to 38 deg., are incapable of resisting the lowering
influence of cold. The fall in temperature in some is wonderful; as an
example, the high body temperature of warm-blooded animals may be said
to oscillate between 36 deg. and 43 deg. Cent. (this includes man). Experiments
made with the zizel show that during hibernation this animal's
temperature is only 2 deg. Cent., the lowest known; and a thermometer
introduced into the animal indicated the same, showing that warm-blooded
animals in hibernating become truly cold blooded animals. If a rabbit's
temperature reaches 15 deg. Cent., it will die. The germs of bryozoa or of
the fresh water sponges resist any amount of cold, but the full grown
forms die at the first cold turn. Insects are destroyed, but their eggs
live, though of the greatest possible delicacy. Salmon eggs have been
carried from this State to Australia, and there hatched. In fact, some
animals live in the ice, as the glacier flea and several others.
As it is not the direct result of extremes of heat or cold that produces
sleep, neither is the awakening from hibernation directly caused by
a rise of temperature. In experiments made upon weasels, which are
sometimes caught asleep, one came to life in about three hours, during
which the temperature of the room remained the same as it had been
during the entire hibernation, viz.
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