CHAPTER X. 



HIB E RNA TION. 



THE periodical torpor known as the winter sleep of 

 reptiles is intimately connected with respiration, and 

 a chapter must now be devoted to this subject. 



'Reptiles are obedient to the external atmosphere,' has 

 been aptly said of them. Thus, they obey the sun ; for if 

 exposed to his rays, they warm into life and activity. They 

 obey the frost ; for when exposed to its influence, their 

 functions grow feeble or fail altogether, and they succumb 

 to within a verge of lifelessness. They obey all the inter- 

 mediate variations of temperature during the changing year, 

 by displaying degrees of animation and activity responsive 

 to the degree of warmth externally which they do not 

 possess in themselves. 



Bell speaks of hibernation as ' amongst the most 

 remarkable and interesting phenomena which occur in the 

 history of animals.' It is not a state of suffering, like that 

 of a warm-blooded creature that is frozen to death ; but 

 with one common impulse, reptiles all retire, and remain 

 in an almost lifeless repose, with every function so nearly 



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