258 



ELEMENTARY SCIENCE 



plant kingdom. These first plants are of two general 

 kinds, and you have seen both kinds. One kind consists 

 of what are called Alga. You have seen 

 green, thready growths in the water, 

 green "scum" in ponds, green stains on 

 tree-trunks, etc. These are Algae, our 

 simplest green plants. They have no 

 leaves or stems or roots, and produce 

 neither flowers nor seeds. If you have 

 visited the seashore, you have seen 

 curious-looking plants thrown up on 

 the beach by the waves. Some of 

 them are brown or green and leathery; 



FIG. 98. Seaweed. others are delicately branching and red- 

 After J. M. COULTER. 



dish. All of these are Algae that have 



learned to live in sea-water, and to live also buffeted about 

 by the tides and storms. Some of them are quite large, 

 and they are commonly called "seaweeds" 

 , (see Figs. 98 and 99). In many places along 

 the seacoast these seaweeds are thrown up on 

 the beach in great numbers, and they have 

 been found to be very useful as fertilizers. 

 For this reason they are carted to the fields 

 and spread over them like manure. 



The other group is called the Fungi, and 

 they differ from the Algae in not containing 

 any green material. For this reason they 

 are unable to make their own food, and must 

 get it from other plants or from animals. 

 Some of them attack living plants or animals to obtain food, 

 and when they injure them they produce what we call dis- 

 eases. Many of our diseases, such as typhoid fever, diph- 



FIG. 99. Sea- 

 weed. After 

 J.M. COULTER. 



