CHAPTEE XII. 



INDIRECT EQUILIBRATION. 



g 164. Besides those perturbations produced in the moving 



equilibrium of any organism by special disturbing forces, 

 there are ever going on many other perturbations — some 

 which are the still-reverberating effects of disturbing forces 

 previously experienced by the individual, and others which 

 are the still- reverberating effects of disturbing forces expe- 

 rienced by ancestral individuals ; and the multiplied devia- 

 tions of function so caused, imply multiplied deviations of 

 structure. In § 155 there was re-illustrated the truth, set 

 forth at length when treating of Adaptation (§ 69), that an 

 organism in a state of moving equilibrium, cannot have 

 extra function thrown on any organ, and extra growth pro- 

 duced in such organ, without there being entailed correlative 

 changes throughout all other functions, and eventually 

 throughout all other organs. And when treating of Varia- 

 tion (§90), we saw that individuals which have been made, 

 by their different circumstances, to deviate functionally and 

 structurally from the average type in different directions, 

 will bequeath to their joint offspring, compound perturbations 

 of function and compound deviations of structure, endlessly 

 varied in their kinds and amounts. That is to say, besides 

 the primary perturbations and deviations directly caused in 

 organisms by altered actions in their environments, there 

 are ever being indirectly caused, secondaiy and tertiary per- 



