To J. D. Hooker   [May 1845]¹

My dear Hooker

Every letter of mine to you ought & must begin with thanks for all the trouble you take for me. Imprimis I return all the documents on the Confervoid bodies: when you speak of my Trichodesmium 390, 391 being a “South Sea” species, you are aware that it was collected near the Abrolhos in the Atlantic; in my Journal I refer to another closely allied, rather smaller species seen off C. Leewin in Australia.²

If you find my Journal & can give me the names of any plants, I sh^d be very glad of it: if it be lost I beg you will let me have the pleasure of giving you a copy of the new Edit.

I shall not trouble myself about the Van Diemen’s leaves: & with respect to the Beech leaves, I have already your opinion, & before Christmas, perhaps you w^d have time to look at them once again.

I have had several other communications with Ehrenberg, who has been uncommonly kind & obliging: he finds in the Atlantic dust 67 organic forms; but as none of them are those characteristic of Africa, he is very unwilling to believe it comes from Africa; though as I find the dust always falls with the wind between NE & SE & during the very same months, & only during these months, when the Harmattan from NE & ENE is known to blow clouds of dust from the Sahara, it appears to me absurd to doubt about it.

The loose lichen was lying on the sands of the real deserts of Iquique: Henslow said it was a Cladonia; I suppose he sent it with rest of the Crypt: to Berkeley.— By the way B. says he now thinks the Van Diemen Cyttaria a distinct species.³

I am very much obliged for your sketch of the Galapagos flora; it really turns out a most interesting case: I shall be very anxious to hear the final result, when the Legum: are worked out.— Albemarle differs from the others isl^ds. in having (at least in the parts which we visited) no damp fertile mountain-tops.—

I am glad there are materials for the Botany of Elizabeth isl^d; for it must be an interesting point, as one of the islands, nearest to America, of the not very low Pacific islands.—

I hope you have settled yourself pretty comfortably in Edinburgh, & that you take walks, like a good boy, & do not overwork yourself: I shall be glad to hear how the lectures go on & that you did not find them very terrific: the very thought of such a deed, as lecturing to a whole class, makes me feel awe-struck.

I beg you not to think of writing merely to answer this letter; but if at any time the spirit moves you to give me a little news about yourself, I shall be much pleased.— Depend upon it it is a very easy thing, though never believed till too late, to work the brain too much at the expence of the stomach; I dread the thought of your breaking down in your labours.

Ever my dear Hooker | Most truly yours | C. Darwin

P.S. I suppose I shall not have the Pamphlet &c till your return, & this will do quite equally as well as sooner for me: I sh^d not be surprised, that I have misunderstood you about D’Urville: I have seen the voyage before the very last & I suspect the last one has never been published: I have read the voyage in which he visited Vanikoro & found Peyrouse’s wreck.⁴