2o5 



Microscopical Essays. 



and fmall, extend themfelves, are ftrengthened and hardened in- 

 fenfibly, and the fibres which were at firft flexible become hard 

 and ftiff ; even fo ftiff, that Malphigi confidered them as bones : 

 in proportion as thefe fibres harden, the fluid which circulates 

 within them, and extends the wings, lofes it's force ; fo that if 

 any extraneous circumftance prevents the motion of this fluid, at 

 the firft inftant of the moth's efcape from it's former ftate, 

 the wing will then become ill-fhaped; often expanding with 

 fu ch rapidity, that the naked eye cannot trace it's unfold "ng. 

 The wing, which was fcarce half the length of the body, acquires 

 in a few minutes it's full fize, fo as to be nearly five times as large 

 as they were before : nor is it the wings only , which are thus in- 

 creafed ; all their fpots and colours, heretofore fo minute as to be 

 fcarce difcernible, are proportionally extended, fo that what be- 

 fore appeared as only fo many unmeaning and confufed points, 

 become diftincl; and beautiful ornaments ; and thofe that are 

 furnifhed with a tongue, or trunk, curl and coil it up. 



When the wings are unfolded, the tongue rolled up, the 

 moth fufficiently dried, and the different members ftrengthened, 

 it takes it's flight. Moft of them, foon after they have attained 

 their perfect ftate, void an excrementitious lubftance, which 

 M. de Reaumur thinks is the laft time of their doing it ; that they 

 reject very little, if any, during the reft of their lives. 



If the moth is opened down the belly, and the fatty parts 

 which fill it are removed, the grofs artery, which has been called 

 the heart, will be vifible, and the contractions and dilations, by 

 which it pufhes forwards the liquor it contains, may be eafily ob- 

 ferved. One of the moft remarkable circumftances is, that the 

 6 circula- 



