The Nervous System 223 



x 341. Importance of Reflex Action. Reflex action is a 

 marvelous provision of nature for our comfort, health, and 

 safety. Its vast influence is not realized, as its numberless 

 acts are continually going on without our knowledge. In 

 fact, the greater part of nerve power js expended to pro- 

 duce reflex action. The conscious centers are thus relieved 

 of a vast amount of work. It would be impossible for the 

 brain by serving as a " thinking center " to control every 

 act of our life. 



The fact that the gray cells of the spinal cord can origi- 

 nate a countless number of reflex and automatic actions 

 is not only of great importance in protecting the body from 

 injury, but increases vastly the range of our activities. 



Even walking, riding the bicycle, writing one's signature, 

 "playing at sight " a difficult piece of music, and number- 

 less other such acts may become reflex movements. To 

 learn how, requires, of course, the action of the brain, but 

 by frequent repetition the muscles become so accustomed 

 to certain successive movements that they are continued 

 by the cord without the action of the brain. 



We may thus acquire a sort of artificial reflex action, 

 often called "unconscious cerebration," which in time 

 becomes in a way a part of our organization and is carried 

 on without will power or even consciousness. 1 



Thus, while the hands are busily doing one thing, the 

 brain can be intently thinking of another. In fact, any 

 attempt to control reflex action is more apt to hinder than 

 to help. In coming rapidly down stairs, for instance, the 



1 There is a story, which is creditable enough, though it may not be 

 true, of a practical joker, who, seeing a discharged veteran carrying home 

 his dinner, suddenly called out " Attention ! " whereupon the man instantly 

 brought his hands down, and lost his mutton and potatoes in the gutter. 

 The drill had been thorough, and its effects had been embodied in the man's 

 nervous structure. HUXLEY'S Lessons in Elementary Physiology. 



