174 CASTOROI.OGIA. 



for certain ends. The wing of the bird and bat, the fin of the whale 

 and seal, and the differentiation in the anterior limbs of the mole, 

 the sloth, the cat and the horse, are all simply variations of the one 

 type — the hand of man. Science concerns itself in arranging in ex- 

 act order every phenomenon that comes under the observation of the 

 student, and lays before the mind an harmonious plan of all the 

 Creator's work, which must ever claim man's highest admiration. 



Before the science of Comparative Anatomy was the accepted test 

 of affinity, the attempts to arrange the Animal Kingdom into satis- 

 factory order varied continually according to the methods applied. 

 All tests were more or less superficial, and it is curious to trace the 

 shifting of some animals from group to group, as science advanced 

 and the principles of classification were more fully comprehended. 

 Thus, for example, the wolverine until very recently was classed 

 with the Ursidce — the bears — because it walked in the same man- 

 ner as a bear, that is, it was a plantigrade animal, but to-day the 

 wolverine is clearly established as a member of the Mustelidoe — the 

 weasel famil3\ 



Up to the year 1700, the beaver, so far as is known, had never 

 been submitted to the ordinary tests of anatomy or dissected to dis- 

 cover its characteristics, but in October of that year M. Sarrasin, 

 Medecin dii Roi en Canada, addressed a letter to the "Academic des 

 Sciences," giving the results of his efforts in this direction. His 

 notes were carefully recorded and very extensive, but their scientific 

 value is much impaired by the introduction of statements accepted 

 on the authority of trappers, who treated him as they have invari- 

 ably treated other enquirers. He stated that ' ' the largest beavers 

 are three to four feet long, by twelve to fifteen inches wide from 

 haunch to haunch. They weigh from forty to sixty pounds, and 

 live from fifteen to twenty years. The beaver described here was 

 caught in a small lake about twelve or fifteen miles from Quebec, 

 and weighed fifty pounds." The external features of the beaver are 

 among its chief characteristics, beginning with its wonderful teeth 

 and ending with its perfectly unique tail. The head is not unlike 

 that of the rat, though the nose is flatter and makes the head appear 



