Een endoparasiet in Spirogyra

A fungus belonging to the genus Lagenidium (Phycomycetes), according to Dr. F. K. Sparrow probably L. gracile Zopf, was found parasitizing a species of Spirogyra, probably S. setiformis (Roth) Kütz. It was collected in a ditch with turbid water near Wageningen. The young zygospores of the Spirogyra appeared arrested in their development or even destroyed by the fungus. The fungous thallus consists of coralloid, 5-8 µ wide, dispersedly septate hyphae. Extramatrical discharge tubes of the sporangia occurred. Several Spirogyra cells contained thick- and smooth-walled resting spores of the fungus, 18-21 µ in diameter.