58 LIFE OF 



have been immense in amount as well as in area, thus to 

 have buried over the broad face of the ocean every one of 

 these mountains above which atolls now stand like monu- 

 ments, marking the place of their former existence." 

 " No more admirable example of scientific method was 

 ever given to the world," says Professor A. Geikie, " and 

 even if he had written nothing else, this treatise alone 

 would have placed Darwin in the very front of investi- 

 gators of nature." 



After thirty-two years' interval, a second edition of 

 " Coral Reefs " appeared, in a cheaper form, in 1874. It 

 is rare indeed for a scientific treatise to attain at once and 

 maintain so long a position of such undisputed authority. 

 The eminent German naturalist, Semper, in 1863, criti- 

 cised the general theory in consequence of his own 

 careful examination of the Pelew Islands; but Darwin 

 easily answered him by pointing to the cumulative evi- 

 dence in favour of his own views. The only really 

 important work on the subject, after Darwin's, was that 

 of Professor J. D. Dana, the eminent American naturalist 

 and geologist, on " Corals and Coral Islands," published 

 in 1872. Darwin, in the preface to his second edition, 

 candidly acknowledged that he had not previously laid 

 sufficient weight on the mean temperature of the sea in 

 determining the distribution of coral reefs ; but this did 

 not touch his main conception. In fact, he maintained 

 his ground undisturbed, and at the same time admired 

 greatly Dana's book, which was the result of personal 

 examination of more coral formations than perhaps any 

 one man had ever studied, and which accepted Darwin's 

 fundamental proposition, that lagoon islands or atolls 



