MUSCI. 759 
This order is frequently divided into two orders, namely, 
Marsileacex and Salviniaceer. 
Distribution and Numbers.—They are widely distributed, but 
are most abundant in temperate regions. Illustrative Genera :-— 
Pilularia, Zinn. ; Marsilea, Linn. There are about 40 species. 
Properties and Uses.—Of little importance. Marsilea Ma- 
cropus is known in Australia as the Nardoo plant. The sporo- 
carps contain starchy matter; these are pounded, and used in 
the same way as flour. 
Class II. Muscinez. 
Order 1. Musci, the Moss Order.—Character.—Cellular 
plants (figs. 9, 10, and 824), terrestrial or aquatic, with erect or 
creeping stems, and usually spirally imbricate leaves (jig. 1121). 
Reproductive organs of two kinds, called antheridia and arche- 
gonia (see pages 372-375). which are either placed on the same 
or on separate plants (figs. 9 and 10) ; hence these plants are 
monecious or diecious. The antheridium (fig. 821) is a more 
Fie. 1121. 
Fig. 1121. A portion of Andrea 
rupestris, much magnified. The 
stem is erect, with numerous 
small imbricate leaves. and a 
terminal sporangium, which is 
destitute of a seta. a. Sporan. 
gium after dehiscence, showing 
the 4 equal valves of which it 
is comvosed connected at the 
summit by the persistent oper- 
eulum. The valves are seen to 
have dehisced vertically. (After 
Hooker.) 
or less rounded, elliptic, or cylindrical sac, containing, when 
mature, a number of minute cells (sperm-cells), each of which 
encloses a spirally twisted filament (antherozoid). The arche- 
gonium is a flask-shaped body (fig. 822), which after fertili- 
sation developes an urn-shaped sporangium (figs. 823-825), 
with usually a central columella (fig. 829); the space between 
which and the walls of the sporangium being occupied by spores, 
without any elaters among them. The sporangiwm or capsule is 
commonly placed on a stalk (seta) (figs. 823, t, and 824, p), or 
occasionally it is sessile (fig. 1121), and at first is covered by a 
hood (calyptra) (figs. 824, ¢, and 825, ¢), beneath which is a kind 
3C 
