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Darwin Correspondence Project

From Alphonse de Candolle1   13 June 1862

Genève

13 Juin 1862.

Mon cher Monsieur

je vous remercie extremement de m’avoir adressé votre article On the dimorphic condition of Primula.2 Il est très curieux et bien propre à faire réflechir, comme tout ce que vous imprimez. J’ai engagé mon fils à en faire un extrait pour la bibliothèque universelle (archives des sciences) et il l’a rédigé effectivement pour un des prochains numéros.3

Le fait principal, celui de la fécondité supérieure, par le croisement des deux formes les moins semblables, ne m’a paru se rattacher en physiologie qu’à un seul fait connu, celui de la fecondité supérieure et des produits plus vigoureux d’individus non parents les uns des autres, tandis que le breeding in and in est défavorable. Cela est bien mystérieux—en théorie on aurait plutot supposé le contraire—mais c’est un fait.

Je n’ai pas vu si vous avez semé les graines obtenues par les divers croisements de vos Primula. On aimerait savoir si les deux formes reparaissent indifferemment des graines de divers croisements, ou si telle catégorie de graines produit une des formes. Vous dites bien que le même pied conserve sa forme de fleurs d’année en année, mais qu’arrive-t-il de génération en génération?

La double forme des Borraginées m’avait frappé en les rédigeant pour le Prodromus.4 Je l’ai constaté dans cet ouvrage pour quelques espèces par ex. l’Alkanna hispidissima DC. Prodr. X p. 94, mais je n’avais point fait les recherches intéressantes que vous avez faites. On a aussi remarqué dans 〈    〉 de la famille des Campanulacées des fleurs tardiv〈es〉 〈    〉 presque nulle, qui sont bien fertiles, et dans 〈    〉 〈  〉munes autant quil m’en souvient deux espèces de fleurs, où les moins po〈  〉 〈    〉 sont les plus fertiles, mais ce ne sont pas des 〈    〉 analogues et l’on n’a pas expérimenté sur les 〈    〉

Aurons-nous bientot le grand ouvrage que vous annonciez comme donnant les preuves detaillées des faits dont vous parlez dans le volume sur l’origine des espèces?5 Je l’attends avec une vive impatience. En somme après vous avoir lu trois ou quatre fois, tantot de suite, tantot partiellement, je suis assez comme Asa Gray.6 J’aime votre théorie. Elle plait à mon esprit. C’est la seule qui rende compte de questions très obscures, inabordables par d’autres voies—mais il lui faudrait des preuves, surtout quant à le natural selection. L’hypothèse générale d’une transmission indéfinie des formes au travers des siècles, avec des modifications plus ou moins graves, semble préférable à toute autre, mais que le natural selection soit le mode, voila ce qui est vague dans mon esprit. Il y a tant de causes qui maintiennent longtemps les mêmes formes de génération en génération ou qui les ramènent! Il est si rare qu’une forme nouvelle paraissant, se conserve sans la protection de l’homme! De ce dernier cas je ne connais aucun exemple constaté. Il y en a probablement, mais pas un seul n’a été prouvé, à ma connaisance. Ces graves questions, sur lesquels vous avez jeté un si grand jour, viennent de m’occuper à l’occasion d’une revue du genre Quercus pour le Prodrome7 et d’une analyse des travaux de Heer sur la Flore tertiaire, que j’ai faite pour la Bibliothèque 〈universelle〉 (Mai 1862).8 J’ai voulu traiter les Quercus 〈    〉 sur l’espèce, au moyen de materiaux 〈    〉t aux formes. Les variations sur la 〈    〉 sont étonnantes. Il en découle une 〈    〉 très grande de prétendues espèces des auteurs. Cela m’a conduit de nouveau à la question des origines des formes. J’ai ri de bon coeur en relisant la définition de Linné (Philos. bot. p. 157): Species tot numeramus, quod diversæ formæ in principio sunt creatæ.9 Combien le bon homme croyait savoir de choses que nous ne savons pas cent ans après! Je n’ai découvert nulle part la date et le lieu précis d’origine d’un millier peut-etre de formes des Quercus que je groupe en 200 espèces environ et que je réduirais encore—si j’avais pour les formes étrangères autant d’échantillons que pour celles d’Europe et des Etats-Unis. Les formes principales du Q. Robur L. (que je considère comme une espèce) sont antérieures à la séparation de l’Irlande d’avec la Grande Bretagne et par consequent de celle-ci d’avec le Continent. Voila bien du temps que les formes pedunculata et sessiliflora luttent dans toutes les forêts de toute l’Europe, sans que l’une chasse l’autre. Les américains sont moins acharnés. Si je me décide à publier ce que j’ai commencé de rediger sur les Quercus j’aurai l’honneur de vous le faire passer.10

L’achevement des Dicotyledones pour le Prodromus m’a occupé depuis quelque temps. J’espère ou plutot je desire avoir assez de force pour reprendre la géographie botanique lorsque j’aurai publié les volumes XV et XVI avec l’aide de divers collaborateurs. Malheuresement pour moi les années avancent et les forces diminuent.

Agréez, mon cher Monsieur, l’assurance de ma haute considération et de tout mon dévouement | Alph. de Candolle

Footnotes

For a translation of this letter, see Correspondence vol. 10, Appendix I.
Candolle’s name is on CD’s presentation list for his paper ‘Dimorphic condition in Primula’ (see Correspondence vol. 10, Appendix III).
C. de Candolle 1862. Candolle refers to his son, Casimir de Candolle.
Candolle and Candolle 1824–73. There is a note, dated 13 June 1862, recording this observation and reference, in DAR 110 (ser. 2): 25a.
Candolle refers to CD’s explanation in Origin, p. 2, that the work was an abstract, without references or authorities. CD stated: ‘No one can feel more sensible than I do of the necessity of hereafter publishing in detail all the facts, with references, on which my conclusions have been grounded; and I hope in a future work to do this.’ The only part of the planned three-part work that was published during CD’s lifetime was Variation (1868).
CD had sent Candolle a copy of Asa Gray’s pamphlet on Origin in which Gray argued that natural selection and natural theology were not inconsistent with one another if one took the view that natural selection operated in accordance with divine purpose (A. Gray 1861; for CD’s presentation list for this pamphlet, see Correspondence vol. 9, Appendix III). In the discussion of CD’s theory given in A. de Candolle 1862b, p. 60 (see n. 10, below), Candolle noted that many apparent anomalies that were repugnant and embarrassing (‘répugnent et embarrassent’) for the theory of special creation (like the rudimentary nipples of male mammals), were, by contrast, brought under a general law by the theory of evolution from a common ancestor. He continued (p. 61): je trouve naturel que des hommes fort éloignés des idées matérialistes, ayant même une tendance prononcée vers d’autres opinions, comme le docteur Hooker, M. Asa Gray et le professeur Heer, préfèrent la théorie de l’évolution et s’attachent plus ou moins aux doctrines ou aux études par lesquelles on s’efforce de la démontrer. [I find it natural that men who distance themselves from materialist ideas, and who may even have a definite tendency towards other opinions, like Dr Hooker, Mr Asa Gray and Professor Heer, prefer the theory of evolution and attach themselves more or less to those doctrines and studies by which attempts are made to demonstrate it.] The references are to Joseph Dalton Hooker and Oswald Heer. On Gray’s response to CD’s theory, see also Dupree 1959.
Candolle and Candolle 1824–73, 16, pt 2: 1–109.
Candolle’s paper (A. de Candolle 1862a) discussed Heer 1855–9 and Heer 1861a.
Linnaeus 1751, aphorism 157: ‘We count as many species as there were forms created in the beginning’ (Stafleu 1971, p. 63).
Candolle published two papers relating to the oak genus (Quercus) in 1862 (A. de Candolle 1862b and 1862c); there are annotated copies of these publications in the Darwin Pamphlet Collection–CUL. The first paper (A. de Candolle 1862c) described a newly identified defining characteristic in acorns, and proposed a new division of the genus. Candolle probably refers to the second paper (A. de Candolle 1862b), entitled ‘Étude sur l’espèce à l’occasion d’une révision de la famille des Cupulifères’ [Study on species occasioned by a revision of the family of Cupuliferae], in which he discussed the grouping and historical origins of the members of the oak family, conluding with an extensive commentary on CD’s theory (A. de Candolle 1862b, pp. 57–68). Although Candolle considered that evolution from a common ancestor was ‘l’hypothèse la plus naturelle’ [the most natural hypothesis] (p. 66), which explained otherwise inexplicable facts, he also observed that there was no direct proof of the theory, and recommended a cautious approach, especially in view of the vast periods of time that would be required to accomplish species change by such a process.

Translation

From Alphonse de Candolle1   13 June 1862

Geneva

13 June 1862.

My dear Sir

I wish to thank you very much for sending me your article On the dimorphic condition of Primula.2 It is very intriguing and rightly gives one cause for reflection, like everything you publish. I have instructed my son to prepare an extract for the Bibliothèque universelle (archives des sciences) and in fact he has edited it for one of the next issues.3

The main fact, that of superior fertility by crossing of the two least similar forms, seems to me to be connected in physiology with only one known fact, that of the higher fertility and more vigorous offspring of individuals not related to each other, while in-breeding is unfavourable. This is quite mysterious—from a theoretical point of view, one would sooner have expected the opposite—but it is a fact.

I have not noted whether you sowed the seeds obtained from the different crossings of your Primula. One would like to know whether the two forms reappear in equal proportions from seeds resulting from different crosses, or whether a given kind of seed produces one form. You are right when you say that the same plant keeps its form of flowers from year to year, but what happens generation after generation?

The double form of the Borraginaceae struck me while I was writing about them for the Prodromus.4 I have noted the fact in this work for certain species, for example Alkanna hispidissima DC. Prodr. X p. 94, but I never carried out such interesting experiments as you did. One should also note in 〈    〉 from the family Campanulaceae late flowers 〈    〉 hardly any, which are quite fertile, and in 〈    〉 as far as I remember two species of flowers, where the least 〈    〉 are the most fertile, but these are not 〈    〉 analogous and no experiments have been performed on the 〈    〉

Will we soon have the great work that you announce as providing detailed evidence of facts mentioned in your book on the origin of species?5 I await it with great impatience. In conclusion, after reading your book three or four times, sometimes entirely, sometimes partially, my view is close to Asa Gray’s.6 I like your theory. It delights my mind. It is the only one that makes sense of very obscure questions, unapproachable by other paths—but we need proofs for it, especially regarding natural selection. The general hypothesis of indefinite transmission across centuries of forms with more or less marked modifications seems preferable to any other, but I am uncertain that natural selection is the means for it. There are so many factors that for a long time keep forms the same from generation to generation or that cause them to revert! It is so rare for a new form to be preserved without the protection of man! I know of no proven instance of the latter case. There are some, probably, but none has been proved, as far as I know. These grave questions on which you have thrown so much light, have been occupying me while preparing a review of the genus Quercus for the Prodromus 7 and an analysis of Heer’s works on the tertiary flora for the Bibliothèque universelle (May 1862).8 My intention was to treat Quercus 〈    〉 on species, by means of materials 〈    〉 of its forms. Variations of the 〈    〉 are astonishing. The result has been a very large 〈    〉 of supposed species by various authors. This has led me again to the question of the origin of forms: I laughed heartily when I reread Linnaeus’s definition (Philos. bot. n. 157): Species tot numeramus, quot diversæ formæ in principio sunt creatæ.9 How much the good man thought he knew about things we do not know a century later! I have nowhere discovered the date and exact place of origin of perhaps a thousand forms of Quercus which I group in about two hundred species and which I would reduce still further, if I could have as many specimens of foreign forms as I have of forms from Europe and the United States. The main forms of Q. Robur L. (which I consider as one species) are prior to the separation of Ireland from Great Britain and consequently of the latter from the Continent. So the pedunculate and sessile forms have been struggling for quite some time in all the forests of Europe without one overthrowing the other. The American ones are less aggressive. If I decide to publish the work I have begun to prepare on Quercus I will have the honour of sending it to you.10

The completion of the Dicotyledons for the Prodromus has occupied me for some time. I hope, or rather, I wish to have sufficient strength to take up botanical geography once again, after publishing volumes XV and XVI with the help of various collaborators. Unfortunately for me the years are advancing and my strength is diminishing.

Please accept, dear Sir, the expression of my high regard and all my devotion. | Alph. de Candolle

Footnotes

For the transcription of this letter in its original French, see pp. 248–50.
Candolle’s name is on CD’s presentation list for his paper ‘Dimorphic condition in Primula’ (see Correspondence vol. 10, Appendix III).
C. de Candolle 1862. Candolle refers to his son, Casimir de Candolle.
Candolle and Candolle 1824–73. There is a note, dated 13 June 1862, recording this observation and reference, in DAR 110 (ser. 2): 25a.
Candolle refers to CD’s explanation in Origin, p. 2, that the work was an abstract, without references or authorities. CD stated: ‘No one can feel more sensible than I do of the necessity of hereafter publishing in detail all the facts, with references, on which my conclusions have been grounded; and I hope in a future work to do this.’ The only part of the planned three-part work that was published during CD’s lifetime was Variation (1868).
CD had sent Candolle a copy of Asa Gray’s pamphlet on Origin in which Gray argued that natural selection and natural theology were not inconsistent with one another if one took the view that natural selection operated in accordance with divine purpose (A. Gray 1861; for CD’s presentation list for this pamphlet, see Correspondence vol. 9, Appendix III). In the discussion of CD’s theory given in A. de Candolle 1862b, p. 60 (see n. 10, below), Candolle noted that many apparent anomalies that were repugnant and embarrassing (‘répugnent et embarrassent’) for the theory of special creation (like the rudimentary nipples of male mammals), were, by contrast, brought under a general law by the theory of evolution from a common ancestor. He continued (p. 61): je trouve naturel que des hommes fort éloignés des idées matérialistes, ayant même une tendance prononcée vers d’autres opinions, comme le docteur Hooker, M. Asa Gray et le professeur Heer, préfèrent la théorie de l’évolution et s’attachent plus ou moins aux doctrines ou aux études par lesquelles on s’efforce de la démontrer. [I find it natural that men who distance themselves from materialist ideas, and who may even have a definite tendency towards other opinions, like Dr Hooker, Mr Asa Gray and Professor Heer, prefer the theory of evolution and attach themselves more or less to those doctrines and studies by which attempts are made to demonstrate it.] The references are to Joseph Dalton Hooker and Oswald Heer. On Gray’s response to CD’s theory, see also Dupree 1959.
Candolle and Candolle 1824–73, 16, pt 2: 1–109.
Candolle’s paper (A. de Candolle 1862a) discussed Heer 1855–9 and Heer 1861a.
Linnaeus 1751, aphorism 157: ‘We count as many species as there were forms created in the beginning’ (Stafleu 1971, p. 63).
Candolle published two papers relating to the oak genus (Quercus) in 1862 (A. de Candolle 1862b and 1862c); there are annotated copies of these publications in the Darwin Pamphlet Collection–CUL. The first paper (A. de Candolle 1862c) described a newly identified defining characteristic in acorns, and proposed a new division of the genus. Candolle probably refers to the second paper (A. de Candolle 1862b), entitled ‘Étude sur l’espèce à l’occasion d’une révision de la famille des Cupulifères’ [Study on species occasioned by a revision of the family of Cupuliferae], in which he discussed the grouping and historical origins of the members of the oak family, conluding with an extensive commentary on CD’s theory (A. de Candolle 1862b, pp. 57–68). Although Candolle considered that evolution from a common ancestor was ‘l’hypothèse la plus naturelle’ [the most natural hypothesis] (p. 66), which explained otherwise inexplicable facts, he also observed that there was no direct proof of the theory, and recommended a cautious approach, especially in view of the vast periods of time that would be required to accomplish species change by such a process.

Summary

Has read the Origin several times. His position is like Asa Gray’s: he wishes to believe in descent, but proofs of natural selection are lacking.

Looks forward to CD’s promised large book.

Thanks for Primula paper [Collected papers 2: 45–63]. Did CD sow the seeds of his crosses? One would like to know whether the two forms reappear at random.

Letter details

Letter no.
DCP-LETT-3603
From
Alphonse de Candolle
To
Charles Robert Darwin
Sent from
Geneva
Source of text
DAR 161.1: 10
Physical description
3pp (French) damaged †

Please cite as

Darwin Correspondence Project, “Letter no. 3603,” accessed on 18 July 2019, https://www.darwinproject.ac.uk/letter/DCP-LETT-3603.xml

Also published in The Correspondence of Charles Darwin, vol. 10

letter