502 NOISES OF INSECTS. 



bumile of muscles being alternatel\- and briskly relaxed and contracted, will 

 by its play draw in and let out the drum : so that its convex surface being 

 thus rendered concave when pulled in, when let out a sound will be pro- 

 duced by the effort to recover its convexity ; which, striking upon the 

 mirror and other membranes before it escapes from under the operculum, 

 will be modulated and augmented by them. I should imagine that the 

 muscular bundles are extended and contracted by the alternate approach 

 and recession of the trunk and abdomen to and from each other. 



And now, my friend, what adorable wistloin, what consummate art and 

 skill are displayed in the admirable contrivance and complex structure of 

 this wonderful, this unparalleled apparatus ! The Great Creator has 

 placed in these insects an organ for producing and emitting sounds, which 

 in the intricacy of its construction seems to resemble that which he has 

 given to man, and the larger animals, for receiving them. Here is a cochlea; 

 a vieatus ; and, as it should seem, more than one tympanum. 



I am, &c 



