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in PROTECTIVE RESEMBLANCES AMONG ANIMALS 43the same time drawing in their legs and antennae, which fit soperfectly into cavities for their reception that the insectbecomes a mere oval brownish lump, which it is hopeless tolook for among the similarly coloured little stones and earthpellets among which it lies motionless.The distribution of colour in butterflies and moths respectivelyis very instructive from this point of view. Theformer have all their brilliant colouring on the upper surfaceof all four wings, while the under surface is almost alwayssoberly coloured, and often very dark and obscure. Themoths on the contrary have generally their chief colour onthe hind wings only, the upper wings being of dull, sombre,and often imitative tints, and these generally conceal thehind wings when the insects are in repose. This arrangementof the colours is therefore eminently protective, becausethe butterfly always rests with his wings raised so as to concealthe dangerous brilliancy of his upper surface. It isprobable that if we watched their habits sufficiently we shouldfind the under surface of the wings of butterflies very frequentlyimitative and protective. Mr. T. W. Wood haspointed out that the little orange-tip butterfly often rests inthe evening on the green and white flower heads of anumbelliferous plant, the wild 1chervil, and that when observedin this position the beautiful green and white mottling of theunder surface completely assimilates with the flower headsand renders the creature very difficult to be seen. It isprobable that the rich dark colouring of the under side of ourpeacock, tortoiseshell, and red-admiral butterflies answers asimilar purpose.Two curious South American butterflies that always settleon the trunks of trees (Gynecia dirce and Callizona acesta)have the under surface curiously striped and mottled, andwhen viewed obliquely must closely assimilate with the appearanceof the furrowed bark of many kinds of trees. But the mostwonderful and undoubted case of protective resemblance in abutterfly which I have ever seen, is that of the common IndianKallima inachis, and itsMalayan ally, Kallima paralekta.The upper surface of these insects is very striking and showy,as they are of a large size, and are adorned with a broad band1Antlmscus sylvestris.