THE BRAIN AND ITS MEMBRANES. 



765 



of the hippoeampal convolution. Its outer edge is free, and lies on the surface 

 of the hippocampus. This edge is directed toward the cavity of the descending 

 cornu. 



The eminentia collateralis (Fig. 453). or pes accessorius, is a white eminence, 

 varvino- in size, placed between the hippocampus major and the outer wall of the 

 cornu. It is formed by the protrusion inward of the collateral fissure. 



Fascia Dentata (Figs. 453, 454. 456). On separating the inner border of the 

 corpus fimbriatum from the choroid plexus, and raising the edge of the former, a 



Genu of corp. call. 



Sept. luc. 



Foramen of Jfonro 

 Corp. striatum. 



Posterior cornu 



FIG. 457. The lateral ventricles from above, showing choroid plexuses; the left is in its natural position : 

 the right plexus is somewhat laterally displaced to show the edge of the fornix. (Henle.) 



serrated band of gray substance, the edge of the gray substance in the dentate or 

 hippoeampal fissure, will be seen beneath it: this is the fascia dentata. Correctly 

 speaking, it is not placed within the cavity of the descending cornu. The fascia 

 Itntata has a curved direction, following the course of the hippocampus, and also 

 runs obliquely from above downward and forward. Its lower extremity is lost 

 in the gray matter of the uncus or hook of the hippoeampal gyrus, where it is 

 >feii as a small band (Giacomini) passing transversely over the hook. Its upper 

 extremity is well marked (fasciola cinerea], and lies immediately behind and below 

 the splenium of the corpus callosum, over and above which it is continuous with 

 the lateral and mesial longitudinal striae of that body (Fig. 455). 



