THE CATERPILLAR KIND. 169 



capable of spinning themselves a web, set about this operation •, 

 those which have already spun, await the change in the best 

 manner they are able. The web or cone with which some cover 

 themselves, hides the aurelia contained within from the view ; 

 but in others, where it is more transparent, the caterpillar, when 

 it has done spinning, strikes into it the claws of the two feet 

 under the tail, and afterwards forces in the tail itself, by con- 

 tracting those claws, and violently striking the feet one against 

 the other. If, however, they be taken from their web at this 

 time, they appear in a state of great languor, and, incapable of 

 walking, remain on that spot where they are placed. In this 

 condition they remain one or two days, preparing to change 

 into an aurelia, somewhat in the manner they made prepara- 

 tions for changing their skin, They then appear with their 

 bodies bent into a bow, which they now and then are seen to 

 straighten ; they make no use of their legs, but if they attempt to 

 change place, do it by the contortions of their body. In pro- 

 portion as their change into an aurelia approaches, their bodies 

 become more and more bent, while their extensions and convul- 

 sive contractions become more frequent. The hinder end of 

 the body is the part which the animal first disengages from its 

 caterpillar skin ; that part of the skin remains empty, while the 

 body is drawn up contractedly towards the head. In the same 

 manner they disengage themselves from the two succeeding 

 rings, so that the animal is then lodged entirely in the fore part 

 of its caterpillar covering ; that half which is abandoned re- 

 mains lax and empty, while the fore part, on the contrary, is 

 swoln and distended. The animal having thus quitted the 

 hinder part of its skin to drive itself up into the fore part, still 

 continues to heave and work as before ; so that the skull is soon 

 6een to burst into three pieces, and a longitudinal opening is 

 made in the three first rings of the body, through which the in- 

 sect thrusts forth its naked body, with strong efforts. Thus at 

 last it entirely gets free from its caterpillar skin, and for ever 

 forsakes its most odious reptile form. 



The caterpillar, thus stripped of its skin for the last time, is 

 now become an aurelia ; in which the parts of the future butter- 

 fly are all visible, but in so soft a state, that the smallest touch 

 can discompose them. The animal is now become helpless and 

 motionless : but only waits for the assistance of the air to dry 

 up the moisture on its surface, and supply it with a crust capa- 

 ble of resisting external injuries. Immediately after being strip- 

 ped of its caterpillar skin, it is of a green colour, especially in 

 those parts which are distended by an extraordinary afflux of 

 animal moisture ; but in ten or twelve hours after being thus 

 exposed, its parts harden, the air forms its external covering 

 17 P 



