CHAPTER VI 

 THE EVOLUTION OF THE EARTH 1 



IN treating of Evolution in general, it was 

 shown how organic bodies are, by a pecu- 

 liar concurrence of conditions, enabled to 

 lock up a great deal of motion within a small 

 compass, so that permanent redistributions of 

 structure and function can be effected. From 

 the decisiveness with which this peculiar advan- 

 tage possessed by organic bodies was indicated, 

 it might have been surmised that in the case of 

 inorganic aggregates an attempt to trace the 

 secondary phenomena of differentiation and in- 

 tegration would prove illusory,, owing to the 

 absence of this concurrence of conditions. In 

 many inorganic bodies it is true that there does 

 not go on to any notable extent that secondary 

 redistribution which results in increase of hete- 

 rogeneity. The evolution of a cloud, a rock, 

 or a crystal, is little more than an integration 

 of matter attended by dissipation of motion. 

 In the evolution of the solar system, on the 

 other hand, we have witnessed an increase in 

 heterogeneity, definiteness, and coherence that 



1 [See Introduction, § 17.] 

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