21. In graceful walking, should the toes or the heel touch the ground first? What are the causes of deformed feet? What is the natural position of the big toe? Did you ever see a big toe lying in a straight line with the foot, as shown in statuary and paintings? How should we have our boots and shoes made? What are the effects of high heels? Of narrow heels? Of narrow toes? Of tight-laced boots? Of thin soles? What are the rickets? Cause of this disease? Cure? Is there any provision for remedying defects in the body? Name one. 22, 23. What is a felon? Cure? Cause of bowlegs? How can they be prevented? Causes of spinal curvature? Cure? What is the correct position in sitting at one's desk? Is there any necessity for walking and sitting erect? Any advantage aside from health? Describe the bad effects of a stooping position. What is a sprain? Why does it need special care? What is a dislocation? How is it generally caused? How soon should it be treated? 269. What relation does man, in his general structure, bear to other vertebrates? Mention some marked physical peculiarities which distinguish him from the lower mammals. 270, 271. Describe the state of a fracture a week after its occurrence. What is this new formation called? What marks the termination of the first stage of curative progress? How do the broken ends of the bone now appear? What is the state of the fracture at the end of the second stage? What is the condition of the callus at this time? Describe the third and last series of changes. Is the process of union completed sooner in old people or in young? In the upper or lower extremities? In smaller animals or man? What length of time is required to heal a broken arm? A broken leg? 272. What gives the human hand its peculiar prehensile power? What advantage has the human thumb over that of the ape? Compare the foot of man with that of the ape. What peculiarity of the foot is particularly noticeable in man? Contrast the function of the great toe in man and in the ape. 273. Are the toes naturally flexible? How are their powers crippled? Give an instance in which the toes were trained to do the work of the fingers. 274. Why are an elastic step and a graceful carriage such rare accomplishments? What is the natural shape of the foot? Which is the longer, the great toe or the second toe? Is an even-sided symmetry necessary to the beauty of a boot? THE MUSCLES. 29. What relations do the skeleton and the muscles bear to each other? How is the skeleton concealed? Why is it the image of death? What are the muscles? How many are there? What peculiar property have they? Name other properties of muscles. _Ans_. Tonicity, elasticity. 30. How are they arranged? Where is the biceps? The triceps? How do the muscles move the limbs? Illustrate. What is the cause of squinting? Cure? (See p. 244.)