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Darwin Correspondence Project

From Albert Müller   28 March 1866

2, Camden Villas, | Jasmin Grove, Penge | SE.

28th. March 1866.

Dear Sir.

I hope you will kindly excuse the liberty, I take in calling your attention to the latest work of my countryman Prof. O. Heer, “Die Urwelt der Schweiz”. Zürich 1865.—1 On pg 599 & seq., in a footnote, the author refers to your valuable observation, that f. sanguinea keeps less slaves in this country than in Switzerland;2 but he adds. ‘es sind diess aber unbedeutende Unterschiede, die nach den Jahreszeiten und auch nach den verschiedenen Stöcken wechseln”. etc.—3

If it does not give you too much trouble, I should feel much obliged by your informing me at your convenience, to what circumstances you attribute the fact that these slaves are captured in greater numbers in Switzerland than in England.—

It seems to me that British ants, being through climate etc. in a harder struggle for life & food, ought rather be found to keep more slaves to attend to their wants, than their Swiss brethren, which have a richer fauna & flora to fall back upon & therefore less labour to perform.—

Apologizing for my intruding upon you, I am, | Dear Sir, | your’s obediently | Albert Müller

Charles Darwin Esqre.


Müller refers to Oswald Heer and Heer 1865.
In Origin, pp. 219–24, CD discussed the slave-making behaviour of the ant species Formica sanguinea. He remarked that in England the slave-ants stayed almost entirely within the nest, whereas in Switzerland they performed various activities outside the nest such as searching for aphids. These differences, CD suggested, were probably due to the slaves being captured in greater numbers in Switzerland than in England (ibid., p. 221).
CD’s remarks on Formica sanguinea are discussed in a note in Heer 1865, pp. 599–601. The passage quoted by Müller is on page 600 and may be translated: ‘But these are insignificant differences, which vary with the seasons and also with different colonies.’


Heer, Oswald. 1865. Die Urwelt der Schweiz. Zurich: Friedrich Schulthess.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.


Oswald Heer [in Die Urwelt der Schweiz (1866)] agrees with CD that Swiss ants (Formica sanguinea) capture more slaves than do British ants. Does this contradict selection, since the British ants are exposed to harder conditions and a poorer fauna?

Letter details

Letter no.
Albert Müller
Charles Robert Darwin
Sent from
Source of text
DAR 171: 280
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 5039,” accessed on 22 January 2021,

Also published in The Correspondence of Charles Darwin, vol. 14