CASTOR FIBER. 



THE SECONDARY CHARACTERS. 



CASTOR. Molars to the number of four, everywhere com- 

 posed of flat crowns, with sinuous and complicated ridges of 

 enamel. Five toes to each foot, the anterior short and close, 

 the posterior longer and palmated. Tail broad, thick, flattened 

 horizontally, of an oval form, naked, and covered with scales. 



THE SPECIFIC CHARACTERS. 



CASTOR FIBER. Incisor teeth smooth, orange-colored an- 

 teriorly, white posteriorly. Fur consisting of two sorts of 

 hair, one coarse and brownish, the other downy, more or less 

 gray. About two feet long. Tail remarkable for its scaly 

 appearance. Its great breadth (often five inches) depends 

 not on the width of the caudal vertebrae, but on numerous 

 strong tendons inserted on these vertebrae. 



There is some reason for supposing that the American and 

 European beavers are distinct species. The former are for 

 the most part builders, the latter are burrowers. 



NATURAL HISTORY. 



The BEAVER is an amphibious quadruped found in the 

 northern parts of Europe and America, living on the wood- 

 ed banks of uninhabited rivers and lakes, in which situations 

 it is gregarious, and constructs its habitation with more ap- 

 parent skill than any other animal except man. The body 

 is thick, not three feet in length, and covered with short iron- 

 brown and chestnut-colored hair ; the feet are webbed, the 

 eyes small, round, and so acutely sensible of light as to re- 

 main open only in dull weather, and the ears short, hairy, 

 and so formed that the meatus is closely shut when the an- 

 imal plunges and is beneath the water. The tail is gray, and 

 about half the length of the body, flat, horizontal, scaly, with 

 that part of it only which is next to the body covered with 

 hairs. Between the anus and the external genitals are four 

 follicles, of an oblong shape, smaller above and larger below ; 

 the two smaller are filled with a fatty substance, while the 

 two larger contain each about two ounces of an oily, viscid, 

 strong-smelling substance inclosed in membranous cells, which 

 is the officinal castor. 



The general aspect of the beaver, at first view, is that of a 

 very large rat, and seen at a little distance it might be readily 



2 



