BRYOPHYTES 293 



MUSCI (MOSSES) 



Habit. The mosses are leafy-stemmed plants and are hence 

 much more highly organized than the liverworts, which are their 

 nearest relatives. The stem of such a moss as Funaria is a 

 delicate structure with the leaves arranged spirally upon it. 

 The leaves are also very simple, being composed of a single 

 layer of chlorophyll-bearing cells, except in the central conduct- 

 ing strand, corresponding to a midrib, where the cells are 

 elongated and are two or more layers thick. 



The plants are anchored in the soil by delicate rhizoids, like 

 those of liverworts, which serve a similar function. Funaria, 

 like most mosses and liverworts, grows in clusters, a habit 

 which is an advantage in conserving moisture and in insuring 

 fertilization, since the male and female organs are borne on 

 separate plants and the clustering habit is necessary in order to 

 insure the proximity of male and female organs (Fig. 163). 



FUNARIA 



Gametophyte. The leafy moss plant just described is the game- 

 tophyte corresponding to the 'flat, leaflike plant body of Riccio- 

 carpus and the other liverworts. In Funaria the reproductive 

 organs (archegonia and antheridia) are borne in terminal repro- 

 ductive buds. 



The antheridia are borne in the form of open disks (Fig. 163, <?), 

 which are easily recognized by the brick-red color of the wall cells. 



The archegonia (Fig. 163,6) are produced in closed buds, which 

 are not easily distinguished from vegetative buds (Fig. 163, a). 



The antheridia and archegonia are almost identical in struc- 

 ture and function with those already described in Ricciocarpus, 

 so that no additional description of them is necessary. The 

 antheridia (Fig. 163, 6?, e) are accompanied by multicellular 

 hairs, called paraphyses, with enlarged terminal cells. 



Fertilization takes place, as in the liverworts, when the plants 

 are wet with rain or dew, which facilitates the opening of the 

 sex organs and the migration of the motile male gametes. 



