At dawn the Indians found the marks of a jaguar on the beach close to the tent; and a huge snake wriggled through the fallen trees as we re-entered the forest. The brilliant colours and great variety of butterflies were very striking. I particularly noticed one, bright blue and crimson above, with the underside marked with a pattern, as if drawn by a crow-quill on a snow-white ground, edged with deep blue. After struggling through the forest for about a mile we came to the foot of the tremendous precipices, one on either side of the river, which Martinez called Ccasa-sani. That on our (the western) shore rises up perpendicularly from the water to a height which we estimated at 500 feet, ending in a rocky peak. Its sides are masses of bare polished rock, except in the rear, and in some crevices, where vegetation finds a foothold. Amongst other trees the paccay (Mimosa Inga), with its cottony fruit, was drooping over the bubbling waves. The river, surging furiously over and around huge masses of rock, dashed noisily on between the two precipices.
We had to ascend the western precipice of Ccasa-sani by a frightful kind of ladder, formed of ledges in the rock, or half-rotten branches of trees, here and there having to cross a yawning chasm on the fallen stems of tree-ferns rotting from age. Near the summit we had a glorious view of the forest-covered mountains, running up into sharp peaks, with graceful palms rising above the other trees on their crests, and standing out against the sky. Several Calisaya-trees were growing on the summit, with bunches of young capsules, in company with the leathery-leafed huaturu, and the Aceite de Maria (Elæagia Mariæ, Wedd.). The latter is a tree about thirty feet high, with bark covered with white lichens. Among the numerous ferns the most conspicuous was a very large Polypodium, called calaguala. Descending the rocks of Ccasa-sani, we had to continue the work of cutting our way through the forest, our passage being opposed by matted entanglements of bamboo, and a Panicum with blades, the edges of which cut like a penknife, called challi-challi. On many of the trees there were hornets'-nests, globes of mud fixed to the leaves, and covered with the insects. I was inadvertently going to touch one, which was attached to the back of a large fern-frond, when Martinez, with great dexterity, hurled the plants down the precipice, before the savage creatures were aware of their danger.
We were now in the midst of the chinchona region; and passed several trees of C. ovata (morada ordinaria) and C. micrantha (verde paltaya). There were also great quantities of a false chinchona, called by Martinez Carhua-carhua blanca. We passed through several large groves of this species, which appeared to be a Lasionema, but differed in several respects from the L. chinchonoides, mentioned by Dr. Weddell as growing in the Caravayan forests. The tree is very common near the banks of the river Tambopata, frequently with its boughs, large coarse leaves, and panicles of flowers, drooping over the water.[333]
The magnitude and variety of the trees of the forest were very striking; and the imposing character of the scenery, in these vast solitudes, was a source of constant enjoyment, and lightened the fatigues of the journey. Among the wonders of the forest there were enormous trees with great buttressed trunks, others sending down rope-like tendrils from the branches in every direction, the gigantic balsam-tree, the india-rubber tree, and many others. A list of the ferns or mosses, endless in the variety of their shape and size, would fill volumes. Of palms, also, there were many kinds. The tall chonta, with its hard serviceable wood; the slender beautiful chinilla (Euterpe?); the towering muruna (Iriartea?), with its roots shooting out in every direction from eight feet above the ground, and triangular-notched leaflets; the chaquisapa (Astrocaryum?), with its lofty stem thickly set with alternate rings of spines, and thorny leaves; the sumballu (Giulielma?), a beautiful palm with a slender stem covered with long sharp spines, numerous graceful leaves, and an edible fruit; and above all the sayal, the monarch of the palms of these forests, with a rather short thick stem, inner fibres of the stalks like black wool, but with enormous leaves growing rather erect from the stem to a length of at least forty feet—I should think they must be the largest leaves in the whole vegetable kingdom. Among the bright flowers there were crimson Melastomaceæ, called ccesuara, a scarlet Justitia, the Manetia coccinea, and many beautiful orchids in the branches of the trees.
At length, after a very hard day's work, we reached the mouth of the Yana-mayu[334] or Black river; and attempted to wade across the Tambopata, but found it too powerful. I was particularly anxious to effect this, as Martinez assured me that chinchona-trees were most abundant on the right or eastern bank. We, however, managed to get upon an island, near the left bank, and encamped for the night on a shingly beach. After sunset it came on to rain very heavily, and the waters foamed furiously around us in the inky darkness. The rain continued to pour down, and the waters to rise through the night, and I hourly expected the island to be submerged; but, fortunately, we escaped this danger, though the river came up to within a very few feet of the tent-door. I served out a dram of brandy to all hands.
In the morning of May 3rd I continued my attempts to cross the river, by stripping and trying the water for a ford at several points, with a long pole as a support. But the water was deep, much swollen, and very rapid; and, after having twice been as nearly as possible carried away by the fury of the stream, I was obliged unwillingly to give up the attempt for the present. I considered it prudent also to remove our encampment from the island, and to establish it on a narrow beach overshadowed by the forest, at the point where the muddy waters of the Yana-mayu unite with those of the Tambopata.
These arrangements having been made, we devoted the day to an examination of the adjacent forest. The spot on which we were encamped was about 4600 feet above the sea. Our tent was pitched close to the foaming torrent, and behind rose up the tall dark forests. In front were the steep green sides of the Yana-mayu ravine, while looking down the river the view was bounded by forest-covered mountains, surmounted by the lofty peak of Corimamani. On the actual banks of the river there were trees of C. micrantha, with large bunches of lovely and deliciously sweet white flowers; many carhua-carhua blancas; and a chinchonaceous tree, which Martinez called Huiñapu. The Huiñapu grows low down and near the banks of rivers. Its capsules are three inches long; and the veins of the leaves are a pale purple. Dr. Weddell tells me that he recollects gathering the leaves of the Huiñapu, and that he took it to be a variety of Cascarilla magnifolia.
We commenced the day's work in the forest on the south-west slopes of the Yana-mayu ravine, scrambling up the steep forest-covered declivity amongst palms, tree-ferns, bamboos, and trees with buttressed trunks of stupendous size. Here too were the vast leaves of the sayal palm. At a height of 400 feet above the river the Calisaya region commences; while in the lower belt, from the river banks to a height of 400 feet, the most abundant chinchonaceous plant is the Carhua-carhua grande (Cascarilla Carua, Wedd.), with very fragrant white flowers. I met with flowers and capsules together on the same tree, which is forty feet high, with a thick trunk, fine spreading branches, and masses of beautiful white flowers.
I found that the C. Calisaya region extended in a belt from 450 to 650 feet above the banks of the river; bamboos, large palms, C. micranthas, Huiñapus, Lasionemas, and the Cascarilla carua being found below that line, and other species of chinchonæ and chinchonaceous plants above it. We collected twenty-five Calisaya-plants, two of them fine strong seedlings, and the remainder root-shoots springing up from trees which had been cut down by cascarilleros in former times, but with good spreading roots of their own. The search was exceedingly hard work, scrambling through matted undergrowth, and up steep ascents, through masses of rotting vegetation.