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Be at he

IGURE OF THE SKELETON, SHOWING THE RELATIONS

EXTERNAL FORM OF WILD cAT AND F
NAL FORM.

OF THE LATTER TO THE EXTER

=>
,

mae CAT.

AN INTRODUCTION TO THE STUDY

BACKBONED ANIMALS
ESPECIALLY

MAMMALS.

+
Jae K 30 VN)

By Sr. GEORGE, MIVART, Pa Dy FBS.

WITH 200 ILLUSTRATIONS

NEW YORK
CHARLES SCRIBNER’S SONS
743 anD 745 BROADWAY
1881

L799 137
2fte

/§8 10

GIFT
FATHER G. RY°N

PREFACE

———~-———-

BioLtocy is the science which treats of all living
organisms, from Man to the lowest plant. No natural
science is at present more keenly pursued or with more
effect. The advances of Astronomy and Geology have
produced great changes in men’s minds during the last
three centuries: Biology is producing changes at least as
great, in the present age. So rapid has been its progress
that the Natural History of Animals and Plants needs to be
rewritten—the field of Nature being surveyed from a new
stand-point. Such a history may be written in two ways:
(1) Living beings may be treated as one whole, their
various powers and the more general facts as to their
organization being successively portrayed as they exist
in the whole series; or (2) one animal (or plant) may be
selected as a type and treated of in detail, other types,
successively more divergent in structure from the first,
being described afterwards.

In following the latter mode, we may either begin with
one of the most simply organised of living creatures and
gradually ascend to the highest and most complex in
structure; or we may commence with the latter, and
thence descend to the consideration of the lowest kinds of
animated beings.

Historically, it is the latter course which has been

vill PREFACE.

followed. The bodily structure most interesting to man,
his own, was the first studied (directly or indirectly), and
the names now given to different parts of the bodies of the
lower animals have been mainly derived from human
anatomy. The descending course is also that which
seems, on the whole, preferable, for thus, by commencing
with the class of animals to which man belongs, we may
proceed from the more or less known to the unknown, and
from that which is comparatively familiar, to that. — 18
strange and novel.

Having then chosen to begin the study of “Ane and
Plants with that class to which we belong, it might
perhaps be expected that Man himself would be chosen as
the type. But a fresh description of human anatomy is
not required, and would be comparatively useless to those
for whom this work is especially intended. For a satis-
factory study of animals (or of plants) can only be carried
on by their direct examination—the knowledge to be
obtained from reading being supplemented by dissection.
This, however, as regards man, can only be practised in
medical schools. Moreover, the human body is so large
that its dissection is very laborious, and it is a task
generally at first unpleasing to those who have no special
reason for undertaking it. But this work is intended for
persons who are interested in zoology, and especially im
the zoology of beasts, birds, reptiles, and fishes, and not
merely for those concerned in studies proper to the medical
profession. |

The problem then has been to select as a type for
examination and comparison, an animal easily obtained and
of convenient size; one belonging to man’s class and one
not so different from him in structure but that comparisons
between it and him (as to limbs and other larger portions
of its frame) may readily suggest themselves to the

al Sa ea

ee

am sh argc” B

‘
=e

PREFACE. ix

student. Such an animal is the common Cat. In it we
have a convenient and readily accessible object for refer-
ence, while the advantages which would result from the
selection of Man as a type will almost all be obtained
without the disadvantages of that selection. The study
of the zoology of the Cat, as here treated, will also give the
earnest student of Biology the knowledge of anatomy,
physiology, and kindred sciences, which is necessary to
enable him to study profitably the whole class of animals
to which it belongs and to which we belong—the class of
Mammals. The natural history of that entire class will: be
treated of in a companion volume, to which the present
work may serve as an introduction—all the needful
anatomical terms and relations (as they exist in the selected
type) being here once for all explained. The present
volume is expressly intended to be an introduction to the
natural history of the whole group otf back-boned animals
(since they are all formed according to one fundamental
plan); but the subject has been so treated as to fit it also .
to serve as an introduction to Zoology generally, and even
to Biology itself: the main relations borne by cats, not
only to the leading groups of animals, but also to plants,
being -here pointed out. The sciences subordinate to
Biology are also enumerated and defined. |

It has been thought better not to separate the study of
physiology from that of anatomy, and, accordingly, an
explanation of the functions performed by each different
system of parts of which the body is made up, will be
found to follow the account of their structure.

Iam indebted to my friend Professor Flower for the use
of his valuable illustrations of the skulls of the Carnivora,
as also to the Zoological Society, from whose Proceedings —
they are, with some other illustrations, extracted. I
desire also to express my thanks to Professor Allen

x PREFACE.

Thomson, M.D., F.R.S., and to Messrs. Longmans & Co.,
Messrs. Cassell & Co., and Messrs. Kegan Pant & Co., for
the use of various electros.

Dr. Murie, F.L.8., has had charge of many of the wood-
cuts, certain of which—representing ligaments, viscera,
and salivary glands—have been drawn from his dissections
and under his supervision.

I have to thank Mr. Alban Doran, who has made careful
dissections of the internal ear and portions of the generative
organs, and also Mr. P. Percival Whitcomb and my son
Mr. Frederick St. G. Mivart, for more or less assistance.
To Professor Cope I am much indebted for very kindly
sending me proofs of unpublished plates of American
fossils described and named by him.

I have also to express my obligation to Mr. Wm. Pearson
(of the College of Surgeons) for making some excellent
dissections, from which certain of the illustrations are
taken. Original drawings have also been made from
specimens preserved in the museum of the Royal College
of Surgeons and in the British Museum. The drawings
have (with the exception of six figures of fossil remains)
been executed by Mr. C. Berjeau and engraved by Mr.
Ferrier. I feel bound to express my sense of the skill
evinced in their execution.

m

INTRODUCTORY.

ECT. PAGE | SKCT.
1. The Cat as a domestic animal if 9. The sciences subordinate to
2. Its scientific interest 7) Biology—different kinds of
eras Wild Cat he 2 pmstomy,.
Biases othe Doiadstie Cat 3 | 10. Physiology and its cides
5. The Egyptian Cat 5 | = aie
6. The different breeds of the =s 5 eee = ¢

mestic Cat . : 5 | 13. Phylogeny
7. Habits g | 14. Order to be followed in this
8. In what the scientific seed of vou

CONTENTS.

—_—_}>-—

CHAPTER I.

the Cat consists .

Cat’s body . a

CHAPTER II.

THE CATS GENERAL FORM.

SECT.

1. The general construction and
symmetrical relations of the

OHONAMP LW

Cat’s body . dl

. The skeleton . : :
Connective tissue > ;
Cartilage : .

Bone a . .

The process of ceehestion.

. The growth of bone d
. The composition of the skeleton .
. The external skeleton F

. Chemical ecmioeition of ‘the

PAGE

THE SKIN AND ITS APPENDAGES.

SECT.

10.

Fi.
12.
13.
14.
15.
16.
17.
18.
19.
20.

The epidermis . :

The dermis . j .
The claws . : 4 :
The hair .

Mucous membrane
Epithelium and corium
Teeth : s :

The milk dentition .

Dental formula .

Minute composition of the dectli ‘

Their modes of formation.

PAGE
A

22
22
22
24
26
27
29
30
31
82

CHAPTER III.

THE SKELETON

SECT.

oe ae ee ee

10.
ale
i Us
13.
14.

15.
16.
17.
18,
19.

20.

. The endo-skeleton

. Its divisions and gabdividions
The backbone .

The parts of a vertebra
Vertebral categories .

The dorsal vertebrae

The lumbar vertebrze

The cervical vertebre .

. The axis.

The atlas

The sacrum

The caudal folsbres x ;
The vertebral series as a whole.

The ventral part of the spinal
skeleton . ; -

The sternum

The ribs .

The costal cartilages
The thorax as a whole

The ligaments and mobility of
the spinal column .

™he union of the axis and Aer sey

CONTENTS.

OF THE HEAD AND TRUNK.

PAGE
34

34
35
35
36
36

35. The palatine

36. The vomer : ;

37. The mandible . : woe

38. The hyoid p : i

39. The skull examined cclainae
internally, and in sections .

40, The ligaments of the skull a

4]

. The ligaments and mobility of

the thorax .

. The skull considered peneriliead
. The occipital bone -

. The parietal : :
. The frontal. ‘ 3 LN,
. The temporal . :
. The sphenoid . , Pal
. The ethmoid 2

. The maxillo-turbinal . ‘

. The maxilla . ‘ a
. The pre-maxilla . : °

. The malar

. The nasal

. The lachrymal.

. The cranial skeleton as a whole.

CHAPTER IV.

THE

SECT,

i.

The appendicular skeleton and
its divisions, and the bones of
the pectoral limb . p ‘

2. The scapula and clavicle . .,
8. The humerus .~ . a .
ae Cie rads us ‘
5. the dina. - . : . -
6. The carpus. fat Rie D7, te
7. The metacarpus
8. The phalanges . apa
9. The ligamentsof the pectoul limb
10. A general view of the pectoral
appendicular skeleton . .
11. The bones of the pelvic limb .
12. The os innominatum : .

PAGE

89
89
90

|, gaia

SKELETON OF THE LIMBS.

SECT,
13. The femur . tdaud\ te ike
14, The patella . ; : ;
155 Whe tibial: .. ; : Pein!
16. The fibula 3 ote F
The tarsus . P : 4a
18. The metatarsus
The phalanges.

ee
| 20.

21.

22.

23,

The penmionte of itis pelvis
limb . :

A general view ob the nie
appendicular skeleton

Comparisou of the pectoral and
pelvic parts of the apne
lar skeleton. 5

The joints . Shana bite

PAGE
107

109

110
112
113
115
116

116.
118

119
120

CONTENTS. xili

CHAPTER V.

THE CAT’S MUSCLES.

SECT. PAGE |
1. The muscles in general. - 124
¥. Muscular tissue . % a oat Looe
3. Its properties . , of 126
4. Different kinds of ae ae Sad FS
-5. Their actions . ‘ 5198
6. The classification of Solas. stile
7. Muscles of the head and neck . 131

SECT.

8.
ps
10.
par

12.

CHAPTER

PAGE
Muscles of the trunk and tail . 136
Muscles of the fore-limb . . 145
Muscles of the hind-limb . . 154

Comparison otf the muscles of the
fore and hind limbs. ov GS

Summary of the Cat’s myology . 164

VI.

THE CATS ALIMENTARY SYSTEM.

SECT. PAGE
1. In what alimentation consists . 165
2. Food and waste . : =, hes
3. Intussusception and aialgate . 166
4. Crystalloids and colloids . o7. IGF «|
5. Digestion . ; 167
6. Summary of the Gnuichtry

processes and organs. ae bi.

7. Mucus A Z : Poe GS
rae mouth 5. - a ee
9. The tongue. : az8. 5
10. The salivary glands sai een tee

SECT
L

2. The blood . : : it at EGS:
3. Lymph . : oa 85
4, The structure of the sient »;! $96
5. The structure of the veins nf 346
6. The capillaries . : ae Sg 1 TE
7. The lymphatics : : . 198
8. The heart . : ate. Se
9. The great blood-vessels . . 201
10. The divisions of the heart . . 201
11. The circulation : : . 203
12. The valves of the heart 19° wh gg

CHAPTER VII.

THE CAT’S ORGANS OF CIRCULATION.

y PAGE
The essential nature of the cir-
culating system and its com-
ponent parts p ‘ wiz

SECT. PAGE
11. The pharynx Z : ee:
12. The esophagus ‘ 175
13. The abdominal a ai ite
contents . : 176
14. The stomach . : : beads
| 15. The small intestine. . 180
_ 16. The cecum and large intestine . 182
17. The pancreas . : : 7, i183
18. The liver . ‘ : «adh ee
19. The peritoneum : : yi» 289
SECT. PAGE
13. The auricles and ventricles . -205
14. The course of the arteries . . 206
15. The aorta é L : .. 206
16. The carotid arteries . ee
17. The subclavian artery . . 209
18. The axillaryartery . 209
19. The thoracic and the abate
aorta . 5 : : 210
20. The iliac artery . : «Sige
21. The external iliac arteries . 213
22. The course of the veins a et ee
23. The portal system . 2 =. 2L6
24. The azygos vein . . athe eke
25. The lymphatics ‘ : oy ote

xiv CONTENTS.
CHAPTER VIII.
THE CAT’S ORGANS OF RESPIRATION AND SECRETION.

SEUT. PAGE | SECT PAGE
‘1. In what respiration consists 220 | 13. The supra-renal capsules . 237 .
2. The elimination of water and 14, The thyroid body 237

the generation of heat 222 | 15. The thymus 237
3. The trachea 223 | 16. Other ductless Asad e 237
4. The lungs . 224 | 17. The spleen : 238
5. The mechanism of feupitation 225 | 18. The mammary glands . 239
6. The larynx 226 | 19. Reproduction . 240
7. The voice . 229 | 20, he male generative oreane 7 241
8. Secretion, in what 5 eee . 230 | 21. The testis 243
9. Waste products 232 | 22. Its product : 245

10. The kidneys 232 | 23. The female generative oneiie 245

11. The ureters 235 | 24. The ovary . 248

12. The bladder 235 | 25. Its product 250

CHAPTER IX.
THE CAT’S NERVOUS SYSTEM AND ORGANS OF SENSE.

SECT. PAGE | SECT. PAGE
1. Preliminary view of the functions : 21. The sympathetic system 283

of the nervous system . 252 | 99 The organ of touch . 285
2. Sensation . 253 | 23, The organ of taste 285
3. The main divisions of fie nervous . 24. The organ of smell . 286

system 253 | 95. The organ of sight . 988
4, Nervous tissue 253 | 96. The organ of hearing - 295
5. Membranes of the cerebro- spinal 27. Analogies between the ear eae

axis es the eye . 308
6. The spinal cord or r my elon. - 257 | 28. The function of ne nervous
7. The brain . e . S| age system generally . c 304
8. The nerves : 269 | 929, Conditions of its exercise 307
9. The olfactory nerves . . 270 | 30. Thefunctions ofthespinalnerves. 307

10. The opticnerve - 270 | 31, The functions of the cranial

11. The third and fourth nerves 271 nerves 309

12. The fifth nerve . : » 271 | 82. The functions of Bie: gia ona 309

13. The sixth and seventh nerves 273 | 33. The functions of the medulla

14, The eighth nerve O74 oblongata . > . 310

15. The ninth, tenth, leventti ai 34. The functions of the pons vatnliiy

twelfth nerves 274 corpora es ec ima and

16. Summary of the cranial nerves 275 cerebellum . "if ae

17. The spinal nerves _ 276 eu The functions of the coveliette » peo

18. The brachial plexus and nerves 36. The functions of the eee a

of the fore-limb | 278 pies ay

19. The plexus and nerves of the 37. Sleep ; oki

hind-limb 281 | 38. External and interial senuaitind 313

. The nerves of the tail

283

CONTENTS.

CHAPTER X.

THE DEVELOPMENT OF

SECT.

1. What is meant by its develop-
ment .

2 Change in the ovum , seb tise
to impregnation

3. Actions of the spermatozoa

4. Yelk segmentation

5. First appearance of the en

wm

and the earlier stages of its
growth .

. Nutritive conditions and tohtek-

nal modifications .

- Development of the tissues .
. Of the axial skeleton

PAGE
317
317
318
318

320
326

329
332

THE CAT.

SEOT.

9.
10.
ie
12.
13.

14.
15.
i6.

WY,
| 18.

Of the skull

Its ossification
Development of the Berri
Of the muscles

Of the alimentary canal dad ra
appendages

Of the blood and vascular systeil

Of the lungs and adjacent parts .

Of the urinary and a
systems . ;

Of the nervous iia and organs
of sense 3

Summary and fenuls.

CHAPTER XI.

THE PSYCHOLOGY OF THE CAT.

. What the study of Psychology is
. The Cat’s psychical powers

. Language —its different kinds .
. Mental powers which are not

possessed by the Cat
All its powers are coordinated .

. Its hierarchy of functions
. Its principle of individuation
. This cannot be merely nervous

activity

. Certain anatomical and path

logical facts

. The Cat has cunsentience .

PAGE
365
366
371

372
374
374
375

376

377
378

SECT.

11. The relations of psychical and
physical phenomena

12. The meaning of the term
‘Psyche,’ or ‘Soul,* and the
question of the existence of
such an entity

13. Objections considered .

14.
15.
16.
ie
18.

The Cat not a mere automaton .
What the Cat in itself is .
Immaterial realities

Definitions

The bearing of Paychoos y on oa
velopment

CHAPTER XII.

DIFFERENT KINDS OF CATS.

SECT.

Be
2.
3.

What are
and ‘ varieties ?’ :

Morphological and princi a
species :

Zoological siethenbtoters

‘kinds,’ ‘species,’
,

PAGE
390

391
392

SECT.

4, The Lion, Tiger, ge and

Ounce

5. The Puma and hoe
6. The Clouded Tiger and Thibet

Tiger-cat ; the Spotted Cat,

AY

PAGE
335

338
339
341

341
345
349

350

355
864

PAGE

378

380
381
382
384
385
386

386

PAGE

392
397

Xvi

CHAPTER XII—continued.

PAGE |

SECT.
the Bay Cat, the Fishing Cat,
the Leopard-cat, the Wagati
and the Marbled Tiger-cat

7. The Serval, the Golden-haired
Cat, the Grey African Cat, and
the (Merealine Cat

8. The Ocelot, the Margay, Geot-
froy's Cat, the Ocelot-like
-Cat, the Yaguar ondi, the Eyra
and the Colocollo. ,

9. The Rusty-spotted Cat, the Chi-
nese Cat, the Small Cat, Jer-
don’s Cat, the Java Cat, the
bushy-tailed-red-spotted Cat,
the Small-eared Cat, the
Large-eared Cat, the Flat-
headed Cat and the Bornean
Bay Cat. ‘

10. The Egyptian Cat, the, Giaiubn
Wild Cat, the Indian Wild

398

406

408 |

413

CONTENTS.

SECT.

a

Cat, the Common Jungle Cat,
the Ornate Jungle Cat, the
Steppe Cat, Shaw’s Cat, the
Manul and the Pampas Cat .
The Northern Lynx, the Pardine
Lynx, the Thibet — and
the Caracal .

. The Common Cheetah aint the

Woolly Cheetah

. Review of living Cats

. Extinct Cats

. Machzrodus

. Hoplophoneus and Paddle

17. Nimravus and Dinictis

18. Archelurus — ‘

19. Pogonodon and Eusmilus

20. Fossils of uncertain nature,

and summary of fossil cat
genera :

CHAPTER XIII.

THE CAT'S PLACE IN NATURE.

SECT.

1. What is needed to be known in

order to answer the question
_ What isa Cat?” . :

2. The Cat's most general mor-
phological and Eevee
characters .

3. These distinguish - fam all

non-living beings.

4. An objection considered

5. The character of the Cat as a

; living being :

6. What is implied in saying ‘the

. Cat is an animal ”

7. The principles of
classification .

8. The various sub- gistonns of
animals

9. The character of thie Cat as a
backboned animal .

10. The provinces and classes of
backboned animals — espe-
cialiy the class of fishes

11. The characters by which the Cat
differs from all fishes

12. The class Batrachia of the pro-
vince Branchiata .

13. The characters by which the Cat
differs from all Batrachians
and from all Branchiata .

zoologi ea

PAGE

440

440

44]
442

445
445
449
450

454

455
458

459

460

SECT.

14.
15.

16.
Ty.

18.

UEe

The class Reptilia of the pro-
vince Monocondyla

The characters by which the Cat
‘differs from all Reptilia

The class Aves or Birds

The characters by which the Cat
differs from all birds, from all
Monocondyla, and from all
non-mammalian Vertebrata .

The sub-classes and orders of
the class Mammalia Boe

The characters by which the Cat
differs from the sub-classes
of Mammalia to which it does
not belong .

. The characters by which the Cat’s s

order differs-from the other
orders of placental mammals

. The sub-orders and families of

Carnivora

2. The characters of the Cat’ s os

order Ailuroidea .

. The families of the Cat’s boi

order

. The peculiarities of the Cat? sown

family—Felidze

. Position of the genus, Felis, fe

the Cat’s place peiae all
other creatures

419

424

427
430
431
432
433
435

436 ~

437

437

PAGE
461

462
462

465

466
469

471
474
475
481

486

489

ss li i> Sng thine inl Sinan _"

CONTENTS.

CHAPTER XIV.

THE CAT’S HEXICOLOGY.

SECT.

1. The various relations of living

creatures to their environment

2. The Felide and physical condi-
tions, such as warmth, light,
and moisture . :

3. The geography of the Felidae

4, Zoological geographical regions .

5, The relations of the Felide to
time . . . :

PAGE

494

494
495
497

SECT.

6. Certain
geology . ;

7. The paleontology of the Folide.

8. Non-feline mammalian remains
contemporary with or antece-
dent to fossil cats

9. The inter-relations between cats
and other living creatures

elementary facts of

501 | 10. The parasites of cats

CHAPTER XV.

THE PEDIGREE AND ORIGIN

1. Meaning of the Cat’s Luin 39)
and ‘ origin’ 2

2. No presert need to argue in
‘ favour of evolution

’ 3. Probability of the Cat’s “deston’
through viverrine ancestors .

4, The probable genetic relations
or phylogeny of the Hluroidea

5. The probable She of the
Carnivora

6. Primitive mammals pidbabiy ti
marsupial

7. Summary of the Cat’s pedis.

8. Premammalian ancestors un-

known
9. Different possible ireaes of erode
tion : .
10. What are ‘ anaes? “ genera,’
‘families,’ ‘orders,’ and
‘classes’ ? : -

PAGE

512
512
512
513
514

515
517

518

519

520

OF THE CAT.

SECT.
11. We have experience of the origin
of all of these. ene

12. What our experience should
lead us to expect as to the
origin of Cat species

We seem to have experience as to
the origin of life itself

Our experience as to modes
of origin

Necessity of the ai rs an in-
ternal force .

Psychogenesis.

The cause of Paychogenes :

Prototypal ideas

Science is a knowledge eee eenses
and a knowledge of all causes
is necessary for perfect science

Utility of the study of ‘types’.

13.
14.
15.

16.
Tf:
18.
19.

20.

Xvil

PAGE
501
502
503

508
509

yr

LIST OF ILLUSTRATIONS.

aS

External form of Wild Cat and figure of the skeleton, showing the relations

of the latter tothe external form . ; : : : . Frontispiece
FIG. PAGE
1. Muzzle of the cat, seen in front : Saad
2. A diagrammatic vertical section of the cat’s ae fate dea sae
riorly through the median plane - . 16
3. Connective, adipose, and elastic tissue 17
4. Hyaline cartilage and fibro- cartilage—greatly eniied! - 18
5. Vertical and horizontal sections of a my ae of thigh- bone—greatly
magnified : 19
6. Vertical section through the ete oo ‘of a Hae! =a Sanene ae
physes ‘ . : . , 20
7. Touch- -corpuscle anil Esgite fade 23
8. Section of a cat’s vibrissa ; : 24
9. Sole of the cat’s fore-paw, showing Te ae : 25
10. Similar view of the hind-paw ab.
11. Ciliated epithelium cells. From aan? s ee. ib.
12. The cat’s dentition > ° F 27
13. Milk dentition of the cat . - 30
14. Microscopic tooth structure . s+ roe
15. A fragment of enamel—grcatly ena From Quain’ s tee
after Kolliker . é : 32
16. Three views of fifth Paka qeecbes 37
17. Tenth and eleventh dorsal vertebre . ; 7 fs : 39
18. Three views of fifth lumbar vertebra . ; : - 40
19. Three views of fifth cervical vertebra. ‘ : 41
20. Five views of axis vertebra . : : : : : 42
21. Five views of atlas vertebra. : : : : : 43
22. Three views of sacrum . . : 45
23. Ventral aspect of vertebral Galen : : : : - - : 48
24. Skeleton of thorax, seen ventrally 49
25. First, sixth, and thirteenth ribs 51
26. Two views of intervertebral discs 53
27. Ligaments of axis and atlas . 55
28. Dorsal view of skull . . 56
29. Base of skull 58
30. Front view of skull 59
31. Occipital bone—two views “61
32. Interparietal bone—two views : : : : 62
‘33. Parietal bone—two views ; ; A : : . : : Gs
34. Frontal bone—two views . : ; 2 : : : : “baat elie
35. Temporal bone—two views, ; : : : : ‘ Sig) fer 1 OD

LIST OF ILLUSTRATIONS.

. Section of the temporal bone of a tiger. From Professor Flower’s paper

published in the Pro. Zool. Soc. 1869, p. 17 ¥ K E i Pit
37. Sphenoid bone—two views , : : : : .
38. The right maxilla, seen internally AG peter 2 : :
39. The premaxilla—two views. ‘ : : P t ¥ is
40. The malar bone—two views . 3 ‘ Pf : - A ; :
41, The nasal bone—three views . ‘ ‘ ; ;
42, The lachrymal bone—two views . “ 7 Z i
43. The palatine bone—three views
44, The mandible—inside View . : b
45. Ventral and side view of the os Weide oe bad fragt =

46. Side view of skull i i i i

47. Back view of skull . j S ; ‘

48, Outline vertical section of skull to chore sae aheles

49, Vertical section of skull, showing median ethmoid . a K

50. Vertical section of anterior half of skull to show nasal cavity and torial
sinus . ‘ : é : : : A : : :

51. Scapula, external oo : : : 7 A : ° . :

52. Scapula, seen internally and from belo, : : soe ote 9, ead

53. Humerus—four views : : . , i 2 ; :

54. Humerus—inner side . : ‘ : : :

55. Radius—four views . . a . ; : :

5€. Ulna—three views 5 4 Z ° :

57. Skeleton of fore-paw—its palin aoe s - ss 2 : F ‘

58. Skeleton of fore-paw—its dorsal aspect

59. Bones of middle digit

. Vertical section through the hee « the ate bed nae a rome cao

show epiphyses

. Ligaments of SEGnInee ins views i 5 k s
. Ligaments of elbow—two views r

63. Ligaments of digit—to show the Seetipeien of the retractile lage F
64. Pelvis—antero-ventral view : ; : : ‘ °

65. Os innominatum—outer view . é 5 - ; F ;
66. Os innominatum—seen from within

67. Femur—two views . : : .

68. Femur—four views : : ; ° 3 : .

69. Tibia and fibula—seen in rot A , : :

70, Tibia and fibula—seen posteriorly : : : :

71. Tibia seen within, proximally, and distally

72. Skeleton of hind-paw—plantar surface 2 : ° .

73. Skeleton of hind-paw—dorsal surface . ; 2 < .

74. Ligaments of knee-joint ; ; ; - . : :

75. Vertical section through knee-joint . : :

76. Muscular tissue . : : . : ° .

77. Muscles of right fore- saci , ‘s ; : ; . °

78. Muscles of sternum : AM . . sats
79. Muscles of ventral surface of eaae A : : ; é -

80. Extensor (dorsal) muscles of right fore-limb ‘ . . . °
81. Muscles of flexor (ventral) surface of right fore-limb . - y

82. Superficial muscles of outside of right thigh slianguta ‘ : :
83. Deep muscles and tendons of outside of right hind-limb, “oe

84. Muscles of inside of right thigh . ; A ‘ . . E

85. Flexor muscles of leg : " ; - ; 3 5 ’ :

86. Surtace of palate . ; y é , ; ; . . :

PAGE

67
68
7p
74

foe

LIST OF ILLUSTRATIONS.

. Dorsum of tongue. : : . ‘ , : as : ,
. Salivary glands . ‘ : : : ; . : ° y -

. Viscera in situ . 5 : : ; : . ° . eg se
. The stomach and lace

. Magnified vertical section of wall of eee souitols a uainis

91
Anatomy—after Kolliker
92. Two gastric glands, greatly fractal Grom nai s Natetase abies
Heidenhain :
93. Intestinal canal, from eames taekeyeads : , : : : :
94. Intestinal villiathree views : : - ; E i ‘ ay
95. Caecum—two views :
96. Liver seen from behind : : : : ; . aes
97. Magnified section of an Hepaies’ vein. From Quain’s Anatomy—after
Kiernan . : . p A ; : ; 5 ; :
98. Magnified section ia a portal canal. From Quain’s Anatomy—after
Kiernan ., ‘ : , : ‘ . ° : . ; eth
PeMmnUceromaclesn res Fe ok a a Shy Mele Ma lle Ore ee
100. Veins with their valves. From Quain’s Anatomy .
101. Diagram of a lymphatic gland. From Quain’s eared .
102. Sections of the heart. F ‘
103. Diagram of the adult circulation an idonsally e : : ,
104. Great blood-vessels ‘ ant,

. Vessels and certain viscera of abdominal eas :
: ee of larynx ;
. The larynx and glottis as seen ieee tail Siri, oe eth dommracied

and expanded . 5 . . :

. Diagram of different gland Foti Beant uae Anatomy ° :

109. The kidney, entire and in section

110. Diagram of a Malpighian body. From (ne s Aridi apie Kélliker .

111. Diagram of minute circulation of kidney. From Quain’s Anatomy—
afcer Bowman . . : . ° : ‘ ‘

112. The thymus and ae aiid : ‘ : : : : . -

113. The cat’s spleen . : . : : ; : . ° : ah

114. Mammary glands. : : : SN: : :

115. Male generative organs. 4 ‘ - : ‘

116. Diagram of testis. From Quain’s asin

117. Spermatozoa .

118. Section of cat’s ovary, forint qigcraiaeal rom Quai? 8 Aiasoniye Satter

Schron .

119. Another section, still more Se 2b oe Onaey S Aerecanine ater
Schron : . : :

120. The ovum . ° { : : : : °

123.
124.

125.
126.
127,

. Nerve fibres, “sah From Quain’s Anatomy—after Bidder and

Volkmann . =

. Ganglionic nerve-cells, exes magnified. From Quain’s Ap ae

after Valentin.

Brain of the cat in it eer eral on ‘the left Bae - the ae a ee
Sections of spinal cord, somewhat enlarged. From Quain and Sharpey
(Allen Thomson) . . F : : . : . : :
Lateral view of cat’s jseaailt ; : 4 ° - . : es
Upper surface of cat’s brain. : : : ‘

Upper part of cat’s brain—the feaapiaas maith aivnridaten to show
the corpora quadrigemina, From a specimen in the College of Surgeons
Museum ., - ‘ : : : ‘ : “ : : ee

LIST OF ILLUSTRATIONS.

xxii

FIG.

128. Base of the cat’s brain : : ; ; ° . .

129. Vertical, longitudinal section of the cabs pian "4 ; ‘ :

130. Cranial nerves . : : . : : : : . . .

131. Brachial plexus and nerves . ° : . ; . . °

132. Nerves of fore-paw . - . , : ° . ‘

133. Lumbar and sacral plexuses ond nerves . : . . . :

134. Vertical section of eye : ‘ : : : ; . ’ .

135. Diagram of retina . : : ; - :

136. The lens. From Quain’s Nentbaivenatine Arwetdl ev

137. Section through the internal ear . : . chat

138. Bony labyrinth and auditory ossicles. From specimens in the College of
Surgeons . ° : 2 : woke

139. Two rods of Corti feat magnified. ape Ouain Ss ete ‘ ee

140. Termination of auditory nerves. From Quain’s Anatomy—after Max
Schultze . C : : : : A : : .

141. Early stages of yelk Peereniarind 3 . - ae

142. Single ovum, more advanced and bisected. arbors Heckala ie Hyoluien
of Man” . . gt eae

143. Two ova, Bene incipient en af Rarnnutlon of Somme area. F

144. Section of germ area.’ From Heeckel’s “ Evolution of Man” , é

145, Three views from Bowe of the earliest stages of the embryo’s develagt
ment. From Quain’s Anatomy—after Bischoff. : : °

146.. More advanced embryo, seen from above, showing proto-vertebre. From
Quain’s Anatomy

147. Diagram representing fant anewene Saat of embryo at dimaeas
stages of development ; : °

148, Five diagrammatic views of the ae etapaen of ae amnion and allanten
From Heckel’s “ Evolution of Man ”’—after Kolliker .

149, Diagram of the placental connexion of the embryo with the neem

150. The embryo cat in the uterus in its membranes. From Owen’s . ©
Anatomy of Vertebrates—after Buffon and Daubenton . : : .2

151. Longitudinal section of an embryo. From Quain’s Anatomy . ate

152. Diagram of foetus, showing the visceral arches and budding limhs .

153. Lateral view of head of embryo pig, showing the visceral arches. From
Quain’s Anatomy—after Parker ‘ ; A : 7 : -

154. Ventral aspect of the same : : °

155. Longitudinal, vertical section rough SE a sonine ineigene ali-
mentary canal, &c. From Heckel’s “ Evolution of Man”—after Baer.

156. Diagram of the foetal arteries and veins . .. ° .

157. Diagram of the foetal circulation through the heart and rap : .

158. Diagram of the development of the generative organs. : :

159. Portion of ovary of kitten, showing first aevelopment of ovasuneaed
Foulis .

160. Diagram of the derelapment of ‘the ee ; , : , ot

161. Four figures of the brain of an embryo kitten. From Quain’s Anatomy,
—after Reichert . ; - ets ; : |

162. Development of the eye—from Quarta 8 Rarer

163. A Radiolarian (Dorataspis polyanastra)—greatly jonmnamell

164. The same, only partially ante from the Journal of ne
Linnean Society) ‘ ; ; : 5 tans

165. Skull of the Leopard—from Pep. Foal. fos,

166. The Ounce (Felis uncia)—from Mr. Elliot’s Maropsanieen :

167, Skull of the Ounce—from Pro. Zool. Soc. : ;

. The Clouded Tiger (/ macrocelis)

Cm

LIST OF ILLUSTRATIONS.

. Skull of the Clouded Tiger—from Pro. Zool. Soc. . : z °

170. The Fishing Cat (Ff. viverrina)—after Elliot sah ets ; (
171. Skull of Fishing Cat—from Pro, Zool. Soc. . . . ‘
172. Skull of the Leopard-Cat—from Pro. Zool. Soc. .

173. The Marbled Tiger-Cat (F. marmorata) . - :

174. Skull of Geoffroy’s Cat—from Pro. Zool. Soc.

. The Eyra (#". Hyra) . :

». The Rusty-spotted Cat (F/. Paley nosy tne Elliot

. The Flat-headed Cat (/ planiceps)—after Elliot . .

. Skull of Flat-headed Cat—from Pro. Zool. Soc.

. The Manul (/ Manul)—from a specimen in the British Minseaa 2 :
. The Northern Lynx, variety & maculata—from a specimen in the British

Museum .

. The Cheetah (C iced us Gee)

. The young Cheetah 5

3. Skull of Cheetah (De Blainville) .

. Skull of Macherodus smilodon (De ieioneyillle}

. Skull and teeth of Hoplophoneus oreodontis (Cope)

. Skull of Mimravus brachyops (Cope) :

. Skull of Dinictis cyclops (Cope) .

. Skull of Archelurus debilis (Cope) .

. Skull of Pogonodon platycopis (Cope) .

. Lower jaw and teeth of Husmilus bidentatus ,

. Skull of the Panda (Ailurus fulgens)—from the Pro. Fook, Baer
. Skull of the bear (U7'sus arctos)—from the Pro. Zool. Soc. .

. Basis cranii of the bear. From Professor Flower’s paper on the Te

vora, Pro. Zool. Soc.

. Vertical section of the tympanic eran of the pe ee peas

Flower’s paper .

. Skull of an Indian ne! (Walpes oe oe ete the eae Wonk, Soc. ;
. Basis cranii of wolf—from Professor Flower’s paper . .

. Section of auditory bulla of dog—from Professor Flower’s eee

. Skull and dentition of Paradoxurus Crossii—from Pro. Zool. Soc.

. Basis cranii of civet-—from Professor Flower’s paper. : : .
. Basis cranii of Paradoxure—from the same paper ., ; : alee
. Basis cranii of ichneumon—from the same paper

. Basis cranii of hyena—from the same paper . °

. External form of Cryptoprocta ; ; . °

. Skull of Cryptoprocta—atter Milnes Rdwands - : ses
. Basis cranii of Cryptoprocta—from Professor Flower’s paper : 1
. The pads of the feet of Cryptoprocta—after Milne-Edwards

. Basis cranii of tiger—from Professor Flower’s paper

. Section of tiger’s auditory bulla (Fig. 36 repeated) .

. Diagram of cat’s possible pedigree . Sn eiee :

486

487
488
518

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PB Cr AT.

CHAPTER I.
INTRODUCTORY.

§ 1. WuHerTHer it is the Cat or the Dog which is the most
domestic of all our domestic animals, is a question which may be
disputed. The greater intelligence and affection of the dog, cause
men generally to prefgmit to its rival. As the eager partner of our
sports, or the fg cwardin of house or homestead, it is of
especial value. Yet the cat is so largely self-supporting and so
useful an ally against unwelcome intruders, that it is the inmate
of a multitude of humble homes wherein the dog has no place.
The cat also is favoured by that half of the human race which
is the more concerned with domestic cares; for it is a home-loving
animal and one exceptionally clean and orderly in its habits, and
thus naturally commends itself to the good will of the thrifty
housewife.

Moreover, though it is generally much less demonstrative in its
affection than is the dog, yet cats differ as men do, and some in-
dividuals manifest strong feelings of regard for one or other members.
of the family wherein they make their homes.

Cats are even sometimes made use of to obtain food for their
owners, the latter availing themselves of the habit which cats have
of bringing home prey.*

_ The Domestic Cat is an animal so common and familiar that its

utility is sometimes apt to be lost sight of. To realise its usefulness
we must imagine ourselves in a land where no such an animal is
known, but where the annoying creatures upon which it preys shall
have multiplied with that rapidity natural to them. The familiar:
tale of Whittington may serve to illustrate what would be the effect of
its introduction into such a land. It has been calculated that a single
cat may devour twenty mice in one day; but this of course is by

* Thus, several rabbits will sometimes be brought home by a cat in a single day.
B

2 THE CAT. . - foHar. 1.

no means the limit of its powers of destruction. Its effect in putting
to flight the creatures it pursues, is again far in excess of its
destructive energy. Were every cat in England simultaneously
destroyed, the loss through the entailed increase of vermin would
be enormous.

§ 2. But however much this animal may deserve our esteem, or
win our admiration, by its shapely form and: graceful movements,
it certainly has very special claims on the attention of lovers of
biological science. For in the first place its organization, considered
absolutely in itself, is one of singular perfection, and the adaptation
of means to ends which it displays is truly admirable. If, however,
we compare its organization with that of other animals, we shall by
so doing not only gain a better appreciation of its structural per-
fections, but also become acquainted with a variety of relations
conveying useful lessons in anatomy, psychology,* and zoology, and
others referring to the past, the present, and even the future history
of this planet.

§ 3. The “Common” (domestic) Cat of our country, and indeed
of the continent also, is not the ‘Common Cat” of zoology. The
latter is of course the originally native cat—or wild cat. The
domestic and the wild cat may, however, for our present purpose, be
considered together, and, thus considered, the eyents of the last two
thousand years have strangely altered the dis&#bution of the cats of
this country.

That men dwell in cities, instead of in woods, is one effect of
civilization. A similar but greater change has been produced with
English cats by the same cause. For when Julius Cesar landed
here our forests were plentifully supplied with cats, while probably
not a single mouser existed in any British town or village. . The
word ‘‘cat”’ appears to be of Roman origin, being probably derived from
the Latin word catus, which word also seems to have been at the same
time the root of the Greek xatra, the old German name chazza, and of
the softened French form of the word, chat. The original derivation
of the name does not, however, appear to have been as yet ascertained.
It occurs in Anglo-Saxon writings with the spelling Catt.

It might be supposed that our present domestic cat is simply our
own ancient wild cat tamed; but had it been so and therefore been
easily procurable, it would not have been so highly valued as it was
even so late as a thousand years after the Roman invasion. But
though the domestic cat was thus rare, and therefore precious, the wild
cat continued to be common in England during the Middle Ages.
This is proved by the fact that its fur was then commonly used for
trimming dresses.

A canon, enacted in the year 1127, forbad any abbess or nun to
use more costly fur than that of lambs or cats, and the cat was an
object of chase in royal forests, as is shown by a license to hunt it of

* The word Psychology is here used in ; its proper sense as embracing Physiology
its wide and (as the author believes) in | within its scope.

CHAP. I.] INTRODUCTORY. 3
the date 1239, and by a similar charter given by Richard the Second
to the Abbot of Peterborough.

The Wild Cat is now (thanks to the destruction of our forests,
the introduction of fire-arms, and the over-zeal of game-keepers,)
extinct in England, and perhaps in Wales also, though it lived
here till within fifty, and im Wales till within twenty yearsago. In
Ireland it seems never to have existed, and the stories we read of
Trish wild cats probably refer to the progeny of domestic cats run
wild. This is the opinion of Dr. Hamilton, F.Z.S8., who has paid
great attention to this subject, and carefully collected and investigated
the evidence as to the existence of the wild cat in Ireland. In Scotland
it is still far from uncommon, and 1s especially frequent in Inverness,
Ross-shire, Sutherland, and on the west coast of the Highlands, where
the recent crease of rabbits (animals so useful to it as good food,)
seems to have occasioned some increase in the number of wild
eats. These animals exist also in Skye, but not in the Western
Isles.

On the continent the wild cat is found in Southern Russia, and
the adjacent parts of Asia, Turkey, Greece, Hungary, Germany,
Dalmatia, Spair’, Switzerland, and, though now very rare, France.*
It does not appear to exist in Norway or Sweden.

§ 4. Our Domestic Cat seems to have come to us (like our other
domestic animals) from the East, and is probably a descendant of
the old domestic cat of Egypt, which, as the granary of the ancient
world, might well have been the country in which the animal was
originally tamed. In the Egyptian Gallery of the British Museum
is an excellent painting of a tabby cat, which seems to be aiding a
man who is capturing birds. It is mentioned in inscriptions as early
as 1684 z.c., and it was certainly domesticated in Egypt thirteen
hundred years before Christ. The earliest known representation of
the cat as a domestic animal and pet, is at Leyden in a tablet of the
18th or 19th dynasty, wherein it appears seated under a chair.
In Egypt, it was an object of religious worship and the venerated
inmate of certain temples. The goddess Pasht or Bubastis, the
Goddess of Cats, was, under the Roman Empire, represented with a
cat’s head. A temple at Beni-Hassan, dedicated to her, is as old as
Thothmes IV. of the 18th dynasty, 1500 8.c.t Behind that temple

* One wild cat at the least has been
killed in France between 1815 and 1830.

t+ Dr. Birch has kindly informed me
that the earliest representation of the cat,
with which he is acquainted, the date of
which is certain, is on tomb No. 170
of the Berlin Museum, apparently of
about 1600 B.c. ; but that it also figures
on a tablet which from its style appears
to be two hundred years older--as part
of the name of a woman, ‘‘ Maiu” or
cat. It also appears in hunting scenes
of the 18th dynasty, and in rituals
written under that dynasty, but pro-

bably repetitions of a much earlier text.
It is mentioned in the 17th chapter of
the Ritual, and the coffins of the 11th
dynasty are inscribed with that chapter,
which, according to Lepsius, would carry
us back to about 2400 B.c. In a copy of
the Ritual of B.c. 1500, its 33rd chapter
has the text, ‘‘ thou hast eaten the rats
hateful to Ra (the Sun), and thou feedest
on the bones of the impure cat.” In
Egypt an animal, though sacred in one
city, might be regarded as impure in
another city.

B 2

4 THE CAT. [cHAP. I.

are pits containing a multitude of cat mummies. The cat was an
emblem of the sun to the Egyptians. Its eyes were supposed
to vary in appearance with the course of that luminary,* and
likewise to undergo a change each lunar month, on which account
the animal was also sacred to the moon. Herodotus (11. 66) re-
counts instances of the strangely exaggerated regard felt for it by the
dwellers on the Nile. He tells us that when a cat dies a natural
death in a house, the Egyptians shave off their eyebrows, and that
when a fire occurs they are more anxious to save their cats than to
extinguish the conflagration. :

From Egypt it must have been introduced into Greece, and the
intimate knowledge of Egyptian customs which became common in
Rome from the time of Julius and Augustus must have brought
into it amongst many other animals a knowledge of the domestic
cat. <A fresco painting of such a cat was discovered in Pompeii t

It was not a domestic animal amongst the Hebrews, though it was
known in India two thousand years ago.

It has been suggested by Professor Rolleston,t that the domestic
animal of the Greeks (used by them for the purposes for which we
now use the cat) was the white-breasted marten. But however
this may be, there can be no question as to the cat having been
domesticated in Europe before the Christian era. There are
signs that it was domesticated amongst the people of the Bronze
period, and the supposition that it was first introduced into Western
Europe by the Crusaders, is of course an altogether erroneous one.
They may however have introduced a distinct race, for if it be true
that our domestic cats have mainly descended from the Egyptian
cat, it does not foliow but that blood from other sources may have
mingled with that of the Egyptian breed.

Pope Gregory the Great, who lived towards the end of the sixth
century, is said to have had a pet cat, and cats were often immates
of nunneries in the Middle Ages. The great value set upon the
cat at this period is shown by the laws which in Wales, Switzerland,
and Saxony, and other European countries, imposed a heavy fine on
cat-killers. As compensation, a payment was required of as much
wheat as was needed to form a pile sufficient to cover over the body
of the animal to the tip of its tail, the tail being held up vertically,
with the cat’s muzzle resting on the ground.

The Witp Car (felis catus) differs from our ordinary domestic
cat in that if is more strongly built and larger, with a stouter head
and shorter and thicker tail, which is not tapering but of about the
same thickness throughout. Its whiskers also are more abundant,
and the soles of its feet are, in the males, deep black. Its body is
of a yellowish-grey colour, with a dark longitudinal mark along the

* Mr. J. Jenner Weir has found that | represented as seizing a thrush, and is
the eyes of cats will really change colour. | very well drawn.

t See Plate 81 of Raecolta de piu belli t See Cambridge Journal of Anatomy
Dipinti, from the collections in the Royal | and Physiology, 1868, vol. ii. pp. 47 and
Museum (Napoli, 1854). The cat is | 487.

CHAP. 1] INTRODUCTORY. 5

back, and with numerous darkish stripes descending more or less
vertically down the sides, and marking transversely the limbs. Its
tail is rmged with black, and is black at the end. It is thus marked
like the domestic variety called “tabby.” One killed near Cawdor
Castle measured 3 feet 9 inches from its nose to the end of its tail.*
Its savage disposition is very early shown, even the young kittens
spitting vigorously at anyone who approaches them. The female
makes her nest in hollow trees and the clefts of rocks, and sometimes
uses the deserted nest of some large bird. 3

§ 5. The Eeyprran Cart (Felis maniculata) is a native of northern
Africa, and was the parent of the cat tamed by the Egyptians, and
—if what has been here urged is correct—also of our own domestic
cat, possibly with an admixture of other blood.

The Egyptian cat is said to be about one-third smaller than the
European wild cat. It is of a yellowish colour, somewhat darker
on tke back and whitish on the belly. There are some obscure
stripes on the body, which become more distinct on the limbs. The
tail is more or less ringed towards its termination, which 1s
black.

§ 6. Although the differences between the various breeds of the
Domestic Car are small indeed compared with those between dif-
ferent races of dogs, still very distinct varieties exist, but their
distinctions repose mainly on the colour and the length or quality of
the fur, and not on differences of form, such as those we find
existing between the Greyhound and the Pug, the Spaniel and the
Mastiff. :

The colours of cats may be divided into black, white, tabby, sandy
tortoiseshell, dun, grey, and what is termed “‘ blue.’ There are also
cats in which these various colours are more or less mixed.

The grey cat is very rare. It is, in fact, a tabby, without the
black stripes, except two large stripes over the fore-legs—marks
present in most spotted or striped cat-lke animals of whatever
species. |

Black cats are remarkable for the clear yellow colour of their
eyes. Their coat is rarely entirely black, for there are generally
a few white hairs on the throat at the least. When young they
show more or less perceptible striped markings.

White cats may have blue eyes, or eyes of the ordinary colour—
that is, an obscure yellow with a tinge of green.

Those with blue eyes are generally deaf, but they are not always
so. It often happens that the eyes of a white cat are not alike in
colour ; thus one may be blue and the other yellow.

The late Mr. John Stuart Mill told my friend Mr. John Jenner
Werr, F.L.S.,+ that he had at Avignon a breed of cats the eyes of
which distinctly changed colour when the animals were excited.

Mr. Harrison Weir tells me that the {| at numerous cat shows, and I am in-
largest domestic cat he has seen weighed | debted to him for very kindly furnishing
twenty-three pounds. me with his notes respecting varieties of

+ This gentleman has acted as judge !} the domestic cat.

6 THE CAT.

[CHAP. I.

The tabby cat may be the result of the occasional crossing ot the
domestie cat by the wild cat. That they do breed together occasion-
ally is certain,* and indeed races of domestic cats of different parts
of the world will breed with wild cats of the same region.

The tortoiseshell cat should be fawn-coloured, mottled with black.
Cats thus marked are almost invariably females, while sandy-coloured
cats are almost always males. It appears that the sandy tom cat is
the male of the breed of which the tortoiseshell is the female—the
litters being almost invariably so divided. This fact is very interest-
ing, because the sexes of cat-like animals are similarly coloured.t

Sometimes, however, sandy cats are female, and there is at least
one good instance of a true tortoiseshell tom cat. Such cats, indeed,
have not unfrequently been offered, by letter, to the Secretary of the
Zoological Society, at very extravagant prices. Probably many of
them were male cats of three colours—such as white and tortoiseshell
and grey-white and sandy—but not the true tortoiseshell.

The Royal Siamese cat is of one uniform fawn colour, which may
be of a very dark tinge. There is a tendency to a darker colour
about the muzzle—as in pug dogs. It has also remarkable blue
eyes, and sometimes, at the least, two bald spots on the forehead.
It has a small head.

The blue or Carthusian cat is a breed with long, soft hair of a uniform,
dark greyish-blue tint, with black lips, and black soles to the paws.

The Angora, or Persian cat, is remarkable for its great size, and
for the length and delicacy or its hair, especially of the belly and
throat. Most commonly its coat is of a uniform white, yellowish
or greyish colour, while the soles of its paws and its lips are often
flesh-coloured. Its temperament is said to be sometimes exception-
ally lethargic; but this is certainly not always the case, and may
be due to excessive petting for generations. This breed is believed
by some naturalists to be descended from an Asiatic wild cat,t with
a shorter tail than that of the Egyptian cat. It is commonly re-
peated in works on Natural History that there is in China a breed
of cats with pendent ears; but the Pére David§ regards the
assertion as an absurd fable. He has repeatedly sought to find
such animals, but has never been able to see any, or to learn that
they existed. |

* This has been ascertained by Mr. A. | than that of the domestic animal.

H. Wills, who succeeded in getting the
wild and domestic cat to breed together
in confinement. (See Land and Water,
Sept. 4th, 1875 ; and the Zoologist for
1873, p. 3574 ; and for 1876, pp. 4867
and 5038.) Mr. S. C. B. Pusey has also
successfully crossed the wild and domestic
cat, and several kittens resulting from
this cross have been sent to the gardens of
the Zoological Society of London. This
interbreeding is remarkable, seeing that
the period of gestation of the wild cat is
sixty-eight days, or twelve days longer

+ The only exception I have met with
is the Yaguarondi of America, in which
species the female is said to be of a
lighter and brighter colour than the
male.

t{ Pallas says that cats like the Angora
cat are brought to Siberia from China.
Zoographia Russo-Asiatica, vol. i. p. 28,
note 3.

§ The well-known Lazarist missionary
and naturalist, who has made so many
interesting discoveries in China and
Thibet.

CHAP. I.] INTRODUCTORY. 7

In Pegu, Siam, and Burmah, there is a race of cats*—the Malay
Cat—with tails only of half the ordinary length, and often contorted
in a sort of knot, so that it cannot be straightened.t The true short-
tailed or tailless cat—the Manx Cat—has also the hind-legs relatively
long. Mr. J. J. Weir tells me he has seen one which had the fore-
legs so short as to be useless in walking, and the animal sat up like
a kangaroo.

Tailless cats are not, however, the only cats to be found in the
Isle of Man; some cats there have tails ten inches long,§ a fact
probably due to the introduction of long-tailed cats from England,
Scotland, or Ireland. In cross-breeding the progeny seem generally
to resemble the father as to length of the tail.|| A tailless breed of
eats also exists in-the Crimea. The Mombas Cat of the coast of
Africa is said to be § covered with short stiff hair instead of the
ordinary sort of hair. The Paraguay Cat** is but a fourth of the
average size of our domestic’cats, has a long body with short, shiny,
scanty hair, which lies close, especially on the tail. In South
‘America there is said to be also a race of cats which have ceased to
give forth cries like those by which our own cats are wont to give
expression to their emotional sensibility. It is to be wished that
this last breed should be introduced into this country. Yet the
breed would probably not persist, for the reason which seems to
limit the formation of new races; for the wandering nocturnal
habits of the species defeat most attempts at selection in breeding,

That variations which might serve for the formation of new breeds
must be every now and then forthcoming, is indicated by such facts
as the following one, for a knowledge of which I am indebted to Mr.
John Birkett.

A female cat had its tail so injured by the passage of a cart- wheel
over it, that her master judged it best to have her tail cut off near
the root. Since then she has had two litters of kittens, and in each
litter one or more of the kittens had stumps of tails, while their
brothers and sisters had tails of the usual length. Mr. Birkett
himself saw one of the stump-tailed kittens. It is of course pos-
sible that the mother had some trace of Manx blood in her, but it is
not likely, and the occurrence of the phenomenon just after, and
only after, the accident and amputation, seems to indicate that in
this perpetuation of an accidentally deformed condition, we have an
example of the origination of a new variety.

* See J. Crawford’s Descriptive Dic- | bones of the fore-limb are entirely want-

tionary of the Indian Islands, p. 255.

+ Its contortion is due to deformity of
the bones of the tail.

+ In the Museum of the Royal College
of Surgeons there is preserved the skele-
ton of a cat, formerly belonging to the
late Mr. Doubleday, the entomologist.
This cat was born without any fore-
limbs, yet could jump so well as to be
able to jump up on a table. All the

ing, save the shoulder-blades.

§ Mr. Bartlett assures me he has
measured cats’ tails in the island, and
found all lengths up to ten inches.

|| See Mr. Orton’s Physiology of Breed-
ing, 1855, p. 9.

“| See Captain Owen’s Narrative of
Voyages, vol. ii. p. 180.

** See Reugger’s Sdugethiere van Para-
guay, 1830, p. 212.

8 THE CAT. [cHAP. I.

The direct influence of external circumstances upon different kinds
of cats is worthy of note. Thus Captain Owen, R.N., (already re-
ferred to), tells of a cat which, having been taken to Mombas, “ under-
went a complete metamorphosis,” and ‘‘ parted with its sandy-coloured
fur’ after only eight weeks’ residence there. In Paraguay, again,
cats seem unable to become thoroughly feral as they do in other
places, and as other European animals do in Paraguay.

§ '7. The domestic cat begins to be ready to reproduce by the end of
the first year of her life, and she is prolific to her ninth. Her young
are carried for fifty-five or fifty-six days, and she generally has five
or six young at a birth, and sometimes eight or nine. In a wild
state the cat brings forth at least twice a year, but the domestic cat
will do so three or four times annually. The wild cat has only four
or five young in a litter. The length of life which cats attain varies
with individuals, and is a point difficult satisfactorily to ascertain.
It seems probable that about twelve years is its ordinary limit, but
in some cases the age of eighteen years may certainly be attained
under favourable circumstances.

Though smal! quadrupeds and birds are their natural prey, cats
are singularly fond of food which in a wild state they can never or
but seldom attain, namely, cow’s milk, and also fish. In spite also
of the relative obtuseness of their sense of smell, they are said to
show a marked preference for certain odours, a taste in harmony
with that luxurious and ease-loving nature with which they are
endowed.

§ 8. To know all about the history and habits of the cat, together
with the peculiarities of form and colour of its various breeds, both
wild and domestic, is not to have a scientific knowledge of the cat. ”
To know the animal scientifically, we must be able to answer cor-
rectly the question ‘‘ What is a cat?” But we cannot so answer
this question unless we know both the main facts as to the animal
considered in itself absolutely, and the various leading relations in
which it stands to all other creatures. ?

“We understand a particular kind of animated being, when
looking inwards we see how its parts constitute a system, and again
looking outwards and around, how this system stands with regard
to other types of organised existence.’ *

No object can be understood by itself. We comprehend anything
the better, the more we know of other things distinct from but related
to it.

The complete natural history of any animal, in the full and
proper sense of the term, is its Biology. It is so because, though
the study of any animal is of course mainly its zoology, yet
fully to understand certain of its powers, and the conditions
necessary for its existence, a side glance should be cast at the
vegetable world also; and Biology is the term which denotes the
science of all living creatures—both animals and plants—and there-

* Essays by James Martineau, Second Series, p. 417

CHAP, 1] INTRODUCTORY. 9

fore embraces within it both zoology and botany. Moreover, Biology
not only includes these two subordinate sciences, but also the various
inquiries which refer to the relations which exist between their
respective subject-matters.

Now, in the first place, the study of the cat, as of every living
ereature, may be followed up along two different lines of inquiry.
One of these refers to the structure of its body, the other refers to
the actions which its body performs; in other words, the animal

_may be considered statically or dynamically.

Before, however, considering these two kinds of inquiry, and
seeing what subordinate inquiries they respectively include, it may
be well to note that the cat’s body is obviously a complex structure,
consisting of distinct parts, which are also obviously put to different
uses, and reciprocally minister one to another. Thus, for example,
the limbs may more or less rapidly propel the body after prey which
the eyes guide the paws to grasp and bring to the teeth and jaws
by which it is divided to pass into the interior of the trunk, to be
there converted by the digestive organs into nutriment, by which
the limbs, the eyes, the paws, the teeth and jaws, stomach, intes-
tine, &c., are themselves supported and maintained in healthy
working condition. This animal’s body, then, 1s a complex whole in
which all the parts are reciprocally ends and means ; and such is the
definition of ‘‘ an ORGANISM,”’ wide as is the difference in complexity
between organisms, both animal and vegetable, of very different
kinds.

§ 9. The organism with which we are occupied, the cat’s body,
may, as has been already said, be considered as to its structure
and as to its actions. As to its structure it may be considered with
respect to its size, shape, consistency, the number, form, and relative
position of its various parts, and such study is called Anatomy. The
inquiry as to its form is called Morphology, and this mquiry may
be directed to its larger parts and grosser structures or to 1ts minute
structure.

The various parts of the cat’s body, such as its tongue, eyes,
stomach, kidneys, &c., are termed “ organs,” and these are grouped
together into different “sets” or “systems.” Thus, e.g., we have
the alimentary system of organs made up of the mouth, cesophagus,
stomach, and intestine—or alimentary tube—with the various organs,
liver, pancreas, &c., which are directly connected with that tube.
But every organ is made up of several different animal substances, |
variously blended, and differing in their minute or microscopic
characters. The study of such minute structure—such microscopic
anatomy—is termed Histology. Each of the various substances
thus minutely differing, and which build up the organs of the body,
is called a tissue, and Histology is, therefore, the science of the
tissues of which every living creature may be composed. Histology
enables us to understand the structure and nature of the ultimate
substance or parenchyma of the body, as far as our powers of observa-

tion at present extend; but those powers are very imperfect, and

10 THE CAT. (CHAP. I.

are very far from enablirg us really to understand the absolutely .

ultimate composition of the body.

Another science which concerns the structure of the body is
Comparative Anatomy. By it the structure of the whole body or of
any part of the body is compared with the bodies or corresponding
parts of the bodies of other creatures. The comparative anatomy
of animals is sometimes called Zootomy. The above inquiries all
refer to the number, shape, arrangement, connexion and relative
position of parts (whether large or minute), and to the resemblances
and differences between different living creatures thus regarded.

The inquiries which constitute the next set. of Biological sciences,
refer to the actions which the cat’s body performs. |

Obviously the animal moves, takes food, and, if young, increases
in size. The slightest observation convinces us that it has senses,
feelings, and emotions, more or less similar to our own. If emaciated
by starvation we see that it can by food regain its former bulk, and
we may observe that trifling wounds or injuries may be repaired.
Others of its actions normally result in the production of a new
individual—another generation. In short the animal dives. These
activities are, as we all know, shared by other animals, and some
of them by plants also, which grow and repair certain injuries—
replacing lost parts—and reproduce their kind.

§ 10. The term usually employed to denote the study of the bodily
activities, or functions generally, is PHystoLoay.

This study is made up of various subordinate inquiries. We
may consider the functions of each tissue, of each organ, and of each
system of organs. Thus we have, e.g., the study of the actions of the
system of organs which nourish and support the body: 7.e., the
study of the function of sustentation. We have again the study of
that system of organs which serves to continue the race, ¢.e., the
study of the function of reproduction.

We shall hereafter see that the former function is performed by
various organs destined respectively to receive and digest food, to
distribute about t hebody the nutritious matter obtained from it, to
breathe and to form or secrete certain products. These functions,
therefore, are those of (1) alimentation, (2) circulation, (3) respiration,
and (4) secretion.

But a creature, such as our type the cat, not only lives and repro-
duces, it is also active, and executes a great number of apparently
voluntary and other actions, and has a power of experiencing a
variety of sensations. The functions then of (1) motion, and (2)
sensation, form other subjects of physiological inquiry.

The last two functions are called the animal functions.* The
functions which minister to sustentation and reproduction, as they
are found in all living creatures, plants as well as animals, are
called the vegetative, or vegetal, functions.

* Because sensation does not exist in ; spicuous powers of motion are special
any plant, while locomotion and all con- { animal endowments.

cHap. 1] INTRODUCTORY. 11

Yet another and a somewhat peculiar study, is the study of
development. It is a study at once morphological and physiological.
For it is the study of the changes which the animal passes through
in proceeding from its first condition, as a germ, to its adult stage
of existence. It is, therefore, a study of form and a study of an
active process both together.

It is also desirable not only to note the function of each organ
and set of organs, but-also to consider the activity of the animal as
a whole—the physiology of the individual or Psychology.

§ 11. But we shall be quite unable to answer the question, What
is a cat ? if we do not learn the relations in which it stands to other
living creatures—its position in the general scheme of things: in
other words, the cat’s place in nature.

We must therefore compare the cat with all other living creatures ;
but especially with those which resemble it the more nearly. But
to do this we must first understand more or less what the general
schenie of organic nature is, that is to say, we must learn something
of the arrangement and classification of living beings, 7.e., of the
science of Taxonomy.

§ 12. Every animal and plant (and therefore, the cat and the cat
tribe) has certain definite relations to space and time. Its geo-
graphical distribution and its past history, as shown by fossil remains,
also form indispensable matters of inquiry, and respectively pertain
to the sciences of Organic Geography and Paleontology. But every
living creature has also relations with other living creatures, which may
tend to destroy it or indirectly to aid it, and the various physical forces
and conditions exercise their several influences upon it. The study
of all these complex relations to time, space, physical forces, other
organisms, and to surrounding conditions generally, constitutes the
science of Hezicology.* Ba

§ 18. But there is yet one more inquiry, without which any
modern work on zoology would be quite incomplete, and that is a
genealogical investigation, the prosecution of which pertains to the
science of Phylogeny. This science (assuming the truth of the
doctrine of evolution) + investigates the evidence as to the various
ancestral forms through which any now existing organism has
probably passed in its descent from the most remote organisms
which can, with any degree of probability, be regarded as its an-
cestors. We must then, finally, endeavour to gain what light we
may as to the first origin of that form of life which has been chosen
for study—in other words we must investigate the cat’s probable
pedigree.

§ 14. It appears to the writer that the study of the cat’s anatomy
and physiology may be best pursued by considering the function

* etis—habit, state, or condition. process of generation from other animals

+ The doctrine of evolution teaches | or plants more or less different in kind
that each existing kind of animal or | from it.
plant was originally derived by a natural

12 PH E" CATE 7% (CHAP. I,

of each organ and set of organs, together with their structure, and to
treat of them in the following order :—

I. The skeleton, both external and internal.

II. The parts which act upon the skeleton to effect motion—the

muscles.
III. The organs of alimentation.
IV. The organs of circulation.
V. The organs of respiration and secretion.
VI. The generative organs and reproduction.
VII. The nervous system and organs of sense..
VIII. The development of the body.
IX. Psychology.

The facts of structure and function having been disposed of, we
may proceed to consider the various affinities of the cat to other
animals, its relations to space and time, and the question of its
origin.

§ 15. Before, however, commencing the proposed description, it
may be well to state briefly a few facts as to the chemical composition
of the body.

The body of the cat is chemically composed of four principal
elements, namely, oxygen, hydrogen, nitrogen, and carbon, with
small quantities of other elements—sulphur, phosphorus, chlorine,
fluorine, silicon, potassium, sodium, calcium, iron, and magnesium.
These elements are united together so as to form water, carbonate
of lime, chlorides of sodium and potassium, sulphates and carbonates
of soda and potash, phosphates and carbonates of magnesia, fluoride
of calcium, and ammonia, and they are ultimately united into very
complex groups of elements, termed “organic”? compounds, the
study of which pertains to a special science called organic chemistry.
These very complex chemical groups of elements are called the
proximate elements of* the body because they are the first component
substances into which it can be dissolved when in course of being
reduced to its ultimate elements. Such proximate elements are
grouped in two classes: 1. Those called nitrogenous, because con-
taining nitrogen, and 2, the non-nitrogenous, because destitute of that
element. Most of the component substances of the body, such, e.g.,
as the flesh and the blood, are composed of the first, or nitrogenous,
proximate elements, of which the substance of the white of egg,
called albumen, and that of jelly, called gelatine, form the types.
Fats, on the contrary, are non-nitrogenous substances, and consist
only of oxygen, hydrogen, and carbon, or if they contain other ele-
ments, nitrogen is not amongst them. The nitrogenous substances
are also spoken of as proteid, because they have been supposed to be
derived from an imaginary substance termed protein, consisting of
oxygen, hydrogen, nitrogen, and carbon. They are also spoken of
as forms of protoplasm.* About four-sevenths of the weight of the

* A term proposed by Mohl to denote | creature is at first entirely composed of
the soft interior of cells. Every living ' this quaternary compound.

— a

CHAP. I.] INTRODUCTORY. 13

animal’s body is made up by water, of which it is, therefore, very
largely composed, the brain containing about seventy per cent. of
that fluid.

In saying that the body consists of different parts and substances,

‘and is made up of combinations of elements, all that is meant is

that it can be more or less readily divided into such parts, and that
it can be dissolved into such elements, just as water may be destroyed
to give place to oxygen and hydrogen. Whilst living, however,
the body really forms one continuous whole locally differentiated, that
is, assuming different appearances and possessing different properties
in different regions. ven the very blood is directly continuous
with the other constituents of the body in all actively growing parts.

CHAPTER ITI.

THE CATS GENERAL FORM.—THE SKIN AND ITS APPENDAGES.

§ 1. Tue cat’s entire frame is divisible into head, neck, trunk, tail,
and limbs, of which latter there are two pairs. Its body is every-
where more or less closely invested by a firm skin, nevertheless this
is loosely attached in certain parts and so forms folds here and there,
as e.g., between the trunk and the elbow and knee respectively. Its
skin is almost entirely clothed with hair, which is generally of
moderate length, often being longer on the belly and tail than else-

Fig. 1.—Cat’s MuzzLE, SHOWING VIBRISS& AND NAKED SKIN ABOUT THE NosTRILS.

where; but the length of the hair varies, as we have seen, according
to the breed to which different cats may belong. It is, however,
always short on the paws and face. The hairs are directed backwards
from the head to the tail, and, for the most part, downwards on the
limbs. There are long hairs inside each ear and sometimes on its tip,
and about a dozen very long and strong hairs—the whiskers or
vibrisse—are placed on each upper lip. There are also a few long
hairs over each eye, or eyebrows, but there are no eyelashes.
The end of the nose, the lips, and the skin of the fleshy pads
beneath the paws, are naked.

CHAP. II.] THE CATS GENERAL FORM. 15

The head is rounded, and the jaws are rather short. The eyes
are large, and separated by a considerable interval. The ears
become narrow as they ascend, and each stands with its deep
concavity directed forwards and outwards. The neck is a little
shorter and less voluminous than the head. The front limbs are
shorter than the hind limbs, and consist each of an upper arm, a
fore-arm, and a paw with five short toes. Each hind limb has a
thigh, a leg, and a foot with four toes. The proportions of the
body are such that both the elbow and knee are placed close to
the trunk.

Certain symmetrical relations and contrasts between different parts
of the cat’s frame are evident on even a cursory examination of it.
Thus there is an obvious contrast between its dorsal and its ventral
aspect, and this contrast extends along each limb to the ends of the
toes.

Again, there is a resemblance (and at the same time a contrast)
between the right and left sides, which correspond with tolerable
exactitude one to the other.

This harmony, termed Uelateral symmetry, though obvious exter-
nally, does not prevail in all the internal organs (viscera), which are
more or less unsymmetrically disposed.

Thirdly, there is a resemblance and correspondence between parts
placed successively, as, for example, between the arm and the leg,
or between the fore and hind paws; although this resemblance
is less obvious than it might be, owing to the different directions
in which the knee and elbow are bent. Such.a symmetry is termed
serial, and is thus even externally visible; but it becomes much
more evident when the antmal’s internal structure is examined.
There we find many successive parts—like the ribs, or the pieces of
the backbone—which obviously resemble each other very closely,
and so are called by a common name. Such parts are placed
one after another in a “‘series,” and it is on this account that the
symmetry of which they are examples is called serial symmetry.

If we remove the cat’s skin we see beneath it a mass of red flesh
—the muscles or organs of movement—and these are divided one
from another by delicate membranes. If the muscles be cut away,
we come sooner or later to subjacent bones—those of the head, neck,
trunk, tail or limbs, as the case may be. The bones of the head,
trunk and tail, are the “ skull, backbone and ribs.” |

If the trunk be cut open, it will be seen that a variety of organs
—heart, lungs, kidneys, stomach, intestines, liver, &¢ —lie enclosed
in a cavity within it. Ifthe skull and backbone be cut through, the
white substance of the brain and spinal marrow will be found within
them. Delicate threads of a similar white substance, the nerves, (which
minister to motion and feeling) traverse the body in all directions,
as also do a multitude of ‘tubes or vessels, which convey blood to or
from the heart. The anterior part of the trunk-cavity (which
contains the heart and lungs,) is divided from the hinder portion by
a fleshy and membranous partition—the diaphragm. This partition

16 THE CAT. | [CHAP, II,

is traversed by large blood-vessels and by the alimentary tube, which
extends continuously from the mouth backwards to its posterior
termination. The parts of which the cat’s body are composed are

Fig. 2.—DIAGRAM REPRESENTING A VERTICAL SECTION THROUGH THE CatT’s Bony.

m. Brain and spinal marrow contained within h. Heart.

the skull and backbone, which are deep cc. Great blood-vessels.

black. u. Urinary bladder.
st. Breast-bone. sy. Chain of sympathetic ganglia.
dd. Alimentary canal. di. Diaphragm.
s. Stomach.

thus conveniently divisible into the bones, with their membranes—
the skeleton ; the muscles; the nervous system and organs of sense;
the system of vessels, or circulatory system; the alimentary tube,
with its appendages; the lungs and kidneys, with certain other
parts, and the organs of reproduction.

THE SKELETON.

§ 2. The word “ skeleton” is popularly taken to denote only the
bones, with the cartilage or gristle which may be connected with
them. It should, however, be taken to mean not only these but
also the membranes, which radiating from the bones and cartilages
invest every organ of the body, and finally clothe it externally m
the form of “skin.” Such membranes penetrate the very bones
themselves and support the marrow they contain; they separate
every muscle from its neighbour, and surround and line each tube
and passage in the body ; so that if every other tissue could be dis-
solved away and yet this fibrous tissue be left, we should have
a complete outline model, as it were, of the cat’s entire frame.

§ 3. This substance, which is, as it were, the basis of the skeleton,
is formed of what is called conNECTIVE TISSUE, which consists of a
mass of delicate white fibres imbedded in a structureless material or
“round substance ;” scattered through this are minute particles of
protoplasm, called “ corpuscles,’ which are more or less rounded or

SS ee

CHAP, II.] . THE CATS GENERAL FORM. 17

flattened in shape, sometimes giving off ramifying processes, which
may unite with branches from neighbouring connective-tissue cor-
puscles. Within the corpuscle is a round or oval nucleus, which

contains one or more nucleoli.*

The structureless substance and

fibres form what is called the matrix of the tissue, and the cor-

Fig. 3.--CoNNECTIVE, ADIPOSR AND ELastTic TiSSsuUE.

A. Loose areolar tissue with fat cells.

fc. The fat cells.

B. and C. Magnified view of areolar tissue
treated with acetic acid. The white fibres
are here no longer seen, and the yellow or
elastic fibres with the nuclei come into
view. In Fig. B, a series of constrictions

is produced by the presence of an elastic
fibre, which is spirally disposed about the
(bere swollen and invisible) white fibres.
The white fibres may be ;53,, of an inch in
thickness or even less.

D. Fibres of yellow or elastic tissue.

puscles are cells which are thus more or less plentifully distributed

within the matrix.

Intermixed with the ordinary fibres may be others of a yellower
colour (and with a different chemical reaction), known as “ elastic
fibres,” or ‘elastic tissue.” These fibres may be rendered con-
spicuous under the microscope by the addition of acetic acid, which
causes the white fibres to swell and become indistinct, thus revealing
the existence of the unaffected yellow ones.

* It may be well to remind the reader
that the body of every animal, and there-
fore of the cat, consists at first of a single
‘* cell,” or minute particle of pretoplasm,
and afterwards, for a time, of an aggre-
gation of such cells whence all the tissues
of the body are ultimately derived, and
which in different degrees preserve traces
of their cellular origin. Cells commonly

— :

|
|

contain a modified internal part or parts
called a nucleus or nuclei, when they are
said to be ‘‘nucleated.’’ It is very
common for the nucleus to again con-
tain a more minute internal particle,
termed a ‘‘ nucleolus,” or it may have
several nucleoli. Thus, the connective-
tissue corpuscles are ‘‘ nucleated cells.”
Cc

= Erte

1 ih THE CAT. [owaP. IL

Certain portions of connective tissue which connect adjacent bones —

or cartilages become very strong, and constitute the lhgamenis.
These are flattened or rounded bands, formed of straight, parallel
fibres and are very dense in structure, with corpuscles elongated in
the direction of the fibres.

Other fibrous structures are the membranes which closely invest
the bones or cartilages, which membranes are called periosteum’ and
perichondrium respectively. These are formed of intersecting fibres,
with blood-vessels, which latter are destined to supply the structures
which the membranes invest. A more delicate connective tissue
penetrates into the cavities of many bones, and is loaded with fat,
forming what is known as marrow. Fat, or “adipose tissue,” con-
sists of round or oval vesicles (or minute bags), containing an oily
matter. The vesicles are mostly from the 51th to the =j,th of an
inch in diameter. In the earliest period of its existence the

Fig. 4.—Cat’s CARTILAGE, GREATLY MAGNIFIED,

a, Fibro-cartilage. b. Hyaline cartilage, showing the nucleated cells enclosed in the capsules,

skeleton consists entirely of connective tissue, but becomes largely
transformed into bone—i.e., it ossifies—by the deposition of cal-
careous salts around the blood-vessels, which advance and invade
the tissue about to ossify.

§ 4. CarTILAGE, is an opaque, firm but highly elastic substance,
generally of a bluish-white colour. Like connective tissue it consists
of a matrix, and this contains very distinct cells. The matrix,
however, is generally homogeneous. Such is hyaline cartilage. Certain
cartilage, however, contains fibres, and is therefore called jfibro-
cartilage, and if it contains elastic tissue also, it is known as yellow
fibro-cartilage. The cells are inclosed, either singly or mm groups,
in rounded, unbranched hollows termed capsules, the walls of which
may be somewhat denser than the rest of the matrix. Cartilage

pe ee, eS ee ee ee SP ee

CHAP, II.] THE CATS GENERAL FORM. 19

does not contain blood-vessels, but can yet grow rapidly, the nuclei of
the cells multiplying and the cells and corpuscles themselves enlarg-
ing and dividing—the homogeneous matrix coming to occupy the
intervening space as the capsules divide and separate.

§ 5. Bone, or osseous tissue, is a substance, two-thirds of which, in
the cat, consists of mineral matter—namely, of phosphate with
some carbonate of lime, and a very little fluoride of calcium, phos-

‘phate of magnesia and common salt. The animal* and mimerai
parts are absolutely united, since by the elimination of either, the
shape of the bone remains unaltered.

Compact bone, such as that which forms the thigh-bone of the
eat, exhibits on its surface a number of microscopic holes, which are
the external apertures of canals, called “‘ Haversian,’” which thence

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Fig. 5.—SectTions oF Cat’s LEG-BONE, GREATLY MAGNIFIED.

The right-hand figure shows the layers arranged
concentrically around the Haversian canal.

The left-hand figure shows a section nearly in
the plane of such a canal.

h. Haversian canal.
i. Lacune.
ce. Canaliculi.

enter and ramify. These holes and canals serve to admit blood-
vessels. The bony substance forms concentric layers about such
canals, while the layers themselves contain a number of irregular
radiating spots, which are also arranged in concentric rings corre-
sponding with the layers in which they lie. These spots are inter-
spaces called “lacunz,’’ (and sometimes “bone corpuscles,”’) and
their outline is so irregular because each gives off a number of
minute tubular processes, termed canaliculi. The canaliculi of

* This substance when boiled yields ; cooling. Connective tissue also yields
gelatine. Cartilage yields chondrin, | gelatine when boiled, but elastic tissue
which differs somewhat from gelatine in | does not. The latter tissue is also (as
its chemical relations ; but, like it, dis- | before said) unaffected by acetic acid.
solves in hot water, and forms a jelly on

c 2

20 THE CAT. [CHAP. II.

adjacent lacune unite, and thus fluid can traverse every part of
the bone. |

The Haversian canals grow larger as they proceed inwards (in
such a bone as that of the thigh,) and open into still larger channels
and yet wider interspaces which are called cancedii, ultimately
merging into a hollow central part called the medullary cavity of the
bore because it contains that delicate fibrous tissue and fat which
constitutes marrow, as already mentioned.

Some bones have their entire substance replete with cavities or
eancelli, and such are called cancedlated or spongy.

§ 6. OssiFicaTion may take place either through pre-existing carti-
lage or through membrane, and in either case
blood-vessels advance into the pre-existing ma-

he terial, and therewith that material is absorbed
) and disappears around them and is replaced by
calcareous substance. The lacune are inter-
spaces which have been left uncalcified owing
to the presence there of certain cells. These
cells have sent out radiating processes (like
some of the connective-tissue cells, as already
noticed,) which have also escaped the general
calcification of the intercellular substance, and
thus the canaliculi have been produced. Thus
contents of the lacune are truly bone-cells
or corpuscles. Bone tissue therefore is, except
as to its calcareous nature, very like connec-
tive tissue and cartilage. The bony substance
answers to the matrix of these other tissues, and
the “bone cells” to their corpuscles. When
the earthy matter of bone is dissolved their
original cellular contents may often be detected.

When a bone ossifies from cartilage, as all
thick bones do, the deposit begins in the form
of opaque granules of calcareous matter, which
Fig. 6.—Veertcar Secrion or SuLTOUnd and sometimes invade the cartilage

Car's TH1¢H-Bons (FEMUR). capsules and form a dense and irregular osseous
Sow Tot the bai, the tissue, Without lacunge or canaliculi. Spaces are

great trochanter (te), and of then formed in this substance by absorption,

its distal end (ie). 3 i

and if these spaces largely accumulate, can-

cellated tissue is formed. The spaces may,
however, become filled with a fresh and secondary deposit ef bone
in concentric rings round the blood-vessels, thus forming the
‘compact bone ” already described.

When bone is formed from membrane, it assumes the compact
form, with lacune and canaliculi, at once, and is not preceded by
granular deposit.

§ '7. The ckowTH oF BONE takes place im various ways by the ossi-
fication of the inner layer of the periosteum surrounding it. In long
bones, which are preceded by cartilage, the ends remain for some

CHAP. II.] FHE CATS GENERAL FORM. 21

time cartilaginous. These cartilaginous ends ossify subsequently,
but long continue distinct from the median part and are called
epiphyses (Fig. 6), which only unite with the rest of the bone when
the animal ~has attained maturity. Epiphyses are often developed
at-the ends of any projecting pieces of bone or “ processes.”

A bone may thus be developed from more than one point, 7.e.,
from several “centres of ossification,” the respective growths from
which ultimately unite to form one whole. A continuation of the
same process may fuse together even entire bones which have for a
time remained separate and distinct. |

The most external layer of the skim consists of yet another
substance, which is known as epithelial tissue, and which is very
distinct in nature from connective tissue or the elastic cartilaginous
or osseous modifications of connective tissue.

§ 8. Such are the substances or tissues of which the cat’s skeleton
is In its entirety composed.

That skeleton is naturally divisible into two parts:

(a.) The external, peripheral skeleton, often called the Exo-
SKELETON—the skin and its appendages.

(6.) The internal central skeleton, often termed the Enpo-
SKELETON.

§ 9. The ExrernaL SKeELeETON of the cat is made up of its skin,
with the hair which coats it, the claws, and also the teeth. No
cartilage or true bone enters into its composition.

The skin of the cat, like our own skin, consists of TWO LAYERS:
an external layer, devoid of nerves and blood-vessels (and conse-
quently of feeling), and a deeper layer, which is supplied with both
nerves and blood-vessels, and is highly sensitive. The external
layer is called the epidermis, the deep layer is called the dermis.
At the lips the external layer visibly changes in texture, and inside
the lips and mouth it becomes soft and moist, and is termed mucous
membrane. This, however, is a mere modified continuation of the
external skin. The superficial layer of inwardly reflected skin is
termed the epithelium, which is thus but a modified epidermis, and
the common term Ecrrron is applied to both epidermis and epithe-
lium, as the term EnpERon is applied to the deeper or dermal layer
(t.e., the dermis) wherever situate.

§10. The Epidermis is an EPITHELIAL TIssuUE, and consists of
_ numerous superimposed layers of epithelial cells, of which those near
the surface are flattened into scales, while the deeper ones are more
and more rounded, the deepest even assuming a vertically elongated
form. As the epidermis is worn away from the surface in minute
fragments, newer cells rise successively from below (to replace those
lost) from a layer of structureless substance which connects the epi-
dermis with the subjacent dermis. In this layer minute particles
(nuclei) arise and gather round them spheroidal portions of the sub-
stance itself, thus forming cells which subsequently multiply by spon-
taneous division or fission, the process commencing with the division
of the nucleus of each cell. The deeper strata of epidermis contain

22 THE CAT. (CHAP. 11.

the colouring matter of the skin, and are often considered as forming
a distinct part called the rete mucosum. The superficial or older
layers acquire a horny nature. The surface of the epidermis ex-
hibits numerous minute orifices of sweat-glands—the pores—and,
especially on the paws, numerous minute ridges.

§ 11. The pERMIs, or coriwm, is a form of connective tissue. Its
upper surface is almost free from fibres, but beneath, these first grow
abundant and then begin to leave larger and larger interspaces, till
the fibrous tissue becomes what is called “ areolar,” and so forms the
substance connecting the skin with the subjacent structures, ¢.e., it
forms that white, filmy substance which is broken through when the
animal is skinned. In the deeper portion of the true skin there are
curled yellow fibres of elastic tissue, and there may be some or many
muscular fibres. Its outer surface is drawn out into little promi-
nences or papille arranged in close-set parallel rows (especially on
the paws), which occasion the ridges above mentioned, or existing in
the superimposed epidermis. Many of these papille contain nerves
and blood-vessels, the former ending in a fine coil about a minute
ball or core of nucleated tissue, thus forming what are called “ axile
bodies,” or ‘touch corpuscles” (Fig. 7, B).

Sweat-glands consist of minute tubes, each opening at the surface
at a “pore,” whence it descends into the skin and passes through it
into the loose connective or areolar tissue beneath it, where it ends
in a coil surrounded by minute blood-vessels, The meshes of the
loose subcutaneous tissue contain fat, which, as before mentioned, is
enclosed in minute bags of membrane. It is fluid during the life of
the animal, and both helps to keep the body warm (being a bad
conductor of heat) and serves as a store of nutriment. Other
structures called Pacinian bodies are found in some parts of the skin
of the body—notably in a membrane (the mesentery) which invests
part of the bowels. Each such body consists of a number of layers
of membrane, with fluid interposed, and with a central space into
which a nerve enters (Fig. 7, A). |

§ 12. The ciaws, of which there are five to each fore-paw, and four

to each hind-paw, are special thickenings of epidermis, and are

(like the outer layer of epidermis generally) horny. But the dermis
is also specially modified with a view to the formation of the claws ;
for at the root of each claw it forms a transverse crescentic fold over it,
while beneath the claw, it is produced into a number of close-set rows
of papille richly supplied with blood-vessels—tforming what is called
the matrix of the claw. From its surface, and also within the
crescentic fold, fresh epidermal cells are continually formed, which
rapidly become harder, and cohere to form the claw, the root part
of which is soft, like the deeper layer of epidermis, with which
layer it is directly continuous. The claws are placed around the
terminal part of the last bone of each toe, completely investing it,
and ending in a sharp point.

§ 13. The warrs each consist of a root, fixed inthe skin, and the
shaft, or stem, which may be cylindrical, or flattened. Each hair is

— ee ee ee —— Se ee OL CU

ee! ee ee

ee ee ee ee

ee ee ee ee eee ae ee ee

CHAP. 11] THE CATS GENERAL FORM. 23

formed, like each claw, of modified epidermal cells, but then each hair
grows from a single dermal papilla only, of which it is the greatly
prolonged epidermal covering. Moreover, this dermal papilla does
not stand up from the surface of the dermis, but is placed at the

Fig, 7.
A. PAcINtIAN Bopy FROM CatT’s MESENTERY. B. TovucH-cORPUSCLE.
a. Artery. | ea. Epithelium.

c. Nuclei.
7. Core, into which the nerve enters.

n. Nerve.
f. Fibrous tissue.

bottom of a small sac, the follicle, which is a depression in the
cutis. The central part of the hair, or pith, is less dense than its
rind, or cortical substance, wich is formed of very long, horny cells
which have coalesced. Outermost of all is the cuticle or epithelial
layer, formed of very thin overlapping scales. The colouring
matter is deposited within the outermost layer, and may be uniform
throughout, or may be different in different parts of the same hair.
Some hairs are especially slender, and have the edges of the scales
of their cuticle so projecting, as to form a serrated envelope. Such
hairs are “wool,” and easily become entangled and adherent to-

_ gether by their serrations, or ‘‘ felted.” True hair, such as the cat’s,

has not the property of “felting,” because its surface is smooth.

Although hairs (like claws, and the epidermis generally) have
no blood-vessels, yet the sudden changes which may sometimes take
‘Asam in their colour, prove that nutritive modifications extend imto
them.

Very small vessels pass into the papille of the hairs, which are
also furnished with a minute nerve, to the presence of which
the pain felt when the hair is pulled out is due.

24 THE CAT. , _ (CHAP, IT.

The root, or bulb, of each hair consists of the dermal sac with its
enclosed papilla and the epidermal formation which lines the sac
and invests the papilla. It is considerably larger than the diameter
of the hair it developes.

The cat's whiskers are simply hairs of great size, the bulbs of
which are well furnished with blood-vessels and nerves.

Hairs are inserted obliquely into the skin, but can be made to
stand up, or “on end’’—as notably on the cat’s tail when the
animal is enraged—by means of the contraction of small muscular
fibres which pass from the skin to the hair-bulbs.

Fig. 8.—TRANSVERSE SECTION OF A Cat’s WHISKER, GREATLY MAGNIFIED.

e. Cortical substance. | m. Pith or medulla.

Certain accessory structures are called sebaccous glands. These
are minute flask-shaped bags (secreting an oily substance), which —
open into the upper part of the hair follicles, and so serve to
lubricate the hair.

New hairs are formed by the budding off of a new papilla and
follicle from beside those first developed, and by the growth of a
cluster of epidermie cells at the bottom of the new follicle. Neither
the new nor the older follicles are really formed by an actual in-
flection of the skin, though when completed they appear as if they
had been so formed. Minute blood-vessels and nerves enter the roots
of hairs, but do not extend beyond the dermal papilla.

§ 14. Such are the appendages and such is the nature ot the skin
which clothes the cat’s hody externally, and which varies in thickness
in different regions, being very thin on the lips, ears, and eyelids,
thicker on the back and outer sides of the limbs than on the belly,
and especially thick upon the pads of the feet on which the animal
walks. Of these there are seven in the fore paw, and five in the

/

CHAP. II, ] THE CAT'S GENERAL FORM. 25

hind paw. Each pad consists of a mass of fibrous tissue and fat,
and a large trilobed one is placed beneath the ends of those bones on
which the animal rests in walking, as represented in the figure here

Fig. 9.—UNDER SURFACE OF FORE-PAW.

I, IJ, Ill, IV, V. The five toes, I being the
pollex.

a. Trilobed pad which lies beneath the distal

_ _ ends of the metacarpal bones.

* Pad beneath the pisiform bone of the wrist.

\ a
hy

H, i
‘i

M}

yd
r i )
Wi ‘ "

Fig. 11.—CoLUMNAR CILIATED EPITHBLIAL Fig. 10.—UnpreR Surracr oF HInD-Paw.
CELLS, MAGNIFIED 300 DIAMETERS.
A number of cilia are seen on the flattened II, III, IV, and V. The respective four digits.
superficial end of each cell, which also con- a. Pad beneath the metatarsal bones.
tains a nucleus with a nucleolus, h. Heel.

given. But, as before observed, the skin does not clothe the exterior
of its body only; at the margin of the lips it is reflected inwards,
lining the mouth and continuing onto line the whole alimentary canal,
and it also lines all the other passages which open on the exterior of
the body. The cat’s body may thus be compared with a ring-shaped
air-cushion which has been very much drawn out on each surface,
the central vacant space being also greatly prolonged, but contracted
in diameter to represent the alimentary caval.

26 THE CAT. [oHaP mL.

Thus the real body of the animal lies enclosed between the external
skin and its internal reflected continuation, and answers to the en-
closed interior of the ring-like air-cushion. A real “ body cavity ” is
therefore not the inside of the alimentary canal, or the inside of any
other passage opening on the exterior; all such passages being of
course but so many continuations inwards of external space. A real
“body cavity’ would be any cavity existing enclosed between the
external skin and its internal reflected continuation. This reflected
skin is soft and delicate, with a moistened surface, and is called
“mucous membrane.” Such membrane lines two great sets of
organs. One of these is the gastro-pulmonary mucous membrane,
and lines the mouth and alimentary canal, the eyelids, ears, nostrils,
cavities in the skull, and the windpipe and lungs. The other is
called the gerito-wrinary, and lines the bladder and the parts con-
nected with its passage outwards.

§ 15. Just as the external skin consists of epidermis and dermis, so
its reflected portion consists of a non-vascular epithelium, with a sub-
jacent highly vascular coriwm, which often contains much muscular
fibre. Between them is the hemogeneous structureless layer termed
the basement membrane. The component cells of the epithelium
may be elongated at right angles to the basement membrane, thus

forming what 1s called ‘‘ columnar epithelium” (as m the stomach and —

intestine), or they may be rounded, forming sphero:dal epithehum, as
in the lining of the ducts of the “‘ glands” * of the alimentary canal.

Sometimes parts of the substance of epithelial cells may protrude
as thread-like processes or cilia, which are capable of performing
repeatedly a whipping-like movement. A membrane consisting of
such cells is called ciliated epithelium (Fig. 11), and such we shall find
in certain of the cat’s alimentary and respiratory organs, in the
description of which + this kind of tissue will be again noticed.

The corium contains yellow (or elastic) as well as white fibres,
and the supply of either may be copious or scanty. Its surface may
be even or very uneven. Thus it may be produced into many,
often relatively large, papille or vi/li—scattered or closely set—or
2a ridges which may so intersect as to form polygonal pits between
them.

Just as the outer skin is furnished with sweat and sebaceous
glands, so also mucous membrane is copiously furnished with small
glands which have different functions in different parts; but a generally
diffused secretion, called mucus, is formed by them, which gives its
name to the membrane in which its formative glands are imbedded.
It is slightly alkaline, and serves to preserve the moisture of the
surfaces it lubricates, as well as to protect them from the dissolving
action of fluids secreted to dissolve and digest food temporarily held
within cavities (the stomach é&c.) which are lned by mucous
membrane.

* Epithelial cells may, as we shal | ‘‘secretion.”” Parts which thus act are
hereafter see, take on the function termed ‘‘ glands.”
manufacturing some special product + See below, Chapter VI.

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CHAP. II.] THE CATS GENERAL FORM. £7

The mucous membrane is connected with the subjacent parts by
submucous areolar tissue, which is often lax, so that the mucous
membrane, when not stretched, is thrown into effaceable folds or
ruge. It may also form folds which are not to be effaced by any
stretching of the skin, as, e¢.g., on the palate (Fig. 86).

The membrane lining the mouth abounds in small glands,
those within the cheeks and lips being termed buccal and labial
respectively. |

§ 16. The mucous membrane of the mouth has certain calcareous
appendages—the TEETH—which are mainly calcifications of the
corium, but in part are ecteronic—or calcifications of the epithelium
—so that the nature of each is compound.

The teeth are not only parts of the external skeleton, but are

Fic. 12.—TuHe TEtTH oF THE RIGHT SIDE or a CaT’s MOUTH, SEEN ON THEIR INNER SURFACES.

Incisors. j m. Two molars. (The outer aspect of the teeth
. Canines. | is shown in Fig. 46. See also Fig. 29.)
pm. Premolars. |

closely related to the internal skeleton also, since they are implanted
in special sockets—or alveoli—provided for them in the margins of
the jawbones, which margins are on that account spoken of as
“alveolar.” The part of each tooth which is thus implanted is its
“fang.” The part which appears above the surface of the mucous
membrane is called the “crown,’”’ and the line of junction is the
cervix, or neck. Each alveolus closely invests the fang contained
within it. Most of the teeth have but a single fang, which tapers
as it penetrates its alveolus; but there may be two or three fangs to
a single tooth.

The teeth of the cat, when adult, should be thirty in number.
Those of the two sides of each jaw are alike, but those of the upper
jaw differ from those of the lower jaw.

The three front teeth of each lateral half of the upper jaw are

very small and simple in shape. They stand side by side, so that

28 THE CAT, _ (CHAP, IL

they form (with their three fellows of the opposite side) a row of six
teeth arranged in the same transverse line. Each tooth has a single,
conical fang. The first, or innermost—of the three teeth of this
kind on each side—is the smallest, and the outermost considerably
the largest. The innermost, when quite unworn, has its crown
indented by a transverse furrow, while the part anterior to the
furrow is produced into three points or cusps, whereof the middle
one is the largest. The next tooth is similar, save that the outer-
most of the three cusps is larger and the innermost one smaller
than in the tooth first described. In the third tooth there is no
innermost cusp, and the outer one is much smaller, while the inner
one (corresponding with the middle cusp of the two preceding
teeth) is very much larger, forming almost all the crown of the
tooth. This is the condition of these teeth only when quite unworn;
very soon there can only be distinguished a slight transverse pos-
teriorly placed furrow, with a prominence in front of it, which is
more or less irregular in outline. These three teeth are called
incisors, and thus there are altogether six incisors in the upper jaw.
The next tooth, which is separated from the outermost incisor by a
considerable interval or diastema, is a very large, strong conical tooth
called a canine, with a fang generally much thicker and larger than
its crown. The crown is somewhat curved, and is sharply pointed
with a strongly marked vertical groove on its outer surface, and a
less marked groove on the surface which is turned towards the inside
of the mouth. On its hinder margin is a more or less distinct
vertical ridge. |
The next tooth (separated from the canine by an interspace) is a
very small one, and, like the two which come behind it, is called
a premolar. It has an obtuse conical crown with a single fang.
The next tooth, or second premolar, is very much larger, and has
two diverging fangs, one in front of the other. Its crown is com-
pressed or flattened from within outwards, and consists of one large
triangular pointed cusp, at the: base of which there is in front a
small single tubercle, while, posteriorly, there are two small ones
juxtaposed, one behind the other. The third premolar is yet larger
—the largest of all the cat’s teeth—and from its trenchant shape (so
well adapted to cut flesh) is called the upper sectorial tooth. It has
three fangs, two smaller in front (placed one within the other on the
same transverse line) and one much larger, placed posteriorly. :
Its crown consists of three external lobes (or cusps), separated by
two notches, and of one internal tubercle. Of the external cusps
the first is the smallest, and the second, which is backwardly
directed, is the largest. A ridge from the first and second extends
inwards to meet at the internal tubercle (Fig. 29), which projects
downwards but little. A very shght horizontal prominence or
ridge (the external cingulum) connects the bases of the three external
cusps on the outer surface of the tooth. When this tooth is viewed
from within, a sharp ridge is seen to connect the middle and hind-
most of the external lobes, forming a very cutting blade, deeply

CHAP, II. | THE CATS GENERAL FORM. 29

notched at its middle. Behind the third premolar is an exceedingly
small tooth, which is called a true molar. It has two small fangs
and a flattened crown, the greatest breadth of which (Fig. 86) is
from without inwards. |The common term molars is often used to
denote all the teeth which are neither incisors nor canines ; it being
sometimes convenient to speak of such teeth as one whole, without
distinguishing between premolars and true molars. In the lower
jaw, at its anterior end, there is also a transverse row of six small
incisors. The three of each half of the jaw increase in size from
within outwards, as do those of the upper jaw; but they are all smaller
than the upper incisors, especially the third, or posterior, one, which is
not conical, like the corresponding tooth above. Then comes, with-
out any interspace, a large, strorg, pointed canine, so placed as (when
the jaws are closed) to bite in ‘ront of the upper canine, passing up
in the interspace between the upper incisors and canines. The lower
canine resembles the upper canine in shape, save that 1t 1s somewhat
shorter and more curved—its anterior and posterior margins being
rather strongly convex and concave respectively. Next to the lower
canine follow two premolars and one molar, separated however from
the canine by a wide diastema. The first premolar corresponds with
the second upper premolar, and bites in front of the latter. It has
two fangs, while its crown (like that of its analogue above) has one
large central lobe, at the base of which are two small cusps behind,
with one in front.

The second premolar has also two fangs, and is like its pre-
decessor, save that it is larger. The lower molar is very unlike
the upper one, having a more completely trenchant form than any
other tooth. It is called the lower sectorial tooth. It has two
fangs, whereof the anterior is much the larger. Its crown consists
of two nearly equal lobes, each ending in a point, the points di-
verging. At the base of the hinder side of the hinder lobe there is
a minute, scarcely perceptible, indication of a posterior tubercle or
“talon.” On its ner side, the crown is deeply excavated between
the lobes ; but externally the surface is equably convex, save that
a fissure descends vertically from the apex of the notch dividing the
two lobes. The adjacent edges of each lobe are very sharp, so that
the tooth presents an exceedingly trenchant margin, which bites
against the similarly trenchant cutting edge above described as
connecting the middle and hindmost external lobes of the upper
sectorial. Thus these two trenchant margins act together like two
‘blades of a pair of ivory scissors.

§ 17. The teeth of the adult cat are preceded by a somewhat’
different set, forming its milk-teeth or deciduous dentition. There
are on each side of the upper jaw three deciduous incisors, one
deciduous canine and three deciduous molars, and the same on each
side of the lower jaw, save that there is one deciduous molar less.
There are thus twenty-six milk-teeth in all. The deciduous incisors
appear when the kitten is between two and three weeks old, then
follow the canines and molars, all appearing by the end of the sixth

30 THE CAT. [omap, 11

week. They begin to fall out after the seventh month, but the
lower true molar comes into its place before the deciduous molars
fall out. In shape the upper incisors are like their permanent
successors, save that the transverse furrow 1s less marked. The upper
canines are smaller and less grooved than the permanent ones.

The first upper deciduous molar is a small, simple one-fanged
tooth like its vertical sue-
cessor. The second de-
ciduous molar is quite
unlike the tooth which
replaces it, but nearly
resembles the third
upper premolar or sec-
torial. Its outer cuttins
part, or blade, is three-

lobed, but both the an-
terior and posterior lobes
are notched, and the in-
ternal tubercle, which is
relatively larger than in
the permanent sectorial,
is continued from the

Fig. 13. Tae Cat’s MILK DENTITION, ENLARGED. base of the middle lobe
Below, the true molar is seen much advanced, and soon
. to rise behind the second lower deciduous molar. In There are three fangs,

the upper jaw the permanent upper sectorial is seen byt the inner fang is.

in an advanced state of development above the third : =
deciduous molar. more opposite the inter-

space between the two
outer fangs than is the case in the true or permanent sectorial.

The third upper deciduous molar is again quite different from the
tooth which succeeds it, while it resembles the true or tubercular
molar of the upper jaw, save that its relative size is larger.

The first deciduous lower molar is like the second premolar, while
the second deciduous molar is like the inferior sectorial, with a
relatively smaller anterior lobe and a much larger posterior tubercle,
or talon, which is notched so as to form two smail posterior tubercles
at the base behind the posterior and greater lobe, |

§ 18. Such being the dentition (¢.e. tooth-furniture) of the cat, it
may be conveniently expressed by the followmg symbols :—

1 cl pm m+ for the second, or permanent dentition. 13
means “‘ three incisors, above and below, on each side of the jaws; ”
c+ means similarly, ‘one canine on each side of each jaw ;” PM}
means ‘three premolars on each side of the upper jaw and two on
each side of the lower jaw;”’ and m! means “ one true molar both

above and below on each side.” Similarly, the symbols p13, pet,

pM for the milk dentition, refer in the same manner to the
deciduous incisors, canines, and molars respectively.

It need hardly be added that each tooth attains its full develop-
ment within a limited time, after which it grows no more, and no
third development ever replaces the fall of a tooth of the permanent
dentition. 1

eee ee
a? 12,

CHAP. I1.] THE CATS GENERAL FORM. 3i

§ 19. The susstance of each tooth consists of a dense tissue of three
kinds, called (1) Dentine, (2) Enamel, and (3) Cement, investing a
small soft and sensitive mass called the pudp. The great body of
each tooth is formed of dentine, and it is this which immediately
surrounds the pulp. The cement coats the fang of each tooth only,
while its crown is invested with a covering of euamel, which is the
hardest kind of tooth substance.

The pulp consists of areolar tissue with cells and nuclei, and is in
fact a modified portion of the cortum—a large dermal papilla. It is
highly vascular, and supplied with a nerve also.

Dentine is an animal substance impregnated with 72 per cent. of
earthy matter, of which nearly 67 per cent. is phosphate of lime.

as
Aad
5

«\)
ae 7

5

Gan
WS
\

CRs
ENG

Fig. 14.—Toora SUBSTANCgs.

A. Vertical section of second upper premolar. d. Dentine. c. Cement. e. Enamel.
B. Horizontal section of right upper sectorial. pe. Pulp cavity.

Instead, however, of presenting the lacunee and canaliculi of ordinary
osseous tissue, dentine only exhibits a number (but an enormous
number) of very minute and very close-set tubes, which radiate
from the wall of the pulp cavity on every side and with slight
undulations ; they become smaller towards the outer part of each
tooth, while at their inner ends their diameter is about the =,4,, of
an inch. Each tube, as it proceeds, gives off exceedingly minute
branches, which appear to anastomose, and the tubules end distally
by forming loops or by opening into minute cavities (dentinal cells)
which are disposed around the dentine close to its surface, forming
what is called its granular layer. 1
The greater part of the earthy matter is contained in the matrix,
between the tubules, which do not in fact proceed from the pulp,
but advance upon it, the outermost layer being that first calcified.
The Cement closely resembles bone, since it contains both lacune

32 THE CAT. [cHAP. II,

and canaliculi. It is thinnest towards the cervix of each tooth, and
thickens towards the apex of each fang, and there it may even
contain vascular canals like the Haversian canals of bone tissue.*

The Enamel is so mineralized a structure that it, only contains
about 34 per cent. of animal matter, while it has 90 per cent. of
phosphate of lime. It consists of a multitude of slender, solid,
undulating, hexagonal rods, closely adjusted to each other, and
about ,;'>, of an inch in diameter. Lach rod is attached by one
end to a minute depression of the surface of the uentine, and thence
extends outwards, its distal part being
at right angles to the external surface
of the enamel.

§ 20. We have seen that hair and claws
are epidermic dermal appendages, but
ceeth are appendages of the dermis. They
are not altogether so, however; for though
the dentine is formed by ossification of a
process of the corium, and cement by caleifi-
cation of the connective tissue surrounding
that papilla, yet the enamel has a different,
and indeed an epidermalorigin. Itis formed
from a depression of the epithelium of the
gum, which dips in till it becomes apphed
to the apex of the rising dermal papilla,
which last is destined, by its calcification,
to form the bulk of the tooth. Having
thus applied itself to invest the crown of
the nascent tooth, it calcifies and so be-
comes the enamel.

Thus each tooth has a double nature. By

tia) i

inti) 4) ,

wd i tg ify

Y i i of a at fy

ie ef Y pi

‘Z Wiis Wi, TM
i,

ad, its dentine and cement it is dermal, but
i) / its enamel is a modification of the epi-
he J dermis.

Fig. 15.—Taw Sromon orm . ach permanent tooth takes its origin
ENAMEL AND 4 rant or Taz IN a cavity of the jaw, placed just behind
a aig the milk-tooth it is destined to succeed.

b. The rods or solid, six-sidea A little process from the inflected epi-
sali of thelium (or “enamel organ”) which

d. Tubuli of the dentine.

c. Clefts which occasionally forms the enamel of the milk-tooth, is
exist in the deep part . ° . :
of the enamel. given off to invest the minute papilla

which is to grow into the permanent tooth.

As the new tooth is formed it rises in the gum, the space inter-
vening between it and its successor becoming richly supplied with
blood-vessels. The substance of the milk-tooth then becomes

* A substance called osteo-dentine is | centric lamelle, and is so far like bone.
sometimes produced by the ossification | On the other hand, tubuli radiate from
of the pulp itself. It has vascular quasi | these canals, which tubuli are larger
Haversian canals, surrounded by con- | than the canaliculi of bone.

an

if De he et lh oe ee ek!) Bd
. in ‘
x

CHAP. I1.] THE CATS GENERAL FORM. 33

rapidly absorbed away by the aid of the blood-vessels—first the
cement, then the dentine, and even part of the enamel—till what is
left becomes loosened and falls out. As the new tooth rises into the
place of its predecessor, the bone of the jaw becomes simultaneously
modified by absorption and redeposition, so as accurately to fit its
fang—a striking example of that wonderful power of harmonious

and spontaneous modification which pervades the living body.

CHAPTER III.
THE SKELETON OF THE HEAD AND TRUNK.

§ 1. Tue internal skeleton, or endoskeleton, of the cat is made up
of numerous bones with cartilages and fibrous structures.

The number and nature of the parts vary with age. In the
earlier stages of existence the cat has no bones at all, but ossification
having once begun, goes on for a time energetically till maturity 1s
attained ; and, indeed, to a certain extent ossification goes on
throughout life.

In this way it comes about that parts which are membranous mm
the kitten, or cartilaginous in the young cat, become bony in the
full-grown animal. A continuation of the same process tends
to unite bones which at their first appearance were separate.
This process of union of bone with bone is called anchylosis. The
hard parts of the internal skeleton being those which act as a
framework support the body, form points of attachment for the
muscles which move it; the muscles employing the different bones
like so many levers or fulcra, as the case may be.

The great majority of bones being thus intended to move one
upon another, certain parts of their surfaces are specially modified
for mutual adjustment and motion, i.e. the contiguous surfaces of
such movable bones form JornTs.

These modifications will appear, as the forms of the bones are
successively noticed; but the nature and mechanism of all the
different kinds of joint will be more conveniently considered together
after the skeleton has been described, immediately before studying
the m oving organs themselves.

§ 2. The parts which compose the internal skeleton may obviously
be grouped into two divisions :— ;

(a). The skeleton of the head, trunk, and tail, which is called
the aAx1AL skeleton. ;

(b). The skeleton of the limbs, which is called the APPENDI-
CULAR SKELETON, the limbs being regarded as appendages of
the axial part of the body. |

THE AXIAL SKELETON.

The axial skeleton is further conveniently divisible into the
skeleton of the back, or spenal skeleton,—consisting of what 1s

ie ila
sci —
oan —" a en ee
ae eee ee ses =

i i ent colt Nada

4
:
4
;
|

ee eT eee

Sil : Peas
Fa Mi teh Nie ee Dtelpg tg in a he tel gle hel SF aa oie tar at bys: hig REN De

CHAP. III. ] SKELETON OF THE HEAD AND TRUNK. 35

familiarly known as the backbone, ribs and breastbone—and the
skeleton of the head, or cranial skeleton.

THE SPINAL SKELETON.

As has been said, this consists of the backbone, together with certain
arches, the ribs, which extend from each side of a certain portion of
the backbone downwards to or towards the breastbone or sternum.

§ 3. The backbone, or, as it is often called, the spine or spinal
column, consists of a number of small bones placed one behind the
other, like a series of counters. Each of these small bones is called
@ VERTEBRA, and (with certain few exceptions, to be considered
later) consists of a bony arch projecting upwards from a solid disk—
the counter-like portion of the bone. LKach whole vertebra may
thus be described as a ring much expanded at one part, which is
the lower part, and with certain bony prominences, which stand out
from the bony ring in various directions.

The vertebrze being, as has been said, placed one behind or in
front of the other, their juxtaposed rings together form a lon
horizontal canal (ring being placed opposite ring), which is called
the vertebral canal. It is also called the neural canal, because it is
destined to contain and protect the central part of the nervous
system of the trunk, namely the spinal cord—or, as it is popularly
termed, the spinal marrow.

The thickened inferior parts of the vertebra are also adjusted one
in front of another, and by their juxtaposition form a solid but
flexible horizontal red.

§ 4. The thickened inferior part of each vertebra is called its
“body,” or centrum (see Fig. 16); the ring of the vertebra springing
from the centrum is called, as before said, the neural arch. Kach
lateral half of the neural arch consists of two parts: an inferior
rounded part called the pedicle, and a superior broad and flat
portion called the newral lamina.

The various bony prominences of the vertebre are termed
“ processes,” and at least three kinds of such processes are very
generally present. |

The first of these is the process which prvjects upwards from the
junction of the neural lamine at the summit of the neural arch.
This is the spinous process, neural spine, or neurapophysis. From the
junction of each lamina with its pedicle another process, ending
bluntly, juts outwards and upwards: this is called the transverse
process. Other processes which project more or less forwards and
backwards from the outer part of each lamina to meet corresponding
processes of adjacent vertebree, are termed articular processes or
sygapophyses.

Those projecting forwards have a smooth articular surface, which
looks mainly upwards, and are called anterior articular processes, or
vrezygapophyses.

Dag

36 | THE CAT. (CHAP. III.

Those projecting backwards have a smooth articular surface, which
looks mainly downwards, and are called posterior articular processes,
or postsygapophyses.

The anterior margin of each pedicle is somewhat concave, while
its posterior margin is generally more so. In this way, the vertebrae
being naturally juxtaposed, the adjomed concavities, or notches, of
two adjesent vertebrae, constitute a rounded opening termed an
intervertebral foramen. These foramina communicate with the
neural canal, and enable nerves and vessels to pass thence outwards.

The adjacent surfaces of the bodies of the vertebrae are nearly
flat, and are connected together by the intervention of a fibrous pad
—the intervertebral substance—which will be described later,
amongst the ligaments. ;

The vertebrae are composed of cancellous bony tissue invested by —

compact bone. The latter is most abundant on the arch and
processes. The body of each vertebra is almost entirely composed
of spongy substance traversed by canals for veins.

Such is the general condition of most of the vertebrae, but in
some of them certain of their parts and processes are wanting, while
in others there are additional parts and processes.

§ 5. The vertebre are divisible into five different carEGortzEs. (See
Mies) -¢. a, 4, 8, and ca),

First’come those of the neck, which are termed cervical. They
are seven in number. |

Secondly, those of the back, which have the ribs attached to them
and are called dorsal. Of these there are thirteen.

Thirdly, we find certain large vertebree which do not bear ribs:
these are situate behind the dorsal vertebree and are called dumbar.
There are seven of them.

All the above are termed “true vertebre,” because they do not
become anchylosed together, but remain connected only by higaments
and by the intervertebral substances.

Behind these true vertebree come three which are called “ false,”
and which sooner or later anchylose together to form a bony mass. |

This mass, termed the sacrum, comes immediately behind the
lumbar vertebre, and part of it affords attachment on each side to
one of the haunch, or hip, bones. The sacral vertebree thus anchy-
lose together to constitute the sacrum. The rest of the vertebree are
called caudal, and form a series of some twenty bones which decrease,
gradually, backwards as regards their complexity of structure, but
increase in length to about the tenth, and then again become
successively shorter, as well as simpler, to the end of the tail.

§ 6. Of the vertebrae, the porsaL, as the simplest of those in
front of the tail, may first be selected for description, the fifth
dorsal being taken as the type. The centrum of this vertebra (¢)
is about three quarters as deep from above downwards as it is
broad from side to side, its length (from before backwards) being
about equal to its breadth. Its upper surface is more or less flat-
tened. Its under surface is strongly convex from side to side,

AE i gO mB A A Bl i en ah Sap cites loag ies

CHAP. III. | SKELETON OF THE HEAD AND TRUNK. 37

and somewhat concave from before backwards. Its anterior and
posterior surfaces are flattened, but the former is somewhat convex
and the latter somewhat concave. The pedicles have their anterior
notches very shallow, but their posterior ones very deep. The
neural lamine are almost as wide from before backwards as from
side to side, and the neural arch overlaps that of the vertebra

Fig. 16.—Firta Dorsal VERTEBRA.

A. The vertebra seen on its right side. | p. Capitular surfaces.

B. Anterior view. s. Neural spine.

C. Posterior view. t. Transverse process.

bo. Small tubercle. Z. Anterior zygapophysis.
c. Centruin. 3. Posterior zygapophysis.
d. Tubercular surface.

next behind. The spinous process is very elongated, pointed and
inclined upwards and backwards. ‘The zygapophyses are almost
horizontal, the anterior ones (Z) looking upwards and _ slightly
forwards and outwards; the posterior ones (3) looking downwards
and slightly backwards and inwards.

The transverse process (¢) projects outwards from nearly the
summit of each pedicle, almost entirely hiding the anterior zyg-
apophyses when the vertebra is seen in profile. A little tubercle (6)
projects from the upper surface of the distal part of the transverse
‘process.*

Like almost all the other dorsal vertebre, the fifth dorsal exhibits
- certain articular surfaces which are called costal, because they serve
for the attachments of the ribs. There are two kinds of such
surfaces. One kind, attached to the centrum, are called capitudar,
because they articulate with the heads, or the capitula, of the ribs.
The other kind, attached to the transverse processes, are called

* “Distal” and ‘‘ proximal” are two | distal part of a limb; that part of a limb
words respectively expressing remoteness | which joins the body is the proximal
from and nearness to a centre or point of | part. The tip of the tail is ‘‘ distal ;”
attachment. Thus, ¢.g. the paw is the | its root is ‘‘ proximal.”

38 THE CAT. ep.hing 5k Ns (CHAP, III.

tubercular, because they articulate with the tubercles of the ribs.
The tubercular surface (d) is a smooth, oval surface, slightly pro-
longed from before backwards, and placed one beneath the distal
end of each transverse process and giving attachment to the tubercle
of the fifth rib.

The capitular surfaces (p, p) are two im number on each side.
One is placed at the junction of the pedicle with the centrum in
front; it is smooth, and looks forwards and outwards. The other
is placed just beneath the postenor notch of the pedicle; it is
smooth, and looks so almost directly backwards and so very little
outwards as to form part (the outer and upper angle) of the posterior
surface of the centrum. The anterior capitular surface concurs with
the posterior capitular surface of the fourth vertebra to form with it
an articular cavity for the head of the fifth mb. Similarly its
posterior capitular surface concurs with the anterior capitular surface
of the sixth vertebra to form an articular cavity for the head of the
sixth rib.

The ring formed by the neural arch and centrum is oval, trans-
versely extended, and somewhat flattened below.

The eleventh, twelfth and thirteenth dorsal vertebrae have each but
a single capitular surface on each side—namely, an anterior one.
The first dorsal has an anterior capitular surface large enough to —
receive the whole head of the first mb. The eleventh, twelfth and
thirteenth vertebree have no tubercular surface.

The first two dorsal vertebree have the front surface of the centrum
strongly convex and looking much downwards, and its hinder surface
concave and looking much upwards. ‘The tubercular surface also is
strongly concave. :

As we proceed from before backwards, through the series of dorsal
vertebree to the tenth, the transverse processes come to extend less
outwards and to be more expanded from before backwards at their
distal ends ; the postzygapophyses become situated further backwards,
and the neural spines (counting, at least, from the seventh,) also
become shorter.

The tenth dorsal vertebra has its transverse process very much
extended from before backwards (Fig. 17,!°). Its posterior end projects
backwards more than in any preceding vertebra, reaching to, or
even beyond, the anterior margin of the pedicle of the eleventh
vertebra. The postzygapophyses look as much outwards as down-
wards, or even mainly outwards. -

In the eleventh dorsal vertebra the neural spine projects more or —
less forwards (Fig. 17, !! *), instead of backwards, abutting against
that of the tenth vertebra, which it may, or may not, slightly
exceed in length. It has no transverse process, but there are
two conspicuous processes on each side, which evidently answer
to the processes (one at each end) which terminate the transverse
process of the tenth vertebra, but which, in the eleventh vertebra,
are quite separated the one from the other. |

The anterior process (Fig. 17, = ™), which projects forwards,

FR ne ee ee ET ee ee

Do bsinay ee iach, Hae cegstnnt eign mnpis

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. a)

“4 upwards and outwards, outside the prezygapophysis, is termed the
‘ mammillary process, or Metapophysis.

The posterior process (a), which projects backwards as:much as
any other part of the vertebra, is called the accessory process, or
Anapophysis. .

The prezygapophyses look almost entirely inwards, while the
postzygapophyses (3) look almost entirely outwards.

The twelfth and thirteenth dorsal vertebre are like the eleventh,
but their anapophyses are stouter and their neural spines are larger
and project more forward.

§'7. The seven LUMBAR VERTERBR#® are larger and more massive
than the dorsal vertebrae, and increase in size as we proceed back-
wards as far as the sixth lumbar (see Fig. 23).

Selecting the fifth for comparison with the fifth dorsal, we find its
centrum broader in proportion to its depth, about twice as long,
less convex transversely below, and
with a slight median ridge, called
hypapophysial,* running from before
backwards, along its under surface.
The neural lamina and pedicel are
much longer, and the latter, though
deeply notched behind, is scarcely at
all so in front.

The neural spine is very much
phorter, absolutely ag well as relatively. —-pan®s ann brovenen Vuwrmpeon
It is elongated from before backwards, = **7¢#TLY SEPARATED.

and inclines forwards instead of back- Ay LS ele aera
wards, thus agreeing with the last re es:
three dorsal vertebree. m. Metapophysis.

The zygapophyses are thicker, and 1S) NC a Sa arc
their articular surfaces are differently Bn dares
shaped from those of the dorsal vertebre. s, Neural spine.

: 5 Z. Anterior zygapophysis.
Each prezygapophysial surface is 3 Posterior zygapophysis.

concave, and looks inwards as well as
upwards. The postzygapophysial surfaces are convex, and look
outwards as well as downwards, being embraced by the pre-
zygapophyses of the vertebra next behind. The transverse processes
are very much longer than those of the dorsal vertebra, and project
very much forwards and strongly downwards as well as slightly
outwards. There are no capitular or tubercular surfaces, the
lumbar vertebre not bearing ribs.

The metapophyses and anapophyses are large and conspicuous,
though not more so than in the last dorsal vertebra.

The neural canal is larger and more quadrangular than in the
dorsal region.

The more anterior lumbar vertebre closely resemble the: more

* Because it represents a certain process, present in many other animals,
which is called a hypapophysis.

40 THE CAT. CHAP, III.

posterior dorsal vertebree, the first lumbar being quite like the ast
dorsal, except that it has no capitular surface, but, in its place, a
short forwardly extending transverse process, and that the meb-
apophyses are somewhat larger.

As we proceed backwards through the series of lumbar vertelngs

Fig. 18.—Firta LumMBaR VERTEBRA.

_@, Anapophysis. s. Neural spine.
c. Centrnm. t. Transverse process,
m. Metapophysis. z, Prezygapophysis.
m. Neural lamina, 3. Postzygapophysis.

the anapophysis decreases, so that in the sixth lumbar there is but a
minute rudiment of such a process. The metapophysis is at its
maximum in the fourth lumbar vertebra, but is large even in the
last. The neural spine is longest at the fourth. The transverse
process increases rapidly from the first lumbar vertebra to the
fourth, and is slightly longer in the fifth and sixth lumbar vertebree.
The zygapophyses continue to be directed as in the fifth lumbar
vertebra, except that the postzygapophyses of the seventh look
once again more downwards.

The centrum of the seventh lumbar vertebra is not longer than is
that of the first, and the same is the case with the neural arch.

§ 8. Having noted the characters of the vertebrae next behind the
dorsal ones, we may advance to those in front of them.

Of the seven CERVICAL VERTEBR& the first two are sufficiently
exceptional to demand separate notice. The other cervicals are very
much alike, but the fifth may be selected for comparison with the

fifth dorsal vertebra.

Its centrum is relatively wider from side to side and narrower

<li ied Depa ae me ~ :

a a a a ee ee ee

= So

CHAP. III. ] SKELETON OF THE HEAD AND TRUNE. 41

from above downwards than in either the dorsal or the lumbar
vertebre. The front surface of the centrum is convex, and looks
much downwards as well as forwards, and its hinder surface is
concave and looks much upwards as well as backwards. The
pedicle is narrow from before backwards, and its anterior notch is
as marked as its posterior one; but this appearance is mainly due
to the projection forwards of the prezygapophysis (z). The neural
lamin are much flattened, and are broadened transversely like the
centra. ‘The spinous process is short, small, and projects somewhat
forwards. The zygapophyses are large and flat. The articular
surface of each prezygapophysis looks upwards, forwards, and

Fig. 19..—_FirtH CERVICAl. VERTEBRA.

A. Side view. | t. Transverse process.
B. Front view. ». Vertebral canal.

c. Centrum. 3. Postzyzapophysis.

C. Back view. z. Prezygapophysis.
s. Neural spine.

slightly inwards. Its outer surface presents a roughened pro-
minence. ‘The articular surface of each postzygapophysis looks
downwards, backwards and slightly outwards.

There is a large plate-like transverse process (¢) which springs
from two roots. One of these descends from the front of the side
of the pedicle, the other projects from the centrum, just at the place
where the capitular articular surface of a dorsal vertebra is placed,
and so may be called a “capitular process.” These two short roots
unite and enclose a space (v) called the vertebral canal, because it is
traversed by the vertebral artery. Thus this vertebra may be said
to have “perforated transverse processes.” Beyond the junction of
its two roots the transverse process expands into an irregularly
quadrilateral plate, one surface of which looks outwards, upwards,
and slightly forwards, while the other looks inwards, downwards,
and slightly backwards. From near the hinder angle of this plate
a process, somewhat like an anapophysis, projects upwards and
backwards, so that the plate may be said, at this part, to shghtly
bifurcate.

The other cervical vertebra (except the first two) more or less

» bs oe Golekdd MeGeeds

49 | _ PHE CAT. boob (cas

closely resemble the fifth cervical. The seventh, however, has a longer
spinous process (like that of a dorsal vertebra), and no vertebral
zanal—only that part of the transverse process being developed,
which corresponds with root above the vertebral canal and with
the anapophysis-like process of the transverse process of the fifth
vertebra, These parts, therefore, may be taken to represent the

Fig. 20.—THe Axis VERTEBRA.
A. Side view. | al. Anterior articular surface.

. Posterior articular surface of centru
. Odontoid process.

Neural spine.

Transverse process.

. Posterior zygapophysis.

B. Front view.
C. Back view.
D. Dorsal view. |

NHHOS

E. Ventral view.

tubercular process of a dorsal vertebra, while the rest of the cervical
transverse process, where present, represents a rib. ©

The sixth cervical vertebra has the anapophysis-like process very
large, while the lamellar transverse process 1s much developed
behind and within it, so that the process of bifurcation, which was
incipient in the fifth cervical, is, in the sixth, so advanced that the
transverse process may certainly be said to bifurcate posteriorly.

In the fourth and third vertebree the transverse process becomes
simpler and relatively more extended from before backwards, but is
always perforated.

_ CHAP, IIT. ] SKELETON OF THE HEAD AND TRUNK. 43

_ The convexity outside the prezygapophysis is at its maximum in
the fourth vertebra. It is really a rudimentary metapophysis.

The neural laminez of the sixth and seventh vertebre show a
ridge-like process on the inner side of each postzygapophysis. This
is called a hyperapophysis.

§ 9. The second cervical vertebra, termed the axis, differs con-
spicuonsly from every other bone of the spine in having a large blunt

B

Fig. 21,.—Tar ATLAS VERTEBRA.

A. Side view. f. Foramina.

B. Front view. n. Neural lamina.

C. Back view s. Rudiment of neural spine.
D. Dorsal view. | t. Transverse process.

E. Ventral view z. Articular surfaces.

| y# Hypapophysial tubercle.

process of bone (like a tooth or peg, o), extending forwards from
the anterior portion of the centrum—on which account the bone is
sometimes termed the vertebra dentata. 'This eminence 1s called the
odontoid process. It presents a smooth articular surface below, and
a smocth groove above. The lower surface of the rest of the
centrum of the axis exhibits a median hypapophysial prominence
or ridge. The pedicle has a very deep anterior notch, beneath
which is an anterior lateral articular surface (a/), instead of a pre-
zygapophysis. The neural spine (s) is merely an elongated mdge
extending along the summit of the stout neural Jamine.

The postzygapophyses (z) exist as usual, but the prezygapo-
physes are, as has just been said, absent. There is however instead,
on each side, the just mentioned large articular surface (a/), looking
forwards and outwards, and supported on the centrum, beside but
behind the odontoid process. The transverse process (¢) is short,
pointed, perforated, and backwardly projecting from near the
hinder end of the side of the centrum.

44 THE CAT. [onap. III,

§ 10. The first vertebra of all, called the arnas, also differs con-
spicuously from every other bone of the spine. It differs by the
large size of the aperture it encloses and by the smallness of the part
which, at first sight, appears to represent the centrum, as also by
the absence of a neural spine. The ring it forms is wider above
than below, and it is this wider part which corresponds to the
neural arches of the other vertebre. The narrower ventral part
receives upon it the odontoid process of the axis. The part which
seems to, but does not truly represent the centrum, articulates by
its upper surface with the under surface of the odontoid process,
while its own under surface developes a slight median prominence (y)
or hypapophysial tubercle. ‘The neural arch (m) is slightly wider
from behind forwards than in the other cervical vertebrae, and there
is no neural spine, or only a minute rudiment of it (s). Each
neural lamina is perforated just above the anterior articular surface
(Fig. 21, B, f). The vertebral artery and sub-occipital nerve
traverse this foramen. ‘The sides of the atlas vertebra are termed
“the lateral masses,” and give rise to the great, wing-like, trans-
verse processes (¢), and to large anterior and posterior articular sur-
faces. There are no true zygapophyses. The transverse processes are
longer and larger than in the other cervical vertebrae, and consist
of a tubercular and capitular process, united at their distal ends,
or enclosing a small foramen for the vertebral artery (Fig. 21,
C and D, f), and then expanding into a plate of bone, one side of
which looks upwards and the other downwards. Of the four large
articular surfaces two are situated behind the root of each transverse
process (Fig. 21, C, z), and correspond in position with the anterior
articular surfaces of the axis, before described. The anterior pair
of surfaces (Fig. 21, Band H, z) are very large, cup-shaped, and oval,
converging inferiorly, and looking mwards as well as forwards.
They receive and articulate with two prominences of the hinder
end of the skull. At the inner margin of each is a minute, smooth,
rounded tubercle. The hinder pair of articular surfaces (Fig. 21,
C and D, z) are smaller than the anterior pair, and are more elongated
in shape and flatter. They are inclined a little inwards as well as
upwards and backwards, and join the anterior articular surfaces of
the axis vertebra. .

The atlas is formed to turn on the odontoid process of the axis as
on a pivot, as will be further explained when the ligaments come
to be described. :

§ 11. Next to be noticed are the three (sometimes four) vertebre
which are often called ‘‘ false,” because they anchylose together into
one bony mass, and so constitute the sAcRUM.

This bone immediately succeeds the hindmost Inmbar vertebra,
and is roughly quadrangular in form, but the transverse. diameter of
its hinder end is considerably less than that of its anterior portion.

The composite nature of the sacrum is plainly manifested (in the
fully ossified bone of even the most aged individuals) by its processes
and perforations, and by the transverse markings of its ventral surface.

b = , “ 2 * ine se -
ee al SE pian EE he

jn one ~ Paes

ES oA 5

> ae ee ee ee re

“a

CHAP. III. ] SKELETON OF THE HEAD AND TRUNK. 45

Its first component vertebra is considerably larger than the two suc-
ceeding ones, which are about equal in size.

The ventral surface of the sacrum (A) is markedly concave from
before backwards, and is also concave transversely at its more an-
terior part. It is marked by two transverse lines (which indicate
the original limits of the vertebral centra), and at each end of each
line is a considerable aperture or foramen (f). These four open-
ings, called the ventral sacral foramina, give exit to the anterior
divisions of the sacral nerves.

Fig 22.—THe Sacrum

A. Ventral view. 1. Lateral masses.

B. Dorsal view. - m. Rudiments of zygapophyses and metapo
C. Front view. physes conjoined.

c. Anterior central articular surface. s. Neural spines.

f. Foramina. z. and 3. Zygapophyses.

The dorsal surface of the sacrum is rough, and exhibits three
neural spines (s) projecting nearly straight upwards. They are all
shorter than the neural spine of the last lumbar vertebra, and the
third sacral neural spime is much smaller than the two in front of
it, whereof the first is the taller.

External to the neural spines, and at the outer margins of the neural
laminee (which form a completely roofed neural canal throughout
the sacrum), there are, on each side, four eminences, representing
zygapophyses or metapophyses, or both(m). Thus at the anterior
end of the centrum we have (s) on each side a prezygapophysis
(with its outer margin prolonged by the metapophysis), which is
like that of the last sacral vertebra, except that it 1s somewhat
larger. Behind this there is a smaller prominence, which represents
the conjoined metapophysis and zygapophysis anchylosed together
at the junction of the first and second sacral vertebrae. Behind this,
again, there is another still smaller prominence which represents the
same parts at the junction of the second and third sacral vertebree.
Behind this again, and close behind the third sacral neural spine, is
a third process (which is the postzygapophysis of the third sacral
vertebra) which articulates with the first vertebra of the tail (3).

Just external to each process formed of coalesced and anchylosed
zygapophyses, is a considerable aperture or foramen. There are
four such, and these are termed the dorsal sacral foramina, and they

46 HB! OAT [CHAP. III.

are placed directly over the ventral sacral foramina before described.

The bony substance of each sacral vertebra projects outwards beyond
these foramina, forming what 1s called the “‘ dateral masses” of the
sacrum (/), which are in fact the coalesced transverse processes of
the sacral vertebree.

The formation of the ventral and dorsal sacral foramina may be
thus explained. Nerves in the true vertebre pass out, as we have
seen, between the pedicles of adjacent vertebrae. Now the coa-
lescence of the sacral transverse processes necessarily changes each
such intervertebral opening into a pair of openings, of which one is
dorsal and the other ventral.

In a line connecting each pair of dorsal sacral foramina, slight
irregular perforations in the roof of the neural canal indicate the
primitive interspaces which existed between adjacent sacral vertebree.
At the anterior end of the sacrum is an articular surface (c),
very wide but narrow from above downwards, which joins the
centrum of the last lumbar vertebra. Above this is the opening of
the neural canal, also greatly extended transversely, and narrow
from above downwards, and the prezygapophyses and neural spine
before mentioned. Extending out from each side of the front
articular surface of the centrum are the two “lateral masses,” which
project strongly outwards, downwards, and somewhat forwards.

At the posterior end of the sacrum there is a small oval articular
surface, which joins the centrum of the first caudal vertebra. On
each side of it the “lateral masses” —here small, thin bony plates—
project outwards. Above it is the small crescentic opening of the
hinder end of the sacral neural canal, surmounted by the neural
spine and postzygapophyses (z) befure mentioned.

The sacrum, viewed laterally, exhibits the neural spines, zyg-
apophyses, and dorsal foramina before described, and below these,
one of the lateral masses, which appears deep in front and tapers
rapidiy backwards. On its deep part is a large irregular surtace,
which in the living animal is coated with cartilage, and articulates
with the hip or haunch-bone. This surface is somewhat crescentie,
with the concavity upwards, and is called the auricular surface, because
the corresponding part in man has an outline somewhat resembling
an ear. Above this surfuce the lateral mass is more or less excavated
and uneven. The auricular surface may be entirely supported by that
part of the lateral mass which pertains to the first sacral vertebra; it
may, however, extend on to part of that pertaining to the second
sacral vertebra. That part which pertains to the third sacral vertebra
ends behind in a poited process extending outwards as well as
backwards to about the level of the middle of the sacrum’s hinder
central surface.

§ 12. The last part of the cat’s spine is formed by the cauDAL
VERTEBRE (see Fig. 23), usually about eighteen or nineteen im
number, but sometimes as many as twenty-four. Of course the
short-tailed breeds have only a few caudal vertebre. In the Manx
cat there are four, and in the Malay cat several of the vertebrae

cHaP. 11.) © SKELETON OF THE HEAD AND TRUNK. 47

towards the middle or more distal part of the tail are distorted,
atrophied, and more or less fused together at the place where the
tail is so suddenly contorted.

With age, the first caudal may anchylose with the third sacral
vertebra, which it resembles much both im size and shape, though
its neural spine is smaller and its transverse process (which projects
strongly backwards and slightly outwards) is narrower from behind
forwards than is the lateral mass of the third sacral vertebra. The
two next caudal vertebree closely resemble the first, though they are
slightly longer. The fourth caudal vertebra is again longer, its
neural spine is hardly to be detected, and its shorter transverse
processes project outwards and backwards from the hinder part of
the side of its centrum. Two shght hypapophysial prominences are
also to be detected side by side and but little separated, at the
anterior end of the ventral surface of the centrum. The neural
canal is also much reduced in size. The fifth caudal vertebra
exaggerates the same characters, as also does the sixth, in which
the neural canal is very small. Here also a minute transverse
process begins to show itself projecting outwards from the anterior
end of each side of the centrum, while that projecting from its
posterior end is so reduced as to be scarcely, if at all, larger than is
the transverse process thus newly appearing at the anterior end of
this vertebra; in which, moreover, the prezygapophyses no longer
articulate with the postzygapophyses in front of them.

In the seventh caudal vertebra the minute neural canal is hardly
enclosed by bone, and is only so near the median part of the bone.
The prezygapophyses are the longest processes, and the anterior
transverse processes are rather longer than the posterior ones. The
transverse processes in the eighth vertebra are hardly more prominent
than are the hypapophysial ones, but the whole bone continues to
increase in length. In the ninth vertebra there is an open groove
instead of a neural canal. The tenth is about the absolutely longest
vertebra. ‘Thence onwards the processes become less and less marked,
and the vertebra, from the eleventh or twelfth, begin manifestly to
decrease in length and all other dimensions—the last vertebree being
little more than small cylindrical ossicles, each formed of a centrum
only, with faint mdications at each end of processes corresponding
with those described as existing in the more anterior vertebre.
Thus the last vertebra is the very opposite to the first (or atlas),
being all centrum, while the atlas has no proper centrum at ali.

Certain very small Y- shaped bones called chevron bones are arti-
culated beneath the interspaces and adjacent ends of the caudal
vertebre, from the second to the tenth or eleventh vertebra.

§ 13. The wHo te septs of vertebrees thus form a jointed rod—
the spinal or vertebral column. Its component vertebrae, moreover,
are so disposed that the backbone, when seen in profile, presents,
between the atlas and the tail, two curvatures (see ante,
Fig. 2), directed alternately upwards and downwards. Thus the
cervical vertebre form a curve which is convex downwards, while

Fig. 23. — VENTRAL
ASPECT OF THE VER-
TEBRAL COLUMN.

c. Cervical,

d. Dorsal,

7. Lumbar,

s. Sacral, and

ca. Caudal vertebre.

THE CAT. [CHAP, III.

the dorsal and lumbar vertebre together form
a curve which is much more strongly convex
upwards than the preceding curve is convex

downwards. The neural spines (which are longest ©

in the dorsal vertebrae) change their direction at
about the middle of the posterior curve, that of
the tenth dorsal vertebra inclining backwards,
and that of the eleventh forwards, their junction
indicating the centre of motion.

The breadth of the ventral part of the back-
bone (7.e. the transverse diameter of the vertebral
centra), narrows slightly from the axis to the first
dorsal vertebra ; it remains much the same to
about the fifth, and then gradually widens to the
first sacral, whence it again decreases rapidly
to the beginning of the tail, and then very
gradually to the end of that organ. The width
of the column, including the transverse pro-
cesses and the lateral masses of the sacrum, is
at its maximum at once at the atlas, and sud-
denly decreasing at the axis. It thence remains
much the same, but gradually broadens to the
first dorsal, whence it again very gradually
narrows to the last dorsal vertebra. Thence it at
once increases rapidly to the last lumbar vertebra,
which is about as wide as is the atlas. Thence
backwards the spine gradually narrows to the end
of the vertebral series. |

The ventral surface of the vertebral column
bears no median prominence save the slight
longitudinal one beneath the centrum of the axis,
and of certain lumbar vertebre, together with the
tubercles of the atlas and of some caudal vertebree

and the chevron bones. The dorsal surface bears a
median series of spines, which are longest in the -

anterior dorsal and lumbar vertebrae. ‘They are
variously directed, as has been already described.

On each side of the series of spinous processes
are the neural lamin forming the bottom of the
“vertebral grooves,’ each of which is bounded ex-
ternally by the transverse, zygapophysial and
metapophysial processes, and internally by the
spinous processes. Each groove is broad and
shallow in the neck, and deeper and narrower
in the anterior thoracie region, and deepest of
all at the lumbar region. The lamine overlap in
the neck and in the anterior and middle part of
the dorsal region. They leave an open space
between them in the lumbar portion of the ver-
tebral column. ’

CHAP. III. ] SKELETON OF THE HEAD AND TRUNK. 49

§ 14. Having considered the dorsal part of the axial skeleton—
the backbone—we may now proceed to consider that opposite, or
ventral structure, the BREASFBONE, together with those parts (the ribs,
with their cartilages), which connect the backbone and breastbone
together. The breastbone and ribs, with the dorsal vertebra, to

Fig. 24.—SKELeTON oF THE THORAX.

x. Xiphoid process.

c. End of xiphoid cartilage.
p. Presternum or manubrium.

ca. One of the costal cartilages.
m. Sternebre of body of sternum )

which the ribs are dorsally attached, together constitute the skeleton
of the thorax. The thoracic part of the axial skeleton thus forms a
sort of bony cage in which, during life, those most important organs,
_ the heart and lungs, are sheltered and protected.
§ 15. The breastbone, or sTERNUM, extends along the ventra
E

a oe
is gf Si
4 oe ent)
a
{ aw
7 ‘

50 THE CAT. [CHAP. IIT,

portion of ‘the trunk in the middle line, but it is very much smaller
and less complex than is the backbone. It is flattened from above
downwards, but still more so from side to side, and consists of a chain
of eight bones, called sternebre, about fifteen or sixteen times as long
as broad, but its width varies slightly at intervals throughout its
whole extent.

The sternum is connected on each side with the cartilages (ca) ot
the first nine ribs, one cartilage on each side being attached to each
successive pair of sternebree at their junction, as well as to the side
of the manubrium and the hinder end of the seventh sternebra. x

The first sternebra, which ends auteriorly in a laterally compressed
pointed process (p), 1s called the manubrium, or presternum, and
extends forwards in front of the insertion of the cartilage of the first
rib. The second part (or the body of the sternum) is made up of all :
the other six sternebre together. The third part (a) is the wiphoid, ;
or ensiform, process, which varies in shape in different individuals,
and long remains cartilaginous. The hinder end of the manubrium
affords a surface for the attachment of the second costal cartilage.

The first sternebra of the body completes the surface for the
second rib. The notches for the third, fourth, fifth, sixth and
seventh ribs are situated at the lines of junction of the sternebree ot
the body of the sternum—as before mentioned. The notches for the
eighth and ninth rib cartilages are placed close together at the
hinder end of the seventh sternebra (see below, Fig. 78, B, /).

This xiphoid cartilage projects freely backwards, tapering towards
its generally more or less expanded and fan-shaped distal end (¢).

§ 16. The rips (coste) are long, slender, curved bones, which

extend obliquely downwards from the spinal column, and end below
in cartilaginous prolongations called costal cartilages. Someofthese
join the sternum by their cartilages (Fig. 24, ca), and others do not. :

There are thirteen ribs on each side. The nine anterior ribs on
each side are called “true ribs,” and join the sternum by their
cartilages. The four hinder ribs do not join the sternum, and are
therefore called ‘“ false ribs.” The ribs generally are curved at
first (starting from their attachments to the vertebral centra) out-
wards and a little upwards, then backwards, and outwards and
much downwards. |

Taking the stxTH RIB as a type, the following points may be
noted : its proximal or upper and inner end is thickened, and is
called the capitulum, or head, of the rib (c), and it is this which
joins the capitular surfaces of the fifth and sixth dorsal vertebrae by
two corresponding oblique articular surfaces, with a ridge between. F
The part of the rib next to the head is termed the neck (n), and 4
this short portion terminates at what is called the tuberculum (2), or
tubercle of the rib. This is a rounded prominence on the hinder
border of the bone. It looks upwards, and presents a smooth
surface for articulation with the transverse process of the sixth }
dorsal vertebra; outside this smooth prominence is a rough surface
of bone. The neck of the rib is narrower than is the first part

ae

CHAP. III. | SKELETON OF THE HEAD AND TRUNK. 51

of the “body,’—the “body” of the rib being all that portion

which is distal to, or beyond, the tubercle. This body (0d) is

somewhat flattened from before backwards at its upper part, and
slightly expanded in the same direction at its distal end, the in-
tervening part being nearly cylindrical. It exhibits a faint indication
of a groove running along its hinder side, especially at the upper
part of its body. A little beyond the tubercle the bone makes a
sudden bend downwards (a). This part is termed the angle, and
it is behind it that the groove just mentioned is most distinctly
developed, while in front it exhibits a roughened line for muscular
attachment.

The distal end of the bone is hollowed out into un oval pit (p),
and into this the sixth costal cartilage is inserted.

Fig. 25.—S1pE Vinw oF RIBs.

A. First rib. | c. Capitulum.

B. Sixth rib. n. Neck.

C. Thirteenth rib. p. Pit for costal cartilage.
a. Angle. | t. Tuberculum.

bo. Body.

The other true ribs differ but slightly from the sixth, except as
to length, which decreases as we pass forwards or backwards from
the ninth, which is the longest rib.

The first rib is the broadest of all (Fig. 25, A), especially towards
its proximal end. Its capitulum has but one articular surface. The
“angle” about coincides in position with the tuberculum.

The false ribs decrease in length backwards, but the last rib is
longer than even the fourth true rib.

The three foremost false ribs (the tenth, eleventh and twelfth)
are united together by their costal cartilages, but the thirteenth
rib ends freely, and is thence termed a floating rib. The last rib
(Fig. 25, C), has but a minute rudiment of a tuberculum or none,
and the capitula of the last three ribs have each but one articular

surface.
E 2

52 THE CAT. (CHAP. III.

The angles of the ribs become more and more distant from the -
tubercula as we pass backwards to the eleventh rib. The thirteenth
exhibits no angle. :

§ 17. The cosTaL cARTILAGES (Fig. 24, ca), differ much as to
length, connexion, shape and direction. The tenth is the longest,
and thence the length decreases as we pass either forwards or
backwards through the series. The first nine join the sternum.
That of the tenth rib joins the costal cartilage of the ninth rib,
and similarly the eleventh and twelfth costal cartilages unite distally ~
with the lower border of the costal cartilage next in front. The
thirteenth costal cartilage ends freely. The first costal cartilage
is the broadest, and thence they gradually narrow backwards. The
last cartilage is pointed at its distal end. The upper (proximal)
end of each costal cartilage is convex, and fits into the distal con-
cavity of its rib. As to direction, the cartilages pass at first
backwards, then downwards, curving distally forwards from the
fourth to the seventh. The first cartilage has a nearly horizontally
forward direction, while the last extends downwards and backwards.

§ 18. The rHoRAx as A WHOLE forms a long, transversely narrow,
conical case, with a small aperture in front and a wide oblique
opening behind. It is considerably deeper trom above downwards
than it is wide from side to side. The variation in its dimension,
which shows itself as we proceed, from before backwards through
the thorax, is produced by the corresponding variation in the length
of the ribs and in their curvature. The anterior opening is bounded
by the first pair of ribs, the first dorsal vertebra and the manubrium.
The posterior opening is bounded by the xiphoid process, the cartilages
of the four hindmost ribs, the body of the thirteenth rib and the
thirteenth dorsal vertebra.

§ 19. Such being the structure of the bony and cartilaginous parts
which make up the spinal portion of the axial skeleton, we have
next to consider the fibrous bands, or LiGAMENTs, which hold together
the bones and cartilages already described. The substance inter-
posed between each pair of true vertebree is an elastic body termed
an intervertebral dise. |

Each such disc is made up of concentric lamelle (Fig. 26, /), of
fibro-cartilaginous and fibrous tissue, surrounding a soft central por-
tion (g), which is very elastic (projecting beyond the general level of
the dise when pressure is removed) and contains numerous nu-
cleated corpuscles like those of cartilage.

The surface of each centrum is covered (except towards its cir-
cumference) with a thin layer of cartilage, and it 1s to it that the
intervertebral discs are attached.

These discs form so many elastic pads, and one such is placed
between each pair of presacral vertebra, except between the atlas :
and the axis. |

A strong band of fibres, called the ventral common hgament, extends
along the ventral surface of the vertebral bodies. It is thickest
where it passes over the middle of the centra than elsewhere, and

OHAP, III.] SKELETON OF THE HEAD AND TRUNK. 53

thus tends, by fillmmg up depressions, to render the surface of the
vertebral column more even.

Another band of fibres, called the dorsal common ligament, passes
backwards within the neural canal along its ventral surface from the

_ skull backwards.

Each pair of articulating zygapophyses is surrounded and. enclosed

by a fibrous bag, the fibres passing from one zygapophysis to the

other. Such a surrounding and enclosing membrane is termed a
capsular ligament. Enclosed within the capsular ligament is a

Fig. 26.—INTERVERTEBRAL Discs.

A. Surface view enlarged.
B. Section through two discs.
f. Lamelle.

g. Soft central portion.
2. Interspinous ligaments.

membrane which secretes an albuminous fluid termed synovia.
Membranes of the kind are therefore termed synovial, and are
placed between hard parts which are destined to move one on the
other. Synovial membranes will be more fully noticed in the deserip-
tion of the different kinds of joints at the end of the next chapter.

Certain ligaments with much yellow elastic tissue, called the. Ziga-
menta subflava, pass between the neural lamina, being attached to the
inner or ventral surface on one neural lamina and thence passing
backwards to the anterior margin of the neural lamina next behind.
They are thus best seen when the neural arches are removed and
viewed on their ventral aspect.

54 THE CAT. [CHAP. III.

Adjacent spinous processes are also connected together by mem-
branes (Fig. 26, B, 2), called interspinows ligaments. Narrow bundles.
of fibres, forming a sort of cord, pass backwards along the spinous
processes. ‘These are the supraspinous ligaments. 4

A forward prolongation of these supraspmous ligaments is termed ;
the igamentwm nuche, and passes from the cervical neural spines to
the skull. |

Adjacent transverse processes are also connected together by
fibrous bands termed the inter-transverse ligaments. These are
largest in the lumbar region, while they are rudimentary in the
vertebree of the neck.

The mobility of the spmal column is different in different regions,
being greatest of course in the tail (save in some breeds), which can
be bent freely in any direction owing to the absence of interlocking
bony processes, except in the most anterior caudal vertebra. After
the sacrum, the mobility is least in the dorsal region, on account of
the overlapping of the neural lamine. In the cervical region there
is much mobility, even apart from the axis and atlas, the motions of
which will be treated of separately. Lateral bending and rotation
are variously limited by the direction of the articular surfaces of the
zygapophyses, which, as has been noted, are different in different
regions.

§ 20. The axis and atias articulate together in a manner
altogether peculiar.. The atlas (with the head to which it is attached)
can turn round to a great extent in either direction upon the odon-
toid process as on a pivot, being retained in place by ligaments.
Synovial membranes are interposed between the articular surfaces of
the atlas and axis, which surfaces are kept in apposition by capsular
ligaments.

The odontoid process is kept in place by the transverse ligament
of the atlas, which extends across above that process and between
the internal margins of the anterior articular surfaces of the atlas.
From the midst of this transverse hgament two bundles of fibres
are given off in opposite directions, one bundle passing backwards
to the centrum of the axis, the other forwards to the skull, thus
giving rise to the figure of a cross. 3

A synovial membrane is placed both above and below the odontoid
process, corresponding with the two smooth surfaces which have
already been noted as existing upon it. |

Three ligaments pass forwards from the odontoid process to the
skull, z.e., one from its tip to the margin of the opening of the skull
in front, and two others (called alar or check hgaments) from the
sides of the summit of the process to the mside of the condyles of
the skull.

These crucial and odontoid ligaments are covered over above and |
sheltered by another called the occipito-awial ligament, which is
placed in the ventral part of the neural canal between them and the
most anterior part of the dorsal common ligament. It passes up
from the centrum of the axis to the inside of the floor of the skull.

}
4
g
«

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. 55

Another ligament, the ventral occipito-atlantal ligament, passes
from the front ventral border of the atlas forwards to the adjacent
part of the skull, and similarly the ventral atlanto-axial ligament
connects the ventral arch of the atlas with the centrum of the
axis. Certain other ligaments connect together the neural arch of
the atlas with that of the axis and with the skull. The first of
these is the dorsal atlanto-axial ligament, connecting the neural
arches of the axis and atlas. Another is the dorsal occipito-atlantal
ligament (Fig. 27, +), which connects the neural arch of the atlas
with the adjacent margin of the posterior aperture of the cranium.
A third ligament, the transverse atlanto-occipital (°), passes outwards
upwards and forwards on each side from the neural arch of the atlas
to the inner side of the adjacent occipital condyle. Yet another liga-
ment may be called interspinous. It connects the neural spine of the
axis with the middle of the dorsum of the neural arch of the atlas.

§ 21. As to the ribs, a ligament, named “ sted/ate,” passes, in a

S

ra . \\Y
WW”

Fig. 27.— LIGAMENTS OF ATLAS AND AXIS,

4, Rectus lateralis muscle.
5. Transverse atlanto-occipital ligament.
so. Supra-occipital.

1. Dorsal occipito-atlantal ligament.
2. Dorsal atlanto-axial ligament.
3. Interspinous ligament.

radiating manner, from the ventral surface of the head of each rib
on to the intervertebral substance opposite to it, and on to the bodies
of the two adjacent vertebre.

Another ligament, named inter-articular, passes transversely from
that ridge on the head of the rib which divides its two articular
surfaces, to the intervertebral substance. This ligament of course
does not exist in the articulations of the first, eleventh, twelfth, and
thirteenth ribs, which have each but one articular surface.

The ribs, except the first and the last three, are also connected
with the transverse processes, each by certain other ligaments; but
none of these attachments prevent each rib from performing a slight
movement backwards and forwards upon its vertebral attachment, as
well as a certain movement of rotation.

The pieces of the sternum are connected by cartilage, and bound

56 THE CAT. (CHAP. mn

together both in front and behind by ligamentous fibres, and such
fibres surround the articulations of the costal cartilages with the
sternum, and thence radiate over the latter both dorsally and
ventrally. The various articulations of the ribs with the vertebree
and of the costal cartilages with the sternum, are furnished with
synovial membranes. ‘Thus a movement of the ribs backwards and
forwards alternately is facilitated, and such movements, we shall
hereafter see, are continually repeated in the process of breathing.

THE SKELETON OF THE HEAD.

§ 22. The remaining part of the axial skeleton is that familiarly

Fig. 28.—Tur SKULL, VIEWED DORSALLY.

Sf. Frontal. ° j. Post-orbital process of malar.

j. Malar. pm. Premaxilla-

l. Lachrymal . Sagittal suture.

1*, Lachrymal foramen. . Posterior pier of zygomatic arch.
la. Lambdoidal ridge. . Incisive foramen.

m. Maxillary. . Infra-orbital foramen.

n. Nasal. . Posterior palatiné foramen.

p. Palatine. . Spheno-palatine foramen.

pf. Post-orbital process of frontal.

OPES

known as the skutn. This bony structure affords shelter to the
brain, and is also the seat of certain organs of special sensation—

CHAP. II1.] SKELETON OF THE HEAD AND TRUNK. 57

namely, those of hearing, sight, and smell. It may be described
as an irregularly and complexly shaped osseous box with an arch,
like a flying buttress, on each side, all forming one coherent mass,
and with very diversely conditioned arches appended below and not
similarly coherent. ‘The first of these inferior arches is the skeleton
of the lower jaw, or mandible. The second is the bony framework
to which the tongue is attached, the hyoid. Both these inferior
arches readily fall away from the rest of the skull when the soft
parts are dissolved or otherwise removed.

Apart from these arches (both inferior and lateral) the skull
consists of a spheroidal posterior portion (p), to which is annexed
in front an elongated, narrower, and irregularly quadrilateral part,
made up of the bones of the face. On each side of the skull (just
in front of the spheroidal portion) is a large smooth concave surface
(with the concavity outwards), which forms the inner wall of the
chamber for the eye, or the orbit; and the skull is especially narrow
from side to side at the hinder and lower part of this region.

The greater part of the upper region of the skull is smooth and
even, and crossed by undulating lines of bony union called sutwres(s).

When a section is made lengthways (Fig. 49) through the skull,
its spheroidal portion is shown to bound a great posterior cavity (for
the brain), in front of which is a more solid region—the quadrangu-
lar part—which includesthe bones of the nose (Figs. 49 and 80,
me, et), and is placed above the mouth and between the eyes.

The skuil consists of two parts :—

(1). The brain-case, skuli proper, or cranium.
(2). The skeleton of the face.

Certain conspicuous openings and prominences are found in different
regions.

The projecting portion of the back of the head is termed the
occiput, and at its inferior hinder part is a large hole, looking down-
wards and backwards, termed the occipital foramen, or foramen
magnum (Figs. 29 and 47, fm). On each side of this hole, forming
part of its margin, is a rounded projection; and these projections
(Figs. 29 and 47, oc), termed “occipital condyles,” articulate with
the cup-shaped articular goncavities on the anterior side of the atlas
vertebra (Fig. 21, B, z). Thus, all but the front part of this foramen
(to which the odontoid process is attached by ligament) coincides with
the corresponding portion of the rmg of the atlas vertebra, and the
interior of the skull forms the expanded anterior end of the vertebral
neural canal.

If the skull be turned base upwards (Fig. 29) a large globular
prominence (0) will be seen a little in front of and external to each
occipital condyle. Each such prominence is called, from its connec-
tion with the internal ear, an auditory bulla. Between the bulle,
the under surface of the cranium extends forward as a narrow flat
surface (Fig. 29, bo and ps), bounded laterally by two low, elongated
bony plates (pt), external to which is, on either side, the wide cavity

of the orbit enclosed by the bony arch just referred to, which arch is

58 THE CAT. . [CHAP, III,

termed the sygoma(Z). At the hinder end of the zygoma is a traus-
versely extended, smooth concavity called the glexoid surface (9).
The under surface of the face (formed by the bones of the roof of

|
3
y
+
,
q
}
;
;
q
i
Fig. 29.—UNDER SURFACE OF SKULL 4
The two openings enclosed by the pre-maxille and maxille are the anterior palatine foramina. ;
6. Auditory bulla. pf. Post-orbital process of frontal.
bo. Basi-occipital. pj. Post-orbital process of malar
bs. Basi-sphenoid. jm. Pre-maxilla. < ;
c. Canine. pmo. Pre-molars. 2
jm. Foramen magnum. pp. Par-occipital process. foe 4
g. Glenoid surface. ps. Pre-sphenoid. 1
4. Incisors. pt. Pterygoid process.
j. Malar- so, Supra-occipital. :
m. Maxilla. Z. Posterior root of zygoma. c
mo. Molar. 8. Palatine foramen. :
ms. Mastoid process. 8. Sphenoidal fissure and foramen rotundus. ‘
oc. Occipital condyle. 9. Foramen ovale. ’
pp. Palatine (placed one above, the other be- 10. Eustachian opening. "
neath the opening of the posterior nares). 11. Foramen lacerum posterius. ;
j
the mouth) lies at a slightly different level from that of the base of ‘
the cranium. The two low, elongated bony plates (pt) just spoken 4
of connect these two surfaces together on each side, but in the §

middle line, leave a vacuity between them, which is the hinder
opening of the nostrils, or posterior nares (shown, in Fig. 29, by the

Lt

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. 59

shadow in front of ps), which bounds the base of the cranium in from
as the foramen magnum bounds it behind.
The middle of the hinder part of the under surface of the face

thus forms the ventral margin of the hinder nostril, while on either

side, the face receives the termination of the arch of the zygoma.
It thence narrows as it proceeds forwards, forming a. triangular
bony plate, slightly truncated in front, and bordered by teeth.

When the skull is looked at in front, we see on each side of its
highest part, with its rounded outline (the forehead), the great

Fig. 30.—SKULL VIEWED FROM IN FRONT, WITH THE LOWER JAW DETACHED.

an. Angle of mandible. pf. Post-orbital process of frouta..

c. Canines. pj. Post-orbital process of malar.

c. (Of lower jaw) coronoid process, pm. Pre-maxilla.

J. Frontal. pmo. Pre-molars and inferior true molar.
’ 4. Incisors. y. Condyle of mandible.

m. Maxilla. 2. Infra-orbital foramen.

n. Nasal. ! 13. Mental foramen.

sockets for the eyes, termed the orbits. These are not completely
surrounded by bone, but are bounded below and externally by the
zygoma and a process(y), and above by another process (p/’) from the
skull roof, and behind by the wall of the cranium. The part of the
skull which juts out laterally to support the floor of the orbit is called
the “malar prominence.” Between the orbits is the bony pro-
minence of the nose, beneath which is a small, somewhat heart-
shaped aperture, the front bony nostrils or anterior nares.

Beneath each orbit is the small bony cheek, and the skull is

_ bounded below (the lower jaw or mandible being removed) by the

alveolar border giving attachment to the teeth.

60 THE CAT. [CHAP. mI,

When the skull is viewed in profile its upper margin is seen
to present an even, rounded contour. Its lower margin is
nearly straight, with irregular prominences. The line of the
occiput (Fig. 46, ¢ to y) inclines somewhat backwards as it
ascends. In front, the skull is bounded by the margin of the
anterior nares.

The zygoma arches upwards, backwards, and then downwards to
the front of the auditory bulla, enclosing, as well as the orbit, a
fossa named “temporal,” because a muscle called the “temporal
muscle” is there placed. Behind and beneath the hinder end of the
zygoma is a noticeable aperture, which is the external bony opening
of the ear (ae). A ridge also runs upwards from the malar pro-
minence, and forms the anterior margin of the bony orbit. The
orbit is bounded behind by an ascending and a descending post-
orbital process, which nearly meet.

The skull is said to be divided into certain regions. Thus we
have the base or basi/ar region, and opposite to it the vertex, or

———

sincipital region; we have the region of the forehead, or frontal,
region, and opposite to it that of the back of the head, or occapital

region.

ae the side of the head we have, posteriorly and above, the
parietal* region (p); beneath this, and within the arch of the
zygoma, the temporal region. |

The skull is made up of different bones of very different sizes,
shapes, and degrees of density, which are variously united together
by sutures.

When the skull is looked at from above, a transverse zigzag line
of union is seen to run across behind the forehead; this is called the
coronal suture. Its zigzag appearance is due to the interlocking of
little processes which project from the adjacent margins of the bones,
the presence of which causes the suture (or line of union) to be
what is called “‘dentated.”’ Running directly backwards and forwards
from this, along the middle line of the skull, is another suture—at
right angles to the former—termed sagittal (Fig. 28, s). The sagittal
suture ends posteriorly by joming a wide V-shaped suture with the
apex upwards, which is called lambdoidal.

Turning now to the lower jaw; this when attached to the skull
is seen to fit, by a cylindrical-shaped head, or “ condyle,” mto a
depression placed on each side in front of the external auditory
opening, the g/enoid surface before mentioned.

The number of bones forming the skull decreases with age, by
anchylosis. In its mature condition the skull of the cat consists of
the following twenty-seven bones: the occipital, two parietals, two
frontals, two temporals, the sphenoid, the presphenoid, the ethmoid
—which ten bones compose the cranium, or skull proper; two
maxillaries, two premaxillaries, two nasals, two malars, two lachry-
mals, two palatines, two turbinals, one vomer, one mandible (in twa

* Because it is here the ‘‘ parietal bone”’ is situate.

| CHAP. IIL] SKHLETON OF THE HEAD AND TRUNK. 61

parts), and the hyoid bone*—seventeen bones in all, form the
skeleton of the face. :

§ 28. The occrPiraL BovE is of course that of the occiput, and it
surrounds the great occipital foramen, or foramen magnum (fm).
When detached, it is seen to be somewhat lozenge-shaped, but
rounded above and truncated below. It is made up of a crescentic
plate of bone extending above and beside the foramen magnum, and
of another narrower aud quadrangular plate of bone, which, joining

Fig. 31.—THE OCCIPITAL.

A. External surface, eo. Ex-occipital.

B. Internal surface. fm. Foramen magnum,
bo. Basi-occipital. i. Lambdoidal ridge.

c. Condyle. p. Par-occipital process.
cb. Cerebellar fossa. so. Supra-occipital.

the other, bounds the foramen magnum below, and thence extends
forwards.

The part above the great foramen (so) is the supra-occipital bone,
while the parts placed one on each side of it (eo) are the ex-occipitals,
the quadrangular plate in front (bo) is the bast-occipital, and these
four are all separate and distinct bones in the young kitten.

The margin of the supra-occipital projects outwards as a bony
ridge (7), which descends on each side of the occiput, and is called
the lambdoidal ridge or occipital ridge, and affords a special surface
for muscular attachment. The outer surface of the supra-occipital
is undulating and more or less convex. Its inner surface presents
shallow depressions or fossee, one of which (cd) is placed medianly
above the foramen magnum, and lodges the middle portion of that
part of the brain called the cerebellum.

The basi-occipital narrows somewhat as it advances forwards. Its
upper surface exhibits a smooth concavity, the basilar groove, which
supports that part of the nervous centres termed the “medulla
oblongata.”

Each part of the bone which bounds the foramen magnum on
each side, i.e., each ex-occipital, supports one of the condyles before

* Really made up of several distinct bones ; but here, for the sake of simplicity
and clearness, spoken of as one.

62 THE CAT. [CHAP. III, °

noticed. The condyles (c) are elongated convex prominences placed
somewhat obliquely, converging forwards. The imner border of
each is rough, for the attachment of one of the “ check” ligaments.
In front of each condyle is a perforation, the anterior condyloid
foramen (1), which allows the hypoglossal nerve
to pass out from the brain, while a canal (the
hinder opening of which is a little within the
margin of the foramen magnum) traverses the ex-
occipital on its mner aspect. External to each
condyle is an expanded process of bone called the
par-occipital process (p), the front surface of which
is applied to the posterior surface of the auditory
bulla. The root of the par-occipital process forms
the hinder boundary of the aperture of the skull
through which the jugular vein comes out, which
aperture is called the foramen lacerum jugulare, or
foramen lacerum posterius.

A small triangular bone, the INTERPARIETAL, in

Fig. 32.-—INTER-

PARIETAL Bone, the fully mature cat blends completely with the
at he ae supra-occipital, but long remains a distinct ossicle.

«. Apex which Its base is applied to the mid-part of the superior

passes forwards

between the pa- _ border of the occipital, while its sharp apex extends
b. SEE EEN forwards between the parietals. It is strongly con-
. Fossa for recep. cave within (especially in the transverse direction)
ion of part of - ‘
brain. but is convex externally.

If this be counted as a part of the occipital,
that bone may be said to articulate above by its superior margin
with the parietals, and below this, on each side, with the hinder
margin of one of the temporal bones, while each par-occipital
process (as before said) applies itself to the hinder end of one of the
ordinary bulle. The basi-occipital adjoms the hinder part of the
bone next in front, namely the sphenoid.

§ 24. The parierat bone forms, with its fellow of the opposite
side, the main part of the roof of the cranium. It would be
quadrangular in figure but that its upper, hinder angle is rounded
off, and it is strongly convex outwards, and concave within. Its
greatest convexity is termed the parietal eminence(e). Above this is a
curved ridge convex upwards, marking the superior limit of the
temporal fossa. Within, the parietal is marked by grooves for
blood-vessels, and its upper margin is traversed by a longitudinal
depression, which forms, with the help of the opposite parietal, a
longitudinal wide and shallow groove for a blood receptacle called
the longitudinal sinus. The two parietals are connected together
above by the sagittal suture; each is connected by the lambdoidal
suture with the interparietal, and with the supra-occipital. The
parietal also articulates anteriorly (f) with the frontal by the

* It has not therefore been reckoned as a distinct bone in the list before given
of the bones of the cranium and face.

CHAP ‘II.] SKELETON OF THE HEAD AND TRUNK. 63

coronal suture, and below with the temporal bone by a suture (sq)
which is called squamous, because-the margins of the bone it joins
are so bevilled off that the temporal lies on the parietal like a scale.
From the hinder margin of the parietal a plate of bone extends for-
wards at an acute angle, with a strongly concave free margin. This
plate divides one part of the brain from another, and is en ossifica-

Fig. 33.—RiGHT PARIETAL BONE.

A. Internal surface. f. Surface for articulation with frontal.
B. External surface. ; sq. Surface for temporal bone.
e. Parietal eminence. t. Tentorium

tion of a membrane called the tentorium, and described with the
brain structures (¢). The parietal is always a single bone. :

§ 25. The remaining bones of the roof of the skuil are the
FRONTALS, which lie side by side in front of the parietals, and roof
over the hinder part of the face as well as the front part of the
cranium. The suture which divides them is termed the “ frontal

Fig. 34.—THE FRONTAL.

A. External aspect. op Orbital part of lateral plate.
B. Internal aspect. tp. Temporal part of lateral plate.

fu. Outer wall of nasal fossa. po. Post-orbital process.

Jf. Surface joining the other frontal. | . Pre-orbital process.
m. Nasal process. :

suture,” and is the direct continuation forwards of the sagittal suture.
The frontals together form a considerable, rather convex triangular
expansion above, the outermost part of which is the post-orbital
process (po) of the hinder part of the orbit; while behind this the
frontal forms part of the temporal fossa.
But the greater part of each frontal is its lateral part (op), which
descends from the outer margin, almost at right angles with its

64 : THE CAT. | [ CHAP. III,

upper surface, as an undulating plate (concave externally in front,
and convex behind) with a crescentic inferior margin. The hinder, .
externally convex, part of this plate forms part of the temporal
fossa; the anterior, externally concave, part of it forms the inner

wall of the orbit, and (towards its front end) the outer wall of the

nasal cavity.

Viewed internally, each frontal shows above, a flattened surface (/)
for junction with its fellow of the opposite side; behind this is a
deep concavity for part of the brain, and in front, a flattened and
irregularly roughened surface (f)—the outer wall of the hinder
part of the nasal cavity. :

Thus, the two frontals together have, when viewed from below,
somewhat the figure of a bisected hour-glass. There is, behind, a
large conical cavity (with the apex forwards) for the brain, while
in front is a smaller conical cavity (with the apex backwards)—the
nasal chamber. Consequently, when the two frontals are seen together
from behind, they exhibit a deep median notch, open below, indi-
cating the point of communication between the anterior and posterior
conical cavities just mentioned, and situated at the point where each
frontal is laterally constricted. This notch, in the perfect skull, is
filled up by a bone called the ethmoid, which forms the hinder end
of the nasal chamber. At its anterior end, each frontal bifurcates
laterally into a sharp pointed “nasal process” (m) and a more obtuse
‘‘pre-orbital process’? (p). Between these processes each frontal
recelves an ascending process of the maxillary bone. While the
two nasal bones are received between the slightly diverging nasal
processes of the two frontal bones (see Fig. 28). .

‘Within the substance of the middie upper part of the bone is a
cavity, more or less filled with air, called the frontal sinus, which
cavity is prolonged out into the post-orbital process. 3

The frontals articulate behind, with the parietals; laterally, with
the orbito- and ali-sphenoids, and sometimes also with the temporals;
below with the palatines, the maxiliaries, the ethmoid, and the lachry-
mals ; in front, with the maxillaries and nasals.

§ 26. On each side of the hinder part and base of the cranium
we find an exceedingly complex bone, called the remporaAL. When
looked at externally it exhibits a very conspicuous oval opening (the
meatus auditorius externus), which is the aperture (me) leading from
without to the internal ear. From in front of this a bar of bone,
the zygomatic process (z), arches horizontally forwards and outwards,
and contributes, with the large plate of bone above it(sq), the
squamous element of the temporal bone, or the ‘‘ squamosal.” This
bony plate is convex without and concave within, and with a very
rounded superior margin, which overlaps the lower part of the out-
side of the parietal bone above.

The zygomatic process is somewhat arched vertically, and is bevelled
off at its distal end, which lies upon the malar bone. At its hinder
end this process has beneath an elongated surface, concave from
before backwards, and termed the glenoid surface (g).

CHAP. III] SKELETON OF THE HEAD AND TRUNE. 65

Tn its natural state it is coated with cartilage, and serves for the
articulation of the lower jaw. ‘This surface is limited behind by a
sharply descending bony plate—the post-glenoid process (gp). A
ridge of bone is continued backwards from the hinder end of the
zygomatic process, over the external auditory meatus, and is called
the posterior root of the zygoma, the part supporting the glenoid
surface, forming the anterior root of the zygoma.

The bone which bounds inferiorly the external auditory opening
is that which forms the auditory bulla already spoken of. This is
rounded, and smooth on the surface, and rather longer from before
backwards than transversely. It is at first made of two parts: an
external part, consisting of a crescentic plate of bone, broader
in front than behind—the tympanic (so called on account of its

Fig. 35.—TEMPORAL Bone.

A. External view. ms. Mastoid process.

B. Internal view. p. Surface applied to parietal.

b. Inner and larger part of bulla. sq. Squamosal.

eb. Cerebellar fossa. é Outer and smaller part of bulla.

eu. Eustachian opening. xz. Aqueductus cochlez.

g. Glenoid surface. z. Zygomatic process.

gp. Post-glenoid process. 12. Stylo-mastoid foramen.

m. Mastoid region. A process of the malleus is seen in Fig. A, ex-
me. Meatus auditorius externus. tending downwards and forwards within the
mt. Meatus auditorius internus. auditory meatus.

connexion with the drum of the ear)—and an internal, much wider
part—the ento-tympanic—which forms all the rest of the bulla,
which is naturally visible on the base of the skull.

Between the anterior end of the tympanic and the post-glenoid
process is a narrow chink, termed the jfisswra Gilaseri, which transmits
the chorda tympani nerve.

At the hinder end of the tympanic, beneath the posterior end of
the posterior root of the zygoma, is an opening (12), called the sty/o-
mastoid foramen, which gives exit to the facial nerve. Immediately
below and within this foramen there is a small pit in the tympanic,
at the bottom of which a minute cylindrical ossicle, called the
tympano-hyal, may be detected, which serves to give attachment to
the uppermost and cartilaginous portion of the anterior, or lesser
cornu of the hyoid (Fig. 46, ¢*).

The only remaining part of the temporal bone visible externally

is a very small and narrow triangular tract, which extends upwards
F

66 THE CAT. [CHAP. II, | 4

and backwards (its apex being above) from above the stylo-mastoid
foramen and behind the posterior root of the zygoma. It is rough
externally, and forms the lower part of the lambdoidal ridge, the
upper part of which is formed by the occipital bone. Opposite the
posterior root of the zygoma it adjoins the par-occipital process, and
below that pomt of junction it narrows into a nipple-shaped process
applied externally to the tympanic, and descending, immediately
behind the stylo-mastoid foramen, to the pit for the tympano-hyal.
This triangular tract is the mastoidal region (m) of the temporal
bone, and the process just described is the mastoid process (ms).

On its inner aspect, below and behind the squamous part (sq),
the temporal bone exhibits a triangular irregularly-shaped mass of
very dense osseous tissue. This is the petrous part of the temporal
bone, or the “ petrosal.” The petrous and mastoidal portions of the
bone enclose the inner and essential parts of the ear, the interna
canal leading to which—the meatus auditorius internus—is the con-
splcuous opening seen on the inner surface of the petrosal (mi).
This opening is divided within by a horizontal bony lamella into
two parts. ‘The openings for the auditory nerve filaments are below
this horizontal lamella, while the opening above it gives entrance to -
the facial nerve, which thence proceeds to the stylo-mastoid foramen,
traversing in its way a canal termed the Aqueduct of Fallopius.

Above the opening of the internal auditory meatus there is, on
the inner wall of the petrosal, a depression or pit (cb), (which
lodges a process of the cerebellar part of the brain) surmounted by
a prominence which indicates the place of the anterior vertical
semi-circular canal of the internal ear. Below and in front of this
prominence is a small foramen, the hiatus Fallopii, which transmits
the superficial petrosal nerve, and leads back into the Aqueduct of
Fallopius already mentioned.

Just behind the shallow depression above mentioned, and close to
the posterior margin of the petrosal, is a small vertically elongated
opening, called the agueductus vestibuli. A still smaller aperture
placed close to and directly behind the internal auditory opening (a)
is the aqueductus cochlee. Both these openings transmit small
veins of the internal ear.

Between the anterior part of the petrosal bulla and the ali-
sphenoid is a largish opening (ew), which is that of the Hustachian
tube—a channel serving to convey air from the mouth to the ear.
The inner part of the canal is completely partitioned off by a small
bony lamella—(the processus cochleariformis). This rather con-
siderable Eustachian aperture is naturally roofed over and covered
by a backward expansion of the alisphenoid. On the inner side
of it, at the hinder portion of the junction of the squamosal and
petrosal portions of the temporal bone, on its inner surface, is
a groove which receives a venous canal, namely one of the two
branches into which the median venous channel (before noticed

as passing along beneath the median junction of the parietals)

divides as it descends. This groove may lead into a canal opening

cHAP. m.] SKELETON OF THE HEAD AND TRUNK. 67

by a foramen just behind the post-glenoid process—a post-glenoid
foramen. This, however, is generally absent.

The margin of the petrosal, above the cerebellar fossa and
internal meatus, developes a bony ridge, which unites with the
tentorial plate, before described as passing downwards and forwards
from within the parietal.

The cavity of the bulla is almost completely divided within into
two very unequal parts by a bony septum which ascends from the

= ON Say,

all:
<6 I,
Na 2

< Ww
hy

,

Fig. 36.—VerTIcAL SECTION OF THE AUDITORY BULLA OF THE TIGER (Flower).

am. Meatus auditorius externus. s. The septum.

BO. Basi-occipital. Sq. Squamosal.

e. Eustachian canal. t. Tympanic ring.

ic. Inner chamber of bulla. * The aperture of communication between the
oc. Outer chamber of bulla. two chambers.

pt. Promontory of petrosal.

floor of the bulla. The outer and anterior chamber is much the
smaller. Itis the true tympanic chamber, and has on its outer
wall a horseshoe-shaped prominence and groove—the tympanic ring
—to which the tympanic membrane (or membrane of the drum of
the ear) isattached. It also contains three very small and irregularly-
shaped bones: (1) the malleus; (2) the incus ; and (3), the stapes,
which stretch across from the inside of the tympanic membrane to
the opposite wall of the petrosal, and are known as the auditory
ossicles—ossicula auditis—and will be described together with the
organ of hearing.. A long process (munubrium) of the malleus is
conspicuous (see Fig. 35, A), passing downwards and forwards from
the upper part of the tympanic cavity. Also the Eustachian tube (e)
opens into this same outer chamber, superiorly and anteriorly, while

towards its hinder margin are two holes placed one above another,
. ; F 2

/

68 THE CAT, % 3)? [cHAP. mm,

situated in the wall of the petrosal, opposite the tympanic membrane.
The upper, more anterior, and smaller of these is called the fenestra
ovalis, the lower and more posterior is the fenestra rotunda. It is
through these that the really internal ear (a complex membrane
which is lodged in a correspondingly complex bony envelope within
the petrosal) is placed in communication with the exterior (Fig. 187).

The internal, posterior, and much larger chamber, is entirely closed,
save that a small opening (Fig. 36, *) is left between the hinder part of
the top of the septum close to the fenestra rotunda, so that this fenestra
may be said to open into the inner as well as the outer chamber.

In front of the fenestra rotunda is a bony prominence, caused by
the presence within it of a part of the internal ear called the cochlea.

Fig. 37.—THE SPHENOID.

A. Under surface. ps. Pre-sphenoid.

B. Upper surface. pt. Pterygoid plate.

ac. Anterior clinoid process. 7. Rostrum.

as. Ali-sphenoid. 7. Optic foramen.

bs. Basi-sphenoid. 8. Foramen rotundum.

ep. Clinoid plate. - | 9. Foramen ovale.

hp. Hamular process. The anterior and posterior portions are repre-
os. Orbito-sphenoid. sented as separated, and thus the sphenoidal
7. Ethmoidal process. fissure (which is defined by their junction)
pf. Pterygoid fossa. is not indicated.

This prominence is called the “ promontory ”’ (pt). Above it, and in
front of the fenestra ovalis, is a pit, or fossa, within which arises a
small muscle called the Stapedius. 7

The temporal bone, as has been said, is really made up of several
bones anchylosed together, which were at first distinct.

Thus we have (1) the squamosal (sq), with its zygomatic
process (); (2) the tympanic, which forms the outer chamber of
the bulla (¢); and (3) the entotympanic, which forms the imner
chamber of the bulla (+); and (4) the minute tympano-hyal.
Besides these four elements three other distinct ossifications extend
and coalesce to form the petrous and mastoid portions of the temporal
bone, and are distinguished by their diverse relations with parts of

CHAP. III.] SKELETON OF THE HEAD AND TRUNK 69

the internal organ of hearing. Continuing our enumeration, we have
(5) an ossification which gives rise to the upper part of the petrous
portion (that which is visible inside the skull), and to part of the
mastoid. It forms the upper margin of the fenestra ovalis, and is
especially related to the anterior vertical semicircular canal. It is
called the Pro-otic. We have next one (6) which gives rise to the
lower part of the petrosal (that concealed by the auditory bulla),
which forms the lower part of the fenestra ovalis, and surrounds
entirely the fenestra rotunda. It is called the opisthotic. Lastly,
we have an ossification (7) which gives rise to the mastoid process,
and which is developed upon the hinder part of what will be here-
after described as the posterior vertical semicircular canal of the
internal ear. This ossification is named the epiotic. The whole of
these, 7.e., the petrous and mastoid portions taken together, are
known as the “periotic.”” The temporal bone articulates with the
occipital behind, with the parietal above, in front, with the
sphenoid, and (through the zygomatic process) with the malar.
The apex of the petrosal is wedged in between the basi-occipital and
the sphenoid.

§ 27. The sPHENOID is also a very complex bone, and consists of
two distinct parts,* one anterior, the other posterior. The posterior
sphenoid may be first described. This is the central bone of the
base of the skull, and its median part, or body, called the basi-
sphenoid (bs), joins the basi-occipital behind. It has on the middle
of its upper surface a shallow pit called the sed/a turcica, or pituitary
fossa, because it receives and supports an appendage of the brain,
called the “pituitary body.” This fossa is bounded behind by a
small plate of bone (cp), which is inclined forwards as well as
upwards, and the hinder surface of which is continuous with the
upper surface (or basilar groove) of the basi-occipital. The plate is
ealled the clinoid plate, and its two upper angles are produced
outwards into prominences termed the posterior clinoid processes.
Beneath, the basi-sphenoid is nearly flat, and becomes narrower as
it advances forwards. Its structure is solid, not containing air-
cavities. .

On each side of the basi-sphenoid there projects outwards a large.
erescentic plate of bone, concave above from behind forwards (as),
which is its longest dimension. This is the ali-sphenoid, or great wing
of the sphenoid, and it forms the side wall of the cranium, imme-
diately in front of the squamosal and auditory bulla. Its upper
margin is concave, the lower margin of the squama of the temporal
bone being received into its concavity. Its hinder end overlaps the
petrosal (helping to close the large aperture in which the Eustachian
tube ends), and meets the anterior end of the ossified tentorial plate
of the parietal. Its anterior end ascends behind the frontal, towards
or to, the parietal. The ali-sphenoid is perforated on each side

* It is described here asa single bone, because it is so considered in human
anatomy.

70 THE OAT. [cHAP. 1m,

by two foramina. The hinder and outer of these, which is the ~

larger, is the foramen ovale (9), and transmits the third division of
the fifth nerve. Immediately in front of this is a smaller opening,
the foramen rotundum (8), which transmits the second division of
the fifth nerve. Immediately in front of this again is a large and
deep notch which, in the complete skull, is bounded in front by the
hinder margin of the anterior sphenoid, and so is converted into a
foramen. This aperture is called the sphenoidal fissure. It transmits
the first division of the fifth nerve, together with the nerves of the
orbit to be hereafter described. The upper surface of the posterior
sphenoid exhibits, on each side of the sella, a faintly-marked groove
(for a cranial artery) ending posteriorly in a notch. The piece of
bone immediately external to such groove and notch (between the
basi-sphenoid and the greater part of the ali-sphenoid) is called the
lingula sphenoidalis, and is at one time of life distinct.

Extending forwards much in front of the basi or ali-sphenoids

are two complex bony plates which extend forwards and downwards —

from the junction of the basi- and ali-sphenoid on each side, and also
join the palatine bones in front. Each of these is termed a pterygoid
plate (pt) and its flattened upper surface articulates with the under
surface of the anterior sphenoid. The under surface of this flattened
part forms part of the basis craniu, and towards its outer margin a
lamellar process of bone projects downwards, having at its hinder
end a curved sharp-pointed process (the hamular process) arching
backwards and somewhat downwards and outwards. Externally
to this hamular process, the pterygoid plate sends outwards another
small, more or less lamellar process. The very small space in-
cluded between this last and the hamular process, is called the
pterygoid fossa (pf), and there is of course one on each side of
the skull. The very considerable space included between the two
pterygoid plates is called the meso-pterygoid fossa, and that is single
and median. The part which immediately supports and forms each
hamular process, 1s originally a distinct bone, called the vterygoid bone.

The anterior sphenoid is much longer in proportion to its width than
is the posterior, but like it consists of a median part with two wings
or lateral expansions. The median part, called the pre-sphenoid (ps),
joins the basi-sphenoid behind. It is not solid, but contains a great
air-cavity, divided by a median septum into two “ sphenoidal sinuses,”
which open widely at their anterior end (the bone expanding
anteriorly into two ethmoidal processes (p) ), to embrace the lower
posterior angle of the ethmoid. The pre-sphenoid bears a median
inferior ridge, the rostrum (r), which is visible between the inner
margins of the two pterygoid plates of the posterior sphenoid. The
upper surface of the vomer is attached to the anterior part of the
rostrum. The upper surface of the pre-sphenoid is much elongated.
Its anterior two thirds support the olfactory lobes of the brain and
are convex from before backwards, but slightly concave from side to
side. Its posterior third (separated from the more anterior part by
two foramina) is slightly convex, and supports the optic nerves (where

a a ee a es Oe eee Ne Ne nO a ee ee Se ee ee

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. 71

they unite in a commissure) on what is termed the olivary eminence.
This eminence bounds anteriorly the pituitary fossa, and at each
side of its hinder margin a minute process is to be detected. These
are the anterior clinoid processes (ac). On cach side of the pre-
sphenoid there projects upwards and cutwards a short triangular z.
plate of bone (0s) called the orbital wing of the sphenoid, or orbito-
sphenoid. This is piereed at its root by a considerable opening (7),
the optic foramen, which transmits the n.rve of sight. ‘The orbito-
sphenoids form the anterior lateral part of the floor of the cranium,
projecting upwards and outwards between the frontal in front, and
the ali-sphenoid behind.

The optic foramen opens immediately in front of, and al ove, the
sphenoidal fissure and the round and oval foramina, all of which
open into the bottom and hinder part of the orbital and temporal
fossee (see Fig. 46, °, 7, §, and °).

The sphenoid considered as one whole unites with the basi-occipital,
temporal, and parictal bones behind; in front, with the ethmoid,
frontals, vomer, and palatines.

§ 28. The ETHMorD, or sieve-like bone—formed of very delicate
lamellee very much conturted—is an exceedingly complex structure
which fills up the space (incisura ethmoidalis) left between the con-
stricted parts of the two frontals, and thence extends « ownwards and
forwards into the upp*r parts of the nasal chamber, which it almost
entirely occupies. Itis thus placed between the cranium and the
face, extending forwards between the orbits and forming the hinder
wall of the nasal cavity. It consists of a median and two lateral
portions. The middle part is a simple vertical lameila of bone—the
mesethincid|Fig. 49, me), which extends forwards from the middle of the
anterior surface of another transversely extended, obliquely ascending
plate called, from the number of its foramina, © eribriform.” From
each side of the anterior surface of this cribriform plate (and on each
side, therefore, of the mesethmeid), a mass of delicate and excessively
plicated osseous tissue extends forward, bearing the name of the
lateral ethmoid or ethmo-turbinal (Figs. 49 and 50, et). The meseth-
moid has a free margin on every side except where it is anchylosed
to the cribriform plate behind. Its superior margin is adjacent to
the lower margin of the median deficcted | ortion of the frontal, and
to the inferior margin of the nasal. Its mferior margin dips down
between the ascending bifurcating lamelle of tie vemer. The
mesethmoid is much longer from before backwards than it is high.

The ETHMO-TURBINAL rises (Fig. 50, e¢) on each side considerably
higher than the upper margin of the mesethmoid, and into the
chamber formed by the nasal and nasal process of the frontal on
the imner side, and the preorbital process of the frontal on its outer |
side. It also descends slightly below the inferior margin of the
mesethmoid, and joins the ascending, diverging, superior, and
posterior part of the vomer.

The folds and grooves of the ethmo-turbinal or lateral ethmoid
proceed forwards and slightly downwards and outwards.

72 THE CAT. [cHar i) 8

Close to the upper margin of the anterior lateral aspect of the
lateral ethmoid is a small smooth, nearly triangular, surface, which
appears on the inner wall of the orbit between the lachrymal, the
frontal, and the palatine. Itis called the os planum ; the lamelle
which spring from the cribriform plate are also connected with the
os planum.

§ 29. The anterior inferior portion of the ethmoid mass (Figs. 49
and 50, m?)is really a separate bone, called MAXxILLO-TURBINAL. This
consists of other plicated delicate lamellae which proceed from the
inner surface of the maxilla. The grooves and folds of this mass
of Jamellee all proceed upwards and forwards. |

The passage between this maxillo-turbinal and the upper surface -

lll
AW
—- WAAAY NS
AON \

Nasu se
WAY AN is
oye WA
WA WE
AN

Fig. 38.—THr RicHt MAxILia.

A. External aspect. o. Sutural ridge.

B. Internal aspect. t. Tuberosity.

m. Malar process. 2. Infra-orbital foramen.
mn. Nasal process.

of the roof of the mouth is called the inferior meatus of the nose.
The passage between this and the maxillo-turbinal, and the ethmo-
turbinal, is called the middle meatus of the nose.

A passage which traverses the ethmo-turbinal on a line with the
inferior margin of the nasal bones is called the superior meatus of
the nose.

The mass of the ethmoid lies between the nasals and frontals
above; the orbital plate on the frontal, the presphenoid, the
palatine, and the lachrymal on each side, and by the presphenoid,
the vomer, and the palatines below.

THE BONES OF THE FACE.

§ 30. Having described those bones which enter into the com-
position of the brain-case, it remains to describe those of the face,
namely, the maxillary and pre-maxillary bones, the nasals, the
malars, the lachrymals, the palatines, the vomer, the mandible, and
the hyoid bone. The turbinal bones or maxillo-turbinals have
already been noticed in describing the ethmoid, of which they seem
to form the anterior, inferior portion.

i.e | a le

CHAP. III.] SKELETON OF THE HEAD AND TRUNKE. 73

The maxillary bone, or MAXILLA, 1s the largest bone of the face,
forming as it does, with its fellow of the opposite side, the main
part of the upper jaw, and supporting all the upper teeth, except
the incisors. It also contributes to form the cheek, the orbit, the
nasal passage, and the palate. The two maxillary bones do not
meet in the middle line below the anterior nares, but each sends up
a prolongation—the nasal process—(n) to the frontal. This process
bounds the inner side of the orbit anteriorly, and by its anterior
and upper margin joins the nasal bone. Its inner surface exhibits
a vertical groove, which is made into a canal by the help of the
lachrymal bone. ‘There is also on the mner surface a more or less
horizontal ridge which serves to give attachment to the maxillo-
turbinal. The superior, external part of the maxilla sends a process
outwards (beneath the orbit), which joins the malar bone, and is
therefore called the malar process (m). Superiorly the maxilla
exhibits a smooth, horizontal surface (Fig. 28, m) which forms the
floor of the orbit, and is called the orbital plate. It is traversed,
from before backwards, by a groove ending anteriorly in a large
foramen (2), which transmits the second branch of the fifth nerve,
and is called the infra-orbital fifth nerve.

On the outer surface of the maxilla, in front of the malar process,
is a slight concavity termed the “ canine fossa.’ Behind the malar
process the outer surface of the maxilla has a slightly enlarged
portion called the tuberosity (¢), which is perforated by small
foramina for the superior dental nerves and arteries. The lowest
part of the maxilla is termed the alveolar border, and is hollowed
out into the alveoli, or sockets, for the teeth. From this border the
maxilla sends inwards a large horizontal process called the palatine
plate. This is smooth and transversely concave above, but more or
less roughened and grooved below. It rises somewhat where it
meets its fellow of the opposite side in a sutural ridge (0), which
supports the vomer. The anterior margin of the palatine plate is
slightly, its posterior margin 1s deeply, concave.

The maxilla articulates with the pre-maxilla and nasal in front,
with the frontal above, and with the lachrymal, malar, and palatine
behind.

§ 31. The PRE-MAXILLA is a very small bone placed in front of
the maxilla, and joining, anteriorly, its fellow of the opposite side—
the two together forming the anterior termination of the upper
jaw. Each pre-maxilla consists of two unequal pointed processes
diverging, one upwards and one backwards, from a thickened
anterior portion which is the alveolar margin, and supports three
incisors. |

The ascending, and much the larger, process (m) mounts up in

front of, and adjacent to, the anterior margin of the ascending nasal

process of the maxilla as far as the nasal, insinuating itself between
that bone and the maxilla. The two pre-maxille bound the anterior
nares below and on each side, the nasals bounding the anterior nasal

opening above.

74 THE CAT. [ouap. ro "

From the inner side of the pre-maxilla the slender second or
palatine process () extends backwards, in contiguity with its fellow
of the opposite side, till it meets the anterior margin of the palatine
plate of the maxilla. A
notch is thus formed be-
tween this backwardly ex-
tending process and the
more external portion of
the pre-maxilla, and this

notch is converted into a
Fig. 39.—RI1GHT ee sua foramen by ihe palatine
B Ventral aspect | palatine pros, plate of the maxdilnjaeneam
it. This is the anterior pala-
tine, or incisor foramen, which is the anterior termination of the
anterior palatine canal transmitting the naso-palatine nerve.

§ 32, The mauar isa rather small, lamellar bone which forms the
most prominent part of the cheek,
the outer inferior margin of the orbit,
and the anterior part of the zygoma.
It is m the form of a curved
quadrangular plate, convex without,
concave within, and with certain
processes. Its anterior inferior
margin (m) rests on the malar pro-
cess of the maxilla. Its anterior
superior margin forms part of the
rim of the orbit. Its posterior
portion, or zygomatic process (g) is
applied beneath the lower border
of the zygomatic process of the
squamosal. Immediately in front
of the anterior end of that process

" ah oa ee the malar developes a post-orbital
BAe pier. process (p) which mounts upwards,
Be eee orbital process backwards, and inwards, towards
z. Lygomatic process. but not to, the post-orbital process

of the frontal. The postero-inferior
margin of the malar is strongly concave.

§ 33. The nasats are two elongated, small triangular bones
placed side by side above the anterior nares in front of the frontals.
Each is considerably extended vertically towards its hinder end
(B and C), and somewhat less extended transversely towards its
distal end (A). Its anterior margin is concave, its external angle (a)
being produced forwards much beyond its internal angle.

The inner side of the vertically-expanded part of the bone (B) is
flat, and applied to its fellow of the opposite side. Its outer surface (C)
is concave, and receives the nasal process of the frontal in a fossa
specially destined for it (x). The nasals join the frontals, maxille,
and pre-maxille, and form the superior margin of the anterior nares.

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. 75

§ 34. The LacHRYMALs are also very small bones, one of which
is placed at the anterior part of the inner wall of each orbit (Fig. 46,
ia), having the frontal above, the os planum behind, the nasal pro-

C

BR _A

Fig. 41.—Ricut NASAL.
A. External surface.

B. Surface turned towards the other rasa. .

C. Outer lateral surface. Ep a bicas Lace
a. External angle. A. Outer surface.

n. Fossa for nasal process of maxilla. ’ B. Inner surface.

cess of the maxilla in front, and the orbital plate of the same bone
below. Each lachrymal is marked by a vertical groove and notch (7),
which, by joining the similarly directed groove on the posterior side
of the nasal process of the maxilla, forms a foramen and canal,
called “lachrymal,” which leads from the orbit to the nasal cavity.
§ 35. The PaLatTINEs are two bones which by their median
junction behind the maxille, complete the bony palate, which, as
we have already seen, is partly formed by the palatine plates of the

Fig. 48.—RicHtT PALATINE BONE.

A. Ventral aspect. | h. Horizontal plate.
B. Cranial, or dorsal aspect. 3. Palatine foramen.
C. Anterior aspect. | 5. The spheno-palatine foramen.

a. Ascending plate.

maxille. The palatine is irregular in shape, consisting mainly of
two unequal plates, which are inclined mwards towards each other
at an acute angle—one ascending, one horizontal. The bone is
wedged in between the maxilla in front and the pterygoid behind.
It bounds the meso-pterygoid fossa laterally, and the hinder part of
the nasal cavity inferiorly ; and it forms part of the floor and of the
inner wall of the crbit.

The ascending plate (a), which is the main portion of the bone, is

76 THE CAT.

more than twice as long as it is high; but its anterior half is higher

than its posterior, and presents two foramina, one of very considerable
size, the spheno-palatine, foramen directly over a very much smaller
posterior palatine foramen (Fig. 43, B). More than the hinder half
of the inferior margin of this ascending plate is smooth, free, and
concave ; the rest of that margin joins the maxilla. Its hinder end
joins the pterygoid. The hinder half of its superior margin joins the
orbito-sphenoid and the pre-sphenoid, to which latter the concavity
its of upper margin is adjusted. Its more anterior portion is applied
against the outer side of the ethmo-turbinal. The horizontal
lamella (h) projects inwards (from the anterior two-thirds of the
inferior margin of the ascending lamella), and joins its fellow of the
opposite side in the middle line, and there also joins the inferior
margin of the hinder part of the vomer. Its anterior margin is
convex, and adjoins the hinder margin of the palatine plate of the
maxilla of the same side. Its hinder margin 1s concave and free,
forming the posterior limit of the bony palate and the anterior
boundary of the meso-pterygoid fossa. The posterior palatine
foramen (3) very near to, or at, its anterior margin.

The palatine articulates with the maxilla, the vomer, the lachry-
mal, the os planum, the orbital plate of the frontal, the pre-sphenoid,
and the orbito-sphenoid.

§ 36. The vomer (Fig. 49, v) is a single, thin, median bone

grooved above, and extending down vertically from the basi-sphenoid

Fig. 44.—Insipr oF Ricut Hair or MANDIBLE.

an. Angle.

c. Coronoid process.
ar. Ascending ramus.
hr. Horizontal ramus.

sy. Symphysis.
y. Condyle.
14. Inferior dental foramen.

and ethmoid, to the upper surface of the bony palate, thus completing
a vertical median partition between the nostrils. It is a very
long and narrow bone, very obliquely quadrangular in shape. Its
hinder portion, however, expands horizontally, to support and unite
with the inferior and hinder parts of the ethmo-turbinals—its hinder
end under-lapping the anterior part of the pre-sphenoid. In front

of the expanded part, the grooved upper surface of the vomer

receives within its groove the lower edge of the mesethmoid ; while,
still more anteriorly, the septal cartilage of the nose is received
within the same groove. The lower margin of the vomer unites

ae

Se

Ky «

TT Oe ee ee ee

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. (ii)

with the palatine plates of the maxille and palatines. Its posterior .
margin is free, and forms the hinder end of the lower part of the
internasal septum.

§ 37. The skeleton of the lower jaw, or MANDIBLE, consists of
two bones, which meet together in front at an acute angle. Each
bone, z.e., each half of the mandible, consists of two parts—its hinder,
vertically expanded portion, being called the ascending ramus (ar),
while the rest is named the horizontal ramus (hr). The horizontal
ramus is almost of the same depth throughout, and slightly curved—
its upper margin being concave, and its lower margin convex. The

latter is smooth and rounded, but the upper edge is festooned by

unequal cavities, forming sockets for the lower teeth. The place of
junction of the two horizontal rami is called the symphysis (sy), and
presents a very rough surface. The horizontal ramus begins to
expand into the ascending ramus immediately behind the last tooth,
and becomes a triangular plate of bone, concave externally, and
with three prominences, separated by two concavities, on its hinder
margin.

The highest of these prominences (which is also the highest part

of the mandible) is called the coronotd process, and is a vertical plate

of bone (c). The second prominence (separated from the preceding
by a considerable interval) is the condyle of the mandible, and is a
transversely-extended convex articular surface (y), destined to fit
into the glenoid fossa of the temporal bone. ‘The piece of bone
which immediately supports the condyle is termed the neck. The
third and lowest prominence (separated from the condyle but by a
narrow interval) is termed the angle (am), and is a small, vertically-
extended process, on a line with the inferior margin of the horizontal
ramus.

The coronoid process rises even a little more above the condyle
than does the latter above the angle, and has inserted into it the
temporal muscle.

The deep fossa outside the ascending ramus (Fig. 46, ar), the
ridge beneath it and the angle, have inserted into them a muscle,
called the masseter. The symphysis is convex and very oblique,
being inclined strongly backwards as well as downwards.

The outer surface of the horizontal ramus is convex, its inner
surface is flattened. On the inner side of the ascending ramus,
below the level-of the condyle, is a considerable foramen, called the
inferior dental (14). ‘This leads into the “ dental canal,” down which
the dental nerves and vessels pass.

At the more anterior part of the outer side of the horizontal ramus
are a pair of small foramina (Fig. 46, }°), called the mental foramina.
They transmit branches of the inferior dental nerve and artery.

Behind the symphysis, towards its lower end, is a small depression
serving for the insertion of the digastric muscle.

§ 38. The nyorp apparatus is a complex structure, consisting of
two long jointed bony bars (¢* to ch), “the anterior cornua,”’ and
two short unjointed bony bars (¢h), “the posterior cornua”—both an

78 THE CAT.

anterior and a posterior cornu springing from either end of a median
bony bar, “‘ the body of the hyoid” (bh), or basi-hyal. The basi-hyal
is a transversely-extended flattened bar of bone, which, in the

natural condition, is placed above the front part of the thyroid —

cartilage of the larynx (T). At the front margin of each end is
attached a short cylindrical bone (about half the length of the basi-
hyal), called the cerato-hyal (ch). To the end of this, is again
annexed another long bone, called the epihyal (eh), at the end

Fig. 45.—Hyoip APPARATUS, WITH LARYNX AND UPPER PART OF TRACHEA.

A. Ventral view. t*. Cartilage of tympano-hyal.
B. Lateral view. th. Thyro-hyal.
a. Connexion of thyrohyal with thyroid carti- ty. Thyro-hyoid muscle.
age. tr. Trachea.
bh. Basi-hyal. . Crico-thyroid ligament.
ch. Cerato-hyal. C. Cricoid cartilage.
ct. Crico-thyroid muscle. T. Thyroid cartilage. 5
eh. Epihyal. 1. Thyro-hyoid membrane.
s. Sterno-hyoid muscle cut short. 2. Crico-thyroid membrane.

st. Sterno-thyroid muscle cut short.

of which is another cylindrical bone, called the stylo-hyal (sh),
which is again longer than the epihyal. At the end of the stylo-
hyal is a cylindrical cartilage (¢*), which is the cartilagmous con-
tinuation of that minute cylindrical bone, the tympano-hyal, which
becomes anchylosed into the pit before noticed as existing in the
auditory bulla immediately on the imner side of the stylo-mastoid
foramen.

This chain of ossicles, with its fellow of the opposite side, together
constitute the anterior cornua. (See also Fig. 46.)

At the hinder margin of each end of the basi-hyal (just below the
attachment of the cerato-hyal) is a cylindrical bone attached, called
the thyro-hyal (th). This is about as long as the basi-hyal, and
shorter than the stylo-hyal. It is connected by membrane with the
upper border of the lateral part of the thyroid cartilage of the larynx.

§ 39. On examining in greater detail than heretofore, and with that
knowledge of its component bones which the foregoing pages may have

ee ey eS a

CHAP. III. ] SKELETON OF THE HEAD AND TRUNK. 79

afforded, we find, when the outside of the SKULL IS VIEWED IN FRONT,
(Fig. 30) the following parts :—Below, the maxille and pre-maxille
form the alveolar borders. The curved outline of the vertex (/) is
_ formed by the frontals. The two large and conspicuous orbits are
bounded below by the zygomata, from which the malar post-orbital
processes (7) ascend, and approach the descending (pf) post-orbital
processes of the frontals. Between the orbits there is a broadish
bony expanse (formed by the frontals, nasals, and maxille), except
inferiorly where the heart-shaped aperture of the anterior nares is
situated—only bounded below by the horizontal processes of the
pre-maxillee (pm). The nasal bones (m) ascend rather higher than
do the nasal processes of the maxille. On each side of the anterior
nasal opening, and just beneath the margin of the lower boundary
of the orbit, is the large opening of the infra-orbital canal (2).

The parts which project furthest outwards are the zygomatic
processes of the temporal bones (2).

At the back of each orbit is seen the convex side-wall of the
skull (/) projecting into it, but the foramina which open into the
bottom of the orbit are hidden from this point of view.

On examining the BASE OF THE SKULL (see Fig. 29), we find in
front the alveolar margin (describing an acute but truncated angle,
with its truncated apex forwards) surrounding the bony palate (m
and p), which extends a little further backwards than do the teeth.
The anterior end of the bony palate is formed by the pre-maxillee (pm),
between which and the maxille are the two large anterior palatine
foramina. -At above the place of junction of the palatine plates of
the maxille with the palatines, there are on each side one or two
much smaller foramina, termed the posterior palatine foramina (8).

Behind the palate, we have, in the middle, the meso-pterygoid
fossa (ps) (into which the posterior nares open), bounded laterally
by the palatines and pterygoids (pt). External to this, is on each
side the wide vacant space of the temporal fossa enclosed by the
zygoma.

Behind the meso-pterygoid fossa the basis cranii presents a
straight surface of about equal width, formed successively by the
under surfaces of the basi-sphenoid (6s) and bast-occipital (do), and
terminated posteriorly by the occipital condyles (oc) and foramen
magnum (fm). At the hinder and outer side of each pterygoid
bone is the minute pterygoid fossa, external to, and partly hidden by,
the hinder part of which is the foramen rotundum (8); while the
foramen ovale (9) is again just behind, and external to, the foramen
rotundum. External to the foramen ovale, and on a line with it, is
the glenoid fossa for the lower jaw (g), bounded posteriorly by the
post-glenoid process behind, and internal to which is the fissura
Glaseri. Behind this again, is the large and swollen auditory
bulla (6), at the anterior end of which, immediately behind the
foramen ovale, is the anterior aperture of the Eustachian tube (10),
and a very small aperture called the foramen lacerum anterius, lead-

- ing into the inside of the cranium. Between the inner hinder part

80

ee

of the auditory bulle and the basi-occipital is the large and con- a

spicuous foramen lacerwm posterius (11), which transmits the jugular
vein and the glosso-pharyngeal, par vagum and spinal accessory

S- 3
Ss

Fig. 46.—SIDE VIEW OF THE CRANIUM, THE LOWER JAW AND THE HYOIDEAN ARCH
BEING SOMEWHAT DETACHED.

a. (Just above 6 and 7). Ali-sphenoid. |

ae. Meatus auditorius externus.
an. Angle of mandible.

ar. Ascending ramus.

b. Auditory bulla.

bh. Basi-hyal.

c. (Of cranium) occipital condyle.

c. (Of mandible) coronoid process.

ch. Cerato-hyal.
eh. Epi-hyal.
f. Frontal.
hr. Horizontal ramus of mandible.
wp. Inter-parietal.
j. Malar (or jugal).
la. Lachrymal.
m. Maxilla (its nasal process).
ms. Mastoid process.
Nasal.
‘0s. Orbito-sphenoid.
p. Parietal.

pa, Palatine.

pt. Pterygoid..

pm. Pre-maxilla.

s. Squamosal.

sh. Stylo-hyal.

so. Supra-occipital. :

t*, Cartilage of tympano-hyal.

th. Pit of tympano-hyal.

. Apex of lambdoidal ridge.

Zygoma.

. Infra-orbital foramen.

. Optic.

. Sphenoidal fissure.

. Foramen rotundans.

. Foramen ovale.

12. Stylo-mastoid foramen.

13. Mental foramina.

The spheno-palatine foramen is shown just)
above, and in front of pa, close to posterior
margin of anterior end of zygoma.

COMMONS

nerves. This foramen is bounded behind by the exoccipital (pp),
which is perforated by the anterior condyloid foramen transmitting
At the anterior wall of the foramen lacerum
posterius is the opening of a very small canal (for the minute
internal carotid artery) which runs forwards (between the basi-
occipital and basi-sphenoid on one side, and its auditory bulla
on the other) to open inside the cranium beside the sella turcica.

the hypoglossal nerve.

eo oy eee

CHAP. III. ] SKELETON OF THE HEAD AND TRUNK. ~ 81

Behind the post-glenoid process, the large meatus auditorius externus

. 1s to be seen, and close behind it the stylo-mastoid foramen (12),
immediately internal to which is the. pit for the tympano-hyal,
in close contiguity to which again the small mastoid process is seen
descending (ms).

Looking at the sIDE OF THE SKULL, we see above, the evenly-
arched outline of the cranium and face (formed by the nasals,
frontals, and parietals), with the straight but inclined line of the
occiput behind. The base of the skull is almost straight, though

Fig 47.—SKULL VIEWED, FROM BEHIND WITH THE LOWER JAW DETACHED.

4a Angle of mandible. 0~™“\_~ oc. Occipital condyle.

o. Auditory bulla. p. Parietal.

bo. Basi-occipital. pf. Post-orbital process of frontal.

c. Coronoid process of mandible. pj. Post-orbital process of malar.

J. Condyle of mandible. so, Supra-occipital,

jm. Foramen magnum. sq. Squamosal.

g. Glenoid surface. z. Zygoma.

gp. Post-glenoid process. 14, Inferior dental foramen.

vp. Inter-parietal. The par-occipital process is seen (on each side)
i. Lambdoidal ridge. between the occipital condyle (oc), and the
ms. Mastoid process. auditory bulla (6), and above the latter.

the middle part does not descend so much as does the alveolar
margin in front or the auditory bulla behind. The anterior end of -
the skull is formed by the small premaxilla (Fig. 46, ym), which
ascends and joins the nasal (n). Behind this the wide nasal process of
the maxilla (m) is interposed in front of the orbit, the anterior margin
of which slopes upwards and backwards. Just inside the lower part
of that margin is the lachrymal bone (/a) with its foramen ; behind
which is the os planum. The frontal (/), palatine, pre-sphenoid, and
orbito-sphenoid (os), form the inner wall of the orbit. Just below
the front part of the inferior margin of the orbit is the infra-orbital
foramen (2). Behind, and on a level with this (within the orbit),
G

Er OM OP ear hea weno ae GAP ee Toe ee ee en ey
Aye | Orem RTE cS arene i)

a THE CAT. (CHAP. 1

are the spheno-palatine foramen and the posterior palatine canal.
The orbit is seen to be bounded below by the maxilla, on which the
malar (7) 1s imposed, and sends up its post-orbital process towards,
but not to, the descending post-orbital process of the frontal. The
lower margin of the malar is strongly concave, and the zygomatic
process of the squamosal (z) is also strongly concave below, the
zygoma being much arched upwards as well as outwards.

At the bottom of the orbit we find, one behind the other, the
optic foramen (6), sphenoidal fissure (7), round foramen (8), and
the foramen ovale (9) ; while the side wall of the cranium sends
outwards a marked but blunt projection (formed principally by the
ali-sphenoid), which runs upwards towards the post-orbital process of
the frontal, and would, if it were greatly enlarged, more or less
enclose the orbit posteriorly.

Beneath the hinder end of the zygoma, is the glenoid fossa
and post-glenoid process; and behind this, the auditory bulla (6),
with its external meatus (ae), the stylo-mastoid foramen (12), the
pit for the tympano-hyal (¢), and the mastoid (ms) and par-occipital
processes. Thence, the lambdoidal ridge (y) runs upwards and
backwards, while behind and beneath it we have the ex- and
supra-occipitals (so), with the occipital condyle (c).

If the skull be viewed from behind, we see extending beyond its
globular mass (the upper walls of which are formed by the parietals
(Fig. 47, p)) the zygoma, widely arching out on each side (sz),
the much smaller post-orbital processes of the frontal (pf) above,
and the depending, rounded, auditory bulle (6) below. In the
middle, between the bulle, there is the foramen magnum (/m),
with the occipital condyle (oc) on each side of it. The bulla is seen
to be clamped laterally and behind by the mastoid (ms) and par-
occipital processes, which are closely applied to it. The foramen
magnum is bounded above by the supra-occipital (so), on each side
of which the lambdoidal ridge (2) runs up to the interparietal (7p).

In the lower jaw we see the angle (a), the great transverse extent
of the articular condyle (f), and the lofty coronoid process (ce).

If the skull be examined dorsally, the two large frontals and
parietals will be seen separated by the crucial mark formed
by the sagittal, frontal, and coronal sutures, while the maxille,
. premaxillz, and nasals, are conspicuous in front (Fig. 28). The
floor of the orbit is also well seen to be composed mainly of the
maxilla (m), with the help of palatine (p) and lachrymal (/*)
internally, and of the malar (7) externally. The posterior opening
of the infra-orbital canal also comes into view as well as the
posterior palatine foramen (4) and the spheno-palatine foramen (5).
The inward curvatures of the post-orbital processes of the malars (py),
and the outward curvatures of the frontal post-orbital processes (pf)
are also very marked from this point of view. 7

In the INSIDE OF THE CRANIUM, as seen from above when a
horizontal section is made and the top of the skull is removed, we
may note the following conditions :—

My ee <a’ glee’? a ae Cee Oe) BAe ais BO i ie all oot 0) tet well eae Me —_ ball a i Nal i ell ae

CHAP. III.] SKELETON OF THE HEAD AND TRUNK. 83

In the middle, in front, is a small fossa bounded anteriorly by the
cribriform plate, and on each side by the orbital plates of the frontal.
This is the o/factory, or rhinencephalic, fossa, which sheiters the
olfactory lobes of the brain. The hinder part of its floor is formed
by the pre-sphenoid.

Behind the olfactory fossa is the great middle fossa of the cranium,

bounded posteriorly by the ossified tentorium, which is attached to
the parietals and petrosals. In the middle of the floor of this great
chamber is the pituitary fossa, or sella turcica (Fig. 49), situated on
the upper surface of the basi-sphenoid. On each side of this (placed
successively in series running backwards and outwards) are (1) the
optic foramen (piercing the orbito-sphenoid); (2) the sphenoidal
fissure (placed beside the anterior wall of the pituitary fossa) ;
(3) the foramen rotundum; and lastly (4) the oval foramen; the
latter being on a line with the hinder part of the pituitary fossa.
_ External to this line of foramina on each side, there is a depression
(on the upper surface of the ali-sphenoid and squamcsal) which is
called the internal temporal fossa, because it shelters the temporal
lobe of the brain.

Behind the pituitary fossa is the clinoid plate, and behind and
external to this on each side is an opening between the petrosal,
the ali-sphenoid, and the anterior end of the tentorium, which
opening communicates with the cavity of the auditory bulla and with
the foramen lacerum anterius.

Behind the clinoid plate and the tentorium, is the posterior fossa of
the cranium—called also the cerebellar fossa, because it shelters that
part of the brain called the cerebellum. The floor of this fossa is formed
by the basi-occipital, and its sides by the ex-occipitals and petrosals.

Between the basi-occipital and the adjacent petrosal there runs
forwards on each side a very minute canal destined for the carotid
artery. The surface of the petrosal exhibits the conspicuous
opening to the internal ear—the meatus auditorius internus—with
the fossa above it for a process of the cerebellum (Fig. 35, B, cb),
above and behind which again is the prominence indicating the
anterior vertical semi-circular canal.

Behind each foramen lacerum posterius, and separated from it
by a narrow bridge of bone, is the anterior condyloid foramen. The
inner surface of the sides and roof of the cranium is marked by wide
and shallow depressions corresponding with eminences on the surface
of the brain, and also with narrow meandering grooves indicating the
course of the blood-vessels.

The skull VERTICALLY BISECTED, in the direction of the sagittal
suture, exposes the larger ‘size of the brain cavity than of the part
which forms the face ; also the inclined condition of the cribriform
plate (Fig. 48, cp) and the more nearly vertical position of the foramen
magnum at quite the hinder end of the skull.

The basilar parts of the occipital and sphenoid bones (Fig. 49, bo, bs,
and ps,) are seen to become thicker as we go forwards; they form the
true axis of the skull, and a line drawn from the anterior margin of

ens da Oe te Ty eR Ok ht) A en no a iy

84 THE CAT. (omar: a

the foramen magnum to the front end of the middle part of the

Fig. 48.—OvTLINE OF VERTICAL SECTION oF SKULL, TO SHOW BY STRAIGHT BLACK LINES THE
INCLINATION OF THE BASI-FACIAL AXIS TO THE BASI-CRANIAL AXIS, AND THE ANGLES
FORMED WITH THE LATTER BY THE PLANES OF THE CRIBRIFORM PLATE AND OCCIPITAL
FoORAMEN ; ALSO THE RELATIVE CEREBRAL LENGTH.

be. Basi-cranial axis. axis to the summit of the attachment of the
of. Basi-facial axis. tentorium.
c. Length from the front end of the basi-cranial cp. Plane of cribriform plate.

jm. Plane of foramen magnum,

upper (or cerebral) surface of the pre-sphenoid is called the basi-
cranial axis (Fig. 48, bc). A line drawn from the same point of the

Fig. 49.—VeRTICAL ANTERO-POSTERIOR SECTION OF SKULL, MADE A LITTLE NEARER THE
SPECTATOR THAN THE EXACT MIDDLE LINE TO SHOW THE MEDIAN ETHMOID, ETC.

af. Aqueduct of Fallopius. n. Nasal.

ai. Internal auditory meatus, ps. Pre-sphenoid.

b. Auditory bulla. pt. Pterygoid.

bo. Basi-occipital. s. Squamosal. _

c. Occipital condyle. sq. Basi-sphenoid.

et. Lateral ethmoid. so. Supra-occipital.

f. Frontal. ¢. Inner surface of frontal.

fm. Forainen magnum. v. Vomer. 4

ip. Inter-parietal. ' The anterior condyloid foramen above ¢
me. Mesethmoid. and bo, just over the letter 0.

mt. Ethmo-turbinal,

pre-sphenoid to the front part of the alveolar margin of the pre-

CHAP, III. ] SKELETON OF THE HEAD AND TRUNE. 85

maxilla is the basi-facial axis (bf), and the two axes in the cat form
an angle of 145°.

The basi-cranial axis forms with the foramen magnum (/m) an
angle of 110°, while with the cribriform plate (cp) it forms one of
155°—open upwards and backwards.

The extreme length of the line (0), slightly exceeds that of the
basi-cranial axis (bc), while it is itself somewhat exceeded by the

cerebral length, i.e., the length between the front end of the olfactory.

fossa and the hind-most point of attachment of the tentorium.

As to the details of the parts shown in a median vertical section,
we see in the first place the large cerebral chamber (Fig. 49, s, ¢), in
front of which is the more solid, facial part with the mesethmoid (me)
interposed between the vomer (v) below and the inflected plates of
the frontal and the nasal (f, 7).

The cerebral chamber is seen to be Beied behind by the bony
tentorium descending as a free process from the hinder end of the
parietal (py), and being attached to the inner anterior margin of the
petrosal. In the petrosal we see the internal auditory opening (a)
in a fossa, from the anterior part of which (af) proceeds the aqueduct
of Fallopius. Above and slightly behind this fossa, is seen that for
the cerebellar process. We see also the concavity of the pituitary
fossa in the upper surface of the basi-sphenoid (sg), with the large
air-cavity in the pre-sphenoid (ps). In the ex-occipital we see the
anterior condyloid foramen (for transmitting the hypoglossal nerve),
with another foramen, for a vein, behind it.

When the skull is cut vertically a little on one side of the antero-
posterior median line we then see (Fig. 50) the frontal sinus (/s)
extending backwards over the anterior part of the cranial cavity.
We also see how the ethmo-turbinal, or lateral ethmoid, sends its
lamellee quite upwards in front of the frontal sinus (the upper et),
as well as horizontally forwards (the lower e¢ of Fig. 50). We also
see more plainly (than in the perfectly median vertical section)
the contrast which exists between the direction followed by the folds
and furrows of the ethmo-turbinal and that which the folds and
furrows of the maxillo-turbinal (m7) follow.

When the skull is divided vertically through the external auditory
meati (1.e., transversely, or in the direction of the coronal suture) we
see that the basilar part of the occipital forms as it were a centre. -

The anterior part of such a section shows the great cranial arch
rising above this centre and closed in front, while below it, is the
arch of the lower jaw and further forward the arch of the upper
jaw—enclosing the double tube of the nostrils, which extends from
the anterior to the posterior nares.

The posterior part of the section shows us the hinder part of the
great cranial arch rising above around the foramen magnum
behind, while below it, is the arch of the hyoid extending downwards
on each side from the tympano-hyals to the basi-hyal.

As to the CAVITIES OF THE SKULL: the two orbits are separated
one from another in part by the cranial cavity (behind the cribri-

86 «THE CAT. ‘ A

form plate), and in part by the nasal cavity (in front of the
cribriform plate). -

The nasal fosse extend backwards, above the palate, from the
anterior to the posterior nares, and are enclosed between the pre-
maxilla, maxillz, and palatines, being separated from each other
by the median ethmoid and vomer, and, in front of these, by a
median cartilage of the nose called ‘ septal.” The lateral ethmoid
projects forwards into each fossa from the cribriform plate (cp).

The roof of the nasal cavity slopes downwards both anteriorly

Fig. 50.—LonGITUDiNAL VERTICAL SECTION OF FACE MADE A LITTLE FURTHER OFF
THAN THE MIDDLE LINE.

cp. Cribriform plate. p. Palatine.

et. Lateral ethmoid or ethmo-turbinal. gm. Pre-maxilla.
Js. Frontal sinus. ps. Pre-sphenoid.
amt. Maxillo-turbinal. pt. Pterygoid.

m. Maxilla.

and posteriorly. Its floor is formed by the palatal plates of the
maxille and palatines, and is pierced, towards its anterior end, by
the anterior palatine foramina. |

The spheno-palatine foramen opens into the nasal cavity on each
side towards the hinder end very near its floor.

The bones of the cranial vault are densest at the surface, beneath
which is a coarser, spongy bone-tissue termed “ diploe.” Here and
there are much larger cavities, which are filled with air, and are
termed sinuses. Of such there are two sets.

The first of these, the frontal sinuses, are in the substance of the
frontals (fs), and they communicate with the nasal fosse. The
other set, the sphenoidal sinuses, are situated in the pre-sphenoid,
and are smaller than the frontal sinuses (Fig. 49, ps). |

§ 40. Besides the ricamenrs of the skull already noticed—those
connecting it with the vertebral column—other ligaments connect
the mandible with the cranium.

These may be described as the “ capsular” and “ stylo-maxillary ”
ligaments. ‘

The apposed surfaces of the mandibular condyle and glenoid
cavity are, in the fresh condition, each coated with cartilage, and

CHAP. III.] SKELETON OF THE HEAD AND TRUNK, 87

_ two fibro-cartilaginous disks (inter-articular fibro-cartilages) are inter-
posed between the two articular surfaces. Motion is facilitated by
three separate synovial membranes; one between the disks, one
between the upper disk and the glenoid surface, and the third between
the lower disk and the condyloid surface.

The capsular ligament is a fibrous membrane which surrounds
the articulation just mentioned, its fibres passing from the circum-
ference of the glenoid surface to the condyle. It adheres to the
margins of the interposed fibro-cartilaginous disks, and it is
strengthened on its inner and outer sides by certain accessory fibres
which might be distinguished respectively as internal and external
lateral hgaments.

The stylo-mavillary ligament arises mainly from behind, but
partly from in front of the margin of the meatus auditorius externus.
It passes to the angle of the mandible.

It gives attachment, on its inner side, to some of the fibres of the
internal pterygoid muscle. The stylo-glossus is attached to its
upper surface, while its exterior is connected with the masseter.

A thin interarticular cartilage is interposed between the anterior
margins of the two horizontal rami of the mandible.

Another cranial hgament which it may be well to mention, is
the post-orbital ligament which connects the apex of the post-orbital
process of the malar with the apex of the adjacent post-orbital
process of the frontal.

§ 41. Having now completed our survey of the parts which make
up the cranial division of the cat’s axial endo-skeleton, the most
generalized view of them at present attainable may, perhaps, be
expressed as follows :—

The skull consists of a central axis, made up of the bast-occipital,
basi-sphenoid, and pre-sphenoid, and which axis is continued on
forwards by the median ethmoid.

To this central axis ascending and descending arches are annexed,
having certain other structures intercalated between the former.
Thus we have an occipital arch completed by the basi-occipital,
ex-occipitals, and supra-occipital.

Secondly, we have a posterior sphenoidal arch, completed by the
ali-sphenoids and parietals.

Thirdly, we have an anterior sphenoidal arch, completed by the
orbito-sphenoids and the frontals. These three arches embrace the
brain, which is the enlarged anterior contimuation of the spinal
marrow and forms the anterior termination of the nervous centres.
On this account these arches may be termed “neural,” like the
vertebral arches which similarly enclose the spinal marrow.

The most anterior, or anterior sphenoidal arch, is open in front,
the bone of the olfactory organ (the ethmoid) being, as it were,
thrust into the aperture which is left by it.

Into the gap left on each side between the ex-occipital and the
ali-sphenoid, the auditory organ (the temporal bone) is thrust.

Similarly, the very much smaller gap left between the ali- and

gg | «HE OAT.

orbito-sphenoids (which is indeed only represented by a large foramen, —
and the sphenoidal fissure) is filled up by the organ of sight, which, __
though not ossified in the cat (as the olfactory and auditory organs
are), is protected by bony processes about it. (sig |

Beneath the basis cranti we have :—(1) the thyro-hyals, which
send up no connecting ligaments to the skull, but which through
the basi-hyal are connected, by the epi- and cerato-stylo-hyals with
the tympano-hyals. (2). In front of this hyoidean arch we have
the mandibular arch, and (3) again in front of this we have an
arch formed by the pterygoid and palatines, and bordered externally
by the maxille and pre-maxille. This last arch is amalgamated
with the bony covering of the nostrils (the nasals) and with the
outer protection of the orbits (the malars), which latter send back, |
on each side, a bony arch (the zygoma) to the ossified envelope of
the auditory organ.

Thus we seem to find in the cranial part of the axial skeleton, a
sort of reminiscence of the structure of the parts composing its spinal

ortion.

i From median axial structures which seem to repeat the vertebral
centra, neural arches arise and ventral girdles descend, which arches
and girdles seem to repeat, on a different scale, the neural and rib
arches of the trunk. .

CHAPTER IV.

THE SKELETON OF THE LIMBS.

1. Tue skeleton of the limbs, or appendicular skeleton, is divisible
into the skeleton of the anterior, thoracic or pectoral limbs, and that
of the posterior abdominal or pelvic limbs.

THE SKELETON OF THE PECTORAL LIMB.

The bones of the cat’s PECTORAL LIMB belong to three categories :
A. those of the shoulder; B. those of the fore-leg ; and C. those of
the paw. |

A. Those of the shoulder are the blade-bone, called the scapula,
and the collar-bone, called the clavicle. These, with their
fellows of the opposite side, constitute what is called the
shoulder-girdle.

B. Those of the fore-leg are subdivisible into (a) the bone of the
part above the elbow, called the humerus, and (b) the bones of the
part below the elbow, called respectively the radius and the ulna.

C. Those of the paw are divisible into three sets: (a) the bones
of the wrist, called in anatomy the carpus; (6) those of the
middle solid part of the paw, called the metacarpus; and
(c) those of the toes (or digits), which are called phalanges.

§ 2. The scaPuta is a flat, somewhat triangular bone, with three
borders and two surfaces. One border is anterior, one is superior,
and one is posterior. The superior border (Fig. 51, 7) is also called
‘< vertebral,” because it is the one nearest to the vertebral column.
The posterior border (x) is also called “axillary,” because it is
adjacent to the axilla, or arm-pit. Of its surfaces, one is applied
against the ribs, and is concave; it is called the subscapular fossa,
and affords attachment to the subscapularis muscle. It presents one
or two oblique ridges.

The other (dorsal or outer) surface is divided obliquely into two
unequal parts by a prominent ridge, called the spine (s), on which
account the smaller part in front of the ridge is termed the supra-
spinous fossa (ss), and the part behind it (7s) the infra-spinous fossa.
These spaces are occupied by correspondingly named muscles.

The spine of the scapula becomes gradually more prominent from
_ the vertebral border of the bone, while at its outer end the spine

90 COOL Me area 7 CaM caaueEs [oua

projects freely as a small process terminating in a rounded end, an
called the acromion (a); but before so terminating, it gives off a

backwardly directed lamellar freely pxojecting process termed the __

metacromion (m).

The anterior border of the scapula (which is rounded and convex)
exhibits at its lower end a rounded notch (”). Below this notch
there rises a short strongly projecting, much curved, pointed pro-
minence, called the coracoid process (Fig. 82, ¢).

The superior border of the scapula (v) is the shortest. It is very
slightly convex. |

The axillary border is the longest, and is more or less grooved on
its inner aspect (x). It descends obliquely from the lower end of

Fig. 51.—RicuHtT SCAPULA, SEEN EXTERNALLY.

a. Acromion.
g. Glenoid surface.
is. Infra-spinous fossa.

ss. Supra-spinous fossa.
v. Vertebral border,
xv. Axillary border.

m. Metacromion. The coracoid process is shown at the right-hand
mn. Supra-scapular notch. extremity of the figure above, and to the
s. Spine. left of the letter a.

the vertebral border to a rounded concave, shallow, articular
surface (g), called the glenoid cavity (into which the head of the
upper-arm bone is received), and which is overhung in front by the
coracoid process (c), while the acromion projects externally to it.
The part which supports the glenoid surface is called the neck.

The anterior and vertebral borders meet in a rounded prominence,
while at the junction of the axillary and vertebral borders is a small
flattened space for the insertion of a muscle called the teres major.

The coracoid and acromion arise from distinct centres of ossifica-
tion. The coracoid ossification contributes to form the glenoid cavity.

The cLAVICLE is a very small slender styliform bone, pointed at
each end, and suspended in the flesh between the acromion process
of the scapula and the manubrium of the sternum, but not touching
either of those parts itself.

§ 3. The numeERus is the largest, but not the longest, bone of the

»

; ; 4m ok
ee ee EAR re iF

CHAP. Iv. ] THE SKELETON OF THE LIMBS. 91

pectoral limb, and extends from the shoulder to the elbow-joint. It
is imperfectly cylindrical, being flattened from side to side above,
and from before backwards below. It describes a very slight
sigmoid curve from above downwards, convex forwards above and
concave below.

The cylindrical part (or shaft) has its inner surface marked above
by a wide longitudinal depression, termed the bicipital groove,

A

Fig. 52.—Ricut ScaPua.

A. Seen from below. sb. Sub-scapular fossa (with two oblique ridges)
B. Seen from within. az. Axillary border, showing its longitudinal
c. Coracoid process. groove.

g. Glenoid surface. The acromion process is seen in figure A, just

m. Metacromion process. above the letter m.

because it lodges the tendon of a muscle called the Biceps. External
to this is a slightly roughened and elevated tract (dr) called the
deltoid ridge, as 1t serves for the insertion of the deltoid muscle.

The lower part of the shaft has its anterior surface separated
from the posterior surface by two lines (or ridges), one on each side,
which become especially well marked as they approach the lower
end of the bone. The outer (7s) of these two ridges (which is the
stronger and more posteriorly situated of the two) is termed the
supinator, or external condyloid ridge, while the inner one is named
the internal condyloid, or pronator ridge. Just within it is an
elongated opening, or foramen, called the supracondylar foramen (fe),
which transmits the median nerve and brachial artery.

On the hinder surface of the shaft (avhich is generally convex)
there may be detected a very slightly marked oblique groove (called
the musculo-spiral), passing from above downwards and outwards.

The upper end of the humerus shows a large rounded convex
head (h), covered, when fresh, with cartilage, and articulated to the
glenoid surface of the scapula. This head is not placed on the
middle of the summit of the bone, but on its hinder and inner
aspect, so that its axis does not comeide with that of the shaft. .

On the outer and inner sides of the head of the humerus, are two

—

92 Lae He Cea OO

blunt prominences. One of these (Fig. 54, ¢!) and (Fig. 53, 7)
termed the greater (radial* or preaxial) tuberosity, is on the outer

side of the summit of the bicipital groove. It reaches considerably _
above the summit of the head of the humerus. At its hinder endis

-

Fig. 53.—Tue Ricat HuMeERwvs.

A. Front. dr. Deltoid ridge.
B. Back. jc. Supra-condyloid foramen.
C. Summit. h. Head.
D. Lower end, with its hinder margin at o. Olecranal fossa.

the upper border of the figures. . Surface for infra-spinatus,
a. Trochlea. rs. Supinator ridge.
bg. Bicipital groove. t. Inner margin of trochlea.
ce. Capitellum. 1f. Great tuberosity.
ce. External condyle. 2f. Lesser tuberosity.

ct. Internal condyle.

a conspicuous depressed surface (p), for the insertion of the infra-
spinatus rouscle. ‘The other smaller prominence is called the desser
(ulnar, or post-awial), tuberosity (Fig. 54, ¢?) and (Fig. 53, 2f), and

* “Radial” because on the side of the | is vertical, it is in front of the long axis
radius, “pre-axial’’ because when the arm ! of the arm.

, oe

CHAP. IV. | THE SKELETON OF THE LIMBS. 93

is placed on the inner side of the bicipital groove. Both tuberosities
serve for muscular attachments.

The lower end of the humerus expands considerably, having a
lateral prominence termed a condyle, on
each side, but the internal condyle (c7) pro-
jects further inwards than does the external
condyle (ce) outwards.

Between these projections is placed the
lower articular surface for the bones of the
forearm.

This is irregularly concave and convex.
At its outer part is a rounded prominence
(convex transversely as well as from before
backwards) called the capitellum (c), which
joms the outer bone of the fore-arm or
radius. Internal to thisis a pulley-like trans-
versely concave surface (a), the trochlea,
which joins the inner bone of the fore-arm
orulna. The groove of this “ pulley” ex-
tends completely round from the anterior fo
the posterior surface of the humerus. The
capitellum and the trochlea run one into the
other without any distinct demarcation.
There is a shallow cavity in front of the
humerus immediately above the trochlea.
This is called the coronoid fossa, because it
receives the coronoid process of the ulna.
There is another much deeper fossa (0), also
above the trochlea, but on the hinder surface
of the humerus. This is called the olecranal
or anconeal fossa, from the part of the ulna
which it receives when the fore-leg is
straightened. The inner margin of the
distal articular surface of the humerus (¢),
descends much below its external margin.

§ 4. The Rapivs (which is_ slightly nas eee ene tra
shorter than the humerus) is also a long — « Capitelum. __
cylindrical bone, expanded more or less at % tntonsledyle
each end, and flattened on that side which = ¢",peltold ridge.
is behind when the fore-leg is so placed — ¢, Inner margin of trochlea.
that the paw rests on the ground. At its ae ean.
place of attachment above, it is the external
bone of the fore-arm. The long middle part of the bone, or shaft,
is a little curved, with the convexity forwards and outwards. At
‘the upper part of its inner margin is a prominence called the
tuberosity (t), into which is inserted the tendon of the biceps
muscle. Just above this bicipital tuberosity the bone is nar-
rowed into what is called the eck, from which rises the head (h)
of the bone. This head is oval in shape, with a smooth margin.

94 THE OAT. [CHAP Iv.

and concave above for articulation with the capitellum of the

humerus. i
At its lower end the radius becomes much broadened out, and its

anterior or extensor * surface is grooved for the passage of tendons.

uu
(12
C
Fig. 55.—TuHeE Ricut Ravivs. ;
A. Anterior and outer aspect. h. Head.
B. Posterior and inner aspect. s. Styloid process.
C. Distal articular surface for wrist. t. Tuberosity. 4
D. Proximal surface for humerus. uw. Surface for ulna.

mil Pte yao

Its outer side is prolonged into what is called the stywid
process (s). The lower end of the bone articulates with the wrist
by a large concave surface supporting the fore-paw, which is carried

* Called ‘‘extensor” because the muscles which stretch the toes are attached
to this surface.

CHAP. IV. ] THE SKELETON OF THE LIMBS. 95

round by and with the radius in that motion of the arm and band
which is called pronation and supination—movements which will be
explained when the articulations and ligaments of the pectoral limb

wv

Fig. 56.—THE RicHTtT ULNa.

“

A. External aspect. Is. Lesser sigmoid cavity.
B. Internal aspect. e. Olecranon.

C. Surface of sigmoid fossa. 7. Surface for radius.

c. Coronoid process. s. Styloid process.

gs. Greater sigmoid cavity.

are described. The outer lower end of the radius also presents, in-
ternally, a small articular surface for the ulna (w).

§ 5. The vuLNa, or post-axial bone of the forearm, is longer than
the humerus, and considerably longer than the radius. While the
latter bone is broader below than above, the reverse condition obtains

in the ulna. The shaft is flattened both in front and behind, with a

vo
Bis.

ge Ne ee ae ee ee Se ee

:

96 THE CAT. [cmap tv,

rather sharp inner or radial margin, to which a membrane (the
interosseous membrane) is attached, which connects the shaft of the
ulna with that of the radius.

The upper end of the ulna presents a deep concavity (gs) for
articulation with the trochlea of the humerus. This fossa is called
from its shape, the great sigmoid cavity, and is divided unequally
by an ill-defined vertical prominence which extends between the two
processes which bound the fossa above and below respectively.

The lower of these two processes is called the coronoid process (ce),
and is received into the corresponding fossa on the front of the
humerus. The inferior surface of its apex 1s rough, and serves for
the insertion of the brachialis anticus muscle. )

The higher and much larger process is termed the olecranon (0),
and passes into the olecranal cavity on the back of the humerus
when the limb is stretched out. The olecranon forms the prominence
of the elbow, and terminates in a rough process or “ tuberosity,”
into which the triceps muscle is inserted.

On the outer side of the coronoid process is a small, elongated
concave, articular surface called the lesser sigmoid cavity (ds), destined.
for the border of the head of the radius which turns upon it.

The lower end of the ulna presents a small, rounded, convex
surface or head, which articulates with the adjacent surface of the
radius. On the opposite side there is developed a large, laterally
compressed prominence called the styloid process (s), which directly
articulates with the wrist. |

§ 6. The carpus consists of seven small bones arranged in two
transverse series. .

The bones of the upper or proximal row are: (1) The scapho-
lunar bone ; (2) the cuneiforme ; (3) and the pisiforme.

The first two together form an upper convex surface which fits —
into the distal articular cup of the fore-arm. The carpus has a
convex dorsal surface, while its palmar surface 1s concave from side
to side.

The scapho-lunar bone (Fig. 57, s?) is the largest of all. Its long
axis is transverse. Above, it is smooth and mainly convex, and joins
the radius. Below, it fits into a depression formed by the four distal
carpals. From the hinder part of the outer side of the bone a
tubercle projects outwards and backwards. ‘To this tubercle there
may be attached a small bone which is found within the tendon of
a muscle here inserted. Such a bone 1s called a “‘ sesamoid bone.”

The cuneiforme (c) is somewhat wedge-shaped, and articulates
below with the innermost, or most ulnar, carpal only.

The pisiforme (p) is a bone which projects freely backwards and
downwards from the palmar surface, having a long, compressed and
curved process, which ossifies separately as an epiphysis (see Fig. 60,
pe). Itis mainly supported by the cuneiform, but also articulates
with the unciform.

The bones of the distal row are: (1) the trapezium; (2) the
trapezoides ; (3) the os magnum; and (4) the unciforme.

CHAP. Iv.] THE SKELETON

OF THE LIMBS. 97

~The trapezium (tm) is the smallest carpal and the most radial of the
distal series. It supports the pollex or most radial digit, for which

it presents a saddle-shaped articular surface, namely, one both

BONES OF RIGHT FORE-PAW.

Fig. 57.—PAaLMAR SURFACE.

s (Above) scapho-lunar bone.
s (Below) sesamoid.
tm. Trapezium.

u. Unciform bone.

c. Cuneiform bone.
m. Magnum.

mc. Metacarpals.

. Pisiform.

p'. Proximal phalanx.
p?. Middle phalanx,
p?. Distal phalanx.

iy Bollexc

II. Index

IiI Medius.

IV. Annulus.

V. Mininus.

concave and convex. It is convex from without inwards and

Fig. 58.—Dorsat SURFACE.

sl. Scapho-lunare.
td. Trapezoides.
tm. Trapezium.

wu. Unciform bone.
c. Cuneiform bone.
m. Magnum.

mc. Metacarpals.

. Pisiform.

p\. Proximal phalanx.
p?. Middle phalanx.
p. Distal phalanx.
Tt *Poliex?

Il. Index.

IIT. Medius.

IV. Annulus.

V. Minimus.

convex from before backwards.

The trapezoides (td) is also a small carpal. It articulates distally
by a slight convexity, with'the second metacarpal bone only. It is
very little visible on the palmar surface.

The os magnum (m) is considerably larger than the two preceding
earpals. It is convex above at its so-called ‘head.’ It articulates
below with three metacarpals, but mainly with the third, into the
proximal concavity of which it projects.

The wnciform bone (uw) is that carpal which lieson the ulnar side of
H

a HE Cat.

the distal row. It articulates slightly with the fourth, but mainly
with the fifth metatarsal. Its upper surface is narrow and convex.
Its: palmar surface developes a small process which is called the
“‘ palmar process.’

Fig. 59.—Bonrs or Meptvus Dierr. Fig. 60.—VERTICAL SECTION THROUGH BONES
m. Magnum. ‘OF ARM, Wrist, PoLLeXx, AND INDEX, TO SHOW
me. Metacarpal. EPIPHYSES.

s. Sesamoid. mie. The epiphysis of themetacarpal of the pollex
p'. Proximal phalanx. me. That of the index.
p”. Median phalanx. : ple. That of proximal phalanx of pollex and index
?. Distal phalanx. pe. That of second phalanx ou index.
a. Its apex embraced by claw. pe. That of pisiform.
6. Sheath of bone enclosing root of claw | ew. That of radius.

externally. er. That of ulna.

I, I, ll, IV, and V. The digits.

§ 7. The meracarpus consists of four elongated, and one short,
matacarpal bones, each supporting a digit (toe) at its distal end.
Each metacarpal has its proximal end, or base, specially moulded —
so as to fit that part of the surface of the carpus which it adjoins.
The distal end of each is in the form of a rounded head. wig
The metacarpals are curved so as to be slightly concave, from
above downwards, on their palmar aspect. The dorsal surface of
each is slightly more flattened than is the opposite side. .
The first metacarpal (that of the pollex) is less than half the
length of the shortest of the others, and differs from them by its
mode of ossification, its epiphysis being situate only at its proximal

CHAP. Iv.] THE SKELETON OF THE LIMBS. 99

end, while in each of the other metacarpals there is an epiphysis at.
the distal end only (Fig. 60).

The proximel surface of the first metacarpal is deeply concave
from side to side, and convex from before backwards, to suit the
saddle-shaped surface of the trapezium which supports it.

- The four other metacarpals decrease in length outwards from the
third, and the second is shghtly shorter than the fourth, but ‘longer
than the fifth. .

The articular surfaces of the heads of the metacarpals extend
further on the palmar than on the dorsal aspect.

Each on its palmar aspect has a median ridge, on each side of
which a small rounded ossicle, called a sesamoid bone (s), is attached.

The ulnar side of the proximal end of the fifth metacaxgpal
exhibits a slight prominence or tuberosity.

The distal surface of the first metacarpal slopes obliquely down-

wards and towards the ulnar side.
-. § 8. The toes, or Dieits, of the fore-paw (corresponding to our
thumb and four fingers) have each a distinguishing name.

Thus the first digit (thumb) is termed the pedlez.

The second is the index.

The third is the medius, or middle digit.

The fourth is the annulus, or ring digit.

The fifth is the minimus, or little digit.

Each digit consists of three rather elongated bones termed
PHALANGES, except the pollex, which has but two.

Each phalanx ossifies a an epiphy sis, which is situated at its
proximal end (Fig. 60, p! e and p’ e).

The two phalanges of the pollex are of nearly equal length.

_In every other digit the phalanges become successively shorter
and smaller, the third phalanx being, however, but little smaller
than the preceding one, while it is vertically expanded to support
the claw.

The phalanges of the proximal row (p!) are somewhat curved
like the metacarpals. They are smooth and transversely convex
dorsally ; on the palmar surface they are flat or somewhat concave,
each lateral margin being somewhat raised. At their proximal end
each is concave (for the supporting metacarpal), but distally each:

resents two condyles divided by a shallow groove. |

The middle row of phalanges (p*) are like the proximal ones,
except that they are smaller, and that each presents at its proximal
end a median elevation with a concavity on each side, these con-
cavities joining the convexities of the proximal metavarpals,

“The penultimate phalanx of each digit, except the pollex, is
hollowed out on its outer (or ulnar) side, and the ultimate phalanx
habitually les bent back, reposing in ‘the cavity thus prepared.
for it.

Each distal phalanx (Fig. 59) hasits proximal end produced back-
wards below, so that, when the bone is placed with its long axis
horizontal, ‘its articular surface looks upwards. Bey ond this

100 PHB CAR): voc qe aber

the phalanx is very much compressed laterally, ending distally in a Ks
sharp, vertically-curved process (a) like the upper beak of a bird of =

prey, and greatly flattened from side to side. A thin lamella of
bone projects forwards (2) above and on each side of the base of this
beak, enclosing a deep groove for the reception of the claw.

Two small round extra bones, called sesamoid bones (s), are (as

before said) placed beneath the junction of the proximal phalanx

and metacarpal of each of the digits.

nN
Ssssss

NS SN

SN

4
Ped
—S=S— : Z

y

Fig. 61.—ConNNEXIoNS oF Ricut HuUMERUS AND SCAPULA.
A. Seen within. ct. Clavicle.
B. Seen from above.
a. Acromion process. coraco-humeral ligament.
ah, Fibres from acromion to capsule. - 4s. Infra-spinatus, cut short.
6. Tendon of biceps. | ld. Latissimus dorsi, cut short.

c. Coracoid process. s. Sub-scapularis, cut short.
cc. Capsular ligament. sp. Supra-spinatus, cut short.
ca, Coraco-clavicular ligament. t. Transverse fibres.

§ 9. The pectoral limb, as a whole, is connected with the
dorsal part of the axial skeleton neither by cartilage nor hgament,
but by muscular connexion only. It is, however, connected with
the ventral part of that skeleton, namely, with the sternum and with
the first rib, by ligamentous union. Such a union exists between
the sternum and the rudimentary clavicle on the one part, and
between the clavicle and the scapula on the other part; for the
clavicle is connected with the coracoid process by a ligament called
coraco-clavicular (Fig. 61, cc).

The shoulder-joint is a remarkably free one, allowing the fore-leg
to be rotated to a considerable extent in all directions. The cartila-
ginous cup of the glenoid is deepened by a circular ligament (the
glenoid ligament) which surrounds its margin.

The joint is surrounded by a capsular ligament (ca), which
extends down from the glenoid ligament round the head of the

y
rot

dh and ch. Fibres from coracoid to capsule or

oh OF

CHAP. IV.] THE SKELETON OF THE LIMBS. 101

Miierds: to be inserted into the neck. It is lied by synovial

membrane.
- An accessory ligament, called the coraco-humeral (Fig. 61, dh),

passes from the coracoid process to the capsule and great tuberosity.

Fig. 62.—RicuT ELsow.

A. Seen in front. 4. Internal lateral ligament.
B. Inrer side. in. Inter-osseous ligameut.

. Median nerve.

Orhicular ligament.
Radius,

Triceps, cut short.

Ulna.

6. Tendon of biceps.

ba. Brachialis anticus.

ca. Posterior ligament.

ef. Condyloid foramen.

é. External lateral ligament.

anos

The lower end of the humerus so fits mto the greater sigmoid
cavity of the ulna as to permit the bending of the last-named bone
to and fro upon the humerus.

This joint is enclosed in a capsule furnished with a large synovial
membrane, and surrounded byfour hgaments. (1.) The cnterna/ lateral
ligament (Fig. 62, 7) radiates from the inner condyle to the coronoid
process and inner olecranal margin. (2.) The external lateral liga-
ment (e), which is much smaller, proceeds from the external condyle
to what will be shortly noticed as the annular ligament of the
radius. (3.) The anterior ligament descends from above the coronoid
fossa, while (4) the posterior ligament (ca) proceeds from the
margins of the olecranal fossa to the olecranon.

The upper end of the radius articulates with both the ulna an
humerus. Its head joins the lesser sigmoid, cavity of the ulna,
while from the front and hinder ends of that lesser sigmoid cavity
a strong fibrous band proceeds and unites opposite the cavity, thus
forming a ring, the orbicular ligament (Fig. 60, A, 0), which embraces
the head of the radius. This head rotates upon the capitellum

round the radius’s long axis) within the annular ligament.

‘The radius (with the paw which it carries with it) 1s thus able to

Pe etd ee ee SE REE Oa EL) Ona a ae mere] ORT Gy nae a rear

102 , THE CAT. [onaP. rv. :

perform the motions of pronation and supination without danger of
dislocation. | )

When the fore-leg and paw hang down, the sole of the fore-
foot—or palmar surface—being directed forwards, the position 1s
that of supination, and the bones of the fore-arm are situate side
by side.

av hen the fore-leg and paws are placed as in the act of walking,
the position is that of pronation, and the radius crosses over’ the
ulna. |

A ligament has already been mentioned which connects the —
shafts of the radius and ulna. This is the interosseous ligament or
membrane. It is a thin sheet of fibres which proceed obliquely
downwards and inwards from the ulnar margin of the radius to the ©
radial margin of the ulna.

The two rows of carpal bones are connected together by dorsal,
palmar, and lateral ligaments, so that they form an arch concave
towards the palm. Synovial membrane is interposed between the
proximal and the distal series of carpals.

The anterior annular ligament 1s a strong fibrous band from the ©
scapho-lunare and trapezium to the pisiforme, thus forming, with
the bones, a rig through which the tendons for bending the fingers
may pass down to the digits. :

The posterior annular ligament proceeds from the outer margin of
the lower part of the radius to the inner part of the cuneiform and
pisiform, forming a sheath through which the tendons for extending
the fingers pass down to the digits. ;

The proximal ends of the four ulnar metacarpals are joined to
the carpus by dorsal, palmar, and interosseous hgaments. The first
metacarpal is united to the trapezium by a capsular ligament.
Synovial membranes are interposed between the successive phalanges, _
and between the phalanges and the metacarpals. The distal ends
of the metacarpals are united to the proximal phalanges by lateral
and palmar ligaments. :

The last phalanx of each digit 1s bound to the last but one by a
very elastic ligament (Fig. 63), which passes from the dorsal surface
of the hinder part of the distal phalanx to the distal part of the
middle phalanx, and by its action keeps the former phalanx rolled
back upon the latter. It is put on the stretch, and the claw is
drawn downwards by a flexor tendon (to be described with the
muscles), which is held in place by a ligamentous loop attached to
the palmar surface of the proximal phalanx. is

An intermetacarpal ligament passes from the palmar aspect of the
distal end of the metacarpal of the pollex to the distal palmar
surface of the metacarpal of the index.

§ 10. A GENERAL view of the pectoral appendicular skeleton,
shows us that it forms an incomplete bony girdle, which is attached
to the axial skeleton on its dorsal aspect by soft parts only; but it
is connected with the ventral parts of the appendicular skeleton.
by the clavicles and by ligaments. The elbow-joint 1s so bent as to

; t
Cap. Iv. ] THE SKELETON OF THE LIMBS. 103

‘open forwards, and when the body is supported as in walking, the
.fore-legs are in pronation.
_ The skeleton of the fore-leg below the elbow is divisible into a
iri- and a bi-digital series, placed side by side.

Thus there is, first, the radius; the scapho-lunar bone; the

Fig. 63.—Dicit oF FoRE-PAW, WITH ITS LIGAMENTS.

Showing the elastic ligament which passes from claw) passing through the ligamentous loop
above the root of the claw, downwards and attached to the under surface of the middle
backwards to the distal part of the second phalanx. The sesamoid bone beneath the

phalanx ; also the long flexor tendon (which distal end of the metacarpal is also shown.
by being pulled backwards draws down the

trapezium, the trapezoides, and the magnum ; the first, second, and
third metacarpals; and the annexed digits forming the tri-digital
series.

We have, secondly, the ulna; the cuneiform; the unciform ; the
fourth and fifth metacarpals ; and the corresponding digits—forming
the bi-digital series. :

THE SKELETON OF THE PELVIC LIMB.

§ 11. The bones of the cat’s pELvic Lip are divisible (like those
‘of its pectoral limb) into three categories: A, that of the hip ; B,
that of the hind-leg ; and C, that of the hind- foot. re

A. The skeleton of the hip, or haunch bone, is called the os
innominatum ; and there is one such on either side in the adult
animal.

B. The skeleton of the leg is sub-divisible into (a) that of the
thigh, which consists but of one bone, called the femur; (b) that of
the lower part of the leg, which consists of two bones placed side by
side. The larger of these is called the tibia ; the other, much more
slender and placed on the outer side of the leg, i is called the fibula.
It is also called the peroneal bone of the leg, because it clasps, as it
were, the larger bone.

C. The skeleton of the hind-foot, like that of the fore-foot, is

104 CY ETE CRA a ee
sub-divisible into three parts: (a) that of the ankle, the tarsus;
(6) that of the middle part of the foot, the metatarsus; and (c) that
of the toes, or digits, composed of phalanges, like those of the
digits of the fore-paw. | 4
§ 12. The os 1nnomrnatum is a large bone, which meets its fellow

SN
AF
S
x
NS
SN

i

Fig. 64.—THE PELVIS, SEEN IN FRONT.

a. Acetabulum. p. Pubis.
Crest of ilium. s. Sacrum.
al. Llium. sp. Symphysis pubis.

ip. Llio-pectineal eminence. t. Tuberosity of ischium
o. Obturator foramen,

of the other side in the mid-ventral line of the body, and is strongly
attached to the sacrum (s) above. It thus forms, with the inter-
vention of the last-named bone, a solid bony girdle, called the
PELVIS, supporting the trunk above, and being itself imposed on
the hind-limbs below. The head of the thigh-bone fits into a socket
—the acetabulum (a)—on the outer side of the os innominatum.

This bone consists of two main parts, one above and in front of,
and the other below and behind the acetabulum. The upper portion
forms one continuous piece of bone, but the lower part is perforated
by a large aperture, termed the obturator foramen (0). Hach os
innominatum is made up originally of three distinct bones, which
become united when the cat is full-grown. These three bones are
the éliwm, the ischium, and the pubis.

ey eres Pen a wet

CHAP. Iv.] THE SKELETON OF THE LIMBS. 105

The innominate bone thus consists of three parts :—
(1). An elongated upper part joins the sacrum and extends down
to the socket for the thigh. This is the 1L1um (7). —

E:
Fig. 65.—RicHtT Os INNOMINATUM, EXTERNAL ASPECT.

Fig. 66.—RicuHt Os INNoMINATUM, INNER ASPECT.

a. Acetabulum. { p. Tuberosity of ischium.

ar, Auricwar surface. | ¢. Pubis. ‘

ec. Crest of the ilium. The ilio-pectineal eminence is seen in Fig. A.,
t. Articular surface of pubis, between a and ¢t, and in Fig. B., above ¢, on
a. Ilium. a line with the upper margin of the obturator
tp. Spine of ischium. foramen.

o. Obturator foramen.

(2). From the thigh-socket a bar of bone runs downwards, in-
wards, and ultimately backwards. This is the pubis (Fig. 64,
p, and Figs. 65 and 66, ¢).

"
.
.

106 es THE CAT, , - [cHap. Iv.

(3). Another, stouter, piece of bone curves first backwards from
the thigh-socket, then downwards and forwards till it meets
the pubis.. This is the 1scnrum (Fig: 46, ¢, and Figs. 65 and
66, p).

The dium has a slightly concave outer surface, the upper border.
of which is termed the “crest” (c), and is somewhat convex and
arched. ‘This surface is also called ‘“ gluteal,” because the gluteal
muscles are attached to it. From the front end of the crest the
anterior border descends sharply to the pubis, a blunt prominence
(called the cio-pectineal eminence) marking the point of junction.
Another prominence (the anterior spinous process) projects from
the anterior border of the illum near its summit. From the hinder
end of the crest of the ilium descends its posterior border, the
summit of which is marked by the posterior spinous process, separated
by a wide notch from a small marked prominence, called the spine
of the ischium (ip).

The inner surface of the ilium is slightly concave, forming the
iliac fossa (i) and at its anterior and upper part is a rough irregular
space, called the auricular surface (ar), for articulation with the
sacrum. Theilium forms about the upper third of the socket for the
thigh-bone.

The pusis, or pubic bone, forms the inner part of the thigh-socket,
joining the ilium above, and at its junction contributing to form the
ilio-pectineal eminence. It thence descends inwards (as a band of
bone flattened from without mwards, called the horizontal ramus)
till it meets with its fellow of the opposite side, when it turns sharply
backwards and downwards. The junction of the two pubes is termed
the symphysis (sp), and the part of each pubis next the symphysis is
sometimes called the body; thence the pubis runs outwards and
backwards, as a flattened band, till it meets the ramus of the
ischium. |

The 1scu1um forms the outer and hinder part of the thigh-socket,
and indeed of the whole os innominatum. The body of the ischium
forms about two-fifths of the socket for the thigh, which cavity is
situated on its anterior and outer side. The body is broad, and sends
from its posterior upper margin a slightly marked process, called the
spine of the ischium (7p). Behind this, and behind the socket, the bone
contracts somewhat, and then expands again, the expansion having
a rough, outwardly projecting prominent surface, which is called the
tuberosity of the ischium (p); and it is the two tuberosities (of the
two ossa innominata) which support the body when in the sitting
posture (Fig. 64, ¢). Just below the tuberosity, the ischium sends
forth a flat band of bone (the ramus), which, curving forwards and
downwards, meets the bony band of the pubis spoken of above.
Between the spine and the tuberosity of the ischium the posterior,
upper margin of the bone is slightly concave. :

The socket for the thigh-bone (which has been so often referred
to) is called the acetabulum, or cotyloid cavity. It has a prominent
rim, except at the inner and lower part where the rim is interrupted

CHAP. IV. } THE SKELETON OF THE LIMBS. 107

by a notch (the cotyloid notch). There is no perforation in the

acetabulum, but its surface just within the notch is depressed, the

depression affording attachment to the very strong ligamentum teres
(or round ligament) which goes from’ it to the head of the thigh-
bone.

Enclosed by the ilium, ischium, and pubis, there is an oval space
called the obturator foramen, one such being placed on each side of
the pubic symphysis (0).

The concavity in the posterior border, between the posterior
spinous process of the ilum and the spine of the ischium, 1s called
the greater ischiatic notch ; the other concavity, between the spine of
the ischium and the tuberosity of that bone, is called the /esser
aschratic notch. ;

The width from side to side of the pelvis is about equal to its
depth from the brim of the pubis to midway between the tuberosities
of the ischia. Either of these dimensions is much less than half
the greatest extent of the ossa innominata.

§ 18. The Femur is a bone of about the same length as the ulna,
and, like the humerus, is more or less cylindrical, with a rounded
head above (to fit ito the acetabulum), and with an expansion
below with two articular surfaces.

The shaft, which is nearly straight, is smooth in front, but has an
oblique ridge behind, termed the /inea aspera, which is most marked
about half-way up the bone (/a). :

At the upper end of the shaft are two conspicuous projections.
The external one of these (projecting from the outer margin of the
bone, which it continues upwards), is called the great, or peroneal
trochanter (gt). ‘The internal projection, which is much smaller,
more conical, and rounded, stands out from the imner and hinder
side of the bone, and is called the /esser, or tibial trochanter (It).

Between the two trochanters, on the hinder side of the femur, a
bony prominence extends, which is termed the posterior inter-
trochanteric ridge (7) ; and a very slightly marked line, the anterior
inter-trochanteric ridge, also connects the two trochanters on the
front surface of the femur.

On the inner and hinder side of the great trochanter is a pit,
termed the trochanteric fossa (f).

From between the inter-trochanteric ridges a narrower portion of
bone, compressed antero-posteriorly, projects inwards, forming a
slightly obtuse angle with the shaft. This is called the neck of the
femur (n). It ends in a rounded head (forming a large -part of a
sphere) which (4) fits into the acetabulum.

On the hinder part of the inner side of the head of the femur
there is a very distinctly marked depression, or pit, which serves for
the attachment of the ligamentum teres (p).

On the outer side of the hinder part of the femur, a little below
the great trochanter, is a more or less marked vertical ridge, which
serves for the insertion of the gluteus maximus muscle.

At the lower end of the femur are two rounded prominences,

oly ee ae ee ee ees £eP et eee ee, Se ee eee ee a ee ——

108 , THE CAT.”

elongated from before backwards, and of nearly equal size, named
condyles, separated behind by a median depression (ap).

The external condyle (ec) has on its outer surface a depression for
the tendon of the popliteus muscle. Immediately above this is the

slight prominence of the external tuberosity, immediately above

Fig. 67.—THE RicuT FEMvrR.

A. Anterior aspect. B. Posterior aspect.

which is a small, but deeply marked pit for the tendon of the gastro-
cnemius muscle, and the sesamoid to which that tendon is attached.
The internal condyle is slightly longer, and descends a little lower
down than the external one. On its inner side is a projection called
the internal tuberosity (it).
The articular surfaces of the condyles meet in front, and form an
elongated, transversely concave, ascending articular surface (ap) for

[cHAP. Iv,

CHAP. Iv. | THE SKELETON OF THE LIMBS. 109

the knee-pan. Posteriorly they diverge, leaving between them a
space called the inter-condyloid fossa (if). The femur does not
articulate with the fibula.

Fig. 68.—THEe Ricut FEMOR.

EXPLANATION OF LETTERS IN FIGS. 67 AND 68.

C. External view. la. Linea aspera.

D. Internal view. — lt. Lesser trochanter.

E. Proximal end. o |) avasNeck:

F. Distal end. p. Pit tor ligamentum teres.

ap. Surface for patella. 7. Posterior inter-trochanteric ridge.

ec. External condyle. In Fig. C, a depression may be observed at the
et. External tuberosity. lower end of the shaft posteriorly, just above
f. Trochanteric fossa. the external condyle. It is for the sesa-
gt. Great trochanter. moid to which the gastrocnemius muscle is
h. Head. attached. The depression in the hinder
ic. Internal condyle. part of the external condyle itself, is for
af. Inter-condyloid fossa, the tendon of the popliteus muscle.

at. Internal tuberosity.

§ 14. The knee-pan, or PATELLA, is a small bone of an elongated
oval shape, which is convex in both directions externally, while
internally it is convex transversely, but concave from above down-

110 THE OAT. as - [oHar. rv.

wards, and so fits into the median articular surface at the lower end
of the front surface of the femur.

Saas

——— eee
== SOA

4743

Fig. 69.—Tue Ricut Tre1A AND FIBULA, SEEN
IN FRONT.

A. Tibia. B. Fibula.

Fig. 70.—Tue Ricut TiBtA AND FIBULA, SEEN
BEHIND.

A. The tibia. B. The fibula.

It is attached above by its broad upper margin to the tendon of
the front muscle of the thigh. Below, a ligament goes from its
pointed lower end to the upper part of the shin-bone.

§ 15. The trpta, or shin-bone, is the absolutely longest bone in
the cat’s skeleton. It transmits the weight of the hinder part of
the body from the thigh to the foot.

Its upper end is very wide, and presents two articular surfaces
(condyles)—which are each convex from before backwards, and
slightly concave from side to side (ec and 7c), and which receive the
two condyles of the femur. Between these articular surfaces there

is a depression, or pit, giving insertion to one end of one of the’

crucial ligaments which connect the femur with the tibia.

at

ee ee ee ee ee

—

CHAP. Iv.]

Pe eM ee OES er LU ea ue ee aE Oe Eee en ee a ee a > ae

THE SKELETON OF THE LIMBS. Tit

On the two sides of the proximal end of the tibia are two projec-
tions, respectively supporting the condyles, and called the ezternal

Fig. 71.—THe Rieut TIBIA.

A. Inner surface.

B. Its proximal end.

C. Its distal end,

EXPLANATION OF LETTERS IN FIGS. 69, 70, AND 71.

c.. Crest.

ec. External condyle.

em (Fig. 69, B). Is the external malleolus, the
hinder surface of which is grooved for the
tendon of the peroneus brevis muscle.

em (Fig. 70, B). Is that surface of the external
malleolus, which articulates with the fibula.

et. External tuberosity.

4. Flattened surface for fibula below.

fs. Surface for fibula above.

and internal tuberosities (et and

ic, Internal condyle.

im. Internal malleolus.

is. Inner surface for astragalus.

it. Internal tuberosity.

os. Outer surface for astragalus.

. Descending process.

t. Tuberosity.

Between im and p (Fig. 70, A) is the groove for
the tendon of the flexor longus hallucis
muscle,

it). The external one presents

beneath a very small elongated surface for articulation with the

upper part of the fibula (fs),

112 THE CAT.

The shaft of the tibia is generally triangular in section, being
produced into a sharp crest (c) in front, on the internal side of which
crest the bone is more or less flattened, while it is strongly concave
on its outer side. At the upper end of the front of the shaft is a
prominence called the median tuberosity (¢), or tubercle, which
exhibits a flattened surface for the attachment of the patella.

The lower end of the bone is smaller than the upper. Its lower.

border has a single wide, vertical groove behind for the tendon of
the flexor longus hallucis muscle. Its outer surface is flattened (jt)
for the reception of the fibula. Its inner margin is produced down-
wards into a strongly marked triangular process, called the internal
malleolus (im). This forms the bony projection on the imside of the
ankle, and articulates with the inner side of the tarsus. The
posterior part of the non-articular, or free, surface of the internal
malleolus, shows two small strongly marked vertical grooves, the
anterior of which transmits the tendon of the tibialis posticus muscle,
while the more posterior and outer is traversed by that of the flexor
longus digitorum muscle.

The lower end of the tibia presents an irregular and undulating
articular surface, corresponding with the surface of the tarsus, which
it joins. This surface presents a median ridge running obliquely
backwards and inwards from its front margin, and fitting into the
groove on the upper surface of the astragalus. On the outer side of
the ridge is a rather wide articular surface (0s), which slopes upwards
and outwards; on its inner side is a more concave, but less inclined
surface(és), which becomes continuous with the articular surface borne
by the internal malleolus. The hinder margin of the articular sur-
face of the tibia (when the bone is vertical) descends slightly below

its front border, which nevertheless exhibits a descending process (p) ~

which corresponds with the front end of the median ridge just
described.

§ 16. The Fisuta is the slenderest bone, in proportion to its
length, in the body, and extends on the outer side of the leg from
close to the knee down to the ankle.

Its upper extremity is slightly enlarged into what is called the
head, which articulates with the outer side of the head of the tibia,
and gives insertion to the external lateral ligament. It does not
mount upwards so high as does the tibia, and its outer surface is
concave.

The shaft of the bone is irregularly triangular in section. Its

lower end is expanded into what is called the external malleolus,
which forms the bony projection on the outer side of the ankle, and
articulates with the outer side of the tarsus.

This malleolus does not project downwards so far as does the
internal malleolus. On its inner side it articulates anteriorly with
the outer side of the lower end of the tibia (as already mentioned)
below and behind this it articulates with the outer side of the
astragalus. The external malleolus is deeply grooved behind for
the passage of the tendon of the peroneus brevis muscle, while that

[ouarya | oe

Je 2s a Pus -
a es

ao ee’

vee

omar. r1v.] THE SKELETON OF THE LIMBS. 118

of the peroneus longus muscle passes in front of the external
malleolus.

Thus, altogether we have at the lower end of the cat’s leg, a
median horizontal surface for the tarsus, with two other articular
surfaces, at right angles with the horizontal one, and formed by the
surfaces of the malleoli.

§ 17. The Tarsus consists of seven bones (none of which can be
called “long bones”), namely the astragalus, calcaneum, cuboides,
naviculare, and three cuneiform bones. All these are so firmly
connected by ligamentous fibres which envelope them, that very
little mobility is possible, though there may be a very slight rotation
of the distal tarsal bones upon the proximal ones, that is, upon the
astragalus and calcaneum.

The movement of the foot on the leg, however, takes place entirely
by the hinge-like joint by which the tarsus articulates with the bones
of the leg.

The astragalus receives the weight of the trenk from the tibia,
and is a short irregularly shaped bone (Fig. 73, as), with a “ body,
neck, and head.” :

In its natural position in walking, when the foot rests on the
ground only by its toes (the heel being raised high up) the upper
surface of the body of the astragalus (by which it articulates with
the under surface of the shaft of the tibia) looks forwards as well as
upwards. ‘l'wo other articular surfaces, almost at mght angles with
the former, join the two malleoli respectively, that for the internal
malleolus being much the larger. The posterior surface of the body

_ 1s grooved for the tendon of the flexor iongus hallucis muscle. The

anterior part of the bone is prolonged forwards as its neck, ending
in a rounded, convex, articular surface (the head), which fits into
the hinder surface of the naviculare (n). The anterior part of the
dorsum of the bone presents a concavity, which gives origin to the
extensor brevis digitorum muscle, and also affords attachment to a
tendinous loop through which pass the tendons of the extensor
longus digitorum muscle.

The caleaneum (or os calcis) is the bone of the heel (0c), and is by
far the largest bone of the tarsus. It is rather more than twice as
long as broad, and is somewhat expanded at its hinder end (called
its tuberosity), which, is vertically grooved to allow the tendon of
the Plantaris muscle to play over it (Fig. 72, oc’). The caleaneum
articulates with the astragalus above and with the cuboid in front.
It developes a process on its inner side (#) to support part of the
last-named bone, and another smaller process (oc?) on its outer side
just before joining the cuboids.

The naviculare (or scaphoid of the foot) is, on its dorsal surface,
wider than long (Fig. 73, 2). Behind, it is deeply concave for the
reception of the head of the astragalus. In front it presents three
surfaces for articulation’ with the three cuneiform bones. That for
the middle one is convex. 7

Its inner margin sends backwards a long process, called its

I

Pe, eee ee ee es Sn ere ene ee ee ee ee ee re a =

414 aL pau SPA Can

tuberosity, which extends (n’ and %) beneath (7.e., on the plantar i
side of) the head of the astragalus and supports 11. ae

Gc,

WV
WT
BONES OF RIGHT HIND-PAW.
Fig. 72.—PLantTarR SURFACE. Fig. 73.—Dorsau SuRFACE,

a. Hood to enclose root of claw. p?. Middle phalanx,
as. Astragalus. p®. Distal phalanx.
6. Process to sustain claw. t. Ecto-cuneiform.
cb and ch. Cuboides. tcp. Its hooked plantar process.
oc. Os calcis. w. Tuberosity of naviculare, as seen on dorsal ;
ocl. Inner process. surface. .
oc. Outer process of os calcis. x (Fig. 72) inner process of os calcis.
oc’, Groove for tendon of Plantaris. x (Fig. 73) the tuberosity of fifth metatarsal.
mc. Meso-cuneiform. I. Hallux, only represented by its metatarsal.
mt. Metatarsals. II. Index.
m', Tuberosity of Naviculare, as seen on the III. Medius.

plantar surface. IV. Annulus.

mc. Ento-cuneiforme. V. Minimus. © ak.
p'. Proximal phalanx. ot

CHAP. Iv.] THE SKELETON OF THE LIMBS. 115

Of the three cuneiform bones, the outermost one—ecto-cunei-
form, is the largest, and the meso-cuneiform is the smallest, and is
not to be seen on the plantar surface of the foot. The ento-cunei-
form is longest from behind forwards. It presents behind a concave
articular surface for the naviculare. Above it has posteriorly a
concave articular surface for the meso-cuneiform, and anteriorly a
much smaller one for the second metatarsal. In front it has a flat
surface (elongated from the dorsum to the plantar aspect) for the
rudimentary first metatarsal. The imeso-cuneiform is.a wedge-shaped
bone with its broad end on the dorsum of the foot. Behind it presents
a concave articular surface for the naviculare, and it has another
concave articular surface in front for the second metatarsal. The
ecto-cuneiform has both in front and behind a large articular surface,
broad dorsally, and narrow towards the plantar surface. The former
articular surface is for the naviculare, the latter for the third meta-
tarsal. It has also on its inner side a small articular surface for the
meso-cuneiform, and on its outer side a much larger one for the
cuboides. The hinder, or proximal part of its plantar surface sends
downwards and distally a strong hook-shaped process (¢cp), between
which and the plantar surface of the bone, the tendon of the
peroneus longus muscle passes.

The cuboides, placed on the outer side of the tarsus (cb), articu-
lates with the os calcis behind, and with both the fourth and fifth
metatarsals in front. Its inferior surface is traversed by a deep
groove (for the tendon of the peroneus longus muscle), behind which
is a prominence for the attachment of a ligament.

§ 18. The merararsvs consists of four elongated bones (the
shortest of them being more than half the length of the radius), and
one excessively short and rudimentary one (1) which is placed on
the inner or tibial side of the other four.

The four long metatarsals are much more elongated than are the
corresponding metacarpals, and the second of them (that of the third
digit or medius of the foot) is also much stouter than is any one of
the latter.

The innermost metatarsal is the only bone which represents the
first or innermost digit. It is called the hallux, and corresponds with
the pollex of the fore-paw. This first metatarsal is a minute conical
bone, smaller even than the meso-cuneiform. It has an oblique
articular surface at its proximal end, which articulates with the
ento-cuneiforme, while on its inner side is another articular surface
for the second metatarsal.

The four outer metatarsals have their bases or tarsal ends en-
larged, and each provided with a proximal articular surface (dif-
ferent in shape in each metatarsal) for the tarsus, situated in a plane
nearly at right angles with the long axis of each respective meta-
tarsal. The proximal articular surface of the second metatarsal is
small and triangular; that of the third is very large and crescentic ;
that of the fourth is moderate in size and quadrangular ; that of the

12

116 | THE CAT. [ouap. rv.

fifth is very small and oval, and with a long process or tuberosity .

extending backwards on its outer side (7).

The shafts of the four outer metatarsals are flattened dorsally and

on their plantar surface, and where they are in contact towards their

roximal ends. That of the medius is the longest and the stoutest;
that of the fifth digit is the most slender, and that of the index of
the foot, the shortest. Each of these four outer metatarsals develops
a rounded head at its distal end, which articulates with the concavity
on the hinder end of the proximal phalanx of the corresponding
digit. As in the corresponding part of the metacarpals, there is a
prominence developed at the middle of the ventral surface of each
such distal, articular head —a sesamoid bone playing in the concavity
which exists on each side of such prominence.

§ 19. The pHALANGess are three in number in each digit, except
the first or hallux, which is devoid of any. :

In form and arrangement the phalanges of the hind-foot closely
resemble those of the fore-foot, except that the proximal ones of the
outermost (peroneal) digits are longer and stouter.

§ 20. The aARTICULATIONS AND LIGAMENTS OF THE PELVIC GIRDLE
are as follows :—

In the first place, each ium is united to the adjacent auricular
surface of the sacrum by cartilage which there coats both bones, and
forms what is called the sacro-iliac synchondrosis. Ligaments called
the dorsal and ventral sacro-iliae ligaments strengthen this articula-
tion on each side. The pubes are joined together at the symphysis by
the help of a fibro-cartilage, and by superior and inferior ligaments.

The obturator foramen is closed by means of the obturator mem-
brane (or ligament), which is attached to its margin or inner edge. - _

The socket offered by the bony pelvis to the head of the femur is
deep, but it is made still deeper by the cotyloid ligament, which
surrounds its margin and bridges over the notch at its lower part,
forming there what is called the transverse ligament.

The movements of the thigh, therefore, though still extensive, are
more restrained than those of the fore-limb at the shoulder-jomnt.
The head of the femur is held in its socket in part by a very strong
ligament called the ligamentum teres, which is at one extremity con~
tinuous with the transverse ligament, while at its other end it is
inserted into the pit on the head of the femur.

The joint is surrounded by a capsular ligament, strongest in front,
attached above to the margin of the acetabulum and the transverse
ligament, and below to the intertrochanteric line in front, but at a
higher level behind. It is lmed by synovial membrane.

The ARTICULATIONS AND LIGAMENTS OF THE HIND-LEG are eX-
ceedingly complex.

The internal lateral ligament (Fig. 74, 7) extends from the internal
tuberosity of the femur to the inner tuberosity of the tibia. The
tendon of the semi-membranous muscle (sm) passes between it and
the bone.

CHAP. IV.] THE SKELETON OF THE LIMBS. 117

The external Jateral ligament, very strong and distinct (e) passes
as a flattened cord from the external tuberosity of the femur to the
head of the fibula.

The posterior ligament (p) is a narrow band extending obliquely
upwards from the outer part of the summit of the tibia to the
internal condyle of the femur.

A B

Fig. 74.— LIGAMENTS, WITH SOME MuscULAR INSERTIONS; OF*THE KNEE-JOINT,
A. Seen posteriorly. l. Inter-osseous ligament.
B. Seen externally. p. Posterior ligament.
ae. Anterior crucial ligament. po. Patella.
b. Biceps muscle. pc. Posterior crucial ligament.
c. Upper attachment of capsular ligament. s. Inter-articular cartilage.
e. External lateral ligament. sm. Semi-membranosus.
ed. Extensor lougus digitorun. tf. Tibio-fibular ligament.
g. Gastrocnemius. tp. Ligament of the patella towards its inser-
z. Internal lateral ligament. tion.

The ligamentum patelle (tp) is a strong fibrous band proceeding
upwards from the anterior tubercle of the tibia to the lower end of
the patella. The patella (pa) is supported above by the tendon of
the rectus muscle which is inserted into it, and indeed, the liga-
mentum patelle may be viewed as the inferior termination of that
tendon, and the patella itself as a large sesamoid bone. This
ligament aids powerfully in preventing the flexion of the knee
forwards, there being in the leg no process like the olecranon of the
ulna to prohibit (by the mere shape of the leg-bones themselves) a
bending of the joint in the wrong direction.

Two other fibrous bands, termed the crucial ligaments, are placed
in the centre of the knee-joint, and slightly cross each other,
whence their name. The anterior (or external) one (ae) goes from

a re ee ee | me ed a
1 se ths Ng et ae A
P r Le 4 aa

118 THE CAT. [CHAP, IV

the pit between the condyles of the tibia to the inner and posterior
- part of the external condyle. The posterior (or internal) one (pe)
goes from a more posteriorly situated part of the same pit to the
front part of the concavity between the condyles or the outer side of —
the inner condyle. ‘Two fibro-cartilaginous crescentic structures (s),
the semi-lunar cartilages, are inter-
posed between the femur and the
tibia, reposing on the outer and inner
margins of the upper surface of the
latter.

A capsular ligament surrounds the
knee-joint incompletely, being deficient
beneath the tendons of the muscles,
and in the regions occupied by the
other ligaments.

A very large membrane of the kind
called synovial (the largest such mem-
brane in the cat’s body) lines the knee-
joint, extending up above (and within) ©
the patella, and investing the crucial
ligaments in front, and both surfaces of
the semt-lunar cartilages.

The upper ends of the tibia and
fibula are connected by two small flat
and oval surfaces, bound together by a

Fig. 75.—VERTICAL SECTION THROUGH

KNEE-JOINT. tibio-fibular ligament (tf) passing from

a Anterior tt Mgament cut the head of the fibula to the external
tte mont tuberosity of the tibia. :

ff (Above) femur. An inter-osseous membrane, or liga-

F. nthe join) atiporetissne ment (7), passes from the external

eye oarecaneia ene ridge of the tibia to the adjacent

_" Inter-articular cartilage: surface of the fibula. It does not

ascend quite to the summit of the
interval between the leg-bones.

The ARTICULATIONS AND LIGAMENTS OF THE FooT are so closely
connected with those of the inferior ends of the leg-bones that these
latter may best be described with the former.

The ANKLE-JOINT is strengthened by anterior and posterior liga- —
mentous bands.

The internal lateral ligament of the ankle-joint passes down
(broadening as it descends) from the end of the internal malleolus
somewhat to the astragalus and oscalcis, but especially to the tube-
rosity of the naviculare.

The external lateral ligament also radiates as it descends from the
lower end of the fibula to the os calcis. The internal malleolus
descends somewhat below the external one, and the tibia descends a
little more behind the astragalus than it does in front of it.

A certain amount of motion is possible between the distal tarsals,
and the astragalus and os calcis—a movement facilitated by the
presence of synovial membrane. |

| ia =e Lt ee 2 ee ee he ee

CHAP. Iv.] THE SKELETON OF THE LIMBS. 119

A strong interosseous ligament proceeds vertically downwards
from the groove on the under surface of the astragalus to the
depression on the dorsum ot the os calcis. |

A plantar ligament, called the calcaneo-sesphoid, connects the
plantar surface of the naviculare with the os calcis, and so helps to
sustain the anterior part of the astragalus. Another ligament,
called the long plantar, joins the under surface of the os calcis with

the cuboid and tuberosity of the fifth metatarsal. A variety of
other ligaments connect one with another the various more distally
situated tarsals.

The metatarsal bones are connected with the distal tarsals by
dorsal and plantar ligaments.

A transverse metatarsal ligament connects the distal ends of the
metatarsals as in the fore-foot.

Ligaments connect the metatarsals with the phalanges, and the
phalanges with one another in the hind-foot in the same way as the
metacarpals and phalanges are severally connected in the fore-paw.

§ 21. A GENERAL view of the pelvic appendicular skeleton of
the cat shows us that it forms a complete bony girdle, being im-
mediately attached (at the sacrum) to the axial skeleton dorsally.
Ventrally its two sides meet together uninterruptedly at the pubic
symphysis, and there are two ventral bars, the pubis and ischium,
instead of only one, and that incomplete, as in the pectoral arch.
The knee-joint is so bent as to open backwards, and thus the digits
of the hind-foot are applied to the ground without the need of any
pronation of the limb-bones.

The skeleton of the leg and foot is divisible mto a tri- and
bi-digital series placed side by side.

Thus there is first the tibia; the astragalus and naviculare; the
three cuneiform bones; the first, second, and third metatarsals, and
the index and middle digits—forming the tri-digital series.

We have secondly, the fibula; the caleaneum and cuboid; the
fourth and fifth metatarsals ; and the annexed digits—forming the
bi-digital series.

§ 22. Thus it is evident that there is a GREAT CORRESPONDENCE,
and at the same time a certain DIFFERENCE, between the skeletons
of the pectoral and pelvic limbs.

The most notable correspondences are the expansion of the dorsal
bone of each limb-girdle; the existence of a single bone with twe
eminences (tuberosities or trochanters) in the proximal limb-segment,
and of two bones in the distal limb-segment; the agreement in
number of the carpal and tarsal bones, of the metacarpals and meta-
tarsals, of the epiphysial ossifications of these, and the corre-
spondence in number of the phalanges, except those of the pollez
and hallux.

Thus these limb-skeletons are evidently modifications of one type.

The most notable differences are (1) as regards the dorsal attach-
ments of the limb-girdles, and (2) the degree of complexity of their
ventral parts; (3) the fact that the outer or radial tuberosity in the

iia. |

120 THE CAT. - [cHap, Iv.

humerus is the larger, while in the femur it is the inner or peroneal
one; (4) that the ulna is the larger bone in the arm, while the
fibula is much the smaller in the leg; (5) that the ulna is the main
element of the elbow-joint, while the fibula is excluded from the
knee-jomt; (6) that the ulna sends up a very large process (the |
olecranon) at its proximal end, while the fibula sends up no process
at all; (7) that in the knee-joint there is a patella, while there is
no such structure in the elbow-joint; (8) that the tarsus is grasped
between the malleoli, while so complete a graspisnot given by the arm-
_bonestothe carpus; (9) that there is no bone so large, either absolutely
or relatively, in the carpus, as is the os calcis in the tarsus; (10)
that the pollex rests on a saddle-shaped surface, and is slightly
separable from the other digits, while the rudimentary hallux rests
on a nearly flat surface, and has almost no mobility; (11) that the
metatarsals are long as compared with the metacarpals; (12) that
the tarsus is much longer than is the carpus; (13) that the hallux
is much more rudimentary than is the pollex.

Though many of these differences are incapable of reduction, yet
others disappear, and SERIAL HOMOLOGIES become more manifest,
if the limbs be placed in that position which is primitive in develop-
ment, z.e., if both the knee and elbow be turned outwards. ‘Then
the pollex and hallux, and the ulna and tibia, stand in corre-
sponding positions in relation to the long axis of the body.

As to which parts of the os innominatum answer to the several
parts of the scapula, different views may be maintained; but if the
lower end of the scapula be rotated outwards, then its subseapular
fossa will be seen to answer to the gluteal surface of the ilium, the
acromion to the ischium and the coracoid to the pubis, the infra-
spinatus and iliac fossee corresponding. |

Undoubtedly the femur, is the serial homologue of the humerus,
and its great trochanter, of the lesser tuberosity ; the radius, of the
tibia; the ulna, of the fibula; the astragalus, of the scapho-lunar bone;
the ento-cuneiform, of the trapezium; the cuboides, of the unciform,
and the hallux and other pedal digits are the homologues of the pollex,
and the other digits of the hand.

§ 23. Such being the main facts as to the structure of the internal
skeleton, before concluding the subject a few words are needed with
respect to the sornts. For, as has been already pointed out, the
bones serve as points of attachment for the moving organs or muscles
which make use of them as so many levers or fulcra, as the case
may be.

In order that this motion of the bones may take place easily, the
interposition is required of certain accessory structures between. bony
surfaces which move one upon the other. Some bones, however,
are united by surfaces which join without any such intervention—
no motion taking place at the line of junction of such bones.

Jomsts may be of three sorts: I. immovable; II. mixed; or
IIL. movable.

The IMMOVABLE joints (synarthroses) may be (1) such as those

CHAP. IV.] THE SKELETON OF THE LIMBS. 121

which take place befween certain bones of the skull where, as we
have seen, an interdigitation of the processes of their irregularly-
shaped margins takes place, forming what is called a dentated or
serrated suture (as between the parietals or frontals) ; or (2) such as
those between the upper jaw-bones, where there is no inter-
digitation, and where the adjoined even edges form what is termed
an harmonia or faise suture; or (3) such as that formed by the
temporal bone with the parictal, where the adjacent margins are
bevelled off and one overlaps the other, forming what is called a
squamous suture; or (4) such as that between the ethmoid and the
vomer, where a ridge of one bone is received into a groove in
another which is called schindylesis; or finally (5) where one hard
part is received into the cavity of a bone, as the teeth fit into the
jaws, a mode of union named gomphosis.

In all the immovable joints no cartilage is mterposed, there being
only periosteum, such as coats all bones.

The great majority of the bones, however, are intended to move
one upon another, and are on that account joined together by means
of some other and thicker substance than the periosteum.

The MIxeD or imperfect joints (amphiarthroses) have, however,
very little mobility, and their adjacent parts do not present smooth
surfaces, but are connected by fibrous-tissue or continuous cartilage,
or both.

Examples of such joints are to be found in the junction of the
haunch-bones with the spine, or in that formed by the bodies of the
vertebrae one with another. These latter are connected, as we
have seen, * by discs, each consisting, towards its circumference, of
fibres running obliquely upwards and downwards, and in its middle,
of a pulpy substance containing many cartilage corpuscles. These
pads, while allowing very little movement between any two adjacent
bones, give a considerable amount of mobility to the whole series.
They also serve to prevent shock.

In all MovaBLE or complete joints (diarthroses) the opposed ends
of the bones are covered each with its own distinct, separate, and

very smooth cartilage, and thus the bones can glide freely on each
other.

In addition to this, however, each complete joint is provided (as
has been already indicated in various instances) with a kind of bag
containing a viscid fluid. This bag, at first complete, comes in
adult life to be attached to each of the cartilaginous. surfaces,
near its border, and to disappear altogether over the central part of
each such cartilage. By the fluid thus interposed between the
cartilages all friction is avoided, and a perfectly smooth, easy, and
even motion is provided for.

The fluid is termed synovia, and is an albuminous liquid commonly
ealled ‘‘joint-oil,” yet it is not really of an oily nature, although it
contains some fatty matter.

* See ante, p. 52.

122 | THE CAT. (CHAP. Iv.

The bag, formed of areolar tissue lined with scaly epithelium, is
called the sYNOVIAL CAPSULE or membrane. It is more or less
connected with the fibrous bands, or ligaments, which bind the
bones together in the neighbourhood of tke joints and generally
help to restrain movement to certain directions.

20 certain joints, as in that of the cat’s knee, additional structures
are interposed, called INTER-ARTICULAR CARTILAGES. These are
formed of fibro-cartilage, and, though placed between the bones, are
not within the cavity of the synovial sac, but attached to its outer,
surface, which is so folded or doubled as to embrace them.

Movable joints are of different kinds, with corresponding diversities
of form. ‘Thus they may be such that the bones are capable of
nothing more than a slight gliding movement one on the other, the
apposed articular surfaces being nearly flat and even. Such joints
are termed PLANIFORM, Or ARTHRODIA, and as examples may be
selected the bones of the carpus and tarsus.

A second kind of joint is that called BALL-AND-SOCKET, 0r ENAR-
THRODIA, where one rounded portion of bone is received into a
corresponding cup or socket. When the cup is very deep, the cavity
is said to be coty/oid—as in the hip-jomt; when it is shallow, it is
said to be glenoid, as in the shoulder. The shallower is the cavity,
the freer and wider is the power of motion. If the terminal con-
vexity is elongated it is termed a condyle—as is the articular head
of the lower jaw.

A third and a more complex kind of articulation is called a
HINGE Or GINGLYFORM JoINT, and is also called pudley-like or
trochlear. In such joimts the surface of one bone is more or less
cylindrical, and fits into a corresponding socket. The former gene-
rally exhibits a median groove with a projection on each side of it,
while the other bone has a corresponding median prominence bordered -
by two concavities; but various arrangements of opposing curves may
exist, tending to limit motion more or less completely to one plane. The
best example of such a joint is that of the elbow, a more imperfect
one is that of the knee, This kind of joint may be so complicated
as to form what is called a double hinge-joint (as between the meta-
carpal of the pollex and the trapezium). In that articulation each
bone is concave in one direction, and convex in the direction at right
angles with the former, that 1s to say, each bone presents a saddle-
shaped surface, and the two articulate together, as a rider is placed
with respect to the saddle he bestrides.

There is another kind of joimt, rarely found, and termed a RING
and COLLAR-JOINT, or lateral ginglymus. It is when the head of a
bone is received into a strong ring or collar, formed of ligament,
which allows the bone to rotate round its own axis. Such a joint
exists between the upper (proximal) parts of the two bones of the
fore-arm. -

The last kind of joint to be noticed is that called a Pivor-JsorNnT,
an example of which is furnished by the two uppermost bones of the
neck. Here one bone serves as an axis or pivot on which the other

CHAP. IV. ] THE SKELETON OF THE LIMBS 123

can rotate. It resembles in principle the joint last noticed, but here
the part bearing the ring (which ring is formed partly of bone, partly
of ligament) itself turns on the bone, which traverses it instead of the
reverse.

Certain ligamentsare called ELASTIC LIGAMENTS, becausethey contain
elastic tissue, and so serve to sustain weight, and overcome persistent
resistance, without the necessity of expending any muscular power.
Such are the ligaments between the neural arches of the vertebrex
and their continuation onwards to the occiput (to support the head),
as the ligamentum nuche.

CHAPTER V.

THE CATS MUSCLES.

§ 1. Tus cat performs conspicuous general bodily movements—
locomotive actions, such as walking, running, and jumping—and also
anumber of movements of various portions of the body. Some of its
movements resemble those which are executed by ourselves at will,
and therefore called “voluntary motions;” others resemble those
which ‘we know to be in ourselves automatic, or voluntary.

Amongst the voluntary movements are the various movements of
the several members, such as the tail, the tongue, &c., together with
those by the aid of which the animal may change its facial expres-
sion, or may give audible expression to its various feelings.

Amongst its involuntary or automatic movements are those which we
shall find take place in the heart, intestines, and in other viscera.

All these motions, of whatsoever sort, are performed by muscles
of different kinds, shapes, and sizes. |

It is of muscles that the bulk of the cat’s body—that is to say, all -
its “flesh ”’ (by investing
the endo-skeleton as it does), largely determines the shape of the
trunk and limbs, though its essential function is the production of
motion.

The study of the muscles is called myonoey.

The muscular system of the cat consists of masses of very different
sizes and shapes, arranged in most various aggregations of muscles,
such aggregations being separated from each other by delicate
sheets of connective tissue called fascice or aponeuroses. Yet more
delicate fibrous membranes invest every single muscle, and penetrate
between its component portions, conveying nerves and blood-vessels
to them.

Other skeletal structures with which the muscles are directly
connected, are those dense bands of connective tissue already
referred to as ‘‘ tendons.

§ 2. Muscular substance constitutes a peculiar il of tissue. It
is a motor tissue because it has the power of producing motion by
“contraction,” that is, by an alteration m its shape which affects
the parts of the body to which it is attached. It has also a special
chemical composition. It is made up for nearly three-fourths of

CHAP. V.] THE CAT'S MUSCLES. 195

its substance of water, while about fifteen per cent. of the remaining
fourth is found, after death, to consist of an albuminoid substance
called syntonin, or muscle fibrin,* which is soluble in dilute hydro-
chloric acid. It seems, however, that this post-mortem condition
differs from what is found in life, when the muscle-fibrin is fluid,
and has been termed myosin. Muscle-fibrin contains some fifteen
per cent. of nitrogen. Other nitrogenous substances termed kreatin
and kyeatinine, are present in very small quantities, as also sume
non-nitrogenous ones, such as grape-sugar, lactic, butyric, acetic,
formic, and uric acids, with some other substances.

Muscular tissue is of two kinds, called respectively srripED and
UNSTRIPED. ‘The unstriped tissue takes part in the formation of the
alimentary canal and other viscera, such as the bladder. Jt also
exists in the walls of the blood-vessels, and generally in parts the
actions of which, in man, are not under the control of the will
Striped muscular tissue, on the contrary, makes up the substance of
all those muscles which answer to such as in us are amenable to the
will, together with some parts which act ivoluntarily—as the heart.
This striped kind is the more complex in structure.

UNSTRIPED MUSCULAR TISSUE, as the more simple, may be first
noticed. It is pale, translucent, and made up of a number of roundish
or flattened fibres from the =,!;, to the —,45 of an inch in breadth,
devoid of any limiting membrane, more or less fusiform in shape,
and marked at intervals with oblong corpuscles. ach fibre is made
up of bodies termed muscular fibre cells, of an oblong, flattened
shape, of agranular substance, and containing an oval or rod-shaped
nucleus. The nuclei become very distinct when the fibres are treated
with dilute acetic acid. As well as forming fibres, those cells may
be mixed up with other tissues, as, e.g., in the dermis (where some
of them, by their contraction, may make hairs “stand on end” in
the way before spoken of), or they may form broad layers of inter-
lacing fibre-cells. They are never attached to bones. Sometimes
they bifurcate at one end. }

STRIPED MUSCULAR TISSUE consists of fibres which are generally
collected in larger or smaller bundles termed fasciculi (Fig. 76, A),
each fasciculus being furnished by a membranous envelope sent in-
wards from the sheath, or perimysium, which invests the whole
muscle, except in the heart, where the fibres are naked. Each
fibre (B) has a membranous transparent investment called the
sarcolemma (Fig. 76, B e), which is of the nature of elastic tissue.
The fibres average about ;1, of an inch, but may be somewhat
larger or much smaller.

Within the wall of the sarcolemma, there may be at intervals elon-
gated corpuscles, but the special characteristic of fibres of this tissue is

* Fibrin is the name given to the soft, { men, but differs by its property of spon-
whitish, stringy substance, which may be | taneous co-agulation. See the description
obtained from fresh blood by whipping | of the blood, Chapter VII., § 2.
it with fine rods. It is very like albu-

ae a. ee! ee ee ee eee ee ee ee

126 big THE CAT.

the appearance of a number of alternating, exceedingly regular, trans- =
verse markings, such stration depending on a regular arrangementof
alternate parts with different refractive properties. ach striation

fi
Kl
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he
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Mi
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i

IN
MN)
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Wi

to
my

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WDD»

Ni
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MN)

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Ww
AN

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ANNI

it

My

NNN

nN

)
NN

——

TM

pi NW

WN

—— Fi

HAY
Ly)

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MN)
N

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a
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SS
Hime

Ly
7
XO
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ly We
ite
TR
KINA \
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7
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2

Fig. 76.—StrIPED MUscULAR TISSUE OF THE CAT, GREATLY MAGNIFIED. :

A. Bundle or fasciculus of fibres. d. One of the clefts.

a. Cut end of a fibre. e. Investing membrane or sarcolemma, seen i
b. A fibre. at a point of rupture. The sarcolemma is

c. A fibre broken up into its component fibrils. twisted, but not broken. =

B. A fibre, with parts of two others. The fibre C. Fibrilla of different magnitude (f, g, h,) very ;

has been split at right angle to its long axis, greatly enlarged.

consists of a central narrow dark line (the svptal line), on each side
of which is a narrow transparent space (the septal zone), while be-
tween the transverse striations is a much larger space (the inter-
septal zone), and these larger parts constitute the main substance of
the fibre and therefore of the muscle. The appearance. thus pre- |
sented is that of a number of opaque discs embedded, at regular
intervals, in a more translucent substance.
Faint indications of longitudinal division may also be detected, 4
and after immersion in alcohol, or a weak solution of chromic acid,
each fibre may be broken up into a number of very much more
minute ones termed fibrille (Fig. 76, C), each fibril still presenting
the transverse striation, It is, however, by no means sure that each i,
fibre is really made up of naturally distinct fibrille, since, when
treated with much diluted hydrochloric acid each fibre may be broken
up into (B d) a number of thin discs, parallel to and coinciding with |
the transverse striations. In the heart, the fibres are branched. r
§ 3. Muscuzar conrraction (which takes place under certain :

(OHAP. V.] THE CAT’S MUSCLES. 127

conditions and excitations), not due to any mere physical or chemical
change, but is a vital action. The capability of being acted on by
such excitations is called irritability, and the special form of irrita-
bility possessed by muscle is called CONTRACTILITY.

This contractility may be seen to act in a single fibre, and it is by
the simultaneous action of the fibres composing it that each muscle
performs its proper function, and contracts as a whole.

The chauge of shape referred to, is a temporary shortening of the
fibres in length, with a consequent transverse enlargement. It is a
familiar fact that when, in ourselves, the fore-arm is bent upwards a
temporary swelling takes place on the front of the upper arm. ‘This
is due to the thickening which accompanies the shortening of the
muscle mainly employed in effecting such movement.

The contracted state of any muscle can only endure for a limited
period, and cannot be repeated without an interval of rest, which
must be greater according to the exhaustion induced by frequently
repeated contractions. ‘There is one muscle, however, which acts
throughout the whole of life, the contractions beimg continually

reiterated after short regular intervals of rest. This muscle is the

heart, which takes its needful interval of repose after each contraction.

Unstriped muscle contracts slowly and but slowly relaxes, while
striped muscle can contract suddenly and be suddenly relaxed. In
certain pathological states, as, e.g., in lockjaw, muscular contraction
may be greatly prolonged.

The amount of force with which a muscle contracts depends on
the number of its fibres, but the length of the muscle determines the
degree of shortening which can be effected.

The irritability of muscular tissue persists for a certain period
after death, which varies somewhat according to the cause of dissolu-
tion—speedily disappearing after death from poisoning by noxious
vapours, or from hghtning, while occasionally it has been found in
man to persist for twenty-four hours after death. Sixteen hours,
however, is the ordinary limit, even of that part of the heart (the
right auricle’ which was called by Galen the “ ultimum moriens,”
on account of its long-enduring irritability. This property persists
very much longer in cold-)looded animals, e.g., the frog.

The agent which induces muscular contraction is called a stimulus,
and there are various kinds of sTIMULI.

Thus, there may be a direct stimulus, such as the application to
the muscular fibres of a sharp-pointed body, or of an acid or some
acrid substance, or by sudden heat or cold, or by a shock of
electricity.* There may also be an indirect stimulus, 7¢.e. when the
excitation is applied not directly to the muscular tissue, but to the
nerves distributed to it, or there may be a mental stimulus due to
emotional excitement. Stimuli, physically equal, have a more

_ powerful effect when acting on a muscle through a nerve, than

when acting directly on the muscle itself.

* The resistance of a muscle to elec- , transversely as it is in the direction of its
trical conduction is seven times as great | length.

128 THE CAT, [CHAP. V.

Shortly after death a peculiar rigidity of the muscles soone: or
later sets in,which may be so intense that rupture of tissue will take
place rather than change of posture, if force be applied to produce the
latter. This is the death-stiffening, or igor mortis.

This rigidity does not alter the position im which the limbs may
happen to be when it sets in.* It appears to be due to a solidifica-
tion (coagulation) of the fluid substance of the muscular tissue.

The occurrence of rigor mortis is a certain proof that death has
taken place.

§ 4. Muscular fibres being thus aggregated, as has been said,
into various masses termed muscles, the number of these masses
may be estimated at some 500 in the cat. They vary greatly in
size, in weight, in form and in the arrangement of their fasciculi.
Generally, the fasciculi are arranged longitudinally in a more or less
parallel manner, and end by insertion side by side into a tendon;
but sometimes they radiate from a central band of dense fibrous
tissue (or tendon) in a penniform or semi-penniform manner. Some-
times they are arranged in a concentric manner round apertures,
when they are called sphincters ; or in a cylindrical manner, as in.
the walls of the alimentary canal. They may have, as in the last
named instance, no connexion with bone, but generally they are
attached to bones which they employ (as we shall shortly see) as
levers or fulcra, and are then generally inserted by means of those
dense bands of parallel fibres of connective tissue called tendons.

The fleshy mass of a muscle is called the belly, and there may be
two such bellies with an intermediate tendon. Such a muscle is
termed digastric. A muscle may arise by two or more heads, when
it is called b7- or tri-cipital, as the case may be.

That end of a muscle which is nearest to the central axis of the
whole body, or to the root, or axis of the limb of which it forms
part, is generally called its ornterN, or its ‘‘ proximal end.” The
opposite extremity is generally called its InsERTION, or its “ distal
end.”

Muscles acting on bony levers produce definite motions of different
kinds, according to the circumstances of their application. This
difference of functions causes them to be distinguished by certain
generic terms, each such term being applied to all such muscles as
produce a motion of the kind denoted by the term.

Thus, muscles which bend a joint so as to make the angle formed
by two. long bones acute, or which move the digits towards the
palmar or plantar surfaces of the feet, are termed rLExors. Those
the function of which is antagonistic to these are termed EXTENSORS.

Some muscles attached to a long bone which 1s relatively fixed at
one end, tend to make it describe the superficies of a cone, or a
movement of circumduction. Such muscles are termed ROTATORS.

* Occasionally after death from cholera | ject; but these are probably due to séme
and yellow fever, distinct movements | action of decomposition on parts of the
have been observed in the human sub- | nervous system.

ES we ee

CHAP. V.] THE CAT'S MUSCLES. 129

Some muscles move a bone away from a given axis, and are
therefore termed abductors. Others tend to bring it towards such
an axis, and such are called adductors. The epithets “ protractors,”’
“‘yvetractors,”’ “ elevators,’ and “ depressors,” (terms which require
no explanation), are also sometimes made use of.

There cannot, however, be any really good classification of muscles
according to the functions they execute, because such functions may
vary in different animals with regard to the very same muscle.

§ 5. In considering the action of muscles, the suPPoRT OF THE
Bopy may be first considered. The way in which this is affected
varies of course with the posture it may assume. In standing, the
basis of support afforded by the four paws is very wide, but the
posture cannot be maintained when the muscles are inactive, on
account of the flexibility of the joimts. It is maintained by the
normal contraction (tonicity) of the muscles, which, being placed on
opposite sides of the body and of each supporting limb, antagonize
each other, and so prevent the joimts from flexing, and the body
from censequently drooping, collapsing, and falling to the ground,
as it does immediately when any sudden cause (such as a violent
blow on the animal’s head, or shot sent through its heart) suddenly
suspends their action.

During waking life, changes of posture, which tend to cause the
centre of gravity to fall without the basis of support, are instinctively
followed by compensating motions which have the effect of retaining
it within such basis. Thus if the left fore-leg be extended outwards
to the left, the body instinctively and simultaneously leans, or the
tail is thrown, over to the right, and the extreme mobility of the
tail in all directions is a great agent in maintaining the equilibrium
of the body.

In locomotion the limbs may be used either successively, as in
walking, or simultaneously as in springing and running. In leaping,
all the joints of the hind-limbs are bent, and these by their sudden -
unbending give impetus to the body.

In walking, each leg alternately swings forward as a pendulum,
the fore and hind-limb of each side being advanced successively and
alternately with one of those of the opposite side, as e.g., Ist, left
fore-leg; 2nd, right hind-leg; 3rd, right fore-leg; 4th, left hind-
leg. Even in walking, however, the impetus is imparted by the
hinder limbs, the action of the fore-limbs being mainly that of
support.

The part of the foot applied to the ground by the cat does not
answer to the sole of the human foot, but only to the toes; the
heel being raised much above the ground. Similarly im the fore-
foot the wrist is raised and the digits alone support the body. On
this account the cat’s mode of progression is spoken of as
digitigrade.

As has been already said, the muscles generally act on the bones, -
making use of the latter as LEVERS or FULCRA.

The levers used in the cat’s body are of all the three orders
K

130 THE CAT. |. _ [CHAP. Vv.

known in mechanics. A “lever” consists of a rigid rod, movable
in one plane round a point—the “ fulcrum.” |

The first order of levers is where the fulcrum is placed between
the weight and the motive power.

The second order is where the weight to be moved (or resistance
to be overcome) is placed between the fulerum and the power.

The third order is where the power is applied between the fulerum
and the weight or resistance.

In the action of the hind-legs of a cat which is lying on its back
and scratching at an object with its hind claws, we have an example
of the first order of levers. For thus the muscles of the calf, being
attached to the tuberosity of the os calcis, act on the skeleton of the
foot as on a rod resting against the distal end of the tibia as on a
fulcrum. The other end of this rod (the claw-bearing part) pushes
away any object against which it may strike. |

The same parts, as employed in walking, may serve as an example
of the second class of levers. ‘Thus considered, the earth will be
the fulcrum, the weight to be moved (the body as resting on the
tibia) being placed between it and the point of muscular attachment
—that is where the motive power is applied.

An example of the third order of levers is seen in the action of the
cat in raising the fore-paw to strike or to wash the face orear. Here
the paw is the weight, and the fulcrum isthe distal end of the humerus.
The motive-power being applied in the intermediate space, viz. (as we
shall see) at the attachment of the biceps muscle to the radius.

§ 6. The crassiricaTion of muscles follows naturally that of the
parts of the skeleton. Thus we have—

(a) Muscles of the exo-skeleton, the skin, and
(b) Muscles of the endo-skeleton.

To these it will be convenient to add a third category, namely,—
(c) Muscles of the viscera. |

The exo-skeletal system of muscles may consist of smooth or striped
fibres. Some are large and some very small. :

The endo-skeletal system is naturally divisible, like the endo-
skeleton itself, into parts appertaining to the head, trunk, and tail
(the axial portion), and parts belonging to the limbs (the appen-
dicular portion).

The wiscero-skeletal system of muscles consists of the muscular
fibres placed in the walls of the alimentary canal and in a variety of
tubes or organs (such as the heart, bladder, &c.,) to be hereafter
noticed in describing those parts.

Since, however, the muscles of the first category are few in
number, while those of the third may be better considered in treat-
ing of the viscera they help to form, the best practical course here
will be to consider the muscles according to the regions of the body
to which they belong—the head and neck, the trunk and tail, and
the limbs.

CHAP. V.] THE CAT’S MUSCLES. 131

MUSCLES OF THE HEAD AND BACK.

§ ‘7. The platysma myoides is a skin muscle which covers the
side of the neck and face. Its facial part invests the bulbs of the
vibrissee and long hairs of the eye-brows.

The orbicularis oris is a sphincter muscle, its fibres extending
round the mouth in the sutstance of the lips. The fibres of the
upper and lower lip meeting at a symphysis at each angle of the
mouth. It is very slightly developed, and is much- interrupted
medianly above, because the cat's upper lip is divided medianly
into two lobes.

The orbicularis palpebrarum is a thin muscle, the sphincter of the
eye-lids, as it surrounds the eye beneath the skin. Itis not attached
to any bone except at the imner margin of the orbit, and its fibres
are arranged concentrically so as to close the eyelids by their con-
traction. This muscle adheres intimately to the skin.

The occipito-frontalis is a thin, flat muscle, one portion of which
is attached to the fascia of the occiput and temporal region, the other to
the frontal region, and is connected with the orbicularis palpebrarum.

The levator labi superioris aleque nasi is a rather large flat muscle
which is connected above with the frontal portion of the foregoing, and.
thence descends to the upper lip and angle of the orbicularis oris.

The levator anguli oris (Fig. 77, c) is a small fleshy mass which arises
beneath the infra-orbital foramen and descends to the outer ala of the
nose and upper lip.

The pyramidalis passes downwards from the frontal to the dorsum
of the nose.

Compressor naris.—This 1s a very faintly-marked muscle of fibres
extending transversely over the cartilages of the nose.

The sygomaticus (s) is a small muscle extending downwards from
the malar close to the maxilla (when it is continuous with the zygo-
mato-auricularis) to the orbicularis oris, near the angle of the mouth.

The myrtiformis is a triangular, rather large muscle extending from
the firm tissue enclosed in the upper lip to the side of the nose (my).

The cat’s ears are very movable, and can be strongly drawn back
and folded down close to the head.

A variety of small muscles are inserted into the cartilage of the
external ear, or into a narrow, elongated cartilage called the scuti-
form cartilage, which extends on the surface of the head obliquely
forwards and inwards in front of each ear, and slides over the
_ aponeurosis of the temporal muscle.

The fronto-auricular (fa) 1s a small muscle extending from the
orbit to the ear.

Another is the femporo-auricular (to) which extends (beneath the
front auricularis) from the hinder side of the orbit to the antitragus.*

The mazillo-auricular (mo), slender and vertical, extends from the
mandible behind the condyle to the outer side of the base of the concha.

* For an explanation of the parts of the ear, see Chapter IX., § 26.
K 2

TV ARSWORE MN TS MGC DME vem CPEIC Te CVPR: tie. (camara ret ie Pete To

132 THE CAT.

Various other muscles act on the ear, which it is not deemed
necessary to describe in detail ; suffice it to say they may be grouped
into muscles which tend to draw the external ear forwards, inwards,
or backwards. Certain muscles pass even from the skin to the ear—
the auriculo-cervicalis from the skin of the front of the neck, and the
auriculo-labial and the auriculo-submaxillary from the lips and from
the skin beneath the lower-jaw.

The sygomato-auricularis passes from the skin of the cheek and
from the zygoma backwards to the pinna of the ear externally. It
isin part continuous with the zygomaticus. It draws the ear forwards.

The <Attolentes auriculam are muscular bundles which pass from
the mid-cranial region outwards to the pinna, so as by their con-
traction to bring the two ears together.

The retrahentes auriculam are various muscular (ra) bundles which
come from the occiput and the cervical region to the pinna, and by
their action draw it backwards. )

The eyeball, lying in its orbit, is held in place and moved by
seven muscles.

The first of this is the swspensor oculi, or “choanoid muscle,”
which arises round the optic foramen, and thence expanding and
embracing the eyeball, is inserted into rather the posterior surface ot
the latter. Its fibres are directed longitudinally outwards, and it. is
more or less divisible into four parts—one superior, one inferior, one
external, and one internal.

External to this muscular cone are four straight and two oblique
muscles of the orbit (Fig. 180). )

The four straight muscles, or recti, also arise round the optic
foramen, and thence diverging, are respectively inserted into the
upper, inner, lower, and outer sides of the eyeball, whence they are
termed superior, internus, inferior, and externus, respectively. They
are inserted in front of the insertion of the suspensor oculi, and corre-
spond with and are superimposed on the four portions of the latter.

Each rectus muscle is a flattened band of parallel fibres, and pulls
the eyeball by its contraction either upwards or inwards, or down-
wards or outwards. By combining their actions variously, they
can move it in any intermediate direction.

The obliquus superior is also a long and slender muscle arising near
the optic foramen. At the inner margin of the orbit its tendon passes
through a fibro-cartilaginous ring (or pulley) attached to the frontal
bone, and then bends backwards to be inserted between the upper
and the external recti muscles.

The obliquus inferior has no pulley, and is the only short muscle ok
the orbit. It springs from the orbital plate of the maxilla near the
lachrymal groove, and passing thence backwards, between the floor
of the orbit and the rectus inferior, is inserted into the postero-
external aspect of the eyeball. ;

The two oblique muscles are so disposed as to draw the eyeball
forwards and inwards when they act together, and to rotate it in
different ways when they act successively. The upper oblique

(CHAP, Vv.

CHAP. V. | THE CAT’S MUSCLES. 133

rotates it from without inwards and from below upwards, and the
lower oblique acts in the reverse manner.

We shall hereafter see that different nerves go to certain of these
muscles. The choancid muscle is supplied by the sixth nerve.

The levator palpebre is another long slender muscle arising near
(above) the optic foramen. It is inserted into the upper eyelid,
which it raises. No analogous muscle depresses the lower eyelid.

The duccinator is a thin, delicate muscle extending between the
alveolar margins of the jaws on each side of the mouth (¥ig. 77, B).
Its fibres cross each other near the middle of the muscle, and it is
perforated by the duct of the parotid gland. It adjoins internally the
mucous lining of the mouth ; externally, it is partly covered by the
muscle next described.

The masseter (JL) 1s a short and very thick muscle (in two layers)
which arises from the malar and under surface of the front part of
the zygoma. Its fibres pass thence obliquely backwards (those of
the outer layer, very obliquely), to be inserted into the concave outer
surface of the ascending ramus of the mandible. Externally, this
muscle is only covered by skin and fascia. Its action is to raise the
lower jaw, and is therefore an important agent m mastication.

Each temporatis (1) covers the side of the skull, almost meeting its
_ fellow of the opposite side at the sinciput. Each arises in two layers,

from the side of the skull (from the latubdoidal ridge to the postorbital
process of the frontal) and being thick and fleshy, fills up the tem-
poral fossa (to which it gives its name) within the zygoma. Its fibres
converge (fan-wise) to its insertion into the coronoid process of the
mandible. Its action raises the lower jaw, and thus enables the animal
to take a very firm grip of any struggling prey it may have seized.

The pterygoideus internus is a strong muscle which arises from the
pterygoid fossa. Its fibres descend obliquely forward to its insertion
in the inside of the angular part of the mandible. It is close to the
‘masseter inferiorly, bemg only separated from the latter beneath the
margin of the mandible, by aponeurosis. It acts with the masseter
in raising the lower jaw.

The pterygoideus externus arises from the outside of the pterygoid
and pterygoid plate of the sphenoid, and is inserted into the inside of
the neck of the mandibular condyle, and thence forwards to the
orifice of the dental foramen. In its action it is also an elevator of
the mandible, since though by its direction it tends to draw the
mandible somewhat backwards, it cannot do so owing to the opposi-
tion of the post-glenoid process.

The digastric is a large muscle which arises from the skull behind the
external auditory meatus, ¢.c., from the paroccipital. It is inserted into
the inside of the anterior halt of the inferior margin of the mandible.

The middle portion of the muscle is very aponeurotic internally,
externally, and below. ‘Its action is to depress the lower jaw and
open the mouth (D).

The stylo-hyoid (sty-h) is a longish muscle which descends from the
mastoid process to the side of the hyoglossus.

A Te) Ly Ba eee ee Be toh Se 4
q "* } al & . ae,

134 THE CAT. [CHAP. V.
The sty/o-glossus (sty-g) is very large. It arises from the stylo-hyal
(and the ligament connecting it with the tympano-hyal), and the
stylo-maxillary ligament, and thence passes to the side of the tongue.
The stylo-pharyngeus arises from the stylo-hyal and tympano-
hyal, and passes thence to the side of the pharynx.

The mylo-hyoid is a flat muscle which passes from the inside of
the mandible to the body of the hyoid. It unites with its fellow of
the opposite side (in the middle line, beneath), the two together
forming the muscular floor of the mouth.

The genio-hyoid is narrow, and goes from inside the mandible, near
the symphysis to the basi-hyal.

The gento-hyoglossus is a flat, more or less triangular muscle which
arises from inside the mandibular symphysis, and is inserted in a
radiating manner from beneath the tongue towards its tip back to
the basi-hyal.

The hyoglussus is also a flat muscle passing upwards from each
thyro-hyal to the side of the tongue.

The thyro-hya/ muscle is a flattened longitudinal one which unites
the thyro-hyal with the chain of ossicles intervening between the
tympano-hyal and basi-hyal. |

The sterno-hyoid arises on the deep (or inner) surface of the
sternum, and is inserted into the basi-hyal (St. hy).

The sterno-thyroid, arising close to the last noticed, is inserted into
the thyroid cartilage of the larynx (S?. th).

The thyro-hyoid is, as it were, a continuation of the sterno-
thyroid, and proceeds on each side from the thyroid cartilage of the
larynx to the thyro-hyal (Fig. 45, ty).

These three last muscles all tend, directly or indirectly, to draw
back the hyoid. |

The sterno-mastoid (Fig. 79, St. m) arises from the side of the
manubrium (beneath the anterior part of the pectoralis major), and
passing forwards and upwards is inserted into the side of the skull
just above the mastoid process. If one sterno-mastoid acts alone, it
tends to rotate the muzzle towards the opposite side. If both act
together, they tend to depress the head as a whole, and somewhat
tilt up the muzzle.

The cleido-mastoid arises from the clavicle, and is inserted into the
mastoid process on the ventral side of the insertion of the more
superficially passing sterno-mastoid.

The scalenus secundus lies deeply at the side of the neck. Jt arises
from the transverse processes of the 38rd, 4th, 5th, 6th, and 7th
cervical vertebree, and is inserted into the first rib (Fig. 79, sc’).

The scalenus primus (very much longer) arises mainly by strong
but delicate tendons from the 4th and 5th cervical vertebra, and
is inserted into the 4th, 5th and 6th ribs near the sternum. It
comes as it were out from the substance of the scalenus secundus,
with which it is closely connected (sc').

The action of the scaleni is to pull the ribs upwards and forwards,
and so to help to expand the chest.

: Mi aa
oe i —

CHAP. V.] THE CAT’S MUSCLES. 135—

The scaleni are entirely on the dorsal side of the axillary vessels
and nerves.

The rectus capitis anticus major proceeds from the transverse pro-
cesses of all the cervical vertebre to the basi-occipital.

The rectus capitis anticus minor springs from the atlas, on its
ventral aspect, and goes to the basi-occipital.

The rectus dateralis proceeds from the transverse process of the
atlas to the paroccipital portion of the skull. It is hardly separable
from the obliquus capitis superior described below (Fig. eee

The /ongus colli occupies the ventral aspect of the cervical and
anterior dorsal regions. Its fibres extend between the transverse
processes and bodies of the various vertebree over which it passes,
with the exception of the axis, and terminate anteriorly on the
ventral surface of the atlas. It extends back to the body of the
sixth dorsal vertebra.

The rectus capitis posticus major passes from the neural spine of
the axis to the occiput.

The rectus capitis posticus minor goes from the en arch to the
occiput beneath the muscle last described.

The obiquus capitis superior extends from the transverse process
of the atlas, to the paroccipital region. It is a short muscle.

The obliquus capitis inferior is very large. It arises from the neural
spine of the axis, and is inserted into the transverse process of the atlas.

The muscle named the splenius is a large one arising from the
whole length of the middle line of the neck, and from the anterior
dorsal neural spines. It is inserted into the outer part of the
lambdoidal ridge.

The Complewus i is a very large fleshy mass arising from the sides
of the last five cervical vertebra.

It is inserted into the occipital region beneath the splenius.

Another muscle, called Complexus tertius, consists of a series of
fleshy bundles which extend from the zygapophyses of the posterior
cervical vertebree, to the transverse process of the atlas.

The constrictors of the pharynx are muscles which enclose the
alimentary canal in the region of the throat, and form an elongated
bag of three successive muscular divisions called respectively the
inferior, middle, and supemor. ‘They spring respectively from the
sides of the larynx, the hyoidean cornua, the pterygoid bones, and
the mandible, and meeting in the middle line on the dorsal side cf
the pharynx, are attached at their summit to the basi-occipital.

The soft palate is formed in part by the help of two pairs of smail
muscles; (1) the levator palati descends from the sphenoid, petrous and
tympanic bones. Its fibres radiating, in part meet those of its fellow of
the opposite side, and in part lose themselves i a the side of the throat.
(2.) The cir cumflerus palati arises from the skull externally to the
foramen ovale, and externally to the origin of the levator palati. It
then descends obliquely, and ends in a flattened tendon which
passes inwards round the hamular process of the pterygoid, and
expands within the velum palati.

rar

136 | } | THE CAT.

The muscles of the pharynx and palate effect deglutition. As
soon as any portion of food, or other object, is grasped by the
superior muscle of the pharynx, its fibres and those of the lower
pharyngeal muscles successively contract, so as to drive the sub-.
stance so grasped backwards towards the stomach.

MUSCLES OF THE TRUNK AND TAIL.

§ 8. The muscles of the back are arranged in successive layers.

Fig. 77.—Muscies oF RIGHT SIDE oF FoRE-QUARTER: A RECTANGULAR CUT BEING MADE IN THE
CEPHALO-HUMERAL, TO SHOW MUSCLES BENEATH.

B. Buccinator.

Ba. Brachialis anticus.
C. Levator anguli oris.
Ch. Cephalo-humeral.
Cm. Cleido-mastoid.

D' and D2. Two parts of deltoid.

D. (Of head) digastric.

Ed. External dorso-epitrochlear.

Eo. External oblique.

Fa. Fronto-auricular.

La. Levator anguli scapule,
Id. Latissimus dorsi.

Us, Levator scapule.

M. Masseter.

Mo. Maxillo-auricular.

My. Myrtiformis.

Oo. Orbicularis oris.

Op. Orbicularis palpebrarum.

P4, Pectoralis.

Py, Pyramidalis.

Ra. Retrahentes auriculam.

Rc. Rhomboideus capitis.

Rm. Rhomboideus major.

Smg. Serratus magnus.

T. (Of head) temporal.

T! and T?. Anterior and posterior parts of tra-
pezius.

Tr!, Tr2, Parts of triceps.

To, Temporo-auricular.

Z. Lygomaticus.

Sct. Seutiform cartilage

Sty. g. Stylo-glossus.

Sty. h. Stylo-hyoid.

St. hy. Sterno-hyoid.

St. th. Sterno-thyroid.

Some of them help to retain the shoulder and pelvic girdles (and
therefore also the limbs) in place.

The most superficial dorsal muscle is a cutaneous muscle—or one
intimately connected with the skin. It is called the Panniculus
carnosus, and is one of the largest muscles of the body. It forms a

CHAP. V.] THE CATS MUSCLES. 137

fleshy sheet, which envelopes the anterior part of the back and the
chest—being continued on into the neck and head as the platysma
myoides already noticed. At its margin the panniculus ends in an
aponeurosis, which connects it with parts adjacent. The muscular
fibres converge to the axilla, being directed forwards and outwards
to it on the chest, and forwards and downwards to it on the side of
the back. It is inserted into the deeper fascia of the upper arm,
passing in part on the inner side of the biceps muscle, and in part
continuing on down to the wrist.

The muscle by its contraction effects those twitching movements
of which the cat’s skin is capable.

Next, beneath this cutaneous muscle is the trapezius, of which

_ there are two parts, closely connected inferiorly, but dorsally, by a

delicate fascia only.

A. The hinder portion arises from the neural spines of the dorsal
vertebree—from the second to the twelfth. It is mserted by
strong fascia mto the membrane which invests the external
scapular muscles, the line of insertion passing obliquely across
the spme of the scapula at a point situated about one-third of
the length measured from its vertebral margin downwards, and
dipping slightly beneath the insertion of the anterior part of
the muscle (Z'*).

_ B. The anterior part arises from the fascia in the middle of the
neck as far forwards as the hinder end of the origin of the
cephalo-humeral, with which it is connected. Its origin
extends backwards till within about half an mch of the origin
of the posterior part. It is inserted into the spine of the
scapula, from the metacromion process upwards to the point of
insertion into the scapular spine of the hinder portion of the
trapezius, into the scapular spine, which insertion it slightly
overlaps (7).

The /atissimus dorsi 1s am exceedingly large sheet of muscle which
takes origin from the neural spines of the vertebra, from fifth dorsal
to the fourth lumbar—its origia from the lumbar vertebre being by
fascia only. It is overlapped for almost the anterior half of its
origin by the posterior part of the trapezius (Ld).

Its fibres converge to a tendon which, after blending with that of
the teres major, is inserted into the inner side of the shaft of the
humerus below the lesser tuberosity. Virtually at its anterior end
it blends with adjacent fibres of the fourth part of the pectoralis,
and is then inserted into fascia in the neighbourhood of the
axilla. Before its insertion it gives off a muscle—the inner dorso-
epitrochlear—which descends, and blending with the smaller external
dorso-epitroch!ear is inserted into fascia on the inner side of the
olecranon. Its action is to pull the arm backwards, or, if the arm
be fixed, to bring the body forwards. It thus gives much aid in
climbing (Fig. 81, ide).

The external dorso-epitrochlear.— This is a slender muscle
(Fig. 77, ed), which takes origin from fascia outside the spine of the

138 THE CAT.

scapula, between the hindermost and uppermost part of the deltoid,
and the posterior end of the insertion of the trapezius. Blending
with the internal dorso-epitrochlear, it is inserted as above stated.

The serratus posticus anterior arises by fascia from the mid-
line of the back, and is inserted by very thin and faintly marked
muscular digitations, into the outer surfaces of the ribs, from the
second to the twelfth—the digitations inclining downwards and
very much backwards. Posteriorly it is over-lapped by the next
muscle to be noticed. :

The serratus posticus posterior arises from the fascia of the middle
of the back, and is inserted by six digitations into the outside of the
eighth, ninth, tenth, eleventh, and twelfth ribs. The digitations
are inclined downwards and very slightly forwards. Anteriorly it
overlaps the hinder part of the serratus posticus anterior. |

A membrane called the ‘“ vertebral aponeurosis,” is continuous
with the serratus posticus posterior, and passing forwards between
the muscles of the shoulder and those of the trunk, it also binds
down the great muscle to be next described.

Erector spine.—Under this title is included a very large and
complex muscular mass occupying the groove which exists on each
side of the dorsum of the skeleton, between the neural spines and
the ribs at the point where the latter are much arched upwards.
It is divided into two parts, one being nearer to, the other farther
from the neural spines. Each of these two parts extends forwards
towards the neck from the common origin of both in the sacral
region.

“Sacro-lumbalis.—This’ name designates that part of the erector
spinze which is the more externally placed, and is attached to the
ribs. It is a very thick muscle at its origin from the ium and
sacrum close to their line of junction. It is inserted into the
lumbar transverse processes on their dorsal aspect and, by tendons,
into all the ribs at their angles—the tendons becoming longer as the
muscle advances forwards. The last portion, that inserted into the
transverse process of the seventh cervical vertebra, is the represen-
tative of a muscle called the cervicalis ascendens.

Longissimus dorsi is the term applied to the inner part of the
erector spine. It is much smaller posteriorly than the last described,
but extends further forwards. It arises from the anterior margin of
the ilium, and the fascia investing the erector spine dorsally, and
is inserted into the dorsal surface of the lumbar transverse pro-
cesses, the metapophyses and the ribs on the dorsal side of their —
angles.

The transversalis cervicis is the continuation of the last described
muscle into the neck, where it is invested by firm, strong tendons into
the transverse processes of the five last cervical vertebrae.

The spinalis dorsi is really but an inner portion of the longissimus
dorsi, and goes from the neural spines of the more posterior to those
of the more anterior dorsal vertebra. As continued on to the spine
of the axis, it is called the spinalis colli.

CHAP. V.] THE CATS MUSCLES. 139

Other minor divisions of the erector spine bear the names semi-
spinalis, multifidus spine, rotatores spine, inter-spinales, and inter-
transversales, and have their fibres directed as follows: at first, from
the transverse processes to the neural spines; the second, from
metapophyses (or the parts which serially correspond with the met-

Fig. 78
mi. Dm
; A.—INTERNAL ASPECT OF STERNUM AND CosTAL CARTILAGES—MUSCLES OF LEFT SIDE BEING
ALMOST ALL REMOVED.

No. 1 to 13. The ribs. ts. Triangularis sterni. i

V, VI. The fifth and sixth sternebre. xz. Xiphoid cartilage. t
d. Diaphragm. The small figure below represents on one side
e. Internal intercostals. the sternal ends of the cartilages of the eighth
4. External intercostals. and ninth ribs, and on the other side the
io. Internal oblique. sockets (f) for the cartilages of the eighth
sm. Sterno-mastoid. and ninth of the other side.

s®. Sealenus secundus.
B.—ARTICULATIONS OF CERTAIN COSTAL CARTILAGES AND STERNUM.

apophyses,) to neural lamine in front of them; the third, from the
transverse processes to, the neural lamine next in front of them;
the fourth, from neural spine to neural spine, and the fifth and last,
from one transverse process to another.

If these various muscles of both sides of the body act, they flex
the spine vertically—as when the animal bounds along. If those of

Lit

140 THE CAT. oHAP. V.

one side act alone, the whole backbone is flexed towards the side of
such action. :

The /evatores costarum are small groups of fibres passing obliquely
backwards from the dorsal transverse processes to the respective ribs
at their proximal parts.

Layers of fibres extending obliquely from rib to rib are called
‘intercostal muscles,’ and there are two sets of them, one inner,
the other outer (Fig. 78).

The external intercostals are more dorsally situated, since each

Il in y_ Shy

Fig. 79.—MoscLes oF VENTRAL SURFACE OF TRUNK—THE LEFT FORE-LIMB AND LEFT PECTORAL
MUSCLES BEING REMOVED.

CM. Cleido-mastoid. R. Rectus abdominis,
Cv. Clavicle. Scl. Scalenus primus.
D3, Deltoid. Sc?. Scalenus secundus.
Ed. External dorso-epitrochlear. Shy. Sterno-hyoid.
Exo. External oblique. Sm. Serratus magnus.
Id. Internal dorso-epitrochlear. S@. Sternalis.

Io. Internal oblique. Sé. Second sternalis.
Id. Latissimus dorsi. St. m. Sterno-mastoid.

P}, P?, and P, Pectoralis.

such intercostal connects two ribs, all the way from their tubercles
to their cartilages. Their fibres are directed backwards and down-
wards (#).

The internal intercostals have their fibres directed backwards and
upwards, and the sheet of such fibres which connects each pair of
ribs reaches from the sternum upwards as far as the angles of the

CHAP. V. ] THE CATS MUSCLES. “141

ribs. The intercostal nerves and vessels are interposed between the
two sets of intercostal muscles (e).

The triangularis sternt is the name given to a layer of muscle
which diverges forwards to the cartilages of the mbs from the deep
(inner) surface of the sternum (Fig. 78, ¢s).

The diaphragm is (as has been before mentioned) a very impor-
tant partly fibrous, partly muscular structure, which separates the
thoracic and abdominal cavities. It forms a partition convex
forwards and concave backwards, and is attached to the xiphoid
cartilage, to several ribs, to the centra of the lumbar vertebre, and
to the aponeurosis, which invests the quadratus lumborum and
psoas muscles.* At its circumference the diaphragm is muscular;
its central portion is tendinous. It is perforated for the passage of
certain organs—namely, for the cesophagus and for two great blood-
vessels called aorta and inferior vena cava.

The muscles just enumerated aid the process of respiration as
follows :—

Apart from the elasticity of the substance of the lungs, respiration
is effected by the successive enlargement and contraction of the
thoracic cavity. We have seen that the ribs are movably articu-
lated to the vertebral column. They can be drawn forwards (and
the cavity of the thorax can be in consequence enlarged) by the
external intercostals and levatores costarum, but the main agent in
this process is the contraction of the muscular fibres of the diaphragm
resulting in a diminution of its convexity. Air rushes in to fill the
thus enlarging cavity, and we thus have Inspiration. Expiration is
effected by the drawing backwards of the ribs by the internal inter-
costals and by the relaxation of the contraction of the fibres of the
diaphragm, which in consequence resumes its more convex shape,
and so contracts the thoracic cavity, a process further aided by the
contraction of the muscles of the belly, the external and internal
oblique, the rectus and transversalis.

The abdominal region of the body is invested by three great sheets

-of muscle and membrane, which enclose and support the abdominal

viscera—and tend by their contraction to expel the contents of such
viscera and, as just said, indirectly to aid in respiration.

The first of these muscles, the eaternal oblique, arises by eight
digitations from the eight hindmest ribs and from the lumbar fascia.
Its fibres pass obliquely downwards, backwards and inwards (towards
the mid-ventral line,) to be inserted by muscle and membrane into
the brim of the pelvis—part of the membrane (or aponeurosis,)
divides into the “external” and “internal” tendons. Between
these tendons (of which the internal is the stronger,) an aperture is
left called the “ external abdominal ring,” (through which certain
structures pass,) bounded in front by what is called Poupart’s
ligament. | 3

This so-called ‘‘ligament” is really but a band of delicate fascia,

* These are described amongst the muscles of the hind limb.

142 | THE OAT. [CHAP. Y.

which extends from the pubic symphysis to the anterior part of the
ventral margin of the ilum.

In front of the pelvis the muscle ends in aponeurosis, which meets
that of its fellow of the opposite side in the mid-ventral common
fascia, which extends forwards to about the fourth rib. It passes
superficially to the rectus muscle, but its fascia is closely adherent to
the surface of the rectus.

The deeper abdominal muscle, the internal oblique, is another sheet
partly muscular, partly membranous, but its fibres are directed
downwards, forwards and inwards. It arises from the lumbar fascia—
on the outer side of the erector spinee—from the entire ventral margin
of the ilium and from the pubis. At its origin it leaves three aper-
tures at the brim of the pelvis. Through the uppermost of these the
psoas muscle passes out to the thigh. The next below is traversed by
the great vessels, and through the lowest the spermatic cord makes its
exit in the male. It is inserted inside the cartilages of the ribs, and,
behind the thorax, joins with its fellow of the opposite side—its fascia
passing on the ventral side of the rectus to about the middle of the
abdomen, in front of which point it passes above the rectus.

The deepest of the abdominal muscles, the transversalis, arises
from the cartilages of the ribs behind the diaphragm, from the
ventral margin of the ilium and from the fascia which invests the
under side of the erector spine. It is therefore separated at its
origin by a wide interval from the origin of the internal oblique ;
the interval being occupied by the erector spine and by fat. ‘The
muscular fibres of the transversalis extend vertically downwards
(.e., transversely to the long axis of the body,) to the margin of the
rectus, within which its fascia extends—i.e., on the dorsal surface of
the rectus. The abdominal nerves extend round the body between
this muscle and the internal oblique. |

Rectus abdominis.—This is a long muscle which, arising from the
symphysis pubis, runs forwards m contact with its fellow of the
opposite side, to be inserted into the third rib, and thence on, by
aponeurosis, to the second and first ribs. It is enclosed ventrally
by the aponeuroses of the external and internal oblique from its
origin to the middle of the abdomen. Thence forwards it is enclosed
below by the aponeurosis of the external oblique, while above, it
' is invested by the aponeuroses of the iternai oblique and trans-
versalis (ig. 79, £). |

The rectus is separated from its fellow of the opposite side by
a narrow interval, which is occupied by a tendinous cord—the linea
alba.

The fibres of the rectus are interrupted at intervals by very faintly
marked transverse tendinous intersections.

Sternalis.—This small muscle (S/") arises from the anterior end
of the rectus abdominis close to the sternum, at the third and fourth
costal cartilages. It passes forwards and outwards, and is inserted
into the first rib just ventrally to the insertion of the scalenus primus.
A small second sternalis (St?) extends from the outer border of

7 * el ai

CHAP. V.] THE CAT’S MUSCLES. 143

the rectus, and passes outwards to be inserted between the fifth and
the sixth hindmost digitations of the serratus magnus, just behind
_ the hinder end of the scalenus primus.

External to the abdominal muscles the trunk is invested by an
aponeurosis called the superficial fascia. At its posterior part this
fascia is separable into two layers, the deeper of which adheres to
Poupart’s ligament, while the more superficial is (in the male)
prolonged into the scrotum—surrounding the structures which pass
from out the abdominal ring into that receptacle.

Internal to the abdominal muscles, the abdomen is lined by a
membrane called the fascia transversalis. It is pierced near its hinder
margin by an opening called the internal abdominal ring, through
which the spermatic cord passes in the male.

Levator caude externus.—This is the continuation backwards of
the longissimus dorsi, and arises from the lumbar and sacral trans-
verse processes, and is inserted by a succession of long, delicate
tendons into the metapophysial parts of the caudal vertebrae suc-
cessively. This and the following muscle bend the tail upwards.

The levator caude internus.—This is the continuation backwards
of the semi-spinalis, and is a yet more medianly-placed dorsal muscle.
It is formed of a number of delicate, fleshy bellies and tendons,
which connect the dorsal and lateral regions of successive caudal
vertebre. :

_ The pubo-coccygeus is a thin, flat muscle which arises from inside
the pubis and goes to the ventral aspect of the third, fourth, and
fifth caudal vertebre.

The ilio-coccygeus passes from the inner side of the ilium to the
ventral surfaces of the fourth, fifth, sixth, and seventh caudal
vertebree.

The sacro-coccygeus arises (on each side) from the lateral part of
the ventral surface of the sacrum, and from the sides of the ventral
surface of the first eleven caudal vertebre. It sends its tendons
forth back along the ventral surface and side of the tail to its
extremity.

The infra-coccygeus is situated in the mid-ventral line of the tail,
thus connecting together its successive vertebre.

The above four muscles bend the tail downwards.

The ischio-coccygeus is large and thick. It springs from the spine |
and internal surface of the ischium, and is inserted into the whole
length of the transverse processes of the first four caudal vertebre.

Inter-transversarti caude are small shps connecting laterally the
successive caudal vertebre. It takes origin from the transverse
processes of the last sacral vertebra.

This and the preceding muscle flex the tail laterally.

The following muscles are found in the vicinity of the root of the
tail, and are some of them connected therewith :—

Levator scroti.—This is a cutaneous muscle which arises in the
dorsum of the tail at about the fifth caudal vertebra, and becoming
connected with the sphincter ani externus expands upon the scrotum

144 THE CAT.

(or upon the parts analogous in the female) as a delicate layer of
cutaneous muscular fibres.

The ischio-cavernosus is a small muscle arising from inside of the

ischium a little below its tuberosity and ending in a tendinous
expansion applied to a part hereafter to be described as the corpus
cavernosum (Fig. 115).

The caudo-cavernosus is a slender muscle which passes backwards —

from the under-surface of the root of the tail to the corpus caver-
nosum between Cowper’s glands.

Transversus perencei.—This is a small but very distinct muscle
which arises from the inner side of the ischium below its tuberosity.
It joins its fellow of the opposite side in front of the anal aperture,
being more or less united with the sphincter ani internus. |

The compressor urethre is a muscle which springs from the inner
side of the pubis, and divides into two portions, one passing above
and in front of, and the other below and behind, the urethra.
These portions end by meeting with corresponding divisions of the
muscle of the opposite side of the pelvis. It is very large im the
male, extending between the prostate and Cowper’s glands.

The ano-coccygeus arises (in the middle line) from beneath the
second and third caudal vertebree, and passes downwards and back-
wards, expanding as it goes, to the upper part of the rectum.

The recto-coccygeus arises from the upper lateral part of the
rectum. It ascends, and, joining with its fellow of the opposite side,

passes upwards and backwards between the two ano-ccccygeus —

muscles to the under surfaces of the sixth and seventh caudal
vertebrae. It is covered laterally by ilio-coceygeus and pubo-
coccygeus.

The sphincter ani externus surrounds the root of the tail, the
anus, the anal pouches, and the external generative organs. It arises
from the dorsum of the tail at about the fifth caudal vertebra. The
anal pouches are two rounded sacs, each about as big as a pea, placed
one on each side of the rectum close to the anus.

The sphincter ani internus is a mass of fibres arranged circularly
around the anus in front of the sphincter externus and more or less
united with it, especially with the fibres which constrict the anal
pouches.

Thus just as the anterior end of the alimentary tube is surrounded
by a sphincter muscle—the orbicularis oris—so is its posterior
termination also surrounded by an analogous muscular constriction—
the sphincter ani.

This muscle is a more complete sphincter than its anterior
analogue, since it 1s not (as that is) interrupted by any median
notch. Itis connected beneath with the transversus perenei muscles
at their median junction. Above, it is connected by a tendon with
the caudal vertebre at the root of the tail.

A retractor penis muscle passes from the ventral aspect of the
hinder end of the rectum, to the ventral surface of the penis towards
its distal end. |

[emir ae

CHAP, V.] THE CAT'S MUSCLES. 146

MUSCLES OF THE LIMBS.
THE FORE-LIMRB.

§ 9. Serratus magnus.—This is a large sheet of muscle which
arises by ten digitations (the anterior four being wider than the
others) from the sternal aspect of the first ten ribs. It is inserted -
into the vertebral margin of the scapula. The staleni muscles dip
in between the second and third, and between the fourth and fifth
digitations of this muscle.

The levator anguli scapule is a second sheet of muscle similar to
the preceding, and so closely connected with it that they can only
be separated artificially. It is inserted into the scapula with the
serratus magnus. It arises from the transverse processes of the last
five cervical vertebra. The combined insertion of this and the
serratus extends along the whole vertebral margin of the scapula
posteriorly from a point just in front of the insertion of the rhom-
boideus capitis.

The combined action of these two muscles is to suspend the body
as in a hammock from the summits of the two fore-limbs. It aids
also in any pushing action of the fore-limbs, and therefore in
springing.

The cleido-mastoid has been already described.*

The rhomboideus major is a sheet of muscle which takes origin
(beneath the trapezius) from the neural spines of the six hinder
cervical and the four or five most anterior dorsal vertebra. It is
inserted into the vertebral margin of the scapuia; its insertion
extending forwards about half an inch in front of the vertebral end
of the spine of the scapula.

The rhomboideus capitis is a long, narrow muscle which arises
from the lambdoidal ridge, and is inserted into the vertebral margin
of the scapula, just in front of the insertion of the rhomboideus
major, dipping in between the insertion of the last-named and that
of the serratus magnus.

Pectoralis.—This is a very large muscle which consists of five
portions, all going from the sternum and sternal ends of the costal
cartilages to the upper arm. No part goes to the coracoid.

(1.) The most superficial part (Fig. 79, p") is a long, rather narrow,
band of parallel fibres which arises from beneath the manu-
brium and attachment of the first two costal cartilages. It is
inserted partly into the fascia of the flexor surface of the fore-
arm, but partly joins the cephalo-humeral.and is inserted
with it.

(2.) The second and largest part (p*) arises from the manu-
brium and sternum as far back as the fourth costal cartilage.
It also arises from fascia just in front of the manubrium. It
is inserted into the outer side of the deltoid ridge of the

* See ante, p. 134.

‘T.-L

Fig. 80.—Dorsau (EXTENSOR) MuscLES OF
FORE-LIMB.

Amd. Abductor minimi digiti.

An. Anconeus.

B. Biceps.

Ba. Brachialis anticus.

D!' and D?. Deltoid.

Ecd, Extensor communis digitorum.

£ c}. Extensor carpi radialis longior.

E ¢. Extensor carpi radialis brevior.

Li. Extensor indicis.

Emd, Em d, and £ m d3,
digiti.

Eo. Extensor ossis metacarpi pollicis.

Few. Flexor carpi wlnaris.

F p d?. Flexor profundus digitorum,

Is. Infra-spinatus,

P?, Pectoralis.

Sl. Supinator longus.

S sp. Supra-spinatus.

T ma. Teres major.

T mi. Teres minor.

Tr), 2, and 4, Triceps

Extensor minimi

Fig. 81.—VENTRAL (FLEXOR) MUSCLES OF
FORE-LIMB.

B. Biceps.

Ba. Brachialis anticus.

C b. Coraco-brachialis.

Ch. Cephalo-humeral.

E cl. Extensor carpi radialis longior.

E c?, Extensor carpi radialis brevior.

# p d. Flexor profundus digitorum.

Fr, Flexor varpi radialis.

F s. d' and 2. Flexor sublimis digitorum.

Fw and 2. Flexor carpi ulnaris.

Id. Internal dorso-epitrochlear.

Ld. Latissimus dorsi.

P3 and P*. Pectoralis.

Pl. Palmaris longus. ~

Tp. Tension of palmaris longus, cut short to
show the subjacent flexor tendons.

Pt. Pronator teres.

Ss. Sub-scapularis.

S sp. Supra-spinatus.

T ma. Teres major.

Tr’, Triceps.

CHAP. V.] THE CATS MUSCLES. 147

humerus, and extends down (between the biceps and brachialis
anticus to the summit of the lowest third of the humerus. It
is imperfectly divisible into two layers. The more superficial of
these (p? A) arises from the more anterior part of the sternum,
and goes to the lower part of the insertion, while the other part
(p* B) beth arises and is inserted for the whole length of the
origin and insertion of the second part.

(3.) The third part (p*) arises from the sternum between the
second and sixth costal cartilages. It is inserted into the head
of the humerus between the tuberosities by strong fascia closely
connected with that of the supra-spinatus muscle. It is also
inserted by muscular fibres for a short distance into the front
of the humerus just below the great tuberosity.

(4.) The fourth part is the most posterior in origin. It is long
and narrow, and its fibres run more antero-posteriorly than do
the others. It arises from the sternum between the fifth costal
cartilage and the root of the xiphoid. Towards its insertion it
blends with the ventral part of the latissimus dorsi, and some
of its fibres are inserted into the fascia in the neighbourhood
of the axilla. Its main insertion is (by strong fascia) into the
inner side of the deltoid ridge of the humerus below, and on
the inner side of the insertion of the third part.

(5.) The fifth, and much the smallest part, 1s the most an-
terior (p°). It arises from the side of the manubrium, covered
by, and more or less blended with, the second part of the
pectoralis. It passes outwards, becoming slightly connected
with the clavicle, and is inserted into the humerus just above
the insertion of the second part. It may be called the sub-
clavicualr part of the pectoralis.

This muscle adducts the humerus, and enables the cat to give a
powerful blow with the paw inwards. If the arm be fixed, it then
tends to draw the body forwards or, in climbing, upwards.

The cephalo-humeral is a large muscle which arises conterminously,
and more or less blended with the anterior part of the trapezius.
Tits main part takes origin from the back of the skull and the lamb-
doidal ridge, and from fascia in the middle of the neck (Fig. 77, Ch).

It passes down outside the clavicle (with which it contracts a
slight adhesion) and outside the biceps—covering the front of the
upper arm. Near the elbow-joint it fuses with the brachialis
anticus (passing to the outer side and front of the biceps), and is
inserted into the coronoid process of the ulna, having first received
an addition from the first part of the pectoralis. ~

The third part of the deltoid fuses anteriorly with the cephalo-
humeral.

The deltoid consists of three portions :—(Fig. 80, D*) a part which
arises from the scapula between, and from, the acromion and met-
acromion processes ; and (D') a part which arises from the hinder side
of the scapular spine, conterminous with the insertion of the anterior

part of the trapezius.
L 2

se ee A eC, = nee oe

148 Ao THES CAR. CT

These two parts have a common insertion into the lower third of

the flat deltoidal surface on the outer side of the humerus—external —

to the bicipital groove.

The third part arises from the hinder side of the clavicle and —

fuses with the adjacent part of the cephalo- humeral.

The levator clavicule is a muscle which takes origin from the
transverse process of the atlas. :

It is inserted into the end of the metacromion (between the first
and second parts of the deltoid), being overlapped by the cephalo-
humeral and, quite anteriorly, by the sterno-mastoid.

The supra-spinatus forms a very large muscular mass, which
projects much beyond the anterior margin of the scapula. It
arises from, and occupies the supra-spinous fossa of the scapula, with
anterior side of the spme and acromion. It is inserted into the
upper margin of the great tuberosity.

The tnfra-spinatus occupies the infra-spinous fossa of the scapula

(arising from its whole surface, mcluding the hinder side of the —

scapular spine, acromion and metacromion), and is inserted into the
concavity on the posterior part of the outer side of the great
tuberosity.

The teres minor arises from the lower half of the axillary margin
of the scapula, and is inserted into the hinder margin of the great
tuberosity, below the insertion of the infra-spinatus.

The ¢eves major is a much larger muscle which takes origin from
the posterior angle of the scapula and the upper third of its axillary

margin. It is inserted below the lesser tuberosity by a strong —

tendon common to it and to the latissimus dorsi.

The subscapularis occupies the whole inner surface of the scapula.
Its fibres converge from this extensor origin and are inserted into
the lesser tuberosity and capsular ligament of the head of the
humerus.

The supra-spinatus, infra-spinatus and teres minor rotate the limb
outwards, or tend to draw it forwards and raise it.

The subscapularis and teres major rotate the limb mwards, and
tend to draw it backwards.

The coraco-brachialis 1s a very short muscle which arises by a
delicate tendon from the coracoid process of the scapula, and is
inserted into the inner side of the humerus just below the insertion
of the subscapularis (and mainly above that of the teres major,)
between the biceps and the fourth head of the triceps (Fig. 81, Cd).

The biceps arises by a tendon which takes origin from the upper
margin of the glenoid cavity of the scapula. Passing down it ts
inserted by a tendon into the tubercle of the radius (B). }

The brachialis anticus is a muscle placed on the outer side of the
front aspect of the humerus, taking origin from the surface of that bone
as high up as just below the insertion of the teres minor (Fig. 80, Ba).

It passes down between the second part of the pectoralis major,
the triceps and the supinator longus, and is inserted into the coronoid
process of the ulna, and into the ulna on the inner side of that

SS Ss

“CHAP. v.] THE CATS MUSCLES. 149

process. At its upper part this muscle is closely connected with the
tendon of insertion of the deltoid.

The coraco-brachialis draws the arm a little forwards and upwards,
the biceps and brachialis anticus flex the elbow-joimt, which is
extended by the following muscle.

The ¢riceps.—This is an enormous muscle, consisting of five parts.

(1.) The first part (Fig. 80, 7r!), takes origin from the summit of
the outer, posterior part of the humerus, within the tendon of
insertion of the teres minor. Passing downwards, it blends
with the second part a little above the elbow.

(2.) The second and largest part arises by a strong, broad tendon
from the lower half of the axillary border of the scapula,
between the subscapularis and teres minor ; after receiving the
accession of the first part it is mserted by a strong tendon into
the end of the olecranon.

(3.) The third part takes origin from the upper part of the inner
side of the shaft of the humerus, mainly below, but partly
overlapped by, the tendon common to the teres major and latissi-
mus dorsi. Passing downwards it soon blends with the fourth
part.

(4.) The fourth part takes origin from the whole upper surface of
the humerus just below its head,—from the origin of the first
part of the triceps externally, to the insertion of the coraco-
brachialis internally. Passing downwards it receives the
accession of the third part and is inserted into the olecranon.

(5.) The fifth and much smallest part arises from just above the
internal condyloid foramen, and from the bridge of bone
bounding that foramen, down to the internal condyle. Passing
obliquely backwards (Fig. 81, ¢°) it is inserted into the imner
margin of the olecranon. ©

The anconeus is much larger than the fifth head of the triceps.
It arises from a triangular surface {with the apex upwards,) on the
lower half of the shaft of the humerus (especially towards the outer
side of that bone,) its origin extending to the margins of the
olecranal fossa and right down to the external condyle. The
muscle lies between the first and third parts of the triceps, and is
mserted into the whole of the fossa on the outside of the olecranon.

The muscles of the fore-arm consist of pronators and supinators,
flexors and extensors, and their names sufficiently indicate their actions.

The pronator teres arises from the inner condyle and passes down
obliquely to its insertion into about the middle third of the front of
the radius.

The flexor carpi radialis is long and narrow. It arises from the
internal condyle of the humerus in common with the head of the
flexor profundus, and is inserted into the proximal end of the
palmar surface of the second metacarpal. |

The palmaris longus arises from the internal condyle, and passing
down becomes tendinous at the wrist, and ends in an aponeurotic
expansion (called the palmar fascia), which exhibits tendinous

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150 THE OAD: Wx [cHar, %

thickenings, and finally invests the bases of the digits. Near the
wrist it gives origin to the ulnar part of the flexor sublimis.

Flexor sublimis digitorum or perforatus.—This muscle consists of
two distinct parts, each of which is inseparably connected with another
muscle.

The ulnar part of the flexor sublimis arises from the ulnar side
of the palmaris longus close to the wrist. It ends in two tendons,
which go to the fourth and fifth digits respectively (Fig. 81, Fsd'),

Its radial part arises from the surface of the ulnar part of the
flexor profundus—from the upper part of its tendon. It divides
into two small fleshy portions, the larger of which. gives origin to
two delicate tendons which go to the index and third digits (Msa?).

All these four tendons go to the second phalanx of their respec-
tive digits, each splitting (before its insertion) to allow a tendon of |
the deep flexor (next to be described) to pass through, whence this
flexor receives its second above-given denomination.

The second portion of the radial part of the muscle ends in a very
delicate tendon, which goes to the ulnar side of the pollex.

The flexor profundus digitorum or flecor perforans.—This is a very

complex muscle, which arises by five heads.

(1.) The first of these arises from the internal condyle of the
humerus, in common with the third head and with the humeral
head of the flexor ulnaris. Passing down it ends in a tendon
which gives off superficially the radial part of the flexor snblimis,
while on its deep surface it receives the insertion of the mus-
cular fibres of the second part. Its tendon fuses with the main
tendon at the wrist. ,

(2.) The second part, which is large and fleshy, arises from the
outer surface of the ulna—from near the wrist nearly to the
end of the olecranon, and passing up at the olecranon inside both
the flexor carpi ulnaris and the fifth part of the triceps. It 1s
inserted into the deep surface of the tendons of the first part
of the flexor profundus.

(3) The third part arises from the internal condyle, in common
with the first part, and is also connected with the fourth part
some little distance below its origm. It ends in a rather
delicate tendon, which joins the main tendon at the wrist.

(4.) The fourth part arises from the internal condyle, in common
with the flexor carpi radialis. It becomes connected with the
third part, and further down, ends in a rather strong tendon
which joins the main tendon at the same time as does that of
the third part.

(5.) The fifth part arises from the flexor surface of the radius
between the supinator brevis and pronator quadratus, and is
inserted into the common tendon (Fig. 81, Epd°).

The common tendon divides into five small tendons, which go to
the distal phalanges of the five digits. Each of these tendons, except
that to the pollex, passes through the split before mentioned as
existing in each corresponding tendon of the flexor sublimis. It

|

_ CHAP. V.] THE CATS MUSCLES. | 151

is on this account that the flexor profundus is also called the
“ nerforans.”

The dumbricales are small, worm-like muscles (whence their name),
which arise from the palmar surface of the deep flexor tendons of
the four outer digits, and are inserted into the sheaths of the
extensor tendons on the dorsal aspect of the digits as follows :—

One arises from the radial side of the tendon going to the index
and is inserted into the radial side of the index. Another springs
from the palmar surface of the tendon of the medius, and goes to the
radial side of the medius; the third springs from the palmar surface
of the tendons of the third and fourth digits, and goes to the radial
side of the fourth digit. The fourth and last arises from the radial
side of the tendon going to the fifth digit, and is implanted also into
the radial side of the fifth digit.

The flexor carpi ulnaris arises by two heads (separated by the
ulnar nerve), one from the inner condyle of the humerus, the other
from the inner side of the olecranon, almost to its very extremity,
so that it dips in under cover of the fifth part of the triceps. The
humeral belly of this muscle is intimately connected with that head
of the flexor profundus which gives origin to a part of the flexor
sublimis. ‘The two heads continue separate a considerable distance,
and then unite and are inserted into the pisiforme and the fifth
metacarpal.

Pronator quadratus.—The fibres of this muscle extend obliquely
downwards from the ulna to the radius, on the deep flexor surfaces
of those bones for rather less than the lower half of each.

Supinator longus.—This is a long and very slender muscle, which
arises high up, very much above the external condyle, from the
outer surface of the brachialis anticus, and from the middle third of
the outer surface of the humerus. It is inserted into the outer side
of the distal part of the radius (Fig. 81, S7).

The extensor carpi radialis longior is also a long narrow muscle,
which arises from the supinator ridge below the origin of the muscle
last described, and is inserted into the dorsum of the second meta-

-earpal.

The extensor carpi radialis brevior arises close beside and closely
connected with the last. Also long and narrow, it ends in a tendon,
which is implanted into the dorsum of the third metacarpal.

Fixtensor communis digitorum.—This muscle takes origin from the
external condyle of the humerus, and is more or less divisible into
two parts. One part sends tendons to the second and third (or
second, third, and fourth) digits, and the other to the fourth and
fifth digits. Its tendons are inserted into the second and third
phalanges of each of the four ulnar digits.

The extensor minimi digiti is of about the same size as the last
described muscle, arising in common with it and running down
beside it. It soon divides into three parts, whereof the first and
second are much more closely united together than they are to the
third part. The first two parts arise in front of and somewhat

152 pe EE OAM. [oar v0 ee

within the third part, and at about the middle of the arm divide
into two tendons. The more radial of these goes to the fourth digit,
and the more external (the paw bemg prone) to the third digit. »
The third part arises highest up and superficially to the other parts.
It ends in a tendon which runs deeply and (passing at the wrist
through a separate synovial sheath) goes to the fifth digit (Fig. 80).

The extensor indicis el extensor secundi internodi pollicis is a
very long and slender muscle, which springs from the outer margin
of the ulna, for almost its whole length, and from the outside of the
olecranon, bemg there covered in by the anconeus. It ends in two
delicate tendons, which go to the pollex and index digits respectively.

The extensor ossis metacarpi pollicis is a large muscle arising from
a great part of the extensor surface of both the radius and the ulna,
and from the interosseous ligament. It is imserted into the first
metacarpal. Its origin on the ulna extends almost up to the
olecranon. On the radius it is conterminous with the insertion of the
supinator brevis.

The extensor carpi ulnaris takes origin from the external condyle
of the humerus (below the other muscles there arising), and is
inserted, by a very strong tendon, into the fifth metacarpal.

The supinator brevis is a rather deeply placed muscle, which
comes from the outer condyle of the humerus and the upper part of
the ulna, and is inserted into the radius, wrapping it round some-
what from behind.

The neuscles of the fore-paw are numerous but small. The pollex
(which has no perforated flexor) is provided with a flexor brevis,
which extends from the trapezium, the trapezoides, and adjacent
deep palmar fascia, to be mserted into the base of the proximal
phalanx of the pollex.

Opponens pollicis. —This is a very small muscle, closely connected
with the last-named. Similar im origin, it is inserted into the
metacarpal of the pollex.

An abductor brevis pollicis passes from the trapezium and annular —
ligament of the wrist to the proximal phalanx of the pollex.

A flexor brevis minimi digiti arises from the annular ligament and
unciforme, and is inserted into base of the first phalanx of the fifth digit.

A few fibres with a similar origin, but inserted into the fifth mete-
carpal, constitute an opponens minimi digit.

The adductor minimi digiti is a relatively considerable muscle,
which arises from the palmar fascia at the root of the pollex, and is
inserted into the first phalanx of the fifth digit.

An abductor minimi digiti arises from the outer side of the pisi-
forme, and is inserted by a long and delicate tendon into the ulnar
side of the proximal phalanx of the fifth digit (Fig. 80, Amd).

The interossei are small muscles which arise from the sides of the
metacarpals and go to the sides of the proximal phalanges. When
the back of the paw is looked at (the other muscles being dissected —
off) four interossei, called dorsal, are to be seen as follows: one on
each side of the third digit, one on the radial side of the index, and

EE ee ee ee eS ee ee a ee ee

CHAP, V.] THE CAT’S MUSCLES. 153

one on the ulnar side of the fourth digit. When the palmar
surface of the paw is looked at, a double interosseus 1s to be seen on
the ulnar side of the index; one is also to be seen on the radial side
of the fifth digit, and we also see those which were partly visible
when the paw was viewed dorsally. We thus learn that those seen
dorsally on either side of the third digit have a common belly on

‘ the palmar surface, as also that the dorsal interosseus, which appears

on the ulnar side of the fourth digit, has a palmar division going
to the radial side of the fourth digit. In this way each digit (apart
from the pollex) has a pair of interossei, except the fifth digit, which
only has an interosseus muscle on its radial side.

These little muscles act mainly as short flexors, but also somewhat
as extensors. Each is a double-bellied muscle which divides, and
is doubly inserted: one insertion being into the first phalanx and
sesamoid beneath it, and the other extending upwards towards the
sheath of the extensor tendons, and so helping to retract the claws.

The muscles of the antcrior region of the trunk, and of the fore-
limbs, are invested by a membrane called the superficial fascia, and a
synovial membrane is placed in the subcutaneous tissue which
invests the acromion, olecranon, and joints of the paw.

A deeper, stronger fascia is placed in the axilla, which descends
the arm and becomes continuous with the annular ligaments of the
wrist, beneath which pass the flexor and extensor tendons, their
passage being facilitated by the presence of synovial membranes.

The strong palmar fascia, in which the palmaris longus ends, has
already been mentioned.

As to the stRETCH OF MUSCLES over the segments of the pectoral
limb, we have seen that some muscles which are inserted into the
shoulder- girdle proceed from the trunk, as the trapezius; others pro-
ceed from the shoulder-girdle to the upper arm, as the deltoid; others
from the upper-arm to the fore-arm, as the brachialis anticus ; and,
finally, others from the fore-arm to the hand, as the deep flexors
of the digits. But there are also muscles which pass direct from the
trunk to the upper-arm, as the latissimus dorsi; or direct from the
shoulder to the fore-arm, as the biceps; or direct from the upper-
arm to the hand, as do a great number of the muscles inserted into
the latter—the flexores, carpi radialis and ulnaris and the flexor sub-
limis digitorum, arising, as we have seen, from the inner, or ulnar,
condyle of the humerus; and the extensores carpi radialis longior
et brevior, the extensor communis digitorum and extensor carpi
ulnaris, arising, on the contrary, from its outer, or radial, condyle.
The extensors, as well as the flexors of the digits, all take origin
in the arm and not in the hand itself.

As to the prrEction of the muscles of the arm the long flexors of
the pollex and other digits are not oblique, but arise on the same
side of the limb as that on which they are distributed.

The extensors of the outer digits cross the extensors of the thumb.

As to the NUMBER OF MUSCLES WHICH MAY BE INSERTED INTO A
SINGLE DIGIT, we see that the ideal perfection of having both a flexor

154 | THE CAT. [onar, en

and an extensor inserted into every segment from the metacarpal to
the last phalanx is only attained in the *mdex and the digitus
minimus.

Thus in these digits the metacarpal bones are flexed by the flexor
carpi radialis and flexor carpi ulnaris respectively, while no other
metacarpal has a separate flexor. They are extended by the
extensores carpi radialis longior
and ulnaris respectively. ‘The
first phalanx of each is flexed
by the interossei, and extended
by the extensores indicis and
minimi digiti respectively. The

ii . second phalanx of each is flexed

Nil

esti
\

| extended by the extensor com-

munis digitorum. The ultimate
phalanx in each is flexed by
the flexor periorans and ex-
tended by subdivisions of the
‘interossel (aided by the lum-
bricales), which join the ex-
tensor sheath and are finally
inserted into the distal phalanx.

MUSCLES OF THE HIND LIMB.

Fig. 82.—SuPERFICIAL MuscLEs oF THIGH. § 10. The muscles of the
B. Biceps femoris. hip and thigh, though mainly
G. Gastrocnemius. 2 58 s
G ma and G ma. Gluteus maximus. taking origin from the pelvis
M. Semi-membranosus. =
Bees iocic and leg bones, yet partly arise
T. Semi-tendinosus. from the loins.

T a. Tibialis anticus. i e

T vf. Tensor vagine femoris. The gluteus. Maximus CON=

sists of a great sheet of muscle
and tendinous aponeurosis, and is more or less divisible into two parts :
one arises, by fascia, from the membrane covering the sacral region
dorsally, and, by some muscular fibres, from the sacrum itself; the
other part arises, by muscular fibres, from the first two caudal vertebre.
The first part is inserted into the great trochanter, at the base of its
hinder outer part. The second part of the gluteus maximus is in-
serted into the femur below of the great trochanter, by means of a
sheet of fascia (the fascia lata), which invests the thigh, dipping in
between the adductor and the vastus externus, and descending right
down to the external condyle of the femur. ;
The tensor vagine femoris is a large thick muscle which arises from

the anterior end and anterior half of the ventral margin of the ilium,

and from the dense fascia intervening between it and the first part
of the gluteus maximus. It is inserted into the fuscia data, which dips
in ‘as before said) between the adductor and the vastus externus.

>
" .

Sait || ao by the flexor perforatus and

i.

‘CHAP. V.] THE CATS MUSCLES. 155

The gluteus medius is very large and fleshy. It arises from the

whole outer surface of the ilium, and

from the fascia between the

Big. 83.—A. Deer Muscies or THIGH, BICEPS, AND, FASCIA LATA, CUT AND REFLECTED

B. MuscLes AND TENDONS OF O
A, Adductor. ‘
Amd. Abductor minimi Uigiti.
B. Biceps femoris cut short.
Ebodd. Extensor brevis digitorum.
Eid. Extensor longus digitorum.
Fl. Fascia lata.

F 1h. Flexor longus fiallucis.

G1, G3, G4, Gastroenemius.

Gd. Gluteus medius.

G mz! and 2. Gluteus maximus.
M. Semi-membranosus.

P b. Peroneus brevis.

Pl. Peroneus longus.

UTER SIDE OF ANKLE.

Pqd. Peroneus quinti digiti

Pin. Plantaris.

Ps. Psoas.

Qf. Quadratus femoris

S. Sartorius.

Sol. Soleus.

T. Semi-tendinosus.

T a. Tibialis anticus.

Ts. Tenuissimus.

T vf. Tensor vagine femoris.

The rectus femoris is shown in the angle
between Gd and Vex.

gluteus maximus and the tensor vagine femoris. It is inserted into

the great trochanter.

ri ale THE CAT.

The gluteus minimus arises from the ventral part of the outer
surface of the ilium behind and beneath the muscle last described ;
also from the anterior part of the ischium, above the acetabulum. It
is inserted also into the great trochanter.

The gluteus quartus is a very small and delicate muscle which
arises in front of the acetabulum just outside the origin of the rectus
femoris. It is inserted into the front of the femur on the inner side
of the great trochanter, ¢.e., to the middle of the anterior inter-
trochanteric line, passing down between the vasti.

The pyriformis takes origin from the ventral surface of the
sacrum. It passes out of the great sacro-sciatic notch (superficially
to the great sciatic nerve, and in close apposition to and somewhat

connected with the hinder surface of the gluteus minimus), and is -

inserted into the great trochanter within the insertion of the gluteus
medius. This and the following muscles, up to and including the
quadratus femoris, rotate the hind limb outwards.

The obturator externus arises from the outer surface of the ob-
turator membrane and the bony margin surrounding it. Passing at
first upwards and backwards, it ends in a strong tendon which turns
outwards, and is inserted into the trochanteric fossa.

The obturator internus arises from the mner surface of the ob-
turator membrane and its bony frame. Its fibres converge to a
tendon which ascends, curves round the ischium and passes out-
wards and forwards to be inserted into the trochanteric fossa.

The gemellus anterior is a very small muscle which arises from the
spine of the ischium and is inserted into the anterior margin of the
tendon of the obturator internus.

The gemellus posterior is a muscle similar to the last in size and
insertion, but which takes origin from the tuberosity of the ischium.

The quadratus femoris 1s a muscle which proceeds from the

tuberosity of the ischium and the margin of the ischium below it, to.

the posterior imtertrochanteric line and posterior surface of the
femur at the lower end of the great trochanter (Fig. 88, A, Q/).

Psoas magnus is a large muscle arising from the interior of the
trunk and passing out beneath the brim of the pelvis. It arises
beside the diaphragm from the transverse processes of all the
lumbar vertebree, and is inserted into the lesser trochanter of the
femur (Ps).

Itiacus.—This muscle is represented by fibres which arise from
the inner surface of the ilium and blend with the psoas magnus.

The psoas parvus is but a subdivision of the psoas magnus, which
subdivision ends in a strong tendon inserted into the ilio-pectineal
eminence.

The quadratus lumborum is a muscle which arises (by a strong
tendinous origin) from the outer margin of the ilium, half an inch
behind its anterior end. Its fibres become closely connected with
those of the psoas magnus, along the under surface of the lumbar
transverse processes and onwards to the body of the twelfth dorsal
vertebra.

CHAP. V.] THE CAT’S MUSCLES. : 157

These three muscles bend the pelvis or thigh upon the body, and

vice versa, and are of great use in running, bounding, and climbing.
The pectineus is a muscle which descends from the most anterior

part of the symphysis pubis and ventral part of the brim of the pelvis
to be inserted into the ridge which descends from the lesser tro-
chanter to the linea supra, and into the lmea itself. It is a small
thin muscle, yet it extends half way down the thigh. }

Except at its uppermost part it is inserted by iascia which is
much connected with the muscle next described.

The adductor is a very large muscular mass, and is more or less

Fig. 84._-MUSCLES OF INSIDE OF THIGH, SARTORIUS AND GRACILIS BEING CUT AND REFLECTED.

A. Adductor. Pop. Popliteus.

Ai. Abductor indicis. Ps. Psoas.

Ez bv. Extensor brevis digitorum. Rf. Rectus femoris.

Elid. Extensor longus digitorum. S. Sartorius.

Fld. Flexor longus digitorum. Sol. Soleus.

Fih. Flexor longus hallucis. 7. Semi-tendinosus.

G2. Gastrocnemius. T a. Tibialis anticus.

Gr. Gracilis. T p. Tibialis posticus.

M. Semi-membranosus. T v f. Tensor vagine femoris.
Pec. Pectineus. ' Vim. Vastus internus,

Pin. Plantaris.

incompletely divisible into several parts. It arises from the symphysis
pubis, and from the pubis and ischium at each end of the symphysis.
It is inserted by muscle into the whole length of the linea aspera,
and into the space between the inferior bifurcation of the linea
aspera, at the lower end of the back of the femur. It is closely
connected at its insertion with the inner head of the gastrocnemius.
The sartorius arises from the most anterior part of the ventral
margin of the ilium. It spreads out into a broad muscular sheet
which invests the front and antero-internal part of the thigh, and

.'o"- =.=

_

“eT een Abdi alberta

158 THE CAT, | comieese

is ultimately inserted into the ligament of the patella and internal
tuberosity of the tibia. Some of its muscular fibres extend down to
the tibia below its inner tuberosity.

The gracilis is a wide, flat, muscular sheet, which arises by
tendinous fascia from beneath the symphysis pubis, and is similarly
inserted into the inner side of the tibia, its broad insertion being
overlapped by the sartorius. Like the preceding muscle it is @
flexor of the leg on the thigh.

Semi-tendinosus.—This is a long, subeylindrical muscle, which arises
by tendon and fascia from the tuberosity of the ischium, beneath
and a little behind the origin of the biceps femoris. It is inserted
partly into the tendinous sheath of fascia which goes to the inner
side of the tibia, and partly, by a very strong tendon, into the front
of the tibia, about half an inch below the patella (Fig. 84, T').

The semi-membranosus is very thick and fleshy, and more or less
double. It arises from the tuberosity of the ischium, and from the
ramus of the ischium below the tuberosity down to the symphysis.
It is much united in its course and insertion with the adductor. It
is inserted into the inner condyle of the femur and above it up to the
insertion of the adductor, and also by a strong tendon (which passes
beneath the internal lateral ligament of the knee) into the internal
tuberosity of the tibia (Fig. 74, sm). The part with the latter msertion
arises within the origin of the other part, the muscle being near its
origin folded on itself, with the opening of the fold forwards. The
two parts are entirely separable for the last inch of their course. The
part inserted into the inner condyle is closely connected with the
internal head of the gastrocnemius,

Biceps femoris.—This 1s an enormous sheet of muscle, the fibres of
which expand in a fan-like manner (Fig. 82, B). It arises (by muscle
and strong tendon) from the tuberosity of the ischium, somewhat
between the origin of the semi-tendinosus and semi-membranosus, but
anterior to both. It is inserted by a tendinous fascia into the outer
side of the leg from the top of the knee-joint nearly to the heel, but
it is especially inserted into the outer tuberosity of the tibia.

The three muscles last described are called the hamstring muscles,
and are powerful flexors of the leg. ae

Tenuissimus (Fig. 83).—This most delicate muscle arises from the
caudal vertebre at the front end of the second part of the gluteus
maximus, with which it is intimately united. Passing down beneath
the gluteus maximus and inside the biceps, it ends by blending with
the imner surface of the latter muscle close to the anterior end of its
inferior margin.

The quadriceps extensor, or great extensor of the leg, consists of
four parts, which have a common insertion into the tendon of the
patella, and, through it, into the tuberosity of the tibia.

The first part is the rectus femoris, and arises from the hinder
part of the ventral margin of the ilium, and, by a tendon, from the
antero-superior margin of the acetabulum.

The second part, or vastus externus, is of enormous size, wrapping

CHAP. V.]

round the rectus femoris in front. It
arises from the whole outer surface of
the femur and great trochanter.

The third part, or vastus internus,
springs from the inner side and front of
the femur, right up to the capsular liga-
ment (Fig. 84).

The fourth part, or crureus, arises from
the lower half of the front of the femur.

The leg has five long muscles in front
and seven behind.

The tibialis anticus takes origin from
the fossa on the outer side of the upper
fourth of the tibia. from the adjacent part
of the fibula, and from the intervening
inter-osseous ligament. It is inserted by
a strong tendon into the dorsum of the
rudimentary first metatarsal. It covers
over the upper third of the extensor
longus digitorum, and its action is to
bend the foot forwards and inwards on
the leg.

The extensor longus digitorum sedis
arises by a strong tendon from the pit on
the femur, which is situate just outside the
outer margin of the groove for the patella.
At the ankle it passes through a strong
tendinous loop devoted to it alone, and
which loop is attached to a concavity
on the upper surface of the os calcis, in
front of (below) the astragalus. Before
passing through the loop it is already
divided into four tendons, which go to
the exterior sheaths of the four digits.

The peroneus longus is a very notable
muscle which takes origin from the head
of the fibula around the attachment of
the external lateral hgament. It ends
by a tendon which passes down in front
of the external malleolus in a special
groove in the front of the fibula, which
groove is bridged over by a tendinous
arch lined by synovial membrane.
Passing superficially to the tendons of
the two muscles next described, it dips
in beneath the deepest plantar muscles,
and traversing the channel formed for
it by the groove beneath the cuboid and
the peculiar process of the ento-cuneiforme,

THE CAT’S MUSCLES.

ig. 85.—FLeExoR MUSCLES OF

LEG, THE GASTROCNEMIUS, PLAN-
TARIS AND SOLEUS BEING REMOVED.

Aland A2. Accessorius.

Fb. Flexor brevis digitorum,
cut and reflected.

Fld. Flexor longus digitorum.

F lh. Flexor longus hallucis.

Gex. External head of Gastro-
cnemius.

Gin. Internal head of ditto.

Z1,?,and%. Lumbrical muscles.

Oc. Os Calcis cut short off.

P b. Peroneus brevis.

Pl. Peroneus longus.

Pop. Popliteus.

Pqd. Peroneus quinti digiti.

Sol Soleus.

T fp. Tendon of deep flexor
muscle .

T p. Tibialis posticus.

160 THE CAT. | [CHAP vy.

it ends by being implanted into the inner end of that groove close te

and at least indirectly connected with the mmute innermost meta- —

tarsal—that of the hallux.

This muscle aids in walking by pulling up the inner side of the
foot, and indirectly pressing the distal ends of the inner long meta-
tarsals upon the ground as a fulcrum.

The peroneus brevis arises from the front and outer side of the
lower half (or more) of the fibula—except close to the external
malleolus. It ends in a tendon which passes behind the external
malleolus, and beneath the tendon of the peroneus longus, and is
inserted into the proximal end of the fifth metatarsal.

The peroneus quinti digiti springs from the upper and outer half
of the fibula, and ends by a slender tendon which passes, in a
synovial sheath, behind the external malleolus, and is inserted into
the dorsum of the proximal phalanx of the minimus digit,

The extensor brevis digitorum pedis is a short muscle which takes ©

origin from the concavity on the distal part of the dorsum of the

os calcis and from the dorsum of the cuboid. It divides into three .

bellies, each of which ends in a strong tendon. The innermost tendon

divides at about the distal end of the metatarsals, one division going

f the proximal phalanx of the index, the other to that of the third
igit.

The second tendon similarly divides, and goes to the third and
fourth digits.

The third and outermost tendon goes to the fourth digit only.

Thus the fifth digit receives no tendon from this muscle.

Of the muscles behind the leg the largest is the gastrocnemius.
Two heads respectively arise from the two sesamoids, which are

laced one behind each of the two condyles of the femur.

Another (third) head arises from the ligamentum patella in
common with the plantaris.

A fourth head (Fig. 83, *) arises from the fascia investing the
peronei muscles and fibula. The third and fourth heads, with the
head from the sesamoid behind the external condyle, unite inextric-
ably with the plantaris. The head from the sesamoid behind the
internal condyle remains long distinct, but ultimately unites with the
other heads which, all having united, end below in a strong tendon
—the tendo Achillis—which 1s inserted into the hinder part of the
tuberosity of the os calcis, superficially to the insertion of the
soleus. Close to the heel, the tendon passes to the peroneal side of
that of the plantaris, the latter there appearing and becoming
superficial to it (Fig. 84).

The plantaris arises from the ligamentum patellze in common with
the third head of the gastrocnemius. Below this origin it 1s closely
mixed up with the outer parts of the gastrocnemius—though well
distinguished from the inner part of the latter. It forms below
a strong tendon, which becomes visible just above the tuberosity
of the os calcis on the tibial side of the tendo Achillis. It then
expands and glides over the pulley-like surface of the calcaneal

CHAP. V.] THE CATS MUSCLES. 161

tuberosity—its passage becoming facilitated by synovial membrane.
It ends in the plantar fascia, which invests the under surface of -
the foot and gives origin to the flexor brevis digitorum.

The soleus arises from the summit of the back part of the
fibula and is inserted into the tuberosity of the os calcis beneath
(t.e., covered in by) the tendo Achillis.

These three muscles raise the heel and are great agents in
jumping.

The popliteus is a short oblique muscle, which takes origin by
a thick tendon from and just outside the external condyle of the
femur. It is inserted on the posterior surface of the tibia, above
the oblique line and conterminous with the origins of the tibialis
posticus and flexor longus hallucis (Fig. 85). soe

Flexor brevis digitorum or perforatus.—This muscle takes origin
from the plantar surface of the plantar fascia of the plantaris. It

is made up of four small muscles, placed side by side, which send

tendons to the four digits; the muscle and tendon going to the fifth
digit being the most slender. These tendons go to the second pha-
langes, but each splits opposite the proximal phalanx to allow a tendon
of the flexor longus to pass through the perforation thus formed.

The flexor longus digitorum pedis or preforans is rather small, and
arises from the hinder surface of the tibia, below the popliteus,
from the summit of the fibula and from the intermuscular fascia
between it and the tibialis posticus. It ends below im a tendon
which passes down a groove behind—or rather on the inner side
of—the internal malleolus. This groove is lined by a separate
synovial membrane, and is just behind that for the tibialis posticus.
The tendon passes into the plantar region and ends by dividing
into four tendons, which are inserted into the distal phalanges of
the digits after perforating the tendons of the flexor brevis.

The flexor longus hailucis is a large muscle which takes origin
from the back of the fibula and tibia and interosseous ligament
—hbelow and external to the origin of the last described muscle. It |
ends in a tendon which passes in a synovial sheath behind the
internal malleolus, and beneath the sustentaculum tali of the os
calcis in a deep groove. It ends by coalescing with the tendon of
the flexor longus digitorum. Itis much connected with the peronei
which border it externally.

Lumbricales.—There are three of these muscles in the hind-paw,
and they resemble those of the fore-paw. One passes from between
the deep flexor tendons of the index and third digits to the tibial
side of the third digit. The second goes from between the deep
tendons of the third and fourth digits to the tibial side of the
fourth digit, and the third goes from the deep flexor tendon of
the fifth digit to the tibial side of the same digit.

Accessorius.—This is a very small muscle of two bellies, which
arise on the plantar surface of the conjoined deep flexor tendon,
and end by two delicate tendons, which join the tendons of the flexor
brevis, going to the third and fourth digits (Fig. 89).

162 ve PHB COAT. ea [cHAPe 9. Se

Tibialis posticus.—This muscie lies deeply and takes origin from
the hinder side of the tibia beneath the popliteus, and from the
hinder surface of the head of the fibula. It ends below in a tendon
which passes down the internal malleolus in a special groove placed
close to, but in front of, the groove for the flexor longus digitorum.

It ends by being inserted into the prominence at the hinder part of —

the inner border of the naviculare. This muscle is naturally quite
covered in by the flexor longus digitorum, save where its tendon
appears in front of that of the last named muscle. 3 |

The abductor indicis is a small muscle arising from the plantar

fascia and tarsus at the root of the rudimentary hallux, and is —

implanted into the tibial side of the proximal phalanx of the index.

Opponens minimi digiti.—This is a narrow muscular band which
arises from the plantar fascia at the root of the index digit, and is
inserted into the metatarsal of the fifth digit.

Abductor digiti minimi.—This arises from the plantar surface of
the os calcis, and is inserted by a delicate tendon into the peroneal
side of the proximal phalanx of the fifth digit.

The interosset are a set of small muscular bundles—two to each
digit, except the rudimentary hallux. They all take origin from
the plantar surface of the proximal ends of the metatarsals, and
pass upon either side of these bones to their distal ends. There
they are inserted partly into the sesamoid bones (placed one beneath
the distal end of each metatarsal) and partly they ascend (lke those
of the fore-paw) to be inserted into the extensor tendons.

The pelvic limb is, like the rest of the body, clothed with a
subcutaneous superficial Fascta. In the thigh this takes the name
of fuscia lata, and is very dense (especially on the outer side of the
limb) and sends down expansions between the muscles, one larger
expansion penetrating to the linea aspera.

The aponeurosis of the leg is continuous at the ankle with the
anterior annular ligament, beneath which pass the extensor tendons.

The internal annular ligament passes from the imner malleolus to
the heel, and transmits the flexor tendons.

The external lateral ligament passes from the outer malleolus to
the heel, and transmits the tendons of the peroneus longus and
peroneus brevis.

In the foot, as in the hand, synovial bursee facilitate the passage
of the tendons.

As to the strETCH oF muscLEs over the segments of the pelvic
limb, there are certain muscles inserted into the pelvic girdle and
proceeding to it from the trunk—as the abdominal muscles and psoas
parvus; others proceed from the pelvic girdle to the thigh, as the
glutei; others from the thigh to the leg, as vastus externus and
internus, and the crureus; and finally, others from the leg to the
foot, as the deep flexors of the digits.

But muscles may pass directly from the trunk to the thigh, as the
psoas ; or directly from the pelvic girdle to the leg, as the ham-string
muscles; or directly from the thigh to the foot, as the gastrocnemius.

CHAP. V.] THE CATS MUSCLES. 163

None of the muscles, however, which go to the digits arise from
the femur, except the extensor longus digitorum pedis, while, on the
contrary, some of the flexors and extensors—as the flexor brevis and
the extensor brevis—take origin not in the leg but in the foot
itself.

As to the NUMBER OF MUSCLES WHICH MAY BE INSERTED INTO
A SINGLE DIGIT, we see that the ideal perfection of having both a
flexor and an extensor inserted into every segment from the meta-
tarsal to the last phalanx is only nearly attained in the digitus
minimus. Thus its metatarsal is flexed by the peroneus brevis and
extended by the peroneus tertius. Its first phalanx is flexed by the
interosseus, and is more or less extended by (though it receives no
tendon from) the extensor brevis. The second phalanx is flexed
by the flexor brevis or perforatus, and is extended by the extensor
digitorum longus. The third phalanx is flexed by the perforans or
flexor longus, and more or less imperfectly by the interosseous and
lumbrical muscle.

Besides these muscles the digitus mimimus has also an abductor
and an opponens.

§ 11. The pirrErENcss between the muscles of the fore and hind
limbs are the following :—The flexors and extensors of the pelvic
limb arise lower down than do those of the thoracic limb. Nothing
in the fore limb answers to the peroneus longus of the hind
limb, while nothing in the leg answers to the supinator longus or
to the extensores carpi radialis longior and brevior of the arm.
In the fore-paw there is no accessorius, and its perforated muscle
is a long one, while in the hind-paw it is a short muscle. There
is a second (short) extensor of the digits im the hind-paw, there is
none in the fore-paw. There is no long extensor tendon to the index
and fourth digits of the hind-paw. The deep flexor tendons spring
from one tendon in the fore-paw, from the conjoined tendons of
two muscles in the hind-paw.

In the foot, the hallux being a mere rudiment, it has not muscles
corresponding with those which the pollex has. Again, the hind-paw
has that very peculiar muscle—the accessorius—to which nothing
in the fore-paw appears to correspond.

The AGREEMENTs between the muscles of the two limbs may
be expressed as follows:—The supra and infra-spinatus and teres
minor are inserted into the pre-axial tuberosity, while the psoas
and iliacus are inserted into the pre-axial trochanter. The sub-
scapularis and teres major are inserted into the post-axial tuberosity,
the glutei are inserted into the post-axial trochanter.

The triceps is the great extensor of the arm and the quadriceps
of the leg. The biceps of the arm seems to be represented by the
gracilis and sartorius of the leg. The coraco-brachialis corresponds
with the adductor; the extensor ossis metacarpi pollicis with the
tibialis anticus; the flexor carpi ulnaris with the peroneus brevis,
and possibly also with the soleus and the gastrocnemius; the

extensor carpi ulnaris with the peroneus tertius; the flexor carpi
M 2

164 THE OAT. [CHAP. V.

radialis with the tibialis posticus; the flexor digitorum profundus
with the flexor longus digitorum; the flexor digitorum sublimis
with the flexor brevis digitorum ; the extensor communis with the
extensor longus digitorum ; the palmaris longus with the plantaris ;
the pronator teres with the popliteus; while the lumbricales and
interossei generally correspond in spite of the slight differences
already noted.

§ 12. Considered independently of the bony skeleton, the
muscular system of the cat may, as its simplest expression, be con-
ceived as a fleshy envelope of the body which takes the form,
ventrally, of three superimposed layers (the fibres being directed
differently in each layer), and dorsally, of a number of very various
longitudinal bundles, ending in tendons directed more or less
obliquely forwards. In the tail the envelope consists of longitudinal
bundles, which, below as well as above, end in tendons directed
more or less obliquely backwards. In the head, the muscular
envelope becomes complicated for the hyoid, jaws, and organs of
sense. The muscles of the limbs may be conceived as sheaths of
fibres forming a. median and two lateral groups of muscles, both on
the extensor and flexor surfaces of each limb, with special modifica-
tions and subdivisions where each limb becomes subdivided into its
terminal digits.

CHAPTER VI.

THE CAT'S ALIMENTARY SYSTEM.

§ 1. In the first chapter ofthis work it was pointed out that the
great function of sustentation * was in part brought about by the
process of alimentation and in part by secretion.

ALIMENTATION is effected by the reception of new elements into the
very ultimate substance, or parenchyma, of the body. This process
is called assimilation, and consists in the transformation of what is
immediately external to the parenchyma into the parenchyma itself
—the change of the flesh and blood of other creatures into cat-flesh
.and cat-blood. As to this process, science can only say that it is
performed, the ultimate “how ” of the transformation is an altogether
insoluble problem.

Nevertheless certain physical properties and conditions, to be
adverted to shortly, help us to understand various digestive and
other processes which serve and lead up to the final act of assimila-
tion. Assimilation is always effected from a fluid medium derived
from the food; but in order that the food should be able to supply
the body with such a medium, it must, sooner or later after its
reception, undergo a certain process of preparation. Thus the
whole process of nourishing ‘the body by food—the process of
alimentation—is made up of three subordinate processes: (1) the
reception of the food, (2) its preparation, and (8) its assimilation.

But that the life of the cat may be maintained, nutriment is by
no means the only requisite. It is also necessary that a certain tem-
perature should be maintained by a constant process of oxygenation
of the body’s substance, which temperature may be greatly above or
somewhat below that of the surrounding air. Thus two classes of.
supply are called for: (1) matter for the nutrition of the tissues,
(2) matter to serve for the production of warmth. Both these
matters together constitute what is known as “food.”

§ 2. As to the kinds of Foop required by the animal we are
considering, it must evidently be supplied with what contains the
requisite materials for forming all its tissues, since all of them, even
the very bones, are being slowly changed and renewed piecemeal

* See ante, p. 10.

166 THE CAT. [CHAP vn

during life. Now every tissue, as we have seen, can ultimately be
reduced to oxygen, hydrogen and carbon, with or without nitrogen,
and a few other elementary substances, in greater or less.
quantity. But let the cat be supplied, however plentifully, with
these elements in whatever forms or combinations which are merely
chemical, and it would none the less infallibly starve ; for it has no
power of building up from inorganic matter, the very complex sub-
stances of which its body is formed. It absolutely requires to be
supplied with compounds which have been ready formed for it by
other creatures—it must feed on living or recently dead animal or
vegetable substances. Such inorganic matters as water with the
salts which may be dissolved within it, do, however, form part of
its food.

The organic substances on which it lives, may, lke its own
tissues, be divided into the nitrogenous and the non-nitrogenous,
and there are two sets of each of these kinds.

One set consists of albuminoid substances, such as the blood and
flesh of the animals on which it may prey. Their connective tissues,
cartilage, and bone, are examples of gelatinoid substances, and of
such the second set of nitrogenous foods consists.

Oleaginous substances (or fats and oils) and amylaceous substances
—sugar, starch, and gum—are the two sets of non-nitrogenous
foods. The last set are mainly of vegetable origin, but there is a,
sort of starch (glycogen) in the livers of animals, while muscle has
a sugar of its own (inosite), and there is a sugar of milk.

Much oxygen (as we shall hereafter see) 1s also received into
the body by the lungs in respiration.

The products of that waste of the tissues which is inseparable
from the wear and tear of life (and which uecessitates the acquisition
of food) are eliminated in various ways by the lungs, kidneys, and
skin, and the undigested residue of what has been eaten is cast forth
from the alimentary canal itself.

The process of nutrition effected by food is, in the early life of
the animal, greatly in excess of waste, but at maturity a prac-
_ tical equilibrium is established, which is maintained till, with the
advance of age, the balance at first existing becomes reversed.

§ 3. As has been said, secretion 1s closely connected with alimen-
tation. That it must be so will clearly appear if we reflect that
“secretion”? is an action by which certain portions of the body
extract from the blood new substances (the various secretions)
which do not exist as such within it, and that “ nutrition” (the
culmination of the alimentary process) is an action by which
certain portions of the body extract from the blood new substances
(the various tissue-substances) which do not exist as such within it..
Every part of the cat’s body which can be nourished must necessarily
have this power or the cat could not repair the effects of its own
waste when adult, or “grow” during immaturity. In “ nutrition,”
however, the formed product enters into the composition of the
body itself, while in secretion this is not (directly at least) the case

at iad

CHAP, VI.] THE CATS ALIMENTARY SYSTEM. 167

—the product being discharged from some surface external or

internal.

_ But in fact it is not the blood alone which isin all cases the direct
source of nutrition, since the blood has the power of replenishing
itself and repairing its losses out of the fluids obtained from the
food. The mtimate way in which assimilation takes place, is
named INTUSSUSCEPTION, to distinguish it from any growth which may
take place by mere external addition—as when a crystal grows,
while suspended in a suitable medium, by the deposition of fresh
matter on its surface.

Another process, which is ancillary to nutrition and secretion, is
termed ABSORPTION, which is the generic term applied to the intro-
duction into any tissue of the body, of substances external to it,
and thus nutrition, or assimilation, itself is, in fact, one form of
absorption. The process of absorption is aided by the physical
properties termed endcsmosis and exosmosis, terms which denote the
passage of fluids in opposite directions through dead animal
membranes ; different fluids, when thus divided, tending to pass
through to the other side of such membranes with different degrees
of rapidity.

Dialysis is the term used to denote this movement of transfusion,
irrespective of its direction, and therefore includes both endosmosis
and exosmosis.

§ 4. It has been found that different substances may be arranged
in two classes according to their diffusibility, and that this division
coincides with certain other characters which the two classes, termed
respectively CRYSTALLOIDS and coLLoips, present. All crystalloid
bodies are crystallisable ones. When dry, they are hard, rigid, and
quickly soluble; their solutions are never viscous, they are always
more or less sapid, and they are highly diffusible. Colloids do not
crystallize, anc when dry they are tough. They dissolve slowly, and
their solutions are more or less viscous ; they are insipid, and they
diffuse with difficulty. Albuminoid and gelatinoid substances are
colloids.

Dialysis doubtless takes place in the living body: as in secretion,
nutrition, and absorption, and it is possible that some such process
may be the cause antecedent to muscular contraction. All salts and
other crystalloid matters, whether useful, indifferent. or hurtful,
readily find their way ito the substance of the body from the
alimentary canal, but, as we shall see later, this ready penetration
of very diffusible substances is not the same thing as true intestinal
absorption where a selective power is manifested. This latter active
kind of absorption is, as has been already said, analogous to
secretion.

§ 5. The consideration of the distinctions which exist between
colloids and erystalloids leads us to the last preliminary considera-
tion, namely, to that of the process of picrstion. ‘This process
consists in the reduction of food to a state in which it can be readily
taken up into the system, and since it cannot be so taken up except

168 | THE CAT. etwe naga

by passing through the substance of limiting membranes, it is”
obvious that this process must be synonymous with an increase of
the food’s diffusibility, a quality acquired in part by a change in
its chemical composition, in part by its very minute subdivision.

Minute subdivision is produced by mastication, by the contraction
of the walls of the alimentary canal, and by the influence of fluids
poured into that canal, and which reduce the fatty matter of the
food to the condition of an emulsion.

Diffusibility is produced by a transformation of colloids into
crystalloids, starchy matters being changed into that highly soluble
crystalloid, sugar; and the albuminoid and gelatinoid substances,
being transformed into albumen-peptone and gelatin-peptone, both
of which are capable of ready absorption. These transformations
are effected by the agency of certain fluids which different parts
of the alimentary organs secrete and pour into the alimentary
tract.

These facts and considerations throw a certain light on the process
of alimentation. But any explanations to be thence derived are
manifestly most complete, because the very living membrane itself
can cause changes in the fluid itself as it passes through it, and the
living particles of parenchyma exercise a certain power of choice
with respect to the contents of the fluids in contact with them.
Such particles are not passive bodies, but active, living agents, and
their action no one has yet really explained.

§ 6. The processes of alimentation may then be SUMMARIZED as
follows :—

To support life by due repair of waste, and the maintenance of
the necessary body temperature, food is required of such a nature as
to furnish the substance of the tissues, and to serve as fuel. This
food must be minutely comminuted, or rendered soluble by me-
chanical action, and by the influence of suitable fluids. When this
process of digestion has been accomplished, the nourishing product
becomes more or less completely absorbed, and, passing into the
blood-stream, regenerates it, and through it supplies every part of
the frame with fresh material, which is taken up by internal
assimilation or mtussusception, and transformed into the substance
of the living body—the non-nutritious, non-absorbed residua being
discharged. 7

This great function is subserved by an elaborate apparatus,
commonly known as the stomach, intestine, &c., with their annexed
organs. It may be shortly described as a convoluted tube of
different capacity in different parts, passing from one end of the
body to the other, with two terminal apertures and with muscular
walls, the fibres of which are so arranged as, by their regular,
alternate contraction and relaxation, to drive the contents of the
tube onwards from its anterior to its posterior termination. '

The anterior part of the tube is enlarged and specially modified
to serve for the reception of the food, its subdivision and preparatory
moistening by certain fluids. This is the buccal cavity, or mouth,

CHAP. VI.] THE CATS ALIMENTARY SYSTEM: 169

with its lips, jaws, teeth, tongue, palate, fauces, and salivary or
spittle glands.

Next follows the part immediately behind the mouth, called
the pharynx, which opens into the gullet or csophagus, which
perforates the diaphragm and leads into that dilated chamber the
‘stomach. To this immediately succeeds the small, and afterwards
the large, ntestine—with a blind off-shoot, the cecum, at their point
of junction—the whole terminating by that part of the canal which
is called the rectum. Annexed to the canal (pouring fluids into it
of great importance to the alimentary function) are the pancreas and
the diver, and that part of this whole complex system of organs
which is behind the diaphragm, lies suspended in the abdominal
exivity by a delicate and very complexly-folded membrane, the
peritoneum.

As we have already seen* in the second chapter, the skin which
is reflected inwards at the mouth, nostrils, and other body apertures,
assumes a soft and delicate texture with a moistened surface, and is
known as mucous membrane. We have also seen that the whole of
the alimentary tube, and the structures opening into it, are lined by
this membrane. The epithelium, which everywhere invests its
surface, may be of the columnar fourm (as in the stomach and
intestine), or spheroidal, as in the linings of the alimentary glands.
Its corium may contain abundant connective tissue (with many
elastic fibres), as in the gullet, or there may be but little, as in the
walls of the stomach. It may be so richly supplied with minute
blood-vessels, immediately beneath the basement membrane, as to
seem almost made up of them, while its deepest layer often consists
of non-striated muscular fibres. It is also richly supplied with
nerves, but their number varies greatly in different regions, as does
the sensibility of the parts.

As to the form and nature of the prominences—villi, papilla,

&e.—which beset its surface, they also are very different in different
parts of the alimentary tube.
_ § 7. A fluid, named mucvs, is almost universally present where
mucous membrane exists, and gives its name to that membrane.
It is an alkaline or neutral secretion, viscid, colourless, and clear
or slightly turbid. It consists mainly of water, but has from 4 to
6 per cent. of solid matter, and contains corpuscles. Its special
constituent is an albuminoid substance named mucin, which is the
cause of its viscidity. Mucus is formed by the epithelial cells of
mucous membrane, but especially by certain branching or “ race-
mose”’ glands. Its use is to preserve the moisture of the membrane,
and also to protect it from the dissolving action of the various
digesting fluids. It doubtless also helps the senses of taste and
smell, partly by preserving the moisture of the surface of the organs
of those senses; partly by helping to dissolve the various sapid
matters.

* See ante, p. 25.

170 | THE OAT | [CHAP. VI.

§ 8. The cat’s Mourn is bounded externally by the lips, which —

form a single fold around the lower jaw, and two folds, separated
by a median notch, around the upper jaw. Inside the lips, folds of
membrane called frena, proceed inwards, and bind them to the
-eums, which are masses of dense fibrous tissue investing the alveolar
margins of the jaw-bones aud covered by mucous membrane of a
smooth and highly vascular
character. lLaterally, the
mouth is bounded by the
cheeks; it is bounded below
by the tongue and the soft
parts which connect the
tongue with the mandible.
Above, it is bounded by
the palate within the upper
alveolar margin. The lips
and cheeks are composed
of muscles and skin (as
already described), together
with blood-vessels, nerves,
and: fat. The mucous

a , Wise lining of the mouth abounds
I WNW E . A
Sa WZ y in small glands, of which

those inside the lps are
called ‘labial’? and those
inside the cheeks “ buccal.”
On the palate, the mucous
ap. Anterior palatine foramen. “7°

ed rs membrane, where it invests

In this view the small upper molar is wel seen, as 5 : C
also the inner tubercle of the sectorial tooth the bones, is raised into
about eight (Fig. 86) curved,
transverse, permanent ridges or ruge. Beyond the bones, the palate
is continued for a long distance as ‘‘the soft palate”’ (investing the

AYN, (GA
: i TIAL
‘\\ au ( (t if

Fig 86.—PALATE.

muscles already noted), and which hangs down from the hinder edge »

of the palatine bones like a curtain, and is therefore called the
velum palati. The palate abounds in small “ palatine glands.”
The middle part of the free edge of the velum presents a slightly
marked notch. ‘Two folds of membrane descend, diverging as they
descend, from either end of the velum (see Fig. 87, p, and in
front of ¢). These folds form what is called the anterior and
posterior “ pillars of the fauces,” or the isthmus faucium. The term
‘“fauces”’ 1s used to denote that posterior aperture of the mouth
which is bounded laterally by these pillars, above by the velum, and
below by a structure rising up behind the tongue, and hereafter
to be described as the “ epiglottis.”’ |

Between the anterior and posterior pillar of the fauces on each
side is a large horizontally-placed crescentic depression (with numer-
ous openings of follicles* scattered over its floor), called a tonsdd
(Fig. 87, ¢). The use of the tonsils is unknown.

* A ‘‘follicle” is a minute simple bag-shaped gland.

CHAP. VI.] THE CAT’S ALIMENTARY SYSTEM. 171

The parts destined to subdivide the food, the teeth, have been
already described.* ‘The adaptation of the sectorial teeth for the
division of flesh is manifest and admirable. The canines are not
used for dividing the food. They are
weapons for seizing and destroying
prey, or for combat. The incisors are of
little functional utility, but they help
to scrape off flesh and sinews from the
surfaces of bones. The upper true
molars are so small as to be of little
service, but their shape and _ position
adapt them for crushing any suitably
sized object (such as a small piece of
bone) which may have been taken into
the mouth.

§ 9. The toneus fills up the cavity
of the mouth between the horizontal
rami of the mandible. It is a mus-
cular mass, coated with mucous mem-
brane, attached behind to the hyoid
and below to the membrane of the floor
of the mouth, but with a free apex.
It is long and flat, with nearly parallel
sides, tapering slightly in front and
more so at its posterior attachment.

Its fleshy mass 1s principally composed
of transverse fibres which pass directly
right and left from a central, vertical
membranous septum. This massof trans-
aemeniores isiraversed by ascending /((Ms- 8 Donut, or raz, Toxeue
fibres of the genio-hyoglossus muscle, is pes setae,
and is coated externally by longitudinal op cneumabiate Hapa,
fibres which form its cortical muscular * Fungilorm papil'a.
layer. Above and below, these fibres Caneel: Gee it
belong to two muscles; one, called rea cha
the lingualis superficialis superior, pro-
ceeds forwards from the basi-hyal, and
the other, called the lingualts superficialis inferior, passes thence on
each side of the ascending fibres above mentioned. The lateral
longitudinal fibres come from the stylo-glossus and hyo-glossus.
This mass of muscular fibres enables the tongue to move freely in
all directions and to modify its own shape.

Imbedded in the areolar tissue of the septum and near the lower
surface of the tongue is a spindle-shaped body (formed of fibrous
tissue, fat and muscular fibre), connected anteriorly with the
mucous membrane of the tongue, and tapering off behind till it is
lost in the tissue of the septum. This body is the /ytta or “worm.”

SHLBmS

* See ante, p. 27.

OE ee a ee ee a

172 THE CAT. (CHAP. v1,

Its function is unknown, but it is supposed to help the tongue in its
lapping action.

- The mucous membrane, which invests the tongue, forms a fold
beneath it and in front (attaching it to the lower jaw) termed the
frenum lingue, and thence it is continued onwards (over the muscles
forming the soft floor of the mouth) till it reaches the gums. A
minute process—the salivary papilla—projects forwards on each
side of the freenum.

The upper surface of the tongue is flat, with a depressed area
behind, which is bounded posteriorly by the epiglottis—or cartilage
guarding the entrance to the windpipe.

The surface of the tongue is smooth beneath, but above it is beset
with papille of four kinds:—

‘1.) The first are the circumvallate papille, each of which consists
of a flattened prominence (shaped like a truncated, inverted
cone), with a sort of trench round it. <A few of these are dis-
posed in two rows converging posteriorly like a widely open
letter V (Fig. 87, cv).

(2.) The fungiform papille are much smaller and more numerous
than the circumvallate ones. Each is somewhat swollen and
rounded at its tip, while it is smaller at its pomt of attach-
ment. These papille (/) are found especially at the sides of
the anterior part of the tongue.

(3.) The conical papille are very numerous and closely set over
the dorsum of the tongue, with their apices directed back-
wards. They are small and simple near the edges and tip of
the tongue, but over the greater part of the dorsal surface they
are much larger and horny in consistency—lhke so many
minute claws—especially towards the middle line. It is the
presence of’ these horny papille which makes the cat’s tongue
so rough and rasp-like.

(4.) The flattened papille are a group of very large, soft, flattened
and pointed papille, placed behind the circumyvallate papille
on the dorsum of the root of the tongue. }

§ 10. Besides the secretion of the small mucous glands, the -

cavity of the mouth is moistened by the product of various kinds of
SALIVARY GLANDS.

The first of these, the parotid, is a branching, or racemose,* gland,
consisting of many lobes held together by their excretory tubules,
blood-vessels, and areolar tissue, and lined throughout with epithelium.
It forms a crescentic mass, with its concavity applied to the under
and anterior aspect of the cartilage at the root of the external ear, its
lower border being prolonged downwards and forwards (Fig. 88, 7).
‘Its duct (called Steno’s or Stenson’s) runs forwards across the mas-
seter muscle, and perforating the buccinator, opens inside the cheek
opposite the sectorial teeth. Two small separate accessory portions

* For a description of the different varieties of glands, see § 8, in the
chapter on the Organs of Respiration and Secretion.

CHAP. vi]: THE CAT’S ALIMENTARY SYSTEM 173

lie opposite each other, one at the front margin of the parotid and
the other at its hinder margin. Another supplementary gland (/),
of an elongated oval shape, lies beside Steno’s duct and opens into its
cavity. It may be distinguished as the facial gland.

The submaxillary gland (sm) is rather smaller than the parotid
and more rounded. It lies behind the angle of the mandible, and
is in contact above with the downward prolongation of the parotid

Fig. 88.—View oF SALIVARY GLANDS AND PARTS ADJACENT.

b. (At angle of mouth) buccal glands jv jv. External jugular vein and (more anteriorly)
b. (Near ear) anterior or accessory parotid. facial vein.
b. (At beginning of throat) the two accessory 1. Hinder accessory parotid.

sub-maxillary glands with the facial vein | n. Facial nerve.

passing between them. sm. Sub-maxillary gland.
d. Duct of parotid gland (Steno’s duct), The duct of this gland is shown running for-
f. Facial gland. | wards above and nearly parallel with the

vein jv, a bran-h from which crosses over it.

before mentioned. Its duct (called Wharton’s duct) runs forwards
beneath the facial vein and opens on the minute salivary papilla
before described as being situated beside the frenum of the tongue.

There are two accessory submaxillary glands which lie side by side
(separated by the facial vein (Fig. 88, jv) immediately adjacent to
the lower and anterior end of the principal submaxillary gland.

Another gland, called sygomatiec, is of rather large size and pyra-
midal shape. It lies beneath the globe of the eye on the orbital
plate of the maxilla and inside the anterior end of the zygoma.
Jt opens in the mouth behind the upper true molar.

i * balk) cas gl Dine Seal | ee) ae

of THE CARY) 0% (omar, VEL

The buccal glands are small glandular aggregations, each agerega-
tion opening by various minute orifices into the mucous membrane
of the mouth. .

The secretion of all these glands constitutes the sativa, which is
a clear, alkaline fluid, consisting mainly of water, but containing
nucleated corpuscles, a peculiar albuminoid substance called salivin,
or ptyalin, and a minute quantity of sulphocyanide of potassium.

This secretion is poured out as it is formed, and its flow is accele-
rated by the contraction of the cheeks and tongue. The secretion
is stimulated by the presence of food in the mouth, and even by the
sight of it.

“The action of this fluid on the food is, first, to soften it and dis-
solve what is soluble, including all its crystalloids. It has no action
on the albuminoid or gelatinoid substances, nor on the fats; but it
tends to convert starch (at the ordinary temperature of the inside of
the mouth) into grape-sugar, thus changing a colloid into a erystal-
loid, and so rendering the starch soluble and capable of undergomg
absorption and assimilation. This action, however, is slow and
feeble in the cat. It is the ptyalin which has this power, which it
seems to exercise simply by the stimulating action of its presence and
contact; for if it 1s precipitated by alcohol, filtered, and then re-
dissolved, it will quickly transform as much as 2,000 times its
weight of starch into sugar.

The food having been sufficiently bitten, it is thrust backwards by
the tongue through the isthmus faucium. While it passes, the velura
palati is raised, and so guards the posterior nares from the intrusion
of the food, and the backward motion of the tongue depressing the epi-
glottis, while the food passes over it, guards the entrance of the
windpipe against the entrance into it of any alimentary matter.

§ 11. Immediately behind the isthmus faucium is a conical cavity,
wider towards its upper part, and more contracted below. This is
the PHARYNXx. It rises up behind the mouth and posterior nares to
the base of the skull, and forms the summit of that canal which
leads down from the mouth to the stomach. It consists of the
pharyngeal muscles already described, with a lining of fascia and
mucous membrane, together with vessels, nerves, and areolar tissue.
It is attached above to the basi-sphenoid and petrosals, and to the
basi-occipital by a fibrous membrane, which passes down between
the recti antici muscles. It is loosely connected behind with the
fascia, investing the pre-vertebral cervical muscles, and laterally.
with the muscles attached to the hyoidean anterior cornu. In
front, 1t is connected with the pterygoids, the hyoid apparatus, and
the larynx.

There are seven openings into the pharynx. ‘These are: the two
posterior nostrils; and external to these, the two Eustachian tubes ;
in front, the mouth ; and below it, the larynx; while inferiorly, the
pharynx opens into (being continuous with) the cesophagus. Its
mucous membrane is beset throughout with simple glands, while
racemose glands are numerous in its upper part.

¥ "
i~ Cyl Bl

CHAP. vI.] THE CAT’S ALIMENTARY SYSTEM. 175

Its epithelium is squamous, except on the hinder surface of the
velum palati, and in the upper (or nasal) region of the pharynx, where
we meet with cILIATED EPITHELIUM. ‘This very remarkable tissue

their name.

These minute processes have the wonderful property of performing
constantly during life, and (in a warm atmosphere) for as much as
forty-eight hours after death, repeated lashing movements; each
cilium bending itself with great rapidity, and then becoming more
slowly straightened. All the adjacent cilia move in the same
direction, thus producing a wave-like motion similar to that of a
field of corn under a strong wind.

The result of these multitudinous and constantly-repeated minute
motions—each repeated about ten times in a second—is to propel
small particles along the ciliated surface of the body.

If a ciliated cell be detached, so as to float freely in some suitable
fluid, then the effect of this action of its cilia is to move about the
cell itself as by a sort of locomotion. Water checks the action of
cilia, but blood will preserve it even for two or three days; such
action still continuing on slips of membrane detached from the
body. No muscular tissue and no nerve has been detected in the
ciliated cells, nor are the actions of the cilia amenable to nervous or
moderate electrical influence. They persist in the membrane which
bears them when this is detached. The cause of their motion is
as yet utterly mexplicable, an ultimate mystery lke that of the
contractile power of muscular tissue.

The FUNCTION OF THE PHARYNX is to direct the food which has
just been pushed, through the isthmus faucium, downwards towards
the stomach by means of successive contractions of its fibres from
above downwards. It becomes more powerfully grasped as it
approaches the cesophagus. This active prehension of aliment
equally takes place when that aliment is fluid, none being allowed
simply to fall down towards the stomach while the walls of the
alimentary tract remain passive.

§ 12. The gullet, or Gsopuacus, is a narrow, cylindrical tube,
beginning at the bottom of the pharynx and extending downwards
through the diaphragm, to terminate (immediately it has passed.
through that partition) in the stomach. It extends along above the
trachea and heart, and beneath the vertebral column and longus colli
muscle, being connected with those parts by lax areolar tissues.

It is, of course, lined with mucous membrane, the surface of
which is covered with squamous epithelium.

The mucous membrane of the upper part of the cesophagus is
7 (when the passage js not distended) in a number of vertical
olds.

The lower end of the cesophagus, for a short distance before

176

THE CAT.

[CHAP. VI.

entering the stomach, has its mucous membrane elevated into
transverse folds, which may be called “ quasi valvule conniventes.”
Outside the mucous membrane is a layer of areolar tissue, and

Fig. 89 —View orf THE CaT’s VISCERA, IN
SITU, THE BODY BEING OPENED ON ITS VENTRAL
ASPECT.

b. Urinary bladder. o. Omentum,
gb. Gall bladder. sp. Spleen.

l. Lung. t. Trachea.
li. Liver. | s. Stomach.
r, Rectum.

outside that is a thick muscular
coat of two layers—the fibres of
each being spirally directed, but
those of the inner layer being
the more horizontal, and those

of the outer layer the more

longitudinal. Those of the outer
layer are very thin, and wanting
every here and there. There is
much striated fibre at the upper
part of the tube.

§ 18. The aBDoMINAL CAVITY
is bounded above by the ver-
tebral column and muscles, la-
terally by the abdominal muscles,
in front by the diaphragm, and
behind by the muscular and mem-
branous partition, which closes
posteriorly the cavity of the
pelvis.

On the middle of the outer
wall of the abdomen there is mm
front a slight irregularity of sur-
face, which is the “navel” or
umbilicus. | |

When the abdomen is opened
by a median antero - posterior
section through its ventral wall,
and by the reflection of the
walls bordering the cut, the fol-
lowing organs come into view.

Immediately behind the dia-
phragm on the right side is seen
the liver (/), with the gall-bladder
protruding from amongst it (gd).
In the middle line, partly beneath
the liver, is the stomach (s), to
the extreme right of which is
the spleen (sp). From the
stomach a flap of membrane,
loaded with more or less fat,
and called the great omentum (0),

extends towards the pelvis, like an apron, and conceals the more

deeply situated viscera.

When this is turned up or removed, a

capacious transverse sacculated viscus may be seen to proceed trans-
versely behind (below) the stomach ; this is the great intestine, behind

RITA VP ore ery a wae ives i SP
uel aaa ;

CHAP. VI.] THE CAT’S ALIMENTARY SYSTEM. 177

which are the multitudinous folds of a narrower tube—the smail
intestine—while superficially, at the posterior end of the abdominal
cavity, the bladder (>) may te seen.

A 02)

Fig. 90.—Tue Cat’s Stomach AND PANCREAS.
A, Left aspect of stomach.

lc. Lesser curvatur2.
ce. CGisophagu;.,

p. Pylovus.

pa P ner as:

ce. Cardiac portion.
bd. Bile du t.

d. Duodenum.

gc. Great :r curvature.

B. Pancreas. _

The pyloric part of the stomach is cut open to
show the pyloric valve.
d. Duodenum,

. Pylorus
dcc. Duetus communis choledochus.
pd. Pancreatic duct.

§ 14. The sromacu is a dilatation of that part of the alimentary °
tube which les immediately behind the diaphragm, rather to the
N

178 a THE CAT. eae an

left. It is somewhat pear-shaped, but sharply bent upon itself. Its
left and much larger end (c), is called the cardiac end, or cardia
(because it is the nearer to the heart), and it is towards this end

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Fig. 91.— VerticaL TRANSVERSE
SECTION OF THE COATS OF A Piq’s
STOMACH, MAGNIFIED 30 DIAMETERS.

a. Gastric glands.

b. pee layer of Hereee ans Fig. 92.—GastRIc GLANDS FROM THE Doc's SToMAcH,
¢€. muo-mucous or areolar coat, HIGHLY MAGNIFIED,
d, Circular muscular layer. Porti hasan fe ie” ol
e. Longitudinal muscular layer. A. Portions of a s'mple tubular '‘ Peptic” gland,
f. Serous coat 1. Neck of the gland.
: 3 2. Fundus,
3. Transv-rse section.

. Peptic cells.
. Central ce ls.
Ends of columnar cells.
B, A gland of more complex shape.
m. Mouth.
n. Neck.
tr. A deep portion cut transversely,

eo sts

that the cesophagus («) opens into the stomach. Its opposite end is
called the pylorus ( p), and is directly continuous with the intestine,
_ the aperture by which the stomach opens into the latter being called
the pyloric orifice. |

Its deeply concave surface between the cesophagus and pylorus is

| CHAP, VI.] THE CAT’S ALIMENTARY SYSTEM, 179

called its “lesser curvature (/c). The opposite very convex side
is called its greater curvature (gc).

Its structure is essentially similar to that of the cesophagus. Its
muscular coat, formed of organic fibres, consists of an outer radiating
layer, directly continuous with the more longitudinal layer of the
cesophagus. Within this is a
layer of circular fibres which -

extends over the whole sto- Z i it i
mach, and is especially thick Z& ww»
at the pylorus, where it forms Sth) £ |

a sphincter which, project-
ing inwards, constitutes (with
areolar tissue and its mucous
lining) what is called the “py-
loric valve” (Fig. 90, B, pv).
Within the second muscular
layer is yet a third set of
obliquely disposed fibres.
Immediately within the
muscular stratum is a layer
of submucous areolar tissue,
which directly supports the
mucous lining of the stomach.
This lining is soft, thick, and
smooth, and is so_ loosely
connected by the areolar layer
with the muscular coat, that
it is thrown into numerous,
regular, undulating effaceable Fig. 93.—TH= INTESTINAL TUBE OF THE CAT, SEEN
folds when the stomach is VENTRALLY, WITH TS FOLDS SOMEWHAT SEPARATED,

: : a Anus. ic, Lesser curvature.
not distended. The inner ac. acum ng colon. p. Pylorus.

5 @, Gisophagus. r. Rectum.
surface of the stomach 1S. Cardia. si. Small intestine.
everywhere beset with small = Ceeum. st. Stomach.

. i . d. Duodenum., tc. Transverse colon.
pits, which are the orifices de. Descend:ng colon, | «. Greater curvature.

of minute close-set gastric and
peptic glands, which may be simple tubes or more or less branching.

At the lower end of the cesophagus the squamous epithelium ceases
and gives place to what is mostly of the columnar kind.

The Frunorion of the stomach is partly mechanical, since by their
contractions, its many muscular fibres rotate its contents, and so
expose all parts in turn to the action of its secreting walls while they
drive it towards the pylorus, and send through that aperture such
portions of it as are sufficiently dissolved or soft. Regurgitation of
food into the cesophagus is prevented by the contraction of the
_ eireular fibres which surround its entrance into the stomach. The
main action of the stomach is digestive through the gastric juice.
This consists of water, with some two per cent. of saline matters, |
a minute quantity of free hydrochloric acid and a little more
than three per cent. of pepsin, a neutral, albuminoid substance.

N 2

180 «THE CAT.

The gastric juice is colourless, or pale yellow, and strongly acid.
Its action on albuminoids and gelatinoids is to change them into an
extremely soluble form called peptone. It has no direct action on
the amylaceous foods (rather arresting the process of converting
starch into sugar) nor on the oleaginous matters. The contents of
the stomach when all the action of that organ has been brought to
bear upon it, is called chyme.

A certain amount of matter is directly absorbed by the vessels of
the walls of the stomach, but this function is far more perfectly per-
formed by the small intestine.

§ 15. The part of the alimentary canal which succeeds the
stomach is the INTESTINE, which is so convoluted as to be about five
times the length of the whole body in the domestic cat, though it is
said to be considerably shorter in the wild cat.

The part of this tube which comes first, is called the small

- Fig. 94.—INTESTINAL VILLI.

A. Section through the small intestine, showing e. Epithelium.
the numerous villi, with their orifices em. External muscular layer.
directed towards the central cavity. im. Internal muscular layer.
B. A single villus, greatly magnified. p. Peritoneal investment.
C. Section of the wall of the intestine, and of a vy. Wessels within a villus.

few villi less magnified than Fig. B.

intestine, and is very much longer, though smaller in calibre, than
the succeeding portion. It is also by far the most convoluted part
of the alimentary tube. It is cylindrical and about three feet eight
inches in length, and of nearly the same diameter throughout. It
is spoken of as consisting of three parts: the duodenum, jejunum,
and ileum. |

The duodenum comes next to the stomach, and describes a rather
wide curve, which embraces the pancreas and receives its duct and also
that from the liver. It lies on the right side of the abdomen. The
jejunum is its continuation thence to the right side, and to it succeeds
the mass of the small intestine which is formed by the c/ewm, and
lies at the posterior and middle part of the abdominal cavity.

we

re
$ 7,
hah

CHAP. VI.] THE CAT’S ALIMENTARY SYSTEM. 181

The inner surface of the small intestine does not form transverse
folds, but is clothed with a velvet-like lining made up of a multitude
of very fine, short, closely-set filaments or vi/ii. These filaments
are prolongations of the corium, invested with columnar epithelium,
and contain blood-vessels, and a central vessel which is not a blood-
vessel, but is called a Jacteal. The lacteals open proximally into
vessels belonging to the same category as they themselves do, and
which le in the submucous areolar tissue.

The lining of the small intestine is also beset with glands. The
most noticeable of these are aggregations of glands, which aggre-
gations go by the name of Peyer’s patches. There are in the small
intestine some six or seven of such patches, more or less narrow and
elongated, especially the one at the posterior end of the ileum, which
is clothed with villi lke other parts of the imtestire. Each patch is
made up of a number of glands, or vesicles, smaller than a pin’s
head, composed of connective tissue, and containing a whitish fluid
with nucleated cells.

Besides these structures, small glands of Lieberkiihn (hike the
simple glands of the stomach) abound between the vill, and there
are other glands called Bruner’s glands, which are branching
structures, most numerous in the duodenum.

The small intestine is composed (1) of an outer or serous coat ;
(2) of two muscular layers; (8) ofan areolar or submucous coat; and ~
(4) of the mucous lining. The serous coat is the peritoneal invest-
ment of the intestine, which is continuous with the two layers of the
mesentery by which it is suspended. Itis wanting in part of the
duodenum. Of the muscular coats, the thinner external layer is
formed of longitudinal fibres. while in the thicker, inner layer they
are arranged circularly at right angles to the long ‘axis of the tube.
The submucous coat is a layer of loose substance of areolar tissue
with fine elastic fibres, amdist which the blood-vessels ramify, and
subdivide before entering the innermost or mucous coat.

The FuncTION of the smal! intestine is, like that of the stomach,
partly mechanical and partly solvent. The successive contractions,
from before backwards, of its muscular walls tend to drive the
contents towards the large intestine. Such motion is, like the
similar movements of the fibres of the stomach, called peristaltic
action. This form of movement is also spoken of as the vermicular
motion of the intestine, and if the animal be suddenly killed, and its
abdomen opened, the peristaltic action will be seen still taking place,
and giving to the intestine an appearance as of so many crawling
worms—whence the term “ vermicular.”’

The process of digestion is further aided, as we shall hereafter see,
by the products of the pancreas and liver, and also somewhat by
the secretions of the crypts of Lieberkiihn’s and of Bruner’s glands.
The former secrete the intestinal juice proper, which is colourless,
and seems to be a form of mucus.

The chyme of the stomach, having been modified by the action of
all these secretions, changes mie what is called chyle, the secretion

182 Ba ie 8 928

of the pancreas, and that of the liver, converting more of what
remains of starch into sugar, dissolving more of what nitrogenous
food has not been dissolved already, and making (by minute division
and mixture) the oleaginous matters into an emulsion.

But one great office of the small intestine is the absorption of
nutriment. This is already begun through the walls of the vessels
of the stomach, but the villi of the intestine carry it on much more
effectively. The most easily dissolved or transmissible fluid passes
into the blood through the walls of the blood-vessels of the
villi, while fatty and albuminoid matters find their way into the
lacteals.

§ 16. At the end of the small intestine, at its junction with the
large, is a blind diverticulum or cul-de-sac, called the cecum.

The LARGE INTESTINE 1s rather more than a quarter of the length
of the small intestine (it is about a foot long), but it is considerably

Fig. 95.—THE CAcum.

A. Seen externally. g. Mesenteric glands.
B. Cut open. 7. Tleum.
ce. Ceecum towards its apex. v. Ilio-czecal valve.

wider and tolerably uniform in width, tapering somewhat to its
hinder end. Instead of being extremely convoluted, it forms but a
single sweep forwards, transversely, and backwards. Its exterior
exhibits a few slightly-indicated transverse depressions. It begins
on the right side of the abdominal cavity, and passes forwards as
what is called the ascending colon ; it passes across to the left, on the
posterior side of the stomach, as the ¢ransverse colon, and then turns
backwards as the descending colon, ending in the terminal portion
of the intestine called the rectum.
The cmcum may be said to be that part of the large mtestine

_ CHAP, VI.] THE CAT’S ALIMENTARY SYSTEM. 183

which projects blindly (whence its name) beyond the point at which
the small intestine opens into the ascending colon. It is a short,
wide, simple, rather conical part, narrowing rapidly to its apex, but
having its terminal portion more or less sharply bent towards the
ileum, and separated off from the rest by a slight constriction—so
that it forms a sort of appendix to the rest of the cecum. This
terminal portion is thick-walled and glandular, being lined by a sort
of Peyer’s patch. The entrance from the ileum into the cecum is
by a circular constriction (with its margin prolonged somewhat into
the czecum) called the ileo-cwcal valve.

There are many glands in the rather thick walls of the cecum,
especially towards its apex.

On each side of the hinder end of the intestine are two large
secreting pouches, or ANAL GLANDS, each of which would contain a
very large pea within its cavity. They are both embraced and .
invested by the external sphincter muscle, and are lined by glandular
mucous membrane. Lach gland opens externally just within the
margin of the anus by a short duct, the inner end of which projects
inwards into the cavity of the gland, of which it is the excretory
channel.

The structure of the large intestine essentially resembles that of
the small. It exhibits irregular internal folds in the descending
colon, and in the rectum; and there are numerous follicles scattered
throughout its whole extent, but its surface is not raised into
processes or villi. There is thus a great contrast between its
interior and the villous internal surface of the small intestine.

The Function of the large intestine is in great part mechanical.
By its contractions its contents are driven onwards to the rectum,
whence they are expelled by the contraction of the rectal walls and
the simultaneous relaxation of the sphincter ani—the expulsive
action being aided by the contraction of the muscular walls of the
abdomen, and the backward pressure of the diaphragm. The power
of absorption of this part of the alimentary tube is much less than
that of the small intestine, as is evidenced by the absence of villi.
Nevertheless it does possess a certain power of absorption, and it
not improbably also serves to extract from the blood, and cast forth
into the intestinal cavity, some substances, the removal of which is
beneficial to the organism.

§ 17. The pancreas (Fig. 90, B) is a large, racemose gland,
composed of, and entirely invested by, peritoneum. It consists of
lobes and lobules of different sizes, connected together by areolar tissue,
vessels and ducts, being in fact like the parotid gland, but somewhat
looser in structure. In shape it is elongated and narrow, and is
indistinctly divisible into two parts. One portion of it, the body,
lies posterior to and above the posterior border of the stomach
(enclosed between the layers of the posterior fold of the great
omentum) on the right; the other and larger part, the head, passes
backwards along the concave margin of the duodenum. It has two
ducts; one of these joins the common bile-duct (from the liver)

184 THE CAT.

before entering the intestine, and the other enters the duodenum,
separately, an inch or more further backwards.*

The function of the pancreas is to secrete a special fluid, the
pancreatic juice, which has in part the nature of saliva, inasmuch as
it tends to convert starch into grape sugar. Unlike saliva, however,
it has a powerful effect on albuminoid and gelatinoid matters, con-

R
Fig. 96.—Cat’s LIVER, VIEWED FROM BEHIND.
R. Right moiety of the liver. | rl@. Larger portion of right central lobe.
ZL. Its left moiety. ru, Right lateral lobe.
c. Caudate lobe. rf. Right lateral fissure.
cf. Cystic notch. hv. Portal vein.
d. Duodenum. s. Spigelian lobe.
gb. Gall bladder. u. Umbilical fissure.
le. Left central lobe. bd. Ductus communis choledochus.
Wl. Left lateral lobe. o. Its opening into the duodenum.
lf. Left lateral fissure. . Pylorus.

re. Smaller portion of righ central lobe.

verting them, as the gastric juice does, into peptones. Besides
these actions it also emulsifies fats.

§ 18. The Liver is the largest gland in the body, and lies mainly
to the right, immediately behind the diaphragm, between it and the
stomach, and protected by the cartilages of the ribs. Certain large

* Jn some cases a duct has been seen | serving to retain some of the secretion of
to lead, from the point of junction of the | the pancreas as the gall-bladder retains
ducts above mentioned, to a small sac, | that of the liver.

_ [CHAP, VI.

3 SSRs

‘CHAP. VI.] THE CAT’S ALIMENTARY SYSTEM. 185

blood-vessels (the aorta and vena cava) are interposed -between it
and the bodies of the vertebre. :

It is a solid organ, thick dorsally, and thinning out below; of a
reddish-brown colour, smooth and convex towards the diaphragm,
but concave and uneven on its opposite surface. It is divisible into
certain parts, or /obes, which are defined and marked off, partly by
grooves and notches in its substance, partly by ligaments and blood-
vessels connected with it.

The liver is divided into two unequal lateral halves by a mem-
branous ligament (the broad or falciform ligament), which passes to
it from the adjacent surface of the diaphragm, and which consists of
two folds of peritoneum, as will be hereafter explained. This
ligament is attached to the liver in a line running from its dorsal
margin to its ventral border; and the part on the right side of it is
the larger.

When the posterior surface of the liver isin view, a deep notch (x)
and groove may be observed opposite to, and corresponding with,
the attachment of the broad ligament. This groove is called the
longitudinal fissure, and it lodges a fibrous cord called the round
ligament. The anterior part of this cord (which passes upwards to
the liver from the navel) is the remnant of a structure temporarily
developed in the very young condition—the umbilical vein— while
the posterior part of the cord (which joms the vena cava) is the
remnant of another primitive vessel—the ductus venosus.

On this account the ventral part of the groove is called the
umbilical fissure (uw), while its posterior part is named the fissure of
the ductus venosus. ‘This fissure then divides the liver into two
unequal lobes on its hinder surface, and each of these is again
subdivided by other fissures. Thus a small, prominent, undivided,
somewhat pyramidal lobe (called Spigelian) is placed almost medially
at the dorsal border of the liver (s), its apex extending outwards
on the hinder surface of the left lateral lobe (2/). It is bounded on
the right by a short deep groove called the fissure of the vena cava,
because it is traversed by that vessel. The Spigelian lobe is bounded
ventrally by the transverse or portal fissure which runs, almost at
right angles, into the longitudinal fissure. It is into this transverse
fissure that the portal vein, the hepatic artery and the great nerves
enter, and it is from it that the main bile ducts proceed to convey
away the biliary secretions.

The portal fissure runs to the right, beyond the limits of the
Spigelian lobe. That part of the substance of the liver which is
situate on the dorsal side of this outer part of the portal fissure, is
called the caudate lobe (c). It is a moderate-sized, ridge-like lobe,
which proceeds from the base of the Spigelian lobe to and along the
hinder surface of the right lateral lobe (r/!), and is more or less
limited behind by the vena cava.

The right lateral lobe 1s small and separated from a much larger
lobe, the right central (ri”)—which lies next it but nearer the middle
line—by a deep fissure called the right lateral fissure (rf). The

186 THE OAT, [onary

posterior surface of the right central lobe is marked by a depression in
which lies a pear-shaped bag—completely invested by peritoneum—
called the GALL-BLADDER, which has its blind end (or fundus)
directed downwards near (gb), the ventral margin of the liver. The
notch at which its fundus is situated, and the depression in which
the bladder hes, is called the cystic fissure (ef). The fundus of
the gall-bladder is occasionally buried in the liver’s substance, and
appears, through a cleft, in its convex surface. The part of the
right central lobe which lies to the left of the gall-bladder (ve) is
itself bounded on the left by the umbilical fissure already described.

SS an
y = >/|\ :
Sea ee CON

———=
a

=

ZEB

ZEA

MUM
3 Y ji) ae Ly L$}
hy YY GH
Wy p

, Cif ay or
yy Lif RS Terk

Fig. 97.—SEcTION OF A PORTION OF THE LIVER (OF THE PIG), PASSING LONGITUDINALLY
THROUGH A CONSIDERABLE HEPATIC VEIN, ENLARGED ABOUT FIVE DIAMETERS.

H. Hepatic venous trunk, against which the i. Mouth of the intra-lobular veins, opening into

sides of the lobules are applied. the sub-lobular veins.

h,h,h. Three sub-lobular hepatic veins, on i’. Intra-lobular veins, shown passing up the
which the bases of the lobules rest, and centre of some divided lobules.
through the coat. of which they are seen as | c,c. Walls of the hepatic venous canal, with the
polygonal fissures. polygonal bases of the lobules.

Beyond it lies a very small lobe, the Jefé central lobe, which is
separated from a very large lobe—the /eft lateral lobe (l1)—by a
deep fissure called the /eft lateral fissure (Uf). |

The bile, or hepatic, ducts issue from the lobes of the liver and
the portal fissure, and join the duct which comes-from the gall-
bladder. The latter duct is called the cystic duct, and the common
duct formed by its union with the hepatic ducts, is termed the
ductus communis choledochus (bd). This opens into the duodenum at
about en inch and a half from the pylorus—after beimg joined by
one of the pancreatic ducts.

CHAP. VI.] THE CAT’S ALIMENTARY SYSTEM. 187

pearance, and careful inspection

The cystic duct is convoluted, making about four turns, held

together by areolar tissue.

The several hepatic ducts correspond with the different lobes
of the liver, and are formed by the union of small ducts arising
from the several liver (or hepatic) lobes. The ductus communis
choledochus sensibly enlarges
as it traverses the coats of the
duodenum.

The MINUTE sTRUCTURE of
the liver consists of a com-
plex arrangement of microscopic
blood-vessels and cells, con-
nected by areolar tissue, as
follows :—

When the substance of the
liver is cut across, its solid sub-
stance presents a mottled ap-

shows that itis made up of a
number of polygonal masses,
which are called dobu/es. These
lobules are seen to be arranged.
around a number of canals pro-
ceeding in two directions. One
set of canals diverge from the
portal fissure, and these are ; : x

called portal canals. ‘The other Hhiae, eee Mbiioear Nines Eras
set of canals converge to the ARTE, Ax» Hrranie Duct, ynow’ ms Fro.
inferior eral Ee and these P. Branch of vena porte, situated in a portal
are called hepatic veins. Now, canal, formed amo: gst the hepatic lobules

j ‘ of the liver.
as will be hereafter seen, the pp. Larger branches of the portal vein, giving

blood is of two kinds. arterial off smaller ones (i i), named inter-lobular
. z : veins ; there are also seen within the larg:
and venous, and is respectively portal vein numeious orifices of i ter-

conveyed (except as regards the , Der teste! ari Paanaae

lungs, ) by vessels called arteries At 2 ane Soul wall has ben par.ially
and veins, accordingly as they reuoved.

carry the one or the other kind

of blood. No less than three sets of vessels ramify in the substance of
theliver, two sets conveying blood into, and one set (the hepatic veins)
conveying blood out of it. Of the two sets of vessels conveying blood
into it, one is arterial, the hepatic artery; the other is venous, the portal
vein. These ramify in the portal canals along with branches of the
hepatic ducts, the whole three sets of ramifications being surrounded

and supported by areolar tissue, which 1s contmuous with a fibrous

membrane which invests the external surface of the liver generally.

The several branches of the portal ven are much larger than the
accompanying hepatic ducts, and these are somewhat larger than
the arteries. The arteries convey nutriment to the framework
of the liver, its branches ending in the walls of the ducts, blood-

7

188 THE CAT.

vessels, and in the areolar tissue. The portal veins end by minute
vessels, which surround and penetrate the lobules of the liver
(whence they are called interlobular veins), while the hepatic ducts
end in most delicate canals, which pass amongst the hepatic, or
liver, cells, which make up the substance of the lobules between
its multitudinous vessels.

The blood bemg thus conveyed to the circumference of each
lobule, proceeds thence to its centre, where it collects in the com-
mencements (ultimate twigs) of the hepatic vein which, from the
fact that they thus take origin, are called intra-lobular veins.

The diver cells (or hepatic cells) form the secreting substance of
the liver, and are spheroidal or polygonal nucleated bodies of a
yellowish colour, contamming granules and fatty matter besides the
nuclei. They vary from =}, to +s4> of an inch in diameter.

The runcrion of the liver consists in the secretion of bile,
though the full meaning and effect of its activity is not by any
means entirely understood.

B11# is au alkaline, greenish-yellow, viscid, bitter fluid, containing
from 8 to 16 per cent. of solid matter, consisting principally of a
compound nitrogenous substance termed bitin. It also contains a
non-nitrogenous substance called cholesterin, with certain salts and
peculiar colouring matters (biliverdin and bilifulvin) containing iron.
These colouring and other substances are formed by the cells of the
liver, and do not pre-exist in the blood.

Another substance which is found accumulated in the liver after
death, does not escape by the hepatic ducts. This is g/ycogen or
animal starch. |

The rapidity with which bile is secreted varies according to
circumstances, increasing during the process of digestion.

The bile does not all pass directly mto the intestine, but part of
it regurgitates along the cystic duct into the gall-bladder, where it
may remain for a certain time, and where it becomes somewhat
thickened.

The action of the bile on the food is, in the first place, to neutra- -

for, ee

lize the acid of the chyme, and secondly, to aid in emulsifying ©

fatty matters.

But in addition to its effect on food, the secretion, of bile is
important as a mode of eliminating from the body substances, the
removal of which is necessary to healthy life. The colouring
matters of the bile are always entirely excreted, but other of its
constituents appear to be decomposed in the large intestine, their
nutritious matter being re-absorbed and their refuse driven on as
excretin, stercorin and some other substances.

Yet other functions are performed by the bile; namely, that of
exciting, directly or indirectly, the action of the intestinal mucous
membrane and also the peristaltic action.

It is also said to have an anti-putrescent action on the food,
putrefaction taking place in the alimentary canal in the absence
of bile. ie

CHAP. VI.] THE CAT’S ALIMENTARY SYSTEM. 189

§ 19. The PEerRrronEum is the large closed sac, formed of very
delicate membrane, which both lines the abdominal cavity and coats
its contents. It is one of a class of membranes called “serous,”
from the nature of the colourless fluid with which their surfaces
are moistened, and which is more or less like the ‘‘ serum” of the
blood. Part of the membrane is applied to the inner surface of
the walls of the abdominal cavity, and this is called its parietul
portion, but it is every here and there reflected from the walls
over the viscera contaimed within them, and such reflected parts
are called its visceral or reflected portion. Thus the viscera nowhere
enter into the real cavity of the peritoneal sac, while their move-
ments can take place without friction because the moist imner
surfaces of the peritoneum are everywhere juxtaposed, however
complex and complete may be wrappings round which the viscera
receive from the inflexions of this highly complex sac.

The membrane is formed of connective tissue, which is lined by a
layer of squamous epithelial cells. ;

The layer of epitheltum thus lining a serous cavity is called
endothelium. The peritoneal serous membrane is attached to the
parts to which it is apphed by fibres of more or less loose areolar
tissue. |

The FORM OR ARRANGEMENT of the peritoneum is exceedingly
complex, owing to the contorted and unsymmetrical arrangement of
the viscera which it invests, and which fill the abdominal cavity
In development, as will be hereafter seen, the alimentary canal is
primitively an exceedingly simple tube traversing the abdominal
cavity from before backwards. The peritoneum lining the ventral
surface of the abdomen is continued upwards along its sides, nearly
to the middle line, whence each lateral layer is reflected ventrally, to
embrace closely each side of the alimentary tube, and to meet the
reflection of the lateral layer of the other side, upon the ventral
surface of the alimentary tube. Thus this tube is enclosed and
slung 10 a fold of membrane, and really lies (as before said) external
to the peritoneal cavity; though the two reflected folds (between the
alimentary tube and the back of the abdominal cavity) become so
closely applied together as to seem to form but one membrane.

As development proceeds, the alimentary tube becomes differen-
tiated. into regions of very different capacities; while, at the same
time, it becomes enormously elongated, contorted, and unsymmetri-
cally disposed, and so the membrane which holds it enclosed and
attaches it to the dorsal wall of the abdominal cavity, becomes
necessarily drawn out and folded in a very complex manner; and
this complexity is increased by the fact that layers of the membrane
which are primitively distinct grow together with contact, till they
appear to be but one membrane.

' Folds of the peritoneum which retain the primitive condition
and still suspend portions of the alimentary canal from the mid-
dorsal region of the abdominal cavity, are termed mesenteries ; folds
of peritoneum which pass from one viscus to another, are called

. as
190 THE CAT, (CHP age

omenta ; and folds which pass from the abdominal wall to viscera
which do not form parts of the alimentary tube itself, are spoken of
as ligaments.

The peritoneum forms a truly cLosEp sac in the male, but in the
female it has two small openings, which indirectly communicate with
the external surface of the body. These openings are the mouths
of the “ Fallopian tubes.”

Of the MESENTERIEs, the mesentery par excellence is that which
connects the small intestine with the dorsal abdominal wall, and
conveys vessels to it. It contains numerous mesenteric glands (to
be noticed hereafter in connexion with the lymphatic system) and
vessels. Its vertebral border is very short, but its intestinal border
is of course drawn out nearly to the length of the small intestine.
Other folds attach the large intestine to the back of the abdominal
wall, and are respectively called the meso-colon and meso-rectum.

The omeyra are threa in number, and the first and largest
of these, the great or gastro-colic omentum, is really a modified
mesentery, being an enormous extension of that membrane which
primitively connected the stomach with the body-wall, and which is
produced and folded on itself so as to form’ a great sac, constituting
that apron-like fold which was before spoken of as covering the
intestines when the abdominal cavity is laid open in front.

Anteriorly, the great omentum is attached to the stomach along
its greater curvature; posteriorly, it is attached to the. dorsal
surface of the abdominal wall. Thus, this great omental sac con-
sists really of four layers.

That it must do so is plain, since every mesentery consists of two
layers (which hold between them the viscus they suspend), and, the
great omentun being a pouch formed by the bulging out of a.
mesentery in a sac-like manner, each wall of the sac (being a part
of a mesentery) must consist of two layers.

The second, gastro-hepatic, or lesser omentum, passes backwards
from the hinder surface of the liver to the pyloric part of the
stomach, and the beginning of the duodenum. Its two folds extend
from the two sides of the portal fissure, and have between them the

ortal vein and hepatic artery, as well as the gall-duct.

The third, or gastro-splenic omentum, proceeds from the cardiac
region of the stomach to the hilus of the spleen. There it divides,
one layer passing all round the outer surface of the spleen, and
returning to the other side of the hilus, whence the two layers pro-
ceed side by side to the diaphragm; forming what might be called
a mesentery of the spleen. Between these layers the blood-vessels
proceed to the spleen and to the stomach, showing that the gastro-
splenic omentum is the remains of the proximal part of what was.
originally the gastric mesentery.

By the folding of the peritoneum upon itself with the development
of the viscera, the edge of the gastro-hepatic omentum is brought

so near the posterior abdominal wall that but a small space is left
between. This space is called the foramen of Winslow, and the

CHAP. VI. | THE CAT’S ALIMENTARY SYSTEM. 191

inner surface of the great omental sac is continuous with its
margins ; and thus, through it alone, is a communication established
between the cavity of that sac and the general abdominal peritoneal
cavity.

The ligaments formed by folds of peritoneum, except those of the
uterus (which will be noticed with the generative organs), are also
three in number, all proceeding to the liver.

The first of these, the falciform ligament of the liver, is a double
layer of peritoneum proceeding backwards from the hinder surface
of the diaphragm and the abdominal wall down to the navel, to the
anterior surface of the liver, where its line of attachment, as we have
seen, divides that viscus into its right and left halves. From that
line of attachment the two layers of the ligament separate and pro-
ceed right and left to invest the surface of the liver.

In the posterior, ventral free margin of the ligament (between the
ventral abdominal wall and the liver) is a fibrous cord called the
round ligament, and which is the relic of a fcetal structure. It
extends from the navel to the longitudinal fissure on the hinder
_ surface of the liver, as before described. The third ligament con-
nects the dorsal border of the liver with the diaphragm.

Thus, the general INVESTING ARRANGEMENT of the peritoneum
lines the interior abdominal wall, and invests the viscera, as
follows :—It invests the liver, except where reflected from it;
the hinder surface of the gall-bladder; the stomach (except the
narrow line of attachment at each curvature) ; the spleen, except at
its hilus; the ventral surface only of the pancreas and kidneys, and
the anterior surface of the bladder. Almost all the small intestine,
and more or less of the large intestine and rectum, are completely
invested by peritoneum. Thus, these viscera are described as having
a fourth or’ serous cvat in addition to the muscular, areolar, and.
mucous coats already described.

EPSP LO A Dike Aa it
7 ain | re

CHAPTER VIL.

THE CAT’S ORGANS OF CIRCULATION.

§ 1. Tue organs of circulation, or the circulating or vascular *
system, comprises all that great system of tubes (of very various
sizes) which have already been referred to, as arteries and veins,
and all the various channels, or vessels, by which the nutritive fluid
of the body—the blood—is conveyed to and from every part of the —
ceat’s frame.

That it should be so conveyed is a manifest necessity of life, for
since the process of nutrition takes place in the very innermost
substance of the body (as has been already pointed out), there must
be channels by which every part of the body may be supplied with
its needed nutriment. Such nutriment is to be found in the blood,
which has the power of repairing the waste of the tissues and sup-
plying the materials for assimilation and growth, but which cannot
obviously carry this power into effect except by moving from space
to space throughout the body—without, that is, being propelled by
“organs of circulation,’ and without exuding from the ultimate
ramifications of such organs, to reach the very parenchyma itself.

But we shall see in the next chapter that processes of gaseous
interchange, “respiration,” and of the elimination of waste and other
products, ‘‘secretion,” also really take place in the innermost paren-
chyma, and not on the surfaces of the inner lining of the tubes of
the various organs and internal cavities. Yet all that is so given
out or exchanged must (if respiration and secretion are to be effected)
find its way to such surfaces, and in order that it may be able so to
do, we also require the aid of the circulating system. But the blood,
in and by the very act of nourishing the various organs, must part
with its nutritive material, and this, therefore, requires to be re-
plenished if life is to be maintained. The needful gaseous matters
are obtained by it in respiration; but the other matters have to be
gathered from materials prepared for it within the alimentary canal.
These materials, we have already seen, in part pass directly into the
blood-vessels which surround that canal, and in part into the vessels

* A condition of vascularity (i.ce., the | been attributed to certain tissues, such
presence of blood-vessels) has already | ¢.g. as the dermis, intestinal villi, &e.

cHap. vi] THE CAT’S ORGANS OF CIRCULATION. 193

-ealled “lacteals,” which are to be found in the intestinal villi. These

lacteals we shall see open into tubes called “ /ymphatic vessels,” or
“lymphatics,” and which vessels ultimately open and pour their
contents into certain veins, after traversmg—here and there in their
course—certain bodies called lymphatic glands. The lymphatics do
not contain “ blood,” but a colourless fluid called “‘/ymph,” consisting
in part of the nutritious material absorbed from the walls of the ali-
mentary canal, and partly of such of the colourless matter of the blood
as has exuded from the vessels in order to effect nutrition, but
has not been made use of. It is therefore taken up again by the
lymphatics to be by them reconveyed to the blood-vessels. We
have thus two nutritive fluids—“ blood” and “ lymph ”’—enclosed
in two systems of vessels, “ blood-vessels ”’ and ‘ lymphatics.”

The blvod-vessels form a system of tubes completely closed, save
at the apertures where the lymphatics open in them. In part, the
vessels are of microscopic dimensions, but in one place the system is
dilated into a large, complexly formed, rhythmically contractile
organ—-the heart.

The heart may be considered as the central portion of the circu-
lating system, all the other channels being subsidiary to it. These
latter may be divided into three categories: (A) the vessels taking
blood from the heart—which vessels are called arteries; (B) the
vessels taking blood towards the heart—which are the veins; and
(C) certain minute tubes which convey the blood to the tissues, and
intervene between and connect the ends of the arteries and vems—
the capillaries.

It may be well before proceeding to examine in detail these
various parts, and those other parts which compose the lymphatic
system, to consider the two fluids which these two sets of organs
respectively convey.

§ 2. The BLoop 1s a thickish alkaline fluid, somewhat heavier than
water, which has a saltish taste and a faint odour, and is of a more
or less scarlet or more or less purple red, according to circumstances.
It consists mainly (more than 75 per cent.) of water, with a con-
siderable quantity (12 to 14 per cent.) of an albuminoid substance
termed hemoglobin, the rest consisting of albumen and other protein
matters and salts. A nitrogenous substance called fibrm may be
obtained from fresh-drawn blood by whipping it with slender rods—
the fibrin then adhering to the rods in the form of a soft, whitish,
stringy matter. Though apparently homogeneous to the naked eye,
blood spontaneously separates (when drawn from the body and
allowed to stand undisturbed) into different parts—one fiuid, the
other more or less solid.

This process of solidification is called coacuLaTion,* and it occurs
thus: the fresh-drawn blood forms itself into a jelly-like mass,

* Fibrin, as such, does not exist in | albuminous substances, which exist side
the blood. It is supposed by some to be | by side in the blood while alive.
formed by the chemical union of two
0

194 THE CAT.

but soon drops of clear fluid exude from it, and collect to form what
is called the serwm, while the solid mass left behind is the e/oé.

Sometimes the clot is of a lighter colour above than below, show-
ing that the clot itself consists of two elements, as is indeed the case.
The clear part of it, is that substance which it has been said may be
obtained by whipping, namely, “fibrin; ” while the red part, when
examined by the microscope, is found to owe its colour to the presence
of an immense multitude of minute coloured discoidal bodies called
corpuscles,* and which may be seen to float freely about in quite
fresh blood, or in blood which (from the addition of salt or some
other suitable matter, or from being kept at a low temperature) is
prevented from coagulating.

Thus fresh blood is found to consist of corpuscles floating in a
fluid—the liquor sanguinis—which fluid yields both fibrin and serum.
When coagulation takes place the fluid of the blood separates into
two parts. One, the fibrin, solidifies, and, by entangling the cor-
puscles amongst its filaments, forms the clot, while the remaining
part of the liquor sanguinis escapes as the serum.

The coloured, or RED coRPUSCLES are disc-like structures, only about
the +255 of an inch in diameter, or even less. They are circular in
outline, and each flattened side is concave and medianly depressed,
so that each disc is thinnest from side to side in its middle, with a
somewhat enlarged circumference.

These corpuscles have no limiting membrane, though their ex-
terior is somewhat denser than their interior, and they are soft and
elastic. They exhibit no interior structure and no nucleus, but they
consist of hemoglobin containing iron. Each is of a yellowish red
colour, but by their excessive multitude they produce the deep red
colour of the blood. In blood drawn from the body they tend to run
together in strings, applying themselves face to face like piles of
coins.

Besides the red corpuscles, the blood also contains a variable
quantity of WHITE corPUSCLES. These are much essnumerous than .
-are the red, there being only some two or three white to a thousand
of the red, though the proportion increases after eating. They are

also rather larger than are the red corpuscles; but their distinguish-
ing characteristics (besides colourlessness) are their possession of
a nucleus in their granular contents, and their spheroidal or irregular
form. The white corpuscles, in fact, have the power of spontaneously,
so to speak, altering their shape by protruding portions of their
substance in an irregular manner and in all directions. This change
of form is however effected very slowly, so that careful observation
for several minutes, or several observations at intervals of about a
minute, are needed to detect it. These movements are sometimes
termed ameboid, from their resemblance to the movements exhibited
by some of the lowest animals.

The blood, while within the body, during life, is really a TissuE,

* Which make up about a third of the volume of the mass of the blood.

cHAP. vi.] THE CATS ORGANS OF CIRCULATION. 195

and as fully shares in the body’s vitalsty as do the other tissues.
The corpuscles may be regarded as answering to those nucleated
cells which we have found to exist in the other tissues, while the
liquor sanguinis corresponds with the matrix of such other tissues—
the matrix being fluid in the blood tissue, instead of being calcareous,
as is bone, chendrified as in cartilage, or more or less fibrous as in
connective tissue.

As has been already mentioned, the blood may appear either
scarlet or purple, and from the relation of blood so diversely coloured
to the parts which contain it, these two kinds of blood are spoken of

Fig. 99.—Btoop CoRPUSCLES OF MAN AND OF THE CAT, SIMILARLY ENLARGED,

A. Blood corpuscles of man. e. A white corpuscle treated with acetic acid
B. Blood corpuscles of the cat. and showing its nucleus.

a, Red corpuscles. f. One slightly altered.

b. A single one seen edgeways. g. A white corpuscle in the act of changing its
c. A few grouped in a pile. shape by amceebiform movement.

d. Normal white corpuscles.

respectively as ARTERIAL and vENous. The scarlet or arterial
blood is found (1) in the arteries or vessels which carry blood from
the heart as well as (2) in vessels which proceed from the lungs.
The purple or venous blood is found (1) in the veins generally, (2)
in certain vessels ramifying in the liver, and (8) in others proceeding
to the lungs. |

The difference between arterial and venous blood depends upon
arterial blood containing a greater quantity of oxygen, and venous
blood possessing more carbonic acid. Blood contains a large amount
of gas (about half its own volume), principally the gases just
a but also some nitrogen, introduced withmm it probably by the

ungs.

§ 3. LympH is a slightly alkaline, clear, colourless, or pale yellow
fluid, containing only 5 per cent., by weight, of solid constituents.
It is thinner than blood, but, like it, contains albumen, some salts,
and some extractive matters. It is devoid of red corpuscles,
being in fact like the liquor sanguinis, and being, like it, capable of
coagulation. It isin fact (as before said) made of the exudation of
the liquor sanguinis mixed with fluid absorbed from the alimentary
canal. Its likeness to blood is the more complete, since it contains
numerous colourless corpuscles, ‘‘ /ymph corpuscles,’ and which are

quite like the colourless corpuscles of the blood.
02

196 THE CAT. [CHAP. VIL

The blood and lymph are contained and conveyed on their course
by the various sets of vessels and other parts already enumerated,
about each of which there is much to be said.

§ 4. The arreErtés are strong and very elastic tubes, so that
when empty they remain open and do not collapse. They are
lined internally with an epithelial layer, external to which is a layer
of elastic tissue. External to this again is a stratum of organic
muscular fibres, arranged in bundles placed mainly at right angles
to the course of the artery and tending to surround it, though some
fibres are longitudinal and others oblique in direction. External
again to the muscular layer 1s a layer of elastic tissue (and elastic
fibres are also more or less mixed with the muscular fibres), and
finally the whole is enclosed by a layer of connective tissue. .

In the smallest arteries the elastic coat is absent, while the
muscular coat is relatively more developed than in the larger
arteries. Arteries, generally, run deeply in well protected situations.
As they advance they divide and subdivide into smaller and smaller
branches. Different branches of the same, or of different trunks,
may unite together, and such unions are termed anastomoses.
Arteries generally run in a rather straight manner, but they may
pursue a very tortuous course. Sometimes an artery may suddenly
break up into a number of small anastomosing branches, which
reunite to form a single vessel. Such a network 1s called a rete
mirabile. 'The presence of the muscular coat enables the arteries to
diminish their capacity by contracting their muscular fibres, or, by
relaxing them, to enlarge it, since these fibres are contracted toa
certain moderate amount in the normal state of the arteries.* The
walls of the arteries are themselves supplied and nourished by minute
vessels termed vasa vasorum.

§ 5. The vers are weak and thin-walled tubes, much less elastic
than the arteries—collapsing when emptied. They aré lined in-
ternally with an epithelial layer, external to which is elastic tissue
and a stratum of organic muscular fibres invested externally by
connective tissue. 9
, In some veins this muscular layer is absent, while it 1s excep-
tionally well developed in a large vessel going to the liver, the
portal vein, and in that coming from the spleen. The veins ramity
through the body, as do the arteries, but are more numerous and
have greater capacity. They are arranged in a superficial and
deep set—the deeper veins accompanying the corresponding arteries,
as what are called venw comites. Veins anastomose together more
frequently than do arteries; their walls, like those of arteries, are
supplied with vasa vasorum.

The veins are generally furnished with certain structures not
found in the arteries, namely, valves. These are crescentic folds of
membrane, so arranged that in each the semilunar edge of the fold

* These muscles are under the control | the so-called vaso-motor and vaso-dilator
of special parts of the nervous system— ! nerves. .

cHAP. vil.] THE CAT'S ORGANS OF CIRCULATION. 197

is continuous with the inner wall of the vein, while the straight
edge of the fold hangs freely inwards into the cavity of the vein.
Usually two such folds, or v.lves, are placed one opposite to the
other, and when these hang down their free edges meet and so close
altogether the passage through the vein. Any pressure exercised
from that side towards which the concavities of the valves lok,
tends of course to separate them from the wall of the vein and so
close the passage through it, while pressure from the opposite side
tends to press the valves against the walls of the veins, and so to

Fig. 100.—DIAGRAMS, SHOWING VALVES OF VEINS.

A. Part of a vein cut longitudinally and opened ‘ edges of the valves in their closed state.
out, showing two pairs of valves. On The slightest pressure applied from below
account of the vessel being thus opened would cause these valves to open; but
out, each pair of valves appear as if placed pressure from above would only press them
side by side, instead of one opposite the together more tightly.
other. C. Portion of a distended vein, seen externally

B. Longitudinal section of a vein, showing the and exhibiting a swelling in the Situation of
two valves of a single pair in their natural a pair of valves.

position, and showing the a) position of the

open the passage to its full width. Now these valves are so placed
that their convexities look towards the capillary vessels, from which
the vein which contains them springs, while their concavities look
towards that point (generally the heart) towards which the stream
of venous blood is flowing. Thus the action of these valves is to
help on that stream along its course, since they readily yield and
allow it to flow along its appointed direction, whilst they descend,
unite, and bar the passage, when temporary lccal pressure or any
other cause tends to drive the blood in the reverse direction to that
which it ordinarily pursues.

There are no valves in the vene cave, the portal and hepatic
veins, those of the kidneys and uterus, nor in the pulmonary veins
and those of the interior of the skull and vertebral column.

§ 6. The veins and arteries are, as has been said, connected
together by the intervention of the sanguineous CAPILLARIES. These
are microscopic vessels and form a network in most of the tissues—a
network so rich that sometimes the interspaces between them are not
wider than are the capillaries themselves. Their walls are extremely

198 THE CAT. (CHAP. vi,

delicate, and readily allow their contents to exude. It is only thus

' the unvascular tissues—such as dentine—are nourished. Besides

the teeth, capillaries are absent from cartilage and from epidermal
and epithelial structures.

The white corpuscles. pass readily through the walls of the minute
capillaries, but the red corpuscles do so but rarely. Both veins and
arteries merge insensibly into capillary vessels, and a constant stream
of blood passes from the latter to the former through them.

The smaller capillaries consist of a delicate membrane lined with
endothelium; the larger ones have also a layer of organic muscular
fibres.

§ ‘7. The Lympuarics are present nearly everywhere in the body.
They are smaller but more numerous than the veins, and anastomose
more frequently. In some situations, as in the brain, they surround
and enclose the blood-vessels, and they seem to take origin (as
will be more fully pointed out when they are described,) in the
mere interspaces between the elemental parts of different organs.
When the lymphatics have advanced somewhat from their origin
they possess three coats: namely, an imner one, of longitudinally
disposed fibres of elastic tissue, lined with endothelium; a middle
one, of circular, organic, muscular fibres, mixed with elastic fibres ;
and an outer coat of connective tissuae—also with a few elastic
fibres.

Like the blood-vessels, the lymphatics have vasa vasorum in their
walls. ,

Valves, like those of the veins, exist in the lymphatics and
lacteals. They are distributed at shorter intervals, and their
structure is sometimes less regular. |

The lymphatics and lacteals in their course pass (as has been
already observed,) through certain structures called LYMPHATIC GLANDS.
These are rounded bodies, consisting mainly of a mass of lymph
corpuscles enclosed in a firm envelope and richly supplied with
blood-vessels and lymphatics. Each gland is coated externally by
connective tissue (which may contain muscular fibre cells,) and
which completely invests it, save where the vessels enter and leave
it. This fibrous coat sends in processes, called trabeculae, into
the substance of the gland, which substance—the proper glandular
substance—consists of a mass of lymph corpuscles, with connective
tissue. The outer part of this mass (the cortical substance,) is
generally enclosed in a number of chambers, a/veoli, while the more
central part (the medullary substance) is enclosed—lhke so many
cords—between the meshes of the trabeculae. In these chambers
thus containing masses of lymph corpuscles, a certain space is left,
called the /ymph sinus or lymph-channel, which -space is crossed
only by fibres of connective tissue, with their nuclei, and is traversed
by the lymph stream. The lymphatics which come to the gland—
the afferent lymphatics—lose all their coats as they enter, save the
epithelial lining, which is continued on over the trabecule. Simi-
larly the lymphatics which leave the gland—the efferent lymphatics

OHAP. vil.}] THE CAT’S ORGANS OF CIRCULATION. 199

_—begin to arise from the epithelial investment of the trabeculae, and
only acquire their coats, other than epithelial, as they leave the
gland. Thus a lymphatic gland is, as it were, an expanded
sinus into which a number of lymphatics merge, and wherein it
appears a multiplication of lymph corpuscles takes place, probably
by spontaneous division—the parts of the corpuscles thus spontane-
ously dividing growing up into whole corpuscles.

Each gland is richly supplied with blood-vessels, and the lymph

| <s =

a :

US

Fig. 101.—DIAGRAMMATIC SECTION OF A LYMPHATIC GLAND.

al. Afferent lymphatics. substance—such spots being trabecule cut

el. Efferent lymphatics. across. At the upperright-hand part of the
c. Cortical substance figure the lymph corpuscles, /h, are repre-
m. Medullary substance. sented in three alveoli and in the adjacent
ls. Lymph sinus, medullary part. Elsewhere they are not
c. Fibrous coat. represented. A whit: band is to be seen .
tr. Trabecule. around all the alveoli, nd also round each ,
th. Lymph corpuscles. of the cut-across trabecule in medullary
The letter C is placed in one of the alveoli. The substance. The band is the lymph sinus,
trabecule are represented by a dark shade, a'd the irregular lines which cross it at
and are seen extending inwards from the short intervals are the connective tissue
fibrous coat and as spots in the medullary fibres and nuclei.

which leaves it is not only richer in colourless corpuscles than is
that which comes to it, but also in fibrin. These glands are
conspicuous in the neck, the axilla, and the thigh, and speedily
enlarge in size when any part of the body near them becomes the
seat of pain. : |

§ 8. The nxart is a thick muscular and hollow organ, from the
anterior, broad part of which great blood-vessels originate.

It is enclosed in a sac of fibrous tissue lined with epithelium,

called the pericardium. It consists of four chambers, two of which

200

THE CAT.

are called auricles, and the other two, ventricles—one of each on

each side.

The auricle and ventricle of the right side are com-
pletely divided off from those of the left side.

The auricles open.

ito the ventricles by valvular apertures, and valves guard the

openings of the great vessels.

Such being a summary of its main characters, its various parts

need oa Maer ige in detail.

The heart of the cat les on the ventral side of the body, within

_ [CHAP. VII. a i

Fig. 102.—Cat’s HEART CUT OPEN.

A. The left side.

B. The right side.

a. Style passing up through inferior vena cava
to right auricle.

AO. Aorta.

b. Style passing down from the vena azygos
through superior vena : ava into right auricle.

c. Style passing down from the superior vena
cava into the right auricle.

CA. Conus arteriosus.

el. Left carotid.

er. Right carotid.

d. Style passing from conus arteriosus into left
branch of pulmonary artery.

ef. Style passing up from left ventricle into

aorta.

FO. Place where the ouea ovale existed in
the foetus.

g, h, t. Styles passing through pulmonary vein
into left auricle.

LA. Left auricle.

LV. Left ventricle.

MV. Mitral valve.

m. Innominate artery.

PAL. Left branch of pulmonary artery.

PAR. Right branch of pulmonary artery.

RA. Righ: auricle.

RV. Right ventricle.

sl. Left sub-clavian artery.

SLV. Semi-lunar valve.

sr. Right sub-clavian artery.

TL. Tubercle of Lower.

VCI. Inferior vena cava.

VCS. Superior vena cava.

the thorax, upon the inner surface of the sternum and between the

two lungs.

It is almost globular in shape, but slightly narrows

towards its posterior end or apex, which touches the anterior

surface of the diaphragm.

At its opposite end, or base, the heart is connected with several
great blood-vessels, but elsewhere its surface is free.
The Pera tiR is a bag of dense fibrous tissue with an eniicen

lining,

-@ serous fluid. This

cHAP. vi1.] THE CAT’S ORGANS OF CIRCULATION. 201

bag, the fibres of which interlace in all directions, adheres posteriorly
to the anterior surface of the central tendon of the diaphragm,
while anteriorly, it is attached to the outer coats of the great vessels
which proceed to and from the heart, and is prolonged for some
distance along their course. The internal, or serous, lining of the
pericardium is (after lining the fibrous part forwards to its attach-
ments) reflected back upon the outer surfaces of the great vessels
just referred to, and closely invests the immediate outer surface of
the heart, which is thus (like the roots of the great vessels)
invested both by two layers of. serous, and by one of fibrous
membrane. |

The external surface of the heart indicates its composition, since
two longitudinal furrows indicate the separation of the heart into a
right and left half, while a transverse furrow indicates the separation
of each half of the heart into an anterior and a postericr portion. The
anterior portion of each half is an auricle, and the posterior portion
of each half is a ventricle. The auricular part of the heart (the
two dorsal portions) is thin-walled and soft, and each portion bears
a small appendage something like an animal’s ear—whence the
name “auricle.” The two auricular appendages (one for each
auricle) appear conspicuously on the anterior part of the heart. (See
Fig. 104, RA and ZA.) The ventricular part of the heart (the two
ventricular portions) is thick-walled, firm and slightly conical from
before backwards.

§ 9. GREAT BLOOD-VESSELS are connected with the anterior part
of the heart as follows:—The anterior part of the heart is con-
spicuously distinguished by two large arterial trunks proceeding
from it contiguously, whereof the smaller and more dorsally situated
arches backwards and to the left over the right-hand: branch of the
two branches imto which the larger and more anteriorly situated
trunk divides. This more ventrally situated trunk proceeds
obviously from the night ventricle, it 1s the pulmonary artery, and
its two branches just referred to go respectively to the right and
left lung. The deeper or more dorsal trunk is the aorta, and a
little further examination will show that it proceeds from the left
ventricle. If now the heart be turned round, a large vein will
be seen proceeding forwards to it on what is naturally the right
side of the descending continuation of the arch of the great aorta.
This vein is the vena cava inferior, and opposite to 1t— proceeding
backwards to the heart from the front part of the body—is
another vein, the vena cava superior, which passes backwards on
the ventral side (the heart bemg in its natural position,) of the
right branch of the pulmonary artery. These two great veins
proceed to the right auricle. Other smaller veins (two on each
side) are seen proceeding more or less horizontally inwards to the
heart. These are the pulmonary veins, and they go to the left
auricle. :
§10. The uearr is divided internally into four cavities corre-
sponding with the four-fold division already noticed.

202. . THE CAT. (CHAP. VIX,

_ The whole inner wall of the heart is lined with a layer of
endothelium, which immediately invests a network of elastic fibres.

| a

;

|

Fig. 103.—D1AGRAM OF THE COURSE OF THE CIRCULATION, SEEN DORSALLY.

Aa. Arteries to alimentary tube. PA. Pulmonary artery.
A}, Arteries to anterior parts of body and fore- PV. Pulmonary vein.

limbs. RA. Right auricle.
A*, Arteries to hinder parts of body and hind- | RV. Right ventricle.

limbs. T. Thoracic duct. ‘
Al. Alimentary tube. V1, Veins from anterior parts of body and fore-
Ao. Aorta. limbs.
Ha. Hepatic artery. V2, Veins from posterior part of body and hind-
Hv. Hepatic vein. limbs.
Lct. Lacteals. VCI. Vena cava inferior.
Lg. Lungs. VCS. Vena cava superior.
LA. Left auricle. VP. Vena porta.
Lr. Liver. The vessels which carry venous blood are dis-
LV. Left ventricle tinguished by shading. Arrows indicite the
Ly. Lymphatics. course of the blood-lymph and chyle,

Thus the substance of the heart shows a similarity of structure to
that of the vessels which might be expected, since its walls are

cuap. vu.] THE CATS ORGANS OF CIRCULATION. 203.

directly continuous with the walls of the arteries and veins which
open into it. The muscular fibres, however, of which the heart
is composed are very numerous, forming a thick mass, and they are
of the striated kind and of a deep red colour. Individually, never-
theless, they are smaller than the ordinary striated fibres. They are
also devoid of sarcolemma, and they often branch and anastomose.

The fibres are arranged in layers disposed in various spiral curves
around the cavities of the heart. The muscular walls of the ventricles
are thicker than those of the auricles, and that of the left ventricle
is again thicker than that of the right ventricle. Blood-vessels,
nerves and lymphatics, with fat and areolar tissue, enter into the com-
position of the heart, and fibrous and fibro-cartilaginous structures play
important parts in its composition in connection with certain valves.

These substances are so arranged that (as already remarked) a
complete partition is formed between the right and left sides of the
heart; a septum entirely separating the cavities of the two auricles
and the two ventricles respectively. Thus there is no direct
communication between the ventricles, or between the auricles.

The cavity of the right auricle however communicates not only
with the interior of the vene cave which open into it, but also
with that of the right ventricle, this latter opening being called the
right auriculo-ventricular aperture. Besides this communication
with the right auricle, the right ventricle only opens into the
pulmonary artery. Similarly the cavity of the left ventricle com-
municates not only with the interior of the pulmonary veins which
open into it, but also with that of the left ventricle, this latter
opening being called the left auriculo-ventricular aperture. Besides
this communication with the left auricle, the left ventricle only
opens into the aorta.
§11. The coursE oF THE BLOOD THROUGH THE HEART iS as
follows :—Venous blood is brought back by two large veins (the
vene cave) from all parts of the body to the nght auricle, whence it
proceeds to the right ventricle. From the right ventricle it is
carried to the lungs by the pulmonary artery and brought back
from the lungs by the pulmonary veins to the left auricle; from
thence it proceeds to the left ventricle which distributes it, by
the aorta, over every part of the body.

- Thus the blood, in its course to and from the heart, performs two
different circuits. On the one hand, the whole of the blood passes
from the right ventricle, through the lungs, and back to the left
auricle, thus performing what is called the pulmonary circulation.
On the other hand, the whole of the blood passes from the left
ventricle all over the body, and thence back to the right auricle,
thus performing what 1s called the systemic circulation.

It is while passing through the lungs that the blood undergoes
that process of gaseous interchange which makes it acquire a bright
scarlet colour—the colour of normal arterial blood. On its way to
the lungs it is of a deep purple tint—the colour of normal venous
blood. Thus it comes about that the vessels which carry the blood

204 THE CAT. : | . [CHAP. VIL. oo

from the lungs to the heart carry bright scarlet or arterial blood,
although they (inasmuch as they are vessels conveying blood towards
the heart) are called ‘‘ veins’’—the pulmonary veins. Similarly,
the vessels which carry the blood from the heart to the ungs contain
dark purple or venous blood, although they (inasmuch as they are
vessels conveying blood from the heart) are called “ arteries””—the
pulmonary arteries. :

§ 12. The current of the blood through the heart is kept up by

the alternate contraction and dilatation of its four chambers, which -

is brought about by the successive contraction and relaxation of its
various sets of muscular fibres. Its course through the heart is,
however, determined by the action of certain vALVEs which guard its
most important apertures, and which, by acting like the valves of
the veins, readily allow the blood to pass in one direction, while
they oppose an effectual barrier to its passage in the opposite direc-
tion. The valves which most resemble those of the veins are the
valves which are placed at the root of the aorta and pulmonary
artery. These are called semtlunar valves, and there are three in
each vessel. They consist of processes of fibrous tissue (invested
with endothelium), and each is continuous by one curved edge with
the wall of the artery, while the other edge hangs freely so far out
from the wall of the vessel that the whole three valves, when so
hanging, meet together (by a tri-radiate suture), and form a complete
partition across the vessel. The margin of each valve is strengthened
by a tendinous band, and at its middle is a small fibro-cartilaginous
nodule called a corpus Aurantit.

While the blood is flowing from the contracting ventricles, these
valves lie back against the inner walls of the arteries, but when the
ventricles dilate and the elasticity of the arterial walls tends to drive
the blood back into the ventricles, these valves immediately descend,
and the greater the pressure from above, the more completely and
accurately do they close together.

At the roots of the pulmonary veins there are no valves, and there
is only a rudimentary one at. the root of the vene cave. At each
of the auriculo-ventricular openings, however, there is a valve of
complex structure, consisting of membranous flaps, with delicate
tendinous cords (chorde tendinee) attaching them to papillary pro-
longations inwards—columne carnee—of the muscular ventricular
walls.

The valve of the right auriculo-ventricular aperture is called the
tri-cuspid valve, because it consists of three segments. The delicate
tendinous cords above named proceed partly from the walls of the
ventricle (especially the septum), but mainly from little muscular
prominences—the columnz carne. The tendinous cords are so
distributed that some of those from each origin proceed to the edge

of one valve, while the others proceed to the adjacent edge of another _

valve —thus diverging as they advance (Fig. 102, B).
The valve of the left auriculo-ventricular aperture is called the
bi-cuspid or mitral valve, and consists but of two segments. It is

i m) aS ial Ot

AiO ea es UE Ae Oe, oo Bes

ee

cHAP. vi.] THE CAT’S ORGANS OF CIRCULATION. 205

much thicker and stronger than the tri-cuspid valve, but its essential
arrangement 1s the same.

The action of the tri- and bi-cuspid valves is similar, and is
inverse to that of the semi-lunar valves. When the auricles
contract and the blood tends to flow into the ventricles, these
valvular flaps readily bend backwards and allow it free passage ;
but when, by the contraction of the ventricles, the blood tends to be
driven into the auricles as well as into the great arteries, then these
valves immediately close, and are pressed towards the auricles, while
they are prevented from going too far (and so being driven into the
auricles) by the numerous chord tendinez which hold them firmly
attached, as the cords of a tent hold and sustain it. The exactness
with which they meet together is rendered complete by the columne
carnee themselves, which participate m the contraction of the cavity
from the walls of which they proceed. |

§ 13. The ricHT avricLe (Fig. 102, B, RA) is situated at the
ventral side of the base of the heart, and has a smooth surface.
The superior vena cava (which is very short) opens into the anterior
portion of this chamber, and the inferior vena cava opens by a larger
opening into its posterior part—above the auriculo-ventricular
aperture—while between them is the orifice of a small vein called
coronary, which brings back the blood from the walls of the heart
itself. This part of the cavity (as distinguished from the cavity of
the auricular appendage) is called the sinus venosus. At the hinder
part of the septum, which divides this auricle from the left one, is
an oval depression called the fossa ovalis (FO), which is the mdica-
tion of a foetal condition, for, as we shall see, in the embryo an
opening leads directly from one auricle to the other. Immediately.
in front of this is a marked transverse prominence called the tubercle
of Lower (TL).

The LEFT AURICLE, which, when distended, has a somewhat
quadrangular appearance, lies to the left on the dorsal aspect of the
base of the heart. The openings into it of the pulmonary veins are
dorsally placed, and there are usually two on each side. Those of
the right side, however, meet together close to the auricle, so that
there seems to be but one pulmonary vein opening into it on that
side. The wall of the septum shows a slight depression, correspond-
ing with the fossa ovalis of the right auricle.

The RIGHT VENTRICLE forms the right side of the ventral aspect
of the heart from the transverse furrow onwards towards its apex.
Internally it presents the valvular structure (the tri-cuspid valve)
already described, but its upper and anterior part is smooth and
free from columnee carnee. It is also prolonged forwards in a
conical manner, whence this part has been named the conus
arteriosus (CA). The left wall of the ventricle is convex, the septum
between the ventricles so bulging into its cavity as to make that
cavity appear crescentic when the right ventricle is transversely
bisected. The muscular wall of this chamber is much thicker than
that of either of the auricles. The opening (with its semi-lunar

206 OS a Nene a - fouar. vir,

valves) which leads into the pulmonary artery is remote from the
auriculo-ventricular opening.

The LEFT VENTRICLE, by far the thickest-walled portion of the
heart, extends backwards to its apex mainly on the posterior aspect
of the organ. The side which is formed by the septum is concave
instead of convex—the transverse section of the cavity of this
ventricle being oval. The opening (with its semilunar valves)
which leads into the aorta is close beside the auriculo-ventricular
opening, but to the right, and somewhat ventrally to the latter.

The coronary arteries, which convey the blood for the nutrition of
the substance of the heart, do not lead from the cavity of the
ventricle itself, but from the aorta (one opening on each side)
immediately in front of the attachment to it of its semi-lunar valves.

§ 14. All the arrertes of the body, with the exception of the
pulmonary artery and its branches, are larger or smaller ramifica-
tions of that great artery, called the aorta; and all without exception,
therefore, are ramifications of vessels which proceed directly from
one or other of the ventricles of the heart. Those which proceed
from its right side, are the arteries of the pulmonic circulation,
and carry venous blood; those which proceed from its left side, are
arteries of the systemic circulation, and carry arterial blood.

The PULMONARY ARTERY is the most capacious vascular trunk in
the body, but is very short. Arising from the conus arteriosus, it
passes dorsally and to the left, and then bifurcates. One branch
passes to the right, above the arch of the aorta. It then divides
and sub-divides within the right lung. The other branch passes
to the left, beneath the dorsally and posteriorly-extending part
of the aortic arch, and then divides and sub-divides within the
left lung. Each pulmonary artery, at the root of the lung, lies
dorsally to the pulmonary veins, and ventrally to the air-tube or
division of the windpipe, which there enters the lungs. A little to
the left of its bifurcation, the pulmonary artery is connected by a
fibrous band with the concavity of the aortic arch. This band is
- the relic of a foetal tubular structure, which in the embryo places
the cavities of these two great arteries in direct communication, and
is then called the ductus arteriosus (Fig. 104, da).

§ 15. The aorta springs from the base of the heart, rather
dorsally to the pulmonary artery and between the anterior ends of the
two auriculo-ventricular apertures. It arches to the left, over the
right branch of the pulmonary artery, and over the root of the left
lung, till it reaches the front—z.e., the ventral side of the vertebral
column. ‘Thence it passes backwards through the hinder margin of
the diaphragm, and ends by dividing into the iliac arteries, which
go to the pelvic viscera and pelvic limbs.

The aorta is, as it were, the axis of the systemic arterial system ;
and (apart from small branches and large vessels given off to the
abdominal viscera) may be said to give off eight branches or sub-
divisions, four being anterior and four posterior. Of the four
anterior branches, one goes to each pectoral limb and one to each

ur a_gel r. arc) ee et Mas
oi Oe i —s ri ert .e ee

onaP. vi] THE CATS ORGANS OF CIRCULATION. 207

side of the head. The four posterior branches are the iliac
arteries already referred to. Besides the aortic arch, the rest of its
course, which is called the descending aorta, is sub-divided into the
part in front of the diaphragm and the part below it—z.e., into the
thoracic and the abdominal aorta. |

The arch of the aorta gives off, almost from its very starting
point—as before mentioned—the coronary arteries (which go to
the heart itself), and afterwards the four great vessels (which

Fig. 104.—THe HEART, GREAT VESSELS AND LUNGS OF THE CaT ; VENTRAL ASPECT.

Ao. Arch of aorta. VS. Vena cava superior.

cC. Carotid arteries. Ve. S. Vena azygos.

Da. Ductus arteriosus. 1. Upper lobe of right lung.

LA. Left auricle. 2. Second lobe of right lung.

LV. Left ventricle. 3. Third lobe of right lung.

PA. Pulmonary artery. 4. Fourth or lowest lobe of right lung.
RA. Right auricle. 4a. Partly separate portion of fourth lobe.
RV. Right ventricle. 5. Upper lobe of left lung.

T. Trachea. 5a. Partly separate portion of the same.
IV. Vena cava inferior. 6. Lower lobe of lef. lung.

go to the head and fore-limbs) by two very unequal trunks. One of
these, the larger, and placed on the right, is called the cnnominate
artery. (Fig. 102, n.) It soon gives off a large branch (c/), which is
the deft carotid artery ; and the remaining part, almost immediately
bifureates into the right carotid and the right sub-clavian arteries.

Si RNS SAVE RAL ORD y eee Oe ae 5
oS Sy aL ee a SD

7 \
208 He _ ‘THE CAT.

The second and much smaller vessel given off from the arch of the
aorta, is the root artery of the arteries of the left fore-limb—z.e., it
is the left sub-clavian artery (s/). After giving this off, the aorta
passes upwards as the thoracic part of the great dorsal (in man, the
“ descending”) aorta. It gives off a number of branches, which
will be referred to shortly.

§ 16. The two caRoTID ARTERIES pass forwards along the neck,
one on the right and the other on the left side of the trachea and
cesophagus, to the head. Each gives off in succession the following
branches :—Each gives off a rather large artery to supply the muscles
of the side of the neck ; and, opposite to this, a small branch to the
lymphatic gland lying on the middle of the trachea. Next comes the
thyroid artery, which goes to the thyroid cartilage, and to a structure
to be hereafter described as the thyroid gland. It then gives off (from
its opposite side) another artery to the muscles of the neck, and (almost
opposite this) a very large lingual artery, which passes dorsally to the
basi-hyal, beneath the stylo-glossus, and goes to the under surface of
the tongue. The carotid next gives off a small facial artery, which
sends out branches to the cheek, and ends in the upper and lower
lips. A small branch goes to the sub-maxillary gland, starting
from the very root of the facial artery. The carotid artery then
makes a sharp bend, and gives off backwards a branch to the
parotid gland; and then, at the further end of the curve, another
branch, which also goes in part to the parotid gland, and a part to
the muscles of the temporal fossa. This arched part of the carotid -
ends anteriorly, close to the anterior margin of the glenoid surface.
The carotid then breaks up into a plexus of minute branches, which
run side by side under the eye-ball, and over the orbital plate of the
maxilla. From this plexus minute arteries are given off, such as
the ophthalmic, ciliary, ethmoidal and meningeal arteries.

The ophthalmic artery passes along the inner side of the orbit,
giving off branches to the lachrymal gland, the forehead and muzzle,
the eye-ball and nasal cavity, the latter being called the ciliary and
ethmordal arteries. oy

The meningeal artery supplies the dura mater. It enters the
skull from the plexus, through the sphenoidal fissure.

The nasal artery is a small branch which passes through the
spheno-palatine foramen (in company with the nasal nerve), and
continues on, skirting the nasal septum.

The carotid also gives off the superior dental artery, which enters
the maxilla posteriorly, and supplies the upper teeth. Finally, the
carotid passes through the infra-orbital foramen, and terminates as
the infra-orbital artery, which distributes its branches about the
face.

A very minute vessel, called the internal carotid, is given off
from the main carotid in the vicinity of the foramen lacerum
posterius. It enters that aperture, and passes along a slender canal
between the basi-occipital and basi-sphenoid, and the adjacent part
of the temporal bone. It then enters the cranial cavity on the

[cuar. vn

: cHap, vi] THE CAT’S ORGANS OF CIRCULATION. 209

inner side of the anterior end of the petrous part of the temporal
bone, and unites with the circle of Willis, formed by the branches of
the basilar artery The internal carotid artery is so minute that it
would not be worthy of note were it not for its large size im man and
many other animals.

- §1% The supcLaviAN ARTERY is the root artery of the fore-limb.
That of the right fore-limb springs from the larger branch of the
mnominate artery. That of the left fore-limb takes origin directly
from the arch of the aorta.

The subclavian artery first approaches the clavicle, and then,
arching over the first rib, recedes to the axilla and becomes the
axillary artery.

The first branch given off by the-subclavian is the vertebral artery.
It bends rather sharply upwards to pierce the transverse process of
the sixth cervical vertebra. It then advances through the perfora-
tions of the other cervical transverse processes, till, having traversed
that of the axis, it bends at a right angle to reach the notch between
the transverse process and the anterior articular process of the same
bone. It then traverses the atlas, and, finally, entering the cranium
through the foramen magnum, it unites (on the upper surface of the
basi-occipital) with its fellow of the opposite side to form the basilar
artery. |

The basilar artery runs forwards as a long single vessel, gives off
a branch on each side, and then continues on to form a circular
vessel around the infundibulum and pituitary body in its sella
turcica. This circular vessel is the circle of Willis, already men-
tioned; the internal carotids unite with it, and branches to the
braim are given off anteriorly and laterally from it.

The second branch given off from the subclavian on the same
side as the vertebral, is the thyroid avis. it arises covered in by
the sealenus muscle, and arches forwards and upwards over the
scapula—sending a branch up to the thyroid body.

A considerable vessel, the ¢nternal mammary artery, is given otf
directly opposite to the thyroid axis. It passes backwards along
the inside (dorsal surface) of the cartilages of the ribs. It gives
off a long and very slender branch, called the siperior phrenic,
which passes backwards to the diaphragm between the lung-root
and the pericardium.

The superior intercostal artery, extends along the inside of the first
three ribs, supplying the intercostal muscles. About half-an-inch
beyond the origin of the thyroid axis a second artery is given off,
which arches forwards and upwards over the scapula.

§ 18. The subclavian becomes the axILLARY ARTERY as it passes
into the axilla, between the pectoralis, subscapular, and latissimus
dorsi muscles, surrounded by the nerves of the brachial plexus. It
gives off various branches, as follows: the superior thoracic, which
goes to the pectoral muscle ; the acromial thoracic, which is large and
divides intoadvancing and receding branches which respectively supply

the deltoid, pectoralis and serratus magnus muscles ; the ong thoracic
P

210 THE CAT.

and alar-thoracic arteries, which go respectively to the thoracic

muscles and axillary lymphatic glands; finally, the anterior and
posterior circumflex arteries (the latter being very large) which pass
round and embrace the uppermost portion of the humerus.

Below the axilla the axillary artery takes the name of brachial,

and descends to the elbow between the biceps, the coraco-brachialis, —

and the brachialis anticus muscles. It gives off a branch called the
superior profunda artery, which accompanies the muscular spiral
nerve and winds round the back of the humerus to its outer lower
part. Another branch, the inferior profunda artery, is given off
lower down, and passes to the inner side of the lower part of the
arm—in company with the ulnar nerve. Having passed through
the internal condyloid foramen and reached the concavity of the
elbow, the brachial artery divides into two branches, called the
radial and ulnar arteries. |

The ulnar artery (which is much smaller than the radial) passes
along on the ulnar side of the flexor surface of the fore-arm (beneath
the pronator teres, flexor carpi radialis, palmaris longus, and flexor
sublimis muscles) into the palm, when it joins a branch of the radial
artery to form a loop called the palmar arch.

Soon after its origin the ulnar artery gives off a branch called |

the interosseous artery, which descends along the anterior surface
of the interosseous membrane.

The radial artery continues on the line of the brachial artery,
and extends along the flexor aspect of the radius to the wrist, when
it turns to the dorsal surface of the fore-paw and then penetrates
between the second and third metacarpal bones, and unites with a
branch of the ulnar artery to form a palmar arch. The radial artery
is more superficial than the ulnar, being only overlapped by the
supinator longus muscle. The palmar arch gives off a very small
artery to the pollex and larger ones, which subdivide and go to the
four other digits.

§ 19. The rHoracic aorta passes backwards to the left and
ventral side of the vertebral column extending to the diaphragm,
after perforating which it becomes the abdominal aorta. It hes in
the posterior mediastinum (or dorsal space between the lungs)
beside the cesophagus. It gives off many small arteries, such as the
bronchial arteries (to nourish the lungs and the air-tubes), those of
the cesophagus and intercostal arteries, which supply those intercostal
spaces which are not supplied by the intercostal branch of the sub-
clavian. Each intercostal artery passes along the posterior margin
of a rib on the deep surface of the external intercostal muscle. The
vessels of the right side have, of course, to cross transversely the
ventral surface of the vertebral column. ach intercostal also gives
off a small posterior or dorsal branch, which ascends, inside the ante-
rior costo-transverse ligament, to the muscles of the back. The two

hindmost intercostals on each side are rather lumbar than dorsal —

arteries, since they traverse the trunk behind the last rib.
- The ABDOMINAL AORTA is the continuation backwards, beyond the

cHAP. vil] THE CAT’S ORGANS OF CIRCULATION. — 211

diaphragm, of the thoracic aorta. It gives off certain noteworthy
branches—the inferior phrenic, lumbar, cceliac, mesenteric, supra-
renal, renal, and spermatic (or ovarian) arteries—and then ends by
dividing into five parts, namely, its really posterior termination,
the caudal, or inferior sacral, artery, and the two internal and two
external iliac arteries.

The inferior phrenic, which is exceedingly small, goes to the
hinder surface of the diaphragm, and gives off a branch which
extends along the psoas. The Jwmbar arteries continue on back-
wards, the series of intercostals quite resembling the last two of the
latter, which go to the lumbar region. They also give off a dorsal
branch, which passes upwards between the transverse processes of
the vertebre. The main trunk of each runs down amidst the
abdominal muscles, which it supplies. The celiac artery, or cehac
axis, is a short and wide vessel which arises close to the diaphragm,
and quickly divides into three important visceral branches : |

A. The first of these is the coronary artery of the stomach, which
extends along the smaller curvature of the stomach from its
cardiac orifice.

B. The second of these is the hepatic artery, which passes up-
wards to the transverse fissure of the liver, where it divides and
ramifies in the substance of the liver in the portal canals, along
with the portal vein and hepatic duct.

C. The third branch of the cceliac axis is the splenic artery, which -
extends to the left above the pancreas to the spleen, giving off,
however, some twigs to the cardiac surface of the stomach.

A fourth branch may go to the right supra-renal capsule.

The superior mesenteric artery is a very large vessel supplying the
whole small intestine (except the duodenum), together with the
coecum and first part of the large intestine. It subdivides (to go to
the intestine) in the folds of the peritoneum.

The inferior mesenteric artery is very much smaller than the artery
last described. It passes out between the mesenteric peritoneal folds
to the hinder part of the large intestine.

The capsular or supra-renal arteries, are very small. They arise,
one on each side, near the superior mesenteric artery, and pass
obliquely outwards, to organs hereafter to be described as the supra-
renal capsules.

The renal arteries (Fig. 105, a) are exceedingly large, but short.
They are two in number, and they pass out, one on each side,
horizontally from the aorta, a little behind the superior mesenteric
artery (that of the right bemg a little the more posterior, and, from
the relation of the aorta to the spine, the longer), and go to the
kidneys, each dividing into four or five branches before it penetrates
the kidney, in the substance of which it ramifies, as will be hereafter
described.

The spermatic, or ovarian arteries, are also two in number,
but each is very long and exceedingly slender. They arise side by

side, a little behind the renal arteries, from the ventral aspect of the
P 2

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[cHAP, VIT. is

212 | THE CAT.
aorta. Each passes backwards and outwards, over the psoas muscle, =

to the internal abdominal ring, through which, in the male, it

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Fig 105.—ABDoMEN OF A FEMALE CAT OPENED, AND WITH THE STomaCH, INTESTINES, AND
LIVER REMOVED, SO AS TO SHOW THE KIDNEYS, UTERUS, BLADDER, AND GREAT
BLOOD-VESSELS IN POSITION.

1. Lymphatic vessel.

a. Renal artery.
o. Ovary of right side.

ao. Aorta passing through the diaphragm. |
b. Bladder. ‘ ov. Ovarian vessels of right side.
c. Right cornu of uterus. | r. Rectum, cut across behind the body of the
d. Part of the diaphragm with the opening for | uterus.
the vena cava. ) sr. Supra-renal capsule of right side.
f Fallopian tube. | u. Ureter of right side, proceeding from kidney.
4. Left iliac arteries, showing the distinct origin | u* Ureter of left side entering bladder.
from the aorta of both the external and | wt. Uterus.
internal iliac. v. Renal vein.
k. Kidney of left side. vc. Vena cava inferior cut across above.

descends to the testicle. In the female, the vessel inclines inwards,
and passes, between the folds of the broad ligament, to the ovary. _
§ 20. The m14c ARTERIES.— Having reached nearly the hinder end

cHAp. vi.] THE CAT’S ORGANS OF CIRCULATION. 213

of the abdominal cavity, the aorta gives off two large arteries which go
one to each hind limb respectively, and each of which is named an
external iliac artery. After continuing on for a short space further,
the aorta gives off another pair of rather smaller vessels called the
internal iliac arteries (Fig. 105, i) ; the aorta then immediately bends
sharply upwards, and thenceforth continues onwards, gradually
narrowing, beneath the middle of the tail as the caudal artery, which
gives off twigs to the caudal muscles.

The INTERNAL ILIAC, or hypogastric artery, dips down into the
pelvis, and gives off a variety of branches. Amongst them we have
the superior vesical, which goes to the side of the bladder, and is con-
nected with the umbilicus (or navel) by a fibrous cord—a relic of
an important fcetal structure; the inferior vesical, which goes to the
bladder, and, in the male, to a part to be hereafter described as the
prostate gland ; the uterine and pudic arteries, which go to the uterus
and external generative organs ; the gluteal artery, which passes out
of the pelvis, between the pyriformis and gluteal muscles, supplying
the latter ; and the sciatic artery, which passes out of the pelvis at the
great sciatic notch, and goes (between the greater trochanter and the
tuberosity of the ischium) to the muscles of the hip and thigh.

§ 21. The EXTERNAL ILIac artery 1s very conspicuous on the
inside of the thigh. It passes backwards, downwards, and outwards,
and soon gives off a large branch called the obturator artery, which
passes out of the pelvis through the obturator foramen. From the
obturator artery is given off the epigastric artery, which passes for-
wards in the middle of the abdominal wall, and anastomoses with
branches of the internal mammary artery.

Having passed beneath Poupart’s ligament to the thigh, the ex-
ternal iliac assumes the name of the femoral artery, and descends
along the imside of the thigh, resting successively on the psoas,
pectineus, and adductor muscles. Near its origin, the femoral gives
off a large branch called the deep femoral, which passes in through
the adductor muscle, and ramifies in the muscles of the hinder and
outer parts of the thigh.

Before reaching the back of the knee-joint, the femoral artery
divides into the anterior and posterior tibial arteries.

The POSTERIOR TIBIAL ARTERY runs down behind the tibia, upon
the tibialis posticus and flexor longus digitorum muscles, to the inner
side of the os calcis, where it divides into the external and internal
plantar arteries. The first of these goes to the base of the fifth
metatarsal, and then passes obliquely between the metatarsals to
anastomose with the dorsal artery of the foot, so forming a plantar
arch. The second, or internal plantar, proceeds along the inner side
of the sole of the foot towards the index.

The posterior tibial gives origin to a branch called the peroneal
artery, which descends behind the leg close to the fibula, and in
contiguity with the flexor longus hallucis to the outside and back of
the os calcis.

The anterior tibial artery passes forwards to the front of the

214 , THE CAT. | [oar viz,

inter-osseous membrane. It then turns downwards and passes to the
middle of the front of the ankle, where it assumes the name of
dorsal artery of the foot, and runs on between the metatarsals of the
index and middle digits, where it divides, one part sinking to
anastomose with the external plantar artery (as already mentioned),
and the other part going to the imner side of the foot. This and the
plantar arteries give off small vessels to the digits, similar to those
given off to the digits in the fore-paw.

§ 22. The vuins are, with the exception of the portal vein,
afferent vessels beginning by minute tubes, which converge and unite
to form larger and larger trunks. They cannot, like the arteries,
be grouped in only two sets of vessels—those of the pulmonary and
of the systemic circulation respectively—because there are veins —
which belong to a third category, already noted as those of the
portal circulation, which ramify and distribute the venous blood
from the spleen, pancreas, stomach, and intestine, within the sub-
stance of the liver. With the exception, however, of the veins of
the pulmonary and portal circulations, all the veins of the body are
larger or smaller tributaries to those great vessels, already more than
once referred to as the superior and inferior vene cave, and which
open directly into the right auricle of the heart. The veins which —
pass from the lungs to the left auricle, are those of the pulmonary |
circulation; while those veins which arise in the spleen, pan-
creas, stomach, and intestine, and those which ramify within the
substance of the liver, together constitute the portal system. The
whole of the blood passes at each circuit through both the pulmonary
and systemic circulations, but only a portion of the blood has a share
each time in the portal circulation. Thus both the systemic and
pulmonary circulations are served both by arteries and by veins,
and in each the blood is in one part arterial and in another venous,
but the portal circulation is served by veins only, and its blood is
venous entirely throughout. - |

There is yet another antithesis: in both the systemic and pul-
monary circulations the circuit is complete, the vessels being
connected together by capillaries, as well as by large trunks. The
portal circulation is incomplete in so far as it is connected by minute
vessels only, there being no direct connexion between the large trunks
which send blood to, and those which receive it from, the liver. ©

The PULMONARY VEINS are the only veins which convey arterial
blood. They arise by minute branches in the lungs (as will be
again noticed with the description of the breathing organs) ; they
converge to form four vessels, two on each side in the root of each
lung. These empty themselves into the left auricle. Those of the
right side pass behind the right pulmonary artery and on the dorsal
side of the vena cava superior and the aorta. Those of the left side,
which are the shorter, pass ventrally to the descending .aorta.

The pulmonary veins of the right side unite with one trunk just
before opening into the auricle.

As has been before said, many of the sysTEMIc VEINS consist of a

_ cap. vi.] THE CAT’S ORGANS OF CIRCULATION. 215

double set, one deep and one subcutaneous. They moreover com-
municate and anastomose together more frequently than do the
arteries. The systemic veins are naturally divisible into (1) those
which ultimately pour themselves into the vena cava superior, and
(2), those which convey blood to the vena cava inferior. To the
first category belong the veins of the head, the pectoral limbs, the
vertebral column, and part of the thoracic and abdominal walls. To
the second category the veins of the pelvic limbs, of the lower part
of the trunk, and of the abdominal viscera.

The veins of the outside of the cranium and face converge to form
the temporal, internal maxillary and facial veins ; the temporal passes
through the parotid gland and becomes (having united with the two
others), the EXTERNAL JUGULAR VEIN (see Fig. 88), which, be-
ginning at the mandibular angle, descends, crossing the sterno-
mastoid muscle, to the great subclavian vein.

The blood from the brain and inside of the cranium collects in
reservoirs called the cranial sinuses, which groove the inner surfaces
of the bones of the skull.* The blood from all these sources
collects at the opening called the foramen lacerum posterius or
jugular foramen, and the vein which passes out through it, receives
the name of the INTERNAL JUGULAR VEIN, which vein descends
outside and parallel with the common carotid artery, till it joins the
subclavian vein (the junction being furnished with a valve), when
the two, by their union, form the -RIGHT INNOMINATE (or brachio-
cephalic) vein.

The veins of the digits, fore-paw, and arm of each side, partly
unite to form a sub-cutaneous network, which ends in larger channels
(radial, ulnar, and median), which unite and end, sooner or later,
in the azillary vein.

The veins of the digits, fore-paw, and urm, also unite to form a
deep set-of veins which accompany, as vene comites, the tributaries
of the brachial vein, uniting and ending ultimately in a single trunk,
the AXILLARY VEIN, which, as it passes over the first rib, assumes
the title of suBCLAVIAN, and receives the contribution of the external
jugular vein, as already mentioned, as also that of the vertebral
vein, which descends through the canal of the cervical transverse
processes in company with the ascending vertebral artery. Near
the clavicle, the subclavian vein unites with the internal jugular to
form the innominate vein already mentioned. Finally, the in-
nominate vein unites with its fellow of the opposite side to form the
VENA CAVA SUPERIOR, which passes down in front of the pulmonary
vessels of the right side, and to the right of the aorta, to the right
auricle. |

Valves are found in the veins of the pectoral limb generally, but
especially in the deep veins. 3

The veins of the digits, hind-paw, and leg of each side, also partly

* The middle of the skull root and the occipital and temporal bones as already
described, see ante, pp. 62 and 66.

216 aS ELE ae,

unite to form a subcutaneous network, which ends in two main >

channels. The larger of these, the saphenous vein, runs up the
inner side of the foot, leg, and thigh, beneath the skin, and
terminates in the femoral vein. :

The veins of the toes, hind-foot, and leg, also unite to form a deep
set of veins, which accompany the arteries as vene comites, and
which are more richly supplied with valves than the superficial
veins. The various tributaries ultimately unite to form the
FEMORAL VEIN, which, as it passes beneath Poupart’s ligament
with the femoral artery, assumes the title of EXTERNAL ILIAC
VEIN.

Meantime, the small veins of the pelvic viscera unite into larger
vessels, generally corresponding with the divisions of the internal
iliac artery (except that there is no remnant of any foetal venous
structure, save that going to the liver as the “round hgament”’),
and ultimately unite in a large valveless vessel called the INTERNAL
IL1ac VEIN. The external and internal iliac veins unite to form a
single vessel—the vena cava inferior.

This VENA CAVA INFERIOR is very much longer than the superior
vena cava, and advances on the right side of the descending aorta.
It then bends downwards, perforates the diaphragm, and ends in the
right auricle. As it advances from its origin it receives important
accessions, corresponding, to a certain extent, with branches directly
given off from the abdominal aorta. They are:— _

The caudal vein, which is really the posterior commencement of
the lower vena cava, as the caudal artery is the real termina-
tion of the aorta.

The Jumbar veins.

The phrenic veins.

The spermatic veins.

The renal veins.

The capsular veins.

All these sets of veins correspond with the similarly-named
arteries, but there are no veins entering the vena cava which
correspond with the superior and inferior mesenteric arteries, or
with the cceliac axis, but veins enter it directly, which are called
hepatic, though they do not correspond, either in situation or distribu-
tion, with the hepatic artery. They do not correspond in situation,
because they enter the vena cava anteriorly to the point at which
the coeliac axis (of which the hepatic artery is a branch) quits the
aorta. They do not correspond in situation, because the hepatic
artery enters the liver at its transverse fissure, and ramifies in the
portal canals, while the hepatic ves run in quite differently directed
channels, and converge to the groove in the dorsal margin of the
liver, in which lies the vena cava, into which vessel they directly
empty themselves. The hepatic veins are valveless.

§ 23. The veins which correspond with the mesenteric arteries, |

and -with the branches of the coeliac axis, constitute the PORTAL
system. Thus we have the superior and imferior mesenteric vems,

ss guar, vi.] THE CAT'S ORGANS OF CIRCULATION. 217

which converge as the corresponding arteries diverge, and empty
themselves into the splenic vein, which returns blood from the
pancreas as well as from the spleen, and also a vein from the
stomach along its greater curvature.

The veins thus. converging form the portal vein. ‘This portal
vein passes to the transverse fissure of the liver above the hepatic
artery and duct, enclosed in the gastro-hepatic omentum. Arrived
within the fissure, it divides right and left, and ramifies in the right
and left portions of the liver, forming the great vessel of each portal
canal. The portal vein is without valves.

§ 24. Another system of venous structures goes by the name of
the Azycos VEIN, although there are really a pair—one on each
side. They are elongated vessels advancing one on each side of the
spine, but more or less irregular in form and arrangement. They
are formed by the union of the ¢ntercostal veins (corresponding with
the intercostal arteries) and are tolerably symmetrical behind, but
anteriorly some of the veins of the left side of the body, though not
those of the three or four upper intercostal spaces, are poured into
the right azygos vein, which thus becomes enlarged.

They begin behind in the lumbar veins, and the right azygos. vein
advances and passes through the diaphragm, with or near the aorta,
till near the root of the right lung, where it turns downwards and
empties itself into the vena cava superior (Fig. 104, vz), very near
the right auricle. |

The left azygos vein also commences with the lumbar veins,
advances and passes through the diaphragm, with or near the aorta,
and remaining very slender, ends by opening into the left innominate
vein. The azygos veins have valves.

The veins of the heart itself open into the.right auricle between
the auriculo-ventricular opening and that of the vena cava
inferior.

Thus the heart may be said to have a small circulation of its own—
in addition to the systemic, pulmonary and portal circulations already
mentioned. For blood from the coronary arteries* flows from the
root of the aorta to the substance of the heart, whence it is directly
returned by these coronary veins.

§ 25. The lymphatics or absorbent vessels (including the alimentary
lacteals,) seem to arise by minute vessels in every part of the body,
which form a system of tubes (of different sizes,) and reservoirs (or
sinuses).

Some of these latter are much dilated, for the great peritoneal
sac, with the other serous sacs—including those investing the
nervous centres—are to be regarded as being really large lymphatic |
sinuses or interspaces, because the lymphatic vessels communicate
with the peritoneal cavity by definite apertures called stomata.
Thus the lymphatic system is not so closed a system as is the

* See ante, p. 206.

218 | THE CAT. _ [CHAP. VII.

sanguineous system. It is not so because the peritoneal cavity
communicates (in the female cat) directly with the exterior by means
of the Fallopian tubes, while the sanguineous system only commu-
nicates with it indirectly through the opening into it of certain
lymphatic vessels. The mode in which lymphatic vessels ab-
solutely commence is a matter not yet satisfactorily ascertained,
but it seems they open at their minute extremities into mere vacuities
in the ultimate parenchyma of the body. Thus the whole lymphatic
system may be regarded as an enormously and most complexly
ramifying body cavity, the ramifications of which have all acquired
a lining membrane, save the must ultimate ones, from which ultimate
terminations the lymphatic vessels, therefore, seem to take their
origin.

The various lymphatic vessels ultimately gather themselves
together from all parts of the body into one or other of two
longitudinal vessels, which are named the right and deft lymphatic
ducts, and which are very unequal in size.

That of the right side receives only the lymphatics of the head
and the fore-limb of its own side and from the same side of the

chest. That of the left side receives not only the lymphatics of the

head, arm and part of the chest of its own side, but also those
of both the hinder limbs and all the lacteals. It is distinguished
by a distinct name, the thoracic duct, but it and the right lymphatic
duct, respectively open into the subclavian vein of its gwn side, just
where it receives the accession of the jugular vein.

The THoracic pucr advances along the ventral side of’ the spinal
column from a somewhat dilated part called the receptaculum chyh,
which lies on the right side of and rather dorsally to the aorta.
The duct passes forwards, inclining to the left, to the root of the

_ neck, where it terminates, as before stated.

LyMPHATIC GLANDS.—There is a considerable cervical gland, about
the size of a very small bean, just behind the external jugular vein —
at the level of the clavicle.

Other lymphatic glands le near the axilla, a group of three or
four being covered by the latissimus dorsi muscle near its insertion.
Others are situated more deeply in the axilla.itself.

A few lymphatic glands lie in the thigh just beneath the skin
at about half an inch from the pubic symphysis.

Yet other lymphatic glands are to be found, besides various blood-
vessels and viscera.

A large gland lies at about the middle of the trachea on its ventral
aspect, immediately beneath the sterno-thyroid muscle, and a smaller
one lies more anteriorly and superiorly near the angle of the
mandible. |

Certain lymphatic glands, placed in the mesentery, are known as
mesenteric glands. The lacteals collect together and traverse. them
on their way to the larger lymphatic trunks. Most of the mesen-
teric glands are aggregated together into an elongated mass, which

cHAP. VIL] THE CAT’S ORGANS OF CIRCULATION. 219

is placed near the root of the mesentery, and which mass is often
called the pancreas of Aselli. There are, however, five or six isolated.
glands of this kind in the vicinity of the large intestine.

After passing through the mesenteric glands, the lymphatics
converge, increase in size, and finally enter the thoracic duct
towards its hinder end.

CHAPTER VIII. .

THE CAT’S ORGANS OF RESPIRATION AND SECRETION.

§ 1. The FUNCTION OF RESPIRATION is that one of all the func-
tions of the body which is the most conspicuously necessary for the
maintenance of life. Let this function be interrupted m the adult
eat* but for ten minutes (whether by external obstruction, the
absence of the requisite gaseous material, or by paralysis of the
respiratory organs), and death is the necessary result. It has been
already mentioned in the chapter on Alimentation, that oxygen is
taken into the body through the lungs; and it has also been -
stated—in the last chapter—that the blood undergoes a conspicuous
change (from its purple venous state to its scarlet arterial condition)
during the pulmonary circulation. This change is due to the
absorption by the blood, and consequent increase of its supply, of
oxygen, and to the elimination from the blood of more or less of its
carbonic acid.

It is this interchange of gases between the living animal and the
surrounding air which constitutes “breathing,” or respiration. But
the animal we are considering may be said to have two processes cf
respiration—one “ internal,” the other relatively ‘‘ external.” Such
is the case, because the oxygen received into the blood does not
remain there, but is carried by the circulation to the remotest
recesses of the body, where it unites with that body in its jnnermost
substance or parenchyma.

Similarly, the carbonic acid which the blood sets free does not
originate in the blood, but is given forth into the blood from all the
ultimate particles of the same parenchyma.

Thence, the blood gathers it, and conveys it outwards for dis-
charge in the lungs. The blood, therefore, is a great distributor,
which both gives out and takes in oxygen and carbonic acid at
either end of its course, from the lungs to the mnermost body
substance.

In the lungs it gives out carbonic acid, and takes in oxygen (as
has just been said) ; while in the inmost recesses of the body it

* In the chapter on Development it | not so rapidly fatal in the kitten as it is
will be explained how it is that inter- | in the adult cat.
ruption in the process of respiration 1s e

CHAP. viII.] ORGANS OF RESPIRATION AND SECRETION. 221

gives out oxygen and takes in carbonic acid. Internal respiration,
therefore, is the absorption of oxygen and the elimination of carbonic
acid by the ultimate parenchyma of the body’s substance, which is
bathed by the nutritious oxygenated fluid as it exudes from the
capillary vessels. External respiration is the absorption of oxygen,
and the elimination of carbonic acid by the blood, on what is
essentially the surface of the body ; for the lining of the lungs is but,
as it were, a very deep and complex inbending and infolding of the
body’s external surface, as has been already poimted out in the
second chapter. The oxygen thus received in the lungs, appears in
part to form an actual chemical union with the matter of the red
corpuscles, and in part to be dissolved in the hquor sanguinis. The
elimination of carbonic acid, it is maintained, is produced by an
actual process of chemical decomposition.

It is necessary that the air respired be more or less fresh, and it
cannot be used over and over again an indefinite number of times ;
for al] that some oxygen still remains within it. |

Ordinary atmospheric air contains nearly 7,900 parts of nitrogen
and 2,100 of oxygen, with a small quantity (3 parts in 10,000) of
carbonic acid.

The air expired, however, has about 470 parts of carbonic acid,
and less than 1,600 parts of oxygen—the quantity of nitrogen
remaining about the same as in fresh air. Thus about 5 per cent.
of oxygen is gained, and 5 per cent. of carbonic acid is lost in the
process of respiration. These changes correspond with changes in
the blood. Thus, im 100 parts of venous blood there may be five
parts of oxygen and twenty-five of carbonic acid, while in the same
quantity of arterial blood there may be ten parts of oxygen and
twenty of carbonic acid. 3

However rich in oxygen the air inspired may be, no more oxygen
is absorbed than the processes of life demand. The organism
regulates itself in this respect. The more the blood is charged with
carbonic acid, the greater is the quantity given off in the lungs.

If, instead of nitrogen, hydrogen or marsh gas be mixed with
oxygen in due proportion, and breathed, the compound can be
respired for an indefinite time. Some gases, however (such as
hydrochloric acid, sulphurous acid, ammonia, chlorine, fluorine, and
others), cannot be respired, because their action is so irritating to
the breathing organs that the entrance to the windpipe becomes
involuntarily closed against them.

Other gases can be respired, but are poisonous if they are
respired. Such are sulphuretted hydrogen, phosphuretted hydrogen,
nitric oxide, carbonic oxide, and some others.

If pure oxygen be respired, it removes the carbonic acid from the
blood too rapidly, so that the blood thereby ceases to possess a
necessary element for effecting the respiratory changes. ‘The result
of this is death by what is called apnea. Death produced by
absence of oxygen, is called asphywia.

The gaseous interchanges which take place in the lungs, are not

222 THE CAT. [CHAP, VIII,

effected immediately by the fresh air last taken in, but only by it
after it has become diffused (according to the laws of gaseous —
diffusion) through the stationary air previously respired. It is
effected by this stationary air because, as we shall shortly see, only
a small part of the air which the lungs contain, is mtroduced or
expelled at each respiratory movement. This stationary air is then
the direct agent in effecting the exchange, and it is on this account
that the air last expelled in each act of expiration, is the part most
loaded with carbonic acid. Thus both external and internal
respiration are processes which go on continuously, and without
any such intermissions as those which take place in that alternating
action which popularly goes by the name of “ breathing,” but
which is merely a process of introducing into the body that material
by which respiration, or true “ breathing,” can be effected.

§ 2. The process of respiration in the cat is something more than
this mere interchange of gases, since whatever be the dryness of
the air inspired, the air given forth in its breathing is nearly
saturated with moisture, so that much water is thus given out from
the body daily. Moreover, however cold may be the air taken into
the body in breathing, the animal’s breath as it 1s given forth is
always hot, having become heated by the internal heat of the body.
This heat is due to a process of chemical change taking place, as
lately mentioned, in the innermost parenchyma of the body. Now,
wherever chemical combination takes place, heat is evolved, and
therefore those intimate processes of life which are effected by
internal respiration have been described as a sort of slow combustion.
External respiration then is the indirect cause of the heat of the
cat’s body, as may be shown by the increase of heat produced in it,
by increased rapidity of breathing. Nevertheless, that it is only an
indirect cause, 1s proved by the fact that the body may not only
continue warm for some time after death, but that, under special
circumstances, its temperature may temporarily increase.

_ This process of heat generation can go on as long as food is
supplied, and the temperature of the body can be maintained at an
even heat of about 100° Fahr., in spite of a very low external
temperature in the winter season. The animal thus being always
‘“‘ warm-blooded.”

By these chemical changes in the recesses of the tissues, not only
is nutrition effected, but also the waste products of the wear and
tear of life are removed by the introduced oxygen decomposing those
products and converting them into soluble erystalloids or into gases
—changes which enable them either to pass out readily at the lungs,
or else through the skin or through organs hereafter to be described,
namely the kidneys.

The function of respiration as generally understood, é.e., external —
respiration, 1s effected by a certain set of organs, which form two —
categories. The first category includes the accessory organs of
yvesptration, or parts which convey air into the body, and which again
expel it when it has done its work. The organs of the second

CHAP. vilI.] ORGANS OF RESPIRATION AND SECRETION. 223

category, or the essential respiratory organs, are those which place
the blood in intimate relation with the imspired air. To the first

category belong the windpipe, and the grosser structure of the
_ Jungs, with the muscles and other parts which aid in drawing air
inwards and in again expelling it. To the second category belong
the minute cells which form the ultimate and essential parts of the
lungs—the “ air-cells”’ or ‘ alveoli.”

In the cat there is but one real set of respiratory organs; a
certain respiratory action can indeed be also effected by the skin,
but its amount is so minute it may be practically disregarded.
Water ordinarily contains atmospheric air mixed up with it, but
_ the cat has no organs by which the air thus contained can be
respired, either by the external skin or by the lungs: for if water be
introduced into the latter its introduction causes death, as also does
the continued immersion of the whole skin in water. Nevertheless,
as we shall see, the actual respiratory surface—the inner surface of —
the lungs—is always moist, and bathed with a thin watery film.

§ 3. The tube by which air is introduced into the cat’s body is
the windpipe, or trachea, which is relatively very capacious, and
opens anteriorly in the back of the floor of the mouth, while pos-
teriorly it divides into two branches, each of which is called a
bronchus, and penetrates into one of the two lungs. Atits front end
the trachea expands into a membranous and cartilaginous box-like
structure called the darynz, and it is the laryax which opens into
the mouth behind the root of the tongue. The trachea passes
downwards and backwards down the neck and along the thorax on
the ventral side of the cesophagus. It remains permanently hollow,
like an artery, its cavity being kept open by means of a series of
incomplete cartilaginous rings which surround the windpipe im
front and at the sides, but do not extend into its dorsal wall (ad-
joining the cesophagus), which is soft. The ventral surface of its
hinder half is in contact with this thymus gland.

Its lower end lies above the sternum and the arch of the aorta.
Above the pulmonary artery, the trachea divides into the two
bronchi. The right bronchus is short, and passes horizontally into
the root of the nght lung. The left bronchus is somewhat the
longer, and passes to the left lung behind the arch of the aorta.
Within the lung the bronchi divide and subdivide, like the branches,
branchlets, and twigs of a tree.

The cartilages of the trachea are forty-five in number, and are
held in juxtaposition by fibrous membrane which embeds them.
The highest cartilage is connected with and underlies the larynx.
The soft layer which completes the trachea above, where the carti-
laginous rings are incomplete, contains organic muscular fibres,
internal to which is a stratum of elastic fibres which extend thence
all round within the cartilages. More internally the tube is lined
with mucous membrane, covered on its surface by a columnar and
ciliated epithelium.

The bronchi have the same structure as the trachea, except that

224 UTE OAT - [CHAP. VIII.

their cartilaginous rings are shorter and narrower. The smaller
tubes, into which the bronchi subdivide within the lungs, are called
bronchia.

§ 4. The tunes (Fig. 89 and 112) are two in number, and are
placed one on each side of the heart in the thorax. Together with
the heart they fill up the main part of the whole thoracic cavity.
They are attached each by a small part of its inner surface (called
its root) to one of the two bronchi and to the great vessels con-
necting that lung with the heart—the blood-vessels and air-tubes
entering or leaving the lung, passing through one or other of its

“roots.” From this attachment each lung hangs freely suspended, |

being conical in shape, with a broad, concave base, which is applied
to the front surface of the diaphragm. Each lung is enclosed in a
serous, shut sac, called a p/ewra, and the two pleure together may
be said to form the proper serous sac of the thorax, though each is
quite distinct from the other.

The two pleuree line the right and left halves of the thorax, and
are reflected over the two lungs at their roots respectively. In this
way the two adjacent (inner) sides of the two pleure traverse the
thorax from above downwards.. They are not, however, in contact.
but separated by two interspaces termed mediastina.

The anterior mediastinum contains the heart in its pericardium.

The posterior mediastinum contains the cesophagus, the aorta, the
vena azygos, and the thoracic duct, together with the two nerves
called pneumogastric.

Each lung is divided by fissures into lobes as follows:

The left lung is divided by a deep fissure in two large and
distinct lobes sub-equal in size (Fig. 104, ° and ®). A less deep
fissure also separates off a small lower portion (a) of the upper of
the two lobes of the left lung. The right lung is divided by three
deep fissures into four unequal and distinct lobes, the uppermost of
these (Fig. 104, !) is large and triangular. The next (*) is narrow
and elongated, but much smaller. The third lobe (°) is the largest
of all, and has on its inner side the fourth lobe, which is incompletely
divided by a fissure into a larger external part (*) and a much
smaller internal portion (4a), both of which are narrow and pointed at
the end.

As to their minute structure, the lungs consist of a prodigious
number of small air-bags, called “lobules,” attached to the finer
ramifications of the bronchi. These lobules are united together by
connective tissue with blood-vessels and muscular and elastic fibres,
and can very plainly be discerned at the surface of the lung. The
lungs may therefore be described as spongy and highly elastic
organs which (when once respiration has taken place) will float if
thrown into water, and which, if artifically inflated after removal
from the body, will spontaneously contract and expel the air so
introduced, through the elastic nature of their substance.

The smallest bronchial ramifications cease to be lined with ciliated

epithelium, and have squamous epithelium instead.

CHAP. vil.] ORGANS OF RESPIRATION AND SECRETION. 225

Each bronchial tube, while still cylindrical, enters one of the

lobules and there ramifies, its ramifications ultimately dilating into
a larger passage called an infundibulum, the walls of which are
beset with numerous little sac-like dilatations, called air-cells, alveoli,
or pulmonary vesicles. ‘These are naturally filled with air, and their
membranous walls are strengthened with elastic and some muscular
fibres, and beset with a multitude of delicate capillary vessels, which
expose the blood they contain to the action of the air in the alveoli.
The arteries (carrymg the venous blood for oxygenation) end in
minute twigs, which surround the margins of the alveoli, whence
the capillary vessels extend inwards, and are subjected to the air on
both sides of the moist, delicate membrane in which they ramify.
The minute veins which issue from the capillaries, and which carry
arterial blood, do not run side by side with the arteries, but, pur-
suing a different course, frequently anastomose and increase in size
till they end in the great pulmonary veins, which proceed through
the roots of the lungs to the left auricle, as before described.

Besides the pulmonary arteries (which bring blood for respiration),
the lungs have their own proper arteries and veins, which are
concerned in their nutrition. These are the bronchial arteries and
veins, and they are smaller than the other blood-vessels of the lungs—
the pulmonary arteries and veins.

The bronchial arteries are derived from the aorta, and follow the
divisions of the bronchi within the lung. The bronchial veins unite
together to pass out at the roots of the lungs.

§ 5. The MECHANISM OF RESPIRATION has already been slightly
noticed, in the fifth chapter, in relation to the action of the
diaphragm and intercostal muscles, which serve, by their alternate
contraction and dilatation, to modify the capacity of the thorax.
The serrati postici muscles, by drawing backwards the ribs to which
the diaphragm is attached (at the very time that the other ribs are
being drawn forwards, and the diaphragm, by its contraction,
rendered less convex) aid in temporarily enlarging the thoracic
cavity, and so causing an influx of air into the lungs. In this action
the serrati antici and scaleni also give aid by drawing the anterior
ribs forwards.

The pumping action of the diaphragm is the main agent in
respiration, the relaxation of its fibres allowing it to become convex
anteriorly, and so encroach upon the thoracic cavity—air being
necessarily driven out of the lungs thereby. But the expulsion of
airin expiration is largely due to the highly-elastic nature of the
pulmonary structures (which has been already pointed out),* and to
the muscular contraction of the bronchi. The abdominal muscles
however are also called into play to effect a forcible expiration.

* It is owing to this elasticity that if ; atmospheric pressure on their outer sur-
a perforation be made in the wall of the | face; from which pressure, the un-
thorax, the lungs will contract greatly. | injured thoracic wall before protected
For by such injury the atmospheric pres- | them.
sure within, becomes neutralized by

226 THE CAT. [cHar, vit.

The alternation of acts of inspiration and expiration (one of the
former commencing the series at birth, and one of the latter
terminating it at death) goes on unceasingly, but at a rate which
varies according to circumstances—being most frequent during
violent exertion.

What is called the rvspiratory rythm consists of three parts:
(1) the act of inspiration ; (2) that of expiration, which endures
but little more than half as long as the former; and (8) an interval
of rest, which is much shorter than either.

Inspiration aids the circulation indirectly by pressing on the great
vessels, the difference between the strength of the walls of the
arteries and veins causing the pressure to be no impediment to the
former, while the same pressure aids the flow of the blood in the
latter.

APPLICATIONS OF THE RESPIRATORY ACTIONS produce a number
of familiar actions, such as yawning, which is a prolonged inspira-
tion ; coughing and sneezing, which are sudden acts of expiration,
the former being preceded by a prolonged inspiration—the air
passing out by the mouth. In the latter it passes out only through
the nose. All forms of mewing, howling, and other vocal manifesta-
tions, are modified expiratory actions.

The term viraL capacrry refers to the capacity of the lungs as
estimated by the greatest quantity of air which can be expelled
from the lungs by the most forcible expiration after they have been
inflated by the deepest inspiration. But no expiration, however
violent or prolonged, will. nearly expel the air which the lungs can
be made to contain—while in ordinary respiration but a very small
part ebbs and flows.

This small quantity is called the breathing or tidal air. That
which always remains and can never be expelled is called the
residual air; that which ordinarily remains in the lungs after
expiration, but which can be expelled, is called the reserve or sup-
plemental air, and that which can be drawn in by a prolonged
inspiration, beyond that ordinarily so taken, is termed the com-
plemental air. These phenomena have been accurately observed
only in man, but the essential conditions are the same in the cat.

§ 6. It has just been said that all vocal manifestations are
modified expiratory actions; but these actions, in order that they
should produce sounds, need the aid of a peculiar mechanism. This
mechanism is furnished by that expanded, anterior end of the
windpipe which has been already referred to as the LARYNX.

To the upper, anterior margin of the larynx, the hyoid bone is
attached, and therefore also the tongue, behind the root of which is
the laryngeal opening into the pharynx—the “ glottis ””—already
spoken of as situated in front of the cesophageal opening, and as being
protected by that cartilaginous process the epiglottis, which stands
up in front of it. The larynx is formed of three large and two small
cartilages, united together by fibrous tissue moved by muscles, and
supplied with blood-vessels, lymphatics, and nerves, the whole structure

_.margin, and are widely separated from

CHAP. VII.] ORGANS OF RESPIRATIUN AND SECRETION. 227

being lined with mucous membrane, which is supplied with numerous
mucous glands. Amongst the parts formed of fibrous tissue are

two internal ligaments on each side of its cavity, called the vocal

cords, which are the immediate agents in the production of the
voice. The whole of the inside of the larynx below these cords
is coated with ciliated epithelium, and also for a short distance
above them. The action of the cilia is to
propel the mucous secretion iowards the
upper aperture of the larynx.

Of the CARTILAGES OF THE LARYNX,
three are median, azygos structures, and
the others are arranged as a pair.

The largest of the three median struc-
tures is called the thyroid cartilage, which
consists of two lateral parts (a/e) united
at an acute angle or sharp curve, opening
backwards—.ec., dorsally. Each ala is
somewhat quadrilateral (an elongated paral-
lelogram) with its anterior (ventral) border
(where it joins its fellow of the opposite
side) the shortest, while its posterior border
is prolonged upwards and a little down-
wards, into two rather blunt processes
termed cornua. The two posterior borders
are nearly vertical, with an undulating

one another. The inferior margin of each _ Fig. 106,.—Vrew oF THe Ricet
= bs 2 = SIDE OF THE CARTILAGES OF THE

ala 1s concave in front of the IMMETIOT Sguers Lueeia aes alae ee

cornu, while more anteriorly it is slightly ®ss serararep.

convex, and then concave, so that there is ——- Th¢ uhpermost is the epiglottis

é).
a slight median notch at the under border —_%. Is the thyroid, and (¢) is its
‘ superior cornu. The small

of the thyroid. The superior margin of cartilage, below is one of the
tenoids, with an articul

each ala is also concave in front of the surface fur the taiceialonant

superior cornu, while more anteriorly it is Be Se ee ae

strongly convex, there being no notch at Beneath is the cricoid (cr , with
the articular surface for the

the point where the upper margins of arytenoid indicated imme-

j , diately beneath the repre-

the two alse meet together in front. Each Bee ee ee ae
ala is smooth and rather concave within, lage.

1, 2, 3, and *, are the four upper-

from .above downwards. ‘The superior most rings of the trachea.
cornua are connected by a ligament called
the thyro-hyoid hgament, with the tip of the thyro-hyal of the
same side. They are also closely connected, through the medium
of the thyro- and cerato-hyals, with the stylo-hyals. Each inferior
cornu articulates with the outside of the cartilage to be next de-
scribed. It is much shorter than the superior cornu.

The cricoid cartilage is rmg-shaped, and may be considered as the
modified, topmost cartilage of the trachea. Greatly modified it
certainly is, since, instead of being defective behind, as are the

tracheal cartilages, and as is the thyroid cartilage, it is much larger,
: Q 2

q

228 ‘THE CAT.

and more developed behind than elsewhere. Its lower border is

slightly undulating, and is connected by membrane with the upper-

most cartilage of the trachea. Its convex upper posterior border
has a scarcely perceptible median notch, and on each side of this is
an oval, convex, articular facet. Internally this cartilage is lined by
the mucous membrane of the larynx.

The third median cartilage is the epiglottis, which is acutely
pointed above and very obtusely so below, where it is attached by
ligament to the inside of the thyroid. The posterior (dorsal) surface
of the epiglottis 1s concave from side-to side. Vertically, its anterior
(ventral) aspect is concave above and convex below (Fig. 106). It
is invested with mucous membrane both in front and behind, except

Fig. 107.—Tar LARYNX AND GLOTTIS OF THE CAT.

A. Aperture of the glottis contracted. | D. Vertical section through the trachea and
B. The same dilated. | oesophagus.

C. Opening into the larynx. a, ac, e, and fu, as in figure C.
a. Arytenoid cartilages. Between ac and v is the ventricle of the

ac. False vocal cords. larynx.
e. Kpiglottis. er. Cricoid cartilage cut through.

jv. Crico-epiglottic liga::ents. @. Gisophagus.
v. True vocal cords. t. Trachea.

the lower part of its front surface, where it is attached to the tongue
and hyoid by ligaments—that which connects it with the hyoid being
elastic. It is connected on each side by a strong fold with (Fig.
107, fv) the side of the cricoid cartilage close to the base of the
arytenoid cartilages.

The two arytenoid cartilages rest each on one of the two oval
articular surfaces before mentioned as situated one on each side of
the median posterior notch, in the upper border of the cricoid
cartilage. Hach arytenoid cartilage is irregularly pyramidal in
shape, the base of each pyramid resting on the cricoid. The summits
of the arytenoid cartilages curve somewhat towards each:other.

A good many Uigaments connect the different portions of the
larynx. Thus there is the thyro-epiglottic and hyo-epiglottic con-
necting the epiglottis with the thyroid and os hyoides respectively.

[CHAP. VIII.

‘ = ——
SC

CHAP. viI.] ORGANS OF RESPIRATION AND SECRETION. 229

The aryteno-epiglottic, which might be called “ crico-epiglottic,” 1s a
thick fold of membrane (Fig. 107, fv) which proceeds from the base
of the outside of each arytenoid and contiguous part of the cricoid, to
the side of the epiglottis. The thyro-hyoid connects the os hyoides
with the thyroid, while the crico-thyroid connects the latter with the
ericoid, filling up the interval between them and containing much
elastic tissue.

The most important ligaments, however, are these called the
“vocal cords,”’ of which there are two kinds on either side of the
cavity of the larynx. The seperior or false vocal cords—called also
the superior thyro-arutenoid ligaments—are folds of membrane which
pass (one on each side) from the anterior aspect of the arytenoid
cartilages downwards and forwards to the mucous membrane of the
middle of the posterior (dorsal) surface of the epiglottis and thyroid
(Fig.107,ac). These are very prominent folds of membrane, and it
is by their vibrations that the sound of “ purring” is said to be
produced. |

The inferior or true vocal cords—called also the mferior thyro-
arytenoid ligaments—have a similar but lower origin and insertion
to the false vocal cords (Fig. 107, ) ; they are less prominent and
sharply edged. It is these true vocal cords which by their vibra-
tions are said to produce the mewing and howling sounds. These
cords leave between them an aperture termed the rima glottidis, and
they tend to form a horizontal partition dividing the cavity of the
larynx into an upper (anterior) and a lower (posterior) portion.
The whole larynx opens into the pharynx by its superior aperture—
the glottis—which is bounded in front by the epiglottis, behind by the
arytenoid cartilages, and on each side by the aryteno-epig!ottidean
folds, and by the false vocal cords. Between the false and true vocal
cords of each side is a small depression called a “ ventricle.” These
two depressions, however, are so slight as hardly to deserve notice.

§ '7. The vorce is produced by the vibration of the edges of the
vocal cords (when stretched and approximated), which vibration is
effected through the passage outwards of a stream of air, according
_ to the laws which regulate the vibrations of strimgs and membranes
Accordingly, certain muscles act upon the arytenoid cartilages, and
by their action put the membranes on the stretch, and so alter
the shape of the opening of the glottis by contracting it (Fig. 107,
A & B). The more the cords are stretched, and the narrower the
aperture, the shriller are the sounds emitted.

Though the vocal cords are the main agents m the production of
sounds, the tone and qualities of these sounds are modified by shape
of the cavities of the larynx, pharynx, and even of the air-cavities of
the skull, and by the physical qualities of all these parts. To effect the
needful changes, appropriate motor agents are needed, and there
are no less than eight pairs of laryngeal muscles. The crico-thyroid
muscles extend from the upper border of the cricoid to the outside
of the thyroid and its lower cornua. Their action is to rotate the
thyroid downwards and to stretch the vocal cords. Two pairs of

230 THE CAT. [CHAP. VII.

muscles—posterior and lateral crico-arytenoids—pass from the ericoid
to different parts of the arytenoids, which the former rotate out-
wards, and the latter inwards, thus either widening or contracting
the glottis. Thethyro-arytenoids and the artyeno-epiylottidean muscles
have the same connexions as the true vocal cords and the aryteno-
epiglottic ligaments respectively. The glosso-epig/ottidean muscles
pass from the back of the tongue downwards to the base of the
front of the epiglottis, and the hyo-epiglottidean muscles are very
small ones, extending from the hinder surface of the basi-hyal, down
to nearly the same part of the epiglottis as that into which the last-
mentioned muscles are inserted.

Lastly, the arytenoid muscles connect and tend to approximate the
two arytenoid cartilages.

§ 8. In treating of respiration and the respiratory organs, we have
mainly been occupied with that which ministers to the nutrition and
warmth of the body by enabling it to obtain its due supply of oxygen.
We have, however, also noted that the process of respiration 1s in part
a process of elimination and removal from the body of a portion of the
waste products of its vital activities. This now requires more careful
consideration. Life is aseries of compositions and decompositions,
and in order that assimilation may go on, a process of disassimilation
must necessarily accompany it. With the addition of new and unused
material, there must go on a subtraction of old and effete material, and
this (as we have lately seen) is mainly brought about by a process of
oxydation in the inmost parenchyma of the body. We have seen,
in studying alimentation, that colloids have to be changed into
erysialloids, that they may be conveyed to the colloidal parenchyma,
into which they have to be transformed. Similarly in the process of
disassimilation. the effete colloidal parenchyma has to be reconverted
into crystalloids that it may be conveyed away and excreted, though
the crystalloids of excretion are generally different from those of
nutrition.

It has also already been pointed out that the digestion of the
food is aided by the juices of the salivary glands and pancreas, and
other similar structures. Now these juices do not exist as such in
the blood, but are formed from it by a mysterious power which
certain cells possess thus to form new products. ‘The exercise
of this power is called “ secretion,” and it is a power analogous
to that by which the various tissues are enabled to add to their
own substance from the life-stream which bathes them, though
their substance does not exist, as such, in that stream. Thus
‘‘ assimilation” is a sort of ‘‘secretion.”’ Nevertheless it cannot be
said that “ secretion ” is a sort of “ assimilation.” ‘“ Assimilation ”’ it
a process of forming products and adding them to the body; bus
‘secretion’ is a process of forming products which are to be got rid
of, or are destined to aid in other life processes. Thus secretion 1s a
special function, and as such has a special organ—a gland. Glands,
as we have already seen, are either simple or complex imvolutions
of an epithelial surface. We have seen simple ones in the sweat

nar. vit.) ORGANS OF RESPIRATION AND SECRETION. 231

and mucous glands, and complex ones in the salivary glands, the
pancreas, and above all, the liver. The foldings or subdivisions of
a gland are manifestly but a convenient mode of augmenting the
secreting surface within a small space. Since all secretions are

Fig. 108.—D1aGRAM OF DIFFERENT FORMS OF GLANDS, SHOWING HOW THE SECRETING SURFACE
MAY BE AUGMENTED, AND THE GLANDULAR STRUCTURE RENDERED MORE COMPLEX BY
INVERSION OR RECESSION OF THE SURFACE TO A GREATER AND GREATER DEGREE.

A. Simple glands. m. The entire gland, showing its branching
g. Straight tube. duct and lobular structure.
h. Sae. nm. A separated lobule, with one branch of
t. Coiled tube. the duct (0) proceeding from it.
B. Slightly more complex forms. D. Compound tubular gland.
k. Tubular. Secreting surfaces may also be increased by
l. Saccular. projections and foldings outwards, analogous
C. Racemose or compound saccular gland to these inversions and foldings inwards.

formed from the blood, every secreting surface, and therefore every
gland, must be highly vascular. Itis as yet quite unknown what
causes different epithelial cells to have the power of forming such

ee A Md et

ee ee

232 THE CAT. [cuAP. vi.

different secretions as are those, for example, of the sweat glands,
salivary glands, synovial membrane, and liver. The undivided tube
of a gland by which its secretion is poured out is its duct. The se-
cretions, and therefore their glands may, as we have seen, simply
serve to aid the process of assimilation. They may also aid the
function of generation, or, finally, they may merely serve for ex-
cretion, 7. ¢., to get rid of waste products or excreta. Certain large
and small glands have already been described in the sixth chapter,
namely, the liver, the pancreas and the various salivary glands.
The anal glands were also therein noticed. It remains to describe
those very important glands, the kidneys.

§ 9. As the foods and the tissues of the body mav both be
divided into mitrogenous and non-nitrogenons substances, so also
the excreta of the body may be similarly divided. The non-

Fig. 109..-_Tue Cat’s KIDNEY, ENTIRE AND IN SECTION.

A. The outer surface of the kidney, showing the | 7, Expanded end of the calix surrounding
network of blood-vessels. the mammilla.
a. Renal artery. o. Dark spots in cortical substance.
u. Ureter. p. Papilla, or mammilla,
v. Renal vein. ol. Pelvis.
B. Vertical section through the kidney. t. Tubules of the kidney.

c. Cortical substance.

nitrogenous products of waste are eliminated by the lungs, and to a
very much less degree by the skin in the form of water and carbonic
acid. But a very large portion of the waste products are nitrogenous.
These are eliminated in a trifling degree also by the skin, but the
special organs for their elimination are the renad organs or kidneys.
A process of oxidation in the innermost substance of the body
converts the nitrogenous waste matter into wrea, uric acid, ammonia,
and certain other acids and salts which are crystalloidal derivations
from colloidal tissues. The kidneys extract all these, with much
water, from the blood, and so form urine.

§ 10. The x1pneys differ from the lungs in that they are organs
of excretion only. The lungs excrete, but as we have just seen, they
also take in. The secretion of the kidney, the urine, passes down
from those organs by two tubes into a receptacle—the bladder—where
it accumulates, and whence it is expelled at intervals.

The kidneys are two organs placed one on either side of the

CHAP. vut.] ORGANS OF RESPIRATION AND SECRETION. 233

vertebral cotumn, a little behind the attachment of the diaphragm
(Fig. 105) They le against the dorsal wall of the abdominal
cavity above (i.e., the dorsal side of) its peritoneal linmg. The
anterior end of the right. kidney adjoins the posterior surface of the
liver. The left kidney is in proximity to the spleen.

Each kidney is a rounded body, smooth externally, and showing
superficially an arborescent network of vems (Fig. 109, a.) It is
convex everywhere, except on its inner side, where it presents a
marked concavity. From the middle of this concavity a tube, called
the ureter, proceeds inwards and backwards to the bladder (Fig. 105,w).
This tube is the duct of the renal gland, and it emerges from a
fissure in the concave surface, called the hidus of the kidney. From
this hilus the renal vein (Fig. 109, a, v) also issues, and into it the
renal artery (w) and the nerves enter. The artery enters on the
dorsal side of the emergence of the vein.

As to its structure, the kidney consists of an immense multitude
of minute tubes, with vessels, nerves, connective tissue and fat, all
enclosed in a thin but firm fibrous coat, which closely invests the
gland and contains elastic fibres. )

On making a longitudinal section of the kidney it is seen to be of
a more or less red colour and to contain a heart-shaped cavity
(Fig. 109, 3s, p/) towards its imner border. Its solid substance
appears divisible into an external layer of a lighter tint, containing
minute dark red spots (0)—the cortical substance—while the rest
is darker coloured and forms what is termed the medullary
substance. a

The cavity above referred to is the continuation inwards of that of
the duct of the gland (the ureter), and 1s called the pelvis (pl). As
the pelvis penetrates the gland it enlarges (7) and surrounds a
central prominence which projects into it. The part surrounding
this prominence is called the calix.

The cortical substance forms one continuous layer, and the
medullary substance is also arranged in a conical mass or pyramid,
the apex of which is directed inwards and projects into the calix as
the mammilla or papilla (p), the tubes of which it is composed (¢)
converging to the mammilla.

The pelvis is lined with mucous membrane, which is reflected
over the apex of the mammilla.

The minute tubes (¢) of which the kidney is mainly composed are
called TUBULI URINIFERI. They are very closely packed, and
consist of a transparent membrane lined with a polygonal or a
spheroidal and glandular epithelium occupying two-thirds of their
diameter. These tubuli open on the surface of the mammilla,
whence they pass into the substance of the kidney, dividing and
subdividing, but continuing a nearly straight course till they come
to the cortical layer, where they become much smaller in size and
variously contorted in all directions, whilst they freely anastomose.
Scattered about in the cortical substance are small capsules (the
red specks already spoken of) or Malpighian corpuscles. These are

234 j THE CALS. [cuap, vam,

the expanded terminations of the contorted uriniferous tubes. Fach
such corpuscle contains a bunch of minute looped capillary vessels,
forming what is called a glomerulus (Fig. 110, h), and has itself a
most delicate epithelial lining contrasting with the thick spheroidal
lining of the uriniferous tubes. A small artery enters each glome-
rulus, and there breaks up into a number of minute branches endin

in a capillary network, whence a small vein (Fig. 111, e’) arises,

Fig. 110.—SEMI-DIAGRAMMATIC REPRESENTATION
or A MALPiIGHIAN Bopy IN ITS RELATION
TO THE URINIFEROUS TUBE. MAGNIFIED .
300 DIAMETERS. Fig. 111.—D1acrRam sHOWING THE RELATION

Ure vs : MALPIGHIAN Bopy To THE URINI-
. Capsule of the Malpighian body continuous etiiveae sid
with (b), the membrana propria of the coiled FEROUS Ducts AND GLOOD-VESSELS.

Q

uriniferous tube. a. One of the arteries.
¢. Epithelium of the Malpighian body. a’. A branch passing to the glomerulus.
d. Epithelium of the uriniferous tube. c. Capsule of the Malpighian body.
e. Detached epithelium. t. Uriniferous tubes.
f. Afferent vessel. e’,e. Efferent vessels, which subdivide in the
g. Efferent vessel. plexus (p), surrounding the tube, and finally
h. Convoluted vessels of the glomerulus. terminate in the branch of the renal vein (¢).

which leaves the glomerulus, and breaks up into another network
or plexus (Fig. 111, p) of capillaries surrounding the tubules,
whence arise other veins, which convey the blood ultimately to the
renal vein. Thus we have in the kidney a multitude of minute
special circulations, each of which is analogous to the portal system
or that of the coronary vessels of the heart.

The Function of the kidney is, as has been said, to remove
nitrogenous waste products and salts from the blood by the secretion
and excretion of urine, and it thus supplements the action of the
lungs by the removal of matters which escape the action of the
pulmonary organs. The blood comes, as we have seen, to the
kidneys direct from the abdominal aorta, and is therefore as pure
as when it leaves the left ventricle. In circulating through the
kidney it is still further purified, namely, from its nitrogenous waste
matters, and it also loses more carbonic acid by the formation of
urine, than it acquires by any wear and tear of the tissues of the
gland. ‘Thus the blood which leaves the kidney is at its maximum

CHAP. vur] ORGANS CF RESPIRATION AND SECRETION. 235

of purity and oxygenation, and is as bright and scarlet as when it
: entered it.

| The watery substance of the urine appears to drain from the
| vessels of the glomerulus into the cavities of the Malpighian cor-
puscles, and its more solid constituents to be secreted by the thick
epithelium of the tubules.

Some of the constituents of the urine—such as urea, uric acid,
and a substance called kreatine—already exist in the blood which
comes to the kidneys, and their elimination therefore is rather an |
excretion than a true secretion; not but what it may be doubted
whether any such a purely passive and physical process as a mere
straining-off action, really takes place in the living organism at
rall.*

The action of the kidney is constant, and small quantities of
urine are continually passing from the mammilla of each kidney to
the pelvis, and thence, down the ureters, into the bladder.

§ 11. The vRETERs are, as has been already explained, two ducts
or tubes which proceed one from the pelvis of each kidney. They
lie on the dorsal side of the peritoneum, and proceed inwards and
backwards to the bladder (Fig. 105), being connected by loose
areolar tissue to the parts adjacent to them.

They enter the wall of the bladder very obliquely, opening within
it each by a narrow, slit-hke aperture, the margins of which are
somewhat thickened so as to have a valvular action and check the
reflux of urine from the bladder into the ureters.

Each tube consists of a canal of mucous membrane, lined with
epithelium ; the mucous tube being invested with organic muscular
fibres, which are again invested externally by connective and elastic
tissue.

§12. The siappEr (Figs. 105 6 and 115), is a hollow, rounded
vessel with three openings, two (those of the ureters,) by which the
urine is received, and one (that of the urethra,) by which it is
discharged. These three apertures define a triangular portion of the
bladder called the trigone.

The bladder is connected with the anterior wall of the abdomen,
at the umbilicus, by a fibrous cord called the wrachus, which is the
remnant of a fcetal structure, and at least occasionally includes
a small irregular internal cavity lined with epithelium.

The bladder is also attached to adjacent parts by folds of peri-
toneum and of fascia. The inside of the bladder is lined with
mucous membrane invested with squamous epithelium. The mucous

male. The urine of all the species of the

* The pungent, and to most persons,
disagreeable odour of the male cat is
notorious. Yet it must be due to causes
other than those which determine the
— essential function of renal secretion, since
it is absent from the urine of the female
cat, and also from that of the castrated

cat family has (as far as known) a more
or less powerful and disagreeable smell,
but its odorous qualities differ much in
different species, as the author has been
assured by Mr. A. D. Bartlett. .

es oe Ue

236 THE CAT

lining is loosely attached to the outer coats of the bladder and is
therefore thrown into folds when the viscus is empty. . |

The outer coats of the bladder are muscular and fibrous. Its
muscular coat is formed of organic fibres in several layers. Its

Fig. 112:—PortTion or THE NECK AND THORAX OF A KITTEN, DISSECTED TO DISPLAY THE |
LARGE THYMUS GLAND.

a. Right auricle of heart.
ca, Carotid artery.

U. Larynx.

ig. Lung.

pn. Pheumogastric nerve.

t. Trachea.

tg. Thyroid gland.

ty. Thymus gland.

v. Ventricle.

i vea. Vena cava anterior.

fibres are all so arranged as to remind us of figures of 8. They
extend in almost every direction, and intersect each other on the
front and hind surfaces of the bladder. Towards the orifice leading

Bae ond

cHAP. vill.] ORGANS OF RESPIRATION AND SECRETION. 237

to the urethra the fibres assume a circular course, and so form a
somewhat dense mass called the sphincter of the bladder.

External to the muscular coat is the fibrous investment of the
bladder.

The passage by which the urine passes from the bladder to the
exterior is named the wrethra.

The urine is expelled by contraction of the muscular coat and
relaxation of the sphincter, and is aided by contraction of the
abdominal muscles and diaphragm and by a small muscle called the
accelerator urine (Fig. 115, *).

§ 18. The sUPRARENAL CAPSULES are two small roundish, somewhat
flattened bodies (Fig. 105, sv), situated one in the vicinity of the inner
part of the anterior end of each kidney, being attached there by
areolar tissue. Hach consists of an outer cortical part, of a firm
consistency and yellow colour, and an inner softer and darker
medullary portion. It has a fibrous investing membrane intimately
connected with the cortical substance, which is made up of delicate
filamentous tissue with interspaces filled with granular matter,
nucleated cells and oil globules. These organs are richly supplied with
nerves, but they have no duct, and their function is quite unknown.

§ 14. The THyroiD Bopy or gland is another ductless structure of
unknown function. It is very vascular, of a soft consistency and
reddish colour, and lies (Fig. 112, tg) beside the trachea just below -
the larynx. It consists of two lateral parts, each of about the size
of a small bean. There is no median connecting portion, so that
there should rather be said to be two thyroid glands than one. It
is composed of a number of minute, closed vesicles, which contain
a yellowish, glairy fluid, and are connected by areolar tissue ; a thin
but dense layer of which is the external investment. The thyroid
body is supposed by some physiologists to regulate the supply of
blood to the brain, and to prevent undue cerebral pressure by
acting as a collateral blood reservoir.

§ 15. The raymus isa structure which 1s of very large size during
immaturity, but becomes smaller in the adult cat. Like the thyroid
it is a ductless structure of unknown function. It lies on the dorsal
side of the sternum on the ventral aspect of the great vessels, and
extends also far up the neck on the ventral surface of the trachea,
as represented in Fig. 112. It is of a greyish or pinkish colour, and
is soft and pulpy in consisteney. It contains a central cavity,
around which are arranged a number of lobes and lobules made up
of delicate cells. A milky fluid is found within it, containing many
nuclei and small nucleated cells.

§ 16. Other puctLEss GLANDs are the closed follicles which make
up the ‘‘ Peyer’s patches,” and “ solitary glands” of similar nature
have been already mentioned as being found in the intestine. An-
other very small structure of a similar nature is called the “ pitui-
tary body.” It will be hereafter noticed in describing the brain, to
the under surface of which it is attached, lying within the sella
turcica or the dorsum of the basi-sphenoid bone (Fig. 128). Yet

938 tah & THE CAT. | -[oHAP. VIII

other ductless glands are the various lymphatic glands already —
spoken of in the last chapter. |

§ 17. Another viscus, and one of large size, is akin in nature to ~
the lymphatic glands. This is a large ductless organ already men-
tioned as lying im the abdomen in the vicinity of the pancreas, close
to the left side of the stomach. It is called the spLrENn. It is some-
what variable as to shape and size, generally in the form of an
elongated triangle, somewhat bent on itself, of a dark bluish colour,
lying immediately behind the diaphragm. It is convex and smooth
on its left side and concave on the side which is applied to the
stomach, which is marked by a vertical fissure, called the Azlus,
where the vessels and nerves pass into and out from its substance. —

Besides the peritoneum, the spleen is invested with a fibrous and
very elastic coat which, at the hilus, is reflected into the body of
the viscus, forming sheaths and canals for the large blood-vessels

Fig. 113.—THE SPLEEN.

st. Wall of stomach y. Pylorie portion of stomach

and nerves which ramify within it. Thus is formed a highly dis-
tensible framework composed of areolar tissue, with a large quantity
of elastic fibres. Amongst these elastic structures, with their
vessels, is the red pulpy substance.of the spleen. This 1s formed of
nucleated and non-nucleated granular bodies, amongst which are
scattered numerous whitish vesicles, called Malpighian corpuscles of the
spleen, attached like buds to the sides of the minute branches of the
arteries, and each composed of a fibrous bag enclosing granular
nucleated corpuscles.

The Function of the spleen is so far related to alimentation that
the organ begins to dilate while digestion progresses, reaching its
largest dimension after a meal; while later, if no fresh food be
taken, it becomes reduced to its smallest size. A very remarkable
fact, however, about the spleen is that it can be entirely extirpated
without its loss producing any strikingly injurious effect. The
function usually attributed to it is that of helping to replenish the
nutritious fluid by forming lymph cells, which pass from it directly
into the blood. Much obscurity, however, still remains as to the
entire part it plays in the activities of life, and as to what may be
really its main function.

cuap. vur.] ORGANS OF RESPIRATION AND SECRETION. 239

§ 18. We have hitherto considered various organs which could
be classed as alimentary or secreting organs, and some (like the
pancreas, &c.) which were both
alimentary and secreting struc-
tures, since they secreted a fluid
destined to assist in alimenta-
tion. Such secretions, however,
were always destined for the
service of the secreting or-
ganism itself, and to help its
own alimentary processes. But
we have now to consider organs
which are indeed both secre-
ting and alimentary, but which
secrete an aliment for the use
of anuther organism than that
which forms it. These are the
MAMMARY GLANDS, or breasts,
which secrete the milk destined
to nourish the young. Hitherto
we have met with a variety
of organs, but only with organs
which are pretty equally de-
veloped in every individual
cat. The mammary glands,
however, are parts which attain
a large size and perform an
important function, only in one
set of individuals of the species
we are occupied with—namely,
in female individuals. These
glands form a_ considerable
mass, extending on each side
of the ventral surface of the ‘Fig. 114.—Cat’s Mammary GLANDS, WHEN
body, from near the axilla to BUNT PALEY, ACTIVE:
the hinder end of the abdomen. —_™g. Mammary glands. Teats.
Eack gland is invested by
fibrous tissue, which sends in septa (between the various parts of the
secreting glands), accompanied by much adipose tissue. The ultimate
structure of each gland consists of minute secreting cells bound up
by connective tissue into little ‘‘ glandules,”’ each giving out a small
duct, which originates from the cellules and then joins with others
to give rise to larger milk tubes, which ultimately end in certain
conical dilatations or ‘‘ reservoirs,” from which very small excretory
ducts extend forwards to a prominence or nipple, where they open
by minute apertures.

The excretory ducts are formed of connective and elastic tissue,
with an epithelial lining of small columnar cells.

Each nipple is highly vascular, and contains organic muscular
fibres, and its surface is beset with sensitive papille. There are

re

240 THE CAT. (CHAP, VIII.

eight nipples—four on each side, one close to the anterior, and one
near the hinder end of the glandular structure.

These glands become greatly enlarged when in use, especially the
abdominal portion (Fig. 114). In the male the mammary gland is
quite rudimentary, though essentially similar in structure to that of
the female. :

These milk glands may be regarded as greatly enlarged and agere-
gated sebaceous glands, and the milk which they secrete, as a modified
sebaceous secretion. The mix they form is an opaque white fluid,
containing much water, with certain salts of potassium and sodium,
with phosphoric acid, iron, milk-sugar, some albuminous matters
(casein and a little albumen), with fats and some other substances.

The milk being the destined food of the kitten, contains all the
materials needed for the nourishment and growth of the young
animal. It contains in fact a suitable and nicely balanced supply
of nitrogenous and non-nitrogenous, albuminoid, fatty, amylaeceous
and saccharine matters.

§ 19. In the structures last described we have found organs
destined for the nourishment of another individual; but we have
next to consider organs destined for the actual formation of other
individuals. Such are the organs of REPRODUCTION, or gencrative
organs: the business of which is to manufacture, and to render
serviceable certain diverse products which concur in giving rise to
a new living organism, destined with growth to become an animal
like that by which one or other of such products have been secreted.

The products thus formed are essentially of two kinds, and the
faculty of forming one or the other of them constitutes the difference of
sex. It is only by the union of these two kinds of products that a new
cat can be formed, and the process by which that formation takes place
after such a union has been effected, 1s the process of development, the
consideration of which will occupy us im the next chapter but one.

But although the process of development will there be considered,
the nature of generation may be more fitly spoken of here. The
process of growth has been already many times referred to, and
even in the second chapter facts as to the growth of epithelial cells,
of cartilage and bone, were brought before the reader’s notice; and
in the chapter on the organs of circulation, we saw how lymph
corpuscles grow by spontaneous self-division within the substance of
the lymphatic glands. In all these processes of growth, we have,
indeed, already become acquainted with a sort of reproduction, for
it is by the reproduction of the component cells of the various tissues
that their growth is effected. The fact then of an organ secreting
cells which detach themselves in order to perform special functions,
is a fact which has now no novelty for us. Indeed we have met
with a truly complex form of reproduction, in the development
from the milk-tooth’s sac of a bud or off-shoot, capable of growing
into the permanent dental structure by which such milk-tooth 1s
ultimately replaced. Nevertheless, although generation may be
said to be a kind of growth; yet it is a very special and peculiar

kind of growth. By it in the first place is formed a cell capable by

CHAP. viIL.] ORGANS OF RESPIRATION AND SECRETION. 241

self-division and metamorphosis of growing up not into a single
organ only, but into a perfect animal like that which produced 1t.
In the second place, this reproductive cell is formed with reference to
another kind of cell, without the concurrence of which other kind it
is quite unable to perform its own proper function ; while that other
kind of cell is formed exclusively—and with an admirable adaptation
of means to ends—for the purpose of aiding the proper function of the
first. kind of cell. This reciprocal purposive relation, with the results
of the due carrying out of the thus related processes, are amongst
the most wonderful phenomena of the whole domain of Biology.

One of the two reproductive elements here referred to is, as it were,
passive, and awaits the advent of the more active element. The former
is the female product; ‘the latter is the product of the male.

In order, then, to effect reproduction, distinct SEXUAL ORGANS are
required for the formation (secretion) of these two elements. But itis
also evident that other organs are needed whereby the juxtaposition
of these elements may be effected, and thus it is clear that the genera-
tive organs must be of two kinds: (1) internal organs, which concern
the formation of these elements themselves, and (2) external organs,
which ccncern their transmission and conjunction. These organs
may be expected to be different in the two sexes, as is in fact the ~
case, and thus we have to consider the external and internal gene-
rative organs, both of the male and of the female sex.

§ 20. The MALE GENERATIVE ORGANS of the cat consist, in the
first place, of two glandular structures, the testes (which are the
essential male organs, since it is they which secrete the male gene-
rative element).

Two tubes, one from each testis, called the vasa deferentia, open
into that. median canal, the urethra, which, as we have already seen,
proceeds from the anterior orifice of the bladder. This canal also
receives the products of certain accessory glandular structures, and
proceeds to traverse that median external body, the penis, which
latter serves as the channel of exit to the urinary secretion as well
as to the generative products. As it leaves the bladder, the urethra
is surrounded by one of the accessory structures before referred to,
namely, the prostate gland. The other accessory glands, called
Cowper’s glands, are two small rounded bodies, placed one on each
side of the urethra and in front of the prostate gland. Each vas
deferens enters the urethra beside its fellow of the opposite side.

The penis is a conical body, mainly composed of fibrous tissue,
but extremely vascular. Its tissue is of two kinds, arranged
in three masses: One mass, median, ventral, and terminal in posi-
tion, is called the corpus spongiosum, and immediately invests the
urethra. The other kind forms two laterally and dorsally situated
masses, called the corpora, cavernosa, which are placed side by side,
and form the bulk of the organ, which is attached by its root to the
pubes and the part of the ischia nearest the symphysis pubis. The
distal end of the organ is called the glans, and is an expansion of the
corpus spongiosum. It is conical and pointed, and has at its ex-

R

242

THE CAT. | (CHAP. VIII

tremity the external orifice of the urethra. The organ is held
suspended from the wall of the abdomen by a fold of integument
which is inserted around the glans, formimg what is called the

Fig. 115.—MALE ORGAN
OK GENERATION—INFERIOR
SURFACE.

u. Ureter.

vd. Vas deferens.

p. Prostate.

cg. Cowp2:’s gland.

e. Krector penis muscle.

+g. Glans penis.

b. Bladder.

1, One of the crura of
the penis, with the
ischio - cavernosus
muscle upon it.

2. Accelerator uring mus-
cle which invests the
proximal, ventral
part of the penis.

A portion of the external
skin has been left at-
tached round the base
of the glans.

prepuce (Fig. 115). When not sexually active,
the penis is bent backwards towards its ex-
tremity, a condition which makes the cat
“retromingent.” A small bone traverses the
midst of the distal part of the penis, reaching
almost to its extremity. The surface of the
glans is beset with hard papille, the points of
which are directed towards its base.

The corpora cavernosa and the corpus
spongiosum are each formed of a spongy mass
of fibrous bands, called trabecule, contaming
elastic and muscular fibres as well as nerves
and arteries. In the intervals of these bands
are highly distensible veins, into which a
certain number of arteries directly open. It
is the capacity for temporary distension by
means of such veins which causes these tissues
to be spoken of as “ erectile.”

The urethra consists of a tube of mucous
membrane invested by organic muscular fibres.
It originates at the bladder, upon quitting which
it enters a gland to be shortly described as the
prostate. In the floor of this prostatic portion
of the tube is a small, ridge-like prominence,
called the verum montanum, in the midst of
which is a narrow, slit-like depression, named
the utricle (sinus pociularis, or vesica prostatica),
at or within the margins of the opening of

which the seminal ducts, or vasa differentia,

open into the urethra.

The term “membranous urethra” is applied
to that portion of the tube which emerges from
the prostate gland. Its membranous part is
soon succeeded by its ‘ spongy portion,” 7.é.,
by the part which traverses the penis. Distally,
the urethra is lined by squamous epithelium,
but elsewhere by epithelium of the columnar |
kind.

The urethra of the male thus transmits both
the renal excretion (which traverses its whole
length) and also the sexual secretion, which
traverses that part of it which is beyond the

entrance of the vasa differentia.
The prostate gland (Fig. 115, p.) is a voluminous, prominent,
andular structure surrounding the urethra at its exit from the
bladder, and opening into that canal by numerous apertures at the

i
ae aR a he) lag ’
ee ed : - j

sie v

_* ”” . 4

a
«ae ra

- cHAP. vul.] ORGANS OF RESPIRATION AND SECRETION. 243
side of the verum montanum. It is made up of a number of small
follicles, which open into its excretory canals, the apertures of which
have just been mentioned. It is invested by a fibrous coat con-
taining many organic muscular fibres. It secretes a fluid of a
milky appearance.

Cowper's glands (Fig.115, ¢ g) are two large racemose structures
of firm consistency, with a thick muscular envelope, placed one on
each side of the urethra and a little beyond the prostate. Each
opens by a single duct into the urethra at the root of the penis.
These glands secrete a viscid fluid of unknown function.

The scrotum is that pouch of integument which is destined to
contain the testes, which hang within it beneath the anus and
behind the pelvis. Although this pouch (the scrotum) is single
externally, an inner coat—the dartos—(consisting of vascular mem-
brane with organic muscular fibres) forms two pouches, one for each

4q testis. This coat is continuous with the fascia of the abdomen and

q thigh. Within it is a layer of membrane—the spermatic fascia—

and other envelopes of connective tissue or muscular fibres—one

delicate layer of the latter tissue forming what is known as the
cremaster rauscle.

Each testis is also enveloped in a pouch of peritoneum, called the
tunica vaginalis, within which is the tunica albuginea—a dense,
white, fibrous membrane, which immediately invests the testis itself.

§ 21. The Testes are the true male sexual glands, to which all the
other male sexual organs are but auxiliary. Each testis is an oval
body, which is suspended in the scrotal chamber by a cord—the
spermatic cord—which passes forwards and inwards through the
abdominal ring to the urethra. A conical, more or less separable
body, known as the epididymis, lies dorsally and posteriorly upon
the testis. As it is external to the testis itself, it is not invested by
the tunica albuginea. One rounded end of the epididymis—called
the globus major—is connected with the testis by certain ducts. The
other more pointed end—the globus minor—ais only united to it by
connective tissue.

At that portion of the testis which is adjacent to the epididymis,
the tunica albuginea is prolonged far down into the soft substance of

the gland, forming a septum called the mediastinum testis, or corpus

q Highmorianum, which is situated in the middle of the testis. Many

slender cords and lamelle of connective tissue radiate from the

mediastinum to the inner surface of the tunica albuginea, thus
dividing that portion of the gland by imperfect partitions into conical
interspaces, and helping to maintain the shape of the testis. The
gland is richly supphed with blood-vessels, which ramify in the
tunica albuginea and accompany its partitioning processes. Between
these membranous imperfect partitions, lies the soft proper glandular
substance of the testis, which consists of minute convoluted tubes,
called tubuli seminiferi, because they are the immediate agents in
seminal secretion. They are arranged in pyramidal aggregations or
“lobules,” respectively invested by the membranous imperfect par-

244 THE CAT.

titions before mentioned. They converge and anastomose (tubes of
adjoining lobules anastomosing also) as they approach the medias-
tinum and epididymis till they are greatly reduced in number, when
they assume a comparatively straight course, and are called the
tubuli recti, or vasa recta. ‘These traverse the mediastinum and
then form a network of tubes called the rete
vasculosum, from which network other tubes,
called vasa efferentia, arise, and these enter the
globus major of the epididymis.

The tubuli seminiferi are formed of connective
tissue lined with a basement membrane and
epithelium which is never ciliated but con-
sists of nucleated granular corpuscles and nu-
cleated cells, which transform themselves into
the male generative elements.

The structure of the epididymis is much
more simple than that of the testis. It con-
sists of an enormously long convoluted tube,
into the proximal part of which the vasa
efferentia open.

Fig. 116. — Dracram

(CHAP, VIII.

SHOWING THE ARRANGE-
MENT OF THE TUBES IN A
MAMMALIAN TESTIS.

aad. Tubuli seminiferi,
coiled up in the se-
parate lobules.

b. Vasa recta.

c. Rete vasculosum.

d. Vasaefferentia,ending
in the coni vascu-
losi.

1, e, g. Convoluted canal
of the epididymis.

h. Vas deferens.

f. Section of the back
part of the tunica
albuginea.

i,%. Fibrous processes
running between the
lobes.

ftos. Mediastinum. In
the cat the mediastinum
is not on one side, as
in the above figure, but
is nearly in the middle
of the testis.

is given off from the commencement of the vas deferens.

These vasa efferentia, however, which are
nearly straight at first, do not remain so, but
each becomes much convoluted as it approaches
the canal of the epididymis, so that they form
a series of small conical masses called cont
vasculosi, the apices of which are turned

towards the testis and towards the apices of.

the conical lobuli of that gland. They all
successively open into the canal of the epidi-
dymis. This canal has its convolutions sup-
ported by connective tissue (thus forming lobes).
It increases in size towards the end of the globus
minor, where it acquires thicker coats and
becomes the vas deferens. The vasa efferentia
are lined with ciliated epithelium, as is also
the case with the canal of the epididymis.
Sometimes a small tube, called a vas aberrans,
A very

small pedunculated structure in the vicinity of the head of the
epididymis is called the hydatid of Morgagni. A few convoluted
tubules (also near the head of the epididymis) are sometimes spoken
of as the Organ of Giraldes or paremdidymis. These parts are quite
functionless remnants of a fcetal structure which will be noticed
in the chapter on Development.

The vas deferens—the continuation of the canal of the epididymis
—is at first much convoluted, but becoming straight extends up the
inner side of the epididymis, and thence upwards beside the spermatic
artery which goes to the testis, and the spermatic veins which leave
it, —these vessels, with the vas deferens and the tissues which unite

CHAP. vill.| ORGANS OF RESPIRATION AND SECRETION. = 245

them all together, forming the spermatic cord before referred to. The »
vas deferens is made of connective tissue enclosing a muscular coat,
the inside of which is mucous membrane, lined internally with
columnar but not ciliated epithelium. The two vasa deferentia
open into the urethra, as before described.

§ 22. The special secretion of the testis consists of certain sper-
matic filaments or SPERMATOZOA, which by their activity remind us of
detached cells of ciliated epithelium. They are not however the
equivalents of such cells, but of subdivisions of such cells. Each
spermatozoon consists of an oval flattened part called the ‘“‘ head”
or “body,” and of a long and very slender filamentary “ tail.”

Each spermatozoon is a peculiarly shaped cell of protoplasm, con-
taining a nucleus. ‘The oval portion or head con-
sists of the nucleus enveloped in an extremely
delicate layer of protoplasm, which protoplasm
is continued on to form the filamentary tail.

The spermatozoa are not the immediate product J
of the testicular tubuli; these first produce ‘‘ sperm-
cells” or ‘“spermospores,’ which constitute the
epithelium lining the tubuli. From these cells pe yr. — seerma
the spermatczoa appear to be formed by sub- = 70204 oF TR Caz,

Sin: MAGNIFIED 320 DIA-
division of the nucleus of each spermospore; the — merers, axp THEN

.

ENLARGED THREE ©

divisions of the nucleus forming the main part = ae

of the head of each spermatozoon, which is

completed from the non-nuclear substance of the dividing spermo-
spore.

The vibratile, lashing action of the spermatozoon, only takes
place when it is fully developed. It will retain its power of move-
ment for some hours after its removal from the body if immersed in
a suitable fluid. By its lashings it effects a locomotive movement,
and it is thus admirably enabled to advance towards its proper
destination. Without the aid of these spermatic filaments no
reproduction of the cat species can take place.

§ 23. The FEMALE GENERATIVE oRGANS may, like those of the
male, be divided into (1) the ezternal, and (2) the internal organs—
the latter being the essential sexual parts. The functions of the
female organs are, however, more complex than those of the male.
The latter are destined to simply form and discharge their products,
but the female organs have not only to do this but also to receive
the male product and to protect and further that developmental
action which is initiated by the junction of that male product with
their own. The female organs cousist, in the first place, of two
glandular structures, the ovaries, which secrete the female generative
product, the ova.. Two tubes, one for each ovary, called the
Fallopian tubes, open into a median tubular structure, the uterus,
which is continued onwards to the exterior by the help of another
tube—the vagina, immediately external to which is the wro-genital
chamber or vestibule, which is the most external portion of the
whole apparatus, and which opens on the surface of the body a

246 THE CAT. [CHAP. VIII.

little in front of the anal aperture. At the anterior part of the
vestibule is the opening of the urethra, which is contimued to this
point from the bladder. Just in front of the external opening of
the urethra is a small body called the clitoris, whence two folds—
the Jabia—proceed backwards (surrounding the external vaginal
aperture), beneath which (one on each side) are two glands, called.
those of Bertholin, the ducts of which open into the vestibule.

The urethra of the female is thus but a very short tube. It
transmits the renal excretion only, the sexual excretion not passing
through it. The vestibule represents the prostatic part of the male
urethra, but there 1s no part answering to the spongy portion of the
latter. There is no such part, because the clitoris {which is the
rudimentary representation in the female, of the penis of the male,
and is similarly formed of two corpora cavernosa, a corpus
spongiosum and a very small ossicle) is imperforate and not
traversed by the urethra.

There is no representative, in the female, of the prostate gland
of the male, but the ‘“Cowper’s glands” are represented by the
“olands of Bertholin,” which have a muscular envelope like their
analogues in the other sex.

There is no scrotum, because the ovaries (which are the analogues
of the testes) are enclosed within the abdominal cavity. Neverthe-
less the scrotum is represented by the labia which bound the external
aperture on each side.

We now come to parts in the female which are hardly represented
in the male. We saw in the latter that there was a slight depres-
sion (the “utricle”’ or ‘sinus pocularis,”) im the floor of the
prostatic portion of the urethra and between the entrance into it of
the vasa differentia. In the female, this small depression is repre-
sented by a deep cylindrical cavity consisting of two successive
parts, the vagina and the uterus, but no tubes open beside it corre-
sponding to the vasa differentia of the male cat. The vagina (which
opens posteriorly into the vestibule, while anteriorly it opens into
the uterus,) is formed of fibrous tissue and organic muscular fibre
lined with mucous membrane, with numerous papille and follicles,
and coated with squamous epithelium. Towards the vestibule its
muscular fibres arrange themselves as a sphincter. A few ridges
(ruge) extend along the length of its inner surface and terminate
abruptly at a transverse circular prominence (which may be a
distinct fold or may be almost indistinguishable) called the hymen,
which marks off the commencement of the vagina from the more
externally situated vestibule.

The uterus (Fig. 105, ut and ce) is a short muscular bag with
two very long, posteriorly diverging, branches or lateral contimua-
tions—the cornua—which extend horizontally forwards in the
abdominal cavity. ie.

Its commencement, the os tincw, projects prominently into the
hinder part of the vagina, and is beset with numerous short

Te _

CHAP. vill.] ORGANS OF RESPIRATION AND SECRETION. 247

apille. Anteriorly the cornua terminate by receiving the openings
of the Fallopian tubes.

The organ is formed of a mass of organic muscular fibre and
fiprous tissue (richly supplied with vessels and nerves) and is lined
with mucous membrane beset with simple tubular glands, which upon
its interior surface is coated with columnar and ciliated epithelium.

The uterus is the organ destined to shelter and nourish the ova
from shortly after their impregnation till the litter is brought forth.
This period is that of “ pregnancy,” and during it the organ in-
creases enormously in size and capacity and in the quantity of
muscular tissue it contains.

The size of the uterus therefore varies extremely, according to
whether it does or does not contain ova in process of develop-
ment, and according to the development which such ova may have
attained. The time of carrying the kittens within it, ze., the
period of gestation, having come to an end, the uterus begins to
undergo powerful contractions till its contents are expelled in the
act of giving birth, or parturition. This act accomplished, the
organ begins again to diminish, many of its muscular fibres undergo
a transformation into fatty matter and are then absorbed, and it
soon returns nearly to the size which it had before impregnation.

The uterus is held in place, partly by its continuity with the
Fallopian tubes and vagina, partly by igaments called respectively
“broad,” “ovarian” and “round.” The broad ligaments are great
lateral folds of peritoneum which embrace the uterus with its
cornua and the Fallopian tubes and ovary. The ovarian ligaments
are short fibrous cords which extend one from the end of each uterine
cornu to the adjacent ovary. The round ligaments are two delicate
fibrous cords which pass one from each of the sides of the uterus
to the brim of the pelvis.

The Fallopian tubes (Fig. 105, f) have been already mentioned
as extending along within the folds of the broad ligament to the
extremity of the cornua of the uterus—one Fallopian tube opening
into each cornu after following a much convoluted course.

At its opposite extremity each Fallopian tube ends in an ex-
panded, trumpet-like termination surrounded by certain irregular
processes or fimbrie, one of which, longer than the others, is
attached to the adjacent ovary. The fimbriated and expanded
end of the Fallopian tube has been named the morsus diaboli.
The cavity within the Fallopian tube is extremely minute, and
opens externally in the midst of its fimbriated extremity.

Each Fallopian tube is, as has been said, coated externally
with peritoneum; within this is a layer of longitudinal organic
fibres, and within this again’a circular layer. Within all else is
the mucous lining (which forms longitudinal internal folds,)
coated with columnar and ciliated epithelium. At the orifice of
the Fallopian tube the mucous membrane which lines its interior
becomes actually continuous with the peritoneal coat which invests
it externally. Thus, in the female (unlike the male) the perito-

\
\

248 THE CAT. [CHAP. WIII.

neum is not a shut sac but has two distinct perforations, the
mouths of the Fallopian tubes, which indirectly place its cavity
in connection with the external surface of the body.

§ 24. The ovary is the essential secreting organ of the female
sex, corresponding to the testis of the male. There are two such
bodies, one on each side, as there are two testes, but, unlike the
latter, the ovaries are each a completely closed sac or follicle, and,
though each has its excretory duct—the Fallopian tube—this duet
has no permanent connexion with its gland (as the vas deferens has

Fig. 118.—SErcTION oF THE PREPARED OVARY OF THE CAT—MAGNIFIED SIX DIAMETERS.

1. Outer covering and free border of the ovary. which have passed somewhat deeper into
1’. Attached horder. the ovary, and are surrounded by firm
2. The ovarian stroma, presenting a fibrous and fibrous stroma.
vascular structure. 8. More aivanced Graafian follicle, with the
3. External fibro-nuclear substance. ovum imbedded in the cells of the pro-
4. Blood-vessels. ligerous disc.
5. Ovigerms in their earliest stages, lying near | 9. The most advanced follicle, containing the
the surface. ovuin, and approaching the surface.
6. Ovigerms which have begun to enlarge, and | 9’. A follicle from wh.ch the ovum has acci-
to pass more deeply into the ovary. dentally escaped.
7. Ovigerms, round which the Graafian follicle | 10. Corpus luteum, presenting radiated columns
and tunica granulosa are now formed, and of cellular structure.

with its testis), but only a temporary one. The ovary is of an
oval shape (like the testis). It lies deeply in the dorsal and lateral
part of the abdominal cavity, hidden by the intestines, and en-
veloped in a fold of peritoneum which forms its outer coat. The
inner end of the gland is attached to the uterus by a dense cord,
already mentioned as the ligament of the ovary. At the anterior
border of the gland is a depression called the /iJus, where the blood-
vessels enter, and which is the only part not invested by the
peritoneum. Beneath the outer or serous coat of the ovary is its
second or proper covering, the tunica albuginea, often compared with
the same part of the testis. It serves to maintain the organ in
shape, but really is but a condensed part of what is. beneath it,
namely, the proper tissue—the stroma, or parenchyma, of the ovary.
This substance is of a pink, or red, colour (from the number of
vessels it contains), and is made up of connective tissue, with nerves,

CHAP. vul.] ORGANS OF RESPIRATION AND SECRETION. 249

blood-vessels, and some muscular fibres. It has an outer epithelial
covering, and contains embedded vesicles of various sizes—called
Graafian follicles—containing the ova, or true female sexual
product. ;

In the stroma of the ovary there is but little fibrous connective
tissue. It is made up mainly of large spindle-shaped cells,* which
surround the Graafian follicles, being arranged concentrically about
them. |

Upon dividing the ovary, vesicles of various sizes are seen within,

x > ‘ cS RN
SN = SSsss_\
WAN

Fig. 119.—PorRTION OF THE SECTION OF THE PREPARED CAT’S OVARY, REPRESENTED IN THE
PRECEDING FIGURE, MORE HIGHLY MAGNIFIED.

1. Outer covering of the ovary. follicle, within which is situated the ovum

2. Fibrous stroma. covere | by the cells of the discus proligerus.

3. Superficial layer of fibro-nuclear substance. 8. A follicle further advanced.

3’. Deeper parts of the same. 8’. Another which is irregularly compressed.

4. Blood-vessels 9. The greater part of the largest follicle—in

5. Ovigerms forming a layer near the surface. which the following parts are seen: 4a,

6. One or two of the ovigerms sinking deeper, cells of the membrana granulosa lining the
and beginning to enlarge. follicl:; 06, the reflected portion, named

7. One of the ovigerms further developed, now discus proligerus ; c, vitellus or yelk part of
enclosed by a prolongation of the fibrous the ovum, s:u rounded by the zona pellucida,

stroma, and consisting of a small Graafian d, germinal vesicle ; e, germinal spot.
and these are much more numerous jn the very young animal than
in the adult. :

These vesicles, or “ Graafian follicles,” are naturally spherical or
oval, and have three coats. The first and most external of these,
the tunic of the ovisac, or tunica fibrosa, is a fibrous, vascular
membrane, containing oval nuclei, but destitute of oil globules.
The second coat is the ovisac, formed of connective tissue, rounded
cells, and minute oil globules. The third coat (if it should be
really recognized as distinct) is the membrana granulosa, consisting

b

* See Klein and Noble Smith’s Atlas of Histology.

250 THE CAT. [CHAP. VIII

of a stratum of nucleated cells lying im close contact with the inner
surface of the ovisac. Enclosed within these layers is a clear and
colourless albuminous fluid, and a small, rounded body, embedded
in a cellular mass, the discus proligerus or cumulus, on the mner
surface of the membrana granulosa. This rounded body is the
ovum—the special female sexual element. The larger Graafian
vesicles are found at, or near, the surface of the ovary, and it has
been found that they approach the surface as they develop. They
are indeed primitively formed at the periphery, but they subse-’
quently sink inwards, and afterwards return once more to the
surface. At first the Graafian vesicle is but the envelope of the
minute ovum it contains. It subsequently increases, so as to exceed
in size the contained ovum to a greater and greater, and ultimately
to a very great, degree.

§ 25. The ovum is a minute spheroidal mass of protein substance,
about the =4, to zs of an inch in diameter. It consists of an
external tough, elastic, and relatively thick tunic, the zona pellucida,
which is quite transparent and _ struc-
tureless, though apparently perforated by
many excessively minute pores. Enxter-
nally the zona pellucida is invested by a
layer of epithelial cells, the ¢wnica granulosa,
which is embedded in the cellular mass,
the cumulus, which connects the ovum
Fig, 120.—Tue Ovum, crearry With the imnermost coat (or membrana

ASNT: granulosa) of the Graafian vesicle. Within
ee te, Chehehe ges the zona pellucida is the yelk imacsmes

cida, which shows a radiated

linear structure, Within this go9me say enclosed within a distinct, but
is the yelk substance, with

granules and small oil glo- extremely delicate,membrane) of protoplasm

lage ‘germinal veel wee ~=6and «granular matter, with oil globules,

ae eo rrinal spot. but having within it a nucleus termed the

! germinal vesicle, about the =, of an inch

in diameter, and enclosing a minute opaque body or nucleolus, known

as the germinal spot, which is from the 55), to the 535, of an
inch in diameter.

Beside the ovary, within the folds of broad ligament, are certain
small tubules, which together constitute what is called the par-
ovarium. This small body is analogous to the organ of Giraldés,
found in some male animals. Connected with the parovarium is
a delicate, cylindrical structure called Gaertner’s duct, which runs
from the parovarium down the side of the body of the uterus, when
it ends blindly.*

A small pedunculated body in the vicinity of the parovarium, or
of the mouth of the Fallopian tube, is called a hydatid in the
female, as are corresponding structures in the male.

The function of the ovary is of course mainly to secrete ova, but
the formation of the Graafian vesicles, in which the ova are

* Mr. Alban Doran has ascertained these noints by careful dissections.

CHAP. vill.] ORGANS OF RESPIRATION AND SECRETION. 251

contained, must also be reckoned as a part of its function. The
development of ripe ova—or ovu/ation—begins to take place in the
first year of the animal’s life, and is thenceforth continued till the
bodily decay of age sets in.

It takes place at frequent intervals,* and culminates in the
rupture of one or more Graafian vesicles, with the discharge of the
ovum or ova from the surface of the ovary through its peritoneal
coat into the peritoneal cavity. This process is generally accompanied
with more or less constitutional disturbance, and an increased
supply of blood to the generative organs. By a wonderful and
quite unexplained process of reflex action, the rupture of a Graafian
vesicle is accompanied by a spontaneous application of the fimbriated
end of the Fallopian tube to the place of rupture. In this way the
discharged ovum, instead of being cast loose into the peritoneal
cavity, 1s received into the mouth and canal of the Fallopian tube,
and so conveyed onwards, by its ciliated lining, to the cavity of the
vterus. The walls of the ruptured Graafian vesicle then increase in
substance, and thus give rise, for a time, to a yellowish mass termed
the corpus luteum (Fig. 118, }°).

Simultaneously with the constitutional disturbance just referred
to, the sexual appetite is inflamed, and the animal becomes “at.
heat.”

The formation of the ova, unlike that of the spermatozoa, does not

take place in distinct tubes,t but in the seemingly non-tubular

substance or stroma of the ovary. The process of the formation of
the ova is so different from that of spermatozoa, and is so closely
connected with embryonic conditions, that its description is more in
place under the head of development. Nevertheless it may be here
observed that each ovum is a modified and enlarged cell of the
epithelial tissue of the ovary, which is thus, as before pointed out,
not the equivalent of a spermatozoon, but of a ‘‘sperm-cell” or
“‘ spermospore,”’ which is the parent of various spermatozoa. The
incipient ovum—or ovigerm—becomes surrounded by other smaller
cells, which subsequently, by multiplication and separation form
both the ‘tunica granulosa” of the ovum and the ‘membrana
granulosa”? lining the Graafian follicles—fluid gradually forming
and greatly increasing between these at first closely juxtaposed
layers. The outer envelope of the Graafian follicle appears to be
formed by other epithelial cells, and by a special growth of the
ovarian stroma around the developing ovum.

* It is difficult to ascertain how often, | settled ; but the wide divergence of form
as the adult unimpregnated female cat | which exists between the mature sexual
often seems to be almost continually | glands of the two sexes is manifest and
ready for reproductive activity. indisputable. For some recent observa-

+ Whether the composition of the | tions made with reference to this obscure
ovary and the formation of ova are | question, see a paper by Mr. E. A.
essentially ‘‘tubular,” is a question | Schafer, F.R.S., in Pro. Roy. Society,
which cannot yet be regarded as finally | 1880, p. 245.

CHAPTER IX.

THE CAT’S NERVOUS SYSTEM AND ORGANS OF SENSE.

§ 1. We have now to consider that system of parts which ministers
not merely to the processes of organic life, but also to motion, sensa-
tion, and cognition. It may therefore be considered as the highest
system of parts of which the cat’s body is made up. It is so closely
connected with motion, and motion is so closely connected with
sensation, that these functions would have been here treated of to-
gether but for three reasons: The first reason was that the consider-
tion of the muscles, as forming so large a part of the body, could not
conveniently be postponed; secondly, the intimate relation of the
muscles to the bony levers they move, made it desirable to consider
them immediately after the description of the skeleton ; and thirdly,
the study of the nervous system can hardly be profitably pursued till
acquaintance has been made with all the main organs and parts to
which the various nerves are distributed. Such an acquaintance
has now been made, and the nervous system remains alone for our
ultimate consideration, both as to its structure and as to its functions
—the most conspicuous of the latter being sensation. All forms of
merely physical activity, such as light, heat, chemical change, &ce.,
are indeed separated by a gulf from the activities of organic growth
and reproduction, but a gulf hardly less marked divides these latter
faculties from one so altogether peculiar and swi generis as is the
wonderful power of feeling and cognition.

But although the nervous system is that which MINISTERS TO
SENSATION—that without which we have no evidence that sensation
is even possible—nevertheless such a definition of its functions would
be very incomplete. The nervous system is the immediate cause of
motion, and performs, as we shall see, an intermediate part between
the organism containing it, as a whole, and the environing world,
since it receives influences from the latter which may excite cor-
relative activities in the organism without, as well as with, the
accompaniment of sensation. |

It has been before said that an organism is a body in which each
part is reciprocally end and means. In animal organisms, this re-
ciprocity is generally ministered to and effected by the agency of the

CHAP. Ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 253

nervous system, and this reciprocal activity is mainly effected with-
out “ feeling’’ coming into play.

Thus the nervous system may be DEFINED as the GREAT co-
ORDINATING sysTEM of the body; co-ordinating the action of the
parts of the body one with another, co-ordinating the action of such
parts with relation to surrounding influences and conditions, and
also co-ordinating the action of the body as a whole with relation
to such influences and conditions—the activity of the nervous system
being more or less frequently accompanied by acts of sensation.

§ 2. SensaTION 1s incapable of definition, since to be understood
it must be experienced, and every man must know what it is to have
a feeling who knows anything whatever, as “sensations” are with
us the indispensable antecedents of ideas, and therefore of all know-
ledge. Sensation, however, may be described as a special and alto-
gether peculiar vital organic activity, which accompanies certain
actions of the nervous system occurring under the requisite con-
ditions.

§ 3. That system of parts, the nervous system, the nature of
which has just been defined, is made up, lke the skeleton, of two
great divisions, one AXIAL, the other PERIPHERAL. Besides these, that
part of the peripheral system which especially supplies the viscera, is
commonly reckoned as distinct, under the name of the sYMPATHETIC
system. The whole consists of a peculiar tissue (to be shortly
described), forming a white or grey pulpy mass in the form of bulky
ageregations, and of cords or threads, which radiate in all directions
from such aggregations.

The avial part of the nervous system is that bulky aggregation

of nervous or neural matter, which occupies the cranial cavity and

the neural canal of the vertebral column (Fig. 2, 7), that is to say,
it is the brain and spinal cord which are together spoken of as the
cerebro-spinal axis.

The peripheral part of the nervous system is that system of cords
or threads of neural matter which are called nerves, and which
proceed out from the cerebro-spinal axis to all parts of the body.
Scattered amongst them every here and there are certain agegrega-
tions of nervous matter—in rounded or irregularly-shaped masses
of various sizes—called ganglia. That portion of the peripheral
part of the nervous system called the sympathetic (and which, as
just observed, is specially distributed to the viscera) differs somewhat
from the rest as to its minute structure.

§ 4. Nervous TISSUE 1s a soft, nitrogenous substance of very com-
plex chemical composition. It is reducible into water, albuminoid
matter, fatty and extractive matters, and sundry salts. Different parts
of it contain from 73 to 85 per cent. of water, 7 to 10 per cent. of
albuminoid matter, and from 5 to 15 per cent. of fat.

The fatty matters consist of cerebric, glycero-phosphoric, and
palmitic acids, with olein, margarin, palmitin, and cholesterin.
From brain-ash the following percentage of different substances
has been obtained. Phosphate of potash, 55°24; phosphate of soda,

ee ed

i i rr i i og el i

foe es eee ee ae ee eee

254 THE) CAD. [CHAP. Ix,
22°93; phosphate of iron, 1:23; phosphate of lime, 1-62 ; phosphate
of magnesia, 3:4; chloride of sodium, 4°74; sulphate of potash,
1°64; free phosphoric acid, 9:15; and silicic acid, 0°41.

The STRUCTURAL ELEMENTS of nervous tissue are mainly of two
kinds: (1) fibres, and (2) nerve-cells or corpuscles. The former ot
these elements makes up the bulk of the peripheral part of the
nervous system, while the corpuscles abound in its axial portion and
in its scattered ganglia.

The NERVE FIBRES are again divisible into two kinds: (1) the
white or tubular nerve fibres, and (2) the grey or pale fibres.

The white fibres, which form the buik of all the nerves except
those of the sympathetic system, are nearly cylindrical filaments

Fig. 121.—WuitE NERVE FIBRES.

A. White or medullated nerve-fibres, showing occasionally seen in the tubular fibres, viz.
their sinuous outline and double contours. 1—l. Membrane of the tube, seen at part
B. Diagram showing the parts of a medullated where the white substance has separated
fibre, viz. : from it.
1—1. Primitive sheuth. 2. A part where the white substance is
2—2. The white substance, or medullary interrupted.
sheath. 3. Axis projecting beyond the broken end
3. The axis-fibre, or axis-cylinder—some- of the tube.
times called the primitive band. 4. Parts of the contents of the tube which
C. Diagram intended to represent appearances have escaped.

which, during life, seem composed of a clear, oily, semi-fluid sub-
stance, but after death, appear as composed of a delicate structureless
outer membrane—the primitive sheath (like the sarcolemma of muscle
fibre), provided with large nuclei, and containing fatty fluid termed
the medullary sheath or white substance ef Schwann, through which
runs a thin central thread of albuminoid matter called the axis cylinder.

cap. 1x.} NERVOUS SYSTEM AND ORGANS OF SENSE. 255
at other parts of its course than at their origins or terminations. The
terminations of nerves, whether they end peripherally or centrally, are
often spoken of as “end organs.” White nerve-fibres run side by
side in a bundle, bound together by delicate connective tissue, which
also forms a sheath for them called the neurilemma. In spite of
their close proximity these fibres have never been observed to
anastomose, nor have single fibres been seen to branch till within a
microscopic distance of their termination. This ultimate branching
may be due to the axis cylinder really consisting of distinct fibrils
bound together, as a longitudinal striated appearance they sometimes
exhibit would seem to indicate. On the other hand, by the action
of nitrate of silver they may be made to exhibit a transverse striation
like that of muscular fibres, so that the meaning of either of these
appearances is problematical.*

The grey or pale fibres are chiefly found in the nerves of the
sympathetic system, but the olfactory nerves also are entirely com-
7 posed of them. They are from, to ss'cy of an inch in diameter,

| and are devoid of that apparent distinctness of parts characterising

Fig. 122.—NERVE-CELLS FROM THE OUTER GREY PORTION OF THE CEREBELLUM, MAGNIFIED
260 DIAMETERS.

aa. Cells, each containing a nucleus, with a
distinct nucleolus.
6 6. Simple unbranched processes.

ce’, dd’. Branches radiating in different direc-
tions, and ramifying in various degrees.

the white fibres. They appear translucent, homogeneous, and slightly
granular, and exhibit at intervals oblong nuclei, which have been
supposed to belong to the sheaths of such nerves.

Nerve cells, or nerve corpuscles, are very different in appearance
from nerve fibres. Each consists of a round, oval, pyramidal, club-
shaped, pear-shaped, or many-cornered microscopic body, formed of
protoplasm, and which may appear clear or granular according to cir-
cumstances (perhaps of 'observation), and which contains a nucleus
with one or more nucleoli. Some of these cells are devoid of processes

5 * There now appears to be reason to suppose that the axis cylinder is really
segmented.

256 THE CAT. ) - [omap. rx.

(and this, for the most part, is their form in ganglia), many have
but one, very many have two or more—conditions denoted by the
terms “apolar,” ‘‘ unipolar,” “ multipolar.” Sometimes a process
from one cell may be seen to join a process from another cell.
Sometimes a process from a cell appears to continue on as the axis
cylinder of a nerve. Nerve fibres certainly often appear to end close
to cells, but there 1s as yet much dispute as to the connexions between
them and between the processes of different cells. A desire to serve
a particular theory has certainly given rise to much exaggeration as
to the amount—often even as to the existence—of such connexions.
In most cases the processes seem simply to ramify and become finer
and finer till they cease to be distinguishable.

Neuroglia is a substance which immediately surrounds the fibres
and cells, and which has been supposed to be a peculiarly modified
form of connective tissue. It is a semi-solid matrix which appears
granular, though it may really be structureless—its granular
appearance being the result of a coagulation.

Such being the nature and minute constituents of the nervous
system, its great mass, the cerebro-spinal axis, is said to be made up
of white and of grey nervous matter. The former consists of white
fibres only, while the grey matter consists very largely of nervous
corpuscles, and is more vascular. Throughout the whole length of
the spinal part of the cerebro-spinal axis the grey matter lies towards
the middle of the whole nervous mass, the white matter being
external. In the cerebral part of the same axis, however, the grey
matter extends from within and expands over its surface. Although
the cerebro-spinal axis is very vascular, yet the arteries and veins
which traverse it are very minute.

5. The cerebro-spinal axis is invested and protected by three
MEMBRANES, enclosed one within the other.

The first of these is called the dura mater, and is composed of
thick, dense, inelastic fibrous membrane, free and smooth on its
inner surface, but closely connected externally, in the skull, with the
inner surface of the cranial bones, of which it forms the periosteum.

In the spinal column it does not constitute the pericsteum of the
neural canal, but is only connected with the inner surfaces of the
vertebrae by loose areolar tissue and fat, and by slips of fibrous
membrane. |

In the cranium the dura mater sends inwards two folds of membrane.

The first of these is longitudinal, and is called the fal cerebri,
and extends from the front of the skull to the occiput, depending
from the middle of the cranial vault.

The second fold is the tentoriwm, which extends forwards and
downwards from the posterior margins of the parietal bones. It is
also attached to the upper edge of the petrous portion of each
temporal bone. The tentorium, as we have seen in the third
chapter, becomes ossified in the adult cat.

The second of the three membranous envelopes is called the pia
mater, and is a very delicate, vascular membrane, which is closely

CHAP. Ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 257

applied to the surface of the cerebro-spinal axis and conveys its
minute arteries to it (Fig. 123, c), It is thicker and less vascular on
the spinal cord than on the brain.
At the roots of the nerves it
becomes continuous with the
neurilemma.

The third membrane is called
the arachnoid, and is a serous
membrane forming a closed sac
and containing a fluid.

The outer, or parietal, wall
of this sac consists of a layer
of flattened and nucleated, poly-
gonal, epithelial cells, intimate-
ly connected with the dura
mater (both cranial and spinal)
externa! to it.

The inner, or visceral, wall
of the sac is a distinct mem-
brane investing, but not inti-
mately, the pia mater, the 7)
foldings of which it does not Fig, 123.—Brain IN sITU, THE UPPER PART OF

follow—a space, the swb-arach- ee Ore

: On fhe right side all the membranes are re-
noid space, existing between moved. ‘he pia mater (with its vessels)
them and containing a watery Temiaim On the lett side.

c. Cerebruia invested by pia mater.

secretion. A series of attach- ce. Cerebellum.
z cr. Crucial sulcus.
ments, called the ligamentum — ¥ Frontal bone.
fs. Frontal sinus.
denticulatum, connects the spmal 4° sipasor lateral gyrus.

part of the arachnoid fo the Middle lateral g rus.
spinal dura mater—one existing, 2 Zygoma a
on each side, between each pair

of nerves issuing from the spinal nervous axis.

§ 6. The sPINAL corD, or MYELON, is the more or less cylindrical
mass of nervous matter. of varying dimensions, enclosed within the
neural canal of the spinal column, extending backwards from the
margin of the foramen magnum of the skull.

It remains of considerable size thence backwards till it reaches
the hinder part of the lumbar region and sacrum, where it contracts
to a slender filament, the filum terminale, which extends on into
the tail.

The general form of the spinal cord is cylindrical, but it is a little
flattened from above downwards. It becomes somewhat broadened
out in two places. The first of these, called the cervical enlarge-.
ment, extends from the third cervical to the first dorsal vertebra.
The second, termed the dumbar enlargement, is situated at the lass
dorsal vertebra, whence the myelon tapers till it ends in the “ filum
terminale.”’

The cord is traversed by a deep median fissure both below and
Ss

258 THE CAT. (OMAP. Ix.

dorsally, of which the first or “anterior* median fissure” is the
more distinct, and a process of the pia mater is prolonged into it,
which is not the case as regards the posterior median fissure.

Each lateral half of the spinal cord is also marked by two longi-

Fig. 124.—DIFrrERENT VIEWS OF A PORTION OF THE SPINAL CORD FROM THE CERVICAL
REGION, WITH THE Roors OF THE NERVES, ENLARGED (ALLEN THOMSON).

In A the ventral or anterior surface is shown, 4. Posterior lateral groove, into which the pos-
the anterior nerve-root of the right side terior roots are seen to sink.
being divided; in B, a view of the 1ight side 5. Anterior roots passing the ganglion.
is given ; in C, the anterior or upper surface 5’. In A the anterior root divided.
is shown ; in D, the nerve-roots and ganglion 6. The posterior roots, the fibres of which pass

are shown from helow. into the ganglion, 6’.
1. The anterior median fissure. 7. The united or compound nerve.
2. Posterior median fissure. 7’. The posterior primary branch, seen in A and
8. Anterior lateral depression, over which the D to be derived in part from the anterior

anterior nerve-roots are seen to spread. J and in part from the posterior root.

tudinal furrows, of which the posterior, or posterior lateral fissure, 18
far the more distinct. These furrows serve to define what are called
the “columns”? which make up the cord-—each lateral half of it
being divided into an anterior, a lateral, and a rosterior column.
Nervous fibres (the roots of the spinal nerves) pass out at the anterior
and posterior lateral furrows. |

As the nerves which so pass out traverse the intervertebral
foramina of the spinal column, and as the spinal cord stops (as has
been said) much short of the hinder termination of the vertebral
neural canal, it comes to pass that the nerves which pass out at the
sacral foramina have run back for a longer or shorter distance within

* The terms ‘‘anterior” and “‘pos- | man with his upright attitude, but
terior” refer to human anatomy, which | unfortunate as applied to a quadruped
originated these names-applicable to | like tke cat.

CHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 259

the neural canal till they come to the foramina appropriated to them
respectively. Thus a bundle of nerves passes backwards in the
hinder part of that canal, on each side of the filum terminale, and
the whole bundle of such fibres goes by the name of the cauda
equinda.

: The spinal cord is composed principally of white fibres, while the
grey matter within it is so aggregated as to present the appearance,
in transverse sections, of two crescentic masses with their con-
vexities adjacent and placed one in each lateral half of the cord
(Fig. 124, C).

Each grey crescent ends in what is called an anterior and
posterior horn, which approach respectively to the anterior and
posterior lateral furrows. The posterior horn is long, with a narrow
end. ‘The anterior horn is shorter and thicker, with a rounded end.

Fig. 125.—LATERAL VIEW OF THE BRAIN.

F. Frontal lobe. what upwards from the spot to which the
T. Temporal lobe. | letter S has been made’to point.

ol. Olfactory lobe. s. Superior external gyrus.

nu. Medulla oblongata. m. Middle ext-rnal gyrus.

cb. Cerebellum. 2. Inferior external gyrus.

v. Pons Varolii. o. Supra-orbital sulcus.

S. Sylvian fissure (the Sylvian fissure is the | ¢. Crucial sulcus.
sulcus which passes backwards and some- | hk. Hippocampal gyrus. To the right of hf is
| seen the cut end of the left optic nerve.

The two crescents are united together by a band of grey tissue
running across transversely at the bottom of the posterior median
fissure, and called the grey or posterior commissure. Another band
of white tissue also runs transversely across at the bottom of the
anterior fissure, and is called the white or anterior commissure.

A minute central canal runs backwards along the whole length
of the spinal cord and into the filum terminale. It traverses the
posterior or grey commissure, and is lined with a layer of cylindrical
cells of ciliated epithelium. It is called the canalis centralis.

§ 7. The BRAIN, or ENCEPHALON, 1s that enlarged part of the
nervous centres which is contained within the cranium and is enve-
loped by the three membranes already described. It is a mass of soft,
but more or less solid, matter which fills up the whole cranial cavity,
fitting into all those depressions which we have found to exist in
the floor and other parts of that cavity. It consists of two large but

very unequal parts, termed respectively the cerebrum and cerebellum,
2 s 2

260 THE CAT. ‘ (CHAP. IX,

and of smaller portions which connect these together and with the
spinal cord, of which the brain (as has been already observed) is, as
it were, the greatly enlarged, anterior termination. |

The largest portion of the brain by far is the cerebrum ; which is
made up of two great masses termed hemispheres, placed side by
side, and forming the anterior, upper, and lateral parts of the brain.
Each cerebral hemisphere is considered to principally consist of two
main parts or Jobes. The more anterior of these is called the
frontal lobe,‘and it includes nearly the anterior half of each hemi-
sphere. The other is the temporal lobe, which forms a lateral and
inferior prominence, which hes in the “internal temporal fossa ” of
the inside of the skull.* The posterior, mer, and upper portion of
each hemisphere may be regarded as a slightly and indistinetly
developed posterior lobe. The hemispheres are united with the
hinder part of the drain mainly as follows :—The spinal cord on
entering the skull becomes modified and takes the name of the
medulla oblongata, and this is the hindmost part of the base of the
brain. Continuing forwards the medulla divides into two large
branches, the crwra, which pass respectively one into each cerebral
hemisphere, and thus connect them with the spinal column. On
the dorsal surface of this continuation of the spinal cord into the
skull, is placed the cerebellum (or second largest portion of the brain),
while on its ventral surface is a prominent mass of transversely
disposed fibres—the pons Varolii—which, as it were, wraps round
the anterior end of the medulla on its under surface, and covers in,
ventrally, its divergence into the crura, which thus appear to issue
from above the anterior margin of the pons. The brain contains
within it certain cavities, which, with one exception, are the greatly
enlarged and complexly shaped continuation forwards of that
minute. canal (the ‘“ canalis centralis”’) which’we have seen to
traverse the spinal cord for its whole length. The different por-
tions of this curiously expanded cavity within the brain are termed
ventricles, and they are lined by a delicate epithelial membrane
termed the ependyma. This ventricular cavity extends forwards
beneath the cerebellum and above the pons Varolu, and as it is
mainly bounded below (in front of the pons Varolu) by the
crura and certain other structures between them, so it is bounded
above (between the cerebellum and the cerebrum) by a variously
formed layer of brain substance, which will be described further on,
and which constitutes a minor bond of union between the cerebrum
and the parts behind it. From the anterior and lower part of each
hemisphere there proceeds forwards a body which consists of a
cylindrical prolongation of brain substance, ending in a rounded
expansion. ‘These two bodies are called the olfactory lobes.t They
lie within the olfactory fossa of the cranium.

* See ante, p. 83. the true olfactory nerves come from
+ In human anatomy they are often | them,
called the olfactory nerves. But in fact

-cHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 261

On removing the upper part of the skull (with the ossified
tentorium and the unossified part of the dura mater) the surface of
the brain comes into view as an ovoid, convex mass, consisting of
two large anterior portions, with a few large contorted prominences
on their surface, and a smaller pos-
terior part marked with numerous
small transverse folds or furrows.
The two large anterior portions
‘are the cerebral hemispheres, the
median, posterior part is the cere-
bellum—the anterior part of the
upper surface of which is overlapped
by the hinder portions of the cere-
bral hemispheres. The anterior ends
of the two olfactory lobes are also
to be seen projecting in front of the
middle of the anterior end of the
cerebrum (Fig. 126, o/). The median
line which divides the cerebrum
into its two lateral halves, or hemi-
spheres, is called the great or
median longitudinal fissure. The
smooth, contorted prominences on
the surface of the cerebrum, are
called the convolutions or gyri, the
depressions which separate them
are termed .sudci, or fissures. These wig. 196,—Urrer Sunrace or Bram,

"rl and sulci are distinguished b SHOWING THE DEEP LONGITUDINAL FiIs-
eel), Bute itrwalll bo Nathan ois Goad exas ee
to defer their description tilla further —¢ Crucial sulcus.

° : s. S.perior external gyrus.

acquaintance has been made with — m. Middle external gyrus.

the brain as a whole, and with all 3, Vermiform process of cerebellum,

its main constituent portions. The %™ Olfactory lobe.

pia mater so closely invests the brain

that it passes down not only into the great longitudinal fissure, but also
- into all the sulci of the cerebrum and into the numerous folds on

the surface of the cerebellum. The dura mater passes into the

great longitudinal fissure (the membranous fold dipping into it being,

as before said, known as the falx), and between the cerebrum and

cerebellum (the structure known as the tentorium), but it does not

descend into the mimor depressions of the brain surface.

If the two cerebral hemispheres be pushed apart, a large trans-
verse white band of fibres, called the corpus callosum, will come into
view, which band connects the two hemispheres for rather more
than the middle third of their antero-posterior extent (Fig. 129, cc).

If the hinder ends of the cerebral hemispheres be forcibly divari-
cated, then the layer of brain substance, before spoken of as extending
forwards from the front of the cerebellum, will come into view.
Upon its surface, immediately in front of the cerebellum, two pairs

Re tt ane ee
: ‘ zy

sn THE CAT. | [cHaAr. ix,

of rounded prominences may be remarked. These are known as
the corpora quadrigemina, and the hinder pair, called the testes, are

rather larger than the anterior pair, which are called the nates

(Fig. 127, ns). The corpora quadrigemina are solid, and do not
contain any internal cavity. In front of the midst of the anterior

pair, is a solitary prominence named the pineal gland.
Just in front of and external to the corpora quadrigemina, there
is on each side a small prominence,

sometimes called the iernal corpus
geniculatum, because, in man, there is
a. second, contiguous, but more ex-
ternally placed prominence, named the
external corpus geniculatum—a structure
which in the cat is hardly to be dis-
tinguished.

The cerebellum is attached to the rest
of the brain by three pairs of procésses
or crura. The first of these are meluded

Fig. 127.— Ureer Surrace or 1 the fold of brain substance just de-
BRAIN’ OF Car = THe Crrepeal scribed. Hor this fold’ is ¢xecemmmams

HEMISPHERES BEING WIDELY DI-
VaRIcATED, To sHow THE parts THEY . thin at the middle of its hinder part

7 Na as —called the valve of Vieussens—so that
ns. Nates.

pr. Pineal gland. the two thicker portions which laterally
S. estes.

Sv. Superior vermis of cerebellum. border the thin part, are reckoned as
Cc. Corpus callosum. 5

5. Fifth ventricle, a pair of crura and spoken of as the
Cs. Corpus striatum. processus a cerebello ad_ testes, on
Cg. Corpus geniculatum. :

Th. The optic thalamus. account of the parts they connect. The

second pair of crura of the cerebellum
re the two lateral continuations up into it of the two sides of the
pons Varoli, and these are much the largest crura, and form the
principal connexions of the cerebellum with the rest of the brain.
The third pair of crura are the inferior peduncles of the cerebellum,
or restiform bodies, which are the continuations upwards and for-
wards of the posterior and part of the lateral columns of the spinal
cord. They diverge as they advance.

The cerebellum is darker than the cerebrum. Its greatest
diameter is transverse, and it consists of two lateral lobes and a
median portion, called the vermiform process. ‘The numerous more
or less parallel grooves on its surface indicate so many folds of grey
substance enclosing white matter within. The central mass of the
cerebellum is composed of white matter, and lamellar processes of
the same substance proceed in all directions from that central mass
into the darker enveloping layer. The cerebellum hes:in that fossa
of the cranial cavity which we have seen to be bounded in front by
the petrous parts of the temporal bones, and behind by the line of
attachment of the tentorium to the occipital and parietal bones.

The medulla oblongata lics upon the basi-occipital. Its anterior
inferior surface is marked by a median groove, on each side of

called the corpus geniculatum. It is

CHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 263

which is an antero-posteriorly extending portion of white substance
(going to the Pons), called the anterior pyramid. Outside each such
pyramid is a small, more or less hidden, oval structure, termed the
olivary body, and external to and behind each of these is the band
of nervous tissue already spoken of as the restiform body. The
middle part of the posterior surface of the medulla is occupied by the
posterior pyramids, which are placed one on each side of its posterior
median fissure, and which are continuous behind with the median
dorsal parts of the spinal cord, and in front seem to blend with the
restiform bodies.

In order to see the inferior, or ventral, surface of the brain, it
must be removed from the cranial cavity, the cerebro-spinal axis
being cut through at the foramen magnum, 7.e., at the hinder end of
the medulla oblongata. This being done, the cut surface of the
medulla will exhibit a doubly crescentic arrangement of internally
placed grey tissue, similar to that shown by the cut surface of the
spinal cord. If, however, sections of the medulla be made at points
further and further forwards, it will be seen that the grey matter
gradually becomes concentrated (as the medulla advances gee |
near the middle of its dorsal surface.

The ventral surface of the brain being in view, the two tice
parts of the cerebellum are visible, one on each side of the medulla—a
small process of each half—called the floculus—is connected by the
dura mater with that depression on the inner surface of the petrous
portion of the temporal bone, which was described as the cerebellar
fossa.* Contmuing on we find on each side of the anterior end of
the anterior pyramids a conspicuous band of transverse fibres, each
of which is called a corpus trapezoideum. Immediately in front of
these bands, is the transverse, convex eminence of the pons Varolii,
against the hinder margin of which the front ends of the anterior
pyramids abut. The corpora trapezoidea form a transverse band
which is interrupted by these pyramids, while the greater band of the
pons Varoliis uninterrupted by them. The pons lies upon the anterior
part of the basi-occipital bone, and is medianly grooved by an antero-
posterior shallow depression, along which runs the basilar artery.

Emerging from the front of the pons are two masses of white sub-
stances marked with longitudinal strize, and made up of longitudinal
fibres (the crura cerebri) which diverge as they advance, and are
crossed superficially by two anteriorly converging round cords, the
optic tracts (which unite to form the optic nerves), and thus a
lozenge-shaped space is enclosed. At tlieir opposite extremities the
optic tracts run upwards and backwards to the corpora geniculata
already noticed. In the hinder part of this space (called inter-
peduncular) is a small rounded mass, the corpus albicans, which shows
an indication of a median division into two lateral halves termed
corpora mammillaria. In front of this is a slight prominence termed
the tuber cinereum, from the middle of which projects a hollow

* See ante, p. 66.

264 THE CAT. (CHAP. IX,

conical process, the infundibulum. At the end of the infundibulum

is a small oval reddish mass called the pituitary body, which is
received into the pituitary fossa
(or sella turcica) of the sphenoid
bone.

Between the diverging crura
and the corpus albicans, is a
depressed surface of greyish
matter perforated by numerous
small vascular openings, whence
it is termed the Jocus perforatus
posterior.

The tuber cinereum is @
lamina of grey nervous matter
extending forwards from the
corpus albicans to the median
junction of the optic tracts, or
optic commissure.

The pituitary body is very
vascular, and in structure is
hike a ductless gland, consisting
as it does of connective tissue

A" NS with granular matter and nu- |
1 cleated cells.
big al OF THE BRAIN. Another grey space with
r. Temporal lobe vascular openings—called the;
ol. Olfactory lobe. ofny mf pany) een
Pe rcots locus perforatus anterior 1s
es, Cerebelium. | placed on each side just in

i itultary bo . .
po, Pons Varolii, front of each optic tract.

Bae necace. Anterior to and beside these
mm. Corpora mammillaria or corpus albicans. small median parts are those
Up. Locus perforatus anterior. :

ct. Corpus trapezoideum. voluminous masses the cerebral
pa. Anterior pyramid. : g

a pues of olfactory nerves. hemispheres, which thus form

. Optic nerve. p
III, IV, VI. 3rd, 4th, and 6th nerves (those of Aiea) lar ge part of NS the
py eyemuscles) under surface of the brain.

. rigeminai nerve. ° . ;
Vir. Facial nerve. The great longitudinal fissure
VIII. Auditory nerve. . 2 = 7
FGigeas photyiceal. is seen mm the middle line in
X. Pneumogastric. front, and another but small
XI. Spinal accessory. Aaa
XII. Hypo-glossal, (Figs 125) lateral fissure (called

the Sylvian fissure) separates
the anterior (or fronta’) lobe from the one behind (or temporal
lobe) of the same hemisphere. The temporal lobes form two
great prominences on each side of the brain’s under surface.
Each is bounded behind by the cerebellum, and is well marked
off in front by the Sylvian fissure.

In a groove on the under surface of each frontal lobe is a body,
shaped something like a life-preserver, with an oblong head and a
thick stalk. This is the olfactory lobe or bulb. It is made up
largely of grey matter, but also contains white fibres. The stalks

cHap. 1x.} NERVOUS SYSTEM AND ORGANS OF SENSE. 265

connecting the lobes with the under surface of the cerebrum are the
crura, or peduncles of the olfactory lobes.

Upon turning back the optic tracts—at their union in the optic
commissure—a delicate layer is seen to connect them with the
anterior end of the corpus callosum. This delicate layer is called
the Zamtna cinerea, or lamina terminalis. It is also continuous,
below the optic commissure, with the tuber cinereum, and it is con-
nected on each side with the /ocus perforatus anterior.

As has been said, the minute cavity of the spinal cord expands
within the brain into a series of chambers, filled with fluid, termed
“ventricles,”

The hindmost or fourth ventricle is placed betwecn the cerebellum
‘and the medulla oblongata. It is a flattened, somewhat rhomboidal
space, bounded on each side by the crura of the cerebellum. Its
floor is formed by the posterior (dorsal) surface of the medulla. Its
roof is formed by the cerebellum and by the very delicate layer of
nervous matter placed between the processus a cerebello ad
testes, and already spoken of as the valve of Vieussens. It 1s also
bounded by a still more delicate film of nervous substance which —
extends backwards irom the cerebellum between its posterior (or
inferior) crura, the restiform tracts.

This ventricle is prolonged onwards by a narrow passage into a
larger cavity, the third ventricle, from the anterior wall of which a
small aperture leads right and left into two /ateral ventricles (one on
each hemisphere,) each of which is still further continued on into
the olfactory lobe in front of it. The further relations of the
various parts will be best understood by studying a median,
vertical antero-posterior section of the brain.

If the brain be thus BisEecreD in the line of the longitudinal
fissure, we find as follows :-—

The inner surface of the cerebral hemisphere in view is convo-
luted, and the cerebrum_may be seen to extend forwards together
with and above the olfactory lobe.in front, and beyond the anterior
end of the cerebellum behind

Beneath the middle of the cerebrum we come to the cut surface
of the corpus callosum, the front part of which bends rather sharply
backwards and downwards, forming what is called the knee (genv).
Beneath the bent-back extremity of the corpus callosum is the cut
edge of the lamina cinerea (or terminalis). At the upper part of this
lamina we find the cut surface of a transversely-extending white
cord, called the anterior commissure, and immediately behind the
lamina we find another cord, part of what is called the forniz. This
latter structure extends, not transversely, but at first upwards and
forwards ; afterwards curving backwards it passes to the hinder part
of the corpus callosum. The fornix is the median part of what is
really and morphologically the back of the cerebral hemispheres,
each half of the fornix belonging to one of the hemispheres. The
layer joming the two diverging and posterior portions of the
fornix is called the Jyra, and together these parts form part of the

es as

266 THE CAT. Comrie, ae

outer wall or bag of the cerebrum enclosing the lateral ventricles.
Filling up the interval between the corpus callosum and fornix is a
double membrane called the septum ducidum, a space called the fifth
ventricle being included between its two layers.

Below the fornix we have evidently cut into a cavity extending
down into the infundibulum and bounded in front by the lamina
terminalis. This cavity is called the third ventricle. A small
aperture (the foramen of Monro) opens immediately behind the

Fig. 129.—Tur BRAIN, AS SEEN WHEN A VERTICAL LONGITUDINAL SECTION HAS BEEN
MADE THROUGH ITS MIDDLE.

oc. Anterior commissure.

av. Arbor vite of cerebellum.

c. Crucial sulcus.

cm. Corpus albicans.

cc. Corpus callosum.

cq. Corpora quadrigemina.

F. Frontal lobe of cerebrum.

J. Fornix.

fm. Foramen of Monro (between the fornix and
the corpus callosum is the fifth ventricle,
enclosed by the two vertical layers of the
septum lucidum, which pass from the fornix
to the corpus callosum).

h. Hippocampal gyrus.

mm. Medulla oblongata,

ol. Olfactory lobe.

pv. Pons Varolii.

p. Pineal gland.

ot. Pituitary body.

s. Superior external gyrus.

vy. Velum interpositum (between it and the fornix
is a space enclosed by the folding over of
the cerebruin upon the roof of the third
ventricle).

3. Third ventricle.

4. Anterior end of fourth ventricle.

IT. Optic nerve, which leads back to the fourth
ventricle beneath the cerebellum.

The large white spot above Fig. 3 is the middle,
or soft commissure, cut across. The white
spot beneath and in front of Fig. 3 is the
cut surface of the optic chiasma.

anterior part of the fornix, and a little behind this aperture is the
cut edge of a bundle of transverse fibres which form what is called -
the soft (or middle) commissure. The third ventricle is bounded
above by a delicate membrane, the velum interpositum, which
consists only of the ependyma, the pia mater, and the arachnoid. Its
margins are very vascular, and bear the name of the choroid plexuses.
The vascularity is continued on in that part of the ependyma which
passes through the foramen of Monro into the lateral ventricles,
but of course the pia mater and arachnoid do not pass through that
foramen, as they never get inside the ventricles at all, but are
reflected back on the under surface of the fornix. Thus the
‘choroid plexuses’ of the lateral ventricles are (like those of the
third) merely portions of the ependyma, which happen to be very
vascular, and are not really intrusions from without. ‘This velum
interpositum thickens behind and forms a small prominence which
projects backwards as the pineal gland—reminding us of the pituitary
body below. It is reddish and very vascular, and contains two or

CHAP. 1x.]| NERVOUS SYSTEM AND ORGANS OF SENSE. 267

more cavities filled with a viscid fluid and gritty matter formed
of earthy salts. The third ventricle is bounded inferiorly by the
corpus albicans and crura cerebri and by the infundibulum, into
which it extends.

The space between the upper surface of the velum and the under
surface of the closely applied lyra is morphologically the outside of
the brain, though, in fact, it 1s in the middle of the eomplex whole
of the adult structure.

The cavity just described, the third ventricle, continues on back-
wards as a very narrow passage (the ‘fer a tertio ad quartum ventri-
culum), bounded below by the crura cerebri and above by a layer
of nervous matter continuous with the pineal gland, and exhibiting
the cut surface of a small transverse cord (the posterior commissure),
and also two prominences in section—parts of the corpora quadrige-
mina. <A little further back, this passage expands into the fourth
ventricle bounded in the way as already described.

The cerebellum in section shows (as might be expected from what
has been said about its structure) radiating, tree-like ramifications
of nervous substance (grey and white) known as the arbor vite.

Other sections are necessary to make clear other matters. Thus,
the foramen of Monro is the entrance to a cavity which is placed in
the cerebral hemisphere of the same side, these two cavities con-
stituting the first and second (or two /ateral) ventricles.

The so-called foramen of Monro is, in fact, a Y-shaped passage.
It is single below, where it communicates with the third ventricle,
but divides above into two branches, one to each lateral ventricle.

Each lateral ventricle is said to have two cornua. The anterior
cornu passes into the frontal lobe and penetrates the olfactory lobe
also. The posterior or descending cornu passes. into the temporal
lobe. Certain sulci on the surface of the cerebrum extend so deeply
as to produce eminences on the inner surface of the lateral ventricles.
One such structure in the descending cornu has been termed the
hippocampus major, and is a very marked elongated and rounded
‘prominence.

Each central hemisphere is, in fact, a bag, with walls of very
unequal thickness. Thus, part of the inner wall running along the
descending cornu of the lateral ventricle is reduced to the ependyma
(with the pia mater and arachnoid), and readily tears (forming what

is called the fissure of Bickat), and this rupture having (in man)
been mistaken for a natural opening, each lateral ventricle has been
supposed to communicate with the exterior close to the crus cerebri.

The hindmost part of the roof of the fourth ventricle is formed of
the ependyma alone, the pia mater and arachnoid being reflected
over the postero-inferior surface of the cerebellum.

Careful inspection shows that the septum lucidum is really (as
already mentioned) double, enclosing a very narrow space—the fifth
ventricle—the lamine of the septum lucidum passing downwards
from the corpus callosum to the fornix. This fifth ventricle has no
connexion with the other ventricles, and it differs from them, not

Se

268 THE CAT. | [CHAP. IX.

only in its isolation, but in its nature. It is in no way a prolonga-
tion forwards of the spinal canalis centralis.

This fornix is made up of two white cords closely approximated
anteriorly and diverging widely behind. Each springs from the
corpus albicans, and the two cords (called pillars or crura) ascend
(side by side) behind the anterior commissure, and with a branch of
the foramen of Monro on the outer side of each. They then curve
backwards, diverging, but at the same time united by that delicate
membrane called the /yra. They become connected with the corpus
callosum, and then pass into each descending cornu of the lateral
ventricles.

Two rounded bodies (the optic thalami) are placed one on each
side of the first described cavity (the third ventricle), and are con-
nected by the soft (or middle) and posterior commissures. Two
other rounded bodies (the corpora striata) are placed one in each
cerebral hemisphere between the anterior and descending cornua.
They are connected by the anterior commissure, which (like the
posterior commissure) is formed of white, transverse fibres, while the
soft commissure is almost entirely composed of grey matter.

Each corpus striatum is an outgrowth from the middle of the base
of its hemisphere, and is the ‘morphological axis of the whole
~ hemisphere.

The optic thalami are thickenings in the outer wall of the third
ventricle.

The two cords which have been spoken of as the optic tracts,
arise, one on eaeh side, from the optic thalami and run forwards
obliquely across the under surface of the brain to join together
immediately in frort of the infundibulum.

We have seen that the two sides of the brain are connected by
the fibres of the corpus callosum and of the three smaller commis-
sures. There is not only this direct transverse connection. Oblique
extensions of fibres also connect the right hemisphere with the left
side of the spinal cord (and therefore with the left side of the body),
and the left hemisphere with the right half of the spinal cord (and
therefore with the right side of the body). The fibres which pass
forwards through the “anterior pyramids” decussate and then
extend through the crura cerebri to the cerebrum. The fibres of
the crura radiate within the cerebrum in a fan-like manner, the
corpus striatum and thalamus being respectively anterior and
posterior to such radiation.

The transverse relation which thus exists between the two sides
of the brain and the body (which it supplies with nerves) extends
also to the organs of sight, but not to that of smell.

We may now, in conclusion, review the conditions presented by
the cerebral convolutions, 7.¢., by the gyri and sulci of the cerebrum.
These are thus disposed as follows :—

On the upper surface of the brain three more or less parallel
promipences or gyri, extend antero-posteriorly on each side of the
median longitudinal fissure. The innermost of these, the superior

cHaAr. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 269

lateral gyrus (Figs. 125 and 126, s) runs straight from behind for-
wards till it comes to a transverse furrow, the crucial sulcus (c),
round which it bends, running inwards again, and finally turns
outwards and downwards round another sulcus called the supra-
orbital (0). The next gyrus is the middle lateral (m), which curves
outwards and downwards at each end. Finally comes the inferior
lateral gyrus (i), which is seen, in this view, to be somewhat divided
towards each end by the terminations of two ascending sulci.

When the brain is vertically bisected, we see, above, the superior
lateral gyrus traversed by a feebly indicated antero-posterior groove,
while a deep sulcus, the cadloso-marginal sulcus, divides it incom-
pletely from the hippocampal gyrus (Fig. 129, h), which immediately
adjoims the corpus callosum, behind which it dips down, and passing
round the crus cerebri of that side runs forwards the marked promi-
nence of the temporal lobe (Fig. 128, 4). The sulcus on the concave
side of the lower part of this gyrus forms (by projecting into the
descending cornu of the lateral hemisphere) the hippocampus major,
which circumstance gives its name to this gyrus. At the anterior
end we see the crucial sulcus (Fig. 129, c), with the internal surface -
of the superior lateral gyrus beneath it.

When the brain is seen in profile, we see at its anterior end the
sharp bend upwards and downwards of the superior lateral gyrus
around the supra-orbital sulcus (Fig. 125, 0) and then its ascent
behind the crucial sulcus (c); after which it runs back along the
summut of the hemisphere. Within this is the median lateral fold (m),
while the whole space embraced by it is occupied by the inferior
lateral gyrus traversed by two ascending sulci, the summits of which
sulci appear at the side of the upper view of the brain. Next to
be noted is the small but very important Sylvian fissure (s), which
forms as it were the axis round which all these convolutions are
disposed. Finally the anterior end of the hippocampal gyrus (/)
makes its appearance beneath and in front of the Sylvian fissure.

When the under surface of the brain is in view we see the lower
anterior ends of the three Jateral gyri, and the large expanded
termination of the hippocampal gyrus is the temporal lobe.

§ 8. Having now reviewed the nervous centres or cerebre-spinal
axis, We may proceed to consider the PERIPHERAL PART of the
nervous system, 7.¢., the nerves which are given off by the axial part
of that system.

The nerves which go forth from the cerebro-spinal axis to different
parts of the body are bilaterally symmetrical, there being (beyond
the olfactory nerves) a pair (one right and one left) of each.

The most anteriorly-situated nerves attain their destination after
passing through the foramina of the skull, on which account they
are denominated cranial nerves. |

Of these there are twelve, as follows :—

1. Olfactory.
2. Optic.
3. Qculo-motor.

— 1HB CAT. , (cite

4. Pathetic (or trochlear).
5. Tri-geminal.

6. Abducent ocular.

7. Facial.

8. Auditory.

9. Glosso-pharyngeal.

10. Pneumogastric.

11. Spinal accessory.

12. Hypo-glossal.

Some anatomists reckon but nine cranial nerves; for they count
the eighth as one with the seventh (calling the facial part its portio
aura, ‘and its auditor y part its portio mollis), and reckon the
glosso-pharyngeal, pneumogastric, and spinal accessory (all taken
together), as their eighth. According to this latter system, the
hypoglossal nerve becomes the ninth.

The cranial nerves generally are cae to have two kinds of roots
or origins, one deep, the other superficial ;. but these are but different
portions, or stages, of the same nervous cord. The superficial
origin of each nerve is the point where it is obviously attached to
the surface of the encephalon, while its deep (or rea/) origin in-
dicates the furthest point to which it has yet been traced backwards.
A nerve may be visibly attached to the encephalon by one or several
roots. Some of these nerves are what is called “sensory,” and others —
“motor,” according as they minister to sensation or to motion.

§ 9. The FIRstr, or OLFACTORY nerves, are the numerous delicate
fibres which pass from the under surface of the olfactory lobes,
through the holes in the cribriform plate, down to the membrane
investing the nasal septum and ethmo-turbinals. What are,
however, often spoken of as the “olfactory nerves ”’ are the olfactory
bulbs themselves, with the stalks, or peduncles, which connect them
with the under surface of the cerebrum.

They are composed of grey matter mixed with white fibres. the
grey matter being especially abundant in the bulb. Each so-called
nerve has at least two roots :—

1. The external root is a broad band of white fibres, extending
outwards and backwards along the outer margin of the anterior
perforated space to the Sylvian fissure (Fig. 128).

2. The inner root consists of a narrow band of white fibres, which
extends back along the inner side of the anterior perforated
space.

§ 10. The seconp, or optic, pair of nerves spring superficially
from the union of the optic tracts, in what is called -the chiasma or
optic commissure (Fig. 128).

Their deep origin may be traced back to the optic thalami, corpora
geniculata, and corpora quadrigemina. Fibres arising from these
parts converge on each side, and form the optic tract, which runs:
obliquely across the lower surface of the crus cerebri of the. same
side, behind the anterior perforated space to the chiasma. Posteriorly,
it is more flattened ; anteriorly, it 1s more cylindrical.

Arrived at the chiasma, the outer fibres of each tract continue
onwards to the optic nerve of the same side beyond the chiasma,
while the inner fibres cross over in the chiasma, and continue on in
the optic nerve of the opposite side. Some fibres appear to cross
from one optic tract to another, along the posterior part of the
chiasma, and others to cross, along its anterior part, from one optic
nerve to another. |

From the chiasma each optic nerve extends through the optic
foramen in front of it—diverging widely from its fellow of the
opposite side. Emerging from the optic foramen, it is surrounded
by the recti muscles of the eyeball, the hinder part of which it
enters a little to the inside of its middle, piercing the two outer

coats of the eyeball, and expanding within it (to form the Retina),

as will be hereafter noticed in describing the eye.
The optic nerve is made up of a number of separate bundles of
fibres, enclosed in prolongations of the dura mater. In the middle
of these bundles runs a small artery called the arteria centralis retine.
§ 11. The ruiep pair of nerves (oculo-mofor) arise deeply from a

grey nucleus in the floor of the iter a tertio ad quartum ventri- |

culum, close to the origin of the fourth nerve. They issue from the
cerebral surface in the interpeduncular space between the
erura and cerebri, and immediately in front of the pons Varolii
(ie) 128,717).

Each nerve traverses the dura mater and sphenoidal fissure, and, -

after receiving one or two fine branches from the sympathetic,
divides, and goes to supply the superior, inferior, and internal recti
muscles of the eyeball, as also its inferior oblique muscle, and that
of the elevator of the eyelid.

The FourTH pair of nerves, called also the TRocHLEAR or (from
their function of raising the eyeball) PparHeric, arise deeply from
one grey nucleus in the floor of the iter a tertio ad quartum ventri-
culum, and from another in the floor of the fourth ventricle —close to
the origin of the fitth nerve. They issue from the cerebral surface, one
on the outer side of each of the crura cerebri (Fig. 128, JV), im-
mediately in front of the pons, but each may be traced back round
the crus to a spot below and behind the corpora quadrigemina in
the valve of Vieussens. It goes through the sphenoidal fissure to
the upper oblique muscle of the orbit.

§ 12. The FirrH pair of nerves, called also the TRIGEMINAL,
arise by two roots, one large sensory root, and one small root called
motor, because its branches minister not to sensation, but to
muscular contraction.

The large root takes its deep origin from behind the olivary body,
if not from the floor of the fourth ventricle, and emerges from the
surface of the encephalon at the side of the pons Varoli, near its
upper and anterior margin, just where its fibres extend upwards
and backwards to form the middle crus of the cerebellum.

The small- root also takes its deep origin from the medulla
oblongata, and possibly from the floor of the fourth ventricle. It

CHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 271

_ |,

BYP) i Boag | CHAP. Ix,

comes to the surface of the encephalon just above the superficial
origin of the larger root, which at first conceals it. a
At a short distance from its origin the larger root swells out mto

SLE
=<

Fig. 130.—D1AGRAM REPRESENTING THE PRINCIPAL CRANIAL NERVES.

The orbit is cut open, the zygoma and part
of the cranial wall removed, and the man-
dible reflected downwards to show its inner
surface.

MN. Third or nictitating eyelid.

Sr. Superior rectus muscle.

Er. External rectus.

Ir. Inferior rectus.

Lp. Levator palpebree muscle, cut and pulled
upwards. .

gn. Gustatory nerve, going to tongue.

Ct. Chorda-tympani.

in.d. Inferior dental.

mh. Mylo-hyoid.

Oc. Occipital condyle.

i. Infra-orbital.

d. Dental nerve.

gg. Gasserian ganglion.

gpv. Ganglion of trunk of pneumogastric.

sl and il. Superior and inferior laryngeal nerves.
2. Optic nerve.

3. Third nerve, or ocwlo-motor.

5. Trigeminal.

5a. Ophthalmic, or first division of fifth nerve.
50. Its second division.

5c. Its third division.

6. Sixth nerve, or wbducens.

7. Facial.

9. Glosso-pharyngeal.

10. Pneumogastric.

11. Spinal accessory.

12. Hypo-glossal.

what is called the Grasserian ganglion (Fig. 180, gg). It is jomed
by some sympathetic nervous filaments, and then gives off three
large branches, the hindmost of which is joined by the fifth nerve’s
lesser root. |

The first of these three branches, which is the smallest, and
one notably distinct from the others, is called the oPHTHALMIC
NERVE (Fig. 130, 5a), which passes through the sphenoidal fissure,
and supplies, by its subdivisions, the eyeball, mucous membrane of
the eyelids, lachrymal gland, and the skin of the nose, forehead,
and upper eyelid, dividing into its nasal, frontal, and lachrymal
branches. :

CHAP. Ix.| NHRVOUS SYSTEM AND ORGANS OF SENSE. 273

The second of the three branches of the fifth nerve is called the
SUPERIOR MAXILLARY -NERVE. It passes through the foramen
rotundum, and supplies the lower eyelid, the side of the nose, the
upper teeth, and the upper part of the mouth and pharynx. After
issuing through the foramen rotundum, the nerve crosses to the
infra-orbital canal (Fig. 1380, 54), which it traverses, and then
divides and goes to the parts adjacent. The anterior and posterior
dental branches supply the teeth.

Connected with this nerve is a_ structure called the spheno-
palatine ganglion—or Meckel’s ganglion—which is placed outside the
spheno-palatine foramen.

The THIRD BRANCH of the trigeminal (Fig. 180, 5c), which is
the largest branch, is termed the INFERIOR MAXILLARY NERVE. It
passes through the foramen ovale, and supplies the ear, side of the
head, lower lip, gums, teeth, salivary glands, and inside of the mouth.

As has been said, it is this part with which the smaller, or motor,
root of the trigeminal alone unites. After such union, which
takes place just outside the foramen ovale, it subdivides into two
poitions. ‘The smaller of these (which conveys a motor influence
alone) goes to the masticatory muscles; the larger again subdivides
into three nerves.

The first of these, the auricwlo-temporal nerve, passes backwards,
under the external pterygoid muscle, and then upwards between the
mandible and the external meatus, underneath the parotid gland.
There it divides, and its ramifications extend up in the temporal region.

The second, or gustatory nerve (Fig. 130, gv), which ministers to
taste, descends beneath the pterygoid muscles to the side of the
tongue, passing above the deep part of the submaxillary gland and
crossing Wharton’s duct.

In the early part of its course this nerve is joined by a slender
branch from the seventh nerve, called the chorda tympani (Fig.
130, Ct).

The third, or tnferior dental nerve (which is the largest of the
divisions of the third branch of the trigeminal), descends outside
the gustatory nerve and enters the inferior dental canal and supplies
the lower teeth (Fig. 130, in.d). |

Before entering the canal it gives off the mylo-hyoid branch
(mh), which runs down the inside of the mandible to the mylo-
hyoid and digastric muscles.

A branch of the inferior dental foramen escapes outwards at the
mental foramen and supplies the adjacent muscles.

§ 18. The sixtH NERVE (Figs. 128 & 130, °), called also the
ABDUCENs, seems again to take its origin from the floor of the fourth
ventricle. It comes to the surface at the hinder margin of the pons
Varolii, between that margin and the anterior pyramid and olivary
body of the same side of the medulla oblongata.

The nerve passes forwards and enters the orbit through the
sphenoidal fissure, and is distributed to the external rectus and the

choanoid muscles of the eyeball.
T

274 THE CAT. | [ouAP. IX,

The SEVENTH, or FACIAL nerve (called also the portio dura, when
reckoned as one with the auditory nerve) has its deep origin in the
medulla oblongata between the restiform and olivary bodies, and
perhaps from the outer wall of the fourth ventricle.

It comes to the surface from the corpus trapezoideum (Fig. 128,
VIZ.) just outside and slightly behind the origin of the sixth nerve.
Entering the meatus auditorius internus, it proceeds through the
aqueduct of Fallopius, and emerging at the stylo-mastoid foramen
(Fig. 130, %), penetrates the parotid gland, when it divides (behind
the mandible) into two branches, the subdivisions of which ramify
over the side of the head, face and neck, going to the muscles
of the ear, scalp, mouth, nose, and eyelids, and also to the platysma
myoides (Fig. 88, 7). |

Near its exit from the aqueduct it gives off a slender branch,
called the chorda tympani, which enters the hinder part of the
tympanic cavity (by a canal opening close to the bony frame of the
tympanic membrane), crosses that membrane and that process of
the malleus which is called the manubrium,* and finally escapes
through the fissura Glaseri to join the gustatory nerve—as already
mentioned.

§ 14. The r1cHTH, or AuDITORY nerve (called also the portio mollis,
when reckoned as one with the auditory nerve), has its deep origin in
the floor of the fourth ventricle. It also receives accessions by fibres
from the restiform body and, perhaps, also from the pons. It emerges
from the surface of the encephalon behind the pons, from the corpus
trapezoideum (Fig. 128, VIIL.), just behind and external to the
emergence of the seventh nerve. It enters the meatus auditorius
internus along with the seventh nerve, and bifurcates at the end of
that canal, one part going through the anterior part of the eribriform
lamina to the cochlea and the other through its hinder part to the
vestibule, as described in treating of the organ of hearing.

§ 15. The NINTH, or GLOSSO-PHARYNGEAL nerve (Figs. 128, LX., and
130, °), has its deep origin in the grey matter of the posterior part
of the medulla oblongata. It quits the surface of the encephalon
just behind (and below) the origin of the seventh nerve, emerging
behind the upper part of the olivary body and superficially connected
with the restiform body. It quits the skull by the jugular foramen,
and then descends between the carotid artery and the jugular vein,
but turns forwards and inwards at the lower border of the stylo-
pharyngeus muscle, and goes to the tongue, passing under the
hyoglossus muscle and being distributed to that organ and to the
tonsil and pharynx.

The TENTH, or PNEUMOGASTRIC nerve (Figs. 128, X., and 130, 1°),

called also the par vacum, is the longest of all the, nerves of the
encephalon, extending downwards as far as the stomach. Its deep

origin is situated in the grey nuclei of the hinder part of the medulla —

* For the explanation of these terms, see the description of the internal ear,
infra, p. 298.

~

cHAP. Ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 275

oblongata, nearer the middle line than the origin of the ninth nerve.
Superficially it arises from the restiform body, close to and immedi-
ately below the ninth nerve, and springs from a considerable number
of roots—in a series one below another, forming a flat fasciculus.
It passes out ot the jugular foramen beside the ninth nerve. It
developes two ganglia; one near its root and one (Fig. 130, gpv)
on its trunk.

It then descends the neck between the internal jugular vein and
carotid artery and passes into the thorax above the innominate vein
and root of the lung, whence it passes down the cesophagus, in the
posterior mediastinum, to the stomach.

Pharyngeal and laryngeal branches go to the pharynx and larynx
respectively. ;

Cardiac branches pass down to the heart, both from the cervical
and thoracic parts of the nerve.

Pulmonary branches are given off to the lungs, the largest ones
being those which pass to those organs on the hinder aspect of the
lung root.

The cesophagus also receives branches from the pneumogastric,
termed esophageal, on both sides of the lung root.

The nerve ends in its gastric branches. The left pneumogastric
passes backwards on the ventral aspect of the cesophagus and is
distributed over the ventral side of the stomach (some fibres going
to the liver) while the right pneumogastric descends on the dorsal
aspect of the cesophagus and is distributed over the dorsal side of
the stomach—some fibres going to the spleen.

The ELEVENTH, or SPINAL ACCESSORY nerve (Figs. 128, XJ., and
130, |), is a comparatively insignificant one. It takes origin lower
down than any other nerve reckoned as belonging to the encephalon,
namely, below the foramen magnum, from the side of the myelon,
by a series of delicate roots. Ascending into the skull through the
great occipital foramen, it passes out again through the jugular
foramen, in two divisions. One division is completely united with
the pneumogastric—the union commencing at the ganglion of the
root of that nerve and being completed below the ganglion of its
trunk. The other division turns backwards and supplies the sterno-
mastoid and trapezius muscles.

The TWELFTH, or HYPOGLOSSAL nerve (Figs. 128, X7Z.,and 180, *),
is the nerve of the muscles of the larynx and hyoid, including the
tongue, to which it conveys motorimpulses. Its deep origin is in the
grey matter of the posterior part of the medulla oblongata, close to
the posterior fissure. Its fibres are said to undergo a partial decussa-
tion in the floor of the fourth ventricle. It quits the encephalon by
scattered roots which come forth between the anterior pyramid and
the olivary body in a line with what we shall find to be the anterior
roots of the spmal nerves situated below. The roots collect and pass
through the anterior condyloid foramen. Thence the nerve descends
to the inferior margin of the digastric and then turns forwards and
runs, above the hyoid, to the‘under part of the tongue.

T2

276 THE CAT. CCUAP. 1X.

§ 16. Here it may be well to present a preliminary suMMARY oe
the nerves of the encephalon with respect to their functions, although
the functions of the nervous system and of its main divisions will be
described more fully later.

The twelve nerves just enumerated may be divided into thee
categories: (A.) Those which minister to special sense; (B.) those
which are motor, and (C.) those which minister both to common
sensation and to motion.

The nerves which minister to special sensation are the first,

second, eighth, the gustatory branch of the fifth, and the tongue
branches of the glosso-pharyngeal.
The third, fourth, sixth, seventh, and. twelfth, are motor nerves.

The fifth, glosso-pharyngeal, pneumogastric, and spinal accessory -

nerves are all both motor and sensory, though the glosso-pharyngeal
is mainly sensory.

§ 17. The sPrNAL NERVES arise systematically, in pairs, from
opposite sides of the spinal marrow. They are related m number to
the divisions of the axial skeleton, or vertebre, and (as has been
said in describing that skeleton) they pass out of the neural canal
in the intervals between the neural arches. They are severally
reckoned as cervical, dorsal, lumbar, sacral, or caudal, according to
their proximity to similarly ‘named vertebra, each nerve taking the
name of that vertebra which forms the anterior boundary of its place
of exit. Thus, inasmuch as one spinal nerve comes out above (in
front of) the atlas, there are eight cervical nerves, thirteen dorsal,
seven lumbar, and three sacral, while the rest are caudal.

The spinal nerves each arise by two roots, and each, after leaving

the neural vertebral canal, divides into two conspicuous branches —

(one dorsal and the other ventral), besides sending a twig to the
sympathetic.

Of these two series of conspicuous branches it is the ventral series
which constitutes the nerves of the limbs, while, in the interval
between the limbs, the ventral branches pass round in the body wall
—the thoracic ones in the intercostal spaces, and the abdominal ones
between the internal oblique and transversalis muscles, as will be
shortly described.

The roors by which each spinal nerve arises are (as has been —

said) two in number: one anterior (ventral), and the other posterior
(dorsal), and each is made up of a number of small bundles (/un-
cult) of nerve-fibres.

The funiculi of the posterior (dorsal) root come forth from the
posterior lateral furrow. They are larger and more numerous than
are the funiculi of the anterior root. Within the substance of the cord
the fibres of the posterior—or dorsal—root of each nerve may be traced

diverging in three directions, namely, postaxially, or away from the -

brain, preaxially, or towards the brain, and transversely across. The
first pass along the grey matter to the anterior cornu and anterior
white columns. The second advance through the grey matter to the
posterior columns. The third (transverse fibres) enter the posterior

7. are ee

Fo
~
a

cHAP. I1x.] NERVOUS £YSTEM AND ORGANS OF SENSE. 277

cornu, and some cross the posterior commissure and reach the
posterior and lateral columns of the opposite side.

The funiculi of the anterior (ventral) root pass straight to the
anterior cornu and there also diverge postaxially, preaxially, and
horizontally.

The funiculi of the posterior (dorsal) root unite to form a single
cord, which is furnished with an oval mass of grey matter, or
ganglion, varying in size with the size of the nerve.

The funiculi of the anterior (ventral) root unite together without
developing any ganglion, and the cord so formed unites with that
from the posterior root beyond (i.e., distally to) the ganglion.

Each spinal nerve having thus been formed by the union of its
roots, divides (as before said) mto two conspicuous branches termed
its DORSAL and VENTRAL PRIMARY Divisions. Fibres from each of
the two roots are so blended in the part:where the nerve is single, that
after its division each of its two parts contain fibres derived from both
the anterior (ventral) and posterior (dorsal) root of the nerve.

The DoRSAL PRIMARY DIvisions of the spinal nerves are dis-
tributed to the muscles and’ skin of the dorsal region, and divide into
internal and external branches.

The cervical internal branches pass upwards in the vicinity of the
neural arches. The external branches pass outwards, and supply
the cervical prolongations of the erector spine.

The dorsal internal branches proceed between the multifidus
spine, and either the semi-spinalis dorsi or the longissimus dorsi—
therefcre in the vicinity of the neural arches. Their external
branches (which become bigger from before backwards) pass be-

neath the longissimus dorsi to the interval between it and the

sacro-lumbalis or its continuation forwards.

The @wmbar internal branches pass backwards close to the zyg-
apophyses into the multifidus spine, therefore close (once more) to
the neural arches. Their external branches enter the erector spine,
which represents the longissimus dorsi and sacro-lumbalis un-
differentiated.

The sacra/ external and internal branches are distributed in an
analogous manner.

The VENTRAL PRIMARY Divisions of the spinal nerves are dis-
tributed to the more ventrally situated parts of the body, and they
are generally a good deal larger than are the dorsal primary divisions.
They do not divide into an internal and external branch as do the
dorsal primary divisions of the spinal nerves, but they tend to unite
together in sundry plexuses, and each gives off a minute branch
inwards to the sympathetic system, and thus in a certain sense even
these anterior primary divisions bifurcate; they bifurcate, namely,
into a large outer division, and a minute inner one going to the
sympathetic. :

The ventral primary divisions of the cervical nerves pass out-
wards between the scaleni and the rectus anticus major muscles.

The first four or five form an interlacement called the cervical

EEE “_. i——_—

278 THE CAT. . [CHAP, IX:

plexus, placed opposite the first four vertebrae below the sterno-
mastoid muscle, and connected, near the skull, with the pneumo-
gastric, hypoglossal, and sympathetic nerves.

The fifth and sixth cervical nerves give off a branch called the
phrenic nerve, which passes backwards between the pleura and the
pericardium, and is distributed to the diaphragm.

§ 18. The three posterior cervical nerves unite to form an inter-
lacement called the BRACHIAL PLEXUS, which is of much greater size
than the cervical plexus, and
gives origin to the nerves of the
FORE-LIMB. It is reinforced by
the first dorsal nerve, and the
plexus extends down from the
lower part of the neck to the
axillary space.

The connexions formed by the
nerves in the plexus are some-
what apt to vary, but the fol-
lowing conditions appear to be
normal. A large branch from
the eighth cervical nerve unites
with the main branch of the
first dorsal to form a trunk
which (after giving off a small |
branch to help to form the me-
P Soule dian) continues on as the waar

ee eh

D

Fig. 131.—D1aGRAM OF THE RIGHT BRACHIAL
’ PLEXUS.

6C, 7C, and 8C. Sixth, seventh, and eighth cer-
vical nerves.

1D. First dorsal nerve.

cf. Circumflex nerve.

ic. Internal cutaneous nerve.

m. Me:lian nerve.

mc. Musculo-cutaneous nerve.

ms. Musculo-spiral nerve.

7. Nerve to rhomboideus muscle.

rb. Respiratory nerve of Bell.

nerve (Fig. 131, 7). Delicate
branches from the first dorsal -
and eighth cervical also unite
to form the internal cutaneous
nerve (ic). The median nerve is
formed by the junction of the
small offshoot from the ulnar
(already mentioned), with a
branch from the seventh cer-

sb. Subscapular nerves.
sps. Supra-scapular nerve.
v. Ulnar nerve.

vical nerve. The largest branch
of the seventh, however, unites
with a considerable branch from the eighth cervical to form the
musculo-spiral nerve. From close to the root of the seventh cervical
the external respiratory nerve of Bell passes backwards. The musculo-
cutaneous nerve is formed by the junction of slender branches from
the sixth and seventh cervical nerves, and from the junction of two
stouter branches from the same two nerves there arise the circumflex
and the subscapular nerves. Another subscapular nerve is formed
by the junction of very slender branches from the sixth and seventh
cervical nerves, while from the sixth there springs a very consider-
able supra-scapular nerve, and a small branch which goes to the
rhomboideus muscle. ;

The internal cutaneous nerve, as its name implies, passes to the

cHAP. 1x.] NHRVOUS SYSTEM AND ORGANS OF SENSE. (i

skin of the inner side of the arm. It pierces the fascia and becomes
cutaneous at about the middle of the inner side of the upper arm,
and is distributed to both the anterior and posterior surfaces of the
limb below the elbow.

The external respiratory nerve of Bell, or posterior thoracic nerve,
at first traverses the scalenus muscle and then passes backwards
within (¢.e., nearer the ribs than) the rest of the brachial plexus to
the side of the thorax, where it hes upon the serratus muscle, which
it supplies.

The swpra-scapular nerve passes between the trapezius muscle to
the dorsal surface of the scapula, and supplies the supra and infra-
spinatus muscles.

The subscapular nerves pass to the inner side of the blade-bone,
and supply the subscapularis, teres major, and latissimus dorsi
muscles.

The musculo-cutaneous nerve descends obliquely through the
biceps and brachialis anticus muscles to the outer side of the fore-
limb. It supplies the muscles named as well as the coraco-brachialis,
and then proceeds to the skin of the outer side of the limb below the
elbow. :
The ULNAR nerve passes down on the mner side of the brachial
artery to the middle of the upper arm, and then turns backwards to

between the olecranon and inner condyle, where it 1s subcutaneous.

It then descends the lower arm (side by side with the ulnar
artery), supplying, in its course, the flexor profundus digitorum and
the flexor carpi ulnaris muscles, Arrived at about the lower third
of the ulnar artery, it bifurcates into a dorsal and a palmar branch.
The dorsal branch divides at the carpus into two branchlets, one of
which runs along the outside of the fifth digit, and the other (after
receiving a branch from the radial) subdivides and runs along the
inner side of the fifth, and the outer side of the fourth, digits. The
palmar branch passes within the pisiforme, and divides into branchlets,
which go to the muscles of the pollex and fifth digit and to the inter-
ossel; another passes along the outside of the fifth digit on its
palmar aspect; another similarly supplies the contiguous sides of the
fourth and fifth digits, and sends a twig to the median nerve.

The mEpIaNn nerve descends and passes through the internal
condyioid foramen of the humerus. It then dips below the pronator
teres, and proceeds amidst the flexor muscles to the wrist;
when beneath the annular ligament it divides into three branches.
On its way it supplies the pronators, the radial carpal flexors, and
the long flexors of the digits where not supplied by the ulnar
nerve. Of its three branches, the most internal goes to the pollex
and the adjacent palmar border of the index digit. The middle
branch descends into the second interosseous space. and supplies the
contiguous sides of the index and middle digits. The third branch
similarly supplies the adjacent sides of the third and fourth digits
on their palmar aspect.

The circuMFLEX (or avzillary) nerve passes backwards at the

280 THE CAT.

lower margin of the subscapular muscle (with the posterior eir-—
cumflex artery) between the scapula and teres major, and goes to
the deltoid, teres minor, and skin of the shoulder.

The MUSCULO-SPIRAL nerve is that supplying the supinator and

Fig. 133.—DiacraM oF THE Lerr LUMBAR
AND SACRAL PLEXUSES.

4Z, 5Z, 6£L and 7L. Fourth, fifth, sixth, and
seventh lumbar nerves.

1S and 2S. The sacral nerves.

ec. Anterior crural nerves.

cd. Caudal nerves.

ec. External cutaneous nerve.

gc. Genito-crural nerve.

gl. Gluteal nerve.

Fig. 132.—Nerrves or Ricut Forr-paw— gs. Great sciatic nerve.
PALMAR ASPECT. ile. Hlio- hypogastric nerve.
m. Median nerve supplying pollex, index, ili. Tlio-inguinal nerve.
medius, and part of annulus, digits. . Pudie nerve.
um. Ulnar nerve supplying the minimus and the pz. Nerve to psoas muscle.
other part of the annulus, digits. ss. Sinall sciatic nerve.

extensor muscles, as well as the skin of the back of the lower part of

the upper arm, and that of the back of the fore-arm and paw. It takes
origin above the vessels of the axilla, and passes round the back of
the humerus to the radial side of the front of the fore-arm, when it
descends between the supinator longus and the insertion of the
brachialis anticus, and then divides into the radial and posterior
inter-Ossecous Nerves.

The former of these (radial) passes down the fore-arm outside the
radial artery, and hidden by the supinator longus, till near the wrist,
where it becomes subcutaneous, and is distributed to the dorsum of
the pollex, index, and median digits. One branch goes to the pollex

CHAP. Ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 281

and adjacent dorsal border of the index, and another branch supplies
the adjacent sides of the index and third digits, and the radial side ot
the fourth digit, also giving off a branchlet to join the dorsal branch
of the ulnar nerve.

The posterior interosseous nerve passes through the supinator
brevis to the back of the fore-arm, where it divides, and is dis-
tributed to the muscles of that region.

The ventral primary divisions of the DORSAL, or THORACIC NERVES,
pass out in the intercostai spaces along with the intercostal blood-
vessels, the last passing along behind the last mb. ‘They soon dip
between the internal and external intercostal muscles, and each
gives off a twig to the skin at a point about midway between the
vertebral column and the sternum. The more posterior of the thoracic
nerves enter the abdominal wall, and go to the margin of the rectus,
passing, on their way, between the internal oblique and the trans-
versalis. They enter the rectus and send small branches to the
skin. The last dorsal nerve sends back a branch which unites with
the first lumbar, and so joins in what is called the lumbar plexus.
Each thoracic spinal nerve sends a short twig, inwards and down-
wards, to join the sympathetic.

§ 19. The ventral primary divisions of fhe LUMBAR NERVES are
larger than those of the dorsal nerves. They severally give otf a
filament to the sympathetic, and then unite in loops to form a
continuous, complex interlacement of branches, called the LUMBAR
and SACRAL PLEXUSES, whence come the nerves of the HIND-LIMB.
The lumbar plexus lies on the ventral aspect of the lumbar transverse
processes, and is formed by the fourth, fifth, sixth, and seventh lumbar
nerves. The fourth lumbar nerve, after giving off a branch which
divides into the ilio-hypogastric and tlio-inguinal nerves (Fig. 133, de
and i/i), sends a branch backwards, which joins the root of the fifth
lumbar nerve. From this junction the long genito-crwial nerve (gc) is
given off, and shortly afterwards that called the erternad cutaneous. The
trunk then bifurcates, its two branches joing the two branches into
which the sixth lumbar nerve divides. The larger pair of branches
thus joining, give origin to the anterior crural nerve (ac), while a
small twig to the psoas muscle is given off by that root of the
anterior crural which is contributed by the fifth lumbar nerve. The
other two branches from the fifth and sixth nerves unite to form a
branch which gives off the obturator nerve (ol). and then passes
backwards to join the seventh lumbar nerve, the thick trunk result-
ing from their junction being called the /umbo-sacral cord, and con-
stituting the main root of the great sciatic nerve.

It is called “ lumbo-sacral”’ because the nerves which come out of
the anterior sacral foramina are reckoned as forming by themselves
a sacral plexus, which plexus is placed in communication with the
lumbar plexus by means of this “ lumbo-sacral cord.”

From the outer side of this “ cord”? the pudie and gluteal nerves
are given forth. The two sacral nerves unite together—after the
second sacral has given off some branches to the tail (cd)—to form

282 THE CAT. ; [CHAP IX,

a small trunk, which unites with the large lumbo-sacral cord, and
forms the great sciatic nerve, the /esser sciatic nerve being given off
close to the junction of the “ small trunk ” just mentioned, with the
lumbo-sacral cord (ss).

The sacral plexus lies on the ventral surface of the pyriformis
muscle.

The ¢lio-hypogastric nerve comes forth from the anterior part
of the psoas, pierces the transversalis, and divides—branches coming
to the surface in the skin of the hinder part of the abdomen. The
ilio-inguinal nerve follows a very similar course to the last, but is
distributed to the skin of the groin and external generative organs.

The genito-crural nerve, which is a very long one, passes back
beneath Poupart’s ligament, one part goes to the skin of the thigh |
and the other part to the spermatic cord in the male, and to the
vicinity of the vaginal orifice in the female. The external cutaneous
nerve also passes back beneath Poupart’s hgament and goes to the
skin outside the hip and thigh.

The obturator nerve, which is of large size, passes along the
side of the pelvis, with the obturator vessels, and perforates the
obturator membrane, being distributed to the external obturator
muscle, the pectineus gracilis, and the adductor. The anTERIOR
CRURAL nerve is the great nerve of the front of the thigh, and is the
largest of those which quit the lumbar plexus. Coming out from
the psoas it passes down and divides, giving off nerves to the skin of
the front and inside of the thigh, to the skin of the inner side of the
leg and foot, and also branches to the sartorius, pectineus, and
quadriceps extensor muscles. The sewperior gluteal nerve passes
out in front of the pyriformis, and is distributed to the glutei
muscles.

The GREAT scIaATIC nerve, which is the largest nerve in the
body, passes out through the sacro-sciatic notch behind the pyri-
formis muscle, and proceeds between the great trochanter and the
tuberosity of the ischium, beneath the gluteus maximus, and (with
the sciatic artery) resting upon the obturator internus and quadratus
femoris muscles. It descends beside the adductor magnus to the
popliteal space, bifurcating into two branches, called respectively
the internal and external popliteal nerves. The first of these (which
is the larger) continues down behind the popliteus muscle, and then
takes the name of posterior tibial nerve, descending near the pos-
terior tibial artery to the inner malleolus, and dividing into the
internal and external plantar nerves. The former of these accom- —
panies the internal plantar artery, and is distributed to the three
inner (or tibial) toes, and to the inner side of the fourth. The
external plantar nerve goes to the fifth toe and outer side of the
fourth, after crossing obliquely beneath the sole with the external
plantar artery. The posterior tibial nerve supplies all the flexor
muscles of the foot and toes, and the skin of the sole of the foot
and part of the back of the leg. The second division of the
popliteal nerve, 7.¢., the external popliteal, or peroneal nerve, curves

CHAP. Ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 283,

round the head of the fibula beneath the peroneus longus and
divides into two branches. The first of these, called the musculo-
cutaneous nerve, descends between the extensor longus digitorum and
the peronei muscles to the dorsum of the foot, where it ramifies. It
supplies the peronei and skin of the front of the leg and dorsum of
the foot. The second division of the external popliteal nerve is
called the anterior tibial. It passes obliquely inwards beneath the
extensor longus digitorum, and descends with the anterior tibial
vessels to the ankle, where it divides, one part continuing on to the
first interosseous space, the other passing outwards obliquely beneath
the extensor brevis. It supplies the tibialis anticus and the extensors
both long and short, as well as the skin of part of the dorsum of
the foot.

Of the smaller branches from the sacral plexus, the pudie nerve
is that which supplies the generative organs and adjacent parts.
The other nerve, the origin of which has been mentioned, is the
small sciatic nerve, which arises behind the pyriformis, descerds
beneath the gluteus maximus, and gives branches to that muscle
and to the skin of the lower part of the buttock and back of the
thigh. )

§ 20. The NERVES OF THE TAIL come from the sacral plexus,
which gives origin to a lateral nerve which runs along each side of
the tail, giving off branches to the muscles. The more anterior
part of the tail is also supplied by branches of the cauda equina,
which are continued into it.

§ 21. The syMPATHETIC sysTEM consists of an immense number
of small nerves (of pale fibres), with many ganglia scattered through
the body, and specially connected with the viscera and blood-vessels,
the whole system being connected with the spinal system of nerves
by two elongated, gangliated cords, which extend from before
backwards, one on each side of the ventral aspect of the skeletal
axis, from the pre-sphenoid to the tail. It is with these two longi-
tudinal cords that the several filaments already noticed as passing
from the spinal nerves close to their roots, unite. The sympathetic
visceral nerves, in passing to the organs which they supply, traverse
those folds of membrane (the mesenteries) which, as we have seen,
suspend the viscera from the backbone.

In the trunk, the sympathetic nerves and ganglia are here and
there congregated together, forming great plexuses, whence other
nerves proceed.

In the head, filaments of the sympathetic communicate with
all the cranial nerves (except those nerves of special sense, the
“optic’”’ and “ olfactory” nerves), and where these unions take
place, certain ganglia are developed.

The corps, placed symmetrically one on each side of the ventral
aspect of the vertebral column, from the base of the skull to the
tail, each developes ganglia, which in the trunk correspond in
number with the dorsal and lumbar vertebrae. These cords are
connected in front with sympathetic nerves of the skull, while

284 THE CAT. | [CHAP. IX. palin

posteriorly they meet together and terminate in a single elongated
canglion beneath the tail.

The filaments which unite the several ganglia with the several
spinal nerves are formed partly of white and partly of grey fibres,
and the same is the case with the horizontal cords which connect
together, on each side, the series of ganglia. The white fibres are
deemed to come from the spinal system.

In the neck, the sympathetic is intimately connected with the
pheumogastric.

The great PLExusEs of the sympathetic are three in number: one |
in the thorax, called the cardiac plexus; one in the abdomen, called
the solar plexus ; and one in the pelvis, called the hypogastric plexus. *
Fach is a single, median structure, and each furnishes sympathetic
nerves to adjacent viscera.

The rHoracic PARTS of the gangliated cords, lie on a line with
the heads of the ribs, between the pleura and the intercostal vessels.
Occasionally two of the ganglia of each side may coalesce.

The branches given off by the first five or six gangha go mostly
to the aorta and adjacent parts, and are small in size; but those of
the more posterior ganglia join together to form on each side the
splanchnic nerve, which penetrates the diaphragm and goes to a
special ganglion, called ‘ semilunar,’ which is situate in the solar
plexus. .

The LuMBAR PARTs of the ganglated cords approach each other,
lying on the ventral aspect of the bodies of the vertebrae, along the
inner margin of each psoas muscle. In the sacrax region the cords
are much smaller, and they approach each other yet more, uniting
together in a single median ganglion (ganglion impar) beneath the tail.

Of those complex entanglements of nerves and ganglia, the great -
plexuses, the first, or CARDIAC PLEXUS, lies on the base of the heart
and on the aorta and pulmonary artery. It receives the cardiac
branches of the pneumogastric nerves, with the cardiac branches from
the cervical ganglia of the sympathetic. It constitutes the nervous
system of the heart.

The souar (or EPIGASTRIC) plexus is the largest of all, and lies in
the anterior part of the abdomen, between the stomach, aorta, and
piliars of the diaphragm, and between the suprarenal capsules. It
receives not only the splanchnic nerves, but also some branches from
the pneumogastric. It contains several ganglia, the two largest of
which are called semilunar. It gives off very many branches, ac-
companying the arteries to the different abdominal viscera.

The nuypocastric plexus is that which furnishes sympathetic
branches to the pelvis, and les between the right and left iliac arteries.
It receives branches from the lumbar part of the gangliated cords,
and from the plexuses in front. Unlike the solar plexus, this one
contains no ganglia. It sends backwards two prolongations, one on
each side of the pelvic viscera, these prolongations forming what 1s
specially called the pelvic plexus, nerves of which are spread about
the pelvic viscera, especially the bladder and generative organs.

cHaP. Ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 285

The sympathetic system may be regarded either as a separate
system or as but a series of internally directed branches of the
spinal nerves of each side of the body. According to this latter
view, each spinal nerve divides into three branches. One of these
branches passes upwards as a dorsal nerve; another follows the
body wall—the ventral branch of each spinal nerve—while the third
branch (hitherto called the filament to the sympathetic) passes in-
wards in the line of the mesenteries. These last inner branches or
filaments are serially connected by horizontal nerves, 7.e., by the two
longitudinal gangliated cords.

The sympathetic filaments which ramify around the arteries are
termed the vaso-motor nerves.

THE ORGANS OF SPECIAL SENSE

§ 22. Feelings of different kinds will be more fully considered
amongst the functions of the nervous system, but their existence
must be recognized in treating of the organs which minister to them,
and these have now to be considered. .

The special onGAN OF ToUcH is the skin, above all the skin of
the muzzle, tongue and digits. The nerves = the vibrisse and the
touch corpuscles are the agents which induce this sensation.

The structure of the skin, with its papillee, the touch corpuscles and

Paciniau bodies have been already described in the second chapter.

The nerves at their ultimate terminations in the skin, divide, and
may form small terminal plexuses, or enter touch corpuscles or
Pacinian bodies (as earlier described), or termmate in end bulbs,
which are spheroidal bodies about =3, of an inch in diameter.
Each of these consists of a capsule of connective tissue, with nuclei
—the capsule containing a core of clear, soft, granular matter.

§ 23. The orGAN OF TASTE is, in the main, the tongue, especially
its back part, but the under surface of the soft palate also seems to
participate in the faculty. The tongue with its three kinds of
papille, has been already described. It is supplied with three
nerves: (1) the gustatory, (2) the lingual branch of the glosso-
pharyngeal, and (3) the hypoglossal. The last is motor, but the first
two are sensory. The gustatory nerve goes to the mucous membrane
and papille of the fore-part and sides of the tongue, the lingual
branch of the glosso-pharyngeal goes to the mucous membrane at
the base and side of the tongue, and especially to the circumvallate
papille.

The soft palate and also the anterior pillars of the fauces, have
short, soft papille on their mucous membrane, and these parts are
supplied with fibres from the superior maxillary and glossu-pharyn-
geal nerves.

The parts, however, which by their contact with foreign bodies
are the actual ultimate occasions of the sense of taste are certain
minute structures called GUSTATORY CELLS, which are enclosed in
other structures called GusTatory BuLBs. These latter are very small

286 THE CAT. | [OHAP. Ix.

spheroidal capsules situated beneath the epithelial surface, and
opening upon that surface by a minute aperture termed the gustatory
pore. These bulbs lie in sheltered situations, such as e.g., in furrows
on the tongue and in the outer (lateral) surfaces, of the cireumval-
late papilla—the pores opening into the fossa surrounding each such
papilla. There are some hundreds of such circumvallate gustatory
bulbs, while comparatively few are found upon the fangiform
papilla. Hach bulb encloses a number of horny, spindle-shaped —
bodies, with their apices directed towards its pore. These are called
investing cells, and are of epithelial nature; they serve to enclose
and protect the actual gustatory cells, each of which is a spheroidal
mass of protein substance, ending above (distally) in a rod-like
filament. These filaments about reach to the aperture of the
eustatory pore. At their base or proximal end each gustatory cell
gives off a minute filament, which becomes continuous with one of
the ultimate ramifications of the nerves of taste.

Thus the ultimate organs of taste appear to be so many minute
rods proceeding from cells.

§ 24. The orGANS OF SMELL are contained within the cavity of
the nostrils, protected by bones and cartilages. The bones have
already been described, and extend backwards from the anterior to
the posterior nares.

The passage which connects these openings gives entrance to
currents of air, which habitually pass in through them in respira-
tion, and exclusively through them when the mouth is closed.

But these currents only pass through the lower part of the nasal
cavity, which on that account is called the respiratory portion of it.
The nasal cavity, however, ascends much above this, namely, up
between the orbits, and it is there that the sense of smell is exercised,
and into this part the odour-bearing air can only pass by the slow
process of diffusion, unless by the action of sniffing, which draws
it upwards into that upper part of the nasal cavity.

The cartilages of the nose are dependencies of the median
cartilage or cartilage of the septum, which continues on the more
posteriorly situated vertical bony septum (formed by the median
ethmoid and vomer), reaching up to the nasal bones and in front of
them. Below, it rests (in front of the vomer) on the median raised
ridge, formed by the junction of the two maxille, on the upper
surface of the maxillary part of the bony palate. Above, it expands
so as to serve as a continuation of the nasal bones, while lateral
prolongations of the median cartilage extend out, one on each side,
and are so curved (first outwards, then downwards, and then inwards)
that each nearly surrounds (while it keeps open) the lower part of
one of the nostrils. Behind, each is attached to the maxilla. On the
dorsum of the distal end of the median cartilage (between its
lateral expansions) there is a deep median groove.

The nasal fosse are those cavities the bony walls of which have
been already described. They extend from the upper surface of the
palate below, to the under surface of the cribriform palate above,

CHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 287

and are therefore higher in their middle part than either at the
anterior or posterior end—at the anterior and posterior nares. These
fosse communicate with the frontal sinuses, as has already been
noted in describing the skull. The outer wall of each nasal fossa
exhibits the three prominences formed by the superior and inferior
mass of cells of the lateral ethmoid, between which is the upper
meatus as weil as that formed by the mavxillo-turbinal, above which
is the middle meatus, while the inferior meatus is below the maxillo-
turbinal. These parts are all invested with thick mucous membrane,
so that their projection inwards and antero-posteriorly is much more
marked in the living or freshly-killed animal than it is in the dry
skeleton. .

At the roof of the fossa are the openings into the sphenoidal
sinuses into which the mucous membrane is prolonged.

- the inferior meatus is the lower termination of the lachrymal
canal.

The mucous membrane which invests the nasal fosse is called
the Schneiderian (or pituitary) membrane. It 1s very vascular, and
is inseparably united with the periosteum and perichondrium of the
different parts. At the margins of the anterior nostrils it becomes —
continuous with the external skin, while at the posterior nostrils it
becomes continuous with the mucous lining of the pharynx.

The epithelium. which coats the mucous membrane varies in
character in different places. That portion which lines the lower part
and front of the nose is lined with squamous epithelium. In the
respiratory part of the cavity (¢.c., the maxillo-turbinal bones and
all the parts below them) it is columnar and ciliated. In the olfac-
tory part of the cavity (7.e., the two masses of the lateral ethmoid
and the upper part of the septum) the epithelium is columnar but
not ciliated. The mucous membrane of this special, olfactory part
is very thick, soft and pulpy.

The sPECIAL ORGANS OF SMELL are certain peculiar bodies called
OLFACTORY CELLS, spindle-shaped, nucleated, and placed between
the columnar epithelial cells. Each such spindle-shaped cell sends
out towards the surface a rod-like process, provided with long,
slender hairlets which project slightly beyond the surface. At its
opposite pole the cell sends out a deep process, which appears to be
continuous with the ultimate ramifications of the olfactory nerves.

Thus the ultimate organs of smell appear to be so many minute
rods proceeding from cells.

The OLFACTORY NERVEs come off from the under surface of the
flattened end ofeach olfactory bulb, and piercing the cribriform
plate are distributed to the mucous membrane which invests the two
lateral masses of the ethmoid and the upper part of the median
septum. The nerves ramify in a plexiform manner over these parts,
forming a fine net-work. They are entirely composed of pale fibres,
and are finely granular. |

The rest of the mucous membrane is provided with nerves which
are ramifications of the fifth pair of cranial nerves.

oe ee a

ee SS _

288 THE CAT. koa [CHAP 1X,

Thus the maxillo-turbinals do nof minister to smell, but serve, as
it were, to strain and also to warm the air at first received within
the nostrils, and which is subsequently diffused into the truly
olfactory upper chamber.

In connection with the nasal cavity a peculiar structure, called
the organ of Jacobson, may be noticed. This is a small tubular sae
which is placed on each side of the median septum upon the nasal
surface of the palatine plates of the premaxilla and maxilla. Pos-
teriorly it ends blindly, but anteriorly it opens by the incisive
foramen into the cavity of the mouth, the mucous membrane of
which is continued into it. It receives nerves from the olfactory
bulb, which enter into its hinder end and which terminate in struc-
tures analogous to the filamentary terminations of the olfactory
nerves of the sensory part of the nasal cavity. Though these organs
open into the mouth, and not into the nasal fossee, yet they have an
essential relation to the latter, as will appear in the next chapter.

§ 25. The orGAn or sicut, the eye, consists, as has been already
said, of a globe of more or less soft tissues, into the outer surface of
which muscles are inserted—-the whole being protected and enclosed,
except in front, by dense fascia and muscle, or else by the osseous
plates which form the imperfectly closed bony socket or orbit of the
eye. Into this ball, moreover, as has already been stated, the optic
nerve enters, passing through the optic foramen to its posterior part.

In front, where the bony protection ceases, the ball is protected
by an extension of skin above and below, forming the eyedids or
palpebre. These have their outer surfaces covered by the external
skin, while each is lined internally with mucous membrane, and the
mucous membranes of both the upper and lower eyelid of each eye
are continued one into the other by that transparent membrane
which covers the front of the eyeball, and is called the conjunctiva.
Internally they are strengthened by 2 strong fibrous membrane.

The upper eyelid is raised by the special muscle called the -
“levator palpebree,’ which is supplied by a branch of the oculo-
motor nerve. <A circular sphincter muscle (the orbicularis palpe-
brarum) extends through both eyelids, and, by its contraction, closes
them. There is no special depressor of the lower eyelid. The
pot on each side where the eyelids unite is termed the angle, or
canthus, of the eye. At its inner canthus are two minute apertures
(to receive the lachrymal secretion) called puncta ¢achrymata.
There is also a large fold of membrane, or third eyelid—the plica
semilunaris or membrana nictitans—which rises from the bottom and
inner angle of the orbit and rests upon the eyeball. It has a
cartilage at its margin which strengthens it (Fig. 180, IV).

Immediately beneath the thin delicate outer skin of the eyelids,
and adherent to it, are the fibres of the orbicularis ‘muscle, and
beneath these are the fibrous membranes of each eyelid (defining
its shape and giving it firmness), and then the levator palpebree
muscle. On the inner surface of each lid are certain sebaceous
follicles, or tubes, termed Meibomian glands, which extend vertically

7
J

BS ee oh ee

cuap, 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 289 ~

on the inner surface of each palpebral fibrous membrane. Each
tube is lined by mucous membrane, and forms an oily secretion.

The conjunctiva is vascular, red, cpaque, and somewhat thick
where it lines the eyelids, but where it is reflected from them (over
the ball of the eye) it is transparent, almost colourless, and has but
very few blood-vessels. Over the coloured part of the-eye and the
pupil, the conjunctiva is quite transparent, and without vessels, and
consists almost entirely of epithelium.

The Jachrymal gland, which secretes the tears, lies at the
upper and outer part of the orbit. It is a very small racemose
gland, with ducts which open on the inner surface of the upper eye-
lid, just above the outer canthus. Tears, are a clear, saline,
alkaline fluid, with a minute portion of albuminoid matter. About
1 per cent. is the quantity of solid matter which they contain.
Having traversed the surface of the conjunctiva, the tears enter
the puncta lachrymalia (before noticed), which are the orifices o
two short membranous canals (the /achrymal canals) which pass
inwards (towards the nose), and open into a membranous tube, the
nasal duct, which descends, through the bony lachrymal canal before
described, to empty itself into the anterior part of the inferior meatus
of thenose. This canal, formed of fibrous and elastic tissue, adheres
closely to the bones it adjoins in its passage. It is lined with mucous
membrane, which is thus continuous with the conjunctiva above and
with that of the nasal fossa below. The epithelium which coats its
mucous membrane is ciliated.

The Harderian gland is a small organ situated at the inner
canthus of the orbit. It is oval and somewhat like a small bunch
of grapes. It secretes a thick, whitish fluid, which escapes from
one or two orifices which open beneath the membrana nictitans.

The eyeball is embedded in fat, from which it is separated by a
layer of fascia. It is spheroidal and composed of three investing
membranes, one within the other, enclosing certain fluid and solid
contents.

The first membrane is the sclerotic and cornea, the second is the
choroid and iris, and the third is the retina.

The fluid contents is made up of the aqueous and vitreous humours.

The solid contents is the Jens, with the capsule enclosing it. The
shape of the eye-ball is really that of a large segment of one sphere,
with a small segment of a lesser sphere affixed to it in front. The
proportion between these spheres is as eleven to seven.

The FIRST or OUTER MEMBRANE 1s partly opaque—the scLEROTIC
—while that part of it which 1s called the cornza is transparent.

The scterortic invests the larger part of the eyeball. It is formed
of very dense fibrous tissue, with elastic tissue and with stellate and
fusiform nucleated cells. By its solidity and toughness the sclerotic
maintains the globe of the eye in its proper shape. It is white
externally and smooth, except as regards the insertion of the orbital
muscles into it. Itis thickest at the back and thinnest near the
margin of the cornea. The optic nerve pierces the sclerotic slightly

U

* 290 THE ACT:

on the inner side of the antero-posterior axis of the eyeball. The
membranous sheath of the whole nerve becomes continuous with the
sclerotic, as do also the investments of the different bundles of nerve
fibres of which the whole optic nerve is composed. On this account
the part of the sclerotic where the fibres enter is called the Jamina
cribrosa. There are a few blood-vessels in the sclerotic, especially
near the margin of.the cornea. .
The cornea (or the transparent and anterior part of the fibrous
coat of which the sclerotic forms the larger portion) covers the

R CP,
Fig. 134.—DIAGRAM REPRESENTING A VERTICAL SECTION OF THE CaT’s BYE.
Scl. Sclerotic coat. Ir. The iris.

Aq. The aqueous humour
R. The attachment of the tendons of the recti Cr. The crystalline lens.

muscles. Vt. The vitreous humour.
Ch. The choroid. | Rt. The retina.

Cn. Cornea.

Cy. The ciliary processes. Op. The optic nerve.
Cm. The ciliary muscle.

anterior part of the eyeball, and has its surface rather more curved
than is that of the sclerotic. It1is also composed of fibres which are
softer and much more indistinct than those of the sclerotic, with
which they are nevertheless continuous, some fibres being opaque at
one part of their course and transparent at the other part. Between
the layers of fibres there are fusiform nucleated cells. The cornea
yields chondrin on boiling, unlike the sclerotic, which yields gelatine.
Each surface of the cornea is invested by a most delicate, structure-
less transparent membrane or: elastic lamina.. :

The sEcOND or MEDIAN membrane also consists of two parts: the
choroid and iris. The cHororp is a membrane placed within the
sclerotic, covering the sides and back of the wall of the eyeball,
except where the optic nerve pierces it. It extends forwards nearly
ito the margin of the cornea, where it ends in a number of irregular
folds, called ciiary processes. These project inwards towards the
centre of the eyeball.

The choroid is tough externally where it is connected with the
sclerotic by loose connective tissue ; internally, it is smooth and dark
coloured, being lined by a layer of dark pigment cells everywhere

(omAP ie

CHAP. IX.] NERVOUS SYSTEM AND ORGANS OF SENSE. 291
except at the ends of the ciliary processes, and at a certain consider-
able part which is called the tapetum, and is of a golden yellow
colour.* This tapetum is a roundish patch, occupying most of the
back of the inside of the choroid, and imcluding within it the en-
trance of the optic nerve, which enters towards the lower margin of
the tapetum. It is this tapetum which gives the eyes of cats that
luminous appearance in obscurity, by reflecting the light—a pro-
perty which is supposed to assist their nocturnal vision. The choroid
is an excessively vascular fibrous membrane, the vessels becoming
more minute as they advance forwards, and forming a fine capillary
network ending very near the margin of the cornea, In what is called
the ciliary ligament. This ligament i is a circular band of connective
tissue and organic muscular fibre, which unites the choroid with the
sclerotic external to it.

The arteries of the choroid come from the ophibanate artery.
Within the outer vascular layer of the choroid a layer of capillary
vessels is distinguished by the name of tunica Ruyschiana, or chorio
capillaris. Within this, again, a structureless (or slightly fibrous)
membraue named the vitreous layer is described, while inmost of all
is the pigmentary layer, of closely placed polygonal pigment cells.

The rts is that coloured part of the eye which is apparent around
the pupil, and which may be differently coloured on its front surface,
‘in different cats,t but is covered with dark pigment on its hinder or
deep surface. It consists of fibrous tissue and organic muscular
fibres. |

At its outer border the iris is continuous with the choroid and
ciliary ligament, and is connected with the cornea, while its free
inner border forms the outer margin of the pupil of the eye—it being
a sort of curtain with a hole in it, about half an inch across, sus-
pended in the more anterior part of the interior of the eyeball, and
resting on the anterior surface of the lens.

The iris is very, and very suddenly, contractile (im spite of the
organic nature of its muscular fibres), and has two muscles. The
first, or sphincter, is a flat band close to its free inner margin, and
on its posterior surface. The dilating muscle, on the other hand,
is formed of fibres which pass inwards on all sides towards the
margin of the pupil from the circumference of the iris. In ob-
scurity the pupil is widely open, with a circular opening through
contraction of the radiating fibres of the iris. In bright light the

* At my request Mr. Henry Power has
been so kind as to examine the cat’s eye
with the ophthalmoscope. As to the result
of his examination, after noting the non-

i which is a pearly spot ; the entrance of
the optic nerve. This presents the usual
vessels emerging from it. The disc is
surrounded by a sapphire klue zone of

appearance of that spot known in man
as the fovea centralis or yellow spot, he
expresses himself as follows :—‘*I owe
you thanks for directing my attention to
one of the most beautiful things I have
ever seen. Imagine a dense, yet lumi-
nous velvety- blackness below, bounded
by a nearly horizontal line, just above

intense brilliancy, passing into metallic
green; and beyond this the tapetum
shines out with glorious colours of pink
and gold, with a shimmer ot blue and of
green. It is really lovely.’

t Or even in the two eyes of the same

cat.

U2

aes: ive, nha

» VOD aa te ite, wei fae ie e | eed ere ae , aga! ois i 7 ORL
‘ + Y 4

292 THE CAT:

opening contracts more and more till it is reduced to an extremely
narrow vertical chink. This is probably due (as has been sug-
gested to me by my friend Mr. Henry Power) to the greater con-
traction of the superior and inferior radiating fibres than of those
which radiate outwards and inwards. A
muscle called the ciliary miusele consists
of a ring of radiating organic fibres which
take origin in front from the inner surface
of the sclerotic, close to the cornea, and
pass outwards and backwards to the cho-
roid membrane, opposite to the ciliary pro-
cesses. By their contraction these fibres
pull forward the choroid, and so render the
ciliary ligament less tense. The muscle
thus tends to draw the choroid and retina
together lke a bag round the vitreous
body, pressing the lens forwards, which
is supposed to be thus indirectly made
less flat. There are a few more inwardly
situated fibres which run circularly (nearly
at right angles to the rest), and fcerm
part of the cilary ligament as before men-
tioned.

Inmost of all the coats of the eyeball
lies a soft delicate membrane of nervous
matter with connective tissue—the RETINA.
It extends forwards almost to the ciliary
Bee acid axrxesewr. || DEOCOMES and ends anteriorly in a finely

‘Inc A Section or tse Re- toothed margin called the ora serrata, and
b «. Omter. or choroidal smface. lence to the tips of those processes the
in. s. Inner surface, or that uext retina is continued on by a transparent

he vi humour. vines? wee:
Layer of norve-hives at inner layer, the pars ciliaris retine, consisting

a.

be eee: oF etme large nerve. Of nucleated cells which are not nervous,
Be i iNk fee! but part of the membrana lmitans interna.

Pa aadiear liye. Slightly on the inner side of the middle of

e Omer molecular Gnter-nue'ear) the retina, at the back of the eyeyisias

PE eer on tos oval prominent spot, the porus opticus,

h. Layer of pigment cells—next where the optic nerve enters, and whence

he choroid. . :
ees alitaiih. the vessels of the retina radiate. This

is a blind spot.

The retina is an extremely complex membrane, consisting of about
seven layers of different forms of nervous tissue, supported and con-
nected by a most delicate framework of connective tissue.

The outermost layer, that which comes next to the pigment layer
just described, is what has been called the membrane ‘of Jacobson.
It consists of a multitude of minute and delicate nervous rods,
placed with their ends directed outwards and inwards. Amongst the
rods are scattered at regular intervals a less number of nervous cones,
placed with their apices outwards.

Cntr re. Mee

cHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 293

The rods stand in close apposition. The cones* are not so close
set and do not extend as far outwards as do the rods. Both structures
become shorter as they approach the ora serrata.

Within the rods and cones is a thin layer of granulated substance,
connected with the fibres in which the rods and cones end in-
ternally. This layer is the external granular, or outer nuelear layer,
within which is the znternal granular, or inner nuctear layer, formed
of nucleated cells and fibres, separated from the. former by the zntéer-
granular, or internuclear layer, formed of plexiform tissue enclosing
a few nucle: and smooth cells, with
coarser fibres running parallel to the
surface of the retina.

Within the internal granular layer,
again, is a thicker imner molecular
layer (or internal granulated layer),
which contains much connective
tissue, within which again is a layer
of ganglionic cells, and lastly and
most internally, is a layer of fibres of
the optic nerve, ramifying on the
immer suriace ot the retina,'and con= "ie. 186.— Lanmarep Stauerone or THe

RYSTALLINE LENS, SHOWN AFTER

nected with the ganglia placed ex- HARDENING IN ALCOHOL.

e = 1, Central portion.
ternal to it. This lay er of nervous 2, 2,2. Concentric lamina, which have

fibres is bounded within by an ex- become detached along the radiating
. lines of the external surface of the
tremely delicate, glossy membrane, lens.

the membrana limitans, which is

continued forwards as the pars ciliaris retine, and becomes con-
tinuous with the suspensory ligament of the lens. Doubtless the
rods and cones are continuously though complexly connected with
the ganglia and fibres of the mnermost layer.

At the point of entrance of the optic nerve (7.e., at the blind spot)
rods and cones are wanting. In the eye, as in the nose and tongue,
the special sense 1s subserved by minute nervous rods proceeding
from cells.

Filling up the great concavity bounded by the membrana limitans
lining the innermost layer of the retina is the vIrREOUS HUMOUR
(or vitreous body), forming nearly four-fifths of the ball of the eye.
This is a transparent, jelly-like, almost quite fluid mass enclosed (as
just observed) in the membrana limitans of the retina.

The vitreous humour is reducible to water with a few salts and a
little albumen. It appears to consist of concentric layers of slightly
different density, but not separated from one another by any
membraue. ;

The ckysTALLINE LENS of the eye is a transparent, doubly convex
solid structure, interposed between the posterior surface of the

* The cones must be looked upon as | which consists of a bundle of the finest
collections of nerve terminations ; they | axis cylinders, which separate in the
appear to be longitudinally striated, and | granular layers of the retina.
they pass into a thick fibre (cone-fibre),

iris and the anterior surface of the vitreous humour. It is somewhat
harder within than superficially. It consists of albuminous substance,
and is non-vascular. It is really made up of a multitude of fibres
(each a flattened hexagonal prism, about =;';= of an inch wide), with
serrated edges and a nucleus. These are so connected that the lens
is practically made up of concentric layers of fibres, as becomes
evident after immersion in alcohol. The lens is not quite spherical,
but is compressed from within outwards, that dimension being less
than its transverse diameter.

The capsule of the lens is a transparent, glassy membrane, which
is very elastic, and closely invests the lens itself. Its anterior surface
is in contact w:th the iris, its posterior surface adjoms the vitreous
humour. From the extreme circumference of the lens it sends off a
membrane, the swspensory ligament of the lens, which becomes con-
tinuous with the choroid and with the membrana lmitans of the
retina, where it has become the pars ciliaris retine, behind the ciliary
processes. It thus divides the chamber in front of the lens from
that of the vitreous humour. Just behind that part of it which
adjoins the lens, it 1s shghtly separable from the front of the vitreous
humour, and when separated leaves a space which has been called
the canal of Petit, but this 1s no true persistent canal, but only a
yielding interspace affording room for change of place in the lens,
and consequent focal adjustment.

The aquEous HuMoUR 1s the fluid which fills the front chamber
of the eye between the iris and lens, and the cornea. It scarcely
_ differs in composition from water, but contains some solids in
solution—chiefly chloride of sodium. A small portion passes
behind the iris, in what is called the posterior chamber of the
aqueous humour.

The direction of the eyes is determined, apart from the position of
the body, neck, and head, by the acrioN oF THE ORBITAL MUSCLES,
of which the vecti severally pull the cornea in four directions, while
the obliqui roll the eyeball on its axis, and pull it a little forwards
and inwards. The choanoid muscle tends to pull it backwards.
The eyelids protect the ball of the eye from foreign substances and
from excessive light, and hinder the too rapid evaporation on its
surface, the moisture of which is secured by the lachrymal secretion,
the superfluous quantity of which escapes to the nose (through the
juncta lachrymalia and nasal duct), while the secretion of the
Meibomian glands tends to check its overflow beyond the margins
of the eyelids.

The structure of the eye, AS AN OPTICAL INSTRUMENT, 1s that of
a camera obscura filled with water, with a circular aperture, behind
which is a partition, or diaphragm, with another and smaller circular
aperture immediately in front of a bi-convex lens.

The lens, according to the laws of optics, concentrates the rays
coming from every point in front of it to other poimts behind it, and
thus throws upon any surface situated at due focal distance, an
inverted image of the objects in front of it. The surface behind,

ma"

294 THE CAT. | [CHAP. 1x >,

cHAP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 295
upon which the image is thrown, is the retina, and the perfection of
the image is increased by the iris, which acts lke any other
diaphragm by moderating the light and cutting off marginal rays,
the effect of which, if admitted, would be to produce the imperfection
called spherical aberration. The organic fibres of the iris spon-
taneously act to exclude or admit light through the pupil, which
dilates in obscurity and contracts in bright lhght, in the manner
already described.

The different densities of the different media through which the
light has to pass in traversing the eye corrects another kind of
imperfection due to the scattering of colour, and renders it an
achromatic mnstrument.

Not only is the image in the eye inverted, but each eye sees any
object from a slightly different point of view. It is this grasp, as it
were, of an object on both sides by the two eyes, which gives rise to
the apprehension of solidity * and relief.

For distinct vision, the rays of ight must be brought to a focus
on the retina. Now, without moving the body, neck, or head, the
eyes can be so directed alternately to nearer or to more distant
objects as to produce distinct perception of each successively. Such
movement is the focussing of rays coming from points varying in
remoteness. The way in which this adjustment is brought about is
supposed to be by the action of the ciliary muscle, and the physical
properties of the lens. The latter is highly elastic, and tends to be
more convex in front than is ordinarily the case. The ciliary
muscle, pulling the choroid, relaxes the ciliary ligament, and
therefore the pressure of the capsule on its contained lens, which
immediately becomes more convex, and so becomes accommodated
to the perception of nearer objects.t

§ 26. The orGAN oF HEARING is divisible into three parts: the
external, the middle, and the internal ear.

The EXTERNAL EAR consists of a cartilaginous, membranous, and
muscular structure, projecting conspicuously upwards from the side
of the head, and called the pinna or auricle, together with the
passage leading inwards from the deeply situated lowest portion of
the pinna, which passage is the external meatus, or tube leading to
the internal ear.

The prnna has the form of the wall of a cone, cut obliquely down-
wards and outwards from its apex, the section being curved a little
upwards at the last, so as to make the lowest part of this conic section
almost semicircular. ‘The pinna stands up above and behind the

* It is the special artificial imitation
of two such views placed side by side at
a suitable distance, which produces the
illusion of the stereoscope, the relation of
each view to its proper eye being main-
tained. If the views be transposed, so
that the view which would naturally
present itself to the right eye be pre-
sented to the left, and vice versd, as by a

pseudoscope, then the opposite appearance
of a hollow or excavated surface is pro-
duced.

+ The above is the commonly received
doctrine on the subject ; but fishes have
a ciliary muscle, although the lens in
them is globular. It may be, therefore,
that its action is not yet correctly under-
stood.

296 THE CAT.

opening of the ear passage. It is deeply concave on the surface,
which is turned outwards and forwards, and convex on its inwardly
and backwardly-turned surface. It is hairy within and without, but
the hairs within are not numerous, though very long. Externally,

the pinna is covered with short hairs. Its inner surface presents
a variety of prominences and fossee, which aid in collecting and

concentrating the sonorous waves which impinge upon the organ.
Immediately in front and externally, at the bottom of the external

opening, is a small rounded prominence, the ¢tragus, and im-

mediately opposite it 1s a double prominence with an imtervening

concavity, the anti-tragus, mto the concavity of which the tragus

exactly fits. From the anti-tragus a low ridge runs upwards and
backwards to the margin of the pinna. A little further im, another
similar ridge runs (nearly parallel to that just mentioned) from the
margin of the pinna downwards to a very small prominence behind
the anti-tragus. Within and behind the tragus there is another
vertical undulating ridge, the wost-tragus, while between its summit
and the tragus is a deep, rounded depression.

Behind and above the summit of the post-tragus is the deepest
concavity of the concha, from the midst of which a singularly pro-
minent process, with a pedunculated appearance, projects inwards,
which process may be called the supra-tragus. A slight, short
ridge runs downwards and backwards from the lower margin of
the fossa in which the supra-tragus is placed. The cartilage of
the pinna is large and complexly-shaped, with a reduplication in

front. There is a reduplication of skin at the lower part of the.

- posterior margin of the pina, producing a sort of pouch.

The pinna 1s attached to two cylindrical cartilages, which follow
each other like two successive segments of a telescope, and form the
cartilaginous part of the meatus auditorius externus.

A distinct body, called the scutiform cartilage, is only connected
with the pinna by ligaments, yet has muscles inserted into 1 which
indirectly move the ear. It lies on the temporal fossa just behind
the orbit, with its long axis antero-posterior, and enclosed in pre-
auricular aponeurosis. It can glide to and fro in the temporal
aponeurosis.

The EXTERNAL AUDITORY MEATUS extends straight in from the
pinna to the drum of the ear, or tympanic membrane. Its outer
part is formed by cartilage, the rest by bone, as has been before
described.* At its inner end the bony tube is grooved at its sides
and floor, and into this groove the tympanic membrane is fixed.

The meatus is lined with mucous membrane, which is reflected
over the outer surface of the tympanum so as to form a cecal
mucous tube. In the bony part of the meatus this membrane is
thin, and closely adherent to the periosteum, but in its cartilaginous
part it is thicker, and bears hairs, together with sebaceous and
oleaginous glands.

* See ante, p. 64.

fi
4
rate

las

- The MIDDLE PART OF THE EAR, or TYMPANUM, has been already
described in part in the description of the temporal bone.* Itisa
chamber entirely enclosed in the temporal bone, but has certain
apertures in its walls. It is separated off from the external meatus
by the tympanic membrane, but it communicates with the pharynx
through the Eustachian tube.

The roof of the tympanum is ae by that portion of the

Fig. 7- SECTION OF THE MIDDLE AND INTERNAL EAR OF THE CAT, MUCH ENLARGED, SHOWING
THE MEMBRANOUS LABYRINTH AND ITS RELATIONS (AND THOSE OF THE Bony LABYRINTH)
TO THE SEPTUM OF THE BULLA, THE EUSTACHIAN TUBR, AND THE TYMPANIC MEM-
BRANE. (From a drawing by Mr. Alban Doran.)

The auditory ossicles are represented in outline
as if transparent. The septum of the bulla

is partly represented, but is cut away at * to
show its relation to the labyrinth. The mem-
branous labyrinth is represented by darker
shading.

Amp. Ampulla.

G€. Cochlea.

_E. c. Opening of Eustachian tube.

F.. sc. External horizontal semi-circular canal.

Fr. Fenestra rotunda. (It lies almost entirely
above the septum of the bulla. and looks
into the inner chamber; but its anterior
margin bulges into the outer chainber.)

petrous bone which immediately adjoins the squamosal.

Fo. Fenestra ovalis.

Inc. Incus.

Mal. Malleus.

Mn. Manubrium.

Mt. Mt. Outline of membrana tympani, with
manubrium of malleus touching it.

P. Sc. Posterior semi-circular canal.

Sb. Septum of bulla.

S. Sc. Superior semi-circular canal.

S. Stapes.

St. Scala tympani of cochlea.

Sv. Scala vestibuli of cochlea.

*, Cut edge of septum of bulla.

Its outer

wall has a very large opening closed by the tympanic membrane,
and in front of its margin is the inner opening of the fisswra Glaseri,
before mentioned as transmitting the chorda tympani nerve.

The tympanic membrane, which is nearly circular, les obliquely,
its outer surface looking somewhat downwards. It is very thin, and
consists of fibrous and elastic tissue, the fibres radiating from about
its centre, but there are also circular fibres, especially towards

its Be eamferenes.

The inner wall of the tympanum presents several openings and

prominences.

x
.

Towards its upper hinder part is a kidney-shaped or
oval foramen called the fenestra ovalis.

Somewhat in front of the

* See ante, p. 68.

298 THE CAT. 3 [onar. ix,

fenestra ovalis is a rounded prominence marked by grooves for nerves
and called the promontory.

Another opening, called the jenestra rotunda, lies below and
behind the promontory, and is, naturally, closed by membrane.

Above the fenestra ovalis is a small depression or fossa, in which
the stapedius muscle has.its organ. |

The anterior part of the tympanum gradually narrows and
becomes the proximal part of the Eustachian tube, which, as before
said, is the canal which places the cavity of the middle part of the
ear, mM communication with the mouth.

The Hustacutan TuBE proceeds forwards and inwards and
slightly downwards from the tympanum to the pharynx. Its
anterior or distal part consists of cartilage and fibrous membrane.

The tympanum is crossed by four small bones which proceed
inwards from the inner surface of the tympanic membrane to the
fenestra ovalis. These are the AUDITORY OSSICLES.

The outermost of these is called, from its shape, the madleus
(Fig. 138, B), and consists of a quadrangular thickened portion, the
head, with a rounded articular surface (as). Adjacent to this is a
part called the neck (n), beneath which it expands, on one side, into
a lamina of bone (/). From this extends a long, delicate, pomted
process (pg), called the processus gracilis. From the inner side of
the neck a large process (pm) projects, for the tendon of the
tensor tympani muscle. Opposite this is a slight prominence, the
processus brevis (pb), and from between these two last mentioned
processes there extends a long curved production, the manubrium
(emn), which is fixed on the middle of the tympanic membrane.

The second bone is called the dncus or anvil (Fig. 138, c), also
consists of a thickened part, with two processes. The thickened
part, or body, has a concavo-convex articular surface, which unites
with a corresponding surface on the body of the malleus, both sur-
faces being provided with cartilage united by a synovial membrane.

‘One process, the crus breve, projects backwards, and is attached
by ligament to the hinder wall of the tympanum. The other
process, the crus Jongum, which is longer, passes downwards behind
the manubrium, while its end is bent suddenly inwards and articu-
lates with a third bone, which is a minute rounded ossicle called the
os orbiculare, and which is generally anchylosed to the end of the
crus longum as the so-called processus lenticularis. The crus longum
articulates by the intervention of the os orbiculare with the fourth
auditory ossicle or stapes (Fig. 138, p), so called from its resemblance
to a stirrup. That portion of it which resembles the part of a
stirrup on which the foot rests is called its base, and the opposite end
its head, while these are connected by the two cruia which diverge
from the neck. The base is fixed by ligamentous: fibres to the
margin of the fenestra ovalis. The space enclosed between the crura
and base of the stapes, is naturally closed by a thm membrane. A
very small muscle, called the stapedius, (to be shortly described) is
inserted into the neck of the stapes.

The auditory ossicles are connected with and suspended from the
surrounding bones by delicate ligaments.

One such suspends the malleus from the wall of the tympanum,
and the incus is similarly suspended, while the stapes is connected
by ligament with the margin of the fenestra ovalis.

There are two very small muscles* connected with the auditory
ossicles—the tensor tympani and the stapedius.

The tensor tympani muscle arises from a pointed process which
projects from the free margin of the septum of the bulla as it
curves upwards at the posterior wall of the tympanum. This
process is sometimes small, sometimes rather long and pointed.
The muscle then runs forwards and is inserted into the processus
muscularis of the malleus.

Beyond the origin of the tensor tympani the septum curves
forwards and upwards and is lost on the promontory a little beyond
the fenestra ovalis.

The stapedius muscle arises from a more or less deep pit above
the fenestra ovalis. It descends almost vertically to be inserted into
the neck of the stapes.

the Eustachian tube, with that of the pharynx, and like it, is clothed
with a ciliated epithelium, except where it lines the tympanic mem-
brane. That membrane is, moreover, coated on either:side by other
membranes, being lined within by the general lining of the tympanic
cavity, as it is coated without by the membrane of the external
auditory meatus. |

The INTERNAL EAR or special auditory part of the organ of hearing
is a membranous structure enclosed in an excavation of the petrous
part of the temporal bone called the Bony LaByRinTH. This laby-
rinth consists of three parts, a central chamber, the vestibule, con-
nected with a part called the cochlea in front, and behind, with
another made up of three semicircular canals.

The VESTIBULE is a somewhat pyramidal cavity, the front part of
the inner wall of which abuts against the bottom of the internal
auditory meatus and is pierced by numerous small foramina,
which admit the filaments of the auditory nerve. At the front of the
lower part of the vestibule 1s the opening which leads to the cochlea,
while the posterior end of the vestibule shows the four openings of
the three semi-circular canals. The outer wall of the vestibule is
perforated by the fenestra ovalis, which, in the dry skull, opens into
the tympanum.

The cocuixa (Fig. 138, 4, ¢) is conical, and has the general form
of a limpet shell, with its base directed towards the internal auditory
meatus. The cone consists of a spiral tube which tapers as it
recedes from its base, winding round a central column (the modiolus),
the tube being incompletely divided by a lamina of bone, the damina

* The origins and insertions of these muscles have been carefully verified by
Mr. Alban Doran. ;

omar. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 299

The mucous membrane of the tympanum is continuous, through ©

300 THE CAT. [cHaP.
spiralis, which projects out from the modiolus towards the opposite
wall of the tube, except at its apex. It makes three revolutions
and one quarter of a revolution round the modiolus, its course
being from left to right in the right ear and from right to left in
the left ear.

The two divisions of the tube, _ meompletely separated by the
lamina spiralis, are termed “ scale.”

The lower of these is called the scala t ympani, and it commences
at the fenestra rotunda. The
other division, ealled the seala
vestibuli, commences at the ves-
tibule, with which it freely com-
municates.

The sEMICIRCULAR CANALS
are bony tubes extending
upwards and backwards from
aa the vestibule from the four

)\ c2 openings already mentioned

hi as existing m the posterior
part of that cavity.

The tubes describe about

ce! Fie oe two-thirds of a circle each,
Fig. 138.—Bony LABYRINTH AND AUDITORY and may have one end dilated
OSSICLES (ENLARGED). into whatis called an ampulla,
A. Bony labyrinth of the right ear, extracted the cavity being considerably
and reversed in position, its hinder end :
pone aig forwards, and its upper margin increased where such dilata-
fe cochlea. tion exists. The three canals
el, External horizontal semi-circular canal. = 5 4
c. Posterior vertical semi-circular canal. recelve different names, accord
ce’, Anterior vertical semi-circular canal. ing to their positions.
fi. Fenestra rotunda. i ae 7
f2. Fenestra ovalis. The Supe) tor vertica semi-
m. Ampullee. 3
B. Malleus. circular canal (Fig. 138 a, ce’).
Beet surtace.of head, arches upwards and somewhat
i, Larnina. backwards as well as inwards
pg. Provessus gracilis. :
pin. Processus muscularis. from the outer side of the
9b. Processus brévis. q : Sie . :
ee tic, skull. It is the presence of
C. Incus and orbiculare. this canal which causes a
o. Crus longum. .
D. Stapes. prominence on the upper part

of the inner surface of the
petrous part, of the petrous bone, just above the cerebellar fossa. The
more anterior and outer end of this arch is the one that dilates into
an ampulla and opens by a distinct aperture. Its posterior and
inner end joins with the upper end of the arch next to be described,
the two opening into the vestibule by a common aperture.

The posterior vertical semicircular canal (2) arches backwards
and slightly outwards, its upper end starting from the vestibule
from an aperture common to it and to the imner end of the superior
vertical semicircular canal. Its lower end opens into the vestibule
in common with the adjacent end of the external or horizontal semi-
circular canal. This last canal arches backwards and outwards and

coHAP. 1x.| NERVOUS SYSTEM AND ORGANS OF SENSE. 301

opens into the vestibule by a distinct aperture, after dilating into an
ampulla close to the fenestra ovalis (/*). Its other end joins, as
before said, with the adjacent part of the posterior vertical semi-
circular canal—the two opening into the vestibule by a common
aperture.

Within this osseous labyrinth is the true essential.part of the
organ of hearing, namely, the MEMBRANOUS LABYRINTH (Fig. 137),
which is a very complex, closed sac, corresponding generally in figure
with the osseous labyrinth within which it floats. It floats because
the osseous labyrinth encloses a fluid called the perilymph, which
fluid surrounds the membranous labyrinth, which itself encloses
another fluid called the endolymph. Both these fluids are slightly
albuminous, and the former, the perilymph, is secreted by a delicate
membrane of connective tissue, with a layer of epithelium, which
lines the osseous labyrinth and has no communication with the
lining of the tympanum (being cut off from that cavity by the
membranes which close the fenestrae) though more or less continued
into the aqueducts,

The membranous labyrinth consists, like fhe osseous labyrinth, of
three divisions; 1, that of the vestibule; 2, that of the cochlea;
and 3, that of the semicircular canals.

That part of the membranous labyrinth which is enclosed in the
vestibule, consists of two sacs connected by a narrow bent tube
(which extends into the aqueductus vestibuli) and containing within
them small .crystals of carbonate of. lime, called ofoliths or otoconia.
The more posterior of these sacs is called the urricL£, and it is into
this that the membranous semicircular canals open by four apertures,
corresponding with those of the osseous semicircular canals. The
other sac is termed the saccuLe, and a delicate tube proceeding
from it extends to and connects it with that part of the membranous
labyrinth which extends into the cochlea.

The lamina spiralis of the cochlea has its free edge connected with
the opposite wall of the spiral tube by a membrane which completes
the separation of the two scalee except at their summit, where they
communicate by a small opening called the helicotrema. The mem-
brane which thus completes the partition between the scale is
called the basilar membrane. Another delicate membrane, called the
membrane of Reissner, proceeds obliquely upwards from the lamina
spiralis to the outer wall of the tube diverging in its course from
the basilar membrane, and so cutting off a triangular canal from
the region above the lamina spiralis. This triangular canal is
called the canalis membranacea (or scala media), and it is connected
by a minute tube (the canalis reuniens), with the saccule of which it:
is a continuation—forming as it does the second or COCHLEAR PART of
the membranous labyrinth, and being filled with endolymph. Thus
the canalis membranacea ascends the cochlear spiral between the
two scale—the scala tympani ascending from the fenestra rotunda
to the apex, and there communicating with the descending scala
vestibuli, which ends in the vestibule.

302 —C THE CAT. [CHAP, Ix.

A very peculiar organ lies in the floor of the canalis membranacea,
which organ is termed the orGAN oF Corti. It lies upon the

basilar membrane, and is covered above by a delicate lamina, the

membrana tectoria. The latter separates the organ from the cavity
of the canalis membranacea with its contained endolymph.

Thus this organ, with the basilar membrane below it and the
membrana tectoria above it, forms a thickened floor to the relatively
wide canal of the canalis membranacea. The organ itself consists
partly of nucleated cells with stiff hair-hke processes, partly of
epithelial cells, and partly of two rows (one inner and one cuter) of
tough .rods (compared with cartilage in consistency), so leaning
against each other as to enclose beneath them a minute triangular
space between them and the basilar membrane. This long double

Fig. 139.—A-PAIR OF Robs oF CoRTI IN SIDE VIEW, HIGHLY MAGNIFIED.

ir. Inner rod. The nucleated protoplasmic masses at the feet
er.’ Outer rod. of the two rods are also shown resting on
the basilar membrane.

series of rods has been compared to the keys of a piano, which they
to a certain extent resemble. Thus it may be said that each fibre
of the organ of Corti consists of two filaments joined together so as
to form an angle open downwards. Cells bearing hair-like fibres
and epithelial cells are’placed on each side of this double range of
rods, and beneath the inner cells (between the inner bases of the
rods and the basilar membrane) are certain nucleated particles of
protoplasm. ;

The MEMBRANOUS SEMICIRCULAR CANALS occupy about one-third
of the space enclosed by the bony canals in which they are suspended,
and they dilate into ampulle there where the osseous semicircular
canals so dilate. The lining of epithelium exhibits cells, which each
sends forth hair-like processes projecting into the endolymph. ©

The AUDITORY NERVE, after entermg the meatus auditorius in-
ternus, divides at the bottom of that canal into two bundles of minute
fibres, which pass through the cribriform plate and are distributed
to the vestibule and cochlea.

The vestibular nerve sends twigs to definite parts of the utricle,
of the saccule, and of each of the three ampulle, and most probably
ends by becoming continuous with the cells bearing hair-like pro-
cesses, which exist in that part of each of these cavities which is so
supplied.

The cochlear nerve enters the base of the modiolus, and thence
radiates to the scala media, and most probably ends by becoming

_ ouap. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. —303-

continuous with the cells bearing hair-like processes, which have
been described as lying beside the rods of the organ of Corti.

Thus here again—as in the organs of sight, smell, and taste—the
ultimate structure which ministers to special sense is a system of
rod-like filaments proceeding from spheroidal cells.

Apart from the special.function of the ear—hearing—the various
accessory structures serve the following
purposes in aiding that function: the
pinna serves to collect the sonoroug
. waves, by its prominences and ex>
cavations, and to direct them towards

the aperture of the meatus externus.

This collecting process is greatly aided
| by the muscles, which enable the pmna
7 to be turned in various directions. At
7 the bottom of the meatus, the sonorous
| waves act upon the tympanic membrane,
the vibrations of which are conveyed
by the auditory ossicles across the tym-
: panum to the fenestra ovalis and so to
the perilymph, and, finally, through
the walls of the membranous labyrinth,
to the hair-like processes projecting
:

ae ae Tee ey 8) ae

Les —

into the endolymph of the ampulla,
and to those of the organ of Corti. The
vibrations of the rods of the last named
organ doubtless intensify the vibratory
action, as do the otoliths enclosed within
the utricle and sacculus. |
. The Eustachian tube places the air
inside the tympanum in communication
with the exterior, and so prevents undue
tension.
The stapedius and tensor tympani
muscles tend by their contraction to

Fig. 140.—DIAGRAM OF THE AUDI-

tighten the tympanic membrane and tory EPITHDUIUaE AND THE MODE
that of the fenestra ovalis, and so to Soe is a

moderate the effect of too great sound. «. Columnar epithelium,
Thus the labyrinth, with its fluid con- “EP Gwaudtory bain ee

5 ae b. Basal supporting cells.
tents, can be affected either by aérial fe ee oe assing through

ee een ee ee ee SS Se eT
‘

exist between the ear and the eye, with

certain noteworthy differences. Both are protected by skull bones,
but the ear much more completely so. Both are protected by external
folds of integuments furnished with muscles—the pinna and the
eyelids. Both are supplied by a nerve of special sense, which enters

waves through the meatus, tympanum ‘ the layer of membrane (called the
: tunica propria) immediately be-
and fenestra ovalis, or through the bones neath the epithelium, to join the
9 } | : plexus in the epithelium.
and solid structure of the head. 1. Limit of the membrane beneath
' § 27. Certain marked ANALOGIES the epithelium.
:

~~

304 THE CAT. [owaP. Ix,
them through a foramen—the internal auditory meatus and the
optic foramen. Both contain two internal fluids enveloped by proper
membranes—the perilymph and the aqueous humour, and the
endolymph and the vitreous humour. Both have a muscular
apparatus to regulate the organ according to the quantity of special
influenee brought to bear upon it—the muscles of the ossicles and
of the iris. Both have the action of the special influence intensified
by contained hard parts—the otoconia and the lens—and, finally,
both have their nerve of special sense expanded and ending in
minute filaments on the innermost membrane of their respective
structures. |

§ 28. The FUNCTIONS OF THE NERVOUS SYSTEM of the cat are
activities the existence and nature of which can be ascertained only:
(1) by more or less complex inferences deduced from what human
beings can by self-consciousness learn as to their own affections,
feelings and cognitions; (2) by conversation; (3) by the observa-
tions of pathology; and finally (4) by what can be ascertained as to
other creatures by means of experiments upon different animals.

Such inferences and observations show us that not only muscular
motion and sensation depend upon nervous influence, but that even
such functions as respiration, digestion, secretion, and excretion,
are similarly modified, and that the circulation through the body of
the nutritive fluid is greatly acted on—acclerated or retarded—by
the same influence.

For the perfect performance of all the nervous functions ‘the
integrity of the whole nervous system is a generally necessary
condition. Nevertheless, partial mutilations of different regions
of that system produce very different results, proving that all parts
have by no means the same activity, but that different parts have
different functions, and that some parts are much more necessary
than are others to the maintenance of healthy life. When the
destruction of any part of the nervous system induces the cessation
of some function, the fact of that cessation does not indeed prove
that such part is the very organ of such function, but it certainly
shows that the non-destruction of such part is a s¢ne qud non for its
performance. :

Although we find that the powers of sensation and motion are so
mixed up in ourselves that, when the body is entire, the existence
of the latter involves the occurrence of the former, while any inten-
sity of the former (sensation) produces almost inevitably some amount
of the latter (motion) ; nevertheless observation and experiment
prove that in abnormal conditions, either can occur without the
other; and the parts which minister to sensation alone or only to
motion, are severally named sENsory or motor parts of the nervous
system.

" Our consciousness makes plain to us that we not only feel, but
that we have very different kinds of feelings. Apart from ordinary
common sensation, apart from feeling as to temperature and from
visceral feelings, and feelings due to muscular action and the

6

cHaP. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 305 —

exertion of effort, there are those special activities we know as
sight, smell, hearing, and taste, the sPECIAL SENSEs, each absolutely
peculiar and incapable of merging the one into the other. Finally,
our consciousness shows us that accompanying these various states
of activity, there may be either one or other of two accompanying
conditions which we call respectively PLEASURE and PAIN.

Certain phenomena which excite the activity of nervous tissue are
called stIMULI.

These stimuli may be mechanical (as tickling, scratching, pinching,
cutting, &e.), or thermal (the application of heat or cold, producing
a feeling of thermal change), or chemical (the application of various
irritants), or electrical (causing a variation in electrical currents),*
or finally, stimuli, natural to nervous tissue, and originating in end
organs. These natural stimuli may be of two kinds; they may be
either (1) special (those which affect the organs of special sense, as
light, sound, &c.); or (2) psychical, t.e., the presence of certain
sensations, emotions, or cognitions.

The presence of any of these stimuli must be of course without
effect, unless the nerves acted on by them be in a certain state of
excitability or impressionability—or, as it is sometimes termed,
neurility. The long-continued excitation of a nerve will blunt, and
ultimately will for a time destroy its power of action. A too pro-
longed repose also diminishes and ultimately destroys its impression-
ability, and may at last lead to its transformation into adipose
tissue—a change which may also ensue if a nerve be separated from
its nervous centre while yet remaining within the body.

We have seen that nervous tissue 1s of two kinds, fibres and cells,
and the activity of the tissue seems also to be of two kinds, namely,
conduction (or an activity which conducts influences along nerves),
and a more positive kind of activity, comparable with the explosion
of a mass of gunpowder, to which a train of the same material has
conducted a potent influence. It is the fibres which serve as the
agents of conduction, and the cells of the grey matter are commonly
supposed to produce the more positive kind of activity by some.
special powers of receptivity and reaction which they possess. A
familiar example of this conduction and suddenly-active result is the
application of a heated substance to the skin, with the result of its
sudden withdrawal from such substance through the conduction of
some influence inwards from the skin to the source of the motor
energy of the muscles, which then produce such recoil. Nerve
action is altogether invisible. There is no, as yet observed, visible
indication of the active state of a nerve analogous to the shorten-
ing of a muscle which indicates myological activity. Re

What is the natTuRE of this NERVOUS activity (apart from its
results of motion or feeling, or secretion), is a matter of pure
speculation. I. It has been compared with the action of electricity,

* The resistance of nerves to electrical | versely as in the direction of their
conduction is five times as great trans- ! length.
x

oa
mine
ae | -

306 THE CAT. * [oHAP, Tx,

of which it has been deemed a special form. IT. It has been, and
is by many, supposed to be merely one form of physical foree—a
mode of motion—specially transformed by the molecular structure of
the matter through which it passes. III. It has been, and is by
many, deemed to be a special kind of vital force peculiar to nerve
substance.

As to the first hypothesis, the slow rate at which the nerve
impulse travels is alone sufficient to refute it. Whereas light

travels at the rate of 40,000 miles in a second, and electricity, along- -

a wire, at the rate of 462,000,000 feet per second—nervous influence
appears to pass but at a rate varying from 80 to a little above
200 feet in a second. Again, the interposition of a piece of wire
between the cut ends of a bisected nerve does not serve to convey
the nervous influences, and cold diminishes, instead of increasing,
nervous activity. Moreover, bruising a nerve impedes its action ;
but no similar effect could be produced on a wire serving for the
conveyance of electricity. Moreover, the intensity of nervous action
increases according to the length of the nerve it traverses, which is
no property of electrical conduction.

As to the second supposition—that nervous activity is merely one
condition of physical foree—it is but one form of the error which
would explain all vital action as physical, in spite of the manifest
impossibility of explaining generation, to say nothing of sensation in
any such way. But one special hypothesis of the kind is that
which views nervous conduction as the serial change of hypothetical
nervous molecules from one physical condition to another, nerves
being supposed to be made up of parts capable of being easily made
to pass to and fro from one physical state to another—as a series of
bricks set on end, may be alternately erected and thrown down, the
falling of one inducing the fall of its neighbour, and thus carrying
on serially an impulse initiated at one end of the series. If such a
conception is of any utility, as a working hypothesis to elucidate
nervous physiology, there can be no objection to its use, but it must
not be supposed to afford any real explanation.

As to the third supposition—that nervous activity is a peculiar
vital foree—it is again no real explanation, though it is perhaps the
most appropriate expression of the facts. It is manifest that the
living body is capable of varied activities, and that its several parts
exercise functions of different kinds. It is then little more than a
truism to say that nervous tissue is the seat of nervous force. It is
unquestionable that its integrity and stimulation are the conditions
sine qué non for the manifestation of all the highest animal activities,
while different degrees and kinds of injury inflicted on it result in
different degrees and kinds of impairment of such activities, and,
when carried beyond a certain point, end in the destruction of all
vital activities whatever—even of the merely vegetative or organic
activities. Nervous activity then is the vital activity of a living
organism as it energizes in its nervous system. But the conception
of a particular kind of vital force must stand or fall with the con-

r he
et a ee en

cHAP. 1x.) NERVOUS SYSTEM AND ORGANS OF SENSE. 307 ~

ception of Force itself, of which so much has been made by popular
teachers of our day. Force, indeed, has been, and is, constantly
spoken of as if it were a substance ; as if indeed it were the only
substance. But to plain minds, as well as to followers of the highest
philosophy—that of Aristotle—that which exists, as manifested to
our senses, is the external world of visible, audible, tangible, sapid
or odorous substances, which substances indeed possess many active
powers. Force is in reality but an abstraction; it does not exist
either for our senses or our reason apart from substances, and is the
nameapplied to the activities of such substances considered abstractedly
from the acting substances themselves. A living body is a special
substantial whole made up of parts, and both the whole and its parts
have various active powers, and the active powers of animals,
energizing through the nervous system are really what is meant by
the abstract term “nervous vital force.”

§ 29. We may now pass to the consideration of the functions of
the different parts of the nervous system. Before doing so, however,
it should be observed that certain conDITIONS are NECESSARY for the
continued exercise of all nervous activity.

Thus the temperature of the body must be moderate, certainly not
- less than about 72°, or more than about 120°. The nervous tissue
must also be adequately supplied with blood. This blood must be
sufficiently oxygenated, and also devoid of poisonous matter, such, ¢.g.,
as that with which it becomes charged from a cessation of the renal
secretion. Finally, the continuity of the more important nervous
structures must be maintained.

§ 30. The FUNCTIONS OF THE SPINAL NERVES are manifestly
both sensory and motor, according to their distributions and con-
nexions. If one of these nerves be divided and the cut end of its
distal part be irritated, motion ensues in the muscles to which such
nerve is distributed, but no pain ensues from such irritation. If, on
the other hand, the cut end of its proximal part be irritated, pain is
caused, but not motion. If the posterior root of a spinal nerve be
alone severed, the parts supplied with twigs from such nerve only
lose their sensibility, but their power of motion remains. If, on the
other hand, the anterior root of a spinal nerve be alone divided, then
the parts supplied by such nerve are paralyzed as to motion, but
nevertheless retain their sensibility.

It has therefore been concluded that all the nerves conveying
influence inwards, and centrally (called afferent nerves, and giving
rise to sensation), pass through the posterior roots of the spimal
nerves exclusively, and that the fibres which convey motor
influence outwards and peripherally (called efferent nerves), pass
through the anterior roots of the spinal nerves exclusively—the two
sets being mingled at and beyond the point of junction between the
roots, but sensory and motor fibres being distributed in the ramifica-
tions of each spinal nerve. It has been further assumed that the
nerves themselves neither feel nor initiate motion, but that both
feelings and motor impulses arise in the grey matter of the nervous

: x 2

308 . THE CAT. [cHar, Ix,
centres, with which the internal ends of the efferent and afferent
fibres —internal end organs—are connected. |

This opinion has been reinforced by the fact that after severe
injuries to the spinal cord, parts supplied with nerves which take
origin below such injury, become deprived both of sensibility and of
the power of voluntary motion, while irritation of the cut surface of
the proximal part of a divided nerve in a limb stump may produce
a sensation, which feels as if it took place in parts which no longer
exist—as, e.g., in the toes, when the leg has been amputated. But
in fact these phenomena are susceptible of another explanation, and
one which admits the belief that sensation occurs there where it
appears to occur—and not far away in the central part of the
nervous system. For as the completion of the electrical or magnetic
circuit is necessary for electric or magnetic discharge, so a certain
integrity of the nervous structure 1s necessary for the result of
nervous action in motion or sensation, even though such sensation
really take place at that part of the body where it seems to be felt.
When, however, the integrity of the nervous structures is impaired,
the motor or sensitive nervous activity is correspondingly impaired,
and the occurrence of non-natural and abnormal sensations might
be @ priori expected to arise under such non-naturaP and ab-
normal structural conditions. The occurrence of abnormal and
more or less delusive feelings after structural injury, by no means
proves that sensation is not peripheral under normal conditions. It
only proves that while nervous integrity 1s a sine gud non of normal.
sensation, it is not a condition for the occurrence of all: sensation,
but admits of the occurrence of feelings of an abnormal and
accidentally delusive character.

It has also been very often assumed and supposed that the dis-
tinctions between the functions of nerves (¢.e., whether they are
sensitive or motor) is due to some special endowment of the nerves
themselves, and not merely to the connexions which they may
happen to have. Now, however, it seems more probable that most,
if not all, nerves are essentially similar as regards their own intrinsic
powers, but that differeat nerves have practically different functions,
because their connexions are different. According to this view, any
nerve going from a nervous centre to a gland must have for its
function the promotion of secretion; any nerve going from a centre
to a muscle must have for its function the production of motion,
and any nerve going from a peripheral end organ to a centre must
have for its function either the promotion of sensation or reflex
action.

Whether this view be or be not correct, nerves, as we actually
find them, are either centripetal or centrifugal in their action, and,
as a rule, nervous influence can only be propagated in one direction
in any particular nerve. It may be that some nerves are inhibiting
ones, 7.¢., they are nerves which proceed from centres to the vicinity
of other nerves, and, by their influence, check or neutralize the
actions of the latter.

te ad f
ree ae eee ye

cHap. Ix.}] NERVOUS SYSTEM AND ORGANS OF SENSE. 309

§ 31. The so called runcrions of particular nerves are then partly
learned through their distribution, partly through experiments, and
partly by the very simplest observations. Those of the cRANIAL
NERVES, for instance>, which minister to special sense, are plainly
and obviously distinguishable from all others. Mechanical
stimulation of the optic or auditory nerves does not produce pain,
but only certain sensations either of light or noise. Division cf
the various cranial nerves causes paralysis or insensibility, or both,
to the parts they supply, in accordance with their distribution and
what has already been said as to their several functions.

Thus, division of the seventh nerve causes distortion of the mouth
from paralysis of the muscles of the face, except those supplied by
the fifth nerve.

The integrity of the pneumogastric nerve is needed for the experi-
ence of the sensations of oppression from want of air, of irritation in
the air passages, of hunger, thirst, &c., as also for the due performance
of the functions of the parts supplied by it. Thus its division paralyses
the movements of the stomach (so that food is only digested at its
surface,) and diminishes its secreting power, as well as that of the
liver, and renders deglutition impossible—finally even producing
suffocation. Yet it accelerates the action cf the heart, which is, on
the contrary, impeded or stopped by irritation of the pneumogastric,
so that it seems that this nerve acts normally as a check on the
heart’s action. Division of the spinal accessory nerves paralyses
the action of swallowing and also of the laryngeal apparatus and so
destroys the voice, though the respiration action (bemg under the
influence of the pneumogastric) continues. Division of the hypo-
glossal nerves, of course, paralyses the tongue. A short summary
of the functions of all the cranial nerves has been already * given.

§ 382. The FUNCTION OF THE SPINAL CORD is commonly considered
to be merely a conductor of both sensitive influence to the brain and
of motor (especially of voluntary) influence from it; and this is no
doubt true in a certain sense. Thus it is true that the transmission
of some influence up it to the brain is a necessary condition to the
experience of sensation, and that the transmission of some influ-
ence down it from the brain is a necessary antecedent to voluntary
motion; but it does not by any means follow, as is often supposed,
that on this account sensation and voluntary action are to be
considered as really localized in the brain because of the necessity
of the intervention of that organ in order to their experience.
Though, no doubt, what are practically the centres for complicated
motions, are in the brain.

With this proviso, we may treat, in the ordinary way, of the paths
which these influences seem to follow in traversing the spinal cord.
It is almost certain that both are predominantly situated in the white
fibres. It appears from recent experiments that both motor and
sensory impulses ascend and descend through the Juteral columns, the
special functions of the anterior and posterior columns being unknown.

* See ante, § 16, p. 275.

3l0 THE ' CAT.

If the spinal cord be cut through, it is impossible for the injured
animal either to feel any irritation whick may be applied to parts
the nerves of which take origin below the division, or by any
voluntary effort to move any such parts. Nevertheless movements

of such parts may be produced by stimuli applied to them, without

the occurrence of either conscious sensation or voluntary effort.
Such unconscious movement in response to unrecognized stimuli is
called REFLEX Action. This shows that the cord itself must be a
centre capable of initiating responsive action—of turning, as it were,
unfelt sensitive impulse into involuntary motor impulse. It does,
in fact, that which the brain does; but does it, at least when thus
mutilated, without the accompaniment of any perceived sensation.
This kind of action is also called automatic or excito-motor, and it 1s a
curious fact that responsive movements of this kind are more
energetic than they would normally be, owing possibly to the spinal
centres being entirely devoted to the reflex action, and not at all by
the transmission of influence to the brain.

But reflex action may take placein the uninjured condition, as during

sleep or under the influence of chloroform. Even when awake the

sudden and involuntary withdrawal of the foot from an irritating
object is an instance of essentially the same kind of action, though
since sensation here intervenes, such an action is spoken of as
sensori-motor, and is not exclusively due to the action of the spinal
cord. But, in fact, all action is “ reflex ”’ in the widest sense of that
term, 7.e., including sensori-motor action. For all animal actions
which do not result from unfelt stimuli (internal or external) result
from felt stimuli.

SEnsATIONs are capable of RADIATION or TRANSFERENCE, aS where
disease in the hip may produce pain in the knee-joint, or as, during
neuralgia, when pain proceeds from the part supplied by one branch
of a nerve to parts supplied by other of its branches.

§ 38. As to the runctrions of the MEDULLA OBLONGATA, it appears
to transmit and transfer influences in essentially the same way as
the spinal cord does—as when irritation of the stomach produces
headache, or when pain in one tooth results in pain in the corre-
sponding tooth of the other side. The sensory impulses proceed
through the restiform bodies (which are extremely sensitive to touch)
and the motvr ones, through the anterior pyramids. The division
of either pyramid resuits in motor paralysis, but, owing to the
decussation of their fibres, a paralysis of the side of the body opposste
to that of the division, supposing the cut to be made above the place
of decussation. Similarly, paralysis of the opposite side of the body
follows from destruction of one half of the encephalon above such
decussation. The function of the olivary bodies 1s unknown.

The medulla is the seat of many reflew actions, such, @.9., as

sneezing, coughing, closing the eyelids, swallowing, and the respira-_

tory actions. After the insensibility produced from concussion of
the brain or from chloroform, food placed far back in the mouth will
be swallowed and respiration will be still carried on. Indeed, in

‘rh ee

at $5 g Fina re
(cHap. Ix.

ve

cmap. 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 311

the frog, respiration will continue if the medulla be left intact, even
though the brain and the spinal cord have both been removed, while
destruction of the medulla oblongata immediately arrests it. Injury
to a limited region of the floor of the fourth ventricle causes sudden
cessation of respiration and instant death in warm-blooded animals.
The fact thatso many cranial nerves have their deep origins in thispart
of the cerebro-spinal axis, sufficiently explains the extensive character
of its excito-motor and sensori-motor activities. Indeed this part
may be supposed to serve as the organ of the common sense, i.e., of
that sense by which the several senses come into relation one w ‘ith
another and are felt as diverse modifications of one sentient being.

§ 34. The Functions of the Pons VAROLII are, at least, in part
similar to the conducting functions of the medulla—the central erey
and white portions-of both bemg continuous. Animals deprived of
both cerebrum and cerebellum, but with the medulla and pons
intact, remain motionless if undisturbed, but if disturbed move
themselves into postures of stable equilibrium, which they seem
incapable of doig if the pons be removed, although the medulla
be left.

If the fibres passing from the pons to the cerebellum on one side
be cut through, the injured animal’s body begins to rotate towards
the injured side, the eyeball of the mjured side moving downwards,
while the eye of the opposite side rolls convulsively.

The Funcrions of the CORPORA QUADRIGEMINA are closely con-
nected with the sense of sight, since not only their destruction causes
blindness and immobility in the iris, but they often waste after
atrophy of the eyes. ‘The destruction of one side of this structure
causes blindness in the opposite eye.

The optic THALAMI are also thought to be concerned in sight, yet
this sense may persist after their destruction. They are by many
supposed to form the anterior termination of the sensory tract of the
cerebro-spinal axis and to be the organ of the common sense, which
sense, however, may perhaps be more fitly attributed to the medulla
oblongata. There is evidence that they have to do with the power
of supporting the body on the limbs, as this power may remain after
the destruction of the corpora striata, but ceases after the removal
of the optic thalami.

The CORPORA STRIATA are similarly deemed by many to form the
anterior termination of the motor tract of the cerebro-spinal axis
and to convey downwards from the cerebrum impulses resulting from
the grouping of images attributed to the cerebral hemispheres.

The cEREBELLUM has had a variety of FuNcTions assigned to it,
but its real office is still unascertained. It has been supposed to
co-ordinate the muscular movements, or to specially direct the
muscles of the eyes, or to be the organ of space relations generally,
or finally, to be the seat of the sexual emotion.

On the whole it appears probable that the cerebellum ministers to
complex and co-ordinated muscular movements. Such a conclusion
seems to result from pathological facts and vivisections: animals

312 : ve THE CAT.

being unable to nse after they have been thrown down if the cere-
bellum has been removed. The greatest caution however is needed
m concluding from negative facts, and, as yet, it cannot be safely
affirmed what is the true and special function of this remarkable
organ, the predominant connexions of which are with the spinal
cord and not with the brain.

§ 35. The true FuNcrions of the CEREBRUM are also far from
being satisfactorily known. It has been generally regarded as the
organ of cognition, and it is abundantly proved that the destruction
of both the cerebral hemispheres puts an end to all manifestations
of intelligence, so that this view may be to a certain extent accepted.
Recent experiments also tend to make the opinion probable,
that certain of its surface regions are related to the five special
senses. But similar experiments have also shown that the electrical
stimulation of different parts of the cerebrum will cause different
movements. Such movements, however, may after all be due in
fact to the necessarily induced irritation of more deeply seated
parts by the unavoidable diffusion of currents. It seems, however,
to be fully proved that the cerebrum has a great deal to do with

motion, and is an important motor centre. It may be that by its -

sensory and motor connexions it ministers to that sense of effort,
and to those feelings of different kinds and degrees of effort which
are often spoken of (perhaps unfortunately) as the ‘‘ muscular
sense,” and to feelings of movement. For the present, however,
the true functions of the cerebrum cannot be said to be known,
although they afford abundant matter for more or less ingenious
speculation.

§ 36. The Funcrions of the syMPATHETIC sysTEM relate to the

performance of the organic functions of the body, and especially
regulate the activities of the viscera. .
On account however of the multifold and intimate connexions
of this system with the cerebro-spinal system, it has been as yet
impossible certainly to determine what activities are truly under
the control of the sympathetic. Normally its actions do not give
rise to sensation, though in unhealthy conditions pain may accom-
pany them. The presence of ganglia and afferent and efferent
fibres renders it in the highest degree probable that some sympa-
thetic nervous action is of the reflex order,—complete in itself and
more or less independent of the cerebro-spinal system. The action
of the sympathetic, by stimulating the secretion of glands, may call
into play instinctive actions and stimulate emotions. Both secretion
and nutrition are greatly influenced by the sympathetic, but this may
be, but indirectly, owing to alteration of the calibre of the arteries by
the influence of the vaso-motor nerves. Such of the arteries as are
supplied from any particular branch of the sympathetic become
dilated when that particular branch is cut. It is supposed that the
action of the vaso-motor nerves (derived partly from the sympathetic,
partly from the cerebro-spinal system,) is to keep the muscular coats
of the arteries moderately contracted, and that, therefore, when the

4
:
|

__—scwap, 1x.] NERVOUS SYSTEM AND ORGANS OF SENSE. 313

action of these nerves is paralysed (as, e.g., by division) the arteries
they supply dilate, and in this way increased sensibility and secreting
power is promoted by the greater supply of blood thus induced.
Some physiologists, however, explain this dilatation as a positive
instead of a negative action.

The nervous sytem is, as we have seen, Jilateral, but between the
two halves of its central part there are, as we have also seen,
numerous transverse commissural structures and decussating fibres.
The correspondence of function with structure in this respect is
shown by those cases, already given, in which injury or stimulation
of one side of the central nervous system produces effects on the
opposite side of the body. That the cerebral hemispheres. are each
capable of carrying on all the activities requisite for cognition is
proved by the fact that the destruction of one does not necessarily
even impair cognitive activity. It may seem strange that with the
presence of a double organ of such a special nature, processes of
cognition and feeling should be, as they are, single ; but, in fact,
there is no greater wonder in cognizing singly by two similar hemi-
spheres than in seeing singly through two similar eyes.

§ 37. A phenomenon that may not unfitly be here noticed, is
SLEEP, since during it the central nervous system, or part of it,
undergoes a temporary suspension of its activity. It is the cerebrum
and the sensory centres which thus periodically intermit their action.
Certain parts, however, of the nervous centres never sleep, as is the
ease with those which govern the unceasing respiratory actions, as
also those parts of it which minister to all the functions of vegetative
life. Yet, although thus continued, the frequency of the respiratory ~
and circulating movements, diminishes, and the temperature of the
body is consequently lowered. The quantity of the blood m the brain
is by some persons supposed to be diminished during sleep. Before
the daily period of repose is reached, the activity of the nervous
system has generally already been so taxed that it no longer
responds with thorough readiness to stimuli. With the assumption
of an attitude of rest, and with the closing of the eyes, this
torpidity increases, till it ends in more or less complete repose.
Sleep gradually counteracts the effects of previous activity, and in
consequence the readiness to respond to stimuli becomes progres-
sively greater as sleep continues, till the occurrence of some very
slight exciting cause suffices to awake the dormant animal. Apart,
however, from any exhaustion from fatigue, the cat generally falls
asleep with remarkable readiness at any hour (when not disturbed
by hunger or passion), as soon as it has become quiescent.

§ 38. Before concluding this account of the functions of the
nervous system by saying what remains to be said of the several
special senses, certain remarks may be made with respect to sENSA-
TION IN GENERAL.

Sensations are of two classes, external and interna’. The former
are produced by the agency of external bodies, the latter by the
body itself. They may both exist simultaneously, as when one part

314 | THE CAT. [oHAP. Ix,
of the body presses on another. For the experience of sensation at
all the presence of a nerve is a necessary condition, and for the
exercise of special sensations we require special conditions of special
nerves. Sensations are not momentary, but persist more or less as
after effects, as may readily be perceived by first looking at the sun
or any very bright object, and then looking at any duller object,
when a dark spot, or spectrum, will be visible, resembling in shape
the bright object previously looked at.

Frequent and continued repetition of the act of sensation diminishes
through exhaustion the sensitive power, but moderate, habitual
exercise of any faculty of sense tends to develope and perfect it.

The special sensitive faculties are each sw generis, nor can one
merge in another, nor all in any common power of sensation. Thus,
before any special sense can exist or act, if must be present poten-
tially, 7.e., 1t must be mnate. ach special sense is elicited in a
manner totally unknown. If we count up all the number of sensa-
tions which differ in-kind, their number will be seen to be consider-
able. Thus we have perception of change of temperature, the sense of
internal effort and resistance (the so-called muscular sense), the sense
of hunger, thirst, fatigue, sickness, and finally we have the two very
peculiar phenomena—pleasure and pain, and the faculties, touch,
taste, smell, sight and hearing, commonly called the special senses
par excellence. All the special sensitive faculties, however, may be
deemed to have a relation of similarity with touch, and in each, as
we have seen, delicate nervous filaments are exposed in some special
manner to receive a stimulation of a peculiar kind.

The feelings above enumerated are felt in different parts of the
body, nor are those persons who deny that they are really felt where
they seem to be felt, able to establish that they are actually felt in
any other place. 2

As to pleasure and pain, they are feelings of a special and un-
analyzable kind which accompany (either one or the other) in a
greater or lesser degree all other feelings. The healthy performance
of the bodily functions, when felt at all, is pleasurable. Hindrances
to, or irregularities in, their performance are commonly painful.
With many exceptions and variations, it may be said that pleasura-
ble sensations tend to guide to actions which are profitable to the
organism, and painful ones to deter from such as are injurious.

The sENSE OF ToucH in its simplest form is a feeling uf contact;
by intensifying this feeling we get feelings of resistance, density,
hardness, softness, &. By employing movement in addition, size,
distance and. figure become appreciated, and the nature of surfaces, as
e.g., their roughness, smoothness, &e.

The delicacy of touch, as perceived by the skin, varies much in
different parts, as we have seen. These differences are doubtless
related to the differences in the number of nerve fibres supplied to
the different parts.

Impressions received by touch become associated with other ones,
and cohere in more or less complex aggregations, which may be

omar. 1x] NERVOUS SYSTEM AND ORGANS OF SENSE. 315

retained in the sensitive memory, cohering and being retained the
more firmly, the more frequently they are repeated.

The sense of taste can only be exercised upon matters in a state of
solution. It is closely connected with the sense of smell, insomuch
that various flavours, which are commonly supposed to be perceived
through taste, become imperceptible if no use be made of the sense
of smell. Sight even has its effect upon taste, as the relish for various
pleasant tasting substances may be diminished by darkness. This sense
is very capable of education, and pleasurable feelings can be induced
by perseverance with respect to substances which are at first distaste-
ful. One kind of taste will for a time paralyze the power of
appreciation of other flavours, while, per contra, certain tastes (e..,
wine and cheese) reciprocally stimulate the intensity of gustatory
sensations they respectively give rise to. After-tastes are sometimes
observed, such as a taste of sweetness following the intensely bitter
taste of tannin.

The sense of smell needs for its exercise the presence of some
influence in the air drawn in through the nostrils, the Schneiderian
membrane being moist and the olfsctory nerves in a normal condi-
tion. Olfactory impressions do not persist as Jong as do those of
taste, and of course much less than those of touch, but they are very
‘delicate, a +5, oa's,c00 part of musk being perceptible when mixed with
common air. ‘The sense of smell can be strengthened by use, and it
tends to act both as a deterrent and also as a guide to what is
attractive to the organism. Odours become easily associated in
memory with sensations of other kinds, so that a recurrence of a
smell will often recall the latter. Smell may be considered as guard-
ing respiration, as so many noxious atmospheric conditions are
attended with disagreeable odours.

The sense of hearing gives information as to the intensity, quality,
and direction of sounds. It has been a widely received doctrine
that the nerve-branches supplied to the semi-circular canals enable
us to appreciate the direction of the sounds heard, while the cochlear
filaments serve to make known the qualities of sounds; these are
purely speculative opinions, and their truth cannot be relied on.

The sense of sight, as regards the mechanism of its organ, has
been already explained. It remains but to speak of the curious fact
that the co-existence of mverted images on the back of two eyes
produces but a single perception of an external world which is not
inverted. This phenomenon has been explained by attributing the
exercise of sight not to the eyes themselves, but to certain of the
grey masses within the cerebrum, or to the corpora quadrigemina.
It is, however, to say the least, no less inexplicable that such interior
grey masses should be the seat of sight, than that the retina itself
should be that seat. It is objected that irritation of the cut optic
nerve produces a sense of light, and it is thence argued that percep-
tion of light must be interior, as also that in persons who have lost
their eyes, diseased conditions may produce spectral illusions. But
__ to such objections it may be replied (analogously to the reply before

516— THE CAT
made as toa similar objection with respect to the spinal nerves), —
that we willingly admit the possibilrty that the excitation of a large
fragment of the organ of vision, may produce a fragmentary sensible
perception, as also that the grey matter of the interior roots of the
organ plays an important part in eliciting the act of sensation, but
these admissions do not render it any less rational to suppose that
when the whole organic circuit 1s normal and complete, the animal
really sees both in and with its eyes.* ,

As to the perception of distance and direction, it may well be that
the perceptions of all the special senses besides touch, ¢.e., colour,
sound, taste and smell, can only be localised, not by the nerves of
special sense, but by the help of those branches of the fifth nerve
—a nerve of ordinary sensation—which go to those organs.

The functions of the nervous system may then be summarized as
follows :— : |

It presides over, stimulates and regulates the alimentary, circu-
lating, respiratory, glandular and reproductive processes of the body;
it induces appropriate response to stimuli which are unfelt (reflex
action) and to felt stimuli (sensori-motor action); it regulates all
the muscular contractions which result in motion, and finally it
ministers to all those modifications of ‘‘feeling” and all those
complex associations and complications of feelings known as imagi-
nation, memory, emotion and cognition, to which reference will again
be made in the chapter on Psychology. |

* As the different end-organs of the | else each must be capable of stimula-
retina perceive different colours, either | tion by stimuli which are qualitatively
each such end-organ must be devoted | different. |
to the perception of one culour only, or

CHAPTER X.

THE DEVELOPMENT OF THE CAT.

-§ 1. By “the development of the cat” is signified the sum of those
rapidly succeeding morphological and physiological changes which
commence the life history of the animal. They are changes of great
importance and significance—changes in the very nature of the
creature undergoing them, as well as in the forms and relations of
the different parts of the body which successively come into existence.
Each individual of the species upon attaining majority, naturally
develops one or other of those two products which have been described
in the eighth chapter—ova and spermatozoa.

We may consider the formation of these products as the culmina-
tion of the individual’s development, and we may consider the
conjunction of those products as the initiation of another individual’s
life. The series of changes, then, which make up the cat’s life
history, is a series which tends (the requisite conditions being
supplied) to return in a cycle.. The impregnated ovum becomes, as
we shall see, an embryo; the embryo, a foetus; the foctus, a kitten;
and the kitten, a cat, destined to give rise to, or to fertilize, another
ovum like that with which this cycle of changes began. By the
cat’s ‘“‘development,” then, should be meant the entire sum of
changes it undergoes, from its cundition as an impregnated ovum
till maturity ; but practically it has come to mean (as above said)
that early part of the process which takes place up to, and till
shortly after, birth. Thenceforward the changes which ensue are
less changes in the forms and relations, than in the dimensions of
parts ; and the process of ‘‘ development” becomes mainly a proccss
of “ growth.”

_ § 2. But the ovum undergoes certain initial changes, even before
impregnation takes place, which changes may nevertheless be re-
garded as a part of the developmental process. Such changes, how-
ever, as well as some others (especially those of the earliest stages of
development after impregnation), have not been actually witnessed in
the cat's ovum. Nevertheless, the analogies of animals generally, on
the one hand, and of animals nearly allied to the cat on the other,
make it possible to infer what those changes in all probability are.
The ovum haying attained to the condition already described in

318 THE CAT. "as q

the eighth chapter,* with its yelk, zona pellucida, germinal vesicle
and spot, the first change preparatory to impregnation is the rupture
of the Graafian follicle. Having been cast forth from that follicle
and entered the Fallopian tube, the ovum spontaneously begins the
developmental process itself. Its nucleus, or germinal vesicle, ap-
proaches the surface of the ovum, and its outline becomes irregular or
obscure. Having reached the surface, one or two portions of its sub-
stance, called polar vesicles, are extruded through it from the ovum.
The remnant of the germinal vesicle then returns towards the centre
of the ovum, and constitutes the central, or so-called “ female” pro-
nucleus. It probably contains a nucleolus, and the protoplasm of the
ovum becomes radiately striated around it.

All is ready now for the act of impregnation.

§ 3. The spermatozoa having advanced to the ovum (for by their
vibratile action they can make their way up the uterine cornua and
Fallopian tubes), no sooner meet with it, than they plunge into
its outer transparent coat, and one spermatozoon (possibly,t but not
probably, more than one) actually bores its way through, and plunges
its lead into the substance of the ovum. That substance itself, how-
ever, is not altogether passive, for a small prominence may arise
from its surface to meet the incoming spermatozoon. Immediately
this contact has taken place, the outermost layer of the ovum’s pro-
toplasm may separate itself off as a distinct membrane, and so bar :
the way to the entrance of other spermatozoa. oe

The head of the spermatozoon having thus entered the ovum, it
constitutes there a second peripheral or “ male”’ pronucleus. This
advances towards the centre of the ovum, the protoplasm of which
assumes a radiate arrangement round it. Then the two pronuclei
are attracted towards each other and meet and fuse into a single
body called the ‘first segmentation nucleus (Fig. 141, A). This
nucleus has thus been formed by two corresponding parts from
the male and female organisms respectively. For the female
pronucleus is a portion of the nucleus of a germ cell, the whole
of which has become modified into the ovum, while the male
pronucleus is a spermatozoon, which is a part of the nucleus of
the original sperm-cell, which divided to form spermatozoa. We
have therefore in the first segmentation nucleus, what must rank
as a true nucleus of complex nature and diverse origin—an origin
from two equivalent and complementary parts.

§ 4. The next step in the process of development is that known as the
SEGMENTATION OF THE YELK, or vitellus, 7.¢., of the protoplasm of the
ovum. The first seementation nucleus gradually elongates, becomes
medianly constricted, and divides into two secondary segmentation

* See ante, p. 250. The reader will find a full statement and

+ There is as yet much divergence of | discussion of these -views in Mr. F.
opinion on this matter, and some ob- | Balfour's excellent Treatise on Com-
servers even maintain that the entrance | parative Embryology, vol. i., 1880,
of more than one spermatozoon is an | p. 67. :
occasion of monstrosity in the embryo.

CHAP. x.] THE DEVELOPMENT OF THE CAT: 319

nuclei, and the protoplasm of the ovum also divides, arranging itself
around each secondary segmentation nucleus. The two halves are
not quite equal in size. One, larger and more transparent (Fig.
141, B, e) is the ectodermic or epiblastic sphere, the other (7) is the
endodermic or hypoblastic sphere. Each sphere again subdivides,
and the same process 1s repeated with each subdivision, there being
thus four spheres, or cells, derived from the primitive epiblastic
sphere, and four from the primitive hypoblastic sphere. One of
these latter now assumes a central position (Fig. 141, C). The
process of division is then continued, but unequally, the cells derived
from the epiblastic sphere dividing more rapidly, and therefore be-
coming smaller than these from the hypoblastie sphere. Moreover

Fig. 141.—YELK°SEGMENTATION.

A. Impregnated ovum, with a single segmenta- B. Ovum, with the yelk divided into two
tion nucleus. cleavage cells, each with its nucleus.
h. External envelope. é. Epiblastic cleavage cell.
z. Zona pellucida, with spermatozoa. 1. Hypoblastic cleavage cell.
n. Segmentation nucleus. C. Fourth segmention into eight cells—four
y. Protoplasm or yelk of the ovum. epiblastic and four hypoblastic.

the epiblastic cells come to surround and enclose the hypoblastic
cells, save, perhaps, at one point where the hypoblastic cells may
appear at the surface (Fig. 142). The mass of cells, however, forms
a solid whole. There is no central cavity. Soon, however, a clear
space appears, and liquid forms between the mass of hypoblastic cells
and the epiblastic cells (Fig. 148, A), save at one part where the
two sets of cells adhere together. This process rapidly continues as
the ovum grows, the interspace becoming wider and wider, till at last
we have a relatively large sphere of very small epiblastic cells, against
the inside of one part of which the aggregation of small hypoblastic
cellsis flattened out, so that we have a double stratum of cells, consist-
ing of a single layer of hypoblastic cells beneath a single layer of epi-
blastic cells (Fig. 143, B). In other words, we have two cellular
membranes—an epiblast and a hypoblast—the epiblast investing
the whole ovum within the vitelline membrane, the hypoblast under-
lying only a portion, though a considerable portion, of the epiblast.
The cellular membrane thus investing the ovum, and derived from
the segmentation of the yelk, is called the blastoderm, and the

_ whole structure is the blastodermic vesicle. That part where the two

320 . THE CAT) | a

membranes coexist is the germ area, or gastrodisc. In the central
portion of this, a third membrane soon makes its appearance (Fig.
144). This is the mesoblast,
and is thought to be derived
from the hypoblast,* by sub-
divisions of the cells of the
letter. The three-layered part
of the gastrodise is a much
_ thickened part of it, and is
FA © FRA isa SM called the embryonal area, for it
Tee CE este ai is here that the embryo arises.
ge Nea NUT a Up to this point the matter
BOK incr SAM GON GLI -Coyeoy which is eventually to become
x ak OLR Ses the body of a cat shows no re-
“ ce gins semblance to any animal what-
ever. Itis but an aggregation
Fig. 142.--LonciTuDINAL SECTION THROUGH THE of cells of protoplasm arranged
AXIS OF THE OVUM, IN WHICH THE EPIBLASTIC : : :
CELLS (¢) HAVE ALMOST SURROUNDED THE aS just described, and is rather
Peper aeeroaue (). comparable with some very
5 Hypotasti¢ cell, occupying the interspace lowly organised fungus-lke plant
left at one point by the epiblastic cells. than with anything we ordi-
narily understand as an animal,

§ 5. It is in the midst of the embryonal area that the first sign

oli

ire a 8S
Y

of the cat which is to be, is made manifest by the FirsT APPEARANCE |

Fig. 143.
A. Commencing separation between the epi- B. Completion of the process, and formation of
blastic and hypoblastic cells. a germ area, or gastro-disc, of two layers—
e. Epiblast. one (e) of epiblastic cells, thé other (@) of
i. Hypoblast. hypoblastic cells.

k. Cavity formed by the separation.

OF THE EMBRYO. The first indication of the embryo is the appear-
ance of a longitudinal depression or furrow, termed the medullary
groove (Fig. 145), and it is the sign of the appearance of the most

important and central of all the organs of the future animal, for in

* In a paper read before the Royal | limitans hypoblastica. The fact of ‘its
Society on March 23, 1876, Mr. E. A. | presence favours the view according to
Schafer describes the formation of a | which the mesoblast is derived from the

membrane in the cat’s ovum between | epiblast. See Pro. Roy. Soc., vol xxiv., —

the epiblast and hypoblast. This mem- | plate 10,
branous follicle he named membrana

321

_ this groove is laid the foundation and commencement of the cerebro-
spinal axis, which, as we have seen, is the supreme and dominating
organ when that body has attained maturity, and which 1s thus formed
from inflected epiblast. The groove becomes enlarged at its anterior
end, in the situation of the future- brain (Fig. 145, C), while the
lateral margins of the whole groove grow up (as the dorsal plates or

Fig. 144.—Di1acGRAM oF SECTION THROUGH THE GERM AREA OF A MAMMAL aT RicuT ANGLES
TO THE SURFACE.

e. Epiblast. m. Mesoblast, or third layer.
i. Hypoblast. k. Cavity of the vesicle.

lamine dorsales) bend over and ultimately meet together above,
thus changing the groove into an elongated, hollow cylinder; the
central cavity of which is the precursor of the canalis centralis, of
_ the spinal cord, and of the third and fourth ventricles of the cerebro-

bu
wun jt vi
ee

DUTT

Yo oe

Fig. 145.—FirsT APPEARANCE OF THE EMBRYO, AS SHOWN BY THE MEDULLARY GROOVE.

In A the germinal area is pyriform, and the medullary plates on each side of it.
primitive groove occupies two-thirds of the In C the embryo is seen somewhat expa: ded
' harrow hinder end. towards each end.
; In B the groove 1s elongated, ana the sniddle at. Transparent area.
: line and line closely surrounding it indicates ao. Opaque area.
t the rising up of the lamin dorsales or mp. Medullary groove.
’

spinal axis as well as of the cter between them—the enlargement at
the cephalic end assuming the form of three successive dilatations or
vesicles. Beneath the longitudinal groove a cellular rod becomes
developed, extending forwards as far as the hinder end of the front
_ cephalic vesicle and backwards to the end of the medullary groove.
_ This rod is the norocHorD, or CHORDA DORSALIS, and occupies the
q place of the future bodies of the vertebrae, the soft substance of the

: intervertebral dises of the adult being its persistent remnant.
’ ¥

). ~~

NR Te Ney: TR SNe CG 60 Ot ae eee

322 THE OAT.

The notochord appears to be formed from the mesoblast, but it —
may be really of hypoblastic origin. While these changes are in
progress, a depression appears close to both
the cranial and caudal ends of the embryo—
the head and taz/ fol/s—and these extending
along each side of the embryo, the latter
comes to look somewhat like a small boat,
keel upwards, upon the surface of the ovum,
surrounded by the groove or depression
thus formed. The parts of this surrounding
groove between the head and tail folds are
called the /ateral folds. At the outer margin
of this depression the surface begins to grow
up all round the embryo as a prominent
circumvallation. Meanwhile the mesoblast
extends outwards and downwards on each
side of the embryo, so forming what are
called the ventral plates and lamine ventrales
(Fig. 147, A, Ww). As each ventral plate
descends it splits into two secondary Jaminz
Fig. 146.—Emervo morz av- (one external, the other internal) called re-

aCe Sey er oaRtyY spectively the soMATOPLEURE and SPLANCHNO-

BrasTopERM ATracHED. § pL ERURE (Fig. 147, B, so and sp). The distal
The medullary groove is not nart of the somatopleure, where it extends

yet closed over, but a

the head end it is par. beyond the embryo into the circumvallation
tially divided into the

three central vesicles; before mentioned, ascends with that cireum-
Piollereniiuenent, oie vallation around the groove about the embryo
primordial vertebre (pv) tg form the amnion, as explained below. ‘The
are to be seen on each

side. _ splanchnopleure adheres closely to the hypo-
“4 me corer cre eu? blest adjoming the yelk. That part of the
oo somatopleure which does not grow upwards,
comes ultimately to form the whole of the walls _

of the body and the limbs (Fig. 147, D). The splanchnopleure forms
the alimentary canal and structures adjacent to it. The cavity between
the somatopleure and splanchnopleure is the precursor of the future
peritoneal cavity (Fig. 147, D,»), and the innermost layer of the former
and the outermost layer of the latter form respectively the parietal and
the visceral layers of the peritoneum. Thus we have the body cavity
formed by a spontaneous longitudinal splitting of the mesoblast on each
side. ‘The further extension of the somatopleure gives rise to the
AMNION. It is formed thus: the somatopleure of the mesoblast, carry-
ing the epiblast with it, rises up on all sides of the embryo at the
outer margins of the groove round the embryo (around the head, tail,
and lateral folds in the circumyvallation before mentioned) and as each —
ascending part is double, an extension of the primitive peritoneal cavity
becomes thus continued upwards on all sides of the embryo. A chamber
is at the same time thus gradually formed between the outer surface
of the embryo and the innermost (more and more bent over) surface —
of this ascending, circumferential double layer, which thus gradually —

ONT el oR a ya
th a)

1p. x] THE DEVELOPMENT OF THE CAT. 323

‘a

_ grows up around and over the embryo. This up-growth continues
- until the ascending folds of the circumvallation meet and coalesce
above the embryo, and so form a completely closed sac above it.
This sac is the amnion (Fig. 148, 2, ® ,4). The cavity enclosed
by it is, of course, the same as the cavity of the “ chamber” above

INITIAL STAGES OF DEVELOPMENT.

Fig. 147.—Emeryo SEEN IN TRANSVERSE SECTION, SHOWING FORMATION OF SOMATOPLEURE AND
- SPLANCHNOPLEURE, AND OF THE PERITONEAL Cavity. THE PART OF THE SOMATO-
PLEURE WHICH ASCENDS BEYOND THE EMBRYO IS NOT REPRESENTED.

mg. Medullary groove. - . Peritoneal cavity.

e. Hpiblast. me. Mesentery.

m. Mesoblast. A. Embryo, with the mesoblast as yet unspl

h. Hypoblast. B. Mesoblast split into somatopleure and

ld. Lamine dorsales. splanchnopleure, and with an incipient

lw. Lamine veutrales. separation between the intestine and th

m. Notochord. subjacent umbilical vesical.

nc. Neural canal. : C. Further closing off of intestine from um-

sp. Splanchnopleure. bilical vesicle.

so. Somatopleure. D. The body cavity (or peritoneal cavity) com-

2. Intestine. pletely enclosed by somatopleure, while the

u. Umbilical vesicle. part of the splanchnopleure between th

ug. Prominences in which primitive urinary intestine and superior part of the embryo
and sexual glands arise. has become attenuated into a mesentery (m

mentioned as being “ gradually formed between the surface of the
embryo” and the ‘“‘more and more bent over surface” of the
ascending circumvallation. The embryo les in the amnion as in a
_ -water-bed. For though at first this sac is very small, it subse-
quently enlarges and becomes filled with a certain fluid called the
— liquor amnii. As the ascending folds are (as before said) double on
all sides (Fig. 148, *) it follows ‘that upon their coalescence a double
sac is at first formed. The amnion is the inner of these two sacs.
The sac external to it (formed of the outer layers of all the folds)
_ disappears by coalescing with the chorion, or outer envelope of the
_ ovum, within which of course all the changes here described take
_ place (Fig. 148, +), As the primitive peritoneal cavity was con-
_ tinuous with the space enclosed between the two layers of the
_ ascending folds, it follows that (upon the completion of the amnion)
_ there comes to be for a time a communication (over the back of the
_ embryo and above the amnion) between the two sides of the peri-
toneal cavity. This space is occupied by a more or less fluid or
gelatinous substance (Fig. 148, 57). This communication is, how-
_ ever, soon cut off by the descent and in growth of that part of the
* eee opleure which forms the side-walls of the body of the embryo.

Y2

T.

EB OAT,

Fig. 148.—Five D1aAGRAMMATIC VERTICAL SECTIONS THROVGH THE Lona Axis OF A MATURING
MAMMALIAN OVUM, TO SHOW THE FORMATION OF JTS EGG-MEMBRANES.

In Figs. 1—4 the section passes through the
middle of the embryo. In Fig. 5, it passes
a little on one side, so that the left side of
the embryo van be seen.

1. Ovum in which the chorion has begun to be
formed, with the blastoderm (and rudiment
of the embryo) within it. The whole germ-
vesicle consists of epiblast and hypoblast,
in the germ area, mesoblast (m) has also
appeared.

2. Ovum in which the head and tail-folds have
contracted the umbilical aperture towards
the yelk-sac; while the ascending circum-
vallation is seen rising at either end to form
the amnion. Here, then, the embryo is
beginning to separate from the germ-
vesicle (ds).

3. The amniotic folds being completed, have

met in the dorsal region; the umbilical
opening is more contracted, and the allan-

tois (al) has begun to sprout. Here we see |

the double sac forming above the embryo,
the inner part of which alone becomes the
amnion. The intestinal canal (dd) is begin-
ning to be distinctly formed.

4, Here the inner amniotic sac or true amnion
is detached from the outer or false amnion,

which has disappeared by coalescence with —

the inner surface of the chorion. The —
cavity of the amnion is more distended, and _
the yelk-sac (ds) has become smaller and —
pedunculated. The allantois (al) projects —
into the space between the amnion, chorion —
and yelk-sac; and the villi are larger, and —
have begun to ramify. ig

THE DEVELOPMENT OF THE CAT. 325

CHAP. X.]

Meantime, during the development of the amnion, another structure,
of great importance to the embryo, is being formed. ‘This is the
ALLANTOIS (Fig. 148, 3 & 4, al), which buds forth from the mesoblast
beneath the hinder portion of the incipient abdomen. It soon attains
a large size, and becomes supplied with blood-vessels for a purpose
to be presently described.

While the amnion and allantois are thus bemg formed, the side
walls of the embryo are closing in by the median junction ventrally
of the somatopleure of one side with that of the other side, and
the splanchnopleure of one side with that of the other side, thus
eS trees the inner layer of conjomed splanchnopleures—

a space which is the future alimentary canal (Fig. 147, C and D).
This is at first closed in front and behind, and everywhere, except
at one ventral point, where it remains open, and in connexion with
the remains of the yelk, which, with its envelopmg membrane, is
termed the umbilical vesicle (Fig. 147, C, a).

On each side of the medullary groove and notochord a series of
quadrate thickenings appear, termed protovertebre (Fig. 146, po),
which are the first signs not only of the vertebree, but also of the
muscles and nerves connected with them, to all of which they
give rise. Inflections of the epiblast about the incipient head, lay
the foundations of the organs of special sense, while an epiblastic
inflection at each end of the alimentary tube forms respectively the
buccal and anal chambers. In the mesoderm, immediately beneath
the anterior end of the chorda, the blood and blood-vessels become
developed, and one vessel, tubular and rythmically contractile, lays
the foundation of the heart. Blood-vessels at first go to and fro
between the umbilical vesicle and the heart to absorb nutriment
from the yelk, but subsequently these are outstripped in development,
and so replaced by other vessels which go to and fro between the
allantcis and the heart. Thus the great blood-vessels have at first a
very different course and arrangement from that which they ultimately
attain. About the alimentary canal, the liver arises, while the trachea

5. More advanced embryo, showing the proto- dg. Duct leading from the alimentary

vertebrz, visceral arches, and rudimentary
limbs. The allantois has grown out to the
inside of the chorion, and conveyed vessels
to it. The villi are more complex. The
umbilical vesicle is small, and connected
with the embryo by a long duct. In the
embryo cat, however, this vesicle is spindle-
shaped, and of considerable size, and the
duct is short.

e. Embryo.

a. Epiblast.

m. Mesoblast

t. Hypoblast.

am, Amnion.

ks. Head-fold.

ss. Tail-fold.

ah. Cavity of amnion.

as. Amnionic sheath of the umbilical

cord.

kh (Fig. 1). Hollow of the germ-vesicle,
which becomes (ds) that of the yelk-
sac.

canal to the yelk- sac,

df (Fig. 3). Lining of umbilical vesicle or
yelk-sac.

dd. Dorsal wall of intestine.

d. Yelk or vitelline OBERT or primi-
tive chorion.

ch. Permanent chorion, oath which not
only the onter layer of the amnionic
folds (sh), but also the allantois, has
combined.

al. Allantois.

7. Space, filled with fiuid, between the
amnion and chorion.

hh. Region of the heart and pericardial
cavity.

vl. en of the thorax in the region of the

art.
a’ (figs 1, 2, and 3); sz (Fig. 4) and
ch z (Fig. 5). Villi of chorion.
sh (Fig. 3). Outer layer of amniotic fold,
which, in Fig. 4, has coalesced with
the inner wall’ of the primitive
chorion.

. , } Ee cy. ian

326 PE Cat x

and lungs grow out from that canal ventrally. The renal and sexual —
organs arise close to the bifurcation of the ventral laminz into the
somatopleures and splanchnopleures, and the limbs bud forth asrounded
processes, the distal ends of which subsequently grow out into digits,
while the limbs themselves become flexed in reverse directions. On
each side of the body, close behind
the head, certain apertures ap-
pear, which lead from the exterior
to what becomes the pharynx.
These openings are the visceral
clefts, and their interspaces are
the visceral arches. Almost all
the clefts disappear before birth.
The formation of these various
organs will be detailed subse-
quently, but their relations to the
three primary layers, from which
the whole of them are built up,
Fig. 149.—SecTion THROUGH CorNU OF UTERUS, May be summarized as follows.

WING THE TWO POINTS OF ATTACHMENT : : 2
eS ZONARY RLAcENTA, THE EMBRYO The epiblast gives rise to the

BEING BEMOVED: epidermis of the skin, the ner-
pl. Placenta.
Tis” maternal portion sending processes vous centres, and the organs of

between. sense. The hypoblast forms the
. Tufts projecting from chorion or membrane, F P : i

enveloping embryo. epithelium of the alimentary
) a eal canal, except its two ends, and
ee yes otiie nrems . of the glands which open into

it. The mesoblast forms the in-
ternal skeleton, the muscles, connective tissue, peritoneum and
pleurz, and the vascular and secreting organs generally. It forms,
therefore, the great bulk of the cat’s body.

§ 6. During the whole process of development the germ is
nourished by absorption. Within the Graafian follicle it profits by
the cells of the discus proligerus and membrana granulosa, and when
cast forth from its follicle into the cavity of the uterus it absorbs —
nutriment from the secretions of the uterine walls by processes, or
villi, which grow forth on all sides from the surface of its chorion.
It also feeds upon the contents of the umbilical vesicle, absorbing _
nutriment thence by the help of the vessels which there circulate,
and which are at first of great relative size and importance. With
the development of the allantois, however, a new condition obtains.
That organ is destined to convey out embryonic blood-vessels to the
surface of the ovum, so that they may there be placed in intimate
relation with the blood-vessels of a special, corresponding maternal
structure, which is formed in the wall of the uterus around the
circumference of the therein-contained ovum. if: |

While the ovum is undergoing the incipient stages of develop- —
ment, corresponding changes take place in the maternal structures. —
The presence of the impregnated ovum within the uterus 1s ac- —
companied by the growth, on the inner surface of that organ, of a _

Py TOM VOR Sy (he TT OER SUPA IE AMEE Ce AR
Mi ce b Cm f

THE DEVELOPMENT OF THE CAT. 327

soft tissue called the decidua, within which the young ovum imbeds
itself, and from which it at first derives its nutriment.

As the ovum grows, however, one portion of the decidua thickens
and becomes highly vascular. This is called the decidua serotina
(Fig. 149, m), and it forms a ring round that part of the uterine
cornu in which the ovum hes. The adjacent part of the rapidly-
enlarging ovum also becomes specially suppled with blood-vessels
from the embryo contained within it, through the intervention of its
already-mentioned allantois. Processes from the vascular ring of
the chorion (Fig. 147, ¢) pass into recesses in the vascular ring of
the uterus—the serotina decidua, arid the two parts form an in-
separable interlacement called the PLacenta (Fig. 147, pl). The
maternal and embryonic’ blood-vessels, however, nowhere actually
communicate, and therefore no intermixture takes place between the
blood ef the embryo and the blood of the mother. An abundant
gaseous interchange, however, is effected between them, the blood
of the enbryo. taking oxygen from, and giving off carbonic acid gas
into, the maternal blood. Thus the placenta is a temporary and
indirect breathing organ for the embryo, which can breathe in no
other way, lying, as it does, enclosed in fluid.

As kas been already said, the allantois, with its blood-vessels—
called wmbihcal arteries and ceins—stretches itself forth into and
across the space within the ovum, till it arrives at the inner, surface
of the chorion, where it expands, wrapping round the whole embryo
with its amnion, carrying its vessels te the vascular portion of the
chorion, and so contributing to form the placenta. The junction
once effected, the arteries and veins connecting the foetus with this
part of the chorion rapidly enlarge. The umbilical arteries convey
the impure blood of the foetus to the placenta, where it is purified,
as before said, and nourished by the influence of the maternal
blood (the two fluids having but thin membrane between them),
and is then returned to the embryo by the umbilical veins, which
proceed back: along the allantois from the placenta. Meantime,
while the embryo is thus enclosed in its amnion and nourished by
its allantois, the splancknopleure grows im on all sides in the way
before mentioned, so as almost to separate the embryo from the
remnant of the yelk in its sac—the umbilical vesicle. The stalk
which connects this vesicle with the intestinal cavity of the embryo is

short but slender. It is called the citelline duct or ductus omphaio-

entericus. 'The umbilical vesicle remains of rather large size as a
transversely-elongated sac produced into two horn-like prolonga-
tions. It lies between the amnion and the allantois.

The structure which connects the embryo or fetus with the
placenta is called the umbilical cord. This is made up mainly of
_ the narrow part of the allantois (consisting of the embryonic or
foetal arteries and veins with connective tissue) with the vitelline
_ duet, the whole being bound round and enclosed by a fold of the
amnion extending down round it, and being thence reflected over
. the icetus (Fig. 147, cc). The umbilical cord is the sole channel

328 . THE CAT.

through which nourished and oxygenated blood is conveyed to the

foetus, and its importance continues till birth. The establishment of

pulmonary respiration, however, and the acquisition of the power of
taking nourishment by suction, do away with all need for the
placenta, and, by consequence, for its stalk, the umbilical ford,
which is gnawed across by the mother on the kitten’s birth. The

SE whe,
>
f

WO

WW
NS

\

| UA
He =o IS
—<$<—<——_ Ce
= '

Fig. 150.—Fa@tus IN UTERO (BUFFON AND DAUBENTON), SHOWING THE F@TUS ENVELOPED IN ITS
AMNION, AND WITH ITS ZONARY PLACENTA AND SPINDLE-SHAPED UMBILICAL VESICLE.

a. Chorion. h. The sae of the amnion

b. The zonary placenta. k. The foetus.

d. Umbilical vesicle. The short umbilical cord is shown passing from
tf, f. Its elongated extremities. | the abdomen of the embryo to the placenta,

g. The vitelline duct. and immediately giving forth its vessels,
forwards and backwards, into the placenta.

part left in connexion with the abdominal wall soon shrivels up,
dries, and falls off, but a permanent mark of its place of attachment
persists throughout life as the umbilicus or navel.

Such being the form and arrangement of the foetal membranes
and adjuncts, the embryo or rarvs itself gradually and in a round-
about way assumes the image of the kitten in the moll already

intimated, and which will be more fully explained in describing the ©

development of the several organs. 3 |

The period of gestation is fifty-five or fifty-six days. The ovum
having by that time attained its full inter-uterine development,
vigorous contractions of the muscular walls of the uterus ensue,
while the os uteri dilates. The embryo is thus expelled from the

[owAP. x.

.cuar.x] THE DEVELOPMENT OF THE CAT. 329

uterine cavity, and comes away, bringing with it a portion of the
‘maternal part of the placenta, together with the foetal part, with
which the maternal part is inextricably united. Thus the super-
ficial part of the decidua serotina comes away, while its deeper part
is left, with a torn and bleeding surface. Coincidently with the
termination of gestation, the mammary glands take on functional
activity and become ready to play their part in the post-natal
development of the young. After the expulsion of the embryos, of
which several are in general simultaneously developed, the uterus
forms a fresh internal lining, while the thickness of its walls
decreases by degeneration and absorption of a portion of its muscular
tissue, which had so much increased in quantity during pregnancy.

§ 7. It remains to consider seriatim, the development of the

various TISSUES and orGANS of the body.
_ All the various tissues and structures of the adult cat (connective
tissue, cartilage, bone—all parts of the skeleton of course included)
arise from the primitive fluid, granule, and cells of the fertilized
ovum by a process which is called differentiation. This term, which
is often used as if it were a real explanation, simply denotes the
fact that the various parts arise not through external actions, which
are but the concomitants and conditions of their origin, but by an
as yet utterly inexplicable and innate power possessed by the primi-
tive substance or matrix, within which the parts referred to, come
(under the requisite external conditions) gradually to manifest
themselves. Other terms relating to development similarly denote
spontaneous and mysterious actions of the formative power, and are
but convenient phrases for denoting the actions of such power, and
not expianations of it.

Such terms, for example, are segmentation—which denotes that a
structure, primitively of one piece, spontaneously divides its substance
into parts; vucuolation—denoting the spontaneous resolution of part of
a more or less dense structure in such a way as to give rise to a cavity
or cavities within it ; and fenestration—denoting that a solid structure
has dissolved itself at one spot or more, so as to give rise to an
aperture perforating it. When then the development of the tissues
and parts of the body are herein described, the intention is but to
state the order and mode in which they manifest themselves, the

fact being distinctly recognized that an innate force is the real and
efficient cause.

The primitive almost fluid substance containing granules, which
exists in the developing ovum, is known as protoplasm ; and proto- |
plasm is often spoken of as if it were a sort of primary organic material
—a distinct kind of formed substance—from which all organisms arise.
But the fact that the primitive substance of one animal or plant is
not to be distinguished by any chemical or physical test we can apply
from the primitive substance of another animal or plant, does not by
any means prove that the two are really the same substance. It does
not prove this identity, because of the very different results which

__ are successively evolved in the two cases, as development. proceeds.

330 THE CAT. [omamiane so
This ultimate diversity 1s amply sufficient to show that a real differ-
ence existed from the first—a difference thus demonstrable to our
reason, though not manifest to our senses.

From the primitive substance of which the cat’s ovum consists, all
the ultimate constituent parts of its body are derived through the
help of the ce// formations, already described as the epiblast, hypoblast,
and mesoblast. It has already been mentioned that the epiblast gives
rise to the epidermis of the skin and to the nervous centres; the
hypoblast, to the alimentary epithelium; and the mesoblast, to the great
mass of the body. But parts which are derived from one of these
sources may acquire characters quite like those derived from another.
Thus the linings of the two ends of the alimentary canal are (as has
been said) formed from inflected epiblast, and epithelial structures
(as in the lining of the vessels and of the peritoneal cavity) can be
formed as well from the mesoblast as from the epiblast.

All the tissues and organs of the cat’s body are then derived
from cells, and indeed they are doubly so derived, since the ovum
before yelk segmentation begins, is a perfect ce//—with its cell-wall
(or periplast) and its nucleus (or endoplast), the latter being fur-
nished with one or more nucleoli. Thus this cell begets the cells
of the three layers of the embryo, and these latter cells beget all the
tissues and organs which subsequently arise, and the great mass of
them are begotten by the cells of the mesoblast.

But though all the tissues have this ultimate cellular parentage,
they by no means always retain a plainly cellular structure, as they
severally arise from the primitive, or “indifferent,” tissue of the
mesoblast, and become definite connective, muscular or nervous
substance, as the case may be. Sometimes they take on the form
simply of a soft substance of one or another kind, within which
nuclei are embedded at intervals. From analogy we may regard
the parts of such substance which are adjacent to such nuclei as
representing cells, the limits of which are severally indistinguishable.

The five main constituents of the cat's body—(1) connective tissue,
with its derivatives, cartilage and bone; (2) epithelial tissueg (3)
blood; (4) muscular tissue; and (5) nervous tissue—arise as follows:

Connective tissue appears to arise in the embryo, partly as a jelly-
like substance, or matrix, and partly as cells from the mesoblast,
which though more or less separated by this substance, yet remain
connected by processes which grow out in a radiating manner from
them. The fibres of the tissue are by some observers described as
arising within the protoplasm of the cells, those of adjacent cells unit-
ing, while the parts of the cell not thus transformed persist as connec-
tive-tissue corpuscles. Other observers, however, believe that the fibres
arise, as an independent deposit, within the intercellular substance.

Elastic tissue is said to be tormed from other cells which grow out and
branch, becoming connected with processes from neighbouring cells.

Cartilage appears in its simplest condition (in the chorda dorsalis
or notochord) as a mass of closely applied, thin-walled cells. The
layer of the embryo from which these are derived, is (as has been

i
r
, ae eT
a Se

GHAP. X.: THE DEVELOPMENT OF THE CAT. 331 ~

said) not yet positively ascertained, but the other cartilages of the body
are undoubtedly of mesoblastic origin. The walls of the primitive
eartilage cells thicken and form the intercellular matrix, acquiring
at the same time the special qualities of cartilaginous tissue. The
thus-formed matrix may remain clear and structureless, or may
become fibrillated, as in the case of fibro-cartilage.

Bone is a substance which is never directly formed from the in-
different embryonic tissue, but requires for its development the
pre-existence of either cartilage or connective tissue. The process
of its formation in these substances has been already noticed.*

Epithelial tissue is the most distinctly and permanently cellular of
all the tissues of the body, and it arises directly from the-cells of
the epiblast and hypoblast, with the exception of the endothelium
of the vessels and pleuro-peritoneal cavity, and some other parts
which are derived (as already said) from the mesoblast. The epen-
dyma of the cerebral ventricles is the persistent epiblast of the lining
of the medullary groove of the embryo. Ova and spermatozoa may
be considered as special modifications of epithelial tissue.

Blood appears to originate within cells derived from the meso-
blast,¢ either by a multiplication of their nuclei and the acquisition
of a red colour by the protoplasm around each nucleus, or else as a
sort of deposit within the cells. However originating, the primitive
corpuscles when formed become separated from one another by a
process of vacuolation + within the cells. The cells then enlarge
and send out processes which unite with those of other cells. The
walls which separate the cavities of such united processes then dis-
appear, so that their cavities communicate, and thus blood and blood-
vessels are stmultaneously formed. 3

The primitive red corpuscles are nucleated, and larger than
those which subsequently arise, which latter, together with the
white corpuscles, seem to be formed mainly by the spleen, the
nucleated red corpuscles disappearing and being replaced by the
smaller, flattened non-nucleated corpuscles, during embryonic life.

Muscular tissue, though by no means clearly cellular in its fully
formed condition, is said to have a distinctly cellular origin, beg
formed by direct transformation of embryonic cells as follows : § the
cells elongate and acquire an investing membrane and often pointed
ends. The nuclei multiply, and the contained protoplasm of the cells
gradually acquires its striated character. The investing membrane
becomes the sarcolemma, and the scattered nuclei become the
corpuscles. The unstriped muscular fibres originate simply by the
lengthening out and flattening of cells, which acquire pointed ends
and an elongated nucleus.

Nervous tissue is, as has been said, mainly derived from the epi-

* See ante, p. 20.

+ A perfect agreement has not yet
been arrived at as regards their mode of
origin. See Balfour, Quarterly Journal
of Microscopic Science, July, 1873 and

Schifer’s Proceedings of the Royal
Society, 1874.

~ See ante, p. 329.

§ See Wilson Fox, Phil. Trans., 1866.

332 THE (OAT.

blast ; but. although the nervous centres are thus formed, and though
the cranial nerves arise also as small invaginations of epiblast, yet
the mass of nerves which permeate the body im all directions cannot
be so derived, but must originate from mesoblastic tissue. The
ganglionic cells or nerve corpuscles are doubtless derived from
embryonic cells, which became transformed in nature and send forth
processes (very generally) in the way described.*

As to the nerve-fibres, they seem to be formed by the coalescence

Fig. 151.—LoneiTupInaL SECTION OF AN EMBRYO, SHOWING THE INCIPIENT VERTEBRAL
COLUMN WITH ITS VERTEBRAL CENTRA AND SPINOUS PROCESSEs.

1. Cerebral hemispheres. | cl. The cloaca. ed
2. Vesicle of the third ventricle, v. The urinary bladder and pedicle of the allan-
3. Mid-brain. tois.
4, Cerebellum. u, wv. The umbilicus, or root of the umbilical
5. Medulla oblongata. cord, containing the duct from the intestine
ch. Notochord passing forwards through the to the yelk-sac, the pedicle of the allantois
bodies of the vertebree into the basis cranii, (or urachus), and the umbilical vessels.
and terminating in the head between the w, The Wolffian body, which appears as an
infundibulum and the pituitary body. elongated viscus, with many transverse lines
s. The spinous processes of the vertebre. situated above and between the two letters,
n. The spinal cord. 4 and i; whereof the left-hand 7 is placed
P. The pharynx. upon the stomach, and the right-hand 7 on
h. The heart. the large intestine close to the cecum and
t. The liver. entrance of the small intestine.

i. The stomach and intestine.

in lear series of spindle-shaped cells, and to be at first of the
nature of pale or grey fibres, but afterwards, in great part, to acquire
a medullary sheath and to become white fibres.
8. We may next consider the origin of the organs, and first the

internal skeleton. 3

The AXIAL SKELETON makes its appearance much earlier than
the appendicular skeleton, inasmuch as its foundations are laid in
the lamine dorsales bounding the medullary groove, and in the
notochord as already described. The distinction of the axial skeleton
into its vertebral and cranial portions is laid down from a very early
period, since the enlargement of the anterior end of the medullary
groove into the cerebral vesicles at once marks out the cranial part,
a distinction rendered yet plainer by the non-extension of the
chorda dorsalis forwards through it.

* See ante, p. 255.

cHAP. x.) THE DEVELOPMENT OF THE CAT. 333

The earliest indication of the segmented condition of the VERTEBRAL
SKELETON is the appearance of the quadrate masses of tissue, appear-
ing serially in pairs behind the head—the so-called proto-vertebre
(Fig. 146, pv), or dorsal segments, already noticed as arising in the
mesoblast on each side of the chorda dorsalis and medullary groove.
The front part of the first of these bodies corresponds in position with
the atlas, and each pair of dorsal segments gives rise, amongst other
structures, to part of the bony spe. The dorsal segments do not,
however, correspond with the future vertébre, but each segment
becomes transformed into: (1) the hinder part of one vertebra, (2)
the anterior part.of the vertebra next behind, (3) the roots of a
spinal nerve, and (4) the muscles and skin immediately connected
with the vertebral parts so formed. Thus each primordial vertebra
becomes ultimately segmented, while each successive pair of such
primordial vertebrae ultimately coalesce, and so a different segmenta-
tion is brought about from that which appears at first ; the points of
separation of the later segmentation, alternating with those of the
earlier segmentation. ‘The first dorsal segment of each side differs
from those which succeed, in that when it becomes segmented, its
anterior half has nothing in front wherewith to coalesce, and thus
the atlas must be formed from half a primordial vertebra instead
of being formed, like the other vertebre, from the hinder half of one
primordial vertebra and the anterior half of the primordial vertebra
next behind. 3

Moreover, while the upper part of each dorsal plate becomes a
segment of dorsal musclé, with its skin, the lower part undergoes a
different change in its anterior (cephalic) and posterior halves. An-
teriorly it gives rise to the root and ganglion of a spinal nerve.
Posteriorly it gives rise to the transverse process of a vertebra or
proximal portion of a rb.

The mner part of each dorsal plate bifureates as it extends
inwards. One branch ascends in the dorsal lamina till it meets its
fellow of the opposite side and so forms the foundation of the future
neural arch. The other branch advances inwards above and below
the chorda,’and blends with its fellow of the opposite side to form
the foundation of the central portion of a vertebral segment. Thus
each permanent vertebra is the offspring of the parts of two adjacent
primordial vertebree. Its neural arch, transverse processes, the
proximal part of its ribs, and the cephalic portion of its centrum,
are formed from the hinder end of one proto-vertebra, while the
rest of its centrum and its spinal nerves are formed from the anterior
(cephalic) end of the proto-vertebra next behind.

This condition having been, as it were, laid down in soft tissue,
transformations of parts of the structures thus formed, into cartilage,
soon begin.

Cartilage of the ordinary kind first invades the body of each
vertebra and surrounds the chorda, encroaching on and constricting
it at intervals, the chorda yet continuing a structure of large thin-
walled cells enclosed in a fibrous sheath. Cartilage becomes also

f.

334 THE CAT. Ph
deposited at intervals along each dorsal lamina; forming cartilaginous
neural arches which, however, do not for sometime fully unite together _
on the dorsal side of the myelon. Cartilages also extend down im
each ventral lamina as the cartilaginous predecessors of the ribs, and
those of the thorax, by their median fusion in the mid-ventral line,
lay the foundation of the sternum. \ :

The third stage of vertebral development, or the ossification of
the spinal column, begins to show itself as three (or four) ossific
centres arising in each of the vertebrae. ‘These centres are placed
one in each lateral part (at the junction of the transverse process
and neural arch), and the other, or third, in the centrum. This
last is sometimes double at first.

Besides these separate centres each vertebra, while immature, has
certain epiphyses or temporary separate terminal ossifications. Thus
the tip of each prominent process
(neural spines, transverse and
articular processes and the met-
apophyses) has its epiphysis,
and a thin lamina of bone is
developed as an epiphysis on both
the anterior and posterior sur-
face of each centrum. The atlas
ossifies from two lateral ossifica-
tions, and one median one ven-
trally placed.

In the axis, in addition to the
ordinary ossific centres found
in other vertebra, the odontoid
process ossifies from two centres,
placed side by side, which soon
unite. There is also an epiphy-
sis at the apex of the odontoid
process, and one between it and
the centrum of the axis as well

Fig. 152.—D1IAGRAM OF Fa@TUS, SHOWING
THE VISCERAL ARCHES AND BUDDING LIMBS.

(It represents mainly conditions existing
between the third and fourth weeks.)

. Prominence produced by incipient cerebrum.

-. Prominence produced by region of third
ventricle.

c. Prominence by region of corpora quadrige-

mina.

os

d. Prominence produced by ‘cerebellum.

e. Prominence produced by medulla.

al. Allantois.

h. Heart.

t. Liver.

au. Incipient ear.

oc. Incipient eye.

na. Incipient nose.

ns. Naso-frontal process.

mps. Maxillary process (from first visceral arch)
laying foundation of upper jaw.

1, 2, 3, 4. ‘* Visceral arches ;” between them are
the ‘‘ visceral clefts.”

as on the hinder surface of the
latter. Thus the odontoid pro-
cess ossifies as if it were, as in
fact it is, the true centrum of the
atlas vertebra.

The ribs are ossified each from
one centre, with an epiphysis for
the tuberculum and another for
the capitulum.

In the cervical vertebra more or fewer of the transverse processes

ossify, at least occasionally, from a distinct ossific. centre in their
ventral branch, a circumstance which tends to show (what is in fact
the case,) that these double (or perforated) transverse processes are
ribs with very short bodies. |

Similarly the sacral vertebrae have each a distinct ossific centre 1
each of their lateral masses.

}
)

"| i ie ee Ae ee eae SF ATES nf ag ‘ - oe
Te, Pee eee ey actrees keep ; Na.
* ie I? aie ? * ee ’ te ,
, * hs Wat ” 77 ne Tyan? es
aay a a), een ¥ , 7

p.x.) THE DEVELOPMENT OP THE CAT. 235

he manubrium ossifies after the other 7 a of the sternum,
which seem each to ossify from one centre.

§ 9. The DEVELOPMENT OF THE SKULL takes place in a specially
circuitous manner, so that its early stages are strikingly unlike its
mature condition. The first indication of the future skull is given
by the expansion, before mentioned, of the anterior end of the
medullary groove, which expansion, as has been said, becomes
divided by two lateral constrictions (one in front of the other, on
each side) so that three rounded vesicles are formed lying serially
one before the other. The notochord extends forwards to beneath
the second of these vesicles, wnich bend down sharply in front of
its anterior termination, so that there comes to be one vesicle
above, one in front of, and one below the anterior termination of

the chorda.

These vesicles are, as we shall hereafter see, the commencements

of the future brain.
In the walls of the ascending lamine dorsales, which bound
the vesicles laterally, there are no quadrate thickenings like those
_ developed on each side of the chorda in the ‘vertebral region,
while peculiar developments take place in their ventral lamine.
For while the medullary groove is being arched over and con-
verted into the great axial, neural canal, by the ascending laminz
dorsales, another axial canal is being formed beneath the neural
one by the descending lamina veutrales. This second axial canal
is the rudimentary alimentary one. The ventral lamine, as they
bend down to enclose the incipient pharynx, grow thinner and
thinner at successive intervals, one behind the other, till a series
of perforations, the visceral clefts, are formed, one after the other,
each cleft leading from the exterior imto the pharyngeal cavity.
Four such visceral clefts appear on each side. The perforation
proceeds from within outwards, the hypoblast being absorbed first,
then the inner part of the mesoblast, and finally, the whole of the
- mesoblast, the hypoblast growing outwards along each advancing
wall of each aperture, and ultimately becoming continuous with
the epiblast. In front of each cleft the wall of the ventral lamina
becomes more or less thickened, forming what are called the
visceral arches (Fig. 152, }, #, 3, 4)—each such lateral series of arches
being at first separate from their fellows of the opposite side, as
are the ventral lamine themselves. Meantime another pair of
vesicles—the cerebral vesicles—grow forwards (side by side) from
that which was at first the most anterior vesicle ; and a pit formed
beneath the outer anterior part of each cerebral vesicle lays the
foundation of the future nasal organs (Fig. 152, na), while two
other and more posterior invaginations on each side (one beneath
what was the first vesicle and the other beside the hindmost)
respectively lay the foundations of the eye and of the ear. The
mouth is formed by a superficial depression—as will be subsequently
more fully explained. On each side of the mouth the first visceral
_ arch has meantime grown down and united distally with its fellow of

lee i bed Alie gim So . ni oe

336

Fig. 153.—OUTLINE oF THE HEAD AND NECK OF AN SJMBRYO
PiG, TWO-THIRDS OF AN INCH IN LENGTH, SEEN LATERALLY

MAGNIFIED SEVEN DIAMETERS.

Fig. 154.-Tur SKULL OF THE SAME EmpBryo (IN ITS INCIPIENT
STAGE OF DEVELOPMENT), SEEN FROM BELOW.

TEN DIAMETERS (VENTRAL ASPECT).

THE CAT.

the opposite side toform
the lower jaw, while
a process grows for-
ward and upward from
the more proximal
part of each first
visceral arch, such
growth, termed the
maxillary process(Fig.
152, mps), laying the
foundation of the up-
per jaw. The two

not, however, join to-
gether m front, but
both join a median
down growth, termed
the naso-frontal process
(Fig. 152, ns). This
last-named process de-
scends from the front
end of the floor of
the incipient cranium,
and has on each side
of it one of the two
depressions which are
the incipient olfactory
sacs. Its lower end
forms the:middle of
the front of the upper
jaw, while the max-
ullary processes which
unite with its distal
end, on each side,form
the sides of the upper
jaw. The interval left
on each side (above
the junction of the
naso-frontal and max-
illary processes,) forms
the nasal passage, and,
in part, the lachrymal

MAGNIFIED

The following letters indicate the same parts in whichever of the above figures they occur, or in

both figures :—

cl to c®. The five divisions of the young brain.

a, The eye.

m. The nose.

m. The mouth.

tr. Cartilage of the trabeculz.

ctr. Cornua trabecularum.

pn. Pre-nasal cartilage.

ppg. Pterygo-palatine cartilage.

mn. The mandibular arch, with Meckel’s carti-
lage.

.te First visceral cleft, which becomes the tym-
pano-Eustachian passage.

au. The auditory vesicle.

hy. The cerato-hyoid arch.

br (1 to 4). The branchial:bars and clefts.

thh. The thyro-hyoid.

py. The pituitary fossa.

ch. The notochord in the cranial basis, sur-
rounded by the investing mass (iv).

VII. Facial nerve.

IX. Glosso-pharyngeal.

X. Pneumogastrie.

XII. Hypo-glossal.

Tomar, x,

maxillary processes do

.

5

a _———

cnap. x.] THE DEVELOPMENT OF. THE CAT. 337

eanal. The first visceral cleft persists on each side as the external
auditory meatus, the tympanum and Eustachian tube. The other
visceral clefts all successively close up and disappear. The primitive
roof of the mouth is formed by the floor of the cranial cavity;
subsequently a lateral growth from each maxillary process extends in-
wards so as to form a partition across the upper part of the primitive
buccal cavity, thus constituting the palate, and separating the hinder

arts of the nasal passages from the mouth. The posterior nares
open at first (before this growth of the palate) into quite the anterior
part of the primitive buccal cavity.

The cartilaginous basis of the true future cranium is laid at
the anterior end of the chorda dorsalis, which becomes surrounded
by a solid, flattened mass of cartilage called the bas?-cranial plate or
parachordal cartilage, which is the precursor of the basilar part of
the occipital bone.

Continuous with this on each side is a rounded portion of cartilage,
which encloses the primitive ear (formed by a depression of the
surface, as before mentioned) and is the precursor of the petrous
part of the temporal bone (Fig. 154, aw). The basi-cranial cartilage
grows up on each side, and these lateral parts meet together above
and enclose the foramen magnum with a cartilaginous ring. The
basi-cranial plate, together with the enclosed chorda, stops short
anteriorly at the hinder margin of what later becomes the sella
turcica.

From the front of the basi-cranial plate two cartilaginous rods,
ealled the trabecule cranii (Figs. 153 and 154, tr), extend forwards.

_ They at first diverge, but afterwards converge and meet, thus

enclosing between them the place of the future pituitary fossa

_ (Fig. 154, py). The trabecule at their anterior junction form a

cartilaginous expansion called the ethmo-vomerine plate, which sends
downwards three other plates to form the median and _ lateral
ethmoids (thus embracing the two primitive olfactory sacs,) in-
growths of the lateral ethmoids forming the future maxillo-turbinals.
Also two small cartilages appear, on each side of the cranial cavity,
as forerunners of the ali- and orbito-sphenoids.

The walls and roof of the skull are otherwise completed by
membrane only, until the commencement of that membrane’s
ossification.

There are certain other cartilages, however, which play an
important part in forming certain parts of the bony skull, namely,
the cartilages of the visceral arches.

The first of these descending rods of cartilage, is connected above
with the cartilaginous auditory capsule, and is called ‘“ Meckel’s
cartilage” (Figs. 153 and 154, mn). What has the appearance of
being merely an outgrowth forwards from this first descending rod

(the maxillary process of the first visceral arch) lays the cartilaginous

foundation of the bony upper jaw, including the pterygoid and

palatine bones (pps), while the rest of Meckel’s cartilage (beyond the

point where such process is given off forwards) lays the cartilaginous
Z

\

338 THE CAT.

oundation for the lower jaw, and ends by uniting with its fellow of
the opposite side. |

The next, or second cartilaginous rod (hy), connected above, like
the first, with the auditory capsule, descends in the second visceral
arch, and lays the foundation of the anterior cornu and body of the
os hyoides.

The cartilage of the next visceral arch (Fig. 154, th) is the pre-
eursor of the posterior cornu of the os hyoides. No noticeable
permanent part of the skeleton is formed in the fourth visceral arch.

§ 10. The process of osstFicaTion of the skull begins with the
mandible, where one centre of ossification appears in each lateral.
moiety at an earlier period than in any other part of the skeleton.
It is an ossification in the membrane investing Meckel’s cartilage,
and not in the cartilage itself. |

Immediately after the mandibular ossification, follows that of the
maxille and premaxille.

The premaxille are ossifications in the cartilage of the naso-
frontal process, while the maxille are ossifications in the membrane
investing the maxillary processes. The palatine and pterygoid
bones arise as ossifications in the cartilage of the maxillary
process.

Fresh points of ossification also indicate the swpra-occipital, the
parietals and interparietals, the frontals, the squamosals, the vomer,
the nasals, the lachrymals, and the matars, all these bones being
ossified directly from membrane, and not through pre-existing
cartilage; but cartilaginous ossifications also indicate the future
basi- and ex-occipitals, the ali-sphenoids, the basi-sphenoids, and the
orbito-sphenoids, with the pre-sphenoid, as also the palatines and
pterygoids, as above mentioned. Other ossifications arise successively —
and at various intervals. Thus, the median ethmoid and cribriform
plate ossify late, as also do the bones of the os hyoides. The vomer
1s an ossification of the membrane investing laterally the lowest part
of the ethmo-vomerine cartilage.

The occipital bone for a time exists in four distinct pieces, the
basi-, ex-- and supra-occipitals.

The frontal bones remain divided from one another by a con-
tinuation forwards of the sagittal suture.

The sphenoid bone consists at an early period of eight distinct
and significant parts: the bulk of the body, or basi-sphenoid; the
front part of the body, or pre-sphenoid; the greater wings, or ali-
sphenoids; the lesser wings, or orbito-sphenoids; and the true
pterygoid bones. ;

The temporal bone arises from many distinct centres, and consists
for a time of several distinct bones. Amongst these bones are the
squamosal (including the squamous part and zygomatic process), the
_ tympanic parts, and the tympano-hyal. The bone which forms
the inner and larger chamber of the tympanic cavity does not
appear till a fortnight after birth. It sends in a process to form the
septum, as does also the outer tympanic bone, so that the septum in

CHAP. X.] THE DEVELOPMENT OF THE CAT. 339
the adult really consists of two layers of bone which have anchy-
losed together.

Besides these four elements, three other distinct ossifications arise
in the primitive cartilaginous auditory capsule, spread and coalesce
to form the petrous and mastoid portions of the temporal bone.
They are distinguished by their various relations to different parts
of the bony and membranous labyrinths. The first of these 1s called
the pro-otic, and forms the upper rim of the fenestra ovalis, and
invests the anterior vertical semicircular canal. It ultimately forms
that part of the petrous bone visible inside the skull and part of the
mastoid. The second ossification is the beginning of the opisthotie.
It forms the lower rim of the fenestra ovalis, and entirely surrounds
the fenestra rotunda. It constitutes the lower part of the petrous
bone. The third ossification results in a bone called the epiotie,
which invests the posterior vertical semicircular canal. It ultimately
forms the mastoid process.

The auditory ossicles are formed, in part at least, by ossifications
of the proximal ends of the cartilages of the first and second visceral
arches. |

That of the first arch, or Meckel’s cartilage, long persists on the
iner side of the mandibular ramus, but its upper end ossifies as the
processus gracilis and body of the malleus. The proximal end of
the second arch, which. appears at one period to be bifurcated, has
as ossifications of one of its upper ends, the tympano and stylo-hyals,
while the other end becomes the body and long crus of the incus,
the latter being its apex and summit.

The stapes is of a different nature, beimg a small part of the
eranial wall which has grown out, become separated, and secondarily
connected with the upper part of the second arch.

The lower end of this arch cssifies as the epi-, cerato- and basi-hyals.

The os orbiculare is the uppermost end of that part, the lower
portion of which is the thyro-hyal.

The thyro-hyals are the solitary ossifications of the third viscera
arch.

Thus, in recapitulation, the skull as a WHOLE may be said to arise
as follows :—the cranial walls and floor behind, are formed from the
parachordal and auditory capsular cartilages ; in front, by the trabe-
cule, the ethmovomerine plate, ale and orbital cartilages; above,
from membrane. The visceral arches form the jaws and hyoid, in
conjunction with downgrowths from the ethmoyomerine plate. The
trabecule extend forwards between the floor of the brain cavity and
the roof of the pharynx, closely embracing the pituitary fossa, ito
which the roof of the primitive buccal cavity temporarily (see below,
p- 343) projects.

§ 11. The timss of the embryo begin as two slight prominences on
the surface of each lamina ventralis. ‘They subsequently take the
form of somewhat cylindrical processes, each with a flattened terminal
expansion (Fig. 152). This expansion becomes divided at its distal

end into five processes (the digits), the pre-axial one of which in
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340 THE CAT.

each limb diverges from the others to a certain extent. The hallux,
however, does not continue to develope. At first each limb is so_

laced that its dorsal surface is outwards, and thus the concavities
of both the elbow and knee are directed inwards. As development .
proceeds, the two limbs are both rotated, but in opposite directions.’
The fore-limb becomes so rotated that the extensor surface is turned
backwards, while the pelvic limb is rotated so that the correspond-
ing surface is turned forwards. Thus, the elbow and knee come to
be bent in opposite directions. The pelvic limb requires no further
torsion, since the foot is now ready to assume the posture needful
for locomotion. The bent arm, however, would have the back of
the fore-paw turned downwards if no farther change took place—a
posture manifestly inconsistent with the animal’s mode of walking,
which requires the palmar surface to be applied to the ground.
This difficulty is obviated by a further torsion, but one which is
confined to the forearm and paw. This further torsion consists in a
change from the primitive condition of supination into that before
described as pronation. With the exception of the clavicle, all the
bones of the fore-limb are preformed in cartilage.

In the scapula the coracoid process shows a separate centre of
ossification, and two such appear in the acromion process. The
supra-spinous part of the scapula ossifies as a separate plate of bone,
and is quite distinct from the rest at birth.

The humerus arises from one main ossification in the shaft, and
two terminal epiphyses. The proximal epiphysis arises from three
centres, one in the head and one in each tuberosity. The distal
epiphysis arises from four centres, which respectively appear in the
two condyles, the capitellum and the trochlea. Both the radius and
the ulna ossify from one central ossification in the shaft, and two
terminal epiphyses.

_ Ossification of the carpus begins later than does that of the meta-
carpus and digits; only one centre of ossification 1s formed in each
carpal, except the scapho-lunar, which has two.

The first, or most pre-axial metacarpal (that of the pollex), has
its epiphysis at its proximal end. The epiphysis of the other meta-
carpals is placed at the distal end of each. All the phalanges.
without exception have their epiphyses at their distal ends (Fig. 60).

The ossification of the lower limb begins soon after that of the
upper, a bony nucleus appearing early in the shaft of the femur, and
also in that of the tibia. Apart from the patella, all the bones of
the pelvic limb ossify from cartilage.

The os innominatum arises from three centres—those of the ilium, —
ischium and pubis—with certain epiphyses, the principal of which
are one on the tuberosity of the ischium and another along the
crest of the ilum. }

The femur (Fig. 6) has one epiphysis for its head, one for each -
trochanter and one for its distal end.

The tibia and fibula have each one principal ossification—that of
the shaft—and two terminal epiphyses. In the tibia the superior

CHAP. X.] THE DEVELOPMENT OF THE CAT. 341

epiphysis is the first to appear and the last to unite. In the fibula
the superior epiphysis is both the last to appear and also to unite.

The tarsals each ossify from one centre, as do the carpals, except
the os calcis, which has also an epiphysis at the end of its tuberosity.

The metatarsals and phalunges of the hind-foot (or pes) ossify in
the same way as do the corresponding parts of the fore-foot (or
manus), except that the hallux remains in a very rudimentary con-
diticn. The bony parts of the hind-paw ossify at about the same
time as do those of the fore-paw.

§ 12. The muscixs of the trunk arise in what are called the
“‘muscle-plates ” of the primordial vertebrae, forming, as such plates
do, the upper part of each dorsal segment. Hence are derived the
erector spine mass of muscles, the segments of which primitively
correspond in number and position with the vertebrae: themselves.
The muscles of the abdominal wall are formed in the mesoblast of
the somatopleure. The sub-vertebral muscles, such as the longus
colli, &c., are formed in the mesoblast, which lies nearer the centre
than the division between the somatopleure and splanehnopleure
ever extends. The muscles of the limbs do not arise as protrusions
of the body muscles outwards. They are directly formed in
the mesoblast of the budding members themselves.

§ 13. The aLimenTaRY CANAL is formed, as has been already
intimated, by the splanchnopleure and hypoblast. It is at first in
the form of an axially directed groove placed beneath the notochord,
and opens downwards towards the yelk—and therefore is turned in
the opposite direction to the medullary groove above it. The walls
of the groove are, on each side and in front and behind, formed by
mesoblast, everywhere lined by the hypoblast. This groove soon
changes (by the descent and convergence of the splanchnopleure on
both sides of it) into a canal. At each end (7.e., at the head and
' tail end) of this canal, the descending ventral lamine (which are there
undifferentiated into somatopleure and splanchnopleure), close it in;
so that, as has been already said, the incipient alimentary canal at
first ends blindly both in front and behind, though in its middle it
remains open, communicating with the yelk or vitelline sac by .
means of the vitelline duct. When the communication is almost
closed up, the vitelline sac takes the name of the umbilical vesicle,
and on it ramify certain blood-vessels, which are, for a time, of
great importance.

The incipient alimentary canal 1s straight, cylindrical and attached
to the underside of the vertebral column by a wide but thin layer of
mesoblast. After a time the tube, towards the middle of the body,
bends down away from the vertebral column, pulling out, as it were,
the interposed layer of mesoblast into a thin vertically extended
membrane, the future mesentery. Part of the tube on the anterior
(cephalic) side of this loop or curve, dilates more and more and
becomes the stomach ; the part on the posterior side of the loop be-
comes the transverse colon. To the most promiment and middle part
of the loop itself, the pedicle of the umbilical vesicle is attached. In

ERE Pes, ake A ely

349 THE CAT. Tonaaete
subsequent development, the part of the loop pre-axial to this point
of attachment, increases in length vastly more than does the part
post-axial to it. The part in front (pre-axial) becomes the duode-
num, jejunum, and the greater part of the ileum. The part behind

\

Fig. 155.—LONGITUDINAL VERTICAL SECTION THROUGH AN EMBRYO, SHOWING THE INCIPIENT
INTESTINE WITH THE RELATIONS TO IT OF THE LUNGS AND LIVER.

d. Intestine. c. Yelk-sac.

o. Mouth. m. Duct leading from the intestine to the yelk-
a. Anus. sac.

l. Lungs. wu. Allantois.

h. Liver. r. Stalk of allantois.

g. Mesentery. m. Amnion.

v. Auricle of heart. w. Cavity of amnion.

k. Ventricle of heart. s. Outer layer of primitive amniotic fold, which
b. Arterial arches. is separating off to coalesce with the inside
t. Aorta. of the primitive chorion.

(post-axial to) the attachment of the umbilical vesicle, becomes the
rest of the ileum and the colon. Thus that proximity of the transverse
colon to the stomach and‘duodenum which we have seen in the
adult condition, is initiated at first; the long intervening tract
being formed by the outgrowth and coiling of the primitive loop, the
distal ends of which (stomach and transverse colon) preserve very
nearly their primitive relations. The distinction between the large
and small intestine is first indicated by a small prominence, the
future cecum, which appears a little post-axial to the attachment of
the vitelline duct of the umbilical vesicle. The large intestine is, at
first, of less capacity than the small.

The formation of what are ultimately the two ends of the
alimentary canal, namely the mouth and anus, has already been
incidentally referred to. The primitive pre-axial end of the alimen-
tary canal reaches beneath the skull, where it ends blindly below
the pituitary space and forms the cesophagus and pharynx.

The anterior end of the canal is at first closed by the lamina
ventralis, which descends in front of it as a single plate, not divided
into an outer somatopleure and an inner splanchnopleure. In the

healt " a¥elalts

cmap. x] THE DEVELOPMENT OF THE CAT. 343

external surface of the pre-axial end of the embryo, the mouth
appears as a depression on the surface of the front end of the head.
This depression is bounded above by the naso-frontal process and
below by the first visceral arch, and the tongue arises in the floor of
the chamber thus formed. This primitive buccal cavity extends
back beneath the cerebral vesicles till it meets the blind end of the
front of the pharynx, into which it soon opens by a process of
absorption of the intervening partition formed by the just mentioned
lamina ventralis, part of which partition persists as the velum
palati. An upgrowth from the buccal cavity, the pituitary body,
meets a downgrowth (between the trabeculee) of the braim—the
infundibulum. It is thus these parts are formed. Afterwards the
pituitary body becomes cut off from the buccal cavity and adheres
to the infundibulum.

The anus is formed in an analogous manner at the post-axial
end of the embryo. Here at first the intestinal groove is continuous
with the medullary groove round the hind end of the chorda
dorsalis, but the ventral lamina descends behind, as a single plate
not divided into an outer somatopleure and an inner splanchnopleure,
and closes in the hinder end ot the alimentary tube. The hinder-
most part of this primitive tube is called the clouca. Beneath the
posterior end of the chorda a depression of the epiblast appears;
this deepens, and the mesoblast of the ventral lamina is absorbed,
a perforation being effected and the rectum and anus thus formed. It
is from the ventral wall of the cloaca that the allantoic sac before
described grows out, but it grows out beyond the poimt where the
ventral lamina begins to be differentiated into somatopleure and
splanchnopleure. It grows out therefore from the latter into the
interspace dividing those lamellar subdivisions of the mesoblast.

The teeth are developed each by a double process. In the place
for each tooth that is to be, a depression takes place in the mucous
membrane of the gum, the deepest layer of the epithelium thicken-
ing and extending into such depression. The sac of epithelium
thus formed widens atits deepest part, while simultancousiy a papilla
of the mucous membrane rises up from below and pushes itself into
the deep surface of the widened part of such epithelial sac. The
mucous papilla ultimately becomes the mass of the future tooth,
while the deepest surface of the epithelial inflection (into which the
ascending papilla has protruded) becomes the enamel of the tooth,
on which account it is called the “ enamel organ.” Thus each tooth
arises from two distinct sources. In the process described, the neck
of the epithelial depression becomes exceedingly attenuated, while
what is called a ‘‘dental sac” forms itself about the developing tooth
by direct transformation’ of the mucous membrane, into an outer
layer of fibrous tissue with a vascular layer within. The contained
papilla then assumes the shape of the crown of the future tooth,
and soon begins to calcify, thin caps of dentine being formed on
the milk teeth within the gum, at an early period during gestation,
each cap thickening by degrees as it extends its margins. As soon

Fe: +. ee

344 THE OAT [omar x,
as the crown of the tooth is completed its base becomes constricted,
and then, as it grows, the papilla becomes narrower and so the fang
is formed, its soft substance becoming smaller and smaller through
the progress of calcification around it, till nothing but a minute

central pulp cavity 1s left, through which the vessels and nerves —

pass. If the tooth be a molar, a separate cap of dentine is formed
at first for each cusp, while when the crown has been formed, the
development of the papilla becomes modified by the cessation of its
erowth in certain parts (with corresponding ingrowths from the
alveolus), so that it becomes subdivided into as many parts as the
tooth is to have roots. The soft tissue left is the foundation of the
future roots, the pulp of the tooth now adhering only by them
instead of by one undivided soft body, as is the case where there is
to be but one root. }

From the epithelial sac of each growing first (or mk) tooth, a
little diverticulum is given off, contamimg a continuation of the
primitively inflected epithelium, and against this, another small
papilla rises and imbeds itself, and thus the foundation of each
second or permanent tooth is laid. The relations of the milk and
permanent teeth have been already given in the second chapter.

As the teeth are formed, so also are the bony walls of the alveoli
which grow up and come to surround and embrace them.

The formation of the dentine of the teeth takes place by
gradual transformation of the surface of the dental papilla (consist-
ing of round nucleated cells in a clear matrix) in such a way as to
leave the dental tubuli cpen, as already described. ,

The enamel is formed by more complete transformation mto
mineral substance of the epithelial enamel organ, while the cement
is formed by the ossification of the connective tissue immediately
surrounding the dental papilla, and leaving not only tubuli, but as
we have already seen, corpuscles similar in form and nature to the
corpuscles of true osseous tissue.

The LIVER arises as two diverticula given off from each side of
the alimentary canal, immediately behind the stomach (Fig. 155, h),
each diverticulum consisting of both mesoblast and hypoblast. The
former thickens greatly, and becomes very vascular, while canals
from the two primitive diverticula extend and ramify within the
cylinders of anastomosing cells which it builds up. The growth of
this organ is extremely rapid. At first the liver is almost quite
symmetrical in form, its right and left lobes being nearly equal.
The gall-bladder arises as a special diverticulum of both hypoblast
and mesoblast. |

The PANCREAS appears as a bud from the left side of the duo-
denum, where both hypoblast and mesoblast are thickened; canals
lined with the former ultimately being developed within the latter.

The sALIVARY GLANDS arise in a similar manner at the anterior
end of the elementary tube. They differ from the pancreas, however,
inasmuch as their cavities are lined with epiblast, since this it 1s
which forms the lining of the buccal inyagination.

—

,
“> 5) oe

omar.x.] THE DEVELOPMENT OF THE CAT. 345

‘The PERITONEUM, so complicated in the adult, arises as simply. the
lining membrane of the adjacent surfaces of the two diverging plates
(somatopleure and splanchnopleure), into which each ventral lamina
splits. Therefore, for a time, the primitive peritoneal cavities of the
two sides are continuous with each other, not on the ventral side of
the embryo only, but, as before pointed out, over its back, between
those doubled folds of somatopleure which ascend on all sides to form
the amnion (Fig. 148, 7°).

As the somatopleures descend and gradually embrace the ali-
mentary canal—formed by the splanchnopleures—they enclose
more and more the peritoneal cavity, and when they come to meet
together below, they do so completely (Fig. 147, C, D).

It has already been seen that the divergence of the middle part
of the alimentary tube from the vertebral column produces an in-
cipient mesentery. By a continuation of this process the alimentary
canal comes to be slung, from the skeletal axis, in a mesenteric
peritoneal fold. With the increasing complexity of contortion into
which the alimentary canal is thrown by its great increase in length,
a corresponding increase of complexity is induced in the mesenteric
folds by which it is slung. A pouch of it, having of course four
walls, becomes protruded ventrally between the stomach and trans-
verse colon, and so forms the omentum.

§ 14. The sioop makes its first appearance in the interior of the
primitive BLOOD-VESSELS, as already described. Both blood and
blood-vessels begin to appear first in that layer of the blastoderm
which is immediately adjacent to the embryo.

Certain of the primitive mesoblastic cells of the embryo become
masses of corpuscles in fluid, enveloped by more solid nucleated pro-
toplasm—the primitive walls of the vessels. These arise, as before
explained,* from the junction of radiating processes of adjacent cells,
the cavities of which open one into another. Blood-vessels are at
first confined in the embryo’s body to the splanchnopleure.

The HEART arises as an elongated cavity in the splanchnopleure
of the anterior end of the embryo. It consists at first merely of
nucleated cells, and its rythmical contractions begin while im this
incipient, merely éellular condition, and before the muscular fibres,
which subsequently arise, are developed. Its first form is that of
an elongated vesicle, or tube, into the posterior end of which two
veins open, while a large artery proceeds from its front end. It
increases in size and thickness, and bends over in a crescentic loop,
projecting downwards and towards the right. At the same time two
shght constrictions divide it more or less into three successive
portions. The hindermost of these (that into which the two veins
open) becomes the future auricles. The next portion becomes the
ventricles, while the most anterior segment, from which the great
artery proceeds, is called the budbus arteriosus. As the heart be-
comes more and more bent, the auricular portion approaches the

+ 2. Bok,

346 | THE CAT. a

ventricular portion, which latter comes to lie transversely. Mean-
time a septum grows up, dividing the ventricular part into a right
and a left chamber. The septum extends on into the bulbus, which
becomes divided into two channels, those of the aorta and of the
pulmonary artery respectively. As soon as the ventricular septum
is complete, another septum begins to divide the auricular portion
into a right and left chamber, but this septum remains incomplete
even at birth, when an aperture, the foramen ovale, stillremains, and
allows the blood to pass directly from the right to the left auricle
without passing through the lungs. It is the existence of this
perforation in the new-born kitten * which renders the drowning o
it. so long a process. !

The more important ARTERIES arise as follows. The aortic bulb
gives off at first two arteries which run forwards till they reach the first
visceral arch, inside which they pass upwards to beneath the spine,
where they unite together to form the incipient dorsal aorta. As
the length between the most anterior part of these primitive aortic
arches and the heart, lengthens (from the growth of the embryo),
other arches successively arise from the forwardly extending bulb,
and ascend to the backwardly extending root of the dorsal aorta,
forming, as it were, a succession of short cuts on each side to the
dorsal aorta (Fig. 156,134). Four vessels thus arise on each
side behind the first, and respectively ascend inside successive visceral
arches to the aorta. There are thus five such ascending arches

developed on each side, though only three exist at the same time,

the earlier and more anterior disappearing as the later ones arise.

Ultimately the fourth arch of the left side persists, grows, and
becomes the arch of the adult aorta. That of the right side becomes
the innominate and right subclavian and carotid arteries. The more
anteriorly situated arches become transformed into branches of the
earotids. The fifth arch disappears on the right side altogether, but
that of the left becomes the pulmonary artery, a communication
between it and the great aorta persisting till a little after birth as
the ductus arteriosus (Fig. 157, da), a relic of which is seen in the
fibrous cord which connects together these arteries in the adult.

The descending aorta at first gives off on each side a large omphalo-
meseraic artery (Fig. 156, oma), which goes to the vitelline sac, or
umbilical vesicle ; but these branches dwindle as the aorta comes to
give origin to two other considerable and more posteriorly situated
arteries (ua) called wmbilical (the future hypogastric ones), which
proceed into the allantois and placenta. From each umbilical
artery a comparatively small branch (J/a), the future diac artery, 1s
given off, and goes to the incipient pelvic limb.

In the process of their DEVELOPMENT the more notable VEINS
undergo remarkable changes. The first important veins to appear
are two which pass upwards from the umbilical vesicle to the heart,
and are called the mght and left omphalo-meseraic veins (Fig. 156,

* T have found this foramen still open a week after birth.

‘omar. x.) THE DEVELOPMENT OF THE CAT. 347

omv), and which, as it were, lay the foundation of the future portal
and hepatic veins. Before entering the incipient auricular end of the
primitive heart, these omphalo-meseraic veins first unite nto a common
trunk and then dilate into a venous chamber, which bears the name
of sinus venosus (Fig. 156, S), and opens directly into the heart.

lig. 156.—D1acraM oF Fatal, ARTERIES AND
VEINS. VERY EARLY CONDITION. THE
ARTERIES AND VEINS OF ONE SIDE ONLY
ARE REPRESENTED TO AVOID CONFUSION.

S. Sinus venosus.

A. Auricle.

V. Ventricle.

B. Bulbus arteriosus.

L. Liver.

1, 2, 3, 4. Aortic arches.

a. Dorsal aorta.

oma. Omphalo-meseraie artery to umbilic>
vesicle.

ua. Umbilical artery (to allantois).

ila. Mliae artery to incipient hind-limb.

ca. Caudal artery.

omv. Omphalo-meseraic vein.

uv. Umbilical vein.

dv. Ductus venosus.

hv. Hepatic vein.

ilv. Iliac vein.

vci. Inferior vena cava.

pc. Posterior cardinal vein.

ac. Anterior cardinal vein.

de. Ductus Cuvieri.

Fig. 157.—D1aGRAM OF THE Fra. CIRCULA-
TION THROUGH THE HEART AND AORTA.
CONDITION OF HEART AND GREAT VESSELS
AT BIRTH.

RA. Right auricle.

LA. Left auricle.

RV. Right ventricle.

LV. Lett ventricle.

A’. Great aorta.

A*. Second aortic arch (afterwards pulmonary
artery).

pa, pa. Incipient branches to lungs

da. Ductus arteriosus, which at first places the
two aortie arches in direct communication.
The arrows indicate the course of the blood,
one going directly from the right to the
left auricle through the foramen ovale of
the as yet incomplete inter-auricular
septum.

Soon two elongated venous trunks make their appearance beneath, and
parallel to, the primitive vertebral column (ac and pc), each such
vein sending down a branch, called a ductus Cuvieri (dc), to the
sinus venosus. That part of each of these two trunks which runs
backwards from the head end of the embryo to its ductus Cuvieri,
is called an anterior cardinal vein. That part of each of these
trunks which runs forwards from the hinder part of the embryo to
the ductus Cuvieri of such trunk is called a posterior cardinal vein,
which ultimately become the azygos vein. Before the commence-

Ce ee ee ee tee ee eee ee eee pea Arc

348 | THE CAT. [cHAP. x.
ment of the placental circulation, the only important veins besides
the cardinal ones are the omphalo-meseraic veins; but with the
beginning of the placental circulation two veins, called the right and
left umbilical veins (uv), come from the placenta, pass up the allantois
and join the omphalo-meseraic veins at their entrance into the
liver. The right omphalo-meseraic vein and the right umbilical
vein soon disappear altogether. The left omphalo-meseraic vein
sinks by degrees into comparative insignificance, but is joined by
the now more important mesenteric veins. Of the vessel thus formed,
that part which is on the heart side of the liver, ultimately becomes
the vessel connecting the hepatic veins with the heart. The left
(now the only) umbilical vein, joined by veins from the anterior
abdominal walls and other parts, unites with what was the common
omphalo-meseraic trunk, now become the portal vein, and also
sends out branches (portal veins) into the growing liver, while much
of the blood it brings is conveyed on by an undivided vein, called
the ductus venosus (Fig. 156, dv), directly to the sinus venosus.
Meantime other veins—the hepatic veins (hv) —form in the substance
of the liver and open close beside the opening of the ductus venosus
into the sinus venosus. Thus what was originally the combined
trunks of the omphalo-meseraic and umbilical veins persists till birth
as the ductus venosus, while diversely directed branchmg veins
(forming two systems, the portal and the hepatic), are developed in
connection with it—the portal system of veins diverging into the
liver from near the proximal end of the ductus venosus, while the
hepatic veins converge towards the vicinity of the distal end of the
ductus venosus.

Meanwhile, concomitantly with the incipient development of the
pelvie limbs, there arises the great system of the vena cara mferior
(ect). This is formed by the junction of the veins of the legs and
pelvic viscera (the incipient external and internal ilac veins) into a
median trunk, which receives accessions from the kidneys (renal
veins), and runs on beneath the great dorsal aorta to the heart,
where, intruding upon the junction of the hepatic veins and sinus
venosus, it ultimately absorbs, as it were, the latter chamber alto-
gether, and thus the hepatic veins come in the adult to open into the
vena cava inferior. .

During this period, the right ductus Cuvieri becomes attached to
the developing right auricular part of the heart, and while the
anterior cardinal veins become large and important, as the jugular
and subclavian veins, the posterior cardinal veins become relatively —
reduced into the right and left vena azygos. Then a transverse
communicating branch, which connects the two jugular veins,
rapidly enlarges, while the left ductus Cuvieri diminishes and dis-
appears. This transverse branch becomes the Jeff innominate
vein, and thus the right ductus Cuvieri (having now the right
jugular and subclavian veins brought into connexion with it) be-
comes transformed into the vena cava superior. The right azygos
vein (the old right posterior cardinal vein) opens at last, as at first,

CHAP. x. ] THE DEVELOPMENT OF THE CAT. 349

into what was the right ductus Cuvieri and what is ultimately the
vena cava superior. The left azygos veins (the old left cardinal
vein) opens at last, as at first, into what was the nght ductus
Cuvieri, and what is ultimately that part of the superior intercostal
vein which is nearest to the left innominate vein.

After birth and the cessation of the placental circulation, the
ductus venosus diminishes and becomes obliterated, save as that fibrous
cord, the round ligament which traverses the liver. The umbilical
vein also disappears, save as that part of the round hgament which
extends from the umbilicus to the hver. Thenceforth all the blood
returning from the stomach and intestines is compelled to circulate
through the portal and hepatic veins on its way to the heart.

Those parts of the umbilical arteries which are within the body—
the hyogastric arteries—similarly abort where they intervene be-
tween the bladder and the umbilicus, becoming merely two fibrous
cords. Those parts which intervene between internal iliacs and the
side of the bladder, persist as the superior vesical arteries.

The DEVELOPMENT of the LYMPHATIC SYSTEM resembles more or
less that of the blood-vascular system. The small /ymphatics
originate by the junction of nucleated cells, and they spread and
increase through the development of peculiar cells, which branch
out and join fine processes given off from the lymphatics formed
earlier. The lymphatic glands appear to be developed from clusters
and aggregations of lymphatic vessels from which diverticula grow
out. The lymphatic corpuscles probably originate from subdivision of
cells contained within the early formed lymphatic vessels and glands,
also in the spleen and perhaps im the thyroid and thymus glands.

The fluid lymph may be regarded, like the fluid blood, as the
blastema of a tissue of which the white corpuscles represent the
nucleated cells.

§ 15. The Lunes are at their origin small outgrowths from the
alimentary canal (Fig. 155, 7). This canal, at a pot immediately
behind the heart, becomes laterally constricted by two lateral in-
foldings of its walls, which divide it into a narrower upper, and a
broader lower (or ventral) channel, while the lower channel tends
to be subdivided by a median longitudinal upgrowth from its floor.
This process continuing, three tubes come to be formed, whereof the
dorsal one is the future cesophagus, while the two ventral ones
become the two lungs, which thus arise as two diverticula, lined
with hypoblast, from the ventral aspect of the cesophagus. These
little sacs elongate by degrees, and ultimately come to hang by a
single and common supporting tube, the future trachea. Ramifica-.
tions of the primitive cavity into the mesoblastic tissue surrounding
it, form the bronchial tubes, with their branches.

In contrast with the liver, the lungs of the foetus are exceedingly
small, but as soon as the first inspiration has taken place, they
rapidly increase in size and weight, while their consistency changes
from that of a granular, compact, heavy substance, to a light and
Spongy texture.

oe el a) ee i

B80) THE CAT.

The Larynx first becomes visible by the rudiments of the cartilages
which appear about the primitive glottis, the arytenoids seeming to
be the first, and the epiglottis the last to appear.

The sPLeEN is formed entirely from the mesoblast, a thickening
of which appears on the left side of the stomach, near the pancreas.
No prolongation from the alimentary canal ever enters it, or even
appears in connexion with it. :

The THYROID BopDy arises as a small diverticulum, lined with hypo-
blast, from the anterior wall of the pharynx, and consists of isolated
vesicles, within which are rounded cells, the vesicles multiplying by
constriction and division—or by budding out and separation—of
such protruded parts. It is larger relatively in the fostal and young
condition than in adult age.

The THYMUS GLAND is a body which makes its appearance as
a tube with granular contents, surrounded by tissue into which
small vesicles bud forth, laterally, from it—which vesicles themselves
again branch. ‘The thymus is relatively larger at birth than subse-
quently but it still remains of large size, even at maturity.

§ 16. The first URINARY oRGANS which make their appearance
in the embryo are not the kidneys, but certain temporary urimary
glands called the WoLFriAn BopiEs (Fig. 151), which early attain
a large relative size. Afterwards their place is taken by the true
kidneys. The Wolfhan bodies entirely losing all secreting power, and
more or less aborting, become (in one or the other sex) either im-

ortant or merely functionless appendages of the generative organs.

The Wolffian bodies make their appearance in the embryo (at a
time when the intestinal canal still communicates widely with the
umbilical vesicle) as a slight ridge on each side of the primitive
mesentery, and each body grows to be a reddish oblong mass beside
the vertebral column, reaching from the heart to the hinder end of
the abdomen. It consists of a series of tubes all opening into a
duct which runs along the outer border of the Wolffian body. Hach
tube is somewhat convoluted and dilated at its blind end as a Mal-
pighian bedy, into which a vascular glomerulus enters, just as in
the true kidney—the Wolffian bodies being very vascular. The
ducts of the two Wclffian bodies open near together into the root
of the allantois.

The first parts to be developed of the Wolffian bodies are their
ducts, which appear to arise from a series of invaginations (from the
primitive pleuro-peritoneal cavity) into that part of the mesoblast
which lies in the angle between the diverging somatopleure and
splanchno-pleure. The blind ends of these invaginations grow out
laterally and coalesce, so as to form a rod traversing the mesoblast
antero-posteriorly, while the invaginations, which originally led
from the peritoneal sac, close up and disappear. ‘The central part
of the rod developes a cavity, and thus the tube of the Wolfhan
ducts comes to be formed. After this, diverticula bud off laterally
from this duct, and so the tubes which end in the Malpighian
bodies come to be formed.

fomandgy

THE DEVELOPMENT OF THE CAT. 351

OHAP, x.]

While the Wolffian bodies are forming, another, single, invagina-

tion is formed on its inner side, and this closes over, extends, and
becomes a tube called the MuLLeR1an pucr. The two Mullerian
ducts, which end blindly at their anterior end, extend backwards,
meet and coalesce where they open (side by side and between the
two Wolffian ducts) into the proximal part or root of the ailantois.

The aLantots itself, as has already been said, grows forth as a
membranous sac from the hinder end of the ventral aspect of the
primitive alimentary canal, and extends out between the somato-
_ pleure and splanchnopleure to the inner surface of the chorion in
the umbilical cord.

As the visceral plates of the somatopleure close round the belly of
the embryo, they come finally to embrace the umbilical cord where
it quits the body.

The part of the allantois which is within the abdominal cavity,
becomes differentiated into what are ultimately (1) the proximal part of
the urethra, (2) the bladder and (3) the wrachus: the urachus being that
part of theallantois intervening between the bladder and theumbilicus,
or navel. The cavity of the urachus becomes narrower and narrower
till it closes, and so this part becomes transformed into a ligament,
with traces, perhaps, of its primitive cavity. The proximal part of
the allantois opens at first into the hinder end of the primitive
alimentary cavity, but by degrees a partition (the future perineum)
grows forwards horizontally, and divides the dorsal alimentary
chamber, or rectum, from the ventral wrogenital sinus, into which
latter (the commencing proximal part of the urethra) the Wolffian
and Mullerian ducts open (Fig. 158, A).

The KipNEyYs begin to appear as two oval dark-coloured bodies,
each placed behind and above the very much larger Wolffian
bedy of the same side. Nevertheless, each kidney is at first larger,
compared with the bulk of the whole body, than in the adult.

The kidneys themselves arise subsequently to the development of
their ducts, the wreters. These latter seem each to be formed from
a dilatation of part of the Wolffian duct, which becomes constricted,
and so the ureter arises as a separated-off diverticulum of such duct.
This diverticulum, however, grows downwards and backwards, and
opens, not into the urogenital sinus, but into the bladder (Fig. 158, A,
6) which is separated from that sinus by a constriction.

From the anterior end of each newly formed ureter diverticula
grow forth into the mesoblast, and these diverticula lengthen, become
greatly contorted, and end in true renal Malpighian corpuscles. It
may be, however, as some contend, that the various parts arise
separately in the formative tissue, each part at first being solid, but
subsequently acquiring a cavity, and all ultimately uniting together.

The sUPRA-RENAL CAPSULES arise quite independently of the
kidneys. For a time they are much larger than the last named
organs. They appear to originate as a single mass in front of the
kidneys, subsequently becoming divided into two lateral organs.

The TrsrEs appear after the Wolffian bodies, but before the

Pe ee ee Se Se ee eee ee

352 | THE CAT. [omar x,

kidneys, as two small whitish oval masses of tissue, placed one on
the inner side of each Wolffian body, and arising as buds from the
mesoblast, between the diverging somatopleure and splanchnopleure.
Soon the cells of which they are composed become divided by septa
of connective tissue, and the cells themselves grow into the tubul
seminifert. Meanwhile, the tubes of the Wolffian body become
approximated to, and ultimately united with, the testis, and form
the casa efferentia and cont vasculosi of the epididymis, the duct of
the Wolttian body becoming the vas deferens, some of its detached
tubes forming the vas aberrans and Organ of Giraldes.* The testes
ultimately descend from the abdominal cavity into the scrotum,
which is formed by the median junction of two folds of skin, which
grow from the sides of the external opening of the urogenital sinus.
The penis first appears as a small recurved process projecting
from the front margin of the urogenital opening (Fig. 158, A, rp),
consisting of what are to be the corpora cavernosa, with a portion
of corpus spongiosum at its distal end and extending down the
grooved ventral, or posterior, surface of the developing organ. ‘The
lateral margins of this groove grow over and close, so converting the
groove into a canal—the spongy portion of the urethra. This canal
then opens posteriorly into the front end. of the urogenital sinus,
which still opens externally at the root of the penis, though
separated from the anal aperture by a transverse partition, the
incipient perineum. By degrees this inferior opening of the uro-
genital sinus grows over and closes, and thus the spongy urethra
comes to form one continuous tube with the urethra as it quits the
bladder, while the posterior end of the ventral surface of the penis
becomes continuous with the medianly coalesced lateral folds which
have formed the scrotum and invested the place where wasthe external
opening of the urogenital sinus at the root of the developing penis.
The ovary arises just as does the testis, and is at first indistin-
guishable from it. Soon, however, it comes to differ somewhat in
shape, and ova and Graafian vesicles arise from the very first within
it. It does not form the same kind of adhesion to the Wolffian
body as do the testes, but its stroma is formed by outgrowth of
tissue into it from the Wolffian body. A fibrous cord, the round
ligament, comes to connect the ovary with the pubis through the in-
guinal ring, but the ovary never passes outside the abdominal cavity,
though it descends a little from its primitive position. It becomes
wrapped round by the fold of peritoneum, the broad ligament, which-
is reflected on each side from the uterus, so that no discharge of its
contents can take place without rupture of its peritoneal investment.
The vagina and uterus arise as the partially conjomed hinder -
ends of the two Mullerian ducts, which open into the dorsal wall of
the urogenital sinus (Fig. 158, B). The simple tube comes by
degrees to alter in size and structure in different regions, its deeper
portion becoming very muscular (as the uterus) and separated from
the hinder part, the vagina, by a constriction forming the os uteri

* See ante, p. 244.

GHAR, .X. |

™m—-
k Ti
1’ wy
oF
atl |

@9 oo I” :

WWE gae v

'

~ BRR ASW

THE DEVELOPMENT OF THE CAT. 353

SS uh
b ff
KY ie

Fig. 158.—DIAGRAM OF THE DEVELOPMENT OF GENERATIVE ORGANS. THE BODY IS SUPPOSED TO
BE CUT THROUGH VERTICALLY, AND THE URINARY AND GENERATIVE ORGANS OF THE
LEFT SIDE TO BE VIEWED LATERALLY.

A. The earliest or neutral condition, the sexual

gland (sg) being as yet undifferentiated into
either ovary or testis, and the Wolffian
body (w) and duct (wd), and the Mullerian
duct (m), all co-existing with the permanent
kidney (%) and ureter (ut), the papilla (rp) on
the ventral side of the opening of the
urethra (uh) being rudimentary.

B. Here the neutral state is changing into the

complete female condition. The sexual
gland {sgo) has become an ovary. The
Wolffian body and duct (w and wd) have
almost aborted. The remnant of the
Wolffian body (w) has become the far-
Ovarium and Gaertner’s duct. The Mul-
lerian duct (m) has expanded and opened at
its free end, and become a Fallopian tube,
the lower end of which has coalesced with
its fellow of the opposite side to form the
vagina (v) and uterus (us). The opening
of the cornu of the right side is seen at oc.

C. Here the neutral state is changing into the
complete male condition. The sexual
gland (sgt) has become a testis, and has
travelled backwards and downwards into
the scrotum (s)—its original position being
indicated by dotted lines. The Mullerian
duct (m) is reduced to a rudiment, the pros-
tate has developed (pg), and the rudimentary
papilla has become a relatively large organ
(»), which is represented as truncated.

a. Analaperture. al. Allantois. 0. Bladder.

ce. Clitoris. k. Kidney. m. Muller’s duct.

oc. Opening of right uterine cornu into uterus.
pg. Prostate gland.

rp. Rudimentary papilla, which becomes the
penis in the male.

s. Scrotum.

sg. Undifferentiated sexual gland.

sgo. Ovary. sgt. Testis. uh. Urethra.

us. Uterus. ut. Ureter. v. Vagina.

yw. Wolffian body. wd. Wolffian duct
AA

354 THE CAT.
(Fig. 158, B). The two upper ends of the Mullerian ducts, above —
where they begin to form the uterine cornua, open at their deep
ends, as alr eady described, thus becoming the Fallopian tubes,
which lead from the peritoneal cavity into the uterus.

The fundamental similarities of the parts in the two sexes may —
be expressed as follows (Fig. 158, A, B, C): the primitively formed
Wolfhan body becomes in the male the vasa efferentia and coni
vasculosi, otherwise it vanishes, save that the vas aberrans and
hydatid of Morgagni, with the organ of Guiraldes,* may be its more
or less persistent relics. In the female both the Wolffian body and
its duct practically disappear, the parovarium and Gaertner’s duct
being persistent remnants of them. In the male the Wolffian duct
becomes the vas deferens. The Mullerian ducts, on the contrary,
entirely disappear, except that the relics of their conjoied ends
persist as the wéricle or sinus pocularis; while in the female, the
Mullerian ducts become the oviducts, the uterus and the vagina.
Thus the utricle is the minute male uterus. The small body formed
on the front margin cf the cloaca becomes in the male the penis,
the clitoris in the female. ‘The groove which traverses it below and
behind, closes in, in the male, to form the spongy urethra; in the
female it remains open. ‘The folds of integument which lie on each
side of the urogenital aperture, persist as such folds in the female,
but, in the male, unite ventrally in the middle line to form the
scrotum. The glands of Bertholin correspond with those of Cowper,
but the prostate of the male has no, as yet discovered, analogue in ~
the female.

The development of the spermatozoa has been already described,
together with the description of the testis. Ova arise simply as
epithelial cells, such as those which invest the incipient ovary, and
generally line the peritoneal cavity. They also arise as (and from
amongst) epithelial cells more deeply placed ; in the ovary; but it is
not certain whether such deeper cells arise inside quasi-glandular
tubes formed of inflected superficial epithelium, or whether they are
deep-seated because the connective tissue stroma of the ovary has
grown outwards and enclosed them.{ The ordinary sized germ-
epithelial cells are about =, of an inch im diameter. The sub-
stance of the ovary by which these cells become enclosed, is an
outgrowth from the Wolffian body.

The epithelial cells become thus enclosed in groups or ‘ nests,”
and some of them, enlarging in size and acquiring much clear
protoplasm around their nucleus, es what are called primitive
or primordial ova, which average about +,)5>5 of an inch in diameter.
Other adjacent epithelial cells divide and multiply, and form a

* See ante, pp. 244 and 250. paper by Dr. Foulis, in the Trans. of
+ See ante, p. 245. the Roy. Soc. of Edinb., vol. xxvii.,
~ As is the opinion of Mr. F. Balfour. | p. 345, and another by Mr. EH. A.
See Quarterly Journal of Microscopic Schifer, on the Pro. Roy. Soc., 1880,
Science, October, 1878, p. 418, and | p. 245.
Embryology, vol. i., p. 47. See also a

CHAP. X.] THE DEVELOPMENT OF THE CAT. 355

cellular investment, or follicle, around the primordial ova, and
ultimately grow into the tunica granulosa within the Graafian
vesicle. Sometimes two or more of the ova-forming epithelial cells
of a nest, will coalesce and form a large protoplasmic mass with two
or more nuclei, and thus a cell may arise and then be nourished by
appropriating the substance of other cells. An enlarged epithelial

Fig. 159.- PorTION OF THE OVARY OF A KITTEN ABOUT THREE WEEKS OLD, SHOWING THE GERM-
EPITHELIUM AND PRIMORDIAL OVA, WITH LARGE EGG-NESTS MORE OR LESS SUR-
ROUNDED BY StTRoMA (Fovlis).

a. Primordial ova. c. Large clusters of germ epithelial cells, i.e.
b. Smaller cells, resulting from the fission of larger large egg-nests.

epithelial cells, and beginning to form the d. Large germ epithelial cells.

membrana granulosa. e. Stroma of ovary.

f. Germ epithelial cells.

cell, or primordial ovum, when it has become enclosed in a follicle,
becomes a “permanent ovum.’ The protoplasm, or vitellus, accu-
mulates about the nucleus or germinal vesicle, which developes a
nucleolus, or spot, while the zona pellucida forms either just within or
externally to a delicate membrane investing the vitellus. The ovum,
with its epithelial lining and external mvestment of fibrous vascular
stroma, is a “ Graafian follicle.” At first the ovum itself is closely
embraced by the follicle. Afterwards the follicle greatly enlarges,
and its contents separate into (1) the cells of the membrana granulosa,
lining the vesicle and enclosing (2) a fluid, (3) the ovum, and (4) an
ageregation of cells— the discus proligerus—which remains adherent
around the ovum. The ovary at first contains thousands of incipient

ova, but the great majority disappear as development proceeds. When

the kitten is but from two to four weeks old a very large part of the
whole ovary consists of egg-clusters, but at five months old there is only
a zone of young eggs left immediately beneath the tunica albuginea.*

§ 17. The NERVoUS sysTEM, though a unity in its fully formed
condition, is more diverse in its origin than is the alimentary
system. The latter system, as has been shown, arises as a groove

* See Dr. Foulis, 7. c., p. 373.
AA2

356 THE OAT, : [cHAP. x.
of the mesoblast, open downwards and lined with hypoblast, which
gradually becomes converted into an elongated canal, from which
secondary, more or less ramifying tubes (also lined with continua-
tions of hypoblast) grow out.

The nervous system also arises as a longitudinal axial groove of
the mesoblast (lined with epiblast) extended above the alimentary
groove and open in the opposite direction, namely, upwards. This
eroove also becomes converted into a canal and forms the basis of
the cerebro-spinal axis, but the mass of the nerves do not arise as
outgrowths from it, but by modification and transformation of parts
of the mesoblast into nerve substance, such incipient nerves becoming
attached to the independently formed cerebro-spinal axis.

The medullary groove (except its more anterior part, which
becomes the brain, as hereinafter described.) becomes the sPrNnaL
MARROW, as follows:—The ascending dorsal lamine meet together
above and convert the groove into a canal, first, in the cervical
region. The layer of epiblast which lines the canal thickens very
much on each side, its innermost layer (of columnar cells) becoming
epithelium, its outer layer becoming the grey matter of the spinal
cord, and consisting of numerous small nuclei, each surrounded by an
-ageregation of protoplasm. Outside this the white matter of the
spinal cord is formed by transformation of the cells of the adjacent
portion of mesoblast. The-central canal of the developing cord
having become relatively elongated from above downwards through
the lateral thickening of its walls, becomes next constricted by an
ingrowth from each such lateral wall. These ingrowths continue till
they meet, the canal becoming thus divided by a transverse partition
into a dorsal and ventral canal. Then the roof of the dorsal canal
becomes absorbed, and this dorsal part of the primitive medullary
canal (now again become a groove) is: the posterior (dorsal) median
fissure of the adult spinal cord. Meantime the white substance of
the ventral aspect of the developing myelon grows out on each side,
leaving, however, a median interspace which becomes in the adult
the anterior (ventral) median fissure, which has thus quite another
origin and nature from the posterior (dorsal) median fissure. ‘That
part of the primitive canal which is on the ventral side of the trans-
verse partition (formed by the coalesced lateral ingrowths above
mentioned,) persists as the canalis centralis of the spinal cord of the
adult. The cervical and lumbar enlargements of the spinal cord
soon make their appearance, and the canalis centralis is also some-
what enlarged in those two regions. The myelon is at first
co-extensive with the neural canal of the skeleton, so that there is
no cauda equina. Afterwards, however, its growth does not keep
place with that of the skeleton, and thus the roots of the hindermost
spinal nerves become more and more elongated, and the formation
of a cauda equina thence results.

At its proximal end the spinal cord merges into the medulla
oblongata by the thickening of the floor and sides of the primitive

ee ee re es ee
* pe oS. = Tak

- CHAP. x. |

ct eatin Wee sera s
he he ;

ne Ae oe eee eee, tae Oe en Oo aly Ai eel a =. Se

THE DEVELOPMENT OF THE OAT. oo7

roove and the approximation of the roof of the canalis centralis to

the dorsal surface.

Fig 160.—D1acraM oF BRAIN DEVELOPMENT, TO SHOW THE ESSENTIAL RELATIONS OF ITS PARTS.

A. The brain in its earliest condition of three
hollow vesicles, the cavity of which is con-
tinuous with the wide cavity (d) of the
primitive spinal marrow (m). The brain
substance forms an envelope of nearly equal
thickness throughout. The wall of the
anterior end of the first vesicle is the
lamina terminalis (f). ;

B. Here the first vesicle or fore-brain has de-
veloped the pineal gland (pn) above, and
the pituitary body (pt) below, the cerebral
hemisphere (cr) are beginning to bud forth
from the front part of the first vesicle.

C. The cerebrum is here enlarged, and has begun
to bud out into the olfactory lobes (0). The
cavity of the cerebrum (or incipient lateral
ventricle) communicating with that of the
olfactory lobe in front, and with that of the
first cerebral vesicle (i.e., with the third
ventricles) behind. The latter communica-
tion, takes place through the foramen of
Monro (fm). The walls of the three cerebral
vesicles are becoming unequal in thickness,
and the cavity of the middle vesicle (b) is
becoming reduced in relative size, as the
iter « tertio ad quartum ventriculum. The
thickened upper part of the cerebrum (/) is
what is to become the fornix. The thickened
roof of the middle vesicle has divided into
the corpora quadrigemina (qg), and the
roof and floor of the third cerebral vesicle (c)
have thickened into the cerebellum (cb) and
pons Varoli ( pv).

D. The figure shows the cerebrum more en-
larged, with its cavity bifurcating into the
prolongations (the cornua). The fornix has
come to look backwards, and two lines

(below the figure 3) indicate its prolongation
downwards and backwards into the corpora
mamuillaria (ma).

E. Here the cerebrum is still more enlarged,
extending backwards over the corpora
quadrigemina and part of the cerebellum.
The fornix is shown bordering the descend-
ing cornu (de) of the lateral ventricle, and
extending into the temporal lobe (t1).

a. Fore-brain.

ac. Anterior cornu

b. Mid-brain. ’

ec. Hind-brain.

cb. Cerebellum.

er. Cerebrum.

de. Descending cornu.

d. Cavity of the medulla.

Jj. Fornix.

g. Corpora quadrigemina.

i. Iter a tertio ad quartum ventriculum.

m. Medulla oblongata.

ma. Corpora mammillaria,

o. Olfactory lobe.

pv. Pons Varolii.

gn. Pineal gland.

pt. Pituitary body.

r. Crura cerebri.

t. Lamina terminalis.

il. Temporal lobe of cerebrum.

xz. Space enclosed between the backwardly-
extended cerebrum and the much narrowed
roof of the third ventricle, which has now
become the velum interpositum.

2. Lateral ventricle.

3. Third ventricle.

4. Fourth ventricle.

The BRAIN is first indicated by the expansion of the pre-axial
- end of the medullary groove into what becomes the first or most

anterior cerebral vesicle or fore-brain.

To this succeed two other

358 THE CAT.
vesicles, namely, those of the mid-brain and the hind-brain. The
fore-brain, called also the deutencephalon, contains the anterior —
termination of the primitive medullary canal, and this becomes the
third ventricle ; the pre-axial wall of the first vesicle becoming the
lamina fearmahe of the adult. The optic thalami, optic nerves,
pineal gland and infundibulum, are formed from this vesicle.

The mid-brain, called also the mesencephalon, contains that part
of the primitive medullary canal, which ultimately becomes the zter
a tertio ad quartum ventriculum, The cor ‘pora quadrigemina above
and the crura cerebri below, are formed about this ventricle.

The hind-brain contains the cavity of the fourth ventricle, which
is not all roofed over dorsally by nervous substance. The anterior
part of this third vesicle is sometimes called the Hpencephalon, and
this gives rise to the pons Varolii below and the cerebellum above, the

Fig. 161.--Four ViEws oF THE BRAIN OF AN EMBRYO KITTEN IN THE STAGE WHERE IT FIRST ~
DIVIDES INTO THE FIVE CEREBRAL RUDIMENTS—SHOWING THE ACTUAL PROPORTIONS
OF THE PARTS. MAGNIFIED THREE DIAMETERS.

A. The brain, seen from above. 5. Medulla oblongata, or myelencephalon.
B. From the side. 0. Optic nerves.
C. Vertical section, showing the interior. V. Fifth pair of nerves.
D. From below. VIII. Glosso-pharyngeal and pneumogastric
1. Cerebral hemispheres, or prosencephalon. nerves. ;
2. Region of the third ventricle—the thalamen- 0. Infundibulum.
cephalon or deutencephalon. vv’. General ventricular cavity, opening ante-
3. Region of the corpora quadrigemina, or riorly into the lateral venumele by the fora-
mesencephalon. men of Monro.
4. Cerebellum or epencephalon.

latter arching back and covering over the hinder part of the fourth
ventricle. The posterior part of the third vesicle or hind-brain, is
sometimes called the myelencephalon or metencephalon, and this gives
rise to the medulla oblongata.

From the anterior part of each side of the fore-brain another vesicle
grows out. ‘These together form the cerebral hemispheres, called also
the Prosencephalon, which give rise to the corpora striata, fornix and
corpus callosum. The cavity within these outgrowths are the Jateral
ventricles, and the aperture by which they are continuous with the
cavity of the Deutencephalon (or third ventricle) is the future
foramen of Monro.

From the anterior part of the floor of each cerebral hemisphere
yet another vesicle buds forth. This is the future olfactory lobe or
nerve, called also the Rhinencephalon. Fach such lobe at first like-
wise contains a cavity continuous with that of the lateral ventricle of
its own side; but this olfactory ventricle is obliterated in the adult. _

The cerebral vesicles as they develope undergo a noteworthy

euar. x] THE DEVELOPMENT OF THE CAT. 359

INFLEXION. At first they follow one another in a straight line.
Afterwards the fore-brain and mid-brain bend downwards and for-
wards over the front end of the notochord, while that part of the
hind-bram which forms the cerebellum, bends upwards upon the
portion which forms the medulla.

The various parts which form themselves out of the three primary
hollow vesicles, grow at very different rates. The cavities of the
three vesicles and the olfactory lobes remain relatively small, but
the increase in bulk of the cerebral hemispheres is much greater than
that of the other parts. Moreover these cerebral hemispheres become
connected together by an outgrowth of nerve substance from their adja-
cent sides a little above the fornix, such outgrowth resulting in the
formation of a mass of transverse connecting fibres, which become
the corpus cALLosuM. This transverse growth comes thus to enclose
that space which was originally the deepest part of the great longi-
tudinal fissure, which space is, of course, bounded on each side by a
part of the inner wall of one of the cerebral hemispheres. These:
portions of such inner walls become exceedingly thin and form.
together the septum lucidum, the space included between them and
which is bounded above by the corpus callosum, becoming the ji/th
ventricle. It is plain, therefore, that the fifth ventricle is quite
different in nature and origin from all the other ventricles of the
brain, since these latter are remnants of, or outgrowths from, the
primitive medullary groove and canal of the embryo, while the fifth
ventricle, on the contrary, is as it were a portion of outside space
which has been enclosed and taken into the brain by means of those
inward lateral outgrowths which form the corpus callosum.

The FornIx is formed by two sets of longitudinal fibres, which are
developed (one bundle on each side,) from the upper zaargin of the
foramen of Monro, while the median junction of these two lateral
bundles form the so-called body of the fornix. Thus the fornix is the
median part of what was originally the back or underside of the
cerebral hemispheres, its body forming part of the outer wall or bag
of the cerebral hemispheres enclosing the lateral ventricles. As
these hemispheres grow backwards, the two prolongations of the
fornix (or its posterior pillars,) extend (following the course of the
developing “ temporal lobe,’’) backwards and downwards, one in the
wall of each hemisphere, as a bundle of longitudinal fibres, such
bundle projecting into the descending course of the latexal ventricle
as part of the hippocampus major. Its anterior pillars descend in the
lamina terminalis to the corpora mammiullaria.

The cerebral hemispheres, with the fornix as part of their wall,
having grown backwards: over the mid-brain containing the third
ventricle, the space between the roof of that ventricle, the veLuM
INTERPOSITUM, and the body of the fornix which comes to be applied
to the velum, is thus essentially the owtside of the brain, though as
a fact it is-actually in the very middle of that great complex struc-
ture, the brain of the adult. The vedwm consists only of ependyma,
the pia mater and the arachnoid. The vascular membranes called

asthe GAEL GA hr Ba nig

360 THE CAT. [cuar. x.

choroid plexuses, are but its margins which have become very vascular,
and the choroid plexuses of the lateral ventricles are also (as has —
been before pointed out) merely portions of the ependyma which have
become very vascular, and are by no means intrusions from without
into the true cerebral cavity. The vascularity is, in fact, continued
on in that portion of the ependyma which lines the foramen of Monro
and the lateral ventricles. The membranes which invest the brain
externally never enter the ventricles at all, but are (as has been
already said) reflected back on the under surface of the fornix.

The THIRD VENTRICLE, which has (as has been said) the velum
for its roof, grows out below into the infundibulum. The pineal gland
is formed in connexion with the roof of the third ventricle from behind
the velum. The pituitary body comes from the mouth—see p. 343.

The sides of the third ventricle, unlike the rest of its walls,
become greatly thickened to form the optic thalami, while its
anterior wall, the /amina terminalis, becomes thickened in places and
so forms a band of transverse fibres, the anterior-commissure (connect-
ing the corpora striata) and also a pair of vertical bundles (the
anterior pillars of the fornix) extending into the fornix above, and
into the corpora mammillaria below. The two optic thalami also
become connected by two sets of transversely extending nervous
structures. The first and more anterior is formed of grey matter
and is called the soft commissure, the more posterior, formed of
nerve fibres, is called the posterior commissure. The coRPORA
QUADRIGEMINA arise as an outgrowth from the roof of the mid-
brain, and one containing’ a cavity continuous with that of the,
second cerebral vesicle. The corpora are at first of very large
relative size, but they seem, as it were, to lag behind in growth,
become solid, and ultimately divided, first mito two lateral halves,
and ultimately into nates and testes.

Concomitantly with the development of the corpora quadrigemina,
the floor of the mid-brain becomes greatly thickened by the develop-
ing crura cerebri, and thus the primitively large cavity of the
mid-brain becomes reduced to the very narrow iter a tertio ad quar-
tum ventriculum.

Each CEREBRAL HEMISPHERE is also a bag, the walls of which.
are very unequally thickened. Part of the inner wall, along the
descending cornu, is reduced to mere ependyma, with pia mater and
arachnoid, so that it tears very easily, the rupture thus produced
having (in man) been called the fissure of Bichat and taken for a
natural opening. Each corpus striatum is a thickening of the outer
and under wall of each hemisphere abutting against the front and
outer part of the optic thalamus behind it, and forms the axis round
which the whole hemisphere is developed.

Slight depressions begin sooner or later to appear on the surface
of each hemisphere, the beginnings of the future gyri and suled.
These increase very gradually as the cerebrum grows upwards and
backwards.

The MEMBRANOUS INVESTMENTS OF THE BRAIN arise in different

Lt pow alti a ie ead Ie ee oe o

cmap. x.) THE DEVELOPMENT OF THE CAT. 361

modes. The dura mater is formed from the inner surface of the
dorsal plates external to the cells which become the nervous centres.
The pia mater and the arachnoid, on the contrary, are formed by
transformation of the outer layer of the primitive brain mass itself.
Thus no part of these tissues, whether choroid plexuses or what
not, extend and grow into fosse and cavities of the brain, but they
actually arise and are first formed there where they ultimately
exist.

The CRANIAL NERVES arise as four small opaque pear shaped
masses of nervous tissue, which grow from the epiblast on each
side of the hind brain in front of tke protovertebree on each side.
Of these four pear-shaped masses (the wider ends of which are
directed inwards to the axis of the body), two are placed in front
of and two behind the auditory vesicle. The first of these masses
becomes the fifth nerve, and bifurcates, one branch becoming the
ophthalmic nerve, the other the 2nd and 3rd branches. The
second mass becomes the facial nerve. ‘The third mass becomes the
glosso-pharyngeal, and the fourth the pneumogastrie.

The DEVELOPMENT OF THE EYE is brought about by the con-
currence of three different processes or growths. 1. An outgrowth
from the bram. 2. An ingrowth from the skin. 3. An upgrowth
of the mesoblastic tissue which surrounds the developmg eyeball,
into a certain part of its interior.

The outgrowth of the encephalcn is in the form of a hollow
process of the fore-brain, containing a prolongation of its cavity,
the future third ventricle—just as the olfactory lobe contains at first
a prolongation of the prosencepialic cavity. This ocular outgrowth
is called the primary optic vesicle. It ultimately developes mto a
narrow stalk and an anterior distal expansion. The stalks of the
two primary optic vesicles are at first placed close to the junction,
on each side. of the cerebrat vesicle with the vesicle of the third
ventricle. Each is at first disconnected with the other altogether,
but little by little the root of each extends over to the opposite side
of the brain, while their fibres, where they come thus to cross, inter-
mix together, and so a chiasma is formed. The distal expansion of
each primary optic vesicle gets (by apposition with other structures
to be shortly described) doubled in upon itself, so as to become
cup-shaped, and to present a concavity forwards and outwards, the
secondary optic vesicle, or optic cup, while by degrees its cavity be-
comes altogether obliterated, as also that of its stalk.

Meanwhile a depression of the external cuticle has indicated ex-
ternally the place of the future eye. This depression deepens while
its lips approximate till it forms a closed sac lined by the epiblastic
epithelium which coated the invagination. This sac becomes applied
to the anterior cup-shaped surface of the optic cerebral outgrowth.
The walls of the sac then thicken, especially behind, and obliterate
its cavity. Its posterior portion certainly becomes the /ens, and its
anterior portion either also becomes part of the lens, or is trans-
formed into the aqueous humour which, if it is not thus formed, is

—
=
a

362 THe Oates ae!

formed from a growth of mesoblast intervening between the incipient

lens and the epiblast. From the margins of the chamber of the
aqueous humour, a growth extends inwards on all sides which
becomes the iris, and divides the chamber into two portions. The

vitreous humour is formed by a growth of mesoblastic tissue up

through a fissure left below during the infolding of the primary optic
vesicle and formation of the optic cup. This fissure gets gradually

closed up, though traces of it, called the ocular cleft, may be discerned

for a considerable time. The mesoblastic tissue around the eyeball
becomes condensed into the sclerotic. ‘The external skin in front of

Fig. 162.—SEcTION OF THE COMMENCING EYE OF AN EMBRYO, IN THREE STAGES.

A. Commencement of the formation of the lens
by depression of a part of C, the epiblast. 5 .

pr. The primitive ocular vesicle or C. A third stage, in which the secondary optic
nervous outgrowth from the brain, vesicle—the upgrowth forming the vitreous

now doubled back on itself by the ! humour (v)—begins to be formed. The
depression of the commencing lens (J). | primitive cavity of the cerebral optic

within it. The optic vesicle has here
become more folded back.

B. The lens depression has become enclosed, vesicle (pr) is here reduced to a chink by
and the lens itself is beginning to be formed the still further infolding of that vesicle.

the eyeball developes a fold of membrane above and below. These
increase in size, and become the eyelids, their inner lining and the
epiblast coating the cornua being transformed into the conjunctiva.
The eyelids, when formed, become glued together at their margins
till nine days after birth. The conjunctiva is continuous with the
lining of the lachrymal canal, which latter is a persistent remnant
of the fissure, at first wide, which primitively exists between the
frontal and the maxillary processes of the embryo.

The DEVELOPMENT OF THE EAR, in so far as it arises by involu-:
tion of the epiblast, resembles that of the eye, but it differs from it
greatly in that there is no outgrowth from the brain corresponding
with such epiblastic involution. The first appearance of the future
internal ear takes place (at a very early period) on each side of the
hind-brain, when an involution of the epiblast forms a pit extending
down into the mesoblast, which lies externally to the cerebro-spinal
axis of that region. This pit deepens, and its margins close oyer
and unite, so forming it into a closed sac called the otic vesicle. This
vesicle becomes the internal labyrinth. The epiblast forms the endo-
thelium of that labyrinth which contains the endolymph. All the
structures external to this, namely, the fibrous structure of the
membranous labyrinth, the perilymph, and the solid structures which

*
a

-

tek Brak Se aan ee ee eT PA eet eee Jase obe Vea ees
z 49) 3 :
‘

PeeHAr.. -X. | THE DEVELOPMENT OF THE CAT. 363

invest it are formed from the mesoblast. The otic vesicle sends a
process inwards which becomes the scala media of the cochlea, which
again becomes separated off by a constriction (the future ductus
cochlearis) from the rest of the vesicle. From other parts of the otic
vesicle three rounded protuberances grow out, each of which becomes
first flattened and then absorbed, except at its circumference-—the
three protuberances thus becoming the three semicircular canals.
Two constrictions then show themselves in the wall of the large
part of the otic vesicle, thus separating the saccu/e from the part
adjacent to the semicircular canals which becomes the wtricle.

The auditory nerve is formed by direct transformation of the
mesoblast in configuity with the otic vesicle. It is at first distinct
and separate both from that vesicle and from the hind-brain, though
it grows each way, and becomes connected with both.

The cartilage which forms the auditory capsule (investing the
otic vesicle) is continuous with that of the basi-occipital region
—the parachordal cartilage. This capsule becomes ossified from
three centres, the pro-otic, opisthotic, and epiotic bones, as before
described. ‘These ossifications leave open two small apertures, one
in the outer wall of the cochlea, and surrounded by the opisthotic
bone—the fenestra rotunda—the other placed more inferiorly, oppo-
site the vestibule, it being bounded above by the pro-otic, and below
by the opisthotic—the fenestra ovalis.

The external meatus, tympanum, and Eustachian tube are formed,
as has been elsewhere said, by differentiation of the first visceral
cleft, while the auditory ossicles are formed as has been already
related.

The sides and floor of the tympanum, and ultimately the floor of
the external auditory meatus, become ossified as the tympanic bones.

From the margin of the second, or hyoidean, visceral arch, a
membrane grows out which becomes the external ear.

The DEVELOPMENT OF THE NOSE resembles that of the eye, inas-
much as an involution of epiblast, the primitive nasal sac, is related
to an outgrowth of brain-substance, the o/factory lobe of the cere-
brum. Lach of the nasal sacs deepens by outgrowth of its free
margin, but an inequality in the growth of that margin gradually
transforms it from a conical pit open forwards, into a groove or canal
leading backwards and inwards. Meantime the maxillary process
grows forwards and joins the naso-frontal process, thus bounding the
nasal sac below; while the external lateral nasal process bounds it
behind—intervening, as it does, between the nasal sac and the eye.
Thus the nasal sac comes to open behind into the front of the buccal
cavity, but ultimately (as has been already described) the develop-
ment (by lateral transverse growths) of the palate prolongs the nasal
canals backwards and so causes them to open into the hinder part of
the mouth. While this growth is going on, the ethmo-vomerine
cartilage (formed by the anteriorly coalesced trabecul) grows down
and embraces the nasal sacs, sending down three cartilaginous pro-
cesses, one between and one on each side of them. ‘The lateral

-

364 THE CAT.

cartilages develop processes which extend imwards, and lay the

foundations of the maxillo-turbinal bones. In the descending plates
of the ethmo-vomerine cartilage, the median and dateral ethmoudl bones
become developed.

§ 18. Thus all the various parts and organs of the adult animal
are gradually developed. But it is only by degrees that the fully
mature form is attained, the proportions of the head, limbs, and tail
of the kitten being obviously different from those of the full-grown
eat. Still the young animal is substantially similar to the old, even
in appearance, for, though blind, it is covered at birth with a hairy
coat, more or less resembling that of one or other of its parents.

But although the young one at birth 1s evidently a young cat, the
process by which the substance of the fertilised ovum has grown into
a kitten 1s a wonderfully circuitous one. For a certain time the
embryo cannot be said to bear any resemblance to its ultimate form,
while for a considerable period that resemblance is but a very general
and obscure one. Even the various organs, such as the brain,
heart, &c., are, when first formed, not the brain, heart, &e., of a
eat, nor does the course taken by the primitive blood- vessels corre-
spond with that of the blood-vessels of the adult. These transitory
conditions have, however (strange as it may appear to any readers
as yet unfamiliar with such subjects) resemblances and analogies
with structural conditions which are permanent in quite, other crea-
tures—in animals, that is, very different both in appearance and
nature from the cat.

This curious fact is one of great significance, and it 1s one of much
utility to us. Its utility we shall appreciate when we consider what
is the cat’s place in nature—a question which the phenomena of its
development will help us to determine. The full significance, how-
ever, of the developmental process will only appear when, at the
end of our inquiry, we apply ourselves to the consideration of
the problem of the cat’s pedigree and origin.

CHAPTER XI.

THE PSYCHOLOGY OF THE CAT.

§ 1. Tue word “ Psychology” has been so much used of late to
denote mental states only, that most readers will probably deem that
by the phrase “the psychology of the cat,” the phenomena of the
cat-mind—its feelings, imaginations, emotions, and instincts—are
exclusively referred to.

These indeed will all be treated of in this chapter, but “ Psy-
chology,” according to its original conception, and according to the
most rational signification which can be given to the term, has a
very much wider meaning; for it denotes the study of all the
activities, both simultaneous and successive, which any living
creature may exhibit.

On account of the very peculiar nature of a certain number of
these—namely, all those which may be classed as “ feelings”’ in the
widest sense of that word—it is practically impossible to study them
as they exist in any animal without some reference to our own
mental activities. ‘The study of such activities as they take place
in ourselves, may be followed up in three modes :-—

(1.) By mtrospection, 7.e., by the study of our own mental states,

through our powers of reflection.

(2.) By the study of our fellow-men as they live and act (in
health and in disease), drawing inferences from their words and
gestures as to the similarity between their feelings, emotions
and perceptions, and our own.

(3.) By examining facts of structure—anatomical conditions—in
order to investigate the relations which may exist between
different mental phenomena and corresponding (normal or
pathological) bodily conditions.

Such of our activities—such phenomena—as we know and can
know only by introspection, are called “ subjective,’ and they are
ministered to by the nervous system. That same system, however,
also ministers, as we have seen, to many other activities of which
introspection can give us no account, since they lie so deep that they
are beyond its ken.

Now it is these subjective phenomena, or, at the most, these
together with the other activities to which the nervous system

866 THE CAT,

ministers, which are now ordinarily referred to by the term
Psychology. Therefore it will be well, in studying the psychology
of the cat, to begin with such of its activities as may seem most to
resemble, and run parallel to, those human phenomena which are
known to us by introspection, together with such others as may be
most nearly allied to, or more or less inextricably mixed up with
them.

§ 2. We cannot of course, without becoming cats, perfectly
understand the cat-mind. Yet common sense abundantly suffices
to assure us that it really has certain affinities to our own. Indeed,
the cat seems to be a much more intclligent animal than is often
supposed. That it has very distinct feelings of pleasure or pain,
and keen special senses, will probably be disputed by no one. Its
sense of touch is very delicate; its eyes are highly organized, and
can serve it almost in the dark, and its hearing is extremely acute.
It is obvious also that external and internal sensations—more or
less similar to those external and internal sensations of ours by
which we instinctively move from place to place, judge of distance
and direction, and perceive resistance and pressure—must be
possessed by the cat also. Were it otherwise, trees could not be
readily ascended in search of birds, leaps could not be accurately
taken and mice caught, walls could not be ascended and descended
by dexterous combinations of vigorous yet delicately adjusted springs
and graplings, nor could small apertures be skilfully passed through
in the admirable way in which all these complexly co-ordinated
movements are effected by the animal in question. The ease and
grace of motion in the cat, and its neat dexterity, are a common
subject of praise. Who has not observed how cleverly a cat will
avoid objects in its path—walking, perhaps, over a table set with
glasses and ornaments in not very stable equilibrium, without over-
setting any one of them. Every one knows also the great facility
with which the cat so turns in falling as almost always to alight
safely upon its feet. The animal’s ordinary locomotion is a walk or
aspring. It rarely runs, save when it is pursued or alarmed, and
then it progresses by a series of bounds. When driven to it, it can
swim, though it takes to the water, or even endures a mere wetting,
with the greatest reluctance. Yet a cat has been seen voluntarily
to enter a small stream several times, in order to rescue its kittens
which had fallen into it.

But the cat has not only external and internal sensations: the
facts just referred to cannot be explained without also granting that
it has memory, imagination, a power of sensible perception, and ot
associating images in complex mental pictures which are more or less
associated with pleasurable or painful feelmgs—for unless a cat
perceived objects, it could not climb, jump, or pursue its prey. Nor
can we doubt, when the presence of a mouse causes the impression
of a patch of colour with a definite, familiar outline, on the retina ot
an experienced cat, that immediately there is a revival of faint
antecedent similar impressions, with relations of various kinds, and

cuar. xt] THE PSYCHOLOGY OF THE CAT. 367

pleasurable feelings (also faintly revived) of past catchings, killings,
tastings, and eatings. Moreover, when we recollect how common
it is for sleeping dogs to show by slight yelps that they are dream-
ing, we must surely admit that it is probable that cats can likewise
dream. Nor is it impossible that when cosily sitting before a
cheerful hearth, enjoying the heat they love so well, they may
indulge in waking “ day-dreams ” also.

As to memory, every one knows how cats attach themselves to
their homes, and how generally they recognize at least one or two
of the habitual inmates of their dwelling place. Everyone knows
also how a cat, accustomed to have a saucer of milk at tea-time,
will habitually run into the drawing-room with the servant carrying
the tea-tray. But even the preparatory clatter of the cups and
plates downstairs is often enough to arouse its sensibilities, and put
it on the gui vive. All this cannot be explained without allowing
that the cat-mind can associate complex sets of sensuous impressions
of different kinds—pleasurable or painful feelings being, as it were,
the cement which binds together such complex associations. Once
let a cat be much hurt by anyone, and it will soon show how it
has associated a painful feeling with his image.

But cats can so associate sensations and the images of objects in
various relations as to draw practical inferences. My friend,
Mr. J. J. Weir, tells me of a cat which, having been chased by boys,
ran towards a door, jumped up, put one paw through the handle,
and with the other raised the latch, thus causing the door to open
and enable it to escape. This action he saw several times repeated.
Mr. Harrison Weir has also assured me that he has seen a cat
unfasten a latch and then open the door it fastened, by pressing
its feet against the door-post. He has also had a cat that knocked
at a door with the knocker—these acts bemg untaught, and due only
to the cat’s spontaneous acts of cognition. I have also heard of a
eat which habitually jumped down from a staircase in such a way
as in its descent to press with its paws obliquely on the handle
of a door and so open it. My friend Captain Noble, of Maresfield,
informs me that he has himself known a cat which was in the habit
of catching starlings by getting on to a cow’s back and waiting till
the cow happened to approach the birds, which little suspected
what the approaching inoffensive beast bore crouching upon it.
He assures me he has himself witnessed this elaborate trick, by
means of which the cat managed to catch starlings which otherwise
it could never have got near. Many cats will readily learn the
signification of certain words, and will answer to their names and
come when called. Very strange is the power which cats may show
of finding their way home by routes which they have never before
traversed. We cannot explain this (as it has been sought to explain
the like power in dogs), by the power of smell being the pre-
dominate sense, so that a passed succession of smells can be re-
traversed in reverse order, as a number of places seen in succession
on a journey may be retraversed in reverse order by ourselves. On

i.

368 THE CAT.

the whole, it seems probable that the power in question may be due
to a highly developed “ sense of direction,” like that which enables
some men so much to excel others in finding their way about cities,
or that which enables the inhabitants of Siberia to find their way
through woods or over hummocky ice, and who, though constantly
changing the direction they immediately pursue, yet keep their
main direction unchanged.

In addition to all these cognitions of objects, and of the relations
between them, cats possess stroug passions and, often at least,
affectionate feelings of personal attachment.

The strength of their sexual feelings is notorious, and hardly less
so is the devotion of the mother cat to her young. This latter
emotion endures as long as she gives suck, and often, if a cat’s
second litter of kittens be destroyed while one of the previous litter
remains, the latter will be again taken into favour, and, resuming
its old mode of nourishment, have all the tenderness and affection
shown to it which was manifested towards it at first. . Cats will
sometimes (as before mentioned) show great regard to individuals,
and will manifest it by expressive gestures and slight, affectionate
bites. These antmals, then, have emotions, and they are able to
express their feelings by external signs. Some observers have
professed to detect more than half a hundred different expressions
in a cat’s face, but however much exaggeration there may be in
such a statement, it isimpossible to mistake their gestures of rage
and fear at the sight of a strange and threatening dog—gestures

well understood by the dog, and sufficient in most cases to keep him

at a safe distance. 7

But it is not only by gestures that cats express their feelings.
Besides their hideous nocturnal howls, cats give expression to their
desires by gentle sounds. Almost everyone must have met with a
cat which by mewing expressed its wish for a door to be opened, or
which thus begged for a little milk. Cats then have a language of
their own, made up of sounds and gestures.

Cats also have a will of their own, as all must know who have
tried to retain on the lap, a cat minded to go elsewhere, or who have
observed the determination with which they pursue the objects of —
their desires.

Manifestations of quite another kind from these quasi-intellectual
ones are, however, also shown by cats. For they possess true
instincts,* and blindly follow innate promptings in pursuit of ends of

* One of the to us unpleasing instincts
of the cat is that which prompts it to
play with the captured mouse instead of
killing it, the objectand meaning of which
have been regarded as inexplicable. My
friend Professor Paley has made the
following suggestion as to the true utility
and meaning of this instinct. He
writes :—‘‘ When we observe carefully
the motions of a kitten in playing with
a ball or a cork, and a string, we shall

see that they are suggested by the very
same instincts which are exerted by a
cat in playing with a disabled mouse.
In both there is the withdrawal and the
sudden pounce, and also the propelling
the motionless object with the claw.
It isa mistake to suppose that a kitten
is actuated solely by a love of sportive
play. Those who speculate on the laws
which allow the existence of human and
animal suffering, alike, profess them-

THE PSYCHOLOGY OF THE CAT. 369

PCHAP. XI. |

which they can have no cognition whatever. This is shown by
both parent and offspring at birth. The young spontaneously seek,
find, and suck from, the mother’s teats, while the young mother,
also yielding to the spontaneous promptings of her organization,
unhesitatingly gnaws thorough the monte cord of her first
kitten.

So also a kitten brought up without any experience of mice, will
pursue with eagerness, “eatch and kill the very first mouse which
comes in its way. ‘Ihese instinctive acts are acts which spring
necessarily from the structure of any organism, much as the
actions of a steam-engine must follow their designed course
when heat and water are duly supplied. Not, of course, that
they are altogether such: for the steam-engine is a mere machine,
while the animal is a living organism, endowed with much plasticity
of body, and (as we have seen) even with a power of drawing
practical inferences. Its instinct is, therefore, necessarily somewhat,
as it were, plastic also, and capable, within ane of accommodating
itself to changed circumstances.

Instinct, then, is a power of a kind distinct, on the one hand, from
even such intelligence as cats * have, and distinct from mere reflex
action on the other.t Attempts have been made to deny its existence
and distinctness,+ but they have only served to make them the more

manifest.

selves shocked at what they call the
““unnecessary cruelty’ of the cat. It is
worth while therefore to inquire if there
is not a reason that can be given for it
in the economy of nature. For to do this
is better than to view the circumstance
as one of the proofs of imperfection in
that economy. When we consider that
the prey of the feline race is usually
nimble, and that it can only be caught
by a pounce upon it, we shall see that
success in catching mice, birds, &c.,
must depend on constant practice. The
creature escapes and is recaught again
and again, and always by a pounce. ‘To
make real escape impossible, the victim
is nipped or disabled, but generally so
slightly that it may at first be taken
from the cat very little injured. It ‘is
clear that each capture is thus made a
lesson in catching. For everything
depends on the sudden and noiseless
dash. iM
* Mr. Douglas A. Spalding found
kittens to be imbued with an instinctive
horror of the dog before they were able
to see it. He tells us :—‘‘ One day last
month, after fondling my dog, I put my
hand into a basket containing four blind
kittens, three days old. The smell my
hand had carried with it set them puff-
ing and spitting in the most comical
_ fashion.” (Nature, October 7, 1875,
ep: 507.)

;
a
Bi:
a
Aas ff

+ ‘* Instinct, as instinct, is of course
an abstraction existing in the mind,
though it exists concretely enough in
animal actions of a special kind. In-
stinct is, concretely, the animal organism
energizing in certain ways.” “‘It is a
faculty of the feeling, imagining, organi-

cally-remembering “and “automatically-
acting soul, which faculty is in most
intimate connection with the organiza-
tion of each species, so that upon the
recnrrence of certain sensations, external
or internal, a definite series of ‘actions is
initiated, for the performance of which
the organization has been specially de-
veloped. It is action like reflex action,
save that it takes place in consequence
of feelings and imzginations. It is so
intimately yelated to an animal's struc-
ture, that if it were possible for us to
construct any given kind of animal, we
should necessarily give rise to the in-
stinct in giving rise to the structure.’
(Lessons from Nature, pp. 236 and
239.)

+ Mr. Herbert Spencer and the late
Mr. Lewes agree in entertaining very
singular views as to instinct. According
to Mr. Spencer, it is a higher develop-
ment of reason, which it has replaced
owing to the establishment of a more
perfect adjustment of inner relations to
outer relations than exists where mere
reason is concerned. Mr. Lewes regards

BB

0 en ert pe i

370

THE OCAM,

Much below instinct are those activities before referred to as due
to reflex action, and which exist in the cat as well as in ourselves,
but which cannot take place without an mnate power of being im-
pressed and affected by stimuli which are not felt.

Altogether then, THE CAT’s ACTIVE POWERS may be summed up

as follows :—

1. Vegetative powers of growth and reproduction.
2. A power of locomotion and of motion of various parts of the

body.

. A power of being impressed by unfelt stimuli.
. A power of responding to such impressions by appropriate

movements—reflex action.

. A power of responding to felt stimuli by simple actions, plainly
involuntary—eacito-motor action.

ingly voluntary, actions in response to felt stimuli—instinct.
. A power of experiencing pleasure and pain.
. A power of experiencing vivid feelings from material objects —

sensation.

3
+
5
6. A power of blindly performing appropriate complex acts, by seem-
7
8
9

. A power of reproducing by mental images past feelings in a

faint manner.

10. A

power of associating such images with fresh sensations

according to the different relations in which they have co-

existed—sense perception.

11. A power of associating images in groups—imagination.

it as
about by the ‘‘logic of feeling.”’ That
there 7s a logic of feeling—that thereis a
logic in even insentient nature—is not
to be denied ; but that logic is not the
logic of the erystal, not of the brute, but
of their Creator. Dr. Bastian, in his
recent work (The Brain as an Organ of
Mind, p. 221), also endeavours to show
that instinct is not a special faculty.
But all these writers avoid considering
the real difficulties which oppose their
views in either direction. ‘Thus Mr.
Spencer shirks all consideration of the
phenomena which his hypothesis fails
to explain—such as the instincts of the
waxp Sphex and of the carpenter bee.
Dr. Bastian does the same ; contenting
himself by gratuitously asserting as to
ants and ‘bees (/. ¢., p. 235): ‘‘ There
can be little doubt, that if our means of
knowledge were greater than it is, we
should be able to explain these and all
other instincts by reference to the doc-
trines of ‘inherited acquisition’ and
‘natural selection,’ either simply or in
combination.” At the other end of the
mental scale, all the highest phenomena
are also simply ignored by all these
writers alike. Nothing is said by one of

‘lapsed intelligence,”’ brought

them as to our apprehension of Being,
truth, or goodness. The much to be
lamented death of Mr. Lewes cut short
his work abruptly, so that it may be,
had he lived, he would have addressed
himself to the problem ; but it is strange
that neither Mr. Spencer nor Dr. Bastian
should have attempted to grapple with
it. Without so doing, all their con-
clusions may be simply disregarded, as
the phenomena they notice are all beside ©
the main issue they profess to raise. As
to instinct, Dr. Bastian seeks to explain
it by reference to the evolution of con-
tractile hearts, oviducts, and intestines.
But docs he mean to imply that these
contractions were in their first origin
deliberate and voluntary? Was _ the
original ‘‘desire for food ”’ a desire which
a creature deliberately chose to have, or
was it developed by ‘* natural selection,”
those organisms that had no desire for
food becoming extinct? But how could
natural selection ever originate a desire
for food? To what could it have been due
but to an IMPLANTED IMPULSE; and if
such an impulse must be acknowledged at
all, why not acknowledge it with respect
to instinct, the facts as to which so em-
phatically demand its recognition ?

:

CHAP. x1] THE PSYCHOLOGY OF THE CAT. 371

i2..A power of agglutinating and combining imaginations and
sense-perceptions in clusters, and clusters of clusters, so forming
more and more complex imaginations—sensuwous association.

13. A power of memory.

14, A power of so reviving complex imaginations, upon the
occurrence of sensations and images, as to draw practical
consequences—organic inference.

15. Powers leading to spontaneous impulsions in different direc-
tions through internal or external stimuli—appetites.

16. Powers of pleasurable or painful excitement on the occurrence
of sense-perceptions with imaginations—emotions.

17. A power of expressing feelings by sounds or gestures, which
may affect other individuals—emotional language.

18. A power of spontaneous activity in response to sensations or
emotions—organic volition.

§ 3. In the possession of all these varied powers, we and the cat
are similar. But in spite of this resemblance, common sense and
reason assure us that there is a profound difference between the
mind of man and the highest psychical powers of the cat. This
difference is made plain and obvious to our senses by the fact that
we can talk, while neither the cat nor any other beast or bird has
the gift of sPEECH.

It may, perhaps, be objected that it was just before declared that
the cat has language. Now, no mistake can well be greater than
that of confounding together two things essentially different on
account of some superficial resemblance which may exist between
At to call bats, birds, or whaies, fishes, would be error of this

ind.

The cat has a language of sounds and gestures to express its feel-
ings and emotions. So have we. But we have further, what

neither the cat nor any other beast or bird has—a language of

sounds and gestures to express our THoucHTS! I do not refer to
articulate sounds. Rational language can exist without oral speech,
and articulate sounds may be uttered (as by parrots and certain
idiots) though reason be absent. Articulate speech (or the oral
word) is but one mode (though much the most convenient mode) of
making known the far more important and significant thought (or
mental word). It is the Jatter which generates the former, as we

see again and again in each new branch of science or art, wherein
new conceptions having been evolved, new words are coined to give
expression to them. Men do not invent new articulate sounds first,
and attach meanings to them afterwards, but the very reverse.*

* Dr. Bastian, in the work lately | show how the human intellect could
referred to, has a short chapter entitled, | have originated, but even gives up his
“*From Brute to Human Intelligence,” | own contention by speaking (p. 415) of
in which he considers the question of | human languageas having been ‘‘ started
language, with the intention of showing | by some hidden and unknown process of
that there is only a difference of degree | natural development, or as a still more

_ between the mind of man and that of a | occult God-sent gift to man.”
brute. But he not only quite fails to

4

q ;
x3)

BB2

372 THE CAT.

[cHAP. x

Great ambiguity and confusion exist as to LANGUAGE, six kinds of —

which may be distinguished :—

(1) Sounds which are neither articulate nor rational, such as eries
of pain, or the murmur of a mother to her infant.

(2) Sounds which are articulate but not rational, such as the
talk of parrots, or of certain idiots, who will repeat, without
comprehending, every phrase they hear.

(3) Sounds which are rational but not articulate, such as the
inarticulate ejaculations by which we sometimes express
assent to, or dissent from, given propositions.

(4) Sounds which are both rational and articulate, constituting
true ‘‘ speech.”

(5) Gestures which do not answer to rational concepiians, but are
merely the manifestations of emotions and feelings.

(6) Gestures which do answer to rational conceptions, and are
therefore “external,” but not “oral,” manifestations of the
mental word. Such are many of the gestures of deaf mutes,
who, being incapable of articulating words, have invented or
acquired a language of gesture.

§ 4. But that the true nature of the cat- mind may be the better

appreciated, it is desirable to recognize distinctly what are those
HUMAN MENTAL POWERS, of the possession of which by the cat no
evidence exists. They are the following ones :—

(1) A power of apprehending abstract ideas gathered from con-
crete objects, such as the ideas, being, substance, unity, truth,
cause, humanity, ete.—abstraction.

2) A power of apprehending external objects as such, and

recognizing that they exist in truth—intellectual perception.

3) A power of directly perceiving our own existence— self-

consciousness.

4) A power of turning the mind back upon what has been

directly apprehended—reflexion.

) A. power of actively searching for, and so recallimg past
thoughts or experiences—intellectual memory.

6) A power of uniting our intellectual apprehensions into an

explicit affirmation or negation—judgment.

7) A power of combining ideas, and so giving rise to the percep-
tion of new truths thus arrived at—intellectual synthesis and
induction. :

(8) A power of mentally dissecting ideas, and so gaining other
new truths, and also of apprehending truths as necessarily
involved in judgments previously made—intellectual analysis,
deduction and ratiocination.

(9) A power of apprehending some truths as absolutely, positively
and universally necessary—intellectual intwition.

(10) Powers of pleasurable or painful excitement on the ocecur-
rence of intellectual apprehensions—hAigher, or intellectual
emotions. 4

(11) A power of giving expression to our ideas by exten bodily

signs—rational language.

(
(
(
(5
(
(

‘CHAP. XI.]

THE PSYCHOLOGY OF THE CAT. 373

(12) A power of, on certain occasions, deliberately electing to act
(or to abstam from acting) either with, or in opposition to,
the resultant of involuntary attractions and repulsions—wil/.

| Now all the actions performed by the cat—all of which may be
grouped under one or other of the eighteen groups of the former * list
of faculties—are such as may be understood to take place without
deliberation or self-consciousness. Jor such action it 1s necessary,
indeed, that the animal should sensibly cognize external things, but
it is not necessary that it should intellectually perceive their being ;
that it should feel itself existing, but not recognize that existence ;
that it should feel relations between objects, but not that it should
apprehend them as relations; that it should remember, but not
intentionally seek to recollect; that it should feel and express
emotions, but not itself advert to them; that it should seek the
pleasurable, but not that it should make the pleasurable its deliberate
alm.

In fact, all the mental phenomena displayed by the cat, are
capable of explanation by the former list of psychical powers, with-
out the aid of any one of those enumerated in the above catalogue
of truly rational faculties,+ nor could any of the former by any mere

* Jn the second section of this chapter,

. 370.
P + Asafriend of mine, Professor Clarke,
has put it :—‘‘In ourselves sensations
presently set the intellect to work ; but
to suppose that they do so in the dog is
to beg the question that the dog has an
intellect. A cat to bestiritself to obtain
its scraps after dinner, need not enter-
tain any belief that the clattering of
plates when they are washed is usually
accompanied by the presence of food for
it, and that to secure its share it must
inake certain movements; for quite
independently of such belief, and by
virtue of mere association, the simple
objective conjunction of the previous
sounds, movements, and consequent
sensations of taste, would suffice to set
up the same movements on the present
occasion.” Let certain sensations and
movements become associated, and then
the former need not be noted : they only
need to exist for the association to pro-
duce its effects, and stimulate appre-
hension, deliberation, inference, and
volition. ‘‘ When the circumstances of
any present case differ from those of any
past experience, but imperfectly resemble
those of many past experiences, parts of
these, and consequent actions, are irregu-
larly suggested by the laws of resem-
blance, until some action is hit on which
relieves pain or gives pleasure. For
instance... . let a dog be Jost by his

- Mistress in a field in which he has never

been before. The presence of the group
of sensations which we know to in-
dicate his mistress is associated with
pleasure, and its absence with pain. By
past experience an association has been
formed between this feeling of pain and
such movements of the head as tend to
recover some part of that group, its
recovery being again associated with
movements which, de facto, diminish the
distance between the dog and his mis-
tress. The dog, therefore, pricks up his
ears, raises his head and looks round.
His mistress is nowhere to be seen ; but
at the corner of the field there is visible
a gate at the end of a lane which re-
s mbles a lane in which she has been
used to walk. A phantasm (or image) of
that other lane, and of his mistress walk-
ing there, presents itself to the imagina-
tion of the dog ; he runs to the present
lane, but on getting into it she is not
there. From the lane, however, he can
see a tree at the other side of which she
was wont to sit; the same process is
repeated, but she is not to be found.
Having arrived at the tree, he thence
finds his way home.” By the action of
such feelings, imaginations, and associa-
tions—which we know to be vere causce
—I believe all the apparently intelligent
actions of animals may be explained
without the need of calling in the help
of a power, the existence of which is in-
consistent with the mass, as a whole, of
the phenomena they exhibit.

:
:
:
t

374 THE OAT. rome

increase of intensity, change into one of the latter, for they differ
not in degree, but in kind. |

Into this question, however, it 1s not desirable, for the object of
this work, further to enter. It is the less necessary so to do,
because the subject has been treated at length in a book which may
be regarded as introductory to the Author’s present work. I refer
to “ Lessons from Nature as manifested in Mind and Matter,” and -
especially to its 4th, dth, 6th, and 7th chapters, in which the dis-
tinctions of kind which exist between the mental powers of man and
the analogous powers of brutes are considered in detail.

§ 5. Such then, in the judgment of the present writer, are the
most significant facts and the most important deductions with respect —
to the cat’s psychology in the commonly used meaning of that
word. But, as has been here observed more than once, the term
‘“‘ Psychology ”? has and should have a much wider meaning, and
embrace all the vital activities, of whatsoever kind, of which any
animal is capable.

These activities are of very different orders. Some of them are
manifestly (like those of locomotion) activities of the entire creature.
Others (like the activities of digestion or respiration) involve a large
portion of the animal’s body ; while others again (such as those which ~
result in the formation of a nerve-cell or a blood-corpuscle) are
activities which are confined to only very minute portions of its
frame.

Yet the whole of these activities must proceed harmoniously, or
the animal could not continue to live in health and strength. Its
body is obviously a unity. The activities of that body are in some
way CO-ORDINATED and UNIFIED also. To understand this fully, is
truly to understand Psychology.

§ 6. In the foregoing chapters we have considered both the several
parts of which the cat’s body is made up, and also the functions which
they severally and collectively perform. We have also noted the
successive modifications and transformations which take place during
development—zi.e., those series of forms which are assumed by the
developing animal, between the condition of the unimpregnated ovum
and that of the adult cat.

We have seen (1) in the first place that the cat’s body is made
up of a collection of “systems” of organs, such as the nervous
system, the muscular system, and the alimentary, circulating,
respiratory, and generative systems ; (2) secondly, we-have seen that
each such system is made up of a number of “organs,” which act
together in harmony. Thus we have seen, e.g., that the nervous
system consists of a brain, a spinal cord, sympathetic ganglia, and
various sets of nerves, some of these nerves energizing by the help
of special parts, called ‘ sense-organs ’’—the functions of the whole
being some form of sensitivity. Again, the alimentary system we
have seen to consist of a mouth with jaws, tongue and teeth, of an
cesophagus, a stomach and an intestine with accessory glandular
structures—the function of the whole being to minister to a/imenta-

“J
Hi
‘

omar. x1] THE PSYCHOLOGY OF THE CAT. 375

tion. ‘So also we have seen that the cat’s circulating, respiratory,
and generative systems of parts, have each their special function,
in the performance of which their various constituent organs har-
moniously concur. (3) Thirdly, we have seen that each “organ” is
made up of a greater or less number of “ tissues,” which together
enble it to perform that function for which it is destined. Thus
the stomach consists of a basis of fibrous tissue, with much muscular
tissue, and is coated internally with epithelium, which, descending
into superficial depressions lines the various glands which open upon
its surface. It is also richly supplied with vessels and nerves. Its
fibrous tissue maintains its shape and gives it the strength requisite
for its continued existence. Its muscular tissue is the source of its
motor power, without which it could not physically act, and its
epithelial lining, endowed with its secreting properties, is the source
of its digestive power, without which it could not act chemically on
the food contained within it. Its vascular structure affords the
nutriment which its several parts need to repair the waste of its
continued action (which action, without this supply, would soon
come to an end), and its nervous tissue, with its property of ‘‘im-
pressionability,”’ is the regulating agent which adjusts the actions of
the other tissues and of the entire viscus as one whole. (4) Fourth ~
and lastly, we have seen that each separate tissue 1s composed of its
own ultimate parts—different in each tissue, but which may, in all
cases, be said to consist of a matrix—fluid or solid, fibrous or homo-
geneous—with torpuscles, which are cells modified in one or another
mode. We have also seen that each tissue is at first cellular, and
is derived in one or another way from two layers of cells—epiblast
and hypoblast—themselves the product of the spontaneous divisions
of the germ-cell. Each of these cells, therefore, possesses, for a
longer or shorter time, its own activity and plays its own part in
contributing to the general property of that tissue of which it forms
a minute portion. ‘Thus we have:

(a.) Cell activities, contributing to that special vital property which
is characteristic of each tissue.

(b.) Tissue activities, contributing to that special function which is
characteristic of each organ.

(c.) Organ activities, contributing to that more complex function
which is characteristic of each system of organs, viewed as one
complex whole.

(d.) System activities, consisting of the combined activities of sets,
or systems, of organs, and contributing to a higher and yet more
complex function.

§ ‘7. For just as cell activities are subsumed by that of the tissue
they compose, and as the vital properties of tissues are synthesized
into a higher unity by the organ of which they form a part, and as
the functions of organs are embraced by the higher function of that
system of parts of which such organs are members, so are the fune-
tions of all the systems of organs subsumed and synthesized into a
yet Ingher unity, which is the life of the animal itself, and which

376

THE CAT,

life is the function of its body considered as one whole, just as the
subordinate functions are those of that body’s several sets of organs.
That the living cat is one creature in feeling and action, as well
as that its body is one—ice. , that Hi asia unity dynamically as well
as statically—is what common sense and reason unite to assure us.
These suffice to convince us that the plaintive cries of its victim, the -
sight of its struggling form, and the taste of its blood, may be all

simultaneously felt by the same cat.

More than this: such sensa-

tions call up more or less distinct reminiscences of similar feelings
before experienced, and give rise to vivid emotions and appropriate
actions, so that past and present sensations, of very varied kinds, are
united with different emotions and appropriate actions in one existing

psychical activity.

Such an animal then is really the theatre of

some unifying power which synthesizes its varied activities, dominates

its forces, and is a PRINCIPLE OF INDIVIDUATION.

There would seem

to be here present, a vital force or principle, which has no organ
except that of the entire body within which it resides, and the
activities of which reveal that principle’s existence, just as the con-
tractions of muscular tissue make known to us its intrinsic, and
otherwise imperceptible, power of contractility.

§ 8. But it may be thought that in the nervous system we have

the organ and vehicle of such unifying activity.

Undoubtedly the

nervous system is, as before said, the great regulator of the body’s

activities.
to the actions of other systems.

But its own action requires regulation, and to be adjusted
It cannot, however, regulate itself!

Moreover, all the vital activities needed for growth, sustentation,
and reproduction, may exist in the greatest abundance without any
trace of a nervous system, as in the great world of plants—some of
which, such as the well-known sun-dew (Drosera) and Venus’s fly-trap

(Dionea), very curiously simulate the actions of animals.

In such

plants we evidentiy have susceptibilities to impressions of a complex
kind; for impressions made by objects, such as insects, are followed
by singularly appropriate actions on the part of the plants to secure
and digest their living prey. Very curious too are those movements
by which the roots of some plants seek moisture as if by instinet,* or
those by which the tendrils of certain climbers appear to search
for some fitting support, and, having found it, to cling to 1t by what

resembles a voluntary clasping. if

* My friend Professor Paley, tells me
that in 1863 at Penn, near Wolver-
hampton, a sycamore tree of consider-
able size was found to have sent down
into a well, to reach the water, a root
forty-four feet long, and about a quarter
of an inch in diameter throughout. <A
mass of roots had wrapped themselves
round the uyper part of the well and
nearly stopped it up. The Rev. F. H.
Paley (formerly vicar of Penn, and now
vicar of Church Preen, Shrewsbury) has
confirmed the truth of this statement.

Still more remarkable is the way

+ These tendrils oscillate till they
touch an object, which they then em-
brace. The tendril of a passion-flower
may sometimes: be made to bend by the
pressure on it of a thread weighing no
more than the thirty-second part of a
grain, or by merely \touching it for a
time with a twig. If, however, the twig
be taken away again at once, the tendril
will then soon straighten ‘itself, Yet
neither the contact of other tendrils of
the same plant or the fall of raindrops
will produce such bendings.

ite PSYCHOLOGY OR THE CAT, 377.

in which the little creeping plant, the “mother of a thousand ”
(Linaria), explores the surface of a wall to find an appropriate
hollow for her progeny, which hollow being found, her capsule is
plunged in it, and its seedis there discharged. Here, therefore, there
a co ordination of actions for the benefit of the whole organism, and
yet in no plant is there a trace of a nervous system.

§ 9. The existence in each animal of an internal principle of
individuation and co-ordination is indicated by various ANATOMICAL
AND PATHOLOGICAL FAcTs. We have seen the bilateral and serial
symmetry which exists in the cat’s body and limbs. Relations of
symmetry of similar kinds show themselves also in abnormal and
diseased conditions. Sir James Paget,* im treating of symmetrical
diseases, mentions a lion’s pelvis which was marked, through a sort
of rheumatic affection, by a pattern more complex and irregular
than the spots upon a map, yet so symmetrically disposed that
all spots or lines on one side of the pelvis were exactly repeated by
those on the other side. He also observes that diseases very often
affect simultaneously such homologous parts as the backs of the
hands and fect, the palms of the hands and the soles of the feet,
the elbows and knees, and the corresponding parts of the upper arms
and thighs.

As to monstrosities, M. Isidore Geoffroy St. Hilaire remarks: *
“V’anomalie se répéte d’un membre thoracique au membre ab-
dominal du méme cété,”’ and quotes a case in which certain corre-
sponding parts of the carpus and tarsus, the metacarpus and
metatarsus and of the digits, were simultaneously absent.

Professor Burt G. Wilder has recorded t no less than twenty-
four cases where such excess co-existed as regards both little fingers;
six 1a which both little fingers and toes were similarly affected, and
twenty-two cases more or less the same, but in which the details
were not accurately to be obtained.

Perhaps, however, the most curious and instructive cases are
those presented by some of our domestic birds. In trumpeter
pigeons, and some bantams, the feet, which are usually naked,
become abnormally feathered, and these feathers may even exceed in
length those of the wings. They are also developed from that side
of the foot which corresponds with the feather-bearing side of the
hand. Moreover, in ordinary pigeons, though the digits of the
hand are completely united together, the toes of the foot are free.
In these abnormal pigeons, however, the outer toes become more or
less united together by skin like the fingers.

Facts such as these, seem to make evident the existence in each
animal, which as a whole is a visible unity, of an innate polar force
tending to carry out development in definite directions, but liable to
haye its effects modified by the action of surrounding circumstances.

* Lectures on Surgical Pathology, | p. 228. Bruxelles, 1837.
1853, vol. i., p. 18. + Massachusetts Medical -Society,
t Hist. Générale des Anomalies, t. i, | vol. ii, No. 3, June 2, 1868.

378 THE: Oar [CHAP. XI.)
All such animals however, as those just mentioned, have a well oy
developed nervous system; but there are other animals in which
symmetry of form is carried to the highest degree, while yet no
trace of a nervous system is to be detected mm them. q
Such creatures are the Radiolarians—minute marine organisms of!

h
“4, , RA

Fig. 163.—DORATASPIS POLYANASTRA. ADULI

almost the simplest structure as regards their soft substance, but
which have siliceous skeletons of extreme complexity and beauty,
and, at the same time, of marvellous symmetry. | |

§ 10. In such an animal as the cat, then, we have indeed evidence
of a principle of individuation ; for im it we have not only symmetry
of organization and harmonious organic action (as in the lowly
organized creatures just referred to), but also sense perceptions,
| which meet in a central sensitive faculty able to discriminate the
| odorous from the coloured and the sapid from the audible.

Not that there is any reason to think that the cat can appreciate
the odours, &c., as such, but only that it is practically impressed by
the relations and distinctions between its own sensations as well as
between the objects which elicit them. It has, in ‘fact, not con-
sciousness but ‘‘ CONSENTIENCE.”’

§ 11. But, as we have seen, its nervous system ministers to a
vast number of actions which are unfelt as well as to its felt actions,
while its life is also made up of actions which the nervous system

if!

ees
»

cuay. x.] THE PSYCHOLOGY OF THE CAT. 379

eannot control. Such are the actions within the nervous system
itself, and the changes which take place in the ultimate substance
of the other tissues beyond the reach of the finest vessels or the
most delicate nerves.

Some actions (such as those above referred to) we know, by our
own experience, are “felt” actions—the “ subjective” and im-
material phenomenon taking place simultancously with the bodily
change, But no physiologist can deny but that other nerve actions,

y AM

i |

Fig. 164.—DOoRATASPIS POLYANASTRA, YOUNG. SHOWING ITS MULTIPOLAR MopDE or GROwTU.
THE SPHERICAL SHELLS ARE FORMED BY OUTGROWTHS, WHiCH SPRING FROM TUE
RADIATING PARTS AT SIMILAR DISTANCES FROM THE CENTRE OF THE SHED. THE

LATERAL EXTENSIONS FROM THE RADII MEETING TO FORM A SPHERE BY THEIR
JUNCTIONS.

\

which are not felt, may have their quasi-subjective or immaterial
sides also. More than this: to be rational, we must admit that every
action of any animal really has its quasi-subjective or immaterial side.
Mr. Bain has said,* “1t would be incompatible with everything
we know of cerebral action, to suppose that the physical chain [ of
phenomena] ends abruptly in a physical void, occupied by an im-
material substance; which immaterial substance, after working
alone, imparts its results to the other edge of the physical break,
and determines the active response—two shores of the material, with
an intervening ocean of the immaterial.’”’ This is good as far as
it goes, but the converse is at the least as inconceivable—namely, a
break in the immaterial chain, bridged over by the intervention of
a physical substance. Moreover, what Bain here affirms with respect
to the brain and its activity, must, by any logical pyschologist, be
also affirmed with respect to every entire living organism and its
activity. We find in each organism a chain of physical phenomena

* Mind and Body, p. 13.

380 | THE CAR (CHAP, XI
accompanied by a chain of immaterial energies, some part of which
we know in ourselves as conscious feeling and thought; but the rest
of which, in ourselves, and in all other living creatures, we can
only know by rational inference. The chain of physical phenomena
consists of the actions of that side of the one living whole, which we
eall its visible body. The chain of immaterial energies consists of
the actions of that side of the one living whole which is its principle
of individuation, its “psyche,” or “ soul.”

§ 12. The word “soun”’ must not be understood to denote that
which it has been, in modern times, commonly used to express. By
it is not meant a substance numerically distinct from the animal’s
body, and which may be conceived as capable of surviving the des-
truction of the latter *—a conception which is unphilosophical as
well as unscientific.

We have seen that structure and function ever vary together, just
as the convexities and concavities of the same curved line do and
must vary together. In the same way the “ principle of individua-
tion,” or “soul,” of any animal (and of any plant either), and its
material organisation, of which that soul is the ‘ function,” must
necessarily arise, vary, and be destroyed simultaneously, unless some
special character, as in the case of man, leads us to consider it ex-
ceptional in nature. The word “soul,” then, as here used, and as
used by Aristotle and his followers, does not denote a separate entity
which inhabits the body—an extra-organic force within the living
creature, and acting by and through it, but numerically distinct from
it. It denotes that which as considered apart from the body is but
a mental abstraction, but which, considered as one with the body,
exists most truly and really as an inseparable part of one mdivisible
whole—the living body. It and the body are one, as the impress on
stamped wax and the wax itself are one, though we can ideally dis-
tinguish between the two. Our common sense assures us of that which
science and philosophy confirm, namely, that a living animal is not
a piece of complex matter played on by physical forces from without,
which transform themselves in passing through it; but is the ex-
pression of a peculiar immanent principle (whensoever and however
arising), which for a time manifests its existence by the activities ot
the body with which it is so entirely one that it may much more
truly be said to be the animal than the lump of matter which we can
see and handle can be said to be such animal.

Thus the real, substantial constituent essence of the animal we are
studying—as of every other animal—is not what we see with our
eyes; it is something which ever escapes our senses, though its
existence and nature reveal themselves to our intellect. Jt neces-
sarily escapes our senses, because these senses can detect nothing in

* Even in man, there is no adequate | exalted, though there is good evidence
reason for believing in the existence of | of a philosophical kind that in his case
any principle of individuation, save that | that principle does survive the dissolu-
which exerts its energy in all his func- | tion of the body.
tions, the humblest as well as the most

ioe mera

omar. xt] THE PSYCHOLOGY OF THE CAT 381
an animal or plant beyond the sensible qualities of its material com-
ponent parts. But neither is the function of an organ to be de-
tected save in and by the actions of such organ, and yet we do not
deny it its function or consider that function to be a mere blending
and mixture of the properties of the tissues which compose it.
Similarly it would seem to be unreasonable to deny the existence of
a living principle of individuation because we can neither see nor
feel it, but only infer it. This power or polar force, which is im-
manent in each living body, or rather which is that body living, is
of course unimaginable by us, since we cannot by imagination
transcend experience, and since we have no experience of this force,
save as a body living and acting in definite ways.

§ 13. It may be objected that its existence cannot be verified.
But what is verification ? We otten hear of “ verification by sensa-
tion,”’ and yet even in such verification the ultimate appeal is not
really to the senses, but to the intellect, which may doubt and which
criticises and judges the actions and suggestions of the senses and
imagination. Though no knowledge is possible for us which is not
genetically traceable to sensation, yet the ground of all our de-
veloped knowledge is not sensational, but intellectual, and its final
justification depends, and must depend, not on “feelings,” but on
“thoughts.” ‘Certainty ” does not exist at all in feelings any more
than doubt. Both belong to thought only. ‘ Feelings” are but the
materials of certainty, and though we can be perfectly certain about
our feelings, that certainty belongs to thought and to thought only.
“Thought,” therefore, is our absolute criterion. It is by self-
conscious thought only that we know we have any feelings at all.
Without thought, indeed, we might feel, but we could not know
that we felt or know ourselves as feeling. If then we have ational
grounds for recognizing the existence of this “ soul ”—and its exist-
ence is made known to us by its acts, and is verified by our reason—
then, the poverty of our powers of imagination should be no bar to
its recognition. We are continually employing terms and con-
ceptions—such, ¢.g., as ‘‘ being,” ‘ substance,” “ cause,”’ &e.—which
are intelligible to the intellect (since they can be discussed), though
they transcend the powers of the imagination to picture.

On all sides things made known to us by sense (sensibles), serve to
elicit conceptions of things which can be apprehended by the intellect
(intelligibles), but can never be themselves directly perceived by the
senses. As they cannot be so perceived, they can never be imagined,
but can only be symbolically expressed by words or other signs.
Such signs must always be inadequate to express what they are
intended to symbolise, because we can use no signs which are not
transcripts of sense, while what they are intended to symbolise,
is, as we have seen, beyond sense. Such symbols, therefore, are
necessarily open to the cavils of any one who professes not to have
the ideas they serve to express, and who asks for sense-impressions
absolutely equivalent to such ideas; since none such can there be.
But no objection can hence be drawn against the conception of the

382 THE OAT. eG

*€animal soul,”’ which is not equally valid against all those concep-
tions, ‘ cause,” “ being,” “ substance,” &e., without the acceptance
of which, our intellectual activity must come to an end altogether.

This principle of individuation, then, this soul, or wvyx7, animates
the whole body, and presides over a// its actions; which are, indeed,
its actions, the body, as a whole, beg its “ organ”—the function
of such ‘‘ organ”’ being the “soul’s action” or “life.” Not to admit
this is to be driven to the absurdity of conceiving the living body to
be made up of an indefinite quantity of minute independent
organisms, without subordination or co-ordination, each with its own
principle of individuation, its own soul.* This conception, indeed,
but multiplies difficulties, since the same arguments can be brought
against each of these souls, or against the one soul, while to affirm
their existence and deny functional unity, is to contradict the direct
evidence of our senses as regards other organisms, and even the
evidence of consciousness itself as regards our own; for each man’s
own feelings and perceptions declare to him that he is one whole—
a living unity im multiplicity.

§ 14. But some writers who fully recognize the fact of the two co-
existing cycles of animal life (the physical and the immaterial) have
regarded the latter (the immaterial) as the mere effect of the former
(the physical), and have denied to the feelings of animals, or to the
thoughts of men, any power to act as causes in the events of lfe—
both animals and men being regarded as mere automata. But the
notion that an animal is real/y a machine is an absurdity; for a
machine is a complex structure, the actions of which are fully to
be accounted for by the physical properties of its component parts
and the action of merely physical forees—without the intervention
of sensation, or of any influences like those which mduce nutrition
and reproduction in living creatures. <A clock, to be really compar-
able with an animal, must be capable of winding itself up, gathering
oil to replace that which is used up in its movements, repairing any
trifling injuries which may result from the friction of its wheels,
and finally, of giving forth from time to time miniature reproductions
of itself destined ultimately to attain the size of the parent timepiece.

Now an animal such as the cat, is a complex structure which
really has all these powers, and its parts are, as we have seen, so
mutually adjusted to serve one another, that 1t may be said to be a
mechanism the parts of which are reciprocally ends and means.
The nervous system ministers to the circulation, the circulation to
the nervous system, and both these to the alimentary system which
nourishes them again; and so on throughout the whole complex
collection of apparatus which make up the cat’s body.

But that body is one which, like a machine, does act mechanically
and necessarily, because its actions are necessarily determined by the
adjustments of its various parts. Yet its actions do not take place
without sensations, and these sensations are not the mere accom-

* As has been affirmed by Professor Haeckel.

ile — “st
cP. ae ,
Sipe ie
ie ;
e+:

cuar. xn] THE PSYCHOLOGY OF THE CAT 383

paniments of bodily actions, but are themselves guides and directing
agencies which intervene and operate upon, though they do not
break through, the circle of its bodily actions. The feeling of the
blow of a stick, or the sight of a threatened blow, will change the
course of action which a cat would otherwise have pursued. That it
is the feeling or the sight of the stick, together with the various
passed feelings or imaginations which such fresh experience calls up,
which causes the change, will be disputed by no one who has not
some eccentric thesis to maintain.

But the movements of the animal are also determined (like our
own) by a multitude of organic influences which are not felt, though
they operate through the nervous system (being thus parallel with
those which are felt) and form part of the immaterial chain which
accompanies the chain of physical modifications which take place
during its life. Thus, again, we see that the animal is a creature of
activities which are partly physical and material, partly psychical
and immaterial, of which the latter—both the felt and the unfelt—
are directive, though they are in turn influenced by physical modifi-
. cations. We may compare this reciprocal influence to the altera-

tions in the shape of a ring formed of two inseparably united metals

which contract unequally at the same temperatures—alterations

in either constituent affecting the compound whole, and therefore
affecting the other constituent also.

The notion that an animal is a mere automaton in which the
physical action alone enters into the chain of causation, has been
supported by comparing its psychical activities to mere collateral
products of the working of a machine, such as the sound of the
steam engine’s whistle. Against this, Mr. Lewes has urged* as
follows: ‘“‘The feeling which accompanies or follows a particular
movement cannot, indeed, modify that movement, since that is
already set a going, or has passed; but the analogy fails in the
subsequent history: no movements whatever of the steam engine
are modified by the whistle which accompanies the working of that
engine; yet how the reflected influence modifies the working of the
organism! Ifthe hand be passing over a surface, there is, accom-
panying this movement, a succession of muscular and tactile feelings
which may be said to be collateral products. But the feeling which
accompanies one muscular contraction 7s itself the stimulus of the
next contraction ; if anywhere during the passage the hand comes
on the surface which is wet, or rough, the change in feeling thus
‘produced, although a collateral product of the movement, instantly
changes the direction of the hand, suspends or alters its course—that
is to say, the collateral product of one movement becomes a directing
factor in the succeeding movement.” This is what no automaton could
effect. Sensation is of the essence of the process, and is evidently
a “* cause.”

What light is thrown upon this subject by our own knowledge of

* Physical Basis of Mind, p. 407.

; :
se .
ed
‘

384 ; THE OAT. ~

ourselves? We know that in our own actions sensations enter as
causes as well as accompaniments of our activity, and not only this,
for we know further that our thoughts may also enter into the same
circle of our life changes. We know that it is our knowledge that a
certain event is imminent (¢.g., that a storm is fast approaching)
which makes us act in a certain way (¢.y., to stop in_a walk
and begin to return towards home) in anticipation of it. To deny
this is to deny the evident teaching of our consciousness-—it is to
deny what is most evident in favour of what is much less so—some
speculative hypothesis. Let us suppose that some one tells us when
away from home that our house is on fire, who does not know that
the actions he thereupon performs are due to his mental apprehen-
sion of the news told him? If we do not know such a thing as this
we know nothing, and discussion is useless. As the late Mr. Lewes
has said,* “That we are conscious, and that our actions are de-
termined by sensations, emotions, and ideas, are facts which may or
may not be explained by reference to material conditions, but which
no material explanation can render more certain.” The advocate of
“Natural Selection’ may also be asked, ‘‘ How did knowledge ever
come to be, if it is in no way useful to its possessor, if it is utterly
without action, and is but a superfluous accompaniment of physical
changes which would go on as well without it?”

§ 15. But let us learn a little more from our own experience of
our own nature. We know that a whole multitude of actions,
which are at first performed with attention and full consciousness,
come at last to be performed unconsciously ; we know that effective
impressions may be made on our organs of sense without our know-
ledge—our attention at the time of the occurrence being diverted.
We know also that countless organic activities take place im us under
the influence and control of the nervous system, which either never
rise into consciousness at all, or only do so under abnormal con-
ditions. Yet we cannot but think that those activities are of the
same generic nature, whether we feel, perceive, or attend to them or
not. ‘The principle of individuation in ourselves, then, evidently
acts with intelligence in some actions, with sentience in many
actions, but constantly in an unperceived and unfelt manner. Yet
we have seen that it undeniably intervenes in the chain of physical
causation.

The principle of individuation in the cat is a principle which
subsumes into a higher unity, which unifies and directs the active

properties of all the cells and tissues, and the functions of all the
organs and system of organs which make up the animal’s corporeal
frame. Its activities are: (1) mainly unfelt and occupied with the
simplest vital processes of the organism. Amongst these there is
much organic discrimination, and that automatic memory of the
organism which, is, as it were, the basis of that felt memory which
intervenes in the animal’s mental activity ; (2) They are those

“ See Physical Basis of Mind, p. 383,

e
te

‘CHAP, XI] THE PSYCHOLOGY OF THE CAT. 385
various feelings and emotions which make up its mental powers.
Common sense is right, then, when it says “‘ the cat sees, the cat hears,
the cat feels, the cat runs, plays, hunts,” &c. ; for it is the whole living
organism which does all these things, and not merely its brain,
muscles, or any portion of that inseparable unity of which it consists.
Moreover, it is the invisible, immaterial entity which ever escapes
our senses but which is visible to our reason, which is more truly and
emphatically THE cAT ITSELF, than is the matter of which it is com-
posed. ‘The energy, direction, and control belong to it, and without
it the cat is not. The dead body of the cat we may anatomise at
will, but the animal itse/f being dead has no existence, any more
than a “‘ corpse’’ is a “dead man.”

The dead body of a man is a perfectly correct expression, but to

speak of a dead man, a dead cat, or a dead bird, though, of course,
fully permissible in popular speech, is really and philosophically to use
an expression as self-contradictory as it would be to say a ‘‘ dead
living creature.”
- §16. The difficulty which some readers may possibly feel in
conceiving the real existence of a distinct and substantial but (in
itself ) immaterial entity subsisting indivisibly as an innate principle
in every living organism, is due rather to the prejudice induced by
a popular tendency than to any reason which can be logically urged
against it. ‘‘ Sensationalism ” is the vice of the day which tends to
degrade our art and literature as well as our science. We see it
welcomed on the stage by crowds of sympathetic auditors, and this
craving of our lower impulses is copiously fed by the less scrupulous -
of our novelists. |

Although it is the special dignity and prerogative of man, amongst
animals, to apprehend the abstract and ideal, his tendency too often
is to repose in what is at once concrete and material. In the
field of speculation, we recognize this materialistic tendency in
those who refuse to recognize intellectual truths which cannot be
verified by sense, and who forget that reason, not sense, 1s our
ultimate criterion, and that it is the office of reason to criticise, and
accept or reject the apparent testimony of the senses.

Reaction from this irrational tendency has given rise, and gives
rise, to a directly opposite conception. Thinkers who see clearly
how often the essential nature of each object is misunderstood
because it is sought for only in matter, loudly proclaim that the
essence of everything is an ‘idea,’ and thus, in seeking to escape
from materialism, fall into the error of idealism.

Scientific truth, it is here contended, lies between these two
opposite errors. It recognizes, with the first school, that the essences
of living organism are not ideas but substantial realities. It also
recognizes, with the second school, that such realities are not mere
agglomerations of matter, but are the expression of an immaterial
principle. It recognizes, in a word, that the dominant constituent
of every living organic being is neither material nor ideal, but an
IMMATERIAL REALITY which the reason can apprehend and recog-

nize as necessarily present, but which the imagination can never
: aoc

j

,
]
’

an ee om eon, elias

386 THE CAT,

(CHAP. XI

picture, for the simple reason that no reality of the kind can, from
its very nature, be the object of sensible experience.

Such an immaterial reality is that indivisible, active principle or
individual force, which was called Psyche by Aristotle, and which
we may call “ soul” or ‘ furm,” in the sense of an individual living
principle, absolutely one with the body it informs.

§ 17. In order to make clearer what has been pointed out, it
may be well to define more distinctly certain terms.

The psyche or soul, then, is that principle of individuation which
makes the animal what it is, though it has no actual existence apart
from the matter it vivifies. Yet it is the animal par excellence, the
matter of which it is composed being but the subordinate part of
that compound but indissoluble unity—the living animal.

The action of the psyche includes every vital action of the
organism of whatsoever kind, each and every such action being a
** nsychosis””’ of one kind or another.

The specially animal activity of the organism—animal psychosis—
is the sum of all those activities to which the nervous system minis-
ters. Every such activity—every activity of living, neural matter—
is a neural psychosis, and ends in a feeling, a secretion or a motion.
Neural psychosis then may be either felt or unfelt, and amongst the
felt actions of the kind, are all sensations, memories, imaginations,
emotions and felt impulses tending to result in action, and those
practical inferences before referred to. The sum of felt, neural
psychoses in the cat, is the so-called ‘ cat-mind” or synesthesis, and
every felt neural psychosis is a synesthetic or so-called “‘mental” act.*
The remaining, or vegetative activities of the organism—vegetal
psychosis—is the sum of all those activities which result in nutrition

and generation—the maintenance of the individual organism and

the reproduction of new individuals. This form of psychosis exists
by itself in plants, but in the animal organism is most intimately
united with animal psychosis. It is so because, as we have seen in
the cat, the nervous system ministers to nutrition and to repro-
duction as well as to feeling and to motion. The animal and
vegetal psychoses are thus intimately united because the cat, being a
true unity, can have but one principle of individuation—or psyche—
which must therefore be the agent of all the vegetative as well as
of all the animal psychoses which take place in it,

§ 18. Such being the principle of individuation as made known
to us in the adult animal, what are we to say of it in the earlier
stages of the cat’s existence ?

* The terms ‘‘mind”’ and ‘ mental
act’ are not, of course, properly applic-
able to the felt neural psychosis of the
cat or of any unrational animal. They
are here merely employed analogically
in deference to popular usage.

The ‘‘ mind” properly denotes the phe-
nomena of our consciousness—the rational
soul energizing both corporeally and con-
sciously. Such action cannot take place

without the aid of neural psychosis to
furnish the images or phantasmata need-
ful for all human mental action; but
though so aided, the action itself is
purely immaterial. The sum-total of
the mental action of a rational animal
may be called its noesis, which will be
the analogue of the synesthesis or sum-
total of the felt neural psychoses of an
irrational animal, ih

‘

“4

CHAP. XI.] THE PSYCHOLOGY OF THE CAT. 387

This question cannot be duly considered without recognizing that
though living creatures have principles of individuation of the most
varied kinds, yet that they are susceptible of being classed in two
groups—animals and plants.

AS we descend to the lowest animals, the evidence as to senti-
ence diminishes; while (from the resemblances of the lowest
animals and plants, and from the similarity of the vegetative
functions in all living creatures) we may analogically conclude that
activities take place in plants which are parallel with, and analogous
to the unfelt and non-neural psychoses of animals. As Asa Gray
has said with respect to their movements: “ Although these are
incited by physical agents (just as analogous kinds of movements
are in animals), and cannot be the result of anything like volition,
yet nearly all of them are inexplicable on mechanical principles.
Some of them at least are spontaneous motions of the plant or
organism itself, due to some inherent power which is merely put in
action by light, attraction, or other external influences.”’

Reference has already been made to insectivorous plants, such as
Dionea. In such plants we have susceptibilities strangely like those
of animals. An impression is made, and appropriate resulting
actions ensue. Moreover, these actions do not take place without
the occurrence of electrical changes similar to those which occur in
muscular contraction.

Nevertheless, nothing in the shape of vegetable nervous or mus-
cular tissue has been detected, and as structure and function neces-
sarily vary together, it is impossible to attribute sensations, sense-
perceptions, instincts, or voluntary motions to plants, though the
principle of individuation in each plant acts (in its degree) as do
the unfelt psychoses of animals, and harmonises its various vital
processes.

The conception then which commended itself to the clear (and
certainly unbiassed) Greek intellect of more than 2000 years ago,
that there are three orders of internal organic forces, or principles

of individuation, namely, the rational, the animal, and the vegetal,
appears to be justified by the light of the science of our own day.

We have no grounds for believing in the potential existence of
sensation in plants, inasmuch as in the highest plants it is not made
manifest, and no traces of sense organs have anywhere been found
in them. Man apart—there are two orders of internal organic
forces or principles of individuation—there is the animal, there is |
the vegetal, soul or psyche.

Now we have seen that the cat begins its existence as a minute
spheroidal mass of protoplasm, which is capable of spontaneous
division and which can imbibe nutriment and grow. It is comparable
with a lowly organized plant. As function varies with structure
we cannot deny a vegetal psyche to the creature at this stage of its
existence, though we have no grounds for attributing to it as yet a
really animal nature. But growth continues and produces a com-
plexity of structure which demands a principle of individuation of «

cc2

388 THE CAT. (CHAP, XI.
higher order. Slowly the blastoderm is developed—the epiblast
becomes furrowed, and the developing matter grows here and there
into nervous and muscular tissue. We have then the organs of true
animal life, and we are therefore compelléd to conclude that, in a
way which defies our powers of observation to detect, that vegetal
principle which at first acted has disappeared to give place to a
truly animal psyche. But the embryo 1s, as yet, no cat, neither is
it like any other perfect animal. At first it is somewhat like a
worm, but afterwards its visceral clefts and arches and the course
of its blood current, show affinities (as we shall see in the thirteenth
chapter) with the class of Fishes. These conditions disappear, and
are succeeded by a structure which, though of a higher nature, yet
for a time remains quite unlike that of a cat, and if the matter of
its body is not that of a cat, neither can its inner principle be that
of such an animal. Change, however, follows on change, till the
activity of the principle which is operating (of whatever kind,) has
so prepared and modified the living mass, that the embryo comes to
assume the shape of a kitten. Simultaneously also, must that prio-
ciple of individuation which is proper to the cat, have informed the

embryonic structure.

In the development of the individual therefore, we see a process
of singular and surprising change, during which a series of transitory

forms successively appear and

* These ‘‘forms” or ‘‘ principles of
individuation’ must, of course, be con-
sidered to be of a different rank and
order from those which inform perfect,
or fully developed, animals. They are
‘‘transitory forms’ specially destined
for a merely temporary existence and for
an end beyond themselves. They have,
moreover, an essential relation to the
parent form which produced them, and
which they normally reproduce.

An embryo taken at any of the earlier
stages of development, is certainly an
animal of a distinct sort, but it is an
animal of an imperfect nature, and not
identical with any of the many kinds
which exist permanently and indepen-
dently.

Some readers may object that they
cannot imagine the advent and departure
of such immaterial entities; and that
allowing that vegetal and animal
psyches do really exist, it is more easy
to imagine one such persisting through
the whole series of developmental changes,
than the succession above represented.
Such objectors say what is quite true, but
not to the purpose. It is not our ‘‘ima-
gination,’’ but our ‘‘ reason,” which has
to decide such questions ; for ‘‘imagina-
tion” is necessarily tied down to sense,
and a ‘‘soul” of whatever kind is (like
all that is immaterial) necessarily imper-
ceptible by any of the senses, Facility

isappear,* and which by such

of imagination is here therefore no test
of truth, but rather the reverse.

If, however, function and structure
ever go together as all physiologists will
adinit, and if the existence of a soul or
principle of individuation be ever in any
case admitted, how, it may be asked,
could an animal psyche co-exist with
a merely vegetal organism, or a rational
principle be present in a being which
has an organisation inferior to that of a
worm? But even the spermatozoon and
the unimpregnated ovum must be ad-
mitted (on account of the internal
activities they show in their develop-
ment and growth) to possess some kind
of life. Can, however, a human soul
be believed to co-exist with either the
one or the other? Yet some principle
of individuation is present in each. We
have herein then an excellent example otf
a succession of principles of different
orders—a succession which cannot be
denied by those who admit the existence
of such entities in any case. There is
nothing more repugnant to reason in be-
lieving that the conjunction of these ele-
ments results in such successive material
transformations as prepare the advent of
the rational psyche by the previous pre-
sence of principles of inferior orders,
than that their conjunction results in
the disappearance ot the two principles
of the ovum and the spermatozoon and

CHAP. XI.)

THE PSYCHOLOGY OF THE CAT. 389 ©

successive appearance and disappearance effect a true process of
continued evolution—bringing about a precise, definite and pre-
determined end by the operation of internal powers, which are
called into active exercise in accordance with their own internal
laws by the stimulus and co-operation of the various physical forces.
Thus the psychology of the cat shows us that there is latent and
potential in matter, special and peculiar substantial forms of force,
such as the psyche of the animal we are considering, and such as
the various lower forms which transitorily manifest themselves as
forme transeuntes, during its process of development. It also shows
us that the very action of one such form may be so ordered as to
result in its own annihilation in order to give place to another,
for the advent of which other its own activity has prepared the way,
and which other emerges from potential to actual existence the
moment the matter has assumed the condition apt for the new
form’s manifestation. The psychology of the cat is, as has been
before said more than once, the physiology of the creature in its
entirety. We shall hereafter have to consider another unity—that
of the race—the evolution of which may, by a remote anology, be
termed ‘the physiology of the species.”” Such an expression 1s not,
however, exact, for a “species” is a creature of the intellect, and
no such creature can have any real action; whereas the individual
animal, with its principle of individuation, is a concrete, really
existing, and really acting entity. Nevertheless we shall presently
see that the psychological considerations here put forward have
their bearing upon the question as to the origin and genesis of the
first cat and of the whole cat race.

the advent of the rational principle at | doctrine of the necessary correspondence
once. The essential notion is the same | of function with structure, and harmo-
in either case, and the difference is but one | nizes rather with the fables of mythology
of degree. To accept the latter belief, ; than the teachings of science.

however, completely contradicts the

—e

CHAPTER XII.

DIFFERENT KINDS OF CATS.

§ 1. In the first chapter of this work the principal varieties of
the domestic cat were shortly described, together with its probable
ancestors, the Egyptian cat and the common wild cat. But our
knowledge of the cat would evidently be very incomplete if no
acquaintance were made with the various animals most closely
related to it, which now exist or have existed, and which may
fairly be reckoned as “ different kinds ot cats.”

In fact, cats of all kinds agree so closely in structure, and differ
so decidedly, in that respect, from animals that are not cats, that
they are universally admitted to form what is called a “very
natural group ’—that is to say, a group of animals easily charac-
terized, and containing no members which differ strikingly from the
other members of the group.

But though it is very easy to say whether an animal is a cat, it
is often exceedingly difficult to determine what kind of cat it is.
The lion, the tiger, the leopard, the puma, and the cheetah, and
various other kinds of cats, are very well-marked forms. No one
can mistake any of these animals one from another, but there are
a great many smaller cats which are in a very different case. Many
of them vary much in colour (and somewhat in shape and more in
size) from individual to individual. Certain kinds have received
from different naturalists more than one name, and it is often a
task of much difficulty to find out which is the proper name which
any given kind ought to bear.

To do this perfectly, it is necessary to examine the very individual
skins which were originally described by the authors of the several
names—which skins are the “types” of the various kinds or
“species.” When (as is very often the case) this is impossible, it
is needful to critically examine the original descriptions, bearing im
mind any collateral circumstances which may throw light upon the
question as to which kind any particular author must have had in
view when he wrote the original description. The investigation of
this complex tangle of zoological literature is called the study of
Synonymy, and it is often a study exceedingly difficult, on account
of the too frequently very imperfect descriptions given by the

> ot ae ie

CHAP. XII] DIFFERENT KINDS OF CATS. 291

proposers of new names. But there is yet another difficulty. Though
the lion, tiger, leopard, &c., cannot be mistaken one from another,
yet all lions are by no means alike, nor are all tigers or all leopards
alike. They all present individual variations, and these are some-
times so marked that certain naturalists have thought it desirable
to distinguish one breed of lion by one name and another by another,
and so with leopards and other species. The questions then im-
mediately arise: (1) are these peculiar forms all ‘‘kinps”’ such as
we must take note of for our present purpose ? and (2) what are
the circumstances which should lead us. to consider any given form
as constituting a distinct “ kind”’ of animal ?

Now, the various breeds of cats, such as we enumerated in the
first chapter, are called “varieties,” while a lion and a tiger are not
called two “ varieties’ but two “species.” What is the difference,
then, between a sPEcIES and a VARIETY P

§ 2. The exact philosophical signification of the term “species”

-will be considered in the last chapter; here, we may take it to have
two meanings—one MorPHOLOGICAL; the other, PHYSIOLOGICAL.
According to the first of these, it signifies a group of animals which
are alike in appearance. If two groups of animals differ markedly
in appearance, and if no transitional forms are known which bridge
over, as it were, the difference thus existing between them, then
such two groups are reckoned as two distinct “species” according
to this first, or morphological, signification of that term, ¢.e., they are
morphological species. The second use of the word “ species”’ is to
denote a group of animals which can breed freely amongst them-
selves, but which, if united with animals of another appearance, will
not produce fertile cross-breeds with them; that is to say, they will
not produce young which can go on indefinitely producing amongst
themselves a race of cross-breeds as freely as either set of parent
animals would have gone on reproducing forms like themselves.

_ Creatures which are in this way restricted, are physiological species.

As to the various breeds of domestic cats, we know that they can
be crossed and will produce perfectly fertile mongrels, and therefore
they are not physiologically “species,” however truly each breed,
as long as it 1s uncrossed, will go on reproducing its own race—i.e.,
will go on “ breeding true.”

As to the wild cats of all kinds—lioons, leopards, &c.—we know
that some of them will interbreed and produce young, but we have
no knowledge that such young will go on freely producing creatures
like themselves, while, from analogy with other animals, we should
be disposed to believe that they would not do so. Still we have ag
yet no observations to determine their specific distinctness physio-
logically, and therefore we must as yet be content to judge of them
morphologically, by the absence that is of intermediate forms
between the apparently distinct kinds. Whenever new forms are
found so intermediate in character between two breeds previously
reckoned as distinct species, that these new forms quite bridge over
the difference previously supposed to exist, then the supposed two

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392 THE CAT.

species must thenceforth be reckoned as one, and that one must
bear the older of the two names previously in use.

_ There is a probability of physiological specific distinctness
wherever there is an absence of transitional forms, for, if two kinds
readily interbred and produced fertile offspring, transitional forms
would, in most cases, soon abound.

For our present purpose, then, the “kinds” of cats which we
have to consider are such kinds as we may reasonably, on morpho-
logical grounds, suppose to be “species” in the full sense of the
term, and therefore, where the differences are confessedly slight and
variable (as between different lions and different leopards), the
creatures which present them will be reckoned as forming one
species only. |

When, however, the evidence is very scanty and incomplett, it is
thought well that kinds should be distinguished provisionally by —
distinct names, on the authority of different naturalists, for fear any
really important kind should get omitted from the list.

§ 3. In zoology (as also in botany) each “species”? has a name
consisting of two words, which correspond with the Christian name
and the surname of a man, except that their order is different—an
animal’s surname coming before the other name. ‘The first word or
term of an animal’s name indicates to which “ group” or “ set” of
species the animal named belongs ; and as each “‘ group” or “ set”
of species is called a “ genus,” this first word is called its “ genere
name. ‘The second word indicates to which kind or “species” of
the genus the named animal belongs, and so this second word is
therefore called its ‘“ specific’? name. . Thus the zoological name of
the wild cat consists of the two words, Felis catus. The first of these
is the generic name, and indicates that the wild cat belongs to the
group or “genus” Ferris. The second word is the specific name,
and shows that the wild cat is that kind of the genus ‘“ Felis”
which is distinguished as “ caus.” |

§ 4. Followimg the order which is traditional, the Lion, with its
regal and national associations, may be taken first.

— (1.) Tue Lion (Felis leo).*

This powerful and well-known cat is at once distinguished from
all others, by the familiar fact that the male possesses a ‘“ mane,”
that is to say, that the hair of the head, neck, and shoulders is
long. The hair also forms a tuft at the end of the tail, at the
extremity of which, surrounded by the long hair, is a small, pointed,
harny appendage. The rest of the body is mostly clothed with short
hair. The adult lion is of a yellowish-brown colour, without spots or
stripes, but the colour varies in intensity, and the long hair is often
biackish. The young are marked with little transverse dark bands

* For a good figure of the skeleton, see De Blainville’s Ostéographie, Felis, plates
5 and 9. © ;

‘ ” CHAP, xI1.]

on each side of the body, and with a longitudinal black mark along
the middle of the back. The mane begins to grow when the animal
is about three years old, and is completed when it is about six
years old.

It is said to live for forty, and certainly lives for thirty, years,
and it attains a length of 94 feet. The animal’s internal organiza-
tion is such as has been already described with respect to the cat,
save in certain details. Thus the pupil is round, never contracting
into a vertical slit. The anterior cornua of the hyoid bone do not
continue up to the skull, but an elastic ligament, about six
inches in length, connects, on each side, the lesser cornu of the
os hyoides with the tympano-hyal. The intestine is four times the
length of the body.”

The convolutions of the brain are rather more contorted than in
the cat, and the same is the case with all the largest species of cat-
like animals. The tapetum extends mostly below the optic nerve,
only a small portion being above it.t The nasal processes of the
maxillary bones end acutely, and reach backwards, on the dorsum of
the skull, as far as, or a little beyond, the nasals.

In the skull of one old lion + which I have examined, there is no
trace of upper true molars, or even of their alveoll.

The lion is not an arboreal animal, but roams over the plains of
the countries it inhabits. It is found generally diffused in Africa,
also in Persia and Arabia, and in Cutch and Gujerat in Western
India. It is occasionally met with as far east as near Allahabad.
Formerly it existed all over central India and in South-eastern
Europe.§ We have no valid ground, however, for believing that a
large maned-cat, or lion, ever inhabited England or the adjacent
part of Europe. .

(2.) Toe TicEr (Felis tigris) ||.

The Tiger is the largest and most powerful of all existing cats. It
is of a bright rufous fawn colour on the dorsal surface of the trunk,
head, and limbs, with vertical and with transverse dark stripes on the
body, limbs and tail. ‘These markings serve to distinguish it from
every other cat. The hair of the vheeks is rather long and spreading.
That of the ventral surface is white. The animal may attain a length
of ten feet six inches. Its maxillary bones end bluntly, and do not
reach as far backwards as do the nasals. The hyoid is connected to
the skull by hgaments—as in the lion. The pupil is round, and
never linear. ‘Tigers that prey on cattle will kill an ox about every

* Owen, Trans. of Zool. Soc., vol. i, | § Lions attacked the baggage camels
pp. 130 and 131. of Xerxes when in Macedonia.

+ Owen, Anat. of Vertebrates, vol. iii., ll See D. G. Elliot’s Monograph of
p. 252. Felide, and De Blainville’s Ostéographie,

¢ No. 4504 a, in the museum of the | Felis, plate 7,
Royal College of Surgeons.

DIFFERENT KINDS OF CATs. 393 ©

304 THE CAT. (ona, xt e

five days, and may destroy sixty or seventy head of cattle in a year.
The tiger very seldom kills his prey by the ‘sledge-hammer
stroke” of his fore-paw, so often talked about. His usual way is
to seize it with the teeth by the nape of the neck, and at the same
time use the paws to hold the victim and give a purchase for the
wrench by which the tiger dislecates its neck.* It is naturally a
cowardly animal, and retreats till provoked or wounded, and may
even be made to drop its prey by cattle rushing at if in a body.

It will eat animals which it has not killed, and even its own
species, for a tiger left wounded is related to have been dragged off
by another tiger and partially devoured.t The tigress breeds ence
a year, and has from two to five pups. Hybrids between the lion
and the tiger are sometimes produced im captivity.

The tiger is not an arboreal animal, but delights in thickets,
especially nearrivers. It is exclusively Asiatic, but has a very wide ~
range, extending from Turkish Georgia, Mount Ararat, Persia, the
Amoor land, and the island of Saghalien in the north, through China
(including Corea) to the south of Hindostan, and the islands of the
Indian Archipelago, down to Sumatra, Java, and the island of Bali;
but it is not found in Borneo, nor in Ceylon. |

(3.) THe Leopard or PanTHErR (felis pardus).t

This animal is very variable in size and in its markings, so that
some naturalists consider that there are several species, which
however seein ill-defined and variable. It is generally of a yellowish
rufous fawn colour, with many dark spots grouped in rosettes, while
the tail is ringed and the ventral surface is whitish. The head and
body are about three feet ten inches long, and the tail is about two
inches shorter.

There is a well marked variety which, though black, shows the
usual markings when viewed in certain lights,

Its pupilis round. The hyoid is connected with the skull by
ligaments, and not by a continuous chain of bones.

The leopard is an arboreal animal. Though so much smaller
than the tiger, old women and children are not unfrequently
killed by it.

This species has a very wide range, being found in Africa from
Algeria to Cape Colony, and in Asia from Palestine and Japan to
Ceylon and Java.

A leopard has been described by Professor Alphonse Milne-
Edwards, under the name of F. Fonteirii,§ and is said to be distin-
guishable by the shorter muzzle, longer and more copious fur, and
by the markings on the flanks being more like rings than rosettes.

* Forsyth’s Highlands of Central | + See Elliot’s Mon., and De Blainville’s
Asia, p. 257. Ostéog. , plate 8. .
+ Jerdon’s Mammals of India, p. 94. | § Recherches sur les Mammiferes,
p. 208, plates 29, 30, and 31.

“CHAP, XIL] DIFFERENT KINDS OF CATS. 395

The tail also is shorter than the body. Two individuals have been
obtained: one from China, the other from Persia.

AA
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Fig. 165.—SKULL or Leopard (F. pardalis).

(4.) THe Ounce (Felis uncia).

This is a very interesting species, exhibiting to us, as it does, a

Fig. 166.—Tag Ounce (F. uncia).*

large feline animal adapted to live in acold climate, as the mammoth
was exceptionally so adapted amongst elephants.

* See Elliot's Monograph, from which the above figure has been, by kind per-
mission, copied.

396 " THE CAT.

It is clothed in a dense long fur, which even forms a short mane.
It is from four to four and a half feet long without the tail, which
measures a yard. The fur is of a pale yellowish grey, with small
irregular dark spots on the head, cheeks, back of neck and limbs,
and with dark rings on the back and sides. It is whitish beneath,
with some large dark spots about the middle of the abdomen; the
rest of the belly is unspotted. ‘The long bushy tail is surrounded by

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Fig. 167.—SKULL oF Ounce (Felis wncia).

incomplete black bands. The length of the head and body is four
feet four inches, that of the tail three feet.

The skull is very high, but concave in front of the orbit when
viewed in profile. The nasals are remarkably short and broad.

The pupil is round.

The Ounce is found in the highlands of Central Asia and the
Himalayas, where it ranges from 9000 to 18,000 feet, rarely descend-
ing very much below the snows. It has, however, been found as
far west as Smyrna.* It is said to frequent rocky ground, and to
feed on wild and domestic sheep, goats and dogs, but has never been
known to attack man.

An animal has been described + as a new species of ounce, under
the name F. tulliana. It seems to be more slender than J. unecia,
with longer legs, and with a longer and narrower head. Its hair
is also less long, thick and soft, while the annular spots are more
numerous and smaller, and the round spots on the upper part of the
back are smaller than those of the flanks. The tail is less thick
and still less completely annulated.

* Jerdon’s Mammals of India, p. 101. cheff’s Asie Min., 1856, vol. ii., p. 613,
+ See Valenciens, Comptes Rendus, | plate 1.
1856, t xlii, p. 1035, and Tchichat-

CHAP. XII] DIFFERENT KINDS OF CATS. "B97

(5.) THE Puma or American Lion (Felis concolor).*

§ 5. The Puma isa large cat, somewhat like a rather slender
lioness, as it is unstriped and unspotted when adult, and devoid of a
mane. It is of a reddish brown or reddish grey colour generally,
whitish beneath. The young are marked with blackish brown spots,
which disappear at about the end of the first year.

Its head is proportionately rather small compared with those of
the large cats already noticed. Its length from snout to tail-root is
generally about forty inches, and it has a tail of some twenty-six
inches.

The skull is neaemmeatle for its depth anteriorly. The os hyoides
is connected with the skull by a continuous chain of bones, as in
_ the cat.

The pupil is round.

The puma eats deer, small quadrupeds, and the Rhea, or American
ostrich, and sometimes destroys human life. It is said to kill by
springing on the shoulders of its prey and then drawing back the
head with one paw till the neck is breken.

It is a remarkably silent animal, never roaring like the lion and
tiger.

a inhabits a very wide range, being spread over America from
the Straits of Magellan to Canada, and ascending the Andes to
9000 feet altitude.

(6.) THe Jacuar (Felis onca).t

This is also a New World species, and the most powerful of the
American cats. Its colour and markings are like those of the
leopard, save that its spots are larger and more definitely arranged
in groups, forming series of dark rings, each ring generally enclosing
one or more spots within it. There is, however, a considerable
amount of individual variation in the extent and arrangement of
these markings, and the most southern forms are said to be
generally yellow and sometimes almost white.

In size the jaguar somewhat exceeds the leopard.

A prominent bony tubercle exists on the middle of the inner or
nasal edge of the orbit.

The pupil is round.

A variety has been described § and figured by Dr. Gray as mee
Hernandesii.

* See De Blainville, 7. c., plate 6, | and De Blainville, 7. c., plate 3; also
and Baird’s Mammals of North America. | Biologia, p. 58. .

See also Godman and Salvin’s Biologia t+ This tubercle exists also in some
Centrali-Americana, Mammalia, by E. | other cats, but is not so largely or con-
R. Alston, p. 62. stantly developed in any other species

T See Elliot’s Monograph, also Cuvier’s | as it is in the jaguar.
Ossemens Fossiles, plate 34, pp. 3 and 4, § Pro. Zool. Soc., 1857, p. 278, plate
; 58.

398 | THE OAT. , [CHAP, XII.

The jaguar is a very fierce animal, and often destroys men and
women. Its favourite haunts are the wooded banks of rivers, and its
habitual food is the giant rodent—the capybara. This great cat
ranges from the Red River, Louisiana, and the Rio Bravo, Texas,
down to the most northern parts of Patagonia, 7.e., to 40° south
latitude. |

(7.) Tue Croupep Tiger (Felis macrocelis).*

§ 6. This very handsome and interesting animal—the last of the
series of very large cats—has a coat, the ground colour of which is

Fig. 168.--THE CLOUDED TicER (Felis macrocelis).

a brownish grey, marked with stripes and spots of black, which form
large and irregularly disposed patches. The under parts are, as
usual, whitish. The cheeks and sides of the head are marked with
two parallel bands, one extending backwards from the eye to beneath
the ear, the other more or less parallel, and passing backwards
from above the angle of the mouth. )

The animal is about forty-two inches long from snout to tail-end,

* See Pro. Zool. Soc., 1858, p. 192. It is described also by Jerdon in his
Mammals of British India.

DP rar, xr.) DIFFERENT KINDS OF CATS. 399

while the tail itself (which is ringed with black) is some thirty-two
inches.

The limbs are short compared with the body and very long tail,
and the head is somewhat elongated compared with that of any of
the cats yet noticed. |

The skull is very long and low. The orbit is widely open behind.

The animal differs from all the cats yet noticed, in that it has not
the tooth described as the first upper premolar, while that answer-
ing to the common cat’s second upper premolar is not very large.

Fig. 169.—SKULL OF THE CLOUDED TIGER (Felis macrocelis).

The upper canines, however, are exceedingly long, longer relatively
than in any other living cat. The upper sectorial tooth has a large
iner cusp.

The pupil is neither round nor linear when contracted, but has an
oblong aperture.

This animal affords a good example of the great imdividual
differences of disposition which may exist in the same species of cat.
One specimen in our Zoological Gardens was a most tame and gentle
beast, while another was quite exceptionally ill-tempered and
savage.

The clouded tiger dwells in trees. It preys upon such animals as
sheep, goats, pigs or dogs.

Its range, though extensive, is more restricted than that of any
species yet noticed, as it inhabits only a portion of south-eastern
Asia, from the eastern Himalayas, through Burmah, Siam and the
Malay peninsula, to Sumatra, Borneo and Java. It also inhabits
Formosa. One from the last-named island has been described by
Mr. Swinhoe as a distinct species.* It is, however, only a some-
what brighter coloured and shorter tailed variety.

* As the short-tailed clouded tiger | Zoological Society, 1862, p. 352, plate

(Felis brachyurus). (Leopardus bra- | 48).
chyurus, Swinhoe, Proceedings of the

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400 THE OAT. [cHar, xm

(8.) THe Turset Ticrer Car (Felis scripta).*

A much smaller cat, but with markings somewhat like those of the
clouded tiger, has been discovered in the mountains of Thibet by the
Abbé David, and made known and named by Professor Alphonse
Milne-Edwards, who has described it as follows :—

General colour pale grey inclining to yellow, with reddish brown
spots and more or less complete black margins. In the scapular
region these spots form longitudinal, undulating bands—looking a
little ike Chinese writing. The largest of these dark lines begins
near the inner angle of the eye, and goes thence above the ear to
the scapular region of the back and then descending obliquely,
widens out. A similar line, placed higher up, extends from the
forehead to the shoulder. There are large irregularly shaped spots
on the sides of the body. At the hinder part of the back they form
bands and bars, not complete rings, on the tail. Part of cheek,
neck and chest white, with transverse black markings. Belly
yellowish, with longitudinal black marks. There are black spots
and bands outside the legs.

The iris is of a yellowish chestnut colour.

Length of the head and body twenty-one and a half inches, of
tail ten and a half inches.

The first upper premolar is small, and appears soon to fall out,
as on one side of the skull figured the tooth is wanting.

It inhabits Monpin in Thibet.

(9.) Fontanetr’s Srorren Cat (Felis tristis).t

This cat may be distinguished from the other species of the
same countries as it inhabits, by its large size, whitish grey colour
and large spots. It is described as follows :—

Fur soft and long; general colour a whitish grey. Three or four
blackish brown lines, beginning in the centre of the head, between
the ears, run along the whole length of the back; rest of the body,
flanks and legs covered with large spots of dark brown. Under-
parts lighter than the upper, legs profusely marked and spotted with
brown. Two bars of rufous brown pass across the upper part of the
breast. Tail very long and bushy, rufous brown above, yellowish
brown beneath. The upper part presenting a series of obscure dark
brown bars.

Length of head and body, thirty-three and a half inches; length
of tail, sixteen inches.

This animal inhabits the interior of China. The skin of the
typical specimen was bought at Pekin.

* A. Milne-Edwards, Nouvelles Ar- | + Alphonse Milne Edwards, Recherches
chives du Muséum, 1870, t. vii., Bulletin, | des Mammif., p. 223, plate 31D, and
p- 92, and Recherches, p. 351, plates | Elliot’s Monograph.

57 and 58, Fig. 1.

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DIFFERENT KINDS OF CATS. 401

(10.) THe Bay Cat (Felis aurata).*

This is a large one-coloured cat, and a very distinct species. It
is from twenty-eight to thirty-one inches long from snout to tail,
while the tail measures sixteen or nineteen inches. It is a bay-red
above, paler beneath and on the sides, with a few indistinct spots on
the flanks. The throat is whitish, while the tip of the tail and the
ears, internally, are blackish. The ventral surface is reddish white,
spotted brown. There are two black streaks on each cheek, with a
pale black-edged line over the eyes.

The pupil is said by Hodgson to be round.

According to Mr. Jerdon it inhabits Nepal and Sikim. Dr. Gray
adds as habitats, Sumatra and Borneo, and one (received by the
Zoological Society from Amsterdam) is said to be from Sumatra.

(11.) Tue Fisutne Car (Felis viverrina).t

This well-marked and very distinct species was originally described
by Bennett in 1833, and the type of the species is preserved in the
British Museum.

Its hair is short and rather coarse. Though usually of a general
dark grey colour (darkest on the back), specimens may occasionally
be found of a reddish grey ground tint. It is always covered with
dark brown spots, smallest and least conspicuous on the shoulders.
The head and back have three or four dark brown lines going
lengthwise, which, however, upon the lower back and rump become
broken up into spots like those on the flanks and other parts. Two
blackish brown lines pass across the cheek, one from behind and
one from beneath the eye, and a line of the same hue crosses the
throat just below the chin. Throat and breast white, the latter
crossed by three or four blackish brown lines passing from shoulder
to shoulder. Belly same colour as flanks, spotted with blackish
brown in continuous lines crosswise. Inside of legs greyish white,
with from two to three dark brown bars crossing the upper part
near the body. Tail rather short, slender, same colour as the back,
barred above with chestnut brown, the bars goimg diagonally, and
meeting in the centre, forming a V-shaped mark; tip chestnut
brown. Underneath greyish white. Length of head and body,
thirty to thirty-two inches; length of tail, nine to twelve inches.
The skull is elongated above. The orbits are completely encircled
by bone. The first upper is present but is very small.

* Felis aurata, Jerdon’s Mammals of | is taken. It is also described by Jerdon
British India, p. 107; F. moormensis, | in his Mammals of British India, p. 103.

Hodgson; /. TZemminckii, Vigors; | It is the animal named Viverriceps
Leopardus auratus, Gray; Cat. Brit. | Benettii, by Dr. Gray, in his Catalogue
Mus., p. 12. of the Carnivora, p. 17, Fig. 5, and in

+ Bennett, Pro. Zool. Soc., 1883, | Pro. Zool. Soc., 1867, p. 286, Fig. 5,
‘3 68. It is described in Mr. Elliot’s | which figure has been here reproduced.
onograph, from which the above figure
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fcr Me Ae Ck UO TREN PR TOR sS te fa xee ct era eek Ne eR aoe ee

ae ai THE CAT, | ‘%

Mr. Jerdon says that the pupil is circular. He also tells us that
F. viverrina ‘is found throughout Bengal to the foot of the south-
eastern Himalayas, extending into Burmah, China, and Malayana,

4 = NS N

eZ

Fig. 170.—THE Fisuine Cat (fF. viverrina)

and that it is common in Travancore and Ceylon, extending up
the Malabar coast as far as Mangalore.” ;

Fig 171.—SKULL or F. viverrina.

Mr. Buchanan says that besides fish it eats Ampullurie and
Unios, and that it has a very disagreeable smell. It is exceedingly
fierce, and has been known to carry off children.

DIFFERENT KINDS OF CATS. 408

(12.) Tue Leoparp Car (Felis bengalensis).*

There is a very distinctly spotted cat from northern India which
is thus named by Mr. Elliot in his Monograph. Either this kind
is subject to great variations in colour and markings, and_somewhat
also in size, or else there are several distinct species, which cannot
yet be accurately defined for want of a sufficient number of
specimens.

Mr. Jerdon gives as the size of his species thus named: ‘“‘ Length of
head and body twenty-four to twenty-six inches; tail eleven or twelve

Fig. 172—SKuLu or F. bengalensis.

inches and more.” He says it is variable, both as to the ground
colour and the size and boldness of its markings, though all adhere
to one general pattern. ;

The ground hue varies from fulvous-grey to bright tawny yellow,
occasionally pale yellowish grey or yellowish, rarely greenish-ashy,
or brownish-grey ; lower parts pure white; four longitudinal spots
on the forehead, and in a line with these four lines run from the
vertex to the shoulders, the outer one broader, the centre ones
narrower, and these two last are continued almost uninterruptedly
to the tail; the others pass into larger, bold, irregular, unequal,
longitudinal spots on the shoulders, back and sides, generally
arranged in five or six distinct rows, decreasing and becoming
round on the belly ; two narrow lines run from the eye along the

* See Jerdon’s Mammals of British
India, p. 105. This animal is the Felis
pardochroa of Dr. Gray (Pro. Zool. Soc.,
1867, pp. 273 and 400; and Catalogue
of Carnivora, p. 28). It is also his F.
tenasserimensis (Pro. Zool. Soe., 1867,
p. 400; and Catalogue, p. 28) and his
fF, Ellioti. The last named is only
represented by skulls in the British

Museum, but these are quite similar to
the skulls of #. pardochroa. It is also
the F. nepalensis of Dr. Gray. Mr.
Elliot, in his Monograph, identifies his
F. bengalensis not only with Dr. Gray’s
above-mentioned species, but also with
his F. Wagati, as to which latter identi-
fication I hesitate to follow him.

DD2

404 THE CAT. (cHap, x.
upper lip to a dark transverse throat-band ; and two similar trans-
verse bands run across the breast, with a row of spots between; tail
spotted above, indistinctly ringed towards the tip; the inside of the
arm has two broad bands, and the soles of all the feet are dark
brown. There is generally a small white superciliary line. I have
noticed in several specimens in the British Museum, that the black
spots unite or tend to unite over the shoulders, so as to make a
conspicuous oval black ring, not unlike the “ Vesica piscis.” This
is not, however, always to be detected.

There is in the National Collection a skin* which came from
the Indian Museum, and which differs considerably from all the
specimens of F bengalensis that I have seen, in its redder colour,
more woolly hair, and thicker tail, as also in the less distinctness of
its markings. It is not however in very good condition. It is said
to have been brought from Nepal by Mr. B. H. Hodgson. The
length of the head and body is twenty-two and a half inches ; ; that
of the tail is sixteen inches.

A jfirst upper premolar tooth is present, but it is very small.
The orbit is nearly encircled by bone. The post-orbital process of
the frontal of the specimen figured has been unfortunately broken.
F, bengalensis inhabits Nepal, Thibet, Darjeeling, Assam, Burmah,
the Malay Peninsula, Sumatra, and Java.

(13.) Tor Waaatt (Felis Wagatt).

The cat in the British Museum which is thus named, is very like
F-. bengalensis; but itis a smaller animal, and its black markings _
are more sharply defined and decidedly in the form of short black —
stripes. ‘The animal also has not the small spots on the flanks
which exist in J. bengalensis, and the stripes ou the shoulders are
nearly parallel and do not tend to form an oval ring. It has been
described by Dr, Gray as follows: “ Fur fulvous; nose, chin, throat,
and underside of body, and streak on forehead and cheek, pale
yellow. Spots of body few, large, irregularly shaped; of withers,
large, elongate, broad ; of loins, elongate, narrow, more or less con-
fluent; tail with round spots.”

Length of head and body, twenty-one and a half inches.

Length of tail, eleven mches.

Habitat, iadin.

(14.) Toe Marsriep Ticer-Cat (Felis marmorata).+t

This cat attains a size of from nineteen to twenty-three inches
from snout to tail, the tail itself being about fifteen inches. It is a
very distinct species.

* Skin No. 79. 11. 25. 563. It is | Gray, Pro. Zool. Soc., 1856, P. 396 ; and
labelled F. Duvancelli. Catolynz Charltoni, Pro. Zool. ‘Soe. ‘;

+ Catolynx marmoratus, Gray, Pro. | 1867, p. 268, and Cat. of Carnivora,
Zool. Soc., 1867, p. 267 ; Felis Charltoni, | p. 16.

|. CHAP. XII.) DIFFERENT KINDS OF CATS. 405

The ground colour of its coat is dingy fulvous, occasionally
yellowish grey, with numerous elongate, wavy, black spots, some-
what clouded or marbled. On the sides of the body are large
irregular patches of a darker shade and with dark margins,
especially on the hinder edge of each patch. The head and nape
have some narrow biackish lines coalescing into a dorsal interrupted
band; a dark line extends backwards from between the eye and the
mouth ; the thighs and part of the sides with black round spots ; the

Fig. 173.—THE MARBLED TiceR-Cat (F. marmorata).

tail black spotted, with a black tip. The belly is yellowish white.
The colour becomes more fulvous with age.

There are several skulls of this species in the collection of the
British Museum. These all agree in having the orbit nearly or
completely enclosed by a bony ring—the postorbital process of the
frontal meeting the postorbital process of the malar in the older
specimens. The skull is very broad at the zygomata. The first
upper premolar is very small, and the first lower premolar is not
very prominent. The premaxille ascend and jom the frontals,
thus separating the nasals from the maxille on the surface of the
skull. The pterygoid fossa is rather well developed.

The pupil is said to be linear.

This species ranges from. Nepal through Burmah and Malacca
to Java and Borneo.

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i is Fe Dinter aN Nah Od Ca din ere YC Ley Clay |
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406 THE CAT.

(15.) Tor Serva (Fels Serval).*

§ 7. This large and well-known African cat has long legs and a
short tail. It is of a more or less tawny colour, with black spots,
and black rings on the tail. The underparts are whitish. Towards
the middle of the back the spots tend to run together into two longi-
tudinal bands. There is no dark streak upon ‘the cheek, but there
are two strongly marked transverse black bars across the inside of
the upper part of each fore-leg.

The length of the head and body may be as much as forty inches,
that of the tail may be sixteen inches.

The pupil contracts into an oblong opening.

There is not only a first upper ‘premolar, but the second npper
premolar is largely developed.

This animal inhabits Africa from Algiers to the Cape.

(16.) THE GOLDEN-HAIRED Cat (Felis rutila).t

This species is founded upon askin described by Mr. Waterhouse
in 1842, and which (the type of the species) is preserved in the
British Museum, but is unfortunately mutilated.

Its colour is ae brown, with indistinct small darker spots on the
sides; back, dark brown medianly ; belly white, with large brown
spots ; tail ted- brown, with a dark ‘central line extending along its
dorsal surface, while at each side it 1s pale, with obscure indications
of darker bands.

Length of head and body about twenty-eight inches; of tail,
fourteen inches.

The skull has the orbits incomplete behind. There is a very
small first upper premolar.

Habitat, Sierra Leone and Gambia.

There are two cats only known to me by description, as to the
distinctness of which I am too much in doubt to venture to enume-
rate them as distinct kinds. They are F. celidogaster and F.
senegalensis.

Felis celidogaster was named by Temminck,} who thus describes
it :—

“Fur short, smooth, shiny, grey, with a reddish tint, with
chocolate or light brown spots; spots on dorsal line oblong, the

* This is described and figured in Mr.
Elliot’s Monograph.

+ Waterhouse, Pro. Zool. Soc., 1842,
p- 130; Gray, Pro. Zool. Soc., 1867,
pp: 972, and 395; Cat. of Carnivora,
p. 23. FF. chry ysothria of Elliot’s Mono-

graph. He identifies it with both the
F. aurata and the F. celidogaster of
Temminck, and with the F. neglecta of
Gray.

: Esquisses Z ologiques, p. 87.

. the ho pe r fe Vv pe ie Sy, A Yu) ih od

“ ‘CHAP, XII.] DIFFERENT KINDS OF CATS. 407

others round; cheeks and lips whitish, with small brown spots;
throat and chest with six or seven half-circular brown bands; lower
parts and inner sides of the limbs pure white, with large round
chocolate-brown spots ; two bands of this colour on the inner side of
the fore, and four on the hind feet; tail bay-brown, with paler
brown rings, end black brown; outer surface of the ears black ;
claws white.”

Length of body and head, twenty-six inches ; that of tail, fourteen
inches. ,

Mr. Elliot identifies this with the / neglecta of Gray and the
F. rutila of Waterhouse (P. Z. 8. 1871, p. 759), and describes it in
his Monograph under the name FP’. chrysothrix. |

The other doubtful species is Felis senegalensis of Lesson.* The
fur of this animal is of a uniform reddish grey, paler beneath, with
black spots inclining on the back to run into longitudinal stripes;
spots on limbs; tail ringed; two black stripes from eye to ear;
muzzle, chin, and throat white.

The individual described was about the size of the domestic cat,
and was regarded as probably immature. It seems probably to
have been a young Serval.

Habitat, Senegal.

As to this species or variety Professor Alphonse Milne-Edwards
has been so kind as to inform the author that no specimen of it
exists in the Paris Museum. The original description was made
from a living animal at the hospital of Rochefort-sur-Mer. <A
young Serval in the Paris Museum closely resembles the description
of F. senegalensis, but has a tuft of hairs on each ear.

(17.) Tae Grey Arrican Cat (Felis neglecta).t

This is rather smaller than the last species, and is well distin-
guished by its grey colour. The type is in the British Museum,
and was originally described by Dr. Gray as follows :—

“Grey; head aud body marked with numerous small darker
spots, spots of the lower part of the sides rather larger; belly white,
with large blackish spots; tail quite half the length of the body,
with a dark line along the upper surface, sides paier, with obscure
indications of darker bands.”

No dark streak on the cheek.

Habitat, Gambia.

* Lesson, Guérin’s Mag. de Zool., | Cat., p. 24. My. Elliot, in his Mono-
1839, t. x., Mammiféres. graph, identifies this with the species
+ Gray, Ann. and Mag. Nat. Hist., | last described; but to me it appears
1838, vol. i., p. 27; Pro. Zool. Soc., | very distinct from the latter.
1867, pp. 272 and 294; and Brit. Mus.

498 THE CAT. : | fomar, xm, a

(18.) Tur Servatine Cat (Lelis servalina).*

This animal is apparently of about the same size as F. neglecta,
but is distinguished from it by its colour, which is yellow, fulvous
above, and white beneath. The middle of the back is darker, with
very numerous small black spots, spots on sides rather larger, on
the belly much larger ; tail short, fulvous, with five or six imperfect
black rings, and a pale tip. No cheek streaks.

The type is said to be in the British Museum.

Habitat, Sierra Leone.

(19.) Tue OcELor (F pardalis).t

8. This beautiful cat, always handsomely marked, is either one
of several closely allied species, or else, as 1s more probable, is subject
to much variation as to coloration and the intensity of its markings.
Besides the typical form, Dr. Gray has distinguished four marked
varieties (or species) which he has named F’ grisea, F. melanura,
F. picta and F. pardoides, and certainly these forms are not only
very different when adult, but, as Dr. Gray says, their characters are
to a certain extent permanent, the young, in some instances at least,
being like their parents, so that they are at least varieties which
‘“‘breed true.”

The ground colour of the ocelot may be tawny yellow or reddish
grey. It is always marked with black spots, which are aggregated
im chain-like streaks and blotches, generally forming elongated spots,
each with a black border, enclosing an area which is rather darker
than is the general ground colour. The head and limbs bear small
black spots, and there are two black stripes over each cheek and one ~
or two transverse dark bands within each fore-leg. The tail tends
to be ringed, and the ventral parts of the trunk and limbs are
whitish. :

Length from snout to tail-root ranges from twenty-six to thirty-
three inches; that of the tail varies from eleven to fifteen inches.

The pupil contracts into a vertical slit. The orbit is not enclosed
by bone.

The creature is a ready climber, and is said to be exceedingly
bloodthirsty.

The variety called / griseat is of a grey colour, even some-
what whitish at the sides; that named / picta,§ differs from the
typical F. pardalis in its less intense coloration, the less degree of
approximation of its stripes and the less amount of difference which

* Ogilby, Pro. Zool. Soc., 1839, p. 4; | Monograph. He considers the here
Gray, Pro. Zool. Soc., 1867, p. 395; and | enumerated varieties to be merely
Catalogue of Carnivora of Brit. Mus., | varieties. See also Godman and Sal-
p- 24; Sclater, Pro. Zool. Soc., 1874, | vin’s Biologia, Mammalia, p. 60.
p. 495, plate 63. Mr. Elliot identifies + Gray, Ann. and Mag. of Nat. Hist.,
this in his Monograph with the Serval, | vol. x., p. 260, 1842; and Pro. Zool.
but in this I cannot at all agree with | Soc., 1867, p. 403.
him. § Gray,.Z. ¢.*

t+ Described and figured in Elliot’s

+.
ro
2 a)
&

al

Ke

cmap. XIL] DIFFERENT KINDS OF CATS. 409

exists between the general ground colour and the parts enclosed by
‘the black borders of the spots and markings. The variety termed

F. pardowdes * is very like the variety F. grisea, but the spots affect

less the form of rings upon the flanks, while the stripes on the neck

are less distinct as well as shorter, the ground colour. of the neck
being redder. ‘There are also more or less spots in the middle of
the back. It differs from the typical F pardahs by its grey
colour.

This greyness in F. pardoides and F. grisea is not the effect of
age, since it already exists in the kittens.

F. pardoides measures about twenty-five inches from snout to
tail-root, and the tail is thirteen inches long.

Very different from all the foregoing, as well as from the typical
F. pardalis, is the variety which has been named F’. melanura.t Its
colours are most intense. The ground colour bemg bright fulvous,
and the black markings exceedingly numerous and deep, while the
white parts stand out in strung contrast to the rest.

The ocelot ranges from Arkansas to Paraguay, and according to
Mr. Elliot, even to Patagonia.

Certain other smaller and beautifully-spotted American cats are
also difficult to distinguish one from another; but it seems to me
there are probably three distinct kinds, which are represented in
our National collection, and are named F. tigrina, F. guigna, and
F.. pardinoides.

(20.) Tae Mareay (Felis tigrina).t

The animal thus named must be another very variable species,

since what I believe to be but different varieties have been de-

scribed as three distinct species, under the names of F. tigrina,
fF. mitis (the Chati), and F’. macroura.

The F’. tigrina of the British Museum,§ has rather hersh fur, of a
dull grizzled colour, varied with black spots and rings. The tail is
marked with small black spots, often confluent, but not forming
continuous rings. There are three transverse black stripes on the

_ cheek. The head and body together measure a little over twenty-

four inches, and the tail is about eleven inches long.

The specimens named F’. mitis and F. macroura || have soft, bright,
fulvous fur, with black spots of variable size, but which are not
united in chains. The black-bordered patches sometimes have a
pale centre.

* Gray, Pro. Zool. Soc., 1867, p. 403.

examining the fine series of specimens
+ Pro. Zool. Soc., 1867, pp. 270 and

in the museum at Paris as well as in the
403. British Museum. I adopt their decision,

¢ See Biologia, Mammals, p. 61. | though I do not feel sure that the F.
Both Messrs. Alston and Elliot have | tigrina and F. mitis of the British
agreed in considering that the three | Museum, may not be distinct species.
varieties are merely varieties; having § Gray, Pro. Zool. Soc., 1867, p. 404.
come to this conclusion after together | Gray, 2. ¢, p. 271.

. Sateen

ee ee) Poe oe eae es ae ho

410. THE OAT. — on

The length of the head and body is nearly twenty-seven inches,
that of the tail from fourteen to nineteen inches. :

The animal ranges from Mexico to Paraguay, in warm lowlands
and well-wooded regions. )

An American variety of cat has been described by Hensel * as
Felis guttula. The account given does not make it clear that it
is a distinct species. The author’s description is as follows :—

“Skull long and narrow, corresponding with that of F’. macroura, .
the facial part is smaller compared with the brain-case. Especially
striking is the height of the skull between the orbits. |

“Ground colour grey yellow; two dark stripes on the head,
and a dark stripe from each eye to the forehead; four stripes,
tolerably broad, run side by side together on the neck to the
shoulder. The sides of the neck are furnished with some dark
marks, and some dark brown or black spots are scattered over the
whole fur. In the middle of the back (where the ground colour is
darkest) there are narrow more or less short stripes, which some-
times run one into the other, forming longer stripes. On the flanks
the spots are larger and have a lighter centre, which, anteriorly, so
approaches the ground colour as to change the spots into rmgs. The
limbs are much spotted externally. The under parts are lighter (or
whitish) and less spotted. There is a white spot outside the external
ear. ‘Tail reaching forwards to the arm, with ten or eleven rings
and a black tip. Size that of the domestic cat.”

Habitat, South Brazil—Rio Grande do Sul.

(21.) Grorrroy’s Car (Felis guigna).ft

The F. guigna of the British Museum was described by Dr.Grayt
by the name Pardalina Warwichii, under the impression that it
came from India, but was recognized by Dr. Sclater§ as being
the South American Cat described by D’Orbigny.|| The latter
animal is indeed so like the F’. guigna of our National collection that
I cannot help identifying them as specifically the same, although
D’Orbigny’s animal is not so much spotted.

It may be described as follows :— |

‘‘Fur short, dusky whitish brown; chin, streak on cheek, and
throat white; chest and underside paler, black-spotted; crown and
nape with four, cheek with two, and between the withers one black
streak ; the four feet and body covered with very numerous, equi-
distant, nearly equal-sized small black spots; throat, chest, upper

* Abhand. Akad. Berlin, 1872, p. 73. | + Gray, Pro. Zool. Soc., 1867, pp. 267
+ Molina, Saggio sulla storia naturale | and 405, plate 25; and Catalogue of
del Chili, i. Ausgb., p. 295. See Elliot’s | Carnivora, p. 14.
Monograph, under the re Seen ie ae Pe Soc., 1870, p. 706; and
royi. See also a paper by Dr. Philippi, (2, p. 203. os mee
i Sa ceiann’ Aethiy. TR7 Ss, p.) S || D’Orbigny’s Voyage dans l’ Amérique
plate 3, where two views of an immature | Méridionale, Mammutres, p. 21, plate 14
* skull are given.

mar. | DIFFERENT KINDS OF CATS. 411
- part of the inside and outside of fore and hind-legs black- banded;
_ tail spotted at the lower half, ringed at the end, with a black tip ;
ears black, with a large white spot.”

Fig. 174.SKULL oF GEOFFROY’s CaT (F. guigna).

The skull is very short and broad, and convex above at the muzzle.
Orbits not completely enclosed ; first upper premolar very small.
It inhabits Paraguay and Chili.

(22.) Tue OcELor-Like Cat (Felis pardinoides).*

This animal was also first described by Dr. Gray under the mis-
_ taken supposition that it came from India.t The type of the
species came from the Zoological Society’s collection, with the re-
putation of an Indian origin. A second specimen, however, cer-
_ tainly received from Bogota, placed its real geographical region
beyond doubt. It is very like F’. guigna, but the spots are much
larger and in the form of dark blotches, each with a black border.
The two skins differ somewhat, the type of the species being
greyer than the skin subsequently received. The skulls also are
_ different, but not more so than difference of age may suffice to
account for, the typical specimen being immature.
= The length of the head and body is about eighteen inches, that
_ of the tail being ten inches.
As has been said, it comes from Bogota.

__™* This animal is identified by Mr. | It appears to me that they should pro-
Z - Elliot with that Jast described, though visionally at least be held as distinct.
_ he allows them to be good “varieties.” + Pro. Zool. Soc., 1867, p. 400.

cl
Pete” re, oe

412 THE CAT.

(23.) THe Yacuaronni (Felis Yaguarondi).*

The Yaguarondi is one of the few unspotted cats, like the lion
and puma. It has a very long tail and a long body, in propor-
tion to the limbs, and its head is long and low.

It is of a blackish or brownish grey, with individual variations,
both greyish and reddish specimens being found in the same
locality. Each hair being blackish grey at the root, then black
and greyish again towards the point.

The female is said to be of a lighter, brighter colour than the
male.

The animal is thirty inches from snout to tail, wlile the tail
is twenty-five inches long. |

The pupil is said to be round.

The skull is elongated and somewhat flattened above, but what
is exceedingly characteristic of the species is the remarkable way
in which the nose is, as it were, pinched in laterally.

It inhabits Brazil, Guiana and Paraguay, and North-eastern
Mexico. :

(24.) THe Hyra (Felis Eyra).t
This is the most remarkable of all the cats, from the extreme

FEARED TE

Fig. 175.—Tue Eyra (Felis Eyra).

length of its body in comparison to that of its limbs—a condition
which gives it somewhat the appearance of a large weasel. It is
also one of the few unspotted cats.

The fur is soft, of a uniform reddish-yellow or chestnut colour,

* See Biologia, Mammals, p. 63. + Biologia, Mammals, p. 64.

CHAP, XII} DIFFERENT KINDS OF CATS. 413

_ with a whitish spot on each side of the upper lip. It is about
_ the size of the doméstic cat, save that its legs are much shorter
_ than that animal’s.

The pupil is round.*

The skull is much elongated and greatly flattened above.

The nose is a little pinched in laterally.

The first upper premolar is present. |

The specimen in the Zoological Gardens was very gentle, but
another one was quite untameable.

It inhabits Brazil, Guiana and Paraguay, and though rare north-
wards of Panama, extends upwards to the Rio del Norte between
Mexico and Texas.

(25.) THE Cotocotto (Felis colocollo).t

This animal is about the size of the common cat or somewhat
larger. It is of a whitish-grey colour, with elongated black marks
on the back and sides, and with a black mark extending from the
eye to the jaw. The tail is said to be semi-annulated and the
_ lower parts of the limbs to be of a dark grey hue.

The skull has the orbits not enclosed by bone.
_ There is no first upper premolar. The upper true molar is
_ visible when the skull is seen in profile. The-infra-orbital fora-
men is large. The skull is much elongated and depressed. The
muzzle produced, and the upper surface of the snout markedly
_ concave when the skull is looked at in profile. When the skull

is seen from above, the prominence of the upper jaw causes part

of the anterior palatine foramina to be distinctly visible. The
_nasals narrow very gradually backwards, and do not extend so far
_ backwards as do the nasal processes of the maxille.

The animal inhabits Guiana and Chili, and doubtless intermediate
countries alos.

4

(26.) THE Rusty-sporrep Cat (Felis rubiginosa).t

§ 9. This pretty little cat is said by Mr. Jerdon to frequent

_ brushwood and grass growing in the dry beds of tanks, as well
asthe jungle.

Its colour is greenish-grey, with a faint rufous tinge; beneath

and inside of limbs white ; a white superciliary streak extending on

_ * This has been kindly ascertained for ; mann’s Archiv, 1873, vol. i, p. 8,
_ me by Mr. A. D. Bartlett, of the Zoolo- | plate 3, Figs. 1 and 2.
- gical Society. t See Mr. Elliot’s Monograph, from
+ Hamilton Smith in Griffith’s Animal | which the above figure has been taken.
Kingdom, vol. ii., p. 479 (with a figure); | It isthe F. rubiginosa of Jerdon’s Mam-
_ F. Cuvier’s Mammiferes, iii.; F. Strigi- | mals of British India, p. 108; and the
_ lata, Wagner’s Supplement to Schreber’s | Viverriceps rubiginosa of Gray, Pro.
_ Saugth., vol. ii., p. 546. See also a | Zool. Soc., 1867, p. 269; and Catalogue
_ paper by Dr. R. A. Philippi, in Wieg- | of Carnivora, p. 18.

414 ‘THE CAT. [onar.

the side of the nose; two dark face streaks; top of head and
nape with four narrow dark brown stripes, becoming interrupted
posteriorly, and passing into a series of rusty-coloured marks, which
on the back, are in the form of streaks, but are roundish on the
sides of the body. ‘Tail short, more rufous than the body, and

x 7
i) f

Fig. 176.—THr Rusty-spottep Cat (F. rubiginosa).

uniform in colour, or very indistinctly spotted, the tip not dark ;
the lower surface and inside of the limbs with large dark brown
spots; feet rufous-grey above, black on the soles; ears small;
whiskers long, white; fur short and very soft.

It is a very small animal, the length of the head and body
being only sixteen or eighteen inches, and that of the tail about
ten inches. Itis a well marked species.

The skull is elongated, though its facial part is short. The
orbit is nearly encircled by bone, and the mastoid process is rather
prominent. The nasal bones are long and narrow, extending
backwards beyond the adjacent parts of the maxille. The first
upper premolar is wanting. !

It is said to inhabit both Madras and Ceylon.

A cat has been described by M. Alphonse Milne-Edwards under
the name of Ff. chinensis, and a similarly named specimen, which
agrees with the description referred to, is in the National collec-
tion. The latter is the type of a species named LF’. chinensie by
Dr. Gray.

(27.) Tue CutnesE Cat (Felis chinensis).*

This animal presents the following characters :—: )
General colour pale yellowish grey, interrupted by a multitude

* Pro. Zool. Soc., 1870, p. 629; and | Milne-Edwards, Recherches des Mam-
Catalogue of Carnivora, p. 27. Also A. | miftres, p. 216, plate 31. fig. 2.

Li) ak Bi Sah a ee ss nites eens f Pate

omar. xm] DIFFERENT KINDS OF CATS. 415

of more or less dark brown spots. Two narrow, elongated white
marks commence beside the nose and extend on to the forehead,
and another, in each zygomatic region, extends back on the neck
beyond the angle of the jaw, with a deep red-brown border above
and below. Muzzle, lower parts of cheeks and chin white, except
part of the upper lip, which is yellow and striped. ine, blackish
stripes on the head, all but the middle one extending to the begin-
ning of the back. Chest whitish, with reddish-brown spots, which
tend to form transverse bands lke 2 series of incomplete collars. The
spots form elongated markings along the back and sides; some-
times the spots of the sides form leopard-like rosettes, but some-
times they do not do so. ©

Length of head and body about twenty-five inches.

Length of tail, twelve inches.

The orbits are nearly enclosed by the post-frontal processes.
The nasals extend backwards about. as far as do the maxilla.
The first premolar falls early.

The animal is found near Canton and in Formosa.

(28.) Tur Smati Car (Felis minuta).*

This animal is very like that last described, but it is smaller, and
the tail is much shorter. The spots also are less rounded and more
in the form of short stripes. The orbits are nearly enclosed by
bone, as in F’. chinensis, but the nasals extend backwards decidedly
beyond the hinder ends of the adjacent parts of the maxilla.

Length of the head and body, twenty-three inches.

Length of the tail, six and a half inches.

This animal inhabits the Indian Archipelago, including Borneo
and at least the island of Zebu in the Philippine group of islands.

‘The F. Herschelii of Gray+ appears to be but a lght-coloured
variety of F’. minuta.

(29.) JERDon’s Cart (Felis Jerdoni).t

This animal is very like F. chinensis and F. minuta, but it is
smaller, and the spots which mark it are darker and more distinct,
and they do not so distinctly form stripes on the shoulders.

The fur is grey, with a few small, distinct black spots. The spots
on the sides of the body and of the limbs are roundish; those of
central part of back are linear and rarely confluent. Tail and feet

* Gray, Cat. of Carnivora, p. 26. scribed till Dr. Gray described it in the
t Pro. Zool. Soc., 1867, p. 401; and | Pro. Zool. Soc, 1867, p- 401; and
Catalogue, p. 28. Catalogue, p. 28. Mr. Elliot identifies

{ The specimen in the British Museum | this with his F. rubiginosa, but the two
which is thus named, was so named | appear to me to be distinct.
orally by Mr. Blyth, but was not de-

|
:
|
|

ae THE CAT. [owar. xm,

dark grey brown, scarcely spotted; chin and under parts, white
with black spots.

Length of head and body, seventeen and a half inches.

Length of tail, five and a half inches.

(30.) THe Javan Car (Felis javznensis).*

This form is added doubtfully as a distinct species. It is repre-
sented in the British Museum by a specimen of small size and of a
greyish-brown colour with round spots, of a reddish-brown tint, on
the sides, and with blackish longitudinal streaks along the back.
There are two stripes on the cheek. Beneath, it is whitish, with
largish, brown spots.

Length of the head and body, twenty-two inches.

Length of the tail, seven and a half inches.

(31.) THE Busuy-TaiLep Rep-sporrep Car (Felis euptilura).t

This species was first described by Mr. Elliot from a very imper-
fect skin, which is the type of the species, and is preserved in the
British Museum. There is also there preserved a specimen from
Shanghae, which closely resembles the skin described by Mr. Elhot
and is similarly named.

The following is Mr. Elliot’s description :—

“Ground-colour of the body light brownish-yellow, strongly
mixed with grey, covered with reddish-brown spots rather oblong im
shape, darkest and most conspicuous on the hind quarters; head
grey, with a white line under the eyes and on’ the side next to the
nose; two dark brown stripes on the centre, commencing at the tip
of the nose, and one on each side, beginning at the eye, pass over the
top of the head, and down the back of the neck to the shoulders; a
dark-red stripe runs from the corner of the eye, across the cheek to
the base of the ear; and another, rather lighter in colour, starting
below the eye, passes across the cheek and curves back under the
throat. The centre of the back is much darker than the sides, with
spots of dark brown. Under lip white, as is also the throat and under
parts. Across the upper part of the breast are four broken bands of
foxy red; belly covered with large brown spots, becoming rufous
between the hind legs. Inuer side of hind legs buff, with cross bands
of foxy-red, and covered with small reddish spots to the toes. Tail
thick, rather short, bushy, darker than the body, with several
incomplete broken rings of blackish brown. Inside of ear buff,
behind black.”

Size about that of the common cat.

The orbits are nearly enclosed by bone. The nasal bones extend
back decidedly beyond the nasal processes of the maxill®. The
nasal region is much pinched laterally. There is a small upper front
premolar.

* Gray, Catalogue of Carnivora, p. | piate 76. It is also described anc

: figured in his Monograph.
+ Elliot, Pro. Zool. Soc., 1871, p. 760, t No, 52. 3. 19. 1.

DIFFERENT KINDS OF CATS 417

(32.) THE Smatt-EaRED Car (Felis microtis).*

This cat is very like / chinensis, but differs from it by the small
size of its ears. The infra-orbital foramen is, moreover, divided.

The hair is long, soft, and very abundant. The general colour is
that of F’. chinensis, but the spots are redder and more confused ;
the markings of the zygomatic region are less distinct, as are those on
the head and neck. The ears have each two white spots behind,
separated by a vertical blackish-brown band, while in F. chinensis
the ears are black and have but a single white spot. The tail is
not distinctly spotted. It inhabits the neighbourhood of Pekin, and
is also found in Mongolia.

(33.) THe LarcE-EareD Cat (Felis megalotis). +

This animal appears to be only known by Miiller’s description.
He tells us:—‘“ This new species is of the size of Felis minuta; it
has, however, much longer and more projecting ears and a much
larger tail, which is not round but more or less flattened. The
general colour is yellowish, the back reddish-yellow, and the under
parts more of an isabella colour The hairs of the head, neck,
shoulders, hind legs and tail are annulated with black rings, which
results in giving a marbled appearance to the body ‘There are
some transverse black stripes on the hind legs, and some reddish-
yellow and black stripes on the fore legs. The claws are lght
yellow. A dark stripe proceeds from beneath the eyes to the
ears, where it breaks up into narrower stripes. The hairs of the
tail are longest at each side, so as to form a lateral fringe, which
gives the tail its flattened appearance. The tail is partly rmged in
an indistinct manner. ‘The ears are bluish-white within. The
iris is orange-yellow.

(34.) THe Fiat-HEApDED Car (Fels planiceps). {

This very peculiar and exceptional cat is one-coloured, with a long
body and short legs and tail.

It may be thus described :—

Fur thick, soft, and long. Top of head dark reddish-brown.
Two yellow lines extend upwards (one on each side) from between
the eyes to near the ears; body dark brown, darkest on the back,

* Alphonse Milne- Edwards. Recherches
p- 221, plates 3la and 310, Fig. 1. See
also the right-hand figure in Mr. Elliot’s
plate of F. euptilura. Myr. Elliot identi-
fies this species with his F. euptilura.
The figures, however, appear to me very
_ different, and I think it best to keep it
distinct, at least provisionally.

+ Miiller, Vertiand.. over de Natuur-
lijke Geschiedenis Zool., Leyden, 1839-
1844, Part I. ; Over de Zoogdiernen van

Bi.

den Indischen Archipel., by Salomon
Miiller, p. 54.

t See Mr. Elliot’s Monograph, from
which the above figure was, by per-
mission, copied. It is the Viverriceps
planiceps of Gray, Pro. Zool. Soc.. 1867,
p- 269; and Catalogue of Carnivora,
p- 17. It is the F. pluniceps of Vigors
and Horsfield, who first described and |
figured it in the Zoological Journal,
vol, iii., p. 449, plate 2.

EE

ye

0 eee

418 THE CAT, _ [ CHAP, x11,

every hair tipped with white, a silvery-grey appearance being
thereby given to the cat. Face beneath the eye light reddish, with
two narrow dark lines across the cheeks to beneath the ears.
Throat, breast, and belly white, the latter spotted and marked with
rufous. Inside of legs rufous-brown, growing light towards ‘the

fi

Oh Yy LGA
MK
) it if /

Fig. 177.—THE FLAT-HEADED Car (F, planiceps).

feet. Tail rather short and thickly furred and of a reddish-brown

Fig, 178 —Skunt or Fiat-ueapep Cat (Felis planiceps)

colour above, beneath yellowish-brown. It is about the size of a
domestic cat.

HAP, XII] DIFFERENT KINDS OF CATS. 419
Length of head and body from twenty-one to twenty-four inches.
Of tail, from six to eight inches.

The skull is elongated and the orbits are completely enclosed by
bone, but its most remarkable character is the large size of the first
premolars both above and below. The first upper premolar is two-
rooted and largely developed, its crown being sometimes actually
longer from above downwards than is the sectorial tooth. The first
lower premolar is also as vertically extended asis the second. This
structure would accord with a fish-catching habit, like that which is
attributed to Felis viverrina.

Dr. Gray gives Malacca, Sumatra, and Borneo as the habitat of
this species.

(35.) Tue Bornean Bay Car (felis Badia).*

This unspotted and therefore exceptional small species of cat was
firs; made known by Dr. Gray from a very imperfect skin (the
type of the species) which is now in the British Museum. It is
thus described :—

“Fur of a bright chestnut colour, rather paler beneath, the
limbs and the tail bemg rather paler and redder. The tail is
elongate, tapering at the end, with a white central streak occupying
the hinder half of the lower side, gradually becoming wider and of
a purer white towards the tip, which has a small black spot at its
upper end. The ears are rounded, covered with short blackish-
brown fur at the outer side, pale brown within, and with a very
narrow pale margin. The sides of the upper lip, a small spot on ~
the front angle, and the edge of the upper eyelid pale brown. The
chin, edge of the under jaw, and gullet whitish.”

The orbits are nearly encircled by bone, and there is a good-sized
pterygoid fossa. Unlike F. planiceps, this cat has its first upper
premolar of but small size and with a single root.

Habitat: Sarawak, Borneo.

(36.) Tue Eoyprian Cat (Felis caligata).t

§ 10. This species varies from pale fulvous, to grey or pale
yellowish, with darkish transverse markings on the legs and towards
the end of the tail, and two transverse streaks on the cheeks.

As has been said in the first chapter, this species is probably the
main source of the domestic cat.

According to Dr. Gray, “ Many specimens of Felis caligata from
Africa, like Felis domestica, F. indica, and F. torquata, and many
other species, have the hinder part of the feet black; but this is
not a permanent character; for some of the paler specimens of
fF’. caligata have the hind feet paler than the back of the animal,

* Gray, Pro. Zool. Soc., 1874, p. 322, | Felis maniculata, Riippell, Zool. Atlas,
plate 49. i, t. 19; Felis Chaus, Riippell, Zool.
+ Gray, Brit. Mus: Cat.,.p. 29; '! Atlas, i., t. 140.

: . EE 2

420 THE CAT.

and some of these have fs heels more or less brown or blackish on.
the outer edges.”

The tail is long.

Pale varieties of this cat seem to have been mistakenly described
as identical with the jungle cat (Felis Ohaus) of India, and also with
the Indian, Felis torquata.

(37.) Taz Wiip Car (Felis catus) has been already sufficiently
described in the first chapter.

(38.) Taz Inpian Wirp Cat (Felis torquata). *

This cat has much resemblance to the European wild cat, but it
is more fulvous and less striped, and is more slender in its build.

Length of the body and head from sixteen to eighteen inches.

Length of tail, ten to eleven inches.

Habitat: India.

(39.) THe Common Juneie Cat (Felis Chaus).+

The common jungle-cat is of a yellowish-grey colour, more or less
dark and unspotted, approaching to rufous on the sides of the neck
and abdomen, where it unites with the lower parts; a dark stripe
extends from the eyes to the muzzle. The ears are slightly tufted,
rufous black externally, white internally.

The limbs have two or three dark stripes internally, and they are ~
occasionally faintly marked externally also.

The tail is short, reaching to the heel, and more or less annulated
with black—most so in the young.

Length of head and body, twenty-six inches; of tail, nine to ten
inches.

Pupil, oblong erect. |

Skull with the orbits open behind, and with the upper premolar
distinctly developed.

This cat ranges all over India, from the Himalayas to Cape
Comorin and Ceylon, and from the sea level to 8000 feet elevation.

(40.) THe Ornate JunetE Cat (felis ornata).t

This cat “is at once well known from all the other Indian
species by the dimensions of the tail and the small size and equal
distribution of the spots. In this respect it resembles the Hunting

* F. Cuvier, Mammiféres; Jelis in- | Mus. Cat., p. 36. See also Elliot’s

conspicua ; Gray, Pro. Zool. Soc., 1867,
: eke and Catalogue of Carnivora,

Be cee Mammals of India, p. 111 ;
F. (Lynchnus) erythrotis, Hodgson ; F,
Jacquemontii, Is. Geoffroy St Hilaire ;
Chaus Jacquemontiit, Gray, Pro. Zool.
Soc., 1867, p. 275, and Brit. Mus. Cat.,
p- 34 ; Chaus Catalonyx, Gray, Brit.

Monograph.

t+ Gray, Illustrations of Indian Zoo-
logy and Pro. Zool. Soc., 1867, p. 401 ;
Chaus ornatus, Gray, Pro. Zool. Soc.,
1867, p. 275; and Brit. Mus. Cat.,
p- 35 ; ri torquate, Jerdon’s Mammals
of Brit. India, p. 110. See also Elliot’s
Monograph. oo

fo) CHAP, ‘XII. ] DIFFERENT KINDS OF CATS. 421
Leopard. The tail is somewhat like that of F. Chaus. The ears
are slightly pencilled at the tips. The fur is short and of a pale
whitish-brown. The spots form transverse bands on the legs. The
belly has black spots like those of the sides.”’
ae of head and body, nineteen inches; that of tail, eight
inches.

The skull has the orbits open behind, and the nasal bones are very
long and slender. There is a distinct first upper premolar.

It is said to breed rather freely with Indian domestic cats. *

Habitat: desert regions of North-western India.

(41.) THE Steppe Cat (Felis caudatus).t+

The following are the characters of this animal :—

Fur close, soft, pale yellowish, blackish brown at the base, with
very numerous small irregular spots. The spots are smallest and
roundest on the dorsal line, obiong on the sides, and forming inter-
rupted lines on the shoulders and thighs, which are most distinct on
the outside of the fore-legs, and especially forming four broad cross
streaks on the front edge of the thighs; tail cylindrical, reaching to
the ground, spotted at the upper part of the base, and with eight or
nine narrow interrupted rings on the upper part of the remaining
portion, with a black tip. Nose brown, with short hair. Forehead
and cheeks hike the back, but with smaller spots, and without any
distinct dark streaks from the back edge of the eye. The ears
ovate, acute, pale brown externally, with a termmal pencil of
blackish hairs, and whitish on the edge within. Chin, hinder parts
of the upper lip, under parts of the head, throat, chest, belly, inside
of legs, and hind feet whitish brown, the chin being whitest and
the inside of the hind legs and feet darkest. There is a large
blackish spot on the upper part of the inside of the fore legs, and two
small cross streaks on the front edge of the inside of the thighs.
The hinder part of the hind feet to the heel blackish. Length of
body and head, twenty-three inches and a half; of tail, twelve inches
and a half; height of shoulder, twelve inches.

The orbits are incompletely encircled by bone. There is a small
anterior upper premolar. The anterior lower premolar is large.

Habitat: Bokara.

(42.) SHaw’s Car (Felis Shawiana). {

This cat appears to be distinguished from F. caudatus by its much
shorter tail; from /. Chaus by being spotted throughout, and from
F. ornata by its short tail, more rufous coloration, and distinct black

* See Blyth, Pro. Zool. Soc., 18638,
p. 184. The same is said to be the case
with F. Chaus and F. rubiginosa.

+ Gray, Pro. Zool. Soc., 1874, p. 31,

plates 6 and 7, under the name of Chaus
caudatus.

+ Blandford, Journal Asiatic Society
| of Bengal, vol. xlv., part 2, p. 49.

422 THE OAT. (CHAP. XII,
spots on the abdomen. It is very different from F. euptilura,
which has red spots on the sides and rufous bars across the breast.

Length, from snout to root of tail, twentv-five inches; of tail,
seven and eight inches.

The skull is very long.

General colour pale greyish fulvous above, the back rather
darker than the sides, underparts white ; the body marked through-
out with rather small black spots, which are largest on the abdomen,
smaller and closer together on the shoulders and thighs, tending to
form cross lines on the latter, and indistinct on the middle of the
back; anterior portion of the face and muzzle whitish, cheek
stripes of rusty-red and black hairs mixed. Ears rather more
rufous outside, especially towards the tip, which is blackish-brown,
and pointed, the hairs at the end scarcely lengthened, interior of
ears white. ‘nere are some faint rufous spots “at the sides of the
neck. Breast very faintly rufous, with one narrow brownish band
across. Inner sides of limbs mostly white, a black band inside the
forearm, and a very black spot behind the tarsus. Apparently
there are two black bands inside the thigh. Tail dusky above near
the base, with five or six black bars above on the posterior half,
none below, the dark bars close together towards the tip. Fur soft,
moderately long; the hairs purplish- -grey towards the base. Size,
larger than the common cat, about equal to that of F. Chaus,

Habitat: Kastern Turkestan, Yarkand, and Kashgar.

(43.) THe Manu (Felis Manul).*

This handsome animal is the wild cat of Thibet, Mongolia, and
Siberia. It is smaller than the common cat, with very long, soft
and abundant hair. It is of a pale whitish colour, varied by a
shght black mark on the upper part of the legs and chest. The
hairs are yellowish-grey at the base, then yellowish, with their
points white. There are a few transverse dark bands on the loins,

which are black, narrow, and rather far apart. A white streak,
bordered by black above and below, passes obliquely downwards
and backwards from behind the eye, and there is another black
mark behind the ear.

Length from snout to root of tail, twenty-one inches.

Length of tail, ten inches.

The skull is remarkable for its breadth and the prominence of
the interorbital region as compared with the nasal region. The
nasal bones are very narrow for their hinder two-thirds, and then
broaden out rather suddenly, forwards.

Habitat : Thibet to Siberia.

* Alph. Milne-Edwards, Recher. des | Zool. Soc., 1867, p. 874 ; and Catalogue
-» p. 225, plate 31c; Gray, Pro. ' of Carnivora, p. 33.

DIFFERENT KINDS OF CATS. | 423

Fig 179. THe Mano. (F. Manul).

(44.) THe Srraw or Pampas Cat (Felis pajeros).*

This animal is about the size of our wild cat, but is more robust in
build, with a smaller head and a shorter tail. The hair is long, and
the colour of the body is yellowish-grey, marked with transverse
bands of yellow or brown, which run obliquely from the back to the
flanks. Two patches descend from the eves over the cheeks, and
meet beneath the throat. The animal is whitish beneath. The
legs and tail are marked with dark bands.

Length from snout to tail root, twenty-five inches; length of tail,
twelve inches.

The skull has the snout remarkably short, and therefore is very
convex above anteriorly when seen in profile. The nasal region is
much pinched in laterally, and the nasals are very narrow in their
hinder half. The zygomata are greatly arched outwards. The first
upper premolar is wanting. The cusp of the first lower premolar is
much prolonged.

This animal appears to be a New- World form which represents as
it were F. Manul of the Old World.

It inhabits the Pampas and Patagonia down to the Straits of
Magellan.

* Gray, Pro. Zool. Soc., 1867, p. 269; | Philippi, in Wiegmann’s Archiv, 1878
and Catalogue of Carnivora, p. 18. For | p. 8, plate 3, figs. 3 and 4.
the skull, see a paper by Dr. R. A.

424 THE CAT.

(45.) THe Nortuern Lynx (Felis lyncus). *

§ 11. The lynxes are animals which present a markedly different
aspect from that of other cats. Their legs are long and their tail
is, with one exception (that of the caracal), very short. Their ears
also. are tufted at the tip. The pupil is lmear when contracted.
The orbits are incompletely surrounded by bone. They have no
tooth representing the common cat’s first upper premolar, while
that answering to its second upper premolar is largely developed.
The intestines are also very short. +

The lynxes thus form a little group apart, being structurally more
separable from the bulk of the cats than are the lion, tiger, jaguar,
puma, and leopard, which are separable from the mass of feline
animals as the emphatically “large cats.’ Still the above given

characters are variable in the cat group. In some cats, other than

lynxes, the tail is short, and some have the ears more or less pen-
cilled. Some, as we have seen, have long legs, and in many the
first upper premolar is wanting. The lynxes therefore cannot be
separated off as a nominally distinct group or “ genus.”

The lynxes are very variable in their colour and markings, and

the northern lynx also varies greatly in the abundance of its hair,
according to the season—the animal having a very different aspect
in winter from that which it presents in summer. ‘The northern
lynxes are gencrally reckoned as forming two species, one belonging
to the old world, F. borealis, and at least one species belonging to
the new, Ff. cunadensis. The American forms are also often de-
scribed as alone constituting three species—namely, PF. canadensis,
F. rufa, and £. maculata. After a careful examination of the rich
series of skins at the British Museum, I am, however, not only
quite unable to regard the American varieties as anything more
than varieties, but I am inclined to the opinion that there can be
no real specific distinctness between the northern lynxes of the two
hemispheres—their skulls as well as their skins bemg so much
alike. t

A. The variety generally distinguished as F. borealis is of a
reddish-grey cvlour, sometimes more or less spotted, sometimes very
distinctly so—especially when young. Its winter dress is more grey
in colour and is much longer and thicker than its summer coat.

* De Blainville, Ostéog. Felis, plate 3. + On this question Professor Alphonse

+ According to Professor Owen (Trans. Milne-Edwards has been so obliging as to
Zool. Soc., vol. i., p. 131), they are only | send the fcllowing statement of his
twice the length of the body, being | opinion :—‘‘ The study of the different
relatively the shortest intestine known | kinds of lynx is a very difficult study.
to exist in the Felidae. The hyoid is | Whether there are several species in the
connected with the skull by a continuous | northern hemisphere, or only races, is a
chain of bones, as in the common cat. | question which I cannot answer. There
The ciliary folds of the eye are very long, | are certainly distinct forms, but before
and the retina, which is very thin, does | ranking them as species it would be
not reach the meridian of the eyeball, | necessary to determine what variations
Owen, Anat.of Vertebrates, ili., p. 252. ' are due to climate, season, age, sex, &c.”

bic
“aie te Se

CHAP. XII. ]

DIFFERENT KINDS OF CATS. 425

The fur of the cheeks is generally long, so much so as to form a

pendent thick fringe on each side, but the extent of this develop-

ment varies greatly. The pads of the feet are more or less over-
own with hair.

It inhabits Northern Scandinavia, Russia, Northern Asia, and
some of the mountainous districts of Central Europe. One was
killed at Wurtemberg as late as 1846, and in 1822 one was killed
in France at St. Julien Chapteril, in the department of the Haute
Loire.

This animal is said to attain the length of fifty inches, but I have
seen none longer than about forty inches from snout to the root of
the tail.

B. The variety known as F. canadensis, is, in colour, very like
F. borealis, but all the specimens I have seen are smaller, bemg about
thirty inches from snout to tail root, with a tail five inches long.

C. The variety named F’. rufa* is, as its name implies, of a
reddish colour; its fur is shorter and less abundant than that of the
variety named F. canadensis.

Fig. 180.—THe NorRTHERN LyNxX, VARIETY F. maculata.

D. The variety called F. maculata is a very handsome one, its
fur being ornamented with many spots; but skins exist which
present every transitional condition between the long-haired spotted
form known as F. maculata and the other American forms. This
variety extends across the North American continent from the Rie
Grande to Southern California, going at least as far south as

* Biologia Centrali Americana, Mammals, p. 64.

ri
eid |

[cHAP. XI,

426 THE CAT.
Guanajuato,* and probably extending to near the city of Mexico.
It is therefore an interesting kind, as being the most southern form of
Lynx as yet known to exist. The /. maculata figured measures thirty-
five inches from snout to tail root, and the tail is six inches long.

(46.) THe Parpine Lynx (F’. pardina).

This is the South European lynx. ‘The colour is rufous above,
white beneath, with numerous rounded black spots over the body,
the limbs, and the tail.

Tt presents no noticeable difference as to size from F. /yncus.t

At first I was disposed to regard this form as a mere variety of
the northern lynx (the species thus becoming spotted in southern —
latitudes in the old world, just as it becomes spotted in the
warmer regions of the new world), but an examination of the skulls
inclines me to regard F. pardina as a really distinct species. When
the skull is seen in profile it differs from the skulls of the varieties
F’. borealis, F. canadensis, F’. rufa, and F. maculata, in that it appears
much more raised and convex between the orbits, while the skulls
of the four just named varieties are relatively flat. The nasals of
F. pardina extend backwards beyond the nasal processes of the
maxille.

This species is found in Turkey, Greece, Sicily, Sardinia, and
Spain. In Andalusia it is very often called Gato serval, an inter-
esting indication of the African origin of part of the population, of
that Province.

(47.) Tue Tuiser Lynx (£- isabellina). t

This form is only ranked as a species provisionally and with
much doubt. There is in the British Museum the mounted skin of
a large lynx, which is uniformly of a very pale isabella colour.

Length of head and body, forty-one inches.

Length of tail, seven inches.

Though so markedly different in colour it may be but a pale
variety of I. dyncus. §

(48.) Tur Caracat (Felis Caracal). ||

The caracal is a well-known kind. Itis of a slender build, with long
limbs and with a tail longer than in the other lynxes, reaching down
to the animal’s heels. The ears are three inches long.

* Biologia, 7. ¢., p. 65.

+ There is a specimen in the British
Museum which measures forty-one inches
from snout to tail-root, with a tail seven
inches long, and which is covered with
black spots. It is labelled Lyncus lupu-
linus, and has been described by Dr.
Gray (Pro. Zool. Soc., 1867, p. 276) as a
new species. It was brought from the
museum of the Zoological Society, and is
represented as having come from Norway.
But this representation was probably

erroneous.

+ This is the /. tsabelline of Blythe.
Gray, Pro. Zool. Soc., 1867, p. 276.

§ Dr. Scully has very kindly shown
me the skins obtained by him in Central
Asia, one of which at least is intermediate
in coloration between F. lyncus and F.
isabellina.

|| Jerdon’s Mammals of British India,
p- 113. See also Elliot’s Monograph
and De Blainville’s Ostéographie, plate
10.

oe
h
iT
¥
s

DIFFERENT KINDS OF CATS. . 27

_ Itis of auniform vinous, or bright fulvous brown colour above, and

is paler, sometimesalmost white, beneath. Itis quite or almost entirely
un spotted, but some obscure spots are visible,in some specimens, on the
flanks, belly, and inner surface of the limbs. The tail has a black tip.

The pads of the feet are bald. The skull is rather convex
between the orbits, as in F’. pardina.

Length of the head and body, twenty-six to thirty inches.

Length of the tail, nine or ten inches.

This animal is found in North-western India and in Central India
to the east coast: also in Thibet, Persia, Arabia, and throughout
Africa.

(49.) THe Common CHEETAH or Huntine LeEoparp
(Cynelurus gubata).*

§ 12. This cat differs much more from all the other cats than any
other two cats differ one from another, and it therefore may be dis-
tinguished as constituting a nominally distinct group or “‘ genus.”

It has a short rounded head, with long, slender limbs and a long
tail. Its ears are rounded, and not at all pencilled:

It is a large animal, being four and a half feet long in head and

_ body, and with a tail two and a half (or two and three-quarters)

feet long.

Tts colour is bright rufous fawn, powdered with black spots. These
are not like those of the leopard—arranged in rosettes, nor, as in
the jaguar, in rings; neither do they run together into stripes or
elongated patches, but are distinct, plain, round marks. ‘The tail,
however, is more or less ringed with black. The hair of the neck
forms something of a mane, and that of the belly is long and light-

coloured.

A black stripe runs downwards from the imner angle of the eye to

_ the margin of the upper lip near the angle of the mouth.

Such are its colour and markings when adult. The young are
covered with long soft hair of a dark-brown colour, very obscurely
spotted. The head, the back of the neck, the back, and the upper
surface of the tail, are pale brown. They have altogether a singularly
different appearance from the adult.

The cheetah has the claws always more or less exposed, not being
completely retractile as in the other cats, though it is furnished with
the same kinds of ligaments that they have.

The skull of the cheetah is also very different in shape from the
skull of every other. cat—being very high in proportion to its
length. The nasals are short, but not so short as in the ounce.
There is more than one infra-orbital foramen on each side. The
upper true molar is visible when the skull is seen in profile. The

* Jerdon’s Mammals of India, p. 114; | Blainville, Ostéog., Felis, plate 4
Gueparda, Gray, Pro. Zool. Soc., 1867, | (skeleton).

- p. 396 ; and Cat. Brit. Mus., p. 39: De

428 THE CAT.

first upper premolar may be present or absent. The second pre-
molar is very large, projecting downwards as much as does the
sectorial.

Fig. 181.—THEe CHEETAH (Cynelwus *ubata).

The upper sectorial differs from the corresponding tooth in all
living cats, in that the inner cusp of that th is so rudimentary as

to be almost wanting.

Mi

wl

= 5

Miia <<
ME

dc

Fig. 182.—TuHr Yocune CHEETAH,

The os hyoides is connected with the skull by a continuous chain
of bones—as in the common cat.

DIFFERENT KINDS OF CATS. 429

The metacarpals and metatarsals are relatively long.
The brain is considerably convoluted.*
The corpus albicans is fairly divided into two corpora mammillaria,
as in various other large cats.
The pupil is round when contracted.t
The animal, as is well known, is employed for the chase, being
taken to the hunting field in a cart, with a hood over its head. Mr.
Jerdon has observed it, when let loose after the game, crouch

Fig. 183.—SKULL oF THE CHEETAH (C. jubata).

along the ground, and seek out every inequality of surface to enable
it to get unseen within proper distance of the antelope it was
pursuing. Nevertheless it can run with a velocity as great as that
of a well-mounted huntsman.

The cheetah is found at least in Western, Central, and part of
Southern India, also in Syria, Mesopotamia, Persia, and Africa, to
near the Cape—certainly in both Senegal and Kordofan.

(50.) Tae Woonty CuHEEetan (Cynelurus lanea).t

This species has been recently described by Dr. Sclater, and
appears to me to be distinct, though Mr. Elliot regards it as a mere
variety of the common cheetah.

* See Owen, Trans. Zool. Soc., vol. i., | Bartlett.

plate 20. t Pro. Zool. Soc., 1877, p. 532, plate
+ Of this I have been made aware | 55.

through the kindness of Mr, A. D.

430 THE CAT.

It differs from the latter in that it is thicker in the body, and has
shorter and stouter limbs, and a much thicker tail. Its fur is also —
more woolly and dense, particularly on the ears, mane, and tail.
The whole of the body is of a pale isabelline colour, rather paler on
the belly and lower parts, but covered all over, including the belly,
with roundish, dark, fulvous blotches. There are no traces of the
black spots which are so conspicuous in the cheetah, nor of the
characteristic black line between the mouth and the eye.*

The animal described came from Beaufort West, in Cape Colony.

§ 18. With the last-named animal closes the list of n1vine cats
which it is thought may certainly, probably or very possibly, be con-
sidered as distinct “species.” But while doubtless some new species
may yet be discovered, yet it is, on the other hand, very probable
that various forms here enumerated as very possibly or probably
distinct may turn out to be mere varieties. The domestic cat is
said to breed, in India, with #: Chaus and F. rubiginosa, and with
other species in Ceylon and Africa, and the produce of some of
these unions may themselves be fertile, and if so, the parents must
be classed as belonging to one and the same species. .

Casting a retrospective glance over the characters of the species
described, we see that they differ but in few points. The uniformity
of their structure, and even of their colour, is very remarkable. Some
reddish or yellowish shade more or less modified by grey or brown, may
be said to be their ground tint, marked generally with spots, often with
stripes more or less black, with the under parts of the body whitish. -
Very generally there are two transverse stripes on the cheeks, and
bars on the inside of the upper arms, with dark rings round the tail.
There are no wild kinds of a pure white, nor is there any black or black-
and-white species, while it 1s only a few kinds that are of a uniform
tint and unspotted. The various kinds differ in size,in details of colour,
in the length of the hair of certain parts, in the length of limbs
compared with that of the body, and in the length of tail. They
also differ as to the presence or absence of a tuft of hair on the ear-
tips, the form of the skull, the enclosure or non-enclosure of the
orbits by bone, the presence or absence of a first upper premolar, the
relative size of the first and second premolars, the size of the
internal cusp of the upper sectorial tooth, the more or less perfect
retraction of the claws, and the shape of the contracted pupil.

Besides these characters, certain details of brain-structure, the
condition of the anterior cornu of the os hyoides, the proximity of
the stomach to the diaphragm, and the relative length of the
intestine, are known to be different in different kinds, and no doubt
various other such divergences exist which have not as yet been
noted. Indeed, these latter anatomical details have been examined
in too few forms to enable them to be yet made use of for purposes
of classification. :

* This line is, however, indicated on one side of the muzzle of a specimen now
living in the Zoological Society’s Gardens.

i 2 tel, A hee Lee) ery 5 rare Fe 6h ve oe

omar. xIt.]J DIFFERENT KINDS OF CATS. 431

The living cats being thus uniform in structure, one alone stands

Bat as markedly distinct. This is the Cheetah—with its imperfectly-

retractile claws and rudimentary cusp of the mner upper sectorial
tooth, its high skull, long limbs and tail, and long metacarpals and
metatarsals. In it also we saw that the first premolar may be
present or absent, but that the second premolar is greatly developed
vertically. Altogether this animal may, as has been said, rank as a
group or genus by itself, the genus Cynelurus, of which genus the
above characters will form the definition. The Lynxes may also, as
we have seen, be grouped by themselves, but they can hardly be
reckoned as forming a distinct genus, although their special geo-
graphical range—being almost entirely creatures of the north
temperate zone—is a noteworthy character.

All the other cats, however, must, without question, be included
in a single genus, Felis. ,

It has been proposed to separate off, as a distinct genus, the cats
with a vertical pupil and an orbit closed behind by bone, and to
divide the round-pupilled cats imto two genera according to the

presence or absence of a first upper premolar. But these characters

are too inconstant to serve such a purpose. We have seen that
in the lion, even the upper true molar may not only be wanting,
but the skull may show no trace of the tooth’s past existence.
But though the genus Fes must be thus extensive, the kinds con-
tained within it may, for convenience, be considered as forming
certain sets, distinguished by trivial marks. Thus the male lion, as
normally developed, is distinguished from all other cats by its large
mane, and the tiger by its vertical stripes and large size. <A few,
as the puma, jaguarondi, eyra, F. aurata, F. planiceps, F. badia,
and J rutila, are separable from the rest by their uniform colour,
but the great bulk of the cats are black-spotted animals A few
also may be distinguished from the rest as rather ‘“clouded”’ than
“spotted.” Such are the F. marmorata, F. macrocelis, F’. megalotis,
F. pajeros, F. caligata, F. Manul, F. neglecta, F. torquata, and
F. catus. Almost every transition, however, exists between the
spotted and the clouded cats, and some spotted forms occasionally
have their spots very slightly marked, so that generic distinctions
reposing on any such characters would be most futile.

Fifty species of living cats have been here enumerated as probably
distinct, but it may turn out that certain of these are mere varieties,
while some forms here deemed varieties may possibly prove to be
really distinct species. It is the South American spotted cats—ocelots
and margays—which are specially difficult thus to determine, and with
regard to the smaller cats of China, and the adjacent parts of Asia,
a similar, though perhaps less degree of difficulty occurs. It may
be that F. Wagati, F. gavanensis, F’. microtis, and F. Jerdoni, will
have to be merged in other species. Nevertheless it may be con-
sidered certain that upwards of forty well-marked species of cats
now exist. ,

§ 14. A much larger number of species have probably existed in

432 THE CAT. (cHar. xn.
the past, most of which have disappeared without leaving any yet
discovered trace of their existence. Some, however, have left theit
remains in caves and superficial deposits, while others are made
known to us by fossil remains. Indeed, a variety of fossil cats
Now ExtTrncr have been described, but as to many of them there is
necessarily great uncertainty, since our whole knowledge of them
reposes upon perhaps a lower jaw or one or two teeth. New fossil
forms are now being so rapidly discovered in North America, that a
complete enumeration of extinct species and a correct appreciation
of their affinities must be a work of the more or less remote future.
From what is already known, there can be no doubt but that
some cat-like creatures, very different from any now living, once
existed.

In the first place, a variety of fossils have been found which
differ from existing cats in no way that would warrant their being
placed in any other genus than Felis. Such are cats that have
been found in the newer miocene or oldest pliocene of the Siwalik
Hills.*

Such, again, are others varying in size from a wild cat to a
hyena, which have been found by Professor Gaudry+t at Pikermi in
Greece, and many of those which were before described by Professor
De Blainville,t and by M. Paul Gervais,§ such as Felis Christolii
(about the size of the Serval).

The great cat known as the so-called “Cave Lion,” Felis Spelea,||
which lived in England in middle and late pleistocene times, is a
well known extinct feline form.

But besides these fossils, thus referrible to the existing genus,
there are a variety of other remains which cannot be so referred.

§ 15. Thus the remains of certain large cats have been found in
pliocene and miocene, and even in eocene deposits, which differ from
any existing cats in the enormous size of their upper canine teeth.
The crowns of these teeth were laterally compressed and trenchant,
with strong serrations along the margins—a character but feebly
developed in any of the large living cats.

Further, the mandible may be widened, from above downwards,
the better to protect such enormously developed teeth. These tusks
were indeed so large in some species that the jaws could not be
opened beyond them so as to allow them to be used for biting. They
could therefore only have been made use of as daggers, the animal
striking with them with its mouth closed. Such forms must be grouped
apart under a distinct generic name—the name Macu#ropus.
This genus had a very wide range, remains of it having been found
in Europe, India, and America, both North and South. In some

* E.g., the Felis cristata of Cautley | Owen, British Fossil Mammals,
and Falconer. p- 161; and W. Boyd Dawkins in
+ See his ‘‘ Animaux Fossiles de l’At- | Paleont. Society, 1869, cxviii.
tique,” p. 116, plate 17. 4 As to this and other geological

t Ostéographie, Felis. _

. terms, see below, Chapter XIV., § 6.
§ See his ‘‘ Paléontologie Frangaise.” .

auap.xt.] DIFFERENT KINDS OF CATS. | 433

individuals of this genus, the first inferior premolar may have but
one root, or may even be wanting altogether, thus carrying the
reduction of lower teeth to an extreme. In the development of the
upper canines the Macherodonts are separated from the general
condition of the cat tribe, not merely in that they were so immense,
but that their length necessitated a peculiar mode of use, so that

Fig. 184.—SKULL oF MACHZRODUS SMILODON.

these creatures may be said to have initiated a new and very special
modification of cat-existence.

§ 16. Another fossil form of cat has been named HopLopHonervs *
by Professor Cope, who represents it as like Macherodus in having
the mandible vertically expanded and the upper canines more or less

largely developed, but as differing from it and from all existing cats
in that the inferior sectorial has a posterior lobe or “heel,” while

the superior sectorial has no anterior lobe, such as that which exists
(Figs. 12 and 46) in all living cats. Its upper molar is largely
developed (Fig. 185, B) and there is no inferior tubercular molar.

It is a miocene genus, founded on fossils from the White Rivers of
Nebraska and Colorado.

* See Annals and Magazine of Natural | logical Survey, 7th Report, p. 509; and
History for January, 1880, p. 39; see | the Proceedings of the Acad. of Nat. Se.
also Bulletin of the United States Geo- | of Philadelphia, July 8, 1879.

FF

434 : | THE CAT.

A long known fossil form, Psrupznurvs* (of which several
species have been described), 1s from the upper miocene of France
and North America. ;

This animal had an additional lower premolar, so that there were

Wyte teen,
ay,
Meh ay

3 ll uy) ica iy
F
95 nut. size
Fig 185.
A Skull of Hoplophoneus oreodontis Cope). B. Grinding surfaces of right upper molar and sectorial.

Grrrrn

I?
MU

iif 4
we AGN

Wo

i aay
} Pi. \y

~

4

i
will ail My i
|

Lie
—
ANiypipjipse74

U7 nat: size.

Fig. 186.—SKULL or Nimravus brachyops (Cope), FROM OREGON

three premolars and one sectorial molar in the lower jaw. The
lower sectorial has but a rudimentary heel.

* Gervais, Paléontologie Francaise, | see also Filhol, in Annales des Sciences
p- 232; see also Leidy’s Mammals of | Géologiques, vol. vii., p. 158. The Felis
Nebraska and Dakota in Journal of | quadridentata of De Blainville belongs to
Academy of Natural Sciences of Phila- | this genus. ,
delphia, vol. vii., p. 52, plate 1, fig 8;

ee
iat”

— | DIFFERENT KINDS OF CATS. 435

§ 17. Another miocene form (as large as the jaguar) has also
Ben described by Professor Cope, under the name Nrwravus. It is
from the vicinity of the White River, Oregon. It is described by its
discoverer* as having the same form of upper and lower sectorial
as Hoplophoneus, but as differing from the latter in that it has an
inferior tubercular molar. The heel to the lower sectorial is large.
The upper canine is very straight and dagger-hke, and the alveolar
border between it and the second premolar is singularly arched.

A very interesting form, called Dryicris,+ has been found in the

ee

Yi nat.size .
Fig. 187.-SKvLL oF Dinictis Cyclops.

““mauvaise terre” of Nebraska, which is certainly miocene if not, as
some geologists think, eocene. It was as large as the Northern lynx.
In this kind tke upper sectorial has no anterior lobe, while the
lower sectorial has a very large bifid posterior lobe or heel, The
mandible also is somewhat widened anteriorly ; but the most inte-
resting character is the presence of a small tubercular molar in the
lower jaw, together with three premolars in front of the sectorial, s
that there are three premolars and two molars on each side.
Another kind has been described by M. Filhol + as Proelurus.
It has one tubercular molar above and below, with tecth very feline
in form. The shape of the skull, however, is not feline, and the
present author is disposed to regard it rather as a creature of the
weasel kind—an opinion in which he is supported by the concurrence

* Ann. and Mag. Nat. Hist., 7. ¢., and + See Annales des Sciences Géolo-

- Pro. Acad. Nat. Sc. Philadelphia, J. ¢. giques, ‘vol. x., p. 192, plate 27, figs. 5,

+ See Leidy’s Mammals of Nebraska | 6, 8-13, and plate 26, figs. 2-11; and
and Dakota, Journal of the Academy of | in the Bibliothéque de l’Ecole des Hautes
Nat. Sc. of Philadelphia, p. 64, plate 5, | Etudes, section des Sc. Nat... Vol. xis
Fig.1-4. The genus of Alurogale of Filhol | 1879, pp. 192-20*
seems to be really the same as Dinictis.

FF2

436 THE CAT.

of Professor Gaudry. It is only therefore here noticed among cat
remains,* because Professor Cope appears to regard it as a primeval
cat, and it certainly does resemble the cats in the shape of the sectorial __
teeth, the upper one of which has the internal cusp—which, however,
we have seen to be wanting in the living Cynelurus.

AN

A NW

10/4 nat. size

Fig. 188.—SKuLL oF Archelurus debilis (Cope), FROM OREGON,

§ 18. A very remarkable miocene fossil, which seems really to have
been a kind of primeval cat, is the genus ArncumLurRus of Professor
Cope.+ This has the usual number of incisors and canines, but has
four premolars and a tubercular molar in the upper jaw, and three
premolars and two molars in the lower jaw. Its feet are very
slender.

The single species of the new genus is described as follows :—
“Mandible, with the anterior face of the symphysis, separated from
the lateral face by an angle which is not produced downwards.
Superior sectorial without anterior lobe;+ imferior sectorial with a
heel. General structure of the jaws, weak; superior canine, small,
little compressed, with an acute posterior edge which is not serru-
late ; first premolar in each jaw, one rooted; second inferior pre-
molar, large; sectorials large; diastemata very short; alveolar
border below the inferior sectorial and tubercular teeth everted,
forming a larze osseous callus, which has a free inferior and pos-
terior margin, the latter rising into the base of the coronoid pro-
cesses: zygomata slender; post-orbital processes little prominent ;
front wide, convex transversely. About the size of the panther.”

This is certainly the most exceptional and uncatlike of all feline

skulls.
* It appears to have had an ali- + The American Naturalist for Decem-
sphenoid canal, and M. Filhol regards | ber, 1879, p. 798a.
it as perhaps allied to Cryptoprocta. As + The upper sectorial appears to me
. to these matters, see the chapter on the | however to have a very large, though
| Cat’s place in Nature, little prominent, anterior lobe.

CHAP. XID}

§ 19. Yet another miocene genus has been described * by Professor
Cope. It is named Poconopon, and its skull is about one-sixth
smaller than that of the tiger. “ The canine is large and compressed,
as in Macherodus, and has serrulate anterior and posterior cutting
edges.”” The symphysis is much widened to protect the canines. It
differs from the Macheenodonts in having an additional inferior pre-
molar tooth. The skull of this animal is singularly elongated, and
there are three premolars in the lower jaw, while the width of the

Fig. 189.—SKULL OF Pogonodon platycopis (Cope), FROM OREGON.

diastema between the upper canine and the first premolar (which
is in place) is such as to seem as if another small premolar may
have existed.

A very curious and exceptional eocene form of cat has been
named Eusmilus.t It differs from all other known felines in having
only four incisors in the lower jaw, and a pair of small canines sepa-
rated by a very long diastema from the next teeth, which consist

only of one premolar and one sectorial true molar. The lower jaw

is enormously widened towards its symphysis to protect the large
upper canines. It represents the characters of a flesh-eating, pre-
dacious animal of the cat-kind, carried out to an extreme degree.
Professor Cope considers Evsmiuvs as forming the culminating deve-
lopment of the Macheyodont type of structure (Fig. 190).
~ § 20. A genus named ilurodon, has been founded by Professor
Leidy ¢ on an upper sectorial tooth found by Dr. Hayden at the
Loup River, Nebraska. It closely resembles the corresponding
tooth of the cheetah in the abortion of the internal cusp.

A genus termed Limnofetis has been instituted § to designate

DIFFERENT KINDS OF CATS. 437

* See the American Naturalist for
February, 1880, p. 143, and for Decem- |
ber, 1879, p. 7986.

+ By M. Gervais in the 2nd part of
his Zoologie et Paléontologic Générales,
1876, pp. 53 and 54, plate 12. See also
Filhol, Recherches sur les Phosphorites
de Quercy, Ann. des Se. Géologiques,
vol. viii., 1877, p. 821, and vol. vii., 1876,

p. 158, plate 28.

iE Journal of the Acad. of Nat. Se. of
Philadelphia ; Mammals of Nebraska,
p- 68, plate ik figs. 13 and 14.

§ American Journal of Science and
Arts, vol. iv., August, 1872. See also
Silliman’s Journal, ard series, vol. iv.,
1872, p. 202.

—— es OO ee eee ee eel

FT er ee ee ee ee ee a «ee Ss Ce

+ PY
_.

more or less preserved. ‘The Coie however, as yet publis
is too incomplete to admit of its place im the cat series—supposi
that it really has a place there—being determined.
The name Zrucifelis* has also been imposed on an upper sectorial |
tooth, which is more like a cat’s milk sectorial tooth than it is 4 :
like the permanent sectorial. It cannot therefore as yet, any more ~
than Limnofelis, be admitted as a recognised extinct member of the a
cat group of animals.
_ Our knowledge of the kinds which have been reckoned as distinct
species (i.e., of the species of the various fossil genera) is too frag- —

Fig. 190.—Part or Lower JAW AND TEETH OF Eusmilus bidentatus. x
A. Right side of mandible. B. Under surface of anterior end of
i a. Socket of lower sectorial. mandible. a
‘ei ¢ Canine. ec. Canine. Yost
i. Incisors. i. The four incisors. be |

mentary to admit of their enumeration, alongside of existing kinds,
Ey, as of equal value. Some four species of Dinictis, five of Pseudelurus,
i ; three or four of Hoplophoneus, two of Pogonodon and two of Nimravus,
4 and at least eleven of Macherodus have been described.

It is not possible to arrange the extinct and existing genera in one
series, but if the cheetah (Cynelurus) and dlurodon be left out, the
rest may perhaps be arranged on either side of Felis (according to
their affinities to it and to each other) in the following order :—

1, Archelurus. 2, Dinictis. 3, Nimravus. 4, Pseudelurus. 5, —
Felis. 6, Hoplophoneus. 7, Pogonodon. 8, Macherodus. 9, Hus-

mulus.
* By Professor Leidy, /. c., plate 28.

ey
aie

Of existing cats, it is the clouded tiger (F. macrocelis) which
most resembles Macherodus, not only by its very long upper canines,
but also by the shape .f its skull. Fels planiceps, with its large
upper premolar, shows a certain affinity towards fossil forms which
have more developed premolar teeth than have any of the exist-
ing cats. : |

As to the fossil cats, in addition to the structural facts already
mentioned, it is important to note that Archelurus, Dinictis,
Nimravus, Pogonodon, and Hoplophoneus agree nm differing from all
existing cats (and from other fossil cats, so far as has been yet ascer-
tained) in that the carotid and condyloid foramina open separately
from the foramen lacerum posterius, and in that the ali-sphenoid
develops a lamina of bone to embrace the external carotid artery,

the aperture left for the artery forming what is called an ali-sphenoid —

canal.* In these respects, however, -Wacherodus smilodon resembles
existing cats.

It is abundantly evident that the differences between any of the
species which now live are very small compared with those which
separate such forms as Archelurus and Eusmilus from existing
species or from one another. Itis the two last-mentioned genera,
together with the sabre-toothed Macherodonts, which exhibit to us
the most extreme and divergent structures as yet discovered, amongst

.. those various widely spread, or long existing, forms of animal life

which can make a valid claim to be considered as belonging to the
great feline group—to be, in fact, some amongst the various *‘kinds
of cats.’’

omar. x] DIFFERENT KINDS OF CATS. 439

vot 2 A ; :
ae mas ree ee eee Pee
Te os ed ee ee a ee ee ee ee ee,

* These facts are mentioned by Pro-
fessor Cope (see ‘‘ American’ Naturalist,”
December, 1880, pp. 834 and 835) in a
paper which has only reached my hands
as these pages are passing through the
press. On account of the differences in
the cranial foramina, -Professor Cope
divides the cats into two families:
I. Felide; II. Nimravide. But the
conditions in this respect presented by
Pseudelurus and Eusmilus have not yet
been described. Moreover, while dis-

posed to admit the claim of Archelurus
to rank as a distinct sub-family did it
stand alone, it seems to me that Djnictis,
Nimravus, Pogonodon, and Hoplophoneus
go far to bridge over the differences
between. it and the other cats, and I
cannot regard the two last-named genera,
as deserving to be ranked in a sub-family
distinct from the bulk of the Felide.
How exceptional is not Otocyon amongst
the Canide !

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CHAPTER XIII.
THE CAT’S PLACE IN NATURE.

§ 1. Noruine can be understood by itself. All our knowledge
consists of apprehensions which have been acquired by comparing
and contrasting one thing with another; and the more we know of
any object, the greater is the number of relations we are able to affirm
to exist between it and other objects. To fully understand any
living creature, then, we should understand, as far as we can, the
various relations in which it stands to all other living creatures:
More than this, we should also understand its relations with that
part of the creation which is devoid of life—in short, we should
understand “ its place in nature.”

But the reader may deem such an inquiry superfluous as regards
the animal which we have elected to study; for any.one who is
asked, “‘ What is a cat?” will at once reply “A beast of a certain
kind which preys on other animals ;” and if again asked “ What is
meant by a beast?” will probably say, “a living four-footed
animal.” If, however, the inquiry be pressed further, and precise
meanings of “ living creature,” “animal,” “beast,” and ‘“ beast of
prey,” be demanded, the unsatisfactoriness of mere vague, popular
conceptions will be plainly shown. We must then endeavour to
obtain a full, clear, and precise knowledge of what is, or should be,
meant by the above terms, so that we may be able to answer the
question, ‘“‘ WHat 1s A cat?” with accuracy, and with a sufficient
comprehension of the expressions employed in so answering. We
must know ‘‘the why and the wherefore” of the terms of our
answer.

§ 2. Now, in the first place, we have seen that the body of the
cat is bounded on all sides by curved lines and surfaces. Secondly,
we have recognised that its body consists of different organs and
tissues, and that wherever we may cut through it, we come upon
parts which differ one from another—its body, therefore, is anything
but homogeneous. A third fact about the cat’s body concerns its
chemical composition. We have seen that a great uniformity exists
in this respect, and that all the main portions of it—its flesh, its
nerves, its blood, &c.—are reducible to oxygen, hydrogen, carbon,
and nitrogen, of which (with the addition of a minute quantity of

car. xm] THE OAT’S PLACE IN NATURE. 441
a few other elements) the whole cat may be said to consist. We
have alsuv seen that these chemical elements are built up into
organic substances of very complex nature (the various albuminous
substances} which make up its flesh and blood, its nerves, &e.

So. much for facts of structure. As regards function, there are
several of the cat’s activities to which attention must here be
redirected. The kitten grows, and the adult cat continually uses up
and replaces, in the wear and tear of life, different parts of its
substance. Both these kinds of “growth” take place, as we have
seen, not upon the surface of the body—ainternal or external—but
in the very inmost substance or parenchyma of that body, by a
process of ‘‘ intussusception.”

But growth needs the presence of certain conditions without
which it cannot take place, because life itself cannot be maintained
without them. The cat, like ourselves, can endure considerable
changes of temperature, but there are temperatures which it cannot
long endure and live—such as much below 32° Fahr. on the one
hand, or near 212° Fahr. on the other. Again, moisture is a
necessity to it, for a very large part of its body consists of water, and
in a perfectly dry atmosphere its existence would soon come to an
end. Besides these conditions, the process of intussusception is not
‘only one which the eat can carry on, but one which it must carry on
if it would continue to exist—the taking in of food is a positive
necessity for such existence. But this food, as we have seen, is
partiy gaseous, and the animal does not take in one gas at its lungs
without at the same time giving forth another in its place. There
is going on, in fact, a process of ‘‘ gaseous interchange,” and without
the continuance of such a process the cat could not itself continue to
be. Finally, we have recognised that the cat-life may be described as
a cycle of changes. Let there be a proper supply of food and good air,
with sufficient warmth and moisture, and the kitten becomes a cat,
which again reproduces (the requisite conditions existing) a kitten.
Every cat, then, possesses an innate tendency to carry on a cycle of
definite and regular changes when exposed to certain fixed conditions.

§ 3. In the structural and functional characters above given,
the cat agrees with all other living creatures, and DIFFERS FROM
CREATURES WHICH ARE DEVOID OF LIFE. All living creatures, not only
all animals, but all plants down to the lowest fungus or alga, agree
with the cat in possessing an innate tendency to carry on cyclical
changes; the flower becomes a fruit, whence comes a new plant,
which produces a flower again, and grows by intussusception. All
need moisture and a certain moderate temperature* for their con-
tinued existence, and all both feed and carry on a process of gaseous
exchange with the medium which surrounds them. All consist
largely of oxygen, hydrogen, carbon, and nitrogen—built up mto
protoplasm—almost all are bounded entirely by curved lines and

* It is suspected that the germs of | troyed by exposure to a temperature of
some lowly organisms may fail to be des- | 300° Fahr.

t
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442 . THE CAT.

surfaces, and all possess a heterogeneous section, for even the lowest
animaleule, when cut through, shows that it 1s composed of a semi-
fluid substance through which granules are diffused.

On the other hand, crystals, and many minerals, present a homo-
geneous surface when cut through, being perfectly alike throughout
their entire substance. A few minerals, such as spathic iron and
dolomite, are, indeed, bounded by curved lines and surfaces; not
only, however, can no such character be affirmed of minerals gene-
rally, but the whole multitude of crystals are actually classified
according to the angles formed by the plane surfaces which bound
them on all sides. No such uniformity of chemical composition,
again, can be affirmed of minerals, as of living’ beings, nor are their
elements built upinto protoplasm. It is true that crystals will grow:
Suspend a small one in a suitable fluid and it will become a large
one; break off the angle of a erystal, and, similarly suspended, it
may replace the part removed by a fresh growth. But such growths
(unlike those of the cat and of all living creatures) are not brought
about by internal increase, but by a mere superficial deposit. Many
mineral substances persist unchanged during variations of tempera-
ture. very far exceeding that between 32° Fahr. and 212° Fahr.
Many, also, can persist in a perfectly dry atmosphere, since they need
no moisture whatever. Such processes also as those of food-taking
and continuous gaseous exchange, are unknown in the non-living,
inorganic world. Finaily, no mineral whatever possesses an innate
tendency to carry on a cycle of definite and regular changes when
exposed to any given conditions. A crystal may, indeed, be arti-
ficially broken up into smaller crystals, which, if suspended, as just
mentioned, will grow externally, and may be again artificially
broken up, and so one crystal may be made to produce others. But
such an action is altogether different from organic reproduction.
No non-living creature reproduces through an innate power, as
every living creature does, or tends to do. |

We see, then, what we implicitly affirm when we say that the
“cat” is “‘ a living creature,” and we may now apprehend certain
very general and important contrasts which exist between it and
the whole inorganic or lifeless world.

§ 4. But an objection may perhaps be made to the above re-
presentation, as follows: “upon the theory of evolution, living
beings first arose spontaneously, in a world which, according to the:
view just stated, would be a world devoid of life. But the law of
continuity forbids the sudden appearance of any phenomenon;
therefore life must have really somehow existed in such a world, and
therefore there is no such distinction between the living and non-
living as that above given.” This objection might he re-enforced by
the following argument: ‘Your cat gives forth ova and sperma-
tozoa; these bodies exhibit such movements and actions as certainly
imply that they are alive. Yet they do not exhibit the main
characteristic above given of living things—for they do not tend to
carry on a cycle of changes when exposed to certain fixed conditions.

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Under no circumstances will ova directly reproduce ova, or sperma-
tozoa, spermatozoa. Such bodies are in this respect like the first living
creature, which spontaneously arose. At that early period the earth’s
condition was such as to favour spontaneous generation, and there-
fore no reproductive agency was needed beyond that which naturally
existed in the matter whence such organisms sprang. They therefore
neither needed nor possessed reproductive power. Only with the
fading away of this earlier terrestrial condition were such creatures
as began to possess a reproductive capacity favoured in the struggle
for life, and thus by degrees reproductive power became first frequent
in organisms, then general, and now universal.’’

Let us consider first the argument by which the above objection
has been re-enforced. To it we may reply : Great as is the difference
between a cat and a cat’s ovum or spermatozoon, yet if the whole
animal series is considered, a variety of forms will be met with
in which larger and larger portions of what we justly take to be
true animals are thus detachable and detached. Indeed, at last we
come to creatures * in whom the cycle of life is, as it were, so split
up, that it is difficult to say which of the creatures that successively
appear between one fertilised ovum and another, is to be reckoned
as the more perfect animal. Yet all these creatures are living, and
all tend to-carry on a definite and regular cycle of changes when
exposed to certain fixed conditions. The very same, then, may be
said of the cat’s ovum or spermatozoon. Like the intermediate

forms of the life cycle of many lowly creatures, they also, though

they do. not themselves tend to “ undergo ” the whole cycle of changes,
yet possess an innate power and tendency to initiate, produce, and
“carry on” that cycle in which they themselves play an important
part, and by which their own forms are indirectly reproduced.
Therefore there is no real parity between these elements and
hypothetical primordial animals, naturally altogether devoid ot
innate reproductive capacity. No such creatures are known to exist
now. To believe that such ever existed would therefore (in the
absence of any positive evidence of their past existence) be at once
both gratuitous and contrary to experience ; yet experience is the
admitted source of all our knowledge!

Having disposed of the re-enforcing argument, we may now con-
sider the original objection itself. This objection is the real ground
upon which a belief in the original existence of non-reproductive living
beings rests, namely, an d priori necessity reposing on a now pre-
valent conception as to the “law of continuity.” That law, we are
told, “forbids the appearance of any new phenomenon.” We reply
—so much the worse for that law. The existence of breaks, gaps,

and new beginnings, is a manifest truth which cannot be denied

except by playing tricks with language—using words in non-natural
senses—and by ignoring the differences and paying attention only
to the resemblances which exist between different things. The

* £.g., certain jelly-fishes, certain tunicates, and certain worms.

444

THE CAT.

foolishness of this kind of reasoning will not really be exaggerated
if it is represented by an argument such as the following patently
fallacious one: “ A cat is an entity, a dream is an entity, therefore

a cat is a dream.’’*

* This folly is well pointed out by the
late G. H. Lewes. in the second chapter
of the second problem of his third series
of‘ Problems of Lifeand Mind.’ He says :
**Psychologico-metaphysical speculation,
untrammelled by the distinctions of sen-
sible experience, easily arrives at Pan-
psychism. The hypothesis rests upon
an arbitrary extension of terms, and upon
an exclusive selection of one order of
conceptions. By a sufficient elasticity
of terns we may easily reduce ali diver-
sities to identity ; all things are alike if
you disregard their points. of unlikeness.

. . Stretching terms, it is easy to
identify life with molecular change, and
then conclude all things to be living.
But the biologist must protest against
such manipulating of conceptions. For
him life expresses ‘a vast class of pheno-
mena, never found except in definite
groups of substances, undergoing definite
kinds of molecular change. The crystal
is not alive, because it does not assimi-
_ late, reproduce itself, and die. . . . Any
one choosing to stretch terms may say
that molecules live because molecules
exist. But in that case we shall have to
create a new term for the mode of exist-
ence, which is now called life.
Playing such tricks with language, we
may ask : Why should not a lamp-post
feel and think, since it is subject to
molecular changes consequent on im-
pression? Why should not a crystal
calculate? Does not oxygen yearn after
hydrogen? Has not hydrogen the pro-
perty of humidity? These questions
seem absurd, yet they are only naked
presentations of what some philosophers
have clothed in technical terms, and
their readers have accepted with con-
fidence. . . . And why this reliance on
the law of Continuity? That law is
simply a deduction from the conception
of Quantity, abstracted from Quality by
mathematical artifice ; it is one abstract
idea of existence irrespective of all con-
crete modes of existence. It hasits uses ;
but note, first, that it is an ideal construc-
tion, not a real transcription ; secondly,
that not only is it an ideal construction,
which once formed becomes a necessity
of thought, although it is detached from
and contradictory of real experiences, it
is also in the very nature of the case only
applicable to abstract existence ; and not
to concrete modes of existence. See how
these considerations nullify the applica-

tion of the law to the gradations and
diversities of organic phenomena. If
Continuity is a necessity of thought,
not less imperiously is Discontinuity a
necessity of experience, given in every
qualitative difference. The manifold of
sense is not to be gainsaid by a specu-.
lative resolution of all diversities into
gradations. Experience knows sharply-
defined differences, which make gaps
between things. Speculation may ima-
gine these gaps filled, some unbroken
continuity of existence linking all things.
It must imagine this, because it cannot
imagine the non-existencecoming between
discrete existences. . . . Turning from:
the metaphysical to the biological con-

sideration, it is plain that the charac-

teristic phenomena observed in organisms
are not observed in anorganisms; and
even in cases where a superficial appear-
ance seems to imply an identity, an in-
vestigation of the conditions shows this
not to be so. The actions of a machine
often resemble certain actions of an
organism. But when we come to under-
stand how both are produced, we under-
stand how the products are really very
different. We deny that a crystal has
sensibility ; we deny it on the greund
that crystals exhibit no more signs of
sensibility than plants exhibit signs of
civilization; and we deny it on the
ground that among -the conditions of
sensibility there are some positively
known by us, and these are demonstrably
absent from the crystal. It is in vain to
say sensibility depends on molecular
change, therefore all molecular change
must in some degree be sentient change ;
we have full evidence that it is only
special kinds of molecular change that
exhibit the special signs called sentient ;
we have as good evidence that only
special ageregations of molecules are
vital, and that sensibility never appears
except in living organisms, disappearing
with the vital activities, as we have that
banks and trades’ unions are specifically
human institutions. On the first head ;
that of evidence, we must therefore pro-
nounce against the hypothesis of pan-
psychism. How about its philosophic
advantages? To some minds eager for
unity, and above all charmed by certain
poetic vistas of a cosmos no_ longer
alienated from man, the hypothesis has
attractions. But while its acceptance
would introduce great confusion into our

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CHAP, XIII. |

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THE CAT’S PLACE IN NATURE. 445

But because the plain evidence of our senses compels us to deny
that life actually exists or ever did exist in non-living matter, it
by no means follows that life was not potentially present in it. But
“potential existence” is not “an actual existence of a latent kind.”
The expression merely means that conditions exist in matter such that
by the action upon it “of influences externai to it life will arise within
it—life not previously present in a latent state, either in the matter
or in the influences the action of which on matter produces it. Con-
sequently a belief in such spontaneous generation in no way destroys
the greatness and sharpness of the distinction which exists and must
always have existed between the living and non-living worlds.

§ 5. The contrasts which exist, then, between the cat, consSIDERED
MERELY* AS A LIVING BEING, and the mass of non-living inorganic
things may be summed up as follows:

(1) Itis bounded by curved lines and surfaces.

(2) Its section is heterogeneous.

It consists almost entirely of oxygen, hydrogen, carbon, and

nitrogen, and largely of protoplasm.

(4) It grows s by intussusception.

(5) It needs a ‘certain moderate heat.

(6) It needs definite supply of moisture.

(7) It needs food.

(8) It effects a process of continued gaseous interchange.

(9) It tends to carry on a cycle of changes when “exposed to

7 certain fixed conditions.

§ 6. We have next to consider what we mada when we say that
“the cat is an ANIMAL.’

Very obvicus are the characters which distinguish it from plants
generally. It is actively locomotive, possesses feelings and in-
telligence, is of a very different shape, never reproduces by budding,
and, in feeding, it takes its food into an internal + cavity, its

conceptions, and necessitate a completely |

new nomenclature to correspond with the
established conceptions, it would lead
either to a vague mysticism enveloping
all things in formless haze, or to a change
of terms with no alteration in the con-
ceptions. By speaking of the souls of
the molecules we may come to talk of
the molecules as men ‘writ small ;’ we
may assign our controversial passions to
the torrent, and our dogmatic serenities
to the summer sky ; we shall see volition
in the magnet, and contemplative effort
in morphological changes. If we escape
this, and regard the life and sentience of
inorganic bodies as only the lowest and
simplest stage of consciousness, indis-
tinguishable “from what we now call

- motion except that it hasan infinitesimal
quantity of consciousness ;

and if from
inorganic bodies we pass to ’simple organ-
isms, from these to organisms more ‘and
more complex, the soul enlarging with
each stage of evolution ; well, then we

are returned once more to the old point
of view ; the broad lines of demarcation,
which our classifications fix, remain un-
disturbed, and all the modes of existence
known to science are recognised as such.
Into this scientific system the meta-
physical conception of uniform existence
has obtruded itself and borrowed scientific ©
terms ; but the obtrusion is a confusion,
not an illumination.”

* “Merely as a living being,’’ because
of course a practically infinite number of
distinctions exist between such an animal
as the cat considered by itse/f, and non-
living creatures, ¢.g., no mineral has hair,
or a brain, &c.

t A cavity, that is, practically in-
ternal, for in fact, as we have seen,
the cat's stomach being but a prolonga-
tion inwards of its exterior, is ‘‘ morpho-
logically” outsid2the animal. The space
within each pleura or within the peri-
toneum is really internal.

stomach, where it is digested. Moreover, if we analyse the cat’s
tissues we shall find they are almost all nitrogenous, such as muscle,
nerve, and blood, whereas plants, though containing protoplasm, yet
largely consist of a non-nitrogenous substance termed “ cellulose,”
and contain much starch. But we have to seek for distinctions
between the whole world of plants, and the cat considered merely
as an animal, and therefore for such distinctions as all other
animals share with it. Now the above given distinctions as to
motor power, sensitivity, external form, mode of reproduction,
manner of feeding, and chemical composition, serve very well to
distinguish the bulk of animals from the bulk of plants, but when we
come to examine the most lowly organised plants and animals all
these distinctions seem to fade away.

Thus, with respect to motor power, very little difference can be
perceived between some of the lowest aquatic animals and plants,
both of which may be compared to a detached fragment of the cat’s
ciliated epithelium, since they consist of a few cells which protrude
protoplasmic threads, the lowly organism propelling itself about by
the lashings of such threads. Other animals of considerable com-—
plexity of structure—such as some of the Tunicates—adhere to rocks,
and appear quite motionless, save when touched, and then they
eject water from two apertures, thus showing a motor power com-
parable with that of the squirting cucumber. But there are animals
still more inert, such as the bladder-worms, or hydatids, which lie
hidden in the flesh (or other parts) of the animals they infest, and
which are little more than small membranous bags enclosing an
albuminous fiuid. On the other hand, various plants show consider-
able motor power, such as the sensitive plant, Venus’s fly-trap, and
others. ,

The last named organism serves to show us also that a high
degree of impressionability may be present in plants, though we
have certainly no evidence that any of them possess “ feeling.”
But a multitude of the lowest animals seem to exhibit no more signs
of sensibility than do the lowest plants. The hydatids, just referred
to, may serve as an extreme instance of such apparent insensibility.
Hydatids, however, are creatures in an imperfect stage of their
development, the adult stages of which (tape-worms) do give evidence
of a power of sensation. So that sensitivity may be potentially
present in these hydatids as it is in the cat’s ovum, which certainly,
itself, gives no evidence of, nor can be supposed to possess, any
actual power of feeling. On the other hand, such plant-movements
as those referred to, are explicable in an altogether different way
from the sensori-motor movements of animals, while we have no
ground for attributing to them potential sensibility,.since under no
conditions does it ever become unequivocally actual.

As to external form, no distinction can be drawn between some of
the lowest algae or fungi on the one hand, and the lowest animals on
the other, whilst many zoophytes and some other animals, exhibit
the branching mode of growth common in plants; while some plants,

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‘CHAP, XIII]

THE CAT’S. PLACE IN NATURE. 447

as the melon cactus, are not arborescent, but assume a spheroidal
figure.
As to modes of reproduction, no absolute distinction can be

_ drawn between plants and animals. For many animals reproduce

by budding (as do zoophytes), and some may even be propagated by
cuttings. Thus if the Hydra, or the common sea-anemone (Anthea),
be bisected, each half soon grows. into the perfect form once more,
and many worms (such as Seyllis and Catenula), and animalcule
called Infusorma, habitually multiply by self-made sections, 7.¢., by
spontaneous self-division or “fission”? Not only, moreover, is
sexual reproduction as universal amongst plants as amongst animals,
but even male mobile filaments, closely resembling spermatozoa, are
developed by very many flowerless plants.

As to the different modes of feeding practised by plants and
animals, imbibition is indeed (as has been said) universal with the
former. But then the digested insects made use of by Drosera and

_ Dionea may be said to be taken into a temporary quasi-cavity, while

in certain other plants the receptacle has the form of a permanent
sac. This is the case with the curious pitcher plant (Nepenthes), in
the pitchers of which insects are caught and decomposed, probably to
the profit of the plant.* But not all animals take solid food into an
internal cavity or stomach. Many can only imbibe it through the
outer surface of their bodies. It is thus that tape-worms (which le
perennially bathed in a fluid medium unceasingly nutritious) feed.

Lastly, we come to the distinction between animals and plants as
regards their chemical composition. Now it is true that most plants
are less nitrogenous than are animals. But this cannot be affirmed
of the great group of Fungi. Moreover, substances which were long
deemed peculiar to the vegetable kingdom, are now known not to be
so. Thus, “starch,” e.g., has been found even in the human brain ;
while “cellulose ”’—the principle of wood—exists in the tough
external coat which imvests the bodies of the Tunicates before
referred to.

Thus all the foregoing six distinctions break down with respect to
a considerable number of animals or plants, though they may serve
to separate all the higher forms of the two kingdoms of living
beings.

Other distinctions, however, exist which have a greater value, and
may be conjointly made use of in discriminating almost all plants
from all animals. Of these there are two—the first (A) relates to
structure ; the second (B) relates to function.

A. It has been already said that every living organism consists of

a substance called protoplasm, with which other substances (some
nitrogenous, some non-nitrogenous) may co-exist. Amongst the
non-nitrogenous occasional accompaniments of protoplasm 1s
“cellulose.”

* The structures referred to are curious pitcher-like productions which are formed
at the end of foliage leaves.

448 THE CAT,

Now, all plants, except the very lowest, have their constituent
protoplasm divided into a number of minute separated parts (or
cells), each such separated part being enclosed with an
envelope of cellulose. But in no animal whatever does this
obtain.

There are, however, lowly animals and plants whieh consist
each of a single particle of protoplasm, but almost all unicellular
plants are enclosed within a cellulose envelope—an investment
which is wanting in such lowly animals. In regard to structure
then, we have thus an almost complete distinction between all
animals and almost every single plant.

B. As regards Sunetion, there is a still more important distinction.
The cat’s body is, as we have seen, reducible to a certain
number of chemical elements. Let a living cat be supplied
with these same elements, in whatsoever combinations artificially
produced, and in the greatest abundance, and the animal will
none the less starve to death, however much it may eat of such
substances. For the cat possesses no power of building up its
tissues from inorganic matter, but absolutely needs for its sub-—
sistence a food consisting of organic matter already formed. It
may be said that such is the case because the cat is a beast of
prey. But it is the very same thing with the mice, young
‘abbits, or grain-eating birds, on which the cat may live.
None of these vegetable-feeding creatures can, any more than
the cat, live upon the morganic world exclusively. Nor can
other animals, however lowly, do so, for though a few worms
have an exceptional power in this respect, yet even they also
feed, hike other animals, upon organic matter. Thus it may be
affirmed that the eat agrees with every other animal in not being
able to sustain itself by forming living matter (or protoplasm)
from the morganic world alone. With most plants it is far
otherwise, they can live upon inorganic matter only, and have
the power of dissolving the carbonic acid of the atmosphere,
and retaining its carbon while letting its oxygen go free.

It is by the exercise of this power that all the wood which exists,
and all coal (which once existed as vegetable substance) have been ,
produced. Still, not all plants possess this power; for the group of
fungi, together ‘with such parasitic plants as are devoid of green ~
foliage leaves, require, as animals do, organic matter for their food,
and have not the power of thus fixing carbon.

The cat then, inasmuch as it is an ANIMAL at all, differs from
almost all PLANTS :—

(1.) In that it needs organic matter for its food, and

(2.) In that the protoplasm of its body is not enclosed or parti-
tioned by a structure of cellulose.

But in that it is not an animal of a lowly kind, it further differs

from almost all plants :—

(1.) In its power of locomotion ;

2.) Its sensitivity ;

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3

cmar.xm] THE CAT’S PLACE IN NATURE. 449

(3.) Its non-arborescent external form ;

(4.) Its incapacity for reproducing its kind by a process of budding;

(5.) Its habit of receiving its food into an internal cavity, and

(6.) The more nitrogenous nature of most of its tissues.

As to the pomts in which the cat resembles plants, it of course
agrees with them in all those characters by which it is distinguished
from non-living, organic matter. It also further agrees with all
plants, and also with all animals, in that at one stage of the cycle of
life it is represented only by a minute spheroidal mass of protoplasm
—the ovum or germ.

§ 7. The cat having heen thus compared with the inorganic
world, and with the world of plants, our next endeavour should be
to ascertain its POSITION AMONGST ANIMALS. ‘To be able to do this,
however, it is necessary to be acquainted with the mode in which
animals are classified ; for the number of their kinds is so prodigious
that it would be perfectly impossible to comprehend them without
the assistance of a well-arranged sysTEM OF CLASSIFICATION—a system
which may enable the student to conceive of different animals in masses,
such masses being arranged jn a series of groups, successively smaller

and more and more subordinate. Animals, like plants, are con-

sidered as members of one great group, which has been fancifully
termed a ‘“ kingdom ’”’—the animal kingdom containing all animals,
as the vegetable kingdom contains all plants. The principles adopted
by both zoologists and botanists in subdividing these ‘“ kingdoms”
are “morphological.” By this term it is meant that the characters
upon which these classifications repose, and by which the various
subordinate groups are defined, are characters taken from the shape,
number, structure and mutual relations of the parts of which the
various creatures so classified are built up, and not upon what such
parts do—the characters refer to “structure,” not to ‘‘ function.”
Phe kingdom of animals is divided into a variety of sub-hkingdoms,

each of which is, of course, a very large group of animals indeed.

Each sub-kingdom is again divided into subordinate groups termed
classes. ach class is again divided into orders. Each order is
further subdivided into families ; each family into genera, and each
genus into species; while a zoological ‘ species”? may be provision-
ally defined as “2 group of living organisms which differ only by
inconstant or sexual characters.’’ Sometimes, when a family contains
a great many genera which differ one from another in such a way
that they can be arranged in sets, then the term “ swb-family”’ is
given to each such set. Similarly, different sets of families may be
grouped together (it may be only one family in one set and the rest
im another), and then the term “ swb-order”’ is employed to denote
each such set of families. Similarly here and there the term “ sub-
class’’ may be conveniently employed for groups of orders, and
lastly, sets of classes may sometimes be conveniently united as a
province. Thus in one sub-kingdom we may merely meet with
classes, orders, families and genera, while in another we may meet

_ with provinces, classes, sub-classes, orders, sub-orders, families, sub-

GG

‘i

450, | THE CAT. [cHap. xu.

families and genera. ach of these groups 1s in all cases defined (as
before said) by the common structural characters which the creatures
included within it possess. The groups become successively smaller
and smaller (in the number of species they contain) as we descend
from any sub-kingdom through its classes and orders to its families
and genera. In other words the groups become successively smaller
in their extent. In each case the technical name given to a group
denotes the animals contained within it, and connotes the common
characters which pertain to the group. Obviously then, the larger
and more primary the group, the greater the number of kinds
denoted by it (¢.e the greater its extension), and the Jess the number
of common characters connoted by it (¢.e. the less its intension).
Obviously also, the ultimate groups, e.g. “species,” have the least
extension, but imply, or connote, the greatest number of common
characters, 7.e. they have the maximum of intension.

§ 8. Now the animal kingdom (as generally understood) is
divisible into eight sub-kingdoms, apart from that to which the
cat belongs. Thus there is the sub-kingdom (I.) Hypozoa, which
includes all the lowest, so called, animals, such as Amcebee, Foza-
minifera, Radivlaria and Flagellate animalcules—together forming
the Rhizopoda—with the lowly parasites called Gregorinida, and
all Infusoria. (II.) Secondly, there is the sub-kingdom of
Sponges, Sponerpa. Next comes (III.) the sub-kingdom which
includes the Hydra and Sea-anemone, together with all Jelly-fishes,
Sertularians, coral-animals and such creatures as Beroé and the
Cestum Veneris. This great sub-kingdom is that of the C@LENTERA.
Then there is (IV ) the sub-kmgdom Ecutnoperma, which includes
the star-fishes, sea-urchins (or sea-eggs), brittle-stars and the sea-
eucumbers, some of which are known as the Japanese edible,
“Trepang.” Next (V.) comes the very numerous sub-kingdom of
Worms, VermeEs, amongst which are to be reckoned not only earth-
worms, leeches, sea-mice and tube-worms—these four forming the

Annelids—together with tape-worms and thread-worms; but also
the flukes (or Zrematoda), the Turbellaria, the Bryozoa (or Polyzoa),
the wheel-animalcules (or Rotifera), the singularly primitive worm

Dicyema,* together with Balanoglossus (type of the Enteropneusta)
and the active marine Sagitta, with worms allied to the Echino-

derma and called Gephyrea. Then we have (VI.) the sub-kingdom

Arturopopa, largely exceeding, in the number of its species, all

other sub-kingdoms put together. It includes the crabs, lobsters

and shrimps, the centipedes and millipedes, the spiders, scorpions,
tics and mites, and all the vast multitude of Insects. We have also
(VIL) the sub-kingdom Monuusca, containing all the cuttle-fishes,
pteropods, snails and whelks, oysters, scallops, &c., with the curious
lamp-shells. Lastly we have (VIII.) the sub-kingdom TunicatTa,

containing the seemingly senseless forms already noticed as Tunicates,

with a number of other species; all of which are often called Ascidians.

* Described by Prof. E. Van Beneden, ‘*Recherches sur les Dicyemide.” It may
Bull, Acad. Belg. xliy xlii,, 1876, | be the type of a distinct sub-kingdom,

=

qe eee ee ee ee ee ee ee Tle
™ “}

CHAP, XIII.]

4

THE CAT’S PLACE IN NATURE. 451

Let us now revert for a little time to some cf the facts we have
reviewed as to the cat’s structure, selecting certain characters
(for reasons which will shortly appear,) and viewing them in the
most general way. We have, in the first place, seen that the cat's
supreme and governing set of organs, the central part of the nervous
system, runs along the back of the animal enclosed in a special tube,
which is separated from the more ventral part of its body by the
vertebral centra. We have also seen that the central part of its
circulating system les above its sternum in the ventral part of its
body, with the alimentary canal running between it and the spinal
column. ‘The anterior end of that canal we have also seen to end
at the mouth, which is placed on the ventral side of the brain. The
limbs we have noted as consisting of two pairs, neither more nor
less, each supported by a solid internal skeleton. No prolongation,
however, of the body cavity or of the alimentary canal enters any of the
limbs. We have also seen that its blood 1s red, and that a portion
of the blood, on its way back to the heart, undergoes a secondary,
“vortal,” circulation in the liver. The mouth we have found to be
bounded by jaws placed one above, the other below—and not laterally,
or right and left. In development we have recognised that the first
sign of the embryo is a longitudinal groove, beneath which a
“chorda dorsalis ” is formed, while visceral clefts and arches are
temporarily developed on each side of the pharvnx—the visceral
arches taking part in the formation of the jaws. The above charac-
ters are characters all of which the cat shares with a certain number
of animals not yet here referred to; namely, with fishes,* frogs, and
toads, reptiles, birds and beasts, and lastly, with ourselves also.
These creatures together make up another (the ninth and last,) sub-
kingdom of animals, the sub-kingdom VERTEBRATA—s0 called because
all the creatures which belong to it possess a spinal column, or
backbone, made up im most cases (as we have seen it to be in the
eat) of a chain of spinal bones or vertebree. The cat then is one
of the group (Sub-kingaom) of “ backboned animals.” All these
vertebrate creatures possess a fundamental agreement in organization
with the cat, though, as we shall see, they present various and very
different degrees of minor structural divergence from it. But the
creatures which belong to the other eight sub-kingdoms, though they
ereatly vary inter se, yet all agree to differ fundamentally from the
type of organization presented by the Vertebrata. On this account
they are often conveniently spoken of as one whole, under the name
Invertebrata—although they cannot be united into one group by any
positive characters which are not applicable to all animals whatso-
ever. ‘That we may be able the better to appreciate, by contrast,
the value of these vertebrate characters which thus exist in the eat,
—the presence of which is implied when we say that the cat is a
backboned animal—it may be well to shortly glance at the organiza-
tion of one or two of the Invertebrata.

* There is one fish (the Amphioxus or | ganized than any other vertebrate animals

lancelet) which is much more lowly or- | —as will be pointed out later on.
G G2

452 THE CAT. ote So

Taking then the Lobster as an example of the Arthropoda, we
find it to be a creature the body of which is different indeed from
that of a beast, bird or fish. Instead of an internal skeleton, we
find it has a skeleton which is external. Moreover the calcareous
portions of this external skeleton are moved (as so many levers, one
upon another) by muscles, as in the cat, but then these muscles do
not, as in the cat, clothe the skeleton externally, but are enclosed
within it. Instead of a body the segmentation of which only
reveals itself internally (by the backbone and ribs), and which is but
slightly manifested externally (by at most two pairs of serially —
homologous limbs), we find in the lobster a body consisting in great
part of externally visible segments, which it is plain are serially
homologous, and which are provided with numerous pairs of limbs,
which are also serially homologous one with another. Instead of a
pair of jaws biting vertically, and derived from special modifications
of the body-wall—i.e., from the visceral arches—we find a number
of jaws arranged in pairs and biting laterally, and which are really
limbs modified in a special manner. Instead of a frame made up
of two super-imposed cylinders, with the circulating centre ventral
and the nervous centre dorsal, we find a frame consisting of a single
cylinder, with the heart placed dorsally and the central part of the
nervous system extending from before backwards on the ventral
side of the single cylinder—while there is nothing answering to the
cat’s spinal column. Again, in the lobster the alimentary tube,
instead of bending away from the nervous centres at its anterior
end, not only bends towards them, but actually traverses them.
There are arteries and veins, but there is no portal circulation. The
organs of sense are also very different from the cat’s. The lobster
has indeed a pair of eyes and also a pair of ears, but these are
situated on, or in, modified limbs and not in the head, and the eyes
have not various parts which exist in the cat, while the rods and
cones of the retina are placed at the surface and not at the deepest
layer of that membrane. In development, we have no such medul-
lary groove, becoming a tube, as in the cat (though the nervous
centres are still formed from epiblast,) nor do visceral clefts or —
arches ever arise; moreover it is the ventral, not the dorsal, surface

of the embryo which first appears.

As the type of another sub-kingdom, that of the Mollusca, we
may select the Cuttle-fish, which exhibits a form as different from
the cat, as is that of the lobster, but also one as different from that
of the lobster as it is from that of the cat. For the cuttle-fish has
a large soft body, destitute both of the hard envelope of the lobster
and of the internal, axial and appendicular skeleton of the cat, and
consisting of a fleshy bag, at one end of which is a head, witha
pair of large eyes and ten fleshy processes, or “ tentacles,” radiating
from the terminal mouth of the bag. The body shows no serial
segmentation, either externally, as does the lobster, or internally, as
does the cat, Neither does it show, like both these animals, an
elongated nervous axis, but instead, certain nervous ganglia (whence

ouap. xm] THE OAT’S PLACE IN NATURE. is)

nerves radiate,) aggregated near the mouth and surrounding the
alimentary tube. It has eyes, indeed, which are very like the cat’s,
vet the rods and cones of the retina are placed as in the lobster.
There are no limbs laterally arranged in pairs, as in the cat and
lobster ; and though it has a pair of jaws, they are no more modi-
fied limbs—like the lobster’s—than they are modified visceral arches
—like the cat’s; for such arches are not formed in its development,
any more than are a medullary tube and a notochord.

The lobster and cuttle-fish are examples of the most highly-
organized sub-kingdoms which make up the Invertebrata, but some
species of a sub-kingdom which is in most respects inferior, yet
present certain noteworthy approximations to cat-structure. The
sub-kingdom referred to is that of the Tunicata. Some of these
Ascidians are marine animals, with a leathery coat, or “test,” shaped
somewhat like a bottle with two short necks. Such a creature is
alike devoid of anything, either im the shape ofan external limb or of
an internal skeleton. Its nervous system consists of little more than a
ganglion, while (as in a multitude of Invertebrata of different kinds,

- both male and female sexual glands co-exist in each individual.

Such is its adult condition. Yet during its growth it possesses a
medullary groove that becomes a dorsal tube developing the nervous
centres, which are temporarily in the form of an elongated axis;
while beneath it a structure 1s formed which closely resembles the
chorda dorsalis of the cat’s embryo. It is only in some Tunicata,
however, that this condition temporarily obtains, though in all, the
nervous centres are dorsal in position and origin. ‘There are no
visceral clefts and arches as in the embryo cat, yet-a number of
serial openings are formed on each side of the pharynx, which
persist throughout life, and through which water is propelled by
the lashings of vibratile cilia.

All the creatures yet mentioned resemble the cat, inasmuch as
they exhibit either a serial or a bilateral symmetry, or both.

But there may be another form of symmetry (entirely absent in
the cat,) namely, a radial symmetry, which is exhibited by jelly-
fishes, sea-urchins, star-fishes and others.

In various Invertebrate sub-kingdoms, various forms of organic
inferiority are found. Some animals grow up in compound
aggregations, as do so many of the Celentera. These last-named
animals have a certain interest for the student of Cat embryology.
We saw that in the fertilized ovum of the cat, yelk division ended
in the formation of two layers—one superficial layer of epiblast,
with a hypoblastic layer beneath it. ‘Amongst the Cclentera we
find animals whose whole body, through their whole lives, consists
only of two corresponding layers: an external layer, the “ ecto-
derm,” aud an internal layer, the “endoderm;” the endoderm
(ike the embryonic hypoblast of the cat,) lining the alimentary
cavity. These resemblances are not merely fanciful, for the condi-
tions, which exist in a multitude of intermediate forms, show that
there is a real affinity of nature between these corresponding parts

454 THE CAT. [oHaP. xm,

of these so widely different animals. Amongst the lowest animals
of all—the Hypozoa—we find conditions which remind us of still
earlier stages of the cat’s existence, and also of fragmentary portions
of its adult frame. Amongst those lowly parasites the Giregorinida,
are animals which consist only of a spheroidal particle of protoplasm
enclosed in a cell-wall and containing a nucleus and nucleolus—quite
comparable therefore with the cat’s ovum. Amongst other lowly
creatures called Flagellata, some consist of a small spheroidal particle
of protoplasm, with a filamentary prolongation, or tail, by the
lashings of which the little creature propels itself along. Such
organisms are evidently comparable with the cit’s spermatozoa.
Yet other lowly organisms amongst the hizopoda consist of par-
ticles of protoplasm which slowly change their shape in an altogether —
irregular manner, and which quite resemble the white corpuscles of
the cat’s blood. Such animals are called Amcebde, and it was with
reference to them that the motion of these blood-corpuseles was
spoken of as “ amceboid,” or “ amcebiform.”

But these creatures have a further interest for us. Each Ameeba
feeds both by imbibing nutritious fluid and by actually engulphing
within its substance undissolved nutritious particles, and this process
is comparable with what must take place.in the nutrition of the
protoplasmic particles which form the ultimate parenchyma of the
eat’s body. Again, each Amoeba effects a gaseous interchange with
its surrounding medium, gives out carbonic acid and takes in oxygen,
and this process is directly comparable with that intimate and
internal process of respiration before described as taking place
throughout the particles of the cat’s parenchyma. Finally, many
of these lowly animals have the power of secreting within their
unicellular bodies and extruding from them various formations of
different kinds, and this process is also comparable with the like
actions of the epithelial cells which line the ultimate gland-tubules
of the cat, and also with that universal process of minute and
ultimate excretion which is carried on by the particles of its ultimate
body-parenchyma.

But the whole of the sub-kingdom Hypozoa has also an interesting
resemblance to the embryonic condition of such an animal as the
cat at a period anterior to its differentiation into distinct tissues.
For all the Hypozoa consist either of single cells or of more or less
simple aggregation of cells, and in no hypozoon are these collected
and differentiated into tissues—not even into an epiblast and hypo-
blast—conditions which appear for the first time in the sub-kingdom,
Spongida.

§ 9. Inasmuch, then, as the cat is a BACKBONED ANIMAL, 1t may
be said to differ from the whole of the INVERTEBRATA in the follow-
ing points :—

(1) Its body consists, in the adult as well as in the young con-

dition, of two unequal antero-posteriorly elongated cylinders
—one placed dorsally, the other ventrally.

4 Aue 7

omar. xm] THE CAT'S PLACE IN NATURE. 455

(2) The central part of the nervous system is, throughout life,
an elongated structure in the dorsal cylinder.

(3) The two cylinders are, throughout life, separated by an
elongated solid structure—the vertebral bodies or (in the

P foetus) their cartilaginous or soft representative.

f (4) The heart is placed on the ventral side of the thus separated —

< off ventral cylinder.

4 (5) The anterior end of the alimentary canal bends down away

5 from the nervous centres.

f (6) Limbs being present,* they are neither more nor less than four,

" and have an internal skeleton wrapped round by muscles.

(7) There is a portal circulation.

(8) Jaws being present, they are formed from visceral arches.

Were it not for the existence of a very lowly-organised fish, the
Amphioxus or lancelet, on the one hand, and of the tunicates above
referred to on the other, additional distinctive characters to those
just given could be drawn out. For the lancelet has no distinct
skull, head, brain, auditory organs, chambered heart, or parts
formed from visceral arches, such as those we have made acquaintance
with. The cat then, as a backboned animal, of a type superior to
the lancelet, differs from all Non-Tunicate Invertebrata, not only in
the above enumerated characters, but also in that :

(1) Its body is doubly cylindrical at any time of life ;

(2) Its nervous centres are an elongated dorsal axis at any time

of life ;

(3) It has a vertebral column ;

(4) It has a brain enclosed in an anteriorly expanded part of the

dorsal cylinder, 7.e., in a skull ;

(5) It has mandibular and hyoidean arches;

(G) The first sign of the embryo is a medullary groove where the

nervous centres take origin ;
; (7) Visceral clefts and arches are formed.
; § 10. Such being the relations borne by the cat as a backboned
animal to all the creatures which form the Invertebrate sus-
KINGDoms, the next point to examine is its relations to its fellow
Vertebrates.

Now the sub-kingdom Vertebrata consists of three ProvincEs and
five cLASSEs as follows :—

It consists of the province ZyGENCEPHALA,t containing one class
only, the class Mammaha, which is the class to which all beasts, in-
cluding of course the cat, belong, and of which man also (zoologically
considered) is a member. The province MonoconpyLa? contains
two classes: the class Aves (birds), and the class Reptilia. The latter

* This mode of expression is used | union of the cerebral hemispheres by a
because many back-boned animals have | corpus callosum.

no limbs, and we are here considering ft A term referring tu the union of the
only such characters in the cat-as are | skull and spine by one occipital condyle
common to every back-boned animal. only.

+ A term referring to the median

456 THE CAT. | [cHAP. xi, a

class embraces all crocodiles, lizards, serpents, and tortoises, with

extinct forms more or less allied to these. The province BRANCHIATA *

is the third and last. It consists of two classes: the class Batra-—

chia—i.e., the class of frogs, toads, efts, and their allies—and the
Selass Pisces, which includes all Anes

Our present task, then, 1s to see what is implied 1 im saying that
the cat is a “beast” or a “mammal.” To see this we must know
its relations, simply as a mammal, to the other forms of vertebrate
life, z.e., to the groups Pisces, Batrachia, Branchiata, Reptilia,
Aves, and Monocondyla, and to all the non-mammalian vertebrates
taken together.

If, to help us in our comparisons, we examine any ordinary fish,
such as the cod (Gadus), we see in it an animal with a large, néckless
head and a long and powerful tail, with a membranous production
from the back (a dorsal fin), one. beneath the tail (an anal fin), and
two pairs of fins placed laterally, ventrally and far forwards, and
termed respectively the pectoral and ventral fins. ‘The body of the
fish is clothed with scales, and exhibits an undulating mark running
from before backwards (from head to tail) on each side, called the
lateral line. The tail ends in a membranous, vertical expansion, or
caudal fin, which is supported (as aré all the other fins) by many
delicate but firm fibres within its substance, called jin-rays. The
nostrils do not open into the mouth posteriorly, but each has two
openings on the exterior of the snout. The orbits do not com-
municate with the nares by any lachrymal tube, nor the ears with
the mouth by any Kustachian tube, but there is a large aperture on
each side behind the head, which leads into a chamber wherein are’
a number of membranous plates, or “gills,” attached to the outside
of a series of arches between which are clefts leading into the
alimentary canal just behind the mouth. These gills are breathing

organs, adapted to aid the needful respiratory gaseous exchange
between the blood within them and the atmospheric air which is
dissolved in the water the animal mhabits. There is a perfectly-
closed air-bladder just beneath the vertebral column, but there are
no lungs and no pulmonary arteries. The aorta divides—as in the
embryo cat—ainto a series of arches which ascend the sides of the
pharynx to reach the dorsal aorta, but each artery is, on its way
upwards, broken up into a network of minute capillar y vessels
within the membranes or leaflets of the gills. Thus the blood leaves
the heart in an impure or venous condition, and, having gone thence
to the aquatic respiratory organs—or gills—it does not return directly
to the heart, but passes up in an arterial condition to the dorsal
aorta. Consequently neither a second auricle nor a second ventricle
is required, and neither exists—the heart consisting, as in the
embryo cat, only of a single auricle and ventricle, the venous blood
passing into the former from a “sinus venosus,”’ and being given

* A term referring to the all but uni- | life if not permanently) in all Batrachians
versal presence of gills (at one time of ! and Fishes.

ewap.xm.]) THE CAT’S PLACE IN NATURE. 457

out by the latter into a “bulbus aorte,” whence the lateral aortic
-arches take their origin. Other transitory conditions of the cat’s
embryonic circulation are found persistent in the cod. Thus the
blood is brought back to the heart by large anterior and posterior
cardinal veins which unite on each side in a “ ductus Cuvier,” which
__ opens into the sinus venosus, and no large iliac arteries, or great
; anterior and posterior venee cave are ever developed. Similarly in

the development of the cod, no umbilical veins or arteries ever

appear, for no allantois (and indeed no amnion) is ever formed ; but
the omphalo-meseraic arteries and veins are the only ones employed
in nourishing the embryo. But the nature of the arches which

support the gills needs explanation.

We have seen how, in the cat, the hard parts of the successive
visceral arches of the embryo respectively become the mandible, the
chain of bones forming the anterior cornu of the os hyoides, and also
its posterior cornu or thyro-hyal.* In the cod, similar arches also
become (successively from before backwards), the mandible and the
chain of bones answering to those of the cat’s anterior hyoidean
cornu. But the visceral arches more posteriorly placed, become
these successive arches which (because they support the gills) are

ealled “branchial ”—one branchial arch being formed from each
such more posteriorly-situated visceral arch. All the gill-arches of
each side answer, in fact, to one of the cat’s thyro-hyals, as we
shall see more distinctly in considering Batrachians.

The two pairs of lateral fins before noticed—the pectoral and
ventral fins—answer to the pectoral and pelvic pairs of limbs of the
cat, but their internal skeleton is not divisible into arm, carpus, and
digits ; or leg, tarsus and digits—that is to say, they have not what
we may call the “ ‘typical differentiation.” + The muscles of the
limbs are few in number and simple in arrangement. The ventral
fins are attached to two bones which answer to the cat's pelvis, but
they are so far from forming a “limbv-girdle” that they do not even
tend to reach the axial skeleton. The “shoulder-girdle,”’ however,
is well developed, and, though there is no sternum, it is complete in
the middle line below, while above it is continued on by bones till it
abuts against the skull.

The lower jaw consists of more than one bone on each side, and is
attached to the skull by the intervention of a complex, bony, and
cartilaginous structure, which may be shortly spoken of as a
suspensorium. Into its composition parts enter which correspond
to the auditory ossicles of the cat. On the base of the skull is a
large, long bone called the parasphenoid (which is not represented in
the cat's skull, save by membrane on the basis crani1), but there 1s no
basi-sphenoid and the periotic bones (?.¢., the pro, epi and opisthotics)
remain as distinct, permanently, as they temporarily do in the
aoe cat. They do not, therefore, coalesce to form a “ petrous

one.”

Ae a el, Bae
¢ nih
er
reas |
. poe

eae sched om > 25-97

* See ante, p. 339 vertebrates which have limbs and which
fT So called because it exists in all ! are not fishes.

a? He rege al Beko Pe een Ads
‘ te.

458 CHE CAT. [CHAP, XIIL

The brain has very small cerebral hemispheres unconnected by
any corpus callosum, and the optic lobes are relatively very large,
thus agreeing with the brain of the embryonic cat. There are
no hypoglossal nerves, and the olfactory nerves do not traverse
any cribriform plate, nor has the ear any tympanic membrane, spiral
cochlea or fenestra ovalis. There are no Fallopian tubes, and the
ovaries in the female are (as well as the testes in the male) directly
continuous with ducts which lead to the exterior. There is no cloaca
and there is no penis, but the anal, urinary, and sexual apertures all
open on the surtace of the body, the anal opening being in front and
the urmary opening the most posteriorly situated. No temporary
urinary organs are developed to be replaced by true kidneys, but the
primitive urinary organs persist. The blood is cold, and its red cor-
puscles are nucleated. There being no lungs and no trachea, there —
is of course no larynx. Similarly there is no diaphragm, such as
we have met with in the cat. ;

Fishes, generally, agree with the cod in the above-mentioned
characters, but some exceptions should be noted. The lowly orga-
nization of the lancelet has been already referred to. Amongst the
highest fishes, such as the sharks and rays, the skeleton is cartila-
ginous; there is a cloaca, and there are Fallopian tubes. In the
very exceptional mud-fish (Lepidosiren) the heart has two auricles,
the nostrils open posteriorly within the front of the mouth, and
there are lungs and a pulmonic circulation.

§ 11. The cat then, inasmuch as it is a MAMMAL, may be said to
differ from the class of FisHxs in the following points :—

(1) It has a skeleten, the appendicular parts of which have the
typical differentiation, |

(2) The hyoid is a structure with simple thyro-hyals, which are

not in the form of successive arches.

(3) The skull has a large basi-sphenoid, without any para-
sphenoid.

(4) It has a petrous bone.

(5) Its mandible consists of two bones only—one on each side.

(6) The mandible directly articulates with the skull, and there
is NO Suspensorium.

(7) The auditory ossicles are minute, and take no share in sus-
pending the mandibles to the skull. -

(8) There are cervical vertebree.

(9) Its ribs join a sternum.

(10) Having pelvic limbs,* its pelvis is united dorsally to a

sacrum.

(11) The body is furnished with hair.

(12) The muscles of its limbs are complex. t

* This expression is adopted because + Even in mammals such as the por-
in some mammals which have no pelvic | poise, in which the limbs are mere pad-
limbs there is no junction of pelvis and | dles, the muscles are very different from

sacrum. | those of the cod.

q i
so

CHAP. xu] THE CAT’S PLACE IN NATURE. 459

(18) Its cerebral hemispheres are large, and united by a corpus

callosum.

(14) There are small corpora quadrigemina imstead of large optic

lobes.

(15) There are hypoglossal nerves which perforate the exoc-

cipitals. |

(16) The olfactory nerves being present,* traverse a cribriform

late.

(17) The ear has a tympanic membrane and an Eustachian tube.

(18) The posterior nares open far back within the mouth. f

(19) There are no gills at any time of life.

(20) Respiration after birth, is pulmonary only.

(21) The heart consists of two auricles and two ventricles.

(22) All the blood of the body traverses the lungs.

(23) There is but one aortic arch.

(24) There is a large anterior vena. cava and a large posterior

vena cava.

(25) There is a larynx.

(26) The hinder end of the alimentary canal does not terminate

auteriorly to the urinary outlet.

(27) There is a complete diaphragm aiding respiration.

(28) There are no fin rays.

(29) The red blood-corpuscles are not nucleated, and the blood is

warm.

(30) There are cervical vertebre.

(31) In development an amnion is formed.

(32) Cardinal veins, at first important, afterwards become subor-

dinate to the ven cavee.

(33) Kidneys replace transitory Wolffian bodies.

(34) There is an allantoic placenta.¢

(35) There is a fenestra ovalis.

§ 12. We come now to the class Barracuia, which contains, be-
sides the frogs, toads, and commoner efts, certain noteworthy eft-like
creatures, such as the gigantic salamander of Japan and China, the
Menopoma, Amphiuma, Menobranchus and Siren of the United States,
the Avzolot/ of Mexico, and the Proteus of the dark subterranean
caverns of Carniola and Istria. Besides these animals, the class also
contains certain limbless creatures which look like something between
snakes and earthworms. They have long, slender bodies, marked by
many transverse wrinkles, and are called Ophiomorpha. Creatures
which lived during the deposition of the carboniferous strata, and which
are known as Labyrinthodonta, are also included amongst Batrachians.
The common frog (Rana temporaria) may be taken as a type of this
class. This animal has two pairs of well but unequally developed

* In a few mammals they are absent. + In certain sharks a placenta is

+ That they open into the mouth at | formed, but by the intervention of the
all, would serve to distinguish the cat’s | umbilical vesicle. It is not therefore an
class from all fishes save such as the | allantoic placenta.
Lepidosiren. th) ay

1 ed Yo Ae
| Sieg

r
7?

"<5

460 THE CAT. (CHAP, XIII, |

limbs, each of which ends in four or five digits, and has the typical
difterentiation. Though without a neck externally visible, it may
be reckoned as having one cervical vertebra. Its body is not only
devoid of hair, but also of scales, and is perfectly naked and more
or less moist—its surface helping importantly in the respiratory
process. The adult has no fins, but in the young, or tadpole con-
dition, fins are present, but are always devoid of fin rays. Neither
is there any lateral line. The nostrils open within the mouth, and
the tympanic cavity communicates with the throat by a wide and
short Eustachian canal. In the adult, there are no gills, but
there are lungs with pulmonary arteries and veins and two auricles.
Nevertheless not all the blood goes through the lungs at each
circuit ; and there are several aortic arches. In the young there is
but one auricle, and there are gills and an arrangement of vessels
substantially as in the cod. Similarly in the young there are gill
arches behind the hyoidean cornua, which latter answer to the
anterior hyoidean cornua of the cat. In the course of deve-
lopment, however, these hinder gill arches shrivel into what

evidently represents the thyro-hyals of the cat. The blood has its -

red corpuscles nucleated, and tite cardinal veins of the young become
subordinate to the subsequently developed venze cavee. The pelvic
limbs are attached to a pelvic girdle which joins a sacrum, but no
ribs articulate with the sternum. The muscles of the limbs are
numerous and complex. The skull has a large parasphenoid, but
no basi-sphenoid. The periotic bones coalesce. The cranium joins
the spme by two occipital condyles, but the basi-occipital is rudi-
mentary. The mandible consists of more than two bones, and it is
suspended to the skull by a complex suspensorium, including parts
representing the auditory ossicles. The same may be said of its
brain as has been said of the cod’s. The olfactory nerves traverse
no cribriform plate, but there is a well-developed tympanum, though
there is no spiral cochlea. The alimentary canal and renal and

sexual ducts open into a common cloaca, and the primitive urinary —

organs persist. Respiration, though serial, is not effected by a
diaphragm, but the lungs open into the alimentary canal by a short
tube, at the anterior end of which is a simple larynx.

§ 13. Bearing in mind the conditions presented by the other forms
of the class Batrachia, we may say that the cat, as a MAMMAL, differs
from all BarracutaAns, as follows :-—

(1) Its skull has a large parasphenoid, but no presphenoid.

(2) Its mandible consists of two bones only, one on each side.

(3) Its mandible directly articulates with the skull, and there is
no suspensorium.

(4) Its auditory ossicles are minute, and take no share in sus-
pending the mandible of the skull.

(5) Its ribs join a sternum.

(6) Its body is furnished with hair.

(7) Its cerebral hemispheres are large and united by a corpus
callosum.

cuar.xu.] THE CAT’S PLACE IN NATURE. 461

(8) It has small corpora quadrigemina instead of large optic
lobes.

(9) Olfactory nerves being present, they traverse a cribriform
| late.

(10) The posterior nares open far back within the mouth.

(11) There are no gills at any time of life.*

(12) Respiration is pulmonary only from birth.

(13) Its heart is furnished with two ventricles.

(14) All the blood of its body traverses the lungs.

(15) It has but one aortic arch.

(16) There is a complete diaphragm aiding respiration.

(17) Its red blood-corpuscles are not nucleated, and its blood is

warm.

(18) There are several cervical vertebree.

(19) In development an amnion is formed.

(20) Kidneys replace transitory Wolfhan bodies.

All these characters serve to distinguish the Cat’s class from that of
Fishes, as well as from Batrachians, and therefore they will also
serve to distinguish the cat, in so far as it 1s a mammal, from the
whole province BRANCHIATA.

§ 14. From amongst the creaturesincluded in the class Reprizta (the
lower of the two classes which make up the province Monocondyla)
we may select, as a type, the common lizard (Lacerta agilis). In it
we find a little long-tailed quadruped, the body of which is clothed
with horny epidermal scales. The thoracic and abdominal portions
of its body-cavity are not divided by a diaphragm, for it—unlike
that of the cat—forms no complete partition. The ribs are connected
with a sternum. The skull has but one occipital condyle. The
mandible consists of more than one bone on each side, but is con-
nected with the skull by one bone only—the os quadratum. This
bone answers to the proximal part of the cat’s malleus, while the

part of the mandible which articulates with it answers (as it does
- also in the Branchiata) to the distal part of the malleus. There is
no cribriform plate. The periotic bones unite with <«djacent skull
bones before uniting with each other, so that they do not form a
“etrous bone.”’ The limbs have the typical differentiation, and
the pelvis joms the sacrum. But the jomt of the hind foot with
the leg, is not situated between the tarsus, as a whole, and the tibia,
as 1s the case in the cat. It is situated in the middle of the tarsus,
the proximal part of which is firmly bound to the tibia by fibrous
tissue, while the distal part of it is similarly bound to the meta-
tarsus. The phalanges of the digits are more numerous than in the
eat, and differ in number in different digits. There is no corpus cal-
losum, but there are a pair of large optic lobes. The lungs are freely
suspended in the thoracic cavity, but the bronchi do not branch
within them dichotomously. The two ventricles of the heart are

* This and the next character do not | pipa toad, and of one or two other kinds,
seem never to develop gills.

apply in every case, as the young of the

cemeteries e t CCT CC T

462 THE CAT. "CHAP. XIII.

but incompletely divided, and the posterior nares open far forwards
within the mouth. There are Fallopian tubes, and in development
both an amnion and allantois are formed, but no placenta—the
allantois being itself directly respiratory. There are never any
ills.
: Some lizards and almost all serpents are limbless, but the ecroco-
diles and alligators differ from the other reptiles in having two
distinct ventricles, with nares prolonged to quite the posterior end of
the palate. Nevertheless, even in crocodiles, there is more than one
aortic arch, and these arches so communicate that a mixture of
venous and arterial blood takes place in them.
§ 15. We may then say that the cat, as a MAMMAL, differs from
the whole class Reprrita in the fullowing characters :—
(1) There is a petrous bone, and a mandible formed of two bones
only, each directly suspended from the squamosal.
(2) The auditory ossicles are minute, and take no part im sus-
pending the mandible.
(3) There are two occipital condyles.
(4) The skin is furnished with hair.
(5) There is a corpus callosum, and the corpora quadrigemina
are small.
(6) There is a cribriform plate.
(7) All the blood passes through the lungs at each circuit.
(8) There is no communication between the arterial and venous
vessels outside the heart, save the capillaries.
(9) There is but one aortic arch.
(10) There is a complete diaphragmatic partition.
(11) There is no intertarsal joint, the tarsus moving as one whole
upon the tibia.
(12) The red blood corpuscles are not nucleated, and the blood is
warm. ,
With the exception of the crocodiles and alligators, we may say .
that the cat also differs from all reptiles :—
(13) In that it has two distinct ventricles, and
(14) In that the posterior nares open far back within the mouth.
§ 16. Turning now to the class Aves, whatever bird we may
select as our type, will exhibit to us structural peculiarities well
deserving attention. The rook (Corvus) will be a good example to
contrast with the cat and the cat’s class. Its different external
aspect (as compared with the cat) depends upon the following con-
ditions:—The rook’s posture, on the ground, is nearly upright, its
body being supported on the legs only, the pectoral limbs being
modified into wings. The facial part of the head is produced into a
long, conical, pointed beak. The region of the chest is rounded and
prominent. The whole frame (except the beak and legs) is clothed
with feathers, and it is to them that the appearance of a long tail
is due, for only a stumpy tail-structure is visible when they are
removed. The feathers are very different in different parts of the
body, much the longest being attached to the tail and arm, and

t

CHAP. XIII. | THE CATS PLACE IN’ NATURE. 463 ©

especially to the distal segment of the arm, which corresponds to

the fore-paw of the cat. The lower parts of the legs are clothed
with horny scales.

In internal structure, the main characters agree with those of the
cat, but there are a multitude of differences. The more significant
of these are as follows:—The thoracic and abdominal cavities are
not quite separate, the diaphragm forming only an incomplete
partition.

The cervical vertebree are thirteen and the dorsal eight, and
behind these no less than ten, at the least, are fused with the pelvis
into a great solid sacral mass which includes even the last two
dorsals. The caudal vertebree are few and end in a bone, shaped
somewhat like a ploughshare, called the zygostyle.

The ribs which are connected with the sternum are connected
with it, not by the intervention of costal cartilages, but by long
narrow bones (sternal ribs) instead.

The sternum consists mainly of a great flattened quadrangular
sheet of bone, from the middle of the ventral surface of which a
long and strong keel projects, supporting a mass of flesh which hes
on each side of it, and which is related to the power of flight.

The skull has but one occipital condyle, and the front apertures
of the nares are placed some distance back from the front end of the
skull—one on each side of the bony beak. No zygoma passes back
from the hinder margin of the orbit, but a needle-like bone bounds
the orbit externally below, passing backwards from the beak to
abut against a movable complexly shaped bone—the os quadratum.
Inside the skull there is no cribriform plate, but only a foramen for
the nerves of smell, while the bony palate shows some large open-
ings, two of these being the posterior nares. The periotic bones
unite with other cranial elements before uniting together.

The lower jaw, toothless hike the upper, is made up of several
bones on each side. It does not join the squamosal, but fits, by an
irregularly shaped hollow cup, to the lower part of the os qua-
dratum.

The shoulder-girdle is complete. Instead of each blade-bone
having only a small coracoid process, there is, as in the lizard, a
large and distinct coracoid-bone, which passes down from the slender
blade-bone to abut against the breast-bone, and the arch is further
complete by the clavicles which, instead of being two separate
slender little bones embedded in the flesh alone, here form the
merrythought or furculum, which above abuts against the coracoids
and scapule, and below is firmly fixed to the sternum.

The anterior extremity of the pectoral limb is greatly reduced,
exhibiting only rudiments* of the parts we saw in the cat’s fore-

aw.
‘ The pelvic girdle is at once more complex and less complete than

* There are two carpal bones ; three | two are separate save at their ends), and
metacarpals united in one mass (though | three digits with one or two phalanges,

in one Jarge mass, while ventrally it is widely open. The acetabu-
lum is perforated.

The fibula is but a needle of bone fused below with the tibia, but
the most surprising thing is, the apparent absence of a tarsus alto-
gether.

y Directly below the tibia there is only one long bone, which repre-
sents three metatarsals united in one and supporting three digits, while
at the lower end of its inner side is a small separate metatarsal bone
for the fourth digit. In fact, in the rook, the tarsus has partly
united with the tibia, and partly with the metatarsus, so that the
joint is placed not between the tibia and the tarsus, but im the
middle of the tarsus itself, which has become blended with adjacent
parts—the proximal part of the tarsus anchylosing with the tibia,
while its distal part anchyloses with the tarsus. |

As in the cat, so here, there are only four digits, but in the rook
it is the representative of the outermost or little digit, not of the
hallux, which is absent. Counting from within outwards, the
numbers of the phalanges are two, three, four and five, a different
number for every digit.

The spinal marrow has the lower parts of its canals centralis
expanded, while at the same time in the brain the ventricles are

small and there is no fifth ventricle.

The smaller hemispheres are also not connected by any corpus

. callosum, and instead of corpora quadrigemina there are two lobes
j called optic, placed one on each side in a lateral and depressed

7 position. The two Eustachian tubes open into the alimentary canal

‘ by a single aperture.

: The great artery, the aorta, sends out only one branch, which

4 arches over the right bronchus. The right auriculo-ventricular

+ valve is muscular and not merely membranous as in the cat.

i The lungs are not freely suspended in the thorax, but are fixed
| to the back of its cavity, and the bronchi do not divide dichoto-
| mously within the lungs. Moreover, they communicate with air-
| | sacs, which not only extend within the body but even enter certain
| of the bones, which are thus themselves filled with air. Thus the

Bees
464 THE. CAT. [CHAP, XIII. |
in the cat. As has been said, it unites dorsally with many vertebree

circulating and respiratory structures are such as to give to their

functions an even greater perfection than in the cat. This perfec-

tion is needed for the almost constant activity of the bird, and the

q enormous muscular power. it has to exert in flying. Where the
ff trachea divides into the two bronchi there is a special arrange-
7 ment of parts called the syring, or “lower larynx,” the upper larynx
| (which corresponds with the larynx of the cat) bemg much smaller.
The ureters do not open into the bladder, but into a chamber or

reservoir (the cloaca), into which the bladder also opens, while the
cloaca itself opens on the surface of the body. It is also into this

cloaca that the posterior end of the alimentary tube opens, and not

on the surface of the body. Into it also open the ducts from the

| testes in the male, and the (here single) Fallopian tube of the

CHAP, XIII. ] THE CAT’S PLACE IN NATURE. 465 -

female. Both testes and ovarics are enclosed in the abdominal
cavity, and in the rook there is no urethra or prostate or Cowper’s
glands, and no penis or clitoris, vagina or uterus, or any mammary
glands. No placenta of any kind is formed, but the allantois is
directly respiratory. It lines the egg shell, which is porous enough to
admit of the respiratory gaseous interchange taking place through it.

In almost all the differences from the cat here enumerated, all
birds agree with the rook, whatever may be their habit of life or the
general external influences to which they are exposed.

Thus the ostrich and apteryx cannot fly, and yet their pectoral
limb is formed on the type* of that of the crow, as also is the sub-
ees paddle of the penguin, a bird as incapable of flight as the
ostrich.

ne 17. The catis then, as a MAMMAL, distinguished from BIRDS in
that :
(1) Itsskull hasa “petrous bone,” and a mandible formed of two
pieces only and suspended directly from the squamosal.
(2) Its auditory ossicles are minute and take no part in
suspending the mandible. :
(3) There are two occipital condyles.
(4) Its skin is furnished with hair.
(5) Its cerebrum is large, with a corpus callosum, and its corpora
quadrigemina are small.
(6) Olfactory nerves being present, there is a cribriform plate.
(7) Its ear has a complex, spiral cochlea.
(8) Its solitary aortic arch, arches over the left brunchus.
(9) No air-cells communicate with the lungs.

(10) It has no syrinx, but a large and complex larynx.

(11) Its lungs are freely suspended in the thoracic cavity.

(12) It has a complete diaphragm.

(13) Its posterior nares open far back within the mouth.

(14) The ulna is larger than the radius.

(15) The skeleton of the extremities is arranged on a different

type.

(16) The pelvis extends less forwards.

(17) The ankle-joint is not an intertarsal one.

(18) The proximal and distal parts of the tarsus do not anchylose

with the tibia and metatarsus respectively.

(19) The caudal vertebrae do not end in a “‘ploughshare f bone.”

‘(20) The red-blood corpuscles are not nucleated.

(21) The right auriculo-ventricular valve is membranous only

and not muscular.

(22) It has no feathers.

(23) The corpora quadrigemina are not laterally depressed.

(24) The Eustachian tubes open separately within the alimentary

canal.
* In these birds the breast- bone though + Neither do they in the extinct meso-
wide is keelless. | zoic bird—the Archeopteryx. , |

HH

466 ; THE CAT. : [CHAP, XIII,

(25) No digit of the pelvic limb has more than three phalanges.*
The first eight of the foregoing characters, together with the 12th,
17th, and 20th, serve to distinguish the cat, as a MAMMAL, from the
whole of the province Monoconpyta. It is also distinguished from
all BACK-BONED ANIMALS WHICH ARE NOT MAMMALS, in the fullow-
ing points :
(1) The mandible consists only of one bone on each side, and
directly articulates with the squamosal.
(2) The malleus and incus are only small auditory ossicles. |
(3) The periotic bones anchylose together to form a petrous bone
before anchylosing with parts of the occipital.
(4) There are two occipital condyles co-existing with a distinet
basisphenoid.
(5) There 1s a cribriform plate unless olfactory nerves are absent.
(6) There is but one aortic arch, which arches over the left
bronchus. ) cme
(7) Two auricles and two ventricles co-exist with a membranous
right auriculo-ventricular valve, and a single aortic arch.
(8) There is more or less hair.
(9) There is a corpus callosum and fifth ventricle.

(10) The red-blood corpuscles are not nucleated. .

(11) There is a complete diaphragm, which acts as the main

respiratory organ. :

(12) The male has a penis traversed by the urethra.

(18) The female is provided with mammary glands. 2

Such then is the cat’s place in nature, so far considered. The
cat is a beast, or mammalian back-honed animal, because it has the -
anatomical characters above enumerated, and the varying degrees
of its divergence from the other provinces and classes which go to
make up the sub-kingdom Vertebrata, are to be estimated according
to the variations of structural conditions which have been indicated in
the lists of characters above given. It remains to see the rank and
position which the cat may claim amongst its fellow mammals.

§ 18. Besides the creature to the study of which this book is
devoted, all the animals most familiar to us and most generally.
valuable to us—as our dogs and our domestic cattle—are members
of the class Mammalia. The name “beasts”? is in more or less
general use to denote the various brute animals which belong to the
class; but since man himself—the most individually numerous of
all the large animals—is, structurally considered, also 3 member of
it, the name ‘“ Mammals” will be henceforth always exclusively
here employed to denote the creatures which compose it. :

Hitherto we have been occupied but with sub-kingdoms, pro-
vinees, and classes; the characters of subordinate groups of the
Invertebrate sub-kingdoms having no bearing upon the question as
to the cat’s place im nature. Now, however, such subordinate

* This can only be affirmed of the | some aquatic mammals (Cetacea) has
pelvic limb, because the pectoral limb of |

digits with more than three phalanges.

CHAP.. XIII. ] THE CAT’S PLACE IN NATURE. 467

groups, as they exist in the class Mammalia, must be more
or less considered; for the cat belongs to a mammalian genus
which comprises the majority of the forms reviewed in the twelfth
chapter of this work. The whole of these forms—all the lons,
tigers, leopards, jaguars, pumas, ocelots, lynxes, cheetahs, and other
living and extinct cats—form together a group which has the
zoological rank of a “ family,” and it is a family of an “‘ order’”’ divisible
into “ sub-orders,”’ while the order itself is one of various others which
go to make one of the three very unequal “sub-classes”’ which
together make up the whole class Mammalia. The class Mammalia
has been now compared with all the other classes of back-boned
animals, and the vertebrate sub-kingdom with all other sub-
kingdoms of animals. It remains to compare the cat’s sub-class with
the other mammalian sub-classes; the cat’s order with the other
orders of its sub-class; the cat’s sub-order with the other sub-orders

into which its order is divisible, and the cat’s family with the other

families which, together with that family itself, make up the sub-
order within which the cat is included. This done, we have but to
consider the results arrived at in the twelfth chapter as to genera
into which the cat’s family is divisible, m order to exhaust our

present inquiry by attaining a final and satisfactory answer to the
question “‘ What is the cat’s place in nature?” and to understand

the cat’s taxonomy.

Closely allied to the domestic cattle—our sheep and oxen—are
all bisons, buffaloes, goats, antelopes, deer, giraffes, chevrotains,*
llamas, and camels. Less closely allied, but still allied, are all
peccaries and swine, and the hippopotamus. With these, also, may
be associated the rhinoceros and tapirs, and lastly all asses, quaggas,
zebras, and horses. All these creatures together constitute one
order of mammals, the order Uneuxara, into which the little hyrax,
the ‘‘coney”’ of the English Bible, may or may not be admitted,
according to the view of classification adopted.

Somewhat, allied to ungulates, but distinct from them, are the
elephants, which form the order ProgoscipEa, an order which once—
with its various species of elephant, large and small, its Mastodon
and Dinotheria—was rich in species and individuals, and was widely
distributed over the world’s surface.

Somewhat related to them again is the numerically very small

order SiRENIA: an order now containing only the Manatee and

Dugong, although another genus, Khytina, still existed at no distant
period.t

Other marine creatures, really very different in nature from the
Sirenia, were long classed with them. These are the many kinds of
whalebone-whales, porpoises, sperm-whales, and dolphins, which
togetber make up the order Crracea. Yet other marine creatures, of

less decidedly and exclusively aquatic habits, are the seals and sea-

-Im error musk-deer.

+ Very small animals, commonly called | ft It was exterminated in the year
1768

H H 2

Ne ee a er rr IRS tn np ei rn nee cn ee eon

468 THE CAT : [CHAP, XIIL

lions (or sea-bears), which constitute the order Pinnipepia. All kinds
of apes, together with man, and certain animals called ‘‘ Lemuroids,”
form another mammalian order—one to which Linneeus gave the
name Primates. Lemurs are animals with fox-like snouts, but with
paws like those of apes, which inhabit the geologically remarkable
island of Madagascar. ‘ Lemuroids” are lemurs and creatures like
lemurs, and such are found either in Madagascar, or more or less in
the vicinity of the Indian Ocean, though a few reach western Africa.

The only beasts which truly fly are bats, which form an order by
themselves. It is well named CHErRoPTERA, since their wings are
enormously spread-out hands with webbed fingers. When
Australia was discovered, very many new and strange mammals
were there found ; differing amongst themselves greatly in external
appearance, mode of life, food, and size. Large kangaroos browsed
over the plains, taking the place elsewhere occupied by browsing
ungulates. Many phalangers climbed the forest trees, with feet the
great toes of which were prehensile, acting like ‘‘ hind-thumbs,” as
in the feet of apes. Certain small quadrupeds with molar teeth
bristling with sharp points—the bandicoots—fed on insects,
while the wombat, a squat-shaped sluggish animal, was specially
qualified for nibbling and grinding vegetable food by two large
meisors above and below, followed (after a wide diastema) by flat-
surfaced molars. Some Australian mammals were enabled to take
prolonged jumps by means of lateral skin extensions which procured
for them the name of “ flying opossums” (Petaurus, &c.). Other
mammals were more or less fierce beasts of prey, with teeth
remotely like those of the cat, and with blood-thirsty habits. Such
were the native-cats or Dasyures, and the Thylacine or Tasmanian
wolf. All these various mammals, however different in form,
together constitute but a single order, MArsuptafa, an order into
which the insect-eating and flesh-eating opossums of America must
also be admitted. Two other Australian forms justly excited wonder
when discovered. One of these was the platypus or Ornitho-
rhynchus (with a squat, hairy, body, short limbs, and a duck’s bill) ;
the other was the Hchidna—an animal covered with spmes, and with
a slender snout devoid of teeth, a long tongue, and strong nails
suited to its ant-eating habits. These two forms by themselves
constitute the order MonorREMATA.

In South America other edentulous, strong-clawed ant-eaters are
found, which, with the South African Aard-vark (Orycteropus), the
scaly pangolins (Manis), the sloths and armadillos, with the huge
extinct Megatherium and Mylodon, together make up an order called
Eprntata. Insect-eating beasts (mostly small, and having amongst
them the absolutely smallest mammal), such as the hedgehog, the
Asiatic Gymnura, the moles, shrews, elephant-shrews, water-shrews,
tupaias, tanree (Centetcs), Solenodon, Potomagale, the golden mole,
&e., are all united in one ordinal group, which bears the name of
Insectrvora. Another very large ordinal group has teeth like those
of the wombat. This is the order Ropentia, which contains all

>

¥
A.
4
ke
P
y
7
Sa:

CHAP. XIII] THE CAT’S PLACE IN NATURE. 469

rats, mice, squirrels, guinea-pigs, porcupines, beavers, jerboas, rat-
moles, and rabbits and hares. Some rodents are, like the flying
opossums, fitted to flit through the air in long jumps, by means of
the wide extensibility of the skin of their flanks, which, when
stretched out, acts as a parachute—such are the so-called “ flying-
squirrels ” and the genus Anomalurus. _

Lastly we have the order to which all the kinds of cats belong,
tovether with all pole-cats, civet-cats, hyenas, bears, weasels, dogs,
wolves, and foxes—the order of flesh-eating mammals par excellence,
or CARNIVORA.

These various orders of the class Mammalia are grouped together
into three sub-classes as follows :—

The order Monotremata is an order so exceedingly different from
all the others that there can be no doubt (in spite of the few species
it contains) of its forming a sub-class by itself. It forms the sub-
class ORNITHODELPHIA.

The order Marsupiala differs much less from the great bulk of
mammals than does the order Monotremata, nevertheless it also is
reckoned as forming a second sub class by itself. It forms a sub-
class much more numerous than the sub-class Oriithodelphia, yet it
contains but very few species when compared with the number of
species contained in the third sub-class. The second or Marsupial
sub-class bears the name Dipetpuis. All the rest of the mammalia—
that is to say the whole of the orders Ungulata, Proboscidea, Sirenia,
Cetacea, Pinnipedia, Primates, Cheiroptera, Edentata, Insectivora,
Rodentia, and Carnivora, together make up the third and last
mammalian sub-class, that containing the placental mammals—the
sub-class MonoDELPHIA.

§ 19. Now the cat, as a monodelphous mammal, of course shares
the characters which distinguish that sup-ciass from both the others.
We have then first to see how the cat thus differs from the
Ornithodelphia.

The Ornithorhynchus and Echidna agree together in having an
exceedingly rudimentary corpus callosum, a condition perhaps more
or less compensated for by the very large size of the anterior com-
missure. In the internal ear, the cochlea instead of being spirally
coiled, as we saw it to be in the cat, is but slightly twisted. The
vertebre are not ossified by the intervention of epiphyses, and the
shoulder-girdle is of remarkable complexity. Instead of mere
coracoid processes, such as we saw in the cat, there are large
coracoid bones (as in birds) with epicoracoid bones, and an inter-
clavicle—as in many lizards. The acetabula are also perforated (as
im birds) and the fibula sends up a large olecranon-like process,
rendering its serial homology with the ulna strikingly evident.
The internal tendon of the external oblique muscle of the abdomen
is ossified, resulting in the development of two large bones, called
“ Marsupial,’ which are attached to the front margin of the pelvis.
The mouth is either edentulous, or if, as in the Ornithorhynchus,
there are teeth, then these are not calcareous but of a horny

470 THE CAT. [cHAP. XIIL

texture. Posteriorly the alimentary canal. opens into a cloaca (as
in the Monocondyla) which also receives the terminations of the
ureters and generative ducts. Thus the ureters do not open into
the bladder, although a urinary bladder is fully formed. The penis
is perforated by a urethra, but this does not transmit the renal
secretion, as it is proximally discontinuous with the cystic urethra,
and serves but for the testicular product. There are two uteri,
which open side by side into the cloaca, so that there is no vagina
any more than in birds—from which circumstance the name of the
sub-class is derived. The mammary glands pour out the milk from
numerous apertures on the surface of the skin, but these are not
aggregated mto a distinct prominence or nipple. No allantoic
placenta is developed. Thus the cat, as a MONODELPHOUS MAMMAL,
differs from the lowest mammalian sub-class the ORNITHODELPHIA,
by the following characters :—
(1) There is (in the female) a vagina.
(2) There is no cloaca.
(3) The cystic and spongy portions of the urethra are continuous,
and it transmits the urine. 1
(4) The ureters open into the bladder.
(5) The mammary glands have teats.
(6) The vertebra ossify by terminal epiphyses.
(7) Development is effected by the help of an allantoic plod ,
(8) The cerebrum has a large corpus callosum and a small
anterior commissure.
_ (9) The ear has a complex, spirally coiled cochlea.
(10) The coracoids are but small processes.
(11) There are no epicoracoids or interclavicle.
(12) The acetabula are imperforate.
(13) There are no marsupial bones. |
(14) The fibula has no olecranon-like process.
(15) There being teeth * they are calcareous.
' The animals of the order Marsupialia are all much more like the
eat in structure than are the Monotremes. Nevertheless they pre-
sent such important divergences from the structure of monodelphous
mammals, that the whale or bat may both be considered (they being
both monodelphous mammals) to be much more fundamentally like
the cat than is that opossum which has (on account of its superficial
resemblance to our subject) been called the “ native-cat.”
In all the marsupials the vagina is double—whence the name of
their sub-class, Dide/phia. Their process of development takes place
in such wise that the young are brought forth in an extremely
imperfect condition. They are, therefore, in the great majority of
marsupials, sheltered for a time within a “ pouch,” (consisting of a
fold of the skin of the belly) within which are the nipples. Their
young are not developed by means of an allantoic placenta, and when
born, are so feeble and imperfect that they are unable to suck. Or

* Some Monodelphous mammals, as we have seen, have no teeth at all.

4

cHaP. xu.J] THE CAT’S PLACE IN NATURE. 471 -

this account the milk is injected by the mother into the young
while it hangs attached vy its mouth to the nipple. The injecting
action is effected by the cremaster muscle, which embraces the
mammary glands of the females and the testes of the males. The
testes hang in a scrotum ; but this receptacle is placed in front of
the penis instead of, as in the cat, behind it. All marsupials have
marsupial bones except the Thylacine, which has them represented
by large marsupial cartilages. The internal carotid artery enters
the cranium through a foramen in the sphenoid bene. The mandible
has its “angle” inflected. The palate has commonly certain
apertures due to defect of ossification. The corpus callosum is very
small, and the anterior commissure is large. In such marsupial
forms as are carnivorous, the molar teeth are not differentiated into
premolars, sectorials, and tubercular teeth—as im the cat and other
placental carnivora—and there are never six incisors above and six
below. Thus the cat, as a MONODELPHOUS MAMMAL, differs from
the DrivDe.puta in that:
(1) The vagina is single.
(2) The young are brought forth in a well-developed condition.
_ (3) There is no ‘‘ pouch” and the young can suck as soon as born.
(4) There are uever marsupial bones or large * marsupial
cartilages.
(5) The mamme are not embraced by the cremaster.
(6) The scrotum being present + is behind the penis.
(7) The internal carotid does not periorate the sphenoid.
(8) The corpus callosum is large and the anterior commissure
small.
(9) Theeangle of the mandible is not inflected.t
(10) There are six incisors in both the upper and lower jaw.
(11) Reproduction takes place by the aid of an allantoic placenta.
§ 20. Such being the characters which respectively distinguish
fie: eat as a monodelphous mammal from both the mammalian
sub-classes which are not monodelphous, we have next to compare
its ORDER with the oTHER ORDERS of its own sub-class Monodelphia.
Its order, Carnivora, containing the creatures we have already
seen it to contain, is easily distinguishable from the two orders
Strenia and Cetacea, because in both the latter the pelvic limbs are
pewely wanting, or ouly represented by rudiments not oe
visible
The Carnivora are distinguished from all faials of the order
Edentata by possessing median upper incisors, with unequivocal canines
and with molars provided with cutting edges or tubercular prominences
or both. Irom the anteaters they differ in that they are furnished with
teeth ; from the pangolins, in that they are not clothed with horny
overlapping scales ; from the armadillos, in that their skin does not
develop calcareous plates ; ; from the Orycteropus, in that each tooth

_ * In the dog there are very small mar- | a scrotum.
supial cartilages, t It is so however in the monodelphous
t Notall monodelphousmammalshave | mammal—the Tanrec (Cenéetes).

My Py Beer) i Ay
; : tas Peat vl
et sate ¢

472 THE CAT. (CHAP. XIIT.

has not a number of small, parallel pulp cavities; and from the
sloths, in that their digits are not so closely bound together by skin
up to the roots of such enormous curved claws as to reduce the paws
to mere hooks by which the body may be suspended. |

From the Cheiroptera all members of the cat’s order differ in not
having the fingers enormously produced and webbed so as to form
a pair of true wings, enabling their possessor really to fly and not
merely to flit like a so-called flying-squirrel or flying opossum.

The Carnivora differ from the Proboscidea in not possessing a
long trunk or proboscis, and in not having large pendent ears, huge
incisor teeth, and an enormous cecum. Also in having less con-
voluted cerebral hemispheres, two canines above and below, and
digits which are furnished with claws, 7.e. are unguiculate. |

The Primates are all distinguishable from the Carnivora in that
they are monodelphous mammals with either the pollex or hallux or
both, so formed as to be opposable to the other digits and suitable
for grasping. ‘They have also a more or less developed third or
‘posterior’ cornu to each lateral ventricle. None of them are
powerful enough to be able to successfully contend with the largest
of the cats or bears, and but for his intelligence, man himself would
be quite unequal either to fly from or destroy such creatures. Even.
as it is, many human lives are annually destroyed by the largest
carnivora. In the Primates, the placenta is never in the form of a
zone round the ovum.

The Carnivora differ from the Ungulata in that they have often
five (always at least four) digits to each paw. Their digits are also
unguiculate and never sheathed in horny hoofs. Their molar teeth
also are either cutting or simply tuberculate, while the foetus is
developed by means of a deciduate placenta almost always i the
form of a zone round the ovum. The Carnivora also are always
digitigrade or plantigrade, never “ unguligrade,” 7.c., they never
walk upon enormous nails (or “hoofs” ) as is the case with almost
all the Ungulates.

The Carnivora differ from the Rodentia in that they have canine
teeth and have not got large incisors growing from permanent pulps.
They also have the glenoid cavity for the mandibular condyle trans-
versely, and not, as in Rodents, more or less antero-posteriorly
extended. Moreover, though the Rodents have a deciduate placenta,
it 1s never zonary.

The Insectivora differ from the Carnivora by their less perfectly
developed brain, not only the cerebellum but even the corpora
quadrigemina being left uncovered by the small hemispheres, which
are smooth or hardly convoluted. They have, besides, a relatively
small corpus callosum and a large anterior commissure. Their molar
teeth also haye generally more numerous and sharply pointed pro-
minences than in the Carnivora, and their molars are not differen-
tiated into premolars and sectorial, followed by a tubercular form

of tooth. Their bony palate is often defectively ossified, which it 1s

CHAP, XIII. THE CATS PLACE IN NATURE. 473

not in the Carnivora. With one exception* they always have com-
pletely developed clavicles, which in the Carnivora are never more
developed than in the cats. Their generative organs may be pro-
vided with a sac attached to each vas deferens close to its opening
into the urethra, i.e, they may have vesicule seminales (which
Carnivora never have), while the testes are never scrotal, and
though the placenta is deciduate it is not zonary.

Lastly, the Carnivora differ from the Pinnedia in that their hind
limbs are always more or less well suited for progression on land,
being always not only capable of having the plantar surfaces applied
to the ground, but also being free and not held together by integu-
ment down to the ankles as they are in such Pimnipedia as can
apply the soles of the hind feet to the ground, which none of the
true seals can do. In these latter the hind legs are permanently
stretched out in a line with the axis of the trunk and tied to the
tail by a fold of integument, so that they act more like a caudal fin
than like legs. Seals are also entirely destitute of an external ear
or concha. In all the Pinnipedia the middle digit is the shortest m
each hind foot. ‘The brain is very large and very much convoluted,
and there may be a very small third or posterior cornu to each
lateral ventricle, while the olfactory lobes and anterior commissure
are rudimentary and the lachrymal canal and bone are absent.

Altogether it may be said that the cat’s onpER-—the Carnivora—
differs from all the orHeR MonopELPHOUS MAMMALS put together,
in the simultaneous possession of the following common characters,
only some of which are possessed by the various other orders :—

(1) The brain is well developed, with cerebral convolutions (two
or three around the Sylvian fissure), and a well-developed
corpus callosum and small anterior commissure. The
cerebral hemispheres do not cover the cerebellum, nor
do they contain triradiate lateral ventricles.

(2) The eyes are well developed, with a choanoid muscle, and
may have a brilliant tapetum, with an iris capable of con-
tracting its aperture to a vertical linear slit.

(3) The ears are provided with a more or less prominent concha.

(4) The hyoid has, on each side, a short thyro-hyal and a large,
segmented, anterior cornu.

(5) The carpus has a scapho-lunar bone.

(6) No extremity has less than four digits, provided with sharp,
conical claws, and very often there are five digits so provided.

(7) Progression is digitigrade or plantigrade.

(8) No digit is opposable to the others.

(9) There are always well developed. canines.

(10) The incisors are small, and there are always six above and —
six below in each jaw except in the marine otter (Enhy-
dris), and in the fossil Husmilus, which have each but
four inferior incisors.

* The African aquatic Insectivore, named Potomogale.
Ve

74 . ; THE CAT. {CHAP, XIII.

(11) The molars are cutting or tuberculate.

(12) There is a milk dentition.

(13) The stomach is simple.

(14) The caecum is never very large.

(15) There is never more than an imperfect clavicle.

(16) The atlas has two large transverse processes.

(17) The glenoid cavity and condyle are elongated transversely.
(18) The zygoma arches very widely outwards and much upwards.
(19) There are ne vesicule seminales. 3 |

(20) The uterus is two-horned.

(21) The placenta is deciduate.

(22) It is almost always zonary.

§ 21. The order Carnivora consists of a variety of genera forming

fi (WW s Za
wit iH) WRG

ply Lg
| UA
{ | HY :

Fig. 191.—SkvuxLt or tHE Panpa (Ailurus fulgens).

nine different families, which are grouped in three sets or SUB-ORDERS.
One of these sub-orders is named Cynorpga, and it contains only
the family of dogs, wolves, jackals, and foxes—the family Canide.
The second sub-order is called ArcromeEa, and it embraces the
family of Bears, Urside, and the family of Racoons, Coati-mondis,
Kinkajous, with the genus Bassaris—a family called Procyonide.

- contains four families.

CHAP. xitI.] THE CAT’S PLACE IN NATURE. 475
It also contains a third small family, Adduride, containing only the
Panda (Ailurus), and, perhaps, Ailuropus.* It comprises, fourthly
and lastly, the large family of Weasels and Otters, called Mustelide.

The third sub-order of Carnivora is termed AXLUROIDEA, and it
One of these is the large family of Civets—
Viverride ; another—Hyenide—is made up of the Hyenas, with
the aberrant Hyzena-like form Proteles. The third—Cryptoproctide
—contains the singular Madagascar animal the Foussa, and the
fourth and last family is the family of Cats, Felide.

§ 22. If we compare the cat's suB-oRDER -7‘luroidea with the
Arctoidea, we find that some Arctoids differ strangely from the cat,
especially the aquatic kinds, such as the otter, and above all the sea-

he OW

——————.

————SSS———

Fig. 192.—SKULL oF THE Bear (Ursus arctos).

otter. Many, like the bear and badger, are completely plantigrade.
Some have teeth which are not at all sectorial, as the bears, coati
and Ailurus; while others, as the glutton (Gu/o), have teeth which
much resemble the cat’s in structure. There is at least one hinder
tubercular molar above and below, so that there are two true molars
in the lower jaw.t In size the Arctoidea range from the smallest
weasel to the grisly bear. Some Arctoids are frugivorous animals,
as the sloth bear; others are most blood-thirsty, as the weasels,
ferrets, and glutton.

With such varieties of form and habit, it is not surprising that
good positive characters by which the species of a group so various
may be united together, and at the same time divided off from the
other sub-orders, are difficult to find. Rather, perhaps, is it sur-
prising that any should be found at all: Yet good distinctive
characters of a more or less recondite kind have been established.+

* See Milne-Edwards’s Recherches des
Mammiferes, 1874, p. 321, plates 50 and
56. ‘‘ Ailuropus” is a curious mammal
(intermediate in some respects between
the Panda arid the bears), which was dis-
covered in Thibet by the Rev. Pére

David, the well-known French Lazarist
Missionary.

t With the exception of the Pata-
gonian weasel, called Lyncodon.

# Partly by. the ‘late, Ma.) Hen:
Turner {too soon lost to science—a victim
to a dissecting wound), and secondly by
Professor Flower, F.R.S. See the Pro-
ceedings of the Zoological Society for
1848, p. 63 ; and for 1869, p. 4.

CT I A I

476 THE OAT. [omAP, xm,

If we examine the basis cranii of a bear (Fig. 193) we see that its

auditory bulla consists of a single bone, instead of two as in the cat.

It is but little prominent, but is much prolonged outwards as the

Fig. 193.—Part or Basis CRANII OF BEAR (Flower).

a. Posterior opening of ali-sphenoid canal. ' round the skull to re-enter the skull at this

a’. Anterior opening of same canal. foramen.

ce. Condyloid foramen. g. Glenoid foramen.

car. Carotid foramen, l. Foramen lacerum posterius.
e. Eustachian canal, m. Mastoid process.

Immediately above the right-hand end of the ma. Meatus auditorius externus..
line leading from the letter ¢, is a large .| o. Foramen ovale.
opening—the foramen lacerum anterius— | . Par-occipital process.
at which the carotid artery reappears, after s. Stylo-mastoid foramen. .
having traversed the petrosal, and bending

floor of the bony meatus auditorius externus(ma). Towards its
hinder inner end is a considerable foramen (car) for the internal
carotid artery, which here enters the petrosal, and having traversed

a ee

. 5
. |

oa

if

CHAP, XIII, | THE CAT’S PLACE IN NATURE. 477

it, emerges at the foramen lacerum anterius (just within and
behind the opening of the Eustachian canal), and bending round
re-enters the skull, in a backward direction, at the same foramen.
The paroccipital process (p) is somewhat triangular, and projects
downwards, outwards and backwards, standing quite aloof from the
bulla. The mastoid process (m) is widely separated from the par-
occipital, and is more or less prominent. The condyloid foramen (c)
can be plainly seen, and is not sunk into a common opening with
the foramen lacerum pvsterius. A foramen which gives exit to a
vein—the foramen glenoideum (y)—1s conspicuous just in front of the
meatus auditorius externus. A large canal is formed by the ali-
sphenoid, which throws out a lamina of bone to embrace the external
carotid artery. The passage thus enclosed is (as has been before

Fig. 194.—VertTicaL SECTION THROUGH TYMPANIC CAVITY OF BEAR (Flower).

am. Meatus auditorius externus. g. Glenoid canal leading to glenoid foramen.
BO. Basi-occipital. Sq. Squamosal.

Car. Carotid canal. T. Tympanic bone.

e. Eustachian canal. t. Tympanic ring.

mentioned) called the alisphenoid canal. Its posterior aperture (a)
is its own exclusively, but its anterior opening (@’) includes within
it that of the foramen rotundum.

When the auditory bulla is seen in section (Fig. 194), the simplicity
of its cavity is apparent.

The above-given cranial characters are. with the exception of that
of the presence of an alisphenoid canal and of the emergence
anteriorly of the internal carotid artery, characters of the whole of
the Arctoidea,* and to them may be added the further distinctions,
that there is no cecum whatever to the intestinal canal; that the
penis contains a large bone, which is not grooved, but which is dilated

* Certain exceptional details are presented by Ailuropus.

THE CAT.

Fig. 196.—SKULL oF Wour (Flower).

a. Posterior opening of ali-sphenoid canal.

a’. Its anterior opening.

am. Meatus auditorius externus.

ec. Condyloid foramen.

‘car. Carotid foramen.

é. Eustachian canal.

Above the right-hand end of the line which
leads from the letter -c, is the foramen

lacerum anterius, where the internal carotid
emerges, and then doubling back, re-enters
the cranium.

g. Glenoid foramen.

l. Foramen lacerum posterius

m. Mastoid foramen.

o. Foraien ovale.

p. Par-occipital process.

|
f
}
4
:
‘

Ce ee ee ee eee ee ee ee eee

CHAP, XIII] THE CAT’S PLACE IN NATURE. 479.

behind and bilobed in front; that there are no Cowper’s glands, and
that the prostate is rudimentary, cr exists only as a thickening of
the wall of the urethra, and does nc: form a distinct prominence.
The sub-order of dog-like creatures, the Cynoidea—which contains
but one family, Canide—differs strikingly from the cat's sub-order.
The Cynoids have two posterior tubercular molars above and below, and
their normal dentition consists of four premolars and two- molars in
the upper jaw, and four premolars and three molars in the lower jaw ;
though one singular form, O¢ocyon, has four premolars and three
molars on each side of each jaw. If we examine the basis cranii
we find a smooth, rounded and simple auditory bulla, but neither
does it send out externally so prolonged a process (Fig. 196, am) for
the meatus auditorius externus, as in the Arctoidea, nor is the carotid
foramen (car), though of good size, distinctly visible on its imner
border, for that foramen is, as it were, withdrawn within the
foramen lacerum posterius, into which it opens. Nevertheless, the

Fig. 197.—SectTIon or AuDITORY BuLia oF Dow (Flower).

am. Meatus auditorius externus. s. Septum.

BO. Basi-occipital. Sq. Squainosal.
car. Carotid canal T. Tympanic bone.
e. Eustachian canal. t. Tympanic ring.

g. Glenoid canal.

internal carotid follows the same course and emerges anteriorly
(there doubling backwards), as in the bears. The paroccipital
process (p) is long and projecting, and its anterior surface is more
applied against the bulla than in the Arctoid sub-order. The mastoid
(m) is distinct, but small. Both the condyloid and glenoid foramens
are very conspicuous, the former opening upon a bony ridge, and
being quite distinct from the foramen lacerum posterius. There is
a well-developed alisphenoid canal (a, a). When a section is made
of the bulla (Fig. 197) a very incomplete septum (s) may be seen to
spring from its anterior wall, in the same position as that in which
we saw the complete septum of the cat to take origin.

These cranial characters are possessed by all the Cynoidea, as are
also the following ones :—The cecum is not only present, but rather
elongated, and almost always folded on itself. The bone of the

ee ER CATO O° faa

penis is straight, wide, depressed and grooved. There are no
Cowper’s glands, but there 1s a salient prostate.

Finally, we come to the cat’s sub-order, the AXLUROIDEA. Thera
the following characters (which we have already seen to exist in the
cat) exist universally, so far as the structure of its component species
is known.

(1) The auditory bulla is much dilated, smooth, rounded, and
generally divided into two chambers bv a septum.

mi

y

A

NN
Sat

wil eG,
\ pen MBs 1.

a TT , uu

se CAO ENUTTTUONVOOYT VO TUOE oP

Fig. 198.—SKULL AND DENTITION OF PARADOXURUS CROSSII.

(2) The bony meatus auditorius externus is short, and only
produced in front, or else is imperfectly ossified below.

(3) The paroccipital process is, as it were, flattened against the
auditory bulla, to which it is much more closely applied
than it is in the Cynoidea.

(4) The mastoid is never salient, and often not to be distin-
guished.

4

SRE aE) ‘i be te hs been ae:

cHar, x1.) THE CATS PLACE IN NATURE. 481

(5) The carotid canal is generally small, and the foramen lead-
ing to it inconspicuous.

(6) The condyloid foramen almost always opens into the foramen
lacerum posterius, and is therefore inconspicuous and con-
cealed.

(7) There is generally no glenoid foramen.

(8) The caecum is small and simple, and may occasionally be absent.

(9) The bone of the penis is almost always small and irregularly
shaped, and may be wanting.

(10) There are Cowper’s glands.

(11) There is a salient, lobed prostate.

(12) The teeth are never as tubercular as in the dogs and bears.
(13) An ali-sphenoid canal may be present or absent.

§ 23. In considering creatures which make up the cat’s own sub-

Fig. 199.—THeE AFRICAN CIiveT (Viwrra civetta) Fig. 200.—THE PARADOXURE (Paradorurus
(Flower). bondar) (Flower).
a. Ali-sphenoid canal. . Eustachian canal.
am. Meatus auditorius externus. ‘ Forainen lacerum posterius.
c. Condyloid foramen. o. Foramen ovale.
car, Carotid foramen. p- Par-occipital process.

order, it may be well to begin with the large family of the Viverripa.
This family includes a large number of forms, such as the African
civet and the Asiatic zibet (Viverra) ; the genets (Genetta), of which
one is an inhabitant of Europe; the paradoxures (Paradoxurus),
animals inhabiting Eastern India : the ichneumons (Herpestes) ; the
suricate (Ryzena); the mangue (Crossarchus) ; ; the animal named
Cynictis; the long-whiskered, short-tailed creature, Cynogale, and
II

489 | THE CAT. [cHAR, xm.

the large, arboreal, and in many respects exceptional Viverrine—the
Binturong (Arctitis).

The Viverride have a rather elongated head and muzzle, and they
have almost always two tubercular molars in the upper jaw and one
im the lower. Of true molars (as distinguished from premolars)
there are two above and two below on each side of each jaw. The
teeth may vary in shape, from largely sectorial—though never as in
the cats—to mainly tubercular. The cecum is small and simple, or
may be, by very rare exception, absent. Cowper's glands are
present, and the prostate gland is salient and lobed. The penis
may be devoid of any bone, or if there is one it is small and
irregular in shape. Often, as in the civet, there are largely
developed scent-glands. a

In the cranial characters the whole of the Viverrmes show great

Fig. 201.—Ture Icnyeumon (Hervpestes ichnewmon) (Flower).

a. Posterior end of ali-sphenoid canal. e. Eustachian canal

a’. Its anterior termination. 1. Foramen lacerum posterius.
am. Meatus auditorius externus, m. Mastoid.

c. Condyloid foramen. o. Foramen ovale.

car, Carotid foramen. yp. Par-occipital process.

uniformity. There is generally a distinct ali-sphenoid canal. The
auditory bulla is large, smooth and rounded, and consists of two
portions separated by a nearly complete septum, much as in the cat,
except that the chamber which corresponds with the inner chamber
of the cat’s bulla, is posterior in situation The carotid canal is
larger than in the cat, and may run through a canal in the petrosal
(as in Herpestes), or may be merely represented by a groove on
the inner side of the auditory bulla. In Herpestes and allied forms,
the artery, after emerging, runs along for a short distance before

re-entering the cranium. The par-occipital process is widened,
spread out, and closely applied to the posterior surface of the —

CHAP, XIII. | THE CATS PLACE IN NATURE. 483

auditory bulla, and the condyloid foramen is concealed within the
foramen lacerum posterius. There is either no glenoid foramen
or itis minute. The mastoid process is quite indistinct, or but little
prominent. The bony meatus auditorius externus is either very
short—extending but little outside the tympanic ring (as in Viverra,
Fig. 199)—or if, as in the Suricates, it is prolonged, its floor is
medianly fissured.

The next family is that of the Hyenas, Hyanipa, which also
contains the curious and aberrant South African mammal, the Aard-
vark (Proteles) an animal erroneously supposed by some naturalists
to be related to the dog.

In this family the teeth are either, as in the hyznas, remarkable
for their strength and cutting power, or, as in Profeles, for their
extreme werkness. In the hyzena there are four upper premolars,
all sectorial, especially the hindmost, which is much lke that of the
cat, as is also the minute, solitary upper tubercular molar. In the
lower jaw there are three premolars and one molar—all sectorial
like those of the cat, though less perfectly formed for cutting,
because the hyzena’s teeth are broader and stronger, and more suited
for the bone-crushing action in which they are employed. The
Aard-vark has four weak, small molar teeth in either jaw, each such
tooth being separated by a diastema from the tooth nearest to it.

As to the structure of the skull, the hyenas have a smooth, oval,
prominent bulla, which is perfectly simple within its cavity, not even
showing a trace of a septum for its division into two chambers.
Yet, as in the Viverrines, it is considerably more prominent posteriorly
than in front, so that if a septum was developed, the chambers would
probably be placed onein front andone behind. There is no ali-sphenoid
canal. The carotid foramen (Fig. 202, car) is small, and situated a -
little behind the middle of the inner margin of the bulla. The par-
occipital process 1s spread out over the posterior surface of the bulla,
but forms also a rounded prominence projecting b ckwards (p).
The mastoid process is also slightly prominent. The bony meatus
auditorius externus 1s short, yet the anterior portion of its floor is
produced outwards as a rather pointed process. The condyloid
foramen is concealed, and the glenoid foramen is minute or absent.

Proteles agrees with the hyenas in these cranial characters, except
that in it the bulla is divided by a septum into two chambers—one
being quite anterior and the other posterior—and that the mastoid
and paroccipital processes do not stand out from the skull. As to the
generative organs, Cowper’s glands and a salient prostate are present
in both Proteles and Hyena, while no bone has been observed in the
penis of either. In both, also, the cecum coli is simple and very
small, and there are large scent-glands. In both, also, there are
normally not less than fifteen dorsal vertebre.

The third family, Cryproprocrip#, contains only a single species
—namely, a fierce animal (of the size of a large cat) to which the
natives of Madagascar give the name “ Foussa.”

It is an animal much like a cat, but with alonger head. It has
I12

ae ee ee

484 THE CAT.

large ears and a long tail. Its claws are retractile, but it does not
walk like the cat on its toes, but applies nearly the whole plantar and
palmar surfaces to the ground. It may therefore be said to be
plantigrade. It was originally made known to science, and named
in a paper published by Mr. E. T. Bennett.* The young specimen
described by him came from Mr. Telfair of Mauritius, who declared

Fig. 202.—Hyana (Hyena striata) (Flower), ©

1. Foramen lacerum posterius.
m. Mastoid.

o. Foramen ovale.

. Par-occipital process.

am. Meatus auditorius externus.
c. Condyloid foramen.

car. Carotid foramen.

e. Eustachian canal.

it to be “the most savage creature of its size I ever met with; its
motions, power and activity are those of a tiger, and it has the same
appetite for blood and destruction of animal life.” :

Its teeth are very like those of the cat, save that it has an
additional premolar below and, for a time also, one above, but the
latter soon falls away.

The skull is more elongated, in proportion to its other dimensions,
than is that of the cat.

* In the Transactions of the Zoological Society, p. 137, plate 21.

cHap. xm.] THE OATS PLACE IN NATURE. 485

The basis cranti (Fig. 205) shows a distinct ali- sphenoid canal (a, a’)
and carotid foramen near the anterior end of the inner margin of the
bulla, which is divided by a septum into two chambers. The inner

|
;
pa
| )

Fig. 203.—THE Foussa (Crypteprocta jeroz).

of these chambers is quite posterior in situation, and the bulla is
much more prominent behind than in front. The paroccipital
' process is not prominent, but is applied to the bulla, and the mastoid

Fig. 204.—SkKUuLL oF Cryptoprocta ferox.

process does not project outwards. The condyloid foramen is con-
cealed, and there is no glenoid foramen.

The dorsal vertebree are thirteen in number, and the lumbar are
seven.

" 486 THE CAT.

The scapula is less rounded than that of the common cat, but
there is a largely-developed metacromion. The supra-condyloid
foramen of the humerus is extremely large. The metacarpals and
metatarsals are relatively shorter than in the cat. .The pollex is
more developed, but the hallux is very different, being completely

Fig. 205.—Basis CRANII OF Cryptoprocta ferox
(Flower).

a. Posterior opening of ali-sphenoid canal.
a’. Its anterior opening.

am. Meatus auditorius externus.

c. Condyloid foramen,

car. Carotid foramen. Fig. 206.—Tur Paps OF THE FEET OF THE
e. Eustachian canal. Foussa (Cryptoprocta ferox),

7. Foramen lacerum posterius.

o. Foramen ovale. _A. The sole of the fore-paw.

sp. Par-occipital process. B. The sole of the hind-paw.

formed, instead of being, as in the cat, a mere rudiment. It has a long
metatarsal and two phalanges, the distal end of the digit reaching
nearly to the distal end of the first phalanx of the adjacent toe.

The naked pads on the feet are much more extended than in the
eat,* in harmony with the almost quite plantigrade habit of the Foussa.
There is a long bone to the penis, compressed, slightly curved, not
grooved, but slightly dilated at each end, more so posteriorly.

The anatomy of the soft parts is, unfortunately, as yet unknown.

§ 24. Such being the nature of the families of the cat’s sub-order,

* See ante, Figs. 9 and 10, p. 25.

:
a

Oe a i

a oe oe

—~—S - see

:

’

cuar. xm.) THE CATS PLACE IN NATURE. 487

other than the family of cats themselves (Felide), we may now
contrast the latter (i.e, the Felide,) with each of the former.
The different kinds of cats all agree with the common cat in

Fig. 207.—ParT OF THE BASE OF THE SKULL OF THE TIGER (Felis tigris) A PORTION OF THF
AvuDITORY BULLA HAS BEEN REMOVED TO SHOW ITS INTERIOR. THE CAVITY OF THE
INNER OR POSTERIOR CHAMBER IS EXPOSED (Flower).

am. Meatus auditorius externus, o. Foramen ovale.

c. Condyloid foramen. p. Par-occipital process

car. Carotid foramen. : 7. Fenestra rotun :a.

e. Eustachian canal. s. Septum between the chambers.
i. Foramen lacerum posterius. * The aperture of communication.

m. Mastoid process.

structure, save as regards the details already pointed out in the last
chapter. We may then proceed to sum up the main points in which
the cat’s FAMILY differs from the other three families of the sub-
order Zluroidea, as follows.

488 | THE CAT. [cHaP. XL
The Frip# differ from the VivERRID#, in that in the Fehde: — ,
(1) The head is more rounded ; |
(2) The limbs are generally longer in proportion to the trunk ; —
(3) The claws are generally more completely retractile ;
(4) The teeth are more sectorial, and the premolars and
tubercular molars are fewer, there being never more than
one tubercular molar (an upper one) in any living species; —
(5) There are no conspicuous scent-glands ; an
(6) There is no ali-sphenoid canal savein certainextinct genera;
(7) The division of the bulla is hardly perceptible exteriorly,
% while the two chambers into which it is mternally divided
Fs are not placed one quite behind the other ;
(8) The carotid foramen is always very small, and the carotid
canal indistinct, except in some extinct genera ;

Fig. 208.—SEcTION OF THE AUDITORY BULLA OF THE TIGER (Flower).

4
am. Meatus auditorius externus. * The aperture of communication between the
BO. Basi-occipital, chambers.
e. Eustachian canal. Pt. Petrosal. 1
ac. The inner chambers. s. Septum. :
oc, The outer chamber. Sq. Squamosa "

(9) The par-occipital process (though applied to the bulla) may,
in large species, develope a marked process ;
(10) The meatus auditorius externus is never medianly fissured -
below.

The Fre.iv# differ from the Hy nips in that:
(1) Their head is more rounded ;
(2) Their claws are retractile ;
(3) The body does not droop so much posteriorly ;
(4) The teeth are more perfectly sectorial in form ;
(5) The premolars are less numerous ;

CHAP, XIII. } THE CAT’S PLACE IN NATURE. 489

F (6) The bulla is, at least in existing species, divided into two
chambers, which are not placed completely one behind the
other;
(7) The bulla is most prominent towards its inner, not towards
- its hinder border ;
(8) The bony meatus auditorius externus is not produced an-
teriorly into an outstanding process ; |
(9) There may be a small bone to the penis;
(10) There are no conspicuous scent-glands ;
(11) There are only thirteen dorsal vertebre.

The Ferip# differ further from the truzE Hynas (i.e, the
Hyenas as distinguished from Prote/es) in that:

(1) Their teeth are less powerfully formed for crushing ;

(2) The bulla is divided by a septum ;

(3) The carotid foramen is generally still less conspicuous.

They further differ from Proteles in that:

| (1) Their teeth are much stronger and larger relatively, and
more closely approximate ; :

(2) The chambers of the bulla are not quite one behind the
other.

The Friipz differ from the Cryproprocripz in that :
(1) They are quite digitigrade ;
| (2) Their skull is relatively shorter and rounder ;
J (3) Their premolars are (except in Archelurus) less numerous ;
(4) The chambers of the bulla are not quite one behind the
other ;
(5) There is no ali-sphenoid canal, save in some extinct genera;
(6) The supra-condyloid foramen is of moderate size ;
(7) The metacarpals and metatarsals are relatively longer ;
(8) The pollex is very small, and the hallux a mere rudiment ;
(9) The naked pads of the feet are much less extended ;
(10) The bone of the penis is small.

§ 25. We have now before us as complete a statement as the
author can give of the relations which exist between the cat’s family
and all other living organisms whatsoever.

As to the subordinate groups contamed within the cat's own
family, 7.e., its genera, we saw in the last chapter that all known
eats living and extinct can be arranged in eleven sets of kinds, to
which the names Felis, Cynelurus, Alurodon, Archelurus, Dinictis,
Nimravus, Pseudelurus, Hoplophoneus, Pogonodon, Macherodus, and
Eusmilus, have been given.’ We now see what was meant by saying
that these groups have each the value of a “genus.” As to the
relations which exist between the feline genera, we now also see that
the exceptional characters presented by Dinictis and Archelurus are
peculiarities which cause those genera to have a certain resemblance
to the Viverrine family.

_In the last chapter we recognized the fact that an extreme

4

490 THE CAT. — ferap, xa,

specialization of structure is presented by Macherodus and Eusmilus,
and that Cynelurus is the most exceptional form amongst living
felines, and one in which some of the distinctive characters of its
family (e.g., the retractility of the claws), are poorly developed.
The cat's genus, Felis, is one which, while it well exemplifies the
characters of the family to which it belongs, yet does not exhibit
any of those characters developed either in an extreme or in an
aberrant manner. ‘This statement needs some explanation. Every
group of animals containing various species consists of certain kinds,
which are more or less alike, and differ but little from an ideal
standard which is the type of such group. Such kinds are
normal forms. Besides these, there are generally certain other
kinds which are peculiarly modified in one way or another, depart-
ing more or less widely from the normal structure. Such divergent
kinds are said to be aberrant or abnormal. Also both “ normal”
and ‘aberrant’? forms may be either what is called specialized or
generalized. ‘‘Specialized”’ creatures are such as have an ex-
ceptional organization of a definite kind. ‘‘Generalized”’ creatures
are such as resemble the general run of animals to which they are
more or less closely related, but have the distinctive characters of
their group poorly developed. But besides the specialized and

generalized normal forms, there may be other normal forms which _

are neither of these, but adhere closely to the type and express it in
its intensity, yet without any one-sided development of it. These
are TYPICAL Forms. ‘The full meaning of these terms can only be
made clear by examples, for which it is necessary to refer to some
other group of animals with which the reader may be acquainted,
or with which he can easily become so. Let us then take, as examples,
species of the well-defined group of ruminating beasts. Amongst
them we have creatures which adhere to the normal structure, but
yet its characteristic features are in them but poorly developed.
They are then generalized normal forms, as, e.g., that small South
American deer, the yenada or pudu (Pudu humilis). Others, which
adhere to the normal structure, may carry it to an intense but some-
what one-sided degree of development. Such would be specialized
normal forms, as, e.g., the elk or the four-horned antelope. Others
again may diverge from the general type in the direction of other
creatures outside their group. Such would be generalized aberrant

. forms, such as the camel and llama, or as the chevrotains; whilst

others may diverge from such type in a special direction of their
own, and such would be called specialized aberrant forms, as, €.9-
the giraffe. |

Finally, others will be normal, and yet with the characters special
to the group strongly developed, 7.e., they will be typical forms, as,
e.g., the red deer or the Indian antelope.

To apply these remarks to the Felide, we have an example of
a “generalized normal form” in the cheetah, Cynelurus. The lon
is an example of a ‘specialized normal form.” For a “ generalized
aberrant form” we must have recourse to fossils, such as Dinetis,

ee ee ee a a as —

eS = ™ .

omar, xu] THE CATS PLACE IN NATURE. 491

and, above all, Archelurus, as also for specialized aberrant forms,
of which Husmilus and Macherodus smilodon afford us. excellent
examples. Finally, as the expression of the typical or fully-developed
normal form of the cat’s family, we have the species which go to
make up the maneless cats of the typical genus Felis, of which Fedis
catus will stand as a very good example.

But if the cat is thus the typical genus of its fanily, 3 in what
relation may its family be said to stand to the other families of its
order thus considered ? Of all the families of that order, the dog’s
family, Canide, seems to be the most generalized aberrant one. For
while it possesses the general characters of its order without carrying
them to an intense degree, it shows certain resemblances to forms
outside its order.*

The bears, on the other hand, are specialized aberrant forms, as
they depart from the normal standard of the order in a special
direction of their own, as also do the otters and several other forms
of Carnivora.t

As to the mass of the Mustilide and Viverride, they may be
considered to be normally generalized carnivores, since they possess
the ordinary carnivorous characters moderately developed. It is not
easy to poimt out any certainly normally specialized families—any
family, that is, which has the characters of the order in an intense
degree, but developed, as it were, in a one-sided manner. Such
characters seem only present in certain exceptional Felide, such as
Macherodus and Eusmilus. If so, then the Felide, as a whole,

’ must be held to be the typical family of the whole order; for they

earry the carnivorous type of structure to an intense degree, but one
which is in the direct line of development which the order Carnivora
has followed. Carnivorous beasts generally have sharp claws, often
more or less retractile, but none have them so perfectly developed in
these respects as have the cats. Almost all carnivorous beasts have
teeth more or less well adapted for killing prey and cutting flesh, but
none have their teeth so admirably adapted for these purposes as
have the cats. The cats are then carnivora par excellence, and they

_ carry out the type of their order tv its mghest-known and most

perfectly harmonious expression.

But the cats are not only such highly-developed Carnivora. Some-
thing may also be said in favour of their being the highest of mam-
mals—the very flower and culmination of the mammalian animal
tree.

Spontaneous activity and sensitiveness are the special characteristics
of animal life, and with both these powers the cats are largely endowed.
We have recognized the perfection of their organs of movement, and
that of the very substance of their bones and muscles, as well as the
great perfection of their special senses. It may be objected, how-
ever, that the activities and sense perceptions of certain other beasts

* £.g., to certain marsupials. | leptes), the binturong (Arctitis), and also
Such as e. g. the kinkajou (Cerco- | Proteles.

492 THE OAT.

are, in their own various ways, as highly developed as are those of —

the Felide. It is certainly very true that it is only through the
possession of perfectly-formed bones and muscles, of a delicate sense
of hearing, or of far-reaching vision, that antelopes, hares, and such
creatures, escape their carnivorous pursuers. But then they use
their organization for escape. The organization of the cat-tribe may
then be deemed superior, because it is not only excellent in itself,
but because it is fitted to dominate the excellences of other beasts.
Thus considered, the Carnivora would rank first amongst mam-
mals, and the cats would rank first amongst the Carnivora. Man,
however, is a mammal, and therefore to affirm this would be to
affirm the inferiority of our own species. But man’s superiority is
mental, it resides in his intellect, not in his peculiarly-formed great
toe, hand, pelvis, or other corporeal peculiarity, Man is to be
regarded in two lights—as a truly intellectual being, and as animal
with a certain organization. Viewed in the firsb mode, he stands quite
apart from and outside of the whole visible ereation, and has simply
no place whatever in any scheme of biological classification. Con-
sidered merely in his capacity 1s an animal, he has a very definite
place in such a scheme, but it is by no means certain that his place
is at its summit. Our powers of locomotion and of sense perception
are quite inferior to those of very many beasts, and though our brain
is large, both absolutely and relatively, yet such are the variations
in this respect, presented by animals of different groups and by
different animals of the same group, that the naturalist would be a
hold one who should venture to affirm that a brain-classification of
vertebrate animals—to say nothing of the Invertebrata—would be
a satisfactory one. The close bodily resemblance of apes to man
gives them then no just claim to a rank above that of the Carnivora,
since such a claim only reposes on their bodily resemblance to our-
selves. As to their intelligence, no evidence seems to be forthcoming
that it is superior to that of the dog or of the elephant, though their
close likeness to ourselves gives to their tricks a deceptive appearance
of rationality which we must always be careful adequately to discount
if we would correctly estimate their real worth.

The apes are, like the dogs and the elephant, superior perhaps
in cognitive psychical endowments to the cat, but yet any such dif-
ferences between these animals are merely differences of degree and
not of kind, like that which we have seen to exist between the cat-
mind and our own.

It may, perhaps, be objected to these observations, that biological
classification is (as has been pomted out in this work) a morpho-
logical and not a physiological classification; that 1t reposes not on
function but on structure. This is most true, and nothing could
well be more preposterous than a proposal to classify all creatures
according to their psychical endowments. Such a classification would
tear away ants and bees from insects obviously like them, and associate
them with beavers, and it would utterly confuse all biological science.

But though it is true that animals must be classified according to

3
¥
4
:

al te it

q CHAP, XIII. ] THE CAT’S PLACE IN NATURE. 493

their structural characters, yet it is obvious that the value of and the
relations between structural characters themselves, cannot be con-
sidered except by reference to conditions which are not structural.
Therefore, as in considering the question, which of all the groups of |
animals is to rank highest, we must estimate the value of their
structural characters, we must necessarily, in so doing, go beyond
facts of structure themselves, i.¢., we must refer to the purposes they
serve, that is to physiology.

It is therefore true that “something may be said in favour of cats
being the highest of mammals,” if: man is considered merely in his
animal capacity—in which alone he can be brought into comparison
with other organisms.

But whether or not this eminence be allowed to the cat, there can
be no question but that it is the most highly-developed type of
carnivorous mammalian lfe—the most perfect embodiment of the
idea of a “ beast of prey.”’ Such, then, 1s certainly the ‘‘cat’s PLACE
IN NaATURE:” Itisa member of the typical genus of the typical
family of carnivorous placental mammals—mammals being the suck-
giving, tied-brained * class of back-boned animals.

* J,¢., with their cerebral hemispheres united by means of a corpus callosum.

CHAPTER XIV.

THE CAT’S HEXICOLOGY.

§ 1. Every animal has definite relations to the various influences
which on all sides surround and act upon it, and which constitute
what is called its “ENVIRONMENT.” Every animal has existed for a
certain definite time and within ee: limits of space. It has been
favoured, or the reverse, by the physical forces (that is, by conditions
of climate, including temperature, moisture, &c.), and its existence
has been related in various ways to that of other living creatures.
The science of Hexicology 1s (as was shortly stated at the end of the
first chapter) the study of all these more or less complex relations.

§ 2. The cat-group, Felide, has now to be considered as thus
related to its environment, and we may consider first its relations
with PHYSICAL CONDITIONS,

As to heat, that the domestic cat loves warmth is what everyone
must have observed. Almost all the larger cats, and the great bulk
of the smaller kinds, are inhabitants of the warmest regions of the
globe. No cat dwells in the extreme north with the polar bear,
while no region is too hot for certain species of Fedis.

Yet we have seen that the Ounce and Felis scripta are dwellers
on the snowy heights of Thibet, and that the tiger ranges to the
Amoor river, while the group of lynxes—the caracal excepted—are
northern forms, two varieties, possibly two species, being found in
Scandinavia and Canada. Moreover, in earlier times, existing
species, such as the lion, extended into colder climes than ‘they now
inhabit, while in the earliest prehistoric human period that great cat,
Felis spelea, was an inhabitant of England, protected perhaps by a
very ample furry coat, such as that “which protects the Ounce of
Thibet to-day. Yet the differences as to fur are after all very small
compared with the differences as to climate. Therefore, the feline race
being thus able to live in countries of very different temperatures,
must have a considerable internal power of regulating and sustain-
ing the temperature of the body, and concomitantly with this faculty
we find that no cat falls into a winter sleep, 7.¢., no cat hibernates.

As to light, though the great majority of cats dwell in climates
where daylight is intense, yet they mostly remain in repose while
the sun is above the horizon, and prowl about in twilight or at night.

Still certain kinds are diurnal, and from observations made at the

:
|

CHAP, XIV. ] THE CATS HEXICOLOGY. 495

Zoological Gardens it seems that it is (as might be expected) the
eats with pupils which can be contracted into minute linear openings
which are the most nocturnal. Yet the tiger in spite of its circular
pupils seeks its prey at night.

With regard to moisture, though no cats are aquatic, and though
none take to the water save with more or less (generally with
extreme) reluctance, yet many (like the tiger and the jaguar)
habitually haunt the banks of rivers or pools, because they more
easily obtain their prey in such situations. Certain kinds, more-
over, live more or less upon fish (as I’. viverrina), and the domestic
cat's relish for fish is very marked. Yet the Felide are a family of
either distinctly terrestrial or else arboreal mammals.

The Felde as a rule do not drink much water, but it seems* that
the smaller kinds drink more in proportion to their size than do the

_. larger species. The lion is found in desert regions, and when in

captivity drinks very little.

As to the degree of rarity of the atmosphere which they can
endure, we have seen that the Ounce ranges from 9,000 to 18,000
feet—the latter altitude being one at which man breathes with much
difficulty.

§ 3. The GEOGRAPHICAL RELATIONS of the cat-family are instructive
and somewhat complex. As was long ago remarked by Buffon, the
great cats of the Old and New Worlds are markedly distinct. The
hor, tiger, leopard, ounce, clouded tiger, cheetah, and caracal, with
a variety of smaller cats, are all inhabitants of the Old World only.
The puma, jaguar, ocelot, jaguarondi, eyra, collocollo, the pampas, and
one or two other cats are exclusively inhabitants of the New World.
It is only amongst the lynxes that we find a form which is common
to both these worlds—the Canadian and North European lynxes being
probably but varieties of one species. With this exception no wild
cat found in America is also found out of it. The New World is not
so rich in cat-species as 1s the Old, nor do its largest kinds, the puma
and jaguar, equal the largest kinds of Africa and Asia.

A further geographical distinction may be drawn amongst Ameri-
can cats themselves. Of its varieties of lynx, /. maculata descends
as far south as Mexico, while the puma alone extends to high latitudes
in both North and South America. We may therefore distinguish the
region north of Arkansas and Louisiana as the region of lynxes and
the puma; while Mexico, with parts of Arkansas and Louisiana, and

ali America south of Mexico may be said to be the region of the

puma, jaguar, ocelot, and all other American cats.

Strange to say the West Indian Islands, though some of them, as
Cuba and Hayti, seem admirably suited to shelter and support
species of Fe/ide, are entirely destitute of them.

In the Old World, certain other geographical divisions may be
similarly established. We have seen that the lion, leopard, caracal,

* Mr. A. D. Bartlett has kindly sup- | species of the cat family.
plied me with information as to the t Trinidad is to be reckoned as a part
drinking habit in continement of different | of the South American continent.

496 THE CAT.

and common cheetah certainly exist in both Asia and Africa. With
these exceptions, however, the two tropical continents of the Old
World seem to have a quite different cat population. :

In Africa we have, peculiar to it, the serval with its allied species
or varieties, F’. rutila, F’. neglecta, F’. servalina, F. celidogaster, and
F’. senegalenis, as also F’. caligata and C. lanea. Moreover, though the
serval is said to occur in Algeria, and F’. caligata is a North African
form, the other varieties are found in Guinea, Gambia, Sierra Leone,
and Senegal. Africa south of the Sahara may therefore be considered
as richer in cats than the more northern portion of that continent,
especially as it is south of the Sahara that the kinds common to
Africa and Asia are principally found. There is reason, moreover,
(from the analegy of the geographical distribution of other animals)
to suspect that the felines now found north, of the Sahara may be
immigrants from the more southern portion of Africa. :

Just as in America we found the West Indies to be devoid of
cats, so, strange to say, the great is!and of Madagascar, jn spite ot
its forests and numerous animal population, is similarly without a
single species of cat.

In Asia we find a further subdivision possible between its northern,
south-western, and south-eastern portions. In the north, ¢.e., north
of the Himalayas, we have the ounce, the tiger, a lynx (£7, isa- -
bellina), the steppe cat (F. Manul), the leopard (in Japan), and
the species or varieties before described as &. microtis, F. tristis,

F. scripta, and F. chinensis.

In South-western Asia we have the lion, with certain forms
common to this and other Asiatic regions, such as the tiger, leopard, _
Indian wild cat, and some others.

In South-eastern Asia we have the clouded tiger (F’. macrocelis),
FI. planiceps, F. badia, F. marmorata, F. megalotis, F. aurata, F.
minuta, with the tiger, leopard, and others common to other
regions.

The tiger, as we have seen, descends through the Indian Archi-
pelago, with the exception of Borneo, down to the island of Bah,
which is its furthest limit south. ;

In the immense and hot island of New Guinea, in Celebes,* in
Australia, and in New Zealand, there is no single indigenous cat of
any kind. ,

In Europe, we have two species of lynx and also the wild cat,
while within the historical period we had the lion also. Thus the
world may be divided according to the distribution of its cat-popu-
lation into two great divisions—those of the Old and New Worlds

* Miiller (Verhand. over de Natuur- | unlikely that one should be found in that
lijke Geschiedenis Zool. Leyden, 1844, | island, and Dr. A. B. Meyer, of Dresden,
Part I., Over de Zoogdiernen van den | writestome tosay that the animal meant
Indischen Archipel., p. 54) speaks of | is probably a Paradoxurus, which cer-
reports received from natives of the exist- | tainly exists there. He also tells me he
ence of a panther and wild cat in Celebes. | obtained two specimens of Felis minuta
Though it is not impossible that there | from Zebu, in the Philippine Islands,
may be a cat in Celehes, it is extremely | J’. minuta also inhabits Borneo.

CHAP. XIV.] THE CATS HEXICOLOGY. 497

respectively, with further subdivisions into: (1) America north of
Arkansas and Louisiana; (2) Arkansas and Louisiana, Mexico,
Central and Southern America; (3) Africa, the part north of the
Sahara being somewhat distinct ; (4) Asia north of the Himalaya ;
(5) Southern Asia—slightly separable into (A) a south-western, and
(B) a south-eastern portion; and, finally, (6) Europe. A certain
affinity exists between Europe and Northern Asia on the one hand,
and in a less degree, between Europe and North America on the
other; while South-western Asia has a certain affinity to Africa.
The West Indies, Madagascar, the Philippines, the Moluccas, New
Guinea, Australia, and New Zealand, are all devoid of any natural
feline population, while Asia is certainly the great home of the cat

_ family. .

Such being the geography of the Fedde, what relation does it
bear to the geography of other animals ?

§ 4. It has been found that (regard being had to the geographical
distribution of animals of all kinds) the earth’s surface may be most
conveniently divided zoologically (the polar regions not being included)
into the six following regions: (1) Palee-arctic; (2) Ne-arctic; (3)
Indian ; (4) Ethiopian; (5) Nec-tropical; and (6) Australian.

The PaL®-aRcTic REGION includes all Europe, with Iceland and
the Azores ; Africa, north of the Sahara, with the Canaries and Cape
Verde Islands; and all Asia (with Japan), north of the Himalaya
and the tropic of Cancer, except the southern part of China, Assam,
and some parts adjacent, which belong to the Indian region.

Characteristic of this region are horses and asses, mules, sheep,
goats, camels, fallow-deer, the ibex, the chamois, many warblers,
grouse, pheasants, tits, magpies, true vipers, chameleons, and various
Batrachians, such as the gigantic salamander, the land salamander,
the proteus, and various other efts, as well as many frogs and toads.
Twenty genera of fresh-water fishes (belonging mostly to the carp,
perch, and salmon families) are peculiar to this region. As to
insects, there are fifteen peculiar genera of butterflies. Here and
there are also found certain monkeys, flying foxes, the genet, hyzena,
polar bear, walrus, and hyrax.

This zoological region does not exactly correspond with our feline
geographical divisions, yet it to a certain degree harmonizes with
them, embracing, as it does, the European, North Asiatic, and North
African feline divisions in one.

The Ne-arcric REGIon of general zoological geography, includes
North America down to and (on elevated land) somewhat south of
the tropic of Cancer. This region is destitute of apes, hedgehogs,
wild horses, asses, swine, true oxen, goats, or dormice. It has
hardly any sheep or antelopes, and no flycatchers, starlings, true
erouse, or pheasants. On the other hand, it has peculiar forms,
such as racoons, peccaries, certain antelopes, certain pouched rats,
the prairie dog, certain porcupines, and also turkeys, crested quails,
tufted grouse, and passenger-pigeons, the mocking-bird, the canvas-
backed duck, and some humming birds. Besides these, it has rattle-

KK

498 THE CAT. [CHAP. XIV.
snakes, the curious lizards, Chirotes and Phrynosoma, and various

‘terrapins, besides alligators, but no chameleons or true vipers. The
tailed-Batrachians have their head-quarters in this region. Besides
other genera peculiar to it may be mentioned: the Menopoma,
Menobranchus, Amphinama, and Siren, as well as the axolotl. Cer-
tain ganoid fishes are also noteworthy, such as Amia, the bony pike
(Lepidosteus), and Scaphirhynchus.

This region mostly corresponds with our North American eat-
region, but extends further southwards, as our North American
feline region excludes Mexico and Southern Texas, and even parts of
Louisiana and Arkansas. |

‘The OrientTaL or INDIAN REGION embraces India, Burmah,
Southern China, the Malay Peninsula and Archipelago, including the
Philippine Islands and the island of Bally, but excluding Lombok,
Celebes, and the islands south and east of these. Amongst its animal
inhabitants are many monkeys. There are also many deer, and but
few antelopes.* Elephants and rhinoceroses are found there, and also
chevrotains (Tragu/us), pangolins, and a tapir. Amongst its birds
may be noted the peacock, the argus and fire-backed pheasants, true
fowls, hornbills, bee-eaters, many pigeons, parrots, cuckoos, and wood-
peckers, and a few sunbirds (Nectarinide). As to reptiles, we find
a multitude of snakes—amongst them the cobras and curious Uro-
peltide, or shield-tailed snakes—but no rattle-snakes—with many
lizards, including chameleons and the little flying-dragon (Draco).
We also find crocodiles and gavials, but no alligators, while in the
Indian Ocean we find sea-snakes. Frogs and toads are numerous,
but efts are wanting, save as immigrants from the Pale-arctie region.
We, however, meet with the singular Ophiomorpha, or snake-like
creatures of the frog’s class, 7.e., of the class Batrachia.

This region then is a very well defined one, and corresponds with
our South-eastern Asiatic feline region. It is remarkable that the
island of Bally is the extreme limit of the Indian general zoological
region as well as of the South Asiatic feline region. |

The ErHiop1an REGION is made up of Africa, south of the Sahara,
with Arabia, the Seychelle islands, Mauritius, and Madagascar. It
agrees with India in having elephants and rhinoceroses; but zebras,
quaggas, certain hogs, the hippopotamus, the giraffe, the aquatic
musk-deer, and Cape ant-eater (Orycteropus), are all peculiarly
African. Africa is also specially remarkable as the home of multi-
tudes of antelopes of many different kinds, great herds of which
range over its southern plains. There are, however, no bears, deer,
true oxen, goats, or sheep. Peacccks, pheasants, and jungle fowls
are also wanting amongst its birds, while in their place we find the
guinea fowls. The secretary bird, Baleniceps, the Balearic crane, and
ostrich, are forms peculiar to Africa, which is also the great home of
the weaver-birds and sun-birds. Reptiles abound—tortoises, lizards,
and snakes, amongst which latter (as in India) there are cobras, but

* Amongst them is the four-horned antelope.

——

CHAP. XIV. ] THE CATS HEXICOLOGY. 499

no rattle-snakes. Crocodiles exist, but neither alligators nor gavials.
There are no efts, but there are Ophiomorpha, and many frogs and
toads, Dactylethra being the most remarkable of the latter. Amongst -
fishes, we have the curious ganoid, Polypterus, and one form of
Lepidosiren. |

This general zoological region agrees with the corresponding feline
region, save that the latter is less distinct from that part of the con-
tinent which is north of the Sahara, and has nothing to do with the
islands above named. Madagascar, however, is remarkable, not
only for the absence of cats, but for possessing a very peculiar
animal population of lemurs and lemur-lke forms, and as the
home of that exceptionally cat-like Viverrine, the Foussa—Crypto-
procta ferox.

The NEo-TROPICAL REGION of general zoological geography comprises
America south of the tropic of Cancer, together with the West Indies,
and includes the greatest forest region in the world. It hasa number
of peculiar monkeys and bats, with two river-dolphins found nowhere
else. It has also the coati-mondi, kinkajou, and tapir; but there
are no elephants, rhinoceroses, horses, asses, or hippopotamuses.
There are peccaries also instead of hogs. Altogether devoid of
antelopes, goats, sheep, oxen, or camels, there are deer and llamas.

- Rodents abound, and there are many absolutely peculiar, such as
the paca, the viscacha, the chinchilla, the guinea-pig, and its

gigantic cousin, the capybara, preyed on by the jaguar. But the
neo-tropical region is remarkable for the presence of a group of
animals found nowhere else whatever. This is the group comprising
the sloths, ant-eaters, and armadillos. Opossums also are very
numerous, and of many species of different sizes, and seem to take
the place of the insect-eating beasts Jnsectivora), which are here
conspicuous by their absence. Amongst Birds, we have, in the first
place, the beautiful humming-birds, with toucans, jacamars, mot-
mots, todies, macaws, curassows, and tinamous. Specially note-
worthy, also, are the American ostrich, or rhea, the hoazin (Opis-
thocomus), the cariama, and the horned-senamer (Palamedea).

There are very many reptiles, and amongst them are both croco-
diles and alligators, but no gavials; an extensive family of Iguana-
like lizards, the ameiva and its allies, but no chameleon. There are
many snakes, including the boa-constrictor and rattle-snakes, but no
cobras, or true vipers. Batrachians are represented by Ophiomorpha
and many frogs and toads, including the celebrated Pipa of Sun-
nam. A few efts also exist in the mountains towards the north.
Amongst fishes may be mentioned the largest fresh-water fish in the
world (Sudis gigas), the electric eel, the Trygon family of rays, and
a Lepidosiren. The very numerous carp family, however, is here
unrepresented.

Thus this rich general zoological region agrees with the South
American feline region save that the latter extends further north,
while the former embraces the West Indian islands which are
excluded from the South American cat region. |

K K 2

lane ce Mr ne ee -

a

500 THE CAT. [cHAP, XIV

Finally, the AvusTRALIAN REGION is made up of Australia, with
Tasmania, New Guinea, Celebes, the Moluccas, and islands of the
Malay Archipelago up to and including Lumbok, and also of New
Zealand and the Polynesian Islands.

This great region is distinguished as the home of the marsupial
and monotr ematous mammals.

Only in the part which approaches the Indian region do we find
any ape or civet cat, with an ox (the anoa), hogs, deer and some
squirrels. Flying foxes, however, exist even in ‘Australia itself,
As to birds, there are no vultures or woodpeckers; or true finches
or pheasants, while we have, as absolutely peculiar to the region,
birds of paradise,* honeysuckers (Melephagide), lyre-birds, bower-
birds, cockatoos, many parrots, the brush-tongued lories, the mound-
making Megapodius, the emeu, the cassowary, and (in New Zealand)
the apteryx. It is also the head-quar ters of the group of kingfishers,
and it has many pigeons, including the crowned pigeon and the
hook-billed Didunculus. There are also large goatsuckers, and a
variety of weaver-birds and sun-birds. A multitude of snakes
exist, and very many poisonous ones, but no true vipers and no
rattle-snakes. As in India, we find gavials as well as crocodiles,
but no alligators. Only in the Malayan part of the region are
there any land tortoises. Absolutely peculiar reptilian forms are
the Pygopus, the frilled lizard, the Moloch ‘lizard, and above all (in
New Zealand) the lizard Sphenodon. + There are no Ophiomorpha,
and no efts, but there are very many frogs and toads. As to fresh-
water fishes, we have the very noteworthy Ceratodus (an ancient
triassic form here still surviving), while both the perch and carp
families are wanting.

New Zealand is very remarkable for the almost entire absence of
indigenous mammalian lfe—marsupial, no less than placental.
There, birds are almost the highest animals below man, and there,
until his arrival, they held undisputed sway as represented by the
huge creatures belonging to the genus Dinornis.

The Australian region then 1s not merely distinguished by an
absence of cats, but by the presence of an animal population which
could hardly have co-existed with them. In the West Indies and
Madagascar, cats may be absent merely through the accident of the
non-introduction into those parts of the earth’s surface of a large
number of mammalian forms of life, amongst which the cats were
included. Yet we do find there some mammals more or less allied
to cats; but their numbers are few, while the place of the Carnivora
is not taken by a great variety of other forms remote from them in
structure and affinity. In Australia, however, while the whole sub-
class to which the Fedide belong is conspicuous by its absence, it is
repiaced and represented by a multitude of creatures belonging to
another sub-class, 7.e., to the Didelphia. Thus the Australian

* New Guinea forms.
+ A last survivor of a group of forms long passed away.

a ee ee ee

CHAP. XIV. ] THE CAT'S HEXICOLOGY. 501

region may be considered as a sort of negative feline region, the
emphatically “catless ”’ portion of the globe.

§ 5. We must next consider the relations of cats to Time, and
first with respect to individual life. The cats of largest size appear
to live longest. The domestic cat lives ordinarily for about twelve
years, and eighteen years is the greatest age for which the Author
has obtained certain evidence. The lion is said however to live for
forty years, and the well-known lion named “Pompey,” which died
in the Tower of London in 1760, had lived there, it is asserted, for
no less than seventy years. This seems, however, to be a fable.
The Author has not been able to ascertain with certainty that the
lion lives beyond thirty years.

As to the period during which existing kinds of cats have lived
in times geologically recent, we must have recourse to history and to
deposits such as those amongst which have been found the prehistoric
remains of earlier racesof man. As to the existence of Fe/ide im more
ancient periods, and as tothe period when genera which are now
extinct flourished, evidence has to be sought for amongst the fossils
contained in the recks and deposits of different geological dates.

It has already been said that lions existed in South-eastern
Europe in the time of Xerxes. These may have been survivors of
the huge cat Felis spelea (the so-called cave lion). But whether
this was the case or not, it is certain that large extinct kinds,
together with the leopard and other smaller forms (including the
wild cat), ranged over Europe and England in prehistoric periods of
very different dates.

§ 6. Before passing in review those genera of cats which have
become extinct, it may be well to state briefly some elementary facts

of geology, an acquaintance with which is necessary for a correct

appreciation of the relation of the cat to past time.

The outer crust of the earth consists of more or less horizontal
layers of different materials deposited from salt or fresh water, and
known as sTRATA. In these are often contained evidences of past
animal life in the shape of (1) real bones, (2) pseudomorphs or
ageregations of mineral matter which have exactly taken the place
of real organic objects which have disappeared, (3) moulds external
or internal, or (4) casts of moulds of such objects—all these four
kinds of relics being what are called “ Fossits.”

The various “‘strata” were of course deposited at successive
times, and the time of the deposition of each is called its “ period,”
or “epoch.” But for subsequent disturbance, the most ancient
strata would always be, as they generally are, the deepest.

The uppermost and most recent accumulations of sands, clays,
and gravels form what are called the “recent deposits,” anc. these are
not counted as forming any part of the proper geological strata.

The strata beneath these are classified in three great groups,
belonging respectively to three great epochs.

The first or uppermost, and least ancient group, consists of strata
called the tertiary or cainozoic strata.

502 THE CAT. [CHAP, XIV,

The second, or next deeper and more ancient group, is formed
of strata, termed the secondary y or mesozoic strata.

The third, or deepest and most ancient group, comprises the

strata named the primary or palteozoie.
The PaLmozoic, or primary rocks, are made up of the following

groups of strata, or ‘‘ formations :” beginning with the oldest—1l,

the Laurentian ; 2, the Cambrian; 3, the Silurian; 4, the Devanen
and Old Red Sandstone ; ; 5, the Carboniferous (including the Coal
Measures), and 6, the Permian.

The Mexsozoic, or secondary rocks, are made up of: 7, the Triassic
formation or aia including the Wew Red Sandetant and the

Rheetic beds; 8, the Jurassic formation, including the Lias, the ~

Oolite, and the Purbeck beds, with the Galcaord slates of Bavaria,
and 9, the Cretaceous formation, including the Wealden, the
Greensand, and the Chalk.

The Carnozoic, or tertiary rocks, consist of the three forma-
tions known as: 10, the Eocene; 11, the Miocene, and 12, the
Pliocene, and these three last fuene fers are each subdivasible
into a lower, or more ancient, and an upper, or more recent,
portion. Deposits of the most recent pliocene times are distinguished
as Pleistocene.

The Eocene rocks in the form of gravels, sands, clays, and lime-
stones, are widely distributed, and vary considerably in thickness.
They form the areas which underlie both Paris and London. They
constitute deposits known in France as the ‘ Phosphorites de
Quercy” and the “Lignites of Soissonais,” * also the Wasatch
beds of Mexico, those of Fort Bridges in the south-west corner of
Wyoming territory, of Colorado, &e.

The Miocene beds are widely distributed in iurork and North
America, but are very slightly represented in England. They include
the deposits at White River, Dakota, and the white rivers of Nebraska
and Oregon in America, and the deposits of Sansan and Simorre
(Gers) in France.t The deposits of Pikermi, in Greece, were
thought to be certainly miocene, but it is doubtful now if they are
not really of somewhat later date.

The Pliocene formation is an extensive one in Europe, Asia, and
the United States, as e.g., between the Rocky Mountains and the
Missouri, and Loup River, Nebraska. It may (as just observed)
include the reputed miocene beds of Pikermi.

Posterior to the pleistocene deposits are those found in caves and
pe localities associated with the remains of early man, and known

“ Prehistoric.”

* 7. Such being the “ great groups,” the “ formations,” and the
several “strata” in which fossils are found, those of the cAT FAMILY
occur as follows:

The genus Felis is found in Greece and India, in strata of the

* The ‘‘Phosphorites” are upper | cene; the White Rivers of Nebraska and
eocene, the ‘‘ Lignites” are Jowereocene. | Oregon, and the John Day region ot
+ The Sansan beds are middle mio- ' Oregon, are lower miocene.

CHAP. XIV. ] THE CATS HEXICULOGY. 503.

newer miocene or oldest pliocene age. A cat, the Felis media of
Larlet, has been found in the middle miocene in France. F.

_Christolii (a cat of the size of the serval) occurs in the lower pliocene

of France. In pleistocene times, tiger-like cats, with the leopard,
lynx, and wild cat, were found in England.
_ Felis spelea became extinct north of the Alps at the close of the
pleistocene age; but, as has been said, the well-known “lions”
which existed in Macedonia in the time of Xerxes may have been
surviving examples of that species.

Macherodus is preserved in pliocene and miocene deposits of
Kurope, India, and America, both North and South. It survived in

* England down to late pleistocene times.*

Hoplophoneus is from the White River, Nebraska, or lower
miocene.

Pseudelurus has been found in the Phosphorites de Quercy, Loup
River, Nebraska, and Sanson (Gers). It is therefore eocene and
miocene and pliocene.

Nimracus is a form from the White River, Oregon, and, there-

- fore, of lower miocene times.

Dinictis is eocene and miocene, occurring as it does in the Phos-
phorites de Quercy and the White Rivers of Colorado, Nebraska, and
Oregon.

Archelurus is from the lower miocene beds of the John Day
region of Oregon.

Pogonodon is from the same region as Archelurus.

Eusmilus is eocene, from the Phosphorites de Quercy, and

Ailurodon is from the pliocene of Loup River, Nebraska.

The forms which are oldest therefore, are Pseudelurus, Dinictis,
and Husmilus. That is to say, the first in time for which we have
any evidence are two genera which, in very different degrees, differ
from the cat type and approach less specialized forms, and also one
genus which is most extremely specialized.

Next come Pogonodon, Archelurus, Nimravus, Hoplophoneus,

Macherodus and Felis; that is to say, the most generalized forms

of all the Felide, together with extremely specialized forms.

Nevertheless it is a fact that the genera which most approach
ordinary non-feline carnivora—the genera namely Archelurus and
Dinictis—are from the eocene or older miocene, and none of the most
generalized forms have as yet been found in pliocene strata.

No feline remains have been discovered in any deposit whatever
which is older than the eocene, 7.e., there are none in any mesozoic
or secondary strata.

§ 8. But very few mammalian remains of any kind have as yet
been found in secondary rocks, though of course multitudes of
mammals must have existed before the eocene strata were deposited.
The remains of beasts first make their appearance in the upper

* See a paper by Professor W. Boyd | Journal of the Geological Society, August,
Dawkins on Tertiary Mammals, Quarterly | 1880.

504 THE. CAT. [ CHAP, xax,
part of the trias and also in the oolite, including the Purbeck beds.
Such remains have been found in both Europe and North America,
and consist of the genera Wicrolestes and Dromatherium. Microlestes.
is a small insect-eating beast,* of which a few teeth have been dis-
covered. Dromatherium + is a small American mammal, the mandible

of which bore on each side three incisors separated by short intervals,
a canine, and ten teeth in a continuous series of premolars and
molars.

Other mesozoic forms are Amphitherium, Amphilestes, Phascolo-
therium, and Stereognathus.

| Amphitherium ¢ is a genus founded on a lower jaw, with three
incisors and a canine on each side, but with a series of twelve pre-
molars and molars. The angle of the mandible is not inflected in
Amphitherium. ; ae .

Amphilestes § is a form similar to the last, but with teeth more
bristling with pointed tubercles, suited for crushing the bodies of
insects.

Phascolotherium|| had three rather separated incisors on each side of
its mandible, a canine, and a series of only seven teeth representing
the premolars and molars. The angle of the mandible was inflected.

Stereognathus J is an extinct form known by a portion of a
mandible (from the Stonesfield slate) three quarters of an inch long,
with three teeth quadrate in form, each with three pairs of cusps,
and not distinctly resembling those of any existing group of animals.
These forms (except the last mentioned) have been generally
presumed to be marsupial, from their resemblance to certain
modern marsupials, such, ¢.g., as Myrmecobius, a small Australian
opossum, with a series of nine molars, a canine, and three rather
separated incisors on each side of the mandible. Some of these
fossil genera also present certain resemblances in the form of the
molar teeth, or in the position of the dental foramen, to American
opossums (the genus Didelphys) or to kangaroo-rats (Hypsiprymnus).
‘The above are the yet known secondary mammalian forms. |

When we enter upon eocene strata we come at once upon a mulfi-
tude of mammalian species now passed away, some of which it will be
well here briefly to pass in review for reasons which will appear in
the next chapter. Amongst eocene mammalia a group of fossils may —
first be mentioned which have been associated together by Professor
Cope under the term Creodonta.** Some of these creatures had

* See Owen’s Paleontology, p. 301.

+ Lc... p. 02:

+ See Owen’s British Fossil Mammals,
‘p. 29.
8 § Owen’s Paleontology, p. 303, and
Brit. Foss. Mam. p. 58 (Amphitheriwm
Broderipii).

|| Owen’s Paleontology, p. 304, and
Broderip, Zoological Journal, vol. iii.,
p. 408, plate 40.

{| Owen’s Paleontology, p. 308.

** See his paper on Creodonta, read
before the American Philosophical Society
in July, 1880. See also his paper on the
Flat-clawed Carnivora of the Kocene of
Wyoming, in the Proceedings of the
American Philosophical Society, vol. xiii.,
No. 90, 1873. See also Professor Flower’s
Extinct Animals of Norta America, a
lecture delivered at the Royal Institution
on March 10th, 1876.

CHAP. XIV. ] THE CATS HEXICOLOGY. 505

claws which, unlike those of cats, dogs, and other existing carnivora,
were nearly flat, straight and blunt. In none did the carpus
contain a scapholunar bone, but it had two separate bones in its
place. The jaws of the Creodonta were long and rather slender,
containing a number of molars, all more or less alike, and (in most
genera) all sectorial in form, instead of being differentiated into
a few simple premolars and one large sectorial tooth, with one or
two tubercular teeth behind it—as are the teeth of almost. all
existing carnivora. The astragalus, moreover, instead of pre-
senting that peculiar pulley-like shape which we have seen in the
cat, presents in almost all these creatures a plain flat surface as in
the existing Insectivora, Rodentia, Proboscidea, and Apes.

One of these eocene forms has been called Proviverra, by Riitimeyer,

and Gandry* has described a similar form (from the Phosphorites de
Quercy), which, in many respects, reminds us of Marsupials. The
avgle of the mandible, however, is not inflected, and the bony palate
is well ossified, and there are only six incisors im the upper jaw.
The teeth behind the canines (of which there are six or seven in
each jaw) are all sectorial, except the last upper one, which is. placed
transversely. The cerebrum is so little developed that not only the
cerebellum but even the corpora quadrigemina are uncovered by it,
while the olfactory lobes are largely developed.

Pterodon + is a form very similar to the last, with several sectorial
teeth in each jaw. The structure of the feet of this animal is as
yet unknown.

Oryenat is an American mammal, some individuals of which
were as large as the jaguar. It is closely related to the European
form Pterodon ; but there are but two superior true molars, and the .
last of these is driven in transversely. The first true upper molar
is the sectorial tooth, instead of the sectorial being the last premo-
lar, as in existing Carnivora. The two last inferior molars are
described as ‘‘ tubercular-sectorial.”’

Stypolophus is another American mammal, said by Cope § to
differ from Oxyena only im certain details of tooth structure, namely,
in having the three last lower molars ‘ tuberenlar-sectorial.”’

Mesonyz || is very similar to the preceding, and also American. It
has seven inferior teeth behind the canines, but “the trochlear face
of the astragalus is completely grooved above as in the true Car-
nivora, and its distal end presents two facets, one for the cuboid and
the other for the navicular bones.”

* See A. Gaudry’s Enchainements du | before the American Philosophical Society
Monde Animal, p. 20, figs. ‘13-15. | in July, 1880, p. 2.
This genus is the Cynohyznodon of § Cope, J. ¢., p. 3.
Filhol. | Cope, 7. c., p. 2; and see also his
7 Gaudry, 7. c, pp. 15-24, figs. 5 | paper on the Flat-clawed Carnivora of
and 6; see also Gervais, Paléontologie | the Eocene of Wyoming, in Pro. of the
Frangaise, p. 236, plates 11 and 26, and | Amer. Phil. Soc., vol. xiii., No. 90,
Filhol, Ann. des Se. Geol., vol. vii, | 1873. Professor Cope believes that
p. 218, figs. 184-188. Syneplotherium is really a species of
{ See Cope’s paper on Creodonta, read | Mesonyx. .

506 THE CAT.

In Miacis* on the other hand, the astragalus is flat, but in the
lower jaw “‘ we have a near approach to the dentition of the dogs.”

Didymictis,t from the American lower eocene, is closely allied to
Miacis, differing only in having one less inferior tubercular molar.

Paleonictis + is a genus which is thought to resemble the Viverrine
Carnivora in its teeth, save that the second lower true molar is
rather sectorial unlike that of existing carnivorous mammals.

Amblyctonus § seems only to differ from the last in that its fourth

inferior premolar supports tubercles instead of a cutting edge.

Patriofelis || is a genus founded on some fragments of a jaw ob-
tained by Professor Hayden from near Fire Bridge, Wyoming. It
was larger than the panther, the lower jaw being six inches long.
It has similar characters to those of Mesonyx, save that there are
only five lower molars instead of seven.

HyenodonG is a well-known European form, but is found in
America also. It has also sectorial molars in large number, but its
brain ** was formed on the same type as that of the existing carni-
vora. Hyenodon has a scapho-lunar bone.

Arctocyon, the oldest mammal yet discovered posterior to the
mesozoic epoch, is another long and well-known European fossil +t
animal of the lower eocene. It is almost as large as a wolf, with a
long tail and a much curved humerus with a strong deltoid ridge.
The skull is very narrow between the middle of the zygomatic
arches, and has large palatine foramina. The brain had large
olfactory lobes and a small cerebrum which left the cerebellum and
probably the corpora quadrigemina uncovered and was almost un-
convoluted. ‘There were seven upper molars. The first of these
had one root, the second and third two roots, then came a triangular
tooth (slightly sectorial in character), followed by three tubercular
molars, the last but one being the largest. The teeth were gene-
rally tubereular. The ankle joint is unknown.

Cynodon tt is an upper eocene form, considered by M. Gaudry as
intermediate between the dogs and civets, some species being more
like one and others more lke the other of these two types. Like

Philadel. vii., p. 39, plate) 25ssana

* Cope’s paper on Creodonta, pp. 3
De Blainville’s Ostéog. (Canis), p, 17;

and 58.

(CHAP. xIV. —

+ Cope, J. ¢., p. 3.

+ Cope, 7. c., pp. 3 and 6. See also
Gaudry, ST Game | Main 0 Fee ea y |
Gervais, Paléontol. Francaise, p. 225,
plate 25, figs. 11, 12.

§ Cope, U. ¢., p. 3.

|| See United ae Geological Survey
of Territories, vol. i., p. 114, plate 7,

Hg: 20's and Peon ” Acad. "Nat. Se.
Philadel., March, 1870, p. 11, plate 2,
fig. 10.

"T] See Gaudry, 7. c., p. 14, figs. 3 and
4; also Gervais, Pal. Franc., p. 282,
plate 24; Filhol, Ann. des ‘Sc. Geol.,
vol. 7, p. 162 ; and Leidy’s Mammals of
Dakota and Nebraska, Journal Acad.

and De Laizer and De Parien, Ann.
des Sc. Nat., 2nd series, vol. xi., 1832.

** Nouvelles Ann. du Muséum,
1870, plate 6, fig. 7.

+t De Blainville (Subursus), p. 73,
plate 13; Gervais, Paléontol. Frang. p.
220; and Nouvelles Ann. du Mus,
vol. vi, p. 147, plate 6, fig. 4 (brain) ;
Gaudry, J. c., pp. 22-24, fig. 14.

tt See Gervais, Paléonto]. Fran., p.
218, plate 15; and Aymard, Ann. de
la Soc. Acad. du Puy, vol. xv., p. 92,
1851; also Gaudry, J. ¢c., p. 215, figs.
282 and 283. M. Filhol has shown the
great variability of Cynodon.

ea Na ae) i eS

CHAP. XIv.] THE CAT'S HEXICOLOGY. 507

Arctocyon it has seven molar teeth in the upper jaw, the three
hindmost being tubercular. The tooth next in front of these three
is, however, of a more sectorial character than in the corresponding
tooth of Arctocyon.

Cynodictis * is another upper eocene carnivore which closely
resembles Cynodon, but there are only two tubercular teeth behind
the upper sectorial.

Amongst the forms of life of the uppermost eocene and lower
miocene may be mentioned Amphicyon,+ which is another well-
known fossil form allied to the dogs, from which it differs in that its
molars are less sectorial and more tubercular, and that it has a
third upper true molar. Its limbs are more bear-like than are
those of the dogs, and it was also plantigrade.

Hyenarctos ¢ is a widely distributed form from the upper mio-
cene, which has marked affinities with that just noticed ;* but its

tubercular teeth are still larger, and specimens of most recent date

(from the pliocene beds of Montpellier) have the tubercular teeth
more quadrangular in form and therefore still further removed from
the sectorial type, approaching more and more to the structure we
now find in the bears.

Ictitherium § is a genus of which various species have been
described; some as large as a leopard. They are found in the
upper miocene or pliocene of Europe. It is imtermediate in its
dental structure between the civets and the hyenas, in that it has

_asecond upper tubercular molar, This tooth 1s different in size in

different species of the genus, being very small in J. hipparionum.

Lutrictis || is a miocene form from Auvergne which belongs to the
family of Mustelide, but has a minute second upper molar.
M. Gaudry considers it allied to the otter. |

Galecynus J is a miocene and pliocene form which 1s very fox-like,
but has the first premolar smaller, and the third and fourth larger,
and all the teeth are more close-set and occupy a smaller space than
in the fox. The bones of the feet also are more robust.

As to non-carnivorous mammals, it is evident that bats and
opossums (Didelphys), tapirs and rodents existed in Europe in
eocene times, while with the miocene period, apes, rhinoceroses,
giraffes, and hippopotami co-existed in our continent. Many
other forms might also be enumerated, but the above lst may
be sufficient for our present purpose, as affording examples of eocene
and miocene mammals which present more or less interesting,

* Gervais, Paléontol. Frang., p. 216; + Gervais, Paléon. Frang., p. 207,
Filhol’s Ann. des Se. Geol., 1876, vol. | plate 81; Gaudry, J. ¢, pp. 212, 213,
vii., p. 66. figs. 278 and 279.

7 Gervais, Pal. Frang., p. 214, plate § Gaudry, J. ¢c., pp. 208, 216, and 217,
28 ; Filhol, Ann. des Se. Geol., vol. vii., | and figs. 274, 284, and 286. See also
p- 55, figs. 23-26, and 41-43; Leddy, | his Fossils of Pikerni, p. 52, plates 7, 12.
Mammals of Nebraska and Dakota, || Gaudry, 7. c., p. 219, fig. 290.

Jour. of Acad. of Nat. Se. Philadel. vii., 7 Owen, Quarterly Journal of Geol.
p. 31, plates 1 and 5; Gaudry, J. c., pp. | Sos., vol. iii., 1847, p. 55.

_ 24 and 212, fig. 277.

a ce

508 PEE OAT: | [cHap, XIV. q
more or less significant structural relations with the anatomy of
the cat—mammals to which reference will have to be made in the
following chapter.

§ 9. The next and last point to be considered in studying the
cat’s hexicology, concerns its RELATIONS WITH OTHER LIVING BEINGS.

Living beings may affect each other’s existence in a variety of
ways, as food, as rivals, as indirect friends, or as direct enemies.

Now, in the first place, the Jelide, as essentially carnivorous
animals, can only live where they can find such other animals as
may be necessary for their food ; and, accordingly, it is where land
animals are most abundant, that the most numerous and largest —
kinds of the cat family are found. Certain kinds of cats also are,
as we have seen, of arboreal habits; and the presence or absence of —
forests will very importantly affect the existence here or there of
such forms. a

The markings of cats have been supposed to be useful to them in
various ways in their relations with other animals. The vertical
stripes of the tiger resemble the vertical shadows of the grasses of
the jungle amongst which it lurks, and may so aid its concealment
and allow its prey to approach it unsuspectingly and fatally. The
scattered spots of the leopard agree with the scattered spots of
shadow amongst the foliage of the trees on the boughs of which it
hes in wait. Similarly the hue of the lion has been thought to be
useful to it in sandy plais. All this is no doubt true, but a multi-
tude of instances are to be found in nature in which shapes, colours,
and markings are most noticeable, but yet do not answer any purpose
of the kind above referred to, and therefore to regard such relations
as the main causes by which these markings have been brought
about would be to rest in an explanation fundamentally inadequate.

Animals stand to each other in the relation of rivalry where they
each consume the same kind of food and thus tend to starve each
other. Such a rivalry must evidently exist between different kinds -
of cats, and so prevent the coexistence of many kinds or many indi-
viduals of the same kind in the same locality.

Living creatures may unintentionally act a friendly part to one
another; inasmuch as animals of one kind may destroy creatures
which are inimical to the existence of another kind, and thus every
animal which destroys creatures which prey upon feline animals of
course benefits the latter. Again, whatever creature tends to render
abundant the food of another creature is of course the latter’s bene-
factor. Thus it has been observed that the presence of a certain
kind of clover is beneficial to cats; inasmuch as it is useful to a
particular species of humble bee, the nests of which favour the
existence of mice, which again are the food of cats. Did we know
the analogous inter-relations which exist between the living creatures ~
of tropical forests, we should doubtless come upon many curious cross —
relations and interdependencies of a similar kind, affecting their
feline population.

But various kinds of cats seem to have other cats for their direct

_ oHAP. xiv.) THE CAS HEXICOLOGY. 509

enemies; for we have seen that the tiger will even carry off and
devour a wounded individual of its own species.

The direct enemies of the largest and most powerful cats must be
few; since the great beasts which may successfully contend with
them—elephants, rhinoceroses, &c.—being herbivorous creatures,
are not impelled by hunger to pursue and attack them. The smaller
cats no doubt occasionally fall a prey to other carnivora, but who-
ever has seen a dog attack a cat, and has noted the combined ferocity
and dexterity which the cat can exhibit with its very efficiently armed
paws, may well doubt whether wild-cats of any kind will often be
successfully attacked by any creatures not overwhelmingly superior
to them in size and strength.

§ 10. Against other enemies, however, of avery different kind, even
the largest cats have no power ‘ofresistance. Such enemies are their
internal and external parasites. These chiefly belong to the sub-
kingdom Vermes. ‘The first group is that of the thread-worms
(Nematordea). Of these there are several species which find a home
in the body of the cat. They are* Ascaris mystax, Trichina spiralis,
Trichosoma cati, Oxyuris compar, Strongylus tubeformis, and Olulanus
tricuspis. The second group is that of the flukes (Zrematoda), of which
there are not less than three kinds, namely, Distoma lanceolatum, Am-
phistoma truncatum, and Hemistoma cordatum. The third group,
that of the tape-worms (Zeniada), is represented by at least eight
species as follows:—TZenia elliptica, Tenia crassicollis, Tenia
semiteres (Baird), Tena litterata (Tenia canis-lagopodis), Tenia
lineata, Bothriocephalus felis, and Bothriocephalus decipiens. The
Cysticercus cellulose, or larva of Tenia solium, has been obtained
from beneath the scapula, and Engelmayer found a Canurus in a
cat’s liver.

Dr Spencer Cobbold has observed,+ “‘ Every owner of cats must
have, from time to time, noticed the frequent occurrence of sickness
- amongst these animals; such fits of vomiting usually terminating in

the expulsion of worms from the mouth. The internal parasites
causing these attacks are small nematodes (Ascaris m ystax) occupy-
ing the stomach; the females being nearly twice as long as the
males, and sometimes measuring as much as four inches. Strong gylus
tubeformis is occasionally found in the upper intestine, and Trichina
___ spiralis has been reared in the cat by experiment... .. The most
important of all the feline nematodes is a little worm, Olulanus
tricuspis. Whilst the full-grown Olu/anus only measures about 54
_ of an inch, its embryos are, for so small a creature, of almost gigantic
size. The adult worm resides in the lining membrane of the stomach.
The young of this parasite, like young Trichine, areaptto migrate within ©
the body of the feline host. They thus become encysted within the
lungs and liver; but not in any other of the visceral organs. I have

ae” ee ae Cee ee el =
- = y 4 re - r

ee ee ee ee ee ae eo. ae ee on! ee, a eee - a?) ae a

* For the list here given I am indebted + See his work on The Internal Parasites
to the kindness of my friend Dr.T. Spencer | of our Domesticated Animals, p. 124; and
__ Cobbold, F.R.S. his more recent work on Par asites, p- "308.

510 THE CAT,

[cHAP, XIV.

seen tens,of thousands of them occupying the lungs; the infested
animal perishing in consequence of the inflammatory action set up
by their presence.” |

« A certain number of the embryos of Olulanus escape by the bowel
of the host. These when swallowed by mice become encysted within
the little rodents’ muscles, very much after the fashion of Trichine.
So that one may say the mice become olulanised in the same way
that we say people or animals become trichinised. All this has been
experimentally proved by Leuckart, who fed a cat with olulanised
mouse-flesh, and afterwards found the escaped young in the cat’s
alimentary canal. As, however, these encapsuled Olu/ani from the
mouse had not become sufficiently advanced in their larval * organi-.
sation, Leuckart did not succeed in rearing the sexually mature
parasite in the feline stomach. But there could be no doubt as to the
ultimate destiny of the encapsuled young. .... Tenia crassicollis,
which is common to both the tame and wild animal, is obtained by
the cat from eating the livers of rats and mice, in which organ the
larvee of the parasite reside. Tenia lineata is found only in the wild
cat. Bothriocephalus decipiens is extremely rare, and only known in
the house cat. The most common of all the species is Zwnia
elliptica.” Tenia litterata exists in Iceland, but has also been found
to infest the cheetah. It must therefore have a wide distribution.

One of the most remarkable instances of the destruction of cats
by internal parasites is that recorded by Dr. Romano, of Gemona.
The animals perished from colic, diarrhcea, epileptiform convulsions,
wasting, and complete prostration. All these symptoms resulted
from tapeworms (Zeenia crassicollis) within the stomach. The out-
break occurred at Osoppo, where the fortress was over-run by rats.
The vermin were combated by means of the cats, and thus the most
successful felines became the earliest victims. Those which killed the
rats and ate their livers swallowed the larve of the Tenia, which
latter, en revanche, brought about the destruction of their feline hosts.+

Another ,internal parasite is the worm-like animal Pentastoma
denticulatum, which is a very aberrant member of the class
Arachnida.

As to the cat’s external parasites, they belong to two orders of
the class Insecta (the order Aphamptera, which contains the fleas,
and the order Aptera, which is the order to which lice belong),
and to the class Arachnida. )

The cat’s flea,t Pudlex cati, is very like the flea of the dog, but is
one-fourth smaller.

The louse-like animal of the

* The tape-worms have two stages of
existence, corresponding with the grub
(or larval) condition, and the perfect (or
imago) state of the beetle or butterfly.

+ See Cobbold’s account (Parasites,
Z. c.), abridged from Romano’s report in
Giornale di med. vet. pratica for August,
1877.

cat does not belong to the same

+ See a paper by Dr. Alexander La-
boulbene, on Les Metamorphoses de la
Puce du Chat, in the Annales de la Soe.
Entomologique de France, 5th series,
vol. ii., 1872, p. 267, plate: isi salem
P. Megnin’s Parasites, Masson, Paris,
1880, 63.

t

CHAP, XIV. ] THE CAT'S HEXICOLOGY. B11
family of the order as that which contains the lice of men,and apes.
It belongs to the family which contains the bird-lice. This parasite
of the cat is called Trichodectes subrostratus.* Its presence appears —
to cause no evil or inconvenience to its host.

The arachnidan external parasite is a sort of itch insect, named
Sarcoptes cati.t It is so small as hardly to be visible to the naked
eye, but soon accumulates in vast numbers (to the cat’s extreme
annoyance), especially on the head, ears, eyelids, and face, where it
causes swellings as well as baldness, beginning on the back of the
neck and head. The paws, also, are apt to be affected, as naturally
ensues from the infected animal’s vain attempts to remove the
cause of distress. Catarrh, diarrhea, distemper, consumption, and
insanity, are amongst the disorders from which cats are more or
less apt to suffer. i

* See Megnin’s Parasites, p- 81; also | Britannie, 1842, p. 189.
E. Piaget’s fine work, Les Pédiculines, t See P. Megnin’s Parasites, pp.
1880, p. 389, plate 31, ‘fig, 9; and Henry | 174 and 409.
Denny’s Monographia Anoplororum

CHAPTER XV.

THE PEDIGREE AND ORIGIN OF THE CAT.

§ 1. In the preceding chapters, the creature which has been
selected as a type of mammalian back-boned animals, has been
represented from various points of view. Its anatomy, physiology,

psychology, taxonomy, and hexicology, have been successively

treated of and the processes of individual development—the series of
changes gone through by each individual of the cat species in reach-
ing maturity—have been noticed. It only now remains to study
the development of the species—that is to say, the “ pedigree and
origin,” both of the cat considered as a species, and of the whole
family of Fehde.

To trace, as far as may be, the series of forms through which the
existing group of cats may, with most reason, be believed to be
descended, is, in this sense, to trace the cat’s PEDIGREE. ‘To investi-
gate the probable causes which have evolved such forms and
governed such process of development, is to investigate the cat’s
ORIGIN. .

§ 2. That the various kinds of cats, and the whole cat group,
have been evolved through the orderly operation of powers divinely
implanted in the material creation, is a statement the truth of which
can now, it seems, be hardly denied by any consistent persons who
are not prepared to maintain that with the birth of every very ex-
ceptionally formed kitten a direct intervention of the First Cause

takes place—an intervention such as does not otherwise occur in the _

orderly sequence of purely natural phenomena.

§ 3. In order to investigate the question of the cat’s pedigree, or
phylogeny, its relation to other animals must be carefully borne im
mind.

In the thirteenth chapter it was pointed out that the cats are most
nearly related to the Foussa (Cryptoprocta), and in a less degree to
the other members of the family Viverride. That they have a more
general affinity to the whole sub-order. 4Juroidea, and a still more

general one to the whole order Carnivora, and ultimately to —

mammals and to all backboned animals—beyond which they can be
said to have no special affinities at all
The ancestors then of the cat family must be sca for amongst

@ cade .

a
.

cHaP. xv.}] THE PEDIGREE AND ORIGIN OF THE CAT. 513

extinct forms of carnivora nearly related to the cats and civets; and

<a

the ancestors of such forms, again, must be sought amongst car-
nivorous mammals of more and more generalized structure till we
come to creatures from which all mammals may be supposed to have
descended. What animals were the progenitors of all mammals, is
as yet a matter of pure speculation, and no positive judgment can be
formed concerning it by any prudent naturalist. Certain proba-
bilities, however, are evident as to this and cognate questions, but
before adverting to these probabilities, it will be well to recall to
mind some of those existing and extinct animals to which reference
has already been made.

The most aberrant and generalised of all existing’ cats is the
cheetah (Cynelurus). But though this animal approaches the other
carnivora in that its claws are less retractile than those of other cats,
yet its tooth structure—its upper sectorial *—is exceptional in a way
peculiarly its own. Neither Cynelurus, therefore, nor its extinct
ally lurodon, seems to help us towards tracing the cat’s pedigree.

The flat-headed cat (Ff planic eps), as has been shown (Fig. 177),
approximates somewhat towards viverrine forms in the large size of
its two-rooted first upper molar. But the extinct genera Pseude/lurus,
Dinictis, and above all, Arche lurus, lead us decidedly towards more
generalized forms, and render the descent of both Cryptoprocta and
Felis from some commen Viverrine root a matter highly probable.

It must be borne in mind, however, that although these miocene
and eocene cats were thus generalized in structure, yet a most ex-
tremely specialized form of cat, e.g., Eusmilus, existed at the same
early perica. But avery generalized kind of dog, Otocyon (which has
four premolars and three molars on either side of each jaw), exists
to-day side by side with dogs in which the number of teeth is much
less, and which are more specialized. Yet naturalists do not on that
account doubt but that Otocyon is a survivor of an earlier condition
once common to the whole group of Cynoidea. Similarly the co-
existence of Husmilus with Dinictis or Archelurus, does not detract
from the probability that in the last two genera we have examples of
the sort of animals whence all cats come.

Zoological and paleontological evidence, then, points to a viverrie
origin of cats. ‘They seem either to be the very specialised descend-
ants of ancient viverrine animals, or else both cats and viverrines are
the diverging descendants of an ancient, more generalized form
which existed in times anterior to the eocene, of which more gene-
ralized form no relics have as yet been discovered.

§ 4. But the viverrine animals themselves, whence came they ?
In the existing creation, they are distinguished from the hyzenas by
having two upper tubercular molars. But Professor Gaudry has
discovered a form (named by him Ictitherium hipparionum, which,
as we have seen,f 1s intermediate between the civets and hyeenas,

* See ante, p. 428. T See ante, p. 507.
LB

514 THE CAT. [cap xv,

and which, though it has two upper tubercular molars, has the
hinder one quite rudimentary.*

The civets, again, differ from the hyenas, in having a lower
tubercular molar. But the same accomplished paleontologist has
discovered another fossil form, Hyenictis,t which is hyeena-like, but
yet has a rudimentary lower tubercular molar tooth. '

But can we get any probable suggestion as to the origin of the
cat’s sub-order, the Ailuroidea ? To be able at all to answer this
question, we must glance at fossil forms related to the other car-
nivorous sub-orders. As regards the dogs (Cynoidea), the existing
Otocyon, and the fossil genus Galecynus,t lead down to forms of more

general affinities which may have been dog ancestors. One such

is Cynodictis § (of the upper eocene), and which leads on to Cynodon,||

which is a still more generalized form, showing, in M. Gaudry’s

opinion, certain affinities to the civets.

Amongst the Arctoidea, the weasel family (Mustelide) is—inasmuch
as it is an arctoid. family—distinguished by a variety of characters 4
from the Viverride. Amongst the characters by which it differs is
that of the absence of a second upper tubercular molar. In Lutyictis,**
however, we have a musteline form in which the second upper
tubercular molar is present, though very small.t+ In Proclurus,tt
also, we have a fossil with seeming musteline and viverrine affinities,
yet with teeth which approximate to those of the cats. The true
bears (Ursidw) were preceded by mammals such as the miocene
Hyenarctos,§§ which, with the help of Amphicyon,|||| apparently
connects them with the dogs.

The three sub-orders of carnivora being thus brought near to-
gether in the past, to what other group can they—i.e., can the
whole order Carnivora—be affiliated? What may probably have
been the cat’s ancestors in a yet more remote degree than the un-
known common stock whence the three existing suborders gradually
diverged ? |

§ 5. We have seen | that the oldest tertiary mammal Aretocyon,

has characters which give it some claim to be nearly allied to the
progenitor of all true carnivora. But besides such characters, we
find in it conspicuous defects of palatal ossification, and a low form
cf brain, which characters would seem to make it impossible that its
claim to be an ancestor of the carnivora should be established.
Moreover, we have seen that there are a number of eocene fossils
such as Pterodon, Proviverra, Hyenodon, Palwonyctis, &c.,*** which
agree in having (amongst other common characters) teeth which are
not differentiated into premolars and an upper and lower sectorial

* See Les Enchainements, p. 217, ++ See Les Enchainements, p. 219,
fig. 286. fig. 290.
i i. ¢., Pp. Aide Me. Zoo. {tt See ante, p. 435. .

' £ See ante, p. 507. §§ See ante, p. 507, and Les Enchaine-
§ See ante, p. 50. ments, pp. 212 and 213, figs. 278 and 279.
| See Les Enchainements, p. 215, ||| See ante, p. 507, and Les Enchaine-

figs. 282 and 283. ments, p. 212, fig. 277.
4] Ante, p. 475. “19 See ante, p. 506.

** See ante, p. 507. *** See ante, p. 505.

cHap. xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 515

tooth followed by one or more tubercular molars, but which, instead
of this, had a series of sectorial teeth.

§ 6 It has been contended by several eminent paleontologists
that these creatures were marsupial, and that all the first mammals
were didelphous mammals—an opinion supported by the before
explained * resemblance of the mesozoic mammalian fossils to the
existing marsupial—Wyrmecobius.

If this view is correct, the pedigree of the cat descends through
marsupial ancestors to the most generalized placental (or monodel-
phous) carnivora. It is here contended, however, that such was
not the case, but, on the contrary, that it is probable that the cat
never had a marsupial (or didelphous) ancestor at all, but that its
progenitors (anterior to carnivores) were long-lost beasts of the
Order Insectivora. It appears indeed to be probable that Insectivores
and not-Marsupials were the parent forms of the great Mammalian
stock—z.2., that the hedgehog and not the opossum is the existing
representative of the root-form of that class to which we (as
animals) and the cat both -belong.

Those characters in which Pterodon, Proviverra, Hyenodon, Pale-
onictis, &c., have been thought to resemble marsupials, tell equally
in favour of their affinity to the Insectivora. Such are the small
brain, with uncovered corpora quadrigemina and large olfactory lobes
—characters which has been shown to have existed in Proviverrat
and Arctocyon.t Such again are the numerous sectorial teeth of
Hyenodon, Pterodon, Paleonictis, Proviverra and others, and the
defective palatal ossification of Arctocyon. Moreover these forms
do not possess more than six incisors above and below, while the
angle of the mandible is not inflected. If the angle were inflected,
however, sach a character would not be decisive in favour of their
marsupial affinities, as the Taurec (Centetes), though a placental
mammal—a member, moreover, of the order Insectivora—has
its mandibular angle inflected. Hycenodon and Pterodon have also
been shown § to have possessed a complete milk dentition, a character
which separates them markedly from all existing marsupials.

To this reasoning it may be replied, that true marsupials existed
in Europe contemporaneously with the beasts the nature of which
is in dispute, and that the earliest known mammalian remains
(those of the secondary rocks) resemble existing marsupials. These
assertions are true, but in the first place the existence of marsupials,
with such creatures as Proviverra, only proves that marsupial life
was then already developed as well as placental life, a fact
of which we have abundant evidence.|| Such a fact, however,
in no way shows that the latter was derived from the former.
Then as to the mesozoic mammals, the forms now living which they
resemble, 7.c., I/yrmecobius, is just one of those marsupials to which

* See ante, p. 504. 6, fig. 4.
+ See Les Enchainements, p. 21, fig. § By M. Filhol, see Ann. des Se.
15. Géologiques, vol. vii., p. 169, plate 22,
t See P. Gervais, in Nouv. Archiv. | fig. 79, and plate 31, fig. 148, 1876.
du Muséum, vol. vi., 1870, p. 147, plate || See ante, p. 507.
LL2

516 THE CAT. [cHAP. xv.

the specially marsupial character, “the pouch,” is wanting. The
same is the case in the allied genus Phascogaile, while in most of the
small American opossums (Didelphys), the pouch is not developed.
The character is still a very variable one in many forms of the order—
as if it had not become even now a well-established character. In-
the predatory opessum—the so-called Tasmanian wolf (Thylacinus),
‘the marsupial structure, if shown at all, is represented by a pair
of shallow, semi-lunar fosse, with their concave outlets opposite
each other as in Hehidna.”’ * | sat
It is the very highly specialized Australian kangaroos and pha-
langers—forms which may be relatively modern developments—
which have the pouch most completely tormed and which may be
considered the typical representatives of marsupial life. a,
Moreover the secondary fossils, Amphithorium, Amphilestes, Dro-
matherium and Phascolotherium, had, as we have seen,+ but six
incisors in the mandible, while only in Phascolotherium was the
mandibular angle inflected. All then that the yet discovered meso-
zoic fossils can. be held to demonstrate is, that there existed at the
time of their entombment, forms having both placental and didel-
hous affinities and which may have been some of the as yet
undifferentiated ancestors whence those two now divergent sub-
classes of mammals have descended. |
And it is far from impossible that some existing marsupials may have
come from a different root from that which gave rise to others. Forms
may have grown alike from different origins, as few things are more
certain in the matter of development, than that similar structures
often arise independently, and causes which would induce marsupial
modifications in the descendants of one root-form might well also
induce them in those of another root-form. The singular difference
in the structure of the hind-paw in the more typical marsupials—
the kangaroos and phalangers—from that which is found in Didelphys,
Dasyurus, Phascogaie and Myrmecobius, seem to poit to a twofold
origin of the modern order Marsupialia. The hypothesis then
which represents the most ancient mammals to have been allied to
the Insectivora, is one which appears to me best to accord with all
the facts yet known. Thus we may account for the low brain
structure and defective palate of Arctocyon; for the form of the
molars of Proviverra and its allies; for the form of the astragalus
noted by Professor Cope; for the number of the inferior incisors;
for the rare inflection of the mandibular angle and for the existence
of a complete milk dentition. | a
From this Insectivorous root then, the Marsupials, as we at
present know them, must have diverged as a relatively unimportant
branch, while the main stem of the mammalian tree was continued
on by the successively arising placental forms of life. It seems far
more likely that the allantois came to atrophy and the pouch tobe ~~
developed, and that so the modern marsupial structure was initiated;

* So says Professor Owen, Philoso- + See ante, p. 504.
phical Transactions, 1865, p. 676. |

es Te eee er Uh re ee! Ee eee

cHaP. Xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 517

than that the allantois should first appear as a functionless rudi-
ment. It also seems more probable that the habit of forming milk
teeth is one which has been lost or almost lost in certain mammals,
than that the process should first have arisen through the replace-
inent of a single, relatively unimportant, tooth, by a vertical successor
to it—a condition which has been found* to be the case in the
marsupials of our own day.

§'7. The succession of mammalian carnivorous life—the mammalian
portion of the cat’s PEDIGREE—may then be represented as follows :—

From unknown Insectivora-like mammals, two diverging series of
forms may have started, one soon leading to Arctocyon (as the
Insectivora-like root of the placental Carnivora), the other series
developing such forms as Proviverra, Hyenodon, and Pterodon, and
continuing on the main stem through Gymuura-like creatures to the
moderu Jnsectivora. From this insectivorous stem we may 1magine
a side-shoot to be given off leading through Paleonictis to forms
like certain existing marsupials, and diverging into the American
Didelphys and the analogous Australian Dasyurus. From Arctocyon
we may conceive the great carnivorous branch—destined to quite
surpass and overshadow the insectivorous stem—to divide into
cynoid and arctoid branches. The former continuing on through
Cynodon and Cynodictis, would lead up through Galecynus and
forms like the existing Otocyon to the typical Canide. The great
arctoid branch may have given off a limb leading through Amphicyon,
Hyenarctos and kindred forms, to the existing Urside, aud then
continued on through Proelurus and Lutrictis, as the Mustelide.
From some such form as Proelurus the great A¢luroid sub-order
may have started, and before continuing on, as the Viverride, have
given off a great branch to be developed, by bifurcating, into the
Hyenide,Cryptoproctide and Felide. The first family is the culmina-
tion of one division which passes through Ictitherwm, and which
gives off Proteles as a one-sided branchlet. The other division into
which the Aluroid branch bifurcates, continues on as the cats, first
giving off however, near the bifurcation, the branchlet ending in
Cryptoprocta. ‘The proper feline branch then continues on through
Archelurus, Dinictis, Nimravus and Pseudelurus, and then bifurcates.
It ends in the typical genus Fels on one side—an aberrant twig
being given off for Oynelurus—while on the other side it continues
on though Hoplophoneus, Pogonodon and Macherodus + to the very
specialized aberrant form Eusmilus.

This hypothetical genealogy is only offered as a speculation, especi-
ally that part ofit which represents conditions anterior to the evolution
of the viverrine branch. It reposes mainly upon dental characters,
and teeth are organs which not only might be expected to vary with

_ * By Professor Flower. See his paper | the ‘‘ali-sphenoid canal” may well have

in the Philosophical Transactions, vol. | independently disappeared and again, by

elvii., 1867, p. 631. reversion, reappeared in either sub-
+ The small lamina of bone whichem- | division of the feline branch.

braces the external carotid and so forms

A apee 1 LE! eo REL S ACRE SONOS Deke 2s oo Se
‘ ’ on PG lhrigt? iefeel I ce dn || Sa

518 THE CAT. - [owap. x

varying conditions at life, but which we know to be sometimes very
differently formed in different members of one and the same family.
Yet we must accept their evidence or none. It is the only evidence — q
which is largely available, nor will there be much danger of serious
error in making use of it, if the caution here offered as to its defec-
tive nature be duly borne in mind. 7

Eusmilus.
Naa

Mache \ rodus.
Felis.

Pogon \ odon.

Hoplophone \ us. Cynelurus.

Insectivora,

Pseud|zelurus.

Hyenide. Urside. Canide,
Nimr javus. Mustelide.
Otoclyon.
Dinijetis.
Cryptoprocta. Dasyurus.
Proteles. Gym{nura,
Arches}lurus. Galec}ynus.
Viverrides. Tene menean Didelphys. ’

Hyeenjarctos.
Lutrjictis,

Cyno}dictis.

Amph icyon.
Prozlurus? Paleonictis.
Cynojdon.

Pterjodon.

Hyzn|odon,
Arctocyon.
Provijverra.

ry
eee:

§ 8. If we can only conjecture with more or less probability wheels
were the older mammalian ancestors of the cat, we are still less able
to determine the line of its descent through non-mammalian ances- —
tors. The structure of the shoulder girdle of the Monotremes, may —
be held to point towards a reptilian origin of the Mammalia; but —
the position of the ankle-joint and the constant development in

4

cHAP. xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 519

every species of two occipital condyles rather indicate a Batrachian
ancestry. On the whole it seems probable that the Mammalia, and
therefore the ,Cat, descended from some highly-developed, somewhat
Reptile-like, Batrachian, of which no trace has yet been found. The
yet more remote ancestor of such Batrachian will have to be sought
amongst extinct and unknown fishes, intermediate between Ganoids
and Elasmobranchs, but with considerable fundamental affinity to the
Rays, however different from them they may have been in external
aspect. Beyond this point no suggestion worth making can be
offered. The genetic relations of the Tunicates and the Vertebrates,
or between either of these and any worms intermediate between
Tunicates and Vertebrates, which may have existed, cannot be
spoken of as even probably known.

§ 9. The foregoing suggestions are offered as results which seem
to present themselves to the inquirer into the past history of
animal life, and into the cat’s pediyree.

The next question refers to the cat’s ortcin. This second
question refers, as before said, to the probable causes which have
determined that process of evolution which has, in fact,. taken
place. It is a question of causation: It investigates the “how”
and the “‘why” of the origin of the cat’s species, and—as we
cannot suppose that the cat is different in this respect from other
animals—the cause of the origin of species generally. Evidently
that cause must lie either within or without the lving organisms
which are évolved, unless it be partly within them and partly
external to them.

We may conceive the evolution of new specific forms to have
been brought about in one or other of the six followimg ways.
The change may have been due :—

(1) Entirely to the action of surrounding agencies upon organ-
isms which have merely a passive capacity for being
indefinitely varied in all directions, but which have no
positive inherent tendencies to change or vary, whether
definitely or indefinitely ;

(2) Entirely to innate tendencies in each organism to change in
certain directions ;

(3) Partly to mnate tendencies to vary indefinitely in all direc-
tions, and partly to limiting tendencies of surrounding
conditions, which check variations except in such direc-
tions as may happen to be accidentally favourable to the
organisms which vary ;

(4) Partly to mnate tendencies to vary indefinitely in all direc-
tions, and partly to external influences which not only
limit but actively stimulate and promote variation ;

(0) Partly to tendencies, inherent in organisms, to change defi-
nitely in certain directions, and partly to external
influences acting only by restriction and limitation on
variation ;

(6) Partly to innate tendencies to change definitely in certain

520 THE CAT. [cuar. xv

directions, and partly to external influences which, in
some respects act restrictively, and in other respects act
as a stimulus to transformation.

The writer has elsewhere* stated at length his reasons for con-
cluding that the genesis of new species is due mainly to an
internal cause, which may be stimulated and aided, or may be
more or less restricted, by the action of surrounding conditions:

The notion that the origin of species is due to “ Natural Selec-
tion,” is a crude and inadequate conception which has been weleomed
by many persons en account of its apparent simplicity, and has
been eagerly accepted by others on account of its supposed fatal
effects on a belief in Divine creation. .

Its anti-theological character has been declared by a conspicuous
English advocate, to be “one of its greatest merits,” while it has
been made use of as a fundamental dogma in the various polemical
works of Professor Haeckel.

The present author’s views as to “Natural Selection” havi ing been
already fully expressed in former works, it is not thought necessary
that further space should here be occupied by their repetition.

§ 10. Before entermg upon the question of “ Origin,” a few
words of preliminary explanation seem to be needed. Obviously
before we can enter profitably upon the discussion of any pro-
position, we must clearly understand its terms, and it would be a
useless task to discuss the origin of anything as to the very
existence of which we may have reason to doubt.

Before enquiring into the origin of species, it will be well to
make sure what we mean by a “species,” and that there really
is any such thing.

We have to Coaae the origin of the cat, as a “ species’ of
the genus Felis, of the family Felide. What pe is a “species,”
what a ‘“ genus,” and what a “family?” Who has ever seen or
handled one of these entities ? Individual cats and cat-like creatures
of various kinds abound, but no one pretends to have anywhere
met with a “family ” ora “genus.” Why then should a “ species”
be spoken of as if it had more reality im it than they? In fact it
has just as much and no more reality than they have. A “species,”
like a “genus,” or a “ family,” or an “order,” or a “class,” is an
IDEA; and its existence, as a species, 1s only ideal.

Has it then no reality whatever? Undoubtedly it has. A species
is real, inasmuch as any individual animals actually have in the
concrete those very characters and powers which exist abstractedly
in the idea of the species. It is just the same with every “ genus,”
“‘family,” “order,” and ‘“‘class.”” Each and all of these are ‘‘real,”
inasmuch as the abstract ideas they may severally refer to, are
concretely embodied in numerically separate and distinct, individual,
material, living creatures.

* See the ‘‘ Genesis of Species,” and also Chapters VIII., IX., X., and XIV.,
** Lessons from Nature.’

aa. a)

~~ ee

cHaP. xv.] THE PEDIGREE AND ORIGIN OF THE CAT 521

To seek, then, the genesis of species, as svecies, would be to in-
vestigate the origin of certain ideas. But that would not be at all
the object here pursued. That object isto enquire how it is that a
certain concrete entity (a certain animal, which is the hving
embodiment of one idea) gives rise to another concrete entity—
which is the living embodiment of a different idea.

§ 11. Now all our knowledge being derived from experience, we
can only (revelation apart) judge of things as they have been, by
things ag they are; and as every animal is now the product of a
parent organism more or less like it, so the natural inference with
regard to any antecedent animal, is that it also was the product of

a parent organism more or less like it.

But it may be said: ‘this analogy does not apply to the embodi-
ment of a new species, because ”’ (it may be asserted) “‘ we never see
the origin of such an embodiment—we never see anything lke a
change of species: we cannot, therefore, from our present experience,
even guess what may have been the mode of appearance of a con-
crete entity embodying an idea different from that embodied by the
entity which preceded it.”

This assertion, however, is here denied, while it is on the contrary
affirmed that we do see—as far as human eye ever can see or ever
could have seen—the origin of concrete embodiments of ideas which
are not only as distinct as one species from another, but as distinct
as genera, famiiies, orders, classes, and even kingdoms, one from
another. It is also here contended that we may see this daily, even
in the case of the cat.

It was this consideration—an anticipation of the argument here
to be advanced—which caused the facts, and the significance of the
facts, of the cat’s embryonic development to have been so dwelt
upon, as they have been in the tenth chapter of this book. Tor the
incipient embryo of the cat, is no cat: it 1s not even an animal. Its
existence 1s merely vegetal, and the successive ideas which it em-
bodies (in the course of its evulution) approximate only by degrees to
that embodied by the adult animal. The embryo which is to become
a cat, successively embodies ideas which are analogous to, though
they are never identical with, those which are manifested in rhizo-
pods, sponges, worms, fishes, batrachians and other inferior animal
natures. We see these changes as facts; the actual “how,” the
intimate mode in which the living idea or form.is embodied in and
identified with the matter it informs, is one of those impenetrable

secrets of nature for ever closed to human ken, as the mode in which

—the actual “how’”—the mind is enabled to know itself and
things external to it, is closed to human ken. None the less, every-
one who admits that the livmg cat when adult is informed by a
psychical principle of individuation, may be called upon also to admit
that its developing embryo is successively informed by psychical
principles of individuation of different orders—orders which present

‘no trifling analogy to different orders of animals which exist perma-

nently. After the true cat form has been once attained, such changes

522

cease, and, till death, the cat remains a cat simply.
however, the process of change recommences (though it is a very
lifferent process), and continues during the gradual recession of all
those forms which have any relation to life, till the body is reduced

to mere inorganic matter.

§ 12. According to our present experience then, we ought to
anticipate that any new ideal embodiment—any new specific form—-

THE SCAT.

[CHAP. XY.

With death,

would make its appearance during the period of embryonic life, and
that if a new: cat-species is to appear, it will appear as a kitten

which differs more or less markedly from its parents.
is by no means against experience.

Such a birth

It is not merely that minute

changes occur—no two individual animals being absolutely alike—
but every now and then a marked variation takes place, as in the

case of the kitten seen by Mr. Birkett.*

Such variations also are

capable of being transmitted to the offspring cf the animals in which

they first arise.

But we may even gather some evidence in favour of the origin o

f

species by considerable and not minute changes, from the special
subject of this work—the group of Cats. Species of Machcerodus, like
Smilodon, were, aS we have seen,t unable to kill by biting on
account of the enormous length of their upper canines, which could
only be used as daggers, the mouth bemg closed. All existing
feline animals, including the long-tailed, clouded tiger (F’. macrocelis),

bite, and are unable to use their canines as daggers.

Now, if the

canines of Macherodus Smilodon had been formed by minute increase
in successive generations, the creatures would at one time have been
in a condition such that their teeth were too long to be conveniently
used for biting, while they were not yet long enough to be ethciently

used as daggers.

It is true that there are different species of

Macherodus with teeth of very different lengths, and it is also true
that before the canines became so long as to be quite useless for

biting, they would begin to be slightly useful as daggers.

Still the

fact remains that a highly inconvenient transitional stage of exist-
ence { must have been passed through, if evolutionary changes were

* See ante, p. 7. Amongst new organic
forms known to have been suddenly
evolved are: The black-shouldered pea-
cock, new forms of wild deer, a smooth
capsuled kind of Datura tatula, a com-
plex-capsuled form of poppy, &c., &c.

+ See ante, p. 432.

+ Professor Cope has said (see Pro-
ceedings of the Acad: of Nat. Sc. of
Philadelphia for July 8, 1879) :— ‘‘l
think there can be no doubt that the
huge canines in the Smilodons must
have prevented the biting off of flesh
from large pieces, so as to greatly inter-
fere with feeding. . . . The size of the
canines is such as to prevent their use as
cutting instruments, excepting with the
mouth closed, for the latter could not

have been opened sufficiently to allow
any object to enter it from the front.
Even were it opened so far as to allow
the mandible to pass behind the apices
of the canines, there would appear to be
some risk of the latter’s becoming caught
on the point of one or the other canine.”
As to the cause of the disappearance of
this highly specialized form of life, Pro-
fessor Flower has observed (in a lecture
delivered at the Royal Institution on
March 10, 1876) :—‘‘It may have been
a case of over-specialization, in which
the development of the carnivorous type
of dentition, gradually accumulating in
intensity . .. , became at last a succes-
sive inheritance so exaggerated that its
growth outran its usefulness of purpose.

. —, * 2
a, '

aq

BS

;

%,

cHAP. xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 523

always minute changes. If, however, a sudden and considerable
change took place, this difficulty, in the way of evolution, would be
completely evaded. But what is here said of Machwrodus, has a
wide application. Were not forms of life evolved by a process which,
compared with their duration, is “‘sudden,” the world would be a
zoological chaos. But such is not the case. A multitude of un-
doubtedly stable and plainly distinct kinds exist now, and thence
we may conclude that stable and distinct kinds always existed, how-
ever difficult the definition of some forms may be in certain cases.
Returning from this digression to the question as to the mode of
individual development and evolution, if we extend our view beyond
the class of mammals, far more striking phenomena will present
themselves to our notice than any with which we have become
acquainted in studying the development of the cat. Thus in the
development of such an animal as the frog, we find that two
remarkable transformations take place. One of these is the trans-
formation of the egg into a fish-like tadpole, the other is the
transformation of the tadpole into the frog. In that singular species
of Mexican eft, the axolotl, we find that a few individuals will every
now and then (under the stimulus of certain conditions of their
environment) quickly undergo a transformation, not merely of
external appearance, but one which affects their very skeleton, and
changes the distribution of the teeth in their jaws. In insects, as
e.g-, in- the butterfly, we have the well-known marvellous meta-
morphosis which is effected during the period of its existence as a
quiescent chrysalis. Other lowly animals undergo still more sur-
prising changes, which in many of them, as in the Tunicates, may
1esult in the production of an adult form which is of a dower order of
organization than that of the transient being which served to evolve
it. Such facts as these show how probable it is, that at various
different stages of individual evolution, sudden changes caused by an
acceleration or by an arrest of the development process, or even by
some retrogressive action, may have resulted not merely in the
production in the concrete of new species, but even of a new genus,
a new family, or a new order; for we see equivalent changes going
on before our eyes now.* 7 |

. . . Such appears to be constantly the | above instance as to the dangers likely
fate of forms which have become over- | to result to any race of mankind from a
specialized, or in which the development | one-sided, ill-balanced development of
of one part has run on in one particular | those intellectual powers which give man
direction out of due proportion to the | supremacy over all lower forms of life.

rest of the organization. We know that * Some readers may feel a difficulty in
it is quite possible, by artificial selection, | accepting the view here put forward (as
to produce animals with one particular | to the serial succession of different
part developed even detrimentally to the | psychical principles of individuation in
entire economy of the creature, and it | the development of each _ individual
eally seems as if something of the same | animal suchas the cat, frog, or butterfly),

kind not unfrequently occurs in nature.” | on account of the gradual mode in which
It is indeed true that for the perfection | even rapid metamorphoses take place.
of any living creature there is need of The tadpole only by degrees becomes a

harmony between its various powers, | frog, and gradual processes of change
and a moral may be drawn from the | take place within the seemingly quies-

524 THE CAT [CHAP. XV.

§ 13. It may be said that we even see the fresh starting forth of
life itself. In many plants, the ovule (after developing to that extent
which is its condition in the fully formed seed) ceases to be active.
The seed is shed and dies. But on the occurrence of the requisite con-
ditions, it lives again and comes rapidly to manifest a new psychical
principle of individuation altogether different from that which informed
the same matter when it was a deyeloping seed. It may, perhaps,
be objected by some persons that: ‘if the seed is not actually hving

during its’ period of quiescence, the result shows that it has neverthe-

less been potentially alive.” But it is impossible to understand how
anything can be really “alive” when all vital activity is really
absent, and no such activity can be affirmed to exist during the long
periods * in which dry seeds may be preserved without decomposi-
tion. The “ vital activity ” of a seed is “ germination.”

As to “potential life,” its existence may be freely conceded ; but
potential *‘life” is actual “death.” The “potentiality” is not im the
seed merely, but in the environing conditions and external stimuli
also, yet ‘life’? is not to be predicated of such “conditions” and
‘‘stimuli.” The dead seed is but a piece of matter so appropriately
formed thatifit and other matters are brought together under certain
conditions, a new living being results from the conjunction. This is
but a case of that genetic activity which all persons who believe that
life first arose spontaneously in the world, must admit to have once
existed, and if “ once,” why not “always?”

§ 14, But how are all the changes of development in the cat, and
in all animals and plants, carried on? Is it by a number of fortuitous

cent chrysalis. It may be asked then: { continue to inform a body while that
How can a new ‘‘form” suddenly arise, | body undergoes various changes and
when the body it informs arises gradu- | gradual modifications within certain
ally? But are not a piece of oak, and | limits; but will cease so to exist when
woodashes, different substances? Yet | once those limits are passed. Theactual
does not fire yradually effect the trans- | amount of change which the body ofa
formation of the former into the latter ? developing animal can undergo while
Our organs of sense are indeed so con- | informed by any one principle, and the
structed and so act that they are in- | physical conditions which determine the
capable of positively seeing any absolute | lapse into potentiality of that principle
commencement whatever. When we seem | and the advent of another, may ever
to perceive such a thing (as, ¢.g., in the | remain a matter of speculation only.
explosion of gunpowder), the apparent ; There appears, however, to be evidence
absolute suddenness is but due to the fact | that such changes actually take place,
that the gradual changes which really | and the gradual preparation of the living
take place are too minute and too rapid | matter for their occurrence is a phenome-
for our sense-organs to follow. There | non which harmonizes with our experience
can be no doubt but that if our powers | as to the only psychical principle of in-
of sense were in these respects greatly | dividuation of which we have any
augmented, an explosion of gunpowder | thorough knowledge—our own.
would then be seen by us to be a gradual * Mr. Carruthers, F.R.S., has kindly
process. informed me that seeds of Nelwmbium
But the emergence of a new psychical | (a beautiful aquatic plant belonging to
principle of individuation is a thing | the Lotus group) have germinated aiter
which is and must ever remain essentially | having been preserved in the British
imperceptible to oursenses, howevermuch | Museum for upwards of a hundred years.
their powers might beaugmented. Each | In this case it is manifest that all vital
such psychical principle can—as we | activity was fora very long time really
know by our own personal experience— | abseut.

cHap. xv.| THE PEDIGREE AND ORIGIN OF THE CAT. 525

changes, and by phenomena without order, and apparently subject
to nv law? Surely it is the very reverse! The transformations,
the successive embodiments of new ideas of all ranks and degrees,
which are daily taking place in countless myriads on all sides of us, take
place harmoniously and in due order. However singular or surprising
may be the process of evolution in certain cases, however round-
about its course, or unexpected its intermediate stages and ultimate
outcome, it is in each and every case a process carried on according
to definite internal laws to fulfil a precise * and predetermined end.

What we find to be the case now, we ought, if we are to take
experience as our guide, to regard as having been the case ante-
cedently. ‘Thus the process of specific evolution in the past will
have been no process effected by a fortuitous concourse of influences,
or by minute haphazard variations in all directions, but by a definite
system of internal law, aided and influenced in the past as it is
aided and influenced now, by the action of incident forces, also
operating according to law, and resulting in due and orderly “‘ specific
genesis.”

§ 15. The idea of an INTERNAL FORCE is a conception which we
cannot escape if we would adhere to the teaching of Nature. If, in
order to escape it, we were to consent to regard the instincts of
animals as exclusively due to the conjoint action of their environ-
ment and their physical needs, to what should we attribute the
origin of their physical needs—their desire for food and safety, and
their sexual instincts? If, for argument’s sake, we were to grant
that these needs were the mere result of the active powers of the
cells which compose their tissues, the question but returns—whence
had these cells their active powers, their aptitudes and needs?
And if, by a still more absurd concession, we should grant that these
needs and aptitudes are the mere outcome of the physical properties
of their ultimate material constituents, the question still again
returns, and with redoubled force. That the actual world we see
about: us should ever have been possible, its very first elements
must have possessed those definite, essential natures, and have had
implanted in them those internal laws and innate powers which
reason declares to be necessary to account for the subsequent out-
come. We must then, after all, concede at the end as much as we
need have conceded at the outset of the mquiry.

Potent amongst the agents operating in the process of specific
evolution must be that internal, individual, psychical foree—that soul
or psyche—which we have seen reason postulates as the most
important, though invisible, constituent of every concrete living whole.
It must play this predominant part, because it is by its action that
the whole multitudimous and diverse processes of life are co-ordinated

* Some persons may think that the ! some accident is in contradiction with
occurrence of monstrous births, &c., con- | the harmony of Nature’s laws. But an
stitutes an objection to the above state- | accident occurring before birth is no
ment. No one however imagines that { more in contradiction with such harmony
the fact of a man becoming lame through ; than is an accident to an adult.

*

ee

SST

526 ; THE CAF. [CHAP, XV.

and controlled into that unity which we perceive in each separate
living organism. | |

All nutrition, growth, and reproduction are normally controlled
and ultimately effected by it, no less than all motion, feeling, and
cognition. Therefore it 1s by it that those physical changes are
effected which, during the process of individual development, so
change the conditions of the matter of the body, as, by degrees, to
render it unsuitable for the form actually embodied in it, and to
prepare it to receive that form which comes next in the order of
evolution.

§ 16. This is what is really meant by the assertion that the
genesis of species. takes place mainly through the agency of an
internal force,* and this mode of origin may—as opposed to the
hypothesis of natural selection—be fitly termed PSYCHOGENKSIS.

§ 17%. But the further question may yet be asked, what de-
termines the origin of species by psychogenesis? What controls

and directs the successive evolutions and disappearances of these

various “ forms” or psychical principles of ndividuation—“ forms ”
which ever arise in due order and succession now, and which we
may therefore infer to have arisen in due order and succession
through the countless ages of past organic activity ?

To this question no reply is possible without passing from questions
of physical science to the highest problems of philosophy. But no
natural object can be fully understood without reference to such
problems, and to shrink from explicitly referring to them here,
would be a dereliction of scientific duty. The consideration of the
action and nature of no cause which there is reason to suppose
influences the formation of living creatures, can fitly be omitted
from the study of the evolution of any form of life.

The observer of nature who contents himself with considering
external phenomena and does not reflect on his own intellectual
powers and the similar powers of his fellow-men—such a partial
observer of nature may perhaps conceive of the cause thus operating
in evolution as unintelligent. He may deem it to be some principle
utterly inconceivable by us, pervading all space and enduring
through all time, yet devoid of consciousness and will. He may
deem it to be a force incapable of apprehending what it produces,

but which is at the same time the origin of all law, all beauty, and

all intelligence.

But let us see what such a conception really means. It is
admitted that we cannot transcend experience. We cannot then
imagine a first cause save in terms the elements of which are within

* This conception, put forward in | by ‘‘unknown agencies” lying deep in

——— ee ee ee eee eee

‘The Genesis of Species,” seems to be
now practically admitted, even by the
author of ‘‘The Origin of Species,” for
the latter has come to admit that ‘‘abrupt,
strongly marked changes,” may occur
‘‘neither beneficial nor injurious ” to the
creature which exhibits them, produced

‘the nature of the organism!” It is
hardly necessary to point out that with
respect to such developments, ‘* Natural
Selection ” must be absolutely impotent.
Upon such changes it cannot possibly
exert any influence whatever.

|
:
:

ee Se | Se eee el ee oe el

cHap. xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 527

that experience. Now the highest entities thus known to us are
human intellect and human will. Besides these, we know only the
merely animal, the vegetal, and the inorganic worlds. Should
we then imagine the Universal First Cause in terms of some gas or
some merely physical force? Such a conception has but to be
stated to show its absurdity. But if we attribute to the Great Cause,
active in organic nature, an activity which is intelligent in its
results, but not in itself—not in the agency which produces those
results—we thereby attribute to it a sort of cmstinct, and, in order to
avoid the error of anthropomorphism, we fall into the vastly greater,
and more absurd, error of soomorphism !

We have no choice, then, but to imagine this Great Cause in
terms derived from human nature while confessing their madequacy
and being careful to render them as little inadequate as is possible,
by considering all that is positive m them as raised to infinity, and
at the same time eliminating from the conception all that is negative
and imperfect.

When, however, extending our view over the whole of Nature,
we'include in our study man’s faculty of apprehending truth, good- -
ness, and beauty, together with his wonderful power of occasionally
controlling by his free will his own thoughts, desires, and actions, and
so actively intervening in the chain of physical causation, the idea of
the first cause as God becomes evident to the mind; nor can it be
rejected without self-stultification. The denial of the validity of

this inference involves a negation of facts and of intellectual prin-
ciples, which negation carried out to its logical consequences destroys
itself by the sceptical destruction of those very premises on which
that denial must itself repose.

The philosopher then has the strongest possible ground for affirm-
ing (in reply to the question as to the cause of Psychogenesis) that
in the process of evolution we have evidence of the activity of a
Great First Cause, ever and always operating throughout nature in
a manner hidden indeed from the eye of sense, but clearly mani-
fested to the intellectual vision of every unprejudiced aan This
action | Is that secondary or derivative creation,* ‘ per temporum
moras,” distinguished by St. Augustine, from that instantaneous
primary creation which took place, : potentialiter atque causaliter,’
in the beginning. Thus a belief in “ evolution ” far from leading to
a dental of “creation;” distinctly affirms it.

Indeed the candid study even of merely organic life makes
evident the logical need which exists for the Theistic conception.
The course of individual development as it goes on in every kitten,
shows the existence of a ‘final, no less than of an efficient cause of
the developmental process. Anyone who would pretend that the
mere conflict of independent efficient causes can produce a co-ordi-
nated series of effects, resulting in the attainment of a definite end,
which they have all concurred to produce, would certainly go against

* See ‘‘ Lessons from Nature,” p. 429. »

528 THE CAT. [CHAP. XV.

all our experience. Anyone, also, who should pretend that we cannot
affirm a ‘ purpose ”’ to exist in different natural processes (.e., who
denies that we can assert a “final cause” for any phenomenon)
because we are unable to state the final cause of the whole series of
physical phenomena, would be like a soldier who, because he was —
ignorant of the plan of campaign of his commander-in-chicf, should
pretend that therefore he could not infer that commander’s purpose
in sending medical stores to the military hospital.

The co-operation of a variety of actions under complex conditions
in the production of something which works well and which is the
admirable practical result of their harmonious co-operation, supposes,
as our experience shows, a cause in which that future phenomenon
is ideally represented; and the more complex the conditions, and
the more numerous the actions may be, the more certainly may the
conclusion be drawn that such prevision existed.

The Theistic idea once accepted, how does the action imminent in
nature accord with our idea of God, thus conceived ?

Surely it is just that sort of action which was to be expected. It
is an action which harmonises with man’s reason, which is orderly,
constant, and universal, yet which ever eludes our grasp, and is
effected by ways and in modes very different from those by which
we should have attempted to accomplish such ends.

As to “creative action,” reason tells us nothing more than that
its existence must be logically inferred. It cou/d tell us nothing
more, since of it we cannot possibly have had any experience what-
ever. Those men are strangely inconsistent who would deny it
because they cannot imagine it, since they must confess that it must
be unimaginable by them (even if they were in some way made
certain of its existence) on account of their never having had any
experience of it.

§ 18. But to revert to the question of the Origin of Species. Let
it be granted that Divine activity evolves new concrete forms by
final and efficient causes (making use of living organisms as means),
are these all the causes which operate, or is there yet another cause ?

Species, genera, families, orders, and classes, as such are ideas;
they have an ideal existence in the human mind—have they no
other ideal existence ? Every Theist must admit that the mind of
God contains all that exists in the human mind, and infinitely more.
It is therefore a simpie truism to say that human general concep-
tions, gathered from nature, must be ideas in the Divine mind also
—such human conceptions being but faint and obscure adumbra-
tions of corresponding ideas which must exist in their perfection and
fulness in the mind of God. But there is yet a further considera-
tion. - Our ideas are ideas derived from material things, while the
Divine ideas are ideas whence material things have been themselves
derived. This must be so, since God is eternal, and these ideas, as
His, must be eternal also; whereas all the most ancient concrete
existences in which such ideas are embodied, are relatively but
creatures of yesterday.

cuap, xv.]| THE PEDIGREE AND ORIGIN OF THE CAT. 529

Human ideas are “true,” in so far as they correspond with really
existing things external to the human mind. But really existing,
external things are themselves “ true,” in so far as they correspond
with the eternal, archetypal or prototypal ideas of God which are
their exemplar cause.

The wondrously varied world of phenomena which presents itself
on every side to the human senses, is to those senses but a confused
mixture of sounds and colours, odours, tastes, and touches. It is
the intellect whick puts ideal order into the sensuous chaos, recog-
nising subjectively that external order which in fact exists objec-
tively. Amongst the orderly. phenomena which cultivation enables
the intellect to apprehend, are the variously related ideal concep-
tions—species, genera, families, orders, and classes—which have
their objective reality and foundation in the actually existing charac-
ters of concrete material objects. We are able, moreover, not only
to recognize that these ideas exist, but also to recognize that they
form a hierarchy of conceptions. We thus come to apprehend that
an idea embodied in some large group of creatures—some order—is
carried to a more thorough and definite expression in some one
family of that order, and to a still more intense degree in some
genus of that family. It is thus that we recognize in all beasts
the concrete embodiment of the mammalian idea, and in the car-
nivorous type, a special, perhaps the highest, expression of that idea,
which is carried out to its fullest manifestation in the typical Felide.

We see then that the feline form is the most complete expression
yet realized of that exemplar ideal which is less fully expressed by the
carnivorous order considered as a whole. Thus viewed, the creatures
to the special consideration of which this work is devoted, are seen to
exhibit multiform relations of a very elevated character. Evolved
through the action of antecedent organisms (of increasing specializa-
tion of strucvure) as their efficient cause, they have for their final cause,
the external realization in the material creation of one of those proto-
typal ideas which are the several exemplar causes of the world of
organic life, and which have eternally preceded every creative act.
Interesting then as the animals which have here occupied us are to
the zoologist, the physiologist, the geographer, the geologist, and
the psychologist, they are most of all interesting to the philosopher.
The true philosopher will never rest satisfied with a knowledge of
material and efficient causes alone, but will ever seek to obtain
what glimpses he may of those other causes which his reason tells
him can never be absent from a world which is the outcome of a
Divine Intelligence. Only at last will he rest satisfied, when,
having traced as far as he may, the series of secondary causes, he is
able confidently to refer to the evident though hidden action of the
Great Author of Nature. Reason exhibits to us the whole Cosmos
as proceeding from Him, and only when the study of his creatures
ends by leading the student back to Him from whom they pro-
ceeded, can that study be said to be “rational” in the highest

— sense of that word. Then only is it truly worthy of that admirable
; MM

1

530 THE CAT.

human intellect which sees in the concordance between subjective
reason and the rational laws of the objective universe, evidence that
the human intellect itself has been created in the image and likeness
of that intellect which is Divine. :

§ 19. Our endeavour in the pursuit of knowledge should be humbly
but zealously to follow that natural impulse implanted in us, to
synthesize as well as to analyse, and above all to be untiring in the
pursuit of causes. Of the scientific man it may indeed be said:

Feliz qui potut rerwim cognoscere causas.

No knowledge of mere facts and phenomena, however multitudin-
ous and varied, will suffice to constitute “ scrence.” The essence
of ‘all science is a knowledge of causEs, and only when all the
phenomena embraced by any given study have been referred to
their immediate causes, and when all their more remote causes have
been duly investigated, and their several inter-relations clearly
understood, will that study be able to take its place as a perfected
“science.” Great has been the progress of this kind which Biology
has made during the last half century. Full of hope and promise
is the prospect before it, long as must be its course before its per-
fected con‘ition can be attained.

§ 20. To help on its progress, no course is perhaps more useful
than that of the careful study of a succession of TyPEs belonging to
different families of living begs. Amongst the multitude of such
groups, that one has been here selected for examination which has
been deemed most likely to be useful to the earnest enquirer in
biological science who is beginning such a course of study. No
more complete example of a perfectly organized living being can
well be found, than that supplied by a member of what has no in-
considerable claims to be regarded as the highest mammalian family
—the family Felde.

eT = i i ek

eM E UL

* * The scientific names of Cats are printed in Italics.

AARD-VARK,

AARD-VARK, 468.
Abdominal aorta, 210.
ad _ cavity, 176.
an muscles, 141.
35 ring, 141, 143.
esas, 273.
Abductor brevis pollicis, 152.
se indicis, 162.

a minimi digiti (of fore-paw), 152.

2; minimi digiti (of hind-paw),
162.

o muscles, 129.

Aberrant forms, 490.
Absorbent vessels, 217.
Absorption, 167.
Accessorius, 161.
Accessory organs of respiration, 222.
Acetabulum, 106.
Achromatism of eye, 295.
Acromial thoracic artery, 209.
Acromion, 90.
Action of bile, 188.
» Of gastric juice, 180.
», of pancreatic fluid, 184.
»» of saliva, 174.
3, of spermatozoa, 318.
of vibratile cilia, 175.
Actions (our unconscious ones), 384.
»» Of muscles, 129.
» Of orbital muscles, 294.
Active powers of cat, 370.

- Activity (nervous), 305.

Acts (mental), 386.
Adductor of thigh, 157.

an muscles, 129.

ns minimi digiti, 152.
Adipose tissue, 17, 18.
Ailurodon, 437, 502, 513:
fEluroidea, 475, 480.

3 phylogeny of, 513.
African cats, 496.

grey, 407.
Agreements between muscles of fore and
hind limbs, 163.

Ailuride, 475.
Air (its composition), 221.
Air-cells, 225.

a of lungs, 223.
Alar ligaments, 54.
Alar thoracic artery, 210.

ANTERIOR.

Albumen, 12.
Albuminoid substances, 166.
Alimentary system, 165.

pe canal, origin of, 341.

processes ‘summarized, 168

Alimentation, 165.
Ali-sphenoid, 69.
Allantois, 325.

question as to its origin, 517.

Alligators, 462.
Alveolar border, 73.
Alveoli, 27.

e of lungs, 223, 225.
Amblyctonus, 506.
American cats, 495.

Amnion, 322.

Ameebe, 450, 454.

Ameeboid movements, 194, 454.
Amphiarthroses, 121.
Aniphicyon, 518.
Amphilestes, 504.
Amphioxus, 455.
Amphistoma truncatum, 509.
Amphitherium, 504.
Amphiuma, 459.

Ampulle, 300.

Amylaceous substances, 166.
Analogies of eye and ear, 303.
Anapophyses, 39.
Anastomoses, 196.

Anatomy, 9

Ancestors of cat, 512.

i premammalian, 518.
Anconeal fossa, 93.
Anconeus, 149.

Angles of rib, 51, 52.
Angora cat, 6.

Animal functions, 10.
Animals no automata, 383.

», What they are, 445.

Ankle-joint, 118.
Annelids, 450.
Annulus (of fore-paw), 99.
Anococcygeus, 144.
Anomalurus, 469.
Ant-eaters, 468.
Antelopes, 467.
Anterior commissure, 265.
iy condyloid foramen, 62.
73 crural nerve, 281, 282.

M M 2

532 INDEX.

ANTERIOR.

Anterior hyoidean cornua, 77.
a nares, 59
hg palatine canal, 74.
» palatine foramen, 74.
oH pyramids, 263, 268.
Anthropomorphism, 527.
Antiputrescent action of bile, 188.
Antiquity of the cat, 3.
Antitragus, 296.
Anus (formation of), 343.
Aorta, 206.
», abdominal, 210.
55. thoracic; 210.
Apes, 468, 507.
Aphaniptera, 510.

- Apnoea, 221.

Aponeuroses, 124.
Appendicular skeleton, 34, 89.
ss a (its serial homo-
logies), 120.
Appendix of cecum, 183.
Aptera, 510.
Apteryx, 462.
Aqueduct of Fallopius, 66.
Aqueous humour, 294.
Arachnida, 510.
Arachnoid, 257.
Arch of aorta, 207.
Archelurus, 436, 502, 518.
Archetypal ideas, 529.
Arctocyon, 506, 514, 518.
Arctoidea, 474, 477.
Areolar tissue, 22.
Armadillos, 468.
Arrangement of peritoneum, 189.
Arterial blood, 195.
Arteries, 196, 206.
branches of carotid, 203.
i development of, 346.
Artery, acromial thoracic, 209.
alar thoracic, 210.
axillary, 209.
basilar, 209.
brachial, 210.
bronchial, 225.
capsular, 211
caudal, 213.
circumflex, 210.
coronary, 206.
coronary of stomach, 211
dorsal of foot, 214.
epigastric, 213.
external iliac, 213.
femoral, 213.
hepatic, 187, 211.
hypogastric, 213.
iliac, 212.
innominate, 207.
intercostal, 209, 210.
internal iliac, 213.
internal mammary, 209.
interosseous, 210.
long thoracic, 209

99.

es

AZYGOS.

Artery, obturator, 213.
» ovarian, 211.
»> peroneal, 213.
», phrenic, 209, 211.
», profunda, 210
», pudiec, 213.
», pulmonary, 206. .
oe kemals 2a 1e
9, spermatic, 211.
y» , USplente, 2ie
», subclavian, 209.
», superior thoracic, 209.
», suprarenal, 211.
550) eet oiall, Met
4 alnar,200!
», uterine, 213.
»> vertebral, 209.
55 VeBIGaly ila.
Arthrodia, 122.
Arthropoda, 450, 452.
Articular processes, 35.
Articulations of pelvic girdle, 116.
Arytenoid cartilages, 228.
Ascaris mystax, 509.
Ascending colon, 182.
a, ramus, 77.
Ascidians, 450, 453.
Aselli (pancreas of), 219.
Asiatic cats, 496.
Asphyxia, 221.
Asses, 467.
Assimilation, 165.
Astragalus, 113.
Atlas, 44,
Attolentes auriculum, 132.
Auditory bulla, 57.
i nerve, 274, 302.
i” ossicles, 298.
Bs », formation of, 339.
Auricles of heart, 205.
Auricular surface, 46, 106.
Auriculo-cervicalis, 132.
is submaxillary, 132.
5 temporal nerve, 273.
Australian region, 500.
Automata and animals, 383.
Automatic motions, 124.
Automatism and consciousness, 384.
RS », natural selection, 384.
Aves, 455.
Axial skeleton, 34.
oa BS development of, 332.
Axile bodies, 22.
Axillary artery, 209.
,) glands,\:2h8,
is nerve, 279.
- veins, 215;
Axis, ossification of, 334.
», cylinder, 254.
5, vertebra, 43.
», and atlas, ligaments of, 54.
Axolotl, 459, 523.
Azygos veins, 217.

a a x anal

INDEX.

BACK-BONE.

BACK-BONE (ossification of), 334.
Badger (the), 475.
Balance of nutrition and waste, 166.
Balanoglossus, 450.
Ball-and-socket joints, 122.
Bandicoots, 468.
Base of skull, 79.
Basi-cranial axis, 84.
a Pp late, 337.

Basi- ‘facial axls, 85.
Basi-hyal, 78.

», occipital, 61.

»» Sphenoid, 69.
Basilar artery, 209.

»» membrane, 301.
Bassaris, 474.
Batrachia, 456, 459.
Bats, 468, 507.
Bay cat, 401.
Bearing of psychology on development,

386.

Bears, 468, 474, 476.
Beasts, 466.
Beavers, 469.
Bell (respiratory nerve of ), 278, 279.
Beni Hassan, 3.
Beroé, 456.
Bertholin’s glands, 246.
Biceps, 148.
», femoris, 158.
Bicipital groove, 91.
,» muscles, 128,
Bicuspid valve, 204.
Bilateral symmetry, 15.
Bile, 188.
Bile ducts, 186.
Bilifulvin, 188.
La 188.
Biology, 8
Birds, 455, 462.
a feet feathered, 377.
Bisons, 467.
Bladder, 235.
gall. 186.
Blastodermic vesicle, 319.
Blind spot, 292, 293.
Blood, 193.
» development of, 331.
», its change of colour, 203.
», its gaseous changes, 221.
», of the kidney, 234.
Blood-vessels (great), 201.
formation of, 345.
Body-cavity, what it is, 26.
Body and soul (reciprocal action), 383.
Body (its mechanical support), 129.
», of the cat, 14.
», of hyoid, 78.
55.e OL-Fib,, 51.
», of sternum, 50.
»» Of vertebra, 35.
- Bone, 19.
», corpuscles, 19.

CAPSULES.

Bone, development of, 331.
»» its growth, 20.
Bony labyrinth, 299.
Bornean cat, 419.
Bothriocephalus decipiens, 509.
felis, 509.
Boundaries of abdomen, 176.
Brachial artery, 210.
oy, |) PLEXUS, 273,
sj) | | Vern, 215.
Brachialis anticus, 148.
Brain, 259.
», development of, 357.
Branchiata, 456.
Breastbone, 49.
Breasts, 239.
Breathing air, 226.
Breeding of cat, 8.
Breeds of domestic cat, 5.
Broad ligaments, 247.
of liver, 185.
Bronchi, 223.
Bronchial tubes, 225.
Bruner’s glands, 181.
Bryozoa, 450.
Bubastis, 3.
Buccal glands, 174.
Buccinator, 133.
Buffaloes, 467.
Burt Wilder (Professor), 377.
Bushy-tailed red-spotted cat, 416.

Cacum, 182.
Cainozoic strata, 501, 502.
Calcaneum, 113.
Calloso-marginal sulcus, 269.
Camels, 467.
Canal (vertebral), 35.
»» ali-sphenoid, 439, 477.
», of Petit, 204,
Canaliculi, 19.
Canalis centralis, 259.
»» membranacea, 301.
»» reuniens, 301.
Canals (portal), 187.
», semi-circular, 300.
Caneelli, 20.
Canide, 474, 479, 518.
Canine teeth, 28.
o. stOSSA,, 73:
Canthus of eye, 288.
Capillaries, 197.
Capitellum, 93.
Capitular surfaces, 37, 38.
Capitulum of rib, 50.
Capsular artery, 211.
veins, 216.
»» ligament of knee, 118.
a o of shoulder, 100.
as of spine, 53.
Ae of thigh, 116.
Capsule of lens, 294.
Capsules (supra-renal), 237.

ol

534 INDEX.

CAPSULES.

Capsules, synovial, 122.

», of cartilage, 18.
Caracal, 426.
Carbonic acid (exchange of), 220.
Cardia, 178.
Cardiac plexus, 284.
Cardinal veins, 347.
Carnivora, 469, 471.

sh characters of, 473.

- component groups of, 474.
Carotid arteries, 208.

» canal, 83.
a foramen, 476.

Carpus, 96.
Carthusian cat, 6.
Cartilage, 18.

b development of, 330.
Cartilages (costal), 50, 52.

b of larynx, 227.

a of nose, 286.

Cartilaginous cranium (formation of), 337.

sis skeleton (backbone), 333.

Cat, Angora, 6.
», Carthusian, 6.

», gestation of, 8.

», ts place in nature, 440, 4938.

sp yeMlalayy av:

5G aber? 7.

», origin of the word, 2.

», Persian, 6.

», regions of the world, 497

»» Siamese, 6.

55. beeth*of, 27.

», tortoiseshell, 6.

whiskers of, 24.

Categories of vertebra, 36.
Catless regions, 496.
Cat-mind, 386.
Catolynx, 404.
Cat’s ancestors, viverrine, 512.

», antiquity, 3.

», body, 14 ; its chemical constitution,

12 ; diagram of, 16.

s, emotions, 368.

Se) MEYER TO:

», feet, pads.of, 25.

»» genus (its position), 489

», language, 371.

» Origin, 519.

», pedigree, 517, 518.

»» place in nature, 440.

», psychical powers, 366.

quasi-intelligence, 367.

Cats born with stump- -tails, if
,, colours of, 5.

», extinct lends 432.

», in Egypt, 3.

», in the Middle Ages, 2

», influences of environment on, 8.
,, number of kinds, 431.

», of Isle of Man, 7.

,, of Mombas, 7.

», of Paraguay, 7.

CHEETAH.

Cats, their food, 8.
Cattle, 467.

Cauda equina, 259.
Caudal artery, 213.
»» vein, 216,

a vertebre, 46,
of Malay cat, 46, 47.
E of Manx cat, 46.
Caudo- -cavernosus, 144.

Causal action of sensations, 383.
Cause of psychogenesis, 526.
Causes, 526, 529.
sb (a knowledge of, sane constitutes
science, 530.
Cavities of heart, 201.
is of skull, 85.
Cavity of abdomen, 176.
Cells, 17 (note).
», Of liver, 188.
»» Merve, 255.
Cement, 31.
Be formation of, 344.
Centetes, 468.
Centipedes, 450.
Centripetal and centrifugal fibres, 308.
Centrum, 35.
Cephalo-humeral, 147.
Cerato-hyal, 78.
Cerebellar fossa of skull, 83.
Cerebellum, 259, 262.
its functions, 311.
Cerebral hemispheres, 260.
Cerebrum, 259.
its functions, 312.
Cervical glands, 218.

39.0 Merves; 27 4:

vo, Plexus are

»,» vertebre, 40.

f ossification of, 334.
Cervicalis ascendens, 138.
Cervix of tooth, 27.
Cestum Veneris, 450.
Cetacea, 467, 471.
Change of colour of blood, 208.
Changes after death, 522.
Characters of cat (the most general), 440.

9? 39

a of cat’s-order, 473.
3 of cat’s sub-order, 489.
an of cat as a vertebrate, 454.

Characters distinguishing cat from crea-
tures devoid of life, 441, 445; from
plants, 448 ; from Didelphia, 471,

Characters distinguishing cat’s class from
fishes, 458; from Batrachians, 460 ;
from Branchiata, 461; from reptiles,
462; from birds, 465; from Mono-
condyla, 466; from Ornithodelphia,
470; from Hyzenide, 488; from Vi-
verride, 488 : from Cryptoproctide, 489.

Chati, 409.

Chaus, 420.

Cheek ligaments, 54.

Cheetah, 427.

INDEX. 535

CHEIROPTERA. CORPUSCLES.
Cheiroptera, 468, 472. Composition of cat’s body and its systems
Chemical constitution of cat’s body, 12. of parts and organs, 374.
Chevron bones, 47. sis of organs, 375.
Chevrotains, 467. * of tissues, 375.
Chiasma (of the nerves), 270. Compressor naris, 131,
Chinese cat, 414. Ps urethre, 144.
Choanoid muscle, 132. Concha, 295.
Chorda tympani, 274. Conditions of nervous activity, 307.
Chorio capillaris, 291. Condyle (of mandible), 60, 77.
Chorion, 323. Condyles of femur, 108.
Choroid, 290. fs of tibia, 110.
a plexus, 266. Cones and rods, 292, 293.
Chyle, 181. Coni vasculosi, 244.
Chyme, 180. Conical papille, 172.
Cilia (vibratile), 25, 175. Conjunctiva, 288, 289.
Ciliary artery, 208. Connective tissue, 16, 17.
sy7 muscle, 292. . os », development of, 330.
33 processes, 290. Consciousness and automatism, 384.
Ciliated epithelium, 25, 175. Consentience, 378.
Cingulum, 28. Constrictors of pharynx, 185.
Circle of Willis, 209. Continuity (law of), 443.
Circulation (organs of), 192. Contractility, 127. “
3 its course, 203 Contraction (muscular), 124, 126.
as in kidney, 234. Conus arteriosus, 205.
ge in liver, 187. Convolutions, 261, 268.
Circumduction, 128. Coordinating system, 258.
Circumflex artery, 210. Coordination of psychical powers, 374.
oe nerves, 278, 279. Coraco-brachialis, 148.
Circumflexus paiati, 135. », Clavicular ligament, 100.
Circumvallate papille, 172. Coracoid process, 90.
Civet cats, 469, 475, 481. Coral animals, 450.
Classes of vertebrata, 455. Corde tendinex, 204.
_ Classification of muscles, 130. Cord, spermatic, 243, 245.
at zoological, 449, Cords (vocal), 227, 229.
Clavicle, 90. », Of sympathetic, 283
Claws, how retracted and protruded, 102. | Corium, 22.
Cleido-mastoid, 134. Cornea, 290.
Clinoid processes, 69, 71. Cornua of lateral ventricles, 267.
Clitoris, 246. Coronal suture, 60.
Cloaca, 348. Coronary arteries, 206.
Clouded tiger, 398. ue artery of stomach, 211.
Coagulation, 193. et vein, 205.
Coati-mundis, 474. Coronoid fossa, 93.
| Cochlea, 299. as process of mandible, 77; of
. Cochlear part of labyrinth, 301. ulna, 96.
a " nerve, 302. Corpora Aurantii, 204.
; Cod (structure of), 456. »» cavernosa, 242.
| Ceelentera, 450, 453. »» Mmammillaria, 263.
. Cenurus, 509. », Striata, 268 ; their functions, 311.
Colloids, 167. » quadrigemina, 262.
Colocollo, 413. iy Ln their function, 311.
Colon, 182. Corpus albicans, 263.
. Colours of cats, 5. 53) Gallosum,: 261.
Columne carne, 204. a on development of, 359.

Columnar epithelium, 26.

» geniculatum, 262.
Combustion of tissues, 222.

», Highmorianum, 243.

Commissures of spinal cord, 259. », luteum, 251.

q Common jungle cat, 420. », spongiosum, 242.

| Comparative anatomy, 10. .trapezoideum, 263.
Complemental air, 226. Corpuscles of connective tissue, 16,

Complete joints, 121,
- Complexus, 135.
Composition of air, 221.

as of bone, 19.
sg of blood, 194.
vy lymph, 195.

See
.
7

536 INDEX.

CORPUSCLES.

Corpuscles, Malpighian, 233.
i nerve, 255.
Correspondences between skeleton of fore
and hind limbs, 119,
Corti (organ of), 302.
Cosmos (the), 529.
Coste, 50.
Costal cartilages, 50, 52.
», ligaments, 55.
>» .. Surfaces, 87:
Cotyloid cavity, 106.
» . digament, 116:
Coughing, 226.
Course of ‘blood through heart, 203, 204.
Cowper’s glands, 248.
Crabs, 450.
Cranial bones (formation of), 338.
» herves, 269; their... functions,
309 ; ; development of, 361.
Cranium, 57.
Creation, 527, 528.
Creodonta, 504.
iH their affinities, 515.
Cribriform plate, 71.
‘3 plane of, 85.
Cricoid cartilage, 227,
Crocodiles, 462.
Crossarchus, 481.
Crucial ligaments, 117
» sulcus, 269.
Crura of olfactory lobes, 264, 270.
», Of stapes, 298.
», cerebri, 260, 263.
Crureus, 159.
Cryptoprocta, 518.
Cryptoproctide, 475, 483, 488.
Crystalline lens, 293,
Crystalloids, 167.
Cuboid bone, 115.
Cumulus, 250.
Cuneiform bones, 96, 115.
Cuttlefishes, 450, 452.
Cycles of change, 442.
Cynictis, 481.
Cynodictis, 507, 514, 518,
Cynodon, 506, 514, 518.
Cynelurus, 513, 518.
Fs. jubata, 427.
> lanea, 429.
Cynogale, 481.
Cynoidea, 474, 479.
Cystic duct, 186.
», fissure, 186.
Cysticercus cellulosa, 509.

Dartos, 248.

Dasyures, 468.

Dasyurus, 518.

David, Peére, 6.

Dead bodies, 385.

Death (changes of decomposition), 522.
», stiffening, 128.

DEVELOPMENT,

Decidua, 327.

Deciduous dentition, 29.
Deer, 467.

Definition of an organism, 9.
Deltoid, 147.

Delusive feelings, 308.
Dental formula, 30.

»> ‘nerves, 273.
Dentine, 31.

a formation of, 344.
Dentition (milk), 29
Depressor muscles, 129.
Derivative creation, 527.
Dermis, 21, 22.
Descending aorta, 208.

HS colour, 182.
Development, 11, 317.

a and psychology, 386.

a of alimentary canal, 341.’

+5 of anus, 343.

ay of arteries, 346.

By of auditory ossicles, 339.

i of axial skeleton, 332.

- of blood, 331.

- of blood-vessels, 345,

a of bone, 331.

i of brain, 357.

a of cartilage, 330.

a of cartilages of vertebral
column, 333.

5 of cartilaginous cranium,
337.

ey of cement, 344.

Hi, of connective tissue, 330.

a of cranial bones, 338.

i of cranial nerves, 361.

os of dentine, 344.

ne of ear, 362.

A of elastic tissue, 330.

3 of enamel, 344.

4 of epithelial tissue, 331

— of eye, 361.

‘ of Graafian follicles, 355.

33 of heart, 345

gi of jaws, 336.

o of kidneys, 351.

ae of larynx, 350.

FP of limbs, 339.

ft of liver, 344.

is. of lungs, 349.

fe of lymphatic system, 349.

me of mouth, 342.

‘ of muscles, 341.

ra of muscular tissue, 331.

mf of nares, 337.

Bs of nervous system, 355.

- of nervotis tissue, 331.

of nose, 363.

i of organs, 329.

- of ova, 354.

" of ovary, 352.

5 of pancreas, 344.

ay of penis, 352.

INDEX. 537

DEVELOPMENT.

Development of peritoneal cavity, 322.

bes of peritoneum, 345.

a of salivary glands, 344.

i of skull, 335.

a3 of species, 512.

- of spermatozoa, 245.

5 of spinal marrow, 356.

fy . of spleen, 350.

ae of suprarenal corpuscles,
351.

$5 of testes, 352.

re of the teeth, 343.

i of thymus gland, 350.

im of thyroid body, 350.

‘5 of tissues, 329,

35 of urinary organs, 350.

a of vagina and uterus, 352.

= of veins, 346.

of visceral clefts, 30D.
Developmental changes before impregna-
tion, 317.
their principle, 387.
Diagram of cat’s body, 16.
Dialysis, 167.
Diaphragm, 141.
Diarthroses, 121.
Diastema, 28.
Dicyema, 450
Didelphia, 469.
Didelphys, 504, 518.
Didymictis, 506.
Difference between skeleton of fore and
hind limbs, 119.
sh between muscles of fore and
hind limbs, 163.
Differentiation, 329.
Different kinds of cats, 390.
an possible modes of evolution,
519:
Diffusion of air in lungs, 229.
Digastric muscles, 128, 133.
Digestion, 167.
Digitigrade progression, 129.
Digits, maximum of muscles to, in fore-
paw, 153.
y» maximum number of muscles to,
in hind-paw, 163.
Dinictis, 435, 502, 518.
Dinotheria, 467.
Diploe, 86.
Direction of muscles, 153.
Discus proligerus, 250.
Diseases of cat, 511.
Distinction between erystalloids and
colloids, 167.
Distoma lanceolatum, 509.
Division of nervous system, 253.
Dogs, 468, 474.
Dolphins, 467.
Domestic cat, breeds of, 5.
Dorsal aorta, 208.
», artery of foot, 214.
»» cominon ligament, 53.

ENAMEL.

Dorsal nerves, 277, 281.
j, plates, 321.
y> Spinal nerves, 277.
»5 vertebra, 36, 37.

a. VER tebrie (tenth and eleventh), 3
Dorso-epitrochlear (external), 137.
5» epitrochlear (inner), 137.

Double hinge-joints, 123.
Dromatherium, 504.
Duct (Gaertner’s), 250.
55 . thoracic, 218.
Ductless glands, 237.
Ducts of liver, 186.
»» lymphatic, 218.
» pancreatic, 183.
oh Mtenson’s.. 172;
» Wharton’s, 173:
Ductus arteriosus, 206, 346.
», communis choledochus, 186.
»5 Cuvieri, 347.
», omphalo-entericus, 327.
», venosus (fissure of), 185._
Dugong, 467.
Duodenum, 181.
Dura mater, 256, 261.

Ear, development of, 362.
», external, 295.
», its middle part, 297.
»» muscles, 131.
Ear and eye, analogies of, 303.
Earthworms, 450.
Echidna, 469.
Echinoderma, 450.
Ecteron, 21.
Ecto-cuneiform, 115.
Ectoderm, 453
Ectodermic cells, 319.
Edentata, 468, 471.
Effects of bile on food, 188.
Efficient causes, 527, 529.
Egyptian cat, 5, 419.
Egyptians and the eat, 3.
Eighth caudal vertebra, 47.
ot 6merve, 274.
Elastic ligaments, 123.
= P of claw, 102.
oo.) > tissues 17.
», development of, 330.
Elasticity of lungs, 224.
Electricity and nervous activity, 306.
Elementary substances of body, 166.
Elements (of nervous tissue), 254.
Elevator muscles, 129.
Eleventh dorsal vertebra, 32.
so) © Merve, 275.
Embryo (its first appearance), 320.
Embryonal area, 320.
Emotions of cat, 368.
Enamel, 31, 32.
», formation of, 344.
organ, 32, 343.

39

538 INDEX.

ENARTHRODIA.

Enarthrodia, 122.
Encephalon, 259.
Encystment of parasites, 509.
End organs, 255.

Enderon, 21.

Endoderm, 453.

Endodermic cells, 319.
Endolymph, 301.

Endoplast, 330. '
Endo-skeletal muscles, 130.

», Skeleton, 21.
Endosmosis, 167.
Ensiform process, 50.
Enteropneusta, 450.
Ento-cuneiform, 115.

», tympanic, 65.
Environment, 494.

Eocene strata, 502.
Ependyma, 260.
Epiblastic cells, 319.
Epidermis, 21.
Epididymis, 243, 244.
Epigastric artery, 213.

- plexus, 284.
Epiglottis, 228.
Epi-hyal, 78.
Epiotic, 69.
Epiphyses, 20, 21.

a vertebral, 334.
Epithelial tissue, 21.

development of, 331.
Epithelium, 21, 26.
_ ciliated, LiDs
Equivalence of male and female parts in
impregnation, 318.

Erectile tissue, 242.
Erector spine, 138.
Essential respiratory organs, 223.
Eternity of archetypal ideals, 528.
Ethiopian region, 498.
Ethmoid, 71.
Ethmoidal artery, 208.
Ethmo-turbinal, 71.

»» vomerine plate, 337.
Eusmilus, 437, 491, 503, 518.
Eustachian tube, 66, 298.
Evolution, 11, 512, 521.

a its possible modes, 519.

2 of Macherodus, 522.
Examples of orders of levers, 130.
Exchange (gaseous), 220.
Excito-motor action, 310.

Excretin, 188.

Exemplar causes, 529.

Existing cats, 430.

Ex-occipital, 61.

Exo-skeletal muscles, 130.
Exo-skeleton, 21.

Exosmosis, 167.

Experience as to origin of new forms, 521.

9 and origin of life, 524.

as to modes of origin, 524.
Extensor brevis digitorum, 160.

FELIS.

Extensor carpi ulnaris, 152.

», communis digitorum, 151.

sy andicis, 4152.

», longus ‘digitorum pedis, 159.

fs metacarpi pollicis, 152.

»» Mminimi digiti, 151.

»» muscles, 128.

secundi internodii pollicis, 152.
Extensores carpi radialis, 151.
External annular ligament (of hind-paw),
62.

», auditory meatus, 296.
Ps cutaneous nerve, 281, 282.
», dorso-epitrochlear, 137.
53 ear, 295.
9, iliac artery, 213.
»» Malleolus, 112.
», Oblique, 141.
», and internal respiration, 221;
sensations, 313.
influences on cats, 8.
Extinct cats, 432.
Eye, 288.
», recti muscle of, 132.
», as an optical instrument, 294.
», development of, 361.
,, and ear (analogies of ), 303.
Eyeball, 289.
Eyelids, 288.
», functions of, 294.
Eyes of cats, 5.
Eyra, 412.

FAcIAL artery, 208.

55: Glande lis:

», herve, 274.
Facts anatomical and pathological, 377.
Falciform ligament. of liver, 185, Tone
Fallopian tubes, 247.
False ribs, 50.

» vertebre, 36.

», vocal cords, 229.
Falx cerebri, 256, 261.
Fascia, palmar, 149.

», Spermatic, 243.

», superficial, 143.

», transversalis, 143,
Fascie, 124.

Fat, 18.

Fauces, 170.

Feathered bird’s feet, 377.
Feelings, 304.

Felide, 475, 487.

Felis, 518.

Felis aurata, 401.

», vadia, 419,

», bengalensis, 403.

», borealis, 424.

», orachyurus, 399.

5, caligata, 419.

5, canadensis, 425.

», caracal, 426.

», catws, 4, 420.

FELIS.

Felis caudatus, 421.

celidogaster, 406.
Chaus, 420.
chinensis, 414.
christoli, 432.
colocollo, 413.
concolor, 397.
Duvancelli, 404.
erythrotis, 420.
euptilura, 416.
Eyra, 412.
Fonterrti, 394.
grisea, 408.
guigna, 410.
guttula, 410.
Herschelti, 415.
tsabellina, 426.
javanensis, 416.
Jerdoni, 415.
jubata, 427.
lanea, 429.

leo, 392.
lupulinus, 426.
lyncus, 424,
macrocelis, 398.
macroura, 409.
maculata, 425.
maniculata, 5.
Manul, 422.
marmorata, 404,
megalotis, 417.
melanura, 408.
microtis, 417.
minuta, 415.
mitis, 409.
neglecta, 407.
onca, 397.
ornata, 420.
pajeros, 423.
pardalis, 408.
pardina, 426.
pardinoides, 411.
pardochroa, 403.
pardoides, 408.
pardus, 394.
picta, 408.
planiceps, 417.
rubiginosa, 413.
rufa, 425.
rutila, 406.
scripta, 400.
senegalensis, 406, sig
serval, 406.
servalina, 408.
Shawiana, 421.
spelea, 432, 502.
tigrina, 409.
tigris, 393.
torquata, 420.
tristis, 400.
Tulliana, 396.
uncia, 395.
viverrina, 401.

INDEX. 539

FOLDS.

felis yaguarondi, 412.
Felting, 23.
Female generative organs, 245.
Femoral artery, 213.
ye wemage 245.
Femur, 107.
Fenestra ovalis, 68, 297.
5 rotunda, 68, 298.
Fenestration, 329.
Fibres (nerve), 254.
Fibrille (muscular), 126.
Fibrin, 193.
5, muscle, 125.
Fibrc-cartilage, 18.
Fibula, 112.
Fifth caudal vertebra, 47.
9, cervical vertebra, 40.
»; dorsal vertebra, 37.
», lumbar vertebra, 39, 40.
», pair of nerves, 271.
», ventricle, 266, 267.
*3 (natureandorigin of), 359.
Filaments (spermatic), 245.
Filum terminale, 257.
Fimbrie, 247.
Final causes, 527.
First appearance of embryo, 320; of
notochord, 321.
»» pair of nerves, 270.
Seo zkDy Oy
», segmentation nucleus, 318.
», visceral arch, 337.
Fishing cat, 401.
Fissura Glaseri, 65.
Fissure (portal), 185.
», of ductus venosus, 185.
umbilical, 185.
great longitudinal, 261.
of cerebrum, 261.
Fissures of liv er, 185.
oe Ok spinal cord, 258.
Flagellate animals, 450.
Flat-headed cat, 417.
flattened papille, 172.
Flea of the cat, 510.
Flexor brevis digitorum, 161.
», brevis minimi digiti, 152.
»» carpi radialis, 149.
», carpi ulnaris, 151.
longus digitorum, 161.
», longus hallucis, 161.
» pertorans of fore-paw, 150
perforans of hind-paw, 161.
perforatus of fore paw, 150.
perforatus of hind paw, 161.
profundus digitorum, 151).
sublimis digitorum, 150.
muscles, 128.
Floating rib, 51.
Fluids passing through membranes, 167.
Flukes, 450, 509.
Foetus, 328.
Folds of mucous membrane, 27.

540

FOLLICLES.

Follicles (Graafian), 249.
Fontaneir’s spotted cat, 400.
Food, 165.

po IGE Cats, 8.

Foramen anterior condyloid, 62.

», anterior palatine, 74.

», carotid, 476.

3. meison 74

>, inferior dental, 77.

», infra-orbital, 73.

>» lacerum jugulare, 62.

», lacerum posterius, 62.

>», Magnum, 61.

3, magnum (plane of), 85.

so), paRLeH a gene

o5. .Obturator, 1040907!

53 Op biesog ls

33° Ovale, 70.

», ovale (of heart), 346.

», post-glenoid, 67.

», posterior palatine, 76.

3, rotundum, 70.

»» Spheno-palatine, 76.

3, Stylo-mastoid, 65.

supra- -condyloid, Ol:
Foramen of Monro, 266, 267.

ive OF Winslow, 190,
Foramina (inter-vertebral), 36.

x sacral, 45.

Force, internal, 525.

», intra-organic, 380.
Fore-arm (muscles of), 149.
Fore-limb (muscles of), 145.

A nerves of, 278.
Fore-paw (muscles of), 152.
Fore and hind limbs (differences and

correspondences between their skele-

tons), 119.

Form of peritoneum, 189.
Forme transeuntes, 389.
Formula (dental), 30
Fornix, 26.

» development of, 359.
Fossa, anconeal, 93.

», coronoid, 93.

»» iliac, 106,

», inter-condyloid, 109

»» mesopterygoid, 70.

», olecranal, 93.

3) OValis, 20a

»» pterygoid, 70.

trochanteric, 107.
Fosse of nose, 286.
Fossil cats, 432, 489, 502.
Fossils, 501.
Fourth caudal vertebra, 47.

», pair of nerves, 271.

», ventricle, 265.
Foussa (the), 483.
Frenum lingue, 172.
Frog (structure of ), 459.
Frontal bone, 63.

», lobe, 264.

INDEX.

GENERAL,

Frontal sinuses, 64, 86.
Fronto-auricular, 131.
Fulcra, 129.

Functions, 10.

5a of corpora striata, 311.
9 of corpora quadrigemina, 311.
3 of cranial nerves, 309.

5 of eyelids, 294.

5 of kidney, 234.

of large intestine, 183.

at of liver, 188.

oe of medulla oblongata, 310.

55 of muscular tissue, 126.
5 of muscles, 129.
s of nervous system, 304.

" of optic thalami, 311.
a of ovary, 250.

Si of pancreas, 184.

5 of parts of internal ear, 303.
“ of respiration, 220.

~ of saliva, 174.

Me of small intestine, 181.

a of spinal nerves, 307.

Ay of spleen, 238.
et of stomach, 179.
oe of sympathetic system, 312.
es of the cerebellum, 311.
oy of the cerebrum, 312.
43 of the spinal cord, 309.
of the teeth, 171.
Fundamental similarities of male and
female sexual organs, 354.
Fungiform papillee, 172.
Furculum, 462.

GAERTNER’S duct, 250.
Galecynus, 507, 514, 518.
Gall-bladder, 186.
Ganglia (semi-lunar), 284.
Gangliated sympathetic cords, 283.
Ganglion (Gasserian), 272.
>» impar, 284.
»» Meckel’s, 273.
»» Spheno- palatine, 273.
Gaseous exchange, 220.
Gases (poisonous), 221.
Gasserian ganglia, 272.
Gastric juice, 179.
»» merves, 275.
Gastrocnemius, 160.
Gastro-colic omentum, 190.
Gastrodisc, 320.
Gastro-hepatic omentum, 190.
Gastro-splenic omentum, 190.
Gelatine, 12.
Gelatinoid substances, 166.
Gemelli, 156.
Genealogy of cat, 517, 518.
General coloration of F elide, 430.
»» geographical regions, 497.
,, view of pectoral limb’s skeleton,
102 ; of pelvic limb’s skeleton,
119 ; ; of peritoneum, 191.

INDEX. 541

GENERALIZED.

Generalized forms, 490.

oA view of skull, 87,
Generation of heat, 222.
Génerative organs, 240.

BA »» Imale, 241.
», female, 245.

Generic names, 392.
Genets, 481.
Genio-hyoglossus, 134.
Genio-hyoid, 134.
Genito-crural nerve, 281, 282.
Genu (of corpus caliosum), 265.
Geoffroy’s cat, 410.

Geographical distribution of wild cat, 3.

is relations of cats, 495.
Geography, organic, 11.
Geological facts, 501.
Gephyrea, 450.

Germ area, 320.
Germ-cell and sperm-cell, 318.
Germinal vesicle and spot, 250.
Gestation, 247, 328.
- of cats, 8.
Gills, 456.
Ginglyform joints, 122.
Girattes, 467, 507.
Giraldes (organ of), 244.
Glands (Harderian), 289.
» axillary, 21s.
», Of Bertholin, 246.
» Bruner’s, 181.
a, Buccal, 174.
» cervical, 218.
», Cowper's, 243.
», ductless, 237.
oa. daetal, 173.
», of small intestine, 181.
we dabial,. 1:70;
» lachrymal, 289.
,, of Lieberkiihn, 181.
» lymphatic, 198, 218.
ys Meibomian, 288.
>, mesenteric, 218.
», parotid, 172.
epepiic, 29,
», pineal, 266.
»» prostate, 242.
4. Salivary,' 172.
», submaxillary, 173.
», (their nature) 230.
y5 OF thich,.2ts.
» thyroid, 237.
», tracheal, 218.
zygomatic, 173.
Glenoid ligament, 100.
EF surface, 58.
Globus major and minor, 243.
Clomerulus, 234.
Glosso-pharyngeal nerve, 274.
Glottis, 226.
Gluteal nerves, 251, 282.
Gluteus maximus, 154.
a sedis, 155;

ey

HIERARCHY.

Gluteus minimus, 156.
» quartus, 156.
Glutton (the), 475.
Glycogen, 188.
Goats, 467.
God implied in nature, 527,
Golden-haired cat, 406.
Gomphosis, 121.
Graatian follicles, 249.
* development of, 355.

Gracilis, 158.
Granular layers, 293.
Great blood-vessels, 201.

», longitudinal fissure, 261.

»» omentum, 176, 190.

», sciatic nerve, 282.
Gregarinida, 450.
Grey African cat, 407.
Grey nerve fibres, 255.

»» nervous matter, 256.
Groups composing Carnivora, 474.

», (zoological), what they really

are, 520
Growths of bone, 20.
Gullet, 175.

Gulo, 475.

Gustatory bulbs, 285.
He cells, 285.
Se nerve, 273.
ss pores, 286.

Gymnura, 468, 518.

Gyri, 261, 268.

Harr, 22.

Hallux, 115.

Hamular process, 70.
Harderian gland, 289.
Hares, 469.

Haversian canals, 19.
Head (muscles of), 131.

», skeleton of, 56.

,, and tail folds of embryo, 322.

,, and trunk (skeleton of), 84.
Hearing, 315

Be organ of, 295.
Heart, 199.

», formation of, 345.
Heat, 494.

» generation, 222.
Hedgehog, 468.
Helicotrema, 301.
Hemispheres of brain, 260.
Hemistoma cordatum, 509.
Hepatic artery, 187, 211.

oe eels. 188.

iar encks; 186,

a veins, 187.
Herpestes, 481, 482.
Hexicology, 11.

of cat, 494,
Hiatus Fallopii, 66.
Hierarchy of functions, 375.
- of parts, 374.

il asin Oa “

542
HIND.
Hind foot (articulations and ligaments
of), 118
», leg (ligaments and articulations
of), 116.

Hind limb (muscles of), 154.

Hinge joints, 122.

Hip (muscles of), 154.

Hippocampal gyrus, 268.

Hippocampus major, 267.

Hippopotamus, 467.

Histology, 9.

Hoplophoneus, 433, 502, 518.

Horizontal ramus, 77.

Horns of spinal cord, 259.

Horses, 467.

Human mental powers, 372.

Humerus, 90.

Humour (aqueous), 294.
vitreous, 293.

Hunting leopard, 427.

Hyzenaretos, 507, 514, 518.

Hyenictis, 514.

Hyenide, 475, 483, 488, 518.

Hyenodon, 506, 514, 518. .

Hyaline cartilage, 18.

Hydatid of Morgagni, 244.

Hydra, 450.

Hymen, 246.

Hyoglossus, 134.

Hyoid, 57, 77.

Hyoidean cornua, 77.

Hypapophysial parts, 39, 44.

Hyperapophyses, 43.

Hypoblastic cells, 319.

Hypogastric artery, 213.

plexus, 284.

Hypoglossal nerve, 275.

Hypozoa, 450, 454.

Hypsiprymnus, 504.

Hyrax, 46/7.

IcHNEUMONS, 481.
Ictitherium, 507, 513, 518.
Idealism, 385.
Ideas (prototypal or archetypal), 528.
Tleum 180.
Tleo-czcal valve, 183.
Iliac artery, 212.

», fossa, 106.

55 Wer, - 216;
Tliacus, 156.
Jlium, 105.
llio-coccygeus, 143.
Ilio-hypogastric nerve, 281, 282.
Tlio-inguinal nerve, 281, 282.
Immaterial realities, 385.

“ and material substances, 378.
Immovable joints, 120.
Imperfect joints, 121.

Incisor foramen, 74.
Incisors, 28.

Ineus, 298.

Index (of forepaw), 99.

INDEX.

INTER-TRANSVERSE.

Indian region, 498.
» Wild cat, 420.
Indifferent tissue, 330.
Individual, the physiology of, 11 .
Individuation, principle of, 376.
Inferior dental foramen, ae
ah ayo. herve, 273..
», Jlaterus gyrus, 269.
»» maxillary nerve, 273.
Infra-coecygeus, 148.
», orbital artery, 208 ;
»» spinatus, 148
Infundibulum, 264.
Infusoria, 450.
Initial developmental changes, 318,
Innate polar force, 377.
Inner dorso- -epitrochlear, 137.
Innominate artery, 207.
Sy veins, 215.
Innominatum (os), 104.
Inorganic matter cannot support the
cat’ s life, 166.
Insectivora, 468, 472, 518.
Insectivorous nature of primitive mam-
mals, 516.
Insects, 450.
Insertion (muscular), 128.
Inside of cranium, 82.
Instincts of cat, 368.
Intellect (puts order in sense), 528.
Intellectual powers, 372
Intelligence (Divine), 530.
Interarticular cartilages, 122.
Intercondyloid fossa, 109.
Intercostal artery, 209.
os vein, 217.
Intercostals, 140.
Interlobular veins, 188.
Intermetacarpal ligament, 102.
Internal annular ligament (of hind paw),

nerve, 73.

162.
3 carotid, 208.
Ru cutaneous nerve, 278.

An force, 525.

», heat, 222.

%s iliac artery, 213.

a malleolus, 112.

us mammary artery, 209.

a oblique, 142.

and external respiration, 221,

Internuclear layer, 293.
Inter-ossei of fore-paw, 152.

- of hind-paw, 162.
Inter-osseous artery, 210.
Inter-parietal, 62.
Inter-relations of animals, 508.
Inter-septal zone, 126.
Inter-spinales, 139.
Inter-spinous ligaments, 54.
Inter-tarsal joint, 461.
Inter-transversales, 139.
Inter-transversaril caude, 148.
Inter-transverse ligaments, 54.

INDEX.

INTER-TROCHANTERIC.

Inter-trochanteric ridge, 107
Inter-vertebral discs, 52.

foramina, 36.
substance, 36.

99
bP)

es, 180.

‘Intestine (large), 182.0) &
Intra-lobular veins, 188.
Intra-organic force, 380.
‘Inter-susception, 167.
Involuntary motions, 124.
Ireland and the wild cat, 3.
Tvts; 291.

Irritability, 127.

Ischiatic notches, 107.
Ischio-cavernosus, 144.
Ischio-coccygeus, 143.
Ischium, 105.

Isle of Man, cats of, 7.
Isthmus faucium, 170.
Itch-insect of cat, 510.

Iter et tertio ad quartum ventriculum, 267.

JACOBSON’S membrane, 292.
+ organ, 288.
Jaguar, 397.
Javan cat, 416.
Jaws (formation of ), 336
Jejunum, 180.
Jelly-fishes, 450, 453.
Jerboas, 469.
Jerdon cat, 415.
Joint oil, 121.
Joints, 120.
Jugular foramen, 62,
y veins; 215,
Juice (gastric), 179.
», intestinal, 181.
»» pancreatic, 184.
Jungle cats, 420.

KANGAROOS, 468.
Kidney (its function), 234.
Kidneys, 232.
if development of, 351.

Kinds (what they are), 390.

», of food needed, 165.

», of language, 372.
Kinkajous, 474.
Knee-joint, 118.
Knowledge and natural selection, 384.
Kreatin, 125, 235.
Kreatinine, 125.

Lapia, 246.
Labial glands, 170.
Labyrinth (bony), 299.

ie membranous, 301.
Labyrinthodonta, 459.
Lacerta, 461.
Lachrymal bones, 75.

ash gland, 289.
Lacteals, 18], 218.
Lacune, 19.

LIGAMENTS.

Lambdoidal ridge, 61.
suture, 60.
Lamina spiralis, 299, 300.
Laminz dorsales, 392.
», ventrales, 322.
Lampshells, 450.
Lancelet, 455.
Language (its six kinds), 372,
Large-eared cat, 417.
Large intestine, 182.
Laryngeal nerves, 275.
Larynx, 223, 226.
i formation of, 350.
a its ligaments, 228.
»» its muscles, 229.
Lateral ethmoid, 71. -
» ginglymus, 122.
», masses of sacrum, 46,
»» ventricles, 265, 267.
Latissimus dorsi, 137.
Law of continuity, 443,
Leeches, 450.
Left auricle, 205.
“a ventricle, 206.
Lemurs, 468.
Lens, 293.
Leopard, 394.
Leopard cat, 403.
Leopardus Hernandesii, 397.
Lepidosiren, 458.
Lesser sciatic nerve, 282.
» omentum, 190.
Levator anguli scapule, 145.
” ao) OFFS: Lois
» caude externus, 143.
sis se» witernus, 143;
» Clavicule, 148.
jen escroul, £43.
», labii superioris, 131.
oo Dalati 1S;
palpebre, 133, 288.
Levatores costarum, 140.
Levers, 129.
es orders of, 130.
Lewes (Mr.), 383, 384.
Lieberkiihn (glands of ), 181.

Life (its origin experienced), 524,

Ligamenta subflava, 53.

Ligament (broad, of liver), 185.
op alertorm, 1385, 191,
5. Loupart’s, 141:

», round, of liver, 185, 191.

Ligaments, 18.
of ankle-joint, 118.

Y cotyloid, 116.

5 crucial, 117.

of ear ossicles, 299.
elastic, 123.

of elbow-joint, 101.
ie of hind-foot, 118.
a of hind-leg, 116.

543

annular of hind-paw, 162.
of atlas and axis, 54.

544 INDEX.

LIGAMENTS.

Ligaments of larynx, 228.
a of pectoral limb, 100.
< of pelvic girdle, 116.
a2 of ribs, 55.
ee of shoulder, 100.
‘is of skull, 86.
bs of spine, 52.
* of uterus, 247.
of wrist, 102.
Ligamentum denticulatum, 257.
& nuche, 54, 123.
mn patella, ie
am teres, 116.
fies aye gplt dor, 107:
Light, 494.
Limbs (development of ), 339.
» muscles of, 145. ©
pee fits skeleton of, 89.
Limb-bones (ossification of), 340.

», muscles (serial homologies of), 163.
skeleton (its serial homologies), 120.

9
Limnofelis, 437,
Linea aspera, 107.
Lingual artery, 208.
Lingula sphenoidalis, 70.
Lining of small intestine, 181.
», of stomach, 179.
Lion, 392.
Lion’s pelvis (diseased), 377.
Lips, 170.
Liquor sanguinis, 194.
Liver, 184.
cells, 188.
formation of, 344.
its function, 188.
its minute structure, 187.
Living cats, 430.
Lizard (structure of), 461.
Llamas, 467.
Lobes of cerebrum, 260, 264.
» of lungs, 224.
», olfactory, 260.
Lobsters, 450, 452.
Lobules of liver, 185, 187.
Localization of sensations, 308.
Locus perforatus anterior, 264, 265.
Locus perforatus posterior, 364,
Longissimus dorsi, 138.
Long thoracic artéry, 209.
Longus colli, 135.
Louse of cat, 510.
Lower (tubercle of), 205.
Lumbar nerves, 277, 281.
plexus, 281.
veins, 216.

» vertebree, 39.
Lumbo-sacral nerve, 281.
Lumbricales (of fore-paw), 151.
of hind-paw, 161.

9?

399
3)

Lungs, 224.
», their function, 220.
», development of, 349.

Lutrictis, 507, 514, 518.

MATTER.

Lymph, 195.
Lymphatic ducts, 218.

is glands, 218.

a system (development of),349
Lymphaties, 198, 217.
Lynceus, 424.

», lupulinus, 426.

Lynx, 424.
Lyra, 265, 268. . 3
Lytta, 171.

Macheerodus, 432, 491, 503, 518.
and evolution, 522.
Machines (as distinct from or ganisms),
382.
Magnum (os), 97.
Malar bone, 74.
»» process (of maxilla), 73.
Malay cat, 7.
»> 9, caudal of vertebrae, 46, 47.
Male organs, 241.
Malleoli, 112.
Malleus, 298.
aN origin of, 339.
Malpighian corpuscles, 233.
as of spleen, 238.
Mammalia, 455.
Mammalian groups, 466.
Mamunals (oldest tertiary), 514.
ee secondary, 516.
Mammary glands, 239.
Man, 468.
Manatee, 467.
Mandible, 57, 77.
sg ligaments of, 87.
Mandibular symphysis, 77.
Mangue (the), 481.
Manis, 468.
Manubrium, 50. : |
of malleus, 298.

Manul, 422.
Manx cat, 7.
>> 955 caudal vertebre, 46. :
Marbled tiger-cat, 404.
Margay, 409.
Markings of cats, 508.
Marrow, 18.
es spinal, 257.
Marsupial characters of Creodonta, 515.
nature of primitive mammals ?
515.
Marsupialia, 468.
Marsupials (their twofold origin ?) 516.
Masseter, 133.
Mastodon, 467.
Mastoid process, 66.
Mastoidal region, 66.
Materialism, 385.
Maternal conditions in, reproductive,
326,
Matrix, 17, 18, 20.
Matter for nutrition, 165.
», to develop warmth, 165.

93

INDEX, 545

MAXILLA.

Maxilla, 73.
Maxillary nerves, 273.
Maxillary process, 336, 337.
Maxillo-duricular, 131.
ae turbinal, 72:
Maximum of muscles to one digit of fore-
paw, 153.
of muscles to one digit of
hind-paw, 163.
Meaning of terms species, genus, family,
&e., 520.
Meati of nose, 72, 287.
Meatus auditorius externus, 64, 296.
™ internus, 66.
Mechanism of claw’s retraction, 102.
of respiration, 225.
Meckel’s cartila ge, 337.
ce ganglion, 273.
Median nerve, 278, 279.
Mediastina, 224.
Mediastinum testis, 243.
Medius (of fore-paw), 99.
Medulla oblongata, 260, 262.
its functions, 310.
Medullary cavity, 20.
~ groove, 320.
: , sheath, 254.
Megatherium, 468.
Meibomian glands, 288.
Membrana granulosa, 249.
ae nictitans, 288.
a tectoria, 302.
Membrane (basilar), 301.
Ps of Jacobson, 292.
A of Reissner, 301.
a Schneiderian, 287.
ea tympanic, 297.
Membranes (fluids passing through), 167.
- of nervous axis, 256.
- synovial, 53, 122.
Membranous labyrinth, 301.
fs semi-circular canals, 302.
% urethra, 242.
Meningeal artery, 208.
Mental acts, 386.
», foramen, 77.
+ powers (human), 872.
js. » words, 371.
Mesenteric artery, 211.
“ glands, 218.
ae veins, 216.
Mesenteries, 189, 190.
Mesethmoid, 71.
Mesoblast, 320.
Meso-cuneiforme, 115.
Mesonyx, 505.
Mesopterygoid fossa, 70.
Mesozoic mammals, 504.
55 | Strata, bOZ: «
Metacarpus, 98.
Metacromion, 90.
~Metapophyses, 39.
Metatarsus, 115.

9

MUSCLES.

Miacis, 506.
Mice, 469.
Microlestes, 504.
Middle Ages and the cat, 2.
Middle commissure, 266. -
», fossa of skull, &3.
», lateral gyrus, 269,
»» part of ear, 297.
Migration of parasites, 509.
Milk, 240.
», glands, 239.
», teeth, 29, 30; (question as to their
origin), 517.
Millipedes, 440.
Mind of cat, 386. -
Minimus (of fore-paw), 99.
Minute changes and evolution, 522.
», structure of liver, 187.
sa. _ _ Structure of lungs, 224,
Miocene strata, 502.
Mites, 450.
Mitral valve, 204.
Mixed joints, 121.
Mobility of spinal column, 54.
Modes (possible) of evolution, 519.
», of origin (our experience concern-
in=), 524.
Modiolus, 299.
Moisture, 495.
Molars, 29.
Molecular layers, 293.
Moles, 468.
Mollusea, 450, 452.
Mombas eat, 7.
Monocondyla, 455, 461.
Monodelphia, 469.
Monotremata, 468.
Monro (foramen of), 266, 267.
Morphological species, 391.
Morphology, 9
Morsus diaboli, 247.
Most gereral characters of cat, 440.
Motion and sensation, 304.
Motions (voluntary and involuutary), 124.
Motor tissue, 124.
Mouth, 170.
», formation o', 342.
Movable joints, 121.,
Movements (amceboid), 194.
Mucin, 169.
Mucous membrane, 21.
folds of, 27
of nose, 287.
of tympanum, 299

39 39
29 39
9?

Mucus, 26, 169.
Mud- fish, 458.
Mullerian ducts, 351.
Multifidus spine, 139.
Muscle fibrin, 125.
Muscles (actions of), 129.
» Classification of, 130.
», direction of, 153.
», origin of, 341.

A
A

(

546 ©

MUSCLES.

Muscles stretch of, 153.

of cat, 124.

of fore-arm, 149.
of ear, 131.

of internal ear, 299.

of the head and neck, 131.

of the limbs, 145.

of limbs, their serial homology,

163.
of hind-limb, 154.
of larynx, 229.
of the fore-paw, 152.
of tongue, 134, 171.
of trunk and tail, 136.

maximum of to one digit, 153, gs

163.

Muscular contraction, 124, 126.

39
33
3)

fibre cells, 125.
stimuli, 127.

tissue, 124; its function, 126 ;

INDEX.

NERVES.

Nematoidea, 509.
Neotropical region, 499,
Nerves (anterior crural), 281, 282.
», auditory, 274, 302.
»> auriculo- “temporal, 273.
», axillary, 279.
», cells or corpuscles, 255.
oi) eeervical, 27 7.
», chorda tympani, 274.
» circumflex, 278, 279.
o> Cranial, 269, S692
«dental, 273:
53. (Gorsal, aie
», dorsal spiral, 277.
eighth, 274.
», eleventh, 275.

»» external cutaneous of pelvic limb,

281282;
rp) baci 274.
» fibres, 254.

Se nae ab iia a

(development of), 331.
Musculo-cutaneous nerve, 278, 279.
spiral groove, 91; nerve, 278, 280.
Mustelide, 475, 518.
Myelon, 257.
Mylodon, 468.
Mylohyoid muscle, 134.
a nerve, 273.
Myology, 124.
of cat, its simplest expression,
164,
Myosin, 125.
Myrmecobius, 504, 515.
Myrtiformis, 131.

9?

- NAmes (zoological), 392.
Nares (formation of), 337.
», anterior, 59.
», posterior, 58.
Nasal artery, 238.
», bones, 74.
fossee, 86, 286.
process of frontal, 64.
ha Ot maxilla, 73.
Naso-frontal process, 336.
Nates. 262.
Native-cats, 468, 469.
Natural selection, 520.
automatism and know-
ledge, 384.
Nature (the cat’s place in), 440, 493.
of nervous activity, 305.
of primitive mammals, 515.
of species, genera, families, &c.,
520.

39
79

39 9?

99
7?
33

Navel, 176.

Naviculare, 113.

Nearctic region, 497.

Necessity of conception of internal force,
525,

Neck (muscles of), 131.
5, of femur, 107
»5 Of mandible, 77.

fifth pair, 271.
of fore-limb, 278. |
fourth pair, 271. .
gastric, 275.
genito-crural, 281, 282. .
glosso- pharyngeal, 274.
gluteal, 281. |
gustatory, 273.
hypoglossal, 275.
ilio-hypogastric, 281, 282.
ilio-inguinal, 281, 282.
inferior maxillary, 273.
internal cutaneous, 278.
laryngeal, 275

lumbar, 277.

lumbo-sacral, 281.

median, 278, 279.
musculo-cutaneous, 278, 279.
musculo-spiral, 278, 280.
mylo-hyoid, 273.

ninth, 274.

obturator, 281, 282.
olfactory, 270, 287.
ophthalmic, 272.

optic, -270.

pathetic, 271.

peroneal, 282.

pharyngeal, 275.

phrenic, 278.

plantar, 282. -
pheumogastric, 274.
popliteal, 2382.

pudic, 281.

pulmonary, 275.

radial, 280.

respiratory of Bell, 278, 279.
sacral, 277.

Sciatic, 282.

seventh, 274. |

SLXDH, eso:

spinal, 276.

spinal accessory, ate
splanchnic, 284.

EE TS ys eter eth epee tk

INDEX. 547
NERVES. ORGANS,
Nerves (subscapular), 278, 279. Obturator membrane, 116.
»» superior maxillary, 273. sf muscles, 156.
», supra-scapular, 278, 279. ff nerve, 281, 282.
weet tail, 283. Occipital bone, 61.
», tenth, 274. », . foramen, 57
» third pair, 271. - ridge, 61.
pa) Ghoracic, 281° Occipito-frontalis, 131.
yi tibial, 282: Ocelot, 408.
= dtrochlear,. 271: Ocelot-like cat, 411.
», twelfth, 275. Oculo-motor nerves, 271.
a ulnar, 278, 279. Odontoid process, 43.
», vaso-motor, 285. (Esophagus, 175.
ventral spinal, 277. Oldest tertiary mammal, 506, 514.
Nervous activity (its conditions), 307. Oleaginous substances, 166:
me its nature, 305. Olecranal fossa, 93.
Nervous excitement, 305. Olecranon, 96.
» functions (summary of), 316. Olfactory cells, 287.
», matter (white and grey), 256. Sr fossa, 23.
ey stimuly 305. a lobes, 260, 264.
Nervous system, 252. » nerves, 270, 287.
5 »» its peripheral part, 269. Olivary bodies, 263.
5 », its functions, 304. Olulanus (embryos of), 510.
ifs its origin, 355. A tricuspis, 509.
Nervous tissue, 253. Omenta, 190.
ss development of, 331. Omphalo-meseraic veins, 348.
Neural arch, 35. Ophiomorpha, 459.
», lamina, 35. Ophthalmic artery, 208.
es psychosis, 386. nerve, 272.
ae Spine, «35. Opisthotic, 69.
Neurapophyses, 35. Opossums, 468, 507.
Neurilemma, 255. Opponens minimi digiti (of fore-paw),
Neurility, 305. 152; (of hind-paw), 162.
Neuroglia, 256. ie pollicis, 152.
New forms (their origin experienced), 521. | Optic chiasma, 270.
Nictitating membrane, 288, 5, commissure, 264, 265.
Nimravus, 435, 502, 518. », foramen, 71.
Ninth nerve, 274. »» herves, 270.
», caudal vertebra, 47. », thalami, 268; their functions, 311.
Nipples, 239. 5» tracts, 263.
Nitrogenous excretion, 232. j Optical action of eye, 294.
m foods and tissues, 166. | Ora serrata, 292.
Nomenclature (zoological), 392. Oral and mental words, 371.
Non-nitrogenous foods and tissues, 166. Orbicular ligament, 101.
Normal forms, 490. Orbicularis oris, 131.
Northern lynx, 424. palpebrarum, 131.
Nose (cartilages of), 286. Orbital muscles (actions of), 294.
», development of, 363. », plate (of maxilla), 73.
», Meati of, 287. Orbito-sphenoid, 71.
»» mucous membrane of, 287. Orbits, 57, 85.
Notochord (its first appearance), 321. Orders of levers, 130.
Nourishment of ovum, 326. ,, of mammals, 466.
Nuclei, 17. Organ of Corti, 302.
Nucleoli, 17. », of Giraldes, 244.
Number of kinds of cats, 431. . » of hearing, 295.
Nutrition, 166. », of Jacobson, 288.
», of respiration, 220.
of sight, 288.
OBLIQUUS capitis inferior, 135. Organic chemistry, 12:
” 5» Superior, 135. », food needed by cat, 166.
, inferior muscle, 132. », geography, 11.
superior muscle, 132. Organism, its definition, 9.
Obturator artery, 213. Organs of circulation, 192.
a foramen, 104, 107, », development of, 329.

NN 2

548 INDEX.

ORGANS.

Organs (end), 255.
» generative, 240.
| enal, 2382.
», Of secretion, 220.
»» Of sense, 252.
»» Of smell, 285.
», Of special sense, 285.
systems of, 9.
Oriental region, 498,
Origin of the word cat, 2.
mo IMuscnlan- 128;
», Of forms as experienced, 521.
», Of Jife as experienced, 524,
», Of species, 528.
of cat, 519.
Origins of cranial nerves, 270.
Ornate jungle cat, 420.
Ornithodelphia, 469.
Ornithorhynchus, 469.
Orycteropus, 468.
Os caleis, 113.
», cuboides, 115.
», innominatum, 104.
», Magnum, 97.
», orbiculare, 298.
Mig ‘js origin of, 339.
», planum, 72.
», quadratum, 462.
Ossicles (auditory), 298.
Ossification, 20.
a8 of axis, 334.
ee of backbone, 334,

- of cervical vertebre, 334.
- of limb-bones,. 340.

ne of ribs, 334.

. of sacral vertebra, 334.

= of skull, 338.
of sternum, 335.
Os ee 246.
Otocyon, 479, 518.
Otoconia, 301, .
Otoliths, 301.
Otters, 475.
Ounce, 395.
Our unconscious actions, 384.
Ova (development of), 354.
Ovarian artery, 211.
», ligaments, 247.

Ovary, 248.

», its function, 250.

», development of, 352.
Ovisac, 249.
Ovulation, 251.
Ovum, 250.

», its nourishment, 326.
Oxen, 467.
Oxyena, 503.
Oxygen (exchange of), 220.
Oxyurus compar, 509.
Oysters, 450.

PENGUIN.

PACINIAN bodies, 22, 23.
Pads of cat’s feet, 25.
Paget (Sir James), 377.
Palearctic region, 497.
Paleonictis, 506, 514, 518.
Paleontology, 11.
Paleozoic strata, 502.
Palate, 170.

35. muscles of, 135,
Palatine bones, 75. °

- plate (of maxilla), 73.
Pale nerve fibres, 255.
Palmar arch, 210.

»5 |. faseia, 149:

Palmaris longus, 149.
Pampas cat, 423.
Pancreas, 183.

op formation of, 344.

uA of Aselli, 219.
Pancreatic juice, 184.

Panda (the), 475.
Panniculus carnosus, 136.
Panther, 394.

Papille, 22.

», cireumvallate, 172.

5 cervical, 172.

3 flattened, 172.

fungiform, 172.
Parachordal cartilage, 337.
Paradoxures, 481.

Paraguay cat, 7.

Parasites of cats, 509.
Parasphenoid, 457.
Pardalina Warwickii, 410.
Pardine lynx (the), 426.
Parenchyma of body, 9, 165.
Parepididymis, 244.
Parietal bone, 62.
Paroccipital process, 62.
Parotid gland, 172.
Parovarium, 250.
Parturition, 247.

Par vagum, 274.

Pasht, 3.

Patella, 109.

», ligaments of, 117.
Pathetic nerves, 271.
Patriofelis, 506.

Paws, veins of, 216.
Pectineus, 157.
Pectoral limb (skeleton of), 89.

», limb, general view of its skele-

ton, 102.
Pectoralis, 145.
Pedicle of vertebra, 35. -
Pedigree of cat, 512, 517, 518.
Peduncles of cer ebellum, 262.
a of olfactory lobes, 264, 270.
Pelvic girdle (articulation and ligaments
of), 116.

», limb (skeleton of), 103.
Peivis, 104.
Penguin, 462.

PENIS.

Penis, 241.

», development of, 352..
Penniform muscles, 128.
Pentastoma denticulatum, 510.
Peptic glands, 179.

Peptone, 180.

Pére David, 6.

Perforated transverse processes, 41.
Pericardium, 199.

Perichondrium, 18

Perilymph, 301.

Perimysium, 125

Periosteum, 18.

Periotic, 69.

Peripheral part of nervous system, 269.

Periplast. 330.
Peristaltic action, 181.
Peritoneal cavity formed, 322.
Peritoneum, 189.
a development of, 345.
general view of, 191.

Peroneal artery, 213.

bs nerves, 282.
Peroneus brevis, 160.

* longus, 159.

5» quinti digiti, 160.
Persian cat, 6.
Petit (canal of), 294.
Petrosal, 66.
Petrous bone, 66.
Peyer’s patches, 181.
Phalangers, 468.
Phalanges, 99, 116.
Pharyngeal nerves, 275.
Pharynx, 174.

ea constrictor muscles of, 135.
Phascogale, 516.
Phascolotherium, 504.
Phrenic artery, 209.

>> herve, 278.

»» veins, 216.
Phylogeny, 11, 512.

i of #luroidea, 514.
Physical conditions, 494.

Physical forces and nerve action, 306.

Physiological species, 391.
Physiology, 10.
—- of the individual, 11.
Pia mater, 256, 261.
Pillars of fauces, 170.
Pineal gland, 262, 266.
Pinna, 295.
Pinnipedia, 468, 473.
Pisces, 456.
Pisiform bone, 96.
Pith of hair, 23.
Pit for ligamentum teres, 107.
Pituitary body, 264.
a fossa, 33, 69,
Pivot joints, 122.
Place in nature of cat, 440, 493.
Placenta, 327.
Plane of cribriform plate, 85.

i

INDEX. 549

PREZYGAPOPHYSES,

Plane of foramen magnum, 85,
Planiform joints, 122.
Plantar nerves, 282.
Plantaris, 160.
Platysma myoides, 131.
Pleasure and pain, 314.
Pleure, 224.
Plexus (brachial), 278.

sy eervical; 277.

5» lumbar, 281.

ope Sacral 251.
Plexuses of sympathetic, 284.
Plica semilunaris, 288.
Pliocene strata, 502.
Pneumogastric, 274.
Pogonodon, 437, 502, 518
Poisonous gases, 221.
Polar vesicles, 318.

2» Vital force, 377.
Polecats, 469.
Pollex, 92
Polyzoa, 450. ;
Pons varolii, 260.
Popliteal nerves, 282.
Popliteus, 161.

4 depression for, 108.

Porcupines, 469.
Pores, 22.
Porpoises, 467.
Portal canals, 187.

55 | Sessuige, 185:

», system, 216.

>» vein, 187.
Portio dura, 270, 274.

» Mollis, 270, 274.
Porus opticus, 292.
Position of cat’s genus, 489.

5, Of viscera in body cavity, 176.
Posterior commissure, 267.
te fossa of skull, 83.

he hyoidean cornua, 77..
e nares, 58.
af palatine foramen, 76.
Post-glenoid foramen, 67.
process, 65.
Post-orbital ligament, 87.
= process ot frontal, 63.

Post tragus, 296.

Postzygapophyses, 36.

Potential lite, 524.

Potomogale, 468.

Pouched beasts, 468.

Poupart’s ligament, 141.

Powers of plants, 376.

Pregnancy, 247.

Premammalian ancestors of cat unknown,
518.

Premaxilla, 73.

Premolars, 28.

Preorbital process of frontal, 64.

Presphenoid, 70.

Presternum, 50.

Prezygapophyses, 35.

Bd Wy! Sy

550 INDEX,

PRIMARY.

Primary strata, 502.
Primates, 468, 472.
Primitive mammals insectivorous? 516.
he marsupial ? 515,
Primordial era, 254.
Principle of developmental changes, 387.
= of individuation, 376.
Principles of zoological classification,
449,
Procelurus, 435, 514, 518.
Proboscidea, 467, 472.
Process (acromion), 90.
3. eoracoid, ‘90:
», coronoid of mandible, 77.
»» \ ensiform, 50.
>. » hamular,: 70:
»» mastoid, 66.
»» nasal, 64.
», naso-frontal, 336.
», odontoid, 43.
», post-glenoid, 65.
»» post-orbital of frontal, 63.
- pre-orbital, 64.
», Of respiration, 220.
xiphoid, 50.
Processes (vertebral), 35.
Processus a cerebello ad testes, 262.
Processus gracilis, 298.
xe lenticularis, 298.
Procyonide, 474.
Products of waste, 232.
Profunda artery, 210.
Promontory, 68, 298.
Pronation and supination, 102.
Prenator quadratus, 151.
a3 teres, 149.
Pronuclei (male and female), 318.
Prootic, 69.
Prostate gland, 242.
Protein, 12.
Proteles, 475, 483, 518.
Proteus, 459.
Protoplasm, 12, 329.
Prototypal ideas, 529.
Protovertebre, 325, 33
Protractor muscles, 129.
Protrusion and retraction of claws, 102.
Provinces of Vertebrata, 455.
Proviverra, 505, 514, 518.
Pseudelurus, 434, 502, 518.
Psoas magnus and parvus, 156.
Psyche, 380, 386.
mn its functions, 382.
Psychical powers of cat, 366, 370.
Psychogenesis, 526.
Psychology, 11, 365.
mn and development, 389.
Psychoses, 386.
Pterodon, 505, 514, 518.
Pteropods, 450.
Pterygoid, 70.
- muscles, 133.
Pubis, 106.

RENAL.

Pubo-coccygeus, 143.

Pudic artery, 213. .
» merve, 281.

Pudu humilis, 490.

Pulex cati, 510:

Pulley of eye muscle, 132.

Pulmonary artery, 206.

3 circulation, 203.
i nerves, 275.
Ae veins, 214.
vesicles, 223.
Puma, 397.

Puncta lachrymalia, 288, 289.
Purpose, 527.

Pylorus, 178.

Pyramidalis, 131.

Pyramids of medulla, 263.
Pyriformis, 156.

QUADRATUS femoris, 156.

. lumborum, 156.
Quadriceps extensor, 158.
Quagga, 467.

Quasi-intelligence of cat, 367.
Quasi-valvule conniventes, 176.

RABsitTs, 469.
Racoons, 474.
Radial artery, 210.
>, nerve, 280.
» symmetry, 453.
Radiation of sensations, 310.
Radiolarians, 378, 450.
Radius, 93.
Rami of mandible, 77.
Rana, 459.
Rational science, 529.
Rat-moles, 469.
Rats, 469.
Realities (immaterial), 385.
Receptaculum chyli, 218.
Reciprocal influence of soul and body,
383.
Recti-muscle of eye, 132.
Recto-coccygeus, 144.
Rectus abdominis, 142.
», capitis anticus major, 135.
ae », minor, 135.
sr capitis posticus major, 135.

nf “4 minor, 135.
Af femoris, 158. ;
», lateralis, 135.

Red corpuscles, 194.
Reflex action, 310.
Regions of skull, 60.
ELIIOL general zoological geography,
497.
Reissner’s membrane, 301.
Renal artery, 211.
», organs, 232.
» velns, 216;

eS ee ee

Sat ae OD ee i ee ee ee a ee eel

INDEX. 551

REPRODUCTION,

Reproduction, 240.
Reptilia, 455, 461
Reserve air, 226.

Respiration (internal and external), 220.

system of, 220.
its mechanism, 225.

aa of embryo, 327.
Respiratory nerve of Bell, 278, 279.
Restiform bodies, 262.

# tract, 263.
Rete mucosum, 22.

»» vasculosum, 244.

Retia mirabilia, 196.
Retina, 292.
Retraction of claws, how effected, 102.
Retractor muscles, 129.

oe penis, 144.
Retrahentes auricularis, 132.
Revolutions of cochlea, 300.
Rhinencephalic fossa, 83.
Rhinoceroses, 467, 507.
Rhizopoda, 450, 454.
Rhomboidei, 145.
Ribs, 50.

» angles of, 52.

», ligaments of, 55.

», ossification of, 334.

», true and false, 50.

Right auricle, 205.
», ventricle, 205.
Rigor mortis, 128.
Rima glottidis, 229.
Ring (abdominal), 141, 143.

,, and collar joints, 122.
Ripening of ova, 251.
Rodentia, 468, 472.

Rodents, 469, 507.
Rods of Corti, 302.

»» and cones, 292, 293.

Romans and the cat, 2.

Rook (structure of), 462.

Roots of lungs, 224.

Rostrum of sphenoid, 70.

Rotator muscles, 128.

Rotatores spine, 139.

Rotifera, 450.

Round ligament of liver, 185, 191.
a3 of uterus, 247.

39
33

23
Ruge, 27
», of palate, 170.

Running, 129.
Rusty-spotted cat, 413.
Rythm, 226.

Ryzena, 481.

SAccuULE, 301.
Sacral foramina, 45.

»> nerve, 277.

a3) plexus, 2811.

», vertebre (ossification of}, 334.
Sacro-coccygeus, 143.

», iliac synchondrosis, 116.

SENSE.

Sacro-lumbalis, 138.
Sacrum, 44.
Saddle- shaped surfaces, 122.
Sagitta, 450.
Sacittal suture. 60.
St. Augustine, 527
St. Hilaire (Isid. Geef.), 377.
Saliva, 174.
Salivary glands, 172; formation of, 344.
vA ‘papilla, 172,
Sarcolemma, 125.
Sarcoptes cati, 510.
Sartorius, 157.
Scala media, 301. .
Scale of cochlea, 300.
Scaleni muscles, 134.
Scallops, 450.
Scaphoid (of hind foot), 113.
Scapho-lunar bone, 96.
Scapula, 89.
Schindylesis, 121.
Schneiderian membrane, 287.
Schwaun (white substance of), 254,
Sciatic nerves, 282.
Science, a knowledge of causes, 530.
», rational, 529.
Sclerotic, 289.
Scorpions, 450.
Scotland and the wild cat, 3.
Serotum, 243.
Sea-anemone, 450.
Sea-bears, 468.
Seals, 467, 468.
Sea-mice, 450.
Sea-urchins, 450, 453.
Sebaceous glands, 24.
Second pair of nerves, 270.
»» visceral arch, 338, 339.
Secondary creation, 527.
fussil mammals, 504, 516.
a6 strata, 502.
Secretion (its relation to nutrition), 166
en system of, 220.
&. its nature, 230.
Sectorial teeth, 28, 29.
Seeds and vitality, 524.
Segmentation, 329.
of yelk, 318.
Sella turcica, 69.
Semicircular canals (osseous), 300.

3?

Bs membranous, 302.
Semilunar ganglia, 284.
geue bivalves, 204.

Semi-membranosus, 158.
Semi-penniform muscles, 128.
Semi-spinalis, 139.
Semi-tendinosus, 158.
Sensation, 253.

and motion, 304.
Sensations (their localization), 308.
external and internal, 313.
are causes, 383.
Sense (organs of), 252, 285.

99

552 INDEX

SENSE.

Sense of hearing, 315.
» of sight, 315.

», Of smell, 315.
», Of taste, 315.
», of touch, 314.

Sensitivity, 374.

Sensus communis, its site, 311.

Septal line, 126.

», zone, 126.
Septum of tympanic cavity, 67.
2 lucidum, 266;

Serial homologies of limb muscles, 163.
ss 3 of limb skeleton, 120.
»» Symmetry, 15.

Series (the whole vertebral), 47.

Serratus magnus, 145.

»» posticus, 138.

Sertularians, 450.

Serum, 194.

Serval, 406.

Servaline cat, 408.

Sesamoid bones, 99.

Seventh cervical vertebra, 42,

5. merve, 274.

Sex, 240.

Sexual organs, 241.

of the sexes (fundamental

resemblances of ), 354.

Shaw’s cat, 421.

Sheep, 467.

Shrews, 468.

Shrimps, 450.

Siamese cat, 6.

Side view of skull described, 81.

Sight, 315.

1) Organon as.

Sigmoid cavities of ulna, 96.

Simplest expression of cat’s myology, 164.

Sinus pocularis, 242, 354
», venosus, 205, 347.

Siren, 459.

‘Sirenia, 467, 471.

Site of the ‘‘ common-sense,” 311.

Sixth cervical vertebra, 42.

»» herve, 273.
ia ib; 50,

Skeleton, what it is, 16.

a appendicular, 34, 39.
As axial, 34.

ns of head, 56.

te of head and trunk, 34.
a of the limbs, 89.

of fore and hind limbs (differ-
ences and correspondences),
119.

of pelvic limb, 103.

spinal, 34.

of thorax, 49.

9? 9?

‘Skin, 21.
,, muscles of, 136.

Skull, 56.

development of, 335.

“ viewed in front, 79.

9?

sees

SPINAL.

Skull viewed internally, 82.
»» Viewed laterally, 81.
», viewed ventrally, 7S.
», transversely bisected, 85,
», vertically bisected, 83.
»» Cavities of, 85.
»» generalized view of, 87,
», ligaments of, 86.
», ossification of, 338,

regions of, 60.

Sleep, 313.

Sloths, 468.

Small eat, 415.

Small-eared cat, 417,

Smell, 315.

» organs of,. 286.
Snails, 450.
Sneezing, 226.
Sockets of teeth, 27. -
Soft commissure, 266
», palate, 170.
Solar plexus, 284.
Solenodon. 468.
Soleus, 161.
Somatopleure, 322.
Soul, 380.
», its functions, 382.
», and body (reciprocal action), 383.
Special sensesa(organs of ), 285.
»» sensitive faculties, 314.
Specialized forms, 490.
Species (a), 391.
», development of, 512.
», morphological and _ physiologi-
cal, 391.
i, what iit really is, 520.
Specific’ sae 392.
Speech, 3
Sperm- pall aa germ- -cell, 318.
Spermatic artery, 211.
Fe cord, 243.
A fascia, 243.
‘5 filaments, 246,
re veins, 216
Spermatozoa, 245.
their action, 318.
Spermospores, 245.
Spheno-paiatine foramen, 76.
ganglion, 273. _
Sphenoid, 60S ane .
Sphenoidal fissure, 70.

He sinuses, 70, 86.
Spherical aberration, 295.
Spheroidal epithelium, 26.
Sphincter ani, 144.

=o muscles, 128.

Spiders, 450.
Spigelian lobe, 185.
Spinal accessory nerve, 275.

> cord, 257.
cord (commissures of ), 259.
cord (its functions), 309.
», marrow (development of), 356.

a

INDEX. 553

SPINAL, SYSTEM.
Spinal nerves, 276. Stypolophus, 505.
», nerves (their functions), 307. Subclasses and orders of mammals, 466.
» Skeleton, 34, 35. Subclavian artery, 209.
Spinalis colli, 138. ee vein, 215.
Spine of ischium, 106. Submaxillary gland, 173.
Spinous processes, 35. Subscapular nerves, 278, 279.
Splanchnic nerve, 284. Subscapularis, 148.
Splanchnopleure, 322. Substauce (material and immaterial), 378.
Spleen, 238. ¥ of teeth, 31.
», formation of, 350. Succession of teeth, 32.
Splenic artery, 211. Sulci, 261, 268.
yy vein, 217. Summary of alimentary processes, 168.
Splenius, 135. i of cat’s pedigree, 517.
Spermatic cord, 243, 245. a of cranial nerves, 275.
Spongida, 450. = of fossil cats, 438.
Spongy urethra, 242. of nervous functions, 316.
Spot (germinal), 250. Superficial fascia, 143.
Spotted cat of Fontaneir, 400. Superior dental artery, 208.
Springing, 129. he lateral gyrus, 268.
Squamosal, 64. me maxillary nerve, 273.
Squamous suture, 63. aA thoracic artery, 209.
Squirrels, 469. vena cava, 215.
Stapedius, 61, 299. Supernumerary digits, old.
Stapes, 298. Supination and pronation, 102.
», origin of, 339. Supinator brevis, 152.
Star-fishes, 450, 453. longus, 151.
Stellate ligaments, 55. Supplemental ait, 236.
Steno’s duct, 172. Support of the body, 129.
Stenson’s duct, 172. Supra-condyloid foramen, 91.
Steppe cat, 421. Supra-occipital, 61.
Stercorin, 188. Supra-orbital sulcus, 269.
Stereoguathus, 504. Supra-renal artery, 211.
Sternalis, 142. , ut capsules, 237.
Sternebre, 50. be », development of, 351.
Sterno-hyoid, 134. Supra-scapular nerve, 278, 279.
Sterno-mastoid, 134. Supra-spinatus, 148.
Sterno-thyroid, 134. Supra-spinous ligaments, 54.
Sternum, 49. Supra-tragus, 296.
», ossification of, 335. Suricate (the), 481.
Stimuli, 305. Suspensor oculi, 132.
», of muscle, 127. Suture (squamous), 63.
Stomach, 177. Sutures, 57, 60, 121.
», function of, 179. Sweat- elands, 29,
Stomata, 217. Sylvian fissure, 264, 269.
Strata of the earth, 501. Symmetry, bilateral, Eb:
Straw cat, 423. serial, 15.
Stretch of muscles (pectoral limb), 153. Sympathetic sy stem, 283.
at (pelvi ic limb), 162 ,, its functions, 312.
Striped muscular tissue, 125. Sy mphysis pubis, 106.
Stroma (of ovary), 248. it of mandible, 77.
Strongylus tubzformis, 509. Synarthroses, 120.
Structural nervous elements, 254. Synesthesis, 386.
Structure (minute, of liver), 187. Synovia, 53, 121.

», of stomach, 179. Synovial capsules, 122.
Stump-tailed cats, 7. »» membranes, 53.
Stylo-glossus, 134. Syntonin, 125.

Stylo-hyal, 78. System (co-ordinating), 258.
Stylo-hyoid, 133. , », muscular, 124.
Stylo-mastoid foramen, 65. 3 ~ervous, 252.

Stylo-maxillary ligament, 87.

Stylo-pharyngeus, 134. », portal, 216.

Styloid process of radius, 94. », Of respiration, 220.
es yc | Of ulna, 96, », of secretion, 220.

9» osseous, 34.

Ee ae
i Cag ae
a t ,

554 INDEX.

SYSTEM, t TRICKS.
System (sympathetic), 283. Thylacinus, 516.
», vasevlar, 192. . Thymus, 237.
Systemic circulation, 203. if gland (development of), 350.
year veins: 214: Thyro-hyal, 78, 134.
Systems of organs, 9. », hyals (origin of ), 339. 4
», hyoid, 134. {
TADPOLE, 523. Thyroidaxis, 209. }
Tenia crassicollis, 509, 510. -5, body, 237 ; development of, 350. a
»» elliptica, 509, 510. 5», cartilage, 78, 227. ;
»» gemiteres, 509. Tibia, 110. 7
», lineata, 510, 519. Tibial artery, 213.
» litterata, 509, 510 5. merves, 282. 4
Teeniada, 509. Tibialis auticus, 159.
Tail (muscles of), 143. n », posticus, 162. ;
»» nerves of, 283. Tics, 450. 1
Tapetum, 291. Tidal air, 226.
Tape-worms, 450, 509. Tiger, 393.
Tapirs, 467, 507. Time and the Felide, 501. |
Tarsus, 113. Tissue, what it is, 9.
Tasmanian wolf, 468. » adipose, 17, 18.
Taste, 315 ; organ of, 285. 55 areolar, 22. .
Taurec, 468. », cartilaginous, 18.
Taxonomy, 11, 467. » connective, 16, 17. :
Teats, 239. os. elaghicg ig; 4
Teeth of cat, 27. >, ° epithelial, 21. j
», formation of, 343. » erectile, 242.
», their functions, 171. 55 muscular, 124.
Temporal bone, 64. 99. . Mervous, 253.
af lobe, 264. osseous, 19.
8 muscle, 133. Tissues (development of ), 329.
Temporo-auricular, 131. Tongue, 171. ;
Tendo Achillis, 160. Tonsils, 170.
Es groove for, 113. Tooth substance, 31.
Tensor tympani, 299. ; »» succession, 32.
», vaginee femoris, 154. Tortoiseshell cats, 6.
Tenth caudal vertebra, 47. Touch, 314.
», dorsal vertebra, 38. » organ of, 285.
», merve, 274. » corpuscles, 22, 23.
Tentorium, 256. Trabeculz (of penis), 242.
Tenuissimus, 158. os cranli, 337.
Teres major, 148. Trachea, 223.
5, minor, 148, °. i Tracheal gland, 218.
Tertiary strata, 501, 502. Tragus, 296.
Testes, 243, 262. Transference of sensations. 310.
», development of, 352. Transformations of substance, 165.
Theistic idea (the), 527. Transversalis, 142.
Thibet lynx, 426. cervicis, 138.
», tiger-cat, 400. Transverse colon, 182.
Thigh (glands of), 218. 5 process, 35.
»5 muscles of, 154. ” processes perforated, 41.
Third eyelid, 288. Transversus pereneei, 144.
», branch of trigeminal, 273. Trapezium, 97.
», pair of nerves, 271. Trapezius, 137.
», ventricle, 265, 266. Trapezoides, 97.
», visceral arch, 338, 339. Trematoda, 450, 509.
Thoracic aorta, 210. Trepang, 450.
55 duct, 288. : Triangularis sterni, 141.
- nerves, 281. Triceps, 149.
Thorax (skeleton of), 49. Trichina spiralis, 509.
», asa whole, 52. Trichodectes subrostratus, 510.
Thoughts (their oral expression), 372. Trichosoma cati, 509.
Thread-worms, 450. Tricipital muscles, 128.

Thylacine, 468. Tricks played with language, 443.

INDEX. 555

TRICUSPID.

Tricuspid valve, 204.
Trigeminal nerves, 271.
Trigone, 235.
Trochanters, 107.
Trochlea of humerus, 93.
Trochlear nerves, 271.
Trucifelis, 438.

True molars, 29.

aa Tibs,( 50,

5, vertebre, 36.

», vocal cords, 229.
Trunk (muscles of ), 136.
Tuber cinereum, 263.
Tubercle of Lower, 205.

sf of tibia, 112:
Tubercular surfaces of vertebra, 38.
Tuberculum of ribs, 50.
Tuberosities of humerus, 92.

: of tibia, 112.
Tuberosity of ischium, 106.
es of maxilla, 73.
- of os calcis, 113.
he of radius, 93.
Tubes (bronchial), 225.
Tubeworms, 450.
Tubuli recti, 244.

», seminiferi, 243.

» uriniferi, 233.
Tunica albuginea, 243.

ee etorosa, 249,

»» granulosa, 250.

», Ruyschiana, 291.

», vaginalis, 2438.
Tunicata, 450, 453.
Tunicates, 523.

Tupaias, 468.
Turbellaria, 450.
Turbinal (ethmo), 71.

pet (Maxton 2.

Twelfth nerve, 275.
Twofold origin of Marsupials ? 516.
Tympanic, 65.
a cavity, 67.
membrane, 297.
Tympano- hyal, 65.
» cartilage of, 78.
Tympanum, 297.

its mucous membrane, 299.

Type of Av es, 462.

71 OF Batrachia, 459.

», of fishes. 456.

»» of reptilia, 461.

», Of species, 390.
Types, utility of their study, 530,
Typical forms, 490.

Uitwa, 95.
Ulnar artery, 210.
»» Nerve, 278, 279.
Umbilical cord, 327.
35 fissure, 185.
oa veins, 348.

VEINS.

Umbilical vesicle, 325.

i vessels, 327.
Umbilicus, 176.
Unciform bone, 97
Unconscious actions (our), 384.
Ungulata, 467, 472.
Unstriped muscular tissue, 125.
Urachus, 235, 351.
Urea, 232.
Ureters, 233, 235.
Urethra, 242.
Urinary organs, 350.
Urine, 235.
Urogenital sinus, 351.
Urside, 474, 518.
Uterine artery, 213.
Uterus, 246.

» its ligaments, 247.

Utility of studying types, 5380.
Utricle, 242, 301, 354.

VACUOLATION, 3829.
Vagina, 246.

», anduterus (development of), 352.
Valve of Vieussens, 262.

», lleo-cecal, 188.
Valves of heart, 204,

», of veins, 196.
Valvule conniventes (quasi), 176.
Variety (a), 391.

Vas aberrans, 244.
», deferens, 244.
Vasa efferentia, 244.

aon RECA, 244 ey)

», vasorum, 196.
Vascular system, 192.
Vaso-motor nerves, 285.
Vastus externus, 158.

3 internus, 159.
Vegetal functions, 10.

>> powers, 376.

» psychosis, 386,
Veins, 196, 214.

oe axillary, 21S.

99 . azygos, 217.

jo LOtachial, 215,

a. bronchial, 225.

os, Capsular, 216.

», cardinal, 347.

»» caudal, 216.

», development of, 346.

»» temoral, 216.

ss) Bepatic, 167.

edna, 206.

3» iImnominate, 215.

»» intercostal, 217.

» jugular, 215.

», lumbar, 216.

», mesenteric, 216.

», minute, of liver, 188.

», omphalo-meseraic, 348.

»» Of paws, 215.

556 INDEX.

VEINS.

Veins (phrenic), 216.
55 portal, 187.
»» pulmonary, 215.
»» renal, 216.
», spermatic, 216.
», Splenic, 217.
», ~subclavian, 215.
» systemic, 214.
»» umbilical, 348.
vertebral, 215.
Velum interpositum, 266.
», palati, 170.
Vena cava superior, 216.
Vene cave, 216.
x, comites, 196.
Venous blood, 195.
Ventral common ligament, 52.
» pilates, 322.
i skeleton, 49.
» Spinal nerves, 277.
Ventricles of brain, 260, 265.
AG of heart, 205.
vias of larynx, 229.
Verification, 381.
Vermes, 450, 509.
Vermicular motion, 181.
Vertebra, 35.
is atlas, 44.
a6 axis, 43.
= dentata, 43.
Vertebree (caudal), 46
cervical, 40.
5 dorsal, 36, 37.
lumbar, 39.
ps sacral, 44.
Bs true and false, 36.
Vertebral artery, 209.
_ canal, 35; of transverse pro-
cesses, 41.
categories, 36.
~ epiphyses, 334.
grooves, 48.
processes, 35.
series, 47.
vein, 215.
Vertebrata, 451, 455.
Vertebrate aroups, 455.
Verum montanum, 242.
Vesica prostatica, 242.
Vesical artery, 213.
Vesicle (germinal), 250.
Vessels (absorbent), yAW B
Vestibular nerve, 302.
Vestibule, 246.
a of ear, 299.
Vibratile cilia, 25, 175.
Villi of intestine, 181.
Viscera (their relative positions), 176.
Visceral arches, 326.
the first, 337, 338.
second, 338, 339.
third, 338, 339.
(formation of), 335.

>> 99

29 99

a?

ZONA»

Visceral clefts, 326. 5
Viscero-skeletal muscles, 130. :
Vital capacity, 226

», force and nervous activity, 306.

», innate force (polar), 377.
Vitelline duct, 327.
Vitreous humour, 293.
Viverriceps planiceps, 417.
Viverride, 475, 488, 481, 518. 3
Viverrine origin of cats, 518. | a
Vocal cords, 227, 229.
Voice, 229.
Voluntary motions, 124.
Vomer, 76.

W aGartI, 404. :
Walking, 129. |
Warm-bloodedness, 222. :
Waste, 166.

», products, 232.
Water lost in respiration, 222.
Weasels, 468, 475.
Whales, 467.
Wharton’s duct, 173.
What is a cat ? 440, 493.
Wheel animalcules, 450.
Whelks, 450.
Whiskers of cat, 24.
White corpuscles, 194.

»,» herve-fibres, 254.

»» hervous matter, 256.

», substance of Schwann, 254.
Wild cat, 4.
distribution of, 3.

> » gestation of, 8.

o>” %sy aad! Treland?as-

era bes eld Scotland, 3.
Willis (cirele of), 209.
Winslow (foramen of), 190.
Wombat, 468.
Wool, 23.
Woolfian bodies, 350.
Woolly cheetah, 429.
Word (the oral and mental), 371.
‘*Worm ” of the tongue, 171.
Worms, 450.

= of cat, 509.

2) 99

XIPHOID process, 50.

YAGUARONDI, 412.
Yawning, 226.
Yelk (its segmentation), 318.

ZIBET, 481.
Zona pellucida, 250.

"ZOOLOGICAL. a Ors ZYGOMATO.

Z 0 ogical groups (their real nature), | Zygencephala, 455.
st 520. Zygoma, 58.
; Raeieancla tate, 392. Zygomatic glands, 173.

3 process, 64...
: m, 527. Zygomaticus, 131.
tomy, 10. Zygomato-auricularis, 132,

pophyses, Be

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