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Letter 3688

Gray, Asa to Darwin, C. R.

18–19 Aug 1862

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    Notes and observations on orchids.

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Cambridge. [Massachusetts]

Aug. 18. 1862

My Dear Darwin

The dawn of hope in yours of July 23d, so brightened in your last, of the 28th gave us heart-felt joy. Thank God your dear boy is convalescent, by this time, we trust so decidedly so as to give you full relief from all anxiety. Really, if one can give so much satisfaction at so cheap a rate, one would become a stamp collector for the purpose of supplying the good fellow.

When he gets quite well he is to write me a note and let me know what American stamps he lacks, and I will see that some of our young people help him. Tell him that so far, he is not so much indebted to the Harvard professor as to a venerable French gentleman of Philadelphia, Mr. Durand.—aged something like 75.

I have lost the time in which I was to write you this week.—and can send only a hasty line. My old friend Dr. Torrey is expected to-morrow to visit us for several days, and I must clear up matters before his coming. But I shall scold him for not having supplied me with Specularia perfoliata, with the ``precociously fertilized flowers''. (It seems a good term,—it express the fact.)

Since my last a few Orchids have come in, e.g. our White Fringed Orchis P. blephariglottis.—but rather too old,—and while I was out, after sunset, a friend has brought me P. ciliaris—the Yellow Fringed O.— which I shall look at to-morrow.

I will record notes, and try to put on record the most important,—so it will not be worth while to send you so many details in the raw state.

If you so wish it, perhaps I may make a note of some obs. elsewhere— But I like to stick such things into my Notices & Reviews. No matter if they are overlooked by the outsiders. If you know of them, or any one else who really wants to use such observations, that is all I care. I rather like to stick these farthing candles under the bushel,—and the same of larger lights, to a degree.

The Sept. no. of Sill. Jour is so delayed that your enclosures were back in time. I was sitting down to use them, when Silliman wrote me that I had already sent him more matter than he could print.

And so, I was not sorry to let the Orchids go by till the Nov. no.—where I hope to use the cuts you sent me, and give some gossiping observations on several American orchideæ. But these must be regarded as only rapid reconnaisance.— All should be held subject to confirmation or the reverse by more careful & reiterated observations—

But I have two points, and both, I know, will please you.

1. Goodyera repens. Before reading your remark on p. 114 line 11, —i.e. having forgotten it.—I have confirmed it. It is very distinct, the difference between the early position when the proboscis must hit gland & remove pollinia, but cannot thrust pollinia down to stigma.—and the later position, as seen in flowers lower down the spike. Where there is room, the stigma is in sight on looking down the flower, and the pollinia on a pin go down to stigma as sure as can be.— But the difference is only slightly, if at all owing to any downward movement of the labellum.; it comes from a backward movement of the column, which becomes more erect.

2. I have another, and a different case of close-self-fertilization,—in Gymnadenia tridentata. The arrangement different from P. hyperborea,— and indeed, I do not see just how the pollen so surely gets on to the stigmas—on to an arm of stigma carried up each side of anther, & one between the cells. But they get pollen packets in the bud, and pollen-tubes are emitted abundantly.— It is most interesting case yet.—such determination to self-fertilize and yet I suspect pollinia are often removed by insects, & cross-fertilize occasionally. I will describe this. But it must be looked at more particularly next year.

19th | The charm of Platanthera ciliaris & blephariglottis is—the very long & narrow arms to the stigma, which, with the anterior portion of the anther containing the long caudicle, are like a stalk bearing the (small) disk on the extremity.— these thrust forward to meet the head of insect, who cannot get in the whole length of proboscis in to the long (114 inch) straight spur, before his face will come in to contact with the glands.

Unfortunately for my experiments, the little glands, so far projecting, dry up sooner than usual, & loose their viscidity, & the stalk its power of depression.

The slight differences between the two species—the white and the yellow—are interesting; but I will not trouble you now, as I keep notes on them.

Torrey is here. He tells me he could not find any pollen-tubes emitted from Specularia perfoliata— the early fertilised flowers—while the pollen was still in the anthers.

Good bye, in haste, Ever Yours | A. Gray

    Footnotes Add

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    f1 3688.f1
    Gray refers to Leonard Darwin's gradual recovery from scarlet fever (see letters to Asa Gray, 23[--4] July [1862] and 28 July [1862]).
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    f2 3688.f2
    At CD's request, Gray had sent a number of stamps from the United States for Leonard's collection (see letter to Asa Gray, 10--20 June [1862], and letters from Asa Gray, 2--3 July 1862, 15 July [1862], and 21 July 1862). See also letters to Asa Gray, 23[--4] July [1862] and 28 July [1862].
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    f3 3688.f3
    Gray refers to the botanist and pharmacist, Elias Durand. Gray was Fisher Professor of natural history at Harvard University.
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    f4 3688.f4
    Gray refers to John Torrey, his former mentor and botanical collaborator.
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    f5 3688.f5
    In his letter to CD of 2--3 July 1862, Gray promised to obtain specimens of this species from Torrey, and to observe the behaviour of the pollen-tubes in those flowers that underwent `precocious fertilization' (later known as cleistogamy). In reply, CD commented that the phenomenon seemed `too remarkable to be called ``precocious flowering''' (letter to Asa Gray, 23[--4] July [1862]).
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    f6 3688.f6
    Platanthera blephariglottis and P. ciliaris are described in A. Gray 1862b, p. 424.
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    f7 3688.f7
    In the letters to Asa Gray, 23[--4] July [1862] and 28 July [1862], CD argued that Gray's observations on American species of orchids were too good to be reported only in a review of Orchids, and that Gray should publish at least some of them separately.
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    f8 3688.f8
    Gray refers to his notes on American species of orchids, returned by CD with the letter to Asa Gray, 23[--4] July [1862]. Gray intended to include some of his observations in a follow-up article to his review of Orchids (A. Gray 1862b), to be published in the monthly American Journal of Science and Arts, edited by Benjamin Silliman Jr, and commonly referred to as `Silliman's journal'.
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    f9 3688.f9
    CD had arranged, at Gray's request, for John Murray to send Gray electrotype plates of three of the illustrations from Orchids, figuring Orchis mascula and O. pyramidalis, for reproduction in Gray's review of the book (A. Gray 1862a; see letter from Asa Gray, 18 May 1862, and letter to Asa Gray, 10--20 June [1862]). The plates arrived too late for use in Gray's review (see letter from Asa Gray, 21 July 1862 and nn. 3 and 4), but appeared in the follow-up article, published in the November number of the American Journal of Science and Arts (A. Gray 1862b).
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    f10 3688.f10
    In Orchids, p. 114, CD stated that in Goodyera repens the passage into the flower between the rostellum and labellum was contracted. He reported that, by analogy with Spiranthes autumnalis, he suspected the labellum moved `further from the column in mature flowers, in order to allow insects, with the pollinia adhering to their heads or probosces, to enter the flower more freely.' Gray gave his observations on this point in A. Gray 1862b, p. 427; CD cited Gray's confirmation of his view in `Fertilization of orchids', p. 151 (Collected papers 2: 148).
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    f11 3688.f11
    Gray sent CD notes on Platanthera hyperborea with his letter of 2--3 July 1862; although the notes have not been found, it is clear from CD's response in the letter to Asa Gray, 23[--4] July [1862], that Gray had told him that the species was often self-pollinated. In Orchids, one of CD's purposes was to demonstrate that the `main object' of the various `contrivances by which Orchids are fertilised' was cross-fertilisation (p. 1), and he noted only one exception (p. 359). CD included P. hyperborea and Gymnadenia tridentata on an undated list of `self-fertilisers' that is now in DAR 70: 167; he also included a modified discussion of the occurrence of `self-fertilisation' in orchids in Orchids 2d ed., pp. 288--93.
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    f12 3688.f12
    Gray discussed Gymnadenia tridentata in A. Gray 1862c, p. 260 n. and A. Gray 1862b, p. 426. CD made undated notes referring himself to the latter account (DAR 70: 8, 17); he cited Gray's observations in `Fertilization of orchids', p. 147 (Collected papers 2: 144).
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    f13 3688.f13
    See n. 6, above.
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    f14 3688.f14
    See nn. 4 and 5, above.
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