944 



THE XER VE SYSTEM 



campus, and their course will be traced from this source to the ending in the corpus- 

 albicans. Beginning at first as a stratum of white substance (alveus) consti- 

 tuting the ectal surface of the ventricular bulge of the hippocampus, the fibres 



FRENULUM 

 GIACOMINI 



HIPPOCAMPAL 

 COMMISSURE: 



FASCIOLA 



CINEREA 



Firs. G97. The fornix, hippoeampal commissure, splenium, and dentate gyre seen from tlie basal aspect. 



become collected along its medial border in a narrow but distinct folded band, 

 the fimbria. This increases in diameter as increments are added to it along 

 its course, until, at the apical region of the trigonurn ventriculi, it leaves the 

 dwindling hippocampus to ascend in a curved course (dorsimesad) toward the 



ANT. PILi_AH 

 OF FORNIX 



HIPPOCAMPUS 



FIG. 698. Diagram of the fornix. 



subsplenial callosal surface as a thick, flattened band. Once free from the hippo- 

 campus on each side, the two converging bands of opposite sides are called the 

 posterior pillars or crura fornicis. The majority of the fibres continue frontad 



