Page:Insects - Their Ways and Means of Living.djvu/62

 organs on the sides of the body that appear to be designed for purposes of hearing. No insect, of course, has “ears” on its head; the grasshopper's supposed hearing organs are located on the base of the abdomen, one on each side (Fig. 63, Tm). Each consists of an oval depression of the body wall with a thin eardrumlike membrane, or tympanum, stretched over it. Air sacs lie against the inner face of the membrane, furnishing the equilibrium of air pressure necessary for free vibration in response to sound waves, and a complicated sensory apparatus is attached to its inner wall. Even with such large ears, however, attempts at making the grasshopper hear are never very succeasful; but its tympanal organs have the same structure as those of insects noted for their singing, which presumably, therefore, can hear their own sound productions. Not many of the grasshoppers are musical. They are mostly sedate creatures that conceal their sentiments, if they have any. They are awake in the daytime and they sleep at night—commendable traits, but habits that seldom beget much in the way of artistic attainment. Yet a few of the grasshoppers make sounds that are perhaps music in their own ears. One such is an unpretentious little brown species (Fig. 15) about seven-eighths of an inch in length, marked by a large black spot on each side of the saddlelike shield that covers his back between the head and the wings. He has no other name than his scientific one of Chloealtis conspersa, for he is not widely known, since his music is of a very feeble sort. According to Scudder, his only notes resemble tsikk-tsikk-tsikk, repeated ten or twelve times in about three seconds in the sun, but at a slightly lower rate in the shade. Chloealtis is a fiddler and plays two instruments at once. The fiddles are his front wings, and the bows his hind legs. On the inner surface of each hind thigh, or femur, there is a row of minute teeth (Fig. 15 B, a), shown more magnified at C. When the thighs are rubbed over thc edges of the wings, their teeth scrape om a sharp-edged vein indicated by b. This produces the