Mutant males produce motile sperm in amounts and with motility indistinguishable from wild-type males, and they transfer the sperm to their female partners. However, the sperm are not efficiently stored in females. No morphological defects are observed in the ejaculatory organs of mutant males and they show peristaltic movements indistinguishable from those observed in wild-type ejaculatory organs. The accessory glands of mutant males show defects; the glandular content is less homogeneous than wild type in intact glands, with numerous round masses. After breaking the gland, two types of round and elongated granules found in wild-type males are not seen in mutant males, and instead large granular masses are present and the glandular content is more viscous than normal. The morphology of the main cells of the mutant accessory gland is similar to that of wild type, although the cells are thicker and the gland appears wider than normal. Wild-type females mated to mfs(1)6E^P males remain receptive to further mating and do not show stimulation of egg laying. However, in one case, a wild-type female mated to a mfs(1)6E^P male laid eggs on the first day after mating. These eggs developed into larvae.