634 J\^hiclcs of the Hereditary Characters. 



whom the character of every species constitutes an in- 

 separable whole and every material vehicle, therefore, 

 represents the sum of all its qualities. The adiierents 

 to this view are still in the majority. It is the very 

 opposite of Darwin's view, according to which the indi- 

 vidual cells of the organism and the individual compo- 

 nent elements within the cells each have their special 

 representatives in the hereditary substance. Thus the 

 material basis of inheritance is composed of as many 

 different units as there are separate organs and types 

 of cells. 



Nageli has introduced the word idioplasma for this 

 material basis ; and for many reasons this term should 

 be universally employed, especially since it can be used 

 in speaking of the two opposite theories. To Xageli 

 the idioplasm was a imit, but we may, as well, apply this 

 term to the sum total of Darwin's tmits. 



The independent behavior of the individual hereditary 

 characters both in the process of mutation and in hybridi- 

 zation, definitely proves, in my opinion, the correctness of 

 Darwin's assumption of separate material bases for 

 each one of them ; and the whole contrast between muta- 

 bility and fluctuating variability can only be brought into 

 harmony with the theory in the light of this principle.^ 



Darwin's pangenesis may be summarized in the two 

 following theses.^ 



The individual cells and organs of the whole organ- 

 ism are represented in every germ cell and every bud by 



^ The correctness of this view receives strono- support from the 

 fact that those of my critics who are partisans of Wallace^s form 

 of the theory of selection, simply deny the distinction between muta- 

 bility and fluctuating variabih'ty. See above, p. 599. 



^Darwtx, Animals 011 d Plants under Donicsficafion. Vol. TT, 

 Chapter on Pangenesis; and my Intracellular Pangenesis (Engl, ed.), 

 pp. 5 and 60. 



