Nematophagous fungi: Haptoglossa

Haptoglossa heterospora Drech. is redescribed and compared with H. zoospora, which is described as new. In H. zoospora the contents of the infection thallus cleave to form primary zoospores. The encysted zoospore is homologous with the spherical primary spore of H. heterospora. The secondary glossoid spores are apparently not adhesive as previously claimed. The peculiar shape of glossoid spores is related to a unique mechanism of infection whereby infective tertiary spores are injected into nematodes in an extremely short period of time. Tertiary spores develop into separate thalli.