DIGESTION AND ABSORPTION. 103 



Eight incisors (cutters), four front teeth above and 

 below. 



Four canines (Latin, canis, a dog), next to the incisors. 



Eight molars (Latin, mola, a mill), grinders, back 

 teeth. 



The incisors are chisel-shaped, and intended for cutting, 

 not for chewing. 



The canines correspond to the long, pointed fangs of 

 a dog, and are made for piercing and holding on to 

 things. 



The molars are broad and blunt, and are made for 

 grinding up food. 



19, The second set, the last of which do not appear before 

 the age of seventeen years, comprises 



Eight incisors, four front teeth above and below. 



Four canines, next to the incisors. 



Eight bicuspids, next to the canines. 



Twelve molars, back teeth. 



The first set come out, one by one, between the ages of 

 five and fourteen years; and the second set appear one 

 by one as the first are lost. The wisdom teeth are the 

 last to appear, at some time after seventeen years of age. 



20, Animals that live wholly on flesh, like the tiger, 

 have no grinders, but only cutting-teeth. Their jaws do 

 not move from side to side, but only up and down, like 

 shears. On the other hand, animals that live wholly on 

 vegetable food have many broad grinders, and not so 

 many cutting-teeth in proportion; and their jaws have a 

 motion from side to side, as well as up and down. Man 

 is well provided with both kinds of teeth, which goes to 

 prove that lie was made to live on both vegetable and 

 animal food. 



