EXERCISE 48 



The green plastids which we noted flowing in the protoplasm when we studied the plant cells of the 

 ilodea (Exercise 19) are sometimes absent in leaves or in parts of leaves. The coleus and certain other 

 )lants have variegated leaves of this character. 



Problem. Has chlorophyl (leaf green) anything to do with the making of starch ? 

 What to use. A plant having a variegated, partly green leaf. 



What to do. Make a diagram of one leaf, indicating green area ; keep the plant in sunlight for a 

 few hours, then break off the leaf ; remove chlorophyl as in Exercise 46 ; test for starch. 



Record. Note the portion of the leaf that has built up starch ; make a drawing and compare with 

 )ur first sketch. Explain the results. 



NOTE. The part that chlorophyl plays in the process of starch-making is not yet certain. In terms of a manufac- 

 aring process, the chlorophyl grains are the machinery of the factory. The sunlight activates the machinery or makes it 

 fork, and the raw materials (made up of compounds of the elements C, O, and H) are separated and recombined in the form 

 }f sugars and starches. 



Questions. 1 . What living things do you know that have no chlorophyl ? 

 2. How do such plants and animals get their food ? 



[53 



