THE CEREBELLUM. 521 



transverse section of the internal column of the cms cerebelli, 

 cannot as yet be decided. Speaking broadly, we do not know 

 whether all the fasciculi of the internal column of the crus 

 cerebelli represent portions of the auditory tract, or not. The 

 decussation between the roof nuclei necessitates a re-decussa- 

 tion (?) under all circumstances, because the transverse sections 

 of the internal division of the crus cerebelli run below into 

 the fibrse arcuatse. 



The view expressed by Kolliker and Deiters, that the cere- 

 bellum, regarded as a whole, must represent a loop or sling, 

 the curves and sinuosities of which establish very indirect 

 connections between the cerebrum and the nerve-roots, is 

 scarcely supported more strongly by any other fact than by 

 this, viz., that the auditory nerve, which is so intimately con- 

 nected with the functional activity of the lobes of the cere- 

 brum, is in all probability, by its immediate connections entirely 

 lost in the cerebellum. 



The relations probably existing between the cerebellum 

 and the muscular sense postulate the looping of other tracts 

 running in the cerebellum towards the cerebrum. In truth, 

 it can only represent an important station for the conduction 

 of these impressions, because its predominant position in regard 

 to consciousness, as in other sensorial regions, in accordance 

 with Wundt's happy expression, also conditions the signals of 

 these sensations reaching the cerebrum. Any attempt to illu- 

 minate the chaos of possible combinations of the outrunners of 

 the cerebellum in their course through its grey substance would 

 at present embrace more suppositions than matters of fact, 

 and therefore cannot be entered upon in an account properly 

 based on morphology. In a morphological point of view, we 

 can only refer to two theories of the mode of looping, supported 

 by facts. One of them lies in the actual looping, observed by 

 Obersteiner and Hadlich, of the ramifications of the processes 

 of the large nerve cells of Purkinje ; the second is founded on 

 the very peculiar form of these nerve cells. 



The nerve cells of Purkinje are namely, in a morphological 

 sense, bipolar. Their internal and external extremities are the 

 rudiments of two different types of nerve corpuscles. If we 

 could divide a nerve corpuscle of Purkinje into two halves. 



