OF THE NERVUS OCTAVUS. 69 



site side of the operation. It has lost nearly all its fibres. Consequently 

 the cells are lying closer together. The cells themselves have dimi- 

 nished in size, they are shrivelled, of irregulare shape, but none 

 of them has disappeared. 



The other ventral nuclei in the tegmentum do not present such 

 intensive atrophy as the opposite trapezoid-nucleus. Yet the medul- 

 lated surroundings of the nuclei olivares superiores and their acces- 

 sory nuclei have lost a great deal of their fibres on both sides , 

 but this loss is more apparent at the operated than at the oppo- 

 site side. Cellular changes also are present in the olivary bodies, 

 but in a slight degree. 



Some cells may be diminished in size , perhaps some smaller 

 cells may have disappeared but the cellular change is by no means 

 so intensive as it is in the trapezoid nucleus. This nucleus has 

 suffered an atrophy nearly as intensive as that of the ventral nucleus 

 of the VIII th nerve , which afterwards in the discussion of the 

 ,,systerna dorsale nervi octavi" will be described. 



So, as to my experience, BAGINSKY is right. After complete 

 root-section , the root-fibres disappear totally and with them the 

 systema ventrale atrophies nearly completely in its distal end. After 

 removal of the labyrinth the ventral root does not totally lose its 

 fibres , and the atrophy of the ventral system is less intensive , may 

 even be of small intensity , but in the distal end it is always present. 



The atrophy of the systema ventrale is accompanied by a con- 

 siderable atrophy of the crossed trapezoid nucleus , whose fibres are 

 lost, Avhose cells are reduced in size, and with a remarkable loss 

 of fibres in the medullary capsule of both nuclei supra-olivares and 

 para-olivares , especially on the same side. 



In this way the results of GUDDEN'S method are accordant with 

 those given by MARCHI'S method and with those of the myelinisa- 

 tion-method. 



h. The most dorsally situated root-fibres (the stratum d) in the 



systema ventrale nervi octavi and tlieir relation to the fibres of HELD 



or the sy sterna intermedium nervi octavi', 



As soon as, after section of the VIII th nerve the degenerated 

 transverse rootfibres of the ventral system, are studied in their 

 course with MARCHI method on a series of horizontal sections of 

 the medulla oblongata , the origin of the most dorsally situated fibres 

 of this systema (the stratum d] may be settled with relative facility. 



In fig. 16 A I on plate IX reproductions are given of such a 



