1907] Jennings.— Behavior of the Starfish. 179 



After we have assumed the existence of a non-physico-chemical 

 entity whose essence it is to control the physico-chemical process in 

 the way required to bring about harmonious, "specific and typi- 

 cal" action, it is difficult to see why the processes should some- 

 times not progress harmoniously, or why all should be in harmon}^ 

 but certain ones. On the other hand, if we hold that this har- 

 mony is a secondary result of the operation of many factors 

 whose co-operation is the result of a development, then this occa- 

 sional imperfection is just what we should expect. 



While the experiments on habit formation show that the har- 

 monious impulse is subject to development in the history of the 

 individual, I would, of course, not by any means maintain that 

 this accounts in full for the unity of the impulse. There is, in 

 addition, the histor}^ of the ' ' germ plavSm " to be considered ; much 

 has come to the individual thi-ough heredity. How these hered- 

 itary properties have been acquired we do not know ; here is a 

 problem for analytical experimentation for coming generations of 

 investigators. 



Imperfect Solution of the Problem on Purely Physiological 

 Grounds. — The physiological formulation then leaves the problem 

 in this condition : (1) The impulse is not always perfect and con- 

 cordant, indicating that it is not the reflection of a perfect and 

 concordant entity, but is a product of development; (2) the de- 

 velopment of the harmonious impulse can be traced partly to in- 

 dividual history, in the process of habit-formation, and many of 

 the factors on which it depends can be set forth, though this does 

 not account for the whole; (3) in addition to the individual de- 

 velopment, there is racial development, whose laws we have as yet 

 made little progress in tracing. The unsolved part of the prob- 

 lem (confessedly a large part) lies in this field of the laws of 

 racial development ; a solution will not come until these laws are 

 worked out. 



The EntelecJiy Doctrine a Roiunciatioji of all Solution. — It is 

 to meet the difficulty for which we have appealed to the study of 

 the laws of racial development that Driesch assumes the existence 

 of the Entelechy. It is probable that investigators would be as 

 read,y to accept the entelechy doctrine as any other scientific ex- 

 planation, provided that they could see that it is an explanation. 



