ON THE PHYSICAL POWER OF INSECTS. 231 



he looks forward for his harvest crops, ruining his orchards, annoying his domestic 

 animals, and in the wanner latitudes not even sparing himself. It may seem 

 strange that such reasons should be brought forward to urge the necessity of our 

 making ourselves acquainted with the works of insects, but I believe it is per- 

 fectly legitimate to do so ; for it is to be remembered, that here, as elsewhere, 

 knowledge may be power, and that with the power derived from a knowledge of 

 their economy we may frequently see these destroyers overcome. 

 • In primeval forests, and in countries where vegetation remains as yet unchecked 

 by the hand of man, the labours of insects seem often as if appointed as a curb 

 on luxuriant vegetation. In Europe, and in other parts of the world under his 

 care, no such check is now needed ; nevertheless they return as originally ap- 

 pointed in the order of the universe. Their appearance is often at distant 

 intervals, and quite inexplicable ; every effort is made by the sufferers from their 

 ravages to put a stop to their devastations ; and it is only by a careful attention 

 to their economy that this can be attained. Knowing from example, as we now 

 do, how to destroy a large proportion of the eggs of the Corn Weavel, that insect 

 is no longer the dreadful scourge of the granary that it once was. 



In the vicinity of London, in St. James's and the Green Park, a few year 3 

 back, the trees were observed to be stripped of their bark ; at first some wanton 

 mischievous persons were supposed to be the cause of the injury ; the Ranger 

 launched his edicts against them, jtnd appointed a watch to lead to their detection » 

 the evil increased — in vain did the anxious watchman try to bring to light the 

 offenders ; it was not until an entomologist had explained the cause of the injury 

 and how to proceed to remove it, that the trees were restored to their wonted 

 health. It is not always, however, that the labours of entomologists in this 

 sphere have been so successful. 



A gentleman in Liverpool, well known for his zeal in this department of science, 

 has informed me of two interesting cases that have recently occurred in France 

 and Germany, where the utmost skill of the naturalists of both these countries 

 .has been baffled. The Vines of Burgundy had received much injury from the 

 attacks of the larva of a small Moth. At the urgent request of the proprietors 

 of the Vine-yards, the French government employed Professor Audouik, of the 

 Jardin des Plantes, to see if he could provide an antidote for the evil. After a 

 thorough investigation of the Vines, he found that the only mode of removing the 

 insects was by placing a number of lamps on the ground at sunset, surrounding 

 them by shallow basins of oil. The Moths, while moving about to deposit their 

 eggs, flew to the light, and were destroyed in immense numbers among the oil ; 

 still the few that escaped possessed such powers of reproduction that the damage 

 ' It to be very little alleviated. 

 The other case occurred in the Hartz Forest, in Germany. During the early 



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