CHAPTER VII 

 FLOATING CRUSTACEA OF THE OPEN SEA 



IT is only rarely that the floating organisms of the 

 surface of the sea are so large or so abundant 

 as to catch the attention of the casual observer. 

 Except for an occasional shoal of porpoises or of 

 flying-fish, the waste of waters seen from the deck 

 of a ship in mid-ocean usually seems to be barren of 

 life. Nevertheless, there is probably no region of 

 the ocean where the tow-net will not reveal the 

 existence of a more or less varied fauna and flora. 

 Sometimes, indeed, these organisms, though minute, 

 are so numerous as to discolour the water over large 

 areas; whalers in the Arctic seas know by the 

 appearance of " whale-food " where whales are likely 

 to be found, and herring or mackerel fishermen 

 recognize the changes in colour of the water among 

 the " signs " which guide them when and where to 

 shoot their nets. 



The organisms which make up this "pelagic" 

 fauna and flora may be grouped into two classes, 

 which may be termed the " swimmers," or Necton, 



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