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Darwin Correspondence Project

From Armand de Quatrefages1   4 March 1868

Paris

4 Mars 68

Monsieur et cher confrere

Je crois pouvoir répondre sur le champ à la question que vous me posez au sujet de la proportion des sexes chez le ver-à-soie.—2 Il n’a pas été fait, que je sache, de recherches statistiques a ce sujet; mais la pratique des éleveurs prouve qu’ils comptent en moyenne sur un nombre a peuprès egal de males et de femelles. C’est à la même conclusion que conduisent quelques détails donnés par Mr Robinet dans son manuel bien que le but des pratiques dont il parle ne soit pas la détermination du rapport que vous cherchez.—3 Enfin les moeurs même des Insectes dont il s’agit me semble confirmer cette déduction qui ressort de tout ce que je puis me rappeler à cet egard— Je crois donc qu’on peut admettre l’egalité numerique des sexes; mais, je le répète, je ne connais pas de statistique précise à ce sujet.

Je vous remercie vivement de l’ouvrage que vous m’annonciez et suis heureux de le voir traduit.4 Quoique lisant l’anglais assez couramment, je lis encore plus aisément le francais et une bonne traduction m’est toujours agréable. En outre j’aime à voir vos ouvrages se répandre. Par la nature des questions que vous soulevez, vous forcez l’attention publique à se porter sur les sciences naturelles et elles ne peuvent qu’y gagner.

Sans doute je ne suis pas toujours de votre avis et en particulier je ne puis partager votre doctrine génerale, dans son application à l’origine des espèces. Sans savoir comment celles ci ont pris naissance, il m’est impossible de concilier certains faits avec cette application. Mais sur bien des points je suis heureux de me rencontrer avec vous et je rends dailleurs entierement justice à tout ce que votre théorie a de séduisant. Il est probable que j’essayerai de résumer mes opinions sur ces questions dans la Revue des deux Mondes.5 On m’y engage beaucoup et je le ferai, je pense, dès j’en aurai le temps. Mr Laugel vient de vous y consacrer un article.6 Mais il me semble qu’un naturaliste physiologiste peut encore prendre la parole après cet éminent auteur.

Recevez Monsieur et cher confrere l’expression de tout mon dévouement. | De Quatrefages

CD annotations

Top of letter: ‘(DistinctionQQQQ)’ red crayon
End of letter: ‘Q says he knows not of any statistics, but believes sexes nearly equal— alludes to Robinet— I conclude if any great inequality wd. certainly have been observed.—’

Footnotes

For a translation of this letter, see Correspondence vol. 16, Appendix I.
CD’s letter has not been found, but in his letter to H. T. Stainton of 2 March [1868], CD mentioned that he planned to write to Quatrefages about silk-moths in France.
Quatrefages refers to Stéphane Robinet and his manual on the raising of silkworms (Robinet 1848; CD’s annotated copy is in the Darwin Library–CUL (see Marginalia 1: 712–13)). Robinet describes a method for separating male and female cocoons by weight; the practice is based on the assumption that the sexes occur in approximately equal proportion (see ibid., pp. 267–8). In Descent 1: 345–6, CD refers to Robinet’s description.
Quatrefages’s name appears on CD’s presentation list for the French translation of Variation (Moulinié trans. 1868; see Correspondence vol. 16, Appendix IV).
Quatrefages’s long essay-review on the origins of animal and vegetable species appeared in five instalments in the Revue des Deux Mondes between December 1868 and April 1869 (Quatrefages 1868–9). CD’s annotated copy of an offprint of the article is in the Darwin Pamphlet Collection–CUL.
Auguste Laugel’s article, ‘Darwin et ses critiques’ (Laugel 1868), looked at both philosophical and natural historical critiques of Origin.

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 26 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.

Laugel, Antoine Auguste. 1868. Darwin et ses critiques. Revue des deux mondes 2d ser. 74: 130–56.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Quatrefages, Armand de. 1868–9a. Origines des espèces animales et végétales. Revue des deux mondes 2d ser. 78 (1868): 832–60; 79 (1869): 208–40; 80 (1869): 64–95, 397–432, 638–72.

Robinet, Stéphane. 1848. Manuel de l’éducateur de vers à soie. Paris: Librairie Agricole de la Maison Rustique.

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

Translation

From Armand de Quatrefages1   4 March 1868

Paris

4 March 68

Dear Sir and colleague,

I think I can reply on the spot to the question you put to me concerning the proportion of sexes in the silkworm—2 There has not been any statistical research done on this subject, so far as I know; but breeders’ practice proves that they expect on average an almost equal number of males and females. Certain details given by Mr Robinet in his manual tend to the same conclusion, even though ascertaining the ratio that you are seeking was not the goal of the practices of which he writes.3 Lastly, the very habits of the Insects in question seem to me to confirm this deduction, which emerges from all that I can recall in regard to this issue.— Therefore, I believe that one can assume numerical equality of the sexes; but, I repeat, I know of no precise statistic on this subject.

I thank you heartily for the work you brought to my attention and I am happy to see it translated.4 Though I read English fluently enough, I read French still more easily and a good translation is always a pleasure to me. Moreover I like to see your works disseminated. By the nature of the questions you raise, you force public attention to bear on the natural sciences and they can only gain from this.

Certainly I do not always agree with you, and in particular I cannot share your general doctrine in its application to the origin of species. Without knowing how these came into being, I find it impossible to reconcile certain facts with that application. But I am happy to meet you on a great many points and moreover I entirely acknowledge all the attractions of your theory. It is probable that I shall try to summarise my opinions on these questions in the Revue des Deux Mondes.5 I am being strongly urged to do so and will do it, I think, as soon as I have time. Mr Laugel has just devoted an article to you in it.6 But it seems to me that a naturalist and physiologist can still take the floor after that eminent author.

My dear Sir and colleague, accept the expression of my full devotion | De Quatrefages

Footnotes

For a transcription of this letter in its original French, see part I: 234.
CD’s letter has not been found, but in his letter to H. T. Stainton of 2 March [1868], CD mentioned that he planned to write to Quatrefages about silk-moths in France.
Quatrefages refers to Stéphane Robinet and his manual on the raising of silkworms (Robinet 1848; CD’s annotated copy is in the Darwin Library–CUL (see Marginalia 1: 712–13)). Robinet describes a method for separating male and female cocoons by weight; the practice is based on the assumption that the sexes occur in approximately equal proportion (see ibid., pp. 267–8). In Descent 1: 345–6, CD refers to Robinet’s description.
Quatrefages’s name appears on CD’s presentation list for the French translation of Variation (Moulinié trans. 1868; see Correspondence vol.16, Appendix IV).
Quatrefages’s long essay-review on the origins of animal and vegetable species appeared in five instalments in the Revue des Deux Mondes between December 1868 and April 1869 (Quatrefages 1868–9). CD’s annotated copy of an offprint of the article is in the Darwin Pamphlet Collection–CUL.
Auguste Laugel’s article, ‘Darwin et ses critiques’ (Laugel 1868), looked at both philosophical and natural historical critiques of Origin.

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 26 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.

Laugel, Antoine Auguste. 1868. Darwin et ses critiques. Revue des deux mondes 2d ser. 74: 130–56.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Quatrefages, Armand de. 1868–9a. Origines des espèces animales et végétales. Revue des deux mondes 2d ser. 78 (1868): 832–60; 79 (1869): 208–40; 80 (1869): 64–95, 397–432, 638–72.

Robinet, Stéphane. 1848. Manuel de l’éducateur de vers à soie. Paris: Librairie Agricole de la Maison Rustique.

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

Summary

Proportions of sexes of the silkworm are about equal, but knows of no statistics.

Cannot share his view of origin of species.

Letter details

Letter no.
DCP-LETT-5980
From
Jean Louis Armand (Armand de Quatrefages) Quatrefages de Bréau
To
Charles Robert Darwin
Sent from
Paris
Source of text
DAR 85: B66–7
Physical description
4pp (French) †

Please cite as

Darwin Correspondence Project, “Letter no. 5980,” accessed on 22 October 2019, https://www.darwinproject.ac.uk/letter/DCP-LETT-5980.xml

Also published in The Correspondence of Charles Darwin, vol. 16

letter