"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." One of the most remarkable botanical discoveries of modern days is that of a very curious and anomalous genus of plants, named by Dr. Hooker _Welwitschia_ in honor of its discoverer. Dr. Frederic Welwitsch, who first noticed this singular plant in a letter to Sir William Hooker, dated August, 1860. "I have been assured," says Dr. Hooker in his valuable memoir of this plant, "by those who remember it, that since the discovery of the _Rafflesia Arnoldii_, no vegetable production has excited so great an interest as the subject of the present memoir." We well remember this singular plant, having seen a specimen in the Kew Herbarium soon after its arrival in this country. The following is Dr. Hooker's account of its appearance and prominent characters: