Winter Sleep of Animals and Plants. 157 



open air are deftroyed by the froft when it is violent ; and 

 even fome of thofe which have buried themfelves (hare the 

 like fate. 



Plants have their winter fleep alfo ; for, during the period 

 of winter, their fap flows towards the root, and the circula- 

 tion of it, which is very flow, takes place only in the wideft 

 veflfels. Were the expanfion of the fap in winter as con- 

 fiderable as in fummer, it would burtt all the veflels on being 

 frozen. 



Several obfervers have endeavoured to prove that this 

 Angular circumftance is merely accidental ; and, indeed, no 

 difference is found in the internal organization of thofe; 

 animals which have winter fleep, and thofe which have not. 

 It is very remarkable that this property belongs in general 

 to animals of prey. As thefe have far ftronger powers of 

 digeftion, and ftronger digeftive juices, it would appear that 

 abftinence from food for feveral months would to them be 

 hardly poffible. 



The bear, the bat and the hedge-hog have winter fleep ; 

 but the white bear Was not. As the latter is lecured from 

 the cold by his long hair, he finds nourifliment in the dead 

 whales and feals which are call on fhore by the waves. 



The earth worms have winter fleep ; but aquatic worms 

 very (eldom. Infects, as well as their larvae, have winter 

 fleep. Butterflies may be often feen fluttering about in the 

 warm days of fpring, after having fpent the whole winter in 

 that condition. Amphibious animals have winter fleep, 

 thofe which live merely in the ocean excepted. 



Few birds, on the other hand, are expofed to this ftate. 

 The greater part of thefe, on the approach of winter, retire 

 to a milder climate where they can find more abundant 

 nourifliment. 



In Iceland the flieep have winter fleep, becaufe in that 

 country they are fuffered to range in perfect freedom. In 

 the winter feafon therefore they may be fcen buried under 

 the fnow and in the buflics, where it would be impofllble 

 for them to remain were they not in that condition. 



VIII, Ex* 



