MANUAL OF NATURE STUDY. 159 



function of different organs or tissues. Micro- 

 scopic study should be pursued whenever it can be 

 done to advantage and will aid to clearer compre- 

 hension of physiological facts. Physics and 

 chemistry, in so far as a knowledge of them is 

 necessary to make clear the processes of Physi- 

 ology, should be studied in connection with this 

 subject. 



The following outline is suggestive for the work: 



I. Study the Framework of the Body — The Skeleton. 



{a) Composed of bones and ligaments. Ar- 

 ticulation of bones, the synovial fluid 

 and its use. 



{V) Structure,, chemical composition and use 

 of bones as levers. 



(t) Relation of their structure and proper- 

 ties to their uses. Growth and repair 

 of bones, effects of food, exercises, 

 habits, etc. Care of the bones. 



II. The Muscles. 



{a) Structure and properties of muscular 

 tissue, the voluntary and involuntary 

 muscles and their arrangement. Ner- 

 vous control of muscular action. 



{h) Changes that the muscle cells undergo 

 during contraction, carbon dioxide, 

 uric acid and other waste material, the 

 oxidation of food substances, heat. 



