COSMIC PHILOSOPHY 



existence, and covered with a dense atmosphere, 

 loaded with carbonic acid and aqueous vapour, 

 must have characterized the surface of our 

 planet at this primeval epoch. But as the ever 

 thickening crust slowly collapsed about its con- 

 tracting contents, mountain ridges of consider- 

 able height could be gradually formed, islands 

 could cohere over wider and wider spaces, and 

 deeper basins would permit the accumulation 

 of large bodies of water. Numerous integra- 

 tions of islands into continents, and of lakes 

 into oceans, would thus occur, making the dif- 

 ferentiation of land and sea more distinct and 

 definite. The integration of continents and the 

 rise of mountain chains in different directions 

 must have enlarged the areas of denudation, 

 and thus rendered possible the integration of 

 masses of detritus into extensive sedimentary 

 strata. Differences of watershed or of river- 

 drainage thus caused added variety to the re- 

 sulting geologic formations ; and these, crum- 

 bling into soil of more or less richness, afterward 

 impressed differences upon vegetation, and thus 

 indirectly upon animal life. Yet again, the 

 thickening of the crust must have added to the 

 definite heterogeneity of the surface by its effect 

 upon volcanic phenomena. While the crust 

 was still thin, the angry waves of liquid matter 

 imprisoned beneath must have continually burst 



3i8 



