ERNST G. HUF 



E 20 



No']^ = 47 9 j[Na*] =119 3 



[no'] = 169 3 peg /ml -h 



LOG [k*] 



Fig. II. Data on net uptake by epithelium and net release from corium of potassium, 

 sodium and water, as a function of extracellular potassium ion concentration [K"^]e, in fiEq/ 

 ml (2Q). 



polassium ions. Should this be possible, it would then seem feasible also to 

 approach the problem of the state of potassium in frog skin stoichiometrically, 

 i.e. from the standpoint of multiple ion equilibria, as treated by Klotz (37, 38). 

 It has been emphasized and illustrated in tigure 7 that maintenance of active 

 salt and water transport is dependent upon a sufficient potassium ion level of 

 the environment. More details about this relationship are given in figure 11. 



