248 INSECT TRANSFORMATIONS. 



the whole surface of the ground, for an area of 

 nearly two thousand square miles, might literally be 

 said to be covered with them. The water of a very 

 wide river v/as scarcely visible, on account of the dead 

 carcases of locusts that floated on the surface, drowned 

 in the attempt to come at the reeds that grew in it. 

 They had devoured every blade of grass, and every 

 green herb, except the reeds. But they are not pre- 

 cisely without a choice in their food. When they at- 

 tack a field of corn just come into ear, they first, ac- 

 cording to Mr Barrow, mount to the summit and 

 pick out every grain before they touch the leaves and 

 stem, keeping the while constantly in motion, with the 

 same intent of destruction always in view. When the 

 larvae, which are much more voracious than the perfect 

 insects, are on a march during the day, it is utterly 

 impossible to turn the direction of the troop, and this 

 seems usually to correspond with that of the wind. 

 Towards the setting of the sun the march is discon- 

 tinued, when the troop divides into companies that sur- 

 round the small shrubs, or tufts of grass, or ant- 

 hills, in such thick patches, that they appear like so 

 many swarms of bees; and in this manner they rest till 

 day-light. At these times it is that the farmers have 

 any chance of destroying them; this they sometimes 

 effect by driving among them a flock of two or three 

 thousand sheep; by whose restlessness great numbers 

 of them are trampled to death. The year 1797 was 

 the third of their continuance inSneuwberg; and their 

 increase had been more than a million-fold from year 

 to year. 



This district, however, had been entirely free from 

 them for ten years preceding their visit in 1794. 

 Their former exit was singular: ail the full grown 

 insects were driven into the sea by a tempestuous 

 north-west wind, and were afterwards cast up on the 

 beach, where they formed a bank of three or four feet 



