OF NATURAL HISTORY. 99' 



fiies. The caterpillars of the garden-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 flefli, dried fkins, rotten wood, the dung of men and 

 quadrupeds, and the fmall infects called pticerons, or miiefrcU 

 iers. The devourers of the puceron contribute to cure fuch 

 plants as happen to be infefled with the phthirlaftS) or loufy 

 difeafe. But, after their transformation into flies, many of 

 the fame animals, v/hich formerly fed upon dung and putrid 

 tarcaffes, are nourilhed by the pureft ne^lareous juices ex- 

 trafled from fruits and flowers. The creatures themfelves, 

 with regard to what may be termed individual animation^ have 

 fulFered 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 diveriity in their manners, their oeconomy, and the 

 powers of their bodies. In the caterpillar ftate, thefe ani- 

 mals are extremely voracious, and, in many inftances, acquire 

 a greater magnitude than they poflefs after transformation ^ 

 but they are incapable of multiplying their fpecies, and of re- 

 ceiving nourifhment from the fame kinds of food. Belides, 

 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 extra£ls its nourifliment from earth and clay. After 

 transformation, this animal feldom exifls longer than one 

 day, during which the fpecies is propagated, and myriads of 

 eggs are depofited on the furface of the water. Thefe eggs 

 produce worms or caterpillars, and the fame procefs goes per- 

 petually round. 



Linnaeus'sy^<:c)«fi? order of infects, or hemiptera^ have like- 

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

 and horny, rather refenible fine vellumo Thev cover the 



