240 GRAND STRATEGY OF EVOLUTION 



offer graded resistance to the passage, or outlet, of 

 nervous impulses. 



I. The Asymmetry of the Outer World. Fully 

 to appreciate the significance of this organic architec- 

 tural system and the way it acts, we must know some- 

 thing of the architectural system of the outer world to 

 which it must, and does, make a profitable response. 



In the outer world of gradient action, all the actors 

 are very unequally and asymmetrically distributed, not 

 only in time, but in the three planes of space. Their 

 ways and means of acting across time and space are 

 very different; their directive influence, and their con- 

 structive power, of very unequal value. Hence, first 

 of all, life must be permanently adjusted, or oriented, 

 to the major directive influences in this outer world of 

 action, and be free to respond to its minor, or more 

 variable influences, good and evil, as they arise. 



The most dominant and constant actors in the outer 

 world are the sun and the earth; one chiefly acting on 

 life by means of gravity, the other by means of light; 

 both agencies are propagated practically instantane- 

 ously, and along essentially radial lines, or lines at 

 right angles to the earth's surface. All the innumer- 

 able other actors, so far as life is concerned, are more 

 variable in power and more intermittent in their ac- 

 tion, and are distributed with great irregularity within 

 the tangential terrestrial plane, between the solid earth 

 and its more fluid envelopes. There they act either 

 directly on life, as physical or material bodies in mo- 

 tion, such as circulating air and water with their trans- 

 ported contents; or as independently moving objects, 

 such as other plants or animals; or they may act indi- 

 rectly on life by means of individually transmitted vi- 



