g6 THEPHILOSOPHY 



for a fait fo uncommon, till farther difcoveries (hall be made In the 

 hiftory of thefe furprifmg animals. What is ftiil more fingular, 

 after the caterpillars are transformed into the chryfalis ftate, the 

 neuters are inceflantly and anxloufly employed in preferving the 

 chryfales from humidity when the weather is wet, and in expofing 

 them to the warmth of the fun when it is fair, Thefe chryfales 

 are larger than the animals themfelves, and yet they carry them off 

 with eafe and rapidity. 



The Jixth order of infeds is termed dlptera, or two-winged In- 

 fedts. The difFerent fpecies of this order, befide wings, are furnifh- 

 ed with what is called a halter, or z. poifer, which is fituated under 

 each wing, and is terminated by a capitiilum, or knob. This order 

 comprehends ten genera and a multitude of fpecies. The caterpil- 

 lars of the oeftrus, or gad-fiy, lie concealed in the fkins of cattle, 

 where they are nouriftied during the whole winter. The perfe£l 

 infeds are frequent wherever horfes, cows, or fheep, are grazing. 

 Some of them depofit their eggs in the fkins of cows or oxen ; 

 others depofit them in the Inteftines of horfes, to which they get 

 accefs by the anus; and others in the noftrils of fheep. In thefe 

 habitations, the caterpillars refide till they are full grown, when they 

 throw themfelves down to the earth, and generally pafs the chryfa- 

 lis flate under the firfl: ftone they meet with. — The mufca, or com- 

 mon J?)'; The mouth of this infedl confifts of a foft, flefhy probof- 

 eis, with two lateral lips. The caterpillars of fome of this genus 

 devour the pucerons ; others confume all kinds of putrid flelli ; 

 others are found in cheefe ; others in the excrements of different 

 animals; and many of them live in the water, and prefer that 

 which is mod corrupted and muddy. — The mouth of the culex, or 

 gnat confifls of a flexible fheath, inclofing four briftles, or pointed 

 ftings. The feelers of the female gnat are plain like a thread ; 

 ^ut thofe of the male are beautifully feathered. The worms or 



caterpillars 



