THE DISSECTION OF THE BACK 



199 



in the sacral region, they are almost equal in depth and the 

 central canal occupies the centre of the medulla spinalis. 



White Matter of the Medulla Spinalis. The white matter 

 forms a thick coating on the outside of the fluted column of 

 grey matter. It is marked off into three funiculi. The 

 posterior funiculus is wedge-shaped in transverse section, and 

 lies between the postero-median septum and the posterior 

 grey column. The lateral funiculus occupies the concavity of 

 the grey crescent. Posteriorly it is bounded by the posterior 

 grey column and the postero-lateral sulcus, whilst anteriorly it 

 extends as far as the most lateral fila of the anterior nerve- 

 roots. The anterior funiculus includes the white matter 



Postero-median septum 

 Postero-lateral sulcus 



Fasciculus cerebro-_ 

 spinalis lateralis 



Fasciculus cerebro 

 spinalis anterio 



Fasciculus gracilis 

 Fasciculus cuneatus 



_ Substantia gelatinosa 

 Rolandi 



Fasciculus cerebello- 

 spinalis 



Fila of origin of 

 the accessory nerve 



Antero-median fissure 



FIG. 81. Transverse section through the upper cervical part of the Medulla 

 Spinalis of a full-time Foetus, treated by the Pal-Weigert process. 



between the antero-median fissure and the anterior column 

 of grey matter, and also the white matter which separates 

 the thick extremity of the anterior grey column from the 

 surface of the spinal medulla and is traversed by the emerging 

 fila of the anterior nerve-roots. 



In the cervical region a faint longitudinal groove runs 

 downwards on the surface of the posterior funiculus of the 

 medulla spinalis. This indicates the position of a septum 

 which passes into the funiculus from the deep surface of the 

 pia mater and divides it incompletely into two unequal strands. 

 The groove is termed the intermediate posterior sulcus. The 

 strand on its medial side is the fasciculus gracilis (Goll's), 

 whilst the lateral and larger strand receives the name of the 

 fasciculus cuneatus (Burdach's). 

 ii 13 c 



