THE HUMAN ORGANISM 297 



26. How can the activity of the striped muscles influence the unstriped 

 muscles ? How can the activity of the smooth muscles influence the 

 striped muscles ? 



27. How can a state of mind influence the striped muscles ? the 

 smooth muscles ? 



28. What kinds of exercise are good for the blood ? for the bones ? 

 Why? 



29. What are the advantages of real work over drill ? What are the 



disadvantages ? 



30. What are the advantages of w^ork over games ? What are the dis- 

 advantages ? 



31. What are the advantages of watching games over playing them? 

 What are the disadvantages ? 



32. What connection is there between our clothes and our health ? 



REFERENCE READINGS 



Hough and Sedgwick. The Human Mechanism, chap, ii, The Anatomy 

 of the Human Mechanism ; chap, xvii, Muscular Activity. 



CocKERELL, T. D. A. Zoology, chap, xliv. The Structure of Vertebrates. 



Keith, Arthur. The Engines of the Human Body, "How Muscles 

 Operate" (extract in C. H. Ward's "Exploring Nature," pp. 198- 

 208). 



United States Bureau of Fisheries. Report for igig, Appendix 6, Frogs, 

 their Natural History and Utihzation. 



Public Health Reprint 779, Posture of School Children. 



United States Department of Agriculture, Bureau of Chemistry. Bul- 

 letin 126, The Harmful Effects of Acetanilid, etc. 



