HEARING IN INSECTS. 83 



Insects of a very different order (Homoptera, 

 LEACH), but which our translators have confounded 

 with the grasshoppers, have been famous for their 

 singing from the earliest antiquity. We allude to 

 the insects which we have called tree-hoppers (Ci- 

 cadce), so remarkable for the instrument with which 

 they cut grooves in wood for depositing their eggs *. 



Under side of the cicada. P m of the cicada. 



a a, The outer drums; 6, the muscular strings; c c, the inner drums. 



Their musical organ is no less interesting, as it has 

 been described by Reaumur, whose account we shall 

 follow. It is only the male tree-hopper which is 

 musical, and for this purpose he is furnished with 

 a pair of drums, one on each side, consisting of two 

 large plates, oval or circular in some, and triangular 

 in other species, fixed to the trunk between the belly 

 and the hind legs. When this exterior membrane 

 * See Insect Architecture, p, 150, 



