474 THE POPULAR SCIENCE MONTHLY. 



is fitted with other nmscles to roll it in the socket and to direct it 

 on objects which the will commands it to see. Then, too, there is 

 the sense of touch, which, with sight, gives us knowledge of the 

 outside world. How could it give us such complete information 

 of our environment were it not supplemented by the muscles of 

 the outstretched arm and the feeling hand ? Our hearing is bet- 

 ter because we have muscles to enable us to turn the head that 

 we may listen. Smell and taste are more efficient because they 

 are supplemented by muscles appropriate to their functions. 



Then, if we take our social life, how large a part of it is de- 

 pendent on speech ! And speech itself would be impossible with- 

 out the muscular power of taking and expelling breath and the 

 movement of the muscles of the larynx. Without muscles the 

 hand of the writer could not produce our books any more than 

 the cunning hand of the artificer could work out the inventions 

 of this inventive age. Knowledge itself, then, is dependent on 

 muscles and the power of muscles on motion. 



It is, therefore, a wise provision of Nature which implants in 

 children a desire for play. By their very instincts they seek 

 motion, and the exercise and growth of their bodies through 

 motion. 



But does the good effect of exercise end in the body ? Is that 

 simply larger and stronger ? The mind, too, has its share of 

 good. In the first place, the brain and nervous system are sup- 

 plied with blood and more of it. The repair of the waste is more 

 completely made. This of itself is one great gain. But in all 

 use of the voluntary muscles there is, as the term implies, a 

 necessary putting forth of will. The mind is exercised while the 

 body works. And this is especially true in all exercises which 

 require skill, in which the mind has an object to gain through 

 the skillful use of the body. This mental element comes in very 

 early in a child's life as, for instance, in learning to walk, to 

 swim, or to write. All through the years of childhood it accom- 

 panies motions in games, most mind being required in those 

 games which require most skill. So those gymnastic exercises 

 which call for combinations of muscles in action, and need quick- 

 ness and exactness, are more useful for the majority of children 

 and men than those requiring the use of strength alone. For, 

 to attain success in games or exercises of skill, not only quickness 

 of body is needed, but an alertness of mind, and often, too, quick- 

 ness of the senses of sight and hearing. This mental element in 

 certain athletic games explains, in a measure, their fascination. 

 They furnish an exercise not for the body alone, but for the 

 whole man every part of his being, including his mind, his 

 social nature, and even his moral nature, coming into play. This 

 is particularly the case in games in which a number of players 



