114 THE COLOURS OF ANIMALS 



had had thousands of pupae of Papilio machaon, and 

 had often had the brown variety of pupa on a green 

 ground colour, whilst in some seasons he had obtained 

 no brown specimens at all.' 



In spite of this unfortunate mistake, Mr. Wood 

 adduced quite sufficient evidence concerning the 

 Garden Whites to show that the subject was worth 

 investigation. But the great example and the great 

 principles of Darwin had not penetrated far into the 

 mass of naturalists ; and distinguished entomologists 

 preferred the expression of an adverse opinion, to 

 making an easy experiment upon one of our commonest 

 insects. 



Mr. Wood also stated that the chrysalis of the 

 Large Tortoiseshell Butterfly (Vanessa polychloros) was 

 coloured like a withered elm-leaf, when suspended 

 among the foliage of the elm on which its caterpillar 

 feeds. Its colour was then light reddish-brown with a 

 cluster of metallic silvery spots, but when suspended 

 from a wall, the metallic spots were not produced, 

 and the pupa was of a mottled greyish colour. This 

 observation led Mr. Wood to conclude ' that by the 

 proper use of gilded surfaces the gilded chrysalides of 

 Vanessa, and perhaps of other genera, would be ob- 

 tained ' ; and he added, ' I hope to be able to try the 

 experiment next season.' If this intention had been 

 carried out, such startling results would have been 

 obtained that opposition would have broken down 

 before them, and the combined researches of many 



