THE SPINAL CORD 



669 



synapses with the posterior horn cells. Possibly they are connected 

 also with the sympathetic system. 



The Comma Tract (Descending) intermingles with the tracts of 

 the postero -median and postero-lateral columns. It consists of the 

 descending processes of the afferent fibres of posterior root ganglion 

 cells, which branch when they reach the spinal cord. Possibty some 

 fibres of this tract arise in the spinal cord itself. 



Pre-central 



gyrus 



Direct 



cerebellar tract 



- Pyramidal tract 



Pre-pyramidal 

 (rubro-spinal) 



Deiters" 



spinal tract 

 (vestibulo-spinaf) 



Anterior horn cell 



397. DIAGRAM TO ILLUSTRATE THE VARIOUS PATHS OF TRANSMISSION FROM 

 BRAIN TO SPINAL MOTOR NEURONS. (Mott.) 



Tracts which pass from the Cord to the Brain (Lateral Columns 

 The Dorsal Spino-Cerebellar (the direct or posterior cerebellar tract 

 of Flechsig). The large fibres of this tract are derived from cells in 

 Clarke's column of the same side, and pass in a postero-lateral marginal 

 position (5, Fig. 395) into the spinal bulb, and thence by the 

 restif rm body to the anterior portion of the superior vermis of the 

 cerebellum. 



The Ventral Spino-Cerebellar Tract (or ascending ant ero- lateral or 

 ventral cerebellar tract of Gowers) arises on the opposite side from 



