Scent-fans of a Sphinx-moth 1 ). 



Mil I Textfigur. 



Mr. Meldola read the following extracts from a letter from Dr. Fritz Miiller 

 to Mr. Charles Darwin, dated from Santa Catharina, Brazil, 27th November 1877. 



"My children lately caught on the 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. * 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. Eight out 

 of eleven species of butterflies (Heliconius apseudes, Colffmis Dido, C. Julia, 

 Dione Juno, HesperocJiaris Anguitia, Eurema Leuce, Daptonoura Lycimnia, 

 and Callidryas Cipris] never touched an orange or purple flow^er, 

 limiting their visits exclusively to the yellow ones. 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. 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. Lastly, I saw three specimens of Hesperida-, 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 in- 

 differently flowers of any colour yellow, orange, or purple- 

 These observations, of which a full account will be published in the 

 'Archives do Museo Nacional do Rio de Janeiro,' 2 ) confirm those by 

 Delpino on Ribes aureum and Caragana arborescens. If the flowers lasted but 

 one day the flowerheads would be by far less conspicuous; if they lasted three 

 days without changing colour, butterflies would lose much time in visiting honey- 

 less, already-fertilized flowers. * Yesterday I caught, for the first i.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 5". convolvuli and S. ligustri; 

 but nobody has as yet, so far as I know, indicated the odoriferous 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?). 



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 Pierime. The costal margin of the anterior wing is sharply 



1) Proceedings of the Entomological Society of London. 1878. p. II III. 



2) Siehe Ges. Schriften S. 547 ff. auch S. 577. 



