In cultures of cells which have been on sporulation medium for 22 h, all stages of meiosis and sporulation occur. In electron microscopy of glutaraldehyde-fixed cells, spindles and spindle-pole bodies are preserved but chromosomes and kinetochores are not apparent. Photographic records of complete serial sections of some 40 asci in different developmental stages show that during the first meiotic division, the nuclear envelope remains intact and the spindle elongates from about 1 μm to 4 μm. Each of the spindle-pole bodies then divides and the bilobed nucleus contains two short spindles (one in each lobe). During the second division the spindles elongate from about 0.5 μm to 3.5 μm while the nuclear envelope remains intact. As a result there is a four-lobed nucleus, either in a chain formation or in a more compact arrangement. The spindle-pole bodies increase in complexity to varying degrees during the second division. One becomes the organizer of a complete ascospore wall while the other three may develop an incomplete wall and eventually these three nuclei degenerate in the cytoplasm of the ascus. It is shown that the nuclear behavior during meiosis parallels that of the yeast Saccharomyces cerevisiae but differs from that reported for Euascomycetes.