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Darwin Correspondence Project

From Friedrich Hildebrand   6 December 1876

Freiburg i/B

Decbr 6th 1876.

Dear and honoured Sir!

I feel very much indebted to you for having sent me a copy of your new book.1 Of course I have not as yet read it, but a peep into it has shown me what I could not expect otherwise, that it is again of very great value for science. When I have read it, I shall perhaps write to you about one or the other point. I am very sorry, that the last summer has been here so unfavourable for the experiments I intended to make with flowers, that I have nothing worth to be communicated to you. As you advized me to repeat my former experiments in crossing different coloured varieties of Zea Mais, I tried it last summer, but without the wished success: for in the most cases the pollen of the read variety did not fertilize the flowers of the yellow variety, and when this was the case the fruits of the yellow variety did not show any influence of the red.2 I remember, that Professor Koernike in Bonn has made these experiments in the last time with better success; and perhaps you have heard about it in the meantime from himself; surely he will write to you about it, if you will ask him.3

Perhaps you will be so kind as to give my thanks to Mr. Francis Darwin for sending me his writings about Drosera etc. I have repeated last summer some of your experiments with the same success. Young plants of Drosophyllum I found covered with a large quantity of insects, though the plants were cultivated in an almost always shut greenhouse.4

Repeating my thanks for your kindness I remain | dear Sir | yours respectfully | Hildebrand


Cross and self fertilisation was published in December 1876 (DAR 210.11: 6); Hildebrand’s name is on CD’s presentation list (see Appendix III).
In his letter of 2 January 1868 (Correspondence vol. 16), Hildebrand reported his experiments with red and yellow varieties of Zea mays. CD cited the experiments in Variation 1: 400 n. 126 (second printing) in his discussion of the ‘direct action of the male element on the mother form’. When he was preparing Variation 2d ed., CD asked whether Hildebrand had made further observations on maize (Correspondence vol. 23, letter to Friedrich Hildebrand, 17 July 1875). Hildebrand, in his reply of 26 July 1875 (ibid.), asked CD for seeds to experiment with in the 1876 season because he had failed to produce a constant red variety. The results of CD’s experiments with Zea mays are in Cross and self fertilisation, pp. 16–18 and 233–5. CD cited Hildebrand’s work on self-fertilisation in ibid., pp. 233–4 n.
Friedrich August Körnicke discussed the direct action of pollen in maize in Körnicke 1872, pp. 69–74.
Francis had probably sent a draft of his work on the glands lining the cups of Dipsasus sylvestris (a synonym of D. fullonum, the common teasel; F. Darwin 1877b). In the paper he suggested that the protoplasmic filaments caught solid particles of decaying insects. Hildebrand had repeated experiments on Drosera (the genus of sundews) from Insectivorous plants. Drosophyllum is a genus of insectivorous plants containing only one species, D. lusitanicum, the Portuguese sundew or dewy pine.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 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.

Insectivorous plants. By Charles Darwin. London: John Murray. 1875.

Körnicke, Friedrich August. 1872. Vorläufige Mitteilungen über den Mais. Verhandlungen des Naturhistorischen Vereines der preussischen Rheinlande (und Westfalens) 29: 63–76.

Variation 2d ed.: The variation of animals and plants under domestication. By Charles Darwin. 2d edition. 2 vols. London: John Murray. 1875.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Repeated maize crosses without success: i.e., in most cases yellow and red varieties did not produce fertile offspring.

Letter details

Letter no.
Friedrich Hermann Gustav (Friedrich) Hildebrand
Charles Robert Darwin
Sent from
Source of text
DAR 166: 214
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10701,” accessed on 22 October 2021,

Also published in The Correspondence of Charles Darwin, vol. 24