220 M. Flourens 07i Hibernation, 



ferences of climate, upon it the seasons depend, and from it the 

 climates and seasons derive the infinite variety of vegetable and 

 animal productions, by which they are characterized and distin- 

 guished. It is not only in determining the general distribution 

 of beings upon the surface of the globe that cold acts ; it also 

 acts upon each organ, and upon each function ; it has even a 

 special or proper effect upon each of these organs and func- 

 tions. 



One of the most singular effects of cold is hibernation. This 

 name is given in natural history, to the state of torpidity and 

 lethargy in which some mammifera of our climates, the mar- 

 mots, for example, pass nearly the whole of the cold season. 

 Let one figure to himself animals, cold, insensible, incapable of 

 motion, rolled up in the form of a ball, passing three or four 

 months together without eating, drinking, or breathing, and 

 with their circulation almost stopped. Let it then be remarked 

 that these animals, subject to hibernation, differ in scarcely any 

 thing from other animals very nearly allied to them, which are 

 not subject to it ; that beside the dormouse, the lerot, the mus- 

 cardine, &c. for example, which hibernate, we find the rat, the 

 mouse, the squirrel, and twenty other animals of the same fa- 

 mily, which do not hibernate; that, on the other hand, the hi- 

 bernating animals are, as it were, dispersed, and vaguely distri- 

 buted among families 'the most unlike each other ; in those of 

 the insectivora, as the hedgehog, the bat, &c. ; in that of the 

 glires, as the dormouse, the hamster, the marmot, &c. Lastly, 

 Let it be remembered that, if in our climates it is during winter 

 that all these animals experience their lethargy, under the tor- 

 rid zone, which also has its sleeping animal, the taurec, it is, 

 on the contrary, during the period of the greatest heats, that 

 this animal becomes torpid ; and, after all this, one would still 

 have but a very feeble idea of all the curious details, and unusual 

 effects, and almost inexplicable difficulties, which this astonisli- 

 ing phenomenon presents. 



The author then gave an idea of the inquiries made with re- 

 spect to hibernation, whether with the view of determining the 

 phenomena connec ted with it, or with that of explaining them. 

 The ancients scarcely did any thing with reference to it. Pallas 

 and Spallanzani were the first who applied the method of obser- 



