CD's Variation is in printer's hands.
Down. | Bromley. | Kent. S.E.
My dear Sir
I feel very guilty at not having sooner thanked you for your letter of Dec 1. which contained much valuable information. The reason has been that I have been very busy in making alterations in my M.S. for my book on domestic animals &c which is at last in the printer's hands. I am very much obliged for the seeds of Cordia &c which are planted & if I can make them flower will be highly interesting to me. Your letter told me much on many points of value to me. You have communicated to me many more cases than any two or three botanists put together.
I have quoted your evidence on the self-sterility of Ocidium flexuosum; it is said to be a native of Brazil, but I much wish to know whether it is a native of your district.
I have many striking cases of similar self-sterility with Orchids, but have hitherto always attributed them to cultivation under unnatural conditions & this makes your case very interesting to me. This is a very dull letter, but I did not wish to defer any longer thanking you.
Believe me my dear Sir | yours very sincerely | Ch. Darwin
P.S. Would you be so good as to tell me whether I ought to direct to you as
Professor or D
- f1 5393.f1The year is established by the relationship between this letter and the letter from Fritz Müller, 1 April 1867.
- f2 5393.f2See Correspondence vol. 14, letter from Fritz Müller, 1 December 1866.
- f3 5393.f3CD had sent the manuscript for Variation to William Clowes & Sons the previous day (see letter to W. D. Fox, 6 February  and n. 2).
- f4 5393.f4Müller may have included seeds of Cordia, a genus he thought was dimorphic, with his letter of 1 December 1866 (Correspondence vol. 14); he had sent specimens of Cordia earlier in that year, and had promised to send seeds (see ibid., letters from Fritz Müller, 1 and 3 October 1866). CD discussed Cordia in Forms of flowers, pp. 117--18, 253.
- f5 5393.f5For Müller's earlier discussions on the self-sterility of Oncidium flexuosum, see Correspondence vol. 14, letter from Fritz Müller, 1 December 1866 and n. 8, and this volume, letters from Fritz Müller, 1 January 1867 and nn. 1, 2, and 5, and 2 February 1867 and n. 9. CD reported Müller's findings in Variation 2: 134--5.
- f6 5393.f6See Variation 2: 133--4; see also Correspondence vol. 12, letter to Daniel Oliver, 18 March  and n. 7. CD discussed his conclusions on this subject in Cross and self fertilisation, pp. 340--7.