64 COMMON LI VER IVOR T. 



distended with antherozoids, it will completely 

 fill the cavity and appear as a darker or lighter 

 spot in the tissues, according to the thickness of 

 the section, but if the antherozoids have escaped, 

 the collapsed antheridium remains, although it can 

 rarely be detected, and the cavity appears empty. 

 The antherozoids may sometimes be seen in 

 mass as a faint cloud escaping into the water of 

 the slide, especially when pressure is applied to 

 the cover-glass. 



g. Make a horizontal section from the upper part of 

 the head, after first removing a thin surface slice, 

 and again observe the cavities. 



h. Draw an uninjured antheridial branch, giving 

 prominence to the upper surface of the head. 



4. The head of the archegonial branch, consisting of a star- 

 shaped receptacle and circle of reproductive organs 

 beneath ; notice 

 a. The receptacle ; its general shape. 



i. The rays, with a longitudinal crease beneath ; 



their number, 

 ii. The cleft, which extends to the posterior side 



of the pedicel. 

 />. The reproductive organs forming groups alternating 



with the rays. 



c. Carefully separate one of the groups with a needle, 

 without detaching it, and notice 

 i. The border, perichsetium, surrounding it, and 



inclosing 



ii. The several young sporogonia. With a needle 

 remove the sporogonia to a slide without injur- 

 ing the perichsetium. Now observe that 

 iii. The two halves of the perichaetium are united 



