9S LECTURE III. 



Beavers seem to forget their usual oeconomy, and 

 live in a less regular stile, straying about, and ap- 

 pearing to have merely a few common holes in 

 the banks of the waters they frequent. It has 

 been said that the Beaver fed entirely on fish; 

 and the Count de Buffon, who delighted in such 

 speculations, fancied this kind of diet to have 

 been originally the cause of the flattened, scaly, 

 and fish-like appearance of the tail of the animal; 

 the organic particles of its fishy food having at 

 length impressed on the Beaver something of a 

 fishy form. It seems, however, pretty generally 

 agreed that the principal food of the Beaver is of 

 a vegetable nature. 



From the Beaver is obtained the celebrated 

 drug called Castor, which is the product of a par- 

 ticular gland, and is taken from the animal imme- 

 diately after killing it : it is one of the strongest 

 or most fetid of all animal substances, and is of 

 very considerable use in medicine. 



Linn^us comprized a large tribe of animals be- 

 longing to the Order Glires, under one extremely 

 numerous genus entitled 3IUS3 or Mouse, or Rat : 

 but the genus was by this rendered too extensive; 

 and as many of the species admitted into it were 



