Thus Butler’s alleged retrogressions belong to the same order of thinking that we have seen shared by Driesch, Baldwin, and Jennings, and most explicitly avowed, as we shall see, by Francis Darwin. Semon makes one rather candid admission, “The impossibility of interpreting the phenomena of physiological stimulation by those of direct reaction, and the undeception of those who had put faith in this being possible, have led many on the _backward path of vitalism_.” Semon assuredly will never be able to complete his theory of “Mneme” until, guided by the experience of Jennings and Driesch, he forsakes the blind alley of mechanisticism and retraces his steps to reasonable vitalism. * * * * * But the most notable publications bearing on our matter are incidental to the Darwin Celebrations of 1908–9. Dr. Francis Darwin, son, collaborator, and biographer of Charles Darwin, was selected to preside over the Meeting of the British Association held in Dublin in 1908, the jubilee of the first publications on Natural Selection by his father and Alfred Russel Wallace. In this address we find the theory of Hering, Butler, Rignano, and Semon taking its proper place as a _vera causa_ of that variation which Natural Selection must find before it can act, and recognised as the basis of a rational theory of the development of the individual and of the race. The organism is essentially purposive: the impossibility of devising any adequate accounts of organic form and function without taking account of the psychical side is most strenuously asserted. And with our regret that past misunderstandings should be so prominent in Butler’s works, it was very pleasant to hear Francis Darwin’s quotation from Butler’s translation of Hering {0l} followed by a personal tribute to Butler himself. * * * * * In commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of the “Origin of Species,” at the suggestion of the Cambridge Philosophical Society, the University Press published during the current year a volume entitled “Darwin and Modern Science,” edited by Mr. A. C. Seward, Professor of Botany in the University. Of the twenty-nine essays by men of science of the highest distinction, one is of peculiar interest to the readers of Samuel Butler: “Heredity and Variation in Modern Lights,” by Professor W. Bateson, F.R.S., to whose work on “Discontinuous Variations” we have already referred. Here once more Butler receives from an official biologist of the first rank full recognition for his wonderful insight and keen critical power. This is the more noteworthy because Bateson has apparently no faith in the transmission of acquired characters; but such a passage as this would have commended itself to Butler’s admiration:—