98 MORPHOLOGY AND LIFE HISTORY 



G. Physiology: 



1. Is photosynthesis possible with the thallus? The 

 antheridiophore? The archegoniophore? What 

 correlation do you find between structure and 

 function in this respect in the archegoniophore? 



2. Explain the nutrition of the non-chlorophyll-bear- 

 ing cells of the gemmae. What is their nutritive 

 relation to the gemma as a whole? 



3. Is the gametophyte capable of an independent exist- 

 ence? Thoughtfully consider and then describe 

 the correlation between structure and function in 

 this respect. 



4. In mature specimens grayish drops of liquid may 

 often be found exuding on the dorsal surface of the 

 antheridiophores. This liquid contains active an- 

 therizoids, or sperms. Mount some of it in water, 

 and, under high power, observe the motion, organs of 

 motion, and other structural features of these sperms. 



5. When longitudinal sections of mature archegonia 

 are mounted in water containing active sperms the 

 behavior of the latter toward the former may be 

 readily observed. If your material is suitable, 

 make these studies. 



6. How, only, can the sperms reach the egg? What 

 external conditions would be favorable for this? 



7. Of what advantage is it to the sporophyte to have 

 the egg retained in the venter of the archegonium? 

 Would this be of as great advantage in any aquatic 

 plant as in a land plant? Why? 



8. Is the small size of the sperms of any special advan- 

 tage to the plant? Explain. 



9. Explain any advantage in the greater height of the 

 mature archegoniophore over that of the antheridio- 

 phore. 



