FERTILIZATION 



67 



dry they lose their moisture and stand erect, thus forcing off 

 the operculum and permitting the spores to be carried away 

 by the currents of the air. 



FIG. 33. Musci. Four figures showing the sporophyte developing from 

 the gametophyte. Figure 4- A is the gametophy te ; 4--B-F, the sporophyte; 

 B, seta; C, capsule; D, epiphragm; E, operculum; F, calyptra. 



The spore-bearing tissue consists of a single layer of spore- 

 bearing cells arranged in a horse-shoe shaped mass. 



During its entire existence the sporophyte remains attached 



