FUNCTIONS OF THE SPINAL CORD 247 



reached. Some afferent fibers are probably not continued 

 upward to the brain either directly or indirectly. 



It thus appears that we have no very accurate knowledge of 

 the sensory paths in the cord. The gray matter seems princi- 

 pally concerned; but the columns of Goll and Burdach and 

 the direct cerebellar fasciculi also convey afferent impressions. 



The columns of Burdach have been said to present no degen- 

 eration secondary to section. Trophic centers for their fibers 

 must, therefore, exist above and below any given point of section. 

 It is found that the fibers constituting these columns pass in and 

 out along the cord between cells in different planes and acting 

 as longitudinal commissural fibers. In locomotor ataxia the 

 characteristic symptom is inability to coordinate the muscular 

 movements especially of the lower extremities; the characteristic 

 lesion has been found to be in the columns of Burdach. 

 This is of importance in determining the function of these col- 

 umns, and, in fact, leads to the conclusion that their fibers assist 

 in regulating and coordinating the voluntary movements. This 

 opinion is further supported by the connection of these fibers with 

 the cerebellum, which contains the center for muscular coordina- 

 tion if such a center exist. The sense of pressure and the so- 

 called muscular sense are probably connected with the fibers of 

 this column, and these may be the only sensory impressions 

 conveyed through the columns of Burdach. 



The anterior fundamental fasciculi, the anterior radicular 

 zones, and the mixed lateral paths degenerate in neither 

 direction after section, their trophic cells existing at both extremi- 

 ties. They connect cells in the gray matter of the cord. 



Functions of the Spinal Cord. These are (i) conductions, 

 (2) transference, (3) reflex action, (4) augmentation, (5) co- 

 ordination, (6) inhibition of reflex acts, (7) special centers (Collin 

 and Rockwell, modified). 



i. Conduction. This has been referred to in discussing the 



