OSTERHOUT— DYNAMICAL THEORY OF ANTAGONISM. 539 



well with the curve of resistance in 65 NaCl -f- 35 CaCU obtained 

 experimentally. 



We see that in 65 NaCl -{- 35 CaCL the resistance of the tissue 

 behaves as if it were directly proportional to y (the amount of M) 

 when the velocity constant of A-^M is .000481 and the velocity 

 constant of M-^B is .00859. ^^ may interpret this to mean that 

 some substance, A, in the protoplasm breaks down to form M, the 

 substance to which the resistance of the protoplasm is due, and this 

 is in turn decomposed, the two reactions having the velocities 

 indicated. 



By making this very reasonable assumption we can account for 

 all the curves of resistance obtained experimentally. 



In order to see how this may be accomplished we may calculate 

 the constants of all the curves, proceeding in the same manner as 

 in calculating the constants of the curve of 65 NaCl -|- 35 CaCU. 

 For this purpose we assume various values until the correct ones are 

 discovered. The values obtained by this method are given in 

 Table I. 



Table I. 



Relation of K2 to Na^AXaCI^. 



Constants obtained by trial. 



An inspection of Table I. shows that as the amount of CaCL 

 increases, the value of Ko first falls and then rises, the minimum 

 value occurring at 95.24 NaCl -f 4.76 CaCL (which is the mixture 

 in which the tissue lives longest). It is evident that in each mixture 

 of NaCl -|- CaCL a substance is formed which in some way reduces 



