The gross anatomy of the portal vein (V. portae) and its tributaries w
as studied through anatomical methods, i.e. dissection, corrosion and
diaphanization, in 45 opossums (Didelphis albiventris). In all animals
the portal vein was formed by the junction of the cranial mesenteric,
caudal mesenteric and lienal veins (V. mesenterica cranialis, V. mese
nterica caudalis and V. lienalis, respectively). Many collateral tribu
taries were observed running into the portal venous trunk.