234 BIOLOGY AND HUMAN LIFE 



4. What use can we make of our knowledge of the reflexes of other 

 organisms ? 



5. How can we make use of our knowledge about human reflexes ? 



6. How can we tell whether simple organisms and root hairs choose 

 what they absorb ? 



7. How could we show that the skin is sensitive to light ? 



8. How can we show that leaves and stems are sensitive to light ? 



9. How could we show whether roots are sensitive to light ? 



10. How can you tell whether the distinctive quality of anything 

 recognized through the mouth is an odor or a taste ? 



IL Through what organs are we capable of finding out only about 

 things that touch the body? 



12. Through what organs do we find out about things at a distance ? 



13. What practical use do we make of the workings of the semi- 

 circular canals ? What practical use do we make of our knowledge of 

 their workings ? 



14. In what ways do reflexes give organisms control over their 

 environment ? 



15. In what ways do reflexes fail to give organisms control of their 



environment ? 



16. How can we tell that there are vibrations (light or sound, for 

 example) that produce no effect upon our sense organs ? 



REFERENCE READINGS 



Hough and Sedgwick. The Human Mechanism, pp. 242-276, 395-396. 

 Darwin, Charles. The Formation of Vegetable Mold through the 

 Action of Worms, chaps, i and ii. Habits of Worms. 



