CHAPTER V 



THE WORK OF STEMS 



The work of the stem and the work of the leaf are 

 closely connected. We have learned that the leaf 

 needs a constant supply of water; this is absorbed by 

 the root, but in order to reach the leaves it must be 

 conveyed upward through the stem. Where does the 

 water travel in the stem? Cut off a leafy branch (pref- 

 erably of Squash, Sunflower or Geranium), and place 

 the cut end in water in which enough eosin has 

 been dissolved to give it a bright red color. Place it 

 where the conditions are favorable for evaporation, and 



in an hour or so cut off the 

 stem two or three inches 

 from the lower end; if the 

 liquid has risen in the stem 

 trace it upward by means of 

 successive cuts. Make a dia- 

 gram showing the portion of 

 the stem in which the colored 

 liquid rises. If a Squash 

 stem be used, the appearance 

 when cut across resembles 



(224) 



bast 

 weed 

 bast 



131. Diagram of cross-section of Squash 

 stem: istr) strengthening: fibers. 



