CONTENTS 



CHAP. PAGE 



I. The Categories of Life 1 



II. Rhythmic Change in the Sea .... 28 



III. The Factors of Distribution .... 53 



IV. Modes of Nutrition 87 



V. The Sources of Food 118 



Authorities 143 



Index. . . 147 



Frontispiece. Benthos and Nekton; a coral 

 bank in the Red Sea. (From Haeckel.) 



The Tailpieces represent various pieces of 

 oceanographic apparatus pp. 27, 52, 86, 

 117, 142 



