STRUCTURE OF MEDULLA OBLONGATA 541 



and gracile nuclear columns of grey matter which grow out from the basal 

 portion of the posterior column and underlie the strands of the same name, 



Funiculus gracilis 



Funiculus 

 cuneatus 



Tractus 

 spinalis of 

 fifth nerve 



Gracile nucleus 



Cuneate 

 nucleus 



Substantia 

 gelatinosa 

 Rolandi 



Decussation 

 of the lemniscus 



Medial 

 _ accessory 

 olivary nucleus 

 Fila of the 

 hypoglossal 

 nerve 



-/. Pyramid 



FIG. 227. Transverse section through the lower part of the Medulla 

 Oblongata of a full-time Foetus above the Decussation of the Pyramids, 

 treated by the Weigert-Pal method. The grey matter is white, and the 

 medullated strands of nerve fibres are black. 



Gracile nucleus 



Grey matter |j| 

 around canal 



Central canal~ 



Decussation 

 of pyramids 



Funiculus 



gracilis 



Funiculus 

 eatus 



Tractus spinalis 

 of fifth nerve 



Substantia 

 gelatinosa 

 Rolandi 



Cerebello-spinnl 

 fasciculus 



Detached head of 



p anterior column 



of grey matter 



Lateral part of anterior 

 funiculus pushed aside 

 by decussation 



Antero-median furrow 



FIG. 228. Transverse section through lower end of the Medulla Oblongata of 

 a full-time Foetus, treated by the Weigert-Pal method. The grey matter 

 is therefore bleached white ; whilst the medullated tracts are black. 



begin to make their appearance. From the deep aspect of these nuclei, 

 fibres, which take origin within them, stream antero-medially through the 



