CHAPTER IX 



VARIABLE PROTECTIVE RESEMBLANCE IN 

 INSECTS (continued) 



The meaning of the metallic appearance of pupae 



APART from the general physiological significance of 

 the results described in the last chapter, they are of 

 extreme interest in giving us a possible clue to the 

 meaning of the remarkable metallic appearance of 

 the pupae of many butterflies. This wonderful appear- 

 ance has given the name chrysalis to the second 

 stage of Lepidopterous metamorphosis, although rela- 

 tively few pupae are really entitled to bear it. But 

 some pupae which deserve the name are very common, 

 and probably have attracted attention ever since men 

 began to look with interest on the world around them. 

 Not only did the alchemists believe that in the appear- 

 ance of these animals they received encouragement 

 for the successful issue of the projects which were 

 always before them, but we find that Aristotle, writing 

 more than 2,200 years ago, mentions chrysalis as a 

 word which was generally used * in his time, and which 

 had therefore been invented as descriptive of the 



