Page:George Archdall Reid 1896 The present evolution of man.djvu/96

84 same time at the other end of the wood. It would be a mere chance if they ever knew of each other's existence—a still more unlikely chance that they should resist on both sides all temptations to a less advantageous alliance. But unless they did so the new breed would never even begin, let alone the question of its perpetuation after it had begun. I think Professor Weismann is justified in saying that we cannot, either with more or less ease, imagine the process of Natural Selection."—Nature, August 9, 1894.

I think we can with considerable ease imagine the process of evolution. So far from being purely hypothetical, geology and embryology render it certain. No man has seen it at work among the higher species of plants and animals to which the attention of Lord Salisbury, like that of the rest of the general public, is directed, for since it normally proceeds on lines of minute variations, not on lines of great abnormalities, no man is able to observe a sufficient number of generations; but any man may observe its operation among the lower plants and animals (e.g. among the short-lived microbes of disease), and scores of men, as will be seen, have recorded their observations as regards these latter. Even artificial selection usually proceeds on lines of normal variations. For instance, among cattle and pigeons, the domesticated animals Lord Salisbury specially quotes, how many peculiarities that are examples of evolution, not of retrogression, have been otherwise developed. When he speaks of two individuals accidentally blessed with the same variation, he is alluding of course to abnormal inborn variations. It is certainly improbable that two individuals should exhibit the same abnormality at the same time; it is still more improbable that they should meet and interbreed if they do; and even more improbable that the abnormality should be of such a nature as to enable