OSTERHOUT— DYNAMICAL THEORY OF ANTAGONISM. 553 



It is clear that such consecutive reactions as are here discussed 

 must be the rule in living matter and that further study of their 

 dynamics should yield facts of importance. 



Summary. 



I. Data regarding the electrical resistance of living tissues of 

 Laininaria in NaCl .52 M, in CaCL .278 M, and in mixtures of 

 these are given. 



II. In order to explain these data it is assumed : 



1. That the resistance is determined by a substance M which 

 is formed and broken down by the reaction 



2. That CaCL accelerates the reaction A -^ M. 



3. That NaCl and CaCL combine with a substance in the proto- 

 plasm, forming a compound which inhibits the reactions A -^ M 

 and M-^B. 



III. On the basis of these assumptions a theory is developed to 

 explain : 



1. Why both NaCl and CaCL are toxic. 



2. Why when mixed in the proper proportions their toxicity is 

 greatly diminished (antagonistic action). 



3. Why they have opposite effects on permeability. 



4. Why the decrease of permeability produced by CaCL must 

 be followed by an increase when the exposure is sufficiently pro- 

 longed. 



5. Why all toxicity disappears in sea water. 



IV. The theory gives a quantitative explanation of the toxicity 

 of all the mixtures and enables us to predict the resistance {and 

 permeability) in any mixture at any moment during exposure. 



V. The fact is emphasized that life processes must consist 

 largely of consecutive reactions and that an analysis of the chemical 

 dynamics of these reactions is indispensable for the solution of cer- 

 tain fundamental problems of biology. 



Harvard University, 



Laboratory of Plant Physiology. 



