PKESIDENTIAI. ADDRESS. 33 



cells can react on the sexual elements at all, and we may be 

 confident that at the most they do so in a very faint degree ; 

 in other words that acquired modifications are barely, if at all, 

 inherited, in the correct sense of that word. If they were not 

 heritable, then the second group of cases would vanish, and we 

 should be absolved from all further trouble about them ; but 

 if they exist, in however faint a degree, a complete theory of 

 heredity must account for them. I propose, as alread}^ stated, 

 to accept the supposition of their being faintly heritable, and 

 to account for them by a modification of pangenesis." 



I am not aware that l\Ir. Galton has modified the views here 

 expressed since the date of that paper, but in all his subsequent 

 ones, as well as in his work on "Hereditary Genius" (iSyg) 

 he continues to emphasize the paramount importance of the 

 latent elements in heredity, and the superiority, as he forcibly 

 expresses it, of nature over nurture. 



TEACHINGS OF PROFESSOR WEISMANN. 



The vigorous onslaught which has been made upon the doc- 

 trine of the transmission of acquired characters, since the date 

 of Mr. Galton 's papers, and apparently without a knowledge 

 of them, by Prof. August Weismann of the University of Frei- 

 burg has probably aroused a greater amount of interest among 

 scientific men than any other event that has transpired since 

 the appearance of Darwin's Origin of Species. Professor Weis- 

 mann is an embrjologist and histologist and has conducted a 

 series of prolonged and successful investigations upon several 

 groups of lowly organisms. But he has looked beyond the 

 special facts which are immediately connected with his re- 

 searches and has thought out for himself all the deeper prob- 

 lems of biology. Besides making himself complete master of 



