THE COD. 129 



203. The aqueduct of Sylvius (aq.s) a median pas- 

 sage continuous behind with the fourth ventricle and covered 

 by the fornix of Gottsche ; it is best made out by passing 

 a guarded bristle forwards from the fourth ventricle and 

 then removing the fornix of Gottsche ; it is in free com- 

 munication with the optic ventricle. The anterior end of 

 the aqueduct of Sylvius is all that represents the third 

 ventricle (v. 3). 



XXXIX. Make a longitudinal vertical section of 

 another brain, and observe 



204. The relations of the parts already seen, particularly 

 those of the fourth ventricle, aqueduct of Sylvius, and optic 

 ventricle. 



205. The downward continuation of the rudimentary third 

 ventricle in front of the anterior truncated termination of the 

 crura cerebri ; in this way the infundibulum (tn) is formed ; 

 it extends backwards and downwards between the lobi in- 

 teriores, and to its anterior and inferior wall the pituitary 

 body is attached. 



