details combine to produce a disguise that is so complete and marvellous as to astonish everyone who observes it, and the habits of the insect are such as to utilise all these peculiarities, and render them available in such a manner as to remove all doubt of the purpose of this singular case of mimicry, which is undoubtedly a protection to the insect. Its strong and swift flight is sufficient to save it from its enemies when on the wing, but if it were equally conspicuous when at rest it could not long escape extinction, owing to the attacks of the insectivorous birds and reptiles that abound in the tropical forests.”[104] Dr. Wallace then speaks of another closely allied species which is common in India, on the under surface of whose wings there are sometimes, to the boot of all that has been described, in the way of disguise, “patches and spots formed of small black dots, so closely resembling the way in which minute fungi grow on leaves that it is almost impossible, at first, not to believe that fungi have grown on the butterflies themselves.”[104] The minuteness of a resemblance like this is really very surprising, for it seems as though the butterfly-hunting bird or insect—some powerful wasp may represent the latter—was capable of minutely examining the object in question, and saying to itself, as it were, “I don’t think that can be a leaf, because there are no black spots upon it,” or _vice versâ_. In reality, however, it is no doubt the general effect, to which every detail contributes, that tells. What such resemblances do seem to me to show—and this, I think, is a new idea—is the accuracy and precision of some insects’ sight. How insects see things has long been a question, and many, I suppose, think it quite uncertain whether a leaf, for instance, throws the same picture on their retina that it does on ours. But if, to deceive them, the copy must be such that it also deceives us, is it not clear that it does? Otherwise the effect of the original could probably be reproduced by a less accurate copy. How little, after all, does the finest painting really resemble nature! The effect alone does so, not the means by which it is arrived at. Surely, then, if an insect, looking at a leaf or any other object, received but a general impression of colour, with an outline more or less blurred, or ill-defined, these copies of nature by nature—made to deceive—would bear witness to the fact. A study of protective resemblances is perhaps the best way of forming an idea as to how creatures, other than ourselves, see the world. It is even possible that such resemblances exist, which we, because we see things differently, are totally incapable of detecting.