THE AUSTRALIAN GREAT BARRIER REEF. 



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all the soundings inside its outer margin will be obliterated, through the uprising of the 

 land ; the mouths of the big rivers will discharge their water almost directly into the ocean ; 

 and coral-growths will exist under no other conditions than those of a small fringing 

 reef. 



The contention of Mr. Darwin and the supporters of the subsidence theory is that the 

 initial condition of a barrier reef is a fringing reef which, by the slow subsidence of its founda- 

 tion, the upward growth of the coral-masses, and the widening of its lagoon channel, becomes 

 gradually separated from the land, and abuts externally on the deep water of the ocean. At 

 such time as the shores of Tasmania and of Victoria were continuous, and Bass's Strait was 

 a dry highway for the free passage and intermingling of the primitive marsupial populations, 

 the Great Barrier must have been such a relatively insignificant fringing reef, and it must have 

 built up a very considerable proportion of its present mass during the hollowing out of the 

 channels of both the Bass and Torres Straits. 



The foregoing geological evidence being trustworthy and true, the construction of the 

 Great Barrier Reef of Australia under conditions of subsidence, and in accord with the original 

 hypothesis of Mr. Darwin, is proved. Should further geological evidence be desired to prove 

 that the marine areas on the southern and the eastern regions of Australia have undergone a 

 vast movement of subsidence, it is ready to hand. Attention has been drawn by the accom- 

 plished naturalist, Mr. A. R. Wallace, in his well-known works, "The Geographical Distribu- 

 tion of Animals" and "Island Life," to the peculiarities of the New Zealand fauna and flora, 

 which, in a hitherto almost inexplicable manner, indicates a bond of affinity with those of 

 Australia. From the Australian continent, New Zealand is distant no less than 1,200 miles, 

 and for the most part an abyssal ocean intervenes. The most striking affinity is between 

 the wingless or Struthious birds, represented in New Zealand by four living species of Apte- 

 ryx, the kiwis of the natives, and several recently extinct species of Dinornis or Moas. The 

 last-named birds resembled the emeus and cassowaries of Australia, equalling or even excelling 

 them in stature. The skeleton of one species, Dinornis uiaxinnis, contained in the British Natural 

 History Museum, is, in its ordinary standing attitude, eleven feet high. There is abundant 

 evidence of various species of the genus having existed until within a few years before the 

 settlement in New Zealand of Europeans ; this evidence includes the plentiful discovery of 

 their remains in the native cooking places, and also of eggs, in some instances containing 

 portions of the embryos. 



An ingenious and satisfactory interpretation of the seeming anomaly of the near alliances 

 has been advanced by Mr. Wallace in his " Island Life," ed. ii., p. 473. He shows, with 

 the assistance of a map, which he has courteously permitted the author to reproduce, that a 

 distinct, although narrow, bank of soundings, of less than 1,000 fathoms, hereafter referred to 

 as " Wallace's bank," runs up from New Zealand in a north-westerly direction, embracing 



