Cover legend: Confocal image of a wild-type Drosophila visual system early in pupal development. All photoreceptor neurons (R1–R8) and their axons are labeled by anti-Chaoptin (red). The R7 photoreceptor neurons (green) extend axons from their cell bodies in the retina (top), beyond the plexus of R1–R6 axon terminals in the lamina, and into the developing medulla (bottom). For details on how R7s halt the growth of their axons, see the article by Kniss et al. (pages 1509–1520).