220 CLASS MAMMALIA. 



tives of high latitudes, while it naturally refers to climate 

 for a rapid solution of the problem, still leaves us quite in 

 the dark as to the mode of working it. However climate 

 may excite this change, there must be a predisposition in 

 the nature of the animal to the excitement, for the Variable 

 Hare, either domesticated or confined in a house, in an 

 uniform mild degree of temperature, will nevertheless as- 

 sume its white dress with the change of season, only a 

 little later than if exposed to all the severity of the cold. 

 It must be observed moreover, that in autumn, and before 

 the actual operation of the cold can have had much effect, 

 the fur seems preparing for the change, and that instead 

 of resulting from the cold, it actually anticipates the sea- 

 son, and becomes white when the cold is not greater than it 

 is in spring, and at the time when the opposite mutation 

 to its summer dress is in progress. It is said also that the 

 Emperor of China preserves them in a warm climate, where 

 they change yearly, as well as in higher latitudes. 



Pallas informs us that this animal has very warm blood, 

 and that during the severest frost the internal heat is from 

 103 to 105 degrees of Fahrenheit. 



In many parts the Variable Hares are observed to change 

 their haunts with the season, but not with regularity, or in 

 troops, or in any preconcerted manner, like many migrating 

 animals ; but they are occasionally observed, on the ap- 

 proach of winter, to quit the elevations of the northern 

 mountains, and to return there at spring. It is, however, 

 thought not to be the cold, but want of provision which 

 drives them to this change. In Greenland, however, this 

 has not been observed, but the white Hares of that country 

 are said to continue of that colour even in winter, and 

 some doubt therefore may remain whether the species be 

 in fact the Variable Hare or the common species become 

 permanently white by climate. The fecundity of the Green- 

 land species seems by no means prejudiced by the severity 



