216 CORAL AND ATOLLS 



of the whole to a giant crater is very striking." Even to-day 

 it is held by some that atolls may be formed on ancient 

 craters ; Prof, A. Agassiz says " atolls may also be formed 

 upon the denuded rim of a volcano crater as at Totoya and 

 Thombia in Fiji." ^ These however, must be very special 

 cases and do not justify any general statement. 



It was with the voyage of the Beagle that the era of the 

 specialist zoological traveller dawned, and it was as the result of 

 the visit of her great naturalist to this group in 1836 that 

 modern scientific thought was directed towards the question of 

 the origin of atolls. 



Although it is commonly assumed that Darwin formulated 

 his views of atoll formation as a result of his study of Cocos- 

 Keeling, still he definitely states that " the whole theory was 

 thought out on the We?t Coast of South America, before I had 

 ever seen a coral reef." f Cocos-Keeling was the first atoll 

 that Darwin ever saw, and the only one he ever examined ; 

 and in it he believed he found evidences of those events that 

 he had pictured as constituting the past life of an atoll. To 

 some extent, doubtless, Darwin was influenced by what was 

 told him in the islands, and the whole of this information was 

 certainly not accurate, but the observations made by Darwin 

 are to-day as true as when he recorded them. 



Of Darwin's theory of atoll and reef formation it must be 

 said, that it was a piece of reasoning more masterful than any 

 of its rivals, and more complete in its detail ; but it must 

 also be said that the theory of subsidence when invoked in the 

 formation of the Cocos-Keeling atoll does not meet with any 

 support. The theory of Subsidence must be referred to in 

 some detail ; but it is necessary at once to say that many of 

 the views of Darwin's successors were views that Darwin him- 

 self had originated, and the validity of which he had admitted 

 under certain conditions: in the discussion of the origin of 

 reefs and atolls this fact is often overlooked. 



* See Nature, 1903, p. 547. 



•|- See the Introduction to Charles Darw'n's "Coral Reefs," by J. W. 

 Williams (and other quotations from the same source). 



