THE MAMMALIA— MAN AND BEASTS. 
37 
onvelopos of tlio intestinal canal differ greatly among the several quadrupeds. There 
are lateral omenta in some of tlio quadrupeds, which hybernate, such as the Polish and 
Alpine Sfarmots, in addition to the usual omenta of other quadrupeds. They arise 
from the loins, cover the sides of the abdomen, and advance nearly to its centre. 
These processes of the Peritoneum become loaded with fat. about the period that 
the animals remain torpid, and the fat is entirely expended during the time of their 
hybernation. The use of these lateral omenta is sufficiently obvious; yet it is very 
singular that other species which sleep during the winter, and are nearly allied to 
those just mentioned, such as the Garden Dormouse (Myoxus nitela) and the com- 
mon Dormouse (Myoxus aveUanarius) are destitute of them. 
L'urine, retciiue pendant qiielque temps dans unc vessie, sort, dans 
les deu-x sexes, a un tres petit nombre d’e.\ceptions pres, par les orifices 
de la generation. 
In nil the Mainmtdia [with the sole exception of the Monotremata] the 
generation is essentially viviparous. Immediately after conception, the 
fatus descends into.the Womb, surrounded with its membranes, of which 
the exterior is called the chorion, and the interior amnios. It is fixed to 
the sides of this cavity by one or more folds of vessels called the placenta, 
which establish the communication with the mother, from whom it 
derives its nourishment, and probably also its oxygenation. In the 
earlier periods of gestation, the foetus of the Mammalia possesses a small 
vessel, analogous to that which contains the yolk of the Oviparous ani- 
mals, and receiving supplies from the vessels of the mesentery in a simi- 
lar manner. 
Ils ont aussi une autre vessie exterieure, que Ton a nommee allantoide, 
et qui communique avee celle dc l’urine, par un canal appele I’ouraquc. 
La conception exigo toujours un accouplernent efiectif, od le sperme 
du male soit lance dans la matricc de la femelle. 
The young are nourished for some time after their birth by Milk, a 
fluid peculiar to this class, and produced by Mammj?, or Breasts. This 
secretion commences at the moment of birth, and continues as long after- 
W’ards as the young may require. It is from these Mammas that the class 
has obtained its name of M.vMJiii'iinES, or Ma.mmalia. This being a cha- 
racteristic peculiar to the animals composing this class, serves to dis- 
tinguish them more precisely from the remaining classes than any other 
external character. It remains, however, still doubtful whether the 
Monotremata possess nmmnite or not. 
hfockcl could find no traces of Mamtnm in tho male Ornythorynchus, hut thought 
he perceived them in the femiile. “ I detected, on the right aide of the .viidomini'il 
muscles," ho observes, “ ti smnll round mass, which at first bore the appeai-anco of a 
Vortion of intestine accidentally flushed into this situation. I was satisfied that this 
gland was a true Mamma, an ojiinion which was more forcibly impressed upon my 
mind from its slruc.liire and situation, from its marked development in the female, and 
the want of it in the male, or at least its existence in so minute a degree as to have 
hitherto eluded tho closest examination.” Oken and De niainville asserted, d priori, 
ttud without having ever examined a female Ornilhorynelms, tlial its Mamma) must 
exist, and would no doubt be discovered hereafter, on account of the very numerous 
analogies which this animal presents to the other Matnmalia. Sir Evorard Home 
describes tho Mamin.'o of the Ornithorynehtis in the Philosophical Transactions for IR02. 
On tho other hand, M. Geoffroy considers that these org.ans arc not real M:unmm, 
hut arc analogous oidy to tho lateral glands of the Museardin (^Myoxus avcllanarins.j 
Again, the Ornilhorynehus is either ovijtarous or ovo-viviparous, which properties are 
tdways connected with the absence of Mamma;, and its bill evidently appears unfitted 
for sucking ; so that, upon tho w hole, it must still be considered as doubtful whether 
those organs really perform the functions of Maniuuc. 
Although the .Alammie arc always found, with the above exception, in tho females, 
yet the males of many species tire destitute of them, as the Hamster (Cricctus vul~ 
Soris)^ and the Lemur mo/i^or, W'hilo in some others, as the Horse, they are found in 
■tu unusual situation. Tlie Mamma; arc frequently less numerous in the male than in 
the female. Milk has often been secreted in the breasts of Blen, as well as of other 
"tale animals, such as tho Goat, Ox, Dog, Cat, and Haro. Blumcnbach describes a 
he-goat which it was necessary to milk every other day for the space of a year. It is 
Very common to finil milk in the breasts of newly-born children of both sexes; and 
^hc same circumstance has likewise been observed in tho calf and foal. 
In the Oetacca and Marsupialia tho IMamma; do not project so as to form udders or 
breasts, but they lie flat under tho skin. In general the fliammni; arc very observ.ablo 
“d'y during the peiind of smdiling, at which time they are largely distended with 
■"'Ik, exciqit in those .animals having them placed upon the (dirat, when they possess 
that graceful and delicate form observable in the human female of the Caucasian race 
during the bloom of youth. It is very difficult to discover them in the Marsupiiil ani- 
"'u's, except at tho period when the young are actually contained in tho abdominal 
I’oucli of ilie female. Tlie number, as well as the position of tlio Mannuoe, varies 
greatly in different animals. It would appear that there are frequently twice .as many 
*uats as tlm number of young usually produced by each animal. Yet this rule is not 
vutliout sevend exceptions, among wiiicli may be included tlm Guinea-pig (Coma 
and Domestic Sow. Indeed it is among tlie domesticated races tliat 
lose exceptions are chiefly found. Tims, according to Iluffon, tlic mammee of tho 
‘‘Ow- vary from ten to twelve; of the Cow from four to six; of the Hat from cigiit to 
I”"' The Mare and Ewe may have from two to four, wliile tlie Ferret sometimes 
‘US three on tho rigid side, and four on the left. From these examples wo may 
ri'adiiy perceive tlmt no fixed law' is observed in the number of tlio mamma;. 
10 
OlVISION or THE CLASS MAMMALIA INTO NINE ORDEE3. 
1. Bimana — 2. Qitadrumana — 3. Carnassiers — 4. Bodentin — 5. Edentata — 
6, Marsupialia — 7. Eachydermata — 8, Rummaniia. — 9. Cetacea, 
Those variable characters, which establish the essential differences of the 
Mammalia among themselves, are derived jointly from the organs of touch 
and from those of mastication. The forms of the hands or feet chiefly 
determine the degree of their agility and dexterity, while those of their 
teeth not only correspond to the nature of their aliments, hut draw along 
with them innumerable otlier distinctions, relative to the digestive organs, 
and even to the intellectual functions. 
The degree of perfection in the organ of touch is estimated by tho 
number of the fingers, their capability of motion, and the extent in which 
tlicir extremities are enveloped in a nail or hoof. 
A Hoof which entirely surrounds that extremity of the finger nearest 
to the ground, blunts its sense of touch, and renders it incapable of 
grasping an object. 
The opposite character is found in the Nail, composed of a single 
layei', which covers the one side only of the extremity, and leaves to the 
other the' utmost sensibility of touch. 
The nature of their ordinary food is determined by the form of the 
Molae or Cheek Teeth, and this always corresponds to the mode in 
which the jaws are articulated. In order to cut flesh, the Molars must 
be serrated, or saw-like, and the ja^s united in the manner of scissors, 
which can only open and shut. On the contrary, in order to crush 
grains, it is necessary that they should have Molars with flat crowns, 
and jaws capable of moving horizontally. It is .also requisite that the 
crown of these teeth should possess that kind of inequality which the 
millstone acquires, that its substance should be of different degrees of 
hardness, and that some of its parts should wear away more rapidly than 
others. 
All animals with Hoofs [thence called Ungclated] must of necessity 
be herbivorous, that is, po.ssossed of Molar teeth with flat crowns, because 
the structure of their feet prevents them from seizing a living prey. 
It is different with those animals said to be Unguiculated, from their 
possessing Nails. They are susceptible of several varieties, and may 
partake of different species of food; but they differ still more from each 
other in the extent of motion possessed by the fingers, and the delicacy 
of their touch. There is one characteristic which exercises a mighty 
influence on the degree of their address and means of industry — that is, 
the power of opposing the thumb to the other fingers, for the purpose of 
seizing smnll objects, which constitutes it a Hand, properly so called. It 
is in Man, whose fore-e.vtremity is entirely free, and capable of being 
employed in seizing, grasping, or holding, that this power reaches its 
limit of perfection. 
These different combinations, which determine rigorously the nature 
of the different Mammalia, have given rise to their subdivision into the 
following orders: — 
THE ONGUICULATED MAMMALIA. 
1 . Bi.mana. — M an alone possesses hands solely at his fore-extremities, 
and at the same time is privileged in many other respects, so as to entitle 
him to the first place among the unguiculated animals; his lower extre- 
mities alone support bis body in a vertical position. 
2. Quadeumana. — T he order next to Man possesses hands at all the 
four extremities. 
3. Caenassiees. — T he third order has not the thumb free and oppos- 
able to the other anterior extremities. 
All the animals of the above orders possess three kinds of teeth, 
namely. Molars, Canines, and Incisors. 
4. Rodenti.a. — T lie fourth order differs but slightly in the structure 
of the fingers from tlie Carnassiers, hut it wants the Canine Teetli, and 
the Incisors are disposed in front for the peculiar kind of mastication, 
termed Gnawing. 
5. Edentata. — N ext follow those animals having the fingers very 
much confined, and deeply sunk into large nails, which are often very 
crooked. They also have the imperfection of wanting Incisors. Some 
also want the Canines, and others have no teeth at all. 
0. Maesupialia. — T his distribution of the Unguiculated animals would 
have been perfect, and might form a chain of some regularity, if Now 
llollmul [and .'America] had not furnished ns with a smidl collateral chain, 
composed of animals with I’oeches. All these genera resemble each 
other in the whole character of their organization, yet some of them 
correspond to the Carnassiors by the structure of their teetli, and the 
