Characters, Hereditary and Acquired. 135 



questioning the hypothetical basis of his funda- 

 mental postulate touching the absolute continuity of 

 germ-plasm. It is one merit of Galton's theory, as 

 against Weismann's, that it does not dogmatically 

 exclude the possible interruption of continuity on 

 some occasions and in some degree. Herein, indeed, 

 would seem to lie the central core of the whole 

 question in dispute. For it is certain and has long 

 been known that individually acquired characters 

 are at all events much less heritable than are long- 

 inherited or congenital ones. But Lamarckian theory 

 supposes that congenital characters were in some 

 cases originally acquired, and that what are now 

 blastogenetic characters were in some cases at first 

 somatogenetic and have become blastogenetic only 

 in virtue of sufficiently long inheritance. Since 

 Darwin's time, however, evolutionists (even of the 

 so-called Lamarckian type) have supposed that 

 natural selection greatly assists this process of deter- 

 mining which somatogenetic characters shall become 

 congenital or blastogenetic. Hence all schools of 

 evolutionists are, and have long been, agreed in 

 regarding the continuity principle as true in the main. 

 No evolutionist would at any time have propounded 

 the view that one generation depends for all its 

 characters on those acquired by its immediate ances- 

 tors, for this would merely be to unsay the theory of 

 Evolution itself, as well as to deny the patent facts 

 of heredity as shown, for example, in atavism. At 

 most only some fraction of a per cent, could be 

 supposed to do so. But Weismann's contention is 

 that this principle is not only true in the main, but 

 absolutely true ; so that natural selection becomes all 



