In the southern hemisphere the gannet is represented by two nearly allied but somewhat smaller forms—one, Sula capensis, inhabiting the coast of South Africa, and the other, S. serrator, the Australian seas. Both much resemble the northern bird, but the former seems to have a permanently black tail, and the latter a tail the four middle feathers of which are blackish-brown with white shafts.
Apparently inseparable from the gannets generically are the smaller birds well known to sailors as boobies, from the extraordinary stupidity they commonly display. They differ, however, in having no median stripe of bare skin down the front of the throat; they almost invariably breed upon trees and are inhabitants of warmer climates. One of them, S. cyanops, when adult has much of the aspect of a gannet, but S. piscator is readily distinguishable by its red legs, and S. leucogaster by its upper plumage and neck of deep brown. These three are widely distributed within the tropics, and are in some places exceedingly abundant. The fourth, S. variegata, which seems to preserve throughout its life the spotted suit characteristic of the immature S. bassana, has a much more limited range, being as yet only known from the coast of Peru, where it is one of the birds which contribute to the formation of guano.
(A. N.)
[1] The phrase ganotes bæð (gannet’s bath), a periphrasis for the sea, occurs in the Anglo-Saxon Chronicle, in reference to events which took place A.D. 975, as pointed out by Prof. Cunningham, whose learned treatise on this bird (Ibis, 1866, p. 1) nearly exhausts all that can be said of its history and habits. A few pages further on (p. 13) this writer remarks:—“The name gannet is intimately connected with our modern English gander, both words being modifications of the ancient British ‘gan’ or ‘gans,’ which is the same word as the modern German ‘Gans,’ which in its turn corresponds with the old High German ‘Kans,’ the Greek χήν, the Latin anser, and the Sanskrit ‘hansa,’ all of which possess the same signification, viz. a goose. The origin of the names solan or soland, sulan, sula and haf-sula, which are evidently all closely related, is not so obvious. Martin [Voy. St Kilda] informs us that ‘some imagine that the word solan comes from the Irish souler, corrupted and adapted to the Scottish language, qui oculis irretortis e longinquo respiciat praedam.’ The earlier writers in general derive the word from the Latin solea, in consequence of the bird’s supposed habit of hatching its egg with its foot; and in a note intercalated into Ray’s description of the solan goose in the edition of his Itineraries published by the Ray Society, and edited by Dr Lankester, we are told, though no authority for the statement is given, that ‘the gannet, Sula alba, should be written solent goose, i.e. a channel goose.’” Hereon an editorial note remarks that this last statement appears to have been a suggestion of Yarrell’s, and that it seems at least as possible that the “Solent” took its name from the bird.
[2] The large number of gannets, and the vast quantity of fish they take, has been frequently animadverted upon, but the computations on this last point are perhaps fallacious. It seems to be certain that in former days fishes, and herrings in particular, were at least as plentiful as now, if not more so, notwithstanding that gannets were more numerous. Those frequenting the Bass were reckoned by Macgillivray at 20,000 in 1831, while in 1869 they were computed at 12,000, showing a decrease of two-fifths in 38 years. On Ailsa in 1869 there were supposed to be as many as on the Bass, but their number was estimated at 10,000 in 1877 (Report on the Herring Fisheries of Scotland, 1878, pp. xxv. and 171),—being a diminution of one-sixth in eight years, or nearly twice as great as on the Bass.
GANODONTA (so named from the presence of bands of enamel on the teeth), a group of specialized North American Lower and Middle Eocene mammals of uncertain affinity. The group includes Hemiganus, Psittacotherium and Conoryctes from the Puerco, Calamodon and Hemiganus from the Wasatch, and Stylinodon from the Bridger Eocene. With the exception of Conoryctes, in which it is longer, the skull is short and suggests affinity to the sloths, as does what little is known of the limb-bones. The dentition, too, is of a type which might well be considered ancestral to that of the Edentata. For instance, the molars when first developed have tritubercular summits, but these soon become worn away, leaving tall columnar crowns, with a subcircular surface of dentine exposed at the summit of each. Moreover, while the earlier types have a comparatively full series of teeth, all of which are rooted and invested with enamel, in the later forms the incisors are lost, the cheek-teeth never develop roots but grow continuously throughout life. These and other features induced Dr J.L. Wortman to regard the Ganodonta as an ancestral suborder of Edentata; but this view is not accepted by Prof. W.B. Scott. Teeth provisionally assigned to Calamodon have been obtained from the Lower Tertiary deposits of Switzerland.
See J.L. Wortman, “The Ganodonta and their Relationship to the Edentata,” Bull. Amer. Mus. vol. ix. p. 59 (1897); W.B. Scott, “Mammalia of the Santa Cruz Beds, Edentata,” Rep. Princeton Exped. to Patagonia, vol. v. (1903-1904).
(R. L.*)