WHAT IS EOZOON ? 71 



fmimals, they may also be the fry of Eozoon^ or small 

 portions of its acervuline upper surface floated off in a 

 living state, and possibly capable of living indepen- 

 dently and of founding new colonies. 

 I. It is only by a somewhat wild poetical licence that 

 lozoon has been represented as a " kind of enormous 

 Dmposite animal stretching from the shores of Labrador 

 ) Lake Superior, and thence northward and south- 

 ward to an unknown distance, and forming masses 

 500 feet in depth.'^ We may discuss by-and-by the 

 uestion of the composite nature of masses of Eozoon, 

 nd we see in the corals evidence of the great size to 

 which composite animals of a higher grade can attain. 

 In the case of Eozoon we must imagine 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 

 produced. Further, wherever such masses were high 

 enough to be attacked by the breakers, or where por- 

 tions 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 



