THE SWIFTS. 37 



feathers instead cf twelve. The breast-bone is very small, and 

 has a high keel, indicative of a powerfully-developed pectoral 

 muscle, and the hinder margin is one-notched. 



Then, again, the bones of the wing in the Swift are peculiar, 

 the humerus being very short, the fore-arm being longer, and 

 the bones of the manus extremely long. 



These are some of the most striking differences between the 

 Swifts and the Swallows, and there are numerous others which 



Wing-bones of Hinmdo rnstica 



have been described by Parker, Shufeldt, Lucas, Ridgway, 

 and other competent anatomists. In their segithognathous 

 palate there is strong fundamental evidence that they cannot 

 be placed far from the Passerine Birds in the natural system, 

 and the Swallows are doubtless their nearest allies in the latter 

 Order. 



Mr. Ernst Hartert, who is the latest exponent of the classi- 

 fication of the Cypselidtz (Cat. B. Brit. Mus. xvi. pp. 434-518), 



Wing-bones of Micropus afus. 



divides the Family into three Sub families : the Cypselince^ or 

 True Swifts, with feathered toes and only three phalanges to 

 the outer and middle toes ; the ChfKturinc^ or Spine-tailed 

 Swifts, with the toes unfeathered, and four phalanges to the 

 outer and middle toes, the tail short and exceeded by the wings; 

 and finally, the Tree Swifts (Macropterygince), with a long 

 forked tail, not exceeded by the wing. It is not, however, 

 necessary tp enter further ir^o the cjifferences Qf the three 



