47() DAVID H. DOLLEY 



a range of functional phenomena in kind and in degree belonging 

 to a cell as a class so complex and variously differentiated, albeit 

 possessing the common physiological attribute of irritability, 

 may be considered as one unit factor. For the range of functional 

 manifestations must include in the matter of degree not only pure 

 activity but the absence of activity — its diametric opposite — 

 and in the matter of kind everything that is not reproductive 

 or nutritive. Fortunately, this right and basis are characterized 

 by an elemental simplicity when the principles are stated. The 

 mere statement will suffice here as the reasoning and the facts 

 upon which it is based have been developed and presented in 

 detail in previous papers. 



As to degree of intensity, activity and its diametric opposite, 

 depression, are physiologically analyzed by Verworn ('96) as 

 merely quantitative opposites, "activity being an increase, de- 

 pression a decrease in the intensity of vital phenomena." Most 

 beautifully complementary to this are the results of anatomical 

 analysis. In terms of the nucleus-plasma relation, activity is 

 an upset of the relation in favor of the cytoplasm. Depression 

 •is just the opposite, an upset in favor of the nucleus. In other 

 words, the quantitative opposites in Verworn 's physiological 

 sense are just as much quantitative opposites as regards their 

 reciprocal mass relations. However much a condition of life 

 such as heat may change in its range from freezing to overheat, 

 it can and does alter the corresponding reaction only in degree. 



As to the kind of phenomena, the common identity manifested 

 in nucleus-plasma correlation and interchange after all possible 

 stimuli, if adequate, means, if it means anything at all, that all 

 excitant stimuli, namely those inducing pure function, produce 

 an identical reaction. The anatomical unity, not merely of 

 superficial and objective homology, but of measured quantity, 

 is invariable. There is the same identity of anatomical reaction 

 after all depressant stimuli, using the word stimulus always in 

 Verworn's broad sense of any change in the environment. Stimuli 

 can only be excitant or depressant, it making no difference that 

 their reaction may combine first excitation, then later depression. 

 It follows therefore that the singleness, the unity of reaction 



