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- 
nid(B ; 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. 
The 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 Loudon’s 
Magazine, of their breeding in the holes of trees, 
deserted by Woodpeckers ; but we are not aware 
