348 



rolling movement. It will he recalled, that for the forced movement 

 in the horizontal plane (circus-movement) the Commisaro-mednllary 

 bundle fills np that gap. In this bundle we can recognize Sherrington's 

 "final common path", by whatever reflex-arrangements the circus 

 movement (with the conjugated deviation of head and eyes) is provoked. 

 As a general result it may now be safely concluded, that my 

 supposition of 1902 ') proved right, that the P. L. B. system plays 

 an important role in the physiology of the forced movements, in the 

 horizontal plane (circus) and in the vertical plane, standing vertical 

 to the bodily axis (rolling). Long before this Bleuler, Duval and 

 Laborde, Caygal, Edinger Held, Boyce^) et al. had hinted to such a 

 relation; Bleuler had directly urged the need of experimental work 

 on the P. L. B., which as far as I am aware till now has been 

 neglected. Advancing knowledge of anatomical connections has, for 

 many years, made it probable, that ascending vestibnlary neura split 

 up in particular divisions of the Oculomotor Nuclei (Wallenberg =). 

 Descending fibres in the P. L. B. were demonstrated by van Gehuchten *) 

 Gee and Tooth ^j and Kohnstamm^) down to the lumbar region. 

 Probst, Spitzer, L. Kaplan and L. Finklenburg ') proved, that the 

 ascending fibres were of vestibnlary origin and thence declared their 

 function, to be of equilibratory character. Monakow, Ferrier and 

 Turner, Lloyd Thomas, Lewandowsky, Winkler and van Gehuchten 

 added materially to our knowledge of the anatomical analysis of 

 the P. L. B. formation. Probst discovered that from Bechterews nucleus 

 most ascending fibres are homolateral and Wallenberg succeeded 

 in showing in birds, that the innermost fibres in this structure are derived 

 from the contralateral vestibnlary nuclei. Yet, the physiological analysis 

 of this region made very little progress. As to the descending tracts 

 to Darkschewitch' ) BoYCE, Redlich ") we owe details about the grey 

 masses about the posterior commissure, but no special research was 

 reported about the accurate relation of these nuclei and the descend- 

 ing fibres in the P. L. B., as far as I am aware. It may be observed 

 that only recently Cayal's accurate description of this region in the 

 chicken and Fuse's detailed account, from Monakow's laboratory, on 

 the vestibnlary nuclei, as also Horsley and Clarke's researches have 

 cleared the road for the physiological analysis. 



1) Transactions Royal Dutch Academy 1902. 



2) Philosophical Transactions 1898. Vol. 186. P. 3^5. 

 ^) Schmidt's Jalirbiichen. 1899. 



*) Academie royale de Belgique. 1895. 



») Brain. 1898. 



Ö) Monatschrift f. Psychiatrie und Neurologie. 1900. Vol. Vlll. 



7) Monatschrift f. Psych, u. Neur. 1900. \ ol. VIII. P. 210. 



^) Pflügeh. Archiv. Vol. 36. P. 639. 



'■>) Monatschrift f. Psych, u. Neurol. 1899. Vol. V. P. 119. 



