I was interested last autumn in the pathetic struggle of a humble little Chenopodium album that had started life late and under unfavorable circumstances. It came up in September under the north piazza near the beaten foot path; close up to the building. I was first attracted by the fact that, though it was not over a foot high, it had bloomed and was making seed at a desperate rate, while its sisters earlier in the season reached several feet in height before blooming. But, alas! for the vanity of the poor little creature, the cold weather during the Christmas holidays came on, and the steam being shut off, the side of the building grew cold and my struggling little friend was frozen, and soon its lifeless remains were the sport and derision of the rude January winds. I pitied the poor little vagabond despite the bad record of her family. Indeed plants, like people, must suffer sometimes because of an evil ancestry. In this case I was touched by the pathos of the situation, and really hoped the pertinacious little wretch might proudly scatter her well-matured seed upon the hard-beaten path as an inspiration to the many boys that passed daily, grumbling because of the hardness of their lot. But the only moral I can now draw is the foolishness of delaying in the right start.
Sometimes the supply of light-energy is so great that the little chlorophyll machines cannot use it in their legitimate work, nor does the plant use it in preparing the warming-up color. Then the disc-shaped corpuscles turn their edges instead of their flat surfaces to the light, or sometimes move deeper down into the leaf. In some cases the leaf itself turns edgewise instead of broadside to the sun.
There are many plants so constituted that they cannot live from year to year in our northern climate, and they must make some provision for preserving their species, and right cunningly do they do this. At a certain period of its growth the potato, for example, puts its starch-making machinery to work on full time, and hurries the starch down below the surface of the ground, and stores it up in what we call a tuber. These tubers have stored in them a number of embryo potato plants, whose lack-luster eyes we see peeping out on all sides. When the time for growth comes, the young plant starts with a reserve-food supply sufficient to keep it growing for some time. We have all noticed, no doubt, how large a plant will grow from a potato, even in a comparatively dark cellar. We must not think that tuber-bearing vines and nut-producing trees are actuated entirely by philanthropic motives. Each nut is the young tree sent forth with his patrimony strapped to his back, ready to make a good start in the world as soon as the favorable time comes.
There are many devices for spending the winter that limits of time and space will prevent me writing about. Many of them more curious than the simple examples I have cited.
Plants are themselves generally unable to move from their fixed positions, so if they are to become prominent in the world they must send out their children—and many and ingenious are their devices for accomplishing this end. Most of my readers are familiar with the parachutes of the silk weed, dandelion and various members of the Compositae family. How they sail through the air. A walk through the autumn forests will make one the unconscious, perhaps unwilling, carrier of numerous Spanish needles, stick tights, burrs and seeds of various plants who have taught their children to steal rides in all sorts of provoking ways. I imagine the wicked old mother laughs as her ugly baby clings to your clothing, sure of a safe ride to a more favorable place for growing. Many plants achieve the same end in a more pleasant way. They produce fruits and berries so luscious that some bird or animal will carry it some distance for the sake of the pulp. Man himself, philanthropist as he is, when he finds that a plant has produced a luscious fruit or palatable seed, will help the distribution and growth, and bring his superior intelligence to the assistance of the plant’s slow instinct to improve its product. A book might be written upon the methods of seed dissemination. In fact, there is a very interesting book upon the subject.
We will just notice briefly the marvelous adaptation of plants to their environment. In the dry plains of Arizona grows a peculiar thick-leaved, stunted, cactus-like plant, suited to withstand the drouth. In the forests of Central South America a great vine climbs to the tops of the tallest trees and there flaunts its gay colors to the breeze. In Damara Land, southwest tropical Africa, upon a small upland section, and nowhere else in the world, grows the marvelous Welwitschia mirabilis, with no real leaves, but with its two cotyledons, persistent and growing to enormous length, living a century and acquiring a great trunk, the flower-stalk growing up from the bare trunk while the two great leaves, if I may so designate them, whip about in the breezes for a century without change, except as they fray out at the ends. These three so dissimilar plants all had a common, not so remote, ancestor, but have grown so unlike in their effort to adapt themselves to their environment, that no casual observer would suspect they were akin.
There is so much to say about the wonderful intelligence displayed by plants in their various activities, that a volume could not do the subject justice. We started with the question, Do plants have instinct? We end with the question, Have they?
Rowland Watts.
Still winter holds the frozen ground and fast the streams with ice are bound,