ScHAPER, Structure of SclacJdan Cerebelluin. 1/ 



and usually in great numbers so that often a dense forest of 

 them comes into view. Figure 21 (plate IV) furnishes us an 

 illustration of this. It shows us a closely packed multitude of 

 fibers proceeding from the conical cell bodies on the membrana 

 limitans interna and ascending in a very irregular zig-zag course in 

 the granular layer. They are beset with numerous richly branch- 

 ing lateral branches which are closely interwoven with neighbor- 

 ing twigs and thus form an extremely delicate and complicated 

 supportmg framework, in whose meshes are found lying the ner- 

 vous elements of the granular layer. At their free ends also 

 the fibers break up in a similar manner into dcHcate terminal ar- 

 borizations. It is striking that the fibers, where they encounter 

 a blood vessel, frequently are closely united to the wall of the 

 same, as illustrated in the upper left corner of figure 21. It 

 thus appears that these fibers here enter into similar intimate 

 relations with the blood vessels as has already been often de- 

 scribed regarding the processes of the "astrocytes" in other 

 vertebrates. 



Where the granular layer is absent in the cerebellar plate, the 

 ependyma fibers have a somewhat different appearance. They 

 proceed usually more directly, have a smoother surface and give 

 off only scattered branches during their passage through the 

 zone of fibers. Such a fiber is shown in figure 22 (plate IV). 

 Towards the layer of Purkinje cells we see it break up into sev- 

 eral .slender terminal branches which are distributed between 

 the bodies of the Purkinje cells and usually end with a knob or 

 brush-like enlargement in the vicinity of the molecular layer. 



Besides the supporting fibers hitherto described of an un- 

 doubtedly ependymal origin, we find a second very characteristic 

 kind of neurogha elements (fig. 23, plate IV), which are confined 

 exclusively to the molecular layer and in my opinion are to be 

 regarded as the homologues of Bergmann's fibers in the mole- 

 cular layer of the cerebellum of higher vertebrates. These 

 fibers arise from irregular pear-shaped cell bodies lying between 

 the Purkinje cells and extend in a tolerably direct course to the 

 surface where they are placed against the limitans externa with 

 conical enlargements. They are invested along their whole 



