Ch. VIII.] 1842—1854. 153 



strikes every reader with astonishmont. It is pleasant, after 

 tho lapse of many years, to recall the delight with which one 

 first read tho Coral Reefs, how one watched the facts being 

 marshalled into their places, nothing being ignored or passed 

 lightly over ; and how, step by step, one was led to the grand 

 conclusion of wide oceanic subsidence. No more admirablo 

 example of scientific method was ever given to the world, and 

 even if he had written nothing else, the treatise alone would 

 havo placed Darwin in the very front of investigators of 

 nature." 



It is interesting to soe in the following extract from one 

 of Lyell's letters * how warmly and readily he embraced tho 

 theory. Tho extract also gives incidentally some idea of tho 

 theory itself. 



" I am very full of Darwin's new theory of Coral Islands, 

 and have urged Whewell to make him read it at our next 

 meeting. I must give up my volcanic crater theory for ever, 

 though it cost me a pang at first, for it accounted for so much, 

 the annular form, the central lagoon, the sudden rising of an 

 isolated mountain in a deep sea ; all went so well with the 

 notion of submerged, crateriform, and conical volcanoes, . . . 

 and then tho fact that in the South Pacific we had scarcely any 

 rocks in the regions of coral islands, save two kinds, coral 

 limestone and volcanic ! Yet in spite of all this, the wholo 

 theory is knocked on the head, and the annular shape and 

 central lagoon have nothing to do with volcanoes, nor even 

 with a crateriform bottom. Perhaps Darwin told you when at 

 the Cape what he considers the truo cause ? Let any mountain 

 be submerged gradually, and coral grow in the sea in which it 

 is sinking, and there will be a ring of coral, and finally only a 

 lagoon in the centre. . . . Coral islands are the last efforts of 

 drowning continents to lift their heads above water. Regions 

 of elevation and subsidence in the ocean may be traced by the 

 state of the coral reefs." 



The second part of the Geology of the Voyage of the Beagle, 

 i.e. the volume on Volcanic Islands, which specially concerns 

 us now, cannot be better described than by again quoting froin 

 Sir A. Geikie (p. 18) :— 



" Full of detailed observations, this work still remains the 

 best authority on the general geological structure of most of 

 the regions it describes. At the time it was written the 

 * crater of elevation theory/ though opposed by Constant 

 Prevost, Scrope, and Lyell, was generally accepted, at least on 



* To Sir John Herschel, May 24, 1837. Life of Sir Charles Lyell, 

 vol. ii. p. 12. 



