Further Observations on the Fine Structure of the Spores of Glugea weissenbergi (Microsporida,Nosematidae)*

SYNOPSIS. A Glugea xenoma sectioned and viewed with the electron microscope contained many spores with everting polar filaments. Several details not seen in previous studies of this species were observed. A specialized area with the appareance of a lattice was commonly present near the anterior end of the polaroplast. The external portion of a partially everted polar filament appeared to have about twice the diameter of the part remaining within the spore. No membrane was seen limiting the external surface of the everted portion. The everting filament had pushed thru the polar cap and the adjacent thin area of the spore wall, making the polar cap into a ring. The ring connected the proximal end of the everting filament to the inner spore membrane, thereby anchoring the filament to the spore. The electron density of some of the membranous organelles of the spore was enhanced by the use of ruthenium red.