To Friedrich Hildebrand   5 January [1868]1

Down. | Bromley. | Kent. S.E.

Jan 5

My dear Sir

I thank you for your letter which has quite delighted me.2 I sincerely congratulate you on your success in making a graft-hybrid, for I believe it to be a most important observation.3 I trust that you will publish full details on this subject & on the direct action of pollen: I hope that you will be so kind as to send me a copy of your paper.4 If I had succeeded in making a graft-hybrid of the potato, I had intended to raise seedlings from the graft hybrid & from the two parent-forms (excluding insects) & carefully compare the offspring.5 This however wd be difficult on account of the sterility & variability of the potato. When in the course of a few months you receive my 2nd vol. you will see why I think these two subjects so important.6 They have led me to form a hypothesis on the various forms of reproduction, development, inheritance &c. which hypothesis I believe will ultimately be accepted, though how it will be now received I am very doubtful.7

Once again I congratulate you on your success and remain | dear Sir | yours very faithfully | Ch. Darwin

P.S. I hope you will publish your facts about the apple trees.8

LS

1
The year is established by the relationship between this letter and the letter from Friedrich Hildebrand, 2 January 1868.
4
See letter from Friedrich Hildebrand, 2 January 1868 and nn. 3–6. An annotated copy of Hildebrand 1868a is in the Darwin Pamphlet Collection–CUL.
5
In 1867, CD tried to repeat experiments by Robert Trail, who had succeeded in producing a hybrid potato with mottled colouring by joining together two halves of different varieties (see Correspondence vol. 15, letter to J. D. Hooker, 4 April [1867] and n. 3). By excluding insects, CD would have prevented sexual hybridisation resulting from cross-pollination.
6
CD had arranged for Hildebrand to be sent a copy of the first volume of the German translation of Variation (Carus trans. 1868). See letter from Friedrich Hildebrand, 2 January 1868.
7
CD discussed graft hybrids and the influence of the male element on the female element in Variation 1: 387–405; he argued that these and other anomalous forms of reproduction could be explained by his hypothesis of pangenesis (Variation 2: 357–404; see especially pp. 364–6).

Please cite as “DCP-LETT-5777,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5777