_ HEMIPTERA. 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 the 
furrows or its convex surface are rubbed with a small body, such as 
a piece of rolled-up paper, incapable of piercing or tearing it, it 1s 
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 
Réaumur. 
“Tt 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- 
sume 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.” 
Let us add, to complete what we have already said on this sub- 
ject, that if the kettle-drums 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 Réaumur 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 :— 

Fig. 79. 
Musical Apparatus of the 
Male Cicada. 
“‘ 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 augur can be protruded or retracted at 
