The nest of the Nashville is sometimes placed in comparatively low ground (that is, compared with its immediate surroundings), in soft green moss under an apology for a shrub, again in the side of a knoll covered with bird wheat (hair-cap) moss, or at other times in an open space in the woodlands under a stump, or tent-like mass of grass, or a clump of gray birch saplings. Around the top is usually woven a rim of coarse, soft, green moss; sometimes dried boulder fern or bracken is added. The side coming against the stump or overhanging moss lacks this foundation. The nest is lined with fine hay, if it abounds in the neighborhood, or pine needles if they are nearer at hand. Sometimes both are used. The red fruit stems of bird wheat moss and rabbit's hair are often employed. One or two birds have preferred some black, hair-like vegetable fibre for lining matter, one bird, horse hair. Ora W. Knight (1908) mentions a Maine nest that "was situated on the ground on an open wooded hillside at the foot of and between two small spruce trees, and was well imbedded in the moss. It measures in depth outside one and three-fourths inches, and inside one inch, the diameter outside was three and a quarter. * * * Nest building begins soon after the birds have arrived, and presumably the female does most of the work, while the male perches in a near by sapling and sings. * * * It takes from seven to nine days to build the nest, and on its completion an egg is laid each day until the set is completed. The eggs are usually laid between six and ten in the morning." A nest found by Henry Mousley (1918) near Hatley, Quebec, "was located at the foot of a spirea bush on a little mound, well sunk into the surrounding hair-cap moss (_Polytrichum commune_) and dwarf cornel or bunchberry (_Cornus canadensis_) of which the mound was carpeted. It was entirely hidden from sight and would never have been found had I not flushed the female from her set of five eggs." The only local nest of which we have any record was found by Owen Durfee (MS.) in Rehoboth, Mass., on June 2, 1892. It was only partially concealed among some very low bushes, grass, and other herbage near the foot of a small hill in neglected pasture land; the hill had a scattered growth of oak and beech saplings and had been tramped over by cattle. Frank A. Pitelka (1940a) found the Nashville warbler breeding in northeastern Illinois in "oak-maple-hickory climax woodland with semi-dense undergrowth, * * * with the stream cutting it and a semi-swampy, sedge-grass area with willow thickets and scattered elms and ashes." In northern Michigan, he found it "in spruce and cedar bogs and in sandy woods of aspen, birch, and Norway pine." Richard C. Harlow tells me that most of the nests he has found in New Brunswick, about 10, are very frail, but are lined with moose hair. He has found 7 nests in the mountains of Pennsylvania, where the normal lining is deer hair.