Page:The Zoologist, 4th series, vol 4 (1900).djvu/578

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THE ZOOLOGIST.

directions. This may even occur in an unexpected way, as in the observation of Col. Pollok, cited by Mr. Distant, that the Tiger has not yet learnt that in pursuit of game nothing can be done down wind. Considerations such as these must lend a certain measure of support to the mechanical conception of natural selection. Thus, in the matter of conscious resemblance, although many animals may show undoubted intelligence in other directions, it is highly probable that, in the great majority of cases, their reasoning powers would not be sufficient to enable them to decide whether, or no, their own colouring would have a protective value in any new or unusual environment. It is far more reasonable to suppose that such knowledge as they may have in this respect would be acquired through their experience of their liability to, or immunity from, attack under such conditions, quite apart from any colour considerations. The former process would be a true instance of "active mimicry," as defined by Mr. Distant, but the latter cannot be included under that term; indeed, in such cases, experience in the individual is the equivalent of natural selection in the species.

In the preliminary portion of his paper, Mr. Distant has given us many excellent examples and arguments to show that mimicry and protective resemblance probably existed in very remote antiquity;(n10) and he has done well in drawing attention to the matter, which is apt to be overlooked. But I must certainly join issue with him when he states that: "The present attitude of many champions of the cause, who seek to find, or to invent, present factors for producing these phenomena, seems fraught with peril for the whole theory; and, with the same weariness and perseverance with which the original promulgators thought out the doctrine, we must go on searching for further proofs, which will necessitate our appealing to the Cæsar of the past—the ever-growing science of palæontology" (l.c., p. 302). I must confess that this appears to me to be a very remarkable assertion. In the first place, the vast majority of cases generally referred to mimicry and resemblance are concerned with colour and movement alone, structure playing but a very subordinate part therein.[1] Mr. Distant has himself been at some pains to show the very evident futility of appealing to

  1. The point discussed was the structural characters of the Phasmidæ. The exact quotation requires this antecedent: "We still have abundant reason for believing that, though the protective resemblance of these Phasmidæ was already acquired in Carboniferous times, the presence of Amphibia in an evolutionary sense is quite sufficient to account for it. This prompts two reflections: one, that we ought to look a long way back for the origins of these protective and mimetic guises; and the other, that we may reasonably hope to find them" (p. 302).—Ed.