Electron microscope studies of the vasa deferentia and epididymides of various animals have emphasized the endoplasmic reticulum of the epithelial cell to a greater or lesser degree (Nicander & Schantz, 1961; Horstmann, 1962; Leeson & Leeson, 1964; Schmidt, 1964; Holstein, 1964). Recent studies (Hamilton, Jones & Fawcett, 1969; Hamilton, 1971a, b) have stressed the morphological arrangement and the functional rôle played by the smooth endoplasmic reticulum. These studies have pointed out an abundant and characteristic accumulation of smooth reticulum in the mouse and rat. We would like to report an apparently unique accumulation of rough endoplasmic reticulum in the initial segment of the epididymis of an edentate, the nine-banded armadillo, Dasypus novemcinctus mexicanus.
Adult, sexually mature armadillos were anaesthetized with an intraperitoneal dose of Nembutal. The intra-abdominal testis, epididymis and