1358 A MANUAL OF ANATOMY 



these two funiculi respectively end, but it receives no nerve-fibres 

 from the funiculi. It makes its first appearance in relation to the 

 nucleus cuneatus, and above the cuneate tubercle it is a conspicuous 

 massive bundle, which forms the lateral boundary of the lower or 

 bulbar half of the floor of the fourth ventricle. Its course is up- 

 wards, outwards, and backwards. It sinks into the corresponding 

 hemisphere of the cerebellum, and is otherwise known as the 

 inferior cerebellar peduncle. 



The restiform body is composed of fibres which are derived from 

 the following sources : 



1. The olivo-cerebellar fibres of the inferior olivary nucleus of the opposite 



side. 



2. The direct cerebellar tract of the lateral column of the spinal cord of 



the same side. 



3. The anterior superficial arcuate fibres from the nucleus gracilis and 



nucleus cuneatus of the opposite side. 



4. The posterior superficial arcuate fibres from the nucleus gracilis and 



nucleus cuneatus of the same side. 



5. Vestibular fibres from the vestibular nuclei of the vestibular division 



of the auditory nerve. 



The restiform body, from its composition, serves as an important 

 means of connection between the cerebellar hemisphere superiorly 

 and the medulla oblongata and spinal cord interiorly. 



Funiculus Cuneatus and Funiculus Gracilis. — ^These tracts are 

 prolonged upwards from the posterior column of the spinal cord. 

 As stated, each contains a grey nucleus, around the cells of which 

 the corresponding sensory nerve-fibres terminate at intervals as 

 they ascend. Towards the clava and cuneate tubercle the fibres 

 become few and are spread over the clava and cuneate tubercle, 

 finally ending in connection with the cells of the grey nuclei which 

 give rise to these prominences. 



Dorsal or Posterior Longitudinal Bundle.— The fibres of this 

 bundle {fasciculus longitudinalis medialis B.), when followed down- 

 wards into the anterior column of the spinal cord on the same side, 

 represent the fibres of (i) the ventral ground-bundle and (2) the 

 anterior marginal bundle of Lowenthal. As these fibres are followed 

 into the lower part of the bulb they form a bundle, which lies close 

 to the median raphe and directly dorsal to the corresponding 

 pyramid. This strand represents the dorsal longitudinal bundle 

 in the lower part of the bulb. The deep arcuate fibres, to be 

 presently described, pass obliquely through it to the median line, 

 where they decussate with those of the opposite side. This de- 

 cussation takes place in the interval between the right and left 

 dorsal longitudinal bundles. Having now reached the other side, 

 the deep arcuate fibres take an upward course, close to the median 

 line, as the mesial fillet. The dorsal longitudinal bundle and fillet 

 are therefore now closelv related to one another in the lower part 

 of the bulb, both lying dorsal to the pyramid, the fillet lying close 

 to the raphe. 



In the upper part of the bulb the two tracts become distinct. 



