THE INTERNAL ECONOMY OF THE SEA 



But perhaps the most interesting feature is the 

 circulation of matter, the flux of materials from 

 one embodiment to another, the succession of 

 incarnations, what Sir John Murray, who cL'd so 

 much to make Oceanography a science, called 

 " the never-ending cycle." The Algae find nourish- 

 ment mingled with the water that bathes them, and, 

 using chlorophyll to " conjure with the sunbeams," 

 they build up organic compounds from inorganic 

 constituents. Vegetable proteins are thus formed, 

 and when these are eaten by animals they are raised 

 to a still higher incarnation as animal proteins. But 

 when the plant or animal dies the complex organic 

 substances are broken down, through the agency of 

 bacteria, into simple constituents once more, and 

 some of these being utilized by plants may enter 

 again into the circle of life. Shakespeare, with his 

 prescience, spoke of what might happen to the dust 

 of Csesar, but it was only a vague vision that he can 

 have had of the long nutritive chains, with quaint 

 sequences like those of " The House that Jack 

 built," which connect Diatoms and debris with 

 fishes and man. As Professor Herdman tells us, 

 man eats the cod, which in turn may feed on the 

 whiting, and that on the sprat, and the sprat feeds 

 on Copepods, which again depend on Peridinians and 

 Diatoms. Most of the nutritive chains brings us 

 through Copepods to sea-grass and seaweeds, to 

 Diatoms and debris. For so the world goes round, 

 and such are the incarnations of the sea. 



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