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Darwin Correspondence Project

From Friedrich Hildebrand   18 January 1877

Freiburg i/B.

Jan 18th 1877.

Dear and honoured Sir

I feel very much obliged to you for sending me a copy of your celebrated book on the fertilization of Orchids.1 How much has been worked on this field by you and others since the appearance of the first edition; perhaps it will interest you to hear, that it was this work, by which I was first induced to study the means by which plants are fertilized.2

I have read now your new excellent work on cross and selffertilization and daresay that you have treated the matter in such a way, that nobody can object any more to the evil of selffertilization etc.3 Some years ago I began to make some experiments like yours, but as I have no greenhouse of my own, and those in the distant botanical garden are bad and to small, I had to give up the matter very soon; Science has not lost much by this, for your experiments are quite exhausting.4 Surely the most important matter is, that you have proved the benefits derived not only from mere crossfertilization, but from fertilization between individuals, that are not related nearly, and have grown under different conditions of life. This explains the high value of the adaptation for wide dissemination of plants. Surely I shall look out next summer for finding out some more contrivances by which distinct individuals must be intercrossed. very often I have seen that Insects came first to the eldest flowers of protandrous plants.5

As you have no own observation of the Insects that fertilize Petunia, I may add that Petunia nyctaginiflora is frequented here at Freiburg very much by moths, especially by Sphinx Convolvuli.6 I grow these plants every year in my garden for my boys to catch moths, and last year I was astonished, when the first few flowers were opened to see a Sphinx Conv. frequent it the same evening; the visits lasted till the beginning of October.

I send for you and your son Francis a copy of a little note of mine about the stolones of Trientalis europaea, that will perhaps interest you as an example of contrivances by which perennial plants do not grow every year on the same spot.7

Now my dear Sir I must say Goodbye and | remain | yours | respectfully | Hildebrand

CD annotations

3.2 Petunia nyctaginiflora] underl pencil


Hildebrand’s name appears on CD’s presentation list for Orchids 2d ed. (see Appendix IV).
The first edition of Orchids was published in 1862; Hildebrand had written to CD offering to undertake a German translation, unaware that one had recently been completed by Heinrich Georg Bronn (Bronn trans. 1862; see Correspondence vol. 10, letter from Friedrich Hildebrand, 14 July 1862). Hildebrand began to publish on dimorphism and related topics from 1863; his earlier work had focused on plant anatomy (see Correns 1916, pp. 42–9 for a complete list of Hildebrand’s publications).
Hildebrand’s name is on CD’s presentation list for Cross and self fertilisation (see Correspondence vol. 24, Appendix III).
In his experiments for Cross and self fertilisation, CD had raised up to ten generations of crossed and self-fertilised plants. For a description of his experimental method, see ibid., pp. 10–22.
Protandrous flowers are those in which the male parts mature before the female; the oldest flowers would therefore be more likely to have receptive female organs.
Petunia nyctaginiflora is a South American species of petunia; Sphinx convolvuli is a synonym of Agrius convolvuli (convolvulus hawk-moth).
No copy of Hildebrand’s paper ‘Ueber die Ausläufer von Trientalis europaea’ (On the stolons of Trientalis europaea; Hildebrand 1876) has been found in the Darwin Archive–CUL.


Correns, C. 1916. Friedrich Hildebrand. Berichte der deutschen botanischen Gesellschaft 34 (pt 2): 28–49.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 28 vols to date. Cambridge: Cambridge University Press. 1985–.

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

Hildebrand, Friedrich. 1876. Ueber die Ausläufer von Trientalis europaea. Flora oder allgemeine botanische Zeitung 59: 537–40.

Orchids 2d ed.: The various contrivances by which orchids are fertilised by insects. By Charles Darwin. 2d edition, revised. London: John Murray. 1877.

Orchids: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. By Charles Darwin. London: John Murray. 1862.


Praise for Cross and self-fertilisation: most important point proved is benefit of crossing between related individuals grown under different conditions. This explains adaptive value of dispersal mechanisms.

Letter details

Letter no.
Friedrich Hermann Gustav (Friedrich) Hildebrand
Charles Robert Darwin
Sent from
Source of text
DAR 166: 215
Physical description
ALS 3pp

Please cite as

Darwin Correspondence Project, “Letter no. 10803,” accessed on 17 May 2022,