HUMMING-BIRDS 337 



the interesting fact that the latter are essentially swifts 

 profoundly modified, it is true, for an aerial and flower- 

 haunting existence, but still bearing in many important 

 peculiarities of structure the unmistakable evidences of a 



1 Recent researches into the anatomy of the swifts and humming-birds 

 have brought to light so many and such important differences that the above 

 conclusion, founded on comparatively superficial characters, becomes doubtful. 

 Dr. Shufeldt considers that both groups are so isolated that they each require 

 to be classed as a distinct order of birds. But while the swifts are believed 

 to have undoubted though remote affinities with the swallows, it cannot yet 

 be determined whether they have any real affinity with the humming-birds, 

 which latter appear to have no special and unmistakable relationship with 

 any other order or family of birds. See " Studies of the Macrochires, Mor- 

 phological, 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. 



