Aquatic hyphomycetes were discovered 50 years ago by C.T. Ingold. They remained a relatively obscure group until their role as intermediaries between deciduous leaves and stream invertebrates was established some 20 years ago. This book, for the first time, provides a comprehensive summary and critical evaluation of the biology and ecology of these organisms. Aspecial effort was made to evaluate the potential and actual insight that have been or will be derived from work in related disciplines such as the ecology of other fungal groups, stream ecology, or population ecology. The topics treated include the basic life history of the fungi and the potential role of wood, a discussion of how the fungi have adjusted to life in running water, their interactions with invertebrates, the attachment and germination of their spores, what is known about sexual reproduction, how water chemistry may influence their distribution and activity, how they react to human degradation of their environment, and a summary of the research done on the Indian subcontinent. The volume is of special interest to mycologists and stream ecologists and should facilitate the entry of new workers into this exciting area.