388 THE WBENOE AND THE WHITBEB OF MAN 



to two sets of forces — 1, their initial energy and the 

 direction of their aim ; 2, the deflecting power of resist- 

 ing objects or forces — or the different balls might 

 roll with great velocity down a precipitous mountain- 

 side. In the first case velocity and direction of course 

 would be determined largely by initial impulse ; in the 

 second, by the attraction of the earth and by the in- 

 equalities of its surface. 



In evolution, environment, roughly speaking, cor- 

 responds to these deflecting or attracting external 

 objects or forces; inherent tendencies to initial im- 

 pulse. If we lay great weight on initial tendencies, 

 inherent in protoplasm from the very beginning, we 

 shall probably lay less stress on natural selection as a 

 guiding, directing process. 



The great botanist, Nageli, has propounded a most 

 ingenious and elaborate theory of evolution, as de- 

 pendent mainly on inherent initial tendency. "We can 

 notice only one or two of its salient points. All de- 

 velopment is, according to his view, due to a tendency 

 in the primitive living substance toward more com- 

 plete division of labor and greater complexity. This 

 tendency, which he calls progression, or the tendency 

 toward perfection, is the result of the chemical and 

 molecular structure of the formative controlling pro- 

 toplasm (idioplasm) of the body, and is transmitted 

 with other parental traits from generation to genera- 

 tion. And structural complexity thus increases like 

 money at compound interest. Development is a pro- 

 cess of unfolding or of realization of the possibilities 

 of this tendency under the stimulus of surrounding in- 

 fluences. Environment plays an essential part in his 

 system. But only such changes are transmissible to 



