Page:Popular Science Monthly Volume 77.djvu/364

358 making. In Europe the hedge-hog (an insectivorous animal) is most complete. It retires to a hole among rocks, under a tangled mass of roots of trees or sometimes into an old disused drain, there it remains for the winter, seldom or never awakens until spring, and during this time it takes no food. In Canada it wakens to eat. If disturbed, it draws a deep sononous breath, followed by a few weak respiratory movements, returning almost immediately to its deep state of torpor and quiescence. The tuerec, an allied animal, found in Madagascar, sleeps similarly in its burrow for three months during the hottest period of the year.

None of the American (or European) squirrels truly hibernate except the chipmunks (Entamicæ) and the ground squirrels (spermophiles).

The dormouse hibernates in the strictest form and its torpid condition is much deeper than that of the squirrels, its favorite bed for its long slumber being an old bird's nest or a mass of dried moss or feathers. In captivity, this little animal has been known to sleep for several days during the summer. The myoxus, an allied animal, when brought to Europe from Africa, hibernated in the winter seasons as if it were its usual and natural habit, without sustaining any harm.

The hare will lie beneath deep snow for several weeks at a time, in a cavity just large enough to contain its body. In a similar manner, sheep, without any apparent injury, have been known to live for several weeks, buried in huge snow drifts or slides.

All the amphibia hibernate in cold and temperate climes. Land tortoises bury themselves in holes in the ground, while the fresh-water tortoises bury themselves in the mud at the bottom and sides of lakes and ponds. They obtain a deeper condition of torpidity than that of hibernating mammals, digestion and respiration (lung) being entirely suspended. Frogs hibernate in masses in the mud at the bottom of stagnant pools and if awakened from the hibernating state by warmth, can remain underwater, without drowning, considerably longer than they can during the breeding season. That frogs (toads?) can remain in a state of hibernation for an indefinite period remains to be proved, but too many circumstantial accounts have been reported of the discovery of live toads in masses of solid coal or rock formations to allow the idea to be dismissed as fabulous.

Reptiles, fish and batrachians exhibit little change from their usual