LIVERWORTS 



309 



476. The capsule (sporogonium). As a result of fertiliza- 

 tion the egg does not develop the marchantia plant again, but 

 develops into a new structure very different from the thallus 

 which bears the sexual organs. This is the capsule bearer 



Fig. 285. 

 Marchantia polymorpha, female plants bearing archegoniophores. 



(sporogonium}, which is peculiar to all the liverworts and mosses 

 as well. In Marchantia, as in most liverworts and mosses, it is 

 a stalked capsule. The capsule contains the spores, and in 

 Marchantia and many other liverworts the spores are mixed 

 with sterile cells in the form of long, slender, spirally marked cells 

 called elaters. These elaters are very sensitive to changes in the 

 humidity of the air, twisting and coiling in various ways with 

 slight changes in the humidity. This assists in pushing the 

 spores out of the capsule after it opens at the apex. Since the 



