The Larva and the Nymph 



In four-and-twenty hours the nymph will 

 burst its fetters. 



It takes the nymph only six or seven days 

 to don its final tints, omitting the eyes, whose 

 colouring precedes that of the rest of the 

 body by fourteen or fifteen days. The law 

 governing the insect's chromatic evolution is 

 easily gathered from this brief sketch. We 

 see that, with the exception of the eyes and the 

 ocelli, whose early development recalls what 

 takes place in the higher animals, the start- 

 ing-point of the coloration is a central spot, 

 the mesothorax, whence it gradually invades, 

 by centrifugal progression, first the rest of 

 the thorax, then the head and abdomen, lastly 

 the different appendages, the legs and an- 

 tennae. The tarsi and the mouth-parts col- 

 our later still; and the wings do not assume 

 their hue until after they are taken from 

 their cases. 



We now have the Sphex arrayed in her 

 livery. She has yet to cast her nymphal 

 wrapper. This is a very fine tunic, moulded 

 exactly in accordance with the smallest struc- 

 tural details and scarcely veiling the shape 

 and colours of the perfect insect. As a pre- 

 lude to the last act of the metamorphosis, the 

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