I do not know what Mr. Belloc’s mathematical attainments are, or indeed whether he has ever learnt to count beyond zero. There is no evidence on that matter to go upon in these papers. But one may suppose him able to understand what an average is, and he must face up to the fact that the characteristics of a species are determined by its average specimens. This dickering about with fancy stories of abnormal nuptials has nothing to do with the Theory of Natural Selection. We are dealing here with large processes and great numbers, secular changes and realities broadly viewed. I must apologise for pressing these points home. But I think it is worth while to take this opportunity of clearing up a system of foggy misconceptions about the Theory itself that may not be confined altogether to Mr. Belloc. MR. BELLOC COMES TO HIS EVIDENCE And now let us come to Mr. Belloc’s second triad of arguments--his arguments, as he calls them, “from Evidence.” The sole witness on Evidence called is his own sturdy self. He calls himself into the box, and I will admit he gives his testimony in a bluff, straightforward manner--a good witness. He says very properly that the theory of Natural Selection repudiates any absolute fixity of species. But we have to remember that the rate of change in any species is dependent upon the balance between that species and its conditions, and if this remains fairly stable the species may remain for as long without remarkable developments, or indulge in variations not conditioned by external necessities. The classical _Lingula_ of the geological text-books, a warm-water shell-fish, has remained much the same creature throughout the entire record, for hundreds of millions of years it may be. It was suited to its submarine life, and hardly any variation was possible that was not a disadvantage. It swayed about within narrow limits. This admission of a practical stability annoys Mr. Belloc; it seems to be a mean trick on the part of the Theory of Natural Selection. He rather spoils his case by saying that “according to Natural Selection” the swallow ought to go on flying “faster and faster with the process of time.” Until it bursts into flames like a meteor and vanishes from our world? And the _Lingula_ ought to become more and more quiescent until it becomes a pebble? Yet plainly there is nothing in the Theory of Natural Selection to make the swallow fly any faster than its needs require. Excess of swiftness in a swallow may be as disadvantageous as jumping to conclusions can be to a controversialist. But here is a statement that is spirited and yet tolerably fair:-- “If Natural Selection be true, then what we call a Pig is but a fleeting vision; all the past he has been becoming a Pig, and all the future he will spend evolving out of Pigdom, and Pig is but a moment’s phase in the eternal flux.”