The Origin of Organic Forms. 195 



molar and molecular motion, and thus try to elude 

 the grip of Newton ; if so, we should not care to 

 follow him into the imperceptible. 



Searching for a safe starting point anywhere, from 

 which we may advance along the line of causal 

 activity to the results before us, we go back, finding 

 no resting place till we reach the atom and its en- 

 vironment. Each instance of composition of atoms, 

 and further composition of molecules of greater com- 

 plexity, and so onward to the physiological unit, is to 

 be explained if explicable by the equilibration of 

 the constituent parts and the incident forces. We 

 are, then, driven in the last resort to assume, as exis- 

 tent in the original atom and the force immanent in 

 it, or impelling it, the primal source of that power of 

 direction supposed to be inherent in the physiological 

 units. The gleam of light which seemed to break 

 upon us leads us into the darkness of the incompre- 

 hensible, and is dispersed in the atomic whirl. Emerg- 

 ing out of this dim region, we are directed to turn our 

 eyes towards the environment, and seek in it the 

 source of the impelling power which produces the 

 continuous development. Mr. Spencer cites an ex- 

 ample. "During its earlier stages every embryo is 

 sexless becomes either male or female as the balance 

 of forces acting on it determines. Each advance in 

 embryonic complication results from the action of 

 the incident forces on the complication previously 

 existing. Indeed the now accepted doctrine of epi- 



