Characters, Hereditary and Acquired. 123 



in the case of higher plants, and this under circum- 

 stances which carry much less equivocal evidence 

 of the inheritance of acquired characters, than can 

 be rendered by the much more simple organization 

 of an alga. 



I have previously mentioned Hoffmann's experi- 

 ments on transplantation, the result of which was 

 to show that variations, directly induced by changed 

 conditions of life, were reproduced by seed *. Weis- 

 mann, however, as we have seen, questions the 

 somatogenetic origin of these variations — attributing 

 the facts to a blastogenetic change produced in the 

 plants by a direct action of the changed conditions 

 upon the germ-plasm itself^- And he points out 

 that whether he is right or wrong in this inter- 

 pretation can only be settled by ascertaining whether 

 the observable somatic changes occur in the genera- 

 tion which is first exposed to the changed conditions 

 of life. If they do occur in the first generation, they 

 are somatogenetic changes, which afterwards re-act 

 on the substance of heredity, so as to transmit the 

 acquired peculiarities to progeny. But if they do 

 not occur till the second (or any later) generation, 

 they are presumably blastogenetic. Unfortunately 

 Hoffmann does not appear to have attended to 

 this point with sufficient care, but there are other 

 experiments of the same kind where the point has 

 been specially observed. 



For instance, M. L. A. Carri^re ^ gathered seed from 

 the wild radish {Raphanus Raphatiistrum) in France, 



' Examination of Weismannism, p. 93. ' Ibid. p. 153. 



' Origine des Plantes Domestiques, dlmontrle par la culture du Radis 

 Sauvage (Paris, 1869'). 



