The eggs of the Yellow-Bird are four or five in number, white, with small spots of brown. After they are hatched, or even while sitting, the female often feigns lameness at the approach of a stranger, falling down near him and uttering pitiful cries, or perhaps fluttering along the ground. It is frequently annoyed by the intrusions of the Cow Troupial, which, building no nest of her own, makes use of the Yellow-Bird’s. The little builder being too weak to remove the incumbrance, generally builds a partition over it, thus preventing its being hatched. Nests have been found in which a second story has been raised in a similar manner. The Yellow-Bird is five inches long, and seven across the wings. Greenish yellow above; below, with crown and front golden, and orange spots on the breast; wings and tail brown, and the bill blue. The female is without any variation of color on the breast. [Illustration] BLACK-THROATED GREEN WARBLER. The Green Warbler arrives in Pennsylvania about the beginning of May, and in New England somewhat later. When observed for the first time in spring, it is generally alone, seated on a fruit-tree, and industriously searching for the small insects and larvæ which constitute his food. The species is somewhat rare, rarely more than a single pair, as it is asserted, being seen together, except in the fall, when scattered individuals collect to prepare for migration. Except during the period of incubation, they are not very shy of man, often permitting him to approach within a few feet. They are supposed to wander in summer as far north as Canada and Hudson’s Bay, but the larger portion remain in the Middle and New England States. Little is known of the precise time of building, since the habits of this songster are then retired. They appear to prefer low, dry situations, and build on bushes, not far from the ground. A nest examined by Nuttall contained four eggs, of a light flesh-colored tint, variegated with pale, purplish points of various sizes, interspersed with other large, brown or blackish spots. The outside was formed of fine strips of the inner bark of juniper, with another tough, fibrous bark, the whole lined with soft feathers, horse hair, and bent grass. The Green Warbler is four and a half inches in length, and seven across the wings. The chin and throat are black, with spots of the same color on the sides under the wings. The breast and belly are white, the wings and tail dusky, with some white, and the legs and feet pale brown. A bird called by Latham and Pennant the Yellow-Fronted Warbler, is probably but a variation of the same species. The song of the Green Warbler is a somewhat plaintive note, not unlike that of the Chicadee, uttered at short intervals, in a slow manner and with some variation. Owing to its solitary habits, it rarely mingles in the chorus of our summer groves. * * * * *