hese parts as the "snake-bird," because
it preys upon a species of small green snake that is common on the
plains of the Saskatchewan, and of which it is fonder than of any other
food.

The voyageurs were not long in having evidence of the appropriateness of
the Indian appellation; for these people, like other savages, have the
good habit of giving names that express some quality or characteristic
of the thing itself. The bird in question was on the wing, and from its
movements evidently searching for game. It sailed in easy circlings
near the surface, _quartering_ the ground like a pointer dog. It flew
so lightly that its wings were not seen to move, and throughout all its
wheelings and turnings it appeared to be carried onwards or upwards by
the power of mere volition. Once or twice its course brought it
directly over the camp, and Francois had got hold of his gun, with the
intention of bringing it down, but on each occasion it perceived his
motions; and, soaring up like a paper-kite until out of reach, it passed
over the camp, and then sank down again upon the other side, and
continued its "quarterings" as before. For nearly half-an-hour it went
on manoeuvring in this way, when all at once it was seen to make a
sudden turning in the air as it fixed its eyes upon some object in the
grass. The next moment it glided diagonally towards the earth, and
poising itself for a moment above the surface, rose again with a small
green-coloured snake struggling in its talons. After ascending to some
height, it directed its flight towards a clump of trees, and was soon
lost to the view of our travellers.

Lucien now pointed out to his companions a characteristic of the hawk
and buzzard tribe, by which these birds can always be distinguished from
the true falcon. That peculiarity lay in the manner of seizing their
prey. The former skim forward upon it sideways--that is, in a
horizontal or diagonal direction, and pick it up in passing; while the
true falcons--as the merlin, the peregrine, the gerfalcon, and the great
eagle-falcons--shoot down upon their prey _perpendicularly_ like an
arrow, or a piece of falling lead.

He pointed out, moreover, how the structure of the different kinds of
preying birds, such as the size and form of the wings and tail, as well
as other parts, were in each kind adapted to its peculiar mode of
pursuing its prey; and then there arose a discussion as to whether this
adaptation should be conside