To show that growing leaves contain starch, i. Represents 

 a green cotton leaf as picked from the plant. 2. Is the same 

 leaf after taking out the green coloring matter; the leaf is 

 white. 3. The same leaf after treatment with weak iodine 

 turned to a dark purple, showing the presence of starch. 

 (Drawings by M. E. Feltham.) 



To show that starch disappears from the leaf when the 

 plant is placed in the dark. The plant from which was taken 

 the leaf represented in Fig. 61, was immediately placed in a 

 dark closet for 24 hours. Then leaf 4 was taken from it ; 5 

 represents this leaf after the chlorophyl was taken from it; it 

 is white ; 6 is the same after treatment with iodine. The leaf 

 remains white, showing no starch. (Drawings by M. E. Felt- 

 ham.) 



