LIVERWORTS. 



51 



Some of the species have a fontt resembling the 

 thallus of certain lichens, but of a 

 different colour; others, againj possess 

 a stem and leaves, but the latter 

 often assume strange outlines, accom- 

 panied by curious appendages and 

 stipules ; they are also more diapha- 

 nous than is usual with mosses, and 

 in colour more frequently assume a 

 purplish hue. Practically, with the 

 slightest experience, it is not difficult 

 to discriminate between them. 



The capsules, or spore-fruits in the 

 liverworts, are preceded by the pro- 

 duction of certain organs known as 

 archegonia and the antheridia : from 

 the former of these the capsule has 

 its origin ; while the antheridia, after 

 discharging their moving spiral fila- 

 ments, or the spcrmatozoids, die away 

 and disappear. In the frondose liver- 

 worts, such as Riccia, the archegonia 

 and antheridia are developed in the 

 cellular substance of the frond ; in 

 the leafy Jungcnnannicc they are found in the axils 



Fig. 9. — Capsule oi 

 Jiiugcrmannia, 



Fig. 10,— RiccIaJIuitaiis, a, nat. size ; b, imbedded spore case magnified. 



