CRYSTALLOID IN LIVING CELLS 17 



of cell activity which we know as internal secretions, lysins, anti- 

 bodies, toxins, hormones, S.v. 



Turning now from the organic foodstuffs and the synthesised 

 products of metabolism to the inorganic crystalloids of the cells 

 and body fluids, we find abundant evidence of union in labile 

 equilibrium between these and the organic constituents of the 

 body unions which are absolutely essential to the life and work 

 of the cell, specific in character from one type cff cell to another, 

 and which owe their peculiar and effective functional power in 

 the life of the cell to the very feebleness of the union which allows 

 of interchange and reaction. So that we have stability of the 

 whole system in the midst of and indeed as a consequence of the 

 instability of the constituent parts. 



The first evidence which may be quoted in favour of this form 

 of union is the peculiar distribution of the inorganic salts and ions 

 as between tissue cells and their environing fluids, the plasma and 

 lymph. 



Although the same inorganic salts are present in the cells 

 of the tissue and in the blood corpuscles as are found in 

 the lymph and plasma, the quantitative distribution is very 

 different in the two cases. The cells are rich in potassium and 

 phosphatic ions, and relatively poor in sodium and chlorides, 

 while the converse holds in the case of the bathing fluids of 

 the cells. 



This peculiar distribution . finds an easy explanation on the 

 basis that the proteins of the cells are so constituted chemically 

 that they possess affinities for absorbing or uniting with potassium 

 and phosphatic ions, and have no such power for holding sodium 

 and chlorine, while the converse holds for the proteins of the plasma. 

 For under these conditions, with the same osmotic pressure of 

 dissolved constituents within and without the cell, any particular 

 ion will increase in amount inthe absorbed or united form in that 

 particular region where protein is found possessing an affinity 

 for it. 



No other view which has been put forward furnishes an ade- 

 quate explanation of this peculiar distribution of the salts. The 

 other view which has obtained most adherence is that there exist 

 membranes with peculiar and specific properties surrounding the 

 cells which present a varying resistance to the passage of different 

 ions. These membranes, which recently have been regarded as 



B 



