To Francis Darwin   3 August [1878]1

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

Aug. 3d

My dear F.

Having an idle 14 of hour, I will write.— I am delighted that your climbing work seems so interesting. At p. 17 (2d Edit.)) of my Climbers I mention the spiral shoots of Akebia & Stauntonia (both memispermeæ); but with one the spirality was clearly connected with very slow growth or ill-health— the poorer the shoot the more spiral it became.2 Very many thanks about Heliotropism.— I hope that you gave my invitation to Sachs, whether or no he accepts it.3

Get name of malvaceous plant which sleep, though I have one good case with Sida, & here leaves turn vertically up at night.—4

The Anagallis seem very odd.—5

I have just succeeded in showing tips of radicles of Tropæolum majus are sensitive to square of card; but failed signally with those of Vegetable marrow, yet with some indication that they are really sensitive.— We must try Horse & Spanish Chesnut.—6

Yours affect | C. Darwin

William has sent me your letter to him, & we had a jolly laugh over the difficulty of finding a present for a Professor 5ft. 8 inches high &c. &c7

Your present ought to be something handsome, & I pity you in having to solve such a problem.— “Oh no” is Bernard’s8 favourite expression now, & he brings it in delightfully, reproving us for our nonsense.—

1
The year is established by the relationship between this letter and the letters from Francis Darwin, 24 and 25 July 1878 and [before 3 August 1878].
2
Francis had described his own and Julius Sachs’s observations on spiral shoots of Menispermum (the genus of moonseed) and Akebia (the genus of chocolate vines) in his letter of [before 3 August 1878]. Stauntonia and Akebia are now placed in the family Lardizabalaceae, which was formerly a division of the Menispermaceae. CD refers to Climbing plants 2d ed. For more on Sachs’s views on climbing plants, see the letter from Francis Darwin, [before 17 July 1878].
3
See letter from Francis Darwin, [before 3 August 1878]. CD had asked about heliotropism in moulds and roots in his letter to Francis of 25 July [1878]; he also extended an invitation for Sachs to visit him at Down.
4
See letter from Francis Darwin, [before 3 August 1878] and nn. 5 and 9. CD described sleep movements in Sida rhombifolia (arrowleaf sida) in Movement in plants, pp. 322–3.
5
In his letter of [before 3 August 1878], Francis had drawn a sketch of the unusual sleep movements of Anagallis arvensis (scarlet pimpernel).
6
CD described his experiments on the sensitivity of the tip of the radicle or embryonic root of Tropaeolum majus (nasturtium) in Movement in plants, pp. 167–8. He described similar sensitivity in Aesculus hippocastanum (horse chestnut) in ibid., pp. 172–4, but did not discuss the Spanish chestnut (Castanea sativa).
7
William Erasmus Darwin. The letter has not been found.
8
Bernard Darwin was Francis’s son.

Manuscript Alterations and Comments

1.4 or] over ‘&’
1.5 became.] above del ‘was.’
6.2 8] over ‘10’
7.1 in] after del ‘for’

Please cite as “DCP-LETT-11639,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11639