EXCURSIONS OF AN EVOLUTIONIST 



ica," and the famous essay on " Coral Reefs." 

 In this latter work Mr. Darwin proved that 

 through gradual submergence fringing-reefs are 

 developed into barrier-reefs, and these again into 

 atolls or lagoon-islands ; and thus he not only 

 for the first time rendered comprehensible the 

 work of coral-building, but threw a new and 

 wonderful light upon the movements of eleva- 

 tion and of subsidence in all parts of the globe. 

 By thus bringing the work of the corals into 

 its direct relationship with volcanic phenomena, 

 Mr. Darwin succeeded in presenting "a grand 

 and harmonious picture of the movements which 

 the crust of the earth has undergone within a 

 late period ; " and the result was undoubtedly 

 one of the most brilliant contributions to geology 

 that has been made since the first publication 

 of the great work of Sir Charles Lyell. In 1851 

 53 Mr. Darwin published a " Monograph of 

 the Cirripedia," in two volumes octavo, and ac- 

 companied this, about the same time, with mon- 

 ographs of the various fossil genera of cirripeds 

 (or barnacle family) in Great Britain. In recog- 

 nition of his solid and brilliant achievements, 

 Mr. Darwin in 1853 received the royal medal 

 from the Royal Society, and in 1859 the Wol- 

 laston medal from the Geological Society. By 

 this time his name had come to be known in 

 all parts of the civilized world, and he was al- 

 ready ranked among the foremost living natu- 

 3H 



