1847.] Insects Injurious to Vegetation. 15 



prone to frequent, being more low, shady, and damp. There can 

 he no doubt, therefore, but the fly is as numerous in the hollows 

 of a grain tield, as upon its ridges; and that it is only in conse- 

 quence of the greater fertility of the former situations, that the 

 crop there is enabled so effectually to withstand this enemy. In- 

 deed, the farmers themselves, in districts where the fly has pre- 

 vailed, have all learned from experience, that it is only upon fer- 

 tile lands that it will do to sow their wheat. Hence Ezra L'Hom- 

 medieu long ago intimated that the Hessian fly on Long Island, 

 by driving the farmers to manure their lands, instead of a curse 

 had actually been a blessing. He says, " the land in Suffolk coun- 

 ty and other parts of Long Island, was easily tilled, and by con- 

 tinual cropping with wheat was so reduced, that on an average 

 not more than five or six bushels was raised to the acre. This 

 mode of husbandry was still pursued, and although tlie land was 

 gradually impoverished, the farmer found the crop, although small, 

 more than would pay for his labor and expense. The Hessian Hj 

 put an end to this kind of husbandry, and in that respect has 

 proved a blessing instead of a curse; no other way being found 

 to prevent the injury done by this insect, but by highly manuring 

 the land." [Trans. JV.Y. Soc. for Prom. Jlgric, 'Sfc, i., 57.) 

 A writer in Delaware also states that the universal predilection 

 there, w'as to have large rather than 7-ich fields of wheat; that 

 this insect was counteracting this, by compelling them to cultivate 

 less land, in order to cultivate it well; and that its tendency con- 

 sequently was, to make our population more dense, by making it 

 the interest of every n)an to own no more land than what he could 

 manure highly and till carefully. (Carey's Musettm, xi., 301.) 

 We thus have, even in the devastations committed by this destroyer 

 evident indications of that 



"All partial evil, universal good," 



which is every where manifest in the works of the Supreme Archi- 

 tect of nature. It is doubtless the additional strength and vigor 

 enjoyed by plants growing upon a rich soil, which enables them 

 to withstand the depredations of this insect. Those shoots which 

 are first sent up from a kernel of seed, are the ones which are 

 commonly attacked and destroyed, and in an impoverished soil 

 the seed itself thereupon perishes; whilst in a rich soil, its vitality 

 continues, and other shoots are sent forth by it, which grow vig- 

 orously and unmolested. In the spring attack also, the weak and 

 slender stalks growing upon a poor soil, are much more liable to 

 become broken and fail of maturing any grain, than the large, 

 robust, well nourished stalks of a fertile soil. Hence a rich soil 

 enables a plant to elaborate a sufficient amount of fluids for its 

 own sustenance, in addition to that which is abstracted from it by 



