WINTER SLEEP OF ANIMALS. 379 



The mammalia are protected in various ways against the 

 severe winter of the higher latitudes. Although they cannot, 

 like the birds, exchange in a few days the chilly north for the 

 mildness of a southern sky, yet many of them wander at the 

 approach of the dreary season of cold and famine to a more 

 hospitable clime. Then the musk-ox leaves the naked barren 

 grounds of Arctic America for the less inclement forests ; and 

 the wild reindeer quits the flat coasts of the Polar Sea, where the 

 mosses of the tundra provided him with his summer food, to seek 

 in the thick pinewoods of Siberia a better shelter against the 

 terrible blasts of the snowstorm. 



Other quadrupeds fly from the winter into caverns or burrows, 

 where they partly live upon the provisions which an admirable 

 instinct taught them to collect during the summer, and partly 

 fall into a profound sleep, from which they only awaken at the 

 return of spring. 



What would become of the slow marmot during the winter, 

 when Alpine vegetation lies buried under a thick bed of snow, 

 if bounteous Providence had not protected it by a deep lethargy 

 both against the pangs of hunger (for its scanty pasture-grounds 

 can only provide for the summer) and the attacks of the 

 numerous enemies to whom it would infallibly have fallen a 

 prey if obliged to migrate from its mountain solitudes? 

 In early autumn it begins to excavate its winter dwelling, 

 into which it retires with its whole family after the first snow- 

 fall; and, after having closed the opening from within with 

 stones, earth, and moss, lies down for its long rest of many 

 months. 



By a most admirable ordination of Providence its life is now 

 reduced to the lowest ebb, that it may be preserved from total 

 extinction. Its respiration becomes so slow that, during its six 

 months of sleep, it draws its breath less frequently than during 

 two days of its active existence, so that the fat which, during 

 the abundance of summer, had collected upon its bones, suffices 

 to keep up the glimmering spark of life. The palpitation of 

 the heart is scarcely perceptible ; the temperature of the body 

 sinks to a few degrees above the freezing-point; the limbs are 

 stiff, and almost totally insensible to injury. 



Thus in their deep burrows, imbedded in soft hay, the 

 marmots remain from October to the end of April, when they 



