. "On the Structure and Origin of Coral Reefs and
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.

Pray forgive me for troubling you at such a 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 marvellous thing
that there should not have been much and long-continued subsiden