MAMMIPEROUS ANIMALS. 87? 



structure, is the teeth; by the agency of which, 

 so many important operations of this animal, are 

 to be performed. 



These, like the other animals of the same 

 order, consist only of molars or cheek teeth, and 

 incisors or cutting Teeth, between which, from 

 the absence of the Cnnines, there is necessarily a 

 blank space. The molars, which are eight in 

 each jaw, have their sutures deeply divided by 

 small ridges, which increase their capability of 

 grinding the hard substances, as wood, the bark 

 of trees, and the like, which constitute the 

 Beaver's food ; and ofgrasping them firmly when 

 conveying them from one place to another; while 

 the incisors, two above, and the same below, 

 are of a prismatic shape, running out long and 

 strong into a sharp, chisel formed edge, by which 

 the animal is enabled with wonderful rapidity 

 and effect, to gnaw through and divide those 

 trees and iheir branches used, as before stated, 

 for their food and as one of the chief materials 

 of their buildings ; and as these teeth, by con- 

 stant detrition, are liable to wear out, nature 

 has provided them with a renovating power, by 

 which the supply of new matter keeps pace with 

 the exhaustion of that already in use. 



I should not have engrossed so much of your 

 attention in detailing the structure of this animal, 

 had it not been so closely interwoven with ac- 

 tions, that have rendered the Beaver, in the esti- 



