ILLUSTRATIVE OF NATURAL SELECTION. 179 
relation to those of the surrounding countries; and 
they seem to indicate that climate and other physical 
causes have, in some cases, a very powerful effect in 
modifying specific form and colour, and thus directly 
aid in producing the endless variety of nature. 
Mimicry. 
Having fully discussed this subject in the preceding 
essay, I have only to adduce such illustrations of it, as 
are furnished by the Eastern Papilionide, and to show 
their bearing upon the phenomena of variation already 
mentioned. As in America, so in the Old World, 
species of Danaide are the objects which the other 
families most often imitate. But besides these, some 
genera of Morphide and one section of the genus 
Papilio are also less frequently copied. Many species 
of Papilio mimic other species of these three groups so 
closely that they are undistinguishable when on the 
wing; and in every case the pairs which resemble 
each other inhabit the same locality. 
The following list exhibits the most important and 
best marked cases of mimicry which occur among the 
Papilionidz of the Malayan region and India :— 
Mimickers, Species mimicked. Common habitat, 
DanarIDa. 
pa Papilio paradoxa Euplea meg 
(male & female) (male & female) f S=matra, de. 
2. P. Caunus... ... E. Rhadamanthus. Borneo and Su- 
matyra. 
8. P. Thule ... ... Danais sobrina ... New Guinea. 
4, P. Macareus .. D. Aglaia ... ... Malacca, Java 
N 2 
