OF NATURAL HISTORY. 273 



with a kind of cruft or fhell, from which the animals have 

 ^gain to efcape, as from a fecond egg. In this imprifoned 

 condition, they remain during a longer or fhorter period, 

 according to the fpecies, or to the feafon of the year in 

 which they are transformed. After their transformation in- 

 to flies, they burft this crufl or fhell, and appear in the form 

 of flies, furniftied with wings, legs, feelers, &c. of all which 

 they were deftitute in their former ftate. When transform- 

 ed into flies, caterpillars have arrived at the age of puberty. 

 They are now perfe<St animals, and endowed with the faculty 

 of tranfmitting a numerous progeny to pofterity. 



