The accompanying illustrations gives a graphic picture of the physical properties of a tree. There are three primary parts to a tree: the roots, the trunk, and the crown. The roots extract from the soil the water and mineral salts needed by the tree in its growth. They also store up the food manufactured by the leaves, and hold the tree firmly in place. The trunk is the main body of the tree from which lumber is manufactured. Each year a new layer of wood is added to the trunk of the tree. These layers produce the "grain" and "figure" of the wood.

The crown embraces the branches, leaves, flowers, and fruit. Water and sunshine give life to the tree and are limiting factors in its growth.

It is not our purpose to go into a great deal of detail with regard to tree growth since this is a specialized study. The illustration is included to give a general picture of the physical make-up of a tree and to form a basis for the study which follows of the beauty and usefulness of many kinds of woods found in the United States.

(Illustrated by U. S. Forest Service)

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