194 THE BRAIN. 



together as the cerebro-spinal centre. The sympathetic 

 ganglia will be described farther on. 



5, The Brain of an adult usually weighs about three 

 pounds. 



It has two chief parts (Fig. 52), the great brain or cere- 

 brum, A, and the small brain or cerebellum, B. It is joined 

 to the spinal cord by the medulla oblongata, D, The parts 



FIG. 52. Diagram illustrating the general relationships of the parts of the brain 

 as seen from the side. A, cerebrum ; , cerebellum ; Z>, medulla oblongata. 



of the brain are not really so widely separated as is rep- 

 resented, for the sake of clearness, in Fig. 52. They lie 

 closely packed together, as shown in Fig. 53. 



The cerebrum fills all the front and upper part of the 

 skull-cavity. It is much larger than the cerebellum, and 



5. What does the brain of a grown person usually weigh ? What 

 are its chief parts ? How joined to the spinal cord? How do they 

 lie in the skull ? Relative size ? What are the cerebral hemispheres? 

 How are their surfaces marked ? Name of the ridges ? 



