Mr. Hewitson gives the following account of the breeding of the Petrels in Shetland:--"On the 31st May these birds had not arrived on the breeding-ground; to use the the phrase of the fishermen, 'Had not yet come up from the sea.' Some eggs were deposited as late as the 30th June. In Foula they breed in the holes in the cliff at a great height above the sea; but here (in Oxna) under stones which form the beach, at a depth of three or four feet or more, according to that of the stones, as they go down to the earth beneath them, on which to lay their eggs. In walking over the surface I could hear them very distinctly singing in a sort of a warbling chitter, a good deal like Swallows, when fluttering above our chimneys, but harsher; and in this way, by listening attentively, was guided to their retreat; and, after throwing out stones as large as I could lift on all sides of me, seldom failed in capturing two or three seated on their nests, either under the lowest stone, or between two of them. The nests, though of much the same materials as the ground on which they were placed, seemed to have been made with ease. They were of small bits of stalks of plants and pieces of hard dry earth." Like the rest of the genus, the Storm Petrel lays invariably one egg only. During the daytime they remain within their holes, and though the fishermen are constantly passing over their heads, the beach under which they breed being appropriated for the drying of fish, they are then seldom heard, but towards night become extremely querulous, and when most other birds are gone to rest issue forth in great numbers, spreading themselves far over the surface of the sea. The fishermen then meet them numerously, and, though they have not previously seen one, upon throwing pieces of fish overboard are sure to be surrounded by them; the sharpness of their vision enabling them to see food from afar, which, from the activity of their movements, they are not long in appropriating. [Illustration: THE COMMON STORM PETREL (_Thalassidroma pelagica_). ONE-HALF NATURAL SIZE.] LEACH'S STORM PETREL. LEACH'S STORM PETREL (_Oceanodromus Leachii_) differs from the previous species in having its tail deeply forked; it is, moreover, of much larger size, its length being eight inches, and breadth nineteen inches; the wing measures six inches and three-quarters, and tail three inches and a half. The plumage is of a blackish brown on the head; the rump is white; and the ends of the wing-covers fawn-colour. This species also occupies the Atlantic Ocean, and precisely resembles the Common Petrel in its habits, manners, nidification, and food. * * * * *