Possibly there are in the brachium pontis axons of Purkinje's or the nuclear cells which terminate in the nuclei pontis on both sides and in the nuclei of the reticular formation, tractus cerebello-tegmentalis pontis.
The corpus restiforme (inferior peduncle) (Figs. 56, 103, 107 and 122) can be traced to the upper of the hemisphere and worm. Inferiorly it is the restiforth body of the medulla oblongata. It enters the corpus medullare of the cerebellum in front of the dentate nucleus and just lateral to the brachium conjunctivum. The bundles of component fibers are very numerous: (r) The dorsal spino-cerebellar fasciculus (direct cerebellar tract), whose origin is in the dorsal nucleus of the cord and termination in the superior worm, forms its central part. This is the tract of Flechsig. (2) The external arcuate fibers of the medulla (posterior and anterior) form its free sur face. They rise in the nucleus funiculi gracilis, nucleus funiculi cuneati and nucleus arcuatus and end in the vermis superior, the posterior on the same and the anterior on the opposite side. (3) A bundle from the lateral nucleus of the medulla, the reticulo cerebellar fasciculus, to the cortex of the cerebellum on the same side. (4) The olivo-cerebellar fasciculus rises in the opposite inferior olive, chiefly, but partly in the olive of the same side; it terminates in the cortex of the vermis. Some authors claim there are descending fibers in this bundle. (5) The direct
sensory fasciculus of the cerebellum is composed of root-fibers of sensory nerves, especially the trigeminal and vestibular nerves. It is closely related to the following tract. (6) The nucleo-cerebellar fasciculus rises in terminal nuclei of cranial nerves. The vestibular fibers of tracts five and six terminate in the opposite nucleus fastigii; other fibers of the restiform body end in the cerebellar cortex. The restiform body, like the brachium pontis, is a great cerebello-petal path. Brachium pontis connects cerebellum to the cerebrum; restiform body joins it to the spinal cord, the medulla and the sensory cranial nerves. The cerebellum correlates all the impulses arriving by the cerebello-petal tracts and sends out its coordinating impulses through the cerebello-tegmental system of fibers, which form the brachium conjunctivum and the fastigio-bulbar fasciculus next to be described.
In the cerebellar end of the restiform body there runs a small tract forming the bulbar part of the cerebello-tegmental fibers. This is the fastigio-bulbar fasciculus. Originating in the opposite nucleus fastigii and decussating at once, it descends chiefly to Deiter's nucleus, but some of its fibers end in the nuclei of motor cranial nerves. It constitutes a descending link in the vestibular arc of equilibrium.