THE TEEMING LIFE OF THE WATERS 



the water, which becomes cloudy and assumes the hue 

 of the most abundant. Fishermen know the currents 

 thus laden. According to their appearance they call 

 them " thick " waters, or green waters, or blue waters. 

 They are recognised as the promise of an excellent 

 catch, for they contain a great number of fish which 

 settle there and gorge themselves on the abundant 

 accumulation of these little creatures held in suspension. 

 Usually these currents are found only in deep water, 

 as though the shore kept them at a distance; but, 

 sometimes, they approach the coast for a while, and 

 then they offer of their abundance to the fishermen, 

 who are not slow to profit by the opportunity. 



Naturalists, after realising the existence of this float- 

 ing world, have measured it with a view to discover- 

 ing its capacity. The huge figures resulting from their 

 calculations resemble those obtained by astronomers 

 in the stellar world. The infinitely great and the 

 infinitely small here are alike. It has been calculated 

 that a cubic centimetre of sea water may contain 

 several dozens, even several hundreds, of these micro- 

 scopic beings. When we think of the enormous 

 number of cubic centimetres in the ocean the figures 

 become almost staggering. A specialist in this subject 

 found that a portion of the Baltic Sea, measuring 

 superficially a quarter of a square mile, and about sixty- 

 five feet deep, contains a hundred thousand million 

 small Crustacea of the group of Copepods, whose 

 total weight amounts to more than 190 tons. In the 

 North Sea, the same naturalist found that for every 

 square metre of surface, the water contains a mass of 

 microscopic algae, of the order of Diatoms, occupying 

 in all 6570 c.c. and representing thousands of millions 

 of individuals. These Diatoms, held in suspension 

 in the water, serve as food for the Copepods which 

 float like themselves, and these, in their turn, serve as 

 food for the little species of fish which swim among 

 them. The quantity of organic substance represented 



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