252 PROTOPLASMIC ACTION AND NERVOUS ACTION 



structure of living matter and the various facts showing 

 the dependence of stimulation on membrane processes 

 are taken into consideration. The general susceptibility 

 of living matter to electrical influence suggests that in 

 protoplasm there may be a similar dependence of the 

 chemical reactions upon processes of electrolysis occurring 

 at the boundaries between the protoplasmic phases. 

 This general interpretation is also consistent with the 

 readiness and rapidity with which chemical influence is 

 transmitted from region to region in Hving matter; 

 the many close resemblances between such transmissions 

 and the transmission of the waves of electro-chemical 

 alteration over the surface of mercury or passive iron will 

 be considered later in detail. In these inorganic systems 

 the chemical reactions are directly determined by the 

 potential-differences existing between different portions 

 of the metalhc surface; these potential-differences arise 

 as the result of local alterations of the surface-films, and 

 the local circuits thus arising effect the chemical change 

 by electrolysis. Similarly in living matter the waves of 

 chemical and physiological alteration accompanying the 

 transmission of stimulation (i.e., excitation-waves, nerve- 

 impulses, etc.) are always associated with waves of 

 electromotor variation. Bernstein first showed for 

 motor nerves (in 1866) that the physiological effect and 

 the bioelectric variation have the same velocity of propa- 

 gation;^ and all of the more recent evidence confirms 

 the view that the electric variation is the essential 

 component of the transmitted process. 



Recently I have discussed in some detail the parallels 

 between the transmission of chemical effects in systems 



Cf. Bernstein's Elektrobiologie, chap, iii, for references. 



