84 C. WINKLER. THE CENTRAL COURSE 



strates immediately (drawn in fig. 3# and fig. 1 3# on Plate III) , 

 there is found an intense atrophy in the stratum latero-dorsale. 

 At the non operated side , this layer may be found well developed 

 with the tuberculum acusticum resting upon it. The stratum medul- 

 lare profundum and the stratum griseum profundum of this nucleus 

 the inner ring is richly endowed with medullated fibres. 



At the operated side (fig. 30) nearly all the fibres in the inner 

 ring have disappeared. The stratum griseum profundum does scar- 

 cely exist, and the stratum medullare profundum also is much 

 reduced. Because the root-fibres have disappeared, the medullated 

 fibres now found in the stratum medullare profundum must belong 

 to the system of secundary fibres. And these secundary fibres now 

 form a small trunk of small fibres originating somewhat laterally 

 from the ventral nucleus. 



Here is isolated the trunk of the secundary system from the tuber- 

 culum acusticum (fig. 3a on Plate III). 



But at the same time the ventral nucleus is much reduced in size, 

 and especially its ventro- distal portion. Here also in the first place the 

 fibre's, constituting the rootbundles in this nucleus have completely 

 disappeared, at least in its distal end, but at the dorsal and proximal 

 border fibres reappear. Therefore at its medial border, increasing 

 towards the dorsal and capital end of the nucleus, a relative strong 

 bundle is found, a second trunk of secundary fibres. 



Those two trunks meet each other at the dorsal border of the 

 area ovalis (see fig. So), the external from the tuberculum, the 

 internal from the ventral nucleus. They form together the much 

 reduced stria acustica, but now a stria acustica, wherein no longer 

 any root-fibres are exsiting. 



It is true that in normal frontal sections also the two trunks 

 of the secundary system may be demonstrated (compare fig. 13$) 

 but not so evidently, because there they are complicated by the 

 presence of the rootfibres. 



However, from the atrophied radiation of the stria acustica, it is 

 now possible to trace several systems of fibres, in their farther course. 



For instance its internal layer may be traced round the area 

 ovalis into the intermedial system. This system is much reduced, 

 now that it has lost its rootfibres, but it contains a secundary 

 system. Its outer layer may be traced in the transverse (see fig. 

 130 and fig. 13$) dorsal fibres, passing between the dorsal nucleus 



- which has lost many fibres - - and portio interim. These fibres 

 also are reduced in quantity (see fig. 130 and I3l> str. dorsale), 

 but enough of them are left to postulate an important secundary 



