MOSSES. 53 
range to rocks and soils of the same mineral 
character; their limits of distribution, and of the 
rocks and soils possessing such character, being 
identical. For instance, some are confinéd to 
limestone districts and chalk cliffs; a calcareous 
soil being indispensable to their existence. Others 
affect granite ; numerous species luxuriate in soil 
formed by the disintegration of micaceous schist. 
while not afew are found growing chiefly on sand- 
stone and clay. Some are found only on and near 
the sea-shore ; others are confined to the beds of 
streams and cliffs moistened by the spray of cas- 
cades, where, however impetuous the torrent may 
be, they cling tenaciously to the rocks, and form 
carpets of greenest verdure for the white glistening 
feet of the descending waters. Someare restricted 
exclusively to trees, whose trunks and boughs 
they clasp like emerald bracelets ; others lead a 
lonely, hermit-like existence, in the dim moist 
caves and crevices of rocks, where they are dis- 
covered only by the glistening of a stray ad- 
venturous sunbeam on the drops of dew trembling 
upon their shining golden-green leaves. One 
species has actually been found covering the half- 
decayed hat of a traveller who had perished in a 
storm on Mont St. Bernard. There is a very 
peculiar genus called Splachnum, whose members 
are only found on organic remains, on the blanched 
