28 



ZOOLOGY. 



ject beyond the plane of the others ; these are the canine 

 teeth. 3. Others, called molar, whose broad and inv^ular 

 surface points out their use in the trituration of the food. 



The mode of implantation of these teeth in the jaws dili'crs, 

 as wi-11 as the form of the corona, being, in fact, in accordance 

 with their uses. The incisive, intended only to cut or divide 

 the food, have but a single short root; the canine penetrate 

 much more deeply into the jaws than the incisives ; and the 

 molar, called on to undergo still stronger pressure, are firmly 

 fixed by two or three roots into the alveolar cavities. 



53. The harmony of organization between the teeth and 

 their uses is such, that in general it is easy, by a sight of 

 the teeth of an animal, to say to what class it belongs, and to 

 predict much, a priori, as to its nature. Thus, in carni- 

 vorous animals the molars are not grinding teeth, properly so 

 called, but present a sharp edge, dividing the prey like a pair 

 of scissors (Fig. 17) ; in insectivorous animals the teeth have 

 a tuberculated surface, rough, with conical points, so arranged 

 as to lock into each other. In the frugivorous, living on soft 



Fig. 17. Teeth of a Carnivorous 

 Animal. 



Fig. 18. Teeth of an Insectivorous 

 Animal. 



fruits (Fig. 20), these teeth are simply provided with rounded 

 tubercles ; in the herbivorous these teeth have a broad, rough 

 surface, resembling a millstone (Fig. 19). 



Fig. 19. Teeth of an Herbivorous Fig. 20. Teeth of a Fru- 

 givorous Animal. 



