Their nests are placed so close together, that it is difficult for a man to walk between them. Those first built are of tolerably large dimensions, those made at a later period considerably smaller, while those constructed by the last comers must necessarily be placed on any little unoccupied spaces that can be sought out. The nest itself consists of a mere heap of land or sea plants, on which the female deposits her single egg. The eggs are of moderate size, with chalky-looking shells that are at first white, but soon become of a dirty yellowish brown. The young birds are not hatched till the beginning of June, and by the end of July are about half grown, but still clad in a yellowish white dress of short down. "In the year 1821," says Faber, "I visited one of the little islands upon which these birds had built their nests. As soon as I had landed, both young and old greeted my arrival with a burst of most discordant music, consisting of one harsh shrieking sound. Not one of them, however, stirred from the spot where they sat, so that I might have readily helped myself to as many of them as I chose. The nests lay crowded close together, but the ground was so slippery with all sorts of filth, that in walking amongst them I should have run the risk of falling from the craggy cliffs into the sea. It was a wonderful sight to see the multitudes below fishing for food, which, as soon as they had collected enough, they brought with flagging wings to the top of the rock and laid it before their young ones. Towards the end of August, the nestlings are fully fledged, and at that time if they are not larger they are at least fatter than their parents. In this condition the country people catch as many of them as they can, and salt them for food." In St. Kilda every year there is a regular massacre of young Gannets, which, as they are killed, are thrown down from the rocks into the sea, and there collected into boats; great quantities are then sent to Edinburgh and other places and brought to market. THE COMMON GANNET. The COMMON GANNET (_Sula alba_) is altogether white, except the primary quills, which are brownish black; the upper part of the head and hinder part of the neck are tinged with yellow. The plumage of the young is blackish brown upon the upper parts of the body, speckled with white; the under surface is light brown spotted with a darker shade. The eye is yellow, the beak blueish, the foot green, and the bare skin of the throat black. This species is from thirty to thirty-three inches long, and from seventy-two to seventy-four broad; the wing measures twenty-one, and the tail ten inches. The female is somewhat smaller than her mate.