TIME OCCUPIED. 223 



once in its life, should execute them so well; and 

 we are led to the inevitable conclusion that it 

 has been thus taught by a Great and All-wise 

 Master." 



The manner in which other larvae cast their 

 skins and become pupae when they enter their cell 

 cannot be described, as they perform this act in 

 all the privacy and darkness of their solitary 

 habitations ; but in all probability it differs in no 

 respect from the manner in which the same crea- 

 tures cast their skins when they moult, excepting 

 that the new being which emerges from the cast- 

 skin is no longer a larva, but a pupa. 



The time occupied by the creature in its process 

 of change differs in different species. In some it 

 is short, in others it is long. Generally, it does 

 not exceed a few days. We are told, however, of 

 the larva of some insects which are six months 

 before they become pupae. The Baron de Geer 

 tells us with surprise of the larva of a moth 

 which he had watched. It became a larva, and 

 spun its cocoon, in the month of August, 1746, 

 and was attentively kept during the winter. The 

 spring came, but the larva still remained a larva, 

 and did not show any signs of changing its form ; 



