170 DIFFERENT KINDS OF TEETH, 
and in many animals (especially those of carnivorous habits) 
project far beyond the former; they are adapted not to cut 
the food, but, by being deeply fixed in it, to enable the 
animal to tear it asunder: these are termed canine teeth. 
‘The teeth of the third kind have large irregular flattened 
surfaces, and are adapted to bruise and grind the food ; these 
are called molar (or mill-like) teeth. The manner in which 
these different teeth are implanted in the jaw, varies with the 
form of their crowns, and is in accordance with their several 
uses. The incisors, ‘whose action tends as much to bury 
them in their sockets as to draw them forth, have but a single 
root or fang of no great length. The canine teeth, on which 
there is often considerable strain, penetrate the jaw more 
deeply than the incisors ; especially when they are large and 
Molars. Bicuspid. Canine.  Incisors. 
Fig. 93.—Humawn TEETH. 
long, as in the Cat tribe (fig. 94). And the molars, whose 
action requires great firmness, have two, three, or even four | 
roots or fangs, which spread out from each other; and these 
at the same time increase the solidity of their attachment to ~ 
the jaw, and prevent the teeth from being forced into their | 
sockets by any amount of pressure. z 
182. The arrangement of the dental apparétes varies, in — 
different Mammalia, according to the nature of the aliment | 
on which they are destined to feed ; and this correspondence ~ 
is so exact, that the anatomist can generally determine by the 
simple inspection of the teeth of an animal, not only the 
nature of its food, but the general structure of the body, and 
even its ordinary habits. Thus, in those that feed exclusively 
on animal flesh, the molar teeth are so compressed as to form. | 
td 
