From Fritz Müller¹ 17 July 1867

Itajahy, Santa Catharina,

17. Juli 1867.

.... . Ich muss Sie noch um Verzeihung bitten, dass ich Ihnen nicht früher für Dr. Hildebrand’s Buch über die Befruchtung gedankt habe, welches Sie mir freundlichst zuschickten. Ich habe es mit grossem Interesse gelesen. Ich bekam auch Dr. Hooker’s höchst interessante Schrift “Vorlesung über Insel-Floren”.²

Die Familie der Rubiaceen scheint sehr reich an dimorphen Pflanzen zu sein; obwohl jetzt im Winter viel weniger Pflanzen blühen, wie zu irgend einer andern Jahreszeit, so bemerkte ich doch schon wieder drei dimorphe Arten: 1) eine zierliche etwa Erica ähnliche Hedyotis, 2) eine zweite Art von Suteria mit braunem Kelch und gelber Krone, von der man sagt, sie sei das Lieblingsfutter des Tapirs, 3) die Manettia bicolor, welche hier sehr häufig ist.³ Ich kenne zwei andere Arten von Manettia mit rothen Blüthen, von der ich vermuthe, dass sie auch dimorph ist, obwohl alle Pflanzen, die ich bisher beobachtete, langgrifflig waren.

Ich fand hier auch eine weisse trimorphe Oxalis; ich habe verschiedene kurzgrifflige und mittelgrifflige, bisher aber noch keine langgrifflige gesehen; eine einzige Pflanze hatte die Staubfäden der langgriffligen Form in Verbindung mit den Griffeln der mittelgriffligen, so dass die Griffel dieselbe Länge hatten, wie die längeren Staubfäden.⁴

Ehe ich Desterro verliess,⁵ untersuchte ich die meisten Kapseln, die ich aus Kreuzungsversuchen von Orchideen erhalten hatte; die meisten waren noch unreif.⁶ Beinahe alle Samen waren offenbar gut in den Kapseln von:

Cattleya intermedia ♀ und Cattl. elegans⁷ ♂

Epidendrum vesicatum ♀ und Ep. raniferum ♂

" " ♀ und Ep. glumaceum⁸ ♂

" raniferum ♀ und Ep. cinnabarium ♂

" " ♀ und Brassavola fragans Leon⁹ ♂!

Cirrhaea saccata (?) ♀ und Cirrhaea dependens (?)¹⁰ ♂

Oncidium micropogon ♀ und Gomeza¹¹ sp. ♂

Gomeza sp. ♀ und Oncidium micropogon ♂.

Es waren viel mehr gute Samen als schlechte Samen in den Kapseln von:

Cattleya elatior var. Leopoldi ♀ und Laelia purpurata ♂.

" intermedia ♀ und Cattl. elatior var. Russeliana ♂.¹²

Ungefähr die Hälfte der Samen war offenbar gut in einer Kapsel von:

Cattleya elatior ♀ befruchtet mit Cattl. intermedia ♂.

Wenigstens $\frac{9}{10}$ der Samen waren schlecht in den Kapseln von:

Cattleya elatior ♀ gekreuzt mit Cattl. elegans ♂ und

Oncidium (aus Theresopolis)¹³ ♀ gekreuzt mit Sigmatostalix ♂.

Eine ausserordentlich kleine Zahl von offenbar guten Samen wurde gefunden in den Kapseln von:

Cattleya elatior var. Russeliana ♀ und Epidendron cinnabarinum ♂

Notylia sp. ♀ und Ornithocephalus sp. ♂ (!).¹⁴

Alle Samen waren schlecht in den Kapseln von:

Cattleya elatior ♀ und Epidendron¹⁵ Schomburgkii (?) ♂

Epidendron vesicatum ♀ und Epid. Schomburgkii (?) ♂

" " ♀ und Epid. cinnabarinum ♂

Sigmatostalix sp. ♀ und Ornithocephalus sp. ♂.

Bei einer selbstbefruchteten Kapsel von Ornithocephalus fand ich, dass sie viel kleiner war und viel mehr schlechte Samen enthielt als eine andere Kapsel, die mit Pollen einer fremden Pflanze befruchtet war.... .

Was Ihre Frage über Geschlechtsverschiedenheiten bei niederen Thieren betrifft, so mag vielleicht eine unserer Amphipoden, Brachyscelus diversicolor F.M.,¹⁶ hier zu nennen sein. Das Männchen dieser Art, welche auf einigen unserer grösseren Acalepheen lebt (Rhizostoma cruciatum Less. = Rhacopilus cruciatus und cyanolobatus Agass. und Chrysaora Blossevillei Less. = Lobocrocis Blossevillei Agass.),¹⁷ unterscheidet sich nicht nur durch seine Antennen, deren erstes Paar sehr dick und reichlich mit Riechhaaren versehen ist, während das zweite ausserordentlich lang ist (dies zweite Paar fehlt den ♀ und den jungen ♂)—sondern auch durch seine Farbe. Das Weibchen ist gewöhnlich von milchweisser oder mattgelblicher Farbe, das Männchen dunkelröthlich-braun oder schwärzlich. Die Art hat aussergewöhnlich grosse Augen, wie in der That die meisten Hyperina sie haben, und so ist es nicht unwahrscheinlich, dass das Weibchen durch die Farbe des Männchens angezogen wird.

Bei dieser Gelegenheit will ich hinzufügen, dass es im Meere bei Santa Catharina einen Fisch giebt, der sehr melodische Töne hervorbringt, welche auch dazu dienen mögen, das andere Geschlecht anzulocken.¹⁸ Die Töne klingen wie entferntes Geläute von Kirchenglocken. Ich habe sie nur an ruhigen Abenden gehört, wenn diese Seemusikanten um einen Felsen dicht bei der Küste schwammen, aber ich sah den Fisch nie.

Um noch einmal auf das Epidendron mit seitlichen fruchtbaren Antheren zurückzukommen, bei dem Pollenschläuche sogar noch vor dem Oeffnen der Blüthe getrieben werden, so scheint die grosse Veränderlichkeit der seitlichen Antheren, welche in einem Falle beobachtet wurde, der Ansicht günstig zu sein, dass sie erst neuerdings erworben wurden in Folge eines zufälligen Rückschlags auf einen längst verlorenen Character.¹⁹

Mit der grössten Hochachtung, glauben Sie, dass ich, werther Herr, aufrichtigst der Ihrige bin | Fritz Müller.

Footnotes

For a translation of this letter, see Correspondence vol. 15, Appendix I. All Fritz Müller’s letters to CD were written in English (see Möller ed. 1915–21, 2: 72 n.); most of them have not been found. Many of the letters were later sent by Francis Darwin to Möller, who translated them into German for his Fritz Müller: Werke, Briefe und Leben (Möller ed. 1915–21). Möller also found drafts of some Müller letters among Fritz Müller’s papers and included these in their original English form (ibid., 2: 72 n.). Where the original English versions are missing, the published versions, usually appearing in German translation, have been used.

The references are to Hildebrand 1867a and J. D. Hooker 1866a (see letters to Fritz Müller, 25 March [1867] and 22 April [1867]).

In Forms of flowers, pp. 131–3, 135, CD reported Müller’s information on heterostyly in Hedyotis, Suteria, and Manettia bicolor. Suteria is now subsumed within the genus Psychotria; M. bicolor is a synonym of M. luteo-rubra.

CD mentioned Müller’s observation of a white-flowered trimorphic Oxalis in Forms of flowers, p. 180.

Müller had lived in Destêrro (now Florianópolis) from 1856, but had just returned to live on the Itajahy (now Itajaí) river near Blumenau, where he bought a new property in September 1867. Müller typically gave his address simply as ‘Itajahy’ until the mid-1870s, when he began to add ‘Blumenau’, but only consistently gave his address as ‘Blumenau’ from 1878 (Möller ed. 1915–21, 3: 94; see also West 2003, pp. 149–50).

Müller had begun a series of crossing experiments with orchids earlier in the year (see letter from Fritz Müller, 1 April 1867).

Cattleya elegans is an orchid hybrid, a cross of C. tigrina and C. purpurata.

Epidendrum raniferum is a synonym of E. cristatumEpidendrum glumaceum is a synonym of Prosthechea glumacea (see Higgins 1997, p. 378).

Brassavola fragans (named by Charles Lemaire; Möller mistranscribed ‘Lem’ as ‘Leon’) is a synonym of B. tuberculata.

Cirrhaea dependens is a synonym of C. viridipurpurea.

Gomeza is a synonym of Gomesia.

Cattleya elatior is a synonym of C. guttata; the varieties mentioned by Müller are now C. guttata var. leopoldii and C. guttata var. russelliana. Laelia purpurata is a synonym of Cattleya purpurata.

Now Queçaba (West 2003).

Müller probably found it surprising that a cross between two fairly widely separated genera was possible. In orchids, natural hybrids are usually confined to intergeneric crosses within a subtribe, making a cross at this level rare (see Dressler 1981, pp. 147–8). Notylia is now a member of the orchid tribe Cymbidieae, while Ornithocephalus belongs to the tribe Maxillariae.

‘Epidendron’: a mistranscription of Epidendrum.

For CD’s query, see the letter to Fritz Müller, 22 February [1867]. The name Brachyscelus diversicolor was never published by Müller. For a description of all currently recognised species within the genus, see Vinogradov et al. 1996, pp. 488–96. Müller had discussed sexual differences in the antennae of Brachyscelus in F. Müller 1864, p. 53 (see also Dallas trans. 1869, pp. 78–9; CD annotated this section in his copy; see Marginalia 1: 609).

Rhacopilus cyanolobatus and Rhizostoma cruciata are both synonyms of Catostylus cruciatus (Kramp 1961, p. 370). Chrysaora blossevillei is now considered to be a doubtful species (Kramp 1961, p. 324). Two species of Chrysaora have been recorded in Brazil, C. lactea and C. plocamia (Migotto et al. 2002, p. 23). It is likely, because of its size, that the species Müller refers to is C. plocamia.

The fish has not been identified, but of thirty-four possible sound-producing species in the families Batrachoididae and Sciaenidae in Brazil, the Bocon toadfish, Amphichthys cryptocentrus, is the only reef-associated species known to occur at depths of a metre or less (Joseph Luczkovich, personal communication). CD mentioned musical sounds made by fish in Descent 2: 23, 331 (see also Pauly 2004, pp. 193–4).

Müller first mentioned this orchid in a letter of 1 June 1866 that has not been found (see Correspondence vol. 14, letter to Fritz Müller, 23 August 1866). He gave an account of it in letters to Max Johann Sigismund Schultze (2 June 1866) and Hermann Müller (1 July 1866; the letters are reproduced in Möller ed. 1915–21, 2: 83–4, 86–9. Müller described it as a species of the orchid tribe Epidendreae with three fertile anthers, two in the outer whorl and one in the inner whorl (see Möller ed. 1915–21, 2: 87–8). He later published his observations in F. Müller 1868a, 1869, and 1870; CD added a reference to Müller’s work in Orchids 2d ed., p. 148.

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

Dressler, Robert L. 1981. The orchids: natural history and classification. Cambridge, Mass., and London: Harvard University Press.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

Higgins, Wesley E. 1997. A reconsideration of the genus Prosthechea (Orchidaceae). Phytologia 82: 370–83.

Kramp, Paul Lassenius. 1961. Synopsis of the medusae of the world. Special volume of Journal of the Marine Biological Association 40.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Orchids 2d ed.: The various contrivances by which orchids are fertilised by insects. By Charles Darwin. 2d edition, revised. London: John Murray. 1877.

Pauly, Daniel. 2004. Darwin’s fishes. An encyclopedia of ichthyology, ecology, and evolution. Cambridge: Cambridge University Press.

West, David A. 2003. Fritz Müller. A naturalist in Brazil. Blacksburg, Va.: Pocahontas Press.

Translation

From Fritz Müller¹ 17 July 1867

Itajahy, Santa Catharina,

17. July 1867.

. . . . I have to apologise for not thanking you earlier for kindly sending me Dr. Hildebrand’s book on fertilisation. I have read it with great interest. I have also received Dr. Hooker’s extremely interesting publication “Lecture on insular floras”.²

The family Rubiaceae seems to be very rich in dimorphic plants; although now in winter many fewer plants are flowering than in any other season, I still observed yet another three dimorphic species: 1) a delicate Hedyotis somewhat similar to Erica, 2) a second species of Suteria with brown calyx and yellow corolla, which is said to be the favourite food of tapirs, 3) the Manettia bicolor, which is very common here.³ I know another two species of Manietta with red flowers, which I suspect are also dimorphic, although all the plants that I have observed so far were long-styled.

I have also found a trimorphic white Oxalis here; I have seen various short-styled and medium-styled but no long-styled yet; a single plant had the stamens of the long-styled one in conjunction with the styles of the medium-styled ones, so that the style was as long as the longest stamens.⁴

Before leaving Desterro,⁵ I examined most of the capsules that resulted from my crossing experiments with orchids; most had not yet matured.⁶ Almost all seeds were apparently good in the capsules of:

Cattleya intermedia ♀ and Cattl. elegans⁷ ♂

Epidendrum vesicatum ♀ and Ep. raniferum ♂

" " ♀ and Ep. glumaceum⁸ ♂

" raniferum ♀ and Ep. cinnabarinum ♂

" " ♀ and Brassavola fragans Leon⁹ ♂!

Cirrhaea saccata (?) ♀ and Cirrhaea dependens (?)¹⁰ ♂

Oncidium micropogon ♀ and Gomeza¹¹ sp. ♂

Gomeza sp. ♀ and Oncidium micropogon ♂

There were many more good than bad seeds in the capsules of:

Cattleya elatior var. Leopoldi ♀ and Laelia purpurata ♂

" intermedia ♀ and Cattl. elatior var. Russeliana ♂.¹²

Approximately half the seeds were apparently good in the capsule of:

Cattleya elatior ♀ fertilised with Cattl. intermedia ♂.

At least $\frac{9}{10}$ of the seeds were bad in the capsules of:

Cattleya elatior ♀ crossed with Cattl. elegans ♂ and

Oncidium (from Theresopolis)¹³ ♀ crossed with Sigmatostalix ♂.

An extraordinarily small number of apparently good seeds were found in the capsules of:

Cattleya elatior var. Russeliana ♀ and Epidendrum cinnabarinum ♂

Notylia sp. ♀ and Ornithocephalus sp. ♂ (!)¹⁴

All seeds were bad in the capsules of:

Cattleya elatior ♀ and Epidendron¹⁵ Schomburgkii (?) ♂

Epidendron vesicatum ♀ and Epid. Schomburgkii (?) ♂

" " ♀ and Epid. cinnabarinum ♂

Sigmatostalix sp. ♀ and Ornithocephalus sp. ♂.

I found a self-fertilised capsule of Ornithocephalus was much smaller and contained many more bad seeds than another capsule fertilised with the pollen from a different plant.... .

With regard to your query about sexual differences in lower animals, one ought perhaps to mention one of our amphipods, Brachyscelus diversicolor F.M.¹⁶ The male of this species, which lives on some of our larger acalephs (Rhizostoma cruciatum Less. = Rhacopilus cruciatus and cyanolobatus Agass. and Chrysaora Blossevillei Less. = Lobrococis Blossevillei Agass.),¹⁷ differs not only in the antennae, the first pair of which is very thick and covered in olfactory hair whereas the second is extraordinarily long (this second pair is absent on the ♀ and young ♂)—but also in colour. The female is usually milky white or dull yellowish, the male is dark reddish-brown or blackish. The species has unusually large eyes, as indeed most Hyperina have, and so it is not unlikely that the female is attracted by the colour of the male.

In this connection I would like to add that there is a fish in the sea by Santa Catharina that produces very melodious sounds that may also serve to attract the opposite sex.¹⁸ The sounds are like the ringing of distant church bells. I have only heard them on quiet evenings when these maritime musicians swam by a rock close to the coast, but I never saw the fish.

To come back once more to the Epidendron with fertile lateral anthers, in which the pollen tubes are emitted even before the opening of the flower: it seems that the great diversity of the lateral anthers observed in one case is favourable to the view that they have only been acquired recently as the result of a chance reversion to a long lost character.¹⁹

With the greatest respect, believe me, dear Sir, that I am sincerely yours | Fritz Müller.

Footnotes

For a transcription of this letter in the German of its published source, see p. 322–4. All Fritz Müller’s letters to CD were written in English (see Möller ed. 1915–21, 2: 72 n.); most of them have not been found. Many of the letters were later sent by Francis Darwin to Möller, who translated them into German for his Fritz Müller: Werke, Briefe und Leben (Möller ed. 1915–21). Möller also found drafts of some Müller letters among Fritz Müller’s papers and included these in their original English form (ibid., 2: 72 n.). Where the original English versions are missing, the published versions, usually appearing in German translation, have been used.