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13. Incalculable periods. For, as the first factor in Mr. Darwin's scheme is War, so the second is Time. And certainly he is entitled to draw freely on the past. The sedimentary strata of Great Britain are nearly fourteen miles thick--Palæozoic = 10 miles, Secondary = 3
miles, Tertiary = 1 mile--and a typical diagram allowing for blanks and full development elsewhere, as in the Permian and later systems, of what is poorly represented in this island, would require for the whole series a scale enlarged by perhaps one-third. Now, what is a stratum ? It is the spoil won by the sea from the dry land. Mark how ceaselessly the ocean lays siege to the shore; how indefatigably every winter the batteringram of the billows smites on the coast-wall, and grinds it down. Every particle so torn away, or in gentler fashion gnawed away, helps to make a stratum. But this smiting and gnawing of the margin is as nothing to the atmospheric and aqueous abrasion of the surface. A stratum is substantially the strewing of what is swept off the land by rains and rivers on and over the floor of the deep; the tribute of the ocean of air to the ocean of water, of the waters that be above the firmament to the waters below. Here then is a great natural chronometer; the ocean is an hour-glass whose slowly precipitating and accumulating sand-drops tell off and register the life-periods of the earth. But to read that register other than roughly and approximately is beyond the best skill of man. The rates of deposition in ocean deltas, from which our data must be derived, vary with the volume and the rapidity of rivers, and the nature of the basins they drain. Then, again, the rate of deposition may have varied as widely at different epochs as it does in different regions. A high temperature with a moisture-loaded atmosphere, such as evidently prevailed in the Silurian period, supposes a strong impulse to the denuding agencies; and the process would be accelerated in proportion as the denuded surfaces were, as they are believed to have been, yielding and friable. On the other hand, the phenomena of organic remains are often such as yield the clearest proof of extreme slowness of accumulation. 11
As a fair gauge of average rates of deposition, consistent with these phenomena, we may take the calculated growth of sediment in the Bay of Bengal, which is about an inch in a century. Such the stratum-making power of the Ganges, less indeed than that of the Nile, but far greater than that of the Rhine ; 1: and it measures off the age of the oldest water-woven rocks as approaching, at the least, one hundred millions of years. Observe, of the sedimentary rocks; not of the globe, nor of life. The globe is indefinitely older; life,
; as we shall see by and by, according to our present evidence, is relatively much more recent. Still, even on this estimate, and with this deduction, that is an aweinspiring vista which stretches upward to the dawnings of vitality on the earth. Any man who is nearing or passing the threescore - and - ten may form this rough reckoning to his own mind—that, for every year he has been alive, Life has lived at least a million. Suppose every human being in this populous city endowed with a life-lease of one thousand years, and each of these to be pieced on in succession to one another, this would no more than cover, if cover it did, the sweep of palæontological time. Or take the distance of the sun from the earth as miles, and thrust that into the stratified depths as years, you will let fall a plummet that will scarcely outfathom, if it even traverse, the abyss of that solemn antiquity.13 Mr. Darwin, therefore, has ample scope for all reasonable demands on the lapse of terrestrial time. To be sure, when he exacts three hundred millions of years for a process which might, according to the observed rates of sea-encroachment on a tolerably impressible coast-line, be more feasibly restricted to three, 14 he
is betraying the bias bred by devotion to a favourite hypothesis. But it is needless to debate these figures. A myriad years or a million are much the same in an argument of this kind. The farther back, indeed, we carry the genesis of life, the more morally significant, by contrast, becomes the historic period, and the age of
Even Mr. Darwin's enormous drafts will not break the bank of eternity.
14. Such the hypothesis. And doubtless Mr. Darwin has the signal merit of portraying, with a freshness and force altogether his own, what no preceding naturalist had seized with a like grasp---the important part played in the animal world by the constant competition for subsistence. Our author is the Malthus of Natural History. But it is one thing to discern the influential character of the struggle, and another to interpret its office or to decipher its results. Mr. Darwin insists that the struggle tends to change of the type, indefinite alteration of it for the better. Yet another reading, and an older, of the war of nature, is quite as likely to be true. What if animals were made from the first as “good” as they were ever meant to be; under no necessity of becoming better, though sometimes in danger of becoming worse? In that case the use of the struggle would
be preventive rather than promotive. Its function would be to conserve the type ; to recruit and re-invigorate the primordial form ; and to maintain unimpaired the relative perfection with which that form was gifted by the moulding hand of the Creator. That this, and not its rival, is the true account of the matter, we may speedily be satisfied, if, suspending our guesses, we simply use our eyes. Struggle, everywhere in nature, means death to the sickly, the ricketty, and the feeble; and life to the healthy, the well-knit, and the strong. But precisely as these latter are preserved, a guarantee for purity of type is preserved along with them. The physical beauty and strength of certain South American and Polynesian tribes struck all our early voyagers : the reason was that none but the pick of their offspring survived the hardships of infancy. But these men were not progressing, in virtue of this ordeal, towards a superhuman estate: their perfectness consisted in conformity to the type, and not in transcending it. The struggle exists as guardian of the standard, and the severer the struggle the more typical the type. Through all her domains, Nature weeds out the weak.
Be it so.
A strong buffalo, on that very account, will have worthy heirs to his strength, and a fierce feline carnivore to its daring and ferocity. “Natural