereux,  under  the  name 
of  T.  wimerosa.     It  is  about  1  cm.  long  by  1^  mm.  broad.     The  head 
*  '  Bull.  Sci.  De'p.  du  Nord,'  ill.  (1880)  p.  G7.  t  Ibiil-,  P-  240. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  057 

is  large,  with  well-marked  suckers,  but  no  Looks  or  neck.  The  lower 
edge  of  the  segments  is  very  distinct,  rounded,  and  bears  a  row  of 
filaments  resembling  those  of  the  suckers  of  Ligula.  The  genital 
apparatus  is  single,  and  occurs  on  the  same  side  in  all  segments,  the 
female  opening  on  the  inferior  edge,  the  very  prominent  penis  in  the 
middle  of  each.  The  penial  sheath  early  occupies  most  of  the  seg- 
ment, but  is  iiltimately  absorbed,  owing  to  the  development  of  the 
ova.     The  ova  resemble  those  of  the  Tcenice  inarmatK. 

In  considering  the  development  of  the  Cestodes,  M.  Moniez  points 
out  that  the  imperfect  segmentation  of  the  ovum,  as  shown  by  Teenia 
serrata  and  expansa,  is  by  no  means  the  rule  in  this  group.  And  in 
these  cases  the  extruded  cells  do  not  aid  in  the  formation  of  the  cells 
of  the  blastoderm,  but  they  are  the  homologues  of  the  polar  corpus- 
cules,  and  only  occur  when  these  are  wanting,  and  vice  versa.  The 
true  relations  of  the  extruded  cell  are  seen  clearly  in  a  new  species  of 
Cestode,  found  at  Wimereux,  in  Squatina  angelus.  Here  the  original 
egg-cell,  after  dividing  into  two,  becomes  distended  with  liquid,  and 
ascends  to  the  surface  of  the  yolk,  and  is  ixsually  destroyed  shortly. 
On  the  other  hand,  the  primary  cell  is  detached  in  the  form  of  an 
ordinary  polar  vesicle  in  species  such  as  T.  anatina,  &c.,  in  which  the 
segmentation  appears  to  be  regular ;  or  else  it  persists,  and  increases 
greatly  in  size  (in  T.  serjientulus  and  others),  in  which  case,  the  blasto- 
dermic cells  surround  it,  and  may  even  conceal  it,  after  giving  the 
embryo  the  appearance  of  being  hollow.  In  a  Botlirioceplialas  inhabit- 
ing the  salmon,  these  processes  are  exactly  like  those  of  Liyula,  except 
that  tlie  embryo  is  developed  within  the  parent,  and  that  the  amnion, 
corresponding  to  the  embryophore,  is  granular,  and  shows  no  analogy 
with  the  corresponding  membrane  in  Ligula.  The  embryo  is  seen  in 
Teenia  serpentulus,  and  less  distinctly  in  T.  cuciimerina,  gradually 
to  become  hollow.  Two  muscles,  strongly  refractive  in  appearance, 
arc  especially  noticeable,  passing  backwards  from  the  cephalic  bulb, 
to  become  attached  at  the  posterior  end  of  the  cavity  thus  formed. 

The  segmental  organs  of  the  Cestoidea  are  not  the  organs  described 
by  Fraipont  as  such,  but,  as  is  the  most  clearly  seen  in  Leuckartia, 
consist  of  the  so-called  vagina,  which  opens  at  one  end  into  the  uterus, 
and  at  tlie  other  into  a  wider  chamber  connected  with  the  ova.  This 
chamber  lias  proper  muscles,  is  attached  on  all  sides  to  the  surround- 
ing tissues,  and  the  cells  which  line  it  contain  a  coloured  material  ; 
the  tube  leading  to  it  is  ciliated  throughout.  It  thus  fulfils  all  the 
requirements  of  a  typical  segmental  organ ;  and  it  is  known  to  exist 
in  tliis  form  in  the  higher  Tani(i\ 

Solenophorus  megacephalus.* — -M.  Moniez  in  this  note  criticizes 
the  account  given  by  M.  ruirier.f  The  later  observer  has  only 
been  able  to  detect  two  (one  on  either  side)  in  place  of  six  longi- 
tudinal vessels.  Without  dealing  with  any  points  in  discussion 
between  these  two  naturalists,  it  is  of  importance  to  direct  attention 
to  the  explanation  which  ]\r.  ]\[oniez  gives  as  to  the  very  ditfurent 
accounts   of  various  observers.     As  in  all  the  lower  animals,  thero 

♦  '  Hull.  Sci.  Dcp.  (In  Nnrd,'  iii.  (ISSO)  p.  113. 
t  Sec  this  .Iduniiil,  ii.  (187'.t)  p.  2M. 
VOL.    111.  3    S 


958  RECORD    OF   CURRENT   RESEARCHES    RELATING    TO 

appear  to  be  all  kinds  of  grades  between  distinct  vessels  with  complete 
walls,  and  those  whicb  may  almost  be  regarded  as  lacunae.  More- 
over, there  are  examples  of  central  vessels  which  give  rise  to  largely 
anastomosing  peripheral  branches ;  and  these  (as  in  Leuckartia)  may 
even  penetrate  into  the  meshes  of  the  fundamental  tissue.  Injections 
might,  of  course,  give  rise  to  the  appearance  of  vessels  in  cases  such 
as  these.  The  author  further  directs  attention  to  the  great  develop- 
ment of  the  marginal  fold  of  each  joint  in  Solenophorus. 

Histolog'y  of  the  Tetrarhynchi* — Herr  Laczko  says  of  the 
"  knobs  "  of  the  proboscis  of  these  forms  that  they  are  provided  with 
two  muscular  layers.  One  is  very  thick  on  its  outer  surface,  and 
forms  a  layer  of  longitudinal  fibres,  arranged  in  three  groups.  The 
other,  external  to  this,  consists  of  a  double  layer  of  diagonal  fibres. 
In  addition  to  these,  there  is  also  a  circular  layer,  the  fibres  of  which 
are  thick.  The  retractor  proboscidis  arises  independently  from  the 
most  posterior  portion  of  the  wall  of  the  knob,  and  gradually  decreases 
in  width  as  it  passes  forwards.  The  nervous  system  appears  to  be 
exceedingly  well-developed.  On  both  the  ventral  and  the  dorsal  sides 
there  is  a  well-developed  layer  of  ganglionic  cells.  These  are  uni- 
polar, of  considerable  size,  and  provided  with  a  distinct  nucleus. 
The  processes  which  arise  from  them,  and  which  may  be  twice  or 
thrice  as  long  as  the  cell,  have  their  long  axis  in  a  line  with  that  of 
the  muscular  fibres.  It  is  clear,  therefore,  that  we  have  to  do  with 
a  cephalic  ganglion  formed  of  typical,  large,  unipolar  ganglion  cells, 
which  give  ofi'  two  columns  of  ganglionic  substance  to  the  knobs  of 
the  proboscis,  and  also  send  branches  to  the  suckers. 

Echinodermata. 

Viviparous  Chirodota.f — Dr.  Hubert  Ludwig  directs  attention  to 
the  rediscovery  of  Oersted's  Synaptula  vivipara  (the  Chirodota  rotifera 
of  Pourtales).  Dr.  Ludwig's  example  was  obtained  by  Professor  E.  van 
Beneden  from  the  Brazilian  seas.  In  the  body-cavity,  an  1  quite  free, 
he  found  sixteen  young,  all  considerably  developed.  No  indications 
could  be  made  out  of  the  way  by  which  they  would  pass  to  the  ex- 
terior. The  specimens  were  so  well  preserved  that  the  author  has 
been  able  to  make  a  complete  anatomical  investigation,  which  he 
promises  to  publish  shortly.  The  attention  of  American  naturalists 
to  the  subject  will  probably  lead  to  important  results. 

Observations  on  the  Temnopleuridae.  |  —  The  greater  part  of 
Professor  Bell's  paper  on  these  regular  Echinoida  is  occujjied  with  an 
account  of  the  measurements  of  the  more  important  parts  of  the  tests 
of  these  creatures  ;  the  diameter  being  given  in  absolute  measurements, 
the  percentage  values  of  the  measurements  of  the  height,  the  abactinal 
area,  the  anal  area,  and  the  actinostome  are  given  in  percentages, 
"  Two  recommendations,"  the  author  says,  "  present  themselves  for 
undertaking  this  exceedingly  laborious  task :  the  changes  which  occur 
during  growth  are  at  once  seen  ;  and  secondly,  an  aid  is  given  to  that 

*  'Zool.  Anzeig,'  iii.  (1880)  p.  427.  t  Ibid.,  p.  492. 

X  'Proc.  Zool.  Soc.  Lond,,'  1880,  p.  422.     (1  plate.) 


INVERTEBEATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  959 

not  small  group  of  naturalists  who  have  not  under  their  hands  so 
large  a  series  of  forms  as  is  fortunately  to  be  found  in  our  own 
national  collection.  Differences  in  proportion  will  not  now  form  the 
chief  ground  on  wliich  new  species  are  established ;  and  the  value  of 
the  British  Museum  series  will  be  hereby  extended  to  those  naturalists 
who,  for  want  of  such,  are  naturally  enough  led  to  regard  their  single 
immature  specimen  as  the  rejiresentative  of  a  new  species." 

In  dealing  with  the  genus  Ambh/jmeustes  Professor  Bell  points  out 
that,  in  the  case  of  A.  griseus  and  A.  formosus,  it  is  possible  to  detect 
two  very  distinct  series  for  each  species  ;  taking  the  former,  we  find 
that  there  is  one  series  with  a  small  actinostome,  a  small  abactinal 
area,  and  a  rather  wide  poriferous  zone ;  the  other  has  the  actinal  and 
abactinal  areas  very  much  larger,  and  the  poriferous  zone  somewhat 
narrower ;  these  characters  are  shown  by  the  table  of  measurements  ; 
with  them,  however,  there  are  associated  two  others,  "  those  with  the 
small  actinostome  have  much  larger  genital  pores  and  the  madreporic 
plate  is  much  more  prominent,"  In  dealing  with  A.  formosus  the 
author  enters  into  greater  details  as  to  the  sizes  of  the  genital  pores, 
and  illustrates  his  results  by  showing,  by  the  aid  of  four  entomological 
pins,  of  various  calibres,  how  these  small  orifices  may  vary  in  size. 
He  propoimds  the  possibility  of  the  two  series  being,  in  each  case, 
diifcrent  sex-form.s  of  the  species,  and  looks  to  those  naturalists  who 
can  get  fresh  specimens,  for  a  definite  resolution  of  the  question.  In 
dealing  with  Salmacis  globator  he  points  out  that  two  very  distinct 
forms  appear  to  have  had  this  name  given  to  them,  but  he  refrains 
from  naming  at  the  present  either  one  or  the  other,  and  contents 
himself  with  giving  a  descrii^tion  of  the  two,  and  figures  of  them  both. 
He  hopes  that  Professor  Alex.  Agassiz  will  be  able  to  set  this  matter 
right,  as  he  and  his  father  arc  the  only  two  naturalists  who  have  given 
original  descriptions  of  the  sjiecies. 

With  regard  to  changes  during  growth,  one  or  two  examples  will 
show  how  marked  this  may  be  ;  if  we  take  Temnopleurus  UardwicJcii  we 
find  that  a  specimen  7  mm.  in  diameter  has  an  anal  area  14 '28  per 
cent,  wide  and  an  actinostome  42*8  per  cent,  wide,  while  one  43  mm. 
in  diameter  has  the  same  parts  9  "02  per  cent,  and  26  "7  wide  ;  while 
Salmacis  sulcata  has,  with  14  mm.  for  diameter,  an  actinostome  of  a 
width  42 '8  per  cent.,  and  when  the  diameter  is  59  mm.  the  percentage 
value  of  the  widtli  of  the  actinostome  is  only  26  •  6. 

Abnormal  Echinids.* — Professor  Jeffrey  Bell  and  Mr.  Charles 
Stewart  direct  attention  to  two  cases  of  abnormalities  in  these  forms  ; 
tliey  arc  both  exhibited  by  spoi  imens  belonging  to  the  Teranopleurid 
genus  Amhlypneustcs,  and  are,  wlien  taken  together,  interesting  as 
pointing  in  opposite  directions ;  so  far  that  is,  that  one  describes  a 
quadriradiate  and  the  other  a  sexradiatc  variation  from  the  ordinary 
pciitanurons  arrangement. 

Mr.  Stewart's  specimen,  wliich  was  from  his  own  cabinet,  and 
belonged  to  A.  griseus,  is  remarkable  for  having  "a  crost-liko  elevation 
of  what  ai>pears  to  be  ono  of  the  ambulacra  "  ;  this  crest  is  shown  to 

*  '  Jnnrn.  Linn.  Soc'  (Zool.),  xv.  (18S0)  pp.  12fi-9.     (1  plate.) 

3   S   2 


960  RECORD   OF    CURRENT   RESEARCHES   RELATING   TO 

be  formed  by  two  ambulacra  wbicb  lie  side  by  side  ;  the  poriferous 
zones  which  touch  one  another  are  fused  together ;  the  other  zones 
and  the  anibiilacral  arete  are  normal  in  character.  In  this  form  the 
apical  system  was  normal. 

The  other  specimen  is  in  the  collection  of  the  British  Museum, 
and  was  one  of  tlie  examples  of  A.  fo7-mosus  which  were  brought  home 
by  the  '  Challenger.'  In  it  no  indications  of  the  fifth  segment  of  the 
corona  are  to  be  observed  except  on  the  actinal  surface,  but  there  are 
no  indications  of  the  interambulacral  plates ;  just  as  in  Echinus  melo, 
the  only  other  recent  species  in  which  a  similar  abnormality  has 
been  noted  (Philipiji),  it  is  the  left  anterior  area  which  has  suffered 
the  injury  ;  the  abactinal  regions,  in  these  two  specimens,  differ  so  far 
from  one  another,  that  in  Phillippi's  specimen  there  was  a  tetramerous 
arrangement,  while  in  the  British  Museum  specimen  all  the  ten  plates 
are  still  present ;  but  this  latter  differs  again  from  Mr.  Stewart's 
example  in  having  an  ocular  plate  considerably  enlarged.  Professor 
Bell  imagines  that  "  had  its  capture  been  a  little  delayed,  the  plates 
of  the  fifth  segment  or  area  might  have  been  comj^letely  forced  off." 
A  purely  tetramerous  test  has,  he  observes,  been  found  fossil  ;  this, 
described  by  H.  von  Meyer,  belonged  to  the  species  Cidarites  coronatus. 
The  author  concluded  by  insisting  (1)  on  the  fact  that  deviations 
from  the  pentamerous  type  seem,  in  the  Echinida,  to  be  due  to  abnor- 
malities, and  (2)  on  the  striking  constancy  which  is  exhibited  by  these 
forms,  as  compared  with  Asterids  or  Ophiurids. 

Remarkable  Form  of  Pedicellaria.*  —  Mr.  Sladen  gives  in  a 
tabular  form  the  "  synonymy  "  of  these  organs  : — 

O.  F.  Muller  (1778).  Valentin  (1841).  Perrier  (1869). 

P.  ghhifera  =  P.  gemmiforme  =         P.  cjemmiforme 

P.  triphylla         =         P.  opicephale  ou  huccale        =  P.  ophicephale 

P.  tridens  —         P.  tridactyle  =         P.  tridactyle 

In  SplicerecMnus  granulans  the  pedicellarife  globiferse  are  very 
much  larger  than  the  rest  and  are,  as  compared  with  the  same  organs  in 
other  Echinids,  enormous  ;  upon  their  stem  or  pedicle  there  is  situated, 
between  the  middle  portion  of  the  shaft  and  the  distal  end,  a  remark- 
able glandular  organ ;  it  is  divided  into  three  separate  sacculi,  and 
near  the  upper  portion  of  each  there  is  a  small  foramen  through 
which  a  glairy  mucus  is  extruded ;  this  extrusion  is  mostly  easily 
observed  when  a  specimen  is  placed  in  fresh  water.  Each  sacculus  is, 
on  examination,  seen  to  contain  an  "  elongate-ovate  or  sub-cordiform 
mass "  ;  when  seen  separately  this  mass  is  found  to  consist  of  a 
"  white,  spongy,  reticulated  substance  with  a  denser  central  portion 
within  and  a  number  of  moderately  large  j^ink  cells  distributed  over 
its  surface,"  external  to  the  general  mass.  Sections  are  best  made 
after  a  preliminary  decalcification  in  a  solution  of  70  per  cent,  alcohol 
with  2  per  cent,  of  hydrochloric  acid,  and  staining  in  haematoxylin. 
Transverse  sections  made  through  specimens  thus  prepared  show  the 
presence  of  (1)  the  epithelial  nucleated  cells  of  the  investing  mem- 

*  '  Ann.  and  Mag.  Nat.  Hist.,'  vi.  (1880)  p.  101. 


INVERTEBRATA,   CRYPTOGAMIA,   MICROSCOPY,   ETC.  961 

brane  ;  (2)  a  neuro-muscular  layer ;  (3)  a  tissue  with  numerous  large 
cells ;  (4)  a  layer  of  large  areolar  spaces  and  gland-cells  and  ducts  ; 
(5)  the  central  mass  composed  of  a  very  finely  reticulated  substance, 
densely  filled  up  with  mucous  matter. 

As  to  the  characters  of  the  "  head  "  of  the  P.  glohifera ;  a  longi- 
tudinal section  reveals  the  presence  of  the  following  parts : — (1)  a 
fine  investing  membrane,  composed  of  a  few  epithelial  cells.  (2)  A 
stratum  containing  a  few  nerve-cells.  (3)  The  walls  of  a  large 
saccular  body  bounded  by  a  moderately  thick  layer  of  horizontally 
disposed  muscular  fibres.  (4)  A  reticular  tissue  terminating  in  folli- 
cular gland-cells,  which  form  a  layer  internal  to  the  wall  of  the  sac, 
and  of  some  considerable  tliickncss  ;  the  glandular  sac  is  divided  into 
two  chambers.  Nerve-centres  with  fibres  for  each  valve  communicate 
with  the  strong  muscles  which  hold  together  the  valves  of  the  pedi- 
cellaria.  On  the  inner  surface  of  the  expanded  valves  there  are  to  be 
found  three  oval-shaped  cushions,  which  are  finely  papillate  and  are 
richly  provided  with  nerve-fibres. 

In  regard  to  the  suggested  functions  of  these  parts  we  find  first 
of  all  this  notable  discharge  of  mucus  ;  "  when  the  tactile  cushion  of 
the  pedicellaria  comes  into  contact  with  a  tangible  object  of  foreign 
matter,  the  valves  close  and  a  discharge  of  mucus  takes  place  "  ;  this 
mucus  surrounds  the  object  and  then  the  neighbouring  spines  gradu- 
ally disentangle  it,  and  the  currents  of  water  carry  it  off.  The  author 
has  made  observations  on  Astropeden  aurantiacus  which  strongly 
confirm  this  view. 

Mr.  Sladen  then  gives  a  short  account  of  the  structure  of  the  same 
kind  of  pedicellaria  in  Echinus  melo,  which  seems  to  resemble  the 
younger  forms  found  in  S.  granularis.  The  pedicellarife  tridentes 
appear  to  have  the  function,  already  noted  by  A.  Agassiz,  of  removing 
the  pellets  of  f.ccal  matter ;  that  of  the  P.  triphyllce  is  probably  to 
seize  smaller  particles  of  foreign  matter  which  escape  the  larger 
pedicellarife. 

New  Echinodermata.* — In  addition  to  Hymenodiscus  Agassizii, 
referred  to  in  the  next  note,  M.  E.  Perrier  jdescribes  some  very  inter- 
esting forms  obtained  during  the  dredging  operations  of  Professor 
A.  Agassiz  in  the  deeper  parts  of  the  Gulf  of  Mexico ;  among  these 
are  two  new  species  of  the  genus  Zoroaster  of  Wyvillc-Thomson 
(Z.  Slgshcii  and  Z.  Acldeyi). 

Z.  Sl'jsheii  is  at  once  distinguished  by  the  considerable  projection 
made  by  the  enormous  ossicles  of  its  disk,  wliich  is  thus  rendered 
clearly  distinct  from  the  arms  and  comparatively  voluminous.  Tho 
arms,  which  are  nearly  rigid,  are  conical,  and  their  skeletim  consists  of 
nine  regular  series  of  s(^uare  ossicles.  In  Z.  Acldvyi  the  ossicles  of 
tho  disk  are  not  salient,  the  disk  is  continuous  with  the  arms,  which 
are  about  twelve  times  as  long  as  its  radius,  so  that  the  aninuil  lias 
the  physiognomy  of  a  Chataslcr.  These  arms  are  much  more  mobile 
than  those  of  the  other  6i)ceies,  and  are  formed  of  seventeen  rows  of 
rather  small  ossicles.     In  the  two  species  before  tho  author  the  plates 

*  '  Comptea  Rendus,'  xci.  (1880)  p.  430. 


962  BECOUD    OF    CURRENT   RESEARCHES    RELATINQ    TO 

of  the  ventral  region  of  tLe  arms  are  covered  with  small  flattened 
sjjines  placed  close  together  and  intermixed  with  larger  spines,  so  as 
to  recall  to  mind  the  covering  of  the  ventral  surface  of  the  LuidicB  ; 
the  adambnlacral  plates  even  bear,  as  in  the  latter,  a  comb  of  com- 
pressed spines,  the  direction  of  which  is  perpendicular  to  that  of  the 
ambulacral  groove  and  the  innermost  of  which  is  recurved  like  a 
sabre,  as  in  the  Astropectinid^.  The  ambulacral  tentacles  are  quad- 
riserial  at  the  base  of  the  arms,  but  biserial  at  the  extremity,  which  is 
un  additional  proof  how  artificial  is  the  old  division  of  the  Asterias 
adojited  by  Mliller  and  Troschel.  These  tentacles  are  terminated  by 
a  very  small  sucking  disk  which  still  further  approximates  Zoroaster 
to  Liiidia ;  they  are  intermixed  with  small  straight  pedicellari^e 
(pedicellaires  droites).  We  may  give  the  same  name  to  some  of  these 
organs  disseminated  between  the  dorsal  plates. 

Synthetic  Starfish. — At  p.  448  was  noted  an  interesting  form  of 
starfish,  apparently  bridging  over  the  gap  between  the  Stellerida  and 
the  Ophiurida,  which  had  been  described  by  Mr.  W.  Percy  Sladen. 
M.  E.  Perrier  now  describes  *  a  still  more  remarkable  type  obtained 
from  the  Gulf  of  Mexico  during  the  dredging  operations  above 
referred  to. 

This  starfish  is  very  delicate  in  its  structure ;  it  has  a  rounded 
disk  distinctly  separated  from  the  arms,  as  in  the  Ophiurida,  and  the 
arms  are  elongated,  flexible,  and  furnished  with  lateral  rows  of  spines, 
thus  increasing  the  general  resemblance  to  the  Brittle-Stars.  But 
there  are  twelve  arms,  whilst  no  known  Ophiurid  has  more  than 
seven.  The  description  of  the  disk  is  very  curious,  and  nothing  like 
it  is  known  elsewhere  among  starfishes.  It  is  flattened,  very  thin,  and 
quite  destitute  of  any  regular  skeleton,  the  dorsal  membrane  being  in 
fact  literally  a  circular  membrane  stretched  upon  the  ring  formed  by 
the  basal  ossicles  of  the  arms ;  it  is  membranous  and  transparent,  and 
so  close  to  the  buccal  membrane  that  the  stomach  has  only  a  space 
about  equal  to  the  thickness  of  a  sheet  of  paper  in  which  to  lodge. 
M.  Perrier  very  justly  asks  what  can  be  the  usual  food  of  "u  animal 
with  such  a  digestive  cavity  ?  The  dorsal  skeleton  is,  however,  repre- 
sented by  scattered  perforated  calcareous  plates,  each  bearing  a  small 
spine.  Through  the  membrane  the  circular  canal  surrounding  the 
mouth,  and  the  ambulacral  vessels  starting  from  it,  may  be  recognized, 
but  no  csecal  prolongations  of  the  stomach  into  the  arms  were  to 
be  detected.  The  arms  possess  a  double  row  of  ambulacral  tubes, 
but  no  genital  glanfls  could  be  discerned  in  them.  The  skeleton 
of  the  arms  consists  of  four  rows  of  pieces,  two  of  which  form  a  dorsal 
ridge,  and  partially  cover  the  others,  which  are  placed  on  each  side, 
and  each  of  which  bears  a  median  spine  enclosed  in  a  soft  sheath, 
clavate,  and  bearing  at  the  apex  a  tuft  of  pedicellari^,  the  latter  being 
of  the  kind  denominated  "  pedicellaires  croisees  "  by  M.  Perrier,  and 
peculiarly  characteristic  of  the  Asteriadse,  the  most  typical  group  of 
the  true  starfishes.  The  lateral  plates  form  the  borders  of  the  ambu- 
lacral groove,  in  which  the  ambulacral  vessel  rests  exactly  as  in  the 

*  Loc.  cit.     See  '  Pop.  Sci.  Eev.'  (1880)  pp.  380-1. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  963 

Comatulfc,  there  being  no  ambulacral  plates,  sucli  as  occur  in  all 
known  Stellerida. 

M.  Perricr  remarks  that  the  contrast  between  the  arms  and  the 
disk,  the  probable  absence  of  genital  glands  from  the  arms,  and  the 
absence  of  stomachal  cfeca,  would  seem  to  ajiproximate  this  form  to 
the  Ophiurida,  just  as  the  structure  of  the  arms  would  ally  it  to 
the  Comatulie ;  but  although  in  the  abuormal  characters  above  cited, 
and  especially  the  want  of  ambulacral  and  buccal  plates,  it  differs 
from  all  known  Stellerida,  the  evidence  of  the  pedicellarife  leads  him 
to  class  it  in  that  group,  as  forming  an  aberrant  family  of  the  Aste- 
riadas,  in  the  neighbourhood  of  the  genera  Lahidiaster,  Pedieellaster, 
and  Brisimja,  which  also  possesses  only  two  rows  of  ambulacral 
tubes. 

M.  Perrier  names  this  singular  starfish  Uymcnodiscus  Arjassizii. 
It  was  obtained  within  sight  of  the  island  of  JJomiuica,  from  depths 
of  321  and  450  fathoms. 

Formation  of  the  Egg-coverings  in  Antedon  rosacea.* — Dr. 
Ludwig  states  that  a  short  time  before  the  extrusion  of  the  ovum  there 
is  to  be  noted,  on  the  aboral  surface  of  the  pinnulfe,  a  small  circular 
projection,  distinguishable  by  its  whitish  colour  ;  if  we  open  a  piuuula 
at  tliis  stage  and  examine  the  ova  we  find  a  special  disposition  of  their 
surface.  The  whole  egg  ajipears  to  be  invested  by  a  network,  the 
bars  of  which  are  darker  than  the  circular  meshes.  Further  observa- 
tion shows  that  this  network  owes  its  origin  to  a  special  development 
of  the  investment  of  the  ovarian  cell  and  of  the  cell  itself,  for  tlie 
investment  is,  on  its  inner  surface,  villous,  and  the  villi  jiroject  into 
the  yolk-sj)heres  of  the  egg,  so  that  the  rounded  clear  spaces,  already 
noted,  are  merely  the  ojitical  section  of  these  villi.  When  the  eggs 
have  been  for  some  time  subjected  to  the  action  of  sea-water  we  find 
that  the  surface  of  the  egg  has  become  plane,  and  has  got  itself  in- 
vested by  a  thick  shell. 

Ccelenterata. 

The  Ctenophora.f — This  paper  by  Richard  Hertwig  occupies  135 
pages,  and  is  illustrated  by  seven  plates.  The  more  general  results  to 
which  his  investigations  have  led  him  are  the  following : — 

Structure  of  the  Generative  Organs. — Do  these  arise  from  the  ecto- 
dermal or  from  the  endodermal  layer  ?  Among  the  later  writers  wo 
find  Glaus  on  the  one  side  and  Chun  on  tlie  other.  Hertwig  agrees 
with  Claus  in  regarding  them  as  having  an  ectodermal  origin.  Tho 
epithelium  of  the  surface  of  the  body  projects  into  tho  ctenoiihoral 
vessels  in  the  form  of  small  saccules,  which  project  into  the  gelatinous 
layer,  and  reach  as  far  as  the  endodermal  epithelium  of  the  vessels. 
Hero  they  broaden  out  and  form  two  epithelial  layers,  which  are 
separated  by  a  cleft,  the  genital  sinus.  The  layer  which  bounds  tho 
endodermal  epithelium  forms  tlie  generative  products.  As  thiro  are 
uo  blood-vessels,  the  tissues  wliieh  reijuire  a  rit-h  supply  of  nutriment 
are  developed  in  close  connection  with  those  branches  of  the  enteric 

♦  '  Znol.  Anzcig.,'  iii.  (1880)  p.  470. 

t  'Jon.  Zeitschr.  Naturw.,'  xiv.  (1880)  j).  :U3. 


964  RECORD    OF    CURRENT   RESEARCHES   RELATING   TO 

canal  wliich  are  riclily  supplied  with  chyme.  It  is  probable  that  the 
ctenophoral  vessels  of  the  Ctenophora,  which  are  comparable  to  the 
radial  canals  of  the  Medusae,  were,  like  them,  primitively  placed  just 
below  the  ectoderm,  and  that  they  owe  their  changed  position  to  the 
development  of  gelatinous  matter  in  the  disk.  In  their  change  in 
position  they  would  seem  to  have  been  accompanied  by  the  genital 
organs. 

Structure  of  the  Neuro-muscular  System. — After  a  short  account  of 
the  investigations  of  earlier  observers,  and  a  somewhat  more  detailed 
notice  of  those  of  Eimer,  the  author  states  that  in  general  he  finds 
himself  in  agreement  with  the  latter.  He  is  of  opinion  that  there  is  a 
true  nervous  system,  the  elements  of  which  are  to  be  found  in  the 
gelatinous  layer ;  and  he  considers  that  they  are  diffused  through  the 
body  and  do  not  exhibit  any  distinct  centralization.  Such  physiolo- 
gical observations  as  he  has  been  able  to  make  are  found  to  be  in  con- 
cordance with  the  results  of  Eimer.  At  the  same  time  the  agi'ce- 
ment  is  only  of  the  most  general  character.  The  varicosities  which 
Eimer  regards  as  forming  structures  allied  to  ganglionic  cells  are 
regarded  by  Hertwig  as  being  artificial  products.  Yet  again,  Eimer 
finds  no  nerves  in  the  ectoderm,  while  Hertwig  believes  that  he  has 
found  a  well-developed  nerve-plexus  in  that  layer. 

The  author  next  compares  his  results  with  those  of  Chun,  and 
then  proceeds  to  say  that  the  nervoixs  system  of  the  Ctenophora  con- 
sists of  an  ectodermal  and  a  mesodermal  portion.  The  former  has 
the  character  of  a  ganglionic  plexus  which  lies  just  below  the  epithelium 
and  is  equally  distributed  over  the  whole  surface  of  the  body.  In 
Beroe  it  may  also  be  followed  on  to  the  stomach,  where  it  takes  up  a 
position  between  the  gelatinous  and  the  muscular  layer,  in  consequence 
of  the  great  development  of  this  latter.  Only  a  small  number  of  nerve- 
fibrils  are  given  off,  and  these  branch  and  anastomose  very  consider- 
ably. Nowhere  in  the  plexus  is  there  any  indication  of  a  commence- 
ment of  any  centralization.  From  a  priori  considerations  it  is  to  be 
imagined  that  there  is  some  connection  between  uuo  elements  of  the 
plexus  and  the  sensory  cells  of  the  auditory  vesicles  and  the  polar 
areas,  but  this  has  not  yet  been  demonstrated.  In  no  one  case  was  it 
possible  to  detect  nervous  processes  passing  to  the  cells.  The  same 
is  true  as  regards  the  tactile  cells,  which  are  found  everywhere  in  the 
epithelium,  and  especially  in  the  region  surrounding  the  mouth  in 
Beroe.  The  tentacular  apparatus  forms  a  special  division  of  this 
neuro-muscular  system.  The  ectodermal  muscles  are  here  of  enormous 
length,  and  pass  at  their  base  into  epithelial  cells.  To  the  surface  of 
this  layer  they  are  set  perpendicularly. 

The  mesodermal  portion  of  the  nervous  system  would  appear  to 
consist  of  a  very  large  number  of  very  delicate  fibres,  which  are,  at 
points,  provided  with  spindle-shaped  nuclei,  and  are  invested  in  a 
neurilemma.  Like  the  muscular  fibres,  they  pass  separately  into  the 
gelatinous  layer,  and  end  by  branches  in  the  epithelium.  The  pro- 
cesses by  which  they  are  connected  with  this  layer  are  probably  de- 
rived from  the  ectodermal  plexus,  but  of  this  there  is  no  certain 
evidence.     There  does  not  seem  to  be  any  regularity  in  the  mode  of 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  965 

the  distribution  of  the  nerve-fibres  in  the  gelatinous  layer,  the  only 
constant  character  being  the  presence  of  the  eight  branches  which 
underlie  the  meridional  bands.  There  are  very  various  reasons  for 
regarding  these  elements  as  belonging  to  the  nervous  system :  the 
vital  phenomena  of  these  animals  require  it ;  their  histological  struc- 
ture is  very  similar  to  that  of  the  nerves  in  other  Invertebrata ;  and 
their  mode  of  connection  with  the  muscular  fibres  has  a  very  striking 
resemblance  to  what  has  been  observed  in  the  Tardigrada.  On  the 
other  hand,  the  nerves  of  the  higher  animals  arise  from  the  central 
organs  in  the  form  of  filaments  of  considerable  thickness,  and  they 
branch,  as  they  pass  peripherally,  until  they  end  in  a  sensory  organ 
or  a  muscular  fibre.  This  is  not  the  case  with  the  nerve-fibres  of 
the  Ctenophora ;  they  are  branched  at  both  ends,  and  the  terminal 
filaments  never  enter  muscles,  into  which  there  only  pass  small 
lateral  branches. 

On  the  other  hand,  if  these  filaments  are  not  nerves,  can  they  be 
muscles?  Hardly  so,  for  in  that  case  Cydippe  hormiphora,  at  any 
rate,  would  have  muscles  of  the  ordinary  histological  character,  and 
these  very  special  muscles  also.  Nor  can  they  be  a  part  of  the 
suj^porting  system  of  fibres,  for  the  fibres  that  have  distinctly  a  sup- 
I)orting  function  have  no  nuclei,  and  never  become  connected  by 
anastomosis  with  one  another. 

We  come,  then,  to  the  conclusion  that  the  filaments  which  are  dis- 
tributed through  the  gelatinous  layer  of  the  Ctenophora  have  no  close 
resemblance  to  any  elements  found  in  higher  animals,  but  that  they 
are  best  compared  with  the  nerve-fibres  of  the  Invertebrata.  On  the 
physiological  side  their  nervous  function  is  very  distinctly  spoken  to. 

Helaiions  of  the  Ctenophora  to  the  other  Cuelenterata. — The  author 
regards  these  forms  as  being  very  distinct  from  tbe  rest  of  the  group 
in  which  they  are  placed.  To  decide  the  questions  which  have  been 
raised  with  regard  to  this  subject,  we  have,  first  of  all,  to  inquire 
whether  in  the  developmental  history  of  the  higher  animals  there  is 
any  stage  which  is  comparable  to  that  which  is  permanent  in  the 
Ctenophora.  The  nervous  system  of  most  of  these,  at  any  rate,  is 
situated  in  the  mesoderm ;  the  same  is  true  of  these  Coelenterates. 
But  now  it  has  to  be  seen  whether  this  system,  derived  in  both  cases 
from  the  ectoderm,  is  in  the  first  stage  scattered  through  the  mesoderm 
and  only  secondarily  concentrated.  This,  of  course,  is  not  the  case. 
Where  the  nervous  system  remains  ectodermal  in  position,  as  it  does 
in  Some  of  the  higher  Metazoa,  it  is  nevertheless  even  there  concen- 
trated.    Eimer's  hypothesis  is  hereby  negatived. 

Secondly,  there  arises  the  questicjn,  what  relation  have  the  neuro- 
muscular cells  of  Beroii  to  those  of  Uijdra  >  The  only  point  of  resem- 
blance is  that  mode  o"f  continuous  connection  between  muscle  and 
nerve  wliich  always  occurs  in  all  animals  provided  with  these  structures; 
otherwise  there  is  nothing  in  common.  The  ueuro-muscidar  cell  of 
Jli/dra  is  an  cctodeniial,  the  neuro-muscular  fibre  of  Bcror  an  eudo- 
deruuil  structure.  The  sensory  cells  only  become  connected  with  the 
latter  in  a  secondary  fa-hiun. 

The  author  then  shows  how  the  ucuro-muscular  systems  in  the 


966  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

Hydroida  and  Anthozoa  on  tlie  one  hand,  and  the  Ctenopliora  on 
the  other,  are  to  be  regarded  as  having  been  developed  along  two 
different  lines,  having  their  point  of  union  in  a  common  ancestor. 
In  the  Actinife  and  Hydroida  the  nerves  and  muscular  fibres  are 
developed  in  the  epithelium.  Some  epithelial  cells  give  off  muscular 
fibres  at  their  basal  ends,  while  others  form  processes  and  become  con- 
verted into  sensory  cells  or  epithelio-ganglionic  cells.  When  most 
comjiletely  developed,  these  pass  from  the  surface  of  the  body  and  go 
to  form  subepithelial  muscular  cells  or  ganglia.  Wherever  nervous 
elements  are  found  in  the  mesoderm,  they  are  only  migrated  organs. 
In  the  Ctenophora  the  corresponding  mesodermal  parts  do  not  arise  as 
such  in  the  ectoderm,  but  they  there  only  form  indifferent  amoeboid 
cells,  and  they  undergo  their  further  differentiation  after  that  they 
have  changed  their  position.  In  connection  with  this  important  differ- 
ence there  is  yet  another,  which  is  to  be  found  in  the  histological 
characters  of  the  mesodermal  muscular  fibres.  In  the  ActiniaB  and  the 
MedusEe  there  are  bundles  of  muscular  fibres  grouped  around  a  proto- 
plasmic multinucleated  axis  ;  in  the  Ctenophora  the  muscular  fibres 
are  all  of  them  elongated  multinuclear  cells,  which  have  arisen  from 
the  growth  of  a  single  uni-nucleated  cell,  and  which  are  invested  by 
a  covering,  which  is  not  made  up  of  sej)arate  fibrils. 

Led  by  these  facts,  the  author  has  come  to  the  conclusion  that  the 
Ctenophora  have  arisen  from  very  "indifferent"  primitive  forms,  in 
which  the  only  indication  of  the  characteristics  of  the  Coelenterate 
phylum  was  probably  the  tendency  to  a  radially  symmetrical  arrange- 
ment of  the  organs.  Even  the  prehensile  cells  are  so  different  that  it 
is  hard  to  imagine  that  they  had  the  same  origin  as  the  parts  which 
are  regarded  by  Professor  Haeckel  as  being  homologous  with  them  in 
the  other  Coelenterata  ("  stinging-cells ')  ;  and  Hertwig  holds  that  the 
Ctenophora  are  but  very  distant  allies  of  the  rest  of  the  Coelenterata. 

Preparation. — Osmic  acid  was  used  as  a  hardening  material,  carmine 
as  a  colouring.  For  maceration  purposes  a  soluti'-"-  ,f  •  05  jier  cent, 
osmic  acid,  containing  -2  per  cent,  acetic  acid,  was  used.  No  good 
results  were  gained  by  the  use  of  chromic  acid,  bichromate  of  potas- 
sium, or  gold  chloride.  Observations  in  the  fresh  state  are  of  great 
importance. 

General  View. — Along  the  body  of  a  Ctenophore  three  axes  may  be 
drawn.  The  longitudinal  or  primary  passes  from  the  oral  to  the  aboral 
pole,  and  this  is  generally  the  longest ;  the  transverse  axis  can  best  be 
made  out  in  the  tentaculate  forms  ;  the  sagittal  axis  is  perpendicular  to 
the  other  two.  No  true  right  or  left,  dorsal  or  ventral  surfaces  are  to  be 
made  out,  but  only  an  oral  and  an  aboral  end.  The  greater  part  of  the 
body  is  gelatinous,  and  this  portion  is  extraordinarily  rich  in  water. 
The  sensory  body  or  "  ganglion  "  and  the  polar  areas  are  placed  on  the 
aboral  side  of  the  body,  and  the  former  exactly  occupies  the  centre  of 
the  end  of  the  primary  axis.  From  the  sensory  body  there  arise  eight 
ciliated  grooves,  which  are  continuous  with  the  eight  rows  of  cteno- 
l^horal  plates;  these  form  meridional  bands.  The  most  important 
parts  of  the  gastrovascular  system  are  the  stomach  and  the  funnel ;  the 
latter  leads  into  the  peripheral  canal  system,  which  consists  of  three 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  967 

sots  of  vessels.  Then  there  are  the  tentacles,  supj)liecl  by  the  tentacular 
vessels,  and  lastly,  there  are  the  generative  organs  which  follow  tho 
course  of  the  ctenophoral  vessels,  in  the  walls  of  which  the  products 
are  developed. 

There  are  well-marked  differences  between  the  three  layers  of  the 
body.  The  ectoderm  is  the  most  widely  distributed,  inasmuch  as  it 
does  not  only  invest  the  body,  but  also  the  stomach.  It  is,  further, 
the  layer  which  undergoes  the  greatest  amount  of  differentiation, 
formiug  not  only  investing,  but  also  glandular,  pigment,  ciliated  and 
sensory  cells,  in  addition  to  nerves  and  muscles.  The  most  important 
organs  are  nothing  but  sjiecially  differentiated  parts  of  the  ectoderm. 

The  sensory  cells  are  of  two  kinds,  which  so  far  agree  in  structure 
that  they  are  always  provided  with  stiff' processes,  which  have  evidently 
a  tactile  function.  The  most  ordinary  form  of  sensory  cells  is  that 
which  carries  a  number  of  small  tactile  processes.  Of  these  there  may 
be  (Eucharis  multicornis)  as  many  as  seven  ;  others  bear  only  one  pro- 
cess, and  that  of  considerable  length  and  thickness.  The  author  is 
confident  as  to  the  presence  in  the  epidermis  of  a  nervous  layer.  Other 
ectodermal  structures  must  be  here  passed  over,  although  they  exhibit 
many  j^oints  of  considerable  interest. 

The  mesoderm  forms  the  great  mass  of  the  body.  It  is  gelatinous, 
and  in  Callianira,  EucJiaris,  and  Cydippe  is  very  soft,  while  in  the 
Cestidae  and  Beroidse  it  is  much  firmer.  It  does  not  develop  any  sup- 
porting lamella,  and  although  in  itself  completely  structureless,  it 
contains  a  number  of  variously  differentiated  cells.  In  Beroe  ovatus 
there  are  found  to  be  either  muscular  fibres,  nerve-fibres,  or  connective- 
tissiic  corpuscles.  Although  these  are,  when  most  pronounced,  easy 
enough  to  distinguish  from  one  another,  there  are  also  others  which 
seem  to  be  intermediate  in  character.  The  muscles  are  either  radial, 
circular,  or  longitudinal ;  each  fibre  consists  of  an  axial  and  a  cortical 
substance,  together  with  a  sarcolcmma. 

The  endoderm  is  comparatively  uniform  in  character.  It  would 
appear  to  consist  of  a  single  layer  of  ci)ithelial  cells,  flattened  on  ono 
side ;  the  epithelium  of  the  vessels  is  richly  ciliated ;  distinct  and 
well-marked  stomata  are  to  be  observed,  by  means  of  which  fluid  can 
jKiss  to  the  mesoderm,  without  any  special  modification  of  the  endo- 
dcrmal  cells  being  necessary.  They  are  boimdod  by  a  rosette  of  cells 
which  call  to  mind,  by  tlicir  arrangement,  the  structure  of  ciliated 
infundibula.    No  nerves  or  muscles  were  to  be  observed  in  this  layer. 

Medusae  and  Hydroid  Polyps  living  in  Fresh  Water.  * — 
Professor  Lankoster  jxjints  out  that  the  tolerance  by  marine  animals  of 
fresh  water  is  a  much  more  freipicntly  observed  fact  in  all  classes, 
than  the  tolcriince  of  seik  water  by  lacustrine  or  fluviatile  forms.  It  is 
undeniable  that  existing  fiesh-water  forms  have  been  developed  by 
adaptation  from  marine  forms,  whilst  it  is  difficult  to  cite  any  instance 
in  which  adaptation  in  the  opposite  direction  ajipears  to  have  taken 
place,  some  few  marine  01igocha;tous  ChiDtopods  and  Pulmouato 
Gasteropods  being  i)erhaps  such  instances. 

*  'Qiuirt.  Jouru.  Mkt.  yd.,'  xx.  (18S0)  pp.  483-5. 


968  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

The  tolerance  by  Medusae  belonging  to  marine  species  of  fresb 
water  under  natural  conditions  was  observed  by  Mr.  H.  N.  Moseley, 
in  New  South  Wales,  and  Professor  Agassiz  writes  :  "  It  strikes  me 
as  if  the  consequences  resulting  from  the  finding  of  the  fresh-water 
Medusa*  had  been  somewhat  overdrawn.  In  the  first  place,  we  have 
two  genuine  fresh-water  Hydroids,  Hydra  and  Cordylophora,  and  in 
the  second  place,  as  far  as  my  experience  goes,  it  is  not  conclusive  of 
so  fatal  an  action  of  fresh  water  on  Meduste  as  Eomanes  would  lead 
us  to  believe  in.  We  have  quite  an  estuary  leading  out  back  of 
Boston  Harbour,  extending  on  the  one  side  to  form  what  we  call  the 
back  bay,  and  beyond  this  up  the  Charles  Eiver  as  far  as  Watertown, 
where  there  is  a  dam,  about  seven  miles  from  the  inner  extremity  of 
the  harbour  proper.  Here  the  Charles  Eiver  falls  into  this  estuary 
as  a  fresh- water  stream  sufficiently  large  at  times  to  atfect  the  saltness 
of  the  estuary  below  it  at  low  tide,  so  that  at  Cambridge,  lialf  way 
from  Watertown  to  Boston,  the  water  is  salt  only  at  the  highest  tides, 
quite  brackish  during  the  first  half  of  the  ebb,  and  comparatively  fresh 
during  the  last  part  of  the  tide.  At  West  Boston  Bridge,  about  one 
mile  from  the  head  of  the  harbour,  the  water  at  the  last  part  of  the 
tide  is  fresh  enough  and  tastes  but  little  salt.  At  this  bridge  there 
is  an  abundance  of  Hydroids  which  thrive  remarkably  well  on  the 
drainage  of  the  district,  and  grow  to  an  unusually  large  size.  The 
species  found  there  which  has  no  free  Medusa  is  Laomedea  gigantea  ; 
while  of  the  Hydroids  which  have  free  Medusae  we  find  Eucope 
diapliann,  E.  pyriformis,  and  Obelia  commissuralis.  All  these  species 
are,  therefore,  twice  during  twenty-four  hours  exposed  to  salt  water 
and  to  nearly  fresh  water,  and  thrive  remarkably  well  under  the 
treatment,  as  must  of  course  theii"  free  Medusae,  which  I  have  caught 
both  at  high  tide  and  low  water — in  salt  and  in  nearly  fresh  water. 

Other  of  our  Medusae  also  find  their  way  into  this  estuary,  and  I 
have  found  in  fresh  water,  at  low  tide,  active  '^"^sice,  Tiaropsis,  and 
also  Aurelice,  which  seemed  unaflected  by  the  large  quantity  of  fresh 
water  in  which  they  were  found." 

Origin  of  the  Generative  Cells  in  the  Hydroida.t — Dr.  Weis- 
mann,  in  the  paper  referred  to  at  page  813  (where  the  following 
should  have  been  inserted)  gives  the  results  of  his  examination  of 
Tiibularia  mesembryanthemum,  Eudendrium  ramosum,  Gonothyrcea  Loveni, 
Sertularella  polyzonias,  Plumularia  setacea,  and  Aglaophenia  pluma. 
He  confirms  the  fact  that  in  some  cases  the  eggs  of  the  Hydroida 
are,  without  doubt,  developed  in  the  endoderm,  while  the  seminal 
cells  are  by  no  means  constantly  developed  from  the  ectoderm. 
Thus  Eudendrium,  Sertularella,  and  Plumularia  have  an  endo- 
dermal  origin  for  their  sperm-cells,  while  Tuhularia,  Gonothyrcea, 
Campanularia,  Hydradinia,  Cordylophora,  and  Hydra  have  the  origin 
ectodermal. 

In  Hydroids  with  sessile  buds,  therefore,  we  find  three  combina- 
tions, out  of  four  which  are,  in  the  nature  of  things,  possible ;  (a)  both 
sets  of    sexual   products   are    developed   in    the   endoderm  {Hydra, 

*  See  this  Journal,  ante,  p.  652.        f  '  Zool.  Anzeig.,'  iii.  (1880)  p.  22G. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  969 

Cordylophora,  and  Tuhularia) ;  (b)  both  arise  from  the  endoderm 
{Eudendrium,  Plnmidaria,  and  Sertularella) ;  (c)  the  seminal  arise 
from  ectodermal,  and  the  ovarian  products  from  endodermal  cells. 
It  is  interesting  to  note  that  no  certain  evidence  is  to  hand  of  the 
fourth  possible  combination  —  the  male  elements  being  developed 
from  the  endoderm  and  the  female  from  the  ectoderm — ever  having 
been  correctly  observed. 

A  further  result  of  his  observations  is  to  be  found  in  the  fact  that 
in  several  Hydroids  the  ovarian  cells  chiefly  arise  in  the  ccenosarc  of 
the  trunk,  and  only  pass,  during  their  growth,  into  the  sexual  knobs. 
This  is,  further,  to  be  confirmed  by  a  reference  to  the  statements  of 
Fraipont  and  of  Van  Beneden.  The  results  of  F.  E.  Schulze's 
researches  on  Cordylophora  would  seem  to  be  explicable  by  supposing 
that  he  did  not  notice  the  very  earliest  stages,  and  that  in  Cordylo- 
pho7-a  the  true  scat  of  the  origin  of  the  cells  is  a  portion  of  the 
ccenosarc  which  belongs  to  the  gonophoral  region. 

Development  of  Hydra.*— Hcrr  Kerschner  has  a  preliminary 
communication  on  the  results  he  obtained,  under  the  direction  of  Prof. 
F.  E.  Schulze.  There  does  not  apjiear  to  be  any  morula-stage  proper. 
A  blastula  apjiears  very  early,  and  at  its  inferior  pole,  or  that  directed 
towards  the  pareut,  there  is  an  invagination  of  cells,  which  go  to 
form  the  endoderm.  There  is  not,  as  Kleinenberg  imagined,  any 
conversion  of  the  ectoderm  into  a  chitinous  investment  for  the  embryo  ; 
but  that  layer  does  give  rise  to  the  connection  between  the  mother  and 
the  embryo.  The  endoderm  cells  increase  by  the  development  of 
numerous  protoplasmic  connecting  cords  ;  and  the  lacunje  between 
them  have  a  counective-tissue-like  appearance,  which  only  becomes 
altered  by  the  closer  approximation  of  the  cells  of  this  layer.  The 
oral  pole  of  the  young  Hydra  corresponds  to  the  vegetative  pole  of 
the  ovum. 

Structure  of  Hydra. t — Herr  Korotneff  finds  that  the  epithclio- 
muscular  cells  of  the  "  foot "  are  to  be  distingmshed  from  the  other 
ectodermal  cells  by  their  cylindrical  form,  their  possession  of  a  highly 
refractive  fibrilla,  and  the  presence  in  their  superior  third  of  a 
similarly  refractive  mucous  secretion,  by  means  of  which  the  animal 
is  enabled  to  attach  itself.  These  elements  he  would  propose  to  dis- 
tinguish as  glandulo-muscular.  At  the  beginning  of  autumn  the 
small,  deei)ly-set  cells  o{  the  ectoderm  begin  to  jiroliferate  actively, 
and,  arranging  themselves  in  groups,  they  push  their  way  between  the 
superjacent  epithelio-muscular  elements.  These  latter  lose  their 
nuclei,  and  Lecome  gradually  absorbed.  The  cells  thus  lost  are 
replaced  by  a  number  of  small  cells,  arranged  in  several  layers.  The 
winter  ectoderm  cells,  thus  fi)rmed,  undergo  a  fatty  degeneration. 
In  consequence  of  the  destruction  of  the  muscular  system,  the  animal 
becomes  considerably  contracted,  the  endoderm  gets  folded,  and  the 
cavity  of  the  animal  completely  disappears.  The  develojunent  of  the 
ova  has  many  points  of  resemblance  to  that  of  the  ectodermal  cells  just 
described  ;  but  it  only  occurs  at  certain  points.     Here  the  lowest  lying 

♦  '  Z(«)l.  Aiiz.eifi: ,'  iii.  (1880)  p.  454.  +  Ibid.,  p.  10.".. 


970  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

cells  increase  in  size,  their  nuclei  become  converted  into  large  germi- 
nal vesicles.  One  of  tliese  vesicles  continues  to  grow,  and  becomes 
the  definite  germinal  vesicle  of  the  egg,  while  the  other  cells  diminish, 
and  go  to  form  part  of  the  investing  cell-layer. 

After  describing  the  further  details  of  the  egg's  growth,  the  author 
points  out  that  in  the  course  of  its  development  there  appear  two 
directive  corpuscles.  The  peripheral  cells  of  the  morula  go  to  form 
the  blastoderm-cells ;  the  nuclei  pass  to  the  outer  margin  ;  the  cells 
increase  in  length,  and  elongate  in  a  radial  direction.  The  endoderm 
is  formed  by  cells  which  arise  in  the  central  portion  of  the  morula. 
Two  covering  shells  can  be  made  out  at  about  this  stage.  One  is 
formed  from  the  parent,  and  one  is  shed  out  by  the  egg  itself.  The 
latter,  primitively  simple,  becomes  thickened  under  the  influence  of 
external  adverse  conditions.  It  was  this  shell-layer  which  Kleinenberg 
regarded  as  the  ectoderm  of  the  embryonic  Hydra.  The  internal 
cavity  is  formed  by  the  centrifugal  growth  of  the  cells  of  the  embryo. 

Porifera. 

External  Gemmation  in  the  Spongida.* — M.  de  Mereschkowsky 
directs  attention  to  this  mode  of  reproduction,  which,  as  compared 
with  the  other  asexual  method  (that  of  the  formation  of  gemmules), 
has  been  but  little  studied ;  the  process  indeed  seems  to  be  rare,  and 
lias  hitherto  only  been  observed  in  the  four  genera  of  the  family  of 
the  SuberitidinfB,  Tethja,  Tetilla,  Suberites,  and  Rinalda. 

After  referring  to  the  observations  of  Bowerbank  and  Oscar 
Schmidt,  the  author  passes  to  the  account  which  he  has  himself  given  of 
Rinalda  arctica  (from  the  White  Sea)  ;  here  he  observed  that  the  whole 
of  the  sponge  was  covered  with  long  conical  protuberances,  hollow  inter- 
nally ;  buds  became  detached  from  these  cones,  and  fixing  themselves, 
gave  rise  to  fresh  sponges. 

The  observations  now.  to  be  recorded  w  — ^  made  on  a  species 
of  Tcthya  from  the  same  sea.     This  sponge  is  not  more  than  one 


EXPLANATION  OF  PLATE  XXL 


(Figs.  1-5  are  natural  size.  Figs.  6-8  x  7,  Figs.  9-11  x  40,  Figs.  12,  13  x  10). 

Figs.  1-3. — Adult  specimens  of  Te/hya  from  the  White  Sea.  On  the  surface 
are  groups  of  buds  ou  peduncles  of  different  form,  length,  and  size. 

Fig.  4. — Probably  a  detached  bud,  throwing  out  in  all  directions  long  fila- 
ments and  protuberances,  which  later  will  bear  buds  at  their  extremities. 

Fig.  5. — Two  specimens  of  tlie  same  Tethya  attached  to  tlie  interior  surface  of 
a  Tcrehratula,  without  buds  or  any  kind  of  protubcrnuces  on  the  surface. 

Fig.  6. — On  a  long  peduncle  originating  from  the  mother-body  x,  is  a  bud  of 
irregular  form  a,  on  which  are  other  buds,  6,  c,  d. 

Fig.  7. — Metamery  in  the  disposition  of  the  buds. 

Fig.  8. — Dichotomous  ramifications  of  tlie  peduncle,  having  a  bud  at  each 
extremity.  That  on  the  left  side  seems  to  be  about  to  divide  longitudinally, 
which  will  probably  give  rise  to  further  dicliotoiny. 

Figs.  9-11. — First  stages  of  the  development  of  buds.  In  addition  to  the  long 
spicules,  there  are  smaller  ones  in  the  form  of  stars. 

Figs.  12,  13. — Buds  at  the  surface  of  Tethya  lyncurium,  from  Sicily. 


*  'Arch.  Zool.  Exp.  et  Gen.,'  viii.  (1880)  p.  417. 


JO  URN. R.  MICE..  SOC.  VOL. in,  PL. XXI. 


ymk 


12 


JLxternal  Genima.Ljun  m  the   Spongid^i 


Wtsl,[i&wr>Mn%s.Cv  hxi: 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  971 

centimetre  in  diameter ;  the  body  is  regularly  globular  in  form, 
and  is  often  found  attached  to  the  internal  surface  of  some  shell 
(^Terebratula).  It  is  of  a  clear  yellow  colour,  sometimes  darkened 
to  brown  ;  the  regularity  of  the  external  form  is  seldom  so  well 
marked  as  in  the  large  and  small  specimen  figured  in  Fig.  5,  and,  as 
a  rule  (see  Figs.  1-4),  there  are  conical  or  filamentous  projections 
from  its  surface.  The  strange  ajipearance  produced  by  these  projec- 
tions leads  one  at  first  to  sujipose  that  they  are  parasites ;  this  view 
is  shown  to  be  incoi-rect  by  a  closer  examination.  The  most  frequent 
arrangement  is  shown  in  Fig.  1,  where  we  find  ovoid  or  pyriform  buds, 
romided  at  one  extremity  and  at  the  other  passing  into  a  more  or  less 
delicate  stalk,  ()f  varying  length.  Sometimes  (Fig.  1  a,  2  a)  the  buds 
are  globular,  and  these  are  seen  to  be  "  covered  with  that  layer  of 
organic  matters  which  is  characteristic  of  an  adult  sponge  "  ;  these 
buds  may  even  surpass  in  diameter  the  smaller  specimen  shown  in 
Fig.  5.  The  foot  or  process  which  supports  the  bud  is  merely  a  deli- 
cate cylindrical  filament,  the  length  of  which  may  be  as  great  or  greater 
than  the  diameter  of  the  parent  sponge  (Fig.  3).  In  Fig.  8  we  have 
an  example  of  the  dichotomous  division  of  this  filament.  In  some 
cases  (see  Fig.  7)  we  may  find  examples  of  buds  of  the  second  order, 
or  (as  in  Fig.  6)  a  number  of  secondary  buds  (b,  c)  may  arise  from 
the  primary  one  (a),  and  these  may  be  in  various  stages.  A  tertiary 
bud  (d)  may  also  be  seen  arising  from  the  stalk  of  a  secondary 
bud  (c). 

The  following  is  an  account  of  the  development  of  these  structures ; 
at  certain  points  on  the  surface  of  the  sponge  there  is  an  agglomera- 
tion of  the  syncytium  into  which  there  penetrates  a  number  of  long 
spicules;  this  aggregated  sarcode  forms  a  small  cylindrical  body, 
which  gradually  elongates  ;  the  spicules  already  formed  are  displaced 
by  other  fresh  spicules  ;  the  outgrowing  filament,  after  having  attained 
a  certain  length,  begins  to  form  the  bud  at  its  tip  (Figs.  9,  10,  11)  ; 
the  peduncle  has  no  canal  and  no  j)ores,  so  that  the  bud  cannot  be 
looked  upon  as  being  an  invagination  of  the  wall  of  the  parent  sj)ongo, 
for  the  cavities  which  become  developed  in  it  arise  indei^endently, 
and  have  no  connection  with  the  cavity  of  the  parent. 

General  and  Comparative  Morphology  of  the  Sponges. — To  the 
above  paper  is  appended  an  abstract  of  M.  Mereschk(nvsky's  views  on 
this  subject,  in  which  he  compares  the  sponges  with  the  Hydroida. 

The  formation  of  a  very  sim])le  colony  in  the  Hydroida  is  charac- 
terized by  the  fact  that  tlie  new  individuals  are  not  fortuitously 
attached  to  the  jjarent,  but  follow  a  rigorous  law,  so  ordered  that  tho 
appearance  of  one  individual  or  tentacle  is  tho  signal  for  the  ajipear- 
anco  of  lan  identical  one  oi)posite  to  it ;  after  one  pair  has  been 
developed  others  may  follow,  but  they  arc  always  referable  to  the 
formula  2  n.  Nothing  like  this  is  to  be  observed  in  most  sponges  ; 
the  buds  do  not  seem  to  folhnv  any  law,  and  arise  without  any  order. 
The  second  point  of  diflercnco  is  tliat  in  the  Hydroida  tho  new 
individuals  or  tentacles  form  a  ramified  colony,  in  which  every  indi- 
vidual is  completely  distinct  from  its  neighbours.  Cases  like  this  are 
as  a  rare  exception  {Sycetta  primitiva)  to  bo  observed  among  sponges. 


972  RECOKD    OF    CURRENT    RESEARCHES   RELATING    TO 

but  it  is  not  tlie  rule ;  in  them  the  daughter -individuals  have  their 
walls  fused  together  in  such  a  way  as  to  give  rise  to  the  appearance  of 
a  single  organism.  If,  then,  it  is  allowable  to  regard  the  tentacles 
of  a  Hydroid  polyp  as  individuals  distinct  from  the  hydranth,  we 
have  to  speak  of  it  as  a  polymorphous  colony,  composed  of  individuals 
completely  distinct  and  regularly  arranged,  while  the  sponge  is  formed 
by  a  colony  of  individuals  irregularly  arranged  and  fused  into  a  single 
comj^act  mass. 

New  British  Sponge.* — Mr.  J.  G.  Waller  describes  and  figures 
Saphiodesma  minima,  a  new  British  sponge  of  small  size  (x  inch  x 
^  inch),  found  by  him  at  Torquay  on  a  small  pebble  of  limestone,  held 
in  the  roots  of  Laminaria  saccharina.  It  was  unfortunately  not  in  a 
fresh  condition.  The  species  is  but  little  removed  from  _B.  sordida, 
and  but  for  the  absence  of  tricurvate  and  bihamate  spicules,  and  the 
possession  of  long,  hair-like,  acerate  spicules  in  the  membrane,  as  it 
were  in  substitute,  might  easily  be  pronounced  to  be  the  same. 

Mr.  Waller  also  shows  that  Hymeniacidon  macilenta,  of  Bowerbank, 
is  in  reality  an  early  stage  of  B,.  sordida,  of  that  author,f  so  that  the 
former  name  should  be  abandoned. 

Protozoa. 

Infusoria  as  Parasites 4 — Mr.  W.  S.  Kent  directs  attention  to  the 
consideration  of  the  innumerable  forms  of  Infusoria  which  are  referable 
to  the  category  of  "  Parasites  "  in  the  strictest  and  simplest  sense  (as 
distinguished  from  "  Commensals  "), 

Amongst  the  Flagellata  ten  species  are  figured  and  described, 
parasites  respectively  of  frogs  and  other  Amphibia,  the  intestinal 
viscera  of  ducks  and  geese,  the  house-fly  the  blood  of  Indian  rats,  a 
nematoid  worm  ( Trilohus  gracilis),  the  c  \mmon  cockroach,  and  the 
human  nasal  and  respiratory  passages,  the  latter  being  Dr.  J.  H.  Salis- 
bury's Asthmatos  ciliaris,  an  active  agent,  as  he  considers,  in  the  pro- 
duction of  one  form  of  the  infection  known  as  hay  asthma  or  hay 
fever. 

Hexamita  intestinalis,  which  occurs  abundantly  in  that  prolific 
hunting-ground  for  parasitic  organisms,  the  rectum  and  intestine 
of  the  frog,  Ba7ia  temporaria,  has  recently  (in  association  with 
examples  of  this  Batrachian  dissected  at  the  South  Kensington  Bio- 
logical Laboratory)  been  the  object  of  investigation  by  the  author, 
as  the  result  of  which  some  points  of  interest  concerning  the  deport- 
ment of  these  singular  organisms  in  the  fluid  medium  they  inhabit 
were  placed  on  record.  While  usually  described  as  essentially 
free-swimming  organisms,  it  was  found  that  they  possess  the  faculty 
also  of  attaching  themselves  at  will  to  associated  objects,  and  of 
passing  a  temporarily  sedentary  existence.  When  first  transferred 
to  the  field  of  the  Microscope  no  such  pi-operty  is  exhibited,  the 
creatures  hurrying  hither  and  thither  in  the  most  aimless  and  ex- 
cited manner.      Gradually,   however,   their  movements    grow    more 

*  '  Journ.  Quek.  Micr.  Club,'  vi.  (1880)  pp.  97-104,  1  plate. 

t  '  British  Spongiadse,'  iii.  p.  230. 

i  '  Pop.  Sci.  Rev.,'  iv.  (1880)  pp.  293-309,  2  plates. 


INVEltTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  973 

tranquil,  till  at  length  scarcely  an  animalcule  is  to  be  seen  exhibiting 
its  natatory  capacities,  all  with  rare  exceptions  having  attached  them- 
selves to  the  organic  debris  or  other  suitable  fulcra,  through  the 
medium  of  their  two  trailing  posterior  flagella,  which  possess  a 
marked  adhesive  function.  Sometimes  the  entire  lengths  of  these 
filiform  appendages  are  utilized  as  organs  of  adherence,  and  sometimes 
only  their  distal  extremities. 

Under  these  last-named  conditions,  a  highly  remarkable  modi- 
fication of  the  movements  of  the  animalcule  was  observed.  Where 
the  adhesion  is  effected  by  the  entire  length  of  the  flagella,  the 
motion  .of  the  body  is  simply  oscillatory,  the  four  anterior  flagella 
being  deployed  and  agitated  without  apparently  any  definite  plan 
of  action.  When,  however,  adherence  is  accomplished  through  the 
medium  only  of  the  terminations  of  the  flagella,  the  body  gyrates 
rapidly,  and  with  rhythmical  cadence,  from  right  to  left  and  left 
to  riglit,  such  action  causing  the  adherent  flagella  to  become  twisted 
on  each  other,  while  the  four  anterior  ones  describe  elegant  undu- 
lations round  tlie  animalcule's  body.  It  would  seem  highly  pro- 
bable that  the  form  described  by  Professor  Leidy  under  the  title 
of  Trichoni/mpha  ngilis,  found  within  the  intestine  of  the  American 
white  ant,  Termes  Jlnvicans  (likened  by  the  discoverer  to  the  performers 
in  an  American  ballet,  whose  chief  attire  consisted  of  long  cords 
suspended  from  their  shoulders,  whirled  in  mazy  undulations  around 
them  as  they  danced),  represented  a  species  of  Hexamita,  observed 
under  the  conditions  just  described.  Phenomena  precisely  identical 
with  those  just  recorded  of  Hexamita  intestinalis  have  been  found  by 
the  author  to  obtain  also  in  the  non-parasitic  and  marsh-dwelling 
species,  H.  inflata. 

Of  the  Ciliata  fifteen  species  are  figured  and  described,  viz. : 
ectoparasites  of  young  trout,  the  garden  snail,  Hydra  vulgaris,  a 
planarian  worm,  and  the  fresli-water  sponge,  endoparasites  of  man, 
frogs  and  toads,  a  myriapod  {lalus  marginalus),  the  water-beetle 
(Hydrophilus  piceus),  the  earth-worm,  a  marine  planarian,  and  the 
intestinal  and  pulmonary  cavities  of  fresh-water  molluscs. 

Chlorophyll  and  Starch  in  Infusoria.*  —  M.  P.  Van  Tieghem 
mentions  tluit  he  has  often  observed  perfectly  developed  grains  of 
chloropliyll  in  true  Infusoria,  and  notably  in  Stentor  polymorphus. 
Besides  chlorophyll,  the  Euglence  contain  grains  of  starch  (paramylon). 

New  Opalinids.f — In  1879,  M.  E,  Maupas  described  J  Eaptophn/a 
gifjanten,  a  new  Opalinid  from  the  intestines  of  anourous  Batracbia. 
M.  A.  Certes  records  having  also  f(juud  the  Infusorian  in  Bufo  pan- 
ihcrinus  from  Constantine.  Despite  tlie  rapidity  with  which  they  died 
when  removed  from  their  natural  surroundings,  M.  C'ertes  succeeded 
in  preserving  some  alive  for  five  or  six  days  in  albuminous  water,  and 
made  preparations  in  a  mixture  of  osmic  acid  and  33  per  cent,  alcohol. 

M.  Certes  confirms  generally  the  description  given  by  M.  Maupas, 

*  '  Hull.  Bot.  S(>c.  Fraiu-o,'  xxvii.  (1880)  p.  132. 
t  •  Bull.  Soc.  Zool.  France.'  iv.  (1880)  pp.  '2i0-4,  plato  xii. 
;  Sue  liib  Juiiriiai,  ii.  (187'.i)  p.  588. 
VOL.    III.  3    T 


974  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

but  finds  the  buccal  sucker  has  a  double  crown  (internal  and  external) 
of  vibratile  cilia  stronger  than  those  of  the  body.  The  internal  crown 
is  upon  a  kind  of  very  fine  membrane,  and  even  the  bottom  of  the 
sucker  appears  to  bo  ciliated.  Particles  of  carmine  in  the  fluid  in 
which  the  animal  was  swimming  were  drawn  in  by  the  current  set  up 
by  these  cilia  and  accumulated  in  the  funnel  of  the  sucker,  without, 
however,  penetrating  into  the  interior  of  the  body.  According  to 
M.  Maupas,  the  long  contractile  canal  communicates  with  the  exterior 
by  a  certain  number  of  very  small  oval  orifices ;  but  these  M.  Certes, 
though  he  sought  very  carefully  for  them,  was  unable  to  detect. 

M.  Maupas  has  placed  the  animal  amongst  the  Opalinida,  but 
M.  Certes  finds  some  difficulty  in  agreeing  with  this.  The  typical 
Opalinid  (0.  ranarum)  is  remarkable  for  the  large  number  of  its 
nuclei  and  the  absence  of  a  mouth.  There  is  nothing  similar  in 
H.  gigantea.  The  nucleus  is  single ;  the  buccal  sucker  is,  if  not  a 
true  mouth,  at  least  an  organ  sui  generis,  where  the  first  acts  of  nutri- 
tion are  localized.  The  thickness  of  the  cuticle  and  the  clear  layer 
separating  it  from  the  mass  of  the  body  excludes  all  possibility  of 
phenomena  of  endosmosis.  On  the  other  hand,  M.  Certes  does  not 
think  it  right  to  conclude  that,  because  the  solid  particles  of  colouring 
matter  drawn  by  the  cilia  into  the  funnel  of  the  sucker  do  not 
penetrate  the  sarcode  mass,  the  albuminous  liquid,  by  which  the 
animal  is  nourished,  does  not  do  so  either,  and  that  the  sucker  is  only 
an  organ  of  attachment.  Moreover,  the  animal  is  more  often  found 
attached  to  the  small  Tcenice  of  the  intestine  of  Biifo  paniherinus  than 
even  to  the  walls  of  the  intestine.  On  these  several  grounds  it  should 
be  considered  to  form  a  link  between  .  the  true  astomatous  species 
(Opalinida)  and  those  which  have  a  we  /-defined  buccal  orifice. 

In  all  probability,  Haptophrya  gigantea  will  not  remain  isolated  in 
this  new  group.  M.  E.  Blanchard  found,  in  1878,  in  the  intestine  of 
an  Alpine  Triton,  an  unknown  Infusorian,  which  at  first  sight 
M.  Certes  thought  was  H.  gigantea  ;  but  a  closer  scrutiny  enabled  him 
to  recognize  diflerences  between  the  two  species,  though  they  were 
evidently  closely  allied. 

In  the  preparations  of  M.  Blanchard  there  is  no  trace  of  a  dorsal 
canal,  nor  does  he  recollect  having  seen  one  in  the  living  animal.  In 
one  of  the  individuals  treated  with  osmic  acid,  there  exists  in  the  pos- 
terior portion  of  the  body  a  large  vacuole  which  may  be  the  indication 
of  the  contractile  vacuole.  The  cuticle  has  a  double  outline  but  is 
destitute  of  the  characteristic  strise  so  conspicuous  in  the  preparations 
of  H.  gigantea.  Finally  (the  most  important  difference),  the  buccal 
sucker  is  replaced  by  an  oval  depression  armed  with  very  strong  cilia, 
and  which  cannot  be  better  compared,  for  form  and  general  appearance, 
than  to  the  mouth  of  a  tiny  whale,  with  its  whalebone.  The  two  ex- 
tremities of  this  depression  are  connected  by  muscular  cords  (strongly 
coloured  by  the  carmine),  arranged  so  that  the  anterior  part  of  the 
animal  seems,  under  a  low  power,  as  though  provided  with  a  horse-shoe 
sucker  abruptly  terminated  in  the  interior  part.  There  are,  besides, 
characters  which  establish  apparently  a  clear  line  of  demarcation,  not 
only  between  the  two  species,  but  also  between  the  Infusorian  of  the 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  975 

Triton  and  Balantidium  elongatum  and  entozoon  that  Stein  has  foiind 
in  Triton  cristatus  and  txeniatus. 

H.  Tr'donis  is  proposed  as  the  name  of  the  new  species. 

Dr.  E.  Everts  has  recently  published  *  the  description  of  an 
Opalinid  (Ojmlina  Discoglossi)  found  by  him  at  Naples,  in  Disco- 
glossus  picfus.  In  size  rather  than  in  general  form,  in  habitat,  in  the 
existence  of  a  single  nucleus,  a  dorsal  canal,  and  a  sucker,  and  also  in 
the  great  analogy  in  the  phenomena  of  reproduction,  this  Opalinid 
singularly  resembles  that  described  by  M.  Maupas,  with  which,  how- 
ever, it  cannot  be  confoiuided. 

Importance  of  Foraminifera  for  the  Doctrine  of  Descent.t — At 
the  63rd  Congress  of  the  Association  of  German  Naturalists  and 
Physicians  held  at  Dantzig  in  September,  Professor  Mobius,  of  Kiel, 
read  a  paper  with  the  above  title. 

He  began  by  quoting  Dr.  Carpenter's  view  that  the  genera  and 
species  of  tlie  Foramiuifera  cannot  be  determined  after  the  usual 
method,  but  that  the  only  natural  classification  of  the  great  mass 
of  difl'erent  forms  is  to  arrange  them  in  accordance  with  their  degree 
of  relationship.  Professor  Mobius  himself  had  come  to  the  con- 
clusion from  his  researches  among  the  Foraminifera  which  he  had 
collected  in  Mauritius  in  1874  that  the  repeatedly  occurring  pecu- 
liarities among  the  Foraminifera  may  serve  and  must  serve  in  form- 
ing an  idea  of  their  nature  and  zoological  position.  The  sarcode 
of  the  Foraminifera  behaves  with  regard  to  the  formation  of  the 
skeleton  and  shell  just  as  does  the  protoplasm  of  the  eggs  of 
the  Metazoa  to  the  formation  of  the  germs  and  of  all  organs  pro- 
ceeding from  them.  Like  the  protoplasm  of  the  egg,  it  possesses  a 
quite  definite  and  hereditary  capacity  for  self-development.  As  con- 
firmatory of  Darwin's  theory  of  descent,  they  possess  a  value  neither 
greater  nor  less  than  that  of  all  other  animal  classes.  The  Professor's 
forthcoming  work  on  the  Foraminifera  of  Mauritius  will  contain  much 
detailed  evidence  in  support  of  his  views. 

In  the  discussion  which  followed,  it  was  suggested  that  the  point 
of  difference  between  the  author  and  Dr.  Carpenter  lay  in  the  fact  that 
Dr.  Carpenter  had  regard  to  the  sarcode  rather  than  to  tlie  skeleton, 
to  which  latter  Professor  Mobius  attached  the  greater  importance. 

New  Moneron.|  —  K.  Mercschkowsky  describes  a  new  form 
(observed  at  Naples),  under  the  name  of  Monojwdium  KowalevsJii/i. 
It  is,  of  course,  non-nucleated,  and  has  a  fairly  consistent  granular 
proto^dasni,  with  rounded  vacuoles,  varying  but  little  in  form.  As  a 
rule  it  only  gives  off  a  single  homogeneous  pseudopodium,  wliich  is 
about  ten  times  as  hmg  as  the  diameter  of  the  mass.  Attaching  itself  to 
a  filament  of  a  Leptolhi-ix,  it  gradually  draws  the  body  after  it. 
When  two  individuals  unite  the  component  mass  breaks  up  into  three. 
This  was  the  only  mode  (jf  reproduction  which  was  observed,  and  the 
observer  has  no  information  to  give  as  to  any  other  process  for  effect- 
ing the  same  result. 

*  'Tijds.  Nederl.  dferk.  Verconijiing,'  iv.  (1879)  pp.  02-96,  plato  iv. 
t  '  Nature,"  x.\ii.  (18S0)  pp.  527-8. 
j  'Zool.  Anzeig.,*  iii.  (I8h0)  p.  l:U». 

3    T   2 


976  RECORD   OF    CURRENT    RESEARCHES   RELATING    TO 

BOTANY. 

A.  GrENEBAIi,  including  Embryology  and  Histology 
of  the  Phanerogamia. 

Division  of  the  Nucleus  in  the  PoUen-Mother-cells  of  Trades- 
cantia.* — According  to  Baranctzky,  the  mother-cells  of  the  pollen  of 
some  species  of  Tradescantia,  especially  T.  virginica,  pilosa,  discolor, 
suhaspera,  and  zebrina,  afford  a  remarkably  good  illustration  of  the 
mode  of  division  of  the  cell-nucleus.  Almost  as  soon  as  division 
commences  they  separate  entirely  from  one  another ;  and  it  is  only 
necessary  to  crush  the  anthers  in  water  under  the  cover-glass  in  order 
to  get  readily  the  cells  swimmiug  about  separately  in  a  state  of  division, 
and  hence  to  observe  the  processes  on  all  sides.  Owing  to  the  thin- 
ness of  the  protoplasm,  the  cells  will  remain  uninjured  for  hours  in 
river  or  spring-water  without  undergoing  any  material  change ;  after 
a  longer  time  the  cell-contents  contract  without  any  formation  of 
vacuoles.  The  nucleus  can  be  readily  made  out,  even  when  the  cells 
lie  only  in  water,  from  its  density  and  sharp  outline.  The  descriptions 
of  the  process  by  previous  observers  are  in  certain  points  incorrect, 
probably  because  it  has  been  observed  in  salt  or  sugar  solutions,  in 
which  the  nucleus  is  not  nearly  so  clear,  instead  of  simply  in  water. 

Very  young  pollen-mother-cells  are  filled  with  a  moderately  dense, 
finely  granular  protoplasm.  The  large  nuclei,  which  are  considerably 
denser,  appear  also  to  be  finely  granular ;  they  have  no  membrane- 
like outermost  layer.  The  behaviour  of  the  nucleoli  is  not  altogether 
clear.  In  T.  zebrma  there  appears  to  be  always  a  large  nucleolus, 
while  in  the  other  species  none  was  clearly  visible,  and  in  some  it  was 
altogether  unrecognizable.  Probably  they  are  always  present  when  the 
nucleus  is  in  a  state  of  rest.  The  division  now  proceeds  in  the  way 
described  by  Hanstein.  The  dense  parts  of  the  nucleus,  which  at  first 
appear  like  fine  granules  without  definite  form,  increase  in  size,  and 
gradually  assume  the  form  of  short  rods  inclined  in  different  direc- 
tions, and  separated  by  a  sparse  clear  matrix.  The  appearance  is, 
indeed,  somewhat  as  if  the  nucleus  were  full  of  bacteria.  A  nucleolus 
can  now  be  detected  in  the  nucleus,  usually  with  definite  outline.  The 
rods  appear  to  be  of  different  lengths,  but  their  terminations  are  not 
readily  made  out ;  they  become  thicker,  while  their  number  decreases, 
and  the  nucleus  becomes  gradually  denser  and  less  transparent.  At 
one  stage  the  appearance  is  more  that  of  uninterrupted  threads  than  of 
rods  or  granules,  and  this  is  probably  the  case  throughout. 

As  the  process  advances,  the  rods  and  threads,  though  increasing 
in  size,  never  lose  their  sharp  outline,  while  the  quantity  of  the  inter- 
mediate matrix  diminishes  considerably.  The  denser  portions  of  the 
nucleus  are  in  its  periphery,  and  in  immediate  contact  with  the  pro- 
toplasm of  the  cell ;  and  this  causes  the  nucleus  to  lose  its  smooth 
outline,  and  to  bulge  out  with  a  number  of  protuberances,  and  it  pos- 
sesses this  mamillated  form  when  the  rods  have  attained  their  full 
size. 

The  mass  of  the  protoplasm  of  the  cell  is  at  first  indistinctly  finely 
*  'Bot.  Zeit.,'  xxxviii.  (1880)  p.  241. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  977 

granular.  When  tlic  diflferentiation  of  the  nucleus  begins,  sharply 
defined  round  granules  appear  in  it,  the  protoplasm  becoming  less 
transparent  as  they  increase  in  number.  These  granules  have  much 
the  appearance  of  starch-grains.  They  frequently  collect  at  one  side  of 
the  cell  or  form  a  ring  round  the  nucleus ;  this  ring  or  sphere  after- 
wards becomes  broader,  the  granules  retreating  towards  the  cell-wall, 
while  the  nucleus  remains  surrounded  by  a  transparent  and  nearly 
homogeneous  protoj^lasm. 

In  the  final  stage  of  the  differentiation  of  the  nucleus,  the  threads 
form  a  dense  convohition,  the  substance  of  which  is  obviously  finely 
granular.  The  line  where  they  meet  the  periphery  of  the  nucleus  is 
very  fine,  and  apparently  not  smooth,  but  granular ;  while  in  the  centre 
of  the  convolution  the  outlines  of  the  threads  are  not  clearly  dis- 
cernible. 

The  next  processes  comprise  the  second  stage  of  development,  the 
phase  of  the  division  of  the  cell-nucleus.  The  outlines  of  the  threads 
become  sharjier  and  their  substance  apparently  denser  and  more  homo- 
geneous ;  and  at  the  same  time  they  begin  to  change  their  position,  so 
as  to  lie  more  or  less  nearly  parallel  to  one  another,  the  convolution 
increasing  at  the  same  time  in  size,  and  assuming  the  form  of  a  plate 
composed  of  serpentine  threads.  Some  among  the  cells  are  dis- 
tinguished from  the  rest  by  their  size  and  transparency,  although  their 
nuclei  have  not  more  than  the  ordinary  size.  The  threads  now  pre- 
sent the  appearance  as  if  they  were  elastic,  and  constantly  endeavouring 
to  free  and  straighten  themselves ;  at  all  events  the  convolution  breaks 
up  eventually  into  small  fragments.  The  nucleus  is  now  practically 
composed  of  a  great  number  of  separate  filiform  fragments,  without 
any  special  distinguishable  intermediate  matrix,  the  threads  appearing 
to  be  surrounded  by  the  same  transparent  cell-contents  which  fill  up 
almost  the  entire  cell-cavity. 

The  division  of  the  convolution,  and  the  development  of  the  two 
new  nuclei,  usually  proceed  in  the  following  way : — The  plate,  com- 
posed of  transverse  coils  of  threads,  becomes  thicker,  often  passing 
almost  across  the  cell-cavity,  and  having  sometimes  somewhat  of  a 
stellate  form.  Tlie  tlireads  at  the  same  time  break  up  into  shorter 
rod-like  fragments,  their  outline  becoming  also  less  sharp.  The  split- 
ting of  the  disk  now  commences  at  right  angles  to  tlie  direction  of  the 
elements  of  the  nucleus,  beginning  usually  at  the  margin  and  advanc- 
ing towards  the  centre.  The  two  halves  begin  at  once  to  separate 
from  one  another,  but  remain  for  a  time  connected  in  the  middle. 
The  intermediate  space  becomes  filled  with  a  very  dense,  opaque,  and 
usually  granular  protoplasm,  in  wliich  a  delicate  striation  is  sometimes 
to  be  seen.  ]>ut  tho  elements  of  the  two  lialvcs  of  the  nucleus  possess 
und(jubtedly  from  the  first  a  certain  polarity,  that  is,  a  tendency  to 
separate  in  t)pposite  directions,  as  may  be  seen  from  the  position  taken 
up  by  single  free  fragments.  The  two  halves  soon  sej)arate  completely 
from  one  another,  and  whvu  they  have  approaclied  ch)so  to  tlie  cell- 
wall  tliey  are  still  composed  of  distiiiguislmblo  rods  or  gi'anules.  The 
elements  of  the  nucleus  gradually  fuse  together,  but  its  structure  is 
still  apparently  not  homogeneous. 


978  RECORD    OF    CURRENT   RESEARCHES    RELATING   TO 

When  the  new  nuclei  begin  to  round  themselves  off,  the  protoplasm 
again  becomes  more  transparent ;  and  the  granules  again  collect  into 
a  peripheral  zone,  which  includes  the  nuclei.  The  nuclear  plate  makes 
its  appearance  suddenly  as  a  dark  granular  streak,  occupying  at  first 
only  the  centre  of  the  cell,  and  rapidly  elongating  on  both  sides  until 
it  reaches  the  periphery  of  the  cell,  and  the  division  is  complete.  It 
is  only  after  the  complete  division  of  the  cell  that  the  definite  forma- 
tion of  the  new  nuclei  commences,  which  gradually  again  attain  their 
original  uniform  finely  granular  structure.  During  the  development 
a  considerable  absorption  of  water  must  take  place,  the  young  nuclei 
becoming  less  dense  and  increasing  at  the  same  time  greatly  in  volume. 

The  four  pollen-cells  which  are  formed  from  a  single  mother-cell 
are,  in  Tradescantia,  always  produced  by  two  successive  bipartitions, 
the  processes  being  in  all  essential  points  the  same  in  the  second 
aivision  as  in  the  first. 

The  description  now  given  applies  to  Tradescantia  virginica,  suhas- 
pera,  and  pilosa.  In  T.  discolor  the  pollen-mother-cells  are  small,  and 
filled  with  granular  but  slightly  transparent  protoplasm,  and  are 
therefore  not  so  favourable  for  observation.  Some  peculiarities  are 
presented  by  T.  zehrina.  The  breaking-up  of  the  nuclear  threads  into 
short,  nearly  oval  fragments  takes  place  at  a  very  much  earlier  period. 
The  nuclear  plate  has  also  more  the  character  of  a  ring,  its  elements 
almost  disappearing  from  the  centre  and  collecting  near  the  periphery. 

The  nuclear  threads  so  often  referred  to  can  be  crushed  out  and 
their  structure  examined  in  water.  They  are  then  seen  to  be  longer 
or  shorter,  often  vermiform  threads,  the  ends  of  which  are  always 
smoothly  rounded  ofi".  Their  substance  is  not  homogeneous,  but  con- 
sists of  a  less  dense  matrix,  and  a  denser  portion  which  assumes  the 
form  of  an  elevated  ridge  running  spirally  round  the  length  of  the 
thread,  and  which  can  be  even  separated  from  its  mass. 

Baranetzky  observed  also  the  course  of  the  division  of  the  pollen- 
mother-cells  in  other  plants,  both  monocotyledons  and  dicotyledons, 
especially  in  Aijapantlms  umhellatus,  Hemerocallis  flava.  Yucca  gloriosa, 
Hesperis  matronalis,  Lathyrtis  odoratus,  and  Pisum  sativum.  None  of 
these  present  any  differences,  except  in  subordinate  points.  In  Pisum 
the  process  is  extremely  similar  to  that  in  Tradescantia  zehrina,  the 
breaking-up  of  the  nuclear  threads  taking  place  at  an  early  period. 
In  Hesperis  the  substance  of  the  nucleus  is  from  the  first  differentiated 
into  rod-shaped,  and  in  Pisum,  Hemerocallis,  and  Yucca  into  perfectly 
isodiametrical  elements.  The  filiform  nature  of  the  dense  elements  of 
the  nucleus  is  therefore  not  a  universal  rule. 

In  conclusion,  the  following  may  be  stated  as  the  three  most 
important  points  in  the  division  of  the  mother-cells  of  pollen  : — 

1.  The  differentiation  of  the  mass  of  the  nucleus;  that  is,  the 
gradual  separation  of  the  dense  substance,  which  then  assumes  tlie 
form,  according  to  the  species  of  plant,  of  long  vermiform  threads, 
shortish  rods,  or  roundish  bodies,  which  may  be  called  the  elements 
of  the  nucleus. 

2.  The  tendency  of  the  nuclear  elements  to  separate  from  one 
another  in  the  equatorial  plane  of  the  cell,  or  rather,  to  approach  the 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  979 

cell-wall  in  this  plane  and  arrange  themselves  into  the  nuclear  plate 
which,  in  Tradescantia  zebrina,  has  the  form  of  a  ring,  and  in  other 
species  of  Tradescantia  of  an  absolute  flattening  of  the  differentiated 
nucleus. 

3.  The  point  where  the  centres  of  attraction  appear  to  be  shifted. 
The  nuclear  elements  are  now  drawn  to  the  opposite  poles  of  the  cell, 
their  separation  being  thus  determined  into  two  distinct  groups  or  new 
nuclei. 

Multinucleated  Cells  in  the  Suspensor  of  Dicotyledons.* — In 
pursuance  of  recent  discoveries  by  the  author  himself,  Strasburger, 
Treub,  Schmitz,  and  others, t  of  the  existence  of  a  plurality  of  nuclei 
in  vegetable  cells,  Hegelmaier  has  closely  examined  and  described  a 
similar  phenomenon  in  the  suspensor  (pro-embryo)  of  certain  dicoty- 
ledons belonging  to  the  tribe  Vicie^  of  Leguminos;c.  The  species 
specially  examined  were  Pisum  saticum,  Lathyrus  sylvestris,  odoratus, 
Ochrns,  pratensis,  stans,  Aphaca,  and  Nissolia,  Orobus  vermis,  niger, 
tuberosus,  and  atbus,  Lens  esculenta,  Vicia  sepium,  pisiformis,  and 
tenuifolia,  and  Cicer  arietinum.  Of  these  the  last  is  the  only  one 
that  presents  any  important  differences  from  the  rest. 

The  peculiarity  presented  by  all  the  species  above  mentioned,  and 
probably  by  all  belonging  to  the  tribe,  is  that  the  fully  developed 
suspensor,  which  is  of  considerable  length,  is  always  composed  of 
the  same  number  of  cells,  viz.  four ;  exceptions  to  this  being  rare 
abnormalities.  The  structure  consists  of  two  parts,  each  composed  of 
a  pair  of  cells.  At  full  maturity  the  cells  of  the  apical  pair  are 
swollen  out,  and  closely  adj)resserl  to  one  another  with  flat  surfaces, 
so  as  to  form  a  roundish  ellipsoidal  or  nearly  spherical  ball.  They 
contain  a  somewhat  coarse-grained  protoplasm  forming  a  parietal 
layer  of  variable  tliickness,  imbedded  in  which  are  large  nuclei 
placed  at  uniform  distances,  the  number  of  these  nuclei  appearing  to 
depend  on  the  size  of  the  ball,  which  varies  with  the  species.  The 
average  number  is  perhaps  from  twenty  to  thirty,  at  least  in  species 
with  large  flowers  and  seeds ;  in  Lens  esculenta  there  were  found 
only  from  twelve  to  sixteen,  in  Vicia  tenuifolia  about  eight,  and  in 
Lathyrus  stans  and  Nissolia  only  four.  When,  as  in  Lathyrus  sylvestris, 
these  cells  are  smaller,  the  number  of  nuclei  is  still  consideral)lo. 

The  two  basal  cells  of  the  suspensor  form,  as  it  were,  a  kind  of 
})edicel  to  the  capitulum ;  its  cells  are  much  narrower,  and  taper  off 
gradually  to  the  base.  The  number  of  nuclei  in  these  cells  is  still 
larger,  and  dt^pends  on  their  size.  In  the  upper,  broader  part  of  the 
j)cdicel  tlu:y  are  imbedded,  at  uniform  distances,  in  the  parietal  proto- 
plasm ;  in  the  lower,  narrower  part  they  are  arranged  in  several  rows ; 
in  the  narrowest  basal  portion  the  protoplasm  is  no  longer  in  the 
form  (if  a  parietal  layer,  but  is  a  mucilaginous  mass  occupying  nearly 
the  whole  of  the  cell-cavity. 

The  form  of  the  nuclei  presents  nothing  remarkable ;  in  each, 
when  mature,  is  a  large,  strongly  refractive,  and  sharply  defined 
nucleolus.     In  old  nuclei  two  nucleoli  are  occasionally  found. 

•  '  IW.  Z(it.,'  xxxviii.  (ISSO)  p.  UVX 

t  iSco  thia  Journal,  ii.  (187l>)  i).  GOO,  and  miL-,  pp.  Ill,  303,  482,  493. 


980  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

All  four  cells  of  the  suspensor  display  a  tendency  to  round  off,  and 
for  the  dividing  cell  walls  to  split  into  two  lamellae,  so  that  they  very 
readily  separate  from  one  another,  as  also  does  the  embryo  from  the 
suspensor,  being  sometimes  attached  to  it  only  by  a  common  external 
layer  of  mucilaginous  protoplasm. 

The  cell  walls  of  the  suspensor  are  extremely  delicate,  and  it 
is  even  doubtful  whether  they  are  composed  of  cellulose  or  any 
isomerical  substance.  The  entire  absence  of  cuticularization  suggests 
the  explanation  oifered  by  Treub,*  that  the  susj^ensory  cells  them- 
selves absorb  nutriment  for  the  embryo,  partly  from  the  integuments 
and  funiculus,  partly  from  the  tissue  of  the  placenta.  The  ovules  of 
the  Vicie^  are,  like  those  of  other  Leguminosge,  campylotropous,  and 
the  chalazal  portion  is  separated  from  the  much  narrower  micropylar 
end  by  an  elevated  ridge.  The  long  suspensor  raises  the  embryo 
into  the  micropyle,  or  even  beyond  it,  which  is  a  great  advantage. 

In  all  the  Viciete,  at  the  time  when  the  formation  of  the  embryo 
commences,  the  ovule  aud  embryo-sac  are  but  slightly  curved ;  there 
is  as  yet  no  nucellar  tissue  ;  the  inner  integument  is  preseat,  but  is 
much  thinner  than  the  outer  one.  The  longitudinal  division  which 
separates  the  two  cells  of  the  lower  part  of  the  suspensor  from  one 
another  is  formed  much  earlier  than  that  which  divides  the  two 
apical  cells  from  one  another.  Sometimes,  even  before  the  latter  is 
formed,  the  nuclei  in  the  two  lower  cells  begin  to  divide.  The  two 
nuclei  thus  formed  lie  in  such  a  position  towards  one  another  as  if  a 
transverse  septum  had  been  formed  between  them ;  but  there  is  never 
the  least  trace  of  such  a  sej^tum.  This  division  of  the  nuclei  then 
advances  from  the  base  towards  the  apex.  Not  until  the  nuclei  in  the 
lower  cells  have  reached  a  certain  number,  at  least  sixteen,  do  those 
in  the  upper  cells  begin  to  divide ;  the  formation  of  division- walls  is 
in  them  also  extremely  rare. 

The  division  of  the  nucleus  is  always  preceded  by  that  of  its 
large  nucleolus,  which  elongates,  and  becomes  constricted  into  a 
dumb-bell-like  form ;  the  entire  nucleus  then  assuming  a  long 
ellipsoidal  or  fusiform  shape ;  but  only  after  the  nucleolus  has 
completely  divided  does  the  constriction  of  the  nucleus  itself  begin. 
While  the  definition  of  the  nucleolus  is  always  sharp,  the  nucleus 
appears,  during  the  process  of  division,  to  coalesce,  at  its  periphery, 
with  the  surrounding  protoplasm. 

Gicer  presents  several  peculiarities  in  the  form  and  development 
of  the  suspensor.  Instead  of  consisting  of  four  multinucleated,  it  is 
composed  of  a  larger  number  of  uuinucleated  cells,  viz.  from  six  to 
nine,  on  the  average  about  seven  pair.  Each  contains  a  large  nucleus 
imbedded  in  the  parietal  protoplasm,  and  subsequently  a  refractive 
spherical  nucleolus.  The  cell-walls,  though  still  thin,  are  consider- 
ably firmer  than  in  the  other  Vicieas.  The  number  of  cells,  and 
consequentlj''  of  nuclei,  in  the  suspensor  of  Cicer  is  not  so  large  as 
that  of  the  nuclei  in  other  genera,  and  may  even  be  not  so  large  as 
that  of  the  nuclei  in  a  single  multinucleated  cell.  Tlie  second 
peculiarity  of  the  embryo  of  Ci'cer— whether  connected  or  not  with 
*  '  Notes  sur  rembryogenie  de  quelques  Orchidees,'  1 879. 


INVERTEBRATA,   ORYPTOQAMIA,   MICROSCOPY,   ETC  981 

the  first  is  uncertain — is  that  the  entire  large-celled  suspensor,  with 
the  exception  of  its  narrow  basal  end,  as  well  as  the  embryo,  is 
surrounded  by  an  endosperm  which  develops  in  the  micropylar  half 
of  the  young  seed  ;  the  base  of  the  suspensor  itself  entirely  fills  up 
the  narrow  pointed  apical  end  of  the  embryo-sac. 

Latex  and  Laticiferous  Vessels.* — M.  E.  Faivre  gives  the 
following  as  the  main  results  of  a  very  careful  study  of  latex  and 
laticifcrs  in  the  embryo  and  seedling  of  Tragopogon  porrifolius. 

The  laticiferous  vessels  are  first  formed  at  the  same  time  as  the 
other  vessels,  in  the  cotyledons,  the  plumule,  and  the  radicle.  They 
are  produced,  like  the  rest  of  the  vessels,  by  the  union  of  cells,  not 
as  simple  intercellular  spaces,  and  then  undergo  further  development 
by  the  elongation  of  jDrotuberances  which  are  already  present  in  their 
wall ;  they  are  simply  or  reticularly  branched  ;  their  ends  are  blind. 
The  laticiferous  vessels  most  closely  resemble  tracheides  in  their 
general  distribution,  and  occur  in  all  parts  of  the  young  plant ;  they 
are  much  more  numerous  in  the  cotyledons  which  contain  chlorophyll 
than  in  the  plumule,  and  still  more  so  than  in  the  radicle.  In  the 
interior  of  the  cotyledons  they  appear  at  once  in  ribbon-shaped  and 
reticulated  groups. 

As  regards  the  latex  itself,  the  author  distinguishes  between  an 
original  latex  (latex  primordial),  which  is  formed  before  the  chloro- 
phyll, and  the  latex  properly  so  called,  which  arises  at  a  later  period. 

The  author  believes  the  latex  to  be  a  reserve-material,  the  essential 
composition  of  which  is  undoubtedly  related  to  that  of  protoplasm. 
It  consists  fundamentally  of  fats  and  nitrogenous  substances,  and  is 
hence  of  great  service  to  the  plant.  It  ajipears  in  the  plant  in 
its  earliest  stages  of  development,  and  is  deposited,  like  other  reserve- 
materials,  independently  of  the  action  of  light  and  of  the  presence  of 
chlorophyll.  When  the  plants  are  etiolated  by  the  removal  of  light, 
they  lose  their  latex,  just  as,  under  similar  circumstances,  the  starch 
stored  up  as  reserve-material  also  disappears.  The  yellow  rays  of 
light  favour  the  production  of  latex,  just  as  they  do  the  formation  of 
starch  or  oil  in  the  chlorophyll-grains.  When  air  is  excluded  under 
a  high  temperature,  the  phenomena  of  etiolation  are  exhibited  in  the 
diminution  both  of  tlu;  latex  and  of  the  protoplasmic  reserve-materials. 
With  access  of  air  and  a  lower  temperature,  the  amount  of  i)roto2)hism 
increases,  as  also,  under  similar  conditions,  does  the  reserve-starch. 
Difterent  soils  cause  an  increase  or  diminution  of  the  latex,  according 
as  they  promote  or  retard  the  development  of  the  plant. 

Rudimentary  Coma  in  Godetia.f — While  investigating  the  de- 
velopment of  the  embryo-sac  in  the  different  genera  of  Onagracea), 
Mr.  J.  M.  Coulter's  attention  was  attracted  to  certain  hair-like  pro- 
jections which  appeared  upon  the  forming  ovule  of  Godctia  (probably 
G.  grandijiora).  A  careful  examination  showed  them  to  be  identical 
in  structure  with  the  forming  hairs  in  the  coma  of  Epili>lnHm.  They 
occurred  almost  exclusively  at  the  chalazal  end,  one  or  two  scattered 

•  '  Mnii.  Acad.  Sci.  Lyrm,'  xxiii.  (1878-79)  p.  3G1.  Sec  '  Bot.  Contialbl.,'  i. 
(1880)1).  747. 

t  'Hot.  Gazette'  (hi<liiiim),  v.  (18S0)  p.  7.").    Sie  '  Natur.,'  xxii.  (1880)  p.  595. 


982  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

ones  being  detected  farther  down  upon  the  raphe.  A  study  of  the 
development  of  the  coma  of  Epilohium  shows  that  the  first  indication 
of  it  is  a  tuberculated  appearance  of  the  chalazal  end.  Presently 
these  tubercles  push  out  into  elongating  nucleated  cells,  which 
eventually  develop  into  the  long  hairs  of  the  coma.  Now  Godetia 
permanently  retains  this  tuberculated  margin  at  the  upper  end,  but 
does  not  usually  develop  its  coma  any  further.  In  the  cases  examined, 
however,  the  forming  ovules  (either  in  reminiscence  or  prophecy) 
stretched  out  their  tubercles  into  incipient  hairs.  Tracing  these 
ovules  in  their  subsequent  development,  it  was  found  that  these  hairs 
gradually  disappeared  until,  when  the  ovules  had  become  anatropous, 
there  was  no  indication  of  them. 

As  Godetia  has  been  merged  into  CEnothera,  many  species  of  the 
latter  were  examined  to  see  if  any  such  thing  occurred  in  them  ; 
but  no  trace  of  such  growth  was  detected.  This  would  seem  to 
indicate  that  if  Godetia  be  not  entitled  to  generic  rank,  it  is  at  least 
that  part  of  CEnothera  which  approaches  Epilohium.  A  discrepancy 
must,  however,  be  noticed  here.  In  Epilohium  the  hairs  of  the  coma 
do  not  begin  to  form  until  the  ovule  has  become  completely  anatro- 
pous ;  but  in  the  Godetia  observed  the  incipient  coma  had  all  disap- 
peared by  the  time  the  ovule  had  become  anatropous,  beginning  to 
form  before  the  nucleus  is  half  covered  by  the  coats.  These  hairs 
appeared  in  gi-eatest  size  and  abundance  when  the  axis  of  the  ovule 
was  at  right  angles  to  its  anatropous  position. 

Nectariferous  Trichomes  of  Melampyrum.*— On  the  under  side 
of  the  bracts  of  Melampyrum  nemorosum  and  arvense  are  minute  scales, 
in  the  former  case  colourless,  in  the  latter  a  dark  violet,  which 
E.  Eathay  has  determined  to  be  nectariferous  glands,  freely  visited  by 
ants ;  and  similar  organs  occur  also  in  other  species  of  Melampyrum. 
The  secretion  contains  at  least  2  per  cent,  of  sugar,  which  does  not 
reduce  copper-oxide  in  the  cold.  This  secretion  is  rapidly  replaced 
if  removed  from  the  scales.  In  addition  to  ants,  the  secretion  is 
eagerly  devoured  by  other  hymenopterous  insects,  especially  humble- 
bees.  The  gland  itself  consists,  in  the  species  M.  arvense,  nemorosum, 
pratense,  and  hnrhatum,  of  a  short  pedicel-cell  and  a  circular  peltate 
disk,  composed  of  a  single  layer  of  prismatic  cells.  They  belong  to 
the  structures  called  by  de  Bary  epidermal  glands  ;  since  they  excrete 
a  fluid  on  the  upper  side  of  the  disk  between  the  cuticle  and  the  cell- 
wall  of  the  prismatic  cells,  which  is  freed  by  the  rupture  of  the  cuticle. 

With  regard  to  physiological  function,  the  author  is  unable  to 
agree  either  with  the  explanation  of  Kerner  of  the  purpose  of  extra- 
floral  nectaries,  that  they  attract  insects  which  would  otherwise  attack 
the  flowers  and  other  essential  organs,  or  with  that  of  Delpino  and  Belt, 
that  they  attract  insects  which  are  hostile  to  and  destroy  those  that  are 
injurious  to  the  plant,  but  does  not  offer  any  explanation  of  his  own. 

Threads   of  Protoplasm  on  Glandular  Hairs  of  Silphium.t— 
According    to   Dr.  F.  Ludwig,  these  hairs  on  the  inner  side  of  the 
leaf  of  Silphium  perfoliatum  have   been  found    to  bear   oscillating 
*  'SB.  k.  Akad.  Wiss.  Wien,'  Ixxsi.  (1880)  p.  55. 
t  'Kosmos,'  vii.  (1880)  p.  47. 


INVERTEBKATA,    CRYPTOGAMIA,   MICROSCOPY,    ETC.  983 

threads  of  protoplasm,  which  may  be  extended  to  a  greater  or  less 
distance,  or  may  be  retracted,  and  resemble  in  all  points  those  of 
Dipsacus.  The  leaves  of  Silphium  are  also  united  into  a  kind  of  cup 
as  in  Dipsacus,  and  probably  serve  both  as  a  reservoir  of  water  to 
protect  them  against  the  attacks  of  insects  and  mollusca,  and  as  a  trap 
to  catch  insects  for  the  sake  of  the  nutriment  derived  from  their  bodies. 
It  is  suggested  that  the  occurrence  of  these  threads  in  connection  with 
the  leaf-cups  in  the  two  genera  probably  shows  a  certain  relationship 
between  tlie  two  parts,  and  the  former  one  probably  utilized  for  the 
absorption  of  nitrogenous  substances  from  the  water,  as  supposed  by 
Darwin  to  be  the  case.  The  glands  of  Silphium  differ  from  those  of 
Dipsacus  in  their  multicellular  stalk,  unicellular  elliptical  head, 
smaller  size,  and  greater  numbers. 

Resin-passages  in  the  Coniferae.*  —  As  a  sequel  to  previous 
investigations  of  the  subject,t  T.  F.  Hanausek  has  now  examined  the 
resin-passages  in  the  cone-scales  of  Pinus  Laricio,  Abies  pectinata,  and 
A.  Larix,  with  the  following  results. 

Tlie  epithelium  of  the  resin-passages  is  neither  lignified  nor 
suberized,  but  consists  of  cellulose  only,  with  the  exception  of  that  of 
Biota  and  Abies  pectinata,  which  undergoes  a  transformation  resembling 
suberization.  In  the  cone-scales  of  conifers  there  are  both  schizo- 
genous  and  lysigenous  resin-receptacles,  the  former  in  the  bast-fibre- 
zone,  the  latter  abundantly  in  the  fundamental  tissue.  The  position 
of  the  resin-passages  appears  often  to  depend  on  the  position  and 
development  of  the  vascular  bundles,  and  to  be  associated  with  their 
formation. 

The  author  distinguishes  four  kinds  of  resin-formation  : — (1)  The 
resin  may  be  formed  as  a  true  secretion  in  true  secretive  organs.  (2) 
It  may  arise  from  a  deliquescence  of  the  outer  walls  of  particular  cells 
(schizogenous  resin-passages).  (3)  From  metamorphosis  of  the  entire 
cell-wall  and  cell-contents  (lysigenous  and  pathological  resin-pas- 
sages). (4)  By  the  transformation  of  certain  contents  ;  this  frequently 
occasioning  an  increase  of  the  resin  formed  in  the  2nd  and  3rd  modes. 

In  the  cones  of  Finns  and  Biota,  which  remain  green  for  so  long  a 
time,  the  resin,  which  frequently  escapes  and  flows  over  the  outside  of 
tlie  scales,  must  serve  as  a  protection  against  the  attacks  of  birds  ; 
when  the  scales  become  woody  and  nearly  free  from  resin,  the  seeds 
arc  already  ripe,  and  no  protection  is  necessary. 

Influence  of  Light  on  the  Transpiration  of  Plants.^— The  re- 
sults of  the  experimental  researches  of  M.  11.  Comes  a"ree  entirely 
with  the  facts  already  obtained  on  physical  principles,  and  he  sums 
them  up  in  the  following  projjositions  §  : — 

1.  The  emission  of  aqueous  vapour  which  takes  place  in  plants  is 
subject  not  only  to  the  action  of  the  physical  agents  which  influence 

*  '  JB.  N.  Oestr.  Laiidca-olKTical-  u.  Ilandelsch.  in  Krciiis,'  xvii.  (1880)  Seo 
'  Bot.  Cuntrulbl.,'  i.  (ISSO)  p.  TTC 

t  Sec  this  Joiiriiiil,  miti-,  |>.  1 1:!. 

X  '(Joinptcs  ReiitluH,'  xci.  (18.S0)  p.  335. 

§  Tho  dctiiilH  of  tlie  txpcriiiu'iits,  tlio  nunicrit-al  flntii,  plutea,  &c.,  will  bo 
published  iu  '  Atti  U.  Accad.  Liiicui '  (Mem.),  vii.  (1880). 


984  EECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

ordinary  evaporation  from  a  free  surface  of  water,  but  also  to  the 
influence  of  light.  Consequently,  under  similar  conditions,  a  plant 
transpires  more  under  the  action  of  light  than  in  darkness. 

2.  The  action  exerted  by  light  on  the  transpiration  of  plants 
augments  in  proportion  to  its  intensity ;  consequently  under  similar 
conditions  transjiiration  reaches  its  maximum  shortly  after  noon. 

3.  Light  favours  transpiration  only  by  that  part  which  is  absorbed 
by  the  colouring  substance  of  the  organ  ;  therefore,  under  similar  con- 
ditions, the  organ  which  is  coloured  with  the  greatest  intensity 
transpires  more,  and  the  transpiration  is  most  active  in  the  part  of  the 
spectrum  where  the  light  is  most  absorbed. 

4.  The  luminous  rays  which  are  absorbed  by  the  colouring  sub- 
stance of  an  organ  alone  favour  the  transpiration  of  the  organ  ;  there- 
fore, under  similar  conditions,  the  transpiration  of  a  coloured  organ 
will  attain  its  minimum  under  the  influence  of  light  of  the  same  colour 
as  the  organ,  and  its  maximum  under  the  influence  of  the  comple- 
mentary colour, 

Heliotropism.* — In  a  preliminary  account  of  a  recent  series  of 
observations  on  heliotropic  phenomena,  J.  Wiesner  gives  the  following 
as  some  of  the  more  important  points  arrived  at. 

In  very  strong  light,  even  rays  which  have  no  heliotropic  proper- 
ties, possess  under  certain  circumstances  the  property  of  strongly 
retarding  growth.  The  prevalent  theory  that  only  rays  belonging  to 
the  more  refrangible  half  of  the  spectrum  have  the  power  of  inducing 
heliotropism  and  hindrance  to  growth  must  be  modified,  since  the 
ultra-red,  red,  orange,  and  even  yellow  rays,  possess  this  jiroperty 
under  certain  conditions.  The  liability  to  heliotropism  is  always  the 
result  of  the  relatively  greater  extensibility  of  the  cell-wall  on  the 
shaded  side  of  the  organ  ;  but  the  curvature  itself  is  only  completed 
by  turgidity.  Positive  heliotropism  and  negative  geotropism  act  in 
opposition  to  one  another  in  erect  organs ;  in  vertical  organs  which 
grow  downwards  the  heliotropic  and  geotropic  effects  co-operate. 
Whenever  heliotropism  depends  on  definite  mechanical  processes 
which  take  place  in  the  cells,  it  must  be  regarded  as  a  phenomenon 
of  adaptation,  and  may  commence  even  in  organs  which  have  not 
themselves  any  reference  to  light  in  their  functions.  The  author 
believes  the  physiological  purpose  of  heliotropism  to  be  to  place  in 
the  most  favourable  intensity  of  light  those  flowers  which  are  de- 
pendent on  insect-fertilization.  In  those  plants  where  heliotropism 
would  be  injurious,  no  tendency  is  found  towards  heliotropic  curva- 
ture. 

Formation  of  Chlorophyll  in  the  Dark.f — M.  d'Arbaumont  has 
followed  out  the  investigations  of  M.  Flahault  |  respecting  the 
apparent  exceptional  formation  of  chloroj^hyll  without  access  of  light. 
The  case  to  which  he  has  paid  especial  attention  is  that  of  the  appear- 
ance of  chlorophyll-grains  in  the  internal  tissue  of  the  ripe  fruit  of  the 

*  '  SB.  k.  Akad.  Wiss.  Wien,'  Ixxxi.  (1880)  p.  7. 
t  '  Bull.  Soc.  Bot.  France,'  xxvii.  (18S0)  p.  89. 
J  See  this  Journal,  ante,  p.  298. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  985 

pumpkin  (^Cucurhita  maxima).  They  were  invariably  found  in  tlie 
large  cells  with  thin  walls  near  the  carpellary  furrows,  or  near  the 
seeds  in  the  variety  known  as  "  Potiron  jaune  gros." 

M.  d'Ai'baumont  is  of  opinion  that  neither  of  M.  Flahault's 
hypotheses — that  the  grains  are  formed  in  a  young  and  semi-trans- 
parent condition  of  the  tissue  or  at  the  moment  of  exjjosure — will 
apply  in  the  present  case  ;  but  that  they  are  actually  formed  in  the 
dark.  In  support  of  this  view  he  cites  the  fact  that  he  has  observed 
in  this  situation  grains  of  chlorophyll  in  an  active  and  not  in  a  dor- 
mant state,  viz.  actually  in  various  stages  of  division,  or  evidently 
only  just  formed  in  cells  which  have  quite  recently  divided.  He 
further  observed  that  the  cells  containing  chlorophyll  were  always 
situated  either  in  contact  with  or  in  close  proximity  to  reservoirs  of 
nutrient  substances,  and  especially  to  deposits  of  starch.  The  grains 
of  chlorojihyll  are  dissolved  in  two  ways,  centrifugally  or  centri- 
petally,  i.  e.  either  advancing  from  the  centre  towards  the  periphery, 
or  the  reverse. 

Chlorophyll  in  the  Leaves  of  the  Canada  Vine.* — According  to 
Schnetzler,  the  red  leaves  of  the  Canada  vine  (Ampelopsis  hederacea) 
still  contain  chlorojihyll,  which  is,  however,  concealed  by  a  red  sub- 
stance soluble  in  alcohol.  Chlorophyllin  can  be  separated  from  it  by 
means  of  ether,  but  is  present  in  very  small  quantities  in  jjroportiou 
to  tlie  red  pigment.  This  latter  is  probably  a  derivative  of  chloro- 
phyll, but  not  identical  with  it.  If  potassa  is  added  to  the  red  alco- 
holic solution,  it  becomes  of  a  beautiful  green  colour,  but  is  not 
fluorescent,  by  which  it  is  distinguishable  from  true  chlorophyll. 

Absorption  of  Water  by  the  Leaves  of  Bulbous  Plants.f — From 
experiments  on  this  subject  made  on  a  hyacinth  deprived  of  its  dry 
tunicated  coats,  the  leaves  of  which,  but  not  the  bulb,  were  plunged 
in  water,  M.  Mer  deduces  the  following  conclusions : — 

The  leaves  of  bulbous  plants  absorb  the  water  in  which  they  are 
immersed,  so  as  to  bring  them  to  the  condition  maintained  by  the 
bulb  in  free  air.  The  absorption  goes  on  without  there  being  any  need 
first  to  diminish  their  turgidity,  simply  in  consequence  of  the  flow  of 
water  caused  by  the  transpiration  of  the  bulb.  The  current  from 
below  upwards  (the  plant  being  reversed)  is  not  so  strong  as  it  would 
be  in  the  ojjposite  <lirection  when  the  leaves  are  slightly  withered. 
The  renewal  of  turgidity  is  therefore  due  in  part  to  the  water  derived 
from  the  bulb ;  it  is  only  from  this  source  that  the  leaves  draw  it 
when  the  experiment  is  made  under  a  bell-glass,  and  when  the  bulb 
is  still  fresh.  Tliey  do  not  absorb  the  external  moisture  when  other- 
wise sufficiently  sup])lied'\vith  water. 

Disengagement  of  Carbonic  Acid  from  the  Roots  of  Plants.^ — 
In  pursuance  of  his  former  investigation  of  this  subject,  us  previously 

•  '  Bull.  Soc.  Vaud.  Sci.  Nat.,'  xvi.  (1880)  p.  701.  Sec  '  Bot.  Cciitralbl.,'  i. 
(1880)  p.  <;5."). 

t  '  Bull.  Soc.  Bot.  Franco.'  xx\i.  (1870)  xli.-iv. 
X  ll.i.l.,  xxvii.  (1880)  p.  XVS. 


986  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

reported,*  M.  Cauvet  now   adds  the  following  as  definite  conclu- 
sions : — 

1.  The  roots  of  plants  are  constantly  disengaging  carbonic  acid. 

2.  This  exhalation  is  less  active  by  night  than  by  day. 

3.  The  disengagement  increases  at  sunrise,  diminislies  towards 
the  middle  of  the  day,  and  increases  again  in  the  evening. 

4.  The  exhalation  is,  in  proportion,  more  considerable  during  any 
one  diurnal  period  than  during  the  night. 

5.  The  activity  of  the  roots  is  hence  less  by  night  than  by  day,  at 
least  as  respects  their  respiration. 

6.  If  the  root  absorbs  carbonic  acid  from  the  soil,  it  is  possibly 
only  that  which  has  served  for  the  dissolution  of  the  insoluble  salts, 
carbonates,  phosphates,  &c.,  necessary  to  the  life  of  the  plant. 

Digestive  Principles  of  Plants.f — Dr.  Lawson  Tait  has  recently 
investigated  afresh  the  digestive  principles  of  plants.  While  he  has 
obtained  complete  proof  of  a  digestive  process  in  Ceplialotus,  Nepenthes, 
Dioncea,  and  the  Droseracese,  he  entirely  failed  with  Sarracenia  and 
Darlingtonia.  The  fluid  separated  Irom  Drosera  hinata  he  found  to 
contain  two  substances,  to  which  he  gives  the  names  "  droserin  "  and 
"  azerin." 

Dr.  Tait  confirms  Sir  J.  D.  Hooker's  statement  that  the  fluid 
removed  from  the  living  pitcher  of  Nepenthes  into  a  glass  vessel  does 
not  digest.  A  series  of  experiments  led  him  to  the  conclusion  that 
the  acid  must  resemble  lactic  acid,  at  least  in  its  properties.  The 
glands  in  the  pitchers  of  Nepenthes  he  states  to  be  quite  analogous  to 
the  peptic  follicles  of  the  human  stomach ;  and  when  the  process  of 
digestion  is  conducted  with  albumen,  the  products  are  exactly  the 
same  as  when  pepsine  is  employed.  The  results  give  the  same  reac- 
tions with  reagents,  especially  the  characteristic  violet  with  oxide  of 
copper  and  potash,  and  there  can  be  no  doubt  that  they  are  peptones. 

Nutrition  of  the  Drosera.| — Contrary  to  the  views  of  Reess  and 
Darwin,  E.  Regel  finds  that  the  plants  thrive  best  when  not  treated 
with  animal  food,  and  is  of  opinion  that  their  sustenance  is  properly 
derived  through  the  roots. 

Botanical  Micro-Chemistry.§ — In  a  Danish  work  on  this  subject, 
V.  A.  Poulsen  gives  a  resume  of  the  most  important  micro-chemical 
reagents,  and  the  modes  of  investigation  employed  in  micro-chemistry. 

The  first  section  treats  of  the  reagents.  In  each  case  the  composi- 
tion is  given,  and  the  cases  in  which  each  reagent  should  be  emj^loyed, 
and  its  characteristic  reactions.  The  second  section  treats  of  vegetable 
substances,  and  the  methods  of  proving  their  presence  by  the  aid  of 
micro-chemistry.    Among  the  substances  thus  discussed  are  cellulose, 

*  See  this  Journal,  ante,  p.  665. 

t  '  Proc.  Birming.  Phil.  Soc.,'  i.  (1880)  pp.  125-39.  See  '  Nature,'  xxii.  (1880) 
p.  521. 

X  'Journ.  Ohem.  Soc.,'  Abstr.  xxxviii.  (1880)  p.  820;  from  'Bied.  Centr.,' 
1880,  p.  482. 

§  Poulseu,  V.  A.,  '  Botanisk  Mikrokemie,'  Copenhagen,  1880  (Danish).  See 
'  Bot.  Zeit.,'  xxxviii.  (1880)  p.  .^26. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  987 

lignin,  suber,  protein  compounds,  protoplasm,  starch,  sugar,  oil,  resin, 
&c. ;  tlie  vegetable  salts,  colouring  substances,  &c. 

Red  Pigment  of  the  Flowers  of  the  Peony.* — J.  B.  Scbnetzler 
has  examined  the  red  colouring-matter  of  the  peony,  and  finds  that 
the  red  alcoholic  solution  assumes,  on  evaporation  in  the  air,  a  bea;i- 
tiful  amaranth-red  colour.  The  dry  residue  is  of  the  same  colour, 
even  under  tlie  influence  of  direct  sunlight.  Calcium  oxalate  changes 
the  purple-red  colour  of  the  alcoholic  solution  into  a  pure  fiery  red. 
If  a  very  dilute  solution  of  calcium  carbonate  is  carefully  poured,  in 
small  quantities,  on  to  the  red  alcoholic  solution,  the  colour  changes 
successively  into  purple,  purple-violet,  blue,  green,  and  yellow.  The 
green  colour  has  a  red  tinge  in  transmitted  sunlight.  When  exposed 
to  light,  the  green  colour  passes  into  yellow  ;  and  this  yellow  colour 
is  not  changed  by  acid  or  alkaline  reagents ;  while  the  green  colour  is 
changed  back  by  acid  reagents  into  red. 

The  reagents  employed  in  these  experiments  are  substances  which 
occur  abundantly  in  the  living  plant,  or,  like  calcium  carbonate,  are 
taken  up  by  it.  If  a  solution  of  ferro-ferrid-oxide  sulphate  is  added 
to  the  dilute  red  alcoholic  solution,  a  blackish-blue  precipitate  is  pro- 
duced, showing  the  jiresence  of  a  substance  belonging  to  the  tannin- 
group.  This  occurs  also  as  an  accompaniment  of  the  red  pigment  of 
the  rose  and  Hibes  sanguineum,  and  appears  to  have  some  genetic 
connection  with  these  colouring-matters. 

More  than  a  hundred  red,  violet,  and  blue  flowers  gave  similar 
results  when  treated  with  the  same  reagents.  In  all  there  is  a 
chromogen  which  is  soluble  in  alcohol,  and  is  coloured  red  by  acid, 
purple-red,  violet,  blue,  green,  or  yellow  by  alkaline  reagents. 

The  Cell  as  an  Element. — See  M.  P.  Van  Tieghem's  paper  on 
'  Social  Bacteria,'  infra,  Fungi. 

B.    CRYPTOGAMIA. 

Cryptogamia  Vascularia. 

Development  of  the  Sporang-ium  in  Vascular  Cryptogams.f — 
K.  Goebel  has  closely  investigated  the  comparative  history  of  develop- 
ment of  the  sporangium  in  vascular  cryptogams,  with  a  view  of  show- 
ing the  close  analogy  displayed  to  tliut  of  the  pollen-sacs  and  ovules 
(microsporangia  and  macrosporangia)  of  flowering  plants.  Previous 
observers  have,  for  the  most  part,  stated  that  the  spores  of  vascular 
cryptogams  result  from  a  sporogenons  tissue  formed  by  irregular  cell- 
division  within  the  sporangium.  The  present  writer  asserts,  on  the 
other  hand,  that  in  vascular  cryptogams,  as  in  phanerogams,  the  spore- 
forming  tissue  can  always  be  traced  back  to  a  single  cell,  or  a  row  or 
layer  of  cells,  which  can,  at  a  very  early  period,  be  distinguished,  by 
the  nature  of  its  contents,  from  the  remaining  cellular  tissue  ;  and 
that  tlie  sporogenons  tissue  results  from  the  perfectly  regular  division 
of  this  primary  cell,  row,  or  layer  of  cells,  to  which  Goebel  applies 
the  term  arrhespore. 

*  '  Hot.  Contnilbl.,'  i.  (1880)  p.  682. 

t  '  Bot.  Zeit.,'  xxxviii.  (1880)  pp.  545-52,  ^^€A-7l. 


988  RECORD    OF   CURRENT   RESEARCHES    RELATING    TO 

In  the  typical  FilicineaB,  the  course  of  development  of  the  sporan- 
gium is  well  known.  A  single  epidermal  cell  of  the  leaf  swells  out, 
forming  the  mother-cell  of  the  sporangium,  within  which  a  pedicel- 
cell  is  tirst  of  all  separated  by  a  septum  from  the  mother-cell  of  the 
capsule.  Tliis  last  then  divides  into  four  parietal  and  one  central 
cell,  the  latter  being  the  archespore,  distinguished  by  the  largo 
amount  of  protoplasm  that  it  contains,  from  which  the  spore-forming 
tissue  is  developed.  The  archespore  then  forms  two  layers  of  so-called 
"  mantle-cells,"  surrounding  the  central  cell,  and  corresponding  to 
the  "  tapcten-cells "  in  the  pollen-sac  of  phanerogams.  The  arche- 
spore is,  therefore,  in  the  typical  FilicineiB,  a  Jiypodermal  cell. 

In  the  Ophioglossacete,  the  process  is  somewhat  different,  the 
sporangium  originating  not  from  a  single  cell,  but  from  a  mass  of 
cells.  The  young  sporangia  of  ButrycMum  Lunaria  are  masses  of 
cells  forming  a  hemispherical  protuberance.  Notwithstanding  the 
contrary  statement  of  Eussow,  the  archespore  from  which  the  sporo- 
genous  tissue  is  developed  is  here  also,  as  in  typical  ferns,  a  single 
cell,  although  occupying  a  different  position.  The  archespore  is  here 
the  terminal  cell  of  the  axial  row  which  lies  beneath  the  still  uni- 
lamellar epidermis,  and  is  distinguished  from  the  adjacent  cells  by 
its  abundant  protoplasm,  soon  also  surpassing  them  in  size.  The 
mantle-cells  are  formed  by  divisions  in  the  epidermal  cell  which  lies 
immediately  above  the  arcliespore.  The  archespore  at  the  same  time 
divides  into  four  daughter-cells. 

The  development  of  the  sporangia  of  the  Equisetacese  closely 
resembles  tliat  of  Botrychium.  The  archespore  is  here  also  the 
terminal  cell  of  a  hypodermal  row,  formed  on  the  under  side  of  the 
sporangiojjhore,  and  is  originally  unicellular  ;  the  sporogenous  tissue 
resulting  from  its  division.  In  specially  vigorous  sporangia  it  is 
possible  that  it  may  occasionally  be  bicellular,  and  it  at  all  events 
divides  longitudinally  at  a  very  early  period  into  two  cells.  The 
mantle-cells  are  formed  in  the  same  way  as  in  Botrychium,  but  are  not 
so  sharply  defined. 

Closely  resembling  the  processes  above  described  is  that  in  Lyco- 
podium  (Selago).  The  sporangium  arises  at  the  base  of  the  leaf,  and 
attains  its  subsequent  axillary  position  by  displacement ;  it  originates 
from  a  few  cells.  The  centre  one  of  these  grows  the  most  vigorously, 
and  subsequently  gives  rise  to  the  archespore.  As  in  Botrychium  and 
Equisetum,  the  archespore,  distinguished  by  its  size,  abundant  proto- 
plasm, and  the  power  of  swelling  of  its  cell- wall,  is  the  teiminal  cell 
of  an  axial  row  lying  beneath  the  wall  of  the  young  sporangium.  In 
L.  annotinum  and  other  species  the  processes  appear  to  be  the  same. 

In  Isoetes,  the  origin  of  the  sporangium  is  a  group  of  cells  at  the 
base  of  the  leaf.  In  its  earliest  stage  the  archespore,  both  of  the 
macrosporangium  and  the  microsporangium,  is  here  not  a  single  cell, 
but  is  composed  of  a  layer  of  cells.  A  difference  then  sets  in  between 
the  development  of  the  microsporangia  and  macrosporangia.  In  the 
former  the  archespore- cells  elongate  in  a  direction  vertical  to  the 
surface,  and  divide  by  septa.  No  difference  is  yet  discernible 
between  the  sterile  and  fertile   cells  ;  but  subsequently  some  rows 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  989 

of  cells  are  arrested  in  their  growth,  lose  their  abundant  protoplasm, 
and  divide  only  into  elongated  tubular  cells.  These  are  the  sterile 
cells  or  trabeculjB.  The  sporogenous  cells,  continuing  to  grow  and 
retaining  their  protoplasm,  divide  only  by  transverse  se^^ta.  In  the 
macrosporangium  the  fertile  cells  of  the  archespore  undergo  no 
further  divisions  than  those  which  result  in  the  formation  of  the 
mantle-cells. 

A  close  analogy  may  be  drawn  between  the  development  of  the 
macrospore  of  Isoetes  and  that  of  the  embryo-sac  of  jihanerogams, 
the  chief  difference  being  that  the  mother-cells  are,  in  the  former  case, 
numerous,  while  in  the  Litter  case  there  is  usually  only  one.  In  the 
Coniferae  the  mother-cells  of  the  embryo-sac  (archespore)  originate 
from  the  hypodermal  layer,  and  their  depression  in  the  interior  of  the 
macrosporangium  corresjjonds  to  that  in  Isoetes.  In  both  cases  the 
embryo-sac  consumes  the  surrounding  tissue.  Occasionally,  in  gymno- 
sperms,  there  is  more  than  one  embryo-sac  mother-cell ;  but  they  are 
not  then,  as  in  Isoetes,  separated  by  a  sterile  tissue  (the  trabecul£e). 
In  angiosperras  and  in  Ephedra,  the  archespore  has  been  shown,  by 
Warming  and  Strasburger  respectively,  to  consist  of  a  layer  of  cells, 
as  in  Isoetes.  A  similar  comparison  may  be  drawn  between  the  deve- 
lopment of  the  microsporangium  of  Isoetes  and  that  of  the  pollen-sac 
of  phanerogams. 

In  the  Bryineae  and  Sphagnace^  the  archespore  consists  of  a  layer 
of  cells ;  and  this  is  also  the  case  in  certain  Hepaticfe,  certainly  in 
the  Anthoceroteaj ;  while,  in  Biccia,  there  is  no  separation  into  a  sterile 
part  of  the  capsule  and  an  archespore. 

Muscineae. 
Structure  of  the  Stem  of  Mosses.*— M.  I'Abbe  Hy  has  carefully 
studied  the  structure  of  tlie  stem  of  mosses  belonging  to  the  family 
Polytrichaceae,  especially  of  the  species  Atnchum  iindulatum  and  Poly- 
trichum  commune.  The  following  is  a  summary  of  the  most  important 
results : — 

1.  The  anatomical  structure  of  the  stem  in  this  family  is  more 
complex  than  has  hitherto  been  supposed,  and  includes  six  well- 
marked  different  kinds  of  tissue.  One  of  these,  termed  by  Schimpcr 
the  woody  tissue,  is  itself  made  up  of  three  characteristic  regions. 

2.  The  stem  is  not  miifurm,  nor  reducible  to  a  single  type. 
In  one  species,  for  example,  Poli/trichtm  commune,  very  important 
differences  of  structure  may  be  observed  at  different  heights,  which 
may  be  arranged  under  tliree  kinds,  connected  by  intermediate  forms. 
Even  the  external  configuration  varies,  from  cylindrical  to  triangular 
prismatic,  and  irregularly  polygonal  towards  the  summit.  The  dia- 
meter increases  progressively,  from  ^  mm.  to  1]  mm.,  that  is,  about  iu 
the  proportion  of  1-4. 

3.  A  cortical  investment,  similar  in  appearance  to  that  which  has 
long  been  known  in  the  case  of  the  Sphagnaceic,  and  of  which  somo 
traces  arc  also  ftnnul  in  the  genus  Philiniolis,  exists  also  well  developed 
at  the  base  of  the  stem  of  our  indigenous  Poli/lrichums,  and  even  of 

*  'Dull.  Sof.  Bot.  Fmiicc,'  xxvii.  (ISSO)  p.  IOC. 
VOL.    III.  3    U 


990      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

Atrichum  undulatum ;  it  generally  consists  of  three  or  four  layers 
of  cells. 

4.  This  cortical  tissue  has  nothing  in  common  with  that  of  Sphag- 
num except  its  appearance  and  its  physiological  function  ;  regarded 
from  the  point  of  development,  it  is  entirely  diflferent.  It  is  interior 
with  respect  to  the  epidermal  layers,  instead  of  exterior,  as  in  the 
Sphagnacefe. 

5.  The  true  epidermis,  characterized  by  the  presence  of  hairs, 
exists  with  certainty  only  in  the  lowest  and  subterranean  portion  of 
the  axis.  The  absolutely  glabrous  aerial  stem  is  probably  destitute 
of  an  epidermis  properly  so-called  ;  the  zone  distinguished  under  this 
name  by  authors  belongs  in  its  origin  to  the  fundamental  tissue,  from 
which  it  differs  in  its  narrow  coloured  cells.  If  the  true  epidermis 
is  continued  upwards  as  far  as  the  stolons,  it  is  only  on  the  dorsal 
side  of  the  scaly  appendages,  following  two  projecting  lines  bordering 
the  median  nerve. 

6.  The  multiplicity  of  bundles  noticed  by  Sachs  in  PolytricJium 
commune  is  to  be  observed  only  at  the  summit  of  the  stems,  and  is  not 
peculiar  to  this  species.  These  isolated  bundles  in  the  midst  of  the 
fundamental  parenchyma  are  not,  as  Sachs  states,  similar  to  the  axial 
bundle ;  in  addition  to  their  never  containing  any  medulla,  they  are, 
in  the  Polytrichacese,  more  simple  than  this  axial  bundle ;  while,  on 
the  contrary,  in  Atrichum  undulatum,  they  are  remarkable  for  the 
complication  of  their  structure. 

7.  A  ternary  symmetry  prevails  in  the  general  disposition  of  the 
tissues,  but  this  is  strikingly  regular  only  in  the  subterranean  region  ; 
in  proportion  to  the  height  on  the  axis  it  becomes  more  obscure,  and 
finally  completely  disappears. 

Stomata  of  Marchantiacese.* — The  stomata  of  Marchantiaceje 
are,  according  to  Leitgeb,  of  two  kinds,  simple  and  canaliculate.  The 
former,  which  occur  in  Sariteria,  Grimaldia,  Behoulia,  Fegatella,  and 
Targionia,  are  epidermal  pores,  situated  immediately  above  the  air- 
cavities.  The  latter  kind,  found  in  Marchantia  and  Preissia,  appear 
like  canals  excavated  in  the  surface  of  the  thallus,  and  opening  into 
the  air-ca*vities ;  they  occur  also  in  the  fructification  of  all  Marchan- 
tiacea3. 

The  mode  of  formation  of  the  canaliculate  stomata  resembles  that 
of  the  intercellular  spaces  in  the  Eicciea^.  On  the  cells  which  con- 
stitute the  epidermal  layer  at  the  point  of  the  surface  which  lies 
immediately  behind  the  apex,  pit-like  depressions  are  formed  at  the 
angles  of  the  cells,  which  subsequently  assume  the  appearance  of 
canals  penetrating  the  superficial  layer  of  cells.  From  this  layer 
proceeds  the  whole  of  the  dorsal  tissue  of  the  thallus,  which  is 
penetrated  by  air-cavities,  including  the  epidermis,  and  the  mode  of 
growth  of  this  portion  of  the  thallus  determines  whether  the  canals 
retain  their  original  form  or  increase  to  large  air-chambers,  which 
tlieu  either  remain  open  through  their  entire  breadth  or  are  covered 
by  a  growth  which  advances  jxtri  passu  with  their  development. 
The  pits  are  properly  to  be  regarded  as  depressions  of  the  surface, 

*  '  SB.  k.  Akad.  Wiss.  Wieu,'  Jxxxi.  (ISSO)  p.  40. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,   ETC.  991 

formed  by  particular  portions  of  the  epidermis  becoming  covered  by 
the  more  rapid  growth  of  the  adjoining  parts.  The  process  is,  in 
fact,  the  same  as  in  the  formation  of  the  sexual  organs.  The  author 
is  of  opinion  that  the  pores  and  canals  are  primary,  the  air-chambers 
secondary  formations,  notwithstanding  the  occurrence  of  apparent 
deviations,  as  in  Marcliantia. 

AVith  respect  to  the  filling  up  of  the  air-chambers,  they  may 
remain  altogether  empty,  as  in  Sauteria  and  Oxymitra.  But  more 
frequently  segmented  rows  of  cells  proceed  both  from  the  basal  inner 
wall  and  from  the  lateral  walls,  running  towards  the  covering  of  the 
air-chamber ;  this  occurs  in  Marcliantia,  Preissia,  Lunularia,  and 
Fegatella.  Finally,  as  in  liehoulia,  rows  of  cells  grow  out  into  the 
air-chamber  from  all  the  inner  walls  of  the  cells  which  bound  it, 
including  the  covering  while  in  process  of  formation,  thus  dividing  it 
into  a  number  of  imj)erfect  chambers. 

Inflorescence  of  the  Marchantiaceae.* — The  inflorescence  of  the 
MarchantiacciD  takes  the  form  of  disks  sessile  upon  the  thallus  or  of 
umbels  elevated  above  it  on  a  pedicel.  The  best-known  examples  are 
the  male  and  female  inflorescences  of  the  genera  Marcliantia  and 
Preissia.  It  has  long  been  held  that  these  receptacles  and  their 
pedicels  must  be  regarded  as  metamorphosed  foliar  axes ;  as  is  shown 
by  (1)  the  remarkable  coincidence  in  structure  of  the  dorsal  side  of 
both  male  and  female  receptacles  with  that  of  the  corresponding  side 
of  the  sterile  part  of  the  thallus ;  (2)  the  altogether  similar  dorsi- 
ventral  development  of  the  pedicels  to  that  of  the  thallus ;  (3)  the 
aerial  layer  and  stomata  which  continue  without  interru])tion  from 
the  thallus  to  tlie  pedicels ;  and  (4)  the  ventral  or  radical  channels  of 
the  pedicel  w'ith  their  scales,  which  must  certainly  be  regarded  as  the 
equivalent  of  the  ventral  side  of  a  portion  of  the  thallus. 

In  an  exhaustive  treatise  on  the  subject,  Leitgeb  maintains  that 
the  attempt  to  apply  this  explanation  to  all  the  remaining  genera  of 
Marchantiacea)  with  the  exception  of  Targionia,  and  to  regard  all  male 
and  female  receptacles  as  resulting  from  the  transformation  of  a 
branch,  is  certainly  inadmissable  as  regards  most  male  inflorescences, 
and  is  justified  only  for  a  portion  of  the  female. 

Leitgeb  maintains  that  tlie  Marchantiaceae  arc  descended  from 
Riccia-likc  forms,  and  that  they  and  the  Ricciea)  belong  without 
doubt  to  one  and  the  same  series  of  development.  The  following  are 
the  most  important  points  relating  to  the  develoiiment  and  position  of 
the  reproductive  organs  of  the  Iticciea) : — 

1.  Both  kinds  of  sexual  organs  have  their  origin  immediately 
behind  the  growing  apex.  Henco  they  invariably  stand  on  the  dorsal 
side  next  the  median  line  of  the  thallus,  on  the  mid-rib,  and  are 
developed  in  acropetal  succession  ;  new  organs  never  being  formed 
further  from  tlie  apex  tlian  those  already  in  existence. 

2.  The  mother-cells  of  the  sexual  organs  at  first  project  like 
papilla)  al)ovo  tlio  surface ;  in  conseciucncc  of  the  increase  in  thick- 
ness of  the  thallus,  they  subsequently  ajjpcar  as  if  imbedded  in  the 
tissue. 

*     Si;,  k.  Akad    \Vi.-^s.  Wini,'  Ixxxi.  (1880)  |  p.  12:5-13. 

3  u  2 


992  RECORD   OF   CURRENT   RESEARCHES   RELATING   TO 

lu  these  points  the  RicciesB  agree  with  the  Marchantiaceaj.  The 
following  relate  to  the  variety  in  the  development  of  the  branches  or 
portions  of  the  thallus  which  bear  the  sexual  organs. 

3.  The  sexual  organs  of  some  species  are  associated  in  more  or 
less  sharply  defined  groups  (inflorescences). 

4.  On  their  formation  the  growth  of  the  apex  is  modified  in 
various  ways. 

The  following  are  described  by  the  author  as  the  different  types  of 
develoi)ment  of  the  male  and  female  inflorescences  of  the  Marchan- 
tiacece. 

1.  The  sexual  organs  are  scattered  over  the  surface  of  the  thallus; 
apical  growth  does  not  appear  to  be  modified  by  their  production. 
To  this  tyi^e  belong  the  true  Riccieas  $  and  9  ;  also  Clevea  (Sauteria) 
$  ;  apjjarently  also  BoscMa  ^ . 

2.  The  sexual  organs  are  congregated  in  groups  (inflorescences) 
recurring  on  the  same  axis  ;  where  receptacles  occur,  these  are  there- 
fore purely  dorsal  stnactures : — Corsinia  ^  and  9  j  Pkigiochasma, 
Fimhriaria,  Hehoulia,  Grimaldia,  Sauteria  (Peltolepis)  $  ;  with 
formation  of  true  female  receptacles  : — Plagiochasma,  Clevea  9  . 

3.  The  inflorescences  are  also  dorsal  structures,  but  are  placed  at 
the  apex  of  an  unbranched  shoot : — Duvcdlia,  Lunularia  ^  ;  Targionia, 
Cyathodium  $  and  9  j  with  formation  of  a  true  female  receptacle, 
from  the  enclosing  of  the  apex  of  the  axis : — Duvcdlia,  Heboulia, 
Fimhriaria,  Grimaldia. 

4.  The  inflorescences  correspoud  to  an  entire  branch-system  : 
Lunularia  9  ;  Fegatella  ^  ;  Marcliantia  and  Preissia  ^  and  9  • 

The  following  is  the  course  of  develoi^ment  of  the  sexual  organs  in 
the  Marchantiacese  :  —  At  first  distributed  over  the  surface  of  the 
thallus,  they  subsequently  arise  in  groups,  and  become  combined  into 
inflorescences,  which,  having  at  first  a  dorsal  position,  are  constantly 
pushed  further  back  towards  the  apex  of  the  axis,  and  enclose  it  in 
their  growth,  and  thus  dorsal  inflorescences  are  converted  into  terminal. 
In  those  genera  which  dichotomize  freely,  the  formation  of  the  in- 
florescence commences  at  the  moment  of  branching  ;  and  thus  the 
entire  branch-system  aids  in  the  formation  of  compound  inflorescences. 

In  conclusion,  the  author  states  that  the  same  course  of  develop- 
ment of  the  inflorescences  may  also  be  traced  in  the  Jungermanniaccfe ; 
and  that  it  is  highly  probable  that  the  same  is  true  also  of  the  Musci, 
notwithstanding  apparent  deviations. 

New  Hepaticae.* — The  following  new  and  critical  species  of 
Hepaticfe  are  described  by  Limj^richt : — Alicularia  Brcidleri,  Sarco- 
scyphus  confertus,  S.  commutatus,  and  Jungermannia  decolorans. 

Fungi. 

Observations  on  Uredinese  and  Ustilaginese.t — G.  Winter  con- 
tributes the  following  observations  to  our  knowledge  of  the  life- 
history  of  some  fungi  belonging  to  these  two  families. 

*  'JB.  Schef.  Ges.  f.  vuteil.  Cultm-,' Iviii.  See  '  Bot.  Ceutralbl.,'  i.  (ISSO) 
p.  806. 

- 1  'Hedwiyia,'  xis.  (18S0)  p.  105. 


mVERTEBRATA,    CRYPTOOAMIA,    MICROSCOPY,    ETC.  993 

The  question  has  been  hitherto  in  debate  whether  Phragmidlum 
Las  an  ajciclio-form.  Fuckel  states  distinctly  that  no  fecidio-form  is 
kno\vn,  but  spermogonia ;  while  Schroter  describes  the  secidio- 
frnctification  as  similar  to  the  uredospores ;  but  without  paraphyses. 
The  author  considers  it  possible,  from  his  observations,  that  Cceoma 
miniatum  and  its  allies,  which  are  found  abundantly  on  Buhus  and 
other  rosaceous  genera,  are  the  hitherto  undiscovered  aecidio-form  of 
Phraginidium. 

The  a3cidio-form  of  both  species  of  Puccinia  which  are  parasitic 
on  Caltlia  are  now  known,  and  are  developed  on  the  same  hosts.  The 
following  is  their  diagnosis : — Puccinia  Caltlice  Link.  iEcidium 
maculas  in  foliorum  pagina  sujieriore  luteas,  dein  fuseas,  irregulariter 
rotundas  vel  elongatas,  interdum  confluentcs,  in  pagina  inferioro 
tuborculatas,  1-5  mm.  longas  formans.  Ad  petiolura  calla  elongata, 
ca.  G  mm.  Lmga  adsunt.  Pscudoperidia  irregulariter  vel  rarius 
concentrice  disposita,  patellajformia,  parum  emersa,  marginc  lato 
revoluto  multum  inciso  albcscente  praidita.  Pseudoperidiorum  cellulfe 
polygoniaa  rotundatai  v.  clongatfe,  hyalinae,  niembrana  crassa,  verru- 
cosa, 22-35  /x  diam.  usque  45  rarius  60/ilongfe.  Sporfe  subrotundse, 
plenimque  polygonige,  aurantiaca3,  verruculosa3,  22-30  /x  diam. — Puc- 
cinia Zopfii  Winter.  iEcidium  ab  antecedente  margine  pseudo- 
peridiorum parum  iuciso,  laciniis  latis  ca.  4-5  prasdito ;  ad  pctiolum 
calla  usque  15  mm.  longa,  sfepc  confluentia  adsunt. 

The  author  also  records  the  detection  of  the  aecidinm  on  Mul- 
gedium  alinnum  which  belongs  to  Puccinia  PrenantJiis,  and  of  a 
Puccinia  on  Senecio  cordatus  apparently  identical  with  the  P.  con- 
gJomeraia  on  Homogyne  alpina. 

The  same  paper  contains  also  other  interesting  observations  on 
particular  species  belonging  to  this  group. 

Uredo  viticida.* — For  about  the  last  ten  years  the  vineyards  of 
Yonno  have  been  devastated  by  a  disease,  somewhat  similar  to  that 
produced  by  the  oidium,  which  as  completely  destroys  tho  grape  as 
docs  the  phylloxera  ;  but  tho  distribution  of  the  disease  is  much  more 
limited.  M.  Daille  has  examined  all  the  parts  of  the  plant  attacked, 
and  establishes  as  tho  cause  of  the  disease  a  fungus,  Urcdo  viticida, 
mainly  distinguished  from  oidium  by  its  spherical  spores,  and 
possessing  a  great  similarity  to  the  mildew  of  cereal  crops. 

Development  of  the  Spermogonia  of  .fficidiomycetes-t— An  ex- 
amination by  E.  Iviithay  of  the  spermogonia  of  a  considerable  number 
of  TEcidiomycetes — Puccinia  Anemones,  ohtcgens,  Falcariir,  Tragopo- 
gonis,  graminis,  straminifi,  and  comnata,  Gymnnspnrangium  fuscum, 
conicu7n,  and  clavaria^fnrtnc,  Uromyccs  acutellatiis,  and  JEcidium  Magcl- 
haenicum  and  CIcmatiilis — shows  that  in  almost  all  cases  they  contain 
a  larger  or  smaller  quantity  of  a  substance  which  has  tho  property  of 

•  •  Journ.  Pliarm,  ct  Cliiin.,'  ii.  (1880)  p.  32.  Seo  '  Bot.  Coiitralbl.,'  i.  (1880) 
p.  712. 

t  *Vorpel.  k.  Aknd.  Wiss.  Wien  ;  Sitz.  mftth.-nnturw.  CI..'  June  10,  mso. 
Bee  *  Bot.  Centralhl.,'  i.  (1S«0)  p.  flfil. 


994  RECORD    OF    CURRENT   RESEARCHES   RELATING    TO 

reducing,  with  the  assistance  of  heat,  Fehling's  reagent.  Since  the 
contents  of  the  spermogonia  of  Gymnosporangium  fusciim  and  conicum, 
which  contain  the  greatest  quantity  of  this  substance,  have  a  strong 
sweet  taste,  Eathay  believes  it  to  be  sugar. 

The  part  of  the  host  where  the  sugar-producing  spermogonia  of 
the  iEcidiomycetes  are  produced,  is  distinguished  for  a  considerable 
distance  around.  Thus,  in  the  case  of  the  ^cidiomycetes  with  mono- 
carpous  mycelium,  the  small  part  of  the  host  which  is  possessed 
by  the  mycelium,  and  on  which  the  comparatively  few  spermogonia 
make  their  appearance,  is  marked  by  a  remarkably  bright  yellow, 
orange,  or  red  colour.  And  in  the  case  of  those  with  pleocarpons 
mycelium,  in  which  an  entire  branch  of  the  host  is  infected,  and  the 
spermogonia  are  numerous,  breaking  out  either  on  all  the  organs  of 
the  infected  branch  or  only  on  the  leaves,  these  infected  branches  are 
doubly  distinguished  from  the  rest ;  firstly,  by  their  jieculiar  appear- 
ance, due  either  to  the  pale  colour  of  their  green  parts,  and  the  unusual 
form  of  their  leaves  (like  the  shoots  of  Cirsium  arvense  attacked  by 
Puccinia  ohtegens),  or  especially  to  their  abnormally  abundant  branch- 
ing and  leafiness  (like  the  "  witch-broom  "  of  the  berberry  caused  by 
JEcidium  Magelhaenicum),  or  to  the  suppression  of  the  flowers  (like 
the  well-known  sterile  branches  of  Euphorbia  cyparissias  attacked  by 
Uromyces  scutcllatus),  and  secondly  by  the  sweet  odour  springing  from 
the  spermogonia,  as  occurs  in  branches  affected  by  Puccinia  Anemones, 
ohtegens,  Falcarice,  and  Tragopogonis,  Uromyces  scutellatus,  and  ^cidium 
Magelhaenicum.  When  the  spermogonia  have  ceased  to  produce  sugar, 
their  colour  changes. 

In  damp  or  stormy  weather,  the  contents  of  the  spermogonia 
escape  from  their  mouths  in  the  form  of  small  drops  wbich  adhere  to 
the  paraphyses  ;  and  these  are  eagerly  sought  for  and  consumed  by 
various  insects,  such  as  ants  and  some  Coleoptera  and  Diptera  which 
are  capable  of  taking  up  honey  of  this  description,  such  as  the  honey- 
dew  formed  by  aphides,  the  nectar  of  extrafloral  nectaries,  the  honey- 
dew  of  ergot,  &c. 

The  author  draws  a  comparison  between  the  phenomena  connected 
with  these  male  organs  of  the  ^cidiomycetes,  and  the  well-known 
ones  associated  with  the  flowers  of  flowering  plants. 

Infection  of  Puccinia  Malvacearum.* — By  experiments  carried 
on  in  the  botanic  garden  at  Giessen,  Dr.  Ihne  confirms  the  previous 
statements  of  Cornu  and  Kellermann  that  this  fungus  can  be  pro- 
pagated by  direct  infection  on  leaves  of  the  same  plant  as  that  from 
which  it  was  obtained,  or  of  some  other  malvaceous  species.  The 
only  plant  on  which  the  parasite  made  its  appearance  this  year  at 
Giessen  was  the  hollyhock  {Althaea  rosea).  From  infected  leaves  it 
was  directly  conveyed  by  artificial  contact  to  others  on  hitherto  sound 
plants,  and  it  spread  also  by  spontaneous  infection.  Another  plant 
belonging  to  the  natural  order  Malvaceae,  Kitaihelia  vitifolia,  was  also 
infected  in  the  same  way ;  but  similar  experiments  on  Lavatera 
trimestris  were  unsuccessful. 

*  'Hedwigia,'  xix.  (1880)  pp.  137-8. 


mVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


995 


Alternation  of  Generations  in  Gymnosporangium.* — Oersted  lias 
already  sliowu  that  the  sporidia  of  Podisoma  sahince,  parasitic  on 
Juniperus  sabina,  sown  on  Pijrus  communis,  give  rise  to  Boestelia  can- 
cellata  ;  those  from  Podisoma  jimiiyerinum,  parasitic  on  Juniperus  com- 
munis, to  Boestelia  cornuta  when  sown  on  Sorbus  aucuparia ;  and  those 
of  Podisoma  clavariceforme,  parasitic  on  J.  communis,  to  Boestelia 
lacerata  when  sown  on  Crakegus  oxyacantha,  and  to  B.  penicillata  on 
Pyrus  Malus  (this  last  is,  however,  believed  by  the  present  writer  to 
be  an  error). 

A  long  scries  of  experiments,  conducted  by  Dr.  E.  Rathay,  have 
led  him  to  the  conclusion  that: — 1.  The  Podisoma  sabincB  on  Juniperus 
sabina,  and  the  Boestelia  cancellata  on  Pyrus  communis,  belong  to  the 
same  species.  2.  Tlie  Boestelia  cornuta  on  Sorbus  aucuparia  belongs 
to  the  Podisoma  juniperinum  on  JunijJerus  communis  ;  and  that,  contrary 
to  expectation,  to  the  same  teleuto-form  belong  also  the  Boestelia 
penicillata  on  Pyrus  3Ialus  and  Sorbus  Aria,  and  the  Boestelia  on 
Cydonia  vulgaris.  3.  The  Podisoma  clavariceforme  on  Juniperus  com- 
munis, the  Boestelia  lacerata  on  Cratcegus  oxyacantha  and  monogyna, 
and  a  distinct  Boestelia  found  by  the  writer  on  Pyrus  communis,  and 
another  on  Sorbus  torminalis,  all  belong  to  the  same  species.  4.  No 
result  followed  from  sowing  the  sporidia  of  Podisoma  sabince  on 
Mespilus  germanica,  Cratcegus  oxyacantha,  G.  monogyna,  Pyrus  Malus, 
Sorbus  Aria,  or  S.  torminalis  ;  or  those  of  P.  juniperinum  on  Mespilus 
germanica,  Cratcegus  oxyacantha,  C.  monogyna,  Sorbus  domestiea,  or 
S.  torminalis ;  or  those  of  P.  clavariceforme  on  Mespilus  germanica, 
Pyrus  Malus,  Sorbus  domestiea,  or  S.  Aria. 

In  order  to  simplify  the  nomenclature,  Oersted  united  these  series 
of  teleuto-forms  and  fecidio-forms  into  the  genus  Gymnosporangium  ; 
and  to  the  three  species  occurring  in  Denmark  he  gave  the  names 
G.  fuscum,  conicum,  and  clavariceforme,  corresponding  to  the  teleuto- 
forms  Podisoma  sabince,  juniperinum,  and  clavariceforme. 

E.  Eathay  states  that  the  teleutospores  of  P.  clavariceforme  are 
mature  earlier  than  those  of  P.  sabince  and  juniperinum  ;  and  that  the 
same  is  the  case  with  regard  to  tlie  maturity  of  the  sperraogonia  and 
ajcidia  of  tlio  corresponding  aicidio-forms.  He  gives  the  following 
table  of  all  the  species  on  which  both  forms  of  the  three  species  have 
at  present  been  found  to  be  parasitic  : — 

Hosts  of  Teleuto-form.      Hosts  op  .^cidio-form. 


GijTnnosporanguiin  fuscitm   I   Juniperus  sahini  L. 

DC,  Oerst.  | 

Gymnosporangium  conicum       Juniperus  communis  L. 

DC,  Oerst. 


Gymnos^pornntiium     cinvn- 
riivfurmc  DC,  Oerst. 


Jnniprrnx  communis  L 


Pyrw?  communis  L. 

Sorbus  aucuparia  L. 
Aronia  rotuwlifolia  Pcr.s. 
Pyrus  Malus  Tj. 
Sorbus  Aria  Crtz. 
Cydonia  vulgaris  Pcr.s. 

Cratwgus  oxyacantha  L. 
Crata:g>is  mono<jyiM  Jac4]. 
Pyrus  communis  L. 
Sorbus  tonninalis  Crtz. 


*  *Oestcrr.  Dot.  Zeitr^clir..'  xxx.  (1880)  pp.  211-4. 


996      RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

Conidial  Apparatus  of  Pleurotus  ostreatus.* — Specimens  of  this 
fungus  gathered  in  the  woods  of  Meudon  on  Feb.  1st  last,  exhibited 
the  following  peculiarities  of  structure. 

The  development  of  these  specimens  had  taken  place  under 
unfavourable  conditions,  in  consequence  of  the  severe  cold  of  January, 
which  caused  such  an  exuberant  growth  of  the  capiHary  system  that 
the  fungus,  which  ordinarily  possesses  only  short  hairs,  and  these 
usually  very  few,  on  the  pileus  and  the  stipes,  was  entirely  covered 
with  a  dense  white  down. 

The  hairs  which  constituted  this  down  were  composed  of  two  or 
three  cells  with  granular  contents  and  witli  a  swelling  at  each  articu- 
lation. The  hairs  were  ordinarily  distinct ;  but  sometimes  two  or 
three  had  coalesced  either  at  the  apex  or  at  the  point  of  contact  of 
two  lateral  walls,  or  finally  by  means  of  a  kind  of  bridge. 

The  hairs  on  the  centre  of  the  pileus  and  on  the  stipes  appeared 
to  be  always  sterile,  while  those  on  the  edge  of  the  pileus  were  shorter 
and  often  sporiferous.  These  spores  are  ovoid,  colourless,  thin-walled, 
and  contain  one  or  two  vacuoles ;  they  are  borne  on  a  short  sterigma. 
Each  hair  bore  one  or  two  spores,  but  there  was  never  more  than  one 
attached  to  a  single  cell.  The  spore  might  be  exactly  terminal,  or 
near  the  summit,  or  altogether  lateral. 

The  fertile  basidia  appeared  to  be  less  abundant  than  usual  in 
these  specimens. 

Ptychogaster  albus,  Cord.,  a  Form  of  a  Polyporus.f  —  This 
fungus  has  been  variously  assigned  to  the  Myxomycetes,  Gastero- 
mycetes,  and  Hymenomycetes ;  and  has  been  considered  as  a  stage  of 
development  of  another  fungus.  T.  Ludwig  has  now  set  the  question 
at  rest  by  the  discovery  of  a  second  mode  of  fructification. 

On  the  entire  under  side  or  on  free  spots  of  it,  it  sometimes  forms 
PolyjJorus-tnhes,  or  the  hyph^e  display  an  evident  tendency  to  collect 
into  tubes.  Sections  through  the  fungus  do  not  bring  out,  even  under 
the  Microscope,  any  diiference  between  this  layer  and  the  rest ;  both 
consist  of  similar  hyphfe.  The  PoZ//porMS  tubes  are  of  moderate  size 
with  angular  or  roundish  mouth,  where  they  have  a  few  sharp  teeth, 
the  extremities  of  hyphfe  which  project  beyond  the  mouth. 

On  the  spots  inhabited  by  the  Ptychogctster  no  other  species  of 
Polyporus  was  found.  Ludwig  regards  it  therefore  as  an  independent 
and  new  species,  most  often  propagated  by  conidia  and  but  rarely  by 
the  Po?//|>ori<s-fructification,  and  describes  it  under  the  name  Polyporus 
Ptycliog aster.  The  phenomenon  is  analogous  to  that  in  Fistulina 
hepatica,  in  which  De  Seynes  discovered  a  conidial  generation,  as  did 
Eidam  and  Van  Tieghem  in  some  species  of  Coprinus. 

Synchytrium  parasitic  upon  Dryas.| — Dr.  F.  Thonia,s  records 
the  discovery,  in  the  Tyrolean  Dolomites,  of  a  parasitic  fungus 
forming  galls  on  the  leaves  of  Dryas  odopetala,  which  he  identities 

*  '  Bull.  Soc.  Bot.  France,'  xxvii.  (1880)  p.  125. 

t  '  Zeitschr.  fiir  d.  Ges.  Natur,'  1880,  p.  424.  See  '  Bot.  Centralbl.,'  i.  (1880) 
p.  865. 

.%  '  Bot.  Centralbl.,'  i.  (1880)  p.  703. 


INVERTEBRATA,    CRYPTOGAM  [A,    MICROSCOPY,    ETC.  997 

with  Synchytnum  Myosotidis,  Kuebn,  distinguisliing  it  as  the  var. 
Dryadis.  The  spherical,  ovoid,  or  flask-shaped  cells  which  conceal 
the  parasite  resemble  large  golden-yellow  or  reddish-yellow  glands 
emerging  above  the  epidermal  layer ;  they  arc  more  abundant  on  the 
upper  than  the  under  surface,  often  so  closely  packed  as  to  form  a 
kind  of  incrustation ;  they  also  occur  on  the  leaf-stalks,  stipules,  and 
sepals,  less  often  on  the  flower-stalks.  Each  of  these  abnormally 
swollen  cells  contains  one,  or  less  often  two  spores.  The  tissue  of 
the  infected  leaf  undergoes  the  ordinary  hypertrophy. 

New  Vine-disease.* — Under  the  name  "  Herbstbrenner  "  Dr. 
Kfibler  describes  a  disease  of  the  vine  which  shows  itself  in  the  rapid 
fall  of  the  leaves,  resulting  from  warm  sunshine  after  a  cold  autumn 
rain,  causing  some  of  the  cells  of  the  leaves  to  burst,  and  the  fluid 
contents  to  flow  into  the  intercellular  spacoSj  and  there  decompose. 
The  products  of  decomposition  give  rise  to  a  fungus  which  develops 
with  great  rapidity  into  brown  tufts  on  the  upper  surface  of  the  leaf; 
and  entire  vineyards  lose  their  leaves  in  a  few  days.  The  fungus 
consists  of  a  white  mycelium  with  fertile  threads  which  bear  bilocular 
spores  grouped  in  tufts.  The  author  proposes  for  it  the  name  Clado- 
sporium  autumnale. 

With  regard  to  O'idium  Tuckeri  and  Sphaceloma  ampelinum,  Dr. 
Kiibler  considers  that  they  are  not  the  causes  of  the  well-known  vine- 
diseases,  but  the  result  of  unhealthy  conditions  of  soil,  climate,  &c. 

Pfau-Schellenberg  disputes  this  last  conclusion  of  Kiibler;  but 
confirms  his  observations  with  regard  to  the  Cladosporium  autumnale. 

Clover-disease  in  Sweden.f — A  very  destructive  disease  first  made 
its  appearance  on  the  clover-crops  in  Hesse  in  1857,  since  spreading 
into  Denmark  and  Sweden.  Its  histoi-y  and  cause  have  been  closely 
investigated  by  J.  Eriksson,  who  attributes  it,  as  previous  observers 
have  done,  to  the  ravages  of  a  parasitic  fungus.  He  does  not,  how- 
ever, agree  with  H.  Hoflhiann,  in  identifying  the  parasite  with  Peziza 
cihoroides  Fr.,  from  which  it  diti'ers  both  in  the  time  of  year  at  which 
it  appears,  and  in  other  respects.  The  writer  proposes  for  it  the  name 
Peziza  {Sdcrotinia)  trifdUoruiu,  and  considers  it  nearly  allied  to  S. 
Jwmocarjia  Karst.  The  form  in  which  the  fungus  attacks  the  clover 
is  that  of  a  sclerotium  ;  but  its  propagation  the  writer  considers  duo 
to  hyjjhaj  which  become  attached  to  the  clover-seeds. 

Salmon  Disease.t — The  subject  of  the  salmon  disease  still  occupies 
the  attention  of  the  Fishery  Commissioners,  and  a  jiaper  on  the 
subject  has  been  read  at  the  Dumfriesshire  Natural  Histt)ry  Society, 
in  which  it  is  maintained  that  tho  disease  is  aggravated,  if  not  caused, 
by  the  presence  of  a  vast  number  of  Bacteria  in  the  flesh  of  tho 
diseased  spots. 

Mr.  Eutlicrford  writes  : — "  Sccticms  of  tho  muscle,  when  placed 
under  tho  Microscope,  wore  seen  to  be  literally  one  mass  of  life  ;  that 

*  '  Arch.  Sci.  i)liy.s.  et  n;it.  Goiiove,'  1879,  p.  loG.  Soo  '  Bot.  Contralbl.,'  i. 
(1S80)  p.  2'.J8. 

t  '  K.  Svcnsk.  Laiultbr.  Akad.  Hiindl.  och  Tiddskr.,'  1880.  Sco  '  Bot. 
Centmlbl.,'  i.  (1880)  p.  2'.»(1. 

X  '(jirrvilUa,"  ix.  (1880)  pp.  0-10. 


998  RECORD   OP   CURRENT   RESEARCHES   RELATING    TO 

life  being  a  species  of  Bacteria.  They  are  small  discoid-looking 
bodies,  which  in  this  case  I  find  imbedded  in,  and  moving  amongst, 
the  striated  muscle-fibre  of  the  fish,  and  when,  by  pressure  or  other- 
wise, they  are  forced  into  the  surrounding  fluid,  they  have  a  power  of 
motion,  moving  mostly  in  a  sort  of  circular  direction.  In  some  fish  that 
I  have  examined,  I  observed  that  the  muscle  was  almost  detached  from 
the  strong  fibro-muscle  layer  of  the  skin,  and  the  muscle  fibres  of  that 
layer  were  not  adhering  together  as  in  their  natural  state,  and  could 
be  separated  from  each  other  like  threads  by  the  needle.  Whether 
that  diseased  condition  of  that  part  of  the  skin  was  caused  by  the 
muscle  immediately  below  it,  or  by  the  fungus  on  the  surface,  I  am 
not  in  a  position  to  say."  Afterwards  he  says  : — "  The  disease  was 
located  in  the  muscle  of  the  fish,  and  I  also  have  some  idea  that  it 
will  be  found  to  commence  in  the  blood,  caused  either  by  the  food 
they  eat,  or  by  some  deleterious  solution  in  the  water  which  passes 
through  the  gills ;  and  that  the  unhealthy  decaying  fluid  or  matter 
which  will  naturally  pass  off  from  those  Bacteria,  and  exude  through 
the  pores  of  the  skin,  forms  a  healthy  and  proper  nidus  for  the  ger- 
mination of  the  zoospores  of  the  fungus,  which  must  be  in  those  affected 
rivers  in  myriads." 

It  would  be  some  consolation  to  the  mycologist  if,  after  all,  he 
could  feel  convinced  that  this  fatal  salmon  disease  was  not  primarily 
caused  by  the  Saprolegyiia ;  but  Dr.  M.  C.  Cooke  considers  that 
"  there  are  very  grave  doubts  whether  these  Bacteria  are  not  more 
probably  the  result  of  a  certain  disintegration  of  the  substance  of  the 
flesh  caused  by  the  mycelium  of  the  Sajprolegnia,  than  a  preliminary 
depravity  of  the  flesh  inducing  the  subsequent  development  of  the 
fungus.  However  much  we  may  dislike  the  conclusion  that  a  fungus 
is  the  principal  cause  of  so  much  mischief,  I  fear  that  we  must  accept 
the  force  of  evidence  which  goes  to  show  that  the  Saprolegnia  appears 
to  be  the  great  destructive  agent  in  this  disease.  It  may  be  true,  and 
undoubtedly  is,  that  the  constitution  of  the  fish  is  in  a  low  condition, 
that  it  is  debilitated,  and  powerless  to  resist  the  fungoid  attacks ;  and 
that  this  condition  may  be  the  result  of  various  secondary  causes ; 
but  the  theory  that  Bacteria  in  the  fish  is  the  primary  cause,  though 
it  may  be  a  new  suggestion,  can  scarcely  be  accepted  as  a  true  one. 
The  coincidence  should  be  borne  in  mind,  even  if  it  is  no  more  than 
a  coincidence,  that  in  all  the  great  instances  of  devastating  fungal 
diseases,  there  has  been  an  undoubtedly  weakened  constitution  in  the 
subject,  caused  by  over-cultivation,  and  in-breeding,  preliminary  to 
the  attacks.  Such  was  the  case  with  the  silkworm,  and  it  fell  a  prey 
to  '  muscardine ' ;  in  the  potato,  and  it  succumbed  to  the  Peronospora  ; 
in  the  vine,  and  it  became  the  victim  to  Oidium.  May  we  not  add 
also,  in  the  salmon,  ere  it  was  devastated  by  the  Saprolegnia  ?  and  it 
may  yet  be  to  the  onion  in  Europe,  and  the  poppy  in  India,  unless 
the  threatened  misfortune  should  be  averted." 

Biology  of  the  Schizomycetes.* — H.  v.  Boehlendorff  has  applied 
Bucholtz's  method  of  investigating  the  life-history  of  the  Schizomy- 

*  Bnehlendoi-ff,  H.  v.,  '  Ein  Beitrag  zur  Biologie  einiger  Scliizomyceten. 
Inaug.-Dissert.'    Dorpat,  1880.     See  '  Bot.  Centralbl.,'  i.  (1880)  p.  692. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  999 

cetes,  especially  to  the  albumen-bacteria.  The  luitrient  fluid  employed 
was  hard-boiled  white  of  egg  pounded  in  a  mortar  and  then  boiled 
for  an  hour.  The  milky  fluid  thus  obtained  was  preserved  free  from 
bacteria  for  weeks  by  a  carbol-wad.  In  order  to  obtain  the  bacteria, 
he  allowed  a  small,  clean,  strongly-heated  glass,  into  which  a  small 
quantity  of  the  fluid  had  been  poured,  to  stand  exposed.  In  the 
space  of  twenty-four  houi's,  numerous  rods  had  made  their  appearance 
in  it ;  the  sulphuretted  hydrogen  reaction  set  up  from  five  to  eight 
days  later.  The  progressive  development  of  the  bacteria  was 
observed  partly  in  the  decoction  of  albumen  placed  in  a  hatching- 
oven,  partly  in  solutions  of  albumen  infected  with  fresh  bacteria,  and 
protected  by  a  wad-stopper,  also  placed  in  the  hatching-oven. 

On  the  first  day  there  were  seen  only  small  motile  spherules  and 
rods ;  on  the  following  days  the  rods  had  increased  in  size,  the 
spherules  had  disappeared.  The  rods  were  partly  free  and  motile, 
partly  collected  into  zoogkea-colonies.  The  sulphuretted  hydrogen 
reaction  began  with  the  formation  of  zoogloea,  increased  for  five  or 
ten  days,  and  tlien  again  decreased.  As  this  evolution  increased,  the 
zooglosa-colonies  again  always  dispersed,  and  the  rods  gradually 
disappeared,  breaking  up  into  strongly  refractive  spherules.  When 
the  evolution  had  ceased,  the  spherules  often  again  grew  into  rods,  and 
the  development  began  afresh.  There  was  a  difference  in  the  result 
according  as  fresh  albumen-bacteria  or  bacteria  from  a  solution  in 
which  sulphuretted  hydrogen  had  already  begun  to  be  produced,  were 
placed  in  the  albumen-decoction.  In  the  latter  case  the  sulphuretted 
hydrogen  reaction  was  manifested  on  the  second  day,  in  the  former 
generally  not  till  the  fifth.  In  two  cultures,  bacteria  from  a  fresh 
solution  containing  no  suli>huretted  hydrogen,  and  secondly  from  one 
in  which  the  gas  was  being  abundantly  developed,  and  in  which  there 
were  already  a  niimber  of  rods,  were  sown  in  boiled  and  unboiled 
milk,  in  boiled  urine,  and  in  a  decoction  of  ergot. 

It  was  now  seen  that  the  stage  of  development  of  the  bacteria 
influenced  the  process  of  decomposition  in  the  new  nutrient  fluid. 
The  young  bacteria  merely  turned  the  milk  sour  or  somewhat 
accelerated  the  acidity  ;  the  more  vigorous  old  bacteria,  which  had 
already  caused  a  production  of  sulphuretted  hydrogen  in  the  albumen- 
solntion,  produced  the  same  reaction  in  the  fluid ;  they  continued  to 
develop,  while  tlie  young  bacteria  were  more  indiflerent,  or  altogether 
perished.  In  fresh  milk  no  eficct  was  produced  ;  the  natural  ferment 
acted  quicker  and  more  strongly.  In  urine  the  older  bacteria  always 
produced  alkalinity  more  rapidly  than  the  younger  ones  ;  in  ergot- 
decoction  both  soon  perished.  Ho  also  introduced  the  bacteria  from 
putrefying  blood,  tobacco-  and  pea-decoction  into  a  great  variety  of 
nutrient  fluids. 

The  general  results  arrived  at  were  that  (1)  the  Schizoraycctes 
from  the  same  generating  substances,  when  introduced  into  different 
nutrient  fluids,  present  great  variation  in  their  development  ;  and  (2) 
Schizomycetes  from  diflerent  generating  substances,  introduced  into 
one  and  the  same  nutrient  fluid,  also  develop  ditferently,  and  in  part 
produce    also    different  decompositions;    and    hence   that   both    the 


1000  RECORD    OF    CURRENT   RESEARCHES    RELATING   TO 

generating  substance  and  the  nutrient  fluid  influence  the  growth  and 
the  vigour  of  bacteria. 

Further  experiments  were  made  by  the  author  with  the  bacteria 
of  sour  milk.  He  found  in  it  the  sphasro-bacteria  described  by 
Pasteur,  whose  developments  he  followed  out.  Sowings  in  different 
nutrient  fluids  also  produced  a  more  or  less  abundant  growth  of  them. 
In  boiled  urine  they  developed  with  especial  vigour ;  but  after  a 
fortnight  the  alkaline  fermentation  was  not  produced ;  while  by  the 
bacteria  of  urine  it  was  brought  about  in  a  few  days.  In  urine  there 
arose  spontaneously  at  first  small  spherules,  succeeded  by  small  rods, 
which  at  length  developed  into  long  filaments  and  vibrios.  The 
experiments  made  with  these  urine-bacteria,  which  he  placed  in  the 
most  various  nutrient  fluids,  gave  very  diiferent  and  partially 
irreconcilable  results,  so  that  the  author  was  led  to  the  conclusion 
that  a  variety  of  bacteria  arise  spontaneously  in  urine,  one  of  which 
often  smothers  another. 

Finally,  he  followed  the  development  of  bacteria-sowings  from 
various  generating  substances  in  unboiled  flesh  -  water  and  in 
Bucholtz's  fluid,  in  boiled  flesh-water,  solution  of  peptone,  and 
solution  of  isinglass.  Tho  peptone-solution,  which  he  strongly 
recommends  for  bacteria-culture,  he  made  of  0  •  08  gr.  pepsin,  4  cc. 
33  per  cent,  hydrochloric  acid,  and  20  gr.  fibrin  in  400  cc.  distilled 
water,  leaving  the  mixture  some  hours  in  a  warm  place  until  the 
fibrin  was  dissolved,  the  solution  then  neutralized  with  ammonia, 
filtered,  and  finally  sterilized  by  boiling.  The  solution,  which  is  at 
first  turbid,  soon  becomes  perfectly  clear  from  an  abiindant  white 
precipitate  of  parapeptone  ;  and  the  presence  of  bacteria  can  then  be 
recognized  without  the  Microscope  by  the  turbidity  which  always 
again  results. 

The  following  are  given  by  the  author  as  the  most  important 
results  obtained  : — 

1.  He  believes  in  the  existence  of  a  number  of  different  species  of 
bacteria. 

2.  He  considers  the  fact  that  no  development  takes  place  in 
Bucholtz's  solution  to  be  no  proof  that  active  bacteria  and  bacterial 
germs  are  not  present  in  a  sowing. 

3.  Sphfero-bacteria  are  partly  indcj^endcnt  forms,  partly  stages  of 
development  of  bacillar  bacteria. 

4.  The  spontaneous  infection  of  the  nutrient  fluid  usually  takes 
place  from  the  access  of  spores  from  tho  atmosphere,  and  not  from  the 
water  used  in  the  fluid. 

5.  The  final  results  of  the  development  of  bacteria  are  strongly 
refractive,  longish  oval  resting-spores. 

6.  The  nutrient  fluid  employed  is  not  a  matter  of  indifiPerence. 

Influence  of  Schizomycetes  on  the  Development  of  Yeast.* — 
According  to  experiments  carried  on  by  M.  Hayduck,  the  presence  of 
Schizomycetes  exercises  an  injurious  influence  on  the  propagation  of 
yeast  and  the  process  of  fermentation.     The  cause  is  probably  simply 

*  'Zeitschr.  f.  Spiritusindustric,'  iii.  (18S0)  p.  202.  See  '  Bot.  Centralbl.,'  i. 
(1880)  p.  866. 


INVEKTEBRATAj    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1001 

that  the  former  remove  from  the  nutrient  fluid  the  substances  which 
serve  for  the  nutrition  of  the  latter.  On  fully  developed  torula-cells 
they  appear  to  have  no  injurious  influence. 

New  Microscopic  Schizomycetes.* — V.  A.  Poulsen  describes  an 
organism  discovered  by  him  belonging  to  the  family  Sarcinepe  of 
Schizomycetes,  which  he  treats  as  a  new  genus  and  species  under  the 
name  Sarcinoglobulus  pundum.  It  diflers  from  the  genus  Sarcina  in 
its  spherical  form  and  numerous  cells.  It  occurs  in  sea-slime  from 
which  sulphuretted  hydrogen  is  given  off.  In  similar  situations  he 
found  also  a  new  species  of  Sarcina,  S.  lUoralis. 

Chlami/domonas  hi/alina  Cohn  is  also  described  again  in  detail, 
and  the  old  name  C.  uva  restored. 

Social  Bacteria. f — M.  P.  Van  Tieghem  remarks  that  in  the 
family  of  Bacteriacefe,  the  cells,  whatever  their  form,  spherical, 
cylindrical,  or  spiral,  are  disposed  in  a  variety  of  ways.  Sometimes 
they  are  arranged  in  a  linear  series,  in  the  order  in  which  they  have 
inci'eased  or  divided,  so  as  to  form  long  threads  of  beads  [Micrococcus 
urece,  bomhicis,  &c.),  or  cylindrical  (Bacillas  anthracis,  the  young  state 
of  B.  amijlobacter,  &c.)  or  spiral  filaments  (Spirochiete),  This  is  the 
typical  disposition,  and  is  sometimes  modified  by  the  formation  of  a 
gelatinous  sheath  either  around  the  whole  mass  of  cells  ( Mi/conostoc), 
or  each  separate  cell  [Leuconostoc) ;  but  this  does  not  affect  the 
arrangement  of  the  cells  in  a  linear  series,  which  is  often  contorted 
and  knotted  on  itself. 

Sometimes,  on  the  contrary,  the  cells  separate  immediately  after 
segmentation,  without  preserving  any  mutual  relation  as  to  direction. 
Then  they  either  disperse  in  the  surrounding  medium  without  main- 
taining any  connection,  or  they  secrete  a  gelatinous  substance  which 
keeps  them  united  in  more  or  less  considerable  masses  altogether 
indeterminate  in  form  (several  species  of  Micrococcus,  Bacterium,  Sec). 

This  permanent  association  in  a  linear  series,  and  tliis  immediate 
dissociation  into  separate  cells,  present  various  connecting  links, 
which  render  the  chai'acters  diflicult  and  doubtful  of  applicati(jn  in 
the  definition  of  genera  and  species.  This  does  not  appear  to  be  the 
case  with  a  third  mode  of  existence,  which  the  author  terms  social 
(agrctjre). 

Under  these  conditions  the  cells,  spherical  or  rod-shaped,  become 
completely  dissociated  immediately  after  the  division  by  which  tliey 
have  been  formed,  turn  and  glide  one  over  another,  and  remain  in 
intimate  contact,  cemented  together  apparently  by  a  gelatinous 
substance.  Starting  from  a  spore  or  primitive  cell,  there  is  thus 
gradually  developed  a  compact  mass,  with  more  or  less  sharj)  out- 
lino,  which  soon  assumes  a  definite  form,  spherical,  oval,  or  cul)ical, 
and  which  increases  by  repeated  and  simultaneous  bipartition  of  tlic 
cells  of  which  it  is  composed.  When  it  has  attained  a  curtain 
dimension,  it  divides  into  two  equal  halves,  which  so^iarato  slightly, 

♦  PouUeii,  V.  A.,  '  Ucbcr  ciiiigo  niikroskopisclio  rilauzouorganisuicu.'  !Soc 
'  Bot.  Zfit.,'  xxxviii.  (lst<(i)  p.  50J. 

t  'Bull.  S.c.  But.  Fniucc.'sxvii.  (IS8U)  pp.  118-1.k!. 


1002  RECOKD    OF    CURRENT    RESEARCHES    RELATING    TO 

increase  so  as  to  resume  their  primitive  form,  and  then  in  their  turn 
divide  when  they  have  reached  their  full  size.  Sometimes  the  entire 
mass  is  naked  ;  its  contour  is  formed  simply  of  the  extremities  of  the 
peripheral  cells  which  are  bound  together  by  the  interstitial  gelatinous 
substance.  Sometimes,  on  the  contrary,  it  is  enveloped  by  a  resisting 
membrane  of  a  gelatinous  appearance,  which,  after  each  augmentation 
of  the  contents,  develops  between  the  two  halves,  and  then  divides  so 
as  to  clothe  them  completely  and  independently  after  their  separation. 

The  segmentation  of  the  entire  body  takes  place  either  in  one 
direction  only,  and  the  small  masses  remain,  at  least  for  a  time, 
united  like  bead-work,  or  in  two  directions  in  the  same  plane,  and 
the  masses  spread  out  side  by  side  in  the  form  of  a  membrane ;  or 
finally,  in  three  directions,  and  the  masses  are  superposed  in  a  solid 
mass,  and  form  nodules  of  a  smaller  or  larger  size. 

Thus  are  formed  aggregations  of  cells,  derived  from  one  primitive 
parent  cell,  and  following  henceforth  a  common  law ;  and  these  cells, 
in  their  form,  their  mode  of  increase,  their  successive  divisions,  and 
the  relations  which  they  maintain  towards  one  another,  behave  like 
so  many  simple  cells,  sometimes  naked,  sometimes  enveloped  in  a 
membrane.  They  constitute,  in  fact,  cells  of  a  second  order,  com- 
posite cells,  something  like  those  compound  bodies  which,  in  chemical 
combinations,  play  the  part  of  simj^le  bodies.  By  careful  crushing, 
these  colonies  can  be  decomposed  ;  when  the  isolated  cells,  continuing 
to  increase  as  when  they  formed  part  of  the  colony,  soon  again  con- 
stitute new  societies,  which  again  carry  on  their  normal  development. 

In  further  investigating  the  form  of  the  primitive  cells,  the  form 
of  the  colonies,  or  cells  of  the  second  order,  the  presence  or  absence 
of  a  general  membrane,  and  the  relative  disposition  of  the  colonies 
after  their  division,  characters  may  be  obtained  of  a  certain  number  of 
genera  and  species  ;  and  the  author  proceeds  briefly  to  define  the  types 
best  known  to  him,  and  the  development  of  which  he  has  been  able  to 
follow.  They  arrange  themselves  in  two  groups,  according  as  the 
colony  is  or  is  not  provided  with  an  enveloping  membrane. 

1.  Naked  Colonies. — The  colony  is  composed  either  of  cylindrical 
cells  similar  to  those  of  Bacterium  and  Bacillus,  or  of  spherical  cells 
similar  to  those  of  Micrococcus.  The  former  are  united  into  the 
genus  Polyhacteria,  the  latter  into  the  genus  Punctula. 

Polyhacieria. — In  the  decoction  of  horse-dung  which  is  frequently 
employed  for  the  production  of  fungi,  M.  Van  Tieghem  has  often  met 
with  a  Polyhacteria,  in  which  the  naked,  colourless,  oval  colonies, 
composed  of  small  rods  aggregated  in  every  variety  of  way,  always 
divide  transversely  in  the  same  direction,  and  remain  end  to  end  in  the 
form  of  a  frequently  sinuous  chain.  This  chain  proceeds  from  the 
increase  and  division  of  a  single  mass,  and  this  primitive  mass  is 
again  entirely  derived  from  a  spore  or  a  rod,  as  the  writer  has  many 
times  demonstrated  by  tracing  the  development  of  this  minute  organism 
in  cell  cultures,  which  is  not  unattended  with  difficulty.  It  may  be 
called  Polyhacteria  catenata. 

In  another  species  the  rods  are  of  a  sulphur-yellow  colour,  the 
colonics  rounded  or  polyhedral,  and  segmentation  takes  place  in  two 


IXVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1003 

directions  at  right  angles  to  one  another.  When  placing  themselves 
side  by  side  in  the  same  plane,  they  form  a  sort  of  membrane,  but 
without  adherence.  This  is  Polyhacteria  sulplmrea.  It  was  found  on 
the  surface  of  a  liquid  in  which  haricots  were  rotting. 

Pundula. — The  sj^herical  cells  are  ordinarily  extremely  minute  ; 
they  appear  like  innumerable  dots  united  by  a  gelatinous  cement. 
A  close  examination  is  required  to  distinguish  the  colonies  composed 
of  them  from  simple  naked  cells  consisting  of  a  finely  granular 
protoplasm. 

In  Pundula  rosea  the  colonies  are  of  a  bright  rose  colour ;  they 
are  spherical,  and  with  a  sharply  defined  outline  ;  the  dots,  which  are 
so  many  elementary  cells,  are  arranged  in  them  with  perfect  regularity 
in  radial  rows  and  concentric  circles.  After  each  division,  the  two 
halves  of  the  colony  become  rounded  off",  and  separate  completely. 
When  one  of  these  spheres  is  crushed,  it  is  resolved  into  its  elementary 
cells,  and  the  formation  can  then  be  followed  of  so  many  new  colonies 
by  the  repeated  increase  and  division  of  each  of  the  cells. 

In  Pundula  cuhica  the  slightly  larger  cells  are  colourless,  and  are 
associated  together  in  cubical  masses.  After  attaining  a  certain 
dimension  the  cube  divides  successively  in  directions  parallel  to  its 
three  faces,  and  each  new  cube  behaves  in  the  same  way.  At  least 
for  a  time,  all  the  cubes  arc  associated  together  in  larger  or  smaller 
cubical  masses. 

In  Pundula  glomerata  the  colourless  colonies  are  rounded  into 
spheres,  divide  in  three  directions,  and  remain  thenceforth  associated 
in  larger  or  smaller  mamillated  masses. 

These  three  organisms  have  been  found  at  various  times  on  seeds 
in  a  state  of  putrefaction. 

2.  Colonies  trovided  with  a  Membbane. — In  this  group  must  be 
placed  the  genus  Ascococcus  of  Cohn,  composed  of  spherical  cells, 
which  is  nothing  but  a  Pundula  invested.  The  types  with  cylindrical 
cells  may  bo  combined  into  the  genus  Ascohaderia,  which  again  may 
be  described  as  a  Pohjhaderla  invested. 

Ascohaderia. — On  the  surface  of  li(|uids  in  which  were  rotting  seeds 
of  various  leguminous  plants,  and  especially  lupine,  the  writer  fre- 
quently found  small,  granular,  polyhedral  masses,  each  enveloped  in 
a  thick  cartilaginous  membrane,  placed  side  by  side  in  a  strongly 
adherent  layer,  after  the  manner  of  an  Ulca.  But  the  contents  of 
each  compartment,  instead  of  being  a  simple  protoplasmic  body,  were 
composed  of  a  great  number  of  small  I'ods,  inclined  in  all  directions, 
and  intimately  united  by  a  kind  of  cement.  After  having  attained  a 
certain  dimension  by  repeated  and  sinniltaneous  bipartition  of  the  rods, 
it  splits  into  two,  and  tho  gelatinous  membrane  is  continued  over  the 
two  new  surfaces.  Wlien  the  mass  is  crushed,  the  rods  arc  set  free 
and  dissociated  ;  they  then  develop,  as  they  did  within  the  mass,  and 
soon  give  rise  to  as  many  new  colonies,  each  of  wliicli  soon  becomes 
surrounded  by  its  own  membrane,  or  constitutes  a  cell  of  the  second 
order.  Van  Tiegheni  has  denominated  this  organism  Ascohaderia 
nlviiia. 

Ascococcus  Cohn  — In   Ascococcus  Billrothii  Cohn,  as  in  the  three 


1004  RECORD    OF    CURRENT   RESEARCHES    RELATING    TO 

species  of  Punctula,  the  excessively  minute  cells  of  the  colony  are 
immobile.  They  are  so  closely  bound  together  by  a  firm  cement  as 
not  to  be  easily  separated.  This  is  not  the  case  with  another  species  of 
Ascococcus  which  the  writer  met  with  on  the  surface  of  water  contain- 
ing various  aquatic  plants,  where  Begcjiatoa  was  putrefying,  and 
which  exhaled  a  strong  odour  of  ammonia  sulphohydrate.  Here  the 
cells,  also  extremely  minute,  moved  with  a  very  rapid  oscillating  and 
whirling  motion  in  the  interior  of  the  membrane,  and  having  all  the 
appearance  of  a  Brownian  movement.  Hence  this  species  has  been 
termed  Ascococcus  vihrans. 

All  the  social  bacteria  hitherto  described  are  aerobes,  producing 
an  energetic  combustion  in  albuminoid  substances  on  the  surfaces  of 
which  they  are  formed,  and  often,  if  not  always,  disengaging  a  large 
quantity  of  ammonia,  a  phenomenon  which  Cohn  has  already  described 
in  the  case  of  Ascococcus  Billrothii. 

From  the  observations  above  described,  M.  Van  Tieghem  deduces 
a  confirmation  of  his  view  already  published  that  the  cell  cannot  in 
any  sense  be  regarded  as  an  element.  It  may,  in  fact,  be  split  up,  a 
fragment  may  be  separated  from  it,  and  this  fragment,  when  placed 
in  favourable  conditions,  will  retain  all  the  properties  of  the  entire 
cell,  and  will  be  able  to  regenerate  it.  The  plant  itself  also  carries  on 
at  every  moment  this  splitting  up  of  its  cells  into  similar  and 
complete  parts,  often  very  numerous  and  minuto.  It  is  indeed  on 
this  division  that  all  increase  and  reproduction  depend.  The  j)roto- 
plasmic  body  of  a  cell  is  then,  in  fact,  an  assemblage  of  similar  2)arts, 
each  complete  in  itself,  which  may  be  isolated  artificially,  and  which 
separate  from  one  another  naturally  by  the  processes  of  growth  and 
reproduction,  altho^^gh  these  parts  are  actually  in  continuity  with  one 
another,  and  subject  to  a  common  law  of  development.  In  a  large 
cell  there  is  a  great  number  of  these  similar  parts,  and  a  great 
number  of  fragments  can  be  cut  oft"  from  it,  equivalent  among  them- 
selves and  to  the  entire  cell.  In  a  small  cell  there  are  fewer  such 
parts.  Finally,  when  the  cell  is  reduced  below  the  size  measurable 
with  precision  by  our  existing  instruments,  the  fact  that  it  still  divides 
is  clear  evidence  that  it  can  no  longer  be  regarded  as  an  irreducible 
element.  The  analysis  of  the  cell  shows,  therefore,  that  it  is  not,  as 
has  generally  been  stated,  the  formative  morphological  element  of 
organisms. 

These  observations  on  social  bacteria  lead,  in  another  way,  by  a 
synthetic  path,  to  the  same  conclusion.  We  see,  in  fact,  in  them, 
small  cells  springing  from  a  primitive  cell,  and  grouping  themselves 
into  an  intimate  association  governed  by  a  common  law  of  growth ; 
this  association  assuming  a  definite  form  and  dividing  in  a  certain 
manner  when  it  has  attained  a  certain  size,  and  then  multiplying  and 
maintaining  each  time  its  new  parts  formed  in  a  certain  relative 
position.  In  one  word,  this  association  of  similar  cells  behaves  in  all 
respects  like  a  simple  cell ;  it  is,  in  fact,  a  compound  cell.  When 
crushed,  each  part  is  able,  like  a  simple  cell,  to  exist  independently, 
and  to  regenerate  the  entire  colony.  There  is,  however,  one 
dificrence.     This  crushing  only  eft'ects  a  separation  of  the  cells  which 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1005 

have  been  seen  to  form  themselves  and  to  become  acslomerated  in 
order  to  constitute  the  compound  cell,  while  in  a  simple  cell  the 
detached  fragments  have  no  known  origin  nor  precise  morphological 
significance. 

The  increase  of  tlie  body  of  the  compound  cell,  resulting  from  the 
repeated  and  simultaneous  bipartiticm  of  its  several  cylindrical  or 
spherical  cells,  closely  resembles  tlie  mode  of  increase  of  so  many 
constituent  parts  of  the  protoplasmic  body  of  a  simple  cell,  for 
example,  of  the  chlorophyll-grains  or  nuclei.  The  recent  researches 
of  Baranetzky  *  have  shown  that  the  nucleus  is  composed  of 
elements  bearing  the  form  of  rods,  and  that  it  increases  by  the 
elongation  and  repeated  bipartition  of  these  rods,  just  as  bacteria  do ; 
and  that  it  is  this  increase  itself  which,  not  being  able  to  pass  a  certain 
limit,  brings  about  the  division.  Between  a  nucleus  thus  constituted 
and  the  body  of  a  compound  cell  of  a  Polyhacteria  there  is  a  striking 
resemblance.  One  day  it  will  perhaps  be  demonstrated  that  this 
similarity  of  constitution  and  of  growth  extends  to  the  whole  of  the 
protoplasm  of  the  simple  cell. 

A  blow  is  thus,  in  the  opinion  of  M.  Van  Tieghem,  struck  at  the 
view  of  the  cell  as  an  element,  whether  morphological  or  physiological, 
and  at  the  foundation  of  the  cell-theory. 

Development  and  Fermenting  Power  of  Bacteria.f — Prazmowski 
has  specially  studied  the  development  and  properties  of  the  genera 
Bacillus  Colin,  Clostridium  Prz.  n.  gen.,  and  Vibrio  Cohn.  Oi  Bacillus 
suhtilis  Cohn,  he  has  closely  followed  both  the  germination  and 
the  formation  of  the  spores.  He  believes  it  to  have  no  fermenting 
power,  since  it  dies  the  moment  it  is  deprived  of  oxygen.  B.  Ulna 
was  found  by  him  in  rotten  eggs,  and  in  the  spore-producing  state, 
but  he  was  not  able  to  connect  it  with  the  process  of  decay. 

The  butyric  ferment,  or  "  vibrion  butyrique  "  of  Pasteur,  is  known 
under  the  various  names  of  Amylobacter  Clostridium,  Urocejjhalum 
Trecul,  Bacillus  Amylohacter  v.  Tiegh.,  and  Bacterium  Navicula  Reink. 
et  Berth.  Tlie  author  establishes  from  it  a  new  genus  Clostridium, 
of  which  two  species  arc  described.  The  first,  C.  butyricnm  (Bacillus 
Amylobacter  v.  Tiegh.)  is  completely  anaerobic,  the  spores  germinating 
at  one  end,  instead  of,  as  in  Bacillus  subtilis,  in  the  middle.  The 
second  species,  C.  Polymyxa  Prz.,  is  new,  though  closely  resembling 
G.  butyricum,  is  almost  entirely  aerobian,  and  can  only  produce  its 
spores  under  access  of  oxygen  ;  when  air  is  excluded,  it  incites 
fermentation,  but  soon  dies. 

Vibrio  Rur/uln  Miiller  has  only  been  found  by  the  author  along 
with  other  bacteria  ;  the  formation  of  spores  was  observed,  but  not 
germination.     It  decomposes  cellulose. 

The  formation  of  jelly  or  zooghea-condition  of  bacteria  is  believed 
by  Prazmowski  to  indicate  an  affinity  with  the  lower  Ab'tc. 

Witli  regard  to  the  anatomy  of  the  spores,  he  states  that  they  are 
*  Sfd  this  Journal,  rin/r,  p.  !>7fl. 

t  I'ruziiKiw.ski,  A.,  '  lliitcr.-<iicli.  iibor  dio  EntwickolungspoRoliiolito  u.  Fer- 
nifntwiikiiii",'  ciniRor  Hac-tfiU'ii-Artcn.'  Leipzig,  18h0.  fcleo  '  Hot  Zeit  ' 
xxxviii.  (KSHO)  p.  .V2H. 

VOL.  in.  3  X 


1006  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

certainly  surrounded  by  a  cell-wall,  but  disputes  tbe  statement  of 
Brefeld  that  they  possess  an  epispore  and  a  clear  intermediate  space. 

Effect  of  Putrefactive  Changes  on  Bacteria.* — In  all  solutions 
containing  Bacteria  a  time  arrives  when  they  cease  to  propagate,  and 
after  a  longer  time  they  lose  their  power  to  induce  further  life  in 
fresh  nutrient  solutions.  The  admitted  fact  leads  to  the  belief  that 
the  putrefaction  induced  by  Bacteria  produces  substances  which  are 
poisons  to  these  organisms. 

Experiments  have  been  made  by  Dr.  Wernich  on  meat  extracts  of 
various  ages  with  phenol,  skatole,  indole,  and  other  putrefaction- 
products,  all  of  which  were  found  to  exercise  an  injurious  effect  on 
Bacteria  ;  moreover,  substances  most  disposed  to  putrefaction  were 
easily  preserved  from  it  by  means  of  any  of  them  in  fresh  solutions 
which  were  purposely  impregnated.  The  addition  of  trifling  quan- 
tities of  these  matters  promptly  caused  inactivity  of  the  Bacteria,  and 
the  author  considers  he  has  fully  proved  the  truth  of  Baumann  and 
Nencki's  propositions  on  the  subject. 

The  experiments  in  question  lead  to  the  solution  of  a  highly 
interesting  problem  in  pathology.  The  author  says  that  the  same 
or  similar  operations  are  carried  out  in  the  progress  of  septic 
diseases  ;  the  supposition  that  the  organisms  which  are  the  cause  of 
infectious  diseases  give  rise  to  products  which  eventually  cause  their 
own  destruction,  is  the  only  way  in  which  the  progress  of  these 
diseases  can  be  properly  comprehended.  Many  diseases,  such  as 
small-pox,  measles,  scarlet  and  relapsing  fever,  which  are  now 
generally  ascribed  to  the  presence  of  Bacteria,  progress  so  peculiarly 
and  take  such  a  regular  course  that  one  is  forced  to  believe  that,  with 
the  cause  of  the  malady,  its  own  distinctive  poison  is  produced  in  the 
same  manner  as  in  the  experiments  here  noted. 

Theory  of  Virulent  Diseases  and  the  "Fowl-Cholera.''t — The 
view  that  the  infectious  diseases,  such  as  measles,  scarlet  fever,  small- 
pox, syphilis,  splenic  fever,  yellow  fever,  typhus,  and  others,  are  con- 
nected with  the  presence  and  operation  of  organized  ferments,  the 
communication  of  which  from  one  individual  to  another  constitutes 
the  infection,  has  lately  met  with  increasing  support.  Hitherto, 
however,  except  in  the  case  of  splenic  fever,  direct  and  conclusive 
proofs  of  this  hypothesis  have  not  been  forthcoming;  but  in  the 
instance  named  the  bacteria  which  cause  it  have  been  discovered,  and 
their  mode  of  action  so  far  determined  that  it  is  possible  by  their 
means  to  produce  the  disease  whenever  desired.  Very  recently 
M.  Pasteur  has  been  able  to  rear  the  organism  which  is  the  cause  of 
another  disease,  and  to  study  its  biological  peculiarities.  As  the 
investigation  throws  light  on  the  mysterious  question  of  the  immunity 
of  individuals  from  a  given  contagious  disease  from  which  they  have 
recovered,  the  facts  elicited  may  be  given  more  at  length. 

*  'Bied.  Centr.,'  1880,  pp.  224-6.  See  '  Journ.  Chem.  Soc.,'  Abstr.  xxxviii. 
(1880)  pp.  726-7.     See  also  this  Journal,  ajite,  p.  314. 

t  '  Comptes  Reudus,'  xc.  (1880)  pp.  239-48.  Cf.  '  Naturforscher,'  xiii.  (1880) 
pp.  117-18;  also  Prof.  J.  Lister's  address  to  Annual  Meeting  of  British  Medical 
"    Association  at  Cambridge,  'Brit.  Med.  Journ.,'  1880,  pp.  363-5. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1007 

A  disease,  usually  known  as  hen-cholera,  sometimes  appears  with 
very  disastrous  effects  among  fowls.  The  animal  attacked  by  it  is 
extremely  prostrated,  the  gait  is  irregular,  the  feathers  become  erect, 
the  wings  droop,  a  heavy  somnolence  comes  over  it,  ending  in  a  quiet 
death  :  perceptible  alterations  are  also  caused  in  the  internal  organs. 
The  observations  of  Messrs.  Moritz,  Peroncito,  and  Toussaint  have 
shown  it  to  be  caused  by  a  microscoj^ic  form  of  life,  the  last-named 
observer  having  proved  by  direct  cultivation  of  it  in  neutral  urine 
that  it  is  the  origin  of  the  poisoning  of  the  blood. 

M.  Pasteur  had  not  the  same  success  in  his  attempts  at  rearing  it 
pure  in  neutral  urine,  but  found  a  very  favourable  medium  for  the 
purpose  in  a  broth  made  from  fowls'  muscle,  neutralized  by  potash  and 
heated  to  from  110^  to  115°  C.  so  as  to  sterilize  it.  The  organism 
multijilies  in  this  liquid  with  such  rapidity  that  in  a  few  hours  the 
most  transparent  solution  commences  to  be  clouded,  and  is  filled 
with  immense  numbers  of  minute  and  extremely  delicate  oval-shaped 
structures  slightly  constricted  in  the  middle,  and  appearing  at  first 
sight  like  isolated  points.  Their  transverse  diameter  is  from  t^^^j^ 
to  ^5 Joij-  inch.  They  have  no  independent  movements,  and  it  is 
certain  that  they  belong  to  a  group  quite  distinct  from  the  Vibriones. 
These  microbia  of  the  fowl-cholera  present  the  striking  peculiarity  of 
rapidly  perishing  in  yeast-liquid  (although  the  Bacteria  of  splenic 
fever  flourish  admirabl}'^  and  reproduce  in  this  fluid) ;  for  in  less  than 
twenty-four  hours  they  have  all  died,  while  any  foreign  bodies  accom- 
panying them  continue  their  own  growth ;  this  liquid  therefore 
furnishes  a  valuable  reagent  by  which  to  ensure  the  purity  of  growths 
which  may  be  introduced  into  the  solution  of  fowls'  muscle. 

If  guinea-pigs  are  inoculated  with  this  organism,  an  exclusively 
local  injury  is  caused,  especially  at  a  certain  age  ;  this  ends  in  an  abscess 
of  greater  or  less  size.  If  the  abscess  opens  of  itself,  it  heals  up 
without  having  caused  the  animal  the  least  harm  ;  it  may  persist  for 
several  weeks,  and  in  this  case  is  found  full  of  a  cheesy  j)us  contain- 
ing quantities  of  the  raicrobion  among  the  pus-cells.  Here  it  lives  as 
in  a  closed  vessel,  witliout  injuring  the  animal;  it  remains  very  pure, 
and  does  not  lose  its  vital  powers.  On  inoculating  fowls  with  the 
contents  of  the  boils,  they  are  found  to  die  very  (juickly ;  the  guinea- 
pig  may  also  die  from  its  effects,  but  only  when  under  special 
circumstances  tlio  matter  passes  into  the  blood  or  the  intestines.  It 
sometimes  hap)»en8  that  fowls  or  rabbits  living  with  the  infected 
guinea-pigs  suddenly  become  ill  and  die  without  the  health  of  the 
latter  suffering  in  the  least ;  it  is  only  necessary  for  some  of  the 
abscesses  to  open  si)oiitaneonsly  and  a  portion  of  their  contents  to 
reach  the  food  of  the  raJjbits  or  fowls.  Witliout  a  knowledge  of  the 
relations  thus  made  known,  one  wouM  scarcely  su])poso  the  healtliy 
guinca-{)igs  to  be  the  cause  of  the  decimation  of  their  neighbours,  but 
would  ratlier  believe  a  spontaneous  disease  to  be  its  origin. 

In  order  to  cause  infection,  it  is  only  necessary  to  place  a  few 
drops  of  a  crop  of  the  organism  on  the  bread  or  meat  given  as  food  to 
the  fowls ;  it  undergoes  so  rapid  a  development  in  their  alimentjiry 
canal  that  their  very  excrement  when  used   to  inoculate  other  imli- 

3x2 


1008  RECORD    OF    CURRENT   RESEARCHES   RELATING   TO 

viduals,  is  sufficient  to  cause  tlieir  death ;  and  tliis  is  doubtless  the 
manner  in  which  this  disease  is  spread  through  the  fowls  inhabiting 
any  one  yard.  The  isolation  of  the  sick  from  the  sound  birds, 
together  with  the  most  careful  cleansing  of  the  yard  and  the  mainte- 
nance of  it  in  a  clean  state,  will  certainly  suffice  to  put  a  stop  to  the 
spread  of  the  malady. 

The  repeated  cultivation  of  the  microbion  in  fowls'-broth  by  im- 
pregnating each  successive  liquid  with  an  infinitely  small  quantity  of 
the  preceding  liquid,  weakens  in  no  degree  the  poisonous  properties  of 
the  agent.  Its  virulence  is  so  great  that  inoculation  by  a  very  small 
portion  of  a  drop  of  one  of  the  growths  thus  reared  causes  death  in 
every  instance  within  two  to  three  days,  and  very  often  within  twenty- 
four  hours.  It  is  possible  by  certain  modifications  of  the  method  of 
cultivation  to  bring  about  a  mitigation  of  this  virulence.  The  occur- 
rence of  this  mitigation  is  marked  by  a  slight  retardation  of  the 
development  of  the  microbion,  "  but  in  reality  the  two  kinds  of 
poison  are  identical.  In  the  first,  the  most  deadly  condition,  the 
microbion  may  cause  death  twenty  times  in  twenty  cases  of  inocula- 
tion ;  in  the  second,  out  of  twenty  cases  of  inoculation  it  causes 
twenty  cases  of  disease,  but  never  death.  These  facts  have  an 
importance  which  is  readily  apjireciable ;  they  allow  us,  in  fact, 
to  decide  the  problem  of  the  recurrence  or  non-recurrence  of  the 
disease  now  in  question.  If  we  take  forty  fowls  and  inoculate 
twenty  of  them  with  a  very  poisonous  specimen  of  infecting  material, 
the  twenty  fowls  die ;  if  we  inoculate  the  remaining  twenty  with 
weakened  poison,  they  become  one  and  all  ill,  but  will  not  die.  If 
we  now  let  them  become  well  again,  and  inoculate  these  twenty  fowls 
with  the  most  poisonous  substance,  it  will  now  no  longer  kill  them. 
The  conclusion  to  be  drawn  from  this  is  clear ;  the  malady  is  a  safe- 
guard against  itself.  It  has  the  characters  of  the  infectious  diseases, 
which  do  not  recur." 

At  this  point  M.  Pasteur  reminds  us  that,  of  course,  this  fact  is  of 
itself  nothing  new,  for  man  has  long  been  successfully  protected  against 
small-pox  by  inoculation  with  cow-pox,  the  sheep  in  some  places 
against  hoof-disease,  the  cattle  against  the  rinderpest,  and  it  is  also 
well  known  that  people  who  have  passed  through  measles,  scarlet 
fever,  syphilis,  &c.,  are  not  again  attacked  by  these  diseases.  The 
new  and  important  point  about  the  cholera  of  fowls  is  this,  that  we 
have  found  the  infecting  agent  in  this  disease  to  consist  of  a  micro- 
scopic parasite,  which  may  be  cultivated  outside  the  body,  and  which 
not  only  evokes  the  disease,  but  also  affi^rds  immimity  against  the 
effects  of  a  repeated  inoculation  as  distinctly  as  the  contagious 
diseases. 

The  following  passage  of  M.  Pasteur's  memoir  qualifies  slightly  the 
conclusion  arrived  at  above  : — 

"  I  do  not  wish  to  have  it  believed  that  the  facts  present  the  mathe- 
matical exactness  and  regularity  which  I  have  described.  That  is,  my 
statements  do  not  take  account  of  the  great  variability  which  is  acci- 
dentally presented  by  the  constitutions  and  general  vital  powers  of 
individuals  taken  from  a  collection  of  domestic  animals.    No,  the  most 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1009 

active  poison  of  the  fowl-cholera  does  not  always  kill  twenty  times  in 
twenty  cases,  but  in  the  observed  cases  which  I  have  seen  with  my 
own  eyes,  it  has  killed  at  least  eighteen  times  out  of  twenty  in  those 
instances  where  it  has  not  killed  twenty  times.  Similarly  the  poison 
which  has  had  its  violence  diminished  has  not  always  preserved  life 
twenty  times  out  of  twenty  cases ;  in  the  cases  of  inferior  protection 
this  occurred  sixteen  or  eighteen  times  out  of  the  twenty.  Further, 
it  does  not  absolutely  and  by  a  single  inoculation  prevent  a  recurrence 
of  the  disease ;  this  non-recurrence  is  attained  much  more  surely  by 
two  inoculations  than  by  one." 

Since  M.  Pasteur's  first  experiments,  he  has  investigated  the 
conditions  of  immunity  more  fully,  and  has  arrived  at  the  following 
hypothesis  of  the  real  natui'c  of  the  protective  operation  and  the 
reasons  for  the  immunity.* 

Numerous  experiments  had  shown  that  the  inoculation  with  the 
weaker  poison  (which  on  the  grounds  of  analogy  and  simplicity  is 
named  vaccination)  gives  such  diiferent  results  with  different  fowls, 
that  in  one  case  one  vaccination  is  sufficient  to  cause  entire  immunity 
against  the  deadlier  poison,  while  in  others  a  once-  and  even  twice- 
repeated  vaccination  is  necessary.  To  illustrate  this,  let  eighty  fowls 
be  taken,  and  twenty  of  them  be  inoculated  with  the  violent  poison, 
these  twenty  will  die ;  inoculate  the  next  twenty  with  the  mitigated 
poison  and  none  of  them  will  die ;  if  these  twenty  fowls  which  have 
once  undergone  vaccination  be  inoculated  with  the  stronger  poison, 
about  six  or  eight  will  remain  alive.  A  fresh  series  of  twenty  fowls 
may  be  vaccinated  on  two  occasions,  one  operation  to  follow  the  other 
after  an  interval  of  seven  to  eight  days,  and  inoculation  with  the  deadly 
poison  is  now  without  danger  to  from  twelve  to  fifteen  of  the  number. 
If  a  batch  of  twenty  new  fowls  is  now  vaccinated  three  or  four  times  in 
succession,  the  inoculation  with  the  powerful  poison  will  cause  neither 
the  death  or  even  the  sickness  of  any  more.  In  this  last  case  the  fowls 
can  never  again  take  the  disease. 

With  regard  to  the  reason  of  the  immunity,  we  cannot  avoid  the 
idea  that  tlio  microscopic  organism  which  causes  the  disease,  finds  in 
the  body  of  the  animal  a  medium  in  which  to  grow,  and  tliat  it  alters 
or  destroys  certain  substances  while  carrying  out  the  activities  of 
its  own  life.  But  wlion  the  perfect  immunity  is  attained,  one  may 
inoculate  any  muscle  one  pleases  with  the  more  deadly  organism 
without  obtaining  the  slightest  effect,  that  is,  all  cultivation  in  these 
muscles  is  now  impossible  ;  tliey  no  longer  contain  materials  to  nourish 
the  microbiou. 

The  question  now  is,  whether  this  suppression  of  the  j)ossibility  of 
any  cultivation  of  the  parasite  in  the  muscles  is  limited  to  these  j)art8 
which  have  undergone  the  protective  inoculation.  To  decide  tliis,  a 
new  series  of  strongly  vacciiuited  fowls  was  once  inoculated  by  intro- 
duction of  tlie  poison  into  tlic  jugular  vein,  and  in  a  second  series  of 
experiments  by  feeding  witli  tlie  infectod  muscles  of  a  fowl  wliieh  had 
died  of  tho  parasite.     The  result  was  that  in   both   cases  tlic  fully 

•  'Coniptcs  Uciulus,'  xc.  (ISSit)  pp.  '.>;V2-8.  Cf.  '  NiiturroMolicr,'  xiii  (1880) 
pp.  -247-8. 


1010  RECORD    OF    CURRENT   RESEARCHES   RELATING   TO 

vaccinated  individuals  were  uninjured,  none  of  them  dying;  while 
those  not  vaccinated  succumbed  to  the  poison,  both  when  this  was 
directly  introduced  into  the  blood  and  when  it  was  introduced  by  the 
alimentary  canal. 

Experience  shows  that  there  are  individual  fowls  which  are 
proof  from  their  birth  against  the  poison,  being  protected  by  their  con- 
stitution against  taking  the  disease.  Therefore  it  must  be  assumed 
in  their  case  that  they  are  devoid  of  the  substance  which  forms  the 
nutriment  of  the  microbion,just  in  the  same  way  as  the  liquor  of  beer- 
yeast  is  absolutely  unfitted  to  nourish  the  same  parasite,  while  other 
microscopic  organisms  thrive  very  well  in  this  liquid. 

"  The  explanation  to  which  the  facts  lead  us,"  says  M.  Pasteur, 
"  both  with  regard  to  the  innate  resistance  which  certain  individuals 
manifest,  and  to  the  immunity  which  is  induced  by  repeated  vaccina- 
tions, appears  very  natural  when  one  remembers  that  in  general  every 
process  of  cultivation  alters  the  medium  in  which  it  takes  place  :  the 
soil  is  altered  when  it  comes  in  contact  with  ordinary  plants  ;  plants  and 
animals  are  altered  when  they  meet  with  their  parasites,  and  our  culti- 
vating liquids  are  altered  when  they  meet  with  Mucedinefe,  Vibriones, 
or  ferments.  These  modifications  are  both  betrayed  and  characterized 
by  the  circumstance  that  fresh  growth  of  the  same  species  in  these  media 
is  impossible  or  very  difiicult.  If  we  sow  fowls'  broth  with  the  cholera 
microbion  and  filter  the  liquid  after  three  or  four  days  to  remove  every 
trace  of  it,  and  sow  the  filtered  liquid  afresh  with  the  parasite,  this 
shows  itself  entirely  incapable  of  undergoing  the  slightest  development. 
If  the  liquid  is  entirely  clear  after  the  filtering,  it  preserves  this  clear- 
ness intact. 

Must  not  the  thought  occur  to  us,  that  by  the  cultivation  of  the 
weakened  poison  in  the  fowl,  its  body  is  put  into  the  position  of  the 
filtered  liquid,  which  cannot  support  the  microbion.  The  comparison 
may  be  followed  out  further,  for  if  the  solution  is  filtered  while  the 
cultivation  of  the  microbion  is  in  full  activity — not  on  the  fourth,  but 
on  the  second  day  of  growth — then  the  filtered  liquid  will  still  be  in 
a  condition  to  grow  the  microbion  afresh,  though  less  energetically 
than  at  first.  We  see  therefore  that  after  cultivation  of  the  weakened 
microbion  in  the  fowl's  body  we  have  not  been  able  to  exhaust  its 
nutriment  in  all  parts  of  the  body.  Thus  that  which  is  left  behind 
will  allow  of  a  fresh  growth,  but  again  to  a  more  limited  extent.  This 
is  the  action  of  the  first  vaccination.  Subsequent  inoculations  will 
gradually  remove  all  the  material  for  the  cultivation  of  the  parasite. 
Through  the  action  of  the  circulation  a  moment  must  come,  at  which 
any  fresh  growth  in  the  fowl  remains  unfruitful.  Then  the  disease 
can  no  longer  recur,  and  the  individual  is  fully  vaccinated.  It  may 
be  wondered  that  a  first  growth  of  the  mitigated  poison  should  remain 
inactive,  before  the  materials  for  nourishing  the  microbion  are 
exhausted.  But  we  should  not  forget  that  as  the  microbion  is  a  gas- 
needing  being,  it  exists  by  no  means  under  the  same  conditions  in  the 
body  of  the  animal  as  in  an  artificial  medium  for  growth.  Here  there 
is  no  obstacle  to  its  increase.  In  the  body,  on  the  contrary,  it  is 
incessantly  in  conflict  with  the  cells  of  the  organs,  which  are  in  like 


INVEETEBBATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1011 

manner  beings  which  need  gas,  and  are  always  ready  to  seize  upon 
the  oxygen. 

But  is  this  the  only  possible  explanation  of  the  phenomena  ?  Not 
strictly  speaking.  We  can  account  for  the  facts  of  non-recurrence  if 
we  assume  that  instead  of  removing  and  destroying  certain  substances 
in  the  body  of  the  animals,  the  life  of  the  microbion  introduces  certain 
others  which  are  a  hindrance  to  tho  further  development  of  this 
microbion.  The  life-history  of  the  lower  organisms,  and  in  general 
of  all  organisms,  justifies  such  an  assumption.  The  excreta  produced 
by  the  vital  processes  may  oppose  a  vital  function  of  the  same  species. 
In  certain  fermentations  antiseptic  products  are  seen  to  arise,  during 
and  as  the  result  of  the  fermentation,  which  put  an  end  to  the  active 
life  of  the  ferments  and  to  the  fermentation  long  even  before  this. 
A  formation  might  take  place  during  the  cultivation  of  our  microbion 
of  products  whose  presence  would  strictly  explain  the  immunity  and 
the  vaccination. 

But  our  artificial  cultivation  of  the  parasite  allows  us  to  control 
this  hypothesis  as  well.  Let  us  prepare  an  artificial  growth  of  the 
microbion,  and  after  evaporating  it  under  the  influence  of  cold  and  in 
a  vacuum,  restore  it  to  its  original  volume  by  a  cultivating  solution. 
If  the  extract  contains  what  is  a  poison  to  the  life  of  the  micro- 
bion, and  if  this  is  a  reason  for  cultivation  being  impossible  in  the 
filtered  liquid,  then  the  sowing  in  the  fresh  medium  should  prove 
unfruitful ;  but  it  is  not  so.  Thus  it  is  impossible  to  believe  that 
substances  appear  during  the  life  of  the  parasite  which  are  able  to 
oppose  its  further  development.  This  observation  confirms,  on  the 
contrary,  the  former  theory,  given  above,  with  regard  to  the  causes  of 
the  non-recurrence  of  certain  infectious  diseases." 

A  further  fact  in  support  of  his  views  of  the  nature  of  tho 
immunity  and  the  vaccination  was  communicated  by  M.  Pasteur  to  the 
Academy :  *  In  well-vaccinated  and  healthy  fowls  sometimes  appear, 
in  one  part  or  other  of  the  body,  boils,  full  of  pus,  which  have  caused 
no  injury  to  tho  health  of  the  bird.  It  was  remarkable  that  these 
boils  originated  from  the  cholera  microbion  which  was  preserved  in 
them  as  in  a  closed  vessel,  and  doubtless  was  only  imablc  to  rejiroduce 
itself  because  the  fowl  was  vaccinated.  The  pus  could  be  taken  from 
the  boils  and  cultivated,  or  fresh  fowls  could  be  inoculated  with  it, 
in  which  it  developed  largely  and  killed  them  in  tho  ordinary 
way.  These  facts  remind  us  of  the  observations  which  M.  Pasteur 
described  in  his  first  memoir  on  the  bcliaviour  of  tho  guinea-pig  with 
regard  to  inoculation  with  tho  poison  of  fuwl-cholera. 

]\r.  Pasteur  lias  followed  up  f  his  experiments  in  fowl-cholera  by  in- 
vestigating with  regard  to  the  germ-theory  the  case  of  a  patient  aftlicted 
with  an  intermittent  eruption  of  boils.  He  found  the  matter  formed 
in  the  cones  of  the  boils  to  produce,  when  added  to  a  proper  culti- 
vating liquid,  numerous  microscopic  spherical  bodies  united  together, 
generally  in  pairs.  The  same  occurred  with  matter  taken  from  a  loss 
advanced  boil.     Diflfercntial  experiments  showed  tho  production  of 

•  'Comptca  Kcndus,'  xc.  (18S0)  pp.  1030-3.  Cf.  '  Nuturforschcr,'  xiii.  (1880) 
p.  218.  t  Il>id-,  PP-  1033-44. 


1012  RECORD    OF    CURRENT   RESEARCHES   RELATING   TO 

the  bodies  by  this  matter,  and  not  by  blood  or  lymph  taken  from 
other  parts  of  the  same  subject,  even  when  from  the  very  edge  of  the 
boil.  Three  separate  subjects  were  experimented  on,  and  from  each  the 
same  microscopic  organism  was  obtained. 

By  injecting  the  cultivated  growths  of  the  organism  under  the  skin 
of  rabbits,  &c.,  small  and  readily  healed  abscesses  were  produced  in 
which  the  organism  was  found  in  a  state  of  development.  Injected 
into  the  jugular  vein  of  guinea-pigs,  the  growths  produced  no  result, 
a  circumstance  which  is  important  as  confirming  other  experiments 
which  show  the  difficulty — due  probably  to  its  healthy  activity  and  the 
absorption  of  oxygen  by  the  blood-corj)uscles — of  propagating  such 
organisms  in  blood.  The  disease  osteomyelitis  is  also  accompanied  by 
the  same  growth,  in  the  form  of  minute  grains  aggregated  by  twos 
and  larger  numbers. 

In  an  ultimately  fatal  case  of  puerperal  fever,  the  lochia  were  found 
to  contain  the  same  organism.  Two  days  later,  the  blood  itself  was 
found  to  contain  a  growth  of  long  chains  of  cells.  After  death,  pus 
from  the  peritoneum,  the  blood  of  the  basilic  and  femoral  veins,  and 
pus  from  the  surface  of  the  uterus  and  Fallopian  tubes  was  found  on 
cultivation  to  contain  the  germs  of  the  long  chains  of  cells.  In  the 
peritoneal  matter  occurred  a  vibrio,  already  described  as  "  organism  of 
the  pus."  In  another  instance,  in  which  the  mother  and  child  both 
died,  the  boil-organism  and  the  pus-vibrio  were  found  in  the  lochia 
and  in  the  milk,  and  the  inoculation  of  a  rabbit  with  the  matter  caused 
the  development  in  it  of  large  abscesses.  In  another  case  the  blood 
and  the  synovial  membrane  of  the  knee  were  ultimately  affected  by 
the  chain-like  microphyte.  In  the  blood  of  an  infant  which  died  soon 
after  birth,  was  found  the  pyogenic  vibrio.  The  only  indications  of 
disease  found  in  the  mother  were  a  number  of  abscesses  in  the  liver 
and  ulcerations  on  the  hepatic  vein.  The  lymphatics  of  the  uterus 
appear  in  some  cases  to  distribute  the  disease-germs  to  the  rest  of  the 
body. 

Professor  Lister,  in  his  address  to  the  Cambridge  Meeting  of  the 
British  Medical  Association,*  says :  "  I  need  hardly  remark  on  the 
surpassing  importance  of  researches  such  as  these.  No  one  can  say 
but  that,  if  the  Association  should  meet  at  Cambridge  again  ten  years 
hence,  some  one  may  be  able  to  record  the  discovery  of  the  appro- 
priate vaccine  for  measles,  scarlet  fever,  and  other  acute  specific 
diseases  in  the  human  subject.  But  oven  should  nothing  more  be 
effected  than  what  seems  to  be  already  on  the  point  of  attainment — 
the  means  of  securing  poultry  from  death  by  fowl-cholera,  and  cattle 
from  the  terribly  destructive  splenic  fever,  it  must  be  admitted  that 
we  have  an  instance  of  a  most  valuable  result  from  the  much-reviled 
vivisection." 

Fowl-Cholera  and  "Sleep  Disease."  t — M.  Talmy  has  been  struck 
by  the  resemblance  of  the  fowl-cholera  to  the  "  sleep  disease "  or 
"  nelavan,"  which  attacks  the  natives  of  the  west  coast  of  Africa. 
In  this  disease,  whose  symptoms  may  be  compared  with  those  given 

*  Loc.  cit.  t  'Comptes  Rendus,'  xc.  (1880)  pp.  1014-17. 


INVERTEBRATA,    CRYPTOQAMIA,    MICROSCOPY,    ETC.  1013 

above  for  tlie  fowl-cholera,  the  eyelids  are  half  closed.  At  certain 
times  an  urgent  want  of  sleep  is  felt ;  later,  sleep  becomes  continuous  ; 
the  sick  person  has  to  be  awakened  for  his  meals.  Sleep  now  takes 
place  in  the  most  various  and  uncomfortable  attitudes,  but  in  such  as 
need  no  muscular  effort;  the  body  gradually  becomes  stretched  out  until 
death  ensues  quietly  and  without  pain.  The  patients  are  sometimes 
affected  at  the  same  time  with  swellings  on  the  neck,  and  these  have 
been  excised  with  the  effect  of  curing  the  disease.  The  disease  appears 
to  differ  from  that  affecting  fowls,  in  its  long  duration — lasting  a 
year  or  two  in  some  cases — and  in  inevitably  proving  fatal.  It 
is  said  to  attack  individuals  who  have  eaten  large-necked  fowls  or 
fish  with  swollen  gills ;  hence  these  animals  should  be  carefully 
studied  in  order  to  trace  the  connection  between  their  condition  and 
the  disease  which  attacks  human  beings. 

With  reference  to  this  subject,  M.  Declat  quotes  *  the  cure  of  two 
cases  of  the  disease  by  means  of  phenic  acid,  which  is  used  so  success- 
fully in  the  case  of  other  diseases  due  undoubtedly  to  septic  organisms. 
This  seems  to  confirm  the  belief  in  a  similar  origin.  The  phenic 
acid  solution  is  injected,  100  drops  at  a  time,  and  these  injections 
are  often  repented.  A  gradual  recovery  followed  the  operation  in  the 
two  cases  quoted. 

Fowl-Cholera  and  Anthrax.t  —  lu  a  letter  to  M.  Dumas, 
M.  Pasteur  alludes  to  his  experiments  J  on  the  cultivation  of  the 
fowl-cholera  bacterium  in  fowls'  broth  (which  appear  to  show  that 
in  the  process  certain  principles  necessary  to  the  life  of  the  bacterium 
are  removed  from  the  liquid),  and  to  his  subsequent  ojiiniou  that 
probably  fowls  vaccinated  for  the  "  cholera "  would  not  be  proof 
against  antlirax.  Numerous  exjieriments  have,  however,  since  shown 
him  that  the  effects  of  anthrax  on  a  medium  inoculated  against  fowl- 
cholera  are  slow,  small  in  amount,  and  difficult  to  ])r(jduce.  Some  of 
his  experiments  tend  to  prove  that  this  result  is  shown  in  fowls 
similarly  treat(;d,  wdiich,  if  confirmed,  shows  that  an  immunity  from 
anthrax  can  be  created  by  means  of  a  parasitic  malady  of  quite 
a  diti'orent  nature. 

Etiology  of  Anthrax.§ — The  origin  and  mode  of  propagation  of 
this  disastrous  disease  are  considered  by  M.  Pasteur  worthy  of 
investigation  for  the  ])urpose  of  discovering  proj)er  means  for  its 
prevention.  Tlic  works  of  Davaine  and  Delafoud  in  France,  and 
Pollender  and  Brauel  in  Germany,  have  shown  tliat  the  blood  of 
animals  which  have  died  of  the  disease  contains  a  microscoj)ic 
parasite,  while  Koch  of  Brcslau,  in  187G,  showed  that  the  vibrionic 
form  of  the  organism  is  cupablu  of  resolution  into  spores.  Witli  the 
support  of  the  MiiiistcT  of  Agriculture,  and  the  dei)artmental  Presi- 
dent of  the  General  Council  of  Eure-et-Loire,  M.  Pasteur,  in  1878, 
instituted  experiments  on  a  small  flock  of  sheep  near  Chartres  in  the 
open  air. 

Certain  sheep  were  fed  on  lucerne,  wliich  had  been  sprinkled  with 

•  '  Coinptcs  RondiiH,'  xc.  (1880)  pp.  10S8-00.        +  Ihi.l  .  xci.  (1880)  p.  315. 
X  See  aiih;  p.  1010.  §  '  Omptes  Rendus,'  x.-i.  (1880)  p.  86. 


1014  RECORD    OP    CURRENT    RESEARCHES   RELATING   TO 

artificial  growths  of  tlie  anthrax-bacterium,  full  of  bacteria  and  germs. 
A  small  number  of  the  sheep  thus  treated  died,  after  a  period  of 
incubation  of  the  disease  of  from  eight  to  ten  days,  with  all  the  symp- 
toms of  anthrax ;  many  sheep  escaped  with  no  other  hurt  than 
becoming  decidedly  unwell.  The  mortality  increased  when  to  the  food 
treated  as  above  were  added  rough  objects,  such  as  points  of  dried 
thistle-leaves,  and  especially  the  spines  of  barley-ears  cut  into  minute 
fragments.  The  appearances  found  in  animals  which  die  under  these 
conditions  are  exactly  those  of  such  as  have  died  spontaneously  of  the 
disease,  and  show  that  its  effects  commence  in  the  mouth  or  the 
pharynx.  From  these  experiments  it  seems  that  the  anthrax- 
poisoned  animals  of  the  Eure-et-Loire  district  die  under  the  effects 
of  spores  taken  in  with  their  food. 

In  spite  of  the  opinion  of  M.  Davaine,  that  an  animal  which  has 
died  of  anthrax  cannot  communicate  the  disease  after  putrefaction, 
and  that  of  M.  Colin,  that  earth  and  water  containing  anthrax- 
infected  matters  do  not  transmit  the  infection,  it  may  be  shown  that 
though  during  putrefaction  the  bacterium  dies,  its  spores  survive  to 
propagate  infection.  The  difficulty  of  proving  this  fact  is  great,  for 
the  relative  amoimt  of  the  organism  dispersed  among  the  particles  of 
soil  is  almost  infinitesimal,  and,  when  it  has  reached  the  soil,  it  there 
meets  with  so  many  antagonistic  agencies,  in  the  form  of  other  germs 
which  compete  with  it  for  existence,  that  it  requires  very  careful 
handling  (e.  g.  cultivation  in  air  or  vacuum  or  with  other  changes  of 
medium  and  temperature)  to  bring  the  particular  species  to  maturity 
from  the  soil  examined,  even  though  it  is  there  already. 

It  is  stated  by  the  slaughterers  that  there  is  no  danger  in  handling 
the  bodies  of  the  diseased  animals  when  putrefaction  has  begun,  and 
that  there  is  no  cause  for  apprehension  when  so  doing  after  the 
animal  has  become  cold  ;  and  MM.  Pasteur  and  Joubert  have  shown 
that  when  placed  in  a  vacuum  or  in  an  atmosphere  of  carbonic  acid, 
the  bacterium  dies  and  breaks  up  into  granules,  while  its  spores  live. 
Now  it  appears  probable  that  the  bacteria  of  a  diseased  animal  which 
has  been  buried  escape  in  abundance  into  the  surrounding  earth  in 
the  blood  which  usually  issues  at  death  by  the  nostrils  and  the  mouth, 
and  in  the  urine,  and  at  a  later  stage  in  the  liquids  expelled  by  gaseous 
inflation  of  the  body ;  probably  not  even  in  the  latter  case  has  decom- 
position set  in  and  destroyed  the  parasite.  A  proof  of  this  view 
is  found  in  the  fact  that  infected  blood  added  to  earth  sprinkled  with 
yeast  liquid  or  urine,  and  kept  at  the  temperature  which  probably 
exists  around  a  decomposing  animal,  shows  that  a  multiplication  of  its 
bacteria  and  their  resolution  into  germs  takes  place.  A  still  more 
practical  proof  is  furnished  by  the  case  of  a  diseased  sheep  which 
was  buried  as  an  experiment ;  ten  months  afterwards  the  earth  of  the 
grave  furnished  germs  of  the  bacterium  capable  of  causing  the  death 
of  fowls  inoculated  with  them,  and  did  the  same  four  months  later. 
The  graves  of  some  diseased  cows  furnished  anthrax-material  during 
and  after  an  interval  of  two  years  since  burial.  Lastly,  the  bac- 
teria have  been  detected  in  the  earth  above  graves  over  which  cul- 
tivation has  been  carried  on,  and  at  those  points  of  the  field  alone. 


INVEETEBKATA,    CRYPTOGAMIA,    MICROSCOPYj    ETC.  1015 

The  explanation  of  how  the  bacteria  reach  the  surface  is  to  be 
found  in  the  operations  of  the  earth-worms  which  bring  to  the  surface 
much  of  the  subjacent  earth  ;  in  their  casts,  as  in  the  earthy  contents 
of  their  digestive  canals,  the  germs  are  found.  The  contents  of  these 
cylinders  of  soil  when  they  are  broken  up  by  rain  and  then  scattered 
in  the  form  of  dust  become  distributed  over  the  low  plants  of  the 
pasturages,  with  the  same  fatal  effects  to  the  animals  browsing  there  as 
were  shown  above  in  the  experiments  with  infected  fodder.  The 
dangerous  state  of  the  soil  in  this  case  suggests  the  use  of  cremation 
to  destroy  the  germs. 

The  soils  most  likely  to  be  proof  against  the  transmission  of 
the  disease  would  appear  to  be  poor,  sandy,  or  calcareous,  not  damp 
ones,  which  would  be  thus  unfitted  for  worms.  These  conditions 
are  found  in  the  Snvarts  of  Champagne,  where  a  poor,  shallow  soil 
rests  directly  on  chalk,  and  in  parts  of  Aveyron,  where  the  soil  is 
schistous  and  granitic,  and  in  these  places  anthrax  is  unknown. 

Anthrax— Its  Spread  and  Prevention.*  —  M.  Pasteur's  views  as 
to  the  cause  of  the  spread  of  this  disease  in  certain  countries,  viz.  by 
the  liberation  of  the  bacteria  from  the  decomposed  bodies  of  animals, 
and  their  subsequent  dispersion  by  the  agency  of  earth-worms,  culti- 
vation of  the  soil,  &c.,  are  supported  by  the  circumstances  connected 
with  an  outbreak  of  the  disease  in  a  village  in  the  department  of  the 
Jura. 

Hero  three  cows  which  had  died  of  the  disease  were  buried  at 
a  depth  of  2  metres.  At  different  times  within  the  ensuing  two 
years  the  rich  earth  and  the  worm-casts  above  the  graves  were 
examined,  and  in  all  cases  were  found  to  contain  germs  of  the  Bacillus 
anthracis,  while  earth  taken  from  a  few  metres'  distance  contained 
none. 

To  further  show  the  transmissibility  of  the  germs,  a  pen  was 
made  over  one  of  the  graves,  and  four  sheep  were  placed  in  it ; 
and  in  a  second  one,  a  few  metres  above  the  first,  were  placed  four 
more  sheep.  After  a  week  one  of  the  sheep  in  the  former  pen 
died,  and  the  cause  was  found  to  be  the  Bacillus.  The  sheep  in 
the  second  pen  remained  quite  well.  The  origin  of  the  disease  was 
evidently  therefore  in  the  cartli  infected  by  the  dead  cow. 

Another  important  question  relating  to  this  disease  is  the  possi- 
bility or  impossibility  of  2)rcvcnting  its  recurrence.  M.  Bouley  gives 
an  account  |  of  exitoriments  made  by  M.  Toussaint  on  twenty  sheep 
by  inoculating  tliem  with  a  liquid  intended  to  preserve  them  from 
antlirax.  Of  the  twenty  animals,  four  died  of  the  disease.  To  show 
the  immunity  conferred  by  inoculation,  two  of  the  surviving  sixteen 
sheep  were  again  inoculated  with  a  very  active  anthrax  solution, 
without  experiencing  any  ill  effects,  while  a  rabbit  treated  with  tho 
same  fluid  died. 

To  make  this  discovery  practically  useful  it  will  bo  necessary  to 
obtain  virus  of  such  a  strength  that  it  will  act  with  sufficient  vigour 
without  destroying  tho  animals  subjected  to  it.     M.  Chauvcau  states 

♦  '  Comptca  Ueii(lu«,'  xci.  ( l.SSO)  p.  I'lCi.  \  ll.i,!.,  p.  K)7. 


1016  KECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

that  the  Algerian  breeds  of  sheep  are  peculiarly  refractory  to  the 
disease,  only  exhibiting  when  inoculated  the  minor  signs  of  its 
action,  viz.  rise  of  temperature,  glandular  swellings,  and  low  spirits. 
The  immunity  is  carried  further  with  lambs  born  of  dams  inoculated 
in  the  last  stage  of  gestation,  for  inoculation  is  absolutely  without 
result  in  their  case. 

One  operation  therefore  effects  two  results,  the  immunity  of  the 
mother  and  that  of  the  offspring  at  the  same  time. 

M.  Pasteur,*  having  determined  to  test  independently  some  similar 
results  obtained  by  M.  Louvrier,  instituted  experiments  on  cows  to 
ascertain  the  effect  of  inoculation  with  the  bacteria  which  cause  the 
disease.  On  inoculation  of  two  cows,  each  with  five  drops  of  a  solution 
of  these  organisms  behind  the  right  shoulder,  swellings  appeared  on 
both.  In  the  one  the  swelling  disappeared — no  rise  of  temperature 
occurring  — by  the  fifth  day  after  the  operation.  In  the  other,  after 
two  days,  the  swelling  extended  to  the  belly,  the  cow  became  very 
ill,  the  temperature  rose  from  38  "8°  to  41*5°  C.  M.  Louvrier  then 
applied  his  method  of  recovery,  which  consists  of  warming  by  friction, 
and  by  subcutaneous  injection  of  terebenthine,  and  of  covering  all  the 
body  except  the  head  with  hay  soaked  in  warm  vinegar.  By  the 
fourth  day  the  temperature  had  fallen  to  39-7°,  but  the  swelling 
under  the  stomach  was  very  large,  and  the  lymphatic  glands  of  the 
thigh  hard  and  painful ;  then  the  recovery  became  pronounced,  by 
the  gradual  fall  of  temperature  and  diminution  of  the  swelling. 
Subsequent  inoculation  of  the  first  cow  produced  no  effect.  An- 
other inoculated  individual  jiassed  safely  through  the  stages  of  the 
disease  above  mentioned  without  the  aid  of  M.  Louvrier's  pallia- 
tive measures.  On  repeating  the  inoculation  upon  the  two  cows 
which  had  passed  through  the  disease  with  much  pain,  the  only 
result  observed  was  a  slight  swelling.  A  third  inoculation  produced 
no  effect  at  all. 

Thus  the  disease  once  passed  through  cannot  recur,  as  has  been 
already  proved  for  French  sheep.  A  further  experiment  shows  that  the 
method  of  M.  Louvrier  is  not  a  specific  cure  for  the  disease,  for  of 
four  inoculated  cows,  two  of  which  were  treated  by  him  and  two  not, 
one  of  each  category  died,  while  the  two  survivors  showed  no  ill 
effects  when  re-inoculated  on  the  side  opposite  to  that  of  the  first 
operation. 

The  relative  insusceptibility  to  the  disease  of  the  Algerian  breeds 
of  sheep  is  explained  by  M.  Pasteur  as  caused  by  a  vital  resistance  of 
the  constitution,  not — as  held  by  M.  Chauveau — by  the  presence  in 
the  animals  of  substances  obnoxious  to  the  bacterium ;  for  with  fowls, 
merely  cooling  them  brings  out  the  charbon.  M.  Chauveau's  facts 
as  to  the  Algerian  sheep  and  the  charbon  harmonize  well  with 
M.  Pasteur's  explanation. 

Immunity  from  Anthrax  obtained  by  Inoculation. f — M.  Tous- 
saint's  long  experience  has  led  him  to  believe  that  the  bacterium  of 
anthrax  is  not  completely  at  its  ease  when  developing  in  animals,  for 

*  '  Comptcs  Rendus,'  xci.  (1880)  p.  531.  f  Ibid.,  p.  135. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1017 

it  multiplies  tliere  by  division  only,  not  by  spores.  Some  animals  are 
more  readily  affected  by  it  than  others  (e.  g.  the  pig),  and  others 
in  youth  rather  than  in  old  age  (e.  g.  the  dog,  horse,  and  ass).  He  has 
been  able  to  prevent  its  development  in  young  dogs  and  in  sheep  by  a 
method  of  inoculation  with  spores  or  with  the  bacterium  in  its  fission- 
stage  (bacillus). 

Four  puppies  were  thus  inoculated,  and  five  were  not.  The  first 
batch  resisted  successfully  four  successive  inoculations,  while  the  non- 
vaccinated  puppies  succumbed  to  the  first  inoculation  in  from  two  to 
four  days,  showing  great  oedema  of  neighbouring  parts.  The  first 
batch  developed  slight  fever,  and  in  two  cases  slight  oedema ;  tho 
other  inoculations  produced  no  effect  on  them. 

Of  eleven  sheep  of  the  Lauragnais  race,  which  is  very  susceptible 
to  the  anthrax,  five  which  were  once  inoculated  with  the  poison  died. 
The  remaining  six  were  inoculated  by  the  preventive  method,  and  one 
died  from  the  eftects  of  a  subsequent  inoculation  out  of  two  thus 
tested.  The  other  five  were  re-vaccinated,  and  in  a  month's  time  were 
found  to  show  no  signs  even  of  illness  when  inoculated  in  various 
ways. 

M.  Toussaint  has  also  performed  experiments  of  injecting  into  the 
blood  of  healthy  sheep  blood  taken  from  an  animal  affected  with 
splenic  fever,  but  deprived  of  the  Bacillus  anthracis.  Taking  blood 
from  a  sheep  just  on  tho  point  of  death,  when  the  bacillus  has  pre- 
sumably produced  all  its  possible  eftect  upon  the  vital  fluid,  M. 
Toussaint  proceeds  to  deprive  it  of  the  living  bacillus  in  either  of  two 
ways — by  filtration,  or  by  destroying  the  vitality  of  the  organism. 
The  former  he  effects  by  mixing  the  blood  with  three  or  four  parts  of 
water,  and  then  passing  it  through  about  twelve  layers  of  ordinary 
filter-paper.  The  bacillus,  in  consequence  of  its  large  dimensions,  is 
entirely  retained  by  this  form  of  filter,  as  is  proved  by  the  fiict  tliat 
the  filtrate  no  longer  gives  rise  to  the  organism  in  a  cultivating  liquid 
or  in  a  living  animal.  Nevertheless,  if  injected  in  considerable  quantity 
into  the  circulation  of  a  healthy  sheep,  it  produces  a  true  vaccinatin"' 
influence ;  that  is  to  say,  secures  immunity  from  splenic  fever.  But 
(what  is  further  extremely  interesting),  in  order  tliat  this  cliaiige  in 
the  constitution  of  tho  sheep  may  be  brought  about,  the  lapse  of  a 
certain  time  is  essential.  If  a  vaccinated  sheep  bo  inoculated  with 
anthrax  within  a  few  days  of  the  operation,  it  will  die  of  splenic  fever  • 
but  if  from  twelve  to  fifteen  days  be  allowed  to  elapse,  complete  immu- 
nity is  found  to  have  been  produced. 

Similar  results  followed  from  the  injection  of  anthrax  blood  treated 
by  M.  Toussaint's  other  method,  which  consists  of  maintaining  it 
for  a  considerable  time  at  a  temperature  of  55°  C,  which  has 
the  ofiect  of  killing  "the  bacillus;  after  which  half  per  cent,  of 
carbolic  acid  is  added,  to  prevent  putrefaction  of  the  liquid.  Tho 
blood  treated  in  this  way  having  been  proved  to  be  free  from  living 
bacilli  by  negative  results  of  an  experiment  upon  a  rodent,  about  four 
c.  c.  are  injected  into  the  venous  system  of  a  sheep,  with  the  effect  of 
producing  the  same  protective  influence  against  splenic  fevor  as  is 
ensured  by  tlic  filtered  blood.     Tlusc  experiments  an;  still  in  pro- 


1018  RECOED    OF    CURRENT    RESEARCHETS   RELATING    TO 

gress,  but  M.  Toussaint  informs  Professor  Lister  tliat  he  has  already 
ascertained  the  existence  of  immunity  against  anthrax  for  3^  months 
in  both  sheep  and  dogs  treated  in  this  way.* 

Identity  of  Bacillus  anthracis  and  Hay-Bacillus,  t — This  has 
been  investigated  by  Dr.  H.  Buchner  of  Munich,  of  whose  observa- 
tions Professor  Lister  gives  the  following  account : — 

"It  is  well  known  that  the  Bacillus  anthracis  is  morphologically 
identical  with  an  organism  frequently  met  with  in  infusion  of  hay, 
which  may  be  termed  hay-bacillus.  Such  being  the  case,  it  occurred 
to  Dr.  Buchner  that  they  might  be  merely  one  and  the  same  organism 
modified  by  circumstances.  For  my  own  part,  I  am  quite  prepared 
to  hear  of  such  modifying  influence  being  exerted  upon  bacteria, 
having  made  the  observation  several  years  ago  that,  when  the  Bacterium 
lactis  had  been  cultivated  for  some  time  in  unboiled  urine,  it  proved 
but  a  feeble  lactic  ferment  when  introduced  again  into  milk.  Its  power 
of  producing  the  lactic  fermentation  had  been  impaired  by  residence 
in  the  new  medium.  In  the  case  before  us,  indeed,  the  physiological 
difference  between  the  two  organisms  seems,  at  first  sight,  so  great, 
as  to  forbid  the  idea  of  anything  other  than  a  specific  difference.  The 
Bacillus  antliracis  refuses  to  grow  in  hay-infusion  in  which  the  hay- 
bacillus  thrives  with  the  utmost  luxuriance  ;  and  conversely,  the  hay- 
bacillus  is  utterly  incapable  of  growing  in  the  blood  of  a  living 
animal,  whether  introduced  in  small  or  in  large  quantities.  The  hay- 
bacillus  is  remarkable  for  its  power  of  resistance  to  high  temperatures, 
which  is  not  the  case  with  the  Bacillus  avthracis.  The  latter  is 
destroyed  by  a  very  slight  acidity  of  the  liquid  of  cultivation,  or  by 
any  considerable  degree  of  alkalinity,  whereas  the  former  survives 
under  such  conditions.  Both  will  grow  in  diluted  extract  of  meat, 
but  their  mode  of  growth  difiers  greatly.  The  hay-bacillus  multi- 
plies rapidly,  and  forms  a  dry  and  wrinkled  skin  upon  the  surface, 
while  the  Bacillus  anthracis  produces  a  delicate  cloud  at  the  bottom  of 
the  vessel,  increasing  slowly. 

Nothing  daunted  by  these  apparently  essential  differences.  Dr. 
Buchner  has  laboured  with  indomitable  perseverance,  by  means  of 
experiments  carried  on  in  Professor  Niigeli's  laboratory,  to  solve 
the  double  problem  of  changing  the  Bacillus  anthracis  into  hay-bacillus, 
and  the  converse.  Having  devised  an  ingenious  apparatus  by  which 
a  large  reservoir  of  pure  cultivating  liquid  was  placed  in  communica- 
tion with  a  cultivating  vessel,  so  that  any  cultivation  could  be  drawn 
off  by  simply  turning  a  stop-cock,  and  further  cultivating  liquid 
supplied  to  the  organisms  remaining  in  the  vessel  by  a  mere  inclina- 
tion of  the  api^aratus,  Buchner  proceeded  to  cultivate  the  isolated 
Bacillus  anthracis  in  extract  of  meat  for  several  hundred  successive 
generations.  As  an  early  result  of  these  experiments,  he  found  that 
the  bacillus  lost  its  power  of  producing  disease  in  an  animal  inocu- 
lated with  it.     Up  to  this  point  he  is  confirmed  by  Dr.  Greenfield,^ 

*  Cf.  'Brit.  Med.  Journ..'  loc.  cit. 

t  SB.  k.  Bay.  Akad.  Wiss.,'  1880,  pp.  3G8-413,  and  Prof.  Lister's  Address, 
loc.  cit. 

%  See  this  Journal,  ante,  p.  83S. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1019 

who  has  found  that,  when  the  Bacillus  anthracis  is  cultivated  in 
aqueous  humour,  after  about  six  generations  it  loses  its  infective 
property.  Then  as  Buchner's  experiments  proceeded,  the  appearance 
of  the  growing  organism  was  found  to  undergo  gradual  modification. 
Instead  of  the  cloud  at  the  bottom  of  the  vessel,  a  scum  began  to  make 
its  appearance — at  first  greasy-looking  and  easily  broken  up — consti- 
tuting, so  far  as  appearances  went,  an  intermediate  form  between  the 
two  organisms  ;  and  in  course  of  time  the  scum  became  drier  and 
firmer,  and  at  length  the  modified  Bacillus  anthracis  was  found  to  be 
capable  of  growing  in  an  acid  hay-infusion,  and  to  present  in  every 
respect  the  characters  of  the  hay-bacillus. 

The  converse  feat  of  changing  the  hay-bacillus  into  the  Bacillus 
anthracis  proved  very  much  more  difiicult.  A  great  number  of  ingeni- 
ous devices  were  adopted  by  Buchncr,  who  was,  nevertheless,  con- 
tinually baflled,  till  at  last  he  attained  success  in  the  following 
manner.  Having  obtained  the  blood  of  a  healthy  animal  under  anti- 
septic precautions,  and  dcfibrinated  it  also  antiseptically,  and  having 
arranged  his  apparatus  so  that  the  pure  dcfibrinated  blood,  which  was 
to  be  the  cultivating  medium,  should  be  kept  in  constant  movement, 
so  as  to  continually  break  up  the  scum,  and  also  keep  the  red  cor- 
puscles in  perpetual  motion  so  as  to  convoy  oxygen  to  all  parts  of  the 
liquid — in  this  way  imitating,  to  a  certain  extent,  the  conditions  of 
growth  of  the  Bacillus  anthracis  outside  the  animal  body,  within  which 
the  hay-bacillus  could  not  be  got  by  any  means  to  develop — he  pro- 
ceeded to  cultivate  through  numerous  successive  generations.  A 
transitional  form  soon  made  its  apjiearance  ;  but  the  change  advanced 
only  to  a  limited  degree,  so  that  further  progress  by  this  method 
became  hopeless.  The  modified  form  hitherto  obtained  failed  entirely 
to  grow  when  injected  into  the  blood  of  an  animal.  On  the  contrary, 
it  was  in  a  short  time  completely  eliminated  from  the  system,  just  like 
the  ordinary  hay-bacillus.  It  had,  however,  been  observed  by  Buchner 
that  spores  had  never  been  formed  by  the  bacillus  growing  in  the 
dcfibrinated  blood ;  and  it  occurred  to  him  that,  perhaps,  if  it  were 
transferred  to  extract  of  meat,  and  induced  to  form  s])ores  there,  the 
modified  organism  might  yet  grow  in  the  blood  of  a  living  animal. 
The  carrying  out  of  this  idea  was  crowned  with  success  ;  and,  both  in 
the  mouse  and  in  the  rabbit,  Buclmcr  succeeded  by  injecting  various 
difl:erent  quantities  containing  the  ox-ganism  iu  difierent  animals. 
When  large  (quantities  wore  introduced,  the  animals  died  ra})idly  li-om 
the  merely  chemical  toxic  effects  of  the  injected  liquid ;  but  in  some 
instances,  after  the  period  for  tliese  primary  efiects  had  passed,  a  fatal 
disease  supervened — attended,  as  in  autlirax,  with  great  swelling  of 
the  spleen,  tlie  blood  of  which  was  found  i)eopled  as  in  that  affection 
with  newly  fcjrmed  bacilli ;  and  the  s])leens  affected  iu  this  way  were 
found  to  communicate  anthrax  to  healtliy  animals,  just  like  those  of 
animals  which  had  died  of  ordinary  splenic  fever. 

Supposing  these  results  to  bo  trustworthy — and  the  record  of  them 
bears  all  the  stamp  of  autlionticity — I  need  scarcely  point  out  their 
transcendent  importance  as  bearing  upon  the  origin  of  infective 
diseases,  and  their  modifications  as  exhibited  in  ej)itloniic8." 


1020  KECOED   OF    CUERENT    EESEARCHES   EELATING    TO 

Bacteria  in  Ear-disease,  &c.* — M.  B,  Loewenberg  has  discovered 
in  abscesses  of  the  auditory  meatus  the  same  microscopic  orgauism 
(micrococcus)  found  by  M.  Pasteur  in  surface-boils.  He  regards  the 
multiplication  of  boils  on  any  individuals  to  be  due  to  what  he  calls 
"  auto-contagion,"  or  the  spread  of  matter  from  an  open  boil  over 
other  parts  of  the  body,  conveying  its  microbia  with  it,  to  deposit 
them  in  other  follicles  of  the  skin,  and  there  set  up  fresh  irritation  ; 
and,  this  granted,  the  spread  of  the  affection  to  other  individuals  is 
seen  to  be  a  probable  occurrence. 

The  treatment  of  this  disease  of  the  ear  is  that  of  cutting  through 
the  abscess  and  then  bathing  the  place  with  solutions  of  thymic  or 
boric  acid,  or  sprinkling  it  with  the  latter  acid  finely  powdered.  In 
the  case  of  general  furnnculosis,  lotions  of  boric  acid  solution  applied 
to  the  whole  body  have  been  found  to  prevent  the  formation  of  new 
boils  in  the  single  instance  in  which  the  experiment  was  made. 
With  regard  to  other  diseases  of  the  ear,  the  micrococcus  is  found  in 
great  abundance  in  cases  of  otorrhoea  where  the  ear  has  not  been 
properly  cleansed,  especially  where  a  fetid  condition  has  arisen.  In 
the  employment  of  emollients,  such  as  poultices,  in  these  cases,  the 
debris  cast  off  is  found  to  be  surrounded  by  a  coat  of  the  micrococcus; 
boils  are  often  noticed  after  a  long-continued  use  of  these  applications, 
and  so  they  may  perhaps  act  deleteriously  by  developing  the  parasite. 

"  Hysterophymes  "  of  Starch  and  Fat.f — H.  Karsten  discusses 
the  chemical  composition  of  Torula,  Bacteria,  Vibriones,  and  the  other 
inciters  of  putrefaction  and  fermentation,  which  he  does  not  regard  as 
specific  organisms,  but  as  pathological  forms  of  cells,  terming  them 
"  Amyloid-  und  Fett-hysterophymen."  Their  formation  depends, 
according  to  him,  on  the  presence  of  a  definite  organic  substance, 
soluble  in  water,  together  with  phosphoric  acid  and  its  salts,  and  of  a 
deficiency  of  nutrient  salts  in  the  superficial  layer.  The  addition  of 
sugar  to  a  butyric  nutrient  fluid  causes  the  Vihriones,  Bacteria,  Micro- 
cocci, and  Dicocci,  to  develop  into  Torula-cells. 

Carpozyma,  the  Ferment  of  Wine.;]: — In  the  recently  published 
second  volume  of  his  great  work  on  viticulture,  M,  Ladrey  describes 
the  various  ferments  associated  with  the  fermentation  of  beer  and 
wine,  enumerating  the  various  species  of  Saccharomyces  established  by 
Eeess. 

In  addition  to  these,  he  describes  another  alcoholic  ferment  which, 
according  to  Engel,  does  not  belong  to  that  genus,  but  is  a  Protomyces 
without  mycelium,  and  is  called  by  him  Carpozyma.  Engel  affirms 
that  all  fermentations  of  the  must  of  fruits  are  caused  by  the  growth 
of  a  ferment,  the  mature  cells  of  which  are  ellipsoidal  in  form,  about 
6  ^  in  length  and  3  /a  in  breadth,  the  two  ends  having  each  a  small 
protuberance  or  apiculus,  which  gives  to  the  whole  the  form  of  a 
citron.     When  vegetating  in   a   fermenting   fluid,  the   young   cells 

*  '  Comptes  Rendus,'  xci.  (ISSO)  p.  555. 

t  'Zeitsclir.  AUgem.  oesterr.  Apotheker-Verein,'  18S0.  See  '  Bot.  Centralbl.,' 
i.  (1S80)  p.  596. 

+  Ladrey,  C,  '  Traite'  de  viticulture  et  d'oenologie,'  2">"  ed.,  toine  ii.  Paris, 
1S80.     See  '  Bot.  Centralbl.,'  i.  (1880)  p.  718. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1021 

always  appear  at  tliese  small  protuberances,  and  nowhere  else.  Most 
commonly  they  have  at  first  the  form  of  a  small  spherule ;  and  not 
till  one  of  them  has  attained  one-half  its  full  size  does  the  second 
appear  at  the  opposite  end;  much  less  frequently  the  two  appear 
simultaneously  at  opposite  ends  of  the  mother-cell.  Reess  did  not 
succeed  in  inducing  this  ferment  to  produce  spores.  Engel  was  more 
fortunate,  and  discovered  that  the  mode  of  fructification  was  very 
different  from  that  of  Saccharomyces,  closely  resembling  that  of  Pro- 
tomyces. 

Engel  gives  the  following  diagnosis: — Carpozyma  n.  gen. — Vege- 
tative cells  isolated,  producing  buds  at  their  poles,  which  soon  become 
detached  ;  theca  spherical,  clothed  with  a  perithecium,  and  hibernating ; 
spores  numerous,  developing  very  slowly.  Solitary  species,  C.  apicu- 
latum  Engel. — Vegetative  cells  ellipsoidal,  terminated  at  their  poles 
by  two  projecting  mamillfe,  which  give  them  a  resemblance  to  a 
citron. 

Lichenes. 

Morphology  of  Lichens :  Endophlceal  Species  of  Polyblastia ; 
Epiphora ;  Magmopsis.*— A.  Minks  is  carrying  out  a  series  of  minute 
morphological  observations  to  assist  in  determining  the  yet  unsettled 
points  in  the  structure  of  lichens. 

1.  In  his  monograph  of  the  Scandinavian  Polyblastice,  T.  Fries 
separates  from  the  genus  on  the  one  hand  P.  discrepans  Lehm.  and 
Verrucaria  suhdiscrepans  Nyl.,  from  the  want  of  one  layer,  and  from 
their  parasitic  habits  on  other  crustaceous  lichens,  and  unites  them 
with  the  Endococci  among  the  Pyrenomycetes ;  on  the  other  hand, 
the  bark-dwellers  P.  lactea  Mass.,  P.  sericea  Mass.,  P.  fallaciosa 
Stizb.,  and  Verrucaria  suhccerulescens  Nyl.,  from  the  want  of  one  layer 
and  of  the  gonidia.  Minks  asserts  the  Litter  to  be  true  lichens,  as 
shown  by  the  presence  of  microgonidia  in  the  paraphyses,  asci,  and 
spores,  and  has  subjected  the  structure  again  to  careful  examination. 

The  hyjihema  of  crustaceous  lichens  is  the  forerunner  of  the 
hyplue  in  their  various  forms,  and  the  matrix  of  the  hypha?  which 
envelope  the  already  formed  groups  of  gonidia.  The  species  of  Poly- 
blastia already  named  possess,  in  addition  to  the  gonangia  as  a  form 
of  acroblastesis,  a  mesoblastesis  as  respects  the  formation  of  gonidema 
or  gonothallium.  This  form  of  racsoblastesis  occurs  in  the  midst  of 
the  course  of  the  short-celled  secondary  hyjjha^  and  begins  with  tlie 
division  of  a  smaller  number  of  its  cells  in  the  common  axis  of  the 
hyphfc,  producing  finally  a  pseudo-parenchymatous  structure,  in 
which  the  development  of  the  gonidia  takes  lAacc  from  the  micro- 
gonidia present  in  each  cell.  The  same  process  takes  place  also  in 
the  cells  of  the  hyphema,  in  the  same  way  as  in  the  hyphema  of 
Nosloc  and  Lcplogium. 

Tlio  forms  referred  to  are  united  by  the  author  into  one  species, 
without  exactly  defining  its  limits.  As  to  its  position,  he  would 
unite  the  cortical  P(i}yJ>histi<r  with  the  forms  included  under  Blasto- 
desmia,  Arrocordia,  and  Pyrrnnia  Ki'irb.,  rntlier  than  with  the  genera 

*  'Flora.'  Ixiii.  (ISSO)  pp.  120,  lO.'i. 
VOL.    III.  3    Y 


1022  RECOED   OF    CURRENT   RESEARCHES   RELATING   TO 

Arthopyrenia  and  Microthelia,  into  which  the  genus  Pyrenula  Tuck, 
must  be  separated. 

2.  With  respect  to  the  genus  of  epiphytal  lichens  Epiphora, 
established  by  Nylander,  Minks  states  that  E.  encaustica  is  a  true 
lichen,  which,  however,  in  consequence  of  unfavourable  vital  con- 
ditions, is  unable  to  attain  full  development,  and  does  not  therefore 
possess  the  characters  of  a  true  species,  still  less  of  a  distinct  genus. 

3.  The  new  genus  Magmopsis  was  considered  by  its  author  Nylan- 
der as  the  representative  of  the  peridium-type  among  the  Byssacefe. 
A  careful  study  has,  according  to  Minks,  established  the  fact  that,  in 
the  supposed  peculiar  thallus  of  Magmopsis,  Nylander  had  under  his 
eyes  a  mixture  of  three  distinct  layers.  The  altogether  lecideine 
apothecia  belong  to  Catillaria  athalUna  Hepp.,  or  a  nearly  allied 
species.  The  thallus  and  the  apothecia  of  this  are  overgrown  by 
two  other  lichen  layers,  still  in  an  early  stage  of  development.  The 
apparent  peridium-type  arose  from  the  overgrowth  of  a  hypothallus 
bearing  densely  crowded  gonocysts. 

Application  of  Pringsheim's  Researches  on  Chlorophyll  to  the 
Life  of  the  Lichen.* — Mr.  G.  Murray,  referring  to  the  suggestion 
of  Dr.  Vines  in  regard  to  Pringsheim's  researches,!  that  by  the  aid 
of  an  artificial  chlorophyll  screen  the  protoplasm  of  fungi  might  be 
excited  to  the  decomposition  of  carbonic  acid,  and  to  the  formation  of 
starch  from  carbonic  acid  and  water,  contends  that  this  experiment  is 
proceeding  naturally  in  Lichens.  In  these  organisms  we  have  the 
fungal  tissues  in  the  body  of  the  thallus,  and  the  chlorophyll  screen 
in  the  gonidial  layer;  that  is,  the  chlorophyll  is  in  one  system  of 
cells,  and  the  protoplasm,  apparently  affected  by  it,  in  another,  which 
is  in  contact.  Light  traversing  the  chlorophyll-containing  gonidial 
layer  excites  in  the  fungal  tissues  the  decomposition  of  carbonic  acid. 
In  evidence  he  adduces  the  plentiful  occurrence  of  starch,  or  rather 
lichenin — a  substance  of  the  same  chemical  composition  as  starch 
(CgHjoOg)  and  formed  from  it  by  the  action  of  the  free  acids  of  the 
plant. 

This  process,  he  considers,  tends  to  explain  the  nature  of  the  con- 
sortism  of  the  fungal  and  algal  elements  in  the  autonomous  Lichen, 
and  thus  to  support  tlie  well-known  views  of  Schwendener. 

Algae. 

Agardh's  'Morphologia  Floridearum.' — Professor  Agardh  re- 
publishes this  work  (in  Latin,  with  301  pp.)  uniform  with  and  forming 
vol.  iii.  part  2  of  his  '  Species,  Genera  et  Ordines  Algarum,'  in  8vo. 
Unfortunately  the  reader  is  referred  to  the  4to  edition  for  the  plates 
which  illustrate  the  subject,  thej  not  having  been  reproduced  with 
the  text. 

Oxyglossum,  a  new  Genus  of  Laminariace8B.| — Under  this 
name  Professor  J.  L.  Areschoug  proposes  to  establish  a  new  genus 

*  '  Joura.  Linn.  Soc.  Lond.'  (Bot.),  xviii.  (1880)  pp.  147-8. 

t  See  this  Journal,  ante,  pp.  117  and  480. 

%  '  Bot.  Notiscr,'  1880,  pp.  96-98.     See  '  Bot.  Centralbl.,'  i.  (1880)  p.  1154. 


INVERTEBRATA,    ORYPTOGAMIA,    MICROSCOPY,    ETC.  1023 

founded  on  the  species  hitherto  described  by  Suringar*  and  himself 
as  Laminaria  japonica,  and  previously  by  Thunberg  as  Fucus  sac- 
charinus.  The  following  is  his  diagnosis  of  the  genus : — Radix 
fibrosa  ;  stipes  complanatus,  evanescens  in  laminam  e  basi  acute  ovata 
et  firmiore,  lineari-lanceolatam,  fascia  porcursam,  in  apicem  juniorem 
integrum  et  non  dissolvendum  longissime  productam.  Fructificatio 
in  parte  inferiore  et  crassiore  (?). 

New  Endophytic  Alga.f — Under  the  name  Entodadia  WittrocJcii, 
N.  Wille  describes  a  new  Alga  endophytic  or  parasitic  on  two  species 
of  Ectocarpus,  E.  siliculosus,  and  E.  firmus,  in  a  fiord  in  the  neighbour- 
hood of  Christiania.  It  forms  unbranched  or  slightly  branched  rows 
of  cells  in  the  interior  of  the  cell-wall  of  the  host.  Its  cells  contain 
large  starch-grains  and  parietal  chlorophyll.  All  the  cells  may  form 
in  succession  four,  eight,  or  perhaps  a  larger  number  of  zoospores, 
which  escape  through  a  circular  opening  in  the  cell-wall. 

New  Genus  of  Oscillatorieae.:]:— In  "  Contributions  to  the  Alga  flora 
of  Wiirtemberg,"  Dr.  0.  Kirchner  describes  under  the  name  Clastidium, 
a  new  genus  of  Oscillatoriefe  belonging  to  tlie  section  Chamaesiphonca3 
(Borzi),  with  the  following  characters  : — Filaments  short,  unbranched, 
without  sheath,  firmly  fixed  at  the  base,  provided  at  the  apex  with  a 
thin,  erect,  unscgmented  bristle  ;  cells  scarcely  distinguishable  in  the 
young  state ;  afterwards  cylindrical,  finally  spherical ;  reproduction 
by  isolated  gonidia  resulting  from  the  entire  filament  breaking  up 
into  spherical  cells. 

The  only  species,  C.  setigcrum,  grows  attached  to  filaments  of 
Cladophora,  which  it  completely  covers  ;  the  bristle  is  delicate,  about 
0*05  mm.  long;  the  cell-contents  homogeneous,  pale  blue-green;  the 
entire  filament,  excluding  the  bristle,  when  mature,  0*028  to  0-038 
mm.  long,  0-0025  to  0-004  mm.  thick. 

Clastidium  is  the  only  known  genus  of  Oscillatoriea)  provided 
with  a  bristle,  which  is  formed  at  an  early  period,  and  may  be  com- 
pared to  that  of  Coleochcete  or  Bnlbochcete ;  no  hormogonia  have  been 
observed. 

Change  of  Colour  in  Oscillatorie8e.§ — P.  Eichter  states  that  too 
much  value  must  not  bo  j)laced  on  colour  as  a  distinguishing  character 
of  the  species  belonging  to  the  genera  Oscillatoria  and  Phorinidium. 
Cohn  considers  the  bright  green  colour  of  the  Phycochromacoai  to  be 
due  to  a  mixture  of  green  chlorophyll  and  blue  phycocyan.  According 
to  Richtcr,  a  deficiency  of  water  is  favourable  to  the  formation  of 
phycocyan,  and  hence  to  a  blue-green  colour,  in  consequence  of  the 
Kulubility  of  phycocyan  in  water.  The  same  species  will  exhibit 
diilbrent  colours,  according  to  the  quantity  of  water  in  which  it  grows, 
and  other  conditions. 

•  '  AlgtB  Japonicie,'  p.  21. 

t  •  Christiania  Vidcnsk.  Forlinndl.,'  1880.  Sco  '  Bot.  Centralbl..'  i.  (1880) 
p.  571». 

X  '  Jahreshpftc  Vcr.  fiir  vatorl.  Nnturk.  Wiirtteniberg,'  xxxvi.  (1880)  p.  1;"). 
§  '  Hot.  Centralbl.,'  i.  (ISSO)  p.  (505-7. 

3  Y  2 


1024  RECORD    OF    CURRENT    RESEARCHES   RELATING    TO 

Cell-division  in  Conferva  and  CEdogonium.* — N.  Wille  has 
observed  the  mode  of  cell-division  in  a  large  newly  discovered  variety 
of  Conferva  amoena  which  he  calls  var.  norvegica.  The  cell-wall 
appears  to  be  composed  of  pointed  H-shaped  pieces,  a  smaller  and  a 
larger  one  always  alternating,  the  latter  enclosing  the  margins  of  the 
former  like  the  lid  of  a  box.  The  whole  row  is  surrounded  without 
and  within  by  a  dense  substance  which  binds  it  together.  The 
division  of  the  cells  is  preceded  by  the  formation  of  a  watery  layer, 
which  may  be  termed  the  "  lengthening-layer,"  in  the  interior  of  the 
dense  layer  which  lies  on  the  inner  side  of  the  cell.  The  further 
development  of  this  lengthening-layer  causes  the  older  pieces  of  cell- 
wall  to  become  separated  from  one  another.  At  this  period  the 
nucleus  divides,  becoming  first  of  all  constricted  in  the  middle,  and 
then  breaking  up  into  two  parts,  which  at  once  begin  to  separate  from 
one  another,  jiarietal  protoplasm  at  the  same  time  collecting  between 
them.  The  new  septum  then  develops  from  the  lengthening-layer 
in  the  form  of  a  circular  ridge  inside  the  cell,  the  central  part  being 
perhaps  formed  at  the  time,  and  divides  it  into  two  halves.  When 
fully  developed  cells  open,  the  cell-wall  breaks  up  into  H-shaped 
sharp-pointed  pieces  ;  but  when  cells  open  while  in  the  act  of  division, 
the  ends  of  these  pieces  are  united  by  a  membrane,  since  in  this  case 
the  line  of  dissociation  does  not  pass  through  the  innermost  denser 
layer. 

Conferva  flaccosa,  Ag.  (3  Norm  Semlice  can  multiply  by  the  cells 
losing  their  connection  with  one  another. 

Cell-division  in  CEdogonium  is  thus  described  by  the  same  writer. 
The  ring  of  cellulose  is  here  the  "  lengthening-layer,"  and  is  formed  in 
the  same  way  as  the  corresponding  layer  in  Conferva  ;  but  its  subse- 
quent development  differs  in  the  greater  firmness  of  the  cell-wall.  In 
occasional  abnormal  instances  the  development  resembles  that  in  Con- 
ferva. While,  in  Conferva,  the  lengthening  layer  and  the  septum  are 
closely  united  with  one  another,  in  CEdogonium  they  are  quite  distinct. 
In  the  latter  the  septum  is  fonned  simultaneously  in  a  disk  of  parietal 
protoplasm,  which  is  no  doubt  produced  by  the  activity  of  the  nucleus, 
this  latter  appearing  to  divide  like  that  of  Conferva.  The  ring  of 
cellulose  expands  to  a  new  piece  of  cell-wall,  by  which  means  the 
young  septum  is  raised  up  by  the  pressure  in  the  lower  daughter- 
cell,  uniting  them  in  its  growth  with  the  wall  of  the  mother-cell. 

Incrusted  Filaments  of  Conferva. f — Professor  Hanstein  has  ob- 
served, in  a  ditch  at  Godesberg,  which  receives  the  very  warm  water 
of  a  steam  engine,  as  well  as  water  impregnated  with  iron,  conferva- 
filaments  enclosed  in  a  thicker  or  thinner,  continuous  or  interrupted, 
ochre-coloured  envelope.  The  filaments  were  stift"  bristles  or  knotty 
moniliform  threads.  The  interrupted  envelopes  Hanstein  believes  to 
have  been  originally  continuous,  but  to  have  been  ruptured  and  separ- 
ated by  subsequent  extension  of  the  filaments.     Both  the  girdles  and 

*  '  Christiania  Vidensk.  Forliandl.,'  1880.  See  '  Bot.  Ceutralbl.,'  i.  (1880) 
p.  579. 

t  'SB.  niederrhein.  Ges.  Bonn,'  v.  (1878),  p.  78.  See  '  Hedwigia,'  xix. 
(1880)  p.  118. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1025 

the  continuous  tubes  are  always  enclosed  by  an  evident  membrane,  and 
the  deposit  always  consists  of  a  number  of  concentric  layers,  which 
are  again  sejiarated  by  membranous  division-walls.  Isolated  streaks 
or  warts  indicate  the  commencement  of  the  deposit.  On  treatment 
with  potassium  ferrocyanide,  with  addition  of  hydrochloric  acid,  the 
iron  is  dissolved,  and  Prussian  blue  formed.  The  deposits  first  appear 
as  minute  dots  between  the  inner  and  outer  membranes,  which  soon 
unite ;  or  the  formation  begins  between  the  layers  of  the  septa  of  two 
cells,  forces  itself  outwards,  and  spreads  in  the  form  of  a  sheatli  in 
both  directions  of  the  superficies  of  the  cell,  raising  up  the  outermost 
layer.  The  formation  of  several  concentric  layers  may  be  the  result 
of  a  repeated  raising-up  of  successive  layers  of  cell-wall. 

Kiitzing  has  described  these  incrusted  confervae  as  Psichohormium 
(according  to  Hanstein  Psichormium),  but  Hanstein  does  not  consider 
the  genus  one  that  can  be  retained,  and  proposes  to  combine  the  species 
Psichormium  glohuliferiim,  didans,  approximatum,  incBquale,  and  fus- 
cescens  under  the  name  Conferva  martialis,  imtil  a  more  full  investiga- 
tion has  been  made  of  their  mode  of  reproduction.  Hanstein  states 
that  propagation  has  been  efiected  by  disintegration  of  the  cells. 
Besides  the  iron  hydrate  there  is  also  abundance  of  calcium  carbonate 
lying  loose  on  the  surface  of  the  filaments  or  between  them,  which, 
however,  does  not  form  an  organic  envelope,  and  is  similar  to  that 
which  occurs  in  CEclogonium  ;  it  is  only  attached  externally.  Klitziug's 
figures  of  P.  antliare,  cinereum,  puhescens,  &c.,  appear  to  represent  such 
incrustations. 

Hanstein  explains  the  phenomenon  by  supposing  that  these  confervte, 
when  in  active  growth  and  greedy  for  carbonic  acid,  take  up  the  iron 
dissolved  by  the  carbonic  acid  in  the  water,  deprive  the  carbonate  of 
its  carbonic  acid,  and  deposit  beneath  its  outermost  layer  of  cell-wall 
the  iron  which  has  been  oxidized  by  the  nascent  oxygen,  while  the 
calcium  carbonate,  deprived  of  one  atom  of  carbonic  acid,  usually 
remains  external,  but  sometimes  in  the  internal  spaces. 

Germination  of  the  Zoospores  of  (Edogonium.* — Wille  confirms 
in  all  essential  points  Poulsen's  description,  adding  a  few  new  observa- 
tions. The  ring  is  formed  at  the  apex  of  the  cells,  and  is  drawn  out 
upwards  in  a  longitudinal  direction.  The  red  eye-spot  can  be  made 
out  almost  until  the  first  division  takes  place.  A  large  number  of 
the  germinating  plants  do  not  multiply  by  division,  but  again  form 
zoospores,  which  separate  and  have  a  long,  extended,  but  unbranchcd 
or  only  slightly  branched  root-portion.  Those  whicli  divide  are 
cither  firmly  seated  or  have  a  unieh-branchcd  attachment-disk,  which 
is  formed  when  the  gi'owing  root-portion  meets  with  an  impediment 
by  which  gi-owth  in  length  is  prevented.  The  j)urietal  protoplasm 
then  continues  in  an  active  state,  causing  a  lateral  cximnsion  of  tlio 
radicular  extremity,  and  frequently  forming  new  branches,  altliough 
growth  usually  ceases.  The  formation  of  cellulose  ajjpears  to  be  pro- 
portionate to  the  mass  of  the  parietal  protoplasm. 

*  'Christianiu  Vidcnsk.  Forhandl.,'  1880.  Sec  '  Bot.  Ccutralbl.,'  i.  (1880) 
p.  581. 


1026     RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

Codiolum  gregarium,  A.  Br.* — Mr.  E.  M.  Holmes  records  the 
recent  identification  of  this  Alga  from  a  Briti'sli  locality  by  Dr.  Bornet, 
it  having  been  discovered  at  Teignmouth  in  1855  by  the  Rev.  R.  Cres- 
well,  one  of  the  few  British  algologists  who  have  paid  attention  to  the 
minute  algfe  growing  near  high-water  mark,  whereby  he  has  discovered 
many  species  overlooked  by  others. 

It  forms  a  scattered  velvety  growth  of  a  dark-green  colour  on  the 
vertical  surface  of  the  blocks  of  sandstone  and  Devonian  limestone 
forming  the  sea-wall,  where  it  is  liable  to  be  wetted  by  the  spray  at 
high  tide  only,  unless  the  sea  be  rough,  in  which  case  the  surf  dashes 
over  it.  Mr.  Creswell  has  found  it  throughout  the  winter,  year  after 
year,  in  the  same  place,  presenting  the  same  appearance  to  the  naked 
eye  and  the  same  characters  under  the  Microscope.  In  June  he  has 
found  full-grown  specimens  in  a  spot  where  the  plant  is  within  reach 
of  every  tide. 

Mr.  Holmes  states  his  reasons  for  considering  it  highly  probable 
that  the  "  hypnospores  "  of  Braun — the  globose  cells  which  he  believed 
to  play  the  role  of  resting-spores  and  to  preserve  the  plant  during  the 
winter  and  spring  months — are  in  fact  only  the  earliest  stage  of 
growth  of  Hormotriclmm  flaccum. 

Algse  from  the  Amazons. f — Professor  G.  Dickie  gives  a  list  of 
the  Algfe  collected  by  Professor  J.  W.  H.  Trail  during  explorations 
on  the  Amazons  and  branches. 

Of  the  total  of  102  species  and  varieties  (excluding  Diatomacese) 
the  following  are  new  : — 

BATRACHOsPERMACEa:,  TJiorea  Train.  Confervace^,  BMzoclonium 
spongiosum,  Gloeotila  nigrescens,  and  G.  aurea.  Protococcace^, 
Limnodictyon  obscurum.  Nostochace^,  Anahcena  scabra,  Cylindro- 
spermum  cceruleum,  and  C.  janthinum.  Oscillariace^,  Inactis  obscura. 
Chroococcace^,  Microcystis  ccerulea  and  M.  lobata. 

Of  the  Diatomacefe  the  names  of  188  species  and  varieties  from 
different  localities  are  given,  but  this  includes  a  number  of  duplicate 
species  found  in  more  than  one  of  the  localities  enumerated. 

Fossil  Diatoms. I — The  Academy  of  Genoa  has  published  a  paper 
by  Count  Castracane  on  the  importance  of  diatoms  in  the  formation 
of  the  earth's  crust.  Owing  to  the  indestructible  nature  of  their  test, 
the  author  believes  that  fossil  diatoms  enable  him  to  demonstrate  that 
in  the  vegetable  kingdom  "  the  fixity  of  species  is  a  constant  law." 

Dimystax  Perrieri,  new  Ciliated  Organism  containing  Chloro- 
phyll.§ — Van  Tieghem  describes  under  this  name  an  organism  com- 
municated by  M.  Perrier,  and  found  by  him  in  sea-water  from  Roscoif, 
containing  Algae  and  lower  animals,  and  again  in  a  small  laboratory 
aquarium  in  the  museum. 

It  consists  of  a  tremulous  gelatinous  mass  of  a  pure  green  colour 
and  sharply  limited  form,  spherical  or  oval,  somewhat  more  than  a 

*  '  Journ.  Linn.  Soc'  (Bot.),  xviii.  (18S0)  pp.  132-5. 

t  Ibid.,  pp.  123-32. 

X  '  Rev.  Sci.  Nat.,'  ii.  (1880)  p.  250. 

§  '  Bull.  Soc.  Bot.  France,"  xxvii.  (1880)  pp.  130-2. 


INVERTEBRATA,   CRYPTOOAMIA,    MICROSCOPY,    ETC.  1027 

centimetre  in  diameter,  and  fixed  by  a  point  of  its  periphery  to  some 
large  marine  algal.  From  a  distance  it  has  the  appearance  of  a 
Nostoc.  Exposed  to  solar  light,  it  disengages  oxygen,  and  the  green 
colouring  substance  is  therefore  chlorophyll. 

More  closely  examined  it  is  seen  that  the  mass  is  composed  of  a 
colourless  jelly,  studded  with  isolated  green  points  visible  to  the 
naked  eye,  and  sufficiently  numerous  to  give  the  characteristic  green 
colour  to  the  whole  body.  It  is  therefore  not  a  Nostoc.  If  some  of 
the  green  points  are  removed  from  the  gelatinous  mass,  they  are 
found,  when  in  a  sufficiently  advanced  stage  of  development,  to  have 
a  remarkable  constitution. 

Each  of  the  small  green  bodies  is  nearly  spherical,  and  measures 
from  0*3  to  0  •  4  mm.  in  diameter.  It  is  composed  of  very  finely 
granular  and  rather  dark  protoplasm,  uniformly  impregnated  through- 
out with  amorphous  chlorophyll.  Neither  nucleus,  vacuoles,  nor  red 
eye-spot  can  be  detected,  and  the  membrane  which  envelops  it  is  very 
delicate.  At  one  spot  which  may  be  termed  the  pole,  the  cell  bears 
a  tuft  of  vibratile  cilia,  attached  side  by  side  to  adjacent  points,  and 
endowed  with  independent  motion.  At  two  diametrically  opposite 
points  of  the  equator  is  a  small  indentation  in  the  green  matter 
through  which  passes  a  strongly  refractive  homogeneous  protoplasmic 
band  which  traverses  the  membrane,  bends  towards  the  pole  in  close 
contact  with  the  inferior  hemisphere,  and  divides  at  the  same  time  at 
its  external  border  into  a  delicate  fringe  composed  also  of  vibratile 
cilia.  Since  these  cilia  coalesce  at  their  base,  they  are  not  capable 
of  independent  movement.  The  motion  is  like  a  wave  which  is 
transmitted  gradually  from  the  outermost  to  the  innermost  cilium. 
In  their  nature  and  disposition  these  lateral  cilia  therefore  differ  con- 
siderably fnmi  those  which  compose  the  polar  tuft.  At  this  phase  of 
development  there  are  no  cilia  either  at  the  opposite  pole  or  at  any 
other  point  of  the  surface  of  the  green  grains. 

Notwithstanding  the  movements  of  these  three  tufts  of  cilia,  which 
are  often  rapid,  the  entire  body  is  in  general  immobile.  Its  centre  of 
gravity  is  so  jdaced  that,  in  a  position  of  equilibrium  on  the  slide,  all 
three  groups  of  cilia  are  visible  to  the  eye. 

At  a  more  advanced  stage,  the  polar  tuft  first  of  all  disappears 
gradually,  losing  its  cilia  one  by  one,  which  may  bo  found  detached 
in  the  surrounding  jelly,  the  pole  finally  becoming  completely  bare. 
Next,  the  two  lateral  tufts  also  disa2)pear,  apparently  by  becoming 
absorbed  in  the  general  pr()t(»i)lasm,  this  being  certainly  the  case  with 
the  band  wliich  cnnnects  them.  A  membrane,  henceforth  continuous 
and  smooth  at  all  points,  with  very  sharp  outline,  now  clothes  tho 
proto})lasmic  body,  which  has  changed  iicither  in  appearance  nor  in 
size,  two  slight  depress'ious  at  the  sides  still  indicating  the  position  of 
tho  lateral  tufts  of  hairs. 

Subsequently  a  fissi(m  takes  place  in  the  mass  following  tho  equa- 
torial plane,  and  diviiling  it  into  two  halves,  each  half  then  dividing 
a^ain  by  a  division  at  right  angles  to  the  first  ;  and  this  process  c<m- 
tinucK  until  a  family  of  sixteen  round(.d  cells  are  formed,  surrounded 
by  the  primitive  membrane.     The  division  and  multiplication  of  cells 


1028  KECORD   OF    CURRENT   RESEARCHES    RELATING   TO 

therefore  takes  place  as  in  Euglena,  at  what  may  be  termed  the  period 
of  encystment,  i.  e.  during  the  phase  of  immobility,  when  the  body  is 
entirely  destitute  of  cilia. 

In  the  next  stage,  each  of  the  new  cells  increases  in  size,  separates 
gradually  from  its  sister-cells,  becomes  clothed  with  a  delicate  cell- 
wall,  and  finally  entirely  covered  with  vibratile  cilia  inserted  inde- 
pendently side  by  side,  and  uniformly  clothing  the  whole  of  the 
surface.  It  next  begins  to  move  about,  and  at  the  same  time  secretes 
abundance  of  a  gelatinous  substance.  The  cilia  then  gradually  fall 
ofi"  in  proportion  as  the  body  grows  in  acquiring  its  ultimate  dimen- 
sions. Only  the  single  polar  tuft  of  hairs  now  remains.  Beneath 
this  bare  surface,  at  two  diametrically  opposite  points  of  the  equator, 
a  band  of  bright  homogenous  protoplasm  now  makes  its  appearance, 
which  develops  on  each  side  into  a  fringe  of  hairs  towards  the  pole. 
Thus  we  arrive  at  the  original  point  of  departure. 

At  no  period  of  development  can  the  presence  of  cellulose  be 
determined  in  the  membrane,  nor  of  starch  in  the  protoplasm,  other- 
wise the  process  of  gelatinization  proceeds  as  in  the  Nostochine^e  and 
Bacteriacese. 

Whether  this  organism  ought  properly  to  be  considered  as  belong- 
ing to  the  animal  or  to  the  vegetable  kingdom  is,  M.  Van  Tieghem 
considers,  doubtful,  and  he  adds  "  in  the  present  state  of  science  this 
question,  to  which  formerly  so  much  importance  was  attached,  seems 
to  me  devoid  of  interest." 

The  name  Dimystax  (Perrieri)  is  proposed,  to  indicate  the  secon- 
dary tufts  of  cilia  developed  after  the  first  tuft  has  almost  completely 
disappeared. 


MICEOSCOPY,  &c. 


Permanent  Microscopical  Preparations  of  Amphibian  Blood.* — 

Mr,  S.  H.  Gage  says  that  the  very  excellent  method  of  drying  the  cor- 
puscles of  mammalian  blood  on  the  slide  is  not  applicable  to  the  much 
more  bulky  corpuscles  of  Amphibia.  The  corpuscles  of  the  latter  are 
sure  to  be  distorted  and  seamed  in  drying,  hence  various  methods  of 
preserving  the  corpuscles  moist  have  been  tried  with  varying  success. 
The  following  very  great  modification  of  the  method  proposed  by 
Ranvier  in  his  treatise  on  histology  f  has  been  in  use  for  some  time 
in  the  Anatomical  Laboratory  of  Cornell  University,  and  has  given 
uniformly  excellent  results.  Preparations  made  three  years  ago  are 
quite  as  good  as  at  first. 

Three  or  four  drops  of  fresh  blood  are  allowed  to  fall  into  10  cc. 
of  normal  salt  solution  (common  salt  750  milligrams,  water  100  cc), 
preferably  contained  in  a  high  narrow  vessel  like  a  graduated  glass  or 
beaker.  The  mixture  of  blood  and  salt  solution  should  be  well 
agitated,  and  then  100  cc.  of  a  saturated  aqueous  solution  of  picric 

*  '  Am.  Nat.,'  xiv.  (1880)  pp.  752-3. 

t  'Traite  technique  d'Histologie,'  i.  (1875-78)  p.  195. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1029 

acid  added  with  constant  stirring.  After  the  corpuscles  have  settled, 
as  much  of  the  supernatant  liquid  as  possible  is  poured  off,  and  in  its 
place  is  put  about  an  equal  volume  of  normal  salt  solution.  The  cor- 
puscles are  allowed  to  settle,  the  liquid  poured  off,  and  another  volume 
of  salt  solution  added.  This  is  continued  until  the  salt  solution 
acquires  only  a  faint  yellow  tinge.  The  use  of  the  salt  solution  is, 
first,  to  dilute  the  blood  in  order  to  avoid  distortion  of  the  corpuscles, 
and  second,  to  wash  away  the  picric  acid,  so  that  the  subsequent 
staining  will  be  more  satisfactory. 

After  pouring  off  the  last  salt  solution,  there  is  put  in  its  place  10 
cc.  of  a  mixture  of  five  parts  of  Frey's  carmine  and  ninety-five  parts  of 
picrocarmine.  The  corpuscles  will  stain  in  from  one  to  fifteen  hours. 
A  drop  of  the  agitated  mixture  should  be  examined  occasionally,  to 
ascertain  when  the  staining  is  sufficient.  The  nucleus  should  be 
deep  red,  and  the  body  of  the  corpuscle  yellow  or  pinkish. 

When  the  staining  is  completed  as  much  stainer  as  possible  should 
be  poured  off,  and  in  its  place  10  or  15  cc.  of  acid  glycerine  (glycerine 
100  cc,  acetic  or  formic  acid  1  cc).  This  mixture  of  corpuscles  and 
glycerine  may  be  jilaced  in  a  bottle  and  used  at  any  time,  it  being 
simply  necessary  to  agitate  the  mixture  slightly  or  to  take  up  some  of 
the  sediment  with  a  pipette  and  mount  it  precisely  as  any  other 
glycerine  preparation. 

The  process  consists,  therefore,  of  these  five  steps  : — 

1.  The  fresh  blood  is  first  diluted  with  about  fifty  times  its  volume 
of  normal  salt  solution.  2.  To  this  diluted  blood  is  added  ten  times 
as  great  a  volume  of  a  saturated  aqueous  solution  of  picric  acid.  3. 
The  picric  acid  is  washed  away  with  normal  salt  solution.  4.  The 
corpuscles  are  stained  with  picrocarmine,  or  a  mixture  of  this  and 
Frey's  carmine.  5.  They  are  preserved  in  acid  glycerine,  and  may  be 
mounted  for  the  Microscope  at  any  time. 

Preparing  and  Mounting  Wings  of  Micro-Lepidoptera.*— Mr. 
C.  H.  Fernald  describes  a  method  by  which  the  wings  of  the  micro- 
lepidoptera  can  be  prepared  so  that  the  venation  can  be  studied  under 
the  compound  Microscope,  in  a  manner  that  will  leave  no  doubt  of 
the  presence  or  absence  of  the  faintest  vein  in  the  whole  wing- 
structure. 

The  removal  of  the  scales  by  mechanical  means  he  considers  un- 
satisfactory, as  also  are  the  methods  recommended  for  bleaching  the 
wings,  described  by  Chambers  and  Dimmock.  Wlicn  mounted  dry  by 
the  latter  method,  the  scales,  although  bleached,  were  not  sufficiently 
transparent  to  show  clearly  the  more  obscure  parts  of  the  structure, 
and  when  mountctd  in  Canada  balsam,  the  entire  wing  was  rendered 
so  trans2)arent  tliat  only"  the  larger  veins  were  visible,  and  it  was  found 
to  be  extremely  difficult  to  get  rid  of  the  air-bubbles,  which  so  readily 
gather  midtir  the  concave  portions  of  certain  minute  wings. 

The  author's  metliod  consists  in  mounting  in  cold  glycerine  ;  after 
having  been  bleached  by  Dimniock's  method  (which,  for  bleaching,  is 

♦  'Am.  Mnn.  ISIicr.  Jour.,'  i.  (I8S0)  p.  172.  (Paper  read  before  the  Sub- 
section of  Microscopy  of  the  Am.  Assoc.  Adv.  Sci.) 


1030  RECORD   OF    CURRENT    RESEARCHES    RELATING    TO 

to  be  recommended),  the  wings  are  transferred  to  the  slide  direct  from 
the  water  in  which  they  are  washed,  then  allowed  to  dry  (sometimes 
hastened  by  holding  the  slide  over  the  flame  of  a  lamp)  ;  and,  when 
quite  dry,  a  drop  of  glycerine  is  to  be  added,  and  the  cover  at  once  put 
on.  When  the  glycerine  has  penetrated  around  the  edges  so  as  to 
completely  saturate  portions  of  the  wing,  the  scales  at  once  become 
transparent,  and  the  structure  is  clearly  apparent. 

By  holding  the  slide  over  the  lamp  till  ebullition  takes  place,  the 
glycerine  will  be  found  to  replace  the  air  under  the  concave  portions 
of  the  wings,  without  any  injury  to  the  structure  ;  and  even  in  those 
refractory  cases  when  the  glycerine  has  been  allowed  to  boil  for  a 
considerable  length  of  time,  no  injury  was  found  to  be  done  to  the 
wing-membrane. 

Microscopical  Investigation  of  Wood. — The  Vienna  Academy 
propose  as  the  subject  for  the  Baumgartner  prize  of  1000  florins, 
"  The  microscopical  investigation  of  the  wood  of  living  and  fossil 
plants."  By  such  investigation,  and  the  comparison  of  all  known 
recent  and  fossil  woods,  it  is  desired  to  ascertain  characters  whereby 
it  will  be  possible  to  determine  the  genus  and  species  with  certainty 
from  microscopical  sections.  Papers  must  be  sent  in  before  Decem- 
ber 31st,  1882,  and  the  prize  will  be  awarded  at  the  anniversary 
meeting  in  1883. 

Permanent  Preparations  of  Plasmodium.* — Two  methods  are 
already  known  for  making  permanent  preparations  of  the  motile  or 
naked  protoplasmic  stage  of  the  Myxomycetes  ;  the  older  one  being  to 
dry  the  extended  plasmodium,  and  the  newer,  to  harden  it  with  osmic 
acid.  Both  these  methods  are  defective,  for  osmic  acid  changes  the 
colour  of  the  protoplasm,  and  drying  causes  it  to  shrink  as  well  as  to 
change  colour. 

Mr.  S.  H.  Gage  gives  the  following  as  a  simple  and  efficient 
method  of  extension  and  preservation  :  Small  pieces  of  the  rotten 
wood,  on  which  the  plasmodium  is  found,  should  be  placed  on 
moistened  microscope-slides,  with  some  of  the  plasmodium  touching 
the  slides.  These  should  be  on  a  piece  of  window  or  plate  glass,  and 
over  the  whole  should  be  placed  a  bell-jar,  or  other  cover,  to  prevent 
evaporation.  After  an  hour  or  more,  the  glass  on  which  the  slides 
rest  should  be  lifted  up  to  see  whether  the  plasmodium  has  crawled 
out  upon  any  of  the  slides.  If  any  of  the  slides  are  satisfactory,  lift 
off  the  bell-jar,  and  remove  the  pieces  of  wood  from  the  slide,  the 
Plasmodium  remaining.  The  slide  should  then  be  put  very  gently 
into  a  mixture  of  equal  parts  of  a  saturated  aqueous  solution  of  picric 
acid  and  95  per  cent,  alcohol ;  it  should  be  removed  in  fifteen  or  twenty 
minutes,  and  placed,  for  about  the  same  length  of  time,  in  95  per 
cent,  alcohol ;  it  may  then  be  mounted  in  Canada  balsam  in  the 
usual  way,  but  without  previous  clearing.  The  picric  acid  stiffens  the 
protoplasm  almost  instantly,  but  does  not  shrink  it ;  the  alcohol 
removes  the  water,  and  allows  of  Canada  balsam  mounting. 

*  'Am.  Mon.  Micr.  Journ.,'  i.  (1880)  pp.  173-4.  (Paper  read  before  the 
Sub-section  of  Microscopy  of  the  Am.  Assoc.  Adv.  Sci.) 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1031 

The  method  is  especially  good  for  the  yellow  plasmodium,  as  the 
colour  is  precisely  that  of  the  picric  acid  solution.  If  white  Plas- 
modium is  to  be  mounted,  it  should  be  soaked  in  2.5  per  cent,  alcohol, 
to  remove  the  yellow  colour  of  the  picric  acid,  before  anhydrating  it 
with  strong  alcohol.  Experiments  have  not  been  tried  with  plasmo- 
dium of  purple  and  other  colours  to  determine  successful  methods 
of  preservation,  but  some  slight  modification  of  the  above  is  confi- 
dently expected  to  succeed. 

Preparation  of  Green  Algae.*— Last  summer  Prof.  0.  Nordstedt 
collected  at  Jonkoping  the  rare,  and  in  many  respects  interesting, 
alga,  SphcBroploea  annulina.  This  alga  has  the  chlorophyll  in  the 
sterile  cellules  arranged  in  transversal  bands  or  rings.  As  he  tried 
to  dry  them,  he  found  that  the  rings  were  destroyed  by  getting  dry. 
He  repeatedly  tried  to  obtain  good  microscopical  preparations  by  using 
*'  liquor  HantzschifB,"  as  well  as  acetate  of  potassium ;  but  when 
unsuccessful,  he  applied  warmth.  He  put  a  small  bottle,  containing 
the  alga  in  water,  on  a  black  object,  and  exposed  it  to  strong  sunlight 
for  a  couple  of  hours.  When  the  alga  afterwards  was  dried,  the  rings 
proved  to  be  pretty  well  preserved  ;  when  afterwards  heated  by  a 
spirit  lamp,  the  thermometer  indicated  that  the  rings  when  boiled 

h  minute  at  35°-40°  Ccls.         Did  not  keep,  or  were  very  badly  preserved. 
Wiien  boiled  5-10  minutes! 

at  45°  Cels.,  §  minute  at  >     The  rings  kept  very  well. 

50°-98°Cel3 ) 

10   minutes   at    GO-   Cels.,     j"^'?^  ""?'  Tf  ^T'^'lf  ^'T  *V  "^•'?' 
2  minutes  at  98°  Cels.  j     tiie^'celTule      °       ''^  "  ''^"""''"^^ 

It  appears  to  be  most  convenient  for  the  purpose  to  use  40^-50°  Cels. 
during  about  two  minutes. 

In  the  Spirogyra  tlie  chlorophyll-bands,  when  the  plant  was  boiled, 
also  kept  tolerably  well ;  ho,  therefore,  has  often  applied  heat  in  pre- 
paring them.  The  different  species  seem  to  require  different  degrees 
of  heat. 

Slides  from  the  Naples  Zoological  Station.  —  A  provisional 
priced  catalogue  of  the  microscopical  preparations  issued  by  the 
Zoological  Station  at  Naples  t  has  now  been  published.f  It  includes 
4  different  preparations  of  Protozoa,  33  of  Cadenterata,  49  of  Echino- 
dermata,  33  of  Vermes,  57  of  Arthropoda,  54  of  Mollusca,  and  193  of 
Vertobrata. 

The  list  is  prefaced  by  an  explanatory  note  by  Dr.  A.  Dohrn,  tho 
Director  of  the  Station,  in  which  he  points  out  that  tho  microscopical 
preparations  which  have  liitlicrto  been  sold  "  have  only  in  rare  cases  a 
true  8ci(!ntitic  value.  For  tliis  they  must  not  only  be  prepared  by  hands 
well  skilled  in  the  t(;i-lmicul  processes,  but  thero  must  also  bo  tho 
understanding  of  scientific  prol)lenis  and  points  of  view,"  so  that  tho 
preparations  may  exhibit  just  those  jiuints  which  ai-o  of  importance 

*  'Grovilloa,'  ix.  (ISSO)  pp.  .S7-8  (from  'I3ot.  Notiser'). 

t  See  this  Journal,  nntc,  p.  700. 

X  '  MT.  Zool.  Stat.  Nenpel,'  ii.  (1880)  pp.  238-53. 


1032 


RECORD   OF    CURRENT    RESEARCHES    RELATING    TO 


scientifically.  The  slides  are  preparer!  under  the  superintendence  of 
Mr.  F.  Meyer  of  Leipzig,  who  at  Dr.  Dohrn's  request  undertook  this 
department.  They  are  of  the  ordinary  English  size,  and  their  price 
varies  from  1  to  10  francs. 

Aeroscopes.* — In  his  studies  on  the  microscopic  organisms  con- 
tained in  the  atmosphere,  M.  P.  Miquel  describes  two  forms  of 
aeroscopes  in  use  at  the  Montsouris  Observatory  for  collecting  such 
organisms. 

M.  Miquel  objects  to  Dr.  Maddox's  "  aeroconiscope,"  f  that  the 
quality  of  air  passing  during  each  experiment  cannot  be  calculated, 
so  that  the  statement  of  the  number  of  germs  collected  has  no  definite 
signification.  In  his  opinion,  it  is  preferable  to  make  use  of  apparatus 
capable  of  acting  in  all  weathers,  during  rain  and  squalls  as  well  as  in 
fine  weather. 

Fig.  105  represents  his  "  aeroscope  a  aspiration,"  which  is  composed 
essentially  of  two  parts — the  bell  A,  which  is  solidly  fixed  at  2  metres 
from  the  ground,  and  the  cone  B,  which  is  screwed  to  A.  The  former 
has  an  aspiring  tube  placed  in  communication  with  a  trumpet,  and  the 


FiQ.  106. 


Fig.  105. 


latter  has  at  its  upper  part  a  very  fine  aperture,  by  which  the  air  is 
directed  to  the  centre  of  a  thin  glass  plate  smeared  with  a  mixture  of 
glycerine  and  glucose.  This  plate,  which  is  kept  in  a  horizontal 
position,  may  be  brought  nearer  to  the  summit  of  the  cone,  or  vice 
versa.  The  air  aspired  by  the  trumpet,  after  having  passed  through 
the  apparatus,  is  received  in  a  meter,  which  measures  its  volume 
exactly. 

A  second  instrmnent  ("  aeroscope  a  girouette  ")  is  shown  in  Fig.  106. 
It  operates  by  the  action  of  currents  of  air,  and  is  used  only  to 
analyze  the  air  qualitatively  when  the  other  form  cannot  be  employed. 
Like  the  apparatus  of  Drs.  Maddox  and  Cunningham,  it  is  light  and 
portable,  but  in  the  same  time  gives  100  times  as  many  germs.  It  is 
in  the  form  of  an  S,  and  consists  of  the  chambers  B  (united  to  a 
vane,  so  that  the  upper  bell-shaped  aperture  is  kept  constantly 
opposite  to  the  wind),  and  A  carrying  a  thin  glass  plate  and  a  conical 

*  '  Brebissonia,'  ii.  (1880)  p.  147. 
t  '  Mod.  Micr.  Journ.,'  June,  1870. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1033 


diaphragm,  and  having  its  lower  aperture  turned  in  the  direction  of 
the  currents.  The  apparatus  set  upon  a  vertical  axis  is  acted  upon 
by  the  feeblest  currents.  A  Robinson  anemometer  serves  to  measure 
the  velocity  of  the  air  during  the  experiment,  and  to  estimate 
approximately  the  volume  which  has  passed  through  the  apparatus. 

Both  forms  were  originally  constructed  of  glass,  but  are  now 
made  of  copper  nickelled. 

Microscopical  Appearance  of  the  Valves  of  Diatoms.* — This 
paper  by  Mr.  Julien  Deby  is  written  with  the  view  of  enabling  micro- 
scopists  more  readily  to  interpret  the  appearances  presented  by  diatoms 
as  seen  under  the  Microscope,  which  is  often  very  difficult  with  trans- 
mitted light.  By  an  attentive  examination,  however,  of  the  details, 
"  even  the  most  incomprehensible  problems  will  be  resolved  as  if  by 
enchantment." 

Taking  Niti^chia  as  the  first  type,  the  author  divides  the  different 
forms  into  two  principal  divisions — those  in  which  the  two  sections  of 
a  valve  meet  at  an  acute  angle,  and  those  which  meet  at  an  obtuse 
angle,  each  of  which  divisions  may  have  the  valve-sections  plane  or ' 
curved.  Tliese  four  divisions  may  each  be  subdivided  into  three  others, 
according  as  the  midrib  is  central,  normally  excentric,  or  submarginal 
(that  is,  with  one  of  the  valve-sections  nearly  obsolete). 

The  author  then  gives  diagrams  of  the  appearances  of  various 
forms,  of  wliich  we  can  only  subjoin  one — Fig.  107  [sm.,  im.,  upper 
and  lower  midrib;  o,  connective).  This 
shows  a  Nitschia  with  valves  whose  two 
sections  form  an  acute  angle,  and  witli 
an  excentric  midrib.  Taking  the  line 
which  represents  the  surface  of  either 
of  the  larger  sections  as  a  horizontal, 
and  drawing  tlie  perpendiculars,  we 
shall  have  the  true  microscopical  pro- 
jection of  the  diatom  when  viewed  from 
the  upper  or  under  side  respectively. 

The  author  considers  tliat  it  is 
necessary  to  pay  more  attention  to 
details  tlian  has  liitherto  been  the  case 
in  this  difBcult  genus,  and  in  defining 
every  species  (1)  to  describe  the  general 
form  of  the  frnstule,  and  tlie  relations 
of  the  length  of  the  two  sections  of  tlie 
valves  to  the  breadth  ;  (2)  to  indicate 
the  position  of  the  midrib  by  reference 
to  the  imaginary  central  line  of  tin 
valve,  that  is  to  indicate  the  relative 
size  of  the  two  sections ;  (3)  to  deter- 
mine the  number  of  stria?  by  reference  to  tlic  nodult-s  of  tlio  midrib; 
(1)  to  count  the  siliceous  grains  of  the  midrib,  the  striie  of  tlio  valve 
sections,  and  the  number  of  points  per  stria  ]>er  micro-millinietro  ;  (.'"))  to 
indicate  if  the  valve  is  acute  or  obtuse,  and  its  sections  plane  or  curved. 
*  Sep.  rcpr.  '  Ann.  Soc.  n,!;;.  Micr.,'  v.  (1880),  Mt-ni.,  IH  pp.  aii.l  20  figs. 


Fio.  107. 


1034  RECORD   OF    CURRENT   RESEARCHES   RELATING   TO 

Cleaning  Diatoms  with  Soap.* — Dr.  H.  Stolterfoth  having  tried  to 
clean  some  of  the  Welsh  deposits  hy  the  common  acid  process,  which 
gave  very  poor  results,  even  alkalies  destroying  the  valves  of  the 
larger  Surirellce  before  they  were  free  from  the  dirt,  boiled  them  in 
soap  and  water  for  about  an  hour,  with  excellent  results.  The  process 
is  also  applicable  to  all  kinds  of  fresh-  and  salt-water  deposits. 

The  method  is  this :  Place  in  a  test-tube  (6  inches  by  1  inch)  a 
portion  of  the  earth,  about  ^  inch  in  depth,  and  pour  in  water  till  the 
tube  is  one-fourth  full ;  into  this  drop  a  piece  of  common  yellow 
soap,  about  the  size  of  a  small  pea,  and  boil  gently  over  a  lamp.  The 
solution  should  be  examined  under  the  Microscope  from  time  to  time, 
by  taking  out  a  drop  with  a  dipping-tube,  and  putting  it  on  a  slide  ;  as 
soon  as  it  is  seen  that  the  valves  are  clean,  fill  up  the  test-tube  with 
cold  water,  and  let  it  stand,  then  wash  in  the  usual  way,  until  all  trace 
of  soap  is  removed. 

In  pouring  on  the  cold  water  after  the  boiling,  the  solution  is 
quite  fluid  as  long  as  the  water  is  warm.  During  this  time  the  diatoms 
fall  to  the  bottom,  but,  on  getting  cold,  the  solution  assumes  a  some- 
what jelly-like  consistency,  and  holds  the  fine  particles  and  mud  in 
suspension,  and  is  a  very  useful  means  of  getting  rid  of  what  is  often 
a  great  trouble. 

In  deposits  in  which  there  is  much  organic  matter,  recourse  must 
still  be  had  to  acids  or  fire  to  destroy  this,  but  the  result  will  be  im- 
proved by  afterwards  boiling  in  soap  and  water.  The  author  has  also 
boiled  fresh  gatherings  in  soap  and  water,  and  then  burnt  on  platinum 
foil  with  good  success,  much  of  the  flocculent  matter  being  removed. 

Dr.  E.  Kaiser,  of  Berlin,  referring  to  this  paper,  says  t  that  the  pro- 
cess was  communicated  to  him  several  years  ago  from  England,  but 
that  "  it  has  very  many  defects  and  inconveniences." 

Separation  of  Heavy  Microsopic  Minerals.;}: — In  order  to  separate 
minute  particles  of  heavy  minerals,  of  diiferent  specific  gravities,  from 
each  other,  M.  Eene  Breon  proposes  to  employ  a  mixture  of  the  fused 
chlorides  of  lead  and  zinc,  the  respective  specific  gravities  of  these 
two  liquids  being  5  and  2*4,  so  that  by  properly  proportioning  the 
mixture,  any  two  minerals  of  different  specific  gravities,  but  lying 
within  the  above  limits,  can  be  separated.  The  fine  powder  to  be 
experimented  on  is  thrown  into  the  fused  chlorides  contained  in  a 
conical  glass  tube,  when  the  particles  speedily  come  to  rest,  some 
floating,  and  the  others  sunk  at  the  bottom  of  the  tube  ;  the  mass  is 
then  allowed  to  cool,  and  when  set,  the  tube  is  plunged  into  cold  water, 
thus  cracking  the  glass.  The  upper  and  lower  portions  of  the  mass 
of  chlorides  containing  the  minerals  can  then  be  removed,  and  the 
chlorides  dissolved  out  with  water  acidulated  with  hydrochloric  acid. 

Pearson-Teesdale  Microtome. —  At  the  October  Meeting  Mr. 
Washington  Teesdale  exhibited  a  small  and  convenient  form  of  micro- 

*  '  Journ.  Quek.  Micr.  Club,'  v.  (1880)  pp.  95-6. 
t  '  Bot.  Ceiitralbl.,'  i.  (1880)  p.  1213. 

%  '  Bull.  Soc.  Min.  France,'  iii.  See  '  Mineralog.  Mag.  and  Journ.  Mineralog. 
Soc.,'  iv.  (1880)  p.  129. 


INVERTEBRATA,    CRYPTOQAMIA,    MICROSCOPY,    ETC. 


1035 


tome,  for  amateur  use,  made  by  Mr.  A.  A.  Pearson,  of  Leeds.  The 
instrument  is  shown  in  Figs.  108  and  109,  and  was  thus  described  by 
Mr.  Teosdale : — 

"In  general  form  it  is  based  upon  the  Continental  model  of  Dr. 
Schieflferdecker,  of  Strassburg,*  but  it  is  more  compact,  and  small 
objects  are  more  readily  held  or  packed,  as  the  holding  or  grasping 


Fig.  108. 


Fig.  109. 


is  eflfected  by  jaws  closing  centrally  like  those  of  an  American 
chuck.  The  object  so  held  is  raised  by  a  double-threaded  screw 
of  50  per  in.,  metrically  equal  to  (but  possessing  some  advantage 
over)  one  of  25  threads  per  in.  Its  elevation  is  regulated  and  recorded 
by  a  circular  plate  and  spring  stop  catching  in  20  equal  divisions, 
each  one  of  which  indicates  an  advance  of  -^—^  in.  In  practice  I  have 
generally  found  about  ^lx)>  ^^  ^^'^  divisions  of  this  graduation,  the 
most  convenient  average  thickness  for  vegetable  sections. 

I  have  used  most  of  the  forms  of  ordinary  section-cutters  for  nearly 
twenty  years.  Some  are  ingeniously  contrived  and  good  in  theory, 
or  suitable  for  some  special  purpose,  but  have  some  practical  fault 
or  inconvenience  for  the  general  all-round  work  of  an  amateur. 
The  Strassburg  model  which  furnished  the  basis  of  the  design  of 
this,  was,  it  appeared  to  me,  an  excellent  one,  and  the  principle  of  its 
construction  sound,  inasmuch  as  the  object  was  not  irregularly  forced 
up  by  pressure  from  beneath,  but  held  firm,  and  liad  the  cutting  table 
or  guide-plate  lowered  by  screw  and  graduated  index.  Such  intelli- 
gent mechanical  aid  to  accuracy  and  facility  ought,  and  would, 
assuredly  have  obtained  favourable  recognition  and  general  adoption, 
but,  uufortiniately,  in  copies  of  it  made  and  distributed  in  England 
the  screw  was  cut  taper  in  the  lathe  (instead  of  being  cut  perfectly 
parallel  with  stocks  and  ilies),  consequently  the  instrument  was  some- 
wliat  shaky." 

*  '  Quart.  Joiirn.  Mior.  Sci.'  (1877)  p.  n.'i. 


1036 


RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 


Hailes'  Poly-microtome.* — This  instrument,  shown  in  Figs.  110 
and  111,  is  the  design  of  Dr.  W.  Hailes,  Professor  of  Histology,  &c.,  at 
Albany  Medical  College  (U.S.A.),  who  thus  describes  it: — 

This  instrument  is  designed  especially  for  use  in  the  working 


Fig.  110. 


Poly-microtome  (without  freezing  apparatus).  A,  small  well,  fitting  on 
pyramidal  bed-plate.  B,  pyramidal  bed-plate,  containing  different  sizes.  C, 
micrometer  screw.  D,  ratchet-wheel  attached  to  screw.  E,  lever  actuating 
the  micrometer  screw  by  means  of  a  pawl  engaging  in  teeth  of  ratchet-wheel. 
F,  arm,  carrying  a  dog,  which  prevents  back  motion  of  screw.  G,  regulator  for 
limiting  the  throw  of  lever,  and  consequently  governing  the  micrometer  screw. 
H,  lever-nut  for  fixing  regulator.  I,  index,  with  pointer  and  graduated  scale, 
from  ^^o  inch  to  -s-tio  iii<^h.  K,  knife  for  cutting  sections.  L,  knob  to  turn 
micrometer  screw  direct  when  pawls  are  attached.  M,  table-clamp.  T,  table  of 
microtome,  with  glass  top  to  facilitate  cutting. 

laboratories  of  medical  schools  and  colleges,  where  large  numbers 
of  sections  are  required  for  microscopical  examination.  It  may  be 
employed  as  a  simple  instrument  or  as  a  freezing  microtome,  arranged 
for  ice  and  salt — ether  spray,  phigoline,  &c. 

The  employment  of  ice  and  salt  (coarse)  is  preferred,  because  it 
costs  but  little  and  freezes  the  mass  solidly  and  quickly,  and,  if 
desired,  500  or  1000  sections  can  be  obtained  in  a  few  moments. 

*  'Science,'  i.  (1880)  p.  187.    (2  figs.) 


INVEETEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1037 


Time  of  freezing  is  about  seven  minutes,  except  in  very  warm  weather, 
when  it  requires  a  few  moments  longer.  The  instrument  does  not 
work  so  satisfactorily  in  warm  weather,  owing  to  the  rapid  melting  of 
the  surface  of  the  preparation.  It  is  absolutely  necessary  that  the 
mass  should  be  frozen  solid,  or  the  sections  cannot  be  cut  smoothly. 
An  extra  freezer  may  be  employed,  and 
while  one  specimen  is  being  cut  the  other  Fig.  111. 

may  be  frozen,  and  by  exchanging  cylinders  f 

(they  being   interchangeable)  no  delay  is  /f^^^^^^^^ 

necessary  to  its  continuous  operation.  //       _..._.7\\ 

The  art  of  cutting  is  readily  acquired,  ''"        e  'H 

and  when  the  preparation  is  frozen  it  is  the  V:;^  ----^— — '.'/ 

work  of  a  few  moments  to  obtain  several  o/'"\  '  V^}'//  /""n 
hundred  sections.  Two  hundred  sections  or  ^-r^-1il■^.f^  '^r-^-j-''l 
more,  if  desired,  can  be  made  each  minute  V-'  ~  i  |ji|H  R  >;,V 
and  of  a  uniform  thickness  of  about  ^L  of  ;  i:^^[~|jl!]i|  ^^^  i 
an  inch  (thinner  or  thicker,  from  about  |  ,l^-rj--in|l[---^l  j 
5^ViT  inch  to  about  t^^^  inch,  according  as       ciy-"-"'   ^'^^    ^.^  / 

the  pointer  is  set).    The  delivery,  ease,  and  ~"--— /> ' 

rapidity  with  which  they  can  be  cut,  must  ^ 

be  seen  in  order  to  be  appreciated.     It  is       a,  B,  tube  containing  spe- 

not  necessary   to  remove  the  sections  from  cimen,  which  is  surrounded 

the  knife  every  time,  but  twenty  or  thirty  ^y  freezing  mixture  in  tiio 

may  be  permitted  to  collect  upon  the  blade  ;  fceiver  C,  D   E,F,  revolving 

*i        T  1    J        r  ^1   3  i.1      ^     -r      I'opper,   With    wings   W,  W, 

they  he  curled  or  folded  up  upon  the  knife,  f^r  stirring  the  ice   G,  outlet 

and  when  placed  in  water  straighten  them-  for  melted  ice. 

selves  out  perfectly  in  the  course  of  a  few 

hours.    The  knife  is  an  ordinary  long  knife  from   an   amputating 

case. 

Perfectly  fresh  tissues  may  be  cut  without  any  previous  prepar- 
ation, using  ordinary  mucilage  (acaci39)  to  freeze  in,  but  most  speci- 
mens require  special  preparation.  If  preserved  in  Miiller's  fluid, 
alcohol,  &c.,  they  require  to  be  washed  several  hours  in  running 
water ;  then  according  to  the  suggestion  of  Dr.  D.  J.  Hamilton,*  the 
specimen  is  placed  in  a  strong  syrup  (sugar,  two  ounces ;  water,  one 
ounce),  for  twenty-four  hours,  and  is  removed  to  ordinary  mucilago 
aeaciaa  for  forty-eight  hours,  and  is  then  cut  in  the  freezing  micro- 
tome. 

The  sections  may  be  kept  indefinitely  in  a  preservative  fluid : 
R  glycerin®,  5iv  ;  aqua)  destil.  5iv  ;  acidi  carbolici,  gtt.  iij  ;  boil  and 
filter.     The  addition  of  alcohol  5U  is  advisable. 

Salicylic  Acid  as  a  Preservative. f — Mr.  A.  Micklc  has  had  very 
good  success  witli  salicylK;  acid  in  mounting  vegetable  preparations 
of  all  kinds.  One  diHiculty,  however,  is  that  it  dissolves  very 
8j)aringly  in  water,  and  alcohol  j)roduces  clianges  wliich  are  frequently 
undesirable.  It  is  well  known  tluit  salicylic  acid  dissolves  freely  in 
a  solution  of  borax,  and  it  is  also  familiar  to  most  persons  that  borax 

*  Soo  "  A  Now  Method  of  Prppftiing  liHrgo  Sections  of  Norvoiis  Centres  for 
Microscopicni  Fnvostigalion."— •  Journ.  Anat.  and  I'liys.,'  vol.  xii. 
t  'Am.  .lourn.  Micr.,'  v.  (1880)  p.  185  (>. 

VOL.  HI.  3  z 


1038  RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 

itself  is  quite  efficient  as  a  preservative.  It  therefore  occurred  to  him 
to  combine  them,  two  parts  of  salicylic  acid  and  one  part  of  borax 
dissolving  completely  in  half  an  ounce  of  glycerine — this  solution, 
when  mixed  with  three  parts  of  water,  forming  an  excellent  preserva- 
tive fluid  for  coarse  organisms.  More  delicate  preparations  should  be 
mounted  in  the  above  solution  diluted  with  five  parts  of  water. 

Preparations  so  mounted  are  very  durable,  and  there  is  no  danger 
of  the  salts  crystallizing  out  and  spoiling  the  object,  and,  in  addition, 
it  is  very  easily  kept  in  a  cell  of  almost  any  kind. 

Dry  "Mounts"  for  the  Microscope.* — Prof.  Hamilton  L.  Smith, 
referring  to  his  former  papei',f  in  which  he  described  the  methods 
which  he  had  found  tolerably  successful,  viz.  the  rings  made  of  shellac 
and  lampblack,  and  those  punched  out  of  gutta-percha  tissue,  further 
says  "that  the  former  appear  to  answer  quite  well,  and  the  changes  if 
any  are  very  slight,  yet  he  has  in  a  very  few  cases  observed  a 
deterioration  after  the  lapse  of  a  year  or  so,  probably  from  imperfect 
manipulation.  Although  he  has  not  observed  any  great  change  in 
the  gutta-percha  mounts,  he  is  not  certain  they  will  stand  prolonged 
use  with  immersion  objectives  without  injury.  Messrs.  Spencer  are 
decidedly  of  opinion  that  the  shellac  ring  is  the  better  for  durability  ; 
and  Mr.  Gundlach  says  that  the  gutta-percha  ring  will  not  stand  cedar 
oil.  Dr.  Phin  has  suggested  that  in  time  the  gutta-percha  tissue  will 
disintegrate,  but  the  author  has  not  yet  noticed  this,  and  does  not 
think  it  will  happen  under  the  cover  of  a  "  mount,"  especially  if  pro- 
tected by  a  ring  of  cement  subsequently  applied.  If  it  does,  it  will 
of  course  be  a  great  objection  to  its  use.  The  "  tissue  "  becomes  so 
charged  with  electricity  by  handling,  and  also  by  punching,  that  it 
interferes  seriously  with  the  latter  operation,  and  thus  makes  it  neces- 
sary to  place  strips  of  the  "  tissue  "  on  thin  moistened  strips  of  paper, 
and  to  punch  out  both  at  the  same  time.  The  preparation  of  the 
shellac  rings  by  the  turntable  obliges  one  to  keep  on  hand  a  large 
stock  all  the  time,  to  ensure  perfect  drying  and  to  have  them  always 
ready.  The  author  is  obliged  to  have  some  1000  or  1500  on  hand  in 
advance,  and  this  necessitates  a  considerable  outlay  in  stock  which 
will  not  always  be  convenient  for  amateurs. 

For  the  above  reasons,  a  new  process  is  now  proposed  which 
appears  to  meet  all  the  desired  wants,  and  which  combines  the 
advantages  of  the  shellac  cement  and  the  gutta-percha  rings.  The 
author  says  that  "  the  very  simplicity  of  this  process  causes  him  to 
wonder  why  it  was  not  thought  of  before." 

Take  a  sheet  of  thin  writing  paper,  white  or  coloured,  and  dip  it 
into  thick  shellac  varnish  (shellac  dissolved  in  alcohol),  and  hang  it 
up  to  dry.  When  thoroughly  dry,  it  should  have  a  good  glaze  of 
the  varnish  on  it  (different  thicknesses  of  paper  can  be  used  according 
to  depth  of  cell  required).  Out  of  this  shellac  paper  cut  the  rings, 
and  these  can  be  made  in  any  quantity,  and  kept  for  any  time.  The 
process  of  mounting  is  simple.  The  slide  is  cleaned  and  the  flat 
paper  ring  placed  in  the  centre ;  on  this  the  cover  is  placed,  having 

*  '  Science,'  i.  (1880)  p.  74.  t  See  tliis  Journal,  ante,  p.  861. 


INVERTEBRATA,    CRYPTOaAMIA,    MICROSCOPY,    ETC.  1039 

the  object  dried  on  it,  and  the  two  are  held  together  by  the  forceps 
and  gently  warmed ;  this  serves  to  attach  the  ring  to  the  slide  and 
cover  at  several  points,  so  that  the  forceps  may  now  be  laid  aside. 
The  next  step  is  to  take  a  glass  slip  (another  slide),  and  laying  this 
on  the  cover,  to  grasp  the  two  slides  at  each  end  by  the  finger  and 
thumb  of  the  two  hands,  and  pressing  them  tightly  together,  to  warm 
the  slide  gently ;  by  looking  at  the  ring  obliquely  on  the  under  side 
one  can  tell  at  once  when  all  the  air  is  pressed  out,  and  the  adhesion 
is  complete  between  the  cover  and  the  ring,  and  also  the  ring  and  the 
slide,  and  they  must  be  held  together  a  moment  or  two  to  cool.  If 
the  lac  is  sufiiciently  thick  on  the  paper,  the  adhesion  takes  place 
quickly,  and  with  moderate  heat,  and  there  will  be  no  danger  of 
breaking  the  cover,  unless  it  has  been  warped  in  the  process  of  warm- 
ing, which  will  sometimes  occur  when  very  thin  glass  has  been  heated 
too  much  for  the  purpose  of  burning  off  the  organic  matter,  or  when 
the  su2)port  is  too  small  in  diameter,  or  when  it  is  not  flat. 

The  author,  in  conclusion,  says,  "  I  cannot  conceive  of  anything  more 
satisfactory  than  these  rings.  IMany  largo  objects  which  would  be 
crushed  if  one  used  only  the  shellac  rings  made  on  the  slide  by  the 
use  of  the  turntable,  by  the  giving  way  of  these  by  softening,  and 
under  the  necessary  pressure  for  attaching  the  cover,  are  perfectly 
protected  by  the  paper  rings.  I  am  satisfied  that  the  balsam  mounts 
will  be  much  less  frequently  used  as  soon  as  we  can  find  some  sure 
dry  process.  The  diatoms  as  a  rule  show  much  better  when  mounted 
dry,  and  with  whole  frustnles,  exhibiting  both  the  side  and  the  front 
view,  also  the  mode  of  attachment,  &c.  The  dry  mounts  are  certainly 
to  be  preferred  when  they  are  desired  for  anything  except  pretty 
objects,  and  even  for  this  latter  purjjosc  there  is  often  a  very  great 
difference  in  favour  of  the  dry  mount.  Although  I  have  not  used 
these  shellac  paper  rings  for  any  very  great  length  of  time,  yet  I  can 
see  no  reason  why  they  should  not  be  equal  to  the  simple  shellac  ring 
for  durability,  and  very  much  superior  to  it  in  other  respects." 

We  should  note,  in  regard  to  this  suggestion  of  Prof.  Hamilton 
Smitli,  that  the  rings  above  referred  to  were  the  subject  of  a  paper 
read  to  this  Society  by  Mr.  James  Smith*  in  18()5. 

Dr.  Phin  has  found,  he  says,t  "that  pure  shellac  in  all  its  forms 
is  very  apt  to  separate  from  the  glass  after  a  time. 

Wax  Cells. :J: — Dr.  Phin  does  not  appear  to  be  disposed  to  abandon 
these  cells,  as  suggested  by  their  originator  (Prof.  Hamilton  L. 
Smitli).  He  has  carefully  examined  a  number  of  slides  of  the  mounting 
material  of  which  wax  forms  a  part.  Some  were  found  to  be  spoilt, 
others  were  good.     It  is- evident  that  the  dew  may  arise  either  from 

*  'Trans.  Micr.  Soc.  Lond.,'  xiv.  (18GG)  p.  29.  The  following  is  nn  extract 
from  Mr.  Jnnies  Smitli's  proper: — "lUitli  surfiic-c8  of  the  rnrdboanl  [are  to  he] 
coveri'd  willi  a  cciuiiit  turimil  of  whcUac  or  niaiiiic  j^hir  di.sscdvi'd  in  naplitha  ; 
onu  to  Ihrou  cuutinj^s  of  this  ceiiunt  Ix-iii^  u.sually  sullifirnt,  cure  hcinf:  tnkcu 
that  one  ia  perfectly  dry  lioturo  the  next  is  iipplied.  The  cells  hi  iug  tlius  pre- 
pared, tlicy  Clin  be  cnt  oil",  and  by  the  ap|dication  of  heat  and  slight  pressure  are 
easily  attached  to  a  class  slide." 

t  *  Am.  Journ.  Micr.,'  v.  (IS.s(l)  p.  WX  X  Ibid. 

a  z  2 


1040  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

the  object  itself  or  from  the  mountirig  material.  In  the  case  of  such 
objects  as  Polycistina  and  diatoms  which  have  been  exposed  to  low 
red  heat,  it  is  unlikely  that  any  vapours  would  ever  be  given  off,  and 
slides  of  these  objects  have  been  found  both  with  dew  and  free  from 
it.  A  good  deal  probably  depends  upon  the  quality  of  the  wax  and 
the  processes  used  in  bleaching  it.  Where  bleached  by  exposure  to 
sunlight  and  water,  and  afterwards  carefully  melted,  it  is  believed  no 
vapour  will  be  given  off.  Where  the  wax  has  been  bleached  by 
the  action  of  acids  and  chlorine  it  is  difficult  to  tell  what  changes  may 
occur. 

Amongst  the  directions  for  mounting  in  wax  cells,  one  which  has 
been  generally  given  and  very  usually  followed,  is  to  soften  the  wax 
with  turpentine  at  the  point  where  the  object  is  to  be  placed.  When 
this  has  been  done,  and  the  cell  closed  immediately,  the  turpentine  is 
sure  to  evaporate  and  settle  on  the  cover.  It  there  becomes  oxidized 
or  ozonized,  so  that  it  is  no  longer  volatile,  and  it  was  undoubtedly 
this  ozonized  turpentine  which  resisted  the  high  temperature  alluded 
to  by  Prof.  Smith.  Instead  of  turpentine,  a  copper  wire  should  be 
used,  highly  heated,  and  held  near  but  not  in  contact  with  the  wax. 

To  the  same  tenor  are  the  remarks  of  Mr.  C.  F.  Cox  and  Mr.  J.  F. 
Stidham.*  The  former  points  out  that  while  if  the  ground  for  con- 
demnation— "dew"  on  the  cover-glass — were  found  exclusively  in 
the  case  of  wax  cells,  it  might  be  fair  to  infer  that  the  cause  was  the 
wax,  yet  as  it  is  found  more  or  less  in  cells  of  all  kinds,  and  is  not 
worse  in  wax  cells  than  in  most  others,  the  denunciation  by  Prof. 
H.  L.  Smith  of  his  own  invention  is  not  justified.  The  misty  con- 
densation may  possibly  be  caused  in  some  cases  by  emanations  from 
the  sheet  wax,  but  Mr.  Cox's  experience  goes  to  prove  that  it  is 
mainly  due  to  the  too  free  use  of  cements  containing  resinous  or  oily 
solvents,  like  turpentine  or  benzole,  though  sometimes  it  may  arise 
from  the  want  of  dryness  in  the  object  itself,  or  a  recrystallization  of 
chemical  constituents  of  the  cements,  as  the  Professor  suggests.  If 
a  cement  is  used,  composed  of  shellac  dissolved  in  alcohol,  plenty 
of  time  allowed  for  the  completion  of  each  step,  no  more  cement  used 
than  is  necessary,  and  the  sj)ecimen  itself  thoroughly  dry,  the  cell  will 
be  free  from  vapour  and  condensations,  and  he  is  therefore  of  opinion 
that  the  wax  cell  is  "the  best  cell  for  dry  objects  that  has  ever  been 
used." 

Mr.  Stidham's  testimony  is  to  the  same  effect.  He  "  has  found 
no  trouble  since  covering  the  whole  cell  with  a  thin  film  of  shellac, 
and  using  shellac  to  fix  the  cover,  provided  the  day  was  a  dry  one, 
and  the  cover  is  held  for  a  moment  over  the  lamj)  flame."  He  thinks 
Mr.  C.  C.  Merriman's  suggestion  of  leaving  a  small  opening  so  that 
moisture  may  get  out  would  be  of  practical  advantage  if  it  can  be 
done. 

Improvement  in  Making  Wax  Cells.! — For  making  wax  cells, 
when  they  are  wanted  smoother  and  handsomer  than  they  can  be  made 
with   a  punch  alone,    Mr.  J.  D.  White   recommends  the   following 

*  •  Am.  Journ.  Micr.,'  v.  (ISSO)  p.  207. 

t  '  Am.  Mon.  Micr.  Journ..'  i.  (1880)  p.  150-1. 


INVEBTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1041 

process  as  simpler  and  easier  than  that  of  Dr.  Hamlin,  described  on 
page  507. 

With  home-made  punches  of  ordinary  brass  tubing  (cartiidge 
cases  answer  very  well),  cut  out  rings  and  disks  a  little  larger  than 
the  finished  cells  are  to  be,  and  fasten  them  to  the  sides  by  pressure 
and  gentle  warmth,  after  centering  as  accurately  as  possible.  Then, 
with  a  tool  made  by  bending  a  small  chisel  at  a  right  angle  about 
half  an  inch  from  the  edge,  turn  or  scrape  the  cell  on  a  turntable  until 
it  is  of  the  right  size.  If  the  tool  is  sharp,  a  beautifully  polished  sur- 
face will  always  result.  The  chisels  which  accompany  sets  of  brad- 
awls are  just  right ;  but  any  flat  piece  of  steel,  if  not  too  heavy  or 
clumsy,  will  do.  The  cutting  edge  should  be  about  one-fourth  of  an 
inch  wide.  Punches,  and  all  tools  used  for  cutting  wax,  should  always 
be  dipped  or  moistened  in  starch,  prepared  precisely  as  for  laundry 
use ;  this  operates  much  better  than  water,  or  indeed  anything  else. 

Atwood's  Rubber  Cell.* — Mr.  H.  F.  Atwood  calls  attention  to  a 
cell  for  opaque  objects  made  of  hard  rubber  highly  polished. 

Fig.  112  is  a  sectional  view  of  the  cell,  the  dotted  line  indicating 
the  position  of  the  thin  glass  covei*.    The  base  is  solid, 
giving  a  black  background  of  rubber,  and  round  the  top         *^'^'  ^  '"" 
is  a  ledge  fitted  to  receive  a  ^-inch  cover-glass,  which    ^^^^----^^g^ 
may  be  secured  by  a  little  shellac  or  similar  cement. 

The  cell  is  claimed  to  be  specially  advantageous  in  two  ways : — 
1st.  It  solves  the  problem  which  often  perplexes  the  collector  who  is 
crowded  for  cabinet  room.  Many  objects  for  future  reference  may  be 
mounted,  numbered,  and  put  away  without  a  slide,  a  cabinet  drawer 
holding  200,  while  but  40  slides  could  be  accommodated  in  the 
same  space.  2nd.  In  exchanges  the  cells  may  be  sent  through  the 
post  without  glass  slips,  so  that  there  is  a  saving  in  postage  and  no 
risk  of  breakage. 

Mr.  Atwood  suggests  that  the  cell  "  may  be  attached  to  a  glass 
slip  by  any  cement  before  or  after  preparation."  Our  own  experience 
is  that  rubber  is  by  no  means  easy  to  attach  securely,  and  that  some 
other  means  of  examining  the  cells  under  the  Microscope  will  be  neces- 
sary. In  this  view,  Messrs.  Beck  have  devised  a  circular  cell-holder, 
in  ebonite,  holding  12  cells,  which  lies  upon  the  stage,  and  can  be 
rotated  so  as  to  bring  each  cell  successively  under  the  objective. t 

Parkes's  Frog-plate.  -  Instead  of  the  ordinary  method  of  examining 
the  circulation  of  the  blond  in  the  frog's  foot,  which  is  attended  with 
some  degree  of  inconvenience,  at  any  rate,  to  the  animal,  the  following 
plan  is  recommended; — 

Put  the  frog  into  an  empty  wide-mouthed  bottle  (such  as  a  pickle- 
jar),  cover  the  cork  witli  a  piece  of  linen  rag,  on  which  pour  a  little 
sulphuric  ether,  and  then  insert  the  cork  immediately,  and  lay  the 
bottle  on  its  side.     In  a  ft;w  minutes  the  animal  will  be  sufficiently 

•  'Sciencp,'  i.  (1880)  p.  200. 

t  A  ilrscriptinn  of  tlii.-)  hoMcr,  with  n  flRurf,  will  !><•  •^\\-cn  in  tho  next  iniml)or. 


1042 


RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 


Fig.  113. 


etherized  *  without  affecting  the  circulation,  and  may  then  be  placed 
on  the  frog-plate,  shown  in  Fig.  113,  in  an  erect  position,  with  its  feet 

on  the  circular  glass,  a  little 
soft  tape  being  placed — not  too 
tightly — round  the  body  to  keep 
it  erect.  The  web  of  the  foot 
may  now  be  moistened  with  a 
little  cold  water,  and  the  plate 
laid  on  the  stage  for  examina- 
tion. 

If  sufficiently  etherized,  the 
frog  will  remain  perfectly  quiet 
for  half  an  hour,  and  both  feet 
may  be  examined  alternately. 
The  toes  must  of  course  be 
spread  out  so  as  to  stretch  the 
web,  which  should  be  moistened 
occasionally  with  a  camel-hair 
pencil  dipped  in  cold  water. 
The  process  may  be  repeated 
many  times  on  the  same  frog 
if  carefully  managed,  but  after 
each  examination  it  should  be 
piit  into  a  vessel  with  a  little 
cold  water,  till  it  recovers  con- 
sciousness. 

Sternberg's  Culture-cell.f — There  are  many  experiments  in 
which  a  culture-cell  is  required  which  will  preserve  the  blood  in  a 
fluid  condition,  free  from  atmospheric  contamination,  and  yet  sur- 
rounded by  a  sufficient  amount  of  air  to  furnish  the  necessary  oxygen 
to  organisms  that  may  develop  from  any  germs  that  may  be  present 
in  the  blood.  In  addition  to  this  it  is  necessary  that  a  very  thin 
stratum  of  blood  should  be  within  reach  for  examination  by  the 
highest-power  immersion  objectives. 

The  Boldeman  cell  fulfils  the  first  requirement.  A  central  emi- 
nence is  surrounded  by  a  circular  channel,  ground  in  the  glass,  which 
serves  the  purpose  of  an  air-chamber.  The  summit  of  the  central 
eminence  is  slightly  concave,  and  the  drop  of  fluid  to  be  observed  is 
placed  upon  this  and  protected  with  a  thin  glass  cover,  which  is 
attached  to  the  slide  by  a  circle  of  cement,  or  simply  by  a  little  oil. 

The  main  objection  to  this  cell  was  found  by  Mr.  G.  M.  Sternberg, 
Surgeon  U.S.  Army,  to  be  that  the  stratum  of  blood  held  in  the 
shallow  cup  of  the  central  eminence  was  too  thick  for  satisfactory 
examination  with  high  powers;  that  portion  of  the  fluid  next  the 
cover,  which  could  be  brought  into  focus,  being  shut  off  from  the 

*  It  may  always  be  known  when  the  frog  is  fully  under  the  influence  of  the 
ether,  by  placing  it  on  its  back,  before  taking  it  out  of  the  bottle,  as  it  will  not 
remain  quietly  in  this  position  except  when  etherized. 

t  '  Am.  Mon.  Micr.  Journ.,'  i.  (1880)  pp.  141-3.     1  fig. 


INVERTEBRA.TA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1043 

light  by  floating  corpuscles  in  tlio  background.     And  this  difficulty 
led  him  to  invent  the  following  culture-slide. 

A  circular  hole,  about  \  inch  in  diameter,  is  drilled  through  the 
centre  of  a  glass  slide.  A  very  thin  circle  of  cement,  ^  inch  in 
diameter,  is  then  turned  about  this  central  hole  on  one  side  of  the 
slide,  and  a  thin  glass  cover  is  attached  to  it  by  gentle  pressure. 
When  the  cemeiit  is  thoroughly  dry,  the  cell  is  ready  to  receive 
the  drop  of  blood,  or  other  fluid  which  is  to  be  observed.  This  is 
placed  in  the  bottom  of  the  cell  (a,  Fig.  114),  and  flows  by  capillary 
attraction  into  the  space  below,  between  the  thin  cover  and  the  slide, 
until  it  extends  to  the  circle  of  cement  by  which  the  cover  is  attached. 

Fig.  114. 


a 

he  be 

We  have  thus  a  thin  stratum  of  the  fluid  between  the  points  6  and  c, 
which  may  readily  be  examined  by  inverting  the  slide  and  bringing  an 
immersion  lens  down  upon  any  point  between  the  central  air-chamber 
and  the  circle  of  cement  by  which  the  cover  is  attached.  Finally,  the 
cell  is  closed  by  turning  a  still  larger  circle  of  cement  upon  the  upper 
surface  of  the  slide,  and  attiching  a  larger  thin  glass  circle  (d). 

Mr.  Sternberg  docs  not  sec  why  it  should  not  also  serve  a  good 
purpose  as  a  cell  in  which  to  mount  objects  either  dry  or  in  fluid.  If 
the  manufacturers  would  furnish  glass  slips  of  diflcrent  thicknesses, 
having  central  perforations  of  :j  to  ^  inch  in  diameter,  a  thin  glass 
cover  can  easily  be  attached  to  make  the  bottom  to  the  cell ;  and 
these  might,  for  many  purposes,  replace  the  various  cells  in  common 
use. 

Apertures  exceeding  180°  in  Air. — Mr.  Shadbolt's  note  on  this 
subject  will  be  found  in  the  Proceedings  of  the  November  Meeting, 
infra,  p.  1080. 

Visibility  of  Minute  Objects  — New  Medium  for  Mounting 
{Monohromide  of  Naphthaline). — Professor  Abbe  has  recently  been 
experimenting  upon  substances  adapted  for  mounting  diatoms  (having 
regard  to  the  suggestions  made  in  Mr.  Stoi»henson's  recent  paper  *), 
and  has  discovered  that  monohromide  of  naphthaline  is  very  suitablo 
for  the  purpose,  and  does  not  present  the  inconveniences  of  some  of 
the  other  substances. 

Tlio  liquid  is  colourless  and  oleaginous,  with  the  odour  of  naph- 
thaline. It  is  soluble"  in  alcohol  and  otlicr,  and  has  a  density  of 
1*555,  with  a  refractive  index  of  l-r)5(S,  giving  therefore  as  tho 
"  index  of  visibility"  22  as  against  11  for  Canada  balsam.  It  is  not 
volatile. 

Dr.  II.  van  Ileurck  refers  to  this  substance,  some  of  which  was 
sent  him  by  Mr.  Zeiss.     His  experiments  with  it  have  given  tho  l>est 

•  Sec  this  Joiirnnl,  antr,  p.  ^^CtX, 


1044  RECORD    OF  CURRENT    RESEARCHES   RELATING    TO 

results,  the  diatoms  mounted  in  it  showing  with  "  excessive  beauty." 
The  strife  of  Ampldpleura  pellucida,  amongst  others,  were  clearer  than 
he  ever  before  saw  them.  Objectives,  with  which  he  had  never  been 
able  to  see  the  strife  by  simple  lamp-light,  showed  them  at  once  in 
the  new  medium.  He  considers,  therefore,  that  its  employment  will 
be  found  very  useful  wherever  the  delicate  details  of  diatoms  are  not 
sufficiently  visible  in  ordinary  preparations. 

Dr.  L.  Dippel,  also  writing  *  on  Mr.  Stephenson's  paper,  commends 
oil  of  aniseed  and  oil  of  cassia  for  mounting,  the  last  of  which  has 
especially  proved  to  be  well  adapted  for  making  the  fine  structure  of 
the  siliceous  valves  clearly  visible.  He  has  recommended  both  oils 
for  some  years  to  one  and  another  of  the  German  mounters.  Oil  of 
aniseed  was  employed  by  Professor  Weiss  in  studying  diatoms.f 

Of  the  fluids  which  Mr.  Stephenson  further  proposes,  the  solution 
of  phosphorus  in  bisulphide  of  carbon  is,  Dr.  Dippel  considers,  pre- 
cluded on  account  of  its  combustibility,  and  mounting  in  bisulphide  of 
carbon  as  well  as  in  the  solution  of  sulphur  is  attended  with  so  many 
inconveniences  that  neither  could  well  be  taken  into  common  use  as 
fluids  for  mounting.  On  the  other  hand,  monobromide  of  naphthaline 
is  most  excellently  adapted  for  it.  It  does  not  affect  wax  as  far  as 
experience  has  gone  as  yet,  and  hence  objects  may  be  conveniently  pre- 
pared with  it.  The  cover-glass  should  be  run  round  with  a  ring  of  wax, 
then  with  a  cement  of  isinglass  dissolved  in  spirit  (called  Heller's 
porcelain  cement),  or  Canada  balsam,  rather  thick,  dissolved  in  chloro- 
form ;  finally  closing  with  a  solution  of  shellac.  Amongst  other 
diatoms  thus  mounted,  is  a  small  and  very  finely  striated  Amphipleura 
pellucida,  the  structure  of  which,  with  immersion  objectives — homo- 
geneous-immersion specially — appears  wonderfully  clearly  and  sharply 
defined. 

Absolute  Invisibility  of  Atoms  and  Molecules. J — Professor 
A.  E.  Dolbear  writes : — 

Maxwell  gives  the  diameter  of  an  atom  of  hydrogen  to  be  such 
that  two  millions  of  them  in  a  row  would  measure  a  millimetre ;  but 
under  ordinary  physical  conditions  most  atoms  are  combined  with 
other  atoms  to  form  molecules,  and  such  combinations  are  of  all 
degrees  of  complexity.  Thus,  a  molecule  of  water  contains  three 
atoms,  a  molecule  of  alum  about  one  hundred,  while  a  molecule  of 
albumen  contains  nine  hundred  atoms,  and  there  is  no  reason  to 
suppose  albumen  to  be  the  most  complex  of  all  molecular  compounds. 
When  atoms  are  thus  combined,  it  is  fair  to  assume  that  they  are 

*  «Bot.  Centralbl.,'  i.  (1880)  p.  1148. 

t  Dr.  Dippel,  if  we  understand  him  correctly,  also  points  out  that  "  this 
method  of  preparation  is  not  in  all  respects  new.  He  himself  came  upon  it 
in  his  investigations  on  the  cell-wall  ['Das  Mikroskop,'  i.  pp.  67  and  83],  and 
since  1867  has  mounted  not  only  histological  objects,  but  also  various  diatom 
preparations  in  oil  of  aniseed  and  oil  of  cassia."  We  need  hardly,  however,  men- 
tion that  the  point  of  Mr.  Stephenson's  paper  is  not  to  describe  as  a  noveltr^  the 
use  for  mounting  of  phosphorus,  bisulphide  of  carbon,  &c. ;  for,  as  he  says  in 
the  paper,  preparations  were  so  mounted  in  1873,  when  his  previous  paper  was 
read. 
■  t  'Science,'!.  (1880)  p.  150. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1045 

arranged  in  tho  three  dimensions  of  space,  and  that  the  diameter  of 
the  molecule  will  be  approximately  as  the  cube  root  of  the  number  of 
atoms  it  contains,  so  that  a  molecule  of  alum  will  be  equal  to 

(VIOO  =  4-64)  iruV^DW  =  ?7TTJ7FTT  mm., 
and  a  molecule  containing  a  thousand  atoms  will  have  a  diameter  of 

A  good  Microscope  will  enable  a  skilled  observer  to  identify  an 
object  so  small  as  the  a- .T.nr  vaxn.  Beale,  in  his  works  on  the  Micro- 
scope,  pictures  some  fungi  as  minute  as  that ;  and  Nobert's  test  bands, 
and  the  markings  upon  the  Amphipleiira  pellucida,  which  are  about  tlio 
same  degree  of  fineness,  are  easily  resolved  by  good  lenses.  If  thus 
the  efficiency  of  the  Microscope  could  be  increased  fifty  times 
('"""""  =  50),  it  would  be  sufficient  to  enable  one  to  see  a  molecule 

400  ■"         _         _ 

of  albumen  ;  or  if  its  power  could  be  increased  one  himdred  and 
seven  times,  it  would  enable  one  to  see  a  molecule  of  alum. 

Now,  Helmholtz  has  jiointed  out  the  probability  that  interference 
will  limit  the  visibility  of  small  objects  ;  but  suppose  that  there 
should  be  no  difficulty  from  that  source,  there  are  two  other  conditions 
which  will  absolutely  prevent  us  from  ever  seeing  the  molecule. 

1st.  Their  motions.  A  free  gaseous  molecule  of  hydrogen  at  the 
temperature  of  0°  C,  and  a  pressure  of  760  mm.  mercury,  has  a  free 
path  about  ttiooo  '^™-  ^^  length,  its  velocity  in  this  free  path  being 
1860  m.  per  second,  or  more  than  a  mile,  while  ils  direction  of  move- 
ment is  changed  millions  of  times  per  second.  Inasmuch  as  only  a 
glimpse  of  an  object  moving  no  faster  than  one  millimetre  per  second 
can  be  had,  for  the  movements  are  magnified  as  well  as  the  object  itself,  it 
will  be  at  once  seen  that  a  free  gaseous  molecule  can  never  be  seen,  not 
even  glimpsed.  But  suppose  such  a  molecule  could  be  caught  and 
held  in  the  field  so  it  should  have  no  free  path.  It  still  has  a  vibra- 
tory motion,  which  constitutes  its  temperature.  The  vibratory  move- 
ment is  measured  by  the  number  of  undulations  it  sets  up  in  the  ether 
per  second,  and  will  average  five  thousand  millions  of  millions — a 
motion  which  would  make  the  space  occupied  by  the  molecule  visibly 
transparent,  that  is,  it  could  not  bo  seen.  This  is  true  for  liquids  and 
solids.  Mr.  D.  N.  Hodges  finds  the  path  of  a  molecule  of  water  at  its 
surface  to  be  •  0000024  mm.,  and  though  it  is  much  less  in  a  solid,  it 
must  still  be  much  too  great  for  observation. 

2nd.  They  are  transparent.  Tho  rays  of  the  sun  stream  through 
the  atmosphere,  and  tlio  latter  is  not  perceptibly  heated  by  them,  as  it 
would  bo  if  absori)tion  took  place  in  it.  Tho  air  is  heated  by  conduc- 
tion contact  with  the  earth,  which  has  absorbed  and  transformed  tlio 
energy  of  tho  rays.  -When  selectivo  aUsorption  takes  place,  tho 
number  of  rays  absorbed  is  small,  when  compared  with  tho  whole 
number  presented,  so  that  practically  tlie  separate  molecules  would  bo 
too  transparent  to  bo  seen,  though  their  maguitudo  and  motions  were 
not  absolute  hindrances. 

Wale's  "Working  Microscope." — Tho  now  feature  of  this  instru- 
ment by  Mr.  G.  Walo  (Fig.  115)  consists  in  tho  method  of  suspending 


1046 


RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 


tlie  main  limb  carrying  the  optical  body,  so  that  it  may  be  inclined  at 
any  angle.  It  is  suggested  that  the  ordinary  method  changes  the 
position  of  the  centre  of  gravity  of  the  instrument  so  considerably 
as  to  render  it  more  or  less  unsteady,  while  the  new  method  avoids 
the  difficulty,  and  at  the  same  time  furnishes  a  secure  and  convenient 
means  of  clamping  the  body  at  any  position. 


Fig.  115. 


The  stage  and  optical  body  are  supported  on  the  curved  limb, 
which  is  nearly  a  semicircle,  as  shown  in  the  figure.  This  limb  has 
sectoral  grooves  about  90°  in  arc  on  either  side,  and  slides  between  cor- 
responding curved  jaws,  on  the  inner  side  of  the  upright  pieces  of  the 
foot.   The  foot  itself  is  made  in  two  symmetrical  pieces  fitting  together, 


mVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1047 


Fig.  116. 


and  grasping  the  limb  by  means  of  a  screw,  of  wliicli  the  milled  head 
is  seen  at  the  right-hand  side  of  the  instrument.  By  loosening  this 
screw  somewhat  the  curved  limb  is  released ;  the  sectoral  grooves 
then  permit  it  to  slide  between  the  jaws  of  the  foot  until  the  tube 
reaches  the  desired  position  (vertical,  horizontal,  or  an  intermediate 
position),  when  it  may  be  clamped  by  tightening  the  screw. 

The  fine  adjustment  moves  the  entire  body  by  a  lever  in  contact 
with  the  screw  (milled  head)  shown  on  the  back  of  the  limb,  the 
distance  between  the  eye-piece  and  the  objective  not  therefore 
changing. 

The  rotating  stage-clips  can  be  applied  to  hold  the  object  on 
either  side  of  the  stage,  as  described  and  figured  in  vol.  ii.  (1879), 
p.  623,  where  this  Microscope  was  briefly  alluded  to.* 

Seibert  and  Krafft's  Fine  Adjustment. — We  referred  on  p.  883 
to  this  fine  adjustment  (Figs.  99  to  101),  citing  an  explanatory 
passage  from  Niigeli  and  Schwcndener's  '  Das  Mikroskop.'  The 
accompanying  figure  (Fig.  IIG )  from  the  same  authors  will  enable  the 
reader  to  understand  the  mechanism,  and  the 
description  will  correct  a  slight  inaccuracy 
(in  the  original)  relative  to  the  non-displace- 
ment of  the  optic  axis. 

The  focussing  -  screw  8  acts  upon  the 
funnel-shaped  head  of  the  pivot  m,  the  upper 
end  of  which  acts  in  a  similar  manner  upon 
//,  the  solid  bar  attached  to  the  optical  body. 
The  ring  r,  which  serves  as  a  guide-piece, 
lies  loose  in  the  hollow  column,  and  as  a 
rule  does  not  touch  the  pivot ;  its  function  is 
merely  to  prevent  the  point  of  the  pivot  from 
slipping  out  of  the  notch  in  //.  The  cross- 
bars h  h  (two  on  each  side)  are  attached  by 
screws  to  the  hollow  column,  and  the  optical 
body  is  held  between  the  points  of  four  screws 
near  the  front  ends  of  the  bars.  The  focus- 
sing motion  is  communicated  to  the  solid  bar 
//by  the  screw  s  acting  against  the  pressure 
of  the  spiral  spring  shown  above  by  dotted 
line,  the  friction  being  confined  to  the  eight 
screw-points  of  the  four  cross-bars.  The 
movement  is  similar  to  that  of  an  ordinary 
parallel  ruler  with  connecting  bars,  the 
hollow  column  being  the  stationary  side. 

It  is  obvious  from  .an  inspection  of  the 
figure  that  the  optical  axis  must  suffer  a 
sliglit  displacement.  Any  movement  of  the 
focussing  screw  8  upwards  or  downwards 
from  tlie  normal  position  as  shown,  will 
cause  the  cross-bars  bh  to  assume  a  diagonal  position  ;  the  pivot  m 
will   consequently  incline  from   its  base   backwards,  and   the   solid 

♦  See  also  Dr.  Carpenter's  obscrvntions  on  tliis  Microscope,  infra,  p.  lOSC. 


1048  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

bar  //  will  be  drawn  in  the  same  direction,  and  with  it,  of  course, 
the  optic  axis. 

This  method  of  fine  adjustment  presents  difiiculties  in  combination 
with  a  rotatory  stage,  and  for  comparative  micrometrical  measurements. 
The  position  of  the  milled-head  at  the  lower  end  of  the  column  is, 
however,  very  convenient,  as  the  hand  rests  on  the  table  while 
focussing. 

"Sliding"  Objectives.  —  The  Microscope  shown  in  Fig.  117 
(Parkes's  "  English  Medical  Microscope  ")  is  provided  with  a  '•  patent 

Fig.  117. 


sliding  adapter,"  for  enabling  the  powers  to  be  applied  and  changed 
.very  rapidly,  without  the  loss  of  time  occasioned  by  screwing.     It  is 


niVERTEBRATA,    CRYPTOGAMIA,  MICROSCOPY,    ETC. 


1049 


Fig.  118. 


claimed  that  this  plan  will  be  found  to  save  much  time   in  cursory 
examinations,  such  as  medical  men  have  frequently  to  make. 

In  Fig,  118  A  is  the  adapter,  shown  natural  size  (having  the  Society 
screw,  it  fits  any  Microscope);  this  adapter  contains  a  "sprung" 
tube  into  which  the  tube  B  slides,  carrying  the  optical  part  C  (a 
2-inch  in  the  figure)  at  its  lower  end.  All  the  objectives  are  composed 
of  the  sliding-tube  B  and  the  optical  part  C,  which  together  form  one 
piece  about  the  usual  size  of  an  objective.  In  use,  the  adapter  A  is 
kept  screwed  to  the  body  of  the  instrument,  and 
the  removal  of  B  C  from  A  is  effected  by  simple 
withdrawal,  as  in  the  case  of  an  eye-piece,  and 
another  power  can  thus  be  readily  substituted. 

For  the  convenience  of  those  who  have  ob- 
jectives with  the  Society  screw,  the  lower  end  of 
the  compound  body  of  the  Microscope  is  screwed 
to  the  standard  size,  so  that  by  simply  unscrewing 
the  adapter  which  receives  the  objectives  belong- 
ing to  the  instrument,  any  standard  glass  may 
be  used.  On  the  other  hand,  by  sliding  any 
of  the  former  objectives  into  the  adapter  when 
thus  unscrewed,  they  may  be  used  on  any  other 
standard  instrument.  The  Society  screw  has  not 
been  adopted  for  the  optical  part  (joining  C  to  B), 
which,  however,  it  would  be  advantageous  to  adopt 
if  it  can  be  done  mthout  increasing  the  weight 
to  such  an  extent  that  the  latter  would  slip  down 
out  of  the  adapter.  With  the  Society  gauge, 
any  objectives  might  of  course  be  ajiplied.  At 
present,  the  use  of  the  sliding  arrangement  is 
confined  to  the  maker's  own  objectives. 

Instead  of  the  "  sprung "  tube,  the  plan 
adopted  by  Mr.  Browning  for  astronomical  eye- 
pieces might,  we  think,  be  made  use  of  with 
advantage,  viz.  to  make  the  sliding  tube  B  not 
cylindrical,  but  tapering,  the  "  taper  "  being  for  a  short  distance 
below  the  middle  less  rapid  tliau  at  the  middle  part,  the  portion  next 
the  collar  being  exactly  cylindrical. 

Homogeneous  -  immersion  Objectives  for  the  Binocular,  — 
Fig.  ll'J  shows  in  natural  size  a  ,'.,  hoiiio^ciicdus-immcrsiou  objective 
of  Bowel]  and  Loahuid  made  as  described  by  Mr.  II.  Gibbes  at  p.  373, 
for  use  with  the  ordinary  Weuham  binocular,  and  showing  both  fields 
fully  illuminated. 

The  lenses  of  the  objective  are  contained  within  the  lower  part  of  B, 
tlie  u[»i)er  portion  of  B  being  a  very  short  adapter  into  which  the 
former  can  be  screwed  from  behind.  The  back  lens  is  thus  brought 
to  within  about  a  (juarter  of  an  inch  of  the  binocular  prism.  As  the 
objective  is  so  mutli  shortened  it  is  necessary  with  most  Microscopes 
to  have  eitlier  a  super-stage  or  a  special  arrangenu'iit  for  allowing  tlio 
tube  to  be  racked  down  that  tiio  objective  may  focus  upon  the  object 
on  the  ordinary  stage. 


1050 


RECORD    OF   CURRENT    RESEARCHES   RELATING    TO 


When  not  required  for  use  with  the  Binocular  prism  the  lenses 
are  screwed  to  the  long  adapter  A. 

Mr.  Wenham  many  years  ago  suggested  the  use  cf  a  very  small 
binocular  prism  with  high-power  objectives.  The  prism  was  mounted 
in  a  special  tube  and  was  slipped  down  the  body  of  the  objective 
almost  to  touch  the  back  lens.  Fig.  120  shows  (natural  size)  an  -|- 
objective  (with  correction-adjustment)  constructed  by  Messrs.  Powell 
and  Lealand  on  Mr.  Wenham's  plan,  D  being  the  objective  complete, 
and  C  the  tube  with  the  binocular  prism.  The  objective,  as  will  be 
seen,  is  shorter  than  usual. 

Fig.  120. 


Fig.  119. 


The  plan  first  described  can  be  used  more  effectively  with  homo- 
geneous-immersion objectives,  as  they  do  not  necessarily  require 
correction-adjustment.  The  body  can  therefore  be  much  shorter  and 
the  back  lens  almost  in  contact  with  the  binocular  prism. 

Extra  Front  Lenses  to  Homogeneous-immersion  Objectives. — 
It  is  suggested  *  that  if  such  an  objective  as  Powell  and  Lealand's 
new  formula  homogeneous-immersion  -jVt  (aperture  =  142°  in  crown 
glass  of  index  1  •  5  nearly,  by  means  of  a  front  lens  greater  than  a 
hemisphere),  were  provided  with  two  extra  front  lenses,  one  giving 
an  aperture  in  glass  of,  say,  115°  and  one  giving  90^,  we  should  be 
enabled  to  view  objects  through  a  considerable  range  of  thickness  of 
covering-glass,  approaching  in  each  case  to  the  maximum  aperture 
that  could  be  used,  and  hence,  probably,  we  should  find  much  less 
need  of  \  or  jL  objectives. 

By  the  homogeneous-immersion  formula  adopted  by  Powell  and 
Lealand  the  focal  distance  is  practically  a   constant    quantity  ;    it 

*  '  Eng.  Mech.,'  xxxii.  (1880)  p.  84.        t  See  this  Joiirnol,  ante,  p.  8S6. 


INVERTEBRATA,    CRYPT0GA3IIA,    MICROSCOPY,   ETC.  1051 

follows  then  that  a  reduction  of  the  aperture  by  making  the  front 
lens  thinner  immediately  provides  greater  working  distance  without 
affecting  the  aberrations,  for  as  the  first  refraction  takes  place  at  the 
posterior  (curved)  surface  of  the  front  lens  the  removal  of  any  portion 
of  thickness  at  the  auterior  (plane)  surface  simply  cuts  off  zones  of 
peripheral  rays  without  altering  the  distance — the  distance  being  at 
once  filled  up  by  the  homogeneous-immersion  fluid  or  by  an  extra 
thickness  of  covering-glass.  An  extra  front  lens  may  then  be  applied 
to  the  back  combinations  of  such  a  ^^^  to  enable  the  observer  to  view 
an  object  through  a  covering-glass  that  would  be  practically  a  maxi- 
mum thickness  for  an  ■}  (aperture  =  90^)  constructed  on  the  usual 
formula  where  the  setting  encroaches  on  the  active  spherical  refrac- 
ting surface  ;  a  second  front  might  give  a  high  average  aperture  for 
a  -Y^  (115'^),  whilst  the  thickest  front  (representing  the  maximum 
aperture  of  the  whole  construction,  142')  enables  the  observer  to  view 
an  object  with  a  greater  aperture  than  has  hitherto  been  obtained  with 
any  j\-.,  owing  to  the  difficulties  of  construction,  and  through  a  thicker 
covering -glass  than  a  y'.y  of  this  aperture  (even  if  it  could  bo  success- 
fully made)  would  permit  of ;  hence  the  three  different  fronts  would 
give  a  great  range  of  aperture  with  a  corresjionding  range  of  working 
distance,  which  is  practically  what  is  sought  by  having  objectives 
constructed  of  the  three  different  foci,  i,  yV,  and  y\r. 

We  imderstand  from  Messrs.  Powell  and  Lcaland  that  for  an 
aperture  of  115°  in  glass,  there  would  be  no  necessity  to  mount 
the  front  lens  on  a  plate,  that  aperture  having  already  been  success- 
fully obtained  and  exceeded  by  mounting  the  front  in  the  usual 
way.  The  purpose  of  the  plate  (which  is  only  '003  in.  thick)  is,  as 
before  mentioned,*  to  allow  of  a  portion  of  the  posterior  curved 
refracting  surface  of  tho  front  lens  beyond  the  hemisphere  to  be 
utilized. 

Fluid  for  Homogeneous-immersion  Objectives.— Mr.  A.  A.  Brag- 
don  writes  to  us  in  regard  to  his  note  inserted  at  page  701.  After 
referring  to  tlic  fact  that  sulpho-carbolate  (jf  zinc  was  first  suggested  by 
Professor  Abbe,t  he  says  that  cedarwood  oil,  in  his  opinion,  can  never 
become  generally  useful.  It  varies  so  much  in  diftcront  samples  that 
even  an  index  of  1*512  as  first  named  for  it  cannot  be  relied  upon.  Then 
it  is  so  fluid  that  it  runs  all  over  slide  and  stand,  so  that  the  objective 
cannot  be  immersed  without  placing  the  Microscope  erect  every  time. 
Experimenting  with  it,  however,  in  combination  with  other  oils, 
Bonie  good  results  were  obtained,  e.  g.  with  oil  of  anise,  although  not 
equal  to  the  zinc  and  glycerine,  which  can  be  as  easily  cleaned  from 
the  slide  and  kns  as  glycerine  by  using  water. 

By  taking  equal  -parts  by  weight  of  C.  P.  glycerine  (Price's)  and 
Bulpho-carbolate  of  zinc  crystals,  mingling  the  two,  and  applying 
heat  sufficient  to  lujil  the  glycerine,  a  solution  of  proper  index  wvn  bo 
obtained  for  use  with  a  Zeiss  objictive  of  1*50  index,  or  a  Tolles  of 
1  -525  index  (i.  e.  for  all  practical  purjxises).  If,  however,  one  desires 
to  be  exact  for  the  latter,  the  solution  will   have    to  be  evapoi*ated 

•  See  this  Jourmil,  mdr,  pp.  884  5.  t  "'i'l-  ii-  (l'^T:»)  j.i..  'MC,  and  82:^. 


1052 


RECORD    OF    CURRENT    RESEARCHES    RELATING    TO 


somewhat,  or  more  carbolate  added.  The  solution  can  be  made  in 
about  one  hour. 

No  fear  need  be  had  about  boiling  too  long,  as  the  longer  this  is 
done  the  less  liability  will  there  be  for  the  solution  to  deposit  crystals 
on  the  bottom  of  the  bottle  when  cooled,  which  it  will  do  if  the  tem- 
perature is  only  kept  up  long  enough  to  first  dissolve  the  crystals. 
Some  made  in  October  1879  is  still  free  from  any  deposit.  Filter  while 
hot,  and  the  microscopist  will  have  a  solution  practically  of  fluid 
croivn  glass  as  clear  and  transparent  as  glycerine  itself,  having  only 
one  objection,  viz.  when  of  1  •  50  to  1  •  525  index,  the  consistency  is 
such  that  if  used  on  a  histological  preparation  just  mounted  and  the 
objective  racked  back  to  remove  the  slide,  the  cover,  unless  great  care 
is  used,  will  be  lifted  enough  to  endanger  a  choice  preparation. 

Mr.  Bragdon  is  still  experimenting  with  the  view  of  finding  a 
medium  a  trifle  more  fluid  so  as  to  make  the  homogeneous-immersion 
objectives  "  as  nearly  perfect  as  possible  for  every -day  use." 

Iris  Diaphragms. — To  the  "  Working  Microscope  "  of  G.  Wale  * 
an  inexpensive  and  very  simple  and  ingenious  form  of  "  iris "  is 
adapted,  shown  (separated)  in  Fig.  121.  It  consists  of  a  piece  of 
very  thin  cylindrical  tube  A,  about  £  inch  in  length  and  |  in.  diameter, 

the  whole  circumference  of  which  is  cut 
through  with  shears  to  nearly  its  whole 
length  at  intervals  of  about  ^  inch  ;  by 
means  of  a  screw-collar  B,  attached 
below,  this  cut  tube  is  forced  into  a 
parabolic  metal  shell  (contained  within 
C)  whose  apex  is  truncated  to  an  aper- 
ture of  about  I  inch  ;  the  pressure  of 
the  screw  causes  the  thin  metal  tongues 
to  turn  and  to  overlap  in  a  spiral  which 
gradually  diminishes  the  aperture  to  the 
size  of  a  pin-hole.  On  unscrewing  the 
collar  B,  the  spiral  overlapping  of  the 
tongues  is  released  somewhat,  and  their 
elasticity  causes  the  aperture  gradually 
to  expand. 

As  adapted  to  the  stage  of  the 
"  Working  Microscope,"  the  iris,  when 
unsci-ewed  until  its  aperture  is  smallest, 
is  then  almost  in  contact  with  the  base 
of  the  slide  ;  when  at  its  largest  expan- 
sion it  is  about  y'^  inch  lower.  The  whole  device  is  fitted  into  the 
opening  of  the  stage  from  beneath  (so  as  to  be  flush  with  the  upper 
surface)  with  one  turn  of  a  very  coarse  screw  on  the  edge  of  C — a 
far  more  convenient  plan  than  the  "  bayonet  joint." 

Another  form  of  "  iris "  (Fig.  122)  has  been  manufactured  in 
America  by  Messrs.  Sidle  and  Poalk  (fitting  to  their  "  Acme " 
stand).!     I^  is  similar  in  construction  to  the  earlier  forms  Imown 


See  ante,  p.  1045. 


t  See  this  Journal,  ante,  p.  522. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1053 


in  England,  but  instead  of  the  movement  of  the  plates  being 
controlled  by  a  lever  arm,  there  is  an  outer  cylinder-cap  A,  that 
can  be  turned  like  the  adjusting  collar  of  an  objective.  The  range 
of  aperture  is  from  about   ^  inch  to  a   pin-hole,   and   it   remains 


Fig.  122. 


in  the  same  piano  during  the  motion.  This  diaphragm  is  mounted 
on  a  substage  B  provided  with  centering  motions  (a  short  bar 
working  with  a  loosely  fitting  slot,  that  can  be  clamped  beneath), 
which  is  a  somewhat  primitive  contrivance.  Centering  motions  must 
be  capable  of  exact  adjustment  or  they  are  practically  useless. 

Swift's  Calotte  Diaphragms. — Messrs.  Swift  have  recently  devised 
two  forms  of  "  calotte"  diaphragms  for  use  above  the  achromatic  con- 
denser, and  on  a  level  with  the  plane  of  the  object  stage. 

Fig.  123. 


Fig.  123  shows  the  first  mctliod.     A  small  rectangular  segment  of 
II  sph(!ricul  shell  has  thrdc   ditTcniit  sized  diaphragms  cut,  and  the 

VOL.    III.  4    A 


1054 


BECORD    OF    CURRENT   RESEARCHES    RELATING    TO 


mounting  is  so  contrived  that  by  movement  of  the  lever-arm  (shown 
with  shaped  handle  attached),  the  diaphragms  can  be  successively 
moved  over  the  achromatic  condenser,  the  optical  part  of  which  is 
shown  by  dotted  lines.  The  stage  is  suitably  hollowed  out  beneath 
to  facilitate  the  adjustment. 

Fig.  124  shows  an  improved  form,  which  Messrs.  Swift  regard  as 
superseding  that  shown  in  Fig.  123.    The  diaphragms  are  here  cut  in 

Fig.  124. 


a  metal  "  calotte "  mounted  eccentrically,  so  that  by  rotation  the 
apertures  pass  successively  over  the  top  of  the  achromatic  condenser ; 
the  rotation  is  effected  by  the  projecting  edge  of  the  calotte — somewhat 
as  with  the  diaphragms  in  Gillett's  condenser. 

It  should  be  observed  that  Mr.  Zeiss  has  for  some  time  applied 
calotte  diaphragms  to  his  "  Travelling  Microscope  " ;  *  but  they  do  not 

Fig.  125. 


act  quite  in  the  plane  of  the  stage,  nor  are  they  constructed  to  be 
used  in  conjunction  with  the  achromatic  condenser.  It  is  evident, 
however,  that  the  effect  obtained  is  similar  to  Mr.  Bulloch's  applica- 
tion of  the  Gillett  diaphragm  above  the  condenser.f    In  Messrs.  Swift's 


See  tliis  Journal,  ii.  (1879)  p.  9.5.5. 


t  Post,  p.  1078. 


INVERTEBRA.TA,    CRYPT0GA:M[A,    MIOROSCOPY,    ETC.  1055 

arrangement  (as  shown  on  a  larger  scale  in  Fig.  125)  the  calotte 
is  attached  to  the  under  surface  of  the  stage, — in  Mr.  Bulloch's  plan, 
the  diaphragm  plate  forms  part  of  the  condenser  and  can  thus  be 
removed  at  iilcasure. 

Swinging  Substages. — As  there  seems  to  be  a  tendency  to  provide 
Microscopes  which  have  a  substage  with  the  so-called  '"swinging" 
form,  we  now  extend  the  history  of  such  instruments  by  giving 
descriptions  in  the  succeeding  notes  of  some  which  we  have  not  yet 
described. 

Taken  in  chronological  order,  the  instruments  hitherto  made  with 
such  substages  are  as  follows : — 

Grubb 1853-S  ..  See  vol.  ii.  p.  320,  and  below. 

Thury-Nachet    ..  1855  ..  „   post,  p.  1059. 

RoYSTOS-PiGOTT  ..  1862-4  ..  „   ;?os^,  p.  1060. 

ToLLEs 1871  ..  „   post,  p.  1061. 

BuLLOiH        1873  „    j»08^  p.  1067. 

Zentmaver    and  I  is^fi-RO  /  "    vol.  i.  p.  197,  vol.  ii.  p.  320,  and 

Koss-Zentmayer  /      ■■  '  "  \            a/i^t.',  p.  70i.  andjxjs^p.  1067. 

Tolles-Blackham       ..  1877  ..  „    vol.  i.  p.  392,  and  an<e,  p.  520. 

Bui-Locu        1877  ..  „   post,p.lOTd. 

Sidle  and  Poalk       ..  18S0  ..  „    a?i^^,  p.  522. 

Beck      1880  ..  „    a«i!e,  p.  329. 

Swift 1880  ..  „    ante,p.867. 

Grubb's  Sector  Microscope. — This  is  admittedly  the  earliest  in- 
strument of  the  kind  referred  to  in  the  preceding  note.  Tbe  following 
description  is  contained  in  a  paper  read  on  the  26th  March,  1858, 
to  tbe  Royal  Dublin  Society,*  and  is  entitled  "  On  a  New  Table 
Microscope,  by  Thomas  Grubb,  Engineer  to  the  Bank  of  Ireland  "  : — 

"The  instrument  to  which  I  have  the  honour  of  drawing  your 
attention  this  evening  will  bo  recognized  by  some  present  as  having 
the  same  general  and  peculiar  form  of  that  which  I  had  devised  and ' 
constructed  some  years  since,  and  previous  to  our  (Dublin)  Microscopic 
Society  having  merged  into  the  *  Natural  History '  Society. 

"  The  instrument,  in  its  original  state,  included,  iudeed,  the  advan- 
tages of  extreme  steadiness,  an  improved  fine  adjustment  for  focussing, 
and  improved  safety-tube  for  the  object-glass,  with  the  means  of 
viewing  ob.ects  (placed  on  a  horizontal  stage)  at  the  most  comfortable 
angle  for  vision.  But  it  is  the  peculiarity  of  the  instrument,  in  its 
present  state,  that  it  removes  all  necessity  for  that  subsidiary  and 
costly  apparatus  for  illumination  which  those  microscopists  who 
pursue  delicate  microscopic  research  find  it  necessary  to  provide,  in 
addition  to  the  Microscope  pr()j)er  ;  and  not  only  this,  but  tbe  present 
instrntnent  enables  the  observer  to  apply,  with  a  facility  otherwise 
unattainable,  without  removing  the  eye  from  the  instrument,  without 
any  changing  of  parts,  and  by  simply  moving  its  one  illuminator  on 
its  sector,  every  kind   of  illumination,  ^crl  Uim,  to  an   object  placed 

•  'Jniim.    R.   Diihliii  Sot.,'  18r)S;  roproiliu-cd   in  '  Knp:l.  Meoli.,' xxii.  (1880) 
p.  229. 

4    A    J 


1056 


EECORD   OF    CUKRENT   RESEARCHES   RELATING    TO 


A  A.  The  base  (of  mahogany). 

B.  One  of  the  two  brackets  of  support. 

C.  One  of  the  two  milled  heads  for  clamping 
the  instrument  at  the  desired  inclination  for  use. 

D.  One  of  the  milled  heads  for  coarse  adjust- 
ment of  focns,  acting  upon  a  strong  triangular - 
bar  (not  seen  in  tlie  engraving). 

E.  illuminating  prism. 

F.  Milled  ring  for  adjusting  by  hand  the 
azimuth  of  the  prism. 

G.  Slide,  with  rack  and  pinion,  for  adjusting 
the  distance  of  the  prism  from  the  object. 

H.  Sector  (seen  also  at  h)  on  which  the  prism 
Is  moved  by  hand  through  any  required  arc  con- 
centric with  the  object  on  the  stage. 

I.  The  stage ;  i  i,  upper  and  lower  milled 
rings,  which  produce,  on  being  turned  by  hand, 
the  slow  motions,  in  two  directions,  of  the  object - 
plate  of  the  stage. 


K.  iiracket-piece  supporting  the  stage,  and 
also  the  plate  for  carrying  the  polarizer  when 
required. 

L.  Toothed  wheel  with  pinion  and  milled 
nut  for  revolving  the  stage  In  azimuth. 

M.  Dovetailed  slide  carrying  both  stage  and 
sector,  with  the  illuminating  prism.  A  screw  and 
its  bent  lever  (the  latter  passing  to  the  back  of 
the  instrument)  are  partially  seen  at  N  ;  and  at 
O  is  a  spiral  spring  which  keeps  the  slide  M  in 
close  contact  with  the  screw  N.  The  lever  N  is 
equally  available  to  either  hand  at  the  back  of 
the  instrument ;  P  P  are  opposing  screws  which 
serve  to  bring  the  optic  axis  of  the  body  or  tube 
Q  to  coincide  with  the  centre  of  revolution  of  the 
stage,  Q  being  purposely  not  screwed  (as  usually) 
into  the  projecting  arm,  but  held  (with  a  suffi- 
cient amount  of  lateral  movement)  between  the 
collars  rr. 


raVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1057 

upon  the  stage  of  the  instrument.  It  does  more  than  this  ;  for  it 
enables  the  observer,  when  he  has  produced  any  appearance  or  eflfect  by 
the  illumination  which  he  desires  to  reproduce  at  pleasure,  to  register 
the  same,  so  that  he  can  either  resort  with  certainty  to  it  at  a  future 
time,  or  communicate  the  particulars  to  a  friend,  who,  if  possessed  of 
a  similar  instrument,  can  do  likewise. 

"The  subsidiary  apparatus  for  illumination  of  a  well-furnished 
Microscope  usually  includes  a  set  of  achromatic  condensers,  the  prism 
of  Amici,  the  parabola  of  Shadbolt,  and  Bergin's  addition  to  the 
latter  for  oblique  illumination.  It  is  unnecessary  to  go  into  any  detail 
of  the  trouble  experienced,  and  the  time  frequently  consumed  in  obtain- 
ing, with  the  assistance  of  one  or  more  of  these  appliances,  a  satis- 
factory illumination.  These  di-awbacks  are  well  known  to  micro- 
scopists.  For  the  information  of  others,  I  may  state  that  frequently 
five  minutes  of  very  eye-teasing  work,  and  sometimes  three  times  that, 
are  devoted  to  obtaining  a  satisfactory  result,  which,  after  all,  is  liable 
to  be  undone  by  an  incautious  touch  of  the  mounting,  and  which  is 
only  to  be  restored  by  the  same  tentative  process  of  the  previous 
adjustment. 

"  It  was  such  experiences  as  these  which  led  to  the  improvements 
combined  in  the  present  instrument.  A  little  consideration  was 
sufficient  to  show  that,  assuming  we  are  in  possession  of  an  illumina- 
ting pencil  of  unexceptional  quality  for  every  kind  of  illumination 
required,  then  every  kind  of  such,  including  the  illumination  of 
opaque  objects,  will  be  comprehended  under  two  heads,  viz.  first,  the 
means  of  applying  such  illuminating  pencil  at  all  angles  with 
respect  to  the  jilaue  of  the  object  (or  the  stage  of  the  Microscope)  ; 
secondly,  the  means  of  applying  the  pencil  at  all  azimuths  of 
same. 

"  This  generalization,  so  to  speak,  of  the  illumination  indicated 
the  means  of  carrying  it  out  effectually.  I  had  previously  ascertained, 
from  direct  use,  that  an  achromatized  prism  was  capable  of  giving 
every  kind  of  illumination  required,  in  a  manner  not  surpassed  by 
other  means  extant.  Itc^jecting  the  difficult  matter  of  causing  the  illu- 
minating pencil  to  move  in  azimuth  round  the  object,  I  devised  the 
present  stage,  which,  while  it  is  made  to  revolve,  has  those  objections 
to  revolving  which  appertain  to  other  stages  removed ;  and,  by  making 
a  little  variation  in  the  manner  of  attaching  the  body  (or  tube)  of  the 
instrument  to  its  arm,  means  are  provided  for  readily  bringing  the  optic 
axis  of  this  tube  to  pass  through  the  centre  of  revolution  of  the  stage, 
and  thus  all  objection  to  revolving  the  object,  instead  of  the  light,  is 
got  rid  of. 

"  For  the  other  movement  of  the  prism  (or  that  vertical  to  the 
plane  of  the  stage),  I  have,  as  maybe  seen,  adopted  a  sector,  on  which 
slides  the  carriage  containing  the  prism  and  including  the  ordinary 
adjustment  for  focussing  and  a  small  azimuthal  movement  for  modi- 
fying the  illumination.  This  sector  is  attached  to  the  same  piece 
which  carries  the  stage,  and  so  that  its  centre,  if  i)ro(lueod,  would  cut 
the  optic  axis  of  the  tube  where  an  object  mounte<l  upon  a  glass  slide 
of  the  ordinary  thickness  and  laid  upon  the  stage  of  the  instrument 


1058       Record  op  current  researches  relating  to 

would  be.  A  prism  or  other  object  being  simply  moved  round  on  a 
sector  so  placed,  will  evidently  remain  unchanged  in  its  distance  fz-om 
that  central  point. 

"  In  constructing  the  illuminating  prism,  it  was  to  be  recollected 
that  there  was  but  one  direction  in  which  the  light  could  be  placed, 
viz.  in  the  plane  of  the  object,  or  say  one-tenth  of  an  inch  above  the 
plane  of  the  stage,  and  vertically  to  the  sector's  plane  ;  and,  secondly, 
that  the  distance  of  the  light  from  the  stage  must  be  assumed.  The 
prism,  therefore,  necessarily  reflects  the  rays  at  a  greater  angle  than 
90°,  and  its  reflecting  surface  usually  requires  silvering.  This  has 
been  assumed  to  be  an  objection  ;  but  the  light  is  still  more  than 
ample,  as  well  as  beyond  that  given  by  most  other  illuminators,  the 
prism  having  (although  a  triple  combination)  only  two  uncemented 
surfaces.  I  have,  from  my  own  experience,  adopted  a  distance  for  the 
source  of  light  of  about  15  inches,  as  most  useful  for  general  work  ; 
but  should  a  distance  of  2  feet  or  upwards  be  selected,  then  the  prism 
may  be  one  of  total  reflection  and  its  reflecting  surface  consequently 
remain  unsilvered. 

"  The  manner  of  using  the  instrument  is,  shortly,  as  follows : — 
The  microscopist  will,  of  course,  place  it  as  he  would  any  other 
Microscope,  conveniently  on  a  table,  and  incline  it  to  the  desired  angle 
for  work.  The  lamp,  or  other  source  of  light,  is  to  be  placed  directly 
opposite,  and  in  front  of,  the  instrument,  and  at  the  proper  distance  of 
height,  the  distance  being  always  the  same,  and  the  height  that  which 
brings  the  light  into  the  plane  of  the  upper  plate  of  the  stage.  The 
adjustment  may  be  verified  and  corrected  as  follows : — Place  a  slider 
with  a  grayed  surface  on  the  stage  (grayed  surface  upwards)  ;  move 
the  prism  to  the  lowest  point  of  the  sector  (or  to  zero),  and  turn  it 
directly  outwards,  or  towards  the  light ;  adjust  the  distance  of  the 
prism  from  the  grayed  surface,  so  that  an  image  of  the  light  is  formed 
upon  the  latter ;  and  looking  through  the  tube  of  the  instrument  (the 
lenses  being  removed),  observe  if  the  image  formed  on  the  grayed 
glass  be  central  with  the  tube ;  if  not,  make  it  so  by  a  slight  altera- 
tion in  the  inclination  or  azimuth  of  the  instrument,  without  varying 
its  distance  from  the  light.  It  is  by  no  means  necessary  to  make  these 
adjustments  accurately ;  but  the  more  accurate  they  are,  the  more 
perfectly  will  the  image  on  the  grayed  surface  only  revolve,  and  without 
changing  place,  on  moving  the  prism  on  the  sector.  It  is,  perhaps, 
unnecessary  to  observe  that  the  Microscope,  without  making  any  of 
these  adjustments,  may  be  used  in  the  same  manner  as,  and  with  all 
the  convenience  of,  an  ordinary  instrument,  while,  by  making  the 
adjustments  as  described,  we  obtain  the  peculiar  advantages  sought  for 
in  the  construction. 

"  These  advantages  may  be  shortly  summed  up  as  follows : — An . 
object  being  placed  upon  the  stage,  and  the  focus  adjusted,  the  observer 
can  examine  it  under  every  azimuth  of  illumination  by  revolving  the 
stage,  and  under  every  possible  kind  of  illumination  in  each  azimuth, 
viz.  direct  transmitted  light,  oblique  transmitted,  dark-ground  illu- 
mination, and,  finally,  the  illumination  for  opaque  objects,  by  simply 
moving  the  prism  on  the  sector ;  and  he  can  do  all  this  without  once 


INVERTEBRATA,    CRYPTOaAMIA,    MICROSCOPY,    ETC.  1059 

removing  his  eye  from  the  eye-piece  ;  while  the  quality  of  the  illumi- 
nation, in  all  its  varieties,  is  such  as  is  not  surpassed  by  other  more 
or  less  special  contrivances.  Indeed,  the  general  impression  of  those 
who  have  used  the  instrument  is  that  its  illumination  is  more  eflfective, 
particularly  in  showing  the  delicate  details  of  difficult  objects,  than  any 
other  extant. 

"  Lastly,  and  not  least,  the  power  of  reading  off  on  the  sector  the 
angle  of  illumination  used,  whereby  the  effects  of  different  angles  of 
illumination  can  be  registered,  resorted  to  again  at  pleasure  with 
certainty,  or  communicated  to  other  observers,  enabling  them  to  do  the 
same,  if  provided  with  a  similar  instrument. 

"  Perhaps  I  may  be  permitted  to  conclude  this  imperfect  description 
by  mentioning  what  one  who  is  well  qualified  to  judge  of  the  merits  of 
the  instrument  has  commuuic:ited  respecting  it.  He  quaintly  says, 
'  I  find  but  one  fault  with  your  Microscope,  and  that  is,  that  it  puts 
me  out  of  conceit  with  the  using  of  any  other.'  " 

Although  the  above  paper  is  dated  1858,  it  should  be  noted*  that 
the  main  features  of  novelty  had  been  previously  described  by  Mr. 
Grubb,  viz.  in  1853,  in  the  '  Proceedings '  of  the  Royal  Irish  Academy,f 
and  in  his  j)atent  of  1854,  J  in  both  of  which  the  graduated  sectoral 
arc  is  referred  to.  In  the  paper  of  1853  Mr.  Grubb  said  he  had 
mounted  "  a  suitable  illuminator  on  a  vertical  circular  sector  (nearly 
a  complete  circumference),  concentric  with  the  focus  ;  this  part  of  the 
arrangement  enables  me  to  throw  the  beam  on  the  object  at  all  angles 
of  incidence,  whether  from  beneath,  as  in  the  case  of  translucent,  or 
from  above,  in  the  case  of  opaque  objects,  and  as  the  sector  is 
graduated,  I  have  the  power  of  observing  or  restoring  any  position  at 
pleasure." 

Thury-Nachet  Traverse  Substage. — This  appears  to  be  the  next 
in  order  of  date,  having  been  made  by  M.  Nachet,  on  the  suggestion 
of  M.  Thury,  in  April  1855. 

The  substage  is  shown  in  Fig.  127,  separated  from  the  Microscope. 
It  consists  of  two  sector-bars  C  C  equidistant  from  the  object,  mounted 
parallel  and  attached  to  the  main  limb  of  the  stand  by  screws  behind 
the  square  end  G.  These  bars  carry  the  condenser  B  above,  and  the 
mirror  A  below,  on  a  moving  framework  on  which  is  a  graduated 
scale  F  for  observing  the  degree  of  inclination.  By  means  of  a  rack 
and  pinion  (milled  head  D  shown  on  tlie  further  side  of  figure)  the 
framework,  carrying  condenser  and  mirror,  can  bo  moved  concentri- 
cally with  the  object,  producing  oblique  illumination.  The  traversing 
movement  causes  the  toothed  pinion  H  to  turn  in  the  rack  J,  and  an 
endless  screw  at  the  lower  end  of  the  same  pinion  (behind  tlio  milled 
head  E)  works  on  the  toothed  wheel  I  attached  to  the  mirror  ;  this  auto- 
matic motion  keeps  the  reflected  beam  from  the  surface  of  the  mirror 
exactly  in  the  axis  of  the  condenser  whilst  the  latter  is  being  inclined 
obliquely  to  the  object.  The  mirror  itself  can  bo  adjusted  by  tho 
milled   head  E,  tho  pinion   through    I   being    held    ia   position  by 

♦  'Engl.  Mtch..'  xxxi.  (1880).  t  Vol.  v. 

:  See  this  .lourual,  ii.  (1879)  p.  320. 


1060 


RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 


friction.      An  indicator  arm  on  I  marks  the  degree  of  inclination  on 
the  scale  at  F. 

If  we  suppose  the  apparatus,  as  figured,  to  bo  in  adjustment  for 
central    light,    then,   by   turning   the  milled    head    D,   obliquity  of 


incident  light  is  obtained  as  far  as  the  rack  on  the  sector-bar  or  the 
thickness  of  the  stage  will  permit,  the  surface  of  the  mirror  inclining 
regularly  so  that  the  reflected  light  is  directed  constantly  in  the  axis 
of  the  condenser  throughout  the  traversing  movement. 

The  original  apparatus  from  which  Fig.  127  was  drawn  was  at  once 
forwarded  to  us  by  M.  Nachet  upon  our  applying  for  information  on 
the  subject,  and  at  the  same  time  he  wrote  :  "  The  apparatus  was 
specially  designed  to  keep  the  focus  of  the  illumination  upon  the 
object  with  varying  degrees  of  oblique  incidence.  The  movement 
was,  however,  only  from  back  to  front — not  lateral.  In  Grubb's  and 
more  modern  stands,  lateral  movement  of  the  substage  (unless  the 
lamp  be  attached  to  the  moving  arm)  necessitates  a  continual  readjust- 
ment of  the  mirror  or  reflector ;  whereas  in  this  device  the  mirror 
moves  automatically  with  an  exactly  calculated  differential  motion,  and 
the  light  is  constantly  directed  in  the  axis  of  the  condenser,  conse- 
quently in  the  field  of  view,  whatever  may  be  the  inclination.  The 
observer  can  thus  watch  the  minutest  changes-  developed  by  the 
obliquity,  which  appears  to  me  a  considerable  advantage." 

Royston-Pigott's  Oblique  Condenser  Apparatus. — Dr.  Eoyston- 
Pigott  is  the  inventor  of  an  appai'atus  for  giving  oscillating  oblique 
action  to  the  condenser.     It  was  thus  described  *  by  him : — 

"  In  former  times  the  precise  position  of  the  mirror  for  throw- 
ing the  rays  of  reflected  light  at  one  particular  angle  (often  hit 
only  with  much  waste  of  time  and  labour)  was  attained  with 
more  or  less  success  so  as  to  give  the   most  brilliant  definition  of 

*  '  Mon.  Micr.  Jouvn.,'  xvi.  (1876)  p.  178. 


INVEETEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1061 

difficult  objects.  In  1862  I  adapted  a  semicircular  arc  carrying  a 
condenser,  and  afterwards  I  constructed  gimbals  to  carry  an  achro- 
matic condenser  at  any  angle  of  obliquity,  attached  to  a  double- 
motion  stage  placed  exactly  beneath  the  upper  stage  movements :  by 
this  contrivance  particular  angles  of  illumination  could  be  readily 
attained  \vithout  the  excessive  aberration  of  the  usual  wide-angled 
achromatic  condenser.  The  instrument  is  exhibited  in  the  South 
Kensington  Museum  Collection,  No.  3551 — described  as  follows  : — 
'  3551.  Microscope  with  complex  adjustments,  searcher,  and  oblique 
condenser  apparatus.  This  Microscope  is  fitted  with  a  peculiar 
hypocycloidal  movement  and  traversing  screws  for  very  delicate 
observations.  The  condenser  possesses  wide  rectangular  movements 
combined  with  a  unique  oscillatory  oblique  action  for  directing  the 
minute  image  of  a  flame  or  of  the  sun  either  directly  or  obliquely 
upon  any  desired  point  in  the  field  of  view,  giving  fine  views  of 
many  difficult  objects '  " 

ToUes'  "Radial  Arm"  and  "Circular  Track"  Microscopes. — 
Our  information  in  regard  to  these  Microscopes  is  derived  from 
certain  sworn  depositions  which  have  been  forwarded  to  us,  and 
which  we  print  verbatim. 

"  Invention  of  Sicinging  Suhstage. 
Washington  City,  District  of  Columbia,  ss. 

I,  J.  J.  Wood  WARD,  a  Surgeon  in  the  United  States  Army,  and  a 
resident  of  the  city  and  district  aforesaid,  do  hereby  solemnly  swear 
that  Mr.  R.  B.  Tolles,  of  Boston,  visited  me  at  the  Army  Medical 
Museum,  Washington,  District  of  Columbia,  June  30,  1871  ;  that  he 
had  with  him  several  objectives  and  a  small  Microscope-stand  fitted 
with  a  radial  arm  beneath  the  stage,  carrying  a  condensing  lens  of 
about  one  inch  focal  length,  and  so  arranged  that  by  deflecting  the 
arm,  any  degree  of  obliquity  in  the  illumination  could  be  obtained ; 
and  that  I  was  so  pleased  with  the  contrivance  that,  November  8, 
1872,  having  occasion  to  inquire  of  Mr.  Tolles  the  price  at  which 
he  would  make  a  large  stand  for  the  Museum,  I  made  it  a  condi- 
tion in  a  letter  written  on  that  day,  that  the  stand  should  have  a 
'  radial  arm  to  carry  an  inch  condensing  lens  for  oblique  light.' 

J.  J.  Woodward, 

Surgeon  U.S.  Army. 

Sworn  to  and  subscribed  before  mo  this  cightoonth  day  of  Septem- 
ber, A.D.  1880. 

LODIS   SCHADE, 

Notary  Public. 

I,  Edward  W.  Mori.ey,  of  Hudson,  in  the  State  of  Ohio,  Professor 
of  Clutmistry  and  Toxicology  in  Cleveland  CoUogo,  and  Professor  of 
Chemistry  in  Western  Keservo  Collogo,  on  oath  depose  and  say  that 
on  the  Hcveuth  or  eighth  day  of  August,  1872,1  was  in  Boston,  in  the 


1062  RECORD   OF    CURRENT   RESEARCHES   RELATING    TO 

State  of  Massachusetts,  and  there  selected  a  Microscope  objective  at 
the  office  of  Charles  Stodder,  agent  for  Eobert  B.  Tolles,  of  said 
Boston.  Afterward  on  the  same  day  I  met  said  Tolles,  the  maker  of 
said  objective  in  his  manufactory  on  Hanover  Street  in  said  Boston, 
and  conversed  with  him  about  the  manipulation  of  said  objective.  In 
said  conversation  said  Tolles  described  a  device  for  facilitating  the 
application  of  light  of  any  desired  obliquity,  which  device  he  thought 
would  be  possibly  the  best  for  my  purpose.  It  was  to  attach  to  the 
stand  of  the  Microscope  an  arm  vphich  would  rotate  on  an  axis  at  the 
level  of  the  upper  surface  of  the  object-slide.  To  this  arm  an  achro- 
matic condenser  (or  objective  as  a  condenser)  could  be  screwed  so  that 
if  adjusted  to  bring  light  to  a  focus  on  the  object  at  any  one  obliquity 
it  would  still  be  in  focus  at  any  other  obliquity.  Said  Tolles  exhi- 
bited to  me  a  device  used  by  him  on  his  own  stand  to  accomplish  this 
result.  It  consisted  of  an  arm  under  the  stage  carrying  the  achro- 
matic condenser,  which  arm  was  adapted  to  carry  the  condenser 
through  a  considerable  arc,  keeping  it  in  a  radial  position  with  the 
centre  of  motion  at  the  focus  of  the  objective  in  use  in  the  body.  We 
discussed  several  plans  for  securing  the  motion  around  the  plane  of 
the  upper  siu'face  of  the  object.  I  understood  that  the  plan  used  in 
said  Tolles'  stand  was  an  adaptation  of  a  stage  not  originally  designed 
for  the  purpose  and  therefore  of  necessity  the  radial  motion  with 
centre  in  the  plane  of  the  object  was  obtained  by  some  combinations 
whose  nature  does  not  occur  to  me.  My  recollections  about  the  radial 
arm  for  oblique  light  from  a  condenser  as  seen  by  me  at  this  time  are 
very  distinct  because  I  had  then  some  intentions  of  imitating  the 
arrangement  and  actually  afterwards  made  some  preliminary  trials 
in  that  direction.  In  reference  to  my  own  Microscope-stand,  said 
Tolles,  in  said  conversations  suggested  the  making  of  a  semicircular 
track  to  be  borne  on  the  substage  fitting,  which  should  answer  the 
same  purpose  of  carrying  the  condenser  concentrically  with  the 
object  on  the  stage. 

Edward  W.  Moeley. 
State  of  Ohio,  Svmmit  County,  ss. 

Sworn  to  by  the  said  Edward  W.  Morlet,  before  me,  a  Notary 
Public,  within,  and  for  said  County  and  State,  and  by  him  subscribed 
in  my  presence  this  23d  day  of  May,  a.d.  1878. 

Witness  my  hand  and  official  seal  at  Hudson  County  and  State 
aforesaid  this  23d  day  of  May,  1878. 

H.  B.  Foster, 

Notary  Public. 

I,  Orlando  Ames,  of  Somerville,  in  the  Commonwealth  of  Massa- 
chusetts, on  oath  depose  and  say,  that  in  the  years  1870,  '71,  and  '72, 
in  the  shop  of  the  Boston  Optical  Works,  of  which  Mr.  E.  B.  Tolles  was 
Superintendent,  I  had  charge  of  the  work  of  construction  of  Micro- 
scope-stands. That  in  the  years  1870  and  1871  the  first  Microscope- 
stand  of  his  class  A  was  made.  That  after  it  was  otherwise  completed, 
I  by  Mr.  Tolles'  direction  adapted  to  the  stand  a  swinging  arm  to 
carry  a  condenser  at  various  obliquities  to  the  optical  axis  of  the 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1063 

Microscope.*  This  arm  was  hinged  to  have  its  axis  of  rotation  as 
nearly  in  a  line  passing  through  the  object  place  on  the  stage  as  was 
conveniently  practicable.  The  stage  having  mechanical  movements 
was  of  considerable  thickness  and  the  axis  of  the  arm  was  therefore 
fixed  at  a  point  about  three-fourths  of  an  inch  below  the  place  of  the 
object.  The  arm  swung  over  an  arc  of  a  circle  graduated  to  read 
angles  of  obliquity  of  the  arm,  and  the  condenser  had  an  independent 
motion  of  its  own  so  that  its  axis  could  always  be  brought  to  coincide 
with  a  line  passing  through  the  object  on  the  stage.  That  at  this  time 
and  for  an  indefinite  period  before,  I  had  known  of  such  an  arrange- 
ment of  swinging  arm  on  a  Microscope  used  by  Mr.  Tolles  particu- 
larly for  trial  and  testing  of  objectives.  In  this  case  the  whole 
arrangement  could  be  attached  to  the  main  arm  of  the  Microscope 
and  detached  readily.  The  axis  of  motion  of  the  arm  was  under  the 
stage,  but  the  whole  apparatus  had  adjustment  laterally  (or  sidewise) 
so  that  the  swinging  arm  could  bo  brought  into  line  with  any  radius 
of  the  object  as  a  centre  through  a  considerable  range  of  obliquities. 
That  in  the  summer  of  1875,  I,  by  Mr.  Tolles'  direction  constructed 
and  adapted  to  a  Microscope-stand  of  his  class  B,  numbered  [  ] 

and  now  belonging  to  Dr.  J.  Bacon  of  this  city  a  cirrular  track  as  a 
substitute  for  a  radial  arm.  That  this  circular  track  having  its  centre 
coincident  with  the  object  place  on  the  stage  involved  no  change  in  the 
model  or  construction  of  the  B  stand,  whereas  the  incorporation  of  a 
radial  arm  required  considerable  change ;  and  I  desire  to  distinctly 
state  that  the  circular  track  was  adopted  for  that  instrument  instead  of 
the  swinging  radial  arm  to  avoid  such  change  and  reconstruction. 

I  have  also  to  state  that  during  the  period  named,  from  1871  to 
1875,  the  plan  as  an  invention  of  Mr.  Tolles  of  a  swinging  radial 
arm  for  condenser,  and  other  accessories  of  a  Microscope  having  its 
axis  of  motion  in  the  object  or  object-place  on  the  stage  was 
familiarly  known  and  talked  of  in  the  shop  where  his  Microscopes 
were  made.  Orlando  Ames. 

Witness,  F.  L.  Hates. 

Suffolk,  ss.  Boston,  March  19,  1878. 

There  personally  appeared  the  above  named  Orlando  Ames  and 
made  oath  that  the  foregoing  statement,  by  him  subscribed,  is  true. 
Before  me,  Francis  L.  Hates, 

Justice  of  the  Peace." 

In  July  1875,  Mr.  Tolles  made  and  sold  the  instrument  described 
in  the  following  sjtecification  for  a  patent  (the  application  for  which 
was  filed  in  July  1877 1) : — 

•  Note. 

"TOLI.ES"  LAIiOEST  MICROSCOPE. 

*******        Can  bo  furnished  with  radial  arm 
to  carry  accessory  apparatus  at  any  angle  for  $50." 

— C.  St'Kldir's  Price  I-ist  for  1S72,  jjaj^e  •'>. 
t  AcconlinR  to  tlio  U.S.  Patent  Law,  an  invintor  haa  two  yours  njUr  the  lirst 
instrument  is  sold  in  wliirh  tu  apj)ly  for  a  patint. 


1064 


RECORD    OF    CURRENT    RESEA.RCHES   RELATING    TO 


Fig.  128. 


United  States  Patent  Office. 
Eobert  B.  Tolles,  of  Boston,  Massachusetts. 

Improvement  in  Microscopes. 

Specification  forming  part  of  Letters  Patent  No.  198,782,  dated  January  1,  1878  ; 
application  filed  July  27,  1877. 

To  all  whom  it  may  concern  : 

Be  it  known  that  I,  Egbert  B.  Tolles,  of  Boston,  in  the  County  of 
Suffolk  and  State  of  Massachusetts,  have  invented  certain  new  and 
useful  improvements  in  Microscopes,  of  which  the  following  is  a 
specification,  reference  being  had  to  the  accompanying  drawings, 
making  a  part  of  the  same,  in  which — 

Figure  128  represents  a  front  elevati  n  of  a  portion  of  a  Microscope- 
stand  with  my  improvements 
applied  thereto.  Fig.  129  re- 
presents a  side  elevation  of  the 
same.  Fig.  130  represents  in 
section  a  portion  of  the  sub- 
stage  detached.  Fig.  131 
represents  in  side  elevation  a 
portion  of  the  substage  illu- 
mination apj)aratus  detached 
and  drawn  upon  an  enlarged 
scale,  and  modified  by  con- 
necting with  it  a  graduated 
arc  ;  and  Fig.  132  represents 
in  end  elevation  the  parts 
shown  in  Fig.  131. 

My  invention  relates  to 
the  combination  of  a  circular 
track  in  a  plane  parallel  with 
the  optical  axis  of  the  instru- 
ment and  concentric  with  the 
object  to  be  examined,  with 
a  substage  carriage,  upon 
which  said  track  is  mounted 
and  carried  on  guides. 

It  also  relates  to  the  said 
circular  track,  provided  with 
graduations,  in  combination 
with  a  carriage  running 
thereon,  and  carrying  a  con- 
densing-lens  and  other  acces- 
sories, either  singly  or  com- 
bined. 

It  also  relates  to  a  holder 
to  carry  an  achromatic  illu- 
minator or  other  accessory,  in  combination  with  a  graduated  arc  and 
clamping  device,  to  fix  the  holder  at  any  angle  to  the  radius  that  may 
"be  desired,  or  in  the  radius  of  the  circular  track. 


/>  ^ 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1065 


It  also  relates  to  a  convex  lens,  either  plano-sphcrical  or  piano- 
cylindrical,  in  combination  with  a  plano-concave  lens,  that  can  be 
caused  to  traverse  the  surface  of  the  plano-convex  lens,  and  an  illu- 
mination-tube to  direct  a  beam  of  liglit  through  tlie  plano-concave 
lens. 

It  also  relates  to  the  convex  lens  and  its  support  in  the  radius  of 
the  circular  track,  in  combination  with  an  illuminating  device. 

Fig.  12D. 


It  also  relates  to  a  graduated  circular  track  to  support  an  ilhimi- 
natiou-tubc  and  accessories,  with  tlie  stage,  to  support  the  object-slide, 
as  will  be  mon;  fully  described  hereiiiiifter. 

Ill  the  drawings,  the  base  or  stand  lias  jointed  to  it  a  curved  arm  A, 
upon  which  the  body  of  the  iustruinout  is  mounted.  It  also  carries 
the  stage  S,  upon  which  is  placed  the  object-slide  ('.  I)  represents  a 
circular  track  mounted  upon  a  substago  carriage  B,  connected  to  the 
arm  A.  This  circular  track  is  mounted  and  carried  on  or  within 
guides  in  a  plane  parallel  to  the  optical  axis  X  X  of  the  instrument 


1066 


RECORD    OF   CURRENT    RESEARCHES    RELATING   TO 


and  concentric  with  the  object  to  be  examined,  mounted  in  the  slide  C, 
so  that  whether  the  slide  be  above  or  below  the  stage,  the  object  it 
holds  shall  always  be  in  the  axis  of  said  circular  track  D.  This  track 
has  graduation-marks  placed  upon  it,  by  which  the  position  of  the 
carriage  P,  that  it  carries,  can  be  set  and  recorded.     It  may  also  be 


Fig.  130. 


Fig.  131. 


Fig.  132. 


Tised  without  graduations.  Upon  this  carriage  is  mounted  the  sub- 
stage  T,  carrying  the  holder  I,  to  which  is  screwed  the  illumination- 
tube  I',  or  other  accessories. 

The  spindle  of  the  holder  I  can  turn  in  its  socket,  and  be  clamped 
to  it  by  the  screw  t  in  any  position  in  which  it  may  be  placed,  to  carry 
an  achromatic  illuminator  or  other  accessory, 
either  in  the  radius  of  the  track  D,  or  at  any 
degree  of  obliquity  thereto ;  and  to  facilitate 
this  adjustment,  it  is  provided  with  an  index  M, 
resting  against  a  graduated  arc  i,  attached  to 
the  substage. 

The  apparatus  is  provided  with  a  convex 
lens  L,  either  j)lano-spherical  or  piano-cylindrical 
(the  plane  surface  of  either  being  modified  to 
concave  or  convex,  if  either  of  these  forms 
should  for  special  purposes  be  deemed  preferable 
to  a  plane),  and  a  plano-concave  lens  a,  the 
curvature  of  whose  concave  surface  is  the  counterpart  of  the  convex 
surface  of  the  lens  L,  the  lens  a  being  caused  to  traverse  the  surface 
of  the  lens  L  by  the  movements  of  its  carriage — in  this  instance  an 
arm  of  the  carriage  P,  which  latter  also  carries  an  illumination-tube  I', 
or  a  condenser  arranged  to  direct  a  beam  or  pencil  of  light  upon  the 
plane  face  of  the  lens  a.  The  convex  lens  L  is  mounted  upon  the 
axial  end  of  an  arm  n,  which  arm  is  in  the  radius  of  the  circular  track 
D,  and  is  also  carried  by  the  substage. 

Having  now  fully  described  my  invention,  I  claim — 

1.  The  combination  of  a  circular  track  D  in  a  plane  parallel  to 
the  optical  axis  XX  of  the  instrument  and  coincident  with  the  object 
to  be  examined,  with  a  substage  carriage  B,  upon  which  said  track  is 
mounted  in  a  plane  parallel  to  the  optical  axis,  substantially  as  shown 
and  described. 

2.  The   combination  of  a   graduated   circular   track  D,  with   a 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1067 

carriage  P  running  therein,  and  carrying  a  condensing-lens  and  other 
accessories,  either  singly  or  combined,  substantially  as  shown  and 
described. 

3.  A  turning-holder  I,  carrying  an  index  M,  in  combination  with 
a  graduated  arc  i,  and  a  clamping  device,  to  secure  the  holder  either 
in  the  radius  of  the  track  D  or  at  any  degree  of  obliquity  in  which  it 
may  be  placed,  to  carry  an  achromatic  illuminator  or  other  accessory, 
substantially  as  shown  and  described. 

4.  The  combination  of  a  convex  lens  L,  of  piano-spherical  or  suit- 
able form,  with  a  plano-concave  lens  a,  of  counterpart  curvature,  and 
a  carriage  P  carrying  said  concave  lens,  and  also  an  illumination- 
tube,  substantially  as  shown  and  described. 

5.  The  combination  of  a  convex  lens  L,  and  an  arm  n,  on  the 
axial  end  of  which  said  lens  is  mounted,  with  a  circular  track  D,  and 
carriage  P,  carrying  a  suitable  illumination  device,  substantially  as 
shown  and  described. 

6.  The  combination  of  a  graduated  circular  track  D,  and  carriage  P, 
for  guiding  and  supporting  an  illumination  device  and  other  acces- 
sories, with  a  stage  S  for  supporting  the  object-slide,  substantially  as 
shown  and  described. 

In  witness  whereof  I  have  hereunto  subscribed  my  name. 

Egbert  B.  Tolles. 
In  presence  of — 

P.  S.  Yendell, 
Abthub  MoNally. 

Bulloch's  Sector  Microscope.— The  next  in  order  of  date  is  the 
Microscope  shown  in  Fig.  133,  which  was  designed  by  Mr.  W.  H. 
Bulloch,  of  Chicago,  U.S.A.,  and  exhibited  in  1873. 

Tlie  figure  shows  the  general  design  of  the  Microscope.  The 
substage  was  described  by  Mr.  Bulloch  as  follows :  "  Compound 
substage,  with  the  most  complete  movements  for  centering  or  for 
oblique  light,  with  achromatic  condenser,  has  one-fourth  inch  move- 
ment each  way,  rack  and  i)inion  vertical  movement,  rack  and  pinion 
movement  in  arc  of  circle  for  oblique  liijht.  .  .  ." 

The  sectoral  arc  is  shown  in  the  figure  just  below  the  stage,  as  well 
as  the  rack  and  milled  head  of  the  pinion  by  which  the  substage  is 
moved.  The  mirror  is  on  a  separate  bar  and  can  bo  swung  above  the 
stage  and  clamped  by  a  screw,  the  milled  head  of  which  is  seen  at  the 
back  of  the  instrument. 

Zentmayer's  Centennial  and  Histological  Microscopes. — 
(1)  Ccntennidl. — This  ^Microscope,  sliown  in  Fig.  l.'U,  waslirst  exhibited 
at  the  Academy  of  Natural  Sciences  of  I'hiliidelpliia  on  April  2,  187G  • 
and  then  at  the  Phihul.'lphia  Centennial  Exliibition  in  187(5,  and  sub- 
se([Uontly  at  tho  Paris  Fxhil)ition  in  1878. 

The  following  is  j\[r.  Zoiitinayer's  de.seription  of  it.*  "  Tho  instru- 
ment is  I'J  inches  high  when  arranged  for  use.     It  is  mounted  on  a 

*  'IlluHtratrd  Prioo  Lisl.'  4tli  c<Ht. 


1068  RECORD    OF   CURRENT    RESEARCHES    RELATING    TO 

Fig.  133. 


Bulloch's  sector  microscope. 


INVERTEBRATA,    CRVPTOGAMIA,    MIOUOSCOPY,    ETC.  1009 

broad  tripod  base  with  revolving  platform,  bevelled,  silvered,  and  gra- 
duated in  degrees  for  measuring  the  angular  aperture  of  achromatic 
objectives.  Upon  this  platform  are  two  pillars,  between  which  the  bar 
and  trunnions  (which  are  of  one  piece)  swing  for  inclining  the  instru- 
ment to  any  angle. 

The  coarse  adjustment  is  effected  by  rack  and  pinion.  The  fine 
adjustment  (in  all  other  instruments  of  the  Jackson  principle  in  front 
of  the  body)  is  removed  to  the  more  stable  part  of  the  instrument, 
the  bar,  which  is  provided  with  two  slides,  one  for  the  rack-and-pinion 
adjustment,  and  close  to  it,  another  one  of  nearly  the  same  length, 
for  the  fine  adjustment,  moved  by  a  lever  concealed  in  the  bent  arm 
of  the  bar,  and  acted  upon  by  a  micrometer  screw.  In  this  way  the 
body  is  not  touched  directly  when  using  the  fine  adjustment,  and 
the  body  does  not  change  the  relative  distance  of  objective,  bino- 
cular prism,  and  eye-piece.  (A  woodcut  of  the  fine  adjustment  will 
be  found  at  p.  321  of  vol.  ii.) 

The  sioinging  suhstage,  which  carries  the  achromatic  condenser  or 
other  ilhiminating  apparatus  and  the  mirror,  swings  ai'ound  a  pivot 
placed  behind  the  stage,  of  which  the  axis  passes  through  the  object 
observed,  so  that  the  object  is  in  every  position  in  the  focus  of  the 
illumination.  This  most  important  arrangement,  without  which  no 
Microscope  can  be  considered  complete,  is  carried  out  in  an  extremely 
simple  and  substantial  manner.  Although  provided  with  but  a  single 
joint,  it  admits  of  being  swung  over  any  of  the  stages ;  a  complete  revo- 
lution is  only  interfered  with  by  the  body  of  the  instrument.  It  is 
provided  with  a  graduated  circle  at  the  upper  collar  for  registering 
the  degree  of  obliquity,  and  a  stop  to  indicate  when  it  is  central  with 
the  main  body. 

The  substage  is  divided  into  two  cylindrical  receivers,  to  facilitate 
the  adaptation  of  several  accessories  at  one  and  the  same  time.  The 
upper  cylinder  has  centering  adjustment,  the  lower  cylinder  of  the  two 
can  be  moved  up  and  down  or  entirely  removed. 

As  an  object  i)laced  on  the  stage  is  in  a  plane  with  the  axis  of  the 
trunnions,  it  is  obvious  that,  if  the  instrument  is  placed  in  a  hori- 
zontal position,  the  object  is  in  the  axis  of  revolution  of  the  graduated 
platform,  and  tlie  angular  a2)crturo  of  an  objective  focusscd  on  this 
object  can  be  easily  measured.  It  can  be  readily  seen  that  in  tliis 
position  the  obj(!ct  is  in  tlie  centre  of  all  the  revolving  parts  of  tlic 
instrument,  the  revolving  stage,  swinging  substage,  and  the  platform." 

There  are  three  Stages:  Ist.  One  devised  by  Mr.  Zentmayer  in 
l.Sr.2  (sliown  in  position  on  the  stand,  Fig.  131),  which  is  5^  inches 
in  diuiiictcr  and  i  inch  in  thickness.  "  It  consists  of  a  bell-metal  ring, 
firmly  attached  to  the  bar,  l)ut  ailjustalde  by  means  of  set  screws,  in 
order  to  niukc  it  perfectly  (•(tncentric  to  tli(>  optical  axis  of  the  instru- 
ment. This  ring  nceivcs  the  stag(^  platform,  which  has  a  complete 
rcv(dution.  Tlio  outer  edge  is  bevelled,  silvered,  and  graduated  into 
degrees  to  serve  as  a  goniometer.  The  carriage  on  whieli  tlu^  object 
is  placed  rests  on  a  piece  of  plate  glass,  kej)t  down  by  a  spring  with 
an  ivory-pointed  screw  to  the  two  rails  on  the  revolving  stage  plat- 
forni,  whicli   gives  an  exceedingly  smooth  and  firm  niov<;nient,  and  a 

VOL.    III.  1    B 


1070     RECORD  OF  CURRENT  RESEARCHES  RELATING  TO 

Fig.  134. 


ZKNTMAYEU  S    CKNTEXNIAl,    MICKOSCOPK. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1071 


freedom  of  motion  not  obtained  by  any  other  arrangement.  Owing  to 
its  simplicity,  convenience,  and  durability,  it  has  been  extensively 
copied  at  home  and  abroad.    The  stage  may  be  detached  with  facility, 

Fig.  135. 


by  simply  unscrewing  the  nut  at  the  back  Fig.  136. 

of  the  bar,  to  be  replaced  by  another 
stage,  as,  for  instance,  the  Mechanical 
stage  or  the  Diatom  stage." 

2nd.  The  Mechanical  stage  (Fig.  135, 
lialf-size)  is  4  inches  square  and  -^^ 
inch  thick,  with  rectangular  movements 
of  1  inch  by  the  milled  heads  shown 
on  the  right  and  left.  The  forward 
motion  of  the  stage  is  by  means  of  a  fine 
chain  winding  on  a  spindle  beneath  the 
stage  acted  on  by  the  outer  milled  head, 
and  is  provided  with  a  set-screw  by 
which  any  stretching  of  the  cliuin  can  be 
at  once  compensated.  The  cross-motion 
is  effected  by  a  travelling  scrow-sockot 
attached  beneath  the  stage,  acted  on  by 
the  inner  milled  head.  These  movements 
are  extremely  well  constructed  by  Mr. 
Zentmaycr.  The  graduated  scales  shown 
at  tlie  base  serve  as  a  finder. 

The  central  circular  plate  (graduated  at  the  margin)  rotates  in  tho 
jdane  of  tlio  stage,  an<l  is  provided  with  two  clips  for  the  object. 
Inasmuch  as  this  rotating  cciitre-pieco  moves  out  of  centre  with  every 

•1   n  2 


1072 


KECORD    OF    CURRENT    RESEARCHES    RELATING   TO 


toucli  of  tlie  rectangular  motions,  the  iitility  of  the  rotation  is  very 
much  curtailed ;  a  rotatory  motion  of  the  stage,  unless  it  be  approxi- 
mately concentric  with  the  optic  axis,  appears  to  us  to  be  practically 
useless. 

3rd.  The  Diatom  stage  (Fig.  136,  half-size)  is  2^  inches  in  diameter 
and  is  bevelled  out  beneath,  so  that  its  thickness  is  only  ^^  inch  at 


Fig.  137 


the  centre.  The  lower  plate  rotates  in  the  ring  of  the  stage,  and  the 
upper  one  can  be  slipped  backwards  and  forwards  (beneath  the  spring 
clips)  in  two  grooves.  The  four  adjusting  screws  for  centering  are 
shown  in  the  figure.  Owing  to  its  small  size,  it  is  very  solid ;  it  is 
especially  convenient  in  that  the  swinging  substage  can  be  moved 
almost  to  the  horizon  of  the  object. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC.  1073 

All  of  the  stages  are  reversible  on  the  stand,  thus  admitting  of 
unlimited  obliquity,  and  still  keeping  the  object  in  the  centre  of  the 
swinging  bar. 

(2)  Histological. — This,  constructed  in  1876  (Fig.  137),  shows  the 
adaptation  of  the  swinging  substagc  to  a  cheai)  form  of  Microscope, 
and  was  earlier  in  date  to  that  which  wo  recently  described  at  p.  532 
as  being  the  first  cheap  form  that  we  had  seen. 

Mr.  Zentmayer  also  constructed  two  other  forms  intermediate 
between  this  and  the  Centennial  ("  U.S.  Army  Hospital  stands  "). 

Bulloch's  Congress  and  Biological  Microscopes.  —  (1)  Congress 
{older  form). — -In  1877  the  form  shown  in  ^  scale  in  Figs.  138  and  139 
(19  inches  high)  was  brought  out  (patented  in  1879). 

The  figures  render  any  detailed  description  of  the  parts  of  the 
instruments  unnecessary,  with  the  exception  of  the  substage  and  mirror 
arrangements.  These  both  move  about  the  same  centre,  which  is  at  a 
jjoint  the  thickness  of  an  ordinary  slide  above  the  stage,  and  they  can 
be  rotated  by  hand  above  and  below  the  stage  either  together,  when 
connected  by  the  spring  stop  S  (Fig.  138j,  or  separately  (as  shown  in 
Fig.  139). 

The  two  arms  (DD  and  0  E)  carrying  the  substage  and  the 
mirror  are  attached  to  the  graduated  cii'cles  shown  in  the  figure,  by 
which  the  exact  degree  of  obliquity  can  be  registered. 

As  originally  constructed  by  Mr.  Bulloch,  the  end  of  the  substage 
pinion  (passing  through  the  limb)  was  provided  with  a  toothed  wheel 
A,  upon  which  the  tangent  screw  B  acted,  producing  the  lateral 
rotation  of  the  substage  bar.  This  mechanical  rotation  has  since  been 
replaced  by  friction  motion  that  can  be  clamped  by  the  milled  head 
shown  on  Fig,  140  in  the  place  of  A  in  Fig.  138. 

When  placed  horizontally  as  f(U'  drawing,  every  part  moves 
accurately  about  the  same  centre  X  (in  direct  line  with  the  object  on 
the  stage). 

The  fine  adjustment  is  on  the  Franco-German  princii)le,  and 
moves  the  entire  body  without  changing  the  distance  between  the 
objective  and  the  cyc-piccc.  The  levers  11  II  act  directly  upon  the 
sliding-box  wliicli  contains  the  pinion  of  the  coarse  adjustment,  and 
this  is  in  turn  pressed  down  by  a  strong  spiral  spring  J  above  it.  In 
addition  (wliich  is  important  with  tliis  form  of  fine  adjustment)  the 
Society  screw  at  the  end  of  the  body  is  nrrimged  as  a  safety  nose- 
piece  K  with  spring.  The  arnuigcnu^nt  of  this  form  of  fine  adjust- 
ment difiers  from  that  of  Mr.  Zentmayer,  as  the  latter  uses  an 
independent  slide  for  the  coarse  and  for  the  fine  adjustment,  and  not 
one  slide  for  btitli. 

Heretofore  in  centering  the  stage  to  the  optical  axis  it  has  been 
d(mc  by  a  ring  within  aiiotlier  one,  in  which  the  screws  (»perate  eitlier 
to  draw  or  pusli  the  iuttTior  ring  into  position.  By  this  metliod  the 
stage,  in  order  to  uso  it  for  obliipu!  light,  has  to  bo  made  inincces- 
sarily  largo.  In  place  of  a  complete  ring.  ]Mr.  Bulhxdi  therefore 
uses  a  segment  or  "  saddlu  piece,"  to  which  tlie  stage  ring  is  attached. 
Tlie  amingcment  is  sliown  in  the  upper  section  of  Fig.  l;!8,  where  F 
is  the  saddle-pieie,  witli   tlie  four  centering  screws  putisiug  through 


1074  RECORD    OF    CURRENT    RESEARCHES   RELATING   TO 

138. 


bclloch's  congress  microscope  (older  form). 


INVERTEBRATA,    CRYPTOaAMIA,-  MICROSCOPY,    ETC.  1075 

Fig.  130. 


liriliMiis   rnNi;nE.NS    Micuosn  H'K   ((iI.uki;    iiiKJO. 


1076  RECORD    OF    CURRENT    RESEARCHES    RELATING   TO 

it,  beiug  firmly  fastened  to  the  limb.  Tlie  ring  may  be  clamped  in 
any  position  by  a  screw  passing  through  the  base  of  F,  and  the  stage 
may  be  clamped  in  any  position  by  M.  The  projections  at  N  (and  M) 
afford  bearings  for  the  stage  to  move  upon  and  diminish  friction. 

The  stage  is  thin  enough  to  admit  oblique  light  up  to  134°. 

(2)  Congress  (neiver  form). — Mr.  Bulloch  writes  :  "  I  have  recently 
made  several  improvements  and  additions  to  the  stand. 

"  As  originally  intended,  the  front  end  of  the  centre  of  the  substage 
passed  through  and  supported  the  stage  support  or  saddle-piece ;  but 
for  the  finer  work  of  measuring  angles  of  aperture  as  Dr.  Blackham 
does,  any  connection  between  substage  and  stage  would  cause  the 
object  to  move  to  one  side  when  the  substage  was  swung  from  one 
side  to  the  other ;  as  now  made  there  is  no  connection  between  sub- 
stage  or  mirror  and  the  stage ;  the  stage  is  fixed  to  the  limb  by  an 
angle-piece  quite  independent  of  the  swinging  arms,  which  I  consider 
an  imi)()rtant  improvement.     (Cf.  Figs.  140  and  141.) 

"  I  have  also  improved  the  arrangement  of  the  pinion  box ;  the 
slide  of  the  coarse  adjustment  is  now  provided  with  a  V  piece  on  each 
side  of  the  rack-work,  and  these  fit  into  corresponding  slots  :  they  act 
as  guides  to  the  movement  and  add  to  the  steadiness.  I  have  also 
added  guide  pieces  outside  the  pinion  box,  that  travel  with  the  fine 
adjustment  on  the  sides  of  the  limb.  (Cf.  Figs.  140  and  141 :  they  are 
shown  above  and  below  the  large  milled  heads  on  the  limb.) 

"  In  the  end  of  the  tube  is  the  new  broad-gauge  screw  (the  '  Dr. 
Butterfield  broad-gauge  screw '),  1^  inch  in  diameter,  for  low-power 
objectives  of  extra  high  angle.  In  this  screw  are  two  separate 
nose-pieces  containing  the  Society  screw — one  is  for  the  binocular, 
which  must  have  diaphragms,  so  that  the  full  benefit  of  high  angle  is 
lost ;  the  other  has  a  clear  aperture,  the  diameter  of  the  Society 
screw. 

"  At  the  upper  end  of  the  slide  of  the  tube  is  a  scale  reading  to  yi^ 
of  an  inch,  and  the  slow-motion  screw  reads  to  yoVo'  ^^  ^^^^  working 
distance  of  objective  can  be  measured. 

"  There  is  also  what  I  call  a  new  adaptation  of  the  Gillett 
diaphragm,  which  can  be  used  close  up  to  the  object,  or  when  using 
the  hemispherical  lens  can  be  swung  close  round  it.  The  Woodward 
prism  and  also  the  hemispherical  lens  are  specially  fitted  to  the 
imder  part  of  the  stage  support,  so  that  the  stage  can  be  revolved  in 
the  axis  without  altering  the  position  of  the  hemisphere." 

Of  the  points  mentioned  in  Mr.  Bulloch's  letter,  we  must  certainly 
agree  with  him  as  to  the  importance  of  making  the  attachment  of  the 
stage  substantial  and  rigid,  as  may  doubtless  be  done  by  screwing  it 
to  the  limb  by  an  angle-piece.  If  it  were  desired  to  have  a  second 
stage  adapted — say  a  small  diatom  stage — it  would  be  quite  possible 
to  provide  convenient  means  for  changing  the  stage,  and  at  the  same 
time  to  ensure  that  either  stage  should,  when  in  position,  be  exactly 
at  right  angles  to  the  optic  axis. 

Still  later  Mr.  Bulluch  has  modified  the  stand  to  make  it  more 
especially  applicable  for  the  examination  of  diatoms.  The  stand  is 
shown  in  Figs.  140  and  141,  the  latter  being  a  representation  of  the 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1077 


instrument  in  a  horizontal  position  (with  the  lamp  attached  to  the 
substage  bar)  for  drawing,  measuring  apertures,  &c. 

Mr.  Bulloch  claims   to   have  improved  the  construction  of  the 


Fig.  140. 


sliding  ghiss  sUigt^  ;  as  jiroviously  niiul»\  tlicro  was  ulwiiys  a  liability 
to  II  siiililcii  slipping  of  tli(!  slug*'  if  tlif  jNIicrosfopo  wcrr  acridrntally 
jiirrod.      I>v  using  two  pressure  points  iittod  on   one  bar  that  turns  on 


1078 


KECOKD    OF    CUKRENT    EESEARCHES    RELATING    TO 


a  swivel  joint,  the  swivel  accommodates  for  any  difference  of  length 
in  the  points  and  thus  equalizes  the  pressure  and  prevents  slipping. 
The  stage  is  thin  enough  to  admit  an  angle  of  160  degrees. 

The  substage  is  made  in  two  parts,  intended  for  the  examination 
of  polarizing  objects  when  using  an  achromatic  condenser.  The 
lower  part  has  a  motion  to  one  side,  which  leaves  the  condenser  and 
light  from  the  mirror  in  the  same  position.  Fig.  140  shows  the 
lower  part  swung  out. 

The  Gillett  diaphragm  to  the  condenser — placed  above  the  lenses — 

Fig.  141. 


is  also  shown,  and  a  convenient  plan  for  mounting  a  hemispherical  lens 
for  immersion  illumination  attached  to  an  elbow-piece  beneath  the 
stage. 

(3)  Biological. — This  (Fig.  142)  is  a  smaller  and  more  recent 
instrument  (patented  in  1879). 

The  substage  and  mirror  can  be  moved  indei^endently  round  the 
focal  point  as  a  centre,  and  can  be  used  above  the  stage  if  required. 


INVERTEBRATA,    CRYPTOGAMIA,    MICROSCOPY,    ETC. 


1079 


They  can  also  be  clamped  in  any  position  by  the  milled  head  shown 
behind  the  limb. 

The  stage  (with  revolving  concentric  movement)  is  adjustable  to 
the  axis,  measures  3  5  inches  in  diameter,  and  is  3^  inches  above  the 

Fio.  142. 


tiibhi.  Wliuu  iiol  rcMiuircd  to  revulvc,  it  can  hv  chiiiipfd  in  any 
jJOfiition  by  the  milled  head  shown  in  front.  When  there  is  any 
daiig(!r  of  injuring  the  stage  by  the  use  of  acids,  it  can  be  lifted  out  of 
the  ring  in  which  it  revolves,  and  an  ordinary  piece  of  glass  used  on 


1080  RECORD    OF    CURRENT    RESEARCHES   RELATING   TO 

the  top  of  the  ring  when  the  instrument  is  upright.  The  stand  is 
12i  inches  in  height,  and  the  body  and  draw-tube  are  each  5  inches 
in  length.  The  fine  adjustment  moves  the  whole  body-tube,  and  there 
is  the  broad-gauge  screw  for  high-angle  low-power  objectives,  in 
which  fits  an  adapter  with  the  regular  Society  screw. 

Other  details  are  shown  in  the  figure,  which  is  about  two-fifths  the 
actual  size  of  the  instrument. 

Standards  of  Length— Uluminatioii  for  Opaque  Objects.* — 
Professor  "W.  A.  Rogers  has  T)ublished  an  exhaustive  paper  on  those 
standards  of  length  which  are  in  actual  use,  and  which  have  the 
authority  and  sanction  of  either  national  or  international  law.  Much 
of  the  paper  is  beyond  our  scoj^e ;  but  the  author  refers  to  two  points 
bearing  upon  the  use  of  the  Microscope  in  verifying  standards. 

With  regard  to  the  magnifying  power  of  the  Microscope  employed, 
which  is  best  adapted  to  secure  the  greatest  absolute  accuracy  in 
measurements,  the  result  of  the  author's  experience  on  the  subject  is 
favourable  to  high  powers.  With  a  proper  illumination,  and  with 
lines  having  smooth  edges,  a  power  of  900  can  be  used  with  great 
ease,  even  in  the  comparison  of  two  metres  upon  a  longitudinal  com- 
parator. In  all  the  earlier  comparisons  Microscopes  of  very  low  power 
were  employed,  varying  from  10  to  60  diameters,  and  the  International 
Commission  have  decided  upon  the  low  power  of  40  to  50.  M.  Tresca, 
of  the  French  section,  however,  is  a  firm  believer  in  high  powers,  and 
prefers  one  of  about  400. 

On  the  best  method  of  illumination  for  opaque  objects,  Professor 
Eogers  says — "  I  cannot  better  illustrate  the  necessity  for  a  proper 
illumination  in  making  exact  measurements  than  by  saying  that  I  have 
been  obliged  to  reject  a  series  of  observations,  extending  over  a  period 
of  four  months,  for  the  simple  reason  that  I  finally  discovered  that, 
during  all  this  time,  I  have  never  once  seen  the  actual  lines  ruled,  but 
only  their  image.  I  used  a  parabolic  reflector,  giving  a  beautiful 
white  line  on  a  black  background.  The  lines  were  traced  upon  a  steel 
surface,  nickel-plated,  their  width  being  about  one  ten-thousandth  of 
an  inch.  Investigation  showed  that  the  positions  of  the  lines  could 
be  changed  by  an  amount  more  than  half  their  width,  by  shifting  the 
position  of  the  parabolic  reflector. 

The  method  of  illuminaticm  employed  by  Baily  and  Sheepshanks 
seems  to  me  radically  defective.  With  the  Microscopes  used  by  Sheep- 
shanks I  found  myself  unable  to  separate  lines  ruled  on  a  polished 
steel  plate,  though  sepaiated  by  an  interval  of  only  one-thousandth  of 
a  centimetre.  As  already  stated,  I  have  used  with  great  satisfaction 
the  form  of  illumination  described  by  Mr.  Tolles  in  the  '  Annual  of 
Scientific  Discovery'  for  1866-67. f  It  is  sufficient  to  say  here,  that, 
as  none  of  the  light  is  lost  by  the  reflection,  it  is  easy  to  get  all,  and 
even  more  than  is  needed.  Diflused  daylight  falling  upon  the  j)lane 
face  of  the  prism  inserted  between  the  two  front  lenses  afibrds  an 
abundance  of  Kght  for  the  most  delicate  tracings.    With  a  1-inch  objec- 

*  'Proc.  Am.  Acad.  Arts  and  Sci.,*  xv.  (1880)  pp.  273-312. 
t  See  this  Journal,  ante,  p.  7.54. 


INVERTEBRATA.    CRYPTOGAjMIA,    jnCROSCOPY,    ETC. 


1081 


Fig.  143. 


tive  of  the  form  recently  constructed  ])y  Mr.  Tolles,  lines  30,000  to 
the  inch,  ruled  on  a  polished  steel  surface,  are  resolved  with  the 
greatest  ease." 

Professor  Rogers  also  refers  to  a  "  comparator  "  which  he  has 
designed  as  an  improvement  upon  that  described  at  p.  947  of  vol.ii.,  a 
description  of  which  we  defer  until  a  detailed  account,  with  a  draw- 
ing, has  appeared. 

Mirror  for  Illuminating  Opaque  Objects  for  the  Projecting 
Microscope.* — Tlie  subject  of  this  note,  by  Mr.  P.  Frazer,  jun., 
(which  we  give  verbatim)  "  is  an  arrangement  for  representing  opaque 
objects  through  the  gas  Microscope,  especially  adapted  to  Zentmayer's 
Iji-inch  objective.  It  is  only  claimed  to  be  better  than  the  para- 
bolic reflector  of  Smith  and  Beck, 
J.  Lawrence  Smith,  Sorby,  and 
others,  where  the  working  distance 
of  the  Microscope  is  comparatively 
large  (i.  e.  the  distance  from  the 
objective  to  the  object  on  the  stage 
is  i  inch  or  more)  and  for  the 
purposes  mentioned.  Where  the 
distance  is  as  great  as  that  just 
mentioned,  the  dispersion  of  rays 
from  the  reflection  at  one  point,  of 
rays  from  very  different  parts  of 
the  mirror,  is  so  great  that  only  a 
few  rays  from  the  upper  part  of 
the  mirror  reach  the  lens  at  all. 
It  would  be  different  with  a  lens 
having  a  very  small  working  dis- 
tance, and  in  this  case  a  parabolic 
reflector  would  be  preferable. 

The  apparatus  consists  of  a 
brass  tube  made  to  slide  over  the 
lens,  on  the  lower  end  of  which  is 
fixed  a  glass  plate  about  1  mm.  in 
thickness,  so  attached  as  to  be 
capable  of  a  sliding  motion  to- 
wards or  away  from  the  hinged 
mirror  which  is  attached  to  the 
edge  of  the  metal  flange  in  which 
the  glass  plate  slides.  This  simple 
contrivance  porniits  the  glass  plate  to  be  brought  into  close  contact 
with  the  rtflf'cting  mirror,  no  matter  at  what  angle  the  latter  may  bo 
placed. 

The  mirror  is  made  of  nickol-platcd  German  silver  neatly  mounted 
on  a  small  hinge. 

The  liglit  is  admitted  from  Ixlow  through  a  diapliragni  aftt>r  the 
rays  have  been  rendered  parallel  by  the  condenser  of  the  lantern,  the 

•  '  Vroc.  Am.  Phil.  Sfw-.  riiiln.,'  xviii.  (ISSO)  |..  .'■>03. 


G  V,  cover-n;la.'«8.  BF  N.  rt  fleet- 
ing mirror.  U  1'  K,  reflcctidii  on  object. 
L',  raj'H  which  pass  througli  the  oltjoc- 
tivc.  D,  leiiH.  T,  sliding  tube  carrying 
roflecting  mirror.  Angle  of  inoitlenc« 
G2°. 


1082  RECORD    OF    CURRENT    RESEARCHES,    ETC. 

aperture  of  tlie  diapliragm  being  adapted  to  the  maximum  thickness 
of  beam  which  can  be  effective  for  illumination,  and  which  (calling  a 
the  aperture  of  the  lens  and  i  the  angle  of  incidenc3  of  the  beam) 
=  a  cos.  i  ;  or  for  an  aperture  of  f  inch  (  =  0*875  inch)  and  an  inci- 
dent angle  of  62°,  0"4:11  inch,  or  roughly  0*4  inch. 

The  less  the  incident  angle,  of  course  the  larger  the  beam  of  light 
will  be,  and  the  greater  the  diameter  of  the  diaphragm.  The  refractive 
index  of  the  glass  employed  to  make  the  plate  beiug  1  •  5,  in  order 
that  the  critical  angle  41°  48'  may  not  be  exceeded  in  the  refracted 
ray,  this  angle  of  incidence  or  i  must  not  be  less  than  61°  51',  or 
roughly  62°. 

This  minimum  value  of  i  determines  the  area  of  surface  which 
can  be  illuminated  on  the  Microscope  stage,  but  by  altering  the  angle 
of  the  mirror  very  slightly,  all  parts  of  the  object  may  be  successively 
projected  on  the  screen.  This  minimum  value  is  easily  obtained 
from  the  critical  angle  of  the  glass  employed,  which  is  41°  48'.  The 
complement  of  this,  or  48°  12',  is  equal  to  the  angle  of  refraction 
(or  r)  when  the  minimum  value  of  i  is  attained. 

'4^^'-  1-5, 
sin.  /• 

sin.  8  =  1-5  (sin.  48°  12'), 

i  =  er  51'. 

In  other  words,  the  angle  between  the  luminous  ray  and  the  glass 
plate  can  never  exceed  28°  09',  or  in  round  numbers  28°." 

Ebonite  in  Microscopical  Appliances. — In  America  ebonite  has 
been  adopted  for  some  years  for  mounting  eye-pieces,  and  for  stages 
of  laboratory  Microscopes,  principally  by  the  Bausch  and  Lomb 
Optical  Company,  who  claim  for  it  sjijecial  adaptability  for  these  pur- 
poses as  well  as  economy.  M.  Verick,  of  Paris,  has  also  used  it  for 
the  diagonal  sliding-boxes  containing  the  prisms  of  his  binocular  eye- 
piece and  the  outer  plates  into  which  they  fit,  and  it  has  also  been 
adopted  for  rings  for  cells. 

We  are  glad  to  see  that  ebonite  is  coming  into  use  in  this  country, 
having  been  adopted  for  Stephenson's  safety-stage*  (by  Mr.  Teesdale), 
and  now  for  Botterill's  life  trough, f  There  are  many  other  pieces  of 
apparatus  for  which  the  use  of  ebonite  would  be  a  great  advantage  in 
reducing  weight. 

*  See  this  Journal,  ante,  p.  332.  f  Ibid.,  p.  148. 


(     1083    ) 
PROCEEDINGS  OF  THE  SOCIETY. 


Meeting  of  13th  October,  1880,  at  King's  College,  Strand,  W.C, 
The  President  (Dr.  Beale,  F.E.S.)  in  the  Chair. 

The  Minutes  of  the   meeting   of  9th  Juno   last  were  read   and 
confirmed,  and  were  signed  hy  the  Chairman. 


The  List  of  Donations  (exclusive  of  exchanges  and  reprints) 
received  since  the  last  meeting  was  submitted,  and  the  thanks  of  the 
Society  given  to  the  donors. 

From 
Blackham,  G.  E.— On  Angular  Aperture  of  Objectives  for 

the  Microscope.     21  pp.  and  18  plates.      (8vo.     New 

York,  1880.) The  Author. 

Braithwaitc,  R. — The  Sphagnaccse  or  Peat  Mosses  of  Europe 

and   North   America.      91    pp.   and   29   plates.      (8vo. 

London,  18S0.)      Ditto. 

Cunningham,   D.    D. — On   certain  effects  of  Starvation   on 

Vegetable  and  Animal  Tissues.      47  pp.  and  11   figs. 

(4to.     Calcutta,  1879.)        Ditto. 

Lewi.s,  T.    R. — The    Microscopic   Organisms   found   in   the 

Blood  of  Man  and  Animals,  and  tlieir  relation  to  Disease. 

91  pp.  and  3  plates  and  27  figs.     (4to.     Calcutta,  1879.)  Ditto. 

Mandl,  L. — Anatomie  Micro.scopique.  2  vols.   pp.  3U8,  92  and 

54,  412  and  40.   Plates  52  and  40.   (Fol.   Paris,  1838-47, 

1848-57.)       Dr.  Carpenter,  C.B. 

Ranvier,  L. — Lemons  d'Anatomie  Ge'ne'rale  sur  le  Systeme 

Musculaire.     4Gr.  pp.  and  99  figs.     (8vo.     Paris,  18S0)  . .     3fr.  Crisp. 

Fungus?  on  Human  Hair Mr.  G.  C.  Morris. 

Section  of  P^lectric  Organ  of  the  Ray        Dr.  B.W.  Richardson. 

Slide  and  Packets  of  the  Llyn  Arcnig  Bach  Diatomaceous 

Deposit Dr.  H.  Stoltcrfoth. 

The  President  called  particular  attention  to  the  two  volumes  of 
'  Mandl's  Microscopic  Anatomy '  presented  to  the  Society  by 
Dr.  Carpenter  (reading  to  the  Meeting  the  letter  which  accompanied 
tho  donation),  and  lutjvcd  a  special  vote  of  thanks  to  Dr.  Carpenter, 
which  was  carried  unanimously. 


Mr.  Crisp  cxLibitcd  and  described  Waech tor's  Demonstrating 
Microscope  and  Wasserlein's  Saccharimctcr-Microscope,  and  exhibited 
Professor  Huxley's  Dis.secting  Microscope  (see  p.  705),  Tescliner's 
Trichina-Microscoi)o  (see  p.  715),  tho  two  shown  at  pp.  882  and  883 
(Figs.  97  and  98),  and  another  of  VVaechter's,  with  fine  adjustment  on 
the  same  plan  as  Seibcrt  and  KraOt's,  Figs.  99  and  100,  p.  883. 

Mr.  Swift  exhibited  and  described  a  l^Iicroscopc  with  radial 
traversing  substago  illumiimtor  (see  p.  8G7). 

Mr.  Crisp  pointed  out  that  tho  speciality  of  tho  instrument 
consisted,  1st,  in  its  having  tioo  sectors  at  right  angles ;  2ud,  in  tho 


1084 


PROCEEDINGS    OF    THE    SOCIETY. 


reduced  size  of  the  condensers ;  and  3rd,  in  the  sectors  being  remov- 
able, so  that  they  could  be  replaced  by  the  ordinary  substage  if 
desired.  

Mr.  Jno.  Mayall,  jun.,  exhibited  "  the  Thury-Nachet  Traverse 
Substage,"  one  of  the  earliest  forms  of  what  was  now  called  the 
"  Swinging  Substage  "  (made  by  M.  Nachet  in  1855  for  M.  Thury), 
and  described  the  peculiarities  of  its  construction  (see  p.  1059). 


Mr.  Crisp  exhibited  and  described  Messrs.  Parkes's   frog-plate 
(see  p.  1041).  

Mr.  Teesdale's   description   of  the  Pearson-Teesdale   microtome 
was  read,  and  the  instrument  exhibited  (see  p.  1034). 


Mr.  G.  C.  Morris's  letter  as  to  what  was  supposed  to  be  a  fungus 
on  human  hair  was  read,  together  with  a  communication  from  Dr. 
Cooke,  to  whom  the  specimens  had  been  submitted. 


Lr.  Stolterfoth's  paper  "  On  the  Diatomacere  in  the  Llyn  Arenig 
Bach  Deposit "  (see  p.  913)  was  read,  and  a  slide  in  illustration 
exhibited.  Several  packets  of  the  deposit  referred  to  were  also 
placed  upon  the  table  for  distribution  amongst  the  Fellows. 

Dr.  Matthews  said  that  he  visited  the  place  some  few  years  ago, 
and  then  found  some  pipe-clay  works  upon  the  spot.  No  one  at  that 
time  thought  that  the  deposit  was  diatomaceous  earth,  but  pipe-clay, 
and  it  was  used  as  such. 

Mr.  Crisp  read  some  recent  communications  from  Prof.  Hamilton 
L.  Smith,  in  which  he  recommended  the  abandonment  of  the  wax  cell 
(see  p.  861),  and  the  use  of  paper  dipped  in  shellac  varnish  for 
making  rings  (see  p.  1038). 

Mr.  James  Smith  said  he  had  described  these  rings  some  fifteen 
years  ago,  and  a  notice  of  it  appeared  in  the  '  Transactions '  at  the 
time  (see  p.  1039). 

Dr.  Braithwaite  said  he  had  used  them  twenty-five  years  ago. 


Mr.  Stewart  described  the  observations  of  M.  Eobin  on  a  species 
of  Podophrya  (see  p.  817),  in  connection  with  Mr.  Badcock's  paper  on 
Acinetina  (see  j).  561),  and  drew  figures  in  illustration  on  the  board. 


Mr.  A,  A,  Bragdon's  letter  on  fluid  for  homogeneous-immersion 
objectives  was  read  (see  p.  1051),  and  a  discussion  enstied,  in  the 
course  of  which 

Mr.  T.  Powell  said  it  was  his  decided  opinion  that  such  objectives 
were  better  constructed  with  a  collar  adjustment ;  if  made  so  as  to  be 
at  the  right  jjoint  when  the  collar  was  screwed  home  they  could  not 
go  far  wrong  ;  and 

Mr.  Stephenson  again  reminded  the  Meeting  that  if  the  objects 


PROCEEDINGS   OF   THE    SOCIETY.  1085 

were  in  air  and  non-adherent  to  the  cover,  a  homogeneous-immersion 
objective  was  no  better  than  a  water  objective,  as  the  aperture  was  at 
once  cut  down  to  the  equivalent  of  180^  in  air.  The  whole  benefit 
of  the  oil-immersion  was  thus  entirely  lost. 


The  following  Objects,  Apparatus,  &c.,  were  exhibited:— 

Mr.  O.  Brandt : — Slides  of  diatoms  arranged  by  E.  Getschmanu. 

Mr.  Crisp  : — The  seven  Microscopes  mentioned  on  p.  1083. 
„  Parkes's  frog  plate  (see  \x  1011). 

„  Webb's  finder  (see  p.  750). 

Mr.  J.  Mayall,  jun. : — The  Thury-Nachet  Traverse  Substage  (see 
p.  1059). 

Mr.  G.  C.  Morris: — Fungus  (?)  on  human  hair. 

Dr.  B.  W.  Richardson : — Section  of  electric  organ  of  the  Ray. 

Dr.  H.  Stolterfoth  : — Slide  of  the  Llyn  Arenig  Bach  Diatomaceous 
Deposit  (see  p.  913). 

Mr.  Swift : — Microscope  with  radial  traversing  substage  illumina- 
tor (see  p.  867). 

Mr.  Teesdale  : — New  (Pcarson-Teesdale)  microtome  (see  p.  1034). 


New  Fellows: — The  following  were  elected  Ordinary  Fellows  : — 
Messrs.  Thomas  Goodwin,  J.  Sibley  Hicks,  L.R.C.P.,  J.  Buxton 
Payne,  and  J.  C.  Thompson  ;  and  Ex-officio  Fellow  : — The  President 
for  the  time  being  of  the  Manchester  Microscopical  Society. 


Meeting  of  10th  November,  1880,  at  King's  College,  Strand,  W.C. 
The  President  (Dr.  Beale,  F.R.S.)  in  the  Chair. 

The  Minutes  of  the  meeting  of  13th  October  last  were  read  and 
confirmed,  and  were  signed  by  the  President. 

The  List  of  Donations  (exclusive  of  exchanges  and  reprints) 
received  since  the  last  meeting  was  submitted,  and  the  thanks  of  the 
Society  given  to  the  donors. 

From 
Heurck,  H.  van.— Synopsis  rlos  Diatonu-os  de  Belgique.  Fasc. 

I  and  II.     Allan.     Plates  l-:]0.     (8vo.     Antwerp,  1«80)     The  Author. 
MiiUer,  N.  J.  C— Iliindl.iu-h  dcr  Botunik.     2"  Band.     2''- 

Theil.     482   pp.   and  227   plates.     (8vo.     Heidelberg, 

1880.)      Mr.  Crisp. 

Photograplis  of  Pleurosigma  angulatum  and  Frustulia  saxonica        Mr.  0.  Brandt. 
Santa  Monica  Earth,-  and  Section  and  Photographs  of  the 

San  Bernardino  Mefeorito     Mr.  If.  0.  flanks. 

"  Tripoli "  from  liichmond  liivor,  N.  S.  Wales       I'rof.  A.  Livcrsidge. 

Mr.  0.  Brandt's  letter  as  to  the  above  photographs  was  read  : — 
"  I  enclose  photograplis  of : — 

1.  Plcurosiyma    amjidntnm    W.    Smith,    from   a    preparation    of 
J.  D.  MitUcr,  Wedcl,  magnified  direct  2000  times  with   (rundlacli's 
VOL.   III.  4  C 


1086  PROCEEDINGS  OF   THE   SOCIETY. 

No.  VII.  immersion  and  amplifier  (concave  lens).     Distance  1  metre, 
central  illumination. 

2.  PJeurosigma  angulatum — the  same  frustule  magnified  direct 
5900  times  with  Gundlach's  No.  VII.  immersion  and  amplifier. 
Distance  3  metres,  central  illumination. 

3.  Frustulia  saxonica,  showing  lines  parallel  to  the  axis  of  the 
frustule,  magnified  direct  5000  times  with  Seibert  and  Krafi't's  new 
oil-immersion  objective. 

The  existence  of  these  lines  parallel  to  the  axis  of  the  diatom  is 
quite  new,  and  I  think  many  of  the  Fellows  will  be  interested  to  hear 
of  it.  It  seems  as  if  all  drawings  on  all  diatoms  come  back  to  crossed 
lines  or  circles,  and  as  soon  as  one  sort  of  lines  can  be  seen  the 
existence  of  others  crossing  the  same  can  be  guessed. 

We  are  now  trying  to  find  these  crossed  lines  in  AmpMjpleura 
pellucida. 

All  the  photographs  were  made  by  Carl  Gunther,  of  Berlin." 

Mr.  Jno.  Mayall,  jun.,  said  it  was  very  interesting  to  compare  the 
lithographs  published  in  the  'Monthly  Microscopical  Journal'  (1876) 
of  Dr.  Woodward's  photographs  of  Frustulia  saxonica  with  those  now 
shown.  Dr.  Woodward  was  at  first  doubtful  as  to  the  existence  of 
both  transverse  and  longitudinal  lines,  but  Mr.  Samuel  Wells,  of 
Boston,  afterwards  showed  them  very  distinctly,  though  not  so  well 
as  they  were  shown  in  the  photographs  before  the  meeting. 


Professor  R.  Hitchcock's  letter  was  read  as  to  the  publication  of 
Mr.  Habirshaw's  '  Catalogue  of  the  Diatomacese '  if  a  sufficient  number 
of  siibscribers  were  obtained. 


Mr.  Crisp  exhibited  and  described  the  following  nine  Microscopes  : 
— Beck's  Silk  Mercer's,  Swift's  ditto,  Holmes's  Demonstrating,  Nachet's 
"  Snufi"  Box,"  Parkes's  English  Medical  with  sliding  adapters  for  the 
objectives  (see  p.  1048),  and  a  small  form  of  simple  Microscope  with  a 
mirror  made  in  Paris.  He  also  exhibited  a  Nachet  Microscope  to 
which  the  "  Thury-Nachet  Traverse  Substago"  (see  p.  1059)  had 
been  attached,  Sidle  and  Poalk's  Acme  Microscope  with  Iris  Dia- 
phragm (see  pp.  532  and  1053),  and  the  Tolles-Blackham  Microscope 
(see  p.  520).  

Dr.  W.  B.  Carpenter,  C.B.,  exhibited  and  described  the  "  Working 
Microscope  "  devised  by  Mr.  George  Wale,  an  American  manufacturer 
(see  p.  1045).  Being  struck  by  the  novelty  of  several  parts  of  the 
instrument,  he  had  thought  it  worth  while  to  get  one,  and  he  had 
no  hesitation  in  saying,  after  working  with  it,  that  it  combined  more 
good  points  than  any  student's  Microscope  which  he  had  yet  seen. 

The  first  point  was  the  method  of  susj^ension,  which,  instead  of 
being  on  the  usual  plan  of  a  swinging  centre  with  two  pivots,  con- 
sisted of  a  grooved  arc  moving  between  corresponding  curved  fillets 
on  a  central  support ;  the  foot  was  of  cast  iron  (together  with  the 
arc  carrying  the  body),  and   was  made  in   two  pieces,  on  each  of 


PROCEEDINGS    OF    THE    SOCIETY.  1087 

which  a  projecting  fillet  was  cast,  and  which  on  being  put  together 
allowed  the  arc  to  freely  move  between  them,  a  brass  set-screw 
enabling  it  to  be  clamped  rigidly  in  any  desired  position.  In 
this  way  the  Microscope  was  well  supported  without  any  tendency 
to  tilt  in  any  position.  The  next  point  was  the  fine  adjustment, 
which  was  made  upon  a  plan  which  he  believed  was  Mr.  Zentmayer's, 
but  it  was  one  wliich  made  it  impossible  for  there  to  be  any  twist. 
The  third  point  was  in  having  the  draw  tube  so  made  as  to  take  an 
objective  of  much  longer  focus  than  usual;  it  was  fitted  with  the 
Society's  screw,  and  would  also  take  an  amplifier  if  needed. 

The  stage  was  simply  a  round  plate  of  brass,  but  the  method  in 
which  the  fork  for  holding  the  object  was  fitted  to  the  stage  gave  it 
almost  the  advantage  of  a  revolving  stage.  The  mode  in  which  the 
mirror  was  hung  was  also  very  satisfactory  in  a  student's  Microscope, 
admitting  as  it  did  of  being  swung  laterally  in  either  direction,  and 
also — by  means  of  a  slide  in  the  bar  on  which  it  was  mounted — 
of  being  moved  up  near  to  the  objective  so  as  to  act  as  a  condenser. 
There  was  also  an  addition  to  the  Microscope  of  great  value,  viz.  an 
iris  diaphragm  (see  p.  1052)  of  very  simple  and  ingenious  construc- 
tion (described  and  figured  on  the  black  board). 

Altogether  the  instrument  was  one  which  much  pleased  him,  and  he 
had  brought  it  under  their  notice  in  the  hope  that  some  of  its  points 
might  be  taken  up  in  this  country,  where  the  demand  for  efficient 
student's  Microscopes  of  good  quality  was  becoming  so  great  that  it 
would  be  worth  while  for  any  maker  to  bring  out  the  best  that  could 
be  produced  at  a  moderate  cost.  This  Microscope  could  be  supplied 
in  New  York  at  about  71.,  but  he  thought  it  quite  probable  that  it 
might  be  made  here  for  say  IZ.  less. 

The  President  expressed  the  thanks  of  the  meeting  to  Dr. 
Carpenter  for  his  explanation. 

Dr.  Edmunds  pointed  out  that  this  most  useful  microscope-stand 
would  be  vastly  improved  if  only  the  arc  upon  which  the  body  turns 
were  so  constructed  tliat  the  centre  of  the  circle  of  which  the  arc 
forms  part  wore  made  to  coincide  in  position  with  the  centre  of  the 
stage.  The  object  then  would  undergo  no  movement  of  translation, 
either  in  rotating  the  stage  or  in  turning  the  optical  tube  from  the 
vertical  to  the  horizontal.  In  rotating  the  stage,  the  object  would 
turn  upon  the  optic  axis ;  in  moving  the  tube  into  various  degrees 
of  oblicpiity  from  0"  to  90",  the  object  would  rotate  upon  its  horizontal 
axis.  The  result  would  be  that,  with  a  thin  stage  and  a  hemi- 
spherical lens  in  immersion  contact  with  the  under  surface  of  the  slide, 
all  the  complicated  swinging  substagcs  ami  other  contrivances  now 
upon  the  table  might  be  swept  away,  and  every  angle  of  illumination 
c«)\ild  be  got  by  merely  inclining  tlie  bo<ly  of  the  Microscope  upon  its 
sustaining  arc.  There  wouhl  only  bo  needed  a  lamp  on  a  level  with 
the  object  with  a  condenser  at  its  focal  distance  standing  upon  the 
table  in  line  between  the  lamp  and  the  object. 

Dr.  Carpenter  said  that  another  improvement  had  also  occurred 
to  liini,  and  that  was  to  construct  tlie  fork  so  that  it  would  carry 
round  the  object  iu  the  axis  of  the  Microscope.      It  did  not  do  so  as 

4  c  2 


1088  PROCEEDINGS   OF   THE  SOCIETY. 

at  present  constructed,  but  might  easily  be  made  to  do  so,  and  thus  to 
answer  the  purpose  of  a  rotating  stage. 

Mr.  John  May  all,  jun.,  described  the  ToUes-Blackham  Micro- 
scope, exhibited  by  Mr.  Crisp  (see  p.  520),  and  described  and  exhibited 
Hyde's  Illuminator,  which  had  been  devised  to  produce  a  luminous 
field  similar  to  that  obtained  by  Mr.  Wenham's  reflex  illuminator. 

Mr.  Crisp  called  attention  to  several  new  applications  of  ebonite 
to  microscopical  purposes,  including  "  Botterill's  Life  Trough  "  (see 
p.  148),  now  made  in  ebonite,  Atwood's  rubber-cell  (see  p.  1041),  and 
Beck's  rotating  holder  for  the  latter. 


Mr.  Swift  exhibited  and  explained  by  means  of  a  diagram  a  form 
of  ("  calotte  ")  diaphragm  which  he  had  devised  for  bringing  a  series 
of  apertures  immediately  below  the  object  (see  p.  1053). 


Mr.  W.  G.  Lettsom  described  Professor  Abbe's  new  form  of 
binocular  eye-piece  ("  Stereoscopic  Ocular  ")  specially  adapted  for  the 
short-bodied  instruments  in  ordinary  use  on  the  Continent,  illus- 
trating it  by  a  diagram  drawn  upon  the  black  board,  and  by  the 
exhibition  of  the  instrument  in  the  room. 

Mr.  Crisp  exhibited  for  comparison  three  other  forms  of  binocular 
eye-pieces,  viz.  those  of  Prazmowski,  ToUes,  and  Verick. 

Dr.  Carpenter  said  he  should  like  to  say  a  few  words  about  the 
arrangement  of  Professor  Abbe.  He  had  paid  a  great  deal  of  atten- 
tion to  the  subject  of  binocular  vision,  and  might  say  that  he  had 
been  at  the  birth  of  the  binociilar  Microscope.  As  regarded  the  one 
now  exhibited,  it  seemed  to  him  to  have  been  overlooked  that  in  order 
to  get  a  true  stereoscopic  projection  the  rays  from  one  side  of  the 
objective  must  cross  completely  over  to  the  opposite  side  of  the 
instrument.  This  was  done  in  Nachet's  and  in  Wenham's,  and  with 
either  of  these  it  was  impossible  to  see  an  object  in  any  other  way 
than  stereoscopically.  To  produce  this  effect  it  was  necessary  that 
the  lateral  inversion  should  be  antagonized  by  the  reflecting  power  of 
the  prism — they  must  have  the  reflected  ray  crossing  the  other 
entirely,  otherwise  they  could  not  have  any  true  stereoscopic  efi'ect. 

Another  observation  which  he  had  to  make  was  that  the  arrange- 
ment now  described  resembled  Mr.  Wenham's  arrangement  for  a  non- 
stereoscopic  binocular.  In  this  form  Mr.  Wenham  made  his  two 
prisms  in  the  same  way,  and  except  that  they  were  in  contact  the 
thing  was  the  same  ;  it  was  devised  for  the  purpose  of  diminishing 
the  fatigue  of  working  with  one  eye  so  as  to  give  a  more  comfortable 
view  of  an  object  in  case  of  prolonged  observation,  and  this  was 
described  and  figured  in  the  '  Transactiotis '  of  the  Society  for  1866 
(N.  S.  xiv.  pp.  1U3-6,  3  figs.).  In  the  true  stereoscopic  binocular  the 
pencil  of  light  was  split  into  two  halves,  and  in  Mr.  Wenham's  standard 
form  one  lateral  half  went  into  the  principal  body  and  the  other  was 
reflected  obliquely  into  the  secondary  body.     But  this  new  form  did 


PROCEEDINGS   OF   THE   SOCIETY.  1089 

not  do  SO,  neither  did  that  of  Messrs.  Powell  and  Lealand — indeed  they 
did  not  pretend  that  it  did.  He  had,  therefore,  no  hesitation  in  saying 
that  any  stereoscopic  etfect  in  such  an  instrument  must  be  formed 
entirely  in  the  imagination  of  the  observer,  just  as  a  seal  might  be  seen 
under  certain  conditions,  and  might  be  imagined  to  be  either  a  sunk 
impression  or  a  raised  cameo ;  for  when  one  had  got  a  conception 
of  solidity,  this  mental  conception  might  easily  be  carried  on. 

He  had  found  the  binocular  to  be  essential  to  a  knowledge  of  solid 
form,  and  as  he  had  often  expressed  that  opinion,  a  number  of  foreign 
microscopists  had  from  time  to  time  come  to  him  upon  the  subject. 
One  day  Professor  Haeckol,  amongst  others,  seemed,  as  most  conti- 
nental observers  used  to  be,  rather  doubtful  as  to  the  value  of  the 
binocular.  He  showed  him  at  first  some  Polycistina,  which  were  of 
course  familiar  to  him  as  solid  objects,  and  he  looked  at  them  and 
said  he  did  not  see  them  ditferently  from  usual.  Then  he  showed 
him  an  object  which  he  had  not  seen  before — it  was  a  piece  of  the 
wing  of  a  small  moth,  which  had  a  peculiar  arrangement  of  the  scales. 
Drawing  out  the  prism,  he  asked  the  professor  to  look  at  the  object 
and  to  adjust  the  focus  so  as  to  get  a  good  middle  distance,  and  then 
whilst  he  was  looking  at  it  the  prism  was  suddenly  replaced.  He 
quite  started  at  the  result,  for  he  then  saw  the  undulations  as  if  they 
were  a  solid  raised  surface,  and  admitted  at  once  the  true  character  of 
the  stereoscopic  effect  produced.  The  mere  fact  that  altering  the 
caps  as  described  by  Mr.  Lettsom  was  stated  to  be  competent  to 
change  the  image  from  stereoscopic  to  pseudoscopic  satisfied  him  at 
once  that  there  was  no  true  stereoscopic  effect  produced. 


Mr.  Crisp  referred  to  several  communications  upon  the  subject 
of  wax  cells,  American  correspondents  more  particularly  bcin*'  of 
opinion  that  Professor  Hamilton  Smith  had  given  tliem  up  too  hastily, 
and  tliat  the  sweating  comi)hi,ined  of  came  from  the  use  of  cements 
containing  turpentine,  &c.,  and  other  causes  apart  from  the  wax  (see 
p.  1039). 

Mr.  Shadbolt's  Memorandum  on  Apertures  "exceeding  180°  in 
Air  "  was  read  as  follows  : — 

"  It  was  with  c(Jiisidcrable  regret  that  I  found  a  short  article  in  the 
October  nunibur  <»tthe  'Journal'  (i).875),  entitled  'Apertures  exceeding 
180  in  Air,'  especially  a.s  it  was  not  followed  by  any  editorial  com- 
ment of  warning  against  the  errors  of  both  theory  and  fact  involved 
therein. 

In  the  article  in  question  I  find  the  following  sentence,  viz. : — 
'  The  whole  confusion  has  arisen  from  not  getting  beyond  the  simplo 
and  obvious  fact,  about  wliich  there  can  bo  no  dispute,  that  a  </ry  lens 
cannot  have  an  aperture  of  more  than  18U\'  To  anyone  who  cannot 
grasp  this  'obvious  hut,'  1  doubt  th.it  any  explanation  of  optical  plie- 
noHKiia  would  bt!  inttdiigible.  The  sUitenient  is  true,  certainly  ;  but 
it  is  also  misleading,  because  it  is  only  a  part  of  the  truth.    The  whole 


1090  PROCEEDINGS    OF    THE    SOCIETY. 

confusion  has  arisen  from  not  getting  beyond  the  simple  and  obvious 
fact — aboiit  which  there  can  be  no  dispute,  that  no  lens,  dry  or  immer- 
sion, can  possibly  have  an  aperture  of  180°. 

I  presume  that  no  one  will  dispute  the  fact,  that  two  contiguous 
points  in  any  object  must  be  in  a  straight  line,  and  that  three  points 
contiguous  to  one  another  lie  in  a  plane,  consequently  that  if  the 
bundle  of  light-rays  radiant  from  each  point  reached  180° — one  of 
such  rays  at  least  must  pass  clean  through  the  adjacent  point ;  and  this 
is  equally  true,  whether  the  object  is  in  air,  or  immersed  in  water,  oil, 
balsam,  or  any  other  transparent  medium.  The  difference  is  infini- 
tesimal ;  but  less  than  180°  it  must  be.  Again,  I  presume  that  no  one 
will  contend  that  it  is  possible  to  collect  from  any  given  point  a 
larger  number  of  light-rays  than  are  actually  emitted  from  that  point, 
and  if  so,  my  contention  is  established. 

But  I  am  by  no  means  content  to  leave  the  matter  here.  A  lens 
must  have  a  surface  of  some  kind,  and  it  is  quite  impossible  to  bring 
the  surface  of  a  lens  in  close  contact  with  the  whole  of  even  so  small  a 
part  of  the  object  as  we  wish  to  examine  ;  and  unless  we  can  do  this — 
nay,  even  if  we  could  do  this — we  must  leave  out  a  further  portion  of 
the  supposed  pencil  of  180°  of  radiant  light ;  because,  as  the  extreme 
rays  would  be  paralell  to  the  front  surface  of  the  lens,  there  would  be 
no  refraction, 

I  may  add  further,  that  were  such  a  lens  constructed  that  it  could 
refract  the  largest  possible  portions  of  the  180°  of  radiant  light,  it 
would  be  practically  useless,  as  there  would  be  no  working  distance 
and  no  possible  adjustment  to  suit  varying  sights.  I  state  as  a  matter 
of  opinion  only,  that  I  very  much  doubt  whether  we  can  hope  to  see 
any  lens  constructed  to  include  practically,  that  is,  efficiently,  more 
than  170°  of  aperture.  Let  us  suppose  such  a  dry  lens  to  have  been 
constructed  and  placed  in  position  to  examine  some  transparent  object 
simply  laid  upon  a  slip  of  glass,  which  object  is  illuminated  from 
below  ;  the  lens  would  now  receive  and  refract  from  each  luminous 
point  a  pencil  of  170° ;  but  if  that  object  were  mounted  in  balsam,  or 
other  dense  medium,  and  protected  as  usual  with  a  thin  covering  of 
glass,  the  same  dry  objective  could  no  longer  refract  the  170°  radiant 
pencil  of  light,  because  certain  of  the  rays  of  that  pencil  would,  in 
their  passage  towards  the  lens,  fall  on  the  upper  surface  of  the  covering- 
glass,  at  and  beyond  the  critical  angle,  and  would  therefore  find  no 
exit ;  the  angular  aperture  of  each  pencil  of  rays  proceeding  from  the 
object,  would  therefore  be  limited  to  an  angle  equal  to  double  the 
critical  angle  for  the  covering-glass  employed,  I  may  remark,  in 
passing,  that  this  would  not  be  the  case  were  the  object  mounted  dry 
and  the  two  surfaces  of  the  covering-glass  parallel. 

It  now  becomes  apparent  why  an  immersion  objective  can  in  suit- 
able cases  perform  better  than  dry  ones.  With  an  appropriate  fluid 
interposed  the  critical  angle  for  glass  becomes  obliterated ;  and  the 
pencil  of  rays,  whatever  its  aperture,  can  pass  direct  to  the  posterior 
surface  of  the  front  lens,  and  there  become  refracted  for  effective  use 
in  forming  an  image ;  and  this  is  where  the  immersion  lens  has  the 
advantage  ;  it  can  include  as  large  a  portion  of  the  radiant  pencils  of 


PROCEEDINGS   OF   THE   SOCIETY.  1091 

light  as  the  lens  is  constracted  to  admit,  irrespective  of  the  mounting 
of  the  object,  but  in  no  case  can  it  reach,  far  less  exceed,  180^. 

It  may  be  as  well  here  to  note,  that  with  a  dry  lens,  both  the  front 
and  back  surfaces  of  the  front  lens  take  part  in  the  refractions  ;  but 
with  an  immersion  lens,  the  refraction  at  the  front  surface  is  sup- 
pressed or  greatly  reduced. 

Before  concluding,  I  wish  to  make  a  remark  or  two  upon  some  of 
the  statements  in  the  article,  and  as  it  is  anonymous,  I  trust  I  can  do 
so  without  offence  ;  my  sole  object  being  to  resist  the  promulgation  of 
erroneous  views,  and  the  use  of  vague  and  incorrect  expressions  in 
matters  of  scientific  interest.  What  does  the  writer  of  the  article 
mean  by  '  radiant  spaces  ?  '  How  can  '  diffraction  spectra '  pass 
through  them  ?  How  can  a  '  space  of  6°  '  become  larger  or  smaller  ? 
It  is  to  such  expressions  as  these  that  confusion  of  ideas  arises,  far 
more  than  from  any  inability  to  gi-asp  the  fact  that  a  lens  cannot  have 
an  aperture  of  more  than  180^." 

Mr.  Wilson  said  that  Mr.  Shadbolt  appeared  to  have  altogether 
misapprehended  the  note  at  p.  875.  That  did  not  refer  to  "  angle  " 
at  all,  but  to  "  aperture,"  and  it  was  now  well  established  that  they 
were  not  synonymous  terms  ;  he  did  not  therefore  follow  Mr.  Shadbolt's 
demonstration  as  to  the  angle  being  necessarily  less  than  180^,  which 
he  imagined  that  no  one  disputed.  The  original  note  and  Mr.  Shad- 
bolt's  letter  related  in  fact  to  two  distinct  matters. 

Mr.  Crisp  said  the  note  referred  to  would  certainly  not  have  been 
admitted  into  the  '  Journal '  if  it  had  been  inconsistent  with  Mr.  Shad- 
bolt's  demonstration  as  to  an  angle  of  180^  On  receipt  of  his  letter, 
he  had  written  to  Mr.  Shadbolt,  pointing  out  that  the  note  referred  to 
aperture,  and  had  received  a  further  letter,  in  which  he  said  : — 

"  I  cannot  assent  to  the  word  '  aperture '  as  employed.  The  abso- 
lute '  aperture '  of  a  telescopic  lens  is  sufficiently  intelligible,  so  is 
the  '  angular  aperture  '  of  a  microscopical  lens,  but  an  '  apertui-e '  that 
is  neither  absolute  nor  angular  is  not  intelligible  at  all,  esj^ecially  if 
you  call  it  '  numerical  aperture.'  Now,  if  it  had  been  called '  nuyncrical 
resolving poicer,'  it  would  I  fancy  be  nearer  to  what  is  really  meant. 

I  am  fully  alive  to  the  advantage  of  immersion  lenses  in  appro- 
priate  conditions,  but  I  altogether  deny  their  universal  apjdicability. 
There  is  no  difficulty  in  getting  the  largest  practicable  pencil  of  light, 
say  170^",  into  a  dry  lens;  the  difficulty  is,  that  you  cannot  get  such  a 
pencil  out  of  the  mounting  of  the  object  when  iu  balsam,  or  similar 
medium,  and  that  is  bounded  by  a  stratum  of  air. 

Tliis  is  very  easily  demonstrable  by  a  few  lines  added  to  the  diagram 
given  by  Professor  Stijkes,  at  p.  lil,  V(d.  i.  of  the  present  scries. 
Witli  a  little,  modification  this  observation  apj)lies  also  to  an  object 
mounted  dry,  but  covered  with  a  thin  film  of  glass. 

Sliould  there  be  any  kind  of  discussion,  kindly  put  forward  these 
remarks  in  my  absence." 

Mr.  Wilson  said  that  Professor  Stokes'  paper  was  a  refutation  of 
tho  very  fallacy  on  which  Mr.  Shadbidt's  reasoning  was  based.  Tho 
expression  "  angle  of  apijrturo  "  had  never  in  fact  been  a  measure  of 
the  relative  apertures  of  even  dry  objectives,  and  on  tho  introduction  of 


1092  PROCEEDINGS   OF    THE   SOCIETY. 

immersion  objectives  it  had  ceased  to  have  any  definite  meaning  what- 
ever. ^ 

Dr.  Maddox  exhibited  and  described  a  modification  of  his  Aeroconi- 
scope  for  collecting  particles  from  the  atmosphere. 


Mr.  Crisp  explained  the  properties  of  monobromide  of  naphthaline 
proposed  by  Professor  Abbe  for  mountiug  diatoms.  Its  refractive 
index  was  stated  as  1'658,  and  its  "index  of  visibility"  (on  Mr. 
Stephenson's  theory)  as  double  that  of  Canada  balsam,  or  22  when 
used  on  diatomaceous  silex  (see  p.  1043). 

Dr.  Edmunds  inquired  if  it  was  unchangeable. 

Mr.  Crisp  said  it  did  not  seem  to  have  been  very  long  in  use.  It 
could  be  obtained  in  London. 


Dr.  G.  W.  Royston-Pigott's  paper  "  On  a  new  Method  of  Testing 
an  Object-glass,  used  as  a  simultaneous  Condensing  Illuminator  of 
brilliantly  reflecting  objects,  such  as  minute  particles  of  Quicksilver  " 
(see  p.  916),  was,  owing  to  the  lateness  of  the  hour,  taken  as  read. 


Mr.  Stewart's  paper,  "  On  some  Structural  Features  of  Echino- 
strephus  molare,  Parasalenia  gratiosa,  and  Stomopneustes  variolaris" 
(see  p.  909),  was  also  taken  as  read. 


The  following  Objects,  Apparatus,  &c.,  were  exhibited:— 

Mr.  O.  Brandt : — Photographs  of  Pleurosigma  angulatum  and  Frus- 
tulia  saxonica. 

Dr.  Carpenter  : — Wale's  Working  Microscope  and  Iris  Diaphragm. 

Mr.  Coppock : — Eotating  Holders  for  At  wood's  Eubber  Cells. 

Mr.  Crisp: — The  nine  Microscopes  mentioned  on  p.  1086;  and 
Botterill's  Life  Trough  in  Ebonite. 

Mr.  H.  G.  Hanks : — Santa  Monica  Earth,  and  Section  and  Photo- 
graphs of  the  San  Bernardino  Meteorite. 

Mr.  Lettsom : — Abbe's  Binocular  Eye-piece. 

Prof.  A.  Liversidge  : — "  Tripoli "  from  Kichmond  Kiver,  N.  S.  W. 

Mr.  J.  Mayall,  junr. : — Hyde's  Illuminator. 

Dr.  Maddox : — Modified  Aeroconiscope. 

Messrs.  Powell  and  Lealand: — Amphipleura  pellucida  with  ^^ 
homogeneous-immersion  objective,  and  their  modification  of  the 
vertical  illuminator. 

Mr.  Stewart : — Various  Echinoderms  illustrating  his  paper. 

Mr.  Swift : — Microscope  with  "  Calotte  "  Diaphragm. 


New  Fellows. — The  following  were  elected  Ordinary  Fellows  : — 
Sir  Henry  Cotterell,  Bart.,  and  Messrs.  F.  M.  Balfour,  M.A.,  F.R.S., 
John  Henry  Cooke,  and  Levison  Edward  Scarph,  M.A. 

Walter  W.  Eeeves, 
Assist.-Secretary. 


(     9     ) 


NOTICE  OF  REMOVAL 

68,  CORNHILL, 
London,  E.G.,  June  24th,  1880. 

R.  &  J.  BECK, 

MANUFACTURING  OPTICIANS, 

Beg  respectfully  to  inform  their  friends  that 
they  have  REMOVED  from 

31  TO  68,  CORNHILL 


New  Enlarged  Edition 


OF 


ILLUSTlfATED  CATALOGUE 


UK 


MICEOSCOPES,  APPAEATUS,  &c., 

Forwarded  Post  Free  upon  application. 


(     10    ) 
I.   Conversion  of  British  and  Metric  Measures. 


?cftle  of  Inche?, 
C'Cnti  metres, 


cm.  'i 

mm.    Ins.       '  [ 


Lj3t_i 


TSocnr 

1 

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1 

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1000  fx     =1  mm.  I 
10  mm.=l  cm.     I 

10  cm.  =1  dm. 

I 
10  dm.  =1  metre., 


Inches,  <f-c.,  into 

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ins.      ^ 

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6-349943 

7-937429 

9-524914 

11-112400 

12-699886 

14-287372 

15-874857 

17-462343 

19-049829 

20-637315 

22-224800 

23-81-2286 

25-399772 

50-799544 

76-199316 

101-599088 

126-998860 

152-398632 

177-798104 

203-198176 

228-597948 

253-997720 

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mptros. 

=   -304797 
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(1.)  Lineal. 
MicromilUmetres^  Millimetres,  4'C.,  into  Inches,  4'C. 


M 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 

11 
12 
13 
14 
15 
16 
17 
18 
19 
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21 
22 
23 
24 
25 
23 
27 
28 
29 
30 

31 
32 
33 
34 
35 
36 
37 
38 
39 
40 

41 
42 
43 
44 
45 
46 
47 
48 
49 
50 

60 

70 

80 

90 

100 

200 

300 

400 

500 

600 

700 

800 

900 

1000  ( 


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001535 
001575 


1 
2 
3 

4 
5 
6 

7 
8 
9 
10  (1  cm.) 

11 
12 
13 
14 
15 
16 
17 
18 
19 
20  (2  cm.) 

21 
22 
23 

24 
25 
26 

27  1 

28  1 

29  1 

30  (3  cm.)  1 


001614 
001654 
001693 
001732 
001772 
001811 
001850 
001890 
001929 
001969 

002302 
002756 
003150 
003543 
008137 
007874 
011811 
(015748 
0]9685 
023022 
027559 
031496 
035433 
Imm.) 


31 
32 
33 
34 
35 
33 
.37 
38 
39 

40  (4  cm.)  1 

41  1 
1 


42 

43  1 

44  1 

45  1 

46  1 

47  1 

48  1 

49  1 

50  (5  cm.)  1 


Ins.   1 

039370 
078741 
118111 
157482 
190852 
236223 
275593 
314963 
354334 
393704 

433075 
472445 
511816 
551186 
590556 
629927 
669297 
708668 
748038 
787409 

826779 
866149 
905520 
944890 
984261 
023631 
063002 
102372 
141742 
181113 

220483 
259854 
299224 
338595 
377965 
417335 
456706 
496076 
535447 
574817 

614188 
653558 
692928 
732299 
771669 
811040 
850410 
889781 
929151 
968521 


declm. 
1 
2 
3 
4 
5 
6 
7 
8 
9 


61 
62 

53 
54 
55 
56 
57 
58 
59 
60  (6  cm.) 

61 
62 
63 
64 
65 
66 
67 
68 
69 
70  (7  cm.) 

71 
72 
73 
74 
75 
76 
77 
78 
79 
80  (8  cm.) 

81 
82 
83 
84 
85 
86 
87 
88 
89 
90  (9  cm.) 

91 
92 
93 
94 
95 
96 
97 
98 
99 
100  (10  cm. 


10  (1  metre)  39 
=  3 
=  1 


Ins. 

-937043 
•874086 
•S11129 
-748172 
•685215 
-622258 
-559301 
•496344 
-433387 
-370430 
-280869  ft. 
-093623  yds. 


(  11  ) 


II.    Corresponding    De-   jj 

III.  Coi 

iversi 

an  0 

f  Numeri 

cal  and  i 

Angular 

grees  in 

the  Fahren- 

Aperture 

heit  and 

Centigrade 

Scales. 

Angle  of  Aperture 

of 

Theoretical 

Resolving 

Tower,  in 

Lines  to  an  Inch. 

Fahr. 

0 

Cent. 
o 

Cent.     Fabr. 
o            o 

Numerical 
Apertiure. 

Dry 

Water- 
Immersion 

JIOTtwgeneous 
Jmvwrsion 

500 

260-0 

100   212-0 

UQj'-CElvco.     1 

Objectives. 

Objectives. 

(A=0-5269/i, 

450 

232-2 
204-4 

98   208-4    i 
96   204-8    I 

K'*  — 

(n  =  l-33.) 

1 

(?»=  1-62.) 

=line  E.) 

400 

350 

176 -7 

94   201-2    i 

1-52 

180°      0' 

146,528 

300 

148-9 

92   197-6    1 

1-50 

161°  23' 

144,600 

250 

121-1 

90   194  0 

1-48 

.. 

153°  39' 

142,672 

212 

100-0 

88   190-4    , 

1-46 

147°  42' 

140,744 

210 

98-9 

86   186-8    i 

1-44 

142°  40' 

138.816 

205 

961 

84   183-2 

1-42 

138°  12' 

136,888 

200 

93-3 

82   179-0    ' 

1-40 

134°  10' 

134,960 

195 

90-6 

80   1760 

1-38 

.. 

,. 

130°  26' 

133,032 

190 

87-8 

78   172-4    1 

1-36 

126°  57' 

131,104 

185 

85-0 

76   168-8    1 

1-34 

„ 

123°  40' 

129,176 

180 

82-2 

74  105-2    ' 

1-33 

180°'    C 

122°     6' 

128,212 

175 

79-4 

72   161-6    i 

1-32 

165°  56' 

120°  33' 

127,248 

170 

7(3-7 

70   158-0    j 

1-30 

., 

155°  38' 

117°  34' 

125.320 

165 

73-9 

68   154-4 

1-28 

.. 

148°  28' 

114°  44' 

123,392 

160 

71-1 

66   150-8 

1-26 

142°  39' 

111°  59' 

121,464 

155 

68-3 

64  147-2 

1-24 

137°  36' 

109°  20' 

119.536 

150 

65-6 

62   143-6 

1-22 

133°    4' 

106°  45' 

117,608 

145 

62-8 

60   UO-0 

1-20 

128°  55' 

104°  15' 

115,680 

140 

60-0 

58   130-4 

1-18 

.. 

125°    3' 

101°  50' 

113.752 

135 

57-2 

56   132-8 

1-16 

121°  26' 

99°  29' 

111,824 

130 

54-4 

54   129-2 

1-14 

118°  00' 

97°  11' 

109,893 

125 

51-7 

52   125-6 

1-12 

114°  44' 

94°  56' 

107,968 

120 

48-9 

50   122  0 

110 

111°  36' 

92°  43' 

106,040 

115 

46-1 

48   118-4    1 

1-08 

^ , 

108°  36' 

90°  33' 

104.112 

110 

43-3 

46   114-8    i 

106 

,, 

105°  42' 

88°  26' 

102.184 

105 

40-6 

44   111-2 

1-04 

., 

102°  53' 

86°  21' 

100,256 

100 

37-8 

42   107-0 

1-02 

,  , 

100°  10' 

84°  18' 

98,328 

95 

35-0 

40   104-0 

1-0 

ISO^' 

0' 

97°  31' 

82°  17' 

96,400 

90 

32-2 

38   100-4 

0-98 

157° 

2' 

94°  56' 

80°  17' 

94,472 

85 

29-4 

36     96-8 

0-96 

147° 

29' 

92°  24' 

78°  20' 

92,544 

80 

26-7 

34     93-2 

0-94 

140° 

6' 

89°  56' 

76°  24' 

90.616 

75 

239 

32     89-6 

0-02 

133° 

51' 

87°  32' 

74°  30' 

88,688 

70 

21-1 

30     86-0 

0-90 

128° 

19' 

85°  10' 

72°  36' 

86.760 

65 

IS -3 

28     82-4 

0-88 

123° 

17' 

8-2°  51' 

70°  44' 

84,832 

60 

15-6 

26     78-8 

0-86 

118° 

38' 

hO°  34' 

68°  54' 

82,904 

65 

12-8 

24     75-2 

0-84 

114° 

17' 

78°  20' 

67°    6' 

80,976 

50 

10  0 

22     71-0 

!         0-82 

110° 

10' 

76°    8' 

65°  18' 

79,018 

45 

7-2 

20     680 

i         0-80 

106° 

16' 

73°  58' 

63°  31' 

77,120 

40 

4-4 

18     61-4 

0-78 

10-2° 

31' 

71°  49' 

61°  45' 

75,192 

36 

1-7 

18     60-8 

0-78 

9S° 

56' 

69°  42' 

00°    0' 

73,264 

32 

0-0 

14     57-2  i 

0  74 

95" 

28' 

67°  36' 

58°  10' 

71,336 

30 

-   11 

12     53-6 

0-72 

92° 

6' 

65°  32' 

56°  32' 

69,408 

26 

-  39 

10     50  0 

i         0-70 
0-68 
0-08 

88° 

51' 

63°  31' 

54°  50' 

67,480 

20 

-  6-7 

8     46-4 

85° 

41' 

61°  30' 

53°    9' 

65,5.52 

15 

-  9-4 

6     42-8 

^r 

30' 

59°  30' 

51°  28' 

03,(;24 

10 

-12-2 

4     3:»-2 

0-64 
0-62 

79° 

35' 

57°  31' 

49°  48' 

61.096 

5 

-15-0 

2     35-6 

70° 

38' 

55°  34' 

48°    9' 

.')H,768 

0 

-17-8 

0     32  0 

0-60 

73-^ 

44' 

53°  3!^ 

46'^  30' 

57,S40 

-     5 

-20-6 

-      2     28-4 

0-68 

70° 

54' 

51°  42' 

44°  61' 

65.912 

-  10 

-23-3 

—     4     21-8 

0-66 

6S° 

6' 

49°  48' 

43°  14' 

53,984 

-  15 

-2(;-l 

-     6     21-2 

0-54 

'65° 

22' 

47°  54' 

41°  37' 

52,056 

-20 

-28-9 

-     8      17-6 

0  62 

6-Z° 

40' 

46°    2' 

40°    0' 

50, 1-28 

-  25 

-31-7 

-  10      140 

0-60 

60° 

0' 

44°  10' 

3S°  24' 

4S,200 

-30 

-34-4 

-   12     10-4 

0-48 

\^r 

22' 

42"  18' 

36°  49' 

46.272 

-  35 

-37-2 

1  -   14       6-8 

0-46 

i>'4° 

46' 

40"  28' 

35°  14' 

45,344 

-40 

-40- 0 

-  10       H-2 

r.44 

52° 

12' 

38°  38' 

.13°  39' 

42.416 

-  45 

-42-8 

1  -   10  -  0-4 

42 

49° 

40' 

86°  49' 

32''    5' 

40.48S 

-50 

-450 

-  20  -  4-0 

.-40 

47° 

9' 

35°    0' 

80°  81' 

88,560 

(     12    ) 

Microscopes. 


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(  13  ) 

MICROSCOPES     AND     BALANCES 


AS   MADE   BT 


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The  £11  11«.  Instrument  consists  of  1-inch  and  J-inch  Object-glasses,  with  Apertures 
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(     14    ) 

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(  15  ): 

Council  Medal  and  Highest  Award,  Great  Exhibition,  London,  1851. 

Gold  Medal,  Paris  Exposition,  1867. 

Medal  and  Highest  Award,  Exhibition,  London,  1862. 

Medal  and  Diploma,  Centennial  Exhibition,  Philadelphia,  1876. 

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Gold  Medal  and  Diploma,  Paris  Exposition,  1878. 


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THE 

ROYAL  MICROSCOPICAL  SOCIETY. 

(Founded  in  1839.    Incorporated  by  Eoyal  Charter  in  1866.) 


The  Society  was  established  for  the  communication  and  discussion 
of  observations  and  discoveries  (1)  tending  to  improvements  in  the  con- 
struction and  mode  of  application  of  the  Microscope,  or  (2)  relating  to 
Biological  or  other  subjects  of  Microscopical  Research. 

It  consists  of  Ordinary,  Honorary,  and  Ex-officio  Fellows. 

Ordinary  Fellows  are  elected  on  a  Certificate  of  Recommendation 
signed  by  three  Fellows,  stating  the  names,  residence,  description,  &c.,  of 
the  Candidate,  of  whom  one  of  the  proposers  must  have  personal  know- 
ledge. The  Certificate  is  read  at  a  Monthly  Meeting,  and  the  Candidate 
balloted  for  at  the  succeeding  Meeting. 

The  Annual  Subscription  is  2Z.  2«.,  payable  in  advance  on  election, 
and  subsequently  on  1st  January  annually,  with  an  Entrance  Fee  of  21,  2s. 
Future  payments  of  the  former  may  be  compounded  for  at  any  time  for 
31Z.  10s.  Fellows  elected  at  a  meeting  subsequent  to  that  in  June  are 
only  called  upon  for  one-half  of  the  year's  subscription,  and  Fellows 
absent  from  the  United  Kingdom  for  a  year,  or  permanently  residing 
abroad,  are  exempt  from  one-half  the  subscription  during  absence. 

Honorary  Fellows  (limited  to  50),  consisting  of  persons  eminent 
in  Biological  or  Microscopical  Science,  are  elected  on  the  recommendation 
of  three  Fellows  and  the  approval  of  the  Council. 

Ex-oflB.eio  Fellows  (limited  to  100)  consist  of  the  Presidents  for 
the  time  being  of  such  Societies  at  home  and  abroad  as  the  Council  may 
recommend  and  a  Monthly  Meeting  approve.  They  are  entitled  to  receive 
the  Society's  Publications,  and  to  exercise  all  other  privileges  of  Fellows, 
except  voting,  but  are  not  required  to  pay  any  Entrance  Fee  or  Annual 
Subscription. 

The  Council,  by  whom  the  afiairs  of  the  Society  are  managed,  is 
elected  annually,  and  is  composed  of  the  President,  four  Vice-Presidents, 
Treasurer,  two  Secretaries,  and  twelve  other  Fellows. 

The  Meetings  are  held  on  the  second  Wednesday  in  each  month, 
from  October  to  June,  in  the  Society's  Library  at  King's  College,  Strand, 
W.C.  (commencing  at  8  p.m.).  Visitors  are  admitted  by  the  introduction  of 
Fellows. 

In  each  Session  two  additional  evenings  ("Scientific  Evenings")  are 
devoted  to  the  exhibition  of  Apparatus  and  Objects  of  novelty  or  interest 
relating  to  the  Microscope  or  the  subjects  of  Microscopical  Research. 

The  Journal,  containing  the  Transactions  and  Proceedings  of  the 
Society,  with  a  Record  of  Current  Researches  relating  to  Invertebrata, 
Cryptogamia,  Microscopy,  &c.,  is  published  bi-monthly,  and  is  forwarded 
gratis  to  all  Ordinary  and  Ex-ojBficio  Fellows  residing  in  countries  within 
the  Postal  Union. 

The  Library,  with  the  Instruments,  Apparatus,  and  Cabinet  of 
Objects,  is  open  for  the  use  of  Fellows  on  Mondays,  Tuesdays,  Thursdays, 
and  Fridays,  from  11  a.m.  to  4  p.m.,  and  on  Wednesdays  from  7  to  10  p.m. 
It  is  closed  during  August. 

Forms  of  proposal  for  Fellowship,  and  any  further  information,  may  he  obtained  by 
application  to  the  Secretaries,  or  Assistant-Secretary,  at  the  Library  of  the  Society,  King's 
College,  Strand,  W.C. 


New  York   Botanical   Garden   Librar 


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