92 



LABORATORY EXERCISES 



plant. Also cut a slit from the edge of the cardboard to the 

 central hole. 



Use a piece of cloth, or a small brush, to "paint" the card- 

 board with melted paraffin, so that it will be water-tight ; 

 then slip the cardboard around the stem of the plant and over 

 the pot. Close the slit in the cardboard with melted wax, 

 and pack some of the soft, but not hot, wax around the stem. 



b. Over the plant put a large tumbler or a glass fruit j ar, and set 

 the plant in bright sunlight. Look at the jar from time to time. 

 Can you see a deposit of water inside it? What part of the plant 

 gives off the water? Why does a potted plant need to be watered 

 frequently? 



EXERCISE 88 

 SEEDS AND THEIR GERMINATION 



Apparatus and Materials. Germination box, or "flat," good soil, 

 pocket knife, garden beans, lima beans, scarlet runner beans, castor 



beans, squash seeds, 

 peas, corn, radish seeds, 

 red clover seeds, some 



other seeds. 



a. Make a germina- 

 tion box like that 

 shown in Fig. 35. The 

 box should be about 

 10 cm. (4 in.) deep, 50 

 cm. (20 in.) wide, and 

 60 cm. (24 in.) long, all 

 inside measure. The 

 squares will then be 5 

 cm. (2 in.) on a side. 

 The squares are marked off by thread held in place by tacks 

 that are driven into the sides of the box. The figures may be 



FIG. 35 



