explanation of cut. 
a . a _Blood clot in fourth ventricle. 
b —Medulla oblongata. 
c —Fourth ventricle. 
d-d-d —Cerebrum. 
c _Fissure between cerebrum and cerebellum. 
The cerebellum was lifted away from the medulla ob- 
mgata by means of the chain hooks and as the brain is 
iewed from the posterior aspect, it shows the fourth ven- 
ricle. 
