Cerebellar control and trigeminal afferents appear to have both, individually or in coordination, determining roles in the regulation of motor activities such as suction, mastication, vocalization and speech (see Luschei and Goldberg, 1981; Grillner et al., 1982). Assuming the functional importance for such motor activities of close relationships between trigeminal afferents, paleocerebellum and trigeminal, facial and hypoglossal efferents, we began a series of experiments, using both electrophysiological and neuroanatomical methods.