64 POPULAR ENTOMOLOGY. 



furnished witli the means of liberation, which is then 

 effected by an acid secretion discharged on the part from 

 which it desires to make its exit, and which then yields to 

 the slightest pressure. 



When the caterpillar provides the means of escape for the 

 future Moth, it does so, generally, by making a circular inci- 

 sion near one end, leaving a small piece as a hinge ; but in 

 some cases a more elaborate contrivance is resorted to, such 

 as that of the Emperor Moth, which makes at one end of 

 the cocoon a funnel-shaped opening, hke the neck of a 

 flask, composed of a series of loose threads, converging 

 like bristles to a blunt point, and formed of strong silk, 

 well gummed. To prevent any enemy attacking the helpless 

 inmate through this opening, the larva forms another funnel 

 within, in which there is no opening, but through which, 

 being made of very elastic threads, the moth can easily 

 effect its egress. These elastic threads also answer another 

 purpose, that of compressing the body of the Moth as it 

 emerges, thus forcing a fluid into the nervures of the wings, 

 and giving them their proper expansion ; for if the pupa is 

 tahen out of the cocoon, the wings remain crippled"^. 



We have now traced the Lepidojitera through the three 



* Kirby and Spence, ' Introduction to Entomology.' 



