SCENERY OF THE ANDES. 
39 
masses of trachytic rock, which here and 
there rise above the surface of the turf 
clad soil, none but plants of the lowest or¬ 
ganization can thrive; the tribe of liverworts 
which the atmosphere now of greatly dimin¬ 
ished density and containing little carbonic 
acid supports but sparingly: Parmelias, 
Lecideas, and Leprarias, with their many- 
coloured sporules, form the flora of this 
inhospitable zone. Patches or islets of 
lately fallen snow now begin to cover the 
last efforts of vegetable life, and then sharply 
defined, the line of eternal ice begins.”* 
The botany of the ancient earth does not 
display to us such a varied picture as that 
just exhibited. 
Although the researches of geologists are 
too limited to enable us to conclude with 
certainty on the extent of former vegetation, 
yet they are sufficient to enable us to state 
that there was greater uniformity in the con¬ 
ditions of former life, and more monotony 
in the character and aspect of the foliage. 
* Kosmos. 
