52 CELLULAR PHTSIOLOGT 



bicarbonate, and becomes potassium chloride by 

 exchange of the carbonate and bicarbonate ions 

 produced inside the cell for chloride ions coming 

 in from the sea water. The distribution of chlo- 

 ride ions would be determined in this case by the 

 Donnan principle (cf. Osterhout, W. J. V., 

 Proc. Soc, Exfer, Biol, and Med.y 1926, xxiv, 

 Dec. No.). 



The fact that the electrical resistance of the 

 protoplasm is so high might be explained, as 

 stated above, by supposing that the outer layer 

 of the protoplasm consists of a layer which is 

 only slightly permeable to ions and which acts 

 to a considerable extent as a condenser. Later in- 

 vestigations by Dr. Blinks indicate that (due to 

 the polarization capacity) much the same effect 

 would be produced if ions of one sign entered 

 the protoplasm much more readily than those 

 with the opposite charge. Further investigation 

 will be needed in order to clear up this question. 



