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Darwin Correspondence Project

To Alphonse de Candolle   18 January [1873]1

Down, | Beckenham, Kent.

Jan. 18th

My dear Sir

It was very good of you to give up so much of your time to write to me your last interesting letter.2 The evidence seems good about the tameness of the alpine Butterflies, & the fact seems to me very surprising; for each butterfly can hardly have acquired its experience during its own short life.— Will you be so good as to thank M. Humbert for his note, which I have been glad to read.3 I formerly received from a man, not a naturalist staying at Cannes, a similar account, but doubted about believing it.4 The case, however, does not answer my query, viz whether Butterflies are attracted by bright colours, independently of the supposed presence of nectar.

I must own that I have great difficulty in believing that any temporary condition of the parents can affect the offspring. If it last long enough to affect the health or structure of the parents, I can quite believe the offspring would be modified. But how mysterious a subject is that of generation! Although my hypothesis of pangenesis has been reviled on all sides,5 yet I must still look at generation under this point of which; & it makes me very averse to believe in an emotion having any effect on the offspring.

Allow me to add one word about blushing & shyness: I intended only to say that the habit was primordially acquired by attention to the face; & not that each shy man now attended to his personal appearance.—6

With sincere thanks, believe me, yours very faithfully | Ch. Darwin


The year is established by the relationship between this letter and the letter from Alphonse de Candolle, 14 January 1873.
According to CD’s hypothesis of pangenesis, each cell in an organism produced particles (gemmules) that were capable of generating new cells; the gemmules circulated throughout the organism until required, and then congregated in the right place in order to reproduce or in some cases reconstruct parts (Variation 2: 357–404). Francis Galton had tested the hypothesis by breeding from rabbits transfused with other rabbits’ blood, but had been unable to provide any support for it (see Correspondence vols. 18 and 19, and Galton 1871).
See Expression, pp. 345–7.


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.

Expression: The expression of the emotions in man and animals. By Charles Darwin. London: John Murray. 1872.

Galton, Francis. 1871. Experiments in pangenesis, by breeding from rabbits of a pure variety, into whose circulation blood taken from other varieties had previously been largely transfused. [Read 30 March 1871.] Proceedings of the Royal Society of London 19 (1870–1): 393–410.

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


The evidence of tameness of Alpine butterflies [see 8672] seems good and the fact is surprising to CD for they can hardly have acquired this in their short life-time.

The question whether butterflies are attracted to bright colours independently of the supposed presence of nectar is still unanswered.

CD has great difficulty in believing that any temporary condition of parents can affect the offspring.

Pangenesis is much reviled, but CD must still look at generation from this point of view, which makes him averse to believing that an emotion has any effect on the offspring.

Letter details

Letter no.
Charles Robert Darwin
Alphonse de Candolle
Sent from
Source of text
Archives de la famille de Candolle (private collection)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 8741,” accessed on 25 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 21