ORGANS OF REPRODUCTION. 



379 



The archegonia or pistillidia, like the antheridia, are differently 

 arranged in different genera ; thus in Riccia they are imbedded 



Fig. 808. 



Fig. 809. 



Fig. 808. A portion of the thallus of Jfarchantia polymorpTia, showing an antheri- 



dial receptacle, r, supported on a stalk, s i^igr. 809. Antheridium of J/ar- 



chantia, discharging its small cellular contents. 



in the substance of the frond, while in Jnngermannia and Mar- 

 chantia {fig. 810) they are contained in receptacles, r, which are 

 elevated above the thallus on stalks, s. They are usually 

 small flask-shaped bodies, consisting of a cellular case or epi- 



Fig. 810. 



Fig. 81 : 



Fig. 810. A portion of 

 the thallus of Marchan- 

 tia polymorpha. r. Re- 

 ceptacle supported on a 

 stalk, s. On the under 

 surface of the recep- 

 tacle the pistillidia are 



imbedded Fig. 811. 



Archegonium of Mar- 

 chantia. b. Perigone, 

 open at its apex, and 

 surrounding an inner 

 cellular case or epigone, 

 c. Paraphyses. 



gone {fig. 811), having a canal in its upper . elongated por- 

 tion which leads to a cavity, at the bottom of which a single 



