THE CEREBELLUM OF AMBLYSTOMA 269 



The axones of the Purkinje cells (figs. 9, 11, and 14) have their 

 origin either from the cell body or, more commonly, from one 

 of the primary dendrites close the the perikaryon. They pass 

 into the molecular layer where they become lost among the num- 

 erous fibers there present. From many of the cells axone-like 

 processes pass into the granular layer, but turn upward to enter 

 the molecular zone, in the majority of cases observed. A similar 

 passing of the axone of the Purkinje cells into the molecular layer 

 was found by Johnston ('01) in Acipenser. 



Other cells of somewhat smaller size were observed in Golgi 

 preparations along the posteroventral border of the cerebellum 

 and at various levels within the granular layer (figs. 8, 10, 12, 

 and 13, r.P.c). Typically the cell body is elongated, giving a 

 pear-like form to the cell, but some of fusiform outline were ob- 

 served. The dendrites extend toward the molecular layer and 

 appear to terminate for the most part within the more posterior 

 and ventral region of this zone, although many do not reach the 

 molecular layer, but end within the granular layer. Some of the 

 processes are studded with gemmule-like projections (figs. 12 

 and 13). 



From the position of most of the cells of this type, along the 

 border of the cerebellum, they might be considered as ependymal 

 cells, related to the peculiarly elongated type characteristic of 

 the cerebellum of other vertebrates. In their morphological 

 characteristics, however, they resemble nerve cells. The den- 

 dritic branches do not have the arrangement or appearance of 

 the long processes of the ependymal cells. In connection with 

 many, an axone-like process was observed. This is of simple 

 type, without profuse branching near the cell body, and extends 

 into the molecular layer. In some respects these cells resemble 



Fig. 9 Horizontal section through cerebellum of Amblystoma tigrinum, show- 

 ing Purkinje cell and granule cells. Series CCIV, si. 3, sect. 84. Golgi method. 

 X 196. 



Fig. 10 Sagittal section through cerebellum of Amblystoma tigrinum. Series 

 CCV, si. 1, sect. 39. Golgi method. X 125. 



Fig. 11 Sagittal section through cerebellum of Amblystoma tigrinum. Series 

 CCV, si. 1, sect. 30. Golgi method. X 125. 



