378 THE BRAIN 



the fissure, it turns medially, along the stem of the fissure, and 

 ends in the cavernous sinus. If the vein is traced, its ter- 

 minal cut end will be found in the region of the anterior part 

 of the interpeduncular fossa. 



The inferior cerebral veins which do not terminate in the 

 superficial middle cerebral vein run downwards, towards the 

 infero-lateral border of the hemisphere, and they end in the 

 transverse sinus. 



In almost all cases there is a direct communication 

 between the superior sagittal sinus and the posterior part of 

 the superficial middle cerebral vein, by means of a vein which 

 is called the great or superior anastomotic vein ; and, very 

 frequently, the posterior part of the superficial middle 

 cerebral vein communicates with the transverse sinus, through 

 one of the inferior cerebral veins which opens into both, and 

 which is called the inferior or small anastomotic vein. Both 

 the communications may become of importance in cases in 

 which the posterior part of the superior sagittal sinus or the 

 commencements of both transverse sinuses are obstructed. 



The majority of the veins on the medial surface of the 

 hemisphere terminate in the anterior cerebral vein, which 

 runs along the upper surface of the corpus callosum, but some 

 end in the inferior sagittal sinus, and some ascend to the 

 superior sagittal sinus. 



The veins from the anterior part of the inferior surface of 

 the hemisphere join either the superficial middle cerebral vein 

 or the anterior cerebral vein ; those from the posterior part 

 of the inferior surface pass to the basal vein, to the superior 

 petrosal sinus, to the straight sinus, and to the transverse 

 sinus. The veins from the interior of the hemispheres 

 which join the great cerebral vein will be described later 

 (see p. 444). 



Veins of the Mid-Brain. There are no large veins from 

 the mid-brain, and the small veins which return the blood 

 from that part of the brain end either in the great cerebral 

 vein, or in the basal veins, or in both. 



Veins of the Cerebellum. The veins on the superior 

 surface of the cerebellum pass forwards ; some terminate in 

 the great cerebral vein, others in the superior petrosal 

 sinuses. Some of the veins of the inferior aspect of the 

 cerebellum end in the straight sinus, others in the transverse 

 sinus, the occipital sinus, or an inferior petrosal sinus. 



