There are before the Scientific jury to-day two very vivid questions.

(1) Can modifications in the structure of an individual organism, occurring as a result of its experience, be transmitted?

(2) What is the cause of variation?

If, as Weismann taught, the answer to No. 1 is in the negative, there is little use here in trying to answer No. 2, for from the present point of view the two stand or fall together in the study of Initiative in Evolution. Such distributional answers to No. 2 as Bateson and de Vries may offer do not concern my purpose.

If No. 1 be answered in the affirmative it is sufficient for the purpose of treating initial variations from the Lamarckian standpoint, for it is hardly conceivable that Nature would neglect so simple and obvious a method of leading upwards and onwards the organisms that inhabit a changing world.

It is very clear from what is written on the subject of evolution to-day that a point d’appui in the process is earnestly desired by many workers and that Weismann’s dogma stops the way. A very significant and important remark is made by Professor W. McDougall in his small book on Physiological Psychology, with reference to the inheritance of acquired characters, that it is a “proposi­tion which most biologists at the present time are inclined to deny because they cannot conceive how such transmission can be effected. Nevertheless the rejection of this view leaves us with insuperable difficulties when we attempt to account for the evolution of the nervous system, and there are no established facts with which it is incompatible.”[31] I am aware that in the scheme of observed nature there is evidence of no iron necessity, that the convenience of psychologists should be provided for, and they, like others of us, have to do the best they can with the tools and the materials which exist, and I agree with Professor Thomson in his remark on Misunderstanding No. 1, “that our first business is to find out the facts of the case, careless whether it makes our interpreta­tion of the history of life more or less difficult,”[32] but I am persuaded that he will not treat lightly such a statement, from such a source, on such a subject as that I have quoted from Professor McDougall. As to his second statement on the same page “that in the supply of terminal variations, whose transmissibility is unquestioned, there is ample raw material for evolution” it is important as an opinion, and no more, and there is in the present connec­tion, an elusiveness about it which prevents one allowing it to pass. It should be noted that stress is laid upon the term “variations” and from the context this means congenital full-blown “characters” such as those that Weismann says are provided in the germ guided by selection. At any rate, initial modifications are not signified by Professor Thomson’s remark. So for evolution of forms of life it is possible the assertion may be true, but apart from distribu­tion of variations, under the process called amphimixis, some starting point is required for the initial and wholly useless stages of many variations. These may or may not become “characters” or adaptive.

What the Problems are not.

The ground may be cleared here by saying what our problems are not. There is no question as to whether Lamarckism or Darwinism represents the predominant partner in the story of life; there is no question of the “relative importance of natural selection and the Lamarckian factors in organic evolution,” though such a question may arise when once Lamarckism has received its passport from the authorities; but the time is not yet. Nor is it a question as to the reason why adaptive modifications are so constantly present in the germ. It is not a question of Nature or Nurture, but perhaps may be found to be a study of Nature and Nurture. It is not a question of Mendelian analysis, nor as to the distribu­tion of either mutations on the one hand, nor of minute fluctuating variations on the other. The problems are therefore limited in scope and ambition, and are none the worse for that, as being better open to correc­tion or support.

The Problems Considered.

It seems but natural to most persons who contemplate with any care the ever-changing and progressive drama of life in plants and animals that unquestionably the dramatis personæ by their individual response to the environments and exercise of their functions must contribute a share, however small, to their offspring. When first this view presents itself to their minds they resent as “unnatural” any other possibility. But, alas! they find that such a conclusion is not permitted in those regions where alone the white light of science shines. Here the writ of a priori does not run. The spirit of inquiry makes its challenge to every presupposi­tion and every assertion in its province—even those of current science. I have shown that this particular assump­tion of the natural man was firmly challenged by Weismann, who was not the first, but the greatest, biologist to teach that modifications are not transmitted. Accordingly, agreeable and convenient as it would be to assume the Lamarckian hypothesis as a working one, it needs in the present day to be supported by evidence before this can be allowed. Facts, then, against Weismann’s dogma are demanded and of such a kind as will satisfy so powerful an advocate of his own views. In passing it may be remarked again that there is nothing so misleading as facts, except statistics, and for both sides to bear in mind the warning of a French writer that in such inquiries as this we should be careful lest we find the facts for which we are looking.