Man^s Place in Nature 221 



way contains the potentiality of all that is to follow 

 — intelligent behavior included, always admitting, 

 of course, that the organism, as it develops, trades 

 with its legacy of talents, using time to gather into 

 itself the influences of environmental nurture. In 

 his science the biologist tries to take the developing 

 egg just for what it seems to him to be — a growing 

 mass of protoplasmic units — self-differentiating, 

 self-regulating, autonomous. He does not use 

 the intelligence of the adult as a factor in em- 

 bryonic development, for he can describe the se- 

 quences without using psychological terms, and 

 he must keep to that method. Yet, for the life of 

 him, he cannot forget that the egg becomes an in- 

 telligent creature, and in his whole thought of the 

 egg he must see it in relation to its end. 



Similarly, the evolutionist describes the history 

 of the race of birds, using a reptilian stock, and long 

 before that a Protist stock as his starting-point. 

 He believes that his beginning in some way in- 

 cludes the potentiality of all that follows, but in 

 his method he tries to take each stage just for what 

 it seems to him to be. He cannot credit the 

 Protists with a central nervous system, though he 

 believes that they have the remote potentiality of 

 it. Yet, for the life of him, he cannot forget that 

 the original Protists must have had in them the 

 promise and potency of all that follows, always re- 

 membering that each stage gathers the results of 



