The Fulmar Petrel becomes by far the most interesting at its breeding stations. These, however, are isolated and few. In the British area there is only one important nesting place of this species, and that is at St. Kilda—a group of rocky turf-covered islets, that form an ideal haunt for every species of Petrel that frequents the British seas, or even a considerable portion of the North Atlantic. A fortnight’s sojourn on St. Kilda has made me familiar with many of the Fulmar’s habits during the breeding season. It is the bird of all others characteristic of the place; one is reminded of its presence in many ways, but most persistently by the strong smell emitted by this and all birds of the Petrel family, and which scents everything and every person on the islands. The Fulmar is extremely gregarious during the breeding season, and many thousands of birds congregate here during the summer. It is also exceedingly attached to its breeding places, visiting them season by season, for time out of mind, and very probably pairs for life. At St. Kilda, its favourite nesting places are on the downlike cliffs, places where the soil is deep and loamy, and allows the bird to excavate a hollow of varying depth. But there is not sufficient accommodation of this kind for all, and great numbers have to resort to the ledges, crevices, and hollows on the face of the beetling cliffs, or find a site in some cranny amongst the rough piled-up masses of rock. Wherever possible, the Fulmar evidently likes to burrow into the ground, but the hole in most cases is not big enough to conceal the bird. These hollows are lined with a little dry grass, but in many instances a nest of no kind is made. Some of the nests I examined on the bare ledges of the cliffs, were made of small bits of rock. Vast numbers of nests are made close together, and from a distance the sitting birds—all blended together—look like patches of snow. The Fulmar lays but a single egg each season, white in colour, rough and chalky in texture, and with a strong pungent smell, which is retained by the shell for years after the egg has been taken. This egg is laid in May.