4 
MAMMALIA. 
which, the animal lives. The teeth are divided into incisors , canines, 
and molars. The last-mentioned are the most useful. In the Carni- 
vora, they are sharp, and arranged in such a manner as to act like 
the blades of a pair of scissors. In the Herbivora, they are flat and 
roughish. In the Insectivora, they are armed with little points, 
which fit into each other. The canine teeth, indispensable to the 
Carnivora for tearing up their prey, assume sometimes a consider- 
able development, and form what are called the tusks, as in the 
wild Boar and some other animals. The tusks of the Elephant are 
nothing else hut the prolongation of the canine teeth, projecting 
from the mouth. In the Whale, the teeth are replaced by flexible 
blades, furnished with hair, and fixed firmly to the jaw : these 
are called the whale-bone plates or lamince ( baleen ).* Certain genera 
of Edentata are also toothless, as the Ant-eaters and the Pangolins, 
and again the Monotremata. 
The upper maxillary bone, which forms the jaw, is immovable 
in the Mammalia. 
Whilst the aliments are undergoing mastication, they are satu- 
rated with a liquid called saliva. The apparatus which furnishes 
this liquid is composed of three glands — parotid, sublingual, and 
submaxillary. The saliva varies in its amount of development 
according to the kind of food which is taken. It is very highly 
developed in the aquatic Mammalia. 
The deglutition is effected by the pharynx and the oesophagus, 
which serve as a conduit for conveying the food into the stomach. 
All the Mammalia have but one stomach, with the exception 
of the Buminantia, which have four. The first and largest is 
called the paunch ; it occupies a great part of the abdomen. The 
food stays there but a short time, passing thence into the bonnet 
(honeycomb bag) , or second stomach. This second stomach of the 
Buminantia is a little cavity which is in front of the paunch, and 
which receives from that reservoir the alimentary matter. After 
having saturated it with the macerating juices, it sends it back 
again to the oesophagus, and thence to the mouth, in order that it 
may undergo a second mastication. The food now descends 
into the third stomach, which has received the name of feuillet, or 
leaf (many-plies), on account of the broad longitudinal folds with 
*But the foetal whale has the rudiments of teeth, each provided with its proper 
nerve and hlood-vessels ; a most noteworthy adherence to the general type. 
