70 THE DAWN OF LIFE. 



its pseudopods to seize whatever floating particles of 

 food the waters carried over it. There is also reason 

 to believe, from the outline of certain specimens, that it 

 often grew upward in cylindrical or club-shaped forms, 

 and that the broader patches were penetrated by large 

 pits or oscula, admitting the sea-water deeply into the 

 substance of the masses. In this way its growth 

 might be rapid and continuous ; but it does not seem 

 to have possessed the power of growing indefinitely by 

 new and living layers covering those that had died, in 

 the manner of some corals. Its life seems to have had 

 a definite termination, and when that was reached an 

 entirely new colony had to be commenced. In this it 

 had more affinity with the Foraminifera, as we now 

 know them, than with the corals, though practically it 

 had the same power with the coral polyps of accumu- 

 lating limestone in the sea bottom, a power indeed still 

 possessed by its foraminiferal successors. In the 

 case of coral limestones, we know that a large propor- 

 tion of these consist not of continuous reefs but of 

 fragments of coral mixed with other calcareous organ- 

 isms, spread usually by waves and currents in con- 

 tinuous beds over the sea bottom. In like manner we 

 find in the limestones containing Eozoon, layers of frag- 

 mental matter which shows in places the characteristic 

 structures, and which evidently represents the debris 

 swept from the Eozoic masses and reefs by the action of 

 the waves. It is with this fragmental matter that the 

 small rounded organisms already referred to most fre- 

 quently occur; and while they may be distinct 



