ORIGIN OF SPECIALIZED TEETH OF THE CARNIYORA. 367 



present case, the more anterior the position of the masseter muscle, 

 the more effective the canine teeth. Hence it appears that the rela- 

 tion of this muscle to the inferior dental series depended originally 

 on the use of the canines as prehensile and lacerating organs, and 

 that its insertion has advanced from behind forward in the history 

 of carnivorous types. Thus it is that the only accessible molars, 

 the fourth above and the fifth below, have become specialized as 

 sectorials, while the fifth, sixth, and seventh have, firstly, remained 

 tubercular as in the dogs, or, secondly, have been lost, as in hy- 

 enas and cats. 



