Cover photograph (Copyright © 2002, American Society for Microbiology. All Rights Reserved.): Urea silver nitrate staining of a longitudinal thick section of the extensor digitorum longus muscle, with a muscle spindle centered in the image. The nonselective silver stain is preferentially taken up by the annulospiral sensory endings in the equatorial region of the intrafusal muscle fibers. The muscle spindles are lost in the muscle-specific deletion of ErbB2. (See related article in April 2002, issue 13: vol. 22, p. 4714.)