Here the distinction between different genera and species, and the provision that was made for the perpetuation of different races, are prominently presented; while the production, in the first instance, not of an "infusorial point" or "microscopic monad," but of a living organism capable of multiplying its kind, is expressly declared; and every race is traced up to that primary organism, in perfect consistency with the only law, whether of vegetable or animal reproduction, which is known to be in operation at the present day. And this law of reproduction, so far from being exclusive of a primary act of Creation, seems to presuppose and require it; for there must be a living organism before there can be vital transmission. But the theory of Physiological Development proceeds on a totally different supposition,—a supposition for the truth of which we have not only no historical evidence, but not even the slightest analogical presumption, since we have no instance of development anywhere except from a germ or seed, produced by an organism preëxisting in a state of maturity.
But the exigencies of that theory demand a wide departure from all the familiar lessons of experience; and hence recourse has been had to a series of the wildest and most extravagant conjectures, such as may well justify the opinion of those who have held that the creed of certain philosophers makes a much larger demand on human credulity than that of almost any section of the Christian Church. For, according to that theory, the origin of the Flora is first accounted for by the action of some element—probably electricity—on a certain mucus, which is supposed to be generated at those points where the ocean comes into contact with the earth and air; that is, on the shore of the sea at low water mark. Maillet had broached the idea of the marine origin of all our present "herbs, plants, roots, and grains,"[39] at a period when the Universal Ocean, of which Leibnitz said so much, was still the creed of some speculative minds; but it has been more recently revived, and exhibited in greater detail, though not with stronger evidence, by some writers of our own age. Thus Dr. Oken tells us that "all life is from the sea;" that "when the sea organism, by self-elevation, succeeds in attaining into form, there issues forth from it a higher organism;" and that "the first organic forms, whether plants or animals, emerged from the shallow parts of the sea." And so the author of "The Vestiges" attempts to show that new races, both of plants and animals, marine and terrestrial, may be accounted for, without any act of immediate creation, by a change or transmutation of species resulting from the agency of natural causes. "There is," as he tells us, "another set of phenomena presented in the course of our history; the coming into existence, namely, of a long suite of living things, vegetable and animal, terminating in the families which we still see occupying the surface. The question arises,—In what manner has this set of phenomena originated? Can we touch at, and rest for a moment on, the possibility of plants and animals having likewise been produced in the way of Natural Law, thus assigning but one class of causes for everything revealed to our sensual observation? Or are we at once to reject this idea, and remain content either to suppose that creative power here acted in a different way, or to believe, unexaminingly, that the inquiry is one beyond our powers?"[40] In reply to these questions, he proceeds to show that "there is a balance of probability from actual evidence in favor of an organic creation by law," and that "in tracing the actual history of organic beings upon the earth," as revealed by Geology, we find that "these came not at once, as they might have been expected to do if produced by some special act, or even some special interposition of will, on the part of the Deity; they came in a long-continued succession, in the order, as we shall afterwards see more convincingly, of progressive organization, grade following grade, till, from an humble starting-point in both kingdoms, the highest forms were realized." Such is his general principle; and, without entering into the details, we may sum up his general argument by saying, in the words of another,[41] that, according to his theory, "dulse and hen-ware became, through a very wonderful metamorphosis, cabbage and spinach; that kelp-weed and tangle bourgeoned into oaks and willows; and that slack, rope-weed, and green-raw, shot up into mangel-wurzel, rye-grass, and clover." So much for the Flora; and now for the Fauna, and the transition from the one to the other. His views are thus exhibited by Sir David Brewster: "The electric spark, escaping from the wild elements around it, struck life into an elementary and reproductive germ, and sea-plants, the food of animals, first decked the rude pavement of the ocean. The lichen and the moss reared their tiny fronds on the first rocks that emerged from the deep; land-plants, evolving the various forms of fruit and flower, next arose,—the Upas and the bread-fruit tree, the gnarled oak and the lofty cedar. Animal life appeared when the granary of nature was ready with its supplies. A globule, having a new globule forming within itself, which is the fundamental form of organic being, may be produced in albumen by electricity; and as such globules may be identical with living and reproductive cells, we have the earliest germ of organic life, the first cause of all the species of animated nature which people the earth, the ocean, and the air. Born of electricity and albumen, the simple monad is the first living atom; the microscopic animalcules, the snail, the worm, the reptile, the fish, the bird, and the quadruped, all spring from its invisible loins. The human similitude at last appears in the character of the monkey; the monkey rises into the baboon, the baboon is exalted to the ourang-outang, and the chimpanzee, with a more human toe and shorter arms, gives birth to man."[42]
The remarks which were offered, in the previous section, on Cosmical Development, are equally applicable, mutatis mutandis, to this other form of the doctrine of Creation by Natural Law. It might be shown, with reference to the supposed generation of plants and animals, just as it was then shown with reference to the generation of planets and astral systems, first, that the theory rests upon a mere hypothesis, which is utterly unsupported by experimental evidence; secondly, that the progress of science has hitherto afforded no ground to believe that the transmutation of species is provided for under the established constitution of nature; and, thirdly, that even were the theory admitted, it would not destroy the evidence of Theism, any more than the propagation of plants and animals under the existing system, which, so far from excluding or impairing, serves rather to enhance and illustrate the proof of creative wisdom and power. In support of this last position, we might adduce the testimony of the author of "The Vestiges" himself; for, referring to the idea that "to presume a creation of living beings by the intervention of law" is equivalent to "superseding the whole doctrine of the Divine authorship of organic nature," he takes occasion to say, "Were this true, it would form a most important objection to the Law theory; but I think it is not only not true, but the reverse of the truth. As formerly stated, the whole idea of law relates only to the mode in which the Deity is pleased to manifest His power in the natural world. It leaves the absolute fact of His authorship of and supremacy over Nature precisely where it was." He adds, in the words of Dr. Buckland, "Such an aboriginal constitution, so far from superseding an Intelligent Agent, would only exalt our conceptions of the consummate skill and power that could comprehend such an infinity of future uses under future systems, in the original groundwork of His Creation."[43]
But, without enlarging on those general considerations which were formerly stated, and which admit of an easy and obvious application to this second form of the theory, we shall offer a few remarks bearing directly on its distinctive peculiarities, and directed to the exposure of its radical defects.
The theory rests on two very precarious foundations: the assumption of spontaneous generation, on the one hand, and the assumption of a transmutation of species on the other. Each of these assumptions is necessarily involved in any attempt to account for the origin of the vegetable and animal races by natural law, without direct Divine interposition. For if, after the first organism was brought into being, the production of every subsequent type may be accounted for simply by a transmutation of species, yet the production of the original organism itself, or the first commencement of life in any form, must necessarily be ascribed either to a creative act or to spontaneous generation. A new product is supposed to have come into being, differing from any that ever existed before it, in the possession of vital and reproductive powers; and this product can only be ascribed, if Creation be denied, to the spontaneous action of some element, such as Electricity, on mucus or albumen. In this sense the doctrine of spontaneous generation seems to be necessarily involved in the first step of the process of Development, and is, indeed, indispensable, if any account is to be given of the origin of vegetable and animal life; but in the subsequent steps of the same process it is superseded by a supposed transmutation of species, whereby a lower form of life is said to rise into a higher, and an inferior passes into a more perfect organism.
But we have no experience either of spontaneous generation on the one hand, or of a transmutation of species on the other. Observation has not discovered, nor has history recorded, an authentic example of either. In regard to the first, the author of "The Vestiges" anticipates this objection, and attempts to answer it. The objection is, that "a transition from the inorganic to the organic, such as we must suppose to have taken place in the early geological ages, is no ordinary cognizable fact of the present time upon earth; structure, form, life, are never seen to be imparted to the insensate elements; the production of the humblest plant or animalcule, otherwise than as a repetition of some parental form, is not one of the possibilities of science."[44] Such is the objection; and how does he attempt to answer it? He endeavors to show, first, that the work of creation having been for the most part accomplished thousands of years ago, we have no reason to expect that the origination of life and species should be conspicuously exemplified in the present day; secondly, that the comparative infrequency, or even the entire absence, of such phenomena now would be no valid reason for believing that they have never been exhibited heretofore, if, on other grounds, the doctrine of 'natural creation' or 'life-creating laws' can be rendered probable; and, thirdly, that even in our own times there ARE facts which seem to indicate the reality, or at least the possibility, of "the primitive imparting of life and form to inorganic elements."[45]
Now, to this elaborate argument in favor of spontaneous generation, or the production of life by natural law, we answer, in the first place, that the mere fact of its being adduced in connection with the Theory of Development affords a conclusive proof that it is indispensable to the maintenance of that theory, that the hypothesis would be incomplete without it, and that no account can be given of creation by the mere doctrine of a transmutation of species. It is the more necessary to make this remark, because not a few who embrace the latter doctrine affect to disown the former, and seek to keep it out of view. But the one is as necessary as the other to a complete theory of Natural Development. The author of "The Vestiges" felt this, and virtually acknowledges it when he undertakes the task of vindicating the credibility of spontaneous generation. But we answer, in the second place, that the method in which he performs his self-imposed task is singularly curious, and not a little instructive. He had, it must be owned, a difficult game to play. The general theory of "The Vestiges" is founded on the fact that, in the ordinary course of Nature, the races of plants and animals are perpetuated by propagation, according to established Natural Laws,—a fact which might seem to afford a strong analogical argument in favor of the supposition that the same order of Nature is maintained also in the few apparently exceptional cases in which, from our defective knowledge, we are unable to trace the connection between the parent and the product. And yet the author evinces no little anxiety to make out a case in favor of "a non-generative origin of life even at the present day;" and he appeals to a class of facts, confessedly obscure, which have not been, as he thinks, satisfactorily accounted for by the law which usually regulates the production of organic beings. He refers us to the speculations of Dr. Allen Thomson on the primitive production of Infusoria,[46] to the facts which modern science, aided by the microscope, has discovered respecting the Entozoa, or the creatures which live within the bodies of others, and, above all, to the experiments of Mr. Crosse and Mr. Weekes, which seemed to result in the production of a small species of insect (Acarus Crossii) from the action of a voltaic battery on a saturated solution of the silicate of potash, or the nitrate of copper, or the ferrocyanate of potassium. The reason of his anxiety to avail himself of these cases is evident. The exigencies of his theory demanded a method of accounting for the primary origin of life different from any that can be found in the common process of propagation. He saw clearly enough that his main argument, founded, as it was, on the law of hereditary transmission, could not account for the production of the first organism; and that, if he would avoid either the doctrine of Immediate Creation, which is so offensive to him, or the idea of Eternal Generation, which is utterly excluded by the clearest lessons of Fossil Geology, he must have recourse to the hypothesis of Spontaneous Generation. Hence he attempts to account for the commencement of new species both of plants and animals, in the course of the world's history, by a transmutation of species; while, for the origin of the first species, he has recourse to the same law of Development, but acting in widely different circumstances, and giving rise to what he calls "aboriginal generation," whereby the inorganic passes into the organic, and life, form, and structure, are imparted to hitherto inert materials by the action of Electricity on mucus or albumen. To accomplish this twofold purpose, he felt it necessary to insist, in the first instance, on the ordinary law of generation as the established order of mediate creation; while he found it equally necessary, in the second place, to insist on those apparently exceptional cases in which the connection between the germ and the product has hitherto eluded philosophical research,—and this for the purpose of showing that the original production of plants and animals was not similar to the ordinary method of their propagation in any other respect than this, that in both cases the result is brought about by Natural Laws, without the direct interposition of any supernatural cause.
Now, in so far as his argument is founded on the principle of analogy,—and it is on this principle that it proceeds throughout,—we submit that it is radically vicious, and utterly inconclusive. For the vast majority of cases in which the commencement of life and organization falls under our notice being confessedly those, not of primary production, but of mediate reproduction, it is reasonable to believe that the same law governs all cases alike, whether we have been able or not to trace the origin of life to the principle of propagation, the few apparent exceptions being sufficiently accounted for by our imperfect knowledge of the causes and conditions on which they depend. Besides, the argument from analogy in favor of a primary production of life by natural causes, in so far as it is founded on the present law of hereditary transmission, is radically defective, since the two cases are widely different; the one presupposing a primary organism of the same kind, from which others are evolved by a law of natural succession, the other exhibiting life as a new product, resulting not from any prior organism, but from the action of causes of a totally different kind, which are not known to be capable of giving birth either to vegetable or animal organisms under the actual constitution of Nature.
But suppose, even, that the Acarus Crossii were admitted to be a real product of Galvanic action on the silicate of potash, and an undeniable instance of "a non-generative origin of life," how would the illustrative example accord with the author's general theory? It might afford a specimen of aboriginal production; but how would it fit in with his favorite doctrine of a gradual and progressive advancement from the lower to the higher forms of organization? The Acarus, at first supposed to be a new and hitherto unknown creature, is now acknowledged to be one of a very familiar species,—a species which may have deposited its ova, and propagated its kind, since the commencement of the present order of things, and whose eggs might very well resist the action even of nitrate of copper, since the creature itself could live in that poisonous mixture. Moreover, it belongs, in point of organization, to one of the highest orders of organisms; not to the radiata, not to the mollusca, but to the highest type of the articulata, the nearest to the vertebrata. Had it been a monad,—a mere living cell,—which Galvanism evolved from the solution, and had this primary product developed itself afterwards in various forms, according to the ascending scale of a progressively improving organization, it might have accorded admirably with the twofold doctrine of spontaneous generation and transmutation of species; but, unfortunately, the first process is so perfect, in the present instance, as to leave little room for the second, and we are almost tempted to hope that perhaps the clumsy and troublesome expedient of a transmutation of species may yet be superseded by the discovery of some method,—we know not what,—whereby not only the articulata, but the vertebrata, and even Man himself, may be immediately produced by some new combination of Nature's elemental laws![47]
We have given prominence, in the first instance, to the doctrine of "spontaneous" or "aboriginal" production, because it constitutes an indispensable part of the Theory of Development, and because we believe that, were this clearly understood, that theory would soon sink into general discredit or total oblivion, like the kindred speculations of Anaximander and Anaxagoras, of the old Ionic School. The experiments of Ehrenberg, instituted with the view of testing the doctrine of spontaneous generation, may be said to have decided the whole question. They did not succeed, indeed, in explaining every apparently exceptional case, for some of the facts are still obscure, and will probably continue to be so, notwithstanding every extension of microscopic power, just as, in the analogous case of the Nebulæ, the increase of telescopic power has enabled us to resolve not a few of them into clusters of stars, while it has served to bring others yet unresolved within the range of our vision. But they were sufficient, at least, to show that, as far as our clear knowledge extends, the one uniform law, "Omne vivum ex ovo," universally prevails, and that the whole analogy of Nature, in so far as its constitution has been ascertained, is adverse to the doctrine of spontaneous generation. Ehrenberg detected the minute germs of vegetable mould, and the ova of some of the smallest animalcules; and when it is considered that these germs and ova are so tenacious of vitality that certain prolific seeds have come down to us from the age of the Pharaohs in the wrappings of the Egyptian mummies,—that they are widely diffused in the air and the waters, insomuch that no sooner does a coral reef appear above the level of the sea than it is forthwith covered with herbage by means of seeds wafted by the winds or deposited by the waves,—and that it is almost impossible to exclude them by any artificial expedient, since they are capable of resisting the action of boiling water and even of alcohol itself,—it cannot, we think, be denied that the few cases which still remain obscure or unexplained may be, at least, probably accounted for in accordance with the same natural law which is found to be invariably established in every department to which our clear knowledge extends.