Thus it is apparent that there is an analogy between the structure of the cerebellum and that of the cerebrum and its application at this time will assist us to understand those parts of the pens \Tarolii and medulla oblongata which are associated in the comparison.
The sheet of gray matter which covers the surface of the cerebellum, and dips into its fissures, is analogous to that which covers the hemispheres of the cerebrum, and may therefore be called the hemispherical ganglia of the cere bellum. The enclosed mass of white matter, composed of the interlacing fibres of the middle peduncle and the corpus dentatum, constitute the corona radiata of the cerebellum The corpora dentata, associated with the sensory tracts of the cerebro spinal axis, correspond to the internal basal ganglia of the cerebrum, and, as we shall see subsequently, the external basal ganglia of the cerebellum are displaced, and are located in the pous Varolii. The superficial layer of the pons unites the opposite hemispheres of the cere bellum, and is the analogue of the corpus callosmn of the cerebrum. The deep layers of fibres of the middle
peduncles terminate in the gray matter of the pous Varolii, and correspond to the motor tracts of the internal capsules of the cerebrum, and the cruste of the crura cerebri. The superior and inferior peduncles of the cerebellum are inter rupted in their passage by the corpora dentata, thus they coincide with the tegmentum of the cruse cerebri. The direct connection of the cerebellum with the spinal cord, by means of the direct cerebellar tract and the arciform fibres of the medulla oblongata, may correspond with the fillet of the cere brum, completing the analogy between these large masses of cerebro spinal axis. Taken together, the superior pedun cle, the internal portion of the middle peduncle, and the inferior peduncle of the cerebellum, strikingly correspond to the several elements which enter into the formation of the internal capsule of the cerebrum.
By the use of the above analogy the study of the con necting parts is made easy.