FORMS INJURIOUS TO HUMAN INDUSTRIES 



357 



regarding such forms will give an idea of the possibilities: "In 

 countries that are liable to their visitations they have a great 

 influence on the prosperity of the inhabitants, for they appear 

 suddenly on a spot in huge swarms, which, in the space of a 

 few hours, clear off all the vegetable food that can be eaten, 

 leaving no green thing for beast or man. It is difficult for those 

 who have not witnessed a serious invasion to realize the mag- 

 nitude of the event. Large swarms consist of an almost incal- 

 culable number of individuals. A writer in Nature [Carruthers, 

 1889] states that a flight of locusts that passed over the Red Sea 



Fig. 1255. Larva and Adult Female of the Migratory Locust (Schistocerca peregrina) 



in 1889 was 2000 square miles in extent, and he estimated its 

 weight at 42,850 millions of tons, each locust weighing -^ of an 

 ounce. A second similar, perhaps even larger, flight was seen 

 passing in the same direction the next day. That such an esti- 

 mate may be no exaggeration is rendered probable by other 

 testimony. From official accounts of locusts in Cyprus we find 

 that in 1881, up to the end of October, 1,600,000,000 egg-cases 

 had been that season collected and destroyed, each case containing 

 a considerable number of eggs. By the end of the season the 

 weight of the eggs collected and made away with amounted 

 to over 1300 tons, and, notwithstanding this, no less than 

 5,076,000,000 egg-cases were, it is believed, deposited in the 

 island in 1883. When we realize the enormous number of indi- 

 viduals of which a large swarm of locusts may consist we can see 

 that famine is only a too probable sequence, and that pestilence 

 may follow as it often has done from the decomposition of the 



VOL. IV. 



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