OF N ATUR AL HISTO R Y. a^j 



ed from a difgufting, hairy caterpillar, provided with jaws and teeth, 

 and fourteen feet ? Without experience, who could imagine that a 

 long, white, fmooth, fofi worm, hid under the earth, fhould be tranf- 

 formed into a black, cruftaceous beetle, having wings covered with 

 horny elytra, or cafes? 



Upon this branch of the fubjeit, we (hall, fajl, give an example 

 or two of the moft common transformations of Infe£ts; zx\di,fccond~ 

 ly, defcribe fome of the more uncommon kinds. 



Befide their final metamorphofis into flies, caterpillars undergo 

 feveral intermediate changes. All caterpillar* caft or change their 

 (kins oftener or more feldom, according to the fpecies. Malpighius 

 informs us, that the filk-worm, previous to its chryfalis ftate, cafts 

 its fkin four times. The firft fkin is caft on the loth, i ith, or 12th 

 day, according to the nature of the feafon ; the fecond in five or fix 

 days after ; the third in five or fix days more ; and the fourth and 

 laft in fix or feven days after the third. This changing of fkin is 

 not only common to all caterpillars, but to every infedl whatever. 

 Not one of them arrives at perfedion without cafting its fkin at leaft 

 once or twice. The (kin, after it is caft, preferves fo entirely the 

 figure of the caterpillar in its head, teeth, legs, colour, hair, &c. that 

 it is often miftaken for the animal itfelf. A day or two before this 

 change happens, caterpillars take no food : They lofe their former 

 adlivity, attach themfelves to a particular place, and bend their bo- 

 dies in various diredions, till at laft they efcape from the old fkin, 

 and leave it behind them. The Inteftinal canal of caterpillars is 

 compofed of two principal tubes, the one inferted into the other. 

 The external tube is compad and flefhy ; but the Internal one is 

 thin and tranfparent. Some days before caterpillars change Into the 

 chryfalis ftate, they void, along with their excrement, the inner tube 

 which lined their ftomach and inteftines. When about to pafs Into 

 I O o 2 the 



