The present publication on karst hydrology and physical speleology combines two subjects which have up to now been treated separately. The two fields of knowledge have gone their separate ways, less as a result of differences in subject matter than of varying approaches. The focal point in karst hydrology lies in the description of subter ranean water with its physical and chemical properties, whereas physical speleology de scribes subterranean cavities with their contents (air, water, and sediments), which gen erally have been created by water. Such cavities can be correctly interpreted only...