CHANGES IN CORAL-REEFS. 273 



Society Archipelago, on the other hand, where the 

 lagoon channels are almost choked up, where inuch 

 low alluvial land has accumulated, and where, in 

 some cases, long islets have been formed on the 

 barrier-reefs — facts all showing that the islands 

 have not very lately subsided — only feeble shocks 

 are most rarely felt. In these coral formations, 

 whore the land and water seem struggling for mas- 

 tery, it must be ever difficult to decide between 

 the effects of a change in the set of the tides and 

 of a shght subsidence : that many of these reefs 

 and atolls are subject to changes of some kind is 

 certain ; on some atolls the islets appear to have 

 increased gi'eatly within a late period ; on others 

 they have been partially or wholly washed away. 

 The inhabitants of parts of the Maldiva Archipelago 

 know the date of the first formation of some islets ; 

 in other parts, the corals are now flourishing on 

 water-washed reefs, where holes made for graves 

 attest the former existence of inhabited land. It is 

 difficult to believe in frequent changes in the tidal 

 currents of an open ocean ; whereas we have, in 

 the earthquakes recorded by the natives on some 

 atolls, and in the great fissures observed on other 

 atolls, plain evidence of changes and disturbances 

 in progress in the subterranean regions. 



It is evident, on our theory, that coasts merely 

 fringed by reefs cannot have subsided to any per- 

 ceptible amount ; and therefore they must, since 

 the growth of their corals, either have remained 

 stationary or have been upheaved. Now it is re- 

 markable how generally it can be shown, by the 

 presence of vipraised organic remains, that the 

 fringed islands have been elevated ; and so far, 

 this is indirect evidence in favour of our theory. 

 I was particularly struck with this fact, when I 

 found, to mv surprise, that the descriptions given 

 JI. ' 18 



