NUTRITION. 231 



contraction, secretion, heat, etc., just as coal is 

 expended to set the steam engine going. The proof 

 as far as the muscle is concerned does not stand 

 alone. There are other examples. In particular, 

 micrographic physiologists who have studied nervous 

 phenomena say that the anatomical elements of the 

 brain last indefinitely, and that they continue as they 

 are, without renewal from birth to death. The 

 permanence of the consciousness, be it said in 

 passing, is connected by them with the permanence 

 of the cerebral element (Marinesco). 



Thus destruction is very restricted. There is only 

 a very slight disassimilation of the living matter, 

 properly so-called, in the course of the vital functional 

 activity. We may even go farther than this ex- 

 perimental fact. This is what Le Dantec has done 

 when he claims that there is even an assimilation, an 

 increase of the protoplasm. Strictly speaking, this 

 is possible, but there is no certain proof of it ; and in 

 any case we cannot agree with him when he affirms 

 that the increase is the direct result of the functional 

 activity and blends with it in one single, unique 

 operation. We must, on the contrary, agree with 

 Claude Bernard that it is only a consequence of it, 

 that it is produced in consequence of the existence of 

 a bond of correlation between organic destruction and 

 assimilating synthesis. 



Why is there this bond ? That is easily under- 

 stood if we reflect that the assimilating synthesis, an 

 operation of endothermic, chemical complexity, natur- 

 ally requires an exothermic counterpart, the organic 

 destruction which will set free this necessary energy. 



Formative Assimilation of Reserve-stuff. Format 

 tive Assimilation of Protoplasm.-^\t follows that 



16 



