skip to content

Darwin Correspondence Project

From Federico Delpino1   9 October 1869

Firenze

addè 9. 8bre 1869

Celeberrimo uomo!

Ho ricevuto i lavori “On the specific difference between Primula veris etc,” “Offspring from the illegitimate unions of dimorphic and trimorphic plants etc.” notes on the fertilization of orchids.2 Io ne rendo alla S. V. le più sentite grazie. Si sto studiando col massimo impegno, come si deve per ogni cosa che esce dalla penna e dalla mente del più grande naturalista di questo secolo.

Mi permetto alcune rispettose osservazioni. Una infinità di dati mi persuadono che per molti fiori tropicali (e probabilmente per molti delle Orchidee) larghissima e importante parte alla fecondazione debbono prendere gli uccelli mellisugi (Trochilus, Ornismya, Nectariania, Melitreptus e simili).3 O io verso in grave errore, o non mi so spiegare come la S. V. non abbia prego detti pronubi in Speciale considerazione.

Così, contemplando la struttura dei fiori di Corianthes, vedendo la enorme nettaroconea, e la enorme secrezione di liquido dolciastro, dissi tra me: questo fiore deve essere fecondato da un trochilide specialissimo. Ora mi accadde in seguito che sfogliando la opera di Gould sui trochilidi, vidi per lo appunto una tavola ove si scorge un trochilo singolare con becco curiosamente ricurvo visitare i fiori di corianthes, e sorbire il copioso liquido della nettaroconea.4 All’ incontro la spiegazione del Dott. Crüger mi sembra pochissimo fiducievole. La natura non fa glandule melliflue, nè perfettamente lavorate nettaroconche, semplicemente per inumidire le ali di una Euglossa.5 Io mi rimetto ad ulteriore guidizio della S. V.

Mi riuscì oltremodo istruttivo lo apprendere che alcuni insetti vanno sui fiori di orchidee non già per suggere miele ma per rodere speciali escrescenze.6 Questa era una idea che già da un pezzo mi girava per la mente. Piacemi che i fatti corrispondano a questa idea. Tra le orchidee nostrali senza dubbio deve succedere la stessa cosa pel genere Serapias (S. lingua, cordigera, neglecta ecc.)7 Nel fondo del fiore non vi è miele; ma invece vi si trova una grossa escrescenza tinta in purpureo che deve appunto fornir cibo ai pronubi.

Ho ricevuto un numero del giornale ove è comparsa una parte del mio lavoro sulla pangenesi.8 La pangenesi può essere considerata sotto due aspetti; sotto l’aspetto monistico e sotto l’aspetto dualistico.

Sotto l’aspetto monistico mi pare, salvo errore, che non possa concepirsi colle leggi chimiche.

Sotto l’aspetto dualistico, la pangenesi è una mirabile, una grande teoria, che aggruppa felicemente, a mio parere, tutti quanti i fenomeni della genesi degli organismi. Ammettendo la esistenza di gemulle di sostanza immateriale, si sfuggono le objezioni della chimica, si spiega la metagenesi, la generazione alternante, la dislocazione, la moltiplicazione, la diminuzione degli organi, i fenomeni di atavismo ecc. ecc. Io sono compreso di ammirazione per la S.V. che ha saputo formulare una così grande teoria, e sarò lieto se potrò in breve pubblicare una scrittura non indegna dell ’alto argomento, sotto il titolo —Apologia della pangenesi sotto il punto di vista dualistico9

Gradisca il tenuissimo dono di due miei opuscoli con cui ho cercato di utilizzare per la geografia botanica le nozioni sulla dicogamia e di estendere l’albero genealogico delle Marantaceo, nel cui stilo credo di aver ravvisato la parte omologa al rostello (!) delle orchidea.10

Ho l’onore di dichiarararmi della S.V. | Ossequentissimo discepolo

Federico Delpino

Footnotes

For a translation of this letter, see Correspondence vol. 17, Appendix I.
Delpino refers to the genus Trochilus and the now invalid genus Ornismya in the family Trochilidae (hummingbirds), the genus Nectarinia in the family Nectariniidae (sunbirds), and the genus Melithreptus in the family Meliphagidae (honeyeaters).
Delpino refers to John Gould and Gould 1861, 1: plate 3, which depicts Eutoxeres aquila (the white-tipped sicklebill) at a flower of Coryanthes speciosa, a species of bucket orchid.
In ‘Fertilization of orchids’, p. 157, CD had described Hermann Crüger’s observations on the visits of bees of the genus Euglossa to Coryanthes. CD wrote, ‘The fluid in the bucket formed by the basal part of the labellum is not nectar and does not attract insects, but serves, by wetting their wings, to prevent them from crawling out except through the small passages close to the anther and stigma.’ For more on pollination of orchids by Euglossa, see Dressler 1968.
Serapias lingua is the tongue orchid; S. cordigera is the heart-flowered serapias; S. neglecta is the scarce tongue orchid. For more on pollination in this genus, see Jersáková et al. 2006, p. 222.
Delpino refers to the first part of the English translation of his article ‘Sulla darwiniana teoria della pangenesi’ (On the Darwinian theory of pangenesis; Delpino 1869a), published in the 29 September 1869 issue of Scientific Opinion (Delpino 1869b).
The proposed work (Defence of pangenesis from a dualistic point of view) was never published.
The articles referred to are ‘Alcuni appunti di geografia botanica a proposito delle tabelle fitografiche del Prof Hoffmann’ (Some remarks on geographical botany with reference to Prof Hoffmann’s phytographical tables; Delpino 1869c) and ‘Breve cenno sulle relazioni biologiche e genealogiche delle Marantacee’ (Brief remarks on the biology and genealogy of the Marantaceae; Delpino 1869d). CD’s annotated copies of these papers are in the Darwin Pamphlet Collection–CUL.

Bibliography

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

Dressler, Robert L. 1968. Pollination by euglossine bees. Evolution 22: 202–10.

‘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.]

‘Illegitimate offspring of dimorphic and trimorphic plants’: On the character and hybrid-like nature of the offspring from the illegitimate unions of dimorphic and trimorphic plants. By Charles Darwin. [Read 20 February 1868.] Journal of the Linnean Society of London (Botany) 10 (1869): 393–437.

‘Specific difference in Primula’: On the specific difference between Primula veris, Brit. Fl. (var. officinalis of Linn.), P. vulgaris, Brit. Fl. (var. acaulis, Linn.), and P. elatior, Jacq.; and on the hybrid nature of the common oxlip. With supplementary remarks on naturally produced hybrids in the genus Verbascum. By Charles Darwin. [Read 19 March 1868.] Journal of the Linnean Society (Botany) 10 (1869): 437–54.

Translation

From Federico Delpino1   9 October 1869

Florence

9. October 1869

Most illustrious man!

I received the works “On the specific difference between Primula veris etc,” “Offspring from the illegitimate unions of dimorphic and trimorphic plants etc.” notes on the fertilization of orchids.2 I thank you wholeheartedly for them. I am studying them with the utmost care, as one must do with anything coming from the pen and the mind of the greatest naturalist of this century.

I venture a few respectful observations. An infinite number of cases convince me that honeysucking birds (Trochilus, Ornismya, Nectariania, Melitreptus and similar),3 must take a very great and important part in the fecundation of many tropical flowers (and probably of most orchids). Either I am gravely mistaken or I cannot understand how you did not take such pollinators into special consideration.

Thus, while contemplating the structure of the flowers of Corianthes and noticing the enormous nectary cups, and the enormous secretion of sweetish liquid, I said to myself: this flower must be fertilised by a very special trochilus. Now, while skimming through Gould’s work on trochilidae, I happened to see a figure showing a singular trochilus with a curiously bent beak visiting the flowers of corianthes and sucking the abundant liquid from the nectar cup.4 Dr Crüger’s explanation of this seems to me hardly reliable. Nature does not produce honey glands or perfectly designed nectar cups simply to moisten the wings of an Euglossa.5 I would entrust myself to your judgment on this point.

It was extremely informative for me to learn that some insects visit the flowers of orchids not so much to suck honey as to nibble some special outgrowths.6 This idea had been going around in my head for quite some time already. I was pleased that facts correspond to this idea. No doubt the same thing must happen amongst our local orchids, in the genus Serapias (S. lingua, cordigera, neglecta etc.).7 Inside the flower, there is no honey; instead, one finds a large purple outgrowth, the function of which is precisely to provide food for the pollinator.

I have received an issue of the journal in which a part of my work on pangenesis has appeared.8 Pangenesis can be considered from two points of view, that of monism and that of dualism.

From the monistic point of view, it seems to me that, unless I am mistaken, pangenesis is inconceivable within the laws of chemistry.

From a dualistic point of view, pangenesis is a wonderful and great theory that groups together successfully, in my opinion, all phenomena of the genesis of organisms. By admitting the existence of gemmules of non-corporeal substance, we avoid the objections coming from chemistry, we explain metagenesis, the alternation of generations, the dislocation, multiplication, and diminution of organs, the phenomena of atavism etc. etc. I am full of admiration for you for formulating such a great theory, and I will be pleased if I can soon publish a work that is not unworthy of this eminent topic, entitled “Apologia della pangenesi sotto il punto di vista dualistico”.9

Please accept the humble gift of two pamphlets of mine in which I endeavoured to use the notions of dichogamy for botanic geography and to extend the genealogical tree of Marantaceae whose style I recognised as homologous with the rostellum (!) of orchids.10

I have the honour of declaring myself Your Honour’s | Most humble disciple | Federico Delpino

Footnotes

For a transcription of this letter in its original Italian, see pp. 421–3.
Delpino refers to the genus Trochilus and the now invalid genus Ornismya in the family Trochilidae (hummingbirds), the genus Nectarinia in the family Nectariniidae (sunbirds), and the genus Melithreptus in the family Meliphagidae (honeyeaters).
Delpino refers to John Gould and Gould 1861, 1: plate 3, which depicts Eutoxeres aquila (the white-tipped sicklebill) at a flower of Coryanthes speciosa, a species of bucket orchid.
In ‘Fertilization of orchids’, p. 157, CD had described Hermann Crüger’s observations on the visits of bees of the genus Euglossa to Coryanthes. CD wrote, ‘The fluid in the bucket formed by the basal part of the labellum is not nectar and does not attract insects, but serves, by wetting their wings, to prevent them from crawling out except through the small passages close to the anther and stigma.’ For more on pollination of orchids by Euglossa, see Dressler 1968.
Serapias lingua is the tongue orchid; S. cordigera is the heart-flowered serapias; S. neglecta is the scarce tongue orchid. For more on pollination in this genus, see Jersáková et al. 2006, p. 222.
Delpino refers to the first part of the English translation of his article ‘Sulla darwiniana teoria della pangenesi’ (On the Darwinian theory of pangenesis; Delpino 1869a), published in the 29 September 1869 issue of Scientific Opinion (Delpino 1869b).
The proposed work (Defence of pangenesis from a dualistic point of view) was never published.
The articles referred to are ‘Alcuni appunti di geografia botanica a proposito delle tabelle fitografiche del Prof Hoffmann’ (Some remarks on geographical botany with reference to Prof Hoffmann’s phytographical tables; Delpino 1869c) and ‘Breve cenno sulle relazioni biologiche e genealogiche delle Marantacee’ (Brief remarks on the biology and genealogy of the Marantaceae; Delpino 1869d). CD’s annotated copies of these papers are in the Darwin Pamphlet Collection–CUL.

Bibliography

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

Dressler, Robert L. 1968. Pollination by euglossine bees. Evolution 22: 202–10.

‘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.]

‘Illegitimate offspring of dimorphic and trimorphic plants’: On the character and hybrid-like nature of the offspring from the illegitimate unions of dimorphic and trimorphic plants. By Charles Darwin. [Read 20 February 1868.] Journal of the Linnean Society of London (Botany) 10 (1869): 393–437.

‘Specific difference in Primula’: On the specific difference between Primula veris, Brit. Fl. (var. officinalis of Linn.), P. vulgaris, Brit. Fl. (var. acaulis, Linn.), and P. elatior, Jacq.; and on the hybrid nature of the common oxlip. With supplementary remarks on naturally produced hybrids in the genus Verbascum. By Charles Darwin. [Read 19 March 1868.] Journal of the Linnean Society (Botany) 10 (1869): 437–54.

Summary

Acknowledges receipt of CD’s Primula paper [J. Linn. Soc. Lond. (Bot.) 10 (1869): 437–54].

Nectar-sucking birds fertilise tropical flowers.

Writing a "Dualistic apologia for Pangenesis" [see translation in Sci. Opin. 2 (1869): 365–7, 391–3, 407–8].

Homology of the orchid rostellum.

Letter details

Letter no.
DCP-LETT-6928
From
Federico Delpino
To
Charles Robert Darwin
Sent from
Florence
Source of text
DAR 162: 144
Physical description
4pp (Italian)

Please cite as

Darwin Correspondence Project, “Letter no. 6928,” accessed on 20 October 2019, https://www.darwinproject.ac.uk/letter/DCP-LETT-6928.xml

Also published in The Correspondence of Charles Darwin, vol. 17

letter