INTERIOR SURFACE OF THE FORE-BRAIN. IOQ 



Corpus callosum. 

 Floor (edge of wedge) 



Tegmenta of mid-brain, 



Posterior perforated substance of mid-brain, 



Tuber cinereum, 



Infundibulum, 



Optic chiasma. 

 Lateral wall (beveled surface) 



Internal capsule (superior lamina), 



Caudate nucleus, 



Stria terminalis, 



Thalamus. 

 Anterior wall (border of wedge) 



Lamina terminalis, 



Anterior commissure, 



Genu of corpus callosum. 

 Posterior wall 



Posterior commissure with cerebral aqueduct beneath it, 



Corpora quadrigemina of mid-brain, 



Pineal body, 



Transverse fissure of cerebrum, containing the chorioid tela 

 of third ventricle, 



Splenium of corpus callosum. 



The fore-brain cavity thus bounded is subdivided by two 

 partitions (Figs. 29, 35 and 42). The body of the fornix, together 

 with the chorioid tela of the third ventricle and the roof epithelium 

 of the third ventricle, forms a horizontal partition which divides 

 the cavity into an upper and lower chamber. The superior 

 chamber is divided into two lateral chambers, the lateral ventricles, 

 by a double vertical partition, the septum pellucidum. The infe- 

 rior chamber is the third ventricle 



The body of the fornix (corpus fornicis, Figs. 29 and 36) is 

 a triangular sheet of fibers, whose base is attached to the under 

 surface of the splenium of the corpus callosum, and whose bifid 

 apex extends forward to the rostrum and the anterior com- 

 missure. Its lateral borders rest on the thalami, the chorioid 

 tela alone intervening (Fig. 42). And the narrow chamber between 



