CHAPTER XXIII. 



LIVERWORTS CONTINUED. 



320. Sporogonium of marcliantia. — If we examine the plant 

 shown in fisr. i8i we shall see oval bodies which stand out be- 



Fig. iSi. 



Archegonial receptacles of marchantia bearing ripe sporogonia The 

 capsule of the sporogonium projects outside, while the stalk is attached to 

 the receptacle uudemeatll the curtain. In the left figure two of the 

 capsules have burst and the elaters and spores are escaping. 



tween the rays of the female receptacle, supported 

 on short stalks. These are the sporogonia, or 

 spore-cases. We judge at once that the\' are quite 

 different from those which we have studied in 

 riccia, since those were not stalked, ^^'e can see 

 that some of the spore-cases have opened, the wall 

 splitting down from the apex in several lines. This 

 is caused by the drying of the wall. These tooth- 

 K^' like divisions of the wall now curl backward, and 

 we can see the yellowish mass of the spores in slow motion, 



149 



