The downy young are beautiful little things, silvery white beneath, bright, rich ocherous above, variegated with black and dots of white. The general color above lacks the grayness of the similar age of _maritimus_. The white dots are interesting under the microscope. They are composed of a bunch of highly specialized down, in which the radii near the tip are crowded and colorless. As they grow older the first feathers appear on the sides of the breast, on the back and scapulars; then the primaries and larger wing coverts appear. The feathering continues until the breast and under parts are covered, when the tail appears. At this time there are no feathers on the rump or on the head or neck. In the next stage feathers have appeared on the occiput and on the auriculars and are also extending up the neck. At the same time the tips of the back feathers have become somewhat worn, so that the colored margins are narrower and the black more prominent. The wing coverts are also to some extent worn on their tips. When the bill is an inch long the down has nearly all disappeared, and when it has entirely gone the birds appear in small flocks on the beaches, the young generally keeping together. Then another change takes place, for the entire plumage now gives way to another, that in which the bird passes the winter. A few late July, immature birds show the beginning, for No. 118832, im. [male], July 29, has a few new feathers on the middle of the back and on the scapulars. They soon extend all over the back, so that specimens collected up to August 10 have many of the new whitish feathers on that region.