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.