From Alphonse de Candolle¹ 2 July 1868

Genève

2 Juillet 1868.

A Mons^r Ch. Darwin

Mon cher Monsieur

Comme je vous le disais il y a trois mois j’ai emporté votre ouvrage aux bains de Schinznach, où il a été ma seule et très interessante lecture.² J’y ai trouvé beaucoup d’instruction et de sujets de réflexions. La futur ouvrage sur les espèces spontanées, aura cependant plus intéret pour moi et je me réjouis extremement de le voir. Si ce n’est pas indiscret je vous demanderai de me dire si vous en avez avancé la rédaction et quand on peut espérer de la voir paraitre.³ Selon votre reponse je serai plus ou moins disposé à m’occuper de certaines questions dont vous parlerez probablement et sur les quelles votre opinion, une fois connue, influera necessairement.

En vous lisant j’ai noté quelques reflexions. Les voici, sans ordre, sans élaboration spéciale. Si vous faites de nouvelles éditions il est possible que telle ou telle idée, tel ou tel fait, vous soient de quelque utilité.

Vous n’avez pas eu connaissance des mémoires du D^r Sagot, un medecin francais qui a pratiqué à Cayenne et qui est maintenant professeur d’hist. nat. dans l’établissement impérial de Cluny. Il a dabord publié 2 articles sur les légumes des pays tempérés cultivés dans les régions equatoriales (Bull. soc. imp. d’horticulture 1860, et Bull. de la Soc. botan. de France, 1862), et ensuitte il a réuni beaucoup d’observations sur les deux règnes, dans l’opuscule: De l’etat sauvage et des Resultats de la culture et de la domestication, in-8^o, Nantes 1865. Vous y verriez des faits interessants. Si vous ne pouvez pas obtenir cet ouvrage par les libraires, je puis écrire à l’auteur.⁴

Comme exemples de la ténacité de caractères peu importants je puis citer les tentatives infructueuses des Vilmorin (grand père et fils) pour obtenir un Robinia pseudo-acacia sans épines, propre à la nourriture des chevaux, et une betterave très sucrée. Ils ont semé pendant plusieurs générations des Robinia 1^o non épineux, 2^o en prenant les moins épineux de ceux qui naissaient, et ils ne sont pas parvenus à avoir moins d’épines. Notez quil s’agit ici d’aiguillons, c.a.d. d’endurcissements superficiels et irréguliers de l’ecorce non de véritables épines, soit rameaux ou feuilles ou stipules endurcies. Quant à la betterave ils ont imaginé une sonde pour extraire des morceaux de la racine et vérifier la dose de sucre. Ils ont ensuite pris des graines sur les pieds les plus sucrés et ainsi de suite de 2 en 2 ans, mais ils n’ont pas pu obtenir une race suffisament constante pour être mise dans le commerce.⁵ Un fabricant de sucre de betterave, qui achete chez eux, me l’a confirmé. Il m’a appris que la dose du sucre dépend beaucoup des terrains.

Je connais particulierement bien une famille dans la quelle depuis plusieurs générations les individus possèdent dans les muscles de la peau du cuir chevelu, en dessus de la tête, une force et une mobilité singulières. L’un d’eux, quand il etait au collège, faisait le pari que si on placait sur le sommet de sa tête plusieurs gros dictionnaires, il les jeterait à bas sans remuer le moins du monde la tête, seulement en mouvant d’arriere en avant le cuir chevelu. Il ne manquait jamais. Ensuite un camarade appuyait ses mains de toutes ses forces sur sa tête et ne pouvait pas l’empecher de remuer la partie comprimée. Or le grand père de cet individu, son père et son oncle (les seuls de leur génération) et ses trois enfants (une fille et 2 fils) avaient ou ont exactement la même faculté. Je ne puis pas parler encore de la 5^ème génération, parceque les enfants sont trop jeunes, mais voici qui est plus curieux. Cette famille est originaire de Provence. Elle s’est divisée en deux branches, l’une à Genève, l’autre encore demeurée en France. On a demandé au chef de cette dernière, cousin au 17^ème degré de celui dont je parlais dabord, s’il pouvait remuer ainsi le cuir chevelu. Il a montré quil le pouvait. Entre les deux il y avait 8 générations, l’auteur commun et 8 autres générations, total 17 degrés. Je vous affirme ces details pour les avoir vérifiés moi-même et si je vous nommais la famille vous comprendriez que je ne puis pas me tromper. Voila un caractère bien acccessoire et bien inutile à ceux qui le possedent! Chez les sauvages du nord de l’Amérique il aurait peut-être empêché d’etre scalpé, à cause de la terreur quil aurait causée, mais en Europe je ne pense pas qu’on en ait jamais profité. Ce n’est pas l’usage qui a augmenté la mobilité. Probablement ce caractère est moins rare chez les peuples meridionaux, très mimiques, et comme la famille en question etait designée comme noble, près de Marseille, deja en 1184, il est vraissemblable quelle est de souche grecque ou latine. Elle aurait conservé en Suisse depuis 3 siècles un caractère héréditaire fort inutile.⁶

Les raies (stripes) qui reviennent souvent sur les chevaux hybrides, m’ont rappelé que dans les armoiries une barre ou raie est le signe de batardise.⁷ Est-ce que peut- être les anciens chevaliers avaient eu l’idée de ce signe pour avoir observé les chevaux, quils devaient assurement bien connaitre?

Vol. 2 p. 17. Je ne suis pas surpris que des enfants issus de cousins germains aient été albinos.⁸ Cette affection est un signe de faiblesse.

Un medecin francais qui parait avoir conservé le goût des livres latins me disait dernierement que Tacite, en parlant des Germains, dit quils avaient des bœufs sans cornes.⁹ Je n’ai pas eu le loisir de vérifier.

La taille des animaux depend beaucoup de l’espace qu’ils peuvent parcourir. On sait combien les chevaux de certaines îles (Corse, Shetland etc) sont petits. J’ai transporté une fois de très petits poissons rouges (poisson doré, de la Chine) d’une petite piece d’eau de chez mon voisin, dans mon étang de $\frac{1}{5}$ d’acre. Ils ont beaucoup grossé et leurs successeurs ont été tous plus gros. La nourriture était la même, car c’est l’eau de chez moi qui coule chez le voisin. Ces poissons ont été ensuite détruits. On a curé l’etang et j’ai acheté d’un autre endroit 34 poissons rouges de grosseur moyenne, tels qu’on les a ordinairement dans les bocaux. Comme il n’y avait pas d’autres poissons ils ont vite multiplié et se sont fixés à environ 1500 à 2000. Leur taille est supérieure à ceux achetés, et un marchand au quel j’en offrais, m’a dit qu’on les trouverait trop gros pour les aquariums— Quand il y a une couche épaisse de glace ces poissons se tiennent au fond de l’eau, rangés parallélement.¹⁰

Vol. 2 p. 313. Je suis de ceux qui ont traité l’acclimatation de chimère, mais je parlais de l’adaptation à un climat sans production de variété nouvelle. Quand on a obtenue une variété nouvelle, comme le maïs très précoce, qui convient à un climat mieux au climat du pays, on n’introduit pas une plante acclimatée mais une plante nouvelle. Les amateurs prétendent adapter une plante ou un animal, par le seul effet du temps, sans le changer, à des conditions nouvelles. Cela à mon avis, et au votre, je pense, est bien une chimère. Les sociétés d’acclimatation devraient s’appeler d’introduction.¹¹

Je n’ai pas rencontré dans votre ouvrage une observation qui m’est souvent venue à l’esprit en voyageant, c’est que les hommes font volontiers les races d’animaux domestiques à leur image. Voyez le cheval de course anglais. Il est grand, mince, musclé, mais endurant mal le froid, le chaud ou la mauvaise nourriture; il est peu craintif et point méchant. Parmi les chevaux il ressemble assez à ce que sont les gentlemen anglais parmi les hommes. Les chevaux des Pyrenées ont de petits pieds et courent vite, comme leurs maitres (On dit en francais courir comme un basque). Les chevaux suisses ont de gros pieds et vont lentement, comme les suisses. Les uns et les autres sont élevés sur des pentes. La race beaucoup trop osseuse des vaches de Fribourg, Vaud et Berne se trouve dans la partie de la Suisse où il y a le plus d’hommes gros, grands et lents. La petite race brune de Schwitz, qui est celle de toute la Suisse orientale, correspond à une population plus vive et moins lourde.¹² Il est assez naturel que l’homme recherche dans ses animaux domestiques les qualités quil a lui-même et quil soit indulgent sur les défauts quil a aussi. Le cheval, plus que d’autres, s’adapte aux cavaliers.

Le systeme social aristocratique de l’Angleterre a été bien favorable à la creátion de races d’animaux et de plantes. On y a toujours cru à l’hérédité. On a pu suivre aussi les expériences de génération en générations dans les mêmes propriétés, avec des intentions traditionnelles. Autour de moi je remarque le contraire. Le principe établi est qu’un homme vaut un homme. On s’occupe fort peu de ce qui a précédé et de ce qui suivra. Les propriétés changent continuellement de mains: Les selections peuvent être quelquefois intelligentes, mais elles ne se poursuivent pas longtemps. C’est à peine si les administrations publiques, avec leurs employés indifferents aux choses, remplacent l’esprit de suite des familles. Ainsi dans les démocraties c’est le struggle for life qui domine et qui produit des resultats plus ou moins désirables. Il y a ensuite la selection inconsciente, mais peu de selection éclairée. On s’en apercoit bien.

Quel livre nous pourrions faire, l’un ou l’autre, si nous voulions appliquer les idées des naturalistes et leurs methodes d’observation à l’espèce humaine! en particulier aux faits moraux et intellectuels. Quand on avance en âge, on se trouve avoir accumulé des documents dont on ne dit rien. Je crois beaucoup, par exemple, à l’hérédité des dispositions morales. J’ai connu plusieurs familles où tous les individus, presque tous si vous voulez, ont été bons, ou presque tous méchants, gais ou tristes, persévérants ou légers. Les exceptions s’expliquent facilement par les mères.

Vous savez que les medecins ont constaté plusieurs cas dans les quels un homme ayant engendré un enfant pendant l’ivresse, celui-ci a été idiot. L’ivresse donne une sorte d’idiotisme momentané, qui est héréditaire. Je vais plus loin, mais je ne voudrais pas publier ceci, parceque c’est trop délicat et difficile à établir. J’ai remarqué quelquefois que des enfants, nés avec des inclinations vicieuses (vol, mensonge, rebellion, cruauté, etc), dans des familles honnêtes, venaient de parents qui n’etaient pas bien ensemble ou qui craignaient, l’un au moins, une augmentation de famille. La disposition morale de l’un des parents m’a semblé être nuisible dans ce cas à l’enfant. En sens opposé, il est curieux de voir combien dans les familles historiques il est arrivé souvent que les batards ont été supérieurs aux légitimes. Comparez Don Juan d’Autriche à son frère Philippe II, et le Duc de Vendôme à Louis XIII! Voyez le maréchal de Saxe, Dunois, le batard de Savoie, etc, sans parler de quelques princes ou hommes d’etat adultérins de notre époque.¹³ Dans ces cas, il est vrai, les mères choisies par les princes, ou les pères par les princesses, étaient probablement toujours dans d’excellentes conditions de santé ou de courage, ce qui a pu influer sur les enfants, en particulier sur leur force de volonté et leur audace.

On n’en finirait pas si l’on voulait continuer sur ces questions interessantes. Elles naissent à chaque article de votre livre. Ce que j’en goûte le moins est l’hypothese finale, peut-être pour ne l’avoir pas suffisamment comprise et scrutée.¹⁴ Le courant des autres sciences n’est plus pour les émissions, mais pour les mouvements et ondulations. Après tout vous appelez l’hypothèse provisoire et chacun peut préférer la position de dire: nous ne connaissons pas encore les causes. Je ne crains pas cette position expectante. Elle encourage à chercher.

Les faits concernant les soudures intimes de bourgeons ne me paraissent pas assez completement établis. L’opinion de Caspary sur le Cytisus Adami, n’a pas convaincu, en général, parce que la nature du bourgeon d’où la forme mixte est partie n’est pas assez constatée.¹⁵ Les essais de jacinthes accolées ou de pommes de terre, ne réussissent pas frequemment.¹⁶ La fusion en pareil cas, me semble à priori possible et probable, mais si les faits sont bien réels, ils seraient passés dans la pratique. Le pied sur lequel on a recueilli le bourgeon des Cytisus Adami etait peut- être un produit hybride lui-même. Les pêches lisses sur les pêchers ordinaires sont peut-être des monstruosités accidentelles.¹⁷ On aimerait des preuves plus positives pour admettre une autre origine, par une cause si rare, si peu constatée jusqu’à present.

En renouvelant mes remerciements de votre livre et avec une vive curiosité pour le troisième,¹⁸ je suis toujours, mon cher Monsieur, | votre très dévoué | Alph. de Candolle

CD annotations

3.4 (Bull. soc. … Nantes 1865. 3.7] scored blue crayon

4.4 Robinia … d’épines. 4.6] scored blue crayon

4.5 moins d’épines. 4.6] underl blue crayon

4.13 des terrains.] underl blue crayon

5.1 Je connais … inutile. 5.25] enclosed in square brackets, blue crayon

5.1 Je connais … connaitre? 6.4] crossed blue crayon

Top of letter: ‘Inheritance in Scalp-Muscles— | Keep for Domestic Animals’ blue crayon

Footnotes

For a translation of this letter, see Correspondence vol. 16, Appendix I.

See letter from Alphonse de Candolle, 15 March 1868 and nn. 2 and 3. Candolle refers to Variation and to Schinznach-Bad in Switzerland.

Candolle may be referring to CD’s proposal to discuss variation in nature, and how varieties might be incipient species, in a future work (see Variation 1: 4). This plan was not carried out: CD’s next major work was Descent, published in 1871.

Candolle refers to Paul Antoine Sagot and to Sagot 1860, 1862, and 1865b. There is a lightly annotated copy of Sagot 1865b in the Darwin Pamphlet Collection. Cayenne is a city in French Guiana, where Sagot had been a naval surgeon; he was currently professor of natural sciences at the Ecole normale supérieure de Cluny (Journal de la Société botanique de France 36 (1889): 372–8, Taxonomic literature).

Louis de Vilmorin published his work on the creation of an improved variety of sugar beet in Vilmorin 1856. His grandfather was Philippe Victoire Levêque de Vilmorin, but the two could not have collaborated, since Philippe de Vilmorin died before Louis was born. Candolle was perhaps thinking of Louis de Vilmorin’s father, Pierre Philippe André de Vilmorin. However, no record has been found of work by any of the Vilmorins on Robinia. Louis de Vilmorin published on the possibility of propagating a non-spiny variety of Ulex europaeus (furze) for use as a cattle feed: see, for example, Vilmorin 1850.

CD cited Candolle for this information in Descent 1: 20. The family in question was Candolle’s own (letter from Alphonse de Candolle, 8 March 1871 (Calendar no. 7557).

CD discussed stripes in horses in Variation 1: 56–61.

See Variation 2: 17.

The French doctor has not been identified. The passage referred to is probably Tacitus, Germania, 5: ‘ne armentis quidem suus honor aut gloria frontis’. (‘Even the cattle lack natural beauty and majestic brows.’ Translation by M. Hutton, Loeb edition, 1970.)

CD discussed goldfish (but not their size) in Variation 1: 296–7.

In Variation 2: 313, CD wrote, ‘I am aware that the attempt to acclimatize either animals or plants has been called a vain chimaera.’ On the acclimatisation societies in France, see Osborne 1994.

Fribourg is a city and canton in Switzerland; Vaud, a canton; Bern, a city; and Schwyz, a town and canton (Columbia gazetteer of the world).

Don Juan of Austria, illegitimate son of Emperor Charles V, was an energetic commander (EB 15: 446, s.v. John, Don), in contrast to his half-brother Philip II of Spain, legitimate son of Charles V, who, though a successful administrator, was a poor soldier who used political assassination as policy and whose licentiousness and persecution of Protestants made him notorious (EB). Caesar, duc de Vendôme, was the illegitimate son of Henry IV and an active campaigner (EB 27: 982, s.v. Vendôme). Louis XIII of France, son of Henry IV, was said to be timid and lethargic, and was considered to have been manipulated by his minister, the cardinal de Richelieu. Maurice, comte de Saxe, marshal of France, was the illegitimate son of Augustus II of Saxony (EB 24: 258). Jean, comte de Dunois, the ‘Bastard of Orleans’, was a noted French commander and the illegitimate son of the duc d’Orléans, the brother of Charles VI of France (EB 8, s.v. Dunois, Jean, count of). Several individuals were known as the ‘Bastard of Savoy’. René or Renato, one of the illegitimate sons of Philip II, duke of Savoy, was known as the ‘great Bastard of Savoy’, and governed Savoy, Nice, and Provence (EI 30: 965).

Candolle refers to CD’s hypothesis of pangenesis; see Variation 2: 357–404.

In Variation 1: 387–90, CD discussed the hybrid laburnum, Cytisus adami (now known as +Laburnocytisus adamii), which was a graft hybrid (rather than a hybrid produced from seed) of the common yellow laburnum C. laburnum (now Laburnum anagyroides) and C. purpureus, a dwarf purple broom (Bean 1970–88, 2: 510–11). In appearing to display hybrid fusion and reversion, C. adami was an important case supporting CD’s view that there was no essential difference between asexual and sexual reproduction; see Olby 1985, pp. 76–8. Robert Caspary had supported the view that C. adami was not an ordinary hybrid produced from seed (Variation 1: 388–9). See also Correspondence vols. 13 and 14.

CD discussed attempts to produce graft hybrids of potatoes in Variation 1: 395–6; see also Correspondence vol. 15. He also discussed claims that hyacinths had been grafted by joining two half-bulbs of different colours together, and that the colours sometimes blended (Variation 1: 395).

Candolle refers to nectarines growing on peach trees; see Variation 1: 339–44.

In Variation 1: 8, CD wrote that after his projected work on the variation of organisms in nature (see n. 3, above), he would write another on the difficulties opposed to the theory of natural selection.

Bibliography

Bean, William Jackson. 1970–88. Trees and shrubs hardy in the British Isles. 8th edition, fully revised by D. L. Clarke and George Taylor. 4 vols. and supplement. London: John Murray.

Calendar: A calendar of the correspondence of Charles Darwin, 1821–1882. With supplement. 2d edition. Edited by Frederick Burkhardt et al. Cambridge: Cambridge University Press. 1994.

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. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

EB: The Encyclopædia Britannica. A dictionary of arts, sciences, literature and general information. 11th edition. 29 vols. Cambridge: Cambridge University Press. 1910–11.

EI: Enciclopedia Italiana di scienze, lettere ed arti. 36 vols., and 6 appendixes in 21 vols. Rome: Giovanni Treccani. 1929–2001.

Olby, Robert. 1985. Origins of Mendelism. 2d edition. Chicago and London: University of Chicago Press.

Osborne, Michael Andrew. 1994. Nature, the exotic, and the science of French colonialism. Bloomington and Indianapolis: Indiana University Press.

Sagot, Paul Antoine. 1860. Etudes sur la végétation des plantes potagères d’Europe à la Guyane française. Journal de la Société impériale et centrale d’Horticulture 6: 113–34.

Taxonomic literature: Taxonomic literature. A selective guide to botanical publications and collections with dates, commentaries and types. By Frans A. Stafleu and Richard S. Cowan. 2d edition. 7 vols. Utrecht, Netherlands: Bohn, Scheltema & Holkema. The Hague, Netherlands: W. Junk. 1976–88.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Vilmorin, Louis de. 1850. Note sur une variété non épineuse de l’ajonc ou landier (Ulex europæus, L.). [Read 11 February 1850.] Comptes rendus hebdomadaires de l’Académie des Sciences (Institut de France) 30: 143–5.

Vilmorin, Louis de. 1856. Note sur la création d’une nouvelle race de betteraves à sucre. Considérations sur l’hérédité dans les végétaux. Comptes rendus hebdomadaires de l’Académie des Sciences (Institut de France) 43: 871–4.

Translation

From Alphonse de Candolle¹ 2 July 1868

Geneva

2 July 1868.

To M^r Ch. Darwin

My dear Sir

As I told you three months ago, I took your book to the Schinznach baths, where it was my only and very interesting reading.² I have learned a lot from it, and have found many topics for reflection in it. Your future work on spontaneous species will have more interest for me, however, and I should be very glad to see it. If it is not indiscreet I shall ask you to tell me whether you are making progress in writing it and when we may hope to see it published.³ Depending on your answer, I shall be more or less disposed to concern myself with certain questions which you will probably speak about and on which your opinion, once known, will necessarily have an influence.

While reading, I noted down some thoughts. Here they are, without order and without special elaboration. If you bring out any new editions it is possible that this or that idea or fact may be of some use to you.

You have not been acquainted with the memoirs of Dr Sagot, a French doctor who practised at Cayenne and who is now professor of nat. hist. in the imperial establishment at Cluny. First he published 2 articles on vegetables from temperate countries cultivated in the equatorial regions (Bull. soc. imp. d’horticulture 1860, and Bull. de la Soc. botan. de France, 1862) and then he collected many observations concerning the two kingdoms in the short treatise De l’état sauvage et des resultats de la culture et de la domestication, in-8^o, Nantes 1865. You will find some interesting facts there. If you are unable to obtain this work from booksellers, I could write to the author.⁴

As examples of the tenacity of less important characters, I can cite the fruitless attempts made by the Vilmorins (grandfather and son) to obtain a spineless Robinia pseudo-acacia suitable for horse fodder, and a sugar beet with high sugar levels. Over several generations they sowed Robinia 1^o without spines, 2^o selecting the least spiny among those that germinated, and they did not succeed in obtaining fewer spines. Note that here it is a case of needles, that is to say, superficial and irregular indurations of the bark, not of true spines, whether twigs or leaves or hardened stipules. As for the sugar beet, they invented a probe to extract pieces of the root and verify the sugar content. Then they took seeds from the plants with the highest sugar levels, and so on every 2 years, but they were unable to obtain a strain that was constant enough to be put into commerce.⁵ A sugar beet manufacturer who buys from them confirmed it for me. He told me that the level of sugar depends a great deal on the soil.

I know a family especially well in which over several generations the individuals have possessed a singular strength and mobility in the scalp muscles on the crown of the head. One of them, when he was at college, made a bet that if several thick dictionaries were placed on his head, he would throw them down without moving his head in the slightest, just by moving his scalp forwards. He never failed. Then a friend pressed his hands onto his head using all his strength and could not stop him moving the compressed part. Now the grandfather of this individual, his father and his uncle (the only members of their generation) and his three children (a daughter and 2 sons) had or have exactly the same ability. I cannot yet speak for the 5^th generation, because the children are too young, but here is something even more curious. This family is originally from Provence. It has divided into two branches, one in Geneva, the other still living in France. They have asked the family head of the latter, a cousin in the 17^th degree of the one I spoke of first, whether he could move his scalp in this way. He showed that he could do it. Between the two of them there are 8 generations, the common ancestor and 8 other generations, a total of 17 degrees. I confirm these details from having verified them myself and if I named the family, you would understand that I cannot be mistaken. Now there is a pretty subordinate character and pretty useless for those who possess it! Among the North American savages it would perhaps have prevented one being scalped, because of the terror that it would have caused, but in Europe I don’t think that one would ever have benefited from it. It is not use that has increased the mobility. Probably this character is less rare among the southern peoples, who are very expressive, and since the family in question was designated as noble near Marseille, as early as 1184, it is probable that it has a Greek or Latin ancestry. It has retained a completely useless hereditary character for 3 centuries in Switzerland.⁶

The stripes which often appear on hybrid horses have reminded me that on coats of arms, a bar or stripe is the sign of illegitimacy.⁷ Might the knights of old have got the idea for this sign from observing horses, which they certainly must have known well?

Vol. 2 p. 17. I am not surprised that children born to first cousins were albinos.⁸ This affliction is a sign of weakness.

A French doctor who seems to have retained a taste for Latin books told me lately that Tacitus, speaking of the Germans, says that they had cattle without horns.⁹ I have not had the leisure to verify this.

The height of animals depends a great deal on the space they have to run about. We know how small the horses from some islands (Corsica, Shetland etc) are. I once transported some very small goldfish (golden fish from China) from a little pond at my neighbour’s house to my lake of $\frac{1}{5}$ of an acre. They grew very large and all their successors were much bigger. The nourishment was the same, since it is my own water which runs through the neighbour’s land. These fish were later destroyed. The pond was drained and I bought 34 goldfish of average size, like those one usually keeps in tanks, from another place. As there were no other fish they quickly multiplied and stabilised at around 1500 to 2000. Their length is greater than those I bought, and a merchant to whom I offered them told me they would be found to be too large for aquariums— When there is a thick layer of ice these fish keep to the bottom, arranged in parallel rows.¹⁰

Vol. 2 p. 313. I am among those who have treated acclimatisation as a chimera, but I was speaking of adaptation to a climate without production of a new variety. When a new variety has been obtained, such as very early maize, which suits a climate better than the local climate, one is not introducing an acclimatised plant but a new one. Amateurs claim to adapt a plant or animal to new conditions through the effects of time alone, without changing it. That to my way of thinking, and to yours, I think, is very much a chimera. The acclimatisation societies ought to call themselves introduction societies.¹¹

I did not encounter an observation in your book which has often come to my mind while travelling, which is that men readily make races of domestic animals in their own image. Look at the English racehorse. It is tall, slender, muscular, but ill endures cold, heat or bad food; it is rarely timid and never vicious. Among horses it rather resembles what English gentlemen are among men. The horses of the Pyrenees have small feet and run fast, like their masters (in French one says run like a Basque). The Swiss horses have large feet and go slowly, like the Swiss. Both are raised on hillsides. The excessively bony race of cows from Fribourg, Vaud and Berne is found in that part of Switzerland where there is the largest number of fat, tall and slow men. The small brown race from Schwitz, which is that found in the whole of western Switzerland, corresponds to a more lively and less heavy population.¹² It is fairly natural that man should seek in his domestic animals the qualities that he has himself and that he should be indulgent towards the defects that he shares. The horse adapts more than most to the rider.

The aristocratic social system of England has been very favourable to the creation of animal and plant races. One has always believed in heredity there. It has also been possible to pursue experiments from generation to generation on the same estates, with traditional goals. In my area I notice the opposite. The established principle is that one man is worth the same as another. One cares little what has gone before or what will follow. Estates constantly change hands: sometimes selections can be intelligent, but they do not go on for very long. The public administrations, with their employees who are indifferent to things, can scarcely replace the spirit of succession of families. Thus in democracies it is the struggle for life that dominates and that produces more or less desirable results. Afterwards there is unconscious selection, but little enlightened selection. One can perceive this clearly.

What a book we could write, either one of us, if we should wish to apply the ideas of naturalists and their methods of observation to the human species! Particularly to moral and intellectual facts. When one advances in age, one finds that one has accumulated documents about which one says nothing. I strongly believe, for example, in the heredity of moral disposition. I have known several families in which all the individuals, or almost all if you will, have been good, or almost all wicked, gay or sad. The exceptions are easily explained by the mothers.

You know that physicians have recorded several cases in which the child of a man who engendered it in a drunken state was an idiot. Drunkenness produces a sort of temporary idiocy, which is hereditary. I shall go further, but I would not publish this, because it is too delicate and difficult to establish. I have remarked sometimes that children born with vicious inclinations (theft, lying, rebellion, cruelty, etc.) in honest families came from parents who did not get on well together, or one of whom, at least, was afraid of adding to the family. The moral disposition of one of the parents seemed to me to be harmful to the child in this case. Conversely, it is curious to see how, in historic families, it has often happened that the bastards have been superior to the legitimate offspring. Compare Don Juan of Austria to his brother Philip II, and the Duke of Vendôme to Louis XIII! Look at the Marshal of Saxe, Dunois, the Bastard of Savoy, etc, not to speak of certain illegitimate princes or men of state of our own day.¹³ In such cases, it is true, the mothers chosen by the princes, or the fathers by the princesses, were probably always in an excellent state of health or courage, which might have had an influence upon the children, particularly upon their willpower and their daring.

One would never end if one wished to continue with these interesting questions. They arise at every article of your book. What I like least in it is the final hypothesis, perhaps because I have not sufficiently understood and scrutinized it.¹⁴ The trend in the other sciences is no longer for emissions but movements and waves. After all you call the hypothesis provisional and everyone may prefer the position of saying: we do not yet know the causes. I am not afraid of this anticipatory position. It fosters research.

The facts concerning the intimate unions of buds do not seem to me to be sufficiently established. Caspary’s opinion on Cystisus Adami has not been convincing in general, because the nature of the bud from which the hybrid form arose is not sufficiently verified.¹⁵ The attempts to couple hyacinths or potatoes frequently do not succeed.¹⁶ In such a case, fusion seems to me to be a priori possible and probable, but if the facts are actually real, they would have passed into practice. The plant on which the bud of Cystisus Adami was collected may itself have been a hybrid product. The smooth peaches on ordinary peaches are perhaps accidental monstrosities.¹⁷ One would like more positive proof before accepting a different origin, by a cause that has been so rare and so poorly verified up to now.

In renewing my thanks for your book, and with a lively curiosity about the third,¹⁸ I remain as always, my dear Sir, | your most devoted | Alph. de Candolle

Footnotes

For a transcription of this letter in its original French, see part II: 608–12.