150 ANSWERS TO PRACTICAL QUESTIONS 



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. Soys often, though foolishly, thrust a pin into the 

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



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

 sensible. 



24. Will ten minutes 9 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 influences of the sun and pure 

 air demand that we should exercise out-of-doors. 



25. Why would an elastic tendon be unfitted to trans- 

 mit the motion of a muscle ? 



Force would be lost by its transmission through an elastic 

 medium. 



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

 he instantly fall ? 



The body is kept erect only by the constant exercise of 

 many muscles. These perform their functions through the un- 

 conscious action of the brain and spinal cord. A blow para- 

 lyzes the nervous system, the muscles at once cease to act, and 

 the body falls by its weight. 



27 What is the cause of the difference between light 

 and dark meat in a fowl ? 



The amount of blood which circulates through different 

 parts of the body. The organs of a fowl which are used the 

 most become the darkest. 



69 1. If a hair be plucked out, will another grotv in 

 its place ? 



Yes. A new hair will always grow out so long as the pa- 

 pilla at the bottom of the follicle remains uninjured. 



