METATHALAMUS AND HYPOTHALAMUS. 379 



system from the temporal lobe to the thalamus. Outside the ventricle, and separated 

 from this by the plexus ohorioideus, lies the tractus opticus. The pes pedunculi is 

 separated from that of the opposite side by the substantia perforata posterior. 



The two columns of the fornix are united, and form a short, thin plate already 

 in relation with the psalterium. 



