Page:The American Cyclopædia (1879) Volume VI.djvu/186

 178 DOG canines, strong, curved, and separated by an interval from the incisors; and six molars on each side, the first three, in interrupted series, being small, but with cutting edges, and called also false molars; the fourth or carnivorous tooth is bicuspid, with a small tubercle anteri- orly on the inner side ; the fifth is less cutting, bicuspid, with a large internal tubercle; the sixth and last is small and tubercular. In the lower jaw there are six incisors ; two canines, continuous in the series, and seven molars on each side, of which four are false, the fourth being bicuspid ; the fifth or carnivorous tooth has its tubercular third lobe entirely posterior ; behind this are two tubercular teeth, the last being very small and frequently absent in the adult animal. The incisors are regular, the outer being the largest, and nearly perpendic- ular in the upper jaw ; the lower canines shut in front of the upper ; the tubercular charac- ter of the other teeth indicates a less carnivo- rous propensity than in the cat family, and that their natural diet is not exclusively animal, being better suited for carrion and broken bones than for the flesh of a living prey. In some species, as the buansuah and the dbole, the second tubercular tooth is constantly wanting, according to Hamilton Smith. The brain cav- ity is comparatively small; the crests of the skull and the large temporal fossaa indicate powerful muscles of mastication ; the eyes are directed forward ; the nostrils are largely open- ed in a movable glandular muzzle ; the tongue is soft, thin at the edges, and capable of consid- derable extension beyond the teeth, as is seen during rapid breathing in warm weather ; the pupil is round, as in other diurnal canidw. The fore feet have five toes, the hind feet four or five ; the two middle toes are the longest and equal; the fifth toe, when present, does not reach the ground ; the claws are blunt, strong, not retractile, and formed for digging ; the soles are furnished with tubercles, and in some arctic dogs with hair. The hair is soft and woolly near the skin, longer and coarser ex- ternally ; some of the dogs of India have the skin entirely naked, this condition originating probably from some mangy disease. The tail is generally long, and is curled upward. The number of mammaa varies from six to ten ; the size, form, and color are different accord- ing to the variety. The young open their eyes on the 10th or 12th day ; the first teeth begin to be shed at the fourth month, and the growth ceases at about two years of age ; gestation is about nine weeks, and the duration of life is about 10 years, though sometimes prolonged to 20. Though strong, they are not courageous in proportion to their strength ; hearing is acute, and smell and vision are proverbially delicate, the former in the bloodhound, the latter in the greyhound ; taste is so dull or perverted that even luxuriously fed pets will not disdain a meal of decaying flesh. Dogs are not so cleanly in their habits as cats ; they drink by lapping, require water often, and turn round frequently before lying down; their bark is very different from the howl of wild canines, and expresses by its intonation fear, sorrow, anger, joy, and other feelings. All canines seem to have a natural antipathy to the cat family ; and all, both wild and domesticated, and the nearly allied hyaana, are subject to hy- drophobia. There are several species of wild dogs in different parts of the earth, all of which may have been pressed into the service of man ; the crossings of these with each other, with the wolf in the north, the jackal in the east, the aguara canines in the south, the fennec in Africa, and the fox everywhere, with the care of man to develop special breeds according to his wants, are sufficient to account for all the varieties of our domestic dogs. Dogs dif- fer in stature, in the shape of their ears and tails, and in the number of their caudal verte- brae; some have an additional claw on the hind foot, or an extra false molar tooth on one side ; the hair differs in color, texture, and length ; and all these differences may remain as permanent varieties, like some human races, as long as the circumstances which gave rise to them continue essentially the same. When restored to the wild state, they approximate more or less closely to their original type, whether it be wolf, fox, jackal, or other wild canine. Hamilton Smith classes dogs accord- ing to their apparent affinities with wild ca- nines in corresponding latitudes: the arctic dogs with wolves ; the dogs of the south with the jackal in the old world, and with the aguara canines in South America. The Indian dogs may be traced to the prairie wolf and the Mexican coyote, and in Asia to the jungle koola. "Whatever may have been their origi- nals, it is altogether probable that the primi- tive dogs, like the other domestic animals, were very different from any of the present races, and perhaps from any now existing ca- nines. The first genus of wild dogs is lyciscus (Smith), embracing the prairie wolf and coyote of North America, and the koola of India; the head is broad, the muzzle pointed, ears erect, fur short, tail bushy ; stature about 26 in. ; the disposition is more peaceable than that of the wolf; the voice barking; they are gre- garious and live in burrows. It is probable that the aboriginal Indian dog is derived from the first two; the color is ashy gray, with some white on the tail and breast ; when hunt- ing in packs, these animals are hardly to be distinguished from domestic dogs. They are named L. latrans, L. cagottis, and L. tigris. The red wild dogs, forming the genus chrysem (Smith), are found in the warmer parts of Asia, Africa, and the Australian islands; the muzzle is less pointed than in lyciscus^ and the tail less bushy ; they are shy and fierce, sel- dom burrow, hunt in troops, and bark, and arc about 24 in. high ; they want the second tu- bercular tooth in the lower jaw, and are said to have hairy soles ; they destroy many of tho young of the larger cats; they differ from