52 HORTICULTURE FOR SCHOOLS 



EXERCISE III. Effect of temperature on plant growth. 



Materials. Seeds; small boxes; sawdust, sand, or soil. 



Procedure. Plant the same kinds of seeds as were used in the 

 preceding experiment in several boxes of sand or sawdust. Supply 

 each box with the same amounts of moisture, but keep them at 

 different temperatures. Note the difference in growth at the various 

 temperatures. Write your conclusions as to the effect of these tempera- 

 tures on growth. 



EXERCISE IV. Effect of moisture on the growth of young plants. 



Materials. Same as in preceding exercise. 



Procedure. Plant seeds in boxes in the same manner as in Exercise 

 III. Keep the boxes supplied with different amounts of water. Note 

 the effects of the different amounts of water on the germination of the 

 seeds and the growth of the young plants. 



EXERCISE V. Effect of soaking seeds. 

 Materials. Peas, corn, and other seeds. 



Procedure. Plant some seeds which have been soaked for a few 

 hours, and some of the same kinds unsoaked. Which come up first? 



EXERCISE VI. Stratification. 



Materials. Hard-coated seeds similar to those mentioned in para- 

 graph 58; boxes; soil. 



Procedure. Stratify some hard-coated seeds in the manner mentioned 

 in paragraph 58. Note when they sprout. 



EXERCISE VII. Seed dissemination. 

 Materials. As many kinds of seeds as possible. 

 Procedure. Study as many seeds as possible to determine the mode 

 of dissemination of each. 



EXERCISE VIII. Project exercise. 



Materials. Seeds used in project. 



Procedure. Students are requested to anticipate at this time the 

 project which they will undertake if they have not already done so. 

 They are requested to secure samples of seeds which will be utilized 

 in this project and to examine them in the light of facts brought out 

 in the chapter. Compare the seeds with those already examined, 

 noting as closely as possible all similarities and differences. Note the 

 length of time it takes for water to penetrate these seeds. If possible, 



