(Facing Page 157.) 



Fig. 76. THE CIRCULATION AT THE BASE OF THE BRAIN, THE CIRCLE OF WILLIS. (From 



Quain, after Allen Thomson.) 



1, left internal carotid artery; 2, left anterior cerebral artery; X, the anterior com- 

 municating artery; 3, left middle cerebral artery, passing into fissure of Sylvius, and 

 seen here running over the island of Reil, by the cutting away of the left temporal lobe; 

 4, left posterior communicating artery; 5, basilar artery; 6, left posterior cerebral artery; 

 7, 8, 9, cerebellar and vertebral arteries. 



