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Darwin Correspondence Project

To John Lubbock   26 March [1867]


March 26th

My dear Lubbock

I have not read or heard of the book on “Primitive Marriage” nor do I know what “exogamy” means; so that I am not a little in the dark.—1

I do not think any evidence has been published of an instinctive repugnance to close intermarriage with animals. I have received some private accounts of such feeling with domestic animals, but they were so few, that I have not thought it prudent to give them.2

Indirectly the end must, I think, be largely gained by the wandering of the young males, & their expulsion from the herd in social animals, by the old males.3 I heartily wish I could have given you any better information. In my new book I have a chapter on Interbreeding & give all the evidence which I have.4

It is a long time since we have met & if Mahomet does not come to the mountain, the mountain must come some Sunday to Mahomet.5

Yours affectly | C. Darwin


See letter from John Lubbock, 25 March 1867 and nn. 1 and 2. CD later read John Ferguson McLennan’s book (McLennan 1865), an annotated copy of which is in the Darwin Library–CUL (see Marginalia 1: 559–61). CD referred to his ideas several times in Descent; for CD’s discussion of exogamy related to sexual selection, including the views of McLennan and Lubbock, see especially Descent 2: 358–65. On contemporary criticism of McLennan’s ideas, see the introduction in McLennan 1970, pp. xxxviii–xl. See also Jann 1996.
See letter from John Lubbock, 25 March 1867. CD refers to his book on domestic animals and plants, Variation. In Descent 2: 361–2, CD noted the breeding habits of several different primates.
CD included this idea in Descent 2: 362–3.
CD refers to chapter 17 in Variation (Variation 2: 114–44).
CD alters the proverb attributed to Francis Bacon: ‘If the mountain will not come to Mohamet, Mohamet must go to the mountain’ (Speake ed. 2003, p. 210). The most recent recorded meeting of Lubbock and CD was on 2 October 1866 (see Correspondence vol. 14, letter to J. D. Hooker, 2 October [1866]).


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.

Jann, Rosemary. 1996. Darwin and the anthropologists: sexual selection and its discontents. In Sexualities in Victorian Britain, edited by Andrew H. Miller and James Eli Adams. Bloomington and Indianapolis: Indiana University Press.

McLennan, John Ferguson. 1865. Primitive marriage: an inquiry into the origin of the form of capture in marriage ceremonies. Edinburgh: Adam and Charles Black.

McLennan, John Ferguson. 1970. Primitive marriage: an inquiry into the origin of the form of capture in marriage ceremonies. Edited and with an introduction by Peter Rivière. Reprint of the first edition. Chicago: University of Chicago Press.

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.

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


Close inbreeding and factors acting against it.

Letter details

Letter no.
Charles Robert Darwin
John Lubbock, 4th baronet and 1st Baron Avebury
Sent from
Source of text
DAR 263: 65 (EH 88206509)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 5463,” accessed on 22 April 2021,

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