Page:Popular Science Monthly Volume 92.djvu/902

 886

Something to Lose Sleep Over- Can Fish Hear ?

CAN the humble minnov/, or any of his larger brethren, hear? He has ears, but are they any use to him? Some scientists have experimented and said "Yes!" while others have experimented and said "No!" However, recent study seem to indicate that fish do hear.

Some of the fish experimented upon had their ears removed, and others had their skins made insensible. Then sounds were made in di- rect contact with the water, but without agi- tating it at all, and signs of hearing looked for. It was found that fishes are influenced by sound. One of the most peculiar and striking manifesta- tions was the fact that a fish that had had its hearing organs destroyed lost its sense of direction when swimming fast. It could swim straight slowly, but as soon as it attempted to put on speed it went round in spirals. Con- sidering that many species of fish travel considerable distances during their periods of breeding and depositing their eggs, such loss of direction would tend to make them easy prey for their enemies.

��Popular Science Monthly

���Crown of breathing hairs be- longing to Chameleon fly larva

��breeding places one observer states that he found them in a hot spring in Wyo- ming, where the water was estimated to be but twenty or thirty degrees below boiling point a decidedly close parallel to the salamander's mythical capabilities. The particular one of this family which takes such decided liberties with the pre- vailing mode of wearing one's crown, is the larva of the Chameleon fly. In his case the crown is no mere decora- tion or emblem of rank, but an essential organ in his breath- ing mechanism.

His crown consists of about thirty many- barbed hairs radiating from a central disk con- taining two perforations for the outlets of the breathing tubes. In the surface attitude the body hangs downward suspended by the crown of hairs,. which crown lies almost flat on the water forming a very shallow funnel, allowing free entrance of the air to the breathing tubes. On leaving the surface, the hairs bend inward, enclosing a glistening bubble which serves to en- close air for 'breathing, while the little creature wriggles about among the mud and debris at the bottom of the pool in

��search of food.

��Crowns On Their Tails. The Queer Forms of Some Flies

UNEASY lies the head that wears a crown," doesn't apply to the larvae of certain soldier flies; for their crowns are at the ends of their tails.

The adults (as one of our pictures shows) are rather stout-bodied, un- familiar insects, although about as many species as there are horseflies occur in this country. They frequent the flowers in marshy places and derive their name from their brilliant coloring.

The larval period of different species is passed in the earth, in damp moss, decaying wood, ants' nests, fresh and brackish water. Some are believed to be parasitic in bee hives. To add still further diversity to their choice of

��During the act of breathing the bub- ble contracts and expands. — C l e - MENT B. Davis.

���J

��In the circle, the adult Chamekciii ily. Below, two larvae, showing crown closed and open

�� �