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PDF - Wallace Online

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44 NATURAL SELECTION inof rich orange on a deep-bluish ground. The under side isvery variable in colour, so that out of fifty specimens no twocan be found exactly alike, but every one of them will be ofsome shade of ash or brown or ochre, such as are foundamong dead, dry, or decaying leaves. The apex of the upperwings is produced into an acute point, a very common formin the leaves of tropical shrubs and trees, and the lowerwings are also produced into a short narrow tail. Betweenthese two points runs a dark curved line exactly representingthe midrib of a leaf, and from this radiate on each side a fewoblique lines, which serve to indicate the lateral veins of aleaf. These marks are more clearly seen on the outer portionof the base of the wings, and on the inner side towardsthe middle and apex, and it is very curious to observe howthe usual marginal and transverse striae of the group are heremodified and strengthened so as to become adapted for animitation of the venation of a leaf. We come now to a still moreextraordinary part of the imitation, for we find representationsof leaves in every stage of decay, variously blotched and mildewedand pierced with holes, and in many cases irregularlycovered with powdery black dots gathered into patches and spots,so closely resembling the various kinds of minute fungi thatgrow on dead leaves that it is impossible to avoid thinking atfirst sight that the butterflies themselves have been attackedby real fungi.But this resemblance, close as it is, would be of little useif the habits of the insect did not accord with it. If thebutterfly sat upon leaves or upon flowers, or opened its wingsso as to expose the upper surface, or exposed and moved itshead and antennae as many other butterflies do, its disguisewould be of little avail. We might be sure, however, fromthe analogy ofmany other cases, that the habits of the insectare such as still further to aid its deceptive garb but we are;not obliged to make any such supposition, since I myself hadthe good fortune to observe scores of Kallima paralekta, inSumatra, and to capture many of them, and can vouch for theaccuracy of the following details. These butterflies frequentdry forests and fly very swiftly. They were never seen tosettle on a flower or a green leaf, but were many times lostsight of in a bush or tree of dead leaves. On such occasions

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