530 MAN CONTROLS HIS ENVIRONMENT FOR WEALTH 



and opium come from the poppy. Many of our pleasant oils and 

 flavors, as eucalyptus, wintergreen, and peppermint, come from 

 plants. 



Tobacco, although a poisonous plant because of the nicotine it 

 contains, is, nevertheless, one of this country's largest crops. Over 

 1,200,000,000 pounds were raised in 1927, having a total value of 

 about $266,000,000. Atropine and belladonna, both poisons used 

 as drugs, are from plants related to the tobacco. 



Practical Exercises 9. Make a table to show the value of the chief fiber 

 crops in your section of the country during the past year. Get information 

 from your local Chamber of Commerce. 



What other crops are of value in your locality and why ? 



The use of tobacco has greatly increased since the World War. Give three 

 possible reasons why this is so. 



Self-Testing Exercise 



Our clothes lines are made from (1). Burlap bags are 



made from (2). Linen comes from (3). The 



coca tree gives us (4) (5), although a poisonous 



plant, is one of the largest crops we raise (6) is the most 



important fiber plant in this country. 



PROBLEM III. WHAT IS THE VALUE OF ANIMALS AS FOOD 



FOR MAN? 



Indirect use of animals as food. Just as plants form the food 

 of animals, so some animals are food for others. Protozoa and 

 many forms of tiny plants, known as plankton, which are swarm- 

 ing near the surface of bodies of fresh and salt water, form the food 

 supply of many forms of life. Many fish live on plankton or on 

 smaller fish which feed on plankton. Some fishes, as the menhaden, 

 the shad, and others, are provided with gill rakers by means of 

 which they strain these minute organisms from the water. Other 

 fishes are bottom feeders, as the blackfish and the sea bass, living 

 almost entirely upon mollusks and crustaceans. Still others are 

 hunters, feeding upon smaller species of fish, or even upon their 

 weaker brothers. Such are the bluefish, the weakfish, the barra- 

 cuda, and others. The right whale, the largest of all mammals, 

 strains protozoa and other small animals and plants out of the 



