263 



raj, ft is not by mosses and lichens that vegeta- 

 tion in the countries ii^ar the tropics begins. 

 In the Canary islands, ^ Well as in Guinea, and 

 on the rpplsy coasts pf Peri^ the |r§| vegetables, 

 th^t prepare the mould for others, are the suc- 

 culent plants ; the leaves of which, provided 

 with an infinite number of orifices * and cuta- 

 neous vessels, deprive the ambient air of the 

 water it hplcls in solution. Fixed in the crevices 

 of volcatiic rpcks, they ferm, as it were, the first 

 layer of vegetable earth, with which the currents 

 of lithoid lava are clothed. Wherever these lavas 

 are scorified, and where they have a shining 

 surface, as in the basaltic mounds to the north 

 of Lanzerota^ the unfolding of vegetation is ex- 

 tremely slow, and many ages may roll away be- 

 fore shrubs can take root. 1% i£ only when lavas 

 are covered with tufa and ashes, the volcanic 

 islands lose that appearance of nudity which 

 marks their origin, and deck themselves with a 

 rich and brilliant vegetation. 



Ii| it's present state, the island of TenerifFe, the 

 Chimrfe^f pf the Gru§nches, exhibits five zones of 

 plants which we may distinguish by the names 



gion of the world where organised Jjeings totally differ from 

 those pf the rest of the old coiitinenj. 



*■ The bark pores qf IVIr. Decandolle, discpyere^ by GJei- 

 chen, and figured by JETedwig. 



f Of Chinerfe tjie Europeans have formed, by corruption, 

 Tehinerifle and Teneriffe. 



% I have partly sketched this picture of the vegetation of 



