STRUCTURE OF THE SPINAL CORD. 



217 



FIG. 250. TRANSVERSE SECTION OF MONKEY'S SPINAL CORD. (Bevan Lewis.) 1 



C n from the cervical region ; T, from the thoracic region ; L, from the lumbar region. 



A, anterior cornu ; P, posterior cornu; a, anterior column ; I, lateral column ; p, posterior 

 column ; ac, anterior commissure ; ae, ai, external and internal cell-groups of anterior 

 cornu ; a/, anterior median fissure ; ar, anterior roots ; cc, central canal ; fr, formatio 

 reticularis ; il, lateral group of cells ; vc, vesicular column of Clarke ; pc, posterior com- 

 missure ; pf, posterior median fissure ; pm, postero-mesial column ; pr, posterior roots ; 

 sg, substantia gelatinosa. 



l Taken by permission of the author from Ferrier's Functions of the Brain. Second Edition. 



