



CHAPTER VII 



HOW THE PLANT USES THE FOOD IT MAKES 



IN order to make starch, soil food and air food must 

 meet in the leaf, and the force or energy of the sun- 

 shine be used to join them together. Sap must come 

 up from the root, and the food, after it is made, must 

 go down into the stem again. 



How does the soil food get to the leaf? We know 

 that it goes up the stem in the water or sap which comes 

 from the root. We can see how this is if we cut off a 

 geranium or other plant, and put the cut end of the stem 

 in red ink (or into water containing a little eosin, one 

 of the Diamond dyes). After a few hours we may cut 

 the stem into small pieces, arid we then see that the 

 colored water has gone up the stem in certain places only. 

 You will see if you try to cut them that these places 

 are really long strands of tough woody fiber. Under 

 the microscope they look like bundles of tubes. In 

 these tubes or pipes the water or sap goes up the 

 stem. 



When we cut the leaf and its stalk into small pieces, 

 we see that the colored liquid has passed from the stem 

 up into the stalk and veins of the leaf, and out into the 



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