1 84 RELICS OF PRIMEVAL LIFE 



higher grade can attain. In the case of Eozoon we 

 must imag-ine an ocean floor more uniform and level 

 than that now existing. On this the organism would 

 establish itself in spots and patches. These might 

 finally become confluent over large areas, just as 

 massive corals do. As individual masses attained 

 maturity and died, their pores would be filled up 

 with limestone or silicious deposits, and thus could 

 form a solid basis for new generations, and in this 

 way limestone to an indefinite extent might be pro- 

 duced. Further, wherever such masses were high 

 enough to be attacked by the breakers, or where 

 portions of the sea-bottom were elevated, the more 

 fragile parts of the surface would be broken up 

 and scattered widely in beds of fragments over the 

 bottom of the sea, while here and there beds of mud 

 or sand or of volcanic debris would be deposited over 

 the living or dead organic mass, and would form 

 the layers of gneiss and other schistose rocks inter- 

 stratified with the Laurentian limestone. In this 

 way, in short, Eozoon would perform a function 

 combining that which corals and Foraminifera per- 

 form in the modern seas ; forming both reef lime- 

 stones and extensive chalky beds, and probably 

 living both in the shallow and the deeper parts of 



