HEMIPTERA. 10^ 



fconvex surface are rubbed with a small body, such as a piece of 

 rolled-up paper, incapable of piercing or tearing it, it is easily made 

 to sound ; and the sound is occasioned by the portions of the kettle- 

 drum which are depressed by the friction of the 

 small body, returning to their former position as 

 soon as it has ceased to act upon them. It is 

 here that the two strong muscles act whose exis- 

 tence and use were discovered by Reaumur. 



"It is clear," says this naturalist, "that when the 

 muscle is alternately contracted and expanded with 

 rapidity, one convex portion of the kettledrum 

 will be rendered concave, and will then resume 

 its convex form by the force of its own spring. 

 Then this noise will be made, this song of which 

 we have been so long seeking an explanation, 

 because we wished to find out all the parts by 

 means of which He, who never makes anything 



without its use, willed that it should be produced." Musical iJpaJatus of the 



Let us add, to complete what we have already Male cicada. 

 said on this subject, that if the kettledrums are 

 the essential organs of the insect's song, the mirrors, the white and 

 wrinkled membranes, and the exterior shutters which cover in the 

 whole apparatus, contribute largely, as Re'aumur pointed out, to 

 modify and strengthen the sound. 



We have said above that the female Cicada does not sing ; and 

 so her singing organs are quite rudimentary. This fact, moreover, 

 has been known for ages. Xenarchus, a poet of Rhodes, says, with 

 little gallantry : — 



** Happy Cicadas ! thy females are deprived of voice !" 



Nature has indemnified the female Cicada for this privation, by 

 giving her an instrument less noisy indeed, but more useful. This is 

 a sort of auger, destined to penetrate the bark of the branches of 

 trees, and lodged in the last segment of the abdomen, which, for this 

 purpose, is hollowed out groove-wise. By the aid of a system of 

 muscles the auger can be protruded or retracted at pleasure. It is 

 furnished with three implements. In the middle there is a piercer, 

 or bodkin, which when run into a branch supports the insect, and 

 two stylets^ whose upper edges, having teeth like a saw, resting back 

 to back, on the middle implement, move up and down it. With this 

 admirable instrument the female Cicada incises obliquely the bark 

 and wood until she has almost reached ' the pith (Fig. 80). The 

 61* 



