ACROGENS— COVERED SPORES. 



35 



part, within the calyptra, develops into a spoi'e-case called Capsule, or 

 Urn (Fig. 30, c) ; its slender seta becomes a pedicel, which is often 

 thickened into an Apophysis (against the body), just beneath the 

 capsule. The capsule in many of the higher mosses has a separable 

 lid (L. operculum) ; this covers the mouth of 

 the capsule. The mouth is often surrounded 

 with a ring (L. annulus), or with a Peristome 

 consisting of one or two elegant borders of 

 teeth or hairs. 



62. The Charas (Figs. 31, 32) 

 are small submerged water-plants 

 of purely cellular tissue, and re- 

 sembling Algse. . But their man- 

 ner of growth is axiferous — axis- 

 bearing, with true root and stem. 

 They are leafless; the stems are 

 jointed, with branches whorled on 



Fig. 30. — Bypnum dendroicles: 6, 

 separate leaf magnified; c, capsule 

 with its pointed calyptra ; d, calyp- 

 tra and operculum removed, show- 

 ing peristome. 



a level with the joints. They are 

 nearly worthless to man, except 

 as a study. Some of them are 

 used for polishing plate, the stems 

 being calcareous; these are the 

 Water - lustres {Lustre d'eau). 

 Their flowers show a higher de- 

 velopment than many even of 

 the higher Acrogens (Fig. 32).* 

 The spore germinates without 

 developing a prothallus. 



Here the archegonium is contained 

 in a spore-case called a Nucule (Fig. 

 32) ; it has one large starchy spore. 

 The antheridium is called a Globule (Fig. 32, a). 



Fig. 31. — CharafragUU. 



* "The Order might perhaps have been introduced between Equise- 

 taceae and Marsileaceffi; but its true place is hard to determine." — A. 

 Gbay. 



