132 ELEMENTS OF HISTOLOGY. [Chap. xvi. 



which pass in a vertical and radiating direction into 

 the white matter of the columns, and they are thus 

 subdivided into a number of smaller portions ; one 

 such big septum is sometimes found corresponding to 

 the middle of the circumference of one half of the 

 cord. This is the median lateral fissure, and the 

 lateral column is subdivided by it into an anterior 

 and posterior division. 



Similarly, the anterior and posterior columns 

 may be subdivided into a median and lateral division 

 (Fig. 83). 



170. Some of these various subdivisions bear 

 definite names (Turk, Charcot, Flechsig) : 



(a) The median division of the anterior column is 

 called the direct or uncrossed pyramidal fasciculus, 

 being a ^continuation of that part of the anterior 

 pyramidal tract of the medulla oblongata (see below) 

 that does not decussate. 



(b) The anterior division of the lateral column is 

 called the anterior radicular zone. 



(c) The direct cerebellar fasciculus corresponds to 

 the peripheral portion of the postero-lateral column ; 

 it is a direct continuation of the white matter of the 

 cerebellum. 



(d) The posterior division of the lateral column 

 inside the cerebellar fasciculus is called the fasciculus 

 of Turk, or the crossed portion of the pyramidal fasci- 

 culus, it being a continuation of the decussated part of 

 the anterior pyramidal tract of the medulla oblongata. 



(e) The lateral division of the posterior column, 

 with the exception of a small peripheral zone, is the 

 cuneiform or cuneate fasciculus, or posterior radicular 

 zone. 



(/) The median division of the posterior column is 

 called the fasciculus of Goll. 



This part is connected directly with the median 

 bundle of the posterior nerve roots. (See below.) 



