316 INSECT ARCHITECTURE. 



purposely left this part less strongly cemented, and 

 less exactly closed. She is instinctively conscious 

 that this is to be the passage for the perfect insect 

 which she carrries in her bowels, and has therefore 

 the additional precaution never to place this pointed 

 extremity against any substance that might obstruct 

 the moth at the period of its egress. 



" When the caterpillar has exhausted herself to 

 furnish the labour and materials of the three cover- 

 ings, she loses the form of a worm, her spoils drop 

 all around the chrysalis; first throwing off her 

 skin, with the head and jaws attached to it, and the 

 new skin hardening into a sort of leathery consist- 

 ence. Its nourishment is already in its stomach, and 

 consists of a yellowish mucus, but gradually the rudi- 

 ments of the moth unfold themselves, — the wings, 

 the antennae, and the legs becoming solid. In about 

 a fortnight or three weeks, a slight swelling in the 

 chrysalis may be remarked, which at length produces 

 a rupture in the membrane that covers it, and by 

 repeated efforts the moth bursts through the leathery 

 envelope into the chamber of the cocoon. 



"• The moth then extends her antennae, together 

 with her head and feet, towards the point of the cone, 

 which not being thickly closed up in that part gra- 

 dually yields to her efforts; she enlarges the opening, 

 and at last comes forth, leaving at the bottom of the 

 cone the ruins of its former state — namely, the head 

 and entire skin of the caterpillar, which bear some 

 resemblance to a heap of foul linen."* 



Reaumur was of opinion that the moth makes use 

 of its eyes as a file, in order to effect its passage 

 through the silk; while Malpighi, Peck, and others, 

 believe that it is assisted by an acid which it dis- 

 charges in order to dissolve the gum that holds the 



* Spectacle de la Nature, vol. i. 



