HABITS AND STRUCTURE OF INSECTS. 95 



wings of such an insect, while modifying the sound, by no 

 means prevented it being made ; and it is a fact also that no 

 sound is produced by other insects whose wings vibrate with 

 great energy. 



89. The peculiar chirp of the cricket is made by the fore- 

 wings being rubbed rapidly against the hind-wings upon 

 which they rest; one of the large veins in the fore-wing 

 being thickened and notched like a file, and the wing itself 

 acting as a resonant body in augmenting the sound. The 

 males, only, make this sound ; the females are silent ; and if 

 the fore-wing of the female be examined, the vein in ques- 

 tion is not thickened, nor is it rough, like a file. 



Mr. Samuel IT. Scudder has stated that the grasshop- 

 pers produce their sound, or stridulate, in four different 

 ways : " 1. By rubbing the base of one wing-cover upon 

 the other, using for that purpose the veins running through 

 the middle portion of the wing ; 2. By a similar method, but 

 using the veins of the inner part of the wing ; 3. By nib- 

 bing the inner surface of the hind-legs agaii^st the outer sur- 

 face of the wing-covers; and 4. By rubbing together the 

 upper surface of the front edge of the wings and the imder 

 surface of the wing-covers. The insects which employ the 

 fourth method stridulate during flight — the others while at 

 rest. To the first group belong the crickets ; to the second, 

 the green or long-horned grasshoppers ; to the third and 

 fourth, certain kinds of short-horned or jumping grasshop- 

 pers." 



90. Harris, in describing the third method of stridulation, 



