English: A, Drawing from a section of the mature chorio-allantoic placenta of the Australian skink Egernia cunninghami carrying developing young, showing the maternal capillaries closely adjoining the allantoic capillaries on the fetal side. B, Drawing from a section of the immature chorio-allantoic placenta of the Australian skink Egernia entrecasteaux. The section illustrates the folded placental face likely involved in releasing histotrophic material that can be taken up by the chorionic ectoderm. Note also the close apposition of maternal blood capillaries with the epithelium of the reproductive tract.