MOSSES. 69 
mountain ravines of New Zealand. Some of them 
grow in the bleakest spots in the world, and are 
to be found even at a higher altitude than the 
urn-mosses on the great mountain ranges of the 
globe. They form the faintest tint of green on 
the edges of glaciers, and on the bare storm- 
seamed ridges of the Alps and Andes, where not 
a tuft of moss or a trace of other vegetation can 
be seen; and this almost imperceptible film 
of verdure, when cleansed from the earth and 
moistened with water, presents under the micro- 
scope the most beautiful appearance. 
The peculiarities of these plants are so remark- 
able and interesting that they deserve more than 
a passing notice. As a rule, to which however 
there are a good many exceptions, they do not 
grow upright in tufts like the mosses, but have 
a flat, creeping, lichen-like habit, spreading over 
rocks and trees in closely-applied circles which 
radiate fromacommon centre. The whole typical 
plant is like a series or necklace of roundish flat 
imbricated scales, several of which branch from a 
common point in the middle. The leaves, unlike 
those of the mosses, are entirely destitute of a 
central nerve, for what is called the nervure in the 
membranous or leafy species is nothing more 
than the stalk itself, on the edges of which the 
leaves are fastened together in such a manner as 
