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Darwin Correspondence Project

To Richard Frean   22 February 1863


Feb 22/63.

Dear Sir

I am gratified by your approval of my book on species.1 No doubt in many cases it is impossible to conjecture by what steps certain structures have been acquired. When we reflect on such cases as the stomach of the Pigeon secreting a nutritive fluid—the back of certain Batrachians secreting mucus on which the young feed, we can see that there may have been gradation in the formation of Mammary glands.—2

I have often thought over the case of the degeneration of civilized man; what you suggest, & especially for more care in marriage with more skill in detecting weak constitutions, and the germs of disease, seems to to be our only hope3

I have the &c &c | Yours faithfully | C. Darwin


Richard Frean’s letter commenting on Origin has not been found. The text of this letter is taken from a copy made by Frean and sent to Leonard Darwin in 1882 for possible inclusion in Francis Darwin’s edition of CD’s letters (see the letter from Richard Frean to Leonard Darwin, November 1882, in DAR 144: 298).
CD’s interest in the development of mammary glands was stimulated by George Maw’s review of Origin, which, in criticising the theory of natural selection, raised the question: ‘How, for example, could mammiferous nutrition have been perfected by short stages?’ ([Maw] 1861, p. 7596). In attempting to answer this point, CD referred Maw to Jeffries Wyman’s researches on gestation in Batrachians (Wyman 1859), which showed the ‘possibility of such a transition’ (Correspondence vol. 9, letter to George Maw, 19 July [1861]). See also Correspondence vol. 10, letter to George Maw, 3 July [1862].
In his letter to Leonard Darwin of November 1882 (DAR 144: 298), Frean discussed the letter that elicited the response from CD: In writing I pointed out some difficulties which had occurred to me in the theory of Natural Selection, & then went on to show that if the theory be correct the degeneration of Civilized man was a necessary consequence.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

[Maw, George.] 1861. [Review of Origin & other works.] Zoologist 19: 7577–611.

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.

Wyman, Jeffries. 1859. On some unusual modes of gestation. American Journal of Science and Arts 2d ser. 27: 5–13.


Glad RF approves of book [Origin].

Impossible in many cases to conjecture how structures acquired.

Comments on degeneration of civilised man.

Letter details

Letter no.
Charles Robert Darwin
Richard Frean
Sent from
Source of text
DAR 144: 298
Physical description
C 2pp

Please cite as

Darwin Correspondence Project, “Letter no. 4005,” accessed on 25 July 2024,

Also published in The Correspondence of Charles Darwin, vol. 11