Dog (Canis familiaris), a digitigrade, carnivorous animal, forming the type of the genus Canis, which includes also the wolf, the jackal, and the fox. The origin of the dog is a much-debated question. The original stock is unknown, but various species of wolf and jackal have been suggested as ancestors. Probably a number of wild types were domesticated by prehistoric man, and there has been a good deal of crossing
between these different stocks. It is generally agreed that no trace of the dog is to be found in a primitive state, the dhole of India and dingo of Australia being believed to be wild descendants from domesticated ancestors. Several attempts to make a systematic classification of the varieties of dogs have been made, but without much success, it being difficult in many cases to determine what are to be regarded as types, and what as merely mongrels and cross-breeds. Colonel Hamilton Smith divides dogs into six groups as follows: (1) Wolf-dogs, including the Newfoundland, Esquimaux, St. Bernard, shepherd's dog, &c.; (2) Watch-dogs and Cattle-dogs, including the German boar-hound, the Danish dog, the matin dog, &c.; (3) Greyhounds, the lurcher, Irish hound, &c.; (4) Hounds, the bloodhound, staghound, foxhound, setter, pointer, spaniel, cocker, poodle, &c.; (5) Terriers and their allies; (6) Mastiffs, including the different kinds of mastiffs, bull-dog, pug-dog, &c. (See the different articles.) On each side of the upper jaw are three incisors, one canine, four premolars, and three or two molars: on each side of the lower jaw the same number, except that the molars are four or three. The fore-feet have five toes, the hind-feet four or five; the claws are strong, blunt, and formed for digging, and are not retractile. The tail is generally long, and is curled upwards. The female has six to ten mammæ; she goes with young nine weeks as a rule. The young are born blind, their eyes opening in ten to twelve days; their growth ceases at two years of age. The dog commonly lives about ten or twelve years, at the most twenty. By English law it is prohibited to use dogs for purposes of draught.—Bibliography: W. Youatt, Training and Management of the Dog; R. B. Lee, A History and Description of Modern Dogs; F. T. Barton, Our Dogs and All about Them; J. S. Turner and V. Nicolas, The Kennel Encyclopædia.
Dog-days, the name applied by the ancients to a period of about forty days, the hottest season of the year, at the time of the heliacal rising of Sirius, the dog-star. The time of the rising is now, owing to the precession of the equinoxes, different from what it was to the ancients (1st July); and the dog-days are now counted from 3rd July to 11th Aug., that is, twenty days before and twenty days after the heliacal rising.
Doge (dōj: from Lat. dux, a leader, later a duke), formerly the title of the first magistrates in the Italian Republics of Venice and Genoa. The first doge of Venice elected for life was Paolo Anafesto, in 697; and in Genoa, Simone Boccanera, in 1339. In 1437 the Doge of Venice obtained from the emperor a diploma creating him 'Duke of Treviso, Feltre, Belluno, Padua, Brescia, Bergamo, &c.'. In Venice the dignity was always held for life; in Genoa, in later times, only for two years. In both cities the office was abolished by the French in 1797. The title was re-established in 1802 for the Ligurian Republic, but was abolished in 1805.
Dog-fish, a name given to several species of small shark, common around the British Isles. The rough skin of one of the species (Scyllium canicŭla), the lesser spotted dog-fish, is used by joiners and other artificers in polishing various substances, particularly wood. This species is rarely 3 feet long, S. catŭlus, the greater spotted dog-fish, is in length from 3 to 5 feet. It is blackish-brown in colour, marked with numerous small dark spots. Both species are very voracious and destructive. Their flesh is hard, dry, and unpalatable. The common or picked dog-fish (Acanthias vulgāris) is common in British and N. American seas, and is sometimes used as food. It is fierce and voracious. S. profundorum has been brought up from 816 fathoms in the North Atlantic. The tiger or zebra-shark (Stegostoma tigrinum) is a handsome dog-fish native to the Indian Ocean. It is marked with dark stripes on a yellow ground, and may attain the length of 15 feet.
Dogger, a Dutch vessel equipped with two masts and somewhat resembling a ketch. It is used particularly in the North Sea for the cod and herring fisheries.
Dogger Bank, an extensive sand-bank, near the middle of the North Sea, between Denmark on the east and England on the west, celebrated for its cod-fishery. It commences about 36 miles east of Flamborough Head and extends E.N.E. to within 60 miles of Jutland, in some places attaining a breadth of about 60 miles, though it terminates merely in a point. Where
shallowest the water over it is 9 fathoms. In Oct., 1904, the Russian Baltic Squadron fired upon a British fishing-fleet on the Dogger, killing two men. The incident was settled by arbitration. During the European War a naval battle was fought off the Dogger Bank on 24th Jan., 1915, in which three powerful German cruisers were seriously injured by a British fleet under Admiral Beatty, but made their escape to Heligoland.