a 
NATURAL SELECTION 
IT] 
of rich orange on a deep-bluish ground. The under side is 
very variable in colour, so that out of fifty specimens no two 
can be found exactly alike, but every one of them will be of 
some shade of ash or brown or ochre, such as are found 
among dead, dry, or decaying leaves. The apex of the upper 
wings is produced into an acute point, a very common form 
in the leaves of tropical shrubs and trees, and the lower 
wings are also produced into a short narrow tail. Between 
these two points runs a dark curved line exactly representing 
the midrib of a leaf, and from this radiate on each side a few 
oblique lines, which serve to indicate the lateral veins of a 
leaf. These marks are more clearly seen on the outer por- 
tion of the base of the wings, and on the inner side towards 
the middle and apex, and it is very curious to observe how 
the usual marginal and transverse striae of the group are here 
modified and strengthened so as to become adapted for an 
imitation of the venation of a leaf. We come now to a still more 
extraordinary part of the imitation, for we find representations 
of leaves in every stage of decay, variously blotched and mil- 
dewed and pierced with holes, and in many cases irregularly 
covered with powdery black dots gathered into patches and spots, 
so closely resembling the various kinds of minute fungi that 
grow on dead leaves that it is impossible to avoid thinking at 
first sight that the butterflies themselves have been attacked 
by real fungi. 
But this resemblance, close as it is, would be of little use 
if the habits of the insect did not accord with it. If the 
butterfly sat upon leaves or upon flowers, or opened its wings 
so as to expose the upper surface, or exposed and moved its 
head and antennae as many other butterflies do, its disguise 
would be of little avail. We might be sure, however, from 
the analogy of many other cases, that the habits of the insect 
are such as still further to aid its deceptive garb ; but we are 
not obliged to make any such supposition, since I myself had 
the good fortune to observe scores of Kallima paralekta, in 
Sumatra, and to capture many of them, and can vouch for the 
accuracy of the following details. These butterflies frequent 
dry forests and fly very swiftly. They were never seen to 
settle on a flower or a green leaf, but were many times lost 
sight of in a bush or tree of dead leaves. On such occasions 
