412 THE NON- VASCULAR PLANTS 



B. 7. Describe alternation of generations in liverworts, defining 

 sporophyte and gametophyte. 



C. 8. How are foliose liverworts to be distinguished from thallose 

 ones ? How are they to be distinguished from mosses ? 



D. 9. Describe the sporogonium of Anthoceros. Why is it of 

 especial interest ? 



E. 10. Describe the relations between mosses, liverworts, and 

 lichens as to growth upon rocks. 



Section 74. 1. Describe the habits of growth of mosses. 2. De- 

 scribe the structure of a moss plant, defining rhizoid. 



A. 3. Describe the sporogonium of moss, defining foot, seta, and 

 capsule. 4. What is a protonema ? 5. Describe sex reproduction in 

 a moss. 



B. 6. Explain the advantage to plants in having photosynthesis 

 and spore-production performed by the same generation. 7. Why 

 is it that gametophytes are limited in stature ? 



