MECHANISM OF INSECT MUSIC. 219 



But besides the sensations of involuntary pleasure which 

 we have often owed, without knowing it, to Insect Minstrelsy, 

 it affords (though on this subject few perhaps ever think) 

 matter for thought-inquiry, concerning the way in which it is 

 produced. It is all of an instrumental and not vocal cha- 

 racter ; and, among the varied mechanisms of natural ob- 

 jects, the instruments of sound furnished to insect musicians 

 are none of the least curious. 



That of the celebrated Cicada (the classic lyre-player) an 

 insect rarely seen in England, but still common in the south 

 of Europe, consists, as described by Eeaumur, of a pair of 

 drums fixed one on each side of the trunk ; these are covered 

 on the exterior of two membranaceous plates, usually circular 

 or oval ; and beneath them is a cavity, part of which seems 

 to open into the belly. These drums form however but one 

 portion of a compound instrument ; for besides these, there is 

 attached to another drum-like membrane in the interior a 

 bundle of muscular strings ; on pulling which, and letting 

 them go again, a sound can be produced even after the ani- 

 mal's death. For the issue of this sound a hole is expressly 

 provided, like the sound-hole of a violin, or the opening in 

 the human larynx. 



The chirp of the cricket, both of house and field, is said, by 

 Kirby, to be produced by the friction of the bases of the 

 tegmina, or wing-cases, against each other, at their base ; but 

 these insects are also provided with their drums. In the 



