OF NATURAL HISTORY. 387 



withftanding the amazing deftrucSlIon of their eggs by the 

 faiallcr fry that frequent the fhores, by aquatic birds, and 

 by the larger iiflies, the numbers which efcape are fufficient 

 to fupply the ocean with inhabitants, and to afford nourifh- 

 ment to a very great portion of the human race. A cod, 

 for inftance, according to the accurate computation of Lew- 

 enhoeck, produces, from one roe, above nine miUions of eggs 

 in a fingle feafon. The flounder lays annually above one 

 million, and the mackarel more than five hundred thoufand : 

 An increafe fo great, if permitted to arrive at maturity, that 

 the ocean itfelf, in a few centuries, would not be fpacious 

 enough to contain Its animated productions. This wonder- 

 ful fertility anfwers two valuable purpofes. In the midft of 

 numberlefs enemies it continues the refpe£l:lve fpecies, and 

 furnifhes to all a proper quantity of nourifhment. 



We have thus feen that man, fome quadrupeds, fome birds, 

 and all fiflies, are carnivorous animals. But this fyftem of 

 carnage defccnds ftill lov/er. Many of the infeEl tribes derive 

 their nourifhment from putrid carcaiTes, from the bodies of 

 living animals, or from killing and devouring weaker fpecies. 

 How many flies are daily facrificed by fplders, a moft vora- 

 cious and a moft numerous tribe of infects .'' In return, fpi- 

 ders are greedily devoured by flies which are diftinguifhed 

 by the name of khnemnojis. The number of thefe ichneu- 

 mon flies is inconceivable j and, if it were not for the pro- 

 digious havock they make upon caterpillars and other infefts, 

 the fruits of the earth would be entirely deflroyed. Wafps 

 are extremely fond of animal food. They fi'equent butch- 

 ers flails, and beat off* the flefli fly, and every other infe£t 

 that reforts thither for the purpofe of depouting its eggs in 

 the meat. Butchers take the advantage of this jealous war- 

 fare. They encourage the wafps, and make centinels of 

 them, by giving them livers, which they prefer to more 

 fibrous flefli, probably becaufe they can cut livers more eafi- 

 ly with their teeth. 



