I.—CREATIVE EVOLUTION.
THOSE who have read Erewhon and The Way of All • Flesh will have been struck by the frequency Of the biological references they contain. Nor are these references accidental. Samiiel Butler was not a novelist, but a biologist who wrote occasional satire to amuse himself and to satisfy his spleen, a fact which the wide popularity of his fictional 'Works has Caused to be over- looked. His biological theories, ignored by contemporary scientists and for a dozen years after his death referred to in terms of contemptuous ridicule by the few biologists who condescended to notice him, have recently been vin- dicated by a number of experiments, the revolutionaiy bearing of which upon our conception of the universe only continues to escape general notice because of the average scientist's constitutional inability to 'use his imagination to grasp the implication of his facts. Since this evidence settles Once and for all the time- worn controversy between the advocates of heredity and environment as the factors chiefly determining character, or, 'more precisely, since it finally determines the respects in which this controversy never can be settled, it deserves the attention of that great body of scientists who although they have never entered' 'a laboratory iii their lives, are justified of thattiile by their inextinguishable curiosity • about' the universe and the way it works ; "in other :words of most men 'and 'some Women. I propose, therefore, to try in the first place to sum- marize Samuel Butler's theory, and to indicate some of the reasons for its forty years of disrepute. In a following article I shall describe the nature of the evidence which has so triumphantly vindicated what was in Butler no more than an inspired guess.
The controversy to which the discovery of evolution gave rise turned upon the causes of variations in species. That such variations had occurred and continued to occur was obvious. If they had not, if, in other words, all offspring exactly resembled their parents, the world would still be peopled by amoebas and jellyfish. There were two contemporary explanations in the field ; that of Darwin and that of Lamarck. Darwin's was no explanation at all. He said, in effect, that he could not tell why variations occurred ; all that he could affirm was that those which were suited to their environment survived. Lamarck ascribed to the influence of external environment what Darwin left to chance. The environ- ment changed, and the species either adapted itself to the change, or it did not ; if it did, it survived, if not, it perished. Darwinism was the orthodox view when in the eighteen-sixties Butler first took the field as a convinced Lamarckian. He contended for purpose and progress in evolution, affirming that the adaptation of the organism to its environment was spontaneous, springing from within, rather than automatic and deter- mined by influences exerted from without. More than this, any organism which had succeeded in slightly modi- fying itself by this purposive response handed on the modification to its offspring. Thus the offspring started, so to speak, where the parents left off, and by developing the inherited modification achieved a still greater measure of racial differentiation. Thus a characteristic laboriously acquired by a parent appeared as a habit in the offspring, the offspring performing automatically and uncon- sciously activities which in the parent represented hardly- won acquisitions.
The connecting thread in this process was memory. The offspring does what its parents did and does it more easily because it remembers what they did. But how, it may be asked, can a child remember the activities of its parents ? Because, says Butler, it is its parents. Butler proceeds to explain this startling announce- ment by a disquisition on the subject of identity. There is some sense, though a remote one, in which a man of eighty is the same person as a boy of six, so that he can say, " I am the person who at the age of six did so and so." In precisely this same sense, whatever it is, the boy of six is the same as the pre- natal embryo from which he developed, the pre-natal embryo as the germ cell from which it developed, and the germ cell as the parents' bodies of which it once formed part. Therefore there is as much identity between a parent and a child, as between a child and an old man. The thread of continuity in virtue of which we assert this identity is memory, the baby chicken knowing that the first thing it must do with its beak is to peck its way out of the shell, because it remembers performing this action on countless previous occasions when it was in the persons of its ancestors. What is more, it knows that it must grow a horny piece of cuticle in the front of its face, and knows hair to grow it, because it has done it so often before, and grows it accordingly without knowledge or effort. Actions which have been repeated in this way on a vast number of occasions become habitual, and are performed instinctively without conscious attention. Our remote ancestors learned with difficulty to circulate their blood and to grow their hair and nails. We have performed these processes so frequently that we can now go through them without thinking about them, our energy and attention thus being set free for other purposes. New acquisitions obtained by this released energy and attention will, in due course, appear in our remote descendants, as inherited habits, with the result that there will one day be born a generation of babies who will know the multiplication table by instinct.
Thus we have a formula for progress in evolution. Evolution is creative and purposive : the life force acquires new faculties in the process of reacting to its external environment, and these new faculties appear as inherited endowments in its later manifestations. Life is not automatically determined by its environment. It grows and expresses itself in response to and in a sense in spite of its environment. One day, as in the last play of the Back to Methuselah Pentateuch, it will master its environment completely, and, ceasing to struggle to over- come matter, will proceed to uninterrupted contemplation.
This is all very well in its way ; the formula of creative evolution constructs an imposing edifice with space for many of the nobler aspirations of man. But there is one foundation stone upon which the whole structure rests. This is the doctrine that characteristics acquired by parents can be inherited by offspring. Can they in fact, or can they not ? The nineteenth century was on the whole inclined to say that they cannot. There was, as its men of science were never tired of pointing out, a complete lack of evidence and there was the germ cell theory of Weismann.
As regards the lack of evidence, take an acquired characteristic, or rather, since you can never be sure that you have found orie, manufacture one for yourself by cutting off the tails of a pair of mice. Their offspring will have tails of the normal length. As for Weismann he proved conclusively, as it was then thought, that the germ cell, although part of the parents' bodies, was screened from all the influences that affected the parents' bodies. The parent was in short merely a sort of postman, handing on a letter that had been entrusted to him by his parents, but having no power to alter its contents. If this were so, nothing that happened " to the parent could possibly alter the writing of the letter, and that it was so nearly everybody until a few years ago believed.
(To be concluded.)
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