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Darwin Correspondence Project


To William Benjamin Carpenter   26 January [1858]1

Down Bromley Kent

Jan 26th

Dear Carpenter

Will you read the enclosed which need not be returned?2 And I beg & supplicate you to direct your gardener to plant in due time on the island, of which you are sovereign Lord,3 some scarlet Kidney Beans, & when you are there, move the wing-petals of several flowers, soon after flower has opened & once a second time: it will not take you five minutes to do a dozen or two flowers, & see whether you do not get a crop.4 Though I must confess I can hardly believe that your island is not visited occasionally by at least Humble bees. If after careful watching you really never see a Bee of any species, it would be eminently curious to observe what plants grow & seed freely there. For in many other plants besides Leguminosae the agency of insects is highly useful & in some few cases indispensable to their fertilisation.5

I hope that you will be so kind as to make the experiment on the Kidney-beans & believe me dear Carpenter

Yours very sincerely | C. Darwin


Dated by CD’s experiments on the fertilisation of kidney-beans by bees begun in the summer of 1857. In October 1857, he summarised his results for the Gardeners’ Chronicle (see n. 2, below). He continued his experiments during the summer of 1858 and described them in his paper ‘On the agency of bees in the fertilization of papilionaceous flowers, and on the crossing of kidney beans’ (Collected papers 2: 19–25, and letter to Gardeners’ Chronicle, [before 13 November 1858]).
Possibly a copy of CD’s inquiry to the Gardeners’ Chronicle, published in October 1857 (see Correspondence vol. 6, letter to Gardeners’ Chronicle, 18 October [1857], and Collected papers 1: 275–7).
Carpenter and his family spent their summers on Holy Island, in the Firth of Clyde, off the western coast of Scotland (Kölliker 1899, p. 160). The island, whose bay was particularly suitable for carrying out researches on marine organisms, had only one habitable cottage, half of which Carpenter rented to the Geological Survey of Great Britain for Thomas Henry Huxley to carry out summer fieldwork (L. Huxley ed. 1900, 1: 155).
CD had performed the same experiment at Down in June 1857. The results were recorded in his Experimental book, p. 37 (DAR 157a) and published in his letter to the Gardeners’ Chronicle (see n. 2, above). CD’s purpose was to imitate the action of bees moving the petals of bean flowers as they sucked at the nectar. He suggested that the movement brought about the pollination of the flowers. In his own experiments, he covered the plants with gauze to prevent the access of bees; in his letter to the Gardeners’ Chronicle in 1857, he stated that it would be interesting to know whether beans ever set seed in areas where there were few or no bees (Collected papers 1: 276).
Of all the Leguminosae (the plants which presented the greatest challenge to CD’s hypothesis that all organic beings occasionally cross), the kidney-bean was the case ‘which convinces me that there is a direct relation between the structure of papilionaceous flowers & the agency of insects’ (Natural selection, p. 69).

Letter details

Letter no.
Darwin, C. R.
Carpenter, W. B.
Sent from
Physical description


Asks WBC to plant some kidney beans [on Holy Island near Arran] and to see whether they are ever visited by bees. If no bees visit the island, it would be "curious" to observe what plants grow there.

Please cite as

Darwin Correspondence Project, “Letter no. 2043,” accessed on 13 February 2016,