63 



so quick, that in a quarter of an hour's 

 time they are arrived to their full size, 

 which requires indeed attention. After 

 they have acquired their proper firmness, 

 which is done in another quarter of an 

 hour, the pupa cleanses itself by dis- 

 charging a tew drops of a blood-coloured 

 liquid ; then the pupa expands his 

 winffs and folds them aa:a'n\ toojether 

 which causes a little noise ; after this he 

 flies away with alacrity as if it had been 

 in the practice of it for a long time, 

 hence it becomes one of those beautiful 

 harbingers of spring, a butterfly. 



We have now before us, instead of an 

 odious worm, a flying creature ; instead 

 of a creeping one, an insect which flutters 

 at its ease, inhaling sweets from every 

 flower, instead of a caterpillar which chose 

 the apple-tree for its food and abode. 

 We must examine it closer : I will de- 

 scribe, first the wings, especially the 

 underside of them, as this shews itself 

 first. They are grey, painted like mar- 

 ble with many transverse pointed lines. 

 Each wing is in the same manner beau- 



