UYBERNATION. 261 



never intended that such an inference should be drawn from 

 their analogical language. The fact is, it is not known 

 precisely whether the circulation goes on or is stopped, or 

 whether the contact of air is essential or otherwise. Jt is 

 difficult to believe that all the functions as well as the 

 signs of life cease entirely ; and yet it is scarcely less so 

 to suppose that, for the space of fifteen years or more, those 

 functions could exist without some supply of food to keep 

 up the waste and secretions, however trivial, which neces- 

 sarily flow from a circulation, or without some air to purify 

 the circulating fluid. * 



If I deem it necessary to distinguish torpidity from sleep, 

 it is, perhaps, not less so to distinguish it from the state of 

 hybernation, although the phenomena of both are more 

 strictly analogous. ( Snails become torpid when the at- 

 mosphere is hot and dry ; 



" When with their domes the slow-paced snails retreat, 

 Beneath some foliage, from the burning heat ;" 



and, as often as they are unbound by the application of 

 a warm moisture, they come forth from the shell strong 

 and vigorous ; but, " intelligent of seasons," they begin in- 

 stinctively to seek hybernating quarters at a moist season 

 of the year, and before the cold has benumbed their powers ; 

 and, if roused untimely, their languid movements evidence 



* " This living principle has the singular property of remaining dormant 

 and inert for years or ages ; without, therefore, ceasing to exist. We all 

 know that seeds may be kept a long while unsown, and yet grow whenever 

 planted in a suitable soil. This, again, is like animals which have been 

 found enclosed in trees, and yet have revived. When plants are buried in 

 the ground to a greater depth than is natural to them for their proper growth, 

 they do not vegetate ; but they do not therefore die : they retain their 

 power of vegetation to an unlimited period ; and when, by any accident, 

 brought so near the surface as to suit their evolution, they begin imme- 

 diately to grow." TURNER'S Sacred History, p. 195. 



t " A very important distinction is drawn by Dr. Hall, between true hyber- 

 nation and torpor. Torpor may be produced by cold in any animal, and is 

 attended by a benumbed state of the sentient nerves, and 'a stiifened con- 

 dition of the muscles ; it is the direct product of cold. But hybernation is 

 limited to a certain number of animals ; in it sensibility and power of motion 

 remain unimpaired ; its phenomena are produced through the medium of 

 sleep. The nature of hybernation is determined in a great measure by the 

 fact, that all hybernating animals avoid exposure to intense cold, but choose 

 a retreat, make nests or burrows, and congregate at times in clusters. The 

 instinct by which the animals are led to make use of these precautions, is 

 in connection with the law, which requires that the change from the condi- 

 tion of hybernation to that of activity, shall be slow and gradual, inasmuch as 

 the state of the blood in the one condition is incompatible with the peculiar 

 power of the heart in the other." Monthly Review for March, 1833, p. 

 351. 



