Driesch 245 



For the specific protoplasm which a certain cell has 

 already acquired at a given moment of ontogeny by re- 

 ceiving only one certain stimulus corresponding to its 

 immediately preceding specificity, would really become 

 the special cause by which among all possible nuclear 

 energies only that one becomes liberated which should 

 become active at that instant. The activation of this new 

 nuclear energy would in its turn modify the specificity of 

 the protoplasm of this cell and of its immediate descend- 

 ants; and this protoplasm so altered would then become 

 the cause of the reception of a new specific stimulus and 

 of the consequent liberation of the next required nuclear 

 energy ; and so on up to the completion of development. 



Each cell of any given ontogenetic stage would thus 

 come to carry in itself all that is necessary to determine 

 its own future character and that of its most remote 

 descendants, with the exception of the various stimuli 

 which it is the duty of the protoplasm to select and to 

 receive. 



One thing is not quite clear in this. Do these liberat- 

 ing causes of the different nuclear energies, that is these 

 stimuli, among which each protoplasm should select and 

 receive only those belonging to it, come only from the 

 world outside the organism, or also from the reciprocal 

 actions of the individual parts in the interior of the 

 organism ? In the first case it would be necessary to place 

 Driesch among the out and out evolutionists; in the 

 second, his theory would be a mixed one, that is it would 

 rest upon phenomena of evolutionistic nature combined 

 with others of epigenetic nature. 



We shall not set forth any further here what enor- 

 mous difficulties one would encounter in either case if one 

 sought to build up in accordance with this theory any 



