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Cover Illustration: Fluorescence micrograph of calcofluor-stained cell walls of the filamentous desmid Desmidium swartzii (Desmidiaceae). In land plants and their closest living relatives, the charophycean green algae, cytokinesis is coupled with the deposition of an extracellular wall. Variations in the processes of cell division and wall deposition are thought to have been important steps in the evolution of multicellularity. Hall et al. studied cell division in the filamentous Desmidiaceae, one family of charophycean algae that varies considerably in the process of cell division, to provide insight into the evolution of cell division in the lineage that gave rise to land plants. Among the Desmidiaceae, most of the variation is found in a single lineage of filamentous species (including Desmidium swartzii). In this lineage, cell division differs in the degree and order of cellular events such as the degree of elongation before cytokinesis. Sometimes this results in the formation of structure called a division vesicle. In addition, at least one novel structure, a cylinder of cell wall material deposited on the newly formed cross wall (visible left of center, at the nine o'clock position), evolved in this lineage. These results indicate that aspects of the cell shape, such as position of cellular extensions, are determined at the time of cell division. In this study, we discovered variability in a complex cellular process among multicellular (filamentous) organisms. See Hall et al.—Patterns of cell division in the filamentous Desmidiaceae, close green algal relatives of land plants, pp. 643–654 in this issue. Photo credit: John D. Hall