TEETH 



247 



Fio. 196. — Dentition of the Dog [Canis familiaris). 



Fig. 197. — Dentition of the Hedgehog (Erinaceus europwus). 

 (The teeth of both jaws from the side, and those of the upper jaw from below.) 



i, incisors ; c, canines ; pm, premolars ; m, molars. 



multitubercular, having originated by the fusion of a number of simple coni- 

 cal teeth ; and certain facts in their development and the presence of multi- 

 tuberculate Mammals in the Triassic rocks, as well as a comparison with 

 the massive teeth met with in various Fishes for example, seem to sup- 

 port this view . The resulting decrease in number is compensated for by the 

 greater perfection of the individual teeth. 



