XIV 
CONTENTS, 
CHAPTER II. 
BARRIER-REEFS. 
Closely resemble in general form and structure atoll-reefs — Width 
and depth of the lagoon-channels — Breaches through the reef in 
front of valleys, and generally on the leeward side — Checks to 
the filling up of the lagoon-channels — Size and constitution of 
the encircled islands — Number of islands within the same reef — 
Barrier-reefs of New Caledonia and Australia— Position of the 
reef relative to the slope of the adjoining land — Probable great 
thickness of barrier-reefs page 56 to 68 
CHAPTER III. 
FRINGING OR SHORE BEEFS. 
Reefs of Mauritius — Shallow channel within the reef — Its slow 
filling up — Currents of water formed within it — Upraised reefs 
- — Narrow fringing-reefs in deep seas — Reefs on the coast of E. 
Africa and of Brazil — Fringing-reefs in very shallow seas, round 
banks of sediment and on worn-down islands — Fringing-reefs 
affected by currents of the sea — Coral coating the bottom of the 
sea, but not forming reefs 69 to 79 
CHAPTER IV. 
ON THE GROWTH OF CORAL-REEFS. 
SECTION I. ON THE DISTRIBUTION OF CORAL-REEFS, AND ON THE CON- 
DITIONS FAVOURABLE TO THEIR INCREASE . . . 80 to 95 
SECTION n. ON THE RATE OF GROWTH OF CORAL-REEFS . 95 to 108 
SECTION III. ON THE DEPTHS AT WHICH REEF - BUILDING CORALS 
LIVE .......... 108 to 118 
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 subsidence — The effects of storms and earth- 
quakes on atolls — Recent changes in their state — The origin of 
barrier-reefs and of atolls — Their relative forms — The step-formed 
