Huxley thus hailed the statements of the President in favour of evolution, while the attacks on natural selection he merely met by saying that the address would have made a good subject for discussion in one of the sections, and by insisting with impressive solemnity that evolution was a very different thing from natural selection, thereby implying that the former would be unaffected by the fate of the latter.

The second occasion was between three and four months later, when Huxley spoke at the Anniversary Dinner of the Royal Society, November 30th, 1894, after having been awarded the Darwin Medal at the afternoon meeting. I quote his words from the verbatim report of the Times for December 1st:—

“... I am as much convinced now as I was 34 years ago that the theory propounded by Mr. Darwin, I mean that which he propounded—not that which has been reported to be his by too many ill-instructed, both friends and foes—has never yet been shewn to be inconsistent with any positive observations, and if I may use a phrase which I know has been objected to and which I use in a totally different sense from that in which it was first proposed by its first propounder, I do believe that on all grounds of pure science it ‘holds the field,’ as the only hypothesis at present before us which has a sound scientific foundation.... I am sincerely of opinion that the views which were propounded by Mr. Darwin 34 years ago may be understood hereafter as constituting an epoch in the intellectual history of the human race. They will modify the whole system of our thought and opinion, our most intimate convictions. But I do not know, I do not think anybody knows, whether the particular views which he held will be hereafter fortified by the experience of the ages which come after us; ... whether the particular form in which he has put them before us (the Darwinian doctrines) may be such as is finally destined to survive or not is more, I venture to think, than anybody is capable at this present moment of saying.”

It is unnecessary to say anything about this passage, which fitly sums up and sets the seal on the long series of quotations I have felt obliged to make.

It may not be out of place, however, to state in a few words why many naturalists, including the present writer, are not inclined to accept the extremely cautious and guarded language of one upon whom, with regard to so many other subjects, they have ever looked as their teacher and guide. Concerning the verification of a hypothesis, Huxley said in his lectures to working men (“Darwiniana,” pages 367, 368)—

“... that the more extensive verifications are,—that the more frequently experiments have been made, and results of the same kind arrived at,—that the more varied the conditions under which the same results are attained, the more certain is the ultimate conclusion....”

And again—

“In scientific enquiry it becomes a matter of duty to expose a supposed law to every possible kind of verification, and to take care, moreover, that this is done intentionally, and not left to a mere accident....”

It may well be that the length of time required before an artificially-selected race will exhibit, when interbred with the parent species, phenomena of hybridism similar to those which are witnessed when distinct natural species are interbred—will be fatal to the production of this important line of evidence. But there is nothing to hinder us from holding the reasonable belief that such evidence might be obtained if we had command of the necessary conditions; and in the meantime other evidence of the most satisfactory kind is accumulating, and on a vast scale. Whenever a naturalist approaches a problem in the light of the theory of natural selection, and is able, by its aid, to predict a conclusion which subsequent investigation proves to be correct, he is helping in the production of evidence in favour of the theory. When a naturalist has found the formula “if natural selection be true so-and-so ought to happen” the safest of all guides into the unknown, when it has brought him success many times and in very different directions, when he knows that many other workers in other fields of biological inquiry have had a similarly happy experience, he gradually comes to feel a profound confidence in the permanent truth and the far-reaching importance of the great theory which has served him so well.