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TRANSLATIONS 


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FOREIGN BIOLOGICAL MEMOIRS 


IT 


London 
HENRY FROWDE 


OXFORD UNIVERSITY PRESS WAREHOUSE 


AMEN CORNER, E.C. 


ills Os 
ANATOMY OF THE FROG 


BY 


Dr. ALEXANDER ECKER 


PROFESSOR OF HUMAN AND COMPARATIVE ANATOMY 
IN THE UNIVERSITY OF FREIBURG 


Translated, with numerous Annotations and Additions 


BY 


GEORGE HASLAM, M.D. 


SCIENTIFIC ASSISTANT IN THE MEDICAL DEPARTMENT IN THE UNIVERSITY 
OF ZURICH ; FORMERLY ASSISTANT LECTURER IN PHYSIOLOGY IN THI: 
OWENS COLLEGE, VICTORIA UNIVERSITY, MANCHESTER 


ILLUSTRATED WITH MANY WOOD ENGRAVINGS 


AND TWO COLOURED PLATES EXECUTED BY HOFMANN, WURTZBURG, BAVARIA 


Orford 
AT THE CLARENDON PRESS 
1889 


[All rights reserved] 


OWA AL 

Les VIN 
ited th 

a C60, CU 


OUT AND AE 


ae 


FEB 18 1896 


TRANSLATOR’S PREFACE. 


I unprertook the publication of a translation of Ecker’s 
‘Anatomie des Frosches’ at the suggestion of Professor A. 
Gamgee while I was working under his superintendence in the 
physiological laboratory of the Owens College. The work was 
subsequently accepted by the Delegates of the Clarendon Press, as 
one of the series of ‘Foreign Biological Memoirs,’ published by them. 
Early in the progress of the work it became evident that a mere 
translation would be unsatisfactory, and that it would be desirable 
to recast and modify several portions of the book. It was deemed 
advisable to give greater completeness to the work by descriptions 
of the minute structure of the several organs. For these purposes 
the appearance of the work has been unavoidably delayed. 

I have done my best to bring the book up to date by including 
the results of recent researches, to which I have added many facts 
derived from my own personal investigations. All such additions 
are enclosed within square brackets [ |. More than a hundred 
new figures, of which one-third are original, have been added ; and 
copious, though it is feared still incomplete, lists of references to 
frog-literature have been drawn up. By these additions the size 
of the book has been considerably increased. 

In the several sections into which the book is divided the following 
points may be more particularly noticed :— 

Sect. I. The Bones and ‘Joints. The nomenclature of Parker 

and Bettany has been adopted throughout. 

Sect. IT. The Muscles. This section remains in its original form. 

Sect. III. The Nervous System. The chapters on the central 


20 5 


vi TRANSLATORS PREFACE. 


nervous system and the sympathetic system have been re- 
written. The description of the arteries of the brain is 
entirely new, while the chapters on cranial and spinal nerves 
have received many smaller additions, and have been re- 
arranged to facilitate reference. 

Sect. IV. The Vascular System. The chapter on the heart is 

- practically new, and many additions and alterations have 
been made in the descriptions of the blood-vessels and 
lymphaties. 

Sect. V. The Alimentary Canal, with its appendages, the Spleen 
and the Peritoneum. In this section much new material has 
been added : the descriptions of the blood-vessels of the liver, 
the ducts of the liver and pancreas, ete., being the results of 
original investigation. 

Sect. VI. The Respiratory Organs, the Thymus and Thyroid 
Glands. These organs have been carefully studied and 
numerous new details are noted. The lymphatic glands of 
the hyoid region have, after some hesitation, been designated 
tonsils. | 

Sect. VIT The Urino-Genital Organs. A very large number 
of preparations have been made to investigate the vessels and 
uriniferous tubes of the kidneys; and the descriptions of 
the remaining organs of this section have received large 
additions from recent publications. 

Sect. VIIT. The Skin and the Sense-Organs. This section has, 
with the exception of very small portions, been re-written and 
very much enlarged. 

Before concluding this preface, I must thank my friend Professor 
A. Milnes Marshall, of the Owens College, for all the help and 
kindness he has extended to me before and during the time this 
work has been in hand; to him I am indebted not alone for the 
loan of books, pamphlets, ete., and for much useful information, 
but also for the care and patience with which he has read and 
corrected the whole of the proof-sheets. 

To Professor G. Lunge, of Ziirich, I am indebted for the use of 
the library of the Gesellschaft der Naturforscher of Zürich; and 


TRANSLATOR S PREFACE. vil 


to my friend Mr. C. Herbert Hurst, of the Owens College, for the 
drawings for figures 132, 133, 134, and 136; also to Dr. Max 
Kôppen, of Strasburg, for the proof-sheets of his valuable paper, 
‘Zur Anatomie des Froschgehirns’: to these gentlemen I beg to 
express herewith my heartiest thanks. Lastly, I must express my 
sense of indebtedness to the Delegates of the Clarendon Press, who 
have kindly allowed me to alter the original plan of the book, and 
to make extensive additions far beyond the limits originally 
intended. 

A second edition of the original German work is in course of 
publication. The first part, on the bones and muscles, has already 
appeared. 


GEO. HASLAM. 


ZÜRICH, 1888. 


PREFACE TO. THE FIRST PART. 


Tue idea of this manual on the anatomy of the frog, of which I 
now offer the first part to physiologists and to those who would 
become such, occurred to me during the preparation of the plates 
for my ‘Icones Physiologicae” I was then convinced of the 
necessity of such a book. I regret that many direct and indirect 
causes have hindered its earlier completion ; fortunately, however, 
its appearance is still opportune, as the need for the book has not 
diminished. I am conscious that the book requires a recommenda- 
tion to the indulgent judgment of my fellow-workers, since almost 
every one has studied the frog for one purpose or another, and 
each will closely criticize in that department with which he is most 
familiar, Although I shall not be able to satisfy all, still I hope 
that my work may serve as a useful basis for further investigations, 
and I would apply to it the words with which Sémmering prefaced 
his anatomy: ‘Ich wünschte ein Handbuch zu liefern und seine 
Einrichtung so zu treffen, dass man künftig an ihm als emer Basis 
nach Erforderniss leicht ändern, wegnehmen und zusetzen künnte 1? 

Lest more be anticipated from the book than it is intended to 
supply, I would observe that I have throughout had in mind only 
a descriptive anatomy of the indigenous (German) frog ; a com- 
parative anatomy of Batrachians was as foreign to my intention as 
were developmental or histological questions : hence morphological 
details must not be expected. Any hope of formulating a systematic 
nomenclature of the muscles has been abandoned; as neither one 
based upon their mode of action, of which we know so little, nor 
one based upon their origins and insertions, as demonstrated by 
the unpronounceable names of Chaussier and Dugés, is really 
practicable. I have therefore preferred to avail myself, as far as 
possible, of the received names, which have been chosen partly 


1 «J wished to furnish a manual so arranged that it might serve as a basis easily 
altered, pruned, or enlarged as the fature might need.’ 


PREFACE TO THE FIRST PART. ix 
according to mode of action, partly according to origin and 
insertion, and partly according to position and form ; while in the 
choice of new names I have given preference to the simplest. 

The figures are, with few exceptions, original, and drawn by 
myself. Their careful execution in woodcut has added a very 


necessary neatness to that correctness, which alone I claim as mine. 


ALEXANDER ECKER. 


FREIBURG, 
February, 1864. 


PREFACE TO THE SECOND PART. 


SIXTEEN years have elapsed since the first portion of this 
anatomy of the frog appeared; this second portion, therefore, 
requires a somewhat apologetic introduction. 

The nervous and vascular systems have, in substance, been 
known for some years; still, certain points required a thorough 
revision : this seemed especially necessary with regard to the cranial 
nerves. In consequence of my anthropological investigations, and 
particularly through undertaking the editorship of the ‘Archiv fur 
Anthropologie, my attention was drawn into another channel, and 
I found it impossible to work out this chapter: consequently the 
whole was deferred, and would have been still longer delayed had I 
not received assistance. 

At my request Professor Wiedersheim undertook to investigate 
afresh the cranial nerves, the brain, the spinal cord, and the sympa- 
thetic system ; and the descriptions of these parts are the result of 
his work alone. I regard it as most advantageous to this second 
part that so experienced an investigator in the anatomy of Amphibia 
should have given me his help. 

The remaining portions appear almost unaltered as written 
several years ago; and the majority of the illustrations date from 


x PREFACE TO THE SECOND PART. 


the same period. I had neither the time nor the zeal necessary to 
re-examine the whole; besides, it is doubtful whether eyes some 
twenty years older would improve matters. 

This somewhat neglected book is therefore commended to the in- 
dulgence of my fellow-workers, with the hope that it may at least 
form a basis upon which further work may easily be done ; to proffer 
more than this, as I stated, with a quotation from Sémmering, 
in the preface to the first part, I have never even hoped. 

The final part of the work, on the viscera and sense-organs, has 
been undertaken by Professor Wiedersheim, and will appear in the 
Spring of 1882. 

ALEXANDER ECKER. 

FREIBURG, 

August, 1881. 


CONTENTS. 


— — 


PAGE 
INTRODUCTION. 4 A : : . : : . I 
SECTION J. THE BONES AND JOINTS . : : : ; 1 wh 
- II. THE Mouscies : é ai. : : : RENE 
5 III. THe Nervous System : > : : : AT 
, IV. THE VASCULAR SYSTEM . ; : - : 05207 
FA V. THE ALIMENTARY TRACT WITH ITS APPENDAGES, THE SPLEEN, AND 
THE PERITONEUM : = : - : 207 
5 VI. THE Larynx, Lunes, VocaL Sacs, THYMUS AND THYROID GLANDS, 
AND THE LYMPHATIC GLANDS (TONSILS?) OF THE Hyorn 
REGION . c : : - - 2 0507 
» VII. THE URINO-GENITAL SYSTEM, THE ADRENALS, AND THE Far- 
BoDIES . : - € : à : 225 
» VIII. THE SKIN AND THE SENSE-ORGANS : : - > ol 
ADDENDA, ETC. . : ; : : : . : = 425 


INDEX : : é : - : : : 4 AT 


ILLUSTRATIONS. 


FIGURE PAGE 
1. The Green water-frog, Rana es- 
culenta, L. 
2. The Brownegrass- frog, Rana tem- 
poraria, De - 
8. Femur of Rana esculenta . = 16 
4, Vertebrae of do. : : 17 
5. Vertebral column of do. . =p alte: 
6, 7. Section through a vertebra of 
Rana esculenta . - . 20 


8, 9. Urostyle of Rana esculenta. 21 
10-14. Skull of do. 5 BEA We ly Zhe: 
15. Nasal Cartilages of frog . 2 29 
16,17. Skull of Rana esculenta 29, 30 
18. Origin of suspensory cartilage 

from the skull Oey: 
19, 20. Skull of Rana esculenta 32, 33 
21. Mandible of Rana esculenta . 34 
22. Hyoid of Rana esculenta LEE 
23. Omosternum of Rana esculenta 36 
24. Shoulder-girdle and sternum of 


done we 30 
25. Shoulder-girdle of the frog 7 
26,27. Suprascapula of Rana es- 

culenta : 38 


28. Left scapula of Rana esculenta 38 
29. Scapula seen from behind = Be) 


30. Left coracoid . - - 39 
31. Clavicle of the left side . 230 
82. Right shoulder-girdle of Rana 
esculenta . 40 
33. Hinder border of the scapula 
and coracoid . 40 
34. Clavicular cartilage of ‘Rana 
esculenta . 3 40 
35. Humerus of Rana esculenta 
(female) . : é = Al 
36. Do. (male) . ‘ : Brack 
37. Do. (female) . : 41 


38. Radio-ulnar of Rana esculenta 43 
39, 40. Bones of the forearm and 

hand of Rana esculenta 44, 46 
41, 42. Pelvis of Rana esculenta . 48 
43. Horizontal section through the 


iliac bones, etc. . . 49 
44. Femur of Rana esculenta . 49 
45. Tibio-fibula of do. . é =» 50 
46. Section of the tibio-fibula - 50 


47. Right foot of Rana esculenta . 51 

48-50. Eye-muscles of do. 55, 56 

51. Skull and orbital cavities of 
Rana esculenta . : SS 


FIGURE 


52. M. levator bulbi of Rana es- 


culenta 57 
53. Eye-muscles of Rana esculenta 58 
54. Facial muscles of do. 59 
55. Muscles of the back and shoul- 

der . 60 
56, 57. Muscles of the lower j jaw of 

Rana esculenta . 5 (iso 
58. Muscles of the throat, chest, 

and abdomen of do. . 63 
59. Museles of the hyoid bone and 

the tongue of do. : 64 
60. Do. (from ‘below) 65 
61. Do. (from right side) 66 
62. Muscles of the throat, chest, 

and belly of Rana esculenta, 68 
63. Muscles of trunk of Rana es- 

culenta (from the right side) 69 
64. Second layer of abdominal mus- 

cles of Rana esculenta, from 

right side and below 70 
65. M. obliquus internus . 71 
66. Muscles of the back and shoul- 

der blade . 72 
67. Muscles of the back ‘and pelvic 

girdle of Rana esculenta 74 
68. Muscles of the shoulder, from 

below . 77 
69. Muscles of the right shoulder 

and upper arm = Gls 
70. Right shoulder, from below 79 
71. Muscles of the back and shoul- 

dere. 79 
72. Muscles of the chest, throat, 

and belly of Rana esculenta 81 
73. Muscle of right shoulder and 

upper arm . 83 
74. Muscles of the right arm of 

Rana esculenta . 2 84 
75. Do. (deep layer) 85 
76. Muscles of forearm of Rana es- : 

culenta 86 
77. Muscles of hand of Rana es- 

culenta, volar surface . 88 
78. Second layer of muscles on 

volar surface of hand of 

Rana esculenta . - 88 
79. Muscles of hand of Rana es- 

culenta A OF 
80. Muscles of left thigh of do. 95 
81, 82. Do. (ventral surface). 98, 99 


PAGE 


XIV 
FIGU 


83. 


84. 
85. 


86. 
87. 


88. 
89- 


92- 


95: 
96. 
97. 


100. 


101. 
102. 


103. 
104. 


105. 
106. 
107. 


108. 
HOD: 


110. 
Lit. 


112. 
113. 


114. 


ILLUSTRATIONS. 
RE AGE | FIGURE AGE 
Deep muscles of left thigh ue 115. Dissection of the floor of fhe 
Rana esculenta . + 100 mouth (coloured) Plate I. 
Do. (Dorsal view) . 101 | 116. Right half of skull of Rana es- 
Left half of pelvis of Rana es- culenta 174 
culentæ  . 101 | 117. The nervous system of Rana 
Muscles of the right leg and esculenta, from the ventral 
foot of Rana esculenta (Dor- surface : 176 
sal view) : . 103 | 118. Ventral view of the brain and 
Do. (seen from below) : . 105 spinal cord, to show the 
Do. (Dorsal view) - 106- points of exit of the spinal 
91. Muscles of the plantar sur- nerves 178 
face of foot of Rana escu- 119. Ventral view of the spinal 
lenta . 107, LE ete ganglia - 2 170 
94. Dorsal view of muscles of 120. Schema of spinal ganglion =; 179 
foot of Rana esculenta 121. Dorsal branches of the spinal 
LIS LL 7, LLS nerves 5 . 181 
Pectoral region of Rana es- 122. The brachial plexus . . 184 
culenta 119 | 123, 124. Nerves of the ventral sur- 
Hind portion of back and ‘thigh face of the arm . . 185, 186 
of Rana esculenta 120 | 125. The N. radialis 186 
The nervous system of Rana 126. Ventral view of the brain and 
esculenta, from the ventral spinal cord . . 188 
surface à 136 | 127. The sciatic plexus . 190 
. Dorsal view of brain of Rana 128. Distribution of the sciatic nerve 193 
esculenta 143 | 129. Nerves of the leg and sole of 
. Transverse section through the foot . 194 
hinder end of Medulla ob- 130. Distribution of the N. peroneus 196 
longata . 144 | 131. Sympathetic cord 198 
Do. at the point of origin of 132. The heart and blood- vessels, 
the abducens nerve 145 seen from the ventral sur- 
Do. of the auditory nerve 146 face : . 213 
Ventral view of brain of Rana 133. The heart, seen from above AA 
esculenta 149 | 134. The frog’s heart, seen from the 
Lateral do. 150 ventral surface 215 
Transverse section through the 135. Dissection of a case in which the 
anterior portion of the optic auricular septum is placed 
lobes opposite the origin of more to the left than is 
the motor-oculi nerve. I51 normal 215 
Horizontal section through the 136. Dissection of the heart from the 
brain to show the ventricles 153 left side 216 
Section through the lower di- 137 I. Transverse section through 
vision of the pituitary body 157 the junction of the hinder 
Transverse section through the and middle thirds of the 
hinder portion of the cere- ventricle of Rt. temporaria . 217 
bral hemispheres 158 | 137 II. Tranverse section through 
Transverse section near the junction of the middle and 
middle of the cerebral hemi- anterior thirds of the same 
spheres = . 158 heart . 217 
From a transverse section 138. Portion of a transverse section 
through one of the cerebral through the middle of the 
hemispheres 159 ventricle of R. temporaria . 218 
Diagram to show the “Vena 139, Course of the cardiac nerves in 
spinalis posterior, etc. . . 164 the auricular septum . - 219 
Dorsal view of the orbit, ete. 140. Group of nerve-cells on the car- 
(deep dissection) (coloured) diac nerve, from the auri- 
Plate I. cular septum. 220 
Do. (superficial do.) (coloured) 141a. Small group of nerve-cells from 
Plate I. the auricular septum . 221 
View of roof of mouth; mu- 141b. Isolated nerve-cells from frog’s 
cous membrane,etc.(coloured) heart . : 221 
Plate I. | 142. Arteries and veins of the 
Lateral dissection of head, etc. Truncus arteriosus of Bufo 
(coloured) Plate I. vulgaris. . 5 202 


FIGURE 
143. 


144. 
145. 


146. 
147. 


148. 


149. 


150. 
151. 
152. 
153. 


154. 
155. 


156. 
157. 


158. 
159. 


160. 


161. 
162. 
163. 
164. 
165. 
166. 
167. 


168. 
169. 


170. 
IAE 
172. 
173. 
174. 


175. 


ILLUSTRATIONS. XV 


Schema of the arterial system 
of Rana esculenta 

Right carotid gland 

Arterial system of Rana escu- 
lenta . 

Transverse section at level of 
the larynx . : 

Dissection to show the occipito- 
vertebral and the cutaneous 
arteries 

Branches of the oecipito- verte. 
bral and cutaneous arteries 
in the head 

Dissection to show the occipito- 
vertebral and the cutaneous 
arteries : 

Subclavian artery of the left 
side . 

Arteries of the palmar surface 
of the hand 

Arteries of the dorsal surface of 
the hand 

Arterial system of Rana escu- 
lenta . 

The urinogenital arteries 

Bifurcation of the aorta and the 
iliac arteries : 

Arteries of the hinder ex- 
tremity . 

Arteries of the dorsal surface of 
the foot 5 

Arteries of the sole of the foot 

Schema of the veins of Rana 
esculenta 

Distribution of the internal 
jugular vein and the an- 
terior portion of the cuta- 
neous vein. 

The anterior caval vein and its 

branches. 

Course of the cutaneous vi vein as 
seen from the side 

Veins in the region of the 
kidney : 

Veins of the liver : 

Veins of the hinder extremity . 

Transverse section of a septum 
with the attached skin 

The sinus abdominalis lateralis 

Sinus thoracicus transversus 

The lymph-sacs of Rana escu- 
lenta (seen from the dorsal 
surface)  . 

Do. (seen from the ventral do.) 

Do. (seen from the side) . : 

Transverse section through the 
trunk in the region of the 
iliac lymph-sac € 

Dissection to show the iliac 
lymph-sac . 

Plan of attachments of the in- 
ferior femoral etc. septa 

Transverse section of the thigh 


PAGE 


225 
(224 


225 


226 


. 227 


. 228 


229 
231 
232 


5 ABP 


- 234 
. 235 


220 


237 


- 239 
240 


242 


+ 243 
- 244 
245 


FIGURE PAGE 
176. The anterior lymph-hearts . 261 
177. The posterior lymph-hearts . 261 
178. The roof of the mouth . : 276 
179. The floor of the mouth . 277 
180. The capillaries of the sub- 
mucous layer (coloured) Plate IT. 
181 1. Transverse section of the pre- 
maxillary bone, to show at- 


tachment of the teeth . . 279 
181 IT. Dentine and enamel . . 279 
181 III. Enamel . - 279 
182, 183. Muscles of the tongue 281, 282 
184. The alimentary canal. 25 
185. The abdominal viscera of Raza 

esculenta. 284 
186. Longitudinal folds of stomach 

of Rana temporaria . 285 


187. The cells at the mouth of the 
gland of the fundus of the 
stomach . (coloured) Plate II. 

188. The mucous membrane of the 
pyloric end of the stomach of 
Rana esculenta . 4 . 286 

189. Mucous membrane of the 
pyloric end of stomach and 
duodenum . 5 . 288 

190. Isolated fold of mucous mem- 
brane of small intestine of 


Rana temporaria : 291 
191. Fold of mucous membrane of 
Rana temporaria : 291 
192. The large intestine of Rana 
temporaria - + 292 
193. Large intestine of Rana escu- 
lenta . : 2 = - 293 
194. The liver : . 295 


195. The pancreas and bile-canals . 296 
196 I. The hepatic veins 

196 II. (coloured) Plate IT. 

The hepatic arteries 

ae (coloured) Plate IT. 
197. Liver-cells  . : = - 299 
198. The bile-capillaries . = - 299 
199. The pancreas and bile-canals . 300 
201. The peritoneum of Rana escu- 


lenta . 305 
202. The position and relations of 
the larynx . 311 
203. The cartilaginous skeleton of 
the larynx . = 312 
204. The larynx and surrounding 
parts . Soars 


205. The muscles of the larynx EU 
206. Three sections through the la- 
rynx of Rana esculenta . 316. 
207. The Rima glottidis : s Buy 
208. The lung of Rana temporaria 
(coloured) Plate IT. 
209. The vocal sac of the right 


side . - A . 320 
210. The thymus gland : - + 321 
211. The thymus gland of Rana 

esculenta . - 7320 


XVI 
FIGURE PAGE 
212. The thyroid gland of Rana 
esculenta. 323 
213. The lymphatic gland of Rana 
esculenta . : . 324 
214. The male urino-genital organs . 331 
215. The right kidney . - 202 
216. The blood vessels and lym- 
phatics of the kidney . + 333 


217. Vertical sections through the 
kidney (coloured) Plate IT. 
218. The uriniferous tubes  . 335 
219. A gold preparation of the kidney 
of Rana esculenta 
(coloured) Plate II. 
220. Transverse section of the aml 338 
221. The bladder . - + 339 
222. The male reproductive organs - 341 
223. Various preparations from the 
testis . > - 342 
224. The female reproductive organs 344 
225. Preparations from ovary and 
oviduct 3 : . 346 
226. The male urino- genital organs 348 
227. The fat-body of Rana esculenta 349 
228. The epidermis from the head of 


Rana esculenta . = 367 
229. Vertical section through the 

skin of the back . < 368 
230. Surface view of epidermis of 

Rana temporaria - . 368 


231. Nerve terminations of the 
branched pigment-cells of 


the cutis . 368 
232. The temporary papillae i in Rana 
temporaria . 371 


233. The epidermis of the supple- 
mental toe of Rana escu- 
lenta . 
234 I. Fore-foot of a male frog "OT 
234 II. The swelling on the supple- 
mental toe of a male frog . 375 
235. The blood-vessels and lym- 
phatics of the skin. 376 
236. Lateral sense-organ of tadpole 
of frog A 3 . 378 


ILLUSTRATIONS. 


FIGURE PAGE 
237. Various parts from the fungi- 
form papillae. 381 
238, 239. Frontal sections through 
the nose of two tadpoles . 384 
Bowman’s glands in situ 
from Rana temporaria . 386 
240 IB. Section of Bowman’s gland 386 
240 II. Vessels of nasal mucous 
membrane of Rana esculenta 386 
241. Separations from the olfactory 
mucous membrane of Rana 


240 Ta. 


temporaria . - 388 
242. The tympanic membrane of 

Rana esculenta . Fs - 389 
243. The columella - 391 


244. Antero-posteriorsection through 
the capsule of the right 
labyrinth of Rana esculenta 392 

245. The membranous labyrinth of 
Rana esculenta . = 394 

246. Part of the outer wall of the 
perilymphatic space . + 395 

247, 248. The right membranous 
labyrinth of Rana esculenta 397 

249, 250. The membranous labyrinth 
of Rana esculenta - 399, 401 

251. Preparations from the ear of 
Rana esculenta . : . 402 

252. The nerve-terminations in the 
membranous labyrinth of 
Rana esculenta . - - 404 

253. Endothelium from the inner 
surface of the sclerotic coat . 406 

254, 255. Preparation from cornea of 
Rana esculenta + 407, 408 

256. Thevesselsofthechoroidandiris 410 

257. Fibres from the lens of the frog 414 

258. Vertical section through retina 


of frog = . 415 
259. Various preparations from the 
eye of the frog . = -A17 


260. The vessels of the vitreous body 421 

261. Preparations from the nicti- 
tating membrane of Rana 
esculenta. 2 ; . 422 


INTRODUCTION: 


THERE is no occasion, now-a-days, to offer a lengthened apology 
for devoting a treatise solely to the anatomy of the frog, which enjoys 
the doubtful honour of being, kar’ é£oynr, the physiological domes- 
tic animal. It is kept in every physiological laboratory, and is daily 
sacrificed in numbers upon the altar of science. The physiologist 
has recourse to it, not only to obtain answers to new questions, but 
for the sake of demonstrating easily and quickly the most im- 
portant known facts of the science. These unlucky batrachians are 
to be had in any number, and are specially adapted for experimental 
investigation : they have consequently fallen under a harsher tyrant 
than the stork in the fable, and their prophetic outcry in the 
frog-chorus of Aristophanes, dewà weoduecda, has been literally 
fulfilled. 

As the history of the most important physiological discoveries is 
closely related with the employment of the frog in physiological 
research, it will not be without interest to review briefly the 
history of its use in scientific, especially in physiological, investi- 
gations, and to record the services which it has already rendered 
to science. Swammerdam (1637-1685), as du Bois-Reymond justly 
remarks, was the first to make known the frog as an important 
means of research; he says concerning it :—‘ An den Thieren, die 
das heisseste Blut haben, ist die Bewegung der Muskeln nicht so 
merklich oder hilt vielmehr nicht so lange an, als an Thieren die 
mit kilterem Blute begabt sind. Dergleichen sind die Fische und 
viele andere Wasserthiere, wie auch solche, die so wohl im Wasser als 
auf dem trocknen Lande leben kénnen. Deswegen habe ich inson- 
derheit mit dem Frosch meine Versuche angestellt. Denn an diesem 
Thiere sind die Sehnen sehr sichtbar und lassen sich leicht entdecken 

B 


2 INTRODUCTION. 


und entbléssen!. Swammerdam made the earliest experiments on 
the contraction of muscle by means of chemical and mechanical 
stimulation of its nerves; thus laying the basis of our present 
nerve and muscle physiology, which has been built up within rather 
less than two hundred years; though during the first half of this 
period but little advance was made. 

From the famous September evening of the year 1786, on which 
Galvani first observed the twitchings of a frog’s leg suspended by a 
metallic hook to an iron balcony, the frog has, down to the present 
time, afforded almost the only material for the investigation of the 
excitability of nerve and its associated electromotive changes, and also 
no inconsiderable part of the remaining nerve and muscle physiology. 
It was not until Müller devised the method of operating on the 
frog that Bell’s law became capable of easy proof; and much of 
our knowledge of the functions of the spinal cord is derived from 
experiment upon it. Again, the muscles of frogs served, from the 
time of Swammerdam to that of Eduard Weber and his followers, 
for the investigation of the phenomena and the conditions of con- 
traction; and in almost all other branches of physiology there are 
important doctrines which were first definitely established by experi- 
ment upon the frog. But for the web of the foot of this animal (and 
the gills and tail of its tadpole, in which Leeuwenhoek ? describes 
the phenomena most clearly) we should not, perhaps for a long 
time, have arrived at a satisfactory knowledge of the existence 
and the conditions of the capillary circulation. As is well known, 
an accurate acquaintance with the constituents of the blood directly 
concerned in nutrition has been obtained by observation on the 
frog, as well as important facts in the physiology of the blood and 
lymph, such as the intimate knowledge of the corpuscles of both 
fluids, and the coagulability of the plasma; while in no less degree 
have experiments on these animals served to establish the laws of 
the heart’s action. Moreover, physiology is not the only science 
indebted to the frog: in histology many important results have 
been obtained from observations on it, and for histological in- 
struction it is now indispensable. To it we owe much of our 


1 In animals with warm blood the action of the muscles is neither so apparent 
nor so long continued as in those animals which have cold blood, such as fishes and 
many other aquatic animals, and those also which live both in water and on dry 
land. On this account I have made my investigations chiefly on frogs, for in them 
the nerves are very distinct, and are easily found and exposed.’ Buch der Natur, 
Leipzig, 1752, p. 330. 

2 Leeuwenhoek, Arcana Nature ITI, epist. 65 ad Reg. Soc. Lond., p. 158. 


INTRODUCTION. 3 


knowledge of the structure of nerve fibres, their origin and termina- 
tion, especially in muscle, their relations within the ganglia, and 
even the structure of muscular fibre itself. For the study of 
reproduction and development the frog has, next to the chick, 
afforded the most important material: one need but refer to the 
investigations on impregnation from the time of Spallanzani to 
that of Newport!, the phenomena of cleavage, and many others. 

Thus with progress of time the field in which the frog has been 
submitted to observation and experiment, whether for the demon- 
stration of established facts to students or for the solving of new 
problems, has vastly increased, and this batrachian has indeed be- 
come, as we have stated, the physiologist’s domestic animal. 

That, for these manifold uses, a more exact anatomical know- 
ledge of the frog is very necessary is self-evident. The majority of 
students commencing the study of physiology have little more than 
a superficial knowledge of the sciatic nerve and the leg-muscles ; at 
most, of the spinal cord and its nerve-roots ; and only acquire any 
further knowledge in a disconnected manner. For this they can 
scarcely be reproached, the literature of the anatomy of the frog 
being so widely scattered in monographs and journals that reference 
to it involves the expenditure of much time. This attempt, there- 
fore, to produce a complete anatomy of the frog, based throughout 
upon my own observations, cannot be considered superfluous ; it is 
rather to be feared it may be thought insufficient. 

The European frogs? alone are treated of in the following 
description, i.e. the two species, Rana esculenta, L., and À. tempo- 
raria, L., the former being more particularly described, though 
such differences in structure as occur are noted. This is not 
the place to discuss the exact systematic characters of the two 
species, yet they cannot be ignored entirely. The species were, 
from their habitats, long ago distinguished by C. Gessner *, and 
named Rana rubeta, s. gibbosa, the garden or grass-frog, and Rana 
aquatica, s. innoxia, the water-frog ; at least, from his figure, the 
former can be no other than ZX. temporaria, though Gessner, 


1 Tt may be well to remind the reader that this introduction was written in 1864. 

2 For purposes of comparison other than European frogs were examined, especially 
American species of Rana, for which I am indebted to the kindness of my much _ 
esteemed friend Agassiz. These were Rana Catesbyana, Shaw (R. mugiens, Catesby— 
R. pipiens, Harlan); R. sylvatica, Leconte; R. clamitans, Daudin; R. palustris, 
Leconte ; R.halecina, Leconte. To these, however, no further reference will be made 
in the text. 

5 C. Gessner, Thierbuch. Zürich. Fol., p. 157. 

B 2 


4 INTRODUCTION. 


probably expecting to find in it the r#beta of older writers, adds 
that it ‘ist für giftig zu halten.’ 

Leeuwenhoek 1 also correctly distinguished between them, but it 
is to Rôüsel? that we are chiefly indebted for a careful discrimination 
and an accurate knowledge of the life-histories of the two species. 


The green water-frog, Rana esculenta L. 


Rana esculenta, L. The green water-frog, Fig. 1, usually attains 
a larger size ® and is more active than the other species, and for this 


1 Leeuwenhoek, Arcana Nature, Vol. III of Ecker’s edition. Leyden, 1722. Epist. 65 
ad Reg. Soc. Lond., p. 154. 

2 Rosel, Naturgeschichte der Früsche Deutschlands, ed. Schreber. Nürnberg, 1815, 
p. 36. 

3 The extreme sizes are much more pronounced in this species. I have never found 
R. temporaria of the size attained by large specimens of the water-frog. 


INTRODUCTION. 5) 
reason is better adapted to the purposes of the physiologist; hence 
I have chosen it for description. 

The head is flat, as broad as it is'long, and triangular with an 
obtuse snout in front. The upper surface of the head, £.e. the 
space between the eyes, is slightly concave, grooved, and narrower 
than in À. temporaria. The tympanic membrane is circular, and 
relatively to the eye is larger. The upper eyelids have several trans- 
verse folds in their hinder part. The pupil is oval, with the long 
axis horizontal. ‘The vomerine teeth are arranged in two clusters, 
which are relatively larger than in ZX. temporaria and lie exactly 
between the posterior nares, without however touching them. 
The openings of the Eustachian tubes do not exceed in size the 
posterior nares to so great an extent as they do in R. temporaria. 
The male possesses a vocal sac on either side, which reaches the sur- 
face beneath the tympanic membrane through a cleft placed behind 
the angle of the mouth, and is, in well-developed specimens, about 
the size of a cherry. The hind limbs are relatively longer. The 
toes are long, and taper towards their tips: the webs between the 
toes are cut out semicircularly, and that of the longest or fourth 
toe is continued to the tip of the last phalanx. The supplemental 
toe is an oval prominence of cartilaginous hardness. The skin 
of the back has wart-like tubercles arranged longitudinally in 
raised lines; one of these lines runs on each side from the posterior 
canthus as far as the thigh, and is very constant: in the male 
a second line surrounds the posterior margin of the vocal sac ; 
a corresponding: line exists in the female. 

The skin of the belly is quite smooth, the colour presenting 
many variations which appear to depend upon very diverse circum- 
stances. It varies with changes in the physiological condition of the 
animal. Von Wittich* has shown that a bright green specimen 
changes to a dark leafy green colour on exclusion of light; also, that 
dark specimens become almost a lemon-yellow colour on exposure to 
bright sunlight; and he has pointed out that this brightening of 
the skin is an active condition dependent upon contraction of the 
stellate pigment-cells. It is therefore not surprising, as the same 
inquirer observes, that one should sometimes find specimens of 
R. esculenta in which the ground colour is almost a greenish yellow 
(as in Rôsels figure, Pl. XIII), whilst in others it can only be 
distinguished from the dorsal black patches by a faint greenish 


1 Von Wittich, Miiller’s Archiv, 1854, p. 41. 


6 INTRODUCTION. 


shade. There is no doubt that difference of habitat influences the 
colour; but this may again be modified by light*, as has been 
established in the case of fish by direct observation’. Apparent 
varieties may thus occur. 

In frog-tanks such diversities of colour may not unfrequently be 
observed in the same individual, as for example when the lower part 
of the body immersed in muddy water is dark, while the part above 
the water is bright. That the process of casting the skin exercises 
an influence on the brightness of the colouring is certain, yet there 
are, as von Wittich has correctly remarked, other alterations of 
colour which are in no way connected with this process, and are 
evidently more of a pathological nature; such as when the frog 
assumes a dirty green spotted appearance, the green fading more 
and more, until all the patches which are usually green appear 
of a dirty greyish-brown with a faint bronze shimmer. According 
to this author these changes are most readily brought about by 
starvation. The dark colour which frogs exhibit after hibernation 
is perhaps to be ascribed to the co-operation of several of the causes 
mentioned above. 

The usual colouring of healthy animals is as follows: the back 
is bright green with three golden yellow longitudinal stripes, one 
median and two lateral, and a number of irregular brown or black 
stripes of approximately uniform width: on the head are a pair of 
black stripes which pass from the angles of the eyes across the nares 
to the tip of the nose ; now and then the tympanic membrane and 
surrounding parts have also a black patch, as in ZX. ¢emporaria : 
another black stripe is found on the anterior surface of the arm, in 
the region of the shoulder: and on the thighs are black, yellow, and 
white mottlings. The whole of the under-surface is white or 
yellowish. At times the yellow stripes of the back are wanting or 
are indistinct. It has already been mentioned that many varieties 
may oceur; and these have in all probability given rise to the de- 
scriptions of reputed new species, such as À. maritima, Risso, found 
in South Europe; À. alpina, Risso, found in the high-lying Alpine 
lakes; R. hispanica of Fitzinger and Bonaparte, and 2. calcarata of 
Michahelles, the last three of which certainly cannot be retained. It 


1 Lister, On the Cutaneous Pigmentary System of the Frog. Phil. Trans., 1857, 
p. 627. 

? Agassiz et Vogt, Histoire naturelle des poissons d’eau douce (Neuchatel, 1839), 
Pl. IV, mention that the colour of trout is very variable and that in shaded and 
deep-lying brooks and rivers a variety is found which is black. 


INTRODUCTION. gi 


is not improbable that the water-frog, which Spallanzani! used in 
his experiments on impregnation, was the A. maritima of Risso. He 
says, one must not confound his frog with that which Résel calls the 
green water-frog ; the former being much smaller, without the three 
dorsal golden-yellow stripes, and the spawning season (in Lom- 
bardy) occurring during April and May. Rusconi? also describes 
two varieties in Northern Italy. 


Rana temporaria, L., the brown or grass-frog, is so named from 
the large black patch in the temporal region, z.e. between the eye 
and the shoulder. While the separation of the preceding species 
into several varieties does not seem to be well founded, it appears 
that two distinct species have been included under the name of 
R. temporaria. Mallet of Angers? first described, in his Fauna du 
département de Maine-et-Loire, as ‘grenouille rousse” a species 
differing from R. temporaria, and gave the species previously known 
as À, temporaria the name of R. flaviventris, “grenouille à ventre 
jaune” No further notice, however, was taken of this observation, 
not even by Duméril and Bibron in their ‘ Erpétologie” Quite mde- 
pendently Steenstrup*, in the year 1846, pointed out that two frogs, 
differing in structure and habits, had been confounded under the 
name À. temporaria; these he distinguished as ZX. platyrhinus and 
R. oxyrhinus. Von Siebold®, and also Schiff® in part, have confirmed 
these statements. My own observations lead me to a like conclu- 
sion; I shall therefore distinguish two species, viz.:—(1) Pana 
temporaria, L., Rana platyrhinus, Steenstrup ; (2) Rana oxyrhinus, 
Steenstrup. 


Rana temporaria, L.; /ana platyrhinus, Steenstrup. The brown 
erass-frog, Fig. 2, does not attain the dimensions of X. esculenta, L., 
but is, however, always larger than 2. oxyrhinus. The head is 
somewhat broader than long, and the upper surface of the skull 
is not grooved, as in 2. esculenta, but is flat. The space between 
the eyes is wider (according to Duméril, equal to the width of the 
upper eyelid, whereas in ZX. esculenta it is just two-thirds this 


1 Spallanzani, Versuche über Erzeugung der Thiere und Pflanzen. Leipzig, 1786, 
P- 5. 

2 Rusconi, Développ. de la Grenouille. Milan, 1826, p. 6. 

3 Annales des Sciences naturelles. Zoologie, IV Série, Vol. IV, 1855, p. 368. 

* Amtl. Bericht über die 24. Versammlung deutscher Naturforscher in Kiel, 1846, 
p- 141; Wiegmann’s Archiv, 1847, Vol. II, p. 341; Steenstrup, Oversigt K. Danske 
Selsk. Forhandlgr., 1846, p. 92. 

5 Wiegmann’s Archiv, 1852, Vol. I, p. 14. 

6 Annales des Sciences naturelles. Zoologie, IV Série, Vol. IV, 1885, p. 368. 


8 INTRODUCTION. 


width): the fronto-parietal bones are wide and flat. The tympanic 
membrane, in comparison with the eye, is smaller than in À. esculenta, 
and is usually less distinguishable from the surrounding parts as 
regards colour and transparency. The apertures of the Eustachian 
tubes are, relatively to the posterior nares, larger than in the water- 
frog. The vomerine teeth are comparatively small and lie in two 
eroups placed obliquely to each other, their anterior ends diverging 
from each other and being prolonged as ridges to the anterior 
margins of the posterior nares. The two groups do not lie between 


The brown grass-frog, Rana temporaria, L. 


the nasal apertures, but behind a line drawn transversely through 
their posterior margins. Vocal sacs are absent in both sexes. 
The hind legs are relatively shorter: the toes are not so evenly 
tapered off, indeed they are slightly swollen: the fourth toe, 
as compared with the third and fifth, is somewhat longer than in 
À. esculenta; the web of this toe does not extend to the tip of the 
toe, but terminates in both sexes at the last phalanx but one; the 
web on the third toe is less developed on the thumb side than 
on the other: on the remaining toes also the margins of the web 


INTRODUCTION. 9 


are less developed than in À. esculenta, so that the free borders 
appear more crescentic. The supplemental toe forms only a 
soft and inconspicuous prominence. The back is mostly smooth ; 
the raised glandular ridge, which extends along each side from 
the eye to the thigh, is present, but is much narrower and less 
prominent than in À. esculenta; another ridge passes from the 
angle of the mouth to the shoulder. The colouring in general, and 
especially the ground colour of the dorsal surface, varies from the 
brightest tints to the darkest brown-black ; the conditions causing 
these variations being, no doubt, the same as those described above 
in 2. esculenta. A dark-brown specimen taken from a dark frog- 
tank is usually yellowish red on the following day. The black 
patch between the angle of the mouth and the shoulder has 
given this species the name of À. {emporaria, and is constant. A 
black stripe passes from the eye across the nostril to the tip of 
the snout, and a similar one is found upon the anterior surface 
of the upper arm. On the hind legs the bands are chiefly trans- 
verse. The ventral surface is yellowish, and sometimes spotted. 
The thighs have a granular appearance, and these as well as the 
belly and the neighbourhood of the anus have frequently a reddish 
coloration presenting the appearance of an irritated surface. 


Rana oxyrhinus, Steenstrup. This species is always smaller and 
more elegant in shape than the preceding one. The head is conical, 
with the pointed snout projecting beyond the lower jaw; a feature 
which is especially evident on looking from below. The space be- 
tween the eyes is narrower than in ZX. temporaria, and is not 
grooved, but convex; the fronto-parietal bones are narrow and 
arched. With respect to the arrangement of the vomerine teeth 
and the sizes of the apertures of the Eustachian tubes, this species 
holds an intermediate position between the other two. Next to 
the pointed snout, the greatest difference between this species and 
R. temporaria is the presence of a much larger supplemental toe, 
which is of cartilaginous hardness, compressed from side to side, 
and contains a larger bone!. The vocal sacs are absent. In the 
males the web of the longest toe reaches to the last phalanx but 
one; in the females, on the contrary, the last three phalanges pro- 
ject freely beyond the web. The extremities of the toes are more 
pointed than in À. {emporaria, in which respect, as also in several 


1 According to Steenstrup, J. c., the size of the supplemental toe is in À. temporaria 
one-half and in R. owyrhinus two-thirds of that of the next toe. 


10 INTRODUCTION, 


others, it approaches ZX. escu/enta. In colouring, À. oayrhinus re- 
sembles À. temporaria; the throat, however, is usually pure white, 
at least in the males, the breast dusky white and spotted, while in 
R. temporaria the throat and breast are more uniformly coloured 
and yellowish. V. Siebold has remarked that, during the pairmg- 
season, the males are covered with a bluish bloom!; and, the 
whole ground colour being bright at this period, very beautiful 
tints result. WV. Siebold* moreover states that the note which the 
males produce during the pairing-season is different in the two 
species. On the whole, À. oxyrhinus appears to stand midway 
between 2. esculenta and À. temporaria. 

Thomas*, in addition, distinguishes another species, 2. agilis, 
which however may be the ‘ grenouille rousse? of Millet. Schlott- 
hauber{ has described a frog which, in marking and colouring, might 
hold a middle place between 2. esculenta and À. temporaria; in my 
opinion this is probably a cross between the two. That attempts at 
copulation are made, despite the difference of the pairmg-season, is 
well known ; Pontallié5 mentions this, and I have myself often found 
males of À. temporaria in conjunction with females of L. esculenta. 


I use the following terminology. I suppose the animal to be in 
its natural position, the belly towards the ground, the back up- 
wards; a horizontal plane passing from the snout to the anus 
divides the body into a superior or dorsal half and an inferior or 
ventral half. The terms superior and inferior, dorsal and ventral, 
indicate positions with relation to this plane. I call that part 
anterior which looks towards the head, and that posterior which 
looks towards the anus. A vertical plane at right angles to the 
middle of the longitudinal axis of the body, divides it into an 
anterior or cephalic and a posterior or caudal half. All sections 
and planes which lie parallel to this, as well as this itself, are frontal. 
Lastly, by a perpendicular section along the middle line of the body 
the animal is divided into right and left halves; this plane is the 
median plane; and the position relative to this plane is expressed 
by the terms median or lateral. Planes parallel to the median plane 
are termed sagittal. 


1 T do not find, however, that this disappears when the animals are on land; in 
fact I have animals before me in a glass in which it is plainly seen. 

ETC PTE 

3 Annales des Sciences naturelles. Zoologie, IV Série, Vol. IV, 1855. 

* Wieswmann’s Archiv, Vol. I, 1844, p. 255. 

5 Annales des Sciences naturelles, Zoologie, III Série, Vol. XVIII, 1852, p. 243. 


SECTION I. 


THE BONES AND JOINTS. 


THE BONES AND JOINTS. 


LITERATURE. 


van Altena, Commentatio ad quest. zoologicam in academia Lugduno-Batav. 
a. MDCCCXXVIII propositam, qua desideratur ut systematice enumerentur species 
indigenæ reptilium ex ordine batrachiorum addita unius saltem speciei anatomia 
et præsertim osteographia accurata. Lugd. Bat. 1829. 4°. With 4 Plates. 

Ange, Martin St., Recherches sur les organes transitoires des batraciens. Annales 
des Sciences naturelles. 1r° Série. Vol. XXIV. 1831. 

Bell, Article Amphibia, in Todd’s Cyclopaedia of Anatomy and Physiology. Vol. I, 
p.90. 1835-1836. 

Born, Dr. Gustav, Ue.d. Nasenholen u.d.Thränennasengang der Amphibien. Leipzig, 
1877. 

Bruch, G., Beiträge zur Naturgeschichte und Klassification der nackten Amphibien. 
Wiirzburger Naturzeitschrift, 1862. 

Bruch, G., Neue Beobachtungen zur Naturgeschichte der einheimischen Batrachier. 
Wiirzburger Naturzeitschrift, 1863. 

Cuvier, Recherches sur les ossements fossiles. Vol. V. Pt. II. Paris, 1825. 

Cuvier, Lecons d’anatomie comparée. Paris, 1835. Vol. I. 

Cuvier, Ueber die Riickenwirbel der Reptilien und Amphibien, Froriep’s Notizen. 
Vol. XIII, p.74 1826. 

Daudin, Histoire naturelle des Rainettes, Grenouilles et des Crapauds. Paris, 1802. 

Ducrotay de Blainville, Ostéographie ou description iconographique comparée du 
squelette et du système dentaire des cinq classes d'animaux vertébrés. Paris, 
1841. 

Dugès, Recherches sur l’ostéologie et la myologie des batraciens à leurs différents 
âges. Paris, 1834. 4°. With 20 Plates. 

Duméril et Bibron, Erpétologie générale ou Histoire complète des Reptiles. 1836. 

Gegenbaur: 1. Ueber Bau und Entwicklung der Wirbelsäule bei Amphibien über- 
haupt und beim Frosche insbesondere. Abhandlungen der naturforschenden 
Gesellschaft zu Halle, Vol. VI. Halle, 1861. 
2. Untersuchungen zur vergl. Anatomie der Wirbelsiiule bei Reptilien und Am- 
phibien. Pt. I. Leipzig, 1862. (Carpus and Tarsus.) With 4 Plates. 4°. 
Gegenbaur, Untersuchungen zur vergl. Anatomie der Wirbelthiere. Pt. II. 
Schultergiirtel. 1865. 

Gunther, Ueber geschlechtliche Differenzen in Knochen von lebenden und fossilen 
Fréschen und Fischen. Annals of Natural History. 1859. Vol. III. 

Hallmann, Die vergleichende Osteologie des Schlafenbeins, etc. Hannover, 1837. 
4°. With 3 Plates. 

Hoffmann, C. K., Beitrage zur Erkenntniss des Beckens der Amphibien und Reptilien. 
Leyden, 1876. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs, Vol. VI. 
Amphibien. Leipzig, 1873-8. 

Huxley, On the Theory of the Vertebrate Skull; Croonian Lecture, Proc. Royal 
Society, p. 381. 1858. 

Huxley, Article Amphibia, Encyclopedia Britannica, IXth Edition. 1875. 

Huxley, Lectures on the Elements of Comparative Anatomy. 

Huxley, Handbuch der Anatomie der Wirbelthiere. Deutsche Ausg. von T. Ratzel. 
1873. 

Kehrer, G., Beitriige zur Kenntniss d. Carpus und Tarsus d. Amphibien, Reptilien, 
und Säuger. Berichte d. naturf. Gesell. z. Freiburg. 1886. 


14 THE BONES AND JOINTS. LITERATURE. 


v. Klein, Beitriige zur Anatomie der ungeschwiinzten Batrachier. Jahres-Heft. 
Wiirtemberg, 1850. 

Kôstlin, Der Bau des knéchernen Kopfs. Stuttgart, 1844. 8°. 

Leukart, Zwischenkiefer. Valentins Repertoire. 1841, p. 155. 

Marshall, A. M., The Frog. Manchester and London. 2nd Edit., 1885, pp. 45-50. 

Mayer, A. F., Beiträge zu einer anatomischen Monographie der Rana pipa. Acad. 
Caes. Leop. Nov. Acta. 1825. Vol. XII, p. 527 ; and Isis v. L. Oken. 1825. col. 317. 

Meckel, System der vergleichenden Anatomie. II.Thl. I. Abthlg. Halle, 1824. 8°. 

Meckel, Ueber das Zungenbein der Amphibien. Meckel’s Arch. f. Physik, 1818. 
Vol. IV, p. 60. 

Mertens, Anatomie batrachiorum prodromus sistens observationes nonnullas in 
osteologiam batrachiorum nostratium. Halæ, 1820, 8°. 

Mivart, On the Classification of the Anurous Batrachians. Proc. Zool. Soc. 1869. 
Morren, Observations ostéologiques sur l’appareil costal des batraciens. Bulletins 
de Acad. de Bruxelles, 1835, I1.—Mémoires de l’Académie, 1837. Tome X. 
Miller, Beitrag zur Anat. d. Amph. Zeitschrift f. wissenschaftliche Zoologie. 

Vol. IX. 1858, p. 178. 

Parker, W. K., Structure and Development of the skull of the common frog. Phil. 
Trans. 1871, p. 137. 

Parker, W. K., Skull of Batrachia. Phil. Trans. 1876, p. 601. 

Parker, W. K., and Bettany, G. T., Morphology of the Skull. London, 1877. 

Pouchet, Note sur les différences que le sexe imprime au squelette des grenouilles. 
Comptes rendus. Vol. XXV, p. 761. 1847. 

Reichert, K. B., Vergleichende Entwicklungsgeschichte des Kopfs der nackten 
Amphibien nebst den Bildungsgesetzen des Wirbelthierkopfs im Allgemeinen 
und seinen hauptsiichlichen Variationen durch die einzelne Wirbelthier-Classe. 
KGnigsberg, 1838. 

Remak, Untersuchungen über die Entwicklung der Wirbelthiere. Berlin, 1855. 

Rôsel, von Rosenhof, Historia naturalis ranarum nostratium. Nornberg, 1758. 

Rudolphi and Breyer, Observationes anatomicae circa fabricam Ranae pipae. 
Berolini, 1811. 

Rusconi, Développement de la grenouille commune. Milan, 1826. 

Rusconi, Sulle metamorfosi delle osse della testa della rana. Annali di Bologna. 
rre Série, Vol. II, p. 357. d 

Schneider, Historia amphibiorum. Jenae, 1799. 

Shaw, General Zoology. London. Vol. II, Pt. I, p. 167. 

Stannius, Zootomie der Amphibien (Handb. der Zootomie der ‘Wirbelthiere, 
2. Buch). 2nd Edit. Berlin, 1856. 8°. 

Stricker, Untersuchungen tiber die Entwicklung des Kopfes der Batrachier. Arch. 
f. Anat. u. Physiol. 1864, pp. 52-76. 

Stricker, Beiträge zur Biologie der Batrachier. Verhandl. der Wiener Akademie. 
1866. Vol. XVI, pp. 451-456. 

Townson, R., Facts and Observations in Natural History. London, 1799. 

Troya, Mémoire sur la structure singulière du tibia et du cubitus des grenouilles et 
des crapauds. Mémoires de mathématique et de physique présentées à l’acad. 
de Paris. Vol. IX. 1780. 

Wagner, Icones Zootomicae. Leipzig, 1841. 

Wagner, Lehrbuch der vergleichenden Anatomie. Leipzig, 1834-1835. 

Wiedersheim, R., Lehrbuch d. vergleichenden Anatomie der Wirbelthiere auf 
Grundlage d. Entwickelirigepeschichte, Jena, 1886. 2nd Edit. 

Wiedersheim, R., Elements of Comparative Anatomy of Vertebrates, translated by 
W. Newton perce London, 1836. 


THE BONES AND JOINTS. 


THE consideration of the differences in form, number, and histo- 
logical structure, which the parts of the skeleton present during 
the various stages of development does not fall within the scope of 
this book: we have here but to deal with the adult frog. 

The skeleton is made up of histologically different materials ; 
these are :—(1) bone, (2) hyaline cartilage, and (3) so-called cal- 
cified cartilage. Concerning the last it is necessary to make 
some observations. I have chosen for it the name calcified car- 
tilage in place of the more usual names ‘cartilaginous bone’ or 
‘primordial ossification, as by this term its nature appears to 
be expressed without any ambiguity’: it is hyaline cartilage 
in which calcareous particles have been deposited to a greater or 
less extent: in the fresh state it has the appearance of moderately 
firm cartilage; when dry it becomes opaque and white, like the 
calcareous crusts on the cartilages of the Plagiostomata. The cal- 
careous material is deposited in the cartilage in finer or coarser 
granules ; after removal of the lime by means of acids, the cartila- 
ginous structure becomes apparent although not so perfectly as in 
unchanged cartilage. 

This calcified cartilage is widely distributed in the frog’s skeleton : 
very many parts, which in higher animals consist only temporarily 
of this substance during the transition from cartilage to bone, are in 
the frog formed of it throughout life. It is especially well-marked 
in the epiphyses of the long bones in the hand and foot, in the 
bones of the shoulder-girdle, ete. To avoid repetition later on I will 
briefly describe it as found in the first-mentioned situation. Dugés” 
has described its external appearance, while Bruch*® has made us 

u Compare Müller, Zeit. f. wissen. Zoolog., Vol. IX. 

* Dugès, Recherches sur l’ostéologie et la myologie des batraciens à leurs différents 
âges, p. 116. 


* Bruch, Beïträge zur Entwicklungsgeschichte des Knochensystems, Schweiz. 
Denkschriften, p. 118. 


16 THE BONES AND JOINTS. 


acquainted with its histological peculiarities. If a long bone of the 
frog be dried, the femur for example, the middle part is found to 
differ considerably from the epi- 
physes in colour and in other par- 
ticulars. The shaft alone has the 
appearance of bone, the epiphysis 
consisting of a white, opaque, firm 
substance, resembling plaster of 
Paris or lime, but which iff the 
fresh moist state is exactly like 
cartilage. The epiphyses, which 
are fitted to the ends of the dia- 
physis like the cap of a stick- 
handle, have sharply defined mar- 
gins (Fig. 3), as is well seen in 
Figs. 36, 39, 45,and 46. Ifa sec- 
tion be made through the epiphysis 
Longitudinal section through the upper ex- and part of the diaphysis, the long 
tremity of the femur of Rana eculnia, tube of true bone is seen to cease 
à Hyaline cartilage (articular cartilage). abruptly above 0; Fig + 3 and over 

c Hyaline cartilage closing end of bony the end of it the epiphysis Z is 


Fig. 3. 


cylinder. 4 à : i 
e’ Calcified cartilage of epiphysis. fixed. This epiphysis consists al- 
D Bony cylinder of diaphysis. 5 =e = 
E Epiphysis. most entirely of calcified cartilage 
ler ar c’, and has merely a superficial 


o End of diaphysis. J : 
layer of hyaline cartilage 4. The 


bony cylinder of the diaphysis 0, which contains the marrow J/ in 
its interior, is shut off from the epiphysis by hyaline cartilage, the 
cells of which are arranged in transverse layers, 0. 


I. THE VERTEBRAL COLUMN. 


The vertebral column of the frog consists of ten bones, r#z. nine 
true vertebrae, and the rod-shaped urostyle, which alone is almost as 
long as all the remaining vertebrae. 


I. GENERAL DESCRIPTION OF THE NINE VERTEBRAE. 


a. The dodies of the vertebrae are compressed from above down- 
wards; the posterior surface of each body, with the exception of 


THE VERTEBRAL COLUMN. ie 


the eighth, presents an articular head covered with cartilage; the 
anterior surfaces, with the exception of the ninth, present corre- 
sponding articular depressions, covered with cartilage. 


b. The arches, which have some- Fig. 4. 
what sharp margins both before and 
behind, bear the following pro- 
cesses : 


te 


1. The articular processes (Figs. 
4 and 500) are similarly placed 
to those of the dorsal vertebrae of 
man: they project horizontally, the 
cartilaginous articular surfaces on 
the posterior processes being directed 
downwards, those on the anterior 
upwards, 


2. The transverse processes 
(Figs. 4 and 5 ¢7’) are strong, flat, 
and of very varying size and direction. 
The transverse processes of the fourth 
vertebra are the longest, those of the 
third only a little shorter ; the shortest 
are those of the seventh and eighth. 
The atlas has no transverse pro- 
cesses. Those of the second and third 
vertebrae project directly outwards 
and slightly downwards; those of 
the fourth, fifth, and sixth upwards 
and backwards. The seventh and 
eighth project more directly outwards 
and at the same time backwards ; 
the ninth upwards and markedly 
backwards. All the transverse pro- 
cesses have cartilaginous epiphyses ; 
the largest are those of the second, vertebrae of Rana zeculenta, seen from 


third, fourth, and ninth vertebrae. eee 
L x to 9 First to ninth vertebræ. 
8. The spinous processes are © Urostyle. 


generally small, but individually of Sib Re DR Loner Te with the 
varying’ size, appearance, and direc- HS 

tion. The longest are those of the third, fourth, and fifth vertebrae ; 
these are, in transverse section, of a three-sided prismatic form, as 


C 


18 THE BONES AND JOINTS. 


in the dorsal vertebrae of man; they are directed backwards and 
provided with cartilaginous epiphyses. The spmous processes of the 
sixth and seventh are shorter, compressed from side to side, project 


Fig. 5. 


Vertebral column of Lana esculenta, from 
above, twice nat. size, 

x to 9 First to ninth vertebræ. 

ce Urostyle. 

oo Articular processes. 

se Facets for articulation with the urostyle. 

tt’ Transverse processes, 


directly upwards, and are usually 
without cartilaginous  epiphyses ; 
that of the eighth is still shorter. As 
regards the spinous processes, those of 
the third, fourth, and fifth vertebrae 
resemble those of the dorsal vertebrae 
in man; those of the sixth, seventh, 
and eighth, lumbar vertebrae. The 
ninth has either no spinous process or 
only a rudimentary one. The first and 
second vertebrae may be looked upon 
as cervical vertebrae: the second has 
a short spinous process with a car- 
tilaginous epiphysis. In the first, the 
cartilage which unites the two halves 
of the arch represents the rudiment 
of a spinous process. 


II. DESCRIPTION OF PARTICULAR 
VERTEBRAE. 


1. The atlas or first vertebra has 
a thin body, compressed from above 
downwards, and an arch. The body 
has posteriorly a slightly raised, car- 
tilaginous, articular head, which is 
broader transversely : in front it has 
two oval articular facets, which are 
separated from each other by a median 
projection. Each facet is concave, 
and directed forwards, outwards, and 
slightly upwards. The arch is com- 
pleted above by cartilage, which pro- 
jects slightly to form the rudiment ofa 
spinous process. The hinder margin of 
the arch bears two articular processes. 
Transverse processes are wanting. 


2. The second vertebra presents all the general characters of an 


THE VERTEBRAL COLUMN. 19 


ordinary vertebra, except that the transverse processes are directed 
somewhat downwards. 

3. The transverse processes of the third vertebra are longer than 
those of the second : each is directed. downwards, is broader at its 
extremity than at its base, and bears a hammer-shaped cartilaginous 
epiphysis larger than those of the remaining transverse processes. 

4. The transverse processes of the fourth vertebra are the 
longest: each is broader at its free end than at its base, is 
directed upwards and backwards, and provided with a cartilaginous 
epiphysis. 

5, 6, 7. The transverse processes of the fifth, sixth, and seventh 
vertebrae are smaller, contracted towards their free extremities, and 
directed upwards. 

8. The eighth vertebra is distinguished from the rest by its 
body possessing no articular head. It presents, at each end, a con- 
cave articular depression. The transverse processes resemble those 
of the seventh. 

9. The ninth vertebra unites the vertebral column with the hip- 
bones, and is hence to be regarded as a sacrum. The body bears 
on its anterior surface an articular head for articulation with the 
eighth vertebra: on its posterior surface are two small rounded 
and closely approximated processes (Figs. 4 and 5 sc) for articulation 
with the urostyle. The transverse processes are strong, broader at 
the free ends than at their origin, directed upwards and backwards, 
and provided with cartilaginous epiphyses. 


III. ARTICULATIONS OF THE VERTEBRAE. 


The articular heads and depressions of the vertebral bodies, 
together with the joint surfaces of the articular processes, are 
covered with hyaline cartilage. The periosteum of the bodies, as 
also that of the articular processes, forms true capsular joint liga- 
ments. The articulations of the vertebrae are still further strength- 
ened by longitudinal fibres, which extend along the anterior and 
posterior surfaces of the vertebrae, and correspond to the ligamentum 
vertebrale commune anticum et posticum of man. Between the 
vertebral arches are membranes which represent the Zgamenta 
intercruralia. Between the spinous processes are bands of connective 
tissue which form /igamenta interspinalia. (For the articulation of 
the atlas with the occiput, see page 24.) 


C2 


20 THE BONES AND JOINTS. 


IV. STRUCTURE OF THE VERTEBRAE? (Figs. 6 and 7). 


Each vertebral body consists of a cylinder of compact bone, which 
is directly continued into the bony substance of the arch. In the 
interior of the cylinder is found an isolated persistent vestige of the 
chorda dorsalis (Ch): this is surrounded by cancellous bone (c), which 
extends backwards towards the articular head and forwards directly 
into the articular cartilage, compact bone being absent in these 
parts. In a transverse section of a ver- 
tebral body the following parts are seen 
(Fig. 6):—a. An outer layer of compact 
bone (0) (the transverse section of the 
above-mentioned cylinder), which is formed 
of parallel lamellae of varying thickness. 
These, according to Gegenbaur, and as I 
can confirm, are arranged in well-defined 
groups, each of five to eight lamellae. 


Transverse section through a ver- The number of the secondary lamellae 
tebra of Rana esculenta, magni- 


fied, increases with the age of the animal. 
GENE ea b. In the interior, in the form of a cylin- 
Ch Chorda dorsalis. ; 
Ch! Sheath of chorda dorsalis. der, is the remnant of the chorda dorsalis. 


0 Compact bone on the upper Tt consists of a double sheath (C#’) and 

pegs - contents (Ch) composed of chorda-cells. 
e. Immediately around the persistent por- 
tion of the chorda lies the central part of the 
vertebral body, formed by transformation 
of the vertebral cartilage and of the bases 
of the original cartilaginous arches. At 
each side of the chorda are large marrow- 
spaces (c), filled with cells, from which 
proceed narrower canals, winding in various 


Longitudinal section through the directions, and anastomosing freely with 
posterior half of the body of a 


Fig. 7. 


vertebra of Rana esculenta. one another both before and behind. Their 
a Cartilage of the head. walls are constituted partly of true bone 
€ Cancellous bone. 3 2 
o Shell of compact bone. partly of cartilage. 


! Cf. Gegenbaur, (1) Uber Bau u. Entwicklung der Wirbelsäule bei Amphibien 
überhaupt u. beim Frosch insbesondere. Abhand. d. Naturforsch. Gesell. zu Halle, 
vol. vi, 1861; (2) Untersuch. zur vergleich. Anat. d. Wirbelsäule bei Amphibien 
u. Rept., Leipzig, 1862. As regards the adult animal I can bear out Gegenbaur’s 
observations. The scope and limits of this book forbid me to go further into the : 
developmental history. 


THE 


V. 


SKULL. 


Tue UrosryLe (Figs. 


8 and g). 


The urostyle is a long, median, rod-like bone, which projects back- 
wards, midway between the two hip-bones, and terminates over the 


anus. 


The anterior end (Fig. 8 a) is the thicker and broader part 


of the bone, and has two articular depressions (Fig. 9) for articula- 


tion with the two facets of the ninth vertebra. 


The hinder end 


is pointed and cylindrical, and terminates in a cartilage, which 


is fixed in the tubular end of the 
bone. The middle portion is almost 
cylindrical, and has a groove along the 
ventral surface which gradually becomes 
less marked behind. The dorsal surface 
bears a ridge (Figs. 8 and g s), which is 
high and thick in front, becomes sharper 
and less prominent as it proceeds 
backwards, and gradually disappears 
towards the hinder third of the bone, 
so that in transverse section the an- 


Fig. 9. 
. 


Dr 


c 
Urostyle of Ranu 
esculenta, seen 
from the side, 
twice nat. size. 


¢ Ventral border. 

c.v. Canal. verte- 
bralis. 

s Dorsal  ridge 
(pr. spinos. ). 


terior two-thirds of the bone appear triangular, 
with a ventral and two lateral surfaces: while the 
hinder third is cylindrical. The anterior portion 
of the bone contains a canal, canalis vertebralis 
(Fig. 9 ¢.v.), which is a contimuation of the verte- 
bral canal, along which the hindermost spinal nerves 
pass. On each side of the anterior portion of the 
urostyle are small apertures (Fig. 8 ¢.c.), which lead 
into canals (canales coccygei), which open into the 
vertebral canal, and through which the coccygeal 
nerves pass. In front of these openings and partly 
overhanging them are small triangular projections 
(Fig. 8) (processus transversari) : these, however, are 
not constant, and are more often found in R. eseu- « 
lenta than in À. temporaria, in which latter species 
the openings are smaller. 


Urostyle of Rana 
esculenta, seen 
from the side, 
twice nat. size. 
A bristle is 
passed through 
the canal. vert. 
andoutthrough 
the canal. coc- 
cyg. of the right 
side. 
Anterior ex- 
tremity. 
c.c, Canal. coceyg. 
s Dorsal ridge 
(pr. spinos. ). 


i HE, SoU EE: 


The flat form of the frog’s head, as in batrachians generally, 
depends upon the wide separation of the jaw-bones of the two 
sides, and on the large size of the orbital cavities and the horizontal 


29 THE BONES AND JOINTS. 


direction of their floors. The outer circumference of the head 
forms a parabolic frame (Figs. 10 and 11), composed of the 
maxillary (#), premaxillary (2), and quadratojugal bones (7). In the 
middle of this curved framework lies the elongated prismatic 
cranium. Anteriorly, this is attached to the fore-part of the frame 
by means of the cartilaginous skeleton of the organs of smell 
(Fig. 11e); posteriorly, it widens out into two transverse arms ( p), 
which contain the organs of hearing. From this base, on either 
side, a bony strut, composed of the posterior arms of the squamosal 
(¢’) and of the pterygoid bones, passes backwards to the hinder end 


Skull of Rana esculenta, seen from above, Skull of Rana esculenta, seen from below, 
; twice radar size. twice natural size. 

e  Sphenethmoid. €  Cartilaginous wall of skull. 

Jn Nasal. e Sphenethmoid. 

Jp. Fronte-parietal. e’ Cartilaginous skeleton of nose. 

à Premaxillary. i Stylo-hyoid. 

j  Quadrato-jugal. ÿ  Premaxillary. 

m Maxillary. m Maxillary. 

o  Exoccipital. m’ Quadrate tract. 

op Opisthotic. 0 Exoccipital. 

p  Prootic. DIRE rootic. 

pt Pterygoid. p’ Anterior arm of prootic (ala magna autt.), 

pl’ Posterior limb of pterygoid. 3 p" Trigeminal foramen. 

t  Squamosal. pl Palatine. 

Posterior arm of the same. pt Pterygoid. 


pt’ Posterior arm of pterygoid. 

s.  Parasphenoid. 

v  Vomer. 
of the frame. The anterior arm of the squamosal bone (¢) does 
not quite reach the framework, but is attached to it by ligament 
alone. Between the last-named arm posteriorly, the cranium on the 
inner side, and the maxillary frame-work laterally, is a large space : 
representing the orbital and temporal fossae of human anatomy. 


THE SKULL. 23 


A. THE CRANIUM. 


The cranium of the frog is a prismatic tube, wide behind, narrow 
in front, and formed in great part of cartilage (Figs. 15 and 17). Our 
indigenous species are characteristically distinguished from one 
another by peculiarities in the form of the cranium. In 2, esculenta 
it is long and narrow, in À. temporaria short and wide. The superior 
surface in the former is markedly concave, while in the latter it is 
flat, and in ZX. oxyrhinus arched. These differences are readily 
recognised in the living animal. 


The Bones of the Cranium. 


1. The exoccipital bones, ossa occipitalia lateralia, Cuvier 
(Bios: 1O; 11,.12,14, 16 0). 
Cuvier, l.c., p.387, Pl. XXIV, bb.—Dugés, /. c., n.14.— Parker and Bet- 
tany, l.c., p. 166, exoccipitals. 

These paired bones form the hinder part of the cranium; they 
bound the foramen magnum, and articulate with the vertebral column. 
They are imbedded in the cartila- Fig. 12. 
ginous matrix of the skull, and are 
separated above by an unossified 
part of this matrix (occipitale 
superius, Dugès), which represents 
the tabular portion of human 
anatomy: below they are separated 
by a similar part (occipitale basi- a stapes. 
lare, Dugés) which represents the o men 
body of the occipital bone. They ec  Condyles of exoccipitals. 
therefore properly represent only À Heard 
the condylar portions (2 artes con- rf en which the jaw is attached. 
dyloideae) of the human occipital —¢ —Squamosal. 
bone. Each possesses a cartilaginous articular head, for articulation 
with the first vertebra: these converge below, and suriound the 
lower half of the circumference of the foramen magnum. This latter 
has, in À. esculenta, a transversely oval outline; in 2. temporaria, a. 
somewhat heart-shaped outline, with the apex directed upwards : 
in accordance with this the whole bone is wider than high in the 
first species; and in the latter it is higher than it is wide. From 
the upper and outer border of the foramen magnum on each side 


Skull of Rana esculenta, seen from behind, 
twice natural size. 


24 THE BONES AND JOINTS. 


a ridge runs obliquely outwards and downwards, in which lies 
the suture between this bone and the prootic bones. This bony 
ridge (processus mastoideus, autt.) is usually cartilaginous in 2. escu- 
lenta, even in old animals ; in À. temporaria, even in young speci- 
mens, it is bony. In the latter species the bones unite very early, 
while in the former they remain separated by the primitive carti- 
lage. Between this crest and the processus condyloideus there is a 
depression (fossa condyloidea), with a hole (foramen condyloideum) 
through which the vagus nerve leaves the crantum. The exoccipital 
take part in the formation of the labyrinth of the ear, as will be 
noticed later on. 

Articulation of the Exoccipital Bones with the Atlas. From the 
middle of the anterior surface of the body of the atlas a hgament 
arises, representing to a certain extent the (ig. suspensorium dentis, 
and attached to the basal portions of the exoccipital bones. 


2. The prootie bones, ossa petrosa, Cuvier (Figs. 10, 11, and 
12 p). 
Cuvier, rocher, /.c., p.388, Pl. XXIV, ee.—Dugés, n. 12, rupéo-ptéréal. 


—Stannius, ala temporalis— Meckel, Schädelstück des Schlä- 
fenbeins.—Parker and Bettany, L.c., prootic. 


These paired bones lie at the sides and in front of the exoccipital 
bones. As already explained, they remain in À. esculenta separated 
from these by cartilage, while in 2. temporaria they early enter into 
bony union with them; this is due to the complete ossification of 
the processus mastoideus in the latter species, as stated above. The 
prootics form the lateral expansions of the posterior part of the 
skull in which the organs of hearing are placed. The large cavity 
which contains the ear labyrinth is completed by the exoccipital : 
internally it opens freely into the skull, and externally on the 
posterior wall of the skull through the foramen ovale, which is 
formed by both these bones. The postero-lateral part of the prootic 
usually remains cartilaginous: at the side and in front of the 
Joramen ovale this cartilage is pierced by a small opening, through 
which passes the »ervus facialis or ramus tympanicus n. vagi (Volk- 
mann). At the side there is a process to which the suspensorium 
of the lower jaw is attached (Fig. 12 y): behind this is a hollow in 
which the auditory ossicles lie, and which may be designated fossa 
tympanica (Fig. 12 {). The anterior border of the bone forms the 


THE 


hinder and inner walls of the 
orbit. Here also is the tri- 
geminal foramen (Fig. 11 p”) 
through which the NV. ¢rigeminus 
and the several nerves for 
the muscles of the eye pass ; 
it represents the foramen ovale, 
for. rotundum, and the fissura 
orbitalis superior (sphenoidal 
fissure) of the human sphenoid 
bone. The foramen is some- 
times, especially in young 
animals, only a notch, which is 
completed by cartilage. On 
account of the relation of this 
part (Fig. 11 p’) of the bone 
to the nerves which pierce 
it, the whole bone has been 
named by Stannius the a/a 
magna or temporalis of the 
sphenoid; it has been also 
looked upon as a bone which 
contains these elements, as by 
Dugès, who on this account 
calls it rupéo-ptéréal. 


SKULL. 


25 


Skull of Rana esculenta, seen from below, twice 


c 


natural size. 
Cartilaginous wall of skull. 
Sphenethmoid, 
Cartilaginous nasal skeleton. 
Stylo-hyoid. 
Premaxillary. 
Maxillary. 
Quadrate tract. 
Exoccipital. 
Prootic. 
Anterior arm of prootic. 
Trigeminal foramen. 
Palatine. 
Anterior arm of pterygoid. 
Posterior arm of pterygoid. 
Parasphenoid. 
Vomer. 


Appendages of the Prootie Bones. 


1. The styloid cartilage. From the cartilaginous portion of the 
prootic the styloid cartilage runs downwards, backwards, and 
inwards, and is continued directly into the anterior cornu of the 
hyoid bone (Figs. 11 4’ and 12 4). 


2. The auditory ossicles. 


a. A thick cartilaginous disc, the operculum (Fig. 12 a), 


closes the foramen ovale. 


6. To the operculum is attached a bony, club-shaped piece, 
the columella auris (Fig. 12 a’), which has at its inner, thicker 
end a cartilaginous epiphysis, the interstapedial; it lies 
transversely with the apex directed outwards, and this longer 
portion is the mediostapedial. 

c. To the apex of the mediostapedial is attached, at an 


26 THE BONES AND JOINTS. 


obtuse angle, the third cartilaginous piece, the extra- 
stapedial (Fig. 12 4”). It is attached to the tympanic 
membrane, and by its upper portion is fastened to the 
cartilaginous tympanic ring by a smaller piece, the supra- 
stapedial. 

3. The tympanic ring (annulus tympanicus) is an annular cartila- 
ginous frame; or more exactly, has the shape of a short, truncated 
cone, as it narrows towards the middle line: it is attached to the 
squamosal bone. (See Organ of hearing.) | 


3. The parasphenoid, os sphenoideum, Cuvier (Figs. 11 and 163). 


Cuvier, l.c., p. 388, Pl. XXIV, d.—Dugés, n. 8.—Meckel, Theil des 
Grundbeins.—Parker and Bettany, l.c., parasphenoid. 

A large portion of the base of the cranium is taken up by this 
cruciform bone. Of the two longitudinal median processes, the 
posterior is by far the shorter, and lies in front of and partly 
below the cartilaginous os occipitale basilare. The anterior longer 
longitudinal arm closes in the greater part of the cranium from 
below, and articulates by its outer edges with that part of the 
prootic bones often described as the alae magnae, and also with the 
cartilage lying in front, which forms the greater part of the lateral 
walls of the cranium. The anterior extremity of the bone articulates 
with the palatine bones. The transverse arms lie on the under 
surface of the exoccipitals and of the prootics. 

The greater width of the cranium in R. temporaria is associated 
with the greater relative width of the anterior arm of this bone. 


4. The fronto-parietal bones, ossa fronto-parietalia, Cuvier 
(Figs. 10 and 14 fp). 


Cuvier, /.c., p. 387, Pl. XXIV, c.c.—Dugés, n.1.—Parker and Bettany, 
l.c., fronto-parietal. 


These are a pair of somewhat long, flat bones, which form the 
principal part of the upper wall or roof of the cranium, and cover 
in superiorly the cartilaginous cranium, which is here, in great 
part, persistent. They are united in the middle line by the sagittal 
suture; posteriorly they articulate with the exoccipital and prootic 
bones ; anteriorly with the sphenethmoid, which they overlap like 
tiles. The outer margin of each bone is bent somewhat down- 
wards (Fig. 16 fp), and between it and the parasphenoid there is a 
space in the wall of the cranium which is closed in by cartilage and 
connective tissue only. 


THE SKULL. Sa 


These bones are narrower in 2. escu/enta, and along the sagittal 
suture are depressed into a groove: where the superior surface bends 
down to become lateral the edges are much more prominent. In 
R. temporaria the bones are broader and flat or even somewhat arched. 
The latter condition is still more marked in ZX. oxyrhinus. 


5. The sphenethmoid, os ethmoideum (Figs. 10, 11, 14, and 
102). 
Cuvier, os en ceinture, /.¢., p.387, Pl. XXIV,a.—Dugès, n.15.—Rathke, 
anterior or sphenoidal wing (Vortr. z. vergl. Anat. d. Wirbelthiere, 
Leipzig, 1862, p. 42).—Meckel, Riechbein, L.c., p. 502.—Parker 
and Bettany, /.c., ethmoid. 

The long tubular cranium is completed anteriorly by a single 
bone, which forms at once the roof, floor, and lateral walls. It is 
consequently more or less ring-shaped, on which account it has been 
named ‘os en ceinture? by Cuvier. Only the posterior portion is 
annular, however : the anterior portion forms a double canal, with a 
median partition, for the passage of the nerves of smell, and as these 
canals are widened out anteriorly, this part of the bone helps to 
complete the nasal cavities, which, however, are bounded for the 
most part by cartilage, as described below. In some species of 
frogs (as for example À. occellata, Rathke) this cartilage is partly 
ossified. 

The sphenethmoid has on each side a small bony canal, running 
forwards and inwards, through which the ramus nasalis of the first 
division of the trigeminal nerve passes. 


44 


The cartilaginous skeleton of the nose (Figs.14 and 16%, n,n’, 
n°”). The anterior borders of the funnel-shaped cavities of the sphen- 
ethmoid pass into cartilage, which forms two capsules, separated from 
each other by a median cartilaginous septum, and opening laterally. 
We can distinguish, (a) a cartilaginous septum, forming a continu- 
ation of the bony one; (4) the floor of the nasal cavity, narrower 
behind, wider in front ; (c) a roof somewhat narrower than the floor. 
The floor and roof are united in front by an arched surface. From 
this cartilaginous capsule various processes project, which unite it to 
other portions of the facial skeleton : firstly, from the most posterior 
portion of the capsule there passes transversely outwards a bar of 
cartilage (sz), which, widening, becomes continuous with the carti- 
lage (sp”) forming the basis of the anterior arm of the pterygoid 
bone. From the anterior angle a cartilaginous process passes out- 
wards (Figs. 14, 16 ”), which is attached to a projection on the 


28 THE BONES AND JOINTS. 


anterior end of the maxillary bone; from the same spot a horn- 
shaped cartilaginous process (x, x”) curves round backwards and 
towards the middle line. This projection bounds the nasal cavity 
externally, sending off 
a free process (77) 
on the way, and ends 
with a double point on 
the roof of the carti- 
laginous nasal cavity 
(#7). On the floor of 
the nasal capsule, on 
either side, is a knob- 
shaped cartilaginous 
eminence, running’ 
from behind, forwards 
and outwards; this may 
be regarded as an in- 
dication of a turbinated 
bone. From the an- 
terior wall there passes 
into each nasal cavity 
an almost horizontal, 
partly ossified plate 
(c.n.),ending posteriorly 


Cartilaginous basis of the skull of Rana esculenta, from above, 
twice natural size. Cartilage shown by stippling. 


a.n. Wings of nasal cartilage. p. Prootic. 

en, Concha narium. pt Anteriorarm of pterygoid. yn a free pointed bor- 

e Sphenethmoid. pt’ Posterior arm of ptery- 

ff’ Foramina of cranium. goid. der. These are the, 

Jn Nasal. s’ Cartilaginous cranium. Ringe x > 

fp Fronto-parietal. sp Cartilage of suspensorium. cornets of Dugés (2. Ces 

i Premaxillary. sp’ Cartilage under the squa- D, 12, Pl. if. Figs. Tie 

J Quadrato-jugal, mosal. 

m Maxillary. sp” Cartilage under the ptery- 5), who correctly re- 

n,sn Cartilaginous nasal skele- goid. à 2 
FES Anterior à «dp the garded them as tur- 

n', a’, n! Processes of the À Middle } SA binated bones. Cuvier 
cartilage. t8 Posterior P 

o Exoccipital bones. described them as rudi- 


mentary nasal bones?. 
The alar cartilages of the nose have still to be described. They 
are (4.n.) shell-shaped cartilages, hollowed out on the inner sides and 


* Cuvier (Ossem. fossil., V, 2. 388) says that these little bones are fixed outside 
the nasal cavity, so that we may suppose that he confounded them with the 
nasal cartilages found in this situation. Dugès correctly indicates their position 
to be inside of the nasal capsule. Meckel (Vergl. Anat. IT, 504) also regards 
them as nasal bones. Bruch (Wiirzb. naturwiss. Zeitschrift, vol. II, 1861, p. 213) 
could not find them in any frog-skull, doubtless because he did not look inside the nasal 
capsules. 


THE SKULL. 


decreasing in width from before backwards. 


attached by their anterior broader ends to 
the tips of the projecting portions of the 
premaxillary bones, and are so arranged 
as to bound the lateral margins of the 
nasal apertures, which they overlap. 


6. The cartilaginous basis of the 
skull, Primordial cranium (Figs. 14, 16). 


a. If the fronto-parietals be removed, 
(Figs. 14, 16), a cartilage (s’) is found 
which partially closes the cranial cavity, 
and which is usually perforated on either 
side by a foramen (f”). 
More anteriorly in the 
median line is found a 
space (f) which ex- 
tends to the spheneth- 
moid bone, and is only 
closed by connective 
tissue: posteriorly the 
cartilage extends be- 
tween the exoccipitals 
as far as the foramen 
magnum, representing 
theosoceipitale superius. 

b. The base of the 
cranium is(Fig.16)also 
partly cartilaginous. If 
the parasphenoid (s) 
be removed we find ¢ Cartilage of prootic. 
above it a cartilage (s’) ¢ Sphenethmoid. 


29 


They are movably 


Fig. 15. 


n an 


m 


Nasal cartilages of frog, front 

view. 

an Concha narium, 

~  Premaxillary bones. 

Ascending process of same. 

Upper jaw. 

Lower jaw. 

n Olfactory capsule. 


Mo. 16 1 4 
5 a 


Cartilaginous skull of Rana esculenta, from below, twice 
natural size. Cartilage shown by stippling. 


pt 
pt 


Pterygoid. 


Articular surface for 


; Jp Fronto-parietal. pterygoid. 
which passes back- i  Premaxillary. x Optic foramen. 
J  Quadrato-jugal. 7’ Foramen for N. abducens. 
wards between the ex- m Maxillary. s  Parasphenoïd., 
oc cipital g an d exten ds n,sn Cartilaginous nasal skele-  $’  Cartilaginous cranium. 
2 ton. sp Cartilage of suspensorium. 
as far back as the 7,2", w”, n’” Processes of sp’ Cartilage under squa- 
7 : nasal cartilage. mosal. 
foramen MAGNUNGE : it o _Exoccipital. sp” Cartilage under  ptery- 
corresponds to the os ?, Prootic. ie 
pl Palatine. v Vomer, 


occipitale basilare. 


ce. The sides of the cranium are formed almost entirely of car- 


30 THE BONES AND JOINTS. 


tilage. This cartilage fills the space bounded by the nasals above, 
the parasphenoid below, the so-called a/a magna of the prootic bone 
behind, and the sphenethmoid in front ; and has in its posterior part 
an aperture (7) through which passes the xervus opticus, and below 
this a smaller one (7’) for the xervus abducens. The extent of the 
cartilage in the antero-posterior direction is greater in ZX. esculenta 
than in À. temporaria, or in other words the sphenethmoid stretches 
further back in the latter than in the former. 


B. Tue Bones OF THE FACE. 


Fie. 1%. The Suspensorium. 


7. The squamosal 
bones, ossa tympanica, 
Cuvier (Figs. ro, 14 7). 

Cuvier, oss. foss., V, 2. 

390, Pl. XXIV, Figs. 1, 

2n.—Dugès, temporo- 

mastoidien, n. 10. — 

Meckel, Articular part 

of temporal. — Hall- 

mann and others, quad- 


rate-bone. — Parker 
and Bettany, l.c., squa- 
mosal. 


The suspensorium, 
which forms the arti- 
culation between the 
cranium and the lower 


Cartilaginous basis of the skull of Rana esculenta, from above, 


twice natural size. Cartilage shown by stippling. Jaw, 1s T shaped, and 
a.n, Wings of nasal cartilage. 0  Exoccipital bones. consists of cartilage 
en. Concha narium. p. Prootic. red by b Of 
e  Sphenethmoïd, pt Anterior arm of pterygoid. covere RL CE 
ff’ Foramina of cranium, pt’ Posterior arm of pterygoid. the three arms of the 
Jn Nasal. s’ Cartilaginous cranium. 4 
Jp Fronto-parietal. sp Cartilage of suspensorium, T the anterior has a 
i Premaxillary. sp’ Cartilage under the squa- 2 5 5 
Fan Onadeaio unl 7 ess L free pointed extremity 
m Maxillary. sp” Cartilage under the ptery- (Fig. 14 11) at the 
n,sn Cartilaginous nasal skele- goid. 2 = 
ton. ft Anterior } arm of the postero-lateral margin 
n',n/!, n'” Processes of the car- {2 Middle Je Le a f the t Z bital 
tilage, #8 Posterior head 0 e temporo-orpita 


fossa: it forms a true 
processus zygomaticus, and is bound to the upper jaw by ligaments. 
In ZX. temporaria it is comparatively much shorter than in 2. 
esculenta. The posterior upper arm (/?) articulates with the prootic 


THE SKULL. 31 


bone: the third or lower arm (/), supported by a cartilage!, runs 
backwards and downwards to unite with the side of the broad 
hinder extremity of the quadrato-jugal bone. 

The cartilaginous basis! of the suspensorium (Fig. 17 sy, sp’) is a 
direct continuation of the cartilaginous basis of the cranium, and 
proceeds from it to the outer extremity of the prootic; from this 
point the cartilage runs backwards and divides into two branches ; 
of these, one (sy) retains the original course backwards and 
outwards towards the articulation of the lower jaw, and in con- 
junction with the quadrato-jugal (7) forms this joint. The other 
(sp”) is directed forwards along the anterior arm of the pterygoid 
bone ; it widens in front (sx), and becomes directly continuous with 
the cartilaginous strut described above as projecting from the 
hinder part of the cartilaginous olfactory capsule. 


8. The quadrato-jugal bones, ossa jugalia, Cuvier (Figs. 10, 


17, 19). 
Dugès, tympano-malléal, n. 11.—Cuvier, /. ¢., p. 399, Pl. XXIV, Figs. 
T, 2 0.—Hallmann, quadrato-jugal bone, /.c., p. 39.—Parker and 
Bettany, /. c., quadrato-jugal. 


This is a small process of bone, likened by Dugés to a comma, 
which rests by its posterior broader extremity on the cartilage of 
the mandibular arch 1, and forms with it a portion of the articular 
head for the lower jaw. The anterior extremity is pointed, directed 
forwards, and attached by ligament to the maxillary bone. 

9. The pterygoid bones, ossa pterygoidea (Figs. 10, 11,17, 19 pt). 
Cuvier, l.c., p. 389, Pl. XXIV, Figs. 1, 2 m m.—Dugés, n. 9.—Parker 
and Bettany, /.c., pterygoid bones. 

These bones, shaped like the Greek letter À, possess each three 
arms : of these the middle one is attached to the under surface of 
the prootic bone by a cartilaginous process (Fig. 18 sy); the hinder 
grooved arm lies upon the under surface of the cartilaginous suspen- 
sorial arch (Fig. 18 sp’); and the anterior arm (y/) runs forwards 
along the inner border of the anterior ramus of the suspensorium 
(sp’”’), in contact with the maxillary, palatine, and nasal bones. 

The cartilage just mentioned, by means of which the middle arm 
of the pterygoid is connected with the cranium (compare Fig. 18), 
proceeds from the cranial origin of the cartilaginous arch (sp), 
turns downwards and then forms a sort of articular head (cpt), 
which is articulated to an oval flat elevation of the prootic cartilage 

1 This cartilage is the quadrate cartilage of Parker ; others regard it as the upper 


end of the cartilaginous mandibular arch, of which Meckel’s cartilage is the lower 
distal part. 


32 


Origin of the suspensory cartilage 


(sp) from the skull, with attachment 
of the pterygoid ; front view. Car- 
tilage shown by stippling. 


cept Cartilaginous epiphyses of the 


J 


pt 
sp 


pterygoid bone, from the cartila- 
ginous suspensorium. 

Quadrato-jugal bone. 

Pterygoid bone. 

Origin of suspensorial cartilage 
from the skull. 


sp’ Hinder arm of same. 
sp” Anterior arm of same. 


m 


n,sn Cartilaginous nasal skele- s’ 


Fig. 10. 


Cartilaginous skull of Rana esculenta, from below, twice 
natural size, Cartilage shown by stippling. 


THE BONES AND JOINTS. 


by a movable joint. Externally the 
articular head curves somewhat abruptly 
into the bony substance (Fig. 18 pf) 
of the pterygoid bone. 


10. The maxillary bones, ossa 
maxillaria superiora, Cuvier (Figs. 10, 
11; 7,19 m): 

Cuvier, /.c., p. 389, Pl. XXIV, Figs. 1, 2kk. 
—Dugés, n. 4, maxillo-jugal. — Parker 
and Bettany, /.c., maxillary bones. 

These are elongated, curved bones, 
narrower behind, broader in front, and 
forming with the quadrato-jugals the 
bony support of the 
face. The superior 
surface 1s convex and 
directed outwards, the 


inferior surface 1s 
grooved and  bears 


teeth along the outer 
edge of this groove. 
From the upper and 
inner border of the 
anterior half of this 
bone a process (pro- 
cessus frontalis) passes 
upwards, which articu- 
lates with the nasal 
bone. The anterior ex- 
tremity of the bone 


Cartilage of prootic. pt Pterygoid. articulates with the 
Sphenethmoid. pt’ Articular surface for Il b th 
Fronto-parietal. pterygoid. premaxillary bone, the 
Premaxillary. r Optic foramen. sterior with the c d- 
Quadrato-jugal. yr’ Foramen for N. abducens. posterio with the 1e 
Maxillary. s  Parasphenoïd. rato-jugal. 


Cartilaginous cranium. 


The maxillary bone 


ton. sp Cartilage of suspensorium. 
n’,n’, W/!7, n1/7 Processes of sp’ Cartilage under squa- articulates at its an- 
nasal cartilage. mosal. ; À 7 
o  Exoccipital. sp” Cartilage under ptery- terior end (Fig - 19 % ) 
p  Prootic. goid. À: 
pl Palatine. »  Vomer. with a process of the 


of the nose. 


The 


cartilaginous capsule 


broad plate of cartilage (Fig. 19 7), under 


THE SKULL. 33 
” 
cover of the processus frontalis, connects the hindermost transverse 
portion of the nasal cartilage with the cartilage which runs forwards 
from the suspensorium upon the anterior arm of the pterygoid. 


11. The nasal bones, ossa fronto-nasalia, Dugès (Figs. 10,17 fn). 


Cuvier, frontale anterius, 1. c.,h.—Dugés, n. 2.—Meckel, nasal bone.— 
—Parker and Bettany, /. c., nasal bones. 


These flat, triangular bones, which rest upon the nasal cartilages 
(2), assist to bound the orbital cavities in front, and are connected 
by their external angles with the maxillary bone on either side ?, 


12. The premaxillary bones, ossa intermawillaria (Figs. 10, 11, 
7, 19%): j 
Cuvier, /.c., p. 388, Pl. XXIV, Figs. 1, 2 f f.—Dugés, n. 3.—Parker and 
Bettany, /.c., premaxillary bones. 

These two bones are united 
in the middle line : each consists 
of a tooth-supporting portion, 
which completes the maxillary 
arch, and an ascending’ pro- 
cess, to the apex of which the 
nasal cartilage is articulated 
by a movable joint (av). As 
muscles are attached to this 
process, it becomes a lever, 
by which movements are ef- 
fected. 1 


= Skull of Rana esculenta, seen from below, twice 
13. The palatine bones, ci ecg r 
ossa palatina (Figs. 19, 20 p/). © Cartilaginous wall of skull. 
P e ~ Sphenethmoid. 
Cuvier, /.c., P. 389, 11 XXIV, e"  Cartilaginous nasal skeleton. 


pre tat = # Stulo 101 
Figs. 1, 2 ii.— Dugès, n. 7.— h’ Stylo-hyoid. 
yee à i i Premavxillary. 


Parker and Bettany, l.c.,pala-  } Maxillary. 


tine bones. n’ Quadrate tract. 
; o  Exoccipital. 
Are two transverse bony »  Prootic. 
: . : ’ ee! p’ Anterior arm of prootic. 
bars, situated under the anterior  }» ‘Trigeminal foramen. 

portion of the sphenethmoid 1” Palatine. 

4 a pt Anterior arm of pterygoid. 
bone on either side: each ex- pt’ Posterior arm of pterygoid, 


s  Parasphenoid. 
tends outwards from the apex 4 Vomen 


of the parasphenoid to the maxillary bone, where this gives off its 
ascending: process to the nasal bone. 
! For os nasale, Cuvier (1. c., g), cornet (concha), Dugès, see cartilaginous nasal 


capsule, p. 27. 
D 


34 THE BONES AND JOINTS. 


14. The vomers, vomer (Figs. 19, 20 v). 
Cuvier, L.c., p. 389, Pl. XXIV, Figs. 1, 2 11.—Dugés, n. 6.— Parker 
and Bettany, /.c., vomer. 


A pair of flat bones, placed horizontally on the under surface of 
the cartilaginous nasal capsule in the triangular space between the 
palatine bone and the anterior portion of the arch of the jaw. They 
limit the outer border of the floor of this capsule, which lies in 
a groove on the dorsal surface of the bone. The outer border of 
each bone has three processes, and between them two notches; the 
hinder of these notches bounding the posterior nares. The inner 
borders of the two bones touch, and the under surface of each bears 
a transverse row of small, pointed teeth. 


15. The mandible, maxi//a inferior (Fig. 21). 
Cuvier, /.c., p. 398, Pl. XXIV, Figs. 1, 2 rst.—Duges, n. 16, 17, 18, 19.— 
Parker and Bettany, /.c., mandibular arch. 

The mandible consists of two bony arches united by hgament in 
the middle line, and each formed of four pieces. These are, (1) the 
angulosplenial, a 
strong, bony piece 
(Mig. 21 0, Bi, aay 
which forms the in- 
ferior and internal 
part of the lower 
jaw; below, it ex- 
tends posteriorly, as 
far as the articula- 
tion ; in front, it is 
attached to the den- 
tary. In the greater 
part of its length it 
has a groovedirected 
upwards and out- 
wards (C, 4), and 
above has à pro- 
cess which repre- 


A Mandible of Rana esculenta, from above, nat. size. 


A paver Viet of left side, \ ities Gate ek: sents the processus 
ngulosplenial, : 
1. Angulosplenial. coronoideus . (2) the 
2.  Dentary. 
3.  Mentomeckelian. dentary (4 2, B 
4, 4’ Meckel’s cartilage. 2), a bony lamella 


a. Rudimentary processus coronoideus. 3 
b. Groove for Meckel’s cartilage, which rests on the 


THE SKULL. 35 


outer surface of the anterior half of the angulosplenial, and articu- 
lates in front with Meckel’s cartilage; it is a thin, flat lamella of 
bone ; (3) in the groove of the angulosplenial is found a cartilage 
occupying its entire length (4 4, B 4), Meckel’s cartilage ; it is 
broader behind, and here forms the articular fossa of the lower jaw ; 
anteriorly it is covered by the dentary, and articulates with the 
(4) mentomeckelian (4 3, B 3) at its anterior end, which is bound to 
its fellow of the opposite side by ligaments, and unites the two 
halves of the lower jaw. 

The upper part of Meckel’s cartilage, which forms the joint with 
the suspensorium, must be regarded as the articu/are; to this also 
belongs the anterior, ossified portion of the mentomeckelian!; the 
dentary, which covers Meckel’s cartilage, must represent the os 
dentale* ; the first and largest bone, the angulosplenial, which lies 
on the inner side of the cartilage, must be considered as the os oper- 
culo-angulare, Dugès, for it contains the elements of these bones. 


16. The hyoid bone, os hyoideum (Fig. 22). 
Parker and Bettany, l.c., hyoid. 

This consists of a broad, thin, cartilaginous plate, with processes 
passing from it as represented in the figure. We distinguish in it :— 
(a) the body (/7), somewhat oblong, and 
wider in front than behind. From the 
anterior angles there projects on either side 
a blunt rounded process (/); from either 
posterior angle a more pointed process (/’). 
(b) The anterior cornua (77°) (cornua sty- 
loidea) project from the anterior border of 
the body, first in a forward direction, then 
in a curve backwards and upwards (compare 
Fig. 12), to unite with the cartilage of the 
prootic bone. Where the direction of these Hyoid of Rana esculenta, 

. twice nat, size. 
cornua is changed each sends off a short |, poay- 41 
: ody ; hh’ processes. 
blunt process. (ce) The posterior cornua  #’ Anterior horn. 
. \ 1 : H” Posterior horn. 
(cornua thyroidea) (H”) are bony rods which 
run from the hinder margin of the body, diverge posteriorly, and 
enclose the larynx. 


Fig. 22. 


1 Duges, os dentale. 2 Dugès, surangulaire, 


36 THE BONES AND JOINTS. 


III. THE STERNUM (Fig. 24 es, hs). 


Cuvier, L.c., p.401, Pl. XXIV, Fig. 31 e f.—Dugès, n. 27, 28.—Parker 
and Bettany, /.c., sternum. 

The bones of the sternum are in very close relationship with the 
shoulder-girdle, and some difference of opinion exists as to the rela- 
tions of the several parts. 

Fig. 23. The following parts must be regarded as undoubtedly 
belonging to the sternum :— 

1. An anterior part, consisting of a bony and a carti- 
laginous portion. 

a. The omosternum (Figs. 23, 24 ¢.s.) is a bony 
rod, wider behind, narrower in front, and supports 
4. The episternum (Fig. 24 es’), a semicircular 


Omosternum 4] on 1 i a f 
pepe secs plate of calcified cartilage, with a thin free border 
lenta, twice of unchanged hyaline cartilage. 
nat. size. : = 1 
ee 2. A posterior part, which also consists of a bony 
p Posterior and a cartilaginous portion. 

extremity. 


Fig. 24. 


Shoulder-girdle and sternum of Rana esculenta, twice nat. size, 
The scapula and suprascapula are turned outwards, 


c. Connecting cartilage. hs. Sternum proper 
cl. Clavicles and precoracoids. hs’ Xiphisternum#" 
co Coracoid. o Bone. Lu. 
es, Omosternum. 0! Calcified cartilage. - 
es’ Episternum. sc. Scapula. 


h  Hyaline cartilage. sc! Suprascapula. 


THE PECTORAL GIRDLE. Ot 


a. The sternum proper (Fig. 24/.s.), a rod of cartilage 
ensheathed in bone, broader in front and narrower behind. 
To its posterior extremity is attached 

é. The cartilaginous xiphisternum (Fig. 24 /s’), a plate, the 
shape of which is best understood by referring to Fig. 24, and 
the structure of which is similar to that of the episternum. 

3. The epicoracoids! lie between the episternum and the sternum 
proper: they are a pair of narrow cartilages, closely applied to 
each other and placed between the ventral ends of the precoracoids 
and coracoids, see p. 40. 


IV. THE BONES OF THE ANTERIOR EXTREMITY. 


A. BONES OF THE SHOULDER-GIRDLE. 


The shoulder-girdle of the frog (Fig. 25) consists of four bones, 
two in the upper or scapular portion, and two in the lower or 
coracoid portion. 


1. The scapular portion. 
a. The suprascapula, purs supra- 
scapularis scapulae, scapula superior 
s. omolita (Figs. 254, 26, 27). 
This forms the upper, thinner por- 
tion. It is trapezoid in shape, its 
narrowest, thickest, and lowest 
border articulating with the sca- 
pula. The remaining three borders 
are free; the posterior and supe- 
rior borders are very considerably 5, ugercirdle of the frog in transverse 
thinned out, the inferior surface section, diagrammatic. 


e Connecting cartilage. 


is curved towards the ventral ‘* 


ec’ Epicoracoids. 
surface. Only the thin upper and = vices 

; = 3 2 Humerus. 
hinder borders (44) are of hyaline + Scapula. 

til - tl 0 1 1l ti] Suprascapula. 

cartuage ; the middie portion (co) ss Articulation of these two. 
consists of calcified cartilage; the °% Vertebra. 
lateral part (0) and the anterior border (0°) of true bone. 


The bony part forms a thin plate striated both radially and 


1 Dugès, L.e., p. 61, regards the cartilaginous laminae as os episternale and proc. 
æiphoideus, and the two bones e.s. and h.s. (Fig. 24) as sternum. 


38 THE BONES AND JOINTS. 


concentrically with the margin. The anterior border (0’) is bent 
on itself so as to form a groove (Fig. 27). The dorsal surface 
of this bony plate is quite smooth, and covered only by periosteum ; 
the ventral surface, on the contrary, is for the most part covered 


Fig. 26. His 2/7 


Suprascapula of Rana esculenta, from above, Suprascapula of Rana esculenta, from below, 
twice nat, size. twice nat, size. 
co Calcified cartilage. co Calcified cartilage. 
h Hyaline cartilage. co’ Layer of calcified cartilage on the under surface 
o Bony portion. of the bone. 
o’ Anterior curved border. h Hyaline cartilage. 


o Bony portion. 

o’ Anterior curved border. 
by an even layer of calcified cartilage (Fig. 27 co’). This passes 
directly into the second portion of calcified cartilage (co); so that if 
the whole be dried, the thin hard lamina of bone can easily be split 
away from the underlying parchment-like cartilage. The layer of 
calcified cartilage is, however, not so complete that the suprascapula 
can be said to consist of calcified cartilage. 

b. The scapula (Figs. 255, 28, 29) is a long, flat, four-cornered 
plate of compact bone, contracted in the middle, and wider at either 
end. From above (Fig. 28 7) it descends to the shoulder-joint with a 
slight curvature, with the con- 
vexity directed outwards. The 
inferior or ventral border (Fig. 
28 m), which assists in the forma- 
tion of the shoulder-joint, is cleft 
into two processes, a ventral and 
a dorsal. This may be best seen 
by looking at the border of the 


Fig. 28. Fig. 29. 


Left scapula of Rana esculenta, 
from below, twice nat. size. Scapula 


seen 
a or nator. from behind, bone from behind or before (as 


= = ric - iy 
c.a. Cavitas articularis. twice nat. size. 


in Fig. 29). The lower ventral 


2 Outer border. c.a. Cav. articularis. a 
m Inner border. d. Dorsalprocess.  PTOCESS (I 19. 29 v) may be re- 
p  Posterior border. v Ventral process, 


garded as the acromion, or at 


THE PECTORAL GIRDLE. 39 


least as a rudiment of the acromion, 7. e., spina scapulae. The upper 
dorsal process evidently represents a rudimentary processus coracoi- 
deus. The anterior border (Fig. 28 a) is free, somewhat sharp, and 
slightly concave; the posterior (Fig. 28 y), also concave, is free 
externally ; while internally, where the division of the ventral border 
commences, it takes part in the formation of the articular cavity of 
the shoulder (Figs. 28 and 29 ¢.a.). 

Articulation with the suprascapula, The scapula consists of 
a shell of compact bony tissue and an inner portion of cancellous 
tissue ; this latter passes, at the boundary between this bone and the 
suprascapula, through an intermediate laver of calcified cartilage, 
which is directly continuous with the cartilage of the suprascapula. 
The compact superficial layer ceases where the calcified cartilage 
begins, and the periosteum of the scapula passes directly into the 
perichondrium of the suprascapula. 


2. The ventral portion of the shoulder-girdle consists of three 
parts, which lie one behind the other. 

a. The larger and posterior bone, the coracoid (Figs. 24 co, 30), 
is contracted in the middle, and expanded 
at either end, especially at the sternal end. 
The inner half is flattened from above down- 
wards ; externally it becomes more cylindrical. 
The anterior and posterior borders are markedly 
concave; the outer border (Fig. 30 /) ar- 
ticulates by means of a cartilage with the 
proc. coracoideus of the scapula; the inner bor- 
der (7) is separated from its fellow of the 
opposite side by the epicoracoids. This mner |, et JE 
border is so broad, that it almost touches the size. 
inner end of the clavicle (Fig. 24 c/.). A° From pen 
coracoid foramen is thus formed between the 7 Outer extremity. 
two bones, similar to the foramen ovale of the ™ "7 extremity 


pelvis. 
b. The small anterior bones of the ventral portion of the shoulder- 
girdle (Figs. 24 cl., 31), I, like Cuvier and Fig. 31. 


others, regard as clavicles. Dugès (n. 33) | ee 
names them ‘ acromial” Each bone is nar- RE 4 


rower than the coracoid, smaller internally Th Sern 
av e Py 


(m), broader externally (/), and articulates by twice nat. size. 
: 5 9 Be 4 Outer extremity, 
this broader end with the cartilage uniting the — m Inner extremity. 


4() THE BONES 


Right shoulder-girdle of Rana esculenta, from 


above. 
ca Cay. articularis. co Coracoid. 
ce Cartilage. se Scapula. 
cl Clavicle. sc! Suprascapula. 


AND JOINTS. 


dorsal and ventral portions ; 
the inner extremity rests upon 
the epicoracoid. The clavicle is 
grooved on its superior and 
posterior surfaces in almost its 
whole length; the groove widens 
externally (/), and contains 

c. The precoracoid (Fig. 
34c/), aslender bar of cartilage, 
connecting the anterior edge of 
the scapula with the sternum. 


Cartilages of the shoulder-girdle (Figs. 24, 32, 34). A car- 
tilage (c), described by Dugés as the ‘paraglénal connects the 
scapula with the coracoid, and converts the notch between the two 
processes (s and v) on the inner border of the scapula into an 
aperture opening posteriorly into the glenoid cavity, and which is 


filled up by the lining cartilage. 


This cartilage connects the two 


processes with the coracoid; being thicker between this and the 
proc. coracoideus, + takes an important share in the formation of 


Hinder border of the sca- 
pula and coracoid, with 
the connecting cartilage 
and shoulder-joint, twice 


i 
e 
c’ 


Clavicular cartilage of a young specimen of Rana esculenta, 


enlarged to the adult size, 


Connecting cartilage. 

Epicoracoids. 

Ligament between the two cartilages. 
cl Clavicle. 


nat. size. cl’ Clavicle and precoracoid. 
ce Connecting cartilage, co Coracoid. 
d Dorsal process. co’ Cartilage of same, 
co Coracoid, es Omosternum, 
se Scapula. hs Sternum proper. 
v Ventral process. 


the floor of the glenoid cavity. At the outer extremity of the 
clavicle the cartilage projects and is then continued in the groove 


THE FORE-LIMB. 41 


on this bone towards the middle line (Figs. 32, 34), where it 
widens out, and is united by its external margin with the sternum, 
thus forming the precoracoid as already described, see p. 40. 
These connections are best seen in young animals, as is shown in 
Fig. 34. 

The clavicle (c/) is of ossifying cartilage ; the cartilage (c), the 
epicoracoid, is very large, and hyaline, and at ¢/ runs directly into 
the epicoracoids, which are here united mesially by ligament. In 
the fully developed animal the whole of the epicoracoid changes to 
calcified cartilage, as also does the precoracoid lying in the groove 
of the clavicle. 


B. Bones or THE Fore Lime. 


1. The arm has but one bone. 
The humerus, os Aumeri (Figs. 35, 36, 37). The shaft of the 
humerus is, on the whole, cylindrical, the middle part being the 
Fig. 35. Fig. 36. Fig. 37. 


c’ 

Humerus of Rana es- Humerus of Rana es- Humerus of Rana 
culenta, female, seen culenta, male, seen esculenta, female, 
from below. from below. outer side. 

Figures twice natural size. 
e Anterior extremity. c’ Posterior extremity. ed Crista deltoidea. 


em Crista medialis. t trochlea. 


narrowest ; its dorsal surface is shghtly concave, the ventral surface 
convex. In the upper half the cylindrical form is indistinct, from 
the presence of a well-marked crest (evista de/toidea) upon the under 
or ventral surface. The hinder half of the bone has very different 


42 THE BONES AND JOINTS. 


shapes in the two sexes : in the female it remains cylindrical as far 
as the elbow-jomt; in the male, on the posterior surface, where 
the crista deltoidea ceases, a marked ridge (crista medialis) arises, 
which gradually winds inwards and terminates at the inner condyle. 
This sexual difference is found in all the three species described in 
the Introduction, and it would seem that this ridge increases in height 
during the pairing season. The muscle which arises from this process 
is the flexor carpi radialis (Fig. 74 Fc), and it attains, in the males, a 
very large size at the same period ; indeed, it is at its origi twice 
as broad as in the female.  Dugès! has incorrectly stated that 
this crésta is a peculiarity of Rana temporaria, and is wanting in 
Rana esculenta. Pouchet? first observed that it was a sexual dis- 
tinction. 

The anterior articular extremity presents a rounded head, which is 
somewhat flattened externally. The inferior ventral border is sharp, 
and developed into the above-mentioned bony crest (cvista deltoidea) ; 
the free border is arched and curved outwards. Above, on the 
outer surface of the head, is found an eminence which may be 
a rudimentary #wberc. maius. The inner half of the head is 
articular. 

The posterior articular extremity consists of a rounded head (c’), 
attached to the posterior extremity of the shaft; internal to this is 
a small ¢roch/ea (1), placed upon the inner condyle. The external 
condyle is but small. The head is embraced by these condyles. 
Upon the under surface, above the head, is the fossa cubitalis 
anterior. The structure of the two articular extremities of the hu- 
merus differs ; the upper, as in long bones generally (see page 16), 
consists of hyaline cartilage surrounded by calcified cartilage, which 
again is covered by hyaline articular cartilage ; the lower extremity 
is composed of spongy bone, with roundish marrow spaces, and for 
the most part covered by a layer of calcified cartilage. 

The shoulder-joint. The socket is formed by the posterior border 
of the scapula, by both the processes of that bone, the outer portion 
of the coracoid, and besides these by cartilage, which forms the 
articular surface already described (Fig. 33). In the macerated 
bone the floor of the socket opens dorsally into a fossa 
between the processes of the scapula (Fig. 32). This opening, in 
the natural condition, is closed by synovial membrane only; the 
cartilage covering the rest of the space being absent (the sac may 


DaLiCrs pt OS. 2 Compt. rend. vol. XXV, 1847, p. 761. 


THE FORE-LIMB. 43 


easily be inflated, either from the joint itself or through the opening). 
The margin of the socket consists of a /abrum, partly fibrous and 
partly cartilaginous, which is easily removed entire. The capsule, 
which is attached beneath the caput humeri, arises from this. From 
the articular cartilage of the ventral margin of the socket, and from 
the adjacent part of the scapula, proceeds a strong band, which is 
inserted into the flattened outer surface of the head. 
2. The forearm. 

The radio-ulnar, os antibrachii (Fig. 38). The two bony 
elements of the forearm are fused into one, which, however, shows 
traces of its compound character. Of these two bones, 
that which forms the inferior (in man anterior) border 
is the radius, the other the ulna. The relative posi- 
tions of the bony elements are such that they ap- 
pear to be in a state of semi-pronation ; by this the 
thumb-border of the arm is directed downwards (in 
man forwards). The two bones so united form a 
flattened, tube-like bone, the grooved surfaces of 
which are directed inwards and outwards respectively ; 
the borders being dorsal and ventral. The shaft of 
the bone is narrower above, becoming gradually wider 
below. In the upper half, the groove showing the — Radioumar of 
line of junction of the two bony elements is 1° ish’ Sle 
searcely visible, and it appears as though this part  Znta,twicenat. 
consisted of ulna alone, the radius not reaching so, Rain 
far; below the groove is more marked. The upper ” Beat 
articular extremity appears to consist of an olecranon w Una. 
(Fig. 38 uw’) and a processus coronoideus (7), between eee LA 
which is the greater sigmoid cavity (cavitas sigmoidea major) for 
the processus cubitalis humert. A more careful examination shows 
this to be incorrect: the portion of the concave articular surface, 
which lies in the immediate neighbourhood of the ventral border, 
undoubtedly represents the articular surface of the capitulum radii, 
and the upper portion of the articular surface (at #’) belongs to the 
ulna and articulates with the ¢rochlea (Figs. 35, 36 ¢) of the 
humerus. The inner border of the upper extremity of the bone 
articulates with the groove ¢ of the humerus. The inferior 
extremity forms one of the usual cartilaginous epiphyses, enclosing 
the two bones. That part of the extremity corresponding with 
the radius is triangular and convex, it is prolonged upon the 
inner or under surface of the bone by means of a process; the 


44 THE BONES AND JOINTS. 


ulnar portion of the bone forms a capitulum. The structure of 
the inferior extremity is that of epiphyses in general, except that 
there are two medullary cavities in a common sheath of calcified 
cartilage; the anterior head consists of cancellous tissue, with a 
covering of calcified cartilage. 


Fig. 39. 3. Bones of the hand (fig. 39). 


Dugés, Pl. VIII, Figs. 37, 38: 39; 40, 41, 
42, 43, 52. 

a. Bones of the wrist, ossa carpi. 
These are arranged in two rows, proxi- 
mal and distal. The proximal or an- 
terior row has three bones, viz. : 

1. Os dunatum, the middle bone (Fig. 
39 /), Duges, n. 38, articulates with the 
At radial part of the articular surface of 
the radio-ulnar by a concave surface ; 

with the large bone of the second row 

(Ac) it articulates by means of a rounded 
head; and with the two other bones 
of this row, os naviculare (n) and pyra- 
midale ( p), with the former by a saddle- 
shaped surface, with the latter chiefly 
by ligament. The bone is irregularly 
cuboid ; the dorsal and palmar surfaces 
are non-articular. With Dugés I regard 
this bone as os /unatum; Mertens! re- 

( gards it as os naviculare. 
: . 

SILENCE) eth Reap eR at Os pyramidale (Fig. 39 p), Duges, 
esculenta, right side, dorsum, twice N. 37, articulates with the ulnar part 


DE 


j 
i 


ME of the posterior articular extremity of 
a Os antibrachii. à x 
he Os capitato-hamatum. the radio-ulnar. Anteriorly the bone 
L Os lunatum. ] £ t whicl RARE tl init 
ye sapere as a facet which receives the capitu- 
Os DANiCUIArS. Jum ulnae, and alongside this a small 
p Os pyramidale. à È 3 
r Radial portion of the radio-ulnar. flat surface which articulates with the 


4 Os multangulum majus or trapezium. , 1: P t : ] t tl : 
{Os multangulum minus or trapezvides. TAGIUS. osterlorly, Opposl e to Le 


* second row, it presents a long raised 


w Ulnar portion of the radio-ulnar. , 4 
1—V First to fifth fingers, the fifth only à à 

of os metacarpi, the second’and third articular surface 5 extending from the 
of two, fourth and fifth of three 


phalanges. dorsum to the palmar surface; and on 


1 Mertens, /.c. 


THE FORE-LIMB. 45 


the palmar aspect of the bone is a ridge running from before back- 
wards. Mertens names this bone os /unatum. 

3. Os naviculare (Fig. 39 x), Dugès, n. 39. The third bone 
of the first row does not articulate with the bones of the forearm. 
It is connected with the os /unatum by a saddle-shaped surface, pos- 
teriorly with the os capitatum by means of a concave surface. On 
the inner surface is a small concave articular facet for the os mu/t- 
angulum minus or trapezoides (Fig. 39 ¢’). The convex palmar 
surface of the bone articulates with the os multangulum majus (t); the 
radial side is non-articular, and with the os /unalum forms a ridge 
directed forwards. Mertens names this bone os ¢riquetrum. It is 
evident, however, that if the arrangement in man obtains as a 
standard, the nomenclature of Dugès, which I have here used, is 
correct; but the os naviculare is no longer in contact with the 
articular surface of the os antibrachit. 

The second or distal row also consists of three bones :— : 

4. Os capitato-hamatum (Fig. 39 4c), Dugès, n. 40, 41, 42, 
corresponds with the os capitatum and hamatum', which are here 
fused together. It is the largest bone, and articulates with all three 
bones of the first row; it is crescentic, with the concavity directed 
posteriorly, and on the convex surface has three facets for the three 
outer ossa melacarpi. 

5. Os multangulum minus, s. trapezoides (Fig. 39 t’), Dugès, 
n. 43, is a small bone lying next to the foregoing; it articulates 
with the os metacarpi IT, and anteriorly with the os naviculare. 
Dugès considers it to be the os trapezium. 

6. Os multangulum majus, s. trapezium (Fig. 39 t), is a small 
bone, which is placed on the convex palmar auricular side of the 
os naviculare. Dugés regards this bone as 0s metacarpi pollicis 
(Dugès, n. 44), Mertens as mu/tangulum minus. It appears to me 
that the interpretation here given is justified, because it articulates 
with the rudiment of the thumb, and as it possesses no resemblance 
to a long bone it cannot be regarded as an 0s metacarpi. 

Structure of the carpal bones. All the carpal bones consist 
of calcified cartilage, though variations due to age occur in the 
amount of the deposit. 

Wrist joint. As stated above, the os /unatum and os pyramidale are 
articulated with the forearm, In addition to the capsules uniting 
the parts, there are strengthening ligaments, two of which require 
special mention. One of these arises from the palmar surface of 


* Dugès thinks that os trapezoides is also included, 


46 THE BONES AND JOINTS. 


the posterior extremity of the ulna, and passes to the sharp palmar 
ridge of the os pyramidale, where it is attached, and is inserted into 
the os capitato-hamatum ; the second ligament passes in a similar 
manner on the palmar surface from the radius to the os naviculare. 
Between the two ligaments there is on the volar surface a deep 


excavation. 


IDE 


Bones of the forearm and hand of Rana 
esculenta, right side, dorsum, twice nat, 
size, 

a Radio-ulnar. 

he Os capitato-hamatum. 

& Os lunatum. 

m Ossa metacarpi. 

n Os naviculare. 

p Os pyramidale. 

yr Radial portion of the radio-ulnar. 

Osmultangulum maius or trapezium. 

# Osmultangulum minus or trapezoides, 

« Ulnar portion of the radio-ulnar. 

I-V First to fifth fingers, the first only 
of a metacarpal, the second and third 
of two, fourth and fifth of three 
phalanges, 


Movements of the hand. The two 
bones of the forearm being firmly 
united, pronation and supination, as 
in man, are impossible. The normal 
position, as already remarked (see radio- 
ulnar), is that of semi-pronation (com- 
pare Figs. 2 and 74). Ifthe animal 
be in its natural posture, with the arm 
bent at the elbow (Fig. 1), it can touch 
the ground with the ulnar border only ; 
but when the whole surface of the hand 
rests upon the ground, the action is 
brought about as follows: the plane of 
the carpus is in extension parallel with 
that of the forearm; in flexion, almost 
at right-angles with that plane (Fig. 
74). The os dunatum glides on the pro- 
longation of the articular surface on the 
inner palmar surface of the radius, 
while the os pyramidale is held firmly 
by the ligament just described. The 
hand follows the movement of the os 
lunatum, and at the same time the three 
outer ossa metacarpi gliding with it in- 
wards, the fingers of the hand turn 
inwards. 

b. The Bones of the metacarpus, ossa 
metacarpi (Fig. 40m). Of these there 
are five: the second to the fifth are of 
about equal length; the first, forming 
the rudiment of the thumb, hidden 
beneath the skin, is much shorter. 
This metacarpal bone of the thumb is 
regarded by Dugés and others as the 


first phalanx. My reason for describing it as a metacarpal has 


THE PELVIC GIRDLE. 47 


already been given. This bone also presents differences in the two 
sexes. Meckel’s! observation that it exists only in the male is 
incorrect ; it is a large, broad and sickle-shaped mass of calcified 
cartilage or even true bone, while in the female it is simply a small 
cartilaginous rod ; as this almost entirely disappears in dried speci- 
mens, Meckel’s statement is explained. The second finger has in 
the frog assumed the functions of the thumb, and, in the males, in 
the breeding season swells and undergoes an essential alteration of 
structure. The metacarpal of this finger also displays differences 
in the sexes, being in the male stronger, broader, and on the inner 
side provided with a spine-like prolongation, for the tendon of the 
abductor digiti II (pollicis) longus, which attains an unusual de- 
velopment during the breeding season. The remaining metacarpal 
bones, the third, fourth, and fifth, are of similar form, the last 
being provided with a tubercle. The anterior articular extremities 
are rather broad and concave, and the posterior have rounded 
heads. i 

e. The phalanges, phalanges digitorum. The hand has four fingers 
and the rudiment of a fifth, which latter is completely hidden under 
the skin, and as already explained, consists of a metacarpal only. 
Of the four fingers, the fourth is the longest, the third the shortest, 
the second and fifth of intermediate and about equal length; the 
fourth and fifth fingers have each three phalanges, the second and 
third have each two. Their shape is not unlike that of the human 
phalanges. 


V. THE BONES OF THE HINDER EXTREMITY. 


A. Bones or tun Pervic Girpie (Fig. 41). 


The pelvis has a characteristic V-shape, the pubic and ischiatie 
bones of the two sides together forming a vertical plate (a p), 
which divides anteriorly into the two iliac bones (7/). The pubic 
and ischiatic bones being united by their median surfaces, one can 
only speak of the pelvic cavity as the space between the two: 
ilia. < 

1. The ilia, ossa i/ii (Fig. 4277). In these a broader part or 


er us 464. 


48 THE BONES AND JOINTS. 


body can be distinguished, which takes part in the formation of the 
acetabulum (a). The hinder and broadest part of the bone is joined 
to the corresponding portion of its fellow by ligament ; anteriorly the 
two diverge, bounding a cone-shaped cavity, the pelvis. The suture, 
by which the body of the ilac bone is united with the ischiatic 
and pubic bones, runs from above downwards through the middle of 
the acetabulum (Fig. 42, 
from ÿ through the ace- 
tabulum to is). Inferiorly 
and in front the united 
ilia form a prominence 
(s), which represents the 
symphysis oss. pub. of 
man. The expanded por- 
tions of the ilium rest 
directly over the articu- 
lar cavity by means of 
a somewhat constricted 
Pelvisof Rana esculenta, Part or root. The ala is 
from below, nat. size. a sabre-like bone, with 


Fig. 42. 


Geer Dulium, the sharper, more convex 
il Iliac bone. ames 
p Pubic bone. border directed upwards ; 


the more concave, thicker 
border downwards. The two surfaces, 
of which the inner is grooved, are 
directed respectively inwards and outwards. 
The broader part of the blade springs 
directly from the neck or root (at 2/’), and 
at this end of the sharp convex border 
is a process, process. sup., from which 


is 


Pelvis of Rana esculenta, left side, 


twice nat, size. the tendon of the mm. vastus externus arises. 
a Acetabulum. : a + 
Wpiig gence border. The anterior end of the blade is a hol- 
ee et BO low eylinder, containing cartilage, mov- 
il! Superior process. HAE j 
is Ischium. ably articulated to the transverse process 
is’ Tuber ischii. 
obit of the last vertebra or sacrum. 
M de Pt iar 2. The ischia, ossa ischii (is), are irre- 
v Lower border of same, À : 


cular, four-cornered plates of bone, united 
together by the whole extent of their inner surfaces. _ The vertical 
plate formed by the union of the two bones takes only a very 
small share in the formation of the articular cavity. Above, it has 
a somewhat sharp border, continued with the ium into a process 


THE HIND-LIMB. 


(is) corresponding with the united fuera ischu ; 
the hinder border, which is united below with the 
pubic cartilage, is curved. 

8. The pubes, os pubis (Figs. 41, 42, 43 D). 
Ossified pubic bones do not exist; even in old 
animals they are composed of calcified cartilage. 
Each is a triangular cartilage, wedged between 
the ilium and ischium, but also taking part 
in the formation of the acetabulum. The pubes 
of opposite sides are, as shown in section in 
Fig. 43, united by ligaments in the median 
plane. 


B. Boxes or tHE Hinp-Limp. 
1. The thigh. 


Horizontal section 
through the iliac, 
pubic, and ischiatic 
bones. 
a Acetabulum. 
il Iium. 
is Ischium. 
p Pubic cartilage. 
s Ligaments which 
unite the bones of 
opposite sides. 


The femur, os femoris (Fig. 44). The shaft is cylindrical, 


with a slight double or S-shaped curve. In the 
anterior portion the convexity is directed upwards, 
in the two hinder thirds downwards. Towards 
the hinder extremity it is flattened from above 
downwards. The anterior extremity is a rounded 
articular head placed directly on the shaft like 
that of the humerus. This head is somewhat flat- 
tened from side to side ; and in structure resembles 
that of the humerus. The inferior extremity is 
rounded below, but flattened above (towards the 
hollow of the knee) and behind. 

Hip-joint. The articular cavity is deepened by 
a fibrous ring, labrum cartilagineum, which fits 
closely upon the caput femoris ; from this /abrum the 
joint-capsule arises, to be inserted behind the head ; 
close to the lower border of the cavity a /iga- 
mentum teres arises, which is inserted into the caput 
femoris. 


2. The leg. 

Tibio- fibula, os cruris (Fig. 45). This 
consists of a single bone, the os eruris; it is 
often called the {iZia, but presents, however, dis- 
tinct indications of being formed of two bones, 
the #ilia and jfibula. The shaft is not quite 
straight; it is thinner in the middle and flattened 


E 


Femur of Rana escu- 
lenta, right side,twice 
nat. size. 

a Anterior extremity. 

p Posterior extremity. 


50 THE BONES AND JOINTS. 


from above downwards. On the upper as also 
on the lower surface of the bone is a groove, 
passing from the middle towards each ex- 
tremity ; this deepens as it proceeds, and is an 
indication of the compound nature of the bone. 
2 In the middle of each surface of the bone 
is the opening of a canal, through which a 
bristle may be passed: the canal has bony 
walls, The medullary cavity is, for the most 
part, double, bemg single only in the middle. 
The anterior extremity is articular, and presents 
a median groove, which is prolonged on to the 
under surface. The posterior extremity forms 
a transverse condyle, which has at its inner 
part a notch for the tendon of the m. tidzalis 


posticus. 

The knee-joint consists of a capsule strength- 
ened by theinsertions of numerous tendons. © 
Within this the articular surfaces 
of the femur and tibio-fibula are 
connected by means of fibro-elas- 
tie bands, which spring from the 
latter bone and cross each other, 

thus representing the /19. cruciata. 

Section of thetibio- The articular surfaces are more- 
fibula through the 

underextremity. over deepened by loose semilunar 


> 


Fig. 46. 


Tibio-fibula of Rana escu- 
lenta, twice nat. size, seen 
from below. 


aa Grooves. 


f Foramen nutritium. a pe is cartilages, corresponding with 
é Anterior ticular = epipnysis. G à - 
tremity. Ss m Marroweavitis. the inter-articular cartilages of 


. . x a 1/4 + + . . . 
t’ Posterior articular ex-  {” Connecting the knee-joint of man. In addi- 


tremity. mass. 

{Groove on malleolus in- {{/The two cylin- tion. on either side of the joint 
ternus for tendon of ders of bone. 3 one : 4 
m. tibialis posticus. are found auxiliary ligaments. 


3. The foot (Fig. 47). 


The ankle, ossa tarsi. The tarsus consists of two rows of 
bones. 

. The proximal row consists of two long tubular bones (Fig. 
47 ie which are parallel to each other, as undoubtedly cor- 
respond with the astragalus (/4/us) and calcaneum. The bones 
are separated in the middle, but approach each other at either end. 
The outer of these bones (c) I have named calcaneum, following 
Cuvier and Dugés; the inner, astragalus (a). The two bones are 


THE HIND-LIMB. 51 


surrounded and enclosed at 
their anterior and posterior 
extremities in a common epi- 
physis of calcified cartilage, 
which has the usual struc- 
ture found elsewhere. The 
ligamentum calcanet, which 
will be described below (see 
Muscles of Foot, Fig. 88 /c), 
may be regarded as an un- 
attached process of the heel’. 

B. The distal row of the 
tarsals are all composed 
of calcified cartilage. They 
are :— 

1. Os cuboidenm (Fig. 47 
cb), a flat plate of cartilage, 
concave in front, convex 
behind, placed between the 
common epiphysis of the 
astragalus and calecaneum 
(ac) and the ossa metatarsi IT 
and J/I. This corresponds, 
as Dugés suggests, with the 
separated os cuboideum and 
cuneiforme III of other ba- 
trachians, e.g. Bufo. 

2. On the inner side of 
the above, between the as- 
tragalus and metatarsus I lies 
a small body, concave in 
front, convex behind, which 
we may regard, with Dugés, 
as the analogue of the os 
naviculare (Fig. 47 7). 

3. This latter supports a 
cartilage which forms a pro- D \ 


jection on the inner border, __ ; à 
: : . Right foot of Ranaesculenta,palmar surface, twice nat. size. 
covered with skin. This , 


a Astragalus. h First, h’ second cartilage 
7 s ac Common epiphysis. of supplemental toe. 
consists of closely -united e Calcaneum. m Ossa metacarpi. 
1 e cb Os cuboideum. n Os naviculare, 
pieces, a small round, basal RP 


1 Meckel, /.c., II, p. 488, regards the cartilage in the tendo Achillis as such. 
E 2 


52 THE BONES AND JOINTS. 


piece (4), and a flattened beak-like piece (4’). Dugés considers 
these pieces as the first and second ossa cuneiformia ; I rather incline 
to Meckel’s opinion that they represent a rudimentary hallux, the 
first bemg the os metatarsi, the second a phalanx. Both are com- 
posed of calcified cartilage ; in 2. {emporaria the lime-deposit seems 
to be less than in 2. oxyrhinus and R. esculenta, and the projection 
consequently softer 1. 


b. The metatarsal bones, ossa metatarsi (Fig. 47,mI-V). The 
five ossa metatarsi are long, thin tubular bones, the anterior articular 
extremities of which are broader above and narrow below, hence are 
wedge-shaped, and anteriorly present flat surfaces for articulation 
with the ¢arsus. The shafts are long and thin; the posterior 
extremities have rounded heads. The comparative length of these 
is as follows: the fourth is the longest, then come the third, fifth, 
second, and first in order. In structure they resemble other tubular 
bones. 


e. The phalanges, phalanges digitorum (Fig. 47). The total lengths 
of the separate toes correspond with that of the ossa metatarsi, but 
the distinctive differences are increased, partly by the difference in 
number and partly by the varying lengths of the phalanges. The 
first and second toes have each only two phalanges, the third and 
fifth have each three, the fourth, which is the longest, has four. 
The terminal phalanges are somewhat hooked towards the plantar 
surface. 


’ In the text these two cartilages are termed the ‘ supplemental toe.’ 


SECTION II. 


THE MUSCLES. 


THE MUSCLES. 


LITERATURE. 


v. Altena, see p. 13. 

Anonymous, Ueber das Schultergeriist der Schildkréten mit den daran sitzenden 
Muskeln. Isis, 1827. (Contains remarks on the shoulder-muscles of the frog.) 

Carus, C. G. (1) Lehrbuch der vergleichenden Zootomie. 2nd Edit. Leipzig, 1834. 
(2) Erlauterungstafeln zur vergleichenden Anatomie. 1 Part. 1826. (Muscles 
of the Leg.) 

Chappuis, Morphologische Stellung der kleinen hintern Kopfmuskeln. Zeit. f. Anat. 
u. Entwickl. 1876. Vol. II, pages 287-297. 

Cuvier, Leçons d’anatomie comparée. Paris, 1835. Vols. I, II. 

Dugés, Recherches anatomiques et physiologiques sur la déglutition dans les 
Reptiles. Ext. des Annales des Sciences naturelles, Paris, 1827. 

Dugès, Leçons d’anatomie comparée. Paris, 1835. 

Duméril and Bibron, Erpétologie générale ou Histoire complète des Reptiles. 1836. 

Führbringer, Zur vergleichenden Anatomie d. Schultermuskeln. Jenaische Zeitschr. 
1873. Vol. VII. 

Klein, Beitriige zur Anatomie der ungeschwänzten Batrachier (Rana temporaria, L.): 
in Jahrshefte des Vereins fiir vaterländische Naturkunde in Wiirtemburg. 
6 Jahrgang. 1850. Page I. 

Kuhl, Beiträge zur Zoologie der Rana esculenta: in Beitr. z. Zool. Frankfurt, a. M. 
1820. Page 115. 

de Mann, Vergelykende myologische en neurologische studien over Amphibien en 
Vogels. Acad. Proefschrift. 1873. 

de Mann, Myologie comparée de l'extrémité post. chez les amphibiens. Niederl. 
arch. f. Zool. 1874. Vol. II. 

Marshall, The Frog. London and Manchester. 2nd Edit. 1885. Pages 60-71. 

Martin St. Ange, Annales des sciences naturelles. Vol. XXIV. 1831. Page 393. 

Meckel, System der vergleichenden Anatomie. Halle, 1828. Vols. III and IV. 

Pfeiffer, Zur Anatomie des Schultergürtels und der Schultermuskeln bei Säugethieren, 
Voégeln und Amphibien. Giessen, 1854. 

Rymer Jones, Article ‘ Reptiles’ in Todd’s Cyclop. of Anatomy and Physiology. 
1847-1852. Vol. IV. Page 263. 

Stannius, Handbuch der Anatomie der Wirbelthiere. Vol. II. Zootomie der Am- 
phibien. Berlin, 1856. 

Wagner, Icones Zootomicae. Leipzig, 1841. 

Wagner, Lehrbuch der vergleichenden Anatomie. Leipzig, 1834-33. 

Zenker, Batrachomyologia. Diss. Jena, 1825. 


THE MUSCLES, 


I. MUSCLES OF THE HEAD. 


I. Muscies oF THE EYE. 


1. M. rectus inferior (Fig. 48 77’). 


Dugès, post-orbito-sous-oculaire, n. 12.—Zenker, depressor oculi. 


This muscle arises by a very thin, almost thread-like tendon 
from the parasphenoid, near the foramen opticum, and becomes rapidly 


broader ; it lies beneath the tendon of 
the membrana nictitans and a part of the 
m. retractor bulli: then runs forwards 
and outwards to be attached into the 
lower part of the circumference of the 


eyeball. 
2. M. rectus eaternus (Fig. 48 re). 


Dugès, post-orbito-ex-oculaire, n. 14. 

Arises by a thin, thread-like tendon 
from the parasphenoid near the fora- 
men opticum, internal to and a little be- 
hind the m. rectus inferior : it then passes 
obliquely outwards over the #. retractor 
bulii and the tendon of the membrana 
nictitans, to be inserted into the outer 
and hinder part of the circumference 
of the eyeball. 


3. I. rectus internus (Fig. 48 ri). 
Dugès, post-orbito-in-oculaire, n. 13. 


A long, thin muscle, which arises by 


Eye muscles of Rana esculenta, from 


below, 


On the right side (7. e. in the left eye) 
the lev. bulbi(/) is taken away ; on 
the left side it is still present. 


l 
la 
oi 


M. levator bulbi. 

M. lev. anguli scapulae 
M. obliquus inferior. 
M. obliquus superior. 
M. pterygoideus. 

M. retractor bulbi. 

M. rectus externus, 
First cervical vertebra. 


a thread-like tendon from the parasphenoid at the inner and 


Y 


56 


THE MUSCLES. 


hinder angle of the orbit, passes along its inner wall, and is in- 
serted into the antero-internal part of the circumference of the 


eyeball. 


4. M. rectus superior (Fig. 49 rs.). 
Dugès, post-orbito-sous-oculaire. 


Arises by a slender tendon from the fronto-parietal bone, widens 


Fig. 49. 


Eye-muscles of Rana esculenta, from 


above. 


n Membrana nictitans. 


n’ Tendon of membrana nictitans. 


p M. pterygoideus. 
rs. M, rectus superior. 
t M. temporalis. 


rapidly, and runs forwards and out- 
wards to be inserted into the upper 
part of the circumference of the dudbus. 


5. WM. obliquus inferior (Fig. 48 où). 
Dugès, pré-sous-orbito-oculaire. 

This muscle arises near the floor of 
the orbital cavity, at the inner and an- 
terior angle, from the palatine bone by 
a thin and long tendon, runs under 
Harder’s gland outwards and back- 
wards, and is inserted, almost at a right 
angle with the axis of the eye, into 
the anterior part of the circumference 
of the eyeball. 


6. M. obliquus superior (Fig. 48 os). 
Dugès, pré-sus-orbito-oculaire, n. 7. 


The tendon of this small muscle arises from the inner end of the 


Eye-muscles of Rana escu- 
lenta, from below, the m, 
recti and obliqui have been 
removed. 


n' Tendon of membrana nic- 
titans. 

r M. retractor bulbi, lower 
part. 

r’ Second part of same, 


palatine bone, near the origin of the m. obliquus 
inferior, runs upwards, backwards, and out- 
wards, and passes into a flat muscle, whicl: 
rapidly becomes broader, and is inserted into 
the upper surface of the eyeball. 


7. DL. retractor bulli (Figs. 48 7, 507, 7’). 
Dugès, orbito-post-oculaire or choanide, n. 10.— 
Zenker, m. opticus. 

This muscle surrounds the optic nerve, and 
is situated within the cone formed by the four 
recti muscles; it consists of three portions, 
which take their broad and fleshy (the recti 
and obliqui arise by thin tendons) origins from 
the under surface of the parasphenoid. The 
first portion (Fig. 50 7) arises from the under 
surface of the parasphenoid, nearly as far as the 


57 


MUSCLES OF THE HEAD. 


middle line, is broad and fleshy, and covers, from below, the tendon 
of the rectus externus, then runs forwards and outwards. The 
second portion (7”), which lies over this and the tendon of the m. 
rectus externus, has also a broad and fleshy origin, but runs more 
directly forwards, slightly crossmg the precedmg. The third 
portion arises above the two others by a strong thin tendon from 
the parasphenoid : it runs almost in the direction of the m. rectus 
internus, but more directly forwards. The first two portions 
pass more to the upper surface of the eyeball, the third more 
to the under surface; consequently the whole muscle forms a 
sheath surrounding the eyeball. The fibres to the upper surface 
of the eyeball are inserted somewhat in front of the equator of 
the eyeball, those to the under surface somewhat behind it. 


8. W. levator bulbi, Dugès (Figs. 48 7, 51 /, 52 /). 
Dugès, fronto-pterygoidien, n. 9.—Klein, sustentator bulbi. 


There is no bony floor to the orbital cavity, and the oral and orbital 
cavities are only separated by soft tissues; these are :—the mucous 
membrane of the mouth, 
a thin fascia, and above 
this the muscle under I 
consideration. The fibres p 
of this muscle run from | 
before and from the inner 
side obliquely backwards 
and outwards, below all 
the remaining muscles of 


the eye, with the excep- 
tion of the origin of the 
m. retractor bulbi, and 
the tendons of the 
obliquus inferior, and the 
m.  plerygoideus ; they 
arise on the inner side 
from the upper and outer 
border of the fronto- 
parietal bone (Fig. 51), 


ne. 


Transverse section through the 
skull and orbital cavities of 
Rana esculenta. 


b Bulb of eye. 

e Skull cavity. 

g Mucous membrane. 

Z M. levator bulbi. 

m Upper jaw. 

ñ Membrana nictitans, 

n’ Continuation of same to the 
lower eyelid. 

p Upper eyelid. 


d.p 


M. levator bulbi of Rana 
esculentu, seen from 
above; the eyeball 
which rests. on it has 
been removed. 


d.p M. depressor palpe- 
brae inferioris. 


tM. levator bulbi. 


n Membrana nictitans. 
p. M. pterygoideus. 
t M. temporalis. 


also from the transverse portion of the parasphenoid and ptery- 
goid bones, anteriorly from the sphenethmoid and palatine bones ; 
they run first downwards, then, in the direction indicated, under- 


58 THE MUSCLES. 
neath the eye; and are inserted externally by means of tendinous 
fibres into the superior border of the upper jaw. 


9. From the foregoimg muscle certain fibres pass to the lower 
eyelid, which may be regarded as a depressor palpebrae inferioris 
(Fig. 52 d.p). 

Manz! has described a muscle as depressor palpebrae inferioris 
which arises in the neighbourhood of the external angle of the 
eye, somewhat behind and below the lower border of the orbit, thence 
passes obliquely upwards to be inserted into the lower eyelid. This 
description is right as regards the insertion, but needs correction 
as. regards the origin. The muscle is attached to the orbital border 
in so far that the tendinous expansion, into which the levator bulbi 
passes at its external border, is attached into the upper jaw; this 
bundle splits off from the upper surface of the levator bulbi at its 
middle, and runs outwards on the under surface of the eyeball to the 
hinder part of the lower eyelid. 


( 10. Tendon of the membrana nictitans? (Fig. 53 x’). The 
pigmented free border of the nictitating membrane passes, at the 
inner and outer angles of the eye, into a ten- 
don which passes for some distance through 
fibrous tissue, then descends to the under 
surface of the eyeball and joins that of the 
opposite side, so that the free border of the 
eyelid, together with this tendon, form a com- 
plete rmg. The tendinous part of the ring, 
which is thin and thread-like, is found 
on the under surface of the eyeball, and lies 
under the m. retractor bulbi, and is bound to 
this muscle by connective tissue. Manz is 


Fig. 53. 


Eye-muscles of Rana escu- 


tenta, from below, the m. 
recti and obliqui have 
been removed. 


n’ Tendon of membrana nic- 
titans. 

x» M, retractor bulbi, lower 
part. 

x’ Second part of same. 


clearly shown in the figure in Plate VI of Dugés. 


right in saying that the two muscles described 
by Dugès as levatores palpebrae inferiores (or- 
bito-palpebral anterieur and posterieur, n. 5 
and 6) do not exist; as is also the suggestion 
that he has confounded the tendon of the 
nictitatmg membrane with these; this is 


With regard 


to the actions of these eye-muscles, it is plain that the four straight 


1 Manz, Berichte der naturf. Gesellschaft zu Freiburg, 2 Band, 4 Heft, 1862, 


p. 391. 


? Compare Manz, l. c. 


MUSCLES OF THE HEAD. 59 


and two oblique muscles rotate the eyeball about three axes, one 
the axis of the eye, one vertical, and the third passing from behind 
forwards and inwards. The m. retractor pulls the eyeball into 
the orbital cavity backwards and downwards, while the levator 
raises it. 

There is less agreement about the movements of the eyelids, or 
rather of the lower eyelid, for the upper has no independent 
movements. Dugés (/.c.) says that the two muscles, which he con- 
siders to be /evatores palpebrae inferiores, and which, according to 
him, are connected with the m. retractor bulbi, draw up the lid as it 
is being drawn backwards and downwards by the latter muscle. 
The depression of the lid on the relaxation of the retractor and 
projection of the eyeball is due simply to elasticity. Manz!, on the 
contrary, has shown that the sinking of the eyeball by the con- 
traction of the retractor must necessarily cause a rising of the 
nictitating membrane, as its tendons are attached to that muscle 
and so must follow its movements. 

The depression of the lower lid occurs simultaneously with the 
raising of the eyeball by means of the m. levator bulbi, through the 
contraction of the m. depressor palpebrae inferioris, which proceeds 
from that muscle; this is easily understood, as they are but parts 
of the same muscle. 


II. Musczes or THE Face. 


11. MM. intermaxillaris s. dilatator narium (Fig. 54 im). 
Dugés, intermaxillaire, n. 1.—Zenker, intermaxillaris medius. 
This small muscle les in the space 
between the vertical processes of the 
two premaxillary bones, and consists of 
obliquely-crossing fibres arising from 
the one bone and inserted into the oppo- 
site one. It brings together the pro- 
cesses of the intermaxillary bones, so 
that their upper extremities approach 
exch m@bher, . cAl the same, time, Shey egy sure, euienta. 
cartilaginous nasal coverings or wings an Cartilaginous nasal alae. 


: i’ Vertical process of naxillary 
(am) diverge and the nares expand; “ “°° 
hence we may regard this muscle as ‘m M. intermaxillaris. 
: : D In M. lateralis narium. 
corresponding to a dilatator narium. n Cartilaginous nose capsule. 


im ] 


DC D 14e 


60 THE MUSCLES. 


12. I. lateralis narium (Ecker), (Fig. 54 /n). 


Zenker, m. intermaxillaris lateralis—Klein, m. nasalis inferior.— 
Dugés, sus-maxillo-pré-nasal, n. 2. 


This small muscle occupies the space between the anterior portion 
of the maxillary bone and the ascending process of the premaxillary 
bone. It arises from the maxillary, and ascends obliquely forwards 
to be inserted into the outer border of the ascending process of the 
premaxillary bone. It is antagonistic to the foregoing. 

A third muscle is described by Dugès as sus-mawillo-post-nasal, 
n. 3 (uasalis externus, Klein) ; according to him it passes from the 
proc. nasalis of the maxillary bone to the outer border of the nasal 
opening, which it widens. According to Klein (/.c., p. g), this 
muscle in 2. temporaria runs to the upper border of the maxillary bone 
beneath the lower eyelid, and is long and narrow. I have, however, 
never been able to find muscular fibre in this situation. 


III. Muscies or THE Lower Jaw. 


as: M. depressor maxil- 

lae inferioris, Carus, Zenker 
(Figs. 55, 56, 63 d.m.). 

Cuvier, L.c., II, 141, digas- 


tricus.—Dugès, sus-occipito- 
dorso-angulaire, 32. 


This is a strong, trian- 
gular muscle, wide above, 
pointed below. It is placed 
between the head and the 
shoulder-blade. It arises in 
two portions; the greater, 
from the fascia dorsalis 
(fd ), covers the scapula, and 
passes inwards and back- 
wards over the muscles of 
the back ; anteriorly it passes 

Muscles of the back and shoulder. over the m. temporalis and 
anit = ee maxillae, arising from the fascia ri attached to the fronto- 


dorsalis. On the right side it iscut through parietal and squamosal, 
and reflected. 


fa Martin dovsalia being continued to the 
Jd Same cut near the spinous processes. fascia of the upper eyelid. 
z M. infraspinatus. y 7 

La M. levator anguli scapulae. £ The second part is smaller, 
ld M. latissimus dorsi. J 


ce M. retrahens scapulae. and ope by fleshy fibres 
se M. sternocleidomastoideus, from the postero-superior 


MUSCLES OF THE HEAD. 61 


arm of the squamosal, and from the posterior and inferior border 
of the cartilaginous tympanic ring. The two parts unite and are 
inserted into the hinder angle of the lower jaw. Cuvier correctly 
considers that only the anterior portion corresponds to the digastri- 
cus, the posterior answering to the m. cervico-maxilluris of snakes. 
It draws the lower jaw down and opens the mouth. 


AT a ie 
14. 11. temporalis (Figs. 49, 52, 56, 57 t). 
_ Cuvier, m. temporalis, I, l.c., p.138.— Dugès, sous-rupéo-temporo-coronoidien. 
This muscle, together with the m. pteryqgoideus, occupies the space 
> LOS q ; I } 
between the prootic and the eyeball; it arises by the ereater 
st) 2 J 5 
part of its fibres from the 
upper surface of the pro- 
otic; it passes, narrowing, 
beneath the anterior arm of 
the squamosal, then over 
the pterygoid bone, between 
this and the maxillary and 
quadrato-jugal, receiving on 
the way other fibres which 
arise from the anterior border 
of the inferior arm of the 
squamosal and from the 
anterior circumference of the 
tympanie nng. The collécted, a es 
fibres end in a broad flat dm M. depressor maxillae, its origin where covering 
: wee: ; à the m. temporalis reflected at *. 
tendon, which is inserted into 4 M. Iatissimus dorsi. 
the inner surface of the so- ” M: masseter. 


‘ ‘t M. temporalis, origin. 
called proc. coronoideus. Lower portion of same. 


Muscles of the lower jaw of Rana esculenta. 


15. MW. pterygoideus (Figs. 49 p, 52, 57 pt). 


Cuvier, m. temporalis, II, /.c.—Zenker, m. massetericus, 1. ¢., p. 25.— 
Dugés, pré-rupéo-pterygo-maxillaire, 31. 


This is partly covered by the foregoing, and lies eee it and 
the eyeball. It arises at the inner wall of the orbit from the 
frontoparietal, and from that portion of the prootic which may be 
regarded as the a/a magna, above the m. retractor bulli. The muscle 
is broad, and compressed from before backwards: it runs down- 
wards covered by the m. ¢emporalis, and soon passes into a long, 
thin tendon (Fig. 57 pt), which is inserted, behind the m. temporalis 
and immediately in front of the joint, into the inner surface of the 
lower jaw. 


62 THE MUSCLES. 


16. MW. masseter (Figs. 56, 57 m). 
Dugés, zygomato-maxillaire, n. 29. 
Arises as a somewhat broad muscle from the horizontal process of 
the quadrato-jugal and is inserted 
into the outer side of the lower 
jaw, opposite the insertion of the 
m. temporalis. 


17. M. submaxillaris (Figs. 58, 
59, 61 sm, sm’). 


Cuvier, m. mylo-hyoideus, l.c., IT, 


536. — Zenker, mylo-sternoideus, 
p- 25. — Dugés, sous-maxillaire, n. 
De. 


This muscle forms the floor of 
the mouth as does the mylo- 
Muscles of the lower jaw of Rana esculenta. hy ouleus In man ; it 18, however, 
dm M. depressor maxillae cut through and not inserted into the hyoid bone. 


reflected. ë 
Po M devAtor aneulli colpulas: It arises—1. From the whole of 
i.d. M. latiss. dorsi, cut through and reflected. the inner surfa ce of th e upp er 
m M. masseter. 2 
pt M. pterygoideus. border of the lower jaw!, except 
s Scapula. : 
s’ Suprascapula. near the angle (Fig. 58 Si) ; 


s.c. M. sternocleidomastoideus. 
tt M. temporalis cut through and reflected. 


2. By a small portion (Figs. 58, 
59, 61 sm’) near the skull, from 
the cartilaginous anterior cornu of the hyoid-bone which projects 
from the cartilaginous part of the prootic bone. This portion 
descends along the cornu to unite with the other portion. The 
two together form a membranous layer, the fibres of which run 
transversely and meet in a band of connective tissue along the 
middle line, forming a kind of Zinea alba. The sheath runs for- 
wards to the most projecting part of the lower jaw superficially to 
the m. submentalis. Slightly in front of its posterior border the 
muscle is attached in its whole breadth to the skin of the throat 
by a fine lamella of connective tissue, which is not always complete. 
The posterior border of the muscle is attached to a fascia, which 
passes between the deeper muscles and is attached to these. It is 
known that this muscle plays an important part in the movements 
of respiration and swallowing; but its precise action has not yet 
been worked out. 


1 A second origin from the lower border of the mandible, described by Klein, is 
not to be found. The appearance is due to the exit of vessels and nerves from the 
groove between the mandible and the muscle. 


MUSCLES OF THE HEAD. 63 


18. MM. submentalis (Fig. 59 smt). 


Cuvier, transversus, l. c., p. 588. — Dugés, 4, sous-mentonnier. — Zenker, 
m. lingualis (incorrectly brought into connection with m. hyoglossus). 


This small muscle lies in the anterior angle of the lower jaw 
between the dentary bones. It consists of transverse fibres which 


Fig. 58. 


Vy 


Y 


Hy / / 
MU , 


/ | No oe 


Muscles of the throat, chest, and abdomen of Rana esculenta. 
sm M. submaxillaris. 
sm’ Hinder portion of same arising from the anterior cornu of the hyoid bone. 


(For other references see page 68.) 
pass from one bone to the other. Below it is covered by the most - 
anterior portion of the m. submaxillaris. 
Its action is to approximate the sides of the lower jaw: according 
to Dugés (/. ¢., p. 123), it assists in closing the nostrils, by drawing 
together the sides of the lower jaw and thus raising the premaxillae. 


64 THE MUSCLES. 


IV. Musczes or THE Hyorp BONE AND THE TONGUE. 


19. IM. geniohyoideus (Figs. 59 gh, 60 gh). 


Cuvier, IV, 1, 536.—Dugés, n. 16.—Zenker, p. 30.—M. St. Ange, l.c., 
Pl, X XVI, f. 1, 13, p.423. 

Arises from the lower jaw in two portions, the one from near 
the middle line above the m. submentalis, the other more externally 
from the upper border of the 
lower jaw. The two parts unite 
to form a long, flat muscle, 
which lies on the ventral sur- 
face of the body of the hyoid 
bone, and divides posteriorly 
into two portions. One of these, 
the median (Figs. 59, 609”), 
is inserted into the inner border 
of the posterior horn of the 
hyoid bone, and is here attached 
to a fascia which covers the m. 
hyoglossus from beneath. By 
the same fascia the muscles of 
opposite sides are connected 
in the space between the two 


Muscles of the hyoid bone and the tongue of Rana 


esculenta. posterior cornua. The lateral 
The m. submaxillaris has been removed close to se : FALSE 
eee division (Figs. 59, 60 gi’) is 


em! Origin of the hinder portion ofsamefrom attached to the posterior carti- 
the hyoid bone. : ‘ Ê 

nn oies laginous process of the hyoid 

gh’ External portion of same. ‘ bone. 

gh’ Internal portion of same. 

H Body of hyoid bone. 


[. ster } 10° 

A das 20. M. sternohyoideus (Figs. 
~ hg M. hyoglossus. F0, 60 sh). 

oh M. omohyoideus. 99 . ) : : 

ph Mm. petrohyoidei. Cuvier, IV, 1, 538 (pubio-hyoi- 

sh M. sternohyoideus. deus). — Dugés, n. 17, sterno- 

sh’ External origin of same. : 0 

sk! Internal origin of same. xipho-hyoidien.— Zenker, p-30- 

ue M. submaxillaris. : This muscle forms the cer- 

sm’ Origin of hinder portion of same. . 

smt M. submentalis. vical part of the #. rectus 


abdominis and is, in fact, a direct continuation of it. It arises by 
an inner portion (Fig. 59 sh”) from the upper surface of the inner 
extremity of the coracoid and from the xiphisternum, while the 


MUSCLES OF THE HEAD. 65 


outer portion (sz’) is an immediate continuation of the m. rectus 
abdominis, which passes mto this 
muscle at about the fifth cxscrip- 
tio tendinea. The muscle passes 
forwards on the upper surface of 
the coracoid and of the clavicle, 
under the pericardium towards 
the hyoid bone; here the muscle, 
hitherto horizontal, suddenly be- 
comes (compare Fig. 60) ver- 
tical, and passes between the 
two insertions of the m. genio- 
hyoideus, and is inserted for a 
considerable length into the lower 
surface of the hyoid bone and the 
anterior extremity of the posterior 


Fig. 60. 


Muscles of the tongue and of the hyoid bone of 
cornu. Rana esculenta, from below. 


gh M. geniohyoideus. 
; ane adeus “ane. fe gh’ External origin 
21. M. omohyoideus (Figs. 59, ‘y internal origin 
60 oh). H Body of hyoid. 
H’ Anterior cornu. 
Cuvier, /.c., p. 539.—Dugés, n. 18, H” Posterior cornu. 


interscapulo-hyoidien ou omo- #9, M. hyoglossus. 
Er hg’ Hinder origin of same. 
hyoidien. — Zenker, p. 31. oh M. omohyoideus. 


M. St. Ange, /. c. ph.t, 2, 3, 4, first, second, third, and fourth 
F : m. petrohyoideus. 
Arises from the anterior border sn M. sternohyoidens. 
of the bony scapula, and is in- 
serted into the outer part of the ventral surface of the body of the 


hyoid : it is partially covered by the m. sternohyoideus, 


} of samme, 


22. M. petrohyoideus anterior (Ecker), (Fig. 61 ph1). 


Dugès, 10, rupéo-cérato-hyoidien.—Zenker, m. pelro-ceraus? p. 30.— 
Klein, basio-hyoideus, L. c., p. 71. 

A thin, flat muscle, narrow above, but broadening rapidly 
below, which arising from the outer extremity of the prootic 
bone, partially surrounds the pharynx below, into which some of 
its fibres are inserted; it is attached to the ventral surface 
of the body of the hyoid bone, near the lateral notch. The 
chief action of this muscle appears to be that of a m. constrictor 
pharyngis. 


F 


66 THE MUSCLES. 


23, 24, 25. Mm. petrohyoidei posteriores (Ecker), (Figs. 61 
pee; 3, 4). 


Cuvier, mm. stylohyoidei, l.c., p. 537.—Dugés, 20, 21, 22, masto-hyoi- 
deus (Fig. 4).— Zenker, petro-hyoideus superior and inferior.— 
Klein, stylo-hyoideus, l.c., p. 18. 

These are three long, thin muscles, which lie nearly parallel to 
one another, and run from the prootic bone to the posterior cornu 
of the hyoid bone. All three arise, 
covered by the m. sternocleidomastoi- 
deus, from the lateral extremity of 
the prootic, pass round the pharynx 
and are attached, the m. petrohyoideus 
posterior primus (Fig. 61 ph2) to the 
anterior extremity, the secundus (Fig. 
61 ph 3) to the middle; and the Zertius 
(Fig. 61 ph 4) to the hinder extremity 
of the posterior horn of the hyoid 
bone. 


= 26. M. hyoglossus (Figs. 59, 60, 


\ 61 hq). 
Mrecles of the hyoid bone of Rana escu- Cuvier, /. c., p. 588.—Dugés, 24, hyo-glosse. 
. lentu, seen from the right side and ° : 
re Arises from the bony posterior ex- 
Ht’ coi cornu. tremity of the hinder process of the 
18 ed osterior cornu. eae 
PMR ee les, hyoid bone (47). The muscles of the 


H H Body of hyoid bone. = : “ de . 
ph: M. petrohyoideus anterior. two sides pase forwards and Onn 


ph 2,3.4 Mm. petrohyoidei posteriores. to the middle line, where they unite. 

sm M. submaxillaris. 

sm’ Hinder, portion of same. The azygos muscle thus formed runs 
forwards on the ventral surface of the 

hyoid bone, between the mm. geniohyoidei, over the anterior border 

of the hyoid, and passes into the tongue, where it turns backwards 


and runs to the tip. (For action, see tongue.) 


27. M. genioglossus. 
Cuvier, /. c., p. 587.—Meckel, /. c., IV, 339.—Dugés, 23, genio-glosse. 


Arises above the insertion of the m. geniohyoideus on either side 
near the middle line from the two anterior bones of the lower jaw. 
The two origins quickly unite to form a thick, very firm muscular 
belly, which in its course backwards rapidly thins, and is distributed 
by numerous bundles ; decussating with the fibres of the m. hyoglossus 
at an acute angle, it runs on to the anterior extremity of the tongue. 


MUSCLES OF THE TRUNK. 67 


II. MUSCLES OF THE TRUNK. 


I. Muscies OF THE ABDOMEN. 


In the formation of the abdominal wall the following muscles 
take part :—(1) m. rectus abdominis, (2) m. obliquus externus, (3) m. 
obliquus internus, (4) the portia abdominalis of the m. pectoralis. 
Above, the m. obliquus internus forms a kind of diaphragm, partially 
separating the abdominal from the thoracic cavity (p. 70). 


28. MW. rectus abdominis (Fig. 627). 
Dugès, pubio-thoracique, n. 52. 

These muscles, situated on either side of the middle line of the 
abdomen, are as a rule traversed by five notched cuscriptiones ten- 
dineae. Each muscle arises, by a narrow, strong tendon, from the 
inferior border of the pubes, passes forwards, and quickly widening, 
divides at the second inscriptio tendinea (counting from behind) into 
two portions. 

(a) The Outer portion (Fig. 62 7) runs into the portio abdominalis of 
the m. pectoralis, and forms the greater lateral division of that muscle. 

(4) The Inner (7’) continues as the m. rectus abdominis and gradu- 
ally narrows anteriorly. At the sternum some of the fibres (the 
median) are inserted into the dorsal surface of the cartilaginous 
plate of the xiphisternum, while the greater part of the muscle con- 
tinues forwards over the coracoid to become the m. sternohyoideus 
at about the fifth zuscriptio tendinea (p. 64). 


29. M. obliquus externus (Fig. 63 oe, 0c’). 
Zenker, /.c., p. 31, m. obliquus.—Dugés, dorso-sous-abdominal, n. 54. 

The m. obliquus externus arises from— 

(a) The aponeurosis covering the long muscles of the back, and 
by this from the spinous processes. The anterior edge of the 
m. obliquus externus covers the posterior edge of the m. latissimus 
dorsi, which arises from the inferior, ventral surface of the aponeu- 
rosis. The aponeurosis also divides laterally into two parts, one of 
which, the posterior, passes into the od/iqguus externus, while the 
anterior forms the tendon of origin of the depressor maxillae inf. 
(dm) (compare Fig. 66). 

(4) A second, narrow portion, portio omo-abdominalis (Fig. 63 oe’) 

F 2 


68 THE MUSCLES. 


(m. xipho-adscapulaire, Dugés, n. 62), arises from the posterior 
border of the scapula by a thin tendon, and becomes broader as it 
Fig. 62. 


SUI 
f i 


| ‘it 7] hi Z 

7 

SO M/A 
LI LIM 


ul) Z 
Wy 


Muscles of the chest, throat, and belly of Rana esculenta. 


ch M. coraco-humeralis. 
d M. deltoideus. 
oi M. obliquus abdom. internus. 
oe M. obliq. abdom. externus. 
oe’ Scapular portion of same. 
oh M. omohyoideus. 
p’ Port, sternalis anterior of m. pectoralis, 
p” Port. sternalis posterior of same. 
yp’ Port. abdominalis of same. 
_ 9”  M. rectus abdominis, 
7’ Inner portion of same. 
sh M. sternohyoideus. 
sm M. submaxillaris. 
sm’ Hyoid origin of same. 
sr M. sternoradialis. 


runs downwards and backwards, to join the anterior border of the 
other and larger portion. 


à 


MUSCLES OF THE TRUNK. 69 


The whole muscle is attached by its most anterior fibres to the 
cartilage of the xiphisternum, the rest passing into an aponeurosis 


Fig. 63. 


Muscles of trunk of Rana esculenta, from the right side. 


cd M. cutaneus femoris. 

d M. deltoideus. 

d.m. M. depressor maxillae. 

i M. infraspinatus, 

td M. latiss. dorsi. 

oe M. obliquus abdom. externus. 
oe’ Scapular origin of same. 

ss M. subscapularis. 

tM. triceps brachii. 


which, inseparably connected with the ivscriptiones tendineae, traverses 
the lower surface of the m. rectus abdominalis to the linea alba. 


30. M. obliquus internus (and transversus), (Figs. 64, 65 où). 
Dugès, ileo-transverso-sous-sternal, p. 53.—Zenker, transversus, L. c., 
p. 31.—Kuhl, transversus, 1. c., p. 116. 

This muscle corresponds with the combined o4liquus internus and 
transversus, and has therefore been described either as the one or the 
other, by various authors. 

The fibres arise tendinously — 

a. From the transverse processes of the vertebrae from the 
fourth backwards, and from the fascia covering the mm. intertrans- 
versarie. 

b. From the iliac bone, bya strong tendon from its upper border, 
and by a few weaker fibres from its outer surface. The latter fibres 
are covered by the former, and these end posteriorly in a sharp 
concave border. 

The muscular bundles diverge from these points, some running 
forwards, some backwards; the former are only partially covered 
by the portio omo-abdominalis of the m. obliquus externus (compare 


70 THE MUSCLES. 


Figs. 62, 63), in front of the anterior edge of that muscle. The 
posterior border of the muscle is uncovered. 


Fig. 64. 


Second layer of abdominal muscles of Rana esculenta, from the right side and below. The 
m. obliquus externus and the right anterior extremity has been removed. 


dm M. depressor maxillae. 

hg M. hyoglossus. 

ld M. latissimus dorsi and infraspinatus. 
oi M. obliquus internus. 


oi’ Insertion of third portion of same. 


oi” Second portion inserted into the pharynx. 
pe Pericardium. 

ph4. M. petrohyoideus quartus. 

x Mz. rectus abdominis. 

ss M. subscapularis. 


The insertions of the muscle are very various, and as a conse- 
quence very various functions are accomplished by it. 

a. The most anterior part of the muscle (Fig. 65 02”), the fibres 
of which run forwards, is attached— 

1. Partly to the xiphisternum and the coracoid. 

2. A second portion, viz. that arising from the transverse pro- 
cesses of the fourth vertebra (Fig. 64 02”), surrounds the pharynx 
like a diaphragm (Fig. 65 0e), and is attached to its side as far as 
the dorsal aspect (Fig. 65 02’). This portion is lightly separated 
from the following. 

3. A third portion, placed behind the preceding, runs from the 
pharynx over the pericardium (Fig. 64 pc), and is attached to this 
nearly as far as the middle line (Figs. 64 02’ and 65 oi”), resting 
on the sternum, the m. rectus and m. sterno-hyoideus. The lines of 
insertion of the muscles of opposite sides form an angle, open in 
front. In the thin borders of this portion the muscular bundles lie 
almost entirely in simple layers, and they are therefore well adapted 
for microscopical purposes. 

b. The middle and posterior portions of the muscle pass down- 


MUSCLES OF THE TRUNK. F1 


wards and slightly backwards, towards the outer border of the 
m. rectus; there they pass into a tendon which, for the most part, 
runs on the upper surface of the rectus to the linea alba. 


II. Muscies oF THE. Back. 


The muscles of the back are covered by a fascia, the fascia dor- 
salis (Fig. 66 fd), attached to the spinous processes of the vertebrae. 
Anteriorly, where it covers the m. tempora/is, it is attached to the 
frontoparietal and squamosal bones, posteriorly to the superior border 
of the iliac bones and the extremity of the urostyle. The posterior part, 
which covers the origins of the 
m. longissimus dorsi, of the m. 
coccygeo-iliacus, and of the 
coccygeo-lumbaris, is especially 
strong. From the anterior 
part several muscles arise la- 
terally, viz. a portion of the 
m. obliquus abdominalis exter- 
nus, of the ». latissimus dorsi, 
and of the m. depressor maxillae 
inferioris. In the uppermost 1 
layer, immediately covered by 
the fascia dorsalis, lie the m. 


Fig. 65. 


cucullaris, the m. retrahens : 

scapu lae, the wm. latissimus M. obliquus internus, showing its attachments 
: ue cj superiorly. 

dorsi arising from the fascia » Xiphisternum, 

: ; 2 oe Oesophagus. 

itself, and the scapula with 5 x cbiiquusinternus, 


its muscles fs then come the 07 Fibres of m. obliq. int., which are inserted into 
the oesophagus. 


long muscles of the back 5 and oi” oi” Fibres of same, which are attached to coracoid 
in the third and deepest layer be 


Pericardium. 


p 
the short muscles of the back. * M. rectus abdominis. 
The individual muscles are as follows : — 


A. Lime Musess or rue Back (for moving the shoulder- 
cirdle and arm). 
31. M. cucullaris (Fig. 66 c). 


Cuvier, angularis.—Dugés, n. 38, sous-occipito adscapulaire.—Zenker, _ 
levator scapulae sublimis. 


In order to see this muscle, it is necessary to separate the fascia 
dorsalis from the spines of the vertebrae and to turn it back with 
the m. depressor maxillae inf. arismg from it. It is then seen to 


72 THE MUSCLES. 


rise from the posterior surface of the exoccipital as far as the 
middle line; the muscles of the two sides run backwards, diverging 
each from the other, so as to form an angle, and are then attached 
on each side to the anterior superior angle of the suprascapula at 
its under surface and median border. 

Cuvier considers this muscle as the analogue of the m. levator 
angult scapulae. Dugés and Meckel consider it to be the anterior part 
of the m. cucuilaris, the former thinking the posterior part of the 
muscle to be the m. rhomboideus. I cannot agree with these opinions, 
and I regard the muscle as simply representing the m. cucullaris of 
man (Ecker). 

32. AM. latissimus dorsi (Figs. 56, 66 ld). 
Dugès, n. 66, lombo-huméral.—Zenker, depressor brachii. 

This thin, triangular muscle arises from the ventral surface of the 
fascia dorsalis, and is posteriorly covered in part by the anterior 
border of the im. obliquus abdominis externus. The muscle becomes 
narrower towards the sides, and passes into a flat tendon, which 
blends with that of the i. énfraspinatus, and is attached to the 

Fig. 66. outer surface of the crista 
deltoidea of the humerus by 
2 a triangular expansion. 


33. M. retrahens scapu- 
lae (Ecker), (Fig. 667). 


Dugès, n. 49, lombo-adscapulaire. 
— Klein, m. rhomboideus, l. c., 
p. 26.— Zenker, omoplateus 
rectus? p.37, l.c.—Kuhl, l.c., 
124, retrahens rhomboideus. 


uli 


AM |) 


This flat, oblong muscle 
arises from the transverse 
process of the fourth verte- 
bra, and is connected with 
the third tendinous inserip- 
tion (counting from before) 

Muscles of the back and shoulder-blade. of the m. longiss. dorsi. Pos- 
in : ie arising from the fascia dor- teriorly its origin forms a 


salis, cut through and reflected on the right side. @onyex border, whence it 
fd Fascia dorsalis, 


fd’ Same cut through at the spines. runs forwards and to the 
AE ne nara. side ; it is inserted into the 
La M, levator anguli scapulae. À 

ld M. Latissimus dorsi. ventral surface of the supra- 


r  M. retrahens scapulae. : rs 
se M. sternocleidomastoideus. scapula , hear its inner border. 


MUSCLES OF THE TRUNK. 13 


This muscle lies near the m. serratus or transv. scap. tertius (Fig. 
68 ¢s”), and has an analogous position. It would, therefore, possibly 
be more correct to regard it also as a m. serratus. It arises 
from parts which represent ribs, and is inserted into the scapula. 
It has, at any rate, no analogy to the #. cucullaris, with which 
Dugés connects it, nor with the m. rhomboideus, which Klein holds 
it to be, as it does not arise from spinous processes. 


B. Lone Mousczes ov rue Back, 
34, M. extensor dorsi communis (Fig. 67 1g.d.). 

Dugès, n. 33-40, masse des muscles surspinaux devisée en huit faisceaux 
principaux: 1. vertebro-sus-occipital, 2-5. transverso-spinaux, 6. 
transverso-coccyg., 7. sacro-coccygien, 8. ileo-coccygien. The muscles 
1-7 form the lombo-costal, 8 the ischicoccyg., Cuv.—Zenker, m. sa- 
crolumbaris.—Klein, longiss. dorsi, coccygeo-lumb., coccyg.-iliac. 

This muscular mass is covered by the fascia dorsalis, the m. cucul- 
laris and retrahens scapula, and the suprascapula : it corresponds with 
(1) the m. ileo-costalis and longissimus dorsi, dorsi and cervicis (Henle) ; 
(2) the semispinalis and spinalis (Henle). 

The following separate portions may be made out :— 

35. (1) A7. longiss. dorsi (Fig. 67 ly.d.). 

This muscle arises from the most anterior part of the urostyle, runs 
forwards near the middle line, separated from the muscle of the 
opposite side by the spinous processes of the vertebrae. The inner 
portion passes over the posterior spinous processes without being 
connected with them, as far as the fifth, it is then inserted into the 
succeeding spines as far as the exoccipital bone. The lateral portion 
runs outwards and forwards to be attached to the transverse pro- 
cesses and oblique processes of all the vertebrae, from the sixth 
forwards, while accessory muscular slips arise from the transverse 
processes and from the anterior spinous processes which, merging 
in the general muscle-mass, are inserted with this into the occiput. 

The muscle is subdivided by a series of wavy, tendinous par- 
titions (Fig. 67), which arise from the transverse processes, and 
traverse the muscle in planes, the upper surfaces of which are 
directed upwards and forwards. This arrangement of the muscle 
indicates its relation with the lateral trunk muscles of fish and- 
fish-like amphibians. 


36. (2) A. coccygeo-sacralis (Fig. 67 ¢.1.). 
This muscle is partially covered by the preceding, it arises from 
the lateral surfaces of the anterior half of the urostyle; from this 


74 


THE MUSCLES. 


origin the fibres pass forwards and outwards to be inserted in two 
portions, the anterior set into the arch and the posterior set into the 


transverse process of the last vertebra. 


The former may be re- 


garded as m. intercruralis, the latter as m. intertransversarius. 


1 [ 4] 


== (TM 
À 


== - 
IP 1 


KK 


A 
H 2 
| NY WA 
TNA 2 
Whit \ 


ET 


Muscles of the back and pelvic girdle of Rana esculenta. 


Cite 
cl. 
gol. 


M. coccygeo-iliacus, 

M. coccygeo-sacralis. 

M. glutaeus, 

MM. intertransversarii, 
MM. intercrurales. 


M. 
M. 
M. 
M. 
M. 
M. 


intertransv. capitis inferior. 
intertr. cap. sup. 

ilio-lum baris. 

longissimus dorsi, 

obliq. internus. 

temporalis. 


37. (3) A1. coccygeo- 


iliacus (Fig. 67 c.i.). 


This muscle arises 
from nearly the whole 
length of the lateral sur- 
face of the urostyle, the 
anterior portion bemg 
concealed by the preced- 
ing muscle. The fibres 
pass outwards and for- 
wards to be inserted into 
the anterior two-thirds of 
the inner surface of the 
ilium. 


38. M. ilio-lumbaris 
(Klein), (Fig. 67 2/.). 
Duges, n. 51, transverso-ili- 


aque.—Cuvier, Zenker, 
etc., quadr. lumborum. 


Evidently represents 
the guadratus lumborum 
of human anatomy; it 
takes its origin from 
the anterior extremity 
of the ilium, and runs 
forwards to be inserted 
into the transverse pro- 
cesses of the vertebrae 
from the seventh to the 
fourth. 


MUSCLES OF THE ANTERIOR EXTREMITY. 75 


C. Suorr Musczes or run Back. 
39. AL. intertransversarius capitis superior (Ecker), (Fig. 67 1.c.s.). 
Dugés, n. 41, ex-occipito-transversaire sup. 
A small muscle arising from the prootic: it les above the 
levator anguli scapulae, and is inserted into the transverse process of 
the second vertebra. 


40. AT. intertransversarius capitis inferior (Fig. 67 i.c.i.). 
Dugès, n. 42, ex-occipito-transv. inf. 

This muscle lies on the ventral surface of the preceding one, but 
is easily separable from it; it arises from the angle of the prootic 
and is inserted, together with the preceding muscle, into the 
transverse process of the third vertebra. The x. vagus passes out- 
wards between these two muscles. 


41. MM. intertransversari dorsi (Fig. 67 à). 
Dugès, n. 43 to 50, intertransversaires. 
Seven small muscles, placed between adjacent transverse pro- 
cesses of the vertebrae; from the second to the last, in continuity 
with the muscles last mentioned. 


42. MM. intercrurales (Kicker), (Fig. 67 7’). 
Klein, p. 29, interspinales, interobliqui. 
Those muscular fibres found between the arches of adjacent 


vertebrae are so named. On account of the shortness of the 
spinous processes they can scarcely be named m. interspinales. 


III MUSCLES OF THE ANTERIOR EXTREMITY. 


I. MUusCLES OF THE SHOULDER-GIRDLE. 


A. Dorsat Muscres or THE SHOULDER-BLADE. 


(I.) Muscles arising from the head or trunk, and inserted into 
the scapulae, which they act upon primarily, and upon the shoulder- 
girdles secondarily. 

Some of these muscles, such as m. cucullaris and retrahens, are 
situated on the back, and have already been described with the 
muscles of that region. Others are attached partly to the under- 
surfaces of the scapulae and are only visible from below ; they are 
best seen in such a preparation as is shown in Fig. 68, made by 


cutting through the sternum in the middle line, and reflecting each 
half outwards. 


76 THE MUSCLES. 
(a) Muscles which arise from the skull. 


43. MM. levator anguli scapulae (Fig. 68 la). 


Dugés, sous-occipito-adscapulaire, n. 60.—Zenker, protractor scapulae, 
Pl. I, Fig. 5.—Cuvier, Leçons I, p. 379, describes this muscle as part 
of the m. serratus anticus magnus. 

A fairly strong muscle, which has a broad origin from the prootic 
and exoccipital bones as far as the foramen magnum, a few fibres 
are also attached to the lateral portions of the parasphenoid. The 
fibres run backwards and outwards, first in a frontal plane and 
then in a sagittal plane, to be inserted into the under surface of 
the suprascapula near the posterior border, where it encloses the 
hinder border of the m. interscapularis. 

Its action is to draw the shoulders forwards and inwards, or the 
head downwards. 


44, M. slernocleidomastoideus (Fig. 68 sc). 


Dugès, scapulo-mastoidien, n. 65.—Cuvier, sterno-mastoidien.—Zenker, 
protractor scapulae, PI. I, Fig. 5, 1. 

A narrow muscle placed in front of and externally to the pre- 
ceding muscle ; its general direction resembles that of the #. levator 
ang. cap. 

The fibres arise from the most external part of the prootic and 
from the hindermost part of the squamosal, under cover of the 
m. digastricus maxillae, and from the hinder portion of the cartila- 
ginous tympanic ring. Covered by these muscles, it passes 
backwards and downwards to be inserted into the concavity of. 
the anterior border of the scapula; externally to the origin of 
the deltoid. 

The action of this muscle is to draw the shoulder forwards 
and towards the middle line, or to bend the head downwards. 


45. M. protrahens scapulae (Fig. 68 ps). 
Dugés, Zenker, protractor acromii, Pl. I, Fig. 5, 3. 
This muscle lies to the outer side of the rectus capitis inferior : 
it arises from the prootic, and runs backwards and outwards upon the 


levator anguli scapulae, to be inserted into the scapula. 
It pulls the scapula forwards. 


MUSCLES OF THE ANTERIOR EXTREMITY. Te 


(b) Muscles which arise from the vertebrae. 
46. MW. transverso-scapularis major (Ecker), (Fig. 68 fs). 
Dugés, transverso-interscapulaire, n. 63.—Cuvier, l. ¢., p. 380, probably 


regarded as a portion of the serratus.—Zenker, Pl. I, Fig. 5, 3; 
depressor acromit, Pl. II, Fig. 3, 15.—Klein, depressor scapulae. 


This muscle arises by tendon from the cartilage of the transverse 
process of the fourth vertebra and by a slip from the cartilage 
of the transverse process of the third vertebra. Diminishing in 
size, the muscle passes outwards, forwards, and upwards to be 
inserted into the posterior border of the scapula, opposite the in- 
sertion of the m. sternocleidomastoideus. It draws the shoulder 
inwards, backwards, and downwards. 


47. M. transverso-scapularis minor (Ecker), (Fig. 68 ts’). 


Dugès, transverso-adscapulaire, n. 61.—Cuvier, regarded as part of the 
serratus.—Zenker, Pl. I, Fig. 5, 7, detractor scapulae. 


This is much shorter than the muscle just described; it arises 
under cover of the m. 
levator scapulae, from 
the transverse process 
of the third vertebra 
in front of the ¢rans- 
verso-scapularis major ; 
and runs outwards and 
forwards to beinserted 
into the ventral surface 
of the cartilage of the 
scapula, The action of 
the muscle is to draw 
the shoulder inwards, 
backwards, and out- 
wards. Duges re- 
gards this muscle as 


a portion of the serra- 


Wa ’ Muscles of the shoulder, from below ; the sternum has been cut 
cus neue HCTIERS, the through and the sides drawn apart. 


Fig. 68. 


ss 


remainder of which d Deltoideus. 


he considers is to be is Interscapularis. 
f d E I : it Intertransversarii. 
oun m the D orto la Ley. anguli scapulae. 
W185 = »s Protrahens scapulae. 
scapular ge of the me 2 Sternocleidomastoideus. 
obliquus externus (xi- ss Subscapularis. 
2 ts Transverso-scap, major. 
pho-adscapulaire, Du- ts! Transverso-scap. minor. 


Ds 4 “aNSVeTSO-SCap. ‘tius. 
ges, n. 62). ts” Transverso-scap. tertius 


78 THE MUSCLES. 


48. M. transverso-scapularis tertius s. serratus (Ecker), (Fig. 
68 ts”). 


This is larger than the muscle just described; arising by a 
broad and flat origin from the transverse processes of third and fourth 
vertebrae, it runs upwards and inwards to be inserted into the 
ventral surface of the cartilaginous scapula near its inner border. 
In position, course, and action the muscle most nearly represents the 
m. serratus anticus of human anatomy. 


(II.) Muscles on the scapula, that is, arising from the scapula 
and inserted into the scapula or humerus. 


(a) Muscles on the deeper surface. 


49. M.  interscapularis 
(Fig. 69 2.s.). 


Fig. 69. 


Dugès, interscapulaire, n. 64. 


One end of this muscle is 
tendinous, and is attached to 
the outer extremity of the su- 
prascapula ; from this the 
muscle, becoming fleshy and 
narrower, runs towards the 
middle line to become at- 
tached to the ridge on the 
ventral surface of the scap- 
ula, from which the m. del- 
Muscles of right shoulder and upper arm, The cora- toideus and the m. subscapul aris 
ssc] and te dvi (ro teen dr arise, and between which it 

passes. It approximates the 


ch. M. coraco-humeralis. 


cl Claviele. scapula and suprascapula and 
c.o. Coracoid. 1 b 
Eden) essens the angle between 
d' Clavicular portion of m. deltoideus. them 

a M. infraspinatus. $ 


is. M.interscapularis. 
la. M. levator anguli scapulae. 


id. M. latissimus dorsi. 50. 11. subscapularis (Fig. 


p’ Sternal portion of m. deltoideus. = 

y! Anterior sternal portion of the m, pectoralis. 79 ss) 2 

p'" Posterior sternal portion of the m. pectoralis, Dugès, sous-scapulo huméral, 
s Scapula. 

sr. M. sternoradialis, 7 Ci 


tr. M. triceps brachii. 


This muscle is situated on 


MUSCLES OF THE ANTERIOR EXTREMITY. 


the upper or visceral surface of 
the scapula. It arises from a 
bony ridge found on the upper 
surface of the coracoid and of 
the proc. coracoideus of the scap- 
ula. The muscle runs outwards 
and is inserted, after widening, 
into the inner surface of the 
erista deltoidea of the humerus ; 
it is antagonistic to the deltoid, 
and draws the raised arm back- 
wards and towards the trunk. 


79 


Right shoulder, from below, arm strongly 
abducted, 


cl Clavicle. 

co Coracoid. 

d Deltoideus. 

d’ Clavicular portion of deltoid. 
h Humerus. 

ss Subscapular muscle, 


(b) Muscles on the superficial surface. 


51. MM. infraspinatus 
(Fig. 57, between /4 and 
dm, Fig. 71 à). 


Dugès, adscapulo-huméral, 
no 


The m. infraspinatus re- 
presents the m. infraspina- 
tus, teres major and minor of 
human anatomy. It is of 
triangular form, with the 
broad base directed in- 
wards ; it arises from the 
whole of the upper sur- 
face of the suprascapula 
except along the inner 
border which is formed : 
of hyaline cartilage alone : 
from this origin the fibres 
converge outwards to a 
flat tendon which unites 
with that of the m. /atis- 
simus dorsi to be inserted 
into the erista deltoidea hu- 
meri, by means of a thin, 
triangular, tendinous ex- 
pansion. 


SS 


OS 
SNS 


& 


SS 


XQ 


Laie fate 


Id 


Muscles of the back and shoulder. 


M. cucullaris. 

M. depressor maxillae, 
Fascia dorsalis. 

Fascia dorsalis reflected. 
M. infraspinatus. 

M. levator anguli scapulae. 
M. latissimus dorsi. 

M. retrahens scapulae. 

M. sternocleidomastoideus. 


80 THE MUSCLES. 


General arrangement of the muscles of the shoulder-blade. 
The muscles attached to the scapula and suprascapula are : 


1. Muscles of the back (m. cucullaris and m. retrahens scap.). 

2. Muscles of the neck (m. omohyoideus). 

3. Muscles of the abdomen (portio scapularis of the m. obliquus 
eaternus). 

4. True shoulder muscles (m. levator anguli scapulae ; m. sternoclei- 
domastouleus ; m. protrahens scapulae ; mm. transverso-scapularis major, 
minor, and tertius s. serratus; m. interscapularis ; m. subscapularis ; 
and the long head of the m. triceps). 

From above the following are visible: mm. cucullaris, a portion of 
the m. subscapularis, and the transverso-scapularis maior. 


From below (after cutting through and drawing aside the two 
halves of the sternum) may be seen: the omohyoideus, sternocleido- 
mastoideus, levator anguli scapulae, protrahens scapulae, transverso- 
scapularis minor and tertius, interscapularis and subscapularis, 


B. Vewrrat Moscres or rue Suourper (Pecrorat 


Muscrzs ) 


These arise from the sternum or shoulder-girdle and are inserted 
either into the humerus or into the radio-ulnar. 
52. M. pectoralis (Fig. 72). 
This is placed on the ventral surface of the shoulder-girdle and 
consists of the following parts : 


(a) Portio sternalis anterior (Ecker), (Figs. 72, 73 p°). 
Dugès, clavi-huméral, n. 70 (port. clavic. du grand pectoral). 

This is the anterior portion of the m. pectoralis, it arises from the 
sternum proper and the epicoracoids. Broad at the origin, it be- 
comes narrower as it runs outwards into a tendon attached to the 
crista deltoidea humeri. 


(8) Portio sternalis posterior (Kicker), (Figs. 72, 73 p”). 

Dugés, sterno-huméral, n. 71 (port. sternal du grand pectoral).—Klein, 
humero-sternalis. 

This muscle is placed immediately behind the portio sternalis 
anterior, it has a somewhat broad origin from the sternum and 
xiphisternum ; the muscle runs outwards and slightly forwards to 
be inserted into the groove beside the crista deltoidea humeri. The 
tendon of the m. sterno-radialis passes between these two portions 
of the m. pectorals. 


MUSCLES OF THE ANTERIOR EXTREMITY. 81 


(y) Portio abdominalis (Figs. 72, 73 p’”’). 


Dugès, abdomino-huméral, n. 69 (port. costal du grand pectoral).— 
Zenker, brachio-abdominalis.— Klein, humero-abdominalis. 


This portion represents that part of m. pectoralis major of human 


/ 


MG 
WY 
) 


Muscles of the chest, throat, and belly of Rana esculenta. 
ch M. coraco-humeralis. 
d M. deltoideus. 
oi M. obliquus abdom. internus. 
oe M. obliq. abdom. externus. 
oe’ Scapular portion of same. 
oh M. omohyoideus. 
p’ Port. sternalis anterior to m. pectoralis. 
Port. sternalis posterior to same. 
p”’ Port.abdominalis of same. 
r  M., rectus abdominis. 
vy’ Inner portion of same. 
sh M.sternohyoideus. 
sm M. submaxillaris. 
sm’ Hyoid origin of same. 
sr M. sternoradialis. 


G 


82 THE MUSCLES. 


anatomy which arises from the costal cartilages, and more par- 
ticularly that part which is connected with the aponeurosis of the 
m. obliquus abdominis externus. The muscle arises (1) from the 
m. rectus abdominis (Fig. 72 7), that is, it forms a direct continua- 
tion of the outer portion of this muscle; (2) the inner, smaller part 
arises from the superficial surface of the aponeurosis of the m. obl- 
quus abdominis. The muscle becomes narrower as it courses out- 
wards and forwards, the outer fibres being longer and more oblique 
than the inner. The action of this muscle will necessarily vary 
according to the part or parts which are brought into action ; 
speaking generally, the anterior extremities will be drawn down- 
wards and towards each other. 


53. M. coraco-humeralis (Duges), (Figs. 72, 73 ¢.h.). 
Dugés, n. 72.—Klein, adductor humeri. 

A long, narrow muscle, lying upon the posterior border of the 
coracoid and the lowest part of the m. subscapularis. By its posi- 
tion it corresponds most nearly with the m. pectoralis minor, although 
its insertion does not. It has a narrow origin from the coracoid 
near the sternum, whence it courses outwards, under cover of the 
port. sternalis anterior and posterior of the m. pectoralis, to be inserted 
into the middle of the humerus between the deltoid and internal 
head of the triceps. It draws the limb towards the trunk. 


54. M. sternoradialis (Cuvier), (Figs. 72, 73 s.r.). 
Dugès, pré-sterno-clavi-radial, n. 74. = 

This muscle evidently represents the biceps of man, it lies in 
front of the portio sternalis anterior of the m. pectoralis, its hinder 
border being under cover of the latter muscle. It takes origin from 
the episternum, omosternum, and the epicoracoid ; from this broad 
origin the fibres converge while coursing backwards and outwards to 
be attached to a strong tendon. This tendon plays in a groove along 
the crista deltoidea, and is held in position by tendinous bands 
arising’ from the insertion of the m. pecloralis ; it then pierces the 
lower portion of the muscular belly of the deltoid, and is inserted 
into the anterior extremity of the radial side of the radio-ulnar. 
The muscle is a powerful flexor of the forearm. 


55. Wii. deltoideus (Figs. 70, 72, 73 d). 
Dugès, pré-sterno-scapulo-huméral, n. 68. 
It is placed in front of and external to the m. sternoradialis, and 
represents both the m. deltoideus and supraspinatus of man. The 
muscle has two points of origin :— 


MUSCLES OF THE ANTERIOR EXTREMITY. 83 


(a) Portio scapularis, the 
larger, external portion is 
attached to the outer end of 
the clavicle, and to the ante- 
rior process of the precoracoid, 
but it arises chiefly from the 
dorsal surface of the scapula 
(from the same ridge as the 
m. subscapularis), and lastly 
from the anterior border and 
ventral surface of the scapula. 
The fibres pass outwards over 
the shoulder-joint. 

(b) Pars clavicularis (muse. 


Muscle of right shoulder and upper arm. The cora- cleido-h numerals Klein) arises 
coids (co) and the clavicles (c/) have been drawn 4 


Fig. 73. 


asunder after cutting through the sternum, from the inner extremity of 

Bors Anes atnerailie, the clavicle and from the omo- 
RE ie sternum and joins the portio 
-c.0, Coracoid. , 

d M. deltoideus. scapularis. 

ad’  Clavicular portion of m. deltoides. Alec ° 

à M. infraspinatus. The muscle is inserted into 
i.s. M. interscapularis. = 3; 
la. M. evator anguli scapulae. the humerus, the under part 
1.4. M. latissimus dorsi. of the portio scapularis being 
p’ Sternal portion of m. deltoides. 3 

p" Anterior sternal portion of the m. pectoralis. attached to the upper portion 


p”’ Posterior sternal portion of the m. pectoralis. 


ease of the erista deltoidea; the 
s.r. M. sternoradialis. outer fibres of this part, to- 
tr. M. triceps brachii. f 4 

gether with those of the pars 
clavicularis, are attached to the extremity of the crista deltoidea and 
to the mner surface of the humerus as far as the distal extremity ; 
just before its insertion the muscle is pierced by the tendon of the 
m. sternoradialis. The deltoid draws the limb forwards. 


II. Muscies or THE Fore-Limp. 


A. Musczes or THE Arm. 
M. sternoradialis (biceps). See page 82. 
56. M. triceps brachu (Fig. 73 t.r.). 
Dugès, scapulo-huméro-olecranien, n. 75.—Capes, Zenker, m. anconaeus. 
This muscle lies on the upper or dorsal surface of the arm, and 
has relations similar to those of the corresponding muscle in man. 
The long head arises from the posterior border of the scapula at the 
upper border of the glenoid cavity, and is here attached to the capsule 
of the joint ; the inner head arises from the upper and inner surfaces 
G 2 


84 THE MUSCLES. 


of the anterior half of the humerus as far as the extremity ; the 
outer head arises from the outer surface of the humerus. Additional 
fibres, which may be regarded as a fourth origin (m. swbanconaeus), 
arise from the upper surface of the hinder half of the humerus. 
The fibres from these several origins unite to form a strong muscle, 
which covers the upper, inner, and outer surfaces of the bone, and 
then passes into a tendon. This tendon is attached to the capsule 
of the elbow-joint and inserted into the proximal extremity of the 
radio-ulnar. <A cartilage, representing the olecranon, is found in the 
capsule at the point of attachment of the tendon. 


B. Musczes or THE Forearm. 
(1.) Muscles of the flexor surface. 

The muscles of this surface are arranged in two groups, so as to 
form, at the elbow-joint, a triangular depression (p/ica cubiti), mto 
which the tendon of the m. sternoradialis sinks, 

A. Muscles of the Inner Group. 
Fig. 74. 57. M. flewor carpi Is. radialis (Fig. 
TAsEG). 
Dugès, sous-huméro-carpien, n. 83. 

This represents either the flexor carpi 
radialis longior or radialis brevior of man ; it 
has a broad origin from the inner border of 
the humerus above the epicondylus medialis. 
It becomes narrower as it passes downwards 
to be inserted by a tendon into the os 
semilunare and uaviculare. The muscle is 
much stronger in males than in females, 
and the crest from which it takes origin is 
correspondingly larger in the former sex 
(p. 42). Tendinous fibres connect it with 
the following muscles : — 


Muscles of the right arm of 58. M. flexor carpe JHE 8. ulnaris (Fig. 


Rana esculenta. 


oe / 
ed M. extens. digitorum com- 74. Fe ). 
munis, 


ei M.abductor digiti II longus. Dugès, epitrochlo-carpien, n. 84. 
‘a! ‘4 ¢ ibrachii 1: ve . = 
Enr eatibeachi later This muscle represents the flexor carpi 
alis superficialis. 3 ; : cg 
Fe M. flexor carpi radial. ulnaris or ulnaris anterior , and is close to 


Fe’ M. flexor carpi ulnar, . 5 : . 

Fd M. flexor digitorum com. the inner side of the foregoing. It arises 

tr Tendon of the M. sterno. 120m the epicondylus medialis, being con- 
radialis. nected by fibres with the fleror digitorum 


communis, and is inserted into the os naviculare. 


MUSCLES OF THE ANTERIOR EXTREMITY, - 89) 


59. A1. flexor digitorum communis (Figs. 75, 76, 77 Fd). 
Dugès, epitrochlo-sous-phalangettien, n. 118. 

This muscle lies most internally, and corresponds to the m. flexor 
digitorum sublimis of man, It arises in common with the foregoing 
muscle from the epicondylus medialis, and runs downwards to the 
palm of the hand. At its entrance into this it diminishes and 


passes into the flat aponeurosis palmaris. (See hand, B.) 


60. I. flexor antibrachii medialis (Ecker), (Fig. 75 Fa). 
Dugès, epitrochlo-sous-radial, n. 79. (Frequently described as the pro- 


nator rotundus, a description which cannot be retained, as the implied 
movement does not occur in the frog.—Kcker. ) 


This muscle lies deeply on the inner side of the forearm, covered 
by the flexores carpi; it arises tendinously from the epicondylus me- 
dialis and is inserted into the inner surface of the radial side of the 
radio-ulnar as far as the inferior articular extremity. 


61. MW. flexor antibrachu lateralis su- Fig. 75. 
perficialis (Ecker), (Figs. 74, 75 Fa’). 
Dugés, premier ex-huméro-radial, n. 76. 
(Usually described as supinator longus, 
this, for reasons similar to those in the 
case of m. flexor antibrachii medialis, 
cannot be retained.) 


The situation of this muscle corresponds 
with that of the swpinator longus of man ; 
it lies to the outer side of the tendon of 
the m. sternoradialis, and arises by two 
heads, the one, above from the outer edge 
of the humerus, the other deeper from the 
epicondylus lateralis, They unite and pass 
into a tendon which, running over the 
lower articular extremity of the radio- | 

] . +t] ttached to th i ] Muscles of the right arm of Rana 
ulnar, is partly attached to the carpus anc bte doen nee 
partly connected with the tendon of the ca Extensor digit. communis. 
ay t r digits IT vroprius L » Fr Fa Flexor antibrachii medialis. 
m. extensor digiti IT proprins longus. From  xy Flexor antibrachii lat. super 
‘ ae Re = a ficialis. 
its position and insertion, this muscle Fa” Flexor antibr. lat. profundus. 
evidently flexes the forearm and extends fe Flexor carpi radialis. 


Fe’ Flexor carpi ulnaris. 
the hand. Fd Flexor digitorum communis, 


62. M, flexor antibrachii lateralis profundus (Ecker), (Fig.7 5 Fa”). 


Dugès, epicondylo-sus-radial, n. 78.—Klein, flewor antibrachti. (Su- 
pinat. brevis autt.) 


This muscle arises under cover of the foregoing, from the epicon- 
dylus lateralis of the outer surface of the humerus, it becomes 


86 THE MUSCLES. 


broader and is inserted into the whole length of the lower (volar) 
ridge of the radio-ulnar. It is a powerful flexor of the forearm. 


(IL) Muscles of the extensor surface. 


63. I. extensor digitorum communis longus (Fig. 75 ed). 
Dugés, huméro-sus-digital, n. 95. 

This muscle lies on the outer border of the forearm ; it arises in 
common with the short head of the flewor antibr. lateralis superfici- 
alis from the epicondylus lateralis, and from the surface above it ; 
it runs downwards along the outer side of the forearm, in order to 
pass into an aponeurosis on the back of the hand, which expands 
upon the third, fourth, and fifth fingers, and ends between them in 
a free concave border. This aponeurotic expansion is connected 
with the tendons of the extensor brevis digitorum. 


63*. M. abductor digiti IT (1. e. pollicis) longus (Fig. 74 ei). 
*Dugés, cubito-métacarpien, n. 87. 
This muscle lies between the foregoing and the flexor antibrachi 
lateralis superficialis, and appears superficially m the interval between 
Fig. 76. them. It arises from the lateral surface of the 
radio-ulnar, and runs obliquely over the m. flexor 
antibrachu lateralis profundus and the hinder 
extremity of the radio-ulnar towards the second 
finger into the metacarpal bones of which it is 
inserted. 


64. A1. extensor carpi ulnaris s. ulnaris post. 
(Fig. 76 ec). 
Dugès, epicondylo-sous-carpien, n. 85.—Klein, 
abductor carpi internus. 

This muscle has a somewhat narrow origin 
from the epicondylus lateralis ; during its course 
through the forearm, where it lies between the 
mm. anconaet on the one side and the extensor 
digitorum communi on the other, it becomes 


Muscles of forearm of broader and is inserted into the outer surface of 
Rana esculenta, dorsal 


view. the carpus in the following manner. By one 
aa M. anconaei, tendinous slip it is attached to the palmar 
ec M. extens. digit. : . 

st border of the os pyramidale, by a second slip 


Fa tex. Ge. to the outer border of the os capitato-hamatum. 


This latter slip is usually connected in its dorsal portion with the 
extensor digitorum communis brevis. 


MUSCLES OF THE ANTERIOR EXTREMITY. 87 


65, 66. I. anconaei s. extensores antibrachii (Fig. 76 aa). 
Dugès, epicondylo-cubital and epitrochlo-cubital, n. 80, 81. 

Both these muscles lie on the extensor side of the forearm ; they 
spring, the one from the epicondylus lateralis, the other from the 
epicondylus medialis ; converging, they run downwards, enclose the 
olecranon, and are inserted into the upper (dorsal) border of the 
ulna, each forming a penniform muscle. They are extensors of the 
forearm and assist the m. triceps. 


C. Muscies or tHE HAN». 
(L) Muscles on the palmar surface. 
(1) Muscles common to all the digits. 


67. MW. flexor digitorum communis and in. palmaris brevis (Fig. 
77 fi, pb). 

The origin and course of this muscle has been described above. 
At its entrance into the palm it suddenly diminishes in size and 
passes into a triangular aponeurosis, aponeurosis palmaris. Into the 
outer border of this aponeurosis is inserted the m. palmaris brevis 
(Fig. 77 pb) ; this latter muscle arises from the posterior or ulnar 
border of the lower extremity of the radio-ulnar below the insertion 
of the mm. anconaei, and runs obliquely downwards to this insertion. 

From the lower free border of the aponeurosis a number of 
muscles arise which will be described with the rest of the digital 
muscles. . 


(2) Muscles of the rudimentary thumb, 
68. M. abductor pollicis (Figs. 77, 78 ap). 


Dugès, cubito-pollicien, n. 100. 
This short muscle arises from the upper border of the lower 
extremity of the radio-ulnar, passes transversely outwards, and is 
then inserted into the anterior border of the rudimentary thumb. 


69. MW. adductor pollicis (Figs. 77, 78 ad.p). 
Dugés, sous-carpo-pollicien, n. 101. 

This lies more superficially than the last, it arises from the 
palmar surface of the os capitato-hamatum, and is inserted together - 
with the abductor pollicis into the thumb. Several fibres of the 
extens. dig. IT brevis are also inserted into the thumb. As this 
member is completely covered with skin, the motions of which it 
is capable are very limited. 


88 THE 


MUSCLES. 


(3) Muscles of the second finger, which serves the purposes of a 


thumb. 


70. M. flewor digiti IT longus s. sublimis (Fig. 77 f2). 


Dugès, sous-carpo-phalangettien de l’index, n. 133. 


This is a flat muscle, which arises for the most part by fleshy 
fibres from the hinder free border of the aponeurosis palmaris, also 


Muscles of hand of Rana esculenta, volar 
surface, larger than nature. 


A Aponeurosis palmaris. 
abs M. abductor dig. V primus. 
abs’ M. abductor dig, secundus. 
ac MM. anconaei, 
adp M. adductor pollicis, 
ap M. abductor pollicis, 
M. extensor digitorum communis, 
M. extens, dig. commun. brevis. 
J2 M. flexor dig. II longus. 
M. flexor dig, IIT longus. 
M. flexor dig. IV longus, 
ts M. flexor dig. V longus. 
fb2 M. flexor dig. II brevis. 
Jb3 and fb3! MM. flexores dig. III breves, 
Jb4 and fb4’ MM. flexores dig. IV breves. 
Jb5 M. flexor dig. V primus, 
J4 M. flexor digitorum communis. 
0 M. opponens. 
pb M. palmaris brevis. 
I First finger, rudimentary thumb. 
II Second finger, functions as thumb. 
III-V Third to fifth fingers. 


Fig. 78. 


Second layer of muscles on volar surface of 


hand of Rana esculenta, larger than nature. 


abs M. abductor dig, V primus. 

abs’ M. abductor dig, V secundus. 
ad2 M. adductor dig. II. 

ad.p M. adductor pollicis. 

ap  M. abductor pollicis. 

cc M. extensor carpi. 

fb2 M. flexor dig. II brevis. 

fb2’ M. flexor dig. IT tertius. 

fp MM. flexores proprii phalangum. 
ww MM. interossei volares. 

a5 

0 M. opponens dig. II. 

o’ M. opponens dig, V. 

tt’ MM. transversi metacarpi. 
I-V as in Fig. 77. 


by a smaller part from the palmar surface of the os capitato- 
hamatum. It quickly passes into a thin long tendon which is 
inserted into the terminal phalanx of the thumb (second finger), 


MUSCLES OF THE ANTERIOR EXTREMITY. _89 


71. A. flexor digiti IT brevis s. profundus (Fig. 77 2). 
Dugès, sous-carpo-phalangien de l'index, n. 102. 

This flat muscle, covered by the preceding, has a tendinous origin 
from the palmar surface of the os capitato-hamatum, together with 
one head of the flexor sublimis, and is inserted into the basal 
phalanx. 


72. M. fleror digiti LI tertius (Fig. 78 fb2’). 
Dugès, tendini-phalangien de l’index, n. 103. 
A small, thin muscle which arises close to the foregoing from the 
os capitato-hamatum, and is inserted into the basal phalanx (see 
below, m. interosseus volaris I). 


73. M. adductor digiti II (Fig. 78 ad2). 
Dugés, métacarpo-métacarpien de l’index, n. 90. 
This muscle represents the adductor pollicis of man ; it arises from 
the base of the third os metacarpal and is inserted into the metacarpal 
of the second finger, which latter it draws towards the third finger. 


74. M. opponens digits IT (Figs. 77 and 78 0). 
Dugès, sous-carpo-métacarpien de l’index, n. 90. 

This muscle represents the muscle of like name in man. It arises 
from the palmar process of the os capitato-hamatum by a narrow 
tendon and passes into a broad, flat muscle, which is inserted into 
the under surface and outer border of the metacarpal of the second 
finger throughout its length. It has, undoubtedly, the same action 
as the corresponding muscle in man. 


(4) Muscles of the third finger. 

75. M. flewor digiti LIT longus s. sublimis (Fig. 77 £3). 

The smaller portion of this muscle arises from the free border of 
the aponeurosis palmaris, the chief portion, together with the jlexor 
brevis, from the palmar surface of the os capitato-hamatum. The 
two portions pass into one long tendon, which is inserted into the 
last phalanx. 

76, 77. MM. flewores digiti LIT breves s. profundi I, IT (Fig. 
77 fb3 and 703’). 
Dugès. tendini-phalangiens du medius, n. 104, 105. 

These two muscles arise in part from the free border of the 2p0- 
neurosis palmaris, in part from the volar surface of the os capitato- 
hamatum, and pass backwards on either side of the muscle last 
described, to be inserted into the basal phalanx. Dugès regards 
these as analogues of the mm. /umbricales. 


90 THE MUSCLES. 


78. M. flexor metacarpi dig. IL. 
This is a somewhat strong muscle, which arises by fleshy fibres 
from the palmar surface of the os capitato-hamatum, and is inserted 
into the palmar surface of the metacarpal bone. 


(5) Muscles of the fourth finger. 

79. M. flexor digiti IV longus s. sublimis (Fig. 77 74). 

It arises at the free border of the aponeurosis palmaris, and 1s 
inserted into the terminal phalanx by a thin tendon. 

80, 81. WM. flewores digiti IV breves s. profundi I, IT (Fig. 
77 fo4 and fo4’). 
Dugés, tendini-phalangiens de l’annulaire, n. 108, 100. 

Dugés regards these also as analogues of the m. /wmbricales; they 
arise on either side of the foregoing muscle from the free border of 
the aponeurosis palmaris, and are inserted by tendons into the basal 
phalanx. 

82. M. flexor proprius phalangum dig. IV (Fig. 78 fp). 
Dugés, phalango-phalangien, n. 115. 

A small muscle which arises by two slips from the palmar surface 
of the basal phalanx, and is inserted into the base of the middle 
phalanx. 


83. M. flexor metacarpi dig. IV (Fig. 78 74). 
This somewhat strong muscle arises from the os capitato-hamatum, 
and is inserted into the palmar surface of the metacarpal bone. 
(6) Muscles of the fifth finger. 
84. M. flexor dig. V longus s. sublimis (Fig. 77 f5). — 
This corresponds exactly with the corresponding muscle of the 
fourth finger. 
85. M. flewor dig. V brevis (Fig. 77 f05). 
This muscle arises from the free border of the aponeurosis and 
is inserted into the basal phalanx. 


86. M. flexor proprius phalangum dig. V (Fig. 78 fp). 
Dugès, phalango-phalangien, n. 17. 
It corresponds exactly with the corresponding muscle of the 
fourth finger. 


87. M. opponens dig. V (Fig. 78 0’). 
Dugès, deuxième sous-carpo-métacarpien du digitule, n. 92. 


This muscle has a narrow origin from the palmar surface of the 


MUSCLES OF THE ANTERIOR EXTREMITY. 91 


os capitato-hamatum, it widens and is inserted into the outer border 
of the metacarpal of the small finger. It draws this finger towards 
the thumb. 


88. WM. abductor dig. V primus (Figs. 77 and 78 ab5). 
Dugès, sous-pyro-pré-métacarpien du digitule, n. 93. 
This muscle arises from the palmar border and the outer surface 


of the os pyramidale, and is inserted into the basal phalanx by a 
thin tendon. 


89. WM. abductor dig. V secundus (Figs. 77 and 78 ab5’). 
Dugès, sous-pyro-post-métacarpien du digitule, n. 94. 
It arises from the posterior part of the os pyramidale, is short, 
and is inserted into the outer side of the metacarpal. 


(II.) Muscles on the dorsal surface. 


M. extensor digitorum communis longus (Figs. 75 ed and 77 ec). 


90. MW. extensor digitorum communis brevis (Fig. 79 e3, e4, e5). 
Dugès, sous-pyro-phalangettien du III, IV, V, n. 124, 128, 131. 

Covered by the foregoing, this muscle arises from the os pyra- 
midale in conjunction with the extensor pollicis and from the os 
capitato-hamatum. The part destined for the third finger, together 
with that for the fourth, arises from the os pyramidale, passes 
obliquely backwards into a tendon which runs along the inner side 
of the corresponding finger to be inserted into the last phalanx. 
That for the fifth finger arises from the inner projection of os 
capitato-hamatum bemg here attached to the insertion of the m. ex- 
tensor carpi ulnaris, and is inserted in a similar manner into the 
terminal phalanx of the fifth finger. 


91. MW. abductor digiti IT (i.e. pollicis) longus (Figs. 74 ei and 
79 ab.2). 

For the origin and course of this muscle in the forearm see 
No. 63. The muscle passes obliquely over the wrist-jomt from 
the little finger towards the inner side and from before backwards, 
it is inserted into the metacarpal of the second finger (thumb). 
The place of insertion of this muscle into the metacarpal (compare 
p. 47) is, in the males, developed into a ridge and process, the 
muscle itself is enlarged during the breeding season. This muscle 


abducts the thumb and by this means presses upon the chest of the 
female when clinging to her. 


92 THE 


MUSCLES, 


92. M. extensor digiti IT proprius longus (Fig. 79 e2, ¢2’). 


Dugès, cubito-radio-sous-phalangien de l'index, n. 96. 


This muscle lies obliquely on the back of the hand, parallel 


Fig. 70. 


Muscles of hand of Rana esculenta. Dorsal 
view, twice natural size. 


ab.z, M. abductor dig. II longus, 
ab.2' M. abductor dig. IT brevis. 
ad2 M. adductor dig. II. 


rb t M. extensor dig. II longus. 
e2 


3 M. extensor digitorum communis 

4 J brevis. 

es 

eb2 M. extensor dig. II proprius 
brevis. 

ec M. extensor carpi ulnaris. 

fa M. flexor antibr. lat. superficial. 

3 

d'4 ji. interossei. 

i's 

II-V as in Fig. 77. 


with the m. abductor digiti II, It 
arises by two heads, one from the 
tendon of the flexor antibr. lat. 
superf. (n. 60) upon the hinder ex- 
tremity of the radio-ulnar. This 
tendon conceals the hinder end of 
this bone by means of a patella-like 
thickening, and sends forth three 
tendinous prolongations; of these, 
the one is attached to the ulnar 
border of the radio-ulnar, the second 
to the os naviculare, while the third 
constitutes that portion of the #. 
extens. dig. II proprius long. which 
is under consideration. The second 
head arises from the os pyramidale 
in connection with the extensor digi- 
torum communis brevis (n. go). The 
heads unite to form a long muscle, 
which runs obliquely towards the 
second finger, passes into a tendon, 
which, after forming’ connections 
by some muscular fibres with the 
metacarpal, is inserted into the ter- 
minal phalanx. 


93. IM. extensor dig. LI proprius brevis (Fig. 79 eb2). 
Dugès, sus-luno-phalangettien de l'index, n. 120. 

This muscle lies between the preceding muscle and the abductor 
dig. IT longus. It arises from the os xaviculare, and also includes 
some fibres which arise from the second metacarpal. The tendon 
runs along the radial side and is inserted along with the last 
muscle into the terminal phalanx. 


94. M. abductor dig. IT brevis (Fig. 79 ab.2’). 
Dugés, sus-luno-métacarpien de l’index, n. 88. 
This represents the abduct. pollic. brevis of man, lies on the outer 
side of the hand, arises from the os xaviculare, and is inserted into 


the second metacarpal. 


MUSCLES OF THE ANTERIOR EXTREMITY. 93 


95. MW. extensor dig. ILI proprius. 
Dugés, sus-luno-phalangettien du médius, n. 122. 

This muscle has two heads of origin, from the os naviculare and 
lunatum. These form one muscular belly, which rapidly diminishes 
and passes into a tendon; this, after receiving a few muscular 
fibres from the second metacarpal, runs to the outer part of the 
dorsal surface of this finger as far as the terminal phalanx, where it 
is inserted. 


96. M. extensor dig. IV proprius. 
Dugés, sus-pyro-phalangettien de l’annulaire, n. 128. 

By a somewhat broad base, this muscle arises from the os navi- 
culare and lunatum. The tendon receives fibres from the fourth 
metacarpal and runs on the outer half of the dorsal surface of this 
finger as far as the middle phalanx, where it is inserted. 


(LIL) MM. interossei. 
97, 98. [a.] IM. transversi metacarpi (Ecker), (Fig. 78 t,t’, ad2). 
These lie transversely between the metacarpals. There are three ; 
the first has been already described as m. adductor digiti II (n. 73) ; 


the second is stretched between the third and fourth metacarpals, 
and the third between those of the fourth and fifth fingers. 


99, 100, 101. [b.] IM. interossei volares. 

One may regard as such, four long, thin muscles, which take 
origin near one another on the palmar surface of the carpal bones, 
and diverge from this towards the second and fifth fingers. 

1. The first of these muscles (Fig. 78 42’) has already been 
_deseribed above as the m. flexor digiti LI tertius (n. 72). 

2. The second (Fig. 78 73) passes from the origin already de- 
scribed to the palmar surface of the basal phalanx of the third 
finger. 

3. The third (Fig. 78 74) runs, in like manner, to the fourth 
finger. 

4. The fifth (Fig. 78 75) to the fifth finger !. 


102 to 108. WAI. interossei dorsales. 


These arise in common from the metacarpals, and are inserted 
into the basal phalanx of the corresponding surface on the finger. 


* Whether these muscles may be regarded as mm. interossei is open to discussion, 
as they appear to act more as mm. opponentes. 


94 THE MUSCLES. 


1. The ¢hird finger has two, one to the radial side (Fig. 79 73), 
one to the ulnar side. 

2. The fourth finger has three, the third (Fig. 79 #4) arises from 
the carpus, and perhaps ought rather to be regarded as an extensor. 


3. The fifth finger has two. 


IV. MUSCLES OF THE HINDER LIMB. 


I. Musczes oF THE THIGH. 


General arrangement (Figs. 80, 81). 

a. The m. triceps femoris forms the outer border of the thigh, and 
extends on to both the dorsal and ventral surfaces. The outer 
border therefore corresponds with the anterior surface of the thigh 
of man, in consequence of the thigh in the frog being normally 
rotated outwards. 


b. The m. vastus internus (v.7.) and a portion of the adductor longus 
(ad’), the sartorius (s), a portion of the adductor magnus (ad’”’), and 
the rectus internus major (7.7) are found on the cnner surface of the 
thigh. 

e. The rectus internus minor (r.1”) forms the inner border. 


d. On the dorsal surface are to be seen, nearest the trunk, the 
glutaeus (gl), on the outer border the vastus externus (v.e.), the pyri- 
formis and biceps (p and 4), then the sewimembranosus (sm), and lastly 
the rectus internus minor (77). 

e. By reflecting the rectus internus major (compare Fig. 82) there 
are exposed to view: the semitendinosus (st), the whole length of 
the adductor longus, magnus (ad’ and ad”), and brevis (ad”). By re- 
flecting the triceps, one sees (Figs. 84, 85) the i/io psoas (ip), and 
beneath the semimembranosus, the quadratus (qf), and capsularis 
femoris (09). 

Description of the separate Muscles. 

(A.) Muscles of the dorsal surface. 

109. MW. glutacus (Fig. 80 g/). 
Dugés, ex-ilio-trochantérien.— Zenker, glutaeus maior. 


The tendinous origin of this muscle is found on the outer surface 
and upper border of the two hinder thirds of the iliac bone. Thence 
it runs outwards and backwards between the head of the m. vastus 
externus (ve) on the one side, and the i/io-psoas and rectus anticus (ra) 


MUSCLES OF THE 


on the other, to be inserted 
into a tubercle (trochanter) 
of the femur. 

110. WM. Pyriformis (Fig. 
80 p). 

Cuvier, pyramidal.— Dugès, 
cocey-fémoral, n. 136. 

A narrow, slender muscle, 
arising from the apex of the 
coccyx; it passes obliquely 
outwards and backwards to 
the thigh, to be inserted deep- 
ly between the m. vastus exter- 
nus and the biceps, into the in- 
ner surface of the femur, but 
towards the ventral surface. 

M. triceps femoris s. exten- 
sor cruris communis (Fig. 80). 
Dugès, pelvi-fémoro-rotulien, 

n. 145, 146, 147. 

This is à large, strong 
muscle, having three heads 
of origin, and inserted by a 
tendon into the tibio fibula. 
The three heads are the caput 
longum ox the rectus femoris 
anticus (r.a.), the caput exter- 
num or the vastus externus(v.e.), 
and the caput internum or the 
vastus internus (Fig. 82 vi); of 
these, the first is situated 
on the outer border of the 
thigh, the second on the dor- 
sal surface, and the third on 
the ventral surface. 

111. [a.| UW. rectus femoris 
anticus (Figs. 80, 82 ra). 

This arises from the under 
(ventral) surface of the iliac 
bone about its middle and 
beneath the m. glutaeus. 


Muscles of left thigh of Rana esculenta. 


b 
ci 


g 
gl 
p 
pe 


read. 


vil! 


sm 


ta. 


tr. 


v.e. 


HINDER LIMB. 


The muscular belly quickly passes 


RE 


95 


Dorsal view. 


. biceps. 

. coccygeo-iliacus. 
. gastrocnemius. 
. glutaeus. 


pyriformis. 
peroneus. 


. rectus anterior, 

. Tectus internus minor. 
. semimembranosus. 

. tibialis anticus. 

. triceps fem. 

. vastus externus, 


into 


96 THE MUSCLES. 


an aponeurosis, which covers the other two muscular masses and 
combines with their tendons. 


112. [b.| 17. vastus externus (Fig. 80 v.e.). 
It arises from the upper and hinder extremity of the iliac bone 
(Fig. 42 #7”) behind the g/utaeus, which here sinks in between this 
muscle and the rectus anterior. 


113. [c.] MW. vastus internus (Figs. 81, 82 vi). 

It arises from the whole of the under and outer surfaces of the 
hip-joint capsule, and from tendinous slips which pass from this 
capsule downwards on the under surface of the muscle, (from the 
pubis and the femur I have not seen any fibres of origin, as stated 
by others). Anteriorly the vastus may easily be separated into two 
heads. The two vasti unite and form one muscular belly, in the 
formation of which, as above stated, the rectus anticus takes no 
part. This united muscle passes into a tendon which, without the 
mediation of a patella, passes over the knee-joint to be inserted into 
the anterior extremity of the tibio fibula, and is prolonged into the 
fascia of the lee. 


114. MW. clio-fibularis s. biceps (Fig. 80 4). 
Dugés, ilio-péronien, n. 149.—Zenker, flexor externus tibiae, p. 42. 

This is a long, somewhat narrow muscle, which les to the inner 
side of, and partly covered by, the vastus externus, between which 
and the semimembranous it is placed. Itarises by a tendon between 
the t/io-psoas and pyriformis from the ilium above the acetabulum 
and behind the origin of the vastus eaternus. From here it passes 
backwards, separated from the vastus externus by a strong ligam. 
intermusculare. On the inner side of this muscle, between it and 
the ». semimembranosus, run the vessels of the thigh and the J. . 
ischiadicus. The muscle then divides into two portions, of which 
one is inserted high up on the inner and under surface of the 
femur. This is probably the muscle which Klein (7 ¢., p. 61) 
describes as the extensor brevis. The other long muscular belly 
passes into a thin tendon, opposite the hinder extremity of the 
thigh, it divides into two portions; the anterior is inserted into 
the dorsal surface of the hinder extremity of the femur, the other 
into the dorsal surface of the tibio-fibula. Between the two is 
stretched an arch with the concavity outwards. This insertion of 
the biceps is covered by the stronger tendon of origin of the m. gas- 
trocnemius (compare Fig. 87). 


MUSCLES OF THE HIND LIMB. 97 


115. I. semimembranosus (Figs. 80, 86 sm). 


Dugés, sus-ischio-poplité, n. 148.—Klein, p. 60, extensor femoris 
sublimis. 


This muscle lies on the dorsal surface of the thigh, to the inner 
side of the diceps and pyriformis : it is a broad muscle, which takes a 
tendinous origin from the hinder and upper angle of the symphysis 
ossis ilei, and is inserted by a flat tendon into the dorsal surface 
of the ligaments of the knee-joint, and through these into the 
tibio-fibula. The tendon is formed rather abruptly from the muscle, 
and is surrounded (Fig. 86) by the concave arch, which forms 
the tendon of origin of the gastrocnemius (g.v.). A little behind 
its middle (compare Fig. 81) the muscle is divided-obliquely into an 
anterior and a posterior portion by an aponeurotic septum. As 
all the fibres are interrupted by this structure, the muscle may 
very easily be torn through. 


(B.) Muscles on the ventral surface. 
116. M. sartorius (Figs. 81, 82 s). 
Dugés, sous-iléo-tibial, n. 150.—Klein, gracilis. 

This long, flat muscle lies along the middle of the ventral surface 
of the thigh ; it arises by a tendon from the anterior inferior angle 
formed by the symphysis of the innominate bones, and ter- 
minates in a tendon behind the knee-joint, forming a kind of 
pes anserinus in the fascia of the leg, similar to that of the sewi- 
tendinosus \. 


117. MW. rectus internus major (Ecker), (Figs. 81 7.7’, 82 77’). 

Dugès, post-ischio-tibial profond, n. 152.— Klein, semimembranosus. 
This is a broad and flat muscle, thinned out at either extremity ; 
it occupies the inner half of the ventral surface of the thigh, and is 
in relation with the adductor magnus externally and anteriorly, with 
the sartorius posteriorly, and the rectus minor muscle internally. 
The muscle arises by a tendon from the pubic symphysis ; 
it covers in its course the semitendinosus, then passes into a 
strong tendon, which blends with the tendon of the rectus 
minor, to be inserted by a slip into a process of the tibio-fibula 
representing the ¢werositas tibiae, first passing between the ten- 
dons of the sartorius and semimembranosus, which here form an 
aponeurotic arch; a second slip passes under the tendon of the 


' The sartorius has lately been used by Kühne in his researches on the nerve- 
endings in muscle and on muscle contraction without nerve supply (du Bois-Rey- 
mond’s and Reichert’s Archiv, 1859. Page 314). 


I 


98 


THE MUSCLES. 


Fig. 81. 


Muscles of left thigh of Rana esculenta. Ventral surface. 


ad’ M. 
ad” M. 
ad!” M. 
ec. M. 
. flexor tarsi. 

A gastrocnemius. 

_ rectus internus major. 
. rectus internus minor. 
. sartorius. 

. tibialis anticus. 

. tibialis posticus. 

. vastus internus. 


2teeeBSee 


adductor longus, 
adductor brevis. 
adductor magnus. 
extensor cruris. 


m. semitendinosus to 
be inserted into the 
upper surface of the 
tibio-fibula, under it 
passes the A. tibialis. 
A third thread - hke 
tendon passes to the 
m.  semimembranosus, * 
Somewhat behind its 
middle (Fig. 82) the 
muscle is traversed by 
an inscriptio tendinea, 
by which the whole of 
the fibres are inter- 
rupted. 


118. WM. rectus in- 


ternus minor (Licker), 


(Figs. 80, 81 md Vos 
Dugès, post-ischio-tibial 
superficiel, n. 151.— 
Zenker, fleror tibiae 
magnus.—Klein, is- 
chio-tibialis. 
Situated entirely on 
the inner surface of 
the thigh, this narrow 
muscle arises by 2 
tendinous band which 
runs the whole length 
of the pubie symphy- 
sis, and is connected 
posteriorly with the 
sphincter ani, anterior- 
ly with the rectus 
abdominis ; posteriorly 
it passes into a thin 
tendon which is also 
connected with the 
muscle just described 
(ang) in its course 


MUSCLES OF THE HIND LIMB. 99 


this muscle is attached to the skin by strands of vessels and con- 
nective tissue. 

The vastus internus major and minor together undoubtedly 
correspond with rectus internus or gracilis of human anatomy. 
The rectus internus major is, however, regarded as corresponding 
with the adductor magnus by Dugés, and with the semimembra- 
nosus by Klein; by considering the position and attachments of 
these muscles one must arrive at a different conclusion. 


MM. adductores femoris. 


119. [a] 27. adductor longus (Fig. 
82 ad’). 

Dugès, sous-ilio-fémoral, n. 141. 

Without further dissection this 

muscle is only partially visible be- 
tween the m. sartorius and vastus 
internus (Fig. 81 ad’). The muscle 
is flat and long, and arises by a 
tendon from the anterior inferior 
angle of the pubic symphysis (Fig. 
42 s), partially covered by the 
origin of the sartorius. Thence the 
muscle passes between the vastus 
internus and the adductor magnus, 
and finally is inserted below the 
middle of the femur, together with 
the latter muscle. 


120. [b] IW. adductor magnus 
(Figs. 81, 82 ad”). 


Dugés, sous-ischio- pubi-fémoral (ad- 
ductor I and 2), n. 142, 143.— 
Klein, adductor magnus and ex- 
tensor femoris profundus. 


Muscles of the left thigh of Rana esculenta. 
Ventral surface. 


ad’ M. adductor longus. 


This muscle is visible between the ae? Wh Side 


sartorius and rectus internus major eh acy 

s A 3 ip M. ilio-psoas. 

in the anterior half of the thigh, ra M. rectus fem. anticus. 
“ M rectus int. major. 

posteriorly it is covered by these LÉ ir rat 

muscles. It arises by a tendon Re dr pa a 


vi M, vastus internus. 


from (a) the pubic symphysis and 
ischii, and is in this position divided into two portions, between 
H 2 


100 THE MUSCLES. 


which passes the tendon of one head of the m. semitendinosus (Fig. 
83 st”); (4) a second part arises from this same tendon (Fig. 83 st”) 
and joins with the first part. Thus formed the muscle passes to be 
inserted into the distal half of the inner surface of the femur as 
far as the condyle. Near its hinder extremity, however, it passes 
on to the dorsal and outer surfaces, and thus forms a kind of 
muscular sheath surrounding the distal portion of the bone. 


121. [ce] 27. adductor brevis (Figs. 81, 83 ad”), 
and 
122. [a] IW. pectineus (Fig. 83 pe). 


Dugès, sous-pubio-fémoral (analogue of the pectineus, possibly of the 
add. brevis also). 


These two small muscles which lie under cover of the sartorius, adduc- 
tor longus and magnus, 
appear externally as one 
muscle, but may easily be. 
separated (Fig. 83). They 
arise close together from 
the pubic symphysis, and 
are inserted into the 
inner surface of the an- 
terior half of the femur. 
They are not attached to 
the adductor magnus. 


Fig. 83. 


123. J. semitendinosus 
(Fig. 83 st, st’, st”). 
Dugès, bis - ischio - tibial, 
n. 153. — Zenker, bi- 
ceps. 

This is a long thin mus- 
cle, only visible after re- 
moval of the m. rectus 
internus, by which it is en- 


Deep muscles of left thigh of Rana esculenta. 


ad’ M. adductor longus. 


ad” M. adductor brevis. tirely covered. It arises 
ad” M. adductor magnus. ‘ 

Be ir ainahoas: by two long thin tendaae 
pe M. pectineus. one (caput posticum, st’) 


M. 
ra M. rectus anticus. 

vi’ M. rectus internus maior 
vi’ M. rectus internus minor 
s M. sartorius. 


from the pubic symphysis, 


} cut through. : 
the other (caput anticum, 


st Belly of m. semitendinosus. — st’ 4 from the hollow be- 
st’ M. semitendinosus (cap. posticum). : 

st” M. semitendinosus (cap. anticum). tween the symphysis and 
st”! Fibres passing into the adductor magnus. 

ogee tk a rae, Fa | the acetabulum. Thelatter 


MUSCLES OF THE HIND LIMB. 101 


passes through a slit in the adductor magnus, and so affords this 
muscle another point of origin; then backwards between the 
adductor magnus and the rectus internus major and under the lower 
third of the thigh, and unites with the posterior head of origin. The 
muscle so formed passes into a thin tendon, and, together with that 
of the sartorius, forms an aponeurotic arch, connected with the fascia 
of the leg, under which the tendons of the rectus internus major and 
minor pass. 


(C.) Deep muscles of the thigh. 


To these, in addition to the adductor brevis, pectineus, and the 
portion of the dcceps already described, belong also the following : 


124. M. iio-psoas (Figs. 82, 83, 84 ip). 
Dugés, intra-ilio-fémoral (=iliacus and psoas).—Cuvier, Zenker, 
Klein, tliacus internus. 
The fibres of this muscle take a broad origin from the pelvic 
surface of the ilium, pass outwards over the lower margin of the 


Fig. 84. 
Fig. 85. 


Deep muscles of the left thigh of Rana 
esculenta. Dorsal view. 


ad’ M. adductor brevis. 


ci M. coccygeo-iliacus, Left half of pelvis of Rana escu- 
cx Coccyx. lenta. Thigh turned forwards 
gt M. glutaeus. under the abdomen. 


il Tleum, 

ip M., ilio-psoas. 

0.9. M. obturatorius. 

gf M. quadratus femoris. 


gl M. glutaeus. 
og M. obturatorius. 


bone and form a flat muscle with its apex pointed posteriorly. It 
crosses the hip-joint between the m. rectus and vastus internus, 


102 THE MUSCLES. 


covering the hinder part of the m. glutaeus, and is inserted into the 
outer surface of the middle third of the femur. 


125. MW. quadratus femoris (Fig. 84 ¢f). 


Dugès, post-ilio-fémoral (Homologue of the glutaeus maximus), n. 197.— 
Zenker, glutaeus minor, p. 42. 


This muscle is of a somewhat elongated, triangular shape, and 
arises, under cover of the pyriformis, from the ilium behind the ace- 
tabulum ; it passes backwards over the joint to be inserted into the 
inner and under surfaces of the femur, between the pyriformis and 
ilio-psoas ; below, it is in direct relation with the adductor brevis. 


126. JL. obturatorius (Figs. 84, 85 04). 

Dugès, ischio-pubi-fémoral, n. 139 (?).—Zenker, m. capsularis femoris. 
This small muscle is deeply situated upon the hip-joint, and 
covered by all the other muscles that arise from the symphysis. Its 
origin from the innominate bone extends from the superior posterior 
angle of the symph. ossis iii to about the middle of the pubic sym- 
physis ; the muscle fills the space between the crest of the sym- 
physis. and the acetabulum. The fibres converge to pass into a 
strong tendon, which is inserted into the posterior and anterior 
surfaces of the head of the femur. The muscle appears to represent 
collectively the small rotators of human anatomy, m. obturator ex- 

ternus and internus and the gemelli. 


IJ. Muscies or THE Lee. 
General description. 

On the outer surface (the anterior of man), covered by the fascza 
cruris, into which the tendon of the eatensor communis cruris or 
triceps is prolonged, are found the following muscles : nearest to the 
bone, the m. extensor cruris brevis (ec); externally, the m. tidialis 
anticus (ta) and the m. peroneus (pe). On the inner surface (the 
hinder of man) lie the gastrocnemius (gc) and tibialis posticus (tp), and 
deeply the flexor tarsi sup. (ft). 


127. M. gastrocnemius (Figs. 80, 81, 86). 
Dugés, bi-fémoro-plantaire, n. 159. 

This important muscle arises by two tendinous heads. The one 
(Fig. 86 yg’) rather nearer the middle line of the popliteal space, is 
by far the stronger: it arises by a broad, tendinous expansion, 
which covers the knee-joint, and is attached to the femur and the 
tibio-fibula by anterior and posterior bands respectively ; it ends 


MUSCLES OF THE HIND LIMB. 103 


internally in a concave aponeurotic arch: the second head is a thin, 
tendinous slip, -arismg from the common tendon of the ¢riceps as 
this lies on the knee-joint. The muscle is thickest near its origin, 
and then gradually diminishes in size as it passes backwards; the 
superficial surface is convex, the deep surface is flat. By tracing the 
tendons of origin, they are seen soon to unite and form a common 
flat tendinous surface, broad in front, 
contracted behind ; this aponeurosis 
hes in a plane running obliquely 
from the deep surface towards the 
superficial surface, without, how- 
ever, reaching this. The muscular 
fibres arise from both surfaces of the 
aponeurosis, the fibres of the two 
sides diverging slightly as they pass 
backwards so as to be inclined at a 
small angle to each other. The 
fibres are inserted into a fibrous ex- 
pansion (4y) which hes on the su- 
perficial surface of the muscle; thin 
and slight in front, this aponeurosis 
rapidly thickens posteriorly until it 
passes into the ¢endo Achillis. 

128. MW. tibialis posticus (Fig. 
86 {.p.). 

Dugès, cruro-astragalien, n. 160. 


Covered by the gastrocnemius this 


Muscles of the right leg and foot of Rana esculenta. 
Dorsal view. 

ah. M. abductor hallucis. 

ax M. abductor longus digiti I. 

A.p. Aponeurosis plantaris. 

b M. biceps. 

et, M. extensor tarsi. 

FI. M. flexor digitorum III, IV, V longus. 

Fl’, M. flexor digitorum I and II longus. 


g M. gastrocnemius, drawn towards the right. 
g Tendon of origin of gastrocnemius. 

lec.  Ligamentum calcanei. 

D M. plantaris. 


7. MM.internus maior and minor, 
sm. M. semimembranosus, 

s.t. M. semitendinosus. 

t.A. Tendo Achillis. 

t.A’, Thickening of tendo Achillis. 
tp. M. tibialis posticus. 

ve. M. vastus externus. 

at M. vastus internus. 


104 THE MUSCLES. 


muscle occupies the whole of the inner and upper surfaces of the 
tibio-fibula, from which it arises by numerous fibres. Opposite the 
hinder extremity of the bone the muscle becomes free and passes 
somewhat abruptly into a tendon, which courses behind and over the 
malleolus internus, on to the dorsum of the foot, and is here inserted 
into the anterior extremity of the astraga/us. I cannot agree with 
Dugès that this muscle corresponds with the so/eus (Ecker). 


129. I. extensor cruris brevis (Fig. 87 ec). 
Dugès, pré-fémoro-tibial, n. 154. 

Covered by the strong fascia cruris, and lying between the #. #i- 
bialis anticus and the tibio-fibula, this muscle arises by a long tendon 
from the inner condyle of the femur; it passes backwards in the 
groove on the anterior extremity of the tibio-fibula, covered by the 
tendon of the triceps femoris, and is then inserted by muscular 
fibres into the outer surface of the tibio-fibula almost as far as the 
posterior third of the bone. (Dugès regards this muscle as the 
upper, 1.e. anterior, portion of the ¢ibia/is anticus.) 


130. 1]. tibialis anticus (Figs. 80, 81, 87 ta). 

Dugès, pré-fémoro-astragalien and pré-fémoro-calcanien, n. 156 and 157; 
the former he regards as one part of the ¢ib. anticus, the latter 
as the peroneus longus I.—Zenker, tib. ant. biceps. 

The tendon of origin of this muscle is attached to the femur near 
the tendon of the m. extensor cruris brevis, and to the joint-ligaments. 
The muscle is placed under the fascia cruris, its long tendon of 
origin passing beneath the tendon of the ériceps in a special sheath 
through the joint ; the tendon then gains a muscular belly which 
bifurcates at about the middle of the leg, forming two muscular 
masses, coursing along the outer and the inner side of the leg re- 
spectively. The latter is inserted into the dorsal surface of the astra- 
galus by a tendon, and the former into the dorsal surface of the 
calcaneus 1n a similar manner. The muscle extends the foot and 
flexes the tarsus ; the latter movement is very distinct on account of 
the insertion of the muscle being so near the hypomochlion. 


131. I. flewor tarsi anterior (Ecker), (Fig. 87 Ft). 
Dugés, ex-tibio-astragalien, n. 155.—Zenker, tibialis anticus simplex. 
This muscle arises where the insertion of the extensor cruris brev 
ceases, from the middle of the under surface of the tibio-fibula, and 
passes backwards between the two tendons of the m. tibialis anticus 
along the outer side of this muscle, to be inserted by a tendon 


MUSCLES OF THE -HIND LIMB. 105 


into the inner side of the anterior 
articular extremity of the as/ra- 
galus and the fascia dorsalis pedis. 


132. J. peroneus (Figs. 80 pe, 
87 p). 


Dugès, génio-péronéo-calcanien, 
n. 158. 
à g 


. . . . ec 
This is a strong muscle whichis ta 


attached by a long tendon of origin 
to the hinder extremity of the pp 
femur and the ligaments of the 
knee-joint. The tendon runs in a 
sheath through the jomt and pos- 
teriorly becomes muscular; the 
muscle passes downwards on the 
outer side of the tibio-fibula to be 
inserted into the mad/eolus externus 

of this bone and into the anterior > 
extremity of the ca/caneus. It has 
an action similar to that of the 
m. tibialis anticus. 


Ft 


Z 
AY KR 
rx 
~ 

» 


te 


| 


III. Muscies or THE Foor. 
A. Muscreson THE PLANTAR SURFACE. 


133. Aponeurosis plantaris 
(Fig. 88 A.p.). 
= As already mentioned, the ten- 
don of the m. gastrocnemius is, at 
the heel, continued into a strong 
aponeurosis, and possesses at this | 
place a thickening !. The aponeu- \ 
rosis 1s of triangular form, the  Muscies of leg and foot of Kana esculenta, 
base directed towards the toes and pa as 

a.b.5 M. abductor dig. V longus. 

attached to these. The lateral ec M. extensor cruris brevis. 


. . e.d.1 M. extensor digit I longus. 
borders of this triangle are con- e.d.4 M. extensor digit IV longus. 
tinued into weaker fasciae, which a ee 

¢ Ft M. flexor tarsi anterior. 
are attached to the two long tarsal Ft M. flexor tarsi posterior. 
: pe gM. gastrocnemius. 
bones. The inner border in par- None, 


ticular Iv sa on oO a ta M. tibialis anticus. 
Sve strong bundle of tF M. triceps femoris. 


? Lehmann, Ueber den Knorpel in der Achillessehene des Frosches, Zeitschs. f. 
U. Zool. XIV, p. 109. (See also literature on cartilage, Sect. VII.) 


106 


THE MUSCLES. 


fibres to the astragalus, and is thus connected with the fascia of the 
dorsum of the foot; externally this aponeurosis is attached to a 
cartilage (Duges, os sesamoïde, /. c., n. 66), situated on the plantar 
surface of the joint between the calcaneus and the os metatarsi IV. 


134. Ligamentum calcanei (Ecker), (Figs. 88, 89 /.c.). 
If the tendo Achillis be divided and the aponeurosis plantaris 


Fl. 


reflected towards the toes, there is 
seen, arising from the posterior head 
of the tibio-fibula, im its whole 
breadth, a ligament (between the 
lib. posticus and peroneus). This 
ligament forms a firm surface on 
which the thickened portion of the 
tendo Achillis may move, and which 
evidently represents the tuberosity 
of the heel bone. I have there- 
fore named the entire structure the 
ligamentum calcanet. 

Several muscles arise from this 
ligament, viz. :— 


135. I. extensor tarsi (Klein), 
Figs. 88, 89 e.t.). 

Dugès, tibio-sous-astragalien (regarded | 
by him as the homologue of the 
tibialis posticus). 

Covered by the two succeeding 
muscles, this muscle arises from the 


Muscles of the right leg and foot of Rana esculenta. 
Dorsal view. 

ah, M. abductor hallucis. 

a.lx M. abductor longus digiti I. 

A.p. Aponeurosis plantaris. 

b M. biceps. 

et. M. extensor tarsi. 

EL M. flexor digitorum III, IV, V longus. 

EX, M. flexor digitorum I and IT longus. 


g M. gastrocnemius, drawn towards the right. 
J Tendon of origin of gastrocnemius, 

Le. Ligamentum calcanei. 

p M. plantaris. 

ri MM. internus maior and minor. 

sm.  M.semimembranosus. 

st, M. semitendinosus. 


1... Tendo Achillis. 

1.4’, Thickening of tendo Achillis. 
tp. M. tibialis posticus, 

Ul. M. vastus externus. 

Lire M. vastus internus. 


MUSCLES OF THE HIND LIMB, 107 


ligamentum calcanei, runs backwards, and is inserted into the whole 
length of the plantar surface of the astraga/us. It extends the foot. 


136. M. plantaris (Figs. 88, 89 p). 
This takes its origin from the /igamentum calcanei to the inner side 
and below the last muscle. It passes backwards and is inserted 
into the dorsal surface of the aponeurosis plantaris. 


137. M. flexor digitorum IT, IV, V longus (Kicker), Figs. 88, 

89 F.1.). 
Dugès, péronéo-sous-phalangettien ( flexor dig. longus). 
This muscle also arises Fig. 89. 

from the ligamentum cal- 
canei to the outer side of 
the m. plantaris. It runs 
backwards over the apo- 
neurosis plantaris, and at 
the free margin of this 
passes somewhat  sud- 
denly into a strong ten- 
don, which traverses an 
aponeurotic canal, formed 
by fibres of the aponeu- 
rosis passing above and 
below the tendon, from 


Muscles of the plantar surface of foot 
of Rana esculenta, twice natural 
size. 


A.p, Aponeurosis plantaris, divided. 

ab.5. M. abductor dig. V. 

ad.s. M. adductor dig. V. 

ad.l.x. M. adductor longus dig. 1. 

el. M. extensor tarsi. 

F.5. M. flexor brevis dig. V. 

FJ. M. flexor digitorum III, IV, V 
longus. 

FU. M. fiexor digitorum I, IT longus. 


dc, Ligamentum calcanei. 

pM. plantaris. 

t.4, Tendo Achillis, 

t.A’, Thickening in tendo Achillis. 

t.p. M. transversus plantae poste- 
rior, 

, M. transversus plantae anterior, 


108 THE MUSCLES. 


the cartilaginous enlargement in the tendon to the median border 
of the aponeurosis. The tendon forms three slips for the fifth, 
fourth, and third toes: these are slightly attached to the aponeurosis, 
but reach beyond its free border to be inserted into the terminal 
phalanges of the toes mentioned, and are held down by fibrous 
bands. (The small #. /xmbricales arismg from these tendons are de- 


scribed below.) 


138. M. flexor digitorum I, II longus (Kicker), (Figs. 88, 89 F7). 

The tendons, by means of which the terminal phalanges of the 

first and second toes are flexed, arise directly from the posterior 
border of the aponeurosis. 


139, 140. ILM. transversi plantae (Ecker), (Fig. 89 £.p., t.p’.). 

The movements of the aponeurosis and through it the move- 

ments of the tendons attached to it are influenced not only by 

the m. gastrocnemius and plantaris, but also by two other muscles, 

which together have been described as the flexor dig. longus internus 
(Klein), or as the tarso-sous-phalangettien (Dugès, 221). 


a. M. transversus plantae posterior (t.p.). 


This takes its origin from the plantar cartilage, widens as it 
courses backwards and inwards to be inserted into the dorsal 
surface of the aponeurosis plantaris; from this the tendons for 
the first and second toes (jlewor dig. longus I and 17) arise, thus there 
is no direct connection between the muscular fibres of the two 
muscles. 


b. MW. transversus plantae anterior (t.p’.). 


This muscle is covered by the last ; broader anteriorly, it arises 
from the caleaneum, and is inserted to the inner side of the last 
muscle into the dorsal surface of the aponeurosis. This muscle, 
hike that just described, is not continued directly into the tendon 
of the flexor of the toes, they cannot therefore be regarded as 
flexors of the toes. 


141 to 149. Musculi lumbricales (Fig. 89 L.1-5). 
(A.) From the posterior border of the aponeurosis plantaris arise :— 
(1) MW. lumbricalis digiti I (1.1). 
Dugés, tendini-sous-phalangien de pouce, n. 185. 


This is inserted into the anterior extremity of the proximal 
phalanx. 


MUSCLES OF THE HIND LIMB. 109 


(2) MW. lumbricalis digitt IT (1.2). 
Dugès, tendini-sous-phal. du I doigt, n. 186 (and 187), double according 
to Dugès. 


Similarly inserted. 


(3 and 4) MAT. lumbricales digiti IT (1.3). 
Dugés, tendini-sous-phal. du III doigt, n. 188, single according to 
Dugès. 


One of these (/3) is inserted into the anterior extremity of the 
basal phalanx, the other (/3’) into a corresponding position on the 
middle phalanx. 


(5) M. lumbricalis digiti IF. 
Dugès, tendini-sous-phal. du IV doigt. 


Inserted into the anterior extremity of the basal phalanx. 


(B.) Arising from the tendons of the flexor longus ILI, IV, V : 
(6 and 7) MM. lumbricales digiti IV (1.4’. and 1.4”.). 
Dugès, tendini-sous-phalanginien du IV doigt, n. 201, 202. 


The first (¢.4’) is inserted into the posterior end of the basal pha- 
lanx, the second (/.4”) in a similar position into the second phalanx. 


(8) A. lumbricalis digiti V (1.5.). 
Dugés, tendini-sous-phalangien du V doigt, n. 203. 
This arises from the tendon for the fifth toe, runs backwards as a 


thin tendon alongside that of the flexor, and is inserted into the 
middle phalanx. 


Special Muscles of the Separate Toes. 
(I.) Muscles of the rudimentary great toe. 
150. M. abductor hallucts (Figs. 88 a.h., 90). 
Dugès, tibio-sous-tarsien, n. 163. 


This muscle arises from the mner border of the aponeurosis plan- 
taris, at the spot where the m. plantaris is inserted, it may therefore 
almost be regarded as a continuation of this muscle; it is inserted 
into the anterior border of the rudimentary toe. 


(IL) Muscles of the great and first toes. 
151. WM. adductor longus digiti I (Figs. 89, 90 ad./1). 
Dugès, calcanéo-scaphoidien, n. 164. 
This powerful muscle arises from the plantar surface of the cal- 
caneum and astragalus ; its fibres converge towards a tendon lying in 


110 THE MUSCLES. 


its middle, which becomes free towards its posterior end; the 
tendon passing inwards under the ligamentum tarsi transversum 
through a groove on the hinder extremity of the astragalus in an 
arched direction, to be inserted into the os navicu/are, which bears 
the rudimentary great toe and the os metatarsi I. 


(III.) Muscles of the first toe. 
152. MM. abductor longus digiti I (Figs. 88 al.1, go a.b.1). 
It takes its origin from the inner border of the aponeurosis plan- 
‘aris, and lies on the plantar surface of the abductor hallucis. Its 


tendon runs in the hollow which the great toe forms, and is in- 
serted into the inner side of the os metatarsi I. 


153. M. flexor brevis digiti I (Fig. go Fb.1). 

A small, thin muscle, which arises from the anterior extremity 
of the os metatarsi IT, and is inserted into the basal phalanx of the 
first toe. In this small muscle, and also in the m. lumbrical. dig. V 
(Fig. 89 7.5.), the nerve distribution may be very well seen. 


154. MM. opponens dig. I (Fig. go op). 
Dugès, sous-metatarso-phalangien du pouce, n. 192. 

This is situated to the inner side of the preceding muscle, arises 
from the os metatarsi IT somewhat narrow, widens in a fan-like 
manner towards the os metatarsi I, into the anterior half of which it 
is inserted. 


(IV.) Muscles of the second toe. 
155. M. flexor metatarsi dig. II (Fig. 90 F.m.2). 


Dugés, sous-tarso-metatarsien du II doigt.—Klein, extensor metatarsi. 
By a narrow origin from the hinder end of the calcaneum, poste- 
riorly this muscle becomes broader and is inserted, somewhat thinned 
out, into the plantar surface of the second os metatarsi. 


156. M. flewor dig. II proprius (Fig. go Fp.2). 
Dugès, sous-metatarso-phalangien, n. 194. 

It arises from the plantar surface of the os metatarsi IT, and is 
inserted by a thin tendon into the plantar surface of the first 
phalanx. 

Dugès describes this and the analogous muscles of the third, 
fourth, and fifth toes (77.3, 4, 5) as the interossei plantares, a no- 


MUSCLES OF THE HIND LIMB. tit 


menclature which, to me, does not appear correct, as these muscles 
he entirely on the plantar surface, and do not adduct or abduct the 
toes, but flex them. 


Fig. go. 


(V.) Muscles of the third toe. 


157. MW. flew. metatarsi dig. 

III (Ecker), (Fig. 90 F.m.3). 
Dugès, sous-calcaneo-métatar- 
sien du III doigt, n. 174.— 

Klein, extensor metatarsi. 
Like the corresponding 
muscle of the second toe 
(n. 155), this arises by a small 
tendon from the hinder ex- 
tremity of the calcaneum, runs 
backwards and is inserted into 
the plantar surface of the os 
metatarsi III. The greatest 
portion of the muscle lies be- 
neath the mm. transversus meta- p.74 Are (4 \ 
tarsi (tm), the most anterior maw À \) 

) 


portion, however, lies above 
this. Dugés has described 


A 
this latter portion as a special Fatt | 
muscle (n. 176, metatarso- Vs 
métatarsien du III), the same 
description holds good for the 


second toe (n. 177, Dugès). 


HS 


158. MW. flewor dig. IUT 
proprius (Ecker), (Fig. 91 Fp3). 


Dugés, sous-métatarso-phalan- \ 
gien du IIT doigt, n. 195. 


=) — = Muscles of plantar surface of foot of Rana esculenta. 
Like the corresponding as 
a.b.1 M. abductor longus digiti I. 


muscle of the second toe, abs M. abductor digiti V. 


this arises from the plantar ad.l,: M. adductor longus digiti Lie 
a.h.  M. abductor hallucis. 


surface of the os metatarsi III,  Fbr M. flexor brevis digiti I. 


sus 5 F.m.2, 3, 4 M. flexores metatarsi II, III, LV. 
and 1s inserted by a thin tendon F.p.2, 3, 4, 5 MM. flexor. proprii digit. 2, 3, 4, 5. 


into the plantar surface of the  F#.3,4, 4, 5 MM. flexor. phalang. digit. 3, 4, 5. 
. A op M. opponens digiti I. 
anterior extremity of the first — tm’ ) 


tm” -MM.t tat 
ph al anx. er je ransversi metatarsi 1, 2, 3. 


112 THE MUSCLES. 
159. A1. flexor phalangum proprius digiti IIT (Ecker), (Fig. gt 
Fph.3). 


Dugès, phalango-phalangien, n. 204. 


This arises by tendon from the plantar 


‘Muscles of plantar surface of foot of Rana esculenta. 


a.b.x M. abductor longus digiti I. 

abs M. abductor digiti V. 

ad./.1 M. adductor longus digiti I. 

ah. M. abductor hallucis. 

F.b.1 M. fiexor brevis digiti I. 

F.m.2. 3, 4 M. flexores metatarsi IT, III, 1V. 
F.p.2, 3, 4, 5 MM. flexor. proprii digit. 2, 3, 4, 5. 
F.ph.3, 4, 4’, 5 MM. flexor. phalang. digit. 3, 4, 5. 
op M. opponens digiti IL. 

t.m’ 

tm! pu. transversi metatarsi 1, 2, 3. 

tn 


surface of the basal 
phalanx, and is inserted into 
the anterior extremity of the 
terminal phalanx. 


(VI.) Muscles of the fourth 

toe. 
160. MW. flexor metatarsi 
dig. IV (Fig. 91 F.m.4). 
Dugés, métatarso-métatarsien, 
n. 175. 

Similarly to the correspond- 
ing muscle of the third toe, 
this one arises from the 
hinder extremity of the calca- 
neum, and is inserted into the 
anterior portion of the plantar 
surface of the os metatarsi IF, 
but not into the greater portion 
of this surface, as in the second 
and third os metatarsi. 


161. WW jlevor digas 
proprius (Fig. 91 Fp4). 

Dugès, sous-métatarso-phalan- 
gien du IV doigt (interosseus 
plantaris), n. 196. 

The origin and insertion are 
similar to those of the muscles 
of the second and third toes. 


162. M. flexor brevis dig. 
1e 
A small muscle, which arises 
with the m. flexor brevis of the 
fifth toe, from enlargement of 
aponeurosis plantaris, and is in- 
serted into the basal phalanx 
of the fourth toe. 


MUSCLES OF THE HIND LIMB. 113 


163. 11. flexor phalangum proprius dig. IV anterior (Fig. 91 
Fph.4). 


Dugès, phalango-phalanginien, n. 205. 


It resembles the corresponding muscle of the third toe. 


164. M. flexor phalangum proprius posterior (Fig. 91 F.ph.4’). 
Dugés, phalangino-phalangettien, n. 209. 
This extends from the plantar surface of the second phalanx to 
the anterior extremity of the third. 


(VII) Muscles of the small toe. 
165. JM. abductor dig. V (Fig. gt a.h.5). 
Dugés, calcanéo-ex-métatarsien du digitule, n. 169. 


This muscle arises from the hinder extremity of the calcaneum, 
and is inserted into the outer surface of the fifth metatarsal. 


166. A. adductor dig. V (Fig. 89 a.d.5). 
Dugès, sous-tarso-in-phalangien, n. 191. 
This arises from the cartilage of the plantar aponeurosis, and is 
inserted into the hinder end of the fifth metatarsal. 


167. MW. flexor brevis dig. V (Fig. 89 F5). 
Dugès, sous-tarso-ex-phalangien, n. 190. 
Arising from the same place as the preceding, it extends to the 
basal phalanx. 


168. M. flexor dig. V. proprius (Fig. 91 F.p.5). 


(Analogues of Muscles, n. 156, 158, 161; see note at n. 156).—Dugès, 
sous-métatarso-phalangien, n. 197 (=inteross. plant.). 


This muscle arises from the plantar and inner surfaces of the fifth 
metatarsal, and is inserted into the basal phalanx. 


169. M. flexor phalangum proprius (Fig. 91 F.ph.5). 
Dugès, phalango-phalanginien, n. 206. 
Its origin and insertion are as in the corresponding muscles of the 
second, third, and fourth toes, n. 159, 163, 164, 169. 


170 to 172. MM. interossei (Fig. 91 t.m.). 
Dugès, 1, 2, and 3, intermétatarsien, n. 170, 171, 172. 
These are three muscles with their fibres arranged transversely, 
which occupy the anterior portion of the spaces between the 
I 


114 THE MUSCLES. 


metatarsals, and approximate these. The first arises (tm’) from the 
edge of the plantar surface of the first metatarsal, and is inserted 
into the corresponding part of the second: the second (¢m’’) passes 
from this point to the third, and the third (¢m’”’) to the fifth. 


B. Muscres or roe Dorsar SURFACE. 
173. M. flexor tarsi posterior (Ecker), (Fig. 92 Ft.). 
Dugés, péronéo-sus-astragal, n. 161. 
This is a strong muscle, which has a narrow origin from the 
outer side of the tibio-fibula, directly over the distal extremity, and 


is inserted into the dorsal surface of the astragalus from the middle 
to the distal extremity. 


Muscles of the first toe. 
174. M. extensor longus dig. I (Fig. g2 e.l.1). 


Dugès, calcanéo-sus-métatarsien du pouce, n. 166. 

This lies to the outer side of and near the foregoing muscle; it 
arises by a long, strong head from the middle of the calcaneum, runs 
obliquely backwards and inwards to unite with a small head which 
arises from the common epiphysis of the astragalus and caleaneum, 
in common with the m. extensor dig. IT. The muscle so formed 


passes into a flat tendon to be inserted into the basal phalanx of 
the first toe. 


175. M. extensor brevis dig. I (Fig. 92 ¢.0.1). 


A small, short muscle which arises from the os naviculare and is 
inserted into the dorsal surface of the first metatarsal. 


176. IM. abductor brevis dig. I (Fig. 92 a.b.1). 
Dugés, ex-tarso-métatarsien du pouce, n. 168. 
This small muscle is situated near the preceding; it arises from 


the first bone of the supplemental toe, and is inserted into the inner 
side of the first metatarsal. 


Muscles of the second toe. 


177. M. extensor dig. II longus (Fig. 92 e./.2). 
Dugés, calcanéo-sus-phalangien du IT doigt, n. 182. 
This arises from the caleaneum, in common with the m. extensor 


longus of the third toe, and is inserted into the basal phalanx of the 
second toe by a tendon. | 


MUSCLES OF THE 


178. M. extensor 
dig. II brevis (Fig. 92 
e.b.2). 


Dugès, astragalo-sus- 
phalangien du II, 
n. 183. 

This is partly covered 
by the preceding muscle : 
it arises from the astra- 
galus, and unites with 
the tendon of the pre- 
ceding muscle. 


Muscles of the third 
toe. 


179. M. extensor 
dig. IIT longus (Fig. 92 
¢.0.3). 
Dugès, sus-astragalo- 
phalangien du mé- 
dius, n. 199. 

This arises with the 
extensor longus of the 
second toe from the 
calcaneum : its tendon 
unites with that of the 
following muscle. 


180. MM. extensor 
dig. III brevis (Fig. 92 
e.b.3). 
Dugès, astragalo-sus- 
phalangien du mé- 
dius, n. 181. 

This muscle arises 
from the astragalus, 
and is inserted with the 
tendon of the preceding: 
muscle into the dorsal 
surface of the basal pha- 


lanx. 


HIND LIMB. 169 


Fig. 92. 


Dorsal view of muscles of foot of Rana esculenta. 


a.b.r M. 
e.b.xr M. 
e.b.2 M. 
e.b.3 M. 
e.b.4 M. 
e.b.4 M. 
e.b.5 M. 
e.l.r M. 
e.l.2 M. 
el.3 M. 
e.l.4 M. 
e.l.5s M. 


abductor brevis dig. I. 
extensor brevis dig. I. 
extensor brevis dig. II. 
extensor brevis dig. III. 
extensor brevis 1 dig. IV. 
extensor brevis 2 dig. IV. 
extensor brevis dig. V. 
extensor longus dig. I. 
extensor longus dig. II. 
extensor longus dig. III. 
extensor longus dig. IV. 
extensor longus dig. V. 


Ft M. flexor tarsi posterior, 
1.2 to à ro MM. interossei. 


10? 


116 THE MUSCLES. 


Muscles of the fourth toe. 
181. MW. extensor longus dig. IV (Fig. 93 ¢./.4). 
Dugés, péroneo-sus-phalangien du IV, n. 178. 
A narrow muscle arising in common with the flexor tarsi inf. 
but external to it. It is inserted into the tendinous expansion on 
the dorsum of the toe. 


182. MM. extensores dig. IV breves (Fig. 93 e.b.4 and e.b.4”). 


Dugés, calcanéo-sus-phalangien and sus-calcanéo-phalanginien, n. 179 
and 198. 


These two small muscles arise from the calcaneum : one is in-: 
serted into the basal phalanx, the other, by means of à long 
thin tendon, passes along with the tendon of the corresponding 
m. interosseus to the second phalanx, to which it is attached. 


Muscles of the fifth toe. 

183. A. extensor dig. V longus (Fig. 93 ¢.1.5). 
Dugès, calcanéo-sus-métatarsien, n. 165. 

A strong muscle which covers almost the whole length of the 
caleaneum ; it arises from the anterior extremity of this bone, runs 
backwards to the outer side of the dorsum of the foot, and is 
attached to the outer surface of the fifth metatarsal. 


184. M. extensor dig. V brevis (Fig. 93 e.b.5). 
Dugès, calcanéo-sus-phalangien du V, n. 180. 
This is a long thin muscle, which, together with the muscle last 
described, arises from the calcaneum and is inserted into the basal 
phalanx of the fifth toe. 


185. MM. abductor dig. V brevis (Fig. 93 7.10). 
This, the last m. interosseus, arises from the outer side of the 
fifth metatarsal, and is inserted into the hinder extremity of the 
second phalanx of the same toe. 


186 to 195. AIM. interossei dorsales (Fig. 93 7.1 to 2.10). 


First toe. 
(1) The analogue of the first m. interosseus is the m. abductor 
brevis dig. I (a.b.1). 
(2) The second m. txterosseus (i.2) arises from the outer side of 
the first metatarsal, and is inserted into the outer surface of the 


second phalanx of the same toe, dorsally to the m. opponens and 
flexor brevis dig. I. 


MUSCLES 


Second toe. 

(3) The third m. w- 
terosseus(i.3)takesorigin 
from the anterior part 
of the outer surface of 
the first metatarsal by 
a thin tendon; it is 
inserted into the inner 
surface of the second 
phalanx by à similar 
tendon. 

(4) The fourth #. #- 
terosseus (7.4) arises from 
the outer side of the 
second metatarsal, and 
is Inserted into the outer 
surface of the second 
phalanx. 


Third toe. 

(5) The fifth #. m- 
terosseus arises from the 
outer surface of the 
second metatarsal, and 
is inserted by a thin 
tendon into the inner 
surface of the second 
phalanx of the same 
toe. 

(6) The sixth arises 
from the outer surface 
of the third metatarsal, 
and is inserted laterally 
by a thin tendon into 
the hinder extremity of 
the second phalanx of 
the same toe. 


Fourth toe. 


(7) The seventh m. cn- 
lerosseus (7.7) arises by a 
thin tendon from the 


OF THE HIND LIMB, 


ar 


| 


Dorsal view of muscles of foot of Rana esculenta. 


a.b.1 M. 
. extensor brevis dig. I. 

I. extensor brevis dig. IT. 

. extensor brevis dig. III. 

. extensor brevis 1 dig. IV. 
I. extensor brevis 2 dig. IV. 
. extensor brevis dig. V. 

. extensor longus dig. I. 

. extensor longus dig. IT. 

. extensor longus dig. III. 
. extensor longus dig. IV. 
. extensor longus dig. V. 

. flexor tarsi posterior. 


Fig. 93. 


abductor brevis dig. I. 


i.2 to 4.10 MM. interossei. 


ja 


118 


e.l.5 


e.b.5 


THE MUSCLES. 


AR 
Wan 
al 


Dorsal view of muscles of foot of Rana esculenta. 


a.b.r M. 
e.b.r M. 
e.b.2 M. 
e.b.3 M. 
e.b.4 M. 
e.b.4 M. 
e.b.s M. 
e.l.z M. 
e.l.2 M. 
el.3 M. 
e.l.4a M. 
e.l.s M. 


abductor brevis dig. I. 
extensor brevis dig. I. 
extensor brevis dig. IL. 
extensor brevis dig. III. 
extensor brevis 1 dig. IV. 
extensor brevis 2 dig. IV. 
extensor brevis dig. V. 
extensor longus dig. I. 
extensor longus dig. IT. 
extensor longus dig. III. 
extensor longus dig. IV. 
extensor longus dig. V. 


Ft M. flexor tarsi posterior. 
i.2 to i.10 MM. interossei. 


hinder extremity of the 
astragalus, and by fleshy 
fibres from the hinder 
extremity of the fourth 
metatarsal ; it is inserted 
by a thin tendon into 
the inner surface of the 
second phalanx of the 
same toe. 

(8) The eighth m. i- 
terosseus (7.8) takes its 
origin from the outer 
surface of the fourth 
metatarsal and from the 
inner surface of the fifth : 
it is inserted into the 
hinder extremity of the 


. second phalanx. 


Fifth toe. 

(9) The ninth m. m- 
terosseus (2.9) arises from 
the inner surface of the 
fifth metatarsal, and is 
inserted into the hinder 
extremity of the second 
phalanx. 

(10) The tenth m. i- 
terosseus has already been 
described as the abductor 
digiti V brevis (Fig. 94 
2.10). 

If we take the 
fourth toe as the axis 
of movement, the first, 
third, fifth, seventh, 
eighth, and tenth mm. 
interossei will abduct 
from an imaginary line 
which runs through this 
toe. The second, fourth, 


MUSCLES OF THE SKIN. 119 


sixth, and ninth will adduct towards this line. If we compare 
them with those of man (in whose case the second toe affords the 
central line), those of the first group must be regarded as mm. inter- 
ossei dorsales, of the latter as plantares. Duges holds all these 
interossei (with the exception of the first, abductor brevis dig. 1) to 
be mm. interossei dorsales (métatarso-sus-phalangettiens, n. 210, 211, 
212, 214, 215, 216, 218, 219). Those which I have described as 
flexores propri digitorum, he regards as iaterosser volares. 


V. MUSCLES OF THE SKIN. 


196. I. cutaneus pectoris (Fig. 95 cp). 


Dugès, abdomino-guttural, n. 53.— Klein, abdomino-cutaneus.—Zenker, 
subcutaneus pectoris. 


This is an elongated quadrangular muscle, attached by its hinder 
margin to the side of the xiphisternum, and to the superficial 
surface of the aponeurosis of the m. obliquus externus. The fibres 
course forwards and 
slightly outwards to be Fig. 95. 
inserted, at a very acute 
angle,into the skin: lying 
between the two muscles 
and attached to them on 
either side is a thin fas- 
cia, which, together with 
the muscles and the sep- 
tum thoracicum, assists in 
closing a triangular space 
between these structures 
and the deeper muscles. 

The thinness and trans- 
parency of this muscle 
render it especially suit- , 

5 5 5 cp M. cutaneus pectoris. 
able for the investigation p’”’ Port. abdominalis of the m. pectoralis. 
of nerve-terminations 1. 


197. MW. cutaneus dorsi (Fig. 96 cd). 
Dugès, pubio-dorso-cutané, n. 56.—Zenker, cutaneus iliacus. 


This muscle has à narrow origin in the space between the muscles 


Pectoral region of Rana esculenta. 


1 Kolliker, Mikrosk. Anatomie, 1866, vol. II. 1, p. 247; Reichert, Miiller’s Archiv, 
1851, p. 29, Pl. 1; Külliker, Untersuchungen über die letzten Endigungen der Nerven 
in den Muskeln des Frosches ; Leipzig, Engelmann, 1862. 


120 


THE MUSCLES. 


of the belly and of the thigh, and is here inserted into the fasciäe, 
which are attached to the pubie symphysis; it passes inwards and 


Hind portion of back and thigh of Rana esculenta. 


cd 
cx, 
gl. 
H 
oe 
nf 


sm 


Fig. 96. 


M. cutaneus dorsi. 

Coccyx. 

M. glutaeus. 

Skin reflected to left side. 
M. obliquus externus. 

M. rectus femoris anterior. 
M. semimembranosus, 


ve M. vastus externus. 


upwards to the outer side of 
the anterior insertion of the 
m. rectus femoris anticus, then 
widens and is inserted by di- 
verging fibres into the inner 
surface of the skin of the 
hinder portion of the back. 


198. J. coccygeo-cutaneus. 
Dugés, coccy-dorso-cutanés, 
us Bile 

The muscular fibres which 
Dugès has described under 
this name, lie covered by the 
m. pyriformis, behind the m. 
coccygeo-iliacus, ete., and above 
the muscles of the rectum. 
They arise from the hinder 
extremity of the urostyle: 
they appear to be connected 
with the rectal muscles, and 
pass outwards to be attached 

to the skin. 


Among the cutaneous muscles may perhaps be included the 
m. submaxillaris (p. 62). 
The fibrils passing from the flexor tendons to the warty bodies 
on the plantar surface of the toes are described! with the skin 


(p. 373). 


! Compare Klein, Beïträge zur Anatomie der ungeschwänzten Batrachier (R. tem- 
poraria, L.) : Jahreshefte des Vereins für vaterländische Naturkunde in Wiirttemberg, 
1850, p. 72. 


SECTION III. 


THE NERVOUS SYSTEM. 


THE NERVOUS SYSTEM. 
LITERATURE. 


Ahlborn, F., Ueber die Bedeutung der Zirbeldriise. Zeit. f. wiss. Zool. 1884. 
Vol. XL, pp. 331-337. 

Allen, H., The Spinal Cord in Batrachia and Reptilia. Proc. Acad. Nat. Sci. 
Philadelphia. 1883, pp. 56-57. 

Arndt, A. W., Untersuchungen über die Ganglienkôrper des Nervus sympathicus. 
Arch. f. mikrosk. Anat. 1874. Vol. X, pp. 208-241. 

Arndt, R., Untersuchungen über die Endigung der Nerven in den quergestreiften 
Muskelfasern. Arch. f. mikrosk. Anat. 1873. Vol. IX, p. 481. 

Arndt, R., Untersuchungen über die Ganglienkürper der Spinalganglien. Arch. f. 
mikrosk. Anat. 1875. Vol. XI, p. 140. 

Arnold, J., Zur Histologie der Lungen des Frosches. Virchow’s Arch. 1863. 
Vol. XXVIII, p. 433. 

Arnold, J., Histologische Verhältnisse des Frosch-Sympathicus. Centralbl. f. d. 
med. Wiss. 1864, p. 657. 

Arnold, J., Ueber die feineren histologischen Verhältnisse der Ganglienzellen 
in dem Sympathicus des Frosches. Virchow’s Arch. 1865. Vol. XXXII, 
(ds Ue 

Arnold, J., Die Spinalfasern im Sympathicus des Frosches. Arch. f. Anat. und 
Physiol. 1866, p. 398. 

Arnold, J., Das Gewebe der organischen Muskeln. Leipzig, 1869 ; and Chap. IV 
in Stricker’s Handbook. 

Arnstein, C., and Gonjaew, K., Ueber die Nerven des Verdauungskanals. Bericht. 
f. Physiol. u. Histologie. Mittheilung. aus. d. 4 Vers. wissensch. Naturforsch. zu 
Kasan. Pflüger’s Arch. d. ges. Physiol. 1874. Vol. VIII, pp. 614-615. 

Aubert, H., Die Innervation der Kreislaufsorgane, Hermann’s Handbuch der Phy- 
siologie. Leipzig, 1880. Vol. IV, Pt. I, p. 377. 

Axmann, De Gangliorum systematicis structura persitiori eiusque functionibus. 
Berolini, 1847. 

Axmann, Beiträge zur mikroskopischen Anatomie und Physiologie des Ganglien- 
nervensystems. 1853, p. 20. 

Baculo, B., Nuove ricerche intorno l’apparechio ganglionare intrinseco dei cuori 
linfatici. Naples, 1885. 

Balfour, F. M., Treatise on Comparative Embryology. London, 1880. 

Balfour, F. M., Handbuch der vergleichenden Embryologie. Aus dem Englischen 
von B. Vetter. Jena, 1880. 3 

Beale, L. S., On the Structure and Formation of the so-called Apolar, Unipolar, 
and Bipolar Nerve-cells of the Frog. Phil. Trans. 1863, p. 543. (Hyla 
arborea.) 

Beale, L. S., Further observations in favour of the view that nerve-fibres never end 
in voluntary muscle. Proc. Roy. Soc. 1863. Abstract in Quart. Journ. Micros. 
Sci. 1863. Vol. XII, p. 668. 

Beale, L. S., New observations upon the structure, etc. of certain nervous centres. 
Proc. Roy. Soc. 1860. Vol. ITT. 

Beale, L. S., On the Distribution of Nerves to the elementary fibres of Striped 
Muscle. Phil. Trans. 1864, p. 611. 


LITERATURE. 125 


Beale, L. S., Of very fine nerve-fibres ramifying in certain fibrous tissues and 
trunks, and plexuses consisting entirely of very fine nerve-fibrés in the bladder 
of the frog. Beale’s Archives of Medicine, 1864. Vol. IV, pp. 19-251. 

Beard, J., The Ciliary or Motor-oculi ganglion and the Ganglion of the ophthalmicus 
profundus in Sharks. Anatom, Anzeiger. 1887. Vol. II, p. 565. 

Beck, K., Zur Kenntniss der Herznerven. Arch. f. mik. Anat. 1885. Vol. XXIV, 
pp. 11-19. 

~ Bellonci, G., Intorno alla struttura e alle connessioni dei lobi olfattorii negli 
arthropodi superiori e nei vertebrati. Atti Accad. Lincei Ann. 279 Mem. 
Accad. Bologna, Vol. XIII, pp. 555-564: and in Arch. Ital. Biol. 1883; 
Vol. III, pp. 191-196. 

Bellonci, G., Sulla terminazione centrale del nervo ottico nei mammiferi. Mem. 
Accad. Bologna, Vol. VI, pp. 199-205: and in Arch. Ital. Biol. 1884, Vol. VI, 
pp. 495-411. 

Bidder, F. H., Die Endigungsweise der Herzzweige des N. vagus beim Frosch. 
Arch. f. Anat. u. Physiol. 1839, p. I. 

Bidder, F. H., Zur Lehre von dem Verhältniss der Ganglienkérper zu den Nerven- 
fasern. Nebst einem Anhange von Dr. A. W. Volkmann. Leipzig, 1847. 

Bidder, F. H., Zur Lehre vom Verhalten der Ganglienkürper, u. s. w. Leipzig, 
1847. 

Bidder, F. H., Ueber functionelle verschiedene und räumlich getrennte Nerven- 
centra im Froschherzen. Arch. f. Anat. u. Physiol. 1852, p. 163. 

Bidder, F. H., Endigungsweise der Herzzweige des N. vagus beim Frosch. Arch. 
f. Anat. und Physiol. 1868, p. 1. 

Bidder, F. H., Zur näheren Kenntniss des Froschherzens und seiner Nerven. 
Arch. f. Anat. u. Physiol. 1866, p. 1. 

Bidder, F. H., and Kupffer, Untersuchungen tiber die Textur des Riickenmarks. 
Leipzig, 1857. 

Bidder, F. H., and Volkmann, A. W., Die Selbstiindigkeit des sympathischen 
Nervensystems, durch anatomische Untersuchungen nachgewiesen. Leipzig, 
1842. 

Bidder and Gregory, Beitriige zur Physiologie der Herzbewegung beim Frosche. 
Dorpat, 1865. 

Bikfalvi, K., Ueber die Hornscheide der markhaltigen Nervenfasern. Orvoster- 
mészettudomanyi Ertesito, 1884, p. 133. Abstract in Centralbl. f. d. med. 
Wiss. 1886, p. 34. 

Biroege, E. A., Die Zahl der Nervenfasern u. der motor. Ganglienzellen im Riicken- 
mark des Frosches. Arch. f. Anat. u. Physiol. 1882. Physiol. Abth., p. 435. 

Bischoff, Nervi accessorii Willisii anatomia et physiologia. Heidelberg, 1832. 

Blasius, G., Gerardi Blasii Anatomia Animalium. Amstelodami, 1681. 

Blattmann, A., Mikrosk. anatom. Darstellung der Centralorgane des N ervensystems 
bei den Batrachiern. Dissert. Zürich, 1850. 

Boll, F., Studj sulle immagini microscopiche della fibra nervosa midollare. Atti 
della R. accademia dei Lincei, 1876-1877. Vol. II. 

* Boll, F., Ueber Zersetzungsbilder der markhaltigen Nervenfasern. Arch. f. Anat. u. 
Physiol. 1877, p. 288. 

Bojanus, Testudinis anatomia. 1810. | 

Bosse, De ganglior. spinal. vi in nutr. radic. poster. nervor. spinal. Dissert. 1859. 

Boveri, T., Beiträge zur Kenntniss der Nervenfasern. Abhandl. d. bayr. Akad. d. _ 
Wiss. 1885. Vol. XV, p. 421. 

Bremer, D. L., Die Nerven der Capillaren, der kleinen Arterien und Venen. 
Arch. f. mik. Anat. Vol. XXI. 1882, p. 663. 

Bremer, L., Ueber die Muskelspindeln sowie über Structur, Neubildung u. Inner- 
vation der quergestreiften Muskelfaser. Waldeyer’s Arch. 1883. Vol. XXII, 


pee 


124 THE NERVOUS SYSTEM. 


Bremer, L., Ueber die Endigungen der markhaltigen und marklosen Nerven im 
quergestreiften Muskel. Arch. f. mikrosk. Anat. 1882. Vol. XXI, p. 165. 
Brenner, A., Ueber das Verhältniss des nervus laryngeus inferior vagi zu einigen 
Aortenvarietiiten des Menschen und zu dem Aortensystem der durch Lungen 
athmenden Wirbelthiere überhaupt. His u. Braune’s Arch. 1883, pp. 373-397- 

Budge, J., Ueber den Verlauf der Nervenfasern im Riickenmark des Frosches. 
Arch. f. Anat. u. Physiol. 1844, p. 160. 

Budge, J., Ueber die Bewegung der Iris. (Concerning ganglia of motor-oculi, p. 36.) 

Budge, J., Wagner’s Handwürterb. d. Physiologie. 1846. Vol. ITI, p. 451. 

Burdon-Sanderson, J., Circulation of the Blood. Handbook for the Physiological 
Laboratory. London, 1873. 

Calberla, E., Ueber die Endigungsweise der Nerven in den quergestreiften Muskeln 
bei Amphibien. Zeit. f. wiss. Zool. 1874. Vol. XXIV, p. 164. 

Calberla, E., Studien über die Entwicklung der quergestreiften Muskeln und Nerven 
der Amphibien und Reptilien. Arch. f. mik. Anat. 1875. Vol. XI, p. 442. 

Carus, Versuch einer Darstellung des Nervensystems und Gehirns. Leipzig, 1814. 

Champness, F., The septum atrium of the Frog and Rabbit. Journ. of Anat. and 
Physiol. 1874. 

Christmas-Dirckinck-Holmfeld, J., Experimentaluntersuchungen über den Bau 
der Regio olfactoria. Nord. med. ark. 1883. Vol. XV, No. 3. 

Ciaccio, G. V., On the nerves of the Cornea, and their distribution in the corneal 
tissue of man and animals. Proc. Roy. Soc. 1863. Abstract in Trans. Micros. 
Soc. London, 1863. Vol. XI, pp. 77-93. 

Ciaccio, G. V., On the distribution of nerves to the skin of the frog, with physio- 
logical remarks on the ganglia connected with the cerebro-spinal nerves. Quart. 
Journ. Micros. Sci. 1864. Vol. IV, pp. 15-31. 

Ciaccio, G. V., Intorno alla minuta fabbrica delle pelle Rana esculenta. Giornale 
di Scienze naturali ed economiche. Palermo, 1866. Vol. II, p. 103. 

Clarke, J. Lockhart, Ueber den Bau des Bulbus olfactorius und der Geruchsschleim- 
haut. Zeit. f. wiss. Zool. 1862. Vol. XI, p. 31. 

Cornil and Ranvier, A Manual of Pathological Histology. London, 1880, p. 359, 
Fig. 199 (Ganglia of heart). 

Courvoisier, G., Beobacht. über den sympathischen Gränzstrang. Arch. f. mik. 
Anat. 1866. Vol. II, p. 13. 

Courvoisier, L. G., Ueber die spinalen und sympathischen Zellen des Frosches. 
Centralbl. f. d. med. Wiss. 1867, p. 897. 

Courvoisier, G., Ueber die Zellen der Spinalganglien, sowie des Sympathicus beim 
Frosch. Arch. f. mikrosk. Anat. 1868. Vol. IV, p. 125. 

Cuvier, Leçons d’anatomie comparée. 2nd Edit. Vol. II. 

Cyon, Ueber die Nerven des Peritoneum. Berichte über die Verhandlungen d. 
künigl. sächs. Gesellsch. d. Wissensch. zu Leipzig. Math.-physik. Classe. 1868. 
Vol. XX, p. 119. 

Czermak, J. N., Ueber die Hautnerven des Frosches. Arch. f. Anat. u. Physiol. 
1849, p. 252. Leipzig, 1869. 

Czermak, J. N., Ueber die Herznerven des Frosches, Rana temporaria. Arch. f. 
Anat. u. Physiol. 1851, p. 160. 

v. Darkschewitsch, L., Zur Anatomie der Glandula pinealis. Neurol. Cent. Bl. 
1886. Vol. V, p. 20. 

v. Deen, De differentia et nexu inter nervos vitae animalis et vitae organicae. 
Diss. inaugur. Lugduni-Bat., 1834. 

v. Deen, Over de zijdelingsche Takken dar swervende zenuw van den Proteus 
anguineus, aus Bijdragen tot de Naturkundige. Wettenschappen, 1834. 

v. Deen, Ueber den Ramus lateralis n. vagi bei den Batrachiern. Arch. f. Anat. u. 
Physiol. 1834, p. 477 (abstract from Diss. inaugur. De differentia et nexu inter . 
nervos vitae animalis et vitae organicae). Lugduni-Bat. 


LITERATURE. 125 


Deiters, O., Untersuchungen über Gehirn und Riickenmark. Braunschweig, 1865. 

Denissenko, G., Zur Frage über den Bau der Kleinhirnrinde bei verschiedenen 
Klassen von Wirbelthieren. Arch. f. mikrosk. Anat. 1877. Vol. XIV, 
p. 203. 

Dietl, M. J., Beobachtungen über Theilungsvorgiinge an Nervenzellen. Wiener 
Sitzungsber. 1874. Vol. LXIX, Pt. ITI, p. 71. 

Dietl, M. J., Casuistische Beïträge zur Morphologie der Nervenzellen. Wiener 
Sitzungsber. 1874. Vol. LXIX, Pt. III, p. 80. 

Dogiel, J., Die Ganglienzellen und Nerven des Herzventrikels beim Frosche. Arch. 
f. mikrosk. Anat. 1877. Vol. XIV, p. 470. 

Dogiel, J., Die Ganglienzellen des Herzens bei verschiedenen Thieren und beim 
Menschen. Arch. f. mikrosk. Anat. 1877. Vol. XVII, p. 471. 

Dogiel, J., Die Nervenzellen und Nerven des Herzventrikels beim Frosche. Arch. 
f. mikrosk. Anat. 1882. Vol. XXI, p. 21. 

Duméril, A. M. C., and Bibron, G., Erpétologie générale ou histoire naturelle com- 
plète des reptiles. Paris, 1841. 

Eberth, Untersuchungen zur normalen und pathologischen Anatomie der Froschhaut. 
Leipzig, 1869. 

Ecker, A., Icones physiologicae. Leipzig, 1851 to 1850. 

Eckhard, C., Beiträge zur Anatomie und Physiologie. Giessen, 1860. Vol. II. 

Eckhard, C., Experimentale Physiologie des Nervensystems. Giessen, 1867, p. 208 
(Ganglion cells of heart). 

Edinger, L., Nachtrag zu dem Bericht über Leistungen auf dem Gebiete der Ana- 
tomie des Centralnervensystems. Schmidt's Jahresb. 1887. 

Egorow, W., Ueber die Nervenzellen der Lungen. Centralbl. f. med. Wiss. 1879. 
Vol. XVII, p. 305. 

Bichholtz, De piscium atque amphibiorum nudorum lobis opticis atque olfactoriis. 
Berolini, 1841. 

Engelmann, T. W., Zur Physiologie des Ureter. Pfliiger’s Arch. f. d. ges. 
Physiol. 1869. Vol. II, p. 243. (Treats also of histological details of frog’s 
bladder.) 

Engelmann, T. W., Ueber die Discontinuität des Axencylinders und den fibrillären 
Bau der Nervenfasern, Pfliiger’s Arch. f. d. ges. Physiol. 1880. Vol. XXII, 
1h te 

- + Engelmann, T. W., Der Bulbus aortae des Froschherzens. Pfliiger’s Arch. f. d. 

ges. Physiol. 1882. Vol. XXIX, p. 425. 

Fischer, E., Ueber die Endigung der Nerven im quergestreiften Muskel der Wir- 
belthiere. Arch. f. mik. Anat. 1876. Vol. XIII, pp. 365-390. 

Fischer, J. G., Amphibiorum nudorum neurologiae specimen primum. Berlin, 
1843; and Arch. f. Anat. u. Physiol. 1844, p. 57. 

Fowelin, C., De causa mortis post nervos vagos dissectos instantis. Inaug. Dissert. 
Dorpati, 1851. 

~ Frenkel, $S., Nerv und Epithel am Froschlarvenschwanze. Arch. f. Anat. u. 
Physiol. 1886. Physiol. Abth., p. 405. 

Frey, Handb. d. Histologie u. Histochemie d. Menschen. 3rd Edit., p. 341. (Ganglia 

of heart.) 
— Friedlander, Ueber die nervüsen Centralorgane des Froschherzens. Untersuch. 
aus d. physiol. Laborat. zu Würzburg. 1867. 
~ Frommann, Ueber Structur der Nervenzellen. Virchow’s Arch. 1864, Vol. XXXI, 
p. 129. 

Fubini, S.,Gewicht des centralen Nervensystems im Vergleich zu dem Kürpergewicht 
der Thiere, bei R. esculenta u. R. temporaria, Moleschott’s Untersuchungen zur 
Naturlehre d. Menschen. 1881. Vol. XII, pp. 455-461. 

Gad, J., Ueber Centrum und Leitungsbahnen im Riickenmark des Frosches. Ver- 
hand]. der Physiol. Gesellsch. zu Berlin, No. 10,1884. Arch. f. Anat. u. Physiol. 


0 


126 THE NERVOUS SYSTEM. 


1884, p. 304 Verhandl. d. physick. med. Gesellsch. zu Wiirzburg. 1884. 
Vol. XVIII. 

~ Gaskell, W. H., On the augmentor (accelerator) nerves of the heart of cold-blooded 
animals. Journ. of Physiol. 1884. Vol. V, p. 46. 

~ Gaskell, W. H., and Gadow, On the anatomy of the cardiac nerves in certain cold- 
blooded animals. Journ. of Physiol. 1884. Vol. V, p. 362. 

Gaskell, W. H., The Structure, Distribution, and Function of the Nerves which 

innervate the Visceral and Vascular System. Journ. of Physiol. 1886. Vol. 


VII, p. 1. 
Gegenbaur, C., Grundzüge der vergleichenden Anatomie. 1870. 2nd Edition, 
p. 728. 


Gerlach, J., Ueber das Verhalten der Nerven in den quergestreiften Muskelfäden 
der Wirbelthiere. Sitzungsber. d. phys.-med. Societät zu Erlangen. 1873. 
Vol. V, p. 97. 

Gerlach, J., Das Verhältniss der Nerven zu den willkürlichen Muskeln der Wir- 
belthiere. Leipzig, 1874. 

— Gerlach, J., Ueber die Nervenendigungen in der Muskulatur des Froschherzens. 
Virchow’s Arch. 1876. Vol. LXVI, pp. 187-223. 

Gerlach, J., Das Verhältniss der nervésen und contractilen Substanz d. querge- 
streiften Muskels. Arch. f. mikrosk. Anat. 1877. Vol. XIII, p. 399. 

Giuliani, Sulla struttura del midollo spinale della Lacerta viridis. Memorie della 
R. academia dei Lincei. Roma, 1878. 

Goette, A., Kurze Mittheilungen aus der Entwicklungsgeschichte der Unke. Arch. 
f. mik. Anat. 1873. Vol. IX, p. 396. 

Goette, A., Entwickelungsgeschichte der Unke. Leipzig, 1875. 

Golgi, C., Sulla fina anatomia degli organi centrali del sistema nervoso. Milano, 
1866. 

Golgi, C., Sui Nervi dei Tendini dell’ Uomo e di altri Vertebrati e di un nuovo 
organo nervoso terminale muscolo-tendineo. Estr. dalle Memoire della Reale 
Acc. di Torino. 1880. Vol. XXXII, p. 29. 

Gonjaew, K., Die Nerven des Nahrungsschlauches. Arch. f. mikrosk. Anat. 1875. 
Vol. XI, pp. 479-496. 

de Graaf, H. W., Zur Anatomie u. Entwicklung d. Epiphyse bei Amphibien u. 
Reptilien. Zool. Anz. 1886. Vol. IX, No. 219. 

de Graaf, H. W., Over den bouw der epiphyse bij de amphibien. Tijdschr. der 
Nederl. dierkundige Vereeniging. 1886. Vol. II, p. I. 

de Graaf, H. W., Bijdrage tot de kennis van der bouw ende entwickkeling der 
epiphyse bij amphibién en reptilién. Inaug.-Diss. Leiden, 1886. Abstract in 
Centralbl. f. d. med. Wiss, 1886, p. 706. 

Grant, R., Comparative Anatomy. London, 1839. 

Grant, R., Umrisse der vergleichenden Anatomie von R. E. Grant. Aus dem En- 
glischen von C.C. Schmidt, M.D. Leipzig, 1842. 

* Gruenhagen, A., Ueber ein Endothelialelement der Nervenprimitivscheide. Arch. 
f. mik. Anat. 1884. Vol. XXIII, p. 380. 

Gscheidlen, R., Ueber Nervenendigung in den glatten Muskelfasern. Arch. f. 
mik. Anat. 1877. Vol. XIV, pp. 320-332. 

Guillot, Exposition anatomique de l’organisation des centres nerveux dans les quatres 
classes d'animaux vertébrés. Paris, 1844. 

Hannover, A., Die Chromsiiure, ein vorzügliches Mittel bei mikroskopischen Unter- 
suchungen. Arch. f. Anat. u. Physiol. 1840, pp. 549-556. (Describes the con- 
nection between fine fibres and small ganglia in the central nervous system of 
fish, frogs, and birds. ) 

Hannover, A., Recherches microscopiques sur le système nerveux. Recherches 
sur le cerveau de la grenouille, pp. 20-22. Kopenhagen, Paris, and Leipzig, 
1844. 


LITERATURE. LZ. 


Harless, Ern., Ueber die Functionen verschiedener Parthien des Riickenmarks der 
Amphibien. Arch. f. Anat. u. Physiol. 1846, p. 74. 

Hartmann, D. R., Ueber die Endigungsweise der Nerven in den Papillae fungi- 
formes der Froschzunge. Arch. f. Anat. u. Physiol. 1863, p. 634. 

Heidenhain, Disquisitiones de nervis organisque centralibus cordis. Dissert. inaug. 
Berol. 1854; and in Arch. f. Anat. u. Physiol. 1858, p. 479. 

Hénoque, Du mode de distribution et de la terminaison des nerfs dans les muscles 
lisses. Arch. de l’Anat. et de la Physiol. 1870. 

~ Hensen, V., Ueber die Entwicklung des Gewebes und der Nerven im Schwanze der 
Froschlarve. Virchow’s Arch. 1864. Vol. XXXI, p. 51. 

Hensen, V., Ueber die Nerven im Schwanz der Froschlarven. Arch. f. mik. Anat. 
1868. Vol. IV, p. 111. 

Hesse, F., Zur Kenntniss der peripherischen markhaltigen Nervenfaser. His u. 
Braune’s Arch. f. Anat. u. Physiol. 1879. Vol. VI, p.89. Abstract in Centralbl. 
f. d. med. Wiss. 1880, p. 324. 

His, W., Ueber die Endigung der Gefässnerven. Virchow’s Arch. 1863. Vol. 
XX VIII, p. 427. 

Hjelt, De nervis cerebralibus parteque cephalica nervi sympathici Bufonis cinerei 
adnotata quaedam. Helsingforsiae, 1852. 

Hoffmann, C. K., in Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig and 
Heidelberg, 1873-1878. Vol. VI. Amphibia. 

Holl, M., Ueber den Bau der Spinalganglien. Wiener Sitzungsber. 1876. Vol. 
LXXII, Pt. ITI, p. 31. 

Horn, H., Ueber die Endschlingen des Geruchsnerven (Nervus olfactorius) in Rana 
temporaria. Arch. f. Anat. und Physiol. 1850. 

~ Huizinga, D., Untersuchungen über die Innervation der Gefässe in der Schwimm- 
haut des Frosches. Pfliiger’s Arch. f. d. ges. Physiol. 1875. Vol. XI, pp. 
207-221. 

Huxley, T. H., Article Amphibia. Encyclopaedia Britannica, oth Edition. 

Isquierdo, V., Ueber die Endigungsweise der sensiblen Nerven. Arch. f. mikrosk. 
Anat. 1880. Vol. XVII, p. 367. 

Jacubowitsch, M. N., Terminaisons des nerfs à la périphérie et dans les différents 
organes ou terminaisons périphériques du systeme nerveux en général. Comptes 
rendus. 1860. Vol. L, p. 859. 

Jantschitz, J., Materialien zur Anatomie der Nerven des Pericardiums. Rudneff’s 
Journ. f. normale u. patholog. Histologie u. klinische Med. St. Petersburg, 
1874, pp. 417-442. (In Russian, Abstract in Centralbl. f. d. med. Wiss. 
1874.) 

Johnson, A., and Sheldon, L., Note on the Development of the Newt (Triton 
cristatus). Quart. Journ. Micros. Sci. 1886. Vol. X XVI, p. 573. 

Kandarazki, M., Ueber die Nerven der Respirationswege. His u. Braune’s Arch. 
f. Anat. u. Entwickelungsgesch. 1881, pp. I-11. 

Kanhel, G., Studien über Innervation der Lymphherzen. Medic. Jahrb. 1886, 
pp. 392-420. 

Karabanowitsch, D., Ueber den Bau des Rückenmarkes vom Frosche. Arbeiten 
der St. Petersburger Gesellsch. der Naturforscher. St. Petersburg, 1872, pp. 
402-421. 

Key, A., and Retzius, G., Studien in der Anatomie des Nervensystems. Arch. f. 
mikrosk. Anat. 1873. Vol. IX, p. 308. 

Klebs, E., Die Nerven der organischen Muskeln. Centralbl. f. wiss. Med. 1863, 
p. 561. 

~ Klebs, E., Die Nerven der organischen Muskelfasern. Virchow’s Arch. 1865. Vol. 
XXXII, p. 168. 

Klein, E., Beitrige zur Anatomie der ungeschwänzten Batrachier. Wiirttemberger 
Jahreshefte. 1850, pp. 1-84. 


128 THE NERVOUS SYSTEM. 


Klein, E., Auerbach’s Plexus in the Intestine of Frog and Toad. Quart. Journ. 

Microsc. Sci. 1873. Vol. XIII, pp. 377-380. 
~ Klein, E., Some remarks on the finer nerves of the Cornea. Monthly Micros. Journ. 
1872. Vol. VII, pp. 156-164. 

Klein, E., On the peripheral distribution of non-medullated nerve-fibres. Quart. 
Journ. Microse. Sci. 1871. Vol. XI, New Series, p. 405. 

Klug, F., Ueber die Herznerven des Frosches. Arch. f. Anat. u. Entwicklungs- 
gesch. 1881, pp. 330-346. 

Klug, F., Ueber die Beschleunigungsnerven des Froschherzens. Centralbl. f. med. 
Wissensch. Berlin, 1881, pp. 945-948. 

v. K6lliker, A., Neurologische Bemerkungen. Zeit. f. wiss. Zool. 1849. Vol. I, 
p- 135- 

v. K6élliker, A., Handbuch der Gewebelehre. 5th Edit. 1861, p. 163. (On nerve- 
fibres of frog’s heart.) 

v. Külliker, A., Vorläufige Mittheil. über den Bau des Riickenmarks bei niederen 
Wirbelthieren. Zeit. f. wiss. Zool. 1858. Vol. IX, p. 1. 

v. Kôlliker, A., Ueber die letzten Endigungen der Nerven in Muskeln des Frosches. 
Wiirzburger naturwissensch. Zeitschrift, Vol. III. Sitzungen, 8th and 22nd 
March, 1862. 

v. Kôülliker, A., Untersuchungen über die letzten Endigungen der Nerven. Zeit. f. 
wiss. Zool. 1863. Vol. XII, p. 149. 

v. Kôlliker, A., Histologische Studien an Batrachierlarven. Zeit. f. wiss. Zool. 
1886. Vol. XII, pp. 1-4. 

— v. Kôlliker, A., Ueber die Vitalität der Nervenrohren der Frésche. Würzburg. 
Verhandl. 1857. Vol. VII, p. 145. 

Kollmann, J., Ueber den Verlauf des Lungenmagennerven in der Bauchhohle. 

Zeit. f. wiss. Zool. 1859-1860. Vol. X, p. 413. 
~Kollmann, J., and Arnstein, Die sympathischen Ganglienzellen des Frosches. 
Zeitschr. f. Biologie. 1866. Vol. II, p. 271. , 

Kônigstein, L., Beobachtungen über die Nerven der Cornea und ihre Gefässe. 
Wiener Sitzungsber. 1878. Vol. LXXVI, Pt. ITI, p. 37. 

Kôppen, M., Zur Anatomie des Froschgehirns. Neurologisches Centralblatt. 1888. 

Kôppen, M., Zur Anatomie des Froschgehirns. Arch. f. Anat. u. Physiologie, 
1888. 

Korybutt-Daszkiewicz, W., Ueber die Entwicklung der Nerven aus Plasmazellen 
beim Frosche. Arch. f. mikrosk. Anat. 1878. Vol. XV, p. I. 

Krause; W., Die Nervenendigungen in den Froschmuskeln, Internat. Monats. f. . 
Anat. u. Histologie. 1884. Vol. I, p. 194. 

“Krause, W., Ueber die Driisennerven. Zeitschr. f. rat. Medicin. Dritte Reihe. 
Vol. XXIII, p. 60. 

Krohn, A., Ueber den Ramus lateralis n. vagi bei niedrigen Amphibien. Fror. 
Not. 1836. Vol. XLVIII, p. 1043. 

Krohn, A., Ergänzungen der Nachricht über den n. lateralis der Froschlarven. 
Fror. Not. 1838. Vol. VII, n. 137. 

Kühne, W., Die Endigungsweise der Nerven in den Muskeln und das doppelsinnige 
Leitungsvermégen der motorischen Nervenfaser. Monatsbericht der Künigl. 
Akademie der Wissenschaften zu Berlin, 19 May, 1859. 

~ Kühne, W., Die peripher. Endorgane der motorischen Nerven. Leipzig, 1862. 

Kühne, W., Zur Lehre von den Endplatten der Nervenhiigel. Virchow’s Arch. 
1865. Vol. XXXIV, p. 412. 

Kühne, W., Zur Histologie der motorischen Nerven. W. Kiihne’s Heidelberger 
Untersuchungen, 1879. Vol. II, p.187. Abstract in Centralbl. f. d. med. Wiss. 
1879, p. 405. 

Kühne, W., Ueber Nervenendigungen in den Muskeln nach Beobachtungen von M. B. 
von Syckel. Verhandl. des naturf. Vereins z. Heidelberg, 1884. Vol. ITI, p. 238. 


LITERATURE. 129 


Kühne, W., Widerlegen der Bemerkung E. du Bois-Reymonds über mehrfache 
Nervenendigungen in einer Muskelfaser. Zeitschr. f. Biol. 1884. Vol. XX, 
PP- 531-539. 

Kühne, W., Ueber das doppelsinnige Leitungsvermégen der Nerven. Zeitschr. f. 
Biol. 1886. Vol. XXII, p. 305. 

Kuhnt, J. H., Die peripherischen markhaltigen Nervenfasern. Arch. f. mik. Anat. 
1877. Vol. XIII, p. 427. 

Kupffer, De medullae spinalis textura in Ranis. 1854. Dissert. inaug. 

Kutschin, Zur Structur des Nervengewebes. Centralbl. f. d. med. Wiss. 1865, 
p. 561. 

Küttner, C., De origine n. sympathici ranarum, ex nervorum dissectorum muta- 
tionibus dijudicatur. Dorpat, 1854. Dissert. inaug. 

Lahousse, P., Die Structur des Nervenplexus in der Vorhofscheidewand des Frosch- 
herzens. Arch. f. Anat. u. Physiol. 1886, p. 19. 

Langerhans, P., Zur Histologie des Herzens. Virchow’s Arch. 1873. Vol. LVIII, 


p- 65. 


~ Lantermann, A. J., Bemerkungen über den feineren Bau der markhaltigen Nerven- 


fasern. Centralbl. f. d. med. Wiss. 1874, p. 706. 
Lantermann, A. J., Ueber den feineren Bau der markhaltigen Nervenfasern. 
Arch. f. mikrosk. Anat. 1877. Vol. XIII, p. 1. 


. Lavdowsky, N., Die feinere Structur und die Nervenendigungen der Froschharn- 


blase. Arch. f. Anat. und Physiol. 1872, p. 55. 


~Lavdowsky, N., Das Saugadersystem und die Nerven der Cornea. Arch. f. mikrosk. 


\ 


1 


Anat. 1872. Vol. VIII, p. 538. 
Lavdowsky, N., Zum Nachweis der Axencylinderstructurbestandtheile von mark- 
haltigen Nervenfasern. Centralbl. f. d. med. Wiss. 1879, pp. 865, 881. 


‘Lavdowsky, N., Ueber die Fortsätze der Nervenzellen in den Herzganglien. Arch. 


f. mik. Anat. 1887. Vol. X XIX, p. 609. 

Lehmann, J. C., Ueber die Nervenendigungen und das Vorkommen von mikro- 
skopischen Ganglien in den Gefässwandungen. Zeit. f. wiss. Zool. 1864. Vol. 
XIV, pp. 346-352. 

Lenhossek, M., Untersuchungen tiber die Spinalganglien des Frosches. Arch. f. 
mikrosk. Anat. 1886. Vol. XX VI, pp. 370-453. 

Leuret, Anatomie comparée du système nerveux de l’homme et des animaux 
vertébrés. Paris. Vols. I, IT. 

Lipmann, Die Nerven der organischen Muskeln. Dissert. Berlin, 1869. 

Lominsky, T., Zur Frage über die Teilung der Nervenzellen. Centralbl. f. d. med. 
Wiss. 1882, p. 434. 

Longet, Anatomie et Physiologie du système nerveux de l’homme et des animaux 
vertébrés. Paris, 1842. 

Lôwit, M., Die Nerven der glatten Muskulatur. Wiener Sitzungsb. 1875. Vol. 
LXXI, Pt. III, p. 355. 

Lôwit, M., Beiträge zur Kenntniss der Innervation des Froschherzens. Pfliiger’s 
Arch. f. d. ges. Physiol. Vol. XXIII, p. 313; Vol. XXV, p. 399; Vol. XXVIII, 
p- 312; Vol. XXIX, p. 460. 


» Lôwit, M., Ueber die Gegenwart von Ganglienzellen im Bulbus aortae des Frosch- 


herzens. Pfliiger’s Arch. f. d. ges. Physiol. 1883. Vol. XXXI, pp. 88-94. 


* Léwit, M., Beitrage zur Kenntniss der Innervation des Herzens. Pfliiger’s Arch. f. 


d. ges. Physiol. 1881. Vol. XXV, pp. 399-496, 


> Luchsinger, B., Zur Innervation d. Lymphherzen. Pfliiger’s Arch. f. d. ges. Physiol. 


1880. Vol. XXIII, p. 304. 

Ludwig, C., Ueber die Herznerven des Frosches. Arch. f. Anat. u. Physiol. 1848, 
p. 139- 

Macallum, A. B., The Nerve Terminations in the Cutaneous Epithelium of the 
Tadpole. Quart. Journ. Micros. Sci. 1885. Vol. XXVI, p. 53. 


K 


130 THE NERVOUS SYSTEM. 


Maddox, On the apparent relation of Nerve to Connective-tissue Corpuseles. 
Monthly Microse. Journ. Vol. IX, p. 109. 

Maier, R., Die Ganglien in den harnabführenden Wegen des Menschen und einiger 
Thiere. Arch. f. pathol. Anat. u. Physiol. 1881. Vol. LXXXYV, p. 49. 


~ Marchi, P., Beobachtungen über Wimper-Epithel. Arch. f. mik. Anat. 1866. Vol. 


II, p. 467. 

Marshall, A. M., The segmental value of the Cranial Nerves. Journ. of Anat. and 
Physiol. Vol. XVI, pp. 305-354. 

Marshall, A. M., The Frog: an introduction to Anatomy and Physiology. Man- 
chester and London, 1885. 

Masius and Vaulair, De la situation et de l’étendue des centres réflexes de la 
moelle épinière chez la grenouille. Bruxelles, 1870. 

Mason, J.J., A new group of Nerve-cells in the Spinal Cord of the Frog. New York 
Med. Journ. 1570. 

Mason, J. J., Microscopic Studies on the Central Nervous System of Reptiles and 
Batrachia. Journ. of Nerv. and Mental Diseases. New York. 1880, Vol. 
VII, p. 8; 1881, Vol. VIII, p. 7. 

Mason, J. J., Minute Structure of the Central Nervous System of certain Reptiles 
and Amphibia of America. Newport, 1884. 

Mayer, A. F. J. C., Ueber das Gehirn der Amphibien und ein zoologisches Gesetz. 
Fror. Notizen, 1833. Vol. XXX VII, pp. 49-53. 


~Mayer, S., Zur Lehre der Struktur der Spinalyanglien und der peripherischen 


4 


Nerven in Rana esculenta. Arch. f. Anat. u. Physiol. 1858, p. 274. 

Mays, K., Histo-physiol. Untersuchungen tiber die Verbreitung der Nerven in den 
Muskeln. Zeitschr. f. Biol. Vol. XX, p. 449. 

Mays, K., Ueber die Nervatur des Musculus rectus abdominis des Frosches. Hei- 
delberg, 1886. 

Mays, K., Nervenfasertheilungen in den Nervenstimmen der Froschmuskeln. 
Zeitschr. f. Biologie. 1886. Vol. XXII, p. 354. : 

Meckel, A., System der vergleichenden Anatomie. Halle, 1833. 

Meckel, J. F., Beitriige zur vergleichenden Anatomie. Leipzig, 1811. 

Michel, Ueber den Bau des chiasma nervorum opticum. vy. Griife’s Arch. 1864. 
Vol. XIX, p. 59. 

Miller, J., Beitrige zur Anatomie und Naturgeschichte der Amphibien. Tiede- 
mann’s Zeitschr. 1831. Vol. IV, pp. 190-275. 

Namias, M., Sui ganglii miocardici della Rana. Osservazioni ed esperienze in Lo 
Spallanzani. 1881. Vol. X, pp. 402-410. 

Niccolucci, G., Sul sistema nervoso e circolatorio della Salamandra aquaivola. 
Napoli, 1842. 

Niura, M., Untersuchungen über die motorischen Nervenendigungen der querge- 
streiften Muskelfasern. Virchow’s Arch. 1886. Vol. CV, p. 129. 


> Obersteiner, Ueber einige Lymphräume im Gehirne. Wiener Sitzungsber. 1870. 


Vol. LXI, Pt. I, p. 57. 

Odenias, M. W., Undersékungar üfver de sensibla muskelnervena. Nord. Medic. 
Arch. Vol. IV, No. 18. 

Onodi, A. D., Ueber die Entwicklung des sympathischen Nervensystems. Arch. f. 
mik. Anat. 1886. Vol. XX VI, p. 61. 

Onodi, A. D., Ueber die Gangliengruppen der hinteren u. vorderen Nervenwurzeln. 
Centralbl. f. wiss. Med. 1885. Nos. 16 and 17. 

v. Openchowski, Th., Beitrag zur Kenntniss d. Nervenendigungen im Herzen. 
Arch. f. mik. Anat. 1883. Vol. XXII, pp. 408-410. 

v. Openchowski, Th., Histologisches zur Innervation der Drüsen. Pflüger’s Arch. 
f. d. Ges. Physiol. 1882. Vol. XX VII, p. 223. 

Osborne, H. F., Observations upon the Urodele Amphibian Brain. Zool. Anz, 
1884. Vol. VII, p. 679. 


LITERATURE. Tor 


Osborne, H. F., Observations on the presence of the corpus callosum in the brains 
of Amphibians and Reptiles. Zool. Anz. 1886. Vol. IX, p. 200. 

Osborne, H. F., Note upon the cerebral commissures in the lower vertebrata and a 
probable fornix rudiment in the brain of Tropidonotus. Zool. Anz. 1886. Vol. 
IX, p. 577. 

Partsch, C., Beitriige zur Kenntniss des Vorderdarmes einiger Amphibien und 
Reptilien. Arch. f. mik. Anat. 1877. Vol. XIV, p. 179. 

~ Pertik, O., Untersuchungen über Nervenfasern. Arch. f. mik. Anat, 1881. Vol. 
XIX, p. 183. 

~ Pfitzner, Nervenendigungen im Epithel. Morph. Jahrb. 1882. Vol. VII, pp. 
726-745. 

Popoff, N., Die Nerven der Gallenblase. Rudneff’s Journ. f. normale und pathol. 
Histologie u. klin. Med. St. Petersburg, 1872. (In Russian. Abstract in 
Virchow and Hirschfeld’s Arch.) 

Priestley, J., An account of the anatomy and physiology of the batrachian lymph- 
hearts. Journ. of Physiol. 1878. Vol. I, p. 1. 

"+ Ranvier, L., Recherches sur Vhistologie et la physiologie des nerfs. Arch. de 
physiol. normale et pathologique. 1872. Vol. IV, pp. 427-446. 

Ranvier, L., Appareil nerveux terminaux des muscles de la vie organique. Leçons 
d’anat. générale. Paris, 1880, p. 350. 

Ranvier, L., Des tubes nerveux en T et de leurs relations avec les cellules gang- 
lionaires. Compt. rend. 1875. Vol. LXXXI, p. 1274. 

Ranvier, L., Leçons sur l’histologie du système nerveux. 1878. Vol. I, pp. 98-101. 

-Rawitz, B., Ueber die Structur der Zellen in den Spinalganglien, etc. Arch. f. 
mik. Anat. 1880. Vol. XVIII, p. 283. 

Rawitz, B., Ueber den Bau der Spinalganglien. Arch. f. mik. Anat. 1880. Vol. 
XVIII, p. 283. 

Rawitz, B., Ueber den Bau der Spinalganglien. Arch. f. mik. Anat. 1882. Vol. 
XXI, p. 244. 

Reichert, K. E., Ueber das Verhalten der Nervfasern bei dem Verlauf der Ver- 
theilung und Endigung in einem Hautmuskel des Frosches, Rana temporaria. 
Arch. f. Anat. u. Physiol. 1851, p. 29. 

Reissner, E., Der Bau des centralen Nervensystems der ungeschwänzten Batra- 
chier. Dorpat, 1864. 

+ Remak, R., Anatomische Beobachtungen über das Gehirn, das Riickenmark und die 
Nervenwurzel. Arch. f. Anat. u. Physiol. 1841, pp. 506-522. 

- Remak, R., Multipolare Ganglienzellen. Berliner Monatsberichte. 1854, p. 26. 

Retzius, G., Undersékung üson cerebrospinalganglionus nervseller and särskild 
häusyn till dessus ut lüpare. Nord. Med. Arkiv. 1870. 

Retzius, G., Untersuchungen über die Nervenzellen der cerebrospinalen Ganglien, 
etc. Arch. f. Anat. u. Physiol. 1880, p. 360. 

— Reynier, Les nerfs du cœur. Paris, 1880 (pp. 32-37, ganglia of heart). 

Rosenberger, De centris motuum cordis disquisitiones anatomico-pathologicae. 
Inaug. Diss. Dorpat, 1850. 

— Rouget, Note sur la terminaison des nerfs moteurs dans les muscles chez les 
reptiles, les oiseaux et les mammifères. Compt. rend. 1862. Vol. LV, pp. 
548-555. 

~ Rumph, T., Zur Histologie der Nervenfaser und des Axencylinders. W. Kühne’s 
Heidelberger Untersuchungen. 1879. Vol. II, p. 355. À 

— Sachs, C., Die Nerven der Sehnen. Reichert u. du Bois-Reymond’s Arch. 1875, 
p. 402. 

~ Sander, J., Die Spinalfasern im Sympathicus des Frosches. Arch.f. Anat. u. Physiol. 
1866, p. 398. 

~ Sanders, A., Contributions to the Anatomy of the Central Nervous System in 
Vertebrate Animals. Phil. Trans. 1882. Pt. III, p. 927. 

K 2 


— 


où THE NERVOUS SYSTEM. ; 


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 Schiefferdecker, P., Beitriige zur Kenntniss des Baus der Nervenfasern. Arch. f. 
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nN 


LITERATURE. 133 


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134 THE NERVOUS SYSTEM. 


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P- 497- 

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THE NERVOUS SYSTEM. 


I. THE CENTRAL NERVOUS SYSTEM. 
(Re-written by the translator.) 


A. Tue Sprvat Corp (Fig. 97). 


1. External form. The spinal cord is, in comparison with the 
brain, somewhat small; the two organs are directly continuous, 
and present no distinct line of demarcation: the point of origin 
of the first spinal nerve is, therefore, arbitrarily accepted as the 
anterior limit of the spinal cord ; posteriorly it terminates in the 
Jilum terminale. 

The spinal cord is flattened dorso-ventrally, and is constricted 
at a point (pars media, Reissner) somewhat anterior to its 
middle: in consequence of this constriction the cord has two 
enlargements; an anterior smaller, and a posterior larger (zutu- 
mescentiae anterior v. posterior), from which arise the nerves of the 
brachial and lumbar plexuses respectively. At about the sixth 
or seventh vertebra, the hinder enlargement diminishes rather 
abruptly to form the so-called conus medullaris ; this is continued 
into the jidwm terminale, which enters the cavity of the urostyle. 
The hinder portion of the lumbar nerves forms a cauda equina, 
the constituent nerves of which surround the filum terminale. 

A dorsal longitudinal fissure (sv/cus longitudinalis superior) is 
well marked in the middle line of the dorsal surface of the pos- 
terior enlargement ; anteriorly and posteriorly it rapidly fades away, 
its position being merely indicated by a small amount of connective- 
tissue and a blood-vessel. 

The ventral longitudinal fissure (sw/cus longitudinalis inferior) is 
well marked throughout the length of the cord. Neither fissure cam 
be traced in the hinder part of the conus medullaris or in the filum 
terminale. 

Ten pairs of nerves arise from the spinal cord, each nerve arising 
by two roots, a ventral and a dorsal (anterior and posterior), from 


136 THE NERVOUS SYSTEM. 


points near the ventral and dorsal longitudinal sinuses respec- 
tively: the two roots unite at their point of exit from the ver- 


Fig. 97. 


tebral canal through 
the intervertebral for- 
amen ; each dorsal root 
possesses a ganglion. 


The nervous system of Rana es- 
culenta, from the ventral sur- 
face. (From Icones physiolo- 
gicae by A. Ecker. Pl. XXIV, 
Fig. 1.) 


Facial nerve. 

Ganglion of pneumogas- 

tric nerve. 

He Cerebral hemisphere. 

Lc Optic tract. 

Lop Optic lobe. 

M Boundary between me- 
dulla oblongata and spi- 
nal cord. 

Mx—io Spinal nerves. 

MS Connection between fourth 
spinal nerve and sympa- 
thetic chain, 

N Nasal sac. 

Ni  Sciatic nerve. 

No  Crural nerve. 

0 Eyeball. 

8 Trunk of sympathetic. 

S1—10 Sympathetic ganglia. 

Sm Rami communicantes of 
sympathetic. 

Sp Continuation of sympa- 
thetic into head. 

I Olfactory nerve. 

IT Optic nerve. 

III Motor oculi nerve. 

IV Trochlear nerve. 

Vv Trigeminal and facial 
nerves, 

Va Ramus ophthalmicus of 
trigeminal. 

Ve Ramus maxillo-mandibu- 
laris of trigeminal. 

Vd Mandibular branch of 
trigeminal, 

Ve  Hyomandibular branch of 
facial. 

Vg  Gasserian ganglion. 

Vs Upper end of sympathetic 
trunk in connection with 
Gasserian ganglion. 

VI Abducens nerve. 

VII Facial nerve. 

VIII Auditory nerve. 

x Glossopharyngeal and 

pneumogastric nerves. 


Ry 


‘Xx Ramus anterior of glosso- 


pharyngeal, 
X2 Ramus posterior of glosso- 
pharyngeal. 
X3—4 Branches of pneumogas- 
tric. 


THE SPINAL CORD. ST 


2. Internal structure. As in other vertebrates, the spinal cord 
consists of white and grey matter, the latter bemg surrounded by 
the former ; the relative amount of the one to the other varies in 
different parts of the cord. 

A transverse section of the cord presents the same general 
characteristics as a similar section from a bird or mammal. The 
grey matter lies in the middle, surrounding the central canal, and is 
prolonged into each half of the section by ventral and dorsal horns 
or cornua. The grey matter is surrounded by the white, but is 
not so sharply marked off from this in amphibia as in birds and 
mammals. 

A section through the anterior enlargement is almost quad- 
rangular in outline, and somewhat broader below than above; the 
ventral longitudinal fissure is well marked and deep, while the 
dorsal is indistinct. The dorsal horns are narrow and short, the 
ventral longer and much broader. The space between the dorsal 
horns is narrow and deep, that between the ventral shallow; the 
outer boundary of the grey matter is almost straight, and the central 
canal is placed above the centre of the section. 

In the constricted portion of the cord ( pars media) the relative pro- 
portion of the white matter is increased at the expense of the grey; 
the horns are less distinct, the dorsal being directed outwards and 
the ventral somewhat flattened. The central canal is in the centre 
of the section. 

The posterior enlargement shows the ventral horns projecting out- 
wards, very much enlarged, and approaching the periphery; the space 
between them is semilunar. The dorsal horns are well developed, 
especially at their upper parts; the space between them is narrow 
and deep. The outer margin of the grey matter is again nearly a 
straight line. The central canal is below the centre of the section. 

The arrangement of the parts in the conus medullaris approaches 
that in the pars media: the horns are much diminished in size, and 
posteriorly they entirely disappear, the ventral horns persisting longer 
than the dorsal. The central canal approaches the lower surface. 

No cornua can be recognised in the jfilwm terminale behind the 
origin of the last pair of spinal nerves. The grey matter has here 
a circular outline, with the exception of a very slight indentation” 
below ; the white matter is-almost absent: the central canal is on 
the lower border of the section in the anterior part, while posteriorly 
it occupies almost the entire space below the pia mater. 

The Central Canal lies in the median line, and always presents a 


138 THE NERVOUS SYSTEM. 


distinct lumen; in the two enlargements this lumen forms a vertical 
ellipse’, while in the pars media it is circular. The canal is lined by 
a single layer of ciliated columnar epithelium, the cells of which 
are usually conical, with their bases directed towards the lumen ; but 
other forms may be noticed. These cells average about 0-040 mm. 
in length and about 0-002 mm. in width at their broadest part. 
The peripheral extremities of the cells have processes, which, in the 
case of the cells above and below the cord, may often be traced 
as far as the pia mater; the processes of the lateral cells are less 
distinct and seem to be shorter. Anteriorly the central canal 
opens into the floor of the fourth ventricle. The termination of 
the central canal, posteriorly, has been described by Masius 
and Vanlair. According to these observers, the canal towards the 
hinder end of the fi/wm terminale increases very gradually in width, 
until its epithelial cells are immediately underneath the pia mater, 
its walls then converge somewhat more sharply to close the cavity. 
From the point where the canal commences to increase in width, 
a change takes place in its epithelial wall, which, instead of having 
a single layer of cells, now possesses two to three layers; towards 
the posterior end it is again thinned out to a single layer. 

The grey matter varies in different parts of the cord and im dif- 
ferent parts of the same section. In a section through the anterior 
enlargement a portion of the grey matter, placed immediately above 
the central canal, is easily distinguished by its vertically-placed, 
elliptical outline, and by its transparency: it is known as the sw4- 
stantia reticularis. It consists of a mesh-work of branched cells, 
through which course distinctly contoured fine commisural fibres 
which are derived chiefly from the dorsal cornua, the vertical 
from the epithelial cells of the roof of the central canal. In a 
series of sections the substantia reticulosa may be seen to originate 
indistinctly in the most anterior part of the cord; in the anterior 
enlargement it already possesses the elliptical form mentioned, and 
in the pars media it commences to send off lateral processes to either 
side. In the posterior enlargement it reaches its greatest absolute 
development, as it here surrounds the central canal; while further 
backwards it encroaches until, together with the remaining grey 
matter, it constitutes almost the whole of the fi/wm terminale. 

Immediately underneath the central canal is a narrow band, 
which immediately connects the grey matter of the two sides ; 
above it is bounded by the epithelium of the central canal, below 


1 v. Kolliker states that the lumen is everywhere circular. 


THE SPINAL CORD. 139 


by medullated fibres. This septum medium (Reissner) may be traced 
backwards from the anterior extremity of the cord to the posterior 
enlargement. It consists chiefly of transverse fibres, together with 
vertical fibres derived from the epithelial cells on the floor of the 
canal, and like the substantia reticulosa, is distinguished by its 
greater transparency from the rest of the grey matter. 

The grey matter consists of connective-tissue and nervous ele- 
ments, which are very intimately united; each of these elements 
including its special cells and fibres. The nerve-cells vary much in 
size and appearance. A prominent group of large cells in the ven- 
tral cornua, the lateral group (Stieda), is very conspicuous. The 
individual cells are seldom rounded, but are usually spindle-shaped 
or angular, and each possesses one to five processes, which may 
often be traced through considerable distances. These cells have an 
average length of o‘040 mm., and are about 0:016 mm. broad ; 
they are somewhat larger in the anterior enlargement than in the 
posterior, and are also more numerous in a section from the anterior 
enlargement than in a section from the posterior. In the terminal 
filament they gradually disappear. Some of their processes are 
continued into the lateral columns (Küppen). 

Smaller, spindle-shaped or triangular cells are scattered irregu- 
larly throughout the grey matter, without forming distinct groups, 
though for descriptive purposes those of the centre have been named 
the central group. In a stained, transverse section of the cord are 
seen numerous nuclei; these undoubtedly belong both to small 
nerve-cells and to connective-tissue cells, but except under the most 
favourable conditions the two are indistinguishable. The larger 
nerve-cells present the usual characters of nerve-cells : more or less 
granular contents, nucleus, well-marked nucleolus, more or less 
marked fibrillation ; their processes are usually more homogeneous. 
The cells are frequently pigmented. 

The processes of the cells belonging to the lateral group radiate 
in all possible directions, but certain well-marked processes directed 
towards the middle line can always be made out. From the lowest 
part of this group a few processes may be traced into the ventral 
roots. The small cells seem to be chiefly arranged vertically, al- 
though their processes radiate in all directions (Stieda). | 

The Fibres of the grey substance are nearly all non-medullated. 
They may be traced in all directions, but the best-marked groups 
are either vertical or transverse. The vertical fibres appear to arise 
from the central grey matter, and to ascend in larger or smaller 


140 THE NERVOUS SYSTEM. 


bundles towards the periphery. The transverse fibres are arranged 
chiefly in the two commissures : the dorsal commissure (commissura 
superior) is the smaller; the fibres are parallel, and show no trace 
of decussation ; externally they radiate in various directions to the 
dorsal horns. The ventral commissure is composed of two layers, the 
upper grey (commissura inferior grisea), the lower white (commissura 
inferior alba): both are interrupted by the seytwm medium. A well- 
marked decussation of the fibres is seen in the middle line ; the exact 
mode of termination of these fibres has not been made out, but many 
appear to communicate with the large cells of the ventral horns. 

The white matter consists chiefly of longitudinal, medullated 
fibres, in which various columns may be distinguished. The dorsal 
columns are separated from the lateral by a process of neuroglia, 
continued from the general investment of neuroglia lying under the 
pia mater. The line of separation between the lateral and ventral 
columns is not well marked ; it is about the line which would be 
formed by prolonging the ventral horns to the surface. 

The fibres vary in size, and fibres of all sizes may be found 
in any particular part of a transverse section ; still the fibres of the 
ventral columns have an average greater diameter than those of 
the lateral columns, and the fibres of the dorsal columns are finer 
than those of the lateral. The largest fibres of the ventral column 
are placed near the ventral fissure and on its lower border; they 
attain their greatest development in the posterior enlargement ; 
these fibres frequently contain two or three axis-cylinders each. 
Kôppen suggests that they may represent the /ormatio reticularis of 
higher animals. 

In the lateral columns the larger fibres are placed close to the 
grey matter, these columns also receive fibres from the cells of the 
lateral group. 

In the dorsal columns the radiating root-fibres never reach the 
median plane, but leave an area of purely longitudinal fibres on each 
side of the dorsal fissure ; these represent Goll’s columns, and have 
a Club-shaped outline in transverse section. 

The white matter is pierced in all directions by fine connective- 
tissue fibres and bundles of fibres which radiate from the grey matter ; 
some branch and join with others to form a network, others pass 
almost uninterruptedly to the periphery. From the connective-tissue 
cells of the pia mater, processes pass into the white matter and assist 
in completing the connective-tissue matrix for the nervous elements. 

Dorsal roots of the spinal. nerves. Each root consists of a 


THE BRAIN. 141 


single bundle of nerve fibres, which suddenly bends at the periphery 
of the cord in order to descend vertically through the white matter 
towards the dorsal horn; the fibres divide into three sets, one to 
the dorsal commissure, a second to the upper horn itself, and the 
third helps to form the dorsal columns. 

Ventral roots of the spinal nerves. Each ventral root consists 
of three or four delicate threads, which may be traced to the ven- 
tral cornua, which they reach after a vertical or very slightly 
oblique course through the white matter. Other fibres arise from 
the ventral columns, but these oblique fibres never extend to the 
median plane, 

Pigment is found distributed irtegularly through a section from 
any part of the spinal cord ; it is increased in amount in those parts 
in which there is an increased amount of grey matter. The pigmen- 
tation is always found more marked in the lower parts of the 
ventral horns than in other parts. 


B. Tue Brain (Figs. 98, 102, 103, and 105). 


1. General description. From behind forwards, the dorsal 
surface of the brain presents the following parts for examination : 
the medulla oblongata, the cerebellum, the optic lobes, the thalamen- 
cephalon, the cerebral hemispheres, and the olfactory lobes. 

The medulla oblongata is a direct continuation of the spinal cord ; it 
is wider anteriorly than posteriorly, and is separated in front from the 
optic lobes by a vertical plate of nervous matter, the cerebellum. The 
optic lobes are two symmetrical ovoid bodies touching each other in 
the median plane, and together forming the widest part of the brain. 
In front of the optic lobes is the thalamencephalon, with a thick 
vascular membrane, the choroid plexus, lying on its upper surface, 
and connected with the pineal gland ; the thalamencephalon extends 
forwards between the posterior ends of the cerebral hemispheres. 
The cerebral hemispheres are two symmetrical ovoid bodies, narrow 
in front, wider and slightly diverging behind: each hemisphere is 
prolonged forwards to form an olfactory lobe. 

The ventral surface has in front the olfactory lobes, then the 
cerebral hemispheres, behind these the damina terminalis, the tuber 
cinereum, the optic chiasma, the pituitary body, the crura cerebri, 
and lastly the medulla oblongata, in the order here given. 

The various cranial nerves (Figs. 102 and 103) may be seen to 
arise as follows:—The olfactory nerve (J, 7’, Lol”) arises directly 


142 THE NERVOUS SYSTEM, 


from the anterior end and outer side of the corresponding olfactory 
lobe, and from the cerebral hemisphere. The optic nerve (70 and 
IT) arises, as the optic tract, from the side of the brain below the 
optic lobe, whence it passes to the chiasma on the under surface of 
the brain. The oculo-motor (///) takes its origin from the ventral 
surface close to the median line and between the erwra cerebri. 
The pathetic or trochlear nerve (J/) is attached to the dorsal 
surface between the optic lobes and the cerebellum. The trige- 
minal nerve (Ÿ) arises from the side and anterior part of the 
medulla oblongata. The abducens (V1) arises behind the pituitary 
body close to the median line from the ventral surface of the 
medulla halfway between the sw/eus and the origin of the vagus. 
The facial and auditory (/// and VJII) nerves arise from the 
medulla oblongata behind the trigeminal nerve, the facial being 
in front of the auditory nerve. The glossopharyngeal (7X) nerve 
arises, in common with the pneumogastric nerve (X), behind the 
auditory nerve. 

2. The several parts of the brain. 

a. The medulla oblongata (Figs. 98, 102, and 103 Mo)—a. External 
form. The medulla is limited behind by the origin of the first pair 
of spinal nerves, at which point a very faint constriction is sometimes 
found : it extends forwards as far as the cerebellum. It gradually 
widens as it passes forwards until just before it reaches its anterior 
limit, where it presents a shallow but sharp constriction. The 
dorsal surface is characterised by the presence of a deep, triangular 
fossa, the fourth ventricle (Fig. 98 Sr), (ventriculus quartus, 
Stieda; sinus rhomboideus s. sinus triangularis, Reissner; fossa 
rhomboitalis) ; the sides of the triangle are, however, not quite 
straight, but are slightly bent outwards just before they converge 
towards the posteriorly-directed apex; the base of the triangle 
is formed by the cerebellum. By careful examination, the ventricle 
is seen to be continued for a short distance under the cerebellum, 
where it opens into the Sylvian aqueduct. In the floor of the fourth 
ventricle is a well-marked median longitudinal fissure (sw/cus cen- 
tralis), (Fig. 98 8). Into the posterior part of the ventricle opens the 
central canal of the spinal cord. As the fourth ventricle is formed 
by the white matter passing to either side, and the simultaneous 
flattening of the grey matter, the floor of the fourth ventricle is 
composed of grey matter. 

The fourth ventricle is closed in by a highly vascular mem- 
brane, the choroid plexus of the fourth ventricle (pleaus cho- 


THE MEDULLA OBLONGATA. 


rouleus ventriculi quarti, Reissner; velum medullare posterius). 


143 
The 


blood-vessels of the plexus will be described together with the 


other vessels of the brain (p. 162). They 
are supported by à connective-tissue matrix, 
and the whole covered with flattened epi- 
thelium, which in the fourth ventricle is 
ciliated and often pigmented. 

The ventral surface of the medu/la ob- 
longata (Fig. 102 Mo) has a median ventral 
longitudinal fissure, a direct continuation of 
that of the cord; in the anterior part of the 
medulla oblongata there is also to either side 
of this a lateral fissure, continued on to the 
crura cerebri; these fissures correspond to 
the positions of the two rami posteriores of 
the internal carotid arteries ; they are always 
well seen in microscopical sections. The 
medulla oblongata is so intimately connected 
with the pars commissuralis (pp. 149, 150) 
that the minute anatomy of the two is best 
described at the same time. 

B. Internal structure. Examined by 
means of serial sections, the medulla oblon- 
gata 1s seen to have, in comparison with the 
cord, an increased amount of grey matter ; 
this is especially the case in its anterior part. 
The floor and inner parts of the walls of 
the ventricle are formed of grey matter, in 
which the largest-sized cells have disap- 
peared, to be replaced by medium-sized 
cells. Traced from behind, the ventral 
horns of the cord are seen to increase in 
size and to be more widely separated until 
they form two isolated masses, while the 
dorsal horns gradually diminish; at the 


Dorsal view of brain of Rana 
esculenta, 


G 


Gp 
He 
I 

Li 
L.ol 
L.op 
Mo 
S 


S.r 
Tho 


same time they are forced outwards and upwards, 
the floor of the ventricle, and so extend to the pars peduncularis. 


Grey matter. 


Choroid plexus, 

Cerebellum. 

Groove between cerebral 
hemispheres and olfactory 
lobes. 

Opening in the roof of the 
third ventricle. 

Pineal body. 

Cerebral hemispheres. 

Olfactory nerve. 

Wall of fourth ventricle. 

Olfactory lobe. 

Optic lobe. 

Medulla oblongata. 

Longitudinal fissure of the 
fourth ventricle, 

Fourth ventricle. 

Thalamencephalon, 


until they lie under 


The substantia reticularis is not present, but the 


septum medium extends forwards as far as the pars peduncularis. 
The central canal extends upwards at the expense of the tissue 
above it, and is here pear-shaped; at the same time the dorsal 


144 THE NERVOUS SYSTEM. 


longitudinal fissure deepens until the two meet in the fourth ven- 
tricle; beyond this point one cannot speak of dorsal and ventral 


horns. 
Small nerve cells are irre- 


eularly distributed through- 
out the whole of the grey 
matter and cannot be 
grouped; the larger cells, 
on the other hand, are 
arranged in distinct groups 
which have special relations 
with the nerves arising 
from the part. Occasion- 
ally these groups are not 
so isolated as usual; in 
this case processes of one 
group can be traced into 
another group (Reissner). 
Of these groups the chief 


Transverse section through hinder end of Medulla are: 
oblongata (mugnified 30-80)1, from Stieda, 
b Inferior commissure. 1. The nucleus centralis 
f Dorsal horns, : Z : 
9. Wenteal hors. (upper inner group, Reiss- 
h Fourth ventricle. ner), nucleus medullae oblon- 


à Nucleus centralis. z : ee 
k Isolated mass of grey matter in which longitudinal gatae, Stieda (Fig. 99 2), Is 


fibres of the pneumogastric nerve course. a group of cells found to- 
wards the hinder end of the medulla oblongata, on either side of and 
below the central canal; the group can be traced under the floor of 
the fourth ventricle to about its middle. The cells are rounded or 
spindle-shaped, the processes directed upwards, downwards, or out- 
wards ; their average size is 0°040-0'048 mm. long by 0020 mm. 
broad. 

2. The auditory nucleus (xucleus acusticus, Reissner, Stieda), 
(Fig. 100 ») is a large group of cells found in the wall of the 
fourth ventricle opposite the point of origin of the auditory nerve. 
The cells are rounded, pear-shaped, or of spindle form, and inter- 
spersed between the nerve fibres; these cells have an average 
length of o‘o40 mm., and are about half as broad. The fibres 
of the auditory nerve radiate from their superficial origin in all 

1 In these diagrams, from Ludwig Stieda’s Studien über das centrale Nervensystem 


der Wirbelthiere, the outline of the diagram is magnified thirty times, while the 
details are magnified eighty times. 


THE MEDULLA OBLONGATA. 145 


directions through the grey matter towards these cells, and evidently 
communicate with them (Fig. 101 p). One small group (Fig. 101 7) 
passes to a lower level than the rest, and is regarded by Stieda as 


Fig. 100. 


Transverse section through the Medulla oblongata at the point of origin of the abducens nerve, 
from Stieda. Magnified 30 x 80.) 


h Fourth ventricle. 
m  Abducens nerve. 
n Auditory nucleus. 
o  Abducens nucleus, 


the true auditory centre. Küppen considers that the auditory nerve 
has a threefold origin: (1) from small cells on the median surface 
of the auditory area; (2) from the large cells between the above ; 
(3) from a group of free nuclei on the dorsal surface of the auditory 
area. 


3. The trigeminal nucleus (nucleus trigeminus), (Fig. 101 q) 
lies in part beneath the auditory nucleus but extends further 
forwards. It forms a rounded group of cells placed under the outer 
angle of the grey matter. The cells are somewhat crowded together, 
and are chiefly of an elongated spindle-form, with their processes 
directed obliquely downwards and outwards. The fibres of the trige- 
minal nerve separate into two groups ; the upper group is best traced 
in a horizontal section, the fibres curving round to join the longitu- 
dinal fibres continued from the dorsal columns of the cord. The 
fibres of the lower, smaller group pass transversely inwards to the 

L 


146 THE NERVOUS SYSTEM. . 


trigeminal nucleus. According to Reissner the latter fibres are 
motor, the former sensory. Probably other nerves are connected 
with the hinder part of this group. 

4. The abducens nucleus (Fig. 100 0). From its superficial 
origin, the fibres of the abducens nerve may be traced vertically 
upwards to a small, rounded, grey mass; at this point the mass 
is somewhat isolated, but further forwards it may be traced 
as belonging to the central grey matter; it contains small spindle 
cells. 


Fig. 101. 


Transverse section of the Medulla oblongata, at the point of origin of the auditory nerve, from 
Stieda, (Magnified 30 X 80.) 


h Fourth ventricle. 

nm Auditory nucleus. 

o  Abducens nucleus. 

p Auditory nerve. 

p’ Ganglion of auditory nerve. 

q Hinder portion of trigeminal nerve. 

r X acHe of fibres arising from trigeminal nucleus and joining the auditory nerve. 


5. The pneumogastric nucleus. The pneumogastric, with its 
numerous irregular roots, arises from the side of the medulla ob- 
longata. The hindermost fibres can be traced as a small bundle, 
passing almost transversely through the white matter to the outer 
margin of the grey matter. The larger portion of the fibres is 
placed in front of these; part of this seems to be directly con- 
tinuous with the longitudinal fibres of the white matter; a 
second part, however, can be traced from the surface transversely 


THE MEDULLA OBLONGATA. 147 


through the white matter to the grey matter. These latter fibres, 
together with those of the group first described, do not arise from 
the grey matter in this part of the medulla oblongata, but curve 
round and run backwards longitudinally through the grey matter, 
thus forming a rounded bundle of fibres (Fig. 99 4). Between these 
fibres are interspersed small nerve-cells and nuclei which disappear 
as the fibres approach the white matter. The vagus undoubtedly 
receives fibres from the grey matter throughout a long course, 
and again receives a large bundle just before leaving the grey 
matter. The more exact origin of the various fibres has not been 
traced. ; 

6. The nucleus magnus (Reissner and Stieda) is a very peculiar 
group of cells placed on either side, in the most anterior portion of 
the pars commissuralis, that is, immediately underneath the valvula 
cerebelli. The large cells are arranged in a transverse section in a 
single row so as to enclose a pear-shaped space on either side, which 
has its long axis directed from above, downwards and outwards, the 
narrower end being above. In longitudinal section the line of cells 
is seen to be open im front. The space enclosed by these cells is 
occupied by a granular ground-substance which contains only few 
nuclei. Bellonci is of opinion that these nuclei represent the corpora 
quadrigemina posteriora of higher animals. 

White matter. In the hinder part of the medulla oblongata the 
arrangement of the white matter resembles that of the white 
matter of the spinal cord; further forwards the white matter of 
the dorsal surface commences to pass to either side, and ultimately 
it forms the outer part of the walls of the fourth ventricle. The 
fibres of the white matter of the ventral surface are unchanged in 
direction as they proceed forwards. The fibres of the anterior part 
of the medulla are thinner than those of the posterior portion 
(Stieda), according to Reissner they gradually thin as they pass 
forwards. The fibres are nearly all longitudinal, sueh transverse 
and oblique fibres as are present being chiefly in conMetion with 
the various nerve-roots and the commissures. 

The commissura superior is naturally lost in consequence of the 
opening of the central canal into the fourth ventricle; the cow- 
missura inferior is increased in the anterior half and decreased in 
the posterior half of the medulla oblongata; in the latter the 
fibres become more and more oblique, and decussate very freely ; 
ultimately they seem to be either continued as longitudinal fibres or 
to join the ganglia. 


L 2 


148 THE NERVOUS SYSTEM. 


Near the pars commissuralis is a transverse arched band of fibres, 
passing from the under surface of one half of the cord over the 
ventral longitudinal fissure through the septwm medium to the under 
surface of the opposite half ; part of the fibres are continued up- 
wards along the periphery to the cerebellum, part to the nucleus 
magnus. Vertical, straight, or slightly arched fibres are found in 
the walls of the fourth ventricle. 

A section from the wedulla oblongata has a larger amount of 
pigment than a section from the spinal cord, and the anterior portion 
of the medulla oblongata contains more than the posterior portion. 
The pigment is chiefly found in a curved line, placed in the lower 
and outer parts of the grey matter; the amount present varies in 
different specimens. 


b. The Cerebellum and Valvula cerebelli. 

a. External form. The cerebellum is a thin, semilunar plate, 
which projects between the optic lobes and the fourth ventricle, 
its base covering the most anterior part of the ventricle; the 
posterior surface possesses a very faint median fissure (Reissner). 
The valvula cerebelli (Velum medullare anterius, Reissner) is the thin 
lamella which connects the anterior surface of the cerebel/um with 
the optic lobes. 

8. Minute structure. By means of longitudinal, vertical sec- 
tions, the posterior surface of the cerebellum is seen to be covered 
with epithelium ; in the lower part of the surface this is columnar 
or conical, above it is flattened: immediately beneath, that is in 
front of this is a finely granular layer, with very closely packed and 
granular nuclei. In front of these is a stratum of nerve-fibres 
forming the second layer of the cerebellum. 

Still more anteriorly is the third layer of the cerebellum, an 
irregular double layer of large cells (Purkinje’s cells, Denissenko) ; 
the cells have an average length and breadth of o-o40 mm. and 
0‘015 mm. respectively ; they are pear-shaped or of spindle-form, 
and possess usually two well-marked processes, one passing’ into 
the layer behind, the other forwards into the anterior layer to be 
immediately described, while other less distinct processes radiate 
irregularly in all directions. The fourth and most anterior layer 
of the cerebellum is a thick stratum of nerve fibres with numerous 
nuclei (0°006 to o‘008 mm. diameter). The fibres are for the 
most part arranged transversely, but some course in various direc- 
tions. These fibres underlie the flattened epithelium which covers 
the anterior surface of the cerebellum. 


THE 


The fibres of the second layer 
course, for the most part, in an almost 
vertical plane; they connect the cere- 
bellum with the optic lobes (processus 
cerebelli ad corpora bigemina) and with 
other parts of the brain. 

The fibres of the fourth layer re- 
ceive numerous long processes from 
the large cells of Purkinje; they form 
a large commissural system, which can 
be followed ventrally on each side into 
the pars commissuralis. A part of the 
fibres ends here in the grey matter, a 
second portion enters the auditory area 
and forms a descending auditory root, 
a third part joins the lateral columns 
(in the medulla oblongata), and more an- 
teriorly some join the ventral columns. 
The descending fibres from the cere- 
bellum, together with the jfibrae arcu- 
atae found in the ventral columns, 
indicate the presence of a pous Va- 
rolii. The fibres of this ventral com- 
missure decussate only on its dorsal 
surface (Küppen). : 

The Valvula cerebelli contains a few 
medullated fibres and the roots of the 
trochlear nerves; these pass from the 
medulla into the valvula 
cerebelli, cross in the median line, and 
then proceed forwards as the troch- 
lear nerves. 


oblongaia 


The pigment in the pars commissu- 


CEREBELLUM, 


Ventral view of brain of Rana 
esculenta. 


Cho 
He 
Hy 
Lol 
Loh 


Lt 
Mo 
To 
Tu.c 
I 1st 


Il en 


IT 

TT) 
IV 
VI 


LUE 


Optic chiasma. 

Cerebral hemispheres. 

Pituitary body. 

Olfactory lobe, 

Origin of olfactory nerve from 
the cerebral hemisphere. 

Lamina terminalis. 

Medulla oblongata, 

Optic tract. 

Tuber cinereum. 

a k root of the olfactory nerve. 

Optic nerve, 

Oculo-motor nerve, 

Trochlear nerve. 

Abducens nerve. 

IT, VIIL Trigeminal, facial, and 
auditory nerves. 


IX, X, XI Glossopharyngeal, pneumo- 


gastric, and accessory nerves. 


ralis 1s arranged in a curved line similar to that found in the we- 
dulla oblongata, but the line is shortened at either extremity, and 
consequently does not extend into the cerebellum. 


c. The optie lobes and Crura cerebri. 


(Corpora geminata and 
\ 


Pars peduncularis, Reissner ; Lobus opticus, Stieda; Vierhiigel, 
Tiedemann ; Vierhiigel (Zweihiigel) and Peduneuli cerebri, Schiess ; 


Mesencephalon, Huxley.) 


150 THE NERVOUS SYSTEM. 


a. External form (Figs. 98, 102, 103 L.0p). The optic lobes 
are two promi- 
nent ovoid bodies 
placed immedi- 
ately in front of 
the cerebellum, 
and connected 
with it by the 
valvula cerebelli ; 


LP D : 
ws posteriorly they 
IT Tue Hy Mo touch each other 
Lateral view of brain of Rana esculenta, in the median 
Ad Choroid plexus. Tu.c Tuber cinereum. plane, while an- 
C Cerebellum. T ist : RE ee : ; : 
Gp Pineal body. Tana $ root of olfactory nerve. teriorly they di- 
He Cerebral hemisphere. II Optic nerve. 
Hy Pituitary body. IV Trochlear nerve. verge and thus 
Lol Olfactory lobe. V Trigeminal nerve. constitute the 
L.oli Dise at origin of second root. VII Facial nerve, : 2 
L.op Optic lobe. VIIT Auditory nerve. widest part of 
Mo Medulla oblongata. IX, X, XI Glossopharyngeal, pneumo- oy OPA © 
Tho Thalamencephalon. gastric, and accessory nerves, the brain _ the 
To Optic tract. anglethus formed 


is the thalamencephalon. The optic lobes are always more darkly 
pigmented than any other part of the central nervous system. 

The Crura cerebri are two columns of white matter, placed beneath 
the optic lobes, and partly hidden by the pituitary gland. At their 
junction with the medulla oblongata, or rather with the pars com- 
missuralis, is a very slight transverse fissure ; at the same point the 
ventral longitudinal fissure is interrupted by an extremely small 
grey tubercle (Stieda). 

8. Internal structure. From the anterior extremity of the 
fourth ventricle a canal, the Sylvian aqueduct (Aqueductus Sylvii, 
itera tertio ad quartum ventriculum), may be traced forwards under 
the cerebellum, in the median line of this section of the brain. At 
about opposite the middle of the length of the optic lobes the canal 
is dilated and communicates with He cavities or ventricles (Ventri- 
culi tobi optici, Stieda) enclosed by these; a general cavity is 
formed, which in transverse section has something of the form 
of the letter T. The roof of the cavity is thinner than the floor ; 
this is especially the case in the median plane opposite the superior 
longitudinal fissure between the optic lobes; the floor is thinned 
in the middle line by the descending portion of the cavity. The 
cavity of each optic lobe extends both forwards and backwards 
beyond its point of communication with the dilated Sylvian aque- 


THE OPTIC LOBES. 151 


duct, hence in a transverse section taken in front of this pomt 
(Fig. 104 4’) the cavity of either side appears to be isolated; in 
a horizontal and longitudinal section (Fig. 105 dq) the general 
arrangement of the parts may be well seen. 

The grey matter 
is chiefly arranged 
in a layer so as to 
surround the cavity 
(Fig. 104), this layer 
being deeper on 
either side of the 
descending portion 
of the cavity than 
elsewhere. For the 
rest the grey matter 
is much interspersed 
among the white 
matter, except at the 
circumference of the 
section, which is en- 
tirely formed of white 
matter. It contains 
a large number of 
small cells, of which 


the nuclei are alone 


visible ; in the parts Transverse section through the anterior portion of the optic lobes 
opposite the origin of the motor-oculi nerve ; from Stieda (mag- 


mentioned where the nified 30-80). 
layer is most marked h Lower portion of cavity. 

à s , D h’ Lateral portion of cavity. 
these cells ae rf sae u Ganglia of oculi-motor nerve. 
ranged in oblique v  Oculo-motor nerve. 

: w Large cells of the optic lobe. 
rows, between which æ Roof of optic lobe. 


y Posterior commissure. 
z Anterior diverticulum of the cavity. 


pass fine bundles of 
medullated fibres 
(Fig. 104, between # and 4’). A group of large cells (Fig. 104 ~) 1s 
found on either side of the middle line and under the floor of the cavity ; 
the cells are about 0'032 mm. long, and 0‘016 mm. broad ; the oculo- 
motor nerve may be traced to this group, which is the oculo-motor 
nucleus. A small commissure of decussating fibres connects the 
nuclei of opposite sides (Küppen). 

The substance of the roof of the optic lobes (Fig. 104 #) is 
arranged in very distinct layers: above is a layer free from cells ; 


152 THE NERVOUS SYSTEM. 


the fibres of this layer are extremely fine and delicate, and have 
not been accurately traced ; under this is a nuclear layer ; a second 
layer of fine fibres follows, which is succeeded by a second layer of 
nuclei ina granular matrix, and lastly epithelium (Stieda). (Reissner 
describes three nuclear layers: in Bufo variabilis, and this is also the 
case in À. temporaria, G. H.; according to Képpen, the number is 
variable.) In the anterior portion of the roof a distinct bundle of 
fibres may be made out; externally they bend downwards, and can 
be traced as far as the erwra cerebri. 

Fibres corresponding with the commissural and arched fibres of 
the medulla oblongata are continued into the hinder portion of the 
crura cerebri, the change from pars commissuralis to crura cerebro 
being very gradual. The longitudinal white fibres are much in- 
creased in number in the crura cerebri, and a portion of them can 
be traced to the nucleus magnus. 

A peculiar irregular group of large cells (Fig. 104 w) is found 
where the roof meets the erwra cerebri ; these vary in diameter from 
0°'024 to 0‘040 mm., and their processes are very indistinct. 

The fibres of the optic tracts arise, according to Küôppen, from 
two different origins: the one lies on the hindermost part of the 
optic lobe ; from this point the fibres curve downwards and forwards 
to form longitudinal fibres; this root Képpen names the ventral 
ascending root, it can be traced through the entire length of 
the organ. The second root arises in the ¢ectwm opticum near the 
longitudinal fissure; it is smaller than the foregoing, and has 
been named the dorsal ascending optic root. The fibres of these 
two roots unite anteriorly near the posterior commissure, at which 
point they receive additional fibres (Képpen). Bellonci traces a 
large proportion of the fibres of the optic tract to the nucleus 
magnus, which pair of nuclei, as already stated, he regards as the 
posterior pair of corpora quadrigemina of higher animals. 

The pars peduncularis is the continuation of the pars commissu- 
ralis underneath the optic lobes; a gelatinous mass lying in the 
median plane and containing numerous isolated nuclei (Ganglion 
interpedunculare) divides it into two lateral halves. The longitu- 
dinal fibres are ungrouped posteriorly, but arranged in rounded 
strands in the middle, especially dorsally; anteriorly the grouped 
arrangement is lost and the number of fibres dimimished. 

The pigment of this region has, in a transverse section, an outline 
which has something the form of a lyre ; commencing on either side 
of the median line, and underneath the deepest portion of the cavity, 


THE THALAMENCEPHALON. 153 


the pigment line passes, first, directly outwards ; then suddenly turns 
upwards and slightly outwards parallel with the wall of the deeper 
part of the cavity; it then curves outwards to pass below the cavity of 
the optic lobe, where it divides, one portion passing outwards, the other 
between the Sylvian aqueduct and the ventricle of the optic lobe. 

d. The Thalamencephalon (Huxley), (Lobus ventriculi terti, 
Stieda ; Thalami optici, Reissner ; Thalamus opticus s. Lobus ventri- 
culi tertii, Stannius ; Ganglien der Haemisphaeren, Carus). 

a. External form. From above (Fig. 98 740) the thalamence- 
phalon is seen as a lozenge-shaped mass lying in front of the optic 
lobes, and behind and between the diverging posterior ends of the 
cerebral hemispheres ; it is covered by a thick vascular membrane, the 
choroid plexus, through which passes the pedicle of the pineal 
body (Glandula pinealis). On removing the choroid plexus a small 
aperture is seen in the roof of the thalamencephalon, connecting 
the hollow pedicle of the pineal gland with the third ventricle. 
The ventricle appears as a narrow slit in the median line, its 
walls being formed by the optic thalami. By Fig. 105. 
pressing aside the cerebral hemispheres the pos- 
terior commissure (Commissura posterior) may 
be seen lying quite in front and deep in the 
cleft of the ventricle. Immediately behind the 
pedicle of the pineal body is a slight but well- 
marked depression (Fig 98 G), the origin of 
which has not been investigated (Wiedersheim). 

The choroid plexus is continued forwards 
between the cerebral hemispheres (Figs. 98, 
103 Ad) for some distance, and terminates in 
a fine thread of connective-tissue. 

The under surface of the thalamencephalon 
(Fig. 102) is divided into two parts by the 
optic chiasma (C/o): the anterior portion 
(Lt) is the lamina terminalis (Substantia cinerea 
anterior); the posterior (7%.c) the tuber cine- 
reum. The lamina terminalis is bounded on 
either side by the cerebral hemispheres. The pe REA ie ee 


the brain to show the ven- 


‘ sec Ca noes sh tricles 
VL o a S 5 L 
tuber cinereun (Figs. 102, 103 Tu.c) is à small Net oe ul lobes 
median swelling immediately behind the optic and the aqueduct of 
. = Sylvius. 
chiasma, and caused by the depression of the py Third ventricle. 


1 : ie = s MF Foramen of Monroe, 
floor of the third ventricle to form the infun- D foramen ot won 


dibulum (Diverticulum infundibuli, Reissner). Vv Fourth ventricle. 


154 THE NERVOUS SYSTEM. 


The pituitary body (Hypophysis cerebri) is a flattened sac, placed 
behind the fuber cinereum and continuous with it by means of the 
enfundibulum. 

B. Internal structure. he aqueduct of Sylvius, after commu- 
micating with the ventricles of the optic lobes, again contracts 
(Fig. 105), but still remains somewhat larger than before. In the 
thalamencephalon the Sylvian aqueduct opens into the third 
ventricle, which gradually assumes the form of a vertical slit with 
the walls bulging slightly outwards in their upper parts. The 
thin roof of this ventricle, where complete, contains a band of 
transverse fibres. The floor is depressed both before and behind 
the part immediately above the optic chiasma, the posterior de- 
pression lymg above the ¢uber cinereum, which here descends 
towards the infundibulum: a transverse section through this por- 
tion of the third ventricle has the form of a square standing on 
one angle, the superior angle being produced into the vertical 
slit of the general cavity. The anterior depression is formed 
by the general cavity being prolonged downwards and forwards to 
the Zamina terminalis in the form of a narrow and shallow slit. 

The white and grey matter of the thalamencephalon are only so 
far distinct im that the portion immediately surrounding the cavity 
is darker than the rest of the section. In the immediate neighbour- 
hood of the cavity are many small cells and nuclei, which become 
searcer further from the ventricle; they are arranged in rows, 
separated by a fibrillated matrix. On either side is a distinct bundle 
of longitudinal fibres, the ‘round bundle’ of K6éppen, which come 
from the optic lobes but appear to arise from either the pars com- 
missuralis or the medulla oblongata, and to receive additional fibres 
from the optic thalami; they pass forwards to the base of the 
cerebral hemispheres (Stieda). A second set of longitudinal fibres 
arises in the substance of the ¢wher cinereum and passes forwards 
to the hemispheres (strand of the Zuber-cinereum and Thalamus, 
Koéppen); this band, together with the ‘round bundle,’ form a erus 
cerebri (Küppen). 

The commissural fibres of the thalamencephalon are : (1) a com- 
missura transversa Halleri in the posterior portion of the organ ; 
(2) an optic commissure, consisting of fibres arising from the thala- 
mencephalon (thalamencephalie root) and crossing the median line 
to join the optic tract of the opposite side; (3) a probable com- 
missure between the optic nerves just in front of the chiasma 
opticorum ; the existence of the latter is not yet proved beyond 


THE PITUITARY BODY. 155 


doubt ; (4) the large commissure of transverse fibres found in the 
roof of the third ventricle ; whether the fibres decussate or not is 
uncertain (K6ppen). 

The fibres of the large commissure of the roof are, in part, con- 
tinued into the strand of the T'uber-cinereum above mentioned, and 
thus conducted to the posterior parts of the hemispheres (Koppen). 
A group of fibres (Meynert’s band, Koppen) is found in each lateral 
wall of the third ventricle; they pass from the region of the nucleus 
parvus downwards in a curved course almost parallel with the ex- 
ternal border of the thalamencephalon. 

A distinct group of cells may be noted in this section of the brain, 
an arciform or circular group (Nucleus parvus, Reissner ; ganglion 
of the Aabenula, Koppen) of large spindle cells (average diameter 
0‘016 mm.), placed under the upper border close to the third ven- 
tricle; the group extends alongside the whole length of the 
ventricle. A second group lying in the middle and posterior parts 
beneath the ventricle, Küppen names the ‘ ventral nucleus’ of the 
thalamencephalon. 

The pigment in the posterior part of the thalamencephalon is 
arranged in a manner similar to that in the optic lobes and erura 
cerebri; anteriorly where the third ventricle is prolonged forwards 
and downwards the arrangement is different ; the pigment les in 
a curved line above the process of the ventricle, with its concavity 
directed downwards, each end bifureating, in order that one branch 
may pass upwards, the other downwards. 


The pineal body ! is a small vesicle placed underneath the skin 
above the fronto-parietal bones ; in the embryo it is connected with 
the third ventricle by means of the pedicle? already mentioned ; the 
skin covering the body is always paler than the surrounding skin, and 
the usual cutaneous glands are absent in this part ; the paler spot on 
the head may always be found, but is more distinct in Rana tempo- 
raria than in Rana esculenta. The structure on the roof of the third 
ventricle, which is usually known as the pineal body, is nothing more 
than a thickened portion of the choroid plexus, and consists of a 
group of convoluted vessels surrounded by pia mater, which is de- 
scribed by Wyman as being covered with ciliated epithelium (2. 
pipiens). The true pineal body is a small body with an outer con- 


! Compare Ehlers, Ueber die Zirbel der Haifische, Zeit. f. wiss. Zool. 1878, Vo . 
XXX ; and Balfour, Development of the Elasmobranch Fishes, chap. ix. 

? Wiedersheim states that the pedicle is hollow, and regards the part formerly 
known as the pineal body as a thickened portion of this pedicle. 


156 THE NERVOUS SYSTEM. 


nective-tissue capsule, derived from the pia mater ; this encloses an 
irregular mass of epithelial cells; according to de Graaf a twig of 
the ramus supramaxillaris reaches it subcutaneously, and a blood- 
vessel accompanies the pedicle through the foramen parietale. Ac- 
cording to Darkschewitsch, the pedicle contains medullated nerve- 
fibres derived directly from the brain. 

The pituitary body (Figs. 102, 103 Hy) when examined with 
a lens is seen to consist of two portions: an anterior, superior, and 
smaller white portion, and a larger, inferior, posterior, and reddish 
portion. The anterior portion has the form of a very small, flat 
disk, and is enclosed in a connective-tissue capsule which sends 
in larger and smaller processes. In either transverse or longitu- 
dinal section it is seen to be formed of two horizontal layers 
separated by a line of blood-vessels and connective-tissue. The 
upper layer consists of a granular and reticular matrix, containing 
many nuclei (averaging 0°006 to o‘o10 mm. diameter), and divided 
into irregular rounded or polyhedral spaces by bands of tissue 
derived from the capsule. This layer is more vascular than the 
lower. The lower layer consists of a mass of clear, nucleated 
rounded or polyhedral cells (0°016 to 0024 mm. in diameter ; 
nuclei from o‘008 to o‘o12 mm. in diameter, Reissner), pierced 
by very fine connective-tissue septa derived from the capsule. 
The septa are, for the most part, vertical and longitudinal 
(Reissner), the blood-vessels are very few. 

The posterior larger portion of the pituitary body (Fig. 106) is 
also compressed from above downwards, and in transverse section 
as an oval outline. It possesses an external thin connective- 
tissue capsule, which sends in fine processes to support a mass 
of convoluted tubes, between which course a few blood-vessels ; 
these tubes possess an outer nucleated basement-membrane, and 
are lined with a single layer of more or less cylindrical epithelium, 
which entirely fills the tube; hence the tubes possess no lumen. 
The tubes are from o-04 to 0:08 mm. in diameter ; the cells are 
clear or granular, and possess distinct, rounded nuclei. 

e. The Cerebral Hemispheres and Olfactory Lobes. The 
cerebral hemispheres (Loli hemisphaerici, Stieda ; Loti cerebrales, 
Reissner ; Centralmasse des Geruchssinns, Carus ; Hemisphaeren 
des grossen Hirns, Tiedemann; Grosse Hemisphaeren, Schiess ; 
Prosencephalon, Huxley). The olfactory lobes (Zubercula olfac- 
toria, Stieda ; Lobi olfactorii, Reissner ; Riechkolben, Schiess ; Rhi- 
nencephalon, Huxley). 


THE CEREBRAL HEMISPHERES. 154 


a. External form (Figs. 98, 102, 103 He and L.o/). The two 
cerebral hemispheres form together the largest section of the 
brain ; from above they are seen to be separated by a dorsal lon- 
gitudinal fissure, which is here well marked : each hemisphere is an 
ovoid body with the smaller end directed forwards and continuous 
with the corresponding olfactory lobe; the Fig. 106. 
posterior end forms one half of the anterior 
boundary of the thalamencephalon. The 
olfactory lobes are two elongated, rounded 
bodies directly continuous with the cor- 
responding: cerebral hemispheres, and like- 
wise partially separated in the median line 
by a dorsal longitudinal fissure: at the section through the lower division 
point of union of the cerebral hemispheres of the Poe ie spin 
and olfactory lobes is a faintly marked a ubés Inved with epithet 
transverse depression. HET 

On the ventral surface the parts are again marked off from 
one another by a corresponding ventral longitudinal fissure and a 
transverse groove; the two longitudinal fissures being continuous, 
anteriorly, between the olfactory lobes. The cerebral hemispheres 
appear to be more widely separated behind (Fig. 102) than is 
the case on the dorsal surface, and in the space so formed is 
the lamina terminalis (Lt). Seen from the side, the slight depres- 
sion of the upper surface, between the cerebral hemispheres and 
the olfactory lobes, is seen to be continued downwards and 
slightly backwards to join the corresponding groove on the inferior 
surface. 

The longitudinal fissures are shallow and do not meet, except 
at one point, at about the middle of the cerebral hemispheres 
(Fig. 105). The olfactory bulbs arise superficially (Figs. 102, 103 I’ 
and L.0/) from the whole length of the olfactory lobe, between the 
anterior extremity (/’) and the posterior (Z.0/), where they are also 
attached to the cerebral hemispheres. 


8. Internal structure. The cerebral hemispheres and olfactory 
lobes are hollow, the common cavity of each side being known 
as the lateral ventricle (Ventriculus lateralis); these ventricles 
communicate with each other, and with the third ventricle 
(Fig. 105). The narrow aperture by which the lateral ventricles 
communicate is known as the Foramen of Monro (H/F); it 
communicates with the third ventricle posteriorly, and with the 
space between the cerebral hemispheres anteriorly, and thus forms 


158 


THE NERVOUS SYSTEM. 


a common cavity (Ventriculus communis loborum hemisphaericorum, 


Stieda). 


In general terms, each ventricle may be said to be a semilunar 
cavity, prolonged backwards and forwards (Fig. 107 c); the outer 


Fig. 107. 


section 
hinder 


Transverse 
through the 
portion of the cere- 


bral hemispheres ; 
from Stieda. 


ce Lateral ventricle. 

ec’ Common ventricle 
of Stieda. 

d Longitudinal fibres. 

J Anterior prolonga- 
tion of the third 
ventricle. 


obtained. 


wall is always more or less concave, while the 
inner varies according to the part of the hemi- 
sphere examined. At the anterior and posterior 
extremities the inner wall is convex and bulges 
into the cavity (Fig. 107); in the middle portion 
of the cavity the inner wall presents a longi- 
tudinal groove (Ventriculi lateralis cornu inter- 
num, Reissner), (Fig. 108 4), and consequently 
the inner wall has here two rounded masses, an 


_ upper and a lower (Corpus striatum, Wiedersheim), 


projecting into it. By tracing them backwards 
and forwards, the lower swelling is seen to in- 
crease at the expense of the upper, while at the 
same time the lateral grooves disappear; the 
outline of the cavity shown in Fig. 107 is then 


The roof of the ventricle is arched and broader than 


the floor, which, in the middle part, exists only as a vertical slit 
(Fig. 108), (Ventriculi lateralis cornu inferius, Reissner): towards 
the anterior and posterior extremities it widens and becomes 


shallower (Fig. 107). 


Fig. 108. 


Transverse section near 
the middle of the cere- 
bral hemispheres, 

€ Lateral ventricle. 

d Groove on the inner 

wall, 


The cerebral hemispheres and olfactory lobes 
are composed of a fine granular matrix, enclosing 
spindle-shaped, rounded, or pear-shaped nerve 
cells and nuclei, and containing very fine fibres. 
The cells (Fig. 109 4) are more numerous towards 
the ventricle, and somewhat sparse towards the 
superficial surface. The cells are of two chief 
sizes, the smaller and more numerous average 
0‘004 mm. to 0‘008 mm. in diameter; they are 
found chiefly in the deeper portions of the 


section, but also form a very thin irregular 
layer beneath the pia mater: the larger cells have an average 
diameter of o‘o10 mm. to o‘o12 mm., and are placed towards 
the periphery, especially in the dorsal part of the inner wall. 

In this irregular collection of cells the following centres have 
been described : (1) The nucleus, through which the corpus callosum 
passes (Koppen); (2) the lower internal or median cell-area 


THE. CEREBRAL HEMISPHERES. 159 


(Osborne), situated above the foregoing nucleus in the posterior and 
middle portions of the hemispheres ; (3) the upper internal cell-area 
(Osborne) is the area of large cells in the dorsal part of the inner 
wall; (4) the Corpus striatum (Osborne) is a mass of cells between 
the corpus callosum and the commissura anterior; Koppen doubts 
the correctness of Osborne’s opinion, and suggests that a group of 
cells found in the wall of the third ventricle in front of ‘ Meynert’s 
band’ may perhaps be a corpus striatum. 


Fig. 100. 


From a transverse section through one of the cerebral hemispheres ; from Stieda, 
(Magnified 360 times.) 


a Epithelium of lateral ventricle. 
b Nerve cells. 
ce Connective-tissue processes from the Pia mater. 


A bundle of longitudinal medullated nerve-fibres, the ‘round 
bundle,’ is found on either side of the median line (Fig. 107 4d), 
and near the lower border in the posterior portion of this region ; 
these fibres can be traced from the posterior section of the thala- 
mencephalon ; they diminish in number as they course through the 
base of the cerebral hemispheres, and are ultimately lost in the 
lower anterior part of the outer walls. A second strand of lon- 
gitudinal fibres is the continuation of that of the Tber-cinereum 
above described, which can be followed to the outer wall of the 
posterior part of the ventricles, and to the anterior commissure. 

The commissures are: (1) The corpus callosum, a large bundle of 
transverse fibres, seen best in a transverse section, at the point of 
junction between the /amina terminalis and the cerebral hemi- 
spheres, forming an arch over the roof of the anterior prolongation 
of the third ventricle. The fibres course to the inner and anterior 
parts of the hemispheres, and are situated chiefly behind the fo- 
ramen Monroi. To this commissure must be added those fibres 
which unite the two olfactory lobes, and possibly the fibres (Com- 
missura posterior) found in the roof of the third ventricle (Küppen). 
(2) The Commissura anterior (Stieda), a smaller set, found immedi- 


160 THE NERVOUS SYSTEM. 


ately under the floor of the common ventricle, forming in their 
course outwards a curve, with the concavity directed downwards. 
This commissure connects the ‘round bundles’ of opposite sides, 
and those fibres coursing with the ‘round bundles’ to the olfactory 
lobes constitute the pars olfactoria of the commissura anterior. To 
this commissure must also be added some fibres found on the ventral 
surface of the commissura anterior and connecting the two strands 
of the Tuber-cinereum ; an unusually coarse strand of these fibres 
can be traced to the inner wall of the ventricle, and is termed the 
pars olfactoria interna by Osborne. 

The general structure of the olfactory lobes resembles that of 
the Wyck the olfactory nerves arise each by two roots, an 
outer and inner. The outer root arises from the outer wall near the 
groove between the corresponding hemisphere and olfactory lobe ; 
the inner or anterior root arises from the anterior surface of the 
olfactory lobe. Both roots have a peculiar method of origin from 
the extremely fine fibrillar network of the matrix (Nerve-fibre- 
conglomerate, Küppen), in which are rounded dark bodies known 
as ‘ glomeruli ;? in the ‘ glomeruli’ dark points and nuclei are seen, 
between larger and smaller bands of nerve-fibres. K6ppen holds 
that all the sensory nerves of the brain arise in a similar manner. 

A decussation takes place between the two inner roots of the 
olfactory nerves; possibly the external roots are connected by 
means of the commissura anterior. 

Very little pigment exists in the cerebral hemispheres or olfac- 
tory lobes, the greater portion is found in the upper part of the 
inner walls of the cerebral hemispheres. 

The epithelium of the ventricles of the brain, like that of the 
central canal of the spinal cord, consists of conical cells with 
their bases directed towards the cavity, and their apices directed 
peripherally and prolonged into distinct processes (Figs. 104, 109 a). 
In such situations, as the choroid plexuses, where nervous tissue is 
absent and the cavity is completed by pea mater alone, the epithelial 
cells are flattened. Everywhere else it is ciliated! and possesses dis- 
tinct round nuclei which are as broad as the cells themselves. The 
epithelium is somewhat irregularly and sparsely pigmented ; the 
ventral parts of the central canal of the spinal cord, of the fourth 
ventricle, and of the Sylvian aqueduct are always more pigmented 
than the dorsal parts. 


1 Schmidt (/. c.) states that the epithelium of the central canal of the spinal cord is 
not ciliated. 


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162 THE NERVOUS SYSTEM. 


(C. THE Coverines or THE BRAIN AND Spinat Corp. 


1. The Pia mater closely invests the whole of the brain and 
spinal cord ; it may, in fact, be regarded as the flattened, outermost 
layer of the connective-tissue material which supports the nervous 
elements ; fine processes (Fig. 109 c) pass radially from its inner 
surface to join the general connective-tissue matrix or neuroglia. 
It is usually pigmented, those portions covering the optic lobes 
and spinal cord being especially deeply pigmented: on the cerebral 
hemispheres it contains very little pigment; at times, indeed, 
in À. temporaria, pigment ts absent from this part. 

The pia mater is continued on to the choroid plexuses and pituitary 
body, and on to the pineal body by means of the pedicle; the 
membrane is very vascular, and forms, especially for the cerebral 
hemispheres and the olfactory lobes, a very important source for 
the direct supply of blood-vessels. 


2. The Dura mater, or liming membrane of the cranial cavity and 
vertebral canal, is a connective-tissue membrane containing’ many 
very much branched, pigmented cells. This membrane is not so 
deeply pigmented as the pia mater, except in that portion covering 
the cerebral hemispheres and the olfactory lobes, which is much 
darker than the corresponding portion of the pia mater. 

8. The arachnoid membrane is the layer of endothelial cells 
covering the inner surface of the dura mater: by means of the 
blood-vessels and nerves, ete., it is continued on to the pia mater 
of the spinal cord and brain, which it in like manner closely invests. 
Masses of calcareous crystals are found between the epineurium 
and the arachnoid (Wiedersheim) on each spinal nerve at its exit 
from the intervertebral foramen, also on the trigeminal nerves in 
the cranium. Additional smaller and more irregular masses are 
found on the dorsal part of the dura mater of the spinal cord. 


D. THE VEssELs or THE BRAIN AND SpinaL Corp. (Fig. 110.) 


The arteries of these organs are derived from the internal carotids 
and the arteriae vertebrales. As soon as the internal carotid arteries 
reach the cranial cavity each divides into two branches, an ante- 
rior (Ramus anterior, Schbbl!) and a posterior (Ramus posterior, 
Schôbl) ; the anterior branches course forwards on the lower part of 

1 These names are those adopted by Schôübl for corresponding vessels in the newt, 


the translator has accepted them as being suitable, with slight modification, to the 
vessels of the frog. 


VESSELS OF THE BRAIN AND CORD. 163 


the surface of the brain as far as the anterior portion of the tha- 
lamencephalon, where they again divide; one division, arteria 
loli hemisphaerici inferior externa (Schobl), continues forwards along 
the outer surface of the cerebral hemisphere and of the olfactory 
lobe as far as the olfactory bulb, where it may still be distinctly 
seen ; it gives off branches to the adjacent parts in its course for- 
wards. The vessels of the two sides communicate with each other 
by means of delicate transverse vessels (Arteriae communicantes ante- 
riores). The second division, arteria lobi hemisphaerici superior in- 
terra (Schobl), of the ramus anterior courses on the thalamencephalon 
to the dorsal surface, gives a large branch to the choroid plexus of 
the fourth ventricle, and runs forwards in the dorsal longitudinal 
fissure ; it supplies vessels to all the neighbouring parts. 

The rami posteriores converge as they course backwards, and ulti- 
mately unite to form an arteria basilaris, which is continued in the 
median line of the under surface of the spinal cord as the arteria 
spinalis anterior. The ramus posterior gives off, in its course, many 
small vessels to the neighbouring parts, and two larger vessels on 
either side, one of which, the arteria obi optici (Sehôbl), is distributed 
to the optic lobes, while the other passes to the pituitary body. 

The branches of these vessels form a network in the pia mater, 
from which the nervous tissue is supplied ; they also send numerous 
branches directly into the brain and cord, and these have a similar ar- 
rangement for all parts of the brain with the exception of the cerebral 
hemispheres and olfactory lobes ; more or less vertical branches arise 
from the posterior parts of the upper borders of the rum anteriores, 
from the whole of the rami posteriores, and from the arteria basi- 
laris ; these course upwards from their place of origin into the corre- 
sponding part of the brain, give off a few branches in the white 
matter, and then branch freely, and at somewhat sharp angles, 
in the grey matter. In the pars commissuralis a large branch may 
be traced from the ramus posterior on either side upwards into the 
cerebellum almost to its upper border. The vessels of the cerebral 
hemispheres and olfactory lobes seem to possess no other definite 
arrangement than that described above. The grey matter seems, 
on the whole, to be more vascular than the white; the vessels of 
the latter are chiefly arranged radially to the surface, and run in 
courses which are more or less straight; the vessels of the grey 
matter are more irregular and smuous. 

The Arteria spinalis anterior courses along the whole length of 
the spinal cord, giving off lateral branches and communicating with 

M 2 


164 THE NERVOUS SYSTEM. 


rami spinales (branches of the Arteria vertebralis). These branches 
form a plexus in the pia mater, from which vessels pass at irregular 
points into the cord ; one set of small vessels, described by Reissner, 
pass in a straight course from the superior longitudinal sinus 
towards the substantia reticularis, where they divide. Other branches 
pass directly from the arteria spinalis anterior, through the ventral 
longitudinal fissure, and there divide; the twigs as a rule avoiding 
the septum medium and passing in greater part towards the ventral 
Fig. 110. horns. The vessels in the white matter are 
for the most part radial and straight, while 
in the more vascular grey matter they are 
irregular and more sinuous in their course. 
The choroid plexus of the third ventricle 
(Plexus choroileus ventriculi tertii, Reissner) 
lies, as already described, on the roof of the 
emt third ventricle ; it is somewhat triangular in 
op b form (Plexus venosus triangularis, Schobl), and 
é is evidently a prolongation of the pia mater, 
with an increased supply of vessels. It re- 
ceives, at its anterior angle, veins from the 
cerebral hemispheres and the adjacent parts. 
The under surface is covered with a layer of 
ciliated pavement epithelium. At the pos- 
terior angles of the plexus the veins commu- 
nicate on either side (Fig. 110) with the 
Pe actA Seu eat Reed anterior lateral prolongation of the vena 
spinalis posterior, the Ve- spinalis superior, and with the internal jugular 


» spinale. eriores, and = 
the origin of the Vena Vein. The small body usually named the 


mo 


jugularis interna, pineal body, and placed on the roof of the 
H Hemispheres. : : : ° - : 
ee ne. ventricle, is only a small thickened portion of 


op Optic lobes. the plexus, and consists of a group of convo- 
mo Medulla oblongata. 4 = 


spp Venaspinalis posterior. luted blood-vessels. This plexus sends a con- 
siderable bunch of vessels into the upper part of the third ven- 
tricle. The choroid plexus of the fourth ventricle (Plexus choroideus 
ventrieuli quarti, Reissner) is a triangular membrane, slightly at- 
tached to the borders of the fourth ventricle. Its upper surface 
is flat and bounded at either side by a large vein, the vena 
spinalis superior; anteriorly it is bounded by the cerele//um. The 
under surface is not flat; in the middle line is a slight furrow 
corresponding to the position of a median vessel, which may, when 
injected, be seen from the dorsal surface; from it a number of 


~ 


VESSELS OF THE BRAIN AND CORD. 165 


short vessels pass outwards and slightly backwards to the outer 
border. The connective-tissue between these vessels is pushed down 
into the cavity ; in this manner one obtains a double row of flattened 
villous-looking bodies, which frequently have their tips pigmented. 
The under surface of the plexus is clothed with flattened, ciliated 
epithelium. 

On either side of the pituitary body is another small venous 
plexus (Plexus lateralis, Schobl); it communicates above with the 
posterior angle of the choroid plexus of the third ventricle; exter- 
nally, with the internal jugular vein ; and internally with its fellow 
of the opposite side by more or less irregular transverse vessels, 
which, together with a median vein from the fissure between 
the cerebral hemispheres, form an irregular cireulus venosus around 
the pituitary body. These plexuses receive blood from the lower 
part of the cerebral hemispheres, the thalamencephalon, the optic 
lobes, and from the pituitary body. The veins of the spinal cord 
open into the dorsal, vena spinalis posterior (Fig. 110 spp), which 
bifurcates at the posterior angle of the fourth ventricle, one division 
passing to either side and forming, as already described, the outer 
border of the choroid plexus ; anteriorly it opens into the internal 
jugular vein (Fig. 110 72). 

The blood-vessels, both arteries and veins, are irregularly pig- 
mented, both on the surface and in the interior of the central 
nervous system; those of the cerebral hemispheres and olfactory 
lobes have very little or no pigment. 


m 


166 


DESCRIPTION 


OF THE FIGURES ON PLATE I. 


Fig. 111. Dorsal view of the orbit, etc. ; deep dissection. 


Course of the palatine nerve, 

Fibrous plate. 

M. depressor maxillae. 

Terminal branches of the ophthalmic nerve. 

Facial with R. anterior of the glossopharyngeal. 

Terminal twigs of the ophthalmic nerve. 

Muscular twigs of the Ram. maxillaris. 

M. intertransversar. capitis superior. 

Twigs of upper eyelid. 

Terminal twigs of the Ram. maxillaris. 

M. levator anguli scapulae. 

M. pterygoideus. 

M. sterno-cleido-mastoideus. 

Sympathetic nerve, 

M. temporalis, 

Nasal branch. 

Union of facial nerve with Ram. 
the glossopharyngeal nerve. 

Olfactory nerve. 


Fig. 112. 
External branch of the ophthalmic nerve. 
Internal branch of the ophthalmic nerve. 
Terminal twigs of the ophthalmic nerve. 
Optic nerve. 
Motor oculi nerve. 
Trochlear nerve. 


anterior of 


IT Optic nerve. 
IIT Motor oculi nerve. 
IV Trochlear nerve. 
Vb R. palatinus 
of the trigeminal 
nerve. 


Ve R. maxillo-mandibularis 

Ve’ R. maxillaris 

Vd _ R. mandibularis 
7e(V1II) Facial nerve. 

Vg  Gasserian ganglion. 

Trigeminus, 

VS Sympathetic nerve. 

VI Abducens nerve. 

Facial nerve, 

VIII Auditory nerve. 

Xr Ram. anterior of the glossopharyngeal, 

X2  Glossopharyngeal nerve, 

X3 + Pneumogastric nerve. 

XG Ganglion nervi vagi. 

XI  Accessory nerve. 


Dorsal view of the orbit, etc. ; superficial dissection. 


Va Ophthalmic nerve. 

Ve — R, maxillo-mandibularis. 

Ve’ R. maxillaris of the trigeminal nerve. 

Vd _ R. mandibularis of the trigeminal nerve. 
VI  Abducens nerve. 


Fi g. 113. View of roof of mouth ; mucous membrane, etc., removed. 


Branch of the Ram. palatinus to the Harderian 
gland. 

Branch of the Ram. palatinus to the inter- 
maxillary gland. 

Inosculating-branch of the Ram. palatinus. 

Internal naris. 

Cutaneous branch of the Ram. palatinus, 

Fibrous plate. 

Ramus mandibularis of the facial nerve, 

Intermaxillary gland. 

Harderian gland. 

Eyeball. 

M. masseter, 


Ms.ob.i. M. obliquus inferior. 


OK 
r 


Upper jaw. 
M. retractor bulbi. 
Fig. 1141. 

Cardiac nerve. 

Union of facial and Ram. anterior of the 
glossopharyngeal nerve. 

Ram. hyoideus of the glossopharyngeal nerve. 

M. levator angi scapulae. 

M. longissimus dorsi. 

M. masseter. 

Ram. mandibularis of the glossopharyngeal 
nerve, 


Hypoglossal nerve. 


Brachial nerve, 

Anterior cornu of the hyoid bone. 
M. obliquus internus, 

M. petrohyoideus I. 

M. petrohyoideus IT. 

M. petrohyoideus III, 

M. petrohyoideus IV, 


VI’ Ciliary nerves. 

ri M. rectus internus. 

ri’ M. rectus inferior, 

se M. sterno-cleido-mastoideus, 

uk Mandible. 

+ Terminal branch of Ram. palatinus. 

* Union of facial nerve with Ram. anterior of 


the glossopharyngeal. 

IIT Motor oculi nerve. 

Vb Ramus palatinus of trigeminal nerve. 

Ve Ramus maxillo-mandibularis of the trigeminal 
nerve. 

Ve’ Ramus maxillaris of the trigeminal nerve. 

Vd __ R. mandibularis, 

Ve (VII) Facial nerve. 

X Pneumogastric nerve. 

X1  Glossopharyngeal nerve. 


Lateral dissection of head, etc., to show the cranial nerves, etc. 


pp  Pharyngeal branches of the pneumogastrie 
F nerve. 

tt! M. temporalis. 

us Muscular twigs of the Ram. mandibularis of 

the trigeminal nerve. 

Z Tongue. 

Va Terminal twigs of the ophthalmic nerve. 

Ve Ram. maxillaris of the trigeminal nerve. 

Vd Ram. mandibularis of the trigeminal nerve, 

Ve (VII) Facial nerve. 

X1 Ram. anterior of the glossopharyngeal nerve. 

X2  Glossopharyngeal nerve. 

X3 + Pneumogastric nerve. 

X37 Ram. gastrici of the pneumogastric nerve, 

X3 Ram. laryngeus. 

X3p Ram. pulmonales of the pneumogastric nerve, 

XI Accessory nerve of the pneumogastric nerve. 


Fig. 115. Dissection of the floor of the mouth. 


M. depressor maxillae. 
United facial nerve and Ram. anterior of the 
glossopharyngeal nerve, 


} M, geniohyoideus. 


Ram. hyoideus of the glossopharyngeal nerve. 

Heart. 

Lung. 

Ram. mandibularis of the glossopharyngeal 
nerve, 

Hypoglossal nerve, 

Brachial nerve. 

Anterior cornu of the hyoid bone. 

Momohyoideus. 

M. petrohyoideus I, 


ph2 M. petrohyoideus IT, 
ph3  M.petrohyoideus ITT. 
ph4 M. petrohyoideus IV. 


se M. sterno-cleido-mastoideus, 

sh M. sterno-hyoideus. 

sm. M. mylohyoideus (submaxillaris). 

M. submentalis. 

Thyroid. 

uk Mandible. 

us Muscular twigs of the Ram, mandibularis. 
2  Glossopharyngeal nerve. 

X3  Pneumogastric nerve. 


X3¢ «Rami cardiaci of pneumogastric nerve. 
X3/ Ram. laryngeus of the pneumogastric nerve. 
X3p Ram. pulmonalis of the pneumogastric nerve. 


1 The branches of the vagus which are represented in this nee as crossing the petrohyoid muscles ought to 
be underneath them.—Trans. 


THE CRANIAL NERVES. 167 


Il. THE PERIPHERAL NERVOUS SYSTEM. 


EK. Tue CRANIAL NERVEs. 


(To facilitate reference the original arrangement of this part 
has been altered.) 

[There are ten pairs of cranial nerves in the frog, which are 
numbered in order from before backwards. The mode of origin of 
these nerves, and their deeper relations with the respective parts of 
the brain to which they belong, have already been described. | 


1. The olfactory nerve (JV. o/factorius), [(Figs. 97, 98, 102, 103, 
111 /) runs a very short course only a few lines in length, and 
escapes from the cranium by an opening in the cartilage of the 
sphenethmoid into the nasal cavity, where it divides into two branches, 
each of which breaks up into a brush of filaments, to be distributed 
in the olfactory mucous membrane. The nerve contains no white 
fibres]. (See organ of smell, p. 385.) 


2. The optic nerve (J. opticus), (Figs. 97, 102, 103, 111 JL) 
[arises, as already described, by the optic tract, and joins with its 
fellow at the optic chiasma or commissure, where part of the fibres 
pass over to the opposite side (according to Michel all the fibres 
cross). Each optic nerve then courses outwards, piercing the car- 
tilage of the cranium and so reaching the eyeball]. (See organ 
_ of sight, p. 408.) 


3. The motor oculi (V. oculomotorius, Oculo-motor, Motor com- 
munis), (Figs. 102, 111, 112, 113 211). From its origin it courses 
outwards and forwards, perforating with a slight obliquity the carti- 
laginous wall of the cranium, just in front of the Gasserian gan- 
elon (Fig. 116 Z//); on reaching the orbit it divides into two 
branches, between the Levator bulbi and the Rectus internus and in- 
ferior. One branch, Ramus superior, runs over and parallel to the 
Ramus ophthalmicus Trig. and enters the under surface of the 
Rectus superior ; the second, lower branch, Ramus inferior, supplies 
filaments to the Rectus internus and inferior and to the Obliquus in- 
ferior. Apparently it exchanges fibres with the ophthalmic division 
of the trigeminal nerve. 

[That portion of the motor-oculi between its branch to the 
Rectus superior and to that to the Rectus internus contains a 
number of nerve cells; according to Schwalbe (7. e., p: 235 and 
Pt. XII, Fig. 4) these cells are arranged in four groups or ganglia ; 


168 THE NERVOUS SYSTEM. 


the second group forms a very slight prominence, and is covered by 
a very fine layer of nerve fibres, it also gives off some extremely fine 
nerves to the eyeball; this is perhaps a ciliary ganglion (Ganglion 
ciliare, Schwalbe). Beard, however, names it ‘mesocephalic gan- 
glion” The other three groups are simply clusters of cells between 
the fibres of the nerve. | 


4. The pathetic or trochlear nerve (N. {rochlearis, patheticus), 
(Figs. 102, 103, and 112 J/’). From its origin it courses forwards 
with and then crosses the motor-oculi ; it perforates very obliquely 
the cartilaginous lateral wall of the cranium, in front of the 
motor oculi but above and very slightly behind the optic foramen 
(Fig. 116); it runs parallel to and m company with the Ramus 
opthalmicus trigemini, and appears to exchange a few fibres with it, 
which, however, according to de Watteville, Stannius, Cuvier, and 
Wyman, is not really the case. In this course it lies first to the inner, 
then to the outer side of the ophthalmic, over which it passes to 
supply the Rectus superior. {The pathetic and ophthalmic nerves 
are sometimes enclosed in a common sheath (de Watteville). | 


5. The trigeminal nerve (N. frigeminus), (Figs. 97, 102, 103, 
111, 112, 113, and 114 V’) is the largest of the cranial nerves in 
the frog ; from its origin it runs outwards and forwards to the skull 
wall, and just before reaching this enters the large Gasserian 
ganglion. It then passes through the cranial wall immediately in 
front of the auditory capsule, and divides at once into two main 
branches (Fig. 111 Vg, etc.), the Ramus ophthalmicus and the Ramus 
maxillo-mandibularis. 

The Gasserian ganglion is a large, yellow, oval ganglion placed 
in a depression in the outer wall of the cranium ; it is covered by a 
‘periganglionic gland,’ which is similar in structure to that of 
a spinal ‘periganglionic’ gland (see p. 180), the fibrous capsule 
bemg stronger. This ganglion receives three other nerves besides 
the trigeminal, viz. the sixth and seventh nerves, and branches of 
the sympathetic. 

According to de Watteville, these nerves are arranged on the 
lower surface of the ganglion, so that the sympathetic is below, 
the sixth above it, then the seventh, while the fifth is uppermost ; 
the sympathetic splits into several bundles which join the various 
branches of the ganglion ; the sixth divides into two bundles, one of 
which usually joins the ophthalmic, while the other makes its exit 
independently; the seventh splits into two bundles, one of which 


THE CRANIAL NERVES. 169 


leaves the ganglion as the hyomandibular branch, the other gives 
some fibres to the palatine branch of the trigeminal nerve, and is 
then continued as the palatine branch of the facial. ] 


a. The Ramus ophthalmicus (Ramus nasalis, Fischer ; Ophthalmic 
or Orbital Branch, Wyman ; Orbito-nasal or Ophthalmic Nerve, 
de Watteville), (Figs. 111 and 112 Va). After leaving the Gasse- 
rian ganglion the nerve is directed forwards parallel to the side of 
the cranium, between this and the eyeball. It lies beneath the 
Rectus superior, but above all the other muscles of the eyeball and 
the optic nerve. At the anterior end of the orbit it divides into 
two branches (e and f) which pass through apertures (Foramen pro 
ramo nasali) in the cartilage of the sphenethmoid, to reach the nasal 
cavity, where they lie between the cartilage and mucous membrane. 
In this position the nerves supply branches to the mucous membrane 
and then pierce the skull to appear on the surface (Figs. 111, 
112 9,9,9, 114 Va), the skin of which they supply. The branches 
mosculate with each other and communicate with the anterior twigs 
of the Ramus maxillaris (Fig. 114 Ve) and with those of the Ramus 
palatinus (Fig. 113 V6). 

In its course through the orbit the Ramus ophthalmicus gives 
off : — 

(1) Near the Gasserian ganglion one, two, or three small branches, 
which communicate with the trochlear nerve, and may then be 
traced to the sclerotic of the eyeball; some of the twigs enter near 
the optic nerve, others nearer the cornea. They are regarded as 
Ciliary nerves (Nervi ciliares). 

(2) A large branch, the palatine nerve (Ramus palatinus), 
(Figs. 111 and 113 V4,4). This nerve, after receiving the palatine 
branch of the facial, descends on the inner border of the Levator 
bulbi to the mucous membrane of the mouth, to which it gives 
numerous filaments ; it then runs parallel and near to the median 
line, lying on the base of the skull; and near the front of the 
orbit it divides into three branches. The smallest (a) supplies 
the Harderian gland (HJ); the second (/) continues in the course 
of the original nerve, pierces the vomer, and divides, giving 
filaments to the mucous membrane in its whole course, while 
the terminal twigs supply the intermaxillary gland (G/) and the 
surrounding structures. One of these (+) ascends on the anterior 
border of the sphenethmoid to the intermaxillary (internasal, 
Born) space to supply the numerous glands and to inosculate by 
one or two twigs with the nasal branch (/7) of the trigeminal. 


170 THE NERVOUS SYSTEM. 


The third branch of the palatine nerve (c) curves directly out- 
wards, just behind the palatine bone, to the inner surface of the 
maxillary bone; it then courses backwards, pierces the fibrous 
plate (db) between the eyeball and the pterygoid bone, and ulti- 
mately unites with superior maxillary division of the trigeminal 
nerve (Vc’). Just before piercing the fibrous plate it gives off a 
tolerably large nerve (4) to the mucous membrane, and in its whole 
course it gives off twigs to the mucous membrane and surrounding 
structures ; many of these twigs inosculate with other terminal 
twigs of the trigeminal. 

[This nerve ie been minutely described by Stirling and Mac- 
donald ; these observers find that the branches form a very fine and 
close ee in the mucous membrane, etc. ; fibres were traced to 
blood-vessels, glands, ete., and ganglion cells were found scattered 
along the nerves. The fibres are both medullated and non-medul- 
lated, and many of the cells are described as ‘spiral cells’ (see page 
201), such as those described by Arnold in the sympathetic system 
of the frog. | 


b. The Ramus maxillo-mandibularis (Ramus mawillaris, Ecker and 
Hoffmann ; Supra-maxillary, Humphry; Upper Maxillary Branch, 
Wyman), (Figs. 111, 112, and 113 Je). This nerve is the largest 
division of the Hans it runs directly outwards behind “the 
eyeball, in front of 1 tee y capsule, and between the temporal 
and pterygoid muscles. After a very short course it divides into the 
maxillary and mandibular nerves. The nerve gives off before its 
division a few fine filaments (7,7) to the hinder half of the upper 
eyelid and to the surrounding skin, also a branch (4) [not correctly 
drawn in Fig. 111] which divides to supply twigs to the temporal 
and pterygoid muscles. 


(1) The Ramus maxillaris (Ramus supramaxillaris, Ecker ; Ramus 
maxillaris superior, Hoffmann ; Upper Maxillary Branch, Wyman ; 
Supramaxillary, Humphry and de Watteville), (Figs. 111, 112, 
113, and 114 Vc) runs outwards and then forwards, between the 
eyeball and the outer wall of the orbit, to the margin of the upper 
jaw (K); a large portion terminates in a number of small branches 
for the supply of the skin of the lower eyelid, the upper lip, and of 
the parts between the tympanic membrane and the external nares. 
Some of these twigs inosculate with twigs of the palatine and 
ophthalmic nerves. The second portion of the nerve unites with 
the palatine nerve, as already described. 


THE CRANIAL NERVES. oy | 


(2) The Ramus mandibularis (Ramus maxillaris inferior, Hoft- 
mann; Mandibular or Lower Jaw Branch, Wyman; Inframaxillary, 
Humphry and de Watteville), (Migs. 111, 112, 113, 114, and 115 
Vd, us). As far as the outer margin of the eyeball, this nerve 
runs parallel to and behind the Ramus maxillaris, in which course it 
supplies branches to the temporal and pterygoid muscles ; it then 
curves backwards, outwards, and downwards to the under surface 
of the squamosal bone, where it supplies a twig to the Depressor 
maxillae, and then perforates the Masseler : in this manner it 
reaches the outer surface of the mandible, just behind the insertion 
of the temporal muscle ; it then courses forwards, under the skin, to 
the Symphysis menti. In this course the nerve gives off numerous 
branches to the skin and surrounding parts, it also supplies the 
mylo-hyoid and submental muscles; one branch (Figs. 114 and 
115 ws) is larger than the rest, and supplies the under surface of 
the floor of the mouth and lower lip. 


6. The abducens nerve (Nervus abducens, Ecker and Hoffmann ; 
included in the trigeminal, Wyman), (Figs. 111 and 112 V1). This 
very slender nerve courses along the inner wall of the cranium from 
its origin to the Gasserian ganglion (g.v.) which it joins, and leaves 
this in contact with the ophthalmic division of the trigeminal 
nerve: the nerve then bifureates in the orbit; the outer branch 
supplies the Rectus externus, the inner inosculates with small twigs 
of the ophthalmic division of the trigeminal, and then gives off 
a number of small ciliary nerves, already described, and one special 
branch to the Retractor bulbi. 


7. The facial nerve (NV. facialis, Ecker and Hoffmann ; Facia/is 
(Portio dura), Wyman; Facial or Jugular Nerve, Stannius), (Figs. 
111, 113, and 114 Ve VII) arises immediately behind the trige- 
minal, and runs forwards, first in company with the auditory 
nerve, then alone, to the Gasserian ganglion (q.v.), with which it 
unites ; 1t again appears at the posterior angle of the ganglion, 
and escapes from the cranium in company with, and immediately 
behind, the Ramus mandibularis of the trigeminal, and divides at 
once into two branches. 


a. The Ramus palatinus at once unites with the palatine 
branch of the ophthalmic division of the trigeminal nerve. 
Wiedersheim doubts this arrangement, and holds that the two 
portions arise in common from the Gasserian ganglion; neither 
has Wyman (Rana pipiens) described this branch of the facial. 


112 THE NERVOUS SYSTEM. 


[De Watteville states that the Ramus palatinus and the palatine 
branch of the ophthalmic nerve are separated by the carotid artery. 
In urodeles the two nerves are distinct. | 


b. The Ramus hyomandibularis (Ramus jugularis, Hoffmann ; 
Facial Nerve, Wyman), (Figs. 113 and 114, Ve VII). The nerve 
is directed outwards and backwards so as to pass around the 
bony wall of the auditory capsule, it then crosses over the mner end 
of the columella, with which it is in close contact, and is then 
joined, under cover of the s/erno-cleido-mastoideus (sc), by a branch 
(Ramus communicans) of the glossopharyngeal (see Fig. 111 *). The 
single trunk (/’) so formed is directed downwards in the posterior 
wall of the Eustachian tube to just above the angle of the mandible, 
where it divides into three branches, or sometimes into two, in 
which case a third nerve is supplied by one of the others, usually 
by the Ramus hyoideus. 


(1) The Ramus mandibularis (Ramus mentalis, Hoffmann ; Third 
Trunk of the Facial, Wyman), (Figs. 114 mt and 115 m’) passes inside 
the angle of the jaw and courses forwards, between the skin and 
mylo-hyoid muscle, parallel to the Ramus mandibularis of the 
trigeminal nerve, as far as the symphysis. It supplies small twigs 
to the neighbouring parts of the mucous membrane of the mouth. 


(2) The Ramus hyoideus (Ramus jugularis, Hoffmann ; Second 
Trunk of the Facial, Wyman), (Figs. 114,115 4) is the largest division 
of the facial ; it courses forwards subcutaneously over the de/toideus 
and the hinder fibres of the my/o-hyoideus to the anterior cornu 
of the hyoid bone, supplying its muscles and the skin of the throat 
and sternal region. 

(3) The Ramus auricularis (First Trunk of the Facial, Wyman) ; 
is a small branch, directed outwards ; it supplies a branch to the 
walls of the tympanic cavity, and is finally distributed in the 
skin under the tympanic membrane and behind the angle of the 
mouth. 


8. The auditory nerve (iV. acuslicus, Ecker, Hoffmann ; Audi- 
tory Nerve, Wyman). This nerve has a very short course in the 
cranium ; it reaches the auditory organ by a foramen (Fig. 116 
VIII) in the auditory capsule, and 1s then distributed in the ear, 
with which it will be described. 


9. The glossopharyngeal nerve (NW. glossopharyngeus, Ecker ; 
Ramus glosso-pharyngeus, Hoffmann ; Glossopharyngeal, Wyman ; 


THE CRANIAL NERVES. 173 


Glossopharyngeal of the Vagus, Müller), (Figs. 102 and 103 À, 111, 
113, 114, and 115 À?) arises in common with the pneumogastric 
nerve, and quits the skull with it through an opening (Canalis nervi 
vagi) immediately behind the auditory capsule, and at once divides 
into two branches ; both of which lie under the M. intertrans- 
versarii capitis and are covered by the Depressor mandibulae. 


a. The Ramus anterior (Verbindungsast des Glossopharyngeus, 
Wiedersheim ; Aamus communicans, Hoffmann; Uniting Branch, 
Wyman; Laryngeal Branch of the Vagus, Volkmann ; Communi- 
cans ad facialem, de Watteville), (Figs. 111, 113, and 114 X1). This 
nerve curves downwards and forwards around the auditory capsule 
and beneath the Depressor mandibuli to jom the facial nerve, as 
already described. 


b. The Ramus posterior (N. glossopharyngeus, Wiedersheim ; 
Ramus lingualis, Hoffmann), (Figs. 111, 113, and 114 X?). This 
nerve runs downwards and forwards to the ventral surface of the 
pharynx, dips underneath the Petrohyoideus IV, to appear again, 
after a short interval, by piercing the Petrohyoideus IT or ITI, 
courses parallel to and behind the anterior cornu of the hyoid bone, 
and thus reaches the floor of the mouth. The nerve then runs 
forwards in a very sinuous course, close to the median line, and 
between the Gexiohyoideus and Iyoglossus ; in its course on the 
floor of the mouth it crosses the hypoglossal nerve. It supplies 
the petrohyoid muscles, and gives numerous small branches to the 
mucous membrane of the pharynx (Ramus pharyngeus, Hoffmann). 


10. The pneumogastric or vagus nerve (Vagus; Ramus intestinalis 
nervi vagi, Fischer, Hoffmann; Vagal Trunk, Wyman; Vaso- 
sympathetic, Gaskell), (Figs. 111, 113, 114, and 115 X°). This 
nerve arises In common with the glossopharyngeal ; the two nerves 
leave the skull together by an opening in the exoccipital bone 
(Canalis nervi vagi) ; immediately outside the skull they acquire a 
ganglionic enlargement (Ganglion condyloideum, Ganglion nervi vagi), 
(Fig. 111 XG); in this course the glossopharyngeal lies in front of 
the pneumogastric, which it then leaves. The pneumogastric lies 
first upon the M. /evator anguli scapulae, then running backwards 
and downwards along the hinder border of the Petrohyoideus IT 
it comes to the side of the pharynx ; it is covered by the trapezius, 
and passes between the hypoglossal nerve and the Aorta ascendens : 
arriving at the Arteria pulmonalis, it gives off its terminal branches, 


174 THE NERVOUS SYSTEM. 


[Gaskell has proved that this nerve contains both sympathetic and 

vagal elements, and that it is therefore really a vago-sympathetic. | 

The branches 

Fig. 116. and communica- 

tions of the pneu- 

mogastric nerve 
are :— 

a. Communica- 
tions between the 
eanglion of the 
pneumogastric and 
the sympathetic 
system (Fig. 111 
Sp), which again 


Right half of skull of Rana esculenta, seen from within. 


IT Optic nerve. 


III Motor oculi nerve. connect it with 
IV Trochlear nerve. - 
VN Root of the trigeminal nerve. the Gasserian gan- 
Vg  Gasserian ganglion. olf ae 
VS Sympathetic nerve. glion of the tri 
VI Abducens nerve. geminal nerve 
VIN Facial nerve. : = a 
VIIT Auditory nerve. (Fig. TITY 5, Va); 
{1-3 or j closs arynges rves. 1 
X Pneumogastric and glossopharyngeal nerve (s ee sympath etic 
system). 


b. [The Ramus cutaneus dorsalis (Fischer) is considered by Stan- 
nius and Fürbringer to be the homologue of the Ramus auricularis ; 
it passes outwards between the digastricus and temporalis to be 
distributed in the skin of the suprascapular region. This nerve 
is the persistent portion of the N. /ateralis nervi vagi of the 
tadpole. | 


ce. During its course over the petrohyoide: the vagus gives off a 
few twigs (Fig. 114 pp), which form a fine plexus to supply these 
muscles and the pharynx [also a twig to the trachea, according to 


Hoffmann |. 


d. The Ramus accessorius (Fürbringer, Hoffmann, Ecker), (Fig. 
114 X/) is usually a single small nerve which runs between the 
intertransversarii muscles and the trapezius: it supplies the under 
surface of the latter muscle. 


e. The Ramus scapularis (Hoffmann) is a very slender nerve arising 
near the Ramus accessorius ; it passes along the under surface of 
the trapezius to the inner surface of the éxferscapularis, which it 
supphes. 


THE SPINAL NERVES. 175 


f. The Ramus laryngeus (Recurrens vagi), (Figs. 114 and 115 
X3/) runs for some distance parallel to the pneumogastric, separated 
from it by the petrohyouleus IV; arriving at the hinder cornu of 
the hyoid bone the nerve loops round the Arteria pulmonalis, and 
divides into two branches for the supply of the larynx. 


g. The Rami gastrict (Fig. 114 X39) are usually two in number : 
they pierce the partial diaphragm formed by the anterior fibres of 
the MW. obliquus internus and terminate in the walls of the stomach. 


h. The Lam pulmonales (Figs. 114 and 115 X3p) also perforate 
the partial diaphragm, and then course along the pulmonary arteries 
to the lungs. 


i. The Ramus cardiacus (Figs. 114 and 115 X3c). This nerve 
is usually smaller on the right side than on the left; it passes 
along the dorsal surface of the pulmonary artery and Vena cava 
superior to the Sinus venosus ; in this course it gives off two or three 
twigs to the roots of the lungs: the two nerves communicate just 
before reaching the heart and pass on to the auricular septum, 
whence they are distributed to the heart. 


j. A slender Laryngeal nerve arises from the vagus alongside 
the Ramus cardiacus ; 1t courses along the hinder end of the greater 
cornu of the hyoid to the outer side of the pharynx, which it 
pierces to pass to the larynx. 


F. Tue Sprnat NERVES. 


I. General description. Ten pairs of nerves arise, as already 
described (p. 135), from the spinal cord; each nerve has two 
roots, a ventral or anterior, and a dorsal or posterior, which unite 
at their points of exit from the intervertebral foramen: just 
before, and for a short distance beyond this union, each dorsal 
root bears a ganglionic enlargement. 


1. The length and direction of the various Nerve-roots vary 
greatly; the roots of the anterior spinal nerves run a very short 
course, almost transversely outwards, from their points of origin to 
the intervertebral foramina: the roots of the middle and posterior. 
nerves, in consequence of the vertebral column being considerably 
longer than that part of the cord belonging to it, pass obliquely 
backwards to the foramina, the hinder nerves of the Cauda equina 
running for a considerable distance in the vertebral canal (Fig. 116). 
The relations of these roots are as follows :— : 


be 


176 THE NERVOUS SYSTEM. 


(1) The roots of the first nerve (NV. Aypoglossus) arise from the 
spinal cord at a point between the first and'second vertebrae ; they 
run transversely outwards to escape between the first and second 
vertebrae. The dorsal root is extremely slender. 


Tikes 7p 


(2) The roots of 
the second nerve (NV. 


The nervous system of Rana es- 
culenta, from the ventral sur- 
face. (From Icones physiolo- 
gicae by A. Ecker. Pl. XXIV, 


Fig. 1.) 
F Facial nerve. 
G Ganglion of pneumogas- 


tric nerve, 

He Cerebral hemisphere. 

Le Optic tract. 

Lop Optic lobe. 

M Boundary between me- 
dulla oblongata and spi- 
nal cord, 

Mx-10 Spinal nerves. 

MS Connection between fourth 
spinal nerve and sympa- 
thetic chain. 

N Nasal sac. 

Ni Sciatic nerve. 

No Crural nerve. 

Eyeball. 

S Trunk of sympathetic. 

Sr-10 Sympathetic ganglia. 

SM Rami communicantes of 
the same, 

Sp Continuation of sympa- 
thetic into head. 

eA Olfactory nerve. 

iI Optic nerve. 

III Motor oculi nerve, 

IV Trochlear nerve. 

V Trigeminal and facial 
nerves. 

Va Ramus ophthalmicus. 

Ve Ramus maxillaris. 

Vd Mandibular branch of 
trigeminal. 

Ve  Hyomandibular branch of 
facial. 

Vg  Gasserian ganglion, 

Vs Upper end of sympathetic 
trunk in connection with 
Gasserian ganglion. 

VI  Abducens nerve. 

VII Facial nerve. 

VIII Auditory nerve. 

D. Glossopharyngeal and 
pneumogastric nerves. 

Xx Ramus anterior of glosso- 
pharyngeal. 

X2 Ramus posterior of glosso- 
pharyngeal. 

V3, 4 Branches of pneumogas- 
tric, 


THE SPINAL NERVES. iy Hs 


brachialis) arise at the level of the second vertebra and leave the 
vertebral canal between the second and third vertebrae. 


(3) The roots of the third nerve arise from the cord between the 
second and third vertebrae, and pass out between the third and 
fourth vertebrae. 


(4) The fourth nerve arises by its two roots at the level of the 
fourth vertebra, and quits the vertebral canal between the fourth 
and fifth vertebrae. 


(5) The fifth nerve arises opposite the fourth vertebra, and passes 
outwards and slightly backwards to the foramen between the fifth 
and sixth vertebrae. 


(6) The roots of the sixth nerve are attached to the cord opposite 
the fourth vertebra, and leave the vertebral canal between the 
sixth and seventh vertebrae. 


(7) The seventh nerve arises from the cord at a point between 
the fourth and fifth vertebrae, and leaves the canal between the 
seventh and eighth vertebrae. 


(8) The eighth nerve quits the cord at a point opposite the arti- 
culation between the fifth and sixth vertebrae, then runs backwards 
to the eighth vertebra, and escapes between this and the ninth 
vertebra. 


(9) The ninth nerve arises at the level of the sixth vertebra, and 
passes out between the sacrum (ninth vertebra) and the urostyle. 


(10) The tenth nerve (NV. coccygeus) arises from the cord immedi- 
ately behind the ninth nerve and opposite the sixth vertebra, and 
courses alongside the terminal filament to pass out through a fora- 
men in the urostyle (canalis coccygeus). 


b. [The Spinal ganglia (Ganglia intervertebralia). 
At their exit from the intervertebral foramen the two roots of 
. each nerve unite and bear a ganglionic enlargement, which is in 
intimate connection with the dorsal root, but is merely in contact 
with the ventral root. The ganglia lie! in the large intervertebral 
depressions, upon the under surface of the Proc. obliqui, above and 
behind, being in relation with the bodies of the vertebrae internally, 
and the Musculi intertransversarii externally (Fig. 119); ventrally 
the ganglia are, more or less, covered by the ‘ periganglionic glands.’ 
The ganglia vary much in size ; that of the first spinal nerve is the 

1 The Gangl. coccygeum is in the urostyle. 

N 


178 THE 


NERVOUS SYSTEM. 


smallest. The ganglion is not attached to the dorsal root alone 
but is prolonged a short distance beyond the point of union of the 
two roots; this is best seen in the nerves of the lumbar plexus. 


Fig. 118 


Ventral view of the brain and spinal cord, to show the 
points of exit of the spinal nerves. 


Mi-10 Spinal nerves. 
VG Trigeminal ganglion, 


Wi-10 Vertebrae. 


XG Ganglion of vagus. 


Each ganglion is a yel- 
lowish-white rounded 
or oval body, with an 
outer thick (sometimes 
‘15 mm. thick) sheath 
of connective - tissue, 
connected by the epi- 
neurium of the nerve 
roots with the Dura 
mater. This sheath is 
composed of bundles of 
parallel, wavy, white, 
connective-tissue fibres, 
which enclose a large 
number of connective- 
tissue corpuscles, and 
here and there contains 
brown pigment. 

By means of longi- 
tudinal and transverse 
sections it may be seen 
that the ganglion sur- 
rounds the ventral root, 
but that it forms a 
thinner layer on that 
side, where the dorsal 
root joins the ventral ; 
although at this point 
the two roots and the 
ganglion are firmly uni- 
ted together, the thick 
fibrous sheath of the 
ganglion prevents any 
communication be- 
tween the nervous ele- 
ments of the ventral 
root and those of the 
ganglion. 


THE SPINAL NERVES. 179 


The sheath contains nerve-cells and 
fibres, and sends in a few fine processes to 
support these structures. The fibres of 
the posterior root enter and pass out of 
the ganglion without suffermg any 
changes, except that the nerve fibres are 
slightly separated by the presence of a 
few nerve-cells, and that a distinct in- 
crease in the number of nerve fibres takes 
place. The nerve-cells, of which the 
ganglion is chiefly composed, and upon 
the number of which its size directly de- 
pends, are arranged chiefly around the 
fibres of the dorsal root; such few as 
lie between the fibres are smaller than 
the rest and vary more in their relative 
numbers ; at times one or two isolated 
cells are found in the capsule or even in 
the adjomimg ‘periganglionic gland.” 
The cells near the capsule are somewhat 
smaller than the deeper cells ?. Hach of is of ine ie ein! 
these cells, which are usually pear-shaped, on the right side they are still 
possesses only one process ; the cell mem- oS a Cees ao ag aaa 
brane is thick, resistant, and possessed of 
an external nucleated, endothelial covering, the space around 
being probably a pericellular lymph-space ; it often contains one to 
three small fat-globules ; the protoplasm 
of these has, according to v. Lenhossék, 
a concentric fibrillation ; the nucleus is 
round, clear, and distinct, and relatively 
- larger the smaller the nerve-cell ; it is 
usually placed in the centre of the cell. 

In that portion of the cell towards the 
process is a portion brighter and less 
easily stained than the rest of the cell 
(Polarkernen, Courvoisier); this apparent- Schema of spinal ganglion. 
ly possesses one or two nuclei, and is SET 


Cc Ramus communicans, 


regarded as a cell by Lenhossék (Polar- @ Ganglion, 


Fig. 120. 


O Dorsal division. 
zellen); the process of each cell soon Pea ant 
acquires a medullated sheath, and after # Ventral division. 


* Larger cells of deeper layer 80 y to go p in diameter, sometimes one or two as 
large as o-1 mm. v. Lenhossék. 


N 2 


180 THE NERVOUS SYSTEM. 


a short course, o‘og mm. to 0°35 mm., divides usually about the 
third constriction (Lenhossék). These processes all pass peripherally, 
even those which appear at first to pass in the opposite direction 
curve round again ; it is chiefly due to these fibres that the spinal 
nerve is larger than its two roots. 

In addition to the above, smaller, irregular cells from 5 u to 7 p 
in length are found; Rawitz regards them as young cells, Len- 
hossék as cells capable of (entwicklungsfähige) developing imto 
nerve-cells. The ganglia contain only few blood-vessels. | 

The above description is founded, upon that of Lenhossék, and 
has been confirmed by the translator in every particular, except 
that only very indistinct and unsatisfactory indications of the con- 
centric fibrillation so clearly delineated by Lenhossék were obtained ; 
the structure of the Gasserian ganglion was found to correspond 
exactly with the description here given of the structure of the 
spinal ganglia. The nucleus was oftener at the side than at the 
centre of the cell. 


ce. The ‘ Periganglionic Glands’ (Periganglioniire Kalkdriisen, 
v. Lenhossék ; Kalksiickchen, Ecker, and others ; Crystal capsules, 
Wyman ; Calcareous Sacs or Masses, of other writers), (Fig. 119). 
These bodies are found on the ganglia of all the spinal nerves and 
on the Gasserian ganglion of the trigeminal nerve; they have recently 
been carefully investigated by v. Lenhossék. According to his 
description there are usually two to each ganglion, lying on its 
sides and ventral surface ; each consists of a connective-tissue cap- 
sule which sends in a few fine trabeculae to support a system of 
glandular tubes: these usually run parallel to the long axis of the 
gland, and are about 14 pu to 15 p in diameter; each tube is lined 
with a single layer of somewhat columnar epithelium, the cells of 
which have sharp, distinct outlines and oval nuclei. 

A membrana propria was not made out with certainty; the lumen ‘ 
of the tubes is wide and contains a milky fluid, which gives the 
whole structure its characteristic appearance; it has long been 
known (Blasius, 1681, mentions the fact, /7.¢., p. 291) that this fluid 
contains calcareous matter, which effervesces and dissolves in the 
presence of hydrochloric acid ; the crystals vary in form but are 
chiefly oval (Wyman). « 

These glands bear no definite proportion to the size of the 
nerves to which they are attached (Fig. 118); they already contain 
calcareous matter during the tadpole stage before the limbs are 
developed (Stannius, Wyman). No ducts have been traced to 


THE SPINAL NERVES. 181 


these glands. This description, founded upon that of Lenhossék, 
can be confirmed by the translator in every particular ; his sections, 
however, would lead him to believe that the glands are far more 
vascular than the description and the drawings of Lenhossék 
imply. | 


d. The Branches of the complete spinal nerves formed by the 
union of the dorsal and ventral roots with the ganglion (Fig. 120) 
are usually described as two, a dorsal and a ventral branch, which 
latter at once gives off a Ramus communicans to the sympathetic 
system; these two branches are given off almost immediately 
beyond the ganglion. 


Il. The Individual Nerves. 
A. The Dorsal Branches (Fig. 121). 


The dorsal branches are smaller than the ventral; they pass up- 
wards between the inner borders of the Muse. intertransversarii and 
the articular processes of the vertebrae to reach the under surface 
of the MW. longissimus dorsi ; the general course of these nerves is 
very similar for all ; each nerve gives off — 


(a) A twig to the Muse. intertrans- 
versarius and then divides into two 
branches. 


(4) A Ramus muscularis (Fig. 121 
rm), which passes outwards to supply 
the MW. longissimus dorsi. 


re 


(mn) 


| 


ny 


(c) A Ramus cutaneus (Fig. 121 rc); —a 
A KE wi 


this nerve continues under the ex- jy ES 
tensor muscle of the back, running CA i (as 
on the arch of the vertebra towards RC "A 
the middle line; it then pierces the  ,, À \ | » 

muscle and Fascia dorsalis to reach . P 
the large dorsal lymph-sae (Sace. 
cramo - dorsalis), through which it 
courses to end in the skin. In its 


course through the sac the nerve is 
. Dorsal branches of the spinal nerves. The 
connected with a small artery ANC ascia’ ‘doreatis’ Hin dissected, removed 
vein by a small amount of connec-  %™ te ef side, 
re Rami cutanei, 


tive-tissue, the whole being enclosed rm Rami musculares. 


4 
182 THE NERVOUS SYSTEM. 


in a sheath of endothelium continuous with that of the general 
cavity. 

The three anterior cutaneous nerves pierce the Fascia dorsalis near 
the spinous processes, the fourth a little to the side, the fifth perfo- 
rates the M. coccygeo-iliacus at about the junction of its anterior and 
middle thirds; the sixth and seventh perforate the same muscle, 
but more posteriorly. There are seven of these Rami cutanei, the 
first coming from the second spinal nerve, the rest from the suc- 
. ceeding six spinal nerves. 


B. The Ventral Branches. 


The ventral branches of the spinal nerves are larger than their 
corresponding dorsal branches: each nerve gives off immediately 
a Ramus communicans to the sympathetic system (Figs. 117 SM, 
120 C); these Rami communicantes will be described with the sym- 
pathetic system ; the remaining: portions of the ventral divisions of 
the original spinal nerves are usually known as the spinal nerves ; 
they will be described as such in detail. 


1. The hypoglossal nerve ! (VV. hypoglossus, N. spinalis 1), (Figs. 
114, 115, and 117 Mr), or first spinal nerve, is of small size; it 
leaves the vertebral canal between the first and second vertebrae to 
he between the Musculi intertransversarii and the pharynx, where it 
has in front the Arteria vertebralis, behind the Arteria and Nervus 
brachialis ; passing under the Levator anguli scapulae, it touches the 
Aorta ascendens and crosses the Vagus and the Carotid-gland, and 
thus reaches the space between the Musculi sterno-hyoidei and the 
Petro-hyoideus ; then curving forwards sharply it turns under the 
Mylo-hyoideus to course between the fibres of the Genio-hyoideus to 
the root of the tongue, where it ends. It first lies to the inner and 
then to the outer side of the glossopharyngeal nerve. In its course 
the nerve gives off the following branches :— 


(a) One or two communicating twigs (Figs. 114 and 122) to the 
second spinal nerve. 


! [Observers have differed considerably as to the relations of this nerve : Volkmann 
describes it as the first nerve of the neck, and describes a ganglion on its dorsal 
root; Vogt denies the presence of this ganglion, and regards it as a true cranial 
nerve; Stannius asserts that no ganglion exists, and holds the nerve to represent the 
first two spinal nerves; Wyman describes the two roots and regards it as a spinal 
nerve ; Hoffmann regards this nerve as the second spinal (N. spinalis II): Fiir- 
bringer as the representative of two spinal nerves; de Watteville describes two roots 
and names it first spinal nerve.—TRANS. } 


/ 


THE SPINAL NERVES, 183 


(6) Muscular twigs to the Longissimus dorsi, Intertransversarii 
capitis, Levator anguli scapulae, and the Retrahens scapulae. 

(c) When near the glossopharyngeal it supplies twigs to the 
Geniohyoideus, Sternohyoideus, and Omohyoideus, where it bifurcates. 


(d) One of the branches passes inwards to supply the Hyoglossus. 


(e) The other terminal branch passes forwards with the Ramus 
lingualis and the glossopharyngeal, between the fibres of the Genio- 
hyoideus, which it partially supplies, and sends twigs to the neigh- 
bouring parts. 


(f) | Hoffmann describes a communicating branch to the pneu- 
mogastric nerve, which the translator has not been able to discover, 
and which no other observer has mentioned. | 


2. The second spinal or brachial nerve (JV. brachialis, N. spinalis 
IT), (Fig. 122) is a large nerve, leaving the vertebral canal between 
the second and third vertebrae ; it then accompanies the 47t. axil- 
laris along the anterior border of the transverse process of the third 
vertebra, over the hinder end of the J/usc. levator scapulae and the 
anterior end of the m. transverso-scapularis major, to the inner border 
of the Muse. subscapularis, under which it passes into the arm. In 
this course it gives off or receives the following branches :— 

(a) It first receives a branch from the second spinal nerve. 

(4) It gives off a large branch, the N. coraco-clavicularis (Fig. 122 
Cc), which first accompanies a branch of the Art. awillaris on the 
Muse. levat. scapulae, then courses forwards and outwards over the 
Muse. subscapularis to pass from above into the Foramen ovale be- 
tween the clavicle and coracoid bones. It gives off two branches : 

(1) One immediately beyond its origin, which runs backwards 
over the Musc. subscapularis to supply the Musc. oblig. abdominis in- 
ternus (Fig. 122 Cc’). 

(2) While in the Foramen ovale, the N. coraco-clavicularis bifur- 
cates ; the anterior twig runs forwards and outwards to the deltoideus 
and also supplies a recurrent filament to the Musc. sterno-radialis ; 
the posterior twig enters the upper surface of the Muse. sterno- 
radialis. 

(c) At the outer extremity of the Muse. transverso-scapularis the 
brachial nerve gives off a posterior branch, which at once bifureates : 

(1) The first branch passes into the under surface of the Muse. 
latissimus dorsi (Id), giving a twig to the Infraspinatus. 

(2) The second is the Ramus cutaneus axillaris (IIc) ; it passes on 


184 THE NERVOUS SYSTEM. 


the under surface and posterior border of the usc. latissimus dorsi 
to the skin of axilla and dorsal surface of the upper arm. 


(2) Several small branches are given off from the upper and an- 
terior surfaces of the brachial nerve near the Foramen ovale ; they 
accompany an artery to pass forwards and upwards between the 
Muse. subscapularis and the M. transverso-scapularis on the one side, 


Fig. 122. 


The brachial plexus. 


Ce N. coraco-clavicularis ss Muse, subscapularis. 

Cc’ Nerve to muse. obliq. abdom., internus. SI First spinal nerve. 

d Deltoid muscle. SII Second spinal nerve. 

la Muse. ley. ang. scap. SJIT Third spinal nerve. 

ld Muse, lat. dorsi. Ie Ramus cutaneus axillaris, 

ot Muse. obliq. abdom. intern. Ille Ramus cutaneus abdominalis, 


se Muse. sterno-mastoid, 


and the long head of the 17. triceps brachialis on the other, and are 
lost in the IW. de/toideus and the M. infraspinatus. 

The N. brachialis continues its course by passing between the 
long and inner heads of the JV. friceps, reaches the arm and splits 
into two nerves, the NV. w/naris and the NV. radialis. 


[I] The WV. wnaris (Fig. 123 U) escapes from cover of the long 
head of the 27. triceps and runs obliquely over its inner head 


THE SPINAL NERVES. 185 


towards the outer side of the Plica cubiti ; in this course it supplies 
four branches : 

a. The Ramus subscapularis passes dorsally to the IW. sub- 
scapularis. 


B. A Ramus pecto- Fig. 123. 
ralis (Fig. 123 up), 


passes forwards to the 
A1. abdomino-pectoralis 
and to the skin of 
the pectoral region (7. 
cutaneus pectoralis). 


y- The N. cutaneus 
antibrachii superior s. 
medialis (uc) passes 
to the skin of the 


Nerves of the ventral surface of the arm. The hand pronated. 


inner side of the fore- re Upper eutaneons branch of the N. radialis. 
arm ; this and the a rer er branch of the N. radialis. 
= N. ulnaris. 
two following nerves we R. cutan. sup. of the N. ulnaris 
= iS we” R. cutan. inf. of the N. ulmaris. 
are given off near the up R. pectoralis of the N. ulmaris. 


Plica cubiti. 


6. The N. cutaneus antibrachii inferior s. dorsalis 8. musculo- 
cutaneus (uc’) at once supplies branches to the 37. fleror carpi radi- 
alis+, and then runs downwards upon the muscle and bifurcates :-— 

[x] The À. /ateralis is distributed, by two twigs, in the 37. flexor 
carpi ulnaris and in the skin of the second finger, to which it sup- 
plies the Rami digitales rolaris and dorsalis. 

[2] The À. dorsalis, after giving a cutaneous twig to the second 
finger, is distributed by numerous twigs to the skin of the dorsal 
surface of the hand. ; 

The N. wnaris then passes between the W/. jleror carpi radialis and 
the tendon of the VW. sterno-radialis, sinks deeply into the Plica 
cubiti, where it hes between the WM. fleror carpi radialis and the 
Flexor carpi ulnaris, then between the latter and the Fleror anti- 
brachii medialis on the one side and the Flexor digitorum communis on 
the other: it supplies branches to all these muscles, and while still 
in the forearm divides into two terminal branches :— 

a. The À. w/naris medialis is the smaller; it runs inwards, 


* As this muscle increases in size during the breeding season, it would be inter- 
esting to know whether a corresponding change takes place in the nerve. 


186 THE NERVOUS SYSTEM. 


passes under the tendon of the MZ. extensor carpi ulnaris into the 
palm of the hand and ends as the WV. volaris digiti V medialis. 


Nerves of the ventral surface of the arm. The hand 
supinated, and the superficial layer (Flex. carpi rad. 
and uln., Flex. dig. commun.) has been removed. 


R  N. radialis. 

u N. ulnaris. 

ue  R. cutan. inf. of the N. ulnaris. 
um Bifurcation of the N. ulnaris. 


B. The À. ulnaris lateralis 
passes near the thumb-rudi- 
ment, covered by the J. ab- 
ductor pollicis, deeply into the 
palm of the hand, and supplies 
by bifurcating branches the 
adjacent sides of the second, 
third, fourth, and fifth fin- 
gers (À. volares) ; it also gives 
twigs to the muscles of the 
palm. 

[1I.] The N. radials (Figs. 
123, 124, and 125 À) passes 
immediately beyond its origin 
from the W. brachialis, between 
the humerus and the 7. triceps, 
runs along the bone to its 
outer side; in this course it 
gives off :— 


a. Rami musculares to the separate parts of the M. triceps. 
B. The Ramus cutaneus superior (Fig. 125 re) to the skin of 


Fig. 125. 


The N. radialis, 


ec  M. extensor carpi ulnaris. 


ed Mz. extensor digit. comm. 
RN. radialis. 

Rx R. lateralis. 

R2 RK. medialis. 

re. cutaneus superior. 

re’ Rk, cutaneus inferior, 


the outer surface of 
the upper arm and fore- 
arm. 


The nerve then sinks 
deeply under the origins 
of the W. extensor car 
ulnaris and the M. ex- 
tensor digitorum commu- 
nis, Where it bifurcates 
after giving off some 
small twigs : 


y. Small muscular 
twigs to the extensor 
muscles of the hand and 
fingers. 

6. The ZX. radialis 
medialis  (R2), the 


THE SPINAL NERVES. _ 187 


smaller terminal branch, supplies a branch to the 47. extensor digit: 
comm. longus and the skin over the carpus (Ramus cutaneus inferior, 
rc’), and ends on the muscles of the little finger as the A. dorsalis 
digiti V medialis. 

e. The ZX. radials lateralis (R), the larger of the two branches, 
supplies the extensor muscles of the fingers and gives bifurcating 
branches, Rami digitales dorsales, to the adjacent sides of the second, 
third, fourth, and fifth fingers (the Ramus dorsalis lateralis of the 
second finger is supplied by the N. w/naris). 


3. The third spinal nerve (NV. spinalis IT) (Fig. 122 SII/) leaves 
the vertebral canal by the foramen between the third and fourth 
vertebrae, and runs outwards and forwards upon the large transverse 
process of the third vertebra to the brachial nerve (NW. spinalis IT). 
Its behaviour at this point is subject to considerable variation ; at 
times it joins the brachial nerve completely, at other times the two 
nerves are simply in contact ; or lastly, it may send a small twig 
to the brachial nerve. Externally to this point the two nerves 
supply a number of small branches, which may belong almost en- 
tirely to either one nerve or the other ; these nerves again inosculate 
in a variable manner, to form an axillary plexus. The more con- 
stant branches are :— 

(1) One or more twigs to the Muse. transverso-scapularis major. 

(2) Several branches, usually two larger and one smaller; they 
course in the M. oblig. abdom. internus (Fig. 122 où) to the MW. rectus, 
where they give off branches, then pierce the muscle to reach the 
skin (2. cutaneus abdominalis), (Fig. 122 IIIe). 


4, The fourth spinal nerve (NV. spinalis IV) (Fig. 126 M4) 
appears between the fourth and fifth vertebrae; it runs on the 
ventral surface of the transverse process of the fifth vertebra and 
upon the Muse. intertransversarius obliquely outwards and down- 
wards, and reaches the deeper surface of the Muse. obliquus internus, 
into which it descends, about opposite the articulation between the 
eighth and ninth vertebrae ; it then bifurcates into :— 

(1) A Ramus cutaneus abdominalis, which pierces the muscle and 
supplies the skin. 

(2) A Ramus muscularis, which supplies the broad abdominal 
muscle and the 7. rectus abdominis. 


5. The fifth spinal nerve (NV. spinalis V) (Fig. 126 M5) emerges 
through the foramen between the fifth and sixth vertebrae, runs 


188 THE NERVOUS SYSTEM. 


obliquely downwards and outwards over the transverse processes of 
the sixth and seventh vertebrae and the corresponding J. infer- 


Fig. 126. 


Ventral view of the brain and spinal cord, to show the 
points of exit of the spinal nerves, 


Mi-10 Spinal nerves. 

VG Trigeminal ganglion, 
Wi-10 Vertebrae. 

XG Ganglion of the vagus. 


transversarii, and at a 
point nearly opposite 
the middle of the uro- 
style pierces the 47. 
obliquus internus. 

The rest of its course 
corresponds exactly 
with that of the fourth 
spinal nerve. 


6. The sixth spinal 
nerve (NW. spinalis VI) 
(Fig. 126 M6), after 
escaping from the ver- - 
tebral canal: between 
the sixth and seventh 
vertebrae, runs ob- 
liquely downwards and 
outwards on the under 
surfaces of the trans- 
verse processes of the 
seventh, eighth, and 
ninth vertebrae, then 
under the iliac bone to 
a point opposite the 
hinder half of the uro- 
style, where it descends 
under cover of the 17. 
obliquus abdom.internus. 
In the rest of its course 
it repeats the corre- 
sponding courses of the 
fourth and fifth spinal 
nerves. 


7,8,9,and10. The 
seventh, eighth ninth, 
and tenth  spinal 
nerves (Nervi spinales 


VII, VIII, IX, and N. spinalis X s. N. coccygeus) (Figs. 126 and 


THE SPINAL NERVES. 189 


127 My, M8, Mg, and Mio) are best described together, as 
they are intimately associated to form the sciatic plexus (Pleaus 
ischiadicus, Plexus cruralis). 

Within the vertebral canal the roots of these nerves form the 
Cauda equina; the seventh nerve leaves the canal between the 
seventh and eighth vertebrae, the eighth nerve between the eighth 
and ninth vertebrae, the ninth between the sacrum or ninth ver- 
tebra and the urostyle, and the tenth by the Canalis coccygeus in 
the urostyle ; from these points the four nerves run obliquely on 
the ventral surface of the J/. iio-coccygeus to the pelvis, where they 
form the sciatic plexus. Although subject to some variation, the 
usual arrangement is that the seventh and eighth nerves unite to 
form a trunk, which then receives the ninth nerve ; the large nerve 
so formed is the sciatie nerve: a branch of the tenth usually then 
joins either the sciatic plexus or the sciatic nerve; the plexus gives 
off or receives the following branches. :— 

(a) Like other spinal nerves, these nerves give off Ram communi- 
cantes (see Sympathetic System). 

(4) The M. iio-hypogastricus (Fig. 127 Mya). This arises from 
the seventh spinal nerve, before its union with the eighth spinal 
nerve ; it runs obliquely outwards and downwards on the Jus. 
ilio-coccygeus and under the border of the 47. obliquus abdom. in- 
ternus, Where it bifurcates :— 


(1) One branch, the Ramus cutaneus abdominalis, pierces the 
M. oblig. abdom. internus in the same fashion as the cutaneous 
branches of the fourth, fifth, and sixth spinal nerves; it supplies 
the skin of the abdomen. 

(2) The second or Ramus muscularis supplies the flat abdominal 
muscles and the MZ. rectus abdominis. 


(c) The 27. cruralis (Fig. 127 1/74) also arises from the seventh 
spinal nerve at or just beyond its point of union with the eighth 
spinal nerve. It accompanies the 4. cruralis on the pelvic wall to 
the thigh, where it lies upon the J. i/io-psoas in a triangle between 
the A. rectus fem. anterior and the M. adductor longus, and divides 
into two main branches :— 

(1) Muscular twigs to the I. ilio-psoas, M. rectus femoris anticus, 
MM. adductores longus and brevis. 

(2) The Ramus cutaneus femoris, which runs downwards in the 
hinder wall of the Lymph-sae (Saccus iliacus), and supplies the skin 
of the under and outer surfaces of the thigh. 


190 THE NERVOUS SYSTEM. 


(d) The Ramus dorsalis is a very small nerve; according to 
Waldeyer it possesses only twenty nerve-fibres. It arises from 


The sciatic plexus, from a drawing by Wiedersheim. 


a Communicating nerve from the ninth spinal Ao Aorta. 
nerve. Com Point of union of nerves a and ce. 
a’ Nerve to muse. ley. ani. Is Ischium. 
b Nerve to oviduct. Ms Fifth spinal nerve. 
e  Urostyle. M6 _ Sixth spinal nerve, 
ce Communicating twig from the ninth spinal M7 Seventh spinal nerve. 
nerve. Ms _ Eighth spinal nerve. 
ci M. coccygeoiliacus. Mo Ninth spinal nerve. 
e.I M. coccygeosacralis. Mio Tenth spinal nerve. 
d Nerve to bladder. M7za M. iliohypogastricus. 
d’ Twig to the m. iliacus. M7b M. cruralis. 
e Twig from sciatic plexus to coccygeal plexus. Ni  $Sciatic nerve. 
à Mz. intertransversarius. Ovd Oviduct, 
à M. ilio-coccygeus. Rect’ Rectum. 
ip M. ilio-psoas, S87, §8, So, Sto Rami communicantes of seventh, 
lev M. lev. ani. eighth, ninth, and tenth spinal nerves, 
oi M. obliq. abdom, internus. Tes Bladder. 
Transverse process of sacrum. 8,9 Eighth and ninth vertebrae, 


THE SPINAL NERVES. 191 


the coccygeal nerve immediately beyond the Canalis coccygeus, 
perforates the M. i/io-coccygeus, and runs on its dorsal surface 
obliquely over the lymph-heart, without supplying it; the nerve 
then pierces the fascia to supply the skin of the back and thigh. 


(e) The Ramus abdominalis also arises from the coccygeal nerve ; 
it is larger than the R. dorsalis, and arises at the same point; the 
nerve runs on the ventral surface of the 17. i/io-coccygeus towards the 
lymph-heart, and inosculates with the sympathetic. It is from this 
nerve that the branch to the sciatic plexus is usually given off ; it 
further supplies a varying number of branches, which with branches 
derived directly or indirectly from the sciatic nerve, form a plexus 
(Plexus coccygeus) ; the two plexuses may together be regarded as a 
Plexus ischio-coccygeus or a Plexus sacro-coccygeus. 


(f) In addition to the Rami communicantes given off by the spinal 
nerves near the vertebral column, the sciatic plexus supplies a few 
twigs, usually two (Fig. 127). 


(g) Other small twigs pass from the sympathetic system for- 
wards and outwards to join the sciatic plexus or the sciatic nerve. 
According to Waldeyer two of these are very constant. 

(2) Branches to the oviduct (Fig. 127 4). 

(4) Branches to the rectum (Fig. 127 cc). 

(4) Branches to the bladder (Fig. 127 d). 

(7) Branches to the 7. levator ani (Fig. 127 a’). 

(m) A branch to the lymph-heart, which runs along the anterior 


border of the J/. /ev. ani, on to its dorsal surface, and then direct to 
the lymph-heart. 


Variations in the sciatic plexus. The arrangement of the 
nerves in the sciatic plexus is subject to many variations ; ac- 
cording to Wiedersheim most of these variations belong to two 
chief classes : either the N. coccygeus imosculates directly with the 
ninth spinal nerve by one or several branches, or it joins the ninth 
nerve indirectly by uniting with its branches. A case of the 
latter arrangement is seen in Fig. 127, and is thus described by 
Wiedersheim :— 

‘After cutting through the pelvic symphysis and drawing to one 
side the contained viscera, namely, the hinder end of the oviduct, 
the rectum, and the bladder, one sees a row of small twigs (a, b, 
ce, d, and e) arising from the inner, hinder, and anterior surfaces of 
the ninth spinal nerve: the first (2) runs backwards parallel with 


192 THE NERVOUS SYSTEM. 


the WV. coccygeus over the A. ilio-coccygeus to join this nerve at the 
point marked Com. The twig ce behaves in like manner after re- 
ceiving a twig from 4. The twig 4 arises from the inner surface of 
the ninth nerve between the two foregoing and close to its union 
with the eighth spinal nerve ; from this origin twig J passes almost 
transversely outwards to the hinder extremity of the oviduct 
(“uterus”), and partly to the rectum, crossing in its course twig a, 
the sciatic nerve, and the urostyle. Its branches form a net- 
hike plexus with the terminal branches of the last sympathetic 
ganglion and with a branch cc from the point of union Com. 

‘A second branch (w’), arising from the point of junction Com, is 
a continuation of the NV. coccygeus (M10); it passes vertically down- 
wards towards the hinder end of the cloaca and at the upper border 
of the Levator ani, divides into two branches, which are distributed 
to the inner and outer surfaces of this muscle and to the cloaca. 
Other branches pass dorsally to the lymph-hearts, while a third set 
pass to the hindermost part of the bladder. 

‘These three sets of nerves, to the M. coccygeus, M. levator ani, 
and to the lymph-hearts, are not supplied entirely by the N. coccy- 
geus, as this is reinforced by one or more branches (e) from the 
sciatic plexus: this branch (e) supplies twigs to the I. i/io-coccygeus, 
which is also supplied anteriorly from the trunk of the WV. coccygeus. 

‘The bladder receives a special branch (4), which arises from the 
sciatic plexus at the junction of the eighth and ninth spinal nerves ; 
this nerve gives a twig (d’) to the 17. iiacus, 


I. The sciatic nerve (JV. ischiadicus) (Fig. 128 I) is the largest 
nerve of the body; it passes under the JZ. coccygeus, between the 
origins of the J/. vastus eaternus and of the MW. pyramidalis : les then 
between the 47. biceps and the 17. pyramidalis, and later between the 
M. biceps and the M. semimembranosus ; lastly, it bifureates under 
the MW. biceps to form the N. tibialis (IT) and the N. peroneus (IIT). 
In this course it gives off :— 

(a) A twig to the IZ. coccygeo-iliacus, while still in the pelvis. 

(4) The N. cutaneus femoris posterior (Fig. 128, 2), which passes be- 
tween the 17. pyramidalis and the 17. vastus externus, to appear behind 
and beneath the former ; it accompanies an artery of like name to 
supply the skin of the hinder and inner surfaces of the thigh. 

(c) A little below the foregoing it gives off a collateral branch 
(Fig. 128, 3), which passes under the I. pyramidalis and divides to 
form— 


THE SPINAL 


(1) A branch to the upper third of the J/. semimembranosus. 


(2) A branch to the Rectus internus minor. A twig of this 
branch (44) pierces the muscle transversely in company with the 


Arteria cutanea, and passes to the skin of the middle of the inner 


surface of the thigh. 


( 3) Branches to both heads of the semitendinosus. 


(4) Branches to the J/. adductor magnus. 


(4) Branches covered by 
the M. pyramidalis to the 
M. quadrat. femoris and M. 
obturator. 


(e) A branch (5) forwards 
to the MW. biceps. 


(f) A branch (6) which 
accompanies the Art. cireum- 
Jlexa genu lateralis sup. for- 
wards to the MW. extensores 
cruris, the M. vastus externus, 
and the J/. rectus anterior. 


Distribution of the sciatic nerve. 


I The sciatic nerve. 

II N. tibialis, 

IIT N. peroneus. 

I Branches to the M. pyramidalis. 

2 N. cut. fem. posterior. 

3 Large collateral branch. 

5 Branch to the M. biceps. 

6 Branch accompanying the art. cir- 
cumfl. genu lateralis sup. 

7 Branch of tibial nerve to the M. gas- 
trocnemius. 

8 N. suralis. 

ad’” M. adductor magnus. 

b M. biceps. 

bb Twig accompanying the art. cutanea. 

ci M. coccygeo-iliacus. 

cp N. cut. cruris lateralis. 

et R. cut. cruris posterior. 

g M. gastrocnemius, 

gl M. glutaeus. 

p M. pyramidalis. 

pe M. peroneus. 

ra M. rectus anterior. 

ri’ M. rectus internus minor. 

sm M. semimembranosus. 

st M. semitendinosus, 

ve M. vastus externus, 


© 


194 THE NERVOUS SYSTEM. 


II. The Nervus tibialis (Figs. 128 II, 129 T) passes backwards 
and inwards to supply the extensors of the foot and the flexors of 


the toes. Its branches are :— 


(a) The ZX. cutaneus cruris posterior (Figs. 128 and 129 ct), ac- 
companied by an artery and vein, passes to the skin of the calf. 


(ë) A twig to the upper part of 


Fig. 129. 


the gastrocnemius (Fig. 129 9’). 
The main nerve, after supplying 
this twig, bifurcates to form the 
next two nerves. 

(ec) The Nervus suralis (Figs. 
128, 8; 129 s) runs downwards 
on the inner border of the J/. 
gastrocnemius and gives off :— 

(1) A twig (7”) to the upper 
third of the muscle. 

(2) The Ramus cutaneus me- 
dius (es) is given off below the 
middle of the 17. gastrocnemius ; 
it passes to the skin of the 
lower third of the leg. After 
giving off the latter branch, the 
N. suralis runs downwards along: 
the inner aspect of the Zendo 
achillis to the Aponeurosis plan- 
laris of the sole of the foot 
as far as the calcar, and gives 


0 


Nerves of the leg and sole of the foot. 


abs Branch to the M. abduct. digit. V, 
ads Branch to the M. adduct. digit. V. 


ar M. rectus anterior, 

b M. biceps. 

cs Ramus cutaneus medius. 

ct Ramus cutaneus cruris posterior, 


dvI Ramus digitalis volaris I. 

dvIl Branch supplying R. digit. volaris I 
and II. 

dvIII Second branch of the N. tibialis, 

Fs Branch to the M. flex. brev. digit. V. 

tlp Branches to the M. plantaris and the 
M. flexor digitorum. 

g Branch to the M. gastrocnemius, 

g’ Branch to the M. gastrocnemius. 

pe N. peroneus. 

s N. suralis. 

sm M. semimembranosus. 

T,t Nervus tibialis, 


THE SPINAL NERVES. 195 


(3) Branches (fly) to the Musc. plantaris and the M. flexor 
digitorum. 


(4) A branch to the WZ. abductor hallucis. 

(5) The &. digitalis voiaris I (dvI) supplies the inner side of the 
first toe by its terminal twig’. 

(d) The Nervus tibialis (Fig. 129 ¢) passes downwards on the 
hinder surface of the tibio-fibula, sinks into the I. tibialis posticus 
to appear again at its hinder border; it then runs over the ankle- 
joint into the sole of the foot, where it lies midway in the space 
between the two Ossa tarsi and between the 17. extensor tarsi and the 
M. abductor digiti I longus ; the nerve then runs downwards in the 
groove of the small Os ¢arsi and divides to form three branches :— 


(1) The first branch (dvJZ) runs to the space between the second 
and third fingers, where it bifurcates :— 

(a) The Ramzi digital. volaris I run transversely over the muscles 
of the second toe, supply the muscles of the first toe, and bifur- 
cate to form the 2. digital. volaris I and IT. 

(8) The Ram. digit. volar. II divides in the space between the 
second and third fingers to supply the Flex. phalang. and the adjacent 
sides of these toes. 


(2) The second branch (¢/vJ/Z) runs over the M/. flex. metatarsi of 
the third toe to the space between the third and fourth toes, and 
bifurcates to supply the adjacent sides of these toes and the web 
between them. 

(3) The third branch at once divides to supply :— 

(a) The MW. transv. metatarsi. 

(8) The MM. lumbricales of the fourth toe. 

(y) The M. abductor digit. V (ab5), the M. flewor brevis dig. V 
(F5), and the MW. adductor dig. V (ad5) ; it then ends as— 


(à) A bifurcating branch forming the 2. digit. volar. of the fourth 
and fifth toes. 


III. The Nervus peroneus (N. peroneus communis superior, Ecker), 
(Fig. 130 pc) is the second division of the sciatic nerve; it passes 
between the outer head of origin of the A7. gastrocnemius and the 
tendon of insertion of the JZ. biceps, it then lies on the tibio-fibula 
between the /. gastrocnemius and the M. peroneus, where it is ac- 
companied by the Vena tibialis postica, then runs downwards upon 
the I. extensor cruris and the Flexor tarsi ant., and passes under 
the M. tibial. anticus and bifurcates ; its branches are :— 

OP 2 


196 


THE NERVOUS SYSTEM. 


a. The NV. cutaneus cruris lateralis (Fig. 128 cp); which, like other 
cutaneous nerves, runs in a common sheath together with an artery 


and vein to the skin. 


It arises close to the sciatic nerve. 


b. Muscular branches to the WM. peroneus, tibialis anticus, extensor 
cruris brevis, and the flewor tarsi anterior. 


Distribution of the NV. peroneus. 


A Inner terminal twig of N. peron. comm. 


inf. 


B Outer terminal twig of N. peron, comm, 


inf. 
cpl N. cutaneus dorsi pedis lateralis. 
pe N. peroneus. 
pet N. peroneus communis inferior 
pl N. peroneus lateralis, 
pm N, peroneus medialis, 


ferior (Ecker). 


e. The N. peroneus medialis (Fig. 
130 pm) is the smaller of the two 
terminal branches of the N. pero- 
neus ; 1t courses with the drt. tibi- 
alis antica under the MM. flexores 
tarsi anterior and posterior and sup- 
plies the latter. 


d. The JN. peroneus lateralis (Fig. 
130 pl) is the larger terminal branch 
of the WV. peroneus ; it passes down- 
wards between the heads of the J/. 
tibialis anticus to the tendon of origin 
of the Flexor tarsi posterior, where it 
gives off two branches (Nos. 1 and 2); 
the nerve then unites with the JN. 
peroneus lateralis to form a common 
stem, the N. peroneus communis in- 
The A. peroneus 
lateralis gives off :— 

(1) The N. cutaneus dorsi pedis 
lateralis (cpl), which passes to the 
skin of the outer side of the 
dorsum of the foot. 

(2) A second branch to the 17. ex- 
tensor of the fourth and fifth toes. 


e. The NW. peroneus communis in- 


ferior (Fig. 130 pci) runs on the 


dorsum of the foot in company with 
the Art. dorsalis pedis, underneath 
the MM. extensores digiti I and IT; 
it supplies several branches and then 
bifurcates. It gives off :— 

(1) Branches to the 1/1. extensor 
longus and brevis digiti I. 


THE SYMPATHETIC SYSTEM. 197 


(2) Rami digitales dorsales to the adjacent sides of the first and 
second toes. 

(3) Branches to the IZM. extensores digiti IL. 

(4) The inner, terminal branch (Fig. 130 4) at once divides :— 

(a) The outer branch runs between the third and fourth toes as 
far as the commencement of the web, where it bifurcates to form 
two Rami cutanei, which course along the adjacent sides of these 
toes as far as their apices. 

(8) The inner branch passes to the extensor muscle, and, in part, 
to the adjacent sides of the third and fourth toes. 

(5) The outer, terminal branch (Fig. 130 B) of the N. peroneus 
communis inferior passes to the muscles of the fourth and fifth toes, 
and supplies Rami cutanei dorsales to the outer side of the fourth 
and inner side of the fifth toes. 

_ Cutaneous branches of the N. ¢idia/is supply the outer side of the 
fifth and inner side of the first toe. 


G. Tue Symparuetic System (Sympathicus). 
(Re-written by the translator.) 


The sympathetic cord.or chain is a row of nervous ganglia 
(vertebral or lateral ganglia), connected by nerve-fibres, and lying 
on either side of the vertebral column (Figs. 117 and 131); with 
the exception of the last spinal nerve there is usually one sympa- 
thetic ganglion associated with each spinal nerve ; in the case of the 
tenth spinal nerve there may be only one ganglion or as many 
as twelve. 

The first ganglion (Figs. 111, opposite ics; 117 S1) is placed on 
the hypoglossal nerve just as it emerges from the first intervertebral 
foramen; it is large, but smaller than the second; its Ramus 
communicans is represented by several fine and very short fibres, 
which connect the ganglion with the nerve. This ganglion is con- 
nected with the second by two or three nervous threads, between 
which passes the subclavian artery, a true Annulus Vieussenii being 
thus formed (de Watteville). The other ganglia are connected by 
single bands of fibres. The first ganglion supplies also branches to 
the axillary artery and to the cardiac plexus. 

The second ganglion (Figs. 117 and 131) is the largest, and is 
closely applied to the brachial nerve ; as in the case of the first 
ganglion and hypoglossal nerve, it is attached to the second spinal 
nerve without a distinctly marked Ramus communicans. 


198 THE NERVOUS SYSTEM. 


The third ganglion (Gaxglion cardiacum basale, Gaskell and Gadow) 
is sometimes fused with the second, but is usually close to the third 
spinal nerve: it has a short but distinct Ramus communicans. 

Behind the third ganglion the sympathetic cord is continued back- 
wards along the corresponding aortic arch, then parallel with and 
close to the abdominal aorta (Figs. 117, 127, and 131), receiving 

Fig. 131. Rami communicantes, which are 
long and well marked, from 
each of the spinal nerves ; 
the fourth, fifth, and sixth 
nerves usually supply each 
one Ramus communicans, the 
seventh two, and the eighth 
and ninth each two or three : 
from the tenth nerve it re- 
ceives three or more, as many 
as twelve having been noted. 
The ganglia are usually more 
or less spindle-shaped or flat- 
tened and triangular; the 
hinder part of the cord usually 
receives in addition two or 
three branches from the sciatic 
plexus and twigs from the 
R. abdominalis of the N. 
coccygeus. : 


The branches and commu- 
nications of the sympathetic 


Sympathetic cord. From Ecker (Icones physiologicae, es i 
Pl, XXIV, Fig. 3). cords are as follows :— 
The heart, lungs, and liver have been removed ; the : : 
stomach, intestine, kidneys, and testes drawn tothe a. Communicating branches 


right side ; the left sympathetic cord is thus pulled . 
to the right side to expose the Rami communicantes. between the two cords ) these 


S Sympathetic cord attached to the ganglion of the are extremely numerous and 


vagus. : : ° 

a bel oOo - 
The numbers refer to the ganglia, which are enumer- ae regular, for mime net like 
ated from before backwards. plexus n which surrounds the 


abdominal aorta and other adjacent structures, and gives off 
numerous small twigs to the neighbouring vessels and organs. 


b. Communications with the cranial nerves; these are two 
branches (Wiedersheim), (Figs. 111 and 116) which pass from the 
first ganglion to the Ganglion nervi vagi, where one terminates, the 
other leaves the ganglion to pass on to the Gasserian ganglion 


THE SYMPATHETIC SYSTEM. 199 


(Figs. 111 and 116 VS): according to Gaskell a sigle nerve passes 
from the first ganglion to the Ganglion nervi vagi, whence one 
portion of its fibres is continued to the Gasserian ganglion, the re- 
mainder accompanying the pneumogastric nerve without any con- 
nection with the ganglion; he therefore names this nerve the 
vago-sympathetic. (See Gasserian ganglion, p. 168.) 

e. Communications with the spinal nerves ; these are :-— 

(1) The Rami communicantes. 

(2) Communications between the sympathetic ganglia or their 
branches and the spinal nerves or their branches (Fig. 117) ; by, 
means of these connections, fibres of the sympathetic system are : 


conducted by the spinal nerves and their branches to all parts of 
‘the body. 


d. Branches to the heart, which form the following ganglia :— 

(1) A relatively large plexus lies on the auricles in the median 
plane immediately beneath the division of the J/. hyoglossus. It 
supplies a network of fibres to the auricles and the adjacent large 
vessels. It is said to communicate at various points with the 
pneumogastric nerve. 

(2) A smaller ganglion of oval form, supplies twigs to the 
neighbouring vessels and a communicating branch to the hypo- 
glossal nerve (Wiedersheim). 


e. Branches to the abdominal viscera; these form intricate 
plexuses by which the organs are supplied: the one best known 
is the solar plexus (Fig. 131); it is formed chiefly from branches 
derived from the third, fourth, and fifth ganglia, and supplies 
the stomach, ete.; other plexuses for the various viscera are known 
by corresponding names, such are the Plexus hepaticus, renalis, geni- 
talis, haemorrhoidalis, and vesicalis. 

The sympathetic system is characterised by the fact that the 
branches form intricate plexuses, which include numerous ganglia 
and which are very irregular; it is also characteristic that most 
of its fibres are non-medullated. According to the mvestigations 
of Gaskell, the fibres of the sympathetic system arise in mam- 
malia as very fine medullated fibres from the posterior vesicular 
(Clarke’s) columns (Mason has recently described cells in the 
frog’s spinal cord, which he holds to be homologous with the cells 
of these columns) ; they leave the cord by both the ventral and 
dorsal roots of the spinal nerves, and are thus connected with two 
sets of ganglia, (1) with the ganglia of the dorsal roots, and (2) 


200 THE NERVOUS SYSTEM. 


through the Rami communicantes with the sympathetic ganglia (ver- 
tebral or lateral ganglia); these two sets of ganglia Gaskell terms 
proximal. By means of the branches from the sympathetic ganglia 
(Rami efferentes) part of the fibres pass to another set of ganglia, the 
solar plexus, ete., which he terms prevertebral or collateral ; from 
these the fibres pass to be distributed to the various viscera and blood- 
vessels, where a fourth set of very small ganglia (terminal ganglia) 
is found. The prevertebral and terminal ganglia are together classed 
as distal ganglia. Gaskell holds that the fine medullated fibres 
from the cord lose their medullary sheath in one or other of these 
ganglia according to the function they fulfil. 

The inhibitory fibres of the heart and vaso-dilator fibres of the 
blood-vessels continue as white fibres along the vago-sympathetic and 
spinal nerves to the distal ganglia (Bidder’s ganglion, etc.), where 
the medullary sheath disappears: whereas the ‘augmentor’ fibres of 
the heart and vaso-constrictor fibres of the blood-vessels lose their 
medullary sheath in the proximal ganglia and pass on as non- 
medullated fibres. In the same way the nerve-fibres that bring 
about contraction of the circular muscle fibres of the hollow viscera 
lose their medullary sheaths in the proximal ganglia, while those 
fibres, the influence of which negatives the former, become pale 
fibres in the distal ganglia. 

Waters has demonstrated that in the frog the various spinal 
nerves have each a localised physiological action upon the blood- 
vessels and muscular walls of various parts of the alimentary canal: 
he shows that 

The third spinal nerve supplies the oesophagus. 

The fourth spinal nerve supplies the stomach. 

The fifth spinal nerve supplies the upper third of the small 
intestine. 

The sixth spinal nerve supplies the lower two thirds of the small 
intestine. 

The seventh spinal nerve supplies the large intestine. 

The eighth spinal nerve supplies the bladder, this supply being, 
however, not so definite as the others given above. 

It has long been known that the branches of the spmal ganglia 
(ganglia of the posterior roots) are together larger (one-third, 
Lenhossék), and contain more fibres than the ventral and dorsal 
roots together ; this is supposed to be in part due to an acquisition 
of new fibres derived from the ganglia. The majority of recent 
observers hold that each ganglionic cell has only one process, which, 


THE STRUCTURE OF THE NERVE-FIBRES SYSTEM. 201 


however, soon bifurcates ; whether any of the fibres so formed pass 
as far as the cord or beyond its blood-vessels is doubted by most ob- 
servers, and denied by Gaskell. These remarks and the description 
of the cells of the spmal ganglia (p. 176) hold good for the lateral 
or vertebral ganglia and the prevertebral ganglia (solar gan- 
ghon, etc.) of the sympathetic system; the terminal ganglia will 
be described with the organs in which they are found. 


H. Hrsrococicaz Notes on THE NERVOUS System. 


(In order to render the foregoing description of the nervous system more complete, 
the following notes have been added by the translator.) 


| The histological elements of the nervous system are nerve-cells 
and nerve-fibres ; of these the nerve-cells have been described with 
the parts in which they occur; it may simply be remarked that 
later observers have been unable to discover the ‘ spiral cells’ de- 
scribed by Beale, Arnold, and others. The nerve-fibres, as in most 
other animals, are of two kinds, medullated and non-medullated. 


1. Medullated nerve-fibres or white fibres are found in all cranial 
and spinal nerves, with the exception of the olfactory nerves, and 
in many of the sympathetic nerves (see Sympathetic System) ; 
also in the white matter of the brain and spinal cord; examined 
microscopically the fibres are seen to consist of an external sheath or 
neurilemma, a medullary sheath, and an axis-cylinder :— 


a. The neurilemma (Sheath of Schwann, Outer or Primitive 
Sheath) is a nucleated endothelial layer covering the nerve-fibre ; 
it is continuous with the corresponding coat of the nerve-cells, and 
is uninterrupted throughout the length of the nerve ; at the nodes, 
however, it dips down towards the axis-cylinder, the circular groove 
so formed being: filled with cement substance. 


b. The medullary sheath (White substance of Schwann); the 
presence of this sheath is the chief cause of the whiteness of these 
nerves ; the thickness of the sheath varies considerably, and towards 
the ultimate distribution of the nerve it is entirely lost. At more 
or less regular intervals along the course of the nerve-fibre the 
continuity of the medullary sheath is broken, and gives the 
fibres the appearance of being constricted at these places ; such 
constrictions are known as nodes of Ranvier; the portion between 
two such nodes being termed an internode. Each internode 
possesses an oval, flattened, granular nucleus at about its middle 


202 THE NERVOUS SYSTEM. 


and placed between the neurilemma and the medullary sheath ; the 
nucleus has a nucleolus. In the fresh state the medullary sheath 
seems to be fluid; it is of a fatty nature. 


Medullary segments are caused by breaks in the continuity 
of the medullary sheath, which are seen only in nerves which are 
no longer in their normal condition, and are especially well marked 
after treatment with osmic acid.. The breaks are oblique ; hence the 
conical end of one segment fits into the funnel-shaped end of the next. 
How far they correspond to pre-existent structures is uncertain. 
The segments in the frog vary in length from o:o10 to 0-040 mm. 


ce. The axis-cylinder is the essential part of every nerve-fibre ; 1 
shows a longitudinal striation corresponding to the fine fibrils 
(primitive fibrillae) of which it consists ; these fibrils often exhibit 
minute varicosities: at times it has the appearance of being in- 
vested with a very delicate structureless sheath. It is continuous 
through the nodes of Ranvier. 


2. Non-medullated nerve-fibres (Grey or Varicose Fibres ; Fibres 
of Remak); these occur chiefly in branches and plexuses of the 
sympathetic system; they consist of a neurilemma and an axis- 
cylinder, which agree exactly with the corresponding elements 
found in the medullated fibres. 


The nerve-fibres, whether medullated or non-medullated, are 
bound together by connective-tissue to form nerves. A number of 
fibres bound together by connective-tissue to form a slender cord 
is known as a funiculus ; a small nerve may consist of one such 
funiculus ; the sheath surrounding it is known as the perineurium, 
and sends in supporting processes between the fibres (endoneurium) : 
when several funiculi are bound together to form a large nerve the 
common sheath is known as the epineurium, These sheaths support 
nerves (vervi nervorum) and vessels (vasa vasorum) supplying the 
nervous elements, and their intercellular spaces form lymph-canals. 
The whole nerve is surrounded by an endothelial coat, which helps 
to form a lymph-space, which more or less completely surrounds 
the nerve. 

The ultimate distribution of the nerve-fibres will be included in 
the description of the various organs in which they end. | 


SECTION: IV: 


THE VASCULAR SYSTEM. 


PA ve 4 
NE L 
“et oe CA, 


(cry LIL 


THE VASCULAR SYSTEM. 


LITERATURE. 


THE HEART AND BLOOD-VESSELS. 


Aeby, Ueber den feineren Bau der Blutcapillaren. Centralbl. f. d. med. Wiss. 
1865, p. 209. 

Altmann, R., Ueber Corrosion in der Histologie. Centralbl. f. d. med. Wiss. 1878, 
P- 245- 

Aubert, H., Die Innervation der Kreislaufsorgane. Hermann’s Handbuch der 
Physiologie. Leipzig, 1880. Vol. VI, Pt. I, p. 377. 

Beck, K., Zur Kenntniss der Herznerven. Arch. f. mik. Anat.1884. Vol. XXIV, 
PP: I1-19. 

v. Bezold, Untersuchungen tiber die Innervation des Herzens. Leipzig, 1863. 

Bidder, F., Ueber functionell verschiedene und räumlich getrennte Nervencentra 
im Froschherzen. Arch. f. Anat. u. Physiol. 1852, p. 163. 

Bidder, F., Zur näheren Kenntniss des Froschherzens und seiner Nerven. Arch. f. 
Anat. u. Physiol. 1866, p. I. 

Bidder, F., Endigungsweise der Herzzweige des N. vagus beim Frosche. Arch. f. 
Anat. u. Physiol. 1868, p. 1. 

Bidder, F'., and Gregory, Beiträge zur Physiologie der Herzbewegung beim Frosche. 
Dorpat, 1865. 

Boas, J. EH. V., Ueber den Conus arteriosus und die Arterienbogen der Amphibien. 
Morph. Jahrb. 1881. Vol. VII, pp. 271-273. 

Boas, J. E. V., Beitrige zur Angiologie der Amphibien. Morph. Jahrb. 1882. 
Vol. VIII, pp. 169-187. 

Bobretzky, C., Ueber die Entwickelung der Capillargefässe. Centralbl. f. d. med. 
Wiss. 1885, p. 769. 

Bremer, L., Die Nerven der Capillaren der kleinen Arterien und Venen. Arch. f. 
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Brenner, A., Ueber das Verhältniss des N. laryngeus inferior vagi zu einigen 
Aortenvarietäten des Menschen und zu dem Aortensystem der durch Lungen 
athmenden Wirbelthiere überhaupt. Arch. f. Anat. u. Physiol. 1883, pp. 
373-397: 

Brücke, E., Ueber Mechanik des Kreislaufes des Blutes bei Früschen. Wiener 
Sitzungsb. 1851. Vol. VI, p. 61; also p. 114. 

Brücke, E., Beitriige zur vergl. Anatomie u. Physiologie des Gefiasssystems der 
Amphibien. Denkschriften d. Wiener Academie. 1852. Vol. III, p. 335. 
Burdon-Sanderson, J., Circulation of the Blood, in Handb. for the Physiological 

Laboratory. London, 1873. 

Burow, De vasis sanguiferis ranarum. Diss. inaug. Regiomontani, 1834. 

Calori, L., Sugli organi della circulatione e della respirazione dei gyrini della Rana ~ 
esculenta e della Salamandra cristata. Nuov. Ann. delle Scienz. nat. de Bologna. 
1838. 

Champness, F., The Septum Atriorum of the Frog and the Rabbit. Journ. of Anat. 
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Chapmann, S. H., Beitriige zur Kenntniss des Baues des normalen und entziindeten 
Pericardiums der Batrachier. Wiener Med. Jahrbiicher. 


206 THE VASCULAR SYSTEM. 


. Chrzonzezewsky, N., Ueber die feinere Structur der Blutcapillaren. Virchow’s 
Arch. 1866. Vol. XXXYV, p. 169. 

Darwin, F., Contributions to the anatomy of the sympathetic ganglia of the Bladder 
in their relation to the vascular system. Quart. Journ. Micros. Sci. 1874. Vol. 
XIV, p. 100. 

v. Deen, De differentia et nexu inter nervos vitae animalis et vitae organicae. 
Diss. inaugur. Lugduni; also in Arch. f. Anat. u. Physiol. 1834, p. 477. 

v. Deen, Over de zijelingsche Takken dar zwervende van den Proteus anguinis (in- 
cludes frog-larva). Bijdragen tot de Naturkundige Wetenschappen. 1834. 
Dogiel, J., Die Ganglienzellen des Herzens bei verschiedenen Thieren und beim 

Menschen. Arch. f. mik, Anat. 1877. Vol. XIV, p. 471. 

Dogiel, J., Die Nervenzellen und Nerven des Herzventrikels beim Frosche. Arch. 
f. mik. Anat. 1882. Vol. XXI, p. 21. 

Dumeril, A. M.C., and Bibron, G., Erpétologie générale, ou histoire naturelle com- 
plète des reptiles. Paris, 1841. 

Eberth, C. J., Ueber den feineren Bau der Blutcapillaren bei den Wirbelthieren. 
Centralbl. f. d. med. Wiss. 1865, p. 196. 

Eberth, Elemente der quergestreiften Muskelfasern, bes. des Herzens. Virchow’s 
Arch. 1866. Vol. XX XVII, p. 100. 

Ecker, A., Icones physiologicae. Leipzig, 1851-9. 

Engelmann, T. W., Der Bulbus Aortae des Froschherzens. Physiol. Untersuch. in 
Gemeinsch. mit. J. Hartog und J. J. Verhoff. Pfliiger’s Arch. f. d. ges. Physiol. 
1882. Vol. XXIX, pp. 425-468. 

Friedlander, Ueber die nervésen Centralorgane des Froschherzens. Unters. a. d. 
physiol. Labor. in Wiirzburg. 1867. Vol. II, p. 159. 

Fritsch, G., Zur vergleichenden Anatomie der Amphibienherzen. Arch. f. Anat. 
u. Physiol. 1869, p. 654. ; 

Gaskell, W. H., On the auymentor (accelerator) nerves of the heart of cold-blooded 
animals. Journ. of Physiol. 1884. Vol. V, p. 46. 

Gaskell, W. H., and Gadow, On the anatomy of the cardiac nerves in certain cold- 
blooded animals. Journ. of Physiol. 1884. Vol. V, p. 362. 

Gastaldi, Neue Untersuchungen über die Muskulatur des Herzens. Wiirzb, 
Naturf. Zeitschr. 1862. Vol. III, pp. 6-9. 

Gegenbaur, C., Grundzüge der vergleichende Anatomie. 2nd edit., 1870. 

Gerlach, L., Ueber die Nervenendigungen in der Muskulatur des Froschherzens. 
Virchow’s Arch. 1876. Vol. LXVI, pp. 187-223. ~~ 

Golubew, A., Beiträge zur Kenntniss des Baues und der Entwicklungsgeschichte der 
Capillargefiisse des Frosches. Arch. f. mik. Anat. 1869. Vol. V, pp. 49-89. 

Gompertz, C., Ueber Herz und Blutkreislauf bei nackten Amphibien. Arch. f, 
Anat. u. Physiol. Phys. Abt. 1884, p. 242. 

Gruby, Sur le système veineux de la grenouille. Annales des Sciences nat. 2nd 
series. Zool. 1842. Vol. XXVII, p. 207. 

Gruby, Recherches anatomiques sur le système veineux de la grenouille. Paris, 
1842. 

Gscheidlen, R., Zur Lehre v. d. Nervenendigungen in den glatten Muskelfasern. 
Arch. f. mik. Anat. 1877. Vol. XIV, p. 321. 

Heidenhain, Disquisitiones de nervis organisque centralibus cordis. Dissert. inaug. 
Berol., 1854; and in Arch. f. Anat. u. Physiol. 1858, p. 479. 

His, W., Ueber die Endigung der Gefässnerven (in mesentery). Virchow’s Arch. 
1863. Vol. XXVIII, pp. 427-428. 

Hoffmann, C. K., Die Lungengefiisse der Rana temporaria. Dissert. Dorpat, 
1875. 

Hoffmann, C. K., in Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig 
und Heidelberg, 1873-1878. Vol. VI, pp. 509-514. 

Hoffmann, T., Die Lungen-Lymphgefässe der R. temporaria. Dissert. Dorpat, 1875. 


LITERATURE. 207 


Huizinga, D., Untersuchungen über die Innervation der Gefässe in der Schwimmhaut 
des Frosches, Pfliiger’s Arch. f. d. ges. Physiol. 1875. Vol. XI, p. 207. 

Huschke, Ueber die Carotidendriise einiger Amphibien. Zeit. f. Physiol. von 
Friedmann u. Treviranus. 1831. Vol. IV, p. 113. 

Hyrtl, J., Vorläufige Anzeige fiber gefässlose Herzen. Wiener Sitzungsb. 1850. 
Vol. XX XIII, p. 572. 

Hyrtl, J., Ueber die sogenannten Herzvenen der Batrachier. Wiener Sitzungsb. 
1864. Vol. L, Pt. II, p. 42. 

Hyrtl, J., Ueber das Verhalten der Leberarterie zur Pfortader bei Amphibien u. 
Fischen. Wiener Sitzungsb. 1864. Vol. XLIX, Pt. I, p. 167. 

Jantschitz, J., Materialien zur Anatomie der Nerven des Pericardiums. Rudneffs 

_ Journ. f. normale und patholog. Histologie u. klinisch. Med. St. Petersburg, 
1874, pp. 417-442. 

Klug, F., Ueber die Beschleunigungsnerven des Froschherzens. Centralbl. f. d. med. 
Wiss. 1881, p. 945. 

Klug, F., Ueber die Herznerven des Frosches. Arch. f. Anat. u. Entwicklungs- 
gesch. 1881, pp. 330-346. Abstract in Centralbl. f. d. med. Wiss. 1882, 
P- 259. 

v. Kélliker, A., Handbuch der Gewebelehre. 5th edit. 

Küttner, Beitrag zu den Kreïslaufsverhältnissen in der Froschlunge. Virchow’s 
Arch. Vol. LXI, p. 21. 

Lahousse, P., Die Structur des Nervenplexus in der Vorhofscheidewand des 
Froschherzens. Arch. f. Anat. u. Physiol. 1886, pp. 191-196. 

Lambotte, H. A., Observations anatomiques et physiologiques sur les appareils 
sanguins et respiratoires de Batraciens anourés. Mém. cour l’Acad. de Bruxelles. 
1838. 

Langer, C., Ueber das Lymphgefässsystem des Frosches. Wiener Sitzungsb. 1866. 
Vol ii Pt, p395)3-1867.. Mol. LV, Bt. Lp: 503; 1868. Vol. LVIIT, 
Pt. I, p. 198. 

Langerhans, P., Notiz zur Anatomie des Amphibienherzens. Zeit. f. wiss. Zool. 
1972 Vol EXT pa ain 7. 

Langerhans, P., Zur Histologie des Herzens. Virchow’s Arch. 1873. Vol. LVIII, 
pp. 65-83. 

Lavdowsky, M., Das Säugadersystem und die Nerven der Cornea. Arch. f. mik. 
Anat. 1872. Vol. VIII, p. 538. 

Lavdowsky, N., Ueber die Fortsiitze der Nervenzellen in den Herzganglien. Arch. 
f. mik. Anat. 1887. Vol. X XIX, p. 609. 

Lehmann, Ueber die Nervenendigungen und das Vorkommen von mikroskopischen 
Ganglien in den Gefäisswandungen. Zeit. f. wiss. Zool. 1864. Vol. XIV, 
pp. 346-352. 

Levschin, Ueber das Lymph- und Blutgefässsystem, Wiener Sitzungsb. 1870. Vol. 
EXT Pt Lip. 07. 

Leydig, Anatomisch-histologische Untersuchungen über Fische und Amphibien. 1853. 

Leydig, F., Ueber Organe e’nés sechsten Sinnes. Nova Acta Acad. Caes. 1868. 
Vol. XXXIV, pp. I-102. 

Leydig, Lehrbuch der Histologie. 1857. 

Lôwit, M., Beiträge zur Kenntniss der Innervation des Herzens. Pflüger’s Arch. 
f. d. ges. Physiol. Chapters I and II, 1880, Vol. XXIII, p.313. Chapters ITI, 
IV, and V, 1881, Vol. XXV, pp. 399-496. Chapter VI, 1882, Vol. XXVIII, 
p. 312.. Chapter VII, 1882, Vol. XXIX, p. 469. ; 

Lôwit, M., Ueber die Gegenwart von Ganglienzellen im Bulbus aortae des 
Froschherzens. Pfliiger’s Arch. f. d. ges. Physiol. 1883. Vol. XXXI, pp. 
88-94. 

Ludwig, C., Ueber die Herznerven des Frosches, Arch. f. Anat. u. Physiol. 1848, 
p. 139. 


208 THE VASCULAR SYSTEM. 


Marshall, A. M., The Frog. Manchester and London. 1885, pp. 22-31. 

Marshall, C. F., Structure and Distribution of striped and unstriped muscle. Quart. 
Journ. Micros. Sci. 1887. Vol. XXV. 

Meckel, J. F., System der vergleichenden Anatomie. Halle, 1833. 

Milne-Edwards, Lecons sur la Physiol. et l’Anat. comparée. Vol. II, p. 407. 

Namias, M., Suiganglii miocardici della Rana. Osservazione ed esperienzi in Lo 
Spallanzani. 1881. Vol. X, pp. 402-410. 

Nicolsky, P., Ueber Flimmerendothel beim Frosche (in pericardium). Centralbl. f. 
d. med. Wiss. 1880, p. 641. 

Oellacher, J., Ueber die erste Entwickelung des Herzens und der Pericardial- oder 
Herzhohle bei Bufo cinereus. Arch. f. mik. Anat. 1871. Vol. VII, p. 157. 

v. Openchowski, T., Beitrag zur Kenntniss der Nervenendigungen im Herzen. 
Arch. f. mik. Anat. 1883. Vol. XXII, p. 408. 

Owen, R., Comparative Anatomy. Vol. I, p. 517. 

Owen, R., On the structure of the heart in the perennibranchiate Batrachia. 
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Pihlermann, R., Untersuchungen über die angeblich präformirten Verbindungswege 
zwischen den Blut- und Lymphgefiissen des Frosches. Dissert. Dorpat, 1876. 

Pohl-Pincus, Ueber die Muskelfasern des Froschherzens. Arch. f. mik. Anat. 1884. 
Vol. XXIII, p. 500. 

Prévost and Lebert, Mémoire sur la formation des organes de la circulation et du 
sang dans le batraciens. Annales des Sciences nat. 1844; Vol. I, p 193; and 
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Ranvier, L., Lecons d’anatomie générale. Paris, 1880, p. 469. 

Ranvier, L., Appareils nerveux terminaux des muscles de la vie organique; 
cœurs sanguins, cœurs lymphatiques; oesophagus; muscles lisses. Lecons 
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Rawitz, B., Ueber den Bau der Spinalganglien. Arch. f. mik. Anat. Vol. XXI, 
p. 244. 

Reich, M., Eïnige microscopische Studien mit Silbersalpeterlésung besonders an 
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Rokitansky, C. Ueber die Scheidewand der Vorhéfe. Wiener Med. Jahrb. 1871, 
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Rosenberger, De centris iotuum cordis disquisitiones anatomico-physiologicae. 
Dorpat, 1850. 

Rouget, C., Mémoire sur le développement, la structure et les propriétés physiolo- 
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pathologique. 1873, pp. 662-664. 

Rusconi, M., Observations sur le système veineux de la grenouille. Annales des 
Sciences nat. 2nd series. Zool. 1845. Vol. IV, p. 283. 

Sabatier, Etudes sur le cœur dans la série des vertébrés. Montpellier, 1873; 
also Ann. Sci. nat. 1873, Vol. XVIII, art. 4; also Revue Cours. Scient. 1873, 
pp. 163-165. 

Schmuziger, F., Ein Beitrag zur Auswanderung der Blutkérperchen aus den 
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Schôbl, D.J., Ueber die Blutgefässe des cerebrospinalen Nervensystems der Urodelen. 
Arch. f. mik. Anat. 1882. Vol. XX, p. 87. Also in Sitzungsb. d. k. b. Gesell. 

d. Wiss, in Prag. 1878, p. 25. 

Schôbl, D. J., Ueber Wundernetze und divertikelbildende Capillaren bei nackten 
LÉ US ete. Arch. f. mik. Anat. 1885. Vol. XXV, p. 89. 

Schraeder, M. E. G., Ueber das Hemmungscentrum des Froschherzens. Strassburg, 
1886. 

Schutz, C. H., Das System der Circulation. Stuttgart and Tübingen, 1836- 


LITERATURE. 209 


Schweigger-Seidel, Das Herz, in Stricker’s Handbuch d. Gewebelehre. 

Sokoloff, Ueber die Saftkanälchen (Lymphkanälchen) in den quergestreiften 
Muskeln des Frosches. Rudneffs Journ. f. normal u. patholog. Histologie ind 
Klin. Med. St. Petersburg, 1873, pp. 456-459. 

Stirling, W., and Macdonald, The minute structure of the palatine nerves of the 
Frog and the termination of nerves in blood-vessels and glands. Journ. of 
Anat. and Physiol. 1884. Vol. XVII, p. 273. 

Stricker, S., Untersuchungen über die capillaren Blutgefässe in der Nickhaut des 
Frosches. Wiener Sitzungsb. 1865. Vol. LI, Pt. IT, pp. 16-26. 2 
Stricker, S., Studien über den Bau und das Leben der capillaren Blutgefässe. Wiener 

Sitzungsb. 1866, Vol. LII, Pt. II, pp. 379-394. 

Trevianus, G. R., Ueber die Karotidendriise einiger Amphibien. Tiedemann’s 
Zeitschr. 1831. Vol. IV, p. 113. 

Trevianus, C. R., Beobachtungen aus der Zootomie u. Physiologie, nach dessen Tode 
herausgegeben von L. C. Treviranus. Bremen, 1839. 

Verhoeff, J. J. W., Histologische en physiologische bijdragen tot de kennis van den 
bulbus aortae van het kikvorschhart. Onderzoekingen gedach in het Phys. La- 
borat. VII, aflev 2. Utrecht, 1882. 

Vignal, Recherches sur l’appareil ganglion nerve du cœur des vertébrés. Labratoire 
d’histologie du Collége de France. Travaux de l’année 1881, p. 186 ; and in Arch. 
de Physiol. norm. et path. 1881, pp. 673-694 and 910-034. 

Virchow, H., Ueber die Kopfgefässe des Frosches. Sitzungsb. Würzburg, 1880. 
Vol. XV, p. xxxiv. 

Virchow, H., Ueber die Gefiisse im Auge und die Umgebung des Auges beim 
Frosche. Zeit. f. wiss. Zool. 1881. Vol. XXXV, p. 247. 

Volkmann, Nacl:weise der Nervencentra, von welchen die Bewegung der Lyniph- 
und Blutgefässherzen ausgeht. Arch. f. Anat. u. Physiol. 1844, p. 410. 

Wagner, R., Lehrbuch d. vergleichenden Anatomie. Leipzig, 1834-35. 

Wagner, R., [Icones Zootomicae. Leipzig, 1841. 

Weismann, Ueber die Muskulatur des Herzens beim Menschen und in dem 
Thierreiche. Arch. f. Anat. u. Physiol. 1861, p. 42. 

Wyman, J., On the heart and respiration of the Menobranchus and Batrachians. 
Proc, of the Boston Soc. of Nat. History. 1856. Vol. V, p. 51. 

Zimmermann, W., Ueber circumvasale Saftriume der Glaskürpergefässe von Rana 
esculenta. Arch. f. mik. Anat. 1856. Vol. XX VII, p. 410. 


THE LYMPHATIC SYSTEM. 


Bacculo, B., Nuove ricerche intorno l’apparecchio ganglionare intrinsico dei cuori 
linfatici. Naples, 1885. 

Eckhard, C., Zeitsch. f. rat. Med. 1850. Vol. IX. 

Eckhard, C., Beitriige zur Anat. u. Physiol. 1855, Vol. I, p. 53; 1858, Vol. IT, 
p- 145; 1863, Vol. III, p. 167. 

Eckhard, C., Experimentale Physiologie des Nervensystems. Giessen, 1867, p. 208. 

Goltz, Centralbl. f. med. Wiss. 1863, pp. 17, 497; 1864, p. 690. 

Heidenhain, Disquisitiones de nervis cordis cordiumque lymphaticorum. Berlin, 
1854. - 

His, W., Ueber die Wurzeln der Lymphgefässe in den Häuten des Korpers und über 
die Theorien der Lymphbildung. Zeit. f. wiss. Zool. 1863. Vol. XII, p. 223. 

Hoffmann, T., Die Lungen-Lymphgefässe der R. temporaria, Dissert. Dorpat, 
1875. 

Hüter, C., Ueber den Kreislauf und die Kreislaufsstérungen in der Froschlunge. 
Centralb. f. med. Wiss. 1873, Nos. 5 and 6. 

P 


210 THE VASCULAR SYSTEM. 


Jourdain, S., Sur les sacs sous-cutanés et les sinus lymphatiques de la région 
céphalique dans la Rana temporaria. Compt. rend. 1881. Vol. XCIII, pp. 
597-600. 

Jourdain, S., Sur le système lymphatique des tétards de grenouilles. Compt. rend. 
1883. Vol. XCVI, pp. 271-273. ; 

Jourdain, S., Recherches sur le système lymphatique de la R. temporaria. 
Montpellier, 1883 ; Extr. de la Revue de Sci. nat. Montpellier, £884. 

Kahrhel, G., Studien iiber Innervation der Lymphherzen. Medic. Jahrb. 1886, 
PP 53925420: 

Key and Retzius, Studien in der Anatomie des Nervensystems. Arch. f. mik. Anat. 
1873. . Vol. IX, p. 308. 

Klein, E., On the lymphatic system of the skin and mucous membranes. Quart. 
Journ. Micros. Sci. 1881. Vol. XX, pp. 379-406. 

Langendorff, O., and Boll, F., Zur Kenntniss der Lymphherzen. Arch. f. Anat. u. 
Physiol. 1883, p. 329. 

Langer, C., Ueber das Lymphgefiisssystem des Frosches. Wiener Sitzungsb. 1866, 
Vol. LIII, Pt. I, p. 395; 1867, Vol. LV, Pt. I, p. 593; 1868, Vol. LVIII, Pt. I, 
p- 198. 

Levschin, Ueber das Lymph- und Blutgefiisssystem. Wiener Sitzungsb. 1870. Vol. 
LXI, Pt. I, p. 67. 

Luchsinger, B., Zur Lehre der Innervation der Lymphherzen. Pfliiger’s Arch. f. a. 
ges. Pick 1880. Vol. XXIII, p. 304. 

Meyer, J., Systema amphibiorum non Diss. Berol., 1845. 

Müller, J., Beiträge zur Anatomie und Naturgeschichte der Amphibien. Tiedemann’s 
Zeitschr. 1831. Vol. IV, pp. 190-275. 

Müller, J., On the existence of four distinct hearts having regular pulsations con- 
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1833. Pt.I, pp. 89; also in Arch. f. Anat. u. Physiol. 1834, p. 296. 

Müller, J., Bemerkungen über die Structur der Lymphherzen und der Lymphgefasse: 
Arch. f. Anat. u. Physiol. 1839, p. 176. 

Obersteiner, H., Ueber einige Lymphriiume im Gehirne. Wiener Sitzungsb. 1870. 
Vol. LXI, Pt. I, p. 57. 

Pagliani, Ueber die Funktion der Herzganglien. Moleschott’s Untersuchungen. 
1876. Vol. XI, p. 358. 

Panizza, B., Sopra il sistema linfatico dei retelli. Ricerche Zootomiche. Pavia, 


1833. 
Panizza, B., Ueber die Lymphherzen der Amphibien. Arch. f. Anat. u. Physiol. 
1834, p. 300. 


Pihlermann, R., Untersuchungen über die angeblich präformirten Verbindungswege 
zwischen den Blut- und Lymphgefiissen des Frosches. Dissert. Dorpat, 1876. 

Priestly, J., An account of the anatomy and physiology of the batrachian lymph- 
hearts. Journ. of Physiol. 1878. Vol. I, p. 1. 

Ranvier, L., Appareils nerveux terminaux des muscles de la vie organique; cœurs 
sanguins, cœurs lymphatiques ; cesophagus ; muscles lisses. Leçons d’Anatomie 
générale faites au Collége de France. Paris, 1880. Vol. VII, p. 350. 

v. Recklinghausen, Die Lymphgefässe und ihre Beziehung zum Bindegewebe. 
1862. 

Remak, R., Ueber blutlehre Gefässe (Lymphgefiisse) im Schwanze der Froschlarve. 
Arch. f. Anat. u. Physiol. 1849, p. 102. 

Robinson, C., Ueber die Lymphgefässe der Abdominaleingeweide der Früsche, 
sowie deren Lymphbehilter. Froriep’s Notizen, 1846. No. 807, col. 225. 

Rusconi, M., Lettre du docteur Rusconi à M. Breschet sur le système lymphatique 
de la Salamandra commune, Arch. f. Anat. u. Physiol. 1840, p. 8. 

Rusconi, M., Ueber die Lymphgefässe der Amphibien. Arch. f. Anat. u. Physiol. 


1843, p. 241. 


LITERATURE. 211 


Rusconi, M., Einige historische Notizen die Lymphgefässe der Amphibien betreffend. 
Arch. f. Anat. u. Physiol. 1843, p. 244. 

Rusconi, M., Sur les vaisseaux lymphatiques. Annales des Sci. nat. Series II. Zool. 
1841. Vol. XV, p. 249. 

Rusconi, M., Riflessioni sopra il sistema linfatico dei Rettili. Pavia, 1845. 

Scherkey, M: L., Ueber die Feststellung und Bedeutung der Centren der Lymph- 
herzen im Riickenmark. Dissert. Berlin, 1878. 

Scherkey, M. L., Zur Lehre der Innervation der Lymphherzen. Arch. f. Anat. u. 
Physiol. 1879, p. 227. 

Schweigger-Seidel, F., and Dogiel, J., Ueber die Peritonealhôhle bei Fréschen 
und ihren Zusammenhang mit dem Lymphgefässsysteme. Arbeiten aus d. 
physiol. Anstalt. Leipzig, 1867, pp. 68-76; Abstract in Centralbl. f. d. med. 
Wiss. 1867, p. 287. 

Suslowa, N., Beiträge zur Physiologie der Lymphherzen. Centralbl. f. d. med. Wiss. 
1867, p. 832. 

Suslowa, Beiträge zur Physiol. der Lymphherzen. Dissert. Zürich, 1867; also in 
Zeïtsch. f. rat. Med. 3rd series. 1868. Vol. XXXI, p. 224. 

Waldeyer, W., Anatomische und physiologische Untersuchungen iiber die Lymph- 
herzen der Früsche. Zeitsch. f. rat. Med. 3rd series. 1864. Vol. XXI, 
pp. 103-124; Abstract in Centralbl. f. d. med. Wiss. 1864, p. 73. 

Waldeyer, W., Zur Anatomie und Physiologie der Lymphherzen von Rana und 
Emys europea. Studien des physiol. Instituts zu Breslau. 1865, pp. 71-96; 
Abstract in Centralbl. f. d. med. Wiss. 1865, p. 321. 

Weber, E. H., Ueber die Lymphherzen der Amphibien von Panizza. Arch. f. 
Anat. u. Physiol. 1834, pp. 300-304. 

Weber, J., Beitriige zur Anatomie und Physiologie. Bonn, 1832. 


THE BLOOD AND LYMPH. 


Aly, W., Ueber die Vermehrung der rothen Blutkürperchen bei Amphibien. 
Dissert. Halle, 1884. 

Arndt, R., Beobachtungen an roten Blutkürperchen der Wirbelthiere. Virchow’s 
Arch. Vol. LX XVIII, p. 1. 

Beale, L. S., Observations upon the nature of the red blood-corpuscle. Quart. 
Journ. Micros. Sci. 1864, pp. 32-43. 

Bizzozero, G., Ueber die Teilung der roten Blutkürperchen. Centralbl. f. d. med. 
Wiss. 1881, p. 129. 

Bizzozero, G., Ueber die Teilung der roten Blutkérperchen. Centralbl. f. d. med. 
Wiss. 1882, p. 577. 

Bizzozero, G., and Torre, A. A., Ueber die Entstehung der roten Blutkôrperchen 
bei den verschiedenen Wirbelthierklassen. Virchow’s Arch. 1884. Vol. XCV, 
pp. 1-25. 

Brücke, E., Ueber den Bau der rothen Blutkérperchen. Wiener Sitzungsb. 1867. 
Vol. LVI, Pt. II, pp. 79-91. 

Donders and Moleschott, Holländische Beiträge. 1848, p. 361. 

Eberth, C. J., Ueber die Vermehrung der rothen Blutkürperchen nach Unter- 
suchungen von W. Aly. Fortschritte d. Med. 1885. Vol. III, pp. 1-7. 

Fuchs, E., Beitrag zur Kenntniss des Froschblutes und der Froschlymphe. 
Virchow’s Arch. 1877. Vol. LXXI, p. 78. 

Gaule, J., Beobachtungen der farblosen Elemente des Froschblutes. Arch. f. Anat. 
u. Physiol. 1880, pp. 375-392. 


P 2 


212 THE VASCULAR SYSTEM. 


Gulliver, G., Measurements of the red blood-corpuscles of Batrachians. Proc. 
Zool. Soc. London, 1873, p. 162. 

Hewson, W., On the figure and composition of the red Particles of the Blood, com- 
monly called Globules. Phil. Trans. 1773. Vol. LXIII, Pt. I, p. 303. 

Home, E., On the changes the blood undergoes in the act of coagulation. Phil. 
Trans. 1818, p. 172. 

Kollmann, J., Bau der rothen Blutkôrperchen. Zeitschr. f. wiss. Zool. 1874. Vol. 
XXIII, p. 462. 

Kusnezoff, F., Ueber blutkérperhaltige Zellen der Milz. Wiener Sitzungsb. 1873. 
Vol. LXVII, Pt. ITI, pp. 58-67. . 

Moriggia, A., Ueber den Durchtritt der farblosen Blutkérperchen durch die Blut- 
gefasswandungen, etc. Moleschott’s Untersuchungen. 1876. Vol. XI, p. 470. 

Neumann, E., Zur Histologie der rothen Blutkérperchen. Centralbl. f. d. med. 
Wiss. 1865, p. 481. 

Owsjannikow, P., Zur Histologie der Blutkérperchen. Bullet. de l’acad. science 
de Pétersbourg. 1865. Vol. VIII, pp. 561-572. 

Peremeschko, Ueber die Theilung der rothen Blutkürperchen bei Amphibien. 
Centralbl. f. d. med. Wiss. 1879, pp. 673-675. 

Ranvier, L., Traité technique d’histologie, pp. 148-224. 

Rollett, A. Versuche und Beobachtungen am Blute. Wiener Sitzungsb. Vol. 
XLVI, Pt. IL, pp. 65-08. 

Stricker, Beobachtungen iiber die Entstehung des Zellkernes. Wiener Sitzungsb. 
1878. Vol. LXXVI, Pt. III p. 7. 

Thoma, R., Die Ueberwanderung farbloser Blutkürperchen von dem Blut in das 
Lymphgefässsystem. Heidelberg, 1873. 

Welcker, H., Grüsse, Zahl, Volum, Oberfläche und Farbe der Blutkorperchen bei 
Menschen und Thieren. Henle u. Pfeuffer’s Zeitschr. 1864. Vol. XX, 


pp. 258-307. 


. 


PART T: 


THE HEART AND BLOOD-VESSELS. 


PJ BEART: 


(The original arrangement of this section has been modified.) 


Tue heart is situated in the middle line above the central portion 
of the shoulder-girdle and JM. stef*nohyoideus, and below the 
oesophagus; the apex is directed backwards and lies between the 
lobes of the liver, the base is directed forwards and lies a short 
The heart is surrounded by the 


distance behind the larynx. 


pericardium. 


A. The Pericardium [is a 
very thin membranous sac, 
which completely encloses the 
heart ; it is attached, at some 
distance, to the large vessels 
passing to and from the heart, 
and has inserted into it some 
fibres of the MW. obliquus ab- 
dominis internus (see page 70). 
A fold of the pericardium 
extends from the dorsal sur- 
face to the truncus arteriosus, 
and through it courses the 
vena cardiaca. 

The pericardium is a con- 
nective-tissue membrane, and 
is lined on either side with 
endothelium, which is in part 
ciliated (Leydig); the endo- 
thelium of the inner surface 
is continued on to the heart 


Fig. 132. 


el) 
The heart and blood-vessels, seen from the ventral 
surface ; after Howes. 


Left anterior caval vein. 
Carotid arch. 

Left auricle. 

Right pulmo-cutaneous arch. 
Right auricle. 

Left systemic arch. 

Truncus arteriosus, 
Ventricle. 


214 THE VASCULAR SYSTEM. 


and so forms a closed lymph-sac. The pericardium is more or less 
pigmented, and contains both vessels and nerves ; it may contain 
fat-cells]. 


B. The Heart. 


[The heart is a hollow muscular organ, composed of: (1) two 
auricles, forming the wider anterior portion ; (2).the ventricle, placed 
behind the auricles ; (3) the sinus venosus, situated dorsally; and (4) 
the truncus arteriosus, lying ventrally. Examined while still living, 
the auricles are seen to be much darker in colour than the ventricle, 
due to the blood being seen through their thinner walls; between 
the auricles and the ventricle is a distinct groove, the auriculo- 
ventricular groove. The whole organ is more or less pigmented, 
especially the ventricle (R. temporaria has much less pigment). | 


Big. 133. a. The Sinus venosus 
(Sinus venarum cavarum), (Fig. 
133 SV.) is a thin-walled sac 
lying on the dorsal surface 
of the heart, and very shghtly 
to the right side (Hoffmann). 
It is somewhat triangular in 
form, receiving an anterior 
caval vein at each anterior 
angle (V.), and the posterior 
caval vein (/C.) at the poste- 
riorangle. The ventral wall 
has a transverse opening (SV”.), 
by which it communicates with 
the right auricle ; the opening 


or 
The heart, seen from above, and dissected to show the POSSESSES two valves , al ante- 


opening from the Sinus vencsus to the right auricle ; ri or and a po st eri or, an d i s 
after Howes. 


C’, Right carotid arch. placed close to the auricular 


IC.  Posterior caval vein, 
LA, Left auricle. 8 eptum. 
P’, Right pulmo-cutaneous arch. : 
PV. Pulmonary vein. b. The auricles [are not 
RA, Right auricle. 
S’. Right systemic arch. alway S separated, as the sep- 
BF RENE yenoens. tum which usually brings about 
SV’. Opening of Sinus venosus into the right 4 Re 

auricle. the separation 1s 1n some Cases 
CR 2 tlie ial incomplete, and in rare in- 


stances appears to be absent (Hoffmann)]; according to Ecker, the 
auricular septum is sometimes placed so far to the left side that it 


THE 


appears to be absent (Fig. 135). 
The septum is attached to the 
walls of the auricles so as to 
form two distinct cavities, which 
communicate at the auriculo- 
ventricular opening, where the 
septum has a free concave 
border (Fig. 134). The right 
auricle is much larger than the 
left, and receives the systemic 
venous blood from the sinus 
venosus by the opening (Figs. 
133 and 134 SV.) already de- 
scribed. The left auricle re- 
ceives the blood from the lung's 
by the pulmonary vein (Fig. 
133 PV.), which opens into the 
auricle near the septum (Fig. 
134 PY.): [the openings from 
the sinus venosus and from 
the pulmonary vein may be so 
closely approximated as to be 
separated by the septum only. 
The septum is much thinner 
than the auricular walls]. Both 
auricles open into the ventricle 
by the auriculo-ventricular open- 


ing (Fig. 134). 


HEART. ZL5 


The frog’s heart seen from the ventral surface, and 
dissected so as to show its structure. The ven- 
tral walls of the truncus arteriosus and of the 
auricles and ventricle have been removed, From 
a drawing by Mr. Hurst. 


A, Auriculo-ventricular aperture and valve. 

B. Aperture leading from ventricle to truncus 
arteriosus. 

C. Left carotid arch. 

LA. Left auricle, 

P. Left pulmo-cutaneous arch. 

P’. Style passed down right pulmo-cutaneous arch 
into the truncus arteriosus, 7. 

PV. Opening of pulmonary vein, 

RA, Right auricle. 

S. Left systemic arch. 

SA. Septum atriorum, 

SV. Opening of Sinus venosus into right auricle. 

V. Ventricle. 


c. The ventricle (Figs. 132, 134, and 136 /.), examined while 
still living, is seen to be bluntly conical in Fig. 135. 


shape and darker on the left side than on the 
right; this is due to the ventricular wall of 
the right side, near the truncus arteriosus, being 
somewhat thinner. The inner wall is not smooth 
but possesses muscular ridges (Zrabecu/ae). At 


its base the ventricle communicates with the pissection of a case in 


auricles by the auriculo-ventricular opening 


which the auricular - 
septum is placed more 


(Figs. 134 and 136), and with the truncus the left than is nor- 


arteriosus by a separate opening (Fig. 134 À.). 


mal, 
S Septum. 


The ventricle is lined by a layer of endocardial gg Left auricle. 


endothelium. 


V Opening into the 
Sinus venosus. 


216 THE VASCULAR SYSTEM. 


The auriculo-ventricular opening (Fig. 134 4.) is a large 
aperture guarded by two valves, a dorsal and a ventral: each valve 


Fig. 136. . 1s formed by a redupli- 
; LA: cation of the endothe- 
AC. ane / ST lium, and contains a 


small amount of con- 


MG 2 fs 3 
 — nective-tissue; its free 
HAVE is ; margin is bound down 
RASS : ; by a number (about 
twelve) of fibrous cords, 
the chordae tendineae, 
which are attached by 
jt \ their posterior extre- 
TA. 4 V. mities to the trabe- 
Dissection of the heart from the left side ; after Howes. culae. 
A,  Auriculo-ventricular opening. d. The truncus ar- 
AC, Anterior caval veins. is 5 , 
IC. Posterior caval vein, teriosus(Figs. 132 74. 
LA, Left auricle. j nes 
‘PV. Pulmonary vein. 134 A.) arises at the 
RA, Right auricle. base of the ventricle, 
SV. Sinus venosus. À 4 
TA. Truncus arteriosus. on the right side of 


V.  Ventricle, ; 
ao adh its ventral surface, then 


passes forwards and to the left, across the auricles, to reach their 
anterior border near the median line, where it divides to form two 
vessels. 

Internally it is incompletely divided into two compartments by 
a spiral valve (Fig. 134); the valve is attached to the dorsal surface 
and is free ventrally : when the vessel is fully dilated (artificially), 
the valve extends two-thirds of its diameter. The opening of the 
vessel into the ventricle is guarded by two semilunar valves (Fig. 
134 A.), the free margins of which are bound to the inner surface 
of the tube by chordae tendineae. ‘The distal extremity has a semi- 
lunar valve in the left compartment (Fig. 134), which is attached 
by a delicate band to the spiral valve (Ecker). 


C. The minute structure of the Heart. 


[The heart consists chiefly of muscle, but possesses also nerve- 
fibres, nerve-cells, endothelium, and connective-tissue ; the truncus 
arteriosus has in addition, blood-vessels. 


a. The muscular structure of the heart. 


(1) The arrangement of the muscle-fibres varies in the different 
portions of the heart. That of the ventricle will be easily understood 


THE HEART. 217 


by reference to Fig. 137. A layer of circular fibres (CJ/) extends 


round the whole ventricle, and from it more or less radial or trans- 


I. Transverse section through the junction of the hinder and middle thirds of the ventricle of R. tem- 
poraria. II, Transverse section through junction of middle and anterior thirds of the same heart. 
Occ. I, Syst. 1, Leitz. The heart was freely distended 1 with dilute spirit, and so hardened.—G, H. 


‘ CC Central cavity. 
CM  Circular muscle. 
LM  Longitudinal muscle. 
TM Transverse muscle. 


verse bands (717, also Fig. 138 717) pass inwards ; these, in the apical 
portion of the ventricle, seem to extend almost transversely across ; 
towards the base they are directed onwards and forwards towards 
the auricles. Of these bands some, near the apex, can be traced 
directly to the opposite side, others join the wall more anteriorly, 
and still others join bands of muscular fibres (Z1/), which may be 
described as longitudinal, and form the Museuli papillares. In the 
anterior portion of the ventricle the same arrangement holds good, 
but is modified to form a central cavity; still more anteriorly, 
at the junction of auricles and ventricle, the trabecular structure is 
much less apparent, the fibres being closer and mainly circular. 

In the auricles the muscular fibres are chiefly arranged in circular 
rings which cross one another; on the inner surface, however, 
traces of an arrangement similar to that in the ventricle may be 
made out. In the heart, from which the sections in Fig. 137 


1 The base of the ventricle measured, when distended, 8 mm. by 5 mm. 


218 THE VASCULAR SYSTEM. 


were drawn, transverse bands (cut longitudinally), 0°33 mm. in 
length, were numerous ; their central ends terminated in bands, the 
fibres of which were cut transversely. The auricular septum (Fig. 
141 a I)also possesses muscular fibres which cross one another in its 
substance. 

The fibres of the truncus arteriosus resemble those of an ordi- 
nary artery; those of the sinus venosus are arranged in rings, 
mostly transverse, but others oblique, and a few longitudinal. | 


(2) The structure of the cardiac muscle-fibres (Figs. 138 and 
141 à). 

[The cardiac muscle of the frog consists of spindle-shaped cells, 
which as Pohl-Pincus pointed out, are of two kinds ; the main differ- 
ence between the two being in the size of the nucleus, which is 
much broader in one than in the other. 


Fig. 138. 


(fs a! 
if Ma LAN 
UPS \ 
OT CAN 
Portion of a transverse section through the middle of the ventricle of R. temporaria, . From 
same heart as the sections in Fig. 136. Oc. I, Syst, 7, Leitz.—G. H. 


A Rod-shaped nuclei of muscle fibre. 
B Oval nuclei of muscle fibre. 

CM Circular layer of muscle, 

CT  Connective-tissue, 

E Endothelium of the epicardium, 
TM  Transverse bands.of muscle, 


a. Cells with a broad nucleus (Fig. 138 B): the nucleus is lenti- 
cular or egg-shaped, 4 to 7 y broad, 8 to 14 or 18 p long; the 
ratio of length to breadth being I : 2. 

g. Cells with a narrow nucleus (Fig. 138 4): the nucleus is 


THE HEART. 219 


rod-shaped, 2°5 to 3°5 » broad and 25 to 43 u in length. The 
ratio of length to breadth varying from 1:8 to 1:16. These 
cells are more frequent in the right half of the base of the ven- 
tricle than the former variety. In the trabeculae the second 
variety is more numerous (Pohl-Pincus). 

The muscle-fibre may be simple (Fig. 141 a J/) or possess branches 
(Fig. 138); the fibres are all more or less spindle-shaped, and 
striated transversely and longitudinally, but possess no sarcolemma. 
The protoplasmic contents of the cell are finely granular; the 
nucleus much more coarsely granular and possessing one or more 
distinctly marked nucleoli. The striations are due to the presence 
of a network, which has been carefully described by Messrs. B. Mel- 
land and C. F. Marshall!, and is similar to that of ordinary 
voluntary muscle (see histology of muscle). | 

b. The nerves of the heart. 

The nervous supply of the, heart is derived from the sympathetic 
system and from the cardiac branches of the pneumogastric nerve ; 
the course of which has already 
been traced (page 175) to the roots 
of the anterior caval veins, where 
they form a simple plexus by means 
of a connecting link (Fig. 139). 
The plexus possesses nerve-cells and 
sends off two nerves into the auri- 
cular septum ; the one (4) lies dor- 
sally and is shorter and thicker than 
the other (v), which hes ventrally 
in the septum. They course back- 
wards to the posterior border of 
the septum, and there distribute 
fine branches to the base of the 
ventricle and surrounding parts. 


[In the whole of their course in 
the heart they have numerous 
nerve-cells, either imbedded be- Course of the cardiac nerves in the auricular 

é tum. 

tween their fibres or attached to Mu 
Z d Dorsal nerve. 
the nerves and their branches. v Ventral nerve, 

The nerve-fibres are both me- 
dullated and non-medullated. The nerve-cells (Figs. 139, 140, 141) 


* I have had opportunity of examining Mr. Marshall’s slides and have convinced 
myself of the correctness of his observations. 


220 THE VASCULAR SYSTEM. 


are usually oval, and are unipolar or rarely bipolar; sometimes two 
cells exist in the same envelope, forming the ‘twin-cells ? of 
Dogiel (Fig. 141b II). Accord- 
ing to the recent observations 
of Lavdowsky and Dogiel each 
cell receives one medullated fibre 
and gives off a fine non-medul- 
lated fibre ; the two run together 
for a short distance, after which 
the non-medullated fibre sepa- 
rates to supply muscle-fibres. 
Two large clusters of nerve- 
cells have received special names. 


Fig. 140. 


Remak’s ganglion is a large 
group of nerve-cells in the wall 
of the sinus venosus. 


Bidder’s ganglion is formed, 
collectively, by groups of cells in 
: the auriculo-ventricular groove, 

Group of nerve-cells on the cardiac nerve, from : 5 
the auricular septum. Stained with picrocar- the chief groups being attached 


mine. Occ. III, Syst. 3, Hartnack ; after Dogiel. to the two cardiac nerves 
F Fibres of the cardiac nerve. 


PLES No nerve-cells have been dis- 
covered behind that portion of the ventricle near the auriculo- 
ventricular groove, nor has a direct connection between the cells 
or their processes with the fibres of the pneumogastric nerve been 
made out. | 

Nerve-fibres have been described as existing in all parts of the 
ventricle and being connected with the muscle-fibres (Openchowsky 
and others); this cannot, as yet, be accepted as proved. 


The truncus arteriosus also possesses nerve-fibres and nerve-cells 
(Pagliani, Lowit, and others), but their arrangement seems to be 
very irregular. Lowit did not succeed in finding the nerve-cells in 
all cases examined ; and Engelmann denies their occurrence.] _ 


e and d. [The endothelium and connective-tissue of the heart. 


The connective-tissue of the heart exists only in very small 
quantity. A fine layer on the outer surface of the ventricle, 
especially towards the auriculo-ventricular groove, can easily be 
seen (Fig. 138 C7’); the various valves, the auricular septum, and 
more particularly the truncus arteriosus, all contain connective- 


THE HEART. DAT À 


tissue. In the latter part the spiral valve is wholly formed of 
this tissue. 


Fig. 141 a. 


Nan 


in 


PE ar PA a) 


per PLANTA 


Small group of nerve-cells from the auricular septum, Stained with picrocarmine and silver 
nitrate, after Dogiel. 


E Endothelium (endocardium), 
G Nerve-cells. 
: M  Muscle-fibres. 
N Nucleus. 
N’ = Nucleolus. 


The whole of the inner surface is lined with endothelium 


Fig. 141 b. 


Isolated nerve-cells from frog’s heart. 


I. Usual form of nerve-cell. Il. ‘Twin-cell.’ 


C Capsule. 
N Nucleus. 
N’ Nucleolus. 
P Process. 


222 


Arteries and veins of the Truncus 
arteriosus of Bufo vulgaris, after 


Hyrtl. 


a 
b 


Arteria bulbi. 
Truncus arteriosus. 


h,i Hepatic portal veins. 


Right and left synangium. 

Vena bulbi anterior. 

Left innominate vein. 

Vena bulbi posterior (V. cardiaca). 
Right auricle. 

Left auricle. 

Ventricle. 


THE VASCULAR SYSTEM. 


(endocardium), which covers the various 
trabeculae ; the external surface of the 
heart is likewise covered with an epi- 
cardial layer of endothelium (Fig. 138 
#). 

e. The blood-supply to the heart. 

With the exception of the ¢runcus 
arteriosus, no part of the heart possesses 
blood-vessels (Hyrtl). [The ¢runcus 
arteriosus (Fig. 142 6) has a rich anas- 
tomosis, which receives its blood by 
the arteria bulbi (a), a branch of the 
carotid arch. Two veins connect this 
anastomosis with the systemic veins, 
and with the hepatic portal veins: the 
former, vena bulbi anterior (v), passes 
over the auricles to open into the left 
innominate vein (vi); the latter, the 
vena bulli posterior (vc) or vena car- 
diaca, as 1t is more usually named, passes 
from the ¢runcus arteriosus in a fold 
of pericardium, and then courses back- 
wards to open into the anterior-abdo- 
minal vein. | 


Il. THE ARTERIES. 


(The original arrangement of this section has been modified.) 


The Zruncus arteriosus divides to form two vessels (Figs. 132, 
134); each of these is divided by two partitions into three com- 
partments, which after a short course together separate to form 


arches. 


three distinct vessels, the carotid, systemic, and pulmo-cutaneous 


1. The carotid arch (Canalis carotico-lingualis, Briicke ; Ductus 
caroticus), (Fig. 143 J) is the most anterior of the three arches : it 
winds round the side of the oesophagus as far as the carotid gland, 
where it divides to form two branches ; the right carotid arch gives 
off a small branch to the Zruncus arteriosus, the Arteria bulbi (see 
above). 


THE ARTERIES. 225 


The carotid gland (Fig. 144 c’) is a dilated portion of the vessel. 
The interior contains bands or trabeculae of muscle, which give its 


Fig. 143. 


N 
E 
al 
ug 
3 ic 
ie 
il 
rd 
/ | 
Schema of the arterial system of Rana esculenta. 
A Dorsal aorta, ov  Occipito-vertebral artery, 
e Cutaneous artery. P Pulmonary artery. 
ca Carotid artery. s Subclavian artery. 
d Carotid gland. T Truncus arteriosus. 
ic Iliac arteries. ug Urinogenital arterie 
te External iliac artery. v Vertebral artery, 
wi Internal iliac artery. I Carotid arch. 
J Mesenteric artery. IT Systemic arch. 
¢ Lingual artery. JIT Pulmo-cutaneus arch. 


o Occipital artery. 


224 THE VASCULAR SYSTEM. 


walls a more or less spongy structure; the muscle-fibres are not 
transversely striated (Hoffmann). 

a. The lingual artery (Arteria lingualis, Arteria hyoidea-lingualis, 
Arteria hyoidea), (Figs. 143 7, 144 L) arises by two roots from the 
inner surface of the carotid gland, and courses forwards and in- 
wards, supplying branches to the thyroid gland and the Museuli 
geniohyoidei, to the ventral surface of the hyoïd ; another continues 
forwards on the outer border of the J/. Ayoglossus to supply branches 
to the hyoid and tongue. 

b. The carotid artery (drteria carotis communis), (Figs. 143 ca, 
144 €”) arises by several roots from the outer wall of the carotid 
gland ; and passes over the Musculus petrohyoideus I to the anterior 
end of the oesophagus, round which it courses towards the vertebral 
column, and then runs forwards to the base of the skull. The artery 
then courses forwards, lying immediately above the mucous mem- 
brane and underneath the transverse arm of the parasphenoid, which 
it crosses about midway hetween its back and external end ; [at this 
point the artery gives off two palatine arteries, then ascends in the 
orbit to the origin of the 7. pterygoileus, and divides into two 

Fig. 144. branches, the internal carotid artery and the 
ophthalmic artery]. The branches are :— 

(1) The pharyngeal artery (Arteria pha- 
ryngea ascendens), (Fig. 145 p) which runs 
towards the opening of the Eustachian 
tube, distributes branches to the pharynx, 
and anastomoses with the Arteria pharyn- 
geo-maxillaris of the cutaneous artery, and 


Right carotid gland. 


€ . Carotid arch. 


ec’ Carotid gland. with the Ramus inframaxillaris of the 
ce” Carotid artery. #6 
L Lingual artery. occipital artery. 


(2) [The posterior palatine artery (Arteria palatina posterior, 
Virchow) immediately divides into a number of small twigs to 
supply the mucous membrane of the hinder and outer parts of the 
gums. | 

(3) The anterior palatine artery (Ar/eria palatina anterior, Vir- 
chow ; Arteria palatina, Ecker), (Fig. 145 p’) runs forwards, between 
the Musc. levator bulbi and the mucous membrane, with the Ramus 
palatinus of the trigeminal nerve. [On reaching the palatine 
bone, it curves outwards to the outer anterior angle of the orbit, 
where it gives off a branch backwards along the upper jaw to 
the hinder portion of the orbit.] In its course it supplies twigs 


THE ARTERIES. 2925 


to the surrounding tissues, but chiefly to the mucous membrane 
and Harder’s gland. 


Fig. 145. 


Arterial system of Rana esculenta. 


A  Dorsal aorta. m Mesenteric artery, 

Ad Right systemic arch, M Stomach. 

As Left systemic arch. M’ Spleen. 

¢ (opposite fore-limb) Carotid artery. 0 Ophthalmic artery. 

c (in abdomen) Coeliac artery. p Pharyngeal artery. 

em Cutaneous artery. p’ Anterior palatine artery, 
e Lingual artery. S  Subclavian artery. 

H Heart. I Carotid arch, 

H’ Harderian gland. II Systemic arch. 

L Liver. IIT Pulmo-cutaneous arch, 
Lu Lung. 


(4) The internal carotid artery (Art. cerebralis, Virchow) ; see 
Arteries of Brain, p. 162. 

(5) The ophthalmic artery (Art. ophthalmica), (Fig. 145 0) [is 
larger than the internal carotid artery at this point ; it crosses the 
origins of the MW. rectus externus and of the M. retrahens bulbi and 
reaches the optic nerve; the artery then runs forwards along 
the under surface of this nerve and of the eyeball, lying close to 
the sclerotic coat as far as a little beyond the equator, where it 
pierces the sclerotic coat so obliquely that the choroid coat is only 


Q 


226 THE VASCULAR SYSTEM. 


reached at the ciliary processes. In its course the artery sup- 
plies :— 

a. Muscular branches, given off at the point where the artery 
reaches the eyeball. 

B. Two arteries (AA. ciliares) to the choroid, given off at the 
same point as the foregoing. 

y. Two arteries to the iris. 

6. The Art. hyaloulea, the terminal portion of the ophthalmic 
artery. (For further description of these vessels, see Eye.) ]. 


2. The systemic arch (Duclus aorticus), (Figs. 132, 143, and 
145 11) is the middle arch of the three; it arises from the middle 
canal of the Ductus arteriosus, and winds obliquely round the 
oesophagus between the MM. petrohyoide I and 77 towards the 
vertebral column, which it reaches at about the level of the 
sixth vertebra. The right systemic arch is continued as the 
dorsal aorta, the left arch communicates with it merely by a 
small opening, and is then continued as the coeliaco-mesenteric 
artery. 

Branches of the systemic arch :— 

a. The laryngeal artery (Arteria laryngea), (Fig. 146 /g) arises 
from the inner border of the systemic arch before it reaches the 
oesophagus ; it passes forwards and inwards to be distributed in 
the larynx and pharynx. According to Brücke this artery possesses 
a valve at its point of origin. 


b. The oesophageal arteries (Arteriae 
oesophageae) pass from the upper part of the 
arch to the dorsal surface of the oesophagus. 

c. The occipito-vertebral artery (Ecker), 
(Art. occipito-vertebralis), (Fig. 147 0,v) [arises 
from the systemic arch immediately in 
front of the transverse process of the second 
vertebra, and ascends immediately in contact 
Transverse section vt level of With the body of the first vertebra, which it 


ele, separates from the MM. intertransversarti 

dan, capitis and the sympathetic cord].  Immedi- 

ig Laryngeal artery. ately under the most anterior portion of the 

ey aad oe mo M. longissimus dorsi the artery divides into 

IT Aortic arch. two branches, the vertebral and _ occipital 
arteries :— 


(1) The vertebral artery (Arteria vertebralis or supra-vertebralis 


THE ARTERIES. 227 ) 


(Fig. 147 v) courses backwards lying on the transverse processes of 
the vertebrae and on the J/M. intertransversarii, under cover of the 
M. longissimus dorsi. In this course it is close to the oblique pro- 


Fig. 147. 


Dissection to show the occipito-vertebral and the cutaneous arteries. 


The skin of the back has been divided by a median incision and drawn to either side ; the right arm 
dislocated and removed through the opening in the skin (at A), On the left side the extensor 
muscles of the back have been removed. 


c.m. Cutaneous artery. 

ep. Arteria cutanea pectoris. 

0 Occipital artery. 

s Scapular artery. 

v Vertebral artery. : 
cesses, and may even be partially covered by these; it extends 
beyond the sacrum, and gives off :— 


a. The Rami spinales, which pass through the intervertebral 
foramina to the spinal cord (see Arteries of Spinal Cord, p. 162). 

B. The Rami dorsales ; these supply the muscles of the back and 
send branches to the skin, which accompany the cutaneous branches 
of the spinal nerves through the Saceus /ymphaticus cranio-dorsalis. 


oùz 


228 THE VASCULAR SYSTEM. 


y. The Rami intercostales are distributed in part to the WM. in- 
tertransversarii ; other twigs pass ventrally to the periganglionie 
glands; the longest branches accompany the anterior divisions of 
the spinal nerves to the muscles and skin of the belly (Fig. 14 5). 

{ (2) The occipital artery (Arteria occipitalis), (Figs. 147 and 148 0), 

the anterior branch of the occipito-vertebral artery, pierces the 
M. longissimus dorsi; then courses forwards under cover of the 
Fascia dorsalis and upon the M. temporalis, and divides, behind the 
eyeball [at the anterior border of the MM. temporalis, Virchow], 
into two branches :— 

a. The Ramus orbito-nasalis (Fig. 148 on) accompanies the oph- 
thalmic nerve along the wall of the cranium, and passes through 
the sphenethmoid, with the nasal branch of the ophthalmic nerve, to 
the nose, where it divides into two branches supplying the mucous 
membrane of the nose. In its course through the orbit the artery 
supplies branches to the Harderian gland and neighbourmg parts, 
and anastomoses with the ascending branch of the Arteria palatina. 

B. The Ramus maxillaris communis (Art. temporalis, Virchow), 
(Fig. r48 m) runs downwards and outwards along the anterior 
border of the JZ. temporalis, and passes under the anterior arm of 
the squamosal bone to course backwards on the upper jaw. At 

this point the Ramus maxillaris 

Fig. 148. superior (m’) is given off. The 

TES main artery continues its backward 

QE course to the tympanic membrane, 

where it divides into its three termi- 
nal branches :— 


[(1) The Ramus maxillaris supe- 
rior (AA. maxillares superiores, Vir- 
chow), usually not a single artery 
but a number of small twigs, which 


supply the space between the eye 


Branches of the occipito-vertebral and cuta- and the upper jaw. 
neous arteries in the head ; side view. The 
skin (H) has been reflected downwards. 


(2) A small ascending branch to 


c.m. Cutaneous artery. the tympanic membrane (Virchow). 
la. M. levator scapulae. 


m Art. maxillaris communis. 
Art. maxillaris superior. 


(3) A Ramus auricularis(Virchow), 


sw Art. maxillaris inferior. which forms a rich anastomosis on 
7) Occipital artery. 5 = 
on SC GE hante the hinder wall of the tympanic 


p.m, Art. pharyngo-maxillaris. 


= 5 a] 710 
ill | Here Er cavity, and supplies a twig to the 


tympanic membrane. This passes 


THE ARTERIES. 229 


from the upper border of the membrane to the point of attachment 
of the Columella auris (extrastapedial), round which it forms a 
circular anastomosis. The Ramus auricularis also anastomoses with 
the cutaneous artery. 


Dissection to show the occipito-vertebral and the cutaneous arteries. 
The skin of the back has been divided by a median incision and drawn to either side ; the right arm 
dislocated and removed through the opening in the skin (at 4). On the left side the extensor 
muscles of the back have been removed. 


c.m, Cutaneous artery. 

cp. Arteria cutanea pectoris. 
0 Occipital artery. 

s Scapular artery. 

v Vertebral artery. 


(4) A branch passing inwards to the fat-body, and lying immedi- 
ately in front of the deltoid muscle (Virchow). 

(5) A small branch running on to the inner surface of the angle 
of the jaw and then forwards (Virchow). 


230. THE VASCULAR SYSTEM. 


(6) A larger vessel, the Ramus mawillaris inferior (Fig. 148 m’’), 
which arises from the Ramus maxillaris superior under cover of the 
tympanic membrane, and accompanies the Ramus mandibularis of 
the trigeminal nerve through the 77. masseter, or between this 
muscle and the J/. {emporalis to the mandible, and then courses 
forwards to the chin. A large cutaneous branch is given off half- 
way along the floor of the mouth. The artery gives off many 
small twigs to supply the neighbouring: structures. | 

3. The pulmo-cutaneous arch (Ductus pulmo-cutaneus), Figs. 
132, 143, and 145 ///) is the hindmost (fifth embryonic) of the 
three persistent arches; it passes upwards and forwards on the 
oesophagus, and at the level of the carotid gland divides into two 
branches, the pulmonary artery and the cutaneous artery. 

a. The pulmonary artery (Arteria pulmonalis) runs backwards to 
the root of the lung, along the outer surface of which it is continued 
in a sinuous course. It supplies the lung. 

b. The cutaneous artery (Arteria cutanea magna), (Fig. 149 c.m.) 
| passes along the deeper surface of the A7. petrohyoideus IIT until near 
the prootic bone; in this course it travels forwards. outwards, and 
upwards, crosses the outer border of the muscles, and appears between 
the MW. levator anguli scapulae and the 11. sternocleidomastoideus. At 
this point the artery curves sharply round to reach the angle of the 
jaw, the hinder border of the 17. depressor maxillae inferioris. The 
curve so formed and the descending limb are covered by the 47. 
depressor maxillae inferioris. The artery then passes backwards to 
form a rich anastomosis in the skin almost as far as the posterior 
end of the trunk. It supplies the following branches :— 

(1) The Ramus dorsalis (Virchow) arises immediately in front of 
the curve of the main artery; it ascends behind the J/. femporalis, 
and passes along the anterior border of the 17. depressor maæillae to 
the skin, where it curves backwards. It supplies small twigs 
forwards as far as the eyelids. 

(2) The Ramus auricularis (Virchow) also arises in front of the 
curve in the cutaneous artery; sometimes it arises from the Ramus 
dorsalis. The artery winds around the J. petrohyoideus ITT near its 
insertion, and so reaches the posterior wall of the tympanic cavity, 
where it anastomoses with the 2. auricularis of the Ramus maxillaris 
communis. | 

(3) The Arteria pharyngo-maxillaris (Fig. 148 p.m.) is a small 
branch running forwards and outwards to supply the mucous mem- 
brane of the larynx, Eustachian tubes, gums, the lower jaw, and 


THE ARTERIES. Zak 


the skin under the mouth. It forms a rich anastomosis with 
branches of the Ramus maxillaris inferior of the occipital artery, 
and with others from the pharyngeal branch of the carotid artery ; 
a large branch passes forwards to supply the skin of the throat 
and floor of the mouth. 

(4) The Arteria cutanea pectoris (Fig. 149 c.p.) is distributed to the 
skin of the breast. 


4. The subclavian artery (Arteria subclavia), (Fig. 150 s). 
The subclavian artery arises from the systemic arch immediately 
behind the occipito-vertebral artery at the level of the second or 
third vertebra. The artery then runs outwards alongside and in 
front of the brachial nerve, between the M. subscapularis and the 
M. triceps to the arm, where it is known as the brachial artery ; in 
its course it gives off :— 

a. The Arteria costo-cervicalis (Fig. 150, 1). This artery arises 
near the systemic arch, and runs backwards, parallel to the ver- 
tebral column, over the brachial nerve, and across the transverse 
processes of the vertebrae. It is distributed more especially to the 
M. obliquus internus. 


Fig. 150. 


b. The Arteria 
corace - clavicula- 
ris (Fig. 150, 2) 
arises more ex- ‘Nite sy 


ternally than the —È 
last artery; it ll i 
accompanies the 
coraco -clavicular 
nerve on the dor- 
sal surface of the 
ventral portion 
of the shoulder- = 
girdle, and passes 

between the JZ. 

deltoideus and M. 


subscapularis into 


LD )) 


be 
| 
) 


Subclavian artery of the left side, 


the 7 oramenoval €, A Systemic arch. s  Subclavian artery. 
A’ Dorsal aorta. - U  Ulnar artery. 


where 16 divides € Arteria cutanea medialis superior. 
to su ] th es ce’ Arteria cutanea medialis inferior. 
PP 3 À © ls M. levator scapulae, 


muscles and the o.v Occipito-vertebral artery. 
Ê p Arteria pectoralis. 
M. pectoralis. R Radial artery. 


Arteria costo-cervicalis, 
Arteria coraco-clavicularis. 
Arteria scapularis posterior, 
Arteria scapularis superior, 
Cutaneous artery. 

Arteria subscapularis. 


Auf WN H 


232 THE VASCULAR SYSTEM. 


e. The Art. scapularis posterior (Fig. 150, 3), a small branch 
arising opposite at the tip of the second transverse process and 
passing backwards over the A1. transverso-scapulares, to which it is 
distributed. 

d. The Art. scapularis superior (Fig. 150, 4) accompanies several 
nerves between the MW. subscapularis, M. transverso-scapularis major, 


Fig. 151. Fig. 152. 


=] 


eri 
\ R 
À 
\\\ 
Arteries of the palmar surface of the hand. Arteries of the dorsal surface of the hand. 
B  Ulnar artery. B  Ulnar artery. 
ci R. cutaneus medialis inferior. cri R. cutan. rad. inferior. 
d Digital branches. Kk Radial artery 
F M. flexor digitorum communis. II Thumb. 
JI Thumb. V Fifth finger. 


V Fifth finger. 
and the long head of the J. triceps towards the dorsal surface, 
where it is distributed to the WI. infraspinatus, latissimus dorsi, etc. 
e. The Ramus cutaneus maxillaris. 
f. The Art. subscapularis (Fig. 150, 6) is distributed in the sub- 
scapular muscle. 


A. The brachial artery (Arteria brachialis), (Fig. 150) accom- 
panies the brachial nerve under cover of the long head of the 
M. triceps and over its inner head to the Plica cubiti, into which it 
sinks near the tendon of the MW. sternoradialis ; beyond this point it 
is continued as the ulnar artery. In its course the brachial artery 
gives off :— 

a. The Arteria pectoralis (Fig. 150 p). 

b. The Arteria cutanea medialis superior (Fig. 150 ¢). 

c. The radial artery (Arteria radialis), (Fig. 150 À) which winds 


THE ARTERIES. 239 


round the humerus with the radial nerve between the muscles of the 
outer side of the forearm, to which it gives branches : in the palm 
of the hand it passes between the I. extensor carpi ulnaris and the 
M. flexor antibrachii to the dorsal surface of the hand, where it 
anastomoses with the ulnar artery. In its course 1t supplies :— 

(1) Muscular branches to the surrounding muscles. 

(2) The Ram. cut. radialis inferior, which arises from the radial 
artery towards the distal end of the forearm, and passes underneath 
the MW. flexor carpi ulnaris to the skin. 


B. The ulnar artery (Arteria ulnaris), (Figs. 150 U, 151 B) ac- 
companies the ulnar nerve towards the hand, passes between the 
M. flexor digitorum communis and the M. anconeus to the palm of the 
hand, and then winds round the outer side to the dorsal surface 
of the carpus to form its terminal branches. The branches are :— 

(1) The Ram. cutan. med. inferior (Fig. 151 ci); it arises near 
the wrist-joint and supplies (a) twigs to the skin of the inner sur- 
face ; (8) a branch downwards, which courses along the inner side 
of the second finger to its tip; and (y) a branch which passes 
upwards to anastomose with the ZX. cutaneus medialis superior. 

(2) In the palm of the hand a branch (Fig. 151 d) is given off, 
which divides to form Arteriae digitales volares : one for the second 
finger, two for the third finger, two for the fourth finger, and one 
for the fifth finger. 

(3) Given off on the dorsum of the hand (Fig. 152) it supplies 
branches corresponding exactly with those of the palmar surface. 


5. The dorsal aorta (Aorta communis s. abdominalis (Fig. 153 A). 
The two systemic arches unite at about the level of the sixth vertebra 
to form the dorsal aorta: as already mentioned the union is very 
incomplete, the dorsal aorta being practically a continuation of the 
right systemic arch, and only communicating with the left by 
means of a small opening. The branches are as follows :— 


a. The coeliaco-mesenteric artery (Arteria intestinalis communis), 
(Fig. 153), the true continuation of the left systemic arch, at once 
divides to form the gastric and mesenteric arteries. 

(1) The gastric artery (Arteria gastrica s. coeliaca) (c)immediately — 
divides into two branches :— | 

a. The Ramus dexter s. anterior; this artery gives off the Arteria 
hepatica to the liver and gall-bladder and passes to the right (an- 
terior) surface of the stomach, running along the attachment of the 


234 THE VASCULAR SYSTEM. 


mesentery and supplying branches forwards to the oesophagus and 
backwards towards the intestine. 


B. The Ramus sinister s. posterior passes to the left (posterior) 
surface and behaves like the Ram. dexter. 

(2) The mesenteric artery (Arteria mesenterica superior and infe- 
rior, and the Arteria splenica), (Fig. 153 m) supplies :— 

a. The superior mesenteric artery, which supplies the upper part of 


Arterial system of Kana esculenta. 


A Dorsal aorta. m Mesenteric artery. 

Ad Right systemic arch. M Stomach. 

As Left systemic arch. M' Spleen. 

¢ opposite fore-limb) Carotid artery. 0 Ophthalmic artery. 

c (in abdomen) Coeliac artery. p Pharyngeal artery. 

cm Cutaneous artery. p’ Anterior palatine artery. 
e Lingual artery, S  Subclavian artery. 

H Heart. 14 Carotid arch. 

H’ Harderian gland. II Systemic arch. 

L Liver. III Pulmo-cutaneous arch. 
Lu Lung. 


the intestine, and gives off a recurrent branch to the stomach, which 
anastomoses with the gastric arteries. 


8. The splenic artery to the spleen. 


THE ARTERIES. 295. 


y. The inferior mesenteric artery to the lower part of the intestine. 

All the arteries to the intestine course in lymph-spaces. 

b. The urinogenital arteries (Arteriae urino-genitales), (Fig. 
154 wg) are four to six small arteries arismg from the ventral 
surface of the aorta between the kidneys: they immediately divide 
into right and left branches to supply the kidneys, fat-bodies, 
reproductive organs, and their ducts (see kidney). 

ce. The lumbar arteries (Arteriae lumbales), are small paired vessels 
to the neighbourmg muscles, and send branches through the in- 
tervertebral foramina to the vertebral canal. Sometimes these 
arteries arise from the Art. spinalis or Art. vertebralis, ete. ; in the 
former case they pass outwards from the vertebral canal to the sur- 
rounding: structures. 

d. The haemorrhoidal artery (Art. mesenterica inf. s Art. hae- 
morrhoidalis superior) is a small median artery running from the pos- 
terior end of the aorta to the large intestine. 


6. Bifurcation of the aorta. The 
iliac arteries (Arferiae iliacae commu- 
nes). Opposite the middle of the uro- 
style the aorta bifurcates to form the 
iliac arteries; each of these courses 
on the corresponding sciatic plexus to 
the thigh, beyond which it is con- 
tinued as the sciatic artery. The 
branches of the ihac artery are :— 


a. The vesico-epigastric artery 
(Arteria epigastrico-vesicalis), (Fig. 155 
ev); it arises near the bifurcation, 
passes outwards on the plexus, and 
divides into two branches :— 


The urinogenital arteries, 


LES 


(1) The epigastric artery (Arteria ts Fatah 
epigastrica) (e) immediately gives off Testis. 
te Kidney. 

a recurrent branch to the iliac bone do tie ere) 
and the M. ilio-coccygeus ; it then 
continues to the ventral muscles of the abdominal wall, where it 
runs forwards on the deeper surface of the A7. obliquus internus, and 
is distributed more especially to this muscle. 

(2) The hypogastric artery (Arteria vesicalis) (v) winds downwards 
around the sciatic plexus to reach the mesentery, along which it 


courses to the bladder, where it forms a rich anastomosis. 


a5 


‘236 THE VASCULAR SYSTEM. 


b. The femoral artery (Arteria femoralis s. cruralis), (Fig. 155 f) 
is the representative of the femoral artery of man, although it does 
not perform the same functions. The artery passes under the 
hinder free border of the MW. obliquus internus to the thigh, where it 
lies upon the 47. ilio-psoas, and sends twigs to the neighbouring 
muscles, the skin, and lymph-sac (Lamina inguinalis), and then 
divides into :— 

(1) A twig, which runs forwards on the ventral surface of the 
iliac bone and is covered by the epigastric artery. 

(2) A twig, running forwards and downwards on the IZM. cho- 
psoas, vastus internus, and sartorius, to send branches to the hip-joint. 


c. The spermatic artery (Arteria spermatica), which arises, in 
males, from the iliac artery, and ascends to the Vesicula seminalis. 


7. Arteries of the hinder 
extremity. 


A. The sciatic artery (Ar‘e- 
ria ischiadica), (Fig. 156 à) is the 
continuation of the iliae artery ; 
it leaves the pelvis between the 
hinder (outer) border of the 47. 
coccygeo-iliacus and the inner 
surface of the origin of the 4Z. 
ilio-psoas, then lies between the 
ES former muscle and the origin of 
BN LY, \ e the MW. vastus externus. It ap- 
a À a | \ — pears on the thigh between the 47. 

Yj «| LE vastus externus (in front) and the 
Zw M. pyriformis (behind) ; it is the 
main arterial trunk for the hinder 
Bifureation of the aorta and the iliac arteries, extremity. The artery courses 

eee AE backwards, lying upon the sciatic 


ev Vesico-epigastric artery. 


(LR 


\\\\ 


i 


Nh 


f Femoral artery. nerve and between the I. biceps 
o Internal oblique muscle. ‘ . . 
AR Gotan and the M. semimembranosus ; in 


this course it runs in a lymph- 
space placed in the Septum femorale superius (see page 259). 
Arrived at the popliteal space the artery bifurcates to form the 
peroneal and tibial arteries; near the pelvis it gives off two 
branches (a) and (b), and in its course along the thigh two 
branches (ce) and (d). 


a. The Art. haemorrhoidalis inferior (4) runs backwards and 


a 2 


CC SR NO à à =; 


THE ARTERIES. 2 


inwards under the A7. pyriformis to be distributed in the I. sphincter 
ani and the skin of the anus. 


b. The Art. cutanea femoris posterior v. superior (ef”) runs with the 
corresponding nerve and the MW. pyriformis, and over the 17. semi- 
membranosus to the skin of the imner and hinder surfaces of the 


thigh. 


e. The Rami musculares supply the AM. semimembranosus, the M. 
biceps, and the MAMI. extensores auris; the branch to the A7. rectus 
inferior major pierces the muscle in company with the nerve, and 
is continued as :— 


d. The Art. cutanea femoris media (cf”) to the skin of the middle 
of the inner surface of the thigh. Several small twigs pierce the 
M. rectus internus minor, 
reach the skin, and 
communicate with this 
artery. 


Arteries of the hinder extremity. 


ce Art. cutanea calcanei. 

ef Cutaneous branch of the fe- 
moral artery. 

cf Art. cutanea fem. post. supe- 
rior. 

cf” Art. cutanea femoris media. 

egl Art cut. genu lateralis supe- 
rior, 

eg’ Art. circunmfiexa genu lateralis 
inferior. 

cgm Art. circumflexa genu superior 
medialis, 

com’ Art. circumflexa genu inferior 
medialis, 

ci M. coccygeo-iliacus. 

g M. gastrocnemius. 

gt M. glutaeus. 

h Art, haemorrhoidalis inferior, 

a Sciatic artery. 

mi Art. malleolaris lateralis. 

mm Art. malleolaris medialis, 

p Art. peronea. 

p’ Muscular branch to the M, 
peroneus. 

P  M.pyramidalis, pp 

ra M. rectus anterior. Be all 

vi’ M. rectus internus, W | 

sm M.semimembranosus. i) 


su Art. suralis, tr-------- 1 7 
t Tibial artery. | 
to Aperture in tibio-fibula. r 


tr Art. tarsea. 4 
ve M. vastus externus, 4 


: 
(+0 


LR \ 
<a 


\\ 
\\ 
N 


NaN 


NS N Ÿ 
DO) 


mn 
Cc 


B. The peronéal artery (Art. peronea), (Fig. 156 p) runs out- 


238 THE VASCULAR SYSTEM. 


wards under cover of the tendon of the MW. biceps femoris, and 
accompanies the peroneal nerve downwards to give off :— 


a. The Art. circumfleæa genu lateralis superior, which runs forwards 


on the outer side of the knee, gives a twig to the joint, and is | 


continued as :— 


b. The Art. cutanea genu lateralis superior (cg!) to the skin of the 
anterior and outer sides of the knee. It anastomoses with branches 
of the Arteriae circumfplexae genu mediales to form a rich anastomosis 
(Rete articulare genu): other branches pass upwards to inosculate 
with the Art. cutanea femoris anterior (cf), and others downwards 
to anastomose with the next artery. 


e. The drt. circumflena genu lateralis inferior (cgl’) runs under 
the tendon of origin of the gastrocnemius to the outer side of the 
knee, and terminates in the skin as the Art. cutanea genu lateralis 
inferior. Some of the cutaneous twigs pass upwards to anastomose 
with the Art. cut. genu lat. superior, others downwards to anastomose 
with the 44. malleolares. 


d. A muscular branch (p’) for the J/. peroneus ; it is the real 
continuation of the peroneal artery, and runs behind the outer 
tendon of origin of the gastrocnemius to be distributed in the 
M. peroneus. 


C. The tibial artery (Arteria tilialis), (Fig. 156 t), arises at 
the bifurcation of the sciatic, and runs inwards, meeting the 
tibial nerve between the tendons of origin of the W/. gastrocnemius, 
and deep in the popliteal space under cover of the calf-muscles. It 
then pierces the 97. tibialis posticus, and leaves this to perforate the 
tibio-fibula (see p. 50), appearing again on the anterior surface 
as the anterior tibial artery. Before meeting the tibial nerve this 
artery gives off the following branches :— 


a. The Art. cireumflexa genu superior medialis (cgm), which winds 
round to the front of the knee-jomt, and gives off a cutaneous 
branch, the drt. cutanea genu medialis superior, which is distributed 
in the skin of the inner side of the knee and anastomoses above with 
the Art. cutanea femoris media, below with the following branches 
(b, c, and d). 

b. The Art. circumfleæa genu inferior medialis (cgm’) supplies twigs 
to the knee-jomt, and passes to the skin of the knee and inner 
surface of the calf as the Art. cutanea inferior medialis. 


e. Muscular twigs to the J/. gastrocnemius. 


a a 


THE ARTERIES. 239 


d. The Art. suralis (su); this accompanies the N. suralis down- 
wards along the calf-muscle, and is distributed in the skin of the 
inner side of the heel. 


e. While passing between the fibres of the 7. tibialis posticus, the 
tibial artery gives off muscular twigs ; one larger than the rest is 
known as the Ramus descendens. 


D. The anterior tibial artery (Arferia tibialis antica), (Fig. 
157 ¢.a.) is the continuation of the tibial artery after piercing the 
tibio-fibula. It runs Fig. 157. 
downwards on the 
anterior surface of 
the leg, then between 
the two heads of the 
M. tibialis anticus to 
the dorsum of the 
foot, where it is con- 
tinued as the Arte- 
ria dorsalis pedis. It 
supplies :— 


a. Rami musculares 
to the A], peroneus, 
M. extensor cruris, 
and to the 27. flexor 


tarsi anterior. 


b. The Art. cuta- « 
nea cruris inferior 
(c.c.i.) passes between 
the two heads of the 
M. tihialis anticus to 
the skin of the ante- 


Arteries of the dorsal surface of the foot. 


ror and outer sides ec. Art, cutanea calcanei. 
c.c.i, Art, cutanea cruris inferior. 
of the leg : Ft’ M. flexor tarsi. 
h Art, cutanea hallucis. 
c. The Art. cuta- it Art. interossea dorsalis I, 
n : à : i2 Art. interossea dorsalis IT. 
da calcanei (cc ) a 73 Art. interossea dorsalis ITT. 
given off at the 74 Art. interossea dorsalis IV. 
kl RÉ : ml Art. malleolaris lateralis. 
an e-Joimt 3 it runs mm, Art. malleolaris medialis. 
t.a. Anterior tibial artery. 
outwards ae the ta*  Bifurcation of the dorsalis pedis artery, 
lower end of the tr Art. tarsea. 


tibio-fibula, giving branches to the joint, then backwards between 


240 THE VASCULAR SYSTEM. 


the tibio-fibula and the M/. peroneus to be distributed to the skin 
of the heel. Above it anastomoses with the A. circumflexa genu inf. 
lateralis, and below with the malleolar arteries. 

d. The Art. malleolaris lateralis (ml) arises a little beyond the 
last artery ; it runs outwards under the origin of the J/. flexor tarsa, 
gives branches to the joint and muscles, and terminates in the skin 
of the outer border and dorsal surface of the foot. 

e. The Art. malleolaris medialis (m.m.) arises at about the 
same level as the Art. malleolaris lat. from the inner border of the 
anterior tibial artery. It supplies branches to the joint, gives nu- 
merous branches to the skin, which anastomose with the Arf. suralis, 
and passes to the inner border of the foot, where it ends by dis- 
tributing branches to the 17. plantaris, the extensor aponeurosis, and, 
as the Art. cutanea plantaris, to the skin of the sole of the foot. 


E. The dorsal artery of the foot (Art. dorsalis pedis), (Fig. 
157 ta.) runs under the M. flexor tarsi posterior to the point {a*, 
where it is superficial; the artery then 
bifureates ; the branches are :— 


a. The Art. tarsea (tr) which arises from 
the dorsal artery of the foot while under 
cover of the MW. flexor tarsi posterior ; it 
passes to the J/. extensor digiti V and to 
the skin of the dorsum and outer border 
of the foot. One branch courses along 
the outer border of the fifth toe to its tip ; 
another passes upwards to anastomose 
with the neighbouring: vessels. 


b. The inner branch, formed by the 
bifurcation of the dorsal artery of the 
foot, at once divides to form :— 

(1) The Art. cutanea hallucis (h) to the 
supplemental great toe. 

(2) The Art. interossea dorsalis I (i), 

Arteries of the sole of the foot. which at once bifureates to form two 

à ns i Rami digitales for the first and second toes; 
these inosculate with the drt. cutanea 
plantaris, and send twigs to the skin of the inner border of the foot. 

e. The outer branch formed by the bifurcation of the dorsal 
artery divides to form the Arferiae interossei dorsales IT, LIT, and 7 
(2, 7°, 7); they are distributed in a rich anastomosis to the web. 


THE VEINS. 241 


d. The Arteria interossea (Fig. 158 7) arises from the dorsal 
artery of the foot at the tarsus, and perforates the membrane 
between the astragalus and caleaneum to reach the sole of the foot. 
It forms a rich subcutaneous plexus on the calcar, and anasto- 
moses with the Lami perforantes (Fig. 158 pf), which pass above 
the upper borders of the Musculi interossei to reach the plantar 
surface, where they give off small Rami interossei volares to 
anastomose with the 44. inlerosseae dorsales. 


Ill. THE VEINS. 


(The arrangement of this section has been modified.) 


The blood, distributed to the body by means of the arteries, is 
returned to the heart by the veins, which conduct the blood di- 
rectly or indirectly to the auricles. The pulmonary vein opens 
directly into the left ventricle, the three Venae cavae open into the 
Sinus venosus. 


A. Vein opening into the left auricle. 

The pulmonary vein (Vena pulmonalis communis), (Fig. 159 
vp). The blood returning from each lung is gathered into a 
vessel lying along the inner side of the root of the lung. That of 
the right side is somewhat longer than the left ; the two vessels 
(Wenae pulmonales deatra et sinistra) ran above the corresponding 
anterior caval veins to form a common trunk, the pulmonary vein, 
which opens into the left auricle (see p. 215). 


B. Veins opening into the Sinus venosus. 

The veins opening into the Sinus venosus are the three caval 
veins ; of these the two anterior open into the anterior angles of 
the Sinus venosus, the posterior into the posterior angle. 

1. The Anterior Caval Veins (/ ena cava superior), (Figs. 133 I, 
159 Ca) are a pair of large veins opening into the Sinus venosus 
and returning to it blood from the fore-limbs and sides of the head. 
Each vein is formed by the union of a small vein, the external jugu- 
lar, with two large veins, the innominate and the subclavian veins. 

a. The external jugular vein (Vena jugularis externa), (Fig. 
159 ye) is formed, at the outer border of the hyoid bone, by the 
union of two veins :— 

(1) The lingual vein (Vena lingualis) (Fig. 1617). This originates 
at the tip of the tongue and passes in a very tortuous course along 
the ventral surface of the hyoid; it receives numerous branches 
from the tongue and hyoid muscles. 

R 


242 THE VASCULAR SYSTEM. 


(2) The mandibular vein (Vena maxillaris inferior), (Fig. 161 m) 
runs along the insertion of the I. submaaillaris, and turns inwards 


at its hinder border to join the lingual vein. 


b. The innominate vein (Vera anonyma), (Fig. 160 A) is formed 


m 
1 


by the union of the 
internal jugular and 
the subscapular veins. 
By tracing the inno- 
minate vein upwards 
between the suspenso- 
rium and the shoulder- 
girdle, the internal 
jugular vein will be 
seen to receive the 
vertebral vein at the 
outer border of the 47. 
levator scapulae. The 
left innominate vein 
receives the Vena bulli 
anterior from the Trun- 
cus arteriosus (p. 222). 


Schema of the veins of Rana 
esculenta. 

a Subclavian vein. 

ab, Anterior abdominal vein. 

Ad Right auricle. 

As Left auricle. 

Ca Anterior vena cava. 

Cp Posterior vena cava. 

em Cutaneous vein. 

d Vena dorso-lumbalis. 

D Intestine. 

fi Femoral vein. 

i Sciatic vein. 

ic Vena communicans iliaca, 

je External jugular vein form- 
ed by lingual and maxil- 
lary veins / and m. 


ji Internal jugular vein. 


L  Hepatic veins. 

N Kidney. 

0 Ovidueal veins. 

P  Hepatic portal vein. 

val Renal portal vein. 

rall Secondary renal : portal 


veins. 
ve Renal veins. 
$ Subscapular vein, 


SC S§ nus venosus. 

va Innominate vein. 

ve Vena bulbi posterior (car- 
diac vein 

vp Pulmonary veins, 


THE VEINS. 243 


(1) The internal jugular vein (Vena jugularis), (Fig. 160 J) can 
be traced from the border of the I. /evator scapulae upwards and 
forwards to the hinder part of the prootic bone: it then passes 
forwards under the lateral process of the prootic, in a groove on 
the anterior surface of the same bone, towards the hinder angle of 
the orbit, where it receives the veins from the cranial cavity (see 
vessels of brain, p. 165), and also a branch from the orbit. 


Fig. 160. 


x 


Distribution of the internal jugular vein and the anterior portion of the cutaneous vein. 


Anterior lymph-heart. 
M. levator scapulae. 
M. obliquus internus, 
Vena orbitalis anterior. 


Transverse process of the second vertebra. 
Transverse process of the third vertebra. 
Transverse process of the fourth vertebra. 


A Innominate vein. 0!  Vena orbitalis posterior. 

em, Cutaneous vein. P  Lateral process of the prootic bone. 
ae Nasal vein. S  Subscapular vein. 

h Harderian gland. S’ Shoulder-girdle. 

H Skin, reflected downwards. T Tympanic membrane. 

J Internal jugular vein. V Vertebral vein. 

L 2 

y 3 

0 4 

0 


a. [The Vena orbitalis media (Virchow) ; it arises from the an- 
terior internal angle of the orbit, from the Harderian gland, the 
nasal cavity, or from other veins on the anterior wall of the orbit. 
The vessel lies close to the cranium, immediately underneath the 
Arieria nasalis, and sinks under the MW. rectus superior to join the 
internal jugular vein. It its course it receives the Vena bulhi supe- 
rior (see eye), and near its termination communicates with the 
Vena orbitalis posterior. | 

R 2 


244 THE VASCULAR SYSTEM, 


B. The Vena vertebralis (Fig. 160 J’) arises posteriorly and runs 
forwards over the transverse processes of the vertebrae, the Musculi 
intertransversarii, and the M. levat. scapulae, to jom the internal 
jugular vein. In its course it receives branches (Venae spinales) 
from the vertebral canal through the intervertebral foramina, and 
cutaneous branches which accompany the corresponding arteries and 
nerves through the dorsal lymphatic sac. The vein pulsates in 
consequence of its connection with the anterior lymph-heart (Müller). 


(2) The subscapular vein (Vena subscapularis), (Fig. 160 S). 

This vein arises in 

Fig. 161. the transverse abdo- 

minal muscles and 

the muscles of the 

shoulder girdle; it 

unites with the in- 

ternal jugular vem 

under the shoulder- 
cirdle. 


e. The subclavian 
vein (Vena subclavia), 
. (Fig. 159) passes 
~ backwards from the 
anterior caval vein 
on the dorsal surface 
of the coracoid bone 
and the clavicle, and 
then under cover of 
the Portio sternalis 
of the MW. pectoralis 
major, to the internal 
border of the Portio 
abdominalis of the 
M. pectoralis major, | 
where it is formed 
by the union of the 
cutaneous vein and 


Ee 


The anterior caval vein and its branches. the brachial vein 
a Tnnominate vein. l Lingual vein. | 
c.m. Cutaneous vein. m Mandibular vein. ( 1) The cutaneous 
cs. Anterior cava vein. s Brachial vein. : Ve 
a Internal jugular vein. s.c. Subscapular vein. vel. ( rena culanea 


il! ‘External jugular vein. Magna Ecker: Vena 
? 5 


THE VEINS. 249 


musculo-cutanea, Gruby), (Figs. 160, 161, and 162 ¢c.m.). This vein 
arises by small branches in the head ; these are :— 


a. The Vena nasalis (Virchow) ; it arises by an upper and a lower 
branch from around the nostril, and courses backwards along the 
superior maxillary bone to about the middle of the orbit, where it 
joins the facial vein. 


B. The Vena orbitalis anterior (Virchow), (Vena ophthalmica ante- 
rior, Ecker), (Fig. 1600) commences at the Harderian gland from a 
rich anastomosis, 
receives branches Fig. 162. 
from the floor and 
anterior wall of the 
orbit, and joins the 
facial vein with the 
Vena nasalis. ; 


y. The Vena orbi- 
talis posterior (Vir- 
chow), (Vena oph- 


thalmica posterio 1 Course of the cutaneous vein as seen from the side. 
Ecker), (Fig. 1 60 0) c.m. Cutaneous vein. 

à = d M. depressor maxillae. 
arises on the pos- i  M. infraspinatus. 


terior wall of the 

orbit on the M. pterygoideus ; it passes under the Processus zygoma- 
ticus to join the facial vein, and in its course receives the Vena 
ophthalmica (see eye), and communicates with the Vena orbitals 
medialis and the internal jugular vein. 


6. The Vena facialis (Fig. 160) is formed about the middle 
of the orbit by the union of the Vena nasalis and the Jena orbitals 
anterior ; it courses backwards towards the angle of the jaw. On 
reaching the MW. depressor maxillae, about 4 mm. in front of the 
angle of the jaw, it passes on to the skin. It receives in its 
course the Venae palpebrales (Fig. 162) and the Vena orbitalis 
posterior. 

The musculo-cutaneous vein is the direct continuation of the 
Vena facialis after this has left the upper jaw; it immediately 
receives one or more twigs (Venae tympanicae), (Fig. 162) from the 
tympanic membrane and the tympanic cavity. 

The vein then courses backwards in the outer wall of the lateral 
lymph-sae as far as the middle of the trunk, where it passes, by 
means of the Septum abdominale, to the outer border of the Portio 


246 THE VASCULAR 


SYSTEM. 


abdominals of the MW. pectoralis ; here the vein curves round to pass 
forwards between the fibres of this muscle to its inner border where 
it terminates by joining the brachial vein. In the whole of this 
lengthy: course the vein receives numerous branches from the 


neighbouring: parts. 


Fig. 163. 


Veins in the region of the kidney. 


a Renal portal vein. 
a’ Dorso-lumbar veins. 

abd Anterior abdominal vein. 
d Intestine. 

ir Femoral vein. 
i Sciatic vein. 
N Kidney. 
0 

0! 


Right ovary, drawn to the left, 


Oviduct, 
ov Oviducal veins. 
D Mesenteric veins, 
7 Renal veins. 
V Bladder. 
ci. Posterior vena cava, 
Vu Vesical veins, 


(2) The brachial vein 
(Vena brachialis) is formed 
in the Plica cubiti by the 
union of two veins. 


a. The radial vein 
(Vena radialis) arises on 
the dorsum of the hand 
from a venous arch, the 
distal convexity of which 
receives the Venae digitales 
dorsales : the vein courses 
superficially along the 
outer side of the forearm 
to the elbow. 


B. The ulmar vein 
(Vena ulnaris) arises from 
the veins in the palm of the 
hand, and courses towards 
the elbow, lying deeply 
between the muscles of 
the inner and outer sur- 
faces of the forearm. In 
the elbow the vein be- 
comes superficial near the 
tendon of the IW. sterno- 
cleidoradialis, and joins 
the radial vein to form 
the brachial vein. 

The cutaneous veins 
of the fore-limb follow 
courses corresponding: 
with those of the arteries. 


2. The Posterior Caval 
Vein (Vena cava inferior), 
(Fig. 159 Cp, 163 v.c.i.). 


THE VEINS. 247 


The posterior caval vein is a median vein which, commencing be- 
tween the kidneys, runs forwards to open into the posterior end 
of the Sinus venosus. It receives the hepatic, renal, and ovarian or 
spermatic veins. 


a. The hepatic veins (Venae hepaticae), (Fig. 164 v.4.) are two in 
number, one from either side of the liver; they open into the 
posterior caval vein near the Sinus venosus. 


b. The renal veins (/enae renales or Tenae revehentes), (Fig. 
163 7) are four or five small vessels on each side ; they pass from 
the inner border of the kidney inwards and forwards, to form, 
by their union, the posterior caval vein. The most anterior receive 
branches from the fat-bodies (see kidney). 


ce. The spermatic or ovarian veins are four or five in number on 
each side; they open into the posterior caval vein between the renal 
veins. 


3. The Portal Systems. 


[There are, in the frog, two portal systems ; the renal and the 
hepatic. Hach of these receives vessels which are derived, directly 
or indirectly, from the veins of the hinder extremity. 

The femoral vein on entering the pelvis divides to form two 
branches ; an iliac vein placed dorsally, and a pelvic vein placed 
ventrally ; the two pelvic veins converge to the middle line of 
ventral wall of the abdomen, where they unite to form the ante- 
rior abdominal vein. | 


a. The renal portal vein (Vena renalis advehens princeps), (Fig. 
163 a). This vein is formed by the union of the sciatic and the 
iliac veins ; it courses forwards to the outer border of the kidney, 
and is distributed, by numerous branches, to that organ, chiefly 
on its dorsal surface. It receives the following veins :— 


(x) The iliae vein (Vena iliaca externa); this is the dorsal branch 
formed by the bifurcation of the femoral vein. 

(2) The sciatic vein (Vena ischiadica), (Figs. 163 and 165 1) 
arises at the popliteal space, courses upwards in company with the 
sciatic nerve between the M/. semitendinosus and the M. biceps, then 
passes, still with the nerve, between the MW. vastus externus and the 
M. pyramidalis into the pelvis. It continues forwards to join the 
iliac vein. At the root of the thigh this vein communicates with 
the femoral vein by the Ramus communicans iliacus. 


248 THE VASCULAR SYSTEM. 


(3) The dorso-lumbar vein (/ ena dorso-lumbalis), (Fig. 163 a’) is 
a vein (or more usually several) arising by twigs in the dorsal and 
outer walls of the abdomen ; it joins the renal portal vein opposite 
the kidney. 

(4) The oviducal veins (Fig. 163 ov) are irregular veins from 
the oviducts, which open either into the dorso-lumbar vein, or into 
the renal portal vein. 

b. The hepatic portal system. 

The liver receives blood from two sources: (1) from the hind- 
limbs by means of the 
anterior abdominal 
; vein, and (2) from the 
alimentary canal by 
the hepatic portal vein. 


Fig. 164. 


The anterior ab- 
dominal vein (Vena 
abdominalis),(Figs.1 59 
ab, 164 Va) is formed, 
a little in front of the 
symphysis pubis, by 
the union of the two 
pelvie veins. It courses 
forwards along the 
middle line of the 
ventral body-wall un- 
til opposite the liver, 
where it ascends and 
divides into three 
branches, of which 
two enter the right 
and left lobes of the 


eres aa liver respectiveyl. The 

AA Auricles. E Hepatic portal vein. : ; 
aa Right and left branches of 12 Intestinal veins. third, the Ramus de- 

anterior abdominal vein. P’ Gastric veins. scen d ens joins the 
b Ramus descendens. S Sinus venosus. i ? s 
e¢ Vena bulbi (Vena cardiaca). V Ventricle. hepatic portal veln. 
D Intestine. Va Anterior abdominal 5 5 
G Gall-bladder. vain The anterior abdomi- 
L.l. Left lobe of liver. V.c.i. Posterior vena cava. = à - 
Ly, Right lobe of liver, v.h. Hepatic veins, nal vein receives the 


following veins :— 
a. The vesical vein (Vena vesicalis), (Fig. 163 Vv); a median 
vein arising in the groove between the lobes of the bladder from 
lateral branches, which extend outwards on the bladder. This vein 


THE VEINS. 249 


communicates above with other vesical twigs which open into the 
haemorrhoidal vein. 


B. Parietal veins, which join the anterior abdominal vein in its 
course along the ventral body-wall. 

y. A cardiac vein (Vena cardiaca), (Figs. 142, 159 ve, 164 ¢), 
which joins the anterior abdominal vein just before its division 
(see p. 222). 


The hepatic portal vein (/ena portarum), (Figs. 159, 164 P) 
is formed by the union of the gastric, intestinal, splenic, and one 
of the haemorrhoidal veins. The large vem so constituted passes 
forwards towards the liver, receives the Ramus descendens from the 
anterior abdominal vein, and then passes into the left lobe of the 
liver. Its branches are the following :-— 


(1) The gastric veins. The stomach has three veins :— 


a. [The Vena coronaria ventriculi, which receives blood from the 
hinder end of the oesophagus and anterior portion of the stomach. 


B and y. Two other veins which form an Areus coronarius on the 
concave surface of the stomach; the hinder receiving in addition 
the small Venae pancreaticae and the Vena duodenalis; the trunk so 
formed receives the Vena coronaria ventriculi (Hoffmann). 


(2) The intestinal veins; the veins of that portion of the ali- 
mentary canal between the middle of the duodenum and the 
anterior end of the large intestine open into a common vein which 
joins the hepatic portal vein. 


(3) The splenic vein joins either the hepatic portal vein or one 
of the intestinal veins. 


(4) The haemorrhoidal veins are three in number; the anterior 
opens into the splenic vein, the remaining two into the portal veins 
through the agency of the intestinal veins. | 


4. The Veins of the Hinder Extremity. 
The hinder extremity has two venous trunks, the sciatic vein and 
the femoral vein. 


a. The femoral vein (Vena femoralis), (Fig. 165 f) is the larger 
venous trunk of the hinder extremity. It arises in the popliteal 
space as a direct continuation of the posterior tibial vein, courses 
upwards in company with the sciatic artery and nerve, then leaves 
these to wind forwards and outwards, and appears between the 
origins of the MW. vastus externus and of the MW. rectus anterior, 


250 THE VASCULAR SYSTEM. 


The vein here gives off the Ramus communicans iliacus to the sciatic 
vein, and turns forwards and downwards around the JM. glutaens 
maximus to reach the floor 
of the pelvis, near the fe- 
moral artery. The vein 
then bifureates to form the 
pelvic and iliac veins. 


Fig. 165. 


(1) The Ramus commu- 
nicans iliacus (Fig. 165 c.1.) 
forms a communication 
with the sciatic at the base 
of the thigh. 

(2) The posterior tibial 
vein (Vena tibialis postica), 
of which the femoral is a 
continuation, arises on the 
dorsal surface of the toes 
and foot. It runs super- 
ficially on the I. extensor 
longus digiti primi over the 
ankle-jomt, courses up- 
wards and winds round 
the outer surface of the 
tibio-fibula to the flexor 
surface. It receives, in its 
course, muscular branches, 
and at the knee a large 
cutaneous branch. 


b. The sciatic vein: 
this vein has already been 
described (see p. 247), but 
Veins of the hinder extremity, half schematic. the UE from which it 


ci, Vena communicans iliaca. arises requires description. 
af Femoral vein. 
a 


Sciatic vein. The anterior tibial 

a Vena cutanea cruris medialis. . 7 “7 7e ù 
r.a. M. rectus anterior. vein ( J ena tibialis an- 
s.m. M.semimembranosus. tica) arises on the dorsum 

ve, M. vastus externus. ; 

of the foot by twigs from 
the toes; it courses under the J/. extensor longus digit primi, then 
upwards on the anterior surface of the leg, and enters the canal in 


the tibio-fibula to appear on its hinder surface. The vein then 


THE LYMPHATIC SYSTEM. 251 


receives twigs from the JZ. peroneus, the M. tibialis posticus, the M. 
gastrocnemius, and a large cutaneous branch. 


a. The Vena cutanea cruris medialis (Fig. 165 7’) receives branches 
from both above and below, and enters the popliteal space to join 
the anterior tibial vein. 


B. The anastomosis on the dorsum of the foot, from which the 
anterior tibial vein arises, receives perforating twigs from the 
plantar surface. : 


PART IL. 
THE LYMPHATIC SYSTEM. 


(The arrangement of this section has been considerably altered.) 


[The lymphatic system of the frog may, for descriptive purposes, 
be advantageously treated of in four parts : 

1. The subcutaneous lymph-sacs. 

2. The lymph-hearts. 

3. The lymph-spaces of the body, and those lying between 
the various organs. 

4. The lymph-vessels of the separate organs. 


The first two parts will be described in this section ; the remainder 
with the organs or parts of the body with which they are more 
intimately associated. The spleen will be described with the ab- 
dominal viscera. 


1. The Subcutaneous Lymph-Sacs. 

A number of large spaces exist between the skin and the muscles, 
in which there is no direct attachment between these parts. These 
spaces are separated from each other by thin connective-tissue 
septa, stretched between the muscles and the skin, and by attach- 
ments of the skin to the underlying structures. 

Joh. Müller first demonstrated that these spaces were connected 
with the lymphatic system, and that the contained fluid was lymph. 
Although this fact was contradicted by Meyer it received confirma- 
tion from Stannius, Leydig, and especially from Recklinghausen, 
who showed that the fluid of the lymph-saes was carried away by 
the lymphatics, and that later it entered the blood-stream. 


252 THE VASCULAR SYSTEM. 


A. The Lymph-sacs of the Head and Trunk. 

a. The septa. The connective-tissue septa themselves contain 
sinuses which occupy the space between their two surfaces (Fig. 
166): these septal sinuses receive the contents of the cutaneous 
lymph-vessels and forward their contents into lymph-vessels situated. 
in the septa. Such a sinus is shown in transverse section in Fig. 
166, which is a section of the ventral septum. The same sinus, in 
plan, is seen in Fig. 167. 

(1) The dorsal septum (Septum dorsale), (Figs. 169 and 171 d) of 
each side commences at the tympanic membrane ; it is then attached 
to the A7. depressor maxillae, M. infraspinatus, and M, longissimus 


Fig. 167. 


Transverse section of a sep- 
tum with the attached 
skin, its contained sinus 
injected with blue injec- 


tion mass. 
H Skin. 
s Septum, The sinus abdominalis lateralis (Ecker) injected 
S_ Sinus contained in the with blue mass. 
septum. 


H Skin with its lymph-vessels. 

S Sinus of the septum with lymph-vessels 

s an er with the skin. 
dorsi; and continued backwards over the 27. obliquus abdominis 
externus to the anterior end of the I. g/utaeus, whence it extends 
along the iliac bone, where it is connected with the posterior 
lymph-heart and the I/. pyriformis, to the tip of the urostyle. At 
the tip of the MW. g/utaeus it is joined by the iliac septum. The 
posterior part of the septum is horizontal, and forms the roof of the 
iliac lymph-sac. 

(2) The ventral septum (Septum abdominale), (Figs. 169, 170, and 
171 a), commencing at the Symphysis pubis, runs forwards and out- 
wards, on either side, along the outer border of the 47. rectus abdom- 
inis to the Portio abdominalis of the A. pectoralis ( y”), where it is 
attached, at a right angle, to the pectoral septum ; it then extends 
forwards, after attachment to the axillary septum, to the outer 


THE LYMPHATIC SYSTEM. 253 


angles of the maxillary septum. At the root of the anterior ex- 
tremity it divides to enclose the root of the limb, and so form the 
axillary septum. 


(3) The pectoral septum (Septum pectorale), (Figs. 170 and 171 p) 
is attached to the superficial surface of the 7. pectoralis (Portio 
sternalis, anterior and posterior) ; it runs transversely across the body, 
and is attached at its outer end to the ventral and to the maxillary 
septa. The septum passes obliquely backwards and downwards 
to be attached to the skin, and so forms a very acute angle with 
the WM. cutaneus pectoris (cp): a vertical band of connective-tissue, 
broad behind, narrow in front, extends in the middle line from the 
septum to the body wall; from it a certain amount of loose con- 
nective-tissue extends in all directions, and forms open lymph-spaces 
between the IZM. cutanei pectorales and the vertical septum. 


(4) The perineal septum (Septum 
perineale), (Fig. 170 pe). This me- 
dian septum extends from the at- 
tachment of the dorsal septum to the 
tip of the urostyle, backwards to the 
symphysis pubis, where it joins the 
ventral septa. In its attachment 
it follows the middle line of the 
perineum. 


Fig. 168. 


(5) The maxillary septum (Sep- 
tum maxillare), (Figs. 170, 171 #) 
is attached by either extremity Sinus thoracicus transversus (Ecker). 


to the dorsal septum, near the cp M. cutaneus pectoralis. 
tympanic membrane, is continued Fike ie on ee 
downwards to unite with the 

anterior end of the ventral septum, and then runs across the 
anterior pectoral region, forming a curve with the convexity 
forwards. It has inserted into it fibres of the 27. submaaillaris. 
The septum is formed of very loose tissue, and frequently contains 
deposits of fat; it encloses a well-marked septal sinus, the Sinus 
thoracicus transversus (Kicker). 


(6) The iliac septum (Figs. 169, 172 15, 173 S’) is a septum 
extending from the dorsal septum to the inguinal septum. It is 
attached to the dorsal septum opposite the anterior end of the 
M. glutaeus, and extends outwards and downwards to the inguinal 


254 


THE VASCULAR SYSTEM. 


Fig. 169". 


septum. In it 
the M. cutaneus 
iliacus passes 
from the trunk 
to the skin. 

(7) The ingui- 
nal septum (La- 
mina imguinalis, 
Ecker), (Figs. 
169, 171, the 
dotted line near 
15, Fig. 172, 
separates the 
belly from the 
thigh ; on the 
ventral surface 
it is attached to 
the groove which 


The lymph-sacs of Rana 
esculenta, seen from the 
dorsal surface. 


r Dorsal lymph-sac. 

3 Lateral lymph-sac. 

7 Brachio-radial lymph- 
sac. 

g Femoral lymph-sac. 

ro Suprafemoral lymph- 
sac. 

rr Interfemoral lymph- 
sac. 

12 Crural lymph-sac, 

13 Dorsal lymph-sac of 
the foot. 

14 Plantar lymph-sac of 
the foot. 

15 Iliac lymph-sac. 

a Ventral septum. 

d Dorsal septum. 


jf’ Superior femoral sep- 


tum. 


JS‘ Intermediate femoral 


septum. 

i Inguinal septum. 

s Posterior brachial sep- 
tum. 

s/” Anterior brachio - ra- 
dial septum. 

V Vocal sac. 


‘ In Figs. 168, 169, and 170 the dotted lines denote the boundaries of the various 


lymph-sacs. 


RÉ 


THE LYMPHATIC SYSTEM. 255 


forms the boundary between the belly and thigh; on the dorsal 
surface it is more posterior, and is attached to the dorsal surface of 
the muscles of the thigh at some little distance from the trunk. It 
completely surrounds the root of the hinder limb. It has attached 
to it the ventral, dorsal, and iliac septa, together with the septa 
of the thigh. 


b. The lymph-sacs. 


(1) The dorsal lymph-sac (Saccus cranio-dorsalis), (Figs. 169 and 
171 1). This is a large lymph-sac, extending from the tip of the 
snout to the tip of the urostyle; it is bounded in front by the 
attachment of the skin to the premaxillary bones; the line of 
attachment is continued, on either side, along the inner border of 
the external nares, then forms a pouch towards the jaw and in front 
of the eye, and runs backwards along the upper border of the orbit, 
where it is attached to the upper eyelid, to the inner border of 
the tympanic membrane. In this course the skin is firmly attached 
to the underlying parts. The lateral boundary of the lymph-sac, 
behind this point, is formed by the dorsal septum, which separates 
it from the lateral lymph-sae. 


(2) The ventral lymph-sac (Saccus abdominalis), (Figs. 170, 171 2) 
is triangular in form, with the base forwards at the breast, and the 
apex behind at the pelvic symphysis ; it occupies the space between 
the skin below and the belly muscles and part of the A7. pectoralis 
above. It is bounded anteriorly by the pectoral septum (y) and 
laterally by the ventral septa (4). 


(3) The lateral lymph-sae (Saccus lateralis), (Figs. 169, 170, and 
171 3) exists on either side; below, the sac is bounded by the 
ventral septum (a), above by the dorsal septum (7), anteriorly by the 
maxillary septum (#),and posteriorly by the inguinal septum (7) and 
the wall of the iliac lymph-sac. 


(4) The submaxillary lymph-sac (Saccus submaxillaris), (Figs. 
170 and 171 4) is a space between the #7. submaxillaris and the 
skin; the sac is bounded behind by the maxillary septum, which 
separates it from the pectoral lymph-sac, and more laterally from 
the lateral lymph-sac. In front and at the sides the skin is firmly 
attached to the margin of the mandible. 


(5) The pectoral lymph-sac (Saccus thoracicus), (Figs. 170 and 
171 5) hes between the submaxillary and ventral lymph-sacs. The 


256 THE VASCULAR SYSTEM. 


Lymph-saes of Rana esculenta, 


Ventral lymph-sac. 
Lateral lymph-sac. 
Submaxillary lymph-sac. 
Thoracic lymph-sac. 
Brachio-ulnar lymph-sac. 
Anterior brachial lymph- 


© oui À W D 


sac. 

Femoral lymph-sac. 

11 Interfemoral lymph-sac. 

32 Crural lymph-sac. 

13 Dorsal lymph-sac of the 
foot. 

14 Plantar lymph-sac of the foot. 


Ke) 


is} 


m 


LAVARA ELU Deas 
= TEE 


\C 
\\P 
\ 


\ 


Ventral septum. 
Anterior division of ventral 
septum. 


septum. 


-Sm 


Ip 
\ 
\ 


‘ 
\h 


/ 
| 


seen from the ventral surface. 
m Attachment of maxillary sep- 
tum to skin. 
Pectoral septum. 
Posterior division of ventral p’” Port. abdom. of the M. pecto- 


ralis. 


Intermediatefemoral septum. pe Perineal septum. 
r M 


M. cutaneus pectoris. 
Inferior femoral septum. 
Inguinal septum. 
Attachment of inguinal 
septum to skin. 
Maxillary septum. 


_ rectus abdominis. 
ri’ M. rectus internus minor. 
s’ Anterior brachio-ulnar sep- 
tum. 
s! Anterior brachial-radio sep- 


um. 
sm Muse. submaxillaris. 


- 


ee st à AE 


THE LYMPHATIC SYSTEM. Qe 


sac is bounded behind by the pectoral septum (y), and in front by 
_ the maxillary septum (7). 
(6) The iliac lymph- 
sac (Saccus  iliacus), 
(Figs. 171 and 172 15, 
173) does not really be- 


long to the subeutane- sm: 
ous lymph-sacs, as it | 
does not lie directly un- LE 


der the skin except by a 

very narrow border. It 

is bounded in front by 

the iliac septum, above 

by the dorsal septum, 

and posteriorly by the 

inguinal septum. By 

these boundariesa space SL 
is enclosed, which lies - 
under the dorsal septum 

and dorsal sac, and at 

the same time partly 

under the lateral sac. 

In this sac the J. 

glutaeus, the anterior 

ends of the MW. vastus 

externus, M. rectus an- 

terior, and M. cutaneus 

iliacus, lie free together 


The lymph-sacs of Rana esculenta, 
seen from the side. 
t Dorsal lymph-sac. 
2 Ventral lymph-sac. 
3 Lateral lymph-sac. 
4 
5 


Submaxillary lymph-sac. 
Pectoral lymph-sac. 
g Femoral lymph-sac. 
10 Suprafemoral lymph-sac. 
12 Crural lymph-sac. 
15 Iliac lymph-sac. 
a Ventral septum. 
dad Dorsal septum. 
~ Inguinal septum. 
m Maxillary septum. à 
m’ Attachment of M, submaxil- 2 TT 
laris to the skin. 
p  Pectoral septum, 
sm M. submaxillaris. 
v Vocal sac. 


258 THE VASCULAR SYSTEM. 


with the hindmost part of the 97. obiquus abdominis externus, 
and the hinder portion of the posterior lymph-heart. Anteriorly 
the floor is depressed between the J. obliquus abdominis and the 
M. glutaeus, the depression leading to a canal, which communicates 
with the abdominal cavity. 


B. The Lymph-sacs of the Anterior Extremity. 


a. The septa. 

(1) The axillary septum (Septum axillare), (Figs. 170 4”, a”, 
171) is practically a portion of the ventral septum, which divides 
at the root of the arm to enclose it. The dorsal and ventral por- 
tions of this circular septum have received special names. 

a. The dorsal axillary septum 
(Septum axillare dorsale) crosses the 
M. triceps and joins the pectoral 
septum. 

B. The ventral axillary septum 
(Septum  axillare dorsale) passes 
through the axilla and joins the 
pectoral septum. 


er 


Transverse section through the trunk in the 
region of the iliac Jymph-sac. 


The circular axillary septum has 


€  Urostyle. : ° 

¢ Skin. attached to it the following :— 

o Muscles of abdominal wall. 

t Dorsal lymph-sac. (2) The posterior brachial sep- 


3 Lateral lymph-sac. 
15 Iliac lymph-sac. 


tum (Septum brachiale posticum (Fig. 
169 s); it is attached along the 
middle line of the extensor surface of the arm (long head of the 
M. triceps) to the elbow and to the forearm (AZ. anconaei), then passes 
obliquely over the volar surface of the hand to the fourth finger. 

(3) The anterior brachio-ulnar septum (Septum brachiale anticum 
ulnare), (Fig. 170s”) commences at the same point as the foregoing, 
passes obliquely over the outer head of the A7. triceps, and is con- 
tinued over the W/. flexor antibrachii lateralis, M. supinator longus, and 
AT. extensor digitorum communis, to the dorsal surface of the fourth 
finger. 

(4) The anterior brachio-radial septum (Septum brachiale an- 
ticum radiale), (Fig. 170 s”’) passes from the outer angle of the wall 
of the pectoral lymph-sac, over the inner head of the J/. ¢riceps and 
M. flexor carpi radialis to the thumb. 


b. The lymph-saes are enclosed by these three septa; they are 
four in number :— 


THE 


LYMPHATIC SYSTEM. 


259 


(1) The brachio-ulnar lymph-sae (Saceus brachialis ulnaris), 
(Fig. 170 6) is situated between the first and second septa along the 


extensor and ulnar surfaces. 

(2) The brachio-radial lymph-sac (Saccus 
brachialis radialis), (Fig. 169 7) is placed 
along the extensor and radial surfaces. 


(3) The anterior brachial lymph-sac 
(Saceus brachialis anticus), (Fig. 170 8) lies 
on the flexor surface between the second 
and third septa; it is a long cavity and in- 
terrupted by connective-tissue bands, in 
which the tendon of the J/. sterno-radialis 
and the nerve and vessels are situated. 


(4) The axillary lymph-sae (Saceus axil- 
laris) corresponds to the iliac lymph-sac ; 
it is bounded by the divisions of the ventral 
septum. 

In the hand no large lymph-space exists ; 
the skin is attached by numerous bands to 
the underlying structures. 


C. The Lymph-saes of the Hinder Ex- 
tremity. 

a. The septa. 

(1) The superior femoral septum (Sep- 
tum femorale superius), (Figs. 169 and 175 f”) 
is attached above to the inguinal septum 
near the posterior lymph-heart; and is 


Dissection to show the iliac 
lymph-sac. 


g M.glutaeus. 

ic. M, ilio-coccygeus. 

m.c. M. cutaneus iliacus. 

o M. obliq. abdom. externus, 

r M. rectus. 

S Dorsal septum. 

S’ Iliac septum. 

S” Portion of dorsal septum, 
which forms the roof of the 
iliac lymph-sac. 

vu M. vastus externus. 

* Aperture, by which [the iliac 
lymph-sac communicates 
with the abdominal cavity. 


continued, from this point, over the AZ. vastus externus and along 


the M. triceps to the knee. 


(2) The inferior femoral septum (Septum femorale inferius), (Figs, 
170 and 175,/”) runs from the inguinal septum near the point 


of insertion of the MZ. rectus abdominis, along the 


M. rectus internus minor to the knee. 


(3) The intermediate femoral septum (Septum 
Jemorale intermedium), (Figs. 169 and 175 f””’) passes 
from near the posterior lymph-heart over the 
M. semimembranosus and the M. rectus internus minor 


to jo the inferior femoral septum. 


S 2 


Fig. 174. 


Plan of attachments 
of the inferior fe- 
moral, inguinal, 
and perineal septa- 


260 THE VASCULAR SYSTEM. 


(4) The tibio-femoral septum (Septum femoro-crurale) is a circular 
band, separating the lymph-sacs of the thigh from the leg sac. 

(5) The septa of the foot. At the ankle joint the skin is closely 
attached all round to the underlying parts. Along the outer border 
of the foot a septum is attached to the skin externally, and to the 
underlying parts, especially the 27. abductor longus digiti primi, 
internally. A similar but weaker band is attached along the outer 
border of the foot, especially to the MW. adductor digiti quinti. 


b. The lymph-sacs. 
(1) The femoral lymph-sac (Saccus femoralis), (Figs. 169, 170, 
171, 175 9) covers the lower and outer surfaces of the thigh ; it is 
bounded by the superior femoral and 
inferior femoral septa, and in front 
sm by the inguinal septum. 


Fig. 175. 


(2) The suprafemoral lymph-sac 
(Saccus suprafemoralis), (Figs. 169, 
171, 175 10) lies on the upper sur- 
AE NES face of the thigh, between the 
ve PRE Nr superior and intermediate femoral 

Transverse section of the thigh. septa; above it is bounded by the 


b M. biceps. os 
Jf’ Superior femoral septum. inguinal septum. 


f" Inferior femoral septum. The i x 

J’’ Intermediate femoral septum. (3) e interfemoral lymph Bice: 
H Skin. (Saccus interfemoralis), (Figs. 169, 
vi’ M. rectus internus major. : t t] 
ri’ M.rectus internus minor. 170, 1) 11) 1S a harrow sac on the 
NS oer inner surface of the thigh, between 
sm M. semimembranosus. : D 

ve M. vastus externus, the inferior femoral septum and the 
g Femoral lymph-sac. : 4 : 2 : 

Toe Snprafemoral Lapheeao, intermediate femoral septum. It 
ECM ETES covers the I. rectus internus minor, 


and is interrupted by numerous bands of tissue which pass from the 
surface of the muscle to the skin. It is, therefore, not a simple sac, 
but a very wide-meshed trabecular structure of connective-tissue. 
The sac is triangular in shape, with the base directed forwards at 
the inguinal septum. 


(4) The lymph-sac of the leg is a simple sac enclosing the 
whole leg, bounded above by the tibio-femoral septum, and below by 
the attachment of the skin to the ankle. 

(5) The lymph-sacs of the foot. On the dorsum of the foot the 
skin is free, and there is consequently a lymph-sac. On the plantar 
surface the skin is attached by numerous connective-tissue bands 
and thread-like tendons, particularly to the flexor tendons. The 


THE LYMPHATIC SYSTEM, 261 


skin of the dorsal and plantar surfaces meet on the web and 
enclose a very rich anastomosis of lymph-capillaries. 


2. The Lymph-Hearts. 
The frog has two pairs of lymph-hearts, one pair anterior, the 
other posterior. 


A. The anterior lymph-hearts (Fig. 176). These organs lie, 
one on each side, behind the broad transverse processes of the third 
vertebra (Müller, Panizza, Priestley), in a deep triangular space 
formed by the separation of the fibres of the M/. intertransversarius, 
between the transverse processes of the third and fourth vertebrae. 
Each heart is a rounded sac, slightly elongated anteriorly where 


Bivel 77: 


Fig. 176. 


The anterior lymph-hearts. 


L The left anterior lymph- 


heart, 
1s. M, levator scapulae. The posterior lymph-hearts, 
N Brachial nerve, gt OM. glutacus. 
ts. M,  transverso - scapularis de M. ilio-coccygeus, 
maior, L Posterior lymph-hearts, 
1-4 Vertebrae numbered from p  M. pyriformis, 
before backwards, r M. rectus. 


ve M, vastus externus, 

it is connected with the subscapular vein. [The hearts receive 
lymph from the anterior part of the body and the surrounding 
parts, and empty their contents into the vertebral vein. Hach of 
these hearts is supplied by a branch from the second spinal nerve 
(Volkmann, Eckhard, Schiff, Priestley). | 

B. The posterior lymph-hearts (lig. 177) are situated on either 
side of the urostyle in the triangular spaces (Miller, Panizza, 
Priestley), bounded externally and above by the M. glulacus, 


262 THE VASCULAR SYSTEM. 


internally and above by the J/. coccygeo-iliacus, below and exter- 
nally by the origin of the A7. vastus externus, and below by the 
M. pyramidalis. Each posterior heart is about two lines long and 
one broad, with its long axis placed antero-posteriorly ; the outer — 
surface is uneven and appears to be unequally dilated. The lymph- 
heart is closely attached to the surrounding parts, especially to 
the fascia covering the I. i/ii-coccygea, and posteriorly to the 
M. levator aniand the M. pyramidalis. [The posterior lymph-hearts 
receive lymph from the parts surrounding them, and from the 
hinder extremities, and forward it into the /. ¢/iaca communicans. 
The posterior lymph-hearts are each supplied by a branch from 
the corresponding coccygeal nerve (Waldeyer) by its dorsal branch. 
The lymph-hearts are also in close connection with the sympathetic 
system (Waldeyer).] | 


PART IIL 


THE BLOOD, LYMPH, AND HISTOLOGY OF 
THE VESSELS. 


[The parts described in this section will be considered very 
briefly, and only from an anatomical point of view. 


A. The blood !. 


The blood varies in colour, according as it is obtained from an 
artery or from a vein; from an artery it has a bright red or scarlet 
colour ; from a vein a darker shade: in the pulmonary vessels these 
colours are reversed. The blood consists of a fluid plasma which 
contains red and white corpuscles: the whole forming a slightly 
alkaline, opaque, and somewhat sticky fluid. 


a. The plasma or /iquor sanguinis is a transparent, clear, slightly 


yellow fluid, faintly alkaline in reaction. 


' Mr. Hurst has noticed a frog (R. temporaria) in which the blood was perfectly 
colourless. 


THE BLOOD, LYMPH, AND HISTOLOGY OF THE VESSELS. 263 


b. The corpuscles are of two kinds, colourless and coloured. 
2 


(1) The colourless or white corpuscles are subspherical masses of 
protoplasm, endowed with the power of spontaneous motion. They 
are much fewer than the red corpuscles, though the proportion of 
white to red varies considerably. Three chief varieties of colourless 
corpuscles can be distinguished, all of which are true cell forms, 
and behave like other cells with stainimg or other reagents. They 
have no cell-wall, but are simply nucleated masses of protoplasm. 
These corpuscles possess the power of passing through the walls 
of the blood-vessels, and are then known as migratory cells; such 
migratory cells can be found in nearly all tissues, but more espe- 
cially in the connective-tissues. 


a. Ordinary large colourless corpuscles are large transparent 
masses of protoplasm containing one or two nuclei, rarely three 
or more. The cell contains few granules, and usually has one or 
more vacuoles or clear spaces containing fluid. 


8. Granular corpuscles are less numerous than the foregoing, but 
larger, and are distinguished by the numerous large dark granules 
which they contain. The processes such a corpusele sends out are 
hyaline. 


y. Smaller corpuscles also occur varying much in form: they may 
consist of a nucleus with a very small amount of hyaline or granu- 
lar protoplasm, or of several nuclei with an extremely small amount 
of protoplasm. 


(2) The coloured corpuscles are much more numerous than the 
colourless corpuscles; each is a bi-concave, oval dise, about 
00255 mm. in length, and o‘o17 mm. in breadth (Gulliver)! 
(R. temporaria, 0°0235 and 00145 mm. respectively). Each cor- 
puscle possesses an oval nucleus (Hewson)?, which projects into 
either concave surface of the whole corpuscle. These corpuscles 
do not possess the power of spontaneous movement; and have no 
cell-wall. The corpuscles are of a reddish-yellow colour, and 
give the blood its characteristic hue. The colouring matter is 
haemoglobin, and when separated it crystallizes in prisms (Preyer). 
The corpuscles show a well-marked intracellular and intranuclear 
network. | 


* Gulliver, Proc. Zool. Soe. London, 1845, Vol. XIII, p. 93 seq. 
* Hewson, Phil. Trans. 1773, Vol. LXIII, p. 310 seq. 


264 THE VASCULAR SYSTEM, 


B. [The Lymph and Chyle. 

The lymph is that portion of the blood which has filtered from 
the blood-vessels, through the tissues, into the lymphatics. It isa 
clear, transparent fluid, containing colourless corpuscles, which agree 
in all particulars with the colourless corpuscles of the blood. During 
digestion the lymph from the alimentary canal contains particles of 
fatty matter, and is then known as chyle.] The colourless cor- 
puseles of the lymph frequently contain portions of red corpuscles 
or granules of pigment. Non-nucleated masses of protoplasm and 
decolourised red corpuscles (slightly diminished in size) have also 
been described as occurring frequently in the lymph (Fuchs’).] 


C. [Histological Remarks on the Vascular System. 
a. The heart has already been described (pp. 216-222). 


b. The blood-vessels present the same structure as the corre- 
sponding vessels in higher animals. The arteries and veins have 
each the three walls or layers usually described—TZunica adventitia, 
Tunica media, and Tunica intima. The only characteristic to be men- 
tioned is that the Zunica adventitia contains branched, pigmented 
corpuscles. The Nervi vasorum, especially of the smaller arteries, 
are arranged in two plexuses, one in the Twxica adventitia (His) ?, 
the second in the muscular coat (J. Arnold)*. The fibres of both 
plexuses are non-medullated, and haye the usual beaded appearance ; 
they communicate freely with each other. The capillaries present, 
as a rule, the usual structure: such special arrangements of the 
capillaries or peculiarities in structure as occur will be described 
with the organs in which they are found. 


ce. The subcutaneous lymph-sacs are lined with a layer of 
endothelium resembling the endocardium shown in Fig. 140; the 
endothelial layer possesses stomata (see peritoneum), through which 
the lymph-sacs communicate with the underlying lymphatics. The 
endothelium is continued on to the vessels, nerves, etc., which 
course through the sacs, and excludes these from the cavities. As a 
rule an artery, vein, and nerve are enclosed in a common sheath. 


d. The lymph-hearts are small saccular bodies with thin trans- 
parent walls, which contain obscurely striated muscle-fibres. The 
vessels communicating with the hearts appear to possess valves 


? Fuchs, Virchow’s Arch. 1877, Vol. LX XI, p. 78 seq. 
? His, Virchow’s Arch. 1863, Vol. XXVIII, p. 427. 
8 Arnold, in Stricker’s Handbuch d. Gewebelehre, p. 137. 


THE BLOOD, LYMPH, AND HISTOLOGY OF THE VESSELS. 265 


(Müller). The walls of the hearts are formed of three layers; an 
external, compared by Waldeyer to an adventitia, a muscular layer, 
and an endothelial lining. The muscular fibres form a close inter- 
lacing mass, the fibres being small, branched (Leydig), and pos- 
sessed of many nuclei. Among the muscular fibres are pigmented 
corpuscles, together with medullated and non-medullated nerve- 
fibres, but no ganglion-cells (Volkmann, Waldeyer, Priestley). 
The adventitia is a connective-tissue layer with many pigment 


cells (Leydig, Hyrtl, Waldeyer). | 


SECTION V. 


THE ALIMENTARY TRACT WITH ITS APPENDAGES, 
THE SPLEEN, AND THE PERITONEUM. 


THE ALIMENTARY TRACT, ETC. 


LITERATURE. 


THE MOUTH. 


(Except the mucous membrane of the tongue, for which see organ of taste.) 


Ducrotay de Blainville, H. M., Ostéographie ou description iconographique 
comparée du squelette et du système dentaire des cinq classes d’animaux vertébrés. 
Paris, 1841. 
Erdl, Ueber den Bau der Zähne bei den Wirbelthieren, ete. München, 1841. 
Fixen, C., De linguae raninae structura. Dorpat, 1857. 
Heincke, F., Untersuchungen über die Zähne niederer Wirbelthiere. Zeitsch. f. | 
wiss. Zool. 1873. Vol. XXIII, p. 495. | 
Hertwig, O., Ueber das Zahnsystem der Amphibien, etc. Suppl. to Vol. XI, 
Arch. f. mik. Anat. 1874. 
Hoffmann, C. K., Bronn’s Thierbuch. Leipzig and Heidelberg, 1873-1878. Vol. 
NAL p-270; 
Holl, M. Zur Anatomie der Mundhéhle von Rana temporaria. Wiener Acad. | 
Sitzungsb. 1887. Vol. XCV, Pt. III, p. 47. | 
Hoyer, Ueber die Epithelzellen der Froschzunge, sowie über den Bau der Cylinder- 
und Flimmerepithelien und ihr Verhältniss zum Bindegewebe. Arch. f. Anat. 
u. Physiol. 1858, p. 163; also Deutsche Klinik, 1857. 
Langer, C., Ueber das Lymphgefiisssystem des Frosches. Wiener Acad. Sitzungsb. | 
1867. Vol. LV, Pt. I, pp. 614-621. | 
Leydig, Die Anuren Batrachier der deutschen Fauna. Bonn, 1877. 
Owen, R., Odontography. London, 1840-1845, p. 187. | 
Reichel, P., Beiträge zur Morphologie der Mundhühlendrüsen der Wirbelthiere. 
Leipzig, 1882 ; also in Morph. Jahrb. 1882, Vol. VIII, pp. 1-72. | 
Santi Sirena, Untersuchungen über den Bau und die Entwicklung der Zähne bei 
den Amphibien und Reptilien. Verhandl. d. phys.-med. Gesellsch. in Wiirz- 
burg, 1872. Vol. IT, new series, p. 125. 
Schôbl, J., Ueber divertikelbildende Capillaren in der Rachenschleimhaut nackter 
Amphibien. Sitzungsb. d. k. b. Gesellsch. d. Wiss. in Prag. 1878, p. 25; 
also in Arch. f. mik. Anat. 1885, Vol. XX V, p.80. 
Schultze, F. E., Das Driisenepithel der schlauchférmigen Drüsen des Dünn- und 
Dickdarms und die Becherzellen (of the pharyngo-oral cavity). Centralbl. f. d. 
med. Wiss. 1866, p. 61. 
Schultze, F. E., Epithel- und Driisen-Zellen. Arch. f. mik. Anat. 1867. Vol. III, 
Pp- 137- 
Smith, W. J., Beitrag zur differentiellen Diagnose der Rana fusca s. platyrrhinus 
und Rana arvalis s. oxyrrhinus auf Grund der an den Gaumenzähnen nachweis- 
baren Unterschiede. Pfliiger’s Arch. f. d. ges. Physiol. 1883. Vol. XXXII, 


pp. 581-588. 


LITERATURE. 269 


Tomes, C. S., On the development of the teeth of the newt, frog, slowworm, and 
green lizard. Phil. Trans. 1874, p. 285. 

Tôrôk, Untersuchungen über die Entwickelung der Mundhôhle, ete. Wiener 
Sitzungsb. 1866. Vol. LIV, Pt. I, p. 75. 

Waller, A., Microscopic examination of the principal tissues of the tongue, etc. 
Phil. Mag. 1846, pp. 273-290. 

Waller, A., On the development of the mouth and tongue of the frog. Phil. Mag. 
1850. Vol. I, pp. 38-43. 

Zeller, A., Die Abscheidung des indig.-schwefelsauren Natrons in den Driisen (In- 
termaxillary gland). Virchow’s Arch. 1878. Vol. LX XIII, p. 257. 


THE OESOPHAGUS AND STOMACH. 


Biedermann, Untersuchungen über Magenepithel. Wiener Acad. Sitzungsb. 1875, 
Vol XIE TRI p.277 

Bischoff, Ueber den Bau der Magenschleimhaut. Arch. f. Anat.u. Physiol. 1838, 
Pp- 503. 

Bleyer, E., Magenepithel und Magendriisen der Batrachier. Dissert. Künigsberg, 
1874. 

Braun, Zum Vorkommen von Flimmerepithel im Magen. Zool. Anzeiger. 1880. 
No. 69, p. 568. 

Brinton, in Cyclopaedia of Anat. and Physiol., edited by R. B. Todd. 1859. Vol. I, 
Pp: 320. 

Cobelli, Le gliandole acinose del cardia. Wiener Acad. Sitzungsb. 1866. Vol. 
LITE, Pt. I, p. 251. 

Ebstein, W., Beiträge zur Lehre vom Bau und den physiologischen Funktionen 
der sogenannten Magenschleimdriisen. Arch. f. mik. Anat. 1870. Vol. VI, 
p- 515. 

Ecker, A., Ueber die Driisen der Magenschleimhaut. Zeitsch. f. rat. Med. 1852, 
p. 243: 

Foster, M., On some points in the epithelium of the frog’s throat. Journ. of Anat. 
and Physiol. 1869. Vol. IV, p. 394. 

Frerichs, On the Stomach, in Wagner’s Handwürterbuch d, Physiol. 1848. Vol. IT, 
p. 748. 

Glinsky, A., Zur Kenntniss des Baues der Magenschleimhaut der Wirbelthiere. 
Centralbl. f. d. med. Wiss. 1883, p. 225. 
Gonjaew, K., Die Nerven des Nahrungsschlauches. Arch. f. mik, Anat. 1875. Vol. 
XI, pp. 479-496. 
Hebold, O., Ein Beitrag zur Lehre von der Sekretion und Regeneration der 
Schleimzellen. Dissert. Bonn, 1879, pp. 21-27. 

Heidenhain, R., Untersuchungen über den Bau der Labdriisen. Arch. f. mik. Anat. 
1870. Vol. VI, p. 368. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig und 
Heidelberg. 1873-1878. Vol. VI, pp. 408-412. 

Just, A., Zur Histologie und Physiologie des Flimmerepithels. Breslauer ärztliche 
Zeïtsch. 1885. No. 18, pp. 205-206. 

Klein, E., Darmkanal, in Stricker’s Gewebelehre, p. 388, etc. 

v. Kolliker, A., Mikroskopische Anatomie, 1854. Vol. II, p. 147. 

Langley, J. N., and Sewall, H., On the changes in pepsin-forming glands during 
secretion. Journ. of Physiol. 1880. Vol. II, pp. 261, 281. 

Langley, J. N., On the histology and physiology of pepsin-forming glands. Phil. 
Trans. 1881. Vol. CLX XII, Pt. III, pp. 663-712. 


270 THE ALIMENTARY TRACT, ETC. 


Langley, J. N., On the structure of secretory cells and on changes which take place 
in them during secretion. Internat. Monatschr. f. Anat. u. Histol. Vol. I, 
pp. 69-76. 

Leydig, Lehrbuch der Histologie. 1857. 

Nussbaum, M., Ueber den Bau und die Thätigkeit der Drüsen. Arch. f. mik. 
Anat. 1882, Vol. XXI, p. 296; 1882, Vol. XXVIII, p. 296; 1877, Vol. XIII, 
je ypatite 

Partsch, C., Beiträge zur Kenntniss des Vorderdarmes einiger Amphibien und 
Reptilien. Arch. f. mik. Anat. 1877. Vol. XIV, p. 179. 

Regéczy, E. N., Ueber die Epithelzellen des Magens. Arch. f. mik. Anat. 1880. 
Vol. XVIII, pp. 408-411. 

Robinson, C., Ueber die Lymphgefiisse der Abdominaleingeweide des Frosches, etc. 
Froriep’s Notizen, 1846. No. 807, col. 225. 

Rollett, Bemerkungen zur Kenntniss der Labdrüsen und der Magenschleimhaut. 
Untersuch. in d. Institut f. Physiol. u. Histol. zu Graz. 1871. 

Schultze, F. E., Epithel- und Driisenzellen. Arch. f. mik. Anat. 1867. Vol. III, 
p- 174; abstract in Centralbl. f. med. Wiss. 1866, No. 4. 

Schmidt, C., Ueber eingenthiimliche aus dem Flimmerepithel hervorgehende Gebilde. 
Arch. mik. Anat. 1881. Vol. XX, p. 123. 

Sewall, H., A note on the processes concerned in the secretion of the pepsin- 
forming glands of the frog. Studies in the Biol. Laborat., Johns Hopkins 
Univers. Vol. II, pp. 131-134. 

v. Swiecicki, H., Untersuchungen über die Bildung und Ausscheidung des Pepsins 
bei den Batrachiern. Pfliiger’s Arch. f. d. ges. Physiol. 1876. Vol. XIII, 


Trinkler, N., Zur Kenntniss des feineren Baues der Magenschleimhaut, insbesondere 
der Magendriisen. Centralbl. f. med. Wiss. 1883, pp. 161-163. 

Trinkler, N., Ueber den Ban der Magenschleimhaut. Arch. f. mik. Anat. 1885. 
Vol. XXIV, p. 74. 

Trütschel, Ueber die Endigung der Nerven in der Schleimhaut des Magens. 
Centralbl. f. d. med. Wiss. 1870, p. 115. 

Valatour, Recherches sur les glandes gastriques et sur les tuniques musculaires du 
tube digestif dans les poissons ossieux et les Batraciens. Annales de Sc. nat. 
1861. Series IV. Vol. XVI, p. 210. 


THE INTESTINE. 


Arnstein, C., Ueber Becherzellen, etc. Virchow’s Arch. 1867. Vol. XXXIX, 
js ROT 

Arnstein, C., and Gonjaew, K., Ueber die Nerven des Verdauungskanals. Pfliiger’s 
Arch. f. d. ges. Physiol. 1874. Vol. VIII, pp. 614-615. 

Auerbach, L., Fernere vorläufige Mittheilung über den Nervenapparat des Darmes. 
Virchow’s Arch. 1864. Vol. XXX, p. 457. 

Auerbach, L., Untersuchungen über Lymph- und Blutgefässe. Virchow’s Arch. 
1865. Vol. XXXIII, p. 340. 

Auerbach, L., Organologische Studien. 

Billroth, T., Ueber die Epithelzellen der Froschzunge ; der Bau, Cylinder- und Flim- 
merepithel und ïhr Verhältniss zum Bindegewebe. Arch. f. Anat. u. Physiol. 
1858, p. 159. 

Billroth, T., Einige Beobachtungen über das ausgedehnte Vorkommen von 


Nervenanastomosen im Tractus intestinalis. Arch. f. Anat. u. Physiol. 
1858, p. 148. 


LITERATURE. 27 


Brettauer und Steinach, Untersuchungen über das Cylinderepithelium. Wiener 
Akad. Sitzungsb. 1857. Vol. XXIII, p. 303. Moleschott’s Zeitsch. 1857. 
VGl TE ps 15 7 

Darsch, O., Beitriige zur Kenntniss des feineren Baues des Dünndarmes. Wiener 
Sitzungsb. 1880. Vol. LX XXII, Pt. III, p. 168. 

Dônitz, Ueber die Schleimhaut des Darmcanals. Arch. f. Anat. u. Physiol. 1864, 
p- 367. 

Dônitz, Ueber Darmzotten. Arch. f. Anat. u. Physiol. 1866, p. 757. 

Eberth, C. J., Ueber den feineren Bau der Darmschleimhaut. Würzb. naturw. 
Zeitschr. 1864. Vol. V, p. 23. 

Eimer, T., Zur Fettresorption, ete. Virchows Arch. 1867. Vol. XXXVIII, 
p. 428. 

Eimer, T., Ueber Becherzellen. Virchow’s Arch. 1868. Vol. XLII, p. 490. 

Eimer, T., Zur Geschichte der Becherzellen. Dissert. 1867. 

Eimer, T., Die Wege des Fettes in der Darmschleimhaut bei seiner Resorption. 
Virchow’s Arch. 1869. Vol. XLVIII, p. 110. 

Eimer, T., Zur Becherfrage. Virchow’s Arch. 1867. Vol. XL, p. 282. 

Erdmann, Die Resorptionswege in der Schleimhaut des Dünndarms. Dissert,. 
Dorpat, 1867. 

Fries, E., Ueber die Fettresorption und die Entstehung der Becherzellen. Virchow’s 
Arch. 1867. Vol. XL, p. 519. 

Gerlach, L., Ueber den Auerbachschen Plexus mysentericus. Arbeiten aus d. 
physiol. Anstalt. Leipzig. 1872, pp. 102-112. 

Gonjaew, K., Die Nerven des Nahrungsschlauches. Arch. f. mik. Anat. 1875. Vol. 
XI, pp. 479-496. 

Gruby and Delafond, Résultats des recherches faites sur l’anatomie et les 
fonctions des villosités intestinales, ete. Compt. rend. 1843. Vol. XVI, 
p- 1194. 

Grugenhagen, A., Ueber Fettresorption und Darmepithel. Arch. f. mik. Anat. 
1887. Vol. XXIX, p. 139. 

Heidenhain, R., Die Absorptionswege des Fettes. Moleschott’s Untersuchungen, 
1858. Vol. IV, p. 251. 

Henle, J., Symbolae ad anatomiam villorum intestinalium impr. eorum epithelii 
et vasorum lacteorum. Berolini, 1837. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig und 
Heidelberg, 1873-1878. Vol. VI, pp. 412-424. 

Klein, E., Der Darmkanal in Stricker’s Gewebelehre, Article XVI. 

Klein, E., Contributions to the anatomy of Auerbach’s Plexus in the intestine of the 
frog and toad. Quart. Journ. Micros. Sci. 1873. Vol. XIII, p. 377. 

Klein, E., and Verson, E., Der Darmeanal, in Stricker’s Gewebelehre, 1871, 
P- 355: 

Klein, E., Der neue Nervenapparat v. Thanhoffer’s. Centralbl. f. d. med. Wiss, 
1883, p. 82. ; 

v. Kôlliker, A., Nachweis eines besonderen Baues der Cylinderzellen des Dünndarms. 
Verhandl. d. phys.-med. Gesells. Wiirzburg, 1856. Vol. VI, p. 153. 

v. Kôülliker, A., Handbuch der Gewebelehre. 

Lambl, Ueber die Epithelialzellen der Dünndarmschleimhaut. Wiener med. 
Wochenschr. 1859. Nos. 24 and 25. 

Langer, C., Ueber das Lymphgefisssystem des Frosches. Wiener Acad. Sitzungsb. 
1866. Vol. LIII, Pt. I, p. 395. 

Letzerich, L., Ueber die Resorption der verdauten Nihrstoffe im Dünn- 
darm. Virchow’s Archiv. 1866, Vol. XXXVII, p. 232; 1867, Vol. XX XIX, 
P- 435- 

Lipsky, A., Beitrag zur Kenntniss des feineren Baues des Darmcanals. Wiener 
Akad. Sitzungsb. 1865. Vol. LV, Pt. I, p. 183. 


272 THE ALIMENTARY TRACT, ETC. 


Oeffinger, Einige Bemerkungen über die sogenannten Becherzellen. Arch. f. Anat. 
u. Physiol. 1867, p. 337. 

Partsch, C., Beiträge zur Kenntniss des Vorderdarmes einiger Amphibien und 
Reptilien. Arch. f. mik. Anat. 1877. Vol. XIV, p. 179. 

Remak, R., Ueber peripherische Ganglien an den Nerven des Nahrungsrohrs. Arch. 
f. Anat. u. Physiol. 1858, p. 189; also in Zeit. d. Vereins f. Heilkunde in 
Preussen. 1840. 

Renzoni, Osservazioni e ricerche sul epitelio intestinale. Rendiconti dell Acad. di 
Napoli. 1868. 

Rusconi, Riflessioni sopra il sistema linfatico dei rettili. Pavia, 1845. 

Sachs, J., Zur Kenntniss der sogenannten Vacuolen oder Becherzellen im Dünndarm. 
Virchow’s Arch. 1867. Vol. XX XIX, p. 493. 

Schultze, F. E., Das Driisenepithel der schlauchformigen Drüsen des Dünn- 
und Dickdarms und die Becherzellen. Centralbl. f. d. med. Wiss. 1866, 
p- 160. 

Schultze, F. E., Epithel- und Drüsen-Zellen. Arch. f. mik. Anat. 1867. Vol. III, 
p- 145. 

Thanhoffer, L., Beitriige zur Fettresorption und histologischen Structur der 
Dünndarmzotten. Pfliiger’s Arch. f. d. ges. Physiol. 1874. Vol. VIII, pp. 
391-443. 

v. Thanhoffer, L., Ein neuer Nervenapparat im Dünndarm. Centralbl. f. d. med. 
Wiss. 1883, p. 33. 

v. Thanhoffer, L., Antwort auf Herrn Prof, Klein’s ‘Der neue Nervenapparat ete.” 
betitelte Bemerkungen. Centralbl. f. d. med. Wiss. 1883, p. 176. 

Valatour, M. M., Recherches sur les glandes gastriques et sur les tuniques musculaires 
du tube digestif dans les poissons et les Batraciens. Annales des Sci. nat. 4th 
Series, Vol. XVI. Zool. 1861, pp. 219-285. 

Watney, H., The minute anatomy of the alimentary canal. Phil. Trans. 1877. 
Vol. CLX VI, Pt. II, p. 451. 

Wiegandt, Untersuchungen über das Diinndarmepithel. Dissert. Dorpat, 1860. 

v. Wittich, Beiträge zur Frage über Fettresorption. Virchow’s Arch. 1857. Vol. 


XI, p. 37. 


THE LIVER, GALL-BLADDER, AND PANCREAS. 


Barfurth, D., Vergleichend-histochemische Untersuchungen über das Glycogen. 
Arch. f, mik. Anat. 1885. Vol. XXV, p. 369. 

Brotz, J., and Wagenmann, C. A., De amphibiorum hepate et glandularum ductu 
excretio carentium structura deque earundem functionibus experimenta. 
Berolini, 1841. 

v. Brunn, A., Flimmerepithel in den Gallengängen des Frosches. Zool. Anzeiger. 
1883. No. 148, p. 483. 

Eberth, C. J., Die Pigmentleber der Früsche und die Melanämie. Virchow’s Arch, 
1867. Vol. XL, p. 305. 

Eberth, C. J., Zur Kenntniss der Verbreitung glatter Muskeln. Zeitschr. f. wiss. 
Zobl. 1863. Vol. XII, p. 360. 

Eberth, C. J., Ueber den feineren Bau der Leber. Centralbl. f. d. med. Wiss. 
1866, p. 897. 

Eberth, C. J., Untersuchungen über die Leber der Wirbelthiere, Arch. f. mik. 
Anat. 1867. Vol. III, p. 423. 

Eberth, C. J., Untersuchungen über die normale und pathologische Leber. Vir- 
chow’s Arch. 1867. Vol. XX XIX, p. 70. 


LITERATURE. 273 


Eberth, C. J., Ueber die Pigmentleber der Frésche. Virchow’s Arch. 1862. Vol. 
XXIX, p. 70. 

Gerlach, L., Ueber die Nerven der Gallenblase. Centralbl. f.d. med. Wiss. 1873, 
p. 562. 

Hering, E., Ueber den Bau der Wirbelthierleber. Wiener Acad. Sitzungsb. 1886. 
Vol. LIV, Pt. I, p. 335. 

Hering, E., Ueber den Bau der Wirbelthierleber. Arch. f. mik. Anat. 1867. Vol. 
III, p. 88. 

Hering, E., On the liver. Stricker’s Gewebelehre. 1872, p. 429. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig und 
Heidelberg, 1873-1878. Vol. VI, p. 424. 

Jones, C. H., On the structure and development of the liver. Phil. Trans. 1849. 
Pt: L p.122: 

Langley, J. N., On variations in the amount and distribution of fat in the liver-cells 
of the frog. Proc. Roy. Soc. 1886. Vol. XX XIX, p. 234. 

Leydig, F., Lehrbuch der Histologie. 1857. 

Leydig, F., Die Leber der Fische und Batrachier. 

Nussbaum, M., Ueber den Bau und die Thitigkeit der Drüsen (Pancreas). Arch. 
f. mik. Anat. 1877. Vol. XIII, p. 752. 

Popoff, M., The nerves of the gall-bladder (in Russian), Rudneff’s Journ. f. 
normal. u. pathol. Histol., ete. 1872. 

Remak, R., Ueber runde Blutgerinnsel und über pigmenthaltige Zellen. Arch. f. 
Anat. u. Physiol. 1852, p. 115. 

Weber, E. H., Ueber die periodische Farbenänderung welche die Leber der Hühner 
und Früsche erleidet. Bericht von Verhandl. K. Sach Gesell. Leipzig, 
1850, p. 15. 

Zeller, A., Die Abscheidung des indig.-schwefelsauren Natrons in den Driisen 
(Pancreas). Virchow’s Arch. 1878. Vol. LX XIII, p. 257. 


THE SPLEEN. 


Billroth, T., Beïträge zur vergleichenden Anatomie der Milz. Arch. f. Anat. u. 
Physiol. 1857, p. 88. 

Billroth, T., Beitriige zur vergleichenden Anatomie der Milz. Virchow’s Arch. 
1861, Vol. XX, p. 410, and 1862, Vol. XXIII, p. 457; also Zeitschr. f. wiss. 
Zool. 1862, Vol. XI, p. 325. 

Ecker, Blutgefissdriisen, in Wagner’s Handwürterbuch der Physiologie. 1849. 
Vol. IV. 

Gray, H., On the structure and use of the spleen. London, 1854. 

Hoffmann, C. K., Bronn’s Thierbuch. Leipzig und Heidelberg, 1873-1878. Vol. 
VI, p. 509. 

v. Kôlliker, A., Ueber den Bau und die Verrichtungen der Milz. Mittheil. d. naturf. 
Gesell. in Ziirich, 1847. Vol. I, p. 120. 

Kusnezoff, F., Ueber blutkérperchenhaltige Zellen der Milz. Wiener Sitzungsber. 
1873. Vol. LXVII, Pt. III, pp..58-67. 

Miller, W., Ueber den feineren Bau der Milz. Leipzig und Heidelberg, 1865. 

Remak, R., Ueber runde Blutgerinnsel und über pigmenthaltige Zellen. Arch. f. 
Anat. u. Physiol. 1852, p. 115. 

Schweigger-Seidel, F., Untersuchungen über die Milz. Virchow’s Arch. 1862. 
Vol. XXIII, p. 526. 


Stieda, L., Zur Histologie der Milz. Dorpat, 1862. 


rl Ai 


274 THE ALIMENTARY TRACT, ETC. 


THE PERITONEUM. 


Alltmann, R., Ueber die Veränderungen des serüsen Epithels am blosgelegten 
Froschmesenterium. Arch. f. mik. Anat. 1878. Vol. XVI, p. 111. 

Arnold, J., Ueber die Durchtrittsstellen der Wanderzellen durch entzündete serôse 
Haute. Virchow’s Arch. 1878. Vol. LX XIV, p. 245. 

Batelli, A., Dello addaltamento di aleune cellule endotiali nelle membrane serose. 
Lo Sperimentale. 1884, p. 132. 

Cyon, Ueber die Nerven des Peritoneum. Bericht über d. Verhandl. d. Kon. Säch. 
Gesell. d. Wiss. z. Leipzig, 1868. Vol. XX, p.119. Leipzig, 1869. 

Grunau, H., Ueber das Flimmerepithel auf dem Bauchfell des weiblichen Frosches 
und über den Hileiterbau desselben. Dissert. K6nigsberg, 1875. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig und 
Heidelberg, 1873-1878. Vol. VI. 

Hoffmann, T., Die Lungen-Lymphgefiisse der Rana temporaria. Dissert. Dorpat, 
1875. 

Kapff, Untersuchungen über das Ovarium und dessen Beziehungen zum Peritoneum. 
Arch. f. Anat. u. Physiol. 1872, p. 553. 

Klein, E., On Remak’s ciliated vesicles and corneous filaments of the peritoneum of 
the frog. Quart. Journ. Mic. Sci. New Series, 1872. Vol. XII, p. 43. 

Klein, E., On the peripheral distribution of non-medullated nerve-fibres (nerves of 
the peritoneum). Quart. Journ. Micros. Sci. 1872. Vol. XII, p. 32. 

Leydig, Lehrbuch der Histologie. 1857, p. 325. 

Mayer, Ueber die Flimmerbewegung. Froriep’s Notizen, 1836. Vol. XLVII, 
p- 179. 

Neumann, E., Die Beziehungen des Flimmerepithels der Bauchhühle zum Eileiter- 
epithel beim Frosch. Arch. f. mik. Anat. 1875. Vol. XI, pp. 354-377. 

Nicolsky, P., Ueber das Flimmerepithel beim Frosche. Centralbl. f. d. med. Wiss. 
1880, p. 641. 

Paladino, G., Dell’ endotelio vibratile nei Mammiferi ed in generale di alcuni dati 
sulla fisiologia delle formazioni endoteliche. Estr. dal Giornale intern. delle 
Scienze Mediche. 1882. Vol. IV. 

Schweigger-Seidel and Dogiel, Ueber die Peritonealhéhle der Frésche. Arbeiten 
aus d. physiol. Anstalt zu Leipzig. 1866, p. 68. 

Solger, B., Ueber einige Entwicklungsstadien des Peritonealepithels der Amphibien- 
larven. Manusc. d. Naturf. Versamml. zu Freiburg. 1884. 

Thiry, Ueber das Vorkommen eines Flimmerepitheliums auf dem Bauchfell des 
weiblichen Frosches. Güttinger Nachrichten. 1862, pp. 171-174. 

Tourneux, Recherches sur l’épithelium des sereuses. Journ. de l’anat. et de la 
physiol. 1874. 

Waldeyer, Eierstock und Ei. Leipzig, 1870, pp. 72 and 122. 

Wolff, W., Ueber freie sensible Nervenendigungen. Arch. f. mik. Anat. 1882. Vol. 
XX, pp. 377-381. 


THE ALIMENTARY TRACT, ETC. 


I. THE ALIMENTARY TRACT. 


THe alimentary tract consists of the mouth or pharyngo-oral 
cavity, the oesophagus, the stomach, the small intestine and the 
large intestine ; these together forming a tube extending from the 
mouth to the cloaca. From the commencement of the oesophagus, 
at the entrance to the larynx, to the end of the cloaca, the length 
of the tube is about 31°5 em., that of the various parts being : 


From glottis to pylorus 5°5 CM. 
From pylorus to large intestine 22°0 cm. 
Large intestine to end of cloaca 4°0 cm. 


Total length 31°5 em. 


A. The Mouth. 
The mucous membrane covering the tongue will be described 
with the sense-organs (see organ of taste). 


a. General description. The mouth of 2, esculenta, as in all 
other amphibia, with the exception of the lowest (Siren, Proteus, 
etc.), is of considerable width, and extends backwards as far as 
the middle of the tympanic membrane. The upper margin of the 
mouth possesses a lip or fold of the skin (SS'), which projects suffi- 
ciently to prevent the teeth being seen from the front or from the 
sides. This lip-like rim is most prominent in the premaxillary and 
superior maxillary regions, but can be traced along the whole length 
of the upper jaw, and on to the lower jaw, by means of a well- 
marked fold at the angle of the mouth. Beyond this point the lip 
is absent, as the skin is closely attached to the bony mandible. 

On the roof of the mouth the following structures can be made 

T 2 


276 THE ALIMENTARY TRACT, ETC. 


out: immediately within the lip is a deep, well-marked groove, the 
outer boundary formed by the lip, the inner by a fold of the mucous 
membrane (Fig. 178 #); this fold increases from behind forwards 
as far as the premaxillary bones, where it forms two prominences 
(F1, F1) with an interval between. These correspond to the 
palatine processes of the premaxillary bones: immediately behind 
them are openings of the ducts of the intermaxillary glands. 
In the groove so formed are 
placed a single row of simple 
teeth, which, though subject to 
many variations, are usually 
about fifty in number. 

A little further back and to 
either side of the median line 
is a small group of vomerine 
teeth (Vo); each group has from 
five to ten teeth; external to 
these is on each side a trans- 
versely-placed oval opening, the 
posterior nares (Cho). These 


ine Regae Seca eROR TS apertures are directed outwards 
Cho Posterior naris, and backwards into a shal- 
ID Opening of intermaxillary glands. . 
F  Fold of mucous membrane. low groove, bounded anteriorly 
F1, F1 Prominences of mucous membrane. 
Se a ay by a fold of mucous mem- 
0 Floor of the orbit. brane. 
S Lip. 
Sl Lip. According: to Wiedersheim the 

o 

1 Eustachian tubes, 2 : 
Vo Your. mucous membrane immediately 


around the vomerine teeth is 

supplied with taste-bulbs ; the epithelium surrounding these being 
non-ciliated. 14 

The roof of the mouth underneath the parasphenoid is somewhat 

vaulted and on either side depressed by the eyeballs, which project 


downwards more or less prominently (0, 0). Still further back 


are the openings of the Eustachian tubes (Fig. 178 7’), one on 
each side, and almost surrounded by the limbs of the pterygoid 
bones. 

On the floor of the mouth (Fig. 179) the tongue (7, Z1) forms 
the most prominent object; its shape varying according to the state 
of contraction of its muscles. Behind it, in the middle line, is a 
transverse groove (+), corresponding to the posterior border of the 
hyoid bone, and still further back is the opening to the larynx (Z), 


THE ALIMENTARY TRACT. 277 


a longitudinal slit about 3 mm. in length. The mucous mem- 
brane to either side of the tongue is only slightly folded, and 
a little in front of the angle of the mouth is depressed into 
an aperture (5), opening into the vocal sac. This opening is sur- 
rounded by small radiating folds of mucous membrane, and is oval 
in shape. 

Towards the oesophagus the mu- 
cous membrane of both the roof 
and the floor of the mouth is thrown 
into numerous longitudinal folds. 


b. The minute structure of the 
several parts. 


(1) The mucous membrane of 
the mouth. At the junction of the 
skin and the mucous membrane Z 
there is a gradual transition from 
the stratified epithelium of the 
skin to a single layer of colum- 
nar epithelium. On the floor 


The floor of the mouth, 


of the mouth this condition is K Muscles, 
L Opening to larynx. 
reached at the tongue; on the ae . 
root the transition takes place S Che on males only) 
Sm Chin, 
more quickly. The columnar Z Tongue, 
J : 5 Z1 Left cornu of bifid tongue, 
epithelium of the mouth (that of + Folds opposite hinder border of the 
the tongue is excluded from this byoid: 


description) is ciliated ; scattered cells, which are not ciliated, are 
found here and there irregularly, but are not numerous. The 
eylindrical cells are very finely granular in their upper parts, 
clearer in the middle portion, more coarsely and darkly granular in 
their deeper portions ; each cell is possessed of a large, well-defined, 
oval nucleus, which contains one or sometimes two nucleoli. The 
non-ciliated cells usually present a sharply differentiated, structure- 
less, hyaline, free border (Schultze). The epithelium towards the 
margin of the mouth, where it is stratified, is also ciliated. 

Goblet-cells occur in every part of the epithelium, whether cili- 
ated or non-ciliated, and their forms vary very greatly. 

[The submucous layer is a fibrous connective-tissue matrix, 
very rich in nerves and blood-vessels. The capillaries are arranged 
in small, somewhat polygonal meshes (Fig. 180), and are peculiar, 
with those of the anterior part of the oesophagus, in having small 


278 THE ALIMENTARY TRACT, ETC. 


dilatations. This arrangement was first ! described by Langer, and 
later by Schôbl. The dilatations are placed quite irregularly on the 
capillaries, sometimes only on one side, sometimes on both sides of 
the vessel ; a slight constriction occurs at the neck of each dilatation, 
where it opens into the capillary *. The nerves of the mucous 
membrane underneath the orbits have nerve-cells attached to them 
(Stirling and Macdonald, page 170). The lymphatics are very 
numerous, and for the most part follow the course of the blood- 
vessels to their finest twigs, beyond which they follow an indepen- 
dent course (Langer). | 


(2) The teeth are wanting in the lower jaw ; on the roof of the 
mouth they are found in two situations: as a single row in the 
groove within the lip, and a group on each vomer. Each tooth 
has the form of an elongated cone, which in the case of the 
jaw-teeth is curved, in that of the vomerine teeth straight. The 
teeth are fixed to the jaw so as to project upwards and slightly in- 
wards, those at the front of the mouth projecting backwards, and 
those on the vomers project backwards. Each tooth has a small, 
sharp projection, or secondary crown on its outer surface (Fig. 181), 
placed near the mucous membrane. The teeth are fixed to the 
bones by means of Crusta petrosa, which is again united to the bones 
of the mandible by a matrix of spongy bone, continuous for the 
several teeth. Between the tooth and the mucous membrane is a 
layer of flattened epithelium (//), which extends more deeply on the 
inner side of the tooth than on the outer; the layer is continuous 
with the epithelium of the mouth, and is two to three cells in 
thickness. Each tooth has fine longitudinal grooves on the basal 
part of its outer surface, and consists of two parts, a crown and 
a root. The teeth possess large cavities, the wall being thin and 
almost of even thickness, except on the inner surface of the basal 
portion of the root, where the wall is wanting, and so forms a 
large aperture to the root. 

The general skeleton of the tooth is formed of dentine, this is 
covered on the crown by a layer of enamel, and the Cuticu/a dentis 
on the socket by a layer of Crusta petrosa. 


' Beale, Phil. Trans., 1863, p. 153, shows dilatations in his drawing, but makes no 
reference to them in the text. 

? The vascular supply of the mucous membrane of the dorsal surface of the mouth 
and oesophagus is shown (after Schübl) in Plate IT, Fig. 180, I. Arteries red, veins 
blue. II. in the same figure represents the dilatations on the capillaries; after 
Schobl. 


sim a El 


THE ALIMENTARY TRACT. 279 


a. The dentine is a homogeneous substance pierced by numerous 
tubules (1), which arise at the pulp-cavity and course in a parallel 
direction to the surface of the 
dentine, where they form a 
rich network with irregular, 
interglomerular spaces. The 
inner surface of the dentine 
is rough, through the presence 
of numerous small, dark 
tubercles. 


Fig. 181. 


B. The enamel covers the 
dentine on the apical portion 
of the tooth. It has tubes 
coursing through it, which are 
continuous with those of the 
dentine, and presents also 
circumferential striations (Fig. 
nor JIT). 

y. The tooth cuticle (Cuti- 


cula dentis) 1s colourless and I. Transverse section of the premaxillary bone to 
show attachment of the teeth ; after Hertwig. 


covers the enamel. It is : Magnified 22 times. 
highly refractive, very trans- id Dentine and enamel ; after Hertwig. Magnified 
500 times, 


parent, and very resistant to LIL. Enamel: after Hertwig. Magnified 500 times. 
A Blood-vessel of the pulp-cavity. 


chemical reagents. From the ANT AE à 


apex, towards the Crus/a DA DER 
5 "i È F Processus dentalis. 
petrosa, it thins very rapidly, H Layer of epithelium. 
2 © 5 O Tooth cuticle. 
but is continued sufficiently Unes 


far to cover a portion of the 5 dieu 
X Cutaneous glands. 
Crusta petrosa. 

6. The Crusta petrosa resembles bone, except that it contains no 
Haversian canals ; it possesses cells which resemble bone corpuscles, 
and are usually somewhat rounded or oval and communicate with 
each other by their processes ; for the most part it is homogeneous 
and free from cells (Hertwig). 

e. The pulp-cavity contains a connective-tissue very rich in 
cellular elements; those cells adjacent to the dentine are arranged 
in a layer (Membrana eboris) which has somewhat the appearance of 
a layer of epithelium. The cells (odontoblasts) of this layer are 
spindle-shaped, and send processes (dentinal fibres) into the dentinal 
tubules. A small blood-vessel can be traced into each cavity, but 
as yet no nerve has been found in the pulp-cavities. 


280 THE ALIMENTARY TRACT, ETC. 


[Smith (/. ¢.) has, after careful investigation, come to the 
conclusion that the teeth of R. esculenta and À. temporaria are 
practically alike, therefore the methods of differentiating the two 
species by means of the teeth, as given by Leydig, are not to be 
relied on. | 


(3) The intermaxillary glands (G/andula intermarillaris) consist 
of a mass of convoluted tubes, lying chiefly between the pre- 
maxillary bones and the capsule of the nose, and opening by about 
twenty to twenty-five ducts at the fore-part of the mouth (Fig. 
178 ID). A portion of the glands extends high into the nasal 
cavity (Born), while dorsally another portion lies under the skin 
and the WM. dilatator and 7. lateralis narium, which together act as 
compressors to the subjacent glands : a small, elastic, cartilaginous 
rod, placed between the anterior margin of the nasal capsule and 
the under surface of the ascending limb of the premaxilla, opposes 
these muscles on either side by its spring-like action (Wiedersheim). 

In a fresh skull the openings of the ducts can easily be seen 
after washing away the mucous secretion ; they are, however, seen 
to better advantage by treatment with Müller’s fluid and subsequent 
staining with carmine. With sufficient magnifying power, they 
are then seen as a row of bright dots. The tubules are of uniform 
thickness, placed closely side by side, and surrounded by a nervous 
plexus, which contains numerous branching nerve-cells. The epi- 
thelium of the tubules is cylindrical, with a rounded, finely granular 
nucleus ; processes from the peripheral ends of the cells are con- 
tinued to a Membrana propria. The ducts are lined with columnar, 
ciliated epithelium. 


The secretion of the glands is remarkably adhesive, and is wiped 
off by the tongue when it is projected; by this means the tongue 
becomes a particularly efficacious instrument for capturing prey. 
The glands are, both histologically and chemically, pure mucous 


glands. In urodeles the homologous glands are placed in the hollow — 


septum of the nose, between the nasal cavities. 


(4) The tongue (Figs. 179, 182, 183) is a broad, fleshy flap on 
the floor of the mouth, to which it is attached by the anterior half 
of its ventral surface as far forwards as the chin. Seen from above 
it has a wedge-like form, being narrow in front and wider behind, 
where it is prolonged at each angle to form two cornua. 

By raising the tongue one obtains a view of a portion of the 


THE ALIMENTARY TRACT. 281 


M. hyoglossus. The two MM. hyoglossi arise (see page 66) some 
distance apart, and run forwards and towards each other to meet 
on the ventral surface of the hyoid bone ; they now assume a lon- 
gitudinal direction, and course forwards parallel to each other until 
they reach the IM. genio-glossus (Fig. 182 @). Each muscle now 
divides to form coarse bundles, which ascend on either side of the 
M. genio-glossus towards the dor- 
sum of the tongue. In this course 
they are encircled by a strong, 
elastic, connective-tissue sheath. 
The sheath is incomplete at the 
hinder end of the 17. genio-glossus, 
where it possesses rounded aper- 
tures, through which the glosso- 
pharyngeal nerves (W, N) disap- 
pear, to be distributed, after a 
sharp curve backwards, in the 
substance of the organ. 


Fig. 182. 


The J. genio-glossus arises, in 
two parts on either side, at the 
side of the chin. One part (Fig. 
182 G) is dorsal and median, the 
other (Fig. 182 G1) ventral and Muscles of the tongue, seen from the ventral 
external. re 


G Median portion of M. genio-glossus. 


The first part, with its fellow 2 ae porperer Me sense 
‘ : yoid. 
of the opposite side, forms an Hy M. hyoglossus. 
. é : L Larynx. 
arched commissure in the form of M Mandible. 
muscular rings, which decrease in OR es ra sa eee 


size from before backwards, and so form a pear-shaped mass: the 
second, external portion, extends backwards, with a slight obliquity, 
as a thin, fan-like expansion, to the mucous membrane, where it is 
inserted. This arrangement can easily be seen after dissecting 
away the sheath (Fig. 183 //y); the hindermost fibres curve sharply 
into the tongue (//y'); the anterior fibres pass obliquely forwards 
and blend with the straight fibres of the dorsal portion of the 
M. genio-glossus (Fig. 183 Gy). The arcuate fibres of the 17. genio- 
glossus pass, for the most part, upwards and outwards to the tips of 
the posterior bifid border of the tongue; in this course they lie as 
a rule above the A. Ayoglossus, but here and there the two muscles 


intermix (Fig. 183 Gy!), and it is by no means easy to separate 
them. 


282 THE ALIMENTARY TRACT, ETC. 


The M. hyoglossus is the retractor 
of the tongue, the J/. genio-glossus 
the protractor. 

(For mucous membrane of the 
tongue, see organ of taste. The 
vocal sacs are described with the 
organs of voice and respiration.) 


B. The Oesophagus and Stomach 
(Figs. 184, 185, 189, 194, 195, 
199). 

a. General description. The 
oesophagus is not separated from the 
pharyngo-oral cavity by a sharp line 
of demarcation. It has a length of 


Muscles of the tongue, from the ventral 


surface. only a few mm. in medium-sized 
G M. genio-glossus. er ° : s 
Gg stan fibres of the M. genio-glossus. frog 8 (Fig - I 84 Oc) ) and hes in the 


GA Curved fibres of the M.genio-glossus. middle line of the body, supported 
oe spook la ranean on either side by the cornua of the 

hyoid bone. The oesophagus lies on 
the dorsal wall of the larynx, is smooth externally, and is thrown 
into well-marked longitudinal folds internally. 

The transition from oesophagus to stomach is somewhat indefi- 
nitely marked by a slight dilatation of the tube, often scarcely per- 
ceptible, still it can always be recognized by an abrupt curvature to 
the left (Fig. 184 J/), which becomes more prominent when the 
stomach is distended. Externally the stomach is seen as an elon- 
gated, shghtly curved cone, smooth externally and of equal diameter 
throughout. 

The oesophagus and stomach are held in position by folds of 
peritoneum (mesentery), which attaches them to the dorsal wall of 
the abdominal cavity, to the lungs, pericardium, and liver; and by 
the blood-vessels. 


b. Minute structure. The walls of these viscera are composed 
of four layers or coats. 


(1) The serous coat (Fig. 186) is a layer of endothelium, lying 
on a very thin stratum of connective-tissue; the whole derived 
from the peritoneum, which encloses the organs. | 


(2) The muscular coat (Fig. 186 ZM and 7) is arranged in 


EE 


THE ALIMENTARY 


two layers, one (ZA) longitu- 
dinal, the other (7'J/) trans- 
verse. The longitudinal layer 
is thicker in the oesophagus, 
and thins as it is continued to 
the pyloric end of the stomach. 
The circular layer, on the other 
hand, gains in thickness ; both 
layers are of unstriated mus- 
cular fibre. 


(3) The submucous coat 
(Fig. 186 À, B, and SI) is 
better developed in the stomach 
than in any other part of the 
alimentary canal. Itis formed 
of a wide-meshed, loose con- 
nective-tissue, which supports 


numerous blood-vessels and 
lymphatics. Towards the 
mucous coat it possesses a 


well-differentiated Museularis 
mucosa, Which is arranged in 
two layers, a longitudinal (2) 
and a transverse (4). 


(4) The mucous coat is pos- 
sessed of numerous tubular 
glands, which vary in structure 
according to the part of the 
membrane examined. They 
have been the subject of much 
investigation (Heidenhain, 
Nussbaum, Partsch, Langley, 
and others), and are best de- 
scribed in three groups: those 
of the oesophagus, of the first 
part of the stomach, and of 


A 
Cl 
D 
Du 
AB 


Mz 
Oe 
Py 
R 

+ 


TRACT. 283 


The alimentary canal. 


Opening of large intestine into cloaca. 
Cloaca. 

Small intestine. 

Duodenum. 

Urinary bladder. 

Stomach. 

Spleen. 

Oesophagus. 

Pylorus. 

Large intestine (rectum). 

Junction of small and large intestine, 


the pyloric end of the stomach respectively; between each pair of 


groups are transitional forms. 


a. [The oesophageal glands are complete tubular glands lined 
by a single layer of epithelium, which very closely resemble the 


284 THE ALIMENTARY TRACT, ETC. 


glandular cells of the fundus of the stomach (Plate II, Fig. 187). 
The cells are conical or cylindrical, the protoplasmic contents 


Fig. 185. 2 


The abdominal viscera of Rana esculenta (female). 


Il Right lobe of liver. 
I2 Middle lobe of liver. 
Ig Left lung. 


D Small intestine. 
Du Duodenum, 


EE Ovaries. À 
H Heart. Lg! Right lung. 
HB Urinary bladder. M Stomach. 


L Left lobe of liver, 


granular, the granules being larger than those of the corresponding 
cells in the stomach (Langley). Mucous cells are found among 
the true secretory cells. The cells of the ducts are sometimes, 


but rarely, ciliated (Langley).] 


THE ALIMENTARY TRACT. 285 


8. [The glands of the fundus of the stomach! are not so complex 
as the typical glands of the oesophagus. The cells at the mouth 
of the gland are continued 
into fine processes (Fig. 187), 
and their outer parts contain 
mucigen. The cells of the 
neck of the gland are more 
cubical, and towards the 
lower part of the neck are 
mucous cells. The cells of 
. the body of the gland are of 
irregular shape, and so placed 
that the nucleus of one cell 
faces the junction of two 
cells on the opposite side 
(Langley). These cells are 
very finely granular.] 


HR 

y. [The glands of the py- 
lorie end of the stomach have 
been compared with the 
mouths and necks of the 
glands of the fundus (Partsch, 
Langley). The cells are of 
two kinds only (Fig. 188). Hine 
The cylindrical cells of the z LM 
surface of the stomach are Tiumenestion through on of the engine 
continued into the gland, general arrangement of the RES H. 
where they become shorter” % rongitadimal layer of muscularis macosse 
and sub-cubical; these form ZW Longitudinal muscular coat. 

M Mucous membrane. 

the greater part of the SM Submucous coat. 
Pome he cells, at. the. |. 
deepest portion of the gland are more rounded, and resemble the 
mucous cells in the neck of the glands of the fundus. | 

6. [Between these well-marked groups of glands are various 
transitional forms. The transition from oesophageal to gastric 
glands is not a continuous one, as glands resembling those of the 
stomach can be found nearer the oesophagus than other glands, which 


! A transverse section through the mucous membrane of the fundus of the stomach 
of Rana esculenta is shown in Plate II, Fig. 187. Alcohol preparation, doubly 
stained with carmine and anilin blue, After Biedermann. (Obj. II, Syst. 7, 
Hartnack.) 


286 THE ALIMENTARY TRACT, ETC. 


more nearly resemble oesophageal glands. At the same point the 
mucous membrane is thinner than either in front or behind. In 
the same way an intermediate zone exists 
between the typical glands of the fundus 
and pylorus of the stomach. | 


In both oesophagus and stomach the 
mucous membrane is thrown into longi- 
tudinal folds when the organs are empty. 
The epithelium of the surface of the 
oesophagus is mostly ciliated, and possesses 
numerous goblet cells; according to Klem 
the cells are not set vertically on the sub- 
jacent submucosa, but obliquely. 

[The epithelium of the surface of the 
stomach is, at least in part, ciliated (Re- 
Transverse section through the géczy, Trinkler, and others), and has nu- 


mucous membre f tk = = 
Hd of the stomach merous goblet-cells (Schultze, Heidenhain, 


ca tgs cat re Bleyer, Eimer, Oedmonson, and others).] 

HATNBAE:} (5) [The nerves of these organs, accord- 
ing to Gonjaew, contain both medullated and non-medullated fibres, 
which have nerve-cells attached to them. From these fine branches 
pass, either with the blood-vessels or alone, to the mucous coat, 
losing their medulla on the way. In this course they inosculate 
very freely, and are then distributed as very fine, beaded fibrils to 
the glands and epithelium, which are very richly supplied. | 


(6) [The blood-vessels and lymphatics very closely resemble the 
corresponding structures in the smal] intestine (p. 290) ; the blood- 
vessels form a rich anastomosis in the submucous membrane; the 
lymphatics are arranged in two systems, one under the serous coat, 
and a larger system in the mucous and submucous coats. The 
oesophagus lies free in a peri-oesophageal lymph-sac (Robinson). | 


C. The Small Intestine. 

a. General description. The small intestine commences behind 
the middle of the abdomen at the pyloric end of the stomach, from 
which it is marked off by a slight constriction. The first portion 
of the small intestine is the duodenum (Figs. 184 and 194 Du); by 
means of an abrupt turn it winds directly forwards, parallel to the 
long axis of the stomach; the pancreas is placed in the loop so 
formed. 

The whole of this portion of the intestine, together with the 


THE ALIMENTARY TRACT. 287 


greater part of the stomach, is, in the normal condition, under cover 
of the liver (Figs. 185, 194): while under the liver the intestine 
is firmly attached to the deep surface of that organ by a short 
but strong Ligamentum hepato-duodenale; it then turns suddenly 
backwards, increases in size, and by means of numerous convo- 
lutions occupies a considerable portion of the right half of the 
abdomen (Fig. 184 D). It is held in position by a well-developed 
mesentery. 


b. Minute structure. Like other portions of the alimentary 
canal, the small intestine is formed of four layers :— 

(1) The serous coat presents no peculiarities ; 1t consists simply 
of a layer of endothelial cells, with a small amount of sub-endothe- 
hal connective-tissue. 

(2) The muscular coat is in two layers, the outer longitudinal 
layer being very thin, the inner circular layer thick. 

(3) The submucous layer resembles that of the stomach, but is 
not so thick ; the muscu/aris mucosae is well developed and arranged, 
as in the stomach, in two layers. 

(4) The mucous coat (Fig. 189) is thrown into folds, which differ 
in various parts of the tube. 

The longitudinal folds of the stomach are compressed together 
towards the pyloric end of the stomach (a) and diminish in size ; at 
the commencement of the duodenum they end abruptly (a'), but 
without any indication of a valvular arrangement. 

Immediately beyond the pylorus the mucous membrane is folded 
so as to form an irregular network of folds which inclose irregular 
alveoli; the folds are thicker on the concave surface of the duo- 
denum, and form a longitudinal ridge (4); im this ridge the 
alveolar spaces are much smaller than those to either side. The 
irregular folding extends through two to three cm., when a more 
regular arrangement commences in the form of two adjacent series 
of transverse folds (e, c!). Each fold is semi-lunar in shape, with 
the convexity attached to the wall of the tube and directed forwards, 
while the concave free border and pocket-like space enclosed are 
directed backwards. 

The arrangement of these folds reminds one of the semi-lunar 
valves of the human heart, and probably one of their functions is 
to prevent the regurgitation of the chyme (Wiedersheim). 

The correspondmg valves of opposite sides meet at each end at 
an angle, the apex of which is directed away from the stomach. On 


288 THE ALIMENTARY TRACT, ETC. 


these folds and between them are smaller, 

secondary folds, partly irregularly arranged, 

partly longitudinal (4 d). 

Towards the middle of the small intestine 
this valvular arrangement is lost, to be replaced 
by an irregular net-like folding; beyond this 
longitudinal folds arise; which proceed in a 
sinuous course towards the large intestine. 

The whole mucous membrane, both on the 
folds and otherwise, is covered with a simple 
layer of columnar epithelium, which is con- 
tinued into numerous simple follicles (glands 
of Lieberkühn) found throughout the mucous 
membrane of the small intestine. The cells 
Mucous membrane of the gre placed on a basement membrane, which 

pyloric end of the stomach 3 à a 

and the duodenum. rests on a thin layer of loose connective-tissue, 

a Mucous membrane of intervening between the epithelial coat and 
the stomach. ey x ; 

at Commencement of the muscularis mucosae. The epithelial cells 
duod és . . . 

b Duodenal mucous Are intermixed with a large number of goblet- 
membrane arranged cells, and have between them fine processes 
in irregular net- , 5 > 
work, from the connective-tissue corpuscles of the 

€ y Semi-lunar folds of the biacent laver: f thes 3 

CL) mucous membrane. su Jacen ay er ; many 0 NESE processes 

d Longitudinal folds of extend to or even beyond the free margin of 
the mucous mem- ‘ : si 
brane. the epithelial cells. 

The individual cells are columnar, possessed 
of a well-marked cell-wall, and have distinct, large, oval nuclei, 
containing one or more nucleoli. The protoplasmic contents are 
granular, and with proper treatment show a very distinct intra- 
cellular network. The free margins of the cells are sharply marked 
off from the cell-contents, and are more firmly attached to the cor- 
responding: portions of adjacent cells than the rest of the cell-wall. 
This margin has a longitudinal striation, which owing to the im- 
portant function performed by this part of the intestine, namely, 
absorption of the fat, has been the subject of many important 
investigations. 


[In the following brief summary of the earlier researches on the minute structure 
of the intestinal epithelium, in which the intestine of the frog was chiefly used, the 
memoirs in which these investigations are recorded are referred to in the order of 
time. 


1837. Henle first described the border as a thickened, highly refractive portion 
of the cell-wall. 


1855. Külliker and Funke, after independent research, described the longitudinal 


THE ALIMENTARY TRACT. 289 


striation : Funke offered no explanation of the fact, while Külliker considered it due to 
the presence of fine tubules. Later Funke gave a modified support to Kolliker’s view 
by admitting the presence of tubules around the circumferential part of the border, 

1856. Donders gave a description corresponding with that of Henle. 

1857. Brettauer and Steinach gave it as the result of their investigations that the 
border was composed of closely-applied fine rods: v. Wittich first. showed that the 
borders of adjacent cells were more firmly attached than the rest of the cell; he 
admitted the presence of apertures, but considered the whole appearance to be due 
to post-mortem changes. 

Welcker and Friedreich agreed with the views of Brettauer and Steinach, but 
traced the striation throughout the length of the cells, in fact traced the tubules to 
the connective-tissue below. 

1858. In this year Heidenhain published his results; he held the striation to be 
due to the presence of fine rods, and was the first to show that processes of the con- 
nective-tissue corpuscles passed up between the epithelial cells; he found fat globules 
in the epithelial cells, in the connective-tissue, and in the lacteals. 

Friedreich described the striation as continued through the whole length of the 
cells, and as due to tubules. 

1859. Lambl denied the presence of the rods, and considered the whole phenomenon 
an optical appearance due to the cell-wall; in this view he was supported by Vlako- 
vich of Padua and Amici of Florence. 

1860. Wiegandt held the border to be an independent covering, and the striation 
to be due to folding or wrinkling. 

Col. Balogh described the border as formed of rods, but denied that these existed 
except when brought about by the action of fats; in support of this view he showed 
that the striation was wanting when fat was absent. 

1865. Lipsky held the border to be composed of rods. 

1866. Henle described the cells as in his former work, but now held the border 
to be composed of rods, in fact to represent a ciliated border. 

1867. Erdmann described the border as being of two layers, an upper, thicker 
layer, with both longitudinal and transverse striation, and a lower, thinner layer, 
the true cell-wall. The upper layer he described as capable of splitting in the di- 
rections of both striations, 

Schultze described the border as not being in intimate connection with the proto- 
plasm of the cell. Arnstein and Wiegandt supported Heidenhain’s description. 

1868, Albini e Renzoni described the part as resembling resting cilia. 

1869. Eimer traced fat-globules into all the parts, epithelium, connective-tissue, and 
vessels; and held that the fat could pass from a lacteal to a branch of the Vena porta. 

1870. Heidenhain, after further investigation, supported his earlier views. 

1874. Thanhoffer described the membrane as perforated, and the protoplasm of the 
cells as actively sending protoplasmic processes through these apertures ; this he had 
seen in frogs in which all connection with the spinal nerves had been severed. 

1875. Benjamins could not find the striation to be a constant occurrence, and failed 
to find the processes described by Thanhotfer. 


1876. Krause found rod-like bodies round the margin of the border. 
1877. Fortunatow supported Thanoffer’s view. 


1881. Landois observed appearances in Spelerpes fuscus, which led him to sup- 
port Thanoffer’s views. 

1883. Wiedersheim supported Thanhoffer’s views. 

1884. Wiemer supported Thanhoffer’s observations. 

1888. Paneth failed to find any contractile protoplasmic processes, and asserts that 


the circumference of the border, when examined under certain conditions, is com- 
posed of rods. 


From the same causes the goblet- or chalice-cells, already mentioned, have been 
the subject of much speculation and investigation, 
1846, Frerichs drew and described these cells as empty cells, 
In 1848 these cells were first described as epithelium capitatum by Gruby and 
Delafond. 
U 


290 THE ALIMENTARY TRACT, ETC. 


In 1856 Donders described the cells as being open, and as discharging their contents 
into the canal; the cell-walls being then pressed together by the neighbouring cells, 
and the cell-contents being then gradually reformed. 

In the same year Külliker published results closely agreeing with those of Donders, 
and he traced the various stages of the process. 

1857. Brettauer and Steinach held them to be cells which had lost their contents, 
and as the ‘cuticular border’ was absent, concluded that the cell-contents were in 
closer connection with the ‘ border’ than with the rest of the cell-wall. 

1865. Lipsky and Sachs both doubted the presence of such cells, and considered 
them due to the action of reagents or post-mortem change. 

1866. Letzerich described the cells as open, and regarded them as the commencement 
of the lacteal system, while Dünitz thought the whole appearance due to reagents. 

1867. Schultze and Eimer, independently, described them as unicellular glands. 
Erdmann, however, again denied their occurrence under normal conditions. 

Oeffinger held the goblet-cells to be modified ordinary cylindrical epithelium cells ; 
in which view he was supported by Arnstein. 

1868. Schultze and Eimer, after renewed investigations, reiterated their former 
opinions. ; 

1869. Eimer described the goblet-cells as secreting mucin, and as capable, by 
division, of throwing out pus-like cells. 

1876. Krause described the cells as containing granular contents, which under 


certain conditions are thrown out. 

1877. Tolldt considered them artificial productions. Edinger asserted that they are 
formed from the cylindrical cells. 

1877-1885. Partsch (1877), Klein and Hebold (1879), Stéhr (1880), Patzelt (1882), 
Haller (1883), Holl (1885), support the last view. 

1878. Hoffmann supported Schultze’s views. 

1886. List describes these organs as unicellular mucous glands. 

1887. Paneth described them as secreting mucous and as being derived from the 
cylindrical cells. ] 


(5) [The blood-vessels of the small intestine (p. 234) have been 
described by Langer; he finds the vessels arranged in networks, 
one a subserous network, placed underneath the serous coat, and 
formed of elongated, irregular, four-cornered meshes. When the 
intestine is distended the meshes are rectangular. 

The vessels to the mucous membrane divide and anastomose very 
freely in the submucous layer, and then form an irregular network 
on the inner surface of the Muscularis mucosa; this network follows 
all the foldings of the mucous membrane, and thereby supplies a 
double layer to each villous fold of the mucous membrane. The 
meshes are usually four-sided or five-sided. | 

(6) [The lymphatics of the small intestine (Figs. 190,191). The 
lymphatic vessels on reaching the intestine usually bifurcate ; the 
two branches, as a rule, follow and enclose an arterial twig. From 
the serous layer they receive the contents of a very fine lymphatic 
plexus, the lumens of which are slightly greater than that of the 
corresponding’ capillaries ; from the mucous layer they receive the 
contents of the lacteals: between these two layers the lymphatics 
anastomose very freely by means of numerous branches (Langer). 

The lacteals are lined with an epithelioid layer and traversed by 
connective-tissue trabeculae, which have a like covering. The 


THE ALIMENTARY 


TRACT. 291 


lacteals are not simple but in the form of a coarse network (Fig. 


189), (Langer). | 

(7) [The nerves of the 
small intestine (p. 200) usu- 
ally follow the arteries to 
the muscular coats, between 
which they form a plexus 
(Auerbach’s plexus); from 
this numerous twigs are 
given off, which course alone 
or in company with vessels 


to the mucous coat, where  rsolated fold of mucous membrane of small intestine 


a second plexus (Meissner’s 
plexus) is formed. Auerbach’s 


of Rana temporaria; after Langer. Forty times 
natural size. 


Blood-vessels striped, lacteals shaded. 


plexus, according to Klein, consists of bands of nervous fibrils in 
endothelial sheaths ; they branch and inosculate, and thus form a 


plexus. Where several such branches 
meet, a more or less complicated decus- 
sation of the bands of fibres takes place. 
Along these nervous bands are ganglion 
cells, either isolated or in groups. The 
cells are large, generally spherical, and 
contain a sharply outlined nucleus with 
a single or double nucleolus. The 
smaller cells generally appear to possess 
only one process, which can be traced 
from the protoplasm of the cell between 
the fibrils of the nerve-trunk. The 
larger cells are distinctly multipolar, 
their protoplasm being provided with a 
number of fine processes, or, as is 
oftener the case, with one large and 
several small processes. In many in- 
stances Klein was able to distinguish 
around the ganglion-cells a capsule of 
a spherical. or ovoid shape. In these 
cases the body, as well as the processes 
of the ganglion-cell, were lying within 
the capsule. This system of ganglion- 
cells is in connection with the individual 
bundles within the nerve-trunks. 


Transverse section of a fold of the 


mucous membrane of Rana tempo- 
raria ; after Langer. Sixty times 
natural size. 
A Lacteals with transverse trabe- 
culae, 
B Circular muscular layer. 
C Longitudinal muscular layer, 
Blood-vessels striped. 


292 THE ALIMENTARY TRACT, ETC. 


Klein describes a second system of ganglion-cells, situated in 
meshes, which are formed by the nerve-trunks of the plexus itself. 
These ganglion-cells are much larger than the former, and are 
multipolar ; their protoplasm, which is distinctly fibrillar, with 
granules between the fibrils, is provided with one or two long, thick 
processes and several short and thin ones; generally the processes 
are branched. The general shape of the cells is oblong, the thick, 
long processes being commonly at the two opposite poles. The 
cells are generally isolated, sometimes situated in the centre of a 
mesh, or more commonly near a nerve-trunk that borders the mesh 
on one side. Each ganglion-cell 
is connected with a nerve-trunk 
of the plexus by at least one 
process. In a few of the nerve- 
trunks of the general plexus, iso- 
lated medullated nerve-fibrils are 
seen to pursue an almost straight 
course from one trunk into 
another and divide into two. 
There is no connection between 
these medullated fibres and the 
ganghon-cells. 


Auerbach’s plexus is a much 
finer plexus than that just de- 
scribed, and the ganglia are much 
smaller. It supplies twigs to 
the Muscularis mucosa; these break 
up into fine fibrils, which follow 
the direction of the muscle-fibres ; 
other twigs supply the blood- 
vessels, with which they can be 
From a transverse section of the large intestine traced into the bases of the folds 

of Rana temporaria, moderately distended. of mucous membrane. Thanhoffer 


—G. H. : 
has recently (/. -.) described nerve- 
A Denser portion of submucous coat. fibrils, which terminate in the 
B Looser portion of submucous coat. : ' 2 . 
CU Artery, cut obliquely. mucous epithelium. | 
D Cireular muscle-layer. 
E Longitudinal muscle-layer. D: The Large Intestine (Fig. 


184 À). 


a. General description. The large intestine is a.flask-shaped | 
viscus, lying in the median line. The small intestine opens into it 


THE ALIMENTARY TRACT. 293 


by an abrupt curve at its anterior end. The large intestine is the 
widest part of the alimentary canal, is thin-walled, and diminishes 
in width towards its hinder end, where it opens into the cloaca 
above the opening of the bladder. 


b. [Minute structure. 
(1) The serous coat resembles that of the small intestine, ete. 


(2) The muscular coats resemble those of the small intestine, but 
are thinner; the longitudinal layer is, however, proportionally 
thicker (Wiedersheim). 

(3) The submucous coat (Fig. 192) resembles that of the small 
intestine im its general structure; the portion lymg immediately 
beneath the mucous membrane (/) is denser in structure. 

This layer has no Muscularis mucosa. 


(4) The mucous coat (4) is a simple layer of large, columnar, 
epithelial cells, with large oval nuclei. The cells have a hyaline 
free border, but this possesses no stri- 
ation. The mucous membrane is usually 
described as possessing’ numerous simple 
follicles (glands of Lieberkühn); in 
those specimens which I have exa- 
mined they have been entirely absent 
(Figs. 192, 193). At six to eight 
pomts in a transverse section of a 
rectum moderately distended the sub- 
mucous coat is thinner, and so throws the 
mucous coat into slight, longitudinal 
grooves; but these do not in the least 
resemble the glands of Lieberkiihn. 


Fig. 193. 


(5) The epithelium possesses goblet- 
or chalice-cells (Hoffmann), the number 
of which probably depends upon 

À Transverse section of large intestine of 

the period of the year and the state Kana esculenta; the mucous mem- 
, * sa brane thrown into longitudinal folds 

of digestion. inithe> rectum) “from ~~. ousssaones of the organ being 
which the section for the figures 192 contracted. Arteries injected with 

= carmine.—G. H. 
and 193 were cut, not one goblet-cell A Large circular vessels within the 
was found in a complete series of Re re 

5 B Fine anastomosis to the mucous 
sections. coat. 

If the rectum be contracted, the mucous membrane is thrown into 


longitudinal folds. 


294 THE ALIMENTARY TRACT, ETC. 


(6) The blood-vessels (Fig. 193) have a simple arrangement. 
The arteries are large, and form oblique loops around the intestine, 
lying under the peritoneum ; from these branches are given off to 
form a series of rings in the submucous membrane (Fig. 193 À); 
from these fine twigs are given off to form a fine anastomosis under 
the mucous membrane (P). 


(7) The lymphatics of the large intestine are arranged in two 
chief systems : one under the serous coat resembles the corresponding 
system of the small intestine. The second set forms a network of 
rounded loops in the submucous coat, which give rise to a secondary 
set of smaller vessels towards the mucous membrane ; this secondary 
system forms a sort of trellis-work standing on the rounded loops, 
and so maps out small blocks of the thick submucous coat. Towards 
the cloaca the arrangement is simpler; the secondary lymphatics 
are lost, while the primary lymphatics tend to form elongated, 
longitudinal loops (Langer). | 


IL THE GLANDS CONNECTED WITH THE 
INTESTINAL CANAL. 


A. The Liver and Gall-bladder. 
a. External form. 


(1) The liver (Figs. 185, 194) is a large, reddish-brown organ, 
occupying a large part of the anterior abdominal region. It con- 
sists of three or more lobes, which present many individual varia- 
tions ; as a rule there are two larger lateral lobes (Z and Z1), and 
a smaller median lobe (Z?). Each lobe has a superficial or ventral 
surface, which is convex, and a deep or dorsal surface, which is con- 
cave and directed towards the other abdominal viscera lying above 
the liver. The two surfaces of each lobe meet to form a sharp 
border around the lobe, except where the three lobes are more 
intimately attached, opposite the apex of the heart (Figs. 185, 
194); at this place each lobe possesses a small, flat, or slightly 
concave anterior surface. i 

The left lobe (Z) hides the greater portion of the stomach, and 
has near its inner border a deep fissure, which runs forwards and 


GLANDS CONNECTED WITH THE INTESTINAL CANAL 295 


so marks off a more or less well-marked fourth lobe. The 
anterior portion of the left lobe is attached to the corresponding 
portion of the right lobe by a narrow commissure. 


The median lobe (£7) ex- 
tends backwards as far as the 
pylorus, and covers the com- 
mencement of the intestine 
together with the pancreas ; 
these organs can, therefore, 
not be seen until this lobe 
is displaced. A fifth lobe is 
sometimes found on the dorsal 
surface of the median lobe, 
and to it or to the dorsal sur- 
face of the median lobe the 
small intestine is attached by 
the Ligamentum hepato-duode- 
nale (Fig. 195 Lkp). ‘The 
Vena portarum enters the liver 
behind this ligament. 


The liver, seen from the ventral surface. 


Du Duodenum. 


The right lobe extends much H Heart. 
L Left lobe of liver, 
further dorsalwards than the T5 Beet tote of liver. 


L2 Middle lobe of liver. 


left lobe, and even comes in 
M Stomach. 


contact with the lung, the 

vessels of which sometimes indent its surface in spirit specimens. 
This lobe is also in contact with the base of the fat-body, and in 
females with the oviduct. 

By drawing the lobes of the liver to either side and displacing 
the heart towards the head, the posterior caval vein is seen passing 
from the liver to the heart, and the hepatic commissure joining the 
lateral lobes is brought into view. 


(2) The gall-bladder (Fig. 195 G) is placed on the dorsal surface 
of the liver in the deep niche between the right and left lobes ; it 
is attached to the liver by connective-tissug and peritoneum. 

The gall-bladder is round or oval in form ; when moderately full 
it has a smooth, outer wall, which is thin and allows the green colour 
of the bile to be seen. It possesses a duct (Dey), the cystic duct 
(Ductus cysticus), which bifurcates near its origin. 

The two cystic ducts (Fig. 195 Dey) join the larger hepatic 
ducts, as shown in the figure, and so form a simple anas- 


296 


THE ALIMENTARY TRACT, ETC. 


tomosis, from which three branches (3) of varying size unite at the 
anterior extremity of the pancreas to form the common bile-duct 


The pancreas and bile-canals. 


De 
Del 
De? 
Dey 
Dh 
Dhi 


Du 


various other tissues, blood-vessels, hepatic 


Fig. 195. 


The liver has been displaced 
towards the head. 


Common bile-duct. 

Common bile-duct after leaving the pancreas. 

Opening of the common bile-duct into the duodenum. 

Cystic ducts. 

Hepatic ducts. 

Supplementary hepatic ducts from the middle lobe of 
the liver. 

Duodenum. 

Gall-bladder. 

Left lobe of the liver. 

Right lobe of the liver. 

Middle lobe of the liver. 

Fourth lobe of the liver. 


j Gastro-hepatic ligament. 


Stomach. 

Pancreas. 

Pylorus. 

Ducts of the pancreas. 


chyma, and bile-canals. 
a. The peritoneal covering of the liver encloses the organ 
almost completely, the only exceptions being where the various” 


(Ductus choledochus, De). 
The common bile-duct 
runs through the whole 
length of the pancreas, 
receiving near its origin 
additional hepatic ducts 
(Di) from the middle 
lobe of the liver. In 
this course the duct lies 
either on the ventral 
surface of the pancreas 
or under à thin layer of 
the glandular tissue ; it 
receives the ducts of the 
pancreas and leaves that 
organ at its posterior 
border as a round and 
strong canal (Del). The 
duct courses ‘in the 
gastro - duodenal  liga- 
ment, and reaches the 
dorsal surface of the 
duodenum at a very 
acute angle; it then 
pierces the wall ob- 
liquely and terminates 
with a slit-like or elon- 
gated oval opening, 

b. | Minute structure. 

(1) The liver is com- 
posed of various tissues : 
it possesses a peritoneal 
covering’, a fibrous cover- 
ing, which supplies tra- 
beculae to support the 
cells or true liver paren- 


GLANDS CONNECTED WITH THE INTESTINAL CANAL. 297 


attachments of the liver are found (see peritoneum). The perito- 
neal covering of the liver is for the most part composed of flattened, 
ciliated cells (Neumann and Grunau) ; on the middle lobe these are, 
however, more or less replaced by non-ciliated cells. The thickness 
of these cells varies considerably, according to the amount of dis- 
tension to which the liver is subjected. 


8. The fibrous covering of the liver is very thin and very diffi- 
cult to demonstrate ; it consists of connective-tissue fibres with very 
few corpuscles. This covering is prolonged into the liver along the 
portal canals, where traces of connective-tissue can always be 
made out. 

From these processes and from the whole of the inner surface of 
the general connective-tissue capsule are given off fine trabeculae, 
in which it is very difficult to find any nuclei; these trabeculae 
are everywhere extremely delicate and difficult to demonstrate ; 
nowhere do they form distinct boundaries between lobuli: the 
structure closely resembles the sustentacular tissue of a lymphatic 
gland (Eberth). 


y. The blood-vessels to the liver are the portal vessels (p. 
249), the hepatic veins (p. 247), and the hepatic artery! (p. 
233). 

(1) The portal vessels pass into the liver on its ventral surface ; 
they divide into branches which course along the middle parts of 
each lobe and give off smaller branches in all directions towards the 
periphery ; the interlobular branches (Fig: 196 I) forming a very 
complex capillary network. As compared with the hepatic veins 
(Fig. 196 II), the interlobular veins do not give off their capillaries 
so abruptly, but tend to supply these from small lateral branches. 
The portal veins are accompanied in their course by branches of the 
hepatic artery, and often by larger bile-ducts, and thus form 
portal canals. In no part do the portal (interlobular) veins or their 
branches limit the lobules by distinct rings of vessels, as seen in 
many higher animals. The interlobular veins and intralobular veins 
simply interdigitate with each other. 


1 See Plate II, Fig. 196. 


I. Partial injection of the liver from the portal vein (blue) : Rana esculenta.—G. H. 
II. Partial injection of the liver from the hepatic vein (red): Rana esculenta.—G. H. 
III. Complete injection of the liver from the hepatic artery (red) and from the portal vein 
(blue) : Rana esculenta.—G. H. = 


A Portal (interlobular) veins and their branches. 
B Hepatic (intralobular) veins and their branches. 
C Hepatic arteries and their branches. 


298 THE ALIMENTARY CANAL, ETC. 


(2) The hepatic veins (Fig. 196 I and IT) also course chiefly in 
the middle parts of the lobes of the liver; they branch, and ulti- 
mately supply intralobular veins which interdigitate with the inter- 
lobular veins (I and II). The capillaries arise very abruptly from 
an intralobular vein, and form a network of vessels communicating 
very freely with the corresponding capillaries of the interlobular 
veins. 


(3) The hepatic arteries (Fig. 196 III) break up into small 
branches which, as a rule, course along the portal canal until near 
the surface of the liver, when they leave the portal veins and pass 
to the surface to supply the coverings of the liver. In their course 
along the portal canals they supply a few very small twigs to 
the structures forming the canals. At the surface of the liver 
the branches of the hepatic artery form capillaries, which empty 
themselves into the general capillary anastomosis beneath (Fig. 


196 III). 


6. The liver-cells (Figs. 197, 198) are large, and of compressed 
spheroidal or polygonal shape. They possess no cell-wall, have 
usually one but sometimes two large nuclei, each with a distinct 
nucleolus. The cells often contain granules of glycogen or fat- 
globules. The main fibrillae of the intercellular network are 
arranged so as to extend between a bile-capillary and a blood- 
capillary (Fig. 197). 

e. The bile-ducts (Fig. 198) commence as fine tubes between the 
liver-cells, where they are simply small spaces enclosed by the 
hepatic cells; they are usually enclosed by three or four cells, 
possibly sometimes by only two cells (Hering). Such bile-capillaries 
are usually separated from a blood-capillary by the thickness of one: 
liver-cell only (Fig. 198). 


As a number of such bile-capillaries run together to form a larger 
duct, the cells enclosmg them change their character, becoming 
flattened and broader; these cells may, however, be traced contin- 
uously into the true hepatic cells (Hering and Eberth). The bile- 
duct so formed then obtains a slight covermg of fibrous tissue, 
which rapidly increases in quantity, courses along a portal canal, 
and receives other ducts on the way; the epithelium liming it 
gradually becomes more elongated, and ultimately resembles that 
found in the common bile-duct or the gall-bladder. 

In the larger ducts the epithelium is, according to v. Brunn, 


GLANDS CONNECTED WITH THE INTESTINAL CANAL. 299 


ciliated ; they also possess a layer of unstriated muscle-fibre 
(Eberth). 

¢ The pigment of 
the liver varies very 
much in amount and 
character, according 
to the time of the 
year and state of 
health of the animal. 
According to Eberth 
thepigmentary masses 
are of about the same 
sizeas the white blood- 
corpuscles, andare pos- 
sessed of the power of 
amoeboid movement 
(in young animals). 
The cells possess two 
to seven nuclei and vary much in colour and distribution. As 
a rule the larger the amount of pigment in a given liver the 


Liver-cells, after Kupffer. 


Fig. 198. 


The bile-capillaries ; natural injection with sulphindigotate of sodium: y v v represent 
blood-capillaries.—G. H. 


smaller is the number of fat-globules found in the individual 
liver-cells (Eberth). | 


(2) [The gall-bladder and bile-ducts. The gall-bladder has four 
coverings. 


300 THE ALIMENTARY TRACT, ETC. 


a. A serous coat of peritoneal endothelium. 
B. A muscular coat, containing unstriated muscle-fibres and con- 


nective-tissue. 


y. A sub-mucous coat of areolar-tissue. 


Fig. 199. 


Le 


à. An internal lining 
of columnar epithelium. 

e. The walls of the 
gall-bladder are richly 
supplied with blood-ves- 
sels from the cystic ar- 
teries (p. 233); these 
form a close network in 
the submucous coat. 

¢ The muscular and 
submucous coats also 
possess a rich nervous 
plexus, which contains 
ganglia and resembles 
Auerbach’s plexus of the 
intestine (Popoff, Ger- 
lach). | 

B. The Pancreas (Fig. 
FOOT: 

a. General descrip- 
tion. The pancreas is 
a flattened, light yel- 


The pancreas and bile-canals. The liver has been displaced lowish - brown organ, 


towards the head. 


De Common bile-duct. 


Del Common bile-duct after leaving the pancreas, 
De2 Opening of the common bile-duct into the duodenum. 


Dey Cystic ducts. 
Dh  Hepatic ducts. 


Dii Supplementary hepatic ducts from the middle lobe of 


the liver. 
Du  Duodenum. 
G Gall-bladder. 
L Left lobe of the liver. 
L1 Right lobe of the liver. 
L2 Middle lobe of the liver. 
L3 Fourth lobe of the liver. 
Lhp Gastro-hepatic ligament, 
M Stomach. 
ra Pancreas. 
P1 Ducts of the pancreas, 
Py  Pylorus. 


placed in the loop of the 
duodenum between this 
latter and the stomach. 
The whole organ is within 
the gastro-duodenal liga- 
ment, and is attached to 
the liver; hence it is 
little influenced by 
changes in the amount 
of distension of the 
stomach or intestine. 
The organ may be 


completely exposed by either of two methods: in the former, the 
liver, stomach, and duodenum are drawn towards the head and 


GLANDS CONNECTED WITH THE INTESTINAL CANAL. 301 


the dorsal surface of the organ so exposed. In the second method 
the liver is drawn backwards, the various peritoneal folds which 
connect the duodenum with the posterior border of the liver cut 
through, and the three organs then separated; the pancreas can 
then be conveniently examined. 

The size and shape of the pancreas are subject to great variations 
in different specimens. The usual shape of the organ is somewhat 
triangular (Fig. 199), the left border being usually unbroken, while 
the other two shorter borders are broken into lobes. The longest 
lobe stretches as far as the pylorus (Py), to which it is attached by 
connective-tissue : the opposite extremity of the gland is attached to 
the liver. 

The exeretory duct of the pancreas (Ductus Wirsurgianus) opens 
into the common bile-duct at about the middle of the pancreas 
(P'); other smaller ducts may open into the same canal. 

b. Minute structure. [The pancreas consists of a number of 
lobes loosely held together by connective-tissue ; each lobe is com- 
posed of a number of lobules attached to each other much more 
intimately. The lobules are made up of tubes lined by a single 
layer of glandular epithelium. This epithelium is, as a rule, broadly 
columnar, but in the smaller tubes may be cubical or polygonal. 
Each cell has a cell-wall, nucleus, and very granular protoplasm ; 
the latter shows two zones (in the inactive condition), a granular 
zone near the lumen, and an outer, clear, and finely striated zone 
(Nussbaum). .The lumen of each alveolus is very small, and in 
many cases difficult to make out. 

The smallest ducts have no special lining, and are therefore 
bounded by the glandular cells; the larger ducts have a 
flattened, cubical epithelium, which when seen from the sur- 
face has an appearance as if the individual cells were widely 
separated from one another; these ducts have a considerable 
layer of connective-tissue around them. The largest ducts are 
lined with a layer of columnar, ciliated epithelium; the cilia 
are very long, usually of about the same length as the cell, some- 
times appearing to be even longer. This epithelium is contin- 
uous with the ciliated, epithelial layer of the common bile-duct, 
which it resembles. These largest ducts have an extremely thick 
layer of connective-tissue around them. 

The pancreas and its ducts are very richly supplied with vessels 
and nerves ; the nerves forming everywhere a fine plexus, the larger 
strands of which usually, but not always, course with the larger 


302 THE ALIMENTARY TRACT, ETC. 


blood-vessels. The larger ducts have an especially rich supply of 
nerves, of which fibrils may be traced towards the ciliated epithe- 
lium ; an anatomical connection between the two has not, however, 
been made out. | 


Ill. THE SPLEEN. 


a. General description. Although the spleen belongs to the 
lymphatic system, it is considered here in order to complete the 
description of the abdominal viscera. It is a small, rounded-oval 
body, of a reddish-brown colour, suspended in the mesentery near 
the anterior end of the large intestine (Fig. 184 J/z). In medium- 
sized animals the longer diameter is about 6 mm., and is parallel 
with the long axis of the body; the shorter diameter is about 
5 mm., and the thickness varies from about 3 mm. to 4 mm. 
The dorsal surface is flat or shghtly concave (Hilus lienis), and re- 
ceives the relatively large afferent and efferent vessels ; the rest of 
the organ is smooth and rounded, and with its greatest convexity 
directed towards the left side. 


b. [Minute structure. The structure of the spleen resembles 
that of higher animals. It possesses a serous coat of peritoneum, 
under which is a fibrous coat; the latter sends in trabeculae, 
which divide and form a fine meshwork of supporting-tissue ; the 
finest trabeculae are formed by the processes of the connective-cells 
of the sustentacular structure. According to Hoffmann, the thick- 
ness of the fibres averages o‘o01 to o‘o11 mm.; the intervening 
spaces measure 0‘002 to o‘o12 mm. ‘The spaces are filled by the 
spleen pulp, which consists of true spleen-corpuscles, blood-cor- 
puscles, and pigment-corpuscles. 

The spleen-corpuscles have an average diameter of o'co6 mm., 
and are round or of a rounded oval form. Each consists of a nucleus, 
with a very small amount of adherent protoplasm ; the nucleus 
possesses one or two nucleoli. Some of these cells contain a 
brownish or black pigment in granules, but most of them are 
colourless (Hoffmann). 

The pigment-cells equal the white blood-corpuscles in size, and 
exactly resemble the corresponding pigment-cells of the liver. 

The blood-corpuscles are found in various stages of dismtegra- 
tion and regeneration. 


ee 


THE SPLEEN. 303 


The arteries, on entering the spleen, at once break up into 
branches which pass in all directions, giving off twigs on all sides 
and at varying angles; from these capillaries are supplied, which 
traverse the parenchyma in all directions. The capillaries empty 
themselves partly into veins, partly into the splenic spaces. 

The veins commence either as capillaries in connection with the 
arteries or by communicating with the splenic spaces. This com- 
munication is brought about by small twigs of about o‘015 mm. 
diameter, which have incomplete walls, and so open into the splenic 
spaces (Hoffmann). 

Malpighian bodies are represented by collections of splenic 
cells on various arterial twigs ; they are, however, not so sharply 
defined as is the case in some higher animals. | 


IV. THE PERITONEUM. 


a General description. The peritoneum is a thin, pigmented 
membrane lining the abdominal cavity. Tracing it forwards from 
the ventral wall of the abdomen (Peritoneum parieta/e), it can be fol- 
lowed along the deeper surface of the muscles to the pericardium. 
The middle portion leaves the abdominal wall by accompanying the 
anterior abdominal vein ; the lateral portions are continued further 
forwards, and then ascend on the pericardium and the deeper sur- 
faces of the lateral walls in the thoracic region. 

The peritoneum passes thence to the ventral surface of the liver 
(Ligamentum coronarium), covers this surface and passes on to the 
dorsal surface of the organ, which, together with the gall-bladder, it 
completely encloses. The membrane thus reaches the dorsal wall 
(Ligamentum suspensorium hepatis et pericardii); from the lateral 
borders of the liver it passes upwards to the dorsal wall, and thus 
forms a pocket-like pleuro-peritoneal cavity on either side. 

From the dorsal wall and above the attachment of the coronary 
ligament of the bladder the peritoneum reaches the root of the 
lung on each side, and completely invests the organ: while in 
the middle line it covers the outer surface of the oesophagus and 
attaches it to the dorsal wall, thus forming the first part of the 
mesentery 


304 THE ALIMENTARY TRACT, ETC. 


Just behind the root of the lung, the peritoneum, in female speci- 
mens, has an opening on each side (Ostium abdominale tubae Fallo- 
piae), by which the oviduct communicates with the peritoneal cavity. 

Tracing the peritoneum backwards, it passes over the ventral sur- 
face of the kidneys so as to exclude them from the peritoneal sac : 
in the middle line, between the kidneys, the peritoneum descends to 
form the mesentery for the small intestine... At the inner borders 
of the kidneys, the testes or ovaries are pushed into the abdominal 
sac, and so possess well-marked mesenteries ; the mesovarium be- 
comes longer towards the cloaca, but attains its greatest develop- 
ment in the breeding season, when it is arranged in numerous folds. 
Along the outer borders of the kidneys, in females, the peritoneum 
again descends into the abdominal cavities to enclose the oviducts, 
which have broad mesenteries. Towards the rectum these mesen- 
teries are shorter and attached to either side of the bladder by a 
well-marked free border: as the middle line of the bladder is 
attached by the peritoneum to the rectum, two distinct pouches 
(Cava recto-resicalia) are formed, which descend deeply into the 
pelvic cavity. The upper walls of these pouches are pushed in be- 
tween the urostyle and the rectum, and together form a strong 
meso-rectum, which is longer near the Va/vula Bauhinii and con- 
tinuous with the mesentery of the small intestine. The hinder 
portion of this mesentery is very short, and only covers the lateral 
walls of the rectum. 

With the exception of a small portion of its dorsal surface, which 
is attached to the rectum, the whole surface of the bladder is covered 
with peritoneum. 

The mesentery of the alimentary canal commences in connection 
with the oesophagus between the roots of the lungs; it is attached 
to the dorsal surface of the liver, covering the posterior caval vein, 
and is attached to the gall-bladder. From this point it extends, as 
a free, arched fold, to the concave right border of the stomach, 
which is completely surrounded by peritoneum. 

The gastro-duodenal fold (Ligamentum gastro-duodenale) extends 
from the stomach to the pylorus and includes the pancreas. The 
hepato-duodenal fold (Lig. Aepato-duodenale) extends from the portal 
fissure of the liver to the duodenum. 

The mesentery of the small intestine is broad and arranged in 
folds, which follow the curves of the intestine; and is attached in 
the middle line, immediately beneath the vertebrae, where it encloses 
the aorta. 


THE PERITONEUM. 3505 


The various folds and mesenteries carry the blood-vessels and 
nerves to the different organs ; in this course the vessels are sur- 
rounded by large lymphatics, which communicate with each other. 


Preparations from the peritoneum of Rana esculenta.—G. H. 


I. From peritoneum of the ventral wall of abdomen, stained with silver and logwood (Hartnack, 
Oc. I, Syst. 7). 
II. From mesentery of small intestine of Rana esculenta, stained with silver (Hartnack, Oc. I, 
Syst. 7). 
Ill. Preparation to show ciliated cells between non-ciliated cells ; after Neumann. 
IV. Vertical section at border of liver to show ciliated epithelium ; after Neumann. 


A Stoma. 

B  Pigment-cells. 

C Ciliated cells. 

D Non-ciliated cells. 


b. Minute structure (Fig. 201). 


[The peritoneum is a serous membrane, formed for the most part 
of a layer of irregular endothelial cells, arranged on a thin layer of 
subserous, connective-tissue (Fig. 201 I, IT, and III). 

The endothelial cells are attached to each other by cement-sub- 
stance, easily stained by silver nitrate. The cells covering the 
general surface of the peritoneal cavity are larger and broader than 
those covering the mesentery of the small intestine (compare I and 
II, Fig. 201). 

At various points stomata are found, bordered by smaller and 
more deeply staining epithelium (I, 4). The membrane covering 
the general cavity is also much more pigmented than that covering 
the mesentery (compare I and IT). 

Various portions of the peritoneal surface possess ciliated cells, 

x 


306 THE ALIMENTARY TRACT, ETC. 


and these cells are usually thicker than the surrounding non-ciliated 
cells. Such cells are found especially near the openings of the ovi- 
ducts and on the liver. The dimensions of the cells vary ; according 
to Neumann the average dimensions of ciliated cells on the liver are : 
0006 mm. depth (without the cilia); nucleus, 0-012 mm. long and 
07003 mm. broad. The cells are five- or six-sided and bounded by 
straight sides (Neumann). | 


SECTION VI. 


THE LARYNX, LUNGS, VOCAL SACS, THYMUS AND 
THYROID GLANDS, AND THE LYMPHATIC 
GLANDS (TONSILS?) OF THE 
HYOID REGION, 


THE LARYNX, LUNGS, VOCAL SACS, ETC, 


— 
LITERATURE, 


THE LUNGS AND LARYNX. 


Arnold, J., Zur Histologic der Lungen des Frosches. Virchow’s Arch. 1863. Vol. 
XXVIII, p. 433. 

Auerbach, L., Veber den Bau der Platcapillaren in den Lungen des Frosches und 
an éinigen andern Orten. Artlicher Bericht über die vierzigste Versammlung 
deutscher Naturforscher und Aerzte. 1886, p. 241. 

Brittan, Brit. and Foreign Medico-chirargienl Review, 1857. Vol. XX. 

Eporth, C, 3, Ueber den feineren Bau der Lunges. Zeitschr. f. wiss. Zool. 1863. 
Vol, XE, p. 427. 

Eberth, C. 3., Ueber den Baw und die Entwicklung der Blatespillaren. Wirzburger 
naterw. Zeit. 1866-67. Vol. VI, pp. 27-32. 

Egorow, W., Ueber die Nerven der Limgen. Centralbl. f. med. Wiss. 1879, p. 303. 

Elenz, B., Ueber das Langenepithel. Wiürzhurger naturw, Zeit. 1864. Vol. V, 
pp. 66-84. 

Prommann, C., Ueber diespontan, wie durch Durchleiten inducirter Strome, an den 
Plutzellen v. Salamandra maculats and an den Fliramerzellen von der Rachen- 
schleimhant des Frosches eintretenden Verandermngen. Jenaische Sitzangsb. 
1880. 

Gegenbaur, C., Ueber Driisenzellen in der Lungen-Schleimhant bei Amphibien. 
Arch. f. Anat. a. Physiol. 1863, p. 157. 

Griffini, L., Contribuzione alla patol. del tessuto epiteliale cilindrico. Arch. per 
le scienze mediche, 1884. Vol. VIII, pp. 1-43. 

Grittaner, Physiologie der Stimme und Sprache. Hermann’s Handb. d. Physiol. 
Vol. 1, Pt. 11, p. 146. 

Henle, J., Vergleichende Anatomische Beschreibung des Kehlkopfes. Leipzig, 
1839. 

Hoffmann, C. K., in Bronn’s Klassen und Ordnungen des Thierreichs, Leipzig 
und Heidelberg, 1873-78. Vol. VI, pp. 514-531. 

Hoffmann, T., Die Lungengefasse der Rana temporaria. Dissert. Dorpat, 1873. 

Holmgren, PF, Upsala Lakareforenings Forhandlingar, 1867. Vol. II, pp. 


389-309 

Howes, G. B., On s hitherto unrecognised feature in the larynx of the snurous 
amphibia. Proc, Zool. Soe, London, 1887, p. 491. 

Hiiter, C., Ueher den Kreislauf und die Kreislaufsstormngen in der Froschlunge. 
Centralbl. f. med, Wiss. 1373. Nos, 3 and 6, 

Kandarazki, M., Ueber die Nerven der Respirationswege, Arch, f. Anat. a. Phys, 
1881, p. 1. 

Kiittner, Beitrag zu den Kreislaufsverhältnissen in der Froschlunge. Virchow’s 
Arch. 1374. Vol. LXI, p. 21. 

Leydig, Anatomische-histologische Untersuchungen tiber Fische und Reptilien. 
1853. 


310 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


Malpighi, De pulmonibus. Oper. omn. Lugd. Batav. 1687. Vol. II, p. 328. 

Miller, H., Ueber das Vorkommen glatter Muskelfasern in den Lungen der 
Amphibien. Wiirzburger naturw. Zeit. 1861. 

Pertik, O., Untersuchungen über Nervenfasern. Arch. f. mik. Anat. 1881. Vol. 
XIX, p. 183. 

Ranvier, L., Leçons sur l’histologie du système nerveux. Vol. I, pp. 98-Io1. 

Schestopol, A., Ueber die Durchlässigkeit der Froschlunge für geléste und kérnige 
Farbstoffe. Virchow’s Arch. 1879. Vol. LX XY, p. 199. 

Schultze, F.E., Epithel und Drüsenzellen. Arch. f. mik. Anat. 1867. Vol. III, 

Berle 

Schultze, F. E., Die Lungen, in Stricker’s Handbuch der Gewebelehre. 

Stirling, W., On the nerves of the lungs of the newt. Journ. of Anat. and Physiol. 
1882, p. 96. 

Treviranus, C. R., Beobachtungen aus der Zootomie u. Physiologie; nach dessen 
Tode herausgegeben von L. C. Treviranus. Bremen, 1839. 


THE THYMUS GLAND. 


Ecker, Blutgefassdriisen, in Wagner’s Handwürterbuch der Physiologie, 1853. Vol. 
FV, p. 114. 

Fleisch, E., Ueber den Bau einiger sogenannten Driisen ohne Ausführungsgänge. 
Wiener Akad. Sitzungsb. 1870. Vol. LX, Pt. II, p. 55. 

Gegenbaur, Vergleichende Anatomie. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreiches. 1873-1878. 
Vol. VI, p. 503. 

Leydig, Lehrbuch der Histologie. 1857, p. 422. 

Tolldt, Ueber lymphoide Organe der Amphibien. Wiener Acad. Sitzungsb. 1868. 
Male VAE Pt bi py 1 

Watney, H., The minute anatomy of the thymus. Phil. Trans. 1882. Vol. 
CLX XIII, p. 1100. 


THE THYROID GLAND. 


Baber, E. C., Researches on the minute anatomy of the thyroid gland. Phil. Trans. 
1881.- Pt. III, p. 577. 

Ecker, Blutgefässdrüsen, in Wagner’s Handwôürterbuch der Physiologie, 1853. 
Vol. IV. 

Fleisch, E., Ueber den Bau der sogenannten Schilddriise des Frosches. Wiener 
Acad, Sitzungsb. 1868. Vol. LVIII, p. 57. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreiches. 1873-1878. 

Vol. VI, p.- 503. 

Huxley and Martin, Practical Biology. 4th edit., 1877, p. 181. 

Leydig, Lehrbuch der Histologie. 1857, p. 376. 

Miller, J., Ueber die Entwicklung der Schilddriisen des Frosches. Wiener 
Sitzungsb. 1871. Vol. VI, pp. 428-553. 

Müller, W., Ueber die Entwicklung der Schilddrüse. Jenaische Zeitschr. 1871. 
Vol. VI, p. 438. 

Ponicaré, Zur Anatomie der Glandula thyroidea. Journ. de l’anat. et de la 

' physiol. 1877. Vol. XIII, pp. 123-143. 

Rolleston, Forms of Animal Life. 2nd Edit. 1888, p. 77. 

Zeiss, O., Mikroskopische Untersuchungen über den Bau der Schilddrüse. Dissert. 
Strassburg, 1877. 


THE LARYNX, LUNGS, VOCAL SACS, ETC, 


I, THE LARYNX. 


Tue larynx (Fig. 202) is a short wide tube placed between 
the posterior cornua of the hyoid, to which it is attached by 


connective-tissue. 


The long axis cf the tube hes in the median 


line and almost horizontally, but the posterior end is on a slightly 


lower level than 
the anterior, when 
the animal is in 
the natural sitting 
position (Fig. 202). 
The anterior end 
of the larynx opens 
into the mouth by 
a longitudinal slit 
(Fig. 179 L), and 
is placed in a shght 
depression caused 
by the folding of 
the mucous mem- 
brane ; the poste- 
rior end communi- 
cates with the 
cavities of the 
lungs. 

The larynx is 


Fig. 202. 


Dissection to show the position and relations of the larynx. The animal 
(Rana esculenta) is in the natural sitting position; the toes of the 
fore-foot are, however, too much flexed.—G. H, 


B 
C 
E 
Eo 
F 
G 
H 
L 
V 


Brain. 

Gall-bladder. 

Opening of Eustachian tube. 
Oesophagus. 

False vocal cords. 

Epiglottis, 

Heart. 

Liver, 

True vocal cords. 


lined with mucous membrane, which is continuous, in front with 
that of the mouth, behind with that of the lungs. The organ 
has a skeleton of cartilage, and possesses special muscles, 


312 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


by which the supply of air to the lungs, and the voice can be 
regulated. 


a. The cartilages of the larynx. 


The cartilages of the larynx are five in number, of which four are 
paired and one is single. 


(1) The cricoid cartilage (Figs. 203, 204) is an oval ring of 
cartilage with various processes. The ring-like portion of the 
cartilage is placed in a plane which is almost vertical, but which 
is directed slightly upwards anteriorly, and shghtly downwards 
posteriorly (the animal being in the usual sitting position). 


Fig. 203. 


The cartilaginous skeleton of the larynx. 


=. I. Seen from in front ; the spinous process would normally be more curved. 
II. Seen from the left side ; the spinous process should be more curved. 


Ca Right arytenoid cartilage, SR Opening to larynx. 

Cal Left arytenoid cartilage. *** The two outer asterisks are above the two 
C1A-C.1,4 Cricoid cartilage. apices of the left arytenoid cartilage; the 
P Lateral plate of cricoid cartilage. middle one above the pre-arytenoid carti- 
Sp Spine of cricoid cartilage. lage. 


The sides of the ring are slightly curved inwards on the anterior 
surface, and possessed of irregular enlargements (C2261), the space 
enclosed by this portion of the cartilage is occupied by a membrane 
(IT), which forms the floor of the body of the larynx. 

From each side of the body of the cartilage, a process (C./”) is 
given off, which curves backwards and inwards to join its fellow of 
the opposite side, the two forming a blunt spinous process (Sy), which 
projects backwards, and is intimately attached to the oesophagus. 


Between these processes and the lower portion of the body of 


THE LARYNX. ala 


the cricoid cartilage are the apertures of the roots of the lungs 
(Fig. 203), which, by their attachments to these cartilages, are 
kept open. 


(2) The arytenoid cartes (Fig. 203 I, II, Ca, Cal) are a 


pair of cartilages placed 
in front of the cricoid 
cartilage, one on each 
side. Each cartilage is 
semilunar in shape, con- 
cave internally, and 
convex externally. The 
cartilages are placed 
almost vertically, with 
their posterior borders 
or bases parallel to the 
body of the ericoid car- 
tilage. The superior 
borders (Fig. 204) are 
directed upwards and 
forwards, the inferior 
downwards and  for- 
wards. The superior 
and inferior borders are 
separated by a semicir- 
cular notch, bounded by 
two sharp apices. The 
superior and inferior 
angles of the two car- 


tilages are close to- 
gether, and movably 


attached to each other 
by connective-tissue. 


These cartilages vary 
very greatly in the two 
sexes. In the males 
_ they are thick, strong, 
and large ; in the female 
the cartilages are very 
thin, more hollowed and 
much smaller. 


Fig. 204. 


amie larynx and surrounding parts, seen from the ventral 
surface, 


Cal Arytenoid cartilages. 

CU-CH Cricoid cartilage. 

G, Gl Fibrous tissue connect- 
ing the larynx with 
the posterior cornua 
of the hyoid. 


HI Lesser cornua of the 
hyoid. 

HH Greater cornua of the 
hyoid. 


Ig Right lung. 

Ig) Left lung. 

M Fibrous membrane fill- 
ing the ring-like cri- 
coid cartilage. 


Ph+ The M. petrohyoideus 
tertius. 

S Part of tendon of M. 
petrohyoideus ter- 


tius. 

SB, SB1 Mucous membrane 
bulging from the an- 
terior ventricle of the 
larynx. 


Sp  Spinous process of the 
cricoid cartilage. 
ZK Body of the hyoid. 


314 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


(3) [The pre-arytenoid cartilages (Fig. 206 I, P) are two small 
elongated cartilages placed in the semicircular notch between the 
superior and inferior borders of the arytenoid cartilages. They are 
subject to much variation in size, sometimes being merely a very 
slender rod, at others a moderately thick oval mass. In female 
specimens they appear to be, at times, absent, or to unite with the 
arytenoid cartilages, as in these cases a third very small apex 
is found on each arytenoid cartilage ; but it is always much smaller 
than the two neighbouring apices. | 


b. The attachments of the cartilages to each other. 


The cartilages do not articulate directly with each other, but are 
connected by connective-tissue only ; there are, therefore, no syno- 
vial sacs. 

Fig. 205. 


—————— SS 


fips 


The muscles of the larynx. 


A, Aperture between the arytenoid cartilages. HH Greater cornua of the hyoid. 


CI.  Cricoïd cartilage, Jt Fibrous tissue into which the two con- 
C.a.1 Superior angle of the arytenoid cartilage. strictions are inserted. 

C.a.l. M. constrictor aditus laryngis, Ph? Second petrohyoid muscle (M. petrohyoïd. I). 
C.o.4. M. hyo-arytenoideus anterior, Ph3 Third petrohyoid muscle (M. petrohyoid, II). 
C.o.1.1 M. hyo-arytenoideus posterior, Ph4 Fourth petrohyoid muscle (M. petrohyoid. 
D, M. dilatator laryngis. III). 

G Connective-tissue, S,S3,S2 Tendon of the fourth petrohyoid muscle, 
G1 Connective-tissue. Sp  Spinous process of the cricoid cartilage. 

H Smaller posterior cornua of the hyoid. ZK Body of the hyoid. 


c. The muscles of the larynx !. 


The muscles of the larynx appear in the following order, when 
dissected from the mouth :— 


’ The nomenclature adopted is that of Henle and Hoffmann. 


ae pre 


OE a a a ee ne 


THE LARYNX. 519 


(1) The 27. dilatator aditus laryngis (Henle), (Fig. 205 D./.) arises 
on either side from the hinder end of the larger posterior cornu 
of the hyoid: the fibres diverge slightly to be inserted into the 
middle portion of the outer surface of the arytenoid cartilage; a 
smaller bundle of fibres is attached to the deeper-lying constrictor 
muscle and to the cricoid cartilage. 

(2) The J. constrictor aditus laryngis (Henle), (Fig. 205 C.a./.), 
arises on either side from the hinder half of the dorsal surface of 
the posterior cornu of the hyoid. The two muscles enclose the larynx, 
and are inserted into a median tendinous raphe on the under sur- 
face of the larynx (Jt). The raphe is connected with the skeleton 
of the larynx by connective-tissue. 

(3) The 27. hyo-arytenoideus anterior (Fig. 205 C.0./.) arises on each 
side from the inner border of the anterior end of the cornu of the 
hyoid ; the muscle lies close to the anterior border of the arytenoid 
cartilage, and is inserted into a fibrous lamella on the dorsal surface 
of the larynx. The I. petrohyoideus tertius is also partially inserted 
into this lamella. 

(4) The IM. petrohyoideus tertius (Fig. 205 Ph*), (see also p. 66). 
The greater part of this muscle is inserted into the end of the 
posterior cornu of the hyoid (47H); a smaller portion (8, #2?) 
is prolonged to be inserted into the cricoid cartilage and into the 
fibrous lamella into which the MM. hyo-arytenoidei anteriores are 
inserted. 

(5) The 27. hyo-arytenoideus posterior (Fig. 205 C.o./.1) arises on 
each side from the superior angle of the corresponding arytenoid 
cartilage, under cover of the tendon of the MW. petrohyoideus tertius. 
The muscle is inserted into the inferior angle of the arytenoid 
cartilage. 


d. The interior of the larynx (Figs. 202, 206, 207). The cavity 
of the larynx is constricted at two points: anteriorly it is con- 
stricted by the true vocal cords (Figs. 206 7, 207 SB), posteriorly by 
the false vocal cords. The whole cavity is lined with mucous mem- 
brane, which is continuous with that of the mouth anteriorly, with 
that of the lungs posteriorly. 

(1) The true vocal cords are two vertical flat bands of con- 
nective-tissue, attached above to the superior angles of the arytenoid 
cartilages, below to their inferior angles ; their anterior borders are 
thin and free; near their posterior borders they are attached by 
mucous membrane to the internal surfaces of the arytenoid cartilages. 


316 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


The anterior and posterior borders are not parallel but are each 
concave (Fig. 202 F). 
Fig. 206. The anterior border is thin, 
the posterior thick and rounded. 
Seen. from in front (Fig. 206), 
the opening between the cords 
(Rima glottidis) is sightly wider 
at each end than in the middle. 
The ends of the concave poste- 
rior border are prolonged back- 
wards and enclosed in a fold of 
mucous membrane. Part of the 
tissue enclosed is unstriated mus- 
cular fibre, which may be traced 
to the cricoid cartilage. 


(2) [The false vocal cords 
(Figs. 202 and 206 /’) are simply 


Three sections through the larynx of kana folds of mucous membrane A 
esculenta.—G. H. : : 

I. Sagittal section near the median plane which extend vertically on each 

one Janae side of the larynx behind the 

II. Oblique transverse section through larynx. 

III. Almost horizontal section through larynx. true vocal cords; they do not 
He cat extend so far towards the me- 
C'  Cricoïid cartilage. E 
E Epiglottis. dian plane as do the true vocal 
F False vocal cords. : 1 : 

G  Epiglotidean glands. core s. | 

H Hyoid. 5 

M Membranous floor of the larynx, cut (3) [The entricles of the 
obliquely. larynx (Figs. 202 and 206) are 

O Opening into root of lung. : : 

P Pre-arytenoid cartilage. two on each side. The anterior 


Y Vocal cord. . 
pie ventricles are between the true 


vocal cords and the arytenoid cartilages ; they are open anteriorly, 
and closed by mucous membrane posteriorly. 

The posterior ventricles open towards the median plane, each 
presenting an oval opening (Fig. 202), which widens outwards into 
a large cavity (Fig. 206 J/). The cavity is bounded in front by 
the base of the true vocal cord, and the mucous membrane attached 
to it; posteriorly by the false vocal cord, and externally by the 
cricoid cartilage and the connective-tissue capsule of the larynx. | 

(4) [The mucous membrane of the larynx varies in struc- 
ture in various parts of the organ. From the anterior opening 
of the larynx to the posterior borders of the vocal cords it is 
lined with stratified epithelium, which is firmly attached to the 
underlying structures by a small amount of sub-epithelial 


ee dr à 


EE a a à 


THE LARYNX. ake 


tissue. This is especially well marked on the vocal cords 
themselves. 

Behind the vocal cords the mucous membrane 
is much more loosely attached to the surrounding 
structures by an extremely vascular areolar tissue. 
The epithelium is arranged in a single layer 
of columnar cells, among which are numerous 
goblet-cells. In the more external parts of the 
posterior ventricles, the mucous membrane is 
thrown into deep folds and so forms polygonal 
acim. In the median line of the floor of the 
larynx and behind the false vocal cords is a 
vertical fold of mucous membrane, which in- 
creases in height and breadth as it proceeds 5, pimaglottidis, seen 
backwards towards the roots of the lungs. The from the front. 
mucous membrane behind the true vocal cords ©, (me soit. 
is extremely vascular, in the most posterior 
portion of the larynx the blood-vessels form a capillary network 
exactly like that of the lungs. | 


e. [The epiglottis (Fig. 206 /) is a small bilobed fold of mucous 
membrane placed on the floor of the mouth in the median plane and 
immediately in front of the aperture to the larynx. Between it 
and the mucous membrane covering the arytenoid cartilages are a 
number of large mucous glands (G&). The epiglottis does not contain 
cartilage ; it is, however, constant in its appearance and sharply 
marked off from the surrounding mucous membrane. | 


Il. THE LUNGS. 


a. General description. The lungs are two large thin-walled 
sacs (Figs. 185 and 204 Zg and Lg"). The roots of the lungs are 
contracted at their origin from the larynx and then expand to form 
two ellipsoid sacs, which terminate posteriorly in bluntly-pomted 
ends. With the exception of their roots they le entirely free in 
the pleuro-peritoneal cavity, and are covered by the pleuro-peri- 
toneal membrane. In the recent state they have a bright red 
colour due to the large supply of blood-vessels. 


b. Minute structure. — 


(1) The muscular tissue of the lungs is for the most part 
arranged in large bands, which form a coarse network on the deeper 


318 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


surface of the organ; when seen in section! (PI. II, Fig. 208 4, 4) 
these bands are found to be composed of well-developed imvolun- 
tary muscular fibres. Between the larger bands are smaller bands 
having a similar arrangement. From these networks of muscular 
bands finer processes of muscular tissue pass peripherally towards 
the surface of the organ, and are attached to the thin and incom- 
plete muscular layer found in the wall of the lung (C). 


(2) The connective-tissue of the lungs is present in only small 
quantity, but is still sufficient to fill in the spaces between the 
various muscular bands and the surface of the lung, and to invest 
the whole of that surface. There is thus formed a series of pits, 
the mouths of which open into the general cavity of the lung, 
while their bases are at the surface. Through this connective- 
tissue course the blood-vessels, nerves, and lymphatics. It contains 
numerous yellow elastic fibres. 


(3) The blood-vessels of the lungs. The pulmonary artery 
courses along the outer surface of the lung to the apex, giving 
off, at right angles, lateral branches in the whole of its course ; 
these show a tendency to be alternately larger and smaller. The 
lateral branches divide and form a rich capillary network (T. 
Hoffmann). 

The capillary network has very small meshes; the diameter of a 
given mesh being frequently less than that of the capillary bounding 
it. The meshes are rounded or polygonal in shape. 

The pulmonary vein arises by lateral branches from this capillary 
network ; the branches join, at right angles, the main vein, which 
courses from the apex of the lung along its inner surface to the 
root of the organ. 


(4) The epithelium of the lungs. Externally the lungs are 
covered with a layer of endothelium derived from the peritoneum. 
Internally the surface is covered with an epithelium which varies 
considerably in different positions. 

On the free borders of the muscular trabeculae forming the 


‘See Plate II, Fig. 208. 


Two sections from the lung of Rana temporaria ; stained with borax carmine.—G. H. 
I. The lung dilated (Hartnack, Oc. I, Syst. 3). 
II. The lung contracted (Hartnack, Oc. I, Syst. 7). 


A Band of muscle cut transversely. B Band of muscle cut longitudinally. 
C Muscular layer of surface. 


THE LUNGS. 319 


borders of the alveoli is a short columnar ciliated epithelium (Fig. 
208); such epithelium is also found in the root of the lung; it 
contains goblet-cells. 

The alveoli, for the most part, are lined with a single layer 
of tesselated epithelium; the cells are polygonal in outline, 
with finely granular contents and a distinct nucleus: the average 
diameter of the cells is from 00074 to o‘o108 mm., that of the 
nucleus 0°0054 mm., that of the nucleolus o‘o009 mm.; four to 
eight of such cells occupy the space enclosed by one mesh of the 
capillary network (Eberth). 

The epithelium rests on a structureless basement membrane, which 
is continuous over the whole inner surface of the lung, whereas the 
epithelium does not pass over the capillaries, and is therefore only 
found in isolated patches in the areas enclosed by the capillaries 
(Eberth). 

In various isolated spots, small groups of short columnar or 
goblet-cells are found in the tesselated epithelium (Eberth, Hoff- 
mann). 

(5) [The lymphatics of the lungs have been described by T. Hoff- 
mann; they form a network of vessels surrounding the larger 
blood-vessels: from this branches are given off, which form a 
network of fine canals through the whole of the lung; part of this 
secondary network accompanies the blood-capillaries, but other 
portions run a separate course. They communicate with the 
pleuro-peritoneal cavity. 


(6) The pigment-cells are very numerous, branched, and large ; 
they accompany the lymphatics, and not the blood-vessels (T. Hoff- 


mann). 


(7) The nerves of the lungs (p. 172) course along the larger blood- 
vessels, under the serous coat; the fibres are chiefly medullated 
fibres (Egorow, Kandarazki). Non-medullated branches, which form 
a plexus in each alveolus, are given off. The branches have small 
triangular enlargements (ganglia), where they unite. The nerves 
are accompanied by nerve-cells, which occur either singly or in 
groups. 

Egorow describes the nerves as being distributed in three net- 
works : one for the mucous membrane and muscular trabeculae ; -a 
second for the superficial muscular layer; and a third for the serous 
membrane. | 


320 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


Ill. THE VOCAL SACS. 


a. General description. ‘The vocal sacs are a pair of sacs 
which open in the floor of the 
mouth (Fig.179 8); they are found 
only in the males. When the 
animal croaks these sacs are di- 
lated and act as resonators; when 
so dilated the sacs force up the 
skin under the angle of the mouth 
and tympanic membrane. In well- 
developed specimens they are about 
as large as an average sized cherry. 
The skin covering the sacs is ex- 
Dissection to show the vocal sac of the tremely elastic, but is not directly 
24 DE ae attached to the sacs. 


HH  Larger posterior cornua of the hyoid. 


HH1 Smaller posterior cornua of the hyoid. b. Minute structure. The sac 
My Mylo-hyoid muscle, : t f i ta tl 
My1 Mylo-hyoid muscle continued on to consists of connective-tissue, with 

oa) Lei large proportion llow elasti 
Thy Thyroid glands. Bae APPODOT ETS of ye oN S . < 
VH Anterior cornua of the hyoid. fibre. Internally 1b 1s lined with 


Z Body of the hyoid. 5 : 
‘ a flattened epithelium, and exter- 


nally is covered with a layer of striated muscular fibre, derived 
from the mylo-hyoid muscle (Fig. 209 My, My). 


Vic THE, THYMUS. GLANT 


a. General description. The thymus gland (Fig. 210 7/)is placed 
on each side behind the angle of the jaw; it is best exposed by re- 
moving the skin behind the tympanic membrane and the angle of 
the jaw, and then reflecting the J/. depressor mandibulae (D.m.). The 
gland is then found as an elongated, oval body, not quite 3 mm. 
long, lying in the space between the A7. depressor mandibulae and 
the J. sternocleulomas toideus (St); it extends slightly beyond the 
posterior border of the former muscle. The space also includes 
connective-tissue, fat, and numerous vessels. 

In Rana temporaria this gland is spherical, much smaller, and 
placed further behind on the 47. sternocletdomastoulens, between the 
M. latissimus dorsi and the M. de/toideus (Wiedersheim). 


THE THYMUS GLAND. pels 


b. Minute structure (Fig. 211). 
[The gland is surrounded by a connective capsule, which is 
indented on the inner surface to form 


a hilus through which blood-vessels 
course into the organ. 

The capsule sends in numerous fine 
trabeculae, which form a connective- 
tissue skeleton such as is found in all 
lymphatic glands. The corpuscles of 
the trabeculae possess elongated nuclei 


Fig. 210 


from O‘OI9 to 0028 mm. in length, Dissection to show relations of the 
and o‘o1o to o‘o15 mm. in breadth thymus gland. 
De. M. deltoideus. 
(Tolldt) à The trabeculae support a D.m.M. depressor mandibulae. 
network of blood-vessels. L.d. M. latissimus dorsi. 
2 St M. sternocleidomastoideus. 
The meshes of this sustentacular Tf Tympanic membrane. 


tissue are filled with cells; these are : 


Th Thymus gland. 


(a) Lymphoid cells, rounded or oval, possessing a round nucleus 
and nucleolus, and an extremely small amount of adhering: proto- 
plasm; the size of the nucleus is from o‘orr to o‘o15 mm. 


(Tolldt). 


IIT. 


IV. 


From various sections from the thymus gland of Rana esculenta.—G. H. 


Complete gland (Hartnack, Oc. I, Syst. 3). 

a Pigment-cells. % 
Portion of a section (Hartnack, Oc. I, Syst. 7) showing small corpuscles of Hassall. 
Portion of a section showing lobules with degenerating cells. 

a Capsule of lobe. 

b Lobules. 

ec Large corpuscle of Hassall, surrounded by normal tissue. 


Nerve-cell ? (corpuscle of Hassall), after Fleisch]. 


(8) Corpuscles of Hassall (Fig. 211 II, III, and IV) are, as a 


rule, large bodies, but are subject to much variation in size. Their 


Y 


322 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


general appearance is seen in Fig. 211 III; they show a concentric 
striation and usually enclose one or more smaller cells. They 
therefore closely resemble similar corpuscles found in higher 
animals. 

(y) In many frogs the cellular structure of at least a part of 
the gland seems to have undergone a degenerative stage (III). In 
such cases the connective-tissue is increased in quantity, and marks 
off portions of the section into small lobules (III) which are 
filled with cells containing mucus or sometimes fat (III). Under 
what conditions this degeneration, if such it be, takes place has 
not yet been determined ?. 

(6) Large branched pigment-cells are found in the course of the 
larger blood-vessels. 

(e) Watney describes also four varieties of ‘ granular cells :? 
1. polygonal or rounded; 2. vacuolated; 3. spheroidal masses ; 
4. club-shaped masses attached to the blood-vessels. I have, how- 
ever, not been able to distinguish them. | 

[Tolldt (Z.c. 1868) described the lymphoid tissue and the blood-vessels of this gland 
but did not find the corpuscles of Hassall. 

Fleisch] (/.c. 1870) disputed Tolldt’s description ; he evidently found the corpuscles 
of Hassall (see Fig. 211 IV), but he held them to be nerve-cells, and described them 
as such. He was also of opinion that the blood-vessels open into the intercellular 
spaces (as in the spleen). This has not been found to be the case by any other 
observer. Watney (/.c, 1882) first described the concentric corpuscles of Hassall 
as such. 


Most writers describe the parenchyma as arranged in lobules. This I have only 
seen in a part of the gland and under what I believe to be pathological conditions. | 


V.. “THE, ‘THY ROTD* GLAND: 


a. General description. A thyroid gland (Fig. 209 Thy) is 
found on either side as a small, triangular, or oval, reddish-coloured 
body on the dorsal surface of the J. sternohyoideus, just before 
it passes between the AJM. genio-hyoidei. It lies in the angle 
formed between the larger and smaller posterior cornua of the 
hyoid (7H, HiT"). It is easily found by the presence of a large 
number of vessels in its neighbourhood, and especially by the 
large jugular vein, to the ventral surface of which it is intimately 
attached. 


! Only winter-frogs were at my disposal (translator). 


THE THYROID GLAND. 323 


Not uncommonly several smaller supplemental glands are found 
in the rich anastomosis surrounding the organ. 

The dorsal surface of the 
gland is lobulated, the ventral 
surface flatter and convex. 
The glands of opposite sides 
are seldom symmetrical. 


b. Minute structure (Fig. 
212 I and II). [The gland 
possesses a  connective-tissue 
capsule, which sends in trabe- 
culae to support the vesicles of 
which the gland is composed. 

The vesicles (I and IT), 
which vary greatly in size, are 
closed> cavities, usually of a 
rounded or oval form, but some- 
times branched (Baber). Each 
vesicle is lined with a single 
layer of cubical or slightly 
columnar epithelium (II, a), 
which rests on a _ delicate 
basement-membrane of con- 
nective-tissue, placed between 
the epithelium and the sur- 
rounding lymphatics (Baber). 

Zeiss describes a delicate reti- 

Minute structure of the thyroid gland of Rana 


culum between the epithelial esculenta.—G. H. 
cells. i ae oe the gland (Hartnack, Oc. I, 
à , Syst. 3). 

The vesicles always contain 11, small portion of above (Hartnack, Oc, I 

mucus (4), and are surrounded Bye 7): 
2 a Epithelium lining the vesicles. 

by a fine anastomosis of blood- b Mucus, 
vessels (c).] c¢ Blood-vessels, injected with blue mass. 


H 


D 


EN 


Ang A 


VI. THE LYMPHATIC GLANDS OF THE HYOID 
REGION (TONSILS ?). 


a. [General description. These are two oval, reddish-coloured, 
soft lymphatic glands, placed one on each side of the larynx. 
Frequently they are divided into two or three lobes by more or less 

w2 


324 THE LARYNX, LUNGS, VOCAL SACS, ETC. 


deep fissures. They are constant in their occurrence, and are 
frequently supplemented by one or more smaller glands; each 
gland has the larynx on its inner 
side, the Vera jugularis externally, 
the I. omohyoideus in front, and 
above the mucous membrane of 
the pharynx (Tolldt). 

b. Minute structure, The 
glands consist of dense lymphoid 
tissue (Fig. 213), but possess in 
addition one or more large bodies 
(a) which resemble lymphoid fol- 
licles in structure. Each is com- 
posed of a dense mass of small 
Part of section through the lymphatic gland cells ; and the whole follicle = os 

(tonsil?) of Rena esculenta (Hartnack, de. 1, Im similar follicles of higher ani- 
SSR ANT 2 iain mals, sharply differentiated from 
a Extremely large lymphoid follicle, . 
the rest of the organ. 

The glands possess an extremely rich vascular supply, and are 
frequently pierced by one or more large arterial trunks. 

The mucous membrane covering the glands is thinner than that 
immediately around, but is not perforated. ] 


Fig. 213. 


[As far as I am aware, Tolldt is the only observer who describes these glands: he 
makes no mention of the lymphoid follicles.) 


a ni se ee ee 


SECTION VII. 


THE URINO-GENITAL SYSTEM, THE ADRENALS, 
AND THE FAT-BODIES. 


THE URINO-GENITAL SYSTEM, ETC, 


LITERATURE. 


THE URINO-GENITAL ORGANS. 


Adami, J. G., On the nature of glomerular activity in the kidney. Journ. of Physiol. 
1886. Vol. VI, p. 382. 

Ankermann, De moturo et evolutione filorum spermaticorum. Regimonti, 1854. 

Ankermann, Einiges über die Bewegung und Entwicklung der Samenfiden des 
Frosches. Zeitsch. f. wiss. Zool. 1857. Vol. VIII, p. 129. 

Beale, L. S., On very fine nerve-fibres ramifying in certain fibrous tissues, and of 
trunks and plexuses consisting entirely of fine nerve-fibres in the bladder of the 
frog. Beale’s Archives of Med. 1864. Vol. IV, pp. 19-251. 

Bergmann, C. G., De glandulis suprarenalis. Dissert. Gdttingae, 1839. 

Bidder, Vergleichende Anat. und histol. Untersuchungen über die männlichen 
Geschlechts- und Harnwerkzeuge der nackten Amphibien. Dorpat, 1846. 

Biondi, D., Die Entwicklung der Spermatozoiden. Arch. f. mik. Anat. 1885. Vol. 
XX V, p. 594- 

Bloomfield, J. E., The development of the Spermatozoa. Quart. Journ. Micros. 
Sci. 1881. New Series. Vol. XXI, p. 415. 

Bôttcher, A., Ueber den Bau und die Quellungsfihigkeit der Froscheileiter. Vir- 
chow’s Arch. 1866. Vol. XX XVII, p. 174. 

Bouillot, J., Sur l’épithélium sécréteur du rein des Batrachiens. Compt. rend. 1882. 
Vol. XCV, No. 14, pp. 603-604. 

Bourne, A. Gibbs, On certain abnormalities in the common frog, Rana temporaria. 
Quart. Journ. Micros. Sci. 1884. New Series. Vol. XXIV, pp. 83-86. 

Bowman, W., Sur la structure et fonctions des glandules des reins ou corpuscules de 
Malpighi. Annal. des Sci. Zool. 1843. Series II. Vol. XIX, pp. 108-145. 

Bowman, W., On the structure of the Malpighian bodies of the kidney, ete. 
Phil. Trans. 1842. Pt. I, pp. 57-80. 

Bowman, W., Ueber die Structur und den Nutzen der Malpighischen Korper in 
den Nieren. Froriep’s Notizen, 1842. Vol. XXII, No. 21, coll. 321-324. 
Bowman, W., Ueber die Structur und Functionen der Malpighischen Korper in den 

Nieren. Froriep’s Notizen, 1843. Vol. XXV, No. 12, col. 177. 

Brandt, A., Fragmentarische Bemerkungen über das Ovarium des Frosches. 
Zeitsch. f. wiss. Zool. 1877. Vol. XXVIII, p. 575. 

Budge, Harnreservoir der Wirbelthiere. Mittheil. aus d. naturw. V. v. Neu-Pom- 
mern und Rügen. 1875, p. 103. 

Carus, C. G., and Otto, A. W., Erläuterungstafeln zur vergleichenden Anatomie. 
Leipzig, 1840. 

Crivelli e Maggi, Alcuni cenni sovra lo studio dei corpi piangiati delle Rane. Rendi- 
conti del Reale Istituto Lombardo de scienze e lettere. 1869. Second Series. 
Vol. II, p. 716. 

Della Chiaje, Esistenza della glandule renala ne Batruci et ne Pisci. Napoli, 1837. 

Drasch, O., Ueber das Vorkommen zweierlei verschiedener Gefissknauel in der Niere. 
Wiener Sitzungsb. 1878. Vol. LX XVI, Part ITI, p. 79. 

Duncan, J., Ueber die Malpighischen Kniiuel in der Froschniere. Sitzungsb. d. 
Acad. zu Wien, 1867. Vol. LVI, Pt. II, p. 6. 


THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 327 


Duval, M., and Wiet, Ueber die Wanderung der Eier in die Bauchhéhle beim 
Frosche. Gaz. de Paris, 1880. No. 17, p. 210. 

Duval, M., Recherches sur la Spermatogénèse chez la grenouille, Revue Sci. nat. 
Montpellier, 1880. Vol. II, pp. 121-143. 

Ecker, Der feinere Bau der Nebennieren, etc. 1846. 

Eimer, T., Untersuchungen über den Bau und die Bewegung der Samenfiden. 
Verhandl, d. phys.-med. Gesell. in Wiirzburg, 1874. Vol. VI, New Series, p. 93. 

Engelmann, Zur Physiologie des Ureter. Pfliiger’s Arch. f. d. ges. Physiol. 1869. 
iViolee tl pe 243. 

Fürbringer, M., Zur vergleichenden Anat. und Entwicklungsgesch. d. Excretions- 
organe der Vertebraten. Morph. Jahrb. Vol. IV. 

Fürbringer, M., Zur Entwicklung der Amphibienniere. Heidelberg, 1877. 

Gerlach, J., Beitriige zur Structurlehre der Niere. Arch. f. Anat. u. Physiol. 1845, 
p- 378. 

Gibbes, H., On the structure of the Spermatozoon. Quart. Journ. Micros. Sci. 1880. 
Vol. XX, p. 318. 

Goette, A., Entwicklungsgeschichte der Unke. Leipzig, 1875. 

Goette, A., Kurze Mittheilungen aus der Entwicklungsgeschichte der Unke. Arch. f. 
mik. Anat. 1873. Vol. IX, p. 396. 

Grunau, H., Ueber das Flimmerepithel auf dem Bauchfell des weiblichen Frosches 
und über den Hileiterbau desselben. Dissert. Kéonigsberg, 1875. 

Grinhagen, A., Untersuchungen über Samenentwickelung. Centralbl. f. d. med. 
Wiss. 1885. Vol. XXIII, p. 481. 

Grünhagen, A., Ueber die Spermatogenese bei Rana fusca (temporaria). Centralbl. 
f. d. med. Wiss. 1885. Vol. XXIII, p. 737. 

Gscheidlen, R., Zur Lehre v. d. Nervenendigung in den glatten Muskelfasern. 
Arch. f. mik. Anat. 1877. Vol. XIV, p. 321. 

Heidenhain, R., Mikroskopische Beitrige zur Anatomie und Physiologie der Nieren. 
Arch. f. mik. Anat. 1874. Vol. X, p. I. 

Helmann, Ueber die Entwicklung der Spermatozoen der Wirbelthiere. Dissert. 
Dorpat, 1879. 

Henle, J., Zur Anatomie der Niere. Nachrichten v. d. k. Gesell. d. Wissensch. z. 
Gottingen, 1862. Vol. X, pp. 4-12; and in Abhandlungen, 1861-62, Vol. X, 
p22: 

Hoffmann, C. K., in Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig and 

Heidelberg, 1873-1879. Vol. VI. 

Hüfner, Zur vergleichenden Anatomie und Physiologie der Harncaniilchen. Diss. 
Leipzig, 1866. 

Hyrtl, Ueber die Injection der Wirbelthierniere, etc. Wiener Acad. Sitzungsb. 
1863. Vol. XLVII, Pt. I, p. 172. 

Jensen, O.S., Recherches sur la spermatogénese. Archives de Biologie, 1883. Vol. IV. 

Jensen, ©. S., Ueber die Struktur der Samenkorper bei Säugethieren, Vügeln, und 
Amphibien. Anat. Anzeiger. 1886. 

Knappe, E., Das Biddersche Organ. Morph. Jahrb. 1886. Vol. XI, pp. 489-548. 

Kolessnikow, N., Ueber die Eierentwicklung bei Batrachiern und Knochenfischen. 
Arch. f. mik. Anat. 1878. Vol. XV, p. 382. 

v. Kélliker, A., Gewebelehre. Fifth Edition. 

Langer, C., Ueber das Lymphgefisssystem des Frosches. Wiener Acad. Sitzungsb. 
18607 Vol. LV; Pt. Lp: 625. 

Lavdowsky, M., Ueber die Endigung der Nerven in der Harnblase des Frosches. 
Centralbl. f. d. med. Wiss. 1871, p. 33. 

Lavdowsky, M., Die feinere Structur und die Nervenendigungen der Froschharn- 
blase. Arch. f. Anat. u. Physiol. 1872, p. 55. 

Lereboullet, A., Recherches sur l’anatomie des organes génitaux des animaux verté- 
brés. Nov. acta Acad. Leop. Car. 1851. Vol. XXIII, pp. 1-226. 


328 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


Leydig, F., Anatom.-histol. Untersuchungen über Fische und Reptilien. 

Leydig, F., Lehrbuch der Histologie des Menschen und der Thiere. Frankfurt, 
1857, p. 508. 

Leydig, F., Untersuchungen zur Anatomie und Histologie der Thiere. Bonn, 1883. 

List, J. H., Ueber Becherzellen im Blasenepithel des Frosches. Wiener Sitzungsb. 
1884, Vol. LXXXIX, Pt. III, pp. 186-210 ; also in Arch. f. mik. Anat. 1887, 
Vol. XXIX, p. 147. 

List, J. H., Ueber Becherzellen im Blasenepithel des Frosches. Zool. Anzeiger, 
1884. No. 169, p. 328. 

List, J. H., Ueber einzellige Driisen im Blasenepithele der Amphibien. Biol. Cen- 
tralbl. 1885. Vol. V, p. 499. 

Loos, P. A., Die Eiweissdriisen d. Amphibien und Vogel. Zeitsch. f. wiss. Zool. 
1881. Vol. XXXYV, pp. 478-504. 

Maier, R., Die Ganglien in den harnabführenden Wegen des Menschen und einiger 
Thiere, Virchow’s Arch. 1881. Vol. LXXX V, pp. 49-71. 

Marcussen, J., Ueber die Cloake und Harnblase der Früsche. Bull. der phys.-math. 
Acad. de St. Pétersbourg, 1853. Vol. XI. 

Marshall, A. M., On certain abnormal conditions of the reproductive organs in the 
frog. Journ. of Anat. and Physiol. 1884. Vol. XVIII, p. 121. 

Marshall, A. M., The frog. Manchester and London. 2nd Edit. 1885. 

Mecznikow, E., Zur vergleichenden Histologie der Niere. Güttinger Nachrichten, 
1866, p. 61. 

Meyer, F., Beitrag zur Anatomie des Urogenitalsystems der Selachier und Am- 
phibien. Sitzungsb. d. nat. Gesellsch. Leipzig. 1874, p. 38; published 1875. 
Moleschott, Ein histochemischer und ein histologischer Beitrag zur Kenntniss der 

Nieren. 

Miescher, Die Spermatozoen einiger Wirbelthiere. Verhandl. d. naturf. Gesell. in 
Basel. 1878. Vol. VI. 

Neumann, E., Untersuchungen über die Entwickelung der Spermatozoiden. Cen- 
tralbl. f. d. med. Wiss, 1868. No. 24. 

Neumann, E., Untersuchungen über die Entwickelung der Spermatozoiden, Arch. 
f. mik. Anat. 1875. Vol. XI, p. 292. 

Neumann and Grunau, Driisen der Froscheileiter. Arch. f. mik. Anat. 1875. Vol. 
xe pase 

Nussbaum, N., Ueber die Niere der Wirbelthiere. Sitzungsber. Bonn, 1870. 

Nussbaum, N., Ueber die Endigung der Wimpertrichter in der Anurenniere. 
Sitzungsb. d. niederrheinischen Gesell. in Bonn, 1877. Vol. XXXIV, p. 122. 

Nussbaum, N., Ueber den Bau und die Thätigkeit der Drüsen. Arch. f. mik. Anat. 
1886. Vol. XXVII, p. 442. 

Nussbaum, N., Ueber die Secretion der Niere und tiber die Verbindung der 
Samen und harnbereitenden Drüsenschläuche in den Nieren der Batrachier. 
Sitzungsb. d. niederrheinischen naturf. Gesell. in Bonn, 1877. Vol. XXXIV, 
Pp: 277- 

Nussbaum, N., Fortgesetzte Untersuchungen iiber die Secretion d. Niere. Pfliiger’s 
Arch. f. d. ges. Physiol. 1878. Vol. XVII, p. 580. 

Nussbaum, N., Ueber die Endigung der Wimpertrichter der Niere der Anuren. 
Zool. Anzeiger, 1880. No. 67, pp. 514-517. 

Nussbaum, N., Zur Differenzirung des Geschlechts im Thierreich. Arch. f. mik. 
Anat. 1880. Vol. XVIII, p. 73. 

Peltier, Sur les zoospermes de Ja grenouille. L’Institut. 1838. Vol. VI. 

Perrault, C., De generatione ranarum fusca et bona dissertatio, in Actis Erudi- 
torum, 1687. 

Prévost, Note sur les animalcules spermatiques de la grenouille et de la Salamandre. 
Mémoires de la société phys. et d’hist. nat. de Genève. Geneva and Paris, 
1841-1842. Vol. IX, p. 289. 


LITERATURE. 329 


Rathke, H., Beiträge zur Geschichte der Thierwelt, III Abth.; and Neueste Schr. 
d. naturf. Gesell. in Danzig. 1825. Vol. I. 

Reger, R., Ueber die Malpighischen Knäuel der Nieren und ihre sogenannten 
Capseln. Arch. f. Anat. u. Physiol. 1864, p. 537. 

Reichert, On kidney. Jahresbericht über Anatomie in Arch. f. Anat. u. Physiol. 
1843, p. 220, etc. 

Remak, Untersuchungen tiber die Entwicklung d. Wirbelthiere, p. 128. 

Retzius, G., Zur Kenntniss der Spermatozoen. Biol. Untersuchungen. 1881. 

Rideward, W. G., On an abnormal genital system in a male of the common frog. 
Anat. Anz. 1888. Vol. III, p. 333. 

Robinson, C., Ueber die Lymphgefiisse der abdominal Eingeweide des Frosches. 
Froriep’s Notizen, 1846. No. 807, col. 225. 

Rôsel, A. J., Historia naturalis ranarum nostralium. 1758, p. 28. 

Roth, Untersuchungen über die Drüsensubstanz der Niere. Bern, 1864; and 
Schweiz. Gesellsch. f. Heilkunde, 1864. Vol. III, pp. 1-34. 

Schiefferdecker, Ueber einzellige Drüsen in der Blase der Amphibien. Bericht. 
d. naturf. Ges. in Rostock, 1883. 

Schultze, F. E., Das Drüsenepithel der schlauchférmigen Drüsen des Dünn- und 
Dickdarms und die Becherzellen (Cloaca of frog), Centralbl. f. d. med. Wiss. 
1866, p. 161. 

Schultze, M., Observationes nonnullae de ovorum ranarum segmentatione. Bonn, 
1863. 

Schultze, O., Untersuchungen über die Reifung und Befruchtung des Amphibieneies. 
Zeitsch. f. wiss. Zool. 1887. Vol. XLV, pp. 177-226. 

Schweigger-Seidel, F., Ueber die Samenkérperchen und ihre Entwicklung. Arch. 
f. mik. Anat. 1865. Vol. I, p. 309. 

Solger, B., Beiträge zur Kenntniss der Nieren und besonders der Nierenpigmente 
der niederen Wirbelthiere. Abhandl. d. naturf. Ges. zu Halle, 1882. Vol. XV. 

Spengel, J. W., Die Segmentalorgane der Amphibien. Verhandl. d. phys.-med. 
Gesells. Würzburg. Vol. X, pp. 89-92. 

Spengel, J. W., Das Urogenitalsystem der Amphibien. Arbeiten aus d. Zool. Inst. 
in Wiirzburg, 1876. Vol. III, pp. 1-114. 

Spengel, J. W., Wimpertrichter in der Amphibienniere. Centralbl. f. d. med. 
Wiss. 1875, p. 369. 

Swammerdam, J., Bibblia naturae. Leydae, 1738. Vol. II, p. 796. 

Thompson, A., Article ‘Ovum’ in Todd’s Cyclopedia of Anatomy and Physiology, 
London, 1879. Vol. V, p. 91. 

Tolotschinoff, Ueber das Verhalten der Nerven zu den glatten Muskelfasern der 
Froschharnblase. Arch. f. mik. Anat. 1869. Vol. V, p. 509. 

Tornier, O., Ueber Bürstenbesätze am Drüsenepithel. Arch. f. mik. Anat. 1866. 
Vol. XX VII, p. 181. 

v. la Valette St. George, Spermatologische Beitrage. Arch. f. mik. Anat. 1886, 
Vol. XX VII, p. 385; and in Stricker’s Gewebelehre, Article ‘ Hoden.’ 

Valentin, On kidney. Repertitorium, 1845. Vol. VIII, p. 92. 

Waldeyer, W., Hierstock und Eï. Ein Beitrag zur Anatomie und Entwick- 
lungsgesch. der Sexualorgane. Leipzig, 1870. 

Weldon, W. F. R., On the suprarenal bodies of vertebrata. Quart. Journ. Micros. 
Sci. 1885. Vol. XXV, p. 137. 

v. Wittich, W., Beitrage zur morphologischen und histologischen Entwicklung der 
Harn- und Geschlechtswerkzeuge der nackten Amphibien. Zeitsch. f. wiss. Zool. 
1052 AVL, IY pers 2. 

Wolff, W., Die Innervation der glatten Muskulatur. Arch. f. mik. Anat. 1882. 
Vol. XX, p. 361. 


330 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


THE ADRENALS. 


Bergmann, De glandulis suprarenalibus. Dissert. Gottingen, 1830. 

Ecker, A., Der feinere Bau der Nebennieren beim Menschen und den vier Wirbel- 
thierklassen. Braunschweig, 1846. 

Frey, H., On the suprarenal capsules, in Todd’s Cyclopedia. London, 1849, p. 827. 

Giles, A. E., On the development of the fat-bodies in the frog. Quart. Journ. 
Micros. Sci. 

Hoffmann, C. K., Bronn's Klassen und Ordnungen des Thierreichs. Heidelberg 
und Leipzig, 1873-1878. Vol. VI, p. 506. 

v. Kélliker, A., Handbuch der mikroskopischen Anatomie. Leipzig, 1854. Vol. II, 
p- 386. 

Leydig, Lehrbuch der Histologie. Frankfurt a. M. 1857. 

Moers, Ueber den feineren Bau der Nebennieren. Virchow’s Arch. 1864. Vol. 
XXIX, p. 336. 

Nagel, Ueber die Structur der Nebennieren, Arch. f. Anat. u. Physiol. 1830, p. 377- 


THE FAT-BODIES. 


Carus, Lehrbuch der Zootomie. Leipzig, 1818 (describes the fat-bodies as supra- 
renals). : 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Heidelberg 
und Leipzig, 1873-1878. Vol. VI. 

Marshall, A. Milnes, The frog. Manchester and London, 1884. 

v. Wittich, W., Beitriige zur morphologischen und histologischen Entwicklung der 
Harn- und Geschlechtswerkzeuge der nackten Amphibien. Zeitsch. f. wiss. Zool. 
PSKS 0 VOL LV ip. 252: 


THE URINO-GENITAL SYSTEM, THE 
ADRENALS, ETC. 


———— 


THE URINO-GENITAL SYSTEM. 


By cutting through the meso-rectum the posterior caval vein is 
seen, as a large vessel, arising’ by numerous transverse branches from 


the ventral surfaces of the kidneys 
and testes (Fig. 214 Cv), lying in 
the median line between the kid- 
neys ; by drawing it to one side the 
dorsal aorta is brought into view 
(Fig. 214 do). The testes are placed 
on the ventral surface of the kidneys, 
and together with the fat-bodies 
conceal the anterior portions of these 
organs. The posterior portions of 
the kidneys are covered by perito- 
neum only, and may by seen with- 
out further dissection. The kidneys 
lie dorsal to the peritoneum, and have 
this membrane on their ventral 
surfaces only ; their dorsal surfaces 
are in contact with the lumbo- 
sacral plexus. 

The ureters extend from the 
anterior border of the eighth verte- 
bra to the middle of the urostyle, 
where they terminate by two orifices 
in the dorsal wall of the cloaca 
(Fig. 184). 

The testes are entirely surrounded 
by peritoneum, except a small part 


{Hilus) of the inner surface, where | 


the vessels and ducts enter. 


The male urino-genital organs, 
Ao Aorta, 


C4 Cloaca. 

Cv Inferior vena cava, 

FK Fat-body. 

H Testis. — 

N Kidney. 

S, Sl Openings of ureters, 

Ur  Ureter. 

Vr Renal veins, 

t+ Appearance of ureters on the ven- 


tral surfaces of kidneys. 


The urino-genital organs are arranged in the same manner in 
the two sexes; the ovaries corresponding in position with the 


3932 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


testes (Fig. 214), that is, they are bilaterally symmetrical, and 
placed on the ventral surfaces of the kidneys. 

The oviducts (Fig. 224 Ov) lie externally to the kidneys and 
ovaries, and course through the whole length of the trunk from the 
roots of the lungs to the cloaca. The size of the ovaries and oviducts 
varies very greatly according to the season of the year; at times, 
the kidneys may be entirely hidden by them. 


I. THE URINARY ORGANS. 
A. The kidneys. 


a. General description. Hach kidney (Fig. 215) is a reddish- 
brown, elongated organ, almost semilunar in shape; the inner 
border being straight and the outer convex. 
The organ is flattened from above down- 
wards, and decreases in thickness towards 
either end. In animals of average size 
the kidney is about 16 mm. long, and 
from 6 to 7 mm. broad. The kidneys 
lie parallel to the vertebrae. 

The outer border is smooth and even, except at its posterior third; 
where a slight depression for the ureter exists; the mner border 
has usually two or three well-marked notches, the hindermost of 
which is the deepest (Fig. 215). Each notch is continued outwards 
as a groove, traversing the whole breadth of the ventral surface 
and containing a branch of the renal portal vem. The ventral 
surface is, as a whole, slightly concave, grooved, and lobulated ; 
the dorsal surface is smooth and shghtly convex. 


Fig. 215. 


The right kidney, seen from the 
ventral surface. 


b. [Minute structure. The kidney is enclosed in a thin capsule 
of fibrous tissue (Fig. 220 Ly), which sends in fine trabeculae to 
support the glandular structures and the blood-vessels. ] 

(1) The blood-vessels of the kidney are the renal veins, the renal 
arteries, and the renal portal vein. 

a. The renal portal vein (p. 247) courses along the outer border 
of the posterior part of the kidney, and then along the outer margin 
of the dorsal surface; in this course it gives off large branches, 
which course inwards and forwards and supply numerous lateral 
twigs. These anastomose to form a network of vessels on the 
dorsal surface of the organ, from which very numerous large 
branches course downwards and somewhat inwards to joi corre- 
sponding branches of the renal veins (Fig. 216 I). 


THE URINARY ORGANS, 39 


The blood-vessels and lymphatics of the kidney.—G. H. 


I. Transverse vertical section through kidney. Venous system blue; arteries red (Hartnack, 
Oc. I, Syst. 3). 
II, Part of a horizontal section through kidney. Venous system blue; arteries red (Hartnack, 
Oc. I, Syst. 3). 
III, Part of a transverse vertical section through kidney ; lymphatics blue (Hartnack, Oc. I, Syst. 7). 
A Ventral surface. 
B Dorsal surface. 
C Two arterial twigs uniting before entering the Malpighian body. 


B. The renal veins (p. 247) form a coarse plexus on the ventral 
surface of the kidney, from this numerous large branches (Fig. 216 I) 
course upwards and outwards. 

The venous system between the renal portal veins on the dorsal 
surface, and the renal veins on the ventral surface, are so large that 
they can scarcely be named capillaries (Hyrtl). 

y. The renal arteries (p. 233) are distributed to the ventral 
surface of the kidney ; their mode of distribution varies in different 
parts of the organ. <A simple arrangement is that shown in 
Fig. 216 I, where a branch traverses the breadth of the kidney and 
gives off branches to the Malpighian corpuscles; in one case (C) 


334 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


I have seen two twigs passing to the same corpuscle; as a rule, 
however, each Malpighian corpuscle receives only one twig. A more 
general arrangement is that the artery courses nearer the ventral 
surface and in a more winding course, several twigs are then given 
off close together, from the convex surface of one of the curves, and 
these course to their respective corpuscles. 

In the Malpighian corpuscle the arterial twig forms a series of 
loops and then passes out to open abruptly into one of the branches 
of the neighbouring venous anastomosis (Hyrtl). 

(2) [The Malpighian corpuscles and their capsules (Figs. 216 I, 
218 III). The corpuscles lie nearer the ventral than the dorsal 
surface. They are rounded oval bodies, formed of loops of an 
arterial twig, held together by a small amount of connective-tissue. 
Each corpuscle is enclosed in a capsule, which it incompletely fills 
(Fig. 217)": 

The capsules are formed of connective-tissue and lined with a 
flattened epithelium (Fig. 218 III) : according to Duncan the fibrous 
coat is arranged in two layers (III 4). Towards the opening of the 
uriniferous tube the epithelium increases in thickness. 

According to Hyrtl, the corpuscles are arranged in two layers, a 
more superficial one and a deeper one ; and are of two sizes, the 
larger being as a rule the more superficial (ventral).] 

(3) [The uriniferous tubes (Figs. 217 and 218). Each tube 
originates at a narrow opening on the dorsal surface of a Mal- 
pighian capsule. The tube gradually widens and is lined with 
a short rounded or cubical epithelium (Roth), (Fig. 218 III); each 
epithelial cell bearing a small number of extremely small cilia (Bow- 
man, Külliker, Duncan, and others). The cilia of the cells nearest 
the capsule are directed towards it ( Heidenhain), those of the cells 
further away have an opposite direction (Spengel). This portion of 
the tube is known as the neck ; it courses dorsalwards. 

The second portion of the tube (Zubulus contortus), (Fig. 218 
III, IX, and XII) has a very tortuous course in the dorsal part 
of the kidney, and then winds towards the ventral surface. This 
portion is lined with columnar epithelium, which has granular 
contents, and possesses large distinct nuclei. The cells of this part 


1 See Plate IT. 


Portions of two transverse vertical sections through the kidney,—G. H. 


I. Kidney of Rana esculenta, partial injection of the uriniferous tubes with silver nitrate 
(Hartnack, Oc. I, Syst. 7). 
IJ. Kidney of Rana temporaria, stained with borax-carmine (Hartnack, Oc. 1, Syst. 7). 


THE URINARY ORGANS. 33D 


Fig. 218. 


Various preparations to show the structure of the uriniferous tubes, etc. 


Three portions of the uriniferous tubes from Rana esculenta, from a natural injection with 
sulphindigotate of sodium (Hartnack, Oc. I, Syst. 3).—G. H. 
From the third part of a uriniferous tube; short ciliated epithelium, borax-carmine (Hart- 
, nack, Oc. I, Syst. 7).—G. H. 
A Malpighian corpuscle and capsule ; shows the capsule of two layers at a. After Duncan. 
Part of uriniferous tube after natural injection with sulphindigotate of sodium (Hartnack, 
Oc. I, Syst. 3).—G. H. 
Transverse section of one of the larger branches of the ureter, from Rana esculenta (Hartnack, 
Oc. I, Syst. 7).—G. H. 
Epithelial lining of the ureter itself while stillin the kidney (Hartnack, Oc. I, Syst. 7).—G. H. 
Portion of a uriniferous collecting-tube from section in Fig. 217 I, stained with silver (Hart- 
nack, Oc. I, Syst. 7).—G. H. 
Renal epithelium ; @ to 6, tubulus contortus ; b to c, third portion of uriniferous tube ; c to d, 
fourth portion of tube. After Heidenhain (enlarged 210 times), 
Ciliated cells of the neck, after Duncan. 
Tsolated rod-cells of Triton taeniatus, after Heidenhain. 
Isolated rod-cells, after Heidenhain (enlarged 300 times). 
Isolated cells of the neck, after Heidenhain (enlarged 210 times), 
Portion of the fourth part of a uriniferous tube, after Heidenhain (enlarged 300 times). 
Ciliated epithelium of tubulus contortus, after Tornier (magnified 550 times}. 
From kidney of Rana temporaria, after Spengel. 
a Uriniferous tube opening into seminiferous duct. 
b Dilated seminiferous duct cut longitudinally, 
c Vas efferens cut transversely. 


336 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC, 


of the kidney are usually more or less coloured with a golden- 
yellow pigment. According to Tornier it bears short cilia (Fig. 
218 XIV). 

The third portion corresponds with the narrow limb of Henle’s 
loop ; it is lined with ciliated epithelium (Fig. 218 VIII, é to c), 
similar to that in the neck of the tube. 

The fourth portion (Fig. 218 VIII, ¢ to d, and XIII) repre- 
sents the wider limb of Henle’s loop. It has a winding course 
in the ventral part of the kidney, and then ascends dorsally to 
open into a collecting-tube. The fourth part of the tube is lined 
with a short, columnar epithelium (Fig. 218 VIII, ¢ to @), which 
has a clear, cuticular, free border, large nucleus, and a peculiar 
arrangement of the protoplasm, which shows a rod-like structure 
(Fig. 218 XI). 

The collecting-tubes course transversely near the dorsal surface 
of the kidney (Fig. 217), and the uriniferous tubes meet them at 
right-angles. They are lined with a short polygonal epithelium 


(Fig. 218 VII). 


The peritoneal funnels of the kidney (nephrostomes). Spengel, Meyer, and 
Hoffmann describe these funnels as existing in the frog; according to them they 
open on the ventral surface by narrow apertures, and each is connected, by a vertical 
tubule, with the fourth part of the uriniferous tube (Spengel), but according to 
Nussbaum, with the neck of the tube. According to Spengel and Meyer the number 
of these funnels is in Rana from 250 to 360. 

According to Wiedersheim the funnels hang free from the ventral surface like so 
many parasites attached by fine filaments, and do not open on the surface. 

Heidenhain (Arch. f. mik. Anat., Vol. X) was unable to find these organs. 

Being unable to find any trace of these organs in the kidneys of either R. tempo- 
raria or R. esculenta, in microscopie sections or in teased preparations, J inserted 
canulae into the ureters of both male and female specimens of both species, and 
injected the uriniferous tubes with a solution of Berlin blue. Although the tubules 
were, in some cases, completely injected, in no case could I find any trace of a 
peritoneal funnel, nor was there any escape of the solution from the kidney as would 
be the case if the funnels were open and communicated with any part of the uri- 
niferous tubes. Even when the pressure was increased to the extent of a column 
of 25 cm. high of the injection-mass, no escape took place from the surface of the 
kidney, though in numerous cases the uriniferous tubes were ruptured by the abnor- 
mally high pressure. 

Properly dissected frogs were placed in 0-6 °/, sodium chloride solution, in which 
finely divided gamboge was suspended. No trace of ciliary action was, in any case, 
found on either surface of the kidneys. 

One may therefore conclude that if the peritoneal funnels exist in the adult frog 
(1) they are very difficult to find; (2) they do not form a free communicating path 
between any part of the uriniferous tubes and the abdominal cavity; (3) their 
superficial terminations have no free cilia. As before stated I have found no 
trace of any such organs. 


THE URINARY ORGANS. 337 


The lobules of the kidney. When treated with proper reagents 
the kidney shows a marked tendency to separate into lobules (Fig. 
219 I). 

The lymphatics of the kidney (Fig. 216 III") form an irregular 
network of fine canals with elongated meshes. They run chiefly 
in the direction of the blood-vessels. The large vessels, which 
supply the kidney, are surrounded by large lymphatics.] 

The nerves of the kidney (Fig. 21g I1)'. Little is known of 
these. Nerve-fibres have been traced alongside the larger blood- 
vessel through the greater part of the kidney. 


B. The ureters. 

a. General description. In the males the ureters are, at the 
same time, the seminiferous ducts. Each ureter commences on the 
dorsal surface of the kidney by bifurcating branches, which are 
continuous with the collecting-tubes of the kidney. In the anterior 
two-thirds of the kidney the ureter is wholly on the dorsal surface ; 
at the junction of the middle and posterior thirds it winds round to 
the outer border of the kidney (Fig. 214 Ur), and there lies in a 
groove accompanied by the renal portal vein (Fig. 220 Ur and /a), 
the two organs being intimately attached to the kidney substance 
and enclosed by the fibrous capsule (By). 

This portion of the ureter possesses a spindle-shaped enlargement, 
which represents the Receptaculum seminis. In Rana temporaria the 
Receptaculum seminis forms a large saccular dilatation. 

In its further course the ureter runs backwards and slightly 
inwards, converging with its fellow of the opposite side; the ureters 
lie free in the abdominal cavity, and terminate by two openings 
placed side by side in a groove on the dorsal wall of the cloaca 
(Fig. 214 8, S1). 

In females the ureters are intimately attached to the dilated 
oviduct, immediately after leaving the kidney; they pursue a 
similar course to those of the males, but are attached to the oviduct 
in the whole of their course to the cloaca. 


b. Minute structure. The ureter is a tube composed of connective- 


1 See Plate IT. 
Two portions from a gold preparation of the kidney of Rana esculenta.—G. H. 


I. Showing the tendency to split into lobules, 
If. Nerve-fibres accompanying the blood-vessels. 
a Blood-vessels. 
b Nerves. 


Z 


338 THE URINO-GENITAL SYSTEM, THE ADRENALS, “ETC. 


tissue and involuntary muscular fibre, and lined with a mucous 
membrane. The mucous membrane is thrown into longitudinal 
folds, and consists, in the larger tubes, of two or three layers of 
epithelium (Fig. 218 V), that on the 
free surface is columnar; the deeper 
cells being rounded or polygonal. 
The larger branches of the ureter are 
lined with columnar epithelium (Fig. 
218 VI), with small intervening cells. 
In some parts of the branches the 
columnar epithelium bears short cilia. 

No glands have been found in the 


v 
ureter or Aeceplaculum seminis; mM 
d) (ES Rana temporaria, however, the Recep- 
à LA af =a gee = as 
RTE TC] laculum seminis possesses large, branch- 
EN . re . 
“Or, ing mucous glands (Wiedersheim). 
C. The bladder. 
a. General description. ‘The uri- 
Transverse section of the kidney, nary bladder (Fig. 185 ITB) is closely 
enlarged. =) . 
ie Gniicativa Hanoi eue. attached to the ventral wall of the 
yg Donel sure cloaca and is easily distended from 
NC Renal parenchyma. : Ê 
Ur Ureter. that organ. In relation to the animal 
V Ventral surface. ato ë : 
a aon pial wei: it is of very large size; in consequence 


of its being contracted in the middle 
it has two lobes, which may be of unequal size. The organ is 
somewhat heart-shaped (Figs. 184 and 185), with the narrow neck 
attached to the cloaca, into which it opens by a smaller aperture on 
the ventral surface. The aperture is surrounded by a small fold of 
mucous membrane. 


b. |Minute structure. The urinary bladder is bounded by a 
thin, transparent wall, lined internally with mucous membrane, and 
covered externally by peritoneum. 


(1) The muscular coat is formed of a network of fine bands of 
unstriated muscular fibre (Fig. 221); it is supported and completed 
by a connective-tissue layer, rich in connective-tissue corpuscles and 
yellow elastic fibres. — 


(2) The peritoneal coat is a single layer of endothelial cells 
derived from the peritoneum and resting on a very thin layer of 
subperitoneal tissue. 


THE URINARY ORGANS. 339 


(3) The mucous coat is formed of epithelium resting on a layer of 
loose, areolar tissue. The epithelium (Fig. 221 I, IT, and IV) is 


Fig. 221. 


f |. 


Various preparations from the bladder. 


1, Silver preparation of the mucous membrane; seen from the surface. After List (enlarged 
400 times). 
a Cells of the surface. 
d Goblet-cells. 
e Young cells. 


II. Vertical section of the mucous membrane ; after List (enlarged 600 times). 
a Cells of upper layer. 
b  Cells of middle layer. 
4 e Cells of lower layer. 


III, Large multicellular ganglion ; after Wolff, 


IV. Vertical section from a silver preparation of the mucous membrane ; after List (enlarged 600 
times). 
| a Upper layer. 
b Middle layer. 
ce Lower layer. 
d Goblet-cells, 


V. Small ganglion of bladder; after Wolff, 
a Non-medullated nerve-fibre leading to ganglion. 
b Process of a ganglion cell. 


arranged in three layers: the cells of the uppermost (II and 
IV, a) always present a flat or convex border to the cavity of the 
organ ; seen from their free surfaces (I) they have polygonal out- 
lines intermixed with round apertures belonging to goblet-cells, the 
remaining surfaces of these cells are serrated. The cells of the 
middle layer (II and IV, 4) are polygonal in outline, they are not 
so tall as the cells of the layer above ; all their borders are serrated. 
The cells of the deepest layer (II and IV, «) are more or less pointed 
above where they project between the cells of the second layer ; their 
lowest surfaces are flattened towards the subepithelial tissue, and 
all their surfaces are serrated. 


340 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


The cells of all three layers possess a cell-wall, and finely gran- 
ular contents, and each cell has a large oval nucleus (List). 

The goblet-cells (Fig. 221 I and IV, d) vary very much in shape ; 
they are always more or less rounded in outline: they vary greatly 
in size (from 190 y to 54 p in length); some possess ‘ feet’ or basal 
prolongations, in others these are absent. They usually open freely 
by rounded apertures on the surface of the mucous membrane, 
but are sometimes closed. The nucleus is placed towards the base 
of the cell and surrounded by a smaller or larger amount of proto- 
plasm. These cells usually extend into the middle layer of the 
epithelium, and they probably constitute unicellular mucous glands 
(List). 

(4) The blood-vessels of the urinary bladder (p. 235) are very 
numerous and run in very tortuous courses; they are accompanied 
by large lymphatics and by nerves. 


(5) The nerves of the urinary bladder (p. 191) are of both medul- 
lated and non-medullated fibres, which course together towards 
their points of distribution ; the non-medullated fibres are, however, 
much more frequent than the medullated fibres (Wolff). 

The non-medullated nerve-fibres stand in close relation with the 
nerve-ganglia of the bladder. These ganglia may be unicellular, or 
composed of groups of nerve-cells ; the cells vary considerably in 
shape, round, oval, triangular, and other forms being equally 
frequent in their occurrence; to some extent the form appears to 
depend upon the number and position of the processes of the cells. 
The diameter of the cells varies from o'05 mm. to o'r mm.; the 
nucleus has a diameter of 0-025 mm., that of the nucleolus measures 
0005 mm. (Wolff). 

The cells may be unipolar or multipolar; the former are however 
rare. The processes of these cells supply the muscle-fibres (Fig. 
221 V, a), and other non-medullated processes connect the cells 
with the nerves (V, 4 (Wolff) ). 

The number of muscular fibres is far in excess of the number of 
the fibres of distribution of the ganglia ; Wolff hence concludes 
that the nervous impulse may pass from one muscle-fibre to 
another. | 


THE REPRODUCTIVE ORGANS. 341 


IL THE REPRODUCTIVE ORGANS. 


A. The male reproductive organs are the testes and their 
ducts. 

a. General description. The relations of the testes have 
already been given (p. 234); the organs vary much in shape 
and size in different individuals and with the different seasons ; 
when greatest they are spherical, or of a rounded oval form, occasion- 
ally cone-shaped or pear-shaped. The surface of the testes is not 


Fig. 222. 


The male reproductive organs (enlarged). 
CC Vasa efferentia within the kidney. 


H Testis. 

LL  Collecting-tube at inner border of kidney. 
N Kidney. 

Ne Vasa efferentia within the mesorchium, 
Ur  Ureter. 


tt Vasa efferentia ending blindly. 


smooth, but presents a series of convexities, each corresponding 
to a lobule of the gland. At the /z/ws on the inner border the vessels 
pass to and from the organ, and the Vasa efferentia leave the testis. 

The number of Vasa efferentia (Fig. 222 I and IT) is subject to 
considerable variation, not only in different animals, but on the 
two sides of the same animal. In some cases these ducts form a 
network (I), in other cases this is absent (II); usually the ducts 


THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


342 


i 


Most of 


en 


\ 


AG Fe, DE DATE) 

a : ‘hited PL 
5 Bees 2 
= 


bifurcate at acute angles, just before entering the kidney. 
the tubes so formed open into the collecting-tube ; a few, however, 


ing 


ferentia 


asa e 
on reach 


= 


After Neumann, 


II. Section from testis of Rana esculenta (Hartnack, Oc. I, Syst. 7).—G. H. 


2 


After Neumann. 


Granular protoplasmic feet of spermatoblasts. 


After Neumann. 
Rounded epithelium, 


Rounded epithelium of seminiferous tubes. 


Spermatoblasts. 


Various preparations from the testis. 
Seminiferous tubes. 
IV. Surface view of seminiferous tube of Rana temporaria. 


Thin connective-tissue capsule. 


Trabeculae. 


and d 


a 
b 
c 

III. From testis of Rana temporaria. 
us 
y 
a 


I. Various stages of the spermatozoa ; from testis of Rana temporaria. 
b 


the kidney they curve dorsalwards between that organ and the 


end blindly in the mesorchium (I, +). The course of the / 
from the testis is first inwards, within the mesorchium 


THE REPRODUCTIVE ORGANS. 343 


corresponding testis: the ducts then travel in the ventral surface 
of the kidney towards its inner border, where they open into a 
longitudinal canal (Bidder), (Fig. 222 I, Z). Just before their 
terminations each duct has an enlargement (I, C), the exact import 
of which is unknown (see also Fig. 218 XV). 

The collecting-tubes open into the ureter at the hinder extremity 
of the kidney. 


b. [Minute structure. The testis possesses a thin connective- 
tissue capsule underneath its peritoneal covering (Fig. 223 II, a); 
this sends in trabeculae (4) towards the centre of the organ, and so 
encloses the separate lobules. Each seminiferous tube arises from an 
elongated irregular sinus placed towards the middle of the organ ; 
the tubes (c) are slightly convoluted in their course towards the 
periphery, near which they branch (Spengel). The tubes are from 
0°16 mm. to o‘12 mm. in diameter (Külliker), and are lined with 
two kinds of cells (Fig. 222 III); the cells (#) nearer the periphery 
are rounded and have large rounded nuclei, the diameters of which 
vary from o‘o13 to 0:02 mm.; these again possess large and 
distinct nucleoli. The other cells (y) are of elongated, spindle- 
shaped form; and have oval nuclei, with an average length of 
07016 mm. and an average breadth of 0-005 mm. (Neumann). 

The rounded cells lie in groups which vary in thickness and 
arrangement, and are often compressed so as to have polygonal 
outlines. The spindle cells are arranged so as to radiate from the 
lumen of the tube to the periphery, at an angle which varies from 
45 to go degrees ; these are the spermatoblasts. 

The various changes which the spermatoblasts undergo in the 
formation of spermatozoa will easily be understood by reference to 
Fig. 223 I, a to 4, where 7 and & represent the fully developed 
spermatozoa. These have three parts, head, middle part, and tail, 
the respective lengths of which in the two species are, according to 
Neumann, the following :— 


Head. . Middle part. Tail. 
Rana esculenta O‘O140 MM. 010025 mm. O‘040 mm. 
Rana temporaria 0000; "0033017 PCO045 4; 


At the hilus of the testis the rounded cells of the seminiferous 
tubes are gradually modified to form short cylindrical cells (o‘or 
mm. long and 0‘006 mm. broad), the spindle cells being absent 
(Neumann). The Vasa efferentia are also lined with a similar 
columnar epithelium (Spengel). | 


344 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


B. The female reproductive organs. 
The position of these organs has already been given (p. 335). 


I. The ovaries. 


Fig. 224. 
2 & / 
1 
4) 
WT GMMPNWPS 


The female reproductive organs; the ovary of the right 


side has been removed. 


N Kidney. 


0.T. Opening of the oviduct into pleuro-peritoneal cavity. 


Ov Oviduct. 

Ova Ovary. 

P Opening of oviduct into the cloaca. 
S, S1 Openings of the ureters. 


Ut Dilated hinder portion of the oviduct. 


+ Groove in which ureters lie. 
* 


b. Minute structure. 


Fold in groove separating the openings of the ureters, 


a. General description. 
Each sac-like ovary (Fig. 
224) is subdivided by thin- 
walled septa into numerous 
complete chambers, to the 
inner walls of which the 
ova are attached. The 
walls of adjacent sacs are 
intimately attached to each 
other, and the subdivision 
corresponds with the ex- 
ternal lobulated appearance 
of the organ. According 
to Spengel the number of 
lobules is about fifteen 
(Rathke nine to thirteen, 
Brandt nine). Whether 
this segmentation of the 
ovary corresponds with the 
segmentation of the body 
has not been determined 
(Spengel). No part corre- 
sponding with  Bidder’s 
organ has been found in 
Rana esculenta. 

During the breeding 
season the ovaries undergo 
an extraordinary increase in 
size so as to occupy the 
greater part of the body- 
cavity and to displace the 
other viscera. The ovaries 
are entirely surrounded by 
peritoneum. 


[The layer of peritoneum covering the 


ovary possesses cilia (Thiry), the ciliated cells being arranged in 
isolated patches (Schweigger-Seidel, Waldeyer) on the ventral surface 
of the organ, and on the mesovarium; these patches are some- 


THE REPRODUCTIVE ORGANS. 345 


times united by very fine connecting lines of ciliated epithelum ; 
the ciliated epithelium is always sharply marked off from that 
surrounding it (Kolessnikow). Under the peritoneum is a thin 
layer of connective-tissue, which is prolonged inwards to form 
the septa above-described. To these septa are attached the ova. 

Between the connective-tissue layer and the peritoneum are 
isolated patches of germinal epithelium (Fig. 225 IV); these are 
easily distinguished, by the rounded outlines of their cells, from the 
surrounding “epithelial cells (Waldeyer, Kolessnikow). These 
patches of germinal epithelium measure from 0°0g3~-0°186 mm. 
in diameter; the germinal cells average 0‘0139-0°0232 mm. in 
diameter (Kolessnikow). The patches are most numerous on the 
outer surface of the ovary, and particularly so near the mesovarium. . 

The follicles contained in the ovary have a connective-tissue coat 
developed in a manner similar to that of higher animals; the 
primordial ova which they contain have large nuclei (0°0325 mm.). 
The epithelium of the follicles has an average diameter of 0°0232— 
0°0325 mm. (Kolessnikow). 

Schultze’s description of the ovaries (/.c.) varies de 
from that of Waldeyer and Kolessnikow. Briefly he describes the 
ovaries as a series of sacs separated by and lined externally and 
internally by endothelium ; between these two layers are found 
the germinal epithelium and follicles: the structures being held 
together by an extremely minute quantity of connective-tissue. | 


IT. The oviducts. 

a. General description. In young animals the oviducts are 
quite straight, thin-walled, and of small calibre. During the 
breeding season, however, they undergo an immense increase in 
size, and become much convoluted ; in this state they are forced in 
between the other abdominal viscera, and usually cover the whole of 
the kidneys, and sometimes even part of the ovaries (Fig. 224 Ov). 

The openings of the oviducts into the pleuro-peritoneal cavity 
(p. 304) are semilunar slits, directed inwards and lined with ciliated 
epithelium (p. 306). 

Immediately behind this opening (Ostiwm abdominale) the ovi- 
duct is contracted, and is there narrower than in the rest of its 
length; beyond this it expands, and then retains an even size 
nearly to its hinder extremity, where it suddenly expands (Fig. 
224 Ut). This dilatation gradually diminishes in size as it pro- 
ceeds backwards towards the cloaca, into which each tube opens on 
a small papilla. The dilated portions of the tubes lie close together, 


346 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


but do not communicate with each other; the opening of the right 
tube is always slightly behind that of the left side (Fig. 224 P). 
From the papillae, into which the oviducts open, a fold of mucous 
membrane extends backwards on the dorsal surface of the cloaca to 
meet its fellow of the opposite side at an acute angle (Fig. 224%). 
The orifices of the ureters are placed within these folds. 


b. Minute structure. 

(1) The tubular portion of the oviduct has three walls: 
a peritoneal covering with sub-peritoneal tissue (a); a glandular 
layer (4); and an epithelial lining (c). Of these the glandular 
layer forms by far the thickest layer, especially durmg the 
breeding season, when it is much increased in thickness. It 
consists of long cylindrical glands, often bifurcated at their blind, 
peritoneal ends. The epithelial cells, with which they are lined, 


r & 


cL 
DLL: LL) Lu, 
# ARR EE 
yy < 3 


FEES ) 


(NT. a A 
2) GSES aio) 


Preparations from ovary and oviduct. 


I. Ciliated epithelium and goblet-cells of the oviduct ; after Neumann. 
IT. Isolated goblet-cells and secretory cells from oviduct ; after Neumann, 
a, b, ce Goblet-cells. 
d, e, f Secretory cells after treatment with Müller’s fluid. 
æ Stoma of secretory cells, 
III. Surface view of the ovary ; after Kolessnikow. 
a Peritoneal endothelium, 
6 Germinal epithelium. 


have the power of absorbing more than a hundred times their own 
weight of water (Boettcher). This layer is absent at the anterior 
opening of the oviduct. 


THE REPRODUCTIVE ORGANS. 347 


The cells have an average diameter of 0-012 mm., the lumen of 
the individual glands o°1 mm. (in spirit-hardened specimens, Neu- 
mann). The cells contain small rounded bodies of very varying 
size, which may exist singly, grouped, or even arranged in rows ; 
they swell on the addition of water. Each cell possesses, in addition, 
an oval, granular, distinct nucleus. When treated with Muller’s fluid 
many of the secretory cells have the appearances shown in Fig. 225 
II, d, e, f; they each possess an opening (+), (Neumann). 

According to Neumann the great power of absorbing water, 
which the oviducts possess, is due to the presence of these bodies, 
which he names ‘colloid granules... The mucous secretion of 
these glands passes into the oviduct and surrounds the eggs on 
their passage towards the cloaca: it is due to this secretion that the 
ego-spawn is so extremely slippery and difficult to handle. 

The inner surface of the oviducts is lined with a ciliated, columnar 
epithelium (Fig. 225 I), containing numerous goblet-cells (I and IT). 


(2) The dilated portion of the oviduct has much thinner walls 
than the anterior, narrower portion ; the glands cease abruptly at the 
junction of the two parts. The outer coat also contains unstriated 
muscular fibre; the inner surface is lined with ciliated epithelium 
similar to that of the anterior portion. 

The lymphatics of the oviducts form a net with polygonal 
meshes on their outer surfaces ; from this branches pass inwards in 
the spaces between adjacent glands to the inner surface, where a 
network with elongated meshes is formed (Langer). 


C. [The Cloaca. 


a. General description. The cloaca is a short tube lying 
beneath the urostyle; anteriorly it receives the openings of the 
ureters, rectum, and bladder; and in the female the openings of 
the oviducts, in addition : posteriorly it terminates at the anus. 


b. Minute structure. The cloaca is lined internally with a 
mucous membrane resembling that of the rectum, e.g. a simple 
layer of columnar epithelium, which rests on a submucous, areolar 
layer. | 

The outer walls consist of a thick superficial, longitudinal mus- 
cular layer, and a deeper, ill-developed, transverse muscular layer. 


c. Special muscles of the cloaca. 
(1) The MW. sphincter ani surrounds the end of the cloaca from the 
anus to the tip of the urostyle. It consists of striated muscle. 


348 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 


(2) The J/. compressor cloacae arises from the tip of the urostyle, 
and is inserted into the hinder end of the rectum; it is also 
attached to the symphysis of the iliac bones ; from this point a few 
fibres pass to the anus (Hoffmann). | 


lil): THE ADRENALS. 


a. General description. The adrenals are small yellow bodies 

Fig. 226. attached to the renal veins on 
the ventral surface of the kid- 
ney, towards its outer border. 


b. [Minute structure. The 
superficial layer of the adrenals 
consists of solid, rounded, or 
elongated groups of polygonal 
cells, containing numerous fat- 
granules; these represent the 
cortical substance of the corre- 
sponding organs of higher ani- 
mals. The medullary part is 
present only in small quantity ; 
it consists of small groups of 
polygonal cells, placed between 
trabeculae of connective-tissue ; 
both trabeculae and cell-groups 
are covered with an endothelium. 
The whole organ is surroundeu 
by a connective-tissue capsule, 


The male urino-genital organs. 


Ao Aorta. è d 

CL. Cloaca. which sends in trabeculae to 

Cv Inferior vena cava. 

FK Fat-body. support the parenchyma (Hoff- 

N Kidney. 

S, Sr Openings of ureters. mann) à ; 

ie No nerves have been traced into 
r reter. 

Vr Renal veins. these organs (Eberth).] 


t Appearance of ureters on the ven- 
tral surfaces of kidneys. 


IV. THE FAT-BODIES. 


a. General description. The fat-bodies (Fig. 226) are bright 
yellow, lobulated bodies, placed in front of the testes and ovaries 
respectively. The greater portion of each organ lies parallel to the 
long axis of the body, and from its anterior, posterior, and external 


THE FAT-BODIES. 349 


borders are given off finger-like processes ; these may divide dicho- 
tomously either near the base or more peripherally. The external 
processes are much the longest, and in the male often conceal the 
greater part of the testis (Fig. 226 FA). The organs vary greatly 
in size with the season of the year. 


Two preparations from the fat-body of Rana esculenta 1.—G. H. 


I. Section of fat-body, stained with borax-carmine (Hartnack, Oc. I, Syst. 7). 
b Fat-cells. 
€ Adenoid tissue, 


II. Three lobes of fat-body of Rana esculenta ; coarsely injected (Hartnack, Oc. I, Syst, 3). 
Arteries striped. Veins shaded. 


b. [Minute structure. Each organ is completely surrounded by 
peritoneum, under which is a very fine layer of connective-tissue. 
The interior of the organ (Fig. 227 I) consists of large fat-cells 
with small patches of adenoid tissue interspersed. The organs are 
extremely vascular; each lobe has a main artery which gives off 
lateral branches: each of these immediately divides to form two 
vessels, which run in opposite directions and almost parallel with 
the main stem; the vessels then break up into a fine network of 
capillaries. ] 


1 From specimens collected in November. 


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tars Ê Pabst eng ee tel intestate et as 
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SECIION. VILL 


THE SKIN AND THE SENSE-ORGANS. 


o>, 


Ki 
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“y 
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THE SKIN AND THE SENSE-ORGANS. 


LITERATURE. 


I. THE SKIN. 


Ascherson, Ueber die Hautdrüsen der Frésche. Arch. f. Anat. u. Physiol. 1810, 
p- 15. 

Axmann, Beitrige zur mikroskopischen Anatomie und Physiologie des Ganglien- 
nervensystems. 1853. 

de Betta, Erpétologia delle provincie Venete e del Tirolo meridionale. 1857. 

” Biesiadecki, Ueber Basenbildung und Epithelregeneration an der Schwimmhaut 
des Frosches. Untersuchungen aus d. Krakauer path.-anatom. Institut. 1872, 
pp. 60-84. Abstract in Centralbl. f. d. med. Wiss. 1873, No. 7, p. 106. 

Bimmermann, E. H., Ueber den Einfluss der Nerven auf die Pigmentzellen des 
Frosches. Dissert. Strasburg, 1878. 

Bimmermann, E. H., Ueber den Einfluss der Nerven auf die Pigmentzellen des 
Frosches. Centralbl. f. d. med. Wiss. 1879, p. 545. 

de Blainville, M. H. M. Ducrotay, De l'Organisation des animaux. Paris, 1822, 
PP. 142, 225. 

Bolaw, Beitrag zur Kenntniss der Amphibienhaut. Gottingen, 1866. 

Bruch, Beiträge zur Naturgeschichte und Classification der nackten Amphibien. 
Wiirzburger naturwiss. Zeitsch. 1864. Vol. III. 

Briicke, Untersuchungen über den Farbenwechsel des afrikanischen Chamaeleon. 
Sitzungsb. der Wiener Acad. 1852. Vol. IV, p. 196. 

Bugnion, Recherches sur les organes sensitifs qui se trouvent dans l’épiderme du 
Protée et de ?Axolotl. Dissert. Zürich. 

Canini, A., Die Endigungen der Nerven in der Haut des Froschlarvenschwanzes. 
Arch. f. Anat. u. Physiol. 1880, pp. 143-153. 

Ciaccio, J. V., Intorno alla minuta fabbrica della pella della Rana esculenta. 
Palermo, 1866. Giornale di Scienze naturali ed economiche. Vol. II, pp. 
103-158. 

Ciaccio, J. V., On the distribution of the nerves to the skin of the frog, with 
physiological remarks on the ganglia connected with the cerebro-spinal nerves. 
Trans. Micros. Soc. London, 1864. Vol. XII, pp. 15-31. 

Czermak, J. N., Ueber die Hautnerven des Frosches. Arch. f. Anat. u. Physiol. 
1849, p. 252. 

Da Collin, Danemarks Froer og Tudser. Naturhist. Tidsskrift. 1870. 

Dewitz, Ueber das verschiedene Aussehen der gereizten und ruhenden Driisen im 
Sehenballe des Laubfrosches. Biol. Centralbl. 1883, p. 558. 

Dogiel, Neue Untersuchungen über den pupillenerweiterden Muskel, etc. Arch. f. 
mik. Anat. 1886. Vol. XX VII, p. 403. 

Duméril et Bibron, Erpétologie générale. 1841. Vol. VIII. 


Aa 


354 THE SKIN AND THE SENSE-ORGANS. 


Eberth, C. J., Untersuchungen zur normalen und path. Anatomie der Froschhaut. 
Leipzig, 1869. 

Eberth, C. J., Zur Entwickelung der Gewebe im Schwanze der Froschlarven. 
Arch. f. mik. Anat. 1866. Vol. II, pp. 490-503. 

Eckhard, Ueber den Bau der Hautdrüsen der Krôten und die Abhingigkeit der 
Entleerung ihres Secretes vom centralen Nervensystem. Arch. f. Anat. u. 
Physiol. 1849. 

Ehrmann, S., Ueber Nervenendigungen in den Pigmentzellen der Froschhaut. 
Sitzungsb. der Wiener Acad. 1882. Vol. LX XXIV, Pt. III, pp. 165-170. 
Engelmann, T. W., Pfliiger’s Arch. f. d. ges. Physiol. 1871, Vol. IV, p. 321, and 

1872, Vol. V, pp. 500-513. (Contractile glands in skin of frog.) 

Harless, E., Ueber die Chromatophoren des Frosches. Zeitsch. f. wiss. Zool. 1854, 
Vol. V, p. 372; also in Miinchener Gelehrten Anzeiger, 1853, No. 35. 

Harley, G., On the organs of cutaneous respiration; principally on those of Rana 
temporaria. Trans. Micros. Soc. London, 1857. Vol. V, p. 148. 

Hensche, A., Ueber die Driisen und glatten Muskeln in der äusseren Haut von 
Rana temporaria. Zeitsch. f. wiss. Zool. 1856. Vol. VII, p. 273. 

Henslow, Way in which toads shed their skin. Annals of Nat. History, 1850, 
p- 69. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig und 
Heidelberg, 1873-1878. Vol. VI. 

Huber, O., Ueber Brustwarzen bei Rana temporaria, L. Zeitsch. f. wiss. Zool. 1887. 
Vol. XLV, p. 664. ; 

Huizinga, D., Untersuchungen über die Innervation der Gefäsze in der Schwimm- 
haut des Frosches. Pflüger’s Arch. 1875. Vol. XI, p. 207. 

Huxley, H. T., Tegumentary organs. Todd and Bowman’s Cyclopedia of Anat. 
and Physiol. p. 500. 

Klein, E., On the lymphatic system of the skin and mucous membranes. Quart. 
Journ. Micros. Sci. 1881. Vol. XXI, pp. 379-406. 

Kôlliker, A., Stiftchenzellen in der Epidermis von Froschlarven. Zoolog. Anzeiger. 
1885. 

Krause, Handbuch der Gewebelehre. 1862. 

Krukenberg, C. F. W., Die Hautfarbstoffe der Amphibien, in Vergleich. physiol. 
Studien, by same author, 1882, pp. 43-49. 

Kutschenko, N., Ueber die Krappfirbung der Froschgewebe. Arch, f. mik. Anat, 
1882. Vol. XXVIII, pp. 360-364. 

Langer, Ueber das Lymphgefässsystem des Frosches. Wiener Sitzungsberichte. 
1867. Vol. LV, pp. 593-636. 

Langerhans, Anat.-hist. Untersuchungen über Fische und Reptilien. Berlin, 
1853. Journal de Medicine. Vol. XI. 

Leboucq, H., Recherches sur le développement et la terminaison des nerfs chez 
les larves des Batraciens. Bull. de l’acad. roy. de Belgique. 1876. Vol. XLI, p. 4. 

‘Leydig, F., Histologisch-anatomische Untersuchungen über Fische und Reptilien. 


1853. 
Leydig, F., Tastkérperchen und Muskelstruktur. Arch. f. Anat. u. Physiol. 1856, 
pp. 150-150. 


Leydig, F., Lehrbuch der Histologie. 1857. 

Leydig, F., Ueber die Nervenendigung in den sogenannten Schleimkanälen der 
Fische und über entsprechende Organe der durch Kiemen athmenden Amphi- 
bien. Arch. f. Anat. u. Physiol. 1861. 

Leydig, F., Ueber die Organe eines sechsten Sinnes. Nov. act. acad. Leop. Carol, 
1868. Vol. XXXIV, pp. 1-102. 

Leydig, F., Ueber die allgemeinen Bedeckungen der Amphibien. Arch. f. mik. 
Anat. 1875 Vol. XII, p. 119. 

Leydig, F., Ueber die Schleichenlurche. Zeitsch. f. wiss. Zool. Vol. XVIII. 


LITERATURE. Sue 


Leydig, F., Ueber die Schwanzflosse, Tastkérperchen und Endorgane der Nerven 
bei Batrachiern. Arch. f. mik. Anat. 1876. Vol. XII, pp. 513-527. 

Leydig, F., Die anuren Batrachier der deutschen Fauna. Bonn, 1877, p. 123. 

Lister, J., On the cutaneous pigmentary system of the frog. Phil. Trans. 1857. 
Vol. CXLVIII, p. 627. 

Macallum, A.B., The nerve terminations in the cutaneous epithelium of the tad- 
pole. Quart. Journ. Micros. Sci. 1886. Vol. XX VI, p. 53. 

Mayer, A., Ueber das Epithelium bei den Amphibien. Froriep’s Notizen, 1839. 
Vol. IX, coll. 49-51. 

Menke, Rana rubita, Linn. Zeitschr. Isis von Oken. 1827. Vol. XX, p. 172. 

Merkel, Ueber die Endigungen der sensiblen Nerven in der Haut der Wirbelthiere. 
Rostock, 1880. 

Meyer, Ueber die Abhiingigkeit der Gefäisse und Pigmentzellen beim Frosch von 
dem Nerveneinfluss. Virchow’s Arch. 1854. Vol. VI, p. 581. 

Openchowski, T., Histologisches zur Innervation der Drüsen. Pflüger’s Arch. 
1882. Vol. XXVII, pp. 223-232. 

Pfitzner, W., Die Epidermis der Amphibien. Morph. Jahrb. 1880. Vol. VI, 
p. 469. 

Rainey, On the structure of the cutaneous follicles of the toad. Quart. Journ. 
Micros. Sci. Vol. III, p. 257. 

Roesel, Historia natur. rana. nostrat. Niirnberg, 1758, p. 3, ete. 

Rudneff, Ueber die epidermiodale Schicht der Froschhaut. Arch. f. mik. Anat. 
1865. Vol. I, p. 295. 

Sattler, E. E., Die Verwendung des Lapisstiftes zur Untersuchung der Epithelien. 
Arch. f. mik. Anat. 1882. Vol. XXI, p. 672. 

Schneider, Historia amphibiorum. 1739. 

Schultze, F. E., Epithel und Drüsenzellen. Arch. f. mik. Anat. 1867. Vol. III, 
PS: 

Schultze, F. E., Ueber cuticulare Bildungen und Verhornung von Epithelzellen bei 
den Wirbelthieren. Arch. f. mik. Anat. 1869. Vol. V, p. 295. 

Schulize, M., Ueber die Nervenendigung in der Netzhaut des Auges bei Menschen 
und Thieren. Centralbl. f. med. Wiss. 1869, p. 885. 

Stieda, L., Ueber den Bau der Haut des Frosches. Arch. f. Anat. u. Physiol. 1865, 
pp. 52-66. 

Stricker, S., and Spina, A., Untersuchungen über die mechan. Leistungen d. 
acinésen Drüsen. Wiener med. Jahrb. 1880, p. 355; und Wiener Sitzungsb. 
1880. (Skin and Membrana nictitans.) 

Swammerdam, J., Biblia naturae. Vol. II, p. 808. 

Szcesny, Beiträge zur Kenntniss der Textur der Froschhaut. Dissert. inaug. Dorpat, 
1867. 

Turner, Way in which toads shed their skins. Annals of Nat. History, 1850, 
Pp. 430. 

Wagner, R., Handworterbuch der Physiologie. Vol. III, p. 389. 

Walter, Ueber die Driisen des Daumenballens des Froschmiinnehens. Verhandl. d. 
naturf. Vereins der pr. Rheinlande und Westphalen. 1851, p. 351. 

v. Wittich, Die griine Farbe der Haut unserer Früsche, etc. Arch. f. Anat. u. 
Physiol. 1854, p. 41. 

v. Wittich, Entgegnung auf Herm. Harless’s über die Chromatophoren des Frosches. 
Arch. f. Anat. u. Physiol. 1854, p. 264. 


396 THE SKIN AND THE SENSE-ORGANS. 


II. SPECIAL ORGANS OF TACTILE SENSATION. 


a. The lateral sense-organs. 


Beard, J., On the segmental sense-organs of the lateral line and on the morphology 
of the vertebrate auditory organs. Zool. Anz. 1884. Vol. VII, p. 162. 

Bugnion, E., Recherches sur les organes sensitifs qui se trouvent dans l’épiderme 
du Protée et de l’Axolotl. Dissert. inaug. Zürich. Tire du Boll. No. 7, de la 
société vaucloise des Sc. nat. Vol. XII. Lausanne, 1873. Verhandl. d. 
schweiz. naturforsch. Gesells. Zürich, 1873.. Vol. LVI, p. 49. 

Froriep, A., Ueber Anlagen von Sinnesorganen am Facialis, Glossopharyngeus und 
Vagus. Arch. f. Anat. u. Physiol. 1885. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig and 
Heidelberg, 1873-1878. 

v. Kôlliker, A., Ueber neue Sinnesorgane von Froschlarven. Sitzungsb. Wtirzburg. 
1885, p. 79- 

Krause, W., Die Nervenendigung innerhalb der terminal Kérperchen. Arch. f. 
mik. Anat. 1880. Vol. XIX, pp. 53-137. 

Leydig, F., Ueber die Organe eines sechsten Sinnes. Nova acta Acad. Leopold. Carol. 
Dresden, 1868. Vol. XXXIV, pp. I-102. 

Leydig, F., Ueber die allgemeinen Bedeckungen der Amphibien. Arch. f. mik. 
Anat. 1875. Vol. XII, pp. 513-527. 

Leydig, F., Ueber Tastkôrperchen und Muskelstructur. Arch. f. Anat. u. Physiol. 
1856, p. 150. 

Malbranc, M., Bemerkung betreffend die Sinnesorgane der Seitenlinie der Amphi- 
bien. Centralbl. f. med. Wiss. 1875, p. 5. 

Malbranc, M. Von der Seitenlinie und ihren Sinnesorganen bei Amphibien. 
Zeitsch. f. wiss. Zool. 1876. Vol. XXVI, pp. 24-86. 

Schultze, E E., Ueber die Nervenendigung in den sogenannten Schleimkanälen 
der Fische und iiber entsprechende Organe der durch Kiemen athmenden 
Amphibien. Arch. f. Anat. u. Physiol. 1861, p. 750. 

Schultze, F. E., Ueber die Sinnesorgane der Seitenlinie bei Fischen und Amphi- 
bien. Arch. f. mik. Anat. 1870. Vol. VI, p. 62. 


b. The touch-corpuscles of Golgi. 


Golgi, C., Della terminazione dei nervi nei tendini e di un nuovo apparato nervoso 
terminale musculo-tendineo. Atti della Societi Italiana di scienze naturali. 
Milan, 1879. Vol. XXI; and abstracted in Centralbl. f. med. Wiss. 1879, 
P. 725. 

Golgi, C., Intorno alla distribuzione e terminazione dei nervi nei tendini dell’ uomo 
e di altri vertebrali. Estratto dai Rendiconti del R. Istituto Lombardo. Serie 
II. Vol. XI. Fase. IX. Milan, 1878. Abstract in Centralbl. f. med. Wiss. 
1879. Vol. 41, p. 725. 

Lowe, L., Ueber eine eigenthiimliche Art von Gelenknervenkérperchen beim 
Frosch. Arch. f. mik. Anat. 1880. Vol. XVI, p. 613. 


III. THE ORGANS OF TASTE. 


Beale, L. 8., New observations upon the minute anatomy of the frog’s tongue. Phil. 
Trans. 1865, p. 443. 

Biedermann, W., Ueber morphologische Veriinderungen der Zungendriisen des 
Frosches, ete. Wiener acad. Sitzungsb. 1882. Vol. LXX XVI, Pt. III, p. 67. 


LITERATURE, 357 


Billroth, T., Ueber die Epithelzellen der Froschzunge, etc. Arch. f. Anat. u. 
Physiol. 1858, p. 159. 

Engelmann, T. W., Ueber die Endigungsweise der Geschmacksnerven des Frosches. 
Centralbl. f. med. Wiss. 1867, p. 785. 

Engelmann, T. W., Ueber die Endigungen der Geschmacksnerven in der Zunge 
des Frosches. Zeitsch. f. wiss. Zool. 1868. Vol. XVIII, p. 142. 

Engelmann, T. W., Die Geschmacksorgane. Stricker’s Handbuch der Gewebelehre. 
1872. 

Fixsen, C., De linguae raninae structura. Dorpat, 1857. 

Gottschau, M., Ueber Geschmacksorgane der Wirbelthiere. Biol. Centralbl. 1882, 
pp. 240-248. 

Hartmann, R., Ueber die Endigungsweise der Nerven in den Papillae fungiformes 
der Froschzunge. Arch. f. Anat. u. Physiol. 1863, p. 634. 

Hoyer, Mikroskopische Untersuchungen über die Zunge des Frosches. Arch. f. 
Anat. u. Physiol. 1859, p. 481. 

Hoyer, Ueber die Epithelzellen der Froschzunge, ete. Arch. f. Anat. u. Physiol. 
1858, p. 163 ; also in Deutscher Klinik, 1857. No. 21. 

Hyrtl, Ueber abwickelbare Gefisskniuel in der Zunge der Batrachier. Wiener 
Acad. Sitzungsb. 1863. Vol. XLVIII, Pt. I, p. 437. 

Key, E. A., Ueber die Endigungsweise des Geschmacksnerven in der Zunge des 
Frosches. Arch. f. Anat. u. Physiol. 1861, p. 329. 

Lépine (On the nerve supply of the glands of the tongue). Arbeiten aus d. 
physiol. Anstalt zu Leipzig, 1870, p. 113. 
Molin, R., Ueber die Theilung der Nervenprimitivréhren in den Papillae fungi- 
formes der Froschzunge. Wiener acad. Sitzungsb. 1849. Vol. III, p- 183. 
Schultze, F. E., Die Geschmacksorgane der Froschlarven. Arch, f. mik. Anat. 
1870. Vol. VI, p. 407. 

Waller, A., Minute structure of the organ of taste in vertebrate animals. Proc. 
Roy. Soc. 1848. Vol. V, p. 751. 

‘Waller, A., Minute structure of the papillae and nerves of the tongue of the frog 
and toad. Phil. Trans. 1848. Pt. I, p. 139. 

Waller, A., Microscopic examination of some of the principal tissues of the tongue, 
ete. Phil. Mag. 1847. Vol. XXX, p. 277. 


IV. THE NOSE. 


Babuchin, Das Geruchsorgan, in Stricker’s Handbuch der Gewebelehre. 1872, 
p- 964. 

de Blainville, M. H. M. Ducrotay, L'Organisation des animaux. Paris, 1822, 
p. 328. 

Blaue, J., Untersuchungen über den Bau der Nasenschleimhaut bei Fischen und 
Amphibien, namentlich über Endknorpel als Endapparate des Nervus olfactorius. 
Arch. f. mik. Anat. 1884. Vol. XXX, pp. 231-309. Zool. Anzeiger. Vol. V, 
pp. 657-680. 

Born, G., Ueber die Nasenhühlen und den Thränennasengang der Amphibien. 
Morph. Jahrb. 1875. Vol. II, p. 4. 

Born, G., Ueber die Nasenhühlen und den Thränennasengang der Amphibien. 
Breslau. Habilit.-Schrift. 1877. 

Born, G., Die Nasenhühlen und der Thränennasengang der amnioten Wirbelthiere. 
Morph. Jahrb. 1879. Vol. V, p. 62. 1882. Vol. VIII, pp. 188-232. i 

v. Brunn, Die Membrana limitans olfactoria. Centralbl. f. med. Wiss. 1874, 
p- 709. 

v. Brunn, Untersuchungen über das Riechepithel. Arch. f. mik. Anat. 1875. Vol. 
XI, pp. 468-478. 


308 THE SKIN AND THE SENSE-ORGANS. 


v. Brunn, Weitere Untersuchungen über das Riechepithel u. sein Verhalten zum 
N. olfactorius. Arch. f. mik. Anat. 1880. Vol. XVII, p. 141. 

Cisoff, Zur Kenntniss der Regio olfactoria. Centralbl. f. med. Wiss. 1874, pp. 
689-691. 

Cisoff, Zur Frage über die Endigung der Riechnerven beim Frosche. Arbeiten 
der naturf. Gesells. an der Universität Kassan. 1879. Vol. VIII (in 
Russian). 

Clarke, J. Lockhart, Ueber den Bau des Bulbus olfactorius und der Geruchsschleim- 
haut. Zeitsch. f. wiss. Zool. 1862. Vol. XI, p. 31. 

Colossanti, Untersuchungen über die Durchschneidung des N. olfactorius bei 
Fréschen. Arch. f. Anat. u. Physiol. 1875. 

Dirkinck-Holmfield-Christmas, J., Experimentalle Undersügelen Bijgningen. 
Nordiskt medicinskt Arkiv., 1883. Vol. XX VI, pp. 50-60. 

Dogiel, A., Ueber die Drüsen der Nasenschleimhaut, besonders die Bowmanschen 
Drüsen. Arch. f. mik. Anat. 

Dogiel, A., Ueber den Bau des Geruchsorgans bei Garroirren, Knochenfischen, 
und Amphibien. Arch. f. mik. Anat. 1887. Vol. X XIX, p. 74. 

Dogiel, A., Ueber den Bau des Geruchsorgans bei Fischen und Amphibien. Biol. 
Centralbl. Vol. I, pp. 428-431. 

Dogiel, A., Ueber die Driisen d. Regio olfactoria. Arch. f. mik. Anat. 1885. Vol. 
XX VI, p. 50. 

Ecker, E., Bericht über die Verhandl. der Gesellschaft für Beford. der Naturw. zu 
Freiburg, 1855, p. 199; and in Zeitsch. f. wiss. Zool. 1856, Vol. VIII, p. 303. 

Eckhard, C., Beitriige zur Anatomie und Physiologie. Pt. I, 1855, p. 77. 

Eckhard, C., Ueber die Endigungsweise der Geruchsnerven. Beitrage zur Anat. u. 
Physiol. Giessen, 1882. Vol. I, p. 77. 

Erichsen, J., De textura nervi olfactorii ejusque ramorum. Dissert. inaug. 1857. 

Exner, S., Untersuchungen iiber die Riechschleimhaut des Frosches. Sitzungsb. 
der Wiener Acad. 1871. Vol. LXIII, Pt. II, p. 44. 

Exner, S., Weitere Studien über die Structur der Riechschleimhaut bei Wirbel- 
thieren. Sitzungsb. der Wiener Acad. 1872. Vol. LXV, Pt. ITI, p. 7. 

Exner, S., Fortgesetzte Studien über die Endigungsweise des Geruchsnerven. 
Sitzungsb. der Wiener Acad. 1878. Vol. LXX VI, Pt. ITI, p. 171. 

Gastaldi, Nuove Ricerche sovra la terminazione del nervo olfatt. Mem. della 
reale Acad. della scienze di Torino. 1858. Vol. XVII, Series II, p. 369. 

Hoffmann, Lehrbuch der Anatomie der Sinnesorgane. 

Hoffmann, C. K., Ondersockingen over den anat. bouw van de membrana, olfactoria 
en het periph. uitiende van den Nervus olfactorius. Dissert. inaug. 1866. 
Hoffmann, C. K., Amphibia in Bronn’s Klassen und Ordnungen des Thierreichs. 

Leipzig und Heidelberg, 1873-1878. Vol. VI, pp. 335-347. 

Horn, H., Ueber die Endschlingen des Geruchsnerven (nervus olfactorius) der Rana 
temporaria. Arch. f. Anat. u. Physiol. 1850. 

Hoyer, H., De tunica mucosa narium textura. Dissert. inaug. Berol., 1857. 

Hoyer, H., Ueber die mikroskopischen Verhältnisse der Nasenschleimhaut, etc. 
Arch. f. Anat. u. Physiol. 1860, p. 50. 

Langer, C., Ueber das Lymphgefisssystem des Frosches. Wiener Acad. Sitzungsb, 
1867. Vol. LV, Pt. I, p. 615. 

Legal, E., Die Nasenhohlen und der Thriinennasengang der amnioten Wirbelthiere. 
Morph. Jahrb. 1882. Vol. VIII, p. 353. E 

Martin, Studies from the physiological laboratory in the University of Cambridge. 
Pt TS 72 

Paschutin, V., Ueber den Bau der Schleimhaut der Regio olfactorio beim Frosch. 
Medicinisky Wjestnik. 1872. Nos. 38-40. 

Paschutin, V., Ueber den Bau der Schleimhaut der Regio olfactoria des Frosches. 
Arbeiten aus d. phys. Laborat. Leipzig, 1873. 


LITERATURE. 359 


Paulsen, E., Ueber die Driisen der Nasenschleimhaut besonders die Bowman’schen 
Drüsen. Arch. f. mik. Anat. 1886. Vol. XX VI, pp. 307-321. 

Piersol, G. A., Beïträge zur Histologie der Harderschen Drüsen der Amphibien. 
Arch. f. mik. Anat. 1887. Vol. XXIX, p. 594. 

Reichert, B., Arch. f. Anat. u. Physiol. 1857, p. 39. Bericht. 

Schultze, M., Ueber die Endigungsweise des Geruchsnerven und die Epithelial- 
gebilde der Nasenschleimhaut. Monatsb. Acad. z. Berlin. 1856, p. 504. 

Schultze, M., Untersuchungen über den Bau der Nasenschleimhaut, namentlich die 
Structur und Endigungsweise der Geruchsnerven bei dem Menschen und den 
Wirbelthieren. Halle, 1862. Vol. VII, pp. 32-41; also published in Berlin, 
1875. Abstract in Centralbl. f. med. Wiss. 1863, p. 97. 

Seeberg, Disq. microsc. de textura membr. pitnit. nasi. Dorpat, 1855. Dissert. 
inaug. 

Stirling, W., and Macdonald, The minute structure of the palatine nerves of the 
frog and the termination of nerves in blood-vessels and glands. Journ. of Anat. 
and Physiol. 1884. Vol. XVII, p. 293. 

Wiedersheim, R., Ueber die Kopfdriisen der Amphibien. Sitzungsb. d. phys.-med. 
Gesell. in Würzburg, 1876. Febr. 5. 

Wiedersheim, R., Die Kopfdriisen der geschwänzten Amphibien und die Glandula 
intermaxillaris der Anuren. Zeitsch. f. wiss. Zool. 1876. Vol. XXVII, 
pp- I-50. 

Wiedersheim, R., Lehrbuch der vergl. Anatomie der Wirbelthiere. Pt. I. Jena, 
1882. 


V. THE EAR. 


Chatin, J., Recherches pour servir a l’histoire du noyau dans l’épithelin auditif 
des batrachiens. Annales des sciences nat. Zool. 1883. Vol. XVI, Series VI, 
Art. No. 2. 

Comparetti, A., in gymnasio patavino observationes anatomicae de aure interna 
comparatae. Patavii, 1789. 

Crombie, J. M., On the membrana tympani. Journ. of Anat. and Physiol. 1883, 
Pp: 523-536. 

Cuvier, G., Leçons d’anatomie comparée. Paris, 1800. Vol, II. 

Deiters, O., Ueber das innere Gehürorgan der Amphibien, Arch. f. Anat. u. Physiol. 
1862, p. 277. 

Eberth, C. J., Zur Kenntniss der Verbreitung der glatten Muskelfasern (Tympanic 
membrane). Zeitsch. f. wiss. Zool. 1863. Vol. XII, p. 364. 

Ferré, Etude sur la crête auditive chez les vertébrés. Ann. Sci. Nat. Bordeaux, 
Wolk 1p ivigs diate 

Hasse, C., Die Histologie des Bogenapparates und des Steinsacks der Früsche, 
Zeitsch. f. wiss. Zool. 1868. Vol. XVIII, p. 71. 

Hasse, C., Das Gehürorgan der Früsche. Zeitsch. f. wiss. Zool. 1868. Vol. XVIII, 
P- 359- 

Hasse, C., Das knécherne Labyrinth der Früsche. Anatomische Studien, 2nd Pt. 
LO 25) Dae 

Hasse, C., Die vergleichende Morphologie und Histologie des häutigen Gehürorgans 
der Wirbelthiere. Supplement to the Anatomische Studien. Vol. I, 1873. 

Hasse, C., Die Lymphbahnen des inneren Ohres der Wirbelthiere. In the Anato- 
mische Studien of Hasse, 1873. No. XIX. 

Hasse, C., Das Gehürorgan der Wirbelthiere von Gustav Retzius, Arch. f, Ohren- 
heilk. 1884 Vol. XXI, pp. 314-324. 

Hoffmann, Lehrbuch der Anatomie der Sinnesorgane. 

Hoffmann, Bronn’s Klassen und Ordnungen des Thierreichs. Leipzig and Heidel- 
berg, 1873-1878. Vol. VI, pp. 304-335. 


360 THE SKIN AND THE SENSE-ORGANS. 


Ibsen, J., Anatomiske Undersügelser over orets Labyrinth. Udgivet vet P. L. 
Panum. Kjobenhawn, 1846 (abstract in Virchow and Hirsch’sJahresb. 1881,p.88). 

Kuhn, Ueber das häutige Labyrinth der Amphibien. Arch. f. mik. Anat. 1880. 
Vol. XVII, pp. 479-550. 

Kuhn, Zur Anatomie des inneren Ohres der Wirbelthiere. Compt. rend. du III 
Congrès internat. d’Otologie à Bale, 1884, pp. 228-238. 

Leydig, F., Lehrbuch der Histologie des Menschen und der Thiere. Frankfurt a. 
M. 1857. 

Leydig, F., Ueber neuere den Aquaeductus vestibuli des Menschen und der Thiere 
betreffende Forschungen. Sitzungsb. d. Niederrheinischen naturf. Gesellsch. in 
Bonn, 1874. Vol. XXXIV, p. 124. 

Moldenhauer, Vergleichende Histologie des Trommelfells. Arch. f. Ohrenheilk. 
1878, p. I. 

Pappenheim, S., Ueber Verbreitung der Flimmerbewegung. Arch. f. Anat. u. 
Physiol. 1840, p. 533. 

Retzius, G., On hürselnervens ändningssätt i maculae och cristae acusticae. Nor- 
diskt medicinskt arkiv. 1871. Vol. III. 

Retzius, G., Zur Kenntniss der Morphologie des inneren Ohres bei Wirbelthieren. 
Nord. Med. Ark. 1880. Vol. XII, No. r2. 

Retzius, G., Zur Kenntniss des Gehürorgans der Wirbelthiere. Arch. f. Anat. u. 
Physiol. 1880, pp. 235-244. 

Retzius, G., Das Gehürorgan der Wirbelthiere. Pts. I and II, 1881. Stockholm. 

Retzius, G., Das Gehürorgan der Wirbelthiere. Congr. internat. de Copenhagen. 
Anatomy, p. 29. 

Retzius, G., Das Gehürorgan der Fische und Amphibien. Pt. I, 1881. Stockholm. 

Retzius, G., Zur Kenntniss der Morphologie des inneren Ohres bei Wirbelthieren. 
Nord. Med. Ark. 1880. Vol. XII, p. 6. 

Retzius, G., Ueber die peripherische Endigungsweise der Gehérnerven. Biol. 
Untersuch. Stockholm and Leipzig, pp. 51-61. 

Schultze, F. E., Zur Kenntniss der Endigungsweise der Hérnerven bei Fischen und 
Amphibien. Arch. f. Anat. u. Physiol. 1862, p. 381. 

Stannius, H., Handbuch der Zootomie von v. Siebold und Stannius. Berlin, 1856. 
2nd Edit., Pt. II. 

. Tafani, A., L’organo dell udito. Firenze, 1885. 

Waldeyer, W., Hürnerv und Schnecke. Stricker’s Handbuch der Gewebelehre, 
pp. 915-963. 

Weber, E., Amtlicher Bericht über die neunzehnte Versammlung deutscher Natur- 
forscher und Aerzte in Braunschweig im Sept. 1841. Printed Braunschweig, 
1842. 

Windischmann, De penitiori auris in amphibiis structura Lipsiae, 1831. 


VI. THE EYE. 


a. The cornea and sclerotic. 


Angelucci, A., Ueber den Bau u. die Entwickelung des vorderen Uvealtractus der 
Vertebraten. Centralbl. f. d. med. Wiss. 1879. No. 24, p. 417. 

Altmann, R., Ueber die Verwerthbarkeit der Corrosion in der mikroskopischen 
Anatomie. Arch. f. mik. Anat. 1879. Vol. XVI, p. 471 (Corneal corpuscles). 

Arnold, J., Die Vorgänge bei der Regeneration epithelialer Gebilde. Virchow’s 
Arch. 1869. Vol. XLVI, p. 168. 

Arnold, J., Experimentale Untersuchungen iiber die Entwicklung der Blutcapil- 
laren. Virchow’s Arch. 1871. Vol. LIII, p. 70. 1872. Vol. LIV, p. 1. 


LITERATURE. 361 


Boddaert, Zur Histologie der Cornea. Centralbl. f. med. Wiss. 1871, p. 337. 

Ciaccio, J. V., On the nerves of the cornea and of their distribution in the corneal 
tissue of man and animals. Trans. Micros. Soc. London, 1863. Vol. XI, p. 77. 

Clasow, E., Om corneal epithel. Upsala likareférenings forhandlingar. 1869. Vol. 
LV; pe 4h 

Cohnheim, J., Ueber die Endigung der sensiblen Nerven in der Hornhaut. Vir- 
chow’s Arch. 1867. Vol. XX XVIII, p. 343. 

Durante, F., Sulla terminazione dei nervi della cornea. Richerche fatte nel laborat. 
di anat. normal. Roma, pubbl. dal dott. F. Tocharo. 1873, pp. 81-87. 

Engelmann, T. V., Ueber die Hornhaut des Auges. Leipzig, 1867. 

v. Ewetsky, Ueber das Endothel der Membrana Descemeti. Untersuch. aus d. 
pathol. Institut. Zürich, 1875. Vol. III. 

Frey, H., Handbuch der Histologie und Histochemie. 

Generisch, Zur Lehre von den Saftkanälchen in der Cornea. Med. Jahrb. der 
Gesellsch. d. Aerzte in Wien. 1871, p. 1. 

Guye, A. G., Over bekercellen en in het byzonder over de bekercellen in de mem- 
brana nictitans van den Kikvouch. Nederl. Tydschrift v. Gewesh. 1868. Vol. 
II, p. 135. 

Hansen, A., Untersuchungen über die entziindlichen Veränderungen der Hornhaut- 
kôrper. Wiener Med. Jahrb. 1871, p. 210. 

Harpeck, C., Ueber die Bedeutung der nach Silberimprägnation auftretenden 
weissen liicken- und spaltihnlichen Figuren in der Cornea. Arch. f. Anat. u. 
Physiol. 1864, p. 222. 

Hartmann, R., Ueber die durch den Gebrauch der Hôllensteinlüsung kiinstlich 
dargestellten Lymphgefissanhinge, Saftcaniilchen und epithelähnlichen Bil- 
dungen. Arch. f. Anat. u. Physiol. 1864, p. 235. 

Heiberg, H., Ueber die Neubildung des Hornhaut-Epithels. Wiener Med. Jahrb. 
1871. 

Heisrath, F., Ueber d. Zusammenhang d. vordern Augenkammer mit d. vord. Ciliar- 
venen. Arch. f. mik. Anat. 1878. Vol. XV, p. 209. 

Helfreich, Ueber die Nerven der Conjunctiva und Sclera. Wiirzburg, 1870. 

Henle, J., Handbuch der systematischen Anatomie, 1866. Vol. IT. 

His, W., Untersuchungen über der Bau der Hornhaut, in Verhandlungen der phys.- 
med. Gesellschaft in Wiirzburg. 1856. Vol. IV, p. go. 

His, W., Ueber die Einwirkung des salpetersauren Silberoxydes auf die Hornhaut. 
Schweizerische Zeitsch. f. Heilkunde. 1864. Vol. II, p. 1. 

Hoffmann, F. A., Ueber Contractilitätsvorgänge im vorderen Epithel der Frosch- 
hornhaut. Diss. Berlin, 1868. 

Hoffmann, F. A., Epithelneubildung auf der Cornea. Virchow’s Arch. 1870. 
Vol. LI, p. 373. 

Hosch, F., Ueber die angebliche Contractilität der Knorpelzellen und Hornhaut- 
kôrperchen. Pflüger’s Arch. f. d. ges. Physiol. 1873. Vol. VII, p. 515. 

Hoyer, H., Ueber den Austritt von Nervenfasern in das Epithel der Hornhaut. 
Arch. f. Anat. u. Physiol. 1866, pp. 180-195. 

Hoyer, H., Ueber die Nerven der Hornhaut. Arch. f. mik.Anat.1873. Vol. ITX,p. 220. 

Klebs, E., Das Epithel der hintern Hornhautfliche. Centralbl. f. d. med. Wiss. 
1864, p. 513. 

Klein, E., Some remarks on the finer nerves of the cornea. Monthly Journ. Micros. 
Sci. 1872. Vol. VII, pp. 156-164. 

Klein, E., Beitriige zur Kenntniss der peripherischen Verzweigung markloser Ner- 
venfasern. Centralbl. f. d. med. Wiss. 1871, p. 594. 

Klemensiewicz, R., Karyokinese in den fixen Hornhautzellen bei Entzündung. 
Centralbl. f. d. med. Wiss. 1884, p. 163. 

v. Kôülliker, A., Ueber die Nerven der Hornhaut. Mittheilungen der naturforschenden 
Gesellschaft in Zürich, 1849. 


362 THE SKIN AND THE SENSE-ORGANS. 


v. Kélliker, A., Ueber die Nervenendigungen in der Hornhaut. Würzb. naturw. 
Zeitschr. 1866. Vol. VI, p. 121. f 

Kônigstein, L., Histologische Notizen. Arch. f. Ophthalmologie. 1881. Vol. 
XXVII, p. 56. 

Kônigstein, L., Beobachtungen über die Nerven der Cornea und ihre Gefässe. 
Wiener Sitzungsber. 1877. Vol. LX XVI, Pt. II, p. 17. 

Kônigstein, L., Peobachtungen über die Nerven der Cornea und ihre Gefisse. 
Wiener Sitzungsber. 1877. Vol. LX XVI, Pt. III, p. 37. 

Krause, W., Ueber das vordere Epithel der Cornea. Güttinger Nachrichten, 1870. 
Arch. f. Anat. u. Physiol. 1870. 

Krause, W., Anatomischer Jahresbericht fiir 1871 in Prager Vierteljahrsschrift. 

Kühne, W., Untersuchungen über Protoplasma und die Contractilität. 1864. 

Lavdowsky, M., Das Saugadersystem und die Nerven der Cornea. Arch. f. mik. 
Anat. 1872. Vol. VIII, p. 538. 

Leber, T., Zur Kenntniss der Impriignationsmethoden der Hornhaut und ähnlicher 
Gewebe. Arch. f. Ophthalmologie. 1867. Vol. XIV, p. 300. 

Leydig, F., Lehrbuch der Histologie. 1857. 

Lightbody, W. H., Observations on the comparative anatomy of the cornea of 
vertebrates. Journ. of Anat. and Phys. 1867. Vol. I, p. 15. 

Lipmann, H., Ueber die Endigung der Nerven im eigentlichen Gewebe und im 
hinteren Epithel der Hornhaut des Frosches. Virchow’s Arch. 1869. Vol. 
XLVIII, p. 218. 

Lott, G., Ueber den feineren Bau und die physiologische Regeneration der 
Epithelien, insbesondere des Cornea-Epithels.  Centralbl. f. d. med. Wiss. 
1871. 

Moseley, H. N., Some remarks on the nerves of the cornea of the rabbit and frog. 
Quart. Journ. Micros. Sci. 1871. Vol. XI, p. 261. 

Miller, C. F., Histologische Untersuchungen über die Cornea. Virchow’s Arch. 
1867. Vol. XLI, p. 110. 

v. Recklinghausen, F., Notiz über Silberimprägnation. Virchow’s Arch. 1860. 
Vol. XTX, p. 451. 

v. Recklinghausen, F., Die Lymphgefiisse und ihre Bedeutung zum Bindegewebe. 
Berlin, 1862. 

Robinski, Die Kittsubstanz auf Reaction des Argentum nitricum. Arch. f. Anat. 
u. Physiol. 1871, p. 184. 

Rollett, A., Ueber das Gefiige der Substantia propria corneae. Sitzungsb. Wiener 
Akad. 1859. Vol. XX XIII, p. 516. 

Rollett, A., Ueber die Contractilität der Hornhautkérper und die Hornhauthühlen. 
Centralbl. f. d. med. Wiss. 1871, p. 193. 

Rollett, A. Ueber die Hornhaut. Stricker’s Gewebelehre. 1872, p. 1091. 

Saemisch, T., Beitrige zur normalen und pathologischen Anatomie des Auges 
(Nerves of Cornea). Leipzig, 1862. 

Sattler, E. E., Die Verwendung des Lapisstiftes sur Untersuchung der Epithelien. 
Arch. f. mik. Anat. 1882. Vol. XXI, p. 672. 

Schalygen, C., Ueber Hornhautepithel und besonders über Vermehrung der Zellen 
desselben. Arch. f. Ophthalmol. 1866, Vol. XII, p. 83. 

Schneider, A., Ueber die Vermehrung der Epithelzellen der Hornhaut, Wiirzb. 
naturw. Zeitsch. 1862. Vol. III, p. 105. 

Schwalbe, G., Ueber ein mit Endothel bekleidetes Hühlensystem zwischen Choroidea 
und Sclerotica. Central. f. d. med. Wiss. Berlin, 1868. No. 54. 

Schweigger, Ueber den Bau der Hornhaut, Allg. med. Centralzeitung. Berlin, 
1862. No. 4. 

Schweigger-Seidel, F., Ueber die Grundsubstanz und die Zellen der Hornhaut des 
Auges. Berichte d. math.-physik. Classe der Kénigl, Sächs. Gesellsch. d. 
Wissenschaft. 1869, Vol. XXI, pp. 305-359. 


LITERATURE. 3635 


Stricker, S., Conjunctiva und Sclerotica im Handb. der Lehre von den Geweben des 
Menschen und der Thiere. 1872, p. 1142. 

Swaen, M. A., Des éléments cellulaires et des canaux plastiques dans la cornée de 
la grenouille. Bulletin de l’Acad. roy. de Belgique. 1876. 2nd Series, Vol. 
XLII, pp. 144-183. 

Tamamscheff, T., Ueber die Membrana Demoursiana. Centralbl. f. d. med. Wiss. 
Berlin, 1869. 

Waldeyer, W., Microscopische Anatomie der Cornea, Sclera, Lider und Conjunc- 
tiva, in Handbuch der gesammten Augenheilkunde. 1874. 

Wolff, W., Die Nerven der Cornea. Arch. f. mik. Anat. 1882. Vol. XX, p. 373. 

Zielonko, J., Ueber die Entwicklung und Proliferation von Epithelien und Endo- 
thelien. Arch. f. mik. Anat. 1874. Vol. X, p. 351. 


b. The lens, choroid, iris, appendages, anterior and 
> b] >] 2 
posterior chambers. 


Altmann, R., Ueber Corrosion in der Histologie. Centralbl. f. d. med. Wiss. 1878, 
p. 245- 

Altmann, R., Ueber die Verwerthbarkeit der Corrosion in der mikroskopischen 
Anatomie. Arch. f. mik. Anat. 1879. Vol. XVI, p. 471 (Blood-vessels of the 
choroid), 

Angelucci, A., Ueber den Bau und die Entwickeluny des vorderen Uveatractus der 
Vertebraten. Centralbl. f. d. med. Wiss. 1879, p. 417. 

Arnold, Die Linse. Handbuch der gesammten Augenheilkunde. 1874. 

Barkau, A., Beitriige zur Entwicklungsgeschichte des Auges der Batrachier. 
Wiener Sitzungsber. 1866. Vol. LIV, Pt. I, pp. 70-75. 

Becker, Untersuchungen über den Bau der Linse bei dem Menschen und den Wir- 
belthieren. Arch. f. Ophthalmologie. 1863. Vol. IX, Pt. IT, pp. 1-42. 

Biedermann, W., Zur Histologie und Physiologie der Schleimsekretion (Membrana 
nictitans). Wiener Sitzungsber. 1886. Vol. XCIV. 

Born, G., Ueber die Nasenhéhlen und den Thränennasengang der Amphibien. 
Morph. Jahrb. 1875. Vol. II, p. 4. 

Bubuchin, Die Linse. In Stricker’s Handb. der Gewebelehre. 1872. 

Burow, De vasis sanguif. ran. Diss. Regiomonti, 1838. 

Ciaccio, C. V., Beobachtungen tiber den inneren Bau des Glaskürpers im Auge des 
Menschen und der Wirbelthiere im Allgemeinen. Moleschott’s Untersuchungen. 
1870. Vol. X, p. 385. 

Faber, C., Der Bau der Iris des Menschen und der Wirbelthiere. Leipzig, 1876. 

Frey, Handbuch der Histologie und Histochemie des Menschen. 1874. 

Fubini, S., Beiträge zum Studium der Krystalllinse. Moleschott’s Untersuchungen. 
1876. Vol. XI, p. 291. 

Golubew, Beitriige zur Kenntniss des Baues und der Entwicklungsgeschichte der 
Capillargefiisse des Frosches. Arch. f. mik. Anat. 1869. Vol. V, p. 49. 

Griinhagen, Ueber das Vorkommen eines Dilatator pupillae in der Iris. Zeitsch. 
f. rat. Med. Vol. XXVIII, pp. 178, 186. 

Heisrath, F., Ueber den Zusammenhang der vorderen Augenkammer mit den 
vorderen Ciliarvenen. Arch. f. mik. Anat. 1878. Vol. XV, p. 209. 

Henle, J., Zur Anatomie der Crystalllinse. Abhandl. Gesells. d. Wiss. zu Gottingen. 
1878. Vol. XXIII. 

Henle, J., Zur Entwicklungsgeschichte der Krystalllinse und zur Theilung des 
Zellkerns. Arch. f. mik. Anat. 1882. Vol. XX, p. 413. 

Hirschberg, Zur Dioptric und Ophthalmologie der Amphibienaugen. Arch, f. Anat. 
u. Physiol. 1887, p. 493. 

Iwanoff, Beitriige zur normalen und pathologischen Anatom‘e des Froschglaskorpers. 
Centralbl. f. d. med. Wiss. 1868, p. 129. 


364 THE SKIN AND THE SENSE-ORGANS. 


Klein, E., On the peripheral distribution of non-medullated nerve-fibres (Nerves of 
the nictitating membrane). Quart. Journ. Micros. Sci. 1872. Vol. XII, 
pp- 21-32. 

Koganei, J., Untersuchungen über den Bau der Iris des Menschen und der Wirbel- 
thiere. Arch. f. mik. Anat. 1885. Vol. XXYV, p. 1. 

Koganei, J., Untersuchungen über den Bau der Iris. Sitzungsber. d. Acad. d. Wiss. 
Berlin, 1885, p. 105. ~ 

v. Kolliker, A., Handbuch der Gewebelehre. 1867. 

Langer, C., Ueber das Lymphgefässsystem des Frosches. Wiener Acad. Sitzungsb. 
1867. Vol. LV, Pt. I, p. 603. 

Leydig, F., Anatomisch-histologische Untersuchungen fiber Fische und Reptilien, 
1853. 

Leydig, F., Lehrbuch der Histologie des Menschen und der Thiere. 1857. 

Manz, W., Ueber den Mechanismus der Nickhautbewegung beim Frosche. Berichte 
über d. Verhandl. d. naturforsch. Gesell. Freiburg, 1862. Vol. II, p. 391. 
Moriggia, A., Ueber die beste Darstellungsweise und die Entwicklung der Rührchen 
der Krystalllinse. Moleschott’s Untersuchungen. 1870. Vol. X, p. 658. 
Openchowski, T., Histologisches zur Innervation der Drüsen. Pflüger’s Arch. f. d. 

ges. Physiol. 1882. Vol. XX VII, pp. 223-232. 

Petit, Sur l’œil de la grenouille. Mém. de l’académie d. Sciences, 1737; see also 
Lehrbuch d. vergleich. Anatomie, Stannius, Berlin, 1846, p. 198. 

Robinski, S., Zur Anatomie, Physiologie und Pathologie der Augenlinse des 
Menschen und der Wirbelthiere. Arch. f. Anat. u. Physiol. 1872, p. 178. 
Robinsky, S., Die Augenlinsensterne des Menschen und der Wirbelthiere. Cen- 

tralbl. f. d. med. Wiss. 1877, p. 51. 

Sattler, E. E., Die Verwendung des Lapisstiftes zu Untersuchungen der Epithelien. 
Arch. f. mik. Anat. 1882. Vol. XXI, p. 672. 

Stricker, S., Untersuchungen iiber die capillaren Blutgefiisse in der Nickhaut des 
Frosches. Wiener Sitzungsb. 1865, Vol. LI, Pt. II, pp. 16-27; and Mole- 
schott’s Untersuchungen, 1866, Vol. X, pp. 168-180. 

Stricker, S., Untersuchungen über die mechan. Leistungen d. acirrésen Drüsen. 
Wiener med. Jahrb. 1880, p. 355; also Wiener Sitzungsb. 1880 (Membrana 
nictitans and skin); also in Moleschott’s Untersuchungen. 1870. Vol. X, 
Pp. 237- 

Stricker, S., Studien über den Bau und das Leben der capillaren Blutgefiisse. 
Wiener Sitzungsb. 1866. Vol. LIT, Pt. IT, p. 370. 

Stricker, S., Untersuchungen über die capillaren Blutgefiisse in der Nickhaut des 
Frosches. Moleschott’s Untersuchungen. 1870. Vol. X, p. 168. 

Thin, G., Contribution to the anatomy of the lens. Journ. of Anat. and Physiol. 
1876. Vol. X, p. 223. 

Valentin, Handbuch der Physiologie v. Wagner. 1842. 

Virchow, H., Ueber die Gefässe im Auge und in der Umgebung des Auges beim 
Frosche. Zeit. f. wiss. Zool. 1881. Vol. XXXV, pp. 247-281. 

Virchow, H., Ueber die Gefässe des Kopfes und des Auges des Frosches. Verhandl. 
Wiirzburg. 1881. Vol. XV, p. xxxiv. 

Virchow, H., Mittheilungen zur vergleichenden Anatomie des Wirbelthierauges. 
Versamml, deutsch. Naturf. und Aerzte. Strassburg. 1885, pp. 409, 410. 
Virchow, H., Ueber den ciliaren Muskel des Frosches. Verhandl. d. physiol. 

Gesell. zu Berlin. 1885, p. 571. 

Virchow, H., Ueber die verschiedenen Formen des Ligamentum pectinatum iridis. 
Versamml. d. Naturf. und Aerzte. 1885, p. 409. 

Zimmermann, W., Ueber circumvasale Safträume der Glaskérpergefiisse von Rana 
esculenta. Arch. f. mik, Anat. 1886. Vol. XX VII, p. 410. 


LITERATURE. 365 


ce. The retina. 


Babuchin, Vergleichende histologische Studien. Würzburger naturwissensch. Zeitsch. 
1864, Vol. V, p. 127. 

Beauregard, M. H., Contribution à l'étude du rouge rétinien. Journ. de l’anat. et 
de la physiol. 1879. Vol. XV, p. 161. 

Boll, F., Zur Anatomie und Physiologie der Retina. Berlin. Acad. Monatsber. 
1876, p. 783. 

Dennissenko, G., Vorläufige Bemerkungen zur Lehre über den Bau der Netzhaut. 
Mitt. aus dem embryolog. Institut. d. Wiener Universität, 1850, Vol. II, p. 1; 
Abstract in Centralbl. f. d. med. Wiss. 1880, p. 739. 

Dennissenko, G., Ueber den Bau der äusseren Kürnerschicht der Netzhaut bei den 
Wirbelthieren. Arch. f. mik. Anat. 1881. Vol. XIX, p. 365. 

Dietl, M. J., Beitrag zur Kenntniss des feineren Baues der Stäbchenaussenglieder 
in der Netzhaut des Frosches. Arch. f. Augen- u. Ohrenheilkunde. 1878. Vol. 
VII, pp. 17-24. 

Dobrowolsky, Die Doppelzapfen. Arch. f. Anat. u. Physiol. 1871. 

Dobrowolsky, Zur Anatomie der Retina. Arch. f. Anat. u. Physiol. 1871. 

Ewart, J. C., Notes on the minute structure of the retina and vitreous humour. 
Journ. of Anat. and Physiol. 1875. Vol. IX. 

Ewart, J. C., and Thin, G., On the structure of the retina. Journ. of Anat. and 
Physiol. 1876. Vol. IX, p. 166. 

Frisch, Gestalten des Choroidalpigments. Wiener Sitzungsber. 1868. Vol. LVIII, 
pp. 316-320. 

Heinemann, C., Beiträge zur Anatomie der Retina. Arch. f. mik. Anat, 1877. 
Vol. XIV, p. 400. 

Helfreich, Ophthalmoscopische Mittheilungen über den Purpur der Retina. Cen- 
tralbl. f. d. med. Wiss. 1877, p. 113. 

Henle and Merkel, Ueber die sogenannte Bindesubstanz der Centralorgane des 
Nervensystems. Zeitsch. f. rat. Med. 3rd Series, 1869. Vol. XXXIV. 

Hensen, Ueber das Sehen in der Fovea centralis. Virchow’s Arch. 1867. Vol. 
XXXIX, p. 75. 

Hoffmann, Lehrbuch der Anatomie der Sinnesorgane. 

Hoffmann, Bronn’s Thierbuch. Leipzig and Heidelberg, 1873-1878. Vol. VI, 
Pp. 274—297- 

Hulke, J. W., A contribution to the anatomy of the amphibian and _ reptilian 
retina. Quart. Journ. Micros. Sci. 1864, Vol. IV, p. 236; and London Ophthal- 
mic Hospital Reports, 1864. 

Hulke, J. W., On the retina of amphibia and reptiles. Journ. of Anat. and Physiol. 
Oe Wolly jie. tye 

Kühne, W., Ueber den Sehpurpur. Centralbl. f. d. med. Wiss. 1877, p. 193. 

Kühne, W., Fortgesetzte Untersuchungen über die Retina und die Pigmente des 
Auges. Heidelberger physiol. Untersuch. 1878, Vol. II, p. 89; Abstract in 
Centralbl. f. d. med. Wiss. 1879, p. 276. 

v. Kôlliker, A., Zur Anatomie und Physiologie der Retina.  Verhandl. d. phys.-med. 
Gesellsch. Wiirzburg, 1852. Vol. III, p. 316. 

v. Kôülliker, A., Microscopische Anatomie. 1854. Vol. Il. 

v. Kôlliker, A., Handbuch der Gewebelehre. 1867. É 

Krause, W., Die Nervenendigung in der Retina. Arch. f. mik. Anat. 1876. Vol. 
XII, pp. 742-790. 

Krause, W., Die Nervenendigung innerhalb der terminalen Kérperchen. Arch. f. 
mik. Anat. 1881. Vol. XIX, p. 53. 

Landolt, Beitrag zur Anatomie der Retina vom Frosch, Salamander und Triton. 
Arch. f. mik. Anat. 1871. Vol. VII, p. 81. 


366 THE SKIN AND THE SENSE-ORGANS. 


Leydig, F., Anatomisch-histologische Untersuchungen über Fische und Reptilien. 
1853. 

Leydig, F., Die Farbe der Retina und das Leuchten der Augen. Arch. f. 
Naturgesch. 1877. Vol. XX XIII, p. 8. 

Manz, W., Ueber den Bau der Retina des Frosches. Zeitsch. f. rat. Med. 3rd Series, 
1861. Vol. X, pp. 301-322. 

Manz, W., Die Ganglienzellen der Froschnetzhaut. Zeitsch. f. rat. Med. 3rd Series, 
1866. Vol. XXVIII. 

Merkel, Zur Kenntniss der Stäbchenschicht der Retina. Arch. f. Anat. u. Physiol. 
1870, p. 642. 

Morano, F., Die Pigmentschicht der Retina. Arch. f. mik. Anat. 1872. Vol. 
MEL per: 

Morano, F., Stomata in der Pigmentschicht der Retina. Centralbl. f. d. med. Wiss. 
1875, p. 67. 

Miller, H., Histologie der Netzhaut. Zeitsch. f. wiss. Zool. 1851-52. Vol. III, 
P- 234- 

Müller, H., Ueber sternformige Zellen der Retina. Würzb. Verhandl. 1852. Vol. 
II, pp. 216-218. 

Müller, H., Ueber einige Verhältnisse der Netzhaut bei Menschen und Thieren. 
Wiirzb. Verhandl. 1853. Vol. IV, p. 96. 

Müller, H., and Kélliker, A., Retina-Tafel. Plate XIX in Ecker’s Icones Physiol. 
Leipzig, 1854. 

Müller, H., Observations sur la structure de la rétine de certains animaux. Compt. 
rend. 1856, Vol. XLIII, p. 743; and Annales hist. nat. 1856, Vol. XVIII, 
P: 492. 

Miller, H., Anatomisch-physiologische Untersuchungen iiber die Retina des Men- 
schen und der Wirbelthiere. Zeitsch. f. wiss. Zool. 1857. Vol. VIII, p. 27. 

Miller, W., Ueber die Stammentwicklung des Sehorgans der Wirbelthiere. 
Leipzig, 1874, Festgabe an Carl Ludwig; Abstract in Centralbl. f. d. med. Wiss. 
1877, pp. 372 and 388. 

Ogneff, J., Histogenese der Retina. Centralbl. f. d. med. Wiss. 1881, p. 641. 

Ogneff, J., Ueber die moleculäre Schicht und die sogenannte reticuläre Substanz 
der Retina. Centralbl. f. d. med. Wiss. 1883, p. 801. 

Oppenheimer, L. S., Die Stiibchen in der Netzhaut der Froschembryonen. Schenk’s 
Embryol. Mitt. Wien. 1878, p. 163. 

Ranvier, L., Traité technique d’histologie, sixième fasicule. 1882. 

Ritter, Ueber den Bau der Stäbchen und äusseren Endigungen der Radialfasern an 
der Netzhaut des Frosches. Arch. f. Ophthalmol. 1859. 

Ritter, Zur Histologie des Auges. Arch. f. Ophthalmol. 1868. Vol. XI. 

Schifferdecker, Studien zur vergleichenden Histologie der Retina. Arch. f. mik. 
Anat, 1886. Vol. XXVIII, p. 305. 

Schultze, M., Zur Anatomie und Physiologie der Retina. Arch. f. mik. Anat. 1866. 
Vol. II, pp. 175-286. 

Schultze, M., Ueber Stäbchen und Zapfen der Retina. Arch. f. mik. Anat. 1867. 
Vol. III, p. 215. 

Schultze, M., Bemerkungen zu dem Aufsatze des Dr. W. Steinlin. Arch. f. mik. 
Anat. 1868. Vol. IV, pp. 10-21. 

Schultze, M., Die Retina. Stricker’s Handbuch der Gewebelehre. 1871. 

Schultze, M., Ueber die Nervenendigung in der Netzhaut des Auges bei Menschen 
und bei Thieren. Arch. f. mik. Anat. 1869. Vol. V, p. 380. 

Schwalbe, Lehrbuch der Anatomie der Sinnesorgane. Erlangen, 1885, p. 392, ete. 

Steinlin, W., Zur Anatomie und Physiologie der Retina. Arch. f. mik. Anat. 1868. 
Vol. IV, p. 10. 


THE SKIN AND THE SENSE-ORGANS. 


I. THE SKIN AND ITS APPENDAGES. 


Tue general characters and the colouring of the skin have already 
been described (pp. 4 to 7). The skin consists of the cv/is vera or 
corium, and the cuticle or epidermis, and Fig. 228. 
is possessed of numerous glands. 


a. The epidermis (Figs. 228, 230) con- 
sists of several layers of epithelial cells, 
those of the deepest layer bemg more or 
less columnar in form, those of the middle 
layer shorter and polygonal, while those of 
the superficial layer are flattened, very 


transparent, and horny. Vertical section through the epi- 
= or an dermis from the head of Rana 
All the surfaces of these cells are serrated, na : atter F. B, Schultze. 
the serrations being, however, with diffi-  Magnifed 600 times. 
A Horny layer. 
culty seen on the free surface of the super- B Middle layer, 
ficial cells (Leydig). Each cell has a C Deep layer. 


ae SS = D Isolated mucous-cells. 
distinct nucleus ; in the deeper cells the 


nucleus is oval, broad, and rounded, in the superficial cells flattened 
and thin. 

The surface of the epidermis (Fig. 230) forms à very beautiful 
mosaic of flat cells, chiefly hexagonal in form, with pale, cen- 
tral, oval nuclei. Here and there two adjacent cells appear to 
enclose a semilunar space (Fig. 228 D); these spaces are occupied 
by peculiar cells (goblet-cells, E. Schultze; mucous cells, Leydig), 
which do not belong to the superficial cells but the layer of cells 
immediately beneath the horny layer (Schultze, Pfitzner). The 
cells are rounded or flask-shaped, and closely resemble the epithelial 
goblet-cells or chalice-cells. According to Rudneff they open on 
the free surface by stomata; this is, however, denied by Schultze 
and others. 


368 THE SKIN AND THE SENSE-ORGANS. 


According to Pfitzner these cells secrete a substance, which has 


Fig. 229. 


Vertical section through the skin of the back ; after Wiedersheim. 


Co Superficial layer of cutis. Ep Epidermis. 

Col Middle layer of cutis. H Horny layer of epidermis. 
Co2 Deep layer of cutis. fe Pigment-cells. 

D Cutaneous glands, W  Papillae. 


D1 Duets of cutaneous glands, 


an important function in connection with the process of casting the 
skin, which consists in the separation of the upper layer from that 


Fig. 230. Fig. 231. 


Surface view of epidermis of Rana temporaria ; Nerve terminations in the branched pigment-cells 


after Eberth. of the cutis; after Ehrmann, Hartnack, Obj. 
A Epidermal cell. 8, Oe "3: 
B Stoma-cell. I. Pigment ceasing abruptly at junction of 
C Attached cuticle from duct of gland, nerve. 
D Protoplasm and nucleus of stoma-cell. II, Pigment gradually ceasing along the nerve. 


below brings about a complete shedding of the skin (Wiedersheim). 


THE SKIN AND ITS APPENDAGES. 369 


[The horny layer is, for the most part, very thin, as it consists of 
one or two layers of flattened cells only (Schultze), but in some 
situations, as on the back and especially on the under surface of the 
toes, it is much thickened, and is then rough. 

Deeply pigmented, branched cells, capable of contractile move- 
ments, are also found, somewhat sparsely distributed, in the epi- 


dermis (Leydig, H. Müller, Schultze). | 


b. The cutis (Fig. 229, Co, Co’, Co”). The epidermis is generally 
attached to the corium by means of a continuous layer of branched 
cells, which is deeply stained when the animals are fed with 
madder (Katschenko). Many of these cells are pigmented. This 
layer is seldom flat, but is raised into papillae and folds, which are 
repeated by the superimposed epidermis. In addition to this layer 
the corrum has, except in the webs and supplemental toes, three 
distinct layers of connective-tissue, together with much unstriped 


muscle-fibre (Eberth). 


The superficial layer (Fig. 229 Co) is a loosely-meshed, much 
pigmented, vascular layer; it forms a loose support for the nu- 
merous glands, and is traversed by numerous nerves. 


The middle layer (Co!) forms the groundwork of the cutis; it 
is much firmer and more compact than the superficial layer ; in 
section it appears as a broad band, bounded superficially by a sharp 
line. It is chiefly composed of closely packed connective-tissue 
fibres, which have, for the main part, a horizontal or wavy course ; 
at certain points, however, vertical fibres are seen passing towards 
the surface and hiding the sharp contour (between Co and Col). At 
such points the two sets of fibres form a sort of basket-work 
arrangement. 


The deepest layer (Fig. 229 Co?) is composed of very delicate, 
white and yellow elastic fibres, and vessels and nerves ; it attaches 
the whole integument to the underlying organs. By the looseness 
of its structure it forms an important lymph-space. 


[The muscle-fibre of the cutis is very unevenly distributed. It is 
found somewhat freely in the region of the back, the dorsal surface 
of the head, and the neck ; less freely on the dorsal surfaces of the | 
extremities, very sparsely on the abdomen, breast, and ventral sur- 
faces of the extremities; in the feet it appears to be absent 
(Eberth). 

The pigment of theskin. As already mentioned pigmented cells 

Bb 


ou THE SKIN AND THE SENSE-ORGANS, 


occur in the epidermis, but by far the greater quantity of the cuta- 
neous pigment is found in the cutis, and more especially in the 
loose layer of branched cells, which form the boundary between 
epidermis and true cutis. These cells, known as chromatophore- 
cells, have been carefully investigated by Harless. They play an 
extremely important part im bringing about the well-known 
changes in the colouring of the skin. Bimmerman has proved 
that these cells are influenced by stimulation of the nerves 
supplying the region m which they occur. Ehrmann has been 
able to trace a direct connection between the nerve-fibres and 
the pigment-cells (Fig. 231 I, II). In such cases the pigment was 
sometimes sharply marked off, at others was gradually lost along 
the nerve. ] 


ce. The papillae and ridges of the skin are classified by Leydig 
as follows: (1) Small ridges, (2) larger ridges, (3) papillae with 
touch-bodies, (4) papillae without touch-bodies, (5) papillae with the 
ducts of glands, (6) capillaries in the form of papillae, (7) small 
elevations, including the lateral organs. 

[AIT these structures are derived from the cutis, the epithelium 
above simply repeating the elevation, and being itself either not 
increased in thickness or only to a slight degree. (For further 
description of some of these papillae, see Organs of Tactile Sensation, 
p- 380.) 

Peculiar wart-like papillae are found on the articulations of the 
first phalanges with the metatarsus, on the same articulations and 
on the articulations between the first and second phalanges of the 
third and fifth toes, and on the articulations between the first, 
second, and third phalanges of the fourth toe. These papillae are 
connected with the long flexor tendons by fine tendinous bands 


(Klein). 


Temporary papillae are developed in the females of Rana temporaria during the 
breeding season ; according to O. Huber (/. c.), who has described them, their distri- 
bution and structure is as follows :— 

During the breeding season the skin of the sides of the trunk of female specimens 
of Rana temporaria is rough; the small elevations, to which this roughness is due, 
are each about the size of the head of a pin, and have the appearance of small, 
rounded, white or pale rose-coloured, warty growths. The papillae reach their 
greatest development and are most numerous on the sides of the trunk (Fig. 232 I) ; 
they may be traced on to the tympanic membrane, where they are arranged in a ring, 
and in some cases under the eyes to the sides of the snout. 

Anteriorly the papillae are absent from the median portion of the dorsal surface of 
the trunk, but posteriorly, behind a line joining the anterior extremities of the two 
iliac bones, the papillae cover the whole surface. 


THE SKIN AND ITS APPENDAGES. Be al | 


The papillae are large and very numerous around the arms, and pass by gradual, 
transitionary stages into the ordinary papillae of the region. Further they may be 
traced backwards along the anterior or extensor surface of the thigh, the upper surface 


Fig. 232. 


I. Diagram to show the distribution of the temporary papillae in Rana 
temporaria ; after Huber. 3 
II, III. Vertical sections through a temporary papilla ; after Huber. 


of the leg, foot, and fifth toe. Occasionally a few papillae were found on flexor sur- 
faces of the third and fourth metatarsus, and very rarely were any discovered on the 
fore-limbs. They occur in no other batrachian of Germany (Huber). 

Each papilla (Fig. 232 II and III) consists of a hemispherical elevation of the 
cutis, and is covered either by a layer of normal epidermis or in scme very rare cases 
the epidermis was slightly thickened. The papilla consists of a firm connective-tissue 
stroma, and is from o*2-0'4 mm. in height, o'4-0°5 mm. broad (after hardening in 
alcohol). Such glands as exist in the papilla usually open laterally (Fig. 232 IIT), 
and the blood-vessels are numerous. 


Bb2 


VQ 


NN 


AR 


372 THE SKIN AND THE SENSE-ORGANS. 


The epidermis covering the papilla is well supplied with nerve-fibres, derived from 
large ganglion-cells in the papilla (Fig. 232 III). The branched pigment-cells, so 
numerous in the rest of the skin, are absent from the upper parts of the papillae 
(Fig. 232 IT) ; the pigment-cells may cease either abruptly or gradually. 

The rose-colour of the papillae is due to the presence of a golden red pigment. 
After the breeding season the papillae are gradually lost, and the pigment-cells 
wander into the unoccupied parts. 

Huber compares the arrangement of the nerves to that of the ‘ touch-spots’ of 
Merkel. 


d. The glands of the skin are of two kinds, serous and mucous ; 
they have been fully described by Engelmann and Openchowski. 


(1) The serous glands (Kérnerdriisen, Engelmann) are large, 
averaging in diameter o°2-0°4 mm., but others vary in size from 
0°13-0°8 mm. in diameter. They are found chiefly on the dorsum 
of the trunk and arranged in groups, which vary in dimensions 
from 3-20 mm. in length and 2-4 mm. in breadth. They may be 
found in any part between the ear-region and the anus, on the 
dorsal surface of the thigh, especially towards the outer and inner 
borders. They are found very sparsely distributed on the ventral 
surface of the trunk and on other parts of the extremities, though 
as a rule a few are found on the dorsal surface of the feet and near 
the phalanges. They are wanting in the nictitating membrane. 

The glands have a rounded form, with the ducts placed at their 
superficial poles. The glands possess three coats; externally is a 
coat of connective-tissue, the fibres of which are arranged closely 
together, and cross one another at acute angles: these fibres are con- 
tinuous with the connective-tissue of the surrounding cutis. Inside 
this coat is a thick layer of muscle-fibre (0°005-0'015 mm.); the 
muscle-cells are arranged meridionally, with the one pole towards 
the superficial surface of the gland, the other pole at the deep surface 
(Hensche). Many of the fibres, however, extend only one-fourth or 
one-third of this distance. 

The innermost coat is a simple layer of epithelial cells, which 
rests directly on the muscle-layer ; no basement-membrane or space 
of any kind having been discovered between the two layers. When 
examined in the recent state these cells are conical or cylindrical in 
shape, and have the appearance of goblet-cells: they possess a 
delicate but distinct cell-wall, but are open towards the lumen of the 
gland. One or sometimes two rounded nuclei are found towards 
the base of the gland, and surrounded by a small amount of gran- 
ular protoplasm ; the rest of the cell is occupied by a mass of small, 
rounded, highly refractive granules of about 0°002—0°01 mm. in 


THE SKIN AND ITS APPENDAGES. one 


diameter. These granules are also to be found in the protoplasm of 
the cell; they contain a substance capable of swelling freely, and 
present many points of resemblance to the granules found in the 
cells of the oviducts. 


These glands represent the poison-glands or lateral glands of toads, and the ear- 
glands or parotids of Caecilia (Leydig). According to Leroux}, Gratiolet and Cloéz?, 
the reaction of these glands in toads varies; according to du Bois-Reymond* the 
reaction is, in frogs, acid; Engelmann‘ found the reaction of these glands, in frogs, 
to be neutral, frequently, however, with a tendency to either acidity or alkalinity. 

These glands correspond with the ‘large glands’ of Hensche, the ‘ contractile 
glands’ of Stieda, the ‘large, dark glands’ of Eberth, and the ‘large contractile 
glands’ of Leydig’s earlier publications. 


(2) The mucous glands are, as a rule, smaller, more numerous, 
and more evenly distributed than the serous glands, Usually they 
lie in such close proximity as almost to touch one another ; according 
to Engelmann an average number of sixty is found in one square 
millimeter ; on the abdomen 62-68 ; flexor surfaces of the posterior 
extremities in some places 76, but in others only 30—40 ; on the webs 
only 2-6 to the square millimeter, On the nictitatmg membrane 
they are arranged in two or three parallel rows, are large, and closely 
applied to each other. They are wanting on the deeper surface of 
the nictitating membrane. 

The glands are generally rounded in form and havea short neck 
(Fig. 229). Glands in the recent condition, and not fully con- 
tracted, have a diameter of 0‘06-0°21 mm., the majority measure 
o°12—0°16 mm. in diameter. The upper pole of the gland is usually 
placed directly under the boundary between epidermis and cutis, 
and, as a rule, about 0‘06-o°1 mm. beneath the superficial surface 
of the skin. The duct usually passes directly to the surface, in a 
straight line. 

The structure of the glands corresponds, in general, with that of 
the serous glands. Externally is a coat of connective-tissue, which 
is, however, more firmly attache | to the muscular coat than in the 
case of the serous glands, and may easily be mistaken for a struc- 
tureless basement-membrane ° (Eberth). The muscular coat is very 
thin, and consists of 16-20 flat, spindle-shaped fibres; extending 
from the upper to the lower pole as in the serous glands. Ata 


! Journal de Médicine, Vol. XI, p. 75. 

* Comptes rendus, 1851, Vol. XXXII, p. 582. 

* Untersuchungen tiber thier. Electricität, 1830, Vol. I, p. 17. 
* Arch. f. d. ges. Physiol., 1852, Vol. V, p. 505. 

* Openchowski (/. c.) describes a basement-membrane. 


374 THE SKIN AND THE SENSE-ORGANS. 


short distance (0‘015-0‘022 mm.) from the upper or superficial 
pole each fibre has an ellipsoid thickening, composed of granular 
protoplasm, and containing a clear oval nucleus. 

The inner coat is composed of a single layer of epithelium, placed 
directly on the muscular coat. The epithelium has a thickness of 
about o‘o1-0‘02 mm.; it is, however, usually thicker towards the 
base than towards the duct. The boundaries between the cells are 
very indistinct, and so give the epithelium the appearance of a con- 
tinuous layer of protoplasm. The glandular epithelium is not 
directly continuous with the epithelium of the duct. 

The shape of the cells depends upon their physiological condition. 
Ina state of semi-contraction of the gland, the cells are cubical, and 
their free borders pushed into the lumen in a slight convexity ; 
when the gland is fully distended the cells are two or three times as 
broad as deep ; in a fully contracted gland the cells are conieal or 
cylindrical. In the first-mentioned condition their diameter varies 
from 0°006-0°018 mm. The larger glands are estimated to possess 
about 150 cells, the smaller only thirty to forty (Engelmann). 

The cells appear to have no cell-wall, certainly they possess none 
on their free surfaces. Their protoplasm distends very freely on 
the addition of water. Asa rule some cells are much more gran- 
ular than others of the same gland ; each cell has a rounded oval, 
clear nucleus, and vacuoles are frequently met with. 

The lumen of the gland contains a colourless, transparent, watery 
fluid, which contains mucous material. 

The ducts of the glands are thick-walled cylinders, cireular in 
section. Their diameter varies from 0‘02-0:05 mm., their length is 
equal to the depth of the superimposed epidermis. The wall of the 
duct is lined with two or three concentric layers of highly refrac- 
tive, nucleated cells. The cells are arranged parallel to the length 
of the duct: im transverse section they are sickle-shaped or semi- 
lunar. In the upper third or fourth of the duct the inner wall is 
lined with a cuticle, very resistent to the action of acids or alkalies : 
it is thrown off with the skin in the process of casting. In the horny 
layer of the epidermis this cuticle is partially closed by a stoma- 
cell (Eberth), (Fig. 230), which possesses a tri-radiate opening. 

The glands correspond with the ‘ non-contractile glands’ of Hensche, the ‘dark 
and bright glands’ of Stieda, the ‘ glandule mezzane, piccole e piccolissime (ad epitelio 


pavimentoso)’ of Ciaccio, and the ‘small, dark, and medium-sized, bright glands’ of 
Eberth. 


e. The peculiarities of the skin of the supplemental toe and 


THE SKIN AND ITS APPENDAGES. oie 


webs. The supplemental toe presents, in the male, a rounded, oval 
swelling (Fig. 234 I, D), with the end of the digit projecting from 
the distal end. 

Normally this swelling is usually of a 
grey colour; during the breeding season, 
however, the swelling enlarges, and be- 
comes of a black or deep brown colour 
(Leydig). 

The epidermis covering this swelling 
(Fig. 233) is much thickened and produced 
into projecting papillae. The cutis also Mic ee a te 
shows a marked thickening and an increase _ epidermis of the supple- 
in vascularity ; the glands are of the kind ee Oe eee 
described as mucous glands (Engelmann).  Masnified 400 times. 
They present, however, an immense increase in size, and at the 
same time are so closely applied to one another as to form 


Fig. 234. 


fr gM 
PSK 
ae 
CEE 


Co 
Fore-foot of a male frog. Vertical section through the swelling on the supplemental toe 
D Glandular swelling on the supplemental of a male frog. 
toe. 
3 B Blood-vessels. 
Ww Warty papillae on the inter-phalangeal Co Rete 4 
Joints. D Glands. 
Ep Epidermis. 
M Muscles, 


P Pigment-cells. > 


the main part of the enlargement (see also Organs of Tactile 
Sensation). 
In the webs the various layers of the corium are more or less 


376 THE SKIN AND THE SENSE-ORGANS. 


fused together, and cannot be distinguished from each other; the 
glands are, as a rule, smaller than on the general surface of the 
skin, 

f. The blood-vessels and lymphatics of the skin. 

(1) The blocd-vessels of the skin are arranged in two networks ; 
the one is situated immediately beneath the epidermis, and consists 
of fine capillaries, forming a fine-meshed network, which enclose the 
ducts of the glands. The meshes vary considerably in size and 


The blood-vessels and lymphatics of the skin ; after Langer. Arteries striped, lymphatics shaded. 


I. Vertical section through skin of thigh. 
IL Horizontal view of arteries and lymphatics of the skin. 
III. Peculiar tortuous arteries of the lamina inguinalis. 
IV, Arteries and lymphatics of the web, 


shape (Hyrtl and Langer). The second network of vessels is situ- 
ated under the cutis; the vessels forming it are small, and the 
meshes formed are large. From this network vertical branches 
pass to form the superficial network ; these branches usually course 
along the strands of vertical fibres already described, and break up 
to form capillaries only when they reach the deeper surface of the 
epidermis (Langer), (Fig. 235 I). 

In some situations, however, the vertical branches divide earlier ; 
this is especially the case in parts where the glands are very closely 
packed, as in the nictitating membrane, the upper lip, and the 


THE ORGANS OF TACTILE SENSATION. 377 


swelling of the supplemental toe (in the male). In these parts the 
division takes place at the deeper surface of the glands (Langer). 

A peculiar arrangement of the cutaneous blood-vessels is found in 
the lamina inguinalis, where a chain of reddish points can be made 
out with the naked eye; examined more carefully (Fig. 235 III) 
each reddish point is found to be a complex loop of capillaries. 
They extend from the skin to the hinder lymph-hearts, where they 
form a close network which partially invests the lymph-hearts 
(Langer). 

(2) The lymphatics of the skin (see also p. 252), like the 
arteries, reach the deeper surface of the epidermis by coursing along 
the bands of vertical fibres; they then form a network of capil- 
laries with rounded meshes (Fig. 235 I, II, IV ), and lying imme- 
diately under the epidermis, and a network which surrounds the 
various glands. The lymphatic-capillaries are as a rule larger than 
the blood-capillaries. The lymphatic network lies beneath the 
blood network, and the vessels of the two systems branch indepen- 
dently (Langer). 

In those parts where the glands are placed closely together this 
arrangement is modified, and corresponds with the modifications 
found in the blood-capillaries in these regions. The vertical branches 
divide so as to form a network below the glands, and from this ver- 
tical branches pass in the same direction between the glands to form a 
secondary network on the superficial surface of the glands (Langer). 

g. The nerves of the skin. The cutis is very richly supplied 
with both medullated and non-medullated nerves. In the subcuta- 
neous tissue the nerves destined for the skin branch freely to form 
numerous fine twigs, which, without actually inosculating, form a 
fine meshwork. From the larger trunks numerous vertical branches 
pass vertically to form a secondary network, from which both coarse 
and very fine twigs pass to encircle the glands. The fine fibres which 
supply the glands are non-medullated and possess oval nuclei ; their 
diameter varies from o‘001-0°002 mm. - The number of nerve-fibres 
is not much smaller than that of the muscle-fibres (Engelmann). 
(See also Organs of Tactile Sensation.) ] 


IT. THE ORGANS OF TACTILE SENSATION... 


The organs of tactile sensation are the nerve-plexus of the epi- 
dermis, the touch-spots of Merkel, the lateral sense-organs, and the 
touch-corpuscles of the tendons. 


378 THE SKIN AND THE SENSE-ORGANS. 


a. [The nerve-plexus of the epithelium is very incomplete as 
compared with the plexus found in the epithelium of the cornea ; 
here and there a few non-medullated fibres have been traced a short 
distance between the epithelial cells. No such mode of nerve- 
terminations in the epithelium as is described by Eberth and Macul- 
lum in the tadpole can be found in the adult. | 


b. The touch-spots. What knowledge we possess of these 
organs is due to the labours of Leydig, Ciaccio, Eberth, and more 
particularly those of Merkel. 

At the base of each papilla, which contains such a touch-organ, 
is found a number of colourless, flattened cells, arranged either in a 
single layer, or heaped up and connected with very fine nerve-fibres. 


Fig. 236. 
1s IT. 


I. Lateral sense-organ of tadpole of frog. Half-schematic. 


c Central zone (nerve-epithelium), 

Mi Membrana limitans. 

Pp Peripheral zone (sustentacular cells). 
R  Hyaline tube. 


II. Touch-corpuscle from the sheath of a digital tendon of the frog ; 
after Léwe. Schieck, Oc. O., Obj. 9. 


The flat surface of the cells is parallel to the surface of the body, 
and they do not form a separate or circumscribed body, they are 
therefore better spoken of as touch-spots than as true touch-bodies 
(Merkel). The larger organs are found in the papillae, but smaller 
ones may be found on any part of the skin. 

These organs are best seen in the prominence or swelling upon the 
supplemental toe during the breeding season ; they are numerous 
on the dorsal surface of the trunk, but occur most frequently on 
the under surface of the hinder feet (Planta pedis). After the 


THE ORGANS OF TACTILE SENSATION. 379 


breeding season the organs of the thumb undergo a retrogressive 
change, which results in a network of spindle-shaped and branched 
cells with fibres (Wiedersheim). 


e. The lateral sense-organs attain their highest development in 
the tadpole ; in the adult the organs have undergone a retrogressive 
change, the result of which is that the organs are diminished in 
size; the whole organ sinks by the formation of a tube, which is 
then closed by a mucous secretion, consequently the organ is 
functionless : with this loss in function and change in position of 
the organs a corresponding diminution of the ramus lateralis nervi 
vagi occurs (Merkel). 

Each lateral organ (Fig. 236 1) consists of a shghtly elevated papilla, 
with the centre depressed, and in each may be distinguished a central 
and a peripheral zone (c,p). The central zone consists of a group of 
pear-shaped cells, with the narrower ends directed towards the free 
surface ; each is connected below with a nerve-fibril, while above it 
bears a short, stiff cilium. The cilia are enclosed in a delicate 
hyaline tube (2), which is open superficially, closed by the papilla 
below ; consequently the cilia are in direct contact with the sur- 
rounding medium. The peripheral zone is a layer of pale, flattened, 
cylindrical cells (py); they possess, at their upper borders, a perforated 
membrana limitans (M7), through which the cilia pass. These 
cells serve as a support to the central cells, and are themselves 
surrounded by ordinary epithelial cells. 

The distribution and arrangement of the lateral organs is alike in fish and larval 
amphibia. They are most numerous on the head, where they surround the eye, and 
are continued forwards to the snout and on to the lower jaw. All these organs on 
the head are in connection with the trigeminal nerve. A line of these organs passes 
from the hinder part of the circumference of the eye along the gill-cover to the neck, 
where the lines of opposite sides are usually, though not constantly, joined by a 
transverse line of the same organs; thence the lines are continued along the trunk to 
the tip of the tail. In fish there exists, as a rule, only one pair of such longitudinal 
lines (Linea lateralis); in anura-larvae, proteus, and in all salamanders there are 
three pairs: of these one pair lies near the vertebral column, the second at the 


junction of the flank with the abdomen, and the third corresponds to the lateral line 
in fish (Malbranc). 


At an early developmental period each metamere possesses one pair of such lateral 


organs ; in later life, however, this simple arrangement is lost, and each segment 
usually possesses a group of organs. 

The organs of the trunk and tail are supplied by branches of the Ramus lateralis 
nervi vagi. Both in fish and amphibia a reparative process, by means of fission, 
occurs ; as a consequence the organs are found in various stages of development. 


d. [The touch-corpuscles of Golgi and Lüwe (Fig. 236 II) are 
found on the joints of the digits. They are surrounded by con- 


380 THE SKIN AND THE SENSE-ORGANS. 


nective-tissue and are spindle-shaped ; the two ends of the spindle 
are glassy in appearance, the middle portion is fibrous. In the 
thickest part of the corpuscle is a zone of nuclear bodies. 

They are regarded as touch-bodies (Golgiand Lüwe). Golgi (/. ce.) 
describes two kinds of touch-organs in connection with muscle and 
tendon ; one class correspond with those just described, he names 
them ‘nervous muscle-tendon organs.’ The second class he com- 
pares with the touch-bodies found in the conjunctiva. | 


Il. THE ORGANS OF TASTE. 


The organs of taste are not confined to the surface of the tongue, 
but are also found on the mucous membrane of the roof of the 
mouth, especially in the neighbourhood of the vomerine teeth ; on 
both roof and floor of the mouth these organs can be traced to the 
commencement of the oesophagus. 

[The mucous membrane of the tongue possesses two kinds of 
papillae and numerous glands. 


a. The filiform papillae are the more numerous ; they are conical 
or thread-like in form, and consist of connective-tissue, with a few 
striated muscle-fibres ; they include blood-capillaries, but no nerves 
have been traced into them (Leydig). They are covered with 
ciliated epithelium and goblet-cells. 


b. The fungiform papillae are much larger, and are paler than 
the filiform papillae. The free ends of these papillae are broader 
than the bases, and when the epithelium is removed the free ends 
present a concavity. From the base to the border of the free surface 
each papilla is covered with the usual oval, ciliated epithelium, 
but at this border an abrupt transition takes place. The 
epithelium covering the end of the papillae is of three -kinds : 
goblet-cells, cylindrical cells, and forked cells; the three forms of 
cells are quite characteristic, and no intermediate transitionary forms 
are met with. 

(1) The goblet-cells (Fig. 237 I) are arranged vertically to the 
free surface of the papilla; they are from o‘020-0‘024 mm. in 
length, and from o‘o1-0‘o2 mm. in diameter. In the lower third 
of the cell is found a nucleus of about o‘008 mm. in diameter, and 
this encloses a nucleolus of about o‘oo1 mm. in diameter. Close 
underneath the nucleus the cell is contracted to form an irregular 
process or foot. The contents of the cells are a very finely granular, 


THE ORGANS OF TASTE. 381 


transparent protoplasm. These cells form the outermost part of the 
epithelium, covering the end of the papilla; all the cells belonging 
to the same papilla are of the same size. In consequence of the 
mutual pressure which they exert on each other they present, in 
transverse section, six-sided outlines (Fig. 237, 2). The nuclei of 
adjacent cells are placed at almost exactly the same level. By the 


I, Various parts from the fungiform papillae ; * goblet-and forked cells ; only cylindrical 
after Engelmann, cells remaining. Magnified 400 times. 

1. Nerves of a fungiform papilla. Magnified 450 5 Goblet-cell, with swollen contents. Magni- 
times. fied 450 times. 

2. Surface view of the epithelium, after five 6-13. Various forms of isolated forked cells. 
minutes’ action of iodized serum. Magnified Magnified 450 times. 
600 times. II. Sections of two glands of the tongue ; 

3. Goblet-cell with adjacent forked cell. Magni- < after Biederman, 
fied 450 times. 1. Resting-gland. 

4. Portion of the papilla, after removal of the 2. Gland after stimulation. 


action of reagents on these cells very remarkable forms are obtained, 
in consequence of the protoplasm swelling and being forced up- 
wards (Fig. 237, 5). 

(2) The cylindrical cells (Fig. 237 I) have rounded free extre- 
mities, which reach to the general surface of the epithelium ; the 
remainder of the cell is cylindrical except towards its lower ex- 


382 THE SKIN AND THE SENSE-ORGANS. 

tremity, where it is slightly dilated and encloses an oval nucleus : 
the protoplasm of the cells is very finely granular. These cells rest 
on the connective-tissue of the papilla, and are in close juxtaposition, 
so that several hundreds of them are found on one papilla. 

The spaces between the upper parts of the cylindrical cells are 
occupied by the goblet-cells and by the forked cells. 

(3) The third form of cell found on the fungiform papillae are 
named forked cells (Fig. 237 I) by Engelmann. The body of the 
cells has an ellipsoidal form, is from 0‘006-0:co8 mm. in its longer 
diameter, and 07003-0004 mm. in the shorter diameter. Processes 
arise from both poles. The peripheral processes arise by a short 
common stem, which then divides into two or rarely three branches ; 
the whole process is from 0°004—0°008 mm. in length, and is always 
just sufficiently long to reach the general surface of the epithelium : 
when the peripheral process is long the central is usually shorter, 
and vice versd. 

The central processes arise by a stem from 0o‘001-0:002 mm. in 
thickness, which usually divides dichotomously. The length of this 
process may be as much as 0°025 mm. or almost nil. 

The forked cells are about twice as numerous as the goblet-cells, 
they occupy the spaces between the cylindrical cells and the goblet- 
cells. The branched central processes form a network on the 
connective-tissue of the papilla, which is, at this point, perforated 
by a rich plexus of fine non-medullated nerve-fibrils. It 1s not de- 
cided whether the processes of various cells inosculate. Engelmann 
regards these forked cells as the taste-cells and as the sensory 
nerve-endings. 

The bodies of the fungiform papillae contam blood-vessels and 
nerves, the latter enter as medullated nerves, but lose the medulla 
somewhat abruptly towards the upper end of the papilla, where they 
form a sort of nerve-cushion (Nervenkissen, Engelmann). | 

Taste-organs are alsô found on the roof and other parts of the 
mouth, and present many points of resemblance to the lateral sense- 
organs. Like them they present a peripheral zone and a central 
zone; the cells of the latter, however, are not longer than the 
peripheral cells, and possess no cilia (J. van der Hoeven, Merkel). 


THE NOSE. 383 


IV. THE NOSE. 


The anterior nares or nostrils are two small openings, placed di- 
rectly in front of the anterior angle of the eye ; the distance between 
the eye and the corresponding nostril being, in the case of adult 
animals, about five or six millimeters. The anterior nares are sur- 
rounded by rims, which are contracted below, and so form very short, 
tentacular-like prominences. 

The posterior nares (choanae) are about four millimeters from 
the anterior nares, consequently the long axis of the nose is, approxi- 
mately, of this length. (For the external muscles of the nose, 
see p. 59.) 

The boundaries of the nasal cavities are as follows :—the roof of 
each cavity is formed by the dorsal plate of the sphenethmoid, the 
nasal bone, and the premaxillary bone; the floor is formed by the 
vomer and the palatine bone, the inner wall by the vertical septum 
of the sphenethmoid, the outer wall by the premaxillary and max- 
illary bones, the anterior wall by the premaxillary bone, and the 
posterior wall by the sphenethmoid. The cartilaginous portion of 
the nasal skeleton (see also p. 27) projects into the general cavity 
and subdivides it into various sinuses, which have been the subject 
of careful investigation by Born and Wiedershem. 

a. The nasal cavities are best examined by means of serial trans- 
verse sections ; in a section through the anterior nares (Figs. 238, 
239) there will be seen three smuses on either side :— 

(1) The superior sinus (07) is large, rounded, and placed against 
the cartilaginous septum ; the sinus is lined with olfactory epithe- 
lium. Posteriorly the sinus extends beyond the posterior nares, and 
is bounded by the anterior surface of the sphenethmoid. In front it 
ends in a rounded concavity, likewise lined with olfactory mucous 
membrane. Opposite the anterior nares the cavity is partially sub- 
divided, by a longitudinal process on the floor, into two cavities ; 
the anterior nares open into the external chambers, and therefore 
not directly into the main cavity of the superior sinus. The supe- 
rior sinus communicates with the inferior sinus by a narrow, almost 
vertical, slit. 

(2) The inferior sinus (vz) is narrow and flattened from above 
downwards ; it is placed against the maxillary bone, and represents 
the maxillary sinus of the frog. Externally it possesses a de- 
seending: arm. 


The inferior sinus is continued backwards and opens on its 


384 THE SKIN AND THE SENSE-ORGANS, 


) 


inner side into the posterior nares, or rather into the mouth. The 
descending arm extends only a short distance forwards, to terminate 
near the point where the superior and inferior sinuses communicate 
by only a narrow opening. This sinus is on the whole broader m 
front than behind, and has a general direction from without, in- 
wards and forwards underneath the superior sinus. 


Fig. 238. 


Frontal sections through the nose of two 
tadpoles ; after G. Born. 


A Anterior naris. 

b Cartilaginous floor. 
C Cutis. 

d Cartilaginous roof. 
Ep Epidermis. 

gi Intermaxillary gland. 


gni Lower nasal gland. 
gns Upper nasal gland. 


K Maxillary sinus. 
l Concha narium (os lachrymale). 
m Maxillary bone. 


MS Oral mucous membrane. 
ok Cartilage. 

on Upper blind sae. 

R Pharyngeal gland. 


S Nasal septum. 

se Septum between the upper and lower 
nasal cavity. 

sn External blind sac, 

db Trabeculae. 


Th Lachrymal duct. 
un Lower blind sac. 


(3) The lateral sinus (sz) is situated in the partition between the 
superior and inferior sinuses, or rather between the external chamber 
of the upper sinus and the inferior sinus. The lateral sinus is tri- 
angular in form, being narrow in front and broad behind ; at its 


THE NOSE. 385 


inner posterior angle it opens on the free border of the horizontal 
partition between the superior and inferior sinuses ; this opening is, 
however, continued along its roof, so that the lateral sinus opens 
also into the superior sinus. 


b. The nasal cartilages. The two nasal cavities are completely 
separated by the cartilaginous septum (Figs. 238 and 239 8), and 
are for the most part lined by cartilage. The anterior end is 
formed of concave cartilages, while the posterior, bemg situated in 
the sphenethmoid, is usually more or less ossified in the adult. The 
posterior wall has two openings: a larger near the septum for the 
olfactory nerve, and a smaller, more externally, for the nasal branch 
of the trigeminal nerve. 

The anterior wall is more complex than the posterior, being 
thicker in the middle than at the sides, and possessing three blind 
sacs for the three sinuses. From the anterior wall two processes 
project backwards between the sacs and enclose them more or less 
completely. 

Of the three sacs or cavities only the lower is completely sur- 
rounded by cartilage. The upper sac is in part bounded by a shell- 
shaped, concave cartilage (Concha narium, of various authors; Os 
lachrymale, Born), which covers it anteriorly and externally, and is 
attached by a small base to the roof of the lower sac (Fig. 230, /), 
its upper border bounding the anterior naris (Fig. 15). The upper 
and external parts of the upper sac have no cartilage. The carti- 
lages of the outer wall of the lower, blind sac extend backwards to 
the point where the maxillary smus commences to descend: the 
roof, however, is prolonged further backwards by two small cartila- 
ginous processes ; the inner is short, the outer forms the roof of the 
descending arm of the sinus, and joins a cartilaginous process, which 
commences at the anterior portion of the roof of the nasal cavity, 
passes backwards and downwards to a broad plate, and forms an in- 
complete outer wall to the nasal cavity. There are also three carti- 
laginous processes—a. One arising from the outer side of the floor 
at the level of its junction with the anterior wall; it is a flattened 
process and passes outwards, and bifurcates at its end to meet the 
premaxillary and maxillary bones (this is the Oberkieferfortsatz of 
Ecker), (p. 28, Fig. 14 %”)). 8. A delicate process on either side, 
described by Wiedersheim (see p. 280). y. The third pair of pro- 
cesses are fully described for the first time by Born ; each arises at 
the lower border of the corresponding Concha narium, passes forwards 
and downwards under the ascending process of the premaxillary to 

ce 


386 THE SKIN AND THE SENSE-ORGANS. 


the point where process 6 is attached to this bone. The processes 
are flat and approach one another obliquely ; in older animals they 
are united at the point of contact. 

At the junction of the anterior wall, the septum, and the floor is 
a large aperture in the cartilaginous capsule, through which passes 
the chief nasal branch of the trigeminus, which supplies numerous 
branches to the intermaxillary gland. 


e. The glands of the nasal region are Bowman’s glands, the in- 
termaxillary glands (Wiedersheim), the lower nasal gland (Born), 
the upper nasal gland (Born), the pharyngeal gland (Born), and the 
lachrymal duct. 

Fig. 240. (1) The intermaxillary gland 
(see p. 280). 

(2) The lower nasal gland is 
placed along the septum and ex- 
tends as far back as the posterior 
nares, opening by its ducts (Figs. 
238 and 239 gui) into the inferior 
blind sac of the nasal cavity. In 
histological structure it corresponds 
with the intermaxillary glands, 
except that the glandular tubes 
are somewhat smaller, and the 
glandular epithelium stains some- 
what less easily with carmine 
(Born). 

(3) The upper nasal gland occu- 
pies the space between the Concha 
narium (Os lachrymale, Born) and the 

vy neighbouring cartilages, it also sur- 
I. A. Bowman’s glands in situ from Rana : : 
temporaria : after C. K. Hoffmann, Younds the anterior naris and the 


ae opening of the lachrymal canal 
B. Section of Bowman’s gland ; after 5 
C. K. Hoffmann, Magnified 30 (Figs. 238 and 239 gus). The 


EE numerous ducts open on the mucous 
II. Vessels of nasal mucous membrane of 5 ë 
Rana esculenta ; after Langer. Blood. Membrane covering the oblique car- 
vessels striped, lymphatics shaded, tilage (above des eribe d, as pa ssin g 
from in front, downwards and backwards, and forming an incom- 
plete outer wall of the cavity), and its hinder prolongation. 
(4) The pharyngeal gland is placed transversely behind the pos- 


terior nares, and surrounds the vomerine teeth. A portion of the 


i —-9da.2 Vi mtg, 


+ rer, 


THE NOSE. 387 
ducts open into the posterior nares, the remainder on the mucous 
membrane of the pharyngo-oral cavity at two symmetrically placed 
points (Fig. 238 ZX). 

(5) The lachrymal duct (see p. 428) opens into the nasal cavity 
at the point where the lateral smus opens into the external chamber 
of the superior nasal sinus. 

(6) [The glands of Bowman (Fig. 240 I) are freely distri- 
buted in the nasal mucous membrane. Each gland is usually 
rounded or flask-shaped, and consists of a single layer of large epi- 
thelial cells possessing distinct nuclei and nucleoli. The epithelium 
of the glands possesses no basement membrane (M. Schultze and 
Hoffmann!), but is bounded externally by a layer of nerve-fibres 
and connective-tissue. 

The glands situated more superficially have straight ducts open- 
ing on the surface; those placed more deeply have usually curved 
ducts (Paschutin). | 


d. The mucous membrane of the nasal cavities. That part of 
the superior sinus immediately around the anterior naris is lined 
with stratified epithelium ; the rest of the nasal cavity is limed with 
columnar ciliated epithelium. The epithelial layer rests on a sub- 
epithelial network, and this again on a submucous connective- 
tissue layer possessing numerous vessels and nerves. 

(1) The epithelial layer (Fig. 241) consists of columnar cells, 
which in the olfactory region are of two kinds; in other regions the 
epithelium consists of closely-applied ciliated, thick cells, possessing 
large oval nuclei, and having irregular, branched bases or ‘feet.’ 
The cells are 0‘032-0°048 mm. long ; the nuclei 0‘016-0°018 mm. 
long, and 0:006-0'008 mm. broad. The free borders of the cells 
bear a number of fine cilia. 

In the olfactory region a second set of cells, olfactory cells, are met 
with ; these cells (Fig. 241 IT) possess each an oval body, enclosing 
a large nucleus, and a peripheral and central process. The peripheral 
processes reach to the general surface of the surrounding epithelium 
and there terminate in a number (5-8) of stiff cilia; these cilia are 
sometimes o'og mm. long, they are thicker at their bases than the 
ordinary cilia (Schultze); according to Hoffmann, a second system of 
stiffer and longer cilia is met with; of which each olfactory cell 
possesses as a rule only one. The bodies of the olfactory cells are 
0'009-0'010 mm. long, and 0‘007--0°008 mm. broad; the peripheral 


! Paschutin describes a basement membrane. 
C.Ga2. 


388 THE SKIN AND THE SENSE-ORGANS. 


processes vary considerably in length, according to the position of 
the body (0°03-0'05 mm.). The central processes vary from o‘02- 
o‘o3 mm. in length. The peripheral processes are considerably 
thicker than the central processes. No membrana limitans olfactoria 
has been discovered in the frog. 

(2) The second layer consists of a network of processes belong 
to the bases of the central processes of the superimposed epithelial 
and olfactory cells. Numerous highly refractive nuclei possessing: 
nucleoli are situated in the meshes of this network ; they correspond 

; in all particulars with the nuclei of the 
ne a olfactory cells (M. Schultze). According 
| to Exner the branched processes of the 
epithelial cells and of the olfactory cells 
unite to form a complex plexus. Other 
observers, Paschutin, Cissoff, v. Brunn, 
Schultze, and Hoffmann oppose this 
view, and hold that the central processes 
of the olfactory cells do not unite with 
the processes of the epithelial cells, but 
that they are in direct continuity with 
the fibrils of the olfactory nerve. This 
view is probably correct. 

The submucous layer has a loose con- 
nective-tissue matrix, which encloses the 
glands, nerves, and vessels; according 
to Paschutin two pigment-layers may 
be distinguished: the one, immediately 
under the middle layer of this mucous 
membrane, is continuous and deeply pig- 
mented ; the second is deeper and does 


ae 
Was eso 


Ee se of 
> awed) A er 


A 27 


| Of 

4 ; 
Separations from the olfactory mu- 
cous membrane of Rana temporaria ; 
ME ne etre not form a continuous layer. This layer 


I. Surface view of the olfactory - . 1 
mucous membrane. Magni. 18. extremely rich in blood-vessels and 


55 oO 5 . e 
fied abo times. lymphatics (Langer and Paschutin), 
II. Epithelial and olfactory cells, Fi ee] haan A 
Migeaiied Goo tinea, (Fig. 240 II). The lymphatics are rela- 
Il. ptt cells. Magnified 600 tively very large and are very numerous 
imes. 
(Langer). 


In this layer the central processes of the olfactory cells form 
bundles of fibres, lying parallel with the surface of the mucous mem- 
brane (Paschutin, Cissoff, and Schultze). | 


THE BAR. 389 


NRA FEAR: 


(Re-written by the translator from Das Gehürorgan der Wirbelthiere, 
by G. Retzius, 1881.) 


The organ of hearing is divisible into two parts, the tympanum 
or middle ear, and the labyrinth or internal ear; an external ear is 
absent, unless a very slight depression of the tympanic membrane 
be regarded as such. 


A. The tympanum (Cavum tympant) is a cavity, bounded ex- 
ternally by the tympanic membrane and internally by the capsule 
of the internal ear; it communicates by means of the Eustachian 


tube (tuba Eustachi1) with the pharyngo-oral cavity (Fig. 178). 


a. The tympanic membrane lies immediately underneath the 
skin, but can be separated from that structure; externally it 
possesses a very slight depression, the only Fig. 242. 
trace of an external ear found in the frog. 

The tympanic membrane is of a rounded 
oval form, being a little wider in the trans- 
verse than in the longitudinal diameter; the 
membrane is directed outwards. 

After detaching the skin (Fig. 242 I) the 
membrane is seen to be attached by its cireum- 
ference to a ring of cartilage (Awnulus mem- 
branae tympani; see also p. 26) (at); the ring 
‘is attached anteriorly and above to the squa- 
mosal bone (sq), and in the rest of its circum- 


I 


. The tympanic membrane 
of Rana esculenta; 
natural size. After 


ference to the surrounding: soft parts, 7. ¢. the Retzius. 
. 5 II. The t panum as seen 
M. depressor maxillae (dm), the M. temporalis AS PR the 
(4), and their fasciae. In the middle of the DENT eae) 
: e s natural size. After 
membrane is a small, rounded, white part (co/) Retzius. 
which can be traced backwards and upwards “ es Der 
towards the circumference. col Columella. 


The membrane consists of fibres of con- as ie sake face 
nective-tissue which radiate peripherally from "mag ee 
the central point of attachment of the colu- ' M:temporalis. 
mella; in the peripheral portion unstriated muscular fibres are 
also found (Leydig). 


Internally the tympanic membrane is covered by columnar epi- 


390 THE SKIN AND THE SENSE-ORGANS. 


thelium, a continuation of the mucous membrane lining the tympanic 
cavity. 


b. The tympanic cavity (Fig. 242 I1) is seen, after removing the 
tympanic membrane, as a flattened, funnel-shaped cavity. The 
walls of the cavity are lined with a pigmented mucous membrane, 
under which the cartilaginous ring (annulus membranae tympani) 
extends internally to form the greater part of the wall of the cavity. 
The cavity is an elongated oval slit (Fig. 242 I, c/), with its longer 
axis directed from above and in front, downwards and backwards, 
and leading inwards ; it is bounded above, below, and in front by the 
squamosal, behind by the soft parts ; above in the roof is the cartila- 
ginous part of the co/umella. The inner or deeper portion of the 
tympanic cavity is bounded in front by the squamosal, and by the 
squamous process of the prootici (proc. squamosus prootici) in front 
and above ; internally by the cartilage (primordial-cranium) between 
the prootic and the exoccipital ; behind by the J/. depressor mawillae. 
This part of the cavity is rounded and covered with mucous mem- 
brane, and has in its roof the bony part of the columella, which 
covers the foramen ovale (fenestra ovalis) by its oval, widened end- 
piece. This deeper portion of the cavity communicates by a short, 
wide Eustachian tube with the pharyngo-oral cavity; the tube is 
wide and is of a rounded oval form in section : anteriorly, externally, 
and internally it is bounded by the pterygoids, posteriorly by soft 
parts, in which is embedded the styloid process. 

The tympanic cavity can be examined from without after re- 
moving the tympanic membrane, or from below by means of the 
Eustachian tube. 


ce. The columella auris (Figs. 12, 243) is described by Retzius 
as consisting of three portions, of which the middle is bony, the 
external and internal cartilaginous. Parker divides it into four 
parts (see pp. 25, 26). 

The extrastapedial (Fig. 243 a’, a”) is attached to the middle of 
the tympanic membrane by the oval surface opposite 4’, and is 
attached by the process a’” to the annulus tympanicus ; this process 
of Retzius is the suprastapedial of Parker. 

The mediostapedial (Parker), or middle bony piece of Retzius 
(Figs. 12 a’, 243, 0’), is narrow externally but widens internally 
to articulate with the interstapedial. Just before reaching the 
latter it gives off a process (4’), to which are attached a few fibres of 
striated muscle (7). 


THE EAR. 391 


The interstapedial (Figs. 12 a, 243 ¢) is cartilaginous; it is 
thick with a sharply cut-off, slightly concave end, which is placed 
against the fexestra ovalis. The inner surface of the interstapedial 
is, however, distinctly 
larger than the opening: Vig. 243. 
of the fenestra ovalis, con- 
sequently it does not fit 
in accurately, but is at- 
tached to the border of 
the opening by means of 
connective - tissue ; the 
margins of the fenestra 
ovalis are hollowed (Fig. 
245 II) so as to form a 
Jossa fenestrae ovalis, and 
itis really to the margin The columella; after Retzius. Magnified eight times. 


of this fossa that the A. Seen from above. 
B. Seen from behind. 


connective-tissue capsule de > 
A à - i Extrastapedial (Parker). Outer cartilaginous portion 
of the interstapedial 1s attached to middle of tympanic membrane (Retzius). 
attached a Attachment of extrastapedial to mediostapedial. 
attacned. “’ Suprastapedial(Parker). Portion embedded in mucous 


FRERE PES : membrane (Retzius 

B. The labyrinth omin- ".. Medostapedial (Parker). ~ Bony part (Retzius). 

a ‘ ae © b’* ~ Process of mediostapedial, 

ternal ear is contained ina c Interstapedial (Parker). Inner cartilaginous piece 
(Retzius), : ; 

capsule formed of bone m Insertion of small muscle. are i 


! el 
and cartilage. ~ 


a. The capsule of the labyrinth (Fig. 244) is formed of two 
bones, the prootic and the exoccipital (according to Hasse this 
includes the opisthotic), which are united by cartilage belonging: to 
the primordial-cranium. The fronto-parietal, squamosal, and para- 
sphenoid take only an indirect part in its formation. 

On the whole the anterior half of the capsule is formed by the 
prootic, and the hinder half by the exoccipital; the cavity has its 
long axis directed from within and above, downwards and outward ; 
the cavity is comparatively large and rounded, and contains the 
membranous ear. 

Four surfaces can be distinguished : a supero-external, an interno- 
inferior, an anterior, and a posterior (Retzius). 

(1) The supero-external surface is divided into two parts by a 
strong, transverse, bony ridge, the processus squamosus prootict. 
The upper half is concave, is directed upwards and outwards, and 
is formed by the prootic ; it is separated from the anterior surface 


392 THE SKIN AND THE SENSE-ORGANS. 


by a bony ridge, which marks the position of the anterior semi- 
circular canal. Posteriorly and medianly it is separated from the 
posterior surface by a cartilaginous ridge, running from above, 
downwards and outwards, which marks the position of the posterior 
semicircular canal. The cartilaginous 
hinder root of the processus squamosus 
prootici arises in the cartilaginous ridge 
just mentioned, and runs outwards and 
forwards, covering the external semi- 
circular canal. 
The lower half of the supero-external 
surface (under the processus squamosus) 
is irregularly concave; immediately 
a ae ee a ee “under the proc. syuamosus is a shallow 


Rana esculenta ; after Retzius. En- @yroove in the prootic 3 it is continued 
larged five times, 


BOW gai tae Svein on the exoccipital to the jugular fora- 
av. Aquaeductus vestibuli. men. The remaining: part of this sur- 
cp. Posterior semicireular canal. 


cra. Canalis rami anterioris acustic. face consists of a rounded cartilage, and 
erp. Canalis rami posterioris acustici. 


Fete Cr apres Po is part of the primordial-cranium car- 
fe. Fovea sacculi et cochleae. tilage between the prootic and the 
Jt. Trigeminal foramen, 34.8 = : 

kn, Cartilaginons suture. exoccipital ; posteriorly it has a small 
7. Exoccipital. 5 
M oval aperture, the foramen ovale ( fenestra 
Ps, , Parasphenoid. vestibulare), which with the groove is 


covered by the columel/a. Above the aperture the cartilage narrows 
and is continued to the processus squamosus. 


(2) The posterior surface is directly continuous with the supero- 
external surface, and is formed by the exoccipital. This surface lies 
behind the ridge formed by the posterior semicircular canal, it is 
concave, and has two small apertures, separated by a narrow, bony 
process, and situated near the jugular foramen; these are the 
Joramen rotundum { fr.) and the aquaeductus cochleae (ac.). 

(3) The anterior surface is altogether bony and formed by the 
prootic(pr.); the anterior surface of this part of the wall is continuous 
with the surface of the cranium, and abuts on to the large tri- 
geminal foramen (ff); below it is continuous with the under 
surface of the cranium, below and externally it articulates with the 
pterygoid. | 

(4) The interno-inferior surface is as a whole hollowed in- 
ternally, the upper part being pushed in towards the cranial cavity. 
It is formed by the prootic anteriorly, by the exoccipital posteriorly, 
and is completed by the cartilage lying between these bones. In 


THE HAR. 393 


the middle of the upper part of the cartilage is a small oval opening 
(av.), the ap. aquaeductus vestibuli: about midway between this 
aperture and the jugular foramen is a second opening in the 
cartilage (cra.), the opening of the canalis rami anterioris (vestibu- 
laris) acustici : a little behind and above this is the opening of the 
canalis rami posterioris (cochlearis) acustici, situated in the exocci- 
pital. The cartilage between the prootie and exoccipital in the 
lower half of the interno-inferior surface rests on the parasphenoid. 


b. The position of the soft parts in the capsule. The large 
outer, rounded part of the cavity contams the saccule and cochlea 
(fovea sacculi et cochleae) ( fsc.). Above, the cavity is more irregular, 
and contains the utricle and the sinus utriculi superior. In 
front and externally, imbedded in a deep groove, are the anterior 
and external ampullae (fovea ampullae anterioris et amp. externae) ; 
to these are attached the corresponding semicircular canals. The 
anterior semicircular canal opens above and externally into the canal 
of the sinus utriculi superior ; the posterior passes into a groove for 
the posterior ampulla (fovea ampullae posterioris), and opens above 
and internally into the posterior semicircular canal. The external 
semicircular canal courses in the processus squamosus prootici, the 
posterior in the cartilage (Fig. 244 cy) between the prootic and 
exoccipital, and the anterior in the prootic. The upper and poste- 
rior part of the anterior semicircular canal is imbedded in cartilage, 
on which rests the parasphenoid. 


c. The perilymphatic space (Fig. 245 I and II. The mem- 
branous labyrinth does not occupy the whole space enclosed by the 
hard parts but is surrounded by the perilymphatie space, which 
contains the perilymph. The periosteum and perichondrium form 
the outer lining of the space, and are for the most part pigmented: 

The perilymphatic space is widest in the lower part of the organ, 
in the region of the fovea sacculi et cochleae, especially externally 
and behind (yer); in front it is much narrower (per'). A little 
higher, in the region of the fegmentum vasculosum, the space is 
wanting, as the membranous labyrinth is here attached to the 
periosteum. 

Around the utricle and saccule the space is comparatively wide ; 
it is continued into the bony canals and ampullae. In the semi- 
circular canals the space is wider on the concave side than on the 
convex side, the membranous canals being placed eccentrically, as 
are also the ampullae, though to a less extent. The periosteum and 


394 THE SKIN AND THE SENSE-ORGANS. 


perichondrium lining this cavity form a very delicate, pigmented 
membrane, formed of numerous fine elastic fibres which cross each 
other irregularly ; its inner surface is lmed with an incomplete 
layer of branched protoplasmic cells with large oval nuclei. From 


ve » 
Fig. 245. 


The membranous labyrinth of Rana esculenta, within its natural covering of periosteum ; 
after Retzius. 


I. Seen from the side ; magnified ten times. 
II. The hinder half ; magnified ten times. Seen obliquely from above, and in front, and from 


the side. 
aa Anterior ampulla. pb Pars basilaris cochleae. 
adf Apertura fenestrae ovalis. per Wider part of perilymphatic space. 
al. Apertura lagenae. per’ Narrower part of perilymphatic space. 
ap. Posterior ampulla, ra. Ramus anterior, 
apb. Opening into the pars basilaris, mm.  Ramulus neglectus. 
ca Anterior semicircular canal. rp. Ramus posterior. 
ce External semicircular canal. rs. Ramulus sacculi. 
cp Posterior semicircular canal. & Saccule. 
do Ductus fenestrae ovalis. sfo Saccus fenestrae ovalis. 
dp Ductus perilymphaticus. spl  Saccus perilymphaticus. 
dp’  Saccus perilymphaticus, tv Tegmentum vasculosum. 
l. Lagena cochlea. uw Utricle. 


ms. Macula sacculia. 
this membrane numerous irregular bundles of fibres, in the form of 
trabeculae, pass into the space and form a rich network, which is 
attached internally to the outer surface of the membranous labyrinth 
and holds it in position. Free nucleated leucocytes are occasionally 
met with in the meshes of this network. The perilymphatic space 
is prolonged into two subsidiary cavities :— 

(1) The ductus fenestra ovalis (Retzius), (Fig. 245 dfo) com- 
mences as an opening (af) immediately opposite the foramen ovale 
of the hard capsule, which leads into a moderately large canal, the 
structure under consideration. It passes forwards and outwards 
through the fenestra ovalis between the interstapedial and the outer 
wall of the capsule into the oval depression (fossa fenestrae ovalis), 


a mt nt ee ees 


PT 


—— =< | 


THE EAR. 395 


and rapidly widens to form a short, flattened, blind sac (saccus 
fenestrae ovalis), which is lodged in the fossa (sfo). Its walls are 
thin and pigmented. 

(2) The ductus perilym- 
phaticus (Hasse), (Fig. 245 
dp) passes above and behind 
the ductus fenestrae ovalis, be- 
hind the auditory nerve, and 
near the cochlea, then behind 
and above the /agena to the 
aquaeductus cochleae (Fig. 244 
ac), where it forms a short, 
wide tube, which passes back- 
wards and inwards through Pau the ower wall the privat sm 
this canal to the canalis jugu- per. Periosteum. . 
laris ; here it lies close to the gay PH ne uit 
nerves and forms a short oval 
sac (saccus perilymphaticus) (dp'), which communicates with the sub- 
arachnoid space of the cranial cavity by means of a tube from the 
neck of the sac. The walls of this structure are thin and formed of 
connective-tissue with very few pigment-cells. The other extremity 
of the tube passes to the pars basilaris and under the sizus post. utri., 
between it and the pars neglecta ; it then courses to the outer side 
of the hinder end of the external semicircular canal: the tube 
then bends downwards to the outer side of the utricle and saccule to 
open into the general perilymphatie space. 

d. The membranous labyrinth (Figs. 247, 248) has the fol- 
lowing parts: the utricle and sinus superior, the recessus ulriculi, 
the anterior semicircular canal and anterior ampulla, the external 
semicircular canal and external ampulla, the posterior semicircular 
canal and the posterior ampulla, the saccule, ductus endolymphaticus, 
and saccus endolymphaticus, the pars neglecta, the lagena cochleae, the 
pars basilaris cochleae, and the so-called tegmentum vasculosum. 

In addition the following nerve-terminations can be distinguished : 
(1) The macula ac. recessus utriculi, (2) the three cristae acusticae am- 
pullorum, (3) the macula ac. sacculi, (4) the macula ac. neglecta, (5) the 
papilla ac. lagenae cochleae, and (6) the papilla ac. basilaris cochleae. 

The auditory nerve divides immediately beyond its origin from 
the medulla oblongata to form a ramus anterior and a ramus posterior, 
which course alongside each other for a short distance, the latter 
lying behind and above the former. The 2. anterior runs forwards 


396 THE SKIN AND THE SENSE-ORGANS. 


and outwards under the utricle, giving off the 2. saccu/i, which runs 
downwards and outwards; the 2. ree. utriculi is then given off as 
a number of fibres, which run upwards and forwards; the main 
nerve then divides to form the 2. ampullae anterioris and the R. am- 
pullae externae, which course together for a short distance and then 
separate to reach their respective ampullae. The 2. posterior runs 
backwards and outwards, gives off the 2. /agenae, and then divides 
to form the ZX. xeglectus, running upwards, the À. basilaris running 
downwards and backwards, and the ZX. ampullae posterioris which 
courses backwards and outwards. 

(1) The utricle (wtriculus) (Figs. 247 and 248 w) is irregularly 
cylindrical in form: commencing at the recessus utriculi it passes 
forwards and outwards ; then backwards, inwards, and upwards, to 
terminate at the sinus posterior, where it is slightly contracted. At 
about its middle it is divided into an anterior and a posterior part by 
an incomplete, sickle-shaped partition, formed by the posterior 
semicircular canal opening obliquely into the utricle, and so 
causing a fold in the posterior wall: on the anterior wall there is 
no fold ; the aperture left in the partition is the apertura utriculi. 

The posterior part of the utricle receives the sinus superior, which 
is formed by the junction of the two vertical semicircular canals. 
The anterior part of the utricle receives the hinder dilated end of 
the external semicircular canal by an opening in its posterior wall, 
close to the apertura utriculi. In the lower wall or floor is the 
narrow opening leading into the saccu/e (canalis utriculo-saccularis) : 
this opening is placed with its long axis parallel to the long 
axis of the utricle, with its broader end posterior, and the narrower 
end anterior. 

(2) The recessus utriculi (Figs. 247 and 248 rec). The anterior 
end of the utricle widens and curves downwards and outwards to 
form the recessus utriculi ; on its floor is a thin, kidney-shaped plate 
or otoliths, resting on the macula ac. recessus utriculi (mu), which re- 
ceives the ramulus rec. utriculi ; under it the ramulus amp. anterioris 
and the ramulus amp. externae run forwards and close together to 
reach their respective ampullae, which are close together at the 
antero-external wall of the recessus utriculi. The otolith is a glassy, 
homogeneous plate, with numerous vacuole-like spaces and striated 
borders ; it covers the whole of the macu/a. 

(3) The anterior ampulla and semicircular canal (Figs. 247, 
248, aa, ca). The anterior ampulla is a rounded, oval vesicle, 
with a depressed roof (Fig. 250 I); on the floor is a transverse 


THE EAR. 397 


low septum, which bears the crista acustica (cr) on its free border ; 
seen from above the crista acustica (Fig. 249 II, aa, cr) has concave 
Fig. 247. 


oily, 


ca 


= 


Ss 


yp 


The right membranous labyrinth of Rana esculenta ; after Retzius, Magnified 20 times. Fig. 247 
seen from the inner side ; Fig. 248 seen from the outer side. 


aa Anterior ampulla. mn Macula acustica neglecta. 7b Ramulus basilaris. 

ae External ampulla ms Macula acustica sacculi. ree Recessus utriculi. 

ap Posterior ampulla. mu Macula acustica recessus 72 Ramulus lagenae. 

apn Apertura partis neglectae. utriculi. 7m Ramulus neglectus. 

au Apertura utriculi. pb Pars basilaris cochleae. rs  Ramulus sacculi. 

ca Anterior semicircular canal. pl  Papilla ac. lagenae. s Saccule, 

ce External semicircular canal. ppb Papilla ac. basilaris sp Sinus utriculi posterior.- 
cp Posterior semicircular canal raa Ramulus ac. anterioris. ss Sinus utriculi superior. 
cus Canalis utriculo-saccularis. rae Ramulus amp. externae. tu Tegmentum vasculosum. 
de  Ductus endolymphaticus. rap Ramulus amp. posterioris. #%  Utriculus. 


1  Lagena cochleae, 


borders anteriorly and posteriorly; the ends are broad, rounded, and 


398 THE SKIN AND THE SENSE-ORGANS. 


somewhat raised ; and in the middle it presents a small elevation 
(Fig. 249 cr). On the crista acustica rests the cupula terminals 
(Fig. 250 I, cu); this is arched above but of the same form as the 
crista acustica below, from which it is separated by an even slit-like 
space ; the ends are not rounded but hollowed out. The substance 
of the cwpula is very soft and has parallel striations, formed of fine 
fibres and running from above downwards ; it separates very easily 
from the evista acustica. The anterior ampulla is directed forwards, 
outwards, and slightly upwards, to open into the anterior semicir- 
cular canal (canalis m. anterior) (ca), which curves first upwards and 
forwards, then backwards, inwards, and upwards, to open by means 
of a shghtly dilated end into the sivus superior utriculi. 

(4) The external ampulla and semicircular canal (Figs. 247, 
248 ae, ce). The external ampulla lies immediately external to the 
anterior ampulla ; it also is an oval vesicle, and corresponds with the 
anterior ampulla in size and shape, except that the roof is higher. 
The roof is directed backwards, the floor forwards; the septum 
transversum is low, placed vertically, and bears a triangular, slightly 
depressed crista acustica: the broader, rounded end of the crista is 
directed upwards, the apex downwards. The corresponding cupula 
terminalis is relatively high, and is of the same shape as the crvsta, 
and is striated. The external ampulla is continuous with the ex- 
ternal semicircular canal (canalis m. externus) (ce), which courses 
outwards and backwards ; then backwards, inwards, and slightly 
upwards, touches the roof of the posterior ampulla; then curves 
forwards and inwards to terminate by a slightly dilated end in the 
anterior part of the utriculus. 

(5) The posterior ampulla and semicircular canal (Figs. 247, 
248, and 249 ap, cp). The posterior ampulla commences at the 
posterior end of the snus post. utriculi, and is directed outwards 
and backwards. It corresponds in all other points with the anterior 
ampulla. The posterior semicircular canal (ce) (canalis m. post.), 
into which the ampulla opens, curves upwards, inwards, and for- 
wards, to open into the upper end of the sixws superior. 

(6) The saccule (s), ductus endolymphaticus (de), and the 
saccus endolymphaticus (Iigs. 247, 248, 249). The saccule (s) 
is an oval vesicle, placed under the anterior part of the utricle and 
directed outwards and downwards ; below it is flattened in a di- 
rection from in front and within, outwards and backwards; above 
it is wider. In the inner and anterior surface is the rounded, oval 
macula acustica sacculi (Figs. 247 and 248 ms), to which is distri- 


THE HAR. 


399 


buted the 2. sacculi (rs) from above; a large otolith rests on the 
macula and occupies a large portion of the cavity, more especially 


the lower portion. 


The tubular ductus endolymphaticus (de) arises 


by a narrow oval opening placed in the upper and inner part of the 


dp. 


Fig. 249. 


LV 
D wipe Yee 


ce. 


The membranous labyrinth of Rana esculenta ; after Retzius. 


Part of membranous labyrinth to show relations of the ductus and saccus endolymphaticus 


to the cochlear part ; magnified. 


The recessus utriculi and the external ampulla ; magnified. 
To show tegmentum vasculosum, pars basilaris, pars neglecta, etc. 
To show relations of the cochlear part to the pars neglecta. 


Ampulla anterior. 
Ampulla externa. 
Apertura lagenae. 

Posterior ampulal. 
Apertura partis neglectae. 
Apertura utriculi. 

Canalis m. anterior. 
External semicircular canal. 


Posterior semicircular canal. 


Opening into pars basilaris. 
Crista acustica. 

Canalis utriculo-saccularis. 
Ductus endolymphaticus. 
Ductus perilymphaticus. 


i, 
ma. 


mn. 
mp. 
pb. 

L Je", 


pl. 
pn. 


ppd. 


ra, 


rad. 


rae, 


Lagena cochleae. 

Macula ac. recessus utri- 
culi. 

Macula ac. neglecta. 

Membrana basilaris. 

Pars basilaris cochleae. 

Dark spot on either side of 
erest of ampulla: 

Pars ac. lagenae. 

Pars neglecta 

Papilla ac. basilaris. 

Ramus anterior. 

Ramulus amp. anterioris. 

Ramulus amp. externa. 


rap. 
rb, 
rec. 
rl. 
mM. 
rp. 
rs. 


u. 


Ramulus amp. posterioris. 
Ramulus basilaris. 
Recussus utriculi. 
Ramulus lagenae. 
Ramulus neglectus. 
Ramus posterior. 
Ramulus sacculi. 
Saccule. 
Posterior 
canal, 
Saccus perilymphaticus. 
Sinus utriculi superior. 
Tegmentum vasculosum. 
Utricle. 


semicircular 


wall, runs upwards and to the angle between the utricle and the 
sinus superior, continues in the same direction for a short space, and 
then curves inwards to pierce the apertura aquaeductus vestibuli, and 
so reach the cranial cavity. It then forms a large, thin-walled sac 


400 THE SKIN AND THE SENSE-ORGANS. 


(saccus endolymphaticus), placed between the brain and cranium. 
The sac is very vascular and contains crystalline otoliths. 

(7) The pars neglecta (Figs. 247, 248, 249) was described by 
Hasse as the ‘first part of the cochlea’ (‘Anfangstheil der Schnecke’), 
but according to Retzius it does not belong to the cochlea. It is 
placed above and in front of the pars basilaris cochleae, above and a 
little behind the /agena cochleae, therefore above the upper and pos- 
terior part of the saccule, and under the middle part of the utricle. 
It is really a prolongation of the saccule, with which it communi- 
cates by an elongated oval opening placed externally and immedi- 
ately below the opening of the canalis utriculo-saccularis. Vt is an 
oval vesicle, with its roof intimately united with the lower wall of 
the utricle; anteriorly it is broad, posteriorly narrowed. The 
macula acustica neglecta is attached to the roof of the vesicle and 
consists of an anterior heart-shaped and a posterior semilunar 
portion united by a narrow connecting piece (Fig. 250 III and VII). 
The ramulus neglectus divides into two branches, which supply the 
two parts of the macula. On the macula acustica neglecta rests the 
membrana tectoria (Deiters) ; the membrane is S-shaped, with the 
anterior end narrow, the posterior broad (Fig. 250 VIT); the borders of 
the membrane are pierced by numerous small round holes, the central 
part has smaller and fewer perforations, and is finely striated. 
From the middle of the posterior part of the upper surface a thicker 
portion projects downwards into the cavity of the pars neglecta; it 
has a narrow, deep notch for the nerve at about its middle; ante- 
riorly it points towards a sickle-shaped piece, which ts curved in- 
wards. Canals run obliquely downwards and inwards from the 
apertures on the superior surface. The membrane is clear, homo- 
geneous, partly finely striated, and corresponds with the membrana 
tectoria of the pars basilaris, ete. 

(8) The lagena cochleae (Figs. 247, 248, and 249 /) is an oval 
swelling of the membranous labyrinth ; it lies close to the sacculus 
with its broader end forwards, the narrower directed backwards. 
By a large rounded opening at the posterior end it communicates 
with the saccule by means of a rounded space common to the /agena 
cochleae and the cochlea. The papilla acustica lagenae (pl) is situated 
in the posterior wall of the /agena ; it is elongated, oval, and supplied 
by the ram. lagenae. 'The papilla is covered by a plate-like otolith 
formed of numerous rounded particles. 

(9) The pars basilaris cochleae (Figs. 247, 248, and 249 ph) is 
placed on the posterior thickened wall of the saccule and lies above 


THE EAR. 401 


and behind the /agena. It forms a small, oval, pocket-like protu- 
berance, with the long axis directed from in front and above, back- 
wards and outwards, its opening being directed forwards and 


The membranous labyrinth of Rana esculenta ; after Retzius. 


I. Transverse section of the anterior ampulla. Magnified 50 times. 
II, Piece from under surface of the cupula from the anterior ampulla. Vérick’s Syst., Obj. VIII, Oc. 3. 
III. The macula acustica neglecta, seen from below. Vérick’s Syst., Obj. IV, Oc. 3. 
IV. Part of wall of the anterior ampulla. 
V. Part of the cochlea, the pars basilaris cut longitudinally. Vérick’s Syst., Obj. I, Oc. 3. 
VI. Longitudinal section of the pars basilaris. Vérick’s Syst., Obj. I, Oc. 3. 
VII. The macula ac. neglecta, seen from below. Vérick’s Syst., Obj. IV, Oc. 3. 
VIII. The pars basilaris, seen from behind and the outer side. Vérick’s Syst., Obj. I, Oc. 3. 
IX. Transverse section of the external ampulla. Magnified 175 times. 


apb Oval opening into sacculo-cochlear space. n Nerve-fibres. 


er  Crista acustica. pb Pars basilaris. 
cu Cupula terminalis. pe’ Area of coarsely granular cells. 
dp Ductus perilymphaticus. ppb Papilla acustica basilaris. 
mb Section of thinner wall of pars basi- r Epithelium on raphe. 
laris. rb Ramulus basilaris. 
mt Tectorial membrane, rm Ramulus neglectus. 
mw Thickened membranous wall. tv Tegmentum vasculosum. 


outwards. The short ram. basilaris passes in from above to supply 
it. The walls of this dilatation are thick and stiff, with the exception 
pd 


402 HE SKIN AND THE SENSE-ORGANS. 


of a small portion, the membrana basilaris (Hasse) (mb), which closes 
the opening into a small dilatation on the anterior inner wall. The 
ramulus basilaris (rb) divides into, at least, two branches, and passes 
close to the membrana basilaris (mb), where the elongated and 
oval papilla ac. basilaris (Fig. 250 ppl) is placed. The papilla 
is covered by a membrana tectoria (Fig. 250 mt), which is often 
found separated from the papilla, probably by the action of the 


Fig. 251. 


Preparations from the ear of Rana esculenta ; after Retzius. 


I. Part of the membranous wall seen from the surface. Vérick, Obj. VI, Oc. 3. 
II. Transverse section of the membranous wall. Vérick, Obj. III, Oc. 3. 
IIT. Epithelium from the neighbourhood of the macula ac. rec. utriculi. Vérick, Obj. III, Oc. 3. 
IV. Branched cells from the yellow spot on the floor of the anterior ampulla. Vérick, Obj, III, 


Oc, 3. 
V. Epithelium from the roof of the anterior ampulla. Vérick, Obj. ILI, Oc. 3. 
re Epithelium of raphe. pe Protoplasmic cells. 
e Pavement epithelium. pg Perilymphatic tissue. 


reagents used. The form of this membrane is peculiar but will 
easily be understood from the figure (Fig. 250 mt). In structure 
it is similar to the corresponding: structures. found in other parts 
of the ear. 

(10) The tegmentum vasculosum (Deiters) (Figs. 245, 248, and 
250 {v) is an oval, shell-shaped dilatation of the membranous laby- 
rinth ; its long axis is directed from above and in front, downwards 
and backwards. The walls of the ¢eymentum are thin and inti- 
mately attached to the periosteum. 

e. The minute structure of the membranous labyrinth (Figs. 


251, 252). 


ET ABS, he WeyE peer 


il POS er D'OR tee ee XX 


tafe? 


THE EAR. 403 


(1) The walls of the membranous labyrinth have the same 
general structure throughout: the walls are usually thicker at 
the nerve terminations, in the ampullae, semicircular canals, pars 
neglecta, and especially the pars basilaris ; the wall of the ¢egmentum 
‘ympani are the thinnest. The walls are transparent, homogeneous, 
refractive, and, at places, show a faint striation, which is, as a rule, 
not due to the presence of fibres ; in parts of the recessus utriculi, 
and in the outer wall of the sacenle, especially near the fegmentum 
vasculosum, more or less distinct fibres can be made out. Sections 
of the wall show spindle-shaped cells, with the processes usually 
arranged parallel to the surfaces; seen from the surface, the cells 
are seen to branch in all directions (Fig. 251 I, 11). In the 
thinner parts of the walls the cells are few or altogether absent. 
The outer surface of the membranous labyrinth is uneven, in conse- 
quence of the attachment of the perilymphatie network.  Blood- 
vessels are also attached to the outer surface, and pierce the wall, 
especially near the nerve-terminations. 

The whole of the inner surface is lined with a , lay er of polygonal, 
tesselated epithelium-cells. The size and height of the epithelium 
varies in different parts. On the outer wall of the saccule the cells 
are large, but on the inner wall small; they are also large in the 
semicircular canals, except on a small raphe on the inner and outer 
side, where they are smaller but higher (Fig. 251 re); in the am- 
pullae the cells are large, except on the roof. In the utricle and 
sinus superior they are also moderately large. In addition to the places 
mentioned, a smaller epithelium is found on the floors of the am- 
pullae, in the recessus utriculi, and near all the nerve-terminations 
and on the sides of the ampullar septa. Surrounding the nerve- 
terminations of the macula rec. utriculi, macula sacculi, and papilla 
lagenae are found narrow, branched, yellowish cells (Fig. 251 pe) 
with spindle-shaped nuclei. Cells of a third kind, first described 
by Deiters, Hasse, and Kuhn, in the fegmentum vasculosum, and in 
the ampullae by Hasse and Kuhn, are also found in the utricle. 
They contain a yellowish pigment, and are collected into two 
sharply differentiated groups in each ampulla (Hasse has one placed 
before and one behind the septum on the floor). The cells are 
cylindrical, the upper parts striated, the lower narrower, and the 
bases again widened to a polygonal, more homogeneous plate, 
which is fixed to the wall.. On the tegmentum vasculosum the corre- 
sponding cells are not so high. 

(2) The nerve-terminations. The larger branches of the auditory 

ee? 


404 THE SKIN AND THE SENSE-ORGANS. 


nerve contain medullated fibres of various dimensions and bipolar, 
spindle-shaped ganglion-cells. The nerves pierce the walls obliquely 
or vertically, and retain their medullary sheaths until near their 
final distribution. On each of the nerve-terminations is found 
nerve-epithelium, which varies in height in different parts. In the 
crista acustica it measures 0075 mm. in height in the middle part, 
o'06 mm. at the sides; on the macula rec. utriculi o‘o9 mm., on the 
macula sacculi 0075 mm., on the papilla lagenae 0:06 mm., on the 
papilla part. basil. 0'045 mm., on the macula neglecta 0075 mm. 
The epithelium is of two kinds, hair-cells and sustentacular cells. 


Fig. 252. 


The nerve-terminations in the membranous labyrinth of Rana esculenta ; after Retzius. 


I. Vertical section through the crista acustica of the anterior ampulla. Vérick’s Syst., Obj. ITI, 
Oc. 3. 
II. Vertical section through the macula ac. recessus utriculi. Vérick’s Syst., Obj. VIII, Oc. 3. 
III. Three isolated hair-cells from the crista ac. of the anterior ampulla. Vérick’s Syst., Obj. VIII, 
Oc. 3. 
IV. Two isolated sustentacular cells from the crista ac. of the anterior ampulla, Vérick’s Syst., 
Obj. VIII, Oc. 3. 
cr Crista acustica. 
cu Cupula terminalis. 
Jz Sustentacular cells. 
h  Hairs of hair-cells. 
hz Hair-cells. 
n  Nerve-fibres. 


a. The hair-cells (Fig. 252 #:) have, on the whole, elongated, 
flask-like forms, but are not all of the same length (0°024-0°04 mm.). 
The free ends of the cells are rounded, flattened, and yellowish, and 
each bears a stiff cilium, which is fixed by a broad base to the cell, 
and thins out towards its free end : the cilia vary in length ; in the 
ampullae their greatest length is 0°13 mm., on the macula rec. 
utriculi o‘o11 mm., and on the papilla lagenae o'017 mm. The 


su Dee. 


THE EYE. 405 


cells are granular, possess rounded oval nuclei, and are fixed by a 
fine, narrow process (Fig. 252 iz), though they usually seem to be 
rounded off without possessing a process. 

B. The sustentacular cells. Under the hair-cells is a finely 
granular substance, possessing numerous rounded oval nuclei, which 
are placed in superimposed rows (Fig. 252 fz), the deepest row 
being placed close together and immediately on the membranous 
wall. After proper treatment and isolation these nuclei are seen to 
belong to narrow, elongated cells, which rest by a slightly widened 
base on the wall, and are continued upwards between the hair-cells 
to reach the surface of the epithelium, where their upper processes 
are again slightly widened. 

y. The nerve-fibres (Fig. 252 #) lose their medullary coats, ascend 
towards the epithelium, and frequently divide to form two unequal 
branches, which ascend to the level of the hair-cells, and curve so as 
to course horizontally as extremely fine varicose fibrillae ; these fre- 
quently form a network, of which the exact method of termination 
has not been made out. In some cases a fine fibril may be traced 
to the base of a hair-cell, but a direct continuation of the one into 
the other has not yet been traced. 


VI. THE EYE. 


(Re-written by the translator,) 


The organ of sight, the eyeball (dudbus oculi), together with its 
appendages (¢utamina oculi), will be described in this chapter. 


A. The Eye is flattened on the outer surface, more convex on the 
inner or deeper surface. Its principal axis is directed from behind, 
forwards and outwards. 

The outer transparent portion of the eyeball is the cornea, which 
forms the outer boundary of the anterior chamber. The larger, white, 
opaque, and inner portion is the sclerotic coat, which, together with 
two deeper tunics, the choroid coat and the retina, enclose the posterior 
chamber of the eye. The pigmented ring placed behind the cornea 
is the iris, and the aperture it encloses the pupil. The lens is placed 
immediately behind the iris. On the inner side the optic nerve 
pierces the sclerotic to enter the eyeball. 


a. The sclerotic coat (sclerotica s. sclera) forms about three- 


406 THE SKIN AND THE SENSE-ORGANS. 


fourths of the surface of the eyeball; posteriorly it is pierced by the 
optic nerve at a point (porus opticus) nearer the temporal side than the 
nasal. The sclerotic coat consists of fibrous tissue externally, with a 
layer of hyaline cartilage internally (Helfreich). The fibrous layer 
pe 253. is formed of bundles of parallel fibres, which cross 
each other, chiefly at right angles (Hoffmann). 
The cartilaginous layer ends just behind the line 
of insertion of the extrinsic muscle” of the eye, 
and is thickest at the point of entrance of the 
optic nerve (Helfreich). 
The sclerotic coat is rich in nerve-fibres, which 
M ne me form a close network; the fibres, however, do 
sclerotic coats after not unite but form the meshes of the network 
by simply crossing each at acute angles. 
The deeper surface of the sclerotic coat is lmned with a layer of 
large endothelial cells (Hoffmann), (Fig. 253), which form the 
outer wall of the capsule of Tenon. 


b. The cornea and the anterior chamber. ‘The cornea forms 
about one-fourth of the surface of the eyeball and is directly con- 
tinuous with the sclerotic. In it five layers can be distinguished : 
a layer of stratified epithelium or conjunctiva, an anterior hyaline 
membrane, the true corneal substance, a posterior hyaline membrane, 
and a layer of endothelium. 


(1) The corneal epithelium is a layer of stratified epithelium 
covering the superficial surface of the cornea. The superficial 
layer forms a beautiful mosaic of polygonal cells; the middle 
layers are polygonal in all sections, while the ee. layer is more 
or less columnar. Except in the most superficial layer, all the cells 
have serrated surfaces. Smaller cells possessing each two nuclei 
are also found between the columnar cells, and are evidently cells in 
process of division ; according to Waldeyer, cell-proliferation may 
also take place in the middle layers. 

The basal or deeper portions of the columnar cells possess a clear 
border, which reminds one of the hyaline border found on the free 
border of columnar epithelium in other parts. The cells are here so 
closely applied to one another that these borders have the appearance 
of a continuous, highly refracting membrane (Rollett) ; according 
to Henle, the border consists of a network of very fine processes from 
the cells above. 


(2) The true corneal substance, and (3) the anterior hya- 


THE EYE. 407 


line membrane. The corneal substance consists of flat bundles 
of fibres arranged in laminae, with cement-substance and connec- 
tive-tissue corpuscles interposed. The fibrils are extremely fine 
(o‘ooo1 mm., Engelmann), and bound together into bundles by 
cement-substance. The bundles of the laminae are arranged at 
various angles, though many are placed at right angles to each 
other (Waldeyer). 
Between the laminae are flattened spaces, which seen in section 
are spindle-shaped. By proper treatment they are seen to be irreg- 
Fig. 254. ular, branched spaces, 
which communicate 
by fine canals and 
form part of the Reck- 
linghausen-canals or 
lymph-system. These 
spaces contain branch- 
ed, connective-tissue 
corpuscles (Toynbee), 
and a colourless fluid. 
The corpuscles (Fig. 
254 e)-do not fill the 
‘ spaces which they 


Oe 
Q À 


MAT 


rr 
4 IY 
a hea 
4 a 
0 


Preparation from cornea of Rana esculenta ; after Klein, occupy. They possess 
Hartnack’s Syst., Obj. VIT, Oc. 3. large nuclei, sur- 
Nerve of first order, } 
Nerve of second order. rounded by granular 
Nerve of third order. “otonl 
Nerve of fourth order. protopiasm. 
Corneal corpuscles, The canals by which 
these spaces communicate (‘ Saftcanälehen ? of Recklinghausen) lie, 
in general, parallel to the surfaces of the cornea, and communi- 
cate by joining at acute angles or by short transverse branches. 
According to Lavdowsky, these canals have a distinct liming 
membrane. 

The anterior hyaline? layer (Bowman’s or Reichert’s lamella) is 
not so well seen in the frog as in some higher animals; it is simply 
a portion of the corneal substance, of somewhat denser structure 
than the rest, into which it passes by a gradual transition. 

(4) The posterior hyaline membrane (Descemet’s membrane) 
is a highly elastic, very transparent layer, placed behind the 
true corneal substance ; in the frog some few bundles of fibres 


8 RQ No SR 


1 Tamanscheff and Schweigger-Seidel consider the anterior and posterior hyaline 
membranes to be composed of fine fibrils. 


408 THE SKIN AND THE SENSE-ORGANS. 


belonging to the true corneal substance appear to pass into the 
posterior hyaline layer, although they cannot be traced further 
through its substance. The structure of the membrane is, in con- 
sequence of its transparency, unknown, though the above ob- 
servation seems to point to a fibrillar origin. 

(5) The corneal endothelium is a single layer of polygonal 
cells of o‘02 mm. diameter. The cells possess the power of altering 

Fig. 255. their shape when stimulated 
(Klebs). 

(6) The nerves of the 
cornea are derived from the 
ramus ophthalmica trigemint ; 
they pierce the sclerotic 
coat in front of the scle- 
rotic cartilage and then 
course towards the cornea, 
at the margin of which they 
form a coarse network of 
medullated fibres. From 
this about thirty nerves pass 


Preparation from cornea of Rana esculenta ; after towards the cornea. which 
Klein. Hartnack’s Syst., Obj. X immers,, Oc. 3. 2 
a Endothelial cells. they enter, and then very 
b Nuclei of endothelial cells. quickly lose the main part 
c Nerves of third order in the tissue of the cornea A 
propria. of their medullary sheaths. 


d Nerves of the fourth order. 


According to Wolff, a por- 
tion of the nerves retain their medullary sheaths, or in some cases 
appear to regain it after having lost it. 

The nerves passing from the plexus (nerves of the first one 
Klein) give off smaller branches, which for a short distance have a 
serpentine or rectilmear course. By a few anastomoses they form 
a loose plexus (nerves of the second order, Klein). After a longer 
or shorter course they give off numerous lateral fibres, or termi- 
nate in several such fibres arising at one point (nerves of the 
third order, Klein). These are distinguished by their size, varying 
only within small limits, and by the possession of more or less 
regularly placed varicosities; the clearer portions are longitu- 
dinally striated as though made up of fibrillae; they have a 
nearly rectilinear course, and, after a longer or shorter course, 
turn into a direction which is at right angles to the former 
one; lastly, they remain for long distances unbranched. These 
nerves are connected one with another by cross fibres running at 


THE EYE. 409 


right angles to them, and in this way a rectangular trellis-work is 
formed. 

The fibrils (nerves of the fourth order) given off by these nerves 
form networks around the connective-tissue corpuscles, but no 
direct connection between nerve and corpuscle has been traced ; 
they always appear to lie on that surface of the corneal corpuscle 
which is directed towards the superficial surface of the cornea 
(Klein). In the endothelium covering the membrane of Descemet 
these fibrils can be traced coursing along the margins of the cells 
(Fig. 255 d), and sometimes undergoing dichotomous division 
(Klein). 

Almost all observers have described these fibrils as possessing 
varicosities ; Hulke, and more recently Wolf, however, deny their 
presence. Lavdowsky traces nerve-fibrils to the nuclei of the 
connective-tissue corpuscles. 

(7) The anterior chamber is the space between the cornea and 
the iris, and is filled with a watery fluid, the aqueous humour. At 
the circumference of the chamber are a number of spaces (spaces of 
Fontana), formed by interruptions in the tissue between the poste- 
rior surface of ‘the cornea and the iris; the result is that bands or 
trabeculae (digamentum pectinatum iridis) pass from the one structure 
to the other, and between these are the spaces of Fontana. 

According to Angelucci these trabeculae are of three kinds : 
trabeculae passing from the cornea to the iris, formed of con- 
nective-tissue ; trabeculae from the cornea to the ciliary processes, 
which contain elastic tissue ; trabeculae from the interstitial con- 
nective-tissue of the ciliary muscle to the cornea, and formed 
almost entirely of elastic tissue. 

At the junction of the cornea and sclerotic, and just in front of the 
spaces of Fontana, is a larger and similar space, which may be traced 
round the whole circumference of the cornea; this, the canal of 
Schlemm (Sènus cireularis iridis), is held to be a venous plexus by 
some observers (Angelucci, and others), according to others it is a 
lymphatic space in connection with the anterior chamber (Schwalbe, 
and others). It is certain that the vessels can be very easily in- 
jected from the anterior chamber, although a direct communication 
has not yet been seen. 

c. The choroid coat and the iris (¢wnica choroidea et iris, tunica 
vasculosa). 

1. The choroid coat lines the deeper surface of the sclerotic 
coat, but is also prolonged under the cornea to form the iris: 


410 THE SKIN AND THE SENSE-ORGANS. 


Eo ee 
LP =~ 


oa EU 


orne 


Vo [JY 


| 


ll 


NUE PTE 
ie 400 4 
2, Ly 
Y 


THE EYE. 411 


The choroid is firmly attached to the sclerotic in two positions, at 
the point of entrance of the optic nerve, and at the line of junction 
of the sclerotic and the cornea. Its external surface is closely 
applied to the deeper surface of the sclerotic, from which it is only 
separated by a very narrow serous cavity (supra-choroidal space), 
and to which it is attached by numerous vessels and nerves. The 
deep surface of the choroid is covered by the retina, to which it 
is closely attached, except at the ora serrata, the attachment being 
especially intimate at the processus ciliares. 

The choroid coat consists of a fibrous layer containing corpuscles 
and traversed by a very rich vascular anastomosis. The corpuscles 
of this layer are deeply pigmented, in some cases to such an extent 
that the oval nucleus cannot be seen ; the fibrous tissue is also pig- 
mented, and has consequently a brownish tinge. That portion of 
the layer immediately below the sclerotic is termed the lamina fusca 
or suprachoroulea, the vessels on the deeper surface forming the 
membrana choriocapillaris. This again is lined on its deeper surface 
by a hyaline membrane. 

a. The arteries (Fig. 256 VI, VII, VIII) supplying this coat 
are two branches of the arteria ophthalmica ; these form a capil- 
lary network (Fig. 256 VII) resembling the corresponding struc- 
ture found in mammals. The meshes have approximately the 
same size, while the capillaries themselves vary considerably in size. 
This network is, however, only complete on the nasal, temporal, 


Fig. 256. 


The vessels of the choroid and iris ; after Hans Virchow. 


I. The two roots of the V. bulbi superior. Magnified to times. 
II. Vessels of the iris. Magnified 9 times. 
Ill. Origin of the ventral vein. 
IV. Schema of the choroid vessels ; seen from the proximal pole. 
V. Transverse section through the choroid at the equator. 
VI. The origin of the choroid arteries from the ophthalmic artery. The greater part of the 
sclerotic has been removed. Left eye twice natural size. A. From the proximal pole. 
B. From the temporal side. 
VII. Part of a choroidal artery attached to the choriocapillaris. Magnified ro times. 
VIII. A portion of the choriocapillaris, more highly magnified. 
IX. The V. ophthalmica and V. bulbi superior on the sclerotic of the right eye. A. Seen from 
proximal pole. B. Seen from above. Twice natural size. 


A Art. ophthalmica. R Branches of the circulus iridis major. 

A’ Art. choroidea. Rd Distal root of vein of under surface of eye. 

An _ R., nasalis of the ophthalmic artery. Rd’ Distal root of nasal vein. 

At  R. temporalis of the ophthalmic artery. Rd’ Proximal root of nasal vein. 

ch Area of membrana choriocapillaris. Rp’ Nasal root of ventral vein. 

Le Outer pigmented layer of choroid, Rp” Temporal root of ventral vein. 

Li Inner pigmented layer of choroid. Vos V. bulbi superior. 

N Optic nerve. | Vh V.hyaloidea. 

Vasa recta. Vo  V.ophthalmica, 

it Transitional part between choriocapillaris Vp. Proximal root of vein of under surface of 
and ventral whorl. eye. 


Transitional part between choriocapillaris Vs’ Nasal root of V. bulbi superior. 
and upper whorl, Vs” Temporal root of V. bulbi superior. 


412 THE SKIN AND THE SENSE-ORGANS. 


and proximal part of the upper surfaces. Towards the corpus 
ciliare the meshes become wider and elongated ; the capillaries then 
unite at acute angles parallel with the longitudinal axis of the 
eye. The network (choriocapillaris) exists in a simple layer within 
the two arteries which form it, and superficial to the veins (Virchow). 

8. The veins of the choroid (Fig. 256 III, IV, IX) are (1) a vein 
which unites at the lowest point of the equator of the eye with the 
V, hyaloidea to form (2) the V. ophthalmica, two small branches of the 
V. bulli superior, which unite outside the sclerotic, and (3) the vasa 
recta, 

(1) The larger vein arises from the greater part of the under 
surface of the eye ; it gives off branches to each side, which radiate to 
form a ‘whorl’ or star-shaped capillary anastomosis (Fig. 256 III), 
the two halves of which have no connection. A proximal and a 
distal root can be distinguished in the anastomosis; the distal lies 
towards the corpus ciliare, and occupies exactly one-fourth of the 
circumference of the choroid at its junction with the corpus ciliare. 

(2) The two branches of the /. budbi superior lie alongside the 
corpus ciliare on the upper surface, and each occupies one-fourth 
of the circumference ; they form a similar though simpler figure 
(Fig. 256 I) to the foregoing, each forming one half. 

(3) The vasa recta are numerous parallel vessels which arise in the 
iris, and coursing centrally empty themselves into the branches of 
the V. bulhi superior on the superior surface, and into the branches 
of the venous capillari ies on the inferior surface. 

2. The iris is covered anteriorly by a layer of endothelium, 
continuous with that covering the posterior surface of the cornea, 
and of similar character. The border of the pupil (margo pupillaris) 
is of a golden colour, outside this bright ring to its outer margin 
(margo ciliaris) the iris is black ; the golden colour is due to the 
presence of cells containing a pale yellow pigment ; the nuclei of 
these cells are round and granular; the cells themselves have 
rounded outlines (Hoffmann). The black portion of the iris con- 
tains more irregular, spindle-shaped cells, with round nuclei, which 
are hidden by a dense mass of pigment-granules (Iwanoff and 
Hoffmann). 

The true substance of the iris consists of muscle, nerves, blood- 
vessels, and a connective-tissue stroma, but on the posterior surface 
is another layer of black, pigmented cells, and this is again covered 
with a hyaline membrane, in which, however, a fibrous structure 
may be made out (Koganeï). 


THE EYE, 413 


The muscle-fibres are long, spindle-cells, which are abruptly 
swollen in the middle, where the nuclei are situated ; the nucleus is 
oval, o’oog—0'0012 mm. in length, 00025 mm. broad, and occupies 
nearly the whole of the swollen part of the cell (Hoffmann, 
Griinhagen). 

According to Koganei the iris possesses a J/. constrictor tridis (/. c. 
Berlin Sitzungsber.), but no 27. dilatator iridis ; in a former publica- 
tion (/.c. Arch. mik. Anat.) he was unable to find any muscular 
fibre, and holds the muscle-fibres of Griinhagen to be connective- 
tissue elements. 

The stroma consists of delicate connective-tissue fibrils, enclosing 
a very large number of pigmented, branched cells. 


a. The arteries of the iris (Fig. 256 IT) arise from an arch (see 
Vessels of Eye) formed by the 4. ophthalmica in the corpus ciliare. 
It commences between the ventral and temporal surfaces by two 
branches: one courses along the temporal border, the other along 
the nasal, to meet each other on the nasal surface; the former 
courses through one-third, the latter embraces two-thirds of the 
circumference at the iris. 

The temporal artery courses along the ciliary border during the 
first third of its course, it then gradually approaches the border of 
the pupil; the nasal artery runs at once towards the pupil. On 
the nasal border of the pupil they anastomose by their branches, 
and so form a circulus iridis major. 

Except near their termination, no small vessels arise from this 
arterial circle ; in Fig. 256 II, for example, only five larger branches 
are given off, three from the temporal side and two from the nasal. 
The five large branches run towards the circumferential border of 
the iris and break up into numerous vessels, which form a very 
irregular and open network. From this network arise the vasa 
recta already described. 


d. The lens is almost spherical, and is composed of cellular ele- 
ments enclosed in a capsule (capsula lentis). 

The capsule is a homogeneous, transparent, structureless, and 
highly elastic membrane. The deeper surface of the anterior cap- 
sule is lined with a simple layer of regular nucleated six-sided 
epithelial cells. | 

The lens itself consists of long, flat fibres ; seen from the surface 
these are broad, narrow edge-wise, and in section six-sided prisms. 
Those lying parallel to the anterior and posterior surfaces are 


414 THE SKIN AND THE SENSE-ORGANS, 


broad and thicker, those towards the border are narrower. These 
cells are striated, both longitudinally and transversely (Arnold). 
The cells near the margin, however, have no transverse striation 
(Hoffmann). The cells of the central parts form a much closer and 
firmer structure than those at the periphery (Arnold). The peri- 
pheral cells are nucleated, and sometimes even possess two nuclei to 
one cell ; the central cells have no nuclei (Arnold). 

The cells are held together by a cement-substance and by their 
serrated surfaces; the serrations are the cause of the transverse 
striations. The fibres of the lens have a simple arrangement : com- 
mencing at the middle point or pole of one surface they pass over 
the equator to the opposite pole; consequently the long borders of 
adjacent cells are in juxtaposition, and their pointed extremities 
meet at points in the axis of the lens (Hoffmann). 

Ritter has described short, nucleated cells in the centre of the 
lens; these are held by Babuchin to be cells which have been 
arrested in their development. 

e. The retina is the innermost coat 
of the eye; in the recent state it is 
pale, soft, and smooth. The structures 
composing it are arranged in ten 
layers; from the deeper surface 
towards the choroid these are: the 
internal limiting) membrane, the 
optic-fibre layer, the ganglion layer, 
the inner molecular layer, the inner 
nuclear layer, the outer molecular 
layer, the outer nuclear layer, the 
external limiting membrane, the layer 


Fibres from the lens of the frog ; after ot rods and cones, and the pigment 
Hoffmann. Magnified 700 times, 74 


layer. 

These layers are held together by connective-tissue elements. 

(1) The internal limiting membrane (Membrana limitans in- 
terna) will be described together with the connective-tissue ele- 
ments (10). 

(2) The optic-fibre layer is formed by the fibres of the optic 
nerve. The nerve-fibres in their course towards the eye are 
possessed of medullary sheaths, but on piercing the sclerotic these 
sheaths are lost. The fibres are now pale, non-medullated, and of 
very varying thickness. In the mass of fibres nothing can be seen 
except an extremely fine fibrillation and very fine varicosities ; the 


THE EYE. 


415 


latter, however, appear to be artificial productions (Hoffmann). 


This layer of fibres extends over the inner 
surface of the retina, and gradually thins 
from the point of entrance of the optic 
nerve to the limits of the retina. 


(3) The ganglion-layer lies immedi- 
ately without the nerve-fibre layer (Fig. 
2584). The ganglion-cells are small and 
usually pear-shaped. The cells possess 
large nuclei, round which is a thin layer 
of very granular protoplasm. The cells 
have inner and outer processes ; the inner 
pass into the nerve-fibre layer, the outer 
into the inner molecular layer in more or 
less radiating directions. Manz claims 
to have traced a direct connection between 
the inner processes and the fibres of the 
nerve-fibre layer. 

Each ganglion-cell, whatever its shape 
or size, has only one inner process, which 
is easily distinguished from the outer 
process by its being more glistening, by 
the possession of varicosities, and because 
this process never branches. 

The outer processes are single(Schwalbe) 
or rarely double (Hoffmann), and have as 
a rule a direction at right angles to the 
inner processes. Hach outer process is 
finely granular, which suggests rather a 
prolongation of the cell-substance than 
a true process. Frequently they are 
branched, sometimes forming two equal 
sized processes, which give off finer 
twigs; at other times they appear to 
pass through the whole of the inner 
molecular layer without undergoing di- 
vision (Schwalbe). The processes do not 
inosculate (Santi Sirena). 


(4) The inner molecular layer (Fig. 


Vertical section through retina of 
frog ; after Hoffmann. Magni- 
fied 5sco times. 


a Internal limiting membrane. 
Ganglion-cell layer. 

ce Internal molecular layer. 

d Internal nuclear layer. 

e External molecular layer, 
External nuclear layer. 


g Layer of rods and cones, 


Pigmented epithelium layer. 
1. Inner segments of rods and 
cones. 
2. Outer segments of rods and 
cones, 
3. Outer transparent segments of 
pigmented epithelium, 


258 ¢) is 0°07-0°08 mm. thick (Hoffmann), and consists of a finely 


416 THE SKIN AND THE SENSE-ORGANS. 


granular mass together with the outer processes of the ganglion- 
layer, and connective-tissue elements. 

The granular matter consists of an extremely fine network or 
reticulum, through which numerous fine fibres course (Schultze, 
Kolliker, Manz, Heinemann, and others); according to Schultze 
the supposed molecules or granules of others (Henle, Merkel, and 
Retzius) are simply the fine meshes of this reticulum. The 
branched, outer processes of the ganglion-cells form a rich anas- 
tomosis in this layer. 

(5) The inner nuclear layer (Fig. 258 4) contains parts of two 
kinds of cellular elements ; these are radial nerve-fibres with large 
nuclei, and connective-tissue elements (see below, par. 10). The 
nerve-fibres are easily distinguished by their spindle-shaped vari- 
cosities ; both cellular elements possess large oval nuclei. The 
bodies of the cells surrounding the nerve nuclei are almost filled 
by the nuclei, which have sharply-defined, rounded nucleoli. The 
fibres to which these cells are attached may be distinguished as 
inner and outer processes ; the inner process is fine, irregularly vari- 
cose, and unbranched ; the outer process is thicker, finely granular, 
and is not varicose (Schwalbe). At the margin of the outer mole- 
cular layer the outer processes divide, usually into two branches, 
and at an acute angle to each other, though sometimes at a right 
angle. The further course of these branches in the outer molecular 
layer is unknown. 

(6) The outer molecular layer (Fig. 258 e) corresponds in 
general with the inner molecular layer as regards its structure ; it 
is, however, much thinner. 

(7 and g) The outer nuclear layer and the layer of rods and 
cones (Figs. 258 7, 9, 259). The rods and cones are intimately 
connected with the elements of the outer nuclear layer, hence the 
two layers are best described together. 

The rods (baci/li) have two parts or limbs, an outer and an inner, 
which differ in structure, and in chemical and physical characters. 
The outer part is highly refractive, the immer more homogeneous 
and less refractive, the two parts being sharply differentiated from 
one another. 

The outer part is also weakly doubly refracting, the inner has no 
trace of this property. The rods are 0'05-0'06 mm, in length, of 
which o‘035-0°04 mm. belongs to the inner limb. The outer 
end of the outer limb is more or less rounded ; the whole has a 
longitudinal striation (Schultze), due to its being composed of 


rounded fibrils, about twenty-four to each rod (Hensen). 


THE EYE. ALT 


The 


fibrils are sharply differentiated from each other and have a slightly 
spiral course; when seen in transverse section these outer limbs 


do not appear to be round 


(Schultze), although 
others hold them to 
be perfectly rounded 


(Hoffmann and others), 
and that the loss of 
the cylindrical form is 
due to the methods of 
treatment. | According 
to Merkel the longitu- 
dinal striation is caused 
by a canalisation of the 
outer limb, which ac- 
cording to him encloses 
the processes of the pig- 
mented epithelial layer ; 
he is also of opinion that 
the spiral appearance is 
an artificial product. In 
the latter opinion he is 
probably wrong, as per- 
fectly fresh rods exa- 
mined in aqueous humour 
show the same spiral 
appearance (Hoffmann) : 
against the canalisation 
view others observe that 
the longitudinal stria- 
tion is most distinct near 
the inner limit of the 
outer limb, and that it 
is impossible to conceive 
that the processes of 
the pigment-cells should 


Various preparations from the eye of the frog: 
chiefly from the retina. 


1. Rod from retina in aqueous humour, showing spiral 

striation. 

2. Three rods and one cone after treatment with osmic acid. 

3, 4, 5. Rods examined in recent state. 

6, 7. Inner segments of two rods after treatment with osmic 

acid, 
a Outer limb. 
b Inner limb. 
e Lenticular body. 
d Nucleus of outer nuclear layer. 
e External limiting membrane. 

8. Nuclear body from inner nuclear layer. 

g. Twin-cone. 

10. Sustentacular fibre of retina. 

11. Surface view of pigmented epithelium of retina. 

12, 13. Isolated pigmented cells of retina. 

14. Four pigmented cells, rods and cones, external limiting 

membrane, and part of outer nuclear layer attached. 

15. Two pigmented cells ; each showing three attached rods. 

16. Muscle-fibre from the iris. 

Figs. 1, 2, 3, 4, 5, 6, 7, 8, 9 are magnified 500 times. Fig. 10, 
300 times. Fig. 16, 4oo times. All are copied from Hoff- 
mann’s figures. 

Figs. 12, 13, 14, 15 are copied from Morano’s figures ; Hart- 
nack, Oc. II, Obj. 9. 


terminate with such extremely regular ends (Hoffmann). 
In the central part of the inner end of the outer limb 
is seen a dark point when the structures are examined in trans- 


verse section (Ritter, Manz, Schiess, Schultze, and others). 


The 


Ee 


418 THE SKIN AND THE SENSE-ORGANS. 


cause of this is not clearly understood ; some hold it to be a 
fibre (Ritter’s fibres), others hold it to be an artificial product 
(Hensen). 

After treatment with certain reagents the outer limbs show a 
transverse striation, which is probably produced by the action of 
these reagents on the sheath of the outer limbs; that a sheath is 
present is proved by its possession of a different refractive index 
(Zenker, Schultze) to the rest of the outer limb, and this transverse 
striation is not seen until the whole organ has undergone consi- 
derable post-mortem changes (Hoffmann). Should this change be 
allowed to proceed a stage further, the outer limbs of the rods split 
transversely and form small dises from 0‘0005-0‘00055 mm. thick ; 
this takes place in the outer limb only. 

The inner segments of the rods (Figs. 258, 259) are short (0°020-— 
0°022 mm.) and of the same thickness as the outer limbs. When 
perfectly fresh they appear homogeneous; very quickly changes 
commence, which are probably due to coagulation. A plano-convex 
figure (Fig. 259) is then seen at the outer portion of the seg- 
ment (lens-shaped figure of Schultze); with staining reagents it 
gives the same reactions as the outer segment of the rods. The 
rest of this segment forms a short cylinder, which probably has no 
distinct sheath (Hoffmann, Merkel) ; some observers are inclined to 
think that a sheath exists (Landolt, Schwalbe). 

The outer segments of the rods are of two chief sizes (Schwalbe). 
Those of the one kind are large; the second variety occurs less fre- 
quently, and the segments are shorter, measuring only o‘002 to 
070025 mm. ‘The inner segment is a long, thread-like process, 
except where it is swollen to enclose the lens-shaped body. 

The rods are much more numerous than the cones, except at one 
small spot (macula lutea) on the posterior surface of the retina, 
where only cones are found (Krause). 

The cones (conz) have each two segments like the rods (Figs. 258, 
259). The outer segments are short (4-5 p), they are slightly 
conical and terminate externally in a blunt point ; they possess a 
longitudinal striation (Schultze), and very easily break up trans- 
versely into small dises, which, however, do not separate so com- 
pletely as in the case of the rods, in consequence of the presence of 
a sheath continuous with a sheath on the inner segment. 

The mner segments (Figs. 258, 259) have convex sides and 
measure 12-14 p; like the corresponding parts of the rods they 
possess lens-shaped bodies at their junction with the outer segments, 


THE EYE. 419 


but the bodies differ in shape, being bi-convex or rather oval in 
form. The inner segments are enclosed in a delicate sheath con- 
tinuous with that of the outer segments. 

In some cases two cones are united to form a twin-cone ; in such 
cases the one is always larger than the other (Fig. 259 9), and has 
several peculiarities which distinguish it from the smaller. 

The smaller or secondary member of a twin-cone is longer, and 
possesses a lens-shaped body which is plano-convex. The larger or 
principal member of a twin-cone is shorter, has a plano-convex 
body, but also an oval, homogeneous, glistening body, which is 
directly attached to the plano-convex body. The shape of the two 
members is also different. 

The outer nuclear layer (Fig. 258 /) is 14-16 p thick; the 
nuclei lie in two layers. The nuclei belonging to rods and cones 
have the same characters, each nucleus being: a large, oval, hyaline 
body, and enclosing a bright nucleolus. Each nucleus is surrounded 
by an extremely thin layer of finely granular matter. The inner 
processes of the nuclear bodies both of the rods and the cones extend 
to the outer molecular layer, are there dilated and serrated, where 
they become attached to the outer molecular layer (Schultze, Hoff- 
mann). In some cases, however, the inner process of the nuclear 
bodies, belonging to the rods, forms only a short fine fibre. 

In the case of twin-cones the corresponding parts in the outer 
nuclear layer possess two nuclei (Schultze). 

(8) The pigment layer (Figs. 258 #4, and 259 11, 12, 13, 14, 15) 
is not intimately attached to the rest of the retina. It consists of 
eylindrical cells in which two parts or segments are sharply diffe- 
rentiated ; the external part, directed towards the choroid coat, is 
of pale, or colourless granular protoplasm, and occupies one-third 
of the length of the cell; this part encloses a large, round, nucleo- 
lated nucleus. This colourless segment of the cell also includes 
one or two bright yellow, fat globules (Morano). Seen from the 
surface the cells are hexagonal (Fig. 259 11). The remaining 
two-thirds of the cells consists of a brush formed of numerous fine 
pigmented processes; the ultimate terminations of the processes, 
which lie parallel to each other, are frequently unpigmented ; each 
cell possesses thirty to forty such processes (Morano). 

The processes extend between the rods and cones as far as the 
external limiting membrane (Figs. 258, 259), or sometimes a little 
further (Merkel, Morano, Hoffmann). The processes from one 
pigment-cell surround a number of rods and cones; according: to 

He 2 


420 THE SKIN AND THE SENSE-ORGANS, 


Morano twelve to fifteen rods and cones may be encased or sur- 
rounded by the processes of a single cell. 

The thickness of this layer varies from 60-70 y; the nuclei of 
the cells have a diameter of 10-12 y, the width of a single cell is 
from 20-25 u (Hoffmann). 


(10) The connective-tissue elements of the retina and the ex- 
ternal and internal limiting membranes. ‘The elements of the 
retina are supported by connective-tissue elements or sustentacular 
cells, which have a radial arrangement, and which form the two 
limiting membranes (Müller). 

Each sustentacular cell (Fig. 259 10) has two segments, an inner 
and an outer, the boundary between these lying in the inner nuclear 
layer, and being marked by the presence of a large oval nucleus. 
The inner segment of each cell terminates internally in a wide ‘ foot ? 
or base, or may form several such after having undergone division 
(Schultze): these bases together form a transparent, thin mem- 
brane, the internal limiting membrane (membrana imitans interna). 

Within the ganglion-layer these cells possess peculiar appen- 
dages, which fit round the ganglion-cells and support them 
(Schwalbe). 

The outer segments of the sustentacular cells extend into tlie 
outer molecular layer, and then break up into irregular processes 
which extend radially to the external limiting membrane, and 
which they probably form. The external limiting membrane 
(membrana limitans externa) is therefore a membrane corresponding 
to the internal limiting membrane, and formed by the flattened 
ends of the processes belonging to the sustentacular cells. 

The sustentacular cells have a distinct, resistant cell-wall 
(Schwalbe) ; the cell-contents are a finely granular protoplasm, and 
a large oval, nucleated nucleus placed in the inner nuclear layer. 


f. The ciliary processes have the same structure as the rest of 
the choroid coat: the vessels form more or less longitudinal meshes 
and are more irregular than in the rest of the choroid. 


g. The posterior chamber and vitreous body (Fig. 260). The 
vitreous humour occupies the greater portion of the cavity of 
the eyeball, 2. e. the posterior chamber. The humour consists of a 
mass of cells enclosed in a transparent hyaloid membrane (mem- 
brana hyaloidea), which is in contact with the internal limiting 
membrane of the retina. 

The cells forming this structure are small, flattened, transparent, 


THE BYE. 421 


and nucleated (Iwanoff and Virchow); according to the former 
observer the cells have contractile powers. 

The hyaloid membrane is described as structureless by Schwalbe, 
as fibrous by Pappenheim, Bowman, and Fuikbeiner. 

The vessels of the vitreous body (Fig. 260) are as follows. The 
A. hyaloidea arises at the lowest point of the corpus ciliare ; it almost 
immediately divides into two branches, which form a ring at a 
distance of about o°5 mm. from the lens and lying on the surface 
of the vitreous body (Fig. 260 I, II). One, À. nasalis, passes to 
the nasal side and courses through one-fourth of the circle; the 


Fig. 260. 


| 


1 


4 


The vessels of the vitreous body ; after Hans Virchow, 


I. Vessels of the vitreous body ; seen from the deeper pole and slightly from above. Magnified 
6 times. 
II. Arteries of the vitreous body of the right eye. 
A Seen from the proximal pole. 
B Seen from the nasal side. 
III. Veins of the vitreous body of the left eye. 

A Seen from the proximal pole. 

B Seen from the nasal side. 
a Nasal vein. 
b Temporal vein. 
€ Branch (constant) of temporal vein. 
n R. nasalis of the ophthalmic artery. 
t RK. temporalis of the ophthalmic artery. 
’ Termination of the R. temporalis. 
V Ventral vein. 


other, À. temporalis, courses through three-fourths of the circle. The 
‘branches are all given. off proximally and at right angles to the circle 
(Fig. 260 I, II). From the ZX. nasalis only one branch arises, from 
the A. temporalis seven, the first of which corresponds in point of 
origin with the branch from the R. xasalis. The branches on the 
nasal and temporal surfaces of the vitreous body are the shortest. 


422 THE SKIN AND THE SENSE-ORGANS. 


These branches form a capillary network (Fig. 260 I) with 
elongated meshes, formed by the capillaries anastomosing at acute 
angles. The capillary network is more dense towards the middle 
of the proximal surface than in other parts. 

The veins arising from this network are three in number (Fig. 
260 III); two of these accompany the arteries from their origin, 
and form a somewhat similar circle around the lens, while the third 
passes backwards along the ventral surface of the vitreous body to 
the papilla nervi optici. The nasal vein, however, takes a more 
proximal course than the corresponding artery, the branches of 
which it crosses ; consequently the venous ring is not so perfect as 
the arterial. The nasal vein is larger and the temporal vein smaller 
than the corresponding arteries. 

The ventral vein is formed near the papilla nervi oplici by the 
union of two smaller branches. The capillary system of these 
vessels has the usual structure of capillaries, the cells being united 
by cement-substance (Zimmermann). 

The blood-vessels of the vitreous body are accompanied by 
lymphatics; according to Iwanoff they completely enclose the 
capillaries: Zimmerman contradicts this view, as he has been un- 
able to find lymphatics on that side of the capillaries directed 
towards the vitreous body. 


B. Appendages of the eye. 


The appendages of the eye are the eye-muscles (see pp. 55-59), 
the eyelids, the Harderian gland, and the lachrymal duct. 


a. The eyelids are two in number, an upper and a lower. The 
upper eyelid is intimately attached to the eyeball and follows the 
movements of that organ. 


The lower eyelid (membrana nictitans) is much larger than 
the upper and has the same functions as the lower eyelid of higher 
vertebrates. It forms a transparent covering for the eyeball, and 
is raised by a special muscle (see p. 58); functionally it takes the 
place of both eyelids of higher vertebrates. 

The lower eyelid is a prolongation of the skin, but has only a 
few pigment-cells, except at its free margin, and no serous glands. 
Mucous glands are found in two or three rows, closely applied to 
one another, on the superficial surface of the lid ; on the deeper surface 
they are wanting. The stroma of the lid, like the cutis, is of con- 
nective-tissue. 

Nerve-fibres can be traced in all directions through the substance 


THE EYE. 423 


of the lid, forming a wide-meshed plexus. Around each gland the 
plexus becomes finer and by numerous branching much closer ; from 
the plexus twigs are given off, which divide to form a number of 
fibrils traceable into the epithelial cells of the glands (Openchowski). 

The vessels of the lower eyelid have been investigated by Stricker, 
(/. c.); according to him they possess some interesting peculiarities. 
Many of these capillaries course within a lymphatic vessel, in 
some places the capillary being contracted by a projection from 


Fig. 261. 


Preparations from the nictitating membrane of Rana esculenta to show distribution of nerves. 


I. Preparation of the nictitating membrane to show nervous supply to a capillary vessel ; after 
Klein. Hartnack, Oc. III, Obj. 8. 
a Capillary vessel. 
b Blood-corpuscles. 
c and d Non-medullated nerve-fibres. 


II. To show distribution of nerves in the epithelium ; after Klein. Hartnack, Oc. IV, Obj. 8. 
4 } Subepithelial nerve-fibres. 


e Fine fibrils between the deepest epithelial cells. 
d Deepest epithelial cells. 


‘ 


its inner wall; where this is found the accompanying lymphatic 
is correspondingly dilated. Such points are especially met with 
where the capillaries branch ; in many cases the capillary was con- 
tracted to such an extent that the blood-corpuscles were unable 
to pass the obstruction. Stricker further observed in the living 
tissue that such constrictions could take place in a part which a 
short time previously had been comparatively wide and dilated ; 
further, that many of the nerves were enclosed in similar lymphatics. 
Langer, however (/. c.), describes the vessels as being accompanied 
by an irregular network of small lymphatic vessels. 

The distribution of the nerves in the lower eyelid has been de- 
scribed by Klein. In the epithelium they form a network re- 
sembling that found in the cornea (Fig. 261 IL) ; along the blood- 
vessels the fine fibrils form a perivascular network, which supplies 


424 THE SKIN AND THE SENSE-ORGANS. 


fine twigs to the walls of the vessels (Fig. 261 I). He dis- 
tinguishes three kinds of pigmented cells. 


b. The Harderian gland is situated at the inner angle of the 
eye, and is pear-shaped in form. It consists of a number of 
racemose glands held together by connective-tissue, the whole being 
enclosed in a relatively thick and strong capsule of connective- 
tissue. 

The alveoli have a diameter of 0-040-0'060 mm. : they possess a 
lining of epithelium and a lumen which varies considerably in size. 
The epithelial layer is bounded externally by a membrana propria. 
The cells are placed eccentrically, they are cylindrical, and com- 
posed of finely granular protoplasm; each cell contains a pale, 
rounded nucleus. The ducts of the alveoli are lined with a 
single layer of cylindrical epithelium, the cells of which are usually 
shorter and narrower than those of the epithelium of the alveoli; 
the ducts open into a single main tube, lined with similar epithelium 
but strengthened externally by a layer of connective-tissue. The 
glands secrete a fluid which moistens the free surface of the eye. 

The Harderian glands are surrounded by a rich capillary anasto- 
mosis which completely invests the alveoli. 


e. The lachrymal duct opens behind and below into the nasal 
cavity (see p. 389), anteriorly it can be traced forwards, as a small 
tube imbedded in connective-tissue and lying immediately beneath 
the skin, to the outer angle of the eye, where it opens by numerous 
tubules. 

The lachrymal duct is lmed with ciliated columnar epithelium. 


ADDENDA. 


HISTOLOGY OF MUSCLE, CARTILAGE, BONE, 
AND THE CONNECTIVE TISSUES. 


LITERATURE. 


I. MUSCLE AND NERVE-ENDINGS IN MUSCLE. 


Arnold, J., Gewebe der organischen Muskeln. Stricker’s Gewebelehre, 1871. Vol. I, 
p- 142. 

Arnold, J., Ueber die Abscheidung des indigschwefelsauren Natrons im Muskel- 
gewebe. Virchow’s Arch. Vol. LXXI, p. 1. 

Babuchin, Ueber den feineren und Ursprung des Axencylinders. Centralbl. f. med. 
Wiss. 1868, p. 755. 

Barfurth, D., Die Riickbildung des Froschlarvenschwanzes und die sogenannten 
Sarkoplasten. Arch. f. mik. Anat. 1887. Vol. XXIX, p. 35. 

Biedermann, W., Zur Lehre vom Bau der quergestreiften Muskelfaser. Wiener 
Sitzungsber. 1876. Vol. LXXIV, Pt. III, pp. 49-62. 

v. Biesiadecki, A., and Herzig, A., Die verschiedenen Formen der quergestreiften 
Muskelfasern. Wiener Sitzungsber. 1859, Vol. XXXIII, p. 146: and in 
Moleschott’s Untersuchungen, 1860, Vol. VI, p. 105. 

du Bois-Reymond, E., Ueber facettenformige Endigung der Muskelbiindel. Berlin. 
Acad. Monatsber. 1872, pp. 791-814. Abstract in Centralbl. f. d. med. Wiss. 
1873. No. 55, p. 868. 

Bowman. On the minute structure and movements of voluntary muscle. Phil. 
Trans. 1840, p. 457. 

Bremer, L., Ueber die Endigungen der markhaltigen und marklosen Nerven im 
quergestreiften Muskel. Arch. f. mik. Anat. 1882. Vol. XXI, p. 165. 

‘ Bremer, L., Ueber die Muskelspindeln nebst Bemerkungen über Structur, Neubil- 
dung, und Innervation der quergestreiften Muskelfaser. Arch. f. mik. Anat. 
1883.. Vol. XXII, p. 318. 

Calberla, E., Studien tiber die Entwicklung der quergestreiften Muskeln und 
Nerven der Amphibien und Reptilien. Arch. f. mik. Anat. 1875. Vol. XI, 
P- 442. 

Calberla, E., Ueber die Endigungsweise der Nerven in den quergestreiften Muskeln 
der Amphibien. Dissert. Freiburg i. B. 1874; also in Zeitschr. f. d. wiss. Zool. 
1874. Vol. XXIV, pp. 164-178. 

Chittenden, R. H., Histochemische Untersuchungen iiber das Sarkolemm und 
einige verwandte Membranen. Untersuch. d. physiol. Instituts d. Universitit 
Heidelberg. Vol. III. 

Cohnheim, J., Ueber die Endigung der Muskelnerven. Centralbl. f. d. med. Wiss. 
1863, p. 865. 

Eberth, C. J., Untersuchungen iiber die normale und pathologische Leber. Vir- 
chow’s Arch. 1864. Vol. XX XIX, p. 74. | 

Engelmann, T. W., Zur Lehre von der Nervenendigung im Muskel. Jenaische 
Zeitschr. 1868. Vol. IV, p. 307. 

Engelmann, T. W., Untersuchungen iiber den Zusammenh. von Nerven u. 
Muskelfasern. Leipzig, 1863. 


LITERATURE. 427 


Engelmann, T. W., Microscopische Untersuchungen iiber die quergestreifte 
Muskelsubstanz. Pfliiger’s Arch. 1873. Vol. VII, pp. 33-71, and pp. 155-187. 

Engelmann, T. W., Ueber die Endigung der motorischen Nerven in den quer- 
gestreiften Muskeln der Wirbelthiere. Centralbl. f. med. Wiss. 1863, p. 289. 

Ewald, A., Ueber die Endigung der motorischen Nerven in den quergestreiften 
Muskeln. Pfiiiger’s Arch. 1876. Vol. XII, p. 529. 

Ewald, A., and Kühne, W., Die Verdauung als histologische Methode. Heidelb. 
naturhistor.-med. Verhandl. 1877. Vol. I, p. 451. 

Exner, S., Notiz zu der Frage von der Faserverteilung mehrerer Nerven in einem 
Muskel. Pflüger’s Arch. 1885. Vol. XXXVI, p. 572. 

Fischer, E., Ueber die Endigung der Nerven im quergestreiften Muskel der Wir- 
belthiere. Arch. f. mikrosk. Anat. 1877. Vol. XIII, p. 365. 

Froriep, A., Ueber das Sarcolemm und die Muskelkerne. Arch. f. Anat. u. Physiol. 
1878, p. 416. 

Gerlach, J., Ueber das Verhalten der Nerven in den quergestreiften Muskelfäden 
der Wirbelthiere. Sitzungsb. Erlangen. 1873. Vol. V, p. 97; Abstract in 
Centralbl. f. d. med. Wiss. 1874, p. 227. 

Gerlach, J., Das Verhältniss der Nerven zu den willkiirlichen Muskeln der Wir- 
belthiere. Leipzig, 1874. 

Gerlach, J., Ueber das Verhältniss der nervüsen und contractilen Substanz des 
quergestreiften Muskels. Arch. f. mik. Anat. 1877. Vol. XIII, p. 399. 

Golgi, C., Sui Nervi dei Tendini dell’ Uomo e di altri Vertebrati e di un nuovo 
Organo Nervoso terminale Musculo-tendineo. Torino. Estr. dalle Memorie 
della Reale Ace. di Torino. Series II. 1880, Vol. XXXII. 

Grützner, P., Zur Anatomie und Physiologie der quergestreiften Muskeln. Recueil 
Zoolog. Suisse, 1884. Vol. I, pp. 665-684. 

Haycraft, J. B., Upon the cause of the striation of voluntary muscular tissue. 
Quart. Journ. Micros. Soc. 1881. Vol. X XI, p. 307. 

Hensche, Ueber die Driisen und glatten Muskeln in der äusseren Haut von Rana 
temporaria. Zeitschr. f. wiss. Zool. 1856. Vol. VII, p. 273. 

Hensen, V., Ueber die Entwicklung des Gewebes und der Nerven im Schwanze der 
Froschlarve. Virchow’s Arch. 1864. Vol. XXX, p. 51. 

Jakimovitsch, Ueber die Regeneration der glatten Muskelfasern. Centralbl. f. d. 
med. Wiss. 1879, p. 897. 

Key, A., Bidrag till Nervernas ändningsätt i Musklerna. Fürhandlingar vid 
Skandinaviska Naturforskaemôütet i Stockholm, 1863. Abstract in Centralbl. f. 
d. med. Wiss. 1866, p. 212. (Muscles of frog’s tongue.) 

Klebs, E., Die Nerven der organischen Muskeln. Centralbl. f.d. med. Wiss. 1863, 
p- 561. 

Klebs, E., Die Nerven der organischen Muskeln. Virchow’s Arch. 1865. Vol. 
XXXII, pp. 169-198. 

v. Kélliker, A., Gewebelehre. 

v. Kélliker, A., Einige Bemerkungen über die Endigung der Hautnerven u. den Bau 
der Muskeln. Zeitschr. f. wiss. Zool. 1857. Vol. VIII, p. 311. 
Krause, W., Ueber den Bau der quergestreiften Muskelfaser, Zeitschr. f. rat. Med. 

Vol. XXIII. 

Krause, W., Die Nervenendigungen in den Froschmuskeln. Internat. Monatschr. 
1884. Vol. I, pp. 194-203. 

Krause, W., Die motorischen Endplatten, etc. Hannover, 1860. 

Krause, W., Ueber die Endigungen der Muskelnerven. Güttinger Nachrichten. 
1863, p. 21. 

Krause, W., Ueber die Endigungen der Muskelnerven. Henle and Pfeufer’s 
Zeitschr. 1863. Vol. XX, pp. 1-10. 

Kühne, W., Untersuchungen über Bewegungen und Veränderungen der contractilen 
Substanzen. Arch. f. Anat. u. Phys. 1859, p. 816. 


428 MUSCLE, CARTILAGE, BONE, AND CONNECTIVE TISSUES. 


Kühne, W., Die Muskelspindeln. Virchow’s Arch. 1864. Vol. XX VIII, pp. 528-538. 

Kühne, W., Untersuchungen über das Protoplasma und die Contractilität. Leipzig, 
1864. 

Kühne, W., Ueber die peripherischen Endorgane der motorischen Nerven. Leipzig, 
1862. 

Kihne, W., Zur Lehre von den Endplatten der Nervenhiigel. Virchow’s Arch. 
1866. Vol. XXXIV, pp. 412-422. 

Kühne, W., Ueber das Verhalten des Muskels zum Nerven. Verhandl. d. natur- 
hist.-med. Vereins zu Heidelberg. 1880. Vol. II, p. 227. 

Kühne, W., Ueber Nervenendigungen in den Muskeln nach Beobachtungen von 
M. B. van Sykel. Abdruk. aus den Verhandl. d. Naturh. med. Verein zu Heidel- 
berg. 1884. Vol. III, pp. 238-242. 

Kühne, W., Wiederlegung der Bemerkung E. du Bois-Reymond’s über mehrfache. 
Nervenendigungen einer Muskelfaser. Zeitschr. f. Biol. 1884. Vol. XX, pp. 
5315539: 

Kühne, W., Ueber die Endigung der Nerven in den Muskeln. Virchow’s Arch. 
1866. Vol. XX VII, pp. 508-533. 

Kühne, W., and Voit, C., Neue Untersuchungen über motorische Nervenendigung. 
Zeitschr. f. Biologie. Vol. XX XIII. 

Lavdowsky, M., Die feinere Struktur und die Nervenendigungen der Froschharn- 
blase. Arch. f. Anat. u. Physiol. 1872, p. 55. 

Leboucq, H., Recherches sur le développement et la terminaison des nerves chez 
les larves des Batrachiens. Bull. de l’Acad. de roy. de Belgique. 1876. Vol. 
XLI, p. 561. 

Letzerich, L., Ueber die Endigungsweise der motorischen Nerven. Med. Centralz. 
1863, No. 37. 

Leydig, F., Ueber Tastkürperchen und Muskelstructur. Arch. f. Anat. u. Physiol. 
1856, p. 150. 

Lôwit, Die Nerven der glatten Muskulatur. Sitzungsb. d. Wiener Acad. 1875. 
Vol. LXXI, Pt. III, p. 355. 

Marshall, C. F., The structure and distribution of striped and unstriped muscle. 
Quart. Journ. Micros. Sci. 1887. Vol. XXV. 

Martin, H., Sur la structure de la fibre musculaire striée et sur les analogies de 
structure et fonction entre les tissus musculaires et les cellules à batonnets 
(protoplasma strié). Arch. de physiol. norm. et pathol. 1882, p. 465. 

Mayer, S., Die sogenannten Sarkoplasten. Anat. Anzeiger, 1886. No. 9, p. 231. 

Mayer, S., Einige Bemerkungen zur Lehre von der Riickbildung der quergestreiften 
Muskelfasern. Prager Zeitschr. f. Heilkde. 1887. Vol. VIII, p. 177. 

Mays, K., Histo-physiol. Untersuchungen iiber die Verbreitung der Nerven in den 
Muskeln. Zeitschr. f. Biol. Vol. XX. 

Mays, K., Ueber die Nervatur des Musculus rectus abdominis des Frosches, 
Heidelberg, 1886. 

Melland, B., A simplified view of the histology of the striped muscle-fibre. Quart. 
Journ. Micros. Sci. 1885. Vol. XXV, p. 371. 

Merkel, F., Der quergestreifte Muskel. Arch. f. mik. Anat. 1873. Vol. IX, 
pp. 293-367. 

Minra, M., Untersuchungen iiber die motorischen Nervenendigungen der querge- 
streiften Muskelfasern. Virchow’s Arch. 1886. Vol. CV, p. 129. 

Nasse, O., Zur Anatomie und Physiologie der quergestreiften Muskelfasern. Leipzig, 
1882. Abstract in Centralbl. f. d. med. Wiss. 1882, pp. 884 and go8. 

Newman, D., New theory of contraction of striated muscle and demonstration of 
the composition of the broad dark bands. Journ. of Anat. and Physiol. 1879, p. 4. 

Nicolaides, R., Ueber die caryokynetischen Erscheinungen der Muskelkorper 
während des Wachstums der quergestreiften Muskeln. Arch. f, Anat. u. Physiol. 


1883, p. 441. 


———— ee 


LITERATURE. 429 


Odenias, M. W., Undersékungen üfer de sensibla muskelnervena, Nord. Medic. 
Arch. Vol. IV, No. 18. 

Paneth, J., Die Entwickelung von quergestreiften Muskelfasern aus Sarkoplasten. 
Wiener Sitzungsber. 1886. Vol. XCII, Pt. III, p. 561. 

Petrowsky, Zur Frage über das Wachstum der Muskelfasern des Muskelgewebes beim 
Frosch. Med. Centralbl. No. 49, pp. 769-772. 

Pohl-Pincus, Ueber die Muskelfasern des Froschherzens. Arch. f. mik. Anat. 1884, 
Vol. XXIII, p. 500 ; and Verhandl. der Physiol. Gesell. zu Berlin. 1882-3. No.9. 

Ranvier, L., Appareils nerveux terminaux des muscles de la vie organique; cceurs 
sanguins, cœurs lymphatiques; cesophagus; muscles lisses. Leçons recueillies 
par Weber et Lataste. Leçons d Anatomie générale faites au Collège de France. 
Paris, 1880. Vol. VII, p. 350. 

Ranvier, L., Leçons sur l’histologie du Système nerveux. 1878. Vol. II. 

Reichert, K. E., Ueber das Verhalten der Nervenfasern bei dem Verlauf und En- 
digung in einem Hautmuskel des Frosches, Rana temporaria. Arch. f. Anat. 
u. Physiol. 1851, p. 29. 

Retzius, Zur Kenntniss der quergestreiften Muskelfaser. Biologische Unter- 
suchungen. 1881, p. I. 

Rouget, Note sur la terminaison des nerfs moteurs dans les muscles chez les reptiles, 
les oiseaux et les mammifères. Comptes rendus. 1862. LV, p. 548. 

Sachs, C., Die quergestreifte Muskelfaser. Arch. f. Anat, u. Physiol, 1872, 
pp. 607-648. 

Sachs, C., Die Nerven der Sehnen. Arch. f. Anat, u. Physiol. 1875, p. 402. 

Sandmann, D. G., Ueber die Verteilung der motorischen Nervenendapparate in 
den quergestreiften Muskeln der Wirbelthiere. Arch, f. Anat. u. Physiol. 
1885, p. 240. 

Schénn, Anatomische Untersuchungen im Bereich des Muskel- und Nervengewebes. 
Jenaische Zeitschr. 1865. Vol. II, pp. 26-60. 

Schultze, M., Ueber Muskelk6rperchen und das was man eine Zelle zu nennen habe. 
Arch. f. Anat. u. Physiol. 1816, p. 17. 

Sokolow, A. A., Sur les transformations der terminaisons des nerfs dans les muscles 
de la grenouille après les section des nerfs. Arch, de Physiol. normale et patho- 
logique, 1874, pp. 300-315. 

Sokolow, A. A., Ueber die Nervenendigungen in den Muskeln ausgehungerter 
Frésche. Medicin. Bote. 1876, St. Petersburg. 

Tergast, P., Ueber das Verhältniss von Nerve und Muskel. Arch. f. mik, Anat. 
To 734) Vol, LUXS ps 20. 

v. Thanhoffer, L., Beitriige zur Histologie und Nervenendigung der quergestreiften 
Muskelfasern. Arch. f. mik. Anat, 1882. Vol. XXI, p. 26. 

Thin, G., On the structure of muscular fibre. Quart. Journ. Microsc. Sci. 1877. 
Vol. XVI, pp. 251-250. 

Tolotschinoff, Ueber das Verhalten der Nerven zu den glatten Muskelfasern der 
Froschharnblase. Arch. f. mik. Anat. 1869. Vol. V, p. 510. 

Trinchese, S., Mémoire sur la terminaison périphérique des nerfs moteurs dans la 
série animale. Journ. de l’Anat. et de la Physiol. 1867, pp. 485-504 (original 
in Italian, 1867). 

Tschiriew, S., Sur les terminaisons nerveuses dans les muscles striés. Arch. de 
physiol. norm. et path. 1879. Vol. VI, p. 80. 

Tschiriew, S., Sur les terminaisons nerveuses dans les muscles striés. Compt. rend. 
1878. Vol. LXXXVII, p. 604. 

Unger, Untersuchungen über die quergestreiften Muskelfasern des lebenden Thieres. 
Wiener med. Jahrb. 1879, p. 61; and in Centralbl. f. d. med. Wiss. 1870, 
No. 34, p. 622. 

Wagener, G. R., Ueber die Verbindung von Muskel und Sehne unter einander. 
Sitzungsber. naturw. Gesells. Marburg. 1874, pp. 38-46. 


430 MUSCLE, CARTILAGE, BONE, AND CONNECTIVE TISSUES. 


Waldeyer, W., Ueber die Endigung der motorischen Nerven in den quergestreiften 
Muskeln. Centre, f. d. med. Wiss. 1863, p. 360. 

Waldeyer, W., Untersuchungen über den Ursprung und den Verlauf des Axen- 
cylinders bei Wirbellosen und Wirbelthieren, sowie über dessen Endverhalten 
in der quergestreiften Muskelfaser. Henle and Pfeuffer’s Zeitschr. 1864. Vol. 
XX, pp. 193-257. 

Weismann, A., Ueber die Musculatur des Herzens beim Menschen und in der 
Thierreihe. Arch. f. Anat. u. Physiol. 1861, p. 41. 

Wolff, W., Ueber den Zusammenhang des Muskels mit der Sehne. Diss. Berlin, 
1877; Abstract in Centralbl. f. d. med. Wiss. 1877, p. 733. 


Consult also: Arnold, J., Kühne, W., and Schweigger-Seidel, F., in Stricker’s 
Handbuch der Gewebelehre. 


Il. CARTILAGE AND BONE. 


Arnold, J., Ueber die Abscheidung des indigschwefelsauren Natrons im Knochen- 
gewebe. Virchow’s Arch. 1877. Vol. LXXI, p.17. — 

Arnold, J., Die Ausscheidung des indigschwefelsauren Narions im Knorpelgewebe. 
Virchow’s Arch. 1878. Vol. LX XIII, p. 125. 

Bigelow, W. S., Notiz über den Theilungsvorgang bei Knorpelzellen sowie über 
den Bau des Hyalinknorpels. Arch. f. mik. Anat. 1879. Vol. XVI, p. 457. 

Boll, F., Untersuchungen tiber den Bau und die Entwicklung der Gewebe. Arch. 
f. mik. Anat. 1871. Vol. VII, p. 275. 

Bruch, C., Ueber die Verknücherung der Wirbelsäule bei den Batrachiern. Wiirzb. 
naturw. Zeitschr. 1862. Vol. III, pp. 225-238. 

Bush, F., Das Knochengewebe der Batrachier nach den Untersuchungen von N. 
Kastschenko. Verhandl. d. physiol. Gesells. zu Berlin. 1881, pp. 358-361. 
Flesch, Untersuchungen tiber die Grundsubstance des Hyalinknorpels. Wiirzburg, 

1880. 

Heidenhain, Zur Kenntniss des hyalinen Knorpels. Studien aus d. physiol. Inst. 
zu Breslau. 1863. Pt. II, p. 1. 

Hertwig, O., Anatomisch Pelle te Untersuchung des Skalets der Mundhôhle und 
der Zähne der Amphibien ; supplement to Vol. XI. Arch. f. mikroskopische 
Anat. 1874, pp. 29-32. 

Kastschenko, N., Ueber die Genese und Architectur der Batrachierknochen. Arch. 
f. mik. Anat. 1881. Vol. XIX, pp. 1-52. 

Kastschenko, N., Ueber die Krappfärbung der Froschgewebe. Arch. f. mik. Anat. 
1882. Vol. XXI, p. 357. 

v. Kélliker, Gewebelehre Leipzig. 1867, p. 66. 

Lehmann, J. C., Ueber den Knorpel in der Achillessehne des Frosches. Zeitschr. 
f. wiss. Zool. 1864. Vol. XIV, p. 100. 

Levschin, L., Ueber die Entwicklung des Knochengewebes des Frosches. Centralbl. 
f. med. Wiss. Nos. 18, 19. 

Mays, C., Ueber den Bau der Sehnen, ete. Virchow’s Arch. 1879. Vol. LXXV, 
p- I12. 

Renaud, M. J., Système hyalin de soutènement des centres nerveux et de quelques 
organes des sens. Arch. de Physiol. 1881, p. 6. 

Schleicher, W., Die Knorpelzelltheilung. Arch. f. mik. Anat. 1879. Vol. XVI, 

. 248. 

Be a Ueber die Saftbahnen des hyalinen Knorpels. Wiener Sitzungsber. 
1879. Vol. LXXX, Pt. III, p. 267. 

Stadelmann, E., Die Histologie des ‘ Pseudoknorpels’ in der Achillessehne des 
Frosches, ete. Virchow’s Arch. 1880, Vol. LXXX, p. 105; also as Dissert. 
inaug. Kénigsberg, 1878. 


LITERATURE. 431 


van Stricht, O., Recherches sur le cartilage hyalin. Annales de la société de médi 
cine de Grand. 1885, pp. 221-232. 

‘Thin, G., On the structure of hyaline cartilage. Quart. Journ. Micros. Sci. 1876. 
Mol XVI pp. 1-22: 

v. Tôrôk, A., Der feinere Bau des Knorpels des Achillessehne des Frosches. Cen- 
tralbl. f. d. med. Wiss. 1872, No. 5,p. 66; and Verhandl. d. phys.-med. Gesells. zu 
Wiirzburg, 1872, Vol. III, pp. 1-26. 


Ill. THE CONNECTIVE TISSUES. 


Billroth, T., Ueber die Epithelzellen der Froschzunge, den Bau des Cylinder- und 
Flimmerepithel und ihr Verhaltniss zum Bindegewebe. Arch. f. Anat. u. 
Physiol. 1858, p. 159. 

Bizzozero, G., Ueber den Bau des Sehnengewebes. Moleschott’s Untersuchungen. 
1876. Vol. XI, p. 36. 

Bobinzky, C., Zur Kenntniss des Baues, der Entwicklung und der regressiven 
Metamorphose der Fetzellen. Centralbl. f. d. med. Wiss. 1885. No. 43, 
PP: 753-755- 

Boll, F., Untersuchungen tiber den Bau und die Entwicklung der Gewebe. Arch. 
f. mik. Anat. 1871. Vol. VII, p. 276. 

Ciaccio, G. V., Nuove Ricerche sull interna tessitura dei tendi. Memorie dell’ 
Academie delle scienze dell Istituto di Bologna, 1872. Series III, Vol. II. 
Abstract in Centralbl. f. d. med. Wiss. 1873. 

Czumak, J., Notiz über elastische Sehnen. Centralbl. f. med. Wiss. 1863, p. 785. 

Flemming, W., Ueber Bildung und Rückbildung der Fettzelle im Bindegewebe ; 
und Bemerkungen tiber die Structur des letztern. Arch. f. mik. Anat. 1871. 
Mol Vall, ps 32: 

Gerlach, J., Ueber Bindegewebe. Sitzungsb. d. phys.-med. Societät zu Erlangen. 
1872, p. 78. 

Ginsburg, L., Ueber das Verhalten der Sehnenzellen bei der Entziindung.  Vir- 
chow’s Arch, 1882. Vol. LXXXVIII, p. 263. 

Golgi, C., Sui Nervi dei Tendini dell’ Uomo e di altri Vertebrati e di un nuovo 
Organo nervoso terminale Musculo-tendineo. Estr. dalle Memorie della Reale 
Acc. di Torino. 1880. Series II, Vol. XXXII, p. 29; No. 6, p. 86. 

Hensen, V., Ueber die Entwicklung des Gewebes und der Nerven im Schwanze der 
Froschlarve Virchow’s Arch. 1864. Vol. XXXI, p. 51. 

Hoyer, Ueber den Bau der Cylinder- und Flimmerepithelien und ihr Verhiltniss 
zum Bindegewebe. Arch. f. Anat. u. Physiol. 1838, p. 163; also Deutsche 
Klinik. 1857, No. 21. 

Iwanoff, A., Beitrage zur normalen und pathologischen Anatomie des Frosch-Glas- 
korpers. Centralbl. f. d. med. Wiss. 1868, p. 129. 

Kollmann, Ueber den Bau der Sehne. Münchener Sitzungsber. 1878. Abstract in 
Centralbl. f. d. med. Wiss. 1879, p. 881. 

Maddox, On the apparent relation of nerve to connective-tissue corpuscles. Proc. 
Roy. Soc. Lond. 1868. Vol. XVI, p. 61. 

Mays, C., Ueber den Bau der Sehnen mit besondere Beriicksichtigung iiber Saft- 
bahnen. Virchow’s Arch. 1879. Vol. LX XV, p. 112. 

Sachs, C., Die Nerven der Sehnen. Arch. f. Anat. u. Physiol. 1875, p. 402. 

Spina, A., Untersuchungen des lebenden Bindegewebes. Oesterr. med. Jahrb. 
1884. Pt. II. 


NOTE BY THE TRANSLATOR. 


REFERENCE has already been made to the views of Messrs. Melland 
and Marshall on the structure of muscle-fibres. The opinion that 
the striation of voluntary muscle is wholly or in part due to the 
presence of a regularly arranged network was previously published 
by Retzius, Bremer, and others. The authors referred to have 
now for the first time shown the importance of this network in 
all vertebrate muscular tissues, whether voluntary or involuntary. 

Mr. Marshall gives the following summary of the result of his 
researches, which the Translator has confirmed by his own obser- 
vations :— 

1. In all muscles which have to perform rapid and frequent move- 
ments, a certain portion of the muscle is differentiated to perform 
the function of contraction, and this portion takes on the form of 
a very regular and highly modified intracellular network. 

2. This network, by its regular arrangement, gives rise to certain 
optical effects which cause the peculiar appearances of striped 
muscle. 

3. The contraction of the striped muscle-fibre is probably caused 
by the active contraction of the longitudinal fibrils of the intracellular 
network ; the transverse networks appear to be passively elastic, and 
by their elastic rebound cause the muscle to rapidly resume its 
relaxed condition when the longitudinal fibrils have ceased to 
contract ; they are possibly also paths for the nervous impulse. 

4. In some cases where muscle has been hitherto described as 
striped, but gives no appearance of the network on treatment with 
the gold and other methods, the apparent striation is due to optical 
effect: caused by a corrugated outline in the fibre. 

5. In muscles which do not perform rapid movements, but whose 
contraction is comparatively slow and peristaltic in nature, this 
peculiar network is not developed. In most if not all of the 


NOTE BY THE TRANSLATOR. 433 


unstriped muscles of invertebrates there does not appear to be an 
intracellular network present in any form, but in the unstriped 
muscle of vertebrates there are longitudinal fibres only; these 
possibly represent a form of network intermediate between the 
typical irregular intracellular network of other cells and the highly 
modified network of striped muscle. 

6. The cardiac muscle-cells contain a network similar to that of 
ordinary striped muscle. 


DESCRIPTION OF THE FIGURES ON PLATE II. 


Fig. 180 (p. 278). 


I. Preparation of the mucous membrane of the dorsal surface of the mouth and oesophagus to show 
the vascular supply. Arteries red, veins blue ; after Schobl. 
II. Small portion of the above to show the dilatations on the capillaries ; after Schébl, 


Fig. 187 (p. 285). 


Transverse section through the mucous membrane of the fundus of the stomach of Rana esculenta. 
Alcohol preparation, doubly stained with carmine and anilin blue. After Biedermann. 
(Oc. II, Syst. 7, Hartnack.) 


Fig. 196 (p. 298). 
I. Partial injection of the liver from the portal vein (blue): Rana esculenta.—G. H. 
II. Partial injection of the liver from the hepatic vein (red): Rana esculenta.—G. H. 
III. Complete injection of the liver from the hepatic artery (red) and from the portal vein (blue) : 
Rana esculenta.—G. H. 

A Portal (interlobular) veins and their branches. 
B Hepatic (intralobular) veins and their branches. 
C Hepatic arteries and their branches. 


Fig. 208 (p. 318). 
Two sections from the lung of Rana temporaria ; stained with borax-carmine,—G, H. 
I. The lung dilated (Hartnack, Oc. I, Syst. 3). 
IT. The lung contracted (Hartnack, Oc. I, Syst. 7). 


A Band of muscle cut transversely. 
B Band of muscle cut longitudinally. 
C Muscular layer of surface. 


Fig. 217 (p. 334). , 
Portions of two transverse vertical sections through the kidney.—G. H. 


I. Kidney of Rana esculenta, partial injection of the uriniferous tubes with silver nitrate (Hartnack, 
Oc. I, Syst. 7). 
II, Kidney of Rana temporaria, stained with borax-carmine (Hartnack, Oc. I, Syst. 7). 


Fig. 219 (p. 337): 
Two portions from a gold preparation of the kidney of Rana esculenta.—G. H. 


I. Showing the tendency to split into lobules, 
II, Nerve-fibres accompanying the blood vessels. 


a Blood-vessels, b Nerves. 


ARR ND'LX 


I. WORKS WHICH DESCRIBE ORGANS OR SETS OF 
ORGANS IN THE FROG. 


Bettade, E., Sulle diverse forme delle R, temp. in Europa e più particolammente 
nell’ Italia. Venezia, 1885. 

Brehm, A. C., Illustriertes Thierleben, Hildburghausen, 1869. Vol. V. 

Burdon-Sanderson, Handbook for the Physiological Laboratory. London, 1873. 

Camerana, L., Recherches sur les variations de la R. esculenta et du Bufo viridis 
dans le bassin de la Méditerranée. Paris, 1883. 

Carus, C. G., Lehrbuch der vergleichenden Zootomie. 2nd Edit. Leipzig, 1834. 

Cepéde, Comte de la, Histoire naturelle des quadrupèdes ovipaires et des serpens. 
Paris, 1808, 

Dugès, Recherches anatomiques et physiologiques sur les Reptiles. Ext. des An- 
nales des Sciences naturelles, Paris, 1827, 

Duméril and Bibron, Erpétologie générale ou histoire complète des Reptiles. 
1836. 

Ecker, A., Icones physiologicae. Leipzig, 1851-1859. 

Fatio, V., Faune des vertébrés de la Suisse. Genève et Bâle, 1872. 

Gegenbaur, C., Grundzüge der vergl. Anatomie. Leipzig, 1870. 

Gegenbaur, C., Grundriss der vergl. Anatomie. Leipzig, 1878. 

Gerlach, Handbuch der Histologie. 1853-1854. 

Gesner, C., Historia Animalium. Liber I. 1551. 

Gesner, C., Icones Animalium. 1560. 

v. Griesheim, A., Ueber die Zahlenverhiltnisse der Geschlechter bei R. fusca. 
Pflüger’s Arch. f. d. ges. Physiol. 1881. Vol, XX VI, p. 3. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Vol. VI, Am- 
phibien. Leipzig, 1873-1878, 

Howes, G. B., An Atlas of Practical Elementary Biology. London, 1885. 

Huxley, T., Anatomy of the Vertebrated Animals. London, 1871. 

Huxley, T., Lectures on the Elements of Comparative Anatomy. 

Huxley, T., Article Amphibia, Encyclopaedia Britannica. IXth Edit. 1875. 

Klein, E., Beitrige zur Anatomie der ungeschwänzten Batrachier. Jahreshefte. 
Wiirttemberg, 1850, pp. 1-84. ; 

Klein, E., and Noble Smith, Atlas of Histology. London, 1879-1880. 

Kloezke, C. G., Dissertatio anatomica de Rana cornuta. Berolini, 1816. 

v. Kôlliker, A., Handbuch der Gewebelehre. 5th Edit. Leipzig, 1867. 

Kuhl, H., Beitriige zur Zoologie der Rana esculenta: in Beitr. z. Zool. Frankfurt 
a. M., 1820. 

Laurenti, J. N., Synopsis Reptilium. Viennae, 1768. 

Leydig, F., Lehrbuch der Histologie. Frankfurt a. M., 1857. 

Marshall, A. M., The Frog. 3rd Edit. London and Manchester, 1888. 

Mayer, A. F., Beitriige zu einer anatomischen Monographie der Rana pipa. Acad. 
Caes. Leop. Nov. Acta, 1825. Vol. XII, p. 527. 

Ff 2 


436 APPENDIX. 


Meckel, J., Beiträge zur vergleichenden Anatomie. Leipzig, 1811. 

Meckel, J., System der vergleichenden Anatomie. Halle, 1833. 

Mivart, St. Geo., On the Classification ofthe Anurous Batrachians. Proc. Zool. Soc. 
1869. 

Mivart, St. Geo., The Common Frog. London, 1874. 

Müller, J., Beiträge zur Anatomie und Naturgeschichte der Amphibien. Tiede- 
mann’s Zeitschr. 1831, p. 190. 

Müller, J., The Physiology of the Senses, etc. Translated by W. Baly. London, 
1848. 

Owen, R., Anatomy of the Vertebrates. London, 1866. 

Ranvier, L., Lecons d’anatomie générale. Paris, 1880. 

Rôsel v. Rosenhof, Historia naturalis ranarum nostratium. Nürnberg, 1758. 

Rudolphi and Breyer, Observationes anatomicae circa abricam Ranae pipae. 
Berolini, 1811. 

Rusconi, M., Développement de la grenouille commune. Milan, 1826. 

Schneider, J. G., Historia amphibiorum. Jenae, 1799. 

Schwalbe, G., Lehrbuch der Anatomie der Sinnesorgane. Erlangen, 1885. 

Stannius, H., Zootomie der Amphibien (Handb. der Zoot. der Wirbelthiere, 2 Buch). 
2nd Edit. Berlin, 1856. 

Stricker, S., Beitriige zur Biologie der Batrachier. Wien. Zool. Bot. Verhandl. 
1866. Vol. XVI, pp. 451-456. 

Stricker, S., Handbuch der Gewebelehre. 

Stricker, S., Manual of Human and Comparative Histology. Translated by 
H. Power. London, 1870. 

Swammerdam, J., Biblia Naturae Amstelodamensis. (Dutch and Latin by 
Gaubius. Leidae, 1738.) 

Todd and Bowman, The Physiological Anatomy and Physiology of Man. London, 
1845-1857. 

Vogt, C., Zoologische Briefe. Frankfurt a. M., 1851. 

Wagler, J., Natürliches System der Amphibien. München, Stuttgart, and Tü- 
bingen, 1830. 

Wagner, R., Lehrbuch der vergleichenden Anatomie. Leipzig, 1834-1835. 

Wagner, R., Icones Zootomicae. Leipzig, 1841. 

Wagner, R., Handworterbuch der Physiologie. 1842. 

Waters, W. H., Histological Notes. Manchester and London, 1884. 

Wiedersheim, R., Lehrbuch der vergleichenden Anatomie der Wirbelthiere. 2nd 
Edit. Jena, 1886. 

Wiedersheim, R., Elements of Comparative Anatomy of Vertebrates. Translated 
by N. Newton Parker. London, 1886. 


Il. WORKS RELATING TO THE EMBRYOLOGY AND 
DEVELOPMENT OF THE FROG, 


Balfour, F. M. Treatise on Comparative Embryology. London, 1880. 
Born, G., Beitrige zur Bastardirung zwischen den einheimischen Anurenarten. 
Pfliiger’s Arch. f. d. ges. Physiol. 1883. Vol. XXXII, p. 453. 


APPENDIX. 437 


Durham, H. E., Note on the presence of a Neurenteric Canal in Rana. Quart. 
Journ. Micros. Sci. 1886. Vol. XX VI, p. 500. 

Giles, A. E., The development of the fat-bodiesin Rana temporaria. Quart. Journ. 
Micros. Sci. 1888. Vol. XXIX. 

Goette, A., Kurze Mittheilungen aus der Entwicklungsgeschichte der Unke. Arch. 
f. mik. Anat. 1873. Vol. IX, p. 396. 

Goette, A., Entwicklungsgeschichte der Unke. Leipzig, 1875. 

Hertwig, O., Die Entwicklung des mittleren Keimblattes der Wirbelthiere. Jena, 
1883. 

Johnson, A., and Sheldon, L., Notes on the Development of the Newt (Triton 
cristatus). Quart. Journ. Micros. Sci. 1886. Vol. XXVI, p. 573. 

Marshall, A. M., The Frog: An Introduction to Anatomy, Histology, and Embryo- 
logy. 3rd Edition. Manchester and London, 1888. 

Pflüger, E., Einige Beobachtungen zur Frage über die das Geschlecht bestimmenden 
Ursachen. Pflüger’s Arch. f. d. ges. Physiol. 1881. Vol. XX VI. 

Pfliger, E., Hat die Concentration des Samens einen Einfluss auf das Geschlecht ? 
Pfliiger’s Arch. f. d. ges. Physiol. 1883. Vol. XXIX, p. I. 
Pflüger, E., Zusammenstellung der Ergebnisse und Erérterung der Principien der 
Zeugung. Pfliiger’s Arch. f. d. ges. Physiol. 1883. Vol. XXXII, p. 542. 
Pflüger, E., and Smith, W. J., Experimente über Bastardirung der anuren Batra- 
chier. Pflüger’s Arch. f. d. ges. Physiol. 1883. Vol. XXXII, p. 519. 

Remak, Untersuchungen über die Entwickelung der Wirbelthiere. Berlin, 1855. 

Schultze, O., Zur ersten Entwickelung des braunen Grasfrosches. Leipzig, 1887. 

Schultze, O., Die Entwicklung der Keïmblätter und der Chorda dorsalis von Rana 
fusca. Zeitschr. f. wiss. Zool. 1888. Vol. XLVII, p. 325. 

Spencer, W. B., Some Notes on the Early Development of Rana temporaria. 
Quart. Journ, Micros. Sci. 1885. (Supplement.) 

Stricker, S., Untersuchungen über die Entwicklung des Kopfes der Batrachier. 
Arch. f, Anat. u. Physiol. 1864, p. 52. 

Torok, A., Beiträge zur Kenntniss der ersten Anlagen der Sinnesorgane und der 
primären Schädelformation bei den Batrachiern. Moleschott’s Untersu- 
chungen, 1870. Vol. X, p. 338. 


ME ADDITIONS TO: THE, LISTS, (GIVEN AT HE 
HEADS OF THE SECTIONS. 


1. Tue Bones. 


Albrecht, P., Note sur le basi-occipital des batraciens anoures. Extr. d. Bullet. d. 
Musée royal d’hist. nat. de Belgique. 1883. Vol. IT. 

Born, G., Die sechste Zehe der Anuren. Morphol. Jahrb. 1876. Vol. I. 

Born, G., Ueber das Skelet des Fersenhéckers von Rana fusca, etc. Sitzungsb. d. 
Schles. Gesell. f. vaterländ. Cultur, 1879. 

Born, G., Nachträge zu Carpus und Tarsus. Morph. Jahrb, 1880, Vol. VI. 

Ecker, A., Icones physiologicae. Leipzig, 1881-1889. 


438 APPENDIX. 


Ecker, A., Die Anatomie des Frosches. 2nd Edition. Braunschweig, 1888, 
pp: 17-62. 

Gegenbaur, Untersuchungen zur vergl. Anatomie der Wirbelsäule bei Reptilien 
und Amphibien. Leipzig, 1862. 

Gegenbaur, Grundzüge der vergl. Anatomie. Leipzig, 1870. 

Goette, A., Brustbein und Schultergiirtel auf entwickelungsgeschichtlicher Grund- 
lage verglichen bei Amphibien und Anurioten. Arch. f. mik. Anat. 1877. 
Vol. XIV, p. 502. 

Howes, G. B., On some abnormalities of the Frog’s vertebral column. Anat. Anz. 
1886. Vol. I, Pt. II. 

Leydig, F., Ueber den Bau der Zehen bei Batrachiern und die Bedeutung des Fer- 
senhôückers. Morphol. Jahrb. 1876. Vol. II. 

Parker, W. K., A monograph on the structure and development of the shoulder- 
girdle and sternum. Ray. Soc. 1867. ; 

Schneider, J. G., Historia amphibiorum. Jenâe, 1799. 

Stohr, P., Zur Entwickelungsgeschichte des Anurenschädels. Zeitschr. f. wiss. 
Zool. 1881. Vol. XXXVI. 

Torok, A., Beitrage zur Kenntniss der ersten Anlagen der Sinnesorgane und der 
primären Schiidelformation bei den Batrachiern. Moleschott’s Untersuchungen. 
1870, Vol. X, p. 338. 


2. Tue Musczes. 


Albrecht, P., Beitrag zur Morphologie des M. omohyoides und der ventralen inneren 
Interbranchial-Musculatur. Inaug. Dissert. Kiel, 1876. 

Ecker, A., Die Anatomie des Frosches. 2nd Edition. Braunschweig, 1888, 
pp. 65-139. 

Hoffmann, C. K., Bronn’s Klassen und Ordnungen des Thierreichs. Vol. VI. 
Amphibien. Leipzig, 1873-1878. 

Howes, G. B., An Atlas of Practical Elementary Biology. London, 1885. 


3. NERVOUS SYSTEM. 


Engelmann, T. W., Ueber die Discontinuität des Axencylinders und den fibrillaren 
Bau der Nervenfasern. Pfliiger’s Arch. f. d. ges. Physiol. 1880. Vol. XXII, 
ih fe 

- Grandry, Recherches sur la structure interne du cylindre de l’axe et des cellules ner- 
veuses. Bull. de Acad. Roy. du Belgique. 1868. 

Hodge, C. F., Some effects of stimulating ganglion-cells. (Some anatomical details 
regarding the relations of nerve-fibres with nerve-cells are given.) American 
Journ. of Phys. 1888. 

Owsjannikow, P., Ueber die Rinde des Grosshirns. Mémoires de l’acad. impé- 
riale des sciences de St. Pétersbourg. 1879. Series VII, Vol. XX VI, No. 11. 

Spiro, Physiologisch-topographische Untersuchungen am Riickenmark des Frosches. 
Mémoires de l’acad. impériale des sciences de St. Pétersbourg. 1870. Series VII, 
Vol. XVI, No. 7. 

Waldeyer, W., Untersuchungen über den Ursprung und Verlauf des Axencylinders. 
Henle u. Pfeuffer’s Zeitschr. 1864. Vol. XX, pp. 193-257. 

Consult also: Gerlach, J., Mayer, S., and Schultze, M., in Stricker’s Handbuch 
der Gewebelehre. 


APPENDIX. 439 


4. THE VASCULAR SYSTEM. 


Barthol, P., Sopra il sistema linfatico dei Rettili. Pavia, 1833. 

Blaschek, A., Untersuchungen über Herz, Pericard, Endocard, und Pericardhohle. 
Schenk’s Mitt. 1885. New Series, p. 32. 

Eberth, C. J., in Stricker’s Handbuch der Gewebelehre. 

Klein, E., On the peripheral distribution of non-medullated nerve-fibres (nerves of 
the blood-vessels in the frog’s tongue). Quart. Journ. Micros. Sci. 1872. 
Vol. XII, p. 123. 

Mayer, S., Studien zur Histologie und Physiologie des Blutgefässsystems. Wiener 
Sitzungsb. 1886. Vol. XCIII, Pt. ITT, p. 45. 

v. Recklinghausen, F., (The lymphatics) in Stricker’s Handbuch der Gewebelehre. 

Rollett, A., (The Blood) in Stricker’s Handbuch der Gewebelehre. 

Teichmann, L., Untersuchungen iiber das Saugadersystem. Leipzig, 1861. 


5. THE ALIMENTARY CANAL. 


Heidenhain, R., Beiträge zur Kenntniss des Pancreas. Pfliiger’s Arch. f. d. ges. 
Physiol. 1875. Vol. X, p. 557. 

Krause, W., Anatomische Untersuchungen (Tongue). Hannover, 1861. 

Consult also: Klein, E., The Oral Cavity.and the Oesophagus; Müller, W., The 
Spleen; Eberth, C. J., The Liver, in Stricker’s Handbuch der Gewebelehre. 


6. Tue Lunes AND Larynx. 


Holmgren, F., Methode zur Beobachtung des Kreislaufs in der Froschlunge. Beitr. 
z. Anat. u. Physiol. Festgabe f. C. Ludwig. Leipzig, 1874. 

Meckel, J. F., Beiträge zur Geschichte des Respirations-Systemes der Amphibien. 
Meckel’s Arch. 1849. Vol. V. 

Schmidt, C., De l’épithelium pulmonaire. 1866. 

Williams, Article Respiration, in Todd’s Cyclopaedia of Anat. and Physiol. 1859. 
Move 


7. THe URINo-GENITAL SYSTEM, THE ADRENALS, AND 
THE Far-Boptes. 


Aeby, C., Ueber glatte Muskelfasern im Ovarium und Mesovarium von Wirbel- 
thieren. Arch. f. Anat. u. Physiol. 1859, p. 675. 

Giles, A. E., The development of the fat-bodies in Rana temporaria. Quart. Journ. 
Micros. Sci. 1888. Vol. XXIX. 

Grohe, F., Ueber die Bewegung der Samenkôrper. Virchow’s Arch. 1865. 
Vol. XXXII, p. 416. 

Virchow, R., Ueber die Dotterplättchen bei den Fischen und Amphibien. Zeitschr. 
f. wiss. Zool. 1849. Vol. IV. 

Consult also: Eberth, C. J.; v. La Valette St. George; Ludwig, C.; Grun- 
wald ; Obersteiner, H.; and Stricker, S., in Stricker’s Handbuch der Ge- 
webelehre. 


440 APPENDIX. 


8. THE SKIN AND SENSE-ORGANS. 


a. The Skin. 


Busch, A., Phänomene aus dem Leben der Pigmentzellen. Arch. f. Anat. u. 
Physiol. 1856, p. 415. 


b. Special Organs of Tactile Sensation. 


Mitrophanow, P., Zur Entwicklungsgeschichte und Innervation der Nervenhiigel 
der Urodelenlarven. Biologisches Centralb. 1887, p. 174. 


c. The Organs of Taste. 


Beale, L. S., New Observations upon the Minute Anatomy of the Papillae of the 
Frog’s Tongue. Phil. Trans. 1865. Vol. CLV, p. 443. 

Engelmann, T. W., in Stricker’s Handbuch der Gewebelehre. 

Maddox, R. L., A Contribution to the Minute Anatomy of the Fungiform Papillae 
and terminal arrangement of Nerve to striped Muscular Tissue in the Tongue of 
the common Frog. Monthly Micros. Journ. 1869, p. f. 


d. The Kar. 


Albrecht, P., Sur la valeur morphologique de la trompe d’Eustache. Communica- 
tion faite à la Société d’ Anatomie Pathologique de Bruxelles. 1884. 

v. Kélliker, Handbuch der Gewebelehre. 5th Edit. Leipzig, 1867. 

Leydig, F., Handbuch der Histologie. Frankfurt a. M., 1857. 

Rüdinger, in Stricker’s Handbuch der Gewebelehre. 


e, The Nose. 


Marshall, A. M., Morphology of the Vertebrate Olfactory Organ. Quart. Journ. 
Micros. Sci. 1879. Vol. XIX, p. 330. - 


f. The Bye. 


Ciaccio, G. V., Beobachtungen über den inneren Bau des Glaskürpers im Auge des 
Menschen und der Wirbelthiere im Allgemeinen. Moleschott’s Untersu- 
chungen, 1870. Vol. X, p. 383. 

Hannover and Finkbeiner, Vergleichende Untersuchungen der Stärke des Glas- 
kôürpers bei den Wirbelthieren. Zeitschr. f. wiss, Zool. 1855. Vol. VI, p. 335. 

Hirschberg, J., Zur Dioptric und Ophthalmologie der Fish- und Amphibienaugen. 
Arch. f. Anat. u. Physiol. 1887, p. 493. 

Ranvier, L., Le mécanisme de la Sécrétion. Leçons faites au Collége de France 
en 1886-1887. (Nictitating membrane.) 

Consult also: Rollett and Stieda, in Stricker’s Handbuch der Gewebelehre. 


INDEX. 


Abducens nerve, p. 171. 


29 


nucleus, 146. 


Acetabulum, 48. 
Acromial, 39. 
Adrenals, 348. 
Ala magna, 25. 

» temporalis, 25. 
Alar cartilages, 28. 
Alimentary canal, 258. 
Ampulla anterior, 396. 


29 
29 


external, 398. 
posterior, 398. 


Angulo-splenial, 34. 
Ankle, 50. 
Anterior ampulla, 396. 


LE) 
22 
LE 


29 


brachial lymph-sac, 259. 
brachio-radial septum, 258. 
brachio-ulnar septum, 258. 
chamber, 409. 


Aorta dorsal, 233. 
Aponeurosis plantaris, 105. 
Arachnoid, 162. 


Arteria basillaris, 


163. 
bulbi, 222. 
circumflexa genu. lat. sup., 238. 
73 27 ” inf., 238. 
i » Med. sup., 238. 
HR Me eter 


comm. ant. 7 109. 
coraco-clavicularis, 231. 
costo-cervicalis, 231. 
cruris inf., 239. 

cut. calcaneï, 239. 

cut. fem. med., 237. 

M DOS 297: 

» pectoris, 231. 
haemorrhoid. inf., 236. 
lobi hemisph. inf. ext., 
is sup. int., 

>> Optici, 163. 
malleol. lat., 240. 
malleol. med., 240. 
pharyngo-maxill., 230. 
ramus auricularis, 228, 230. 
maxillaris comm., 228. 
inf, 2505 

5 5 sup., 228. 

»  orbito-nasalis, 228. 
scapularis post., 232. 

a sup., 232. 
spinalis ant., 163. 


163. 
163. 


7? 


27 


22 32 


Arteria subscapularis, 232. 
» Suralis, 230. 
Arteries, 222. 
72 of brain, 162. 
x of choroid, 411. 
oe of foot, 240. 
| D of hyaloid, 421. 
6 of iris, 41 2 
st of skin, 376 
of vitreous hoe 425 
Artery, ant. palatine, 224. 
ce » tibial, 230. 
>», brachial, 232. 
carotid, 224. 
ciliary, 226. 
5»  Coeliaco-mesenteric, 233. 
| 5, femoral, 236. 
» gastric, 233. 
:,  haemorrhoidal, 
» hepatic, 298. 
» hyaloid, 226. 
son dlines 235: 
internal carotid, 225. 
laryngeal, 226. 
», lingual, 224. 
» lumbar, 235. 
»» mesenteric, 234. 
occipital, 228. 
,,  occipito-vertebral, 226. 
,, oesophageal, 226. 
ophthalmic, 225, 411, 413. 
» peroneal, 231. 
» pharyngeal, 224. 
» post. palatine, 224. 
3 radial, 232. 
renal, 333. 
, sciatic, 236. 
, spermatic, 236. 
» subclavian, 231. 
» tibial, 238. 


235. 


ulnar, 233. 
urino-genital, 235. 
» vertebral, 226. 
vesico-epigastric, 235. 
Articular processes, 17. 
Articulations of vertebrae, 19- 
3 of atlas, 24. 
Arytenoid cartilages, 313. 
Astragalus, 50. 
Atlas, 18. 
Auditory nerve, 172. 


442 


Auditory nucleus, 144. 
Auerbach’s plexus, 292. 
Auricles, 214. 
Auriculo-ventricular valves, 216. 
Axillary septum, 258. 
Axis-cylinder, 202. 


Bidder’s ganglion, 220. 
Bile-ducts, 298. 
Bladder, gall-, 295, 299. 
oA urinary, 338. 
Blood, 262. 
Bones and joints, 13. 
Bowmawn’s glands, 387. 
Brachial nerve, 183. 
Brachio-ulnar lymph-sac, 259. 
43 radial 55 259. 
Brain, 141. 


Calcaneum, 50. 
Calcified cartilage, 15. 
Canales coccygei, 21. 
Canalis vertebralis, 20. 

» Yami ant. acustici, 393. 
Capitulum radii, 43. 

Capsule of labyrinth, 391. 

» Of lens, 413. 
Carotid arch, 222. 

ES gland, 223. 
Cartilage, calcified, 15. - 

5 of shoulder-girdle, 40. 

5: of skull, 29. 
Cartilages of larynx, 312. 

5 of nose, 27, 385. 
Cauda equina, 135, 189. 
Cava recto-vesicalis, 304. 
Cavitas sigmoidea maj., 43. 
Central canal of cord, 137. 

» group of cells, 139. 
Cerebellum, 148. 
Cerebral hemispheres, 156. 
Chamber, anterior, 409. 

oe posterior, 420. 
Chiasma, optic, 153, 155, 167. 
Chorda dorsalis, 20. 

Chordae tendineae, 216. 
Choroid coat, 409. 


Es plexus of fourth vent., 142, 164. 
153, 164. 


D third 
Ciliary nerves, 169. 

5» processes, 420. 
Cireulus iridis major, 413. 
Clavicle, 30. 

Cloaca, 347. 
Columella auris, 25, 390. 
Commissura anterior, 159. 
ay inferior, 140. 
% posterior, 159. 
43 superior, 140. 
a: transversa, 154. 


INDEX. 


Common bile-duct, 296. 

Cones, 418. 

Conus medullaris, 135. 

Coracoid, 39. 

Coracoid foramen, 39. 

Cornea, 406. 

Corpora quadrigemina, 152. 

Corpus callosum, 158, 159. 
» striatum, 158, 159. 

Corpuscles of blood, 263. 

on of Hassall, 321. 


Cranial nerves, 141, 167. 
Cranium, 23. 

Cricoid cartilage, 312. 
Crista acustica, 397. 

»  deltoidea, 41. 

» medialis, 42. 
Crusta petrosa, 279. 
Cupula terminalis, 398. 
Cutaneous glands, 372. 
Cuticula dentis, 279. 
Cutis, 369. 

Cystic duct, 295. 


Dentale, 35. 
Dentary, 34. 
Dentine, 279. 
Descemet’s membrane, 407. 
Dorsal lymph-sac, 255. 
», roots, 140. 
>» Septum, 252. 
Duct, common bile-, 296. 
» cystic, 295. 
Ductus choledocus, 296. 
»  endolymphaticus, 398. 
», fenestra ovalis, 394. 
», perilymphaticus, 395. 
,,  Wirsungianus, 301. 
Dura mater, 162. 


Ear, 389. 
Enamel, 279. 
Enlargements of cord, 133, 137. 
Epicoracoids, 37. 
Epidermis, 367. 
Epiglottis, 317. 
Episternum, 36. 


Exoccipitals, 23. 


Extrastapedial, 26, 390. 


Hye, 405. 
Eyelids, 422. 


Facial nerve, 171. 

Fat-bodies, 348. 

Femoral lymph-sac, 260. 
Fibrae arcuatae cerebelli, 149. 


Coverings of brain and cord, 162. 


Epithelium of ventricles, etc., 160. 


External limiting membrane, 420. 


Fibres of brain, 161. 
Filiform papillae, 380. 
Filum terminale, 135. 
Foramen condyloideum, 24. 


5 magnum, 23. 
. Monroi, 157. 
= ovale, 24. 


parietale, 156. 
rotundum, 392. 
Formatio reticularis, 140. 
Fossa condyloidea, 24. 

»,  tympanica, 24. 
Fourth ventricle, 142. 
Fronto-parietal bones, 26. 
Fungiform papillae, 380. 


Gall-bladder, 295, 299. 
Ganglia of bladder, 340. 
a of heart, 220. 

55 of spinal, 177. 

Ganglion ciliare, 168. 


5 condyloideum, 173. 

2 Gasserii, 168. 
ss interpedunculare, 152. 
35 layer, 415. 


nervi vagi, 173. 
Gasserian ganglion, 168. 
Glands, Bowman’s, 387. 

» cutaneous, 372. 

» gastric, 285. 

»  Harder’s, 424. 

>,  intermaxillary, 280. 

,,  Lieberkühn’s, 288. 

» nasal, 386. - 
oesophageal, 283. 


» of nictitating membrane, 423. 


periganglionic, 180. 
» thymus, 320. 
thyroid, 322. 
Glossopharyngeal nerve, 172. 
Goblet-cells, 289. 
Goll’s columns, 140. 
Grey matter, 139. 


Hair-cells of ear, 404. 

Fe of nose, 388. 
Harder’s glands, 424. 
Hassall’s corpuscles, 321. 
Heart, 213, 214. 

» endothelium, 320. 
» muscle, 216. 
nerves, 210. 
», Structure of, 216. 
Hepatic arteries, 421. 
»» portal system, 248. 
» veins, 297. 
Hip-joint, 49. 
Humerus, 41. 
Hyaloid artery, 421. 
membrane, 421. 


LE) 


22 


INDEX. 


| 


| 


443 


Hyoid, 35. 
Hypoglossal nerve, 182. 


Ilia, 47. 
Iliac lymph-sac, 257. 

» Septum, 253. 

Inferior femoral septum, 259. 
rps UMMLESIS 202: 

Infundibulum, 153. 

Inguinal septum, 254. 

Inner molecular layer, 415. 

» nuclear RATIO: 
Interfemoral lymph-sac, 260. 
Intermaxillary glands, 280. 
Intermediate fem. septum, 259. 
Internal ear, 391. 

Fe limiting membrane, 414, 420. 
muscles of eye, 413. 
Interstapedial, 25, 391. 
Intestine, 286. 
Intumescentia ant. and post., 135. 
Iris, 412. 
Ischia, 48. 


Kidney, 332. 
Knee-joint, 50. 


Labyrinth membranous, 395. 
osseous, 391. 
Be structure, 402. 
Lachrymal duct, 387. 
Lagena cochlea, 400. 
Lamina fusca, 411. 
»  suprachoroidea, 411. 
» terminalis, 153, 197. 
Large intestine, 292. 
Laryngeal nerve, 175. 
Larynx, 311. 
Lateral group of cells, 139. 
lymph-sac, 255. 
sense-organs, 370. 
») Sinus, 380. 
Lens, 413. 
Lieberkiihn’s glands, 288, 293. 
Ligament. calcanei, 19. 
su coronarium, 303, 
£ gastro-duodenale, 303. 
: hepato-duodenale, 287, 
305. 
> intercruralia, 19. 
interspinalia, 19. 
Se pectinatum iridis, 409. 
suspensor. hepatis, 304. 
os verteb. comm. ant., 19. 


post., 19. 


2 


22 
LE] 


295; 


22 29 


| Limiting membrane, external, 420. 


2 internal, 414, 420. 


| Lips, 275. 


Literature on adrenals, 330. 


444 


Literature on alimentary canal, 268. 
S 5, blood, 211. 
aa ,, blood-vessels, 205. 
», bones and joints, 13. 
» cartilage, 431. 
55 », connective tissues, 432. 
» ear, 356. 
Pe Er embryolog ry, 430-437. 
“5 » eye, 360. 
4; ,, fat-bodies, 330. 
ee » gall=bladder, 272. 
3 5, general, 435-436. 
» heart, 205. 
;, intestine, 270. 
, larynx, 309. 
, liver, 272. 
,, lungs, 300. 
», lymph, 211. 
, lymphatic system, 209. 
, mouth, 268. 
»» muscle structure, 427. 
5, muscles, 54. 


> »» hervous system, 122. 
>) 5» Nose, 357- 
DE >» pancreas, 272. 


a >, peritoneum, 274. 


% »» Tespiratory system, 300. 


5 » Skin, 353. 

$3 >, Spleen, 273. 

3 », taste-organs, 356. 
¥ », thymus, 310. 

FA >»; thyroid, 310. 

i » touch-organs, 356. 


Liver, 294. 
» Cells, 298. 
» pigment of, 299. 
» vessels of, 297. 
Lower eyelid, 422. 
» nasal glands, 386. 
Lungs, 317. 
Lymph, 264. 
Lymph-hearts, 261, 264. 
Lymph-sacs of ant. extremity, 258. 
ee » of hinder extremity, 250. 
5 >» Of trunk, 251, 255, 264. 
Lymphatic system, 251. 


Macula lutea, 419. 
Malpighian bodies of kidney, 334. 
is 5 of spleen, 303. 
Mandible, 34. 
Maxillary bones, 32. 
45 septum, 253. 
Meckel’s cartilage, 35. 
Mediostapedial, 25, 390. 
Medulla oblongata, 142. 
Medullary segments, 202. 
= sheath, 201. 
Medullated nerves, 201. 
Meissner’s plexus, 291. 


>» urino-genital system, 326. 


INDEX. 


Membrana choriocapillaris, 411. 

A limitans ext., 420. 

3 >»  int., 414, 420. 

x nictitans, 58, 422. 

DE suprachoroidea, 411. 
Membrane of Descemet, 407. 
Membranous labyrinth, 395. 
Mentomeckelian cartilage, 35. 
Mesocephalic ganglion, 168. 
Metacarpus, 46. 

Metatarsus, 52. 
Meynert’s fibres, 155. 
Molecular layer, inner, 415. 
»» Outer, 419. 
Motor- oculi, 167. 
Mouth, 275. 
Movements of hand, 46. 
Mucous glands of skin, 375. 
Miiller’s fibres, 420. 
Muscle, histology, 433. 
Muscles, 53. 
Muscles of abdomen, 67. 
», back, 71. 
5 e cloaca, 347. 
36 » eye, external, 55 
# oo: DINbELTIA LATE 
sf »» face, 59. 
* ,» foot, 105. 
59 5, forearm, 84. 
a ,, forelimb, 75. 
55 ,, hand, 87. 
co ,, hinder limb, 94. 
», hyoid, 64. 
ss », larynx, 315. 
7 ,, lower jaw, 60. 
, skin, me 
Muse. abduct. dig. I brev., 114. 
LE on OV 
” ” EB) long., gi. 
Ve 03% 
ns a yy) Vi brey.,.210, 
5 55 >, i longs) TO: 
& 3 » I ,, 86. 
» 5 ONE PTIM TO 
55 sr V secund., gl. 
5 hallucis, 109. 
»; Fe pollicis, 87. 
* 5 brev., 114. 
» adduct. brev., 100. 
5) 5 dig. I long., 100. 
” ” 3° II, 89. 
” ” ” V, 113. 
55 55 longus, 99. 
%) magnus, 99. 
BS PA pollicis, 87. 
»  anconaei, 87. . 
,  antibrachii lat., 85. 
med., 85. 
>) 9 prof., 85. 
5, biceps fem., 96. 
,;  coceygeo-cutaneus, 120. 
ag »  -iliacus, 74. 


” LE 


INDEX. 


Muse. coccygeo-sacralis, 73. 


compressor cloacae, 348. 
constrictor aditus laryngis, 315. 
constrictor iridis, 413. 
coraco-humeralis, 82. 

cucullaris, 71. 

cutaneus dorsi, 119. 

5 pectoris, 119. 
dilator aditus laryngis, 315. 
deitoideus, 82. 
depressor maxill. inf., 60. 

x palpebrae inf., 58. 
dilator iridis, 413. 

» Darium, 59. 
extensor brevis, 106. 
carpi ulnaris, 86. 


o cruris brevis, 104. 

> digit. I brev., 114. 
a 0: lon II 
> aoe Sle reves 


», long., 114. 
5 prop. brev., 92. 
39 CE) 5»  » long., 92. 
IT brev., 115. 
long. mals. 
>> prop., 03. 
IV, 116. 
», brev., 116, 
>> Prop.; 93- 
V brev., 115. 
,) long., 115. 


29 2 22 32 


5 dorsi comm., 73. 
flex. antibrach. lat. superf., 85. 
Bs Bs med. 85. 
5 > prof., 85. 
5  brev. digit. I, 100. 
545 SALES, VAST: 
” ” ” Vs 113. 


» carpi radialis, 84. 

35 » ulnaris, 84. 

,, digit. comm., 85, 87. 
LÉ ero Se 

II brev., 80. 

IT long., 88. 

II prop., 110. 

IT tert., 80. 

ITT brev., 89. 

., IIT long., 89. 

oA .. III prop., 111. 

WTS VV 107. 

IV brev., go. 

long., go. 

» eee: PLOp pula: 

V brev., 90. 

», long., go. 

A SN DEOP yo 13:6 Fe 

»  metacarp. digit. III, go. 

39 5, 5, IE go. 

»  metatars. digit. IT, 110. 

JOUR, aise 


29 29 


ss ,, 5, 


>» 52 2 


,, Comm. brev., gI. 
long., 87. 


445 


Muse. flex. metatars. digit. IV, 112. 


,, phal. prop. dig. ITT, 112. 
Mant, T9: 
» LV, post., 113. 
V0! 

” CE] ” 113. 

» tarsi ant., 104. 

8 75. POSt-y elena 
gastrocnemius, 102. 
genioglossus, 66, 281. 
geniohyoideus, 64. 

glutaeus, 94. 

hyo-arytenoideus anterior, 315. 
5 posterior, 315. 
hyoglossus, 66, 281. 
ilio-fibularis, 96. 
ilio-lumbaris, 74. 
ilio-psoas, 101. 
infraspinatus, 79. 
intercrurales, 75. 
interossei, 93, 113. 

5 dorsales, 116. 
interscapularis, 78. 
intertransversar, Cap. sup., 75. 

,) ») ” inf., 75: 

6 5 dorsi, 75. 
lateralis narium, 60. 
latissimus dorsi, 72. 
levator ang. scap., 76. 

a DULL 57. 
longissimus dorsi, 72. 
lumbricales, 108. 
masseter, 62. 
nasalis ext., 60. 
obliquus ext., 67 

5 inf., 56. 

be int., 67. 

sy sup., 50. 
obturat., 182. 
omohyoideus, 65. 
opponens dig. I, 110. 

II, 80. 

” » V, 90. 
palmaris brev., 87. 
pectineus, 100. 
pectoralis, 80. 
petrohyoïdeus ant., 65. 
petrohyoidei post., 66, 315. 
plantaris, 107. 
protrahens scap., 76. 
pterygoideus, 61. 
pyriformis, 95. 
quadratus fem., 112. 
rectus abdom., 67. 

» extern. bulbi, 55. 

», fem. ant., 95. 

ye RIDIER amen 

D UNE VUE 

», intern, maior, 97. 

» Super. ant., 56. 

» intern. minor, 98. 
retractor bulbi, 56. 


39 DE > 
DE) 9 ” 


” », PE] 


99 2 


446 


Muse. sartorius, 97. 
» Semimembranosus, 97. 
5, semitendinosus, 100. 
5, sphincter ani, 347. 
,,  sternohyoideus, 64. 
,. Sternomastoideus, 76. 
5,  sternoradialis, 82. 
submaxillaris, 62. 
,,  submentalis, 63. 
» subscapularis, 78. 
., temporalis, 61. 
tibialis ant., 104. 
post., 103. 


CE] 5, 


transverso-scapularis maior, 77. 
minor, 77. 


LE] LE) 
transversus metacarp., 03. 
e 5 plant., 108. 
,, triceps femoris, 95. 
vastus ext., 96. 
Int 00: 


Nasal bones, 33. 

» cartilages, 385. 

» glands, 403. 
Nephrostomes, 336. 
Nerve, abducens, 171. 

», auditory, 172. 

», brachial, 183. 
 MOACIAL, FL 
fifth spinal, 187. 
fourth spinal, 188. 
glossopharyngeal, 172. 
hypoglossal, 182. 
. laryngeal, 175. 
;, oculo-motor, 167. 
, olfactory, 167. 
5, optic, 167, 405. 
», pathetic, 142, 168. 
» palatine, 160. 
5» peroneal, 195. 
;:; pneumogastric, 173. 
3, radial, 180. 
» sixth spinal, 188. 
> Spinal, 175. 
», structure of, 201. 
5» sympathetic, 197. 
» third spinal, 188. 
>, tibial trigeminal, 168. 
vagus, 173. 
Nerves, 167. 
» of Cornea, 408. 
»» Car, 493: 
5, heart, 219. 
lungs, 319. 
oesophagus, 286. 
y skin, 378. 
», stomach, 286. 
Nervi ciliares, 169. 
Nervus coccygeus, 189. 
,,  coraco-clavicularis, 183. 
»  cruralis, 189. 


” ” 


bP) 2 


INDEX. 


Nervus cut. antibrach. inf., 185. 
cut. antibrach. sup., 185. 
cut. dorsi pedis lat., 196. 
»  ileo-hypogastricus, 189. 
;;  peroneus, 195. 
comm. inf., 196. 
lateralis, 196. 
Ns -f medialis, 196. 
ramus accessorius, 174. 
anterior, 173: 
auricularis, 172. 
cardiacus, 175. 
me , Cut. axillaris, 183. 
») ..  cutaneus dorx., 174. 


ss ,, 


LE) LE] 


” 5, 


9 cruris lat., 196. 
x De Hp »  med., 194. 
5 3 5» post., 194. 
2 A x fem., 180. 
5 “ lat., 187. 
3» med., 186. 
sup., 186. 


+ i dorsalis, 185. 
gastricus, 175. 
»  hyoideus, 172. 
hyomandibularis, 172. 
laryngeus, 175. 
lateralis, 185. 
mandibularis, 170. 
maxillaris, 170. 
maxillo-mandibularis,170. 
$ » muscularis, 187. 
.»  ophthalmicus, 169. 
,  palatinus, 171. 
;,  pectoralis, 185. 
“3 5 posterior, 173. 
5 ,  pulmonalis, 175. 
» scapularis, 174. 
subscapularis, 185. 
re ,,  ulnaris lat., 186. 
5) = med., 185. 
¥ tibialis, 194, 195. 
Neurilemma, 201. 
Nictitating membrane, 422. 
Non-medullated fibres, 202. 
Nose, 383. 
>» Skeleton, 27, 383, 385. 
Nuclear layer, inner, 416. 
» outer, 416. 
Nucleus abducens, 146. 
5 auditory, 144. 
Fa centralis, 144. 
» magnus, 147, 152. 
+ medullae oblongatae, 144. 
pheumogastric, 146. 
= trigeminal, 145. 


Oculo-motor nerve, 167. 
% nucleus, 151. 
Oesophageal glands, 283. 
Oesophagus, 282. 
Olfactory nerve, 167. 


INDEX. 447 


Omosternum, 36. 
Operculo-angulare, 35. 
Operculum, 25. 

Optic chiasma, 153, 155, 167. 
commissure, 154. 

fibre layer, 414. 

lobes, 149. 

nerve, 167, 405. 
tracts, 152. 


” 


2 


» capitato-hamatum, 45. 
5, cuboideum, 51. 

» cuneiformia, 52. 

», en ceinture, 27. 

» lunatum, 44. ‘ 

» multangulum maius, 45. 


Os articulare, 35. | 
| 


minus, 45. 


= naviculare of foot, 51. 


S 


LE] 
 occipitale basilare, EE 


? 


, 


of hand, 45. 


superius, 23. 


pyramidale, 44. 


Ostium abdominale, 304, 345. 


Outer nuclear layer, 416. 
Ovaries, 344. 
Oviducts, 304, 345. 


Palatine artery, 224. 

bones, 33. 

nerves, 160. 
Pancreas, 300. 

Papilla acustica lagenae, 400. 
Papillae of skin, 370. 

of tongue, 380. 
Parasphenoid, 26. 

Pars basilaris cochleae, 400. 
commissuralis, 147, 152. 
media, 135. 

neglecta, 400. 
peduncularis, 143, 152. 
Partes condyloideae, 23. 


29 


22 


22 


22 
59 
2 
2 


Pathetic nerve, 142, 168. 
Pectoral lymph-sac, 255. 
septum, 253. 

Pelvis, 47. 


32 


Pericardium, 213. 
Periganglionie glands, 180. 
Perilymphatic space, 393. 
Perineal septum, 253. 
Peritoneum, 303. 
Phalanges of foot, 52. 


29 


Pia mater, 162. 
Pigment of cerebellum, 140. 


29 


of hand, 4%. 


cord, 141. 
hemispheres, 160. 
liver, 299. 

medulla, 148. 

optic lobes, 152. 
thalamencephalon, 155. 
skin, 730. 


Pigment-layer, 419. 
Pineal body, 155. 
Pituitary body, 154, 156. 
Plexus, Auerbach’s, 292. 

“6 lateralis, 165. 

»  Meissner’s, 291. 
Pneumogastric nerve, 146, 173. 

», nucleus, 146. 

Pons Varolii, 149. 
Portal systems, 247. 

5. Vem, 20 7 
Posterior chamber, 420. 
Pre-arytenoid cartilages, 314. 
Precoracoid, 40. 
Premaxillary bones, 33. 
Processes, articular, 17. 


Ap spinous, 17. 
Hp transverse, 17. 
Processus coracoideus, 40. 
FB coronoideus, mandible, 34. 
a 5 >»  radio-ulnar, 43. 


cs mastoideus, 24. 

2 zygomaticus, 30. 
Prootic bones, 24. 
Pterygoid bones, 31. 
Pubes, 49. 
Pulmo-cutaneous arch, 230. 
Pulp-cavity, 279. 
Purkinge’s cells, 148. 


Radio-ulnar, 43. 
Rami communicantes, 181, 199. 
Rana aquatica, 3. 

,, esculenta, 4. 

», flaviventris, 7. 

» gibbosa, 3. 

 LARNOXIA, 2: 

» oxyrhinus, 7, 9. 

, Tubeta, 3. 

temporaria, 7 7: 
Receptaculum seminis, 337. 
Recessus utriculi, 306. 
Remak’s ganglion, 220. 
Renal arteries, 333. 

»» portal vein, 332. 

» veins, 333. 
Reproductive organs, 341. 
Retina, 414. 

Retinal pigment, 419. 
Ritter’s fibres, 418. 

Rods and cones, 416. 

Roots of spinal nerves, 175. 
Round bundle, 154, 159. 


Saccus endolymphaticus, 395, 398. 
», fenestra ovalis, 395. 
5 perilymphatieus, 305. 
Sacrum, 10. 
Scapula, 37. 
Sciatic artery, 236. 
ieee Nerve; 102: 
», plexus, I91I. 


448 


Sclerotic coat, 405. 
Semicircular canal, ant., 396. 
2 2? » ext., 398. 
»  post., 398. 
Septa, of ‘lymph- -SACS, 252. 
Septum medium, 130. 
Serous glands of skin, 372. 
Shoulder-girdle, 37. 
PE] -joint, 42- 
Sinus, superior, 383. 
Sinus venosus, 214. 
Skeleton, 15. 
= of nose, 27, 383, 383. 
Skin, 367. 
Skull, 21. 
Small intestine, 286. 
Sphenethmoid, 27. 
Spinal cord, 135. 
» ganglia, 177. 
>:  nerves, 135, 175, 181. 
> roots of, 175 
Spinous processes, 17. 
Spleen, 302. 
Squamosal bones, 30. 
Sternum, 36. 
Styloid cartilage, 25. 
Submaxillary lymph-sac, 255. 
Substantia reticulosa, 138. 
Suleus longitud. inf., 135. 
= sup., 135. 
Superior sinus, 383. 
Supplemenial toe, 5, 47. 374. 
Supra-femoral lymph-sac, 260. 
ss Septum, 259. 
Suprascapula, 37- 
Suprastapedial, 26, 390. 
Suspensorium, 30. 
Sylvian aqueduct, 150. 
Sympathetic system, 197. 
Symphysis pubis, 48. 
Systemic arch, 226. 


Tactile sensation, organs, 377. 
Taste-organs, 380. 
Teeth, 278. 


Tegmentum vasculosum, 395, 402. 


Temporary papillae, 370. 
Testis, 341. 
Thalamencephalon, 153. 


Thalamus-tubercinereum strand, 


155; 159- 
Third ventricle, 153. 
Thymus gland, 320. 
Thyroid gland, 322. 
Tibio-femoral septum, 260, 
Tibio-fibula, 49. 
Toes, 5, 47; 374- 
Tongue, 280. 
Tonsils, 323. 
Touch-corpuscles, 379. 
» “Spots, 378. 


INDEX. 


Transverse processes, 17. 
Trigeminal nerve, 168. 

= nucleus, 145. 
Trochlear nerve, 168. 
Truncus arteriosus, 216. 
Tuberculus maius, 42. 
Tympanie membrane, 389. 

ring, 26. 

Tympanum, 389, 390. 


Upper nasal gland, 386. 
Ureters, 337. 
Urinary bladder, 338. 

> organs, 332. 
Uriniferous tubes, 334. 
Urino-genital system, 330. 
Urostyle, 21. 
Utricle, 396. 


Vagus, 173. 

Valvula cerebelli, 148, 

Vasa efferentia, 341. 
>» Yecta, 412, 413. 


Vein, anterior abdominal, 248. 


caval, 241. 
orbital, 245. 
5 tibial, 250. 
,; brachial, 246. 
». cardiac, 249. 
caval anterior, 241. 

:: posterior, 246. 
cutaneous, 244. 
dorso-lumbar, 248. 
external jugular, 241. 
facial, 245. 
femoral, 249. 

;» gastric, 249. 

.. haemorrhoidal, 249. 

>» hepatic, 247, 297. 
hepatic portal, 249. 
iliac, 247. 
innominate, 242. 
internal jugular, 243. 
intestinal, 249. 
jugular, external, 241. 

i internal, 243. 
lingual, 241. 
mandibular, 242. 
median orbital, 243. 
nasal, 245. 
ophthalmic, 412. 
orbital anterior, 245. 

median, 243. 
posterior, 245. 
ovarian, 247. 
oviducal, 248. 
portal, 297. 
posterior caval, 246. 
posterior orbital, 245. 


Vein, pulmonary, 241. 
» radial, 246. 
Fr Lelalp24i75 333) 
» renal portal, 332. 
»» Sciatic, 247, 250. 
» spermatic, 247. 
»» Splenic, 249. 
»  Subclavian, 244. 
», subscapular, 244. 
>, Ulnar, 246. 
», vertebral, 244. 

Veins, 241. 

Vena bulbi anterior, 222. 


39 >» superior, 412. 


D >» posterior, 222. 
»> Spinalis anterior, 164. 
Hs 55 posterior, 165. 


” 39 superior, 164. 
Ventral lymph-sac, 255. 


INDEX. 449 


Ventral nucleus, 155. 

» Septum, 252. 
Ventricle of heart, 215. 
Ventricles of brain, 153. 

55 of larynx, 316. 
Vertebrae, 16. 

5 structure of, 20. 
Vertebral column, 16. 
Vessels of brain, 162. 

» Of liver, 297. 
Vitreous body, 420. 
Vocal cords, 315. 

py SACR,1220: 
Vomerine teeth, 276. 
Vomers, 34. 


Webs, 5, 275. 
Wrist-joint, 45. 


END. 


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4 


ited IV SILA TIONS OF 
FOREIGN BIOLOGICAL MEMOIRS. 


I, 


The Physiology of Nerve, of Muscle, and of the 
Electrical Organ. Edited by J. BURDON-SANDERSON, MD. FRSS. 
L. & E., Waynflete Professor of Physiology in the University of Oxford. 
Medium 8vo., cloth, price 215. 


LE: 
The Anatomy of the Frog. By Dr. ALExXANDER Ecker, 


Professor in the University of Freiburg. Translated, with numerous 


Annotations and Additions, by GEORGE HasLaM, M.D.; and profusely 
Illustrated. 


III. 
Contributions to the History of the Physiology of 


the Nervous System. By Professor Conrap EckHARD. ‘Translated 
by Miss Enrrx PRANCE. In Preparation. 


IAE 
Essays upon Heredity and Kindred Biological 


Problems. By Dr. August WeisMAnx, Professor in the University of 
Freiburg-in-Breisgau, Authorised Translation edited by Epwarp B. 
Poutton, M.A., F.L.S., F.G.S., Tutor of Keble College, Lecturer in 
Natural Science, Jesus College, Oxford; SeELMAR ScHONLAND, Pu.D., 
Sub-Curator of the Fielding Herbarium in the University of Oxford; 
and ARTHUR E. Suarpuey, M.A., F.L.S., Fellow and Lecturer of Christ’s 
College, and Demonstrator of Comparative Anatomy in the University 
of Cambridge. Medium 8vo., cloth, price 16s. 


Orford 


AT THE CLARENDON PRESS 
LONDON: HENRY FROWDE 


OXFORD UNIVERSITY PRESS WAREHOUSE, AMEN CORNER, E.C, 


Wn 


Date Due 


APR 29 1968 


cen anni 


7 ro 


~ hatte: