face, that the effective amount of radiation reaching the earth might not have been greater than at present. So it is possible to conceive a uniformitarian state of radiation from the sun, accounting for it by saying that when the sun was hottest and was radiating the most, it was simultaneously raising the greatest amount of obstructions to the propagation of radiations from its surface. A similar argument might, of course, be devised with reference to the greater amount of vapour which increased solar radiation would raise to be condensed in the earth's atmosphere." Hence it is at least not improbable that the photosphere might be partially obscured by non-luminous matter, and that a dense cloudy atmosphere surrounded the earth. In any case, the earth long ago was an incandescent mass, itself as a sun; and only as the earth cooled and darkened would the sun and moon be revealed as rulers of day and night. Plants, as a class, contain little nitrogen, and are dependent on solar rays for their vital activities; but there is, at least, one marked exception. Of a considerable group, the Fungi, many members, if not all, can live and grow in the dark. Moreover, in great depths of the sea unpierced by light, in dark caves, and in many places of gloomy obscurity, there is vegetable life. The light, however, comes from heat; is a transformation of heat from the sun and from the earth. The seed of a plant, buried in the damp earth, grows by the integration of adjacent nutritive materials; the energy effecting this union is, or is by, the undulations caused by warmth of the soil. Diminish the warmth, as in winter, and the seed will not grow. As to the sun's action, the slower undulations, dark waves, not seen, penetrate the soil, set in motion the atoms of the rootlet, and enable them to shake hydrogen atoms out of equilibrium with oxygen atoms. Such is the operation at the root. This helps us to conceive the possibility and reality and nature of the earliest vegetation: rudimentary sporules, with neither radicle nor plumule, possessing some resemblance to imperfect plants that are counted of recent formation. So soon as plants with delicate green stalks tipped with 1 "Recent Advances in Physical Science," p. 174: P. G. Tait, M.A. Plants Preceded Animals. 193 leaflets are to be formed, there must be those rapid waves of the sunbeam, known as light and actinism. These enable the leaflets to decompose the carbonic acid of the atmosphere, by communicating their motor energy to the atoms of chlorophyll, so that they can dislodge adjacent atoms of carbon from the carbonic acid in which they are suspended. Hence, whether viewed popularly or scientifically, we have a great truth: the Energy preparing those germs developed in the earliest manifestations of vegetative force was in operation even when the sun and earth abode in cloudy tabernacles. We can well understand that Moses might have a moral purpose in view, that to check the idolatry of sun-worshippers he would wish to state that life was of God in its origination, not by the sun, before the sun; but that his so-called rough, unscientific account should agree with the latest scientific verity -that life-energy, indeed all energy, is a product and transformation of pre-existent energy-can by no means be owing to his wisdom; it must be attributed to that power which we name "Divine Inspiration." ii. Did plants precede animals? Relics of animals are found in the oldest rocks, with the lowest and earliest known vegetable forms. It is possible, barely probable, that the primal forms of life have been preserved in some primitive fossils. From the layers of crystalline charcoal (graphite), and crystalline limestone (marble), found in the metamorphic rocks, we conclude that vegetable and animal life existed side by side in earlier times. Certainly, animal life did not wait till vegetation was perfected; the lower forms soon appeared, and grew contemporaneously with plants, both advancing till land and sea were replenished. Plants, as a class, exhaling oxygen, and animals, respiring carbonic acid, are necessary to one another; nor can the highest forms of either exist without the presence of both in the earth plants building up themselves with the carbonic acid given out by animals, and animals inspiring the oxygen which plants exhale. The balance of the gases and elements is thus beneficially maintained by the antagonistic compensating actions of the two kingdoms, whose continuous adjustment of internal relations to external relations necessitates N and comprehends all the activities of vegetable and animal life. Finding relics of both in the oldest rocks; that both are needed for the highest forms of either to exist; and that, viewed in their earliest forms, the animal arises as the plant; for, so far as form and substance can be ascertained, they are not separable; the primordial cell of a nettle and the first germ of man being undistinguishable from one another, even by the aid of a powerful microscope, we might conclude that their nature is the same. Nevertheless, they have not the same birth-day, do not live after the same manner, nor upon the same substance. The following twofold fact proves that animals and plants are essentially distinct and wide apart. Plants can form protoplasm,—that is, support themselves by means of inorganic substances; animals cannot. Carbon and oxygen unite to form carbonic acid, hydrogen and oxygen produce water, nitrogen and hydrogen give rise to ammonia. These are all lifeless; on these a plant lives and thrives, but an animal famishes and dies. The animal's highest feat of constructive chemistry is to raise dead protoplasm to a higher form of living protoplasm; but plants form protoplasm of that which is not protoplasm, even from carbonic acid water and ammonia. They, and they alone, build up that matter of life which is the vital substance of the universe. We can hardly think that Moses was accurately acquainted with the discoveries of modern chemical science; nevertheless, he records that plants preceded animals. iii. Were plants of Divine origination? The Power by which matter organises itself, grows into shape, and assumes definite forms in obedience to the definite actions of energy, is a manifestation of that great Unknown whom all phenomena reveal; otherwise, the molecules themselves are creators; and we have no end of little gods. The celebrated Robert Boyle regarded the universe as a machine -a machine may be defined as an organism with life and direction from outside. Thomas Carlyle prefers regarding it as a tree-a tree may be defined as an organism with life and direction within. We, in a degree, may adopt both conceptions, for both imply the interdependence and harmonious Plants of Divine Origination. 195 interaction of parts, and the subordination of organisms to the universal plan. The elements do not spontaneously convert themselves now into iron or wood; now into the oak, or into a giant tree on the shores of the Senegal; now into the delicate petals of an evanescent flower, or into human brain. If the ruling power is not Spirit, all things are material, and there is no ruling Mind; but all things are not material. We have the "imponderables,"-things of old supposed to be matter,— such as heat, light, etc., now known to be but varieties of Energy. These are not matter, but have as real and objective existence as any portion of matter. How is it, moreover, that we, if nothing but material organisms, feel, think, remember, will, and discharge the functions proper to mind? If in us matter has manifestations of mind, why not in the universe at large? It is but strife of words to contend whether the powers be of mind or matter; in either case, organism generates intelligence, or is by intelligence generated. Any way, Intelligence is in the world. This Intelligence, better than all, cannot be the slave or helpless plaything of blind fatality, of something mindless, reasonless, soulless. God is that Intelligence, and from Him the power must proceed; otherwise, brute force is god. We may safely admit the natural agency which science has discovered," All the energy which we derive from plants and animals is drawn from the sun, . . . . the energies which we have been accustomed to call vital. may have a proximately mechanical origin."1 Very well, there is not the least objection to a mechanical formula for what belongs to mechanics. When God said, "Let the earth bring forth," the earth brought forth by its own God-given power; and mechanical power, vital power, moral power, spiritual power, are all emanations of Divine energy. "The reason why the old fable speaks of the spontaneous life of men is, that in those days God Himself was their Shepherd, and ruled over them, just as man, who is by comparison a Divine being, still rules over the animals."2 When God placed sun, moon, and stars in the firmament, to lighten this and other worlds, He endued them with 1 "Vitality:" Professor Tyndall. 2 "Plato's Dialogues. Statesman," p. 271: Dr Jowett's Translation. seasonable and prolific influence. It may be audacious and startling, but not new to say, "We are all children of the sun." "It is of little moment whether we express the phenomena of matter in terms of spirit, or the phenomena of spirit in terms of matter,"1 if we allow that matter is not a brutal and malignant thing, but that good servant of God by whom wonderful works are done, and with which beautiful shapes are wrought. Moses had anticipated scientific theories when he wrote of "precious fruits brought forth by the sun" (Deut. xxxiii. 14); and he warns us against both ancient and modern sun-worshippers by recording the fact that God can and does make these things according to His own will. The scientific hypothesis is that life began in simple primordial organisms. The Bible account in no way contradicts the microscopic statement, but builds up all life from the ground; and the hypothetical monads or protoplasms, or whatever they may ultimately be called, of grass, herb, plant, tree, which were caused to have in themselves the power of reproduction, are as wonderful and complicate in their origination and development as would be the instantaneous appearance of trees already loaded with fruit. Worlds within worlds were contained in those early organisms. They enclosed, potentially, the beauty, power, and life of grass, herb, Milton wrote :— tree. "One first matter all, Endued with various forms, various degrees Proportioned in each kind."-Paradise Lost. Richter conveys a lesson good and true-" I picked up in the choir a faded rose-leaf, that lay under the feet of the boys. Great God! what had I in my hand but a small leaf with a little dust upon it; and upon the small fugitive thing fancy built a whole paradise of joy, a whole summer dwelt upon this leaf. I thought of the beautiful day when the boy 1 66 Physical Basis of Life :" Prof. Huxley. |