1. The hyphae of three basidiomycetes, Coprinus cinereus, Coriolus versicolor and Gloeophyllum trabeum, were stained with DAPI to ascertain their karyotic state. The process of clamp formation was observed in these fungi. 2. Hyphae and clamp connections were treated with CFW to show areas of chitin synthesis. Clamp connections show the same general pattern of chitin deposition as hyphae. Individual hyphae and clamps were treated with nikkomycin, a drug which inhibits chitin synthesis. Again, clamps behaved in a manner similar to hyphae. 3. Genomic DNA was isolated from C. cinereus and used in polymerase chain reactions to try to identify chitin synthase genes. A product was identified, but it is unclear as to whether this is a true chitin synthase gene. 4. Fungi were treated with the chitinase inhibiting drug, allosamidin. The position of branches and clamps relative to the hyphal apex was altered by this antibiotic indicating apical extension was disrupted. Allosamidin did not affect the specific growth rate of fungi in submerged liquid culture. 5. Fungi were grown under conditions of restricted calcium ion supply. With reduced calcium concentration hyphal branch frequency increased as did clamp frequency. Although the pattern of growth was affected, specific growth rate remained constant in cultures grown in submerged liquid culture. 6. The galvanotropic response of fungi was investigated. The magnitude of the response of hyphae to an electric field was dependent upon field strength, length of exposure to the field, pH and calcium ion concentration.