VARIABLE PROTECTIVE RESEMBLANCE IN INSECTS 117 



both colours, that of the brick upon its back and that 

 of the wood upon its under surface. My experiments 

 upon the chrysalis of the Small Tortoiseshell Butterfly, 

 to be described below, do not support this conclusion, 

 and it is a common thing for the colours of pupae to 

 differ greatly in the dorsal and ventral regions. Mrs. 

 Barber also tried the effect of scarlet cloth, but little 

 if any influence was exerted. 



Mr. Mansel Weale also showed that the colour of 

 certain other South African pupae can be modified, 1 

 and Mr. Roland Trimen made some experiments 

 upon another African Swallow-tail 2 (Papilio demoleus, 

 common at Cape Town), confirmatory of Mrs. Barber's 

 observations. He covered the sides of the cage with 

 bands of many colours, and found that green, yellow, 

 and reddish-brown tints were resembled by the pupae, 

 while black made them rather darker. Bright red 

 and blue had no effect. The larvae did not exercise 

 any choice, but fixed themselves indiscriminately to 

 colours which their pupae could resemble and those 

 which they could not. In the natural condition the 

 latter would not exist, for the pupae can imitate all 

 the colours of their normal environments. 



Finally, Fritz Miiller experimented upon a South 

 American Swallow-tail (Papilio poly damns)? and found 



Trans. Ent. Soc. Land. 1877, pp. 271, 275. 

 2 Described in a letter to me, published in my paper already 

 referred to, p. 316. 



* Eosmos, vol. 12, p. 448. 



