iS4 THE ENTOMOLOGIST. 



taneously ; their gradual issue had probably been delayed by the 

 colder rainy weather. It would seem that the direction of the wind 

 influences to a certain extent the direction of flight of butterflies. 

 When crossing from Rio Janeiro by steamer to the island of Paqueta, 

 in the bay of Rio, I saw butterflies pass frequently across the bay with 

 the wind, but I saw none pass against the wind. They were going 

 from the direction of Nitheroy towards Maua, on the other side of the 

 bay. When I returned, about a week afterwards, from Paqueta to 

 Rio, I observed the same flight across the bay, and from more or less 

 the same direction. They did not go past in a swarm, but singly or 

 two or three together, and at sufliciently frequent intervals as to 

 attract attention. — Wm. C. Tait ; Oporto, January, 1894. 



Macroglossa stellatarum and Colour. — Referring to Mr. Shaw's 

 article {ante, p. 20), and Mr. Bedford's and Mr. Johnson's observa- 

 tions thereon [ante, p. 62), in the translation of Professor Hermann 

 Miiller's work, ' The Fertilization of Flowers ' (Macmillan & Co., 

 1883), p. 119, it is stated that " Viola calcarata, L., greatly surpasses 

 Viola tricolor in the size of its flower and the length of its spur (13 to 

 25 mm.). It is fertilised only by Lepidoptera, chiefly by Macroglossa 

 stellatarum (25 to 28 mm.), our quickest worker. I have seen this 

 insect visit 194 flowers on difl'erent plants in Of minutes, and I could 

 see it cross-fertilise them by means of its proboscis, dusted with white 

 pollen." The different species of Viola are discussed with reference to 

 the insects fertilising them, including nocturnal and other Lepidoptera, 

 amongst the species mentioned as visitors being Vanessa urtica, Liliodocera 

 rhamni [Viola odoratn), Pier is rapce and P. napi, and Rhodocera rhamni 

 {Viola sylvatica, Fries), and Pieris rapm and P. napi {Viola canina). 

 The evolution of colour in violets, from an original yellow, is also 

 alluded to, and the colours of flowers with reference to their fertili- 

 sation by diurnal or nocturnal species touched upon ; and in this con- 

 nection may it not be that the cause of the purple, lilac, and black 

 shades of Viola being neglected by Macroglossa stellataru)ii^{n,s men- 

 tioned by Mr. Shaw) is that they are the more advanced forms ? With 

 reference to Caltha segetum mentioned by Mr. Shaw {ante, p. 21), 

 although this plant does not appear to be referred to in the above 

 work, a list of insects visiting Caltha paliistris (including Diptera, 

 Coleoptera and Hymenoptera) is given, pp. 79 and 80, but no Lepi- 

 doptera are included in the list ; is it not, therefore, probable that 

 neither species of Caltha is suitable for fertilisation by Lepidoptera ? 

 and is not the true reason why any particular flower is shunned by 

 certain insects and visited systematically by others, that the visiting 

 insects alone are able, having regard to the mutual formation of flower 

 and visitor, to fertilise the particular species of flower, rather than 

 that the insect has acquired a taste for the particular nectar yielded, 

 as suggested by Mr. Bedford? The whole basis of the above work 

 appears to proceed on the first view. With regard to species of 

 Geranium, on p. 157 it is stated that Pieris napi visits Geranium 

 robertianum, and that twenty-one species of Lepidoptera have been 

 found upon the flowers of G. sylvaticum, which is visited by seventy-four 

 species of various orders. The flowers visited by Macroglossa stella- 

 tarum are stated to be (as observed), Dianthus carthusianorum, L., JEno- 



