LEPIDOPTEKA. 169 



thick ; as they grow, little by little they spread themselves out 

 and become curled up. When they are completely developed and 

 flattened, the wings become firm and hard imperceptibly, and this 

 firmness extends at the same time to the whole of the body. 



Figs. 131 and 132, borrowed, like the preceding, from the 14th 

 memoir of Reaumur (sur la transformation des chysalides en 



Fig. 131. Moth whose wings are developing. Fig. 132. Moth whose wings are developed. 



papillons), show the states through which the wings of the same 

 moth pass, before they are thoroughly developed. 



Those pupae enclosed in cocoons free themselves entirely or 

 in part from their old skin, in the shell itself; but the imago 

 is still a prisoner. It has broken through a first enclosure; it 

 must open itself a way through the second. How does it manage 

 to bore through the often very solid walls of this second prison, 

 so as to regain its liberty ? Reaumur stated that in the Lackey 

 moth (Bombyx neustria) the head is the only instrument of which 

 the insect makes use in opening a passage, the compound 

 eyes then acting like files. These files cut the very fine threads 

 of which the cocoon is composed, and as soon as the end of the 

 cocoon is pierced through, the insect uses its thorax like a wedge, 

 to enlarge the hole. It very soon manages to get its two front 

 legs out, fixes itself by them onto the outside, and little by little 

 emerges from its prison. 



THE PERFECT INSECT. 



Who does not admire the extraordinary splendour, the vivacity, 

 the prodigious variety of colours of these brilliant inhabitants of 



