he most precipitous torrents he
traces with the same rigid fidelity, swooping down the inclines of
cascades, dropping sheer over dizzy falls amid the spray, and ascending
with the same fearlessness and ease, seldom seeking to lessen the
steepness of the acclivity by beginning to ascend before reaching the
base of the fall. No matter though it may be several hundred feet in
height he holds straight on, as if about to dash headlong into the
throng of booming rockets, then darts abruptly upward, and, after
alighting at the top of the precipice to rest a moment, proceeds to feed
and sing. His flight is solid and impetuous, without any intermission of
wing-beats,--one homogeneous buzz like that of a laden bee on its way
home. And while thus buzzing freely from fall to fall, he is frequently
heard giving utterance to a long outdrawn train of unmodulated notes, in
no way connected with his song, but corresponding closely with his
flight in sustained vigor.

Were the flights of all the ouzels in the Sierra traced on a chart, they
would indicate the direction of the flow of the entire system of ancient
glaciers, from about the period of the breaking up of the ice-sheet
until near the close of the glacial winter; because the streams which
the ouzels so rigidly follow are, with the unimportant exceptions of a
few side tributaries, all flowing in channels eroded for them out of the
solid flank of the range by the vanished glaciers,--the streams tracing
the ancient glaciers, the ouzels tracing the streams. Nor do we find so
complete compliance to glacial conditions in the life of any other
mountain bird, or animal of any kind. Bears frequently accept the
pathways laid down by glaciers as the easiest to travel; but they often
leave them and cross over from canon to canon. So also, most of the
birds trace the moraines to some extent, because the forests are growing
on them. But they wander far, crossing the canons from grove to grove,
and draw exceedingly angular and complicated courses.

The Ouzel's nest is one of the most extraordinary pieces of bird
architecture I ever saw, odd and novel in design, perfectly fresh and
beautiful, and in every way worthy of the genius of the little builder.
It is about a foot in diameter, round and bossy in outline, with a
neatly arched opening near the bottom, somewhat like an old-fashioned
brick oven, or Hottentot's hut. It is built almost exclusively of green
and yellow mosses, chiefly the beauti