HISTOLOGY OF THE CENTRAL NERVOUS SYSTEM ob' THK \VEDDELL SEAL. 143 



The postero-lateral and intermedio-lateral masses of grey matter are united by 



strands of neuroglial tissue, which break up the lateral regions of the cord into a well- 

 marked reticular formation. The grey matter in general is characterised by its deeply 

 staining neuroglia fibres, which are of a somewhat coarse nature, and are apparently 

 less in number per unit area as compared with the supporting tissue of higher types 

 of cord. 



K* 



m. 



a- 



a./. <L-k 



FIG. 1. A transverse sretion of the spinal turd (upper e.ervieal region). 



fi./t. Posterior hum "I" grey matter i. I.egtiining 

 of the sulistantia gelatinoM of Rolando). 

 i.l.h. Intermedio-lateral horn. 

 f.r. Konnatio reticularis. 

 n.h. Anterior horn. 

 p.m. Tia mater. 



a. f. Antcrinr median lisMire. 

 p.f. Posterior median HSMIIV. 

 /i.r. Pusterinr nint-linndli's. 

 a.r. Anterior root-bundles. 

 '".;/. Funiculua gracilis (posteriormedian column), 



showing mi iiidiiMlinii of the 



of tile nucleus nr.ieilis. 



In the central region of the section the posterior grey commissure is of wide extent, 

 ;ind u small amount of neuroglia is to be seen anterior to the central canal of the cord : 

 the latter is flattened antero-posteriorly, and is lined by a well-marked layer of 

 columnar ciliated epithelium. 



The postero-median fissure is of about the same length as the anterior median 

 fissure, perhaps slightly longer ; but the cord has apparently been subjected to a certain 

 amount of mechanical pressure, causing flattening, and giving the whole section the 

 appearance of abnormal transverse as compared with antero-posterior diameter. The 



(ROY. soc. EWN. TRANS., VOL. xi.vm., s.'il.) 



