142 ABOUT MOSSES AND LICHENS. [CHAP. 
Mosses have no stomata on their leaves or stem— 
though sometimes they occur upon the capsule—but 
it is evident that they absorb gases like other plants, 
This they probably effect through the walls of the 
cells composing their substance. 
Mosses are to be found everywhere. “The hard- 
beaten sides of footpaths, the loose crumbling matter 
at the base of rocks, the sand by the seashore, the 
rich moist banks of ditches, the grassy meadow, the. 
naked clay, the deep recesses of woods, the peaty soil 
of heaths and moors, the damp margins of pools or 
swamps, and wet boggy ground, have their own appro- 
priate species; not to mention the variety of mosses — 
which are truly aquatic, whether in rapid streams or 
quiet waters. The mud-capped walls which are so fre- 
quent in odlitic districts, produce always a multitude 
of species, some of them of rare occurrence elsewhere, 
while the little mounds made by ants are sometimes 
extremely productive. The Phasca seems to luxuri- 
