v] TRANSFORMATIONS 37 



it left the egg. From the tiny, newly-hatched larva 

 to the full-fed caterpillar, possibly several inches in 

 length, there is all along the same crawling, some- 

 what worm-like body, destitute of any outward trace 

 of wings. When however the last larval cuticle has 

 split open lengthwise along the back, and has been 

 worked oif by vigorous wriggling motions of the 

 insect, the pupa thus revealed shows the wing- 

 rudiments conspicuous at the sides of the body, and 

 lying neatly alongside these are to be seen the forms 

 of feelers, legs, and maxillae of the imago prefigured 

 in the cuticle of the pupa (fig. 1 e). The pupa thus 

 resembles the imago much more closely than it 

 resembles the larva ; even in the proportions of the 

 body a relative shortening is to be noticed, and the 

 imago of any insect with complete transformation is 

 reduced in length as compared with the full-fed 

 larva. Now these wings and other structures charac- 

 teristic of the imago, appear in the pupa which is 

 revealed by the shedding of the last larval cuticle. 

 From these facts we infer that the wing-rudiments 

 must be present in the larva, hidden beneath the 

 cuticle ; and until the last larval instar, not beneath 

 the cuticle only, but growing in such-wise that they 

 are hidden by the epidermis. For if they were 

 growing outwardly the new cuticle would be formed 

 over them, so that they would be apparent after the 

 next moult. But it is clear that only in the pupa, 



