460 ANNUAL, REPORT SMITHSONIAN INSTITUTION, 1910. 



of the Gulf Stream and West Indian region than of any submarine 

 area of equal extent in the world, and that this knowledge is due to 

 the explorations of the Blake under Alexander Agassiz's scientific 

 direction. It is but just to add that these notable achievements would 

 have been impossible had it not been for the inventive genius and 

 intelligent interest of Capt. Sigsbee in devising sounding apparatus 

 and trawls. 



We now come to the closing period of Alexander Agassiz's scien- 

 tific life — his long years of exploration of the coral reefs of the world, 

 for during the winter of 1885 he visited the Hawaiian Islands, study- 

 ing the reefs of Oahu, Maui, and Hawaii. 



For 25 years this study of the mode of formation of coral islands 

 was to engage his rapt attention, and he was destined to wander far- 

 ther and to see more coral reefs than has any man of science of the 

 present or the past. His boyish joy upon the sight of some rare crea- 

 ture of the sea was something not altogether his own, for he inherited 

 it from his father. The years of toil and care were all forgotten 

 when he drifted in the mirrored waters above the reef and gazed 

 downward into its world of subtle color where contrasts of olives, 

 browns, and greens were accentuated by a butterfly-like flash of bril- 

 liancy as some fish of the coral world glided outward from the depths 

 of the shaded cavern. 



He saw more coral reefs than has any living man, and this very 

 virtue of his exploration is its chief fault, for the study of coral reefs 

 is a complex problem, and it can not be solved by a superficial inspec- 

 tion such as he was forced to make. No one realized this more fully 

 than he did himself, but he believed that the subject should be ap- 

 proached by a superficial survey of all of the reefs of the world, and 

 thus he might hope to discover places wdiere the problem might 

 afterwards be studied with decisive results. He aimed to point out 

 only the broad aspects of the problem, leaving the elucidation of 

 details to those who might follow him. 



I believe that science will come to see that he succeeded in showing 

 that Darwin's simple explanation of the formation of atolls does not 

 hold in any part of the world. Darwin, it will be remembered, as- 

 sumed that wherever we find a volcanic mountain projecting above 

 the sea in the tropical regions corals will grow upon its submerged 

 slopes and form a ring around it. If, then, the mountain slowly sinks 

 beneath the sea, the corals will as constantly grow upward toward the 

 surface, so that after the mountain has disappeared the atoll-ring of 

 coral reefs will still remain. 



Alexander Agassiz maintains, however, that atolls are formed in a 

 variety of ways, and may develop where there has been neither 

 marked elevation nor subsidence in modern times, as at the Great 

 Barrier Reef of Australia, or under stationary conditions after a past 



