THE PRECIPITATION OF CALCIUM CARBONATE IN THE SEA. 523 



The distribution of the bacteria, both as to numbers and species, 

 has been shown to vary at different localities and at different depths, 

 but there are at present too few observations to enable any conclusions 

 or generalizations to be drawn. 



As it at present stands, the investigation can at most be considered 

 to offer a mere indication of the part played by bacterial growth in 

 the metabolism of the sea. To obtain a real insight into the question, 

 it would be necessary to make more extensive bacterial and chemical 

 observations in Tropical, Temperate, and Arctic waters, to study the 

 bacteriology of other areas where Calcium carbonate is being preci- 

 pitated from the sea, and to make further investigations in the Labora- 

 tory into the chemistry of the reactions that can be brought about by 

 various species of marine bacteria. 



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