4H 



A TEXTBOOK OF THEORETICAL BOTANY 



of the capsule is made up of several layers of cells, also with 



chloroplasts, and is covered by a 

 well-defined epidermis, whose cells 

 are more strongly thickened on their 

 outer walls. 



Annulus 



Spores 



Apophysis 



Operculum 

 Peristome 



Amphithecium 



Columella 



Fig. 407. — Mniittu hornum. Median longi- 

 tudinal section through mature sporo- 

 gonium. 



Fig. 408. — Mnium cuspidatitw. Stoma on 

 apophysis in cross section and in surface 

 view. {After Haberlandt.) 



Stomatal slit 



Fig. 409. — Mnium liornum. Stoma froni external surface, 

 showing slit. 



The spore walls are brown and highly cuticularized, and often covered 

 on the outside with tiny warts. The spores arise, as in the case of Pellia, 



