EXERCISE 2 

 DOES WATER EVAPORATE FROM SHOOTS? 



Materials. Geranium plant ; two six-ounce, wide-mouthed bottles ; 

 cork stopper or wad of cotton ; support with clamp. 



Directions for work. While the geranium is suggested for this 

 study, almost any common plant will answer if the leaves are 

 small enough to be treated as directed below. Trees or shrubs 

 out of doors may be used. 



Insert the end of a leafy 

 shoot into one of the bottles 

 and support the bottle in such 

 manner that the shoot will be 

 in approximately natural posi- 

 tion. Select a cork stopper 

 which fits the bottle and punch 

 a hole through it large enough 

 to accommodate the stem 

 which has been inserted into 

 the bottle. Split the stopper 

 through the center of the hole 

 and place the two halves in 

 the neck of the bottle with the 

 stem in the hole. (See Cald- 

 well and Eikenberry, " Elements of General Science," Fig. 62.) 

 If a large stopper is not at hand, the neck of the bottle may 

 be plugged with cotton. For purposes of comparison, support 

 a similar bottle, stoppered but with no leaves in it, near the 

 first. If a potted plant is used, place it in a light place. 



Examine at intervals during the next hour in order to de- 

 termine whether there is evidence that water is given off. 



What are the facts that you observe ? What are your con- 

 clusions regarding the loss of water from shoots? 



Review the directions for writing notes as given in connec- 

 tion with the previous exercise, and write notes on this exercise. 



Reference 



BERGEN and CALDWELL. Practical Botany, p. 18. 



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