CORAL REEFS, AND ISLANDS. 287 



seawards, for this seaward slope is the great growing 

 surface of the reef. The food supply for the masses 

 of living coral, on the outer slope of the reef, is 

 brought by the oceanic currents sweeping past the 

 islands, a fact in relation with the more vigorous 

 growth of the reef on the windward sides. It is 

 maintained by Mr. Murray that the whole of the 

 phenomena of the Tahiti reefs may be fully explained, 

 by reference to the processes at present in action, 

 and without calling in the aid of subsidence, as is 

 done by Darwin and Dana, and, it is argued further, 

 that the form of atoll, and barrier reefs generally, can 

 be explained on the same principles." l 



Having endeavoured, without prejudice, to set 

 forth the theory propounded by Darwin, and sup- 

 ported by Dana, and others, as well as the counter- 

 theory, advanced by Murray, and advocated by the 

 Duke of Argyll, it will be expected of us to impart 

 the result of our own convictions in a few concluding 

 lines. Those who followed the controversy in the 

 pages of Nature, and elsewhere, need not to be 

 reminded that the verdict of just those scientific 

 men who were most capable of judging, was not 

 heard, in condemnation of the hypothesis advanced 



1 " Narrative of the Voyage of the Challenger" vol. i. p. 

 781 (1885) ; also "On the Structure and Origin of Coral Reefs 

 and Islands," by John Murray, in Proc. Roy. Soc. Edin., x. 

 p. 505 (1880). 



