THE LEAVES 63 



pea or bean in proper soil in a pot and set in a 

 dark cellar and then cover with, a bucket or a box. 

 Give the seedling the proper amount of water, which 

 will be less than if grown in light. After a time 

 shoots will be formed which will be very much 

 different from those grown from similar seedlings 

 or plants in the light. 



Lay a broad board on the grass, and note the 

 color of the blades beneath a week later. Not only 

 will the chlorophyl be absent, but the stems and 

 leaves will be greatly changed in form and size. 

 The stems will be two or three times as long as 

 usual. This seems to be a method by which the 

 plant gets its leaves and stems up to sunlight when 

 they are covered by anything or overshadowed by 

 other plants. Species like the narcissus, which have 

 sword-shaped leaves with no petiole or stem above 

 ground, elongate the blade of the leaf itself in this 

 effort to get up to light. 



73. Capacity of leaves for the absorption of light. 

 — Take any tube of wood, metal, or paper an inch 

 or more in diameter, and fasten a leaf over the end. 

 This may be done by turning the margins back over 

 the tube and tying a string around the tube at that 



