(2a 7 iy 
X. Experiments upon the colour-relation between the 
pupe of Pieris rape and their immediate sur- 
roundings, by Grorce C. Grirriras, F.E.S. ; 
described and summarised by Witi1aM WHITE, 
F.E.S. 
[Read March 7th, 1888. | 
CONTENTS. 
1. Introduction. 
2. The methods of experimentation. 
3. The nature of the colours employed. 
4. Mr. Poulton’s standard of the degrees of colour in the pupe of 
P. rape. 
5. Experiments with various colours. 
I. Black. 
II. White. 
III. Pink. 
IV. Yellow. 
V. Green. 
VI. Blue. 
_ 6. Miscellaneous experiments. 
7. Conclusions. 
1. Inrropuction.—The experiments described in the 
following paper grew out of a series of observations upon 
Pieris rape, which had been carried on by my friend 
Mr. George C. Griffiths, at Cotham (Bristol), with the 
view of determining the constancy or variability of the 
yellow variety of this common species of butterfly pro- 
duced from mignonette-fed larve. Another question, 
that of the colour-variation of the pup, had meanwhile 
been systematically attacked by Mr. Kdward B. Poulton, 
who, after submitting a very large number of specimens 
of this and other lepidopterous genera to strong colour- 
tests, had drawn up and thoroughly discussed the results 
obtained in a paper read before the Royal Society in 
February of last year, and which has since been issued, 
with an admirable coloured plate, in the ‘ Philosophical 
Transactions’ (vol. 178, 1887, B., pp. 811—441). 
TRANS. ENT. SOC. LOND. 1888.—PART Ir. (JUNE.) 
