From George Henslow   [13 or 14 June 1866]1

10 South Crescent | Bedford Sq | W.C.

My dear Mr Darwin,

Very many thanks for your kindness in looking over the proof & for your valuable criticisms.2

I cannot make out however, whether you believe in the fact of reversion.—3 Of course on the whole of this subject, I personally have no opinion to offer at all: as I am simply endeavouring to arrive at the present position of the subject from various authors:—& as to reversion, came to the conclusion stated in my paper, from the various works on the subject. If however you think it a fact, I will modify my statets. accordingly (without, of course, alluding to you)

I should be much obliged, however, if you would kindly give me your positive opinion on that point: as it is a very important one, since it is the one Naudin especially observed.4

the 3 passages you marked as “obscure” oddly enough, were all quotations from Berkeleys Translations in Journal of Hort: Soc: Jan/66   I have endeavoured to elucidate them, as far as I can.5

I have felt immense difficulty in drawing up this paper, as I have not had a scrap of experience of my own—so that I greatly feared it would be defective, yet, as you kindly suggest, if it call attention to the subject that is all I can desire or wish to expect.—6

If you would give me yr opinion on “reversion” as soon as possible I will be much obliged.

I have looked at Naudin’s remarks on “ovules”. & find it to be correct— Offered, however, as a matter to be provd. (p 181–2: in Nouvelles recherches sur l’hybridite)7

Yrs truly | G Henslow

CD annotations

7.1 Offered, … provd. 7.2] double scored blue crayon
1
The date range is established by the relationship between this letter and the letters to George Henslow, 12 June [1866] and 15 [June 1866].
2
CD had commented on the proof pages for Henslow 1866b; see letter to George Henslow, 12 June [1866].
3
In a brief discussion of reversion in Origin, pp. 13–15, CD questioned the widely held view that domestic varieties invariably reverted to their aboriginal stock when they ran wild, stating, more cautiously: ‘our varieties certainly do occasionally revert in some of their characteristics to ancestral forms’ (ibid., p. 15). He also discussed the sporadic appearance in domestic pigeon breeds of features characteristic of the parent rock-pigeon as an example of reversion (ibid., pp. 159–61).
4
In his paper, Henslow discussed work by Charles Victor Naudin (Naudin 1858, 1863, and 1864) that argued that all hybrids inevitably reverted to their parent forms; Henslow concluded: ‘Naudin’s experiments … have very satisfactorily shown that reversions do take place, at least amongst cultivated plants; though it would seem to occur rarely among individuals in a wild state’ (Henslow 1866b, p. 313). Henslow remarked that, as Naudin had failed to protect his hybrid plants from insects, the possibility that they were pollinated by the parent forms remained open. Henslow also criticised Naudin for having worked exclusively with cultivated plants, in which characteristics were less stable than in wild forms (ibid., pp. 311–13). CD had previously criticised Naudin’s experiments for ignoring insect agency (see, for example, Correspondence vol. 10, letter to J. D. Hooker, 30 [June 1862] and n. 11, and Correspondence vol. 12, letter to J. D. Hooker, 22 [May 1864]), and for focusing exclusively on cultivated plants (see Correspondence vol. 13, letter to M. E. Wichura, 3 February [1865]).
5
Henslow quoted from Miles Joseph Berkeley’s translation of Naudin 1864, which appeared in the Journal of the Royal Horticultural Society for January 1866, pp. 1–9 (see Henslow 1866b, pp. 310–11).

Please cite as “DCP-LETT-5120,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5120