uis certus et uniusmodi, et in suo cuique
genere incessus est: aves solae vario meatu feruntur, et in terra, et
in aere."

SELBORNE, _Aug._ 7_th_, 1778.

Dear Sir,--A good ornithologist should be able to distinguish birds by
their air as well as by their colours and shape, on the ground as well as
on the wing, and in the bush as well as in the hand. For, though it must
not be said that every species of birds has a manner peculiar to itself,
yet there is somewhat in most _genera_ at least, that at first sight
discriminates them, and enables a judicious observer to pronounce upon
them with some certainty. Put a bird in motion

"--Et vera incessu patuit--"

Thus kites and buzzards sail round in circles with wings expanded and
motionless; and it is from their gliding manner that the former are still
called in the north of England gleads, from the Saxon verb glidan, to
glide. The kestrel, or wind-hover, has a peculiar mode of hanging in the
air in one place, his wings all the while being briskly agitated. Hen-
harriers fly low over heaths or fields of corn, and beat the ground
regularly like a pointer or setting-dog. Owls move in a buoyant manner,
as if lighter than the air; they seem to want ballast. There is a
peculiarity belonging to ravens that must draw the attention even of the
most incurious; they spend all their leisure time in striking and cuffing
each other on the wing in a kind of playful skirmish, and, when they move
from one place to another, frequently turn on their backs with a loud
croak, and seem to be falling to the ground. When this odd gesture
betides them, they are scratching themselves with one foot, and thus lose
the centre of gravity. Rooks sometimes dive and tumble in a frolicsome
manner; crows and daws swagger in their walk; wood-peckers fly _volatu
undoso_, opening and closing their wings at every stroke, and so are
always rising or falling in curves. All of this genus use their tails,
which incline downward, as a support while they run up trees. Parrots,
like all other hooked-clawed birds, walk awkwardly, and make use of their
bill as a third foot, climbing and descending with ridiculous caution.
All the _gallinoe_ parade and walk gracefully, and run nimbly, but fly
with difficulty, with an impetuous whirring, and in a straight line.
Magpies and jays flutter with powerless wings, and make no despatch;
herons seem encumbered with too much sail for their light bodies, but
thes