Mosses and Lichens 



portion, the future spore-case and a lower portion, the future 

 foot and pedicel. 



Spore-case. At maturity is exserted, when it bursts some- 

 what irregularly to discharge its spores. 



Spores. Yellow, nearly smooth, mingled with twice-spiral 

 elaters. 



M. polymorpha. 



Gemmce. Receptacles bowl-shaped, on the upper-surface of 

 the thallus, and open at the top. Gemmae flat, upright cellular 

 bodies with two indentations at the sides, the growing points. 

 When gemmae germinate, the side toward the light develops 

 pores (stomata) for the admission of gases and for the egress 

 of gases and water vapour. If germination takes place on land, 

 the stomata are on the upper surface, but if in water lighted from 

 below, then they are on the under surface. Gemmae are a means 

 of reproducing plants. 



98 



