Ultrastructure of the chorioallantoic placenta of the springhare (Pedetes capensis larvalis Hollister)

Abstract

The ultrastructure of the springhare placenta (Pedetes capensis larvalis) has been described. The interhemal membrane consists of the fetal capillary endothelium, syncytial trophoblast and maternal capillary endothelium with a relatively thick basal lamina. In some areas a layer of cellular trophoblast intervenes between the fetal endothelium and the syncytial trophoblast. The placentation of the spring-hare is therefore of the endotheliochorial type and not hemodichorial as previously reported in the literature. Both the cellular and syncytial trophoblast have well developed organelles which include Golgi complexes, mitochondria and endoplasmic reticulum. Their cytoplasm is also rich in secretory granules and lipid droplets. It is suggested that these cells are actively engaged in secretion and storage of glycoprotein substances.