From W. T. Preyer   21 March 1869

Bonn, University,

March 21, 1869.

Dear Sir—

I take the liberty of sending you a popular lecture on the struggle for existence, wherein (before an auditory of more than 600 persons at Cologne) I have attempted to popularize one of the principles of your theory. I differ from your statements only in very few instances e.g. note 9 (p. 42) and note 23 (p. 45) and should be quite unhappy if I have misunderstood any one of your ideas.1

Perhaps it will interest you to hear that I held a course of lectures in the University here last Winter (Oct.–March) “Über die Darwinsche Theorie” constantly heard by 200–250 students. Never before has so numerous an assembly followed the lectures of a “Privatdocent” in this place, whatever the subject might have been. This single fact shows the enormous progress your doctrine is making in Germany.

You would very much oblige me and your scientific friends if you would kindly correct and complete the list of your works which I have compiled as well as it was possible for me.2 I dare say the four titles a, b, c, d are in the main identical with Nr. 1). Without wishing in the least to trespass on your precious time I may beg you to send me back the corrected and completed list of your works before the 15th. of April.3 I have been appointed professor of physiology at the University of Jena last week and am anxious to possess the correct list before I leave Bonn.

I hope in a future work to bring some new important facts in favour of your theory and concluding this letter venture to trouble you once more: Could you send me a copy of your’s and Mr. Wallace’s paper, printed in the proceedings of the Linnean Society 1858?4 I nowhere can find the proceedings here.

I remain | Your’s | Most truly | Wm. Preyer

1
Preyer refers to Der Kampf um das Dasein (The struggle for existence; Preyer 1869). CD’s annotated copy is in the Darwin Pamphlet Collection–CUL. In note 9, Preyer contended that the struggle for existence was not one of individuals against each other, but a competition among all living beings (Preyer 1869, pp. 42–3). In note 23, Preyer argued that CD’s conclusion that supernumerary mammae in women were due to reversion (Variation 2: 57) did not take into account the fact that mammae had been reported on the shoulder or back (Preyer 1869, p. 45; this section is scored in CD’s copy). In Descent 1: 125 n. 38, CD cited Preyer for this information.
2
The list has not been found, but see Ausland, 2 April 1870. For CD’s publications, see Freeman 1977.
3
The list of works was part of Preyer’s sketch of CD’s life, which he submitted to Preußische Jahrbucher in April 1869 (see also letter to W. T. Preyer, [before 21 March 1869] and n. 1); the article was not accepted for publication (Preyer 1896, pp. 148–9).
4
Preyer refers to Darwin and Wallace 1858.

Please cite as “DCP-LETT-6676,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-6676