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Darwin Correspondence Project

From J. D. Hooker   [6 December 1857]1



Dear Darwin

Your DC. results are very curious & suggestive.2 I see no objection to your lumping all the orders (Polygon. Labiatæ, Scrophul. Borrag. together, but not Proteaceæ, or if you do include Proteaceæ it should be also alluded to seperately in a foot note as well, because its distribution is so very local.3

Now with regard to Labiatæ there is a great deal to be said, though perhaps not much that will be satisfactory to you. In the first place it is not only as Natural an Order as any in the Vegetable Kingdom, but one of the largest & best limited & the most equably diffused. & is the best elucidated of any of its size both generically & specifically of any:—about this there are not two opinions amongst Botanists. It therefore forms a formidable obstacle to you & must be studied a little carefully.4

I would strongly wish to see you take more vols of DC., especially Compositæ, Ericeæ & others, for I cannot think that your case will be established upon any but such evidence as is afforded by plants spread over the whole globe— That in small areas, the species of large genera are more variable than of small, may not argue that the same holds good for same genera in large areas5

Such facts as Rubus being variable in Europe & not so in Himalaya prove this— It is also to be remembered that a form marked enough to be ranked as a variety in a local Flora, may not have that value—in a general Flora.

Benthams late researches into the British Flora, have so greatly modified his views of the limits of species, that in my eyes they invalidate the results of local Floras very materially. He has now completed the MSS of his British Flora,6 having studied every species from all parts of the world, & most of them alive in Britain, France & other parts of Europe— Well—he has turned out as great a lumper as I am! & worse.7 Then did you see a paper of Decaisne’s on Pyrus, translated in Gard. Chron about 3 weeks ago8 —in which he adopts Thomsons & my views of species & says that if he had to monograph. Plantago again he would reduce whole sections to one species:—& of course as many species (i.e. marked forms would then rank as varieties.— Now it was Decaisne (a most admirable Botanist) who on receiving the Fl. Indica wrote me most kindly & earnestly begging me to reconsider my mode of viewing species, & hinting that I was going to the devil.— All this does not directly affect your results, but it shows that you should draw them from materials of all kinds—local & general, & from systematists of all shades of opinion. A comparison of Babingtons & Benthams Floras9 will be invaluable: the latter will be out at Easter

I find that Linum Catharcticum has occasionally the upper leaves alternate—:10 normally all are opposite except the upper floriferous, which latter are normally always alternate— I find that in one or two cases an alternate non-floriferous upper pair, which may be theoretically accounted for by the [illeg] of the flower-buds. 11

I send the Cucubalus &c list,12 & will forward the remaining answers soon

Write to Dr. Ferdinand Mueller Govt. Botanist Melbourne Victoria Australia & use your own name—& ours too if you like— he will be tremendously proud to hear from you—is a good active Botanist & will do your behests—13 He is coming home in 1859 so put him up to all you want done toute suite — Also try Chas: Moore Esq Govt. Botanic Garden Sydney—a second-rate man, but quite capable of giving you good information—14 I know of nobody at Cape of Good Hope.

I think the fact of moisture favouring extension of species is a very important one for you

CD annotations

1.3 include … seperately] scored brown crayon
crossed pencil
‘Ch. 7.’15 added pencil
crossed pencil


The date is the Sunday following the letter to J. D. Hooker, 4 December [1857].
In CD’s final tabulation, the orders mentioned are treated separately (see Natural selection, pp. 153–4).
See Natural selection, pp. 155 and 156 n. 1, where CD discussed the case of Labiatae, in which the smaller genera have more varieties than the larger genera, thus constituting one of the orders in which CD’s ‘rule’ did not hold.
See letter to J. D. Hooker, 9 December [1857], for CD’s response to this criticism.
George Bentham’s Handbook of the British flora (Bentham 1858) was published in 1858.
Hooker was known for his tendency to ‘lump’ together plants that other botanists might consider separate species.
The Gardeners’ Chronicle and Agricultural Gazette, 14 November 1857, p. 773, carried a translation of a paper by Joseph Decaisne originally published in the Bulletin de la Société Botanique de France (Decaisne 1857). Decaisne, botanist at the Jardin des plantes, wrote that ‘it would be a great acquisition if describers of plants would condense their species by reducing them to really stable and natural types instead of dividing and multiplying them ad infinitum, as has been the custom for the last 30 years. This opinion is not exclusively my own; it is also that of my excellent friend Dr. J. D. Hooker (Flora Indica, Introductory Essay, &c.)’ (Decaisne 1857, p. 773). The references are to J. D. Hooker and Thomson 1855 and to J. D. Hooker 1853–5.
In October 1857, CD had asked Hooker to investigate this point (see CD note attached to letter to J. D. Hooker, 20 October [1857]). For Hooker’s further comments, see n. 11, below.
On CD’s note questioning Hooker about the leaf arrangement in Linum (see letter to J. D. Hooker, 20 October [1857], CD note), Hooker answered: ‘Upper leaves often so when inflorescence begins. Sometimes without inflorescence ie below inflorescence’. Hooker also drew a diagram to illustrate this point.
This list is probably the one referred to in the letter to George Bentham, 1 December [1857]. It was a list of species that Karl Friedrich von Gärtner considered to be species of the genus Silene that were capable of crossing and generating hybrids (Gärtner 1849, p. 722). CD subsequently extracted a further list of species that Gärtner had hybridised and which he considered were true species of Cucubalus (see letter to George Bentham, 15 December [1857] and letter from George Bentham, [16 or 17 December 1857]). The limits of Silene and Cucubalus were in doubt and CD wanted Bentham’s opinion on the validity of Gärtner’s species.
For CD’s correspondence with Charles Moore, see Correspondence vol. 7, letter from Charles Moore, 11 August 1858. William Jackson Hooker, director of the Royal Botanic Gardens at Kew, had opposed the appointment in 1848 of Moore as director of the moribund botanic gardens in Sydney (Gilbert 1986, p. 72). In 1855, when the Legislative Council of New South Wales was investigating charges of wrong-doing against Moore, William Hooker was alleged to have expressed the view that: ‘Mr Moore is not, in my opinion, a scientific botanist. I have known him for some time; and he is an excellent practical head-gardener, but not a botanist, in the sense in which I understand the term.’ (Gilbert 1986, p. 92).
This refers to chapter 7 of CD’s species book (Natural selection, pp. 279–338). The chapter was entitled ‘Laws of variation: varieties and species compared’.


Babington, Charles Cardale. 1851. Manual of British botany, containing the flowering plants and ferns arranged according to the natural orders. 3d edition. London: John van Voorst.

Bentham, George. 1858. Handbook of the British flora; a description of the flowering plants and ferns indigenous to, or naturalized in, the British Isles. London: Lovell Reeve.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Decaisne, Joseph. 1857. On the development of the floral organs in the pear. Gardeners’ Chronicle and Agricultural Gazette, 14 November 1857, p. 773.

Gärtner, Karl Friedrich von. 1849. Versuche und Beobachtungen über die Bastarderzeugung im Pflanzenreich. Mit Hinweisung auf die ähnlichen Erscheinungen im Thierreiche, ganz umgearbeitete und sehr vermehrte Ausgabe der von der Königlich holländischen Akademie der Wissenschaften. Stuttgart: E. Schweizerbart.

Gilbert, Lionel. 1986. The Royal Botanic Gardens, Sydney. A history, 1816–1985. Melbourne: Oxford University Press.

Hooker, Joseph Dalton. 1853–5. Flora Novæ-Zelandiæ. 2 vols. Pt 2 of The botany of the Antarctic voyage of HM discovery ships Erebus and Terror, in the years 1839–1843, under the command of Captain Sir James Clark Ross. London: Lovell Reeve.

Natural selection: Charles Darwin’s Natural selection: being the second part of his big species book written from 1856 to 1858. Edited by R. C. Stauffer. Cambridge: Cambridge University Press. 1975.


Finds CD’s results [of his survey of well-marked varieties from A. P. and Alphonse de Candolle’s Prodromus systematis naturalis regni vegetabilis (1824–73)] "very curious and suggestive". Thinks the Labiatae will present an obstacle to him as it is a very large and distinct order with well-defined species and genera. Would like to see him tackle more volumes of Candolle’s Prodromus, as his case can only be established by evidence from mundane plants. CD should beware of generalising from local species variability. A comparison of C. C. Babington’s and G. Bentham’s [British] Floras [Babington Manual of British botany (1843, 4th ed., 1856); Bentham Handbook of British flora (1858)] would be invaluable. Suggests CD write to Ferdinand Müller and Charles Moore in Australia. Moisture favouring extension of species is important for CD’s view.

Letter details

Letter no.
Joseph Dalton Hooker
Charles Robert Darwin
Sent from
Source of text
DAR 104: 195–6, DAR 47: 192
Physical description
AL † inc

Please cite as

Darwin Correspondence Project, “Letter no. 2181,” accessed on 12 September 2023,

Also published in The Correspondence of Charles Darwin, vol. 6