GREEN GRASSHOPPERS (LOCUSTID^). 147 



Musical Organs and Music. 



The Locustidse are famed for their musical powers. 

 Among them, the stridulating apparatus, when present, 

 is always situate on the base of the wing-covers. The 

 left-hand tegmen has a roughened portion on the inner 

 surface, serving as a file or bar, the right tegmen has a 

 sharp edge on its inner margin ; and by rubbing the 

 base of one wing-cover upon the other, and vibrating 

 them rapidly, a musical sound, or stridulation, is pro- 

 duced. The extent of the delicate vibrating membrane 

 of the wings which is brought into action is small, and 

 when the tegmina are very rudimentary in size, it is 

 these fields indispensable for stridulation that are pre- 

 served. With but few exceptions, the males alone 

 are provided with organs of stridulation ; in the tribe 

 Ephippigerides they exist in both sexes. 



There is much variety in the structure. In this por- 

 tion of the tegmina, the nervures not only differ in the 

 male from those of the female, the arrangement of the 

 nervures in the male is not symmetrical in the two teg- 

 mina. On the right tegmen is usually a small plate, or 

 space, formed by a slender, tightly stretched, hyaline 

 membrane, which, being put into vibration, probably 

 increases the sound. In our large Green Grasshopper, 

 Locusta viridissima, though the musical organs are by 



