102 GENERAL BIOLOGY 



Examine some of the sporangia, and work out the follow- 

 ing parts, using the high power where necessary: 



(a) The Stalk or Pedicle. What is its shape and structure ? 

 (6) The Capsule which contains the spores. What is 

 its shape and structure? Note especially the annulus, 

 or crescent of thickened marginal cells forming a crest 

 or ridge. Is it continuous about the entire capsule? 

 Where is it most developed? Is the capsule more 

 fragile at one point than another? Examine several 

 capsules in demonstrating this point. Observe the 

 size, shape and arrangement of the lateral or parietal 

 cells of the capsule. i 



(c) The Spores. Rupture sporangia by pressure of the 

 cover glass and examine the spores. What is their 

 color and shape? 



Make drawings which illustrate the various struc- 

 tures studied above. 



2. The Prothallium (Gametophyte). Study prothallia in 

 their normal growing condition if possible. What is their 

 general appearance, color and shape? Carefully isolate a 

 single specimen as directed by the instructor and proceed 

 to work out its distinctive morphological features. Is it 

 differentiated into an upper and a lower surface? If so, 

 what are the distinguishing characteristics? Has the plant 

 rootlike organs or rhizoids? \Vhere are they located and 

 what is then- probable function? 



Carefully examine the lower surface of the prothallium 

 for the presence of the following organs: 



(a) Antheridia. These are small somewhat spherical 

 bodies usually located among the bases of the rhizoids. 

 They correspond to the male sexual organs and may 

 contain small coiled antherozoids, the male sex cells. 



