THE BRYOPHYTA: MUSCI, THE MOSSES 



Operculum 3ii^^M^V Calyptra 



Amphithecium 



445 



spore sac 



Columella 



Foot 





Pseudopodium 



Fig. 435. — Sphagnum sp. Longitudinal section of mature sporogonium 

 showing dome-shaped mass of spores and elongated pseudopodium. 



SPORE 



LAYER 



OPERCULUM 



COLUMELLA 



OPEN END 



PSEUDOPODIUM 



A B 



Fig. 436. — Sphagnum. A to D, Stages in dehiscence of sporogonium and discharge 



of spores. (After Naivaschin.) 



For a plant which inhabits such wet locaUties Sphagnum is pecuHar in 

 having many features which only seem explicable as water-saving devices, 



