462 THE EVOLUTION 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 \ve 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 priori, therefore, we 

 may be certain that all processes of modification which do 



