210 Pang ens in the Nucleus and Cytoplasm 



therefore permissible to infer the actual occurrence of a 

 general intercellular transmission of the bearers of hered- 

 itary properties. 



Hence, the answer to the question must be looked for 

 In a quite different field. The theory of heredity must 

 tell us whether there are facts for the explanation of 

 which the assumption of an intercellular transmission is 

 indispensable. 



To my mind, this is not the case, as I have already 

 stated in the Introduction. I have there referred to Weis- 

 mann's writings, which contain copious demonstrations 

 that all observations which so far seemed to demand such 

 an assumption, could in reality have been explained as 

 well, and in most cases better, without them. 



Especially should the so-called heredity of acquired 

 characters be mentioned here. I have previously, in an- 

 other place, drawn attention to the fact that in many cases 

 we have here to deal with malformations.^^ If we limit 

 the meaning of that expression to the variations which 

 have arisen on the somatic tracks, and ask whether these 

 can be transmitted to the germ-tracks of the organism, 

 then the question has a clear meaning. In that case we 

 can join Weismann in quietly answering, no. But, if we 

 also call such characters as may have originated on the 

 germ-tracks acquired, the question is no longer of any 

 significance for the problem which occupies us here.^* 



In botany graft-hybrids and xenia are mentioned as 



i3"0ver steriele Mais-planten," Jaarboek v. h. Vlaamsch kruidk. 

 Genootschap, Bd. 1. Gent. 1889. 



i*The conception of germ-tracks and somatic tracks in the sense 

 developed in the first Section of this second Part may contribute 

 much, in this connection, to help the mutual understanding. See also 

 e. g., in regard to Eimer's discussions, his work: Die Entstehung der 

 Arten auf Grund von Vererhen erworhener Eigenschaften. Theil 1. 

 1888. 



