222 



BOTANY 



FIG. 183. Notothylas orbicularis. Apex of thallus and archegonia (x 600) ; x, the 



apical cell. 



FIG. 184. Notothylas orbicularis. Development of the antheridium. 7), cross- 

 section, the others longitudinal sections. A-l), X GOO. E, X 300. 



