THIRD GRADE FALL WORK 145 



possible chance to do its work. At the proper time the 

 seeds become loose so that a faint wind will take them off. 



LESSON XVIII 

 SEED DISTRIBUTION BY WATER 



Besides animals and the wind, what other agent sometimes 

 distributes seeds? Test many kinds of seeds, and find 

 which will float on water. What plants grow on or near 

 water? What kind of seeds have they? Examine ditches 

 and banks of streams. Note the vegetation growing there, 

 and account for its presence. 



How may the land of a careful farmer become weedy by 

 using irrigating water that flows through the field of a care- 

 less neighbor ? Many seeds are carried on the water and dis- 

 tributed in this way. Collect and preserve samples. Discuss 

 the cocoanut in this connection. 



LESSON XIX 

 SELF-DISTRIBUTING SEEDS, ETC. 



Some plants arrange to distribute their own seeds. Some 

 pods, when they get dry, suddenly burst and throw the con- 

 tained seeds several yards away. The squirting cucumber 

 is filled with juice in which the seeds float. At the proper 

 time this ferments, developing enough gas to burst the cover, 

 and sends the floating seeds quite a distance. Vines often 

 grow a great distance, and develop fruit and seeds a long 

 way from the parent root and stem. 



In the activities of commerce, seeds are often accidentally 

 scattered by man. In this way Old World plants have been 

 introduced into the Western Hemisphere, greatly to -our 



NAT. STUDY IO 



