S90 THE PHILOSOPHY 



ered with them. But this aftonifhing fecundity, and the de- 

 vaftation thefe fmall infects would unavoidably produce 

 among the vegetable tribes, is checked by numberlefs ene- 

 mies. Myriads of infedls of different clafles, of different 

 genera, and of different fpecies, feem to be produced for no 

 other purpofe but to devour the pueerons. Some of thefe 

 infedts are fo voracious, that^ notwithftanding the extreme 

 prolific powers of the pueerons, we have reafon to be fur- 

 prifed that their fpecies are not entirely anniliilated. On 

 every leaf inhabited by the puceron we find worms of differ- 

 ent kinds. Thefe worms feed not upon the leaves, but up- 

 on the pueerons, whom they devour with an almoft incredi- 

 ble rapacity. Some of thefe worms are transformed into 

 flies with two wings, others into flies with four wings, and 

 others into beetles. While in the worm-ftate, one of thefe 

 gluttonous infects will fuck out the vitals of twenty pueerons 

 in a quarter of an hour. Reaumur fupplied a fingle worm 

 with more than a hundred pueerons, every one of which it 

 devoured in lefs than three hours. 



Befide the general fyftem of carnage produced by the ne- 

 celRty of one animal's feeding upon another, there are 

 other fources of deftrudion, which originate from very dif- 

 ferent motives. Man is not the only animal who wages 

 war with his own fpecies. War among mankind, in certain 

 accidental fituations of fociety, may be produdlive, to parti- 

 cular nations or communities, of beneficial effe<SVs. But eve- 

 ry advantage derived by war to one nation is acquired at the 

 expence, and either the partial or the total ruin of another. 

 If univerfal peace could be completely eftablifhed, and if the 

 earth were cultivated to the higheft perfection, it is not pro- 

 bable that the multiplication of the human fpecies would ever 

 rife to fuch a degree as to exceed the quantity of provifions 

 produced by agriculture, and by the breeding of domeftic 

 animals, neceffary for their exigence and happinefs. But, 



