THE MUSCULAR SYSTEM 259 



not be excessive or carried to the point of exhaustion. 

 Severe physical exercise is destructive to both muscular 

 and nervous tissues. 2. It should, if possible, be of an 

 interesting nature and taken in the open air. 3. It should 

 be counter-active, that is, calling into play those parts of 

 the body that have not been used during the regular work. 1 

 4. It should be directed toward the weak rather than 

 toward the strong parts of .the body. 5. When one is 

 already tired from study, or other work, it should be taken 

 with moderation or omitted for the time being. (For exer- 

 cise of the heart muscle and the muscular coat of the blood 

 vessels see pages 55 and 57.) 



Massage. In lieu of exercise taken in the usual way, 

 similar effects are sometimes obtained by a systematic rub- 

 bing, pressing, stroking, or kneading of the skin and the 

 muscles by one trained in the art. This process, known 

 as massage, may be gentle or vigorous and is subject to a 

 variety of modifications. Massage is applied when one is 

 unable to take exercise, on account of disease or accident, 

 and also in the treatment of certain bodily disorders. A 

 weak ankle, wrist, or other part of the body, or even a 

 bruise, may be greatly benefited by massage. The flow 

 of blood and lymph is stimulated, causing new materials 

 to be passed to the affected parts and waste materials to 

 be removed. Massage, however, should never be applied 

 to a boil, or other infected sore. The effect in this case 

 would be to spread the infection and increase the trouble. 



Summary. Motion is provided for in the body mainly 

 through the muscle cells. These are grouped into working 

 parts, called muscles, which in turn are attached to the 

 movable parts of the body. The striated muscles, as a 



i Walking is considered one of the very best forms of counter-active exercise 

 for the brain worker (page 328). 



