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Darwin Correspondence Project

From Friedrich Hildebrand   24 July 1866


July 24th | 1866.

Dear and honoured Sir

I must excuse myself that I have not answered your former letter, but I was waiting for the copies of my paper on Oxalis to send you one of them;1 Prof. A. Braun intended to read it in the Berlin Academy but was prevented by a severe illness; after being recovered he has read it now, and I hope that I shall be able to send you a copy in the next time.2 I see from the proof-sheet that my expressions have not been quite clear, I hope that they will be so now. I thank you very much for your kind corrections of the mistakes I have made in your language.3

I must answer a passage in your first letter of March, because I see, that you have thought my experiments made only on one plant of Corydalis cava, “that might have been individually peculiar”.4 I see from an English flora that you have not this plant in England,5 it is quite different from the C. lutea where you have a lot of racemes on every plant, here you never have more than one; therefore the experiments made on different racemes are made on as many different plants.6

Further you say in your letter of March that you would be surprised if I did not come at last to the belief in 〈2 or 3 words〉 of individuals7—you 〈2 or 3 words〉 this short expression.— I 〈2 or 3 words〉 that from the first time I 〈1 or 2 words〉 your excellent “Origin of S〈pecies”〉 I have believed in it, and 〈1 or 2 words〉 strongly insist on this point 〈1 or 2 words〉 writing after some time—perhaps 〈1 word〉 on the different kinds of plants-〈fer〉tilisation.—8 A new proof of this law I lastly found in Aristolochia Clematitis that is weiblich-männlich dichogamisch.9 Sprengel has made here a mistake: the Insects find only the stigma developped in the young flower,— soon this stigma is covered and spoiled, then the anthers open themselves, and now the Insects can get out of the flower to bring the pollen to a younger one.10

1 or 2 words〉 〈revie〉w of your paper on 〈Lythrum salicaria w〉as written by me,11 I hope 〈2 or 3 words〉 have been content with 〈1 or 2 words〉 〈pe〉rhaps I shall get a copy 〈1 or 2 words〉 remarks on Corydalis—

〈I〉 am in a great hurry to 〈post〉 your letter, & therefore you 〈must〉 excuse me— Take my best 〈than〉ks for your two very kind 〈le〉tters and believe me dear Sir | yours | faithfully | Hildebrand

CD annotations

Bottom of second page: ‘(Dichogamy) Hildebrand’ pencil


CD had requested a copy of Hildebrand’s paper on Oxalis (Hildebrand 1866c) in his letter of 16 May [1866]; he asked where it had been published in his letter to Hildebrand of 22 July [1866]. For CD’s interest in the paper, see also the letter from Friedrich Hildebrand, 11 May 1866, nn. 2 and 3.
Alexander Carl Heinrich Braun read Hildebrand 1866c at the 21 June 1866 meeting of the Königlichen Akademie der Wissenschaften zu Berlin (Royal Academy of Sciences in Berlin).
CD had corrected the proof-sheets of Hildebrand’s paper on Corydalis cava (Hildebrand 1866d). See letter to Friedrich Hildebrand, 22 July [1866])
For CD’s comments on Hildebrand 1866d, see the letter to Friedrich Hildebrand, 16 May [1866] and nn. 5 and 6. Hildebrand evidently wrote ‘March’ in error.
Corydalis cava, now treated as a synonym of C. bulbosa, is found in central and southern Europe (Tutin et al. eds. 1964–80, vol. 1). According to Lindley 1859, C. bulbosa was found in parts of Britain; however, Bentham 1865 describes only C. lutea and C. claviculata as British species.
Hildebrand alludes to CD’s claim in Origin, p. 97, ‘that no organic being self-fertilises itself for an eternity of generations’. Hildebrand first supported CD’s view on crossing in print in Hildebrand 1867, p. 5.
The literal translation is ‘female–male dichogamic’. Hildebrand published his observations of dichogamy in Aristolochia clematitis in Hildebrand 1866–7a. For more on Aristolochia clematitis and CD’s interest in Hildebrand’s paper, see the letter from Friedrich Hildebrand, 23 October 1866 and nn. 4 and 5.
Christian Konrad Sprengel had described pollination in Aristolochia clematitis in Sprengel 1793, pp. 418–29. For more on Sprengel’s observations, see the letter from Friedrich Hildebrand, 23 October 1866 and n. 3.
Hildebrand had written a review of ‘Three forms of Lythrum salicaria.’ See letter to Friedrich Hildebrand, 22 July [1866] and n. 5.


Bentham, George. 1865b. Handbook of the British flora; a description of the flowering plants and ferns indigenous to, or naturalized in, the British Isles. For the use of beginners and amateurs. 2 vols. London: Lovell Reeve & Co.

Lindley, John. 1859. A synopsis of the British flora arranged according to the natural orders. Containing vasculares or flowering plants. 3d edition. London: Longman, Brown, Green, Longmans, & Roberts.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Sprengel, Christian Konrad. 1793. Das entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen. Berlin: Friedrich Vieweg.


Assures CD of his belief in descent from his first reading of Origin.

Describes a case of dichogamy.

Letter details

Letter no.
Friedrich Hermann Gustav (Friedrich) Hildebrand
Charles Robert Darwin
Sent from
Source of text
DAR 166: 204; DAR 49: 150
Physical description
4pp damaged †

Please cite as

Darwin Correspondence Project, “Letter no. 5166,” accessed on 21 September 2020,

Also published in The Correspondence of Charles Darwin, vol. 14