It is probable that no evolutionist would deny that there must be a certain measure of truth in the contention that some animals are capable of appreciating the protective value of their colouring;(n3) for, apart from observational evidence on the point, we should antecedently expect a certain amount of reasoning power in this direction according to the ordinary principles of evolution. The question is, however, whether, in the suggestions under consideration, this power has not been considerably over-estimated. An examination of the examples referred to "active mimicry" would certainly lead to this conclusion, for the arguments used in these instances are equally applicable to every case of protective or aggressive resemblance. There would be little difficulty in demonstrating the untenability of such a position, but this is unnecessary, as we are expressly warned that the suggestion of active mimicry must not be made too absolute, although no suggestion is offered as to its probable limits.
It may, perhaps, be possible to define roughly certain limits within which such consciousness cannot be recognised. Resemblances have been aptly divided by Prof. Poulton into two categories, viz.: "Special Resemblance, in which the appearance of a particular object is copied in shape and outline as well as in colour; and General Resemblance, in which the general effects of surrounding colours are reproduced" ('Colours of Animals,' p. 24); and in connection with this distinction it is interesting to note that in the most intelligent section of the animal kingdom, namely, the higher vertebrates, we find little but general resemblances, and the lower we go in the scale of intelligence, the more frequently do we observe special resemblances, that is, where colour is utilised for protective purposes.(n5) But, quite apart from this, it is evident that it is practically impossible to include cases of special resemblance under the term "active mimicry," as here discussed.
Distant replies that "This is a cardinal doctrine in natural and apologetic theology, but is the very antithesis of science, natural or otherwise. The man who orders his whole life on probabilities will probably arrive at the conclusion that hope is a very good breakfast, but a most indifferent dinner." Prof. Tyler's remark appears to my mind as a sufficiently evident truth, but I may perhaps be permitted to adduce in its support the opinion of so virile a thinker as the late Prof. Huxley, who says: "We find, practically, that expectations, based upon careful observations of past events, are, as a rule, trustworthy. We should be foolish indeed not to follow the only guide we have through life. But, for all that, our highest and surest generalizations remain on the level of justifiable expectations, that is, very high probabilities." ('Collected Essays,' vol. v. p. 204.)
On the other hand, Prof. Huxley, in thanking Bateson for his well-known volume on 'Variation,' writes how glad he is to see "that we are getting back from the region of speculation into that of fact again" ('Life and Letters,' vol. ii. p. 372).— Ed.
