FUNCTION OF CEREBELLUM. 26*3 



is likely that in time we shall know much more on this 

 subject. 



The accompanying diagram shows some of these centers. 



The Functions of the Cerebellum. - The cerebellum is 

 the center for regulating the actions of the skeletal muscles. 

 When we walk or run, or even stand still, a number of mus- 

 cles must act, and act in concert. The nerve impulses origi- 

 nate in the cerebrum; but the cerebellum is the center for 

 harmonizing the action of these various muscles, or Coordi- 

 nating them. When the cerebellum has been removed from 

 a pigeon the bird nutters, and, while possessing the power to 

 move, does not seem capable of any regular and orderly 

 movement. There is no loss of intelligence, no paralysis. 

 Of course, in this experiment there is great disturbance of 

 the system, and perhaps too much is inferred from it. 



The Spinal Bulb. The Spinal Bulb (medulla oblongata) 

 is the connection between the spinal cord and the brain. The 

 bulb may be said to be that part of the spinal cord which is 

 within the cranium. It is enlarged, hence its name, Spinal 

 Bulb. From it arise all the cranial nerves except the first 

 five pairs. The spinal bulb is also the center for the control 

 of many processes. It is the center for the control of respi- 

 ration, of circulation, of deglutition, and perhaps for many 

 other processes. 



Blood Supply of the Brain. Brain Work and Brain 

 Rest. During the period when the brain is more active, it 

 receives a larger supply of blood. During sleep it is paler. 

 Sleep is not merely rest for the body ; it should be complete 

 rest for the brain. In so far as there are dreams, it would 

 seem to indicate a partial activity ; that is, incomplete rest. 

 The brain-worker especially needs plenty of sleep ; excellent 

 authorities say at least eight or nine hours. The brain, like 

 the muscles, needs exercise ; and it also needs regular periods 



