Page:Popular Science Monthly Volume 75.djvu/573

Rh have expected to find all species of the classes above referred to proving to be by one means or another at the minimum of recognizability as animals, and at the same time, at a corresponding minimum of palatability; and behold, that is just what we find! We find in the very ranks of the supposed mimetics (a term which asserts a protection involving conspicuousness of the protected individual) the actual climax of invisibility, as Bates practically testifies in the above extract, and as I too, and all others who have studied these insects in their homes, must testify. (In deep forest shades the actual illumination is faint, and objects show most when they come between the beholder and regions of more lighted foliage beyond or up nearer the forest's top. In these circumstances all rank patterns are potent to thwart the revealing-power of silhouette, and behold, here we find the very prince of silhouette thwarters—transparency itself!)

As to the impression that "flaunting flight" (i. e., slow or weak flight), gaudy costume and unpalatability keep together, they do not do this to any very impressive degree, as the accompanying table will remind the student. Entomologists will see that this table is sufficiently correct for my purpose.

In fact, one finds, as one would have expected, that every butterfly has the gait best suited to the kind of place that he lives in. Heliconius, one of the very slowest genera on our continent, is particularly at home while flying through the densest copses. It is perfectly natural that such a butterfly as a grapta, matched to the colors of the ground, should hurry, in flying from one safe spot on the ground to another, but the case of Heliconius is very different. He lives in cover, the very kind of cover to which small birds fly from a hawk, and through this he sails and flits in the only conceivable manner, threading its minute alleys with short wing beats, and at times almost seeming to stop and crawl through the narrowest places. This is, at least, true of charitonius. sara and melpomene, in the West Indies and Trinidad, where I have seen them. As is characteristic of all nature, these insects overflow from the situations that most nurture them into less favorable places.

Yet it is almost a sufficient answer to the natural question why they are not there preyed upon, to point out afresh that on the American continent, at least, no kind of butterfly at all appears often to be attacked on the wing. In Trinidad, one of the keenest of that