Fine structure of the septal pore apparatus in Polyporus tomentosus, Poria latemarginata, and Rhizoctonia solani

Abstract
The septal pore apparatus was studied in Poria latemarginata, Polyporus tomentosus, and Rhizoctonia solani. Fixation by potassium permanganate was compared with fixation by glutaraldehyde – osmium tetroxide. Potassium permanganate reduced the size of the septal swelling about 50% and destroyed much of the internal integrity of the septal swelling. In glutaraldehyde – osmium tetroxide fixed material, a fibrillar network extended from the cross wall throughout the septal swelling. Except for this network, the septal swelling was electron transparent and similar in appearance to a vacuole. A rim of electronopaque material, attached to the septal swelling, surrounded the pore mouth in Polyporus tomentosus and Rhizoctonia solani.