THE ANIMAL KINGDOM. 



the teeth implanted in the premaxillary bones, which are always of a com- 

 paratively simple type, with single roots, are termed incisors. In the great 



Lower Jaw or the Gorilla. 



majority of Mammals, there are not more than three pairs of these teeth, 



although there may be four or five pairs in 

 the Pouched Mammals. The first tooth 

 in the upper jaw, which is implanted in 

 the maxillary bone, and is very generally 

 long and tusk-like, is termed the canine ; 

 this tooth being also of simple type, and 

 generally with a single undivided root. 

 Behind this come a series of, at most, four 

 pairs of cheek-teeth, which have gener- 

 ally, except the first, two roots each, and, 

 in ordinary Placental Mammals, are pre- 

 ceded (as are tlie incisors and canine) by 

 milk-teeth in the young. To these teeth, 

 whicli may be reduced to a single pair, is 

 applied the term, premolars. Behind 

 these come the true molars, which have 

 generally broad complex crowns and 

 branching roots, and are not preceded by 

 milk-teeth. In Placental Mammals there 

 are but seldom more than three pairs of 

 molars, but in Marsupials the ordinary 

 TiQ. 6.-PALATE OP THE GoRtLiA. number is four. In the lower jaw the 

 In the palate the three hindmoft teeth tooth bitnig in front of the upper canine 



are the molars, in advance of which are is the lower canine, in front of which are 



^eS E:\Te ius5<%ltnilrj,?nfrj ^}^ "'f^"-^^- I" the Placental Mammals 

 of which are the two pairs of incisors. these do not exceed three pairs, and are 



