This newly-revised edition of a classic introduction to speleology covers the latest discoveries about the mysterious world of caves. Drs. Moore and Sullivan are among the founders of modern cave research. They present here the principles of speleology in language that anyone can understand. The authors show how cave processes involve biological as well as geological, chemical, and physical processes, and they examine such topics as the origin of caves, the structure of cave food chains, and the evolution of blind cave animals. The book was a selection of the Science Book Club and is widely used as a textbook in high schools and colleges.