THE SPINAL CORD 24! 



crossed, pyramidal tract, as distinguishing it from the other 

 descending column, (b) The crossed pyramidal tract is ex- 

 ternal to the posterior cornu of gray matter and internal to 

 the direct cerebellar tract. Its fibers decussate in the an- 

 terior pyramids of the medulla oblongata. 



II. (a) The direct cerebellar tract occupies the outer pos- 

 terior part of the lateral column. Its fibers reach the cere- 



b 



...Ji 



FIG. 75. Scheme of the conducting paths in the spinal cord at the 

 third dorsal nerve. 



The black. part is the gray matter, v, anterior, hw, posterior root; a, direct, 

 and g, crossed, pyramidal tracts; b, anterior fundamental fasciculus; c, Goll s 

 column; d, column of Burdach; e, anterior radicular zone; /, mixed lateral tract; 

 h, direct cerebellar tracts. (Landois, modified.) 



bellum through the inferior peduncles, after having trav- 

 ersed the posterior pyramids of the medulla. This tract 

 exists throughout the length of the cord, (b) The column 

 of Goll (postero-internal column) is situated posteriorly in 

 a position corresponding to the column of Turck anteriorly 

 just lateral to the posterior median fissure. Fibers in this 

 column extend from the upper lumbar region to the funi- 

 culi graciles of the medulla. 



III. (a) The anterior fundamental fasciculus lies between 



the column of Turck internally and the anterior cornu and 



anterior roots of the spinal nerves externally. Its fibers are 



lost in 'the medulla above. (b) The anterior radicular 



16 



