288 EVOLUTION, GENETICS, AND EUGENICS 



Action ] 



AND > Interaction . 



Reaction I 



Action 



AND 



Reaction 



Functions of the Functions of the Functions of the 



Capture, Storage, Coordination, Balance, Capture, Storage, 



and Release of Cooperation, Compensation, and Release of 



Energy Acceleration, Retardation, Energy 



of Actions and Reactions 



Since it is known that many actions and reactions of the organ- 

 ism — such as those of general and locaUzed growth, of nutrition, of 

 respiration — are coordinated with other actions and reactions through 

 interaction, it is but a step to extend the principle and suppose that 

 all actions and reactions are similarly coordinated; and that while 

 there was an evolution of action and reaction there was also a cor- 

 responding evolution of interaction, for without this the organism 

 would not evolve harmoniously. 



Evidence for such universality of the interaction principle has 

 been accumulating rapidly of late, especially in experimental medicine 

 and in experimental biology. It is a further step in our theory to 

 suppose that the directing power of heredity which regulates the initial 

 and all the subsequent steps of development in action and reaction, 

 gives the orders, hastens development at one point, retards it at 

 another, is an elaboration of the principle of interaction. In lowly 

 organisms like the monads these interactions are very simple; in 

 higher organisms like man these interactions are elaborated through 

 physicochemical and other agents, some of which have already been 

 discovered although doubtless many more await discovery. Thus we 

 conceive of the origin and development of the organism as a con- 

 comitant evolution of the action, reaction, and interaction of energy. 

 Actions and reactions are borrowed from the inorganic world, and 

 elaborated through the production of the new organic chemical 

 compounds; it is the peculiar evolution and elaboration of the physi- 

 cal principle of interaction which distinguishes the living organism. 



Thus the evolution of hfe may be rewritten in terms of invisible 

 energy, as it has long since been written in terms of visible form. All 

 visible tissues, organs, and structures are seen to be the more or less 

 simple or elaborate agents of the different modes of energy. One 

 after another special groups of tissues and organs are created and co- 

 ordinated — organs for the capture of energy from the inorganic environ- 

 ment and from the life environment, organs for the storage of energy, 

 organs for the transformation of energy from the potential state into 





