Abstract
Some structural features of the surface epithelium of the pig ovary were examined by scanning electron microscopy. There were no vesicular follicles visible on the ovarian surface of the infantile pig (13 days of age), and their surface epithelium consisted of polygonal cells that had numerous short microvilli and a few isolated cilium-like processes. In the prepuberal (6 to 7 months of age) or postpuberal pig ovary, the surface epithelium was observed at a low magnification as a continuous cellular layer. In these pigs the surface epithelium over the vesicular: follicle, generally consisted of polygonal cells covered with numerous microvilli. The presence of a small number of long cilium-like processes among the microvilli was also noted on the epithelial cells covering the follicle. The size of surface epithelial cells over a large follicle appeared to be somewhat larger than that of those over a small or a medium-sized follicle. The surface over the ovulated follicle (corpus luteum) differed in structure from the preovulated follicle. Epithelial cells covering the apical region of the ovulated follicle were scarcely observed at early metestrus, although whenever such existed, the cells possessed fewer microvilli than did the cells over the pre-ovulated follicle. In general, the cell borders at the apical region of the ovulated follicle were indistinguishable at metestrus even if cells were observed, but became distinct during diestrus. However, in other regions, the structure of epithelial cells covering. the ovulated follicle appeared to be about the same as. that of those covering the. pre-ovulated follicle. It appears that the morphological features of the surface epithelium of the pig ovary are similar to those of laboratory animals and primates.
