Why should any creature, having by the “luck” of variation and heredity acquired some quality—be it strength, pugnacity, sting, or unpleasant taste—which renders it comparatively immune from persecution, proceed to advertise the fact by assuming a gaudy or striking colour? It would surely be better for such an organism to remain inconspicuous. By becoming showy it is visible to every young bird who, not having yet learned that the creature in question is unfit for food, seizes and perhaps kills it. It is true that the young bird vows that never again will it touch another such organism. But of what avail to the dying example of warning colouration is the resolution of the young bird? Moreover, the organism in question, by being conspicuous, also advertises itself to those few enemies which will eat it. There are always, as Professor Poulton justly remarks, animals which are enterprising enough to take advantage of prey which has at least the advantage of being easily seen and caught. Conspicuous Animals Attacked It is possible to cite cases where animals, notwithstanding the fact that they possess natural defences, become the prey of others in some exceptional cases. The salamander can be eaten with comparative impunity by the toad, a creature very likely to meet with it. The toad itself may be eaten; Finn saw the Indian toad (_Bufo melanostictus_) eat another of its own kind. He further observed that the Indian water-snake (_Tropidonotus piscator_) and the “Crow pheasant” cuckoo (_Centropus sinensis_), in the free state, and the Indian Roller (_Coracias indica_) and the Pied Hornbill (_Anthracoceros_), in captivity, eat the warningly-coloured toad. On the other hand, a captive Racket-tailed drongo rejected toads when offered to it. The common cuckoo is well known to feed on hairy and “warningly-coloured” caterpillars. Finn has also seen the glossy cuckoo in Zanzibar devouring black-and-yellow caterpillars. Moreover, in America crows are found to select deliberately highly polished and strongly flavoured beetles. Yet again, wasps are preyed upon by bee-eaters, and also eaten by our common toad. In India, Finn found, by many experiments, that the common garden lizard, or “bloodsucker” (_Calotes versicolor_), would eat, both in captivity and in freedom, all “warningly-coloured” butterflies, not only the _Danainæ_, but even _Delias eucharis_ and the pre-eminently nauseous _Papilio aristolochiæ_. That this reptile is a great enemy to butterflies is rendered probable by the frequent occurrence of specimens of these insects with its semicircular bites in their wings. Further, Finn found that bulbuls, the commonest garden birds in India, ate the _Danainæ_ readily in captivity, even when other butterflies could be had, which was not the case with most other birds. Bulbuls did, however, usually refuse the _Delias_ and _Papilio_ mentioned above.