462 THE EVOLUTIO]^ OF LIFE. 



among all its members, one is better adapted than the rest to 

 take advantage of some before-unused agency in the environ- 

 ment, is to say that its moving equilibrium is, in so far^ more 

 stably adjusted with respect to the aggregate of surrounding 

 influences. And if, as a consequence, this individual main- 

 tains its moving equilibrium when others fail to do so, and 

 produces offspring which do the like — that is, if individuals 

 thus characterized multiply and supplant the rest ; there is 

 evidently, as before, a process by which an equilibration be- 

 tween the organism and its environment is effected, not im- 

 mediately but mediately, through the continuous intercourse 

 between the species as a whole and the environment. 



§ 168. Thus we see that indirect equilibration does what- 

 ever direct equilibration cannot do. It is scarcely possible 

 too much to emphasize the conclusion, that all these processes 

 by which organisms are re-fitted to their ever-changing 

 environments, must be equilibrations of one kind or other. 

 As authority for this conclusion, we have not simply the 

 universal truth that change of every order is towards equi- 

 librium ; but we have also the truth which holds throughout 

 the organic world, that life itself is the maintenance of amoving 

 equilibrium between inner and outer actions — the continuous 

 adjustment of internal relations to external relations ; or the 

 maintenance of a correspondence between the forces to which 

 an organism is subject and the forces which it evolves. For 

 if the preservation of life is the preservation of such a moving 

 equilibrium, it becomes a corollary that those changes which 

 enable a species to live under altered conditions, are changes 

 towards equilibrium with the altered conditions. 



Hence, all such changes being equilibrations, their differ- 

 ences can be nothing but differences in the ways through 

 which they result. If they are not effected immediately, 

 they must be effected mediately. A prio7n, therefore, we 

 may be certain that all processes of modification which do 



