i go Life and Matter [chap. x. 



of perpetual change, aggregating and re- 

 aggregating in various ways and manifesting 

 ceaseless activities. Such unstable aggre- 

 gates of matter may, like the water of a 

 pond or a heap of organic refuse, serve as 

 the vehicle for influences wholly novel and 

 unexpected. 



Too much agitation that is, too high a 

 temperature will split them up and destroy 

 the new-found potentiality of such aggre- 

 gates ; too little agitation that is, too low 

 a temperature will permit them to begin 

 to cohere and settle down into frozen rigid 

 masses insusceptible of manifold activities. 

 But take them just at the right temperature, 

 when sufficiently complex and sufficiently 

 mobile ; take care of them, so to speak, for 

 the structure may easily be killed ; and 

 what shall we find ? We could not infer or 

 guess what would be the result, but we can 

 observe the result as it is. 



The result is that the complexes group 

 themselves into minute masses visible in the 

 microscope, each mass being called by us a 



