Microscopical Essays. tgj 



the body like a wedge into this flit, by which means it is foon 

 opened from the firfl down to the fourth ring ; this renders it large 

 enough for the infect to pafs through, which it foon effects in a 

 very curious manner. The caterpillar generally fails a whole 

 day after each moulting,, for it is neceffary that the parts fhould 

 acquire a certain degree of confiftency, before it can live and act 

 in it's ufual manner ; many alfo perifh under the operation. 



The infect always appears much larger after it has quitted the 

 exuvia ; the body had grown under the old fkin, till it was be- 

 come too large for it : now as the growth was gradual, and the 

 parts foft, the fkin prefied them together, fo that they lay in a 

 fmall fpace ; but as foon as the fkin is call off, they are as it 

 were liberated from their bonds, and diftend themfelves con- 

 iiderably. Some caterpillars, in changing their fkin, from fmooth 

 become covered with fine hair ; while others, that were covered 

 with this fine hair, have the lafl fkin fmooth.* 



Of the Pupa. 



Before we defcribe the change of the larva into the pupa flate^ 

 it will be neceffary to give the reader an account of thofe names 

 by which naturalifts- diftinguifh the different appearances of infects 

 in the pupa Rate. 



It is called coarctata, when it is flraitened or confined tq» 

 a cafe of a globular form, which has no refemblance to the infect 

 it contains. 



It 



* Valmont de Bomare Di&Ionnaire Univerfel d'Hiftoire Naturelle, vol., in 

 2d edit. 121110. p. 394. 



