Authority.
We have then Weismann and Professor Bateson definitely ranged against the position taken in this volume as to a cause or origin or variation and the inheritance of acquired characters. To these we must add the great weight of Sir E. Ray Lankester’s opinion lately given in a reply to Professor Adami that “it is very widely admitted (more correctly “claimed”) that no case of the transmission of what are called acquired characters from parent to offspring has been demonstrated in so far as those higher animals and plants which multiply by means of specialised egg-cells and sperm-cells are concerned.”
It is not necessary to mention more than these “three mighties” of the biological world.
Many others such as Prof. J. Arthur Thomson and Prof. W. K. Brooks, of Johns Hopkins University, are still unconvinced as to Lamarckian factors and ask for more evidence, and they have many to support them in their opinion and claim. There is often a tone of weariness, as well as wariness in their remarks on the matter.
In favour of the neo-Lamarckian position, with which stands or falls the suggested cause of variation, there is a growing body of opinion, with the mention of which I conclude this review.
1. The accomplished writer of Form and Function, Mr. E. S. Russell, says the theory of Lamarck “although it had little influence upon biological thought during and for a long time after the lifetime of its author, is still at the present day a living and developing doctrine.”[27]
2. Sir Francis Darwin from the Presidential Chair of the British Association of Science in Dublin in 1908 proclaimed his adherence to the mnemonic theory of heredity, foreshadowed by Samuel Butler and inaugurated by Semon, a condition of which is that acquired characters are inherited. This caused much stir in the camp of “our friends the enemy.”
3. Observations and experiments at variance with germinal selection and its negative presupposition have been rapidly accumulated from the work of botanists and zoologists who were prepared to appeal to the tribunal of natural processes; though Weismann and some of his followers, with some reason, look upon the evidence from plants as a weak link in the chain of evidence. Many of the observations and experiments are well-known and only a mere mention of them need be made here, they are such as Mr. J. T. Cunningham’s observations on the effect of light on the under surface of flounders, Kammerer’s on the changes in the colour of salamanders to surrounding objects, and others by him on certain amphibia and reptiles especially alytes held by Professor McBride to be convincing, though the latter are to be repeated at the London Zoological Society’s gardens and are therefore sub judice—others on brine-shrimps, on the effects of change of food on bee-grubs and tadpoles, and of the change of level of environments of certain cereals—others by Henslow on plants which have never been refuted, and many by the late Prince Kropotkin. The latter have appeared at length in certain issues of the Nineteenth Century in September 1901, March 1912, October 1914, and the last in January 1919, and they deal both with plants and animals, and are too numerous to be mentioned here individually.
Again, Professor Dendy as President of the Zoological Section of the British Association of Science in September, 1914, devoted most of his address to the subject of Lamarckism and firmly claimed as a necessary factor of evolution “the direct response of the organism to environmental stimuli at all stages of development, whereby individual adaptation is secured, and this individual adaptation must arise again and again in each succeeding generation.” He also maintains this position in several passages in his important work Outlines of Evolutionary Biology published in 1912.
A statement by Professor Bower, President of the Botanical section of the British Association of Science in 1914 should also be noted: “I share it (the doctrine in question) in whole or in part with many botanists, with men who have lived their lives in the atmosphere of observation and experiment found in large botanical gardens and not least with a former President of the British Association, viz., Sir Francis Darwin.”
Professor Adami, in 1917, published an original work called Medical Contributions to the Study of Evolution in which from his extensive knowledge of the subject he deals with evidence of inheritance of acquired characters in lowly organisms as well as higher animals from the point of view of pathology.
Enough has been stated here to show that the dogma of Weismann or Lamarckian factors in organic evolution, quâ authority, has been in poor case during recent years, and it remains for me now to add my small quota of the authority of facts.
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.