the colours of certain Lepidoptera. 



373 



Experiments 3 and 3 a. 



Another small batch, also found July 30, continued 

 feeding for a day or two, and were then subjected to 

 similar conditions. They were in fact probably placed 

 in the same receptacles with the same conditions of 

 illumination, but 1 have no note upon the latter point. 



These brief notes show the same prolongation of the 

 preparatory period in dark surroundings even more 

 clearly than in Experiment 2 and 2 a. We may conclude 

 that dark surroundings in light produce the same effect 

 in this respect as darkness. 



Other conclusions as to the effect upon pupal colours 

 of different metallic surfaces, and of darkness as op- 

 posed to black surroundings in light, are to be gained 

 from Experiment 1 ; but they are better deferred until 

 after the examination of the experiments made in 1888. 



1888. 



The object of the numerous experiments made during 

 this year was to obtain abundant confirmation of the in- 

 fluence of surroundings upon the pupal colours, and also 

 to test the effect of various metallic surfaces, &c. It will 

 be most convenient first to tabulate the whole of the 

 experiments, briefly indicating the results of each, and 

 then to analyse the tables in such a manner as to show 

 the chief conclusions. 



