THE OCEAN FEEDING-GROUNDS 89 



At the beginning of the first chapter of this book I 

 gave certain approximate figures relating only to certain 

 units of the planktonic mass. Let us now consider other 

 units. We have seen that the Skagerack, in summer, 

 contains nearly 300,000,000,000 fertile eggs. In the 

 course of February and March the North Sea contains 

 from 65 to 75 trillions of eggs and larvae, and during the 

 spawning season, some 150 trillions of eggs of the 

 herring alone. In the neighbourhood of the Bermudas 

 the mass of living jelly in suspension amounts to 5 cubic 

 centimetres per square metre of oceanic surface. "Off 

 the coast of Iceland and of Newfoundland, where there is 

 a great abundance of fish," says Professor Mangin, " we 

 find 220 cubic centimetres per square metre of surface ; 

 there is thus an enormous quantity of living jelly down 

 to a depth of 50, 100, and 200 fathoms. In another 

 experiment 2 cubic metres of sea-water was filtered ; the 

 residue consisted of 5 millions of peridinaceae, 630,000 

 diatoms, 80,000 copepoda, and 63,000 animals of various 

 species. Let us now consider the waters of a bay 

 notable for its wealth of fish, in the neighbourhood of 

 the Cape of Good Hope. In a column of water i metre 

 square and 18 metres deep, 5^ litres (9-66 pints) of living 

 jelly was found, containing 8,200 millions of bacteria 

 and a vast number of miscellaneous organisms. Stettin 

 Bay, in the Baltic, which is very rich in marine 

 organisms, has yielded in one cubic metre of water 

 9,653,000 filaments of a Cyanophycea, which gave a very 

 characteristic green colour to the water." The variability 

 of plankton is remarkable. In the Baltic, for instance, 

 in the month of April, about 44 millions of organisms 

 were found per square metre of surface ; while in 

 October the number was about 147 millions. The pro- 

 portion varies notably according to the seasons. It 



