BY E. C. ANDREWS. 169 



Saville Kent* also concurs in Jukes's conclusions as to the origin 

 of the continental shelf and the Barrier Reef as supplied by his 

 (Mr. Jukes's) section. 



Prof. Agassiz, however, claims that the forces of subsidence 

 are unnecessarily called in by these writers, and that the coast 

 (formed of granites and allied rocks) was planed down by the 

 forces of marine erosion, and that coral and other reef-building 

 organisms seized upon " the terraces of erosion " to which the 

 coastal area had been reduced, and in this way by the coalescence 

 of once isolated masses of coral, the Great Barrier Reef was 

 determined in position. 



The following extracts! illustrate the opinions held by Pro- 

 fessor Agassiz and Mr. Jukes as to the origin of the Reef : — 



"While it is undoubtedly true, as mentioned by Kent, that 

 Jukes considered Darwin's hypothesis as ' perfectly satisfactory to 

 my [his] mind,' yet I cannot help analysing Jukes's summary to 

 show how correctly he had analysed the main features of the 

 Great Barrier Reef, and of its relations to the mainland and 

 intervening islands, and was led to what seem to me erroneous 

 conclusions, from the inferences he drew from the diagram he 

 gives of an imaginary section of the Great Barrier Reef, and 

 which I here reproduce, i. 



" It seems strange that Jukes should have given a section across 

 the Great Barrier Reef, and have left out the islands which crop 

 up nearly all along the coast of Queensland between the mainland 

 and the outer or inner line of reefs. This would have given his 

 section an entirely different aspect, as he would have had, 

 cropping up and connected with the line of the mainland, a series 

 of peaks rising from ten to thirty fathoms, round which alone, or 

 round the flat bases of islands and peaks which had disappeared 

 from erosion or other atmospheric causes, corals had grown 

 Such a section is not an imaginary one, for the channels between 



* Saville Kent, The Great Barrier Reef of Australia; London, 1893. 



+ A. Agassiz, "Great Barrier Reef of Australia," pp. 136-139. 



X Voyage of H.M.S. "Fly," Vol. i., p. 333. 



