The _archegoniophores_ are also elevated on stalks (Fig. 289).
Instead of a simple disk, the receptacle consists of nine or
more finger-like rays. Along the under side of the rays, between
delicately fringed curtains, peculiar flask-like bodies, or
_archegonia_, are situated. The archegonia are not visible to the
naked eye. They can be studied only with the microscope (x about
400). One of them much magnified is represented in Fig. 292. Its
principal parts are the long _neck_, _a_, and the rounded _venter_,
_b_, inclosing a large free cell—the egg-cell.
[Illustration: FIG. 293.—ARCHEGONIOPHORE, WITH SPOROGONIA, OF
MARCHANTIA.]
We have seen that the antheridium at maturity discharges its
sperm-cells. These swim about in the water provided by the dew and
rain. Some of them finally find their way to the archegonia and
egg-cells, the latter being fertilized, as pollen fertilizes the
ovules of higher plants.
After fertilization the egg-cell develops into the spore capsule
or _sporogonium_. The mature spore capsules may be seen in Fig.
293. They consist of an oval spore-case on a short stalk, the base
of which is imbedded in the tissue of the receptacle, from which
it derives the necessary nourishment for the development of the
sporogonium. At maturity the sporogonium is ruptured at the apex,
setting free the spherical spores together with numerous filaments
having spirally thickened walls (Fig. 294). These filaments are
called _elaters_. When drying, they exhibit rapid movements by means
of which the spores are scattered. The spores germinate and again
produce the thallus of marchantia.
[Illustration: FIG. 294.—SPORES AND ELATERS OF MARCHANTIA.]
MOSSES (Bryophyta)
[Illustration: FIG. 295.—POLYTRICHUM COMMUNE.
_f_, _f_, fertile plants, one on the left in fruit;
_m_, antheridial plant.]
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