CHAPTER III.
THE PROBLEMS PRESENTED.
In his classical work on Heredity, Professor J. Arthur Thomson exhausts the evidence on Lamarckism available then (1908) in a manner worthy of the summing-up of an English judge. This is presented to the jury of the biological world and they are still considering it. Their verdict and his sentence are not yet delivered, and it may be they will still be long delayed. One might almost use the words of Professor Bateson, previously quoted, “on our present knowledge the matter is talked out.”
I will make one prophecy in this volume and predict that the fourth edition of this work in 1930 will contain the verdict of the jury and sentence of the distinguished judge to the effect that in the case Lamarck v. Weismann the plaintiff has won. As in the Great War the Old Contemptibles held their line with the utmost difficulty against the disciplined hosts of the greatest army ever known till then, and yet the latter found their First Battle of the Marne, so perchance it may be in the present struggle.
I introduce this chapter with an important passage from the above work on the Logical position of the Argument, in which the two possible methods of establishing the affirmative position of Lamarck are given; these are, first, actual experimental proof of transmission, and, second, a collection of facts which cannot be interpreted without the hypothesis of modification inheritance. The words are:[28] “The neo-Lamarckians have to show that the phenomena they adduce as illustrations of modification-inheritance cannot be interpreted as the results of selection operating on germinal variations. In order to do this to the satisfaction of the other side, the neo-Lamarckians must prove that the characters in question are outside the scope of natural selection, that they are non-utilitarian and not correlated with any useful characters—a manifestly difficult task. The neo-Darwinians, on the other hand, have to prove that the phenomena in question cannot be the results of modification-inheritance. And this is in most cases impossible.”[29]
I have placed this passage in italics because of its importance from the point of view of the two problems which I am presenting and would remark here that if only all the writers had used Professor Thomson’s term “modifications” instead of “characters” in the statement of this doctrine much confusion and evasion of plain facts would have been avoided, and yet such workers as the Mendelians, if deprived of their clear-cut term “characters” would have been less able to carry on their studies. To this point of terminology I refer below.[30]
In a world teeming with the life of plants and animals, and in the branch of science which seeks to interpret them, where we enter upon the unknown much sooner than in any other sphere of science, Weismann has set out to prove or maintain the most stupendous negative ever framed by the human mind. It would require generations of men to prove this negative, if it were probable, and his case rests mainly on the assumed weakness of his opponents. So what is needed and demanded from the neo-Lamarckians is the production of a few well-attested and verified facts, and, as he admits himself, then it must follow as the night the day that his followers will surrender his characteristic dogma. The more cautious leaders and teachers of the day say that this has not taken place and ask for facts, more facts and still more facts, and this attitude is both judicious and judicial, for example in a teacher so eminent as Professor J. Arthur Thomson. Scientific men, in such a position as he occupies with grace and distinction, owe a serious debt of loyalty to ultimate truth and to the inquiring minds of the young students of to-day and to-morrow. Those who are in a position of inferior responsibility and honour, and more freedom, just rank and file members of the Commons’ House of Parliament, may be pardoned if they do not exhibit an excess of deference to authority and if they think for themselves.