SUMMARYCorticium incrustansv. Hohn.&Litsch. is heterothallic and of the bipolar type of interfertility. Conidia are produced on short sterigmata on vegetative hyphae. In haploid mycelium several uninucleate conidia are borne on each cell. These germinate readily to give rise to new individuals like the parent. In diploid mycelium, one conidium is borne on each cell. These spores are binucleate and give, on germination, new diploid plants.