250 INSECT TRANSFORMATIONS. 



columns over these temporary bridges, on which they 

 even seem to rest, and enjoy the refreshing coolness. 

 Towards sun-set, the whole swarm gradually collect 

 in parties, and creep up the plants, or encamp on 

 slight eminences. On cold, cloudy, or rainy days 

 they do not travel. As soon as they acquire wings, 

 they progressively disperse, but still fly about in large 

 swarms * 



When Captains Irby and Mangles were travelling 

 round the southern extremity of the Dead Sea, in 

 the end of May, they had an opportunity of observ- 

 ing these insect depredators. " In the morning," say 

 they, " we quitted Shobek. On our way we passed a 

 swarm of locusts that were resting themselves in a 

 gully ; they were in sufficient numbers to alter ap- 

 parently the colour of the rock on which they had 

 alighted, and to make a sort of crackling noise while 

 eating, which we heard before we reached them. 

 Volney compares it to the foraging of an army. Our 

 conductors told us they were on their way to Gaza, 

 and that they pass almost annually, "t 



Even our own island has been alarmed by the ap- 

 pearance of locusts, a considerable number having 

 visited us in 1748 ; but they happily perished without 

 propagating. Other parts of Europe have not been 

 so fortunate. In 1650 a cloud of locusts were seen 

 to enter Russia in three ditFerent places ; and they 

 afterwards spread themselves over Poland and Lithu- 

 ania in such astonishing multitudes that the air 

 was darkened, and the earth covered with their num- 

 bers. Id some places they were seen lying dead, 

 heaped upon each other to the depth of four feet ; in 

 others they covered the surface of the ground like a 

 black cloth : the trees bent with their weight, and the 



* Travels in Russia, ii. 422-6. 

 •f Irby and Mangles' Travels in Eg^ypt and Syria, p. 443. 



