STATE AGRICULTURAL SOCIETY. 
409 
GRAPE. LEAVES. 
veins. It first runs straight inwards, almost transversely, and 
then abruptly turning extends with a curve to the base of the 
wing, this curved portion being more slender. On the upper or 
back side of the wing this vein is pressed strongly downwards, 
whereby a furrow is formed in the surface above it. On the 
under side it stands out from the surface in bold relief, forming 
an elevated ridge. Now it is this prominent ridge which is applied 
to the inner edge of the opposite wing cover, and as it runs trans¬ 
versely it will at once be seen that when the wing covers are 
slightly spread apart and closed again, the motion will draw this 
ridge up and down against the edge to which it is applied, pre 
cisely like the bow of a violin playing upon the strings. This 
vein may therefore appropriately be named the fiddle-bow, M. 
Goureau the only one who has particularly described these parts 
in the common cricket having given to it the corresponding French 
term archet. But if this vein were smooth like the other veins 
it obviously could produce no vibration. It would be like a 
fiddle-bow when greased. On examining it therefore with a mag¬ 
nifying glass in a strong light, an appearance like that of very fine 
transverse lines may be discovered. And on being placed in a 
microscope the real structure of this part may plainly be seen. 
What at first appeared like fine transverse lines is found to be a 
regular row of little flat cogs or teeth, resembling the front teeth 
of man, but rather more broad than high and slightly narrowed 
into a neck at their bases. They are inserted at short distances 
apart, somewhat as the nails of the fingers appeal’ when the end 
of one finger is placed upon the top of another in a row. It is 
but a short portion of the most projecting part of the vein that is 
occupied by these teeth—little more than the twentieth of an inch 
in length; and in that short distance twenty-one teeth are inserted, 
with intervals between which are more than double the length of 
the teeth. The teeth do not stand perpendicular to the surface, 
but incline towards the inner margin of the wing cover, and that 
portion of the vein which is studded with them is about the tenth 
ot an inch from the inner edge. We shall now be able to under¬ 
stand the cause of the several peculiarities in the stridulation of 
this insect. It will readily be perceived that its fiddle-bow being 
ilrawn against the edge of the opposite wing cover, and the teeth 
