316 VIEWS, &C. PHYSIOGNOMY OF PLANTS. 



and here, in February, considerable masses of snow had 

 already fallen. 



The greater the heights at which the Mexican cone-bearing 

 trees begin to show themselves, the more singular is it, in the 

 island of Cuba (where, at the border of the tropical zone the 

 air, it is true, is cooled down during northerly winds to 46.6 

 Fahr.), to see another kind of fir (P. Occidentalis, Swartz), in 

 the plain itself, or on the gentle hills of the Isle of Pines, 

 growing among palms and mahogany trees (Sivietenia). Co- 

 lumbus even makes mention of a fir-wood (Pinal) in the 

 journal of his first voyage (Diario del 25 de Nov., 1492), at 

 Caya de Moya, north-east of Cuba. At Haiti, too (St. Domin- 

 go), the Pinus occidentalis near Cape Samana descends from 

 the mountains down to the very beach. The stems of these 

 firs, wafted by the gulf-stream to the two Azores, Graciosa 

 and Fayal, were among the principal signs that proclaimed 

 to the great discoverer the existence of unknown lands in the 

 West.* Is it positively ascertained that the Pinus occiden- 

 talis is entirely absent from Jamaica, notwithstanding its lofty 

 mountains? We may be permitted to inquire also, what 

 kind of Pinus grows on the eastern coast of Guatimala, since 

 the P. tenuifoiia (Benth.) is assuredly found only on the 

 mountains near Chinanta. 



On taking a general view of the species of plants which 

 form the upper tree-boundary in the northern hemisphere 

 from the frigid zone to the equator ; I find, for Lapland, accord- 

 ing to Wahlenberg, in the Sulitelma Mountains (lat. 68), not 

 acicular-leaved trees but birches (Betula alba), far above the 

 tipper limit of the Pinus sylvestris ; and for the temperate zone 

 I find in the Alps (lat. 45 45') Pinus picea (Du Hoi), advanced 

 beyond the birches. In the Pyrenees (lat. 42 30 7 ), we find 

 Pinus uncinata (Ram.) and P. sylvestris, var. rubra; within 

 the tropics in Mexico (lat. 19 20), Pinus Montezumae ex- 

 tends far beyond Alnus toluccensis, Quercus spicata, and Q. 

 crassipes ; and in the snow-crowned mountains of Quito, be- 

 neath the equator, Escallonia myrtilloides, Aralia avicennifolia, 

 and Drymis Winteri attain the highest limits. This last spe- 

 cies of tree, identical with the Drymis granatensis (Mut.), 

 and the Wintera aromatica of Murray, presents, as Dr. Joseph 

 Hooker has shown,f the most singular instance of the unin- 



* See my Examen crit., t. il pp. 246-259. 

 t Flora Antarctica, p. 229. 



