THE TRUE MOSSES 519 
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$ Fic. 341, I1.—Umbrella-liverwort. Archigonio- 
: phores (3) bearing ripe ‘‘fruit’’ (sporophytes), 
the spore-cases of which are seen projecting 
beyond the curtains which protected them 
while young. Two of the spore-cases have 
burst showing the projecting elaters. (At- 
kinson.) 
FASTEST IRIS CLE Re NS ELTSAG 
extending into the capsule is a column of somewhat elongated cells, 
which is called the columella 1 (Fig. 345, c, c). Breathing-pores at 
the surface permit aération of the inner cells. 
Hepatice are plants producing archegonia upon a mostly prostrate 
and thalline gametophyte which may be variously lobed or branched 
and often resembles a flattened leafy moss, but which generally has 
well-contrasted upper and lower surfaces; and there is a sporangium 
generally dehiscing longitudinally and discharging its spores by means 
of intermingled thread-like elaters. There are about 3,000 species. 
190. The true mosses (Class Musci). The name ‘‘moss”’ 
is popularly given to any small, matted plant of soft texture 
‘Col-u-mel’la < L. diminutive of columna, a pillar. 
