Mr. R. Owen, who found this bird breeding near San Geronimo, Guatemala, April 2 (Ibis, 1861, p. 67), states that the nest was built on the very crown of a high tree in the plain. It was made of small branches twisted together, and had a slight lining of coarse grass. It was shallow, and formed a mass of considerable size. The eggs were four in number, and are described as measuring 2.15 inches by 1.60, having a light red ground-color, and spotted and blotched all over with several shades of a darker red. Dr. Heermann found the nest of this species on the Medina River. It was built in an oak, and constructed of coarse twigs and lined with leaves and roots. It was quite recently finished, and contained no eggs. Mr. Dresser states that it breeds all over the country about San Antonio, building a large bulky nest of sticks, lined with small roots and grass, generally placed in a low mesquite or oak tree, and laying three or four roundish eggs, similar to those of the Honey Buzzard of Europe. He found several nests in April and through May, and was told by the _rancheros_ that its eggs are found as late as June. The nests found in the collection of Dr. Berlandier, of Matamoras, were coarse flat structures, composed of flags, reeds, and grass. The nests, though usually built on the tops of trees, are occasionally found, according to Darwin, on a low cliff, or even on a bush. The number of the eggs is rarely, if ever, more than three or four. Four eggs, taken by Dr. Berlandier near the Rio Grande, exhibit a maximum length of 2.44 inches; least length, 2.25; average, 2.41. The diameter of the smallest egg is 1.75 inches; that of the largest, 1.88; average, 1.81. These eggs not only present the great and unusual variation in their length of nearly eight per cent, but very striking and anomalous deviations from uniformity are also noticeable in their ground-color and markings. The ground-color varies from a nearly pure white to a very deep russet or tan-color, and the markings, though all of sepia-brown, differ greatly in their shades. In some, the ground-color is nearly pure white with a slight pinkish tinge, nearly unspotted at the smaller end, and only marked by a few light blotches of a sepia-brown. These markings increase both in size and frequency, and become of a deeper shade, as they are nearer the larger end, until they become almost black, and around this extremity they form a large confluent ring of blotches and dashes of a dark sepia. Others have a ground-color of light russet, or rather white with a very slight wash of russet, and are marked over the entire surface, in about equal proportion, with irregular lines and broad dashes of dark sepia. Again, in others the ground is of the deepest russet or tan-color, and is marked with deep blotches of a dark sepia, almost black. The eggs are much more oblong than those of most birds of prey, and in this respect also show their relation to the Vultures, rather than to the Hawks or Eagles.