however violent. The other alpine conifers--the Needle Pine, Mountain
Pine, Two-leaved Pine, and Hemlock Spruce--are never thinned out by this
agent to any destructive extent, on account of their admirable toughness
and the closeness of their growth. In general the same is true of the
giants of the lower zones. The kingly Sugar Pine, towering aloft to a
height of more than two hundred feet, offers a fine mark to storm-winds;
but it is not densely foliaged, and its long horizontal arms swing round
compliantly in the blast, like tresses of green, fluent algae in a
brook: while the Silver Firs in most places keep their ranks well
together in united strength.

The Yellow or Silver Pine is more frequently overturned than any other
tree on the Sierra, because its leaves and branches form a larger mass
in proportion to its height; while in many places it is planted
sparsely, leaving open lanes through which storms may enter with full
force. Furthermore, because it is distributed along the lower portion of
the range, which was the first to be left bare on the breaking up of the
ice-sheet at the close of the glacial winter, the soil it is growing
upon has been longer exposed to post-glacial weathering, and
consequently is in a more crumbling, decayed condition than the fresher
soils farther up the range, and therefore offers a less secure anchorage
for the roots. While exploring the forest zones of Mount Shasta, I
discovered the path of a hurricane strewn with thousands of pines of
this species. Great and small had been uprooted or wrenched off by sheer
force, making a clean gap, like that made by a snow avalanche. But
hurricanes capable of doing this class of work are rare in the Sierra;
and when we have explored the forests from one extremity of the range to
the other, we are compelled to believe that they are the most beautiful
on the face of the earth, however we may regard the agents that have
made them so.