244 STATES OF INSECTS. 



which they may be discerned, and separated with the 

 point of a pin a . In proportion as these acquire consist- 

 ency, and are more and more developed by the absorp- 

 tion of the surrounding fluid, they occupy its place, and 

 fill up the cavity of the puparium. The rest of this fluid 

 passes off by transpiration b . Reaumur is of opinion that 

 it is from the epiploon, or corps graisseux, that this matter 

 is prepared, which he regards as analogous to the white 

 of an egg c . In coarctate pupae the included animal, or 

 the pulp that contains its germes (in which the limbs and 

 body at first are not discernible), fills at this period the 

 whole skin-cocoon ; but in proportion as the above eva- 

 poration takes place, and the consolidation of the body 

 and parts proceeds, it shrinks at each end, so that when 

 near assuming the imago, a considerable cavity appears 

 both at the head and tail of the cocoon d . At this period 

 of its existence, from the quantity of fluid included in the 

 puparium, the animal weighs usually considerably more 

 than it does when become a perfect insect e . 



The exterior integument or skin of pupae, which is usu- 

 ally lined with a very thin white pellicle, is of different 

 consistence in different orders. In the Coleoptera and 

 Hymenoptera it is, with a few exceptions, of a soft and 

 membranous texture; in the Lepidoptera (especially those 

 that are not defended by cocoons), and Diptera, it is more 

 rigid and harder, being either coriaceous or corneous. 

 Lepidopterous pupae, however, are not excluded from 



a N. Diet. a" Hist. Nat. vii. 57. b De Geer ii. 105. 

 e Reaum. ii. 428 — . 



d Swamm. Bibl. Nat. Engl. Tr. ii. 32. t. xli./. 2. Comp. Reaum. 

 iv. t. xxv. f. 1. 

 * Ibid.L 144, 



