When a male or young female hibernates it comes out of its refuge as fat as it was on entering it. The hibernation is so perfect that there is scarcely any waste of tissue, as is the case with the mother bear, whose young practically subsist on the store of fat which she laid up in the autumn.
The polar bear when about to become a mother is obliged to find a very different kind of refuge, as there are neither caves, hollow trees, or branches, and often there is nothing but ice as a resting-place and snow as a covering. So she depends for shelter upon the snow. After selecting a convenient snow-drift, she scrapes a hole in it, and suffers the snow to fall upon her as it will.
In that country, where even the human inhabitants are obliged to make their houses out of snow or perish, she is soon buried under many feet of snow. Her thick fur keeps the snow from contact with the skin, while the heat of her body gradually melts the snow away from around her, so that she lies in a sort of tent.
Now comes the question, ventilation. Were she alone all the time she would need no communication with the external air, as the hibernation would be perfect, and respiration would not be required. But her young, who do not hibernate, must breathe continually from the time of their birth, and she, being disturbed by them, is forced to breathe occasionally.
Now, it is found that when animals are buried under snow their warm breath continually ascends, and makes a passage into the air. The aperture is a very small one, but quite sufficient for the purpose; and even in our Scotch Highlands sheep are enabled to breathe in a similar manner when buried in the terrible snow-drifts, which are apt to overwhelm whole flocks at a time.—London Sunday Magazine.
ZENOBIA.
By ADA IDDINGS GALE.