THE FOUR COMPLEXES OF ENERGY 21 



fundamental biologic scheme or principle of development may 

 now be restated as follows: 



In each organism the phenomena of life represent the action, 

 reaction, and interaction of Jour complexes of physicochemical 

 energy, namely, those of (i) the Inorganic Environment, (2) the 

 developing Organism {protoplasm and body-chromatin), (3) the 

 germ or Ileredity-chromatin, (4) the Life Environment. Upon 

 the resultant actions, reactions, and interactions of potential and 

 kinetic energy in each organism Selection is constantly operating 

 wherever there is competition witJi the corresponding actions, re- 

 actions, and interactions of other organisms.'^ 



This principle I shall put forth in different aspects as the 

 central thought of these lectures, stating at the outset and 

 often recurring to the admission that it involves several unknown 

 principles and especially the largely hypothetical question 

 whether there is a relation between the action, reaction, and 

 interaction of the internal energies of the germ or heredity- 

 chromatin with the external energies of the inorganic environ- 

 ment, of the developing organism, and of its life environment. 

 In other words, while this is a principle which largely governs 

 the Organism, it remains to be discovered whether it also 

 governs the causes of the Evolution of the Germ. 



As observed in the Preface (p. xvii) we are studying not one 

 but four simultaneous evolutions. Each of these evolutions 

 appears to be almost infinite in itself as soon as we examine 

 it in detail, but of the four that of the germ or heredity- 

 chromatin so far surpasses all the others in complexity that it 

 appears to us infinite. 



The physicochemical relations between these four evolu- 

 tions, including the activities of the single and of the multiply- 

 ing organisms of the Life Environment, may be expressed in 



' Compare Osborn, H. F., 191 7, p. 8. 



