AkCTOMVS MONAX. 146 



placed again in its box, where it went to sleep, as soundly as ever, 

 until spring made its appearance. That season advancing, and 

 the trees showing- their leaves, the Wood-Chuck became as brisk 

 and gentle as could be desired, and was frequently brought into 

 the parlour. The succeeding winter this animal evinced the same 

 dispositions, and never appeared to suffer by its long sleep." * 



In Rensselaer Count)' in this State, during the summer of 1814, 

 Dr. Bachman marked a burrow that he knew to be inhabited by a 

 pair of Woodchucks. Early in Noveml^er he had it opened 

 and found the animals l>'ing close together in a nest of dry 

 grass about twenty- five feet (7.62 metres) from the entrance. 

 " They were each rolled up," he writes, " and looked somewhat 

 like two misshapen balls of hair, and were perfectly dormant." f 



In hibernation the temperature of the animal approximates that 

 of the surrounding atmosphere, the heart's action slackens, and 

 respiration can only be detected by means of delicate instruments 

 devised for the purpose. This latter fact was known to Spallan- 

 zani nearly a hundred years ago, for he wrote to vSenebier : " You 

 will remember about my Marmot which was so exceedingly lethar- 

 gic in the severe winter of 1795 ; during that time I held him in 

 carbonic acid gas for four hours, the thermometer marking -12^, he 

 continued to live in this gas which is the most deadly of all . . . 

 at least a rat and a bird that I placed with him perished in an 

 instant." 



It is well to observe that different animals exhibit in different 

 degrees the physiological process of hibernation ; and that this 

 fact is amply illustrated by the representatives of the family to 

 which the present species belongs. Animals that are able to pro- 

 cure subsistence in the winter season, and those that lay up large 

 stores in their nests, do not sleep so continuously, and their leth- 

 argy is not so profound as in the case of those species that are 



* Quadrupeds of North America, Vol. I, 1846, pp. 20-21. 



f Il)id., p. 22. 



