[39] The twin metaphor here chosen for the name of a complex natural process should be cleared a little of a certain obscurity of meaning. A mould is familiar to all in domestic and industrial matters, but there are two sides to the metaphorical conception. A plastic object may be moulded by the hand of man as in his ruder, but more laborious days, or it may be pressed into an artificial mould that he has made by means of his hands and tools. One of these we know in the rude pottery made by prehistoric man and the vessel of the potter described by Jeremiah the prophet. We know also those machine-made moulds, so accurate as to be fitted for the coinage of a nation and able to puzzle a clever coiner who tries to copy them. We know the rough hewing of the stone by the sculptor which follows his moulding of the clay. And in Sacred Writ we read of a double process when the Hebrews not content with their object of worship took the golden ear-rings of their women and Aaron “received them at their hand and fashioned it with a graving tool, after he had made it a molten calf.” But as no conception of a mould in biological matters, which connotes the rigid accuracy of the coiner’s mould, can represent the truth, the rougher and freer meaning of the term is here employed. A similar double meaning is implicit in the metaphor of the sieve, considered as a human utensil. I believe we owe this idea of a sieve to Professor Thomson, but am not sure on this point. But I have not been able to find any definition as to the way in which the sieve of natural selection is held to act. A sieve is of course for sifting substances, and the size of the mesh is adapted by us for the purpose we have in view. We may want a sieve to hold back for us the fit or good and allow the unfit or bad to pass through, for example wheat and chaff, or we may employ it to separate sand for our purposes from fine gravel. The former is of course the most common of the purposes for which a sieve is used. So here the comparison of personal selection with the action of a sieve agrees with this aspect of a sieve, the fit being retained and the unfit allowed to pass through, thus agreeing with that view of Spencer’s of the survival of the fittest which is held by most authorities to be more accurate than Darwin’s Natural Selection.
[40] Jevons.
[41] British Association of Science 1902. Zoological Section.
[42] Darwin and after Darwin, Vol. 1, p. 90.
[43] The Descent of Man, Chap. VI., p, 151.
[44] I may remark that Darwin seems at an earlier date to have made a very curious suggestion in this connection, for Hartmann, in his work on Anthropoid Apes, p. 99, quotes him as saying: “We should, however, bear in mind that the attitude of an animal may perhaps be in part determined by the direction of the hair; and not the direction of the hair by the attitude,” a notion so obviously untenable that it does not appear in the second edition of The Descent of Man, 1896.
[45] This was written before the publication of Professor Woods-Jones’ book Arboreal Man.
[46] Prehistoric Man and His Story, p. 60
[47] Blinkers ought long ago to have gone the way of bearing-reins for draught horses. If a riding horse does not need them, no more need a draught horse be thus insulted, for very little intelligence and patience on the part of their drivers would have educated their excellent brains into indifference towards startling objects.
[48] Descent of Man, p. 19.