88 STRUCTURE AND ATTACHMENTS OF MUSCLES. 



CHAPTER IV. 



MusclesTheir Structure, Attachments, and Conditions of Ac- 

 tion Necessity of Arterial Blood and of Nervous Influence 

 Illustrations Muscles act by alternate Contraction and Re- 

 laxation Fatigue consequent on continuing the same Attitude 

 explained Injuries of Spine from Neglect of this Law, and 

 from sedentary Occupations in School The Mind ought to be 

 engaged in Exercise as well as the Body Superiority of 

 cheerful Play and amusing Games A dull Walk the least 

 useful Exercise Influence of Mental Stimulus illustrated by 

 Examples Exercise to be proportioned to Strength Laws 

 of Exercise. 



HAVING examined the nature and uses of the skin, 

 we may next proceed to consider the important 

 system of organs, lying almost immediately under 

 it, viz. the Muscles ; ^hich, although in constant 

 activity during our waking hours, and of indispen- 

 sable necessity to man in every movement which he 

 makes, are perhaps less familiarly known than 

 almost any other part of the body. As the study of 

 the muscular system involves an exposition of the 

 principles which ought to regulate exercise, it can 

 scarcely fail to excite the attention of the general 

 reader, and especially of those who, as parents or 

 teachers, are interested in the education of the 

 young. 



The muscles are those distinct and compact bun- 

 dles of fleshy fibres which are found in animals im- 

 mediately on removing the skin and subjacent fat; 

 and which, although perhaps not known to all under 

 their generic or scientific name, are familiar to 

 every one as constituting the red fleshy part of 

 meat. 



Every muscle, or separate bundle of fleshy sub- 

 stance, is composed of innumerable small fibres or 



