118 THE BUTTERFLY VIVARIUM. 



the larva of which forms a very compact earthy 

 cocoon, waits till its wings are hecome hard 

 before it can effect its escape, which it does by con- 

 stantly rubbing them against his earthen sarco- 

 phagus, and is sometimes fourteen or fifteen days 

 in effecting his escape. The May-bug is said to be 

 a whole month making his way out of his own 

 house ; and, according to Roesel, the Stag Beetle is 

 about three weeks. 



The larva of a small Tinea pierces a grain of 

 wheat with a very minute puncture, and after 

 making its way in by this modest little door, very 

 soon becomes too fat on the rich farinaceous food 

 to think of getting out the same way. Before 

 entering into the pupa state, however, it takes the 

 precaution to eat away a small circular portion so 

 close to the last external cuticle, that when the 

 perfect insect emerges from the chrysalis, it easily 

 forces its way out. Bonnet, who was the first, I 

 believe, to describe this process, mentions similar 

 means adopted by other small Moths on escaping 

 from their chrysalides, when similarly situated. 



The escape from the cocoon is also effected in 

 other ways. In some instances the larva forms a 

 lid to the cocoon, by means of which the perfect 

 insect easily makes its way out, as is the case with 



