Azurite, the blue mineral which often accompanies malachite is likewise a hydrous carbonate of copper and occasionally occurs so that it can be used with malachite for ornamental purposes.
Oliver Cummings Farrington.
LEAF BUTTERFLY (INDIA).
(Kallima paralekta).
Life-size.
FROM COL. F. M. WOODRUFF.
THE LEAF BUTTERFLY.
(Kallima paralekta.)
There are many instances of protective imitation or mimicry in nature, but none are more pronounced, more perfect or more interesting than that shown by the leaf butterflies. Briefly defined, the phenomenon of mimicry is that relation which obtains when “a certain species of plants or animal possesses some special means of defense from its enemies and some other species inhabiting the same district or a part of it, and not itself provided with the same special means of defense, closely resembles the first species in all external points of form and color, though often very different in structure and unrelated in the biological order.” Many animals, such as some tree-lizards, resemble the colors of the environment in which they live, either for protection from enemies or in order that they may more easily catch their prey. Some arboreal snakes hang from the boughs of trees like the drooping ends of creeping vines.
The coloring of the under surface of the wings of the leaf butterflies very closely resembles the color of a dried leaf. As dried leaves vary in color and appearance, so do the butterflies vary in the color and markings of their wings. It is said that even in the same species, the under surface of the wings may be of various shades of brown, yellow, ash and red. But the imitation of the dried leaf does not alone rest on the color, for often, here and there, may be seen small groups of dark colored spots which strikingly resemble the patches of fungi that are so common on leaves. The mimicry of this butterfly is purely protective and not for the purpose of deceiving its prey.
Dr. Alfred Russel Wallace in his “Malay Archipelago” writes of this butterfly as he found it in its native element. He says, “This species was not uncommon in dry woods and thickets, and I often endeavored to capture it without success, for after flying a short distance it would enter a bush among dry or dead leaves, and however carefully I crept up to the spot, I could never discover it till it would suddenly start out again, and then disappear in a similar place. 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 at length discovered 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 certain 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 ends of the upper wings terminate 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 inner side toward 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 habit of the species is always to rest on a dead twig and among dead or dried 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 wing 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 fibers 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, 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 tropical forests.”