492 



temperate zones of both hemispheres, are en- 

 tirely wanting in the intermediary or equinoc- 

 tial region, as well in the plains as on the moun- 

 tains. A downy-leaved violet, which termin- 

 ates in some sort the zone of the phanerogamous 

 plants at Teneriffe, and which was long thought 

 peculiar to that island *, is seen three hundred 

 leagues farther north, near the snowy summit 

 of the Pyrennees. Gramina and cyperaceous 

 plants of Germany, Arabia, and Senegal, have 

 been recognized among those that were gather- 

 ed by Mr. Bonpland and myself on the cold 

 table-lands of Mexico, along the burning shores 

 of the Oroonoko, and in the southern hemi- 

 sphere on the Andes of Quito *f\ How can we 

 conceive the migrations of plants through coun- 

 tries of such a different climate, and which 

 are now covered by the ocean ? How have the 

 germs of organic beings, which resemble each 

 other in their appearance, and even in their 

 internal structure, unfolded themselves at un- 

 equal distances from the poles, and the surface 



* The viola cheiranthifolia, which Mr. Bonpland and I 

 have described, (see vol. i, p. 180 and 270) has been recog- 

 nized by Messrs. Kunth and Leopold von Buch among the 

 alpine plants, which Joseph de Jussieu brought from the 

 Pyrennees. 



f Cyperus mucronatus, poa eragrostis, festuca myurus, 

 andropogon avenaceus, lapago racemosa. See our Nov. Gen. 

 et Spec. Plant., vol. i, p. xxv, 158, 189, 111). 



