12 REPRODUCTIVE ORGANS OF MUSCI. 
In reviewing the fructification of the Marsileacez, we find 
that it differs from the Filices, Equisetaceze, and Lycopodiaceze 
in producing two distinct kinds of spores, and in the prothallium 
not forming a distinct expansion on the outside of the spore, as 
is the case with them, but being confluent with the spore. 
These characters show that the Marsileacez are closely allied 
to the Selaginellacez. 
6. Muscr or Mosstes.—The reproductive organs of this order 
are of two kinds, which are called antheridia (fig. 821), and 
archegonia or pistillidia (fig. 822). These are surrounded ~by 
leaves, called perichetial (fig. 824, f), which are usually of a 
different form and arrangement to those of the stem; and in 
some Mosses they have, in addition to the pericheetial leaves, 
another covering formed of three or six small leaves, of a very 
different appearance to them, termed perigonial, and constituting 
collectively a perigone. The antheridia are regarded as the male 
organs, and the archegonia or pistillidia as the female. 
Fre. 82. Fie. 822. 
aas} 
Fig. 821. Antheridium, a, of 
the Hair-moss _ (Polyt7i- 
chum), containing a num- 
ber of cells, c, in each of 
which there is a single an- 
therozoid. p. Paraphises, 
surrounding the antheri- 
dium. Fig. 822. Arche- 
gonium or pistillidium of a 
P Moss surrounded by pava- 
physes. 
eB. 
ee. 
ase 
=) 
o 
C2 
The antheridia and archegonia sometimes occur in the same 
perigone, in which case such Mosses have been termed herma- 
phrodite. More frequently, however, they are in different peri- 
gones, and then both kinds of reproductive organs may occur 
on the same plant, or on separate plants (figs. 9 and 10) ; in the 
former case we apply the term monecious, in the latter diwcious. 
The antheridium or male organ is a somewhat elliptical, more 
or less rounded or elongated cellular sac (fig. 821, a), which is 
filled at maturity with a number of minute cells, c, termed 
sperm-cells or mother-cells; in each of which there is a single 
spiral antherozoid. The antheridium opens by an irregular 
perforation at its apex, and thus discharges the sperm-cells with 
their antherozoids. Among the antheridia there are generally 
to be found slender cellular jointed threads (jig. 821, p), called 
paraphyses, which are probably nothing more than abortive 
antheridia, as they appear to perform no special function. 
The archegonia, like the antheridia, are also usually sur- 
rounded by filamentous cellular bodies, called paraphyses, which 
