BRYOPHYTA. 191 
different parts of the same plant (monecious) or even 
upon different plants (diccious). 
898. The act of fertilization requires water; but as the 
antherozoids are so minute, a dew-drop may be sufficient. 
The antherozoids swim to the open neck of the archegone, 
down which they pass to the germ-cell. The germ-celi 
now begins to divide rapidly, growing upward and eventu- 
ally forming the spore-fruit. In most mosses the spore- 
fruit is narrow and elongated below, forming a stalk which 
supports its upper spore-bearing part (the capsule or spore- 
case). 
899. The spore-case, when ripe, usually opens by a lid 
which falls off, leaving a round opening, generally fringed 
with many teeth (Fig. 106, Gand H). In most species, as the 
spore-fruit elongates it carries up the remains of the dis- 
tended archegone as a little cap (calyptra) (Fig. 106, Z, c). 
400. The spores, which are round or angular cells con- 
taining protoplasm, chlorophyll-granules, oil-drops, etc., 
germinate quickly upon moist soil. Tach spore protrudes 
a tubular filament, which develops into a conferva-like 
branching growth of green cells, called the protonema (Fig. 
107). Upon this there finally are produced buds from 
which spring up the leafy stems, thus completing the round 
of life. 
401. There are four orders of Mosses, as follows: (1) the 
Peat-mosses (Order Sphagnacee), composed of large, soft, 
and usually pale-colored plants, with clustered lateral 
branches; they inhabit bogs and swampy places, where 
they form dense moist cushions, often of great extent. On 
account of peculiarities in the structure of their leaves they 
are enabled to absorb and hold large quantities of water, 
and for this reason they are extensively used for “ packing” 
