PHYSIOLOGICAL COROLLARIES OF THE EQUI- 

 LIBRIUM THEORY OF NERVOUS ACTION 

 AND CONTROL. 



By C. L. Herrick. 



Opportunity has afforded incidentally in connection with 

 previous articles in this journal to point out the suggestions 

 from anatomy in favor of a theory of nervous action based on 

 the fundamental conception that the differentia of the various 

 forms of nervous action consist in differences in the form of resist- 

 ance and the reaction thereto, or, in other words, that nerve 

 action partakes of the nature of equilibrium. It may now be 

 permitted to offer fresh illustrations of the application of this 

 principle. In the first place, however, we may note that in no 

 department of physical science is it so plain as in neurology that 

 we are dealing wholly with dynamic elements. While it is true 

 that in the structure of the brain we have to do with morphological 

 details of marvelous complexity and the descriptive side of our 

 work is concerned with the varying outlines, siz^s, and combin- 

 ations of cells, fibres, etc., and the still more recondite struct^ 

 ures within the cell and their dendrites, yet it is always obvious 

 that these morphological peculiarities are but the expressions 

 of inner forces and their responses to others from without. 

 Thus it may even be doubted whether such a body as a centro- 

 some or, at any rate, a centrosphere exists as a material element. 

 Authors have been content to interpret the "asters" as the vis- 

 ual evidence of differential attraction in the cytoplasm. 



It is possible to go farther and admit that all the structures 

 with which the cytologist (and so the physiologist) has to deal 

 are the visual interpretations of dynamic processes. This is 

 more apparent to the neurologist than to the crystallographer 



