56 CYPSELID^E : SWIFTS. 



FAMILY CYPSELID^E: SWIFTS. 



CHIMNEY SWIFT. 



ClLETURA PELASGICA (L.) Step/I. 



Chars. General color sooty-brown, with a faint greenish gloss 

 above; grayish-brown below, becoming paler on the throat ; 

 wings black. Length, 5.00-5.25 ; extent, 12.50 ; wing, 4.75-5.00 ; 

 tail, 2.00 or less, with spine-like tips of the feathers. 



One of the most interesting modifications of bird- 

 structure is that by which the Swifts, belonging to an 

 order of birds entirely different from Swallows in es- 

 sential points of structure, are moulded to an exterior 

 shape so closely simulating the form of a Swallow, that 

 most persons believe them to be of that kind of bird : 

 and " swallows" they are almost universally called. The 

 resemblance is indeed striking ; but it only illustrates 

 how cunningly nature, in some sportive mood, furnishes 

 similitudes in her endless diversity no less easily than 

 she fashions a wealth of diversity from essential unity. 

 Humor has been defined as a perception of grotesque 

 resemblance between incongruous things, and Swifts are 

 amongst numberless conundrums which nature pro- 

 pounds through her feathered creations. "Why is a 

 Swift like a Swallow ?" I give it up and I doubt that 

 any one can answer the question. 



The most remarkable thing about the exterior con- 

 formation of the Swift is the spines which project from 

 the ends of the tail-feathers, and serve as props to stay 

 the bird while clinging with its sharp claws to the verti- 



