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Darwin Correspondence Project

From Robert Caspary   25 February 1866

Koenigsberg in Pr.

25th. Febr. 1866

My dear Sir

Many thanks for your letter.1 I stand indeed to you under very great obligations for your kindly sending me all your publications and I should have long ago written to you to thank you, had I not been afraid of giving you more trouble by my letters, than my thanks would be worth.2 That your papers were most useful to me and others here, you will see from the account, which I gave of some in connexion with some other publications, which your observations and hypotheses elicited.3 The account, which I add, is accompanied with a few lines on those peculiar appearances, of which I am now convinced that they are caused by a sort of hybridism in consequence of grafting. The account is published in: Schriften der physikalisch-œkonomischen Gesellschaft zu Koenigsberg Jahrgang VI Sitzungsberichts, p. 4.4

The account of what I said on the same subject at the Amsterdam-congress—is printed about 4 or 5 months ago but has not yet been published.5 At the time I corrected the letterpress, which Professor Rauwenhoff6 at Rotterdam sent me, being the editor of the transactions of that congress. I write at once to Professor Rauwenhoff to tell him, that he might send you directly a copy; I have none. The transactions of that Congress will be published in 8o.7

I collected material or rather was allways at the look-out for material for more than 10 years on the hybridization and muling by grafting. The case of Cytisus Adami I had an opportunity of examining in a most perfect development at Bonn—8 As regards the Bizarrin9 I saw no case, nor any person living, who ever had observed one, except Professor Passerini at Parma,10 who is about of procuring me one or two trees, which exhibit Bizarrin, but I am afraid our climate will be too severe for it, as it is for Cytisus Adami.

If I had 3 or 4 weeks to spare I should prepare a full paper on the matter, not being able at present to add any thing. But I shall not have time to do so before 2— or 3 months have elapsed, as I am very hard at work to finish some papers on Nymphaeaceae, which I promised to Professor Miquel and V. Martius.11 Having finished those papers I took the resolution of writing down at full length my observations on Cytisus Adami and similar subjects. The account on them which I gave at the Amsterdam Congress is a very brief one.12

At the close of the paper, I add, I mentioned the seeds of Euryale, ripened by flowers, which remained under water and did not open.13 Now I got last year many of that description and some allready germinated.

I take the liberty of adding my photography and asking for yours—14 You could do me no greater favor, than if you would send it me.

Yours most respectfully and faithfully | R. Caspary


Caspary’s name is on CD’s presentation list for Origin (see Correspondence vol. 8, Appendix III). No record that CD sent Caspary any of his other publications has been found.
Caspary 1865b discussed recent botanical work relevant to CD’s hypothesis, presented in Origin, pp. 96–101, that occasional or habitual intercrossing occurred between hermaphrodite individuals. Caspary reviewed CD’s arguments in Orchids, ‘Dimorphic condition in Primula, ‘Two forms in species of Linum, and ‘Three forms of Lythrum salicaria, and described various cleistogamic (small, unopening) flowers that presented a challenge to CD’s hypothesis. CD’s annotated copy of Caspary 1865b is in the Darwin Pamphlet Collection–CUL. For CD’s interest in cleistogamic flowers, see Correspondence vols. 10–12.
Caspary refers to Caspary 1865c, a short paper in which he claimed to have observed ‘an unquestionable instance of the origination of a hybrid by grafting’: a white moss-rose that had been grafted onto a stock of Rosa centifolia developed shoots and flowers of both forms, as well as flowers and stalks that were compounded of both forms. Caspary suggested that the peculiar features of this hybrid were analogous to those of Cytisus adami (now +Laburnocytisus adamii), and the ‘bizzarria orange’, and thus lent support to the view that these were also graft hybrids. CD’s annotated copy of Caspary 1865c is in the Darwin Pamphlet Collection–CUL, bound with a handwritten English translation of part of the paper. On Cytisus adami and CD’s interest in graft hybrids, see the letter to Robert Caspary, 21 February [1866] and n. 3; see also n. 9, below.
Caspary refers to Caspary 1865a. See letter to Robert Caspary, 21 February [1866] and n. 2.
8o: i.e., octavo.
Caspary was director of the herbarium at the University of Bonn from 1856 to 1858 (ADB).
In Caspary 1865a, pp. 66–9, the bizzarria orange is described as the earliest recorded case of a graft hybrid: produced in Italy in 1644, by grafting a scion of the bitter orange (Citrus bigaradia, now C. aurantium) onto a stock of the citron (C. medica), the plant developed leaves, flowers, and fruit of both parent forms, as well as compound fruit. In Variation 1: 391, CD described the bizzarria orange as a ‘strictly parallel case to that of Cytisus adami’. See also n. 4, above.
Caspary contributed articles on the family Nymphaeaceae to the Annales Musei Botanici Lugduno-Batavi, edited by Friedrich Anton Wilhelm Miquel (Caspary 1866b), and to Karl Friedrich Philipp von Martius’s Flora Brasiliensis (Caspary [1878]).
Caspary refers to Caspary 1865a.
In Caspary 1865b, p. 20, the self-fertility of the waterlily, Euryale ferox, and the apparent ability of its unopened flowers to set seed under water, are described. CD’s copy of Caspary 1865b is bound with a page of notes on E. ferox and other species with cleistogamic flowers; the notes were used in Cross and self fertilisation, p. 365.
Caspary’s photograph has not been found in the Darwin Archive–CUL.


ADB: Allgemeine deutsche Biographie. Under the auspices of the Historical Commission of the Royal Academy of Sciences. 56 vols. Leipzig: Duncker & Humblot. 1875–1912.

Caspary, Johann Xaver Robert. [1878.] Nymphaeaceae. In vol. 4 of Flora Brasiliensis, edited by Karl Friedrich Philipp von Martius. Leipzig: apud Frid. Fleischer in Comm.

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

Cross and self fertilisation: The effects of cross and self fertilisation in the vegetable kingdom. By Charles Darwin. London: John Murray. 1876.

‘Dimorphic condition in Primula’: On the two forms, or dimorphic condition, in the species of Primula, and on their remarkable sexual relations. By Charles Darwin. [Read 21 November 1861.] Journal of the Proceedings of the Linnean Society (Botany) 6 (1862): 77–96. [Collected papers 2: 45–63.]

Orchids: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. By Charles Darwin. London: John Murray. 1862.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

‘Three forms of Lythrum salicaria’: On the sexual relations of the three forms of Lythrum salicaria. By Charles Darwin. [Read 16 June 1864.] Journal of the Linnean Society (Botany) 8 (1865): 169–96. [Collected papers 2: 106–31.]

‘Two forms in species of Linum’: On the existence of two forms, and on their reciprocal sexual relation, in several species of the genus Linum. By Charles Darwin. [Read 5 February 1863.] Journal of the Proceedings of the Linnean Society (Botany) 7 (1864): 69–83. [Collected papers 2: 93–105.]

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Sends papers on graft-hybrids ["Sur les hybrides obtenus par la greffe", Bull. Congr. Int. Bot. & Hortic. Amsterdam (1865): 65–80, and "Über Mischlinge, durch Pfropfen entstanden", Sitzungsber. K. Phys.-oekon. Ges. Königsberg 6 (1865): 11–21].

Letter details

Letter no.
Johann Xaver Robert (Robert) Caspary
Charles Robert Darwin
Sent from
Source of text
DAR 161: 118
Physical description
ALS 4pp †

Please cite as

Darwin Correspondence Project, “Letter no. 5018,” accessed on 30 May 2023,

Also published in The Correspondence of Charles Darwin, vol. 14