CORAL REEFS 283 



ute oceanic organisms. I rejected this view as from the 

 few dredgings made in the Beagle iu the South Temper- 

 ate regions, I concluded that shells, the smaller corals, 

 etc., etc., decayed and were dissolved, when not pro- 

 tected by the deposition of sediment; and sediment 

 could not accumulate in the open ocean. ... I have 

 expressly said that a bank at the proper depth would 

 give rise to an atoll, which could not be distinguished 

 from one formed during subsidence. . . . Lastly, I can- 

 not understand Mr. Murray, who admits that small calcare- 

 ous organisms are dissolved by the carbonic acid in the 

 water at great depths, and that coral reefs, etc., etc., 

 are likewise dissolved near the surface, but that this 

 does not occur at intermediate depths, where he believes 

 that the minute oceanic calcareous organisms accumu- 

 late uutil the bank reaches within the reef-building 

 depth. But I suppose that I must have misunderstood 

 him. Pray forgive me for troubling you at such length, 

 but it has occurred to me that you might be disposed to 

 give, after your wide experience, your judgment. If I 

 am wrong, the sooner I am knocked on the head and 

 annihilated, so much the better. It still seems to me a 

 marvelous thing that there should not have been much 

 and long-continued subsidence in the beds of the great 

 oceans." 



Murray at the time does not appear to have made his 

 point clear to either Darwin or Agassiz that the forma- 

 tion of a bank by the deposit of the shells of small pe- 

 lagic animals falling to the bottom, was merely a ques- 

 tion of their accumulating faster than they dissolved. 

 Before reaching great depths, the shells would, in 

 falling slowly through the water, be dissolved faster 



