Ɛpsilon

To Robert Caspary   25 February [1868]1

Down. | Bromley. Kent. S.E.

Feb: 25.

My dear Prof: Caspary.

I was much pleased to receive your letter   It was very stupid in me to forget that you dislike a translation, for I now remember perfectly your telling me the same thing before,— I wish I had remembered as I certainly would have sent an English Copy—2 The cause of the delay in your receiving your ordered copy probably is that the whole edition of 1500 was sold in a week, which shows that the Book as far as mere sale goes, has been successful. The book is now reprinted and will be ready for sale in a few days or a weeks time, I am glad that you get the reprint, because I have altered two or three passages owing to news from Dr. Hildebrand of Bonn that he has succeeded in making what must be considered as a graft-hybrid— Till hearing this case I felt compelled to speak very doubtfully and perhaps now I have not altered all the passages—3 I fear that my book will not be worth the cost to you; & I again wish I had sent you an English Copy. I am very much obliged for the information about seed products of crossed & self fertilised Euryale—4 Could you spare me some seed of both crossed & self fertilised? that is if they can be sent by post, but I have heard that some seeds of water plants must be kept in water, I would try & grow them, & send some to Kew for same purpose in order to compare their power of growth. You will see in my second vol: a brief notice of a great course of experiments which I am now trying with cross & self fertilised plants   The Results have quite astonished me— In regard to the fertility of the first union; I often find no difference; sometimes increased fertility, occasionally lessened fertility (I find this today with pods from Tobacco plant); but in most instances when a cross is less fertile, I believe it is due to the stigma, requiring as with Leguminosæ successive applications of pollen.5 As yet I have met no exceptions to greater vigour and greater height of plants from crossed seeds over plants from self fertilised seeds— My health has been better of late, though not very good—but I am able to do a fairer share of work.

Mrs. Darwin sends her very kind remembrance to you,6 and with hearty thanks for your friendly letter, Believe me My dear Profr. Caspary, | Yours very sincerely. | Ch. Darwin.

P.S. | Your King a few days ago conferred on me the very great honour of the order “pour le mèrite”.7

Copy

1
The year is established by the relationship between this letter and the letter from Robert Caspary, 18 February 1868.
2
See letter from Robert Caspary, 18 February 1868. Caspary had received the first volume of the German translation of Variation (Carus trans. 1868).
3
The second printing of Variation contained small changes, including the insertion of information from Friedrich Hildebrand on the production of a hybrid potato by grafting (see letter to J. V. Carus, 22 February [1868], n. 3). CD discussed examples of graft-hybrids in Variation 1: 387–97. He had been very interested in Caspary’s own research on graft-hybrids (see Correspondence vol. 14).
4
On Euryale ferox, see the letter from Robert Caspary, 18 February 1868 and n. 4.
5
In 1866, CD began experiments that compared the relative growth and vigour of the offspring of self-fertilised and cross-fertilised plants over several generations (see Correspondence vol. 14). The experiments and preliminary results are described in Variation 2: 127–9. See also Variation 2d ed., 2: 107–9. For CD’s work on tobacco, see Cross and self fertilisation, pp. 203–15.
6
Caspary had visited Down House in May 1866 (Emma Darwin’s diary (DAR 242)).

Please cite as “DCP-LETT-5932,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5932