66 ELEMENTS OF AGRICULTURE 



grows older, are found concentrated in the seed, and 

 the stem is then composed almost entirely of woody 

 matter. 



EXPERIMENTS 



Over a patch of green grass place a box or any other covering 

 to exclude the sunlight. In a few days the grass begins to lose 

 its color and in time becomes white. If exposed to the sun again 

 it in time regains its color and continues to grow. 



Select a growing leaf of bright green color, and without talcing 

 it from the plant cover a portion of the surface exposed to the 

 light with black paper. The paper may be pinned or sewed on 

 and should fit close enough to cut off all the light. In time the 

 portion of the leaf under the paper loses its color, turning 

 white. By cutting the paper into proper shapes, figures or let- 

 ters may be formed on the leaf. 



Questions 



1. Haw do plants take up water from the soil? 2. How do 

 plants take up their mineral food from the soil ? 3. What is 

 the juice found in the stems of plants called? 4. In what way 

 does sap aid in the growth of a plant? 5. In what form does 

 the plant take its food from the air ? 6. What well known 

 substance is formed in the leaves of plants? 7. Of what is 

 starch formed? 8. How are the compounds formed in the 

 leaves distributed? 9. Are all parts of plants of the same 

 composition? 10. As the plant grows, in what respect does it 

 change in composition? 11. Where is much of the plant food 

 finally concentrated? 



