HEMIPTEEA. 107 



but, on the contrary, crumpled and full of wrinkles (Fig. 79). When 

 it is touched, it is more sonorous than the driest parchment. If ihe\ c 

 furrows or its convex surface are rubbed with a small body without, \ * 

 such as a piece of paper, piercing or tearing, 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 existence 

 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 kettle- 

 drum will be rendered concave, and will then re- 

 assume its convex form by the force of its own 

 spring. Then this noise will be made, this song _, , A Fig * 79 - 



o^ o Musical Apparatus of the 



of which we have been so long seeking an ex- Male cicada. 

 planation, 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." 



Let us add, to complete what we have already said on this sub- 

 ject, 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 Reaumur 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 saw through 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 



