The studies were carried out on the medullae oblongatae of four European bisons. Preparations made by means of the Golgi technique, as well as preparations stained by the Klüver-Barrera methods, were used. Two types of neurons were distinguished in nucleus olivaris inferior of the European bison. Type I (about 90% of neurons) are multipolar cells whose perikaryons measure from 25 to 40 microns. The multipolar cells generate 5-6 thick dendrites which next give off a number of branches. The dendritic tree is ball-shaped. A single long, thin axon arises from the surface of the perikaryon or branches from the initial segment of one of the dendrites. The axon adopts a course along the plane corresponding to the transverse section of brain stem. Type II (about 10% of neurons) are pear-shaped and rounded cells measuring from 25 to 30 microns. These cells generate 2-3 thick dendritic trunks which are concentrated at one pole of the perikaryon. The dendritic tree has a stream-like form. A single short and rather thin axon emerges from the surface of the perikaryon. Its course corresponds to the long axis of brain stem.