My dear Lyell

Many thanks for your kind note.— I will send for the Scotsman.¹ D^r. Holland thinks he has found out, what is the matter with me, & now hopes he shall be able to set me going again.—² Is it not mortifying it is now nine weeks, since I have done a whole day’s work, & not more than four half days.— But I wont grumble, any more, though it is hard work to prevent doing so.— Since receiving your note, I have read over my chapter on Coral,³ & I find I am prepared to stand by almost everything.— it is much more cautiously & accurately written, than I thought. I had set my heart upon having my volume⁴ completed before your new edition,⁵ but not, you may believe me, for you to notice anything new in it (for there is very little besides details) but you are the one man in Europe, whose opinion of the general truth of a longish argument I should be always most anxious to hear.—

My M.S. is in such confusion, otherwise I am sure you should most willingly, if it had been worth your while, looked at any part you chose.—

I will briefly notice, two or three points, which will be different in my volume.— Although I believe that coral-reefs do not exist at greater depth than 20 fathoms (mentioned incidentally at p. 558, Journal) in the open oceans, it appears, contrary to what Ehrenberg has said, that in the Red Sea there are beds of coral in 25 fathoms.—⁶ The argument drawn from the fact of coral-reefs not existing at great,⁷ that there must have been subsidence in the large areas, scattered with reefs, stands firm, even should coral-reefs be hereafter found to live at much greater depths that I suppose; for I find the areas are immense in which every island is low, & of coral-formation.

My classification of reefs is somewhat modified viz

(1) Lagoon islands (or atolls, as I mean always to call them). to avoid the word lagoon, which refers only to the interior lake.

(2).‘Encircling reefs’,—of which the ‘Barrier” reefs are a mere modification & not a separate class as I have made them in my Journal

(3). Fringing reefs.

(4). Irregular reefs, springing up from shoal water, & fringing banks of sediment.—

Lastly.— I shall have only very slightly to modify my general conclusions. (p. 567 Journal).— it will chiefly consist in speaking rather less positively—& using the words alternate areas more frequently than “parallel bands” I shall not be able to throw any light on distribution of organic forms in the Pacific as I had hoped p. 568.—

I hope these remarks may be worth your reading— I send them, as other wise my conscience would not have been easing.— If I am able, I certainly will come on Saturday & will let you know in time, if I find I am too unwell—

Yours, C. D.—