01 September 1989
Vol 245, Issue 4921

About The Cover

An embryonic grasshopper jumping leg imaged in a laser confocal scanning microscope, computer-enhanced, and pseudo-colored. The developing nervous system is labeled with fluorescent, neuron-selective antibodies. A major leg sensory nerve (far right) has failed to connect to the central nervous system because of the absence of a single pair of pioneer neurons. See page 982. [Photograph by Monika Klose, David Bentley, and Janet Duerr]