206 Shado wings 



of study. Everybody observes the phenome 

 non; but few persons think about it. Who 

 ever really thinks about it will discover that 

 there is a mystery in it, a mystery which no 

 individual experience can fully explain. 



In any thronged street of a great metropolis 

 thousands of people are constantly turning aside 

 to left or right in order to pass each other. 

 Whenever two persons walking in contrary direc 

 tions come face to face in such a press, one of 

 three things is likely to happen : Either there 

 is a mutual yielding, or one makes room for 

 the other, or else both, in their endeavor to 

 be accommodating, step at once in the same 

 direction, and as quickly repeat the blunder by 

 trying to correct it, and so keep dancing to and 

 fro in each other's way, until the first to per 

 ceive the absurdity of the situation stands still, 

 or until the more irritable actually pushes his 

 vis-a-vis to one side. But these blunders are 

 relatively infrequent': all necessary yielding, as 

 a rule, is done quickly and correctly. 



Of course there must be some general law 

 regulating all this self -displacement, some law 

 in accord with the universal law of motion in 



