To J. D. Hooker   3 November [1864]

Down Bromley Kent

Nov. 3d

My dear Hooker

Many thanks for your splendid long letter.1 But first for business.— Please look carefully at enclosed spec. of Dicentra thalictriformis2 & throw away: when plant was young I concluded certainly that tendrils were axial or modified branches, which Mohl says is case with some Fumariaceæ.—3 You looked at them here & agreed.—4 But now plant is old, what I thought was a branch with two leaves & ending in tendril, looks like a gigantic leaf, with 2 compound leaflets & terminal part converted into tendril. For I see buds in fork between supposed branch & main stem.— Pray look carefully, you know I am profoundly ignorant, & save me from a horrid mistake.—5

And now I must say a few words on the several & all interesting points in your letter.

Have you Ch. Martins on Sahara & can you lend it?6

I am quite delighted with what you say about H. Spencer’s book:7 when I finish each number I say to myself what an awfully clever fellow he is, but when I ask myself what I have learnt, it is just nothing. In the last number,, however, he hits a blot in the “Origin”8 but not in my rough M.S. viz no allusion to what the old physiologists call the nisus formativus.—9 I do not admire so much his style, & I think invariably 2 or 3 pages might be condensed into one.—

When I wrote to you I had not read Ramsay,10—how capitally it is written— it seems that there is nothing for style like a man’s dander being put up.— I think I agree largely with you about denudation—but the rocky lake-basin theory is the part which interests me at present.— It seems impossible to know how much to attribute ice,—running water, & sea.— I did not suppose that Ramsay would deny that mountains had been thrown up irregularly & that the depressions would become valleys.— The grandest valleys I ever saw were at Tahiti & here, I do not believe, ice had done anything—anyhow there were no erratics— I said in my S. American Geology that rivers deepen & the sea widens valleys,11 & I am inclined largely to stick to this, adding ice to water.— I am sorry to hear that Tyndall has grown dogmatic.12 H. Wedgwood13 was saying the other day that T.’s writings & speaking gave him the idea of intense conceit; I hope it is not so, for he is a grand man of science.

About the Red Cowslip, I said that it ought not to be called a species, unless it run wild, solely as the most severe test of sufficient constancy of character.—14

When I suggested Wallace for R. medal, I must confess I had obscure glimmering that it wd be difficult to state claims.15 His Amazon Book is nothing;16 his Nat. Selection would, I suppose, rather go against him with Royal Socy.17 I do not know whether his admirable paper before Linn. Socy. is published.18 He wrote one good paper on Geograph. Distribution19 & he has published Geographical papers;20 but I fear it would be impossible yet to make out good case. Talking of Geograph. Distrib. I have had a Prospectus & letter from Andrew Murray, asking me for suggestions!21 I think this almost shows he is not fit for subject, as he gives me no idea what his book will be, excepting that the printed paper shows that all animals & all plants of all groups are to be treated of!! Do you know anything of his knowledge.—

In about a fortnight I shall have finished, except concluding chapter, my Book on “Variation under Domestication”;22 but then I have got to go over the whole again, & this will take me very many months; I am able to work about 2 hours daily.

Thanks about Stanhopea, but I have at last set a capsule:23 my Stanhopeas flowered gorgeously, but I cannot make Acroperas & Gongoras flower, which I much wish for, as I believe Stanhopea has shown me the dodge for Acroperas which formerly so confounded me & John Scott.24 I grieve to hear about Mr M’Nab & him—25

Farewell   forgive this awesomely long letter. Yours affectionately, | C. Darwin

I cannot buy at Veitchs,26 Coryanthes or Cycnoches,27 if you could propagate plants of both, or either, I shd. be pleased,—not that I suppose I shall ever publish my new matter on orchids.—

Endorsement: ‘/64’

2
CD had received seeds of Dicentra thalictrifolia (a synonym of Dactylicapnos scandens) from Hooker in February (see letter from J. D. Hooker, [20 February 1864] and n. 3).
3
CD refers to the description on page 43 of Ueber den Bau und das Winden der Ranken und Schlingpflanzen by Hugo von Mohl (Mohl 1827). An annotated copy of the book is in the Darwin Library–CUL (see Marginalia 1: 590–4).
4
Hooker probably examined the plants on his visit to Down on 24 July 1864. CD asked him to re-identify the plant, which Hooker originally thought to be a form of Corydalis, another genus of the family Fumariaceae (see letter from J. D. Hooker, [20 February 1864] and n. 3).
5
See letter from J. D. Hooker, [23 November 1864]. In ‘Climbing plants’, p. 72, Hooker is cited as confirming that the tendrils of Dicentra thalictrifolia are modified leaves rather than modified branches. CD concluded that in D. thalictrifolia and in three other genera of the family Fumariaceae, one could see the ‘whole gradation’ from leaf-climbers to tendril-bearers (see ‘Climbing plants’, p. 111). See also letter to J. D. Hooker, [27 January 1864] and nn. 19 and 20.
6
In his letter of 26[–8] October 1864, Hooker had recommended Tableau physique du Sahara orientale de la province de Constantine by Charles Frédéric Martins (Martins 1864).
7
See letter from J. D. Hooker, 26[–8] October 1864 and n. 4. The reference is to the first instalments of Herbert Spencer’s Principles of biology (Spencer 1864–7). Spencer’s work was issued in instalments to subscribers beginning in January 1863. See also letter from A. R. Wallace, 2 January 1864 and nn. 20–4, letter from J. D. Hooker, 24 January 1864, and letter from Henry Holland, 4 November [1864].
8
The most recent instalment of Spencer’s Principles of biology, issued in October 1864, discussed CD’s theory of natural selection (see Spencer 1864–7, 1: 445–57). Spencer maintained that CD had not sufficiently recognised the role of functionally acquired modifications in the development of species. Spencer argued that the development of certain morphological structures, such as the large horns of the moose deer and extinct Irish elk, would be useless or detrimental without extensive modifications in the supporting bones, muscles, and ligaments, and without smaller alterations in tissues and organs throughout the body. Such numerous and co-ordinated modifications, Spencer maintained, were extremely unlikely to result from the operation of natural selection on spontaneous variations; in such cases, the principal means of modification was the inheritance of characteristics acquired through the power of use and disuse (ibid., pp. 449–57). CD responded to Spencer’s criticism regarding the Irish elk in Variation 2: 333–5. See also letter from J. D. Hooker, 24 January 1864 and n. 8.
9
CD refers to his manuscript of Variation. In chapter 24, CD discussed the role of ‘nisus formativus’, the term given by physiologists such as Johann Friedrich Blumenbach to the co-ordinating and reparative power in organic beings. The remnant of a form of reproduction in lower organisms, as displayed in fissiparous generation and budding, this power was thought to regulate modifications in higher beings. When, through variation and continued selection, a part or organ had been greatly increased or suppressed, the nisus formativus brought the parts of an organism into harmony (see Variation 2: 293–5, 355). For discussions of nisus formativus in the work of Blumenbach and other German physiologists, see Roe 1981, pp. 116–18, and Lenoir 1982, pp. 20–53.
11
CD had visited the island of Tahiti in 1835 during the voyage of the Beagle. For his remarks on the mountain valleys, see Journal of researches, pp. 485–90. CD discussed the formation of valleys in South America, pp. 67–9.
15
CD had suggested Alfred Russel Wallace as a candidate for the Royal Society of London’s Royal Medal (see letter to J. D. Hooker, 23 September [1864], and letter from J. D. Hooker, [28 September 1864] and n. 6). In his letter of 26[–8] October 1864, Hooker indicated that Wallace lacked sufficient publications for the award.
16
Wallace 1853.
17
Wallace had published several papers on natural selection (see letter from J. D. Hooker, 14 May 1864 and nn. 1 and 3; see also Smith ed. 1991).
18
CD refers to Wallace’s paper on the variation and geographical distribution of the Papilionidae, a family of diurnal butterflies (Wallace 1864a). See letter to A. R. Wallace, 28 [May 1864] and n. 4. The paper was read at the Linnean Society on 17 March 1864, and published in the Society’s Transactions in 1865.
19
CD probably refers to Wallace 1859. An annotated copy of the paper is in CD’s collection of unbound journals at CUL.
20
Wallace’s other geographical papers included Wallace 1863b. An annotated copy is in the Darwin Archive–CUL (DAR 133.10). For a comprehensive bibliography of Wallace’s publications, see Smith ed. 1991.
22
CD had resumed work on the manuscript of Variation in September (see letters to Asa Gray, 13 September [1864] and n. 4, and 29 October [1864] and n. 11). The book was published in January 1868 (Freeman 1977, p. 124).
23
CD had requested pollen masses from the orchid Stanhopea in order to perform pollination experiments; however, all the specimens at Kew had finished flowering (see letter to J. D. Hooker, 22 October [1864], and letter from J. D. Hooker, 26[–8] October 1864).
24
The orchid genera Acropera, Gongora, and Stanhopea posed a difficulty to CD because the structure of the flowers seemed to prohibit pollination (see Orchids, pp. 203–10, and Orchids 2d ed., pp. 166–70). On the efforts of CD and John Scott to explain the pollination of Acropera and allied genera, see the letters from John Scott, 19 March 1864 and nn. 12–18, and 28 March 1864. CD’s experiments with Stanhopea oculata are described in ‘Fertilization of orchids’, p. 153 (Collected papers 2: 150), and Orchids 2d ed., p. 171. CD had carried out experiments with Stanhopea in September; his notes, dated 3–8 September 1864, are in DAR 70: 115–16. See also letter from Hermann Crüger, 21 January 1864 and n. 13.
25
James McNab was John Scott’s immediate supervisor at the Royal Botanic Garden, Edinburgh. See letter from J. D. Hooker, 26[–8] October 1864.
26
James Veitch (1815–69) ran a nursery on King’s Road, Chelsea, London (Post Office London directory 1865).
27
Although CD may have acquired his own Coryanthes specimen (see letter from George Henslow, 7 April 1866 (Calendar no. 5048)), the information he added to publications was based on Crüger 1864 (see letter from Hermann Crüger, 21 January 1864 and n. 3, and letter to Daniel Oliver, 17 February [1864] and n. 11). CD later acquired flowers and flower-buds of Cynoches from Veitch (see ‘Fertilization of orchids’, p. 155 (Collected papers 2: 151–2), and Orchids 2d ed., p. 220).

Manuscript Alterations and Comments

1.2 & throw away] interl
1.3 was] interl
4.4 not] interl
5.3 rocky] interl
5.3 basin] interl
7.4 admirable] interl
7.6 case.] full stop over comma
7.6 Talking] after del ‘for’

Please cite as “DCP-LETT-4650,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-4650