146 SUPPLEMENTAL HISTORY OP MAN. 



and flat surfaces vertically opposed to each other in 

 both jaws. Plates of, enamel are intermixed with 

 the bone, and it appears upon the surface in rising 

 ridges, where its hardness must greatly increase the 

 intended effect of triturating the food. In the car- 

 nivora this substance is altogether confined to the 

 surface of the teeth. 



We observe an analogy between the articulation 

 of the lower jaw and the character of the teeth in 

 these respective tribes of animals. The only motion 

 of the inferior maxilla in carnivorous species is 

 backwards and forwards, in the herbivora there is 

 besides a capacity of lateral motion, which, in the 

 others, is prevented by the rising edges of the 

 glutoid cavity. This arrangement is in precise 

 conformity with the nature of the aliment destined 

 for each, and their different modes of taking and 

 preparing it. The teeth of man resemble those of 

 the carnivora only in the fact of being superficially 

 covered with enamel. His canine not exceeding 

 the level of the others, cannot be applied to pur- 

 poses similar to those which the cuspidati of car- 

 nivorous animals are intended to execute. The 

 obtuse tubercles of the cheek teeth in man have no 

 resemblance to the pointed projections in carni- 

 vorous grinders, nor do they resemble the fiat 

 coronal surfaces of the herbivora mingled with 

 enamel. The lower jaw in man, however, has a 

 resemblance to that of the herbivorous tribes in the 

 freedom of lateral motion. 



There is a greater general resemblance in the 



