suddenly start out again and then disappear in a similar place. If at length I was
fortunate enough to see the exact spot where the butterfly settled, and though I
lost sight of it for some time, I would discover that it was close before my eyes,
but that in its position of repose it so closely resembled a dead leaf attached to a
twig as almost certainly to deceive the eye even when gazing full upon it. I
captured several specimens on the wing, and was able fully to understand the
way in which this wonderful resemblance is produced.
The end of the upper wings terminates in a fine point, just as the leaves of
many tropical shrubs and trees are pointed, while the lower wings are somewhat
more obtuse, and are lengthened out into a short thick tail. Between these two
points there runs a dark curved line exactly representing the midrib of a leaf, and
from this radiate on each side a few oblique marks which well imitate the lateral
veins. These marks are more clearly seen on the outer portion of the base of the
wings, and on the innerside towards the middle and apex, and they are produced
by striae and markings which are very common in allied species, but which are
here modified and strengthened so as to imitate more exactly the venation of a
leaf. The tint of the undersurface varies much, but it is always some ashy brown
or reddish colour, which matches with those of dead leaves. The habit of the
species is always to rest on a twig and among dead or dry leaves, and in this
position with the wings closely pressed together, their outline is exactly that of a
moderately-sized leaf, slightly curved or shrivelled. The tail of the hind wings
forms a perfect stalk, and touches the stick while the insect is supported by the
middle pair of legs, which are not noticed among the twigs and fibres that
surround it. The head and antennae are drawn back between the wings so as to
be quite concealed, and there is a little notch hollowed out at the very base of the
wings, which allows the head to be retracted sufficiently. All these varied details
combine to produce a disguise that is so complete and marvellous as to astonish
everyone who observes it; and the habits of the insects are such as to utilize all
these peculiarities, and render them available in such a manner as to remove all
doubt of the purpose of this singular case of mimicry, which is undoubtedly a
protection to the insect.
Its strong and swift flight is sufficient to save it from its enemies when on the
wing, but if it were equally conspicuous when at rest it could not long escape
extinction, owing to the attacks of the insectivorous birds and reptiles that
abound in the tropical forests. A very closely allied species, Kallima inachis,
inhabits India, where it is very common, and specimens are sent in every
collection from the Himalayas. On examining a number of these, it will be seen
that no two are alike, but all the variations correspond to those of dead leaves.