Ferns and Their Allies 199 



6. Why are the leaves of ferns and their alUes considered to be true leaves? 



7. Why are ferns and their allies classed as Embryophytes? 



8. Why are the ferns and their alhes considered to have true vascular tissues? 



9. Contrast the sporophytes and gametophytes of ferns with those of true mosses. 



10. In what ways are the gametangia (sex organs) of Tracheophytes similar to 

 those of the Bryophytes but different from those of the Thallophytes? 



11. Describe the structure and function of stomata. 



12. Describe the type of young gametophyte formed from a germinating spore 

 in club "mosses," horsetails, and ferns. 



13. Describe how the multicellular sporangia are borne in ferns, horsetails, and 

 club "mosses." 



14. Why is water necessary for fertilization in ferns? 



15. Describe the structure and function of the annulus. 



16. Compare the alternation of generations in ferns with a similar phenomenon 

 in horsetails and club "mosses." 



17. Describe the structure and function of the suspensor. 



18. In what ways do Lyco podium and Selaginella differ? 



19. In what ways do Pteridium and Poly podium differ? 



20. Why must there be a reduction in the number of chromosomes previous to 

 fertilization? 



21. Describe the structure and function of the "foot." 



22. Discuss the functions of spore mother cells. 



SELECTED REFERENCES* 



Bower: The Ferns (3 vols.), Cambridge University Press. 

 Durand: Field Book of Common Ferns, G. P. Putnam's Sons. 

 Small: Ferns of the Southeastern States, Science Press Printing Co. 

 Smith: Cryptogamic Botany (vol. 2): Bryophytes and Pteridophytes, McGraw- 

 Hill Book Co., Inc. 

 Verdoorn: Manual of Pteridology, Chronica Botanica Co. 

 Wherry: Guide to Eastern Ferns, Science Press Printing Co. 



*Also refer to textbooks in list of references on p. 149. 



