The present results show that 'synaptic' bodies (SB) are a heterogeneous group of organelles in the pineal glands of Artiodactyla. Basically, rod-like (ribbons) and sphere-like (spherules) SB can be distinguished. In the pig small numbers of both 'synaptic' ribbons (SR) and 'synaptic' spherules (SS) are found. In bovine and ovine pineal glands few SS but no SR were seen. The same results were obtained from animals of the same species but from different continents. This suggests that the numbers of SB are species specific rather than influenced by the different lighting conditions in Europe and in equatorial Africa.