The effects of ligation of an isolated loop of the ductus epididymidis in the region of the caput were compared with those of the exfoliative lesion of the epididymis that follows administration of alpha-chlorhydrin to rats. Electron micrographs of the ductuli efferentes in both cases revealed early phagocytosis of apparently normal spermatozoa by the epithelial cells, followed at later intervals by invasion of macrophages and intraluminal phagocytosis. It is concluded that epithelial spermiophagy is a consequence of obstruction, whether mechanically or chemically induced.