NATURAL HISTORY. 309 



season, they enlarge and swell to a very great degree ; 

 that they decay soon after, and are at length totally 

 effaced : the change in the bags which contain the per- 

 fume is effected more quickly, as well as more com- 

 pletely, than that of the parts of generation : they are 

 common to both sexes, and contain a very copious 

 milky substance, while the animals are hot. 



From the ondatra being a native of the same coun- 

 try with the beaver, and from its figure, its colour, 

 and its hair, they have been often compared with each 

 other. 



In disposition and instinct also, these animals bear a 

 considerable resemblance to each other. Like the bea- 

 vers, the ondatras live in society during the winter: thdy 

 form little dwellings, about two feet and a half, and 

 sometimes more, in diameter; and in these there is 

 often found an association of several families : to such 

 habitations they do not resort in order to sleep for five 

 or six months, like the marmots ; their only object is, 

 to obtain from them a shelter from the inclemency of 

 the weather : they are of a round form, and are cover- 

 ed with a kind of ceiling about a foot thick : the ma- 

 terials of which they are composed are rushes and cer- 

 tain herbs interwoven, and consolidated with some clay, 

 which they previously prepare for that purpose with 

 their feet. 



These animals breed once a year, and generally 

 produce five or six at a time. So strong are their 

 fore teeth, and so excellently calculated for gnawing, 

 that, when one of them is shut up in a box, it pre- 

 sently makes a hoie to escape through, even if the 

 wood were of the hardest kind. 



These animals are little inclined to ferocity, and 

 when taken young, are easily tamed. In the very 



