96 RODENTS. 



white beavers are met with. Each molar tooth has three folds of enamel on one 

 side, and one on the other ; the three folds occurring on the outer side in those of 

 the upper jaw, and on the inner side in the lower teeth. In size, the beaver is the 

 largest of all the Old World Rodents, its total length being about 40 inches, of 

 which 10 are taken up by the tail. The weight of the adult animal usually varies 

 from about 45 to 50 Ibs., but may reach as much as 60. 



European There has been much discussion as to whether the American 



and American beaver (C. canadensis) is entitled to rank as a distinct species, or 



Beavers. mer ely as a well-marked variety of the European Castor fiber ; and 



there is still a difference of opinion among zoologists on this point. That the two 



are very closely allied is admitted on all sides ; amd, although the matter is not of 



very much importance one way or the other, it is, on the whole, convenient to 



adopt the view of their specific duality. The main difference between the two 



forms is to be found in the characters of the skull ; that of the European beaver 



being relatively narrower in front, with the nasal bones extending somewhat 



SKELETON AND JAWS OF BEAVER. 



farther back than is the case with its transatlantic cousin. A large series of 

 specimens show, however, that these characteristics are liable to a certain amount 

 of variation in the two forms. 



Distribution of Owing to incessant persecution for the sake of their valuable 



the European fur, both the European and the American beaver are doomed to 

 Beaver. extinction as wild animals at no very distant date ; this fate having 

 already practically overtaken the European species, which only lingers on here 

 and there in small numbers. Formerly, beavers were widely spread over 

 Europe; and their abundance in the British Isles is attested not only by the 

 numerous remains found in the fens and cavern-deposits of England, but like- 

 wise by the number of places, such as Beaverbourne, Beverage, Beaverege, 

 Bevercater, Beverley, Beverstone, and Beversbrook, which derive their names 

 from these animals. According to the researches of Mr. J. E. Harting, it does not 

 appear that there is any historic evidence of the existence of beavers in England ; 

 but in Wales it is on record that they still lingered in Cardiganshire as late as 

 the year 1188. That they occurred in the south of Scotland is proved by the 

 occurrence of their remains, but there is no definite historic evidence of their 

 existence ; while in Ireland we have neither the testimony of their remains nor 

 of documents. 



