ANATOMY. 
73 
than any of the superior ones. The os sacrum 
resembles a pyramid reversed, somewhat con- 
cave internally and convex externally. It 
constitutes the posterior part of tire pelvis, 
and in the young animal consists of live dilie- 
rent portions, resembling considerably the 
true -vertebra*, whence its name of false ver- 
tebra*. The os coccygis, inform, very much 
resembles the os sacrum, of which it is mere- 
ly an appendix lixed to its lower part. 
The pelvis, or inferior cavity of the trunk, 
in arlcli k n to the two bones last mentioned, 
consists ci the two ossa irmominata. These, 
in the young, subject, are formed of three 
distinct bones, Viz. the ossa ilium or haunch 
bones, which are placed at their upper part, 
the ossa pubis or share Bones, which compose 
their fore part, and the ossa ischium which 
constitute their inferior part. 
The tliorax, or superior cavity of the trunk, 
in addition to the vertebra*, is formed ante- 
riorly by a long narrow bone, named sternum, 
and laterally, as well as in some measure ante- 
riorly and posteriorly by the twenty-four nbs, 
which are long, narrow*, and curved bones, 
attached by their heads, or posterior ends 
to the vertebra*, arid by their anterior carti- 
lages either to the sternum or each other. 
The upper seven, from their being attached 
in the former way, are named time ribs;, the 
inferior live are termed false. 
The bones of the upper extremities are ge- 
nerally divided into those of the shoulder, 
arm, fore arm, and hand. 
The shoulder consists of two bones, viz. the 
clavicula and the scapula. The clavicula or 
collar bone, is situated between the top of the 
sternum or breast-bone and the extremity of 
the shoulder, and sometimes resembles in 
form an italic f. The scapula is a triangular 
flat bone, which forms the greatest part of 
the shoulder. It is in some measure situated be- 
hind the upper part of the thorax. Its supe- 
rior and inferior sides are denominated costae ; 
its posterior side is called its base. 
'i'lie arm has only one bone, termed the os 
humeri, the upper part of which forms a 
round head, which is received by the scapula, 
and its lower part terminates in two condyles, 
giving attachment to muscles, and a trochlea 
or pulley between them, for articulation with 
the following bones: 
'Idle fore arm consists of two bones, viz. 
the radius and ulna, the latter of which is 
placed on the inside of the fore arm, and 
chiefly allows of flexion and extension, while 
at the same time it serves as an axis to the 
radius, which so revolves around it as to ef- 
fect that which is called the supination and 
pronation of the hand. 
The bones of the hand are divided into those 
of the carpus,' metacarpus, fingers and thumb. 
The carpus consists of eight small irregular 
Bones, named schaphoides, lunare, cunei- 
forme, and piziforme, which form the first 
row; and trapezium, trapezoides, magnum, 
and unciforme, which form the second. The 
metacarpus consists of four bones, having 
Broad bases attached to the carpus, and 
round heads for articulation with the fingers. 
Each of the fingers, as well as the thumb, 
consists of three bones ; all of which, except 
the terminating ones, possess a head and base 
tipped with cartilage for articulation with its 
fellows. 
The bones of the lower extremities consist 
of those pf the thigh, leg, and foot. 
The thigh has only one bone, termed os fe- 
moris, the upper part of which forms a round 
head, received by a cup-like cavity, called 
acetabulum, of the os innominatum. Below 
this is the neck of the bone, and at its base 
two protuberances called trochanters, into 
which are lixed the muscles' which rotate 
the thigh. '1 he back of the bone is marked 
by a rougli line which divides into two at its 
lower part, and terminates in the condyles of 
the bone ; which inferior!)’ are joined to the 
tibia, a bone of the leg, and laterally give at- 
tachment to various muscles. 
The bones of the leg are three in number, 
viz. the patella or knee-pan, a small round 
bone, requiring no particular description; the 
tibia, which is superiorly large, has a trian- 
gular body, and terminates interiorly in the 
malleolus internus, or inner ankle; and 
the fibula, a long triangular bone, placed oh 
the outside of the leg, articulated above to 
the tibia, and below terminating in the mal- 
leolus externus or outer ankle. 
The bones of the foot are divided into those 
of the tarsus, metatarsus, and toes. The tar- 
sus consists of seven bones, named astragalus, 
os calcis, naviculare, cuboides, cuneitorme 
externum, medium, and internum. The me- 
tatarsus is composed of five bones, having- 
broad bases arid round heads. The phalanges 
of the toes are three in number: each of their 
bones are shorter than those of the finger, and 
the great toe possesses only two. 
CHONDROLOGY. 
Under this head it is only necessary to state 
that, in the recent subject, all the articular 
surfaces of bones are covered by cartilage. 
Interarticular cartilages are also placed in 
some of them, as in the joint of the lower 
jaw, of the clavicle and sternum, of the knee, 
&c. 
SYNDESMOLOGY. 
Capsular ligaments surround all the joints, 
but those which possess the hinge-like motion 
have also lateral ligaments to render them 
firm, and to prevent their moving from side 
to side, while those possessing motion in every 
direction have generally ligaments internal to 
the capsular, as the. round ligament of the hip- 
joint, the beginning of the bicipital tendon in 
the shoulder, the perpendicular ligament of 
the processus dentatus, &c. 
BURSALOGY. 
The mucous bags, called bursae mucosae, 
are placed wherever tendons pass over each 
other, or over any solid part, and serve the 
purpose of lubricating these tendons. 
MYOLOGY. 
Of the muscles of the teguments of the cra- 
nium. 
The skin that covers the cranium is moved 
by a single broad digastric muscle, and one 
small pair. 
1. The occipito-frontalis arises from the 
transverse protuberant ridge of the os occi- 
pitis ; thence it crimes straight forwards by a 
broad thin tendon, which covers the upper 
part of the cranium at each side ; when it 
conies a's far forwards as the hair of the front, 
it becomes fleshy, and descends to be insert- 
ed into the orbicularis palpebrarum of each 
side. Its use is to pull the skin of the head 
backwards. 
2, r i he corrugator supercilii arises from the 
internal angular process of the os frontis, arid 
is, inserted into the inner and inferior fleshy 
part of the occipito-frontalis muscle. Its use 
is to draw the eyebrow of that side towards 
the other. 
Of the muscles of the car. 
The muscles of the ear may be divided into 
three classes, viz. the common, proper, and 
internal. The common move the whole ear, 
the proper only affect the particular parts of 
it to which, they are connected, and the inter- 
nal the small bones within the tympanum. 
The common muscles arc, 
1. The attollens aurem arises from the ten- 
don of the occipito-frontalis, and is insert .1 
into the upper part of the ear, opposite to 
the antihelix. Its use is to draw the ear up , 
wards. 
2. The anterior auris arise near the poste-* 
rior part of the zygoma, and is inserted inter 
a small eminence on the back of the helix. 
Its use is to draw this eminence a little for- 
wards and upwards. 
3. The retrahentes auris arises from ther 
root of the mastoid process, and are inserted 
into that part of the back of the ear which isj 
opposite to the septum conclue. Their use: 
is to draw the ear back. 
The proper muscles are, 
1. The helicis major arises from the acute- 
process of the helix, and is inserted a little 
above. Its use is to depress that part from 
which it arises. 
2. The helicis minor arises from the inferior 
and anterior part of the helix, and is inserted 
into the crus of the helix near its fissure. Its. 
use is to contract the fissure. 
3. The tragicus arises from the root of the 
tragus, and is inserted into the point of the 
tragus. Its use is to pull the point of the Ira- \ 
gus a little forwards. 
4. The antilragicus arises from the internal 
part of the antitragus, and is inserted into the 
tip of the antitragus. Its use is to turn the 
tip of the antitragus outwards. 
5. 7'he transversus auris arises from the 
prominent part of the concha on the dorsum 
of the ear ; and is inserted opposite into the 
contiguous part of the antihelix. Its use is to 
draw the parts to which it is connected to- 
wards each other. 
The muscles of the internal ear are three : 
1. The laxator tympani arises from the spi- 
nous process of the sphenoid bone, and passes 
through the fissura glass'eri to be inserted into 
the long process of the malleus. Its use is to 
draw the malleus obliquely forwards. 
2. The tensor tympani arises from the car- 
tilaginous extremity of the eustachian tube, 
and spinous process of the sphenoid bone, 
from thence running backwards through its 
osseous semicanal, it is inserted into the poste- 
rior part of the handle of the malleus. Its 
use is to pull the malleus and membrana tym- 
pani inwards. 
3. The stapedius arises from a little cavern 
in the posterior part of the tympanum, and is 
inserted into the posterior part of the head of 
the stapes. Its use is to draw the stapes 
obliquely upwards. 
Of the muscles of the eye-lids. 
The palpebrae, or eye-lids, have one muscle 
