Intramedullary ascending fibers with cells of origin in the upper three cervical dorsal root ganglia, were found to terminate in the region of the descending vestibular nucleus in the cat (Corbin and Hinsey, '35). Similar terminations arising from cells situated in the first cervical dorsal root ganglion were observed in the rabbit by Yee and Corbin in work now in progress. Because of the importance of the upper cervical dorsal roots in the cervical tonic and righting reflexes (Magnus, '24)' further knowledge has been sought relative to the intramedullary termination of fibers arising in the upper cervical dorsal root ganglia in the monkey.
The hypoglossal and accessory nerves also were studied in these experiments to determine the presence or absence of a sensory contribution from the second cervical dorsal root ganglion to these cranial nerves. Windle ('31) concluded that the spinal portion of the eleventh cranial nerve in the cat and the monkey is a mixed nerve. He obtained evidence in the cat indicating that sensory components in the accessory arise from neurons situated along the nerve itself and in the first cervical dorsal root ganglion. Windle and De-Lozier ( '32) concluded that these sensory components were probably concerned with the proprioceptive innervation of