60 MIMICRY, AND OTHER PROTECTIVE 
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 
strie 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 re- 
presentations of leaves in every stage of decay, 
variously blotched and mildewed 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 butterilies 
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 
