In the Darwinian struggle for existence there is first the struggle with environment, or with the nonliving forces--heat, cold, storm, wind, flood; the organic always at war with the inorganic out of which its power comes. The fateful physical and mechanical forces go their way regardless of the life that surrounds them and which draws its en-ergy from them. Gravity would pull down every tree and shrub and every animal that walks or flies. The wind and the storm would flatten down the flowers and grasses and grains like a steam roller, and often succeeds in doing so. See the timothy and wheat and corn struggle to lift themselves again. Behold how the trees grip the rocks and soil, and brace themselves against the wind! This struggle is, of course, not a conscious one. Apart from the origi-nal push of life, it can all be explained in terms of physics and chemistry. The bio-chemist will tell you why the plant leans toward the light, and why it rights itself when pressed down; but why or how matter organizes itself into the various living forms is a question before which natural philosophy is dumb. Neither chemistry nor physics can give us the secret of life. The ingenious devices to secure cross-fertilization among certain plants, devices for scattering the seed among others,--the hooks, the wings, the springs,--to me all seem to imply in-telligence, not apart from, but inherent in, the things themselves. Power of adaptation--to take advantage of wind and flood, of solid and fluid-is one of the mysterious attributes of life. And yet we know that vegetable life takes advantage of these things not, as we do, by forethought and invention, but by a mysterious inherent impulse.
How the bee and the bird battle with the wind, the fish with the waves and the rapids, the fur-bearers with the cold and the snow! how all living creatures struggle to escape or resist the dissolving power of the natural forces!
The ever-present instinct of fear in all wild crea-tures and in children, and the quickness with which it can be aroused in all persons, throw light upon the crueler aspects of this struggle for existence which is common to all forms of animal life. Had life never been beset with perils, we should have been strangers to the emotion of fear, as would all other creatures. Even the fly that alights on my paper as I write fears my hand. It is ever on guard against its natural enemies. This is the proof of the universal struggle. Among the lower forms the struggle or competition of the fleet with the slow, the cunning with the stupid, the sharp-eyed, the sharp-eared, and the keen of scent with those less so; of the miscellaneous feeders with the more specialized feeders; and, among mankind, the com-petition of men of purpose, of foresight, of judgement, of experience, of probity, and of other per-sonal resources, with men who are deficient in these things; and, among nations and peoples, the in. evitable competition of those who cherish the high. est national ideals, the best-organized governments, the best race inheritance, the most natural resources, and so on, with the less fortunate in these respects --all this struggle and competition, I say, is benefi-cent and on the road to progress.
Myriads of different types of animal and vege-table life fit into the scheme of organic nature without conflict or hindrance, but when there is conflict, the strong prevail. The small and the gigantic, the feeble and the mighty, the timid and the bold, the frail and the robust--birds, insects, mice, squirrels, cattle--exist in the same landscape and all prosper. Only when there is rivalry do the feeble go to the wall, which means only that their numbers are kept down. The cats do not exterminate the mice and rats, nor do the hawks and owls exterminate the other birds; they are a natural check on their undue increase. Nature's checks and balances are all important. When species subsist upon species, as weasels upon rodents and hawks upon other birds, there seems to be some law that keeps the bloodthirsty in check. Why should there be so few weasels, since they appear as prolific as their victims? Why so few pigeon hawks, since the hawks have no natural enemies, while the trees swarm with finches and robins?
The conflicting interests in Nature sooner or later adjust themselves; her checks and balances bring about her equilibrium. In vegetation rivalries and antagonisms bring about adaptations. The mosses and the ferns and the tender wood plants grow beneath the oaks and the pines and are favored by the shade and protection which the latter afford them. The farmer's seeding of grass and clover takes better under the shade of the oats than it would upon the naked ground. In Africa some species of flesh-eaters live upon the leavings of larger and stronger species, and in the tropics certain birds become benefactors of the cattle by preying upon the insects that pester them. Fabre tells of certain insect hosts that blindly favor the parasites that destroy them. The scheme has worked itself out that way and Nature is satisfied. Victim or victor, host or parasite, it is all one to her. Life goes on, and all forms of it are hers.