The Pine Cockchafer 



preserved, the imitation might deceive any- 

 body. 



Well, in the Cockchafer's apparatus, the 

 pad of the finger-tip and the bit of india- 

 rubber are represented by the softness of the 

 moving abdomen and the window-pane by 

 the plate of the wing-cases, a thin, rigid 

 plate eminently capable of vibration. The 

 Cockchafer's musical instrument is thus one 

 of the simplest. 



A small number of other Beetles are en- 

 dowed with the same privilege. These in- 

 clude the Spanish Copris and the truffle-eat- 

 ing Bolboceras.^ Both make a sound by 

 means of slight oscillation? of the abdomen, 

 which gently grazes the hinder edge of the 

 wing-cases. 



The Cerambyx-beetles have another 

 method, likewise based on friction. The 

 Great Capricorn, for instance, moves his 

 corselet over its junction with the thorax. 

 There is here a large cylindrical projection 

 which fits tightly into the cavity of the 

 corselet and forms a joint which is at the 

 same time powerful and mobile. This pro- 

 jection is surmounted by a convex surface, 



1 For this Beetle cf. The Life of the Fly: chap, xviii. — 

 Translator's Note. 



203 



