Page:Popular Science Monthly Volume 11.djvu/696

676 of the sun. However it may have been at one period of the history of the earth, when its internal temperature may have been of a nature to favor the development of organic life without the sun's aid, by the earth becoming itself a sort of sun, it may at least be now affirmed that the solar radiations are the sole condition of vital existence on the globe. This fact is so apparent that even savages have generally recognized it, and science has scarcely been able to qualify the popular conception. By the aid of the sun's heat and light the various forms of vegetable and animal life have been evolved. By the same influence, year by year, the buds, and flowers, and leaves, unfold to the elements, and renew their conditions of growth and reproduction. By means of it the waters of the globe are in part converted into vapor and gas, in which state alone they are adapted to the supply of organic beings. By its influence the various organic bodies on the surface of the earth are finally disintegrated, and the materials for new forms and new beings are dissipated into the gaseous form, for recomposition and reutilization. By the same influence the waters of the globe are prevented from solidifying, and made the abode of millions of organic beings. In a word, it is the influence of the sun which alone renders our planet a habitable globe.

But what is the nature of this great and wonderful influence as expressed in the terms of the redistribution of matter? However paradoxical it may seem, it is nevertheless true that the great life creating and life-sustaining force of the sun is cosmologically a disintegrating force, a force of dissolution. Indeed, the solar and sidereal radiations are the only examples which the whole universe presents to us of such a force. It seems strange enough to be compelled to ascribe all the phenomena which have been embodied in the term organic evolution to the action of a force which is the precise opposite of evolution, and which ultimately accomplishes the dissolution of every such aggregate. Yet it is only because the sun is in a state in which its matter is being integrated, and its motion radiated into space, that our earth is capable of producing the forms of organic life. It is only because a portion of this motion, ejected from the sun, is intercepted and absorbed by the earth, by which a portion of its own matter is disintegrated, and its own course of evolution is in so far arrested that the presence of the beings peopling it has been made possible. It is only through cosmical dissolution that organic evolution can go on.

Is life, then, a process of dissolution? Is organic evolution a misnomer? Are the unfolding of the bud, the branching of the tree, the hatching of the egg, the differentiation of the animal—are these but so many steps which concentrated matter is taking toward its final disintegration? Is development the antithesis of evolution? To all these questions a negative answer may, I think, be given. But we have gone far enough to perceive that some broad distinction exists between