Abstract

The conducting system of the heart of the harbour porpoise (Phocoena phocoena, Linnaeus, 1758) is described macroscopically as well as microscopically. The topography and microscopy of this system in the harbour porpoise conforms to that of whales and hoofed animals. The proximal part of the common bundle and the basal parts of its branches lie not so deep to the endocardium as in the dolphin heart. Morphologically the relation between the system – especially the sinuatrial node – and the autonomous nervous system is striking.