es which lay crumbling
beneath them,--an instance of conditions which have enabled Sequoias to
crowd out the pines.

I also noted eighty-six vigorous saplings upon a piece of fresh ground
prepared for their reception by fire. Thus fire, the great destroyer of
Sequoia, also furnishes bare virgin ground, one of the conditions
essential for its growth from the seed. Fresh ground is, however,
furnished in sufficient quantities for the constant renewal of the
forests without fire, viz., by the fall of old trees. The soil is thus
upturned and mellowed, and many trees are planted for every one that
falls. Land-slips and floods also give rise to bare virgin ground; and a
tree now and then owes its existence to a burrowing wolf or squirrel,
but the most regular supply of fresh soil is furnished by the fall of
aged trees.

The climatic changes in progress in the Sierra, bearing on the tenure of
tree life, are entirely misapprehended, especially as to the time and
the means employed by Nature in effecting them. It is constantly
asserted in a vague way that the Sierra was vastly wetter than now, and
that the increasing drought will of itself extinguish Sequoia, leaving
its ground to other trees supposed capable of nourishing in a drier
climate. But that Sequoia can and does grow on as dry ground as any of
its present rivals, is manifest in a thousand places. "Why, then," it
will be asked, "are Sequoias always found in greatest abundance in
well-watered places where streams are exceptionally abundant?" Simply
because a growth of Sequoias creates those streams. The thirsty
mountaineer knows well that in every Sequoia grove he will find running
water, but it is a mistake to suppose that the water is the cause of the
grove being there; on the contrary, the grove is the cause of the water
being there. Drain off the water and the trees will remain, but cut off
the trees, and the streams will vanish. Never was cause more completely
mistaken for effect than in the case of these related phenomena of
Sequoia woods and perennial streams, and I confess that at first I
shared in the blunder.

When attention is called to the method of Sequoia stream-making, it will
be apprehended at once. The roots of this immense tree fill the ground,
forming a thick sponge that absorbs and holds back the rains and melting
snows, only allowing them to ooze and flow gently. Indeed, every fallen
leaf and rootlet, as well as long clasping root, and prostrate tr