[22 THE FIRST BOOK OF FARMING 



up on other plants or objects by means of spring- 

 like tendrils which twist about the object and so 

 hold up the slender stem. On the grape vine these 

 tendrils are slender branches. On the sweet pea 

 and garden pea they are parts of the leaves. The 

 trumpet creeper and English ivy climb by means of 

 air roots. The nasturtium climbs by means of its 

 leaf stems. 



Other stems get up into the light and air with 

 their leaves by twining about upright objects. For 

 example, the morning glory and pole bean. 



Some stems will be found that spread their leaves 

 out to the sun by creeping over the ground. Sweet 

 potato, melon, squash, and cucumber vines are ex- 

 amples of such plants. 



One use of the stems of plants then is to support 

 the leaves, flowers and fruit, and expose them to 

 the much needed light and air. 



Experiment. Get a piece of grape vine and cut 

 it into pieces four or five inches long; notice that 

 the cut surface appears to be full of little holes. 

 Cut a piece from between joints, place one end in 

 your mouth and blow hard. It will be found that 

 air can be blown through the piece of vine. Now 

 pour about an inch of water in a tumbler or cup 

 and color it with a few drops of red ink. Then 

 stand some of the pieces of grape vine in the col- 

 ored water. In a few hours the colored water will 

 appear at the upper ends of the sticks. Capillary 

 force has caused the colored water to rise through 

 the small tubes in the vine. Repeat this experiment 



