The Larva a7id the Nymph 99 



withered slough ; the nymph, that transitory 

 organism, or rather that perfect insect in 

 swaddHng-bands, motionlessly awaits the awak- 

 ening which will not take place for another 

 month to come. The legs, the antennae, the 

 exposed mouth-parts and the wing-stumps have 

 the appearance of clearest crystal and lie evenly 

 spread under the thorax and the abdomen. 

 The rest of the body is an opaque white, very 

 faintly smeared with yellow. The middle four 

 segments of the abdomen carry a narrow and 

 blunt extension on either side. The last seg- 

 ment, terminating above in a blade-like ex- 

 pansion shaped like the sector of a circle, is 

 equipped below with two conical protuberances 

 set side by side : this makes in all eleven 

 appendages studding the outline of the abdomen. 

 Such is the delicate creature which, to become 

 a Sphex, must don a motley livery of black and 

 red and throw off the fine skin in which it is 

 closely swathed. 



I was curious to follow from day to day 

 the appearance and the progress of the nymph's 

 colouring and to test whether the light of the 

 sun, that rich palette whence nature derives her 

 colours, could influence that progress. With 

 this object, I took pupae from their cocoons and 

 put them in glass tubes, of which some, kept 

 in complete darkness, realized the natural con- 



