skip to content

Darwin Correspondence Project

From Federico Delpino1   7 January 1871

Vallombrosa | Firenze

7. Genn. 1871

Onorevole Signore!

Prego la S.V. a voler aggradire l’omaggio di due esemplari d’un mio lavoro (Ulteriori osservaz. ecc. pte II. f. 1), e nello stesso tempo la ringrazio della cortese lettera del 23. Xbre scorso, e degli utilissimi cenni che sono contenuti nella medesima.2

Per colpa della pessima mia memoria, mi erano sfuggite le interessanti notizie che dà a pag. 2 e 3 (notes on the fertilization of Orchids) concernenti l’Orchis morio, O. maculata ecc. e i loro pronubi.3 Ora le ho riandate, e mi trovo costretto a modificare fortemente la mia opinione. È vero che io non ho mai trovato liquido entro la svescicatura dello sperone; ma quel che non mi è occorso di poter notare nella Liguria e nella Toscana, potrebbe benissimo accadere in altre regioni. Tanto più che vedo come le Orchis succitate siano visitate frequentemente in Inghilterra da molti insetti, Empis, Bombus, Apis, Eucera …,4 mentre io, in Liguria, non ho potuto giammai sorprendervi insetti; rarissime sono ivi le masse polliniche asportate via, e rarissimi gli ovarii abboniti.

Una osservazione che ho fatto pochi mesi sono mi fa credere realmente alla possibilita di una secrezione nettarea od analoga, subepidermica. Questo fenomeno è frequentissimo nelle Malpighiacee. Sospetto anche che abbia luogo presso alcune Primulae, la cui corolla all’interno trovai svescicata in maniera affatto analoga agli speroni delle orchidi nostrane. Alla prima occasione rettificherò la mia troppo avanzata proposizione.5

Io avrei da molto tempo pubblicato un breve cenno sulla fecondazione incrociata dei cereali. Le osservazioni che feci non mancavano d’interesse, ma io ebbi la sbadataggine di non iscriverle subito, cosicchè ora non oso di scrivere alcuna cosa in proposito per tema di non ricordarmi più bene dei dettagli.

Posso per altro guarentire positivamente

lo che nel grano (Triticum) ogni fiore può fecondarsi da se stesso, perchè una parte del polline è versata dentro il fiore e l’altra parte è versata fuori all’atto preciso della deiscenza del fiore; deiscenza che dura circa un quarto d’ora.

2o che nel Triticum la dicogamia ossia la fecondazione incrociata non è esclusa, giacchè il fiore si rende deiscente, sebbene per poco tempo, e giacchè metà del polline è versato fuori nell’aria, in balìa del vento;

3o che alcune piante di Triticum allontanate l’una dall’altra, in modo da escludere il polline eteroclino,6 abbonirono tuttavia tutti i semi. Cosicchè per il triticum è possibile la omogamia non meno che la dicogamia—;

4o che nella Secale7 la dicogamia è quasi necessaria, perchè la deiscenza del fiore è totale e perchè la esserzione degli stimmi e delle antere è completa;

5o che nell Hordeum vulgare8

[DIAG HERE]

le due serie dei fiori mediane nella spiga (b, b) non si aprono mai e quindi è impossibile per essi la dicogamia, e le quattro serie angolari dei fiori (a, a, a, a) si aprono un poco, e quindi per essi può succedere la omogamia e la dicogamia—

6o. che infine l’Hordeum distichum9 offre un fenomeno interessantissimo.

Esso ha due specie di fiori gli uni destinati per la omogamia. Essi non si aprono mai, e la fecondazione è già avvenuta prima ancora che la spiga esca fuori completamente dalla sua vagina fogliare.

Gli altri fiori sono pochissimi, e sono destinati esclusivamente per la dicogamia. In grandezza superano assai i precedenti. Così nell’Hordeum ossia in una pianta d’indole anemofila si ripete quell’interessante fenomeno finora constato nelle sole piante entomofile dei generi Viola, Impatiens, Vicia amphicarpa, Lathyrus amphicarpus,10 producenti due sorta di fiori, gli uni destinati per la omogamia e sprovvisti di corolla, di colori e di miele, gli altri destinati per la dicogamia, cioè colorati, corolliferi e nettariferi.

Mi riconfermo colla più alta stima e rispetto della S.V. onorevolissima | ossequentissimo discepolo | Federico Delpino

CD annotations

1.1 Prego … abboniti 2.10] ‘Dichogamy—Cleistogene—Dimorphism’ pencil
Top of letter: ‘Cleistogene flowers in Hordeum | [anemophilous] plant—new & good case’ pencil

Footnotes

For a translation of this letter, see Correspondence vol. 19, Appendix I.
Delpino refers to the first fascicle of the second part of Ulteriori osservazioni sulla dicogamia nel regno vegetale (Further observations on dichogamy in the vegetable kingdom; Delpino 1868–75). CD had received part I in 1869 (see Correspondence vol. 17, letter from Federico Delpino, 22 August 1869). The work as a whole consists of two parts, and each part comprises several fascicles published at intervals. There is an annotated copy of Delpino 1868–75 in the Darwin Library–CUL. CD’s letter to Delpino of 23 December 1870 has not been found.
Delpino refers to ‘Fertilization of orchids’, pp. 142–3. Orchis maculata is now Dactylorhiza maculata.
Empis is a fly genus; Bombus, Apis, and Eucera are bee genera. CD discussed their visits to orchids in ‘Fertilization of orchids’, pp. 142–3.
On CD and Delpino’s disagreement over whether nectarless flowers offered some other reward to visiting insects, see Pancaldi 1991, pp. 123–9. Delpino retracted his ‘correction’ after further observations.
Heterocline: having male and female flower-heads or separate receptacles (OED).
Secale: rye.
Hordeum vulgare: common barley.
Hordeum distichum is an alternative spelling of H. distichon, now considered to be a variety of H. vulgare vulgare. It was known as two-rowed barley. On H. vulgare and H. distichum, see also Correspondence vol. 17, letter from Federico Delpino, 1 November 1869. In Forms of flowers, pp. 332–3, CD cited Delpino for having shown that some flowers of Hordeum allowed cross-fertilisation.
The species Vicia amphicarpa and Lathyrus amphicarpus are both now Vicia sativa ssp. amphicarpa, subterranean vetch.

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 26 vols to date. Cambridge: Cambridge University Press. 1985–.

Delpino, Federico. 1868–75. Ulteriori osservazioni sulla dicogamia nel regno vegetale. 2 parts. Milan: Giuseppe Bernardoni. [Originally published in Atti della Societa Italiana di Scienze Naturali Milano 11 (1868): 265–352; 12 (1869): 179–233; 13 (1870): 167–205; 17 (1874): 266–407.]

‘Fertilization of orchids’: Notes on the fertilization of orchids. By Charles Darwin. Annals and Magazine of Natural History 4th ser. 4 (1869): 141–59. [Collected papers 2: 138–56.]

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

OED: The Oxford English dictionary. Being a corrected re-issue with an introduction, supplement and bibliography of a new English dictionary. Edited by James A. H. Murray, et al. 12 vols. and supplement. Oxford: Clarendon Press. 1970. A supplement to the Oxford English dictionary. 4 vols. Edited by R. W. Burchfield. Oxford: Clarendon Press. 1972–86. The Oxford English dictionary. 2d edition. 20 vols. Prepared by J. A. Simpson and E. S. C. Weiner. Oxford: Clarendon Press. 1989. Oxford English dictionary additional series. 3 vols. Edited by John Simpson et al. Oxford: Clarendon Press. 1993–7.

Pancaldi, Giuliano. 1991. Darwin in Italy. Science across cultural frontiers. Translated by Ruey Brodine Morelli. Updated and expanded edition. Bloomington and Indianapolis, Ind.: Indiana University Press.

Translation

From Federico Delpino1   7 January 1871

Vallombrosa | Florence

7. Jan. 1871

Honourable Sir!

I beg Your Honour to accept the gift of two copies of a work of mine (Ulteriori osservaz. etc. pt II. fasc. 1), and I would also like to thank you for your kind letter of 23. December of the previous year, and for the most useful accounts enclosed in it.2

Due to my terrible memory, I had forgotten about your interesting notes on pp. 2 and 3 (notes on the fertilization of Orchids), regarding Orchis morio, O. maculata etc. and the insects that fertilise them.3 Now I have gone back to them and I find I must strongly modify my views. It is true that I have never found liquid in blistered spurs; but what I have not had the fortune to observe in Liguria and Tuscany could very well happen in other regions. All the more so since I see that the said orchids are frequently visited, in England, by a number of insects, Empis, Bombus, Apis, Eucera …,4 while I myself was never able to catch insects in the act in Liguria; there the pollen-masses that are carried away are most scanty, and mature ovaries are most rare.

An observation I made a few months ago leads me to entertain seriously the possibility of a nectareous or analogous secretion, underneath the lining. This phenomenon is most common in Malpighiaceae. I also suspect that it occurs in some Primulae, whose corolla I have found blistered on the inside in a way wholly analogous to the spurs in our orchids. As soon as I get the chance I shall correct my too rash proposition.5

Quite some time ago I should have published a brief account of the cross-fertilization of cereals. The observations I made were not without interest, but I was careless and did not write them up immediately, so that now I don’t dare write anything on the topic for fear of not remembering the details well enough.

I can however positively confirm

1. that in wheat (Triticum) every flower can fertilise itself, since part of the pollen is turned towards the flower and the other part is turned outwards at the precise moment when the flower bursts open; this dehiscence lasts about a quarter of an hour.

2. that in Triticum dichogamy or cross-fertilization is not excluded, for the flower opens up, if for a short time only, and half the pollen is turned outwards to the air, at the mercy of the wind;

3. that plants of Triticum that are separated from one another, so as to exclude heterocline6 pollen, still develop all the seeds. For triticum, homogamy is therefore no less an option than dichogamy—;

4. that in Secale7 dichogamy is practically a necessity, since the dehiscence of the flower is total and since the exsertion of the stigma and of the anthers is complete;

5. that in Hordeum vulgare8

[DIAG HERE]

the two centre sets of flowers in the ears of corn (b, b) don’t ever open and therefore it is impossible that they could be dichogamic, and the four corner sets of flowers (a, a, a, a) open a little, and hence they may be homogamic or dichogamic.

6. finally that Hordeum distichum9 constitutes a most interesting phenomenon.

This plant has two kinds of flowers, one of them meant for homogamy. They never open, and fertilisation is hence completed even before the ear of corn has completely emerged from its leafy sheath.

Of the other flowers, there are very few, and they are exclusively dichogamic. In size they by far exceed the former. Thus, in Hordeum and in anemophilous plants, an interesting phenomenon can be observed that has hitherto been displayed only by entomophilous plants of the species Viola, Impatiens, Vicia amphicarpa, Lathyrus amphicarpus.10 They produce two kinds of flowers, one destined for homogamy and not equipped with a corolla, colours and honey, the other meant for dichogamy, hence coloured and carrying a corolla and nectar.

Once again I remain with the highest esteem and respect for Your most revered Honour | your most devoted disciple | Federico Delpino

Footnotes

For a transcription of this letter in its original Italian, see pp. QQQQ.
Delpino refers to the first fascicle of the second part of Ulteriori osservazioni sulla dicogamia nel regno vegetale (Further observations on dichogamy in the vegetable kingdom; Delpino 1868–75). CD had received part I in 1869 (see Correspondence vol. 17, letter from Federico Delpino, 22 August 1869). The work as a whole consists of two parts, and each part comprises several fascicles published at intervals. There is an annotated copy of Delpino 1868–75 in the Darwin Library–CUL. CD’s letter to Delpino of 23 December 1870 has not been found.
Delpino refers to ‘Fertilization of orchids’, pp. 142–3. Orchis maculata is now Dactylorhiza maculata.
Empis is a fly genus; Bombus, Apis, and Eucera are bee genera. CD discussed their visits to orchids in ‘Fertilization of orchids’, pp. 142–3.
On CD and Delpino’s disagreement over whether nectarless flowers offered some other reward to visiting insects, see Pancaldi 1991, pp. 123–9. Delpino retracted his ‘correction’ after further observations.
Heterocline: having male and female flower-heads or separate receptacles (OED).
Secale: rye.
Hordeum vulgare: common barley.
Hordeum distichum is an alternative spelling of H. distichon, now considered to be a variety of H. vulgare vulgare. It was known as two-rowed barley. On H. vulgare and H. distichum, see also Correspondence vol. 17, letter from Federico Delpino, 1 November 1869. In Forms of flowers, pp. 332–3, CD cited Delpino for having shown that some flowers of Hordeum allowed cross-fertilisation.
The species Vicia amphicarpa and Lathyrus amphicarpus are both now Vicia sativa ssp. amphicarpa, subterranean vetch.

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 26 vols to date. Cambridge: Cambridge University Press. 1985–.

Delpino, Federico. 1868–75. Ulteriori osservazioni sulla dicogamia nel regno vegetale. 2 parts. Milan: Giuseppe Bernardoni. [Originally published in Atti della Societa Italiana di Scienze Naturali Milano 11 (1868): 265–352; 12 (1869): 179–233; 13 (1870): 167–205; 17 (1874): 266–407.]

‘Fertilization of orchids’: Notes on the fertilization of orchids. By Charles Darwin. Annals and Magazine of Natural History 4th ser. 4 (1869): 141–59. [Collected papers 2: 138–56.]

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

OED: The Oxford English dictionary. Being a corrected re-issue with an introduction, supplement and bibliography of a new English dictionary. Edited by James A. H. Murray, et al. 12 vols. and supplement. Oxford: Clarendon Press. 1970. A supplement to the Oxford English dictionary. 4 vols. Edited by R. W. Burchfield. Oxford: Clarendon Press. 1972–86. The Oxford English dictionary. 2d edition. 20 vols. Prepared by J. A. Simpson and E. S. C. Weiner. Oxford: Clarendon Press. 1989. Oxford English dictionary additional series. 3 vols. Edited by John Simpson et al. Oxford: Clarendon Press. 1993–7.

Pancaldi, Giuliano. 1991. Darwin in Italy. Science across cultural frontiers. Translated by Ruey Brodine Morelli. Updated and expanded edition. Bloomington and Indianapolis, Ind.: Indiana University Press.

Summary

Sends his new work, Ulteriori osservazioni sulla dicogomia pt 2, fasc. 1.

Has found no nectar in Orchis morio or O. maculata in Italy and has seen no insects visiting the plants.

Gives his observations on cross- and self-fertilisation in cereals.

Letter details

Letter no.
DCP-LETT-7430
From
Federico Delpino
To
Charles Robert Darwin
Sent from
Florence
Source of text
DAR 111: A77–8
Physical description
4pp (Italian) †

Please cite as

Darwin Correspondence Project, “Letter no. 7430,” accessed on 17 October 2019, https://www.darwinproject.ac.uk/letter/DCP-LETT-7430.xml

Also published in The Correspondence of Charles Darwin, vol. 19

letter