The problem of functional localization in the cerebellum is one which has received considerable attention. Recent comparative anatomical studies1 and ablation experiments2 have supported a division of the cerebellum based on afferent fiber connections. Recently Dow3 has recorded action potentials in the cerebellum as a result of stimulating various afferent fiber tracts, and his results are in accord with Larsell's anatomical findings. The present work is an attempt to explore by the oscillographic method the projections of the cerebral cortex to the cerebellar cortex.Methods and Results. Twelve cats, under barbiturate anesthesia, were used in this work. The method of stimulating and recording is described elsewhere.4 Single electrical shocks were applied to the cerebral cortex by means of bipolar electrodes about 1 mm apart resting lightly on the pia. Monopolar recording was employed, the active electrode being a chlorided silver wire in light contact with the pia of the cerebellar cortex. Fig. 1 is a re...