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Darwin Correspondence Project

From Hermann Müller   8 March 1870


8/3 70.

My dear Sir!

I am very much obliged to you for your assistance in obtaining Mr Fr. Smith’s willingness to revise my Westfalian bees.1 My wishes on this head are perfectly accomplished by your kind mediation, and now I can begin more confidently to elaborate the matter that occupies me since two years.

From a paper, I lately have sent to you, you will have seen, that I intended at first to try an employment of your doctrine on flowers and insects visiting flowers in general.2 But this whole matter being extremely extensive, I have resolved now to elaborate previously only a single section of it, namely the employment of your doctrine on the bees, being adapted in their parts of mouth and in their pollen-collecting apparatus to their nourishment gained from flowers.—3

So turning my attention chiefly to the bees of my neighbourhood, I have found, that this family of insects also in many other regards is highly abundant of facts decisive for your theorie. It is, for instant, very rich of doubtful forms ranked by one Zoologist as a species and by another as a variety, it is very rich of species which differ but very slightly from each other, and the differences, in the one case judged as sufficient for the distinction of species, in the other case looked at as mere varieties, blend into each other in an insensible series.— In the family of bees further there are found many surprising instances of variation of instincts—

I have encountered also many pecularities in the one sex, that can only be acquired by inheritance from the other sex etc. These and other observations, occasionally made, have determinated myself, to exceed, considering the family of bees, the exact limits of my original thema and to treat in its various regards the employment of your theorie—on bees

Till the end of this year I hope to have finished the first memoir on this subject.4

Nevertheless I will have, also during next summer, an eye on all facts relating to the whole thema, and I would be very much obliged to you, if you would communicate to me all your scruples and objections against my statements in the paper lately sent to you.

As you have corrected repeatedly, in former cases, my opinions, I hope, you will also in this case do so.

With the greatest respect | I remain, | my dear Sir, | yours very faithfully | H Müller.

CD annotations

Top of letter: ‘Bot Zeitung’ pencil
Verso of last page: ‘Send to Delpino’5 | ‘Axel’6 pencil; ‘Delpino’ pencil, encircled pencil; ‘Calculate number of flowers each species | Müller | insertion | [original] keep | Angræcum’7 pencil


Müller had asked CD to forward to Frederick Smith a letter asking Smith to identify some of Müller’s Westphalian bees (see Correspondence vol. 17, letter from Hermann Müller, 12 November 1869). No letter from CD to Müller on the subject has been found.
There is an annotated copy of Müller’s paper, ‘Die Anwendung der Darwin’schen Lehre auf Blumen und blumen-besuchende Insekten’ (The application of Darwinian theory to flowers and flower-visiting insects; H. Müller 1869), in the Darwin Pamphlet Collection–CUL.
Müller had also studied the adaptation of Syrphidae (hoverflies or flower flies) mouthparts to various sizes of pollen (see Correspondence vol. 15, letter from Hermann Müller, 23 October 1867).
Müller’s paper, ‘Anwendung der Darwin’schen Lehre auf Bienen’ (Application of Darwinian theory to bees), was published in 1872 (H. Müller 1872).
Possibly a reference to the Swedish botanist Johan Severin Axell.
On the pollination of Angraecum sesquipedale, see Correspondence vol. 15, letter from A. R. Wallace, 1 October [1867] and n. 5.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Delpino, Federico. 1870b. Brief remarks on the biology and genealogy of the Marantaceæ. Scientific Opinion 3: 111–12, 135–7.

Müller, Hermann. 1869. Die Anwendung der Darwin’schen Lehre auf Blumen und blumen-besuchende Insekten. [Read 18 May 1869.] Verhandlungen des naturhistorischen Vereines der preussischen Rheinlande und Westphalens (Botanik, Correspondenzblatt) 26: 43–66.


HM intends studying bees to find evidence supporting CD’s theories. His work has shown him there are problems in separating species from varieties, and has also revealed many surprising instances of variation in habits.

Letter details

Letter no.
Heinrich Ludwig Hermann (Hermann) Müller
Charles Robert Darwin
Sent from
Source of text
DAR 171: 296
Physical description
ALS 3pp †

Please cite as

Darwin Correspondence Project, “Letter no. 7130,” accessed on 20 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 18