LOCUSTS AND GRASSHOPPERS (ACRIDIIDsE). 89 



efficiency. The situation and structure of these sound- 

 producing instruments we will pass over for the present. 

 The stridulation, or " song," is mainly accomplished 

 by rubbing together the inner surface of the hind legs 

 and the outer surface of the tegmina or wing-covers. 

 These latter parts have considerably elevated or pro- 

 jecting veins, one of which is slightly more thickened, 

 and has a sharp rasp-like edge ; the inner face of the 

 hind thighs or femora carries a series of small bead-like 

 prominences ; by scraping these upon the rasp-like 

 surface of the veins of the wings the wing is thrown 

 into a state of vibration, and a musical, monotonous, nearly 

 uniform sound is produced. A Stenobothrus, when 

 about to stridulate, plants itself in a nearly horizontal 

 position, with the head a little elevated ; the shanks of 

 the hind legs he is apt to draw close within a groove 

 beneath the thigh, evidently made to receive it. The 

 legs are now raised and lowered with a more or less 

 regular and continued motion, the thighs being grated 

 against the firm edge of the tegmina. The wings are 

 the responsive instrument, the viol, to which the leg 

 performs the office of bow in this musical performance. 

 Every movement of the fiddle-bow produces a note, 

 the notes varying in rapidity, number, and duration in 

 different species. Few are aware that every kind of 

 grasshopper has its distinctive note ; a practised ear can 

 distinguish the song of even closely allied species. 



