Ɛpsilon

To M. T. Masters   [28 March – 5 April 1867]1

The explanation of the sterility of the seed-capsules of the Cypripedium sent to me I have little doubt lies in the circumstance of their having been fertilised by pollen taken from the same plant or seedling.2 I now know of a long series of cases in which various orchids are absolutely sterile when fertilised by their own pollen, (proved however to be as itself effective) but which can be easily fertilised by pollen taken from other individuals of the same species, or from other and quite distinct species.—3 These facts strike me as most remarkable under a Phy. point of view; & all point to the necessity with plants of regular or occasional [union] between distinct individuals of the same species.—

If these remarks are of the least value to you, with respect to the communication you can of course use them4

[Many thanks] for note.— I received Report & I forward to Hildebrand copy of his paper.—5

I am at present so busy that I have no time to carefully examine the interesting specimen which you have kindly sent me & which I return. From the remarkable fact, lately ascertained by Dr. H. that with many orchids the ovules do not become developed until many weeks or even months after the pollen-tubes have penetrated the stigma, it is not a little difficult to ascertain whether an orchid [four words illegible] [whether] the abortion of the female organs has started.6 Of course there is no difficulty in ascertaining the rudimentary condition of the pollen.

ADraft

1
The date is established by the relationship between this letter and the letter from M. T. Masters, 28 March 1867, and by the fact that a finished version of the first paragraph of the letter was published in the Gardeners’ Chronicle, 6 April 1867 (Collected papers 2: 134–5).
2
With his letter of 28 March 1867, Maxwell Tylden Masters had enclosed a letter from A.D.B. to the Gardeners’ Chronicle and included specimens. Though A.D.B.’s letter only mentions sending barren seed-capsules of Cypripedium insigne flowers crossed with flowers from other species, the specimens may have been labelled differently, or else CD assumed that the author had also placed pollen from C. insigne stamens on the stigma of the same flower, and on the stigmas of flowers from the same plant.
3
CD refers to cases reported to him by John Scott, Fritz Müller, and others; he reported on them in Variation 2: 133–5. See Correspondence vol. 12, letter from John Scott, 28 March 1864, Correspondence vol. 14, letter from Fritz Müller, 1 December 1866, and this volume, letters from Fritz Müller, 1 January 1867 and 2 February 1867; see also letter to Fritz Müller, 7 February [1867] and n. 6.
4
See letter from M. T. Masters, 28 February 1867, n. 2.
5
See letter from M. T. Masters, 28 February 1867 and n. 4; the references are to the report, International Horticultural Exhibition 1866, Friedrich Hildebrand, and Hildebrand 1866a.
6
CD refers to data presented in Hildebrand 1863 and 1865; there are lightly annotated copies of these papers in the Darwin Pamphlet Collection–CUL. CD reported Hildebrand’s results in Variation 1: 402–3, ‘Fertilization of orchids’, p. 153, and Orchids 2d ed., p. 172. See also Correspondence vol. 11, letter from Friedrich Hildebrand, 16 July 1863, and Correspondence vol. 14, letter to Fritz Müller, 25 September [1866].

Manuscript Alterations and Comments

to me] interl
little] after del ‘no’
taken] interl
now] after del ‘know’
know of] interl
but] after del ‘(proved to be good [interl ‘as in the’ illeg] by fertilising other individuals or other species)’
easily] interl
pollen taken from] interl
of the same species, from] interl
quite] interl
a process or] interl
If] after del ‘(You can if you think fit make any use of these remarks)’
value] above del ‘use’
with … communication] interl
to] interl
copy of his] interl
no] point omitted before
carefully] above del ‘dissect’ in pencil
interesting specimen] in pencil above del in pencil ‘ovaria’
remarkable] after del ‘very’
do not] interl after del ‘first’
until] interl
even] interl
ascertain] after del ‘distinguish *by dissection the female [interl] *or male [pencil] the sexes of Orchids.—’
these plants] above del ‘orchids’

Please cite as “DCP-LETT-5468,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5468