IN HUMAN PH T8IOL OGY. 189 



34. In what consists the value of the power of habit ? 



It saves the " wear and tear " of our principles. We 

 can perform an act a few times, though with difficulty, 

 and then ever after it becomes a habit. We resist evil 

 once, and thenceforth it is easier. We can become 

 accustomed to do good, so that the chances will all be 

 in favor of our well-being in any emergency. By as much 

 ' as the power of habit is thus pregnant with good, by so 

 much is it susceptible of terrible evil. 



35. How many pairs of nerves supply the eye ? 



(See Physiology^ page 167.) 



Three ; the motores oculi. 



36. Describe the reflex actions in reading aloud. 



The body is kept erect, the hand holds the book, the 

 eyes are directed to the page, the vocal organs pronounce 

 the words, the features express the sentiments, and the 

 other hand makes corresponding gestures yet all the 

 time the mind is intent only upon the thought conveyed. 



37. Under what circumstances does paralysis occur'} 



When the nerve leading to any part of the body is 

 injured or fails to keep up communications between that 

 portion and the mind. 



38. If the eyelids of a profound sleeper were raised, and a 

 candle bt ought near, would the iris contract 1 } 



It would, by reflex action. 



