320 APPENDICES. 



ming. The toes alone of the anterior feet, but the whole of the 

 under surface of the solo in the posterior, are applied to the 

 ground in walking. The awkwardness of their appearance in 

 this action is moreover heightened by the clumsiness of then* 

 figure, and by the difficulty which they seem to experience in 

 dragging after them their cumbrous tail, which is generally suf- 

 fered to trail upon the ground, but is sometimes slightl}^ elevated 

 or even curved upward, and is occasionally moved in a direction 

 from side to side. In the water, however, this member becomes 

 most useful, both as a paddle and a rudder, to urge them onward, 

 and to direct them in their course. 



It has often been questioned whether the beavers of Europe 

 and America constitute two distinct species. M. F. Cuvier has 

 lately pointed out some slight variations in the form and relative 

 dimensions of different portions of the skulls which he had an 

 opportunity of examining; but his observations cannot yet be 

 regarded as conclusive. Other naturalists again have broadly 

 maintained that the solitary and burrowing mode of life of the 

 one, and the social and constructive propensities supposed to be 

 peculiar to the other, alone afforded sufficient grounds of dis- 

 crimination between them. But numberless instances ha /e shown 

 that these differences in their modes of life are the natural results 

 of the circumstances in which the animals ai'e respectively placed ; 

 and that the habits of each, in a situation favorable to the change, 

 undergo a thorough revolution. Place the means within his reach, 

 and the constructive instinct of the solitary beaver becomes fully 

 developed; withdraw those means, and the once skillful builder 

 degenerates into a burrowing hermit. Those of Europe are, for 

 the most part, met with in the latter predicament, the neighbor- 

 hood of civilized man havipg thinned their numbers and rendered 

 their associations perilous. In America, on the contrary, they 

 form populous villages ; but only in the back and unsettled parts 

 of the country; those which are found on the confines of the 

 different settlements have precisely the same habits with the 

 European animals. 



That similar villages formerly existed in various parts of 

 Europe, and more especially in the north, we have abundant 

 proofs in the ruins of these ancient edifices. But it seems to have 

 been too hastily taken for granted that none such are to be found 

 at the present day. In the Transactions of the Berlin Natural 



