Mr. Cross, the gardener whom I had engaged to assist Mr. Spruce, conveyed the fifteen Wardian cases, which I had previously sent to Guayaquil, up the river as far as Ventanas, and reached Limon on the 27th of July. In the mean while Mr. Spruce had carefully examined the chinchona forests, and visited all the bark-trees known to exist within reach of Limon. He found a good crop of capsules on many of them, which had already nearly reached their full size on the finest trees; on others, however, there were only very young capsules, and even a good many flowers, and not one of the late-flowering panicles produced ripe capsules. On the tree which bore most capsules they began to turn mouldy, the mould being not fungi, but rudimentary lichens, which, whilst it proved that the capsules were still alive and growing, proved also that they were exposed to an atmosphere almost constantly saturated with moisture. The _manchon_ or clump of "red-bark" trees at Limon lies nearly west from the peak of Chimborazo, and the river Chasuan rises on the northern shoulder of that mountain. The view from Limon takes in a vast extent of country, and the whole is unbroken forest, save towards the source of the Chasuan, where a lofty ridge rises above the region of arborescent vegetation, and is crowned by a small breadth of grassy _paramo_. The waters of the Chasuan run over a black or dull blue, shining, and very compact trachyte, over which, in the bottom of the valleys at Limon, there is a fine-grained ferruginous sandstone of a deep brown colour, in thick strata. The soil is a deep loamy alluvial deposit. The ridges on which the "red-bark" trees grow all deviate a little from an easterly and westerly direction, and the chinchonæ are far more abundant on the northern than on the southern slopes. The northern and eastern sides of the trees, too, had borne most fruit, and scarcely a capsule ripened on their southern and western sides. This is explained by the trees receiving most sun from the east and north, the mornings being generally clear and sunny in the summer, whilst the afternoons are foggy, and the sun's declination is northerly. Mr. Spruce also observed that the trees standing in open ground were far healthier and more luxuriant than those growing in the forest, where they are hemmed in and partially shaded by other trees; and he concludes, from this circumstance, that, though the "red-bark" tree may need shade whilst young and tender, it really requires (like most trees) plenty of air, light, and room wherein to develop its proportions. The lowest site of the "red-bark" tree at Limon is at an elevation of 2450 feet above the sea, and its highest limit is at an elevation of about 5000 feet. The trees nearest the plain are generally the largest, but those higher up have much thicker bark in proportion to their diameter.