VARIABLE PROTECTIVE EESEMBLANCE IN INSECTS 111 



no experimental researches have been conducted. I 

 will first consider the chrysalides, because they were 

 first found to possess the power, and because it has 

 been more completely investigated in them than in 

 the other cases. . 



Variable Protective EesemDiance in Lepidopterous Pupae. 



The capability of adjusting the colour to that 

 of the surroundings is only present in exposed chry- 

 salides, and has not been found hitherto among 

 the pupae of Heterocera (or moths), nearly all of 

 which are either buried in the earth or concealed in 

 opaque cocoons. In both cases the chrysalides are 

 generally reddish-brown in colour, the shade varying 

 greatly in different species. The dark colour is of pro- 



FlG. 23.— The pupa of Swallow- 

 tailed Moth, showing colour 

 assumed when the larva has 

 been placed on white paper 

 before pupation. 



Fig. 24.— The pupa of Swallow- 

 tailed Moth {Uropteryx sambu- 

 cata) ; the usual dark colour 

 assumed in cocoon ; natural 

 size. 



tective value when the chrysalis is accidentally ex- 

 posed upon the surface of the earth. 



Since this last paragraph was written, I have 

 found that the chrysaHs of the Swallow-tailed Moth 



