Trees are the largest plants in the world, and the most familiar. They grow in cities and towns as well as on farms and in forests. Some trees furnish shelter and pleasant shade; others provide us with food, lumber, and raw materials for cloth, plastics, films, and paper. The paper on which this book is printed was made from wood.

Trees and Their World is an introduction to these large and important plants. It begins by telling what trees are and the families to which they belong. We then learn about sap and how it travels through roots, trunks, and branches. We find out why some trees lose their bark every year, how green leaves manufacture food, and how the whole tree makes use of it. We also discover the steps by which a tree grows, why roots have to breathe, and how seeds develop. Some seeds are covered with thick fruits, but others are provided with sails or with tufts of silk that serve as parachutes. Thanks to these tufts and sails, seeds travel to places where they can grow. Some find shade and others sunshine, while the seeds of some pines generally lodge among rocks on wind-swept mountains. There the pines prosper under conditions that would quickly kill an oak tree.

These are some of the highlights in the story of trees. The authors present it from the viewpoint and with the method employed with outstanding success in Birds and Their World and Insects and Their World. Each subject is introduced by an account of some important problem or typical incident in the life ofa tree. Then comes the discussion of the topic as a whole, always centered upon typical trees which are known to boys and girls who lived in varied parts of North America.

From the book