The distribution of spermatozoa in the oviducts of domestic hens, at various times after artificial insemination or copulation, confirmed and extended previous observations regarding the speed with which spermatozoa may traverse the uterovaginal junction and ascend the oviduct. These spermatozoa disappear within less than 24 hr. Thereafter, spermatozoa are ordinarily found only in the uterovaginal glands except about the time of oviposition or ovulation. They presumably reenter the oviduct lumen, under the influence of oviposition or ovulation. Spermatozoa were found in considerable numbers on the vitelline membranes of eggs and occasionally in egg albumen.