DR. MURRAY'S ANTI-SUBSIDENCE THEORY. 83 



estimate, there must still be allowed a sinking of many thousand feet. Moreover, whatever estimate we make that is 

 within probable bounds, we shall not arrive at a more surprising change of level than our continents show that they have 

 undergone ; for since the Tertiary began (or the preceding period, the Cretaceous, closed), more than 10,000 feet have 

 been added to the Rocky Mountains, and parts of the Andes, Alps, and Himalayas. 



"Between the New Hebrides and Australia, the reef and islands mark out another depression, which may have been 

 simultaneously in progress. The long reef of one hundred and fifty miles from the North cape of New Caledonia, and 

 the wide barrier on the west, cannot be explained without supposing a subsidence of one or two thousand feet at the 

 least. The distant barrier of Australia is proof of great subsidence even along the border of that continent. But the 

 greatest amount of sinking took place, in all probability, over the intermediate sea called the ' Coral Sea,' where there 

 is now a considerable number of atolls." 



The testimony and the conclusions elicited and adduced by J. B. Jukes, in his narrative of 

 the surveying voyage of H.M.S. Fly, conducted during the years 1842 and 1846, might 

 be advantageously introduced at this point. Since, however, the evidence in question bears 

 almost exclusively upon the phenomena associated with the Australian Barrier region, it may 

 be more appropriately reserved for consideration when dealing with this specially defined 

 area. 



Evidence has now to be submitted in the order of its chronological incidence, that has 

 the avowed object of demonstrating that Mr. Darwin's subsidence theory cannot be ac- 

 cepted as explaining the normal conditions under which atolls and barrier-reefs are constructed. 

 In fair justice to the originator of, and the participators in this newer "anti-subsidence" 

 theory, it is incumbent that an equal space should be given to the exposition of their 

 views- 



Foremost in the ranks of the several authorities who, on the strength of the further 

 information accumulated within the last two decades, have been unable to accept Mr. Darwin's 

 interpretations, must be mentioned Dr. John Murray, a member of the scientific staff of the 

 Challenger Exploring Expedition, and consequently qualified by a varied acquaintance with 

 corals and coral-reefs to speak from practical experience on this intricate subject. The 

 fullest exposition of Dr. Murray's newer views, embodying his indictment of the subsidence 

 theory, is contained in a paper communicated to the Proceedings of the Royal Society of 

 Edinburgh, Vol X., 1880, and in a lecture on the "Structure, Origin, and Distribution of Coral 

 Reefs," delivered by him at the Royal Institution, March 14, 1888. So excellent an abstract 

 of Dr. Murray's essays appears in Dr. J. G. Bonny's appendix to the latest 1889 edition of 

 Mr. Darwin's treatise that it is herewith reproduced verbatim. To prepare the reader for the 

 new line of argument taken up by this authority, a brief sentence is culled, by way of 

 introduction, from Dr. Murray's London Institution thesis. It begins as follows : — " It seems 

 impossible, with our present knowledge, to admit that atolls or barrier-reefs have ever been 

 developed after the manner indicated by Mr. Darwin." The one word italiciseS in the foregoing 

 sentence has bean purposely annotated by the author : with the object of emphasising 



M 2 



