SUPPLEMENT. 



The desire I had manifested to see the Archipelago of 

 the Canary Islands examined with respect to geology, and 

 natural philosophy, and the geography of plants, by tra- 

 vellers who could make a long stay there, has been lately- 

 realized. Mr. Leopold von Buch is now preparing an ex- 

 tensive work, the result of his laborious investigations on 

 Teneriffe, and the neighbouring Islands. To this great geo- 

 gnost, and to the researches of Mr. Smith, who has lately 

 fallen a victim to his zeal for the sciences in the expedition 

 on the river Congo, I am indebted for the Physical Map of 

 the Peak of Teneriffe. I have not hesitated to substitute more 

 accurate notions in the place of those communicated to me by- 

 Mr. Broussonnet (see vol. i, p. 260—271). Mr. Von Buch 

 distinguishes, 1st, the region of African forms, 0 — 200 toises $ 

 2d, the region of vines and grain, 200 — 430 toises 5 3d, 

 the region of the laurels, regio sylvatica, 430 — 680 toises 5 

 4th, the region of the pinus canadensis, 680 — 980 toises ; 

 5th, the region of the retama, spartium nubigenum, 980 — 1730 

 toises. The retama is found only at Teneriffe. It's infe- 

 rior limit is at 1000 toises. The mountains of all the other 

 islands, excepting Palma, are not high enough to enter this 

 limit, and the summit of the Pico de lo Muchachos in 

 Palma is composed only of naked and barren rocks. The 

 gramineous plants are very rare j and, as Mr. Von Buch ob- 

 serves, they do not form a particular zone. The plants 

 VOL. III. 2 P 



