194 ELEMENTS OP STRUCTURAL BOTANY. 



special cells in the archegonia, and resulting in the 

 production of spores. 



343. Liverworts. Figs. 244 and 245 are representa- 

 tions of portions of a very common Liverwort, Marchantia 

 polymorpha. It may be found growing along the borders 

 of marshes and in wet places generally, often with inter- 

 mingled moss. It is of a deep green colour, and usually 



spreads over a consid- 

 erable extent of sur- 

 face. There is no ap- 

 pearance of leaves, the 

 plant-body lying flat 

 upon the surface upon 

 which it grows, and 

 putting forth root-hairs 

 on the under side. 

 Fig. 244. From the upper side 



arise peculiar stalked bodies of two sorts, as shown in 

 the figures ; the one consisting of flattened or slightly 

 convex disks, and the other being star-shaped. These 

 stalked bodies contain the reproductive organs. In 

 cavities .on the upper surface of the flattened disks are 

 produced the antheridia, from the cells of which are 

 liberated the antherozoids. On the under surface of the 

 rays of the star-shaped bodies are produced clusters of 

 flask-shaped archegonia, each with a germ-cell at its 

 base, and fertilization takes place in the manner already 

 described in the account of the Moss. As a result of 

 fertilization a capsule is developed which produces spores, 



Fig. 244. Portion of a Liverwort (Marchantia pnlymorpha), showing the 

 thallus and several stalked disks which bear the antheridia ; natural size. 

 (Thome,) 



