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). 
The antheridia stand, on the mature shoot, by 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 Hepaticse 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 perichsetial 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 perichsetium, but only one perfects 
its sporogonium. The development of it 
occurs within the perichsetium ; the summit 
of the branch then begins to elongate ; it 
grows out into a long naked receptacle, and 
elevates the sporogonium contained in its 
calyptra high above the perichaetium. This 
so-called Pseudopodium must not, therefore, 
be confounded with the seta of other Mosses 
(see Andreaeaceae). At Fig. 263, jB, is shown 
in longitudinal section the nearly ripe spo- 
rogonium developed within the calyptra. 
Its lower part forms a thick base imbedded 
in 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 
Fig. 263.—^, B, sphagnum acutifoliu7n; A long^itudina 
section of the female flower, ar archegonia, ch perichcX'tial 
leaves still young, y the last perichajtial leaves; B longi- 
tudinal section of the sporogonium sg, the broad base of 
which remains in the vaginula v, while the capsule is sur- 
rounded by the calyptra c, upon this is the neck of the arche- 
goniunirtr, the Pseudopodium; C Sphag}iiivi squari'osu7n, 
ripe sporogonium sg with its lid d and ruptured calyptra c, qs 
the elongated Pseudopodium growing from the perichastium ch 
(after Schimper). 
