406 COMMON SWIFT. 



ness, while the limbs are so extremely short as 

 not to incommode in turning, while at the same 

 time they are fitted for scraping holes, and hang- 

 ing or climbing about the rocks or the walls of 

 buildings. The wings are of extreme length 

 and pointed, the consistency of the plumes almost 

 like whalebone, presenting a strong resisting 

 surface to the air ; and we should here notice a 

 structure much developed among the Hirundi- 

 nidce ; they, from their very rapid motion and 

 the minute character of their prey, would require 

 organs of vision possessing great perfection, and 

 to external appearance the eye is large, full, and 

 expressive ; from experience we also know that 

 it possesses the requisite powers for minute vision, 

 and as it is obvious that it would require some 

 protection during the very rapid evolutions of 

 the birds, we find that the feathers growing 

 between the angle and the bill are of a peculiar 

 soft but close and rigid texture, and stand up as 

 a blind to break the current induced by swift 

 motion. 



Tlje Swift, like its congeners, and the Swallows 

 in all countries, seem to attend on population, 

 brought thither, as we before remarked, by the 

 greater prevalence of food, and we now find its 

 resting places only in ruined towers or old build- 

 ings, where lapse of time has formed holes and 

 rents ; bridges, and towns and villages, also fur- 

 nish retreats ; and we have a notice in London's 

 Magazine, of their breeding in the holes of trees, 

 deserted by Woodpeckers ; but we are not aware 



