44 INDIVIDUALITY IN ORGANISMS 



character of the transmitted changes affecting different 

 regions. The demonstration of such relations would 

 of course complicate our conception of the course of 

 development, but would not necessarily alter our views 

 concerning the fundamental principles of individuation. 

 The problem of the nature of transmitted changes in 

 protoplasm has been the subject of much experiment 

 and discussion and is still by no means solved, but our 

 knowledge concerning them is sufficient to permit us to 

 formulate a working hypothesis of the organic individual 

 in terms of these transmitted changes rather than in 

 terms of transported chemical substances. 



As soon as local differences in chemical constitution 

 of the protoplasm arise, whether they result from differ- 

 ences in metabolic rate or from differences in character 

 of the transmitted change, the relations commonly called 

 chemical correlation, consisting in the production and 

 transportation of different specific substances, begin to 

 play a part, and from this point on these chemical rela- 

 tions are factors of great importance in determining the 

 character of the different parts, until in the adult stage 

 of the highest forms, man and the other mammals, the 

 complexity of chemical correlation is bewildering, as 

 the work of recent years on hormones and internal 

 secretions has clearly demonstrated. From the point of 

 view developed here chemical correlation is, however, 

 a secondary factor, for the underlying order which 

 determines the orderly character of chemical correlation 

 consists in the quantitative gradients which arise in the 

 living mass. 



Since a transmission-decrement in energy or in 

 intensity of the transmitted change exists, the change 



