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Darwin Correspondence Project

To Ernst Haeckel   20 September 1874

Down, | Beckenham, Kent.

Sep 20th. 74

My dear Häckel

I received this morning the 5th Editn of yr Schopfung Geschichte & I thank you for your neverfailing very kind remembrance of me.1 What grand success your books have had, & I am delighted to see your name continually quoted in all parts of the world with high approbation. I am always astonished at the ammount of work you do, I am never idle, but I believe you do as much work in a day as I in a week. I have been going on with my experiments on plants, chiefly on their digestive power, which is exactly the same as in mammals. What our gastric juice can digest so can the secretion of certain plants: what we cannot digest they cannot. I hope to go to press on this subject in the winter.2 Besides this subject and preparing a revised edit of the Descent of Man3 I have done nothing else for the last year. In one of your former letters you said that you had some new ideas & corrections with respect to the hypothesis which I have called Pangenesis;4 I hope that you will some time publish them & let me have a copy. If you have ever an idle quarter of an hour, I should much like to hear where you have been, & what you have been doing this summer.

Believe me my dear Häckel | Yours very sincerely | Charles Darwin

P.S. Since this note was written & closed, I have received to my astonishment, another great Book!! your Anthropogenie.5 I shall read as much as I can of this, & what an evil it is that I never shall be able to read German with any ease.

Good Heavens, take care that you do not wear out your brain.—


CD’s copy of the fifth edition Natürliche Schöpfungsgeschichte (Natural history of creation; Haeckel 1874b) is in the Darwin Library–Down.
Insectivorous plants was published in July 1875 (Correspondence vol. 23, Appendix II).
CD had worked on the revisions to Descent 2d edition from January to the end of March 1874 (see CD’s ‘Journal’ (Appendix II)).
CD’s hypothesis of pangenesis was published in Variation 2: 357–404. For Haeckel’s comments, see Correspondence vol. 20, letter from Ernst Haeckel, 1 March 1872.
CD’s copy of Anthropogenie oder Entwickelungsgeschichte des Mensches (Anthropogeny or developmental history of man; Haeckel 1874a) is in the Darwin Library–Down.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

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

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


Thanks for 5th edition of his book [Natürliche] Schöpfungsgeschichte.

CD continues with his experiments on the digestive power of plants, which is much like that of mammals.

Is also preparing a revised edition of Descent.

Would welcome hearing more of his ideas about Pangenesis.

Postscript about Anthropogenie, which has just arrived. EH’s astonishing productivity.

Letter details

Letter no.
Charles Robert Darwin
Ernst Philipp August (Ernst) Haeckel
Sent from
Source of text
Ernst-Haeckel-Haus (Bestand A-Abt. 1: 1–52/31)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9647A,” accessed on 7 December 2021,

Also published in The Correspondence of Charles Darwin, vol. 22