CASTOROLOGIA. 37 



name ; the body is massive, the legs moderately long, the toes partly 

 webbed, and the skin is scantily covered with rough hair of a brown- 

 ish color. Its economy to man seems to be limited to the value of 

 its meat as a food supply and it is reputed to be very palatable. 



Having thus reviewed the relative qualities of those members 

 most conspicuous in the Order, we can now safely say that none is 

 so important to man, none embodies the characteristics more com- 

 pletely, and hence, among living representatives none can so well 

 sustain the claim of being the type rodent, as the Canadian Beaver. 

 In size it almost equals the largest, its "chisel-shaped incisors " are 

 perfect models, its engineering skill surpasses the marvelous, its fur 

 is most valuable, and its meat is counted a luxury. It is unique in 

 all the animal kingdom in its possession of the so called ' ' paddle- 

 shaped" tail, covered with scales instead of fur, and as BuiFon, the 

 great French naturalist, says : " If we consider the anterior parts, 

 no animal is more perfectly adapted for terrestrial life, and none so 

 well equipped for an aquatic existence, if we look only at the poste- 

 rior portions. " The contrast of the fore and hind feet is almost 

 incredible, the latter being about eight times larger than the former 

 and embodying a development peculiar alone to the beaver. All 

 these particulars will be carefully treated hereafter, meanwhile we 

 will only mention some of the varieties occasionally met with, which 

 properly, may now be considered before studying in further detail 

 the normal type. 



The tendency to discover differences, apparent or real, on which 

 to base new species, is not the highest service of the monographer ; 

 but, rather, the effort to harmonise the varieties of nature. That a 

 clearer conception may be formed regarding the terms ' ' species ' ' 

 and ' ' varieties, ' ' we will refer to the scholarly treatment given this 

 point by Dr. C. Claus. The definition of species, formerlj^ accepted 

 by investigators, was that of Linnaeus : ' ' Tot numeramus species 

 quot ab initio creavit infinitum ens, ' ' and was based on the idea of 

 "independently created units." The great lessons, however, of 

 Embryology, and the researches of Charles Darwin have made unten- 

 able any such fixed statement, and now we have a more comprehen- 



