408 ANNUAL REPORT OF NEW-YORK 



GRAPE. LEAVES. 



pect their note to be produced in the same manner. We how- 

 ever find that in this as in so many other points they are related 

 to the crickets. And when we come to examine their wing 

 covers, we are able to discover the very curious apparatus by 

 which their stridulation is produced; and we find a peculiarity in 

 its structure wliich at once explains why it is that the song of 

 this insect consists of a single note always followed by a full 

 pause or total cessation of the sound, instead of being continuous 

 or nearly so as it is in other crickets. 



In the males the wing covers are flat and placed horizontally 

 upon the back, with their outer third turned perpendicularly 

 downwards and covering the sides. They are very thin and 

 transparent, like clear glass, and may be compared to a window, 

 with the veins like the sash dividing them into a number of panes 

 or cells of various sizes and shapes. The four largest of these 

 cells are placed in the disk or middle part of the wing, and are 

 divided from each other by three straight veins, crossing the wing 

 obliquely, the two hind ones parallel with each other, the forward 

 one meeting these at a right angle and forming with them the 

 likeness of a very full-faced letter V impressed transversely. They 

 thus resemble stout braces so placed in the wing as to keep the 

 ribs and other longitudinal veins pressed asunder, hereby put- 

 ting on the stretch the delicate membrane which forms the panes 

 between the several veins. Thus each of these panes is like the 

 head of a little drum or tabor, and when played upon, all vibra- 

 ting at the same instant produce the one shrill note which this 

 insect utters. And to augment the sound still more, it may be 

 observed that the membrane forming each one of these panes is 

 not a simple smooth surface, but is striated with numerous little 

 elevated lines. 



It now remains for us to describe the curiously constructed 

 instrument by which all these little tabrets are excited into vibra- 

 tion. On the inner margin of the wing cover, at the anterior end 

 of the V-like mark above described, will be seen a small thickened 

 or callous-like spot from the fore part of which four veins extend 

 to the base of the wing. The inner or hindmost one of these is 

 the most thick and stout, and when particularly inspected it is 

 found to be in several respects different from all the rest of the 



