Friday, June 13, 2008

Animals That Never Sleep


According to observation by scientists, there are many creatures which live without sleep. This is the case with some members of the insect tribe, such as the mayfly, which only lives for a limited number of hours and spends its short term of a single day's existence in flying over the surface of some stream, never pausing to rest or sleep, with some fishes and with the animalculae. These last, which increase in division and subdivision so rapidly as to make their numbers almost past belief, are in ceaseless motion, never resting, and sleep, in their case would seem to he entirely out of the question.

Fishes are not generally supposed to enjoy sleep, although many species do periodically rest for about a couple of hours at a time. Experiments have shown that the salmon, pike, goldfish and angler fish do not sleep at all. Fishes have no eyelids, like the higher mammalia, and their brain is very small in proportion to their size. Animals which have no real brain cannot be said to enjoy true sleep, the chief feature of which is the cessation of automatic activity of the brain.

On the other hand, there are some animals which obtain an excessive amount of sleep, such as snails, which have been known to sleep for four years at a time. — Brooklyn Eagle.

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