THE LIVING PLANT 35 



Procedure. Place a piece of thin leaf under a microscope. Examine. 

 In some leaves the cells can be seen distinctly, and in most leaves the 

 green chlorophyll granules can be seen. 



5. Materials. Geranium or other leaves; microscope, glass slides. 

 Procedure. Strip off a portion of the epidermis of a leaf, mount it 



in water on a slide and examine it under a microscope for a view of the 

 stomata. Notice the guard-cells. Make an enlarged drawing of the 

 surface view of a stoma. Where do you find the most stomata, on the 

 upper or lower surface of the leaves examined? Account for this fact. 



6. Materials. Various kinds of plants and trees. 



Procedure. Examine the leaves of a number of plants and trees. 

 Classify them into the following: (a) simple and compound leaves; 

 (b) netted- veined and parallel- veined leaves; (c) leaves with and 

 without stipules; (d) which of the plants in the list examined would 

 you expect to have endogenous stems and which exogenous? 



7. Materials. Trees of the apple, pear, apricot, plum, or others 

 having fruit-spurs. 



Procedure. Study and draw different types of fruit-spurs. Compare 

 the length of internodes on a spur with that on an ordinary branch. 

 Are the leaves and buds arranged in the same way on a spur as on an 

 ordinary branch? In what respects does a spur differ from an ordinary 

 branch and in what respects is it similar? 



8. Materials. Various trees. 



Procedure. Study leaf-buds. Starting at the base of a bud, remove 

 the bud-scales in order. Compare the arrangement of the scales on a 

 bud with that of the leaves on a stem, and also compare the number 

 of leaves on a stem with the number of scales on a bud. How does a 

 bud differ from a stem? 



9. Materials. Trees just before or just at blossoming and leafing- 

 out time in the spring. 



Procedure. Examine trees of various kinds for leaf-buds, flower-buds, 

 and mixed buds. Keep a list of the types of buds found on the various 

 trees. 



EXERCISE II. Exercises to determine the growing portions of plant 

 parts. 



1. Materials. Water-proof ink; ruler; young growing pea, corn, 

 or other plants. 



Procedure. With water-proof ink place marks one millimeter apart 

 along a small rootlet, along the growing stem, and along the main rib 

 of a leaf. In like manner mark the entire surface of a leaf in squares. 



