144 ABOUT MOSSES AND LICHENS, [CHAP. 
plants which prepare a soil for the larger growths of 
oak and pine. 
The Scale-mosses (/ungermanniacee) closely re- 
semble the true mosses (J/uscz) at a_ superficial 
slance, but there are many points in which they 
differ when closely examined. In the Scale-mosses 
the sporangia (Sf, figs. 105, 107, 108), when ripe, split 
down the sides to allow the spores to escape, whilst 
Fic. 10% 
in Musct, as we have seen, they open at the top with 
a lid. This sporange rises from a calypira or hood 
(H, fig. 107), which is it- 
self enclosed in a calyz 
(cax, fig. 108). The spores 
are mixed up with curious 
spirally-twisted threads 
(elaters, fig.106). The cap- 
sule or sporange splits in- 
to four valves (V, fig. 105), 
which fall down and allow 
ee oe the dispersion of the spores. 
A few of these plants have 
no distinction between stem and leaf, but have a 
horizontal frond; but by far the greater number 
f_., 
