To Francis Darwin   4 July [1879]1

Down.—

July 4th

My dear F.

It will be very important for us to learn whether it is the tips of radicles that perceive & cause them to bend to damp surfaces, so learn if you can how Sachs tried Beans.— I know that you tried mustard(?) but I forget result— in fact my Brain is in complete addle about what we have tried.2 I think when you are at home we ought to try one other Graminous plant. viz Wheat—. about radicle bending up from surface of water (as Cieleski says Maize does) keeping radicle in very damp air.—3

I was talking yesterday with Ubba about your return, but could not make him understand that it wd. be many days before you returned. He maintained that you wd. come before Aunt Etty. He said “it is likely he will bring me some soldiers”— so a word to the wise.— I said that I shd be very glad when poor Dada came back. This he seemed to think very odd & asked me many times “what for?” His little head is as full of soldiers, dums & tumpets as ever it can be stuffed.—4

Your affect. C. D.

1
The year is established by the relationship between this letter and the letter from Francis Darwin, 4 July 1879.
2
In his paper ‘Ueber das Wachsthum der Haupt- und Nebenwurzeln’ (On the growth of primary and adventitious roots; Sachs 1873–4, pp. 432–4), Julius Sachs had found that roots of Vicia faba (broad bean) whose tips had been removed curved in random directions when placed horizontally on moist earth. Francis had been studying the effect of applying caustic to the tips of radicles of white mustard (Sinapis alba; see letter from Francis Darwin, 4 July 1879).
3
In experiments with Zea mays (maize), Theophil Ciesielski had observed that when a root was placed on a wet horizontal surface so that only the underside was wet, it curved upwards away from the surface (Ciesielski 1872, p. 25). Sachs had dismissed Ciesielski’s results, claiming they were due to Ciesielski’s having allowed the roots in his experiments to dry out partially during preparation (Sachs 1873–4, p. 401).
4
Ubba was a pet name for Francis’s son Bernard Darwin. Francis returned to England at the beginning of August 1879; his sister Henrietta Emma Litchfield and her husband Richard Buckley Litchfield visited Down from 19 to 21 July 1879 (Emma Darwin’s diary (DAR 242)). Francis had already sent Bernard Prussian paper soldiers ‘with tumpets & dums’ (probably Bernard’s words for trumpets and drums; see letter from Francis Darwin, [after 16 June 1879]).

Manuscript Alterations and Comments

1.1 it is the] interl
1.4 when you are] interl
1.6 (as … does)] interl

Please cite as “DCP-LETT-12134A,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-12134A