MUSCL 



355 



the old archegonium (h, Fig. 243, B and C), the lower end 

 penetrates into the tissues of the leafy axis ; the upper end 

 develops into a spore-case, while the remainder becomes a 

 filiform stalk (seta) of greater 

 or less length. In the Sphag- 

 nacece, however, the sporogo- 

 nium does not greatly elongate, 

 but, on the contrary, remains 

 quite short, while the end of 

 the leafy axis, soon after the fer- 

 tilization of the archegonium, 

 elongates into a slender leafless 

 stalk (pseudopodium), which 

 carries up the developing sporo- 

 gonium upon its upper expand- 

 ed end (v, ps, Fig. 244, B and 

 C}. Essentially the same 

 structure is found in Andrce- 

 acecB and Phascacece. 



464. The ripe sporogo- 

 nium (capsule, theca, or spore- 

 case) is of various shapes, but 

 generally more or less cylindri- 

 cal or globose ; it differs much 

 in its particular structure in 

 the different orders, but in all rig. 244. Development of the eporo- 



' goninm of Sphagnum aeutifoliiim. A, 



Certain internal Cells become longitudinal section of a female flower; 



, , ,, i . , ... ar, archegonia ; cfi, young pericha;tial 



Spore mother-Cells, WhlCll dl- leaves; y, upper leaves of the shoot 



vide into four daughter-cells, SSfof 16 per ' anth: A lomritudinal 



the spores. The capsule, when 

 ripe, opens by the falling off of 



a terminal lid (operculum) sporogonium. In the centre'of the spo- 



' rogonium is the columella and the 



(Sphaqnacece and Bryacece), or curved row of spore mother-ceils, c, 



.T Tii- Sphagnum tquarrosum. eg, ripe sporo- 



in a tew Cases by Splitting Ver- goninm ; d, operculum ; c, torn calyp- 



,1-1 / A j \ , tra ; gs, the elongated pseudopodium ; 



tlCally (Andraacece) ; in the ch, perichcetial leaves. All magnified. 



small order PhascacecB the cap- A 



sule is indehiscent, and the spores are set free only by its 

 decay or irregular rupture. The ripe spores are roundish 

 or more or less angled, and have a roughened or granulated 



