INSECTS 



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, Trri). Each consists of an oval depression of the 

 body wall with a thin eardrumlike membrane, or tympa- 

 num, 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 successful; 

 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 muscial. 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, ox femur, there is a row of minute teeth (Fig. 

 15 B, a), shown more magnified at C. When the thighs 

 are rubbed over the edges of the wings, their teeth scrape 

 on a sharp-edged vein indicated by b. This produces the 



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