INFANCY OF CRABS AND CATERPILLARS 253 



examined, shows the form of the gorgeous wings that are 

 to be, the long, honey-sucking proboscis that is to replace 

 the horny jaws, the long legs folded neatly together, and 

 the rings of the body. 



Many of these caterpillars, for their greater security, 

 take the precaution to fasten a silken cord around their 

 bodies to hold them in safety during their long sleep 

 through the storms of winter — a precaution which seems 

 to display a quite uncanny foreknowledge. But the 

 custom which obtains among some of the moth tribe at 

 this time is still more singular, for while most simply 

 bury themselves and become transformed into " pupae," 

 as the chrysalises of the moths are called, among a large 

 number of species the caterpillar, as if realising that the 

 end of its life is near, proceeds to weave for itself a silken 

 shroud, or " cocoon," within which the form of the pupa 

 is assumed. The silk is formed in a fluid state by glands 

 within the mouth, and is drawn thence as a sticky thread, 

 which hardens at once on exposure to the air. How it 

 contrives to weave this wondrous winding-sheet is a 

 matter which passes one's comprehension. 



These silken fabrics, as a rule, enclose the body as a 

 nutshell encloses the kernel ; and as the moth which is 

 to emerge has no jaws, special means have had to be 

 devised to save the resurrected body from the horrors 

 of a living grave. The puss-moth escapes by soaking 

 one end of the cocoon with a corrosive fluid containing 

 potassium hydroxide, and protects itself from injury 

 therefrom, while passing through the moistened gateway 

 to life, by a shield formed of a portion of the pupa skin. 

 Some cut their way out by means of a spine at the base 

 of the front wing. Yet more remarkable is the case of 

 the emperor moth, which, in spinning its cocoon, fashions 



