36 
FIRST CLASS OF THE VERTEBRATED ANIMALS. 
three compartments; the anterior portion, containing the two frontal 
bones and the ^Ethmoid; the central portion, being the Parietal bones 
and the Sphenoid; and the hinder portion, being the occipital Bone. 
Among the occipital, the two parietal, and the sphenoid, are interposed 
the Temporal bones, of which one portion properly belongs to the face. 
The bones found in the skulls of the Mammalia frequently differ in number 
from those of ]Man. In some, the sutures which are always observable in the human 
Cranium are obliterated at an early period of life, and two, three, or more bones, are 
consolidated into one. In other species, some bones which become consolidated into 
one in Man, remain during their entire lives as separate pieces. In the Elephant, 
all tlie sutures of the skull soon become united into one solid piece. 
The occipital bone is divided into four portions, during the first or 
Foetal period of life. The body of the sphenoid bone is then composed 
of two middle parts, which are themselves subdivided, so as to form 
three pairs of lateral wings. The temporal bone is composed of three 
portions; one of these serves to complete the Cranium; another to 
close the labyrinth of the Ear; while the third forms the, walls or 
parietes of the Ear-drum. These bony portions are multiplied to a still 
greater extent in the first age of the Embryo ; they coalesce more or less 
rapidly according to the species; and the hones themselves finally unite 
into one in the adult animal. 
The face in the Mammalia is essentially formed by the tw'o maxillary 
bones, between which passes the canal of the nostrils. In front of them 
are placed the two intermaxillary bones, and behind the two palate bones; 
between tliem descends the single projecting plate of the mthmoid bone, 
called the vower, and upon the entrances to the nasal canal arc situate 
the bones distinguished by the proper term nasal. To the external parts 
of its entrance are found the inferior turbinated bones; the superior 
turbinated bones, on the contrary, belong to tlie mthmoid bone, and 
are placed behind and above. 
To this complicated arrangement of the bones of the nose in the JIammalia, these 
animals owe their superiority over man in receiving impressions of odoriferous otHuvia. 
The inferior and superior turbinated bones are greatly subdivided and convoluted. . 
The obvious design of this arrangement, is to extend the surface of the pituitary 
membrane which is spread over them; and the extent of this surface is always found 
to bear a constant relation to the acuteness of the sense of smell. 
The frontal sinuses, and in general the sinuses of all the bones in tho neighbour- 
hood of the nasal cavity, are very large, which has led several eminent physiologists to 
consider them as subservient to the organ of smelling ; others consider these cavities 
to bo merely reservoirs for containing a watery fluid, which lubricates the parts 
where this sens© more especially resides. 
The Cetaceous tribes do not possess the sense of smell, nor have they any organ 
which appears capable of exercising it. The two canals which correspond to the nos- 
trils are used by the tVhale tribes for transmitting air to and from the lungs. They 
do not respire through the mouth, and the nostrils arc placed on the top of the head. 
By this arrangement they can swallow their food and keep tho mouth in water, with- 
out interrupting their respiration. 
The Jugal, or cheek-bone, unites the maxillary to the temporal bone, 
and often to the frontal. The lachrymal bone occupies the internal 
angle of the orbit, and sometimes a part of the cheek. In the embryo, 
all these subdivisions are much more numerous. The tongue in the Mam- 
malia is always fleshy, aud attached to the hyoid hone (os hi/oides'); it is 
composed of several pieces, and suspended to the cranium by ligaments. 
It is generally supposed that the sense of taste resides exclusively in the tongue ; 
but this is not strictly correct. Some substances will excite particular tastes on pass- 
ing over tho inside of the lips and fauces. Hlumenbach raoiitions that he had seen 
a man, in other respects well formed, who was born without a tongue; yet he could 
distinguish very readily the tastes of solutions of salt, sugar, and aloes, when rubbed 
on h:3 palate, and would express the taste of each in writing. Tho tongue of tho 
other Mammalia differs always from that of Man. In tho ^lonlcoy tribes it is longer 
and thinner. The entire Cat genus have horny integuments surrounding the conical 
papilla?, whicli are on tho middle of the tongue. These are small hooks or claws, 
sharp-pointed, and inflected backwards; so that when any of tho larger animals of 
this genus employ the tongue in licking tho human hand, they tear off the skin. 
Tltero does not appear to be. any conical papilla* on the tongues of tlie Cetacea. 
Cuvier was unable to discover them, even with a gUss, upon the tongues of the Dol- 
phin and Porpoise; and .John ITuntor compared the tongue of the large Whales to a 
feather-bed. Tim worm (lytta) of the dog n tongue is a tendinous bundle of fibres, 
running length-wUe under the tongue. Casserius thought that it assisted dogs in 
lapping up fluids. M'e need scarcely observe that the practice of cutting out tho worm 
aa a preventive of Hydrophobia, though sanctioned by Pliny, is an old prejudice 
long since exploded. The Edentata, such as the Ant-eater and Manis, possess a long 
worm-like tongue, which is apparently used for no other purpose than for taking up 
the food. 
Their Lungs, two in number, are divided into lobes, composed of an 
infinite number of small cells; they are always inclosed loosely in a ca- 
vity formed by the ribs and the diaphragm, and lined by t!ie pletira. 
The number of lobes in the lungs often varies in individuals of the same species, 
but in general thc’y are more numerous than in the human species. A duo proportion 
is always observed between the sue of the lungs and that of the animal, although th? 
external form of the chest would lead an observer to arrive at an opposite conclusion. 
Tho convexity of the diaphragm is not considerable, and tlie thorax is proportion- 
ately wide in species having a short chest; but, when the thorax is long, the dia- 
pliragm projects far into the chest, and the thorax is narrowed. Thus, in the rhino- 
ceros, elephant, and horse, the diaphragm passes up into the thorax, and permits the 
viscera to lie within the margin of the ribs. 
The hlammalia respire in a manner exactly resembling Man. Atmospheric air 
rushes into the cells of the lungs through the windpipe tho instant after birth; it 
is expelled and replaced by fresh air, and the action continues as long as life remains. 
Although the muscles wliich enlarge tho chest were to act with unlimited force, no 
air could enter the lungs at each attempt at inspiration, if they were of a firm and 
inelastic texture. A >*acuum would, on the contrary, be formed between the pleura 
puhnonalis or external covering of the lungs, and the pleura costalis or internal 
lining of the ribs. But the lungs are highly elastic and free in their motion, so that 
atmospheric air rushes into and dilates the cells, exactly in proportion to the expan- 
sion of the area of the chest. When any cause prevents the air from rushing into 
tho lungs, death by suffotyitlon or asphyxia is occasioned. On examination, the lungs 
are found collapsed, as during expiration ; tho right cavities of the heart, and the veins 
‘leading to them, are filled with dark blood, while the left cavities of tho heart and 
the arteries are nearly empty. In animals of the first class, which are hanged, death 
is occasioned by strangulation, and not by apoplexy, as is frequently supposed. This 
was proved by Gregory, who opened the windpipe of a dog, and passed a noose round 
his neck above the wound. The animal, when hanged, continued to five, and to 
breathe through the small aperture; but he died when tlic rope was attached below 
the wound. 31. Richerand asserts that a respectable surgeon in the Austrian army 
had informed him that ho once saved the life of a soldier by performing tho operation 
of opening the wmdpipc, a few hours before his execution. The soldier, feigning to 
be dead, was cut down, delivered over to tho surgeon for anatomization, and thus 
finally escaped. 
The glottis through which the external air rushes into the lungs, is so small that 
it may be readily obstructed when the epiglottis rises during the act of swallowing, 
and the substance swallowed may stop up the mouth of the larynx. Anacreon, tho 
celebrated poet, was in this manner suffocated by a grape seed, and Gilbert, also a 
poet, met his death in a similar manner. 
The organ of voice, in the Mammalia, is always at the superior extre- 
mity of the Trachaea or windpipe; — a fleshy prolongation, called the 
velum palati or palate-curtain, establishes a direct communication betw'een 
tlie Larynx and the back part of the nostrils. 
“ The human voice,” says Sir Charles Boll, ** commences in the Larynx, but rever- 
berates downwards into the Trachea, and even into the chest, whilst it may be directed 
with different effects into the cavities of the head, mouth, and throat. The organ of 
voice is neither, strictly speaking, a stringed instrument, nor a drum, nor a pipe, nor 
a horn, but it is all these together; and we will not be suipriscd at this complication', 
if we consider that the human voice is capable of every possible sound, that it can 
imitate the voice of every beast aud bird, — that it is more perfect than any musical 
instrument hitherto invented; — and, in addition to every vaiuety of musical note, it is 
capable of all combinations, in articulate language, to be heard in the different nations 
of the earth. The essential and primar)* parts of the organ are the vocal cords, or 
thyro-arytaRiioid ligaments. Tho membrane lining the larynx is reflected over these 
ligaments, so as to be drawn by them in their motions ; and this is what is meant when it 
is said the organ is like a drum, for those membranes must vibrato in tlie air. 1’be 
muscles of the arytaenoul cartilages draw tight the vocal cords and their attached mem- 
branes, and thus give them a certain tension ; and the air being expelled forcibly from 
the chest at the same time, they cause a vibration of these ligaments and incnibranos. 
This vibration is communicateti to the stream of air, and sound is produced. This 
sound may revorberat© along all the passages from the lungs to the nostrils; but unless 
there be a certain vibration in these cords of the larynx, there is no vocalization of 
the breath. For example, a man in whispering articulates the sounds of the mor® 
breath, without the breath being vocalized and made audible by the vibrations in the 
larynx. In singing, the vocalized bnKith is given out uninterruptedly tlirougb the 
passages, the rising notes in the gamut being produced, first, by the narrowing of tb® 
glottis, and secondly, by the rising of tho larynx towards the base of the skull. I*' 
the. graver notes, the larynx is drawn down, and the lips protruded; and in the 
higher notes the larynx is elevated to tho utmost and the lips retractetU” Tho various 
sounds emitted by different animals, to which we assign the terms roar, bray, bowb 
pm-r, scream, whistle, bark, grunt, snort, and hbs, are all caused by peculiarities 
the construction of their vocal organa, which will be explained hereafter. 
As the Mammalia [generally] reside on tho surface of the earth, wher® 
they are exposed to moderate variations of temperature, their coverinS 
ot hair is but moderately thick ; and in many of the animals inhabiting warni 
countries tliis integument is generally deficient. The Cetacea, wbid' 
live entirely in the water, are, however, the only species wherein it 
altogether wanting. 
The abdominal cavity of the Mammalia is hung round with a metn- 
brane called tile Peritoneum, and their intestinal canal is suspended to 
fold of this peritoneum, called the Mesentery, containing numerous con- 
globated glands, in which the lacteal vessels are ramified. Another pt®' 
duction of the peritoneum, called the Epiploon, liangs before and beneath 
the Intestines. 
Thp uses of these several parts are precisely the same in the other Mammalia as 
Man ; hut their form and extent depend upon tho convolutions and length vf 
intestinal canal; and therefore its reflexions, which form the omentum and tb® 
