Observations are described on the nuclear behaviour relative to the chlamydospore germination, sporogenesis andin vitrochlamydospore development inProtomycopsis pateliiPavgi and Thirumalachar andProtomycopsis thirumalachariiPavgi, respectively parasitic onPhaseolus mungoL. andSesbania grandifloraPers. Taxonomy and phylogenetic relationship of the genusProtomycopsisMagnus and family Protomycetaceae are discussed in the light of these observations.