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Darwin Correspondence Project

From J. D. Hooker   23 March 1867

Kew

March 23/67.

Dear Darwin

After I had closed my last I remembered that Bentham had to take Naudins letter to Linnean— I enclose it herewith—1 I find figured a very oblong fruited variety of the Chamerops, which lessens the wonder slightly: but I find no description of this oblong variety hitherto. The odd thing of Naudins fruit is that it further tastes like Date. I cannot help suspecting that it will prove fruit of a hybrid, though as you say you have equally curious cases.2 Date & Chamærops belong to same tribe of Palms, though one is Fan-leaved & the other Feather-leaved.3

I see you “smell a rat”, in the matter of insular plants that are related to those of distant continent being common”— Yes, my beloved friend, let me make a clean breast of it.— I only found it out after the Lecture was in print! & by Jingo it has played the very devil with me ever since.4 I have been waiting ever since to “think it out” & write to you about it coherently. I thought it best to squeeze it in, any how or where, rather than leave so curious a fact unnoticed. I am glad you are the only one who has twigged it & it’s importance. I next must work out what proportion of the Trees of these Insular Flora are European, for these non European things are principally trees—that have not been “improved off the face of the Islands”— “more Darwinians” & it is rather a puzzle why trees have not got across, why none of the Cupuliferæ5 are in the Islands. but the whole thing wants working out & it is a good lode to follow, that I shall keep attending to.

Thanks for the better wording of the sentence.6

I like your candid knuckle down about A Gray,7 it “warms my stomach” as they say in the East (or West?) It is like “a drop o’ Gin of a morning”—to me—

A capital French collector is going to the Morocco Mts. (if he can get there) which may throw some light on the Madeiran &c Flora.8

Ever yrs | J D Hooker

[Enclosure]9

Paris,

9 Mars 1867—

Cher Monsieur Hooker,

Je ne saurais vous dire combien votre lettre m’a rendu heureux. Je vous en remercie, ainsi que du charmant portrait que vous avez eu la courtaisie d’y inseré et qui va tenir une place distingué dans ma collection de célébrités contemporaines. Je vous adresse aussi mes félicitations ainsi qu’à Mme Hooker, de l’accroisement de votre famille.10

J’ai beaucoup médité ce que vous me dites, dans votre lettre, de la structure de différentes cucurbitacées. Cette famille contient encore bien des points obscurs, mais qui s’éclaircirsait, je l’espère, quand on pourra les étudier sur des sujets vivantes.

Vous recevrez, en même temps que cette lettre, une petite boîte renfermant des graines de ce que j’appelle provisoirement Microphœnix decipiens. 11 Ces graines, ou plutot ces fruits ressemblent assez à des petites dattes, et peut-ëtre pas sans raison. Leur histoire vous causera, je crois, quelque étonnement.

Ces prétendues dattes soit tout simplement des fruits de Chamærops humilis, var. arborescens, qui ont été fécondés par le pollen du Dattier (Phœnix). L’expérience a été faite à Hyères, par M. Denis,12 grand amateur d’horticulture, qui a quantité de Palmiers adultes dans son jardin. Il y a 2 ans, il a eu l’idée de secouer des régimes mâles de dattier, en fleurs, sur les régimes femelles, pareillement en fleurs, d’un chamærops, et, chose remarquable à noter, les fruits du chamærops ainsi fécondés sont devenus deux fois plus gros que dans les cas de fécondation normale, et sensiblement plus allongés, plus dactyliformes en un mot. J’ai eu soin de faire semer de ces graines à Hyères, l’année dernière (1866), et les jeunes plantes qui en sont sorties donnant des signes très manifestes d’Hybridité, dans la forme de leurs feuilles pennifrondes, et non plus palmatifrondes, comme celles des Chamærops leur mère.

J’ai recommandé à M. Denis de recommencer son expérience en 1866; il l’a fait, et le même phènomène qu’en 1865 a reparu. Au mois de décembre dernier, étant à Hyères, j’ai vu, sur l’arbre, les fruits fécondés par le Dattier— J’en ai pris quelques uns, et je suis heureux de vous en envoyer, pensant qu’il vous sera agréable d’observer un hybride d’un nouveau genre, c’est-à-dire obtenu entre deux plantes de genres très différents, et même classés dans deux sections distinctes par M. de Martius.—13 Ce fait sera modifier la théorie de l’hybridation, telle qu’on su la figure aujourd’hui.

Vous m’intéressez beaucoup, Cher Monsieur Hooker, par ce que vous me dites des effets du froid sur quelques plantes. Je savais le Jubæa très rustique, pourtant je ne l’aurais pas cru capable d’un tour de force comme celui que vous m’apprenez. A Montpellier, il résiste à tout, même à des froids de -12° centigr., sous couverture. Je l’estime du même degré de rusticité que le Cham. humilis, qui vient parfaitement dans toute la région de l’olivier, mais qui ne peut pas en sortir impunément. Le Cham. Fortunei 14 est, à mon avis le plus rustique de tous; il est le seul qu’on réussisse à conserver sans abris à Bordeaux et dans les Landes.

A propos de plantes gelés, il y aurait, Selon moi, une grande réforme à faire dans la météorologie horticole anglaise, et vraiment, cher Monsieur, vous rendriez service à bien du monde en prenant ici l’initiative. Cette réforme consisterait à Substituer le thermomètre centigrade au thermom. de Fahrenheit. Ce dernier est réellement si mal conçu, que ceux même qui ont l’habitude de s’en servir ne réussissent pas toujours à se rendre compréhensibles. J’en trouve à tout instant la preuve dans le Gardener’s Chron. quand je lis les: Effects of the late frosts—The late Winter &c.15 Les horticulteurs n’ayant pas du formule commune pour indiquer le degré de froid dont ils ont à parler, il en résulte une manière arbitraire de s’exprimer, qui fait que très souvent ils ne se comprennent pas les uns les autres. Toutes ces obscurités disparaitraient si ces MM. voulaient adopter le Centigrade, dont le point de départ (le zèro) coïncide avec un phénomène naturel, la température de la glace fondante, la température zèro, qui n’est ni le chaud ni le froid. Rien de plus facile que de se faire comprendre, quand on dit: -6; -2; +3 &c. D’ailleurs ce thermomètre est tout aussi bien milligrade que Centigrade, et même dix milligrade si on veut.

Je serai vraiment heureux de vous revoir, Cher Monsieur;16 nous causerons alors du jardin d’expérimentation qui est en projet. En attendant, agréez l’assurance de mes sentiments les plus sincères et les plus affectueux

votre dévoué confrère   Ch Naudin

Footnotes

See enclosure, and letter from J. D. Hooker, 20 March 1867 and n. 3. Hooker refers to Charles Victor Naudin, George Bentham, and the Linnean Society.
CD had asked Hooker to clarify whether the intermediate fruit that Naudin had sent was from the mother plant (Chamaerops humilis) or the hybrid plant produced by the cross (see letter to J. D. Hooker, 21 March [1867] and n. 4). CD was only interested in the first case, which he interpreted as demonstrating the direct action of the male plant on the female (see letter to J. D. Hooker, 17 March [1867] and n. 3).
Hooker evidently refers to the classification of Phoenix and Chamaerops given in Lindley 1853, p. 139, in which both genera belong to the suborder Corypheae of the order Palmaceae. Later, in Bentham and Hooker 1862–83, 3: 921 and 924, these genera were placed in the tribes Phoeniceae and Corypheae respectively. For the modern classification, see the letter from J. D. Hooker, 14 March 1867, n. 5.
CD had questioned a statement in Hooker’s paper on insular floras (J. D. Hooker 1866a) regarding the commonness of plants having no affinity with those of the ‘mother’ continent (see letters to J. D. Hooker, 17 March [1867] and n. 10, and 21 March [1867], and letter from J. D. Hooker, 20 March 1867).
The Cupuliferae were an order that included the modern families Betulaceae and Fagaceae (see Bentham and Hooker 1862–83, 3: 402–3, and Mabberley 1997).
CD had suggested re-wording a sentence in Hooker’s pamphlet on insular floras, but no new version was ever printed (see letter to J. D. Hooker, 21 March [1867] and n. 3).
In his letter of 21 March [1867], CD admitted he had been mistaken in supposing Asa Gray to be the author of the article ‘Popularizing science’ (Anon. 1867; see letter from J. D. Hooker, 14 March 1867 and n. 1).
The French collector has not been identified. Morocco’s principal mountain ranges include the High Atlas, Middle Atlas, Anti Atlas, and Rif (Columbia gazetteer of the world).
For a translation of the enclosure, see Correspondence vol. 15, Appendix I.
Naudin refers to Frances Harriet Hooker and Reginald Hawthorn Hooker.
The name was later published in Revue Horticole (1885): 513–14.
Alphonse Amaranthe Dugomier Denis. See also letter from J. D. Hooker, 14 March 1867 and n. 7.
Carl Friedrich Phillip von Martius.
Chamaerops fortunei is a synonym of Trachycarpus fortunei.
The winter of 1866 to 1867 was unusually cold. In an editorial in Gardeners’ Chronicle for 26 January 1867 (p. 73), readers were asked to record ‘the results of the recent severe weather’. In the issue for 2 March 1867 (pp. 210–11), several replies were published. Some writers referred to degrees below freezing, others to degrees below zero, and one gave both the temperature and its relation to freezing point (‘10o, or 22o below freezing’; ibid., p. 211).
Hooker was going to Paris to attend the International Horticultural Exhibition (see letter from J. D. Hooker, 14 March 1867 and n. 6).

Bibliography

Columbia gazetteer of the world: The Columbia gazetteer of the world. Edited by Saul B. Cohen. 3 vols. New York: Columbia University Press. 1998.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Lindley, John. 1853. The vegetable kingdom; or, the structure, classification, and uses of plants, illustrated upon the natural system. 3d edition with corrections and additional genera. London: Bradbury & Evans.

Mabberley, David J. 1997. The plant-book. A portable dictionary of the vascular plants. 2d edition. Cambridge: Cambridge University Press.

Translation

From J. D. Hooker   23 March 1867

[Enclosure]1

Paris,

9 March 1867—

Dear Mr Hooker,

I cannot tell you how happy your letter has made me. I thank you for it, as well as the charming portrait which you were so courteous to enclose and which will receive pride of place in my collection of contemporary celebrities. I also send you and Mrs Hooker my congratulations on the addition to your family.2

I have thought a lot about what you told me in your letter of the structure of different cucurbits. There are a number of things that are still obscure about this family, but that will become clearer, I hope, when studied in live specimens.

You will receive, at the same time as this letter, a small box containing seeds of something that I have provisionally named Microphœnix decipiens. 3 These seeds, or rather these fruits, look quite like little dates, and perhaps not without reason. Their story will, I believe, be a source of some astonishment to you.

These apparent dates are quite simply the fruits of Chamærops humilis, var. arborescens, that have been fertilised by the pollen of the date palm (Phœnix). The experiment was made in Hyères, by M. Denis,4 a grand amateur of horticulture, who has a number of adult palms in his garden. Two years ago, he had the idea of shaking bunches of flowering male date palms on bunches of female chæmerops, also in flower, and strange to say, the fruits of chæmerops thus fertilised grew twice as large as in the case of normal fertilisation, and noticably more elongated, in a word, more finger-shaped. I made sure these seeds were sown at Hyères, last year (1866), and the resulting young plants show very clear signs of hybridity in the shape of their leaves, which are pinnate and no longer palmate, like those of the Chæmerops, their female parent.

I advised M. Denis to repeat his experiment in 1866; he did, and the same phenomenon occurred as in 1865. Last December, while at Hyères, I saw on a tree fruits fertilised by the date palm— I took a few of them and I am happy to send them to you, thinking that you would like to observe a new kind of hybrid, that is to say, one from two plants of very different genera and even classified in two distinct sections by Martius.—5 This fact will change the theory of hybridisation as we know it today.

You interest me greatly, dear Mr Hooker, by what you tell me on the effects of cold on certain plants. I knew of the very hardy Jubæa, though I would not have believed it capable of such an amazing feat as that of which you told me. At Montpellier, it tolerates anything, even frosts of -12° centigrade, under cover. I consider it hardy to the same degree as Cham. humilis, which does perfectly well throughout the whole olive-growing region, but can’t tolerate living outside it. Cham. Fortunei 6 is, in my opinion, the hardiest of all; it is the only one that can successfully be kept without cover at Bordeaux and in the Landes.

Regarding frozen plants, In my opinion, there is a great reform needed in English horticultural meteorology, and truly, dear sir, you would do the world a good service by taking the initiative here. This reform would consist in Substituting the centigrade thermometer for the Fahrenheit thermometer. The latter is really so badly designed that even those who are used to using it do not always succeed in making it comprehensible. I find proof of this all the time in Gardener’s Chron. when I read things like: Effects of the late frosts—The late Winter &c.7 Since Horticulturalists don’t have a common formula to indicate the degree of cold they are talking about, the result is an arbitrary manner of expressing themselves, which means that very often they don’t understand each other. All these uncertainties would disappear if these gentlemen would adopt Centigrade, in which the starting point (zero) coincides with a natural phenomenon, the temperature at which ice forms, the temperature zero, which is neither hot nor cold. Nothing is easier than to make oneself understood, when one says: -6; -2; +3 &c. Moreover this thermometer graduates just as well in milligrade as in Centigrade, and even tenths of a milligrade if one wants.

I will be really happy to see you again, dear sir;8 we are now talking about an experimental garden that is being planned. Meanwhile, please accept the expression of my most sincere and affectionate regard

your devoted colleague   Ch Naudin

Footnotes

For a transcription of this enclosure in its original French, see Correspondence vol. 15, pp. 161–2.
Naudin refers to Frances Harriet Hooker and Reginald Hawthorn Hooker.
The name was later published in Revue Horticole (1885): 513–14.
Alphonse Amaranthe Dugomier Denis. See also letter from J. D. Hooker, 14 March 1867 and n. 7.
Carl Friedrich Phillip von Martius.
Chamaerops fortunei is a synonym of Trachycarpus fortunei.
The winter of 1866 to 1867 was unusually cold. In an editorial in Gardeners’ Chronicle for 26 January 1867 (p. 73), readers were asked to record ‘the results of the recent severe weather’. In the issue for 2 March 1867 (pp. 210–11), several replies were published. Some writers referred to degrees below freezing, others to degrees below zero, and one gave both the temperature and its relation to freezing point (‘10o, or 22o below freezing’; ibid., p. 211).
Hooker was going to Paris to attend the International Horticultural Exhibition (see letter from J. D. Hooker, 14 March 1867 and n. 6).

Bibliography

Columbia gazetteer of the world: The Columbia gazetteer of the world. Edited by Saul B. Cohen. 3 vols. New York: Columbia University Press. 1998.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Lindley, John. 1853. The vegetable kingdom; or, the structure, classification, and uses of plants, illustrated upon the natural system. 3d edition with corrections and additional genera. London: Bradbury & Evans.

Mabberley, David J. 1997. The plant-book. A portable dictionary of the vascular plants. 2d edition. Cambridge: Cambridge University Press.

Summary

More on Naudin’s hybrid; the wonder lessened slightly.

JDH’s view that insular plants [distantly] related to those of continents are common came to him only after the lecture was in print; has not yet thought it out fully.

Moroccan flora may throw some light on Madeira flora.

Letter details

Letter no.
DCP-LETT-5456
From
Joseph Dalton Hooker
To
Charles Robert Darwin
Sent from
Kew
Source of text
DAR 102: 151–3; Royal Botanic Gardens, Kew, DC 143: 643
Physical description
5pp

Please cite as

Darwin Correspondence Project, “Letter no. 5456,” accessed on 31 May 2020, https://www.darwinproject.ac.uk/letter/DCP-LETT-5456.xml

Also published in The Correspondence of Charles Darwin, vol. 15

letter