Page:The Zoologist, 4th series, vol 3 (1899).djvu/562

532 The well-known Tropical American butterflies belonging to the genus Ageronia, which flatten their similarly coloured wings on the lichen-covered trunks, are also described as to "invariably rest head downwards." Mr. Geo. Windsor Earl relates that at Sourabaya he saw Lizards attack large moths, but they were not always successful, "unless they could manage to seize the head, when, after a struggle of a few minutes, the little reptile would bear away his prey to devour at his leisure." Weismann seems more or less of this opinion also, for he observes:—"These markings are composed of two parts, the upper of which is on the fore wings, while the lower one is on the hind wings. The butterfly when at rest must therefore keep the wings in such a position that the two parts of each marking exactly correspond, for otherwise the character would be valueless; and, as a matter of fact, the wings are held in the approximate position, although the butterfly is, of course, unconscious of what it is doing. Hence a mechanism must exist in the insect's brain which compels it to assume this attitude, and it is clear that the mechanism cannot have been developed before the peculiar manner of holding the wings became advantageous to the butterfly, viz. before the similarity to a leaf had made its first appearance." We should opine, however, that the Kallima is exercising some volition in seeking the environment of the withered leaves with which the under surface of its wings approximate, an action we have seen pursued by other butterflies with reference to different surroundings, and that the exact corresponding position of the wings is hereditary, and perhaps now describable as unconscious cerebration, or reflex action. Animals do not all use the same means for protection; the method may be different, but the