THE ORIGIN OF LIFE 257 



solar light for the purpose of decomposing carbonic 

 acid, and forming carbon compounds which had 

 not before existed, and which independently of 

 vegetable life would never have existed. At the 

 same time lime and other mineral substances pre- 

 sent in the sea-water would be fixed in the tissues 

 of these plants, either in a minute state of division, 

 as little grains or Coccoliths, or in more solid 

 masses like those of the Corallines and Nullipores. 

 In this way a beginning of limestone formation 

 might be made, and quantities of carbonaceous and 

 bituminous matter, resulting from the decay of 

 marine plants, might accumulate in the sea-bottom. 

 The plants have collected stores of organic matter, 

 and their minute germs, along with microscopic 

 species, are floating everywhere in the sea. Nay, 

 there may be abundant examples of those Amoeba- 

 like germs of aquatic plants, simulating for a time 

 the life of the animal, and then returning into the 

 circle of vegetable life. In these some might see 

 precursors of the Protozoa, though they are pro- 

 bably rather prophetic analogues than blood re- 

 lations. The plant has fulfilled its function as far 

 as the waters are concerned, and now arises the 

 opportunity for the animal. In what form shall 



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