54 Trans. Acad. Sci. of St. Louis 



perches on trees or wires as Swallows do ; it aliirlits ouly 

 on perpendicular walls in holes. On account of its almost 

 incredible rai)idity of flight a Swift is of all land birds 

 the most diflicult to procure. There is little doubt that a 

 Swift flies usually at the rate of a mile a minute, and 

 since it is on the wing, when with us in summer, at least 

 ten hours, it covers daily a distance of GOO miles, ecjual 

 to a straigiit line from St. Louis to New Orleans or to 

 Puluth. Since the distance from New Orleans to Yuca- 

 tan is only GOO miles, a Swift could cross the Gulf of >rex- 

 ico in one night, from 7 p. m. to 5 a. m. 



The bird is only five and one-half inches long, but has 

 a wing spread of twelve and one-half inches. Its color is 

 a sooty brown, darkest on the head and back; the throat 

 is pale. In flight the tail is folded to a point until a 

 change is made in the direction of the flight, when the ten 

 tail feathers are spread far apart to check the force of 

 motion. In spite of the general resembhince the flight is 

 more steady and free from jerks than tliat of a Swallow, 

 the wings are used with extremely fast fluttering motion, 

 alternating with only short moments of soaring, and all 

 movements are performed with an abruptness, dis- 

 tinguished from the easy, elegant evolutions of the Swal- 

 h)w. ft is astonishing to see two creatures so little 

 rchited as Swift and Swallow i-esemble each other so 

 much, and it shows "iiow nature attains the same end in 

 (lifTerent wavs, furnisiiiiiu: similitudes in diversitv no less 

 easily than she produces a wealf h of diversity from essen- 

 tial unity." 



A bird student can soon tell a Swift from a Swallow in 

 fHght at any distance, as he can learn to i<l('ntify other 

 birds on the wing. This study is interesting and gives 

 much amusement, for we see how difTennl l>irds move in 

 (lifTerent ways tlirougli the air. Hawks and Vultures 

 spread out their broad wings and sail gracefully and 

 apparently without any effort in straight lines as well 



