Food and drink, the very houses we live in and heat, medicines and drugs, books and pictures, musical instruments and tires for automobiles, all these and hundreds of our daily needs depend upon the fact that plants of many different kinds grow upon the earth and in sufficient amounts to be of importance. It is easy to say in opposition to this that we get much food from animals, that we can drink water, and that neither of these comes from plants. But water would soon be lost to us if forests did not conserve it, and upon pasturage most of our food animals depend for their life. The discovery of a single tree in the mountains of northern South America made possible for white man the malarial regions unfit for him before the advent of quinine. Just before Shakespeare’s time sugar and tea and coffee became regular articles of commerce. Not until the discovery of America was tobacco, Indian corn, chocolate, the pineapple or the potato known to man. Upon the spruce forests in the north depends much of our paper supply, from cotton we get clothes and explosives, from hemp and sisal ropes, from a single kind of Brazilian tree most of our rubber, and from rice a food that sustains nearly half the world. While it is thus plain enough that life depends upon plants now present upon the earth it may not be so obvious that from certain ancient forests has come the greatest source of artificial heat in the world. Coal is nothing but the partial decomposition of vast forests, living ages before man was first found upon the earth, subsequently buried, and under the earth’s pressure forming soft coal, or where the pressure was severe enough hard coal. When it is remembered that a dead, partly decayed tree is only a fraction of its living size and that coal is found in many parts of the world in tremendous quantities we get a partial glimpse of what our debt is to a great forest that lived in luxuriance no one knows how many millions of years ago, reached its climax, and upon whose embedded remains we depend for heat. Later on in this book will be given in greater detail some of the plants useful to man and just how we have used them. Hardly any part of the study of the plant kingdom has so much of interest as that dealing with our utilization of the things that grow about us. From the earliest struggles of our half-savage ancestors to grow definite crops rescued from the wild down to our modern nut butter made from the partly fermented meat of the cocoanut and shipped half round the world before it is refined, man has constantly striven to use for his advantage the plants most likely to prove valuable. Countries and empires have been built upon such facts. Even to-day rubber from the Straits Settlements and palm oil from Africa are deciding the economic life of those countries.