ULTRASTRUCTURAL STUDIES OF THE PLACENTA OF THE EWE: PHAGOCYTOSIS OF ERYTHROCYTES BY THE CHORIONIC EPITHELIUM AT THE CENTRAL DEPRESSION OF THE COTYLEDON

Abstract
Extravasated maternal blood, which escapes from capillaries and larger blood vessels within the tips of the maternal septa, was responsible for the characteristic pigmentation of the central depression of the ovine cotyledon in the last 3rd of pregnancy. The chorionic epithelium of this region was actively engaged in the uptake and subsequent breakdown of maternal erythrocytes, which may represent an important source of Fe for the fetus during the period of maximum intra-uterine growth.