QUESTIONS AND SUGGESTIONS 449 



Section 77. 1. Describe the structure of Equisetum. 2. Describe 

 its reproduction, denning sporophyll and strobilus. 



Section 78. 1. Describe the ground pine. How does it differ 

 from ferns in the manner of bearing sporangia? 2. Describe Sela- 

 ginella, denning heterospory, megaspore, megasporangium, and 

 megasporophyll. 3 . Illustrate by diagram the life history of Selaginella. 



Section 79. 1. Give examples of the Contferm. 2. What sort of 

 organ is a pine cone ? Explain its structure.' A. 3. Distinguish be- 

 tween the staminate and pistillate cones of Coniferce. B. 4. Describe 

 the pollen of pine and the process of pollination. C. 5. Compare the 

 pollen tubes of gymnosperms with those of angiosperms as to the tissues 

 which they penetrate. D. 6. Describe the embryo of pine. 7. De- 

 scribe the habit of pine cones as to attachment to the trees which 

 bear them. E. 8. Explain why the retention of the megaspore is 

 responsible for the formation of seeds. 9. Define siphonogamy. 

 F. 10. Explain why two sets of terms are applied to flower parts, 

 n. Show the correspondences between the new terms and the old 

 ones. G. 12. Why are pollen grains not microspores? H. 13. De- 

 scribe the female- gametophyte of gymnosperms. I. 14. Tell how 

 many generations are represented in a seed, and explain your answer. 

 /. 15. Give a summary of the life history of a gymnosperm by 

 writing and explaining a diagram of it. K. 16. Summarize the 

 chief distinguishing features of the four great groups. 



Section 80. 1. State the characteristics which distinguish gym- 

 nosperms and angiosperms from one another. B. 2. Locate and 

 describe the megasporangia of angiosperms. C. 3. Describe the 

 male gametophyte of angiosperms. D. 4. Define micropyle, integu- 

 ment, and nucellus. 5. Describe the female gametophyte of angio- 

 sperms, defining endosperm-nucleus and embryo-sac. E. 6. Describe 

 double fertilization, and one of its effects in corn. F. 7. Define 

 breeding. 8. Discuss variation and give examples of it which you 

 have noted. 9. What is meant by true to type? 10. What is 

 meant by pedigreed stock? 11. What is the best test for seed as • 

 to its possibilities of yield? 12. Look up in government bulletins 

 or elsewhere the methods used in corn or wheat breeding and re- 

 port thereon. 13. Report on the 'history of the seedless orange or of 

 some other improved fruit. 



