106 CLASS MAMMALIA. 



lished respecting the dikes and huts which it constructs, 

 and the means it adopts in its operations. These histories 

 have, at times, been carried to such a degree of exaggera- 

 tion as to set the Beaver next to man in the degrees of in- 

 telligence. It would appear, however, that though a very 

 considerable degree of sagacity cannot be denied to this 

 animal, yet that the most wonderful of its operations are 

 referable to instinct rather than to reason. The best proof 

 of this is, that, exclusive of such operations, the Beaver 

 discovers no degree of intelligence at all approaching to 

 that of the higher quadrupeds. 



The subdivision Ondatra, including but a single species, 

 has much affinity with the Castor, particularly in its habits ; 

 its organization indeed rather approximates it to the Rats. 

 Accordingly we find that Linnasus, in the 12th edition of 

 his System, associated it with Castors, while his editor, 

 Gmelin, transferred it to the Rats. 



M. Sarrasin, in the memoirs of the French Academy of 

 1725, and from him Buffon, have given us some interesting 

 details of this animal as a species of Rat. Modern systematic 

 zoologists have employed the physical characters, princi- 

 pally of its teeth and tail, to separate it into a distinct di- 

 vision, which Lacepede and Geoffrey have called Ondatra, 

 and Cuvier and Illiger, Fiber. 



The teeth of this subdivision are incisors §, and cheek- 

 teeth |£. The anterior paws have four toes, the posterior 

 five ; these are deeply cleft, and are furnished on each side 

 with rough hairs, acting like the web of other aquatic ani- 

 mals, though less perfectly in swimming. The tail is long, 

 and compressed laterally, indicating aquatic facilities. 



The Ondatra is about the size of a small rabbit, stands 

 very low, and weighs about three pounds. The fur is as 

 fine as that of the Castor, with a thick and soft down un- 

 derneath. The head is rather short, the eyes large, and 

 the ears short and round, 



