ollars Worth of Timber Every Year
Blackened Ruins of a Fire Swept Forest
Forest Management Provides for Cutting Mature Trees
Seed Beds in a Forest Nursery
Sowing Forest Seed in an Effort to Grow a New Forest
A Camping Ground in a National Forest
Good Forests Mean Good Hunting and Fishing
Young White Pine Seeded from Adjoining Pine Trees
What Some Kinds of Timber Cutting Do to a Forest
On Poor Soil Trees are More Profitable Than Farm Crops
A Forest Crop on its Way to the Market

[Transcriber's note: "Section of a Virgin Forest" is the seventh
(not the second) illustration in the book.]

CHAPTER I

HOW TREES GROW AND MULTIPLY

The trees of the forest grow by forming new layers of wood
directly under the bark. Trees are held upright in the soil by
means of roots which reach to a depth of many feet where the soil
is loose and porous. These roots are the supports of the tree.
They hold it rigidly in position. They also supply the tree with
food. Through delicate hairs on the roots, they absorb soil
moisture and plant food from the earth and pass them along to the
tree. The body of the tree acts as a passage way through which
the food and drink are conveyed to the top or crown. The crown is
the place where the food is digested and the regeneration of
trees effected.

The leaves contain a material known as chlorophyll, which, in the
presence of light and heat, changes mineral substances into plant
food. Chlorophyll gives the leaves their green color. The cells
of the plant that are rich in chlorophyll have the power to
convert carbonic-acid gas into carbon and oxygen. These cells
combine the carbon and the soil water into chemical mixtures
which are partially digested when they reach the crown of the
tree. The water, containing salts, which is gathered by the
roots is brought up to the leaves. Here it combines with the
carbonic-acid gas taken from the air. Under the action of
chlorophyll and sunlight these substances are split up, the
carbon, oxygen and hydrogen being combined into plant food. It is
either used immediately or stored away for future emergency.

Trees breathe somewhat like human beings. They take in oxygen and
give off carbonic-acid gas. The air enters the tree through the
leaves and small openings in the bark, which are easily seen in
such trees as the cherry and birch. Trees breathe constantly, but
they digest and assimilate food only during the day and in the
presenc