80 ANIMAL INTELLIGENCE 
There seems to be no doubt, however, that many 
species of fish do hibernate. Turning to warm-blooded 
animals (homoiothermers), it is thought that while the 
brown bear of Europe and the badger sleep most of the 
time in winter, they do not hibernate in the same sense 
as eg. the dormouse. The black bear is believed to 
hibernate, though definite information about the winter 
life of this creature and other American bears generally 
would be very welcome. The hedgehog is regarded as 
a true hibernater the winter long. It is known that 
the tenrec of Madagascar sleeps for three months in his 
burrow during the hottest part of the year. It is, 
however, among the rodents that we must look for the 
most perfect hibernation; and the porcupine, the 
hamster, the dormouse, the marmot—-and, as some think, 
the squirrels, are the best known examples. But if the 
hibernation of the bat is not the most perfect, it seems 
to have been about the best studied, for Marshall Hall’s 
investigations of sixty years ago are still to be regarded 
as classic. 
In consequence of reference to this subject in a 
paper on Squirrels, read before the Society in 1887, and 
my appeals for assistance in the study of this wide 
subject (in which one person can do comparatively 
little of himself, at least in ascertaining those modifica- 
tions which apply for different latitudes and conditions), 
I have been able to obtain some definite information as 
regards the winter sleep of squirrels especially. 
J. P. Bishop, Professor of Science in the State 
Normal School of Buffalo, N.Y., writes me: 
“Regarding hibernation, I seriously doubt whether the Red 
Squirrel, in the latitude of Central N.Y., ever really hibernates. 
I have seen him out at all times of the winter, and in all kinds of 
weather, even when the thermometer recorded temperatures 
below zero and the air was full of snow. But he is much more 
lively in warm days, which he prefers for feeding. The Grey 
Squirrel is more sensitive to cold, but will come out upon 
almost any warm day in the winter.” 
