ore firmly. Each is straining upward to receive more sunlight.
Each is struggling with its fellows for room and means to develop its
life. Competitors in hundreds and thousands are forced to withdraw
and succumb. And even when a forest giant has defeated all
competitors and reached its full maturity it has still to maintain the
struggle and hold its own continually against other individuals
whose roots are reaching out below and whose branches are
spreading out above; against climbers who would smother it; and
against parasites who would suck its very life-blood. The battle,
moreover, is often not so much between one species and another
species as between individuals of the same species. And it is a war
which continues through life.

The struggle for existence among the plants and trees is keen beyond
imagination. And the struggle among the insects, birds and beasts,
and man for the plants and products of the trees is no less severe. So
now our impression is that of an abundant, varied and intense life in
which the individuals are perpetually struggling with one another for
bare existence.

* * *

Under these stringent and stressful conditions does each living being
come into the world. He has to battle his way through--or succumb.
Plants as well as men, and men as well as plants. So, as we look into
the structure of animals and plants, we are not surprised to find that
in order to cope with their surroundings they have developed organs
which are specially adapted to enable them to secure the needful
food, to hold their own against the competition of their neighbours,
to meet the exigencies of their surroundings, and to pursue their own
life to the full extent of its possibilities. Even plants are like sentient
beings in this respect. The sensitive tips of their roots are organs
admirably adapted for feeling their way through the soil and
selecting from its constituents what will best nourish the plant. The
leaves opening out to the air and sunshine are other organs adapted
for gathering in nourishment. And thorns and poisonous juices are
means adapted to fend off destructive neighbours. The eyes and ears
in animals are other instances of organs which enable them to see
what will serve them as food, or to hear what may be possible
enemies, and to make use of what will help them to the proper
fulfilment of their life.

We see each individual plant and animal striving to the best of his
ability to adjust himself to