For the chinchona forests in Ecuador I was so fortunate as to secure the services of Mr. Spruce, an excellent botanist and most intrepid explorer, who had been engaged for several years in the examination of the wilds of South America, and who was actually on the spot. Of his qualifications there could be no doubt, but I could scarcely have ventured to hope that the service which he undertook to perform would have been done so completely and so thoroughly, and would have been crowned with such undoubted success. It is perhaps invidious to make distinctions, where all have worked so zealously; but it is due to Mr. Spruce to say that by far the largest share of credit is due to him, and that his name must take the most prominent place in connection with the introduction of these precious plants into India. The region assigned to him was the most important, as it yielded the "red-bark" tree (_C. succirubra_), containing a larger percentage of febrifugal alkaloids than any other species; and I felt more sanguine of success in this quarter than in any other, because the country of the "red bark" was more accessible than any of the others, the forests being on the western slopes of the Andes, navigable rivers flowing through them to the Pacific Ocean, and there being, therefore, no necessity of conveying the plants over the snowy wilds of the cordilleras. I also requested Mr. Spruce to make an arrangement for procuring seeds of the valuable species from the forests of Loxa. For the forests of the Peruvian province of Huanuco I procured the services of Mr. Pritchett, a gentleman who had passed some years in South America, and who was well acquainted with that particular region. He was to collect plants and seeds of the species yielding grey bark. I myself undertook to explore the forests either of Caravaya or Bolivia, and to collect the _C. Calisaya_ and other important species of that more distant region. This part of the enterprise was surrounded by peculiar difficulties, arising from the jealousy of the people, habitual with the Bolivians, and recently excited in the minds of the Peruvians of Caravaya by the proceedings of M. Hasskarl, the Dutch agent; while the forests are far more inaccessible, and the journey to the coast is longer and more formidable. It was the opinion of Sir William Hooker, who gave me the advantage of his valuable advice, that a good practical working gardener should accompany both Mr. Spruce and myself, and he considered this an imperative requirement, in order that they might attend to the packing of the plants in the forests, their establishment in Wardian cases, and have charge of them during the voyage to India. I appointed Mr. Cross, at his recommendation, to act under the orders of Mr. Spruce; and Mr. Weir, who was recommended to me by Mr. Veitch, accompanied me to the chinchona forests of Caravaya.