230 STRUCTURE AND ADAPTATION OF TEETH 



preserved from injury, until witli unerring force 

 they are plunged into the flesh of the victim. 

 These claws are associated with powerful canine 

 teeth ; and instead of flat molars, we find laniary 

 or trenchant teeth, which are capable of cutting 

 flesh after the manner of shears. 



In the rodents, the claws differ but little from 

 those of the carnivora; but these animals are 

 destitute of canine teeth, while the incisors are 

 more fully developed, and are adapted for a pecu- 

 liar office, that of gnawing, as in the rat and 

 beaver. 



The form of the condyle is necessarily modified, 

 to admit of the diverse movements required for 

 the efficient use of these several classes of teeth. 



The digestive organs are equally connected with 

 the character of the teeth. In the carnivorous 

 mammalia, from the highly nutritious quality of 

 their food, the alimentary apparatus is very simple 

 in form, and limited in extent ; the entire intes- 

 tinal canal being not more than three or four times 

 the length of the body. But in the vegetable 

 feeders, the digestive organs exhibit much greater 

 complexity, especially in the ruminants, and the 

 alimentary canal is from twenty to thirty times the 

 length of the body. 



The upper incisor teeth of the lower animals, 

 with the exception of some of the quadrumana, 

 are implanted in the intermaxillary bones, which 

 in man are only found in the foetal stage of exist- 



