From the Unconscious to the Conscious 



not only is living matter not destroyed by use, but that 

 it increases. 



It would seem that nothing should be easier than 

 to decide experimentally the problem of cellular destruc- 

 tion, by quantitative analysis of the nitrogenous waste 

 in the urine. In fact it is very difficult to distinguish 

 between the part that comes from the albuminoids in 

 food, and that which comes from waste of the organism ; 

 and the best conducted researches such as those of Igo 

 Kaup still give uncertain results. 



But in default of proof from the laboratory, reasoning 

 suffices to prove the perpetual destruction and restora- 

 tion of cellular protoplasm. 



At the outset and, a priori, without need of demonstra- 

 tion, it seems that such a tiny element as the living cell 

 should necessarily have short life; much shorter in any 

 case, than that of the organism to which it belongs. It 

 would therefore be renewed x times during the life of 

 that organism. 



Further, the imperious necessity for ingestion by the 

 living being of nitrogenous elements in considerable 

 quantity can be explained only by the needs of cellular 

 regeneration. Otherwise we should be driven to the 

 absurd supposition that the nitrogen is ingested to be 

 immediately eliminated, and is not an indispensable 

 nutriment, while the contrary is well established. 



Therefore, even if further research should prove 

 that the living cell remains intact, as a framework, 

 throughout life, that would by no means imply that it 

 remains intact as to its constituent molecules. 



The problem of molecular renewal replaces that of 

 cellular renewal, and the question remains neither more 

 nor less mysterious. Thus the * directive idea ' neces- 

 sarily presides over the maintenance of the personality as 

 it presides at its building up. 



The difficulties which we have rapidly reviewed are 

 already considerable; but they are as nothing compared 



45' 



