CONTENTS, ii 



CHAPTER IV. 



ON THE DISTRIBUTION AND GROWTH OF CORAL- 

 REEFS. 



PAGE 



Section I.— On the distribution of coral-reefs, 



AND ON THE CONDITIONS FAVOURABLE TO THEIR 

 INCREASE . . . . '. 83 to 96 



Section II.— On the rate of growth of coral- 

 reefs . . . . . . 96 to 106 



Section III.— On the depths at which reef-build- 

 ing POLYPIFERS CAN LIVE . . . I06 to II4 



CHAPTER V. 



THEORY OF THE FORMATION OF THE DIFFERENT 

 CLASSES OF CORAL-REEFS. 



The atolls of the larger archipelagoes are not formed 

 on submerged craters, or on banks of sediment. — 

 Immense areas interspersed with atolls. — Their sub- 

 sidence. — The effects of storms and earthquakes on 

 atolls. — Recent changes in their state. — The origin of 

 barrier-reefs and of atolls. — Their relative forms. — 

 The step-formed ledges and walls round the shores of 

 some lagoons. — The ring- formed reefs of the Maldiva 

 atolls. — The submerged condition of parts or of the 

 whole of some annular reefs. — The disseverment of 

 large atolls. — The union of atolls by linear reefs. — 

 The Great Chagos Bank. — Objections from the area 

 and amount of subsidence required by the theory, 

 considered. — The probable composition of the lower 

 parts of atolls ..... 11510150 



