OF THE NERVUS OCTA.VUS. 151 



At the operated side, there are found at the peripherical margo 

 of the lateral funiculus and along the exit of the anterior rootlets, 

 without doubt more black globules than in other parts of the 

 medullated parts of the medulla, but here again Marchi-method 

 has reached its limits. 



The only part, where degenerate fibres are found to a degree 

 important enough to be admitted as consequence of the operation, 

 is the anterior funiculus, though it is remarkable that in the lateral 

 part of the formatio reticularis of the medulla oblongata and along 

 the exit of the rootlets there always are found a few degenerate 

 nervefibres. 



5 ly . Returning now to the most proximal root-fibres of the dorsal 

 system, 1 have already demonstrated, that they were not distinctly 

 separated from the ascending rootfibres embracing the nucleus 

 magnocellularis. 



From the medial fibres found there, transverse fibres, passing 

 through the surroundings of the proximal top of the nucleus par- 

 vocellularis or ventrally from it, contribute to the dorsal systema. 



From the lateral fibres the ending of which among the cells 

 in the walls of the IV th ventricle, or in the most proximal part 

 of the angular nucleus, or continuing their course in the nucleus 

 pedunculi cerrebelli or even in the cortex cerebelli has been 

 described - - again transverse fibres go to the dorsal systema. 



From these proximal dorsal fibres the greater number gain the 

 fasc. long, posterior and they have found their description as ascen- 

 ding fibres therein. 



In this way rootfibres form an important dorsal system, providing 

 by means of the fasciculus longitudinalis posterior, both parvo- 

 cellular nuclei, in a slighter degree the nucleus of the VI th nerve 

 and the nuclei of the proximal eye-nuclei, whilst by means of the 

 fasciculus praedorsalis a rather considerable number of them enter 

 into the homolateral funiculus anterior of the cervical cord, going 

 through this to the antero-lateral part of the horn. 



c. Comparison between the central octavus-rootfibres in pigeons 



and in rabbits. 



If a comparison of the central octav us- system in mammalia and 

 in birds may be attempted, it is evident, that this attempt has no 

 other value, than as a more or less fortunate endeavour to homo- 

 logize the different fasciculi and nuclei, which together are forming 

 this part of the central system. 



