HEREDITY. 



471 



such in its effects. Moreover, Von Rath omits to men- 

 tion the fact that in traversing the soma, the stimulus, 

 frequently, if not always, produces effects on the latter 

 similar to those which it produces on the germ-plasma. 

 I should call this process the inheritance of an acquired 

 character, even in the case where no corresponding 

 modification appears in the soma, since the causative 

 energy is acquired by the soma and is not derived from 

 the existing germ-plasma. 



Romanes 1 says, in reviewing the opinions of Weis- 

 mann : "(i) Germ-plasm ceases to be continuous in 

 the sense of having borne a perpetual record of con- 

 genital variations from the first origin of sexual propa- 

 gation. (2) On the contrary, as all such variations have 

 been originated by the direct action of external conditions 

 [italics mine], the continuity of the germ-plasm in this 

 sense has been interrupted at the commencement of 

 every inherited change during the phylogeny of all 

 plants and animals, unicellular as well as multicellular. 

 (3) But germ-plasm remains continuous in the re- 

 stricted though highly important sense of being the 

 sole repository of hereditary characters of each succes- 

 sive generation, so that acquired characters can never 

 have been transmitted to progeny 'representatively,' 

 even though they have frequently caused those 'spe- 

 cialized ' changes in the structure of germ-plasm, which 

 as we have seen, must certainly have been of con- 

 siderable importance in the history of organic evolu- 

 tion." 



Here the inheritance of characters acquired by the 

 soma is admitted, and the process is after the method 

 of diplogenesis. According to Romanes, Galton origin- 



lAn Examination of Weismannism, Chicago, 1893, p, 169. 



