For the purposes of bringing the processes of nature into the classroom so students can have direct, personal contact with them, this booklet presents examples of teaching tools useful in a general approach to environmental education. It does not deal with what should be taught about man and his environment, nor does it suggest how teachers should teach. Its purpose is to describe ways to build miniature environments for living things, using low cost materials and equipment. Through construction of aquaria and terraria the miniature environments for the living worlds of land and water are developed. Well detailed as to the background, construction, content, and use of such enclosed environments, the booklet continuously emphasizes the basic elements and processes of nature which are vital to all ecosystems. (BL)