To Charles Lyell   18 July [1867]

Down. | Bromley. | Kent. S.E.

July 18.

My dear Lyell

Many thanks for yr long letter. I am sorry to hear that you are in despair about yr book; I well know that feeling but am now getting out of the lower depths. I shall be very much pleased if you can make the least use of my present book, & do not care at all whether it is published before yours. Mine will appear towards the end of Nov. of this year; you speak of yours as not coming out till Nov. 68, which I hope may be an error.1 There is nothing in my book about man which can interfere with you;2 so I will order all the completed clean sheets to be sent (& others as soon as ready) to you. But please observe you will not care for the 1st vol., which is a mere record of the amount of variation; but I hope the 2nd will be somewhat more interesting tho’ I fear the whole must be dull.

I rejoice from my heart that you are going to speak out plainly about species.3 My book about Man if published will be short, & a large portion will be devoted to sexual selection, to which subject I alluded in the Origin as bearing on Man.4 Many thanks about 6 fingered men, but that Chapter is finished.5

Tahiti is I believe rightly coloured; for the reefs are so far from the land & the ocean so deep that there must have been subsidence tho’ not very recently: I looked carefully, & there is no evidence of recent elevation.6 I quite agree with you versus Herschel on Volcanic I.s. Wd not the Atlantic & Antarctic volcanos be the best examples for you, as there there can be no coral mud to depress the bottom?7 In my “Volcanic I.” p 126 I just suggest that volcanos may occur so frequently in the oceanic areas, as the surface wd be most likely to crack when first being elevated.8 I find one remark p. 128 which seems to me worth consideration, viz. the parallelism of the lines of eruption in volcanic archipelagoes with the coast-lines of the nearest continent, for this seems to indicate a mechanical, rather than a chemical connection in both cases; ie the lines of disturbance & cracking. In my S. American Geology p. 185 I allude to the remarkable absence, at present of active volcanos on the E. side of the Cordillera in relation to the absence of the sea on this side.9 Yet I must own I have long felt a little sceptical on the proximity of water being the exciting cause. The one volcano in the interior of Asia is said, I think, to be near great lakes; but if lakes are so important why are there not many other volcanos within other continents? I have always felt rather inclined to look at the position of volcanos on the borders of continents, as resulting from coast-lines being the lines of separation between areas of elevation & subsidence. But it is useless in me troubling you with my old speculations.

Rütimeyer sent me his book, but I have not even had time to cut the pages.10

I heartily wish you good progress with your book & remain | Yours affectionately | Ch. Darwin

diagram

LS(A)

Endorsement: ‘1867’

1
For part of Lyell’s letter, see Correspondence vol. 30, Supplement, letter from Charles Lyell, 16 July 1867. Lyell was working on the tenth edition of his Principles of geology (C. Lyell 1867–8); the first volume was published in the first half of December 1866 and the second in the second half of March 1868 (Publishers’ Circular). CD was working on the proof-sheets of Variation, which was published in January 1868 (Freeman 1977).
2
CD had intended to publish a chapter on human descent as part of Variation, but decided to publish it instead as a separate work (see letter to J. D. Hooker, 8 February [1867]).
3
Lyell devoted three largely new chapters, 35 to 37, of Principles of geology to natural selection (C. Lyell 1867–8, 2: 261–328). For CD’s dismay regarding Lyell’s discussion of ‘species’ in Antiquity of man (C. Lyell 1863), see Correspondence vol. 11, letter to Charles Lyell, 6 March [1863].
4
CD’s The descent of man, and selection in relation to sex (Descent) was published in 1871; it was in two volumes. CD’s work on expression of the emotions, which he had intended to form one chapter of his ‘essay on the origin of mankind’ (see letter to Fritz Müller, 22 February [1867]), was published in 1872 (Expression). CD discussed sexual selection briefly in Origin, pp. 87–90. For CD’s growing interest in sexual selection and human descent, see also the letters to A. R. Wallace, 26 February [1867] and [12–17] March [1867].
5
CD discussed polydactylism in chapter 12 of Variation (Variation 2: 12–17).
6
In the map (plate 3) in the front of CD’s Coral reefs, Tahiti is coloured mostly light blue, indicating a barrier reef. Lyell may have queried whether it should not be red, indicating a fringing reef. CD pointed out in Coral reefs that the ‘moat’ between a barrier reef and the land was often filled with detritus and coral forming a type of fringing reef, as was reported to be the case with Tahiti, but he ignored this phenomenon for the purpose of colour-coding the map. Generally speaking, according to CD, barrier reefs occurred in deep water, where subsidence had taken place, and fringing reefs in shallower water, where the sea bed had remained stationary or been uplifted. See Coral reefs, pp. 119–20, 127, 152–3. CD discussed and rejected apparent evidence for the recent elevation of Tahiti in Coral reefs, pp. 138–9. Lyell did not alter his remarks on Tahiti in the tenth edition of Principles of geology (C. Lyell 1867–8, 2: 592), where he mentioned it as an example of a barrier or encircling reef. See also C. Lyell 1867–8, 2: 602–3, on the bearing of CD’s map of coral reefs on zones of subsidence and their coincidence with lack of volcanic activity.
7
John Frederick William Herschel had attempted to account for the proximity of chains of active volcanoes to the sea by suggesting that the carrying of solid matter off the land into the sea by rivers caused pressure on the sea-bed to increase while pressure on the land decreased; he proposed that lava erupted through the cracks where the earth’s crust gave way to the opposing forces (Herschel 1866, pp. 1–46). In C. Lyell 1867–8, 2: 229, Lyell pointed out that active volcanoes rarely occurred near great river deltas, and added: ‘The number, also, of active volcanos in oceanic islands is very great, not only in the Pacific, but equally in the Atlantic, where no load of coral matter or any sedimentary deposits derived from the weight of neighbouring lands can cause a partial weighting and pressing down of a supposed flexible crust.’
8
In Volcanic islands, p. 126, CD asked: ‘Do volcanic eruptions … reach the surface more readily through fissures, formed during the first stages of the conversion of the bed of the ocean into a tract of land?’
9
In South America, p. 185, CD speculated that lava streams had flowed in the eastern Cordillera when the Atlantic reached that far to the west, and pointed out in a footnote the rarity of volcanic action except near the sea or large bodies of water, and the fact that there were now no active volcanoes on the eastern side of the Cordillera.
10
Rütimeyer 1867c.

Manuscript Alterations and Comments

1.7 completed] interl
1.8 & others] interl
3.6 so frequently] interl
3.7 areas,] interl
3.9 in … archipelagoes] interl
3.10 mechanical … chemical 3.11] interl
3.11 ie] above del ‘with’
3.11 & cracking.] interl
3.12 absence,] interl
3.13 absence] above del ‘presence’
3.13 on this side. 3.14] interl
3.14 long] interl
3.18 coast-lines] above del ‘their’

Please cite as “DCP-LETT-5584,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5584