222 Inheritance of Acquired Characters 



natural selection, panmixia or something else, and that 

 consequently they have become arrested in successive 

 ontogeneses at successively earlier stages of development. 

 But the question cannot be repeated often enough; how 

 can this theory explain the growth of these organs up to 

 a certain stage of development and their retrogression 

 and disappearance in the later stages? 



In short, it seems to us that one cannot imagine a 

 more complete overthrow even from a purely logical 

 point of view, where it is only a matter of avoiding con- 

 tradiction on one's own premises, than thrt suffered by 

 Weismann in the attempt to find an explanation of the 

 repetition of phylogeny by ontogeny, and one can hardly 

 bring forward a more thorough failure of a theory built 

 up laboriously with the object of explaining all the differ- 

 ent phenomena of heredity, even the most peculiar and 

 secondary ones, than appears in the fact that this theory 

 is not even capable of giving the least explanation of the 

 most general biogenetic phenomenon the one which 

 underlies all the others. And this contradiction and this 

 failure do not appear so much in the minute and partic- 

 ular parts of Weismann's theory, in which it deals with 

 this or that peculiar detail, but much rather in the theory 

 itself in all its generality, which disputes the inheritance 

 of acquired characters. Weismann and his supporters 

 can, if the most evident facts are not enough for them, 

 deny this law of recapitulation. But that they admit it 

 and nevertheless dispute inheritance, this is a contradic- 

 tion from which the opponents of the Lamarckian 

 principle cannot escape now or ever a destructive rock 



upon which all their theories are wrecked. 



* * * * * * * 



If now we sum up succinctly the discussion in this 



