384 
TROPICAL NATURE 
v 
yet, as none of these groups are known to be specially pro- 
tected, this can hardly be true mimicry. A few species of 
two other genera in the same country (Eunica and Siderone) 
also reproduce the same colours, but with only a general 
resemblance in the markings. Yet again, in tropical America 
we have species of Apatura which, sometimes in both sexes, 
sometimes in the female only, exactly imitate the peculiar 
markings of another genus (Heterochroa) confined to America ; 
here, again, neither genus is protected, and the similarity 
must be due to unknown local causes. 
But it is among islands that we find some of the most 
striking examples of the influence of locality on colour, 
generally in the direction of paler, but sometimes of darker 
and more brilliant hues, and often accompanied by an unusual 
increase of size. Thus in the Moluccas and New Guinea we 
have several Papilios (P. euchenor, P. ormenus, and P. tydeus) 
distinguished from their allies by a much paler colour, espe- 
cially in the females, which are almost white. Many species 
of Danais (forming the subgenus Ideopsis) are also very pale. 
But the most curious are the Euploeas, which in the larger 
islands are usually of rich dark colours, while in the small 
islands of Banda, K6, and Matabello at least three species not 
nearly related to each other (E. hoppferi, E. euripon, and E. 
assimilata) are all broadly banded or suffused with white, 
their allies in the larger islands being in each case very much 
darker. Again, in the genus Diadema, belonging to a dis- 
tinct family, three species from the small Aru and Ke islands 
(D. deois, D. hewitsonii, and B. polymena) are all more 
conspicuously white-marked than their representatives in the 
larger islands. In the beautiful genus Cethosia, a species 
from the small island of Waigiou (0. cyrene) is the whitest of 
the genus. Prothoe is represented by a blue species in the 
continental island of Java, while those inhabiting the ancient 
insular groups of the Moluccas and New Guinea are all pale 
yellow or white. The genus Brusilla, almost confined to these 
islands, comprises many species which are all very pale; 
while in the small island of Waigiou is found a very distinct 
genus, Hyantis, which, though differing completely in the 
neuration of the wings, has exactly the same pale colours and 
large ocellated spots as Drusilla. 
