46 Darwiriy and after Darwin. 



these endowments in a dormant state through a long 

 series of generations until at last they re-appear 

 in what we recognize as recursions. Thus far all 

 three theories are in agreement. In fact, the only 

 matter of any great importance wherein they disagree 

 has reference to the doctrine of Continuity ^ For 

 while Darwin's theory supposes the substance of 

 heredity to be mainly formed anew in each ontogeny, 

 and therefore that the continuity of this substance is 

 for the most part interrupted in every generation ^, 

 Weismann's theory supposes this substance to be 

 formed only during the phylogeny of each species, 

 and therefore to have been absolutely uninterrupted 

 since the first origin of life. 



But now, Galton's theory of heredity stands much 

 nearer to Weismann s in this matter of Continuity; 

 for it is. as he says, a theory of " modified pangenesis," 

 and the modification consists in allowing very much 

 more for the principle of Continuity than is allowed 

 by Darwin's theory : in fact he expresses himself as 

 quite willing to adopt (on adequate grounds being 

 shown) the doctrine of Continuity as absolute, and 

 therefore propounded, as logically possible, the iden- 

 tical theory which was afterwards and independently 

 announced by Weismann. Or, to quote his own 

 words — 



"We iTiij.;ht almost reserve our belief that the structural [i. e. 

 somatic] cells can react on the sexual elements at all, and we 



' Originally, Weismann's further assumption as to the perpetual 

 stability of germ-plasm, " since the first origin of sexual reproduction," 

 was another very important point of difference, but this has now been 

 withdrawn. 



' 1 say '■ mainly formed anew," and "for the most part interrupted," 

 because even Darw in's theory does not, as is generally supposed, exclude 

 the doctrine of Continuity in toto. 



