86 ANIMAL INTELLIGENCE 



arrival has been a frequent subject of regret by me, as I 

 hoped to be able not only to continue the observations, 

 but to make them comparative, as it was my intention 

 to keep both under the same conditions in fact, in the 

 same cage. But the curious part remains to be told. 

 Though I kept the remaining Woodchuck under exactly 

 the same conditions as the animal I had had so long, he 

 did not hibernate for an hour the whole winter, though 

 he drowsed and slept enough. 



It has been generally considered that the hibernating 

 conditions of animals was dependent above all else on 

 the temperature of the surrounding atmosphere. My 

 experiments in bats seemed to warrant this conclusion, 

 for whenever the temperature reached the neighbour- 

 hood of 45 F. to 40 F., the other conditions being 

 favourable, my specimens began to hibernate. It was 

 also true that my Woodchuck was in the deepest sleep 

 during mid-winter when the cold is greatest. Whether 

 a bat could be put into a state of torpor during summer 

 by exposing it to a lowered temperature, I do not know. 

 However, Marshall Hall maintained that the diurnal 

 sleep of the bat (" diurnation ") was exactly the same 

 phenomenon as the winter sleep. The same writer 

 maintained that hibernating bats always awoke when 

 the temperature fell below freezing point, and his 

 observations showed that the temperature of the 

 animals was always a few degrees above that of the 

 surrounding atmosphere. Probably Hall is correct in 

 the main, for my bats, when the temperature sank 

 during the night much below freezing, were always 

 found dead in the morning. Whether they awoke first, 

 or simply passed from torpor to death, I do not know. 



However, for the Marmot, I can assert positively that 

 this rule does not hold, for frequently the water was 

 found frozen in the apa rtment in which the animal was 

 kept, yet he was undisturbed. Nevertheless, I came to 



