differences are due to this one cause, but, on the contrary, we are justified in assuming a deeper principle which may be thus formulated: All the complex organisms are evolved from organisms less complex, as these were evolved from simpler forms: the link which unites all organisms is not always the common bond of heritage, but the uniformity of organic laws acting under uniform conditions. It is therefore consistent with the hypothesis of Evolution to admit a variety of origins or starting points." In this paper Mr. Lewes distinctly postulates the probability of a repetition of the process of Archebiosis, wherever the conditions were favourable, and though he says nothing against the continuance of such a process in the present day, neither does he dwell upon it as a probability.

Professor Huxley's* opinions on the subject of Archebiosis are very similar to those of Mr. Spencer, with the exception that he seems more strongly opposed to the notion of its occurrence at the present day, and it is to this aspect of the question that I would now direct the reader's attention. Why should men of such acknowledged eminence in matters of Philosophy and Science as Mr. Herbert Spencer and Professor Huxley promulgate a notion which seems

*

Inaugural Address at Meeting of British Association, Nature, Sept. 15, 1870, p. 404.

to involve an arbitrary infringement of the Uniformity of Nature?

They would both have us believe that living matter came into being by the operation of natural causesthat is, by the unhindered play of natural affinities operating in and upon matter which had already acquired a certain degree of molecular complexity. They believe that the simpler kinds of mineral and crystalline matter continue to come into being now as they have ever done; nay, more, they believe that the higher kind of matter, originally initiated by the operation of natural causes, continues to 'grow' both in animal and in vegetal forms, solely under similar influences, and yet they consider themselves justified in supposing that natural causes are now no longer able independently to initiate this living matter or protoplasm. Again, we find Professor Tyndall* also affirming, in the most unhesitating language, the ultimate similarity between crystalline and living matter: affirming that all the various structures by which the two kinds of matter may be represented are equally the "results of the free play of the forces of the atoms and molecules " entering into their composition. And yet he, too, would have us believe that whilst differences in degree of molecular complexity alone separate living from not-living Fragments of Science, 4th edit. (1872), pp. 85-87, and 113-119.

*

matter, the physical agencies which freely occasion the growth of living matter are now incapable of causing its origination.

Why, we may fairly ask, should a supposed difference be erected by Evolutionists between Origination and Growth in the case of living matter, whilst no one dreams of making any such distinction in reference to crystalline matter? Is it true that the process of growth differs from the process of origination, and, if so, in what respects? Philosophically speaking there is little difference. Take the case of the formation of the "silver tree" cited by Professor Tyndall. A weak galvanic current is passed through a solution of nitrate of silver, and simultaneously in a first increment of time a number of molecules of oxygen and of silver begin to aggregate independently into crystals of oxide of silver; in a second increment of time the operation of the same causes produces similar results, only now part of the new crystalline matter forms in connection with the existing recentlyformed germs of crystals, though part of it may still aggregate independently. During a third, a fourth, and all succeeding increments of time in which the same causes operate amidst similar conditions, similar results must ensue. But, taking the process of origination that occurs in the first increment of time,

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would Professor Tyndall have us believe that it is in any essential way different from that process of growth which may take place in a second, third, or fourth increment of time? Does not the very fact that origination and growth so often occur simultaneously in the case of crystalline matter, and under the influence of the same causes, show us that the two processes are intrinsically similar, and that conditions favourable for growth are also likely to be favourable for origination? And if this be true for crystalline matter, may we not infer that it would also be true for living matter? These are questions neither asked nor answered in any definite manner by those whose opinions I have already cited. They are, however, questions by no means unworthy of an attentive consideration.

Although, as a general rule, conditions favourable for the growth of any particular kind of crystalline matter are likely to be favourable for its origination, still it must be acknowledged that the presence of a crystal will occasionally lead to its growth in a medium in which similar crystalline matter had previously shown no tendency to form independently -even in cases where the introduction of a noncrystalline nucleus would not be able to determine a similar formation of crystalline matter. Notwithstanding the general law, therefore, that conditions

favourable for the growth are also favourable for the origination of crystalline matter, we are compelled to admit that growth may be determined under certain conditions where origination does not occur, and that the presence of pre-existing crystalline matter favours the process. And a distinction of the same kind undoubtedly obtains in the case of living matter. We know quite positively that although Bacteria will not originate in a previouslyboiled ammonic tartrate solution, or 'Pasteur's solution,' that the addition of a few of these organisms (all other conditions remaining the same) to either one of the solutions will soon occasion a very considerable growth of the living matter of which Bacteria are composed.* We are thus reduced to ask, whether the influence of the pre-existing nucleus is relatively more potent or more necessary in the case of living matter than it is in the case of crystalline matter? And this is a question which unfortunately we are unable definitely to answer : such minute quantitative and qualitative distinctions cannot be made. But so long as we have no positive knowledge on this subject, we surely have little right to infer that processes both of origination and of growth continue in the case of crystalline matter, and that the process of growth alone survives in the The Beginnings of Life, vol. i. p. 325.

*