This nest was quite characteristic of the species. Mr. Burns writes to me: "The nest, well hidden under a drift of dead forest leaves, never varied in composition in over a hundred examples examined by me, in partly skeletonized leaves and the characteristic reddish-brown lining of the flower stem of the hair moss." Every one of 50 nests found by Mr. Jackson was lined with these flower stems, and out of 34 nests reported by Dr. Samuel S. Dickey (1934) only one failed to contain this material, being lined with "black and gray horsehair." Samuel B. Ladd (1887) says that "sometimes fine grass and horse-hair are used as part of the lining." Dr. Chapman (1907) writes: "Nests taken by J. N. Clark at Saybrook, Connecticut (C. W. C.) are composed of decayed leaves and lined with stems of maple seeds." And there are probably a few other exceptions to the rule. Most observers agree that the worm-eating warbler prefers to nest on hillsides, either sloping or steep, but a number of nests have been found on the sides of deep, shady ravines, or on steep banks. Mr. Ladd (1887), however, states: "I have observed that these birds are not confined necessarily to hill-sides, as was heretofore supposed, as I have taken three sets on level ground and in rather open places, with little shade. The experience of Mr. Thomas H. Jackson of this place, who has taken ten nests this year, corroborates this fact." The nests are generally well concealed under a canopy of dead leaves, drifted by the wind and lodged against a maple, beech, dogwood, or ash sapling, or under hydrangea, laurel, or rhododendron bushes, or under some bunch of weeds or other obstruction. They are sometimes concealed under the roots of a tree or in a cavity in a bank where they are protected somewhat by fallen leaves. _Eggs._--The number of eggs laid by the worm-eating warbler varies from 3 to 6, but the set usually consists of 4 or 5. The eggs are ovate or short ovate, sometimes rather pointed, and only slightly glossy. The white ground color is speckled and spotted with shades of "russet," "vinaceous russet," and "auburn," intermingled with "light brownish drab" and "light vinaceous-drab." The markings, usually more thickly grouped at the large end, vary considerably, some eggs being boldly marked, while others are almost immaculate, or have just a few pale freckles of "light brownish drab" and "fawn." The measurements of 50 eggs average 17.4 by 13.6 millimeters; the eggs showing the four extremes measure =20.8= by =14.5=, and =15.5= by =12.7= millimeters (Harris). _Incubation._--Frank L. Burns (1905) writes: Incubation does not always commence immediately after completion of set, particularly if the season be young. It is probable that the second night witnesses the beginning of that period and, as far as my experience goes, I believe it is performed by the female alone. The male feeds her when covering newly hatched young.