286 



NORMAL HISTOLOGY. 



The anterior column includes two tracts : the direct pyram- 

 idal tract (Tiirck's column), next the median fissure, and the 



FIG. 319. 



Diagram showing principal divisions of white matter of spinal cord : A, P, anterior and 

 posterior horns of gray matter ; DP, direct pyramidal tract ; GB, anterior ground-bundle ; 

 Cf, crossed pyramidal tract; DC, direct cerebellar bundle; GT, Gowers's or ascending 

 antero-lateral tract ; DA L, descending antero-lateral patch ; ML, mixed lateral tract ; 

 BG, column of Burdach (fasciculus graciiis) and column of Goll (fasciculus cuneatus). 



anterior ground-bundle, or anterior radicular zone, which is 

 continuous with the adjoining area of the lateral region. 



The lateral column contains a number of secondary tracts, two 

 of which are especially prominent, the crossed pyramidal and the 

 direct cerebellar. The latter lies as a narrow zone at the margin 

 of the cord, and extends from the posterior root about half-way to 

 the anterior root. The crossed pyramidal tract appears as an 

 oval area which lies next the cerebellar path and in front of the pos- 

 terior root. The remainder of the lateral column is occupied by a 

 number of smaller tracts, concerning which uncertainty still exists. 

 These may be grouped into three segments : an outer peripheral, 

 the ascending antero-lateral tract, or tract of Gowers, a 

 middle area, the descending antero-lateral tract, and an inner 

 zone, next the gray matter, the mixed lateral tract, of which the 

 posterior division contains probably sensory fibres and the anterior 

 motor. 



The posterior column is divided by a fibrous septum into the 

 inner triangular segment, the column of Goll, next the median 

 septum, and an outer area, the postero-lateral tract, or Burdach's 

 column, lying between Coil's tract and the posterior horn and root. 

 Since the development of the tracts above enumerated differs in the 



