172 INDIVIDUALITY IN ORGANISMS 



this way each level of the gradient develops a character- 

 istic protoplasm and the character of the protoplasm 

 in turn modifies and alters the character of the reactions, 

 and so specific, or what we call qualitative, differences 

 arise, and different specific substances may be produced 

 at different levels of the gradient. At the moment when 

 these specific differences first appear chemical correlation 

 in the commonly accepted sense becomes possible, and 

 from this time on it may play a part in determining the 

 character of further changes at the various levels. After 

 chemical correlation appears it is unquestionably a 

 factor of great importance in determining the character 

 of the various parts and so of the individual as a whole. 

 The point which I wish to emphasize is that chemical 

 or transportative correlation does not and cannot 

 account for the origin of the individual, because the 

 individual must exist as some sort of orderly and definite 

 relation or organization before orderly and definite 

 chemical correlation between its parts is* possible. The 

 dynamic conception of the individual is primarily con- 

 cerned, not with the orderly specificities of chemical 

 correlation, but with the conditions in protoplasm which 

 make those orderly specificities possible. 



The occurrence of transmission in living protoplasm 

 is a familiar fact. The existence of a transmission- 

 decrement and therefore of a limited range of effect- 

 iveness has been demonstrated for the transmission 

 of stimuli in plant tissues and in various animal nerves. 

 In many of the lower animals the range of effectiveness 

 in transmission can readily be observed by means of 

 the range- of reaction to stimuli of different intensity. 

 In transportative correlation a definite range of effective- 



