IM INSECTS INJURIOUS TO VEGETATION. 



which the insect inserts them again, and drives them down 

 deeper than before, and repeats the operation above described 

 until she has formed a perforation large and deep enough to 

 admit nearly the whole of her abdomen. The males, though 

 capable of producing sounds, have not the cymbals and tabors 

 of the crickets and grasshoppers ; their instruments may rather 

 be likened to violins, their hind legs being the bows, and the 

 projecting veins of their wing-covers the strings. But besides 

 these, they have on each side of the body, in the first segment 

 of the abdomen, just above and a little behind the thighs, a 

 deep cavity closed by a thin piece of skin stretched tightly 

 across it. These probably act in some measure to increase 

 the reverberation of the sound, like the cavity of a violin. 

 When a locust begins to play, he bends the shank of one hind 

 leg beneath the thigh, where it is lodged in a furrow designed 

 to receive it, and then draws the leg briskly up and down 

 several times against the projecting lateral edge and veins of 

 the wing-cover. He does not play both fiddles together, but 

 alternately, for a little time, first upon one, and then on the 

 other, standing meanwhile upon the four anterior legs and the 

 hind leg which is not otherwise employed. It is stated that, 

 in Spain, people of fashion keep these insects, which they call 

 grilloi in cages, for the sake of their music. Locusts leap 

 much better than grasshoppers, for the thighs of their hind 

 legs, though shorter, are much thicker, and consequently more 

 muscular within. The back part of the shanks of these legs, 

 from a little below the knee to the end, is armed with strong 

 sharp spines, arranged in two rows. These may serve as 

 means of defence, but the lower ones also help to fix the legs 

 firmly against the ground when the insect is going to leap. 

 The power of flight in locusts is, in general, much greater 

 than that of grasshoppers ; for the wing-covers, being narrow, 

 do not, like the much wider ones of grasshoppers, so much 

 impede their passage through the air; while their wings, which 

 are ample, except in a few species, and when expanded together 

 form half of a circle, have very strong joints, and are moved 

 by very powerful muscles within the chest. From the shoul- 

 ders of the wings several stout ribs or veins pass towards the 



