Phylogeny of the Pierinee. 251 
story of the modifications of species’; they enable us to 
perceive changes that would otherwise be uncertain and 
difficult of observation, and exhibit to us on an enlarged 
scale the effects of the climatal and other physical con- 
ditions which influence more or less profoundly the 
organization of every living thing.”* Whether any par- 
ticular investigator is or is not competent to undertake 
this kind of research may be open to question, but I think 
that the study itself needs no further vindication than 
these words of Mr. Wallace. 
In treating of the details of the wing-markings I have 
tried to be intelligible and explicit, even at the cost of 
being somewhat lengthy. I have, however, been obliged 
to content myself with selected examples; a complete 
treatment would run to a vast length, and in most cases 
the lines here laid down may be easily applied to the 
insects not mentioned in this paper. Some of the iden- 
tifications of markings may at first sight seem startling ; 
for instance, that of the straight orange-coloured line 
crossing the disc of the wings in Dercas with the series of 
black spots in the females of Ganoris ; but I believe that 
in every such case it will be found that the homology can 
be certainly traced, step by step. It is hardly necessary 
to point out the importance of being on one’s guard 
against the misleading suggestions of merely superficial 
resemblances, and also of giving due weight to the 
disturbing influence of mimicry. The details of this 
latter process, when minutely examined in a favour- 
able group such as the Pierinx, are seen to be of so 
complicated and interesting a character, that I may 
hope to be excused for having treated of some of 
these details with considerable fulness, and even for 
having ventured to introduce a new term in order to 
distinguish a special case of the phenomenon known as 
“ Convergence.” t 
The generic names employed in this paper are those 
of Mr. Butler in his well-known “ Revision” (Cistula 
Entomologica, vol. i., 1870, p. 88), supplemented by sub- 
sequent memoirs from the hand of the same author, and 
® “On the Papilionide of the Malayan Region,” Trans. Linn. 
Soc., xxv., p. 1 (1866). 
+ See page 298. 
