he better way, although they do not always practice
it.

In this struggle the animals have an advantage over the plants, for if
food fails in one place they can move to another. Among the animals also
the mother tries to protect her children; and, in the case of some,--the
wolf, for example,--a number will hunt together for the common good.

It is quite different with the plants. They must grow where the seeds
take root. If there is little sunlight or water or the soil is poor,
they must make the best of what they have.

The plants have to struggle not only with such enemies as insects,
winds, fire, and browsing animals, but with each other, for every tree
is the real or possible enemy of every other tree. Brother seeds
sprouting under the same parent maple struggle with each other for the
food and moisture in the soil and for the best place in the sunlight.
The one that gets the most of these will grow the faster and choke some
of its weaker brothers.

[Illustration: _Edward S. Curtis_
Trees that struggle with cold and storm.]

In yonder grove of pines there are trees of all ages and sizes. The
older ones have much the advantage and take a part of the food and
sunlight that the smaller ones require. How the little ones stretch
up and grow tall and slender in their attempt to get the sunlight!
But in spite of all their efforts some of them must die.

Some kinds of trees grow faster than others. Where a number are
springing up together, the slow-growing ones will stand less chance of
ever becoming great trees. In this way the yellow pine sometimes chokes
out the cedar, and the fir gets the advantage of the sugar pine.

The bright, warm sun is the enemy of the tree that loves the shady
hillsides. The swamp is the enemy of the tree that must have loose, dry
soil. The cold is the enemy of the tree that is used to a hot climate.
Is it not strange that what is good for one tree is an enemy of another?

Many kinds of trees have their own particular insect enemies which
attack them and no others. Some of these insects live upon the leaves,
others eat the sapwood under the bark, while a few attack the roots.
Certain insects burrow in and eat the heartwood. Although this does not
always kill the tree, it weakens it and makes the wood unfit for use.
The cedar and the hickory are among the trees injured in this manner.

The foliage of the broad-leaved trees is the delight of many insects.
They sometimes eat the leaves