96 PHYSIOLOGY FOR THE LABORATORY. 



3. What is its relation to the long median fissure 



and to the fissure between the cerebrum and 

 cerebellum ? 



4. What is its use ? 



b. The pia mater is the thin inner membrane. 



1. What is on this membrane ? 



2. What is its function? 



c. The arachnoid is between the two. It is a thin mem- 

 brane just outside the pia mater, and bridges across the 

 fissures. 



III. THE GENERAL PARTS. 



Carefully remove the dura mater, but the pia mater may 

 remain on the brain to protect it. 



a. The cerebrum is the large anterior part of the brain. 

 This is the fore-brain. 



b. The cerebellum or smaller division may be seen on the 

 dorsal surface posterior to the cerebrum. Trace it around 

 toward the ventral surface. 



c. The pens Varolii is the band that extends across ven- 

 trally from one side of the cerebellum to the other. 



d. The medulla oblongata, or spinal bulb, is beneath the 

 cerebellum, posterior to the pons Varolii. Push the cere- 

 bellum gently forward to find the dorsal surface of the 

 medulla. 5, c, and d constitute the hind-brain. 



e. The crura cerebri, or peduncles of the cerebrum, are on 

 the ventral side, just anterior to the pons Varolii. 



1. Where do their netve fibres come from ? 



2. Whither do they lead? 



