It is an expert swimmer and diver, and though it flies well and swiftly with rapid beats of its small wings, it rarely avails itself of that means of progression. It feeds entirely on small fish. Early in April it repairs to the cliff where it is to breed, but it is not until May that the large single egg is deposited in some nook or recess of the cliff often quite hidden from view. If, however, suitable recesses are not handy, it will content itself with an open ledge. The egg is white or buffish in ground colour, boldly marked with chocolate brown and black. Incubation, which is carried on by both sexes, lasts about five weeks. The young bird when first hatched is covered with short down and is blackish on the back, white beneath, and yellowish on the head. It remains in the nest for about three weeks, by which time it is covered on the back and breast with downy feathers and has tiny wing feathers caused, as in the case of the game birds, by the rapid growth of the primary wing coverts. At this age the young may be found in the sea, having presumably been carried down by their parents; they can swim readily, but it is said that unless forcibly made to dive by their parents they remain on the surface. In captivity, however, they dive without hesitation on the least sign of alarm, using both wings and feet, and progress with considerable rapidity under water. At the age of about two months the flight feathers proper begin to grow, and then the autumnal moult takes place. In summer the adult has the head, neck, chin, throat, and back deep blackish brown, a narrow line from the eye to the culmen white, and the rest of the under parts white. The bill is black and vertically flattened; it has two or more grooves near the tip that are whitish. It varies greatly in size, and is much larger in some individuals than in others, this difference being probably due to age. The sexes are alike, and in winter the chin and throat are white. Except in the size of the bill, the young bird resembles the adult after the first moult. Length 17 in.; wing 7·3 in. [Illustration: RAZORBILL _Alca torda_ Adult (left). Young (right)] THE GREAT AUK Alca impennis, Linnæus So much has been written on this now extinct species that it need hardly be mentioned here. The last living example was killed off Iceland in 1844, and the last British example was captured in 1834 in Waterford Harbour. In former times it was abundant round Newfoundland, and especially on Funk Island, where the fishermen used to salt it down for food, and soon extirpated it. In appearance it was like a large Razorbill, but it had very small wings and was quite incapable of flight. The lores and under parts were white, upper parts black. Length 32 in.; wing 4·25 in. THE COMMON GUILLEMOT Uria troile (Linnæus)