Experiments upon the colour-relation, dc. 267 
interesting experiments, it is of high importance that 
the confirmation of recently-published results obtained 
by larger experiments and more accurate methods should 
be afforded by the work of an entirely independent 
investigator. Mr. Griffiths was, in fact, entirely 
unaware of Mr. Poulton’s conclusions, and imagined 
- that the former theory of ‘“‘ photographic susceptibity ” 
on the part of the freshly-formed pupa accounted for 
the facts. It is therefore interesting to note that, had 
not this latter theory been already entirely upset by 
Mr. Poulton’s investigations, it would have been equally 
disproved by the experiments recorded in the present 
paper. 
