Morphology and ultrastructure of the chorioallantoic placenta of the Iberian mole (Talpa occidentalis) with special reference to heterophagous areolas and the nature of interhaemal barrier

伊比利亚葡萄胎（Talpa occidentalis）绒毛尿囊胎盘的形态和超微结构，特别关注异食性乳晕和血间屏障的性质