Изображения страниц

organic matter, we are limited to these last alternatives, and can only conceive of it as arising out of matter which was previously inorganic. This assumption, as Haeckel says, is a necessary part of the doctrine of Evolution. The controversy on so-called "spontaneous" generation has been a long one,1 but the question discussed has usually been whether organisms having definite structures, and identifiable as belonging to known genera and species, may not be produced in a few hours in the absence of germs derived from antecedent organisms of the same genera and species. That this should be the case is incredible: not only the established truths of biology, but the established truths of science in general, negative the supposition. In the words of Mr. Spencer, "If there can suddenly be imposed on simple protoplasm the organization which constitutes it a Paramecium, I see no reason why animals of greater complexity, or indeed of any complexity, may not be constituted after the same manner. In brief, I do not accept these alleged facts as exemplifying evolution, because they imply something immensely beyond that which evolution, as I understand it, can achieve." What, then, is the view indicated by evolution with regard to the stages of the change from inorganic matter to organic ?

It is no more needful to suppose an "absolute commencement of organic life," or a "first organism," than it is needful to suppose an absolute commencement of social life and a first social organism. The assumption

1 For the literature of the subject, see Prof. Huxley's Address to the Brit. Assoc., 1870; and the Edin. Review, April 1867. For recent discussion in this country, Mr Bentham's Addres to the Linnean Society, May 1872.



of such a necessity in this last case, made by early speculators with their theories of "social contracts" and the like, is disproved by the facts; and the facts, so far as they are ascertained, disprove the assumption of such a necessity in the first case. That organic matter was not produced all at once, but was reached through steps, we are well warranted in believing by the experiences of chemists. Organic matters are produced in the laboratory by what we may literally call artificial evolution. Chemists find themselves unable to form these complex combinations directly from their elements; but they succeed in forming them indirectly, by successive modifications of simpler combinations. Beginning with some binary compound such as ammonia, which consists of one atom of hydrogen and three of nitrogen, they can, by substituting an atom of methyl for one of the hydrogen atoms, generate a ternary compound called methyl-amine. From this, again, a still more compound substance is reached, and eventually, by modifications upon modifications, very highly complex substances. We can scarcely doubt that in the early world, as in the modern laboratory, simple combinations preceded complex ones, and inferior types of organic substances evolved the superior types, by their mutual actions under fit conditions. The moulding of such organic matter into the simplest types of living things must have commenced with portions of protoplasm more minute, more indefinite, and more inconstant in their characters than the lowest Rhizopods-less distinguishable from a mere fragment of albumen than even the Protogenes of Professor Haeckel. The evolution of specific shapes must, like all other organic evolution, have resulted from the actions and reactions between

such incipient types and their environments, and the continual survival of those which happened to have specialties best fitted to the specialties of their environments. To reach by this process the comparatively well-specialised forms of ordinary Infusoria must have taken an enormous period of time.1

It seems obvious that this view would open the way for some modification of Mr Darwin's theory, in the direction indicated by Mr G. H. Lewes-that organic substance has been evolved at a thousand different points of the globe. But whether by one origin or a thousand, the evolution theory points to the production of organic matter from inorganic by the operation of natural law. And whether the first forms originated at one spot or many, subsequent forms would be evolved through the agency of natural selection.

1 Principles of Biology. Appendix.
2 Fortnightly Review, November 1868.


[ocr errors]


We now have before us an outline of the Theory of the Evolution of Living Things, and it is sufficient to show us that the various forms of life which people the earth owe their existence to natural causes; that species are evolved from species as individuals are born of individuals; and that there is no more reason for saying that God created any existing species than there is for saying that He created the writer or the reader of this essay. On the other hand, there is no less reason for saying so; and every one who has answered the question, "Who made you?" by naming the Deity, may answer in the same way the question, "Who caused the evolution of each species of living things?" It puzzles one to see what difficulty is involved in the one question and answer, which is not found also in the other; yet it seems to be assumed, both by the advocates and the opponents of Evolution, that if natural processes are shown to have produced the results, Divine action is excluded; if we can see the machinery, the machinery has done it all.

Mr Darwin says, "Nothing at first can appear more

1 See Darwin: Origin of Species, p. 492. Wallace: Nat. Sel., p. 268. Lionel Beale: Life Theories, p. 9. Edin. Rev., July 1871, p.


difficult to believe than that the more complex organs and instincts should have been perfected, not by means superior to, though analogous with, human reason, but by the accumulation of innumerable slight variations, each good for the individual possessor." In this passage it is assumed that the accumulation of variations till a new species is formed is a process not analogous to man's processes, but to be contrasted with the latter; yet the experimental argument which lies at the very base of Mr Darwin's theory is, that man's process in forming new breeds of pigeons is the analogue of nature's process in evolving new forms from old-the one is artificial selection, the other natural selection. Mr Darwin's true line, as remarked by Dr Asa Gray, should be that his hypothesis concerns the order and not the cause, the how and not the why, of the phenomena, and so leaves the question of design just where it was before.1

It is shown by evolutionist writers that the human race has had an origin as corporeal and as derivative as that of the individual man; and the existence of every species of animal and plant is the result of causes fitted to produce it the immediate cause being the action of external conditions on organisms not greatly different from the new species, the remote causes being the laws of matter and motion, and the persistence of force or energy in the universe. The effects never come without the natural causes; the causes are equal to the effects; every new result is but à transformation of previously existing energy; the energy cannot be destroyed nor increased in amount, and all its changes of form are

1 Natural Selection not Inconsistent with Natural Theology. By Asa Gray, M.D., p. 38.

« ПредыдущаяПродолжить »