142 Darwin as an Anthropologist 



of transformative heredity, and applies the two in conjunction to the 

 facts of histology. He lays stress on the significance of functional 

 adaptation, which I had described in 1866, under the head of cumu- 

 lative adaptation, as the most important factor in evolution. Pointing 

 out its influence in the cell-life of the tissues, he puts "cellular 

 selection" above "personal selection," and shows how the finest 

 conceivable adaptations in the structure of the tissue may be brought 

 about quite mechanically, without preconceived plan. This "me- 

 chanical teleology" is a valuable extension of Darwin's monistic 

 principle of selection to the whole field of cellular physiology and 

 histology, and is wholly destructive of dualistic vitalism. 



The most important advance that evolution has made since 

 Darwin and the most valuable amplification of his theory of selec- 

 tion is, in my opinion, the work of Richard Semon: Die Mneme 

 als erhaltendes Priiizip im Wechsel ties organischen Geschehens 1 . 

 He offers a psychological explanation of the facts of heredity by 

 reducing them to a process of (unconscious) memory. The physio- 

 logist Ewald Hering had shown in 1870 that memory must be 

 regarded as a general function of organic matter, and that we are 

 quite unable to explain the chief vital phenomena, especially those 

 of reproduction and inheritance, unless we admit this unconscious 

 memory. In my essay Die Perigenesis der Plastidule 2 I elabo- 

 rated this far-reaching idea, and applied the physical principle of 

 transmitted motion to the plastidules, or active molecules of plasm. 

 I concluded that "heredity is the memory of the plastidules, and 

 variability their power of comprehension." This "provisional attempt 

 to give a mechanical explanation of the elementary processes of 

 evolution" I afterwards extended by showing that sensitiveness is 

 (as Carl Nageli, Ernst Mach, and Albrecht Rau express it) a general 

 quality of matter. This form of panpsychism finds its simplest 

 expression in the "trinity of substance." 



To the two fundamental attributes that Spinoza ascribed to 

 substance — Extension (matter as occupying space) and Cogitation 

 (energy, force) — we now add the third fundamental quality of 

 Psychoma (sensitiveness, soul). I further elaborated this trinitarian 

 conception of substance in the nineteenth chapter of my Die 

 Lebenswunder (1904) 3 , and it seems to me well calculated to afford a 

 monistic solution of many of the antitheses of philosophy. 



This important Mneme-theory of Semon and the luminous 

 physiological experiments and observations associated with it not 

 only throw considerable light on transformative inheritance, but 

 provide a sound physiological foundation for the biogenetic law. 



1 Leipzig, 1904. 2 Berlin, 1876. 



3 Wonders of Life, London, 1904. 



