RT Journal Article SR Electronic(1) A1 Jeffries, Peter A1 Young, Tom W. K.YR 1979 T1 Ultrastructure of Septa in Dimargaris cristalligena R. K. Benjamin JF Microbiology, VO 111 IS 2 SP 303 OP 311 DO https://doi.org/10.1099/00221287-111-2-303 PB Microbiology Society, SN 1465-2080, AB The fine structure of the septum in the vegetative hypha of the mycoparasite Dimargaris cristalligena is described. The cross-wall, continuous with the inner electron-lucent layer of the hyphal wall, bears a central pore with a flared margin occupied by a biumbonate electron-dense plug. A globose body, surrounded by a zone of ribosome-free cytoplasm, is situated next to the septal pore on each side of the cross-wall. In the neck of the haustorium, a globose body is normally observed only on that side of the septal pore next to the appressorium. Globose bodies appear structureless; they are electron-dense when fixed in potassium permanganate and of variable electron density in aldehyde-osmium fixations. Cytoplasmic continuity is maintained through the septal pore by the plasmalemma. In the sporangiophore and sporiferous branchlets, the septal plug bears an upper globose pro-tuberance and a lower obconic one. The hyphal septum in Tiegherniomyces californicus is ultrastructurally similar to that of D. cristalligena. The possible functional and taxonomic significance of such septa is indicated., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-111-2-303