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INTRODUCTION 



beetles that penetrated into the flowers, or long-tongued flies (Bombylius, Rhingia, 

 Empis) or humble-bees which managed to reach the nectar, or thievish humble-bees 

 that broke in and carried away the spoil. It is only in a few Lepidopterid Flowers, 

 continues Miiller, that the booty is materially diminished by these intruders. This 

 is the case, however, in Gentiana verna, Silene nutans and inflata, where it is due 

 to the incursions of humble-bees, and it is particularly so in Rhinanthus alpinus, 

 which is rendered useless to humble-bees by the Lepidoptera. 



Hermann Muller (Kosmos, iii, 1878, pp. 417 and 418) called attention to 

 a most remarkable relation between the coloration of Butterfly Flowers and that of 



Fig. 36. A. Lychnis Flos-cuculi^ in which the nectar is secured by long-tongued bees and hover-flies, 

 as well as by Lepidoptera. B. Lychnis Flos-Jovis, in which the honey is secured only by Lepidoptera. 

 CD. Z?a;*/jH£ Af^^^r^wwj, visited by Lepidoptera, Bees, and Flies. E. F. Daphne striata,v\i\te^Aoti\y by 

 Lepidoptera. (After Herm. Miiller.) 



their lepidopterous guests. 'It is certainly not purely accidental,' says Muller, 'that 

 most of the butterflies of the Alps, the commonest floral guests in that region, are 

 vivid red in colour (numerous species of Argynnis and Melitaea, and several of 

 Polyommatus and Vanessa), and that bright red flowers are visited with marked 

 preference by such butterflies.' Miiller noticed, for example, that the flowers of 

 Lilium bulbiferum were exclusively visited by the fiery-red species Argynnis Aglaja, 

 Polyommatus Virgaureae, and P. hippothoe var. eurybia, these insects being such 

 frequent visitors that several of them often settled at once on the same flower, to 

 which their similarity in colour at the same time aff'orded them the protection of 

 invisibility. I may add, as a further example, that the Brimstone Butterfly (Rhodo- 

 cera Rhamni), which is the commonest visitor and pollinator of Primula acaulis, has 

 precisely the same colour as the flower it visits. 



