No. I.] 



THE VERTEBRATE EAR. 



151 



A TABLE OF THE MAIN RELATIONS OF THE VIII IN MAN. 



In Man f Leaves the brain from the groove between the pons and restiform 

 the -j body as two cords containing between them from one to several small 



VIII nerve [ nerves, the portio intermedia Wrisbergii. 



Ramus Anterior 



or 



Utricular 



Nerve. 



Portio Intermedia, 

 Wrisbergii, N. VIII. 



Ramus Posterior, 



or 



Saccular 



Nerve. 



VENTRAL, 



anterior, 



median, 



superior. 



DORSAL, 



posterior, 



lateral, 



inferior, 



inner, 



principal, 



central. 



The nucleus of this nerve lies medial from the 

 corpus restiforme; its fibres ascend to the cere- 

 bellum (Bechterew) ; in part it runs into the lateral 

 nucleus Gegenbaur. It is connected with the nl. 

 of Deiters, and the gang, geniculi (portio inter- 

 media). It passes into the brain along the ventral 

 face of the corpora restiformia, reaches further dor- 

 sad and caudad than the dorsal root. The portio 

 intermedia passes out of the brain a little in front of 

 the ventral root : it arises in the accessory nucleus. 



This root passes to the median side of the resti- 

 form body, between it and the ascending root of V, 

 and so reaches the lateral 1 (division of the) nucleus 

 among the large cells of which most of its fibres 

 end : the others are continued on to the cerebellum 

 along with the fibres of the restiform body; possi- 

 bly these fibres run into cells of the nucleus before 

 passing on to the cerebellum. 



The portio intermedia is a sensory facial branch 

 homodynamous with the utricular branch, and 

 both belong to the VII. 



The nucleus of this nerve lies laterad from the 

 corpus restiforme. None of these fibres have direct 

 connections with the cerebellum. Most of the 

 fibres end in the nucleus inferior {i.e. accessorius) 

 which is connected with the trapezoid body (Bech- 

 terew). This nl. is intimately connected with the 

 nl. of the IX. 



As it enters the brain it winds round to the 

 dorsal surface of the corpora restiformia, reaches 

 further ventrad and cephalad than the ventral 

 root. The major portion of the dorsal root ends 

 in the accessory ^ nucleus and in the nuclear mass 

 just dorsad of it (tuberculum acusticum), from 

 whence it curves around the corpora restiformia 

 and ends partly in the median nucleus after caus- 

 ing the strise acusticse. The connection with the 

 median nucleus is an association relation. 



The anterior nucleus overlaps that of the VII. 



The posterior nucleus overlaps that of the IX. 



The saccular nerve is a branch of the glosso- 

 pharyngeus. 



^ This is the dorsal nucleus of Edinger. 

 - This is the ventral nucleus of Edinger. 



