274 The Unity of the Organism 



tive, and so permit indulgence in merely sportive acts," 

 becomes a statement of fact if by "surplus energy" we 

 understand energy available for, and upon occasion used for, 

 acts which are not indispensable to the existence of the in- 

 dividual. 



The quantity and generality of play performed by animals 

 may be taken as one important measure of the extent of the 

 energy possessed over and above what is essential for their 

 normal individual existences, and this without reference to 

 whether or not the play may be useful as a preparation for 

 future essential activities, or for recreation only. The fact 

 can hardly be too much insisted upon that ulterior useful- 

 ness of the organism's acts, whether to the species generally, 

 to offspring, or to the individual's own future, cannot pos- 

 sibly be a sufficient explanation of the energy immediately re- 

 quired for the act itself. Even though an animal does noth- 

 ing whatever except by reason of its hereditary endowments, 

 or in the interest of its offspring; and though the real pur- 

 pose of much that it does looks to its own future, it must 

 nevertheless continue to eat, digest and assimilate, and 

 breathe. The subdivision of biology which has come to be 

 known as physiology has for its distinctive task exactly 

 that of studying the present activities of the organism. With 

 the organism's past, whether individual or racial, and with 

 its future, whether individual or racial, physiology can be 

 concerned only indirectly. 



Summary of Organismal Character of All Subrational 



Psychic Life 



Having now examined broadly though far from exhaus- 

 tively the psychic life of the animal in each of its most ob- 

 vious phases, the highest rational phase, the emotional phase, 

 the instinctive phase, and the reflex phase (in which tropisms 

 are included) for purely descriptive and classificatory pur- 



