About three leagues from Casapi, and close to the Huallaga, is the mountain called San Cristoval de Cocheros (Cuchero of Pavon and Poeppig), which rises from the low land at the junction of the two rivers to a height of about 1200 feet above them, and is the centre of the bark district of Huanuco. On the northern side Mr. Pritchett found abundance of C. micrantha, and some trees of C. Peruviana; but the latter species was much more rare. They both grow to a very large size, some of them being thirty inches in diameter and seventy feet in height. The trees of C. nitida were at a higher elevation.
During June and July, though it was the dry season, heavy rains continued to fall from day to day; but towards the end of July the weather broke up, and the sun began to make an impression on the solid banks of cloud which filled the valleys, and then it was that, during some portion of the day, the sun penetrated to the very underwood of the forest. In the first half of August there was fine weather, with only an occasional shower. The seeds on the chinchona-trees ripened rapidly in the sunshine, and Mr. Pritchett collected them by felling the trees—a labour which was performed by Indians, whom he hired from the coca estate of Casapi. Seven large trees were cut down daily, and denuded of their capsules, for a fortnight; the drying process being carried on at the estate, where every moment of sunshine was taken advantage of. On the 13th of August he started for the coast with his collection of seeds, and half a mule-load of young chinchona-plants, which were in perfect health when placed in the Wardian cases at Lima.
Mr. Pritchett reports that in the district around Cocheros, Casapi, and Carpis, the rocks are of crystalline formation, in many localities highly disintegrated, and composed of masses of hornblende, felspar, and mica. He remarks that felspar contains much potash, of which the chinchona-trees are said to require a large quantity for their full development; and, as felspar abounds in this region, he attributes the abundance and size of the chinchona-trees to this circumstance. He also reports that steatite, a silicate of magnesia and alumina, abounds in the vicinity of Huanuco.
He describes the climate as moist and warm, and says that the difference in the degree of moisture and warmth between the lower slopes where the C. micrantha flourishes, and the higher parts of the mountains inhabited by the C. nitida, is very striking, while on the lower slopes the soil is much deeper and richer.[372] He reports the elevation of Cocheros above the level of the sea to be about 4000 feet,[373] but he made no meteorological or other observations; and I think there can be no doubt that the elevation of that mountain is much greater than Mr. Pritchett supposes. I do not find any information on this point in Poeppig's travels; but the Huanuco region is quite a beaten track, and there are several accounts of it by modern travellers. Huanuco itself is 6300 feet above the sea;[374] the distance thence to the summit of the cuesta del Carpis, which is 8000 feet above the sea, is about twenty miles, and there is a descent on the other side into the valley of the Casapi of 2920 feet.[375] According to this account the village of Chinchao, in the Casapi valley, would have an elevation of about 5000 feet. From Chinchao to the foot of the Cocheros mountain is a distance of twenty-five miles down the Casapi valley,[376] a gentle descent, with numerous cottages and plantations on both sides of the road.[377] Thus the foot of the Cocheros mountain would be about 4500 feet above the sea, and its summit at least 6000 feet.
We shall not, therefore, be very far from the truth if we place the region of C. nitida on the Cocheros and Carpis mountains at from 6000 to 7000 feet above the sea, and of C. micrantha at from 4000 to 5000 feet.
Mr. Pritchett performed the portion of this important undertaking which I intrusted to him with promptitude and zeal. Time was a great object, and, by going direct from Lima to the best locality in the Huanuco chinchona region, he completed the necessary collection of plants and seeds, and returned to the coast in little more than three months.[378] This shows how essential a previous knowledge of the chinchona region, of the people, and of the language, was, without which the collector would probably lose much time, which is the same thing as spending much money, and eventually wander into a locality where only worthless species are found, as was the case with the Dutch agent.
Owing to the unavoidable abandonment of Mr. Spruce's intention of sending Dr. Taylor to collect seeds of C. Condaminea at Loxa, one portion of my scheme for introducing all the valuable species into India remained incomplete at the close of 1860. On my return from India, therefore, in May 1861, I obtained the sanction of the Secretary of State for India to take measures for obtaining a supply of seeds from the Loxa forests. Mr. Cross, the gardener who had so ably assisted Mr. Spruce, and shared his labours, after safely depositing the collection of seeds and plants in India, had returned to South America, attracted by the richness and variety of the flora of the Andes. Having acquired experience of the people and language, of the localities where chinchona-trees are found, and of the mode of travelling, during his former visit, he possessed the necessary qualifications; and, as Mr. Spruce was too ill to undertake the work, it was intrusted to Mr. Cross, who performed it with expedition and success. He is an excellent practical gardener, intelligent and persevering, ardently devoted to his profession, and thoroughly trustworthy.
On the 17th of September, 1861, Mr. Cross left Guayaquil in an open rowing boat, and landed at Santa Rosa, the port of the province of Loxa, whence he proceeded, by way of Zaruma, to the town of Loxa, which he reached on the 27th. He had to pass through dense swampy forests, over dangerous precipitous ridges of the Andes, in crossing one of which his mule slipped down a deep ravine and was dashed to pieces, and along barren lofty plains. He mentions that during the ascent to Zaruma he saw several "red-bark" trees growing at an elevation of eight or nine thousand feet.
On the 1st of October he left Loxa, and went to a long low ridge of hills, called the Sierra de Cajanuma, about eight miles to the southward, a locality which is mentioned by Humboldt, Bonpland, and Caldas, as the abode of the most valuable kinds of C. Condaminea. He came to an Indian hut on a little rounded eminence near the summit of the mountain, which, being far from public roads or other dwellings, seemed well suited for his head-quarters during the time that he was searching for seeds. For be it remembered that the Decree of May 1st, 1861, already mentioned, was in full force, and that he was running the risk of fine and imprisonment in performing this important service. The owner of the hut, who was an experienced bark-collector, allowed Mr. Cross to establish himself in a little shed at one end of it, which, although favourable for drying seeds, was so cold that he was sometimes compelled, during windy nights, to seek shelter in the bottom of a neighbouring ravine.
After many comparatively unsuccessful searches in the surrounding woods, he was one day passing along the bank of a steep ravine, and, happening to look over a projecting rock, he saw a number of fine young trees of the C. Condaminea on the steep slope beneath, some of which bore a few panicles of seeds, which, on examination, he found to be perfectly ripe. After this discovery he continued to search all the ravines in the vicinity from sunrise to sunset, some of which he had to descend by means of the trailing stems of a species of Passiflora, and in this way a good supply of seeds was collected. He reports that on the accessible slopes there are few chinchona-trees, owing partly to the annual burning, and partly to continual cropping of the young shoots by cattle. He describes the rocks, composed of micaceous schist and gneiss, as being, in many places, in a state of decomposition, and states that large portions are frequently tumbling down from the more elevated summits. The alluvial deposit in the ravines, where the C. Condaminea is found growing, is shallow, in many places not more than six inches in depth, and Mr. Cross often gathered seeds from trees which were growing in clefts of rock, where there was not a single ounce of soil to be found. He describes the C. Condaminea as a slender tree, from 20 to 30 feet in height,[379] and from 8 to 10 inches in diameter at the base; but he saw few trees of these dimensions, and the plants from which the bark of commerce is now taken are in general not more than 8 to 10 feet in height.[380] When the plants are cut down, three or four young shoots or suckers generally spring up, but this does not always happen, as some of the more industrious bark-collectors frequently pull up the roots, and bark them also. The bark is taken from the smallest twigs, and thus the annual growths are often taken, especially if they are strong. The plants are sometimes found growing in small clumps, and sometimes solitary, but always in dry situations.