104 PHYSIOLOGY FOE THE LABORATORY. 



a. Pull up the outer edge of this cut and find a hollow 

 space, the lateral ventricle. 



b. Cut off its roof and look for the corpus striatum, pro- 

 jecting from the floor at the anterior end. 



c. Sketch. 



III. ANOTHER HORIZONTAL SECTION. 



Cut off another section just below the corpus callosum 

 so as to pass through the corpus striatum and the optic 

 thalamus. 



Notice : 



a. The gray matter around the margin and its relation 

 to the convolutions. What, then, is the purpose of the 

 convolutions ? 



b. The size and shape of the fissure of Sylvius and the 

 average depth of the fissures between the convolutions. 



c. Sketch. 



IV. A TRANSVERSE SECTION. 



Cut the other hemisphere transversely halfway between 

 the pons and the optic chiasma. 



Notice on the cut surface : 



a. The shape of the fissure of Sylvius. 



b. The gray matter composing the optic thalamus and 

 the corpus striatum. 



c. Sketch. 



V. THE CEREBELLUM. 



Cut the peduncles of the cerebellum and remove it. 

 Cut one half transversely at the centre and determine the 

 relative number and depth of the fissures. 



