Artistic Anatomy of Animals

TR

rtebra

f the skeleton with a d

a Quadruped. To give a general Idea of the

the thorax occupies the anterior part, the abdomen is placed behind it; the vertebral column is horizontal, and is situated at the superior aspect of t

hree-toed sloth, and six in the manatee); we always find seven cervical vertebr?, whatever the length of the neck of the animal. There are no more than seven vertebr? in the long neck of the giraffe, but they are very long ones; and not less than sev

hows their classifica

teb

. Dorsal

r 7

7

7

it 7

14 6

7 18

7

l 7

ffe

7 1

p 7

spinous processes; the two or three last vertebr? are similarly united to the iliac bones, between which they are fixed. The dorsal vertebr? thus form one piece, which gives solidity to the trunk, and provides a base

teb

cal.

ure

le

k 1

ich

n 2

se

k 1

at of the dorsal is very variable; some serpents are devoid of cervical vert

teb

. Dorsal

dile

an 7

3

on 0

r 2

th the Transverse Dimensions of the C

; 3, external occipital prot

face of that of the quadruped. Of the cervical vertebr?, the atlas and axis call for special notice. Apropos of the atlas, we find that it, in the human being, is narrower than the corresponding parts of the skull, and is therefore hidden under the base of the cranium (Fig. 2); in quadrupeds its width i

the Transverse Dimensions of the corre

3, external occipital protu

) arch of the atlas, according to the direction of the neck. The spinous process, flattened from without inwards, is more

rd to the other vertebr? of this region, they diminish in width from the second to the seventh; and, in some animals, the anterior surface of the body presents a tub

seventh, the spinous process of which, long and pointed, well deserves the name of the prominent which is

ent crest, especially well marked at the posterior part; this crest is but sl

vertebr?, from their relation to the trac

eloped and are directed obliquely upwards and backwards. As we approach the last vertebr? of this region, the processes become shorter and tend to become vertical, and the last ones are even, in some

tebr? produce the prominence at the anterior limit of the

of a Quadruped (the Ho

ss and transverse process of the first lumbar v

and still more readily by their transverse processes, which, as they are evidently atrophied ribs, it is more accurate to

of the articular processes of each of the vertebr? of the lumbar region. Apropos of these di

e terminal ones articulate with the base of the sacrum. Sometimes the processes of the fourth and fifth are thus related; this is the case

lly in animals which have not much flesh, prominences which limit the flanks in the superior aspect. The costiform pro

ed by the mutual coalescence of several vertebr?, wh

y of man, study these bones with the bones of the lower limbs. Here we do not follow this plan. In animals the sacrum and the coccyx,

5; dogs, 3; cats, 3; rabbits, 4; swine, 4

f the pelvis. It is obliquely placed, from before backwards, and from below upwards; immediately behind the lumba

d massive, and of greater density, in species which sometimes assume the upright posture, rather than in those which cannot assume that att

ther bones of the pelvis. We think that the general form of this bone depends on the mode of its connexion

the vertebr? which form it. In certain species these processes are attached only by thei

a small series, the coccyx; which is inclined forwards, that is to say, towards the interior of the pelvis. In quadru

of other regions: they have a body, a foramen, and processes. As we trace them backwards, these characters become

Form of the

ze the human spine. First, instead of their being, as in the latter, curves in the antero-posterior a

one superior, with its convexity looking upwards; the other inferior, the convexi

ve analogous to that which exists in man; a form which, in the latter, is due to the biped attitude-that is to say, the vertical position of t

rum and the caudal appendix, which describe a curve of

ubstitutes its modelling influence for that of the vertebr?. It is the superior cervical ligament, which arises from the spinous process of the first cervical vertebr?, and is inserted into the external occipital protuberance on the upper part of the posterior surface of the skull. The summits of the

Th

ds, of the region of the trunk known as the thorax. A single bone, the sternu

ut the progressive widening takes place in a more regular and continuous fashion, so that it presents a more definitely conical outline. This purely conical form is nevertheless found in the human

ally-that is to say, in the Direction which it would assume in a

on; 3, costal region of one side; 3

etween the sternum and the vertebral column is shorter than the distance from the rib of one side to the corresponding one of the opposite side (Fig. 5). In animals, o

ion of the Thorax of a

egion; 3, costal region of one side; 3

f the pectorals is narrowed. It is not spread out, as in the preceding instances; and the appearance it presents is explained by the fact that the thorax is compressed laterally. If we examine the thorax on one of its lateral surfaces, the muscles, on the contrary, are more extended. We see the contour of the vertebral column, and the median part of

drical in form, being slightly flattened from within outwards, and thickened at their extremities. They remain separate, and this contributes elasticity and flexibility to the thorax. The f

rocess, but slightly marked posteriorly, becomes more and more prominent in front, and terminates at its anterior extremity by a prolongation, slightly curved backwards, which projects for some centimetres beyond the cavity in which the first costal cartilage is received.

onger, and is formed by the fusion of several small bones; it is placed horizontally, and is flattened from above downwards. At the level of articulation of these two portions, and because of their different directions, the bone is bent. This bend occurs at the point

e clavicles are wanting. In the first case, this extremity is large, and approaches in shape to the corresponding part of the human sternum, whic

ows, will be more striking, on account of the mobility of his upper limbs) the sternum gives origin to the pectoral muscles, and that these muscles are inserted into other parts of the thoracic limbs, designed by their contraction to draw the arms downwards, forwards, and inwards-that is, when these are in a state of abduction an

muscles commensurate with their development is necessary, a very large and peculiarly shaped sternum (Figs. 18, 6; and 21, 6). Indeed, not only is the sternum large, but, further, in order to form a deeper surface, proportionately adapted to the mus

ird (the Cock): Left S

rocess; 5, external process; 6, inferior ribs; 7, costal p

s, two on each side, are called from their position the internal and external slots. They are bounded by narrow, elongated, bony processes, an internal and an external; the expanded lower extremity of the latter overlaps the last inferi

ch run, but do not fly, the sternum has the form of

s only), or the absence of this faculty, has furnished the division of birds into two groups. In one are included, under the name Carinates (carina, keel), those in which the sternum is provide

eloped in flyin

, the ribs which articulate with the sternum by their cartilages are called true, or sternal ribs; those whose cartilages do not

he posterior ones than in the anterior. They are, however, less oblique than in the human being

ing, but this is not equal in all animals. The ribs of the bear are more curved

iculation with two dorsal vertebr?, a neck, and a tuberosity. External to the tubercle are found

e the number and classificatio

ibs on Each Sid

l. Ast

ivided in

3 ? ?

3 ? ?

12 ?

4 ? ?

18 ? ?

12 ? ?

? ?

13 ? ?

uely downwards and forwards, of the fossa which is found at the inferior and posterior part of the thorax, and which forms the lateral limits of the epigastric region. In the dog and cat the ribs are thick and almost cylindrical; the costal cartilages are thicker at the margin of the sternum than at their costal extremity. In the ox, the ribs are flattened laterally and are very broad, the more so as we examine a portion further from the vertebral column. From the second to the twelfth they are quadrangular in the superior fo

th from the first to the sixth or seventh, and the following ones become narrower. The costal cartilages, from the second to the e

from the posterior border, is directed backwards, and overlaps the external surface of

y articulation; by the other extremity they are joined to the sternum; the first superior ribs generally want them. Sometimes the last inferior rib becomes connected w

rds, the costal cart

ERIOR L

igs. 21, 33,

e shoulder, the arm, the forearm, and the hand. These limbs, considered in the vertebral series, present the

b of the Bat: Left S

4, radius; 5, cubitus; 6, carpus; 7

series we study them, we can readily find the relationship of the different parts; it is very easy to recognise the same bones in the upper lim

of the Seal: Left Si

s; 4, ulna; 5, carpus; 6, metaca

y, in the muscular mass which binds it to the lateral wall of the trunk; so that

Shou

es-the scapula and clavicle; in others of only one bon

he lateral surface of the thorax, and is directed obl

t if we look at the human thorax on one of its lateral aspects we see chiefly the external border of the scapula; it is the external surface (homo

Being, the Trunk being Horizontal, as in Quadrupeds. Vertic

the thorax; 2,

ula in Quadrupeds. Vertical and Transverse

the thorax; 2,

e in quadrupeds, the surfaces are situated in a plane which is almost perpendicular to the ground (Fig. 11). This position of the scapula in an almost ve

terior Surface, placed in the Position which

; 3, axillary border; 4, supraspinous fossa; 5, subspinous fossa; 6, spine of the scapula; 7, glenoid cavity; 8, coracoid process. The scapula of the hor

al, anterior, and the axillary, posterior. In direct contrast to what obtains in the human scapula,

pula of a Horse:

supraspinous fossa; 5, subspinous fossa; 6, scapular spine;

eep, horses) the superior, or spinal, border of the scapula is

ition of the word

, at the Site of the Shoulders, of the T

l vertebra; 2, 2, scapula; 3, spinal border of the scapu

the bone and cartilage are not distinguishable in the contour of the corresponding region of the back; being applied to the lateral surfaces

n, at the Plane of the Shoulders, of th

hird dorsal vertebra; 2, 2, scapula; 3, spinal

en the animal is resting on its fore-limbs, particularly when it crouches; at such a time the skin is markedly raised by that border; and the spinous processes of the vertebr?, beyond which it pr

inition of this

of the Cat: Superior

remity; 2, exte

cle of the Dog

bs in quadrupeds. A few words will suffice to prove that there must be another reason. The scapula is not in immediate contact with the ribs; the subscapular fossa is not moulded on them. Besides, the form of the scapula is, as in other parts of the skeleton, dependent on the disposition of muscles, and the development of these latter is correlated to the extent and energy of the movements which the individual is able or required to execute. But the movements which those muscles produce (more especially the rotation of the humerus) are, in quadrupeds, less extensive than in the human being; and, consequently, the muscl

er of a Bird (Vulture): Antero-

urchette; 3, coracoid bone; 4, scapula; 5, articular surface for humerus; 6, superior half of the sternum; 7, keel of st

it is also flat, and has no spine. Its coracoid process is represented by a peculiar bone-the coracoidean or coracoid bone-whi

dom of movement in all directions, require that the scapula should possess a point of support which, while affording th

ackward directions only; they merely fulfil the functions of giving support to and carrying about the body. The clavicle is rudimentary in the cat and the dog; in the cat it is a small, elongated bone (Fig. 16), 2 centimetre

neck to the humerus (mastoido-humeral, a muscle common to the arm, ne

imbs for digging, grasping, or flying; the insectivora (hedgehog,

ll-developed clavicle, on account of the varie

sed together by their lower extremities, form one bone, having the shape of the letter V or U, which is known as the fourchette; this bone,

ck, and the fourchette is U-shaped. Those whose flight is awkward and but slightly energetic have

a. If we fancy this process directed inwards, and sufficiently lengthened to join the sternum, we shall have an idea of the disposition of the bone we are now discussing, and the reasons for which the name has been chosen by which it i

se latter, a foramen which gives passage to the tendon of the elevator muscle of the wing, or small pectoral. The importance of the fourc

e

forms the skeleton of this p

in quadrupeds, inclined from above

sened. In the horse, for example, whose metacarpus is long, and in which but one digit is apparent, the humerus is very short

t its inferior extremity. Later on we will return to the consideration of this peculiarity an

s the external surface, and is very deep in some animals. Above this groove, and on the external surface, there exists a rough surface which is the impression of the deltoid. In some species this rugosity is very prominent, and is called the

f its superior extremity, and not at the level of its body; this does not authorize us further to accord any definite sense to the denomination 'groove of torsion' (musculo-spiral groove). That which we must especially remember in connection with

ble in three portions which it presents; these

looking backwards in all, the result is that the head of the humerus is not situated vertically above the same regions; in the first, it is almost directly above the internal part of this extremity; in the latter, it is situated above its posterior surface, or the point of the elbow in the complete skeleton. This difference of direction is correlated with t

est; these different parts give insertion to the muscles of the shoulder. We recollect that the facets (anterior, middle, and posterior) of the great tuberosity of the humerus in man give attachment to the muscles of the same region. The head of the humerus in the human bod

anterior part of this extremity, although similarly covered by muscular bundles, produces a prominence under the skin. This prominence is situated at the summit of the angl

ar surface, which reminds us of the trochlea and the condyle of the human hum

ondyle. In the bear, the cat, and the dog, it is the same. In the ox and the sheep, the condyle is lower than the t

chlea; and, externally, another, the epicondyle. It is from this latter that the cre

t the extremity tends to become narrow transversely, and that the epicondyle and the epitrochlea are less and less prominent on the external and internal aspects respectively. These two processes, indeed, project backwards; the epitrochlea always remaining more developed than the epicondyle. Because of this projection

emity of the Left Hume

2, supra-epitr

l (Fig. 19). It is bounded by a plate of bone which at its middle portion is detached from the shaft of the humerus

Left Human Humerus, showing the P

2, supra-epitr

epitrochlear process-situated 5 or 6 centimetres above the epitrochlea; the summit of this process gives attachment to a fibrous band, which is inserted by its other end into the epitrochlea and the internal

ternational Journal of Anatomy and Physiology, 1889); A. Nicolas, 'New Studies on the Supr

one which, in others, separates the olecranon fossa from the coronoid. T

of a Bird (Vultu

f the shoulder, see Fig. 18); 12, humerus; 13, radius; 14, ulna; 15, carpus; 16, hand (for details of the skeleton of this region, see Fig. 31); 17, ilium; 18, ischium; 19, pubis (for the details of the pelvis, see Fig. 46); 20, femur

s and backwards (Fig. 21), it is proportionately longer in individuals of powerful flight than in those which fly less or not at all. In the vulture it projects beyond the posterior part of the pelvis; in the cock it does not even re

d, which is turned forwards and a little inwards, is convex and elongated in the vertical direction. Behind and above this head is found a crest for the insertion of muscles. It is the same for the region below, where there is a tube

ularly draw attention to the osseous framework, the structure of which is such that the weight of the animal is greatly lessened. This condition is secured by the pneumaticity. The bone consists of

the power of flight; as a matter of fact, we find air spaces in the bones of some

d from without inwards. It terminates in two articula

htly developed, it follows that the olecrano

the Form of the

sent the greatest variety in regard to the number of bones and also in reg

are parallel, and that this position is known by the name of supination. It is also necessary to remember that there is another attitude, in which the radius, cross

f support, to place the forearm in pronation, in order that, as is more normal, the hands may rest on the ground by their palmar surfaces. In this position the radius, being rotated on i

attitude of the hand in quadrupeds. In short, quadrupeds

r its Whole Extent on its Palmar S

rtions of his hands; the whole palm of the hand may be applied to the ground (Fig. 22); or the fingers only-that is to say, the phalanges (Fig. 23); or the extremities of

sting on its Phalanges: Le

ve the paws applied to the ground by the whole extent of the palmar surface of the hand, from the wrist to the tips of the fingers. The

n the Tips of some of its Third P

ent of the palmar surface, but on the corresponding surface of the fingers only-the metacarpus is turned back,

ls, the third phalanx is enclosed in a case of horn, a nail (the hoof), and because the support of the limb is on that nail, the name of unguligrades has been given them. Nevertheless, as the point of support is on the third phalanx, which is also known by t

to make an exception of the camel an

ligrades, the number of bones of that region diminishes, the bones of the forearm coalesce, and the ulna tends to disappear; the hand become

ove his paws in every direction, and climb a tree by grasping it with his fore-limbs. It is well known, however, that no animal except the ape can perform the movements of rota

ped, and which is always removed from the ground-that is, the thumb:

metacarpus is reduced to a single piece, which in the horse constitutes what is known as the canon. The number of digits becomes diminished, so that in ruminants there are not more than two, and in the horse but one. We should, however, add that, up to the present, we have taken into account only perfe

sheath, which forms the hoof of the horse and the corresponding structures (onglons) in the ox, those animals

hened by an epidermic sole and fatty pads, have the free extremities of the third phalanges

during flight, when the wing is being lowered, the radius and hand shall not be able to turn; for, if such rotation took place, each stro

Fo

d downwards and inwards. In animals in which the bones of the forearm are separate-that is to say, susceptible of supination and pronation-we find a more close resemblance to those of the human skeleton. The ulna, the superior extremity of which always proje

, the olecranon, which forms the point of the elbow. We find on

the Bones of the Human Forear

3, olecranon process

he Bones of the Forearm of the D

3, olecranon process

small sigmoid cavity with which the head articulates is situated on the outer side of the coronoid process, and this apophysis is placed in front. In the plantigrades and digitigrades the head of the radi

he Bones of the Forearm of the H

3, olecranon process

h in man belong exclusively to the ulna-for example, the coronoid process. In the plantigrades and the digitigrades half of the process still belongs to the ulna and the remaind

rades, and finally in unguligrades, we find a kind of progressive absorption of one

y, the head, that the corresponding extremity of the radius turns. But when the movements of rotation of the forearm do not exist, the inferior extremity of the ulna becomes functionally useless and disappears. As to its r?le in the movements of the region of the wrist, that is nil, for we may

umero-ulnar articulation); its olecranon process limits the movement of extension of the forearm. It is for this reason that, even

human forearm are grooves in which pass the tendons of the posterior and external

s of the Forearm of a Man: Left Side, P

scles; C, groove for the long extensor of the thumb; D, groove for the special extensor of the index finger and of the c

sess a clear conception of this, it is necessary to remember that, in this latter, the bones of the forearm are always described as in the position of supination; they are

orearm of the Dog: Left Side, Anterior Surface, N

e for the radials; D, groove for the long extensor of the thumb, the special extensor of the index-fi

garding them in passing from the radius towards the ulna, those grooves give passage to the tendons of the muscles whose names occupy the

he Bone of the Forearm of the Ho

he thumb; B, groove for the radials; D, groove for the common extensor

t level, the groove is situated on the external surface of the inferior extremity of the radius. It is necessary to add that, in some horses, the ulna is, nevertheless, represented in this

Dog.

of the thumb united as one muscle, the oblique extensor of the metacarpus.[11] A. Oblique extensor of the metac

o radials blended superiorly, distinct inferiorly; this is the anterior extensor of the metac