LABORATORY AND FIELD WORK 417 



and note the path through which the liquid has been con- 

 ducted. Can you detect vessels with the hand lens? Perform 

 the same experiment with stems of other plants and compare the 

 results. 



6. Place a young potted bean plant, preferably one five or six 

 inches high, upright in a dark box which has a small opening in 

 one end. Examine it after twenty-four hours, and again after 

 forty -eight hours. What changes do you observe ? 



7. Place a similar plant on its side in a perfectly dark box. 

 Examine it after two days. What changes have taken place? 

 What do you conclude from this and the preceding experi- 

 ment as to the responses of a stem to the stimuli of light and 

 gravity ? 



8. Mark a young bean stem at intervals of one-fourth inch with 

 India ink; after twenty -four hours note where growth has taken 

 place. Compare this result with that of your similar study of the 

 bean root. 



9. Secure portions of stems of alder, cherry, willow, maple, lilac, 

 and other plants. Note the positions of buds. What is their 

 relation to leaves or leaf scars? Note especially the buds of the 

 lilac. Do you observe anything characteristic of them which ex- 

 plains the shape of a lilac bush ? 



10. Place portions of various woody stems in a dish containing 

 water, and if possible cover the whole with a larger jar. Examine 

 the stems from day to day for a week or more. Do you find that 

 growth has taken place at regions where no buds were present? 

 What happens when a willow tree has the greater number of its 

 branches removed? 



11. Tear apart a fairly large bud, such as the winter bud of a 

 lilac or of a horse-chestnut. What covers the bud on the outside? 

 What structures do you find inside? How many leaves does it 

 contain ? What is at the center of the bud ? 



12. Study thorns of various types. Which of them seem to be 

 branches? 



13. If an orchard containing young trees is available, it may be 

 possible to make a study of various types of grafting, budding, 

 and layering. Compare the methods used with those described 

 in the text. If possible, some work in actual budding or grafting 



