PDF - Wallace Online

HUMMING-BIRDS 337the interesting fact that the latter are essentially swiftsprofoundly modified, it is true, for an aerial and flowerhauntingexistence, but still bearing in many importantpeculiarities of structure the unmistakable evidences of a1 Recent researches into the anatomy of the swifts and humming-birdshave brought to light so many and such important differences that the aboveconclusion, founded on comparatively superficial characters, becomes doubtful.Dr. Shufeldt considers that both groups are so isolated that they each requireto be classed as a distinct order of birds. But while the swifts are believedto have undoubted though remote affinities with the swallows, it cannot yetbe determined whether they have any real affinity with the humming-birds,which latter appear to have no special and unmistakable relationship withany other order or family of birds. See " Studies of the Macrochires, Morphological,and otherwise, with the view of indicating their relationships," etc.,by R. W. Shufeldt, M.D., in the Journal of the Linnean Society, vol. zx. ;Zoology, pp. 299, 394 : 1889.