70 



Polytrichum commune L. 



Fig. 1. Two sporophytes enclosed within an apparenth- single calyptra. (5X) 

 Fig. 2. The sporophytes after removal of the calyptra; a, point at which the 



archegonia were torn by the elongating sporophytes. (5X) 

 Fig. 3. The calyptra split longitudinally, showing the two calyptra-proper 



contained within the outer hairy covering. (7X) 

 Fig. 4. A normal mature theca. (5X) 



