BRYOPHYTE.S 



293 



They are divided into three groups : ( 1 ) Sphagnales, ( 2 ) Andrew- 

 ales and (3) Bryales. 



The Sphagnales were especially abundant during the car- 

 boniferous age and are largely responsible for the great beds of 

 coal. They are sometimes known as the peat or bog mosses and 

 are abundant in some localities, especially the swampy regions 





c' 



#dl 



Fig. 141. — Diagrammatic representation of the life cycle of Marchantia polymorpha; (a) 

 mature male plant; (a") maturefemale plant; (&') antheridium; (6") archegonium; (cO sperm; 

 (c") ovum; {d) oospore; (e) young sporophyte; (/') and ^/") spores; fff') and ig") young plants. 



of the higher altitudesu They are the characteristic types found 

 in cranberry bog's of the eastern and northern parts of the United 

 States. They were used extensively during the recent war for 

 dressing wounds. 



The Andreceales is a small order which we will not study. 



The order Bryales (Fig. 142) includes the most common and 

 widely distributed types of tlie present time. The gametophyte 

 body is a branching filament (protonema) which may be consid- 



