MYCETES SENICULUS 231 



LEVEL OF THE ANTERIOR COMMISSURE (FIG. 1^8) 



At the level <>r the anterior commissure the brain stem has terminated 

 in its cephalic extremity. The upper hmit of the optic thahimus (Th) is 

 seen as it forms the anterior thalamic tubercle. The anterior commissure 

 (AC) is approaching the midline from either side, about to establish com- 

 munication between the two halves of the axis. The other important struc- 

 tures in this level are indicated by corresponding letters in the captions. 



