246 



THE NERVOUS SYSTEM 



through the gray matter in most part. The fibers decussate 

 at no particular point, but throughout the length of the cord. 

 However, some fibers bearing sensory impressions pass to 

 the column of Goll and thus upward, while some also go to 



FIG. 78. Transverse section through half the spinal cord, showing 



the ganglia. 



A, anterior cornuaJ cells; B, axis-cylinder process of one of these going to 

 posterior root; C, anterior (motor) root; D, posterior (sensory) root; E, spinal 

 ganglion on 'posterior root; F, sympathetic ganglion; G, ramus communicans; 

 H, posterior branch of spinal nerve; /, anterior branch of spinal nerve; a, long 

 collaterals from posterior root fibers reaching to anterior horn; b, short collater- 

 als passing to Clarke's column; c, cell in Clarke's column sending an axis-cylin- 

 der process (d) to the direct cerebellar tract; e, fiber of the anterior root; f, 

 axis cylinder from sympathetic ganglion cell, dividing into two branches, one 

 to the periphery, the other toward the cord; g, fiber of the anterior root termi- 

 nating by an arborization in the sympathetic ganglion; h, sympathetic fiber pass- 

 ing to periphery. (Kirkes after Romany Cajal.) 



the encephalon by the direct cerebellar fasciculi and the col- 

 umns of Burdach. Experimentally, decussation of sensory 

 fibers is demonstrated (i) by longitudinal section of the 

 spinal cord in the median line, which is followed by anes- 



