Ɛpsilon

To S. H. Vines   4 November 1881

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

Nov. 4th 1881.

My dear Mr Vines

I am exceedingly obliged for your letter, but not a little ashamed of myself for troubling you in such a hurry. It is certain that glycerin & water does not destroy the granulations in the finest roots in the course of 24 hr. But it sometimes does & sometime does not cause their disappearance in thin slices from the upper part of root; & at present I am in utter perplexity.—1

If you are led to look at the finest rootlets (I use Hartnack no 8) after immersion in C. of Amonia (4 to 1000 is a good strength)2 for from 2 hr. to 24 hr., I think that the phenomenon is worth your seeing, & I shall be rewarded & no longer ashamed of having troubled you.

I have now read Sachs on the milk-tubes & De Bary’s most wonderful account of the unarticulated milk tubes in his Vergleichende Anatomie from Schmalhausen.3 (I wish that I had read them sooner) I certainly saw in radicles of about 12 inch length of germinating seeds of Euphorbia myrsinites4 long tubes in same relation to position & not cells (for I showed them to Frank)5 with granular matter after C. of Ammonia, exactly like the granular matter in the cells. This leads me to believe that the rows of cells with granular brownish matter in the fine rootlets of mature plants are modified milk-tubes. But this conclusion is horribly opposed to what the great De Bary says, & I shake in my shoes when I read how many great Botanical physiologists & morphologists have worked on the milk-tubes, & how they differ.—6 I shall go on working for some little time on this subject, & probably send a very brief paper to Linn. Socy. calling attention to the power of certain salts on the contents of certain cells, & on the inference which seems to me probable.7 The general alternation in the contents of the cells was the point which struck me; but alternation is by no means invariable. I have often seen one row divide into 2, & I have seen 3 & once even 4 rows of cells all with granular matter.

Yours very sincerely | Ch. Darwin

1
See letter from S. H. Vines, 2 November [1881]. CD was studying the effects of applying various salt solutions, including carbonate of ammonia (ammonium carbonate), to the roots of some species of Euphorbia and other plants.
2
CD owned a microscope made by Edmund Hartnack, a German microscope maker (see Correspondence vol. 21, letter from Francis Darwin, [before 26 June 1873]). The numbers refer to different objective lenses.
3
Julius Sachs discussed milk tubes (Milchsaftgefässe: literally ‘milk sap vessels’) in Euphorbia and other genera in his Text-book of botany (Sachs 1875, pp. 109–16). In Vergleichende Anatomie der Vegetationsorgane der Phanerogamen und Farne (Comparative anatomy of the vegetative organs of phanerogams and ferns; Bary 1877, pp. 199, 205), Anton de Bary referred to the doctoral thesis on milk tubes in Euphorbia of the Russian botanist Ivan Fedorovich Schmalhausen (Schmalhausen 1877).
4
Euphorbia myrsinites is myrtle spurge.
6
Anton de Bary suggested that milk tubes were analogous to wood xylem vessels (see Bary 1877, p. 196).
7
CD eventually published a paper on the subject in the Journal of the Linnean Society of London; he remarked, ‘I erroneously imagined that there was some relation between the deposition of granules in certain cells and the presence of laticiferous ducts, and consequently an undue number of plants with milky juice were selected for observation’ (see ‘Action of carbonate of ammonia on roots’, p. 245, and letter to Francis Darwin, 28 [October 1881] and n. 13).

Manuscript Alterations and Comments

0.1 (Railway … S.E.R.)] parentheses added
2.1 I use … no 8] added in box
3.2 from Schmalhausen] added
3.2 (I … sooner) 3.3] interl
3.4 in … position] interl
3.6 exactly … cells] interl
3.7 granular] after del interl ‘brow’
3.7 brownish] interl
3.8 the great] interl
3.12 certain cells 3.13] after del ‘the’
3.13 in … cells 3.14] interl

Please cite as “DCP-LETT-13459A,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-13459A