Against this it should be remembered that there is always an antecedent probability that several specimens of a given variation would appear at one time and place. This would probably be the case even on Mr. Darwin’s hypothesis, that the variations are fortuitous; if they are mainly guided by sense of need and intelligence, it would almost certainly be so, for all would have much the same idea as to their well-being, and the same cause which would lead one to vary in this direction would lead not a few others to do so at the same time, or to follow suit. Thus we see that many human ideas and inventions have been conceived independently but simultaneously. The chances, moreover, of specimens that have varied successfully, intermarrying, are, I think, greater than the reviewer above quoted from would admit. I believe that on the hypothesis that the variations are fortuitous, and certainly on the supposition that they are intelligent, they might be looked for in members of the same family, who would hence have a better chance of finding each other out. Serious as is the difficulty advanced by the reviewer as against Mr. Darwin’s theory, it may be in great measure parried without departing from Mr. Darwin’s own position, but the “little dose of judgement and reason” removes it, absolutely and entirely. As for the reviewer’s shipwrecked hero, surely the reviewer must know that Mr. Darwin would no more expect an island of black men to be turned white, or even perceptibly whitened after a few generations, than the reviewer himself would do so. But if we turn from what “might” or what “would” happen to what “does” happen, we find that a few white families have nearly driven the Indian from the United States, the Australian natives from Australia, and the Maories from New Zealand. True, these few families have been helped by immigration; but it will be admitted that this has only accelerated a result which would otherwise, none the less surely, have been effected.
There is all the difference between a sudden sport, or even a variety introduced from a foreign source, and the gradual, intelligent, and, in the main, steady, growth of a race towards ends always a little, but not much, in advance of what it can at present compass, until it has reached equilibrium with its surroundings. So far as Mr. Darwin’s variations are of the nature of “sport,” _i.e._, rare, and owing to nothing that we can in the least assign to any known cause, the reviewer’s objections carry much weight. Against the view here advocated, they are powerless.