574 PHYSICAL GEOGRAPHY. 



Now do the beasts groan ! 



The herds of cattle are perplexed, because they have no pasture ! 



The land is as the garden of Eden before them, and behind them a desolate wilderness !" 



Instances are numerous of extensive and dreadful devastations occasioned by the 

 multiplication and migration of the individually feeble locust. St. Augustine mentions a 

 famine in Africa, produced by the consumption of every green thing, during which 

 upwards of half a million of human beings were cut off in the kingdom of Massanissa 

 alone. In 677 Syria and Mesopotamia were overrun by these insects. In 852 immense 

 swarms took their flight from the eastern regions into the west. They destroyed all 

 vegetables, not sparing the bark of trees, or the thatch of houses, devouring the corn so 

 rapidly, that, upon computation, a hundred and forty acres in a day perished. Their 

 daily marches or distances of flight were regulated by leaders, who flew first, and settled 

 on the spot which was to be visited afterwards by the whole legion. At length, the 

 locusts were driven out to sea by the force of the wind, and died in its waters ; but being 

 thrown back by the tide upon the shores, a pestilence was caused by the offensive smell 

 from their remains. In 1271 all the corn-fields of Milan were destroyed ; and in 1339, 

 all those of Lombardy. In 1541, an incredible host afflicted Poland, Wallachia, and the 

 adjoining countries, darkening the sky with their numbers, and ravaging all the fruits of 

 the earth. A species of locust, closely resembling the Gryllus migratorius of the East, 

 appears in South America, under analogous circumstances. " We observed," says 

 Mr. Darwin, speaking of the passage of the Cordillera of Chili, " to the south a ragged 

 cloud of a dark reddish-brown colour. At first, we thought that it was smoke from some 

 great fire on the plains ; but we soon found that it was a swarm of locusts. They were 

 flying northward ; and with the aid of a light breeze, they overtook us at a rate of ten or 

 fifteen miles an hour. The main body filled the air from a height of twenty feet, to that, 

 as it appeared, of two or three thousand above the ground ; ' and the sound of their 

 wings was as the sound of chariots of many horses running to battle ;' or rather I should 

 say, like a strong breeze passing through the rigging of a ship. The sky, seen through 

 the advanced guard, appeared like a mezzotiato engraving, but the main body was 

 impervious to sight ; they were not, however, so thick together, but that they could 

 escape a stick waved backwards and forwards. When they alighted they were more 

 numerous than the leaves in the field, and the surface became reddish instead of being 

 green ; the swarm having once alighted, the individuals flew from side to side in all 

 directions. Locusts are not an uncommon pest in this country ; already, during this 

 season, several smaller swarms had come up from the south, where, as apparently in all 

 other parts of the world, they are bred in the deserts. The poor cottagers in vain 

 attempted, by lighting fires, by shouts, and by waving branches, to avert the attack." 

 The force of the wind frequently occasions the involuntary migration of insects. When 

 a strong gale blows towards the sea, and the shore is unprotected by trees, vast numbers 

 are driven to a distance from their home, either to perish in the ocean, or to gain a settle- 

 ment in some contiguous island or continental region. In this way, the dissemination of 

 the insect races has, no doubt, been largely promoted. When the Creole frigate was 

 lying in the outer roads of Buenos Ayres, in 1819, her decks and rigging were suddenly 

 covered with myriads of flies and grains of sand, which the breeze had borne from the 

 coast, and so disfigured were the newly painted sides of the vessel by the multitudes 

 adhering to them, as to require a fresh coating. A remarkable instance of an insect at a 

 distance from land was observed by the crew of the Beagle, off the coast of Africa, when 

 a large grasshopper, Acrydium, flew on board, the nearest point of land being nearly four 

 hundred miles distant. 



The class of Fishes offers many remarkable peculiarities to our notice ; and, perhaps, 



