STRAIGHT-WINGED INSECTS. 259 
Fig, 206.—Locust. 
ly destructive of all insects. Some species are occasion- 
ally quite destructive in some parts of this country. But 
it is in Asia and Africa that they appear in such immense 
armies, leaving not a vestige of vegetation in their track, 
eating the corn and the grass down to the roots, and 
stripping the trees of their leaves. Mr. Cumming, in de- 
scribing the flight of an army of these insects, says, “I 
stood looking at them until the air was darkened with 
their masses, while the plain on which we stood became 
densely covered with them. Far as my eye could reach, 
east, west, north, and south, they stretched in one un- 
broken cloud, and more than an hour elapsed before their 
devastating legions had swept by.” ‘These insects some- 
times make incursions into Europe. One of these is de- 
scribed by Professor Jaeger, who was an eyewitness of 
it as he was traveling in Russia in 1825.across its desert 
prairies. The carriage-wheels moved through Locusts 
piled up to the height of two feet. This state of things 
existed over a wide extent of country. The insects were 
now wingless; but the inhabitants of the fertile regions 
north feared that, as soon as their wings were grown, 
they would come north and devour every green thing. 
Before this vast insect army could do this, the Emperor 
