STRUCTURE OF THE SPINAL CORD 



317 



distinct groups. In the anterior horn we may distinguish three groups, a 

 median group of cells near the middle line, majiy of which send their processes 

 across to the other side in the anterior white commissure, and an external 



CERVICAL. 



DORSAL. 



LUMBAR. 



ANTERIOR 

 ROOT-BUNDLES 



FIG. 154. Sections of human spinal cord from the lower cervical, mid-dorsal, and 



mid-lumbar regions, showing the principal groups of nerve cells, and on the 



right side of each section the conducting tracts as they occur in the several 



regions (magnified about 7 diameters). (E. A. SCHAFER.) 



a, b, c, groups of cells of the anterior horn ; d, cells of the lateral horn ; e, middle 



group of cells ; /, cells of Clarke's column ; g, cells of posterior horn ; cc, central 



canal ; ac, anterior commissure. 



