m COLOR-RELATIONS OF CHRYSALIDS 



from reaching the nervous centres through the 

 ocalli of the caterpillar. All his successful experi- 

 ments came when applied to that period of the 

 transformation to which we have referred. 



Most of the experiments were made upon three 

 species, the Small Tortoise-shell (Aglais urticae), 

 the Large Cabbage White (Mancipium brassicae), 

 and the Small Cabbage Wliite (Pieris rapae). 

 The experiments consisted in preparing for the 

 creatures during their changes artificial surround- 

 ings of different colors : green, orange, black, white, 

 and gilt. Over seven hundred chrysalids in all 

 were experimented upon, and it was found that 

 with Aglais urticae green and orange surroundings 

 caused no effect on the pupal colors, black produced 

 as a rule dark chrysalids, while white produced 

 light colored ones, many of the last being bril- 

 liantly golden ; this suggested the use of gilt sur- 

 roundings, which were far more efficient than 

 white in producing chrysalids of a distinctly golden 

 color, more so even than often occurs in a state 

 of nature. The influence of black was curiously 

 shown by the fact that when the caterpillars changed 

 to chrysalids upon light surfaces, those which under- 

 went their transformations in close proximity to one 

 another were darker than those which were more 



