THE CEREBELLUM OF AMBLYSTOMA 



277 



The tr actus spinocerebellaris dorsalis offers considerable diffi- 

 culty in identification. As seen in Weigert preparations (figs. 

 17 to 21, tr.sp.cb.d.), a bundle of myelinated fibers emerges from 

 the cerebellar commissure near the ventrolateral extremity of the 

 latter and assumes an independent course vent-rally and cauclally. 



.nE 





•HIK 



1 — trspcbd + 

 ■trva. 



spcb v 



21 



Figs. 17 to 21 Five transverse sections through medulla oblongata and cere- 

 bellum of Amblystoma tigrinum, arranged in series from the' level of the super- 

 ficial origin of the V nerve to the level of the superficial origin of the IV nerve, 

 showing the arrangement of the fiber tracts of the cerebellum and some of the 

 tracts of the medulla oblongata for orientation. Series IIC, sects. 574 (fig. 21), 

 5S5 (fig. 20), 595 (fig. 19), 603 (fig. 18), and 605 (fig. 17). Weigert method. X 28. 



THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL 31 NO. 4 



