1494 A MANUAL OF ANATOMY 



longitudinal bundle is brought into communication with the vestib- 

 ular nerve. Through means of the dorsal longitudinal bundle, 

 which represents the ventral ground-bundle and anterior marginal 

 bundle of Lowenthal in the spinal cord, the nucleus of Deiters is 

 brought into communication with the anterior or motor cornua of 

 Ihe spinal cord. Through means of this bundle the nucleus of 

 Deiters is also brought into communication with the nuclei which 

 control the ocular muscles — ^namely, the oculo-motor, trochlear, and 

 abducent nuclei. 



The complex nervous chains associated with the vestibular nerve 

 may be tabulated as follows: 



Cerebellar Chain. 



1. The bipolar cells of the ganglion of Scarpa. 



2. The fibres of the vestibular nerve. 



3. The dorsal vestibular nucleus, nucleus' of Deiters, and nucleus of 



Bechterew. 



4. The secondary cerebellar vestibular tract, or the direct sensory cerebellar 



tract of Edinger, leading to the superior vermis and roof-nucleus 

 of the cerebellum. 



Spinal and Oculo-Motor Chains. 



1 . The bipolar cells of the ganglion of Scarpa. 



2. The flbres of the vestibular nerve. 



3. The nuclei of Deiters and of Bechterew. 



4. The secondary vestibular tract from the nuclei of Deiters and of Bech- 



terew to the dorsal or posterior longitudinal bundle, and thence to 

 the motor cornua of the spinal cord and the motor nuclei of the 

 ocular muscles. 



The nucleus of Deiters thus has important connections as follows: 



1. The membranous 3. The motor cornua of the 



vestibule. spinal cord. 



2. The cerebellum. 4, The motor nuclei of the 



ocular muscles. 



Descending Fibres of the Vestibular Nerve. — ^As the vestibular 

 nerve passes backwards on the inner side of the restiform body, some 

 of its fibres, as stated, take a downward course. These descending 

 fibres constitute the so-called descending root of the vestibular nerve. 

 They descend through the lower part of the pons Varolii into the 

 medulla oblongata as low as the level of the cuneate tubercle. They 

 are accompanied throughout by the descending nucleus, and they 

 are usually regarded as terminating in aborizations around the cells 

 of that nucleus. Superiorly they are related to the nucleus of 

 Deiters, and some authorities have regarded them as fibres passing 

 between the nucleus of Deiters and the cuneate nucleus. 



The cochlear and vestibular nuclei originally form one acoustic or auditory 

 nucleus, which is developed from the rhombic lip. 



Ninth or Glosso-pharyngeal Nerve. — ^This nerve consists chiefly of 

 afferent or sensory fibres, which grow into the medulla oblongata. 



