24 



Reversion due, in hybrids, to the effect of the 

 reducing divisions and favorable combinations ; 

 in pure races, to ids becoming dominant after 

 a latent period. 



Sexual dimorphism due to doubling of the de- 

 terminants for the sexual characters. 



Regeneration of lost parts due to special deter- 

 minants in the germ-plasm. 



Reproduction by fission the same process carried 

 farther. 



Budding due to a doubling of the ids of germ- 

 plasm. 



Alternations of generations due to the presence 

 of two kinds of germ-plasm in each reproduc- 

 tive cell. 



Weismannism criticised. 



Points probably well founded : — 



Inheritance of acquired characters unproved. 

 Idioplasm contained in chromatin of the 



nucleus. 

 Continuity of idioplasm between successive 



generations. 

 The characters of the offspring of germinal 

 and not of somatic origin. 



Main questions now under discussion : — 



Is there a real difference between germ-plasm 



and somatic idioplasm ? 

 Is development a process of evolution or of 



epigencsis .'' 

 May qualitative cell-division occur ? 

 How far is ontogeny due to the structure of 



the idioplasm and how far to environment ? 

 Is VVeismann's interpretation of the reducing 

 divisions correct ? 



