436 ARTICULATES : INSECTS. 



enable the male to produce its music consist of a pair 

 of kettle-drums, one in each side of the abdomen, formed 

 of convex pieces of parchment finely plaited, and played 

 by means of muscular fibres fastened to the inside. By 

 the rapid contraction and relaxation of these fibres, the 

 drum-heads are alternately tightened and loosened, and 

 thus the sounds are produced ; while other cavities in the 

 body, separated by thin, transparent, and brilliant mem- 

 branes, assist greatly in increasing the intensity of the 

 sounds. The piercer of the female consists of three 

 pieces, two* outer ones grooved on the inside and toothed 

 on the outside like a saw, and a central one, a spear- 

 pointed borer, which plays between the other two. The 

 Greeks were charmed with the singing of the Cicadae, 

 and often kept them in cages, that they might enjoy 

 their music. They ate both the pupae and the perfect 

 insect. 



The Genus Cicada contains all the species, of which 

 there is a score or more in this country. 



The Seventeen-year Cicada, C. septendecim, Linn., is 



Fig. 332- 



Seventeen-year Cicada, C. septendecim, Linn. 



about an inch long, black, the wing-covers and wings 

 transparent, with the forward edges and larger veins 

 and eyes orange-red, and near the tips of the wing-covers 

 there is a dusky zigzag line. This species is popularly 

 known as the Seventeen-year Locust, a name which 

 should be at once abandoned, as the present species does 



