OF BIRDS. 
1S7 
Their plumage, though not beautiful in itfelf, 
is glofled with different ffiades, fo as to (hew a 
change of colours, in different points of view. 
The mouths of the Hirundo genus, or Swallows, 
are not like thofe of the Goatfucker, furniftied 
with a vifeous, or clammy fubftance, to retain the 
flies and infedts that they once have taken into 
their beaks : this is unneceffary to the Swallow 
tribe, whofe fight is remarkably quick ; they feize 
the flying infects by a fudden fnapping of the man¬ 
dibles, which can be heard at a diftance. 
Swallows are very fociable birds; they come, 
and fly, and migrate in conflderable flocks, and 
in i’ome degree perform the kind offices of focial 
life, by affifting one another in the conftrudtion 
cf their neffs. 
Their neffs in general are formed with confide- 
rable care, and intelligence. Some fpecies build iu 
(he holes of walls, or in holes which they them- 
felves prepare in fand rocks : they make the ca¬ 
vities fufficiently deep to infure the fafety of their 
infant brood, and carry them fuch materials, as 
may enable them to lie foft and warm, and at 
their cafe ; others again build againft houfes. 
The flight of the Swallow is rapid, yet eafy, 
and continued; and indeed, this feems its na¬ 
tural ftate ; it eats, drinks, and bathes, and evea 
feeds its young upon the wing. 
It 
