The superb alligator-pear, more properly called percia gratissima; its first name given probably from its being indigenous to a country abounding in saurian reptiles, otherwise it is difficult to account for its inappropriate designation. It resembles in shape a large pear; but the interior of its rind is lined with a marrow-like substance of a yellowish colour, somewhat like butter, and used at the breakfast-table. Among other products is the tamarind, unrivalled either as regards beauty of foliage, brilliancy of blossoms, or the delicacy of its acidulous pulpy pods. In blossom the tree is a lovely object. Amid its feathery dark green foliage issue, in vast numbers, golden yellow branches with delicate flowers dazzling to the eye; while its fruits in a green state form a candied sweetmeat, or when ripe, and made into a decoction, a refreshing drink for fever-stricken patients. The inaja-palm, of various species, produces pellucid pods, from one to two feet in length, containing a row of beans--enveloped in white cottony pulp--grateful to the taste. The cocoa-palm, though at a distance from the coast, here flourishes in great perfection, adding to the splendour of the vegetation, with its glorious crown of monster leaves; while the plantain and banana are widely cultivated, a few plants of which are sufficient to supply a family with bread, vegetables, fruit, and preserves of various kinds. Humboldt observes that an area planted with plantains produces nearly twenty times as much food as the same space sown with corn. HUMMING-BIRDS. Amid this rich and varied vegetation, swarms of tiny and brilliant humming-birds flutter round the masses of highly-scented blossoms that perfume the air, and which might be mistaken by the stranger at first sight for some of the metallic-coloured beetles which dispute with them the nectar of the fragrant flowers, so brilliant is the lustre shed by both. As Gosse well remarks: "For that peculiar charm which resides in flashing light, combined with the most brilliant colours, the lustre of precious stones, there are no birds, no creatures, that can compare with the humming-birds, confined exclusively to America." These lovely little winged gems were to the Mexican and Peruvian Indians the very quintessence of beauty; and were called by various names, signifying "the rays of the sun," and the like. Fully four hundred distinct species of these winged gems are supposed to exist on the continent. TREES. Of the trees which have a wide range over the country, especially near the sea-coast, the lignum vitae is of great value. As from its hard nature it turns the edge of the best-tempered tools, it serves for the construction of wharves, as well as for the keels of ships,--the attacks of the teredo, or sea-worm, being futile upon the iron network of its fibres. It can remain under water for an indefinite period without rotting, and eventually becomes petrified.