36 PASSERES. HIRUNDINID^E. 



above, and white (often varied with dull red) 

 beneath. 



The organs of flight are developed in a very 

 high degree. Almost the whole life of these birds 

 is passed in the air ; from earliest " morn to dewy 

 eve," we see them careering along in their rushing 

 flight, and, as has been truly observed, they " dash 

 along apparently as untired when evening closes, 

 as when they began their aerial evolutions with 

 the first dawn of day." They even drink on the 

 wing; sipping tBfc pool or stream as they skim 

 lightly over its surface. The feet, therefore, 

 being little called into action, are small and weak ; 

 yet, as these birds frequently cling from rocks 

 and walls, when they do rest, their toes are fur- 

 nished with sharp and crooked claws, and the 

 hind-toe can, either wholly, as in the Swifts, or 

 partially, as in the common Chimney Swallow, be 

 brought to point forward. 



The Swallows, though widely dispersed over the 

 globe, are eminently children of the sun : they 

 extend, it is true, over the temperate zone, and 

 even reach the Arctic Circle, but it is only in the 

 summer season ; on the approach of cold weather, 

 they retire to the torrid climes of equatorial 

 regions. The Swift, which is the most impatient 

 of cold of our visitors, does not appear in Eng- 

 land until May, and hastens to depart before the 

 end of August. In almost all the European lan- 

 guages the connection of these birds with a bright 

 and fervid sun, is embodied in the well-known 

 proverb, 



" One Swallow does not make a summer." 



