582 



NERVOUS SYSTEM. 



of the cells, the others probably passing upward to be connected with cells in the 

 encephalon. 



Tracing the prolongations from the cells, we find that one or more of the poles branch 

 and subdivide in the gray substance and give origin to fibres, but that these fibres do 

 not branch after they pass into the white substance. Other poles connect the nerve-cells 

 with each other by commissural fibres of greater or less length ; but it has never been 

 positively demonstrated that the cells are thus connected into separate and distinct 

 groups, although this is possible. 



The accompanying figure, taken from the excellent monograph on the lumbar enlarge- 



FIG. 186. Group of cells connected with the anterior roots, as seen in a transverse section, from the anterior 



cornu of the sheep. (Dean.) 



A, entrance of the anterior roots into tlie cornu; &, 6, &, &, cells connected by long, slender processes with the ante- 

 rior roots. In this figure, almost every variety of cell-connection may be seen, with bundles of fibres crossing 

 in every direction. 



