Musci. ' 379 



The archegonia and antheridia of Sphagnum arise on the fascicled branches, as long 

 as they are still near the summit of the primary stem and belong to the terminal tuft. 

 The time of bearing them is mostly in autumn and winter, but is not exclusively confined 



■ to these periods. The antheridia and archegonia are always distributed on different 



[branches, sometimes even on different plants, and in this case the male and female plants 

 form large distinct patches. When the primary stem does not continue to grow during 

 the development of the sporogonia in consequence of dry weather, these are to be found 



[on the branches of the terminal tuft at a later period ; but when the supply of water is 



[great and vigorous increase of length takes place, the fertile branches become separated 

 from one another, and are subsequently found lower down on the stem ; the sporogonia 

 and older male branches are thus removed to a distance from the summit, although 



[at the time of their development they stand near it. The branches which bear the 

 antheridia are generally conspicuous externally by their imbricated leaves forming beauti- 

 ful densely crowded orthostichies or spiral parastichies ; the leaves are generally yellow, 



[bright red, or especially dark green, and can hence be easily recognised (Fig/ 260, a a). 



iThe antheridia stand, on the mature shoot, h}' the side of the leaves ; they are never 



[terminal, and are found only in the middle 



■part of the male branch, one standing beside 

 each leaf; the male branch may therefore 



[continue to grow at the summit, and be- 



|come an ordinary flagellate branch. This 

 position of the antheridia, and still more 

 their roundish form and long pedicel, causes 

 the Sphagnaceae to resemble some Junger- 

 mannieae; the mode in which they open 

 (Fig. 262) recalls the Hepaticae even more 

 than the true Mosses. The archegonia 

 arise at the blunt end of the female branch, 

 the upper leaves of which form a bud-like 

 envelope; but the young perichaetial leaves 

 are still contained within this at the time 

 of fertilisation, although they afterwards 



.become further developed. The archegonia 



[are exactly like those of the rest of the 

 Mosses; several of them are usually fertilised 

 in one perichaetium, but only one perfects 

 its sporogonium. The development of it 

 occurs within the perichaetium ; the summit 

 of the branch then begins to elongate ; it 



tgrows out into a long naked receptacle, and 



televates the sporogonium contained in its 



|Calyptra high above the perichaetium. This 



tso-called Pseudopodium must not, therefore, 

 be confounded with the seta of other Mosses 

 (see Andreaeaceae). At Fig. 263, J5, is shown 

 in longitudinal section the nearly ripe spo- 

 rogonium developed within the calyptra. 



' Its lower part forms a thick base imbedded 



Jn the end of the pseudopodium which is transformed into the vaginula. The spore- 

 mother-cells are formed from a cap-shaped layer of cells beneath the apex of the 

 spherical theca; the part of the inner tissue which is found beneath it forms a low 

 nearly hemispherical column, which is in this case also termed the columella, although 

 it is distinguished from the columella of true Mosses by not reaching to the apex of the 

 theca. The mode of the formation of the spores from the mother-cells resembles that 



tifoliujn; A lon^itudina 



Fig. 263.—^, B, Sphagtiunt 

 section of the female flower, ar archegonia, ch perich?etial 

 leaves still young-, y the last perichsetial leaves ; B longi- 

 tudinal section of the sporogonium sg, the broad base of 

 which jg-' remains in the vaginula v, while the capsule is sur- 

 rounded by the calyptra c, upon this is the neck of the arche- 

 goniumrtr,/j the pseudopodium; C Sphag;}uim squarrosum, 

 ripe sporogonium sg with its lid d and ruptured calyptra c, qs 

 the elongated pseudopodium growing from the perichaetium ck 

 (after Schimper). 



