380 



ANATOMY OF THE CENTEAL NEEVOUS STSTEM. 



In the period of development represented in Fig. 234 only the medul- 

 lated fibers of the cord are shown. It accordingly shows well the position 

 and extent of this part of the inferior cerebellar peduncle. Fig. 241 also 

 shows the different kinds of arciform fibers. 



In the corpus restiforme, however, besides the fibers from the cord, is 

 a second and much larger tract, which, since it is medullated much later 

 than the former, mu.st be diflierentiated from it. There are fibers to the oppo- 

 site olivary body. Since they come from the cerebellum, and cannot be 

 traced farther than the olive, they may be known as the tractus cerebello- 

 olivares of the restiform body. By their addition the inferior cerebellar 

 peduncle has now become of considerable size. 



The olive, nucleus olivaris inferior, .is a hollow formation of the form 



vi*^ 



°yri«i-»«if 



Fig. 241. — Origin of the spinal portion of the corpus restiforme. The fibers 

 end mainly or entirely in the vermis. Rinter strange, Posterior columns. Klein. 

 S. B., Lateral cerebellar tract. 



of a rather pointed egg whose surface is greatly corrugated. Toward the 

 median line it has a long, broad opening — hilum nuclei olivaris. "With the 

 much folded cross-section one is already familiar. When fresh, the olive 

 has a gray, transparent color, because it consists principally of a thick mass 

 of neuroglia, in which are imbedded much-branched ganglion-cells. These 

 cells send out a long axial process (Vincenei), and arou.nd them arborize the 

 terminations of another fiber-system, from the cells of Purkinje (KoUiker). 



Where the axis-cylinders of the olivary cells go is not yet known. 

 Kolliker thinks they have relations to the lateral columns of the cord. 



The tractus cerebello-olivares are large bundles of fibers, which leave 

 the ventral edge of the restiform body, extend in graceful curves downward 



