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Letter 5264

Müller, J. F. T. to Darwin, C. R.

[2 Nov 1866]

    Summary Add

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    Sends his observations on sterility of Eschscholzia,

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    on Oxalis,

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    and on recently found dimorphic plants.

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    Sends specimen of Hedyotis [see Forms of flowers, p. 133].


I alluded in one of my letters to the sterility of Eschscholtzia and some other plants, when fertilized with pollen from the same individual plant. I have at present in my garden one old large plant of Eschscholtzia, which for about six weeks is producing a large number of flowers, (just now I had them counted by my children, who tell me, there are to day 103), without yielding a single seed capsule. The stigmas of all the flowers, I examined, were covered with pollen-grains, which emitted their tubes; but never the tubes appeared to enter deeply the tissue of the stigmas.— Yesterday expanded the first flower of the present year's seedlings; I fertilized with its pollen two of the old plants flowers, and the seedlings flower with the old plants pollen, and now (24 hours after fertilization) I see, that the stigmas of these three crossed flowers behave very differently from those of all others; the stigmas of the latter (A) are diverging in a more or less horizontal direction, those <of the f>ormer (B) have become erected, <4 or 5 words missing> <    >ered.—


I fertilized also numerous <4 or 5 words missing> with pollinia from the same <4 or 5 words missing> a single seed-capsule. On the <3 or 4 words missing> <fer>tilized with the very same flowers pollinia is yielding a seed-capsule.

During the last month I have been very fortunate in enlarging the list of our dimorphic plants,—adding once in half an hour four new species (Cordia, Oxalis, Hedyotis Villarsia).

But before passing to the new species, allow me some more remarks on the dimorphic Oxalis, of which I told you in my last letter. How could this species by natural selection arrive to the extremely miserable estate of its male reproductive system, the anthers of one form being in most cases perfectly steril, while those of the other form also contain much aborted pollen? Perhaps the question might be answered in the following way: The plant producing an uncommonly large number of bulbilli, natural selection might have been less severe regarding the sexual reproduction. The anthers of the one form, one set of which equals in length the pistils, might have been rendered steril by natural selection, to prevent self-fertilization. (Thus, for instance, in some Malpighiaceae those anthers, which would be able to fertilize without the intervention of insects, the own flowers stigmas, have become barren). Lastly the partial barrenness of the anthers of the other form might have been inherited from the form with barren anthers. I feel not quite sure, whether this answer will do.— At all events the plant will offer far more difficulty to those who look at species as perfect productions of a supreme intelligence.

Now to the recently found dimorphic plants of our flora. <diagram excised>

1, a second of Cordia.

2, a frutescent Oxalis (alread<y> alluded to in my last letter). The species is probably trimorphic. I observed but two plants, growing close together, one being long-styled and the other short-styled, both yielding plenty of seed-capsules.

[DIAG HERE (actually specimens). Headed `Frutescent Oxalis', with `short-styled' and `long-styled' below 4 and 2 pressed-flowers respectively.]

3, a Plumbago, from the continent. I saw but two plants, from which I brought home about half a dozen of long-styled and as many short-styled ears. These continued to yield fresh flowers for about a week. The length of the styli of the long- styled form <4 or 5 words missing> <v>ariable, while in the short-sty<led> <4 or 5 words missing> <s>tigmas & each is rather variable. <4 or 5 words missing> <s>ame level with the anthers; but <4 or 5 words missing> <rea>ch even to their bases, while in other cases they project beyond the anthers, but never so far as the stigmas of the long-styled flowers do. There is no difficulty in distinguishing the two forms. I may add, that a Plumbago with pale-blue flowers is frequently to be met with in the gardens of Desterro; this is always pro<pag>ated by cuttings and never seeds here (as far as <three quarters of page missing>

6, a small Hedyotis. The pollen-grains are larger in the short-styled form. <diagram excised>

Villarsia is, as you know, an aquatic plant; the Hedyotis grows in wet sand near the edge of small fresh-water pools. Both the dimorphic and trimorphic Oxalis are preferring humid places, whereas our monomorphic Oxalis is to be found even in so dry and barren places as the fissures of a naked rock. All this confirms the view, you suggested, of aquatic and marsh-plants being more liable, than others, to dimorphism.

<three quarters of page missing>

Als ich heute einen Franzosen, Herrn Hippolyte Gautier, besuchte, der Orchideen zum Verkauf sammelt, sah ich in seinem Garten eine schöne blaue Ipomoea. Er erzählte mir, er habe eine einzige Pflanze gezogen aus Samenkörnern, die er aus den nördlichen Provinzen Brasiliens erhalten hätte; diese Pflanze blühte einige Jahre schon sehr reichlich und brachte Blumen in grosser Zahl fast das ganze Jahr hindurch, ohne jedoch Samenkapseln zu liefern. Ich dachte natürlich, die Pflanze möchte dimorph sein, und fand bei Untersuchung der Blumen, dass der Griffel weit über die Ebene der Staubgefässe hinausragte. Wir haben hier, auf dem Festlande, eine nahe verwandte Art, welche ich vielleicht nächsten Monat untersuchen kann.

Bei der Untersuchung der dimorphen Blumen unseres gemeinen Erythroxylon (``Fruta de pomba'') war ich überrascht von der Verschiedenheit, welche ein kurzgriffliger Baum in den einzelnen Blüthentheilen darbot.

Unter 253 Blumen dieses Baumes hatten:

5 sepala, 5 petala, 10 stamina, 3 styli, 192 Blumen 5 "  6 "  10 "  3 "  1 "  1) 6 "  6 "  10 "  3 "  3 " 6 "  6 "  11 "  3 "  3 " 6 "  6 "  12 "  3 "  20 " 6 "  6 "  12 "  3--4 "  1 "  2) 6 "  6 "  12 "  4 "  25 " 6 "  7 "  12 "  3 "  1 " 6 "  7 "  13 "  4 "  1 " 6 "  7 "  14 "  3 "  1 " 7 "  7 "  12 "  3 "  1 " 7 "  7 "  12 "  4 "  1 " 7 "  7 "  14 "  3 "  1 " 7 "  7 "  14 "  3--4 "  1 "  2) 7 "  7 "  14 "  4 "  2 " 1) Eines der sepala war an der Spitze gekerbt. 2) Einer der drei styli war doppelt so dick als jeder der beiden andern und mit einem zweilappigen stigma versehen.

Von den Blumen mit vier Griffeln hatten zehn zwei Ovula. Unter zahlreichen Blumen von anderen kurz- und langgriffligen Bäumen fand ich nur eine einzige kurzgrifflige mit sechs Kelch-, sechs Blumenblättern, zehn Staubfäden und drei Griffeln und eine langgrifflige mit 4 Kelch-, 4 Kronenblättern, 8 Staubgefässen, 4 Griffeln und keinem Ovulum.

Aber ich fürchte, Ihre Geduld schon erschöpft zu haben und will schliessen und einen Fall von merkwürdiger Veränderlichkeit des Kelches, den ich bei einer Hillia beobachtete, für einen andren Brief versparen.

Erlauben Sie, dass ich Ihnen noch einmal herzlich für Ihren freundlichen Brief und die ``Origin'' danke, und glauben Sie, dass ich, werther Herr, mit aufrichtiger Hochachtung treulichst der Ihrige bin | Fritz Müller.

P. S. Habe ich Ihnen schon mitgetheilt, dass ich einen unterirdischen Käfer fand, dem die Tarsen an allen Füssen fehlen?


Today, when I visited a Frenchman, Mr Hippolyte Gautier, who collects orchids for sale, I saw a beautiful blue Ipomoea in his garden. He told me he had raised a single plant from seed that he had received from the northern provinces of Brazil; this plant had already flowered for some years, very abundantly, and had large numbers of blooms throughout the year, without, however, producing seed capsules. I naturally thought the plant could be dimorphic, and found, upon investigation of the flowers, that the style projected far above the stamens. We have here on the mainland a closely related species which I can probably examine next month.

While investigating the dimorphic flowers of our common Erythroxylon (``Fruta de pomba'') I was amazed by the variation presented in every flower part in a short-styled tree.

Out of 253 flowers on this tree there were:

5 sepala, 5 petala, 10 stamina, 3 styli, 192 flowers 5 " 6 " 10 " 3 " 1 " 1) 6 " 6 " 10 " 3 " 3 " 6 " 6 " 11 " 3 " 3 " 6 " 6 " 12 " 3 " 20 " 6 " 6 " 12 " 3--4 " 1 " 2) 6 " 6 " 12 " 4 " 25 " 6 " 7 " 12 " 3 " 1 " 6 " 7 " 13 " 4 " 1 " 6 " 7 " 14 " 3 " 1 " 7 " 7 " 12 " 3 " 1 " 7 " 7 " 12 " 4 " 1 " 7 " 7 " 14 " 3 " 1 " 7 " 7 " 14 " 3--4 " 1 " 2) 7 " 7 " 14 " 4 " 2 " 1) A few of the sepala were notched at the tip. 2) One of the three styli was twice as thick as each of the other two and had a bilobed stigma.

Of the flowers with four styles, ten had two ovula. Among numerous flowers of other short- and long-styled trees I found only a single short-styled with six sepals, six petals, ten filaments, and three styles, and one long-styled with 4 sepals, 4 petals, 8 stamens, 4 styles and no ovulum.

But I am afraid I've exhausted your patience and will close, and I will save for another letter a case of remarkable variability of the calyx that I observed in a Hillia.

Allow me to give you my heartfelt thanks once again for your friendly letter and the ``Origin'', and believe me, I am, dear sir, with sincere respect, very truly yours | Fritz Müller

P. S. Have I already told you that I found an underground beetle whose tarsi lacked any feet?

    Footnotes Add

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    f1 5264.f1
    The date is established by CD's annotations at the top of the letter and on the envelope in which part of it was found. The letter contained specimens attached to the page at various places. Some of these were cut out by CD, probably to be added to his `Dimorphic Portfolio', and have not been found (see n. 20, below). The letter text has been reconstructed from more than one source. The text in German is transcribed from Möller ed. 1915--20, 2: 93--4, Alfred Möller having translated the original English fragment, which has not been found. For an account of the reconstruction of Müller's letters to CD, see the letter from Fritz Müller, 13 February 1866, n. 1. Möller dated this fragment of the letter 1 October 1866, but CD's annotations as well as his reply of [late December 1866 and] 1 January 1867 refer to items mentioned only in this part of the letter (see n. 11, below). For a translation of the German portion of the letter, see Appendix I.
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    f2 5264.f2
    See letter from Fritz Müller, 2 August 1866.
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    f3 5264.f3
    See letter from Fritz Müller, 1 and 3 October 1866 and nn. 2--6.
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    f4 5264.f4
    In the family Malpighiaceae the presence of sterile as well as fertile stamens is common (Mabberley 1997).
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    f5 5264.f5
    Müller had sent CD specimens of two forms of another species of Cordia (see the letter from Fritz Müller, 1 and 3 October 1866 and n. 9). CD discussed Cordia in Forms of flowers, pp. 117--18, 253.
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    f6 5264.f6
    Frutescent: `having the appearance or habit of a shrub' (OED). Müller enclosed pressed specimens of both long-styled and short-styled forms of /Oxalis/ with this letter (DAR 142: 100 v.). He had mentioned his intention of examining an Oxalis with a woody stem in his letter of 1 and 3 October 1866.
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    f7 5264.f7
    CD had recently expressed the view that the pollen-grains from longer stamens in the short-styled forms of a wide variety of dimorphic plants usually were the largest (see letter to W. E. Darwin, 22 June [1866] and nn. 5 and 6). In Forms of flowers, pp. 249--54, CD discussed the relative size of pollen-grains in several heterostyled species.
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    f8 5264.f8
    In Forms of flowers, pp. 116, 133, CD discussed Villarsia and Hedyotis specimens that he received from Müller.
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    f9 5264.f9
    See letter to Fritz Müller, 23 May 1866 and n. 13.
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    f10 5264.f10
    This section of the letter, published in Möller ed. 1915--21, 2: 93--4, was dated 1 October 1866 by Möller, but is clearly part of the present letter (see n. 1, above). Hippolyte Gautier has not been further identified.
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    f11 5264.f11
    In his reply to Müller of [late December 1866 and] 1 January 1867, CD referred to Müller's observation of evidence for dimorphism in Ipomoea, calling it Convolvulus (in Cross and self fertilisation, p. 28, CD stated that in England Ipomoea purpurea was often called Convolvulus major).
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    f12 5264.f12
    `Fruta de pomba': fruit of the dove (Portuguese). In Forms of flowers, pp. 121--2, CD referred to the dried flowers of Erythroxylum (Erythroxylon was an alternative spelling) and included a sketch of the two forms that Müller had sent him. He also noted Müller's observations on the variation in the number of flower parts.
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    f13 5264.f13
    The observations on Hillia are in the letter from Fritz Müller, 1 December 1866.
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    f14 5264.f14
    See letter to Fritz Müller, 23 August [1866]. According to Müller's endorsement, he received the letter on 25 October 1866; in a letter to his brother Hermann Müller of 29 October 1866, he mentioned having just received a copy of the fourth edition of Origin (see Möller ed. 1915--21, 2: 95). CD's publisher, John Murray, had agreed to send out some copies before the general release of the new edition in mid-November 1866 (see letter from John Murray, 23 July [1866]).
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    f15 5264.f15
    In John Lindley's classificatory arrangement, the family Primulaceae is adjacent to the family Plumbaginaceae (see Lindley 1853, p. 641).
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    f16 5264.f16
    The section of the letter containing the reference to Pontederia aquatica has not been found. Most of the fourth page is missing. Müller's findings on Pontederia, collected over the next five years, were mentioned in Forms of flowers, pp. 183--6.
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    f17 5264.f17
    The genus Findlaya was placed in the family Primulaceae by Lindley (see Lindley 1853, p. 646), but is now placed in the Plumbaginaceae.
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    f18 5264.f18
    Sethia is now subsumed within Erythroxylum. CD's remarks on heterostyly in Sethia are in Forms of flowers, p. 122.
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    f19 5264.f19
    Müller's remarks on Gesneria were contained in a now missing part of the letter, but see the letter to Fritz Müller, [late December 1866 and] 1 January 1867 and n. 8.
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    f20 5264.f20
    The annotation refers to a portfolio of notes on dimorphism where CD may have kept specimens and sections of the letter that he cut out. CD kept a number of such portfolios, amassed over a long period of time and since dispersed. The likely contents of some portfolios were reconstructed when some of CD's papers were catalogued in 1932 (see DAR 220: 13), but part of that material has since been lost. Some of CD's extant notes on dimorphism are in DAR 108--11, including one fragment of this letter. A list of species, including representatives of many genera mentioned in this letter and containing information on relative pollen-grain sizes of long-styled and short-styled forms is in DAR 111: 34.
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