LEAVES FUNCTION OR WORK 



105 



calcium? iron? phosphorus? 103. Where is all the starch in the 

 world made? What does a starch -factory establishment do? 

 Where are the real starch factories? 104. In 

 what part of the twenty-four hours do 

 plants grow most rapidly in length? When 

 is food formed and stored most rapidly? 

 105. Why does corn or cotton turn yellow 

 in a long rainy spell? 106. If stubble, 

 corn stalks, or cotton stalks are burned 

 in the field, is as much plant-food returned 

 to the soil as when they are plowed 

 under? 107. What process of plants is 

 roughly analogous to perspiration of ani- 

 mals? 108. What part of the organic 

 world uses raw mineral for food? 109. Why 

 is earth banked over celery to blanch it? 

 110. Is the amount of water transpired 

 equal to the amount absorbed? 111. Give 

 some reasons why plants very close to a 

 house may not thrive or may even die. 

 112. Why are fruit-trees pruned or thinned 

 out as in Fig. 129? Proper balance be- 

 ^ tween top and root. 113. We have learned 

 that the leaf parts and the root parts work 

 together. They may be said to balance 

 each other in activities, the root supplying FlG J30 _ AN APPLE 

 the top and the top supplying the root TREE, with suggestions 

 (how?). If half the roots were cut from as to pruning when it 

 a tree, we should expect to reduce the top is set in the orchard. At 

 also, particularly if the tree is being trans- a is shown a P runed 

 planted. How would you prune a tree or 

 bush that is being transplanted? Fig. 130 may be suggestive. 



FIG. 129. BEFORE AND AFTER PRUNING. 



