Islands," "Proc. R. Soc. Edin." Volume X., page 505, 1880. Prof. Bonney
has given a summary of Sir John Murray's views in Appendix II. of the third
edition of Darwin's "Coral Reefs," 1889.) Before publishing my book, I
thought long over the same view, but only as far as ordinary marine
organisms are concerned, for at that time little was known of the multitude
of minute oceanic organisms. I rejected this view, as from the few
dredgings made in the 'Beagle' in the S. Temperate regions, I concluded
that shells, the smaller corals, etc., etc., decayed and were dissolved
when not protected by the deposition of sediment; and sediment could not
accumulate in the open ocean. Certainly shells, etc., were in several
cases completely rotten, and crumbled into mud between my fingers; but you
will know well whether this is in any degree common. 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. I can, however,
hardly believe, in the former presence of as many banks (there having been
no subsidence) as there are atolls in the great oceans, within a reasonable
depth, on which minute oceanic organisms could have accumulated to the
thickness of many hundred feet. I think that it has been shown that the
oscillations from great waves extend down to a considerable depth, and if
so the oscillating water would tend to lift up (according to an old
doctrine propounded by Playfair) minute particles lying at the bottom, and
allow them to be slowly drifted away from the submarine bank by the
slightest current. Lastly, I cannot understand Mr. Murray, who admits that
small calcareous 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 accumulate
until the bank reaches within the reef-building depth. But I suppose that
I must have misunderstood him.