XXIX.] SPIXAL CORD. 303 



t. On either side of this, the anterior and pos- 

 terior grey commissures of deeply stained 

 substances in which crossing nerve fibres are 

 seen. 



k. The anterior white commissure consisting 

 of fairly large decussating nerve fibres in 

 front of the anterior grey commissure. 



I A round or oval deeply stained area, the 

 substantia gelatinosa, forming the hinder 

 part of the posterior cornu. 



2. Examine the same section first under a low and 

 then under a high power. Observe 



a. The large multi polar nerve cells of the an- 

 terior cornu placed chiefly in the anterior 

 and lateral part of the cornu ; they may be 

 more or less distinctly arranged in two or in 

 three groups. 



I. The transverse fibres (longitudinal in the 

 plane of the section) running from the 

 posterior part of the anterior cornu into 

 the lateral column. 



c. The fibres of the posterior root running 

 (a) transversely through the substantia gela- 

 tinosa, (yS) obliquely into the posterior 

 column. 



d. Transverse and oblique fibres running from 

 the posterior column into the posterior 

 cornu. 



