ADJUSTMENT, DIRECT AND INDIRECT 



ments now agreed upon, there may be framed 

 an outline of a tolerably complete classification 

 of agencies. Let us reduce to a common form 

 of expression the agencies contemplated in this 

 and in the two preceding chapters. 



Considered in the widest sense, the processes 

 which we have seen to cooperate in the evolution 

 of organisms are all processes of equilibration 

 or adjustment. From the dynamical point of 

 view, as has been shown in previous chapters, 

 an organism is a complex aggregate of matter, 

 in which permanent structural and functional 

 differentiations and integrations are rendered 

 possible by the fact that it continually receives 

 about as much motion as it expends. Now a 

 state in which expended motion is continually 

 supplied from without is called a state o^ de- 

 pendent moving equilibrium. In other words, 

 it is a state in which every change in the dis- 

 tribution of external forces must be met by a 

 change in the distribution of internal forces, in 

 order that the equilibrium may be preserved. 

 This is the case with every organism. Its life 

 is a perpetual balancing of external forces by 

 internal forces. And the complete accomplish- 

 ment of this end requires also that there shall 

 be a continuous internal equilibration, — a per- 

 petual balancing of forces operative in the dif- 

 ferent parts of the organism. Thus the career 



93 



