Such as they are, they maintain a status incomparable with that of non-living things. Incomparable, for instance, as regards the water in which they float. The contrast is startling despite its familiarity. An amœba incarnates a purpose; it embodies a spark of personal existence, unconsciously swaying the forces of inorganic nature towards the ends of its own well-being. The subordination is most real, though profoundly mysterious. In the organic and the inorganic worlds the same laws hold good; the same ultimate atoms exert their preferences in each; in neither is an uncaused effect possible. A bullet can no more be fired from a gun that has no charge than a man can lift a finger without a corresponding outlay of food-products. Accordingly, while plants store and animals expend energy, plants and animals are equally incompetent for its origination. What they can do is to appropriate and specifically apply it; and herein resides the essence of life. 'It would seem,' Sir George Stokes wrote in 1893,[126] 'to be something of the nature of a directing power, not counteracting the action of the physical forces, but guiding them into a determined channel.' What the power is in itself it would be futile to seek to define. We are only sure of its being extra-physical. Matter cannot evolve a principle which disposes of it as its master. Evolution means only the unfolding into self-evidence of something already obscurely present. The 'latent process' (to use a Baconian term) of the hatching of an egg is typical and instructive. Yet it is not the less recondite for being daily conducted before our eyes. A concourse of suns, indeed, fails to impress us with the unutterable wonder of the 'flower in the crannied wall' apostrophized by the last great poet of the nineteenth century.
The two wide kingdoms of life lack a 'scientific frontier.' The boundary-line is ill-marked and irregular. So much so that a few naturalists have set up a neutral zone, or no man's land, inhabited by creatures of mixed or uncertain nature, by plant-animals, or zoophytes in the literal sense of the word. But the expedient avails to shelter ignorance rather than to advance knowledge. For it seems probable that there is no organism so imperfectly characterized as to be genuinely incapable of giving a categorical answer to the question, 'Under which king, Bezonian?' Fungi might, perhaps, on a superficial view, be taken for hybrids. They share the nature of animals so far as to be unable to elaborate their own food, while appearing in other respects to be authentic vegetables. They are, in fact, parasites and scavengers. Not the smallest reason exists for supposing them to constitute a genetic link between the two chief hierarchies. These are, in all likelihood, fundamentally distinct. Only by a gratuitous hypothesis can they be credited with a common ancestor. Each seeks a different kind of perfection; their ideals, so to speak, follow divergent tracks. That the tracks were marked out from the beginning may be safely affirmed; and this implies radical separation. Plants came first, since animals pre-suppose and imperatively require them; the antecedence having quite possibly been by a vast interval of time. On this point, geological evidence, though inconclusive, is suggestive. The Laurentian beds, which are among the very earliest stratified formations, contain no recognisable fossils. They were once supposed to enshrine the remains of a lowly organism dubbed Eozöon Canadense; but the markings that simulated animal forms are now known to be of mineral origin. Laurentian graphite, on the other hand, occurs plentifully; and graphite may be described as coal at a more advanced stage of mineralization. Such deposits, we are led to believe, consist of altered vegetable substances; and it seems to follow that these hoary rocks are the burying ground of a profuse succession of virgin forests. That they flourished beneath the sea—were, in fact, composed of algæ—was the opinion of Professor Prestwich,[127] and it is not easily gainsaid.
Primitive animal life was unquestionably marine, and the Huronian strata, which overlie the Laurentian, afford traces of it in a few sponge-spicules, the cast of an annelid, and such-like scanty leavings. Higher up, the Cambrian series swarms with oceanic invertebrates; fishes, the first type of vertebrates, came upon the scene in Silurian times; and so, by a various and surprising progression, life advanced through the ages, until the ascending sequence culminated with a being cast in a diviner mould, who walks the earth, even now, with face uplifted to the stars.
'Natus homo est; illum mundi melioris origo
Finxit in effigiem moderantûm cuncta deorum.'
In the vegetable kingdom the vital law of development has wrought with less conspicuous effect. The superiority of recent to ancient floras is more significant than striking. A tree-fern or a sigillaria bears comparison with an oak much better than a trilobite or a plesiosaurus with an eagle, horse, or lion. The geological variations of plants, however, have unmistakably tended to make them more serviceable to man—more serviceable to his material needs, and also more gratifying to his æsthetic instincts. For him, flower-petals were painted and perfumes distilled; for him, the grasses of the prairie laid up stores of sustaining nutriment; in preparation for his advent, choice fruits ripened and reddened under Tertiary sunshine; while the barren and sombre vegetation of the Carboniferous epoch had already done its part by dying down into seams of coal for the eventual supply of power for human industry and warmth for human comfort.
It would be an abuse of our readers' patience to discuss the futile conjecture of an extra-terrestrial origin for life on our globe. The agency, in this connection, of germ-laden aerolites was first invoked by Richter of Dresden; and Lord Kelvin gave currency to the notion by an incidental reference to it in 1871 from the Presidential Chair of the British Association. Its adoption would oblige us to regard the denizens of our planet, fauna and flora alike, as salvage from the wreck of some unknown world in space. Credat Judæus Apella. To our minds, the adventures of Baron Munchausen appear more credible than the pre-natal history of the primal organism implied by this 'wild surmise.' Inquiry into the nature of the supposed organism serves to draw closer the web of embarrassment. The remarkable aridity of meteorites excludes the possibility of its having had an aquatic habitat. Members of the fungoid order are unsuited to act as pioneers, owing to their helplessness in the matter of commissariat; and the spores or lichens or mosses could scarcely be expected to survive the vicissitudes of such a journey as they must have performed if meteor-borne to terrestrial shores. The immigration hypothesis, moreover, even if it were plausible, could not be made useful. Difficulties do not vanish on being pushed into a corner; the problem of life is as formidable in one world as in another; we should not expect to find it easier to square the circle in Mars than Deinostratos found it in Greece; matter, we are convinced, has no more psychical initiative in the system of Arcturus than can be ascribed to it in the system of the sun. Profitless conjectures may then be dismissed; they do not help us out of the slough of intellectual impotence.
This need not, indeed, be absolute. The determination to regard things mechanically alone renders them unintelligible. Science becomes unscientific when it refuses to be guided by experience; and we have the plainest testimony of consciousness to the working in ourselves of originative faculties independent of, and irrepressible by, physical agencies. Here we hold the clue to the labyrinth. The intimation conveyed is distinct of a Power outside nature, continually and inscrutably acting for order, elevation, and vivification.
FOOTNOTES:
[119] Hewitt, Problems of the Age, p. 105.
[120] Pasteur, Annales de Chimie et de Physique, tome xliv., p. 6, 1862.