HYBERNATION. 125 



Two hours afterwards, having exposed it to 

 the wind, respiration became frequent and 

 painful ; it turned its back to the current, with- 

 out, however, becoming torpid. Here, then, 

 we see the difference between the torpidity of 

 hybernation, and the torpidity resulting from 

 excessive cold. In the former case, the result 

 is a renewal of health and activity — in the 

 latter, death. In the most torpid animal, during 

 hybernation, life is latent — in the animal that 

 perishes from cold, life is extinguished. Why, 

 it may be asked, do not all animals in northern 

 climes hybernate, seeing that many do ? There 

 is something, no doubt, in the constitution of 

 some animals which predisposes them to assume 

 the condition described ; and we shall find that 

 where such a constitutional predisposition is 

 given, two objects are aimed at, — preservation 

 from a degree of cold which the system cannot 

 bear with impunity, and preservation from 

 starvation in consequence of the failure of 

 natural diet. To_many animals this does not 

 apply : winter may thicken their coat, or, as in 

 the case of the ermine and the arctic fox, whiten 

 their close deep fur, but their food is as much 

 within their reach in winter as in summer, and 

 their system is adapted to sustain the utmost 

 severity of the former ; their constitution, there- 

 fore, is not predisposed to a state of torpid 

 hybernation, such a preservative not being 

 essential. If animals which naturally hyber- 

 nate in a state of torpidity be kept in an artifi- 

 cially high atmosphere, as in a warm room, 



