Mexico is the country of the _Morus tinctoria_ and the _Hæmatoxylon Campechianum_. These two trees furnish the dye-wood which forms so important an article of commerce: the first, under the name of the "yellow wood of Tampico" or "Tuspan;" the second, under that of "Campeachy wood." It is in the hottest and most humid parts of the southern provinces of this Republic that we meet, for the first time, with one of the most precious trees of the Equinoctial Zone, the Cacao-tree (_Theobroma cacao_), whose bruised and roasted seeds, mixed with variable amounts of sugar and starch, form the different kinds of Cocoa; or, sweetened and flavoured with vanilla or other substances, the article known as Chocolate. It is but a small tree, with large entire leaves, and clustered flowers growing from the sides of the old stems and branches. Its large pentagonal fruits vary from six to ten inches in length and three to five in breadth, and contain between fifty and a hundred seeds. The _Vanilla planifolia_, another Mexican native, famous for its succulent fruit, is a plant of the Orchidaceous order, which climbs about other trees in the manner of ivy. It is the only genus of the family which possesses any economical value. The delicate perfume of its fruit is due to the presence of benzoic acid, which forms in crystals upon the pod, if left undisturbed. * * * * * Already, in Central America, we encounter the first ranks, the vanguard, as it were, of those vast impenetrable forests which spread over the whole northern region of South America to the banks of the Amazon, and cover with dense foliage immense areas in Guiana and Brazil. If we would pause again to wonder at the Giants of the Vegetable Kingdom, we shall find many well worthy of our consideration. Such, for example, is the _Bertholletia excelsa_, a colossal Lecythidacean on the borders of the Orinoco, whose large fruits are known in Europe as "Brazil nuts," the seeds being enclosed in large woody vessels. The Sapucaya (_Lecythis ollaria_) is scarcely less abundant, and of immense height. Its fruit, popularly called "Monkey's Drinking-cups" (Cuyas de Macaco), consists of a cup-like vessel, with a circular hole at the top, in which a natural lid fits neatly. When the nuts are ripe this lid becomes loosened, and the heavy cup falls with a crash, scattering the nuts over the ground.