Leaving, then, the new world, let us cast a glance, in company with one of the greatest botanists of the day, at what we may call the tropical features of the Sikkim Himalayas. Though this region is not strictly speaking within the tropics, yet the vegetation at the base is of a tropical character. In this wonderful district the naturalist is able to wander through every zone of vegetation, from the "dense deep-green dripping forests" at the base of the Himalaya, formed of giant trees, as the Duabanga and Terminalia, with Cedrela and Gordonia Wallichii, mingled with innumerable shrubs and herbs, to the lichens and mosses of the regions of perpetual snow. The tropical vegetation of the Sikkim extends from Siligoree, a station on the verge of the Terai, "that low malarious belt which skirts the base of the Himalaya from the Sutlej to Brahma-Koond, in Upper Assam."
"Every feature," writes Dr. Hooker, "botanical, geological, and zoological, is new on entering this district. The change is sudden and immediate: sea and shore are hardly more conspicuously different; nor from the edge of the Terai to the limit of perpetual snow is any botanical region more clearly marked than this which is the commencement of Himalayan vegetation." The banks of the numerous tortuous streams are richly clothed with vines and climbing convolvuluses, with various kinds of Cucurbitaceae and Bignoniaceae. The district of the Terai is very pestilential, and, though fatal to Europeans, is inhabited by a race called the Mechis with impunity. As our traveller proceeded to the little bungalow of Punkabaree, about 1,800 feet in elevation, the bushy timber of the Terai was found to be replaced by giant forests, with large bamboos cresting the hills, numerous epiphytical orchids and ferns, with Hoya, Seitamineae, and similar types of the hottest and dampest climates. All around Punkabaree the hills rise steeply 5,000 or 6,000 feet; from the road at and a little above the bungalow the view is described by Dr. Hooker as superb and very instructive:
"Behind (or north) the Himalaya rise in steep confused masses. Below, the hill on which I stood, and the ranges as far as the eye can reach east and west, throw spurs on the plains of India. These are very thickly wooded, and enclose broad, dead-flat, hot, or damp valleys, apparently covered with a dense forest. Secondary spurs of clay and gravel, like that immediately below Punkabaree, rest on the bases of the mountains and seem to form an intermediate neutral ground between flat and mountainous India. The Terai district forms a very irregular belt, scantily clothed, and intersected by innumerable rivulets from the hills, which unite and divide again on the flat, till, emerging from the region of many trees, they enter the plains, following devious courses, which glisten like silver threads. The whole horizon is bounded by the sea-like expanse of the plains, which stretch away into the region of sunshine and fine weather, as one boundless flat. In the distance the courses of the Teesta and Cosi, the great drainers of the snowy Himalayas, and the recipients of innumerable smaller rills, are with difficulty traced at this the dry season. The ocean-like appearance of this southern view is even more conspicuous in the heavens than on the land, the clouds arranging themselves after a singularly sea-scape fashion. Endless strata run in parallel ribbons over the extreme horizon; above these scattered cumuli, also in horizontal lines, are dotted against a clear grey sky, which gradually, as the eye is lifted, passes into a deep cloudless blue vault, continuously clear to the zenith; there the cumuli, in white fleecy masses, again appear; till, in the northern celestial hemisphere, they thicken and assume the leaden hue of nimbi, discharging their moisture on the dark forest-clad hills around. The breezes are south-easterly, bringing that [{192}] vapor from the Indian ocean which is rarefied and suspended aloft over the heated plains, but condensed into a drizzle when it strikes the cooler flanks of the hills, and into heavy rain when it meets their still colder summits. Upon what a gigantic scale does nature here operate! Vapors raised from an ocean whose nearest shore is more than 400 miles distant are safely transported without the loss of one drop of water, to support the rank luxuriance of this far distant region. This and other offices fulfilled, the waste waters are returned by the Cosi and Teesta to the ocean, and again exhaled, exported, expended, recollected, and returned."
Many travellers complain of the annoyance caused to them by leeches. Legions of these pests abound in the water-courses and dense jungles of the Sikkim, and though their bite is painless, it is followed by considerable effusion of blood. "They puncture through thick worsted stockings, and even trousers; and when full roll in the form of a little soft ball into the bottom of the shoe, where their presence is hardly felt in walking."
A thousand feet higher, above the bungalow of Punkabaree, the vegetation is very rich, the prevalent timber being of enormous size, "and scaled by climbing Leguminosae, as Bauhinias and Robinias, which sometimes sheathe the trunks or span the forest with huge cables, joining tree to tree." Their trunks are also clothed with orchids; and still more beautifully with pothos, peppers, vines, and convolvuli.
"The beauty of the drapery of the pothos leaves (Scindapsus) is pre-eminent, whether for the graceful folds the foliage assumes or for the liveliness of its color. Of the more conspicuous smaller trees the wild banana is the most abundant; its crown of very beautiful foliage contrasting with the smaller-leaved plants amongst which it nestles; next comes a screwpine (Pandanus) with a straight stem and a tuft of leaves, each eight or ten feet long, waving on all sides. Araliaceae, with smooth or armed slender trunks, and Mappa-like Euphorbiaceae spread their long petioles horizontally forth, each terminated with an ample leaf some feet in diameter. Bamboo abounds everywhere; its dense tufts of culms, 100 feet and upward high, are as thick as a man's thigh at the base. Twenty or thirty species of ferns (including a tree fern) were luxuriant and handsome. Foliaceous lichens and a few mosses appeared at 2,000 feet. Such is the vegetation of the roads through the tropical forests of Outer Himalaya."
As we ascend about 2,000 feet higher, we find many plants of the temperate zone mingling with the tropical vegetation, amongst which "a very English-looking bramble," bearing a good yellow fruit, is the first to mark the change; next, mighty oaks with large lamellated cups and magnificent foliage succeed, till along the ridge of the mountain to Kursiong, at an elevation of about 4,800 feet, the change in the flora is complete. Here the vegetation recalls to mind home impressions: "the oak flowering, the birch bursting into leaf, the violet, Chrysosplenium, Stellaria and Arum, Vaccinium, wild strawberry, maple, geranium, bramble. A colder wind blew here; mosses and lichens carpeted the banks and roadsides; the birds and insects were very different from those below, and everything proclaimed the marked change in the vegetation." And yet even at this elevation we meet with forms of tropical plants, "pothos, bananas, palms, figs, pepper, numbers of epiphytal orchids, and similar genuine tropical genera."
The hill-station of Darjiling, the well-known sanitarium, where the health of Europeans is recruited by a temperate climate, is about 370 miles to the north of Calcutta. The ridge "varies in height from 6,500 to 7,500 feet above the level of the sea, 8,000 feet being the elevation at which the mean temperature most nearly coincides with that of London, viz., 50°." [{193}] The forests around Darjiling are composed principally of magnolias, oaks, laurels, with birch, alder, maple, holly. Dr. Hooker draws especial attention to the absence of Leguminosae, "the most prominent botanical feature in the vegetation of the region," which, he says, is too high for the tropical tribes of the warmer elevation, too low for the Alpines, and probably too moist for those of temperate regions; cool, equable, humid climates being generally unfavorable to the above-named order. "The supremacy of this temperate region consists in the infinite number of forest trees, in the absence (in the usual proportion, at any rate) of such common orders as Compositae, Leguminosae, Cruciferae and Ranunculaceae, and of grasses amongst Monocotyledons, and in the predominance of the rarer and more local families, as those of rhododendron, camellia, magnolia, ivy, cornel, honeysuckle, hydrangea, begonia, and epiphytic orchids."
We regret that want of space prevents us dwelling longer on the scenes of tropical Himalaya, so graphically described by Dr. Hooker. We will conclude this imperfect sketch with our traveller's description of the scenery along the banks of the great Rungeet, 6,000 feet below Darjiling:
"Leaving the forest, the path led along the river bank and over the great masses of rock which strewed its course. The beautiful India-rubber fig was common. . . . On the forest skirts, Hoya, parasitical Orchidiae, and ferns abounded; the Chaulmoogra, whose fruit is used to intoxicate fish, was very common, as was an immense mulberry-tree, that yields a milky juice and produces a long, green, sweet fruit. Large fish, chiefly cyprinoid, were abundant in the beautifully clear water of the river. But by far the most striking feature consisted in the amazing quantity of superb butterflies, large tropical swallow-tails, black, with scarlet or yellow eyes on their wings. They were seen everywhere, sailing majestically through the still, hot air, or fluttering from one scorching rock to another, and especially loving to settle on the damp sand of the river; where they sat by thousands, with erect wings, balancing themselves with a rocking motion, as their heavy sails inclined them to one side or the other, resembling a crowded fleet of yachts on a calm day. Such an entomological display cannot be surpassed. Cicindelae and the great Cicadeae were everywhere lighting on the ground, when they uttered a short sharp creaking sound, and anon disappeared as if by magic. Beautiful whip-snakes were gleaming in the sun; they hold on by a few coils of the tall round a twig, the greater part of their body stretched out horizontally, occasionally retracting and darting an unerring aim at some insect. The narrowness of the gorge, and the excessive steepness of the bounding hills, prevented any view except of the opposite mountain-face, which was one dense forest, in which the wild banana was conspicuous."