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Page:Popular Science Monthly Volume 89.djvu/889

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Popular Science Monthhj



��Great Fleas Have Little Fleas Upon Their Backs to Bite 'Em"

C^ the naturalist

��or to any one accustomed to observe Nature closely, the fact is apparent that the problems of ixistence are propor- tionately the same in c\"ery form or stratum of life. Even the common housefly, which seemingly has nothing else to do but to crawl laziK- over whatever is left uncovered and then go happily on its way, doing its best to bring about an affiliation between the clean and the unclean, occasionally meets its Nemesis in the form of a tiny crab-like creature whicii attaches itself to the fly's legs.

These little creatures are known to the scientist as pseudo-scorpions, or chelif- ers. They may sometimes be found be- tween the leaves of old books that ha^•e stood unused for a long time, and also be- neath the bark of trees and in mosses.

Although they are called false scorpions the\- resemlile the true scorpions ciosch- in general structure cxcejit for their niimii;' size. But they have no poison gland as the true scorpions have. They attach them- selves to other insects also, but they seem to be the special pest of the houseflies. Scien- tists suppose that they seize the fly's leg and hold on until the fly dies, either worried or frightened to death by the undesirable pres- ence. When the fly is dead the little creature feeds on the body.

It is interesting to watch them under the microscope. A simple hand-lens will show them up to advantage. They arc extremelv

��The tiny creature here seen un- der the microscope literally makes life an inferno for the housefly

���active, running sidewise and backwards and gj'rating in curious and amusing ways. It is easy lu imagine the annoyance it causes the fly, when one or more of the pests decide to join hands with it; for whatever other ac- ti\ities the chelifer may find it never loses its hold of what is to be its store- iiouse of food" even- tually.

For, as De Mor- gan says:

"Great fleas have little fleas upon their backs to bite 'em;

And little fleas have lesser fleas, and so ad infinitum. .And the great fleas them- selves, in turn, ha\'e greater fleas to go on; While these again, have greater till, and greater still, and so on."

���Iridescent Fish-Eggs for Table Decoration

PERSONS living on the Atlantic coast, or visiting there during the summer, often wonder at the beauty of the various "berries" on seaweeds. Many a lo\er of the seashore, and of the beautiful, has gath- ered large quantities of these varie- gated objects. They are beauti- ful when artistically arranged in a glass receptacle so as to display the various colors, but they are n(3t the fruit of a marine plant.

On the contrary they are the eggs of the eighteen-spine srulpin and of other allied \a.- rielies of sculpins, and they furnish an excel- lent example of the astonishing profusion of material with which nature works along certain lines in the propagation of species. She seems to realize that many fish are fond of these eggs and she intends that there shall be no diminution in the number of sculpins. She acts accordingly.

��The eggs of the eighteen-spine sculpin arranged in a large jar- diniere for decorative purposes

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