The Lichens And Mosses, That Develop Their Foliage Beneath The Snows, Are Succeeded By Grumina And Other Phanerogamous Plants.

This order of vegetation differs on the borders of the torrid zone, and in the countries between the tropics.

We there find, it is true, whatever some travellers may have asserted, not only on the mountains, but also in humid and shady places, almost on a level with the sea, Funaria, Dicranum, and Bryum; and these genera, among their numerous species, exhibit several which are common to Lapland, to the Peak of Teneriffe, and to the Blue Mountains of Jamaica. (This extraordinary fact was first observed by M. Swarz. It was confirmed by M. Willdenouw when he carefully examined our herbals, especially the collection of cryptogamous plants, which we gathered on the tops of the Andes, in a region of the world where organic life is totally different from that of the old world.) Nevertheless, in general, it is not by mosses and lichens that vegetation in the countries near the tropics begins. In the Canary Islands, as well as in Guinea, and on the rocky coasts of Peru, the first vegetation which prepares the soil are the succulent plants; the leaves of which, provided with an infinite number of orifices* (* The pores corticaux of M. Decandolle, discovered by Gleichen, and figured by Hedwig.) and cutaneous vessels, deprive the ambient 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 lava are clothed.

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