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Darwin Correspondence Project

From W. E. Darwin   18 May [1864]1


May 18

My Dear Father

I send you pulmonaria anthers, I took them out of buds.

they gradually opened on the gum drying, and the Long styled marked xxx was quite open.2

the one marked xx I saw was much larger than 3 of the others. So I took it off the glass after drawing and compared its pollen with long styled pollen, and there is no doubt that it is long styled.3 x I know also to be long styled, & I am pretty nearly sure that x & xx did not come from the same plant, by the help of drawing or rather making marks under camera lucida, & also counting with my eye & marking on paper; I have made a rough calculation of the comparative bad & good pollen in the long & short.4 of course it cannot be accurate, as in the case of little clusters of them I had partly to guess, also I dare say in some cases pollen tipped up on end or squashed may have mislead, but there is not the least doubt that there are many more imperfect in the long than in the short.

I took pollen from 2 plants of each kind. I found as follows

in Short styled out of 265 pollen grains

247 were good

18 — bad

Long styled out of 193 pollen grains

140 were good

53 — bad.5

if you like, I will measure some more, if you think of any better way please tell me. I cannot judge wh. has most pollen.6

I got Mamma’s letter about Menyanthes.7 I have written to the isle of Wight to find a station, & I am going off to Lyndhurst8

Your affect son | W E Darwin


Shortstyled anthers of Pulmonaria Longstyled anthers of Pulmonaria

CD annotations

3.2 long styled] double underl pencil; ‘?’ pencil
Verso of enclosure: ‘Anthers’ pencil


The year is established by the relationship between this letter and the letter from W. E. Darwin [20 May 1864].
William had already sketched anthers from long-styled and short-styled flowers of Pulmonaria angustifolia (see memorandum and letter from W. E. Darwin, 6 May 1864 and 12 May [1864]). CD had then asked William to observe unopened anthers that were still in the flower-bud (see letter to W. E. Darwin, 14 May [1864] and n. 6). For the sketches of marked anthers, see the enclosure.
In a letter that has not been found, CD queried this statement of William’s (see CD’s first annotation, and letter from W. E. Darwin, [20 May 1864] and n. 2). William had already observed smaller pollen grains from long-styled forms of Pulmonaria angustifolia flowers, and CD had expressed his suspicion that the anthers of long-styled flowers should be shorter, not longer, than those of short-styled (see letters from W. E. Darwin, 14 April [1864] and 18 April 1864 and n. 7, and letter to W. E. Darwin, 14 May [1864] and nn. 5 and 6).
CD had asked for this comparison of good and bad pollen grains from the short-styled and long-styled flowers in his letters to William of 14 May [1864] and [14–17 May 1864].
CD recorded these numbers in his abstract of William’s letters on Pulmonaria angustifolia (see DAR 110: A53). He cited William and these data in Forms of flowers, p. 106, concluding that from the condition of the pollen in the long-styled form, and from the variability of the structures in both forms, one might perhaps suspect ‘that the plant is undergoing a change, and tending to become diœcious’ (Forms of flowers, p. 107).
William often collected plants for CD on the Isle of Wight (see, for example, letter from W. E. Darwin, 12 May [1864] and n. 2). Lyndhurst is a village in the New Forest, nine miles south-west of Southampton.
The diagram is reproduced at 45 per cent of its original size.


Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.


Sends Pulmonaria anthers, with measurements of styles and pollen counts.

Letter details

Letter no.
William Erasmus Darwin
Charles Robert Darwin
Sent from
Source of text
DAR 110: A83–6, A94
Physical description
7pp † diag 1p

Please cite as

Darwin Correspondence Project, “Letter no. 4500,” accessed on 8 July 2020,

Also published in The Correspondence of Charles Darwin, vol. 12