Differentiation of the hymenium in Coprinus cinereus

When first formed the hymenium of Coprinus cinereus consists of protobasidia and a scattering of cystidia. The latter arise as the terminal compartments of little-branched tramai hyphae. Paraphyses originate as branches of sub-basidial cells and insert into the basidial layer. About 75 % of the paraphyseal population inserted as meiosis was completed, the rest at later stages of development. Basidial numbers did not increase once paraphyseal insertion commenced.