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540 would eventually supersede those whose instincts were not so well in harmony with their colouration. On the other hand, for the suggestion of "active mimicry," it is contended that the actions of these insects are apparently so purposive that it is difficult to believe that they are not due to "conscious volition" on their part; and, in support of this contention, a large number of other similar cases are adduced, all, be it noted, equally, or more fully, I consider, explicable on the theory of natural selection. But when we stop to enquire why, or how, these butterflies have developed this peculiar colouration, the supporters of the suggestion of "active mimicry" can vouchsafe us no reply. According to this suggestion, the tiger selects the bamboo-thicket, the leopard the leafy forest, and the lion the open veldt, simply because they have individually discovered, by their own reasoning powers, that these respective localities are best suited to their particular styles of colouration; and the question why one is striped, another spotted, and the third unicolourous, reverts to an open problem. Thus all the beautiful explanations of adaptive colouring, afforded us by Darwin's grand conception, are to be thrown to the winds if "active mimicry" be logically applied.

It will be thus seen that it is only among the most generalised types of resemblance that we may seek for signs of conscious adaptation, as opposed to quasi-mechanical instincts. But even here the foregoing objection also applies, though with less force, since the contention of coincidence may be put forward in some cases, as indicated by Mr. Romanes. But it must be borne in mind that this contention is nothing but an argument from ignorance, and, as such, is not scientifically permissible where any other reasonable and adequate explanation can be advanced. The mere citation of a number of instances of protective colouring, however purposive the actions of the animals may appear, are in themselves no proof of conscious resemblance; neither do they in any way weaken the theory of natural selection in this regard; for this theory not only consistently explains the reasons for, and the development of, the colouration, but also accounts for that very purposiveness upon the occurrence of which the former proposition is alone based. Again, in the case of special resemblances, if it be conceded, as a result of the arguments adduced above, that both the morphological and psychological characters have been contemporaneously perfected through the mechanical action of natural selection (and in fact the structural peculiarities cannot well be explained on this principle without the instincts), then this alone would form strong