628 



the vestibular nerve is T-shaped, of whicli the ascending fibres coii- 

 tinne into tiie cerebeUnm. They unite into bundles, between which 

 is found gray matter, belonging to the nucleus of Deiters. These 

 bundles form the greater part of the corpus juxta-restiforme and 

 pass with the fibres of the corpus restiforme into the cerebellum, 

 where they end in the dentate nucleus and in the nucleus tecti. 

 Jelgeksma ') too points out (p. 2 J 7) the fibres of the nervus vesti- 

 bularis as thick bundles running through and along the bracchium 

 conjunctivum inferius towards the cerebellum, being everywhere 

 visible as distinct l)undles. W[NKI,eh is of a different opinion and 

 thinks from sections, whicli he possesses, he can make out that the 

 nervus vestibularis does not stand in direct connection with the 

 cerebellum, but that tiie fibres all end in the corpus juxta-restiforme, 

 around cells of the nucleus of Deiters. the nucleus triangularie, of 

 the proper nucleus of the radix descendens N. VIII. Cells of middle 

 size, lying in the regions of these nuclei, carry the impulses through 

 the curpus juxta-restiforme towards the cerebellum. It does not receive 

 direct nerve-roots of the N. VIII. 



In this case therefore the connection has to take place by means 

 of an interjacent link. 



As to the physiological function, the investigators of this region 

 are almost of the same opinion, that the vestibular organ will be 

 an onjan for the muscle tone and for the e(/nilibriujn. 



Its great importance for our ecpiilibrium has gradually and regu- 

 larly come to the foreground, even so, that Goltz made a sixth 

 0)'gan of it. ") 



We may say, therefore, recapitulating in short the above mentioned 

 that from the spinal cord as well as from the vestibular organ, 

 strong tracts run to the cerebellum and that interruption of these 

 disturbs the equilibrium. 



In my investigations 1 thought I was allowed to start ,from the 

 standpoint, even although from both organs paths go to the cere- 

 bellum, yet the diflference between the stimuli which they conduct, 

 is so great, that it could perhaps show me the way in the intricate 

 mass of the cerebellar phenomena. 



Thus, as the spinal path, taking its origin in the peripheral nervous 

 system, enters the spinal cord through the posterior nerve roots and 

 i.a. as the thick posterior fibres of the roots send their collateral 

 fibres to the column of Clark and the area nuclei intermedii, I 

 thought I could best study the disturbance in the ecpiilibrium when 



1) G. Jelgersma. De functie van het cerebellum. Psych, eu Near. bl. 1915. 



2) H, ZwAAEDEMAKEE. Physiologlc. Do Ei'vcn F. BoHN. Haarlem 1915. bl. 286, 



