Induced by these circumstances Rose, in a tabular view of the minerals which he has added to his ' Elements of Crystallography,' published at Berlin in 1833, has united into one genus the following species.
Aka. [Aces.] The true Auks, though they are strictly oceanic birds, scarcely ever leaving the water except for the purposes of reproduction, will some times proceed swiftly though awkwardly on foot when pursued on land. They breed in large companies, in caverns and rocky cliffs, laying only one disproportionately large egg. Their food, which they obtain by diving (an operation in which they are materially assisted by their wings as well as by their feet), consists of small fishes, crustaceans, and other marine animals. The young are said to be fed from time crops of their parents, not only before they are able to leave the place of their birth, but also for some time afterwards.
The genus A/ca, as it is reduced by modern ornithologists, includes but two species. The first of these, the Great Auk (A lea impennis, Linntens), is remarkable for the imperfect development of its wings. It seldom leaves the Arctic Circle and the regions bordering on it ;and and elastic, and the quantities of eggs there collected, amount to almost incredible numbers.
The summer and winter dress of the Razor-Bill, though different, is a rare visitant to the British Isles. Dr. Fleming however gives an account of one taken alive at St. Kilda, where they are sometimes known to breed, which, even with a long and heavy cord tied to its leg, swam under water with extraordinary speed. The power of the apparently useless wings as organs of progression was still more strongly shown in the Great Auk chased ineffectually by Mr. Bullock during his tour to the Northern Isles; for the four oars of the bird are said to have left the six-oared boat of his pursuers far behind. According to the same authority, only a single pair had been known to breed in Papa Westra for several years. Newfoundland is recorded as one of their breeding places, and Pennant relates that the Esqui maux who frequented the island made clothing of their skins. In the ocean that washes the Fame Isles, Iceland, and Greenland, where they dwell in great numbers, they may be frequently seen on the floating ice ; but Pennant says that they are observed never to wander beyond soundings, and that seamen direct their measures according to their appearance.
The food of the Great Auk consists principally of fish ; and the Lump-Fish (Cyclopterus lumpus) is said to be its favourite morsel.
The length of the bird is somewhat under three feet. The winter plumage, which begins to appear in autumn, leaves the cheeks, throat, fore part and sides of the neck white. In spring the summer-change
begins to take place, and confines the white on the head to a large patch, which extends in front and around the eyes; the rest of the head, the neck, and upper plumage is of a deep black. There is a specimen of the bird in its summer dress in the British Museum. The Great Auk breeds in June and July, laying one egg, about the size of a swan's, of a whitish-yellow, marked with numerous lines and spots of black, which have been supposed to bear some resemblance to Chinese characters.
In the Black-Billed Auk, Razor-Bill, or Murre (Aka torda, Linnaeus), the development of the wings is carried to the usual extent necessary for the purposes of flight, though the bird uses them with great effect as oars when swimming under water.
The northern hemisphere, where they are widely diffused, is the region allotted to these birds ; but it is in the higher latitudes that they swarm. In England, the Needles and other adjacent precipitous cliffs have a fair share of them ; and here, as in other places, the ' dreadful trade' of taking their eggs, which are esteemed a delicacy for salads especially, is carried on. In Ray's ed. of Willughby the habits of the Razor-Bill are thus described :—" It lays, sits, and breeds up its young on the ledges of the craggy cliffs and steep rocks by the sea-shores that are broken and divided into many as it were stairs or shelves, together with the Coulter-Nobs and Guillemots. The Mankamen are wont to compare these rocks, with the birds sitting upon them in breeding-time, to an apothecary's shop--the ledges of the rocks resembling the shelves, and the birds the pots. About the Isle of Man are very high cliffs broken in this manner into many ledges one above another from top to bottom. They are wont to let down men by ropes from the tops of the cliffs, to take away the eggs and young ones. They take also the birds themselves when they are sitting upon their eggs, with snares fastened to the ends of long poles, and put about the necks of the birds. They build no nests, but lay their eggs upon the bare rocks." On the coast of Labrador they abound, and the thousands of birds there killed for the sake of the breast-feathers which are very warm do not vary so remarkably as the plumage of many other birds. In the summer dress, the white streak which goes to the bill from the eyes becomes very pure ; and the cheeks, throat, and upper part of the front of the neck are of a deep black, shaded with reddish. In winter the throat and fore part of the neck are white.