The period of incubation extends over from thirty to thirty-five days. When the young makes its

appearance it rather resembles a ball of greyish black wool than a bird; its coat of down soon disappears; its growth is rapid; and in about a month it is completely fledged.

THE COMMON OR FOOLISH GUILLEMOT.

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THE COMMON OR FOOLISH GUILLEMOT (Uria troile). ONE-FOURTH NATURAL SIZE.

The Common or Foolish Guillemot (Uria troile), in its nuptial garb, is bright brown upon the back and on the fore parts of the neck; the points of the feathers upon the upper arm are white, forming a conspicuous band. The under surface is white; the sides are striped with brown. In the winter dress both the fore part of throat and hinder part of cheek are white. The eye is brown, beak black, and foot grey. This species is seventeen inches and a half long, and from twenty-seven to twenty-eight broad; the wing measures three inches and the tail two and a half. The Common Guillemots are to be seen around the British coast at all seasons of the year. About the beginning of May they assemble in their breeding-places on the rocks, which are also frequented by other birds for the same purpose. "From the numbers that congregate," observes Yarrell, "and the bustle apparent amongst them, confusion of interests might be expected; but, on the contrary, it will be found that the Guillemots occupy one station, or line of ledges on the rocks, the Razor-bills another, the Puffins a third, Kittiwake Gulls a fourth, whilst the most inaccessible pinnacles seem to be left for the use of the