102 A MOSS PLANT. 



c. The detailed structure of a single antheridium. When 

 studying fresh material it is often possible to obtain 

 antheridia just ripe enough to allow the sperms to 

 escape at the time the antheridia are mounted in water. 

 If possible, obtain such a preparation, note the struc- 

 ture and behavior of the sperms. Note where and how 

 the antheridium opens. Draw. 



2. Archegonium. From female plants carefully remove the 

 leaves, and locate the archegonia. Observe: 



a. The attachment of the archegonia; the structure of the 

 paraphyses associated with the archegonia. With a 

 single archegonium well mounted observe: 



b. Its general form and structure, much as in liverworts; 

 the basal stalk; the swollen region, venter; the elon- 

 gated region, the neck, with a central row of neck canal 

 cells; within the venter a spherical cell, the egg; imme- 

 diately above the egg and below the neck canal cells 

 the -ventral canal cell. 



c. Draw. 



d. Try to find archegonia in which the egg is fertilized, 

 and determine how the sperm obtained entrance to the 



egg- 



e. In sections of old archegonia observe the early divisions 

 of the oospore as it is germinating. 



/. Draw. 



III. THE SPOROPHYTE AND ASEXUAL REPRODUCTION. 



1. Observe and draw a young sporophyte just emerging from 

 the leaves. 



2. Carefully remove the young sporophyte by pulling it out 

 of the stalk of the leafy shoot, and observe: 



a. The elongated stalk, the seta, at the lower end of which 

 is the sharpened foot that was imbedded within the 

 stalk of the leafy shoot. 



