CHAPTER XXIX 

 THE UTILIZATION OF FOOD IN ANIMALS 



340. Questions for Discussion. 1. Why is it necessary for attention 

 to be constantly directed to sources of food for men? 2. What would 

 be the result if all the world's cereal crops should completely fail for 

 one season? 3. Why is it that in the wake of armies when they have 

 advanced, one of the first things done is to try to get the devastated 

 soil planted with some kind of agricultural crop? 4. Which is more 

 dependent upon the other, city or country? Why? 5. Why is it highly 

 important to have a balanced ration for men and domestic animals? 

 6. Is the chief purpose of mastication of food that of breaking it up so 

 that it can be swallowed ? 7. In human mastication what function is 

 j>erformed by the saliva? Is it of any value to give the saliva prolonged 

 time to act? 8. If food is swallowed hastily can the saliva do its part 

 of the work of digestion as well after the food is swallowed as before ? 

 9. In what ways do the secretions of the liver and pancreas affect the 

 processes of digestion? 10. How does the digested food find its way 

 into the circulatory system ? 11. Is it important as a phase of nutrition 

 that food should be palatable ? Should we be nourished by good food 

 just as truly if it were not pleasant to the taste as if it were pleasant? 

 12. Rub the tongue quite dry, then place some sugar on it, and see if 

 you taste the sugar. 13. Close your eyes and allow someone to place 

 coarse sugar or fine salt on your tongue and see whether you can 

 detect at once which you have. 



341. Food a universal necessity. The quantity of food con- 

 sumed by man and the domestic animals is very great indeed, 

 and a supply of food is at all times a matter of the greatest 

 importance. In times of war the food supply is often spoken 

 of as a means of endurance. Lack of food has caused the 

 surrender of cities, defeated armies in the field, changed the 

 policies of nations, and caused the loss of thousands of lives. 

 In olden times famines were of common occurrence, because 

 when food failed in certain places there were no means of 



