80 ^ MORPHOLOGY AND LIFE HISTORY 



Describe its color. Is it simple or branched? Are 

 cross-walls present? 



4. At certain points on the protonema observe buds. 

 These buds develop into either male or female game- 

 tophy tes (gametophores) . 



5. Which generation of the moss-plant always devel- 

 ops from the spore? Compare this with the case in 

 the fern. 



F. Sexual Reproduction: 



The antheridia 



1. Take a male gametophyte and, with a dissecting 

 needle, carefully remove some of the antheridia, 

 borne in the rosette at the summit of the plant. 

 Mount them in water, and study them under the 

 microscope. 



2. Describe the shape and other structural features 

 of the antheridia. What is their color? Compare 

 them with the antheridia of the fern. 



Do you find paraphyses associated with the anther- 

 idia? If so, describe them, and state how they 

 may be distinguished from the antheridia. 



4. If prepared slides are available, study longitudinal 

 sections through the tip of the male gametophyte, 

 observing the mode of attachment of the antheridia. 



5. With high power study the sperms (spermatozoids) 

 within the antheridia. 



6. In fresh specimens the sperms may be seen swim- 

 ming about in the water. If motile sperms are 

 present, endeavor to make out the number and 

 character of their organs of locomotion (cilia). Do 

 the cilia precede or follow as the sperm moves for- 

 ward? Do the motions of the sperm appear to be 

 purposeful or not? Give reasons for your answer. 



