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Darwin Correspondence Project

To Miles Joseph Berkeley   29 February [1856]1

Down Bromley Kent

Feb. 29th

My dear Sir

At Hookers suggestion I am going to send to Linnean Soc, an account of the few experiment which I made on salting seeds,2 & I want to know whether you will permit me to tabulate your results with mine.3 I thought of arranging the genera in their nat. Families—

I had intended trying many more experiments but my ardor was damped, by finding that plants would float for so short a time in salt-water:4 I am, however, not quite sure that I tried this part of the affair quite fairly, so shall try the floating again— I kept the plants in the water in my room & therefor too warm & in nearly the dark, & this might have hastened their decay. Will you be so kind as to tell me the proper name of the Aubergine & Corn Salad & of the Kidney Bean; I tried the dwarf.— was yours the tall or dwarf?

I hope you will excuse me troubling you & believe me Dear Sir | Yours sincerely & obliged | Charles Darwin

Do you think it of any consequence how I arrange the Families: shd I follow Lindley or put the Families by mere chance, keeping, perhaps, Endogens & Exogens apart?—5 It will take me some little time to find out order of the Natural Families—

I planted the curious Peas you were so kind as to send me near some other kinds, but unfortunately they were gathered before they were quite ripe, so that I cd not tell positively whether they had been affected.6 But another lot of “Pois sans parchemin”, which were ticketed as your purest seed, were sown separately & have come nearly true, yet some few of the peas were not mottled with brown, & I do not think they could have been impregnated with the pollen of any other variety.— A neighbour has a curious pea with black pods, & these when planted by themselves sometimes come false. This leads me to ask whether you do not think that the change in the seed may be due to mere variation, & not to the anomalous & direct action of the pollen.—7

I have forgotten, indeed, Gærtner’s experiments, which certainly seem to prove direct action of the pollen.—8 Yet on other hand how strange it is that nurserymen take no pains to prevent crossing in the Peas which they raise from seed close together—9 And in Sweet Peas they certainly come true if planted quite close together. Have you tried any other experiments? Can you throw any light on this point which interests me extremely?10

I have a small collection of Pois sans Parchemin from Vilmorin,11 —all his varieties of this sub-class: Have you any wish for a sample of each kind?— One word more, there seems to me capital evidence for & against the natural crossing of Pisum & Lathyrus, & I am completely puzzled.—12


Dated by CD’s reference to collating the results of his seed-soaking experiments for a paper (see n. 3, below). The year 1856 was a leap year.
Joseph Dalton Hooker, initially doubtful of the ability of most seeds to withstand salt water, was interested in the results of CD’s seed-soaking experiments (see Correspondence vol. 5, letter to J. D. Hooker, 13 April [1855]).
Berkeley had reported his results of experiments on immersing seeds in sea-water in Gardeners’ Chronicle and Agricultural Gazette, 1 September 1855, p. 278. CD’s paper summarising his results and those of Berkeley was read at the Linnean Society of London on 6 May 1856. The paper was entitled ‘On the action of sea-water on the germination of seeds’ (Journal of the Proceedings of the Linnean Society (Botany) 1 (1857): 130–40; Collected papers 1: 264–73).
See Correspondence vol. 5, letter to Gardeners’ Chronicle, 21 November [1855], in which CD described why his experiments were ‘of little or no use (excepting perhaps as negative evidence) in regard to the distribution of plants by the drifting of their seeds across the sea’. He later found that dry fruits and capsules floated for much longer (see Origin, p. 359).
See Correspondence vol. 5, letters to M. J. Berkeley, 7 April [1855] and 11 April [1855].
In 1854, Berkeley contributed a regular column on ‘Vegetable pathology’ to the Gardeners’ Chronicle and Agricultural Gazette. In the number for 24 June 1854, he stated his opinion that the colour of the skin of peas is sometimes different from the colour exhibited by the peas of either of the parent plants. He attributed this effect to the direct action of the pollen on the external coat of the ovule (Gardeners’ Chronicle and Agricultural Gazette, 24 June 1854, p. 404).
Gärtner 1849. In Variation 1: 397, CD summarised Karl Friedrich von Gärtner’s experiments on this point as follows: ‘Gärtner … selected the most constant varieties, and the result conclusively showed that the colour of the skin of the pea is modified when pollen of a differently coloured variety is used.’
See Correspondence vol. 5, letter to William and Julius Fairbeard, [October 1855 – May 1856], in which CD asked these nurserymen specifically about this point.
CD eventually decided that different varieties of peas growing together rarely crossed because they were generally self-fertilised before being pollinated by visiting insects. See also n. 12, below.
Pierre Philippe André Lévêque de Vilmorin, French botanist and horticulturist, was a partner in the plant-breeding company Vilmorin-Andrieux.
The problem was discussed in Natural selection, pp. 69–71 and Variation 1: 329–30.


Preparing paper on seed-soaking for Linnean Society ["Action of sea-water on seeds", Collected papers 1: 264–73]. Wants to use MJB’s results. Lost ardour when he found seeds would not float.

Has grown MJB’s purest pea seeds and got a few variants. Gärtner’s experiments suggest direct action of pollen, but CD thinks it is "mere variation".

Letter details

Letter no.
Charles Robert Darwin
Miles Joseph Berkeley
Sent from
Source of text
Shropshire Archives (SA 6001/134/45)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 1834,” accessed on 26 June 2019,

Also published in The Correspondence of Charles Darwin, vol. 6