230 W. M. Davis — Shaler Memorial Study of Coral Reefs. 



ing submarine foundations rising from a fixed ocean bottom, 

 as Murray supposed, is beyond direct proof without the aid of 

 numerous expensive borings; but the facts that barrier-reef 

 islands everywhere show signs of submergence, and that many 

 fringing reefs, barrier reefs and atolls have been elevated, 

 strongly suggest that the ocean bottom is not fixed, and that 

 still-standing foundations must be of rare or impossible occur- 

 rence. 



It is not a little interesting to learn that — exception being 

 made of work very lately published — the only observers of 

 coral reefs who have applied Dana's principle regarding the 

 embayment of dissected coasts to the coral-reef problem in the 

 Pacific are Australasians, a fact to which 1 had the pleasure of 

 calling attention at the Sydney meeting of the British Associa- 

 tion in August, 1914. E. C. Andrews was in 1902* the first 

 to adduce the embayment of the Queensland coast in evidence 

 of recent submergence, one consequence of which he saw to be 

 the upgrowth of the Great Barrier reef ; C. Hedley and T. G. 

 Taylorf followed with additional details a few years later, and 

 P. Marshall made a more general application of the same argu- 

 ment in 19124 In 1914 T - w - Vaughan§ stated that recent 

 submergence, indicated by embayed shorelines, is characteristic 

 of several West Indian islands, more or less encircled by bar- 

 rier reefs : this is the most general statement of the kind that I 

 have found concerning Atlantic reefs. 



Out-growing Reefs on still-standing Islands. — Before con- 

 sidering the theories of the second group, it is desirable to 

 state more directly the chief reasons against two theories of 

 the first group which have gained prominence within the last 

 three decades. The theory that explains barrier reefs as the 

 result of outgrowth of fringing reefs on their own advancing 

 talus, while the lagoon behind them is excavated by solution 

 around the still-standing central island, has since 1880 received 

 widespread attention, because it was then announced by an 

 oceanographer of so wide experience as Sir John Murray. It 

 is significant that Murray had been, a few years before as a 

 member of the " Challenger " staff, on the wonderfully embayed 

 island of Kandavu in the Fiji group, and that the Narrative 

 Report, to which he presumably contributed, made no special 

 mention of the embayments and no mention whatever of their 



* Preliminary Note on the Geology of the Queensland Coast ; Proc. Linn. 

 Soc. N. S. W., xxvii, 146-185, 1902; see p. 183. 



+ Coral Eeefs of the Great Barrier, Queensland; Prcc. Austral. Assoc. 

 Adv. Sci., ii, 397-413, 1908. 



% Oceania, pp. 7, 30, in Vol. vii, Abt. 1, Heft 5. of Steinmann and Wilck- 

 ens Handbuch der regionalen Geologie, Heidelberg, 1912. 



i? The platforms of barrier reefs, Bull. Amer. Geogr. Soc, xliv, 1914, 426- 

 429. 



