MU8GI. 



355 



the old arcliegonitini {h, Fig. 343, B and (7), 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- 

 nacem, howerer, 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 iv, ps, Fig. 344, B and 

 C). Essentially the same 

 structure is found in Andrce- 

 acem and PJiascacece. 



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 

 certain internal cells become 

 spore mother-cells, which di- 



Fig. 244. — DevelopmeEt of the pporo- 

 gonium of Sphagmmi acuiifolium. A, 

 longitudinal section of a female flower ; 

 ar, arcUegonla ; cfi. young perichaftial 

 leaves ; y, upper leaves ol" the shoot 

 -. -, • , o J i,j.„„ „„ii„ forminj; the perianth; B, longitudinal 



Vide into four daughter-cells, section of a young ^po^igoninm, sg ; 



flio anrn-pq Tbp PflTISulp wllpn 11'' ^'-°' ?' ^Porogomnm. enclosed in 

 tne Sporeb. xue t-apbuie, wiit,u thevaginula,*,- o.calypti-a; or, remains 



vi-na nnpns hir t.bp fallinp- ofF of "' old archegoninm ; ps. the pseudopo- 

 ripe, opens oy UIB idimig on. ui ^^^^ ^^ ^^.^^j^^^ ^^.j,j^ supports the 



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

 o. Lviiiiiiiu, \ ^ I rogonium is the columella and tlie 



i Svliaanacem and Bryacece), or curved row of spore mother-ceiis. c, 



^ -^ ^ ,.,,. Sphagnum squarrosum. sg, ripe sporo- 



in a few cases by splitting Ver- gonlum ; a, operculum ; c, torn calyp- 



. _, , J -t \ ■ J.1 ti'"; (7S, the elongated pseudopodium : 



tically [AnarCBaceCB) ; in tne c/i, p. rlchaitial leaves, ah magnified.— 



small order PJiascacece the cap- "' ° ™''^''' 

 sule is indehiscent, ;ind 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 graiiul9,ted 



