64 CICADAS — BEETLES. 



cover, and wlien a tremulous motion is imparted to the 

 wing-covers, this bar rubs against the corresponding 

 bar of the right wing-cover, and thus produces the 

 familiar chirping sound. 



The soug of the Cicadas is produced, again, in a dif- 

 ferent manner. The musical organs are internal, are 

 placed "at the base of the abdomen beneatb, and are 

 covered by two large flat plates attached behind the 

 place of insertion of the hind legs, varying in form in 

 the different species, being, in fact, the dilated sides 

 of the metasternum. . . . The sound issues out of two 

 holes beneath the above-mentioned plates, in a manner 

 somewhat analogous to the action of a violin." * 



Many beetles have special organs for the production of 

 sounds. A remarkable case is that of the so-called 

 " bombardier beetles," which, when attacked, discharge 

 at the enemy, from the hinder part of their body, an 

 acrid fluid which, as soon as it comes in contact with 

 air, explodes with a sound resembling a miniature gun. 

 Westwood mentions, on the authority of Burchell, that 

 on one occasion, " whilst resting for the night on the 

 banks of one of the large South American rivers, he 

 went out with a lantern to make an astronomical ob- 

 servation, accompanied by one of his black servant 

 boys ; and as they were proceeding, their attention was 

 directed to numerous beetles running about upon the 

 shore, which, when captured, proved to be specimens 

 of a large species of Brachinus. On being seized, they 

 immediately began to play off their artillery, burning 

 and staining the flesh to such a degree that only a few 

 specimens could be captured withthenaked hand, leaving 

 a mark which remained a considerable time. Upon ob- 



* Westwood, "Modern Classification of Insects," vol. ii. p. 42, 



