ATOLL AND REEF FORMATION 225 



The fact of the cutting down of land below the level of the 

 sea by currents has been called into question by geologists.* 

 Admiral Sir W. L. Wharton has given instances in which 

 the process has been carried out. Graham's Island in the 

 Mediterranean is a notable example of this ; but it must be 

 remembered that the destruction of a loosely piled volcanic 

 structure, cast up to-day and washed away to-morrow, is a 

 very different thing to the removal of an oceanic island girt 

 about by a barrier reef 



Professor Alexander Agassiz has also added the testimony 

 of his great experience in favour of this method of preparation 

 of the submarine base. In a paper read before the Royal 

 Society in 1903, he says : "Denudation and submarine erosion 

 fully account for the formation of platforms." Agassiz also 

 demands a rising, rather than a sinking, of the areas over 

 which coral formations are found, and in the same paper he 

 says : " Throughout the Pacific and Indian Oceans, and the 

 West Indies, the most positive evidence exists of a moderate 

 recent elevation of coral reefs." 



Dr. H. B. Guppy is another believer in the theories of 

 Murray ; he brought his views forward in a paper published 

 in the Proceedings of the Royal Society of Edinhurgh in July 

 1886. The paper was the outcome of his investigations in the 

 Solomon Islands, and in addition to finding confirmation of 

 Murray's views, he also postulated a movement of elevation. 

 Dr. Guppy doubted the power of coral growth to raise a reef 

 to a greater height than some five fathoms below the surface, 

 and, at p. 367, he speaks of "the inability of detached sub- 

 merged reefs to raise themselves within the constructive power 

 of the breakers without the assistance of a movement of 

 elevation." 



When in 1888 Dr. Guppy came to examine the atoll of 

 Cocos-Keeling his views, at any rate with regard to the 

 imjportance of the effects of " solution," seem to have slightly 

 changed. In his account of the atoll {op. cit. p. 578) he says: 

 " I do not, however, consider this [solution] as a very effectual 

 * See Mr. Ernest Schwarz, Nature, 1904, p. 581. 



P 



