Figure 5.

Placentation in the boto, Inia geoffrensis. (A) Maternal component of a placental exchange area showing uterine epithelium well supplied with capillaries (arrows). PAS. (B) The simple cuboidal uterine epithelium (ut ep) is closely underlain by the capillaries (cap). PAS. (C) Fetal villi from an exchange area showing the rich vascular supply and indentation of the trophoblast by capillaries (arrows). PAS. (D) Columnar trophoblastic epithelium with few capillaries (cap) supplied from the underlying stroma. PAS. Scale bars = 40 μm (A-B), 20 μm (C-D).