PHYSICO-CHEMICAL BASIS OF. TRANSMISSION 3^)1 



view has more recently been cm])hasizccl by Cremer in an 

 important series of studies on the '' Kernlcilfr" thcon-, 

 published at intervals since 1899. ^^^ assumes in ners'c, 

 in addition to the physical polarization which this tissue 

 exhibits in common with artificial systems of the core- 

 conductor type, the presence of a special "physioloj^'ical 

 polarization,'" by which term he means some active 

 process (in the nature of a response or reaction ) exhibited 

 at the regions of entrance and exit of the current; this 

 process he conceives as based on a chemical change of 

 some kind, which secondarily may alter polarization and 

 hence serve as the source of a current. In this manner 

 the polarization effect may be renewed at successive 

 areas of a nerve, and transmission to an indefinite 

 distance becomes possible.^ 



In the foregoing form the Kernleiter theory rccjuircs 

 only slight modification in order to make it entirely 

 consistent with the present form of the "membrane'' 

 theory. Both theories agree that a change ol ])olari/a- 

 tion is the critical or primary event in the local stimuhi- 

 tion process. Evidently if the polarization is confined 

 to the surface of the protoplasmic element (as also of the 

 metal in a core-conductor), this critical change is a 

 surface change. According to the membrane theory, the 

 variation of polarization in stimulation is the result 

 of a sudden change in those features of structure, comjio- 

 sition, or permeability which determine the normal 

 electromotor properties of the protoi)lasmic surface-film 

 or plasma membrane. Such a change may result from 



^ Sltzimgsber. Ges. Morph. u. Physiol., Munch'-n riSoo-iooo^, 

 Hefte I and 2. 



*See Cremer's exposition in his article in Xagcl's Hatuibuch, p)p. 

 930 ff. 



