STATES OF INSECTS. 281 



a double purpose ; being necessary to compress the ab- 

 domen of the moth as it emerges from the cocoon, which 

 forces the fluids to enter the nervures of the wings, and 

 give them their proper expansion. For he found, that 

 when the pupa is taken out of the cocoon, the moth is 

 disclosed at the proper time, but remains always crippled 

 in its Avings ; which never expand properly, unless the 

 abdomen be compressed with the finger and thumb, so 

 as to imitate the natural operation a . 



I am next to give you some account of the second 

 mode in which the release of the perfect insect from 

 its cocoon is effected — that, namely, wherein its own 

 exertions chiefly accomplish the work. I shall from a 

 large number select only a few instances. The texture 

 of the cocoon of the silkworm-moth is uniform in every 

 part, and the layers of silk are equally thick at both 

 ends. The moth makes its way out by cutting or 

 breaking these threads at the end opposite to its head : 

 an operation which, as it destroys the continuity of 

 the silk, those who breed these insects are particularly 

 careful to guard against, by exposing the cocoon to 

 heat sufficient to destroy the included pupa. The ques- 

 tion is — What instruments does the moth employ to 

 effect this? And this we are not able to answer satis- 

 factorily. Malpighi asserts that the animal first wets the 

 silk with a liquid calculated to dissolve the gum that 

 connects the threads, and then employs its lengthened 

 head to push them aside and make an opening 5 . But, as 

 Reaumur has observed, besides that so obtuse a part as the 

 head of a moth is but ill fitted to act as a wedge, we find 



a Naturf. viii. 133. b Be Bombgc. 29. 



