The nests of these little creatures are very curious; they are built with great delicacy, but at the same time with much compactness and warmth. Wilson says that the nest of the ruby-throated humming-bird is generally fixed on the upper side of a horizontal branch, _not_ among the twigs. It is sometimes, however, attached to an old moss-grown trunk, and sometimes fastened on a strong stalk or weed in the garden. It seldom builds more than ten feet from the ground. The nest is about an inch in diameter and as much in depth. The outward coat is formed of small pieces of a species of bluish-gray lichen, that vegetates on old trees and fences, thickly glued with the saliva of the bird, giving firmness and consistency to the whole as well as keeping out moisture. Within this are thick, matted layers of the fine wings of certain flying seeds, closely laid together; and, lastly, the downy substance from the great mullein, and from the stalks of the common fern, lines the whole. The base of the nest is continued round the stem of the branch to which it closely adheres, and, when viewed from below, appears a mere mossy knot or accidental protuberance. The nest of one species in Guiana is principally composed of a spongy cellular substance, apparently similar to that of a fungus, of which some kinds of wasps build large habitations, suspended from the branches of trees, and an account is given of a nest of another species composed entirely of the down of some thistle; the seed is attached and is placed outwards, giving a jagged and prickly appearance to the outside. Latham describes the nest of the black humming-bird as made of cotton, entwined around the thorns and twigs of the citron-tree, and of so firm a texture as not to be easily broken by winds. The nest of the topaz-crested is about seven eighths of an inch in diameter, also made of cotton, stuck over with lichens on the outside and firmly fixed in the hanging cleft of some strong creeper by threads of a cottony substance, and very slender roots or tendrils, the whole lower part as if cemented by a thin coat of glue. It is probable that the greater number build their nests nearly in the same manner. Descriptions, however, are given of those built in different forms—one is suspended with the entrance downwards; another is of a lengthened form, composed of dry grass and slender roots and moss, and is not made so compactly. A person, who saw a bird building her nest, describes her manner of construction as very ingenious. “Bringing a pile of small grass, she commenced upon a little twig about a quarter of an inch in diameter, immediately below a large leaf, which entirely covered and concealed the nest from above, the height from the ground being about three feet. After the nest had received two or three of these grasses, she set herself in the centre, and putting her long slender beak over the outer edge, seemed to use it and her throat much in the same way as