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have caused. As far back as the time of Moses their ravages are mentioned, for one of 

 the plagues brought upon Egypt just before the departure of the children of Israel was 

 the plague of locusts. In Asia, Africa and Europe their invasions have been recorded in 

 history, both ancient and modern. To show the magnitude of the effects consequent on 

 their migrations, I give a few instances, as taken by Dr. Packard from different historical 

 sources. The first account, after Joel in the Bible, whose descriptions apply to Egypt, 

 Syria, Palestine and Asia Minor, is the statement of Orosius that in the year of the world 

 3800 certain regions of North Africa were visited by monstrous swarms ; the wind blew 

 them into the sea, and the bodies washed ashore " stank more than the corpses of a hun- 

 dred thousand men." Another locust plague, resulting in a famine and contagious dis- 

 orders, according to St. Augustine, occurred in the kingdom of Masinissa, and caused the 

 death of about 800,000 persons. Pliny states that the locusts visited Italy, flying from 

 Africa. In Europe locust invasions have been recorded since 1333, when they appeared 

 in Germany. Mouffit states that in 1478 the country about Venice was invaded, and 

 30,000 people died of famine. In France swarms appeared at the close of the Middle 

 Ages. In 1747 there was a great invasion of Southern and Middle Europe. Before and 

 after this date vast swarms were observed in Asia and Africa. In Russia, whose southern 

 plains form the home of the locust, vast numbers have often appeared and done great 

 damage. In China records exist of the appearance of these insects in devastating numbers 

 173 times during a period of 1,924 years. The three great causes of famine in China are 

 placed as flood, drought and locusts. 



The new world has also its migratory locusts, equally destructive with those of the 

 old. The Pocky Mountain locust, of which we all have heard so much, is not the only 

 species. Central and South America have also their peculiar locust. Their ravages have 

 been noted by the old Spanish chroniclers of Mexico and the adjacent countries from the 

 time of the first conquest. In 1632 parts of Mexico were overrun with them, and in 1738 

 and '39 there was an invasion by them of the coasts of Oaxaca, after which a famine 

 occurred in Yucatan. In 1855 and '56 Honduras and Guatemala were invaded, and a 

 famine and pestilence of fever followed. And in 1835 Chili and the eastern part of South 

 America were infested with vast swarms of locusts. 



The Pocky Mountain locust ( Caloptenus spretus ) having been a subject of observa- 

 tion by the most eminent Entomologists of the United States, we know more about its 

 habits and economy than about those of any other species. The terrible devastations it 

 has committed in the Western States have led to this result. When an insect destroys 

 the crops in one year to the estimated value of $45,000,000, it is about time to study its 

 history and habits. Mr. Piley has published a most interesting book on the subject, and 

 from this I have culled a few of the most striking items. Its home is on the elevated 

 plateau of the Pocky Mountains, whence it migrates in favourable seasons to the west 

 and south for hundreds of miles, laying waste the crops wherever it alights and doing 

 terrible damage. It breeds in the regions to which it migrates, and the next generations 

 migrate again north and west towards the "metropolis" of the species, and gradually die out 

 on the way, while those that remain in the place of their birth also die out, so that the species 

 becomes extinct in these localities in a few years. 



The observations made, so far, give no special reasons for these migrations, unless it 

 be the unusual abundance of the species and the consequent scarcity of food in its native 

 regions. One or two favourable seasons cause the insect to increase to an immense ex- 

 tent, and when they find the supply of food failing them, they mount into the air in count- 

 less millions, and, favoured by a westerly or north-westerly wind, sail off towards the set- 

 tlements in search of " fresh fields and pastures new." Such is the principal reason given 

 by Packard, though he says possibly the reproductive instinct may also be concerned. 

 And he does not think that these movements can be the result of a real migratory instinct, 

 because their migrations (as well as those of the locusts of the old world) are periodical, 

 / long intervals sometimes existing between them, so that the development of a migratory 

 instinct would be impossible. If once partially implanted, the long succession of non- 

 migratory years would effectually break up the germs of such an instinct. 



Another curious fact in connection with these locusts is, that the generation born in 

 the region to which the species has migrated the previous year, shows a tendency to return 



