120 THE COLOUES OF ANIMALS 



off, and was placed in a dark box lined with black 

 paper, but it subsequently deepened into a green 



PIG. 28. The pupa of Peacock FIG. 29. The pupa of Peacock 



Butterfly ; dark form ; natural Butterfly ; light yellowish-green 



size. form. 



pupa exactly like the others. Obviously the sur- 

 roundings had exercised their influence before the 

 pupa was removed. 



Experiments upon the chrysalis of the Small Tortoise- 

 shell Butterfly 



Being unable to obtain more larvae of the Peacock, 

 I worked upon the allied Small Tortoiseshell Butterfly 

 (Vanessa urticce), which can be obtained in immense 

 numbers. In the experiments conducted in 1886, 

 over 700 chrysalides of this species were obtained and 

 their colours recorded. Green surroundings were 

 first employed in the hope that a green form of pupa, 

 unknown in the natural state, might be obtained. 

 The results were, however, highly irregular, and there 

 seemed to be no susceptibility to the colour. The pupas 

 were, however, somewhat darker than usual, and this 



