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 Hirwido rustica. 
have been described by Parker, Shufeldt, Lucas, Ridgway 
and other competent anatomists. In their ffigithomiarhous 
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 Cypselidm (Cat. B. Brit. Mus. xvi. pp. 434-518), 
Wing-bones of Micropus apus. 
divides the Family into three Sub families : the Cypselina, or 
True Swifts, with feathered toes and only three phalanges to 
the outer and middle toes ; the ChaturincB, 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 'free Swifts {Macropterygince), with a long 
forked tail, not exceeded by the wing. It is not, however 
necessary to enter further into the differences of the three 
