THE NERVOUS SYSTEM 



125 



FIG. 114. -- THE LOBES OF THE RIGHT 

 SIDE OF BRAIN and their functions. 

 (Jegi.) 



The speech center is true only for left-handed 

 persons. Medulla is marked " Bulb." 



ments ; that is, it makes the 



muscles act at the right 



time and with due force in 



complex acts, such as stand- 

 ing, walking, talking. A 



man could strike just as 



hard without the action of 



the cerebellum, but he would 



not be likely to hit what he 



aimed at. A drunken 



man staggers and fails to 



control the muscles in walk- 

 ing because the alcohol has 



caused the blood to collect 



and congest around the 



cerebellum and press upon 



it. One whose cerebellum 



has been injured by accident staggers like a drunken man. 



Coverings of 

 the Brain. Lin- 

 ing the skull and 

 covering the cere- 

 brum are found 

 two membranes 

 which inclose a 

 lymph-like fluid. 

 Thus a kind of 

 water bedis made 

 which surrounds 

 the soft and deli- 

 cate cerebrum 



FIG. 115. MOTOR AND SENSORY AREAS OF LEFT 



HEMISPHERE. Speech- center marked "Lips." anc * protects it 



In what region are the motor centers? The sensory centers? from jaTS. A 



