TEETH 



247 



prn 



FIG. 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. 



