PLANT PROPAGATION 



103 



inches (picture negatives cleaned in hot water are admirable for 

 this purpose). Upon one of the glasses put a layer of wet cotton 

 wadding about half an inch thick. Arrange the seeds (which have 

 been soaked for 24 hours) with their hilums in several different 

 positions, and place on top of them the second plate of glass. Tie 

 strings about the two glasses, and stand the "garden" in about an 

 inch of water. The water will rise between the glasses and keep the 

 developing seedlings moist. After the seeds have begun to sprout, 

 turn the " garden" so that it rests on another edge, and note the 

 effect on direction of growth of the hypocotyl. 



Observations to be made on the development of each seed 



1. What part of the seedling first appears above ground ? (Make 



drawings.) 



2. Does this part come up straight or in the form of an arch ? 



3. What kind of veining is found in the leaves ? 



4. How many cotyledons are present, and what is their use ? 



5. In what direction does the main root tend to grow ? the sec- 



ondary roots ? 



110. Comparison of seeds and seedlings. Study No. 53. 

 (Optional.) 



Soak and plant at home as directed under Materials (107), 

 several kinds of seeds. Study the seeds and seedlings, and fill out 

 in your note-book a table like the following : 



