404 THE NERVOUS SYSTEM AND ORGANS OF SENSE 



function, no will power is exerted, nor are intelligent acts 

 performed. All acts performed in such a state are known as 

 reflex actions. An example of a reflex may be obtained by cross- 

 ing the legs and hitting the knee a sharp blow. The leg, below 

 the knee, will fly up as a result of reflex stimulation. The 

 involuntary brushing of a fly from the face, or the attempt to 

 move away from the source of annoyance when tickled with a 

 feather, are other examples. In a reflex act, a person does not 

 think before acting. The nervous impulse comes from the out- 

 side to cells that are not in the cerebrum. The message is short- 

 circuited back to the surface by motor nerves, without ever having 

 reached the thinking centers. The nerve cells which take charge 

 of such acts are located in the cerebellum or spinal cord. 



Automatic Acts. — Some acts, however, are learned by conscious 

 thought, as writing, walking, running, or swimming. Later in 

 life, however, these activities become automatic. The actual 

 performance of the action is then taken up by the cerebellum, 

 medulla, and spinal ganglia. Thus the thinking portion of the 

 brain is relieved of part of its work. 



Habit Formation. — The training of the different areas in the 

 cerebrum to do their work well is the object of education. When 

 we learned to write, we exerted conscious effort in order to make 

 the letters. Now the act of forming the letters is done without 

 thought. By training, the act has become automatic. In the 

 beginning, a process may take much thought and many trials 

 before we are able to complete it. After a httle practice, the same 

 process may become almost automatic. We have formed a habit. 

 Habits are really acquired reflex actions. They are the result of 

 nature's method of training. The conscious part of the brain has 

 trained the cerebellum or spinal cord to do certain things that, at 

 first, were taken charge of by the cerebrum. 



Importance of forming Right Habits. — Among the habits early 

 to be acquired are the habits of studying properly, of concentrat- 

 ing the mind, of learning self-control, and above all, of content- 

 ment. Get the most out of the world about you. Remember 

 that the immediate effect in the study of some subjects in school 

 may not be great, but the cultivation of correct methods of think- 

 ing may be of the greatest importance later in life. 



