From Fritz Müller   [27 November 1877]1

Santa Caterina, Brazil

My children lately caught on flowers of Calonyction (sp. ?) a Sphinx-moth, the proboscis of which is 22 centimetres long. As I think that you would be glad to see this curious proboscis I send it to you.2 […] During the month of October I have watched for some weeks the butterflies visiting a Lantana near my house, the flowers of which are yellow the first day, orange the second, purple the third day, and falling off on the morning of the fourth.3 Eight out of eleven species of butterflies (Heliconius apseudes, Colænis Dido, C. Julia, Dione Juno, Hesperocharis Anguitia, Eurema Leuce, Daptonoura Lycimnia, and Callidryas Cipris) never touched an orange or purple flower, limiting their visits exclusively to the yellow ones.4 Two specimens of Pieris Aripa (or Elodia?) proceeded in the same way, whilst a third specimen of this Pieris inserted its proboscis indifferently into yellow or orange flowers.5 Three specimens of Danais Erippus evidently preferred yellow flowers, but sometimes also tried orange flowers, and one of them even once put its proboscis into a purple flower; a fourth specimen of Danais visited yellow flowers only.6 Lastly, I saw three specimens of Hesperidæ, but as I did not catch them, and as the species most closely resemble each other, I do not know whether they belonged to the same species; two visited exclusively yellow flowers, the third indifferently flowers of any colour—yellow, orange, or purple.7 These observations, of which a full account will be published in the ‘Archivos do Museo Nacional do Rio de Janeiro,’ confirm those by Delpino on Ribes aureum and Caragana arborescens.8 If the flowers lasted but one day the flower-heads would be by far less conspicuous; if they lasted three days without changing colour, butterflies would lose much time in visiting honeyless, already-fertilized flowers. […] Yesterday I caught, for the first time, the male of a Sphinx-moth which exhaled a strong musk-like odour; as you know, this is also the case with the males of the European S. convolvuli and S. ligustri; but nobody has as yet, so far as I know, indicated the odiferous organ. It is formed by two pencils of hairs situated on the ventral side of the base of the abdomen, and when at rest are perfectly hidden by the scales (hairs?).9

diagram

I do not remember whether I have already called your attention to an interesting secondary sexual character observable in several species of Callidryas and some other Pierinæ. The costal margin of the anterior wing is sharply serrated in the males, while it is smooth in the females. In Callidryas Philea some females have the wings smooth, others serrated, but in a far less degree than in the male. This may be a sort of weapon in the battles of the males.10 Whether in Papilio Grayi, P. Cleotas, P. Coræbus, and their allies, the serrated margin of the fore wings is limited to the male sex I do not know, not having yet caught females of these rare species.11

1
The date is given in the published source.
2
Calonyction is a synonym of Ipomoea; Müller probably observed I. alba (tropical white morning-glory). The moth species was later identified as Macrosilia cluentius (a synonym of Neococytius cluentius, the cluentius sphinx; see Nature, 17 January 1878, p. 221). CD sent the letter and enclosures to Raphael Meldola, who exhibited the proboscis at a meeting of the Entomological Society of London on 6 February 1878 (see Transactions of the Entomological Society of London (1878): (Proceedings) iii).
3
The species was probably Lantana camara (see letter from Fritz Müller, 19 October 1877 and n. 8).
4
Heliconius apseudes is a synonym of H. sara subsp. apseudes (Sara longwing); Colaenis dido is a synonym of Philaethria dido (scarce bamboo page or Dido longwing); Colaenis julia is a synonym of Dryas iulia (Julia longwing); Dione juno is the Juno silverspot or Juno longwing; Hesperocharis anguitia is the Neemia butterfly; Eurema leuce is Hall’s sulphur butterfly; Daptonoura lycimnia is a synonym of Melete lycimnia; Callidryas cipris is a synonym of Phoebis neocypris (tailed sulphur).
5
Pieris aripa is a syonym of Leptophobia aripa (mountain white). A recognised subspecies is Leptophobia aripa elodia, but it does not occur in Brazil; the Brazilian subspecies is Leptophobia aripa balidia.
6
Danais erippus is a synonym of Danaus erippus (southern monarch)
7
Hesperidae (a synonym of Hesperiidae) is the family of skipper butterflies; they are small brown or orange butterflies characterised by rapid, skipping flight.
8
See ‘A correlação das flores versicolores e dos insectos pronubos’ (The correlation of varicoloured flowers and their insect pollinators; Fritz Müller 1877c). Federico Delpino had made similar observations in Delpino 1873, pp. 176–7 (see letter from Fritz Müller, 19 October 1877 and n. 7). Ribes aureum is the golden currant; Caragana arborescens is the Siberian pea tree.
9
Sphinx convolvuli is a synonym of Agrius convolvuli (convolvulus hawk-moth); S. ligustri is the privet hawk-moth. In Fritz Müller 1878, p. 220, Müller discussed the hair-pencils in Macrosilia antaeus (a synonym of Cocytius antaeus, the giant sphinx), noting that the pencils were hidden in abdominal grooves when the moth’s wings were at rest.
10
Callidryas philea is a synonym of Phoebis philea (orange-barred sulphur butterfly); the Pierinae (whites) are a subfamily of the family Pieridae (orange-tips, whites, sulphurs). Müller had discussed the role of this species in the fertilisation of flowers of Hedychium (see Correspondence vol. 24, letter to Hermann Müller, 7 August 1876 and n. 1). Müller sent a specimen of the wings, which was exhibited by Meldola at a meeting of the Entomological Society of London on 6 February 1878 (see Transactions of the Entomological Society of London (1878): (Proceedings) iii).
11
Papilio grayi is a synonym of P. scamander (scamander swallowtail); P. cleotas is a synonym of P. menatius cleotas; P. coroebus is a synonym of P. menatius coroebus.
12
The original letter has not been found. CD communicated it to the Entomological Society of London, and it was read by Meldola at a meeting on 6 February 1878.

Please cite as “DCP-LETT-11255F,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11255F