False-colour scanning electron micrograph (SEM) of the spore-bearing structure, or sporangium, of Mycotypha africana, a fungus that causes powdery mildew. Sporangia are often elaborate in shape, & this one is formed like a bottle brush. The sporangium is seen amongst the hyphal filaments of the fungus. Powdery mildew is a common plant disease caused by a number of fungi; the generic name refers to the appearance of the infected plant, the leaves of which look as if they have been dusted with powder. Magnification: x255 at 35mm size. Gold tint. Original is BW print B250/15M. Reference: MICROCOSMOS, figure 5.32, page 105.