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volcanic islands. The vegetation of Teneriffe is 

 unfavourable to the hypothesis, that nature in 

 new countries appears less subjected to constant 

 forms. Mr. Broussonet, who resided so long at 

 the Canaries, asserts, that the variable plants 

 are not more common there than in the south of 

 Europe. Ought it not to be presumed, that the 

 polymorphous species, which are so abundant in 

 the Isle of Bourbon, are owing rather to the na- 

 ture of the soil, and to the climate, than to the 

 newness of the vegetation ? 



I have now given a physical sketch of the 

 island of Teneriffe ; I have endeavoured to lay 

 down precise notions respecting the geological 

 constitution of the Canaries, the geography of 

 plants peculiar to this archipelago, and their 

 grouping at different heights above the level of 

 the ocean. Though I fatter myself with hav- 

 ing thrown some light on objects, which have 

 been so often discussed by other travellers, I 

 think nevertheless, that the natural history of 

 this archipelago still offers a vast field to inquiry. 

 The commanders in scientific expeditions, of 

 which England, France, Spain, Denmark, and 

 Russia have furnished such brilliant examples^ 

 have in general been too hasty in quitting the 

 Canaries. They have imagined, that these 

 islands have been sufficiently described, because 

 they are so nearly bordering on Europe ; they 

 have forgotten, that, in a geological point of view, 



