~ abled to absorb and hold large quantities of 
ORDERS OF MOSSES 251 
phyte elongates it carries up the remains of the distended 
archegone as a little cap (calyptra). 
445. The spores, which are round or angular cells 
containing protoplasm, chloroplasts, oil-drops, ete., 
germinate quickly upon moist soil. Each spore pro- 
trudes a tubular filament, which develops into a conferva- 
like branching growth of green cells, called the “ pro- 
tonema.” Upon this buds are eventually produced from 
which spring up the leafy stems, thus completing the 
round of life. 
446. There are three orders of Mosses, including about 
12,600 species, as follows: (1) Black Mosses (Order An- 
DREAEALES), composed of a few small and rare mosses 
whose spore-cases open by four longitudinal slits; (2) 
Peat-mosses (Order SPHAGNALES), composed of large, 
soft and usually pale-colored plants, with clustered lat- 
eral 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 en- 
water, and for this reason they are exten- NY 
sively used for ‘‘ packing” in the transporta- 
tion of living plants. They all belong to Fre. 127.— 
i Sporophytes 
the genus Sphagnum, and their spore-cases (Andreaes and 
open by a circular lid, leaving an unguarded ot 
opening (without teeth). In this and the preceding 
order the stalk supporting the spore-case is an extension of 
the gametophyte stem and not a part of the sporophyte. 
447. (3) True Mosses (Order BryAues) include the 
great majority of the species of this class. They are 
usually bright green (in a few genera brownish), and in 
most instances live upon moist ground and rocks, or 
upon the bark of trees; in a comparatively small number 
