SO-CALLED FORMATIVE SUBSTANCES. 169 



present no such organization of dissimilar molecules. Thus \ve 

 are again in danger of being regarded as vitalists. Even if we 

 assert that this organization is finally reducible to a physico- 

 chemical basis we cannot show how it is reducible. In any case 

 we are adopting a position for which the facts afford no warrant ; 

 moreover, we are assuming in our hypothesis exactly that which 

 the hypothesis is supposed to explain, i. e., we postulate one 

 organization in order to explain another. Naturally if organiza- 

 tion forms the basis of the hypothesis no real difficulties will be 

 encountered in individual cases for we can refer them at once to 

 the hypothetical organization. One frequently reads that a con- 

 siderable degree of organization is necessary for the phenomena 

 of life, that protoplasm possesses a high degree of morphological 

 organization, etc. The authors of these statements do not always 

 inform us as to the nature of this organization, but there is, I 

 think, no escape from the conclusion that unless we admit that a 

 molecule or a physical complex of molecules can exhibit the 

 phenomena of organic life our hypotheses are open to the objec- 

 tions stated above. 



In his earlier work Weismann designated the ultimate units 

 postulated in his hypothesis as molecules but later asserted that 

 they are not molecules in the physical sense, but consist of a 

 number of such molecules. Unless these complexes are purely 

 physical, and so far as I can determine, Weismann does not seem 

 to regard them as such, his hypotheses is open to these same 

 objections. Other similar " organization" hypotheses are in the 

 same position. 



THE HYPOTHESIS OF EPIGENETIC ORIGIN OF FORMATIVE 



SUBSTANCES. 



If a development of new formative substances from previously 

 existing substances occurs during development we come ulti- 

 mately as regards ontogeny to the primitive germ-cell which 

 must be composed either of a formative substance or of a com- 

 plex of substa-nces from which the substances appearing in later 

 stages arise. At the present time probably no one would regard 

 the primitive germ-cell as containing only a single formative sub- 

 stance but such a hypothesis would be a contradiction in terms 



