We treat the beautiful earth on which we have been placed in a most thoughtless manner. We think only of what we want now, and forget that another year is coming in which also we shall want some of the earth's treasures. If we take only the surplus which each year produces, there will always be enough for us and for the people who live after us.
CHAPTER TWENTY-THREE
NATURE'S PENALTY FOR INTERFERING WITH HER ARRANGEMENTS
Nature seems very prodigal in her ways. She is continually creating on the earth a great multitude of living things, far more than there is room for. Each one of these, if it would live, must have a certain amount of air, sunshine, and food. As there is not enough of these things to supply every one, there arises a struggle. Those that are weakest die, because they are not able to get what they need. To us this seems hard, but it is Nature's way.
And further, since many of the animals feed on the flesh of other animals, the latter have, in addition to the struggle for their food, to watch constantly for their lives. Every organism is in one sense the enemy of every other one. We do not mean that they often try to kill each other because of hate, as men do, but that they are after food to satisfy their hunger. Some of the higher animals as well as men fight for mastery, in addition to struggling for food. We hope that among men the unnecessary fighting will sometime cease, and that kindness and unselfishness will rule.
The struggle for life is ceaselessly going on around us, but so quiet is it that we are not often aware of the countless tragedies that take place. This struggle extends from the plants and animals in the pond, so small that we cannot see them with the unaided eye, upward through all the larger animals.
The struggle among all living things helps us to understand the necessity for Nature's prodigality. If the plants and animals that serve as food for others were not produced in great numbers, they would soon become extinct. It is seldom that any one kind of plant or animal, because of its many enemies, has an opportunity to spread and obtain more than its share of food and sunshine. According to Nature's arrangements, each organism does its share in keeping down the numbers of the others. This we call the "balance of Nature."
Sometimes the balance of Nature is disturbed and one particular kind of animal gets the start of its enemies and increases until it becomes a plague. This may be caused by a favorable season or by the decrease of its enemies on account of disease among them. We have read of the plagues of grasshoppers which have sometimes visited the Western states and eaten up every green thing. Plagues of rats and field mice have been known to do a great deal of damage. In such cases their natural enemies, the hawks, owls, and coyotes, may be attracted to the region from far around, because of the extra food supply. After a time they may succeed in reducing the numbers of these pests.