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On the Cover: Tracheary element differentiation involves the coordination of two developmental events: the synthesis of an elaborate secondary cell wall and programmed cell death. Groover and Jones (pp. 375-384) show that the tracheary elements' ultimate suicide is executed by an influx of Ca²⁺ into the cell, and is manifest morphologically by the rapid collapse of the vacuole and fragmentation of nuclear DNA. A Ser protease secreted during cell wall synthesis is implicated as the factor triggering cell death and coordinating the execution of cell death with wall synthesis. The execution of cell death can be experimentally manipulated, and the cover shows two daughter cells differentiating as tracheary elements that have prematurely fragmented their nuclear DNA (fragmented DNA fluoresces green within the nuclei).