IN HUMAN PHYSIOL OGY. IS 1 



21. Why can so few persons move -their ears by if he 

 muscles ? 



Perhaps, because of lack of practice ; more probably, 

 however, the muscles (see Physiology, p. 65 and Fig. 14) 

 are developed in few persons. 



22. Is the blacksmith's right arm healthier than the left? 



By no means. Strength is not essential to health. 

 The right arm may be stronger, but the functions of the 

 left may be as active and well-performed. 



23. Boys often, though foolishly, thrust a pin into the 

 flesh just above the knee. Why is it not painful 1 



The muscles of the leg there end in tendons, which are 

 insensible. 



24. Will ten minutes practice in a gymnasium answer for 

 a day's exercise ? . 



Spasmodic or violent exercise is not beneficial. It 

 should be comparatively quiet, gentle, and continuous to 

 produce the best effect. Moreover, the vitalizing influ- 

 ences of the sun and pure air demand that we should 

 exercise out-of-doors. 



25. Why would an elastic tendon be unfitted to transmit 

 the motion of a muscle ? 



Force would be lost by its transmission through an 

 elastic medium. 



26. When one is struck violently on the head, why does 

 he instantly fall ? 



The body is kept erect only by the constant exercise 



