Among the hundreds of species of this very lovely tribe that swarm in the intertropical regions of South America, I will select one more for its surpassing beauty. It is the Bar-tailed Comet. We must look for it in the temperate and equable valley of the Desaguedero, which leads out of Lake Titiçaça, the largest sheet of water on the South American continent, and famous in Peruvian tradition, as the scene where Mango Capac and Mama Ocollo surprised the barbarous aborigines by their first appearance. On one of the charming islets of this quiet lake, the two august strangers were seen, clothed in garments; and, declaring that they were the children of the sun long prophesied of, proceeded to teach their simple subjects the arts of civilisation, and to establish a regular government. We must search for our tiny Comet, too, in the cultivated plains that surround the Cerro of Potosi, that singular cone sixteen thousand feet in height, which is wholly composed of silver, and which is estimated to have yielded, during the three hundred years that have elapsed since the Indian exposed the solid silver, when he accidentally tore up a shrub by the roots,--the sum of two hundred millions of pounds sterling. The districts around, and specially the environs of the town of Chuquisaca, are adorned with a profusion of gardens and orchards, in which many European trees and flowers grow, as well as those of the tropics, the climate possessing the charms of many regions. In the shrubberies of the city, and in the gardens of the Indian cottages, as well as the slopes of the surrounding mountains, where the native groves and forests grow undisturbed, the brilliant Bar-tail may be seen during the summer months; but, as soon as the chilling winds of April tell of coming winter, the charming visitor becomes scarce, and flitting northward finds in the forests of Lower Peru the mild and balmy air which he loves. When the trees are in blossom, and particularly the apple-trees, which have been introduced from Europe, and are largely cultivated in orchards, the males may be seen shooting in and out among the foliage, like glowing coals of fire, chasing each other with shrill chirpings, and with surprising perseverance and acrimony. The fields of maize, and pulse, and other leguminous plants which are cultivated in the plains, receive a fair share of his attention; and the nopâleries, or cactus-gardens, where the cochineal insect is reared for those most valuable crimson and scarlet dyes, which far outshine the vaunted productions of ancient Tyre. The blossom of the nopâl is itself one of the most splendid of flowers. It begins to open as the sun declines, and is in full expanse throughout the night, shedding a delicious fragrance, and offering its brimming goblet, filled with nectareous juice, to thousands of moths, and other crepuscular and nocturnal insects. When the moon is at the full in those cloudless nights whose loveliness is known only in the tropics, the