EARTH-LIFEGENERATION. 395 



added that the preceding process of Assim- 

 ilation, in which each side assimilates the 

 other, depends upon the present process of 

 Generation, as the inorganic and organic 

 forms have to be generated before they can 

 be assimilated. Earth-life therefore has 

 these two strands, ever active and inter-active. 



The process of inorganic Generation re- 

 sults from two kinds of rocks in geologic 

 language the primary and secondary rocks. 

 The former are the original constituents of 

 the Earth cooled and crystallized, hence desig- 

 nated as igneous, unstratified, without fossil 

 or organic remains. The secondary rocks are 

 the derived, resulting from the destruction 

 of the original rocks and their reconstruction 

 through water (aqueous rocks), or through 

 the atmospheric agencies (sub-aerial rocks), 

 or through organisms, vegetal and animal. 

 The last give the fossiliferous rocks, which 

 being also stratified in succession of time, re- 

 veal the past history of Earth-life along three 

 lines plant, animal, mineral. Herewith we 

 are enabled to reach back and take up the en- 

 tire sweep of Earth-life in its generative 

 movement. 



3. Total Generation of Earth-life. Thus 

 the organic sta.2:e of Earth-life has its dis- 

 tinct history divided into numerous epochs 

 and sub-epochs, in triple record, from the be- 



