ZONES 01' VEGETATION. 
115 
adorned with vegetable clothing, what is the distribution 
oi plants on the steep declivity of the volcano, and what 
Island ” 8PCCt ° r I )h - ysi0 S U0ln 7 vegetation in the Canary 
In tlie northern part of the temperate zone, the crypto- 
gamous plants are the first that cover the stony crust of 
the globe, The lichens and mosses, that develope their 
o iage beneath the snows, arc succeeded by gramina and 
other phanerogamous plants. This order of vegetation 
(liners on the borders of the torrid zone, and in the 
countries between the tropics. Wc there find, it is true 
whatever some travellers may have asserted, not only on 
too mountains, but also in humid and shady places, almost 
on a level with the sea. Funaria, Dicrnnum, and Brvum • and 
these genera, among their numerous species, exhibit several 
which are common to Lapland, to the Peak of Tenerifte, 
•ind to the Blue Mountains of Jamaica.* Nevertheless, in 
general, it is not by mosses and lichens that vegetation 
"I the countries near the tropics begins. In tlio Canary 
islands, as well as in Guinea, and on the rocky coasts of 
eru, the first vegetation winch prepares the soil are the suc- 
culent plants; the leaves of which, provided with an infinite 
number of orifices! and cutaneous vessels, deprive the am- 
oient air of the water it holds in solution, fixed in the 
crevices of volcanic rocks, they form, as it were, that first 
layer of vegetable earth with which the currents of lithoid 
, 1 a™ clothed. Wherever these lavas are scorified, and 
" Here they have a shining surface, as in the basaltic mounds 
io the north oi Lancerota, the development of vegetation is 
extremdy slow, and many ages may pass away before shrubs 
; ii take root. It is only when lavas are covered with tufa 
• it ashes, that the volcanic islands, losing that appearance of 
n,ul i y -ir UC , h ,narks their orig!”, bedeck themselves in rich 
•uiu brilliant vegetation. 
confi’™", fjT w-17, fa0t "' aS , first ob5eived by M. Swarz. It was 
e'neci-ill ‘ • ^ illdenouw when he careful examined our lierbnK 
the m l- , ' ,< : i col 1 lec J Uon .« 1 eryptogamous plants, which we gathered on 
totally a; ir * he Andes, m a region of the world where organic life is 
orally different from that of the old world. 
° f M ' Deca ' K,olle ’ discovered by Gleichen, and 
I 2 
