198 STATES OJF INSECTS. 



ferent kinds of insects; the one the grab of a beetle, and 

 the other the caterpillars of Lepidoptera. The account of 

 the former is given quite in detail, as that of a person who 

 is describing what he has actually seen ■: yet by a later and 

 very able physiologist, Dr. Herold, it is affirmed that the 

 inner skin of the intestinal canal is never cast, that canal 

 constantly retaining its two skins. He further affirms, that 

 they are only the large trunks of the Tracheae that cast 

 their skins, none being detached from their smaller rami- 

 fications a . When men so eminent for their anatomical 

 skill and nicety, and for their depth and acumen, dis- 

 agree, the question must be regarded as undecided till 

 further observations throw sufficient weight into one scale 

 or the other. 



The larva which has undergone this painful process is 

 at first extremely weak: all its parts are soft and tender; 

 even the corneous ones, as the head and the legs, are then 

 scarcely more than membranous, and are all bathed with 

 a fluid, which, before the moult, intervenes between the 

 two skins, and facilitates their separation b : and it is 

 only after some hours, or in some cases even days, du- 

 ring which it lies without motion, that this humidity eva- 

 porates, all its parts become consolidated, and it reco- 

 vers its strength sufficiently to betake itself to its wonted 

 food. Its colour, too, is usually at first much paler than 

 before, and its markings indistinct, until their tints have 



a Entwickelungsgeschichte, &c. 34, 88. Swammerdam on the con- 

 trary affirms, that " on the hinder part of the cast skin where it is 

 twisted and complicated, whoever accurately examines the skin it- 

 self may still observe the coat that was cast by the intestmum rectum, 

 Ubisupr. 136. col. a. 



b N. Did. d'ffist. Nat. vi. 290. 



