294 NATURE STUDY AND AGRICULTURE 



All the stems you have examined thus far are dicots. 

 Through what part of the stem of a dicot, then, does the 

 water move upward ? 



Place some monocot stems in the red ink solution to 

 determine where the water travels through them. A corn 

 plant nine or ten inches high, a stem of a tulip flower, a 

 trillium, an asparagus stem, or any lily will do for this 

 experiment. The spots in the sections show the ends of 

 bundles of fiber. So in monocots the water travels through 

 these fiber bundles. 



Is all the water taken into the plant used in the plant ? 



Experiment. — Cover with glazed or writing paper the 

 top of a pot in which a plant is growing vigorously. To 

 do this slit the paper to the center and cut out a space big 

 enough for the stem. Now slip the paper around the stem 

 and tie around the top of the pot. Turn a glass jar over 

 the plant and let it stand in the light a few hours. What 

 do you find on the glass ? Where did the drops of water 

 come from? This process is called transpiration. The 

 leaves transpire, or give out moisture constantly. With a 

 microscope we should be able to find in the thin skin or 

 covering of a leaf small openings. These are called 

 stomata. One is a stoma. It is through these that trans- 

 piration chiefly takes place. If you have a pair of bal- 

 ances you can find out by a simple experiment which side 

 of a leaf contains the more stomata. Take from a bean, 

 sunflower, geranium, or nasturtium two leaves of the same 

 size. Balance these on the pans of the scales after having 

 covered the upper surface of one leaf and the lower surface 

 of the other with vaseline. Watch for several hours. 

 Which one has lost the least water during this time ? What 



