ies, as
far-reaching in this connection, that become manifest only after patient
observation and study. Perhaps the most interesting of these is the
arrangement of the forests in long, curving bands, braided together into
lace-like patterns, and outspread in charming variety. The key to this
beautiful harmony is the ancient glaciers; where they flowed the trees
followed, tracing their wavering courses along canons, over ridges, and
over high, rolling plateaus. The Cedars of Lebanon, says Hooker, are
growing upon one of the moraines of an ancient glacier. All the forests
of the Sierra are growing upon moraines. But moraines vanish like the
glaciers that make them. Every storm that falls upon them wastes them,
cutting gaps, disintegrating boulders, and carrying away their decaying
material into new formations, until at length they are no longer
recognizable by any save students, who trace their transitional forms
down from the fresh moraines still in process of formation, through
those that are more and more ancient, and more and more obscured by
vegetation and all kinds of post-glacial weathering.

Had the ice-sheet that once covered all the range been melted
simultaneously from the foot-hills to the summits, the flanks would, of
course, have been left almost bare of soil, and these noble forests
would be wanting. Many groves and thickets would undoubtedly have grown
up on lake and avalanche beds, and many a fair flower and shrub would
have found food and a dwelling-place in weathered nooks and crevices,
but the Sierra as a whole would have been a bare, rocky desert.

[Illustration: VIEW IN THE MAIN PINE BELT OF THE SIERRA FOREST.]

It appears, therefore, that the Sierra forests in general indicate the
extent and positions of the ancient moraines as well as they do lines of
climate. For forests, properly speaking, cannot exist without soil; and,
since the moraines have been deposited upon the solid rock, and only
upon elected places, leaving a considerable portion of the old glacial
surface bare, we find luxuriant forests of pine and fir abruptly
terminated by scored and polished pavements on which not even a moss is
growing, though soil alone is required to fit them for the growth of
trees 200 feet in height.

THE NUT PINE
(_Pinus Sabiniana_)

The Nut Pine, the first conifer met in ascending the range from the
west, grows only on the torrid foothills, seeming to delight in the most
ardent sun-heat, like a palm;