364 THE POPULAR SCIENCE MONTHLY 



hibernating animal does not keep much above it, until a point is 

 reached when the animal wakens. Then its temperature rushes up 

 many degrees in a few minutes and at the same time the excretion of 

 carbon dioxide becomes enormously increased. 



Immunity and Formation of Antitoxine 



Hansmann describes the influence of temperature on the incubation 

 period and the formation of antitoxine. He found much greater resis- 

 tance to infection and lengthened incubation time and no production of 

 the various antibodies during hibernation. Blanchard and Blatin made 

 the observation that in the hibernating condition the marmot was im- 

 mune to parasitic maladies. 



Conclusion 



It may be stated and accepted that when hibernation has been fully 

 investigated, all degrees of cessation of functional activity of the vari- 

 ous organs and tissues will be found represented, from the normal sleep 

 of man and other animals to the lowest degree of activity manifested 

 in life. Though some observers claim that in true hibernation there is 

 complete cessation of function in some organs, as, for example, the 

 lungs and movements of respiration, this is extremely doubtful. The 

 awakening of an animal from its winter sleep is never sudden, but 

 slow and gradual, often lasting for hours. This gradation from a pas- 

 sive to an active condition is no doubt protective to the vital machinery, 

 as it has been noticed that when bats have been awakened suddenly they 

 have quickly died. 



We have spoken of hibernation in man, and by some authorities, 

 sleep in man is closely allied to a state of hibernation. Natural daily 

 sleep is favored by moderate exhaustion, the cravings of hunger being 

 satisfied, and the absence of all peripheral stimuli. Sleep is a rhythmic 

 diminution of the activities of all the tissues, but especially of the 

 nervous system, which has control of all the others. As we have men- 

 tioned before, Marshall Hall and others have shown that the gaseous 

 interchange in a hibernating animal is greatly lessened and so too it is 

 in sleep. It has also been shown by experiments that hibernation, like 

 daily sleep, is not a series of fixed and rigid phenomena, but is varied 

 in depth and in season and its main use is that of protecting and con- 

 serving life. 



All forms of profound winter and summer sleep are protective, both 

 of the individual and of the species. If it were not for this act of 

 hibernation, many of the mammalia, amphibia, as well as some other 

 groups of animals, would be utterly destroyed from the face of the 

 earth. 



