156 WHAT MAY BE LEARNED FROM EOZOON 



whole. In this matter of aggregation of animals we have thus 

 various grades. The Foraminifers and Sponges present us 

 with the simplest of all, and that which most resembles the 

 aggregation of buds in the plant. The Polyps and complex 

 Bryozoons present a higher and more specialized type; and 

 though the bilateral symmetry which obtains in the higher 

 animals is of a different nature, it still at least reminds us of 

 that multiplication of similar parts which we see in the lower 

 grades of being. It is worthy of notice here that the lower 

 animals which show aggregative tendencies present but im- 

 perfect indications, or none at all, of bilateral symmetry. 

 Their bodies, like those of plants, are for the most part built 

 up around a central axis, or they show tendencies to spiral 

 modes of growth. 



It is this composite sort of life which is connected with the 

 main geological function of the Foraminifer. While active 

 sensation, appetite, and enjoyment pervade the pseudopods 

 and external sarcode of the mass, the hard skeleton common 

 to the whole is growing within ; and in this way the calcareous 

 matter is gradually removed from the sea water, and built up 

 in solid reefs, or in piles of loose foraminiferal shells. Thus 

 it is the aggregative or common life, alike in Foraminifers as 

 in Corals, that tends most powerfully to the accumulation of 

 calcareous matter; and those creatures whose life is of this 

 complex character are best suited to be world builders, since 

 the result of their growth is not merely a cemetery of their 

 osseous remains, but a huge communistic edifice, to which 

 multitudes of lives have contributed, and in which successive 

 generations take up their abode on the remains of their an- 

 cestors. This process, so potent in the progress of the earth's 

 geological history, began, as far as we know, with Eozoon. 



Whether, then, in questioning our proto-foraminifer, we have 

 reference to the vital functions of its gelatinous sarcode, to the 

 complexity and beauty of its calcareous test, or to its capacity 



