44 Mr Maclaren 07i Coral Islands and Reefs, as 



ancient lands have sunk under the waves in some parts of the 

 Indian and Pacific Oceans, Mr Darwin thinks that new lands 

 have risen, or are rising, in othei's. The corals t'urnish the 

 evidence of the latter change as well as the former. 



As all corals are formed in the sea, it follows that when we 

 find them in situ on dry land, they afford distinct proof of the 

 land having been upraised. Now, coral banks are found in 

 most of the Sandwich Islands many yards above the sea. In 

 one they form three strata, each 10 feet thick. In Oahu, 

 Mr Pierce, an intelligent European who has lived there six- 

 teen years, is convinced that elevation is at present going on 

 "at a very perceptible rate.'' Elizabeth Island (S. lat. 24, 

 W. long. 129) 80 feet high, is entirely composed of coral. Five 

 of the '-Cook and Austral" islands (S. lat. 20, W. long. 160) are 

 of coral rock. The sixth Mangaia, 300 feet high, is, with the 

 exception of a little basalt, entirely of coral ; and having a flat 

 top with a lagoon-shaped cavity in it, is evidently an upraised 

 atoll. Tongataboo, one of the Friendly Isles, is entirely of 

 coral ; Eoua and Vavao, in this group, the former 200 or 300 

 feet high, are of the same substance. Anamouka, another, 20 

 or 30 feet high, with a salt-water lake in the middle, is, in 

 truth, an atoll, only a very little elevated. Savage Island, 40 

 feet high (south-east of the Friendly group), exhibits tree- 

 shaped corals still unbroken, a proof that its elevation is recent. 

 In the Navigators' group (S. lat. 14, W. long. 170) large frag- 

 ments of coral were found on a steep hill at the height of 80 

 feet, embedded in a base of decomposed lava and sand. On 

 the new Hebrides (S. lat. 18, E. long. 168), coral, seemingly of 

 recent origin, is found at a great altitude. New Ireland (S. 

 lat. 4, E. long. 153), whioh belongs to the Salomon group, pre- 

 sents beds of madreporite rock, with the corals little altered, 

 forming a newer line of coast modelled round an ancient one. 

 In the Mariana group (N. lat. 15, E. long. 146), a succession of 

 cliffs of madreporite limestone present themselves. In the 

 great circular chain of islands extending from the Bay of Bon- 

 gal to Japan, embracing Sumatra, Java, Timor, Coram, the 

 Philippines, and Loo Choo, corals or beds of sea-shells at 

 considei'able heights, afford abundant evidence of elevation ; 

 but for details we refer to Mr Darvvin's book. Where reefs 

 occur on tlio shores of these islands, they are fringing reefs, 



