_Eggs._--The first set of eggs for the Nashville warbler seems to be always either 4 or 5; reported sets of 3 are probably incomplete or late sets. The eggs are ovate or short ovate and are only slightly lustrous. They are white or creamy white, speckled with shades of reddish brown, such as "chestnut" and "auburn," mixed with "light brownish drab." On some eggs the markings are fairly evenly scattered over the entire surface, but usually they are concentrated and form a wreath at the large end. Occasionally eggs are more boldly marked with spots and small blotches or short scrawls; others are nearly immaculate. The measurements of 50 eggs average 15.7 by 12.1 millimeters; the eggs showing the four extremes measure =17.2= by 12.7, 16.4 by =13.0=, =14.5= by 11.6, and 15.2 by =11.5= millimeters (Harris). _Young._--The period of incubation is said to be from 11 to 12 days, and probably the female does most of it, though Mr. Knight (1908) says: "One bird relieves the other on the nest and at times when the eggs are very near the hatching point I have seen the male bring insects to its mate on the nest. Possibly he may feed the female at earlier stages of incubation but I have not seen him do so. Both birds feed the young, giving them at first soft grubs and caterpillars, later on small beetles, flies and similar insects. * * * The young leave about the eleventh day after hatching." For a further study of the nesting behavior of the Nashville warbler, the reader is referred, to an excellent paper on the subject by Louise de Kiriline Lawrence (1948). _Plumages._--Dr. Dwight (1900) calls the natal down "sepia-brown," and describes the juvenal plumage of the Nashville warbler as follows: "Pileum hair-brown, back darker, olive tinged, and rump olive-green. Below, pale yellowish wood-brown, straw-yellow on abdomen and crissum. Wings and tail olive-brown broadly edged with bright olive-green, the median and greater coverts tipped with pale buff-yellow forming two wing bands. Lores and auriculars mouse-gray, the orbital ring pale buff." The sexes are alike in juvenal plumage. A postjuvenal molt occurs in July and August that involves the contour plumage and the wing coverts but not the rest of the wings or the tail. This produces a first winter plumage in which young birds become practically indistinguishable from adults in many cases, but the chestnut crown patch is generally smaller and more veiled in the younger male and is often lacking in the young female. Dr. Dwight (1900) says that the first nuptial plumage is "acquired by a partial prenuptial moult which involves chiefly the crown, sides of head and throat, but not the rest of the body plumage nor the wings and tail. The head becomes plumbeous gray, the edgings only half concealing the rich chestnut of the crown. The orbital ring is white and conspicuous. Wear is marked, bringing the gray of the nape into contrast with the greenish back, later exposing the chestnut of the crown."