212 A MANUAL OF ANATOMY. 



the body, by the posterior part of the septum lucidum and 

 the fornix ; of the posterior horn, by the hippocampus 

 minor and the bulb of the posterior horn. 



The hippocampus minor is an elevation along the inner 

 wall of the posterior horn, formed by the involution of the 

 brain corresponding to the calcarine fissure. 



The bulb of the posterior horn is a bulging in the pos- 

 terior horn above and parallel with the hippocampus minor 

 produced by the bundle of fibres the forceps major which 

 is proceeding from the splenium of the corpus callosum to 

 the occipital lobe. The floor of the anterior horn and 

 body of the ventricle present from before backward the 

 caudate nucleus (the intraventricular portion of the corpus 

 striatum), the taenia semicircularis, the optic thalamus, 

 choroid plexus, and posterior pillar of the fornix. 



The floor of the posterior horn is a flat surface behind 

 but becomes gradually elevated as the floor passes into the 

 descending horn ; this raise is the eminentia collateral, and is 

 produced by the upheaval of the brain over the collateral 

 fissure. 



The middle or descending horn of the lateral ventricle : 

 The course of this extension of the cavity of the lateral 

 ventricle is backward, outward, and downward, then forward, 

 downward, and inward to the anterior extremity of the 

 temporal lobe. 



The roof of the horn is formed by that portion of the 

 body of the corpus callosum passing to the temporal lobe 

 and is called the tapetum, also by the tail of the caudate 

 nucleus and the taenia semicircularis. At the extreme 

 anterior portion the roof is formed by the amygdaloid 

 nucleus in which the tail of the caudate nucleus and the 

 taenia semicircularis terminate. Figs. 36, 37. 



The inner wall presents a long, rounded eminence the 



