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Letter 4235

Becker, L. E. to Darwin, C. R.

8 July [1863]

    Summary Add

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    Sends seeds of female Lychnis diurna; has found none in hermaphrodites.

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    On variation, hybridity, and inheritance of parasites in this plant.

Transcription

Altham | Accrington

July 8th.

Dear Sir

I send you some seed of Lychnis diurna gathered in Altham woods. You will probably not be surprised to learn that I have hitherto been unable to obtain a single capsule of seed from an hermaphrodite flower. I have examined, I should think, hundreds of plants, and find, that invariably, the oldest capsules, corresponding in age to those which in the female plants, have already ripened their seed, are shrivelled up to nothing. Many of the younger capsules seem so fresh and healthy, (though none are so vigorous as on the female plants,) that I cannot help fancying they may come to something, but I have never discovered a good one at all approaching maturity. I will continue to watch the plants carefully, and should I obtain seed from the hermaphrodites I will not fail to send you some.

I was prevented by wet weather from going to the woods as soon as I wished to mark the plants, and those I at length ticketed have scarcely ripened their seed, but I entertain no shadow of a doubt, from the appearance of the capsules and the remains of the styles, that all the seed sent is from female plants. It was gathered in a wood abounding in hermaphrodites which seem to be nearly if not altogether barren an<d> it may possibly interest you to try whether they will produce hermaphrodites when sown in another locality. I send it now, as I have an impression that in order to have flowers next spring, it is advisable to sow it so that they young plants may get well grown before winter. I observe a considerable variation in the form of the capsules, these are usually nearly globular, but some plants have them shorter others longer than the average. The elongation is occasionally carried so far as to seem like an imitation of the allied genus Cerastium   I have put in separate papers a few capsules shewing the extreme forms, and I intend to try whether the peculiarities are hereditary, as well as constant in the individual, and can be perpetuated or increased by selection.

In your last letter you say that the pale colour of some of the flowers leads you to suppose that the white Lychnis may grow in the same wood, and that the hermaphrodites may be natural hybrids. But in Professor Babington: ``Manual'' it is stated that both Lychnis diurna and vespertina vary in colour from red to white and from white to red. I could have gathered a bunch in our woods, shaded through every tint from rich rose to pure white, which would have admirably illustrated this remark as regards diurna, but the whitest of them all did not make the slightest approach, in any other character than colour, to the genuine White Lychnis, which I have never seen growing in this district. And whenever I have been fortunate enough to meet with this very interesting and rather scarce plant, it did not grow in woods, but in open fields or hedges. Since I received your letter I have looked more particularly for it, but in vain.

It therefore seems as if we must look to another cause for the hermaphrodites, and there seems nothing but to attribute it to the parasite. You say, adding the perfectly useless caution not to trust you on the point that the fungus may exist in the tissues of the plant and be propagated in the seed   I could not, if I tried, help believing that this is so though I am at a loss to comprehend how the propagation is accomplished   The female plants appear thoroughly free from the parasite while the infected plants seem incapable of producing seed, and their pollen you have found to be entirely destroyed by the fungus. Is it possible that the spores of the fungus may fall on the stigma and be conveyed along with the healthy pollen tube to the ovules? They must get into the tissues of the plant in some way as the fungus is found in the immature, unopened buds and I cannot do<ubt> the correctness of your suspicion that it destroys the pollen and causes the development of the ovarium in some, though not in nearly all of the infected plants—

I hope you will be indulgent with me for presuming to write you so long a letter and believe me to be | yours most respectfully | L. E. Becker

    Footnotes Add

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    f1 4235.f1
    The year is established by the relationship between this letter and the letter from L. E. Becker, 28 May [1863].
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    f2 4235.f2
    See letter from L. E. Becker, 28 May [1863].
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    f3 4235.f3
    CD's letter has not been found. For CD's interest in the relationships between the different species of Lychnis, and the possibility of several supposed species being mere varieties, see Correspondence vol. 5.
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    f4 4235.f4
    Babington 1862, pp. 52--3.
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    f5 4235.f5
    See letter from L. E. Becker, 28 May [1863]. Becker gave a more detailed explanation of these phenomena in Becker 1869. See also letter from L. E. Becker, 14 October 1869, Calendar no. 6937.
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