CHAPTER XIII. 



HUMAN POPULATION IN THE FUTURE. 



§ 371. Any further evolution in the most-highly evolved 

 of terrestrial beings, Man, must be of the same nature as 

 evolution in general. Structurally considered, it may consist 

 in greater integration, or greater differentiation, or both — 

 augmented bulk, or increased heterogeneity and definiteness, 

 or a combination of the two. Functionally considered, it 

 may consist in a larger sum of actions, or more multiplied 

 varieties of actions, or both — a larger amount of sensible and 

 insensible motion generated, or motions more numerous in 

 their kinds and more intricate and exact in their co-ordina- 

 tions, or motions that are greater alike in quantity, com- 

 plexity, and precision. 



Expressing the change in terms of that more special 

 evolution displayed by organisms; we may say that it must 

 be one which further adapts the moving equilibrium of 

 organic actions. As was pointed out in First Principles, 

 § 173, "the maintenance of such a moving equilibrium, re- 

 quires the habitual genesis of internal forces corresponding 

 in number, directions, and amounts to the external incident 

 forces — as many inner functions, single or combined, as there 

 are single or combined outer actions to be met." And it 

 was also pointed out that " the structural complexity accom- 

 panying functional equilibration, is definable as one in which 

 there are as many specialized parts as are capable, separately 

 and jointly, of counteracting the separate and joint forces 

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