A Parable.
A plain parable may well conclude this chapter.
As I mused on the chain of life I found a piece of whipcord which had been lying by for twenty-five years since some of it was used for rigging a model yacht, and this very efficient product of human art seemed to speak to me on the subject of my musings. Perhaps if Huxley could extract from a piece of chalk or lumps of coal two magnificent expositions on geology and biology, this little trifle of cord might afford a text on a way of looking at living things which should be useful in this old case of Lamarck v. Weismann—and others.
Should I learn the story of the whipcord forwards like an annalist, or backward like a modern historian? Clearly it could be done in a measure by either method. Here was a highly finished product of which either might furnish the story, and of which, we may suppose, I knew nothing. I tried the backward way, and by the aid of a needle began to unravel it. The cord was as good as if just made, slender, strong, twisted, with some glazing on the twisted threads. It showed three main bundles, and each of these was composed of two smaller ones. The substance of all these six was found when examined with a lens to consist of minute silky fibres varying from a quarter of an inch to an inch in length. This was all I could learn without a stronger magnifying power or a chemical analysis, and the direct search was at an end. I gathered since then that the first three bundles were called “strands,” and the two composing each of these “yarns,” and that the fibres were from a plant called hemp. This did not carry the story deep or far, and illustrates how often in the backward method facts have to be supplemented by inference. But I had learnt some undoubted facts and some inferences from them nearly as certain. Some mind of man had conceived and hands carried out the division of the bundles of fibres into three strands, had twisted them somehow so as to reduce their length by a quarter and yet not far enough to rupture them, and had thus fitted them the better for their purpose by a reinforcement of tensile strength due to the twisting. I could also see that this same mind had seen it better to divide each of these strands into two yarns before the final twisting, and that in framing the yarns the silky fibres of the plant had been squeezed together by some powerful agency and yet not disintegrated, and that the finished product had been immersed in a protective substance which gave it a slight glaze. In short, I, though a child in these matters, read much of the story of this cord in terms of mind dealing with given organic matter. I may add that I did not imagine myself a little Paley, and that I do not intend to “take in” the reader as to the argument from design and final causes, even though this parable may feebly resemble Paley’s study of a watch. The conclusion was perfectly clear that certain directing grey cells of a certain brain had interfered with and acted upon some plastic vegetable matter, and one could at the “strand” stage, the “yarn” stage, and the “fibre” stage see mind writ large.
The Forward Way.
The limits of the former method are obvious, but I might also attempt to follow the little story as a crime is followed and described by eye-witnesses. So I go to an old-fashioned rope-factory and ask the foreman questions about the making of twine, cords, ropes and cables. He shows me bundles of hemp; he calls them Russian, Italian or American, and goes on to tell me how the fibre is “heckled” or combed, how “tow” is separated from “line,” and how the yarns are pressed together and twisted, how they are at first rough and bristly, and are then dressed, polished, and “sized” with such a starch as that of the potato. When I proceed to ask him about the plant itself his interest flags, and he becomes vague. He says, “You had better ask the Head, young Mr. X., he knows these things better.” I find the Head with his golf clubs over his shoulder and about to start on his “business,” and he is polite, but says he knows very little about the origin of his hemp. “You should go over the way and ask Messrs. Y. if they will let you see the expert who advises them in their business, he will know.” The expert is at home and kindly and fully describes to me the early home of the wild Cannabis Sativa in a moderate climate of Asia, the rich soil it needs for its growth and the various countries of the world into which it has been introduced; and the bast-fibres of the bark of this plant which from remote antiquity has supplied the silky stuff. He then tells me how the stems are dried and crushed, and then of the important stage of fermentation or “retting” in water, how they are again beaten in a “break,” then rubbed and “scutched,” and finally “heckled” or combed; and, as to analytic chemistry, he tells me that the chief constituent is cellulose. This quest is now over and I know much I could not find out by the backward method, though the dependence of its rival upon the presence of honest and capable eye-witnesses is not less obvious. It is not alone in ecclesiastical history that cheats and forgers of documents exist. In the world of Nature there may be, for all we know, biological False Decretals that may lead us far astray, such perhaps as Amphioxous and Archæopteryx, and the Pseudo-Isidore who produced them may yet be discovered.
CHAPTER II.
REVIEW OF THE POSITION
The modern story of the theory of organic evolution shows certain important dates—1859, 1880, 1894, 1895, 1899 and 1909. These begin with the Origin of Species and end with the publication of a volume in commemoration of its jubilee, when most of the leading students of evolution united to render homage to Darwin. The year 1859 has been so often and so worthily treated that it is enough here to say that the fifty years between the issue of the work of Darwin and Wallace and 1909 saw a greater revolution in biology, speculative and practical, than any period so relatively brief had ever seen.