To Ernst Haeckel   25 September 1873

Down, | Beckenham, Kent.

Sep 25. ’73

My dear Häckel,

I thank you for the present of your book, & I am heartily glad to see its great success.1 You will do a wonderful amount of good in spreading the doctrine of Evolution, supporting it as you do, by so many original observations. I have read the new preface with very great interest. The delay in the appearance of the English translation vexes & surprizes me, for I have never been able to read it thoroughly in German, & I shall assuredly do so when it appears in English.2 Has the problem of the later stages of reduction of useless structures ever perplexed you: this problem has of late caused me much perplexity. I have just written a letter to ‘Nature’ with a hypothetical explanation of this difficulty, & I will send you the paper with the passage marked.3 I will at the same time send a paper which has interested me; it need not be returned. It contains a singular statement bearing on so-called spontaneous generation.4 I much wish that this latter question could be settled; but I see no prospect of it. If it could be proved true this would be a most important to us. A good evolutionist in America, viz: E. Morse has lately published in the Proc. of the Boston Soc. Nat. Hist. a remarkable paper on the the Brachiopoda; & he seems to me to make out pretty clearly that they must be classed actually with Annelids.5 As for myself I have been working for many months on plants, viz:—on physiological points. Whenever I publish I will of course send you my little book.6

Wishing you every success in your admirable labours, I remain | My dear Häckel | Yours very sincerely | Charles Darwin

LS

1
Haeckel had sent CD a copy of the fourth edition of Natürliche Schöpfungsgeschichte (Haeckel 1873); CD’s copy is in the Darwin Library–Down.
2
The translation of Haeckel’s Natürliche Schöpfungsgeschichte (Haeckel 1873), titled The history of creation, was not published until 1876 (Haeckel 1876). Edwin Ray Lankester, who supervised the translation (which was made by Dora Schmitz; Lester 1995, p. 37), told Haeckel in a letter probably dated 26 November 1872 that the translation was finished and mostly printed (Di Gregorio 2005, p. 229).
3
See the last section of the letter to Nature, 20 September [1873].
4
William Henry Dallinger and John James Drysdale had stated that the supposed spontaneous generation of life in boiled (sterile) water was challenged by experiments that showed that the spores of flagellate protozoa could survive temperatures above boiling point (see Dallinger and Drysdale 1873, pp. 57–8).
5
Edward Sylvester Morse had sent CD his essay on the systematic position of Brachiopoda (Morse 1873). See letter to E. S. Morse, 16 September 1873.
6
Insectivorous plants was not published until 1875. Haeckel’s name appears on CD’s presentation list for this work (DAR 210.11: 29).

Please cite as “DCP-LETT-9068,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-9068