174 
DISTRIBUTION OF CORAL-REEFS. Ch. VI. 
Evidence that many coasts fringed with coral-reefs 
and coloured red, on the map, have been recently ele- 
vated. — As tlie areas which have slowly subsided with- 
in the period of existing corals are many and large, 
we might have expected that such movements would 
have been counterbalanced by the recent elevation of 
other equally large areas ; and this, as we shall see, 
apparently holds good. Corals attached to a rising 
coast would necessarily form a fringing-reef ; and this 
reef would be upraised at each successive elevation, with 
a new one formed on the coast at a lower level. Such 
reefs would differ only by their smaller breadth from 
those attached to a shore which had long remained 
stationary ; for they would not have had sufficient time 
to form a foundation of their own detritus and grow far 
outwards. Fringing-reefs indicate as a general rule 
that the land to wdiich they are attached has not re- 
cently subsided. But they do not tell us whether the 
land is rising or stationary. Nevertheless, the crust 
of the earth seems liable to such incessant changes of 
level that a long-continued stationary condition ap- 
parently is rare. We may infer that this is so from 
the number of cases, within the limits of our map, in 
which upraised corals or other organic remains have 
been found on the shores which are fringed with reefs, 
and are, therefore, coloured red. It may be mentioned 
as bearing on this subject, that I w T as much surprised 
on first reading a memoir on coral formations by 
MM. Quoy and Gaimard , 1 by finding that their de- 
1 Annales des Sciences Nat. tom. vi. p. 279, &c. 
