come to the primeval
forests, where the giant trees stand just as they did before men came.
Here we can see how the slopes are protected, for in making the road the
workmen cut deep into the hillside. They first removed a layer of pine
needles and decaying branches. Then they cut through a layer of soil
about two feet thick which was completely filled with little roots of
trees and bushes. Below this they came to the soft subsoil, which
contained only a few roots, and at the bottom they reached the solid
rock.

The layer of roots and soil at the top of the bank, you can see from the
picture, now overhangs the road, because the raindrops which beat
against the bank have washed away all that they could reach of the
unprotected earth at the bottom. How plainly we can see the network of
roots. What a hard task it must be for the water to get at the soil in
which these roots are growing.

[Illustration: _H. W. Fairbanks_
The layer of roots holds the soil on the mountain side.]

We will now leave the road and, although it is still raining hard, we
will walk a distance through the forest and see if there is anything
more that we can learn. We are soon in the deep woods where, perhaps, no
one has ever been before. Around us are trees of all ages and sizes,
from little seedlings to great giants six feet through. Among them are
the crumbling stumps of trees long dead. Their trunks lie on the ground,
and many are so soft and rotten that we can kick them to pieces with our
feet.

As we walk our feet never touch the real earth. It is always on the
soft, yielding leaves and crumbling branches that we step. These leaves
and branches form a thick layer completely hiding the soil. But the
strangest thing is that, although the rain is still falling, we can
discover no rivulets. What, then, becomes of the water? The soft,
decaying vegetation on which we are walking and the rotting stumps and
logs act like a great sponge. As long as this sponge can take up the
falling drops, none have a chance to run away. If it rains a very long
time and the sponge becomes saturated, the drops that creep away and
finally unite in rivulets in the hollows do no harm to the soil, for
they cannot get at it.

[Illustration: _H. W. Fairbanks_
The roots of the tree grip the soil like the fingers of a great hand.]

Long after the storm has passed, the earth underneath the trees remains
wet, while the ground out in the open has become dry. A part o