Galton says somewhere [35] that great men have long boyhoods. This was certainly true of him, though I should rather describe as youthful the delightful qualities that never faded out of his nature. It is, I believe, the correct thing to speak of the “golden dreams of youth,” and if by this hackneyed phrase we mean a keenly imaginative outlook, a hopefulness with a certain dash about it, a generous courage—tinged with romance—then Francis Galton had undying youth. And this makes his seriously measured progress in eugenics all the more worthy of our admiration.
In one of the Macmillan articles he wrote: “Many plan for that which they can never live to see. At the hour of death they are still planning.”
It was thus that Francis Galton died, and as year after year we meet together on February 16th, let us think of him and his plannings with affection and respect.
III
THE MOVEMENTS OF PLANTS [36]
It is sometimes asserted that the power of movement is a character distinguishing animals from plants. This statement arises to some extent from an obvious confusion of thought. Trees are stationary, they are rooted to one spot, but they are not therefore motionless. We think them so because our eyes are dull—a fault curable with the help of a microscope. And when we get into the land of magnification, where the little looks big and the slow looks quick, we see such evidence of movement that we wonder not to hear as well as see the stream of life that flows before our eyes.
In speaking of the cells of which plants are built, Huxley said that a plant is “an animal enclosed in a wooden box.” It is this prisoner, the living protoplasm, that we may watch pacing round its prison walls. And we may see it stop as though frightened at our rough usage, and then, after a hesitating twitch or two, we see it recover and once more flow round the cell. Or we can watch under the microscope minute free-swimming plants rushing across the field of view, all one way, like a flock of little green sheep that we can drive to and fro with a ray of light for a sheep-dog.
But I am not going to deal with microscopic matters, but rather with things on a bigger scale which can be seen with the naked eye. I will begin by trying to show that very obvious movements are to be seen in every kitchen garden, or in every garret window, where a scarlet runner is grown for its red flowers’ sake.
In a scarlet runner the shoot is not completely vertical, but bends over to one side. To record the movements of the plant a series of photographs may be taken vertically from above the plant, so that the end of the shoot shows like the hand of a watch against a sort of clock-face on which the points of the compass are marked. Such photographs show how the shoot swings round in its instinctive search for another stick to climb.
This well-known movement is performed by a co-ordinated series of curvatures, the exact nature of which need not trouble us now. Let us rather consider the less obvious power of co-ordination which enables a plant to grow upwards in a straight line. Think of a forest of pine trees, hundreds of thousands of them, all growing vertically up towards the sky. Here is a clear case of movement, for the leading shoots were once but a few inches from the ground, and now they are crawling along vertical lines 100 feet up in the air. It may be said that this is mere increase in size, not movement in the ordinary sense. But it may be made plain that the trees could not grow in this way had they not a power of curvature, to which the term movement cannot be refused.
As it is not easy to experiment on pine trees