Similarity of Various Theories 61 



itary factors are miscible, but the idioplasmic strands are 

 not. 



Variability teaches us that individual factors may con- 

 siderably increase, independently from others, and, 

 on the other hand, may almost completely disappear. And 

 in the formation of species this possibility has been util- 

 ized to the highest degree. In the solid union of the 

 idioplasm such a behavior of the individual "elements" 

 might be made extremely difficult, if not quite impossi- 

 ble. 



We cannot, therefore, maintain the solid union of the 

 "elements" into physiological units, ancestral plasms, or 

 idioplasm. This leads, not only in the cases mentioned, 

 but almost everywhere, to contradictions with the facts, 

 or at least to superfluous assumptions. But it is just on 

 this union that the originators of these theories have laid 

 the greatest stress, while they have nowhere emphasized, 

 as an independent assumption, the conception of the "ele- 

 ments," and have not considered that as a thing apart 

 from their other hypotheses. 



As soon as we do away with this union, the kernel of 

 all theories is the same as that of pangenesis, as has al- 

 ready been mentioned at the beginning of this Section. 



