THE EOZOIC AGES. 27 



cherish the expectation that some fortunate discovery 

 may still reveal to us the forms of the vegetation of 

 the Laurentian time. 



It is remarkable that the humbly organized living 

 things which built up the Laurentian limestones have 

 continued to exist unchanged, save in dimensions, up 

 to modern times ; and here and there throughout the 

 geological series we find beds of Foraminiferous lime- 

 stone, similar, except in the species of Foraminifera 

 composing them, to that of the Laurentian. It is 

 true that other kinds of creatures, the coral animals 

 more particularly, have been introduced, and have 

 proved equally efficient builders of limestones; but 

 in the deeper parts of the sea the Foraminifera con- 

 tinue to assert their pre-eminence in this respect, and 

 the dredge reveals in the depths of our modern oceans 

 beds of calcareous matter which may be regarded as 

 identical in origin with the limestones formed in the 

 period which is to us the dawn of organic life. 



Many inquiries suggest themselves to the zoologist 

 in connection with the life of the Laurentian period. 

 Was Eozoon the first creature in which the wondrous 

 forces of animal life were manifested, when, in obe- 

 dience to the Divine fiat, the waters first " swarmed 

 with swarmers," as the terse and expressive language 

 of the Mosaic record phrases it ? If so, in contem- 

 plating this organism we are in the presence of one of 

 the greatest of natural wonders brought nearer than 

 in any other case to the actual workshop of the 

 Almighty Maker. Still we cannot affirm that other 



