NUCLEI OF Till': Ch'AMAL NEKVl-S 



807 



cells of the superior olivary nucleus of (lie same and opposite sides. The superior 

 olive is a small accumulation of irrey substance which lies in the level of the posterior 

 portion of tlic pons. and in line with the much larger inferior olivary nucleus of the 

 medulla, llouever, it is not analogous to the latter in any sense. The two superior 

 olives form links in the central acnu.-i ic chain, From cells of the superior olivary 

 nucleus of the same and opposite sides, fibres arise which pass by way of the lateral 

 lemniseus and terminate in the grey substance of the inferior gilftdrigeminate body 

 and in the medial ireuiculale body, thus connecting these bodies with the ventral 

 nucleus of the cochlear nerve of the opposite side. From the medial geniculate body 

 fibres arise which pass to the cortex of the superior gyrus of the temporal lobe. This 

 path is supplemented by fibres arising in the inferior <iuadrigcminate body, which 

 likewise go to the temporal lube. In the lateral lemniseus some of the acoustic fibres 

 are interrupted by cells of the nucleus <>j tin- lutiml hmniscus. In crossing the mid- 

 line the fibres from the two sources form a more or less compact bundle, the corpus 



.;. r.iil. SCHEME SHOWING SOME OF THE CENTRAL CONNECTIONS OF THE ACOUSTIC NEKVE. 



(In part after Edinger.) 



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BOIIY 

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 SEK I A' 



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, M< 'LETS EMBOLfFORMJS 



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 NUCLEUS 



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MBtHAL LOXVirnu.VM. /M>'<7'V/ rs 

 LATKRAL 



LA TFI:.\ i. xrri.urs nf 



, - YKSTIHI'LAR XBKTK 



- - I.-KSTIFORM BODY 



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VS8TIBVLAS .v/.v-c/; 



sr //:/:l(tn OLIVARY XITLECS 

 \ 

 TKAI'KZOIIt BODY 



trapezoideum. To this are added fibres crossing; between the nuclei trapezoidei, 



smaller masses of irrey substance just ventral to the superior olives. 



Also, some fibres arising in the nuclei of termination of the cochlear nerve pass 

 to the inferior quadriireminate body of the same side. ( >n the other hand, the con- 

 nect ion with the medial geniculate body is thought to be wholly a crossed one. 

 Further, a few fibres are described as terminal inir in the superior yuadrigemiiiate 

 bod 1 1 of both the same and the opposite side. 



All the fibres arising in the superior olivary nucleus do not enter the corpus 

 trapezoideum and the lateral lemniseus. A small bundle, the peduncle of the 

 superior olive, arises in each nucleus ami courses dorsally to the region of the nucleus 

 of the abducens. Here certain of its fibres terminate about the cells of the nucleus 

 of the abducens, while others enter the medial longitudinal fasciculus and pass to 

 the nuclei of the trochlear and oculomotor nerves, thus establishing connections 

 between auditory impulses and eye movements. 



