Originally published in 1984, this symposium volume, the first of its kind to deal specifically with the vegetative fungal mycelium, includes articles about the pattern of mycelial growth and differentiation, the functioning of mycelia (including nutrient and water uptake), mycelial variation, intermycelial interactions and recognition systems, and the establishment and distribution of mycelia in natural systems. It thus provides a detailed account of the basic body form responsible for the vegetative spread and absorption on nutrients and water. These subjects are clearly of both academic and commercial importance, since fungi make their impact on the environment as symbionts or as decay organisms through the activities of their mycelia.