198 MAMMALIAN DENTITION 



are the increasing complexity of molar pattern, the molariform 

 character of the premolars, the hypsodont evolution in the 

 cheek teeth with their persistently growing roots and the rela- 

 tive narrowing of the mandible associated with mastication 

 upon one side only at once. It was the study of these features 

 which so strongly impressed Huxley and led him to declare that 

 anyone who knew the modifications which appear in the Insec- 

 tivore and Rodent dentitions kneAv also the range of modifica- 

 tion of teeth in all other mammalian orders. 



