Abstract
The lungs of a rough toothed porpoise, Steno bredanensis, were studied from the corrosion anatomical viewpoint by preparing the corrosion cast in situ. It is the most suitable method of studying the three-dimensional relationship of the tracheobronchial tree and the pulmonary vascular tree within the lungs. There is one lobe on each side, but four secondary bronchi on the right, and three secondary ones and a cardiac impression on the left. There are three eparterial bronchi: the tracheal bronchus and the second closest bronchus to the cranium on the right side; the closest bronchus to the cranium on the left. While the pulmonary arteries go along almost the same course of the tracheobronchial tree, the pulmonary veins come intersegmentally from the peripheral parts making a four-forked convergence ventrally. One dorsal vein adds to this convergence, resulting in a five-forked form.