110 STUDIES IN THE FIELD AND FOREST. 



by night, and check the multiplication of moths, 

 beetles, and other noctural insects. 



Man alone, as I have before remarked, can seriously 

 disturb the operations of nature. It is he who turns 

 the rivers from their courses, and makes the little gurg- 

 ling streams tributary to the sluggish canal. He destroys 

 the forests, and exterminates the birds, after depriving 

 them of their homes. But the insects, whose extreme 

 minuteness renders them unassailable by his weapons, 

 he cannot destroy, and nature allows them to multiply, 

 and to become a scourge to him, as if in just retribu- 

 tion for his cruelty to the feathered races who are his 

 benefactors. 



In the native wilderness, where man has not inter- 

 fered with the harmonious operations of nature, the 

 insects are kept down to a point, at which their num- 

 bers are not sufficient to commit any perceptible rava- 

 ges. The birds, their natural destroyers, are allowed to 

 live, and their numbers keep pace with the insects they 

 devour. In cultivated tracts, on the contrary, a different 

 state of things exists. Man has destroyed the forests, 

 and raised up gardens and orchards in their place. The 

 wild pasture has become arable meadow, and the whortle- 

 berry grounds have been changed into corn fields. New 

 races of beetles and other insects, which are attached to 

 the cultivatt^d vegetables, increase and multiply in the 

 same proportion. If man would permit, the birds that 

 feed upon these insects would keep pace with their 

 increase, and prevent the damage they cause to vegeta- 

 tion. But too avaricious to allow the birds to live, lest 

 they should plunder fruit enough to pay them the wages 

 for their useful labors, he destroys the exterminator of 

 vermin, and thus to save a little of his fruit from the 

 birds, he sacrifices his orchards to the insects. 



