lo THE ORIGIN AND EVOLUTION OF LIFE 



may also exclude as unscientific the vitalistic theory of an 

 entelechy or any other form of internal perfecting agency dis- 

 tinct from known or unknown physicochemical energies. 



Since certain forms of adaptation which were formerly 

 mysterious can now be explained without the assumption of 

 an entelechy we are encouraged to hope that all forms may 

 be thus explained. The fact that the causes underlying the 

 origin of many forms of adaptation are still unknown, uncon- 

 ceived, and perhaps inconceivable, does not inhibit our opinion 

 that adaptation will prove to be a continuation of the previous 

 cosmic order rather than the introduction of a new order of 

 things. If, however, we reject the vitalistic hypotheses of the 

 ancient Greeks, and the modern vitalism of Driesch, of Bergson, 

 and of others, we are driven back to the necessity of further 

 experiment, observation, and research, guided by the imagina- 

 tion and checked by verification. As indicated in our Pref- 

 ace, the old paths of research have led nowhere, and the 

 question arises: What lines shall new researches and experi- 

 ments follow? 



The Energy Concept of Life 



While we owe to matter and form the revelation of the 

 existence of the great law of evolution, we must reverse our 

 thought in the search for causes and take steps toward an 

 energy conception of the origin of life and an energy conception 

 of the nature of heredity. 



So far as the creative power of energy is concerned, we 

 are on sure ground: in physics energy controls matter and 

 form; in physiology function controls the organ; in animal 

 mechanics motion controls and, in a sense, creates the form of 

 muscles and bones. In every instance some kind of energy 



