90 THE PHILOSOPHY 



fume after their transformation into flies. The caterpillars of the 

 gartlen-beetle, cock-chafer, &c. lead a folitary life under ground, 

 and confume the roots of plants. Thofe of others feed upon putrid 

 carcafTes, every kind of flefh, dried fkins, rotten wood, the dung of 

 men and quadrupeds, and the fmall infe<5ts called pucerons, or -uiiie- 

 fretters. The devourers of the puceron contribute to cure fuch 

 plants as happen to be infedted ^?»ith the phihinajis, or loufy difeafe. 

 But, after their transformation into flies, many of the fame animals, 

 which formerly fed upon dung and putrid carcaffes, are noutiflied 

 by the pureft nedareous juices extraded from fruits and flowers. 

 The creatures themfelves, with regard to what may be termed indi- 

 'vidiial animation, have fuffered no alteration. But the fabrick of 

 their bodies, their inftruments of motion, and the organs by which 

 they take their food, are materially changed. This change of ftruc- 

 ture, though the animals retain their identity, produces the greateft 

 diverfity in their manners, their oeconomy, and the powers of their 

 bodies. In the caterpillar ftate, thefe animals are extremely vora- 

 cious, and, in many inftances, acquire a greater magnitude than they 

 pofl^efs after transformation ; but they are incapable of multiplying 

 their fpecies, and of receiving nourifhment from the fame kinds of 

 food. Befides, many caterpillars, previous to their transformation, 

 live even in a different element. The ephemeron fly, when in the 

 caterpillar ftate, lives no lefs than three years in the water, and ex- 

 tradts its nourifhment from earth and clay. After transformation, 

 this animal feldom exifts longer than one day, during which the 

 fpecies is propagated, and myriads of eggs are depofited on the fur- 

 face of the water, Thefe eggs produce worms or caterpillars, and 

 the fame procefs goes perpetually round. 



Linnaeus's fecond order of infeds, or hemiptera, have likewife 

 four wings. But the upper pair, inftead of being hard and horny, 

 rather refemble fine vellum. They cover the body horizontally, 



3 and 



