372 Mr. F. Merrifiekl ami Mr. E. B. Poulton on 



A portion of my investigations were carriei on jointly 

 with Miss Cora B. Sanders, of Lady Margaret Hall, 

 Oxford. These Sections are preceded by her name or 

 initials as well as my own. 



The e.xperiments upon the colours of the pupae of Vanessa 

 io were carried on, under my direction, by Miss Mabel E. 

 Notley and Miss Florence A. Wright, of Lady Margaret 

 Hall. Their names are added to the title of the Section in 

 which the experiments are described. 



Some interesting observations of Mr. A. H. Hanini and 

 Mr. W. Holland of the Hope Department of Zijology, 

 Oxford, form in large part or entirely the subjects of two 

 Sections to which their names have been added. 



Sir John Conroy, F.R.S., very kindly helped me in 

 determining the quality of the light reflected from the 

 various backgrounds, and his name has been similarly 

 added to the Appendix in which our results are described. 



I wish also warmly to thank Mr. W. Holland and Mr. A. 

 H. Hamm of the Hope Department for their most efficient 

 help in many parts of the work ; Mr. C. V. A. Peel for 

 kindly lending .specimens which have been described, and 

 Mr. Arthur Sidgwick and Mr. Nicholson for drawing my 

 attention to interesting observations made by them which 

 are recorded in Section I. 



E. B. Poulton. 



^.—EXPERIMENTS UPON THE PUPiE OF 



Fapilio machaon. 



1. Experiments upon the Summer Pup.e of 

 Fapilio machaon. (F. M.) 



I am generally away from home from nine or ten o'clock 

 until five or later, and therefore my opportunities for 

 takinof a larva iust at the right moment, when it has 

 done feeding and before its sensitiveness to colour has 

 begun, are imperfect. But I was able to select fourteen 

 larvaB, which seemed to have arrived at the full-fed stage, 

 and I prepared a few glass cylinders of about 6 inches in 

 height and mostly 3| inches in diameter, though some 

 were an inch or two wider, which 1 placed in flower-pots 

 nearly filled with earth. They were in two divisions, viz. 

 (1) furnished with dark sticks, and (2) furnished with light 

 sticks. Division (1) had about six dark brown sticks of 

 from \ to I of an inch in diameter taken from an old 



