CHARACTER EVOLUTION 151 



in visible form in fossils. In this field of observation the nature 

 of the chemical and physiological influences of the body can 

 only be inferred, while the relations of these physicochemical 

 influences to those of the chromatin are absolutely unknown. 



Such a form of explanation would, however, only apply to a 

 part of the characters of adaptation (table, page 143). The 

 visible and invisible evolution of the hard parts in adaptation 

 resolves itself into six chief and concurrent processes, namely: 



Ever changing character form and character function, 



Ever changing character velocity, acceleration, balance, re- 

 tardation, in individual development and in the chromatin. 



Ever changing character cooperation, coordination and corre- 

 lation. Characters 



Incessant character origin in the heredity-chromatin, some- I and 

 times following, sometimes antecedent to similar charac- [ Character 

 ter origin in the developing individual. Complexes 



Relatively rapid disappearance of character form and charac- 

 ter function in the developing individual. 



Relatively slow disappearance of the determiners and predis- 

 positions of character form and character function in the 

 heredity-chromatin. 



Changes in the visible bodily hard parts invariably mirror 

 the invisible evolution of the chromatin; in fact, this invisible 

 evolution is nowhere revealed in a more extraordinary manner 

 than in the incessantly changing characters in such structures 

 as the labyrinthine foldings of the deep layers of enamel in the 

 grinding teeth of the horse. 



The chromatin as the potential energy of form and func- 

 tion is at once the most conservative and the most progressive 

 centre of physicochemical evolution; it records the body form 

 of past adaptations, it meets the emergencies of the present 

 through the adaptability to new conditions which it imparts 

 to the organism in its distribution throughout every living cell; 

 it is continuously giving rise to new characters and functions. 



