抄録
Sixteen livers of Pontoporia blainvillei were observed macro- and light microscopically.
The liver of Pontoporia consists of left and right lobes and is cylindrical as a whole. Its cranical surface is rather flat with two eminences at the lateral ends. At the dorsal surface of the left lobe, a great U-shaped notch which is formed by the lower end of the oeso- phagus and the upper right part of the main stomch is observable, which we have designated as the oesophago-gastric notch.
The ratio of liver weight to body weight ranged from 1.9 to 3.0 per cent (average 2.6%).
The area nuda shows a triangular shape as in other cetaceans so far examined, except for Platanista which has no area nuda.
The vena cava inferior is completely embedded in the hepatic parenchym in most cases observed. Two hepatic venous sinuses, one coming from the left and the other coming from the right lobe, can be seen pouring into the vena cava inferior.
We have also compared our above mentioned results with those of other cetaceans, especially with those of Platanista and Inia.
