Summary. Spermatozoa were found to persist for 6 days in the uterine lumen of rabbits. They were also seen in the uterine glands in the greater horseshoe bat, the common pipistrelle bat, the guinea-pig, the stoat, the hedgehog and the mole. Sperm heads were identified in the uterine-gland mucosa in two guinea-pigs, and additional observations are reported on their presence in the Fallopian-tube mucosa in the greater horseshoe bat and the rat. In both regions, the spermatozoa were considered to lie within cells. There was evidence of dissolution of spermatozoa in the uterine glands of the horseshoe bat, and in the Fallopian-tube mucosa of the pipistrelle bat and the rat. The uterus of one guinea-pig had localized regions of leucocytosis, probably owing to infection; in this specimen, many leucocytes containing spermatozoa were found within some uterine glands and in the interstitial tissues at distances from the glands.