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Show 1887.] ON THE PROTECTIVE VALUE OF COLOUR IN INSECTS. 191 collection of Butterflies in the Solomon and New Hebrides groups, the details of which it was hoped would be laid before the Society at a future meeting. The following papers were read :- 1. The Experimental Proof of the Protective Value of Colour and Markings in Insects in reference to their Vertebrate Enemies. By E. B. P O U L T O N , M.A., F.Z.S., F.L.S., of Jesus and Keble Colleges, Oxford, Lecturer on Zoology and Comparative Anatomy, St. Mary's Hospital, Paddington. [Received February 23, 1887.] Introductory.-In the preparation of a short course of lectures which were delivered at the Royal Institution in the spring of 1886, I had occasion to work up the historical aspects of m y subject : - " The Nature and Protective Use of Colour in Caterpillars." The results of this inquiry were thus expressed in the introductory part of the first lecture : - " When Darwin was investigating the bright colours of animals, and was elaborating his theory of their explanation as of use in courtship, he came across the brilliant colours of certain caterpillars and saw at once that they were a difficulty in the way of the theory. For caterpillars are undeveloped organisms ; they have been described as ' embryos leading an independent life," and there is no way of distinguishing the sexes by external colour or structure (except in a very few instances). Therefore we here meet with brilliant colours, often rendering the possessors conspicuous, which cannot be of any use in courtship. Seeing therefore that the bright colours must be of use in some other way, Darwin drew the attention of Wallace to the subject, and asked whether he could suggest any explanation. Wallace accordingly thought over the subject, and considered it as part of the wider question of the varied uses (other than sexual) of brilliant and startling colour, in other stages of insect-life and in numerous instances scattered over the whole animal kingdom, and he finally ventured to predict that birds and other enemies would be found to refuse such conspicuous caterpillars if offered to them. He believed, in fact, that such larvse are protected by possessing a nauseous taste or smell, and that it is'to their advantage to become as conspicuous as possible, so that their enemies are warned against a repeated experience of the disagreeable results which follow from tasting them, that in fact the gaudy colouring acts as an indication of something unpleasant about its possessor. It was then pointed out that, as far as experiment had gone, it had entirely confirmed Wallace's prediction. Conversely Wallace argued that larvae which were inconspicuous, being coloured |