THEORIES OF INDIVIDUALITY 29 



problem along somewhat different lines from those 

 already considered. My own investigations in this 

 field, extending over some fifteen years, together with 

 the facts already at hand, as I see them, have forced 

 me to the conclusion that the organic individual is 

 fundamentally neither a structural system, whether 

 physical or "vitalistic" in character, nor a system of 

 chemical reactions, but rather a system of relations 

 between a physical substratum or structure and chemical 

 reactions. These relations, I believe, constitute the 

 fundamental problem of life, so far as it is a biological 

 problem, and as one aspect of it the problem of biological 

 individuality. This is the point of view which underlies 

 the conception of the individual presented in the follow- 

 ing pages. Since the relations between protoplasmic 

 substratum and chemical reactions, whatever their 

 physical or chemical character in particular cases, are 

 essentially dynamic, I have called it a dynamic con- 

 ception. 



A. DYNAMIC CONCEPTION OF THE ORGANIC INDIVIDUAL 



The foundation of unity and order in the organic 

 individual is the transmission of dynamic change, 

 '' stimulus," ''excitation," from one point to another in 

 the protoplasm. In the course of such transmission the 

 transmitted change undergoes a decrement in intensity 

 or energy so that finally at a greater or less distance 

 from its point of origin it becomes inappreciable or 

 ineffective. In the simplest case such a transmitted 

 change originates in a region of high metabolic rate, and 

 transmission occurs to regions of lower rate. The region 

 of high metabolic rate results in the final analysis from 



