THE HIBERNATION OF ANIMALS. 
ATURE presents no greater or 
more curious phenomenon than 
the habit of certain animals to 
conceal themselves and le dor- 
mant, in a lethargic sleep, for weeks 
and months. It is known that in per- 
fect hibernators the processes of nature 
are interrupted during the period of 
this long insensibility. Breathing is 
nearly, and in some animals, entirely 
suspended, and the temperature of the 
blood even in the warmer blooded ant- 
mals, falls so low that how life can be 
maintained in them is a great mystery. 
A variety of Rocky Mountain ground 
squirrels, when in perfect hibernation, 
says an observer, has a temperature 
only three degrees above freezing point | 
of water, and when taken from their 
burrows are as rigid as if they were not | 
only dead, but frozen. Buta few min- 
utes in a warm room will. show that | 
they are not only alive, but full of life. | 
As to the suspension of breathing in 
hibernators, the fact is proved suffi- 
ciently in the instances of the raccoon 
and the woodchuck. When they have 
laid themselves away for the winter 
sleep they roll themselves up comfort- 
ably and press their noses in such a 
position against their hinder parts that 
it would be an absolute impossibility 
for them to draw a breath. It is gen- 
erally supposed that the bear rolls 
itself up in this way and does not 
breathe, but the holes melted in the 
snow beneath which the animal fre- 
quently stows itself, under a covering 
of leaves, prove that it does breathe 
while in its lethargy. 
The marmot family produces the 
soundest winter sleepers. When the 
marmot is in its peculiar state of hiber- 
nation the electric spark will not rouse 
it. The most noxious gases do not 
affect it in the slightest. Ifits temper- 
ature is raised above that at which the 
‘animal breathed in its natural state it 
will die almost immediately. 
Our own familiar wild animals, the 
bear, the raccoon, and the woodchuck 
—the so-called ground-hog—are classed 
as perfect hibernators, because they 
store no food for winter, but have 
acquired or provided themselves with 
84 
a thick, fatty secretion between the 
skin and flesh, which, it is supposed, 
supplies them with sustenance. As a 
matter of fact, although dormant ani- 
mals absorb fat, it does not enter into 
their digestive organs. Food intro- 
duced into the stomach of a hibernat- 
ine /animal,.-of areptile, vby force or 
artificial means, will be found un- 
digested at all stages of its lethargy, 
for it invariably goes into its peculiar 
state on an empty stomach. That is 
one of the mysteries of the phenome- 
non, not so great, however, as the fact 
that bears and woodchucks produce 
their young during their winter sleep. 
The male bear is frequently roused 
from his sleep and is found by the 
woodsman roaming about in mid-winter, 
but they have never known, they say, 
a female bear to be killed after the sea- 
son for hibernation has set’ in. 
Squirrels are only partial hiberna- 
tors, from the fact that they work all 
summer and fall storing great quanti- 
ties of food to supply them when hun- 
ger wakes them up during the winter, 
some of them, no doubt, spending very 
little time in a lethargic sleep. 
The common land tortoise, no mat- 
ter where it may be, and it is a vora- 
cious feeder, goes to sleep in Novem- 
ber and does not wake up again till 
May, and that curious animal, the 
hedgehog, goes to sleep as soon as the 
weather gets cold and remains in un- 
broken slumber six months. 
Batsvdit” the ~ becinning) -on 7 cold 
weather, begin to huddle together in 
bunches in hollow trees, dark corners 
in deserted houses, and in caves and 
crevices in the rocks. They gradually 
lose all sensibility, and continue ina 
comatose state until the return of gen- 
uine warm weather. When yousee the 
first bat of the season fluttering at 
nightfall you can be sure that warm 
weather has come to stay. The little 
hooks at the end of one of the joints of 
each wing are what the bat hangs itself 
up by when it goes to sleep, whether 
for a day or for months. When the 
bats are clustering for hibernation one 
of the number hangs itself up by its 
hooks, head downward, and the others 
