The Nature of Plants 13 



4. Transplant two small plants, cutting one back severely 

 and leaving the other tmtrimmed. Watch their behavior. 



5. Perform the experiment in osmosis described on page 6. 



6. Place freshly cut stems bearing leaves and flowers in red 

 ink, and set in the sunshine. After a few hours cut through the 

 stems and leaves at various points to see where the sap flows. 



7. Invert a glass jar over growing plants (Fig. 9). Notice the 

 moisture that collects on the inside. (Best performed when the 

 sun is shining.) 



8. Cover green plants to keep light from them. After a few 

 days note how the green color (chlorophyll) begins to fade. 



9. Compare the various forms of stamens and ovules in as 

 many different flowers as you can. 



10. Just as a flower begins to open, cut off its stamens and tie 

 a paper bag over it to protect from other pollen. See if the flower 

 can set seed. (The dandelion would, but it is an exception.) 



11. Plant a number of large seeds, such as beans or corn, in 

 damp sand or sawdust. Dig up some each day and note the 

 progress of germination. 



12. Plant a few beans, and as soon as the plants come up, re- 

 move from some of them the two thick leaves with the bean hull 

 on them. These leaves are really the larger portion of the orig- 

 inal seed. Do not remove the little bud between them. After a 

 week, note the growth of the different plants. Why are some of 

 the plants stunted ? 



13. Plant seeds of the same kinds in soil, sand, and sawdust, 

 and see if they germinate equally well. What is necessary for 

 germination ? 



