THE GREAT GROUPS OF BRYOPHYTES 
313 
The air chambers are outlined on the surface as small 
rhombic areas (ctreolcv), each containing a single air pore. 
Peculiar reproductive bodies are also developed upon 
the dorsal surface of Marchantia for vegetative multiplica- 
FIG. 287. Marchantia polymorpha : 1, partial section through archegonial disk, show- 
ing archegonia with long necks, and venters containing eggs; 9, young archego- 
nitim showing axial row; 10, superficial view at later stage; 11, mature archego- 
nium, with axial row disorganized and leaving an open passage to the large egg; 
12, cross-section of venter; 13, cross-section of neck. After KNT. 
tion. Little cups (cupules) appear, and in them are numer- 
ous short-stalked bodies (gemma), which are round and 
flat (biscuit-shaped) and many-celled (Figs. 284, 285). The 
