326 PELLIA. 



the capsule; each line is bordered by somewhat narrow 

 clear cells, and along the line itself the cell- walls have no 

 thickenings. At the apex of the capsule, the four lines do 

 not all meet in a point, but are in pairs, each pair meeting 



Fig. 74. PELLIA. Part of the Capsule Wall, seen from inner side, showing a 

 portion of one of the Dehiscence Lines. 



at one end of a line over the apex ; hence two of the valves 

 are longer and have truncated tips, while the alternate two 

 are slightly shorter and have pointed tips but there is 

 some variation in the course of these dehiscence lines and 

 therefore in the form and size of the four valves. 



464, Further Studies on the Sporogonium. The 



development of the sporogonium may be traced by (1) 

 cutting longitudinal sections passing through cavities with 

 fertilised archegonia ; (2) dissecting out the entire sporo- 

 gonium when it is large enough ; (3) teasing out the 

 capsule in water and examining the capsule-wall, spores, 

 and elaters. The archegonia are fertilised in early 

 summer; the development of the sporogonium proceeds 

 during summer and autumn, and by late autumn all the 

 parts are differentiated. 



