Part 21

Let the reader remark further, the bearing of those facts from which this principle of geological reasoning has been derived, on the development hypothesis. We find species restricted to circles and periods; and though stragglers are occasionally found outside the circle in the existing state of things, never are they found beyond their period among the remains of the past. It was profoundly argued by Cuvier, that _life_ could not possibly have had a chemical origin. “In fact,” we find him remarking, “life exercising upon the elements which at every instant form part of the living body, and upon those which it attracts to it, an action contrary to that which would be produced without it by the usual chemical affinities, it is inconsistent to suppose that it can itself be produced by these affinities.” And the phenomena of restriction to circle and period testify to the same effect. Nothing, on the one hand, can be more various in character and aspect than the organized existences of the various circles and periods; nothing more invariable, on the other, than the results of chemical or electrical experiment. And yet, to use almost the words of Cuvier, “we know of no other power in nature capable of reuniting previously separated molecules,” than the electric and the chemical. To these agents, accordingly, all the assertors of the development hypothesis have had recourse for at least the _origination_ of life. Air, water, earth existing as a saline mucus, and an active persistent electricity, are the creative ingredients of Oken. The author of the “Vestiges” is rather less explicit on the subject: he simply refers to the fact, that the “basis of all vegetable and animal substances consists of nucleated cells,—that is, of cells having granules within them;” and states that globules of a resembling character “can be produced in albumen by electricity;” and that though albumen itself has not yet been produced by artificial means,—the only step in the process of creation which is wanting,—it is yet known to be a chemical composition, the mode of whose production may “be any day discovered in the laboratory.” Further, he adopts, as part of the foundation of his hypothesis, the pseudo-experiment of Mr. Weekes, who holds that out of certain saline preparations, acted upon by electricity, he can produce certain living animalcula of the mite family;—the vital and the organized out of the inorganic and the dead. In all such cases, electricity, or rather, according to Oken, galvanism, is regarded as the vitalizing principle. “_Organism_,” says the German, “is _galvanism_ residing in a thoroughly homogeneous mass.... A galvanic pile pounded into atoms must become alive. In this manner nature brings forth organic bodies.” I have even heard it seriously asked whether electricity be not God! Alas! could such a god, limited in its capacity of action, like those “gods of the plains” in which the old Syrian trusted, have wrought, in the character of Creator, with a variety of result so endless, that in no geologic period has repetition taken place? In all that purports to be experiment on the development side of the question, we see nothing else save repetition. The _Acarus Crossi_ of Mr. Weekes is not a new species, but the _repetition_ of an old one, which has been long known as the _Acarus horridus_, a little bristle-covered creature of the mite family, that harbors in damp corners among the debris of outhouses, and the dust and dirt of neglected workshops and laboratories. Nay, even a change in the chemical portion of the experiment by which he believed the creature to be produced, failed to secure variety. A powerful electric current had been sent, in the first instance, through a solution of silicate of potash, and, after a time, the _Acarus horridus_ crawled out of the fluid. The current was then sent through a solution of nitrate of copper, and after a due space, the _Acarus horridus_ again creeped out. A solution of ferro-cyanate of potash was next subjected to the current, and yet again, and in greater numbers than on the two former occasions, there appeared, as in virtue, it would seem, of its extraordinary appetency, _to be_ the same ever-recurring _Acarus horridus_. How, or in what form, the little creature should have been introduced into the several experiments, it is not the part of those who question their legitimacy to explain; it is enough for us to know, that individuals of the family to which the _Acarus_ belongs are so remarkable for their powers of life, even in their fully developed state, as to resist, for a time, the application of boiling water, and to live long in alcohol. We know, further, that the _germs_ of the lower animals are greatly more tenacious of vitality than the animals themselves; and that they may exist in their state of embryonism in the most unthought of and elusive forms; nay,—as the recent discoveries regarding alterations of generation have conclusively shown,—that the germ which produced the parent may be wholly unlike the germ that produces its offspring, and yet identical with that which produced the parent’s parent. Save on the theory of a quiescent vitality, maintained by seeds for centuries within a few inches of the earth’s surface, we know not how a layer of shell, sand, or marl, spread over the bleak moors of Harris, should produce crops of white clover, where only heath had grown before; nor how brakes of doddered furze burnt down on the slopes of the Cromarty Sutors should be so frequently succeeded by thickets of raspberry. We are not, however to give up the _unknown_,—that illimitable province in which science discovers,—to be a wild region of dream, in which fantasy may invent. There are many dark places in the field of human knowledge which even the researches of ages may fail wholly to enlighten; but no one derives a right from that circumstance to people them with chimeras and phantoms. They belong to the philosophers of the future,—not to the visionaries of the present. But while it is not our part to explain _how_, in the experiments of Mr. Weekes, the chain of life from life has been maintained unbroken, we can most conclusively show, that that world of organized existence of which we ourselves form part, is, and ever has been, a world, not of tame repetition, but of endless variety. It is palpably not a world of _Acaridæ_ of one species, nor yet of creatures developed from these, under those electric or chemical laws of which the grand characteristic is invariability of result. The vast variety of its existences speak not of the operation of _unvarying laws_, that represent, in their uniformity of result, the unchangeableness of the Divinity, but of _creative acts_, that exemplify the infinity of His resources.

Let the reader yet further remark, if he has followed me through these preliminary observations, what is really involved in the hypothesis of the author of the “Vestiges,” regarding the various floras common to the British islands and the Continent. If it was upon his scheme that England, Ireland, and the mainland of Europe came to possess an identical flora, production _de novo_ and by repetition of the same species must have taken place in thousands of instances along the shores of each island and of the mainland. His hypothesis demands that the sea-weed on the coast of Ireland should have been developed, first through lower, and then higher forms, into thousands of terrestrial plants,—that exactly the same process of development from sea-weed into terrestrial plants of the same species should have taken place on the coast of England, and again on the coasts of the Continent generally,—and that identically the same vegetation should have been originated in this way in at least three great centres. And if plants of the same species could have had three distinct centres of organization and development, why not three hundred, or three thousand, or three hundred thousand? Nor will it do to attempt escaping from the difficulty, by alleging that there is the groundwork in the case of at least a common marine vegetation to start from; and that thus, if we have not properly the existence of the direct hereditary tie among the various individuals of each species, we may yet recognize at least a sort of collateral relationship among them, derived from the relationship of their marine ancestry. For relationship, in even the primary stage, the author of the “Vestiges” virtually repudiates, by adopting, as one of the foundations of his hypothesis, with, of course, all the legitimate consequences, the experiments of Mr. Weekes. The animalculæ-making process is instanced as representative of the first stage of being,—that in which dead inorganic matter assumes vitality; and it corresponds, in the zoological branch, to the production of a low marine vegetation in the phytological one. A certain semi-chemical, semi-electrical process, originates, time after time, certain numerous low forms of life, identical in species, but connected by no tie of relationship: such is the presumed result of the Weekes experiment. A certain further process of development matures low forms of life, thus originated, into higher species, also identical, and also wholly unconnected by the family tie: such are the consequences legitimately involved in that island-vegetation theory promulgated by the author of the “Vestiges.” And be it remembered that Mr. Weekes’ process, so far as it is simply electrical and chemical, is a process which is as capable of having been gone through in all times and all places, as that other process of strewing marl upon a moor, through which certain rustic experimenters have held that they produced white clover. It could have been gone through during the Carboniferous or the Silurian period; for all truly chemical and electrical experiments would have resulted in manifestations of the same phenomena then as now:—an acid would have effervesced as freely with an alkali; and each fibre of an electrified feather—had feathers then existed—would have stood out as decidedly apart from all its neighbors. We must therefore hold, if we believe with the author of the “Vestiges,” first, from the Weekes experiment, that in all times, and in all places, every centre of a certain chemical and electric action would have become a new centre of creation to certain _recent_ species of low, but not _very_ low, organization; and, second, from his doctrine regarding the identity of the British and Continental floras, that in the course of subsequent development from these low forms, the process in each of many widely-separated centres,—widely separated both by space and time,—would be so nicely correspondent with the process in all the others, that the same higher _recent_ forms would be matured in all. And to doctrines such as these, the experience of all Geologists, all Phytologists, all Zoologists, is diametrically opposed. If these doctrines be true, _their_ sciences are false in their facts, and idle and unfounded in their principles.

THE TWO FLORAS, MARINE AND TERRESTRIAL. BEARING OF THE EXPERIENCE ARGUMENT.

Is the reader acquainted with the graphic verse, and scarce less graphic prose, in which Crabbe describes the appearances presented by a terrestrial vegetation affected by the waters of the sea? In both passages, as in all his purely descriptive writings, there is a solidity of truthful observation exhibited, which triumphs over their general homeliness of vein.

“On either side Is level fen, a prospect wild and wide, With dykes on either hand, by ocean self-supplied. Far on the right the distant sea is seen, And salt the springs that feed the marsh between; Beneath an ancient bridge the straitened flood Rolls through its sloping banks of slimy mud; Near it a sunken boat resists the tide, That frets and hurries to the opposing side; The rushes sharp, that on the borders grow, Bend their brown florets to the stream below, Impure in all its course, in all its progress slow. Here a grave Flora scarcely deigns to bloom, Nor wears a rosy blush, nor sheds perfume. The few dull flowers that o’er the place are spread, Partake the nature of their fenny bed; Here on its wiry stem, in rigid bloom, Grows the salt lavender, that lacks perfume; Here the dwarf sallows creep, the septfoil harsh, And the soft slimy mallow of the marsh. Low on the ear the distant billows sound, And just in view appears their stony bound.”

“The ditches of a fen so near the ocean,” says the poet, in the note which accompanies this passage, “are lined with irregular patches of a coarse-stained laver; a muddy sediment rests on the horse-tail and other perennial herbs which in part conceal the shallowness of the stream; a fat-leaved, pale-flowering scurvy-grass appears early in the year, and the razor-edged bullrush in the summer and autumn. The fen itself has a dark and saline herbage: there are rushes and _arrow-head_; and in a few patches the flakes of the cotton-grass are seen, but more commonly the _sea-aster_, the dullest of that numerous and hardy genus; a _thrift_, blue in flower, but withering, and remaining withered till the winter scatters it; the _salt-wort_, both simple and shrubby; a few kinds of grass changed by the soil and atmosphere; and low plants of two or three denominations, undistinguished in the general view of scenery;—such is the vegetation of the fen where it is at a small distance from the ocean.”

And such are the descriptions of Crabbe, at once a poet and a botanist. In referring to the blue tint exhibited in salt-fens by the pink-colored flower of the _thrift_, (_Statice Armeria_,) he might have added, that the general green of the terrestrial vegetation likewise assumes, when subjected to those modified marine influences under which plants of the land can continue to live, a decided tinge of blue. It is further noticeable, that the general brown of at least the larger algæ presents, as they creep upwards upon the beach to meet with these, a marked tinge of yellow. The prevailing brown of the one flora approximates towards yellow,—the prevailing green of the other towards blue; and thus, instead of mutually merging into some neutral tint, they assume at their line of meeting directly antagonistic hues.

But what does experience say regarding the transmutative conversion of a marine into a terrestrial vegetation,—that experience on which the sceptic founds so much? As I walked along the green edge of the Lake of Stennis, selvaged by the line of detached weeds with which a recent gale had strewed its shores, and marked that for the first few miles the accumulation consisted of marine algæ, here and there mixed with tufts of stunted reeds or rushes, and that as I receded from the sea it was the algæ that became stunted and dwarfish, and that the reeds, aquatic grasses, and rushes, grown greatly more bulky in the mass, were also more fully developed individually, till at length the marine vegetation altogether disappeared, and the vegetable debris of the shore became purely lacustrine,—I asked myself whether here, if anywhere, a transition flora between lake and sea ought not to be found? For many thousand years ere the tall gray obelisks of Stennis, whose forms I saw this morning reflected in the water, had been torn from the quarry, or laid down in mystic circle on their flat promontories, had this lake admitted the waters of the sea, and been salt in its lower reaches and fresh in its higher. And during this protracted period had its quiet, well-shattered bottom been exposed to no disturbing influences through which the delicate process of transmutation could have been marred or arrested. Here, then, if in any circumstances, ought we to have had in the broad, permanently brackish reaches, at least indications of a vegetation intermediate in its nature between the monocotyledons of the lake and the algæ of the sea; and yet not a vestige of such an intermediate vegetation could I find among the up-piled debris of the mixed floras, marine and lacustrine. The lake possesses no such intermediate vegetation. As the water freshens in its middle reaches, the algæ become dwarfish and ill-developed; one species after another ceases to appear, as the habitat becomes wholly unfavorable to it, until at length we find, instead of the brown, rootless, flowerless fucoids and confervæ of the ocean, the green, rooted, flower-bearing flags, rushes, and aquatic grasses of the fresh water. Many thousands of years have failed to originate a single intermediate plant. And such, tested by a singularly extensive experience, is the general evidence.

There is scarce a chain-length of the shores of Britain and Ireland that has not been a hundred and a hundred times explored by the botanist,—keen to collect and prompt to register every rarity of the vegetable kingdom; but has he ever yet succeeded in transferring to his herbarium a single plant caught in the transition state? Nay, are there any of the laws under which the vegetable kingdom exists better known than those laws which fix certain species of the algæ to certain zones of coast, in which each, according to the overlying depth of water and the nature of the bottom, finds the only habitat in which it can exist? The rough-stemmed tangle (_Laminaria digitata_) can exist no higher on the shore than the low line of ebb during stream-tides; the smooth-stemmed tangle (_Laminaria saccharina_) flourishes along an inner belt, partially uncovered during the ebbs of the larger neaps; the forked and cracker kelp-weeds (_Fucus serratus_ and _Fucus nodosus_) thrive in a zone still less deeply covered by water, and which even the lower neaps expose. And at least one other species of kelp-weed, the _Fucus vesiculosus_, occurs in a zone higher still, though, as it creeps upwards on the rocky beach, it loses its characteristic bladders, and becomes short and narrow of frond. The thick brown tufts of _Fucus canaliculatus_, which in the lower and middle reaches of the Lake of Stennis I found heaped up in great abundance along the shores, also rises high on rocky beaches,—so high in some instances, that during neap-tides it remains uncovered by the water for days together. If, as is not uncommon, there be an escape of land springs along the beach, there may be found, where the fresh water oozes out through the sand and gravel, an upper terminal zone of the confervæ, chiefly of a green color, mixed with the ribbon-like green layer, (_Ulva latissima_,) the purplish-brown layer, (_Porphyra laciniata_,) and still more largely with the green silky Enteromorpha, (_E. compressa_.)[37] And then, decidedly within the line of the storm-beaches of winter,—not unfrequently in low sheltered bays, such as the Bay of Udale or of Nigg, where the ripple of every higher flood washes,—we may find the vegetation of the land—represented by the sentinels and picquets of its outposts—coming down, as if to meet with the higher-growing plants of the sea. In salt marshes the two vegetations may be seen, if I may so express myself, _dovetailed_ together at their edges,—at least one species of club-rush (_Scirpus maritimus_) and the common saltwort and glasswort (_Salsola kali_ and _Salicornia procumbens_) encroaching so far upon the sea as to mingle with a thinly-scattered and sorely-diminished fucus,—that bladderless variety of the _Fucus vesiculosus_ to which I have already referred, and which may be detected in such localities, shooting forth its minute brown fronds from the pebbles. On rocky coasts, where springs of fresh water come trickling down along the fissures of the precipices, the observer may see a variety of _Rhodomenia palmata_—the fresh-water dulse of the Moray Frith—creeping upwards from the lower limits of production, till just where the common gray balanus ceases to grow. And there, short and thick, and of a bleached yellow hue, _it_ ceases also; but one of the commoner marine confervæ,—the _Conferva arcta_, blent with a dwarfed _Enteromorpha_,—commencing a very little below where the dulse ends, and taking its place, clothes over the runnels with its covering of green for several feet higher: in some cases, where it is frequently washed by the upward dash of the waves, it rises above even the flood-line; and in some crevice of the rock beside it, often as low as its upper edge, we may detect stunted tufts of the sea-pink or of the scurvy-grass. But while there is thus a vegetation intermediate _in place_ between the land and the sea, we find, as if it had been selected purposely to confound the transmutation theory, that it is in no degree intermediate in character. For, while it is chiefly marine weeds of the lower division of the confervæ that creep upwards from the sea to meet the vegetation of the land, it is chiefly terrestrial plants of the higher division of the dicotyledons that creep downwards from the land to meet the vegetation of the sea. The salt-worts, the glass-worts, the arenaria, the thrift, and the scurvy-grass, are all dicotyledonous plants. Nature draws a deeply-marked line of division where the requirements of the transmutative hypothesis would demand the nicely graduated softness of a shaded one; and, addressing the strongly marked floras on either hand, even more sternly than the waves themselves, demands that to a certain definite bourne should they come, and no farther.