THE HIMALAYAN MOUNTAINS. 15 
a European one, a perfectly Alpine Flora. But as the decrease of temperature is 
gradual, so is the disappearance of Indian forms, and we continue for some time to meet 
plants with which we are familiar in every part of the plains, many of which indeed 
must originally have been derived from the bases of these mountains. Among these 
may be mentioned Butea frondosa, Carissa sepiaria, Justicia Adhatoda, Nyctanthes 
arbor tristis, Grislea tomentosa, Sterculia villosa, Kydia calycina, and Leea aspera. 
Nerium Oleander is found at the base of these mountains; and as in Syria and Barbary, 
along the banks of streams; Bassia butyracea, to which the shea tree of Bruce is 
probably allied, is indigenous in the neighbourhood of Almora, while the other 
species are found in warmer parts of India. The mangoe, though its fruit does not 
ripen, is found as high as four thousand feet, near Deyra, as well as at Nahn: and 
Gloriosa superba attains an equal elevation, but it only exposes its annual shoots 
during summer, while the subterranean situation of its tubers protects them from 
the great vicissitudes of temperature. 
An European, on his first arrival in a tropical country, is struck by the magnificent 
peculiarities of its vegetation ; but to one who has long resided in such a clime these 
become familiar, and his attention is more quickly excited by the re-appearance of 
forms with which he was familiar in his youth, and which characterize the more 
humble and verdant, but not less beautiful Flora of temperate climates. In pro- 
portion as we ascend these mountains, the plants of India disappear, and we are de- 
lighted at finding the increase in number and variety of those belonging to European 
genera. At first we see only a few straggling towards the plains, which in a more 
temperate climate would be their favourite resort; and it is not until we have attained 
a considerable elevation that, having apparently lost all traces of tropical vegetation, — 
we enter a forest of pines or oaks, and lofty rhododendrons, where none but Euro- 
pean forms are recognizable. The genera of which species descend to the lowest 
levels, are chiefly Clematis, Berberis, Viburnum, Hypericum, Rhus, Euonymus, Rubia, 
Geranium, and Viola. ' 7 
This disappearance of tropical forms is not so complete as would appear at first, 
on visiting the mountains in the spring or summer months ; for the southern slope of the 
Himalaya being within the full influence of the tropical rains, a peculiarity of atmos- 
pherical phenomena is induced, which favours the existence of a series of forms not 
otherwise to be expected in a climate of which the mean temperature is so low. - 
For the attainment of greater precision in our ideas respecting the peculiarities of 
vegetation as connected with the climate of successive elevations, it is proposed to divide 
the slope of the Himalaya into three several belts, and take separate notice of each. 
The first has been already considered, and may be supposed to extend to between four 
and five thousand feet of elevation, as several tropical perennials extend to the latter, 
and snow does not usually fall below the former. The second belt may be conceived to 
embrace the space between five and nine thousand feet of elevation, as the winter's snow 
is always melted from such elevations before the accession of the rainy season, and the 
upper 
