Ɛpsilon

From Francis Darwin   16 July 1881

Strassburg

July 16/81

My dear Father

I have got rid of my lumbago by blue pills & mustard plasters & starvation & am all right again.1 I had two days in which I couldn’t rest decently in any position.

I asked de Bary about Max Cornu, and he said he was a clever man who began much better than he went on; his monograph on the Saprolegniæ, was very good but he has lately done nothing but Phylloxera   I know Dyer thinks him a great swell2   Wortmann thinks Pfeffer’s new book very good & not unreadable, though it has too much osmosis in it.3 I have made a little Referat for the Bot Z on a paper by an American in Pfeffers new “Arbeiten”4   He finds that if all the nectar is washed off a nectary it leaves off secreting tho’ if it is only sucked up leaving of course a certain film behind it begins again   When the secretion has been stopped by washing it can be started by putting a drop of syrup on the nectary. I have been hunting for the paper on staining living root hairs but cannot find it, I believe I can when I get home.5 I showed de Bary the thing about the Loranthus which turns head over heels & he didn’t believe in it a bit, chiefly as being an unknown observer in the Gard Chron   I must say I fully believe it, I dont see how a decent observer could make a mistake.6 I have been working at Bryonia embryos trying to trace the connection between the cell divisions in the embryo & the fully formed root   It is horribly irregular with lots of queer oblique walls & very difficult, but it is good practice as nothing is known about it, so that I cant go & look in a book.7

There is a Lime with silvery underside to its leaves which twists its stalk so that the leaf becomes vertical, the parts of the tree in shade do not do so so it is a nice kind of paraheliotropism.8

When de Bary saw Pfeffer’s Arbeiten he said “Na, Pfeffer will auch einen Eisenbahn Zug für sich haben”9   That is a train pupils hanging onto him”

It continues frightfully hot 85 all day indoors and I thingk over 90 in shade out of doors.

Please give Ubbadud my love and say I liked his bubbling fountain letter very much & I will write to him next.10

I shall be precious glad to get back11 | Yours affect | F. D.

Many thanks for auto & photo12

1
Blue pills, containing mercury or a mercury compound, were recommended for constipation associated with lumbago (OED s.v. blue pill; Practitioner: a Journal of Therapeutics and Public Health 13 (1874): 312). The mustard plasters would have been a counterirritant.
2
CD had asked about Maxime Cornu: see letter to Francis Darwin, 8 July 1881. Francis was working with Anton de Bary in Straßburg (Strasbourg). Cornu’s doctoral thesis on the Saprolegniae (a synonym of Saprolegniaceae, formerly described as a family of fungus, but now classified as an oomycete or water mould) is Cornu 1872. For his work on Phylloxera vastatrix (a synonym of Daktulosphaira vitifoliae, grape phylloxera), see Cornu 1874 and Cornu 1879a. Grape phylloxera is a small sap-sucking insect native to North America, accidentally introduced in the mid nineteenth century to Europe, where it devastated native grapevines. Francis also refers to William Turner Thiselton-Dyer.
3
Julius Wortmann. Wilhelm Pfeffer’s new book was his Pflanzen physiologie (Plant physiology; Pfeffer 1881). See also Pfeffer 1877.
4
Francis’s report on William Powell Wilson’s ‘The cause of the excretion of water on the surface of nectaries’ (W. P. Wilson 1881) was published in Botanische Zeitung, 26 August 1881, pp. 545–6. Pfeffer’s journal was, in fact, called Untersuchungen aus dem botanischen Institut zu Tübingen (Studies from the Botanical Institute at Tübingen). The two volumes were produced while Pfeffer was at Tübingen and were essentially a forum for researchers at the institute working under Pfeffer to publish work related to Pfeffer’s own. Pfeffer was a former student of Julius Sachs and probably modelled his journal on Sachs’s Arbeiten des botanischen Instituts in Würzburg.
5
There is an annotated copy of Cornu and Émile Mer’s paper, ‘Recherches sur l’absorption des matières colorantes par les racines’ (Researches on the absorption of coloured matter by roots; Cornu and Mer 1878), in the Darwin Pamphlet Collection–CUL.
6
An article titled ‘A locomotive dicotyledon’ appeared in the Gardeners’ Chronicle, 9 July 1881, p. 42. It described the observations of George Watt, professor of botany at the University of Calcutta, on germinating plants of Loranthus globosus (a synonym of Macrosolen globosus). According to Watt, the radicle fixed itself by means of a viscid disc, and then, if it found itself in an unfavourable site, lifted the seed to another spot, before releasing itself and adhering to a different site, a process that could be repeated several times.
7
Francis seems not to have published on Bryonia.
8
Paraheliotropism: turning to minimise exposure to light (see Movement in plants, p. 419). The lime tree may have been Tilia tomentosa, the silver lime.
9
Literally, ‘Pfeffer too wants to have a railway train for himself’ (an allusion to Julius Sachs).
10
Bernard Darwin’s letter to Francis and Francis’s reply have not been found.
11
Francis returned from Germany on 1 August 1881 (Emma Darwin’s diary (DAR 242)).
12
Presumably CD had sent an autograph and photograph for one of Francis’s colleagues.

Please cite as “DCP-LETT-13245F,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-13245F