246 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



are to signify anything specifically determined, that is 

 something other than what chemists call " synthesis " 

 and " analysis," and whenever at the same time they claim 

 to be used in any strict meaning at all, they can only mean 

 that there is a something of a specific chemical nature, yet 

 intimately bound up with life itself, which has the power 

 of making other less complicated chemical materials like 

 itself or of producing from itself less complicated materials 

 by an analytical process. 



Let it be clearly understood : the word " assimilation " 

 does not mean that there is a fundamental material A of 

 given quantity, to which external means and forces add a 

 further quantity, but it expresses that the material A 

 increases by its own action at the cost of the components 

 of the medium in the broadest sense. 



Taking the word assimilation in this usual sense, the 

 question of course would arise as to the kind of forces 

 " assimilating," that is, equalising foreign materials to the 

 material A and seated in A at the same time. But it 

 seems to me that another question should be settled first, 

 which is perhaps of a still deeper importance, though it does 

 not sound so theoretical. 



The " Living Substance " in the Chemical Sense 



I am thinking of the very simple but very fundamental 

 question : Does assimilation in the sense we have indicated 

 really take place ? Does the chemically distinctive 

 substance A, the so-called " living substance," exist at all ? 

 Are there any criteria of its existence ? There are in fact 

 many theoretical authors who have answered these two 



