The nodulus (N) is the most caudal lobule of the vermis. The flocculus (F) is the most ventral part of each cerebellar hemisphere. Both floccului are connected to the nodulus by flocculo-nodular tracts (evident along the ventral edge of each flocculus). The connecting tracts constitute the basis for defining a single flocculo-nodular lobe. The flocculo-nodular lobe has extensive connections with vestibular nuclei. (It may be thought of as a fifth vestibular nucleus.)