wonderful from the amount of labour which they exhibit, and its extreme
difficulty. I well remember more than forty years ago examining a section
of Silurian limestone containing many corals, and thinking to myself that
it would be for ever impossible to discover whether the ancient corals had
formed atolls or barrier reefs; so you may well believe that your work will
interest me greatly as soon as I can find time to read it. I am much
obliged for your photograph, and from its appearance rejoice to see that
much more good work may be expected from you.

I enclose my own photograph, in case you should like to possess a copy.


LETTER 535. TO A. AGASSIZ.

(535/1. Part of this letter is published in "Life and Letters," III.,
pages 183, 184.)

Down, May 5th, 1881.

It was very good of you to write to me from Tortugas, as I always feel much
interested in hearing what you are about, and in reading your many
discoveries. It is a surprising fact that the peninsula of Florida should
have remained at the same level for the immense period requisite for the
accumulation of so vast a pile of debris. (535/2. Alexander Agassiz
published a paper on "The Tortugas and Florida Reefs" in the "Mem. Amer.
Acad. Arts and Sci." XI., page 107, 1885. See also his "Three Cruises of
the 'Blake,'" Volume I., 1888.)

You will have seen Mr. Murray's views on the formation of atolls and
barrier reefs. (535/3. "On the Structure and Origin of Coral Reefs and