384 THE PHILOSOPHY 



the flelh fly, and every, other inkQ. that reforts thither for the pur- 

 pofe of depofiting its eggs in the meat. Butchers take the advan- 

 tage of this jealous warfare. They encourage the wafps, and make 

 centinels of them, by giving them Hvers, which they prefer to more 

 fibrous flefh, probably becaufe they can cut liveis more eafily with 

 their teeth. 



The libella, dragon, or lady-fly, is well known by the beauty of 

 its colours and the fymmetry of its form. For thefe external qua- 

 lities it has received the appellation of lady-fiy. Its difpofitions and 

 its mode of life, however, are more ferocious and warlike than thofe 

 of the Amazones. Like birds of prey, they hover about in the air, 

 for the fole purpofe of devouring almoft every fpecies of winged 

 infed. They accordingly frequent marlhy grounds, pools of wa- 

 ter, and the margins of rivers, where infe6ls moft abound. Their 

 appetite is fo grofs and voracious, that they not only devour fmall 

 flies, but even the large flefh- fly, moths, and butterflies, of every 

 kind. 



It has been often faid, that no animal fpontaneoufly feeds upon 

 its own fpecies. This remark has probably been intended as an apo- 

 logy for, or at leaft a limitation to, the general fyftera of carnage 

 eftabliflied by Nature. But the obfervation, whatever might have 

 been its intention, is'unhappily a refult of ignorance; for fome qua- 

 drupeds, all fifhes, and many infeds, make no fuch dilcrimination. 

 The weaker are uniformly preyed upon by the ftronger. Reaumur 

 put twenty of thofe caterpillars which feed upon the leaves of the 

 oak into a vial. Though he regularly fupplied them with plenty of 

 frefh oak leaves, he obferved that the number of dead ones daily in- 

 creafed. Upon a more attentive examination into the caufe of this 

 mortality, he found, that the ftronger attacked with their teeth, kill- 

 ed, fucked out the vitals of their weaker companions, and left no- 

 thing 



