If the Southern Alps surpass the Kaikouras in beauty it is because of the contrast they show on their western flanks, between gaunt grandeur aloft, and the softest luxuriance below.  The forest climbs to the snow line, while the snow line descends as if to meet it.  So abrupt is the descent that the transition is like the change in a theatre-scene.  Especially striking is the transformation in the passage over the fine pass which leads through the dividing range between pastoral Canterbury and Westland.  At the top of Arthur’s Pass you are among the high Alps.  The road winds over huge boulders covered with lichen, or half hidden by koromiko, ferns, green moss, and stunted beeches, grey-bearded and wind-beaten.  Here and there among the stones are spread the large, smooth, oval leaves and white gold-bearing cups of the shepherd’s lily.  The glaciers, snowfields, and cliffs of Mount Rolleston lie on the left.  Everything drips with icy water.  Suddenly the saddle is passed and the road plunges down into a deep gulf.  It is the Otira Gorge.  Nothing elsewhere is very like it.  The coach zig-zags down at a gentle pace, like a great bird slowly wheeling downwards to settle on the earth.  In a few minutes it passes from an Alpine desert to the richness of the tropics.  At the bottom of the gorge is the river foaming among scarlet boulders—­scarlet because of the lichen which coats them.  On either side rise slopes which are sometimes almost, sometimes altogether precipices, covered, every inch of them, with thick vegetation.  High above these tower the bare crags and peaks which, as the eye gazes upwards, seem to bend inwards, as though a single shock of earthquake would make them meet and entomb the gorge beneath.  In autumn the steeps are gay with crimson cushion-like masses of rata flowers, or the white blooms of the ribbon-wood and koromiko.  Again and again waterfalls break through their leafy coverts; one falls on the road itself and sprinkles passengers with its spray.  In the throat of the gorge the coach rattles over two bridges thrown from cliff to cliff over the pale-green torrent.

In an hour comes the stage where lofty trees succeed giant mountains.  As the first grow higher the second diminish.  This is the land of ferns and mosses.  The air feels soft, slightly damp, and smells of moist leaves.  It is as different to the sharp dry air of the Canterbury ranges as velvet is to canvas; it soothes, and in hot weather relaxes.  The black birch with dark trunk, spreading branches, and light leaves, is now mingled with the queenly rimu, and the stiff, small-leaved, formal white pine.  Winding and hanging plants festoon everything, and everything is bearded with long streamers of moss, not grey but rich green and golden.  Always some river rushes along in sight or fills the ear with its noise.  Tree ferns begin to appear and grow taller and taller as the coach descends towards the sea, where in the evening the long journey ends.