PHYSIOGNOMY OF PLANTS. 



(2132 E.) feet higher than the summit of Etna. Considerable 

 quantities of snow had fallen at this elevation in the month of Feb- 

 ruary. 



The more considerable the heights at which the Mexican Coniferse 

 are first met with, the more striking it appears to find, in the Island 

 of Cuba (where, indeed, on the borders of the torrid zone, northern 

 breezes sometimes cool the atmosphere down to 6| Reaumur, 46 

 .6 Fah.), another species of pine (P. occidentalis of Swartz), growing 

 in the plains or on the low hills of the Isle de Pinos, intermixed with 

 palms and mahogany trees (Swietenias). Columbus mentions a 

 small pine wood (Pinal) in the journal of his first voyage (Diario 

 del 25 de Nov. 1492), near Cayo de Moya, on the north-east of the 

 Island of Cuba. In Hayti, also, Pinus occidentalis descends from 

 the mountains to the sea-shore, near Cape Samana. The trunks of 

 these Pines, carried by the Grulf Stream jbo the Islands of Graciosa 

 and Fayal in the Azores, were among the chief indications from 

 which the great discoverer inferred the existence of unknown lands 

 to the West. (See my Examen crit., t. ii. p. 246 259.) Is -it 

 true that in Jamaica, notwithstanding the height of its mountains, 

 Pinus occidentalis is entirely wanting ? We may also ask what is 

 the species of Pinus found on the Eastern coast of Gautimala, as P. 

 tenuifolia (Benth.) probably belongs only to the mountains near 

 Chinanta ? 



If we cast a general glance on the species which form the upper 

 limits of arborescent vegetation in the Northern Hemisphere, from 

 the frigid zone to the Equator, we find, beginning with Lapland, 

 that, according to Wahlenberg, on the Sulitelma Mountain (lat. 

 68) it is not needle-trees which form the upper limit, but that 

 birches (Betula alba) extend much higher up than Pinus sylves- 

 tris; whilst in the . temperate zone, in the Alps (lat. 45f), Pinus 

 picea (Du Roi) advances highest, leaving the birches behind ; and in 

 the Pyrenees (lat. 42 ), Pinus uncinata (Ram.) and P. sylvestris 

 var. rubra: within the tropics, in lat. 19 .20, in Mexico, Pinus 

 Montezumse leaves far behind Alnus toluccensis, Quercus spicata, and 

 Q. crassipes; while in the snow mountains of Quito at the Equator, 

 Escallonia myrtilloides, Aralia avicennifolia, and Drymis winteri, 

 take the lead. The last-named tree, which is identical with Dry- 

 mis granatensis (Mut.) and Wintera aromatica (Murray), presents, 



