A series of eight nests now before me vary considerably in size, compactness, manner of construction, and in the materials used. The largest two measure 4 inches and 3-3/4 inches, respectively, in outside diameter, and the smallest ones measure from 2-3/4 to 3 inches. The inner diameter seems to be more constant, varying from 1-3/4 to 2 inches. All of my nests are shallow, hardly more than an inch deep internally in most cases. Some of them are fairly well made, but most of them are very flimsy and more or less transparent. The neatest nests have the sides and rims well built up with dry grass or weed stems of varying degrees of fineness and density. In some there is no grass, but the sides are well made of the very finest hemlock or larch twigs interwoven with fine, red, fruiting stems of mosses and many fine, black rootlets; they are often slightly decorated or camouflaged with a few weed blossoms or bits of wool or plant down. The lining of black rootlets is present in these and in all other nests of the magnolia warbler that I have seen; it seems to be characteristic of the species and will distinguish the nests from those of other warblers. This jet-black lining forms a fine background against which the handsome eggs are shown in striking contrast. Miss Stanwood gives in her notes the following account of nest building: "The birds fly with much jolly chattering through the trees and examine any nesting sites that appear desirable. The dainty female, after fitting her little body into many spaces among the twigs, finds one that is entirely adapted to her prospective domicile, and the birds proceed to fashion a basketlike frame of long, fine potentilla or cinquefoil runners, or culms of fine hay. These they fasten to the twigs and needles around the selected space with spiders' web, or tent caterpillar silk, leaving the long ends free. Around the top of the basketlike frame on the interior is laid a culm of hay in the form of an imperfect circle, which is secured to the frame with spiders' silk; many of the long ends are then turned down within, or crumpled into the space for the foundation of the superstructure. In the frame is fashioned the cradle, which is symmetrical and cup-shaped on the inside, but may be formed like the bowl of a spoon on the outside, according to the space which it is designed to fill. The preferred lining materials appear to be a jet-black, hair-like vegetable fibre, and horsehair, but on occasion, the dull orange setae of the birdwheat moss, or the brown fruit stems of maples are used for this purpose.