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Darwin Correspondence Project

To J. V. Carus   5 February 1869

Down. | Bromley. | Kent. S.E.

Feb 5 1869

My dear Sir

Your kindness has been very great & I thank you cordially. Although I felt much curiosity respecting the horns of the merinos I did not intend to cause you so unreasonable an amount of trouble.1

It seems evident from your two correspondents that if there is any difference at all in the rate of development of the horns in the two cases, it must be extremely slight. There is so great a difference in this respect between the reindeer & other deer, & between antelopes in which one or both sexes have horns, that I fully expected something of the kind wd be observed in sheep.2 If you have any opportunity, I beg that you will return my sincere thanks to Messrs Sison & Steiger.3

I received the newspaper safely with excellent wood cut.4

During the last 6 weeks I have been at work in preparing a new Ed. of the Origin, & have found a good deal to alter & I hope I have in some degree improved it.5 When published, in about 2 month’s time, I will send you a copy.

Pray again accept my very sincere thanks for your kindness & believe me | yours very faithfully | Charles Darwin


See letters from J. V. Carus, 22 January 1869 and 2 February 1869.
For more on CD’s interest in the development of horns, see the letter to George Cupples, [6–9? January 1869] and n. 2. For CD’s earlier correspondence on the age of development of antlers or horns in deer and antelope, see Correspondence vol. 16. In Descent 1: 286–90, CD summarised the results of his inquiries on the development of horns and noted that the results regarding merinos were anomalous (ibid., pp. 289–90).
CD refers to Robert Sison and a breeder named Steiger, who supplied Carus with information on the development of horns in merinos. Steiger has not been further identified.
Carus had sent an article by Sison (Sison 1867) that contained a woodcut of one of the rams of the royal flock at Lohmen, Saxony. The article is in the Darwin Pamphlet Collection–CUL. See plate facing p. 34.
CD had started work on the fifth edition of Origin on 26 December 1868 (Correspondence vol. 16, Appendix II). He finished corrections on 10 February 1869 (see ‘Journal’ (Correspondence vol. 17, Appendix II)). It was published in June 1869 (letter from R. F. Cooke, 22 June 1869).


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 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.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Sison, Robert. 1867. Lohmen. Königliche Merino Stammschäferei Sachsens v. 1765. Agronomische Zeitung 22: 209–12.


Thanks JVC for his information (from two correspondents) on the rate of growth of merino rams’ horns.

CD has been revising Origin [5th ed.]. Has found a good deal to alter.

Please cite as

Darwin Correspondence Project, “Letter no. 6601,” accessed on 23 September 2020,

Also published in The Correspondence of Charles Darwin, vol. 17