THE SWALLOWS AGAIN. 53 



in many respects, still bear evident traces of their origi- 

 nal derivation. The sun-birds are by origin creepers ; 

 and, like other creepers, they have not very large or 

 powerful wings, and their feet are formed for perching, 

 which is not the case with either the swifts or the hum- 

 ming-birds. When a sun-bird wants to suck the honey 

 of a flower, it does not hover in front of it, poised upon 

 swiftly vibrating pinions, like its supposed American 

 allies ; but it perches first upon the stalk or branch, and 

 then extracts the nectar at its ease. The humming- 

 birds, on the other hand, being developed insect-eaters, 

 never alight, but catch their food upon the wing, just as 

 their ancestors the swifts were accustomed to do. More- 

 over, they are not to any great extent honey-suckers ; 

 what they seek in the nectary is not so much the honey 

 as the insects which have come to eat it. These they 

 can extract with their long tongues at a single flick, and 

 then they dart away again, just like the swallows, in 

 search of more. Mr. Wallace has shown that young 

 humming-birds starve upon honey, but live and thrive 

 upon insects alone ; being, in fact, as he puts it, still in 

 the swift stage of their development. 



As for the points of convergence between the hum- 

 ming-birds and the sun-birds, those are easily enough 

 explained. Both races feed upon long-tubed tropical 

 flowers, probing their recesses in search either of honey 

 or flies ; and both, consequently, require long bills and 

 extensile tongues. Both races also possess brilliant 

 plumage, with metallic crests or gorgets ; and such brill- 

 iance is common among all flower - feeding and fruit- 

 eating species, such as butterflies, rose-beetles, toucans, 

 parrots, and birds of paradise. The constant association 

 with colored objects, and the constant search for them as 

 food, seems to arouse a taste for bright color in the creat- 



