Weismannism up to date (1893). r 4 r 



My second remark is a brief one — viz., that the 

 whole question is of so very speculative a character, 

 that I cannot see the smallest use in debating it. 



The only remaining point of difference between 

 strip and germ-plasm is the one referring to stability. 

 Needless to say, Galton is at one with Weismann in 

 recognizing a high degree of stability on the part of 

 the substance of heredity; but the agreement extends 

 only so far as is necessitated by the facts of atavism, 

 &c. Indeed, he does not even mention — although he 

 perhaps implies — what Weismann has called amphi- 

 mixis as among the factors of individual congenital 

 variation. Weismann, on the other hand, has hitherto 

 regarded amphimixis as the sole cause of all such 

 variations. But, as we shall presently find, in his 

 recent work on The Germ- plasm he has now greatly 

 modified his views upon this subject, and, in fully 

 recognizing the " factors " of variability to which 

 Galton alludes, has correspondingly lessened the 

 difference between germ-plasm and stirp. But this is 

 a point which can be better dealt with when we come 

 to consider the important modifications which in this 

 respect the theory of germ-plasm has undergone. 



The only other matter which has to be mentioned 

 in connexion with Weismann's theory of heredity is, 

 that in The Germ-plasm he has for the first time given 

 us his views upon the influence of a previous sire on 

 the progeny of a subsequent one by the same dam. 

 The phenomena in question, which I have already 

 detailed in pp. 77-9, no, he designates by the term 

 " telegony." The analogous phenomena in plants he 

 calls, following Focke, " xenia." 



