The Structure and Distribution of Coral Reefs

Abstract

IN reply to Mr. Guppy's letter permit me to state that (owing to Captain Wharton's kindness) I had before me, when writing, the Report on the Survey of the Tizard and Macclesfield Banks. That reef-building corals occasionally grow at depths considerably greater than 25 fathoms was already known (see “Coral Reefs,” second edition, p. 115, note), and Commander Moore's investigations did not appear to me to do more than confirm this. Mr. Guppy, I think, must have read his copy of the Report rather hastily, or he would hardly have failed to quote the following “suggestive remark” which occurs on p. 16:—“This fact [a living astræan at 45 fathoms] proves that the fine sand of the lagoon is not necessarily fatal to the solid reef-building astræan and helps to explain how individual coral heads appear in the deep waters of these atolls, but it cannot be doubted that their growth is very limited... Coral growth is most luxuriant between 2 and 12 fathoms.”