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Darwin Correspondence Project

From Friedrich Hildebrand   16 July 1870

Freiburg i/B

July 16th 1870.

Dear and honoured Sir

You will excuse me that I have not answered your letter at once, but as I had no seeds of Nolana prostrata I wrote for them to Vienna, where I knew that they cultivate this species.1 I have been waiting for an answer till today, but in vain, so I will not keep you awaiting any longer and send you the seeds of Hibiscus Trionum L = H. africanus Roth,2 that are grown in our botanical garden. I hope that this will bee the wanted species. Instead of Nolana prostrata I send you some seeds of N. grandiflora, perhaps you can make some use of them.3

Last year I experimentized with Oxalis Valdiviana4 and found that only the combinations of the sexual organs of equal hight in the three forms were fertile. This year I have seen that the offspring of these combinations belongs partly to the mother partly to the father-form, very few to that form, that has had no part in producing the said offspring. I had not expected that there would be any individual that did not belong to the parent forms, but I think that the reason of this may be that one of the parents has been the offspring of the third form—so the childeren belong partly to the form of the mother, partly to that of the father, and a smaller part to that of the grandfather or grandmother. Allow me to give you an example:

The middle styled form was fertilized with the upper antherae of the long styled and the offspring were: middlestyled 21, longstyled 15, shortstyled 2.5

I beg your pardon that I have written this rather in a hurry, but I wished to have the letter ready before perhaps the war interrupts the communications.6

Believe me dear Sir with my best wishes | yours | respectfully | Hildebrand


Hibiscus africanus is a synonym of H. trionum.
CD did not record any experiments with Nolana grandiflora in Cross and self fertilisation; N. prostrata is the only species mentioned, ibid., pp. 186–7.
Oxalis valdiviana is now O. valdiviensis.
Hildebrand reported the results of these experiments in his paper ‘Experimente und Beobachtungen an einigen trimorphen Oxalis-Arten’ (Experiments and observations on some trimorphic Oxalis species; Hildebrand 1871). CD’s annotated copy of the paper is in the Darwin Pamphlet Collection–CUL.
The Franco-Prussian war broke out on 19 July 1870 (Wawro 2003, p. 65).


Cross and self fertilisation: The effects of cross and self fertilisation in the vegetable kingdom. By Charles Darwin. London: John Murray. 1876.

Hildebrand, Friedrich. 1871. Experimente und Beobachtungen an einigen trimorphen Oxalis-Arten. Botanische Zeitung 29: 415–25, 431–42.

Wawro, Geoffrey. 2003. The Franco-Prussian war: the German conquest of France in 1870–1871. Cambridge: Cambridge University Press.


Sends CD some seeds.

Has been experimenting with Oxalis crosses.

Letter details

Letter no.
Friedrich Hermann Gustav (Friedrich) Hildebrand
Charles Robert Darwin
Sent from
Source of text
DAR 166: 211
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7278,” accessed on 25 February 2021,

Also published in The Correspondence of Charles Darwin, vol. 18